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Archive for March 18th, 2021

A Newfound Source of Cellular Order in the Chemistry of Life

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Viviane Callier has an interesting article in Quanta, and the GIF at the link that illustrates the article is quite striking. She writes:

Imagine packing all the people in the world into the Great Salt Lake in Utah — all of us jammed shoulder to shoulder, yet also charging past one another at insanely high speeds. That gives you some idea of how densely crowded the 5 billion proteins in a typical cell are, said Anthony Hyman, a British cell biologist and a director of the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden.

Somehow in that bustling cytoplasm, enzymes need to find their substrates, and signaling molecules need to find their receptors, so the cell can carry out the work of growing, dividing and surviving. If cells were sloshing bags of evenly mixed cytoplasm, that would be difficult to achieve. But they are not. Membrane-bounded organelles help to organize some of the contents, usefully compartmentalizing sets of materials and providing surfaces that enable important processes, such as the production of ATP, the biochemical fuel of cells. But, as scientists are still only beginning to appreciate, they are only one source of order.

Recent experiments reveal that some proteins spontaneously gather into transient assemblies called condensates, in response to molecular forces that precisely balance transitions between the formation and dissolution of droplets inside the cell. Condensates, sometimes referred to as membraneless organelles, can sequester specific proteins from the rest of the cytoplasm, preventing unwanted biochemical reactions and greatly increasing the efficiency of useful ones. These discoveries are changing our fundamental understanding of how cells work.

For instance, condensates may explain the speed of many cellular processes. “The key thing about a condensate — it’s not like a factory; it’s more like a flash mob. You turn on the radio, and everyone comes together, and then you turn it off and everyone disappears,” Hyman said.

As such, the mechanism is “exquisitely regulatable,” said Gary Karpen, a cell biologist at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory. “You can form these things and dissolve them quite readily by just changing concentrations of molecules” or chemically modifying the proteins. This precision provides leverage for control over a host of other phenomena, including gene expression.

The first hint of this mechanism arrived in the summer of 2008, when Hyman and his then-postdoctoral fellow Cliff Brangwynne (now a Howard Hughes Medical Institute investigator at Princeton University) were teaching at the famed Marine Biological Laboratory physiology course and studying the embryonic development of C. elegans roundworms. When they and their students observed that aggregates of RNA in the fertilized worm egg formed droplets that could split away or fuse with each other, Hyman and Brangwynne hypothesized that these “P granules” formed through phase separation in the cytoplasm, just like oil droplets in a vinaigrette.

That proposal, published in 2009 in Science, didn’t get much attention at the time. But more papers on phase separation in cells trickled out around 2012, including a key experiment in Michael Rosen’s lab at the University of Texas Southwestern Medical Center in Dallas, which showed that cell signaling proteins can also exhibit this phase separation behavior. By 2015, the stream of papers had turned into a torrent, and since then there’s been a veritable flood of research on biomolecular condensates, these liquid-like cell compartments with both elastic and viscous properties. . .

Continue reading. There’s much more.

Written by LeisureGuy

18 March 2021 at 7:09 pm

Posted in Evolution, Science

To quell misinformation, use rewards as well as punishments

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Tali Sharot writes in Nature:

In 2020 alone, social-media shares, likes and similar interactions with misleading online news doubled to 17% of all engagements. This staggering growth has consequences: polarization, violent extremism, racism and resistance to climate action and vaccines. Social-media companies have taken some steps to combat misinformation by using warnings and ‘sticks’, such as removing a few virulent spreaders of falsities and flagging misleading content. Facebook and Instagram users can report concerning posts, and Twitter prompts users to read articles before retweeting them.

How social-media companies should revamp their recommendation algorithms to quell misinformation is being discussed, but something is missing from the conversation: how to improve what users want to post and spread. Right now, users lack clear, quick incentives for reliability. Social-media platforms need to offer ‘carrots’ for truth.

As a neuroscientist who studies motivation and decision making, I have seen how even trivial rewards strongly influence behaviour. Most readers have felt an ego boost when their post received ‘likes’. Such engagement also results in followers, which can help people secure lucrative deals.

Thus, if a certain type of content generates high engagement, people will post more content like it. Here is the conundrum: fake news generates more retweets and likes than do reliable posts, spreading 6–20 times faster. This is largely because such content captures attention and confirms existing beliefs. What’s more, people share information even when they do not trust it. In one experiment (G. Pennycook et al. Nature https://doi.org/10.1038/s41586-021-03344-2; 2021), 40% of users who were shown fake news articles congruent with their political affiliation would consider sharing them, even though only 20% thought they were accurate.

