Stony Brook Young Investigators Review Spring 2021 Issue 16

LOST, MYSTERIOUS, AND HIDDEN SCIENCE

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More than Sci Fi: Astrobiology’s Search for Alien Life

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Ancestral Immunity: The Role of an Ancestral Gene in the Fight Against COVID-19

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Saving the Artic with Glass

Spring 2021 Volume 16

EDITORIAL Editor-in-Chief: Stephanie Budhan ’21

Managing Editors: Nomrota Majumder ’21 Shrey Thaker ’22

Associate Editors: Nina Gu ’21 Nita Wong ’21 Gabriela Zanko ’23 Riya Gandhi ’22 Nicole Gladstein ’23

LAYOUT Layout Chief: Lauren Yoon ’21

Assistant Layout Chief: Komal Grewal ’23

Layout Editors: Priya Aggarwal ’21 Isra Ahmed ’23 Fanny Zhao ’23 Ujala Dar ’24 Jacqueline Woo ’24

Copy Editors: Rohan Shah ’21 Farah Hasan ’23 Kimberly Lu ’22 Megha Gopal ’24

Peer Reviewers: Gaurav Sharma ’22 Roma Kidambi ’23 Tasfia Haque ’23 Tharun Alamuri ’23 Shreya Addepalli ’24

CABINET

Head of Cabinet: Priya Aggarwal ’21

Webmasters: Matt Ramirez ’22 Ruchira Samant ’23

Event Coordinators: Patricia Praise Cano ’21 Debolina Chanda ’21 Jessica Hui ’21 Hannah Philipose ’23 Aneesha Rompally ’24

WRITERS Highlight Writers:

Yukta Kulkarni ’22 Wendy Wu ’22 Ayesha Azeem ’23 Joyce Chen ’23 Aditi Kaveti ’23

Review Writers:

Thumyat Noe ’23 Panayiota Siskos ’23 Sabah Bari ’24 Sooraj Shah ’24 Vignesh Subramanian ’24

Martha Braun ’21 Travis Cutter ’22 Natalie Dzikowski ’22 Jasmine Kumar ’22 Fiona Murphy ’23 Harshini Suresh ’23 Ean Tam ’23

Chris Cizmeciyan ’24 Devi Chowdhury ’24 Jessica George ’24 Fiona Lam ’24 Shubh Thaker ’24 Juzer Vasi ’24 Jonathan Zhu ’24

SPECIAL THANK YOU TO OUR

FACULTY ADVISORS Dr. John Peter Gergen and Dr. Nicole Leavey

A NOTE FROM OUR

EDITOR-IN-CHIEF Stony Brook Young Investigators Review (SBYIR) is proud to release its 16th biannual publication.

As an undergraduate research journal, SBYIR strives to provide a forum for students interested in scientific writing, to make science accessible to the general public audience, and to highlight the incredible research being done on campus by both faculty and undergraduates.

During our second semester of remote work, SBYIR continued to publish accessible science articles and facilitate science engagement in the Stony Brook community. In an effort to make our organization more accessible to undergraduates, SBYIR opened the organization to new general body members. Several experienced journal staff members stepped up to lead virtual workshops for general members to attend and to learn about the journal publication process.These workshops delved into the nuances of writing a research review article and editing a research highlight as well as into the critical thought and strategy behind the production of high quality graphics for the journal. Our Cabinet also hosted several virtual events to bolster interest in science research despite limited undergraduate research opportunities in this era of remote learning; they hosted a two-part workshop to help students apply for research assistant positions. Additionally, our Cabinet planned fun virtual scavenger hunts and themed jeopardy nights to provide fun opportunities for undergraduates to connect with each other despite limitations brought by the COVID-19 pandemic.

This edition’s journal theme is Lost, Mysterious, and Hidden Science. Many scientists have dedicated their lives to studying the loss of biodiversity, the hidden secrets of mummies and archeology, or even the lost remedies and scientific knowledge of past civilizations. And hidden science is not just historical or buried beneath the surface of the Earth; in present day science can be hidden in plain sight, as evidenced by the discovery of a new human organ or new medicinal herbs within the medical community. We are incredibly grateful to have accepted and published the work of twenty-four undergraduate writers in a slightly longer journal than those published in previous semesters. As you will see, the content of this semester’s publication is incredibly diverse.Our undergraduate writers explored the science behind the elusive Higgs Boson particle, the applications of ancient remedies to antibiotic resistance, the biological defense mechanisms of shapeshifting organisms, and much, much more. The research highlights section also contains a wide range of theme- related articles about forefront research, some of which has been conducted here at Stony Brook. The digital artwork and images wonderfully complement each page of the journal and were skillfully created to communicate complex science concepts in a visually accessible way.

As always I would like to thank our journal staff in the Editorial, Layout, and Cabinet branches as well as our writers for their hard work and commitment this semester and without whom these events or the publication of this journal edition would not have been possible. I would also like to thank our advisors Dr. J. Peter Gergen and Dr. Nicole Leavey, in addition to the Alan Alda Center for Communicating Science for their continued support over the past several years. As I get ready to graduate and step down from my role as Editor-in-Chief, I have no doubt that SBYIR will continue to work together to uphold our reputation as Stony Brook University’s esteemed undergraduate science journal.

STEPHANIE BUDHAN

SPRING 2021

VOLUME 16 4 10 20 40 46

MORE THAN SCI FI: ASTROBIOLOGY’S SEARCH FOR ALIEN LIFE SUPERSYMMETRY OR MULTIVERSE? THE HIGGS BOSON DECIDES. HETEROZYGOUS ADVANTAGES IN THE MODERN WORLD ANCESTRAL IMMUNITY: THE ROLE OF AN ANCESTRAL GENE IN THE FIGHT AGAINST COVID-19 SAVING THE ARTIC WITH GLASS

PALEOLAKES: REMNANTS OF ANCIENT MARTIAN WATERS PANAYIOTA SISKOS ’23 Liquid, running water has played an important role in forming the Martian surfaces and landforms that may be important in understanding the planet’s past. In particular, paleolakes, one such landform, have been found throughout Mars and offer insight into regional geologic history and climate evolution. Paleolake morphology and distribution reflect water distribution and lake deposits compositions, which in turn indicate hydrologic and climate changes of the planet as a whole. This has made paleolakes a popular suggestion for landing sites on exploration missions.

Prior studies have focused on their global identification and distribution, which aided in understanding geologic and climate history of the larger area. This investigation, on the other hand, focused on the area located near the northwest margin of the Hellas basin, considered to be the outer part of Hellas concentric system.

Since Hellas is the largest impact basin in the Martian southlands, the study area is divided into the northwest “highland region” and southeast “slope region” for clarity. Additionally, intra-crater materials are not often studied despite several being present in paleolake basins, causing an incomprehensive understanding of regional geologic and climatic record. As a result, this study included a survey of paleolakes in the northwest Hellas region and an analysis of types and distribution of the aqueous minerals.

Images were made to form detailed analysis of geomorphologic features and hydrologic parameters. The inlet length was also measured for every paleolake and while crater size‐frequency distribution measurements were used to acquire ages of the paleolakes and time of the resurfacing events. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and Thermal Emission Imaging System (THEMIS) spectral data identified aqueous mineral and anhydrous chloride salts.

Through the 64 paleolake basins that were identified, including the 49 basins newly identified and reported by this study, it was found that at 3.6 billion years ago the lakes had been drained. This was followed by volcanic activity at approximately 3.3 billion years ago. After this, at approximately 0.9 billion year ago, glacial activity occurred in the region.

The northwest Hellas region that was analyzed based on the distribution, morphology, and mineral composition of the paleolakes had a climate that changed from warm and wet to semi-arid. Since this study was limited only to the northwest Hellas region, a future path of inquiry includes clarifying the mechanism and characteristics of climate change on regional scales on Mars.

1. S. K. Adamczak, et al., The impact of temperature at depth on estimates of thermal habitat for short-finned pilot whales. Marine Mammal Science, (2020). doi: 10.1111/mms.12737.

2. Image retrieved from: https://unsplash.com/photos/i5FsBOLsB50

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REVERSE THE CLOCK: UNDO EVOLUTIONARY LOSS

PERCEPTION OF EMOTION IN PSYCHOTIC DISORDERS

ADITI KAVETI ’23

WENDY WU ’22

Natural genetic processes can lose their function over long-term evolution if that function requires too many resources to continue throughout generations. Scientists have been studying evolutionary reversibility, which is the ability to regain a lost function, in order to repair natural systems that have lost such valuable evolutionary processes. To this end in the field of synthetic biology, researchers employ and manipulate gene circuits–assemblies of biological parts encoding RNA or protein that enables individual cells to respond and interact with each other–in order to manually encode specific cellular regulatory mechanisms and gene activity.

Gábor Balázsi, Professor of Physical and Quantitative Biology at Stony Brook University, has been studying the reversibility of evolutionary breakdown using yeast cell populations. Balázsi and his team employ a synthetic, positive-feedback gene circuit in which the man-made genetic material has been integrated with the yeast DNA. In the nature of the positive feedback mechanism, the more the products of the gene circuit are used up, the more that circuit functions, thus allowing the yeast to have a better chance of passing on its genetic material to the next generation. In one study, the researchers integrated this circuit into haploid (possessing a single set of chromosomes) Saccharomyces cerevisiae cells to test if the population can restore this “lost” function. The goal of this experiment was to expose mutant populations to conditions where adaptation selection of gene circuit function would be beneficial.

The researchers studied the activity of seven positive-feedback mutant strains in the presence of drugs. Using drug resistance as a marker for positive feedback activation, scientists noticed three adaptation scenarios through genomic mutations that enhanced positive-feedback expression and affected transcription, translation, degradation, and other fundamental cellular processes. In these scenarios, the nonfunctional mutants were able to gain drug resistance, while the quasi-functional and dysfunctional mutants developed a high degree of basal, normal-level expression. The results of this study show how positive-feedback and synthetic biological mechanisms can be successfully employed to revitalize important networks of evolutionary dynamics.

1. K. Gouda, M. Manhart, and G. Balázsi, Evolutionary regain of lost gene circuit function. Proceedings of the National Academy of Sciences of the United States of America 116, 25162–25171 (2019). doi: 10.1073/pnas.1912257116.

2. Image retrieved from: https://pixabay.com/photos/dna-3d-biology-genetic-research-5297378/

Figure 1 Gene circuits can be influenced through genetic engineering to influence a variety of cellular functions.

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Figure 1 The amygdala plays a big role in the experience of emotions, but the effects of its connections to other regions of the brain has so far been understudied.

Schizophrenia, a severe mental disorder that alters perception of reality, is marked by deficits in emotional face perception (EFP). While previous research has shown how abnormal activity in certain brain regions correlates with EFP deficits, the significance of the connections between these regions has been understudied. Amri Sabharwal, a postdoctoral fellow in psychology at Stony Brook University, focused on the amygdala, a region of the brain involved with emotional experiences that has connections to other regions of the face processing network (FPN). Sabharwal aimed to study the functional connectivity of the amygdala to these other regions during EFP in psychotic disorders. They hypothesized that lower amygdala connectivity with regions of FPN would be associated with lower global and social functioning.

Sabharwal gathered 47 participants from the Suffolk County Mental Health Project, 19 with schizophrenia spectrum disorders and 28 with other psychotic disorders. Additionally, 29 never-psychotic (NP) participants were recruited. Each participant underwent an fMRI scan in order to observe functional connectivity of the amygdala with other brain regions. Global functioning and social functioning were assessed using the Social and Occupational Functioning Assessment scale, and the Quality of Life scale, respectively. Participants performed an emotional face perception task showing emotion and neutral conditions. In each condition, participants were presented with a target face and two probe faces. In the emotion condition, participants had to match a probe face to the emotional expression (fear or anger) of the target face. In the neutral condition, participants had to match the identity of the target face.

Across the two conditions, participants with psychotic disorders showed significantly worse EFP accuracy compared to NP participants.

Poor EFP accuracy correlated with worsening global and social functioning.

This correlation was not unique to schizophrenia spectrum disorders, but applied broadly across psychotic disorders. Interestingly, in participants with psychotic disorders, Sabharwal observed greater amygdala connectivity with IFG and insula. This implies there may be an upregulation of emotional processing and greater awareness of physiological arousal in people with psychotic disorders during exposure to unpleasant stimuli, like fear or anger. This upregulation, in turn, disturbs EFP and social functioning.

It should be noted that participants in this study were medicated, and while this factor was statistically controlled for, effects in unmedicated participants remain unclear. Moreover, because only two negative emotions were utilized, Sabharwal’s findings cannot be generalized. Further research should explore a greater range of emotions for EFP. 1. A. Sabharwal, R. Kotov, and A. Mohanty, Amygdala connectivity during emotional face perception in psychotic disorders. Schizophrenia Research (2020). doi: 10.1016/j.schres.2020.11.030.

2. Image retrieved from: https://www.pexels.com/photo/white-and-black-menu-board-5723883/

ECOSYSTEM INTERACTION AND PATHOGEN TRANSFER

PALEOLITHIC BIRD CARVING DISCOVERY IN CHINA

THUMYAT NOE ’21

PANAYIOTA SISKOS ’23

Figure 1 Humans and wildlife have coexisted, but increased human dependence on wildlife has disrupted ecosystems and contributed to a rise in disease outbreaks.

Research suggests that the number of zoonoses, diseases transmitted from humans to animals, have been increasing across the planet. This implies that the frequency of epidemics and pandemics may rise in the future. Zoonotic pathogens have an animal origin and have always existed, but their prevalence and geographic spread are increasing at an alarming rate. Wildlife pathogen epidemics are also on the rise, but in general, the occurrence of wildlife pathogens is normal and plays an important role in nature as a driving force for evolution. However, as a possible result of increased interaction between wildlife and humans, more infectious and deadly pathogens from wildlife have infiltrated human societies. In addition to increased interaction between humans and the wildlife, climate change, biodiversity loss, habitat degradation, and human-driven introductions of pathogens and invasive species through extensive travel and trade have applied tremendous stress on our ecosystems and may have contributed to a rise in disease outbreaks.

As the human population grows, exploitation of ecosystems also increases. This accelerates pathogen transfer between humans. This is problematic because scientists are unaware of how dangerous some of these pathogens can be; therefore, humans are unprepared to face the consequences. COVID-19 is a relevant example of how humans are not yet capable of overcoming an unexpected pandemic. The virus also originated from the wildlife, supporting recent research that zoonoses are now posing increasing risk to societies. This pandemic has already resulted in plummeting economies and serious social distress worldwide, further emphasizing the need for humans to reflect on their interactions with the ecosystem. Habitat destruction, overexploitation and transportation of species, industrial farming, and the increasing volume of travel have all destabilized this environment and ultimately led to this situation. A better understanding of the interconnectedness between humans and nature as well as regulations are necessary to prevent a similar situation in the future.

1. D.S. Schmeller, et al., Biodiversity loss, emerging pathogens and human health risks. Biodiversity and Conservation 29, 3095-3102 (2020). doi: 10.1007/s10531-020-02021-6.

2. Image retrieved from: https://www.pexels.com/photo/photography-of-factory-929385/

Modernity’s understanding about the history of symbolic behavior has increased during the past two decades, and a gradualist scenario has taken shape from the idea of a symbolic explosion occurring 40,000 years ago in Europe with the appearance of anatomically modern human populations.

However, there is evidence that such behaviors are older and emerged from African Middle Stone Age and archaic Europe and Asian populations. A recently-discovered bone carving of a standing bird at the Paleolithic site in Lingjing Henan, China is argued to have a Late Paleolithic origin at 13,500 years, making it the first known instance of original artistic tradition.

Once unearthed, the bird carving was 3D scanned and photographed.

The images were imported to Adobe illustrator to trace areas of manufacture found with a microscope. To account for imaging inaccuracies, the Adobe rendering was compared to the original and corrections were done. This data from different imaging techniques established the technique of manufacture used on the bird and orientation of carving motion on identified areas.

The bird carving displays a morphology related to Passeriformes, the largest order of birds in the world. Unfortunately, there is not enough detail for precise identification. Instead of the short legs associated with the passerine, a bird within the order Passeriformes, there is a large rectangle pedestal for the figurine to stand upright, an oversized tail that prevents tipping, and flat, lateral body parts with no wings. A fragment of mediumsized mammal limb bone with the inner and outer cortex removed was used to create the bird. The carving was blackened, and color gradient and density suggests a controlled heat treatment was used. Despite the first manufacture stage being unidentifiable, it possibly included abrading the bone. Similarly, gouging roughed the figurine and shaped concave areas.

Experimental criteria conclude the traces are consistent with wear patterns from transportation in a leather bag.

The carving of the bird is the first carving discovered at the site and differs regarding technology and style from discoveries in Europe and Siberia. It is the only Paleolithic item carved into burnt bone and with a standing bird on a pedestal and being preserved well enough to observe different manufacturing stages. A future direction for this study may include performing controlled experiments to reproduce the heating treatment used and then analyzing its effect on the ease of carving the raw material.

1. Z. Li, et al., A paleolithic bird figurine from the Lingjing site, Henan, China. PLoS ONE 15, 1-24 (2020). doi: 10.1371/journal.pone.0233370.

2. Image retrieved from: https://pixabay.com/photos/nightingale-bird-nightingale-bird-5203443/

Figure 1 A passerine bird, which is believed to be the subject of the carving discovered at Lingjing Henan, China.

HIGHLIGHTS

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More Than Sci-Fi:

Astrobiology’s Search for Alien Life FIONA MURPHY `23

Figure 1 A representation of planets and stars beyond Earth — the subjects of astrobiology’s search for extraterrestrial life.

Since humanity acquired the knowledge of an expansive universe beyond Earth, many have wondered about the possibility of life existing on other planets. The idea of alien existence captivates humans, excites our creative faculties, and even provokes our deepest fears. Humankind’s widespread fascination with extraterrestrial life is clearly exemplified in popular culture. One only has to look to iconic movies like E.T. the Extra-Terrestrial, beloved literature like The Hitchhiker’s Guide to the Galaxy, or even the growth of conspiracy theories around topics like Area 51 to understand the enamor and curiosity of humans with foreign life.

For many, extraterrestrial life is an interesting possibility to consider, but a seemingly impossible reality to prove. Combining the limitless quality of the universe with humankind’s limited technological capabilities makes

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discovering unfamiliar life forms an extremely difficult task. However, there are scientists across diverse disciplines who study the potential for life outside of Earth and the methods by which this life can be confirmed. Through the possible discovery of extraterrestrial life and the conditions it requires, humanity can hopefully learn more about the origins of our own unique existence in addition to discovering future planets that may be hospitable for human life.

Habitable Zone Because Earth has optimal conditions for supporting life, researchers reduced Earth’s qualities to basic criteria that other planets must meet in order to potentially host alien life. One foundational requirement a planet

must meet is the ability to sustain surface water, particularly in liquid form.

In the presence of water, which is essential for metabolic processes, carbon-based organisms undergoing photosynthesis can survive and multiply enough to be detected. This requirement allowed researchers to establish the habitable zone (HZ), or the area around a Sun-like star where a planet typically must be located to maintain liquid water, and thus life (1).

To provide a clearer definition of the inner limit of the HZ, Dr. James Kasting and his colleagues at Pennsylvania State University classified three main parameters — runaway greenhouse, moist greenhouse limit, and recent Venus limit — based on a planet’s ability to preserve liquid water (1).

The inner limit of the HZ is restricted by a planet’s proximity to its star; if a planet is too close, extreme temperatures will cause the surface water to evaporate. It is highly likely that at temperatures above 647 K, the critical temperature of water (Tw), or the temperature at which there is no difference between liquid and gaseous water, any ocean will completely evaporate. With this knowledge, Kasting and his associates determined that temperatures above Tw indicate a runaway greenhouse climate, where a planet will be unable to host life indefinitely as its surface water will eventually evaporate into space. Additionally, they defined the moist greenhouse limit as a planet whose climate has temperatures below Tw, and yet is still too warm to prevent total evaporation. Kasting and his colleagues made this distinction by reasoning that on planets with atmospheric pressures comparable to Earth’s, these temperatures can cause the saturation mixing ratio of water, or air’s capacity to hold water before condensation, to increase to high levels. As a result, greater amounts of gaseous water are found in the stratosphere, an altitude at which water cannot condense (1). Finally, Kasting and his colleagues identified the recent Venus limit based on evidence suggesting that Venus once contained bodies of water that evaporated due to proximity to the Sun at least 1 billion years ago. With this information, the researchers postulated that an orbital path of 0.75 astronomical units (AU), 4% larger than Venus’s orbital path, is a likely minimum distance that a planet must be from its star to maintain surface water (1).

The Kasting group also defined the outer limit of the HZ based on the assumption that a planet hosting life must also contain large amounts of carbon, mainly in the form of carbon dioxide (CO2). CO2, an important greenhouse gas, helps maintain the temperature of a planet by trapping energy from the neighboring star in the planet’s atmosphere. The maximum greenhouse limit defines the outer limits of the HZ. At this maximum distance away from a planet’s energy source, it is reasoned that atmospheric CO2 allows for the lowest intake of solar energy required to maintain an optimal 273 K temperature of the planet.

Using previously established concepts, Kasting and his group understood that beyond this maximum distance there will be a high albedo due to Rayleigh scattering — the former defined as the amount of light that is reflected by a surface and the latter as the scattering of light by small particles such as CO2. With this principle in mind, the group was able to conclude that more light will be reflected by CO2 than is trapped inside the planet, and thus planets outside of the outer limit will begin to cool to temperatures incapable of supporting life (1).

To obtain a more accurate estimate of the number of life-supporting planets, Dr. Amri Wandel of Hebrew University of Jerusalem implemented the Drake equation and its parameters in his own calculations and statistical analyses. One important factor of the Drake equation remains unknown — Fb, or the probability of life developing on a planet in the HZ. Statistically, this factor can take on any value because Earth is currently the only confirmed planet to host life. However, Wandel suggests that this parameter could fall in the range of 10% to 100%, anticipating that current research endeavors searching for exoplanets containing life markers are successful (2). Coupled with the assumption that life can develop on planets orbiting red dwarf stars (smaller and more abundant than Sun-like stars), Wandel proposes that there may be between 109 and 1010 feasible life-supporting planets in the galaxy, indicating that the nearest one could be around 10 light-years away (2).

To determine how many alien civilizations may exist, the Drake equation requires two more factors: the probability that life develops into a complex civilization capable of communication through radio signaling and the longevity of a civilization with such capabilities. The communicative property of radio signaling is necessary for determining the likelihood of detecting such a distant civilization. Based on the extremely low probabilities of these additional Drake equation parameters, Wandel posits that the nearest complex alien civilizations may be several thousand light-years away (2).

Exoplanet Discovery To confirm theories of alien existence, researchers are currently seeking to discover life-supporting exoplanets in the HZ. NASA’s Kepler Mission, which ran from 2009 to 2013, made great advancements in the area of exoplanet discovery within the Milky Way galaxy. The Kepler spacecraft detected exoplanets within the HZ of their neighboring star via the “transit method,” monitoring for a decrease in the light intensity of a star, indicating that a planet is passing in front of it. By assessing the size of the planet’s orbital path, the size of the planet, and its temperature, NASA researchers determined whether the planet fell in the HZ and could host life (3). Over the course of the Kepler mission, 2,394 exoplanets were discovered and 391 of which were deemed either candidate or verified exoplanets in the HZ of their star (4).

Nearest Neighbors Scientists determine the possible existence of nearby life-sustaining planets using the Drake equation — Nc = R*FsFpFen- Figure 2 NASA’s Kepler telescope, which made breakthrough advancements in exoplanet discovery during its four-year run, identifying 2,394 exoplanets.

