Knocked Out, Put Under, Anesthetized and Sedated: Different Types of Anesthesia (McGill OSS)

3 minute read

Whether you call it being “put under” or “knocked out”, anesthesia conjures up mental images of deeply sedated patients unable to speak, move or even breathe on their own. However, not all kinds of anesthesia are made equal, and not all kinds carry the same risks.
Read the full article here:

Rats Don’t Really Squeak (McGill OSS)

1 minute read
Originally posted here:

Despite what movies would have you think, rats barely ever make any sounds, at least those that humans are able to hear. Rat’s vocalizations start at around 2 kHz and extend as far up as 100 kHz. For reference, human’s can hear roughly 2-20 kHz, so the vast majority of rat noises made are well into the ultrasonic spectrum. Pet and wild rats alike will seem almost mute, unless put into extreme distress, when they will squeak or shriek audibly. If you record rats with an ultrasonic microphone however, you find that they actually make many noises, to convey everything from joy to dominance and even to laugh!

Getting More Bhang for Your Buck: Cannabis in India

3 minute read
Originally posted here:

As of October 18th, 2019, edible (and drinkable) cannabis became legal in Canada. And yet, almost 5 months later, legal cannabis stores have remarkably little selection. The SQDC (Quebec’s cannabis retailer) only started stocking cannabis beverages one week ago and only offers three types of tea and one type of seltzer. All things considered, it doesn’t seem like drinkable cannabis will be replacing Canadian’s joints, oils, pills or vapes any time soon.

If we look elsewhere however, the story of cannabis drinks couldn’t be more different.

According to the 2017 World Drug Report from the United Nations Office on Drugs and Crime, two of the top 10 cities that consume the most cannabis in the world are in India: New Delhi and Mumbai. The trick here is that much of the cannabis consumed isn’t smoked, but rather drunk in a drink called “bhang”.

Bhang looks somewhat like a shamrock shake or a green smoothie, but tastes (I’m told) of spices and herbs like saffron, fennel, garam masala and more. Strictly speaking, the term bhang refers to a paste made by steeping finely ground cannabis leaves (not buds) in hot milk. This paste can then be eaten on its own or used to create drinks or snacks like pakoras. However, the most popular preparation by far involves adding more milk, rosewater, sugar, nuts and other ingredients to the paste to create a refreshingly cool drink. This drink is often referred to as bhang but is more correctly named according to what ingredients are used, as a bhang thandaibhang lassi or other.

Bhang is especially common during Hindu festivals, in particular Holi, the two-day Festival of Spring, which turns the streets into a sea of colour with coloured paint and water pistols. Cannabis has a rich history in sacred Hindu texts and is named as one of the five sacred plants in the Atharva Veda. The Hindu god Shiva has long been associated with cannabis, and is said to have used bhang for meditative and healing purposes, and is even known as the Lord of Bhang. Cannabis has been used in Ayurvedic medicine to treat conditions ranging from skin disorders to anxiety.

Despite India’s rich cannabis-history, marijuana is actually illegal in the country. Bhang manages to maintain its huge consumption rates due to a legal loophole. It is against Indian law to possess hashish and ganja, but not the leaves of the cannabis plant, which is what bhang is made from. Incidentally, despite its illegality, hashish (made from the resin of the cannabis plant and commonly mixed with tobacco before smoking) is much more popular in India than in North America, while marijuana (the dried buds of the cannabis plant) is much less popular.

Interestingly, cannabis of all preparations was legal in India until 1961, when the Single Convention on Narcotic Drugs moved cannabis to the hard drug category. Prior to this, cannabis consumption had been seen as an inherent part of the religious and social customs of India. Even the colonial British rulers concluded, after commissioning the Indian Hemp Drugs Commission Report of 1894, that “to forbid or even seriously to restrict the use of so gracious an herb as cannabis would cause widespread suffering and annoyance.”

Today any flowering top (called ganja) and separated resin (called charas) from the cannabis plant remains illegal in India, although that is clearly not limiting citizen’s ability to imbibe in THC and CBD. So long as only the leaves of the cannabis plant are consumed, Indians are within their legal rights. As to what happens to the flowering buds once the leaves are removed, well, perhaps I’ll save that for the Indian government to worry about.

Should I pop my blister?

2 minute read
Originally posted here:

If you’re someone who likes to hike, bike, garden, run or do pretty much any physical activity, you’re likely quite familiar with getting blisters.

These fluid-filled skin bubbles can hypothetically form anywhere on your body but tend to form in places with a thick stratum corneum (the outermost layer of your skin) like the palms of the hands or soles of the feet. They are the result of an object (like a boot or a shovel handle) applying a force on our outer layer of skin, causing it to shear or split from the inner layers.

