Cambridge Researchers use Mouse Embryonic Stem Cells to Grow Artificial Mouse “Embryos”

Let’s start at the very beginning. When a mammalian egg is successfully fertilized by a single sperm, the result is a single cell called a zygote. A zygote has the potential to grow into a full-bodied organism. It is mind-boggling that this single cell, containing the genetic material from both parents, can divide itself to make two cells, then four cells, then eight cells, and so on, until it becomes a tiny ball of 300-400 stem cells.

https://upload.wikimedia.org/wikipedia/commons/3/3c/Stem_cells_diagram.png

Early Development and Stem Cell Diagram, modified by author to include ESC and TSC labels.

At these early stages, these stem cells are totipotent, meaning that they have the potential to become either embryonic stem cells (ESCs), which will eventually become the fetus itself, or extraembryonic trophoblast cells (TSCs), which go on to help form the placenta. That ball of ESCs and TSCs develops into a blastocyst with a tight ball of ESCs on the inside, and a layer of TSCs on the outside (See Figure 1).

You might imagine the blastocyst as a pomegranate, with the seeds representing the ESCs and the outer skin representing the TSCs. The ESCs have the potential to transform, or differentiate, into any type of cell in the entire body, including heart cells, brain cells, skin cells, etc., which will ultimately become a complete organism. The outer layer TSCs have the ability to differentiate into another type of cell that will ultimately attach itself to the wall of the uterus of the mother to become the placenta, which will provide the embryo with proper nutrients for growth. 

Scientists in the field of developmental biology are absolutely bonkers over this early stage of embryogenesis, or the process of embryo formation and development. How do the cells know to become ESCs or TSCs? What tells the ESCs to then differentiate into heart cells, or brain cells, or skin cells? What signals provide a blueprint for the embryos to continue growing into fully-fledged organisms? The questions are endless.

The challenge with studying embryogenesis is that it is incredibly difficult to find ways to visualize and research the development of mammalian embryos, as they generally do all of their growing, dividing, and differentiating inside the uterus of the mother. In recent years, there have been multiple attempts to grow artificial embryos in a dish from a single cell in order to study the early stages of development. However, previous attempts at growing artificial embryos from stem cells face the challenge that embryonic cells are exquisitely sensitive and require the right environment to properly coordinate with each other to form a functional embryo.

Enter stage right, several teams of researchers at the University of Cambridge are successfully conducting groundbreaking research on how to grow artificial mouse embryos, often called embryoids, in a dish.

In a paper published in Development last month, David Turner and colleagues in the Martinez-Arias laboratory report a unique step-by-step protocol developed in their lab that uses 300 mouse ESCs to form tiny balls that mimic early development.

https://www.biorxiv.org/content/early/2016/05/13/051722

Mouse embryonic stem cell aggregates with polarized gene expression in a dish (4 days in culture). Image courtesy of authors.   doi.org/10.11.01/051722.

These tiny balls of mouse ESCs are collectively termed “Gastruloids” and are able to self-organize and establish a coordinate system that allows the cells to go from a ball-shape to an early-embryo shape with a head-to-tail axis. The formation of an axis is a crucial step in the earliest stages of embryo development, and it is exciting that this new model system may allow scientists to better study the genes that are turned on and off in these early stages.

In a paper published in Science this past April, Sarah Harrison and her team in the Zernicka-Goetz laboratory (also at Cambridge) report another technique in which mouse ESCs and TSCs are grown together in a 3D scaffold instead of simply in a liquid media. The 3D scaffold appears to give the cells a support system that mimics that environment in the uterus and allows the cells to assemble properly and form a blastocyst-like structure. Using this artificial mouse embryo, the researchers are attempting to simulate the growth of a blastocyst and use genetic markers to confirm that the artificial embryo is expressing the same genes as a real embryo at any given stage.

The researchers found that when the two types of stem cells, ESCs and TSCs, were put together in the scaffold, the cells appear to communicate with each other and go through choreographed movement and growth that mimics the developmental stages of a normal developing embryo. This is enormously exciting, as models like this artificial embryo and the Gastruloid have the potential to be used as simplified models to study the earliest stages of embryo development, including how ESCs self-organize, how the ESCs and TSCs communicate with each other to pattern embryonic tissues, and when different genetic markers of development are expressed.