F F L . The Drake equation considers various factors like the rate hz b c c of star formation in the Milky Way, the proportion of stars with planets, and the number of planets with environments capable of supportToday, mechanisms such as TESS, or the Transiting Exoplanet Suring life, among others, to loosely estimate the number of alien civilizations vey Satellite, continue the work begun by the Kepler mission. Initiated in existing in our galaxy. Modified versions of the equation approximate the 2018, TESS takes a similar approach to the Kepler spacecraft; it searches number of planets that host any form of life (2). for a plunge in a star’s brightness to reveal an orbiting planet. TESS also

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has technological features that make it more sensitive to red wavelengths, granting the satellite an improved ability to observe red dwarf stars and any orbiting exoplanets. The satellite is anticipated to identify upwards of one thousand exoplanets, some projected to be Earth-sized (5).

Conclusion Many researchers suggest that there is a very real possibility that extraterrestrial life does exist, although it has yet to be detected. Each day, small advancements are being made in the realm of astrobiology that bring humanity closer to confirming whether there is truly life beyond planet Earth. If we are able to conclude that alien life exists, there is potential to learn more about how the universe developed, and whether humans may be able to thrive on other planets in the future. However, what we do know for sure is that the mystery of extraterrestrial existence is one that is not likely to be resolved any time soon.

References 1. J. Kasting, et. al., Remote life-detection criteria, habitable zone boundaries, and the frequency of Earth-like planets around M and late K stars. Proceedings of the National Academy of Sciences of the United States of America 111, 12641-12646 (2014). doi: 10.1073/pnas.1309107110.

2. A. Wandel, How far are extraterrestrial life and intelligence after Kepler?. Acta Astronautica 137, 498-503 (2017). doi: 10.1016/j.actaastro.2016.12.008.

3. B. Dunbar, Mission overview. NASA, (2018).

4. A. Laity, et. al., Exoplanet and candidate statistics. NASA Exoplanet Archive, (2020).

5. A. Krishnamurthy, et. al., Precision characterization of the TESS CCD detectors: Quantum efficiency, charge blooming and undershoot effects. Acta Astronautica 160, 46-55 (2019). doi: 10.1016/j.actaastro.2019.04.016 6. A. Nascetti, et. al., Integrated chemiluminescence-based lab-on-chip for detection of life markers in extraterrestrial environments. Biosensors and Bioelectronics 123, 195-203 (2019). doi: 10.1016/j.bios.2018.08.056 7. V. Parro, et. al., SOLID3: A multiplex antibody microarray-based optical sensor instrument for in situ life detection in planetary exploration. Astrobiology 11, 15-28 (2011). doi: 10.1089/ ast.2010.0501

Figure 3 TESS, the Transiting Exoplanet Survey Satellite, orbiting in space, as it searches for exoplanets as they pass in front of distant stars.

Biomarker Detection To further confirm the existence of extraterrestrial life, biomarkers, or the organic molecules found in and produced by living organisms, may be used. In the past, researchers identified biomarkers via pyrolysis-GC-MS, wherein molecules are heated at extreme temperatures and then detected through gas chromatography and mass spectrometry. However, scientists could only detect very small organic molecules that are also produced via abiotic processes, rendering any results as inconclusive. Additionally, the interactions that occurred during pyrolysis-GC-MS were highly volatile, causing the molecules to decompose, making detection difficult (6).

In recent years, Spanish Astrobiology Center researcher Victor Parro and his colleagues devised new approaches to biomarker detection, such as the Signs of Life Detector (SOLID) chip, which utilizes immunoassay technology. Immunoassays use sensitive antibodies to identify molecules in low concentrations (7). In general, small lab-on-chips like SOLID are more effective as they do not cause volatile interactions, and can detect both small and large organic molecules, including cells. One molecule of interest for discovery is ATP, or adenosine triphosphate, which quickly deteriorates outside of a living organism and is thus a good indicator of the presence of life (6).

When designing technologies to be used in space exploration, scientists must consider that resources are limited on a spacecraft. Instruments used to conduct biomarker detection must be small and energetically efficient. An issue with current chips is that their use of fluorescence detection methods requires external equipment to be operated, which takes up space and power. To solve these issues, Dr. Augusto Nascetti and his fellow researchers at Sapienza University of Rome have recently designed the Planetary Life Explorer with Integrated Analytical Detection and Embedded Sensors (PLEIADES). This chip utilizes chemiluminescence detection instead of fluorescence, such that detection is completed via small-scale chemical reactions as opposed to the use of an external photoexcitation mechanism.

Thus, PLEIADES does not require supplementary machines and actually eliminates some of the side effects of fluorescence methods that impact the data (6).

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Images retrieved from: 1. https://cdn.pixabay.com/photo/2020/09/12/00/03/planets-5564482_1280.jpg 2. https://upload.wikimedia.org/wikipedia/commons/thumb/1/16/Kepler_Telescope_in_sapce. jpg/1600px-Kepler_Telescope_in_sapce.jpg 3. https://upload.wikimedia.org/wikipedia/commons/0/0d/Tess_Satellite.jpg 4. https://live.staticflickr.com/1880/44799056732_f4735d89c7_b.jpg

Figure 4 The first image captured by TESS, featuring many stars as well as solar systems that are known to host exoplanets.

Antibiotic Resistance: a modern problem with ancient solutions

JESSICA GEORGE `24 Figure 1 Bacterial biofilms serve as major protective mechanisms against antibiotics.

Antibiotic resistance: A modern problem with ancient solutions Since the early 1940s, antibiotics have diminished mortality associated with bacterial infections, contributing to a 29.9 year increase in life expectancy, earning the reputation of being one of the most revolutionary achievements in the history of medicine (1). However, inappropriate and excessive use of antibiotics has given rise to a new deadly era of antibiotic-resistant bacteria. In the U.S. alone, antibiotic resistance is responsible for over 2.8 million infections and 35,000 deaths annually (2). Current solutions are unsustainable as they are limited to modifying previously used antibiotics. In recent years, botanical species, such as blackberry root and Brazillian peppertree berry, and clay minerals have caught the attention of researchers as potential options in understanding and eradicating antibiotic-resistant bacteria. Years of experimentation with natural remedies provides researchers with a foundational understanding of where to focus their studies. Additionally, natural substances are less toxic and offer decreased chances of engendering resistance in bacteria due to increased amounts of active principles involved (3). Though the issue of antibiotic resistance is ceaseless, natural remedies could be a significant component of the multi-faceted approach to provisionally preventing antibiotic resistance in bacteria.

Antibiotics are designed to be lethal to their bacterial target.

However, some microbes naturally accumulate random mutations, becoming resistant to the antibiotic’s effects by means of natural selection. The surviving bacteria then proliferate and pass on their antibiotic-resistant genes to the next generation, in time producing a generation of antibiotic-resistant bacteria. Additionally, antibiotics may also kill bacteria that are vital in protecting the body from infection, further exacerbating the effects of antibiotic-resistant bacteria. Bacteria are also equipped with defense strategies that help them actively defend against antibiotics. These mechanisms include utilizing bacterial plasmids that house the necessary genet-

ic information for the bacteria to develop resistance. A unique property of plasmids includes the ability to share this valuable DNA from one microbe to another, leading to a chain of resistant strains of bacteria (4).

Botanical cures to MRSA: Researchers have been exploring botanical species as a potential solution to methicillin resistance, the leading cause of hospital and community associated infections around the world, and the blackberry plant appears to be a promising candidate. Ethnobotanist researcher Cassandra Quave discovered the use of blackberry pomace extract (BPE) in ancient treatments of abscesses during her visit to southern Italy. When sent to her lab in Atlanta, researchers discovered that when molecules of phenolic acids of BPE were tested in vitro with cultured MRSA (methicillin-resistant Staphylococcus aureus), the acids inhibited the formation of biofilms, an adhesive entanglement of bacteria that easily coheres to tissue and inhibits the ability of medicine to penetrate the target bacteria (5). Phenolic acids of BPE act to disrupt the membrane and slime layer of biofilms, while their delocalized electron system destabilizes the cytoplasmic membrane, leading to the collapse of proton motive force. Through confocal imaging, Qauves’ group demonstrated that 220D-F2 (a BPE extract from the root that contains high levels of gallic acid) inhibited the formation of biofilms when incubated with methicillin resistant strains of bacteria. Wild-type strains that were not treated with 220D-F2 formed biofilms that were 88–92 µm thick while the strains exposed to 220D-F2 developed patchy biofilms with only a small number of isolated clumps of adherent cells (6). Additionally, when 220D-F2 was combined with antibiotics clindamycin and oxacillin and used to treat methicillin-resistant strains, the anti-biofilm effects were enhanced.

After seven days, a 2.5 log decrease in biofilm colony count in comparison to the antibiotic alone was observed (6). The significant decrease in biofilm formation exhibits the effectiveness of 220D-F2 in impeding a biological

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mechanism of antibiotic resistant bacteria. Additionally, separate tests comparing the colony count of the methicillin-resistant bacteria biofilm in catheters with the antibiotics (daptomycin, clindamycin, and oxacillin) and catheters with both antibiotic and 200 µg/mL of 220D-F2 were conducted. The catheters that were exposed to only the antibiotics yielded a colony count of 1.01x107 while the catheters exposed to a combination of antibiotic and 220D-F2 yielded a significantly smaller colony count of 3.3x103 (6).

The data observed suggests that antibiotics do not need to be abandoned but rather natural remedies can be used along with pre-existing antibiotics to create an enhanced effect. Quave’s discovery was especially momentous as the phenolic acid molecules did not prove fatal to the MRSA microbes like most antibiotics do. Instead, the plant molecules were able to hinder the bacteria’s defense mechanism, possibly impeding the development of resistance.

Researchers at the University of Maryland also explored the abilities of the blackberry plant with regards to gene expression. Methicillin efficiency is restored by suppressing expression of genes involved in antibiotic resistance, such as gene mecA, and others like norA associated with efflux pumps that expel antibiotics from within the cell (5). Researchers prepared BPE by combining blackberry and blueberry (1:1 ratio) and placed it with MRSA strains. Through utilization of quantitative RT-PCR assay, researchers examined the differential expression levels of genes in the methicillin bacteria, discovering that BPE significantly (p < 0.05) down-regulated the aforementioned gene products by inactivating antibiotic binding proteins that are utilized by efflux pumps to identify which substance to expel (5).

By obstructing the defense mechanisms of bacteria without killing them, BPE is able to effectively inhibit the negative effects of the microbes without engendering resistance through evolution. Additionally, the phenolic acids of BPE were found to inhibit the growth of MRSA. Testing via antibiogram with broth microdilution exhibited that BPE and gallic acid decreased the minimum inhibitory concentration (MIC) of MRSA from 512 μg/mL to 4 μg/mL (5). By reducing the lowest concentration at which a substance is able to hinder the growth of bacteria, gallic acid of BPE successfully increases the effort it takes for MRSA to proliferate.

Quave’s team observed that another plant, Schinus terebinthifolia (Brazillian peppertree), also displayed virulence inhibiting properties.

430D-f5 (a flavone-rich extract of brazillian peppertree berry) extracts from the leaf of this species were used to treat cutaneous skin lesions in rats and extract from the bark was used to treat beef cattle for 17 days, causing improved wound healing, improved clotting, and formation of a fibrin net, a fibrous protein mesh that aids in clotting, at the site of the wound for both animals (7). In the mice, the size of the lesion remained under 0.1cm2 throughout the 14 days after a single 50μm dose of 430D-F5 . The control group on the other hand, showed a significant spike up to a lesion size of 1.0cm2 and then a decrease to 0.25cm2 by day 14 (7). Prevention of lesions is a significant property as open wounds allow for more bacteria and other microbes to infect the individual. 430D-f5 inhibited the expression of accessory gene regulators, which control many of the virulent mechanisms of bacteria including initial infection of cells, evasion of an immune system response, quorum signalling, and the destruction of tissues (7). 430D-f5 was able to shrink bacterial MRSA biofilms and prevent the formation of skin lesions. The incredible facility of these botanical species to disrupt bacterial function without off-target physiological toxicities builds the foundation for future combat with resistant bacterial infections.

Application of clay minerals in the treatment of bacterial ulcers: Kisameet clay (KC), a type of natural glacial clay, has its origins in northern British Columbia and has been documented to have a history of therapeutic applications, particularly in remedying skin infections due to its anti-inflammatory and antiseptic properties. Recent research with kis-

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ameet clay conducted by Shekooh Behroozian and his team at the University of British Columbia has shown that, in vitro, it demonstrates antibacterial properties against ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter) pathogens (8). ESKAPE pathogens are the leading cause of nosocomial infections, or those originating in a hospital, and earn their name as a result of their ability to “escape” the mechanisms of antibiotics. Behroozian and his team tested the KC leachate (water percolated through KC) with P. aeruginosa and S. aureus in biofilm microplate assays to determine the antimicrobial effects of the minerals in the clay.

Quantification of P. aeruginosa biofilms displayed that the clay leachate reduced biofilm formation to approximately 30% of the initial material in 10 hours (8). In S. aureus, the clay leachate also inhibited biofilm formation to 30% of the initial material in approximately 24 hours, reaching 25% of the initial material by 48 hours (8). The ability of KC to significantly reduce one of the bacteria’s most useful defense mechanisms is of high importance as it is essential that new solutions be found where the microbes are not completely killed. Furthermore, KC’s capacity to obstruct the formation of biofilm in an accelerated manner is of great value as bacteria rapidly proliferate and a fast-working solution is necessary to combat this.

KC has demonstrated success in eradicating ulcer-causing bacteria due to its ability to partially or completely inhibit the growth of the microbes. To gain understanding into this process, researchers Shelley E. Haydel, Christine M. Remenih, and Lynda B. Williams at Arizona State University investigated the mineral components of the clay. One clay mineral, CsAg02, displayed bactericidal properties against a variety of bacteria. To assess the effects of this mineral, researchers placed CsAg02 with bacterial cultures of E. coli, ESBL E. coli, S. enterica serovar Typhimurium, and P. aeruginosa. The results of the susceptibility testing demonstrated that the clay mineral completely killed the antibiotic-sensitive bacteria (9). Further

Figure 2 Botanical species such as Rubus ulmifolius (blackberry) have been discovered to posse erties.

testing with M. smegmatis and M. marinum resulted in the complete inhibition of growth for M. marinum and a 1,000-fold reduction in growth of M. smegmatis in comparison to the bacterial cultures grown without CsAg02 (9). In regards to the mineral’s mechanisms of action, researchers hypothesize that CsAg02 eradicates bacteria indirectly by engendering an unfavorable environment for the antibiotic resistant bacteria. Researchers found that the iron ions (Fe2+) in clay minerals saturate the membranes of bacteria, causing the oxidation of the inner cell (10). This oxidation process causes the production of hydroxyl radicals which are deadly to the microbes. Additionally, the minerals in clay get their bactericidal properties from their ability to either deprive bacteria of their essential nutrients (like iron) and disrupt the homeostatic balance bacteria require for metabolic processes. CsAg02 was found to buffer both pH and oxidation state, creating conditions that were not ideal for the microbe to cause harm. The data exhibits CsAg02’s broad-spectrum antibacterial properties which is useful in expanding the application of this mineral to various other bacterial infections. Eradication of the resistant bacteria by targeting internal environment stability through the use of CsAg02 presents a successful alternative to the use of antibiotics, which have more toxic components than the natural clay.

Conclusion Presently, treatments with natural remedies are not widely implemented with patients in clinical settings. Traditional remedies using natural substances are often overlooked as pseudoscientific homeopathy. However, dismissing all natural materials as a potential solution to modern issues eliminates the possibility of implementing an innocuous and sustainable treatment to bacterial conditions. As modern research suggests, natural medicine offers many promising candidates worthy of clinical investigation.

A paradigm shift in how medicine is developed and operates is imperative in advancing modern medicine. As evident from the extensive deaths due to antibiotic-resistance, current solutions to bacterial infections have proved unsustainable, calling for novel approaches where bacteria are understood instead of completely eliminated. The studies into blackberry root, Brazillian peppertree berry, and clay minerals present several forerunners as potential solutions to the antibiotic resistance crisis but further study into the remedies of the natural world is essential. Delving deeper into ancient remedies may give rise to a new age of medicine that could work towards resolving some of the most pressing threats to public health.

References 1. Achievements in public health, 1900-1999: Control of Infectious Diseases. CDC, (1999).

2. Antibiotic resistance threats in the United States 2019. CDC, (2019).

3. P.D. Gupta and J. B. Tannaz, Development of 3 botanicals to combat antibiotic resistance. Journal of Ayurveda and Integrative Medicine 8, 266-275 (2017). doi: 10.1016/j.jaim.2017.05.004.

4. How antibiotic resistance happens. CDC, (2020).

5. S. Salaheen, et al., Eradication and sensitization of methicillin resistant Staphylococcus aureus to methicillin with bioactive extracts of berry pomace. Frontiers in Microbiology 8, (2017).

6. C.L. Quave, et al., Ellagic acid derivatives from Rubus ulmifolius inhibit Staphylococcus aureus biofilm formation and improve response to antibiotics. Plos One, (2012).

7. A. Muhs, et al., Virulence inhibitors from Brazillian peppertree block quorum sensing and abate dermonecrosis in skin infection models. Sci Rep, (2017).

8. S. Behroozian, et al., Broad-spectrum antimicrobial and antibiofilm activity of a natural clay mineral from British Columbia, Canada. mBio, (2020).

9. S. Haydel, C. Remenih, and L. Williams, Broad-spectrum in vitro antibacterial activities of clay minerals against antibiotic-susceptible and antibiotic-resistant bacterial pathogens. J Antimicrob Chemother, (2008).

10. L. Williams, et al., What makes a natural clay antibacterial? Environ Sci Technol, (2011).

Images retrieved from: 1. https://upload.wikimedia.org/wikipedia/commons/2/28/Mixed-culture_biofilm.jpg 2. https://upload.wikimedia.org/wikipedia/commons/c/c5/Illustration_from_Medical_Botany%2C_digitally_enhanced_from_rawpixel%27s_own_original_plates_88.jpg

ess antibacterial prop-

The incredible facility

of these botanical species to disrupt bacterial function without off-target physiological toxicities builds the foundation for future combat with resistant bacterial infections...

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Supersymmetry Or Multiverse?

The Higgs Boson Decides.

JUZER VASI `24

Introduction July 4th, 2012. For most Americans, this Independence Day was filled with its usual festivities: get-togethers, outdoor barbeques, and fireworks lighting up the endless night sky. Across the Atlantic Ocean, particle physicists in Geneva were also celebrating something remarkable: the detection of a particularly elusive fundamental particle integral to the structure of the universe, the Higgs Boson.

The presence of the particle was confirmed by physicists operating the Large Hadron Collider (LHC)—the world’s largest and fastest particle accelerator—at CERN, the European Organization for Nuclear Research. The confirmation of the particle’s existence represented an inflection point in the understanding of the universe, and garnered much attention within the circles of theoretical and particle physicists. After analysis, the Higgs would either suggest that the fundamental nature of the universe relies on an ordered model of elementary particles, such as supersymmetry, or undermine basic understandings of the universe by suggesting a “many worlds” universe known colloquially as the multiverse theory. The very structure of reality was to be determined by one specific property of the infinitesimally small particle: its mass. As CERN set out to calculate the mass of the detected Figure 1 The particles composing the particle, physicists around the globe held their breath.

Standard Model of particle physics.

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The Standard Model of Particle Physics Before discussing CERN’s findings, it is integral to first understand the Higgs Boson itself as well as the competing fundamental theories of supersymmetry and the multiverse.

As the Higgs Boson exists in a quantum state, it is crucial to discuss the fundamentals at the basis of particle physics. Atoms are not the true building blocks of the universe. To physicists, protons and neutrons represent another layer of matter composed of incredibly small elementary particles influenced by fundamental forces. As the field of quantum mechanics has developed over time, more of these particles and forces have been detected and compiled into the Standard Model of Particle Physics based on their properties. While the Standard Model (SM) bears much credence, it is still a changing mathematical theory; it is not perfect, and requires the support of supplementary theories to fully explain other phenomena in the universe.

Tara Shears, particle physicist at the University of Liverpool, cogently describes the two core groups of the SM in her research: elementary particles known as fermions, and fundamental forces known as bosons. In total there are 12 fermions—six quarks and six leptons—that comprise the true fundamental building blocks of all known matter in the universe. Aside from electrons—a type of lepton—quarks are the most well known of the elementary particles as they combine

to form protons and neutrons. Physicists have discovered and identified six different quarks grouped in pairs forming three generations increasing in mass. The first generation pair of quarks are the up and down quarks (these combine together to form protons and neutrons), followed by the charm and strange, and top and bottom quarks. The other group of fermions known as leptons include six particles: the electron, muon, and tau joined alongside their corresponding particle-pairs known as neutrinos (1).

While the 12 fermionic particles are the “building blocks” of matter, Shears indicates the universe would be unable to function without forces acting upon this matter. As fermions compose all known matter, force carrying particles known as bosons interact with fermions to create a dynamic universe. The SM is composed of five bosons: four gauge (vector) bosons and one scalar boson. The four gauge bosons mediate three fundamental forces of nature: strong force, weak force, and electromagnetism.1 Gluons govern strong force akin to forces found within atomic nuclei. The W and Z bosons are responsible for weak interaction, whilst photons mediate electromagnetic interactions. The final boson? The Higgs.

The Higgs Boson By the 1960s, it became clear to physicists that the functions of two of the major fundamental forces—electromagnetism and weak force—were incredibly similar. Thus, physicists sought to combine these forces into a unified theory describing an “electroweak” force which governs electricity, magnetism, light, and some radioactivity—solidifying the SM in the process. However, there was a catch: while correctly describing the predicted features of an electroweak force, it appeared that mathematical calculations revealed that the individual bosons emerged massless. While this made sense for a photon, it had already been determined that W and Z bosons have large masses nearly a 100 times larger than that of a proton (2).

In 1964, efforts by Peter Higgs, Francoise Englert, and Robert Brout led to the proposal of the Brout-Englert-Higgs (BEH) mechanism. Simply

Figure 2 Decorated theoretical physicist and 2013 Nobel Laureate Peter Higgs who proposed the mechanism (alongside François Englert and Robert Brout) predicting the existence of the Higgs Boson in 1964.

1 Although gravity is considered a fourth fundamental force, it is not included in the Standard Model as it is incompatible with general relativity. The inability to incorporate general relativity into quantum mechanics remains one of the biggest conundrums to physicists to date, thus preventing them from reaching the “Theory of Everything.”

put, the mechanism assigned mass to elementary particles through their interaction with an energy field known as the Higgs field. The mechanism also allowed for elementary particles to retain the structure of their original interactions, work at high levels of energy, and allowed for photons to remain massless. Finally, the mechanism implicated that the field would materialize itself into a particle with a certain mass: the Higgs Boson (3).

Ultimately, the Higgs Boson explains the mass of most elementary particles in the SM, essentially serving as its foundation. Without the Higgs mechanism, the SM would collapse onto itself. Thus began a near 50 year hunt for the particle that would solidify the calculability of the SM, and provide consistency to the years of experimental data collected (4). It was not until the advancement in technologies illustrated in the LHC that physicists were able to complete half a decade’s work and report the existence of the Higgs (5).

Ultimately, the Higgs Boson explains the mass of most elementary particles in the SM, essentially serving as its foundation.

Supersymmetry (SUSY) With a necessary understanding of the vitality of the Higgs Boson to the SM, it is possible to understand the first of the two competing theories of the universe being discussed. By the time physicists were on the verge of detecting the Higgs for the first time, decades of experimental data had boosted the SM to a respectable level of credibility. However, as orderly and fitting as the SM is, it simply does not answer all the questions of the cosmos. That is where supersymmetry (SUSY) comes in.

Similar to string theory, SUSY resembles a theoretical extension to the base principles of the SM in an attempt to explain certain phenomena that it cannot. Furthermore, SUSY is not a theory, but rather a principle that is extended to the SM. As such, a crucial and universal aspect of SUSY is that it treats matter and force identically. As a distinguished professor of particle physics at UC Santa Cruz, Howard Haber, succinctly summarizes in terms of the SM, for all matter elementary particles (quarks and leptons), there are “cousin” force particles called squarks, sleptons, and sneutrinos. Similarly, for the force carrying bosons of the SM, their matter SUSY cousins are as follows: Gluinos, Photinos, Zinos, Winos, and finally Higgsinos (6).

