The Potential for Caffeine-Free Coffee via Crispr/CAS9 or Crossbreeding (McGill OSS)

5 minute read

Our current methods for decaffeinating coffee are far from ideal. There are a few different methods, all with their own nuanced details, but they all shake out to using some kind of solvent to dissolve and remove caffeine from green coffee beans before roasting. This extra processing means costs to produce decaf are higher, profit margins lower, and production times longer. An even bigger problem is that even the best methods for decaffeination take some aromatic compounds away along with the stimulant molecule, affecting the taste and smell of the resulting coffee.

What if, instead of removing the caffeine from coffee beans, we could grow naturally caffeine-free coffee? Doing just that might be closer on the horizon than we expected.

To know how to stop a coffee plant from producing caffeine, it’s important first to recognize why it’s making it in the first place. Caffeine is a very bitter compound (one of the reasons coffee is a bitter drink), and just as we don’t tend to enjoy overly bitter things, neither do bugs. Coffee plants are believed to produce caffeine in their leaves mainly as a pesticide to defend against being eaten by pests like the coffee berry borer, Hypothenemus hampei.

Interestingly, ancestors of the modern coffee species were probably much lower in caffeine or entirely caffeine-free. The caffeine defence is believed to have developed in central and west Africa, where the coffee berry borer is native. This is where the highest caffeine species of coffee, like Coffea arabica and Coffea canephora, are found. These two species account for nearly 100% of the world’s coffee production.

A fascinating potential method for developing caffeine-free coffee plants involves the subject of the 2021 Nobel Prize in Chemistry: CRISPR/Cas9. Often referred to as “molecular scissors,” the CRISPR/Cas9 tool is inspired by bacterial defence mechanisms against viruses and allows the very precise cutting of an organism’s DNA. In this way, a gene can be targeted and deactivated. A review paper from 2022 took a look at the feasibility of using these molecular scissors to disrupt the biosynthesis of caffeine in coffee plants.

As caffeine is a relatively complex molecule, it isn’t built in just one step. Several enzymes are responsible for precise chemical changes to the proto-caffeine molecule en route to its final form. This is good news for scientists looking to disrupt the synthesis process, as they have multiple enzymes to aim for. The authors of the 2022 review identified an enzyme called XMT as a prime target. XMT is responsible for converting xanthosine into 7-methylxanthosine during step 1 out of 4 in the caffeine synthesis pathway. By targeting the very first step in the process, the subsequent enzymes have no molecules to work on. Debilitating XMT would lead to a build-up of xanthosine, but a different enzyme that can degrade it exists, so it shouldn’t be a problem.

Another potential target is called DXMT. This enzyme is responsible for the penultimate step in caffeine synthesis, converting theobromine into caffeine. Theobromine is quite similar to caffeine structurally and shares some properties with it, like being bitter and toxic to cats and dogs. Importantly, however, theobromine does not have the stimulating effect of caffeine. Targeting and disabling DXMT would lead to a build-up of theobromine in coffee beans, which may actually be a good thing! The bitterness of caffeine is part of the flavour of coffee, meaning that a C. arabica bean without caffeine may still taste different than a C. arabica bean with caffeine, even if they’re otherwise the same. The authors of the study postulate that the increased theobromine content of a DMXT-disabled bean could compensate for the missing bitterness from caffeine.

Genetically engineered caffeine-free coffee could represent a better way of getting our java without the jolt of stimulation, but it will undoubtedly face societal hurdles. While backlash to genetically modified organisms has calmed down recently, anti-GMO sentiments are still present in consumers and regulators. The regulations for getting such a product approved in Europe are particularly stringent and pose a significant barrier.

Even if CRISPR/Cas9 coffee isn’t commercially viable, using these molecular scissors to disable specific genes can help us better understand the complex biosynthesis pathways in coffee plants. So-called knock-out mice, named for having a gene’s function stopped (knocked out), have been pivotal in our understanding of physiology and biology. Want to know what a particular gene does? Knock out its function and see what happens. Much of our understanding of complex diseases like Parkinson’s, cancer or addiction is built upon the findings from knock-out mice.