It is important to note that this artificial embryo is missing a third tissue type, called the endoderm, that would eventually form the yolk sac, which is important for providing blood supply to the fetus. Therefore, the artificial embryo does not have the potential to develop into a fetus if it is allowed to continue growing in the dish. The fact that these artificial embryos cannot develop into fully-fledged organisms relieves some of the controversial ethical issues of growing organisms in a dish, and will allow researchers to study critical stages of development in an artificial system.   

These techniques and discoveries developed by these teams of researchers have the potential to be applied to studies of early human development. These models may prove especially useful in studying how the maternal environment around the embryo may contribute to fetal health, birth defects, or loss of pregnancy. In the future, artificial embryos, coupled with the not-so-futuristic gene editing techniques that are currently in development to fix disease genes, may prove key in the quest to ensure healthy offspring. 

Peer Edited by Nicole Smiddy and Megan Justice.

Follow us on social media and never miss an article:

 

Cinnamon, Bam!

https://commons.wikimedia.org/wiki/File:001-Cinnamon.jpg Photo Credit: https://www.kjokkenutstyr.net/

Many of us associate the holiday seasons with the smells of cinnamon.

Well the holiday season is upon us. Our calendars and days are now filled with shopping, travel, and social gatherings with friends, family, and loved ones. As the temperature outside turns cold, we turn to many of our favorite treats to fill our bellies and help keep us warm. Our mouths water as we think about all of the delectable items that line our kitchens and tables. I can picture it now… a warm fire keeping the room nice and toasty, glass of wine in hand, friends and relatives conversing and catching up and of course, avoiding awkward conversations with Uncle Gary. All while hovering around various piles of unknown cheeses, meats, and delicious stacks of sweets. And If you’re lucky, you may even find a warm, sticky stack of homemade cinnamon buns. As it turns out, these may be just the thing to reach for to help burn off some of that unwanted extra “padding” that comes with all of those holiday favorites.

What’s that you say? Cinnamon buns burn fat? Well before you go eating the whole tray, it’s not really the cinnamon buns themselves that may help burn fat, but the cinnamon for which they are named. It tastes great, you can use it in all sorts of dishes, and it accelerates fat loss. I’m a fan of all of those things. Now, you probably find yourself asking, where can I learn more about this awesome spice? Well, look no further my friend, I am about to lay enough cinnamon-spiced knowledge on you to guarantee that you can bore your friends and family to tears with your cinnamon information stream at your holiday gathering. You’ll be less popular than Uncle Gary.

Cinnamon contains a compound known as cinnamaldehyde. Cinnamaldehyde is a naturally occurring chemical found in the bark of cinnamon trees that gives cinnamon both its characteristic flavor and odor. A recent study shows that cinnamaldehyde can even help burn fat by increasing metabolism and your body’s ability to breakdown fat! I know, it’s pretty magical. Now before you go running around stabbing cinnamon trees with a spout, there’s a few things you should know. Primarily that you have to fly to Sri Lanka, which is expensive but totally worth it since it’s a beautiful tropical island in the Indian Ocean. And you can even stay at a place called Cinnamon Bey, which looks like this picture I found of it on the interweb. Pretty sweet, huh? (See what I did there!)

https://commons.wikimedia.org/wiki/File:Map_of_Asia.png

Sri Lanka is located off the southeast coast of India.

Anyway, the purest source of cinnamon-derived cinnamaldehyde is the Ceylon Cinnamon tree (say that several times fast while jamming a sticky bun in your face!). Also known as, the “True” Cinnamon tree, which is named after the historical moniker of its native country, Sri Lanka (formerly Ceylon). The country still produces and exports up to 90% of the world’s true cinnamon. The other 10% comes from Seychelle and Madagascar, which are equally far and equally awesome as travel destinations. However, there are six species of cinnamon sold commercially around the world. So If you prefer the regular stuff found cheaply at most grocery stores, then you will have to head to China or Southeast Asia for the most common variant, cassia, which is considered to be less, um, “Top-Shelf”.

The cassia variant is cultivated on a larger scale and is coarser than ceylon cinnamon. It also has a higher oil content and contains more cinnamaldehyde, which gives it a harsher, stronger, spicier flavor than Ceylon cinnamon. Huh? Wait, you thought more cinnamaldehyde might equal more fat loss? You are correct my friend, but before you book that ticket to Guangdong and attempt the cinnamon challenge for the thirtieth time, you should know that the Cassia variety also contains coumarin, which is not found in the Ceylon variety. Coumarin is a naturally occurring blood thinner that can cause damage to the liver in high doses. So, take your pick, though if you really want that good, pure cinnamaldehyde, the “True” kind, then you better hustle it to Sri Lanka.

