Sea Turtles: One of the Oldest, and Most Endangered Species

Chances are we've almost all seen the large posts in the ground warning us not to walk over where sea turtles have laid their eggs when we are at the beach; or we've heard the phrase "Save the Turtles!"at one point or another. But do we ever really stop to think about what that means? Sea turtles are some of the most fascinating (and important) creatures in the ocean, and yet, over time, the population has started to decline at drastic rates. 

Green Sea Turtles

In total, there are seven different sea turtle species. Three of these species are listed as endangered, and two more are listed as threatened. The seven different species are called Green, Loggerhead, Flatback, Hawksbill, Leatherback, Kemps Ridley, and Olive Ridley. Fossils relating to sea turtles date back to over hundreds of millions of years ago, and sea turtles used to live in abundance throughout the ocean. However, over the past 100 years, sea turtle populations have significantly decreased, largely due to human influence. 

Sea turtles were commonly exploited for their meat, and other profits, which caused a drastic hit to the population. On top of this, pollution, and a decrease in available land for laying eggs has also been detrimental to the overall population. Historically, there were dozens of known sea turtle populations, and yet today, only seven remain. 

Baby Sea Turtle!

One of the largest concerns regarding sea turtles is the nesting and hatching process. Male sea turtles spend their entire lives in the water, the only time they are outside the ocean is when they hatch. However, female sea turtles appear on the shore multiple times every few years to lay eggs. Many female sea turtles return to their natal beach to lay their own eggs, a process which occurs from usually April to October in America. Although it's extremely interesting, untrained human intervention can actually be detrimental to the process. People are known to scare away female turtles before they even lay their eggs; or confuse newly hatched baby turtles with house lights, and flashlights, causing many of them never to reach the ocean. 

Preventing the extinction of sea turtles is extremely important for many reasons, including the fact that they are responsible for maintaining the well being of many ecosystems. Sea turtles are actually known as "the lawn mowers of the sea," a comical yet fitting name for the mysterious creatures. Certain sea turtles are some of the only species known to eat sea grass, which grows along the ocean floor. This promotes the health of the sea grass beds, which directly contributes to the maintenance of biodiversity in the ecosystem. Sea turtles also maintain the health of the vegetation growing on the beaches in which they lay their eggs. Turtle shells and turtle eggs provide different necessary nutrients for the plants growing in the sand, which is hard for these plants to acquire in other ways. Vegetation in dunes helps increase the strength of the dunes, without this vegetation, the dunes would likely begin to disappear. 

Leatherback Turtle

                                                            

Although they have been around for what seems like forever, there is still so much that scientists are trying to uncover about sea turtles. They remain largely a mystery, and much about their lives and habits are unknown to scientists. Scientists continue to try and learn more about the fascinating animal, and yet they find themselves racing time, and trying to reverse the severe damage that humans have created for the species. 

Adrenaline: How it Affects Athletic Performance and the Body

As an athlete adrenaline is a really big part of the early stages of all my races, the intense surge of adrenaline allows me to perform at my peak. It creates a lot of confidence in me, that I know that I will be able to function as my max capacity during a race. If I'm not nervous or feel my heart racing before a race I feel really lackluster and not ready to perform. Adrenaline also gives me the feeling of excitement and allows me to perform in an intense and aggressive way which aids me in securing medals with the rest of my boat. 

    Athletes tend to defy all odds and push their body's boundaries to the extreme for sport. A big part of that is the presence or absence of adrenaline. Adrenaline primes and prepares the human body for exercise and allows for a short to moderate period of time during exercise where the body isn't feeling any discomfort or pain. Adrenaline's true purpose is to aid during dangerous situations, by causes temporary changes in the body. Heart rate and breathing increases as part of the body's innate "flight or fight" response.

An adrenaline molecule 

Adrenaline is most commonly known as a hormonal response to a stressful and anxiety inducing situation, more specifically when athletes are about to compete. Adrenaline increases heart rate and blood pressure, expands the airways leading to and from the lungs, and redistributes and redirects blood to the muscles which alters the body's metabolism to maximize blood glucose levels. Sometimes athletes will attempt to improve their performance with drugs that act on the β-adrenergic system. Which regulate airway function, muscle tone, increases vascular permeability and muscle contraction, and plasma secretion. Plasma is apart of blood and more plasma inn the bloodstream results in a hyper-responsiveness from the body. Some athletes take supplements and or drugs in an effort to enhance their performance by simulating the effects of adrenaline.

Too much hyper-responsiveness from the body due to adrenaline can result in weight loss, palpitations, anxiety, and even panic attacks. Which leads many athletes to take up mechanisms to calm themselves down like meditating, yoga, and deep breathing as a way to control their heart rate, so they can feel calmer and more in control when they're nervous before a race or event.