Another approach to making delicious coffee without the kick may lie with modern species of coffee that naturally produce little or no caffeine. For example, Coffea charrieriana is a caffeine-free variety endemic to Cameroon. C. pseudozanguebariae is native to Tanzania and Kenya, C. salvatrix and C. eugenioides to eastern Africa. Unfortunately, these species of coffee all produce beans that would make a cup of joe that tastes decidedly different from what we’re used to. Still, one potential way to make coffee the same as our usual beans, just without caffeine, is by crossbreeding them with C. arabica plants.

There’s one big problem, though—Where the vast majority of coffee plants are diploid, meaning they have two sets of chromosomes (like humans), C. arabica is tetraploid and has four. Unfortunately, breeding between organisms with different ploidy is typically not successful. Recently, however, several low-caffeine varieties of C. arabica have been discovered in Ethiopia. Crossbreeding between the low- or high-caffeine types of C. arabica may result in a caffeine-free bean that is otherwise the familiar morning starter we know and love.

For the caffeine-sensitive among us, there are interesting new caffeine-free coffee possibilities on the horizon. Even if the methods I’ve outlined here don’t pan out, CRISPR/Cas9 will hopefully enable discoveries regarding caffeine and coffee plants. And we never know what the future may hold.

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When the Cows Come Home to Radioactive Ranches (McGill OSS)

5 minute read

A magnitude 9.1 earthquake occurred just off the northeast coast of Japan on March 11th, 2011, at 14:46 local time. The Fukushima Daiichi Nuclear Power Plant, like all nuclear power plants in Japan, features several safety mechanisms meant to mitigate damage to its reactors in such an event. It was built on top of solid bedrock to increase its stability, and all of its reactors featured systems that would automatically shut down—or SCRAM—the fission reactions in response to an earthquake. Luckily, only reactors 1, 2 and 3, out of six total, were in operation on that day and were successfully SCRAMed.

Even with fission stopped, however, the nuclear fuel rods continued to emit decay heat and required cooling to avoid a catastrophe. With connections to the main electrical grid cut off due to earthquake damage, the plant’s emergency backup diesel-run generators kicked in to power the cooling pumps.


Image Source

Almost exactly one hour after the earthquake, the resulting tsunami struck Fukushima Daiichi with waves 14 metres (46 feet) high. All but one of the diesel generators were disabled by the seawater, and by 19:30, the water level in reactor one had drained below the fuel rod. By the same time, two days later, reactors 1, 2 and 3 had all totally melted down.

In response, over the subsequent days, over 150 000 people were relocated from areas within 40 km of Fukushima Daiichi. Farmers were ordered to facilitate euthanasia for livestock from within the Fukushima exclusion zone, which was estimated to contain 3400 cows, 31 500 pigs, and 630 000 chickens.

Of those 3400 cows, the government euthanized 1500. CNN reports that roughly 1400 were released by farmers to free roam and potentially survive on their own. They are all thought to have starved to death. Three hundred of the remaining animals are unaccounted for, but some farmers who defiantly refused to cull their animals, nor chose to set them free, can account for 200 of the bovines.

Instead, these ranchers—made up almost entirely of cattle breeders—committed to travelling for hours every day into the potentially dangerous Exclusion Zone to continue to feed and care for what some of them refer to as the “cows of hope”.

Where dairy and meat livestock farmers tend to operate larger scale, higher throughput operations, cattle breeders often have small herds and are more attached to individual animals (some even have names). As one farmer told Miki Toda, “The cows are my family. How do I dare kill them?” These animals were spared simply because it was the right thing to do.

These cows and bulls will likely never be used for meat or have their milk collected for consumption. But that doesn’t mean they’re purposeless. Researchers from several universities, including Iwate University, University of Tokyo, Osaka International University, Tokai University, University of Georgia, Rikkyo University and Kitasato University, see the saved herds as an auspicious opportunity for knowledge acquisition.

The scientific research on how radiation affects large mammals is exceedingly sparse. According to Kenji Okada, an associate professor of veterinary medicine from Iwate University, “large mammals are different to bugs and small birds, the genes affected by radiation exposure can repair more easily that it’s hard to see the effects of radiation … We really need to know what levels of radiation have a dangerous effect on large mammals and what levels don’t.”

