Spectrum Issue 8

Sp 08

Spectrum

SECTION 1 • PAGE 5

Biology The Discovery of the Dreaming Process

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Beta-amyloid May Cause Alzheimer’s at the Synapses

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Advances in Social and Cognitive Disorder

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Restless Genes

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Does the Secret of Immortality Lie in Telomeres?

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Mad Cow Disease

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How Cocaine Kills

12

Cell Theory

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by Jasmine Katz

by Mehr Suri

by Nicole Kaiser

by Sabrina Lautin

by Amory Tillinghast-Raby

by Alexander Karpf

by Jenny Wang

by Jacob Hoglund

SECTION 2 • PAGE 14

Physics & Astronomy Discovering Dark Energy

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The Universe is Curved

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Special Relativity Came First

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by Lauren Hooda

by Jeffrey Weiner

by Ajay Shyam

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The Enigma of Gravity

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Discovering Kuiper

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by Jenna Karp

by Abigail Zuckerman

SECTION 3 • PAGE 19

Chemistry The Accidental Discovery of Gunpowder

by Jason Ginsberg

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Ununpentium’s Discovery

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Rethinking the role of Uranium

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by Maddie Bender

by Veer Sobti

SECTION 4 • PAGE 22

Student Research Alzheimer’s Disease: An Overview

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Exoplanets

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by Lily McCarthy

by Cassandra Kopans-Johnson

Our Mission: To encourage students to find topics in science that interest them and move them to explore these sparks.

We believe that science is exciting, interesting and an intergral part of our futures. By diving into science we can only come out more knolwedgable.

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Letter from the Editor Dear Readers, This year, Issue 1 of Spectrum is being released right as snow is beginning to fall. The snow reminds me of the beginning of school. At first the cold from the snow piling up is painful and depressing, but once you get used to the cold, you have more time to enjoy the snow! Snow is incredible!

Did you ever look closely at a snowflake? It is hard to look closely at a snowflake because the structure falls apart once it melts. However, by attaching a bellows camera to a microscope, Wilson Bentley, at 20 years old, first captured the beautiful structures of snowflakes. His photos are unbelievable! Each snowflake is so intricate and detailed. As an artist myself, I cannot help but gawk at science’s work of art. Each snowflake is simply ice formed around soil particles in the air. The geometric wonder is left to the whim of the universe.

The universe around us is like a jigsaw puzzle, and we, as humans, strive to find the pieces that fit into each other. That is what this issue is about, discovery!

The articles in this issue are all chosen by the writers, presenting Horace Mann students’ broad spectrum of scientific curiosities. We also exhibit articles featuring the knowledge that students have acquired through classes outside of school or exciting research. Our writers and editors have worked very hard to put together a treasure chest full of interesting discoveries, so we hope you enjoy reading these articles.

We also hope this issue will inspire you to discover new things! After all, Bentley was only 15 when he first saw looked at snowflakes under an old microscope. It goes to show that anyone can discover new things with curiosity and determination. If you are in need of inspiration, I recommend reading some articles, looking at some snowflakes, and setting off with an open mind!

Thank you for reading this issue of Spectrum! Enjoy your winter break Horace Mann!

Brenda Zhou Editor in Chief Spectrum is a student publication. Its contents are the views and work of the students and do not necessarily represent those of the faculty or administration of the Horace Mann School. The Horace Mann School is not responsible for the accuracy and contents of Spectrum, and is not liable for any claims based on the contents or view expressed therein. The opinions represented are those of the writers and do not necessarily represent those of the editorial board. The editorial represents the opinion of the majority of the Editorial Board. All photos not credited are from creativecommons.org. All editorial decisions regarding grammar, content, and layout are made by the Editorial Board. All queries and complaints should be directed to the Editor-In-Chief. Please address these comments by e-mail, to hmspectrum@gmail.com.

Spectrum recognizes an ethical responsibility to correct all its factual errors, large and small (even misspellings of names), promptly and in a prominent reserved space in the magazine. A complaint from any source should be relayed to a responsible editor and will be investigated quickly. If a correction is warranted, it will follow immediately.

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Brenda Zhou Editor-in-Chief

Jenny Heon Mihika Kapoor Production Director

Joanna Cho Henry Luo Amanda Zhou Executive Editors

Yang Fei Ricardo Fernandez Managing Editors

Teddy Reiss

Communication Director

Grant Ackerman Isabel Friesner Lauren Futter Jason Ginsberg Kundan Guha James Kon Sonia Sehra Samantha Stern Abigail Zuckerman Junior Editors

Dr. Jeff Weitz Faculty Advisor

Biology reonis, Flickr Photo Sharing Sleeping white tiger

The Discovery of the Dreaming Process Jasmine Katz

Many facets of the human brain have yet to be completely understood, and dreaming is no exception. Unlike the almost invisible and intricate functions of the body that only specialized scientists can observe, we are immersed in our dreams every night. The enormous prevalence of dreams in our lives juxtaposed with the extreme lack of knowledge about them makes them a topic of interest and, for some, a devotion that lasts a lifetime.

To the ancient Greeks and Romans, dreams were messages from the gods. People trusted their dreams to heal their sicknesses, communicate with the dead, and lead them in war decisions. Similarly, The Chinese and Hindu Upanishads believed that part of one’s soul journeys to another dimension when dreaming.

With the Middle Ages came a darker outlook on dreaming. People believed that dreams were the result of the devil corrupting their unconscious minds to tempt them with sins.

In the early 19th century, dreams lost some of their grandeur from the ancient world as well as their malevolence from the Middle Ages because people simply gave less meaning to their dreams. Some people even considered them the product of household noises or indigestion. However, this perception drastically changed with the Freudian philosophy of dreams in 1899. Although Freud did not support his theories with scientific discoveries, his belief that dreams are the manifestation of repressed emotions was one of the major catalysts for further investigation into dreams.

A century after Freud proposed his theory of dreams, scientists have discovered some truth to it. Neuroscientist

Robert Stickgold conducted dream research to show that the work that brains do while dreaming helps cement memories, secures what we have learned throughout the day, and processes problems that our brains would otherwise have to process the next day.

In 1924, Hans Berger invented the electroencephalogram (EEG), a device to record patterns in brainwaves. The development of this machine was a significant step toward the discovery of the dreaming process because it allowed scientists to track brain activity during dreams. With the help of Berger’s technology, scientists discovered that the frequency of brainwaves is lowest during deep, dreamless sleep, whereas REM sleep requires a higher concentration of brain activity.

The discovery of rapid eye movement (REM) sleep in 1953 was a pivotal development. It added to the already established sleep cycle that was first described in 1937 to form a nearly complete visualization of the brain during sleep. The first stage consists of light sleep from which one can easily be awakened. The second and longest stage brings the slowing of heart rate and breathing as one moves deeper into sleep. The third and fourth stages represent the deepest sleep, and the fifth and final stage is REM sleep, where heart rate and breathing gains speed and the most dreaming occurs.

Technology has brought us so far in such a short period of time that our knowledge of dreams has increased exponentially in the past century, and the future will only bring more exciting research and results.

5

Biology

Beta-amyloid May Cause Alzheimer’s at the Synapses Mehr Suri

On September 20th, scientists studying at Stanford University discovered a deeper connection between the protein known as beta-amyloid and Alzheimer’s disease. Originally, scientists around the world had accepted that the development of plaques is what ultimately leads to the death of nerve cells, which leads to Alzheimer’s disease. However, according to Dr. Carla Shatz, head researcher of Alzheimer’s disease at Stanford Univeristy, “[This] discovery suggests that Alzheimer’s disease starts to manifest long before plaque formation becomes evident.”

According to the Alzheimer’s Association, Alzheimer’s disease is “…a type of dementia that causes problems with memory, thinking and behavior.” The true mystery lies in the cause of the disease. A nerve cell, also referred to as a neuron, is made up of specific parts, each serving an individual purpose for the cell. To envision a neuron, imagine a lollipop; the stick portion is the axon and the spherical portion, the cell body, holds the nucleus and dendrites. The axon is a system used to transfer impulses from one nerve cell to another. The dendrites are a portion of the cell whose main purpose is to connect two neurons together to allow the impulses to pass.

Scientists had originally predicted that Alzheimer’s was caused by the beta-amyloid deposits located inside and around the cell. It was hypothesized that the deposits would lead to degeneration of the cell, eventual loss of neurons, and ultimately Alzheimer’s dementia. Due to the discovery that recently took place, it is now proven that the beta-amyloid does in fact contribute to Alzheimer’s but not by itself. The research suggests that beta-amyloid combines with another protein, LilrB2, found in the synapse. Together, they make the synapse, the point at which one neuron connects to another, ineffective. By making these synapses ineffective, humans are affected by memory loss, difference in thinking, and change in behavior. Once the proteins have combined, they stimulate the enzyme Cofilin, which destroys Actin in the synapse.

The destruction of Actin causes the synapse to burst and prevents neurotransmission, leading to further memory problems, decreased processing of thoughts and emotions, and diminished control over our body parts should move.