The space created by this skin split is then filled with fluid due to hydrostatic pressure. The fluid is usually clear and similar to blood plasma (although contains less protein) but if the skin split goes through several layers, the blister can fill with blood instead.

Moist skin is more likely to generate blisters than wet or dry skin, thanks to the forces of friction. When skin is wet, the water can act as a lubricating agent between an object and your skin. Similarly, when skin is dry, repeated rubbing against dry skin causes exfoliation and the buildup of a thin layer of dead skin cells that serve as a lubricant. But when skin is moist the dead cells are stuck to the skin and are unable to act as lubricants.

What should you do when you get a blister? Ideally, nothing. Blisters take roughly 7-10 days to heal and usually leave no scar. However, they can become infected if exposed to bacteria. If you don’t pop a blister, it remains a sterile environment, virtually eliminating any risks of infection.

But, if a blister is somewhere it cannot avoid being popped, or if it’s painful, draining it (carefully!) is an option. Preferably, have a medical expert drain it for you, but either way, make sure not to tear off the top of the blister! It serves as a biologic dressing over the wound and helps to keep it bacteria-free.

Whether you pop it or not, you can cover your blisters with a bandage to help cushion it, but topical antibiotics aren’t necessary. You could, however, always try an unconventional approach like covering your blisters with cyanoacrylate, or super glue! At least one study has found it more effective at reducing pain from blisters in soldiers and praised its ability to stay on for many days at a time

Is hard water dangerous to drink?

3 minute read
Originally posted here:

What is Hard Water?

Hard water is water containing high concentrations of dissolved minerals, usually calcium or magnesium carbonates (CaCO­or MgCO3), chlorides (CaCl2or MgCl2) or sulphates (CaSO4or MgSO4). The hardness of water depends on its source. Groundwater that has been in contact with porous rocks containing deposits of minerals like limestone or dolomite will be very hard, while water from glaciers or flowing through igneous rocks is much softer.

The hardness of water is determined by the milligrams of calcium carbonateper litre and is reported it in parts-per-million (ppm). In general, water with less than 60 ppm can be considered soft, water with 60-120 ppm moderately hard, and water with greater than 120 ppm hard. For reference, Montreal’s water is typically around 116 ppm, or moderately hard, and sea water’s hardness is approximately 6,630 ppm since it contains many dissolved salts (depending on the sea, of course).

Hard water can interfere with the action of soaps and detergents and can result in deposits of calcium carbonate, calcium sulphate and magnesium hydroxide (Mg(OH)2) inside pipes and boilers, causing lower water flows and making for less efficient heating. The ions in hard water can also corrode metal pipes through galvanic corrosion. Water softening filters can circumvent these problems through the use of ion-exchange resins that replace calcium and magnesium ions with sodium and potassium ions. But if one consumes water with higher-than-average concentrations of calcium and magnesium. Is that OK?

The Health Effects of Hard Water

Studies have generally found hard water to have positive effects on the health of its drinkers. Several studies have reported that calcium and magnesium in drinking water have a dose-dependent protective effect when it comes to cardiovascular disease. There is also some evidence that calcium and magnesium in drinking water may help protect against gastric, colon, rectal cancer, and pancreatic cancer, and that magnesium may help protect against esophageal and ovarian cancer. Hard water may also serve a protective role against atherosclerosis in children and teens.

Some studies have shown a relationship between the mineral content of water and eczema or dermatitis in children. However, a 2011 study from the University of Nottingham involving 336 children aged 6 months to 16 years with eczema put that relationship to the test. The researchers installed water softening units in half of the participants’ homes and monitored the children’s eczema over a period of 3 months. Using a standard scoring system, the group that received softened water showed a 20% improvement, while the group that continued with hard water showed a 22% improvement, making it unlikely that hard water is contributing to worsening eczema symptoms.

Likewise, while some studies have shown correlations between water hardness and kidney stone formation, the majority of studies have found no such relationship.

It is estimated that individuals living in hard water areas who drink 2 litres of water a day ingest about 52 mg of magnesium from their water. Considering the daily recommended intake of magnesium is 420 mg, water can account for about 12% of that.

Individuals with type 2 diabetes often experience hypomagnesemia (low magnesium) as insulin regulation requires magnesium to function. In these people, the extra intake of magnesium through drinking water could be beneficial. The heightened magnesium concentration in hard water can also benefit people experiencing chronic constipation, as magnesium salts act as laxatives. One study noted that vegetables cooked in hard water often show an increase in their calcium concentration, as opposed to the decrease seen when they’re cooked in soft water.

It is fairly difficult for humans with healthy kidneys to experience hypercalcemia (too much calcium), as any excess calcium is excreted through the kidneys. Similarly, hypermagnesemia is fairly rare, and usually just results in short episodes of diarrhea.

