Static Shocks Are a Seasonal Occurrence, but Science Can Help Us Avoid Them

5 minute read
Originally posted here: https://mcgill.ca/oss/article/environment-general-science/how-can-i-stop-getting-static-shocks

If you live in Canada, you know what a nightmare winter can be for your hair. No, not because of hat hair, (or at least not entirely because of hat hair), but because of static electricity! All those big scarves and wool hats really do a number on the frizziness of our hair. But even if you’re bald you’ve probably noticed that the number of times you get shocked when reaching for everyday items, like keys, doorknobs and shopping carts, increases in the winter too. There’s some interesting science behind these seasonal shocking scenes, and how you can stop them. 

The number one factor influencing how many zaps you get is humidity. But to understand why we need to review a bit about electricity.  When two objects made of different materials come in contact with each other, like your hair and a hat, for example, electrons can transfer between them. The more prolonged contact, the more electrons move, creating an imbalance of charges between your hair and the hat.

Whether the electrons move from your hair to the hat, or vice-versa, depends on something called the triboelectric series. It’s basically a ranking of different materials based on their tendency to lose or gain electrons. Some things, like rubber or acrylic, are very likely to gain electrons and become negatively charged. Whereas other things, like hair, glass or wool, are more likely to lose electrons and become positively charged. In the case of your hair and a wool hat, since human hair is higher on the triboelectric series, the electrons flow from your hair to the toque.

The problem is that same charges repel each other, so now that your hair is full of positive charge, it’s rather unstable. That’s why, when you get near something conductive, like a metal doorknob, electrons from the knob will “jump” to your hair to neutralize the charge, shocking you in the process. It’s also why your hair stands on end when statically charged. The strands are repelling each other!

Why do charges build up in our hair or clothes, but not in other materials? Because insulating materials, like plastic, fabric or glass, will hold charges quite well, while conducting materials, like metals, will not.

Water happens to be an excellent conductor, so in the spring, summer and fall, when the air in Canada holds a lot of moisture, any negative charges built up on your body can jump to the air (or from the air to your body, either way results in a shock) whenever they want. We don’t even notice these numerous small jumps. But in the winter the air is drier, so the charges simply sit on your skin, waiting for you to approach another conductor (like your car or your girlfriend) to leap to freedom.

Read this to hear about why winter air, especially indoors, is so dry!

When thinking of how wet or dry the air is, we tend to only consider humidity. But there’s another metric that’s important: dew point. The dew point is the temperature at which the air is totally saturated with water. When temperatures fall below the dew point, water condenses on solid surfaces, forming dew in the summer, or frost in the winter (hence why the dew point can also be called the frost point). Warmer air can hold more moisture, meaning that when temperatures are low, the dew point and the actual temperature are quite close. Conversely, when temperatures are high, the dew point and actual temperature are far apart.

Why does dew point matter? Because temperature, dew point, and relative humidity (that % you see on your weather app) are closely linked.

As an example, as I’m writing this, the temperature outside is -9 ˚C, and the relative humidity is 57%. Using the chart below, or less confusingly, this online calculator, we can find that the dew point is -16 ˚C. This tells us that if we go outside it won’t feel muggy because the temperature is significantly above the dew point and the air isn’t saturated with water.

However, our furnaces bring that air into our homes and heat it. This doesn’t change the dew point, but it does change the temperature and the relative humidity. What was a relative humidity of 57% at -16 ˚C becomes a relative humidity of only 7% at 20 ˚C. That’s some really dry air.

Now importantly, the only thing changing here is the relative humidity. The absolute humidity is the same since the furnace doesn’t add or remove any moisture when it heats the air. So even though the air inside and outside is equally dry, it feels much dryer inside due to the relative nature of relative humidity. 

Source: https://www.ncbi.nlm.nih.gov/books/NBK143947/

One of the easiest ways to counteract the shocks that come with these Saharan conditions is to run a humidifier. Increasing the relative humidity of your home will allow more charges to dissipate into the air and avoid the shocks that come with letting them build up.  Side note: If you think desert-like is a bit too harsh to describe the indoor conditions in the Canadian winter, think again. The average relative humidity of the Mojave Desert is 28%, a full 21% higher than my house right now. No wonder I have chapped lips. 

