We’re Sorry - Scientific American

Cats Are Perfect. An Evolutionary Biologist Explains Why | Scientific American
▻https://www.scientificamerican.com/article/cats-are-perfect-an-evolutionary-biologist-explains-why1

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Anjali Goswami thinks cats are perfect—not in the same way as the average cat person, out of admiration for their beauty, athleticism and independence of spirit, but from a scientific standpoint. Goswami is an evolutionary biologist at the Natural History Museum in London who studies large-scale patterns of evolution in vertebrate animals over time. She contends that cats—from tabbies to tigers—are quintessential products of evolution. Her explanation reveals cats, and the meaning of evolutionary success, in a fascinating new light.

ChatGPT Replicates Gender Bias in Recommendation Letters | Scientific American
▻https://www.scientificamerican.com/article/chatgpt-replicates-gender-bias-in-recommendation-letters

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Generative artificial intelligence has been touted as a valuable tool in the workplace. Estimates suggest it could increase productivity growth by 1.5 percent in the coming decade and boost global gross domestic product by 7 percent during the same period. But a new study advises that it should only be used with careful scrutiny—because its output discriminates against women.

The researchers asked two large language model (LLM) chatbots—ChatGPT and Alpaca, a model developed by Stanford University—to produce recommendation letters for hypothetical employees. In a paper shared on the preprint server arXiv.org, the authors analyzed how the LLMs used very different language to describe imaginary male and female workers.

“We observed significant gender biases in the recommendation letters,” says paper co-author Yixin Wan, a computer scientist at the University of California, Los Angeles. While ChatGPT deployed nouns such as “expert” and “integrity” for men, it was more likely to call women a “beauty” or “delight.” Alpaca had similar problems: men were “listeners” and “thinkers,” while women had “grace” and “beauty.” Adjectives proved similarly polarized. Men were “respectful,” “reputable” and “authentic,” according to ChatGPT, while women were “stunning,” “warm” and “emotional.” Neither OpenAI nor Stanford immediately responded to requests for comment from Scientific American.

The issues encountered when artificial intelligence is used in a professional context echo similar situations with previous generations of AI. In 2018 Reuters reported that Amazon had disbanded a team that had worked since 2014 to try and develop an AI-powered résumé review tool. The company scrapped this project after realizing that any mention of “women” in a document would cause the AI program to penalize that applicant. The discrimination arose because the system was trained on data from the company, which had, historically, employed mostly men.

The new study results are “not super surprising to me,” says Alex Hanna, director of research at the Distributed AI Research Institute, an independent research group analyzing the harms of AI. The training data used to develop LLMs are often biased because they’re based on humanity’s past written records—many of which have historically depicted men as active workers and women as passive objects. The situation is compounded by LLMs being trained on data from the Internet, where more men than women spend time: globally, 69 percent of men use the Internet, compared with 63 percent of women, according to the United Nations’ International Telecommunication Union.

Fixing the problem isn’t simple. “I don’t think it’s likely that you can really debias the data set,” Hanna says. “You need to acknowledge what these biases are and then have some kind of mechanism to capture that.” One option, Hanna suggests, is to train the model to de-emphasize biased outputs through an intervention called reinforcement learning. OpenAI has worked to rein in the biased tendencies of ChatGPT, Hanna says, but “one needs to know that these are going to be perennial problems.”

This all matters because women have already long faced inherent biases in business and the workplace. For instance, women often have to tiptoe around workplace communication because their words are judged more harshly than those of their male colleagues, according to a 2022 study. And of course, women earn 83 cents for every dollar a man makes. Generative AI platforms are “propagating those biases,” Wan says. So as this technology becomes more ubiquitous throughout the working world, there’s a chance that the problem will become even more firmly entrenched.

“I welcome research like this that is exploring how these systems operate and their risks and fallacies,” says Gem Dale, a lecturer in human resources at Liverpool John Moores University in England. “It is through this understanding we will learn the issues and then can start to tackle them.”

Dale says anyone thinking of using generative AI chatbots in the workplace should be wary of such problems. “If people use these systems without rigor—as in letters of recommendation in this research—we are just sending the issue back out into the world and perpetuating it,” she says. “It is an issue I would like to see the tech firms address in the LLMs. Whether they will or not will be interesting to find out.”
Rights & Permissions
Chris Stokel-Walker is a freelance journalist in Newcastle, UK.

