publishedmedium:the journal nature

  • Maps that show travel times to cities all across the globe

    An international team of researchers, including a representative from Google, has created a color-coded map of the planet that shows travel times to cities from other places. In their paper published in the journal Nature, the group describes how they gathered their data and used it to plot their maps, and also discuss some things they found interesting in the maps they created.

    Back in 2000, a group of researchers attempted to create the first map of the world that would reveal the distances people would have to travel to get to a city—but according to the team working on this new effort note, that was before the advent of modern infrastructure computer networks. Building such maps is important because it shows how well countries are doing in meeting the needs of their people. Cities offer services that simply cannot be matched in the wilderness, in a big jungle or in villages located on sparse desert landscapes.

    #cartographie #chronocartographie #visualisation #sémiologie

  • Earth has more trees now than 35 years ago

    Despite ongoing deforestation, fires, drought-induced die-offs, and insect outbreaks, the world’s tree cover actually increased by 2.24 million square kilometers — an area the size of Texas and Alaska combined — over the past 35 years, finds a paper published in the journal Nature. But the research also confirms large-scale loss of the planet’s most biodiverse ecosystems, especially tropical forests.


  • A new study on increased snowfall in Antarctica shows the dramatic pace of climate change — Quartz

    It may sound odd to hear news of more snow during a time when scientists keep uncovering more evidence that polar ice caps are melting, raising sea levels around the world. But it makes sense, and it’s not a good sign for the Earth. Warmer temperatures mean more moisture in the air, which creates better conditions for snow over Antarctica. So really, this is a sign of the same climate problems causing droughts, storms, and floods.

    The findings may help answer a question scientists have had about the impact of snowfall on rapid climate change. Plainly put, would more snowfall in Antarctica slow the rise of sea levels by trapping water in the form of snow? The answer: Probably not. A 2012 study published in the journal Nature suggested more snow correlated with an increase in the rate at which ice breaks and floats away.

    #climat #neige #antarctique

  • Hubble finds planet with glowing water atmosphere | BBC Sky at Night Magazine

    Scientists have discovered the strongest evidence to date for a stratosphere, a mid-level layer of atmosphere in which temperature increases with altitude, on a planet outside our Solar System, or exoplanet.

    The stratosphere was found around a hot Jupiter exoplanet, WASP-121b, using data taken by the Hubble Space Telescope.

    With a mass 1.2 times that of Jupiter and a radius about 1.9 times Jupiter’s, Hubble discovered that WASP-121b had high temperatures in its stratosphere relative to its lower atmosphere.

    This result is exciting because it shows that a common trait of most of the atmospheres in our solar system – a warm stratosphere – also can be found in exoplanet atmospheres,” said Mark Marley, study co-author based at NASA’s Ames Research Center.

    Reporting in the journal Nature, scientists were also able to determine that the exoplanet has an orbital period of a mere 1.3 days. This exoplanet is so close to its star that its outer atmosphere is heated to a blazing 2,500 °C, hot enough to boil lead.

    This super-hot exoplanet is going to be a benchmark for our atmospheric models,” said Hannah Wakeford, study co-author who worked on this research while at NASA’s Goddard Space Flight Center.

    • An ultrahot gas-giant exoplanet with a stratosphere : Nature : Nature Research

      Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere. If upper layers are cooler than lower layers, molecular gases will produce absorption features in the planetary thermal spectrum. Conversely, if there is a stratosphere—where temperature increases with altitude—these molecular features will be observed in emission. It has been suggested that stratospheres could form in highly irradiated exoplanets, but the extent to which this occurs is unresolved both theoretically and observationally. A previous claim for the presence of a stratosphere remains open to question, owing to the challenges posed by the highly variable host star and the low spectral resolution of the measurements. Here we report a near-infrared thermal spectrum for the ultrahot gas giant WASP-121b, which has an equilibrium temperature of approximately 2,500 kelvin. Water is resolved in emission, providing a detection of an exoplanet stratosphere at 5σ confidence. These observations imply that a substantial fraction of incident stellar radiation is retained at high altitudes in the atmosphere, possibly by absorbing chemical species such as gaseous vanadium oxide and titanium oxide.