The Physical Effects of Hard Water

There are, however, some non-medical reasons hard water isn’t always preferable. Hard water can appear cloudy if the solubility of mineral salts is exceeded. Furthermore, if the calcium concentration surpasses 100 ppm, the water will taste “funny.” Neither of these presents a risk, but consumers prefer a “clean” appearance and taste.

Basically, while hard water can be hard on appliances and pipes, it is not hard on the body, and can actually give the daily intake of calcium and magnesium a nice little boost.

How Do You Like Your Salmon?

4 minute read
Originally posted here:

If you’re not particularly salmon savvy you may be under the impression that “salmon” is an individual species of fish, like how a black bear is an individual species of bear. That, however, is not true of our fishy friends. In fact, there are two main divisions of salmon: Atlantic and Pacific.

Atlantic salmon are big fish found in the northern Atlantic Ocean weighing 8-12 pounds when fully grown. Their meat is known to taste very mild and is generally cheaper than other types of salmon, due to the fact that nearly all of the Atlantic salmon commercially available today is farmed.

Climate change, human colonization, habitat destruction, and overfishing have decimated the wild populations of Atlantic salmon that were once abundant throughout the northern Atlantic. Lake Ontario was once home to this fish, but by 1900 the population was completely extinct. While there are still wild Atlantic Salmon alive and swimming, their capture is strictly regulated, hence the need for fish farms to fill this void.

What about Pacific salmon? Well, its name is a misnomer, since there isn’t one species of fish called Pacific salmon, but rather seven different species of salmon who live in the pacific: Sockeye, Chinook, masu (found mainly near East Asia), pink, Coho and Chum. While the Pacific salmons have suffered population losses due to humans and climate change, their numbers haven’t been decimated to the extent of the Atlantic salmon, so, wild-caught Pacific salmons are still commercially available.

Chinook (also called King) salmon are the largest of the Pacific salmons, weighing between 20 and 135 pounds. They’re known for being fatty, making them of value to chefs, and also quite pricey, due to their general rarity amongst fish. If you’re after something a little cheaper but still fat-filled, the Coho might be for you. At roughly 20 pounds in size, it is often cooked whole. Your low-fat salmon options include the lesser-known Chum or pink salmons, both quite small and low in fat, as well as the well-known, medium-sized, and bright pink Sockeye.

Whichever type of salmon you choose to eat though, you’ll want to find out where it was caught and whether it was farm-raised or wild-caught. Not for culinary purposes, since at least one study found that farmed salmon was as acceptable to eaters as wild salmon, but rather for health ones.

Quite a few studies have examined the levels of contaminants like PCBs (polychlorinated biphenyls), PBDEs (polybrominated diphenylethers), PAHs (polycyclic aromatic hydrocarbons) and mercury, and the results have not been confidence inspiring.

2001 study found that farmed salmon showed higher levels of PCBs, PBDEs, DLCs (dioxin-like compounds) and other chlorine-containing pesticides that pose significant health risks to humans. Similarly, a 2004 study found high levels of organochlorine contaminants in farmed fish and found that farmed salmon originating in Europe had much higher contaminant concentrations than salmon originating in North America or Chile.

The contaminants seem to get into the salmon through their food. Commercially available salmon feeds are extremely high in contaminants like PCBs and PBDEs, likely due to being made from small fish who themselves harbour high concentrations of contamination.

Interestingly enough, mercury, the contaminant we are used to hearing about in fish, is not an issue for either wild or farmed salmon. One study found that there’s less mercury in B.C. raised salmon than other foods like eggs, honey or vegetables.

Several studies have found that as few as one meal per month of farmed Atlantic salmon can expose the eater to contaminant levels that exceed those set by governing bodies like the World Health Organization. To reach a similar level of contamination by eating wild-caught salmon alone would take more than 4-16 meals per month. You can see a representative chart of this data (based on the United States Environmental Protections Agency’s guidelines) below.


Fish farms can also have devastating environmental consequences due to antibiotic use, waste accumulation, disease spread, escaped fish and more. These effects are bad not only for the surrounding oceans but for the fish too. Infections like sea lice can cause fish extreme pain or even kill them, and the genetic disorders common in farmed fish like curved spines or malformed jaws can severely harm their welfare.

So, what does this all mean for those who feed on fish?

You should keep in mind the potential risks of eating farm-raised salmon while grocery shopping and remember that you can minimize your exposure to these contaminants by choosing salmon that is either wild-caught or farm-raised in North America whenever possible.

If you’re eating salmon mainly for the omega-3 fatty acids, I have some good news and some bad news. The good news is that there are several non-meat sources of omega-3s, such as flax, chia, and hemp seeds, flaxseed oil, and eggs. The bad news is that many of the supposed health benefits of omega-3s have been largely overblown. Our own Dr. Christopher Labos has writtenabout omega-3’s ineffectiveness in preventing cardiovascular events and quite a few Cochrane reviews have found no benefits from fish oil for many conditions including ulcerative colitisasthmaCrohn’s diseaseallergies in children and dementia.

