Stop Insulting Anglerfish Sex

http://www.photolib.noaa.gov/htmls/expl5923.htm

A deep sea anglerfish called a goosefish and is a member of the Lophiidae family – Sladenia remiger.  Image Credit: NOAA Okeanos Explorer Program, INDEX-SATAL 2010

You may have seen the anglerfish sex video floating around the Internet recently, with titles like “The worst sex in the world is anglerfish sex, and now there’s finally video.” While the video is worth a watch, I think most behavioral ecologist would beg to differ with the main assertion: there’s a lot of bad sex in the animal kingdom.

Why is anglerfish sex supposedly so terrible? A male anglerfish bites a females when he finds her, and then hangs onto her for the rest of his life, essentially turning into a living sac of sperm. But hey, at least he’s alive. In contrast, some species of male widow spiders somersault into the mouths of females as they mate, impaling themselves on their mates’ fangs. It sounds like an evolutionary enigma–why would an organism ever willingly sacrifice itself?–but turns out that that self-sacrifice can increase a male’s chances of fathering the female’s offspring.

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The female bed bug (the larger of the two) is traumatically inseminated by the male (bottom) through her abdomen.

Traumatic insemination” is another great example of not-so-great sex. In this case, bed bug females are the ones getting royally screwed, because traumatic insemination is a nice way of saying males stabbing females through the abdomen with their penises. The sperm then travels through the female’s hemolymph (the insect equivalent of blood), until reaching the ovaries and fertilizing the eggs. Males mate with all available females, because the last male to mate with any given female has the best chance of fathering her offspring. However, females who are subjected to these multiple matings pay a high cost: they have shortened lives and reduced reproductive output, because they have to allocate energy to healing the wounds and dealing with any resulting infections.

People often assume that two organisms mating with one another have the same “goals.” After all, both males and females are presumably invested in having as many healthy offspring as possible. But this is only true up to a certain point. Female widow spiders don’t need males to remain alive after mating, and in fact gain an advantage from eating the male (a ready source of nutrients that will help her with her next clutch!). In contrast, male widow spiders obviously benefit from not being eaten, and instead living to mate another day. Similarly, mating multiple times via traumatic insemination is costly to female bed bugs, who only need enough sperm to fertilize their eggs, while male bedbugs benefit from mating as many times as possible.

These are examples of what biologists call sexual conflict. While the source of conflict is obvious in the widow spiders’ and bed bugs’ cases, sexual conflict occurs anytime male and female genetic interests don’t align. In fact, the only time there is absolutely no potential for conflict is when males and females have exactly the same lifetime reproduction, so that each is equally invested in all of their shared offspring, with no opportunities for having offspring with other partners. In contrast, conflict can arise whenever one sex has the opportunity to improve their chances of having more, or better, offspring. This can happen in many different ways, such as: eating your partner, mating multiple times with the same partner, or even mating with multiple partners.

As a result, sexual conflict isn’t likely in anglerfish, at least those species which only have one mate for their entire lives. Although there are genera of anglerfish where females can have up to 8 males hanging off of her! So there’s potential for sexual conflict there, since the males will presumably compete to father her offspring and could do so in ways that are harmful to the female. However, anglerfish are incredibly hard to study because they generally occur in the deep sea. Frankly, male anglerfish have way more going for them than you might’ve ever thought–keep that in mind next time someone’s making fun of them.

 

Peer edited by Karen Setty.

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Mimicking Electric Eels to Provide Power to Medical Devices

https://www.flickr.com/photos/ryanready/4593249712

The electric organ of eels has inspired researchers to develop biocompatible power sources that could be used to power medical devices

While the shock of an electric eel sounds like more of a medical nightmare than a fortunate asset, researchers at the University of Michigan were inspired to simulate the power of these slick creatures in hope of creating power sources for a variety of medical devices. With society’s heavy reliance on technology, it’s not surprising that medical treatments have continued to rely more and more on electrical devices including wearable and implantable sensors, pacemakers, and prosthetics. Just as with any piece of technology, these devices require an electrical power source. However, medical devices face the added requirement of being biocompatible, meaning they must function safely and effectively in the human body. Eel-inspired power sources may achieve this goal of being biocompatible while supplying medical devices with the electricity they need to function.  

