Introduced in 1979, the Papermate Erasermate offered something that, up until then, had been science fiction: an erasable pen. While correction fluids and tape were a well-established solution to inky mistakes, covering up errors was not the ideal way to correct them. Erasermate offered a simple alternative—just remove them.
Nearly three decades later, in 2007, Pilot debuted their own erasable pen by the name of FriXion. You’d be forgiven for missing this product launch. Erasable ink seemed like yesterday’s news at that point—literally a decades-old technology. But FriXion pens are a lot more revolutionary than they may seem.
The older Erasermate type of erasable pens are made with ink contained in rubber cement during production. The rubber cement keeps the ink particles from absorbinginto the paper but doesn’t prevent them from adsorbingonto it. What results is a mark on paper that is pretty similar to a graphite one made from a pencil. Since it hasn’t soaked into the paper but is just sitting on top of it, it can be rubbed off of the surface.
FriXion pens, meanwhile, rely on an entirely different phenomenon for their erasability. In fact, depending on how you think about it, they’re not really erasable at all.
The ink in FriXion pens is made of a three-component system. Contained in microcapsule particles with a diameter of 2-3 µm (For reference, that’s around 25 times smaller than the width of a human hair) are a leuco dye, a colour developer, and a colour temperature adjusting agent. The specific chemicals aren’t known—they’re proprietary trade secrets—but the general process works like this: At normal room temperatures the leuco dye and colour developer are in contact, and the ink is colourful. As the temperature rises the colour temperature adjusting agent starts to work, and the leuco dye and colour developer separate, rendering the ink colourless!
For FriXion pens, this colour change happens at roughly 60 ˚C. This can be achieved by heating the paper with a hairdryer or some other heat source or by rubbing it with a rubber eraser. Friction can make a surprising amount of heat surprisingly quickly—think about how you can start a fire by rubbing two sticks together.
A compound that changes colour with temperature is called thermochromic, and they have a few very important applications. Notably, receipts are printed on paper coated in such a compound. Cash registers don’t actually contain any ink. Instead, they are called thermal printers and work by selectively heating parts of their printer heads to produce the shape of a letter or number on the thermal receipt paper. Other technologies that use thermochromic dyes include mugs that reveal a design when heated and cold indicators on beer cans, like Coors Light.
The really neat part, in my opinion, is that this colour change reaction is reversible. Hence why one can debate whether FriXion pens truly are “erasable” or not. Lowered to about -10 ˚C (most freezers are around -18 ˚C) the “erased” ink will reappear as if by magic, but we know it’s actually just chemistry.
I am a big fan of erasable FriXion pens and recently experienced their reversible colour-changing phenomenon firsthand. Unfortunately, I left my notebook in the hot summer sun and returned to find it totally blank. Luckily, having researched this topic, I knew a couple of hours in the freezer were all I needed to recover my precious notes.
It’s minty, chalky, unpleasantly viscous, and useful for a wide range of stomach ailments, but why is Pepto-Bismol so vibrantly pink?
The active ingredient in Pepto is bismuth subsalicylate. Once in the stomach, bismuth subsalicylate breaks down into two products—bismuth and salicylic acid—the latter of which is rapidly absorbed into the bloodstream. Salicylic acid is the active ingredient in many anti-acne and wart products and is closely related to acetylsalicylic acid, better known as Aspirin. Bismuth is a metal with somewhat unique properties, including notably its low melting point of just 271.5 ˚C. As such, it finds use as a lead replacement in various contexts. One important one is in lead bullets, the use of which has been highly discouraged, or even outlawed in some places, due to its toxicity. If you have a free day, a bottle of bismuth subsalicylate and some laboratory equipment, you can even extract the bismuth from Pepto-Bismol—it’s iridescent and quite pretty!
Bismuth in the stomach is very poorly absorbed and combines with other compounds present to form various bismuth salts. These salts have antimicrobial activity and prevent bacteria from binding and growing on the mucosal cells of the stomach, as well as increasing fluid reabsorption and decreasing intestinal secretions and inflammation. In these ways, bismuth subsalicylate can help with a wide range of digestive issues, including nausea, diarrhea, stomach ulcers, heartburn, and even cholera.
Contrary to what you may be thinking, it is not bismuth subsalicylate that gives Pepto-Bismol its carnation colouring. That compound is beige. It turns out that Pepto is pink simply because Procter and Gamble dye it pink!