Despite a lack of any “hard” evidence thus far, SUSY has the potential to explain numerous unsolved mysteries at both the quantum and cosmic levels. Haber mentions dark matter, which has been one of the most perplexing issues for theoretical physicists for decades. Dark matter composes approximately one quarter of the energy density of the universe as well as an incredible proportion of known matter of the universe—a staggering 25 percent. Yet even modern physicists are certain of only a few of its properties: it exists in large amounts, interacts with gravity, and does not absorb or

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Despite a lack of any “hard” evidence thus far, SUSY has the potential to explain numerous unsolved mysteries at both the quantum and cosmic levels. emit light. However, preconceptions about this hidden matter changed with the development of SUSY. The appeal of SUSY to physicists is its introduction of the slew of new hypothetical cousin particles; one of these particles, dubbed the lightest supersymmetric particle (LSP), resembles exactly what physicists have observed in what a dark matter particle would be—a weakly interacting massive particle (WIMP). While an exact supersymmetric particle has not been identified as the likely dark matter particle, future particle accelerator runs may finally provide experimental data. Until then, SUSY offers the strongest explanation for dark matter (7).

Aside from providing answers to pressing issues facing physicists by extending the SM, SUSY also rectifies shortcomings of the SM itself—specifically the mass of the Higgs. According to Baer et al., the mass of the Higgs Boson in conjunction with the SM and LHC, is large. If SUSY is real, the theoretical cousin particles would cancel out the inflated mass of the Higgs from SM, offering a mass confluent with what physicists have observed over the decades (8).

SUSY provides an organized and structured explanation of the universe and appeals greatly to physicists disillu-

sioned with more obscure theories such as multiverses. Nonetheless, as promising as SUSY sounds, there has been little experimental data to suggest its viability. With future runs of particle accelerators at CERN planned for the future, SUSY may be given more credibility. For now, all theories of the universe—including the multiverse—are fair game.

Multiverse Unlike SUSY, the multiverse theory is less rooted in structure, technicality, and arithmetic. Rather, it is based upon a fundamental sociological assertion of cosmologists: the laws of physics observed in this reality are not fundamental, but simply a reflection of a single possibility that the physical reality may have constructed. According to particle physicist David Kaplan, proponents of the multiverse believe that all measured physical data in the universe were “generated randomly” out of a vast array of possibilities. The laws of physics observed in this universe create structures capable of constructing what is perceived as reality (e.g., the sun, earth, life, and humans). By virtue of the fact that humans exist within this universe, there is bias towards what we perceive as the fundamental laws of physics that govern the universe (9).

While the multiverse theory is more or less entrenched in theoretical philosophy, there are some quantitative details to help explain why this theory has become prevalent in recent times. As Larsen, Nomura, and Roberts indicate, in the 1980s, astronomers discovered cosmic inflation: the expansion of the universe. Before this discovery however, there existed a cosmological constant, Λ, a single number that described the universe. After the discovery of cosmic inflation, the rate of expansion was measured to be trillions of times faster than what would have been previously expected. This caused a major problem for theoretical physicists: the cosmological constant, a value that described the specific parameters of the universe, was com-

Figure 3 An artistic approximation of what the Higgs boson particle may look like.

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pletely off (10).

This apparent discrepancy caused physicists to begin to question the very structure of the universe. It is vital to note that multiverse does not suggest the existence of different “bubbled” universes with corresponding doppelgangers; it questions whether physicists know anything about the universe at all. Regardless, as much as the multiverse theory asserts a lack of structure, there is one essential prediction of the theory that makes internal theoretical sense: the existence of the Higgs at a certain mass.

Ultimately, SUSY and multiverse are opposite predictions of the mysterious inner workings of the universe. Earlier it was stated that the credibility of each theory would depend on the specific value of the detected boson mass. SUSY predicted a Higgs Boson with a mass exactly 115 GeV; the multiverse theory projected a heavier mass of 140 GeV. The result? 125 GeV. Conclusion Weeks of data analysis following the run of the LHC revealed a mass almost exactly in the middle between the two predictions. Ultimately, the 2012 Independence Day Higgs did not decide between SUSY and multiverse. Regardless, the discovery of the Higgs itself was a massive accomplishment, as each theory as well as the SM itself depended on its existence.

However, the implications of the mass of the Higgs remain a mystery. The LHC has been shut down since 2018, and engineers have focused on upgrading the collider with the hopes of new particle discoveries. The LHC is expected to run again this spring.

There is ultimately only one predictable characteristic of the universe: unpredictability. While physicists at CERN in 2012 did not achieve

all the answers necessary to fully understand the universe, they completed a fifty-year hunt for the most elusive, mysterious, and consequential particle in the universe.

While the Higgs Boson did not end up deciding the fate of the universe in 2012, it still remains the quantum mechanical keystone that will likely play a significant role in future discoveries

Figure 4 A segment of the LHC tunnel in which particles would travel at high speeds prior to collision.

References 1. T. Shears, The standard model. Philosophical Transactions of the Royal Society A 370, 1-13 (2012).

2. The Brout-Englert-Higgs mechanism. CERN, (2021).

3. H. Gray and B. Mansoulié, The higgs boson: the hunt, the discovery, the study and some future perspectives. Atlas Experiment, (2018).

4. J. Ellis, M. Gaillard, and D. Nanopoulos, A historical profile of the higgs boson. World Scientific, 255-274 (2016). doi: 10.1142/9789814733519_0014.

5. S. Wu, Brief history for the search and discovery of the higgs particle — a personal perspective.

International Journal of Modern Physics A 29, 1-34 (2014). doi: 10.1142/S0217751X14300622.

6. H. Haber, Supersymmetry, part i (theory). Particle Data Group, (2013).

7. G. Jungman, M. Kamionkowski, and K. Griest, Supersymmetric dark matter. Semantic Scholar, (1992).

8. H. Baer, et al., Higgs and superparticle mass predictions from the string theory landscape.

Cornell University, (2018).

9. David Kaplan video Supersymmetry. CERN, (2021).

10. G. Larsen, Y. Nomura, and H. Roberts, The cosmological constant in the quantum multiverse.

Cornell University, (2011).

Images retrieved from: 1. Graphic Illustration by Komal Grewal `23 2. www.flickr.com/photos/bnsd/11253401126 3. Graphic Illustration by Komal Grewal `23 4. commons.wikimedia.org/wiki/File:Views_of_the_LHC_tunnel_sector_3-4,_tirage_2.jpg

13

Traditional Chinese Medicine—a Hidden Science?

EAN TAM `23

Figure 1 A street vendor in Vancouver, Canada displays an extensive selection of herbs and other traditional Chinese medicine products.

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Figure 2 A variety of dried plant and animal parts on sale, including mushrooms, coiled snakes, and turtle shells.

Introduction On May 25th, 2019, the World Health Organization (WHO) adopted the eleventh version of the International Classification of Disease, also known as the ICD-11, which provides medical practitioners with diagnostic codes. For example, if a patient has cholera, the doctor will enter the corresponding ICD-11 code, 1A00, into a database. Given the scale of the ICD, the database and codes allow institutions and nations to track mortality and morbidity statistics, as well as resource allocation. In 2020, Stony Brook’s Distinguished Professor of Pharmacological Sciences Arthur P. Grollman criticized the ICD-11. Grollman’s point of contention is the ICD-11’s inclusion of health conditions treated by traditional Chinese medicine, also known as TCM. Grollman finds the inclusion of TCM to be counterproductive to the advancement of modern medicine (1).

Those who share Grollman’s point of view argue that TCM is a pseudoscience, and by providing diagnostic codes for TCM conditions, the WHO is directly supporting the use of TCM in the modern world. It is important to distinguish that the ICD-11 is not expressing which specific TCM products should be used; rather, it recognizes the the health conditions that may only be treatable by TCM. For example, the ICD-11 references insomnia and tinnitus as treatable conditions of TCM, but it also references traditional East Asian conditions. Conditions include qi deficiency (lacking in essential life energy) and yin and yang disruptions (imbalance in opposing forces within the body) (1). Whereas insomnia and tinnitus have possible treatments in modern medicine, conditions involving qi and yin-yang do not. Thus, by giving official recognition to conditions exclusive to TCM, the ICD-11 acknowledges whichever TCM product is hailed to be a solution. The concern of TCM opponents is that the research and development behind TCM is lacking or unsafe. In order to address this concern, the following two issues should be considered: the adequacy of studies of TCM’s molecular basis and the transparency of sourcing and environmental implications.

Although the phenomenon of qi has no scientific bearing, the idea of qi and TCM use is very much embedded in East Asian cultures, where TCM is used as home remedies or even recommended medical alternatives.

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Figure 3 A batch of pangolin scales discovered in Cameroon. These scales were among the three metric tons seized and later burned by the Cameroonian government in 2017 to deter illegal traders.

Studying the Molecular Basis of TCM Passed down from generations, TCM as it is used today is built upon centuries of homeopathic-oriented treatments from East Asia. Although referred to as traditional Chinese medicine, TCM includes many practices and ingredients used in other countries like Japan and Korea. TCM revolves around the idea of qi, a term to denote the vital energy within the human body (2). Although the phenomenon of qi has no scientific bearing, the idea of qi and TCM use is very much embedded in East Asian cultures, where TCM is used as home remedies or even recommended medical alternatives.

In 2016, 15.8% of the medical services delivered in China were TCM, and TCM “hospitals” and clinics provided care for approximately 962 million Chinese citizens (3).

Granted, when TCM products were first established centuries ago, the users most certainly did not comprehend the importance of the molecular basis behind medicine. But with time and given the advent of new technology, analysis of proposed medicine is commonplace. TCM is no exception, although the researchers are candid in acknowledging the limited research supporting the benefits of TCM. A 2020 meta-analysis published in the Journal of Pain and Symptom Management gathered studies concerning TCM used for relieving pain in breast cancer patients being treated with aromatase inhibitors (AI). AI treatment can lead to aromatase inhibitor-associated musculoskeletal symptoms (AIMSS), characterized by pain in muscles and joints. All of the studies analyzed were randomized controlled trials, and the breast cancer patients self-reported pain levels from AMISS. Across the studies, TCM products administered to the research participants ranged from herbal remedies to acupuncture. The meta-analysis pinpointed four of these TCM products that alleviated AIMSS-related pain: tiger bone powder, ear acupuncture, Bushen Qiangjin capsules, and Yi Shen Jian Gu (YSJG) granules (with the latter two composed of a mixture of herbs).

There were significant differences in self-reported pain levels between the

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treatment groups and their respective placebo counterparts. For example, the group of patients who took YSGJ reported a 50.2% decrease in pain compared to the 26.9% decrease in pain in the placebo group (4). While such data does lend some support for these TCM products as an effective treatment, it is important to note that self-reporting is subjective and the sample sizes in the studies never exceeded 77. Moreover, this meta-analysis of various TCM products accomplished nothing more than observing the effects of TCM without explaining their scientific basis. The study admitted in its final sentence, “However, further investigation on the molecular pathway involved and an in-depth safety profile is needed” (4). But for advocates of TCM, not all is lost.

COVID-19 Studies The COVID-19 pandemic caused by the SARS-CoV-2 has led to a global search for vaccines and therapeutics. In China, the pursuit for therapies to treat COVID-related symptoms has included TCM. From this research, the benefits of at least two TCM products, Lianhua Qingwen and Jinhua Qinggan, have not only been observed but also explained on a molecular basis.

Lianhua Qingwen capsules are made of thirteen Chinese medicines including the fruit of the forsythia plant and granules of gypsum fibrosum stone. In a randomized, controlled experiment with 284 symptomatic COVID-positive patients, a 14-day regiment of 12 Lianhua Qingwen capsules a day improved the rate of recovery of fever, fatigue, and cough (2).

A separate study revealed the in vitro effects of Lianhua Qingwen on slowing down the replication of SARS-CoV-2 and preventing cytokine storms— life-threatening inflammatory responses by the body due to viral infection (2).

Jinhua Qinggan granules are composed of twelve Chinese medicines. Jinhua Qinggan was used to treat H1N1 and has now been used for

COVID-19. In a controlled experiment with 123 patients, Jinhua Qinggan improved common symptoms like cough, fever, and fatigue, but it was also said to lessen the patients’ anxiety. The reported molecular basis: Jinhua Qinggan binds to ACE2—a transmembrane protein that is effectively SARSCoV-2’s gateway into the cell—and blocks the virus’ ability to replicate in other cells (2).

Although the researchers provided molecular explanations, they came far from isolating the specific compound(s) in each treatment that led to the observed therapeutic benefits. Recall, Lianhua Qingwen and Jinhua Qinggan are composed of thirteen and twelve different Chinese medicines, respectively. Thus, despite the positive results, the researchers were left unable to pinpoint which component was the definitive cause. Even more troubling, researchers at the Nanjing University of Chinese Medicine issued a response to the study of Lianhua Qingwen, questioning the recommendation that Lianhua Qingwen be used against COVID-19. They wrote, “However, the use of [Lianhua Qingwen] is not preferred because of their unclear representation of absorbed bioactive compounds (ABCs). Furthermore, their unabsorbed compounds, concentrations of absorbed compounds, excipients, metal ions, and impurities in crude extract may lead to false responses ex vivo after administration” (5). Additionally, further research is needed given the small sample sizes of the patient experiments (no greater than 300) and the lack of consideration into drug interactions, diversified demographics, and length of course of treatment. Conversely, the Moderna and Pfizer COVID-19 vaccine trials involved 30,420 and 43,548 participants, respectively (6). Although pregnant women and younger children were not examined in these two vaccine trials, the volunteer pool was diversified in age, health conditions, and race.

Risks of Taking TCM In a paper published in EMBO Reports, Grollman and Marcus documented the WHO’s odd affinity for TCM. They explained that regardless of TCM’s socio-economic benefits (which the WHO leadership under Margaret Chan highlighted), the adequate research in TCM’s favor is simply not present. Given that 88% of the UN member states do not have the capabilities to carry out research on their own, the WHO is responsible for disseminating reliable information for a global audience (7). Yet, the WHO may fail to do so. For instance, it often overlooks that many TCM products contain ingredients that are dangerous to humans, such as aristolochic acid, a herb found in many TCM products. Research has found that aristolochic acid can lead to liver cancer in mice “in a similar fashion to the genetic pathogenesis of human liver cancers” (8). The researchers also concluded that Chinese patients were most at risk simply because Chinese patients are more likely to consume the TCM products containing aristolochic acid (9).

Outside of the Lab: Environmental Implications The second issue concerning TCM is sourcing and environmental implications. In studies performed with TCM products sold in Australia, half of the TCM samples the researchers analyzed contained DNA from animals and plants that the product labels had not even listed. Some of those animals were endangered, and some of the included plants were poisonous (1). One of the potentially dangerous plants include Ephedra, which was banned in the United States after it was found responsible for the death of Major League Baseball player Steve Bechler. Ephedra was one of the herbs included in the Lianhua Qingwen and Jinhua Qinggan capsules used for COVID-19 therapeutic studies, and it was described to be one of the most beneficial ingredients in Jinhua Qinggan (2).

Additionally, the sourcing of TCM products comes under scrutiny for damaging the conservation efforts of at-risk species. Examples include the Malaysian sun bear, which is illegally targeted and sourced for a variety of TCM products, their bile being the most prized. In Malaysia, sun bears are

found with their meat, paws, and gallbladders removed—all desired TCM products. Other body parts like bones and skin are seen as trophies and are collected as well. The poaching of sun bear parts is broadcasted on Facebook; these parts are subsequently sold at local markets. Sun bears that survive immediate butchering may be left injured from traps or kept as pets.

Without much regard to its illegality, domestic and foreign poachers remain attracted to the TCM business existing in Malaysia (9). Another prime example is the pangolin species, which is near extinct because poachers seek pangolin scales and other body parts for TCM (3). From 2010 to 2015, an estimated 100,000 pangolins were illegally trafficked. Pangolins have also been found to be a possible source of the SARS-CoV-2 virus (10). Even with regulations and animal-protection laws, the blackmarket business for TCM will result in the further endangerment of at-risks species and increased possibility of zoonotic diseases.

Conclusion The WHO’s decision to include health conditions treated by TCM in the ICD-11 has warranted concern from some scientists. They argue that recognizing such conditions may pave the way for TCM to achieve broader acceptance into modern healthcare. This is worrisome given that TCM products are so extensive in its applications and ingredient sources, yet many TCM products lack a definitive molecular basis. The United States National Institutes of Health warns consumers that TCM studies in general are of poor quality. This was seen with the Linhua Qingwen and Jinhua Qinggan experiments; the products were reported to be effective therapeutics for COVID-19 patients, but the research may not contain the necessary elements of a drug trial, such as large and diverse sample sizes and, most importantly, a clear mechanism of action.

In addition, the studies that support TCM ignore its possible dangers.

This includes the contamination of products by extraneous ingredients, incorporation of toxic components like aristolochic acid, and black market business fueling TCM. All three of those concerns have been highlighted in more extensive research, particularly by researchers outside of China.

The ICD-11 will come into effect in 2022. It is unlikely that sufficient research with the appropriate components of drug trials could be published before then: the field of TCM is too large, and time is lacking. Although the WHO has made its decision, for now, TCM remains a hidden science.

References 1. D. Cyranoski, Why Chinese medicine is heading for clinics around the world. Nature 561, 448450 (2018). doi: 10.1038/d41586-018-06782-7.

2. Q. Li, et al., The role played by traditional Chinese medicine in preventing and treating COVID-19 in China. Frontiers of Medicine 14, 681–688 (2020). doi: 10.1007/s11684-020-0801-x.

3. Y. Wang, et al., Knowledge and attitudes about the use of pangolin scale products in traditional Chinese medicine (TCM) within China. People and Nature 2, 903-912 (2020). doi: 10.1002/ pan3.10150.

4. C. Long Poo, et al., Effect of traditional Chinese medicine on musculoskeletal symptoms in breast cancer: a systematic review and meta-analysis. Journal of Pain and Symptom Management 20, (2020). doi: 10.1016/j.jpainsymman.2020.11.024.

5. X. Huang, et al., Letter to the editor in response to the articles ‘Lianhuaqingwen exerts anti-viral and anti-inflammatory activities against novel coronavirus (SARS-CoV-2)’ and ‘Liu Shen capsule shows antiviral and anti-inflammatory abilities against novel coronavirus SARS-CoV-2 via suppression of NF-κB signaling pathway.’ Pharmacology Research 163, 1-4 (2021). doi: 10.1016/j. phrs.2020.105289.

6. C. Corti, et al., Current perspectives: SARS-CoV-2 vaccines for cancer patients: a call to action.

European Journal of Cancer, 1-25 (2021). doi: 10.1016/j.ejca.2021.01.046.

7. A. Grollman and D. Marcus, Is there a role for botanical medicines in the twenty-first century?

EMBO Reports 21, 1-3 (2020). doi: 10.15252/embr.202051376.

8. Z. Lu, et al., The mutational features of aristolochic acid-induced mouse and human liver cancers. Hepatology 71, 929-942 (2019). doi: 10.1002/hep.30863.

9. L. Gomez, et al., Illegal trade of sun bear parts in the Malaysian states of Sabah and Sarawak.

Endangered Species Research 41, 279-287 (2020). doi: 10.3354/esr01028.

10. T. Zhang, et al., Probable pangolin origin of SARS-CoV-2 associated with the COVID-19 outbreak. Current Biology 30, 1346-1351 (2020). doi: 10.1016/j.cub.2020.03.022.

Images retrieved from: 1. https://commons.wikimedia.org/wiki/File:2016_366_287_Traditional_Chinese_Medicine_ (30227026751).jpg 2. https://commons.wikimedia.org/wiki/File:Traditional_Chinese_medicine_in_Xi%27an_market.jpg 3. https://commons.wikimedia.org/wiki/File:Pangolin_scale_burn_in_Cameroon._Credit-_Kenneth_Cameron_-_USFWS_(2)_(32575640450).jpg

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Leeching into the Past:

A Modern-Day Revival of Medicinal Leech Therapy HARSHINI SURESH `23 Upon mention of the bloodsucking, predatory worms known as leeches, a sense of fear and revulsion is instantly elicited from the general public. Distant cousins of the earthworm, leeches are freshwater parasitic worms that feed on the blood of both animals and humans. Leeches were widely used in a practice called bloodletting, wherein physicians applied these worms on patients to restore balance of bodily fluids, or humors, and eradicate illness. The entire body was thought to benefit from leech therapy, exemplified by its usage in treating headaches, ear infections, and hemorrhoids (1-2). The effectiveness of this practice was later disproved via clinical research studies; thus, leeching began to decline in popularity. Recently, the use of leeches has re-emerged in modern medicine, particularly in select cases of reconstructive surgery (3). Despite their frightening connotation, these creepy crawlers possess healing properties that, if harnessed, can save patients’ limbs, if not lives.

Bloodletting, an ancient medical treatment in which blood was withdrawn from the veins of a patient using leeches, began around 3000 years ago in societies around the world, as depicted in the writings of esteemed Chinese and Tibetan physicians, African shamans, and Mayan

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priests. The implementation of this therapeutic practice into Western medicine originated from the Greeks, who passed it onto the Egyptians, and in turn, bloodletting was slowly integrated into Roman society. Hippocrates (460–370 BC), an ancient Greek physician and prominent figure in medicine, founded the humoral theory, which proposed that an imbalance in humors (body fluids) such as blood, phlegm, black bile, and yellow bile, caused many physical and mental illnesses. To combat this imbalance, Hippocrates proposed bloodletting, purging, catharsis, and diuresis as means to remove excess humor. Galen of Pergamum (129–200 AD), a famous Roman physician, declared blood the most influential humor; through his ideas and writings, bloodletting by leeches became the standard treatment for a wide range of conditions including mental illnesses, eye disorders, cysts, boils, pneumonia, and tonsillitis (2).

Hirudo medicinalis, a European medicinal leech, was typically used for bloodletting; at each feeding, this leech was engorged by approximately five to ten milliliters of the patient’s blood (1-2).

Many physicians ardently believed in bloodletting, notably Dr. Benjamin Rush (1745-1813). He had a simplistic view of disease: all febrile (fever-related) illnesses were due to the convulsive action of blood vessels. As a result, Dr. Rush often removed large amounts of blood several times to dampen

the excitement of the patient’s vasculature. Towards the beginning of the ulant and antiplatelet nineteenth century, leeching became the most common medical procedure agent that acts to prevent in both Europe and America as a means of preventing or treating infecblood clots and reduce the tion and disease. In some cases, patients lost as much as 80 percent amount of congested blood in of their blood in a single leeching session (2). The popularity tissues. Other chemicals in the saliva of bloodletting waned as this mode of treatment was implipromote blood flow to the damaged area cated in the deaths of both Charles II of England and United and eradicate stagnation, thus preventing tissue States President George Washington (2). necrosis or death in the reattached body part (3, Due to the implication of the practice in various deaths, researchers 6). In these cases, one to two leeches can be applied to began to study the proposed benefits of bloodletting. An increasing numthe area to feed for approximately 30 minutes, ingesting ber of research studies debunked the about 15 grams (0.5 ounce) of blood efficacy of this practice, notably one (1). Once fully engorged, the leech study conducted by Dr. Pierre Louis, detaches itself and the appendage widely regarded as the father of epbleeds for an average of 10 hours, idemiology. Dr. Louis examined the resulting in 120 grams of blood clinical outcomes of 77 patients with lost. When the bleeding has almost acute pneumonia and compared stopped, another leech is applied to the results of patients treated with the appendage to stimulate angiobloodletting in the early phase versus genesis, or the development of new late phase of illness. Statistical eviblood vessels, while existing veins dence from his experiment showed widen and accommodate more blood that bloodletting was ineffective for flow (3-6). In a study conducted by pneumonia, a febrile illness, diminHebrew University-Hadassah Mediishing the value of this treatment in cal School researcher Dr. Mumcuogsociety. Through a series of studies lu, 15 patients afflicted with venous with bacteria, German clinician Dr. congestion of skin flaps received Koch established the germ theory, treatment consisting of application which stated that pathogenic microof an average of 9.2 leeches to each organisms can cause disease. With flap. The tissue of these patients the advent of this scientific theory, gradually regained a working cirthe current basis for many diseasculation network of new blood veses, the humoral theory of disease sels and a good blood supply within was invalidated, and thus, the use of three to five days (7). This treatment bloodletting slowly decreased (2-3). is also painless and promotes healToday, medicinal leeches are ing: when a leech bites, it releases primarily utilized in Western meda naturally occuring anesthetic that icine for reattachment operations, numbs the specific area and a local skin grafts, and reconstructive plasvasodilator to improve blood suptic surgeries (6). These procedures ply in that area. Additionally, to reutilize microsurgical techniques duce the risk of infection from leech involving a microscope and other therapy, medicinal leeches are bred specialized instruments, and have a specifically for medical use in leech 98% success rate (3). In rare cases, farms, sanitized before attachment however, a flap or reattached body to the patient, and only used once.