The inspirational efficiency with which an eel uses its electrical shock, to help catch prey and protect itself against predators, is the result of natural selection. Electrophorus electricus, know commonly as a knifefish or an electric eel, possesses an electric organ that extends through the back 80% of its body. The organ contains parallel stacks of special cells called electrocytes. When a situation arises that warrants a shock from the eel, its nervous system generates an electric current by activating thousands of electrocytes at the exact same time. As the cells are activated, the positively charged sodium and potassium ions, in and around the cells, move toward the head of the eel. The movement of these ions allows each of the electrocytes to act like small batteries. The activated end that lost the ions has a negative charge, while the opposite side that acquired the sodium and potassium ions carries a positive charge. The battery-like cells can each generate a small, innocuous voltage (less than that of a AAA battery). But when combined, the eel’s shock can be over 600 volts! For reference, a US household outlet supplies 120 volts. While a significant portion of this voltage is lost to the water around the eel, its prey or attacker will still get a nasty shock.

https://commons.wikimedia.org/wiki/File:Herzschrittmacher_auf_Roentgenbild.jpg

By developing this work further, researchers hope to successfully use their artificial electric organ to run medical devices like pacemakers

The University of Michigan team has successfully created an artificial electric organ that can potentially be used by humans to power devices. To make the electrical power supply biocompatible, it was necessary to efficiently mimic the features of the eel’s electric organ. This was achieved by preparing hydrogel membranes that could be layered to replicate the structure of the organ. To mimic the movement of ions in and out of the cells, the hydrogels were filled with dissolved table salt, which is made of sodium and chlorine ions. Half of the cells were designed to allow only positively charged sodium ions out and the other half would only allow negatively charged chlorine ions to exit. The gels containing the salt water were alternated on the membrane sheet with gels containing pure water, which allows the sodium and chlorine to move in opposite directions. This flow of ions generates an electric charge with an electrical potential of 110 volts. While this voltage is less than that of the inspirational eel organ, in its current state the artificial organ may be sufficient to power some low-power devices.

Though pleased with the engineering of a potentially biocompatible power source, the researchers acknowledge that there are plenty of opportunities to improve its design. By increasing the efficiency of these artificial organs, researchers believe their utility will increase, as they will become more suitable for use in combination with implantable devices.

Peer edited by Erika Van Goethem.

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Science Communication, Advocacy and the Federal Budget

https://www.flickr.com/photos/library_of_congress/8470008043

Scientific societies, such as ASBMB, provide opportunities for trainees to travel to Washington, D.C. and meet with policymakers.

Recently, the federal budget for the fiscal year (FY) 2019 (beginning October 1st, 2018) was released. Shockingly, the initial plan called for brutal cuts to basic research funding agencies—slashing the budget of the National Institutes of Health (NIH) and the National Science Foundation (NSF) by 27% and 29%, respectively. While Congress subsequently lifted spending caps to compensate for these losses, the budgets of both the NIH and NSF will now remain stagnant at levels for FY2017.

Although catastrophic funding losses have been avoided, these flat budgets are still worrisome. When adjusted for inflation, a stable budget equates to a decrease in funding.  Furthermore, three health research institutes currently located in the Agency of Healthcare and Human Services and the CDC will be terminated and their successors will be created within the NIH. The relocation of these institutes without an increase in NIH funding will further strain the budget.

Numerous scientific societies have responded with criticism to the federal government’s budget proposal. A statement from The Society for Neuroscience (SfN) highlighted the public’s support for scientific research funding and emphasized that adequate funding is critical to combat devastating diseases, such as Alzheimer’s. Likewise, a press release from the American Society for Biochemistry and Molecular Biology (ASBMB) expressed concern regarding America’s ability to lead in science and innovation amidst stagnant funding.

Educating elected officials on the importance of scientific research is a key focus of scientific societies. ASBMB sponsors an opportunity for graduate students and postdocs to travel to the capital and meet with Congress through their annual Hill Day. Societies also encourage local action. For example, the American Society for Cell Biology (ASCB) compiles an advocacy toolkit to guide members through the process of contacting local representatives, scheduling meetings and organizing lab tours. On the UNC campus, the Science Policy Advocacy Group (SPAG) is a resource for graduate students and postdocs to gain skills in science communication and advocacy through outreach events, workshops and seminars.     

At the core of science advocacy is the ability to communicate why science is necessary. While the significance of developing new cancer therapies is clear, the importance of basic science research is still often misunderstood. Basic science research is often described as “curiosity-driven” and asks fundamental questions such as: “How do cells move?” This basic research provides a thorough understanding of cellular processes that is critical for later medical innovations. In the 1990s, Yoshinori Ohsumi observed an unusual structure in yeast cells when he starved them. His work in yeast was essential for uncovering the mechanism behind autophagy, a recycling pathway in the cell. Today, researchers know that defects in autophagy result in cancer, Parkinson’s Disease and Type 2 Diabetes, and Ohsumi was awarded the Nobel Prize in Medicine in 2016.

