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Journal of Undergraduate Science & Technology
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Journal of Undergraduate Science & Technology
UW-Madison's only undergraduate STEM research & communication journal
is RECRUITING for Fall 2021! editors | staff writers | designers and accepting submissions for: research reports | editorials | photographs
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LETTER FROM THE EDITOR-IN-CHIEF Dear Reader, I am elated to present to you with Volume VI, Issue II of the Journal of Undergraduate Science and Technology (JUST). JUST is truly a campus wide effort and a celebration of not only the extraordinary research that takes place on this campus, but the work conducted by undergraduates specifically. I would like to extend my sincerest thanks to the undergraduate researchers who submitted their work along with the faculty and staff who supported them. I would also like to express my gratitude for the JUST staff that have chosen to make JUST a part of their undergraduate experience and worked diligently to bring you this publication. Additionally, without the generous support of the Wisconsin Institute for Discovery, the Holtz Center for Science and Technology Studies, the College of Agriculture and Life Sciences, and Associated Students of Madison, the publication of this journal would not have been possible. JUST’s mission has always been to support undergraduate researchers and make science accessible to broader audiences. At UW-Madison, we have been uniquely able to provide the opportunity for undergraduates to publish their work in a peer-reviewed journal and give students a glimpse into the publication process of an academic journal. On the other hand, our staff gain exceptional skills and experience the publication process from the perspective of a producer in a scholarly journal. We believe that these experiences are an invaluable supplement to a traditional undergraduate education, especially for those students who wish to continue research. As for the second part of our mission, I believe that scientific literacy is more important than ever in today’s advancing society. STEM topics have immersed themselves in all aspects of daily life, and all of our lives can only be enriched by a solid understanding of scientific thought. Effective communication of research and science is key to this. We are honored to be a small part in a much larger effort to make research and scientific achievement more accessible to non-expert communities beyond academia. In many ways, the space we occupy on campus mirrors the tenets of the Wisconsin Idea: that the influence of the university should better people’s lives outside of the classroom and across the state. We believe that by helping to train the next generation of researchers and assisting in the dissemination of scientific knowledge, JUST is helping to realize and advance the Wisconsin Idea. JUST has brought me incredible opportunities to work with and support talented peers. It has truly been an honor to be a part of this organization and continue to forward its mission. In this issue of JUST, you will find a wide range of scientific disciplines represented both by our peer reviewed reports and our shorter editorials as well as the visual pleasure of scientific imagery. Please join us in making it a tradition to recognize the incredible research and thoughtful written pieces presented by UW-Madison undergraduates, and in our larger pursuit to support science literacy.
Sincerely,
www.justjournal.org | contact@justjournal.org Haley Dagenais JUST Editor-in-Chief JUST VOL VI // ISSUE II // SPRING 2021
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TABLE OF CONTENTS
SPONSORS & PARTNERS
EDITORIALS EDITOR-IN-CHIEF Haley Dagenais MANAGING EDITORS Aadhishre Kasat DIRECTOR OF FINANCE Revati Garg
We would like to sincerely thank the Integrated Studies in Science, Engineering, and Society Undergraduate Certificate Program [ISSuES] at UW-Madison; The College of Agriculture and Life Sciences [CALS]; The Wisconsin Institute for Discovery; the Associated Students of Madison (ASM) and Wisconsin Alumni Research Foundation for financially supporting the production of JUST’s Spring 2021 issue. Thank you!
Tala Shaibi
10. Plastic: The Environmental Pandemic Carter Wood
14. Staphylococcus epidermidis: The Microbe Inhabiting Our Skin Anna Feldman
17. Potential for COVID-19 reinfection creates a need for dynamic public health policies and continued vaccination efforts
DIRECTOR OF MARKETING Jenny Lee
Jacob Schleicher, Jack Kotler, & Tyler Yeomans
22. New Metric Designed to Measure a Farm's Ecosystem Services Developed at UW–Madison
DIRECTOR OF DESIGN Ashley Harris
Anna Feldman
24. Balancing Blood Sugars: The Evolution of Glucose Monitoring Myra Mohammad
WEBMASTER Eddie Estevez
26. Oceanic Bioinspiration: Looking to the ingenuity of Parrotfish, Manta rays, Sharks and Marbled Electric rays
MARKETING ASSISTANT Hannah Landsly
Leta Landucci
30. Reviving the American Chestnut: How Gene Editing can Bring Back an Iconic North American Tree Lydia Larsen
EDITORS OF CONTENT Nick Goetz Emma McCoy Catherine Nguyen Noah Jacobs Jaitri Joshi Joshua Lei Samantha Bebel STAFF WRITERS Leta Landucci Aislen Kelly, Head Staff Writer Anna Feldman Tommy Gillis Maddie Rabideau Anna Schwenn Tala Schaibi Myra Mohammad Carter Wood Lydia Larsen Mahak Kathpalia Sarah Kamal
6. Dancing Neurons and Their Exciting Impacts
32. The Myth of Multitasking Sarah Kamal
34. UW IceCube Neutrino Observatory searches for answers to cosmological mysteries using a notoriously elusive particle Tommy Gillis
PIXELS 36. Hannah Franzblau The Journal of Undergraduate Science and Technology (JUST) is an interdisciplinary journal for the publication and dissemination of undergraduate research conducted at the University of Wisconsin-Madison. Encompassing all areas of research in science and technology, JUST aims to provide an open-access platform for undergraduates to share their research with the university and the Madison community at large.
REPORTS 40. Investigating the Neural and Behavioral Differences of Ratio Processing in Males and Females Molly Pistono
50. Placenta Geometry in the 2nd Trimester Assessed with Magnetic Resonance Imaging Archana Dhyani
56. TNFa: A Potent Upregulator of CXCL2/3 in Human Endothelial Cells Colman I. Freel, Alexander R. Uy, Ying-jie Zhao, Chi Zhou, Jing Zheng
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SCIENCE + SOCIETY: How to be creative and effective in a rapidly changing environment
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J HEALTH
Figure 1. A depiction of the two brain hemispheres and the functions associated with each. Photo credit: Brainobrain dorffer, 2017). The right hemisphere is the creative headquarters of the brain as it also deals with multitasking, concentration, imagination, and many other processes we are capable of performing (Fig. 1). As a result, the arousal of this hemisphere brings about many benefits. Before we address these effects, let us take a closer look into the activities of neuronal systems in response to music.
Dancing Neurons and Their Exciting Impacts By Tala Shaibi
"As people listen to music, they undergo emotional rollercoasters. These varying emotional registers are attributed to changes in the listener’s brain activity."
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all the places you go to where music is present: restaurants, coffee shops, airports, malls, museums, laboratories, expositions, theaters, and even public restrooms. Music follows us wherever we go and impacts our daily lives on a personal and deep level. As people listen to music, they undergo emotional rollercoasters. These varying emotional registers are attributed to changes in the listener’s brain activity. Specifically focusing on music made using string instruments, the right hemisphere of the brain is activated when the listener experiences emotion (Trimble & Hes
Figure 2. An animated version of the pathway of sound waves from the ear to the brain. Photo credit: Harvard Health
Neuronal Processes As you might have already known, music travels in sound waves that go through your ears. The waves hit your eardrum and cause the hairs on the cochlea, the spiral cavity of the inner ear that produces nerve impulses in response to sound vibrations (Fig. 2), to vibrate. The
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Thousands of cultures, traditions, and values make up the many communities present worldwide. The overwhelming diversity of people around the globe is incomprehensible. There is, however, one thing that brings us all together. You might be thinking what I am thinking: music. Even though music comes in many different genres, ranging from rock, classical, pop, rap, R&B, and many more, the instruments used to make these music genres come alive are mostly the same in many cultures. The advent of music dates back to the early ages and is still present in all aspects of society today. Think about
stereocilia, hair organelles of the hair cells, are the primary structures used in sound transduction (Fig. 2). They are very important as the human ear has 20,000 hair cells covered in stereocilia (Schaefer, 2017). As you listen to music, the stereocilia bend, sending the signal to the auditory nerve, which relays it to the auditory cortex of the brain for processing (Schaefer, 2017). Because of the incredibly high speeds of the auditory system, signal detection and amplification can be processed by one hair cell (Schaefer, 2017). Different parts of the brain are activated depending on the loudness, tempo, pitch, and consonance of the sound. Functional neuroimaging studies on the human brain using MRI & PET scans, show that music activates the amygdala and the nucleus accumbens (NAc), two brain structures known to be crucially involved in emotion (Schaefer, 2017) (Fig. 3). The NAc is located in the mesolimbic system, sometimes called the reward center; it plays a huge role in generating pleasure and laughter, but also fear, aggression, impulsivity, and addiction (Schaefer, 2017). The positive emotions we experience when listening to music are associated with the release of dopamine (Fig. 4), a neurotransmitter associated with feelings of pleasure and many other processes. Dopamine release results in the excitation of one neuron to its neighboring neurons, resulting in positive emotions. You can kind of think of these excitations as dancing neurons — you’re not the only one having fun. The amygdala is the central headquarters of your brain’s emotional network. It works along with the hypothalamus, a structure involved in memory, sleep, emotion, and many other daily processes, to regulate the release of hormones, such as cortisol and endorphins. Lower cortisol levels correspond to a reduction in emotional stress, which is achieved when listening to pleasant music — talk about a benefit. In addition to the hypothalamus, the hippocampus, another brain structure found in the mesolimbic system dealing with memory and emotion, is also involved in regulating hormones. Interestingly enough, it has been seen in PET scan experiments that blood-oxygen-level dependent (BOLD) signals in the amygdala and the hippocampus decreased with pleasant music (Schaefer, 2017) (O’Kelly, 2016). Furthermore, the occurrence of chills increased in intensity as BOLD decreased when people listened to their favorite tunes (Schaefer, 2017). Keep in mind that these brain structures are interrelated in that one component is regulated by multiple structures as the signal activates many different neuronal pathways. For the sake of simplicity, you can think of these neuronal processes as responses to the onset of emotion during music listening. As these pleasurable sounds flow through our ears and into our brains, they initiate a dom-
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J ino effect from one brain structure to another, as well as between neurons. The participating brain structures relay the signal to each other, like passing the baton in a track relay race. The neurons in each brain structure associated with emotion are then activated and are now
Figure 3. Cortical areas of the brain activated in thhe onset of emotion, in this context, while listening to music. Photo credit: Thomas Baumgartner, Michaela Esslen, & Lutz Jäncke able to release “happy hormones”, such as dopamine and endorphins. The hormones released trigger physiological and emotional change, which results in a wide range of benefits.
Conclusion All of these intertwined and complicated brain processes react to music in a way that empowers physiological and emotional changes. Zooming into the neuronal processes occurring at each brain structure allows us to further understand the relationship between music and our bodies. Brain structures particularly involved in emotion activate through a neuronal pathway leading to the production of pleasure hormones. These hormones not only regulate bodily functions, but also lead to alterations in neuronal circuits and brain processes that provide the benefits associated with music listening. Such benefits include enhanced memorization, more effective listening strategies, stress reduction, and many more. The effects of music on the brain is a field of research that is still being investigated and developed. Further advancing our knowledge on these small-scale processes and their enormous potential allows for the creation of therapeutic techniques in the healthcare industry and unlimited more opportunities.
References Gao, C., Fillmore, P., & Scullin, M. K. (2020). Classical music, educational learning, and slow wave sleep: A targeted memory reactivation experiment. Neurobiology of Learning and Memory. 171. https://doi.org/10.1016/j.nlm.2020.107206. Integrating the two hemispheres of the brain. (2017, September 15). Retrieved March 02, 2021, from https://www.brainobrain.cz/en/2016/06/26/integrating-the-two-hemispheres-of-the-brain/ Kraus, N., & White-Schwoch, T. (2016). Neurobiology of everyday communication: What have we learned from music? The Neuroscientist, 23(3), 287-298. doi:10.1177/1073858416653593 Lam, K., & Jadavji, N. (2018). Seeking happiness: Understanding the mechanisms of mixing music and drugs. Journal of Young Investigators. doi:10.22186/jyi.34.5.31-38 Mankel, K., & Bidelman, G. (2018, December 18). Inherent auditory skills rather than formal music training shape the neural encoding of speech. Proceedings of the National Academies of Science. 115(51), 13129-13134. https://doi.org/10.1073/ pnas.1811793115 O’Kelly, J. (2016). Music therapy and neuroscience: Opportunities and challenges. (n.d.). Retrieved March 02, 2021, from https://voices.no/index.php/ voices/article/view/2309/2064 Publishing, Harvard Health. (2020, Feb.) “Hearing Loss in Adults.” Harvard Health. Retrieved March 20, 2021 from www.health.harvard.edu/diseases-and-conditions/hearing-loss-in-adults-a-to-z. Schaefer, H. (2017, November 24). Music-evoked emotions-current studies. Frontiers in Neuroscience. 11: 600. doi: 10.3389/fnins.2017.00600 Trimble, M., & Hesdorffer, D. (2017, May 1). Music and the brain: The neuroscience of music and musical appreciation. BJ Psych International. 14(2): 28–31. Weaver II, E. A., & Doyle, H. H. (2019, September 19). Cells of the brain. Retrieved March 21, 2021, from https://dana.org/article/cells-of-the-brain/
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Benefits of Music These complicated changes occurring in our
neuronal circuits change as they interact with the environment. It has been found that the neuronal pathways activated for the duration of music enjoyment improve memory on knowledge-performance STEM exams (Gao et al, 2020). You heard that right, ditch those practice exams and get on that classical music — just kidding, but do get on that classical music. In addition to memory, a link has been found between music and listening; music may change the listening strategies of the brain, further improving the understanding of speech as it is processed with slightly different cues (Kraus & White-Schwoch, 2016) (Mankel & Bidelman, 2018). Surprisingly enough, music also strengthens sound-to-meaning connections — this skill comes hand-in-hand with language as learning new sounds can be hard without those elaborative conditioning skills. The benefits of music are too many to count, so in light of these benefits, scientists developed the field of musical therapy. The impact these tiny dancing brain cells can have on us is too good to be true. Let us show them some appreciation with a moment of silence, or rather, a moment of classical music.
Figure 4. The molecular structure of dopamine, a neurotransmitter. photo credit: Stefan Koelsch
brains as we listen to music are not all for nothing. There is a process called neuroplasticity in which the brain’s 8 JUST VOL VI // ISSUE II // SPRING 2021
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J ENVIRONMENT
Fig. 1. Leo Baekeland analyzing a flask. Photo by the Brown Brothers.
Plastic: The Environmental Pandemic
year and being used in everything from bottles to carpets, PET has further edged us into a plastic dominated world (Fox, 2020; Service, 2020). While incredibly convenient in its uses, plastic is extraordinarily dangerous for our environment, animals, and even potentially humans. According to the United Nations, it is estimated that every year, more than 8 million tons of plastic finds its way into our oceans, affecting more than 800 species of aquatic wildlife and killing 1.1 million animals annually. This estimate of the extensive impacts of plastic is expected to double over the next several years, with scientists predicting that 16 million tons of plastic will infiltrate our aquatic environments by 2025 (City of Westminster, 2021).
Beyond wildlife, the unprecedented amount
By Carter Wood
In 1907, Leo Baekeland synthesized the first synthetic plastic in his chemistry laboratory in the United States (Ritchie, 2018). Baekeland’s new product, called Bakelite, rapidly revolutionized the world of manufacturing. As a cheaper, more flexible, and extremely diverse compound, Bakelite’s usage exploded and infiltrated all aspects of production. Cars, jewelry, architecture, radios, electrical systems and more all utilized Baekeland’s new “Material of a Thousand Uses,” albeit with little thought of its potential consequences (ACS). 10 JUST VOL VI // ISSUE II // SPRING 2021
Over the previous century, since its introduction into our world’s manufacturing scene, plastic production has skyrocketed, with nearly 8.3 billion tons of plastic created over the last 60 years (City of Westminster, 2021). Today, there is nearly 380 million tons of plastic produced each year, a number which continues to grow (Plastic Oceans International, 2021). Polyethylene terephthalate (PET), the current plastic being synthesized, is newer, cheaper, and more effective than any plastic that has been developed since Bakelite (Service, 2020). Produced to the scale of 70 million tons per
Fig. 2. Polyethylene terephthalate is the world's current most popular plastic compound. Photo by Wikipedia. of plastic present in our environment is also impacting humans, mainly by the daily inhalation of microplastic particles (Yale School of the Environment, 2020). Airborne microplastics are created through both the breakdown and production of plastic materials, and they end up in our air, foods, and drinks (Vianello et al., 2019). Upon inhalation, microplastics travel through the airway to the alveoli of the lungs, embedding themselves deep within. Although the exact toxicity of microplastics is still under investigation, it is known that they often carry upon themselves metals, pollutants, dyes and pigments, all of which can lead to negative
Fig. 3. Turtle trapped by plastic netting. Photo by National Geographic.
degrades over a timespan of 400 years, its accumulation has worsened to become an unprecedented crisis (City of Westminster, 2021). As a result of being unable to appropriately and effectively reuse plastic, the world has turned to producing more and more of it, often utilizing environmentally destructive oil extraction to synthesize it (Yale School of the Environment, 2020). Aware of the looming plastic dilemma, scientists have been working diligently to improve the processes that we use to dispose of PET plastics. In 2012, researchers at the University of Osaka in Japan discovered an enzyme in leaf compost that catalyzes the breaking down of PET plastic. Leaf and Branch Compost Cutinase (LLC) attacks PET on a chemical level, snipping apart the plastic’s two fundamental building blocks, terephthalate and ethylene glycol, and leading to the plastic’s degradation. It’s an extremely slow process that takes days to break down any appreciable amount of plastic, but at the time it was one of the most promising discoveries that had been made and gave many hope for a sustainable future. (Service, 2020). Most recently, scientists have created an enzyme that decomposes plastic 6 times faster and more productively than ever before. By succeeding in cou-
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"Over the previous century, since its introduction into our world’s manufacturing scene, plastic production has skyrocketed, with nearly 8.3 billion tons of plastic created over the last 60 years."
human health effects (Vianello et al., 2019). A common misconception regarding the disposal of plastic is that the act of recycling negates plastic’s harmful impacts on the environment. This is only a partial truth, as the vast majority of plastic produced is not actually recycled. Of the 8.3 billion tons of plastic produced over the last half century, 90% remains unrecycled (City of Westminster, 2021). It is estimated that only 10% of all plastic used in the United States is appropriately recycled, and of that 10%, most of the plastic is simply reduced into lower grade plastic for reuse, eventually finding its way to a landfill (Fox, 2020; Service 2020). Up to this point, we have lacked an efficient, productive manner to appropriately degrade and remove plastic from the environment, and since plastic
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bottles. Science | AAAS. Retrieved April 7 from https:// www.sciencemag.org /news/2020/04/huge-step-forward-mutant-enzyme-could-vastly-improve-recycling-plastic-bottles
Pacific Plastic Dump. (2018). [Photograph]. Phys Org. Retrieved April 7 from https://phys.org/news/2018-03pacific-plastic-dump-larger.html
Vianello, A., Jensen, R.L., Liu, L. et al. Simulating human exposure to indoor airborne microplastics using a Breathing Thermal Manikin. Sci Rep 9, 8670 (2019). https://doi.org/10.1038/s41598-019-45054-w
Ritchie, H. (2018, September 1). Plastic Pollution. Our World in Data. Retrieved April 7 from https://ourworldindata.org/plastic-pollution
Fig. 5. PET-ase enzyme. Photo by Wikipedia.