If a humidifier isn’t cutting it for you, you could also try swapping out your rubber-soled slippers for ones with leather soles. Since leather is a better conductor than rubber, this will prevent charges from building up to the same degree. Similarly, try to surround yourself with more cotton. As it falls in the middle of the triboelectric series, it doesn’t have much of a tendency to gain or lose electrons, so won’t build charges like wool or fur.  

Still really worried about static shocks? You could always purposefully discharge yourself every once in a while. If you carry a metal object like a coin, key or paper clip around with you, and touch it to something metal in your house, any electrons stuck to your body will flow through the metal and away, preventing the “jumping” effect that causes a shock. 

Last, but not least, you can always rely on anti-static products to take the charge out of your hair and clothes. Dryer sheets contain chemicals like dipalmitoylethyl hydroxyethylmonium methosulfate that release positively charged ions when heated to neutralize the negatively charged electrons on your clothes. You can even rub your hair gently with one to remove static! Anti-static sprays and anti-static guns can also be used to keep static to a minimum wherever you need to, from your favourite dress to your Rubber Soul vinyl. 

Source: http://www.saapedia.org/en/saa/?type=detail&id=4070

Why Mosquitos Bite You and How to Make Them Stop

Originally posted here: https://mcgill.ca/oss/article/health-technology/why-mosquitos-bite-you-and-how-make-them-stop
15 minute read

Summertime means hammocks, BBQs, fireworks, and mosquito bites.

At least it does for me. Those rotten little suckers seem to just love me. They’ll flock to me even when there are three other people sitting in my backyard. What is it about my blood that they seem to enjoy so much?!

Let’s take a look at the science behind mosquitos and try to answer two questions: Why do mosquitos bite certain people, and what should we do to make them stop?

Take-home message:
– Blood type may or may not play a role in attracting mosquitos
– Products using DEET, icaridin, PMD, metofluthrin, and some blends of essential oils are effective at repelling mosquitos
– Bug zappers, sonic devices, citrosa plants, B vitamins, and scent-baited traps are not effective at repelling mosquitos and should be avoided

Mosquito isn’t a Species, it’s a Group

Before discussing the nitty-gritty of mosquito attraction, we need to realize something. While we tend to think of all flying bugs with proboscises as mosquitos, in truth there are more than 3500 species categorized into 112 genera that fall under the moniker of mosquito.

With such variation in species comes a lot of variation in habitats, behaviours, and risks. For instance, malaria is transmitted to humans only by mosquitos of the genus Anopheles, while yellow and dengue fever are transmitted by those in the genus Aedes. Canada is home to roughly 82 species of mosquitos belonging to the genera Anopheles, Culex, Aedes, Mansonia, and Culiseta. Some mosquitos are anthropophilic, meaning that they preferentially feed on humans, while others are zoophilic and preferentially feed on animals.

We’re typically taught to remove standing water from our property and avoid boggy or marshy areas (good luck in Ontario) to avoid mosquitos, but some species of these bugs don’t exclusively lay their eggs in water. We tend to think of mosquitos being at their worst in the summer, at dusk and dawn, but different species are active at different times, and their behaviour can even change from season to season, making it hard to predict when we are at risk of getting bitten.

Something that is true of all mosquito species though is that only the females bite. They require a blood meal in order to produce their eggs. The nasty by-product of this reproductive cycle is that they transmit diseases, and actually kill more people per year than any other animal.

How Mosquitos Track You

Mosquitos home in on their dinner-to-be by following a few different signals. The first clue that something biteable is nearby is the detection of a COplume exhaled on the breath of mammals and birds alike.

The amount of CO2, however, does not affect the attractiveness of a specific target, so even if you’re a human who produces more COthan others (such as those who are larger or pregnant) that alone is not responsible for your irresistible-to-mosquitos aura. This makes sense since large animals like cows naturally produce much more COthan humans, yet many mosquito species still prefer to bite us.

Mosquitos will track a CO­plume until they encounter host-cues. These first of these clues that a target is close by is usually smells emanating from the skin, which we’ll discuss more in a second. As they get close to the source of a smell, mosquitos will then detect and head towards heat and moisture signals emanating from a body.