Ohsumi’s story demonstrates that breakthroughs in basic science are critical for breakthroughs in medicine. Yet, proper funding must be secured before further innovations in either field can occur. As a result, it is critical to create a culture that both understands and values scientific research.

Peer edited by Kelsey Miller.

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Space Travel is Possible with the Sound of Light

https://commons.wikimedia.org/wiki/File%3ASpace_travel_195807.jpg

Optical communication devices may be the first step in space travel.

Technology moguls dream of human colonies on other planets. For this dream to become reality, science needs to develop new spacecraft capable of transporting people and cargo to the outer reaches of our galaxy. Another challenge is how to find a route to these other planets.  We can’t just use Google Maps. Space travelers would have to navigate around comets, space debris, or orbiting planets.  Complex models and communications developments would be needed to move through galaxies safely and quickly.

Light-based communication is desirable because it can transmit more data per second while producing significantly less heat. This means that less energy is spent cooling equipment, making the it more efficient to run compared to conventional electron-based communication.

Similar to how electronic devices maneuver electrons through a computer chip, photonic devices maneuver light for optical communication. Normally, a magnetic field is required to produce a change in optical properties necessary for one-way light propagation. However, the size of magnets are too large to be incorporated efficiently into nanoscale devices. To address this problem, University of Illinois researchers created a nanoscale photonic device called an optical isolator, using sound waves instead of magnets for one-way light guidance.

Erika Van Goethem

Cartoon of optical device

The optical isolator device is made from aluminum nitride. A radio frequency driver (RF driver) generates a radio frequency signal that is used to create a sound wave. The RF signal is applied to an IDT, consisting of two interlocking comb-shaped arrays of metallic electrodes that convert electrical signals into surface sound waves. The grating couplers allow the light, generated by a laser, to enter into the device from one direction.  The light travels along the optical waveguides and is transferred from one optical band to another, interacting with the previously converted sound waves. Light is able to pass through the device when the shape of the light wave matches the shape of the sound wave going in the same direction. However, light waves going in the opposite direction of sound waves are absorbed by the device and are unable to pass through, thus maintaining the one-way propagation of light.

This new device allows for a more reliable and sensitive transfer of information that can be used in devices such as atomic clocks and GPS.  Such innovations may be the first step toward developing deep space navigation and travel.

Peer edited by Portia Flowers.

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Cloned Monkeys: Another Human Creation

http://english.cas.cn/head/201801/t20180123_189488.shtml Image credited to Qiang Sun and Mu-ming Poo, Institute of Neuroscience of the Chinese Academy of Sciences

First cloned none-human primates: Zhong Zhong and Hua Hua (Image credited to Qiang Sun and Mu-ming Poo, Institute of Neuroscience of the Chinese Academy of Sciences)

Cloned primates are here! Over three decades have passed since the birth of Dolly, the sheep, scientists have now tackled cloning mammals that are even closer to us on the evolutionary tree: macaque monkeys. What does this mean for a society that witnesses dramatic changes day by day: computers are outperforming doctors in calling out heart abnormalities in patients; 3D-printed organs are bringing us one step closer to tissue restoration; genome sequencing has become an online product easily available for anyone curious about their ancestry, bodybuilding, or just simply wine tastes. Breakthroughs in science and technologies are so prevalent in our life that by now, we probably shouldn’t be surprised by any new discovery. Yet when the two cute, little, cloned monkeys were born, the whole world was, once again, shaken.

Published in Cell on January 24th, 2018, a study from a group of scientists in China reported their methods in generating two non-human primates that are genetically identical. To clone the two identical macaque monkeys, the scientists applied Somatic Cell Nuclear Transfer, the same method that generated Dolly in 1996. The key idea behind cloning is that a new organism, be it sheep or monkey, is generated without sexual reproduction. Asexual reproduction is not as uncommon as one would think, plenty of plants do so. For example, Bryophyllum shed plantlets from the edge of the leaves to produce new plants. Some insects, such as ants and bees, also exploit asexual reproduction to clone a huge working class army. Since asexual reproduction is essentially an organism duplicating itself, the offsprings are all genetically identical. Evolution, however, doesn’t favor asexual reproduction as identical offsprings don’t prevail in a fast changing environment. On the other hand, sexual reproduction combines different sperms and eggs to create diverse offsprings, of which some may survive. To combat challenges from the mother nature, higher organisms, such as mammals, almost exclusively reproduce sexually. This is why a cloned monkey, an anti-evolution human creation, is mind blowing.

https://commons.wikimedia.org/wiki/File:Kalanchoe_plantlets.JPG

The succulent, genus Kalanchoe, uses asexual reproduction to produce plantlets.