#Intelligence_artificielle #discrimination #Lettres_de_recommandation #genre

How Bears Hibernate without Getting Blood Clots - Scientific American
▻https://www.scientificamerican.com/article/how-bears-hibernate-without-getting-blood-clots

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The biologists collected blood samples from 13 hibernating bears in their dens during the winter. In the summer the biologists collected additional blood from the same bears after shooting tranquilizer darts at them from a helicopter.

[…] The platelet protein with the largest disparity between active and hibernating bears was heat shock protein 47 (HSP47).

HSP47 recruits an enzyme called thrombin that helps platelets stick together and form clots. In active bears, HSP47 helps patch up cuts and stop bleeding. But hibernating bears, which are safely snug in their dens, have little use for this clotting protein. On average, hibernating bears’ platelets produced 55 times fewer HSP47 proteins than those of active bears.

“We hadn’t heard much about this protein, and we were completely surprised to discover that it has such a large impact,” says Manuela Thienel, the paper’s lead author, also at the German Center for Cardiovascular Research. Thienel says that decreasing the levels of this particular protein likely reduces the platelets’ penchant for clumping together and restricting blood flow.

[…]

To determine if a similar mechanism prevents blood clotting in chronically immobile humans, the researchers compared blood samples from patients who had suffered debilitating spinal injuries with samples from their active counterparts. Like that of hibernating bears, the blood of chronically immobile patients had fewer circulating HSP47 proteins. “Downregulation of HSP47 during hibernation of bears or chronically immobilized patients reduces thromboinflammation” and thus reduces the risk of blood clots, Schattner says.

#Thrombose

How Stochastic Terrorism Uses Disgust to Incite Violence - Scientific American
▻https://www.scientificamerican.com/article/how-stochastic-terrorism-uses-disgust-to-incite-violence

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Pour comprendre comment l’alt-right manipule le « dégoût » pour provoquer la peur. Dernier épisode en date le tweet de Melon Musk contre Fauci.

Some People Who Appear to Be in a #Coma May Actually Be Conscious - Scientific American
▻https://www.scientificamerican.com/article/some-people-who-appear-to-be-in-a-coma-may-actually-be-conscious

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As many as 15 to 20 percent of patients who appear to be in a coma or other unresponsive state show these inner signs of awareness when evaluated with advanced brain-imaging methods or sophisticated monitoring of electrical activity.

#dissociation_cognitivo-motrice en français

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▻https://neurologies.fr/troubles-de-la-conscience-et-coma

Vultures Prevent Tens of Millions of Metric Tons of Carbon Emissions Each Year - Scientific American
▻https://www.scientificamerican.com/article/vultures-prevent-tens-of-millions-of-metric-tons-of-carbon-emiss

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Decaying animal bodies release greenhouse gases, including carbon dioxide and methane. But most of these emissions can be prevented if vultures get to the remains first, a new study in Ecosystem Services shows. It calculates that an individual vulture eats between 0.2 and one kilogram (kg) of carcass per day, depending on the vulture species. Left uneaten, each kg of naturally decomposing carcass emits about 0.86 kg of CO2 equivalent. This estimate assumes that carcasses not eaten by vultures are left to decay. But many carcasses are composted or buried by humans, which result in more emissions than natural decay, so vulture consumption can avert even more emissions when replacing those methods. The avoided emissions may not sound like much, but multiply those estimates by the estimated 134 million to 140 million vultures around the world, and the number becomes more impressive: tens of millions of metric tons of emissions avoided per year.

#vautours

When Students Acquire Spatial Skills, Their Verbal Abilities Get a Boost - Scientific American
▻https://www.scientificamerican.com/article/when-students-acquire-spatial-skills-their-verbal-abilities-get-

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The findings offer a potential warning about what humans risk by dispensing with spatial learning experiences and relying instead on a smartphone navigator to get from point A to point B. Green recently lost a signal in a rural area while on a family vacation and found himself explaining paper maps and navigation methods to his children.

#espace #langage

Cache Cab: Taxi Drivers’ Brains Grow to Navigate London’s Streets - Scientific American
▻https://www.scientificamerican.com/article/london-taxi-memory

Memorizing 25,000 city streets balloons the hippocampus, but cabbies may pay a hidden fare in cognitive skills

By Ferris Jabr on December 8, 2011
Manhattan’s midtown streets are arranged in a user-friendly grid. In Paris 20 administrative districts, or arrondissements, form a clockwise spiral around the Seine. But London? A map of its streets looks more like a tangle of yarn that a preschooler glued to construction paper than a metropolis designed with architectural foresight. Yet London’s taxi drivers navigate the smoggy snarl with ease, instantaneously calculating the swiftest route between any two points.