Figure 1 The ancient application of leech therapy in the late 1800s. part develops venous congestion.

After they have been fed, the leeches This dangerous condition occurs when tiny, thin-walled veins involved in are cropped off, anesthetized, and disposed of as medical waste (4, 6). The these microsurgical procedures cannot carry an appropriate amount of U.S. Food and Drug Administration approved use of leeches in 2004 for blood away from the surgical site. Consequently, deoxygenated blood pools localized venous congestion after surgery, acknowledging these organisms in the veins and cannot flow back to the heart and lungs for reoxygenation. as living medical devices (3, 6).

If this condition is left untreated, carbon dioxide accumulates in the stagA growing number of research articles has been published on the nant blood and causes tissue death. To remedy this condition, physicians various therapeutic applications of leeches, particrecommend medicinal leech therapy (3-4). ularly in cardiovascular disease.

Leech saliva contains Clinical trials have shown that hirudin, an anleech therapy also serves as ticoaga good treatment option for osteoarthritis, a common degenerative joint disease. Dr. Michalsen and his team at the

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Charité University Medical Center in Berlin reported that the anti-aggregate and anesthetic properties contained in leech saliva better reduced pain and inflammation at the affected knee joint when compared to topical gels in patients with osteoarthritis (9, 12). Implications of leech therapy in cancer are also being explored due to the platelet inhibitors and special enzymes within leech saliva. While the anticoagulative properties of hirudin prohibit the use of this treatment in certain blood cancers, recent evidence has suggested benefits in other cancers. According to Dr. Abdualkader and his colleagues, after injecting leech saliva directly into mice, they observed that the therapy helped prevent the colonization of lung cancer cells (89). Furthermore, chemicals like hirudin are being derived from leech saliva and made into pharmaceutical drugs that can treat numerous conditions like hypertension, varicose veins, and skin diseases such as psoriasis and chronic ulcers (9).

Lastly, leeches have also been shown to help with the chronic condition diabetes. The progression of diabetes can lead to diseases of the blood vessels that limit blood flow to the extremities. When blood flow is severely restricted, the affected tissue can potentially die. For millions of people around the world, extremity loss from diabetic complications is a major concern. This necrotic process can be effectively stopped by increasing circulation to the affected areas without the risk of blood clots. According to Dr. Kunal Jha and his research team from the Kalinga Institute of Dental Sciences in Odisha, India, hirudin can relieve pressure on the heart and cardiovascular system by making the blood flow of diabetic patients more fluid (4, 8-9). In a case study involving a 60-year-old woman with diabetes, leech therapy was able to help save her foot from amputation (10). Researchers have discovered that using as few as four leeches in one session can help reduce the risk of amputation.

Overall, leech therapy is seeing a revival in the twenty-first century due to its relatively simple and effective means of preventing complications after surgery as well as its application in many illnesses, namely heart disease, cancer, and diabetes. Having said that, there are some risks involved with this mode of treatment. There is a small risk of a bacterial infection from leeches because these organisms contain bacteria in their gut that help them digest blood. To prevent infection, the doctor will administer an antibiotic during the procedure (4-5, 11). For this reason, people who are immunocompromised by autoimmune disease and environmental factors are not good candidates for leech therapy (11). In some cases, a person will discover during or after leech therapy that they are allergic to leech saliva (4, 11). If such complications arise, the patient will know immediately and will no longer be a candidate for this treatment method.

Leeching was perceived as the panacea for numerous medical disorders including nervous system abnormalities, skin diseases, and infections, and perpetuated in ancient medicine for centuries. Yet as more researchers closely examined the proclaimed benefits of leeching therapy, they found that this mode of treatment was ineffective, citing the newly established germ theory. Surprisingly enough, modern medicine has seen a recent revival in the application of leeches for treating complications of reconstructive surgery. As our scientific knowledge of illness and its associated mechanisms continue to be refined, medieval methods of treatment like bloodletting may be revived. Although bloodletting may not rise to the position of being the primary course of treatment for many conditions, further research may reveal greater applications in risk reduction and complication prevention. Potential solutions in medicine laid out by our predecessors may be hiding in plain sight, waiting to be rediscovered.

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References 1. A. Augustyn, et al., Leeching. Encyclopaedia Britannica, (2018).

2. G. Greenstone, The history of bloodletting. BC Medical Journal 52, 12-14 (2010).

3. J. Freiman, When leeches are used in modern medicine: have we turned back time?. U.S. News, (2018).

4. B. Krans, What is leech therapy?. Healthline, (2017).

5. J. Edwards, Leech therapy - information for patients. Oxford University Hospitals NHS Foundation Trust, (2017).

6. M. Renault, Modern medicine still needs leeches. Popular Science, (2019).

7. K. Mumcuoglu, et al., The use of the medicinal leech, Hirudo medicinalis, in the reconstructive plastic surgery. The Internet Journal of Plastic Surgery 4, 1-9 (2006). doi: 10.5580/3c6.

8. K. Jha, et al., Hirudotherapy in medicine and dentistry. Journal of Clinical and Diagnostic Research 9, 5-7 (2015). doi: 10.7860/JCDR/2015/16670.6918.

9. A. Abdualkader, et al., Leech therapeutic applications. Indian Journal of Pharmaceutical Sciences 75, 127-137 (2013).

10. S. Zaidi, Unani treatment and leech therapy saved the diabetic foot of a patient from amputation. International Wound Journal 13, 263-264 (2016). doi: 10.1111/iwj.12285.

11. A. Litwinowicz and J. Blaszkowska, Preventing infective complications following leech therapy: elimination of symbiotic Aeromonas spp. from the intestine of Hirudo verbana using antibiotic feeding. Surgical Infections 15, 757-762 (2014). doi: 10.1089/sur.2014.036.

12. A. Michalsen, et al., Effectiveness of leech therapy in osteoarthritis of the knee: a randomized, controlled trial. Annals of Internal Medicine 139, 724-730 (2003). doi: 10.7326/0003-4819-139-9200311040-00006.

Images retrieved from: 1. https://commons.wikimedia.org/wiki/File:A_medical_practitioner_administers_leeches_Wellcome_L0041637.jpg

Graphics created by Komal Grewal `23

X-RAY DIFFRACTION PROVIDES A NOVEL GATEWAY FOR ANALYZING MUMMIES SOORAJ SHAH `24 Since the 20th century discovery of the tomb of King Tutankamun, the excitement around discovering mummies has been a topic of controversy, particularly regarding how the mummies are handled once they are discovered. Unwrapping and disrupting the mummies’ final resting place is considered to be invasive. A study by Dr. Stuart Stock, a professor within the cell and molecular biology department at Northwestern University, used X-ray diffraction as an alternative to physically unraveling a 2,000 year old mummified child in order to investigate the contents within.

At the Argonne National Laboratory, researchers inferred that there were several objects within the mummified body that were placed with it for the afterlife. CT scans combining a series of X-ray measurements taken at different angles helped to produce a 3D image of the mummy. The scans revealed areas of density where X-ray diffraction had the highest chance of finding the materials. Next, X-ray diffraction was conducted by shining an X-ray beam through the mummy at these “dense” areas and observing the resulting pattern.

This study yielded a plethora of details about the mummy without even touching it. The cause of death was indeterminate as there were no visible damage to it. An amulet buried with the child was made of calcite, which allowed researchers to determine when and where it originated. In addition, the mummies’ dental analysis revealed the absence of adult teeth, further proving that the mummy was indeed a child around five years of age.

The extensive results of this study exhibit the validity and efficiency of X-ray diffraction and CT scanning as viable techniques to examine mummies while keeping them intact. Future research can be focused on perfecting this method, providing a pathway and precedent for other investigations regarding mummies.

Figure 1 (above) Use of X-ray diffraction allows researchers to uncover contents within a

Figure 1 (below) An example of a cave excavation site at Manot Cave, where the tools and

mummy while keeping it intact.

1. Stock, R.S., Stock K.M., and Almer D.J., Combined computed tomography and position resolved X-ray diffraction of an intact Roman-era Egyptian portrait mummy. The Royal Society 30, 172 (2020). doi: 10.1098/rsif.2020.0686.

2. Image retrieved from: pixabay.com/photos/history-egypt-sarcofaag-pyramid-1901078/

equipment are similar to those used at the Chiquihuite Cave.

THE EARLIEST HUMAN APPEARANCES IN THE AMERICAS YUKTA KULKARNI `22 Humans have populated Earth for hundreds of thousands of years, mainly inhabiting areas in East and South Africa. It was thought that humans had first arrived in the Americas around 15,000 years ago. However, new findings from excavations at Chiquihuite Cave in central-northern Mexico provide evidence that humans could have been present thousands of years earlier than originally predicted, an estimation of about 33,000 years ago.

Chiquihuite Cave is located in the Astillero Mountains approximately 1,000 meters above the floor of the valley and has multiple excavation sites.

Two strata, or layers of rock, were identified to be used as chronostratigraphic markers (marking the age of the strata with respect to time). From these strata, bones, charcoal, and sediment were used for radiocarbon dating and optically stimulated luminescence dating. One younger stratum was estimated to be around 16,000 years old. The other stratum was gauged to have been formed before the Last Glacial Maximum (LGM), which is the last time that the glaciers were at their greatest size, around 33,000 years ago. The researchers deduced that the chronological sequence specified by the samples agreed with the composition and arrangement of the strata.

Further evidence that demonstrates early human occupation are the stone tools discovered in the older stratum. Stone morphed into unnatural shapes

21 • ANTHROPOLOGY

indicates that something existed at this location to carve them. Additionally, extractions were executed on samples to test for environmental DNA. Researchers found that during the LGM era, a mix of forest species such as junipers, firs, pines, and grasses were present.

Strata chronostratigraphy, the presence of stone tools, and a lush environment all lead to the conjecture that humans were living in the Americas more than 30,000 years ago. It is also believed that humans were present here frequently, possibly as a result of migratory behaviors.

Since the cave is located at a high elevation, any humans that may have passed through were acclimated to the environment. More excavating and DNA sampling must be done to confirm the presence of humans. For now, it is amazing to think that the first human in the Americas lived tens of thousands of years ago, a simple idea that could change the history of humans as we now know it.

1. C. Ardelean, et al., Evidence of human occupation in Mexico around the Last Glacial Maximum.

Nature 584, 87-92 (2020). doi: 10.1038/s41586-020-2509-0.

2. Image retrieved from: commons.wikimedia.org/wiki/File:MANOT_CAVE_EXCAVATION.JPG 3. Image retrieved from: pixabay.com/photos/sand-sand-texture-sand-seamless-1545316/

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Heterozygous Advantages in the Modern World

CHRIS CIZMECIYAN `24

Diseases such as the bubonic plague, malaria, cholera, and tuberculosis have changed the course of history and human evolution multiple times. While the aforementioned diseases have continued to affect those in the modern world, humans have been fighting back one nucleotide base at a time. Heterozygous advantages have arisen around these diseases, with individuals only expressing half or diminished forms of genetic illnesses that compromise the health of millions of individuals globally. These genetic mutations have stood the test of time, showcasing their advantageous nature in certain regions. However, when people with these heterozygous advantages leave their native lands, medical problems associated with their genetic mutations may affect their health or that of their children. By bringing more awareness towards isolated genetic mutations, we can better understand history, social pressures for developing and developed nations, and how we can model medicine to better suit those with genetic anomalies.

Hemochromatosis and Resistance to the Bubonic Plague Iron can be as detrimental as it can be beneficial, since it can exchange electrons with other elements and create free-radicals. Iron, unlike other metals and macronutrients, is stored due to evolutionary advantage and its quotidian utilization. For instance, iron’s utilization ranges from mitochondrial electron exchange to oxygen transport as the central atom of hemoglobin in red blood cells (RBCs). Maintaining a proper iron concentration is imperative due to its omnipresent utilization, so avenues of potential loss of blood are accounted for with dietary iron absorption, and the iron that is stored in aged or damaged RBCs is recycled by macrophages. However, due to its impulsive exchanges of electrons, iron supply is restrained by meticulously mediated intercellular and intracellular transport processes. Hemochromatosis is an autosomal recessive disease that bypasses these checks and balances, resulting in the body’s absorbing all ingested iron and not secreting the excess. However, hemochromatosis, much like iron, has its own positive and negative health impacts. For instance, some positive effects include a reduced risk of developing cardiovascular plaque, neurological diseases, and reduced iron levels within macrophages. On the other

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hand, adverse effects include oxidative damage to the heart, liver, and pancreas alongside joint pain, chronic fatigue, and jaundice (1).

The disproportionate occurrence of hemochromatosis in people of Northern European descent has sparked many theories, but the main one holds the Vikings responsible (2). Their conquest swept far and wide, ultimately trickling to the close-knit communities of Europe that would allow for hereditary mutations to thrive. Once the bubonic plague spread to Europe and decimated the population, some of these communities continued to thrive due to the protective characteristics of hemochromatosis. Because the disease caused the body to safeguard every source of iron it could, there was very little for the bacterium Yersinia pestis to survive off (3). The macrophages of those with hemochromatosis also have reduced iron levels, so if the bacterium invaded the macrophage, it would not have had access to the iron it would need to survive. Thus, macrophages would keep the pathogen at bay while the body was producing the antibodies needed to survive.

While we may be in modern times, ancient techniques like bloodletting are utilized to treat hemochromatosis as it reduces iron levels in the circulatory system while reducing potential inflammatory responses in various parts of the body (2).

Sickle Cell Disease and Resistance to Malaria Sickle cell disease (SCD) is an autosomal recessive genetic disease that causes a single replacement of an amino acid, resulting in the deformation of hemoglobin into the hemoglobin S variant, which causes RBCs to deform. These RBCs have biconcave disc shapes when oxygenated, but sickle-like structures when deoxygenated (4). While there are inherent challenges associated with oxygen transport in hemoglobin S, the hemoglobin F variant is still able to transport oxygen (5). Consequently, some medical complications include cardiac problems, kidney problems, chronic pain, pregnancy problems, and even stroke or silent brain injury (6). The reason sickle cell disease has propagated for generations is that heterozygotes are typically asymptomatic, or have a normal physiological phenotype, despite the fact that RBC sickling still occurs (4).

Figure 1 This illustration showcases the misshapen hemoglobin found in patients with SCD compared to hemoglobin found in phenotypic homozygotes who do not carry the mutation.

SCD may be detrimental in its own right, but it is equally protective to ubiquitous as water. Without this reduction, those who suffer from G6PD heterozygotes with SCD who live in malaria-prevalent regions. The changes deficiency suffer from extraneous free radical concentration, which causin hemoglobin both affect how Plasmodium falciparum malaria interacts es oxidative stress and RBCs to lyse or break. With excessive RBC lysing, with RBCs and how the body reacts to the presence of malaria (4-5). The hemolysis can lead to illnesses such as favism, drug-sensitive anemia, and response in heterozygotes is quite remarkable because they are seemingjaundice in newborns. The genetic implications of G6PD are fascinating ly unaffected by the two forms of malaria – cerebral malaria and malarbecause it is a X-chromosome linked trait. While males only have one X ia with severe anaemia – that are otherwise immediately life-threatening. chromosome and can only be homozygous for the gene, females have two RBC sickling is a defense mechanism utilized by RBCs infected by malaria, X-chromosomes, resulting in heterozygous and homozygous phenotypes as they show much higher rates of sickling than for different variations of mutation expression. uninfected RBCs, possibly due to decreases in pH Thus, males who have the deficiency in the enFascinatingly, the relationship and oxygenation. The cells that sickle are then zyme experience the aforementioned symptoms, between malaria and G6PD ingested by macrophages, causing the protist to while females who may exhibit heterozygosity has somehow perpetuated the die before complete maturation and circulation are less likely to, as half of their cells are still mutation into the modern world, throughout the body (4). with heterozygotes and individuals capable of normal G6PD activity. The presence Another form of defense is the upreguof the G6PD mutation correlates to occurrences with mitigated forms of the disease lation of hemoglobin F through medicated hyof malaria in a given region because of its selecsurviving despite the detrimental droxyurea, as it can transport oxygen within tive advantage, so the disease is most frequently effects of the mutation by itself.

RBCs without being equally susceptible to malarobserved in African, Asian, and Mediterranean ia. Also, by saturating the hemoglobin population countries (7). with the fetal variant instead, there is a reduced chance of being infected The main course of malaria begins at the liver and then moves to by malaria in the first place as hemoglobin S concentration is limited. With RBCs, which it uses as a host. The parasite prefers to infect younger cells this additional fortification, the parasite cannot mature and infect the enthat have higher concentrations of G6PD. However, the parasite sees all tire body, but it is still present within the system (5). Compared to heterocells as old in those who are deficient in G6PD. In addition to this protective zygotes, homozygotes without the protective mechanisms of SCD are susmeasure, malaria dislikes conditions with high oxygen levels. With the inceptible to die from malaria while homozygotes with the SCD mutation are creased concentration of free radicals caused by a lack of GSH, the parasite vulnerable to sickle cell health impacts. can’t handle the oxidative stress and dies. Fascinatingly, the relationship between malaria and G6PD has somehow perpetuated the mutation into Glucose-6-Phosphate Dehydrogenase Deficiency and Resistance the modern world, with heterozygotes and individuals with mitigated forms to Malaria of the disease surviving despite the detrimental effects of the mutation by Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-chroitself. Antimalarial drugs, like primaquine, function similarly to the protecmosome mutation resulting in mitigated production of NADPH and glutative attributes of G6PD deficiency as they too decrease GSH, subsequently thione (GSH). The latter is responsible for reducing H2O2 into H2O, which increasing the concentration of free radicals and inhibit the protist from ultimately converts something harmful (a free radical), into something as maturing and cause it to die before replication. Furthermore, it is imper-

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Figure 2 In addition to the previously mentioned regions, this figure illustrates that European countries such as Spain and Italy also have G6PD deficient patients.

ative that those who are tested for malaria are also screened for G6PD deficiency as those with the deficiency experience worsened symptoms when prescribed antimalarial drugs, as their hemolytic symptoms are exacerbated by anemia, which can be fatal (7).

Cystic Fibrosis and Resistance to Cholera and Tuberculosis Cystic Fibrosis (CF) is an autosomal recessive disease caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR is specifically responsible for encoding chloride channels that, when defective, can result in improper mucous secretions in the lungs, which increase the risk of pulmonary infections. These infections can result in respiratory failure, as the moist environment is a suitable habitat for bacterial infections to thrive (5). Within the last few decades, CF survival rates have increased in developed countries, with life expectancy rising to over 30 years of age. However, a substantial proportion of Europeans are still carriers of the genetic mutation, much to the bewilderment of scientists. Some theories to the continued inheritance of the mutation include potential heterozygous advantage against cholera, typhoid fever, and tuberculosis (TB) (8).

You may be able to hit two birds with one stone, but CF can protect humans from two diseases with one ineffective chloride channel. Bosch et al. examined the relationship between TB and CF heterozygosity rates in Brazil due to high rates of infection from TB, potential carriers of CF due to high European descent, and the presence of a specific TB strain in both the Americas and Europe. After utilizing multiple spatial patterns, researchers concluded that areas with the highest heterozygote populations had the lowest TB infection rates (8). The changes in chloride channels found in the lungs also apply to other organ systems, as the gut is equally affected and provides a defense mechanism against cholera. Deformed chloride channels in the colon are beneficial as they cannot become hyperactive, resulting in dysentery and severe dehydration. With only 50% of the chloride channels functioning adequately in heterozygotes, individuals infected with cholera would excrete lower amounts of water, which thus reduces the impact of dysentery. The inherent mutation is so beneficial in protection that even

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medicine utilized to treat cholera patients reduces the efficiency of chloride channel secretions and CFTR (5).

Conclusion Mutations are here to stay, but that does not mean that humans are not learning from them. The indicative evolution of our mutations is accompanied by our yearn to discover ways to treat these diseases. By researching the defense mechanisms constructed by mutations in individuals, medicine can evolve to match and apply such defenses into our medical arsenal. Researchers have already done so with antimalarial drugs and cholera medication, and because we are forever learning about the history and mystery behind our genes, we have become one step closer to victory against these diseases. While prospects for those with certain illnesses may be grim, there is always hope that this may be the generation to change it all, and the advancement of research methods showcases that there is more to be done and lives to be improved.

References 1. I. Hollerer, A. Bachmann, and M. Muckenthaler, Pathophysiological consequences and benefits of hfe mutations: 20 years of research. Haematologica 102, 809-817 (2017). doi: 10.3324/haematol.2016.160432.

2. B. Wertheim, The iron in our blood that keeps and kills us. The Atlantic, (2013).

3. A. Nouri, Hemochromatosis and the plague. American Association for the Advancement of Science, (2011).

4. L. Luzzatto, Sickle cell anaemia and malaria. Mediterranean Journal of Hematology and Infectious Diseases 4, 1-6 (2012). doi: 10.4084/MJHID.2012.065.

5. I. Withrock, et al., Genetic diseases conferring resistance to infectious diseases. Genes & Diseases 2, 247-254 (2015). doi: 10.1016/j.gendis.2015.02.008.

6. Sickle cell disease. National Heart, Lung, and Blood Institute, (2020).

7. A. Allahverdiyev, et al., Glucose-6-phosphate dehydrogenase deficiency and malaria: a method to detect primaquine-induced hemolysis in vitro. IntechOpen 57, 65-90 (2012). doi: 10.5772/48403.

8. L. Bosch, et al., Cystic fibrosis carriership and tuberculosis: hints toward an evolutionary selective advantage based on data from the brazilian territory. BMC Infectious Diseases 17, 1-8 (2017). doi: 10.1186/s12879-017-2448-z.

Images retrieved from: 1. https://upload.wikimedia.org/wikipedia/commons/thumb/8/86/Risk-Factors-for-Sickle-CellAnemia_%281%292.jpg/1196px-Risk-Factors-for-Sickle-Cell-Anemia_%281%292.jpg 2. https://upload.wikimedia.org/wikipedia/commons/9/97/Red_Blood_Cell_abnormalities_2. png 3. https://upload.wikimedia.org/wikipedia/commons/thumb/7/70/Sickle_Cell_Blood_Smear.

JPG/1200px-Sickle_Cell_Blood_Smear.JPG

Rethinking the Past:

An Analysis of Aboriginal Australian Agriculture MARTHA BRAUN `21 For a long time, the vast history of pre-colonial land use by Indigenous populations has gone unrecognized in Australia. The subject lacks public and academic interest, and education has historically provided a homogeneous picture of the nation’s first people. Previously, it was widely accepted that Aboriginal people were strictly hunter-gatherers, sustaining themselves with fishing, hunting, and foraging. However, archaeological and anthropological research has finally garnered enough attention to suggest this is an oversimplification. Some scholars have argued that the evidence points to widespread agriculture, an idea popularized by Bruce Pascoe’s Dark Emu, a nonfiction book including colonial accounts of Aboriginal Australians published in 2018. While many scholars support the claim that Aboriginals practiced agriculture prior to European arrival in the early 1800s, others criticize it as unfounded. Regardless, an analysis of Aboriginal methods of land management and their ecological impact does not require a restriction to the dichotomy of forager and farmer (5). Unfortunately, the consequences of continued marginalization and mystification

Figure 2 Pile of harvested wild yams (Discorea).