To clone mammals, scientists came up with the idea of transferring the nucleus of a somatic cell to an enucleated egg (an egg that lacks nucleus). Unlike  germ cells (sperm and eggs), somatic cells refer to any cells that don’t get passed onto the next generation. These cells have the full genome of an organism that is split equally in germ cells during sexual reproduction. Carrying half of the genome, sperm and egg need to fuse their genetic materials to make one viable embryo. Technically, the nucleus of a somatic cell holds all the genetic information an organism needs. Thus, by inserting the somatic cell nucleus into an egg, scientists could generate a functional embryo. But why not into a sperm? Evolution has trimmed mammalian sperm tremendously so that it can accomplish its only job better: swim faster to fertilize the egg. As a result, not much other than the sperm’s genetic information is incorporated into the fertilized egg and the embryo relies on the cellular machinery from the egg to finish development. Using this technology, the scientists generated over 300 “fertilized” embryos. Of these embryos, 260 were transferred to 63 surrogate mothers to finish developing. 28 surrogate mothers became pregnant, and from those pregnancies, only 2 healthy monkey babies were born. Although they were carried by different surrogate mothers, every single piece of their genetic code is the same as the the somatic nucleus provider, a real-life demonstration of primate-cloning. Followed by millions of people since their debut to the world, these two macaque superstars are the living samples of a revolutionary breakthrough in our science and technologies.

 

Despite the extremely low success rate, this technology erects another monument in the history of mankind’s creations. Carrying identical genetic information, cloned monkeys like these two can be a very powerful tool in biomedical research and diseases studies. Co-author Mu-ming Poo, director of the Chinese Academy of Sciences’ Institute of Neuroscience in Shanghai, said that these monkeys could be used to study complicated genetic diseases where environmental factors also play a significant role, such as Alzheimer’s and Parkinson’s diseases. While there are ethical concerns on this technology and its easy application to human cloning, it is worth noting that almost all human creations (explosives, GMO food, the internet, etc.) are double-sided swords. It is up to the hand that wields this sword to decide whether to do good or bad. It is wise to be cautious with the development of new technologies, but it’s also important not to constrain our creativity. After all, it is our creative minds that drive us toward creating a better life for everyone.

Peer edited by Cherise Glodowski.

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Bonnethead Shark: The Newest Veggie Lovers of the Sea

Vegetarian sharks.

If you love a cheesy sci-fi movie as much as I do, the word shark probably brings a few images to mind; swimmers rushing to shore, a huge, hungry, Great white, ready to devour anything in its sights. You may have even started humming the iconic Jaws theme. But you might be surprised to hear that off the big screen, not all sharks are out for blood. In fact, one shark prefers a leafy, green, salad.

We often think of sharks as strict meat eaters, but researchers at the University of California-Irvine are turning the meat hungry shark stereotype on its head with their (mostly) vegetarian Bonnethead sharks. The Bonnethead shark is a small type of hammerhead shark often found in warm, shallow waters of the Northern hemisphere. Bonnetheads get their name from their distinct shovel-like head shape.

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The Bonnethead shark’s unique head shape distinguishes it from its hammerhead cousins.

 

Though distinct in appearance, the characteristic that makes the Bonnethead shark truly unique is its diet. Sharks are infamous meat-eaters. The Bonnethead, however, prefers its meat with a side of veggies. Studies on the diet of the Bonnethead began in 2007 when large amounts of seagrass were found in the stomach of a shark in the Gulf of Mexico. For many years, it was thought the seagrass was indigestible and eaten on accident while the sharks were hunting for shrimp, mollusks, and small fish in the seagrass ridden waters. Recent research now suggests Bonnethead sharks can digest the seagrass they eat and could use it as a source of nutrients.

As the first seagrass-eating shark be discovered, there are still many questions surrounding this veggie-loving shark. Does the Bonnethead eat seagrass on purpose? Or is it accidentally consumed while hunting for creatures on the ocean floor? Perhaps the most puzzling question is how  the Bonnetheads are able to digest seagrass? Because Bonnethead sharks have short intestines that are typical of a strict meat eater, scientists suspect bacteria living in the gut give the Bonnethead the ability to digest seagrass. More research is needed to discover which, if any, bacteria help the Bonnethead digest its dinner.

Although questions remain, one thing is certain; the Bonnethead shark is a unique and remarkable creature with much to teach their human neighbors about what constitutes a five-star meal under the sea.

Peer edited by Zhiyuan Liu.