    

Track & Field Sprint Event 2016 

The stress or nerves an athlete feels before a race or sport event sends a signal to the adrenal glands to produce either epinephrine or adrenaline. Which begins the priming for rigorous physical exertion, once adrenaline is in the bloodstream it binds to the receptors on the outside of the cells of the liver and begins the signal transduction pathway. This causes a conformational change and activates the receptors, The activated receptor triggers a cascade of events within the cell, beginning with the activation of a G protein. The G protein then binds to the activated receptor, releases GDP, and takes up a molecule of GTP. After taking up GTP, the G protein is released from the receptor and splits into two parts. One of the parts is activated and continues the signaling cascade. Soon, the hormone also leaves the receptor, and the receptor reverts to its inactive form. 

 

The RIKKIO Rowing Team in 2018

When athletes develop an adrenal insufficiency, it is most likely due to overtraining, exhaustion, and/or stress. Which causes chronic fatigue, inconsistent or less production of epinephrine or adrenaline which is crucial to the beginning stages of any race. When a person has an adrenal insufficiency the body takes longer to properly get ready for any sort of exercise, whether it's extreme or moderate. It makes it more difficult to perform well. An adrenal insufficiency also leads to an individual not being able to cope with stress; and being an athlete is very stressful. So when an athlete is dealing with an overwhelming amount of stress and no adrenaline is being produced that will most likely lead to poor performance.

The Body's Response to Stress Diagram  

Let's dive in a little deeper: In the adrenal cortex cortisol, cortisone, and aldosterone are regulated. These hormones are cornerstones of bodily function. If production rate isn't high enough, the kidneys are not able to regulate themselves. Which then causes blood pressure and volume to drop (which can result in a life-threatening situation). Cortisol is a multipurpose hormone, it carries out a lot of jobs. For instance it maintains blood pressure and cardiovascular function, slows the immune system's inflammatory response, and stabilizes the effects of insulin in breaking down glucose for energy. It is also involved in the regulation of the metabolism of proteins, carbohydrates, and fats, which give athletes nutrients and the energy to perform. This simulates the liver into raising the blood sugar in response to metabolic demands, physical activity, and stress. Cortisol remains in the blood for a long time after being expressed, and is the body's long term response to stress, in contrast with adrenaline which is a very immediate its response is short lived.

If the adrenal gland complex isn't functioning properly it poses a great threat to the body and one's athletic performance and ability. If the long and short term responses to stress are compromised then adrenaline isn't properly produced and utilized and makes optimal performance for any athlete very difficult and or near impossible.

Bleach Bio

I've been bleaching my hair for a while now, and while I love the way it looks now, learning how to bleach it properly and keep it healthy has left me with more than a few bad (maybe closer to horrible) hair days, or even weeks. I've been over that for a while now, but these are all things I wish I understood when I started bleaching and coloring my own hair!

All visible hair cells are already dead, produced by the hair follicle within the dermis at the root. Some cells under your skin are already dead, but the hair matrix is an area of mitotically active (so they're alive) basal cells. That's why saying "dead ends" or that bleach kills your hair isn't really correct. These dead cells are keratinocytes, and have undergone a special type of apoptosis called cornification. After enough keratin has built up in the cell, the cell's organelles are ejected. The core of the hair shaft is the medulla, which is surrounded by the cortex, containing cells that are the majority of the shaft and its pigments. The cortex is made up of long keratin filaments that are held together by disulphide and hydrogen bonds, structural lipids, and dead cells. The outside of the hair is encased by the cuticle, having the main function of protecting the cortex. When the cuticle is healthy it's shingles of dead cornified cells lie flat, protecting the cortex, but when chemical processes like bleach disrupt it and raise the cuticle, hair can become brittle and not be able to retain moisture.

Picture I drew of the cross section of the hair shaft

Coiled Structure of Keratin

Hair Shaft and Root

Bleach is an oxidizing agent and removes color from hair and fabrics by releasing oxygen from chromophores, parts of a molecule that reflect color, and pigments. The oxidation breaks up chromophores and pigments so that they reflect colors outside of the visible spectrum, or no color at all.

Hair Bleach (H2O2+CaCl2) can only break down hair’s pigments by lifting and moving past the cuticle. Moisture and water from a shower can slightly lift the cuticle, but products like bleach and hair relaxers with a pH higher than 5.5 lift the cuticle completely. With the cuticle raised bleach enters the cortex and is able to oxidize melanin, a group of pigments that gives color to human skin, hair, and eyes. This makes hair lighter! While this happens bleach is simultaneously destroying the bonds within keratin and breaking down natural fatty acids. This means that while your hair is getting lighter it is also getting weaker. Going too light too quickly often results in fried hair, or hair becoming so weak it breaks off. To help replenish fatty acids or give the appearance of healthier hair, instead of buying fancy treatments plain oils like shea or jojoba are great! This works pretty well for long hair with "dead" ends as well, but unfortunately there is no fix for split ends.

Sometimes after too much bleaching or chemical treatment hair becomes extremely stretchy, or even slightly sticky when wet. This is caused by keratin leaching from within the cortex, reducing the amount of keratin and weakening hair enough to stretch more than is healthy or normal. The different types and quantities of melanin present in different hair colors affect how they react to the same bleaching. Blonde and light brown hair get lighter and yellow much faster because they already have little melanin. Black hair turns more orange when bleached for the first time because it has eumelanin (brown pigment) and pheomelanin (red pigment) and pheomelanin is broken down after eumelanin.

