Últimas noticias de Ciencias

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  1. CROTOCULTURA Avatar de Gerli
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    Re: Últimas noticias de Ciencias

    Lo interesante del Antropoceno es que no solo van a dar una fecha estimada; hasta pueden dar un dia y hora exactos (Suponiendo de la clase de evento que se elija como "punta")
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  2. Alt+C4 Avatar de 9up!
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    First test of Breakthrough Starshot interstellar probe highlights likely damage due to gas and dust

    >A small team of researchers at Harvard University who are part of the Breakthrough Starshot team has been testing the likely damage to an interstellar spacecraft traveling at approximately one-fifth the speed of light as it makes its way to the Alpha Centauri star system. As they note in a paper describing their testing and results, which was uploaded to the*arXiv*preprint server, such damage could be catastrophic, but they believe they have a solution.

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    Vamos a ver si llegan antes de que me muera.
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

  3. Alt+C4 Avatar de 9up!
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    Scientists discover a 'dark' Milky Way: Massive galaxy consists almost entirely of dark matter

    Using the world's most powerful telescopes, an international team of astronomers has found a massive galaxy that consists almost entirely of dark matter.

    The galaxy, Dragonfly 44, is located in the nearby Coma constellation and had been overlooked until last year because of its unusual composition: It is a diffuse "blob" about the size of the Milky Way, but with far fewer stars.

    "Very soon after its discovery, we realized this galaxy had to be more than meets the eye. It has so few stars that it would quickly be ripped apart unless something was holding it together," said Yale University astronomer Pieter van Dokkum, lead author of a paper in theAstrophysical Journal Letters.

    Van Dokkum's team was able to get a good look at Dragonfly 44 thanks to the W.M. Keck Observatory and the Gemini North telescope, both in Hawaii. Astronomers used observations from Keck, taken over six nights, to measure the velocities of stars in the galaxy. They used the 8-meter Gemini North telescope to reveal a halo of spherical clusters of stars around the galaxy's core, similar to the halo that surrounds our Milky Way galaxy.

    Star velocities are an indication of the galaxy's mass, the researchers noted. The faster the stars move, the more mass its galaxy will have.

    "Amazingly, the stars move at velocities that are far greater than expected for such a dim galaxy. It means that Dragonfly 44 has a huge amount of unseen mass," said co-author Roberto Abraham of the University of Toronto.

    Scientists initially spotted Dragonfly 44 with the Dragonfly Telephoto Array, a telescope invented and built by van Dokkum and Abraham.

    Dragonfly 44's mass is estimated to be 1 trillion times the mass of the Sun, or 2 tredecillion kilograms (a 2 followed by 42 zeros), which is similar to the mass of the Milky Way. However, only one-hundredth of 1% of that is in the form of stars and "normal" matter. The other 99.99% is in the form of dark matter—a hypothesized material that remains unseen but may make up more than 90% of the universe.

    The researchers note that finding a galaxy composed mainly of dark matter is not new; ultra-faint dwarf galaxies have similar compositions. But those galaxies were roughly 10,000 times less massive than Dragonfly 44.

    "We have no idea how galaxies like Dragonfly 44 could have formed," said Abraham. "The Gemini data show that a relatively large fraction of the stars is in the form of very compact clusters, and that is probably an important clue. But at the moment we're just guessing."

    Van Dokkum, the Sol Goldman Family Professor of Astronomy and Physics at Yale, added: "Ultimately what we really want to learn is what dark matter is. The race is on to find massive dark galaxies that are even closer to us than Dragonfly 44, so we can look for feeble signals that may reveal a dark matter particle."
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

  4. Alt+C4 Avatar de 9up!
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    New find might be oldest evidence of life on Earth

    Fossil evidence goes back about 3.5 billion years, with controversial isotopic signs that*might*signify life about 3.8 billion years ago (or perhaps*even earlier). At this age, you run out of rocks. Although the planet is about 4.5 billion years old, very few rocks have survived for more than 3.5 billion years. The ones that*have*look their age, metamorphosed so much over the eons that signs of life might have been erased.

    Still, the quest to push back the earliest evidence for life goes on. New finds are subject to rigorous debate, and researchers have to work hard to figure out whether a*physical process*could be responsiblefor a feature that has the appearance of a fossil.