  • Earth probably began with a solid shell

    The research, described in a paper published in the journal Nature, is the latest salvo in a long-standing debate in the geological research community: did plate tectonics start right away—a theory known as uniformitarianism—or did Earth first go through a long phase with a solid shell covering the entire planet? The new results suggest the solid shell model is closest to what really happened.

    #terre #tectonique_des_plaques

  • Imaging tiny #comet #dust in 3D

    Rosetta has imaged the smallest grains of #Comet_67P/Churyumov-Gerasimenko’s dust yet, with its Micro-Imaging Dust Analysis System, MIDAS. MIDAS works by collecting and then physically scanning grains with an Atomic Force Microscope. This uses a very fine tip, a bit like an old-fashioned record player needle, that is scanned over a particle. The deflection of the needle and therefore the height of the sample are measured to build up a 3D picture. This enables scientists to determine the structure of the particle, and thus gain insight into how it might have formed. The new results, published in the journal Nature, provide evidence that dust particles continue to be aggregates below the size range already reported by the COSIMA instrument. That is, even at the very small scales of a few (...)

    #Comets #Images #Instruments #Rosetta #coma #instruments #rosetta #science

  • Study finds climate change will reshape global economy

    Unmitigated climate change is likely to reduce the income of an average person on Earth by roughly 23 percent in 2100, according to estimates contained in research published today in the journal Nature that is co-authored by two University of California, Berkeley professors.

    #climat #changement_climatique #économie

  • Blood Brothers: Palestinians and Jews Share Genetic Roots - Israel News - Haaretz Israeli News Source

    Jews break down into three genetic groups, all of which have Middle Eastern origins – which are shared with the Palestinians and Druze.
    Josie Glausiusz Oct 20, 2015 2:38 PM

    Confronted by the violence sweeping over Israel, it can be easy to overlook the things that Jews and Palestinians share: a deep attachment to the same sliver of contested land, a shared appetite for hummus, a common tradition of descent from the patriarch Abraham, and, as scientific research shows - a common genetic ancestry, as well.

    Several major studies published in the past five years attest to these ancient hereditary links. At the forefront of these efforts are two researchers: Harry Ostrer, professor of pediatrics and pathology at Albert Einstein College of Medicine in the Bronx, New York, and Karl Skorecki, director of medical and research development at the Rambam Health Care Campus in Haifa. Back in June 2010, and within two days of each other, the two scientists and their research teams published extensive analyses of the genetic origins of the Jewish people and their Near East ancestry.
    “The closest genetic neighbors to most Jewish groups were the Palestinians, Israeli Bedouins, and Druze in addition to the Southern Europeans, including Cypriots,” as Ostrer and Skorecki wrote in a review of their findings that they co-authored in the journal Human Genetics in October 2012.
    “Karl and I are good friends,” Ostrer told Haaretz by telephone from New York. “We used somewhat different analytical methods—there’s no claim there for superiority, or one side versus the other.” In their results, as well, “there was really very little difference at all.”
    Ostrer’s research on “Abraham’s Children in the Genome Era,” published in The American Journal of Human Genetics, sampled 652,000 gene variants from each of 237 unrelated individuals from seven Jewish populations: Iranian, Iraqi, Syrian, Italian, Turkish, Greek and Ashkenazi. These sequences were then compared with reference samples from non-Jews drawn from The Human Genome Diversity Project, a global database of genetic information gathered from populations across the world.
    Each of the Jewish populations, they found, “formed its own distinctive cluster,” indicating their shared ancestry and “relative genetic isolation.”
    Ostrer’s team also identified two major groups of Jews: Middle Eastern Jews (Iranian and Iraqi) and European/Syrian Jews. The split between these two groups of Jews occurred some 2,500 years ago.
    Cousins with the Druze and French
    Both groups of Jews shared ancestry with contemporary Middle Eastern and Southern European populations. The closest genetic relatives of the Middle Eastern Jews are Druze, Bedouin and Palestinians. The closest genetic relatives of the European group of Jews are Northern Italians, followed by Sardinians and French.
    In a 2012 study, Ostrer identified North African Jews as a third major group. In Skorecki’s study on the genome-wide structure of the Jewish people, published in the journal Nature, he and his fellow researchers sampled tens of thousands of genetic variants from the genomes of 121 individuals hailing from 14 Jewish Diaspora communities, and compared these variants with samples drawn from 1,166 individuals from 69 Old World non-Jewish populations.
    They found that Jews from the Caucasus (Azerbaijan and Georgia), the Middle East (Iran and Iraq) North Africa (Morocco) and Sephardi and Ashkenazi communities, as well as Samaritans, form a “tight cluster” that overlaps with Israeli Druze.
    This, the authors write, “is consistent with an ancestral Levantine contribution to much of contemporary Jewry.”
    In addition, a “compact cluster” of Yemenite Jews “overlaps primarily with Bedouins but also with Saudi individuals.” Ethiopian and Indian Jews are more closely related to their own neighboring, host populations.
    Middle East origins in European Jews
    Further evidence for the Middle Eastern origins of Ashjenazi Jews came from a study published in 2014: In that research, which appeared in Nature Communications, a team led by Shai Carmi of the Hebrew University of Jerusalem sequenced the complete genomes of 128 people of Ashkenazi Jewish ancestry. Their analysis revealed that the Ashkenazi Jewish population is “an even mix” of European and Middle Eastern ancestral populations—suggesting, as Carmi writes on the web site of The Ashkenazi Genome Consortium (TAGC), “a sex-biased process, where, say, Middle-Eastern Jewish men married European non-Jewish women.”
    Are these genetic ties between Jews, Palestinians, Bedouin, and Druze important in a contemporary context? “It doesn’t matter to me personally,” Skorecki says, “since I think that global human identity supersedes all other considerations.”
    “We want to know who we are and where we came from,” Ostrer, who is now studying cancer risks among Ashkenazi Jews and Northern Israeli Druze populations, sums up. Even so, shared ancestry doesn’t necessarily imply a special bond. As Ostrer notes, citing the Biblical tale of Cain and Abel, “the fact that people are related to one another doesn’t prevent their developing extreme hostility to one another.”