I've had stretchy hair, hair that seems dry beyond repair, and extremely patchy orange and brown.  After all the different hair issues and colors i've been through here are some of my favorites!

Don't Talk To Me, I Haven't Had My Morning Coffee

The famous line used by so many adults in my life - and I am sure yours as well. Personally, I do not drink coffee after noticing how many people are so dependent on it and cannot live without their morning cup but over 1 billion people in the world drink coffee daily! There are so many myths about coffee and false information spreading around, so how does drinking coffee every morning really affect you?

The Morning Cup in Question

First off, what does coffee even do to you? Caffeine is a stimulant, which means that it causes an increase in your brain activity and nervous system. Considered a drug, caffeine acts by blocking binding of adenosine to the adenosine A1 receptor, which enhances release of the neurotransmitter acetylcholine. As we know, many people drink coffee in the morning because they need caffeine to wake them up. There are 95mg of caffeine in a single cup of coffee - which is not a horrible amount. Healthy adults should not surpass 400mg of caffeine a day, yet teens should stick to less than 100mg a day. Caffeine is well absorbed by your body and the short-term side effects (usually appear 5-30 minutes after consumption) of caffeine help you feel refreshed, boost your energy, as well as improve your physical and mental performance. 

Good news or bad news? Why am I even asking this question? The bad news is, drinking coffee will increase your serotonin and dopamine levels which is a good temporary fix however once you stop drinking it, you can go into withdrawal. This is why many people are reliant on caffeine and "addicted" to coffee. Since your brain was so used to the high levels of serotonin and dopamine, your brain will act like there is a deficiency once you stop drinking coffee. It can take almost two weeks of a caffeine-free diet for your brain to go back to its normal state! Drinking coffee can also increase blood pressure, and even mildly increase cholesterol levels. 

Dramatized Image Made of Coffee Beans

Well onto the good news! Luckily, most of these negative effects are temporary and NOT life-threatening (contrary to what the image above depicts). Even better news - there may even be some benefits to drinking a cup of coffee every morning! Moderate coffee intake has actually been linked to a lower likelihood of type 2 diabetes, heart disease, liver and endometrial cancers, Parkinson's disease, and even depression!

You Once You Realize Coffee Isn't as Bad as You Think

Now why are there so many negative rumors about coffee? Well, early research linked coffee to diseases ranging from heart attacks to asthma, however, many of the people in these studies also smoked cigarettes which have led people to believe that the negative effects from smoking came from coffee.

Overall, it looks like one cup of coffee a day won't kill you - contradictory to what my mom told me. 

Epstein-Barr Virus: Not just a Kissing Disease

I'm sure you or someone you know has had mono in their lifetime. This saliva passed virus that can knock you out for a few months doesn't really end after that. Epstein-Barr Virus (EBV) is the disease that causes mononucleosis. This is one of the most common viruses across the globe, but it can have some pretty nasty long term effects. This tiny little virus is known to weaken your immune system but can do two other crazy things to mess with your body.

Epstein-Barr Virus Cell

First lets talk about the structure of EBV. The EBV virus is a linear viral cell composed of DNA with about 85 genes. EBV once it has entered the body goes after your B cells and epithelial cells. Even though EBV only enters these cells, the way they enter and replicate are different. To enter a B cell, a viral protein binds to a cell receptor which triggers the fusion of viral envelopes with the membrane of the B cell. To enter epithelial cells, a different viral protein interacts with a cellular integrin. The B-cell entry is not impeded directly by a viral protein, unlike the entry of EBV to an epithelial cell.

Epstein-Barr along with other forms of herpes does not go away after initial exposure. Once the virus is fought off it remains in your body in a dormant state. When your immune system is "distracted" fighting off another disease it is put under significant stress. EBV can take this opportunity to come out of hiding and attack your B cells. This activates the EBV in you allowing you to become contagious. You can shred the disease at age seventy-six even if you had it at seven years old.

Epstein-Barr Cell Structure

In addition to this virus never going away, it can become the cause of other illnesses. When you are infected with EBV the immune cells produce a protein by the name of EBNA2. Using transcription factors, these proteins bind to the genome of the cell and the virus. These new transcription factors adapt the expression of new viral genes as they enter the body making you more susceptible to these new viruses when they enter your body. These transcription factors can put you at an increased risk for diseases such as lupus and several other autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis, inflammatory bowel disease, type 1 diabetes, juvenile idiopathic arthritis and celiac disease. When specifically talking about Lupus, they found that the protein EBNA2 could be used at the binding site to drive the activation of these disease. This is deemed problematic because of how common Epstein-Barr is to humans. 

In regards to MS, people believe that Epstein-Barr can be the underlying cause of the disease. They ran an active experiment to test when the donors in this experiment became infected with EBV.    They tested samples from 801 people who developed MS. They then compared these to samples from more than 1,500 matched controls. Out of the 801 MS cases only one did not show signs of EBV before the onset of MS occurred. While scientists cannot say this is the underlying cause of both MS and other diseases, they can determine that this is a contributor to other diseases. 