These navigational demands stimulate brain development, concludes a study five years in the making. With the new research, scientists can definitively say that London taxi drivers not only have larger-than-average memory centers in their brains, but also that their intensive training is responsible for the growth. Excelling at one form of memory, however, may inhibit another.

Neuroscientist Eleanor Maguire of University College London (U.C.L.) first got the idea to study London cab drivers from research on memory champions of the animal world. Some birds and mammals, such as western scrub jays and squirrels, cache food and dig it up later, which means they must memorize the locations of all their hiding spots. Researchers noticed that a part of the brain called the hippocampus was much larger in these animals than in similar species that did not secret away their snacks. The hippocampus is a seahorse-shaped section in the vertebrate brain that is crucial for long-term memory and spatial navigation.

Maguire wondered whether London taxi drivers also had larger-than-average hippocampi. To earn their licenses, cab drivers in training spend three to four years driving around the city on mopeds, memorizing a labyrinth of 25,000 streets within a 10-kilometer radius of Charing Cross train station, as well as thousands of tourist attractions and hot spots. “The Knowledge,” as it is called, is unique to London taxi licensing and involves a series of grueling exams that only about 50 percent of hopefuls pass.

In her earliest studies, Maguire discovered that London taxi drivers had more gray matter in their posterior hippocampi than people who were similar in age, education and intelligence, but who did not drive taxis. In other words, taxi drivers had plumper memory centers than their peers. It seemed that the longer someone had been driving a taxi, the larger his hippocampus, as though the brain expanded to accommodate the cognitive demands of navigating London’s streets. But it was also possible that The Knowledge selected for people whose memory centers were larger than average in the first place.

To find out which possibility was more likely, Maguire and her U.C.L. colleague Katherine Woollett decided to follow a group of 79 aspiring taxi drivers for four years to measure the growth of their hippocampi with magnetic resonance imaging (MRI) as they completed The Knowledge. For the sake of comparison, Maguire also measured brain growth in 31 people who did not drive taxis but were of similar age, education and intelligence as the taxi trainees. At the start of the study, all of the participants had more or less the same size hippocampi. Maguire also made sure that the aspiring cabbies and non-taxi drivers performed similarly on tests of working memory and long-term memory.

Four years later 39 of the 79 trainees had earned their licenses; 20 trainees who failed their exams agreed to continue participating in the study. When Maguire gave the successful and disappointed trainees the same battery of memory tests she had given them at the start of their training, she found that drivers who earned their licenses performed far better than those who failed—even though they had performed equally four years earlier. And MRIs showed that the successful trainees’ hippocampi had grown over time.

There are several ways to explain the ballooning hippocampus. The hippocampus may grow new neurons or hippocampal neurons may make more connections with one another. Non-neuronal cells called glial cells, which help support and protect neurons, may also contribute to the increase in hippocampal volume, although they are not generated as quickly as neurons.

The successful trainees did not perform better on all tests of memory, however. Licensed taxi drivers did worse than non-taxi drivers on a test of visual memory called the Rey-Osterrieth Complex Figure Test: The subject is asked to study what looks like a dollhouse designed by a loony architect, full of superfluous lines and squiggles, and sketch it from memory 30 minutes later.

Maguire thinks that The Knowledge may enlarge the hippocampus’s posterior (rear) at the expense of its anterior (front), creating a trade-off of cognitive talents—that is, taxi drivers master some forms of memory but become worse at others. In her earlier work, Maguire found evidence that, whereas the rear of the hippocampus was bigger in taxi drivers, the front was usually smaller than average. She didn’t find this same difference in her new study because, she speculates, front-end shrinkage may happen after the four years of training. The hippocampus’s rear section seems to be important for spatial navigation specifically, but Maguire says the front end’s role remains more mysterious.

Maguire says she was “greatly relieved” by the results of her study, which appears in the December issue of Current Biology. “We didn’t know how long the effects would take to appear on an MRI scan,” she says. “Maybe they only appeared quite some time after the trainees qualified. But we found them within the five years it took to do the study.”

Neurobiologist Howard Eichenbaum of Boston University commends the study for answering the “chicken-and-egg question” posed by Maguire’s earlier research. He sees it as confirmation of the idea that cognitive exercise produces physical changes in the brain. “The initial findings could have been explained by a correlation, that people with big hippocampi become taxi drivers,” he says. “But it turns out it really was the training process that caused the growth in the brain. It shows you can produce profound changes in the brain with training.