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As our world continues to manufacture plastic at an unprecedented rate, it is more important now than ever before that we realize that plastic is one of the countless environmental pandemics threatening our world, and that we must give the appropriate attention to the severe plastic crisis that we are facing. With the creation of the MHETase-PETase enzyme, there is hope for future where plastic is responsibly created and disposed of, saving the lives of millions of living beings and while protecting the integrity of our planet for generations to come.
Schippmeister. (2019, October 10). Polyethylene terephthalate [Illustration]. Wikipedia. Retrieved April 7 from https://en.wikipedia.org/wiki/Polyethylene_terephthalate
Wikipedia. (n.d.). PETase [Illustration]. Wikipedia. Retrieved April 7 from https://en.wikipedia.org/wiki/ PETase Yale School of the Environment. (2020, October 2). New Super-Enzyme Can Break Down Plastic at Rapid Pace. Yale E360. Retrieved April 7 from https://e360. yale.edu/digest/new-super-enzyme-can-break-downplastic-at-rapid-pace
References: ACS. Bakelite First Synthetic Plastic - National Historic Chemical Landmark. American Chemical Society. Retrieved March 3, 2021, from https://www.acs.org/ content/acs/en/education/whatischemistry/landmarks/ bakelite.html Chias, J. Turtle Trapped in Plastic Netting [Photograph]. National Geographic. Retrieved April 7 from https://www.nationalgeographic.com/magazine/article/plastic-planet-animals-wildlife-impact-waste-pollution City of Westminster. (2021, January 8). Plastic Waste and Pollution [Everything You Need To Know In 2020]. Commercial Waste. Retrieved April 7 from https://
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pling the enzyme PETase and mutant versions of itself together, scientists have created a super enzyme, one that could not form naturally due to its physical size and complexity (Yale School of the Environment, 2020). Like its predecessor, this new enzyme, called MHETase-PETase, works to target PET at its chemical building blocks, breaking it down and separating it to its original chemical states (Science Daily, 2020). This new discovery opens countless doors towards more sustainable plastic use in the future. With this technology, we have the ability to effectively eliminate and reuse plastic waste, removing it from our environment and dramatically reducing other environmentally damaging operations, such as oil, that we currently require to create new plastics.
Service, R. F. (2020, April 8). ‘A huge step forward.’ Mutant enzyme could vastly improve recycling of plastic
Leo Baekeland. (1909). [Photograph]. Investor’s Business Daily. Retrieved April 7 from https://www.investors.com/news/management/leaders-and-success/leobaekelands-plastic-reshaped-the-modern-world/
Plastic Oceans International. (2021, February 4). Plastic Pollution Facts | PlasticOceans.org/the-facts. Retrieved April 7 from https://plasticoceans.org/the-facts/
Fig. 4. Unrecycled plastic fills ocean waters. Photo by Phys Org.
Science Daily. (2020, September 28). Plastic-eating enzyme “cocktail” heralds new hope for plastic waste. Retrieved April 7 from https://www.sciencedaily.com/ releases/2020/09/200928152913.htm
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J MICROBIOLOGY
Fig. 1 (left): S. epidermidis operon responsible for biofilm formation (Le et al, 2018) Fig. 2 (right): Photo of a S. epidermidis biofilm (Le et al, 2018)
Staphylococcus epidermidis: The Microbe Inhabiting Our Skin By Anna Schwenn
"Microorganisms are constantly surrounding us and inhabiting our bodies. The human body harbors between 10-100 trillion symbiotic microbial cells, which is known as our microbiome."
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lococcus can provide an additional defense barrier against cancer. Experiments have been conducted with the DNA of Staphylococcus epidermidis MO34 that have shown suppression in host tumor size, due to its production of 6-N-hydroxyaminopurine (6-HAP). While possessing the MO34 strain of S. epidermidis on your skin may seem like an advantage, that same microbe has also been linked to acne and skin infections when displaced or out of equilibrium. Balance, moderation, and conditions are huge themes of the human microbiome, and by using S. epidermidis as an example organism, its beneficial associations with cancer and negative associations with infection can be examined.
ribosome, its correct location for protein synthesis, the siRNA guided the mRNA into the endoribonuclease enzyme complex (RISC) where the mRNA’s message was degraded, and the gene was never expressed (“Gene Silencing”). When the keratinocyte’s mARC genes were silenced, the cells were no longer resistant to the 6-HAP molecule’s obstructive cell growth behavior. That suggested that the expression of mARC1 or mARC2 is a vital component of noncancerous keratinocyte’s 6-HAP resistance. If an individual possesses a strain of S. epidermidis in their microbiome that produces 6-HAP, they may have more protection against ultraviolet-induced skin cancer than someone whose S. epidermidis is incapable of 6-HAP synthesis. Statistically speaking, just like buying more lottery tickets increases your chance of winning, the more strains of Staphylococcus you have on your skin must increase your chance of 6-HAP production, right? Not exactly. Balance within the human microbiome is essential. What was once a beneficial microbe capable of preventing cancer, can turn into a harmful pathogen if the equilibrium becomes disturbed. This is known as an opportunistic pathogen. It does not infect healthy hosts, but once the microbe becomes displaced or the host becomes ill, the microbe takes its chance to attack and infection becomes present. S. epidermidis is capable of forming biofilms on surfaces, which is the organism’s main virulence factor in causing infection. Once attached to its host, S. epidermidis uses its polysaccharide intercellular adhesion (PIA) and its Poly-N-acetylglucosamine (PNAG) to form a biofilm matrix. The PIA and PNAG complexes are responsible for facilitating communication between the staphylococcal cell
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Being amid the COVID-19 pandemic, it would be easy for us to fear all aspects of microbiology. However, not all microbes cause disease and several organisms can actually be beneficial to humans. Microorganisms are constantly surrounding us and inhabiting our bodies. The human body harbors between 10-100 trillion symbiotic microbial cells, which is known as our microbiome (Ursell et al, 2012). Of these, Staphylococcus species, a bacterium, is the most common inhabitant present on our skin. Staphylococcus, commonly known as Staph, has a negative or problematic outlook within clinic and hospital care settings due to infection. Yet, most people are unaware that some Staphy-
Strains of Staphylococcus epidermidis that produce 6-HAP, a molecule that prevents DNA synthesis, are found to selectively inhibit reproduction of tumor cells without interfering with or damaging the normal keratinocytes of skin tissue. To study this idea, a research team at the University of California-San Diego injected mice with 6-HAP every 48 hours over a two-week period, and the mice showed no signs of toxicity as their weights remained constant (Nakatsuji et al, 2018). When the 6-HAP chemical compound was injected into melanoma cells, the tumor sizes decreased by over 50 percent compared to controls. They found that mice colonized by S. epidermidis capable of producing 6-HAP could reduce UV-induced tumors, unlike mice whose S. epidermidis was incapable of 6-HAP production. Research is still ongoing to determine exactly which strains produce 6-HAP, but it is known that S. epidermidis MO34 is capable of producing it. A crucial feature of the 6-HAP molecule is that it is capable of being selective with its obstruction of cell growth. The 6-HAP activity is controlled by mARCs, mitochondrial amidoxime reducing components (mARC1 and mARC2). The expression of mARC genes is much higher in noncancerous keratinocytes compared to cancer cells. To determine if increased mARC expression plays a role in 6-HAP’s selectivity or if another protein is responsible, researchers examined the genes through functional interference. Gene silencing was performed by siRNA, a small interfering RNA that targets mRNA during transcription, the process of converting DNA’s information into messenger RNA (mRNA), the blueprints of protein synthesis. After transcription, instead of the mRNA entering to the
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References Claudel, J. P., Auffret, N., Leccia, M. T., Poli, F., Corvec, S., & Dréno, B. (2019). Staphylococcus epidermidis: A Potential New Player in the Physiopathology of Acne? Dermatology, 235(4), 287–294. https://doi. org/10.1159/000499858 Gene Silencing. (n.d.). Retrieved March 08, 2021, from https://www.ncbi.nlm.nih.gov/probe/docs/applsilencing/ Le, K., Park, M., & Otto, M. (2018, February 15). Immune evasion mechanisms of Staphylococcus epidermidis biofim infection. Frontiers in Microbiology, 9, 359. doi.org/10.3389/fmicb.2018.00359 Nakatsuji, T., Chen, T. H., Butcher, A. M., Trzoss, L. L., Nam, S. J., Shirakawa, K. T., Zhou, W., Oh, J., Otto, M., Fenical, W., & Gallo, R. L. (2018). A commensal strain of Staphylococcus epidermidis protects against skin neoplasia. Science advances, 4(2). https://doi.org/10.1126/sciadv.aao4502 Ursell, L., Metcalf, J., Parfrey, L., & Knight, R. (2012, August 01). Defining the human microbiome. Nutrition Reviews, 70(1), S38-S44. doi.org/10.1111/j.17534887.2012.00493.x
COVID–19
Potential for COVID-19 reinfection creates a need for dynamic public health policies and continued vaccination efforts By Jacob Schleicher, Jack Kotler, & Tyler Yeomans "In a world that is limping its way through an unprecedented pandemic crisis, it is more important now than ever before that we give respect and understanding to the invisible inhabitants of the world." The COVID-19 pandemic has been the source for one of the most captivating years in our lifetime, for this pandemic arose because of the rapid spread of coronavirus and its fatal effects on the human body. The pandemic caused a worldwide lockdown which mandated everybody but essential workers being confined to their homes, and it revealed new questions about the emergent disease, one of the biggest being how long someone can be immune from COVID-19 reinfection. As vaccinations are being distributed, the world is currently experiencing a decline in cases for positive COVID-19 tests. An article by Tillett et al., published on January 1st 2021, attempts to answer
this issue by concluding that it is unknown whether it is possible to be protected or immune from reinfection by SARS-CoV-2, or coronavirus. A virus spreads by replicating its genome strands in a host cell. Mutations in a virus produce new strains of the virus which resemble a modified version of that virus. This portrays to the public how important it is that we look further into this issue of reinfection because the whole world’s personal health is at stake. There is not only the issue of being reinfected with COVID-19, but also the unknown longterm effects of reinfection on our physical health. In this stage of the pandemic, public health policies and JUST VOL VI // ISSUE II // SPRING 2021 17
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wall and the biofilm extracellular matrix, shown in purple in Fig. 2 (Le et al, 2018). The PIA compound is produced by the icaADBC operon, which is a set of linked genes responsible for protein synthesis, shown in Figure 1 (Le et al, 2018). Each membrane protein (IcaA, IcaC, and IcaD) produced by the operon has an individual function, as well as the IcaB protein that is attached to the staphylococcal cell surface. IcaA (a N-acetylglucosaminyltransferase, a key enzyme in glycoprotein biosynthesis) and IcaD speed up the conversion of UDP-N-acetylglucosamine into 10–20-mers of a-1,6linked poly-N-acetylglucosamine (PNAG). The purpose of the IcaC protein is to extend the N-acetylglucosamine to produce a longer biofilm strand, and the IcaB protein is responsible for controlling the location of PIA on the S. epidermidis cell surface by performing deacetylation, the removal of acetyl. This biofilm can occur on human skin, and by doing so, it can keep the S. epidermidis protected from phagocytosis of effector cells, a human defense mechanism. For S. epidermidis to remain a commensal microbe that does not cause harm, biofilm production needs to be prevented. Also, to avoid infection, the skin microbiome’s equilibrium between organism abundance ratios must remain adequate. Having healthy skin is a balancing act between Staphylococcus epidermidis and Cutibacterium acnes. Both of the microbes are present on our skin. In healthy skin, S. epidermidis controls the reproduction of C. acnes to prevent the over-colonization of C. acnes, which leads to acne (Claudel et al, 2019). If someone struggles with acne, one might assume that getting rid of C. acnes entirely may be the answer. However, a disequilibrium in favor of S. epidermidis also may result in negative consequences like a nosocomial infection. Therefore, harmony among the skin microbiome is a fundamental component of healthy skin homeostasis. A balanced presence of life on our skin is essential for the health of our bodies. The human microbiome is beyond fascinating as each person’s microbial diversity can be compared to the diversification among fingerprints. Due to the COVID-19 world pandemic, the public has had an increased interest in the microbial world, and the word “bacteria” is often only seen in a negative connotation. However, it should be emphasized that bacteria are involved in more than just causing disease. With 70% of skin cancer reported being caused by repeated exposure to the sun’s UV rays, it is possible that numerous cases were prevented due to S. epidermidis strains that produce 6-HAP. By using S. epidermidis as an example organism and examining its associations with cancer and infection, the microbe can be either beneficial or harmful depending on its host conditions and the microbial strains present.
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J vaccination efforts must be updated according to the current stage of the pandemic to adapt to this period of grave uncertainty. What Are Coronaviruses?