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The disease’s physical effects are evident in the significant narrowing of the cortex area T bias, Flickr Photo Sharing

The question remains: how are we going to fix this problem? In the past, drug companies have tried destroying the beta-amyloid deposits. This drug prevention is all but too late, however, because if plaque is already present then your synapses have already been under attack. At this point there is really no going back, Alzheimer’s is incurable. However, there has been research taking place, particularly at Stanford, that aim to find cures to the disease. According to Dr. Carla Shatz, the best idea would be either nullifying the use of LilrB2, because without it, beta-amyloid is close to harmless, or using a drug to obstruct the attraction between beta-amyloid and LilrB2. These ideas seem probable, but researchers will need a few years to test them. So, even though the problem has been found, and a promising solution has been devised, Alzheimer’s disease will continue its horrid effect until further research brings results.

PET scan of a human brain with Alzheimer’s disease US National Institute on Aging, Alzheimer’s Disease Education and Referral Center

Biology

Advances in Social and Cognitive Disorders Nicole Kaiser

Puzzle pieces

yann.co.nz, Flickr Photo Sharing

Autism Spectrum Disorders (ASDs) and schizophrenia, both disabilities of cerebral specialization during the embryonic period, were previously thought to be unrelated. The comparable traits of individuals suffering from these disorders include social and cognitive dysfunction, trouble processing emotion, and limited ability to lead a normal life in the world. These symptoms burden the lives of over 2 million individuals in the U.S. alone, and scientists have been fiercely searching for a cure for over two decades. Fortunately, new research reveals that there is a significant genetic connection and familial association between these two seemingly independent conditions, which could provide scientists with more information about the root cause of such debilitating disorders and hopefully help develop specific treatments.

To measure familial association between schizophrenia and ASD, Dr. Mark Weiser of Tel Aviv University’s Sackler Faculty of Medicine studied three comprehensive databases. One of them stored anonymous information about over a million soldiers, including those affected with schizophrenia and autism. Dr. Weiser and his team found that individuals with a schizophrenic sibling were twelve times more likely to have autism than those without schizophrenia in their family. The results were reflected throughout all three databases, firmly linking these two disorders, and further supporting this revolutionary finding.

Additional research on the link between ASD and schizophrenia includes brain-imaging studies conducted in 2010 at the University of Hong Kong to determine if similarities exist in the cerebral structure of those affected with these disorders. The results revealed that lower grey matter volumes within the limbic-striato-thalamic circuitry, an area associated with behavioral and emotional expression, were prevalent in both ASD and schizophrenic participants. This information provides researchers with a visual explanation for the conditions and may lead to earlier diagnosis of such behavioral and neurological disorders, along with the possibility of tracking progression in treatment by use of periodic neuroimaging.

Further research done by Jordan Smoller of the Massachusetts General Hospital and Harvard Medical School uncovered a genetic link not only between ASD and

schizophrenia, but also with major depression, ADHD, and bipolar disorder. Smoller found several genetic variations that seemed to increase the risk of developing any of the five different disorders. Specifically, he identified a cluster of DNA variations in the calcium channel signaling genes associated with brain cell communication. This discovery may lead researchers to biological clues that can be targeted during treatment.

Due to ASD diagnosis, Tens of millions of families bear the onus of providing a loved one with lifelong care even through adulthood. Approximately 1% of the population over the age of 18, or about 51 million individuals, is currently suffering from schizophrenia. Thankfully, compelling discoveries related to these disorders are ongoing and new findings are constantly being revealed. Currently, these behavioral disorders are diagnosed by their symptoms, and not by their root causes, and treatment is also directed at improving symptoms. Further research may result in a better understanding of the origins of these disorders and finally provide scientists with a cause to target.

Autism Awareness Ribbon created in honor of all those affected by autism.

Cheryl’s Art Box, Flickr Photo Sharing

7

Biology

Restless Genes Sabrina Lautin

For humans to advance and create a more global, interconnected society, we must be willing to explore. Thanks to our efforts, communication has become effortless due to innovations in technology, such as the Internet and social networking, travel now takes a fraction of the time it used to, and science and medicine advance in leaps and bounds.

Surprisingly, according to National Geographic Magazine’s article, “Restless Genes,” all the aforementioned examples of technological advancement and people’s desire to improve the quality of life can be attributed to a single gene.

DRD4-7R, a gene carried by about 20 percent of all humans, controls dopamine production in the brain.

Dopamine is a neurotransmitter that functions in the central nervous system whose signal is linked to motivation, learning, and reward. David Dobbs, the author of “Restless Genes,” suggests that DRD4-7R “makes people more likely to take risks; explore new places, ideas, foods, relationships, drugs, or sexual opportunities; and generally embrace movement, change, and adventure.”

Additionally, DRD4-7R and 2R, a variant, are linked to human migration. Studies have shown that the gene frequencies of DRD4-7R and 2R are higher in present-day

migratory cultures than in stationary ones, and higher in populations whose ancestors were more nomadic, traveling greater distances from their points of origin. These results suggest that this gene played and continues to play an indirect but key role in trans-global travel. These hypotheses, however convincing, have ethical and social implications that challenge multiple aspects of academics and theology.

One possible effect of this idea is the newfound challenge posed to theological concepts such as predetermination and the absence of free will; if humans possess a gene that leads to discovery and exploration, then are any new discoveries truly examples of human ingenuity? Additionally, the possibility that geographic and intellectual expansion were not results of humans’ own volition but that they were the product of an endemic human trait has the potential to drastically alter how historical events and scientific discoveries are viewed.

Though we may never know for sure whether ancient human migrations were genetically driven or not, as the complete genetic code of these ancestral human beings is lost to science, human restlessness, be it genetic or otherwise, will continue to drive the advancement of the global community.

ScitechWA, Flickr Photo Sharing The iconic DNA tower of light.

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Biology Telomeres

Does the Secret of Immortality Lie in Telomeres?

National Human Genome Research Institute, Wikimedia Commons

For as far back as written records go, humankind has been searching for a fountain of youth. For a while it seemed as if scientists had found one in the form of telomeres. Telomeres are repeating sequences of DNA (for example TTAGGG) at the end of each chromosome; they work like shoelace caps. Cellular aging is directly correlated to the shortening of these telomeres. As cells divide, telomeres shorten; once the telomeres reach a critical length the chromosome can no longer divide and the cell dies. Telomerase is a protein that adds repeating sequences to the end of the existing telomere elongating the lifespan of the cell. While adding telomerase seems like a way of immortalizing humans, there’s a problem: increased levels of telomerase are directly linked to cancer.

Most cells die before they can mutate enough to become cancerous; cells with increased telomerase do not die and continue to mutate. Therefore, adding telomerase would not be a logical attempt at immortality.

An engineer by the name of Dmitry Itskov says that he has an alternative way of achieving “immortality,” which he calls the 2045 initiative. The idea is to create an avatar version of yourself that could in theory live forever, even after your death. While this may seem like delusional ramblings, according to James A. Pearson, this concept has attracted the top minds of universities such as MIT, UC Berkeley, and Harvard . This project would go through several stages titled Avatar A through Avatar D. Avatar A would be a robotic duplicate of a human body controlled by a computer. Avatar B would be made by transplanting a human brain into the avatar and keeping it alive with a life support system. Avatar C would have an artificial brain and a computer would transfer the person’s consciousness into the brain. The idea of creating a synthetic consciousness merits further discussion in and of itself.

Consciousness is defined as, “the quality or state of being aware of an external object or something within.” Consciousness is understood as stemming from the “neural correlates of consciousness,” specifically from connections between memories and current perceptions or ideas. Avatar C is intended to duplicate in order to have the individual’s original consciousness . At this point it would seem that we have an accurate duplicate of the original person made from circuits, wires, and software. However, if we consider for a moment that consciousness for each of us will include the memories

Amory Tillinghast-Raby we have yet to make, not just the memories we already have, then that android can never be you. From the point of its origin until years after its human base is dead, the android will keep accumulating new memories; its core being will evolve and mutate with time. Just as you aren’t the same person you were a year ago, the android version of you after you die will evolve into a different person than you once were. While the changes might not be that significant over a period as short as two years, over a period of fifty a whole new personality will be formed.

The final avatar is predicted to remove the mechanical body of Avatar A, and replace it with an holographic body impervious to the usual physical damages. All of this was designed because humans are afraid of death, but these avatars are essentially talking photographs. As James A. Pearson contemplates, “What a strange immortality it will be when a dying Itskov watches himself go on living, and an immortal Itskov watches himself die.”

A four step blueprint for creating a hologram-like avatar to let humans live forever.

Theseoduke, Flickr Photo Sharing

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Biology

Alex Karpf Mad Cow Disease

Cows freefotouk, Flickr Photo Sharing

Having spread rapidly throughout England in the 1980’s and 1990’s, mad cow disease led to the deaths of thousands of cows, triggering the United Kingdom government to kill another four million in an eradication program. Mad cow disease is an illness that shares symptom characteristics with a similar prion, infectious agent, which infects humans causing Creutazfeldt-Jakob disease (CJD).

In 1982, Stanley Prusiner, of the University of California, San Francisco announced that he and his co-workers had created and isolated a pure infectious protein . This protein, which Prusiner named a prion, was believed to be the infective agent of neurodegenerative diseases such as Mad Cow’s Disease. Such prion diseases are called transmissible spongiform encephalopathy .

