/oss/taxonomy/term/198/all en /oss/article/medical-general-science/studying-organic-chemistry-can-pay <p>One of the fundamental reactions we teach in organic chemistry is “nucleophilic substitution” in which an atom or group of atoms in a molecule is exchanged for another one. Quite logically, the substituted atom or group is known as a “leaving group.” The ease with which a leaving group can be displaced by the substituting species, or “nucleophile,” is variable and depends on several factors including the strength of the bond with which the leaving group is attached to the rest of the molecule.</p> Fri, 26 Jul 2024 14:51:32 +0000 Joe Schwarcz PhD 10010 at /oss /oss/article/technology-history-general-science/media-has-expiration-date <p>The tragedy occurred as I was rewatching the final season of <i>Six Feet Under</i>, arguably the best television series ever made.</p> <p>Each episode begins with a death, sometimes comical, sometimes deeply affecting. In this case, the entire episode died. The image started to freeze, displaying rectangular blocks of colour. The audio soon followed. The episode lived up to its name, “The Silence.”</p> Fri, 31 May 2024 16:00:00 +0000 Jonathan Jarry M.Sc. 9965 at /oss /oss/article/history-general-science/molecular-structure-dna-and-dream-staircase-wasnt <hr /> <p><em>This article was first published in the <a href="https://montrealgazette.com/opinion/columnists/the-right-chemistry-the-molecular-structure-of-dna-and-a-dream-staircase-that-wasnt">Montreal Gazette</a>.</em></p> Fri, 19 Jan 2024 21:19:06 +0000 Joe Schwarcz PhD 9811 at /oss /oss/article/medical/dna-trenches-how-identify-fallen-soldiers <p>Last week, we were told that DNA performed a bit of a miracle: it identified a man who was born in 1894 and who died during the First World War. His name was <a href="https://www.canada.ca/en/department-national-defence/news/2023/01/canadian-soldier-of-the-first-world-war-identified2.html">Percy Howarth</a>. He was born in Lancashire, England, and moved to Canada a few years before enlisting with the Canadian Expeditionary Force. In 1917, he fought at the Battle of Hill 70 near Lens, France, as part of the 7<sup>th</sup> Canadian Infantry Battalion.</p> Fri, 27 Jan 2023 03:59:07 +0000 Jonathan Jarry M.Sc. 9372 at /oss /oss/article/medical-history/edisons-inadvertant-folly <p>It all started in Bavaria, southern Germany, 1895. Dr. Roentgen, a physicist, noticed a spooky greenish ray seeping through the completely sealed test tube and projected onto the screen wall. What on earth! When he placed an object between the energy source and the wall, the ray powerfully shined through the object, casting a vivid silhouette on the wall. Magical! Excited but holding a certain degree of uncertainty as to the nature of the energy, Dr. Roentgen coined the electromagnetic wave “X” ray.</p> Fri, 09 Dec 2022 15:35:00 +0000 Nancy Liu-Sullivan, PhD 9318 at /oss /oss/article/general-science/mitochondria-story-mothers-teenagers-and-energy <p>Certain concepts simply irk me. They are often needlessly complicated and their meaning gets distorted in an attempt to make them understandable.</p> <p>Take, for example, the idea of a Mitochondrial Eve.</p> Fri, 30 Sep 2022 10:00:00 +0000 Jonathan Jarry M.Sc. 9245 at /oss /oss/article/medical-critical-thinking-health-and-nutrition/yummy-hype-nutrigenomics <p>Should you let your genes decide what you eat? The field of nutrigenomics certainly leans in that direction. Frustratingly, there are two sides to nutrigenomics. On the one hand, it is a research endeavour trying to shed light on the interactions between the food we eat and the molecules in our body. On the other hand, it is a commercial endeavour piggybacking on the public’s fascination with DNA and the personalization of care.</p> <p>Is it worth the hype?</p> Sat, 27 Aug 2022 22:20:50 +0000 Jonathan Jarry M.Sc. 9215 at /oss /oss/article/environment/when-drinking-tea-you-get-mouthful-bug-dna <p>There are bugs in your cup of tea. Not whole bugs (hopefully not). But the essence of a hundred species of insects can be found in that tea bag you buy from the store. Even if you have been sipping tea for decades, I don’t think you need to worry about turning into Jeff Goldblum from <i>The Fly</i>.