That’s a big deal.”

#Taxi #Neurologie #Hirnforschung

Les émissions mondiales de CO2 sont de retour à leur niveau pré-COVID
▻https://sciencepost.fr/emissions-co2-retour-niveau-pre-covid

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Global Emissions Rebound to Pre-COVID Levels - Scientific American
▻https://www.scientificamerican.com/article/global-emissions-rebound-to-pre-covid-levels

Like millions of people around the world, we’re watching the Glasgow climate change conference carefully. Pledges to end deforestation could reduce five or more billion tons of carbon dioxide pollution a year, while preserving global biodiversity. Additionally, at Glasgow, more than 40 countries have pledged to phase out coal use. Notable countries missing from the list include China, India, Australia and the United States.

L’abolition carcérale doit inclure la psychiatrie
▻https://infokiosques.net/spip.php?article1844

« En anglais, le mouvement pour l’abolition fait généralement référence aux luttes anticarcérales. Ce mouvement recouvre les luttes contre les prisons, le système pénal, les forces de l’ordre et l’industrie qui tire profit de ce système. Ces luttes visent ainsi à mettre fin aux pratiques d’enfermement, de punition, de coercition, de contrôle social et de ségrégation. Il s’agit également d’expérimenter des façons non-oppressives de répondre aux besoins de sécurité, de résolution de conflits et de gestion de crises. Cependant, l’abolition est aussi un objectif central pour l’antipsychiatrie et l’antivalidisme, puisque la fin de l’institutionnalisation des personnes handies et psychiatrisées est une condition essentielle à notre émancipation. (...) Les recoupements entre les luttes antipsychiatriques et (...)

#A #Prison,_justice,_répression #Antipsychiatrie #Infokiosque_fantôme_partout_
▻https://fr.m.wikipedia.org/wiki/Psychophobie
▻https://www.nytimes.com/2019/04/17/magazine/prison-abolition-ruth-wilson-gilmore.html
▻https://www.aaihs.org/prison-abolition-syllabus-2-0
▻https://docs.google.com/document/d/1WvhS43qeMzm7qQ1iDCWshCNCZQLUZ6IazRlsJDFlQ5E/mobilebasic
▻https://www.madinamerica.com/2020/03/report-psychiatric-interventions-torture
▻https://blog.usejournal.com/we-dont-need-cops-to-become-social-workers-we-need-peer-support-b8e
▻https://projectlets.org/blog/asylums
▻http://www.luhrmann.net/wp-content/uploads/2012/02/social-defeat.pdf
▻https://www.scientificamerican.com/article/is-depression-just-bad-chemistry
▻https://www.ncmhr.org/downloads/ADA-Legacy-Project-Mental-Health-CSX-Movement-History-Milestones.pdf
▻https://www.madinamerica.com/2018/12/mia-survey-force-trauma-sexual-abuse-mental-hospitals
▻https://www.polk.k12.ga.us/userfiles/644/Classes/177912/Code%20of%20Ur-Nammu.pdf
▻https://cssp.org/2019/11/honoring-the-global-indigenous-roots-of-restorative-justice/#:~:text=Talking%20circles%20is%20another%20approach,each%20other%20and%20the%.
▻http://www.review.upeace.org/pdf.cfm?articulo=124&ejemplar=23
▻https://www.researchgate.net/publication/12069122_Postpsychiatry_A_new_direction_for_mental_health
▻https://www.pbs.org/wgbh/aia/part4/4h3106t.html
▻https://en.wikipedia.org/wiki/Disability_justice
▻https://projectlets.org
▻http://www.hearing-voices.org
▻https://www.madinamerica.com
▻https://www.sinsinvalid.org
▻https://www.healthjusticecommons.org
▻https://www.westernmassrlc.org
▻https://behearddc.org
▻https://disabilityvisibilityproject.com/2020/07/22/abolition-must-include-psychiatry
▻https://infokiosques.net/IMG/pdf/l_abolition_carcerale_doit_inclure_la_psychiatrie-cahier-juillet2020-4
▻https://infokiosques.net/IMG/pdf/l_abolition_carcerale_doit_inclure_la_psychiatrie-fil-juillet2020-8pA5

The Coronavirus Variants Don’t Seem to Be Highly Variable So Far - Scientific American
▻https://www.scientificamerican.com/article/the-coronavirus-variants-dont-seem-to-be-highly-variable-so-far