Source: https://www.sciencedirect.com/science/article/pii/S096098221500740X

We don’t know whether changes in body temperature affect how attractive you are to a mosquito, but we do know that sweating increases the volatile compounds on your skin that they love, and that anhidrotic people, or those who show decreased sweating, are less attractive to the pests.

The main mosquito-cues that can differ between humans are the olfactory ones. While it’s easy to swap your shampoo and soap for unscented varieties that won’t attract mosquitos like the sweet-scented ones do, a lot of the smells that mosquitos sense are innate to your physiology and sadly are not something that we can really change.

A few of these odorous chemicals include ammonialactic acidsulcatone, and acetone. For many of these compounds, however, higher concentrations don’t equal greater mosquito attraction. Instead, they modulate the attractiveness of other substances. For instance, lactic acid has been shown to increase mosquitos attraction to ammonia and CO2.

While an animal may produce similar-to-human levels of CO2, humans tend to produce more lactic acid than primates or cows. This lactic acid synergistically increases the appeal of CO2for anthropophilic mosquito species, while actively dissuading zoophilic species from landing on you. Conversely, ruminants like cows also exhale1-octen-3-ol, a substance that attracts zoophilic species of mosquitos. In a demonstration of this, skin rubbings taken from cows were made just as attractive to anthropophilic mosquitos as skin rubbings from humans via the addition of lactic acid.

The Role of Blood Type

There has been significant debate over the role blood type plays in attracting mosquitos. Initially, a 1972 study using Anopheles gambiae found that mosquitos preferred those with O type blood (O>B>A>AB). But a 1976 study using the same mosquito species did not confirm this.

1980 study examined 736 patients and found that while those with A type blood made up 17.6% of the control group, they made up 29% of the malaria cases. Conversely, those with type O blood made up 33% of the control group but only 22% of the malaria cases. While this alone does not tell us whether or not certain blood types are more likely to be bitten by mosquitos or contract malaria, it does point to blood type playing some role in mosquito attraction.

Some clarity came with a 2009 study done with Aedes albopictus that found a similar pattern to the original 1972 study: O>B>AB>A. The researchers also compared the mosquito-attracting ability of those who secrete substances corresponding to their blood type onto their skin, versus those who do not. Their theory was that these blood type-specific secretions could explain mosquito’s ability to find their preferred type O prey. Their results, however, showed an order of preference of O secretors>A nonsecretors>B secretors>O nonsecretors>A secretors>AB secretors>B nonsecretors, which do not correspond to the blood type preferences established.

Concerning blood type’s role in attracting mosquitos, we’re stuck with the often-written phrase more research needed. Given the conflicting results and relatively small sample sizes of these studies, we cannot make definitive conclusions. Not to mention that we have no idea how mosquitos are able to detect a target’s blood type from a distance.

If mosquitos do truly target those with type O blood, the authors of this study theorize that preference could have evolved due to the prevalence of type O blood in African nations. The three most populous African nations are Nigeria, Ethiopia, and Egypt, and the percentage of their populations with type O blood are 51.3%, 39.0%, and 52.0% respectively.

How to Avoid Getting Bitten

Anyways, even if we knew what blood types attract mosquitos, you can’t change your blood type. So, what can you do to get some relief from these minuscule menaces?

First, it’s important to remember that just because you’re not forming welts doesn’t mean you’re not getting bit. Not all bites will lead to the familiar welts, so even if you’re not covered in itchy bumps, if you’re near mosquitos you should be using repellant.

Things That Work

Physical barriers should be your first line of defence against mosquito bites. Install screens on your windows, doors, tents, and RVs, and cover children’s cribs, playpens, and strollers with fine mesh to keep mosquitos out.

You can get specialty meshes and clothing treated with permethrin, an insecticide, for adults in Canada. The anti-mosquito effects of the chemical will last through several wash cycles, but permethrin-treated objects should never be used for or around children, including screens or mosquito nets that they may interact with, as their safety has not been evaluated.

In general, you should strive to wear light coloured clothing, and cover as much of your skin as the heat will allow. Mosquitos are better able to orient themselves towards darker targets, so skip the Nirvana t-shirt and try on a white tee instead.