By studying the cattle exposed to radioactive fallout after the Fukushima Daiichi nuclear disaster, we stand not only to gain retrospective insights into the true effects of radiation on large bovine mammals but to be better prepared if such an event happens again.

The euthanasia of tens of thousands of farm animals represents a massive animal welfare challenge and has a drastic impact on the livelihoods of many. Not only farmers but workers from regulatory agencies, veterinary practices, slaughterhouses, processing plants, feed supply factories, exporters, and anyone else involved in any step of the agricultural process. Nonetheless, it is, of course, warranted if necessary for the safety of consumers of animal products. But was it necessary?

Research on the Fukushima Exclusion Zone herds has been ongoing for nearly a decade now, and while it will take more time to fully see the effects of chronic low-dose radiation exposure, scientists have published preliminary findings and are starting to see trends.

So far, the bovines have not shown any increased rates of cancer. The only abnormal health indicators are white spots that some have developed on their hides. A study of Japanese Black cattle residing on a farm 12 km to the west-northwest of the Fukushima Daiichi nuclear power plant in one of the areas the Japanese government has deemed the “difficult-to-return zone” found no significant increases in DNA damage in the cows. A different study found that horses and cattle fed with radiocesium-contaminated feed showed high radiocesium levels in their meat and milk. However, they found that after just eight weeks of “clean feeding” (feeding with non-contaminated food), “no detectable level of radiocesium was noted in the products (meat or milk) of herbivores that received radiocesium-contaminated feed, followed by non-contaminated feed.”

Much like Chornobyl (the Ukrainian spelling) has become a sanctuary for wild animals despite the residual radioactivity, signs are pointing to a natural “rewilding” of the Fukushima Exclusion Zone. With humans, cars and domestic animals gone, wildlife is able to move into empty urban and suburban environments and thrive. A trail cam study of wild animals around the Exclusion Zone has uncovered “no evidence of population-level impacts in mid- to large-sized mammals or [landfowl] birds.” Wild boars are abundant in the Fukushima region and present another good representative mammal to research. A study of 307 wild boars found no elevation in genetic mutation rates and that a certain amount of boar meat could even be safely consumed by humans.

Although nuclear radiation is a frightening threat, in part due to its invisible nature, evidence seems to be pointing to minimal, if any, health effects for animals exposed to the amount released by the Fukushima Daiichi disaster.

According to a study from the University of Bristol, it’s likely that the situation would be the same for humans had they not been evacuated/relocated. Due to the relatively low-dose nature of the event, the stigma and sometimes severe mental distress experienced by those displaced, as well as losses of life associated directly with relocation and indirectly via increases in alcohol-use disorders and suicide rates, the authors conclude that “relocation was unjustified for the 160,000 people relocated after Fukushima.”

This article was written for the McGill Office of Science and Society. View the original here: https://www.mcgill.ca/oss/article/history-environment/when-cows-come-home-radioactive-ranches

Blood Tests for Menopause (The Midlife)

4 minute read

One of the most common questions that we hear is, “How will I know if I am in menopause?” As you likely already know, that is not a simple yes-or-no question.

Menopause is defined clinically as 12 months of amenorrhea or absence of menstruation. That seemingly straightforward definition, however, masks a complex condition affecting millions of people. With an average age of onset of 47 years old, perimenopause—the transition period from fertility to menopause—can only be diagnosed in retrospect by considering a set of wide-ranging, somewhat vague symptoms.

Given the ambiguity and interpretation required in menopause diagnosis, a simple test that could definitively state whether someone has reached menopause or not would be extremely helpful for clinicians and patients alike. Medical practitioners can use some hormone tests to gather information about your reproductive status, but none provide the definitive answer we’d like them to.

This article was written for The Midlife. View the entire original here: https://themidlife.com/blood-tests-for-menopause/

When It Comes to Avoiding Flies, Stripes Are In, Solids Are Out (McGill OSS)

2 minute read

Fairy tales about the origin of zebra stripes are abundant. Some blame sunlight filtered through tree leaves for tanning the zebras hide, others claim the dark lines are scorch marks, acquired after stumbling into fire during a fight with a baboon. Scientists’ ideas of the stripes’ origins are less fanciful, but no less varied. From thermoregulation to signalling to other zebras, a lot of theories have been floated. Fewer theories have been tested, and only recently did support arise for one hypothesis: avoiding fly bites.