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Understanding the 2017 Climate Science Special Report

Earlier this year, the U.S. government released the Climate Science Special Report.  This document describes the state of the Earth’s climate, specifically focusing on the U.S.  If you are someone who is interested in environmental science or policy, you may have thought about reading it.  But where to start? The report contains fifteen chapters and four additional appendices, so reading it may seem daunting.  We published this summary of the report to provide a brief introduction to climate change, and to provide a starting point for anyone who wants to learn more.  

https://www.nps.gov/articles/glaciersandclimatechange.htm

Retreating of Lyell Glacier (Yosemite National Park) in 1883 and 2015. Park scientists study glaciers to understand the effects of climate change in parks serviced by the National Parks Service. 1883 Photo: USGS Photo/Israel Russell 2015 Photo: NPS Photo/Keenan Takahashi

 

 

 

 

 

 

 

 

 

 

 

 

What is Climate Change?      

“Climate change” is a phrase that has become ubiquitous throughout many aspects of American and global society, but what exactly is climate change?

Like weather, climate takes into account temperature, precipitation, humidity, and wind patterns.  However, while weather refers to the status of these factors on any given day, climate describes the average weather for a location over a long period of time.  We can consider a climate for a specific place (for example, the Caribbean Islands have a warm, humid climate), or we can consider all of Earth’s climate systems together, which is known as the global climate.

Depending on where you live, you may have seen how weather can change from day to day.  It may be sunny one day, but cool and rainy the next.  Climate change differs from changes in weather because it describes long-term changes in average weather. For example, a place with a changing climate may be traditionally warm and sunny, but over many years, become cooler and wetter.  While weather may fluctuate from day to day, climate change is due to gradual changes that occur over long periods of time.  Climate is viewed through an historical lense, comparing changes over many years. Though we may not notice the climate changing on a daily basis, it can have drastic effects on our everyday lives.  It can impact food production, world health, and prevalence of natural disasters.

https://commons.wikimedia.org/wiki/File:Effects_of_global_warming,_plotted_against_changes_in_global_mean_temperature.png

Summary of the potential physical, ecological, social and large-scale impacts of climate change. The plot shows the impacts of climate change versus changes in global mean temperature (above the 1980-1999 level). The arrows show that impacts tend to become more pronounced for higher magnitudes of warming. Dashed arrows indicate less certainty in the projected impact and solid arrows indicate  a high level of certainty.

What Causes Climate Change? 

The major factor determining the Earth’s climate is radiative balance.  Radiation is energy transmitted into and out of the Earth’s atmosphere, surface, and oceans.  Incoming radiation most often comes from light and heat energy from the Sun.  Earth can lose energy in several ways.  It can reflect a portion of the Sun’s radiation back into space.  It can also absorb the Sun’s energy, causing the planet to heat up and reflect low-energy infrared radiation back into the atmosphere.  The amount of incoming and outgoing radiation determines the characteristics of climate, such as temperature, humidity, wind, and precipitation.  When the balance of incoming and outgoing radiation changes, the climate also changes.

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Scientists agree that it’s extremely likely that human activity (via greenhouse gas emissions) is the dominant cause of the increase in global temperature since the mid-20th century.

There are some natural factors that can influence climate.  The main ones are volcanic eruptions and the El Niño Effect.  Volcanic eruptions emit clouds of particles that block the Sun’s radiation from reaching the Earth, changing the planet’s radiative balance and causing the planet to cool. The El Niño Effect is a natural increase in ocean temperature in the Pacific Ocean that leads to other meteorological effects.  The increase in ocean temperature off the coast of South America leads to higher rates of evaporation, which can cause wind patterns to shift, influencing weather patterns worldwide. Together, these factors influence climate, so when they differ from the norm, they can contribute to climate change.

It is true that climate change can occur naturally and it is expected to happen slowly over long periods of time.  In some cases, the climate can change for a few months or years (such as in the case of a volcanic eruption), but the effects of these events are not long-lasting.  However, since the Industrial Era, the factor contributing most to climate change has been an anthropogenic driver, meaning one that is being caused by human activity. The primary cause of climate change since the Industrial Era has been the presence of greenhouse gases in the atmosphere.  The main greenhouse gases are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).  These gases are problematic because they remain in the Earth’s atmosphere for a long time after they are released.  They trap much of Earth’s outgoing radiation, leading to an imbalance of incoming and outgoing radiation energy.  Because the Earth’s atmosphere is holding on to all that energy while still receiving irradiation from the Sun, the planet heats up.  This is called the greenhouse effect, because it is similar to what happens in a greenhouse—the Sun’s energy can get in, but the heat cannot get out.  The greenhouse effect has intensified due to the greenhouse gases that are released during our modern industrial processes.  This has caused the Earth’s climate to begin to change.

 

Who contributed to the Climate Science Special Report?