Flowery and fruity scents will attract mosquitos greatly since they feed on flower nectar (in addition to us) but even non-botanical scented products should be avoided whenever possible. This includes (amongst many others): shampoo, soap, conditioner, shaving cream, aftershave, perfume, deodorant, hand cream, makeup, and even laundry soap and softener.

In terms of repellants, the good news is that you have more options on the market than ever. The bad news is that only some of them work.

DEET

N,N-Diethyl-meta-toluamide, better known as DEET, has been the standard ingredient in commercial bug sprays since 1957 when it made the jump from military to civilian applications. While it used to be thought that DEET interfered with a mosquito’s ability to detect lactic acid, more recent research has found that mosquitos detect and avoid DEET directly. Much like I do with vinegar.

Misguided fears about DEET’s safety have spurred some to move towards other mosquito repellants, and while there are other effectual repellants, none work as well or for as long as DEET. In terms of its safety, DEET has been more thoroughly studied than any other repellant and when used according to guidelines is quite safe.

When utilizing DEET-based repellants it’s important to pay attention to the concentration of DEET in the product. The Government of Canada recommends that no concentration over 30% be used on anyone and that only formulations containing up to 10% be used on children aged two to twelve (up to three daily applications) and aged 6 months to 2 years (only one daily application). Babies under 6 months should be kept mosquito-bite free through the use of nets and screens rather than repellants of any type.

Icaridin 

Icaridin, also known as picaridin, is a safe alternative to DEET popular in Europe and recommended by the Government of Canada for use against mosquitos and ticks on anyone over the age of 6 months. This study showed that products with 9.3% icaridin can repel mosquitos for up to 3 hours, while this study showed that a 10% concentration repelled mosquitos for more than 7 hours. This is comparable to the 5 to 7+ hours of protection provided by 7-15% DEET products, although DEET has been more widely studied. Contrarily this study found a 10% icaridin repellant rather ineffective. If you find them effective, icaridin-based products could be particularly useful for small children who have exceeded their daily recommended applications of DEET-based products but still need to remain outside.

Citronella

Citronella has long been the standard of backyard BBQs and picnics in its candle form, but in addition to the coils and candles designed to keep mosquitos out of a particular area, there are also repellants that contain citronella oil.

Citronella oil is made mostly from 2 species: C. nardusand C. winterianus, and contains many different chemicals, the most notable in terms of their insect-repelling nature include camphor, eucalyptol, eugenol, linaloolgeraniol and citronellal.

While it’s citronellal that provides the flowers with their characteristic lemony scent, a 2008 study’s findings suggest that it is actually linalool and geraniol that provide the bug-repelling effects. The researchers compared candles made of 5% citronella, linalool, and geraniol, and found the geraniol and linalool candles much more successful at repelling mosquitos than normal citronella (85% and 71% versus 29% repellency rates over 3 hours). This study likewise confirmed straight citronella candle’s inability to effectively repel mosquitos alone.

This study examined three mosquito repellants that contained citronella and found them all significantly less effective than formulas containing DEET or icaridin, and this study examined 3 wearable bracelets that claimed to emit geraniol and found them as effective as using no repellant at all.

So while it could be useful to burn a geraniol or linalool candle while you’re sitting outside, you should probably still backup your protection with an effective repellent.

P-Menthane-3,8-diol (PMD)

Products with p-Menthane-3,8-diol, a chemical found in small amounts in oil extracted from the lemon eucalyptus tree, have generally (studies 1,2,3) show it to be as effective as DEET and icaridin. The Canadian government recognizes PMD’s repellency effects on blackflies and mosquitos but recommends against using PMD-containing products on anyone younger than three.

Soybean and Essential Oils 

Soybean oil is perhaps the strangest bug-repelling ingredient on this list, but repellant formulations containing mixes of soybean oil and various essential oils have been rapidly making their way onto the Canadian market. While the soybean oil itself does not repel mosquitos, it works in tandem with the essential oils also included in the repellants to stabilize their volatility.

This study found that a formulation including soybean oil, coconut oil, geranium, and vanillin repelled mosquitos for more than 7.2 hours. However, the same study, and another, showed that other formulations also containing soybean oil, as well as other various essential oils (menthol, eucalyptus, lavender, rosemary, sage, etc.) worked very minimally.