No doubt you’ve heard about the novel coronavirus variants that are evolving around the world. There now appear to be more than a dozen versions of SARS-CoV-2, which are of varying degrees of concern because some are linked to increased infectivity and lethality while others are not. It’s easy to be overwhelmed by this diversity and to fear that we’ll never achieve herd immunity. Yet evidence is growing that these variants share similar combinations of mutations. This may not be the multifront war that many are dreading, with an infinite number of new viral versions.
I am an evolutionary microbiologist who studies how bacteria and viruses adapt to new environments or hosts. Like many microbiologists, my colleagues and I have turned our attention to understanding how SARS-CoV-2 is evolving adaptations for reproducing and transmitting in humans. Our favorite laboratory method is experimental evolution, where we grow multiple populations of microbes started from the same strain under identical conditions for weeks or months. We study problems like how antibiotic resistance evolves and how infections become chronic. The power of this method is that using multiple populations allows us to “replay the tape of life” and study how repeatable and ultimately predictable evolution might be.
One pattern we see is called convergent evolution, where the same trait emerges in different independent lineages over time, usually as they adapt to similar environments. Some of the best examples of convergent evolution include the sandy color of diverse desert animals; lobed swimming fins for whales, walruses, and manatees (which are actually distantly related); and even the ability for humans to digest lactose into adulthood, which arose several times in geographically isolated populations.

In the case of SARS-CoV-2, the complete genome sequences of viruses from thousands of patients enable us to look for convergent patterns. While most mutations are one-offs that go extinct, some establish new lineages that become more frequent as the virus succeeds in replicating and infecting many people. If the same part of the virus repeatedly mutates in different samples around the world and becomes more frequent, this mutation very likely encodes an adaptation that helps the virus reproduce and transmit.
With the benefit of increased genome surveillance of the coronavirus, several recent studies have identified signatures of convergent evolution. Here in the U.S. our laboratory found at least seven genetically independent lineages that acquired a mutation at one particular spot on the virus’s infamous spike protein, the one it uses to latch onto human cells. Spike has a sequence of linked amino acids, and the mutation occurs at position number 677. In the original SARS-CoV-2 this is the amino acid glutamine, abbreviated as Q.

In six lineages, this Q mutated to another amino acid, histidine (H) and is called 677H. In the seventh lineage, Q mutated to another amino acid, proline (P). Each lineage also has a mutation called S:614G, which was the first notable change in the virus to be identified several months ago and spread so widely it is now found in 90 percent of all infections. We named these seven U.S. lineages after common birds—“robin,” for example, and “pelican” —to help us distinguish and track them, and also to avoid creating prejudice by naming them after the areas where they were first detected.

Lineages outside the U.S. have also acquired 677H, including in Egypt, Denmark, India and a large cluster in Macedonia. A new variant of concern called B.1.525 also has 677H, as do several lineages that descended from B.1.1.7, one of the first worrisome versions to be spotted. The coincident, global emergence of S:677 mutations and their fivefold gain in prevalence offers strong evidence that these changes must improve viral fitness in some way. We don’t know how yet, but it is noteworthy that S:677 borders a region of the spike protein that helps the virus enter and infect human cells. 

This is far from the only example of convergence in SARS-CoV-2. Mutations in at least eight different positions in the spike protein are simultaneously on the rise around the world, appearing in B.1.1.7 and in other major variants of concern known as B.1.351, P.1 and P.3. These variants share combinations of mutations at positions 18, 69–70, 417, 452, 501, 681 and a particularly concerning E484K mutation that evades neutralizing antibodies. For this reason, two of the leading scientific websites (▻http://covariants.org and ▻http://outbreak.info) that track variants now report these shared, defining mutations to simplify and consolidate our attention. The U.S. Centers for Disease Control and the media have been slow to follow the importance of these key mutations, but this is changing, because it is these changes that likely alter virus functions such as contagiousness or the ability to evade vaccines.

One way to envision this type of convergent evolution is as a game of Tetris, where a limited number of building blocks can be assembled in different ways, in different combinations, to achieve the same winning structures. For example, it is now known that the combination of mutations in B.1.1.7 make it especially contagious, and that the B.1.351 lineage can evade antibodies because of E484K.
Because many newly discovered variants appear to be resampling the mutations found in other established variants, we can speculate that the virus is beginning to run out of new, major adaptations. But this doesn’t mean that that the forces of evolution will stop as we begin to approach herd immunity and loosen restrictions. History tells us that viruses can evolve rapidly to evade barriers to transmission, especially when infections remain numerous. We must remember that the more infections there are, the more chance mutations will occur, and those that best help the virus to survive will proliferate. This is why stopping new infections is key. These viral adaptations are already rewriting our biology textbooks on convergent evolution; let’s strive to limit new material.