According to Pepto-Bismol, the doctor who developed their pink medicine in the early 20th century chose pink, but no one really knows why. They keep it pink because you don’t mess with success, and who can blame them? The practically neon hue of their product is instantly recognizable, even when their products are in chewable tablet or pill form. Even generic preparations of bismuth subsalicylate tend to stick to the pink colour palette.
In 1992, a Procter and Gamble spokesperson told the LA Times that the doctor chose pink to appeal to children, but as Pepto-Bismol is not recommended for kids under 12, that seems questionable. This recommendation is due to concerns that bismuth subsalicylate could contribute to a rare condition called Reyes syndrome in children. It’s for this exact reason that Aspirin (acetylsalicylic acid) is not approved for children under 12.
You shouldn’t worry about Pepto-Bismol turning you pink, but there is a slight chance it could turn your tongue, or your poop, dark black. This happens due to a reaction between the bismuth metal and sulfur in your mouth or digestive tract, producing bismuth sulfide. This might happen if you’ve recently eaten a lot of sulfur-rich foods—like cruciferous vegetables (broccoli, cabbage, kale etc.) or alliums (onions, garlic, leeks, etc.)—taken a high dose of a sulfur-containing medication (like sulfonamide antibiotics) or live somewhere with high sulfur concentrations in the water. Don’t panic; it’s only temporary and totally benign.
While the doctor who developed Pepto-Bismol and chose its hot pink shade probably didn’t know, the colour of a medication may have surprising impacts on how patients perceive its effects or rate its effectiveness. A couple of studies have found that patients are more likely to perceive warmly coloured medications (red/orange/pink/etc.) as stimulants or antidepressant drugs versus an association with tranquillizers or depressants for cool-coloured (blue/purple/green) meds.
When studied, the marketing of medications echoes this colour coding, implying a feedback loop between buying medications of a particular colour and associating that colour with that type of medication. Interestingly, studies have also shown that the colour of a drug can influence how bitter patients think it will taste and how strong they believe it is. Specifically for children, there’s a belief that red or pink medications make them look sweeter or more palatable to kids. So maybe the inventor of Pepto-Bismol was trying to invoke the idea of a strawberry milkshake!
Flying in an airplane is incredibly safe despite what our anxieties and fears might tell us. According to the International Civil Aviation Organization (ICAO), aviation has become the first ultra-safe transportation system in history. That means that for every ten million cycles (one cycle involves both a takeoff and landing), there is less than one catastrophic failure.
And yet, aviation accidents and incidents do still happen. I recently became deeply interested in aviation safety and got to wondering: Are there monthly or seasonal trends in when aviation accidents occur? Essentially, is there a statistically safer time to fly?
To answer that, we need to define the difference between an accident and an incident. It’s a subtle but important differentiation, because incidents happen all the time, while accidents are quite rare.
The ICAO defines an accident as “an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight until such time as all such persons have disembarked, in which a person is fatally or seriously injured” and/or “the aircraft sustains damage or structural failure … or the aircraft is missing or is completely inaccessible.” On the other hand, an incident is defined as “an occurrence, other than an accident, associated with the operation of an aircraft which affects or could affect the safety of operation.” In car terms, an accident would be something like a fender bender or crash, whereas an incident would be something like your check engine light coming on or your headlight burning out.
At the time of writing this article in late January 2023, globally, there have been seven accidents in 2023, only one involving fatalities (seventy-two people presumed dead after Yeti AT72 crashed in Pokhara, Nepal). Compare this with incidents, of which there are usually around three or four every single day. If that seems like a lot, remember that the strict reporting of nearly any deviation from perfect plane operation and function is a big part of what has made aviation “ultra-safe.” No piece of machinery as complex as planes will function perfectly 100 percent of the time. By strictly cataloging all incidents, we can continuously identify trends, issues, and ways to improve aviation safety even further.
If there are temporal trends in aviation safety, there are a few reasons those could exist. One potential would be due to weather. There are definite seasonal trends in weather considered hazardous. For example, winter in Canada and the northern United States sees more ice and snow. But the question is whether these weather trends translate into accident trends.
A 2018 study examined all reported worldwide weather-related aircraft accidents from 1967 until 2010. The absolute number of weather-related accidents has increased over that period but so has the annual number of flights, so that is expected. More interesting is the percentage of accidents that are weather-related, which has also increased from about 40 percent to about 50 percent.
This rise could be due to changing weather patterns. The potential effects of climate change on airline safety are rarely discussed, but as incidences of severe weather continue increasing, presumably, so will weather-related incidents and accidents.