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The Issue of Reinfection To provide the safest public health procedures for people to follow, numerous scientists and healthcare 18 JUST VOL VI // ISSUE II // SPRING 2021
first infected them. So when a new strain of coronavirus comes in contact with the body, there are no memory cells, or defense systems — that know how to attack the virus — available to fight off the new viral infection (Quast et al., 2021). In Fig. 1, you can see the single-stranded RNA that is responsible for the structure of the spike proteins attached to the envelope of
the virus. Each strand of virus varies genetically, resulting in spike proteins that interact with host cells differently depending on the virus (Robson, 2020). Thus, novel spike proteins cannot be recognized by the body’s memory cells, which results in reinfection. As more and more case studies are analyzed, scientists will continue to improve current knowledge regarding reinfection to safely and effectively combat it. Methods for Containing COVID-19 During this pandemic, scientists have continued to work diligently to brainstorm ideas for containing the virus and inhibiting its rapid transmission rate. Some methods utilized include social distancing guidelines and vaccine production. New knowledge on the possibility of reinfection has complicated these efforts. Many scientists have discussed the idea of herd immunity, which is when the spread of a disease or virus is diminished almost entirely due to a large enough portion of the population already being immune. It has been suggested that herd immunity may not work against COVID-19 and reinfection symptoms may be milder than the initial infection. This means it is highly likely that COVID-19 will circulate in the human population as a seasonal virus (Prado-Vivar et al., 2020). It is likely that the virus will stick around for a while, no matter how many people get infected. This also suggests that wearing masks and social distancing may never go away (Prado-Vivar et al., 2020). If COVID-19 does indeed progress into a seasonal virus such as the flu, the current health safety precautions such as mask wearing and social distancing may need to become the new norm, due to the fact that COVID is indeed quite different and much more contagious and deadly than the flu. This, however, could be dependent on the production and distribution of a vaccine. Moving forward, there is an urgent need for a vaccine (Dearlove et al., 2020). Since there is little genetic diversity in coronaviruses, especially in SARSCoV-2, there is a confidence that a single vaccine could effectively protect from nearly all mutations of SARSCoV-2 for several years at a time (Dearlove et al., 2020). This means that the difference in the variuous mutations of COVID-19 are genetically similar enough that a single vaccine can protect against all of them. This is evidently different from other common viruses such as HIV-1 or influenza. That indicates that COVID-19 mutant strains will not be a hurdle in vaccine development for scientists and epidemiologists (Dearlove et al., 2020). Until most of the public can receive a vaccine, the precautions that have been set forth for the past few months must remain in place. Moving Forwards in the Pandemic As cases continue to spike across the country, along with the possible risk of reinfection, there is a growing need for the continuation of our current precautions,
even as some push for decreased regulations. The Biden administration must not abandon the regulations that are in place at the moment. There must be a continuation of RT-PCR testing, among other forms of viral testing. RT-PCR tests, also known as reverse transcription polymerase chain reaction tests, continue to be the most common and effective tests for detecting COVID-19 (Singanayagam et al., 2020). Readings from RT-PCR show the number of infectious viruses in one’s body. High levels from an RT-PCR test reading would implicate, increased viral activity in the body, potentially necessitating a longer self-quarantine period (Singanayagam et al., 2020). After ten days of initial symptoms, the chance of an infectious virus remaining in your body is at about 6% (Singanayagam et al., 2020). However, the probability is about 8% when the RT-PCR readings are higher than 35 (Singanayagam et al., 2020). That means those individuals with higher levels are more likely to be infected and, subsequently, highly contagious. Although there is a great deal of research being conducted, there is still much unknown about SARS-CoV-2 due to its novelty. Plenty still needs to be learned regarding what makes a person asymptomatic or not and the subsequent implications about their ability to transmit the virus. Due to this lack of knowledge, high levels of testing are necessary for everyone, even if they don’t experience symptoms, because they could still potentially transmit the virus just as much as someone who is experiencing symptoms. Continued research regarding this topic is crucial moving forward, especially if COVID-19 will be sticking around for longer than initially expected. Further research is also necessary to confirm the studies that show reinfection is indeed possible. To know if someone has been re-infected, it must be proven that each infection was caused by a genetically distinct variant of the virus (Prado-Vivar et al., 2020). Showing this variation in infection would confirm those studies. Finally, the study of antibodies must be continued further, particularly regarding whether or not antibodies protect from from new strains of the virus. It needs to be established whether or not a weak immune response to the virus can lead to re-infection with symptoms against these new and emerging mutated virus strains. With the current state of COVID-19 still seeing new record highs, the urgency of this situation is clearly evident. As much information as possible needs to be verified in order to have the best chance at taking down COVID-19 and potentially halting the pandemic. The continuation of research efforts will help scientists and world leaders create dynamic health policies backed by scientific research to improve universal health. Research on COVID-19 will continue until an efficient vaccine is available for all demographics, and everyone must continue to follow public health guidelines to ensure the safety of themselves and those around them. JUST VOL VI // ISSUE II // SPRING 2021 19
EDITORIAL
Public health policies and vaccine research stem from the constant flow of new information discovered in research labs worldwide. Coronaviruses have been detected in humans and animals for many years prior to the COVID-19 outbreak (Alanagreh et al., 2020). Before 2003, coronaviruses were not considered dangerous to humans because of their similar symptoms to the flu, such as fever, cough, and fatigue that only persisted for a handful of days (Shereen et al., 2020). However, we now know that COVID-19 has the potential to show far more deadly and harmful symptoms than the flu, inlcuding pneumonia, respiratory failure, and, in some cases, death (Sheikhi et al. 2020). These harsher outcomes are associated with individuals of older age, especially for those older than 60 years, with increasing mortality rate for each subsequent decade range (Bonanad et al. 2020). The first coronaviruses labeled as deadly were the Severe Acute Respiratory Syndrome (SARS CoV) and the Middle East Respiratory Syndrome (MERS) (Petrosillo et al., 2020). SARS CoV originated from China in 2002 where, like COVID-19, it soon spread to the rest of the world. SARS CoV, however, is far less infectious than COVID-19 with a fatality rate of ~10% (Murphy, n.d.). In comparison, MERS emerged in the Arabian Peninsula in 2012 with a mortality rate of 3040%. MERS is significantly less infectious with approximately 1,370 confirmed cases worldwide (Murphy, n.d.). SARS CoV and MERS are believed to be zoonotic viruses originating from bats. SARS CoV, MERS, and COVID-19 all are classified as coronaviruses, so scientists successfully used the genetic information from SARS CoV and MERS to help map the DNA sequence of the novel COVID-19 (Alanagreh et al., 2020). COVID-19 is believed to have originated from the wet markets in Wuhan, China, where it was transmitted from animals to humans. Scientists uncovered a long chain of transmissions starting with the bats located at these markets. From bats, inter-species transmission led to the infection of other animals sold at the wet market such as dogs, cats, pigs, camels, and other species of bats. Following these inter-species transmissions, humans contract the virus when they purchase and eat these animals (Shereen et al., 2020). Since the origin of COVID-19 and its harmful impact on millions around the world, scientists have been working around the clock to identify the DNA sequence of this strand of coronavirus.
workers have been working tirelessly on the science and statistics of reinfection. With the information available today, many people agree that the contagiosity of a virus peaks at the onset of symptoms and steadily decreases as time passes (Grant et al., 2020). One study concluded that a person has a 6% chance of having the infectious virus in their body ten days after their first symptoms (Singanayagam et al., 2020). Although extensive long-term research on COVID-19 reinfection is rare at this point, scientists have analyzed other strains of coronavirus to get an idea of the type of immunity that the COVID-19 virus may possess. Many have focused on four seasonal coronaviruses to become more educated on the length of protection from reinfection (Edridge et al., 2020). One study found that COVID-19 reinfection typically occurred after twelve months but has also been observed to some degree after six months (Edridge et al., 2020). Another aspect that has been researched is the differences of age and gender in terms of infection of COVID-19. One study done in England found no correlation between susceptibility to infection and age or gender (Alanagreh et al., 2020). Thus, researchers from this study believe that COVID-19 reinfection would follow similar trends in terms of age and gender. So far, several research labs have studied various case studies of COVID-19 reinfection and have all come to very similar conclusions. By analyzing the virus genome, scientists have found that reinfection occurred when the person was infected a second time with a genetically different virus (Tillett et al., 2020; Larson et al., 2020; Van Elslande et al., 2020; Prado-Vivar et al., 2020). That is not surprising because a person’s body is only immune from the initial strain that
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J References Alanagreh, L. A., Alzoughool, F., & Atoum, M. (2020). The human coronavirus disease COVID-19: its origin, characteristics, and insights into potential drugs and its mechanisms. Pathogens, 9(5), 331. DOI: 10.3390/ pathogens9050331 Bonanad, C., Garcia-Blas, S., Tarazona-Santabalbina, F., Sanchis, J., Bertomeu-González, V., Facila, L., et al. (2020). The effect of age on mortality in patients with COVID-19: a meta-analysis with 611,583 subjects. Journal of the American Medical Directors Association, 21(7), 915-918. DOI: 10.1016/j. jamda.2020.05.045 Dearlove, B. L., Lewitus, E., Bai, H., Li, Y., Reeves, D. B., Joyce, M. G., et al. (2020). A SARS-CoV-2 vaccine candidate would likely match all currently circulating strains. bioRxiv. doi: https://doi.org/10.1101/2020.04.27.064774 Díaz, A., Beleña, Á., & Zueco, J. (2020). The role of age and gender in perceived vulnerability to infectious diseases. International journal of environmental research and public health, 17(2), 485.
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Larson, D., Brodniak, S. L., Voegtly, L. J., Cer, R. Z., Glang, L. A., Malagon, F. J., et al. (2020). A Case of Early Re-infection with SARS-CoV-2. Clinical infectious diseases: an official publication of the Infectious Diseases Society of America. DOI: 10.1093/cid/ciaa1436 Murphy, F. (n.d.). SARS and MERS. Retrieved March 19, 2021, from https://www.bcm.edu/departments/ molecular-virology-and-microbiology/emerging-infections-and-biodefense/specific-agents/sars-mers#:~:text=SARS%20is%20caused%20by%20SARS,reported%20 since%20the%20initial%20outbreak. Petrosillo, N., Viceconte, G., Ergonul, O., Ippolito, G., & Petersen, E. (2020). COVID-19, SARS and MERS: Are they closely related? Clinical Microbiology and Infection, 26(6), 729-734. doi:10.1016/j.cmi.2020.03.026 Prado-Vivar, B., Becerra-Wong, M., Guadalupe, J. J., Marquez, S., Gutierrez, B., Rojas-Silva, P., et al. (2020). COVID-19 Re-Infection by a Phylogenetically Distinct SARS-CoV-2 Variant, First Confirmed Event in South America. First Confirmed Event in South America. (September 3, 2020).
Quast, I., & Tarlinton, D. (2021). B cell memory: understanding COVID-19. Immunity, 54(2), 205–210. https:// doi.org/10.1016/j.immuni.2021.01.014 Robson B. (2020). COVID-19 Coronavirus spike protein analysis for synthetic vaccines, a peptidomimetic antagonist, and therapeutic drugs, and analysis of a proposed achilles' heel conserved region to minimize probability of escape mutations and drug resistance. Computers in biology and medicine, 121, 103749. https://doi.org/10.1016/j.compbiomed.2020.103749
Tillett, R. L., Sevinsky, J. R., Hartley, P. D., Kerwin, H., Crawford, N., Gorzalski, A., et al. (2021). Genomic evidence for reinfection with SARS-CoV-2: a case study. The Lancet Infectious Diseases, 21(1), 52-58. doi. org/10.1016/ Van Elslande, J., Vermeersch, P., Vandervoort, K., Wawina-Bokalanga, T., Vanmechelen, B., Wollants, E., et al. (2020). Symptomatic SARS-CoV-2 reinfection by a phylogenetically distinct strain. Clin Infect Dis, 10. doi.org/10.1093/cid/ciaa1330
Sheikhi, K., Shirzadfar, H., & Sheikhi, M. (2020). A review on novel coronavirus (Covid-19): symptoms, transmission and diagnosis tests. Research in Infectious Diseases and Tropical Medicine, 2(1), 1-8. DOI:10.33702/ridtm.2020.2.1.1 Shereen, M. A., Khan, S., Kazmi, A., Bashir, N., & Siddique, R. (2020). COVID-19 infection: Origin, transmission, and characteristics of human coronaviruses. Journal of advanced research, 24, 91-98. DOI: 10.1016/j. jare.2020.03.005 Singanayagam, A., Patel, M., Charlett, A., Bernal, J. L., Saliba, V., Ellis, J., et al. (2020). Duration of infectiousness and correlation with RT-PCR cycle threshold values in cases of COVID-19, England, January to May 2020. Eurosurveillance, 25(32), 2001483. doi. org/10.2807/1560-7917.ES.2020.25.32.2001483
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EDITORIAL
Edridge, A. W., Kaczorowska, J., Hoste, A. C., Bakker, M., Klein, M., Loens, K., et al. (2020). Seasonal coronavirus protective immunity is short-lasting. Nature medicine, 26(11), 1691-1693. doi.org/10.1038/s41591-020-1083-1
Grant, M. C., Geoghegan, L., Arbyn, M., Mohammed, Z., McGuinness, L., Clarke, E. L., & Wade, R. G. (2020). The prevalence of symptoms in 24,410 adults infected by the novel coronavirus (SARS-CoV-2; COVID-19): A systematic review and meta-analysis of 148 studies from 9 countries. PloS one, 15(6), e0234765. doi: 10.1371/journal.pone.0234765
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J erative in Canada, who said that the organization should create a toolkit to help farmers communicate their environmental impact. Initially, they envisioned the ecosystem services metric as solely a measure of a farm’s greenhouse gas emissions. Agriculture causes almost a quarter of global gas emissions, according to the EPA. The introduction of monoculture and large-scale conventional farming drastically changed the natural landscape worldwide and led to a decrease of carbon sequestration in the soil. When carbon isn’t stored in soil, it is released into the atmosphere and causes what is called the “greenhouse effect”: the gases trap heat in the Earth’s atmosphere, causing pollution and, ultimately, climate change (DeMets, 2020). However, while greenhouse gas emissions are an important measure of a farm’s sustainability, during the process of creating a metric for farmers to measure their carbon sequestration and emissions, it became apparent that quantifying these gas emissions is extremely complicated. Instead, the ecosystem services metric, which is currently beginning its initial stages of testing, focuses on six key aspects of how farms affect the ecosystem: farm infrastructure and machinery, livestock, soil practices, alternative power, biodiversity, and transportation to markets. Altogether, these components create a comprehensive overview of a farm’s environmental efforts.
ECOLOGY
into farms in the Midwest to have numerous other benefits including carbon sequestration, decreased water runoff, increased soil and nutrient retention, and increased bird and pollinator abundance (Schulte et. al, 2017). If you know a farmer who might be interested in helping to spread the word about their work to support a healthy ecosystem, then stay tuned for Farm 2 Facts’ new Ecosystem Services Toolkit. The toolkit will be available soon so you can enter data on your farm, and we’ll provide a personalized report quantifying their carbon emissions and retention, as well as provide pointers on how to integrate or improve your current environmental efforts. References: DeMets, C. (2020, December 02). Natural Climate Solutions. Retrieved from https://www.wisconsinacademy. org/magazine/summerfall-2020/report/natural-climateSolutions Global greenhouse gas emissions data. (2020, September 10). Retrieved February 28, 2021, from https://www.epa. gov/ghgemissions/global-greenhouse-gas-emissions-data Schulte, L. A., Niemi, J., Helmers, M. J., Liebman, M., Arbuckle, J. G., James, D. E., Kolka, R. K., et al. (2017, August 1). Prairie strips improve corn– soybean croplands. Proceedings of the National Academy of Sciences. 114(42), 11247-11252. doi.org/10.1073/ pnas.1620229114
New metric designed to measure a farm’s ecosystem services developed at UW-Madison By Anna Feldman
"Farm 2 Facts works with farms and farmers markets to help them collect and analyze data in order to measure their economic, social, and ecological impact."
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difference between them. Some products may have “organic” or “free range” labels, but these don’t capture the full extent of a farm’s efforts to conserve the natural environment. This is why Farm 2 Facts, a nonprofit organization affiliated with the Kaufman Lab at UW-Madison, created the Ecosystem Services Metric. Farm 2 Facts works with farms and farmers markets to help them collect and analyze data in order to measure their economic, social, and ecological impact. The concept for the Ecosystem Services metric came from a suggestion from a member of Farm 2 Facts from the Farmers Markets of Nova Scotia Coop-
The farmers are given a survey addressing each of these components which quantify their sustainability efforts. Information gathered in this research can then be used by farmers pursuing environmentally friendly methods to distinguish themselves and shown to farmers markets managers and other organizations to apply for grant funding to support their work and expand their efforts. This metric intends to celebrate farms for the beneficial methods that they use and suggest different ways to introduce further sustainability. An example of this would be planting native prairie strips in large monocrop fields to increase biodiversity. Prairie strips are low cost and were found by a 2017 study where prairie strips were integrated
EDITORIAL
When you go on a road trip to almost anywhere in the Midwest, you’re likely to drive through farmlands for hours, past huge fields of corn, soybeans, and pastures with cows grazing. However, these farms are not identical. While some stretch for miles with just one crop, or have a crowded pens filled with cows, there are other, often smaller, farms which are more diverse. The cows have space to roam among tall grasses, the corn is interspersed with natural landscape. In short, these farms’ practices are more environmentally sustainable. Unfortunately, once the products from the farms get to a store or a farmers market, it’s harder to tell the
Fig. 1. A prairie in Spring Green, Wisconsin. Photo by Anna Feldman.
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J HEALTH
Balancing Blood Sugars: The Evolution of Glucose Monitoring By Myra Mohammad
"Diabetes is an endocrinological issue that stems from uncontrolled blood glucose levels, which has the capacity to significantly damage critical systems in the body, if left untreated."