However, getting there is only part of the story. Isolating cinnamaldehyde from the bark of the Cinnamon tree is a slightly tricky process that involves some rather unsavory chemicals, the potential of explosions, and a few fancy science machines (namely a mass spectrometer) for pulling the oil out of the bark, to leave you with that tasty, cinnamoney goodness. What? You thought you could just grab a tree and squeeze really hard? No, no, no. That might work for your lemongrasses, aloes and coconuts, but not cinnamon.

Actually, I’m guessing from your weird tree-squeezing thoughts that you take Cinnamon for granted. I mean…your cinnamon disrespect is understandable, since you can buy it pretty much everywhere and it’s almost as prolific as pumpkin spice, but this wasn’t always the case. In fact, until recently true cinnamon was extremely rare, since there were no planes or cars…or Amazon, well the internet really…and it only came from one relatively small island in the Indian Ocean. As such, until the 1500’s cinnamon was highly valued and was given to kings and as tribute to gods. Eventually, during the colonial period, the East India Company (the original Amazon) began distributing the spice to the rest of the world and cultivating it on a large scale.

So, cinnamon has been around forever, you say, since remote antiquity and what-not. Great. But what about this cinnamon burns fat thing? First off, settle down. We have arrived, so here’s the details. A recent study from Jun Wu at the University of Michigan Life Sciences Institute showed that cinnamaldehyde increases thermogenesis, which is the process the body uses to create heat. Thermogenesis can burn a lot of calories and accelerate metabolism, and that results in the breakdown of fat. In addition, cinnamaldehyde can decrease and stabilize fasting blood sugar. What’s even more interesting is that chronic treatment with cinnamaldehyde can reprogram your body’s metabolism, which may serve as protection from diet induced obesity.

https://upload.wikimedia.org/wikipedia/commons/e/eb/Sticky_Vegan_Cinnamon_Rolls.jpg

Cinnamon is used in a variety of holiday treats including cinnamon rolls and apple pies.

So, cinnamon can burn fat and protect you from gaining it back! Now that is a magical spice. Well, there you go. I’m pretty sure that should be just enough information to cause awkward emotional discomfort to those within ear shot at your holiday festivities. Your shining personality may keep you from being the next Uncle Gary, but at least your cinnamon tales will have him running for the eggnog, which contains cinnamon. Bam! Take that Uncle Gary. No one cares about the length of your ear hair!

And while you’re enjoying your holidays, eating those cinnamon packed delicacies, remember the reason for the season! Be good to each other and have some fun, safe, and cinnamon filled holidays! Cheers!

 

Peer edited by David Abraham.

Follow us on social media and never miss an article:

Get Alternative with Epigenetics

Our bodies are marvels of precise control, synchronization and design. Every one of our cells has the same genetic sequence, but we have many different types of cells – heart, muscle, lung, skin. Amazingly, our body has a mechanism to determine which cell is which even though they all share the same code. The field of epigenetics dives into this phenomenon. Epigenetics is a study of changes to DNA that does not change the actual sequence but modify it by repressing or activating certain parts of DNA. In short, epigenetics can reversibly turn genes on and off without changing the DNA sequence.

The genes in our body are like words that have to be spelled a certain way in order for them to work properly. All genes are made up of “base” molecules, which are assigned a specific letter (A, C, G, or T). These bases combine to form 3-letter “words,” or amino acids.  Amino acids serve as the “words” that form the “sentences” or proteins in our body that govern all the biological processes necessary for life. However, none of these biological phenomena could be produced if there are misspellings in the genetic code. Mutations are a misspelling of the original genetic code through deleting, duplicating, substituting or inverting parts of a gene. Mutations are permanent changes to the DNA code which can be passed on from generation to generation. This is the cause of many heritable diseases.

For a long time, genetic changes were thought to be permanent, but reversible epigenetic changes were uncovered around 1950 and have led to an explosion of knowledge in understanding the human body. Conrad Waddington was the first scientist to propose the concept of epigenetics. He studied embryonic development and saw how an embryo gave rise to all the different types of cells, even though every cell had the same genetic sequence. He visualized this model with “Waddington’s landscape,” which used the analogy of a marble rolling down a hill into different troughs to represent the developing cell becoming a muscle cell, heart cell or any other cell.

https://upload.wikimedia.org/wikipedia/commons/5/54/Paisagem_epigenetica.jpg

The marble example that Waddington used to describe an embryonic stem cell becoming other cells.