Despite their name, horseflies do not limit themselves to horses. There are well over 2000 species of horsefly that target a wide variety of animals, including humans. However, horseflies earned their moniker due both to horses, donkeys and zebras’ extreme prevalence, and the risks these bugs pose equids. Amongst other diseases, horseflies are infection vectors for equine infectious anemia, a retrovirus from the same genus as human immunodeficiency virus (HIV).

Within the Equus family, all 7 extant members have long tails to help flick away pesky insects. But the 3 living species of zebras have an additional tool in their anti-fly arsenal in their fur patterns.

Japanese Black cows painted with white to mimic the zebra coat received 50% fewer deerfly bites compared to those painted with black stripes, or no stripes at all.

Black cow painted with white stripes

Photo sourcehttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0223447

Don’t go painting yourself or your animals to avoid deerfly bites just yet though. There is one important specific you need to know first: the critical width. Black and white stripes present a sort of optical illusion to deerflies. Scientists believe that stripes narrower than a critical width (approximately 5 cm) trigger what we call the Wagon-wheel effect. This illusion makes a wheel, propeller or other regularly rotating object appear as if it is spinning backwards. You can see an example of it here.

When faced with black and white stripes, horseflies approached their target faster and failed to decelerate in the final stages of their flights, before contacting zebra surfaces. It’s not just painted mammals that seem to work though. Researchers demonstrated that horseflies will avoid landing on horses wearing a striped blanket, or other surfaces with thin stripes or small (<10 cm in diameter) polka dots.

This article was written for the McGill Office of Science and Society. View the original here: https://www.mcgill.ca/oss/article/environment-did-you-know/when-it-comes-avoiding-flies-stripes-are-solids-are-out

An essay on farts and 7 other deleted scenes from Love Actually (whynow UK)

5 minute read

It has been nearly 20 years since Love Actually was released, and it has grown from being a quirky ensemble film to a much beloved holiday tradition for many. Its intertwining storylines showcasing love of all varieties invoke nostalgia and tug at our heartstrings. But do you know its eight deleted scenes? From Sam being a gymnastics star to the cut lesbian lovers, Ada McVean looks at what could have been part of this Christmas classic.

It’s Porn

In this cut scene, Mia (Heike Makatsch) visits her friend Mark’s (Andrew Lincoln) gallery as he opens the new art for his Christmas exhibit, only to find that it is “porn.” Mia confides in her friend that she is considering having an affair with her married boss. He advises her to respect sacred marriage vows.

This scene foreshadows Mark’s struggles being in love with a married Juliet (Keira Knightley) and the deliberateness with which Mia pursues Harry (Alan Rickman). It establishes a link between Mia and Mark, making later scenes clearer. With this scene, we establish that Mark owns a gallery or is friends with Mia. When Harry says he’ll dance with Mia “as long as [her] boyfriend doesn’t mind,” and the camera pans to Mark, it now makes more sense!

An Essay on Farts

Bernard, Harry and Karen’s son, is unhappy at being cast as an Angel in the nativity play since they’re “made up rubbish.” His mum pushes back, suggesting that angels might be real, but in disguise—“these days they probably don’t have wings.”

This interaction was cut along with a storyline that would have seen Rufus (Rowan Atkinson) as an angel! Knowing this, some of Rufus’ actions make a touch more sense—he takes forever wrapping, hoping Harry will walk away without the necklace, and blatantly distracts the airport agent to allow Sam (Thomas Sangster) through.

Next, we see Harry and Karen (Emma Thompson) discussing their son when Karen asks, “when did my bottom stop being my bottom and turn into Britain’s second-largest seaport?” Harry reprimands her, “don’t be rude. I’ve invested a lot of time and emotion into that bottom.” A simple exchange of banter that shows the love between Harry and Karen, that, of course, also makes his betrayal all that more painful.