</p> Fri, 08 Jul 2022 14:00:00 +0000 Jonathan Jarry M.Sc. 9167 at /oss /oss/article/medical-critical-thinking/how-nature-solved-problem-too-much-dna <p>When you consider how babies are made, you bump up against a basic math problem. No need for calculus here, or even the mental gymnastics of carrying the one. It’s a problem of doubling.</p> Thu, 16 Jun 2022 19:20:46 +0000 Jonathan Jarry M.Sc. 9139 at /oss /oss/article/critical-thinking/impossible-crime-unless-you-know-about-chimeras <p>It seemed like an impossibility. After all, DNA doesn’t lie.</p> <p>The setting is Alaska. A serious sexual assault has been committed and investigators are trying to find out who the perpetrator is. The evidence they have is sperm, which famously contains DNA.</p> <p>When the extracted DNA is compared to the criminal justice DNA database, a match is found to a blood sample that was taken from a known criminal. Case closed, right?</p> <p>Except that when the sexual assault took place, this known criminal was behind bars.</p> Thu, 26 May 2022 23:17:25 +0000 Jonathan Jarry M.Sc. 9123 at /oss /oss/article/health-and-nutrition/non-smokers-lung-cancer-and-hidden-link <p>The link between cigarette smoking and lung cancer is widely acknowledged. But not everyone who smokes gets lung cancer and not everyone who gets lung cancer is a smoker. How does one contract the so-called non-smoker’s lung cancer? The answer, one might say, is blowing in the wind. And that wind may be blowing a gas called radon.     </p> Fri, 31 Dec 2021 19:08:52 +0000 Nancy Liu-Sullivan, PhD 8970 at /oss /oss/article/history-general-science/word-cisgender-has-scientific-roots <p>In 2015, the Oxford English Dictionary<a href="https://public.oed.com/blog/december-2015-update-new-words-notes/"> </a><a href="https://public.oed.com/blog/december-2015-update-new-words-notes/">added the word “cisgender”</a> to its ever-evolving listing. It defines the adjective as “designating a person whose sense of personal identity and gender corresponds to his or her sex at birth” and is contrasted with “transgender.”</p> Fri, 12 Nov 2021 17:15:12 +0000 Jonathan Jarry M.Sc. 8920 at /oss /oss/article/covid-19-health-and-nutrition/antivirals-are-coming <p>I continue to be amazed by science. The ability to predict to the second when an eclipse will occur at a specific location in the world, the know-how to build a jetliner that requires the cohesive working of over four million parts and the production of computers with all their marvellous functions are astounding examples of human ingenuity. To say nothing about reaching into your pocket for the smartphone that in a fraction of a second will provide an answer to almost any question you may have. Mind-boggling.</p> Fri, 12 Nov 2021 21:02:21 +0000 Joe Schwarcz PhD 8921 at /oss /oss/article/covid-19-health/evidence-coronavirus-can-mess-our-dna-far-convincing <p>Science is hard. This is not meant to dissuade anyone from going into the sciences. It’s just a statement of fact with which all scientists would probably agree, and it’s a sort of mantra we can repeat to ourselves to recalibrate our expectations once in a while.</p> Fri, 14 May 2021 19:25:48 +0000 Jonathan Jarry M.Sc. 8733 at /oss /oss/article/covid-19-general-science/worlds-second-best-molecule-year <p>The COVID-19 pandemic has made visible so many unsung heroes. Essential workers, parents who must work from home and care for their children, healthcare personnel. But there is one hero whose positive impact on the pandemic remains unsung and for good reasons. It doesn’t technically qualify as a hero because it’s not even alive. It’s a molecule but not any molecule, mind you. The prestigious journal <i>Science </i>dedicated<a href="https://science.sciencemag.org/content/246/4937/1543.long"> its Christmas 1989 cover</a> to throwing flowers at it, calling it “the molecule of the year.”</p> Thu, 11 Feb 2021 19:29:57 +0000 Jonathan Jarry M.Sc. 8615 at /oss