Vaccination

As of May 2022, they have announced they are starting the early clinical trials for a vaccine for Epstein-Barr. This study will include 40 young adults, each will receive three doses of the vaccination. This will last about four years with the intent being a reduction in severity and instances of EBV linkage with other autoimmune diseases.

Viruses tend to uproot our lives. I chose this topic because in the fall I had a very nasty cold. After several doctors appointments, and no solutions they figured it actually wasn't viral but rather bacterial. While sitting in the office, one of the things that I had symptoms for was mono. My doctor shared with me information about EBV dormancy and it really struck me. I found it so interesting that I could get EBV from someone who had the virus twenty years ago! After doing more research I think its crazy to see how detrimental this virus can be to those who get the worst of the worst effects and I am hopeful to see a successful vaccine in the future!

The Science of The Bacon, Egg, and Cheese Sandwich

A New York style bacon, egg, and cheese sandwich on a bagel (with salt, pepper, and ketchup, of course) 

    First, let’s understand what a bacon, egg, and cheese is. A bacon, egg, and cheese is a breakfast sandwich that contains- you guessed it- bacon, egg, and cheese. Bacon, egg, and cheeses take many forms, but often the ingredients are sandwiched in between two pieces of bread (usually a roll or bagel) and topped with salt, pepper, and tomato ketchup. The bacon, egg, and cheese has become a staple breakfast item, the best known to be sold from New York bodegas. You may be asking yourself, "what does a breakfast sandwich have to do with science?" Like many dishes, the seemingly simple ingredients the bacon, egg, and cheese is composed of come from not so simple origins. In this post, we will explore the science that goes into the creation of each of the bacon, egg, and cheese’s main ingredients.

Bacon

    Early forms of bacon can be traced back to China thousands of years ago in the form of salted pork belly. Pork curing methods later made their way to the Roman Empire and Europe where the term “bacoun” was used to refer to pork in general. In America, bacon refers to the belly meat of the pig, differing from the back-derived version common in Europe. Before refrigeration, curing and smoking food items was a common preservation method used to make food last longer. Over decades, bacon has become a quintessential food item for Americans. Bacon can be enjoyed on everything from burgers to donuts and very few complete American breakfasts lack the salty treat. One of the things that draws Americans to bacon is its variance in textures. Some enjoy it crispy - some enjoy it floppy - and some (including me) enjoy it somewhere in between. The variance in texture is possible due to the unique mixture of fat and connective tissue found in belly bacon.

Bacon comes from the belly section as shown above

Fat Content and Texture

    The pork (pig) belly is known for its characteristic high fat content and toughness. Uncooked, the belly of a pig has a very tough texture which serves as the only barrier between the animal's organs and the outside environment. Pork belly maintains its tough structure by being made of a high amount of connective tissue and collagen. The collagen fibers form parallel bundles that run along the meat, sheathing the muscle and making contractions more efficient. The other layer of protection pork belly has is the high amount of intermuscular fat and adipose tissue. Adipose tissue is a specialized connective tissue consisting of lipid-rich cells called adipocytes that cover the outer surface of muscles. The main function of adipose tissue is to store energy in the form of lipids (fat). Besides energy storage, fat tissue has several other significant functions which include thermal isolation, cushioning the organs and muscle, an endocrine role, and the production of numerous bioactive factors. Fat molecules are made up of hydroxyl groups on a glycerol backbone that reacts with carboxyl groups of fatty acids in a dehydration synthesis reaction. This yields a fat molecule with three fatty acid tails bound to the glycerol backbone via ester linkages, called triglycerides. The linkages binding the fatty acids to the glycerol backbone contain an oxygen atom next to a carbonyl, or C=O, group. Triglycerides can contain three identical fatty acid tails or three different fatty acid tails. The high amounts of fat and connective tissue serve the pig well while it is alive, but after it is harvested, these attributes make cooking the meat more difficult. The curing, smoking, and frying process the pork goes through turns this difficult cut of meat into something delicious.

Comparison between triglyceride (top) and monoglyceride (bottom). In the example shown above, the three fatty acids attached to the glycerol backbone are all of different lengths.

Curing and Smoking

    One of the most important steps in the bacon-making process is curing and smoking. When the pork belly is removed from the whole hog, the meat must undergo a series of steps in order to ensure its stability. The first step is curing. The point of curing is to draw excess moisture out of a food item in order to limit the possibility of mold and bacterial growth. This is done by creating a solute gradient between the inside and outside of whatever is being cured. 

    Curing can be done in two different ways depending on the desired texture. The first way that bacon can be cured is by placing pork belly in a dry mixture of salt and sugar. The meat is left in the mixture for anywhere from hours to a couple of days depending on the thickness. Moisture is drawn out of the meat, giving it a more firm texture. The second way is by submerging or spraying the meat with a liquid salt and sugar brine and allowing the meat to dry in a cool, dry environment. This method removes less moisture than the dry brining process resulting in a softer texture. This is often the method that is used in commercial factories. It is important to note that in addition to sodium chloride (NaCl), sodium nitrate (NaNO3), also known as pink curing salt, is used to preserve wet-cured cooked meats like ham and bacon. This is to prevent Clostridium botulinum, a bacterium that is present in soil and water, from growing on the meat. The spores of the bacteria can become airborne and land on food where, under the right conditions, they can reproduce. When it reproduces, it creates the toxins that cause botulism, a foodborne illness that is rare but extremely severe. Pink curing salt helps stop the bacteria, preventing reproduction and the growth of the toxin.