EDITORIAL
unaware of their illness, consequently remaining undiagnosed and untreated (CDC, 2018). Given the prevalence of the illness in the U.S., it’s growing increasingly important to examine the nature of diabetes, its history, and technology that’s currently being developed to alleviate the illness. Overview of Diabetes Diabetes is an endocrinological issue that stems from uncontrolled blood glucose levels, which has the capacity to significantly damage critical systems in the body, if left untreated (NIH, 2020). Symptoms of diabetes can include increased thirst, changes in appetite, blurred vision, and general fatigue (JDRF, 2020). Based primarily on varied
al 2016). The importance of these efforts can be evidenced by the many ways technological development has directly diminished the risk of a patient becoming hyperglycemic (experiencing high glucose blood levels) or hypoglycemic (experiencing low blood glucose levels). With diabetes on the rise, it’s important for both diabetics as well as non-diabetics to acquire a basic awareness of what diabetes entails and how it impacts the lives of those who have it. The ability to achieve homeostatic blood glucose levels is one fundamental means by which diabetics can begin to live their lives with less uncertainty and with more confidence. While tinkering with medical technologies might seem inconsequential in the moment, the true impact these seemingly minute changes can bear on the lives of millions of people is worthy of every moment of our attention. References Clarke, S. F., & Foster, J. R. (2012). A history of blood glucose meters and their role in self-monitoring of diabetes mellitus. British journal of biomedical science, 69(2), 83–93. Diabetes overview. (2016, December). Retrieved February 28, 2021, from https://www.niddk.nih.gov/health-information/diabetes/overview Diabetes tests & diagnosis. (2016, December 01). Retrieved February 28, 2021, from https://www.niddk.nih.gov/ health-information/diabetes/overview/tests-diagnosis Gary JayBourley. (2020). Differences between type 1 and type 2 diabetes. Retrieved February 28, 2021, from https:// www.diabetes.org.uk/diabetes-the-basics/differences-between-type-1-and-type-2-diabetes Hirsch, I. B., Battelino, T., Peters, A. L., Chamberlain, J. J., Aleppo, G., & Bergenstal, R. M. (2018). Role of Continuous Glucose Monitoring in Diabetes Treatment. Arlington, Va., American Diabetes Association. Klimek-Tulwin, M., Knap, J., Reda, M., & Masternak, M. (2019). History of glucose monitoring: past, present, future. Journal of Education, Health and Sport. 9, 222-227. 10.5281/ zenodo.3397600. Muegge, B. D., & Tobin, G. S. (2016). Improving Diabetes Care with Technology and Information Management. Missouri medicine, 113(5), 367–371. Prevalence of both diagnosed and undiagnosed diabetes. (2020, June 24). Retrieved February 28, 2021, from https:// www.cdc.gov/diabetes/data/statistics-report/diagnosed-undiagnosed-diabetes.html Symptoms & causes of diabetes. (2016, December 01). Retrieved February 28, 2021, from https://www.niddk.nih.gov/ health-information/diabetes/overview/symptoms-causes Statistics about diabetes. (2018). Retrieved February 28, 2021, from https://www.diabetes.org/resources/statistics/ statistics-about- diabetes#:~:text=Prevalence%3A%20 In%202018%2C%2034.2%20million,of%20the%20population%2C%20had%20diabetes.&text=Undiagnosed%3A%20Of%20the%2034.2%20million,and%207.3%20million%20 were%20undiagnosed. Symptoms. (n.d.). Retrieved February 28, 2021, from https:// www.jdrf.org/t1d-resources/about/symptoms/ Type 1 diabetes. (2020, August 22). Retrieved February 28, 2021, from https://www.mayoclinic.org/diseases-conditions/type-1-diabetes/symptoms-causes/syc-20353011
EDITORIAL
Introduction In the midst of a global pandemic, it may be easy to lose sight of the less volatile, though equally important illnesses that currently impact the health of millions of Americans. Although the vast majority of individuals have heard of the term “diabetes,” few are aware of what the illness actually entails and the magnitude of its impact here in the United States. As of 2018, approximately 8.2% of the population has been formally diagnosed with diabetes. This translates to about 26.9 million Americans, a number which is expected to increase by 1.5 million annually (ADA, 2018). Even this staggering statistic fails to incorporate the remaining 2.8% of Americans who, despite meeting laboratory criteria, do not report having diabetes, or are simply 24 JUST VOL VI // ISSUE II // SPRING 2021
origins of the illness, diabetes is divided into two distinct categories: type I and type II. Type I diabetes is sometimes classified as an autoimmune illness because the body attacks its own cells in the pancreas, an organ which is critical for the production of insulin. Insulin is the hormone responsible for regulating glucose levels in the bloodstream. Type II diabetes is often characterized by insufficient levels of insulin, or insulin that does not function properly. While type I diabetes is usually managed solely by insulin injection, type II diabetes can also be managed through exercise, medication supplements, and diet. In diabetic patients, a lack of effective insulin can result in uncontrolled blood sugar levels (Diabetes UK, 2020). As such, medical professionals often rely on blood tests, such as the fasting plasma glucose (FPG) test and the A1C test for diagnosis of diabetes (NIDDK, 2016). Many of these tests track changes in blood glucose levels to determine whether there’s an issue in glucose regulation. Once diagnosed, most diabetic patients use blood glucose tracking to effectively manage insulin levels and maintain normal blood sugar levels. Evolution of Blood Glucose Monitoring Over the past few decades, significant strides have been made in blood sugar tracking technology, which has improved in both accuracy as well as accessibility. Since the mid-1800s, scientists have attempted to quantify blood sugar levels using urine samples. Their efforts were finally met with success in 1908, and a published methodology quickly followed by use of a copper reagent, which oxidized glucose and allowed for tracking of blood sugar levels via color comparison in samples (Clarke et. al, 2012). By 1965, the first test strip had been developed, allowing for more specific, quantitative measurement of blood glucose levels (Hirsch, 2018). Within the next fifteen years, electric blood glucose monitors were being developed for wide-scale use, significantly increasing accessibility for diabetic patients. These self-monitoring glucose monitors allowed patients to measure glucose levels in their blood at any given time, allowing for the improvement of overall glycaemic control (Klimek et. al, 2019). Since this key development in glucose tracking technology, minor improvements continued to be made, including less blood required for each individual blood test. Over the past ten years, continuous glucose monitoring has been introduced to the general populace. This technology enables diabetic patients to monitor their blood sugar levels constantly, which has helped in identifying blood glucose patterns and trends and specifying consequent insulin injection time. The ease with which diabetic patients are now able to track blood glucose levels reflects the large improvements in glucose tracking technology, which have revolutionized the way diabetics live and manage their illness. Conclusion While it is clear that we have come a long way in assisting diabetic patients due to recent technological innovation, researchers, engineers, and clinicians are continuing to work towards creating a more effective, accurate, and accessible means of tracking blood glucose levels (Muegge et.
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J bacterial pathogens to protect human health. By looking beneath the waves, humans have derived bioinspiration from the ingenuity of nature and evolution in countless ways and innumerable instances.
ECOLOGY
Parrotfish
Oceanic Bioinspiration:
Parrotfish possess a set of remarkable teeth. Their continuously growing rows of teeth become cemented together and surrounded by a layer of bone to form a beaklike structure that has incredible strength and durability, enabling the unique feeding behaviors of these fish (Marcus et al., 2017; Roberts, 2017). As the beak of a parrotfish wears down, new rows of teeth fill in as replacements, becoming interconnected and fused into the composite beak (Marcus et al., 2017). Parrotfish feast on macroalgae, which beneficially reduces algal cover over the reef, meaning parrotfish are an integral part of a healthy reef ecosystem (Roberts, 2017). They will also take time for munching, crunching, and scraping the stony coral itself as they target corals polyps and symbionts for food, a task which requires very durable teeth and a strong bite (Marcus et al., 2017). Parrotfish grind coral fragments into a fine particulate matter, which eventually, after passing through the fish’s digestive tract, becomes sand (Marcus et al., 2017). Amazingly, a single parrotfish can produce hundreds of pounds of sand each year, contributing to the creation of many beaches (Marcus et al., 2017; Roberts, 2017). Researchers, including UW-Madison’s Dr. Gilbert of the biophysics department in collaboration with the Department of Energy’s Lawrence Berkeley National Laboratory, wanted to understand what about the teeth of parrotfish at the
Looking to the ingenuity of parrotfish, manta rays, sharks, and marbled electric rays By Leta Landucci
"The ocean hints at an immeasurable diversity of life."
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of time and the force of evolution as environmental conditions and selective pressures fluctuate. The forms of creatures with advantageous characteristics that improve their survival within a habitat niche embody thousands of years of evolution. In expanding our knowledge of ocean ecosystems and their biological marvels, we see that myriad organisms have evolved novel strategies and physiological mechanisms which humans may be able mimic to address some of the challenges we face. Biomimicry may be used to approach engineering dilemmas, design new synthetic materials, broach novel methods of renewable and sustainable energy generation, and even increase defenses against
Fig. 1. A magnificently colored parrotfish bearing an incredibly strong beak. "Heavybeak Parrotfish, initial phase - Chlorurus gibbus" by zsispeo is licensed under CC BY-NC-SA 2.0 nano- and microscale enables them to be so durable and resilient, enduring the substantial contact stress of breaking up coral (Marcus et al., 2017). Using X-ray imaging and visualization technologies, researchers found that parrotfish teeth possess a novel interwoven crystal structure of the biomineral fluorapatite (Marcus et al., 2017). Fluorapatite crystals contain calcium, fluorine, phosphorous, and oxygen constituents. These crystals are
Manta Ray The manta ray is the graceful giant of the world’s oceans – its wingspan can reach up to 29 feet (NOAA Fisheries, 2019). Despite their monolithic size, manta rays eat some of the smallest organisms found in the ocean, equipped with a specialized tool optimized for the task. Manta rays are filter feeders, which means they open their mouths wide as they swim and scoop up small organisms like zooplankton, mesoplankton, and microcrustaceans (NOAA Fisheries, 2019). With a mouth full of elaborately arranged gill plates, manta rays sift and collect their food particles while allowing water to exit and flow out through their gill slits (Raj et al., 2018). Manta rays possess an array of long lobes positioned within their mouths which bounce and ricochet food particles away from the filter, forcing the particles to instead accumulate within their mouth cavity to be swallowed and consumed, rather than gumming up the filter where the water is being expelled (Raj et al., 2018). This ricochet solid-fluid separation mechanism resists clogging and enables higher filtration flow rates, attributes that interest researchers who believe manta-inspired filters should be engineered to replace problematic filtration systems in industrial contexts and even wastewater treatment facilities (Raj et al,. 2018). Many current filter designs clog frequently as the particles they are intended to collect accumulate and block further filtration (Raj et al., 2018), but researchers think that Manta rays may hold the solution. Sharks Elasmobranchii, a subclass of cartilaginous fishes to which sharks belong, have existed for over 400 million years (Shiffman, 2019). They have survived numerous mass extinctions, some of which wiped out vast proportions of marine life, and have persisted to exist against tremendous odds (Shiffman, 2019). But it’s no small wonder how. Sharks have evolved unique immune systems and the ability to produce antiviral and antimicrobial compounds within the mucus coating of their skin that act to mount a defense
EDITORIAL
The ocean is vast, comprising 71% of the Earth’s surface, constituting a realm of underwater worlds, distinct ecosystems, and perplexing interactions hidden beneath the waves. The ocean hints at an immeasurable diversity of life, from creatures that swim in the open expansive blue, to those that flit among coral and sea fans, to others that hover between swaying fronds of sea grass and macroalgae. Some organisms reside in the depths where the stray photon hardly ever reaches, and other forms of life burrow hidden among ocean sands and debris. The morphological forms and behaviors distinct to each fish, coral, and crustacean arise from the culmination
able to twine together, assembling into interwoven bundles that confer incredible structural stability and strength to parrotfish teeth (Marcus et al., 2017). This study found that fluorapatite biominerals are “the stiffest, among the hardest, and the most resistant to fracture and to abrasion ever measured” and when tested, the hardness of parrotfish teeth at the biting surface is “about 530 tones of pressure per square inch – equivalent to a stack of about 88 African elephants – compressed to a square inch of space” (Marcus et al., 2017; Roberts, 2017). Researchers think the novel interwoven nanocrystal structure of parrotfish teeth could be as used as inspiration for the design of ultra-durable synthetic materials, for devices which are subjected to contact stress, repetitive movement, and abrasive forces (Marcus et al., 2017). Thanks to the parrotfish, we may be able to engineer synthetic materials resistant to degradation and wear for use in a wide array of applications.
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J against ocean pathogens (Dundar Arisoy et al., 2018; Marra et al., 2017). These compounds can also help facilitate rapid healing of tissue damage, with the aid of sharks’ highly specialized skin. Tiny overlapping diamond-shaped structures known as dermal denticles cover shark skin, and these denticles not only help the shark swim faster by reducing drag and increasing thrust, but they also play a part in defending against infection (Marra et al., 2017; Domel et al., 2018, Dundar Arisoy et al., 2018). The ridged geometry of shark skin denticles is thought to reduce the ability of bacterial microbes to grab hold and attach tightly, lessening the
chance of wound infection (Dundar Arisoy et al., 2018). Researchers at the University of Massachusetts-Amherst are interested in creating shark-skin-inspired surfaces to apply to high-touch objects, to see if these surfaces might stop bacteria from inhabiting them. They found that shark skin surfaces, printed from polymer and ceramic composite materials, and textured with denticle-mimicking structures and topologies can reduce microbial adhesion and colonization (Dundar Arisoy et al., 2018). These textured surfaces reduce E. Coli coverage by up to 55% while reducing the size of bacterial colonies by 76%, when compared with similarly composed yet smooth surfaces (Dundar Arisoy et al., 2018). To further improve the antimicrobial properties of these surfaces, researchers impregnated the biomimetic synthetic shark skin with titanium dioxide nanoparticles which reduced E. coli presence by 70% (Dundar Arisoy et al., 2018). The TiO2 particles absorb UV light and generate reactive hydroxyl radicals which destroy bacterial membranes (Dundar Arisoy et al., 2018). Exposing nanoparticle infused denticle-textured surfaces to UV light for one hour improved bacteria-fighting abilities even further, resulting in over 95% of E. coli and 80% of staphylococcus to be killed
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Marbled Electric Ray Marbled electric rays bear dark brown and black skin spots, ideal for camouflaging themselves as they burrow into the ocean sands and laying in wait for unsuspecting prey to pass overhead (Oceana). Unlike other rays, they do not possess venomous barbs, but rather have the ability to generate and discharge large amounts of electrical charge with a specialized electric organ (Oceana; Tanaka et al., 2016). Any prey unfortunate enough to swim by gets hit with a huge electrical shock from the upward surging ray, enough to stun and in many cases, put a very prompt end to the prey’s life (Oceana). Scientists from the RIKEN Quantitative Biology Center in Japan study the electric organ to learn about the mechanism by which marbled electric rays can generate such large quantities of electrical energy, up to 220 volts, directly from ATP, the biomolecule providing cells their main source of energy (Tanaka et al., 2016). The ray’s electric organ has densely layered membranes, much like an onion, but with many ion channels and ion pumps (Sperelakis, 2012; Tanaka et al., 2019). When the electric organ receives an acetylcholine neurotransmitter signal triggered by the brain’s decision to attack prey, many ion channels within the membrane, including those that are ATP-utilizing/hydrolyzing, open, facilitating the rapid influx, or movement of ions from the outside of the cell to the inside, generating an electric potential and large electrical current which can subsequently be used to shock the prey (Sperelakis, 2012; Tanaka et al., 2016). The RIKEN research group thinks that these concepts could be used to develop a high-efficiency power generator that’s environmentally friendly (Tanaka et al., 2016). By studying the ATP-based electricity producing capabilities of the electric organ, researchers may be able to create synthetic and artificial devices to mimic the ingenuity of the marbled electric ray in producing bioelectricity.
Science Advances, 4(9). doi:10.1126/sciadv.aat9533. Domel, A. G., Saadat, M., Weaver, J. C., Haj-Hariri, H., Bertoldi, K., & Lauder, G. V. (2018). Shark skin-inspired designs that improve aerodynamic performance. Journal of The Royal Society Interface, 15(139), 20170828. doi:10.1098/ rsif.2017.0828 Dundar Arisoy, F., Kolewe, K. W., Homyak, B., Kurtz, I. S., Schiffman, J. D., & Watkins, J. J. (2018). Bioinspired photocatalytic Shark-skin surfaces with antibacterial and ANTIFOULING activity via NANOIMPRINT LITHOGRAPHY. ACS Applied Materials & Interfaces, 10(23), 20055-20063. doi:10.1021/acsami.8b05066 Marcus, M. A., Amini, S., Stifler, C. A., Sun, C., Tamura, N., Bechtel, H. A., et al. (2017). Parrotfish teeth: Stiff Biominerals Whose Microstructure makes them Tough and Abrasion-Resistant to Bite stony corals. ACS Nano, 11(12), 11856-11865. doi:10.1021/acsnano.7b05044 Marra, N. J., Richards, V. P., Early, A., Bogdanowicz, S. M., Pavinski Bitar, P. D., Stanhope, M. J., & Shivji, M. S. (2017). Comparative transcriptomics of elasmobranchs and teleosts highlight important processes in adaptive immunity and regional endothermy. BMC Genomics, 18(1). doi:10.1186/s12864-016-3411-x
References: Divi, R. V., et al. (2018). Manta Rays Feed Using Ricochet Separation, a Novel Nonclogging Filtration Mechanism.
NOAA Fisheries, Giant Manta Ray. (2019, December 5). Retrieved from
https://www.fisheries.noaa.gov/species/giant-manta-ray Oceana, Marbled electric ray. (n.d.). Retrieved March 07, 2021, from https://oceana.org/marine-life/sharks-rays/marbled-electric-ray Roberts, G. (2017, November 15). X-rays reveal the biting truth about parrotfish teeth. Retrieved March 07, 2021, from https://newscenter.lbl.gov/2017/11/15/xrays-reveal-biting-truth-about-parrotfish-teeth/ Shiffman, D., & The Ocean Portal Team (2019, October 16). Sharks. Retrieved March 07, 2021, from https://ocean. si.edu/ocean-life/sharks-rays/sharks Sperelakis, N. (2012). Chapter 48: Electrocytes of Electric Fish. In Cell physiology source book: Essentials of membrane biophysics. Amsterdam: Academic Pr. Tanaka, Y., Funano, S., Nishizawa, Y., Kamamichi, N., Nishinaka, M., & Kitamori, T. (2016). An electric generator using living Torpedo electric organs controlled by Fluid pressure-based Alternative nervous systems. Scientific Reports, 6(1). doi:10.1038/srep25899
EDITORIAL
EDITORIAL
Fig. 2. Shark dermal denticles viewed through a scanning electron microscope. "File:Denticules cutanés du requin citron Negaprion brevirostris vus au microscope électronique à balayage.jpg" by Pascal Deynat/Odontobase is licensed under CC BY-SA 3.0
(Dundar Arisoy et al., 2018). The research group suggests that scaling up fabrication methods for increased production is feasible, particularly in a hospital context, where shark skin surfaces on doorknobs and hospital bed rails may reduce harmful bacterial populations that put immunocompromised patients at high risk of hospital-acquired infections (Dundar Arisoy et al., 2018).
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Reviving the American Chestnut:
How Gene Editing Can Bring Back an Iconic North American Tree By Lydia Larsen
"The story of North American forests has mainly been a story of devastation and loss."
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likely arrived in the late 1800s, and by 1940 the American chestnut was all but wiped out (Popkin, 2020). The Solution As disease claimed most of the American chestnuts in the early 1900s, the government tried to intervene and save the population. Initially they tried to cut away large swaths of chestnut trees in hopes of stopping the blight in its tracks, but it moved to new areas through animals, other plants, and wind. When it became clear that the American chestnut was doomed, scientists tried planting Chinese chestnuts, which are resistant to the blight, in their place but their shorter stature couldn’t compete with taller oaks and other large trees. Since then, scientists have periodically some tried to cross Chinese chestnuts with American chestnuts to produce a tree with positive traits from both species, but the efforts failed (Popkin, 2020).