The report was written by members of the American scientific community, including (but not limited to) the National Science Foundation, the National Aeronautics and Space Administration (NASA), the US Army Corps of Engineers, and multiple universities and national labs.  They analyzed data from articles in peer reviewed scientific journals—that is, other scientists read these articles before they were even published to check for questionable experiments, data, or conclusions—as well as government reports and statistics and other scientific assessments.  The authors provided links to each source in citation sections at the end of each chapter. They combined everything they learned into this one comprehensive document, the Climate Science Special Report.

What can we learn from this report?      

First of all, the report reveals that the Earth is getting warmer.  The average global surface temperature has increased about 1.8°F (1.0°C) since 1901.  This may seem like a small change, but this increase in temperature is enough to affect the global climate.  Sea levels have risen about eight inches since 1900, which has led to increased flooding in coastal cities.  Weather patterns have changed, with increased rainfall and heatwaves.  While the increased rainfall has been observed primarily in the Northeastern U.S., the western part of the U.S. has experienced an increase in forest fires, such as those that have devastated California this year.  Such changes in weather patterns can be dangerous for those who live in those areas.  They can even damage infrastructure and affect agriculture, which impacts public health and food production.  These changes mainly result from greenhouse gases, namely CO2, that humans have emitted into the atmosphere.

Where can I go to read the report myself?  

You can find a link to the main page of the report here.  There is also an Executive Summary, which was written for non-scientists.   While the rest of the report contains some technical language, it is generally accessible, and contains visuals to help readers understand the data.  If you are interested in gaining a better understanding of Earth’s climate and how it’s changing, we encourage you to take a look at the Climate Science Special Report to learn more.  

 

Peer edited by Amanda Tapia and Joanna Warren.

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Looking for a New Year’s Resolution? Shrink Your Plastic Footprint!

Plastics are nearly unavoidable. From the plastic bottle of water you grab walking into a meeting to the money in your wallet, plastics are ubiquitous. However, evidence is accumulating that heavy plastic use takes a hefty toll on the environment, especially the world’s oceans, which are the repository of nearly 4.8-12.7 million tons of plastic each year (about five bags of plastic for every foot of coastline in the world). Much of this marine plastic comes from litter that washes down storm drains into the oceans, but it can also be blown from landfills to end up in the ocean. Marine wildlife including fish, birds, seals, turtles and whales consume startling amounts of plastics, not only because these plastics look like dinner but because they often smell like it too. Dangers of plastics to marine animals include entanglement and intestinal perforation or blockage which can cause nutrient starvation—marine animals starving on a stomach stuffed with plastic. Researchers estimate that 90% of sea birds and half of all sea turtles have consumed plastics.

https://pixabay.com/en/rubbish-seaside-beach-waste-1576990/

Millions of tons of plastic waste winds up in the ocean each year.

More recently, the alarm has been raised about microplastics, small plastics and plastic fibers less than 5 mm in size. Microplastics can come from the degradation of larger plastics and from washing clothing containing synthetic fibers. Microplastics act like magnets for chemicals the U.S. Environmental Protection Agency (EPA) calls “Persistent Bioaccumulative and Toxic Substances” (PBTs). PBTs build up in the bodies of marine organisms and can harm us when we consume seafood. Though other potential dangers of microplastics to the environment are not clear yet, it has been shown that the decomposition of plastics can release toxic chemicals including bisphenol A (BPA),  a chemical which disrupts hormone balances and may be linked to human health concerns including diabetes, behavioral disorders like ADHD, and cancer. Researchers at the University of Missouri-Columbia have shown that some of the same adverse health effects occur in fish exposed to BPA, indicating a risk to marine food chains and ecosystems.  It is clear that we do not yet know the full impact of plastics in our oceans—but that the dumping of plastic waste into marine ecosystems is not without consequences.

Although some solutions to the plastic crisis have been floated (excuse the pun) including giant plastic-collecting booms which collect large plastic debris in the ocean and plastic-munching bacteria, these approaches are only beginning to be implemented and have limitations. This is where we come in — preventing more plastics from getting into the ocean is an important first step. Simply recycling our plastics may not be enough: one professor of economics cites plastics as one of the least valuable recyclable items due to the high energy and resource costs of processing them. As a result, it is imperative to focus on reducing, rather than recycling plastics.

Here are 100 ways to reduce your plastic use, ranging from reusable coffee cups to making your own deodorant to avoid the use of plastic packaging—an idea that doesn’t stink. Another way to track your plastic use is to accept the Plastic-Free Challenge—a social media challenge that lets you share your commitment to reducing your plastic footprint with all your followers. A good way to get started is to keep track of how much plastic you use and strive to reduce this amount every week. If you want to think bigger than your own plastic footprint, you can call your representatives about measures like plastic bag bans in your city and about funding research for equipping water treatment facilities to deal with microplastic-contaminated effluent. This year, I’ll be making it my New Year’s resolution to reduce my plastic consumption: a small change in habits that can add up. Let’s face it, I was never going to make it to the gym, anyway.