    In a newly published paper, a team led by University of Wollongong researcher*Allen Nutman*describes a find from Greenland it thinks represents a 3.7 billion-year-old microbial community. That would push back the earliest fossil evidence by more than 200 million years.

    The find comes from a belt of ancient, metamorphosed sedimentary rocks in southwest Greenland that has long been targeted for this kind of thing. These same rocks are the source of the isotopic signal some have interpreted as indicative of nearly 3.8 billion-year-old life. More of the study area is now accessible, though, because the snow that perpetually blanketed it now melts off in the summer.

    The researchers haven’t found microscopic fossils there, but they have found*macroscopic structures they believe are*stromatolites.*Stromatolites*are small, layered mounds of sediment built by mats of microbes living in shallow water. They’re still found in a few places today and can commonly be found throughout the geologic record due to their distinctive structure of fine, concentric layers. Stromatolites can range in size from a few centimeters across to more than a meter—all of which is significantly easier to spot than a single, fossilized microbe.
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    Turns out the signal astronomers saw was “strong” because it came from Earth

    Of course, you already knew that if you read the skeptical Ars report on Monday.
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

  5. Bela Lugosi Avatar de -Entalpia-
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    Re: Últimas noticias de Ciencias

    No es una noticia pero bueno, me acaban de "compartir" esto en el muro:
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  6. CROTOCULTURA Avatar de Gerli
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    Re: Últimas noticias de Ciencias

    Generalmente respondo a esas imágenes con un "Wow, pobreza en Africa... si no lo compartías jamas me hubiera enterado, seguí así campeón"
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  7. Dog Whisperer. Avatar de Nectar-
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    Re: Últimas noticias de Ciencias

    Ahora compara el gasto de la NASA con el porcentaje destinado a gastos militares en usa y flashea un rato

    ------.--------

    Vieron que quieren estrellar a rosseta contra el 67P/Churyumov–Gerasimenko para obtener mas datos antes de que se alejen mucho del sol y ya no sea funcional + encontraron a philae tirada abajo de la piedra y la foto es super cute


    Spoiler!  philae  


    http://www.theverge.com/2016/6/30/12...eath-scheduled

    En otras noticias, juno empezo a mandar fotos de jupiter y son increibles:



    Y lo ultimo para terminar bien al palo tirando cuete'

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    If you wish to make an apple pie from scratch, you must first invent the universe.

  8. Avatar de Amadeo.
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    Re: Últimas noticias de Ciencias

    Evidence Rebuts Chomsky's Theory of Language Learning

    The idea that we have brains hardwired with a mental template for learning grammar—famously espoused by Noam Chomsky of the Massachusetts Institute of Technology—has dominated linguistics for almost half a century. Recently, though, cognitive scientists and linguists have abandoned Chomsky’s “universal grammar” theory in droves because of new research examining many different languages—and the way young children learn to understand and speak the tongues of their communities. That work fails to support Chomsky’s assertions.

    The research suggests a radically different view, in which learning of a child’s first language does not rely on an innate grammar module. Instead the new research shows that young children use various types of thinking that may not be specific to language at all—such as the ability to classify the world into categories (people or objects, for instance) and to understand the relations among things. These capabilities, coupled with a unique human ability to grasp what others intend to communicate, allow language to happen. The new findings indicate that if researchers truly want to understand how children, and others, learn languages, they need to look outside of Chomsky’s theory for guidance.

    This conclusion is important because the study of language plays a central role in diverse disciplines—from poetry to artificial intelligence to linguistics itself; misguided methods lead to questionable results. Further, language is used by humans in ways no animal can match; if you understand what language is, you comprehend a little bit more about human nature.
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  9. Dog Whisperer. Avatar de Nectar-
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    Re: Últimas noticias de Ciencias

    Yay!

    La nave Rosetta captura materia orgánica en polvo del cometa 67P:


    http://www.europapress.es/ciencia/mi...908134350.html
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    If you wish to make an apple pie from scratch, you must first invent the universe.

  10. Alt+C4 Avatar de 9up!
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    How I learned to stop worrying and love the big $60B NASA rocket

    NASA wanted to show the world (and next president) that it has a coherent plan to use the SLS rocket and Orion spacecraft to put humans on Mars by the end of the 2030s.



