publishedmedium:scientific american

New Method for Tackling Stroke Restrains an Overactive Immune System - Scientific American
▻https://www.scientificamerican.com/article/new-method-for-tackling-stroke-restrains-an-overactive-immune-sy

https://static.scientificamerican.com/sciam/cache/file/4F41D532-7C95-4323-BFA177390761DEDE.jpg

The pathology of a stroke is deceptively complicated. In the simplest sense, strokes occur when the blood supply to a particular region of the brain is interrupted, cutting off the area to oxygen and nutrients. This deprivation results in injury and death to the local brain cells.

But for days after the breach in blood flow, the immune system also does its own fair share of damage to the already injured brain through an inflammatory response.

#immunologie #inflammation #infarctus #cerveau

What Is the Point of a Period? - Scientific American
▻https://www.scientificamerican.com/article/what-is-the-point-of-a-period

https://static.scientificamerican.com/sciam/assets/Image/saw0519Sole31_pan_zoom.jpg

Age-old taboos against menstruation have led to a lack of research on how women’s cycles work, with serious consequences for their health

#règles #cycle #menstruation #visualisation (et joli titre)

Simple Sugars Wipe Out Beneficial Gut Bugs - Scientific American
▻https://www.scientificamerican.com/podcast/episode/simple-sugars-wipe-out-beneficial-gut-bugs

https://static.scientificamerican.com/sciam/cache/file/B24A3360-0B55-43FC-9EEC437CB91E10FC.jpg

“[...] what our work actually shows is that both fructose and sucrose do make it to the colon where the microbiota exist. And second that these sugars impact a good bacterium even though nutrition is not involved.”

In other words, the bacteria are not using fructose and sucrose as food. Instead, the sugars serve as signals that shut down production of a protein that beneficial Bacteroides need to colonize the intestine. The findings appear in the Proceedings of the National Academy of Sciences. [Guy E. Townsend II et al., Dietary sugar silences a colonization factor in a mammalian gut symbiont]

Groisman says he’d like to explore whether complex polysaccharides can save Bacteroides from this sugary death sentence. Because then maybe we can eat cake and have our gut bugs too.

#sucres #microbiote #colon

Income Inequality’s Most Disturbing Side Effect : #Homicide - Scientific American
▻https://www.scientificamerican.com/article/income-inequalitys-most-disturbing-side-effect-homicide

https://static.scientificamerican.com/sciam/cache/file/5598A7F5-BA74-451C-8684A1E4818F826B.jpg

Income inequality can cause all kinds of problems across the economic spectrum—but perhaps the most frightening is homicide. Inequality—the gap between a society’s richest and poorest—predicts murder rates better than any other variable, according to Martin Daly, a professor emeritus of psychology at McMaster University in Ontario, who has studied this connection for decades. It is more tightly tied to murder than straightforward poverty, for example, or drug abuse. And research conducted for the World Bank finds that both between and within countries, about half the variance in murder rates can be accounted for by looking at the most common measure of inequality, which is known as the Gini coefficient.

#inégalité

Weeds Are Winning in the War against Herbicide Resistance - Scientific American
▻https://www.scientificamerican.com/article/weeds-are-winning-in-the-war-against-herbicide-resistance

https://static.scientificamerican.com/sciam/cache/file/6BCEEBB9-3F14-4CF0-BCF655C37B20FA3A_agenda.jpg?w=600&h=335

#herbes #herbicides #pesticides #agriculture

Memory Transferred between Snails, Challenging Standard Theory of H...
▻https://diasp.eu/p/7188607

Memory Transferred between Snails, Challenging Standard Theory of How the Brain Remembers - Scientific American | #engrams #RNA #memory #snails #epigenetics

Food for Thought: Was Cooking a Pivotal Step in Human Evolution? - Scientific American
▻https://www.scientificamerican.com/article/food-for-thought-was-cooking-a-pivotal-step-in-human-evolution

https://static.scientificamerican.com/sciam/cache/file/AFE760DA-5803-4BEE-93DA025EEFFA78D7_agenda.jpg?w=600&h=335

These converging pieces of evidence point to an earlier date for the adoption of a cooked diet, in line with Wrangham’s proposed time line. But many exciting questions remain open. How much of these changes were due to eating cooked foods specifically, versus the increased use of other processing techniques such as pounding or cutting foods? Did the adoption of cooking—generally a communal process in humans—require changes in our social behavior, given that other apes rarely share food? Are there other ways to grow a big brain? Answering these questions will continue to shed new light on human health, human psychology and the origins of our species.