This points to the particular essential oils and other ingredients in the repellant making the difference rather than the soybean oil itself. This makes sense when you consider that the geranium included in the effective soybean repellant was likely citronella, and that vanillin has been shown to increase the repellency effects of citronella.

The Government of Canada doesn’t place any age restrictions on formulas containing soybean oil but recommends not using essential oil formulations on those younger than 2. So, you’re free to experiment with different products using different ingredient blends and see which works, but make sure to turn to something a bit more reliable when actually venturing into the woods.

Metofluthrin 

If you’d rather wear a clip-on device than use a mosquito repelling lotion or spray, your only good option is those that emit metofluthrin. This 2017 study examined the efficacy of 5 wearable anti-mosquito devices and found that only the metofluthrin at a concentration of 31.2% effectively repelled mosquitos. Much like citronella candles, however, clip-on devices work by creating a fog of mosquito-repelling chemicals around you. This means that they will only be effective for times when you’re sitting still.

Things That Don’t Work

While components of citronella oils may be effective repellants, citrosa houseplants are not. Nor are the sonic mosquito repelling products that claim to play sound at frequencies that will drive mosquitos away. I’ll let the authors of this paper sum up the evidence for these products: “We are not aware of any scientific study showing that mosquitoes can be repelled by sound waves and therefore we consider these devices as the modern equivalent of snake oil”.

While synthetic mosquito lures that attract the bugs just as well, if not better, than humans have been developed, in practice mosquitos continue to be attracted to humans even when these devices are used. Thus, their use is not recommended by the Canadian Government. Likewise, handheld or mounted bug zappers certainly exist and can be quite satisfying to use for revenge on the bugs that stole your blood, relying on them for protection is not a good idea.

You may have heard that eating bananas can alternatively make mosquitos more or less attracted to you. The claims of banana’s repelling power stem from their high vitamin B6 content, but a 2005 study tested the effects of vitamin B consumption on mosquito attraction and found absolutely no effects. In terms of bananas attracting power, those claims come from octenol content, a chemical that does indeed attract mosquitos. But, octenol isn’t unique to bananas, it’s found in many foods, and no studies have been done that prove consuming bananas does make you a bug-target, so keep on munching.

A subtler mistake you may make when selecting your mosquito repellant is to use a product that combines sunscreen and bug spray. While certainly convenient, the problem lies in sunscreen’s need to be reapplied much more frequently than mosquito-repellants. If both products are needed for an outing, it’s recommended that you wait 20 minutes between applying sunblock and repellant.

Basically, to avoid being a mosquito-target you should stay as scent-free as possible, wear light clothes, avoid bogs and use an effective repellent (such as those containing DEET or icaridin). Or, you could always stay inside- I hear its quite nice this time of year.

Cell Phones and Wifi are Perfectly Safe

2 minute read

The idea that cell phones, routers, wireless heart rate monitors, alarm clocks or pretty much any other electronic device will give you cancer is one of the most persistent fears around. The good news is, it’s also one of the most baseless.

Read the entire article here: https://mcgill.ca/oss/article/general-science-health-and-nutrition-you-asked/cell-phones-and-wifi-are-perfectly-safe

Lead Bullets Can Harm in More Ways Than One

Bullet Copper Ammunition Lead Brass Shell Ammo

It’s probably not news to anyone reading this that lead exposure is dangerous, but when most of us think of routes to lead exposure we think of leaded gasoline, paints, drinking water or pencils (although pencils do not, and never did, actually contain lead). But there is another means of exposure that’s causing significant issues for certain populations: lead bullets.

Bullets have traditionally been made from lead for several reasons. The metal is cheap and melts at only 327˚C (621˚F) meaning that it can easily be formed into bullets. It is also very dense, so that lead bullets pack a big punch, so to speak. But lead is also toxic.

After an animal is hunted, even if care is taken to remove the bullet from the carcass, lead contamination of the meat can still occur. Part of the problem comes from the fact that lead bullets often fragment into many small pieces that can disperse throughout the tissue. These lead fragments can then be consumed by the humans or pets who eat this meat.

Several studies have shown that when game is hunted, killed, processed and cooked in standard ways, higher-than-normal levels of lead are found in the meals. This lead contamination especially influences those who rely on game meat as their primary source of food, such as those in Greenland, or Indigenous Canadians, or those using food banks for whom donations from hunters are fairly common.