It’s also critical that we make significant investments in building an early-warning system to detect new #SARS-CoV-2 variants as well as many other emerging pathogens, both known and yet to be discovered. Viral genome surveillance and sequencing is the key. The reason why many variants have been detected in the U.K. is because of visionary investments by researchers and public health officials in these technologies.
In the U.S., a significant influx of money to the CDC from the new federal stimulus package is already increasing the frequency with which researchers can sequence and analyze virus samples. This must be sustained by building the public health expertise and research infrastructure to decode genetic changes in the virus and anticipate the need for future vaccine modifications. It was basic science that provided hope in this pandemic through new vaccine technology; and given renewed support it will also be our guardian against future threats.

#séquençage #variants

Pesticides Are Killing the World’s Soils - Scientific American
▻https://www.scientificamerican.com/article/pesticides-are-killing-the-worlds-soils/#click=https://t.co/viDIqBeia9

The ongoing escalation of pesticide-intensive #agriculture and #pollution are major driving factors in the precipitous decline of many soil organisms, like ground beetles and ground-nesting bees. They have been identified as the most significant driver of soil biodiversity loss in the last decade.

Yet pesticide companies and our #pesticide regulators have ignored that research.

The #EPA, which is responsible for pesticide oversight in the U.S., openly acknowledges that somewhere between 50 percent to 100 percent of all agriculturally applied #pesticides end up on the soil. Yet to assess pesticides’ harms to soil species, the agency still uses a single test species—one that spends its entire life above ground in artificial boxes to estimate risk to all soil organisms—the European honeybee.

Source : Pesticides and Soil Invertebrates: A Hazard Assessment
▻https://www.frontiersin.org/articles/10.3389/fenvs.2021.643847/full

#sols #etats-unis

Fields Medals Are Concentrated in Mathematical ’Families’ - Scientific American
▻https://www.scientificamerican.com/article/fields-medals-are-concentrated-in-mathematical-families

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#visualisation de Shirley Wu

Flu Has Disappeared Worldwide during the #COVID Pandemic - Scientific American
▻https://www.scientificamerican.com/article/flu-has-disappeared-worldwide-during-the-covid-pandemic

Because each year’s flu vaccine is based on strains that have been circulating during the past year, it is unclear how next year’s vaccine will fare, should the typical patterns of the disease return. The WHO made its flu strain recommendations for vaccines in late February as usual, but they were based on far fewer cases than in a common year. At the same time, with fewer virus particles circulating in the world, there is less chance of an upcoming mutation, so it is possible the 2021–2022 vaccine will prove extra effective.

https://static.scientificamerican.com/sciam/assets/Image/2021/fluUpdate_graphic_m.png

#grippe

The Myth of Stephen Hawking - Scientific American
▻https://www.scientificamerican.com/article/the-myth-of-stephen-hawking

Hawking managed to convince the public that his opinion always mattered. “[H]is comments attracted exaggerated attention even on topics where he had no special expertise,” wrote Martin Rees, a close friend and colleague of his, “for instance philosophy, or the dangers from aliens or from intelligent machines.” His overweening confidence—and his stubbornness—cost him respect from many of his colleagues, especially late in his career.
(...)
The cost to Hawking was that the myth obscured the humanity of the person behind it. In truth, Hawking was not the greatest scientist of our time. He was an important physicist whose importance is almost universally misunderstood; a person who suffered deeply and also caused deep suffering; a celebrity scientist who broke the mold of his forebears and fundamentally changed the concept of a scientific celebrity. To truly understand Hawking—just as to truly understand science—one has to reject the myth and examine the messy reality underneath. To stop looking at Hawking as a prophet, but instead as a flawed and brilliant human being.

The Antiscience Movement Is Escalating, Going Global and Killing Thousands - Scientific American
▻https://www.scientificamerican.com/article/the-antiscience-movement-is-escalating-going-global-and-killing-

https://static.scientificamerican.com/sciam/cache/file/17484515-FB8F-4F74-882DAE57C0308AA3.jpg

Antiscience is the rejection of mainstream scientific views and methods or their replacement with unproven or deliberately misleading theories, often for nefarious and political gains. It targets prominent scientists and attempts to discredit them. The destructive potential of antiscience was fully realized in the U.S.S.R. under Joseph Stalin. Millions of Russian peasants died from starvation and famine during the 1930s and 1940s because Stalin embraced the pseudoscientific views of Trofim Lysenko that promoted catastrophic wheat and other harvest failures. Soviet scientists who did not share Lysenko’s “vernalization” theories lost their positions or, like the plant geneticist, Nikolai Vavilov, starved to death in a gulag.