Figure 1 Themeda triandra, a native perennial grass, more commonly known as kangaroo grass.

of Indigenous lives, both past and present, may have unique significance as prevailing unsustainable land use practices contribute to ecological disruption. Although the complexities of historical Aboriginal land use and methods have been buried, we must look back to look forward to a more sustainable and just future.

A primary feature of Aboriginal Australian life that raises interest in their land use is the widespread use of various tuberous plants. The significance of these plants can be traced back to the early Holocene, when northern Australia and what is now New Guinea were a continuous landmass.

This geographic understanding, along with studies of genetic variability to understand dispersal histories of plants such as the greater yam (Dioscorea alata), led Tim Denham and his team to conclude that the Indigenous groups present at this time likely shared methods of horticultural experimentation and had an impact on plant distribution throughout northern Australia (1). Centuries later, colonists like Isaac Batey documented these methods. In his account, Batey noted the production of the yam daisy (Microseris lanceolata) using mounds of soil at right angles to a ridge’s slope (2). To him, this was conclusively the work of Aboriginal hands, and the description could be interpreted as soil terracing. If so, it may indicate land management using a technique that encourages efficient use of water and prevents soil erosion (3). Furthermore, ethnobotany, the study of a region’s plants and their practical uses through the traditional knowledge of a local culture and people, further supplements our understanding about yam utilization in Australia. In her research on root use by Aboriginals in southern Australia, ethnobotanist Beth Gott noted that many tuber plants propagate their shoots from the rhizome structure. Similarly, the yam daisy proliferates with the replanting of its crown (4). The roots also have dietary importance, being rich in carbohydrates and present year-round. In colo-

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Figure 3 Seasonal burning by Aboriginal people in the Yellow Water (Ngurrungurrudjba) wetlands.

nist accounts, there is evidence of deliberate replanting and consumption of these plants that support these ethnobotanical findings. According to Gott, this replanting could be considered a type of natural cultivation that had a noticeable impact on the continental distribution of yam species before European arrival (4).

Entries by colonists following their arrival describe encounters with Indigenous groups, documenting their engagement in additional methods of cultivation and features of the land. Many English colonists, such as G.T. Lloyd, expressed disbelief at the thick grasses, widespread mosses and spongy soil, likely maintained by the strong root systems of grasses (2).

These images of a productive landscape differ from the area now mythologized as a desolate outback (2). There is debate about the level of cultivation and domestication involved with native perennial grasses, but accounts suggest they were harvested and stored. Although the presence of grassland cultivation is not explicitly expressed, an account from Thomas Mitchell emphasizes the land resembling a cultivated one, with trees growing in rows, recently burned areas of land, and loose, black soil (5). The cultivated appearance of the land and observations of stockpiling are so prevalent in colonist accounts that anthropologist Norman Tindale constructed a map of the aboriginal grain belt based on locations of these observations (2).

According to Ian Chivers, a researcher of native grasses at Southern Cross University, cereal production systems were a feature of Aboriginal land use for thousands of years (2).

Aboriginal Australians also regularly utilized fire to burn areas of land under controlled conditions. As a traditional regimen, fire is understood to hold cultural significance in Aboriginal life, and the techniques were carried out with knowledge of the prevailing weather, growing season of particular plants, and local fauna. Thomas Mitchell and other colonists described the periodic burning as a tool of Aboriginal land use, with observed patterns of clear and burned land, presumably to maximize productivity in areas with fertile soils (2). This is consistent with a study conducted by Dean Yibarbuk

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and his team in northern Australia, which used experimental fires to analyze the ecological outcomes of traditional fire management practices. The research attributes the reduction of uncontrolled wildfire risk and maintenance of biodiversity to the periodic small-scale burnings at the study site, Dukaladjarranj, where Aboriginals have carried out traditional fire management practices for years. Specifically, the experimental fires, conducted with support of Aboriginal custodians, showed that this practice promotes biodiversity, encourages germination and regeneration, and minimizes the risk of uncontrolled fires by limiting accumulation of litter (6).

Scholars such as Pascoe posit that the hunter-gatherer label appears to be a highly consequential misrepresentation that hides Aboriginal knowledge and achievement (2). Researchers such as Denham have also recognized the attachment to this stereotype (1). Dark Emu proposes that the oversimplification stems both from the dismissive language seen in colonist accounts as well as the destructive environmental transformations that came with colonialism. With the introduction of English pastoralism, livestock trampled the vegetation and consumed some native plants to eradication, exemplified by the disappearance of the yam daisy shortly after European arrival (2). The loss of these native plants, including the degradation of perennial grasses, not only removed a key nutritional source for Indigenous populations, but fundamentally altered the biodiversity of systems that kept soils absorbent and staved off flooding. European colonists also introduced more than 65% of the continent’s mono-cultures and crops grown in absence of other crops or plant species–reducing ecological health and biodiversity (2).

Analyzing evidence of Aboriginal Australian life through the lens of western progress has kept pre-colonial activities from entering present conversations on human land use. Perhaps one of the most prevalent themes that can be extrapolated from colonist journals is that the groups they came into contact with had a deeply interconnected and stable relationship with the land, based on maintaining balance with the environment rather than

dominance over it. The systems that have hidden Australia’s complex history also function on a global scale, as colonization and the marginalization of Indigenous groups is not unique to Australia. Despite the large overlap between Indigenous territories and the world’s remaining biodiversity, along with Indigenous knowledge on biodiversity and conservation, the erasure of their contributions to sustainable land use continues, as do the consequences (7).

Human land use has been a factor in the health of the biosphere for as long as humans have manipulated land, but it has been receiving renewed attention in the face of our current ecological crisis and for its role in climate change. Agriculture, forestry, and other land use account for 24% of global greenhouse gas emissions and often reduce ecosystem resilience (8).

Instead of recognizing and integrating Indigenous knowledge that is known to improve ecological resilience, large-scale conversations have a distinct lack of inclusion. This can be seen in popular media, such as the documentary “Kiss the Ground’’ on Netflix, which gained momentum for displaying seemingly groundbreaking techniques of regenerative agriculture in the context of climate change. The primary focus of the documentary is soil and ecological health addressing the effects of the transition to industrial agriculture. It presents changes to land use such as maintenance of native biodiversity, agroforestry, and perennials without acknowledging their Indigenous origins. Indigenous experiences are also often insufficiently incorporated into climate policy. James D. Ford and his colleagues note that in assessments by the IPCC, the leading international body for the assessment of climate change, the coverage of Indigenous relationships to the environment is not adequately represented in the group’s Fifth Assessment Report (AR5). Their analysis proposes a need for greater input from Indigenous leaders and a more robust consideration of traditional knowledge on the environment. The authors also acknowledge the “victim-heroes’’ portrayal of Indigenous peoples in both scientific and popular discourse that their communities are represented both as vulnerable and potential saviors, placing a burden on an already marginalized population. They emphasize the need to engage with colonial histories and the wide array of Indigenous experiences relating to climate change due to the influence these assessments have on policy considerations (10).

“Instead of recognizing

...For as long as humans have manipulated land...

We can begin to process a more comprehensive history by acknowledging the role of Indegenous populations in managing their environments.

The inclusion of Indigenous peoples and integration of their knowledge would allow for justice by emphasizing diverse perspectives, empowering and protecting their work, and adapting to climate change in a way that addresses cultural and geographical nuances. In Australia, this effort could take many forms. Shifting teachings on the continent’s history to create a conversation based on accessible and accurate information would make exploring the past more relevant to today. Increased attention to specific research areas could accelerate the reintroduction of yams, other root vegetables, and grasses that are native to the continent and primed for the local environment: naturally more drought resistant, resilient, and with potential to change the country’s production economy. This includes reestablishing plants that are known to improve soil health and sequester carbon. It could also include reviving traditional fire management as a tool for achieving long-term environmental stability through cooperative programs with Indigenous groups and long-term financial support for such programs (6).

Global changes would reflect similar ideas tailored to individual regions, and while the complexity of the challenges of transforming land use cannot be understated, reforming our principles and views on history could help shift the collective view on our part in the natural world. Accepting Indigenous knowledge and science on land use could help create positive ecological outcomes, promote environmental justice, and address climate change more effectively, all by working with the land and the communities that know it best.

and integrating

indigenous knowledge

that is known to improve ecological resilience,

large-scale conversations have a distinct lack of inclusion”

References 1. T. Denham, M. Donohue, and S. Booth, Horticultural experimentation in northern Australia reconsidered. Antiquity 83, 634-648 (2009).

2. B. Pascoe, Dark Emu: Aboriginal Australia and the birth of agriculture. 17, 21-23, 28, 38, 42-43, 103, 174-175, 194 (2018).

3. W. Wei, et al., The effects of terracing and vegetation on soil moisture retention in a dry hilly catchment in China. Science of the Total Environment 647, 1323-1332 (2019). doi: /10.1016/j. scitotenv.2018.08.037.

4. B. Gott, Ecology of root use by the Aborigines of southern Australia. Archaeology in Oceania 17, 59-67 (1982). doi: 10.1002/J.1834-4453.1982.TB00039.X. 5. I. Keen, Foragers or farmers: Dark Emu and the controversy over Aboriginal agriculture. Anthropological Forum 1, 1-24 (2021). doi: /10.1080/00664677.2020.1861538.

6. D. Yibarbuk, et al., Fire ecology and Aboriginal land management in central Arnhem Land, northern Australia: a tradition of ecosystem management. Journal of Biogeography 28, 325-343 (2002). doi: /10.1046/j.1365-2699.2001.00555.x.

7. V. Toledo, Indigenous peoples and biodiversity. Encyclopedia of Biodiversity 3, 1-23 (1999). doi: 10.1016/B978-0-12-384719-5.00299-9.

8. IPCC, Summary for policy makers. Climate Change 2014: Synthesis Report, 46 (2014).

9. J. Tickell and R. Tickell, Kiss the ground. Netflix, (2020).

10. J. Ford, et al., Including indigenous knowledge and experience in IPCC assessment reports.

Nature Climate Change 6, 349-353 (2016). doi: /10.1038/nclimate2954.

Images retrieved from: 1. https://www.flickr.com/photos/takver/6335934250/in/photostream/ 2. https://commons.wikimedia.org/wiki/File:MS_1960.JPG 3. https://www.flickr.com/photos/parksaustralia/9266959042/

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THE PRESERVATION OF PROTEINS AND LIPIDS IN ANCIENT MAMMOTH RIB BONES JOYCE CHEN ‘23 Despite significant technological advances in the past decade, a great deal of mystery still surrounds the ancient animals that once roamed the earth. In order to learn about these organisms, biologists study the biomolecules that are found within fossils. Biomolecules include proteins and lipids, and their preservation allows scientists to understand and trace evolution. Due to a lack of research on the topic, Dr. Caitlin Colleary of Virginia Polytechnic Institute and her team investigated the preservation of biomolecules in ancient mammoth ribs across several environments to understand how biomolecules are conserved in related species.

Several different mammoth ribs along with a modern African elephant rib were collected from various locations. The team aimed to compare the elephant bone fragment with the mammoth ribs. Also known as a maturation experiment, the bones were cut and heated in ovens for different time intervals, ranging from 24 hours to 91 days. Amino acids within the bone were measured using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and lipids were extracted from the bones for analysis. The presence of endogenous biomolecules such as amino acids and lipids help determine how well-preserved the fossil is; fossils that have the same amount of endogenous lipids as modern elephant bones are deemed as well-preserved, while fossils with exogenous lipids from external sources like soil are deemed as contaminated.

Additionally, the preservation of biomolecules is related to the environmental conditions in which the fossil was found. Factors like temperature seem to have a particularly large influence on lipid preservation. The team discovered that the mammoth bone collected from

a hot spring showed high levels of degradation due to the presence of high amounts of exogenous lipids. Meanwhile, the fossil from a permafrost area was the best preserved out of all of the collected bones due to the high levels of endogenous lipids. However, a bone from a channel deposit showed higher amounts of endogenous lipids than the permafrost bone. Thus, the burial environment has a large impact on biomolecule preservation.

Dr. Colleary and her research team’s study demonstrates the importance of the environment on biomolecule preservation within ancient fossils. Further studies will be conducted to take into account the contamination of fossils within their environment and how this plays a role in degradation of fossil bones.

Figure 1 Environmental factors such as temperature can play a large role in the conservation of biomolecules in fossils.

1. C. Colleary, et al., Molecular preservation in mammoth bone and variation based on burial environment. Sci Rep 11, 2662 (2021). doi: 10.1038/s41598-021-81849-6 2. Image retrieved from: https://images.pexels.com/photos/4095253/pexels-photo-4095253.jpeg

A ONCE THOUGHT EXTINCT SPECIES OF MICE REPOPULATES AFTER AN EXPLOSION SABAH BARI ’24 Mount Pinatubo was known for being a quiet volcano located on the most populated Island of Luzon in the Philippines. However, the calmness of Mount Pinatubo came to a halt on June 15, 1991 when the volcano erupted. The destruction of the explosive volcano negatively affected the wildlife on Luzon, except two main species of the Philippine forest mice.

Upon the eruption, a species of mice that was thought to be extinct had more than just survived it; they mass populated the area, becoming the most abundant mammal on Mount Pinatubo.

The discovery of the Apomys sacobianus mice is an example of how adverse effects of an explosion can still provide enough resources for these

Figure 1 A. sacobianus is larger in size than a typical mouse and has dark fur (not actual representation of A. sacobianus).

28 • LOST AND FOUND TAXONOMY

small mammals to thrive. The genetic material of several mice were similar enough for all to be assigned under the umbrella species name of Apomys sacobianus and were found either on the Lubang or Luzon Islands. As shown through genetic sampling, this species of mice was known for lacking stapedial foramen, which allows the researchers to suggest that any mouse that has the same carotid circulatory pattern may be a A. sacobianus from Mt. Pinatubo. After the researchers studied various anatomical features of the mice, such as the measurements of the mice’s maxillary, diastemal length, and braincase height, they concluded that the mice present on Mt. Pinatubo are variations of the species A. sacobianus known as A. Megapomys and A. lubangensis. These species are common and abundant on Lubang Luzon Island.

As ecologists understand the impact of the volcano eruption in the Philippines, the findings of the study suggest that A. sacobianus mice were repopulating the devastated area. This research illustrated how big, destructive effects on the ecosystem are not the end for organisms in the area, as small mammals can grow in population size. Therefore, these small mammals can be the start to a new beginning for an ecosystem to thrive in.

1. L. Heaney, et al. Two new species of Philippine forest mice (Apomys, Muridae, Rodentia) from Lubang and Luzon Islands, with a redescription of Apomys sacobianus Johnson, 1962. Proc Biol Soc Washington 126, 395-413 (2014). doi: 10.2988/0006-324X-126.4.395 2. Image retrieved from: https://unsplash.com/photos/frjYZxHZs_s

SPECIATION:

The Hidden Classification System TRAVIS CUTTER `21

...there are no presently known locations where the two birds share breeding grounds, so it is possible that reproductive isolation has occurred and that there is no hybridization zone...

Figure 1 A male Baltimore Oriole.

Introduction The difference between the American Robin and the Red-Tailed Hawk is evident. They are starkly different in size, ecological niche, the shape of their beaks, and other characteristics. It’s indisputable that these are fundamentally different animals. However, when one looks at more similar groups of animals, the nature of what defines a species seems to become exceedingly arbitrary. The vast majority of observers would likely never know whether or not two similar animals are in fact considered to be members of the same species or not.

Species that Aren’t - the Case of the Northern Oriole The Baltimore Oriole is perhaps best known as the mascot of the eponymous baseball team, but there was a time not too long ago where it didn’t even bear the name of the city that promotes it. Over the past several decades, there has been a debate over whether the Baltimore Oriole and its west coast cousin, the Bullock’s Oriole, constitute their own species, or whether they should be combined into a single species, called the Northern Oriole. The two birds are phenotypically similar, with an orange, black and white coloration, a similar silhouette, and they are capable of hybridization.

Hybridization is the ability for two species to successfully produce offspring together, and it is often a good indicator of whether or not two species are in fact one and the same. If hybrid offspring are exceedingly prevalent and can produce offspring of their own, then the two species are likely one and the same. In 1964, a study was published that declared that there was extensive hybridization of the two, with several subsequent studies backing up this assertion, and thus the Northern Oriole species was created less than a decade later.

While it is true that the two orioles can successfully hybridize, and have been historically known to do so in the American Midwest, recent studies have suggested that natural selection is against their hybridization.

Specifically, studies found that while said hybridization zone of the two has moved further west, more into Bullock’s Oriole’s territory, the westward shift has decreased in its rate, and the size of the zone has shrunk considerably since the 1970s. After sequencing the birds’ DNA, the researchers used genetic markers in their mitochondrial DNA and concluded that in the 1950s, the width of the hybrid zone for plumage traits was about 276 km and the width was 328 km for genetic similarities. At the time of the study in 2019-2020, these widths were determined to be 122 and 102 km, respectively.

This type of shift and reduction in a hybrid zone is not unprecedented, as similar findings have been made regarding the Indigo and Lazuli Buntings. The westward expansion of the Baltimore Orioles appears to have coincided with the expansion of cottonwood and willow trees—their preferred habitat—from 1930 to 1960, shortly before the study that concluded that hybridization was prevalent. The movement of the overall zone was possibly due to Bullock’s Oriole being more suited to more arid climates—

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the two birds fill separate ecological niches. Thus, as the climate changes in the area around the hybridization zone, the Bullock’s Orioles can move further westward toward climates they’re more suited to, making room for the Baltimore Orioles to expand their own territory (1).

Species that Are - the Case of the White-Faced Plover On beaches and in scrubland around the world, plovers are a fairly common sight. Many of them share similar characteristics, such as a color palette consisting of light brown, white, and touches of black, and they have similar body plans and behaviors. Some species of plovers can even look almost identical to an untrained eye. Two such plovers are found on the coast of China: the Kentish Plover found in the north, and the White-Faced Plover found in the south. Although originally described as separate species over a century ago, the White-Faced Plover was later made a subspecies of its northern cousin until a 2008 study suggested that molecular studies were needed to determine whether or not the White-Faced Plover was a separate species. In 2011, a study fully cemented the separation of the two after determining that the birds were phenotypically different enough to make the distinction. The differences between the birds were given a value on a scale of 1 to 4, with 1 being minor differences to 4 being exceptional differences. If the sum of all these values was equal to or greater than 7, then the two could be declared separate species. The total score of the differences between the Kentish and White-Faced Plovers was 8, indicating that they indeed were separate species, if only slightly. The study also made it clear that they did not see much genetic variation between the two species, but that a certain crudeness in their methods and equipment could have contributed to that assessment. Furthermore, just because the two birds were separate species, that doesn’t preclude the idea that they exchanged genetic information through occasional hybrids breeding with either of the two original species, in a process known as introgression. Ultimately, the study states: just because two animals are separate species, it doesn’t mean that they need to have exceptionally distinct genomes (2).

Several years after the separation of the White-Faced Plover from their northern cousins, a new pair of studies were published that saw the de novo sequencing of the Kentish Plover genome—the first sequence completed for any shorebird. The advent of a complete Kentish Plover genome allowed for greater analysis of the two birds, and the researchers concluded that the birds possessed little variation within their own species, but a great deal of variation in a few specific genomic regions between the two. After resequencing both birds, the researchers estimated that over approximately the last million years, the effective population size (a great indicator of genetic diversity) increased for the Kentish Plover while decreasing for the White-Faced Plover. The Kentish Plover was found to have an effective population size that was about 5.6 times greater than the White-Faced Plover, indicating that it is a much more genetically diverse species. The researchers suggested that the two birds could be subject to different methods of evolution due to this difference, with larger effective populations lending themselves to natural selection, and smaller effective populations lending themselves to genetic drift. Furthermore, while a 2011 study indicated that there was potentially a hybridization zone between the two species, later studies concluded that there are no presently known locations where the two birds share breeding grounds, so it is possible that reproductive isolation has occurred and there is a minimal hybridization zone, if any. This is notable because thorough reproductive isolation is considered to be a rather late occurrence in the speciation of birds. The fact that the two birds are thought to have diverged recently means that complete reproductive isolation is not expected. Thus, the two birds, despite appearing and acting similar, maintain their borders and remain distinct taxons (3)(4).

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Figure 2 A male Bullock’s Oriole.

Conclusion While many animals can appear very similar to one another, these surface-level traits have much less impact on the definition of what a species is than might initially be thought. Many invisible traits of animals lend themselves to analysis. Whether it be the nuanced composition of their genomes, migratory patterns, specific habitats of choice, or ability/inability to hybridize with similar organisms, these traits go almost completely unnoticed by most. Nevertheless, they define these animals and their relationships to each other. Given that the tree of life is overwhelmingly enormous, these details and the relationships they demonstrate could easily be lost to our perceptions if due diligence isn’t paid to even the most arbitrary of traits. Even if something can’t be easily seen, that doesn’t make it any less important to the natural history of the world.

References

1. J. Walsh, et al., Genomic and plumage variation across the controversial baltimore and bullock’s oriole hybrid zone. The Auk 137, 1-15 (2020). doi: 10.1093/auk/ukaa044.

2. F. Rheindt, et al., Conflict between genetic and phenotypic differentiation: the evolutionary history of a ‘lost and rediscovered’ shorebird. PLoS One 6, 1-9 (2011). doi: 10.1371/journal.pone.0026995.

3. X. Wang, et al., Genetic, phenotypic and ecological differentiation suggests incipient speciation in two charadrius plovers along the chinese coast. BMC Evolutionary Biology 19, 1-18 (2019). doi: 10.1186/s12862019-1449-5.

4. X. Wang, et al., Demographic histories and genome-wide patterns of divergence in incipient species of shorebirds. Frontiers in Genetics 10, 1-14 (2019). doi: 10.3389/fgene.2019.00919.

Hidden Biological Defense Mechanisms Of

JONATHAN ZHU `24

Figure 1 A pharaoh cuttlefish shapeshifts between two different structural forms.

Introduction Over the years, scientists have discovered countless adaptations -horns, teeth, exoskeletons, hibernation, and migration, among others -that allow organisms to defend themselves and compete with surrounding organisms. Biological defense mechanisms, or “a set of traits and mechanisms by which prey avoid being detected, recognized, subjugated, or ultimately consumed by their predators,” substantially increase their possibility of survival (1). Well-known mechanisms include camouflage, protective anatomical structures (i.e. scales, spikes, shells), or poison that provide

animals with a plethora of adaptations for predator avoidance in diverse environments. However, there are also more unique mechanisms, such as thanatosis -- the instinct to “play dead” in the face of danger -- and Batesian or Mullerian mimicry -- forms of mimicry in which a harmless species imitates warning signals of a harmful species, or two harmful species mutually benefit by mimicking each other’s signals. Whether through instinctive behaviors or unique physical traits, these animals have another chance—a reintroduction—to reproductive success and survival.

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Prey has comprised the subordinate section of a biological hierarchy that has existed for millenia. As a result, animal defense mechanisms serve crucial roles in both survivability and ecological stability. The ecology of fear is the first and foremost conceptual framework that keeps prey from becoming food. Fear indicates to animals that they are in danger or are vulnerable, thereby protecting them from being killed and increasing the probability that their genes will be passed onto the next generation (i.e., survivability) (2). Without this sense of fear, animals would not have any instinctual motive to evade or fight against predators towards safety. They would suffer the same fate as the more “feeble” animals throughout history—the flightless Dodo bird, the partially blind Baiji white dolphin, or the slow-moving Steller’s sea cow that have long gone extinct. Although a pertinent and fundamental aspect of biology, defensive mechanisms also help to ensure the survivability and reproduction of animal species over time.

and danger in order to escape or fight against predators, whereas physical adaptations are genetic traits that provide an extra opportunity for protection or evasion. As a helpful addition to organisms’ shapeshifting abilities, a combination of both defensive behavior and unique physical adaptations gives prey animals the greatest opportunity to survive and reproduce in their environment. Various marine animals may use their ability to blend in with their surroundings, mimic stronger and more dangerous animals, access harder-to-reach areas for food, and wedge themselves into small places for hiding. In some cases, their ability to shapeshift may be their only opportunity to evade their predators and avoid an untimely death. Their abilities can be used in dramatically different ways depending on what environment they live in, who their main predators are, and what their main food sources are.