Prions are proteins, chains of amino acids folded into complex and specific three-dimensional shapes, which perform specific duties within a cell and interact with other

Alexander Karpf proteins. However, distorted prions have the unique ability to deform regular prions upon contact. In an attempt to get rid of these abnormal prions, lysosomes, digestive enzymes encased in vesicles, try but are unable to break down the prions. The prions continue to accumulate in the lysosome, ultimately killing the cell and setting free more prions to ravage and kill more cells. As more cells are destroyed, the brain gradually loses its ability to function and the organism begins to die. A brain devastated by prions appears as a sponge due to all of the holes formerly occupied by cells .

Bovine spongiform encephalopathy, commonly known as mad cow disease, first spread through feed containing the meat and bone meal of other cattle. Prions are believed to have been present in this feed, thus spreading to other cows through consumption. Without proper regulations, parts of infected cattle containing prions became an ingredient of feed, and the cycle continued . The first cow to become in-

Thuey, Wikimedia Commons PrPsc induces conformational change in PrPc, an example of a mutation of a prion

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Biology fected was diagnosed in 1986, and soon the disease spread throughout the United Kingdom. In total, 180,000 cattle have been infected and 4.4 million have been slaughtered in the UK’s eradication program . However, before regulations preventing the risks of possibly infected meat entering human food were passed in 1989, the meat of more than 460,000 infected cows had entered the food market . Humans who consumed this prion-containing offal were infected by a new version of a human prion disease, called new-variant Creutzfeldt-Jakob disease. The illness is almost always fatal within a year, beginning with memory loss and causing blindness, weakness, and involuntary shaking. By 2009, 210 people around the world , including 176 in the United Kingdom, had died of this new variant.

Since the advent of this disease, the US has developed guidelines and regulations to prevent the disease from spreading in the US. Feed that could spread the disease has since then been banned, and nervous tissues that would be most likely to carry the disease, such as the brain and spinal cord, have been removed from any cattle that could possibly have the disease . In addition, the US has tested more than a million cattle since the discovery of the disease and has completely banned and euthanized all cattle exhibiting any signs of neurological disorder . Although prions are most heavily concentrated in nervous tissue, it can also be found in almost

all other types of tissue, including blood . Thus, the removal of nervous tissues does not ensure that meat cannot carry the infectious agent.

The existence of prions is the most widely accepted explanation of transmissible spongiform encephalopathy such as the bovine variant, mad cow disease. In 2005, researchers from the University of Texas successfully injected synthetic prions into mice and produced neurodegenerative disorders within the rodents . Still, the process by which prions infect and kill, the prion hypothesis, is a controversial issue. While all known infectious agents, or pathogens, possess nucleic acids like DNA, which govern the actions of the cell, prions refute this central tenet of Biology by not possessing any .

The prion hypothesis is still undergoing research and being tested, and prions have been shown to cause the death of cells and lead to infection and death in both cows and humans. Although transmissible prion diseases have been almost entirely eradicated, there is always the small risk that cattle meat carrying the disease will enter food supply.

Brain tissue infected with riant Creutzfeldt-Jakob disease, the human form of mad cow disease.

Patho, Wikimedia Commons

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Biology

How Cocaine Kills

Jenny Wang Cocaine cutted at mirror Iavsen, Flickr Photo Sharing

There is a top of the pyramid for every aspect of culture. Just as the Ivies are the top of the college hierarchy and the Olympics are the ultimate form of athletic perfection, cocaine is commonly known as “the caviar of street drugs” or the “rich man’s drug.” It is easily one of the most expensive drugs available.

However, high prices do not lead to milder complications.

Not only does cocaine prove to be detrimental to the actual user by causing heart failure, respiratory problems, and anxiety, but studies have also shown that fetal exposure to cocaine can affect fetus’ neurological and physiological development. These problems include defects and abnormalities of the heart, liver and genitals. According to Science Daily, children who have been exposed to cocaine usage are more likely to “have impairments in attention, control, stress, emotion regulation, and memory” in comparison to their peers who had not been exposed to cocaine.

These deficits are due to the fact that the affected children have less gray matter in certain areas of their brains than unaffected children. Gray matter is typically found in the regions of the brain that are responsible for collecting information from the senses, controlling muscles, emoting, and using memory.

PET scans of a normal brain and a brain affected by cocaine

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Brookhaven National Laboratory, Flirckr Photo Sharing

One of the most alarming discoveries, however, is that “each 1-mL decrease in gray matter volume increases the probability of initiating substance use by 69.6% to 83.6%.” Cocaine usage and addiction can be an endless cycle that dominates the lives of the users as well as their children. Scientists have discovered that while the brain of an exposed infant might seem functional at birth, it is very possible for the development of the brain to go awry.

The dangers and consequences of exposure in the womb are not limited to possible drug addiction or difficulty concentrating.

Many people develop anorexia, schizophrenia, and ADHD. In addition, scientists have observed that these children are more likely to become risk-takers as well as have violent tendencies.

These facts and observations have highlighted the need for the development of new programs that are successful in both breaking the addiction, as well as maintaining a drug-free lifestyle. It is essential that we begin to break this continuing cycle of cocaine addiction in order for the health, safety, and even financial stability of our future generations to be preserved.

Biology

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Above: top row (from left to right): blood cells (Bruce Wetzel and Harry Schaefer, Wikimedia commons); cardiac cells grown from stem cells (British Heart Foundation, Flickr Photo Sharing), primary neurons (Zeiss, Flickr Photo Sharing); cortical neurons and glial cells in culture (Zeiss, Flickr Photo Sharing); bottom row (from left to right) - smooth muscle cells derived from ES cells (Callifornia Institute for Regenerative Medicine, Flickr Photo Sharing); injured muscle cells (Journal of Cell Biology, Flickr Photo Sharing), and then repeated images.

By Jacob Hoglund Whereas today the word “cell” is part of the common vernacular and taught in every 9th grade biology class, this word was unheard of before the 17th century, when Robert Hooke discovered the cell, the fundamental unit of life.

Hooke’s initial observations would become the basis of cell theory, which stands as the foundation of biology. The cell theory, established by Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow contains three main proposals: all living things are made of cells, new cells can only be created by old cells dividing into two, and cells are the basic building units of life. Though these statements are simple, they provide the backbone of our modern understanding of biology and medicine.

Certain discoveries were necessary for cell theory to be proposed, improved, and accepted. Early light microscopes, introduced in the 1590s were not adequate for the observation of what we know as organelles, smaller structures within the cell that serve specific purposes. In order for cells to be analyzed and understood, advancements in microscopy were essential. Microscopes invented by Galileo and Robert Hooke allowed for the increased magnification of small objects. However, even these improvements to the microscope did not allow scientists to identify cellular components. Later, a researcher by the name of Anton van Leeuwenhoek was able to further the magnification of microscopes and identify moving cells, which he called animalcules, and more notably, bacteria. The second advancement leading to cell theory

was the scientific method, created by Galileo Galilei, which enabled scientists to compile their observations. Eventually, after observing many forms of life, all containing cells, Schwann and Schleiden hypothesized that cells are the basic unit of life.

Though the cell theory was the product of years of original work and discovery, it was also riddled with corruption amongst scientists. For example, Rudolf Virchow, a researcher of cell theory, stole and published another researcher’s, Robert Remak’s, work in 1855, which proposed that all living things come from other living things.

As cell theory developed into what is now accepted as a truth, it paved the way for other disciplines, such as germ theory, to develop. A key component of modern medicine, germ theory, proved by Louis Pasteur, states that microorganisms not visible to the naked eye cause diseases. In order for germ theory to be established, it was vital to know that cells existed as the basic unit of life.

The development of cell theory depended on scientific advancements and served as a tool for advancement, significantly influencing other fields of science. In this way, cell theory is an excellent example of scientific progress and the connection between different fields of science.

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physics & astronomy

Disco

vering

Dark

NASA. An artist’s depiction of the debris surrouding a white dwarf, the kind of star whose death causes a type Ia supernovae. The light emitted by these supernovae was use to detect the accelerating expansion.

In the most popular cosmological model, the universe is believed to have expanded rapidly after the Big Bang, taking nearly three billion years to slow down in its expansion.

However, observations made by scientists Saul Perlmutter of the Lawrence Berkeley National Laboratory, Brian P. Schmidt of the Australian National University, and Adam Riess of the Space Telescope Science Institute, have led to the theory of dark energy. Dark energy is an expansive force, a hypothetical energy-density that uniformly fills the vacuum of space with negative energy, therefore causing the Universe to expand at an accelerating rate. It is thought to make up 68% of the universal density, have a low density, be very homogeneous, and is not known to counter any other fundamental force other than gravity. The implication of this discovery is momentous: it implies that the dominant force in the evolution of the universe is not gravity. The repulsive effects of dark energy also seem to guarantee that the universe will continue to expand forever. Dark energy not only challenges our existing comprehension of physics, but also sparks questions about the fate and future of our universe.

This year marks the two year anniversary of the Nobel Prize in Physics being awarded to Perlmutter, Schmidt, and Riess for first observing the accelerated expansion of the universe. In 1998, these researchers were studying the light emitted from the deaths of white dwarf stars, known as Type Ia supernovae. As light from the supernovae’s most distant explosions traveled toward Earth, researchers found that the light was stretched by the universe’s expansion so that it appeared red, an occurrence known as redshift. The higher the redshift, the longer the light had been traveling and the further back in time the supernova occurred. By observing the supernovae’s redshifts, Perlmutter, Schmidt, and Reiss were able to determine that the supernovae’s host galaxies were flying away from each other at accelerating speeds.