Alternative splicing is one epigenetic mechanism that allows for cells to be able to choose multiple fates. This can happen all over the body, such as in the brain, heart, and muscle. Our body has many genes, but we only use 2% of those genes to code for proteins, the other 98% are genes that help regulate the protein-coding genes. Alternative splicing is one way that we fully utilize the 2% of our genes that code for protein and accounts for our complexity. Splicing allows for the “word” of one gene to be broken up into many different ways to make many other genes. The word “lifetime” can be broken up into ‘life’ and ‘time,’ but can also be rearranged to make the words ‘fit,’ ‘lie,’ and ‘tile.’ The parts of protein-coding genes can be also be broken down and mixed and matched to produce different proteins. The sites for splicing are determined by the tightness of DNA, the accessibility to DNA, and other epigenetic factors that are still being actively researched.

Emma Hinkle

An example of how alternative splicing can produce different protein products.

Dr. Jimena Guidice at the University of North Carolina at Chapel Hill is actively investigating the epigenetics of alternative splicing in the heart to try to determine why certain heart diseases cause the heart to revert back to fetal alternative splicing as opposed to adult alternative splicing. A few weeks postnatal, the muscle cells needed to contract the heart are not yet mature and have a different alternative splicing pattern to facilitate growth into adult muscle cells. Eventually, the muscle cells are spliced with a different alternative splicing pattern which is a mark of adult muscle cells since these cells are large and can pump blood to the heart more efficiently.

If you’re interested in reading more about epigenetics and its history, I highly recommend Nessa Carey’s Epigenetics Revolution and Siddhartha Mukherjee’s The Gene.  

Peer edited by Deirdre Sackett.       

Follow us on social media and never miss an article:

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.

https://commons.wikimedia.org/wiki/File:Earth%27s_greenhouse_effect_(US_EPA,_2012).png

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.

Follow us on social media and never miss an article:

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.

Follow us on social media and never miss an article:

What’s Your I.D.?

Some of my favorite TV shows as a kid didn’t involve cartoons or slapstick comedy.  They were educational shows – science and math shows to be more precise.  I watched Mr. Wizard set off volcanoes on Nickelodeon.  Bill Nye the Science Guy showed me how to make my own magnets.  I sang along with the cast of Square One about palindromes and negative numbers.  I sat amazed as The Bloodhound Gang solved mystery after mystery on 3-2-1 Contact.  I couldn’t wait to see another episode.  To have another opportunity to learn a shortcut to multiplying by 9.  Another chance to work up the courage to ask my mom if I could add vinegar to baking soda and just to see what happens.  To have one more moment to be in my element.  From the moment I saw these shows, I knew I wanted to participate.  I didn’t want to just watch someone else do cool experiments.  I wanted to do them too.

I took pride in putting together my science fair project on osmosis (i.e., put a celery stalk in a container of blue water, wait a few days, and see the blue liquid move up the stalk) all by myself.  I treasured my Fisher Price microscope set.  I was in heaven when I got the chance to test out an experimental touch screen in the Department of Electrical Engineering and Computer Science (where my mom worked as an administrative assistant) during “Take Our Daughters and Sons To Work” Day.  Looking back, my identity as a scientist was shaped at an early age, mostly outside of the classroom.  I didn’t know exactly what I wanted to be or what question I wanted to solve.  I just knew that I liked science and math and I wanted to keep going.

https://www.flickr.com/photos/wocintechchat/25900945412

Women of Color in Tech

 

As I got older, science enrichment programs reinforced my interests, placing me in a cohort of like-minded students – mostly people of color.  In high school, I spent my summers on the campuses of Syracuse University and Union College, conducting experiments on mice and learning proper pipetting technique.  Importantly, I made friends with peers from my hometown of Syracuse, NY and across the state who had similar interests and similar backgrounds.  We could go from talking about hypotheses to talking about Biggie Smalls.  We could talk about our favorite episode of “Martin” and then help each other balance chemical equations.  It was the perfect environment for an impressionable African American teenager to strengthen her scientific identity.  Much as television shows sparked my interest in elementary school, summer programs helped me realize that my dream could very much become an attainable reality.

I now recognize that all of these activities built upon my identity as a scientist.  The ways one perceives one’s self in science is considered a science identity.  It can be as weak as a vague interest in science or as strong as actively pursuing a scientific career.  The combination of informal experiences from television and formal educational opportunities via summer programs were  important, because it’s hard to become something you can’t see.  A recent study showed that science identity is a major factor in selecting a scientific occupation for minority students.  While this may seem obvious, we must continue to ask ourselves why there is such a lack of diversity and inclusion in STEM.  Perhaps early science identity development is a clue to improving STEM diversity.