    If Congress was really serious about going to Mars, it would fund work needed to enable humans to live for long periods of time in deep space. As just one example, scientists have almost no data on whether the Mars gravity well is enough to sustain human health and performance, and little money has been set aside to develop an artificial gravity system to test the effect of 0.38g on human abilities. After six or nine months of microgravity during transit, what happens if an abort-level emergency occurs soon after the crew’s arrival on the surface of Mars? The answers weren’t going to be found at Mars Day.
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

  11. ¿Y como puedes cam... Avatar de Soul Hunter
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    Re: Últimas noticias de Ciencias

    Citar Mensaje original enviado por -Entalpia- Ver Mensaje
    No es una noticia pero bueno, me acaban de "compartir" esto en el muro:
    La población de Africa se cuadruplico en 60 años, realmente es de las que mas rápido crece gracias a las mejoras en producción de alimentos. Ayudarles a tener mas comida sólo patea el problema para después y hace que sean mas las almas que sufran la miseria. Si no los ayudas a desarrollarse para que, entre otras cosas, se reproduzcan menos no va a haber ayuda que alcance y tarde o temprano se van a cagar de hambre, realmente la caridad es patear el problema para el futuro.
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  12. Alt+C4 Avatar de 9up!
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    Sugar industry bought off scientists, skewed dietary guidelines for decades

    Back in the 1960s, a sugar industry executive wrote fat checks to a group of Harvard researchers so that they’d downplay the links between sugar and heart disease in a prominent medical journal—and the researchers did it, according to historical documents reported Monday in the journal JAMA Internal Medicine.

    One of those Harvard researchers went on to become the head of nutrition at the United States Department of Agriculture, where he set the stage for the federal government’s current dietary guidelines. All in all, the corrupted researchers and skewed scientific literature successfully helped draw attention away from the health risks of sweets and shift the blame solely to fats—for nearly five decades. The low-fat, high-sugar diets that health experts subsequently encouraged are now seen as a main driver of the current obesity epidemic.

    […]

    By 1965, the SRF funded “Project 226,” which would have Hegsted and McGandy—supervised by Stare—write a literature review that downplayed sugars’ role in heart disease and shifted blame solely to saturated fat. In return the researchers received a total of $6,500—the 2016 equivalent of $48,900.
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

  13. Avatar de ArzenaTh
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    Cuanto más pasa el tiempo, peor parado queda el azúcar

    /tapa
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    Does anybody remember laughter?

  14. Avatar de CibGKs
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    Polémico. Igual sigue en veremos.

    http://neurosciencenews.com/neural-c...cannabis-5020/

    This group had discovered that other areas of the cerebral cortex had a rule called spike timing-dependent plasticity (STDP), that is, the synaptic strength was determined in order of firing of presynaptic and postsynaptic cells, and that this rule suddenly changed in one process during circuit formation. For this reason, this group focused on the possibility that the rule would suddenly change at thalamocortical synapses as they performed their research.

    As a result, when thalamocortical projections were formed, first, synaptic connections were strengthened due to activities in presynaptic and postsynaptic cells, and projections extended over wide areas, but following that, the rule changed so that the synchronized activities weakened the synaptic connections, and extra projections were pruned. In addition, it was found that at the time of weakening of synaptic connections, cannabinoid was released from neural cells via synchronized activities, thereby retracting unnecessary neuron projections. Research showed that neuron projections retracted when cannabinoid was externally taken as well. Furthermore, it was also found that projections remained disorderly in cannabinoid receptors (CB1Rs) knock-out mice.

    This group’s achievement clarified scientific grounds that cannabis and intoxicating drugs had adverse effects on the brain. By disabling the functions of cannabinoid, it may be possible to suppress the breakdown of neural circuits. It is expected that this group’s achievement will be used for recovering functions impaired by brain damage and dementia.
    Paper: "Developmental Switch in Spike Timing-Dependent Plasticity and Cannabinoid-Dependent Reorganization of the Thalamocortical Projection in the Barrel Cortex".
    Abstract:
    Spoiler!  