    In both the dry and wet brining process, spices and herbs are mixed in to impart certain flavors onto the pork; these can include pepper, garlic, onions, bay leaves, and clove. The principle behind curing is one that governs much of natural life - osmosis. Osmosis is a process by which molecules of a solvent (usually water) tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one until an equal concentration on each side of the membrane is reached. In this case, The salt and sugar on the surface of the meat create a situation where there is more solute present on the outside of the pork belly. The water from inside the cells of the meat flows along its concentration gradient out of the meat, resulting in a dried product. From there, the bacon is cold smoked (meaning the smoke is not hot enough to cook the meat) in order to impart a smoky flavor and further dry out the meat. Similar to the curing process, flavor can be imparted onto the meat by using various types of wood such as oak, maple, hickory, and apple. After the smoking and drying process is completed, the processed bacon is sliced, sealed, and shipped off to grocery stores across the country.

 Slabs of smoked bacon 

This is an example of a wet cure. the bacon is sprayed with a brining solution and hung on hooks to dry

Browning and Maillard reaction

    Once the bacon makes it to your house, it can be prepared in many different ways, but for the bacon, egg, and cheese sandwich, it is usually pan-fried. Pan-frying the bacon not only fully cooks the bacon, but also allows the desired texture to be reached through browning. The actual term for this is called the Maillard reaction. While the reaction itself is extremely complex, the basics are that many small, simultaneous chemical reactions occur when proteins and sugars in and on your food are transformed by heat; these reactions produce new flavors, aromas, textures, and colors. The Maillard reaction is responsible for the tastes present in caramel, steak, coffee, and foods cooked in butter. These preservation and cooking processes result in the creation of a beautiful thing - BACON!

Fully cooked bacon

Egg

The next part of the infamous bacon, egg, and cheese sandwich is…EGGS! As off-putting as it may be, laid eggs are the embryonic stages of oviparous animals. They are composed of multiple sections that, if fertilized and incubated, will grow into juvenile versions of their species. Because they serve as mini-homes for embryos they are stocked full of protein, vitamins, and minerals that are passed along to whatever may eat them. For most people, chicken eggs are the only type of egg they eat, but it should be known that various poultry and reptile eggs are eaten within various global cultures. The bacon, egg, and cheese sandwich are most commonly made with chicken eggs. Chicken eggs have a somewhat mild flavor when compared to other poultry which has made them a favorite across the world. While eggs are most synonymous with breakfast, they are prepared in many different ways, from soups, baked goods, stir-fries, and even raw. Though, before the egg can be fried, scrambled, or poached for one of those preparations, a lot must happen in the chicken for the egg to get to this step. But, before we can understand how an egg is made, we must understand the parts of one.

Parts of an egg diagram

Yolk. This is the yellow part near the center, where almost all the egg's nutrients and fat are found

Albumen. This is the clear part we call the egg white. It’s called this because it turns white when cooked. There are two layers of albumen: thick (near the yolk) and thin.

Chalaza. Located in the thick albumen, chalaza is simply albumen that is twisted tightly. It keeps the yolk in the middle of the egg and prevents it from sticking to the inside of the shell.

Shell membranes. The egg contents are surrounded by two thin membranes called the inner and outer shell membranes.

Shell. This is the outer covering of the egg holding everything together. The shell consists of 94% calcium carbonate.

Egg Formation

    The egg is formed in the reproductive tract of a female chicken. The reproductive tract is divided into two major parts: the ovary and the oviduct. The ovary is where the yolk is added. When the yolk reaches the right size, it is released during ovulation. Ovulation is caused by the release of hormones. The released yolk is then picked up by the infundibulum, a funnel-shaped segment adjacent to the ovary. It is up to 9 centimeters long in the laying hen and has the function of searching for and engulfing the yolk that has just been released from the follicle into the adjacent ovarian pocket or body cavity. It is here that fertilization must take place. The yolk then passes to the magnum and isthmus, where the albumen shell membranes are added. Finally, the egg makes its way to the shell gland, where the shell and any shell pigments are added, before being pushed out. The eggs that most people consume are not fertilized, meaning that it has not fused with sperm from a male chicken. This also means that the egg has no chance of growing into a chick or chicken. Similar to humans, female chickens release eggs regardless of whether they are fertilized, the only difference being that chickens release eggs on a daily cycle rather than monthly.  

    Now that we have formed an egg, the next step is to cook it. For the bacon, egg, and cheese sandwich, the egg is usually pan-fried until the whites and yolk are fully set.