The authors of that study, however, believe that this increase is primarily due to “the aviation safety improvements conducted between 1967 and 2010 hav[ing] had a smaller effect on weather-caused aircraft accidents compared with other accidents.” Essentially, while improvements in areas such as crew resource management, training, and maintenance have had positive effects on aviation safety, weather-related accidents have been less sensitive to these improvements.
To look for seasonal trends, the authors of the study divided the globe into four symmetric zones according to latitudes: Zone 1: Within 12 degrees of the equator; Zone 2: between 12 and 38 degrees (which is roughly the middle of the United States); Zone 3: between 38 and 64 degrees (which encompasses most of Canada) and Zone 4: the polar regions in the far north and south.
While each zone experiences different weather and climate trends in all but the polar regions, “weather-caused accidents can be considered as uniformly distributed in the various meteorological seasons.”
The U.S. Federal Aviation Administration (FAA) agreed with the study’s conclusions, telling me that they “have not identified any other broad, seasonal or monthly incident trends.” So basically, no, there are not seasonal trends in weather-related aviation accidents, even though there are definite seasonal trends in weather considered severe.
There are three other very interesting takeaways from this study. First, the two zones nearest the equator show a much larger proportion of weather-related accidents, but that isn’t necessarily due to experiencing more severe or dangerous weather. Instead, the authors state that this is due to these zones containing a greater proportion of developing countries that, while adherent to the ICAO safety standards, tend to operate with older planes and equipment.
Second, weather is much less relevant in accidents in developed nations. While the global percentage of weather-related accidents is approaching 50 percent, in the United States and the United Kingdom, it was only 23 percent (in 2012 and between 1977 and 1986, respectively).
Third, despite snow being a widespread occurrence in Zone 4, it has never been reported as the primary cause of any accident. On the other hand, snow accounts for 7 percent of accidents in Zone 2 despite being far less common. This highlights both the disparities in safety between “developed” and “developing” nations and the increased danger associated with unusual weather. It is far safer to land in a snowstorm at an airport that frequently experiences snowstorms because it has systems in place to handle it. Unfortunately, climate change will likely only increase the incidences of unusual weather.
What about non-weather-related temporal trends in airline safety?
Dr. Daniel Bubb, former airline pilot and currently an associate professor at the University of Nevada, Las Vegas, explained to me that we tend to see more accidents in the months of June to September simply because a lot more people are flying. A 2020 analysis of airplane crash data echoed this, as did the National Transportation Safety Board: “the more risk exposure tends to track closely with the actual number of accidents,” which makes a lot of sense.
Another potential trend in aviation safety could come from something analogous to the “July Effect,” as it’s called in North America, or “Black Wednesday,” as it’s known in the United Kingdom—the idea that the day/week/month when new student doctors and nurses start at hospitals is associated with a rise in mortality or morbidity.
Luckily, the aviation industries have safeguards in place to avoid an influx of new workers. For example, both the FAA and NAV CANADA told me they specifically stagger the starts of their new air traffic controllers. A representative of Republic Airways (a regional U.S. airline) told me the same for new pilots and other employees.
An important thing to remember is just how frequently pilots have their soundness evaluated. Dr. Bubb writes that pilots “undergo recurrent training each year” and “undergo physicals each year to maintain their licenses.” With so much oversight, intense training, and staggered starts, the potential for a “July Effect” in aviation is vanishingly small.
In fact, evidence is mounting against the existence of the July Effect in medicine. A 2022 comprehensive meta-analysis of 113 studies published between 1989 and 2019 demonstrates “no evidence of a July Effect on mortality, major morbidity, or readmission.” Studies comparing teaching versus nonteaching hospitals have found teaching hospitals safer year-round!
So, is there a time of the year you should avoid flying? No, not in terms of safety. And you likewise should not avoid heading to the hospital if you feel you need to. However, if you want to decrease how much you drive, that could help with both your safety and the environment.
Losing your hair might not be the most medically concerning symptom on its own, but its effects on mental health, social well-being, and personal identity can’t be understated. As Dr. Barbra Hanna, FACOG, NCMP, put it, “negative body image, poorer self-esteem, and feeling less control over their life” compound with other “menopause symptoms that can […]
Losing your hair might not be the most medically concerning symptom on its own, but its effects on mental health, social well-being, and personal identity can’t be understated. As Dr. Barbra Hanna, FACOG, NCMP, put it, “negative body image, poorer self-esteem, and feeling less control over their life” compound with other “menopause symptoms that can make one feel as if an alien has invaded their body” to make the time around menopause extremely difficult for many women. Many women suffer for years with thinning hair and widening parts before seeking help, sometimes only to have their concerns dismissed.
