• Genomes reveal start of Ebola outbreak

    http://www.sciencemag.org/content/345/6200/989.full

    When the young woman arrived at the Kenema Government Hospital in Sierra Leone in late May, she had high fever and had just miscarried. The hospital suspected she had contracted Lassa fever, because the viral disease is endemic in the region and often causes miscarriages. But Ebola virus disease, another hemorrhagic fever illness, had been spreading in neighboring Guinea for months, so when she began bleeding profusely, staff tested her for that virus as well. The results were positive, making her the first confirmed case of Ebola in Sierra Leone.

    The young woman, who eventually recovered, is now at the heart of a tragic but potentially important research tale. In a paper online this week in Science, a collaboration led by Stephen Gire and Pardis Sabeti of Harvard University and the Broad Institute in Cambridge, Massachusetts, report sequencing and analyzing the genomes of Ebola virus samples from 78 people in Sierra Leone who were diagnosed with Ebola between late May and mid-June, including the young woman who came to Kenema’s hospital. The 99 complete sequences—some patients were sampled more than once—provide insights into how the virus is changing during the outbreak, which could help improve current diagnostic tests and, in the long term, guide researchers working on vaccines and treatments.

    #ebola

  • Study: Left alone with their thoughts, people choose electric shock
    http://www.latimes.com/science/sciencenow/la-sci-sn-people-alone-thoughts-mind-dislike-electric-shocks-20140703-story

    “But what is striking is that simply being alone with their own thoughts for 15 minutes was apparently so aversive that it drove many participants to self-administer an electric shock that they had earlier said they would pay to avoid."

    Just think: The challenges of the disengaged mind
    http://www.sciencemag.org/content/345/6192/75.abstract
    #concentration #solitude

    • Le résumé de l’article de Science

      Varying planetary heat sink led to global-warming slowdown and acceleration
      http://www.sciencemag.org/content/345/6199/897.abstract

      A vacillating global heat sink at intermediate ocean depths is associated with different climate regimes of surface warming under anthropogenic forcing: The latter part of the 20th century saw rapid global warming as more heat stayed near the surface. In the 21st century, surface warming slowed as more heat moved into deeper oceans. In situ and reanalyzed data are used to trace the pathways of ocean heat uptake. In addition to the shallow La Niña–like patterns in the Pacific that were the previous focus, we found that the slowdown is mainly caused by heat transported to deeper layers in the Atlantic and the Southern oceans, initiated by a recurrent salinity anomaly in the subpolar North Atlantic. Cooling periods associated with the latter deeper heat-sequestration mechanism historically lasted 20 to 35 years.

      Une visualisation du stockage d’énergie


      illustrant cette courte présentation

      Earth’s missing heat may be hiding in the deep Atlantic | Science/AAAS | News
      http://news.sciencemag.org/climate/2014/08/earths-missing-heat-may-be-hiding-deep-atlantic

      The work draws on tens of millions of ocean temperature and salinity measurements taken globally by buoys, floats, and ships since 1970. Covering 24 depths from the sea surface down to 1500 meters, the data suggest that over the last decade or so the Atlantic has been absorbing heat (red in the graphic above) that would have otherwise warmed the surface. Over the past 14 years, the authors write, water below 300 meters in the North and South Atlantic oceans has stored more energy than the rest of the global oceans combined.

      L’édito de Science sur le sujet qui remet en contexte, présente les autres hypothèses sur le rôle de la circulation océanique et rappelle qu’il ne s’agit que d’une pause apparente, puisque l’accumulation de chaleur se poursuit, mais hors de notre vue.

      Pas sûr que cela suffise à neutraliser les climato-sceptiques…

      Is Atlantic holding Earth’s missing heat ?
      http://www.sciencemag.org/content/345/6199/860.summary