There’s a Condition That Can Cause Human Blood to Turn Green

1 minute read
Originally posted here

If you have clear blood you may be a brachiopod, if you have blue blood you may be an octopus (or just a rich human), but if you have green blood you may have sulfhemoglobinemia.

This interesting phenomenon occurs when a hemoglobin molecule (the molecule that allows our red blood cells to transport oxygen around our bodies) incorporates a sulphur atom into its structure and becomes sulfhemoglobin. Hemoglobin contains an atom of iron to bind to oxygen. In sulfhemoglobin, the sulphur atom prevents the iron from binding to oxygen, and since it’s the oxygen-iron bonds that make our blood appear red, with sulfhemoglobin blood appears dark blue, green or black.

Patients with sulfhemoglobinemia exhibit cyanosis, or a blueish tinge to their skin. This is caused by the tissues on the periphery of their bodies, like the fingertips, not receiving enough oxygen (since sulfhaemoglobin can’t transport oxygen like hemoglobin can).

Sulfhemoglobinemia is caused by excessive exposure to sulphur-containing compounds, like medications that contain sulfonamides (such as sumatriptanor furosemide), nitrate fertilizer, or the overconsumption of nitrogenous vegetables like spinach (usually only in infants). Rest assured that it takes huge amounts of these compounds to cause sulfhemoglobinemia, so you aren’t risking anything by taking your prescribed medications.

The treatment for sulfhemoglobinemia is a simple one: just wait it out. Red blood cells have a natural lifespan of about 100 days, after which they’re broken down and their components recycled. So, after about 3 months, any red blood cells that contain sulfhemoglobin will have been recycled into proper red blood cells, and any non-red tint to the blood will have disappeared.

Should I Attach a Bell to My Cat’s Collar?

3 minute read
Reposted with the permission of Animal Wellness Magazine. See the original here!

Consider these pros and cons before attaching a bell to your cat’s collar.

Does your cat bring you dead animals? While this common behaviour is kind of yucky, it’s also sort of endearing – your cat is bringing you what she believes to be an excellent gift. But despite their generous intentions, hunting by domestic cats is affecting ecosystems and pushing some species to extinction. So what can you do to keep your cat from catching wildlife? There are two primary solutions to consider: keep her inside, or attach a deterrent (such as a bell) to her collar.

A closer look at the options

Of course, the easiest method of preventing your cat from killing birds and rodents is to keep her inside all the time. In the safety of your home, your feline’s exposure to prey animals will be limited to any mice that happen to get into your house. If you aren’t willing to curb your feline’s wanderlust, a common alternative is to attach a bell to her collar to alert wildlife of her approach. But is this a safe and effective option?

The pros and cons of bells

number of studies have looked at whether or not bells help prey escape from cats, and the general consensus is yes! Bells on collars seem to reduce the amount of prey caught by about half, which could be enough to no longer pose a threat to ecosystems.

Effectiveness aside, many pet parents worry that a bell will hurt their cat’s ears. According to Veterinary PhD student Rachel Malakani, a collar bell will produce sound at about 50-60 dB, but studies have shown cats to be unaffected by sounds under 80 dB. While some cats with anxiety may not react well to the bell’s sound, it’s likely that the majority of cats simply won’t care.

Some owners worry that as well as alerting prey, a bell would also alert large predators to a cat’s presence. While this is possible, given most predator’s acute hearing, it’s unlikely that the relatively quiet noise of a bell would make the difference between your cat getting detected or not. If you live in an area where your cat is at risk of being attacked by large animals you should probably be keeping your cat indoors anyway, or at least supervise their outdoor activities. You can also invest in a cat enclosure, which will allow your feline to enjoy the fresh air safely!

Bell Alternatives

If you’re unwilling to put a bell on your furry buddy, you do have another option – cat bibs. Sold under names like Birdsbesafe, these devices are brightly colored to alert potential prey to the cat’s presence before they can pounce. While your cat might look a bit silly wearing a rainbow bib, the scientific research on these products shows they reduce predation rates by roughly the same amount as bells. That said, the devices that rely on color to alert potential prey work much better on birds (who have very good color vision) than they do on small mammals (who generally have quite poor vision).

If you’re scared of attaching any collars or collar-mounted devices to your felines – you shouldn’t be. While fears that cats can become strangled or trapped by a collar caught on debris are common, actual adverse effects from collars are rare. One study looked at 107 veterinarian practices and found only one collar-related injury per every 2.3 years, with collar-related deaths being even rarer. You can mitigate your fears further by using a breakaway collar.

If your cat ventures outdoors, especially if you live in an area with endangered species, please do your part to aid conservation efforts by outfitting your kitty with an anti-hunting device.