Menopause-related hair loss is normal. That being said, it is absolutely worth consulting a physician if it concerns you. It can sometimes be prevented or treated, and while an emotional subject, it should not be a cause of embarrassment.
Androgenetic Alopecia, or Pattern Hair Loss
Depending on the study, the prevalence of alopecia in women has been found to be between 20 and 40%. It seems to affect white women more than those of Asian or Black descent. And while it can occur at any point in life, it overwhelmingly occurs following menopause or 12 months of amenorrhea (absence of menstruation).
Provided by bass instruments, the low-frequency parts of music tend to contribute the beat we actually dance to. Songs with lower-frequency baselines tend to have higher perceived “groove” ratings, but what if the frequency is so low that it falls outside humans’ audible range?
Researchers from McMaster University, Fitchburg State University and the Rotman Research Institute set out to test just that. Utilizing so-called very-low frequency (VLF) sound, researchers fitted participants with motion capture headbands at a live concert for electronic music duo Orphx and had them fill in pre- and post-concert questionnaires. VLF speakers were turned on and off every 2.5 minutes throughout the 55-minute performance, and the recorded mo-cap data was used to calculate participants’ head movement speeds in the presence or absence of VLF.
The resulting data showed that audience participants moved an average of 11.8% more when the VLF sound was on versus off. The researchers also performed additional experiments to confirm that the VLF was inaudible.
If it can’t be heard, how can VLF sounds contribute to a sense of groove or make people dance more? The researchers suggest that VLF sounds lead to changes in behaviour through subconscious processes involving our brains’ vestibular, vibrotactile, motor and reward systems. Sounds are mainly processed through our auditory pathways; however, low-frequency sounds are additionally processed via the vibrotactile and vestibular pathways.
While known for controlling our balance and proprioception (sense of where our bodies are), the vestibular system has previously been implicated in perceptions of rhythm. In addition, both the vestibular and vibrotactile pathways have close links to our motor systems. The researchers believe that one, or more, of these pathways, are responsible for the dance-inducing effects of VLF sound.
There are more than 3000 species of snakes on Earth, ranging from the Barbados threadsnake at roughly 10 cm long (about the same as a deck of cards) to the reticulated python at around 6 m in length (almost as tall as an adult male giraffe!). Luckily, only about 600 are venomous, and only around 200 are venomous enough to seriously harm or kill a human.
Despite the existence of hundreds of venoms, nearly all snake venoms fall into one of three categories, depending on how they affect us: neurotoxins, cytotoxins or myotoxins.
Neurotoxins are common to the Elapidae family of snakes, which include cobras, mambas, coral snakes, and copperheads. They work on the nervous system by disrupting the electrical impulses that our nerves and muscles use to function.
Neurotoxins can mess with our neurons in a few different ways. Imagine your neurons like a lamp plugged into an electrical socket. For the lamp to function normally, it should be able to turn on and off at different times. With α-neurotoxins, it’s as if someone put a babyproof cover on the socket, preventing us from plugging our lamp in at all. The result? No light. On the other hand, with dendrotoxins, the lamp is plugged in, but no electricity flows from the socket to our lamp. Again, no light. But with fasciculins, it’s like the lamp’s plug is stuck in the wall. Constantly activated with no off switch, even though we want to go to bed.
Vipers favour the use of cytotoxins—venoms that directly damage cells. Some common types include phospholipases, which disrupt cell walls, and hemotoxins, which affect the circulatory system. Some hemotoxins trigger the destruction of red blood cells, while others affect the clotting factor of blood—either by making blood too clotted and thick to flow or too thin to ever clot and stop external bleeding.
Myotoxins are less common in serpent physiology but are found in certain species of rattlesnakes. They contain basic peptides (chains of amino acids too short to be considered proteins) that directly disrupt the flow of charged molecules our muscles rely on to contract.
With such a wide range of venom types and mechanisms of action, it’s no surprise that nearly every snake species needs a tailor-made antivenom. Luckily, Canada only has four native species of venomous snakes.
Nonetheless, it can be pretty tricky to identify snakes reliably in the wild. So, if you’re ever on the receiving end of a snake bite, seek medical attention immediately! Do not try to catch the snake to bring with you—some help for your doctors in identifying your attacker is not worth a second (or third, or fourth) bite.
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.
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.
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.”
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.
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.
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.
Ada McVean 