      Armchair detectives might call it the case of Earth’s missing heat: Why have average global surface air temperatures remained essentially steady since 2000, even as greenhouse gases have continued to accumulate in the atmosphere? The suspects include changes in atmospheric water vapor, a strong greenhouse gas, or the noxious sunshade of haze emanating from factories. Others believe the culprit is the mighty Pacific Ocean, which has been sending vast slugs of cold bottom water to the surface. But two fresh investigations finger a new suspect: the Atlantic Ocean. One study, in this issue of Science, presents sea temperature data implying that most of the missing heat has been stored deep in the Atlantic. The other, published online in Nature Climate Change, suggests a warming Atlantic is abetting the Pacific by driving wind patterns that help that ocean cool the atmosphere. But some climate specialists remain skeptical. In a third recent paper, also published online in Nature Climate Change, other researchers argue that the Pacific remains the kingpin. One reason some scientists remain convinced the Pacific is behind the hiatus is a measured speedup in trade winds that drive a massive upwelling of cold water in the eastern Pacific. But there, too, the Atlantic may be responsible, modeling experiments suggest. A consensus about what has put global warming on pause may be years away, but one scientist says the recent papers confirm that Earth’s warming has continued during the hiatus, at least in the ocean depths, if not in the air.

  • An Infographic That Maps 2,000 Years of Cultural History in 5 Minutes | Design | WIRED

    http://www.wired.com/2014/08/an-infographic-that-maps-2600-years-of-cultural-history-in-5-minutes

    Fascinant. On se demande quoi faire en cartographie après avoir vu ça...

    https://www.youtube.com/watch?v=4gIhRkCcD4U

    Ah, Hollywood. Our glowing beacon of modern hope and dreams. But before Hollywood, there was New York, and before New York there was Berlin, Paris, Rome and Greece. History’s most creative people have always flocked to cultural and intellectual hubs, and now, thanks to an amazing visualization from researchers at the University of Texas at Dallas, we can see how that migration has changed over time.

    Last week in the journal Science, the researchers (led by University of Texas at Dallas art historian Maximilian Schich) published a study that looked at the cultural history of Europe and North America by mapping the birth and deaths of more than 150,000 notable figures—including everyone from Leonardo Da Vinci to Ernest Hemingway. That data was turned into an amazing animated infographic that looks strikingly similar to the illustrated flight paths you find in the back of your inflight magazine. Blue dots indicate a birth, red ones means death.

    #cartographie #visualisation #culture #cartographie_animée

  • Plus d’humains, moins d’invertébrés
    http://www.lapresse.ca/actualites/sciences/201407/24/01-4786524-plus-dhumains-moins-dinvertebres.php

    Face au quasi-doublement du nombre d’êtres humains sur la Terre depuis 40 ans, le nombre d’#insectes, de vers et de crustacés a baissé de 45%, estiment des chercheurs dans une étude parue jeudi dans la revue Science.

    Les invertébrés —tous les #animaux qui ne possèdent pas de colonne vertébrale— sont des êtres indispensables à la Terre : ils pollinisent les cultures, réduisent les insectes nuisibles, filtrent l’eau et nourrissent le sol de nutriments.

    Les chercheurs estiment que 322 espèces de vertébrés ont disparu dans les cinq derniers siècles. Les espèces restantes comptent en outre 25% d’individus en moins.

    « Nous avons été très surpris de découvrir que les pertes chez les invertébrés étaient similaires à celles d’animaux plus grands, car nous pensions jusqu’à présent que les invertébrés étaient plus résistants », a expliqué Ben Collen, de l’University College London, coauteur de l’étude.

    Deux facteurs contribuent à la disparition des invertébrés, selon les chercheurs : la perte d’habitat et le #changement_climatique.

    Une autre étude publiée dans le même numéro de Science décrit un rapport de cause à effet entre la disparition d’espèces animales et l’augmentation des #conflits, du crime organisé et de l’exploitation des enfants à l’échelle mondiale.

    La destruction d’emplois et la pénurie alimentaire pourraient provoquer directement une hausse du trafic d’êtres humains, selon cette étude menée par des chercheurs de l’Université de Californie à Berkeley.

    « Cet article décrit le déclin de la faune comme une source, et non un symptôme, de conflits sociaux », explique l’auteur principal, le professeur Justin Brashares.

    « Des milliards de gens dépendent directement et indirectement des ressources sauvages de viande pour leurs revenus et leur subsistance, et cette ressource diminue », dit-il.

    À titre d’exemples, le chercheur relève que les activités de piraterie au large de la Somalie ont pour origine un conflit sur les droits de pêche.

    Les deux papiers :
    Defaunation in the #Anthropocene
    http://www.sciencemag.org/content/345/6195/401
    Wildlife decline and social conflict
    http://www.sciencemag.org/content/345/6195/376

    #biodiversité