At the moment, users are rewarded when their post appeals to the masses — even if it’s of poor quality. What would happen if users were rewarded for reliability and accuracy? A system that explicitly provides visible rewards for reliability has never, to my knowledge, been introduced by any major social-media platform. Such a system would work with the natural human tendency to select actions that lead to the greatest reward. It could thus both reinforce user behaviour that generates trustworthy material and signal to others that the post is dependable.

Reward systems have been successfully implemented before. In Sweden, drivers were offered prizes for obeying the speed limit, and average speed was reduced by 22%. In South Africa, a health-insurance company offered clients points whenever they purchased fruits and vegetables in the supermarket, visited the gym or attended a medical screening. Points could be exchanged for items, and were made visible to participants and their social circles. Participants’ behaviour changed enough to reduce hospital visits.

A challenge to implementing such a system on social media is how to

Continue reading.

Written by LeisureGuy

18 March 2021 at 5:01 pm

School-lunch decision triggers bedlam in France, including intemperate remarks

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Roger Cohen writes in the NY Times:

Grégory Doucet, the mild-mannered Green party mayor of Lyon, hardly seems a revolutionary. But he has upended France by announcing last month that elementary school lunch menus for 29,000 Lyonnais children would no longer include meat.

An outrage! An ecological diktat that could signal the end of French gastronomy, even French culture! Ministers in President Emmanuel Macron’s government clashed. If Lyon, the city of beef snouts and pigs’ ears, of saucisson and kidneys, could do such a thing, the apocalypse was surely imminent.

“The reaction has been quite astonishing,” Mr. Doucet, 47, said.

He is a slight man whose mischievous mien and goatee give him the air of one of Dumas’s three musketeers. A political neophyte elected last year, he clearly finds it a little ludicrous that he, an apostle of less, should end up with more, sitting beneath a 25-foot ceiling in a cavernous mayor’s office adorned with brocade and busts of his forbears. That tweaking a local school menu has split the nation leaves him incredulous.

“My decision was purely pragmatic,” he insisted, eyes twinkling — a means to speed up lunches in socially distanced times by offering a single menu rather than the traditional choice of two dishes.

Not so, thundered Gérald Darmanin, the interior minister. He tweeted that dropping meat was an “unacceptable insult to French farmers and butchers” that betrays “an elitist and moralist” attitude. Julien Denormandie, the agriculture minister, called the mayor’s embrace of the meatless lunch “shameful from a social point of view” and “aberrational from a nutritional point of view.”

All of which prompted Barbara Pompili, the minister of ecological transition, to speak of the “prehistoric” views, full of “hackneyed clichés,” of these men, in effect calling two of her cabinet colleagues Neanderthals.

This heated exchange over little illustrated several things. Mr. Macron’s government and party, La République en Marche, remain an uneasy marriage of right and left. The rising popularity of the Greens, who run not only Lyon but also Bordeaux and Grenoble, has sharpened a cultural clash between urban environmental crusaders and the defenders of French tradition in the countryside.

Not least, nothing gets the French quite as dyspeptic as disagreement over food.

The mayor, it must be said, made his move in a city with an intense gastronomic tradition. At the Boucherie François on the banks of the Rhône, a centennial establishment, Lyon’s culture of meat is on ample display. The veal liver and kidneys glistened; cuts of roast beef wrapped in pork fat abounded; the heads of yellow and white chickens lolled on a counter; the saucissons, some with pistachio, took every cylindrical form; the pastry-wrapped pâté showed off a core of foie gras; and pigs’ trotters and ears betrayed this city’s carnivorous inclinations.

“The mayor made a mistake,” said François Teixeira, a butcher who has worked at François for 19 years. “This is not good for Lyon’s image.”

Certainly, the mayor’s decision came at a sensitive moment. The right in France has expressed indignation that the country is being force-marched, through politically correct environmental dogmatism, toward a future of bicycles, electric cars, veganism, locavores, negative planet-saving growth and general joylessness — something at a very far cry from stuffing goose livers for personal delectation.

Last year, Pierre Hurmic, the Green party mayor of Bordeaux, touched a nerve when he rejected the city’s traditional Christmas tree because it’s “a dead tree.” Mr. Doucet’s culinary move was part of “an ideological agenda,” the right-wing weekly Valeurs Actuelles proclaimed in a cover story. “The canteens of Lyon were just a pretext.”