Even occasional game meat eaters, however, can be affected by lead contamination. Health Canada states that blood lead levels below 5 μg/dL are associated with adverse health effects. One study found that those eating one or fewer meals of gamebird shot with lead bullets per week showed blood lead levels of 7.5 μg/dL, and those eating gamebird meat daily showed blood lead levels of 17 μg/dL. But the effects of lead bullets don’t stop with humans.

As it’s fairly common for hunters to eviscerate their quarry in the field and leave behind the unwanted viscera, scavenging animals can feed upon the discarded remains of humans’ prey and ingest lead in the process. This can lead to many of the same symptoms as human lead exposure.

Another route for exposure is found in birds’ gizzards. To help break down their food birds swallow small rocks and store them in their gizzards. The problem is that to a bird a bullet looks a lot like a small rock.

One Italian study found that those who engaged in hunting showed a blood lead level almost double those who didn’t. This could be from the lead fumes that are released when guns are fired or from handling lead ammunition. The same study did not find any relationship between blood lead levels and consuming game meat, which could point to some regional differences in ammunition manufacturing, hunting or cooking styles influencing the amount of lead that makes it into a final dish of cooked game meat.

Lead exposure can also occur in humans that are shot with lead-based bullets, especially since bullets are sometimes left in a victim’s body, either due to lack of medical attention or complications that would arise from trying to remove them. In some cases, symptoms can occur many years after the gunshot wound. To remedy this, a combination of drugs to help eliminate lead from the body, chelation therapy and surgery to remove the bullet are used.

The good news is that non-lead bullets are becoming more popular. Several places have enacted lead munition bans, and one study showed that non-lead bullets were just as effective for hunting animals as lead bullets. Those who handle bullets in their jobs (such as police or military personnel) would benefit from a switch to non-lead-based munitions, but beyond environmental and health benefits, switching away from lead bullets would also have an economic benefit, as this study shows. As for what could be used instead of lead, there are a few options, the most popular of which seems to be copper, but the most interesting of which is definitely depleted uranium.

What is Aquafaba?

Originally published here: https://mcgill.ca/oss/article/nutrition-you-asked/what-aquafaba

Aquafaba (literally the amalgamation of the Latin words for water and bean) is the liquid that remains after boiling legumes. In 2014 a French musician discovered this liquid’s ability to create a foam similar to egg whites, and started a vegan revolution of sorts.

See, for those who do not consume eggs (whether by choice or necessity) certain foods become really difficult to make. Meringues, angel food cake, marshmallows, macarons and some cocktails all rely on eggs for their creation. Egg replacers are common at this point, but they aren’t all the same, and not all of them work for all things. Aquafaba may be just another egg replacer, but it’s got some unique properties that other replacers don’t possess.

The problem is that eggs don’t serve only one purpose in a food. They are what’s called a polyfunctional ingredient, since they serve three distinct and culinarily important functions outside of their taste and nutritional roles: emulsifying, coagulating and foaming. Each of these functions is affected by different conditions like temperature and pH, and each relies on different chemical processes.

Eggs as emulsifiers are the simplest to emulate. In this role the egg serves to stabilize a mixture between two immiscible liquids. Silken tofuflax or chia seeds, bananasmustard (for savoury recipes) or applesauce can all be used as egg substitutes in recipes in which the egg functions only as an emulsifier. The main factor affecting emulsifiers is concentration, with dilute ingredients emulsifying poorly. I really enjoy baking but have largely stopped baking with eggs since eggs mostly function as emulsifiers in my recipes, and substituting them for bananas or “flax eggs” is much cheaper and works just as well!

Eggs as coagulators are more difficult to replace. Eggs coagulate when either heat, strong acids or strong bases cause the proteins in them to denature (lose their structure). The rate and efficiency at which this happens depends on the salt, sugar, and acid content of the food. In eggs the main proteins that coagulate are conalbumin and ovalbumin in the white, and lipoproteins in the yolk. Lots of other proteins coagulate but under different conditions than typically occur during cooking. Egg replacers for coagulation have been attempted. They were made from lupini beanswhey protein, various gums and wheat products, but they haven’t really worked. Replacers made with chia seeds or soy have been a bit better, while replacers made with proteins isolated from whole bovine blood plasma have debatably worked the best but using cow’s blood isolates as an egg replacer probably wouldn’t sit well with most people who use egg replacers.