    Josie Glausiusz
    Haaretz Contributor

  • #comet sinkholes generate jets

    This story is mirrored from the main ESA web portal and is based on a paper just published in the journal Nature. A number of the dust jets emerging from #Rosetta’s comet can be traced back to active pits that were likely formed by a sudden collapse of the surface. These ‘sinkholes’ are providing a glimpse at the chaotic and diverse interior of the comet. #rosetta has been monitoring #Comet_67P/Churyumov–Gerasimenko’s activity for over a year, watching how its halo of dust and gas grows as the comet moves closer to the Sun along its orbit. From a distance of a few hundred kilometres, Rosetta observes an intricate pattern of the dust jets emitted from the nucleus as they stream out into space. But now, thanks to high-resolution #Images from the OSIRIS camera from distances of just 10–30 km from (...)

    #Comets #Instruments #Science #instruments #science

  • Brain-immune system connection lymphatic vessel - Business Insider

    Antoine Louveau was looking through his microscope at thin membranes that protect the brain when he saw something that absolutely shouldn’t be there: a lymphatic vessel.


    Experts greeted the resulting study, published Monday in the journal Nature, with a mixture of excitement and caution. The main hurdles: Other researchers must replicate the work and confirm the vessel exists in humans, since the study primarily examined mouse brains.

    #anatomie #physiologie #cerveau

  • Europe’s Languages Were Carried From the East, DNA Shows
    The new settlers, revealed by a genetic analysis, may solve a mystery swirling around the origins of Indo-European languages.

    New DNA evidence suggests that herders from the grasslands of today’s Russia and Ukraine carried the roots of modern European languages across the continent some 4,500 years ago.

    The introduction of farming has often been described as the pivotal event in European prehistory. The new study, published Monday in the journal Nature, suggests that instead of one mass migration of farmers, as long thought, there were two: first an influx from Anatolia, a region of today’s Turkey, and then a second wave of people moving into central Europe from the steppes of modern-day Russia, four millennia later, who would have brought with them the Indo-European languages that became English and many other modern European languages.

    Le contenu de l’article est (un peu) plus subtil que l’équation ADN = langage du titre. De même le titre de l’article original de Nature, tout aussi affirmatif, la conclusion du résumé l’étant (un peu) moins.