Mr. Doucet, who describes himself as a “flexitarian,” or someone who favors vegetables but also eats a little meat, argues that the Education Ministry forced his hand. By doubling social distancing at schools to two meters, or more than six feet, it obliged the mayor to accelerate lunch by offering just one dish.

“There’s a mathematical equation,” he said. “You have the same number of tables, but you have to put fewer children at them, and you can’t start the lunch break at 10 a.m.”

But why nix meat? The mayor, who has a 7-year-old in elementary school, rolled his eyes. “We have not gone to a vegetarian menu! Every day, the children can eat fish or eggs.” Because a significant number of students already did not eat meat, he said, “we just took the lowest common denominator.”

It was not, Mr. Doucet said, an ideological decision, even if he aims over his six-year term to adjust school menus toward “a greater share of vegetable proteins.” . . .

Continue reading.

Written by LeisureGuy

18 March 2021 at 4:47 pm

A modest step forward: George Schulz forces Andrei Gromyko to discuss the Soviet shooting down of a Korean civilian airliner — Notes of the meeting)

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It’s not often that one can read the actual notes from a diplomatic encounter. From the Office of the (US) Historian:

105. Memorandum of Conversation1

PARTICIPANTS

• U.S.—Secretary Shultz
• Assistant Secretary Richard Burt
Ambassador Arthur Hartman
Ambassador Jack F. Matlock
Mr. William D. Krimer, Interpreter
USSR—Foreign Minister A.A. Gromyko
Deputy Foreign Minister Komplektov
• Ambassador Makarov
• Mr. Viktor Sukhokrev, Interpreter

[Page 363]

The Secretary thought it would be fair to say that when he and Foreign Minister Gromyko agreed to hold this meeting several weeks ago, he had hoped that this meeting might make a modest step forward in the relationship between our two countries. Instead, the destruction of a civilian airliner carrying 269 people by a Soviet military aircraft has created a major new obstacle to progress.

Gromyko interrupted at this point, threw his glasses on the table, stood up and said he refused to discuss this matter as he had told the Secretary earlier.2

The Secretary interrupted and said he strongly insisted on such a discussion, that he had instructions to discuss this matter with Gromyko in order to draw his attention to how deeply this action had shocked all Americans. We were shocked by the cost in human life.

Gromyko interrupted again to say that he knew this without the Secretary telling it to him. He proposed that they first discuss an agenda on what issues were to be taken up at today’s meeting.

The Secretary said that he would take up the Korean airliner shoot-down right now. If Gromyko did not want to listen, that was his privilege.

Gromyko said he proposed that they discuss the major, important questions of curbing the nuclear arms race, and did not agree to start off on another issue.

The Secretary said that we must start with the question of the Korean airliner since it was on everyone’s mind as Gromyko surely heard in the conference room during the last two days. We must know the facts and how the Soviets plan to deal with them.

Gromyko said he knew this without the Secretary telling him, only he knew the facts of the matter better than anyone, i.e., he knew the truth.

[Page 364]

The Secretary repeated that his agenda called for first discussing the question of the Korean airliner tragedy.

Gromyko repeated that he wanted to talk about nuclear arms first; later he would be ready to discuss the question of the airliner.

The Secretary said that the airliner matter was of first importance and this was the subject he proposed to discuss with GromykoGromyko need not listen if he did not choose to, but he himself intended to explain his concerns.

Gromyko said he was reaching the conclusion that the Secretary did not want to discuss any other problem. In that case they had nothing to discuss at this meeting. The Secretary was in the clutches of an artificially built scheme.3

The Secretary interjected that if Gromyko did not want a meeting, so be it, and rose from his seat. He was disappointed that Gromyko did not want to hear our position. He pointed out that the other matters Gromyko had mentioned were the subject of discussions in Geneva and elsewhere but here, today, and under these circumstances, he had to address the problem that was foremost not only in his mind but also foremost in the views of most people throughout the world. Many Foreign Ministers had raised the question of the meeting here; airline pilots are very concerned; so are publics everywhere.