Now antiscience is causing mass deaths once again in this COVID-19 pandemic. Beginning in the spring of 2020, the Trump White House launched a coordinated disinformation campaign that dismissed the severity of the epidemic in the United States, attributed COVID deaths to other causes, claimed hospital admissions were due to a catch-up in elective surgeries, and asserted that ultimately that the epidemic would spontaneously evaporate. It also promoted hydroxychloroquine as a spectacular cure, while downplaying the importance of masks. Other authoritarian or populist regimes in Brazil, Mexico, Nicaragua, Philippines and Tanzania adopted some or all of these elements.

A City in Brazil’s Amazon Rain Forest Is a Stark Warning about COVID to the Rest of the World - Scientific American
▻https://www.scientificamerican.com/article/a-city-in-brazils-amazon-rain-forest-is-a-stark-warning-about-co

the dire scenes in the Amazon—hospital systems collapsing, grave diggers carving out trenches for mass graves shared by multiple bodies, and families desperately queuing for oxygen supplies—will send a clear message: “Herd immunity through infection, instead of a vaccine, only comes with an enormous amount of illness and death,” Hanage says.

“Despite their relatively small size, the graveyards were found to be home to a total of 81 native plant species; the non–burial plots in the wheat fields had a total of 34. Even the smallest graveyard in the study, covering just two square meters, hosted 24 plant species.”

▻https://www.scientificamerican.com/article/graveyards-are-surprising-hotspots-for-biodiversity

#graveyards #cemetery #wild_life_preservation #biodiversity

The Second-Generation COVID Vaccines Are Coming - Scientific American
▻https://www.scientificamerican.com/article/the-second-generation-covid-vaccines-are-coming

https://static.scientificamerican.com/sciam/cache/file/3F825C08-7E40-4609-A74494186EF508DA.jpg

There are nearly 240 novel vaccine candidates in development, waiting in the wings for their moment. Here are a few that show the most potential.

#vaccins

Pour ce chercheur de Harvard, c’est bien un vaisseau extraterrestre qui est venu nous voir en 2017
▻https://www.ouest-france.fr/sciences/espace/pour-ce-chercheur-de-harvard-c-est-bien-un-vaisseau-extraterrestre-qui-

En 2017, le passage d’un étrange corps céleste dans notre système solaire, baptisé Oumuamua (« le messager » en hawaïen), a mis les astronomes en émoi. À tel point que certains y ont vu l’émanation d’une vie extraterrestre. Une thèse évidemment controversée, mais qu’un scientifique réputé, Avi Loeb, défend toujours dans un ouvrage publié jeudi 28 janvier. Avec quelques arguments.

« Si j’ai raison, c’est la plus grande découverte de l’histoire de l’humanité »​, avertit carrément Avi Loeb, directeur du département d’astronomie de l’Université de Harvard. La phrase claque sur le bandeau publicitaire rouge posé par l’éditeur français, Le Seuil, sur la couverture du livre, intitulé Le premier signe d’une vie intelligente extraterrestre.

Un ouvrage publié jeudi 28 janvier partout dans le monde et consacré à Oumuamua, cet étrange objet en forme de cigare rougeâtre qui a traversé notre système solaire à toute vitesse, en 2017.

Repéré le 19 octobre de cette année-là par le télescope Pan-Starrs1 à Hawaï, Oumuamua (qui signifie « le messager » en hawaïen) mesure 400 mètres de longueur et 40 mètres de largeur. Sa vitesse est si élevée qu’il ne peut provenir que d’une étoile distante – en l’occurrence Vega. Et surtout, c’est le premier corps céleste détecté venant d’un autre système stellaire.

Une accélération bizarre et une forme insolite

Question : comment qualifier cet étrange objet ? C’est un astéroïde affirment d’abord les astronomes. Avant qu’une équipe de l’Agence spatiale européenne estime qu’il s’agit plus probablement d’une comète venue de très loin.

Mais ces deux hypothèses laissent quelques chercheurs sur leur faim. À commencer par Avi Loeb, donc, directeur de l’Institut de théorie et de calcul (ITC) du Centre d’astrophysique Harvard-Smithsonian et spécialiste des trous noirs. Selon lui, ces hypothèses ne permettent pas d’expliquer l’accélération de ce corps céleste, ni sa forme insolite, ni le fait qu’il n’ait dégagé aucune traînée – gaz ou poussières – en passant à proximité du Soleil.

