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Messaggi del 11/04/2011
Post n°817 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"Vinitaly.com" VINITALY, +10% I VISITATORI NEI PRIMI TRE GIORNI. GIOVEDI’ E VENERDI’ SALE AL 42% LA QUOTA DEGLI ESTERI.
Verona, 9 aprile 2011 - Doppio record per la 45^ edizione di Vinitaly, con un numero di visitatori nei primi tre giorni di manifestazione in crescita del 10% rispetto al 2010, che a sabato sera raggiungono quota 100.000.
Record di presenze estere nei primi due giorni, con una percentuale di operatori stranieri del 42% sui 53.000 visitatori totali di giovedì e venerdì.
Positivo quindi il trend della fiera, che vede crescere di anno in anno il suo appeal nei confronti dei trader di tutto il mondo, ma soprattutto segnale di fiducia e ottimismo per lo sviluppo commerciale del settore.
Confermata la provenienza di visitatori da oltre 100 Paesi, grazie al lavoro di incoming svolto dall’organizzazione di Vinitaly per portare in fiera delegazioni di operatori e buyer qualificati sia da Paesi tradizionali importatori, sia da quelli emergenti, e grazie al ruolo di Vinitaly in the World nel rafforzare l’attenzione sulla rassegna che si svolge a Verona.
Post n°816 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"ScienceDaily.com"
Newly Merged Black Hole Eagerly Shreds Stars ScienceDaily (Apr. 9, 2011) — A galaxy's core is a busy place, crowded with stars swarming around an enormous black hole. When galaxies collide, it gets even messier as the two black holes spiral toward each other, merging to make an even bigger gravitational monster. Once it is created, the monster goes on a rampage. The merger kicks the black hole into surrounding stars. There it finds a hearty meal, shredding and swallowing stars at a rapid clip. According to new research by Nick Stone and Avi Loeb (Harvard-Smithsonian Center for Astrophysics), upcoming sky surveys might offer astronomers a way to catch a gorging black hole "in the act." Before the merger, as the two black holes whirl around each other, they stir the galactic center like the blade of a blender. Their strong gravity warps space, sending out ripples known as gravitational waves. When the black holes merge, they emit gravitational waves more strongly in one direction. That inequality kicks the black hole in the opposite direction like a rocket engine. "That kick is very important. It can shove the black hole toward stars that otherwise would have been at a safe distance," said Stone. "Essentially, the black hole can go from starving to enjoying an all-you-can-eat buffet," he added. When tidal forces rip a star apart, its remains will spiral around the black hole, smashing and rubbing together, heating up enough to shine in the ultraviolet or X-rays. The black hole will glow as brightly as an exploding star, or supernova, before gradually fading in a distinctive way. Importantly, a wandering, supermassive black hole is expected to swallow many more stars than a black hole in an undisrupted galactic center. A stationary black hole disrupts one star every 100,000 years. In the best-case scenario, a wandering black hole could disrupt a star every decade. This would give astronomers a much better opportunity of spotting these events, particularly with new survey facilities like Pan-STARRS and the Large Synoptic Survey Telescope. Catching the signal from a disrupted star is a good start. However, astronomers really want to combine that information with gravitational wave data from the black hole merger. The Laser Interferometer Space Antenna (LISA), a future mission designed to detect and study gravitational waves, could provide that data. Gravitational wave measurements yield very accurate distances (to better than one part in a hundred, or 1 percent). However, they don't provide precise sky coordinates. A star's tidal disruption will let astronomers pinpoint the galaxy containing the recently merged black-hole binary. By correlating the galaxy's redshift (a change in its light that's caused by the expanding universe) with an accurate distance, astronomers can infer the equation of state of dark energy. In other words, they can learn more about the force that's accelerating cosmic expansion, and which dominates the cosmic mass/energy budget today. "Instead of 'standard candles' like supernovae, the black hole binary would be a 'standard siren.' Using it, we could create the most accurate cosmic 'ruler' possible," stated Loeb. Finding a merged black hole also would allow theorists to explore a new regime of Einstein's general theory of relativity. "We could test general relativity in the regime of strong gravity with unprecedented precision," said Loeb. Their work was published in the March 2011 issue of Monthly Notices of the Royal Astronomical Society. Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
Post n°815 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"ScienceDaily.com"