The foaming ability of eggs is the hardest to replicate. An ingredient’s ability to foam is affected by the method of beating, temperature, pH and water content. Some foods such as soy milk or whey protein can create foams, but these foams are not stable at high temperatures, which is what you need to make angel food cake or meringues.

That’s where aquafaba comes in! It’s vegan, temperature resistant, and made from what would otherwise be waste.

Legumes, like chickpeas, are usually bought either canned and precooked, or dry and uncooked. To cook dry chickpeas you simply boil them for about an hour and a half (pre-soaking dried beans doesn’t actually made them cook faster, so stop wasting your time doing it). During the cooking process the water-soluble proteins and sugars inside the chickpeas are able to travel into the cooking water. The longer you cook the legumes, the more of this migration will occur, as up to about 5% of the dry weight of each chickpea moves into the water. Once you remove your cooked chickpeas, what you’re left with is aquafaba, a sort of protein- and sugar-enriched water.

study has found that the main components of aquafaba are polysaccharides, sucrose, and various proteins. Chemically, this mixture has many of the same components as egg whites, so it makes sense that it can function in many of the same ways. The study also found that some of the compounds most important for aquafaba’s foaming ability are saponins. Saponins, as the name suggests, are characterized by the soap-like foam they produce when shaken.

So how do you actually use aquafaba in a recipe? You basically just whip it up! Using a hand or stand mixer, whip the liquid from your can of legumes or your cooking water for about 3-6 minutes to get semi-firm peaks. You can add some cream of tartar to make the peaks firmer for use in macarons or meringues, or skip the whipping and use it as a binder to make vegan mayonnaise or vegan muffins. The application I’m most excited to try? Aquafaba as a replacement for egg whites in cocktails!

Testing Drivers for THC Is a Lot Harder Than Testing Them for Alcohol

3 minute read
Originally posted here: https://mcgill.ca/oss/article/health/testing-drivers-thc-lot-hard-testing-them-alcohol

To test drivers for alcohol consumption, we have the breathalyzer. It’s fast, reliable, portable and inexpensive, but it will not work for cannabis.

We’ve been testing for THC (the main psychoactive part of cannabis) for a very long time. Our problem is not detecting it, but doing so with a portable machine in a non-invasive way.

As far as existing tests go, urine tests are commonly used for athletes or other employees undergoing drug tests. THC can be detected for anywhere from 1-30 days after use, depending on the frequency of use and the body fat of the individual (since THC is fat soluble).

False positives can result from consuming a variety of things: hemp seeds, ibuprofen, naproxen, and even Prevacid (an antacid). Luckily, a blood test can differentiate between true and false positives. Unluckily, blood tests for casual users of cannabis are only effective at detecting THC for about 1 day after consumption.

An alternative is a hair test. For that, the top 1.5 inches of a strand of head hair is tested. Body hair can also be used, though finding a 1.5-inch piece of leg or arm hair may be difficult. THC can be detected in hair up to 90 days post-consumption, although hair treatments like perms or dyes can affect results. This method is very sensitive and does not create false positives, though it does take longer than a urine test.

The quick and portable test that the Canadian government has settled on using is saliva-based. It’s called the Dräger DrugTest 5000. It requires only 0.28 mL of saliva, produces results in minutes, and even though very little THC passes from the blood into the saliva, the limit of detecting is low enough to still detect the compound.

The DrugTest 5000 is used in Australia, Germany and the UK. But it alone will not be the sole method of measuring intoxication of drivers. In addition to measuring the THC in a driver’s saliva, police will be allowed to perform field sobriety tests, and watch for telltale signs that someone is intoxicated.

Besides cannabis, the DrugTest 5000can detect opiates, benzodiazepines, cocaine, amphetamines and methamphetamines, though it does so for a hefty price: about $6000 per unit. It is only usable when the temperature falls between 4 and 40 ˚C, and can show false results if the subject has recently eaten or smoked.

This study took blood and saliva samples from 369 drivers and tested them using the DrugTest 5000 and traditional blood test methods (UHPLC-MS-MS). The DrugTest 5000 was correct in its assessment about 85% of the time for THC. This means that a false positive or negative reading would be given roughly once in every eight tests. Not really the best numbers.