Regardless of this evidence, some scientists, such as Riess, contest the existence of the mysterious force known as dark energy. Such scientists believe that deepening the un14

Energ

y Lauren Hooda

derstanding of gravity will explain why the universe is expanding at an accelerating rate, for a reason other than dark energy. The fact that dark energy has escaped detection by most technology reinforces this notion.

On the other hand, subsequent supernovae studies have since directed researchers to believe that dark energy has been affecting galaxies for nearly nine billion years. Cosmic microwave background radiation, as well as improved measurements of supernovae and redshifts, has corroborated the theory of an accelerating universe. As a result, physical astronomy and cosmology accept that dark energy is the most hypothetical form of energy that permeates space and accounts for the accelerating expansion of the universe.

Years after the Noble-worthy discovery of the accelerating universe and the theory of dark energy, researchers continue to analyze cosmic waves, map redshifts, and attempt to elucidate the force’s exact meaning and existence. Dark energy is a theory that stretches conventional physics and entails mysteries of the universe’s future. It is only the start of a string of complexities, intricacies, and discoveries that scientists are working to discern.

NASA. An image of a shock wave caused by a type Ia supernova.

physics & astronomy

The Universe is Curved

By Jeffrey Weiner

Since the early days of humanity, the elegant and infinite vastness of space has inspired people to explore its structure and mechanics. In 2004, measurements of cosmic background radiation gathered by NASA’s Wilkinson Microwave Anisotropy Probe suggested that the universe was asymmetric rather than flat, as many scientists believed. To confirm that the data collected was not due to a systematic error, the European Space Agency developed the Planck spacecraft that mapped cosmic background radiation with higher precision than NASA’s probe, an earlier version that obtained the same results earlier this year.

Scientists have rapidly responded to this new information with novel theories about how the universe is structured. In the past, many scientists have discussed a possible period of rapid expansion right after the Big Bang, known as cosmic inflation. In this model, the universe is considered to be flat, and its expansion is based on the inflaton, a quantum field.

This hyper expansion creates tiny density fluctuations known as primordial fluctations, which enlarge to become the seeds of other galaxies.

Researchers Andrew Liddle and Marina Cortês of the University of Edinburgh, UK, have expanded upon the model of cosmic inflation by using newly published results regarding the universe’s asymmetry. Liddle and Cortês suggested the existence of a second quantum field known as the curvaton, which generates the density fluctations in the earlier model. In the scientists’ new model, the inflaton would only control the hyper expansion of the universe, rather than regulate both the hyper expansion and the density fluctuations, as suggested in the earlier model. The two scientists showed that the curvaton would create the lopsided density fluctuations in the universe only if space had a slightly negative curvature. Based on this

cyber bytes, Flickr Photo Sharing vector Illustration of a planet

theory, the asymmetry of the cosmic background radiation in the universe would be due to an irregular scale of the universe determined by the curvaton field.

Furthermore, the magnitude of the curvature of the universe can be used to determine its shape. NASA scientists claim, “If space has negative curvature, there is insufficient mass to cause the expansion of the universe to stop. In such a case, the universe has no bounds, and will expand forever.

This is called an open universe.” In lay people’s terms, such a universe would have a hyperbolic shape resembling that of an infinitely expanding saddle.

Therefore, while many still believe that the universe is flat, the anomalies in the cosmic background radiation data suggest otherwise. The irregularities in the data predicted by Liddle and Cortês’ model could fit within the limits based on the measurements taken by the Planck probe. Which theory is right? We still don’t know. More measurements in the near future will determine which theory is correct.

cartoon view gives an impression of how common planets are around the stars in the Milky Way ESO/M. Kornmesser, Wikimedia Commons

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physics & astronomy

Special Relativity Came First Johnstone, Wikimedia Commons Illustration of Spacetime Curvature.

The General Theory of Relativity was one of Einstein’s crowning achievements and discoveries, one that would make him famous in modern physics. Before the General Theory of Relativity, however, he developed another theory, the Special Theory of Relativity, which led to the development of the General Theory of Relativity, his most phenomenal theory.

The definition of the word “special” is “of a distinct or particular kind.” Einstein’s Special Theory of Relativity was indeed special because it applied to a particular situation concerning the illusive perception of non-accelerating observers. For example, say that a person could visibly see a wave of light moving in a vacuum of space. Its speed would be constant at 3.00 X 108 meters per second. If this person moved along-side the wave of light at the same speed, the light wave would look as if it were not moving at all; however, the wave of light would still be moving at a speed of 3.00 108 m/s. All that matters is how fast the person and the wave of light are moving in relation to each other. Einstein’s theory led to his discovery that space and time were connected in something called space-time, which meant that events could happen at different times for different observers.

Whether this theory was “special” was a problem disputed by many contemporary scientists, for the theory only applied to observers moving at constant speeds. Thus, Einstein spent the next ten years trying to include acceleration (the rate at which the velocity of an object changes) in his theory to form a more general theory of relativity. His general theory of relativity was, in a nutshell, a theory regarding gravity: objects tend to move because they are pushed by a force, not pulled. Isaac Newton recognized this revised idea, but with his experimental results, he could not determine what force was pushing the object in motion towards the Earth. So, Newton identified a force known as gravity, and declared that gravity is responsible for pulling objects down towards the center of the Earth.

In response, Einstein challenged Newton’s description of gravity. At this point in time, Einstein was a technical assistant at the Swiss PatUnknown, Wikimedia Commons. ent Office. As he sat at his desk, he Albert Einstein in 1921.

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Ajay Shyam would look out of his window and watch the workers on the rooftops of adjacent buildings. Einstein imagined one of the workers falling. If the worker fell, the worker would not feel his own weight, and would therefore be weightless. Einstein realized that the same effect would be achieved if the worker was in an elevator and the cord holding the elevator was cut. The elevator would be falling at the same rate as the worker, who would again be weightless and falling. It was at this point that Einstein understood that massive objects (such as the Earth) distort space and time, resulting in the phenomenon of gravity. Space is actually warped around us (such as the elevator around the worker), and this space is actually pushing us onto the Earth and keeping us here. The distortion of the space-time continuum caused by massive objects is felt as the force of gravity. Einstein published this new theory in 1915.

How do these theories, the founding pillars of modern physics and quantum mechanics, actually help us today? One answer is the Global Positioning System (GPS). At least two dozen satellites orbit the Earth at 14,000 km/hour, with built in atomic clocks. The gravity experienced by a satellite in orbit nearly 20,000 km above Earth is 4 times weaker than that felt by a being on the ground of Earth. Einstein’s theory of general relativity says that gravity curves space and time, so therefore the clocks in the satellites tick slightly faster.

Through signals between each of the satellites and the receiver, and by Euclidean geometry, the GPS receiver’s location is computed both in terms of space and time.

Recently, astronomers have used Einstein’s theory of special relativity to locate a planet. The astronomers utilized a subtle effect initially predicted by Einstein’s theory, called “the beaming effect.” The beaming effect is the phenomenon in which light emitted from a star brightens as a planet in the star’s solar system pulls it slightly closer to Earth and dims as the planet pulls it away. This planet is officially known as Kepler-76b and orbits a star that makes up the constellation Cygnus, which is located nearly 2,000 light-years from Earth.

The planet was nicknamed “Einstein’s planet.” Whether they are used in everyday applications or for deep space study, Albert Einstein’s theories of Special Relativity and General Relativity, collectively referred to as Einstein’s Theory of Relativity, have remained as two of the most significant scientific discoveries in the 20th century.

physics & astronomy

The Enigma of Gravity: From Aristotle to Newton

Jenna Karp WilliamKF, Wikimedia Commons This new NASA Hubble Space Telescope image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies

Does the speed of a metal ball falling toward the earth depend on the heaviness of the metal? No, but if you thought so, you are in good company. The ancient Greek scholar Aristotle also thought that the way an object fell relied on its intrinsic properties, a misconception that was not corrected until the scientific discovery of gravity.

Aristotle, in the 4th century BCE, thought that when a metal ball and feather were both dropped, the ball hit the ground first because of the properties of the metal. He came to this conclusion simply via philosophical thought about the ball and the feather. Because what people saw day-to-day did not contradict Aristotle’s theory, his ideas remained unquestioned until the 16th century, nearly two millenniums later.

Galileo Galilei, born in 1564, was the first to conduct mathematical experiments that tested gravity. From atop the Leaning Tower of Pisa in Tuscany, Italy, Galileo dropped two balls, one made of metal and the other wood. The balls were identical in size but had different masses. Contradictory to Aristotelian theory, the two balls hit the ground at the same time. Galileo concluded that, neglecting air resistance, the acceleration of all falling objects towards the earth is the same.

Sir Isaac Newton, a British physicist born in 1642, expanded upon the discoveries of his predecessor Galileo.

According to legend, Newton was inspired by an apple’s fall from a tree. While watching the apple descend, Newton wondered how the fruit fell and why the direction of the fall was always perpendicular to the earth. He realized that a force

must have acted on the falling apple to accelerate the apple from rest.

Whether or not his theory was really prompted by falling fruit, Newton developed three mathematical laws of motion.

Firstly, an object remains at rest or moves at a constant velocity unless acted upon by an external, unbalanced force.

Secondly, the force acting on an object is equal to the product of the object’s mass and the object’s acceleration. Lastly, when one body exerts force on a second body, the second body exerts a force of equal magnitude in the opposite direction.