Karen and Bernard then meet with the headmistress to discuss his Christmas wish of everyone’s farts being visible. Karen pulls him into the hallway ostensibly to reprimand him and instead laments that no one at the school can understand his “high-class comedy,” we get a lovely look at a non-romantic form of love between mother and son.

This article was written for whynow UK. View the rest at the original here: https://whynow.co.uk/read/deleted-scenes-love-actually

Is it true that no two snowflakes are identical? (McGill OSS)

4 minute read

Snow crystals—better known as snowflakes—are intricate, delicate, tiny miracles of beauty. Their very existence seems unlikely, yet incomprehensible numbers of them fall every year to iteratively construct wintery wonderlands.

Every snowflake is formed of around 100,000 water droplets in a process that takes roughly 30-45 minutes. Even with this level of complexity contributing to each and every snow crystal, it seems nearly impossible that every single flake is truly singularly matchless. Yet, the scientific explanation of snow formation can explain how every snowflake tells its life story, and every story is unique.
The first known reference to snowflakes’ unique shapes was by a Scandinavian bishop, Olaus Magnus, in 1555, but he was a touch mistaken in some of his proposed designs.

Photo source: http://www.snowcrystals.com/history/history.html

Snowflakes’ six-fold symmetry was first identified in 1591 by English astronomer Thomas Harriot. Still, a scientific reasoning for this symmetry wasn’t proposed until 1611 when Johannes Kepler, a German astronomer, wrote The Six-Cornered Snowflake. Indeed, almost all snowflakes exhibit a six-fold symmetry—for reasons explained here—however, they rarely can be found with 3- or 12-fold symmetry.

The notion that no two snowflakes are alike was put forth by Wilson Bentley, a meteorologist from Vermont who took the first detailed photos of snowflakes between 1885 and 1931. He went on to photograph over 5000 snow crystals and, in the words of modern snowflake expert Kenneth Libbrecht, “did it so well that hardly anybody bothered to photograph snowflakes for almost 100 years.” Bentley’s assertion of snowflakes’ unique natures might be 100 years old, but it has held up to scientific scrutiny. Understanding how snow forms can help us understand precisely how nature continues to create novel snowflake patterns.

Snow crystals begin forming when warm moist air collides with another mass of air at a weather front. The warm air rises, cooling as it does, and water droplets condense out of it, just like when your shower deposits steam onto your bathroom mirror. Unlike in your bathroom, however, these water droplets don’t have a large surface to attach to and instead form tiny droplets around microscopic particles in the air like dust or even bacteria. Big aggregates of these drops are what form clouds.

If the air continues to cool, the water enters what’s called a supercooled state. This means that they are below 0˚C, the freezing point of pure water, but still a liquid. Ice crystals will start to grow within the drop only once given a nucleation point, a position from which ice crystals can begin to grow. If you’ve ever seen the frozen beer trick, it relies on the same mechanics.

Once a droplet is frozen, water vapour in the surrounding air will condense onto it, forming snow crystals, aka snowflakes. Not every droplet freezes but those that don’t will evaporate, providing more water vapour to condense onto the frozen ones. Once roughly 100,000 droplets have condensed onto the crystal, it’s heavy enough that it falls to earth.

The crystal patterns formed when the water vapour condenses onto a growing flake are highly dependent on temperature, and how saturated the air around it is. Below you can see a Nakaya diagram. Created in the 1930s and named for its creator, Japanese physicist Ukichiro Nakaya, it shows the typical shapes of snow crystals formed under different supersaturation and temperature conditions.

Photo source: http://www.snowcrystals.com/morphology/morphology.html

Above roughly -2˚C, thin plate-like crystals tend to form. Between -2˚C and -10˚C, the formations are slender columns. Colder still, -10˚C and -22˚C herald the production of the wider thin plates we’re most used to, and below -22˚C comes a rarely seen mix of small plates and columns. Snow crystals grow rapidly and form complex, highly branched designs when humidity is high and the air is supersaturated with water vapour. When humidity is low, the flakes grow more slowly, and the designs are simpler.