Peer edited by Erica Wood.

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Uncovering Ancient Mysteries with Cosmic Rays

https://en.wikipedia.org/wiki/Giza_pyramid_complex

The Giza pyramids. The center pyramid (tallest) is the pyramid for King Khufu.

You probably don’t usually think of particle physics and the Great Pyramid of Giza as having much in common. In some ways, the two seem diametrically opposed: the Giza Pyramid is the pinnacle of past achievement while particle physics relies on cutting-edge technology. The Great Pyramid of Giza is the only one of the seven wonders of the ancient world that is still standing. It is the tomb built over 4,500 years ago as a monument to Pharaoh Khufu. Little is known about how such a massive structure was built so long ago or what the internal structure looks like. Historians and archaeologists have been trying to uncover these mysteries for centuries. On the other hand, particle physics is often portrayed in movies and TV as a futuristic discipline in which scientists develop futuristic weapons. As a result, when an article was published in Nature on November 2 with the title “Discovery of a big void in Khufu’s Pyramid by observation of cosmic-ray muons,” there was a media frenzy

What are cosmic rays?

Though we sometimes think of science as a means to developing a more technological future, it is also importantly a means to understanding the secrets of the past. Much of the information we have about the origins of the universe and the evolution of galaxies has come from studying the fundamental building blocks of matter. For example, some particle physicists study the atomic nuclei falling toward Earth’s surface in cosmic rays. Studying this material provides insight into how galaxies are formed and how they evolved chemically.

When the protons and other nuclei in cosmic rays collide with nuclei in Earth’s atmosphere, pions are created. Pions then quickly decay and form muons. Muons have a negative charge like an electron but 207 times greater mass. The Earth’s atmosphere slows down all of the particles in the cosmic ray showers that are constantly raining down on the Earth. Because of their relatively large mass, muons are actually able to reach the surface of the Earth, unlike lighter particles. Detectors on or near the Earth’s surface can then detect these particles. In order to eliminate background noise from measurements, some particle detectors are placed deep underground in mines and caves. Learn more about what it is like to conduct scientific research in an underground laboratory in Underground Science at SNOLAB.

Using muon detection as an imaging technique

As early as 1955, physicists have taken advantage of the ability of muons to penetrate through rock by measuring the thickness of rock formations using muon flux (the amount of muons passing through an area of a detector). The concept of these measurements is similar to x-ray imaging. An x-ray is a high-energy form of electromagnetic radiation. Due to their high energy, x-rays are not readily absorbed by soft tissue such as skin and organs but are absorbed by denser structures like bone. If an x-ray source is aimed at a human arm and a film is placed on the other side of the arm, an image of the bones will be formed by the relatively low number of x-rays that reach the film behind the bones. Similarly, physicists working with cosmic rays realized that they could image large structures by taking advantage of the the fact that higher-density materials (such as stone) will absorb more muons than areas of lower density (such as air).

 Muon detection is a promising method for studying the pyramids because we can infer information about the internal structure without having to destroy it or to open up sealed sections. In 1970, researchers first attempted to use muon flux to search for cavities in the Giza pyramid. By placing detectors in the subterranean chamber (label 5 in the schematic diagram below), they were able to image a region of the pyramid occupying approximately 19% of the pyramid’s total volume. No new chambers were discovered in this region. Since then, detector technology has become more sensitive to smaller amounts of muon flux. In 2015, a team comprised of researchers from universities in Japan, France, and Egypt tried once again to use muon detection to search for cavities within the great stone structure. They tried three methods of muon detection, and this time they were successful.

 

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Cross-sectional schematic diagram of the Great Pyramid of Giza. 1) Original entrance 2) Forced entrance 3) Granite blocks which blocked off passage 4) Descending passage 5) Subterranean chamber 6) Ascending chamber 7) Queen’s chamber. 8) Horizontal passage 9) the Great Gallery, above which the void was detected. 10) King’s chamber & air shafts 11) Antechamber 12) Well shaft

Detection of the new void

First, they placed detectors inside the Queen’s chamber and in the corridor outside. These measurements were taken over the course of several months so that a relatively high number of muons would be recorded, making the measurements more accurate. The measured muon signals were compared with the signals they would expect based on what was previously known about the structure of the pyramid. From this method, they detected an unexpected excess of muons coming from the region above the Great Gallery. From this excess, the researchers inferred that there was an unexpected region of air inside the pyramid. The excess of muons is about the same as the excess of muons that pass through the Great Gallery, meaning the the newly detected void is approximately the same size as the Great Gallery. In order to verify their findings, the researchers used two additional muon-detection methods over the course of the next two years with detectors placed in different locations. Signals from all three methods pointed to the same conclusion: there exists a void in the stone structure above and parallel to the grand gallery.