Newton’s three laws of motion, in conjunction with his Law of Universal Gravitation, explain many phenomena, including why apples fall from trees and why the moon circles the Earth. Newton named the force involved in these situations “gravity.”

Therefore, a metal ball’s fall to Earth is not regulated by the properties of the ball itself but by gravity. Newton’s Laws of Motion and a general understanding of gravity have proven to be extremely significant by serving as a basis for classical mechanics. Classical mechanics, the study of the motion of bodies, was an impetus for the Industrial Revolution, the 18th century transition to new manufacturing methods.

Thanks to Newton’s elaboration of the mathematical experiments of Galileo, we have a better understanding of and an increased ability to manipulate the forces that govern our world.

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physics & astronomy

Discovering Kuiper:

Home of Comets, Rocks, and Pluto

By Abigail Zuckerman Artist’s conception of Epsilon Eridani, a planetary system NASA’s Marshall Space Flight Center, Flickr Photo Sharing

Have you ever wondered where comets come from?

Those big, bright streaks of light cross the sky every so often and stir up all sorts of excitement. Or if you have not seen a comet, maybe you have seen a shooting star. It turns out that both of these wonders come from the Kuiper Belt, a diskshaped region of our solar system located beyond the asteroid belt. The Kuiper Belt begins just beyond Neptune, about thirty astronomical units (AU) from the Sun, and extends to about fifty-five AU from the Sun. It is filled with icy bodies, called Kuiper Belt Objects (KBO’s), made mostly of rock, ammonia, methane, and ice, which trace enormous elliptical orbits around the sun. The Kuiper Belt is sometimes called the Kuiper-Edgeworth belt, as two astronomers, Gerard Kuiper and K.E. Edgeworth, have independently hypothesized its existence. Edgeworth first proposed the Belt’s existence in 1943, and Kuiper published his own theories about a decade later. However, the first astronomer to ever consider the belt’s existence was Frederick C. Leonard, who pondered whether Pluto was in fact the first of a series of ultra-Neptunian bodies. Leonard turned out to be right, though it took over fifty years for astronomers to finally recognize any evidence of the Belt in its entirety. The first KBO ever discovered was indeed Pluto, whose existence was confirmed in 1930 by Clyde Tombaugh at the Lowell Observatory, but it took over seventy years for it to be recognized for what it was, a KBO, rather than a planet.

David Jewitt observed one of the first KBO in 1992.

Beginning in the 1980’s, Jewitt wondered why the farthest reaches of the solar system were empty, and developed two hypotheses, one to explain why there might be nothing there and one to explain why they simply may not have been seen yet. In testing these hypotheses, Jewitt found a one hundred and fifty mile-wide mass of rock and ice at the far reaches of the solar system. This finding, along with a slew of other KBO’s he observed in subsequent years, began a cascade of locating similar objects that came to be collectively known as the Kuiper Belt.

Once the Belt was discovered, the question of where KBOs originated from arose, a question that remains unan18

swered to this day, despite the large number of theories that have been developed. So far, the most logical and workable hypothesis for the origins of KBOs is that they are remnants of the solar nebula, a massive, spinning disk of matter that flattened and coalesced into our solar system. KBOs, like our planets, would have been formed through accretion, the process of formation of clumps of matter which grow and attract more matter until bodies large enough to have significant gravitational pull are created. The composition of KBO’s is very different from those of the planets in the inner solar system because in the outer, freezing regions of the nebula, many (usually gaseous) substances solidify.

KBOs are therefore effective time capsules of the solar nebula, and therefore can provide invaluable information about the formation of the solar system. Astronomers believe that KBOs that orbit near the inner rim of the Belt can pass into the inner solar system, where they would be caught in the gravitational pull of Neptune and passed on to Uranus, Saturn, and Jupiter, before being slingshot towards the Sun. In this scenario, the KBOs would then have three possible fates; they can be consumed by the Sun, flung in a hyperbolic trajectory, or caught in an elliptical orbit around the Sun. Once the KBOs pass close enough to the Sun, the immense heat would cause the volatiles on their surface to vaporize, thus creating the classic comet tails that can occasionally be seen from Earth. Halley’s Comet, for example, has been studied quite extensively, and its estimated composition and orbital pattern suggest that it is a type of KBO. Despite many recent findings, much about the Kuiper Belt still remains unknown. Hopefully, more answers and explanations regarding the Kuiper Belt’s composition and existence will be found as New Horizons, a NASA mission launched in 2006, collects more information. The mission involves the launching of a spacecraft, which is expected to reach Pluto and the Kuiper Belt in less than two years. If the mission is running smoothly and some of the farthest reaches of our solar system can be seen up close, then who knows what mysteries of deep space may be uncovered?

Chemistry Gunpowder Mill at Launceston, Tasmania, Australia.

Arthur Chapman, Flickr Photo Sharing

The Accidental Discovery of Gunpowder Jason Ginsberg For the past millennium, every life lost in battle, from the coast of Hastings, to the beaches of Normandy, and to the jungles of Vietnam, can be traced back to a single accident in 850 C.E. That year, Chinese alchemists discovered gunpowder in an unintentional explosion, making one of the biggest mistakes in human history.

During the Song Dynasty, it didn’t get much easier than being emperor; the job came with adoration, riches, and power. There was just one tiny problem that the emperors couldn’t get over: mortality. For years, Chinese alchemists, at the command of their rulers, toiled to create a mystical substance that would grant eternal life. These alchemists worked on a complex set of beliefs relating the properties of metals to spiritual enlightenment. For example, they believed that gold, which never tarnishes, strengthened the body and contribute to longevity if ingested. These alchemists were also particularly interested in sulfur because of its ability to burn.

One fateful day, a scientist, whose name has been lost to history, created a mixture of 10 parts sulfur, 15 parts charcoal, and 75 parts saltpeter obtained from manure. Unbeknownst to the alchemist, the charcoal provided a fuel that was oxidized by the saltpeter to form carbon dioxide and energy, which then reacted with the sulfur and nitrogen to form more gasses at a violent rate. In other words, there was a large bang. According to one observer the alchemist’s “hands and face [had] been burnt, and even the whole house where he was working burned down.” Gunpowder had been discovered, and its horrible uses were soon to follow.

The popularity of gunpowder exploded immediately.

Performers began using gunpowder to amaze their audiences, and fireworks became popular spectacles in celebrations.

Gunpowder was first used in battle against the Mongols, who were constantly invading China at the time. By affixing tubes of gunpowder to the tips of arrows, the Chinese stunned their

enemies with “flying fire.” The arrows produced loud bangs upon impact as the ignited gunpowder created immense amounts of gas and pressure, bursting its container. Just the fear and awe overwhelming their enemies were enough to give the Chinese an advantage in battle. Within years, the Chinese would master gunpowder as a weapon, using their knowledge to invent the cannon and grenade. However, gunpowder would only truly leave its mark on history once it diffused across the rest of the world.

Tying to maintain their military advantage, the recipe for gunpowder was kept a secret by the Chinese for four hundred years. However, in the 13th century gunpowder finally made its way to Europe and the Islamic World via the Silk Road. Gunpowder quickly revolutionized the role of the soldier and gave rise to modern warfare with the invention of the gun. This technology won many of the pivotal battles in modern history, giving an edge to Mehmed II in the siege of Constantinople, the French in the Hundred Years’ War, and the Andalusians in the siege of Seville. As Niccolò Machiavelli wrote, “There is no wall, whatever its thickness that artillery will not destroy in only a few days.”

By the 17th century, non-weaponry uses of gunpowder were also implemented. For example, the French were the first to use gunpowder in construction, blasting rock to build the Languedoc Canal. However in the 18th century, gunpowder rapidly lost popularity and safer alternatives such as nitrocellulose, perchlorates, azides, and fulminates eventually replaced it.

Ironically, scientists attempting to prolong life gave birth to the one of the world’s deadliest materials. Though gunpowder is now outdated, its effect on society has been tremendous in the realms of science, politics, and warfare. Its discovery is a true testament to the legacy of accidents and the ability of single man’s mistake to transform the world.

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Chemistry

Ununpentium’s Discovery Maddie Bender

A particle accelerator was used in the creation of the new element. highlander411, Flickr Photo Sharing

In late August, a team of scientists at Lund University in Sweden repeated the results of an experiment performed in 2003 and proved the existence of element 115, Ununpentium. Ununpentium was first created when the scientists used a device called a cyclotron to bombard a thin sheet of Americium-243 (element 95) with calcium-48 ions, producing 4 atoms of an element, each containing 115 protons, which later decayed to form Ununtrium. This groundbreaking discovery will lead to further possible uses of element 115 and other synthetic elements.

As of now, 20 synthetic elements, including Ununpentium, have been created in the lab. Since these elements do not occur in nature, scientists have only ever been observed these elements in very small quantities - approximately 50 atoms of Ununpentium have been synthesized to date. The only time they have ever been recorded outside the lab was as a by-product of nuclear weapons. Element 115, like all other synthetic elements, has proven to be extremely unstable.

For example, the most stable man-made isotope of Ununpentium has a half-life of only 173 milliseconds, while naturally occurring elements such as carbon have half-lives of up to 5,700 years. Scientists believe that element 115 decays extremely quickly due to the ratio between its protons and neutrons. They predict that with 184 neutrons, element 115 could possess a longer half-life, enabling researchers to find uses for the new element. A procedure to add enough neutrons, however, is still unknown.