#cuisson #transformation #aliments #organes #cerveau #évolution

Wait—the #Ozone Layer Is Still Declining? - Scientific American
▻https://www.scientificamerican.com/article/wait-the-ozone-layer-is-still-declining1

https://www.scientificamerican.com/sciam/cache/file/CAB1C59F-2C3D-4C4E-BE71F1C678072460_agenda.jpg?w=600&h=335

Ball and a team of researchers from institutions around the world wanted to more accurately measure trends in the ozone layer. For their study, they synthesized and then analyzed multiple satellite data sets of atmospheric ozone. The data cover the tropics and mid-latitudes, from 1985 through 2016. The team found ozone in the upper stratosphere has indeed rebounded since 1998. “It’s clear it’s going back up,” Ball says. “This is exactly where we’d expect to see the Montreal Protocol working its best.” They also discovered ozone in the troposphere—which comes in large part from air pollution—rose from 2004 through 2016.

They observed, however, no significant upward or downward trends for the middle stratosphere, or for the total ozone column—the sum of the troposphere and stratosphere—since 1998. Starting in 1985 “you can see [the total ozone column] is going down,” Ball says. “After 1998 we see ozone stop depleting, initially see a slight rise and then it seems to stall.” But the rise was statistically nonsignificant, Ball notes. “What this says is, great, since 1998 ozone hasn’t been depleting any further.” But it also does not appear to be rebounding.

What is the culprit? Ball’s team found the ozone in the lower stratosphere has slowly, continuously dropped since 1998. “We see a small but persistent and continuous decline—not as fast as before 1998 but a continued [trend] down,” he says. “This is surprising, because we would have expected to also see this [region’s ozone] stop decreasing.” The finding is important because the lower stratosphere contains the largest fraction of the ozone layer.

New Map Shows the Dark Side of Artificial Light at Night - Scientific American
▻https://www.scientificamerican.com/article/new-map-shows-the-dark-side-of-artificial-light-at-night

https://www.scientificamerican.com/sciam/cache/file/5DF39036-A8E2-4D73-AB29991276B4EC0B_agenda.jpg?w=600&h=335

Beyond the obvious downsides of light pollution—such as grumbling astronomers or sea turtle hatchlings and migrating birds drawn off course by bright lights—most of its related effects are surprisingly hard to quantify. Researchers still lack deep understanding of the complex relationships between many nocturnal predators and prey, let alone how varying levels of artificial light changes them. For humans the effects are similarly muddled. Based on multiple epidemiological studies, the World Health Organization in 2007 and the American Medical Association in 2012 each issued statements warning that extended exposure to light at night increases the risk of certain cancers, probably via alterations to circadian rhythms and associated hormone levels. Even so, most of these studies did not distinguish between exposure to outdoor sources, like streetlights, and indoor ones, like television and smartphone screens.

▻https://seenthis.net/messages/647946
#éclairage #pollution_lumineuse #santé

Creating the Scientific American Baby births visual - Visual Cinnamon
▻https://www.visualcinnamon.com/2017/10/creating-baby-births-visual.html

https://www.visualcinnamon.com/wp-content/uploads/2017/10/The-baby-spike-feature.jpg

On the Graphic Science page of the July edition of Scientific American you could find three large circular charts about when babies are born. In this blog, let me take you along on the data & designs process that me, Zan Armstrong & Jen Christiansen went through to create this piece.