Gromyko said that the Secretary had already said a great deal on this question. He could report to the United States that he had only one matter to discuss, but Gromyko would report to his Government and to the whole world that the US side refused to discuss matters of such enormous importance as curbing the nuclear arms race and preventing the outbreak of nuclear war, and that he himself was prepared to discuss nuclear weapons. He added that he was entirely prepared to discuss other matters as well, including the Korean airliner matter. But priorities had to be agreed upon first and he would note that this was the first time that he found himself in a situation where the Secretary of State of the United States was attempting to impose an agenda for a meeting without taking into account the views of the other side.

The Secretary said that if Gromyko did not want to discuss this question with him, that would be his choice. But the Secretary’s choice [Page 365]was to convey to Gromyko the information he had regarding this matter.

Pacing and greatly agitated, Gromyko said,  . . .

Continue reading. There’s much more.

Written by LeisureGuy

18 March 2021 at 4:22 pm

Why Extraterrestrial Life May Not Seem Entirely Alien

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Don Falk interviews Arik Kershenbaum in Quanta:

On the website for the department of zoology of the University of Cambridge, the page for Arik Kershenbaum lists his three main areas of research, one of which stands out from the others. Kershenbaum studies “Wolves & other canids,” “Dolphins & cetaceans” — and “Aliens.” Granted, science hasn’t yet found any aliens to study, but Kershenbaum says that there are certain things we can still say about them with reasonable certainty. Topping the list: They evolved.

“The bottom line — why animals do the things that they do, why they are the things that they are — is because of evolution,” said Kershenbaum, a lecturer and director of studies in the natural sciences at the university’s Girton College. He argues that evolution is a universal law of nature, like gravity — and that studies of plants and animals here can therefore tell us something useful about potential inhabitants of worlds far beyond Earth. He finds evidence for this in the process of evolutionary convergence, in which unrelated lineages of organisms evolve similar features as adaptations to similar environmental challenges. It’s an argument he presents in detail in his new book, The Zoologist’s Guide to the Galaxy: What Animals on Earth Reveal About Aliens — and Ourselves, which draws on comparisons of animals’ physical adaptations as well as his own research (and that of others) into animal communications.

Quanta recently spoke with Kershenbaum at his home in Cambridge via videoconference. The interview has been condensed and edited for clarity.

You’re a zoologist; you study life here on our own planet. What made you want to write a book about alien life?

When zoologists study life on Earth, we’re studying mechanisms. We’re studying how life became the way it is. And because evolution is the explanatory mechanism for life everywhere, then the principles that we uncover on Earth should be applicable in the rest of the universe. Thinking about how life on other planets evolves and behaves is just a natural extension of my work with animals on Earth. If we discovered a lost island on this planet, we’d be examining its animals from the perspective of what we know about the evolution of life in general. You can be sure that if we discovered alien life on another planet, we’d be using the same methods to ask why they look and behave the way they do, and how they evolved.

You argue that natural selection — the key mechanism behind evolution — is inevitable, and that it applies universally. What makes you so confident about that?

No planet will have a complex form of life that popped into existence all on its own. Whatever life is like on an alien planet, it must have begun simply. Now, it could be that it remained simple; that’s possible. Probable, even, on many planets. But if life is to achieve any kind of complexity, the only way that complexity can accumulate is if favorable changes and innovations are retained and unfavorable ones are lost — and that’s precisely evolution by natural selection.

One of the key ideas in your book is the notion of “convergent evolution.” What is that, and why is it important?

If you observe two animals with similar features — feathers, for instance — you might presume that they inherited them from a common ancestor: the feathered dinosaur that was the ancestor of all modern birds. That’s just regular evolution, where children have similarities because they inherit the characteristics of their parents.

But sometimes you see animals with traits that they couldn’t possibly have inherited from a common ancestor. For instance, the wings of birds work in pretty much the same way as the wings of bats. But the common ancestor of birds and bats was a small lizardlike creature that lived over 300 million years ago, long before even the dinosaurs. It certainly didn’t have wings, and the large majority of its descendants, including elephants and crocodiles, don’t have wings (thankfully). So those wings must have evolved separately in different lines of descendants.

Sometimes this “convergence” of traits is for something obviously useful, like wings. But sometimes convergence produces bizarrely similar creatures that share so many characteristics, it can be hard to believe they’re not closely related. The recently extinct thylacine [a large predatory marsupial native to Tasmania and mainland Australia], for example, could easily be mistaken for a peculiar breed of dog, but it’s much more closely related to a kangaroo! And yet living a life similar to that of modern coyotes or jackals meant that it evolved many similar characteristics convergently.

You’re arguing that wherever organisms confront similar environmental challenges, they may come up with similar adaptive solutions. And you expect to see this throughout the universe?