While most of the synthetic elements have no known uses besides for research purposes, in part because of their 20

short half-lives, similar elements such as plutonium and einsteinium have been discovered to be useful as a type of fuel and a calibrator in spectrometers, respectively. In the future, scientists plan to perform more experiments to determine both the chemical properties of element 115 as well as the existence of other Ununpentium isotopes. This discovery was especially important to researchers as it helped to prove and explain many of the overall properties of the nuclei of all super-heavy atoms, not just element 115. Dirk Rudolph, a professor of Nuclear Physics at Lund University where this discovery took place, said that the scientists’ findings “can be regarded as one of the most important experiments in the field in recent years, because at last it is clear that even the heaviest elements’ fingerprints can be taken. The result gives high confidence to previous reports. It also lays the basis for future measurements of this kind.”

DePiep, Wikimedia Commons Molecular Model of Ununpentium

Chemistry Tunisia-live.net

simon.hucko, Flickr Photo Sharing

Uranium is radioactive.

Rethinking the Role of Uranium Veer Sobti Martin Klaproth, a German chemist, discovered uranium in 1789 by isolating the element from pitchblende, a highly radioactive mineral. However, no one paid much attention to uranium because they were unaware of its properties. It was not until the late 1800’s when scientists resumed work with uranium. In 1896 French physicist Henri Becquerel discovered the radioactive property of uranium after noticing the rays it emitted. Later, Polish physicist Marie Curie determined the exact radioactivity of uranium and that it was much less radioactive than the pitchblende. She hypothesized that there was another radioactive element in the mineral that supplemented the radioactivity of uranium in the pitchblende. Through experimentation she isolated two new radioactive elements from pitchblende: polonium and radium. The properties discovered by these scientists have made the element very useful in nuclear power plants, yachts, airplanes, and radiation shielding.

Although uranium has beneficial uses, because it can be used to make nuclear bombs, it poses a serious threat.

On August 6, 1945, the United States unleashed “Little Boy,” the first nuclear bomb ever used in warfare, on Hiroshima, Japan during World War II. “Little Boy” was a gun type fission weapon, which meant that the explosion came from a fission reaction, made with uranium-235, a very uncommon isotope of uranium. Uranium is used in nuclear weapons because of its effectiveness in starting both nuclear reactions and radioactive decay reactions,

making it perfect for fission reactions. This process releases both gamma rays (free neutrons and photons) and a large amount of energy. The gamma radiation produced causes cancer to anyone within range of the bomb. These qualities of uranium make it both useful and dangerous.

The world must be conscious and careful with their uses of this element. Despite its effectiveness in producing energy, a new energy form should be researched because of all the toxic waste produced by uranium. It has been a great tool for both productive and destructive matters, but it is time that the world stops all projects that need this element. Uranium is dangerous, and when placed in the wrong hands, it can be very deadly.

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Student Research Aban Nesta, Flickr Photo Sharing Brain

Alzheimer’s Disease

An Overview Lily McCarthy Alzheimer’s disease (AD) causes various parts of the brain to undergo progressive decay and atrophy, which results in memory loss and a gradual decline in cognitive functioning.1 First described by Alois Alzheimer in 1906 as an “unusual disease of the cerebral cortex,” AD is now the most prevalent type of dementia today; it is estimated to afflict over 5.1 million individuals in the United States alone and 36 million more people worldwide.2 Underlying pathological mechanisms induce a mélange of neurofibrillary tangles and amyloid plaques, which lead to massive neuronal deaths and synapse deformations. As the brain’s mass decreases, fissures and grooves lining the cerebral cortex widen substantially.3 Damage to the brain typically commences about ten years before the occurrence of identifiable symptoms; this period of time is known as the preclinical stage.4 Mild, moderate, and severe stages are terms used to address different phases of the disease and correlate to many different cognitive and behavioral abnormalities.5 Symptoms of AD include, but are not limited to, disorientation and a lack of spatial understanding, difficulty speaking, reading and writing, and the impaired ability to make judgments and formulate decisions. In the later stages of AD, patients often exhibit dramatic personality and behavioral changes, thus instances of depression, aggressiveness, delusions, and a tendency to wander are also common.6 22

Neuronal degeneration is a multi-step process, starting in the periphery of the brain when synapses begin to deteriorate and fail to function properly. The distribution of organelles and components of the cytoskeleton to neurons, a term used to describe nerve cells, precedes the ensuing deterioration of axons and dendrites. Neurofibrillary tangles are then substituted for nerve cells as the latter structures are progressively destroyed.7 These tangles are made out of clusters of fibers that contain the tau protein, located on the interior of neurons. The addition of an extra phosphate to this protein inhibits the protein’s normal binding capabilities. As a result, composites of the molecule aggregate together in regions of the brain and impede normal intercellular functioning.8 Amyloid plaques, also seen in the clinical presentation of the disease, are composed of insoluble clusters of beta-amyloid (Aβ), or isolated portions of the larger amyloid precursor protein (APP).9 APP is primarily found in the synapses, or gaps, between neurons and is located on chromosome 21.

The substitution of the amino acid isoleucine for valine on the APP gene results in structural modifications of protein components.10 Longer peptides that tend to accumulate and bind together are produced, interfering with neuronal connections.11 Many researchers are investigating ways to remove excessive Aβ from the brain in order to minimize the disruption of neurological functioning that is concomitant

Student Research with the onset of AD.12 A popular theory within this field of research today, known as the “amyloid cascade hypothesis,” holds that the aggregation of β-amyloid in the brain induces the development of senile plaques and neurofibrillary tangles.13 However, recent evidence suggests that the two events are actually independent from each other.14 Furthermore, these pathological lesions may not cause AD but could actually result from the disorder itself. Thus, the molecular origins of AD and the intricate steps involved in APP metabolism are not clearly understood and further investigation is required.

It is important to note that certain peptides derived from the non-mutated form of APP may in fact work to support neurological functioning. Studies indicate that the soluble amyloid precursor protein (sAPP) potentially works to contribute to neuronal growth and protein regulation.16 Amyloid beta peptide may also assist neurons as they change overtime, playing a vital role in neurological plasticity.17 Although the precise cause of AD is still unknown, it is postulated that the combination of genetic, environmental, and lifestyle components contribute to its onset.8 In addition, changes associated with the normal aging process such as atrophy, inflammation, free-radicals, and mitochondrial dysfunction can lead to the damages connected to AD.19 Although, this connection is still controversial as certain research studies found that aging and AD may be distinct processes without similar origins or agencies.20 Hereditary influence in AD is widely debated; however, conclusive evidence indicates that a patient’s genetic makeup can determine his or her susceptibility to the disease.

Certain risk genes in the apolipoprotein E-e4 family such as APOE-e4, 3, and 2 affect an increase in the probability of developing AD and correlates (it cannot yet be given the term

accounts by definition) to 20 to 25% of late onset AD cases.21 Less than 5% of patients with AD have certain genetic mutations that guarantee a patient will contract AD.22 These mutated variants, known as deterministic genes, include APP, Presenilin 1 (PS-1), and Presenilin 2 (PS-2).23 Treatment options such as donepezil, rivastigmine, and galantamine are often prescribed to patients with mild to moderate AD; memantine is typically used for more severe cases.24 These medications block the secretion of certain neurotransmitters or interfere with enzyme activity, thereby maintaining the processes of thought and verbal communication, memory storage, and other aspects of behavior for a period of time. However, as of yet, no terminal cure for the disease exists.25 Preventative measures should nevertheless be taken to minimize one’s likelihood of developing the disease. Active scientific investigations exploring numerous potential curative measures like cognitive and immunization therapy, antioxidants, physical activity, and other connected cardiovascular and diabetes treatments are currently underway.26 I am currently working on a research study focused on AD that aims to harness the advantages offered by magnetic resonance imaging and utilize them in a clinical setting.

Although the study is still in its early stages, researchers involved hope to determine whether the deterioration of the hippocampus, a neurological structure involved in memory consolidation, can be used to predict associated rates of cognitive and functional decline in AD patients. Evidence of such correlations may potentially serve to improve diagnostic procedures and the course of treatment for individuals with dementia. This study is based at Mount Sinai and is part of a body of related work sponsored by the institution’s Alzheimer’s Disease Research Center.

Combination of two brain diagrams in one for comparison. In the left normal brain, in the right brain of a person with Alzheimer’s disease Garrondo, Wikimedia Commons

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Student Research

Exoplanets

1

2 3

(1) An exoplanet with planetaty rings of dust and other particles; “Ron Miller/NASAblueshift” (2) Scientists recently discovered two giant gas planets in a cluster of stars known as the Beehive Cluster. Each of the planet orbits a bright sun-like star, such as the sun showed on the right of the drawing; “NASA/JPL-Caltech, Wikimedia Commons” (3) This artist interpretation depicts the variety of topography which probably makes up a series of unknown exoplanets; “NASA/JPL-Caltech/R. Hurt (SSC-Caltech), Wikimedia Commons”

By Cassandra Kopans-Johnson 2 Until recently, scientists believed that there were only eight planets in the universe, that our solar system was a rare phenomenon. In 1994, Dr. Alexander Wolszczan discovered the first evidence of exoplanets, planets outside of our solar system. Since the 2009 launch of the Kepler Spacecraft whose mission was to find Earth-like planets, the number of known exoplanets has spiked to over 4,000. Exoplanets are hard to detect because they are extremely small in comparison to their parent stars. As a result, their parent stars outshine them, making them practically invisible to us.