Hard fried egg (white and yolk are set) 

Cheese

    Cheese is a dairy product made from the curdled milk of land mammals, almost always grazers. Cheese-making is referred to in ancient Greek mythology and evidence of cheese and cheese-making has been found on Egyptian tomb murals dating back over 4,000 years. It is theorized that cheese may have been discovered accidentally by the practice of storing milk in containers made from the stomachs of animals. Most cheese is made from the milk of dairy cows specifically bred for dairy production. Cheese is aged and curdled in a variety of methods to produce many types of cheese.

Cow lactation

    Like all mammals, cows only produce milk after giving birth. Dairy cows must give birth to one calf a year to continue producing milk. After pregnancy, the levels of the hormones estrogen and progesterone fall initiating the hormones oxytocin and prolactin to increase and initiate lactation. Although various hormones take effect in milk production, prolactin is the key chemical. To increase milk production and ensure lactation year around, dairy cows are often given additional hormones. The milk produced contains the vitamins, calories, proteins, and hormones necessary to support a growing calf. It is due to its nutrient density that milk has become a staple beverage worldwide.

Curdling 

    In order to turn milk into cheese, it must go through many enzymatic processes. The first step is pasteurization, or rapid heating of the milk to kill any bacteria present. After the milk has been cooled, enzymes called rennet are added to the milk to begin coagulation. Rennet is the general name given to enzymes that act on the proteins in milk. It is derived from the stomach of adolescent ruminants (baby hoofed herbivores like calf and lambs) while their diets are still limited to milk; in their stomachs these enzymes aid in digestion. The milk is allowed to set until it reaches a pudding-like consistency. The curdled milk is then cut into very small pieces and mixed, causing the milk to separate into cheese curds and whey. Curds are the solid protein-bound pieces of curdled milk that will later turn into cheese and whey is the liquid that separates out. After the milk is separated, the liquid whey is drained off and the cheese curds are kneaded to form more protein within the solids. Salt is added and the cheese curds are then formed into blocks. From here, the cheese can be taken down numerous different paths.

Workers are kneading and packing cheese curds into blocks 

Aging

    What separates cheese from cheese curds is aging. Depending on the flavor and texture of the desired cheese, the curds will be aged for months up to years. During this aging process, moisture leaves, lactic acid fermentation occurs, and certain molds are allowed to grow. Longer-aged cheeses often have a harder, more grainy texture, and don't melt very well. Examples of this are cheeses like parmesan, aged cheddar, and Pecorino Romano. These cheeses often gain characteristic flavors like nutty and coffee notes. Longer-aged cheeses also tend to have a distinctly funky smell from the fermentation process. As delicious as those long-aged cheeses are, most cheese eaten on sandwiches like the bacon, egg, and cheese are not aged for as long. These cheeses include American, swiss, provolone, and young cheddar. These cheeses tend to have more moisture, a milder flavor, and a lower melting point. These characteristics make them great for sandwiches!

Cheese is allowed to age in a temperature and humidity controlled room, often on wooden shelves like those pictured above.

Assembly

Now that we have all of our ingredients the assembly of the perfect breakfast sandwich can finally begin. Our crispy bacon, fried egg, and American cheese can be stacked on a roll or bagel, topped with ketchup, and devoured. In my opinion, knowing the science behind arguably the best breakfast sandwich just adds to the joy of my first bite!

A fully assembled bacon, egg, and cheese sandwich

Nature vs Nurture: What Can Twins Tell Us About This Ongoing Debate?

 

Have you ever wondered how much of your personality is inherited and how much is thanks to your environment? I sure have! The Nature vs Nurture debate has been an ongoing discussion since the year of 1869 when psychologist Sir Francis Galton, a cousin to Charles Darwin, coined the terms through numerous twin and family studies. To understand this continuously disputed concept, we first have to understand each term involved. Nature refers to our genetic composition and how this can affect everything from our hair color down to our ability to learn a new language. Nurture refers to the environmental variables such as culture, parenting, trauma, and childhood experiences and how each contributes to who we are as a person.

 

A major method to collect data for this debate are twin studies. Twin studies offer us an accurate way to judge how much of a disease, behavior, or tendency is due to our environment or whether it's our genetic makeup. Identical or monozygotic twins provide a way of determining the true environmental effect since both twins are genetically identical. If one twin has a trait that the other doesn't, researchers can conclude that that trait is due to environmental factors. The differences in monozygotic twins are due to something called epigenetic differences. Epigenetics is the study of how one's environment can affect whether a specific gene will be expressed. These traits/alterations are passed down to offspring through generations without ever changing the DNA sequence of an individual. 