#visualisation

Psychedelics work by violating our models of self and the world | Aeon Essays
▻https://aeon.co/essays/psychedelics-work-by-violating-our-models-of-self-and-the-world

https://omicron.aeon.co/images/df1aef71-6826-4274-9efc-442f8a178c3a/header_essay-ceremony-453598072_master.jpg

Psychedelic drugs are making a psychiatric comeback. After a lull of half a century, researchers are once again investigating the therapeutic benefits of psilocybin (‘magic mushrooms’) and LSD. It turns out that the hippies were on to something. There’s mounting evidence that psychedelic experiences can be genuinely transformative, especially for people suffering from intractable anxiety, depression and addiction. ‘It is simply unprecedented in psychiatry that a single dose of a medicine produces these kinds of dramatic and enduring results,’ Stephen Ross, the clinical director of the NYU Langone Center of Excellence on Addiction, told Scientific American in 2016.

Just what do these drugs do? Psychedelics reliably induce an altered state of consciousness known as ‘ego dissolution’. The term was invented, well before the tools of contemporary neuroscience became available, to describe sensations of self-transcendence: a feeling in which the mind is put in touch more directly and intensely with the world, producing a profound sense of connection and boundlessness.

How does all this help those with long-term psychiatric disorders? The truth is that no one quite knows how psychedelic therapy works.

Today there are neuroBuddhists, neuroCartesians and neuroHumeans all over the world, filling PowerPoint screens with images of fMRI scans supposedly congenial to their theory. Abnormal cognitive conditions, pathological or otherwise, serve as a crucial source of evidence in these debates, because they offer the chance to look at the self when it is not working ‘properly’. Data floods in but consensus remains elusive. However, the emerging neuroscience of psychedelics may help resolve this impasse. For the first time ever, scientists are in a position to watch the sense of self disintegrate and reintegrate – reliably, repeatedly and safely, in the neuroimaging scanner.

#Psychédéliques #conception_du_moi

Forget That Big Iceberg—A Smaller One in the Arctic Is More Troubling - Scientific American
▻https://www.scientificamerican.com/article/forget-that-big-iceberg-a-smaller-one-in-the-arctic-is-more-trou

https://www.scientificamerican.com/sciam/cache/file/E0A7FD82-959C-4984-AE6DA631DBCB4AC0_agenda.jpg?w=600&h=335

The Petermann Glacier in Greenland is showing signs of calving. Credit: Jesse Allen NASA Earth Observatory

#groenland #glacier #climat

How Wealth Reduces Compassion - Scientific American
▻https://www.scientificamerican.com/article/how-wealth-reduces-compassion

https://www.scientificamerican.com/sciam/cache/file/91A516E6-9309-4CFD-A5E7341EF5A42A7B_agenda.jpg?w=600&h=335

Who is more likely to lie, cheat, and steal—the poor person or the rich one? It’s temping to think that the wealthier you are, the more likely you are to act fairly. After all, if you already have enough for yourself, it’s easier to think about what others may need. But research suggests the opposite is true: as people climb the social ladder, their compassionate feelings towards other people decline.

Berkeley psychologists Paul Piff and Dacher Keltner ran several studies looking at whether social class (as measured by wealth, occupational prestige, and education) influences how much we care about the feelings of others.In one study, Piff and his colleagues discreetly observed the behavior of drivers at a busy four-way intersection. They found that luxury car drivers were more likely to cut off other motorists instead of waiting for their turn at the intersection. This was true for both men and women upper-class drivers, regardless of the time of day or the amount of traffic at the intersection. In a different study they found that luxury car drivers were also more likely to speed past a pedestrian trying to use a crosswalk, even after making eye contact with the pedestrian.