The rate of false negatives is much better for the DrugTest 5000 when detecting methamphetamine (6.1%), opiates (0%) or cocaine (0%), although the rates of false positives (38.4%, 65.5% and 87.1%) are still quite high. False positives would at least be revealed as falsepositives upon blood test, a better alternative to letting an intoxicated driver free on the roads, but a 1 in 8 chance of a false reading is not what I’d hope for from the technology used by the Canadian police.

Did You Know That Moon Dust Is Incredibly Toxic?

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Originally posted here: https://mcgill.ca/oss/article/did-you-know/did-you-know-moon-dust-incredibly-toxic-humans

There are no aliens on the moon, but that might not stop it from trying to kill us.

Lunar soil is exposed to micrometeorite impacts and because the moon lacks an atmosphere, constant intense solar wind. As a result, the soil is electrostatically charged, so much so that it can levitate above the surface of the moon.

This dust was a problem faced by the Apollo astronauts. It stuck to their suits, following them into their spaceship, coagulating in vents and causing “lunar hay fever” in astronaut Harrison Schmitt.

Lunar dust is problematic because of its intense static charge, but also because of its size. Small particles (5-10 mcg) can accumulate in airways, smaller particles (0.5-5 mcg) can travel right into lung alveoli, and at least in rats, the smallest of particles (<0.1 mcg) can travel through the olfactory bulb right into the brain.

A study has recently shown that human neuron and lung cells exposed to simulated lunar dust experienced DNA damage and cell death, even in very small quantities.

This isn’t totally unexpected. Earth dust can have similar effects, toxic or not. Volcanic ash has been known to cause bronchitis and emphysema when inhaled. But the degree to which lunar dust damaged cells was unexpected. The scientists were at times unable to measure the extent of DNA damage since it was completely destroyed.

Mood Ring Technology Powers Your LCD TV

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Originally posted here: https://mcgill.ca/oss/article/did-you-know-technology/mood-ring-technology-powers-your-lcd-tv

A substance is said to exhibit thermochromism if it changes colour according to temperature. The most popular example of this is mood rings, the hot fashion item of the 70s. These pieces of jewelry contain liquid crystals (the same liquid crystals responsible for your LCD TVs) sealed underneath a (usually fake) gemstone.

As the temperature increases the liquid crystals go through several phases, in which the crystals align themselves in different ways. These different alignments cause light to interact differently with the crystals, making them appear different colours to the ring-wearer.

Mood rings may have gone out of style, but thermochromic liquid crystals are still used in a few ways. Liquid crystal thermometers are essentially strips you place against your forehead. After about 15 seconds one of the boxes on the thermometer will have changed colour, indicating your current body temperature.

Since they don’t need to be inserted into a bum or placed under a tongue, liquid crystal thermometers are often used for babies, as well as for monitoring the temperatures of fish tanks or reptile habitats and home beer brewing systems.

Dragonflies Experience as Much G-Force as Fighter Pilots

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Originally posted here: https://mcgill.ca/oss/article/did-you-know/dragonflies-experience-much-g-force-fighter-pilots

Gravity and the human body have a finicky relationship. Too little gravity and humanslose bone density, experience extreme nausea and become anemic. Too much gravity and humans lose consciousness and die. So how do people who experience hypergravity on a regular basis deal?

Astronauts experience microgravity while on the moon, but also hypergravity (up to 3.2 g) during take off. It’s their Earth-based friends though, fighter pilots, that experience the highest gravitational forces, up to 9 g.

Most people would pass out with 5 g (that’s why most roller coasters don’t exceed 3 g), but fighter pilots wear compression suits to counteract the forces and practice contracting their lower abdominal muscles. These serve to force the blood out of their legs and into their brain, preventing the loss of consciousness.

If a pilot descends too quickly they can experience negative g-forces. The human body is even less tolerant of these, with what’s called a redout, too much blood in the head, occurring with only -2 g.

Some animals are really good at dealing with hypergravity though. When flying in a straight line, dragonflies can accelerate with up to g of force. When they turn corners, this increases to 9 g. And they don’t even need to wear a flight suit.