Figure 2 A hagfish is unburrowing itself from the seafloor substrate.

Through long-term adaptation and evolution, prey use visual, chemical, auditory, and tactile cues to detect, avoid, and fight against known predators (3). Through the process of natural selection, these anti-predator traits, which promote the greatest chance of reproductive success, become increasingly prevalent within successive generations. Stability and balance in predator-prey relationships are therefore achieved: food chains and food webs are preserved, populations of predators are naturally regulated and controlled, and biodiversity and community ecology are ensured.

Overview of Shapeshifting While most people are familiar with the concepts of camouflage or mimicry, there is one animal defense mechanism that stands out in particular: shapeshifting. As illusory as it sounds, shapeshifting plays a vital role in the flexible structural adaptation of marine animals. According to a scientific study conducted by senior scientist Roger Hanlon in conjunction with researchers at University of Sydney and the University of Queensland, this structural component allows organisms such as cuttlefish to obscure their outline and profile through their evolved strategy of “skin sculpture” (4). This mechanism confuses predators, many of whom primarily identify the traditional shapes of their prey when hunting for food in murkier or deeper waters. Shapeshifting can be used as both an offensive and a defensive tactic: defensive behavior allows prey to instinctively show aggression

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The Niches of Shapeshifting Animals Shapeshifting animals, like other marine animals in their local environments, use their special adaptations to provide the best ecological advantage for themselves based on their unique surroundings. According to a research study conducted by Dr. Sarah Boggett from the University of Guelph, hagfish (eel-shaped, slime-producing, eyeless marine fish that do not have a vertebral column) use their loosely attached, flaccid skin to slip away their innards (i.e. intestines and internal organs) when punctured by a predator, thereby ensuring their survival (5). Predators are thus distracted by the hagfish’s skin, allowing the hagfish to stealthily escape away with its vital organs. This specific adaptation shows how shapeshifting defense mechanisms can be used in a multitude of different ways to protect such marine animals from potential harm in the wild. Hagfish also have a unique structural combination of a blood-filled body cavity and a notochord (a ridge of sturdy yet flexible cartilage) that allow them the flexibility to tie themselves into knots (6). With such an exclusive shapeshifting mechanism, they become adept burrowers, using a coiling behavior to avoid predators and hide in hard-to-reach spaces within the substrate and seafloor.

Large predators, such as deep sea dwelling sharks, have a difficult time in capturing these prey, making the hagfish population quite prevalent at the deep seafloor level. Unlike most land animals who do not have the unique ability to shapeshift, hagfish with these evolved flexible structures in their

ities to evade predators, sustain environmental changes, survive in the wildlife, and ensure reproductive success for successive generations to come.

aquatic environments have a huge and substantial advantage for predator diversion, evasion, and survivability.

Another aquatic organism with a set of rare shapeshifting abilities is the sea cucumber, which adjusts its body in peculiar ways to achieve anti-predator behavior. In the specific case of predator evasion, sea cucumbers use collagen (a distinct protein compound in their tissues) to “liquify” their bodies from a solid to liquid form and back again (7). This liquification and re-solidification of their tissues allows them to pour and wedge themselves into extremely tight spaces (i.e. cracks in rocks), preventing potential predator attacks. Pharaoh cuttlefish also exhibit shapeshifting qualities: they use camouflage (i.e. changing colors, patterns, size, shape, and even behavior through mimicry) to elude major predators and avoid potential dangers in open areas (8). These cephalopods can even change their skin texture by altering their chromatophores, permitting themselves to emulate larger, hard-shell crustaceans or poisonous and venomous animals to deter predators from eating them. Having the variance of shapeshifting qualities in changing the cuttlefish’s own size, behavior, and texture shows how advantageous these unique adaptations can be for marine animals’ survival and reproduction. Although what we currently know about shapeshifting animals gives the scientific community a good overall understanding of animal mechanisms, advancements in marine biology research can further our knowledge of the world around us and lead to greater bioengineered technology within our own society.

Lastly, Deepstaria jellyfish, which is currently one of the most mysterious aquatic creatures known to scientific researchers, highlights the vast implications and possibilities of how shapeshifting adaptations can differ among various marine animals in diverse marine ecosystems. This is a mostly unknown creature, with little to no research on its whereabouts, behavior, traits and characteristics, and functions in the deep sea. However, researchers do know that they shapeshift by expanding and contracting their bodies to engulf any nearby prey on the ocean floor (9). This discovery will fuel future research on how Deepstaria jellyfish use their bodies to maneuver and defend against larger predators, since they also do not have tentacles like other jellyfish. Their ability to fully expand and contract must be a possibility as both offensive and defensive focal points for survivability.

With these shapeshifting defensive mechanisms from hagfish, sea cucumbers, pharaoh cuttlefish, and Deepstaria jellyfish, one can truly observe the limitless potential of such unique adaptations for marine organisms’ abil-

Conclusion Overall, as shown by these unique shapeshifting animals and their subsequent evolved traits, having such unique adaptations can provide a substantial advantage over other prey who use more “traditional” animal defense mechanisms in aquatic environments. With these definitive characteristics and traits, there are inherent differences between common animal mechanisms and the unique adaptations of shapeshifting marine life. For one, less human-to-wildlife interaction in the deep sea facilitates these “irregular” and “unique” adaptations because research development is slower than studying on land (10). This is because marine research takes additional time to develop more suitable technology to study the deep sea and marine biology, as humans do not tolerate well underwater in extreme conditions (i.e. extremes in pressure, temperature, salinity).

In general, an ocean environment is relatively unstable and highly diverse, leading to a wide range of subsequent physical and behavioral adaptations that provide environmentally-dependent advantages. With marine ecosystems having considerable differences in salinity, temperatures, pH, oxygen levels, and light filtration, aquatic organisms must evolve over time to fulfill specific ecological niches and ensure their own survival and reproduction. Land animals, while more diverse in the number of existing species, generally lack such unique “shapeshifting” qualities since they are able to run and hide more often. As most shapeshifting aquatic creatures are relatively immobile or slow-moving, evolving such unique traits enhances their chances of survival. In a hidden world of biological superpowers, these hidden defensive mechanisms lead to further implications on what we truly know about marine biology research. Future animal research and exploration should continue to be centered around the discovery of new aquatic life and adaptations, as long as marine research technology improves to become more accessible and feasible for deep sea areas. Therefore, with further research, these hidden defensive tactics can be used for counteracting real-world human issues (i.e. bioengineering cuttlefish’s chromatophores for adaptive camouflage in army uniforms), helping to advance human life and preserving such exclusive aquatic organisms.

References 1. B. Rojas, E. Burdfield-Steel, Predator Defense. Springer 1, 49-67 (2017). doi: https://doi. org/10.1007/978-3-319-47829-6_708-1.

2. R. Adolphs, The Biology of Fear. Current Biology 23, 79-93 (2013). doi:10.1016/j. cub.2012.11.055.

3. R. Rosier, Behavior Under Risk: How Animals Avoid Becoming Dinner. Nature Education, (2011).

4. D. Hansford, Cuttlefish Change Color, Shape-Shift to Elude Predators. National Geographic, (2008).

5. S. Boggett et al., Flaccid Skin Protect Hagfishes from Shark Bites. Journal of The Royal Society 14, 1-6 (2017).

6. C. Barras, The Strange Reason Why Hagfish Tie Themselves into Knots. BBC News, (2016).

7. A. Nelson, 13 Amazing Things Animals Can Do With Their Bodies. TreeHugger, (2018).

8. J. Raab, Underwater creatures inspire shape-shifting, color-changing materials. University of Colorado Boulder News, (2019).

9. B. Specktor, Deep-Sea Explorers Find Rare Shapeshifting Jellyfish with a Prize Inside. Live Science, (2019).

10. J. Carilli, How Do We Know What’s in the Ocean? Nature, (2013).

Images retreived from: 1. https://live.staticflickr.com/3912/14755383238_0d81c8da1f_b.jpg 2. https://live.staticflickr.com/7023/6517706799_1419e7826a_b.jpg 3. https://live.staticflickr.com/7337/9734399523_945a732ed8_b.jpg

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A Climate Change Driven Future and Possible Links to Vector Borne Disease Transmission SHUBH THAKER `24 One of the overlooked possible long-term consequences of the climate crisis has been the expansion and ease of disease spread, particularly vector borne diseases, which currently cause an estimated one-sixth of illnesses suffered globally. Vector borne diseases are caused by viral, bacterial, or parasitic infections that are commonly transmitted through the bite of a vector. A vector is classified as an arthropod whose primary feeding method is blood-sucking, such as ticks, fleas, and, most notably, mosquitos [1-3].

The bulk of vector borne disease epidemics take root in nations and regions located near the tropics, where arthropods thrive in the warmer temperatures. Climate experts hypothesize that anthropogenic climate change could result in more widespread pathogenesis of vector borne diseases and pan-

Figure 1 Malaria parasite connecting to Red blood cell.

demics as the expanding range of wet and warm climates present an ideal environment for increased transmission [1,2]. Current climate models exhibit a correlation between areas of warm climate expansion and the transmission of vector borne diseases, suggesting a strong link between the two phenomena [2,4]. However, the suggestions of a direct causal link between climate change and future increase in vector borne diseases incidence remains a premature conclusion. Rather, a stronger causal role is held by the status of a region’s healthcare/vector control infrastructure in determining an increased presence of vectors, their afflictions, and ultimately, deaths stemming from vector borne diseases.

The spread of vector borne diseases is complex and involves dynamic factors beyond simply vector-suitable environments. These factors include the proclivity of an area to naturally inhibit vector populations, such as through predators, or artificially through vector control infrastructure [2,5]. For example, vector population growth may increase dramatically if vector predator abundance is decreased. In 2013, Leroy Gonsalves of the New South Wales Department of Primary Industries and his colleagues conducted a study wherein the abundances of mosquito populations were correlated with the abundance of bats and their inherent ability to access the prey in the Empire Bay region of New South Wales. Mosquito and bat abundance tracking was undertaken in coastal saltmarsh/swamp forest communities where moisture levels and sub-tropical climate provide an ideal environment for freshwater mosquitos. Populations of the bat V. Vulturnus were tracked within coastal saltmarshes and coastal swamp forests through the usage of radio-tracking during two different periods: February 2010 and March 2010. In February 2010, V. Vultarnus preferentially habituated salt marshes, but in March 2010, that preferred habitat shifted to significantly higher coastal swamp forest and open water environment usage. In this time frame, mosquito abundances also shifted, with significantly higher abundances of A. Vigilax present in salt marshes compared to abundances in coastal swamp forests in February 2010, with slight differences during March 2010. The shifts of mosquito populations prompt the shifts of V.Vulturnus, suggesting that the predator keeps vector abundance in control within an area if the prey is accessible [5]. These trends in habitat usage demonstrate that vector population growth may increase dramatically if vector predator abundance is decreased by habitat disturbance through human activities such as foresting and construction. Aquatic predators within regions where mosquitos and other vectors spawn their eggs in or near water, such as tadpoles, fishes, and water insects are also considered to be effective inhibitors of vector population growth [6]. Gonsalves’ findings suggest that if a vector predator population is reduced in an area, there may be an increase in the vector borne disease incidence and transmission.

Increases in incidence and transmission through this scenario are loosely related to climate change, but this example presents a case of more direct influences on vector populations.

Human made vector control infrastructure and methods have been attributed to the decreases of vector borne disease cases worldwide throughout the past century in an era with unprecedented temperature rises. Advanced countries with more economic power coupled with robust health systems and vector control infrastructure have proven to be effective in controlling vector borne disease outbreaks when compared to countries with less economic prowess and weaker public infrastructures. For example, the United States eradicated malaria in the 1940s through heavy vector control measures such as more than 4,650,000 insecticide applications to homes and fields in the southern United States where malaria spread was most common [2,7]. Increased investment into vector control infrastructure around the world, particularly in Africa where malaria was most deadly, has led to the dramatic decrease of malaria in certain areas. Combining studies that examined the effect of popular vector control methods on the entomological inoculation rate (EIR) of malaria in Tanzania and the Solo-

Figure 2 A set of mosquito nets.

mon Islands, Ayesha Shaukat and colleagues of the Fogarty International Center in NIH found that popular vector control methods, such as insecticide-treated nets (ITNs), indoor residual spray (IRS) and source reduction (SR), play a major role in limiting EIR of malaria. Eight vector control intervention studies were conducted to compare the effect of different vector control methods on the EIR of malaria through comparison of a treatment and a separate control group. Four studies observed the effect of ITN, one study examined the effect of IRS, one study observed effect of SR, and two studies studied ITN and IRS on separate intervention groups. Within the second year of the Tanzania study, ITN and IRS resulted in 90% and 93% reduction of EIR compared to their control groups. Compared to the study completed on the Solomon Islands, there was a 94% reduction of EIR due to ITN implementation and a 56% reduction of EIR due to IRS implementation. Vector control significantly inhibits the incidence and transmission of malaria and this trend extends to other vector borne diseases [8]. However, to implement such vector control methods in a widespread manner can become expensive, which is why the countries most affected by malaria and other vector borne diseases are developing countries in Africa. Yet, as there is more economic development and subsequent improvements to public health systems in poorer countries most affected by vector borne diseases, outcomes are constantly improving [2]. For example, the age-standardized disability-adjusted life year (DALY) rate of malaria has decreased by 39% globally from 2007 to 2017. This trend can be attributed to stronger economic development, globalization of aid, and improvements in public health systems in previously heavily affected countries. Vector control methods have been the key to reducing the incidence and transmission of malaria and other vector borne diseases worldwide in the face of rising temperatures and climate change, thus weakening the causal relation between climate change and supposed increases in vector borne disease transmission.

Another concern of climate change that ties the phenomenon to a hypothesized increase in vector borne disease incidence and transmission

is the increase in extreme precipitation events around the world that, in conjunction with warmer temperatures, allow for heightened breeding of mosquitoes and other vectors. Evidence shows that anthropogenic climate change has returned a heightened amount of frequent and intense heavy precipitation events worldwide, which results in the likely damaging of infrastructure and events of still water formation, providing an ideal ground for reproduction [1-2, 4, 9]. Even after heavy rainfall events, healthcare infrastructure and implementation of vector control methods still have a greater effect on the incidence as compared to weather related consequences of climate change. This was the case in the aftermath of Hurricane Harvey in Texas, United States. Gerardo Chowell and colleagues of Georgia State University developed a model which included the influences of vector-borne disease transmissibility, human displacement patterns resulting from storms, the mosquito carrying capacity in the context of heavy rainfall, and the proximity of heavy rainfall events to the typical transmission season. The researchers highlight the model’s ability to incorporate the population displacement that would result after a storm, which is key because it is more likely that vector control methods are not maintained, such as dumping still water, when populations are displaced. Notably, vector borne disease transmission did increase when heavy rainfall events were close to the beginning of the transmission season; but the risks of increased transmission decreased as the season moved along, suggesting that timing is key for an outbreak to be sustained. The model found in the parametrization with Hurricane Harvey (which occurred late in the transmission season) that the storm and its aftermath did not create an environment that could sustain outbreaks by regarding the abundance of transmissions post-event.

In this case, the heavy rainfall event did not significantly create Zika outbreaks or increase transmissions [9]. The lack of outbreaks can likely be explained by the presence of a strong vector control infrastructure and hospital system present in a first world country like the United States. These two systems, which are generally reflective of a country’s economic power, helped to deter sustained outbreaks, thereby further weakening the causal

Figure 3 A mosquito bite.

However, a range of climate scientists do show concern over a future with increased transmission of vector borne diseases related to climate change. Climatic models predict that there will be an increased range of suitable climates ideal for vectors, which could stress regions which were previously not affected by vector borne diseases. Nils Tjaden and colleagues of the University of Bayreuth modeled projections that depicted an expansion of suitable environments for mosquitoes carrying Chikungunya across northern and southern Italy, southwest France, northeast Spain, northern Australia, Florida, and regions of sub-saharan Africa, which is significant considering these areas have not suffered from outbreaks before (Figures 3-7). However, the correlative modelling approach under the context of RCP 4.5 and RCP 8.5 climate change models (which demonstrate the growth of temperatures from 2006-2100, where RCP 8.5 represents a worst case scenario compared to RCP 4.5) is limited by the lack of accounting for socioeconomic development and other factors that may drive or limit disease transmission [4]. Though this model does provide a comprehensive projection of Chikungunya spread range expansion throughout the world, the lack of incorporation of the aforementioned factors does weaken the usage of this model as evidence that climate change is the primary driver of increased transmission of vector borne diseases. However, models such as this one, which explain that climate change does impact disease spread, help to demonstrate that climate change may play a synergistic role in disease spread, rather than directly causing it.

In a climate change driven future, there may be a greater range of vector borne disease spread and transmission. Though rates of transmissions primarily rely on the area’s strength of healthcare and vector control, countries and regions that are still suffering from a lack of robust healthcare and vector control systems in general can experience future vector borne disease epidemics. These subsequent epidemics would become a devastating consequence of climate change, therefore there is a great need to curb the production of emissions that contribute to changing climates. Considering the concerns regarding climate change-driven warming temperatures, there is great need for an expansion of vector control systems, which have been

critical in dramatically reducing cases of diseases such as malaria and Zika.

It is imperative that vector control and eradication programs in conjunction with governments and the private sector increase efforts into developing lasting and widespread vector control infrastructure to optimize protection against a potential rise of vector borne diseases. The WHO currently classifies two widely applicable vector control methods: insecticide-treated nets and indoor residual spraying. The WHO considers widespread usage of insecticide-treated nets and biannual spraying of indoor residual spraying as the largest factors in causing drops in the transmission and incidence of malaria in the 21st century [10]. Most importantly, further research and investment is required for the expanded usage of vector control methods, research and development for vector control innovation, and improvement to hospital infrastructure in at-risk areas to ensure that the possible synergistic effect climate change plays on the increases of vector borne disease transmissions and incidence is controlled.

References 1. D. Campbell-Lendrum, et al., Climate change and vector-borne diseases: what are the implications for public health research and policy?. Philosophical transactions of the Royal Society of London, Biological sciences 370, 1665 (2015). doi: 10.1098/rstb/2013.0552.

2. J. Rockov and R. Dubrow, Climate change: an enduring challenge for vector-borne disease prevention and control. Nature Immunology 21, 479-483 (2020). doi: 10.1038/s41590-02-0648-y.

3. Fact sheet about malaria. World Health Organization, (2020).

4. N. Tjaden, et al., Modelling the effects of global climate change on chikungunya transmission in the 21st century. Scientific Reports 7, (2017). doi: 10.1038/s41598-017-03566-3.

5. L. Gonsalves, et al., Foraging ranges of insectivorous bats shift relative to changes in mosquito abundance. PLos ONE 8, (2013). doi: 10.1371/journal.pone.0064081.

6. Global vector control response 2017-2030. World Health Organization, (2017).

7. CDC - malaria - about malaria - history - elimination of malaria in the united states, 1947-1951.

Centers for Disease Control and Prevention, (2020).

8. A. Saukrat, et al., Using the entomological inoculation rate to assess the impact of vector control on malaria parasite transmission and elimination. Malaria Journal 9, (2010). doi: 10.1186/14752875-9-122.

9. G. Chowell, et al., Assessing the potential impact of vector-borne disease transmission following heavy rainfall events: a mathematical framework. Philosophical transactions of the Royal Society of London 374, 1775 (2019). doi: 10.1098/rstb.2018.0272.

10. Core vector control methods. World Health Organization, (2020).

Images retrieved from: 1. https://commons.wikimedia.org/wiki/File:Malaria_Parasite_Connecting_to_Human _Red_Blood_Cell_(34034143483).jpg 2. https://www.flickr.com/photos/philliecasablanca/2051885445 3. https://pixabay.com/photos/mosquito-insect-mosquito-bite-49141/

Evolutionary Function of Sleep Explored in Study of Mammalian Sleep and Waste Clearance in Drosophila FIONA LAM `24 Introduction A third of our lives is spent unconscious, but for good reason. One of the core behaviors that contribute to the survival of mammals is sleep.

Without sufficient sleep, humans and other animals alike suffer detrimental effects to their health and wellbeing; these include poor judgment, weakened memory, slower reaction time, unhealthy weight loss, irregular body temperature, and low maintenance of homeostasis (1). A key to understanding the role of sleep in humans is the study of sleep in Drosophila, a genus of flies in which many pathophysiological mechanisms are analogous to those underlying human disease.

An Overview of Mammalian Sleep The general signs of sleep are periods of inactivity of the body and overall unresponsiveness to the external world. These, along with a speedy transition to a state of wakefulness and specific changes in the electroencephalogram (EEG), constitute mammalian sleep (6). Inactivity, however, does not signify complete immobility. The postures in which mammals sleep vary across the board: some stand, some swim, and some sleep with their eyes semi-open. There are numerous variables that affect how certain mammals prepare for sleep, such as choice of sleeping location and ritualistic rou-

Figure 1 A close-up of the Drosophila melanogaster. This species of fly is most commonly studied when it comes to understanding the evolutionary underpinnings of sleep disorders in humans.

tines; as a result, mammalian sleep is viewed as a natural behavior performed to maintain the healthy function of an organism.

Mammalian sleep is polyphasic, having multiple phases that oscillate between sleep and wake states according to the individual need of an organism. No generalization can be made about the degree to which mammals respond to external stimuli during sleep; this varies greatly across species and circumstance. EEG patterns detected in mammal sleep states indicate an increase in wave amplitude and appear to suggest slow cognitive activity and a decrease in muscle movement. Spindling and the presence of slow waves are indications of quiet (or non-rapid eye movement) sleep, though spindling activity may vary by frequency and amplitude and waves differ by frequency. Non-rapid eye movement (NREM) sleep is divided into two categories: “light” and “deep” sleep. Categorization is dependent on delta wave activity. The occurrence of delta rhythms is typically associated with deep sleep stages, although delta waves have been detected in completely conscious rodent models as well as in human research subjects (6).

In addition to dormancy and an absence of response to external stimuli, a key part of mammalian sleep is homeostatic self-regulation, or the act of balancing out time asleep with time awake. On a basic level, mammalian sleep follows a cyclical organization in which species fall in and out of NREM and REM sleep, creating a NREM-REM sleep cycle (6). Sleep and wake cycles go hand in hand with circadian rhythm, or the biological clock that operates along a 24-hour cycle and fluctuates based on several natural factors. Light exposure -- including the type and intensity of light and the length and time of exposure -- has the biggest influence on human alertness and drowsiness during the day and the night (8). Other factors that impact circadian rhythm include physical activity, temperature, and environmental signals. The suprachiasmatic nucleus (SCN) is the central structure that regulates most circadian rhythms in the human body. Composed of two nuclei, each containing 10,000 neurons, the SCN uses light to guide the sleepwake cycle and releases the hormone melatonin, which promotes sleep, when little to no light is detected. The SCN also integrates and adapts to the impact of external factors on circadian rhythm: for example, melatonin production is increased during winter months, when nights are longer (7).

Disruption of the SCN clock and circadian rhythm can be generally traced to the presence of mood disorders and sleep disorders. Individuals with bipolar or major depressive disorders, for example, often experience “weaker rhythms of clock gene expression,” resulting in disturbances in hormone regulation and therefore appetite, sleep, and stress levels (8).

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Figure 2 Synaptic vesicles release neu-

rotransmitters that bind to the receptors on the postsynaptic membrane. Low levels of the neurotransmitter dopamine are associated with suppressed REM sleep and a slight suppression of slow-wave sleep (SWS).