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ant tree may be available on a large scale (Westbrook et al, 2020). With promising scientific results and a long timeline until transgenic chestnuts can become commercially available, the ultimate question now isn’t how we could genetically modify a near-extinct species to confer disease tolerance. The question is, should we? The longstanding
Fig. 1. American Chestnut Burs (Image by Foto-Rabe from Pixabay) arguments against genetically modified organisms (GMOs) are still being made here; namely, concerns about “superweeds,” harmful mutations, and industry interference. Interestingly, agricultural giants like Monsanto cannot patent this version of the transgenic chestnut because William Powell, one of the lead scientists who created the transgenic tree, already published it in scientific literature. Additionally, very little project funding comes from industry and all other monies come with “no strings attached,” as described by Powell (Popkin, 2020). The Revival The world the American chestnut left is very different than the one to which it may return. Coal mines have replaced the livestock farms that depended on the chestnut, and the lumber industry has moved on to different sources. Those living in the region that relied so heavily on the American chestnut likely have no recollection of the tree. Yet the transgenic American chestnut is a powerful tool and symbol in this vastly different world. With levels of atmospheric carbon at the highest point in human history, nothing can help more than a tree whose non-water weight is more than half carbon (Popkin, 2020). In this new world, the American chestnut will have its work cut out. References Popkin, G. (2020, April 30). Can Genetic Engineering Bring Back the American Chestnut? The New York Times. Retrieved March 31 from https://www.nytimes. com/2020/04/30/magazine/american-chestnut.html Westbrook, J. W., Holliday, J. A., Newhouse, A. E., & Powell, W. A. (2020). A plan to diversify a transgenic blight-tolerant American chestnut population using citizen science. PLANTS, PEOPLE, PLANET, 2(1), 84–95. https://doi. org/10.1002/ppp3.10061 Zhang, B., Oakes, A. D., Newhouse, A. E., Baier, K. M., Maynard, C. A., & Powell, W. A. (2013). A threshold level of oxalate oxidase transgene expression reduces Cryphonectria parasitica-induced necrosis in a transgenic American chestnut (Castanea dentata) leaf bioassay. Transgenic Research, 22(5), 973–982. https://doi.org/10.1007/s11248-013-9708-5
EDITORIAL
The Problem For the last two centuries, the story of North American forests has mainly been a story of devastation and loss. Since the arrival of Europeans, once great, majestic woodlands have been reduced to shells of their former selves. No loss is quite as acute as that of the American chestnut. Up until the early 1900s, the American chestnut reigned as king of the forest throughout the eastern United States, especially the Appalachians where billions of the trees took root. The tree was not only beautiful, but it also helped build and support important industries, from telephone poles and housing to livestock feed, and, of course, those that were roasted over an open fire. The chestnut’s supremacy was cut tragically short when a fungal blight, known as Cryphonectria parasitica, arrived through New York. The blight was first discovered in 1906, although it
The hope for resurrecting the American chestnut now lies in genetic engineering. In 2013, William Powell of the State University of New York published a study indicating that genetically modifying an American chestnut with a specific wheat gene confers resistance against the fungus. For C. parasitica to infect a chestnut tree’s tissue, it secretes a substance known as oxalic acid (OA). OA lowers the pH to a level that is toxic for the tree, but ideal for the fungus. The fungus spreads through the tree, eventually destroying enough tissue that nutrients and water cannot pass through. The parts of the tree above the infection die, but C. parasitica cannot infect the roots. This allows chestnuts to resprout shoots and keep the tree alive; but eventually, the fungus kills the shoots, also. Except for a few rare specimens, the fungus has reduced the once prolific American chestnut to a mere shrub. Powell and his collaborators inserted a gene known as oxo, which encodes an enzyme called oxalate oxidase (OxO), into a chestnut embryo using a bacterium engineered to insert a specified DNA sequence into plant cells. OxO catalyzes a reaction that degrades OA into carbon dioxide and hydrogen peroxide, both of which are not toxic to the tree. Oxo is found in many plants, but this project used the wheat version. The scientists found that when oxo was expressed above a certain threshold; that is, the gene produced enough protein to manage the OA from C. parasitica, the tree showed significant resistance to the fungus (Zhang et al, 2013). The Work Ahead While these developments are exciting, it will be a long time before anyone can plant a transgenic, or organism with DNA from an unrelated organism, American chestnut in their backyard. Regulatory compliance for transgenic plants, especially those designed to be released into the wild, is no small feat. Applications need to move through three separate federal agencies. Scientists submitted extensive data on the transgenic chestnut, including information regarding the rate of leaf decomposition and the tree’s effect on bees and tadpoles. It will be years before the different regulatory bodies decide whether approve this new version of the tree (Westbrook et al, 2020). In the meantime, research continues. At this time, all transgenic American chestnut trees come from one parent, which means there is a serious lack of genetic diversity that can lead to persistent harmful mutations and mortality. To solve this problem, transgenic chestnuts need to be crossed with chestnuts from the wild, or wild-type. To produce a genetically diverse, blight-resistant chestnut population, scientists plan to create different versions of the Oxo-modified chestnut and strategically cross them with wild-type American chestnuts to create enough genetically distinct trees (Westbrook et al, 2020). This crossing scheme is different than crossbreeding with Chinese chestnuts because oxo, and therefore blight resistance, is passed down to half of the offspring. Chinese chestnuts have multiple genes that confer blight resistance, seriously complicating any crossbreeding projects, although recently there has been moderate success on that front. Considering all the planting, crossing, propagation, and regulatory approvals for the transgenic American Chestnut, it will be about 20 years before the blight-toler-
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J brain to focus on one task for a prolonged period of time will yield the best result. But if multitasking decreases both efficiency and quality of work, why does it remain so popular? The reason that adults continue to multitask is not that it maximizes productivity nor because it enhances performance: it is because it feels good to multitask. Adults are more likely to multitask when there is an increase in cognitive needs. Naturally, when there are incoming due dates or work deadlines, it seems most efficient to simultaneously tackle as many tasks as possible. Alternatively, if the task at hand is unenjoyable, the seemingly obvious
PSYCHOLOGY
Figure 1: Multitasking reduces productivity by as much as 40 percent. Credit: Marvin Meyer (unsplash.com)
The Myth of Multitasking By Sarah Kamal
"Multitasking is a matter of perception. The definition of multitasking can vary between individuals."
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times for these activities. Nonetheless, since more than one task is being performed simultaneously, these are all examples of multitasking and they are all harmful to the brain. An overwhelming majority of adults have convinced themselves time and time again that they are fantastic multitaskers. The problem with this misconception is that the human brain cannot perform multiple tasks at once. Instead, focus rapidly switches between tasks, and neither task is completed successfully or efficiently. The limits of the human brain ultimately cause multitasking to decrease productivity by as much as forty percent (Multitasking Overloads the Brain, 2017). The reality is that allowing the
References “Frequent Multitaskers Are Bad at It: Can't Talk and Drive Well.” ScienceDaily, ScienceDaily, 23 Jan. 2013, www.sciencedaily.com/releases/2013/01/130123195101.htm. “Movie Research Results: Multitasking Overloads the Brain.” ScienceDaily, ScienceDaily, 25 Apr. 2017, www.sciencedaily.com/releases/2017/04/170425092429.htm. “Mutltitasking Hurts Performance but Makes You Feel Better.” ScienceDaily, ScienceDaily, 30 Apr. 2012, www.sciencedaily.com/releases/2012/04/120430124618.htm. Uncapher, Melina. “Media Multitasking and Memory: Differences in Working Memory and Long-Term Memory.” Psychonomic Bulletin & Review, U.S. National Library of Medicine, 2016, pubmed.ncbi.nlm.nih.gov/26223469/.
EDITORIAL
Multitasking is a matter of perception. The definition of multitasking can vary between individuals. Many people will agree that texting while driving is a dangerous example of multitasking. On the other hand, habitual examples of multitasking may be overlooked. For instance, many adults can relate to checking their email during a meeting, scrolling through social media while they are on a phone call, or listening to their new playlist while they study. These activities are second nature to many people, so they may not consider them to be multitasking. If anything, it may seem odd to allocate separate
solution would be to do something enjoyable at the same time, hence why many adults watch television or listen to music while they work. In either scenario, oftentimes emotional needs are met, and cognitive needs are not (Multitasking Hurts Performance, 2012). Although there may be a feeling of efficiency, it is exactly that- a feeling. At the cost of completing the task at hand efficiently, people prefer the emotional boost or feeling that they accomplished several tasks at once or completed the task in a more entertaining way. The misperception of emotional satisfaction for productivity is the main downfall of multitaskers. Multitasking does not improve productivity, but it is more stimulating, more entertaining, and more challenging. This explains why people that have trouble concentrating on a single task are more likely to multitask (Frequent Multitaskers, 2013). The inability to block out distractions causes people to simultaneously engage in other activities in order to keep themselves from getting bored. Moreover, frequent multitasking increases the overall distractibility of individuals (Uncapher, 2016). This creates a disastrous, perpetual cycle where people who are easily distracted are more likely to multitask, and frequent multitasking increases distractibility. Thus, the negative effects of multitasking accumulate in the long run; individuals multitask because they have trouble concentrating on one thing at a time, but this habit only worsens their ability to concentrate in the future.
In an era that is fast-paced and full of distractions, such as constant deadlines, approaching due dates, and looming responsibilities, it can be difficult to focus on one thing at a time. Especially under the guise of increased production and performance, it is easy to utilize multitasking and experience the illusion of efficiency. However, multitasking is proven to do the opposite; instead, it reduces productivity and increases distractibility. Thus, it is most beneficial to avoid the endless cycle and complete tasks individually.
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J charge, it would travel unhindered through the universe and would have no interaction with normal matter other than through the weak interaction, a force seen during the radioactive decay of certain elements. It was these ghostly characteristics of the neutrino that led Pauli to say “I
PHYSICS
Fig. 1. (Left) The central IceCube Lab located at the ice’s surface and responsible for analyzing data returned by the IceCube sensor array directly below. Credit: IceCube Collaboration Fig. 1. (Right)The IceCube and DeepCore detector arrays, consisting of over 5000 sensors, plunging down 2500 meters below the ice’s surface. Credit: IceCube Collaboration
UW IceCube Neutrino Observatory searches for answers to cosmological mysteries using a notoriously elusive particle By Tommy Gillis "Since its construction was finalized in 2010, it has yielded exciting discoveries for the world of physics."
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surface, as it would be enough to hide evidence of the sensors’ “particle prey.” The ambitious and dramatic venture to take research from the frozen streets of Madison, Wisconsin, to the frozen tundra of Antarctica was necessary to detect one of the most elusive particles in all of physics: the neutrino. During the first half of the 20th century, the physics world was entering a period of renaissance prompted by Einstein’s theories of Special and General Relativity and propagated by the new theory of Quantum Mechanics. It was during this renaissance period in 1930 that an Austrian physicist, Wolfgang Pauli, was the first to theorize a new particle called the neutrino. Pauli hypothesized that the neutrino would be an electrostatically neutral and incredibly small particle with a mass very close to zero (Jarlskog, 2018). He theorized that due to its size and neutral
EDITORIAL
With a name like “IceCube,” it may come as no surprise that the IceCube Neutrino Observatory is located in one of the coldest places on Earth: The South Pole. In December 2010, a coalition of institutions co-led by the University of Wisconsin-Madison finished construction on the world’s largest neutrino detector array, the IceCube Neutrino Observatory (Fig. 1). The observatory’s detector array is comprised of nearly 100 large cables, each cable composed of 60 sensors that plunge as low as 2,450 meters through the Antarctic ice. (Fig. 2) (IceCube, 2021). Drilling through the ice proved to be no easy task for the construction team, as each hole, on average, took 48 hours to drill and required the development of a 4.8 megawatt Enhanced Hot Water Drill. (IceCube, 2021). Buried deep below the ice, the highly sensitive sensors had to be isolated and protected from even the most minor interfering signals experienced at the
have done a terrible thing. I have postulated a particle that cannot be detected.” (Jarlskog, 2018) It wasn’t until decades later that the neutrino was finally detected, confirming the existence of Pauli’s “undetectable” particle. The neutrino’s aversion to interacting with matter outside of radioactive decay makes it an elusive and difficult particle to work with. Why then do observatories such as IceCube place such high importance on the detection of these “ghost” particles? Neutrinos are produced during several astronomical events, from the burning of our sun, to the collisions of distant galaxies, making them the most abundant particle in the universe. The same ghost-like tendencies that give physicists headaches attempting to detect them also make neutrinos an invaluable tool in detecting astronomical phenomena. Since neutrinos have virtually no interaction with matter, they travel through space unhindered and the information they carry about their origin is completely preserved, that is, until it arrives at one of IceCube’s neutrino detectors. In September 2017, the IceCube Neutrino Observatory showed off its ability to detect these elusive particles in a remarkable fashion. After detecting a large burst of high energy neutrinos, researchers at IceCube immediately contacted associates at other observatories, alerting them to observe the coordinates in the sky where they had detected this sudden burst of neutrinos (Aguilar Sanchez et al, 2018). Crosschecking the detection of these neutrinos with electromagnetic data obtained by other observatories, researchers at IceCube concluded the source of the neutrinos was a blazar, an active blackhole at the center of a galaxy 4.6 billion light years away, consuming the surrounding galactic matter near its center (Aguilar Sanchez et al, 2018). It had been proposed that violent galactic events like blazars would produce neutrinos during their intense blasts of energy. However, there had been no observation of neutrinos being produced by such events until the detection of these high energy particles by IceCube. IceCube’s detection of a new high energy neutrino source
has provided valuable data to help physicists understand the fundamental physics behind blazars and other similar active galactic nuclei. Their findings have also shed light on the breadth of events capable of producing high energy neutrinos. The detection of high energy neutrinos by IceCube in 2017 not only provided physicists with valuable data neutrino production and blazars, but it also served the purpose of being an impressive proof of concept for other endeavors which will use neutrino detection to explore the boundaries of science, notably in the hunt for notorious dark matter. Since it was first theorized in the early to mid-20th century, dark matter has eluded all attempts to detect it. The reason being that dark matter isn’t just dark, meaning it has no interaction with light whatsoever, but its only observed interaction with the universe is through gravity (Bertone & Hooper, 2018). The mystery of dark matter has become a major problem in astrophysics as astronomers estimate that around 27% of the observable universe consists of dark matter, based on their observations of galaxy rotations (Fermilab 2020). Researchers at IceCube aim to solve this mystery, and they’re doing it through what they do best: neutrino detection. In an ongoing project, researchers at IceCube are searching for neutrinos produced by dark matter near the core of our Milky Way Galaxy (Aguilar Sanchez et. al, 2017). The detection of neutrinos produced by dark matter here would be the first detection of dark matter, capping off an astronomical search over 80 years in the making. The IceCube Neutrino Observatory is a remarkable project due to its impressive engineering and the ambitious scope of its research. Since its construction was finalized in 2010, it has yielded exciting discoveries for the world of physics. However, its most exciting discoveries may be yet to come. References Aartsen, M., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., et al. (2018). Neutrino emission from the direction of the blazar TXS 0506+056 prior to THE ICECUBE-170922A ALERT. Science, 361(6398), 147151. doi:10.1126/science.aat2890 Aguilar Sanchez, J. A., Iovine, N., Tönnis, C., & Zornoza Gómez, J. D. (2017). Combined search for neutrinos from dark matter annihilation in the galactic center USING IceCube AND ANTARES. Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017). doi:10.22323/1.301.0911 Bertone, G., & Hooper, D. (2018). History of dark matter. Reviews of Modern Physics, 90(4). doi:10.1103/revmodphys.90.045002 Fermilab. (n.d.). Retrieved March 02, 2021, from https:// www.fnal.gov/pub/science/particle-physics/experiments/ neutrinos.html IceCube Collaboration. (2011, January 08). Gallery. Retrieved March 02, 2021, from https://icecube.wisc.edu/gallery/detector/ IceCube Collaboration. (n.d.). IceCube. Retrieved March 02, 2021, from https://icecube.wisc.edu/science/icecube/ Jarlskog, C. (2018). History of the Neutrino September 5-7, 2018 Paris, France. Retrieved March 02, 2021, from http:// neutrinohistory2018.in2p3.fr/programme.html JUST VOL VI // ISSUE II // SPRING 2021 35
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PIXELS
Flowers
where science and art collide
Plant
Growth on Tree at Lakeshore Path
Bee Mid Flight
PHOTO SUBMISSIONS
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Investigating the Neural and Behavioral Differences of Ratio Processing in Males and Females.............40 Whether or not a gap in mathematical performance exists between males and females is highly debated. Older research attributes performance differences to males having greater innate math abilities, while more modern research finds fewer differences and attributes those that do exist to social implications, specifically caused by gender stereotype threat. This investigation uses ratio processing task performance as an indicator of mathematical acuity in third and sixth graders to derive existing differences between genders at the behavioral and neural levels, as well as to examine the role of math anxiety in these results. In addition, the role of the distance effect is explored as a mediator of math anxiety between genders. Males and females were expected to present differing brain activation during ratio processing tasks and differing levels of math anxiety mediated by the distance effect. Results indicated no significant difference in performance between males and females but differing behavioral and neural characteristics during ratio processing. These differences and the extent to which the distance effect was present were found to have no correlation with math anxiety. Results support the Gender Similarities Hypothesis, but do not account for differing social implications introduced with age. Findings of this and other studies regarding gender stereotypes are important in understanding inequalities in the classroom in order to better promote equitable learning environments.