As a growing snowflake moves through the air, it encounters countless different microenvironments with slightly different humidity and temperature, each affecting its growth pattern. In this way, the shape of a snowflake tells its life story—the second-by-second conditions it encounters determine its final form. That’s where the unique nature of each snowflake comes from.

Kenneth Libbrecht is a snowflake scholar—a professor of physics at California Institute of Technology who has dedicated years of his career to uncovering the mysteries of snow crystals. He was even a consultant on the movie FrozenHe grows snowflakes in his laboratory using specialized chambers under highly controlled environmental conditions. Growing multiple snow crystals very closely together under essentially identical conditions, Libbrecht can create ostensibly identical snowflakes. But even still, he considers them more like identical twins. Can you visually see a difference between them? No, not really. But if you were to zoom in, and in, and in, on some level, you would be able to find differences.

Libbrecht thinks that the question of whether there have ever been identical snowflakes is just silly. “Anything that has any complexity is different than everything else,” even if you have to go down to the molecular level to find it.

This article was written for the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/environment-you-asked/it-true-no-two-snowflakes-are-identical

The Little Ice Age That Made Christmas White Forever (McGill OSS)

3 minute read

Our collective vision of Christmas landscapes is so immersed in snow that the very phrase “It’s beginning to look a lot like Christmas” conjures up imagery that is nearly all frosted, sparkling and white. This even though a snow-covered Christmas is the exception rather than the rule for the majority of the world.

Despite what the song “White Christmas” would make you think, for more than half the continental U.S., there is less than a 50% chance of a white Christmas occurring. Snow on December 25th is rare in the U.K. and not even as common in the Great White North of Canada as you may expect! So why do we pine for a pearly white holiday time?

Maybe Bing Crosby crooning, “I’m dreaming of a White Christmas, just like the ones I used to know,” has given you the impression that climate change is to blame for the seeming lack of modern-day snowy holidays. Global warming certainly has played a role in decreasing the chances of frosty festivities and will continue to do so. But the real reason behind our widespread association of Christmas and snow is less to do with changing weather patterns and more to do with our media.

Charles Dickens’ classic tale “A Christmas Carol” was written and published in England during the Victorian era. Where nowadays, you see far more fake snow than real, during Dickens’ early life, winters in the U.K. were snow-filled times of “piercing, searching, biting cold.” The 16th to the 19th century was a climatic period known as the Little Ice Age. As a result, most of Europe saw colder, longer, and more snowy winters than previously known. Winters cold enough to allow the River Thames frost fairs to occur on a frozen-solid Thames—something that hasn’t happened since 1814.

While familiar to us in much of Canada, the lasting snowy landscapes and beauty created by ice and frost were novelties to many artists, and Father Winter served as a muse for many. The Little Ice Age period gave birth to the vast majority of European depictions of winter in paintings and inspired numerous enduring works of art.

Charles Dickens has been called the man who invented Christmas—a definite exaggeration. But we can thank him, Jacob Marley, and Ebenezer Scrooge for helping to cement a Christmas aesthetic that has persisted with impressive consistency. Christmas is a time of nostalgia for many of us, and it was no different for Dickens. His stories contain references to the snowy cold winters of his childhood, making it ironic, in a sense, that we should now feel a sort of nostalgia for Dickens’ childhood winters too.

Our views that Christmases should be snowy don’t exclusively come from the England of yore. New media and art through the years have iterated upon Dickens’ Christmas setting and only further enshrined our association of Christmastime as snow filled. The United States have contributed their fair share to the frost-filled Christmas media. From “A Visit from St. Nicholas”—better known as “’Twas the night before Christmas”—discussing newly fallen snow to stories like “How the Grinch Stole Christmas” by Theodor “Dr. Seuss” Geisel, to the lithographic prints of Currier and Ives and the Christmas scenes of Norman Rockwell. The classic Christmas movie “It’s a Wonderful Life” even won an award for developing a new version of fake snow to replace the painted cornflakes used previously!

While Bing Crosby sings less about the white Christmases he personally knew and more about the ones we as a society used to know, the man who wrote the lyrics for “White Christmas,” Irving Berlin, was likely talking about both. a Jewish immigrant to the U.S., Berlin was born in Tyumen in modern-day Russia. With average daily December temperatures of -12.9 ˚C, he very well may have been referencing both his childhood Christmases and the historic Victorian ones enshrined in our holiday ideals.