Two common circadian rhythm sleep disorders are advanced sleep phase disorders (ASP) and delayed sleep phase disorders (DSP). In the former, sleep is initiated at a normal time, but individuals wake up several hours earlier than average; in the latter, individuals sleep several hours past midnight and wake up in the late morning or in the afternoon (7). It is worth noting that homeostatic control and circadian control cooperate to maintain the physiology of organisms: homeostatic control handles sleep intensity, while circadian control handles timing of sleep.

An Overview of Drosophila Sleep On a fundamental level, Drosophila sleep is very similar to mammalian sleep. It is characterized by periods of inactivity, a lessened alertness to one’s surroundings, and rebound sleep as a result of insufficient sleep (3).

Perhaps the most defining feature of fly sleep, however, is the absence of response to the external world (3). Flies are considered to be in a sleep state when they undergo a period of inactivity that lasts longer than five minutes.

And whereas humans sleep in stages, cycling through episodes of REM and non-REM sleep, sleep in flies varies in both intensity and timing (2). New scientific research has revealed a new deep sleep stage called “Proboscis Extension Sleep” in Drosophila -- a pattern of repetitive proboscis extensions and retractions that occur during fly sleep. This sleep stage appears to facilitate waste clearance in the Drosophila brain, leading scientists to conclude that sleep may have served a similar function in the common ancestor of flies and humans (3).

The Study of Waste Clearance in Drosophila Drosophila melanogaster is one of the few species that has a proboscis -- a tube-like snout through which fruit flies retrieve their food. The proboscis varies in length depending on the type of insect and the type of food they typically ingest (3). Proboscis extensions (PEs) are proboscis movements followed by a retraction; these are presumably different from the proboscis extension reflex (PER), a behavior in which the proboscis is extended as a reaction to the stimulation of the fly’s taste receptors. Furthermore, there are no known particular triggers for PEs; they’re characterized by an absence of leg and wing movement and either take place as single events or continuous bursts of up to 15 or more PEs with approximately three seconds in between each (3).

In addition to immobility, Drosophila sleep is characterized by reduced brain activity and increased arousal thresholds. Arousal thresholds

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in the context of human sleep speak to wakefulness; higher arousal thresholds indicate that someone is harder to wake, and lower arousal thresholds indicate that someone is easier to wake (5). In Drosophila, however, things aren’t as clear-cut. The mere action of waking from sleep is a sign of arousal or general responsiveness to the environment. Arousal can come in many forms in Drosophila depending on the behavioral standard being used to measure arousal (5). Furthermore, multiple studies have solidified the link between the amount of dopamine (DA) in flies and their sleep and wake cycles, where more DA corresponds with less sleep and vice versa (5).

For example, a comparative study from 2006 found that specific behaviors and experiences like psychosis and sleep disturbances in people with Parkinson’s disease, a disorder characterized by a damaged central nervous system, were correlated with levels of dopamine. Researchers who facilitated this same study explored behaviors in mice by manipulating levels of dopamine in the mice during their sleep and wake states using a two-dimensional state map that recorded brain wave activity (10). They concluded that dopamine-depleted mice contained brain activity that mirrored that of slow-wave sleep (SWS), a form of sleep characterized by low brain and low muscle activity. Since the defining aspects of REM sleep are the complete opposite of these listed, low levels of dopamine were also associated with the suppression of REM sleep and only a slight suppression of normal SWS. Since the role of dopamine in the body directly affects neural processes via the sending of messages between nerve cells to produce increased productivity and positive emotions, it’s no surprise that neurological disorders like schizophrenia and Parkinson’s disease share a common connection to the rise and drop of dopamine levels. In fact, evidence presented in the study suggests that the activation of the D2 dopamine receptor triggers psychosis, intensifying these hallucinogenic experiences in Parkinsonian patients.

Thus, studies centered around the response of both flies and mice to changing dopamine levels give researchers insight into how humans respond to the neurotransmitter with respect to sleep as well (18).

In a study conducted by researchers at Northwestern University, imaging experiments, high-impact trauma (HIT) assays, feeding-based excretion assays, and more tests were performed on groups of fruit flies to learn more about the function of the proboscis and how PEs affect the flies’ ability to execute the process of waste removal, which is crucial to their survival.

Senior author of the study and professor of neuroscience, Dr. Ravi Allada, notes that waste clearance as a whole could be imperative to maintaining stable cognitive function in the brain or for preventing the development of

neurodegenerative disorders (4). He also comments on the relevance of the study of Drosophila in particular to the ongoing mysteries surrounding human sleep, as the neurons that take part in flies’ sleep-wake cycles are similar to those of humans. Allada and his team pulled information from their video recordings of tethered flies when they’ve been placed under different conditions to track the response to varying stimuli that could ultimately impact fly sleep.

As is the case for human sleep, circadian and homeostatic control are major factors of fly sleep. It is suggested that Drosophila sleep follows a biological clock, with PEs per hour reaching their minimum at CT0 -- when diurnal organisms begin their activity phase -- and their maximum at CT12, when nocturnal organisms begin their activity phase (3). We know from the same study conducted by Northwestern University that the PEs are under homeostatic control because the number of PEs per hour increased during the first 2 hours of rebound sleep and the latency to the first PE occurrence was reduced in the sleep deprived group of flies. Since sleep latency measures the amount of time required for an organism to transition from an awake to a sleep state, it follows that sleep latency is reduced in the sleep deprived group. The link between PE patterns and the management of circadian and homeostatic control in Drosophila confirms the functional role that PEs play in fly sleep.

To test whether immobilization of the proboscis would impact the flies’ ability to feed, researchers from the same study applied a light glue to the base and middle sections of the proboscis, halting PEs from taking place. After being given three days to recover, the flies were fed food colored with a harmless dye that, if properly excreted from their systems, would demonstrate the working function of their feeding and excretory procedures. Scientists concluded that this didn’t affect overall food consumption nor excretion of the foods ingested by the flies (3). Decreasing PE does, however, increase the mortality rate of flies that previously suffered injuries (3). This serves as a sign that PEs contribute to the physiological responses of flies, possibly playing a role in reducing stress in the insects. Models created from the data gathered show that “glue-immobilizing the proboscis reduces the rate at which injected dye is cleared” (3). Though immobilizing the PE slowed the process of excretion during the first couple of hours after injection, the amount of dye excreted in 24 hours by proboscis-immobilized flies is the same as that by flies that undergo the placebo effect, indicating that all injected dye eventually leaves the system (3). More research emerging on proboscis extension sleep and its connection to waste clearance in Drosophila may strengthen the possibility of there being evidence of evolutionary ties between the main functions of sleep in flies and humans.

that a similar process of waste clearance is undergone as well (9). This fluid can be found in spaces gathered around the perimeters of blood vessels.

Cerebrospinal fluid gains access to neurons and other brain cells through glia, which are cells that maintain homeostasis in the brain by taking part in the process of synaptic pruning. Once it makes its way past glia, cerebrospinal fluid collects debris and clears it by dropping it off at lymphatic ducts. Their work with mouse models also indicated that sleep is directly correlated with an increase in glymphatic flow, enabling increased waste clearance from the brain. A 2017 study conducted by Dr. Barbara Bendlin and her co-researchers at the University of Wisconsin-Madison generated a similar conclusion: insomnia was connected to a significant increase in the buildup of insoluble clumps of biological markers that are thought to contribute to the development of Alzheimer’s disease (9). While additional studies are currently underway to determine whether a causal relationship exists between these two variables, there is clearly a correlation between sleep and waste clearance in humans.

Waste Clearance: Mechanisms and Functions in Mammals As more research regarding the waste clearance in Drosophila surfaces, the waste clearing processes that human brains execute continue to be evaluated. The lymphatic system of the human body is a large network that regulates fluid levels, fights off foreign invaders in the body, and removes cellular waste and abnormal cells from the lymphatic fluid (lymph), a residue-like substance left over from cells and tissues. Lymph makes its way into each organ, picks up debris, and travels into the blood vessels. From there, the debris left behind enters the blood and is emptied out by the kidney and liver via the excretory system (9). Since the lymphatic system alone is so busy, it is no surprise that the human brain has developed its own method of clearing waste.

Dr. Maiken Nedergaard of the Departments of Neuroscience and Neurology at the University of Rochester was the first to introduce the term “glymphatic system,” a combination of “glia” and “lymphatic system,” in the description of the human brain’s approach to managing waste disposal. Dr. Nedergaard and her team found that cerebrospinal fluid in the brain acts similarly to lymph in that it drains into the same lymphatic ducts, implying

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American Association for the Advancement of Science, (2021).

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5. B. Van Swinderen and R. Andretic, Dopamine in Drosophila: setting arousal thresholds in a miniature brain. The Royal Society, (2011).

6. H. Zepelin, J. M. Siegel, and I. Tobler, Mammalian sleep. University of Los Angeles, California, (2005).

7. M. A. Ma and E. H. Morrison, Neuroanatomy, nucleus suprachiasmatic. NCBI, (2020).

8. D. Landgraf, et al., Genetic disruption of circadian rhythms in the suprachiasmatic nucleus causes helplessness, behavioral despair, and anxiety-like behavior in mice. NCBI, (2016).

9. B. Andreone, Clearing out the junk: healthy lifestyle choices boost brain waste disposal. Harvard University, (2018).

10. K. Dzirasa, et al., Dopaminergic control of sleep-wake states. Society for Neuroscience, (2006).

Conclusion Both mammalian sleep and Drosophila sleep function with respect to each species’ survival needs and lifestyles. Much of the research that has been uncovered about human tendencies during stages of sleep can be traced back to studies done on fruit flies, which have sleep and wake cycles quite similar to ours. In solidifying a relationship between a newly discovered proboscis extension sleep in Drosophila and a system of waste disposal in these flies, we learn more about the connection between human sleep and waste clearance that occurs in human brains. Sleep, therefore, has been deemed to possess restorative functions, that, as species evolve, continue to prove that mammals and Drosophila have more in common than we think. Ideas for potential future research range from whether sleep can be replaced with brain chemicals or drugs to how geographical and cultural factors define and affect the outcomes of adequate sleep in different places of the world across multiple species. Keeping in mind that sleep deprivation has become a global health struggle, are there natural sleep alternatives that perhaps humans and other primates could turn to for better sleep? How does waste clearance in the brain impact other cognitive behaviors and functions, and how important is the rate of waste clearance when it comes to getting quality sleep? Perhaps after digging deeper into these questions, the origins of mammalian and fly sleep can be used to further explore characteristics of and treatments for sleep disorders in humans.

References

Images retrieved from: 1. https://live.staticflickr.com/4605/25799193138_372b24bf90_b.jpg 2. https://upload.wikimedia.org/wikipedia/commons/0/01/Neurotransmitters.jpg

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Ancient Immunity:

The Role of an Ancestral Gene in the Fight Against COVID-19

NATALIE DZIKOWSKI `22

Viral infections have posed a challenge to human survival since the Homo sapiens species first evolved. In fact, researchers hypothesize that viruses have been around for billions of years, long before their future human hosts (1). Long before modern medical practices became widespread, the molecules and cells of the human immune system rose to the challenge of fighting viral infections. One of those molecules was OAS1, an enzyme involved in a pathway that inhibits viral replication (2).

There is support for the hypothesis that certain variants of this enzyme had been introduced into the Homo sapiens species through mating events with Neanderthals thousands of years ago (3). It has been conserved in humans and primates this whole time, humbly executing its vital role in immunity (4). OAS1 has been investigated for its interactions with many different RNA viruses. Recently, it has made a comeback in scientific literature regarding its role in the COVID-19 immune response.

OAS1 is an enzyme, or a protein that helps catalyze chemical reactions, and it is encoded by a gene on chromosome 12 (4).

This enzyme has not acted alone; it actually belongs to a whole family of 2’-5’ oligoadenylate synthetases, or OASs. OASs are able to recognize when RNA viruses, such as coronaviruses, trespass into a cell.

These viruses are categorized by the type of genetic material they carry, called ribonucleic acid or RNA. It is this genetic molecule, specifically double-stranded RNA, that OAS1 can recognize and bind to when a virus en-

ters a host cell. Once OAS1 is alerted to this threat, it communicates with its sidekick: another enzyme called RNase L. OAS1 quickly catalyzes a reaction that generates 2’-5’ oligoadenylate, a long molecule made up of modified adenosine nucleotides (2). This molecule, in turn, binds to RNase L, inducing a change in its overall structure. This shape change enables it to cut up the double-stranded RNA into small pieces, rendering it unusable by the virus. Ultimately, RNase L prevents the virus from replicating within its host and attacking more host cells (2). In essence, RNase L is the fighter, while OAS1 arms it with what it needs to fight. Together, they have executed an extremely important, yet behind-the-scenes molecular mechanism in the body’s response to viral infections.

In fact, this immunoprotective response may have benefitted our ancestors 100,000 years ago, when Homo neanderthalensis — the Neanderthal — and Homo sapiens coexisted (3). Neanderthals and Homo sapiens are classified as different species, and their genomes have slightly different versions of the same genes, called variants. Variants in genes that code for proteins, like OAS1, can actually result in major changes in structure and function of that protein. Depending on the significance of the protein’s function, this may ultimately lead to variations in broader physiological responses.

When Homo neanderthalensis and Homo sapiens first diverged into different species, the majority of Neanderthal genetic

Just as p46 may have helped our ancestors hundreds of thousands of years ago, it may be aiding certain populations in fighting COVID-19 infection today.

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variants had been quickly removed from the Homo sapiens genome, and the two species only had a small proportion of variants in common. In fact, the proportion of variants that were still shared by the human and Neanderthal genomes further dropped from 10% to about 3% (3). However, about 100,000 years ago, two major interbreeding events occurred between the species, reintroducing some Neanderthal genetic variants into human DNA. Increased proliferation of RNA viruses may have actually been a driving force for these mating events. Comparative DNA sequencing studies have identified that Neanderthal gene variants on chromosome 12 coding for virus-fighting enzymes were among the few variants that underwent positive selection, remaining in the modern human genome (3). Among these was a Neanderthal version of the gene coding for the OAS1 enzyme, called the p46 variant. It was found to have undergone prominent positive selection, particularly in Eurasian populations (6). Researchers from the University of Montreal studied specific sites of genetic variation, called single nucleotide polymorphisms (SNPs), at

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the p46 gene locus. The results of their DNA sequencing studies showed that the SNPs associated with Neanderthal p46 were expressed at frequencies 20% greater than expected in modern, Eurasian human populations (6).

Insight into the function of the p46 variant of the OAS1 enzyme compared to other forms may offer more clarity on why this variant has remained in the Homo sapiens genome. This version of OAS1 has higher levels of enzymatic activity due to its ability to synthesize more complex and higher order versions of the 2’-5’ oligoadenylate molecule that activates RNase L (10). Homo sapiens who inherited this form of the enzyme from Neanderthals could have gained a survival advantage when faced with the threat of RNA viruses (6). The process by which reintroduction of this gene variant provided a survival benefit to humans is known as adaptive introgression (6).

Just as p46 may have helped our ancestors hundreds of thousands of years ago, it may be aiding certain populations in fighting COVID-19 infection today. A recently published Mendelian randomization study conducted by researchers at McGill University tested whether the level of the p46 variant correlated with COVID-19 outcomes. They analyzed the genome data and circulating enzyme levels of 14,134 COVID-19 patients of European ancestry (7). Their results showed that higher circulating levels of the p46 variant during a non-infectious state were linked to a protective effect against severe COVID-19 outcomes such as death, hospitalization, and the need for mechanical ventilation (7). In fact, each increase in the standard deviation of circulating p46 levels correlated to a 50% reduction in severe COVID-19 outcomes (7). This magnitude of difference shown by the Neanderthal variant has placed OAS1 in the spotlight as a new target for COVID-19 therapies. OAS1 can serve as a valuable biomarker that can be measured to predict outcomes of both viral and autoimmune diseases (2).

COVID-19 is not the only virus whose outcomes are impacted by OAS1 variants. In the past, OAS1 has also been investigated in connection to hepatitis B and West Nile virus. It turns out that carrying other versions of the OAS1 gene, like the p48 and p52 variants, is actually associated with negative outcomes for these particular viruses. These variants encode less strong enzymatic activity, unlike p46 (8). For example, genome analyses showed that the alleles encoding the p48 or p52 form of the OAS1 protein were expressed in higher levels in both symptomatic and asymptomatic carriers of West Nile virus, compared to control groups (8). Other genotype analyses found that the presence of these variants is higher in those who develop the autoimmune disorder Sjögren’s syndrome after infection with hepatitis B virus (9).

To uncover more about the intricacies of OAS1 polymorphisms, researchers have turned to analyzing the DNA of old-world primates. Overall, it was found that many sites of the OAS1 gene have been conserved, even among different species of primates. In 2016, researchers from the

City University of New York found that across 22 different species of oldworld primates, 31 to 32 amino acid sites were conserved, 50% of which are located in the exact spot on OAS1 that is used to bind to viral RNA (4).

Since this spot is critical for OAS1’s recognition of viruses, the presence of these conserved sites may have allowed old-world primates to successfully survive the challenges posed by RNA viruses, while other organisms lacking these conserved sequences did not.

However, the RNA-binding domain of OAS1 still has highly detailed and unique variation. SNPs and sites of high variation have been commonly observed when sequencing the OAS1 RNA-binding domain in primates. The 54th amino acid in the OAS1 enzyme has been identified as its most highly variable site among primates, and it is directly involved in the enzyme’s recognition of viral RNA (5). How exactly this variation impacts the function of OAS1 is not currently understood in depth, but connecting genome-wide association studies, protein sequencing, and clinical studies can help us understand what aspect of the OAS1 enzyme structure leads to better or worse disease outcomes in humans.

Genetic analyses of common ancestors and close evolutionary relatives of humans give us more than percentage similarities of DNA and sequences of adaptively introgressed gene variants. They tell stories about the past challenges that human beings faced, and leave us with questions on how to face similar ones today. The COVID-19 pandemic of the 21st century has been one of the most unpredictable threats to human health, revealing new differences in immune responses and severity of outcomes in different individuals. Understanding the molecular mechanisms behind human adaptations to RNA viruses can teach us a lot about these differences and help lead us to the development of new therapeutic approaches. Hidden in our ancient, evolutionary history are answers to challenges we currently face.

References 1. W. Diehl, et al., Tracking interspecies transmission and long-term evolution of an ancient retrovirus using the genomes of modern mammals. eLife 5, 1-25 (2016). doi: 10.7554/eLife.12704.

2. U. Choi, et al., Oligoadenylate synthase-like (OASL) proteins: dual functions and associations with diseases. Experimental & Molecular Medicine 47, 1-6 (2015). https://doi.org/10.1038/ emm.2014.110.

3. D. Enard and D. Petrov, Evidence that RNA viruses drove adaptive introgression between Neanderthals and modern humans. Cell 175, 360-371 (2018). https://doi.org/10.1016/j. cell.2018.08.034.

4. I. Fish and S. Boissinot, Functional evolution of the OAS1 viral sensor: insights from old world primates. Infection, Genetics and Evolution: Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases 44, 341-350 (2016). https://doi.org/10.1016/j.meegid.2016.07.005.

5. I. Fish and S. Boissinot, Contrasted patterns of variation and evolutionary convergence at the antiviral OAS1 gene in old world primates. Immunogenetics 67, 487-499, (2015). doi: 10.1007/ s00251-015-0855-0.

6. A. Sams, et al., Adaptively introgressed Neandertal haplotype at the OAS locus functionally impacts innate immune responses in humans. Genome Biol 17, 1-15 (2016). https://doi.org/10.1186/ s13059-016-1098-6.

7. S. Zhou, et al., A Neanderthal OAS1 isoform protects individuals of European ancestry against COVID-19 susceptibility and severity. Nature Medicine 1-24 (2021). https://doi.org/10.1038/ s41591-021-01281-1.

8. J. Lim, et al., Genetic variation in OAS1 is a risk factor for initial infection with West Nile virus in man. PLoS Pathogens 5, 1-12 (2009). doi:10.1371/journal.ppat.1000321.

9. X. Liu, et al., A functional variant in the OAS1 gene is associated with Sjögren’s syndrome complicated with HBV infection. Scientific Reports 7, 1-9 (2017). https://doi.org/10.1038/s41598017-17931-9.

10. H. Di, H. Elbahesh, and M. Brinton, Characteristics of human OAS1 isoform proteins. Viruses 12, 1-16 (2020). doi: 10.3390/v12020152.

Images drawn by Isra Ahmed ‘23

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The Mysteries of How Non-Neural Components of the Brain Play a Role in Memory Formation JASMINE KUMAR `22

There are many mysteries surrounding memory formation and consolidation. However, it is well known in the scientific community that neural components of the brain play a very important role in memory formation. More specifically, neural components such as signal transmitting synapses, neuronal branches called axons that transmit signals, and neuronal dendrites that receive signals work together to form memories (1). Neural components form memories in response to a stimulus that releases neurochemicals or neurotransmitters at the synaptic membrane, which increases the synaptic strength of neurons to communicate the memory trace. If the stimulus is strong enough, gene transcription and protein formation will result in the creation of new synapses to support the formation of a memory (2).

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Figure 1 Outlined above is the sequence by which the non-neural PNNs participate in memory

consolidation, surrounding GABAergic Interneurons to produce inhibitory neurotransmitters that prevent synapse formation.

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Although many studies regarding memory demonstrate how neural components of the brain play a major role in formation, recent studies have demonstrated how non-neural components can also play an essential role.

For instance, perineural nets (PNNs) are non-neural components of the brain that have been found to assist in the formation of memories. PNNs consist of a lattice-like structure of protein and carbohydrate aggregates that surround the cell body and proximal dendrites of subpopulations of neurons in the central nervous system (CNS) that were discovered by Camillo Golgi in the 1800s (1). Tommasso Pizzoruso and James Fawcett first discovered that PNNs impacted brain plasticity two decades ago, when Fawcett discovered a bacterial enzyme, chondroitinase ABC (chABC), that destroyed PNNs, and combined his findings with Pizzoruso’s. Thus, a sudden revival within the scientific community took place in studying non-neural components such as the PNN after many centuries of disregarding them (3).

MEMORY Studies have demonstrated that PNNs can form memories by stunting neural plasticity. Plasticity is the ability of CON neurons to reorganize or reassemble synaptic L I D AT connectivity in response to experiences (4).

The heightened plasticity period, or critical period (CP), refers to periods in one’s lifetime in which both nature and nurture had molded experiences for an individual that increased their cognitive function, and especially occur during windows of early life (5). Neurons often reach this critical period during childhood and adolescence because the brain tends to have more plasticity and thus is more sensitive to gaining cognitive function and learning new skills as a result of life experiences (5). Janet Werker and Takao Hensch of the Canadian Institute for Advanced Research demonstrated that when certain pathways in the brain are at this CP, the perineuronal net acts as a “physical brake” to prevent synaptic growth (1). One of the many puzzling findings regarding PNNs is that they can form long term memories by preventing further synaptic growth, whereas

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The influence of PCC absence on remote fear memory recall is seen when chABC is injected during the conditioned place preference (CPP) procedure.

GABAergic interneurons in combination with PNN formation around them towards the end of the CP results in the blockage of further synaptic growth.

Research conducted by Megan Slaker and colleagues demonstrates that the function of PNNs in memory formation may be utilized in the development of novel therapeutic remedies for treating drug addiction.

Slacker and her colleagues used a conditioned place preference (CPP) procedure to create cocaine addiction related CPP memories within rats that allowed them to form a memory of a specific location in which cocaine cravings occur. More specifically, rats underwent a CPP procedure within different plexiglass compartments, in which there was one group conditioned to prefer a cocaine paired compartment and another group conditioned to prefer a saline paired compartment. After the CPP procedure, the PNNs from their medial prefrontal cortex were removed utilizing chABC. Results demonstrated that the removal of PNNs from the prelimbic region of male adult rats impairs the formation and reconsolidation of the cocaine induced CPP memory (7). These results highlight that research regarding the role of PNNs within memory formation and even reconsolidation can be utilized to develop novel therapeutic remedies for drug addiction in the future.