    The formation and refinement of thalamocortical axons (TCAs) is an activity-dependent process (Katz and Shatz, 1996), but its mechanism and nature of activity are elusive. We studied the role of spike timing-dependent plasticity (STDP) in TCA formation and refinement in mice. At birth (postnatal day 0, P0), TCAs invade the cortical plate, from which layers 4 (L4) and L2/3 differentiate at P3-P4. A portion of TCAs transiently reach toward the pia surface around P2-P4 (Senft and Woolsey, 1991; Rebsam et al., 2002) but are eventually confined below the border between L2/3 and L4. We previously showed that L4-L2/3 synapses exhibit STDP with only potentiation (timing-dependent long-term potentiation [t-LTP]) during synapse formation, then switch to a Hebbian form of STDP. Here we show that TCA-cortical plate synapses exhibit robust t-LTP in neonates, whose magnitude decreased gradually after P4-P5. After L2/3 is differentiated, TCA-L2/3 gradually switched to STDP with only depression (t-LTD) after P7-P8, whereas TCA-L4 lost STDP. t-LTP was dependent on NMDA receptor and PKA, whereas t-LTD was mediated by Type 1 cannabinoid receptors (CB1Rs) probably located at TCA terminals, revealed by global and cortical excitatory cell-specific knock-out of CB1R. Moreover, we found that administration of CB1R agonists, including Δ9-tetrahydrocannabinol, caused substantial retraction of TCAs. Consistent with this, individual thalamocortical axons exuberantly innervated L2/3 at P12 in CB1R knock-outs, indicating that endogenous cannabinoid signaling shapes TCA projection. These results suggest that the developmental switch in STDP and associated appearance of CB1R play important roles in the formation and refinement of TCAs.

    SIGNIFICANCE STATEMENT It has been shown that neural activity is required for initial synapse formation of thalamocortical axons with cortical cells, but precisely what sort of activities in presynaptic and postsynaptic cells are required is not yet clear. In addition, how activity is further translated into structural changes is unclear. We show here that the period during which spike timing-dependent long-term potentiation and depression (t-LTP, t-LTD) can be induced closely matches the time course of synapse formation and retraction, respectively, at the thalamocortical synapse. Moreover, administration of cannabinoid agonists, which mimic t-LTD, caused TCA retraction, suggesting that cannabinoids translate physiological changes into morphological consequences.
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    i5-4570, Asus h87-plus, AMD Sapphire 480 Nitro+, Seasonic 520w S12II, 2x4gb Kingston HyperX 1600mhz

  15. Alt+C4 Avatar de 9up!
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    NASA changed all the astrological signs and I’m a crab now

    According to a post on NASASpacePlace, everything we thought we knew about the influence the heavens have over our Earthly lives has been thrown into chaos. NASA has announced that the celestial sphere above us contains not twelve canonical zodiacal constellations, but 13. The heretofore overlooked constellation, Ophiuchus, is purported to guide and command events surrounding humans born between November 29 and December 17—so, if you used to be a Sagittarius, then congratulations: you’ve got a new sign, baby!

    The addition of Ophiuchus—the snake bearer, in case you were wondering—has obvious and far-reaching implications for the entire western Babylonian-derived zodiac calendar. For one thing, squeezing it in means changing the effective dates of all the other signs. According to Yahoo News, the new 13-sign calendar plays out like this:

    Capricorn: January 20-February 16
    Aquarius: February 16-March 11
    Pisces: March 11-April 18
    Aries: April 18-May 13
    Taurus: May 13-June 21
    Gemini: June 21-July 20
    Cancer: July 20-August 10
    Leo: August 10-September 16
    Virgo: September 16-October 30
    Libra: October 30-November 23
    Scorpio: November 23-November 29
    Ophiuchus: November 29-December 17
    Sagittarius: December 17-January 20

    The changes are as sweeping as they are staggering. For example, I woke up this morning firmly believing that I was an outgoing, courageous, independent, generous Leo. However, now I have to come to grips with the fact that I am in fact a stupid, sulky, inconsiderate, pessimistic Cancer. I have gone from lion to crab, and it weighs heavily upon me.
    JAJAJAJA ¡ahora soy de Aries!
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    —How can entropy be reversed?
    —INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.

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