This article was written for the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/history-environment/little-ice-age-made-christmas-white-forever

Peckers Get Smaller Where It Gets Colder (McGill OSS)

1 minute read

Charles Darwin postulated that Toucan’s massive beaks might be for sexual selection purposes. Other scientists have theorized that it could be for shows of intimidation, for actual defence or for peeling fruit. Given the beak’s serrated edge, it was once thought that toucans used it to catch and eat fish. We now know that toucans are almost entirely fructivorous, although they do opportunistically eat insects, lizards, and even small birds.

Another thing we now know is that the main function of a toucan’s beak is actually thermoregulation! Just like elephants do with their ears and dogs with their tongues, Toucans rely on their big beaks as heat sinks to maintain their homeostasis and save them from overheating.

Bird beaks across the globe follow a trend called Allen’s Rule, which proposes that the appendages of endotherms (warm-blooded animals) are smaller, relative to body size, in colder climates in order to reduce heat loss. A study of 214 bird species from every continent found strongly significant differences in their beak sizes according to latitude and local environmental temperatures. From penguins to parrots, the species that live in colder places have smaller peckers.

This article was written for the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/did-you-know/peckers-get-smaller-where-it-gets-colder

What rhythm does throbbing pain follow? (McGill OSS)

1 minute read

There are many kinds of pain—Piercing, burning, aching, shocking—but the type I want to focus on today is throbbing. Throbbing pain is often associated with toothaches, headaches, migraines, and pain in the extremities but can occur nearly anywhere in the body. Its pulsing nature can be incredibly annoying to those affected, but it also raises an interesting question: when pain throbs, what rhythm is it following?

Contrary to what you might think, throbbing pain is not beating to your heartbeat or pulse. A 2012 study looked at the throbbing rate of 29 dental patients’ pain, as recorded by patients pushing a button every time they felt a painful throb, compared to their arterial pulse measured in their earlobes. The mean arterial pulse rate was 73 beats per minute (bpm), compared to a throbbing pain rate of just 44 bpm. Researchers further analyzed the simultaneous recordings and found that the two rhythms weren’t synchronous in any way.

If throbbing pain isn’t paced against our heartbeat or pulse, then what determines its rhythm? Simply put, we don’t know! The study’s authors theorize that the pacemaker of throbbing pain is contained somewhere within the central nervous system, but we currently do not have any more specific theories. For now, we just have to accept that throbbing pain marches to the beat of its own drum.

This article was written for. the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/did-you-know/what-rhythm-does-throbbing-pain-follow

Why do we wake up feeling cold? (McGill OSS)

1 minute read

A few different bodily processes in humans follow a stable, roughly 24-hour cycle. For example, the cortisol and melatonin levels in our blood. Physical parameters like your blood pressure and heart rate too.

Also under a circadian cycle is our core body temperature. We reach our minimum temperature about halfway through our sleep cycle. By the time we wake up, our bodies have warmed up slightly, but often not yet to our typical body temp.

So, we wake up feeling cold because we are cold. From a normal body temperature of 36.4-37.2 °C (97.5-98.9 °F), normal circadian fluctuations can take us up or down about 1 ˚C. It might not feel like a lot, but remember that most doctors consider fevers to start at 38 ˚C.

Interestingly, there seems to be some variation in when we reach our minimum temperature during the night. A 2001 study measured the temperatures of 172 young men and women and sorted them according to their self-declared status of “morning person,” “evening person,” or “neither.” They found that morning people hit their minimum temps after an average of 3.5 hours, compared to 5.02 hours for neither types and 6.01 hours for evening types. Since individuals tend to feel more alert and perform better on cognitive tasks at higher body temperatures, these differences in the circadian rhythm of body temperature may be one reason some of us struggle to wake up and feel alert immediately.

Image source: https://www.mdpi.com/2079-7737/10/1/65

This article was written for the McGill Office for Science and Society. View the original here: https://www.mcgill.ca/oss/article/medical-you-asked/why-do-we-wake-feeling-cold