Today, I have a strong identity as a scientist, actively pursuing a scientific career as a biomechanist and osteoarthritis researcher.  A number of factors may encourage or discourage individuals from moving towards science as a career; however, the value of early exposure and positive reinforcement should not be underestimated.  I am keenly aware that I am one of very few women of color in this position, and wonder how many more women like me might have pursued science if they thought they could do it.

Peer edited by Karen Setty.

Follow us on social media and never miss an article:

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.

 

https://commons.wikimedia.org/wiki/File:Cheops-Pyramid.svg

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.

Follow us on social media and never miss an article:

Artificial Intelligence: Should We Trust It?

If you’ve been following the news lately, you’ve probably read about the boom in Artificial Intelligence (AI). Some of the advances have elicited responses ranging from amazement to fear. So why has so much attention been diverted to AI recently? Advances in this technology over the past decade have surprised even experts in the field, and it has been spurred in part by cheaper and faster computing power as well as greater availability of large datasets. AI isn’t some futuristic technology that threatens to change our lives in the distant future, it has already changed our lives in many ways since its inception 60 years ago. Contrary to what many fear, however, it has not yet reached the point of surpassing human capabilities.

Definition and Scope of AI

The portrayal of problematic AI is pervasive in the film industry and can often be misleading. For a technology so widely discussed in popular culture, there’s no consensus on what it actually is. Stanford University’s 100-year study of AI defines it as “activity devoted to making machines intelligent, and intelligence is that quality that enables an entity to function appropriately and with foresight in its environment.” This definition may explain why my calculator isn’t intelligent, but what about my iPhone? It seems the key is that AI achieves specific goals through methods parallel to human intelligence. Most progress in AI today is within specific subfields like machine learning and deep neural networks, which has enabled the next generation of speech-recognition on the Amazon Alexa or the facial-recognition on the new iPhone X. Future uses of AI include autonomous self-driving cars, diagnostic healthcare and several other applications that we don’t yet have the foresight to predict. According to experts, AI doesn’t have the capabilities that match human intelligence but it does have the ability to process massive amounts of data and learn from it in ways humans can’t. With increasingly available big data and cheap computing power, it won’t take long for us to train computers to make extremely accurate weather predictions, find new drug targets, or mine complex biological datasets in a fraction of the time that humans can. AI is being tested on games like Go, Jeopardy and Dota 2 as a low-risk way to improve its algorithm and to demonstrate the human-like abilities of this technology.

Benefits and Drawbacks

https://www.pexels.com/photo/coding-computer-data-depth-of-field-577585/

Artificial Intelligence is exceeding our expectations but are we ready for the changes it brings?

In 2015, Stephen Hawking, Elon Musk and several other scientists and intellectuals signed  an open letter on artificial intelligence, specifically calling for more research on the potential impacts of AI on society. While they discuss several potential benefits of AI, scientists are also wary of the pitfalls and the possibility of losing control of autonomous AI. They believe that the rapid development of AI could threaten to shift society in ways similar to the industrial revolution or the creation of the atomic bomb; inventions that forever changed the social and economic landscape of the world. Another concern is the displacement of humans by robots in many fields. What kinds of jobs will become obsolete? This process of new technology getting rid of certain jobs is nothing new, but it could happen at a higher frequency. Therefore, more research is required to understand how the integration of new AI would affect certain industries.

Should we trust it?

There is no turning back from the future of AI. However, we as a society can engage on how we want to live amidst this increasingly powerful technology. During the past few decades, with the rise of social media, smartphones and cybersecurity issues, technological advancements have already forced us to think about the intersection of humanity and technology. Many scientists and intellectuals warn that AI is more advanced than anything we’ve ever dealt with. Therefore, healthy skepticism is warranted, but not so much that it hinders progress and inspires fear. The US is currently at the forefront of AI research, with China and Russia close behind. The technology is undergoing rapid progress so tighter regulation may slow research down. The existing technological hurdles gives society time to determine what roles we want AI to play in our lives. Some believe that this technology is merely an extension of human values and that our intentions will determine what our future with AI looks like. While this might be slightly naive, I believe that with the proper regulation set in place, we can make a better world more integrated with advanced technology.