Despite the apparent difficulty in finding exoplanets, there are several techniques that scientists use to detect them.

Among them, I have personally used the transiting technique.

When a planet orbits around its parent star, there is a period of time when the planet crosses in front of the star so that it is in between its parent star and Earth. During this time, which is known as a transit, the planet blocks a small amount of the star’s emitted light. This blockage is represented in data as a dip in the star’s emitted light. Depending on the shape of the dip and the regularity of it, one can infer the existence of an exoplanet.

In order to take a transit, one must record the star’s light before, during, and after the transit. From this recorded data, a person can deduce information concerning the exoplanet’s composition. Every element has an atomic spectrum. For example, as the electrons of a star’s atoms become excited, they move to a higher energy level. However, the electrons cannot stay at a high energy level forever. When they move down to their ground state, photons, or particles of light, are emitted with the same amount of energy as the energy difference

24

between the energy levels that the electrons occupied. All of these emitted photons make up a spectrum of light, called the emission spectrum, unique to its corresponding element.

When the planet goes through its transit, some of the star’s light passes through its atmosphere. The photons from this light excite the atoms in the atmosphere and cause the electrons to move to higher energy levels. When the electrons return to their ground states, photons are emitted. However, these photons do not know the path of the original photons.

Therefore, these photons are not represented in the spectrum we receive because they traveled off in different directions.

This process results in absorption lines, black lines or gaps that appear in the emission spectrum. A scientist then compares the spectrum with absorption lines to the previous spectrum. He or she then deduces the planet’s atmospheric composition. The possibilities of a planet’s composition are endless. For example, one exoplanet is known to have a silicon based cloud structure that rains molten glass daily.

Another planet, whose parent star is primarily composed of carbon, is believed to have a surface of diamond.

Whenever I looked into a telescope and opened the dome to the night sky, I was always amazed by the cosmic beauty displayed above my head. Whether I am communicating with the International Space Station, walking around observatories, talking with other astronomers, or simply looking up, I am constantly filled with an awareness of the infinite possibilities of what is out there and the privilege we have in being able to see the stars every night.

References The Discovery of the Dreaming Process Jasmine Katz

Dream Moods. “History and Background of Dreams.” Dream Moods. Last modified September 5, 2013. Accessed November 16, 2013. http://www.dreammoods.com/ dreaminformation/history.htm.

Lambert, Katie. “How Lucid Dreaming Works.” HowStuffWorks.

Last modified May 21, 2008. Accessed November 16, 2013. http://science.howstuffworks.com/life/inside-themind/human-brain/dream2.htm.

Orbringer, Lee Ann. “How Dreams Work.” HowStuffWorks. Last modified January 27, 2005. Accessed November 16, 2013. http://science.howstuffworks.com/life/inside-themind/human-brain/dream2.htm.

Sandford, Maggie Ryan. “5 Actual Facts About the Science of Dreams.” Mental Floss. Last modified June 17, 2013.

Accessed November 16, 2013. http://mentalfloss.com/ article/51228/5-actual-facts-about-science-dreams.

Turner, Rebecca. “A History of Dream Research.” World of Lucid Dreaming. Accessed November 16, 2013. http://www. world-of-lucid-dreaming.com/dream-research.html.

Beta-amyloid May Cause Alzheimer’s at the Synapse Mehr Suri Alzheimer’s Association. “What Is Alzheimer’s?” Alzheimer’s Association. Accessed December 6, 2013. http://www. alz.org/alzheimers_disease_what_is_alzheimers.asp.

Goldman, Bruce. “Scientists reveal how beta-amyloid may cause Alzheimer’s.” Stanford School of Medicine. Last modified September 19, 2013. Accessed December 6, 2103. http://med.stanford.edu/ism/2013/september/ alzheimers.html.

Advances in Social and Cognitive Disorders Nicole Kaiser

“Are Schizophrenia and Autism Close Relations?.” Science Daily. Last modified October 23, 2012. Accessed November 9, 2013. http://www.sciencedaily.com/ releases/2012/10/121023124524.htm.

Charlton Cheung and Kevin Yu. “Autistic Disorders and Schizophrenia: Related or Remote? An Anatomical Likelihood Estimation.” Plos One. Last modified August 18, 2010. Accessed

November 9, 2013. http://www.plosone.org/article/ info%3Adoi%2F10.1371%2Fjournal.pone.0012233.

“Study: Depression, Autism and Schizophrenia Share Genetic Links.” NPR. Last modified March 1, 2013. Accessed November 9, 2013. http://www.npr. org/2013/03/01/173271247/-study-depression-autismand-schizophrenia-share-genetic-links.

Restless Genes Sabrina Lautin

Dobbs, David. “Restless Genes.” National Geographic, January 2013, 45-57. Accessed November 9, 2013. http://natgeo.galegroup.com.ezy.hmsl.sirsi.net/natgeo/ archive?u=nysl_me_horman&prodId=NGMA.

Does the Secret of Immortality Lie in Telomeres?

Amory Tillinghast-Raby

Kravetz, Dennis. “How and Why We Age: The Power of Telomeres and Telomerase.” Huffington Post. Last modified July 25, 2013. Accessed November 16, 2013. http://www.huffingtonpost.com/dennis-kravetz/telomeresaging_b_3618321.html.

Pearson, James A. “The Strange Immortality of Dmitry Itskov and His Avatars.” Medium. Last modified June 9, 2013.

Accessed November 16, 2013. https://medium.com/whati-learned-today/121cf69fd14b.

2045. “2045 Initiative.” 2045. Accessed November 16, 2013. http://2045.com.

Mad Cow Disease Alexander Karpf

Barria, Marcelo A., et al. “De Novo Generation of Infectious Prions In Vitro Produces a New Disease Phenotype,” PLOS, May 15, 2009, accessed November 14, 2013, DOI:10.1371/journal.ppat.1000421.

“The Basics of Mad Cow Disease,” Brain and Nervous System Health Center, accessed November 14, 2013, http:// www.webmd.com/brain/mad-cow-disease-basics.

“Bovine Spongiform Encephalopathy,” US Food and Drug Administration, last modified April 16, 2013, accessed November 14, 2013, http://www.fda.gov/ animalveterinary/guidancecomplianceenforcement/ complianceenforcement/ bovinespongiformencephalopathy/default.htm.

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Brown, David. “The ‘Recipe for Disaster’ That Killed 80 and Left a £5bn Bill,” The Telegraph (London, UK), October 27, 2000, UK News, accessed November 14, 2013, http://www.telegraph.co.uk/news/uknews/1371964/Therecipe-for-disaster-that-killed-80-and-left-a-5bn-bill. html.

“Creutzfeldt-Jakob Disease in the UK,” The National CJD Research and Surveillance Unit, accessed November 14, 2013, http://www.cjd.ed.ac.uk/documents/figs.pdf.

“Fact Sheet: Variant Creutzfeldt-Jakob Disease,” Centers for Disease Control and Prevention, last modified February 22, 2013, accessed November 14, 2013, http://www.cdc. gov/ncidod/dvrd/vcjd/factsheet_nvcjd.htm.

Freudenrich, Craig. “How Mad Cow Disease Works,” HowStuffWorks, accessed November 14, 2013, http:// science.howstuffworks.com/zoology/all-about-animals/ mad-cow-disease4.htm.

Meikle, James. “Mad Cow Disease: A Very British Response to an International Crisis,” The Guardian (London, UK), April 25, 2012, UK News, accessed November 14, 2013, http://www.theguardian.com/uk/2012/apr/25/mad-cowdisease-british-crisis.

Murphy, Frederick A. “Mad Cow Disease: The BSE Epidemic in Great Britain,” The Official Mad Cow Disease Home Page, accessed November 14, 2013, http://mad-cow. org/~tom/vet_interview.html.

“Prion (Infectious Agent),” Encyclopedia Britannica, accessed November 14, 2013, http://www.britannica.com/ EBchecked/topic/477113/prion.

Valleron, Alain-Jacques et al. “Estimation of Epidemic Size and Incubation Time Based on Age Characteristics of vCJD in the United Kingdom,” Science, October 20, 2001, [Page #], accessed November 14, 2013, http://www. sciencemag.org/content/294/5547/1726.abstract.

Vogel, Gretchen. “Prusiner Recognized for Once-Heretical Prion Theory,” Science Magazine, accessed November 14, 2013, http://www.sciencemag.org/site/feature/data/ prusiner/214.xhtmlP.

How Cocaine Kills Jenny Wang

Elsevier. “Chronic Cocaine Use Triggers Changes in Brain’s Neuron Structure.” Science Daily. Last modified May 9, 2012. http://www.sciencedaily.com/ releases/2012/05/120509165353.htm.

———. “Cocaine Exposure in the Womb: The Brain Structure Is Intact, Development Is off Track.” Science Daily. Last modified September 25, 2013. http://www.sciencedaily. com/releases/2013/09/130925091738.htm.

Mayes, Linda, Kenneth Rando, Tara Chaplin, Rajita Sinha, and Marc Pontenza. “Prenatal Cocaine Exposure and Gray Matter Volume in Adolescent Boys and Girls: Relationship to Substance Use Initiation.” Biological Psychiatry, 2013.