But why would wealth and status decrease our feelings of compassion for others? After all, it seems more likely that having few resources would lead to selfishness. Piff and his colleagues suspect that the answer may have something to do with how wealth and abundance give us a sense of freedom and independence from others. The less we have to rely on others, the less we may care about their feelings. This leads us towards being more self-focused. Another reason has to do with our attitudes towards greed. Like Gordon Gekko, upper-class people may be more likely to endorse the idea that “greed is good.” Piff and his colleagues found that wealthier people are more likely to agree with statements that greed is justified, beneficial, and morally defensible. These attitudes ended up predicting participants’ likelihood of engaging in unethical behavior.

#Richesse #Empathie #Antisocial

Why Are so Many Babies Born around 8:00 A.M.? - Scientific American Blog Network
▻https://blogs.scientificamerican.com/sa-visual/why-are-so-many-babies-born-around-8-00-a-m

Based on the stories we share, it would be easy to imagine that when a baby is born is random. In the U.S., however, weeks in September have 5 to 10 percent more births than weeks in January. Twelve thousand babies are born on a typical Tuesday compared with 8,000 on a typical Saturday. Sixty percent of babies are born during the day, between 6 A.M. and 6 P.M. And, 3.5 times as many babies are born at exactly 8:00 A.M., the most common minute to be born, than at the least common, 3:09 A.M.

The graphic below (developed by Nadieh Bremer and me for the July 2017 Scientific American) reveals these regular birth patterns. It shows what minutes of the day, hours of the week and weeks of the year are more common or less common than average.

https://blogs.scientificamerican.com/sciam/assets/Image/saw0717Gsci31_d.png

#naissances #bébés #dataviz

Living Large: How Whales Got to Be So Enormous - Scientific American
▻https://www.scientificamerican.com/article/living-large-how-whales-got-to-be-so-enormous1

https://www.scientificamerican.com/sciam/cache/file/12B300E3-CE16-4C50-A7EC5ED13394C48C_agenda.jpg?w=600&h=335

A new theory traces their gargantuan size to changing food sources during ice ages

#alimentation #baleines

Aspirin May Prevent Cancer from Spreading, New Research Shows - Scientific American
▻https://www.scientificamerican.com/article/aspirin-may-prevent-cancer-from-spreading-new-research-shows

https://www.scientificamerican.com/sciam/cache/file/D91F03D2-DDCC-476E-B1AAC3D2FFED3789_agenda.jpg?w=600&h=335

Not everyone responds equally well to the drug, however, and for some people it can be downright dangerous. Investigators are thus trying to develop genetic tests to determine who is most likely to benefit from long-term use of aspirin. The latest research into the drug’s cancer-inhibiting activity is generating findings that could possibly guide those efforts.

#aspirine #santé #cancer

Why Trendy Nanosilver Products Are Hazardous to Your Health and the Environment | Alternet
▻http://www.alternet.org/environment/why-trendy-nanosilver-products-are-hazardous-your-health-and-environment

http://www.alternet.org/files/story_images/shutterstock_73203946.jpg

Due to these developments, nanosilver has begun to appear in an increasing number of products. There are now over 400 products on the market that employ nanosilver technology, many of which involve direct contact with our bodies and our food, including clothing, sheets, blankets, cosmetics, soaps, nasal spray, hair straightener, ink, air purifiers, vegetable and fruit cleaners, cutting boards, vacuum cleaners and in Korea, even toothpaste.

Sounds too good to be true, right? It may be. Because the very thing that makes nanoparticles so effective—their size—is also what makes them a potential hazard. We still don’t fully know how nanosilver behaves when it’s released into the environment or absorbed by our bodies. A growing number of studies show that products containing nanosilver can shed these particles, which subsequently end up in wastewater or our bloodstream.

These rogue nanosilver particles pose a number of potential problems. As we’ve established, silver nanoparticles are highly toxic to bacteria and fungi. This is not good news for soil. Quoted in an article on Scientific American, Ben Colman, a research scientist at Duke University who conducted a study into the effects of nanosilver on soil systems, explained how these particles, “significantly altered [..] plant growth, microbial biomass and microbial activity.”