    Massive migration from the steppe was a source for Indo-European languages in Europe (39 signatories)

    We generated genome-wide data from 69 Europeans who lived between 8,000–3,000 years ago by enriching ancient DNA libraries for a target set of almost 400,000 polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of Western and Far Eastern Europe followed opposite trajectories between 8,000–5,000 years ago. At the beginning of the Neolithic period in Europe, ~8,000–7,000 years ago, closely related groups of early farmers appeared in Germany, Hungary and Spain, different from indigenous hunter-gatherers, whereas Russia was inhabited by a distinctive population of hunter-gatherers with high affinity to a ~24,000-year-old Siberian. By ~6,000–5,000 years ago, farmers throughout much of Europe had more hunter-gatherer ancestry than their predecessors, but in Russia, the Yamnaya steppe herders of this time were descended not only from the preceding eastern European hunter-gatherers, but also from a population of Near Eastern ancestry. Western and Eastern Europe came into contact ~4,500 years ago, as the Late Neolithic Corded Ware people from Germany traced ~75% of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least ~3,000 years ago, and is ubiquitous in present-day Europeans. These results provide support for a steppe origin of at least some of the Indo-European languages of Europe.

    Plein de graphiques, dont

    a, Geographic location and time-scale (central European chronology) of the 69 newly analysed ancient individuals from this study (black outline) and 25 from the literature for which shotgun sequencing data was available (no outline).
    b, Number of SNPs covered at least once in the analysis data set of 94 individuals.

    Le résumé cartographique des hypothèses

    a, Proposed routes of migration by early farmers into Europe ~9,000−7000 years ago.
    b, Resurgence of hunter-gatherer ancestry during the Middle Neolithic 7,000−5,000 years ago.
    c, Arrival of steppe ancestry in central Europe during the Late Neolithic ~4,500 years ago. White arrows indicate the two possible scenarios of the arrival of Indo-European language groups. Symbols of samples are identical to those in Fig. 1.

  • COSIMA watches #comet shed its dusty coat

    Early results from #rosetta's COmetary Secondary Ion Mass Analyser (COSIMA) are published today in the journal Nature. The study covers August to October, when the comet moved along its orbit between about 535 million kilometres to 450 million kilometres from the Sun, and when Rosetta was orbiting the comet at distances of 30 km or less. This news item is also published on the ESA Portal. COSIMA is one of Rosetta’s three dust analysis experiments. It started collecting, imaging and measuring the composition of dust particles shortly after the spacecraft arrived at the comet in August 2014. The scientists looked at the way that many large dust grains broke apart when they were collected on the instrument’s target plate, typically at low speeds of 1–10 m/s. The grains, which were originally at (...)

    #Comet_67P #Comets #Images #Instruments #Science #instruments #science

  • From a Pile of Dirt, Hope for a Powerful New Antibiotic

    The method, which extracts drugs from bacteria that live in dirt, has yielded a powerful new antibiotic, researchers reported in the journal Nature on Wednesday. The new drug, teixobactin, was tested in mice and easily cured severe infections, with no side effects.

    Better still, the researchers said, the drug works in a way that makes it very unlikely that bacteria will become resistant to it. And the method developed to produce the drug has the potential to unlock a trove of natural compounds to fight infections and cancer — molecules that were previously beyond scientists’ reach because the microbes that produce them could not be grown in the laboratory.

    Teixobactin has not yet been tested in humans, so its safety and effectiveness are not known. Studies in people will not begin for about two years, according to Kim Lewis, the senior author of the article and director of the Antimicrobial Discovery Center at Northeastern University in Boston. Those studies will take several years, so even if the drug passes all the required tests, it still will not be available for five or six years, he said during a telephone news conference on Tuesday. If it is approved, he said, it will probably have to be injected, not taken by mouth.


    The new research is based on the premise that everything on earth — plants, soil, people, animals — is teeming with microbes that compete fiercely to survive. Trying to keep one another in check, the microbes secrete biological weapons: antibiotics.

    “The way bacteria multiply, if there weren’t natural mechanisms to limit their growth, they would have covered the planet and eaten us all eons ago,” Dr. Schaffner said.

    Scientists and drug companies have for decades exploited the microbes’ natural arsenal, often by mining soil samples, and discovered lifesaving antibiotics like penicillin, streptomycin and tetracycline, as well as some powerful chemotherapy drugs for cancer. But disease-causing organisms have become resistant to many existing drugs, and there has been a major obstacle to finding replacements, Dr. Lewis said: About 99 percent of the microbial species in the environment are bacteria that do not grow under usual laboratory conditions.