Consider flight, since that’s the most famous example of convergence. If you live on a planet with an atmosphere, or even with an ocean or some other fluid, if you want to get from one place to another through that fluid, there’s only a handful of ways to do it. You can . . .

Continue reading. There’s much more.

I have great difficulty understand the reasoning of those who dispute the fact of evolution.

Written by LeisureGuy

18 March 2021 at 4:07 pm

Don’t Discount Evangelicalism as a Factor in Racist Murder of Asian Spa Workers in Georgia

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An article in Religion Dispatches is worth reading:

Today, America is still reeling from the news of the mass murder of eight people at massage parlors in Georgia. Many are rightly calling the shooting spree an act of white supremacist terrorism, as the victims targeted were Asian women. The moment I read that the man who confessed to the murders was the son of a youth pastor who told police he had a “sex addiction,” however, it struck me that we must not ignore the specifically evangelical Protestant contours of this story.

I want to be clear. As Joshua Grubbs, an assistant professor of psychology at Bowling Green State University who has published research on religion and attitudes toward sex told RD, “Sex addiction is simply not a credible defense for mass murder.” One of the most significant conclusions Grubbs’ research points to, however, is that conservative Christian men are prone to believe that they have pornography or sex “addictions,” even when they do not. Before he was apprehended by police, Robert Aaron Long was reportedly on his way to target the porn industry in Florida for violence similar to what he perpetrated in Georgia.

According to Grubbs, “There’s a large and growing body of research that shows that conservative religious values are strongly linked to feelings of sex addiction. We find that men in particular are likely to interpret normal sexual urges as pathological and then act on them in ways that they find to be problematic.” As Grubbs told me in a previous interview, while some people do exhibit compulsive and dysregulated behavior with respect to pornography, “There are also quite a number of people who report feeling out of control even with minimal use.”

If Long is telling the truth about his desire to “eliminate” the “temptations”—that is, women—that he claims exacerbated his “sex addiction,” it’s likely that he learned to think of himself this way, and to objectify women, in church. In evangelical institutional environments such as churches and Christian schools, discussions of sex are usually steeped in purity culture, that is a complex of beliefs and practices associated with an unhealthy fear of sexuality and intense pressure to remain “pure”—that is, sexually inexperienced—before marriage. I am among the many ex-evangelicals who were essentially coerced into signing “purity pledges” in the 1990s, which is just one of the many manipulative practices associated with purity culture.

According to Grubbs, “Purity culture places heavy emphasis on temptation and evil. Pornography is considered evil and something to be eliminated. Given that framing, it’s not surprising that someone might view all sexual ‘temptations’ as evil and needing to be eliminated.” Speaking of Long, Grubbs elaborated, “I would not call this person a ‘victim’ of purity culture, but it is possible that he is a product of it.”

The flip side of more secular rape culture, purity culture teaches boys that they are “lust monsters” and girls that it’s their duty to protect their purity by being “modest.” In evangelical culture, youth pastors are among the primary purveyors of these messages, and thus key figures in socializing white evangelical youth in evangelicalism’s version of toxic masculinity. As a result, victims of child sex abuse and of sexual assault in evangelical communities are often blamed for “tempting” the perpetrators, while the latter, particularly if they’re white men with an important role in the church, are protected from what should be the full consequences of their crimes. . .

Continue reading. There’s much more.

Written by LeisureGuy

18 March 2021 at 3:56 pm

Why pay more than $6 for a razor?

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I wrote recently about why people $200 for a shaving brush when a $10 synthetic does a good job, and the same question might be asked about razors. In my experience, razors differ from brushes by having a more distinct range of feel (in the hand and on the face) and performance and aethetics. Still, the razor I used today, the Baili BR171, is only $6, and for me it is outstanding in comfort, efficiency, feel in the hand, and aesthetics.

But before the razor is raised, prep is needed. This Rooney Victorian 2 is one of my price brushes, with a knot very like yesterday’s Emilion, and it coaxed a fine lather from The Dead Sea shaving soap — though TBH very little coaxing is required since this is a soap that loves to lather.

Three passes with Baili left my face totally smooth, and a small splash of Valley of Ashes aftershave from Southern Witchcraft finished the job.

It’s another sunny day, and today I call to schedule my Covid-19 vaccination.

Written by LeisureGuy

18 March 2021 at 10:30 am

Posted in Shaving

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