 

While this information doesn’t directly tell us why or how the pyramid was built the way that it was, it adds to our knowledge about the structure and may help archaeologists infer something about the design. Although, since the publication of the article, there has been some controversy over whether or not this is actually new information, this research still clearly demonstrates that cosmic rays may be useful for understanding not only events that happened billions of years ago but also events that happened much closer to home. And importantly, this shows that science and the humanities have something to offer each other. As scientific advances continue to shape the political and cultural landscape of our future, we will also understand more and more about our past.

Peer edited by Mimi Huang and Jon Meyers.

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A Stimulating Treatment for Drug Addiction

Drug addiction is notoriously difficult to treat. Limited treatment options are available for those suffering from addiction, including behavioral therapy, rehabilitation programs, and medication. However, current drug addiction medications are only approved to treat opioid, tobacco, or alcohol abuse, leaving out many other drugs of abuse,such as cocaine or methamphetamine.

Yet even when patients successfully complete rehab or stick to a medication plan, there is still a risk of relapse. This can often be due to the emergence of drug cravings. For instance, a former alcoholic may see a sign for a bar they used to frequent. That sign can induce feelings of craving for alcohol, even long after the user quits or abstains from drinking. Strong cravings could lead to a relapse and a resumption of the cycle of addiction.  

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No pharmaceutical treatments are currently available for cocaine addiction.

However, a recent discovery may change the way we approach drug addiction treatment. Italian researchers, working alongside the National Institute on Drug Abuse (NIDA), were able to reduce drug cravings and usage in cocaine addicts for the first time using a technique called transcranial magnetic stimulation (TMS).

Long-term use of drugs change how brain cells communicate to each other. Think of a drug addict’s brain cells as speaking in gibberish, or unable to speak at all. Important messages aren’t being sent correctly, which contributes to the negative effects of addiction.

In a TMS procedure, researchers place a figure-8-shaped magnetic coil on the patient’s head. When turned on, the coil can send electrical signals into the brain. Importantly, brain cells communicate using electricity, and the “messages” between cells depend on the strength and frequency of these signals. Researchers found that the electrical signals from TMS help change the way brain cells “speak” to each other, getting rid of the gibberish and making cells communicate normally.

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TMS uses a magnetic coil to send electric signals into the brain.

In the case of drug addicts, the electrical signals from the magnetic coil are focused at a brain region called the dorsolateral prefrontal cortex (dlPFC). This is a part of the brain that handles decision making and cognitive ability, and is affected by drugs of abuse. For instance, drug addicts demonstrate lower dlPFC activity compared to non-addicted individuals during cognitive tasks.

Knowing how important this brain region is, researchers performed a study where they stimulated the dlPFC of drug addicts using TMS. They had cocaine addicts undergo either the TMS procedure or take medication (as a control group). They found that the cocaine users who experienced TMS had less cocaine cravings than their control counterparts. Further, the TMS group had more cocaine-free urine samples compared to the control group.

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The dorsolateral prefrontal cortex is affected by drug addiction.

Other studies support these results, focusing specifically on the prefrontal cortex, which appears to be a “sweet spot” for treating drug addiction. For instance, an earlier study found that daily TMS sessions, focused more broadly at the left prefrontal cortex, reduced cocaine craving. A later study honing in on the left dlPFC found similar reduction of craving in cocaine users.

Interestingly, the Italian TMS study was based on a rodent experiment with a very similar design. In this study, researchers allowed rats to develop a cocaine addiction and then stimulated a brain region analogous to the human dlPFC. Amazingly, the rats decreased cocaine seeking behaviors, much like their human counterparts in the TMS study. When this brain region was inhibited, or “turned off”, the rats increased their cocaine seeking.

Despite their promise, these TMS studies are just the beginning. Researchers are still a long way from developing a cure or reliable treatment for drug addiction. Like any new drug or treatment, it will be many years before TMS could be accepted as standard care for drug addicts. However, TMS has been successfully used to help patients in other ways. For instance, it has been used to help treat depression and is often used to help doctors identify damage from strokes, brain injuries, and neurodegenerative diseases. TMS holds a lot of promise and is on the cusp of being a successful drug addiction treatment. It’s only a matter of time before this stimulating idea becomes reality.

Peer edited by Robert Lee and Julia DiFiore.

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