TNFα: A Potent Upregulator of CXCL2/3 in Human Endothelial Cells....................................................56
Cardiovascular disease (CVD) remains a persistent leading cause of death on a global scale. The complex etiology of CVD dictates special attention be paid to the molecular mechanisms underlying vascular function, particularly concerning the inner lining of cells, known as the endothelium, which is markedly impaired in CVD. Tumor Necrosis Factor-Alpha (TNFa) is a pro-inflammatory cytokine and a key regulator of endothelial function that is upregulated in CVD. Downstream targets of TNFa, CXCL2/3 are chemotactic cytokines primarily responsible for leukocyte recruitment during inflammation. Given their stimulatory activity in angiogenesis, the process of forming new blood vessels, we hypothesize CXCL2/3 critically regulate healthy endothelial cell function within the TNFa signaling pathway. Despite the general characterization of TNFa on CXC chemokine expression, many regulatory effects have not been confirmed in Human Umbilical Vein Endothelial Cells (HUVECs), a widely used model of endothelial cells and critical tool in CVD research. To investigate the roles of TNFa on CXCL2/3, we performed a time course- and dose-response study examining CXCL2/3 mRNA expression in HUVECs using RT-qPCR. We found TNFa time- and dose-dependently increased CXCL2/3 mRNA levels but appeared to weaken culture monolayers and cell viability, indicating CXCL2/3 may be crucial intermediary signaling molecules in TNFa's regulation of endothelial function. Our study effectively demonstrates TNFa is an upstream upregulator of CXCL2/3 in HUVECs, but further studies are necessary to examine the effects of CXC chemokines on endothelial cell functions.
Placenta Geometry in the 2nd Trimester Assessed with Magnetic Resonance Imaging........................50 The placenta is an organ that develops in the uterus during pregnancy and provides oxygen and nutrients to the growing fetus. Algorithms for a semi-automated workflow were implemented and MRI images of 62 healthy pregnant women at two time points of gestation, 14-16 and 20-22 weeks, were analyzed. Methodology was developed for the in vivo assessment of placental geometry to observe whether geometrical factors such as surface area, volume, and location can be used to determine fetal outcome. As expected, volume and surface area measurements varied substantially across subjects and increased in all except four pregnancies. Corresponding analysis was conducted on ultrasound images in a subset of 31 subjects at 14-16 weeks with modest agreement in measures of placenta volume and surface area. The purpose of this study is to research about placental geometry and its potential connection to fetal outcome.
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Investigating the Neural and Behavioral Differences of Ratio Processing in Males and Females Molly Pistono
ABSTRACT: Whether or not a gap in mathematical performance exists between males and females is highly debated. Older research attributes performance differences to males having greater innate math abilities, while more modern research finds fewer differences and attributes those that do exist to social implications, specifically caused by gender stereotype threat. This investigation uses ratio processing task performance as an indicator of mathematical acuity in third and sixth graders to derive existing differences between genders at the behavioral and neural levels, as well as to examine the role of math anxiety in these results. In addition, the role of the distance effect is explored as a mediator of math anxiety between genders. Males and females were expected to present differing brain activation during ratio processing tasks and differing levels of math anxiety mediated by the distance effect. Results indicated no significant difference in performance between males and females but differing behavioral and neural characteristics during ratio processing. These differences and the extent to which the distance effect was present were found to have no correlation with math anxiety. Results support the Gender Similarities Hypothesis, but do not account for differing social implications introduced with age. Findings of this and other studies regarding gender stereotypes are important in understanding inequalities in the classroom in order to better promote equitable learning environments.
INTRODUCTION:
Women used to predominantly take on housewife roles with social priorities while males participated in education that allowed them to pursue careers in the science and mathematical fields. Despite advancements, math and science are still male-dominated fields (Collins, Kenway, & McLeod, 2000). According to Richard Teese, males are more intent on developing human capital (i.e. intelligence, wealth, and labor skills) while females are more in-
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Math Anxiety Many deem math as difficult overall. For those with high math anxiety, mathematics tasks prove to be even more difficult, decreasing mathematics learning, mastery, and motivation in comparison to their low-anxiety counterparts and, not to advantage, invoking a tendency to avoid school coursework in math
The Brain Basis of Math The intraparietal sulcus (IPS) of the brain is the area associated with numerical cognition, showing a developmental trend from the right hemisphere to bilateral representation, possibly due to a developmental linkage of numerical processes to language (Butterworth & Walsh, 2011). The Approximate Number System (ANS) allows us to distinguish the size of quantities relative to one another via activation of regions in the horizontal intraparietal sulcus (HIPS), facilitating mathematical tasks (Sasanguie et al., 2012). Most theories about fraction learning, however, deem the ANS to be ill-suited for fraction learning and suggest alternatives. Our lab has argued that the Ratio Processing System (RPS), a brain system separate from the ANS, is sensitive to nonsymbolic ratios and thus better-suited to support fraction learning (Matthews, Lewis, & Hubbard, 2016). A study on undergraduates at UW-Madison on the RPS showed that participants with higher RPS acuity performed better on symbolic and higher-order math tasks, even when accounting for domain general cognitive abilities and ANS sensitivity, suggesting that individual differences in nonsymbolic task efficiency predict symbolic math abilities (Matthews, Lewis, & Hubbard, 2016). Study Format and Predictions In a study by Cambridge University, 1,757 students across varying primary and secondary schools in England were tested to determine prevalence of math anxiety among the student body, which was found to be at 11%, or approximately 193 students
(Devine et al., 2017). With such abundance of math anxiety in schools and potentially more, compounded with the knowledge of the negative influence of math anxiety on learning and career outcomes, it is important to understand the neural correlates of mathematical learning and the effects of such hindrances like math anxiety on them. This study specifically looks at the correlations between math anxiety and brain activation, further analyzing differences among males and females. Gender-specific behavioral and neural correlations with math anxiety and fraction task performance are important because, if prevalent, they reveal existing gender inequalities in the classroom. A multidisciplinary approach bridging cognitive neuroscience and education to act upon such issues is imperative to invoke change in real-life classroom settings (Ansari & Coch, 2006). This study analyzes how ratio processing differs between males and females at the behavioral and neural levels, and if math anxiety is associated with these differences. In order to investigate this, our participants completed a fraction competency task during an fMRI scan comparing both symbolic and nonsymbolic ratios (line ratios and numerical fractions); the mixed fraction comparison task (XFC). Additionally, participants completed the MARS-E assessment (Math Anxiety Rating Scale - Elementary) to find levels of math anxiety. It is expected that males and females will present different brain activation when comparing nonsymbolic and symbolic ratios. When comparing numbers, the “distance effect” causes numbers that are closer together in value to be more difficult to differentiate than numbers that are further apart, indicating access to a mental number line. The “size effect” denotes mental number line representations of larger numbers to be more vague than smaller numbers (Dehaene, 2007). Thus, it is additionally hypothesized that increasing math anxiety will be associated with the distance effect at both the neural and behavioral levels.
METHODS Participants Data from the LAMBDA study through the Educational Neuroscience Lab at UW-Madison was used. Data from thirty participants’ second year in the study, as 3rd and 6th graders, was used, as this set of participants had all completed a math anxiety survey, the MARS task, giving 30 total participants with 15 male and 15 female. Gender is represented as the self-reported gender identity of participants, as gender refers to socially constructed roles whereas sex refers to biological characteristics of a person (Delphy, 1993). There was no age difference between groups (equal amounts of 3rd and 6th graders in each). Participants received fraction instruction in JUST VOL VI // ISSUE II // SPRING 2021
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tent on developing social and cultural capital, stemming from predetermined societal gender roles that, despite deviance from very traditional standards, still exist in minute ways in modern settings (Teese, 1995). This is just one possible explanation for gender differences in academia but is important to note when analyzing the ways gender stereotypes impact learning. Delving deeper into gender and academic performance, a debate of older and modern literature exists in which early research tends to attribute differences to males being smarter, while more current research attributes differences to social implications. Despite the underrepresentation of females in math-related fields, modern research has shown that females have a similar aptitude for mathematics learning and achieve similar scores on standardized tests (Haynes, Mullins, & Stein, 2004). This idea supports the Gender Similarities Hypothesis, which states that males and females are more psychologically similar than they are different (Hyde, 2005). In a meta-analysis by Hyde, Fennema, and Lamon (1990), it was found that there was no difference in the solving of complex mathematical tasks between the genders in elementary and middle school, but a small difference favoring males emerged during high school and puberty. In older studies, males displayed superior performance on standardized tests in high school when compared to females (Meece et al., 1982). Differences in math achievement between males and females could be caused by a greater prevalence of math anxiety in females when compared to males. The theorized greater susceptibility of females to math anxiety is due to their aversion to high stakes testing and social comparison as a result of gender stereotyping (Geist, 2010).
and math-related careers (Ashcraft & Krause, 2007). Richardson and Suinn (1972) define math anxiety as “involving feelings of tension and anxiety that interfere with the manipulation of numbers and the solving of mathematical problems in a wide variety of ordinary life and academic situations”. Math achievement in individuals with high math anxiety tends to be a misrepresentation of their actual ability, as performance significantly drops in timed and high-stakes conditions, both in laboratory and in educational settings (Ashcraft & Moore, 2009). If women are more likely to exhibit math anxiety than men, they are potentially predisposed to the negative byproducts of math anxiety listed above (Betz, 1978). This is due to gender stereotype threat, in which females are stereotyped to have poorer academic performance due to their gender, which causes performance-inhibiting effects when they highly identify with the group to which the stereotype applies (Schmader, 2002). Since older studies from the 1970s and 1980s, major cultural shifts have occurred that warrant new analysis on gender and math performance (Hyde et al., 2008).
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J 3rd grade, so their familiarity with the tested subject eliminated a possible confounding variable. Additionally, participants attend various Madison-area schools, so differing instruction styles and methods could also serve as a confounding variable in the results of the data. Cross-format Fraction Comparison Task (XFC) Participants completed the cross-format fraction comparison task (XFC) while inside an fMRI scanner. Following, children underwent a practice version of the XFC to allow the child to understand the formatting of the assessment. As shown in Figure 1, three conditions were presented in both the slideshow and the practice on the computer screen in which two representations of ratios were depicted: fraction-fraction (two symbolic ratios), fraction-line (one symbolic and one nonsymbolic line ratio), or line-line (two nonsymbolic line ratios). Symbolic ratios were represented as numerical fractions, and nonsymbolic ratios were represented as two adjacent lines. All possible symbolic fractions were irreducible, single-digit fractions, with nonsymbolic ratios corresponding to the used symbolic representations. The task for the child was to select the larger ratio of the two options provided by choosing the ratio on the left by pressing the J key with their index finger, or the ratio on the right by pressing the K key with their middle finger, which was predetermined and the same for all participants. Accuracy values were reported as decimals (with 1.0 being 100% correct) for all three scenarios. XFC responses were trimmed by reaction time (RT). We analyzed XFC performance by mean accuracy and mean RT of correct trials.
Participants were given a MARS-E assessment, or the Mathematics Anxiety Rating Scale-Elementary Form, a questionnaire which asks 26 questions to assess nervousness in everyday situations involving math (MARS-E: Suinn et al., 1988). Subjects marked their answers on a five-point Likert Scale, ranging from 0 points (“Not Nervous At All”) to 5 points (“Very, Very Nervous”) with a total 130 possible points. Greater scores indicate higher levels of self-reported math anxiety. The MARS assessment is known to have high test-retest reliability, shown through average scores decreasing post-behavioral therapy, as well as high validity (Richardson & Suinn, 1972). fMRI
Participants completed the XFC tasks while in the GE MR750 fMRI scanner at UW-Madison’s Waisman Center. The scanner has a magnetic field strength of 3 Tesla, is equipped with 42 JUST VOL VI // ISSUE II // SPRING 2021
Data Analysis To compare self-reported math anxiety, accuracy, and RT in XFC as well as the beta weights by gender, Student’s t-test and Mixed ANOVAs were used for each of the three conditions (LL, FL, FF) and three distances (far, medium, near) both within the two groups (males and females) and between the two groups. We then investigated the association between MARS and beta-weights separately by gender to expose correlation between math anxiety and brain activation if present.
RESULTS: Behavioral First, the difference between groups in XFC was investigated at the behavioral level. Larger reaction times indicate a slower reaction time, while smaller reaction times indicate a faster reaction time. In XFC reaction time (RT) analysis (Table 2), females were found to have a mean RT of 1429.47 ms while males had a mean RT of 1479.04 ms (difference of 49.57 ms). A mixed ANOVA (Table 1) found a significant effect of Gender (faster RTs in females, F(1) = 25.168), p < .001, but no significant effect of XFC condition (LL, FL, FF), F(8) = 0.780, p = 0.62, or Sex x Gender interaction between groups depending on condition, F(8) = 1.042, p = 0.40. A scatter plot showing XFC Mean RTs (Fig. 3) dependent on distance (far, medium, or near) displays overall greater RTs in males for each XFC notation (FF, FL, LL), with a Line-Line < Line-Frac < Frac-Frac increasing RT trend present in both groups. A Far < Medium < Near increasing RT fMRI view trend is observed as well. A mixed ANOVA (Table 3) displays insignificant XFC Accuracy variation between and within groups, with F(1) = 0.003, p = .95 (sex), F(8) = 0.743, p = 0.65 (condition), and F(8) = 0.779, p = 0.62 (sex:condition).
Neuroimaging Next, the difference between groups in XFC was analyzed at the neural level, in first the right hemisphere of the brain followed by the left hemisphere. Beta weights for brain activation in the right hemisphere (RH) for females separated by task yielded mean beta weights of 635.07 for FF (p = 0.63), 542.98 for FL (p = 0.91), and 601.04 for LL (p = 0.79). For males, mean beta weights were 693.24 for FF (p = 0.39), 395.71 for FL (p = 0.29), and 543.97 for LL (0.92) for the right hemisphere. Figure 4 displays mean beta weights in the RH dependent on ratio value distance, task, and gender, with an increasing brain activation trend of FL<LL<FF in males and FL<LL<FF. A mixed ANOVA for beta weights in the RH (Table 4) found significant variance both within and between groups, with females displaying overall less brain activation than males (all p-values <.001). All possible combinations of ratio distance (far, medium, near) and XFC notation (FF, FL, LL) were investigated both between genders, and within genders through a post-hoc analysis for beta weights in the right hemisphere. All differences in brain activation both between and within groups were significant (all p < .001). Beta weights for brain activation in the left hemisphere (LH) for females separated by task yielded mean beta weights of 378.84 (p = 0.39) for FF (p = 0.24), 633.07 for FL (p = 0.64), and 442.90 for LL (p = 0.45). For males, mean beta weights were 467.84 for FF (p = 0.56), 441.79 for FL (p = 0.45), and 361.65 for LL (0.19) for the left hemisphere. Figure 6 displays mean beta weights in the LH dependent on XFC notation, task, and gender, with an increasing brain activation trend of LL<FL<FF in males and FF<LL<FL in females. A mixed ANOVA for beta weights in the RH (Table 5) found significant variance both within and between groups, with females displaying overall less brain activation than males (all p-values <.001). All possible combinations of ratio distance (far, medium, near) and XFC notation (FF, FL, LL) were investigated both between genders, and within genders through a post-hoc analysis for beta weights in the left hemisphere. All differences in brain activation both between and within groups were significant (all p < .001). This post-hoc analysis as well as the post-hoc analysis for the right hemisphere ensures that the found differences in brain activation account for all possible combinations of conditions both between and within groups. The significance of the post-hoc results deems the finding of males having overall greater brain activation than females to be significant. Behavioral: Math Anxiety
Besides looking at the difference between gen-
ders in XFC at the behavioral and neural levels, we also investigated how math anxiety was associated with XFC performance for each gender. Mean reaction times were calculated for each distance, and then mean RTs for far were subtracted from near as a simplified representation of the distance effect, which was called deltaRT. Larger numbers indicate that participants were slower in the near distance than the far distance, and smaller numbers indicate similar RTs for both distances. As depicted in Figure 6, when tested for correlation between XFC deltaRTs with MARS scores dependent on gender, no significant correlation was found for the Fraction-Fraction XFC task in males (r = -0.17, p = 0.54) or females (r = -0.24, p = 0.38). Shown in Figure 7, no significant correlation between math anxiety and deltaRT values was found for the Fraction-Line XFC task in males (r = 0.20, p = 0.47) or females (r = 0.39, p = 0.14). Shown in Figure 8, no significant correlation between math anxiety and deltaRT was found for the Line-Line XFC task in males (r = -0.39, p = 0.23) or females (r = 0.14, p = 0.61). Neuroimaging: Math Anxiety Mean beta weights were derived for each distance, and then mean beta weights for far were subtracted from near as a simplified representation of the distance effect (larger numbers indicate greater distance effect). When analyzing for correlation between brain activation and math anxiety for each XFC task, no correlation was found in any task for either gender. In Figure 9, no significant correlation was found in the left hemisphere for the FF task for females (p=.18) or males (p=.36). In the right hemisphere (Fig. 10), no significant correlation was found for the FF task for males (p=.86) or females (p=.76). Shown in Figures 11 and 12, no significant correlation was found in the right hemisphere for males (p=.30) or females (p=.61) or the left hemisphere for males (p=.18) or females (p=.96) for the FL task. For the LL task (Fig. 13 & Fig. 14), no significant correlation was found in the right hemisphere for males (p=.67) or females (p=.42) or the left hemisphere for males (p=.90) or females (p=.38).