Organizations Involved in A.I. Research and Outreach

  • Future of Life: A volunteer-run organization aimed at mitigating the existential risks to humanity from advanced AI.
  • OpenAI: An organization founded by Elon Musk to discover a path towards safe AI
  • Intelligence & Autonomy: A research organization funded by the Ethics and Governance of Artificial Intelligence Fund to “provide nuanced understanding of emerging technologies and to inform the design, evaluation, and regulation of AI-driven systems.”
  • Machine Intelligence Research Institute (MIRI): Aims to make intelligent systems behave in a manner that aligns with human intentions.
  • Future of Humanity Institute (FHI): A multidisciplinary research institute that publishes on AI governance, safety and other issues like biotechnology to shed light on humanity’s long-term future.
  • Stanford’s One Hundred Year Study on Artificial Intelligence (AI100):  To anticipate the effects of AI through a century-long chain of standing committees, study panels and growing digital archive.
  • National Science and Technology Council (NSTC): An executive branch advisory council released two documents highlighting comprehensive research and development plans for AI during the Obama administration (briefs for the Strategic plan and Preparation here). However, since this office has not been staffed under the new administration, it is unclear what steps will be taken by the government.

Peer edited by Gowri Natarajan.

Follow us on social media and never miss an article:

 

Tardigrades! The Super-animal of the Animal Kingdom

https://commons.wikimedia.org/wiki/File:Mikrofoto.de-Baertierchen5.jpg

Tardigrade (aka waterbear or moss piglet)

Tardigrades, also known as waterbears or moss piglets, are microscopic invertebrates that “resemble a cross between a caterpillar and a naked mole rat,” according to science writer, Jason Bittel. First discovered almost 250 years ago, there are now over 1,000 known species of tardigrade that can be found in almost every habitat throughout the world – from the depths of the ocean, to the tops of mountains, to your own backyard. As long as there is a little bit of moisture, you can find them. They are small and chubby, with most species being less than one millimeter in length. Their unique, usually transparent bodies have no specialized organs and four pairs of legs with claws at the end. Tardigrades can reproduce sexually or asexually via self fertilization. Like regular bears, Tardigrades eat a variety of foods, such as plant cells, animal cells and bacteria.

Despite being small, adorable microorganisms, tardigrades are fascinating creatures that have recently garnered the attention of scientists around their world due to their adaptability and resilience towards the most extreme environmental conditions. They have been observed to survive in a vacuum (an environment devoid air and matter) for up to eight days, for years to decades without water, temperatures ranging from under -200˚C to almost 100˚C, and heavy ionizing radiation. Tardigrades survive these conditions through a reversible mechanism known as desiccation (extreme drying), in which an organism loses most of the water in their body. In tardigrades, this can be as high as 97%. This is especially important in freezing temperatures, where water frozen into ice crystals can pierce and rupture the cells in the tardigrades’ body. During desiccation, the metabolic rate slows down to as low as 0.01% of normal function, allowing survival under the harshest of conditions for years.

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

Scanning Electron Microscopy image of a Tardigrade (Hypsibius dujardini)

In a 2016 Nature paper, scientists sought to answer the question of how a certain specie of tardigrade, Ramazzottius varieornatus, is so tolerant to extreme environmental conditions. They found an increase in several stress-related gene families such as superoxide dismutases (SODs). Most multicellular animals have less than ten SODs, however the study identified sixteen in this tardigrade specie. They also found an increased copy number of a gene known to play an important role in DNA double stranded breaks, MRE11. R. varieornatus had four copies of MRE11 while most other animals have only one.  Aside from having improved mechanisms of handling stress and DNA damage, scientists were able to identify waterbear-specific genes that seemed to explain tardigrades’ radiotolerance, or rather, resistance to radiation. The scientists were curious about whether this tardigrade-specific gene had any effect on DNA protection and radiotolerance in human cells. To their surprise, this gene, called DSUP for DNA damage suppressor, was able to decrease DNA damage in human cultured cells by 40% and decreased both double and single stranded DNA breaks.

At the University of North Carolina at Chapel Hill, Dr. Bob Goldstein studies animal development and cellular mapping during development in C. elegans and recently in tardigrades as well. He is also focusing on developing tardigrades into an new model system while studying their body development! His lab website has a section dedicated to tardigrades, with resources about them along with pictures and videos of tardigrades in motion.

The environmental resilience of tardigrades is incredible, making the tardigrade the super-animal of the animal kingdom (in my opinion). Who knows what other fascinating creatures we have yet to discover that may have characteristics as interesting and unbelievable as those of the tardigrade?

Peer edited by Nick Martinez.

Follow us on social media and never miss an article: