by Haley Richardson
Climate change: it’s something we hear about nearly every day whether it’s in class, on the news, or in casual conversation. While most people know that climate change is not a good thing, many are not aware of the specific implications of the changes in the earth’s temperature and atmosphere. One of the more major yet less regarded effects of climate change is how rising global temperatures can change the habitable range of a species. More specifically, infectious agents, as well as the organisms that carry them, can begin to populate areas of the world that they were not able to before, spreading disease to regions that were formerly too cold for them to survive.
Infectious agents, like all other biological entities, have specific environmental factors that determine where they can grow and reproduce at the fastest rate. Often, these environments tend to be hot areas with a high quantity of water or a humid atmosphere. As a result, the areas of the world with the most infectious diseases tend to be the tropics, particularly after monsoon season, which results in large amounts of rain. However, as global temperatures rise, the formerly hot, humid areas of the tropics may become too dry for many disease-carrying organisms to handle, causing them to migrate to more temperate zones. By contrast, regions formerly too cold to have these disease-carrying organisms will become warmer and more humid, allowing the range of the species to expand further north. Furthermore, large-scale extreme weather events such as El Niño, La Niña and others are already increasing in frequency, bringing with them new organisms with new diseases to colonize areas affected by these phenomena.
For example, the infection rate of the malaria virus is primarily attributed to the species that carries it: mosquitoes. Although many parts of the world contain mosquitoes, only a specific species of mosquitoes in the Anopheles genus can carry the malaria virus. Malaria-carrying Anopheles primarily live in sub-Saharan Africa, where the temperature and humidity of the region are ideal for the mosquito’s life cycle. However, as climate change causes global temperatures to rise, Sub-Saharan Africa is expected to become too arid for the mosquitoes to thrive, and so scientists are predicting that they will migrate as far north as Southern Europe.
The consequences of the spread of diseases like malaria could be astronomical, especially in less developed countries where access to health services and vaccinations are limited. Additionally, by migrating to previously uninhabited regions, the Anopheles mosquito would be spreading the malaria virus to populations that had not had a chance to build up an immunity to the disease, amplifying its effects. Other similarly transmitted diseases such as yellow fever, sleeping sickness and dengue fever, as well as bacterial infections such as cholera and Lyme disease, are also predicted to spread at a faster rate and into previously uninhabited areas as global temperatures rise. All of these diseases in their newly acquired ranges could spell disaster for many people worldwide, and in some areas they already have.
However, lest this article be all doom and gloom, there are several initiatives that the international community has proposed to manage the spreading of infectious diseases due to climate change. Besides the obvious solution of slowing down carbon emissions to decrease the rate of rising global temperatures, scientists and lawmakers alike have come up with systems to monitor the spread of infectious diseases to ensure that responses to outbreaks will be faster and more efficient than before. Institutions such as the Pacific ENSO Application Centre have developed early-warning systems that could detect extreme weather events that could lead to outbreaks of disease, allowing them to inform governments to prepare relief in advance and educate the public on disease prevention. Other institutions such as the World Health Organization actively provide relief to diseased-ravaged areas, and lobby governments to provide funds and support to affected regions. Furthermore, scientists around the globe are working to develop vaccines to the planet's most deadly diseases, as well as ways to mass produce them in the most cost-effective manner. Thus, as global climate change alters the environment (perhaps irreparably) at a frighteningly fast pace, we can at least hope that human progress will move even faster.
by Amy Haddlesey
As students, we are no strangers to staying up late to do schoolwork or the hardships of getting up early for an 8:30 class. A good portion of the population will find one of these activities easier than the other, which means that people can fall into one of two camps: night owls or early birds. The population is said to have a normal distribution when it comes to how we organize our behaviour within the 24-hour day, with most of us in the middle of the two extremes, but there are still individuals that find themselves leaning towards one or the other. The term ‘chronotype’ is used to describe your preference for wakefulness, which is divided into late chronotypes (LCs), intermediate chronotypes (ICs), and early chronotypes (ECs). ECs are characterized by their difficulty with staying up late, and LCs are characterized by their difficulty with getting up early. Chronotype is both age and sex-dependent. Interestingly, a higher percentage of females are ECs.
Chronotype-specificity is dictated by the interplay between neural circadian rhythms and homeostatic oscillators. Both essentially involve regulating the cellular processes involved in telling our bodies when to sleep, wake, and eat. While circadian rhythms, or the “body clock”, can respond to or be affected by external factors (eg. sunlight), the homeostatic oscillators are considered internal, independent regulators. However, it is the interplay between the two that regulates the overall fluctuation between sleep and wakefulness over the course of each day. Recent research into the genetic basis of our inner clocks has revealed that our circadian rhythms are important time reference systems that interact with the environment. Understanding how circadian clock function is most affected could lead to helpful interventions in mediating clock dysfunction improving human health and welfare. In this study, more than 80 different genes were shown to be expressed differently between late and early chronotypes in fruit flies. Furthermore, it wasn’t expression alone that separated the groups; there were also different genetic variations present between late and early chronotypes. Overall, there are many factors at play in determining your preference for how you organize your day that may be beyond your control.
Studies have found that the differences between chronotypes extend beyond sleeping preference. Different chronotypes are also associated with differences in cognitive performance, gene expression, endocrinology, and lifestyle. Most notably, LCs tend to suffer from a conflict between internal and external time (‘social jetlag’) that may cause them to suffer more mental stress. In other words, a night owl’s tendency to sleep through the day and stay up late comes into conflict with the typical hours of the social day, which may cause LCs to experience jet lag-like symptoms as they try to adjust. Similarly, LCs may have to adjust to working hours or school hours as well. One paper suggested that with an increased understanding of chronotype-specificity, work schedules could ideally be designed to fit your wake/sleep schedule. It is important to note, however, that most workplaces have to fit into regular business hours, and so it’s unclear how many workplaces could be suited to this “customizable” workday and how large of a range can be accommodated. With that said, there are some businesses that set formalized flex hours, where there are certain hours you must be in the office, but you can shift the surrounding hours to your own preference (come in late so you leave later versus coming in early so you leave earlier).
As much as we try, we can’t always control our schedule and that means we are sometimes forced to conform to a routine at odds with our chronotype. A recent study involving adolescents has shown evidence linking chronotype and academic performance. During adolescence, our chronotypes are typically at our latest, as might be expected with the typical tendency of teenagers to stay up later and sleep in later when compared to other age groups. As discussed, a late chronotype can mean a mismatch between our circadian clock and the early school clock. As a result, it was found that late chronotypes generally have lower grades. This finding is especially interesting when there isn’t an agreed upon relationship between early and late chronotypes and IQ. Instead of a difference in IQ, these lower test grades could be due to the circumstantial or ‘social jet lag’ discussed earlier causing sleep deprivation in LCs. The effect of chronotypes seem to be strongest in the morning and disappear in the afternoon, which is in line with views that LCs struggle to adjust to an earlier schedule.
So what can we do with this information? There are many strategies recommended to improve sleep quality including a consistent sleep schedule or reducing your exposure to blue light before bed. However, it may be that these findings indicate a need for schedules better suited to our natural bodily rhythms that could lead to positive outcomes for public health and productivity. It’s hard to imagine what tangible programs or policies could be established with this information, but it’s an interesting subject that may be worth our attention.
by Tayyaba Bhatti and Wara Lounsbury
With the recent chill of November comes the ever-looming threat of exams. During these gloomy times we can find solace in the thoughts of the upcoming holidays. For some us, that entails a warm and cozy time spent with family and for others it means a trip to warmer climates. As pleasant and comforting as vacations are supposed to be, there is one unwelcome side effect: jet lag, which often casts a pall on the joyous times. But what exactly is jet lag? Previously believed to be a state of mind, jet lag was later discovered to be a physiological phenomena. Jet lag is the sensation of fatigue during daylight hours that arises due to the slow adjustment of our circadian clocks to new time zones. Circadian clocks are made up of the molecular pathways that dictate when we sleep, move, and eat, and are present in almost every cell in our body. Having to adjust these circadian clocks to a new time zone and then back to the original one within a span of a couple of weeks can take a toll on our bodies. However, there may be hope for frequent flyers in the future according to a recent publication in the journal Cell Metabolism.
The research started with an initial question: how do all circadian clocks show the same time? Universal clock resetting cues like feeding-fasting and temperature cycles have already been discovered. Dr. Gad Asher, the lead researcher on the study, decided to study oxygen consumption as a potential cue because all cells in our body use oxygen. The mice were placed in special cages to measure oxygen consumption and monitor blood oxygen levels. In order to simulate jet lag induced by traveling to a different time zone, researchers shifted the light-dark cycles of mice 6 hours ahead. They found that decreasing oxygen levels 12 hours before or 2 hours after the light-dark cycle shift helped mice to adapt to their new light-dark cycle more easily and recover from jet lag faster.
Furthermore, the researchers investigated the cellular route by which oxygen modulates the circadian clocks by removing a protein (HIF1α) that tells cells how and when to use oxygen. They discovered that when this protein was removed, the mice were no longer able to achieve the faster adaptation of the light-dark cycles upon exposure to decreased oxygen levels. Thus, they determined that HIF1α mediates the effect of oxygen on the circadian clocks.
This study incites a lot of new research questions. Most of us would want to know whether these findings can be applied to humans as well, or whether it's just mice that now have a cure for their jet lag. Another question that comes to mind is whether changing the oxygen level would work best before, during, or after a flight. Also, would raising oxygen levels have the same preventative effect as lowering oxygen levels? However, the most important question is how this research can be relevant to us.
Most of us experience chaotic sleep schedules during midterm and finals seasons. Some of us even suffer chronic fatigue due to ever-shifting circadian clocks during the year to meet deadlines or to socialize within our networks. Others struggle to maintain the heavy coursework with part-time jobs and night shifts. Since HIF1α also plays a role in various other cellular processes, this research may be extended to help explain the underlying effects of these phenomena surrounding fatigue. However, this requires further studying of the protein, its interactions within the body, and the application of oxygen consumption alteration to humans. For now, it appears just Stuart Little and his friends can rejoice over their jet-lag free vacations.
by Greg Eriksen
Editor’s Note: Lifebeat previously published an article called The Science of a Hangover: Homecoming Edition, but here is a more in depth explanation of the theories behind why hangovers happen and why different alcohols lead to different hangovers.
The hangover: the price many of us pay to have a night out that we probably won’t remember. After a week of working hard, we celebrate on the weekend only to wake up on Sunday feeling miserable. We then proceed to struggle through the headaches, dizziness, and nausea with the help of coffee and Advil. Although the science behind hangovers is not completely understood, there are many contributing factors that help us understand why those awful Sundays occur. Furthermore, we may be able to reduce the effects of the hangover based on the alcohol we choose to drink!
Often the headaches and dizziness associated with a hangover come from being very dehydrated. Alcohol is a natural diuretic which works by decreasing the body’s anti-diuretic hormone. This hormone is responsible for the reabsorption of water. Therefore, when high levels of alcohol are consumed, we stop reabsorbing water, and thus have an increasing urge to pee. This effect explains why we all have so many untimely trips to the bathroom in one night! Consequently, the total fluid loss can give you painful headaches the next day.
Another contributing factor to the symptoms of a hangover is the result of ethanol (alcohol’s primary component) metabolism. Upon ethanol consumption, the enzyme alcohol dehydrogenase converts ethanol and NAD+ to NADH and acetaldehyde. The high concentration of NADH inhibits gluconeogenesis: the generation of glucose. Essentially, the first step in the gluconeogenesis involves the conversion of NAD+ to NADH. However, with a high level of NADH already present due to ethanol consumption, this reaction is unfavourable, and therefore gluconeogenesis will not occur. The outcome can lead to low levels of blood sugar known as hypoglycemia. As a result, when an individual wakes up with a hangover, they may be hypoglycemic, which causes dizziness and nausea--sound familiar?
As I mentioned before, the metabolism of ethanol produces NADH as well as acetaldehyde. The latter of the two molecules is hypothesised to be the primary reason we all experience hangovers. Research has shown that acetaldehyde is 10-30 times as toxic as alcohol. In effect, we are introducing toxins into our bodies for fun. The toxic effects of acetaldehyde may include sweating, dizziness, and even memory impairment. Due to acetaldehyde’s high toxicity, our bodies are very efficient at converting it to a more stable compound known as acetate. However, drinking in mass consumption (much like what is done on homecoming) produces a lot of acetaldehyde, which allows its adverse effects to take place.
Although waking up with a hangover can be a common occurrence, the alcohol we choose to drink may influence the hangover’s intensity. Congeners are substances within alcohol that are formed during the fermentation process. They often contribute to the flavour of the beverage we choose to drink. However, they are also linked to the effects of hangovers. In a previous study, researchers decided to look into the effects of different alcohols on people. They gathered 95 healthy alcohol users and served them 3 different beverages on 3 different nights. The first night, all 95 individuals were given the same undisclosed alcohol to “acclimate” to drinking. On night two, they were given vodka or whiskey with a consumption that put them 3 times above the legal limit for driving. Finally, on the third night, they were given a placebo drink with no alcohol in it. Once the study was done, the participants who drank whisky reported worse hangover symptoms than those who drank vodka. Whisky also contains considerably more congeners than vodka. Furthermore, research published in the British Medical Journal discovered a connection between hangover severity and amount of congeners. Accordingly, the amount of congeners for each alcohol has been recorded, with brandy, red wine, and whisky having considerably more congeners than vodka, gin, and white wine. Interestingly enough, the drinks that give the worst headaches tend to be darker and more flavourful. Furthermore, drinks that include carbonation tend to absorb faster than distilled drinks, and ultimately get you more drunk. Therefore, it seems that the best drink to buy in the club is also the cheapest one: vodka water.
Overall, no matter the facts, many of us will still choose to drink on a night out regardless of the effects in the morning. In a sense, drinking on that Saturday night is just borrowing happiness from Sunday. However, we can help ourselves survive the hangover by choosing the right kinds of alcohol! There is nothing wrong with saving a little bit of money and drinking vodka water instead of another jäger bomb!