Memory reconsolidation, however, is not the same as memory formation due to differences in the physiological and biological mechanisms between reconsolidating a memory and forming a memory. In fact, memory consolidation is a part of forming a memory,

Future research on PNNs’ impact on memories remains necessary and has the potential to lead to developments in novel drug addiction therapies, memory restoration therapies for Alzheimer’s and other forms of tauopathy, and more.

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neural components aid in memory formation by promoting further synaptic growth instead. Thus opposite to neural components, PNNs play a role in memory formation by restricting brain plasticity and synaptic growth.

Studies have determined that the physiological basis for PNNs inhibitory effect is related to their formation around a specific class of neurons. PNNs tend to surround a class of neurons, known as GABAergic interneurons, that produce a calcium-binding protein called parvalbumin (PV). The PV+ GABAergic interneuron then releases inhibitory neurotransmitters that prevent other neurons from firing (3). Thus, the physiological explanation regarding how PNNs disrupt plasticity involves PNNs surrounding these PV+ GABAergic interneurons, as the CP closes, resulting in PV’s inhibitory effects through the creation of a lattice like structure that prevents the formation of new synapses (4).

In a study conducted by Elise Thompson at the University of Oslo, PNNs were removed from rats, leading to the inability to recall a remote fear memory (6). The rats were exposed to a conditioned stimulus of a white light, and an unconditioned stimulus of a foot shock, which stimulated the formation of a fear memory. Following four weeks of training to pair the unconditioned and conditioned stimuli, the PNN in the lateral secondary visual cortex (V2L) was degraded using injections of chABC. Results demonstrated that the degradation of the PNN disrupted the recall of the remote unconditioned stimulus, or fear memory. The same experiment was repeated to test recent memory recall, where chABC was injected into V2L one day after training and the animals were allowed to recover for six days before testing again. In this case, results indicated that the degradation of PNN using chABC did not influence the recall of recent fear memory. Thus, the results indicate that PNNs are involved in remote memory recall, but not in recent memory recall, leading researchers to conclude that PNNs play an especially important role in long term memory formation (6).

Oscillatory activity in the brain was measured to determine if a stimulus is firing, resulting in greater brain activity, or if it is inhibited, resulting in smaller activity. Synchronized oscillatory activity is a known physiological correlate of memory retrieval and indicates communication between V2L and basolateral amygdala (BLA). Within Thompson’s study, the firing of PV+ neurons was associated with synchronized oscillation activity between the V2L and BLA regions of the brain. Synchronized oscillation activity indicated an increase in PV+ firing, blockage of synaptic growth, and restriction of plasticity due to the PNN’s forming a memory.

Synchronized oscillatory neural activity between V2L and BLA was collected for both the remote control group and the remote experimental fear memory recall group. Results demonstrated that the control group had synchronized oscillatory activity between V2L and BLA, with a peak at 7Hz, and thus could recall the fear memory remotely.

However, the experimental group that was injected with chABC and tested for recall of remote fear memory could not recall the remote memory since there was no synchronization in oscillatory activity that is associated with a decline in PV+ firing. Lastly, the rats tested for recent memory retrieval also demonstrated synchronized oscillatory activity during the conditioned stimulus presentation (6). Thus, this study supported the physiological explanation that the maturation of PV+

and memory reconsolidation just refers to the reactivation of a consolidated memory. However, this reactivation brought about by reconsolidation can change or even delete the initial memory (8).

Another research study led by Sujeong Yang and his colleagues affiliated with the University of Cambridge demonstrated PNNs’ role in memory formation and took advantage of their role to treat a neurodegenerative disease known as tauopathy in mice. Alzheimer’s disease is the most widespread form of tauopathy that is known (9).

More specifically, tauopathy results from intracellular deposits of the tau protein. Under pathological conditions, the tau protein can undergo post translational modifications, like being phosphorylated or acetylated, which can damage neurons (10). A transgenic mouse model was utilized to induce tauopathy within these mice by introducing mutant P301S tau in their neurons. Additionally, another transgenic mouse model was created by introducing an adeno-associated virus that expressed P301S tau in the perirhinal cortex, a region associated with object recognition (OR) memory.

There was a 15% loss of neurons in the first mouse model compared to its control group, and a 26% loss of neurons in the second mouse model compared to its control group. Although this neuronal loss is considered to be quite low in both models, it was still statistically significant compared to their controls. Despite this low neuronal loss observed in both mouse models, there was a major loss of OR memory observed in both models. A week later, chABC was used to reactivate plasticity by reducing the PNNs in the perirhinal cortex, and this injection of chABC restored OR memory in both models (9). As demonstrated in Slacker and Thompson’s studies, a loss in PNNs resulted in impairment in memory formation through the inability of memory recall because PNNs were no longer there to stunt synaptic transmission and plasticity, which promotes memory formation.

However, in Yang’s study a loss in PNNs, or the reactivation of plasticity and restoration of synaptic growth and transmission, had the opposite effect on memory formation where a loss in PNNs was associated with OR memory recall. Yang hypothesized that this loss of PNNs allowed for synaptic growth and plasticity to be restored and that may have improved memory formation (9).

These contradicting findings in Yang’s, Slaker’s, and Thompson’s studies indicate that there are many mysteries surrounding how exactly PNNs impact memory formation. It is important to consider that Slaker and Thompson focused on psychological memory, whereas Yang focused on memory related to neurodegenerative diseases, which could possibly influence these contradicting findings. Future studies comparing the effects of PNN removal in various regions of the brain on memory formation could help further elucidate the explanation for these contradictions.

Overall, future research on PNNs’ impact on memories remains necessary and has the potential to lead to developments in novel drug addiction therapies, memory restoration therapies for Alzheimer’s, and other forms of tauopathy.

References 1. S.Ackerman, The nets around the neurons. American Scientist, (2021).

2. G. Miller, How our brains make memories. https://www.smithsonianmag.com/science-nature/ how-our-brains-make-memories-14466850/, (2010).

3. H.Shen, Core concept: perineuronal nets gain prominence for their role in learning, memory, and plasticity. PNAS 115, 9813-9815 (2018). doi:10.1073/pnas.1815273115.

4. J.Duncan, et al., The potential of memory enhancement through modulation of perineuronal nets. British Pharmacological Society 176, 3611-3621 (2019). doi: 10.1111/bph.14672.

5. R. Reh, et al., Critical period regulation across multiple timescales. PNAS 117, 1-6 (2020). doi: 10.1073/pnas.1820836117.

6. E.Thompson, et al., Removal of perineuronal nets disrupts recall of a remote fear memory. PNAS 115, 607-612 (2018). doi:10.1073/pnas.1713530115.

7. M. Slaker, et al., Removal of perineuronal nets in the medial prefrontal cortex impairs the acquisition and reconsolidation of a cocaine-induced conditioned place preference memory. The Journal of Neuroscience 35, 4190-4202 (2015). doi: https://dx.doi.org/10.1523%2FJNEUROSCI.3592-14.2015.

8. L. Nadel, et al., Memory formation, consolidation, and transformation. Neuroscience and Biobehavioral Reviews 36, 1640-1645 (2012). doi: 10.1016/j.neubiorev.2012.03.001.

9. S. Yang, et al., Perineuronal net digestion with chondroitinase restores memory in mice with tau pathology. Experimental Neurology 265, 48-58 (2015). doi: 10.1016/j.expneurol.2014.11.013.

10. G. Hoglinger, G. Respondek, and G. Kovacs, New classification of tauopathies . Revue Neurologique 174, 664-668 (2018). doi: 10.1016/j.neurol.2018.07.001. ­­­

Images drawn by Isra Ahmed ‘23

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Saving the Arctic with Glass

DEVI CHOWDHURY `24

Arctic Amplification and Loss of Biodiversity The release of greenhouse gases is causing temperatures in the Arctic to warm at twice the rate of the rest of the world in a phenomenon referred to as Arctic Amplification. One of the main concerns regarding climate change within the Arctic is a reduction in sea ice, which decreases the planetary albedo (reflectivity of the surface to solar radiation), and increases absorption of solar radiation and the global mean temperature. Lower levels of sea ice, melting permafrost, and rising sea levels threaten the biodiversity of the Arctic ecosystem as many species are restricted from accessing proper shelter and food sources. Although reducing greenhouse gas emissions will diminish these issues, it is not enough to protect the Arctic ice (1). For the past decade, the Arctic Ice Project has made it their mission to restore Arctic ice by utilizing a protective barrier to minimize the cumulative stresses imposed on the Arctic ecosystem. Some scientists argue that implementing such an unconventional technique could potentially compromise rehabilitation, endangering the ecosystem and biodiversity. In light of these concerns, it is important that geoengineering research is tailored to account for possible negative side effects. By combining geoengineering efforts such as protective barriers with climate modeling, researchers have a more holistic understanding of the effects of such techniques and they play a key role in developing more immediate resolutions to protecting the Arctic climate.

Arctic Ice Project Lead engineer of the Arctic Ice Project, Leslie Field, proposed a solution of scattering a thin layer of reflective glass powder over the Arctic surface to expedite the restoration of the Arctic ecosystem. This restoration

Silica beads reflect sunlight, allowing Arctic ice to stay cooler

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technology, known as Solar Radiation Management (SRM), aims to reduce the amount of solar radiation absorbed by the Earth by providing an additional layer of reflective protection on the Arctic ice, promoting ice regrowth, and potentially reducing the rate at which the Arctic ice melts (2).

Over the past decade, Field and her team have conducted many frozen lake field studies, scattering silica beads over several lakes in Canada and the United States, with exceptional outcomes.

Silica Beads Field and her team determined that silica would be the optimal substrate to effectively improve the reflectivity of sea ice without compromising the safety of the environment. Prior to conducting research and small-scale field tests on the effectiveness of the reflective beads, scientists ensured that the material for the reflective beads had the following characteristics: (1) high albedo (similar reflective properties as fresh snow), (2) lower density than water, (3) nontoxic, (4) hydrophilic properties to allow the surface to not have an affinity for oil–based pollutants, (5) small diameter (allowing minimal materials usage per unit area), (6) larger than respirable range to avoid inhalation effects and nanoparticle concerns, and (7) relatively low cost (3). Researchers at Covalent Metrology, an analytical laboratory, conducted a study to determine the relationship between the diameter of the silica beads, the albedo effectiveness, and the fraction of light transmitted using ultraviolet/visible/near-infrared spectrophotometry. The thickness of the silica ranged from 101.55 to 331 μm with an average granule diameter of 65 μm, and 1.5 to 5 monolayers of material were used as a coating (4). The results concluded that light transmission decreased as the silica thickness increased. Conversely, as the thickness increased, the albedo also

continued to increase. Therefore, scientists deployed silica beads of varying thicknesses to ensure optimal light transmittance and albedo. Additionally, environmental testing conducted in 2018 by EA Engineering, Science and Technology, Inc. found that the beads caused no deleterious effects in sheepshead minnows and northern bobwhites due to ingestion (4). Besides understanding the feasibility of the silica microbeads by analyzing its effect on the environment and high albedo, scientists ensured that the production of the microbeads were reasonable considering that silica SRM technology requires global implementation, which approximates to 68,000 tons of microspheres per year, to reduce the amount of solar radiation absorbed by the Earth (2). The raw material required to produce the microbeads, silica dioxide, is in ample supply to produce such large volumes of material so that it is not a limiting factor to production at this quantity. The findings of the field research confirm that silica is the ideal substrate material to promote ice growth, as it has a relatively high albedo, essentially decreasing absorption of solar radiation and the global mean temperature. Additionally, it has no detrimental impact on two species and does not compromise the safety of the environment. However, Field understands the complexities of introducing silica into the environment and concerns biologists may have, so researchers plan to evaluate the impact of the silica beads on the Arctic ecosystem through thorough field testing and computer modelling analysis.

Solar Radiation Management (SRM)

SRM aims to reduce the amount of solar radiation absorbed by the Earth, which is the focus of the Arctic Ice Project research and technologies.

Researchers of the Arctic Ice Project conducted small-scale deployments of Surface Albedo Modification (SAM) on frozen lake test sites in Minnesota and Alaska in 2017, among other locations, to determine the silica reflectiveness to solar radiation. Albedo and ice preservation performance was tracked using manual ice thickness measurements and automated cameras to record the performance of the materials and control areas, solar sensor pairs to determine albedo, strings of temperature sensors submerged in the ice and water below the instrumentation buoy, and tilt sensors (2).

The silica microbeads have a similar high albedo of .95 albedo to fresh snow because both are capable of reflecting up to 95% of the incoming radiation. This is important since water has a relatively low albedo of .10, reflecting only 10% of the incoming radiation. However, if the silica beads were introduced into bodies of water, the surface of the sea could increase in reflectivity (6). Results from small man-made ponds in Lake Elmo, Minnesota revealed that the albedo values for the test area coated with the microscopic silica beads were considerably higher than the untreated areas, increasing the albedo of the surface approximately by 15–20% (1). Similar

field experiments were conducted i n 2017 on a shallow lake in the Barrow Experimental Observatory Area in Barrow, Alaska by distributing the microglass manually by hand in premeasured amounts using a shaker. The silica significantly increased albedo. As a result, the surface reflects the majority of the radiation that hits it. However, the concern with land based material deployment methods as those applied i n Lakes Elmo and Barrow is that this specific form of deployment is not capable of sufficiently covering these large areas in a reasonable amount of time. Additionally, the terrain on sea ice is often very nonuniform and can change rapidly, making such an operation hazardous to people and equipment as well. As a result, researchers are investigating other forms of dispersal procedures for the silica microbeads that are safe and effective.

Still, despite these distribution issues, the microbeads themselves remain an integral component of the Arctic Ice Project so researchers continue to analyze the effect of this SRM technology on the different species through extensive field studies.

There are concerns regarding SRM technologies as it requires global implementation to effectively influence the climate, and it is unlikely that these geoengineering techniques will be deployed in the near future.

Although some argue that humans have caused climate change, it is vital to take into consideration the possible risks associated with preventative climate change measures prior to implementation. Biologists are concerned about the potential effects that the silica microbeads may have on photosynthetic organisms, compromising the base of the Arctic food chain.

Karina Giesbrecht, an ocean chemist and ecologist at Canada’s University of Victoria, has voiced concerns regarding the impact of silica in Arctic ecosystems due to the high probability that the highly reflective silica beads could block sunlight from photosynthetic plankton (1). However, computer modeling of ongoing experimentation on this technique have not indicated any adverse or unintended effects on places beyond the localized areas where SAM is utilized.

Climate Modeling To supplement field testing conducted on the efficacy of silica bead implementation, researchers have developed models to analyze the possible

Silica beads are scattered on the Arctic ice

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future detrimental effects of this form of geoengineering. Although the silica microbeads have many propitious properties that will help promote higher rates of albedo, researchers continued to analyze other factors and predict future complications with SAM through Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) Arctic Ice Volume Reanalysis. In this model, the sea ice volume is a product of the sea ice area and thickness.

PIOMAS was developed by the Applied Physics Laboratory to simulate and understand the mechanisms of the current Arctic decline and project the future Arctic states under different scenarios. It is currently the only sea ice data assimilation product and most accurate estimate available for the sea ice volume. Researchers conducted global sensitivity experiments to simulate the effect of the SRM technology on the Arctic sea ice area, volume, and surface temperature. The climate conditions from the control model projects the current climate and provides a baseline for comparison. The experimental model shows a long term positive trend in the sea ice albedo, with the average magnitude of the Arctic sea ice albedo increasing 10–15% compared to the control model. The modeled effect albedo modification to the Arctic correlates with the field testing results found by Field and her team, showing an increase in the albedo of the surface by approximately 15–20% in Lake Elmo, Minnesota. This reveals the albedo properties of the SRM technology is consistent with both field testing and climate modeling, making it a favorable prospect to help promote Arctic albedo over the years.

Additionally, compared to the control models, the experimental models exhibited a pattern of thicker ice in the Canadian Archipelago coast and Greenland and thinning toward the Siberian coast; the marginal zones in the North Atlantic and Pacific also varied in 0–5 m range. The treated experiments showed large scale thickening of the ice pack ranging from 0.2–1 m in the Canadian Archipelago. The impact was even stronger in the summer season where the central Arctic thickened with about 20–50 cm and covered with >1.5 m thicker ice. There were also notable increases in sea ice thickness (20–50 cm Arctic wide) and ice concentration (>15–20% across large parts of central Arctic) (7). Furthermore, the modeling study revealed more than 1.5°C cooler temperatures over a large part of the Arctic when simulating global sea ice albedo modification. In a region north of Barents and Kara Seas, temperatures have been reduced by 3°C and in North Canada by almost 1°C (8). Researchers understand that there are anomalies in the climate data of the Arctic surface models so in order to compare sea ice area, volume, and surface temperatures to a stable control model, they ran simulations spanning a 40 year period starting in 2000, to ensure that atmospheric state reached equilibrium and the biases in the

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radiative balance were reduced. It is important to understand that climate modeling projections depict that SRM technologies are relatively harmless and not as detrimental to the environment as some researchers fear. These results are a promising indicator of the mitigation potential that exists from prospective technologies that are capable of enhancing surface albedo of sea ice and reducing global temperatures over vast geographic areas. However, researchers should continue monitoring the climate model simulations and conduct further research because albedo modification is still a fairly new concept.

Implications Since scientists are apprehensive about utilizing geoengineering technology, such as Solar Radiation Management (SRM), it is crucial to conduct extensive field research to help them understand the side effects of SRM and determine the safety of implementing such measures as it is vital in preserving the Arctic climate and arctic ice. Utilizing geoengineering strategies, such as Surface Albedo Modification, is an extrinsic approach that requires extensive field testing and climate modeling to ensure that this technology is capable of restoring the Arctic ice, stabilizing the global temperatures, and mitigating the effects of climate change. Climate modeling technologies have a critical role in predicting adverse impacts of geoengineering strategies in various regions of the world, thus allowing policymakers and international bodies to assess which technologies or strategies will be the most advantageous and predict risks to be avoided. It falls to researchers to constantly review and analyze other potential ice preservation technologies to ensure that climate research consists of the most promising technical approaches while minimizing risks associated with their implementation.

References 1. K. Zimmer, The daring plan to save the arctic ice with glass. Future Planet, (2020).

2. J. Barclay, Geoengineering in the Canadian Arctic: governance challenges. North American and Arctic Defense and Security Network, (2021).

3. M. Payne, et al., Technology focus areas. Arctic Ice Project, (2021).

4. L. Field, et al., Restoring arctic albedo through rebuilding ice reflectivity in the arctic. Advancing Earth and Space Science, (2019).

5. T. Sutterley, et al., Piomas arctic sea ice volume reanalysis. Polar Science Center, (2021).

6. D. Dello, Albedo. North Carolina Climate Office, (2017).

7. D. Perovich, et al., Arctic report card: update for 2018 sea ice. Arctic Program, (2018).

8. A. Peters, Can spreading tiny glass beads on the arctic ice keep it from melting? World Changing Ideas, (2019).

Graphics created by Ujala Dar `24

PRESYNAPTIC INHIBITION OF GABAA RECEPTORS POSSIBLE IN THALAMOCORTICAL CIRCUITS VIGNESH SUBRAMANIAN ’24 A number of neurodegenerative disease processes, including those of temporal lobe epilepsy, GABA-transaminase deficiency, and traumatic brain injury, involve disruptions to the signalling pathway of gammaaminobutyric acid (GABA), the chief inhibitory neurotransmitter of the central nervous system. Conventional understanding divides the ability of GABA to block neural signaling into ‘presynaptic inhibition’ involving suppression of glutamate release, an excitatory counterpart neurotransmitter - and ‘postsynaptic inhibition’, involving changes in electrical conductance along membrane potentials. These functions are enabled by the presence of GABAB and GABAA receptors at presynaptic and postsynaptic terminals, respectively. However, evidence of GABAA receptor presence at presynaptic terminals in the hippocampus, sensory neocortex, and cerebellum suggests long-term potentiation between neurons may be regulated at alternative sites of action. To establish whether such presynaptic inhibition at GABAA receptors rather than GABAB may also be possible in neocortical circuits (those concerning higher cognitive functioning), Stony Brook researcher Dr. Arianna Maffei and her team examined evoked inhibitory currents in Layer 4 (L4) of the rat primary visual cortex (V1) to determine the effects of GABAA receptor agonists.

Researchers first immersed V1containing acute coronal slices of P14 rats in bath applications of drugs diazepam (DZ) and muscimol (Mus), both GABAA receptor agonists, and collected patch clamp recordings of signaling between subjects’ pyramidal (Pyr) and fast spiking (FS) neurons, which conduct thalamocortical (TC)

(visual, somatic, and auditory) inputs. Terminal field photostimulation and coimmunostaining protocols were then applied to neuronal axons in the lateral geniculate nucleus - a specific cortical region communicating with L4 neurons - and selectively expressed neurotransmitter transporters to determine effects on signal potentiation and receptor localization.

It was found that Mus-sensitive GABAA receptors insensitive to DZ binding were capable of modulating the amplitude and variation of excitatory currents at FS and Pyr neurons, and that Mus-induced local reduction of inhibitory currents could presynaptically occur. The data also demonstrated how the puncta of presynaptic GABAA receptors capable of decreasing TC transmission could be detected at TC terminals in V1, as well as how bursts of inhibitory neuron-fired GABA could be correlated with immediate suppression of excitatory potentiation.

The findings of this study substantiate the presence of presynaptic GABAA receptors capable of blocking TC transmission both locally and in response to afferent inputs in L4 of the primary visual cortex.

The novel knowledge that such receptors exist in neocortical circuits underscores the existence of alternative mechanisms by which overstimulation from neurodegenerative disorders can be pharmacologically counteracted.

1. A. Maffei, et al., Presynaptic GABAA Receptors Modulate Thalamocortical Inputs in Layer 4 of Rat V1. Cerebral Cortex (Oxford Academic) 29, 921-936 (2019). doi: 10.1093/cercor/bhx364 2. Image retrieved from: https://pixabay.com/illustrations/artificial-intelligence-brain-think-4389372/

HOW DOES THE BRAIN LEARN TASTE AVERSION? AYESHA AZEEM ’23 The gustatory system is the sensory system that allows humans to perceive the sense of taste, or flavor. Humans are able to perceive different flavors via the taste receptors on taste buds, which can be found on the upper surface of the tongue as well as on the epiglottis. Taste perception depends on the chemical characteristics of the stimulus, as well as its hedonic value - its pleasantness or aversiveness. Hedonic value can be determined by one’s life experiences and may change over time if associated with bad memories. A powerful memory can be formed when a taste is associated with gastrointestinal pain in a process known as conditioned taste aversion (CTA). Dr. Arianna Maffei, a professor in the Department of Neurobiology and Behavior, led a Stony Brook University study in which she and other researchers conditioned rats to experience taste aversion sugar water, something they would usually enjoy, by creating gastric malaise after consumption.

The researchers fed female and male rats 0.1 M sucrose water and then immediately gave an injection of lithium chloride (LiCl), causing gastrointestinal distress in the rats. The researchers held two conditioning sessions to ensure the aversive memory was solidified. There was also a control condition in which the animals received the LiCl injection the night

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before they received the sucrose water. The researchers found that before the injection, the rats found the taste of the sugar water to be pleasurable and drank more of it in comparison to the baseline water provided. On the second conditioning day, the rats decreased their consumption of sucrose, holding a strong preference for the baseline water instead.

While the areas of the brain involved in taste aversion learning - the basolateral amygdala and the gustatory cortex in the insular cortex - have been known for quite some time, little is known about how these areas work together during learning processes. Professor Maffei and the other researchers found that CTA learning decreases the strength of the synaptic connections between the basolateral amygdala and the gustatory cortex, leading to a reduced activation of the gustatory cortex neurons. The study provides the first evidence that proves that learned taste aversion depends on the long-term reduction in the connections between the taste and threat sensors of the brain and implies that reducing the activity between two areas of the brain can affect the way animals learn other behaviors.

1. M.S. Haley, et al., LTD at amygdalocortical synapses as a novel mechanism for hedonic learning. eLife (2020). doi: 10.7554/eLife.55175.

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