DISCUSSION: Initially, it was hypothesized that males and females would present different performance and brain activation in ratio processing. After behavioral analysis, it was derived that females had significantly overall faster reaction times than males (Fig. 4). Looking at beta weights as representation of brain activation during XFC tasks, it was found that males had significantly overall greater brain activation when compared to females (Fig. 5 & Fig. 6), which makes sense as faster RTs are generally associated with lower beta weights (less activation). However, no significant difference in XFC task performance was found between genders (Table 3). JUST VOL VI // ISSUE II // SPRING 2021 43
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fast water-cooled gradients (slew rate of 200mT/ms, peak amplitude 50mT/m, 100% duty cycle), and has 32 receive channels for improved multi-coil signal detection. The neuroimaging software pack BrainVoyager QX was used to run multi-modal analysis for the collected fMRI data, as well as to extract beta weight values, which are units of standardized scores in regression (Fig. 2). Greater beta weights represented greater brain activation. A previous meta-analysis of brain imaging studies of math (Houde et al., 2010) was used to identify the coordinates of the region of interest (functional ROI) as a set of voxels responsive to task. The intraparietal sulcus (IPS) was used as the ROI in both hemispheres as this area of the brain is associated with mathematical achievement and reasoning bilaterally (Butterworth and Walsh, 2011).
J The data for females appeared somewhat skewed with less obvious trends than those found in males. This could be attributed to the small sample size used (15 boys and 15 girls), with any extreme outlier values potentially skewing the data with a greater effect than they would in a larger sample size. Considering differing brain activation levels between genders, specifically reported in Figures 5 and 6, it is possible that this is due to developmental differences between males and females. A difference in average brain size exists with females on average developing smaller brains due to smaller body size (Rushton & Ankney, 2009). However, all of the brains were normalized to a common template space, accounting for these differences in head and brain size. When differences in body size are accounted for, there is no difference in the relative brain size, so no definitive claims can be made about differing brain activations between males and females. Based on found differences in brain activation and reaction time in between groups, we analyzed further to see if they were correlated with math anxiety, particularly looking at the distance effect. In analyses of reaction times (Fig. 7-9) and beta weights (Fig. 10-15), no significant correlation was found for either. It was hypothesized that increasing math anxiety would be associated with the distance effect at neural and behavioral levels, but null results were found for both. Thus, the distance effect was not shown to be mediated by math anxiety. It has been found that the magnitude of the distance effect decreases with increasing age because of increasing familiarity in math (Duncan & McFarland, 1980). It is possible that it would be more likely to see the distance effect be correlated with increasing math anxiety at a greater age, as its effect is less over time in regular individuals. Therefore, behavioral and neural differences that were found between genders cannot be attributed to math anxiety. Overall, the results support the Gender Similarities Hypothesis in that males and females have the same capacity to learn math (Hyde, 2005). This goes against older research that suggested that males have inherently better academic capabilities and that gender differences in academic performance, if found, are attributed to innate ability, not outside factors. This study, as well as findings in modern literature mentioned previously, could be credited to decreasing gender stereotypes and decreasing stereotype threat. Stereotype threat is due to association with the group to which the stereotype is attached, and in modern society, gender is becoming more “fluid”, as more variance is seen in gender identities. Gender inequalities in the classroom could be decreasing in this way. In future studies, the use of a larger sample size from which data is extracted would be ideal in order to reduce outliers and get more coherent data. Furthermore, an older subject group of high school-aged participants could reveal different in-
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formation. In a study by Muzzatti and Agnoli (2007), when elementary-aged girls were told that “extraordinary achievement in mathematics is typically a male phenomenon”, a decrement was found in their math performance. Carrying into middle school, more detrimental effects were found in math performance of females as a result of these stereotypes consolidating poorer performance patterns in females. This suggests that until gender stereotypes are introduced, their harmful effects will not be as evident. It is possible that divergence in performance as a result of gender stereotype threat would not occur until adolescence, as this period is when social comparison and peer influence is more prevalent (Brown et al., 2008). A longitudinal study done from initial fraction instruction through adolescence could reveal, if these effects do not have an impact until later, how math performance and brain activity changes with introduction of new social implications. Furthermore, new findings could be compared for correlation with math anxiety. All in all, it is important to find inequalities in the classroom, whether that be with gender, race, socioeconomic status, among other things, to ensure accurate representations of academic achievement and abilities and equal opportunities for all students.
ACKNOWLEDGMENTS: Molly would like to thank Professor Edward Hubbard and Ph.D. student Isabella Starling-Alves for providing feedback for this paper, as well as Lab Manager Ashley Ezpeleta.
REFERENCES: Ashcraft, M. H., & Moore, A. M. (2009). Mathematics anxiety and the affective drop in performance. Journal of Psychoeducational assessment, 27(3), 197-205. Ashcraft, M. H., & Krause, J. A. (2007). Working memory, math performance, and math anxiety. Psychonomic bulletin & review, 14(2), 243-248. Betz, N. E. (1978). Prevalence, distribution, and correlates of math anxiety in college students. Journal of counseling psychology, 25(5), 441. Binzak, J. V., Park, Y., Toomarian, E. Y., Kalra, P., Chuang, Y. S., Matthews, P. G., & Hubbard, E. M. Are Fractions Percepts? Neurocognitive Relationships between Nonsymbolic and Symbolic Ratio Processing in Children and Adults. BrainVoyager. (n.d.). Retrieved from https://www.brainvoyager.com/products/brainvoyager.html Brown, B. B., Bakken, J. P., Ameringer, S. W., & Mahon, S. D. (2008). A comprehensive conceptualization of the peer influence process in adolescence. Understanding peer influence in children and adolescents, 17-44. Butterworth, B., & Walsh, V. (2011). Neural basis of mathematical cognition. Current biology, 21(16), R618-R621. Collins, C. W., McLeod, J., & Kenway, J. (2000). Factors influencing the educational performance of males and females in school and their initial destinations after leaving school. Canberra: Department of Education, Training and Youth Affairs. Dietrich, J. F., Huber, S., Moeller, K., & Klein, E. (2015). The influence of math anxiety on symbolic and non-symbolic magnitude processing. Frontiers in psychology, 6, 1621. Dehaene, S. (2011, 1997). The number sense: How the mind creates mathematics. OUP USA. Delphy, C. (1993, January). Rethinking sex and gender. In Women's Studies International Forum (Vol. 16, No. 1, pp. 1-9). Pergamon. Devine, A., Hill, F., Carey, E., & Szűcs, D. (2018). Cognitive and emotional math problems largely dissociate: Prevalence of developmental dyscalculia and mathematics anxiety. Journal of Educational Psychology, 110(3), 431. Duncan, E. M., & McFarland, C. E. (1980). Isolating the effects of symbolic distance, and semantic congruity in comparative judgments: An additive-factors analysis. Memory & Cognition, 8(6), 612-622. Geist, E. (2010). The anti-anxiety curriculum: Combating math anxiety in the classroom. Journal of Instructional Psychology, 37(1). Haynes, A. F., Mullins, A. G., & Stein, B. S. (2004). Differential models for math anxiety in male and female college students. Sociological Spectrum, 24(3), 295-318. Houdé, O., Rossi, S., Lubin, A., & Joliot, M. (2010). Mapping numerical processing, reading, and executive functions in the developing brain: an fMRI meta‐analysis of 52 studies including 842 children.
Developmental science, 13(6), 876-885. Hyde, J. S. (2005). The gender similarities hypothesis. American psychologist, 60(6), 581. Hyde, J. S., Fennema, E., & Lamon, S. J. (1990). Gender differences in mathematics performance: a meta-analysis. Psychological bulletin, 107(2), 139. Hyde, J. S., Lindberg, S. M., Linn, M. C., Ellis, A. B., & Williams, C. C. (2008). Gender similarities characterize math performance. Science, 321(5888), 494495. Matthews, P. G., Lewis, M. R., & Hubbard, E. M. (2016). Individual differences in nonsymbolic ratio processing predict symbolic math performance. Psychological science, 27(2), 191-202. Meece, J. L., Parsons, J. E., Kaczala, C. M., & Goff, S. B. (1982). Sex differences in math achievement: Toward a model of academic choice. Psychological Bulletin, 91(2), 324. Muzzatti, B., & Agnoli, F. (2007). Gender and mathematics: Attitudes and stereotype threat susceptibility in Italian children. Developmental psychology, 43(3), 747. Richardson, F. C., & Suinn, R. M. (1972). The mathematics anxiety rating scale: psychometric data. Journal of counseling Psychology, 19(6), 551. Rushton, J. P., & Ankney, C. D. (2009). Whole brain size and general mental ability: a review. International Journal of Neuroscience, 119(5), 692-732. Sasanguie, D., Göbel, S. M., Moll, K., Smets, K., & Reynvoet, B. (2013). Approximate number sense, symbolic number processing, or number–space mappings: What underlies mathematics achievement?. Journal of experimental child psychology, 114(3), 418-431. Schmader, T. (2002). Gender identification moderates stereotype threat effects on women's math performance. Journal of Experimental Social Psychology, 38(2), 194-201. Suinn, R. M., Taylor, S., & Edwards, R. W. (1988). Suinn mathematics anxiety rating scale for elementary school students (MARS-E): Psychometric and normative data. Educational and Psychological Measurement, 48(4), 979-986. Teese, R. (1995). Gender equity in higher level mathematics: a study of regional socioeconomic influences on participation and attainment. Unicorn (Carlton, Vic), 21(4), 48.
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ods were used to track longitudinal changes in placenta volume and surface area throughout the 2nd trimester and placenta volume measurements were compared with ultrasound measures.
the portion of the placenta in the eight quadrants of this space was calculated. Statistical Analysis In a subgroup of 31 subjects, placenta volume measurements were also conducted with the same workflow applied to ultrasound images acquired at 14-16 weeks. No such comparison could be performed at 20-22 weeks of gestation because the placenta was too large to be captured for such measures with ultrasound. MRI and Ultrasound volume measurements were compared using the Bland-Altman method. This method is based on the quantification of the agreement between two quantitative measurements by studying the mean difference and constructing limits of agreement.4 Two-tailed paired sample t-tests were also used to compare MRI and ultrasound-based volume measurements, with a significance level of 0.05.
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RESULTS:
Image acquisition and segmentation Sixty-two healthy pregnant women were scanned at 2 time points: (1) 14-16 and (2) 20-22 gestational weeks using a 1.5T wide-bore clinical MRI scanner (MR450W, GE Healthcare, Waukesha, WI). Images were acquired with a 2D multi-slice single shot fast spin echo (SSFSE) method that covered the whole placenta with typical imaging parameters of: field of view=38x38 cm2, spatial resolution=1.43x1.43 mm2, slice thickness=5mm, 45 slices, repetition time=4s, echo time=100ms. Volume measurements were assessed by segmenting the placenta and uterus using a semi-automated software package (Fig. 1) with multi-planar reformatting capabilities (Mimics Innovation Suite 22, Materialize, Leuven, Belgium). The semi-automatic segmentation process of the placenta consisted of thresholding, region growing on manually placed seed points, and then manually adjusting the segmentation to cover the placenta and avoid uterine wall tissue (Fig. 2). Segmentation of the uterus followed a similar approach.
Average MRI-derived placental volume was 144 ± 66 mL at 14-16 weeks and 274 ± 80mL a 20-22 weeks (P<0.001; Pearson correlation coefficient [r] = 0.27; Figure 2). Average surface area was 240 ± 69cm2 at 14-16 weeks and 420 ± 101 cm2 at 20-22 weeks (P<0.001; r=0.28; Fig. 2 3). While the volume and surface area measurements varied substantially across subjects, they increased in all subjects except for four. The correlation coefficient for comparing average placental volume of MRI vs Ultrasound was 0.07. Compared with ultrasound, MRI underestimated the placenta volume by an average of 39% of the mean volume on ultrasound (P=0.008; Figure 4).
Placenta Geometry in the 2nd Trimester Assessed with Magnetic Resonance Imaging Archana Dhyani ABSTRACT:
The placenta is an organ that develops in the uterus during pregnancy and provides oxygen and nutrients to the growing fetus. Algorithms for a semi-automated workflow were implemented and MRI images of 62 healthy pregnant women at two time points of gestation, 14-16 and 20-22 weeks, were analyzed. Methodology was developed for the in vivo assessment of placental geometry to observe whether geometrical factors such as surface area, volume, and location can be used to determine fetal outcome. As expected, volume and surface area measurements varied substantially across subjects and increased in all except four pregnancies. Corresponding analysis was conducted on ultrasound images in a subset of 31 subjects at 14-16 weeks with modest agreement in measures of placenta volume and surface area. The purpose of this study is to research about placental geometry and its potential connection to fetal outcome.
The placenta is a fetal organ that develops in the uterus during pregnancy and is essential in providing oxygen and nutrients to the growing fetus via the umbilical cord. Poor placental function may lead to preterm labor, late spontaneous abortion, abruption placentae, and fetal growth restriction (Hashem, 2016). A study by Panti et al (2012), states that a healthy placenta is a useful marker for fetal nutrition, fetal weight, and utero-placental function. Hence, robust measures of placenta geometry may be valuable in normalizing functional parameters such as total uterine blood flow, perfusion, and oxygenation and might be indicative of birth weights and pregnancy outcomes (Ray, 2016). Traditional in vivo assessment of placenta geometry uses ultrasound imaging. Magnetic resonance imaging (MRI) is a compelling alternative: MRI is safe in pregnancy (Yang, 2017), has only minimal geometric distortions, consistent spatial resolution, increased placenta-to-uterus contrast, and large coverage for accurately assessing placental geometry, anatomy, and function. In this work, we developed methodology for the in vivo assessment of placental volume, surface area, and location in respect to the uterus to determine if they had any correlation to fetal outcome. These meth-
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Computation of placenta volume, surface area, and location Placenta volume was computed directly within Mimics by summing the volumes of all placenta mask voxels. Placenta surface area and geometry were computed in custom MATLAB scripts (2019, Mathworks, Natick, MA). Surface area was computed by converting the 3-dimensional point cloud into a triangular surface mesh, smoothing the surface mesh, and finally summing the areas of all surface triangles. The placental geometry algorithm took as inputs the uterus and placenta segmentations, and automatically determined the implantation site of the placenta in respect to the uterus, which was highly variable among subjects and might impact placental perfusion. This was accomplished in the experiment by establishing a coordinate system with its origin in the center of the uterus and axes along the right-left, anterior-posterior, and inferior-superior directions. Then
ACKNOWLEDGMENTS: The authors thank the NIH Human Placenta Project (NICHD U01HD087216), NIH award TL1TR002375, and GE Healthcare for research support. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
DISCUSSION: The volume and surface area measurements varied substantially across individuals. These measurements increased between the two sampled time points in gestation in all subjects except for four cases. Placental volume as measured by ultrasound was higher on average than the corresponding placental volume measured by MRI and the correlation between the two imaging methods was low, perhaps due to the coarse through-plane resolution of MRI images or geometrical distortions of ultrasound images. Placental location was successfully assessed in all 62 cases and will be correlated with outcomes in future work.
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ial, and coronal) than MRI thus allowing us more surface area to segment. In future studies, we seek to correlate these measures with birth weights and pregnancy outcomes and to investigate their predictive value and further investigate the sources of variances between the imaging techniques. We also plan to extend the analysis to additional geometry factors such as placental thickness, area of the uterine-placental interface, and uterine volume.
We implemented a workflow and algorithms for the semi-automated assessment of placental volume, surface area, and implantation site within the uterus for ultrasound and MRI data. Placental volume was found slightly higher on ultrasound than MRI and, as expected, increased within the 2nd trimester of gestation. We believe this is because ultrasound can better achieve a circular view of the placenta (all three views: sagittal, ax-
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Hashem A. L., Salem D. S., Hamed, S. T., & Hussein A. M. (2016). Role of MRI versus ultrasound in the assessment of placental abnormalities and diseases. Indian Journal of Radiology and Imaging. 47(2), 641-658. doi:10.1016/j.ejrnm.2016.02.006 Panti A., Ekele, B. A., Nwobodo, E., & Yakubu, A. (2012). The relationship between the weight of the placentae and birth weight of the neonate in a Nigerian Hospital, Nigerian Medical Journal. 53(2), 80-84, doi: 10.4103/0300-1652.103547 Ray J. G., Vermeulen, M. J., & Bharatha, A. (2016). Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes. JAMA. 316(9), 952-961, doi:10.1001/jama.2016.12126. Yang J., Wang, Y., Wang, X., Zhao, Y., Wang, J., & Zhao, Y. (2017). Adverse Pregnancy Outcomes of Patients with History of First-Trimester Recurrent Spontaenous Abortion, BioMed Research International. doi: 10.1155/2017/4359424
Fig. 1: A representative single 2D SSFSE image without (a) and with (b) overlay (green) of the placenta segmentation results as well as reformatted views of the segmented placental volumes in orthogonal orientations (c-e).
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Fig. 2 and 3: MRI surface area and volume measurements at 14 and 20 weeks collected from 14 and 20-week scans Fig. 4: Bland-Altman analysis of placental volumes measured using MRI and Ultrasound.