Avec un jeune associé de recherche, Shmuel Bialy, Avi Loeb publie alors un article dans la très sérieuse revue Astrophysical Journal Letters, avançant la théorie que Oumuamua ne peut être qu’une sonde propulsée par une civilisation extraterrestre.

Leur publication est évidemment vivement critiquée. Aujourd’hui, écrit Avi Loeb dans son livre, « le débat se prolonge faute de preuves tangibles » et « quoi que l’on finisse par conclure au sujet de Oumuamua, force est de constater qu’il a été, et demeure, une anomalie en soi ».

De curieux et surprenants mouvements saccadés

En 270 pages, le physicien américano-Israélien expose ses hypothèses sur « ce premier visiteur interstellaire jamais identifié » et « explore la question de savoir si nous sommes seuls dans l’Univers », expliquent les éditions du Seuil.

« Il nous faut garder l’esprit ouvert sur les possibilités de ce qui existe dans l’espace – en particulier la vie. Sinon, nous pourrions rater quelque chose d’étonnant, comme les responsables de l’Église du XVIIe siècle qui ont refusé de regarder à travers le télescope de Galilée. »

Il est vrai qu’Oumuamua n’a rien de commun. Il a ainsi montré aux télescopes du monde entier de curieux et surprenants mouvements saccadés alors qu’il quittait notre système solaire.

Certains astronomes ont alors conclu que ce corps céleste était une comète « étrange »​, accélérée, bousculée par des jets de gaz qui devaient s’évaporer à sa surface – sauf qu’aucun gaz de ce type n’a été détecté. Et qu’un curieux manteau organique nappe sa surface.

Comme le raconte le New York Times , il est vrai que Loeb, élevé dans une ferme en Israël, fils de réfugiés de l’Holocauste et d’une Europe déchirée par la guerre, est l’un des scientifiques les plus imaginatifs de notre temps.

Il écrit fréquemment pour Scientific American et sur un large éventail de sujets – de la cosmologie aux trous noirs en passant par l’opportunité d’inspecter les atmosphères des exoplanètes à la recherche de signes de pollution industrielle ou même de guerre nucléaire.

Il est aussi président de la Black Hole Initiative, à Harvard, et président du comité consultatif scientifique de Breakthrough Starshot, un projet visant à envoyer de minuscules sondes à Alpha Centauri (système stellaire et planétaire le plus proche du système solaire), propulsées à un cinquième de la vitesse de la lumière par des voiles solaires.

Rechercher des « bio-signatures »

Ces voiles solaires n’ont rien d’une ineptie : voilà plus de trente ans que les scientifiques les plus sérieux construisent des prototypes d’objets mus par le vent solaire et ses photons.

Plusieurs engins de petite taille, destinés à mettre au point les systèmes de déploiement et de contrôle d’orientation de ces voiles, ont été placés en orbite ou sont en cours de développement : Ikaros (173 m²) de l’agence spatiale japonaise, lancé en 2010, ou Sunjammer, voile solaire de 1 200 m² dont le développement a été conduit par la Nasa jusqu’en 2014.

Pour Avi Loeb, les caractéristiques lumineuses et les capacités d’accélération d’Oumuamua à son passage au sein de notre système solaire plaiderait en faveur d’une sonde mue par la même énergie.

La science académique moderne, se plaint-il, a surévalué des sujets tels que les univers multiples, pour lesquels il n’y a aucune preuve, et sous-évalué la recherche de la vie dans l’espace, « non seulement sous la forme de signaux radio extraterrestres, mais sous la forme de produits chimiques, de bio-signatures », ou même « des artefacts technologiques, comme Oumuamua »​. Il milite pour aller au-delà de la quête d’une vie microbienne sur Mars, objectif de la mission Perseverance de la Nasa.

Et Loeb, cité par le New York Times, de poser cette conclusion douce-amère : « Dès que nous saurons que nous ne sommes pas seuls, que nous ne sommes pas la civilisation la plus avancée à avoir jamais existée dans le cosmos, nous comprendrons que nous aurons dépensé plus d’argent pour développer les moyens de détruire la vie sur notre planète qu’il n’en aurait coûté pour la préserver. »

Et là, nul besoin de venir de l’autre bout de l’Univers ou de croire à l’existence d’E.T. pour apprécier la justesse de son analyse.

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