On the flipside, nanosilver toxicity poses a different threat to our own biology. The Center for Food Safety’s senior policy analyst Jaydee Hanson, quoted in an article on Civil Eats, noted that over time, overexposure to nanosilver, “may lead to bacteria becoming increasingly resistant to antibiotics.” A study conducted by the Norwegian Institute of Public Health further found that silver nanoparticles had a “toxic effect on cells, suppressing cellular growth and multiplication and causing cell death depending on concentrations and duration of exposure.”

In 2014, the European Commission and its non-food Scientific Committee on Emerging and Newly Identified Health Risks published findings under the comprehensive title, “Final Opinion on Nanosilver: safety, health and environmental effects and role in antimicrobial resistance.” SCENIHR found that in order to truly ascertain any potential hazards, more data was “needed to better understand bacterial response...to silver nanoparticles exposure.”

#nanoparticules #nano-argent #effets_secondaires

Great Literature Is Surprisingly Arithmetic - Scientific American
▻https://www.scientificamerican.com/article/great-literature-is-surprisingly-arithmetic

almost all novels and plays provide one of only six “emotional experiences” from beginning to end—a rags-to-riches exuberance, say, or a rise and fall of hope (below, top). Researchers at the University of Vermont graphed the happiness and sadness of words that occurred across the pages of more than 1,300 fiction works to reveal the emotional arcs and discovered relatively few variations.

https://www.scientificamerican.com/sciam/cache/file/E3A2D659-B536-428A-92BDC512E395AA69_source.png

A different study coordinated by Poland’s Institute of Nuclear Physics found that sentence lengths in books frequently form a fractal pattern

reminds me of Kurt Vonnegut’s shape of stories ▻http://www.openculture.com/2014/02/kurt-vonnegut-masters-thesis-rejected-by-u-chicago.html
►https://www.youtube.com/watch?v=oP3c1h8v2ZQ

#romans #text-mining #récits #écrire #culturomics

cf ▻https://seenthis.net/messages/507621

#Trump Picks Top Climate Skeptic to Lead EPA Transition - Scientific American

▻https://www.scientificamerican.com/article/trump-picks-top-climate-skeptic-to-lead-epa-transition

Donald Trump has selected one of the best-known climate skeptics to lead his U.S. EPA transition team, according to two sources close to the campaign.

Myron Ebell, director of the Center for Energy and Environment at the conservative Competitive Enterprise Institute, is spearheading Trump’s transition plans for EPA, the sources said.

The Trump team has also lined up leaders for its Energy Department and Interior Department teams. Republican energy lobbyist Mike McKenna is heading the DOE team; former Interior Department solicitor David Bernhardt is leading the effort for that agency, according to sources close to the campaign.

#climat #états-unis #epa

Big Pharma’s Manufactured Epidemic: The Misdiagnosis of ADHD - Scientific American
▻https://www.scientificamerican.com/article/big-pharma-s-manufactured-epidemic-the-misdiagnosis-of-adhd

ADHD itself is not an epidemic—ADHD misdiagnosis is an epidemic. If the system functioned in such a way as to stay anywhere near the 5percent diagnosis rate that the American Psychiatric Association’s official definition suggests, we wouldn’t be in this mess. But the system doesn’t function properly, not by a long shot. About 15 percent of American children turn 18 having been diagnosed with ADHD, 20 percent of boys, and 30 percent of boys in much of the South. It’s completely indefensible. It’s time to figure out how not to necessarily “fix” it, because the genie long left the bottle, but do a far better job in diagnosing the kids who really fit the construct and help the other kids in other ways. Many kids have problems and need help—but those problems in many cases will derive from trauma, anxiety, family discord, poor sleep or diet, bullying at school and more. We must not abandon them. We must help. But we must also be more judicious in how we do that, rather than reflexively giving them a diagnosis of what is generally described as a serious, lifelong brain disorder.

