As of March 4, 2020 the novel coronavirus SARS-CoV-2, which causes COVID-19, has spread to more than 77 countries. More than 93,000 cases have been reported, and just under 3,200 deaths. It’s thought that the virus infected its first human victim in the city of Wuhan in China, in November, 2019. That case was apparently caused by transmission of SARS-CoV-2 from an animal. Since then, it has spread by human-to-human contact. The virus probably originated in bats, and then likely passed through another animal before it found its human host.… Read the rest “The Drift of Coronavirus”

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The environmental cost of beef production is well known: it generates a lot of greenhouse gases (GHG), compared to plant-derived foods or even meats such as pork or chicken. A major reason is that bovines’ stomachs use oxygen-free, “enteric” fermentation to digest grass, as described in a previous post. As a result, they burp up a lot of methane, which is a potent GHG.

The greenhouse gas contributions of methane, nitrous oxide, and fluorinated gases are encompassed by the term “CO2 equivalents” (CO2e).… Read the rest “Your steak and global warming”

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The agitated detective barks, “I need that DNA now. I have to know if we’ve got the killer in custody. I don’t give a damn how busy you are . . . ” We’ve all been there, on the edge of the couch, watching a cop show on TV and hoping that the magic of DNA testing will give a clear answer to the question “DidHeDoIt?” And indeed, DNA fingerprinting, more accurately ‘DNA profiling’, has transformed crimefighting.… Read the rest “The Unanticipated Birth of DNA profiling”

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Gel electrophoretic separation of DNA fragments containing Variable Numbers of Tandem Repeats. Each vertical lane contains one DNA sample. PCR-amplified fragments have been labeled, with different probes having different fluorescent labels. The red bands are internal calibration markers. The positions of the bands reflect their different mobilities, which in turn reflect their lengths (larger fragments move more slowly in electrophoresis). Capillary electrophoresis and automatic recording are used today instead of gel electrophoresis.

DNA profiling resulted from the convergence of scientific curiosity, technological advances, and the desire to provide a social benefit.… Read the rest “New and improving DNA profiling continues to impress and surprise”

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The material in this post has been upgraded and expanded in two posts, which describe human energy efficiency at rest and during vigorous exercise.

I first posted “The Inefficiency of Humans” in January 2017. It’s about the reasons that our energy metabolism provides only about 20-25% of the energy we consume as food for muscular work. I referred to this as our “inefficiency”, although it isn’t really that. The explanation and conclusions remain largely unchanged, but since then I’ve learned more about how energy metabolism is measured, so I’ve rewritten the post as this 2.0 version.… Read the rest “The Inefficiency of Humans”

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Laphroiag distillery on Islay. A group of international whisky tourists, an important source of revenue for malt distilleries in Scotland, is being shown around. The pagoda chimney is a common feature.

There is a good deal of science, and art, associated with single malt Scotch whisky (there’s no “e” in whisky in Scotland). Many of us know bits and pieces about it and how it’s made. But there may be readers, who, like me, are fans but also interested to learn more.… Read the rest “Single malt Scotch Whisky 101”

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A death in Minnesota

The young man arrived in the emergency room in Minneapolis, Minnesota in acute distress, with a fever, rapid deep breathing, and a racing heart. As reported in 2018, doctors couldn’t initially identify the cause of his problem (1). His breath had twice the normal level of carbon dioxide, and that level kept going up. His fever also kept increasing, despite the doctors’ frantic efforts to stabilize him. Forty-five minutes after admission the muscles in his body violently seized up, rigor mortis, but in a body not yet dead.… Read the rest “How DNP (dinitrophenol) kills you”

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Rooftop air conditioning units, midtown, Manhattan. Imagery Google Maps, ©2019 Bluesky, Maxar Technologies, Sanborn, USDA Farm Service Agency, Map data ©2019

A hot day in New York City

People who were there will remember Saturday, July 20, 2019, as a really hot day in New York City. Although it was not the hottest day on record, the temperature at Kennedy airport reached 96ºF (36ºC). On the street at Union Square in Manhattan, a large thermometer (known as BAT, the “Big-Ass Thermometer”) registered a murderous 110ºF.… Read the rest “Is Air Conditioning Going to Become Futile?”

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Early Press. Accreditation: Daniel Chodowiecki [Public domain]

This post is something original, in that it’s not original: it’s a link to an intriguing article published a few years ago, which came to my attention on Flipboard. The article was published in 2013 in The Atlantic, and was a compilation of the 50 “innovations that have done the most to shape the nature of modern life”(since the wheel). I sent emails which included an abridged version of the article to a number of people.… Read the rest “The Greatest Innovations and Breakthroughs ever”

The Ponte Morandi before collapse View More

Ponte Morandi, Genoa. The tower on the left, and the adjacent roadway, collapsed on August 14, 2018. Picture attribution: Salvatore1991

A terrible tragedy occurred in Genoa, Italy on August 14, 2018. A suspension bridge in that city, part of the A10 motorway, collapsed into the bed of the Polcevera River, 150 feet below. Forty-three people who were driving over the bridge were killed.

The cable-stayed bridge

The bridge in Genoa, called the Ponte Morandi after its designer, Riccardo Morandi, was opened in 1967.… Read the rest “The Death of Ponte Morandi”