 Variation in Traits due to Shared/Unshared Environments vs Genetics

Identical twins that are separated at birth give us a real insight into the influence of genetics when both grow up in different environments. A study from 1979 gives a great example of the impact of genetics on someone's habits. Jim Lewis and Jim Springer, twins separated at the age of 4 weeks old, were reunited when they were 39 years old to find that they were both nail biters, had usual tension-headaches, smoked the same type of cigarettes, drove the same car, and even vacationed on the same beach in Florida. Similarities like these show us how many surprising traits are actually encoded in your DNA and how your environment has less impact than you may think. Contributing to this idea, research conducted by the University of Minnesota on identical twins who grew up in different environments, shows that identical twins who were reared apart had the same chance of being psychologically and physiologically similar than those who grew up in the same environment. I.Q levels have been shown to also be mainly influenced by genetics and not environment. According to the same study done at the University of Minnesota, on average, only about 25% of your IQ level is by environmental influence while 75% is genetic. Although overruled by genetics, the 25% environmental part of your IQ conveys neuroplasticity. Neuroplasticity is the ability for a person's brain to change, modify and adapt through an individual's life. A study done in 2011 by University College London took a group of teenage boys and girls and measured their IQ levels as well as MRI images at the beginning of their teenage years (ages 12-15) and 4 years later (ages 16-20). The results of this study surprised many with increases and decreases of up to 20 points (equivalent to 20%) and visible changes in the grey matter regions of their brains. These results are clear evidence that IQ levels are not something completely determined by birth but can change throughout your teenage years pointing towards the fact that your environment plays a more influential role in intelligence/IQ levels then you may believe. This study also conveyed the message that there are ways we can improve our traits such as intelligence through changing/bettering our environment which may give hope to those who are not genetically fortunate. 

 
Although genetics clearly do play a huge role in someone's characteristics and personality, environment affects whether or not those genes are expressed. Imagine an on and off switch determined by where you live and grow up (your environment). Monozygotic twins have the same genes but different potentials to express them based on their environment. Perfect pitch, by example, is genetic but can only be expressed with early musical training. Susceptibility to mental illness is also something which is mainly affected by environment. In the documentary "Three Identical Strangers," which I highly recommend watching, three identical triplets are part of a study where they are separated at birth and reunited. While all three different home environments were in the same 100 mile radius, the main variable in the study was the socioeconomic environment as well as the presence of a father in the household. One boy grew up with a upperclass father who was a doctor and was often unavailable, one triplet received a working class father with whom he often clashed/fought with, and one grew up in a working class household with a loving, available father. This difference had a huge impact on the boys and their mental health: The triplet who clashed with his middle class father developed manic depression and eventually shot himself, the triplet with an unavailable father also became depressed later on in life, and the one with a loving father was able to cope with his depression unlike his identical siblings. This study shows that although genetics clearly have an impact on a variety of traits such as mental illness, the environment a child grows up in has a huge effect on how that gene may or may not be expressed.

    

These twin studies have driven researchers to come to the conclusion that the answer to the debate of "Nature vs Nurture" isn't "Nature" or "Nurture", instead, it's actually about the effect that the environment plays on the expression of specific genes within an individual. Although these studies provide valuable data about the effect of the environment on an individual's behavior and personality, I feel the need to include that although important, these twin studies have also been very unethical. Many of these twins and triplets didn't even know that they were separated or were being studied! Maybe the real question is: Were the results of these studies significant enough to separate babies at birth without consent? I did some research into this bioethical question and didn't find much information as to whether or not studies as such are still going on. Twin studies are still occurring, but, from what I have found, they're voluntary and by sign-up!

The COVID Vaccine's Secret Ingredient

Vaccines: the technology has been a source of controversy ever since it was created by Louis Pasteur in 1798, and perhaps never more so than in the last two years. The COVID vaccine has been followed by the media and people all over the world since COVID itself entered the world stage--from its original production, testing, and distribution, to the political divides and government skepticism that followed. However, despite the intimate knowledge many have gained about the vaccine process over the course of the last couple years, there is still an interesting fact about the vaccine that most people are unaware of.

Someone receiving a COVID vaccine

Enter Limulus polyphemus, better known as the horseshoe crab--one of the most interesting creatures to ever crawl upon the Earth. Many people, especially here on the East Coast, have seen horseshoe crabs at one point or another while at the beach. Whether they are live and scuttling underfoot in the waves, or in the form of remnants of a shell washing up on the beach, catching sight of them isn't all that uncommon. They are relatively unassuming creatures, most are a dull brown color with a large, dome-shaped shell and long, pointed tail. The tail is harmless and is used to help the crabs flip themselves over if they ever get tossed upside down by a wave, not to sting people like my dad had told me as a kid. So, pretty boring, right? Wrong. This small, slightly creepy, creature is one of the oldest organisms on earth, remaining almost entirely unchanged for the last 445 million years. That is absolutely insane. Totally bonkers. That predates dinosaurs, predates trees, predates like--basically everything that isn't an amoeba! Their design is simple, but has helped them to outlive almost every other species. Makes sense that their moniker would be the "living fossil."

A cute little Atlantic horseshoe crab

Despite being called crabs, Limulus polyphemus are actually more related to scorpions and spiders than other crabs. They are arthropods, with a hard exoskeleton but no spine, and ten jointed legs they use to navigate themselves around the ocean floor and crush food before moving it to their mouths. It's kind of hard to find a creature to accurately compare them to because they are the only living species left in their phylum. 