    Dr. Lewis and his colleagues found a way to grow them. The process involves diluting a soil sample — the one that yielded teixobactin came from “a grassy field in Maine” — and placing it on specialized equipment. Then, the secret to success is putting the equipment into a box full of the same soil that the sample came from.

    “Essentially, we’re tricking the bacteria,” Dr. Lewis said. Back in their native dirt, they divide and grow into colonies. Once the colonies form, Dr. Lewis said, the bacteria are “domesticated,” and researchers can scoop them up and start growing them in petri dishes in the laboratory.

    The research was paid for by the National Institutes of Health and the German government (some co-authors work at the University of Bonn). Northeastern University holds a patent on the method of producing drugs and licensed the patent to a private company, NovoBiotic Pharmaceuticals, in Cambridge, Mass., which owns the rights to any compounds produced. Dr. Lewis is a paid consultant to the company.

    #santé #antibiotiques #bactéries #cancer #argent #public #privé

    • Un nouvel antibiotique enthousiasme le monde de la recherche :

      Depuis le début des années 2000, de nombreuses équipes de par le monde expérimentent de nouveaux facteurs de croissance sur ces bactéries. Ces dernières années, plusieurs protocoles favorisant la sécrétion de molécules efficaces contre le développement de diverses bactéries(1) ont été publiés dans la littérature scientifique.

      Rétrospectivement, l’avancée la plus significative dans ce domaine de recherche se révèle être la description, en 2010, d’un dispositif de culture du nom d’#iChip.

      Imaginé par des chercheurs de la Northeastern University de Boston, cet iChip consiste en une superposition de petites plaques de plastique hydrophobe, le tout percé de trous. Les bactéries sont ensuite introduites dans les trous de la plaque supérieure, avec quelques éléments nutritifs.

      L’ensemble est enfin mis en incubation dans l’environnement naturel des bactéries. Celles-ci se multiplient alors rapidement, en colonisant les niches des plaques inférieures. Les biologistes peuvent alors recueillir les cultures, plaque par plaque.

      Une équipe de biologistes étasuniens, allemands et britanniques ont utilisé l’iChip pour cultiver des milliers de bactéries méconnues.

    • Espoir avec la découverte d’un nouvel antibiotique

      La mise au point d’antibiotiques a reposé jusqu’ici sur l’identification de substances produites naturellement par des micro-organismes présents dans le sol. Ces substances permettent de se défendre contre des bactéries. La pénicilline est ainsi à l’origine fabriquée par une moisissure. Les substances naturelles présentent l’avantage d’être le fruit d’une longue évolution qui leur permet de pénétrer dans les bactéries ciblées bien mieux que des produits de synthèse.

      Mais la contrainte est qu’il était nécessaire de se limiter aux micro-organismes cultivables en laboratoire. Or « on avait fait le tour des composés obtenus par ce procédé susceptibles d’avoir une activité antibiotique », constate le professeur Jean-Michel Molina, chef du service des maladies infectieuses à l’hôpital Saint-Louis, à Paris. C’est précisément là que l’équipe américano-allemande a réalisé une percée, grâce à l’utilisation d’un dispositif miniaturisé très innovant, l’iChip : une puce multicanaux.

  • The Coming Plague

    UXBRIDGE, Canada, Oct 10 2013 (IPS) - A climate plague affecting every living thing will likely start in 2020 in southern Indonesia, scientists warned Wednesday in the journal Nature. A few years later the plague will have spread throughout the world’s tropical regions.

    By mid-century no place on the planet will be unaffected, said the authors of the landmark study.

  • #H5N1 controversy: Studies must go on, says scientist

    Despite declaring last week a 60-day moratorium on the studies to allay security fears, Yoshihiro Kawaoka argued in a commentary in the journal Nature it was urgent and vital that his work continue. (...)
    Last week, the two teams - Kawaoka’s and a second team led by Ron Fouchier at Erasmus Medical College in the Netherlands - said they would temporarily suspend their research because of the concerns. 
    But writing in Nature on Wednesday, Kawaoka argued it would be “irresponsible” and dangerous not to continue researching highly pathogenic bird flu viruses.