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TNFα: A Potent Upregulator of CXCL2/3 in Human Endothelial Cells Colman I. Freel1, Alexander R. Uy1, Ying-jie Zhao1, Chi Zhou2, Jing Zheng1 1Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin—Madison, Madison, Wisconsin, United States 2Department of Obstetrics and Gynecology, College of Medicine, University of Arizona—Tucson, Tucson, Arizona, United States
ABSTRACT: Cardiovascular disease (CVD) remains a persistent leading cause of death on a global scale. The complex etiology of CVD dictates special attention be paid to the molecular mechanisms underlying vascular function, particularly concerning the inner lining of cells, known as the endothelium, which is markedly impaired in CVD. Tumor Necrosis Factor-Alpha (TNFa) is a pro-inflammatory cytokine and a key regulator of endothelial function that is upregulated in CVD. Downstream targets of TNFa, CXCL2/3 are chemotactic cytokines primarily responsible for leukocyte recruitment during inflammation. Given their stimulatory activity in angiogenesis, the process of forming new blood vessels, we hypothesize CXCL2/3 critically regulate healthy endothelial cell function within the TNFa signaling pathway. Despite the general characterization of TNFa on CXC chemokine expression, many regulatory effects have not been confirmed in Human Umbilical Vein Endothelial Cells (HUVECs), a widely used model of endothelial cells and critical tool in CVD research. To investigate the roles of TNFa on CXCL2/3, we performed a time course- and dose-response study examining CXCL2/3 mRNA expression in HUVECs using RT-qPCR. We found TNFa time- and dose-dependently increased CXCL2/3 mRNA levels but appeared to weaken culture monolayers and cell viability, indicating CXCL2/3 may be crucial intermediary signaling molecules in TNFa's regulation of endothelial function. Our study effectively demonstrates TNFa is an upstream upregulator of CXCL2/3 in HUVECs, but further studies are necessary to examine the effects of CXC chemokines on endothelial cell functions.
Since 2001, the World Health Organization has recognized cardiovascular disease (CVD) as the leading cause of death globally (Cardiovascular Diseases, 2017). With 17.9 million CVD-related deaths in 2016, averaging 31% of all deaths worldwide, CVD's impact on global health is indisputable (Cardiovascular Diseases, 2017). The complex etiology of CVD makes understanding the molecular mechanisms underlying CVD manifestations crucial to finding treatments and preventative measures. One of the main features of CVD is impaired vascular
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Tissue Collection and Cell Line Purification Umbilical cords were collected in accordance with protocols approved by the Institutional Review Boards of Meriter Hospital and the University of Wisconsin-Madison Health Sciences. Meriter Hospital Birth Center obstetricians provided a diagnosis of preeclampsia or normotension. Only normotensive -HUVECs (NT-HUVECs) were used in this study. HUVECs were isolated from umbilical cords immediately after collection and purified after 16 hours of culture as described by Zhou et al. (2017). Cells were cultured in Corning T-75 cell culture flasks (cat: 430641U) containing endothelial culture media (ECM) with 1% penicillin/streptomycin, 5% fetal bovine serum, and 1% endothelial cell growth serum. Individual NT-HUVEC preparations at passage four (P4) were pooled, suspended in a 9:1 ECM-DMSO cocktail, and frozen in liquid nitrogen until experimentation. TNFa Time- and Dose-Response Pooled P4 NT-HUVECs were recovered from liquid nitrogen and seeded in a T-75 cell culture flask with ECM. At confluence, HUVECs were divided into a Falcon 12well plate (cat: 353043) and cultured overnight in ECM. After 12 hours of culture, HUVECs were starved in serum-free ECM (ECMb) for 8 hours. Media was removed, and HUVECs were treated with either ECMb (control), ECMb with 1, 10, or 100 ng/mL recombinant TNFa, for 24 and 48 hours. Wells were imaged once using a Nikon TE2000-U fluorescence microscope after their respective treatments. After treatment, cells were harvested and lysed. RNA Extraction and cDNA Synthesis RNA Extraction and cDNA Synthesis procedures were performed as previously described (Zhou et al., 2017). In brief, HUVEC lysates were homogenized using a Qiagen QIAshredder kit, and total RNA was isolated using a Qiagen miRNeasy Mini Kit. RNA quality and concentration were assessed using a NanoDrop ND-2000 spectrophotometer. Reverse transcription was performed using a Qiagen QuantiTect Reverse Transcription Kit and Applied Biosystems SimpliAmp Thermal Cycler. Gene Expression Analysis Real-time quantitative PCR (RT-qPCR) analysis of CXCL2 and CXCL3 mRNA expression was performed using 96-well qPCR plates (Applied Biosystems, cat: 4346907) and a StepOnePlus RT-qPCR system (ThermoFisher). YWHAZ, ACTB, and GAPDH were used as housekeeping genes due to their relative abundance and stability in HUVECs. TaqMan master mix and primers for CXCL2/3 and housekeeping genes were purchased from ThermoFisher (Table 1). We performed three technical replicates for each treatment-gene combination. RT-qPCR data were analyzed using the 2-∆∆CT method to assess gene expression (expressed as fold of control).
RESULTS:
Our results show that TNFα is an upstream upregulator of CXCL2/3, and there are cell functional effects associated with TNFa treatment. Our RT-qPCR data have shown that TNFa substantially upregulated CXCL2 and CXCL3 mRNA expression in HUVECs compared to control (Fig. 1). Specifically, at 24 hours of treatment, TNFa time- and dose-dependently increased the expression of CXCL2/3 mRNA levels, with maximum effects observed at 24 hours with 100ng/mL of TNFa. At high doses of TNFa and prolonged treatment durations, HUVECs had diminished cell viability and overall weaker monolayers (Fig. 2). Noticeable cell monolayer patches were present in HUVECs treated with 100ng/mL TNFa for 24 hours and 1ng/mL, 10ng/mL, and 100ng/mL TNFa for 48 hours. Suspended cell debris in HUVEC cultures treated with TNFa suggested cell death, and the concentration of debris appeared highest in HUVECs treated with TNFa for 48 hours.
DISCUSSION: To better understand the molecular mechanisms underlying endothelial dysfunction in CVD, we sought to characterize the role of TNFa in recruiting other inflammatory cytokines, specifically CXCL2/3. The observed positive correlation between TNFa dosage and CXCL2/3 mRNA expression demonstrates that TNFa is an upstream regulator of CXCL2 and CXCL3 in HUVECs, consistent with reports in other cell lines, tissues, and organisms. (Lo et al., 2014; Pappa et al., 2011) Our results show that TNFa-induced CXCL2/3 upregulation is dose-dependent, with higher doses of TNFa having a greater impact on CXCL2/3 mRNA expression. We observed a substantial upregulation of CXCL2/3 at 24 hours in all TNFa treatments with a marked decline in expression at 48 hours. While CXCL2 and CXCL3 exhibited similar responses to TNFa, a notable difference was the more drastic fold changes in CXCL3 compared to CXCL2. With a fold change greater than four times that of CXCL2 when treated with 100ng/mL TNFa, it appears CXCL3 has far greater sensitivity to TNFa than CXCL2. Differences in mRNA upregulation also indicate TNFa differentially dysregulates CXC chemokines and may even have downregulatory effects on chemokines within the same family. Based on cell images taken during TNFa treatment, it appears that TNFa has a noticeable negative effect on culture monolayer and HUVEC viability. HUVECs exposed to TNFa had more patches within the monolayer and accumulated more cell debris than control. Notably, HUVEC cultures treated with higher doses of TNFa and for longer durations (100ng/mL for 48 hours) appeared significantly weaker than those with much smaller doses treated for shorter durations (1ng/mL for 24 hours). While our single images are not sufficient for quantitative analysis, we hypothesize that TNFa dose and treatment time are negatively correlated with cell viability and monolayer integrity, given the observed decline in confluency in our TNFa treated cultures. Because we studied pooled HUVECs instead of in-
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endothelial function (Godo & Shimokawa, 2017). The endothelium is the single layer of cells that line human vasculature. A key function of the vascular endothelium is to allow for optimal transport of nutrients to tissues (Reiterer & Branco, 2020). CVD causes blood vessel constriction, clotting, and most importantly, inflammation of the endothelium, severely inhibiting nutrient exchange capacity (Godo & Shimokawa, 2017). Pro-inflammatory cytokines, notably Tumor Necrosis Factor-Alpha (TNFa), have been implicated in vascular endothelial dysfunction in CVD (Kalliolias & Ivashkiv, 2015). TNFa is a well-established cytokine, typically produced by macrophages, that regulates cell function in duress (Kalliolias & Ivashkiv, 2015). It does so through a signaling pathway that ultimately leads to leukocyte recruitment by intermediate signaling chemokines (Kalliolias & Ivashkiv, 2015). Chemokine C-X-C motif ligands 2 and 3 (CXCL2/3) are leukocyte-recruiting chemokines downstream of TNFa that bind to a common receptor, CXCR2 (Serin et al., 2002; Vandercappellen, Van Damme, & Struyf, 2008). They are believed to promote angiogenesis, the ability to form new blood vessels, in most cell types (Al-Alwan et al., 2013; Wolpe et al., 1989). In mice, increased levels of CXCL2 have been shown to induce inflammation, a spur for angiogenesis (Xu-Vanpala, 2020). TNFa is generally believed to upregulate CXCL2/3; however, this effect remains largely unexplored in many standard laboratory cell models (Serin et al., 2002). Human Umbilical Vein Endothelial Cells (HUVECs) are a non-invasive, widely used model of human endothelial cells obtained from “medical waste” (Kocherova et al., 2019). Despite the general categorization of TNFa as an upregulator of Glutamate-Leucine-Arginine Positive motif (ELR+) CXC chemokines, these regulatory effects remain largely unexplored in HUVECs (Lo, Lai, Li, & Wu, 2014; Pappa et al., 2011). Because HUVEC models are a regular facet of vascular function studies, we have used them to investigate the effects of TNFa on CXCL2/3 mRNA expression using RT-qPCR. We hypothesized TNFa would upregulate CXCL2/3 in HUVECs like it has been shown to upregulate CXCL1, another ELR+ chemokine in the CXC family (Lo et al.,2014). Our RT-qPCR data effectively confirms our hypothesis that TNFa upregulates the expression of CXCL2/3 in HUVECs in vitro.
METHODS:
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J dividual cell lines, we may have discounted sample differences in TNFa CXC2/3 regulation. However, given the observed strength of upregulation, we can confidently confirm our hypothesis that TNFa upregulates CXCL2/3 in NT-HUVECs, perhaps only differing by the degree of upregulation in separate samples. Other limitations can be attributed to the imaging process of our dose-response cultures. By only capturing images of the cells at the beginning and the end of culture, it is possible we missed the finer aspects of HUVEC growth during treatment. In future investigations, we may incorporate methods that continuously track cell growth to provide a clearer picture of TNFa pathology in endothelial cells. Having confirmed the CXCL2/3 expression regulatory effects of TNFa, our next step will be to investigate the roles of CXCL2/3 and TNFa on endothelial cell function. Our results suggest CXCL2/3 are critical intermediary signaling molecules in TNFa's regulation of endothelial function. Because our qualitative imaging results indicated an impact on monolayer formation and cell viability, we will study these functions using quantifiable methods, including but not limited to electric cell-substrate impedance sensing (ECIS), wound-healing, and cell proliferation. We anticipate studying the effects of exogenous CXCL2 and CXCL3 on HUVEC function will elucidate the driving signaling molecule behind impaired endothelial function in CVD.
REFERENCES:
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Vandercappellen, J., Van Damme, J., & Struyf, S. (2008). The role of CXC chemokines and their receptors in cancer. Cancer Letters, 267(2), 226-244. doi:10.1016/j.canlet.2008.04.050
ACKNOWLEDGMENTS: We want to thank the members of the Zheng laboratory at the University of Wisconsin—Madison and Zhou laboratory at the University of Arizona—Tucson for reviewing our figures and manuscript, as well as team members at Meriter Hospital for assisting in sample collection.
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Godo, S., & Shimokawa, H. (2017). Endothelial Functions. Arteriosclerosis, Thrombosis, and Vascular Biology, 37(9), 108-114. doi:doi:10.1161/ATVBAHA.117.309813 Reiterer, M., & Branco, C. M. (2019). Endothelial cells and organ function: Applications and implications of understanding unique and reciprocal remodeling. The FEBS Journal, 287(6), 1088-1100. doi:10.1111/febs.15143 Kalliolias, G. D., & Ivashkiv, L. B. (2015). TNF biology, pathogenic mechanisms and emerging therapeutic strategies. Nature Reviews Rheumatology, 12(1), 49-62. doi:10.1038/nrrheum.2015.169
Lo, H., Lai, T., Li, C., & Wu, W. (2014). TNF-α induces cxcl1 chemokine expression and release in Human vascular endothelial cells in vitro via two distinct signaling pathways. Acta Pharmacologica Sinica, 35(3), 339-350. doi:10.1038/ aps.2013.182 Pappa, C., Tsirakis, G., Kanellou, P., Kaparou, M., Stratinaki, M., Xekalou, A., et al. (2011). Monitoring serum levels elr+ CXC Chemokines and the relationship between microvessel density and Angiogenic growth factors in multiple myeloma. Cytokine, 56(3), 616-620. doi:10.1016/j. cyto.2011.08.034 Zhou, C., Zou, Q., Li, H., Wang, R., Liu, A., Magness, R. R., & Zheng, J. (2017). Preeclampsia downregulates MicroRNAs in Fetal endothelial cells: Roles of miR-29a/c-3p in Endothelial Function. The Journal of Clinical Endocrinology & Metabolism, 102(9), 3470-3479. doi:10.1210/jc.2017-00849
Serin, Ý S., Özçelik, B., Bapbu∂, M., Kýlýç, H., Okur, D., & Erez, R. (2002). Predictive value of tumor necrosis factor alpha (TNF-a) in preeclampsia. European Journal of Obstetrics & Gynecology and Reproductive Biology, 100(2), 143-145. doi:10.1016/s0301-2115(01)00484-5
Al-Alwan, L. A., Chang, Y., Mogas, A., Halayko, A. J., Baglole, C. J., Martin, J. G., et al. (2013). Differential roles Of CXCL2 AND CXCL3 and their receptors in Regulating normal AND Asthmatic airway smooth muscle CELL MIGRATION. The Journal of Immunology, 191(5), 27312741. doi:10.4049/jimmunol.1203421 Wolpe, S. D., Sherry, B., Juers, D., Davatelis, G., Yurt, R. W., & Cerami, A. (1989). Identification and characterization of macrophage inflammatory protein. Proceedings of the National Academy of Sciences of the United States of America, 86(2), 612-616. doi:10.1073/pnas.86.2.612 Xu-Vanpala, S., Deerhake, M. E., Wheaton, J. D., Parker, M. E., Juvvadi, P. R., MacIver, N., et al. (2020). Functional heterogeneity of alveolar macrophage population based on expression of cxcl2. Science Immunology, 5(50). doi:10.1126/sciimmunol.aba7350
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TNFa is a potent upstream regulator of CXCL2 and CXCL3 in NT-HUVECs. Additionally, TNFa and CXCL2/3 are implicated in modulating endothelial cell function, a significant component of vascular function. Our results suggest that activation of the TNFa/CXCL2/3 pathway may contribute to endothelial dysfunction in different CVD, including preeclampsia. Given the widespread use of HUVECs in CVD research, our results will allow investigators to better understand the impact of inflammatory cytokines in this cell model. Our future studies will examine TNFa and CXC chemokines' specific roles in endothelial function, particularly angiogenesis. Ultimately, we aim to identify biomarkers and therapeutic targets for the prevention and treatment of CVD. Because CVD occupies a devastating role in global non-transmissible disease, understanding the intricacies of CVD pathology is imperative for identifying and implementing life-saving therapies.
World Health Organization. (2017, May 17). Cardiovascular diseases (CVDs). Retrieved February 23, 2021, from https://www.who.int/en/news-room/fact-sheets/detail/cardiovascular-diseases-(CVDs)
Kocherova, I., Bryja, A., Mozdziak, P., Angelova Volponi, A., Dyszkiewicz-Konwińska, M., Piotrowska-Kempisty, H., et al. (2019). Human umbilical vein endothelial cells (HUVECs) co-culture with osteogenic cells: From molecular communication to engineering prevascularised bone grafts. Journal of Clinical Medicine, 8(10), 1602. doi:10.3390/jcm8101602 JUST VOL VI // ISSUE II // SPRING 2021
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Table 1. RT-qPCR Gene Primer Information. Accession and catalog numbers for TaqMan primers purchased from Applied Biosystems by ThermoFisher Scientific.
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Fig. 2. TNFa Alters Cell Morphology and Inhibits Attachment. Images of pooled P4 NT-HUVECs (n=1) treated with varying concentrations of TNFa for 24 or 48 hours. Healthy HUVECs are translucent, spindle-shaped, and arranged in a monolayer. Cell debris (blue arrows) are identifiable as dark spots. Monolayer patches (red arrows) are areas without live cells. A. HUVECs imaged at 40x magnification. Scale bars, 500µm. B. HUVECs imaged at 100x magnification. Scale bars, 300µm.
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Fig. 1. TNFa Upregulates CXCL2 and CXCL3 mRNA. CXCL2 and CXCL3 mRNA expression in pooled P4 NT-HUVECs (n=1) treated with varying concentrations of TNFa for 24 or 48 hours. TNFa greatly increased CXCL2/3 mRNA levels, with maximum upregulation at 24 hours. CXCL3 (red) was more upregulated by TNFa than CXCL2 (blue).
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The Journal of Undergraduate Science and Technology (JUST) is an interdisciplinary journal for the publication and dissemination of undergraduate research conducted at the University of Wisconsin-Madison. Encompassing all areas of research in science and technology, JUST aims to provide an open-access platform for undergraduates to share their research with the university and the Madison community at large.