A scary little Atlantic horseshoe crab

Every year like clockwork, these incredible little creeps flock to the beach to breed and lay eggs before returning to the ocean. They almost always come during a full or new moon, and always to the same beach with migration patterns that have lasted for hundreds of thousands of years. During late May/early June, a male will find a female in the shallows and hitch a ride on her tail to the beach. When they arrive the female will then dig small holes and lay millions of small, light blue eggs, and then the male will go through and fertilize them all. Most of the eggs will be eaten by other animals around the beach, they're a main food source for many bird species, but after about two weeks the eggs will hatch. Thousands of baby horseshoe crabs (which look exactly like the adults except without tails) will return to the water.

A handful of horseshoe crab eggs. They kinda remind me of robin eggs but in miniature. 

For the rest of the year the beaches will be deserted by the crabs, but during the month of May thousands of them all come at once and often cover beaches to the point where sand is no longer visible. One of the most popular breeding grounds is right in our backyard--the Delaware Bay. Some tourists come to see the weird sight, but there are also others waiting anxiously by to see them as well. If I asked you to take a guess at who these onlookers might be, I bet the first thing out of your mouth wouldn't be pharmacists. But low and behold, they're there. In droves. 

A whole lotta horseshoe crabs

See, horseshoe crab blood is one of the only known sources for a chemical called limulus amebocyte lysate, or LAL. LAL reacts with the endotoxin lipopolysaccharide, or LPS, which is a membrane component in gram-negative bacteria. When the amebocytes in the horseshoe blood (which is a bright blue color due to its copper base) interact with the endotoxins, it causes the blood to clot. In the wild this helps horseshoe crabs a ton because any bacteria getting into a cut on the organism will be immediately jello-ed up and isolated, halting any dangerous bacteria from entering the bloodstream. Humans rely heavily on horseshoe crab blood to create LAL for our medicinal uses. The compound is the basis for the LAL test, which is crucial to the sterilization testing that all surgical instruments, artificial body part replacements, injectable drugs, and vaccines undergo. If the LAL test isn't preformed and bacterial endotoxins go undetected, they can create an infection which can become deadly extremely fast. Since horseshoe crab blood is the only known source of LAL, without them this entire process would cease to exist, and everyone undergoing a vaccine or operation would be put at serious risk of infection and sepsis. Hence the pharmacists in Delaware Bay.

The pharmacists (or ecologists/fishermen who work for pharmaceutical companies) will come to the beaches during breeding season and capture thousands of crabs a day, putting them in transport containers to be taken to nearby processing facilities. Every year they round up half a million organisms on the East Coast alone. The crabs are then washed and sterilized, and put on a conveyor belt to have their blood sucked from them. It honestly looks like something out of a horror movie. They are hung upside down as technicians put an IV into a vein near the crab's heart, and then sit for a few hours as around 30% of their blood drips into a little bottle below. After the ordeal, around 30% of the crabs die, and the rest are returned to the ocean, through nobody really knows for sure how the crabs fare when they are released back into the wild and if the loss of blood affects them negatively or not. Some conservationists say survival rates could be improved with better treatment of the crabs, but better treatment is more expensive and pharmaceutical companies often aren't willing to pay the price.

Horseshoe crabs having their blood drained. Super weird, feels like something out of a sci-fi or horror movie or something

When the blood is all bottled up and ready to go, scientists will send it to another nearby pharmaceutical site. Some chemicals will be added to turn the blood into FDA approved LAL, which will then be put on the market at roughly $60,000 a gallon. Horseshoe crab blood ain't cheap. Although there are groups focused on finding a synthetic alternative to horseshoe blood as a source for LAL, everything they have produced so far is yet to be approved by all of the necessary groups needed for it to be considered a safe alternative for the standard, horseshoe-derived, version of LAL.

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A cute little juvenile horseshoe crab

Though the cost in crab lives may seem high, most conservationists say that the pharmaceutical industry isn't the biggest threat that horseshoe crabs face. In fact, many groups in the crab-draining industry work to pass legislation that help to preserve the crabs and their natural habitats, the most recent being laws passed in Maryland and Delaware making the use of horseshoe crabs as fishing bait illegal. But horseshoe crabs do face a great amount of danger. Every year they lose more of their precious breeding space on beaches due to erosion and human development on beaches, and ocean acidification due to climate change is causing pH levels in the Atlantic Ocean to no longer remain in the crabs' sensitive range. A more recent threat has been the intense red algal blooms that have been cropping up off the east coast from eutrophication due to human fertilizer run off.

A harmful red algal bloom in Nagasaki, Japan

During 2020, a record number of horseshoe crabs were captured to be used for sterilization of the millions of COVID vaccines being sent out around the country. Every time someone sat for their dose of the vaccine, there was a horseshoe crab's bright blue blood to thank. There was also a rather scary discovery made by a conservationist group from Maryland in 2020 during the height of COVID. It indicated that the horseshoe crab population was in severe decline, more than we had originally realized, due to habitat loss, climate change, and harvesting by pharmaceutical companies. Preserving these creatures is one of the many, many reasons climate change should be considered a top issue by legislators--it affects everything. Medicine, tourism, agriculture, the economy--quite literally everything. Nothing is left untouched by climate change, including the living fossil. Horseshoe crabs could outlast T-rexes and megalodons, meteors and volcanos, but it might not be able to outlast us. It's a pretty sobering thought.