“Possible Cocaine Addiction Trigger Uncovered: Protein Linked to Mental Retardation May Be Controlling Factor in Drug’s Effect in the Brain.” Science Daily. Last modified August 16, 2010. http://www.sciencedaily.com/ releases/2010/08/100815162122.htm.

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Smith, Jones, Williams, Bullmore, Robins, and Ersche.

Overlapping Decline in Orbitofrontal Gray Matter Volume Related to Cocaine Use and Body Mass Index. N.p.: n.p., 2013. http://www.ncbi.nlm.nih.gov/ pubmed/23927455.

Cell Theory Jacob Hoglund

Alice Downing Polk, “The Cell Theory,” in Bios (n.p.: Beta Beta Beta Biological Society, 1934), 5:87.

John S. Karling, “Schleiden’s Contribution to the Cell Theory,” in The American Naturalist (n.p.: University of Chicago Press, 1939), 73:519.

L. Wolpert, “Evolution of the Cell Theory,” in Philosophical Transactions: Biological Sciences (n.p.: Royal Society, 1995), 349:227.

Louis Pasteur, Science, vol. 2, On the Germ Theory (n.p.: American Association for the Advancement of Science, 1881).

Discovering Dark Energy Lauren Hooda

“Dark Energy, Dark Matter,” National Aeronautics and Space Administration, last modified April 30, 2013, http:// science.nasa.gov/astrophysics/focus-areas/what-is-darkenergy/.

“The 2011 Nobel Prize in Physics - Press Release,” The Official Website of the Nobel Prize, last modified October 4, 2011, accessed November 10, 2013, http://www.nobelprize.org/nobel_prizes/physics/laureates/2011/press. html.

“Dark Energy,” Large Synoptic Survey Telescope, http://www. lsst.org/lsst/public/dark_energy.

“The 2011 Nobel Prize,” The Official Website of the Nobel Prize.

Nolah Taylor Redd, “What is Dark Energy?,” Space, last modified May 1, 2013, http://www.space.com/20929-dark-energy.html.

Richard Panek, “Dark Energy: The Biggest Mystery in the Universe,” Smithsonian, last modified April 2010, http://www.smithsonianmag.com/science-nature/ Dark-Energy-The-Biggest-Mystery-in-the-Universe. html?c=y&page=2.

Special Relativity Came First Ajay Shyam

Nola Taylor Redd, “Einstein’s Theory of General Relativity,” Space.com, last modified September 18, 2012, http:// www.space.com/17661-theory-general-relativity.html.

“Einstein’s General Theory of Relativity,” YouTube, video file, 3:01, posted by Razin Shaikh, August 17, 2011, http:// www.youtube.com/watch?v=fEZupmpTcOU. Richard W. Pogge, Prof., “Real-World Relativity: The GPS Navigation System,” Astronomy 162: Introduction to Stars, Galaxies, and the Universe, last modified March 17, 2006, http://www.astronomy.ohio-state.edu/~pogge/ Ast162/Unit5/gps.html.

Clara Moskowitz, “’Einstein’s Planet’: New Alien World Revealed by Relativity,” Space.com, last modified May 13, 2013, http://www.space.com/21126-alien-planet-einstein-relativity.html.

The Enigma of Gravity: From Aristotle to Newton

Jenna Karp

Themos Kallos, “A Brief History of Gravity,” The University of Southern California: Kallos, http://www-scf.usc. edu/~kallos/gravity.htm.

Mary Bellis, “Galileo Galilei,” About.com Inventors, http://inventors.about.com/od/gstartinventors/a/Galileo_Galilei. htm.

Hobie Thompson and Sarah Havern, “The History of Gravity,” Stanford University: The Thompson Homepage, http:// www.stanford.edu/~buzzt/gravity.html.

“Physics I: Classical Mechanics,” MIT OpenCourseWare, http:// ocw.mit.edu/courses/physics/8-01sc-physics-i-classical-mechanics-fall-2010/.

Discovering the Kuiper Belt: Home of Comets, Rocks, and Pluto Abigail Zuckerman Jewitt, David. “Kuiper Belt.” UCLA. Accessed November 10, 2013. http://www2.ess.ucla.edu/~jewitt/kb.html.

NASA. “Gerard Kuiper.” NASA. Accessed November 10, 2013. http://solarsystem.nasa.gov/people/profile. cfm?Code=KuiperG. NASA. “Kuiper Belt and Oort Cloud: Read More.”

NASA. Accessed November 10, 2013. http:// solarsystem.nasa.gov/planets/profile. cfm?Object=KBOs&Display=OverviewLong.

NASA. “New Horizons: Launch.” NASA. Accessed November 10, 2013. http://www.nasa.gov/mission_pages/newhorizons/ launch/index.html#.UoAxoBZ9dc-.

The Accidental Discovery of Gunpowder Jason Ginsberg

Carr, Karen, Dr. “Gunpowder in Ancient China.” History For Kids. Last modified March 30, 2012. http://www. historyforkids.org/learn/war/gunpowder.htm.

Helmenstein, Anne Marie, Phd. “Gunpowder Facts and History.” About. http://chemistry.about.com/od/ historyofchemistry/a/gunpowder.htm.

K., S. “Discovery of Gunpowder.” Buzzle. Last modified September 29, 2011. http://www.buzzle.com/articles/ discovery-of-gunpowder.html.

Summers, Vincent. “Gunpowder - the Chemistry behind the Bang.” Yahoo. Last modified September 30,2010. http://voices.yahoo.com/gunpowder-chemistry-behindbang-6884202.html?cat=15.

Whipps, Heather. “How Gunpowder Changed the World.” Live Science. Last modified August 6, 2008. http://www. livescience.com/7476-gunpowder-changed-world.html.

Ununpentium’s Discovery and Why We Should Care Maddie Bender

Forsberg, Ulrika. “Existence of new element confirmed.” Lund University. Last modified August 27, 2013. Accessed November 13, 2013. http://www.lunduniversity.lu.se/ o.o.i.s?id=24890&news_item=6082.

Lemonick, Michael. “Ununpentium, the Newest Element.” The New Yorker. Last modified August 31, 2013. Accessed November 13, 2013. http://www.newyorker.com/online/ blogs/elements/2013/08/unumpentium-the-new-artificialelement.html.

“New superheavy elements can be uniquely identified.” GSI.

Last modified August 29, 2013. Accessed November 13, 2013. http://www.gsi.de/en/start/news/detailseite/ datum/2013/08/29/neue-superschwere-elementekoennen-direkt-nachgewiesen-werdenhtm?nr=%2Fproc %2Fself%2Fenvi&cHash=6fcea83acfdffae78851caee2 50582d6.

Prostak, Sergio. “Ununpentium: Scientists Confirm Existence of Element 115.”Sci-News.com. Last modified August 28, 2013. Accessed November 13, 2013. http://www.sci-news.com/physics/scienceununpentiumelement-11501340.html.

Rethinking the Role of Uranium Veer Sobti

http://web.ead.anl.gov/uranium/guide/facts/. http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/ becquerel-bio.html Hanne Anderson, “Physics: Radioactivity,” in Scientific Thought: In Context, ed. K. Lee Lerner and Brenda Wilmoth Lerner, In Context Series (Detroit, MI: Gale, 2009), 2:[Page 844-54], accessed May 6, 2013, World History in Context.

Conservation Councli of South Australia, http://www.ccsa.asn.au/ nuclearsa/b1.html.

Wikipedia, http://en.wikipedia.org/wiki/Uranium.

Exoplanets Cassandra Kopans-Johnson

“Exoplanet History - From Intuition to Discovery.” Jet Propulsion Laboratory California Institute of Technology:PlanetQuest: The Search for Another Earth.

Accessed October 24, 2013. http://planetquest.jpl.nasa. gov/page/history.

Alzheimer’s Disease: An Overview Lily McCarthy

“Alzheimer’s Disease Fact Sheet,” National Institute on Aging, last modified September 2012, accessed August 2, 2013, http://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-fact-sheet.

“Alzheimer’s Disease Fact Sheet,” National Institute on Aging; Nicole L. Batsch and Mary S. Mittelman, “Overcoming the stigma of dementia,” Alzheimer’s Disease International: World Alzheimer Report 2012, 2012, 5, PDF. “Alzheimer’s Disease,” Mayo Clinic, accessed August 2, 2013, http://www.mayoclinic.org/alzheimers-disease/.

Robert Stahl et al., “White Matter Damage in Alzheimer Disease and Mild Cognitive Impairment: Assessment with Diffusion-Tensor MR Imaging and Parallel Imaging Techniques,” Radiology, May 2007, accessed August 2, 2013, doi:10.1148/radiol.2432051714.

“Alzheimer’s disease,” in Gale Encyclopedia of Medicine (The Gale Group, 2008), accessed August 2, 2013, http:// medical-dictionary.thefreedictionary.com/Alzheimer%27s+disease.

“APP.” Genetics Home Reference. Last modified July 29, 2013.

Accessed August 4, 2013. http://ghr.nlm.nih.gov/gene/ APP. R. A. Armstrong, “The Pathogenesis of Alzheimer’s Disease: A Reevaluation of the “Amyloid Cascade Hypothesis”,” International Journal of Alzheimer’s Disease, February 7, 2011, 1, PDF. 27