Ancient Fossils Hold Clues for Predicting Future Climate Change ScienceDaily (Apr. 10, 2011) — By studying fossilized mollusks from some 3.5 million years ago, UCLA geoscientists and colleagues have been able to construct an ancient climate record that holds clues about the long-term effects of Earth's current levels of atmospheric carbon dioxide, a key contributor to global climate change. Two novel geochemical techniques used to determine the temperature at which the mollusk shells were formed suggest that summertime Arctic temperatures during the early Pliocene epoch (3.5 million to 4 million years ago) may have been a staggering 18 to 28 degrees Fahrenheit warmer than today. And these ancient fossils, harvested from deep within the Arctic Circle, may have once lived in an environment in which the polar ice cap melted completely during the summer months. "Our data from the early Pliocene, when carbon dioxide levels remained close to modern levels for thousands of years, may indicate how warm the planet will eventually become if carbon dioxide levels are stabilized at the current value of 400 parts per million," said Aradhna Tripati, a UCLA assistant professor in the department of Earth and space sciences and the department of atmospheric and oceanic sciences. The results of this study lend support to assertions made by climate modelers that summertime sea ice may be eliminated in the next 50 to 100 years, which would have far-reaching consequences for Earth's climate, she said. The research, federally funded by the National Science Foundation, is scheduled to be published in the April 15 print issue of Earth and Planetary Science Letters. "The Intergovernmental Panel on Climate Change identifies the early Pliocene as the best geological analog for climate change in the 21st century and beyond," said Tripati, who is also a researcher with UCLA's Institute of the Environment and Sustainability and Institute of Geophysics and Planetary Physics. "The climate-modeling community hopes to use the early Pliocene as a benchmark for testing models used for forecasting future climate change." The poles are exhibiting the most warming of any place on the planet, and the effect is most severe in the Arctic, Tripati said. The poles are the first regions on Earth to respond to any global climate change; in some sense, the Arctic serves as the proverbial canary in the coal mine, the first warning sign of fast-approaching danger. Ice sheets and sea ice in polar regions reflect incoming solar radiation to cool Earth -- a phenomenon that makes the poles incredibly sensitive to variations in climate, she said. An increase in Arctic temperatures would not only cause the ice sheets to melt but would also result in the exposed land and ocean absorbing significantly more incoming solar energy and further heating the planet. Without a permanent ice cap in the Arctic, global temperatures in the early Pliocene were 2 to 5 degrees Fahrenheit higher than the current global average. This suggests that the carbon dioxide threshold for maintaining year-round Arctic ice may be well below modern levels, Tripati said. What fossilized shells can tell us about climate The research was conducted on mollusk fossils collected from Beaver Pond, located in the Strathcona Fiord on Ellesmere Island, at northernmost point of Canada, which is well within the Arctic Circle. Named for the numerous branches discovered with beaver teeth marks that have lasted for millions of years, Beaver Pond has proven to be a treasure trove of fossilized plant and animal specimens that remain remarkably well-preserved within a peat layer encased in ice, Tripati said. Climate scientists typically determine ancient temperatures by analyzing the composition of core samples drilled miles into the ice sheets of Greenland or Antarctica. "Ice cores are a remarkable archive of past climate change because they can give us direct insights into how the poles have responded to variations in past greenhouse gas levels," Tripati said. "However, ice core data is available for only the past 800,000 years, during which carbon dioxide levels were never above 280 to 300 parts per million. To understand environmental change for earlier time periods in Earth's history when carbon dioxide levels were near 400 parts per million, we have to rely on other archives." By measuring the isotopic content of oxygen in a combination of fossilized mollusk and plant samples, it is possible to determine the temperature at which the specimens originally formed, Tripati said. While this method enables climate reconstructions dating back millions of years without the need for ice core samples, it is uncommon to find a site that contains both plant and shell specimens from the same time and place. Additionally, Tripati and her co-authors have pioneered a new method for measuring past temperature using only the calcium carbonate found in fossilized shells. Determining how much of the rarest isotopes of carbon and oxygen are present in the mollusk sample yields results consistent with the original method, which required an associated plant specimen. Conclusions drawn from the two techniques used in this study also agree with three entirely different approaches used in a recently published study by several of the co-authors to determine the average temperatures at the same site. Given the consistency among many distinct processes, this new method can be considered a reliable technique for use on samples from a variety of time periods and locations, Tripati said Samples were collected from Beaver Pond by co-author Natalia Rybczynski, a paleobiologist at the Canadian Museum of Nature and adjunct research professor at Carleton University. Adam Csank, a graduate student in the department of geosciences at the University of Arizona, is the first author of the study. Other co-authors include William Patterson, professor of geological sciences at the University of Saskatchewan; Robert Eagle, a postdoctoral scholar at the California Institute of Technology; Ashley Ballantyne, a postdoctoral scholar at the University of Colorado-Boulder; and John Eiler, professor of geological and planetary sciences at the California Institute of Technology.