Scott Aaronson Answers Every Ridiculously Big Question I Throw at Him - Scientific American
▻http://blogs.scientificamerican.com/cross-check/scott-aaronson-answers-every-ridiculously-big-question-i-t

http://blogs.scientificamerican.com/blogs/cache/file/BEDBD89C-B016-481A-B8E426FE0B5F6FF3.jpg?w=590&h=395

Quantum-computer whiz riffs on simulated universes, the Singularity, unified theories, P/NP, the mind-body problem, free will, why there’s something rather than nothing, and more.

entretien avec un spécialiste de l’#informatique_quantique (première fois que je comprends un peu de quoi il s’agit)

#mathématiques #recherche

Curb Antibiotic Use in Farm Animals - Scientific American
▻http://www.scientificamerican.com/article/curb-antibiotic-use-in-farm-animals

http://www.scientificamerican.com/sciam/cache/file/4BD3370D-4B5E-4B7B-A6B7A931589D62DF_agenda.jpg?w=600&h=335

In 2013 the Food and Drug Administration finally stepped in, asking drug companies to stop selling antibiotics for the purpose of promoting the growth of animals by December 2016. The agency still allows the use of these drugs for “disease prevention,” however—that is, to fight off infections animals have not yet gotten. In principle, it might sound reasonable. In practice, this loophole may be big enough to allow farmers to continue with what they have been doing all along, raising concerns that the fda’s plan will not amount to much.

To make things worse, the #FDA resisted developing a meaningful plan to evaluate the effect of its action. Instead it intends simply to rely on sales data from drug companies to see whether its (nonbinding) guidelines are actually working. These data are far from ideal for this purpose; even the agency acknowledges that sales are not a reliable way to gauge how antibiotics are really being used.

How Nations Fare in PhDs by Sex [Interactive] - Scientific American

▻http://www.scientificamerican.com/article/how-nations-fare-in-phds-by-sex-interactive1

http://www.scientificamerican.com/sciam/cache/file/A650E741-3204-446B-97CFD20916AC0400_agenda.jpg?w=600&h=335



https://dl.dropbox.com/s/j790kjoz6ytm2jw/gender.png?dl=0

In the U.S., women are going to college and majoring in science and engineering fields in increasing numbers, yet here and around the world they remain underrepresented in the workforce. Comparative figures are hard to come by, but a disparity shows up in the number of Ph.D.s awarded to women and men. The chart here, assembled from data collected by the National Science Foundation, traces the gender gap at the doctoral level for 56 nations. The situation in individual countries varies widely, but as the numbers make clear, there are interesting exceptions to the global trend.

#études_supérieures #éducations #inégalités

10 Breaking Points - Issue 31: Stress
▻http://nautil.us/issue/31/stress/10-breaking-points

http://static.nautil.us/7946_5d188b044333b4c62676e0d4f53dade7.png

Physical stress can operate in unexpected ways. For example, it takes more pressure to shoot a cork from a bottle of champagne than to raze a concrete building. If that seems counterintuitive, keep in mind that you don’t need a lot of pressure to generate significant force. After all, the same amount of wind pressure that barely rustles your clothes can propel a yacht. That’s because pressure measures a force’s intensity across a given surface area: The more area you put under pressure, the more force you get. 
Here are the magnitudes of pressure, in pascals, it takes to ...Move the ball to see what breaks when. Conor Myhrvold writes about science, technology, and nature. His other work has appeared in Nature, Scientific American, MIT Technology Review, Ars Technica, and Fast Company (...)

Now You Can « Hear » Climate Change - Scientific American
▻http://blogs.scientificamerican.com/observations/now-you-can-hear-climate-change-video
▻https://vimeo.com/127083533

each instrument represents a region of the hemisphere. The cello plays the data from the equatorial zone, the viola the mid-latitudes, one violin the high latitudes and another violin the Arctic. The pitch of each note represents the average annual temperature of the region for the relevant year. For example, a high note on the violin means warm weather in the Arctic; a low note on the cello means cold weather along the equator. Blend all four, and you can hear how temperatures fluctuate across the hemisphere and how much they have risen.

#visualisation ou plutôt #sonification du #climat