How whales lost their sense of smell and taste

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Whales are very likeable creatures. They are highly intelligent, sentient and social. But without a doubt, they would make terrible chefs and untrustworthy food critics. It seems that somewhere along the evolutionary path, whales lost their sense of smell and much of their sense of taste.

Baleen whales are some of the largest animals in the world and spend most of their time below the water surface, making them difficult to find and even more difficult to study. The group of Japanese researchers at Kyoto University worked around these challenges by using genome sequencing and fossil records to study the evolution of smell and taste in toothed and baleen whales. The researchers isolated DNA from minke whale meat purchased at a fish market and sequenced it to assemble the entire genome of the minke whale. For comparison, they also used the previously sequenced genomes of the bottlenose dolphin, a toothed whale, and cow, which, along with pigs and hippos, belongs to the same clade as cetaceans.

In mammals, odours in the air are detected by different receptors in our nasal cavity. When they compared the whale genomes to the cow genome, the researchers found that both whale genomes had lost a large number of genes required for odour detection. The most notable of these is the family of genes known as olfactory receptors (OR). The cow genome contained over 900 functional OR genes while the minke whale and dolphin genomes contained just 70 and 12, respectively. Mice, with their keen sense of smell, have over 1000 OR genes. Continue reading

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The lesser of two evils: e-cigarette exposure weakens anti-bacterial and anti-viral defenses

During cold and flu season, many of us try to boost our immune system to resist getting sick. But if you smoke, you are at a greater risk of acquiring an infection and becoming ill. Both cigarette smoke and nicotine are known to suppress the body’s immune system, which contribute to smokers being more susceptible to bacterial and viral infections. Patients with chronic obstructive pulmonary disease caused by smoking are especially prone to lung infections.

Electronic cigarettes, or e-cigarettes, are widely believed to be a healthier alternative to traditional cigarettes. While they undoubtedly cause less harm than traditional cigarettes, e-cigarettes are still hazardous to your health. A team of researchers led by Prof. Shyam Biswal at Johns Hopkins University has shown that exposure to e-cigarettes impairs your body’s ability to fight off bacterial and viral infections.

To study the effects of e-cigarette vapor on immune responses, the researchers developed the first mouse model for e-cigarette exposure. They used a modified cigarette smoke machine that regularly puffed e-cigarette vapor into a small chamber. Mice were exposed to e-cigarette vapor in the chamber for one and a half hours twice per day for two weeks. Continue reading

Between the Pages: Is Gwyneth Paltrow Wrong About Everything?

Timothy Caulfield seems like the type of person that you would want as your friend. Unless you are a colon cleansing, dream pursuing, celebrity adoring kind of person. Then he might come across as a bit of a “patronizing know-it-all jerk” (his words, not mine).

In his latest book Is Gwyneth Paltrow Wrong About Everything?, Caulfield looks at the messages spewed out by celebrity culture and how those messages stack up against scientific evidence. Spoiler alert: the answer to the book’s title question is an unequivocal yes.

Is Gwyneth Paltrow Wrong About Everything?: When Celebrity Culture and Science Clash. By Timothy Caulfield (Source)
Is Gwyneth Paltrow Wrong About Everything?: When Celebrity Culture and Science Clash. By Timothy Caulfield (Source)

The book starts by examining the vast array of health and beauty treatments inspired and endorsed by celebrities, including the Clean Cleanse made famous by Gwyneth Paltrow on her lifestyle website Goop. One of my favourite parts of the book is when Caulfield himself becomes a test subject and tries out the cleanses, spa treatments, and skin-care regimes that are supposed to make him healthier, slimmer and more beautiful. The results? He lost weight (but gained it back as soon as he started eating real food) and his skin was no better off after nine months of using high-end beauty products.  Continue reading