Post n°814 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"ANSA.it"
Un 'timer' rischio estinzione specie (ANSA) - SYDNEY, 8 APR - Un gruppo di zoologi australiani ha messo a punto un indice, primo del genere al mondo, per determinare quanto siano vicine all'estinzione le specie animali, per prevenirne la scomparsa. Sono state studiate 95 specie di mammiferi dei diversi continenti, concludendo che quasi il 20% e' vicino all'estinzione. Piu' della meta' di queste sono vicine al punto di non ritorno, fra queste il rinoceronte di Giava, l'asino selvatico africano, la lince iberica e il lupo etiope.
Post n°813 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"ANSA.it"
di Enrica Battifoglia
ROMA -Mentre andavano a caccia della ormai celebre ''particella di Dio'', ossia il bosone di Higgs che da' origine alla massa, i fisici del Fermilab di Chicago hanno incontrato qualcosa di completamente inaspettato, una particella misteriosa che ha gia' messo in subbuglio il mondo della ricerca perche' potrebbe essere il primo passo verso la scoperta di leggi fisiche completamente nuove. I ricercatori italiani sono in prima fila: il programma di ricerca Cdf (Collider Detector at Fermilab) e' coordinato dall'italiano Giovanni Punzi e sono 70 i ricercatori dell'Istituto Nazionale di Fisica Nucleare (Infn) coinvolti, sui 520 che stanno lavorando al programma. Provengono dalle sezioni dell'Infn di Roma, Pisa, Trieste, Laboratori Nazionali di Frascati, Bologna, Padova, e dei gruppi di Trento e Siena. ''Sono molto contento come fisico perche', se si tratta di una particella completamente sconosciuta, e' probabile che si tratti di nuova fisica'', ha osservato il presidente dell'Infn, Roberto Petronzio. La strada verso la ''nuova fisica'' promessa dal piu' grande e potente acceleratore del mondo, il Large Hadron Collider (Lhc) del Cern di Ginevra, potrebbe quindi averla aperta il vecchio Tevatron, l'acceleratore del Fermilab pronto ad andare in pensione a fine anno, dopo 23 anni di lavoro. ''La particella e' venuta fuori per caso. Mentre cercavamo eventi relativi al bosone abbiamo visto un tipo di particella che non avrebbe dovuto esserci'', ha detto Punzi. La particella misteriosa e' stata rivelata dalle ''tracce'' che ha lasciato: un bosone W e due ''getti'' di adroni, ossia di particelle composte da due o tre quark che in genere rappresentano la firma del decadimento di una particella pesante. L'annuncio e' arrivato oggi sul sito ''arXiv'' e la pubblicazione e' destinata alla rivista Physical Review Letters. ''La nuova particella la stiamo studiando da un anno, in centinaia, e alla fine abbiamo deciso che non c'era altra spiegazione al di fuori del fatto che e' qualcosa di completamente nuovo'', ha detto ancora il fisico. La nuova particella non somiglia assolutamente a nulla di tutto cio' che i fisici si aspettavano di vedere o che stessero cercando. ''Di sicuro sappiamo che non e' il bosone di Higgs e che potrebbe essere qualcosa di completamente nuovo. Nel mondo dei fisici - ha osservato - c'e' una grandissima eccitazione''. L'entusiasmo e' tale che gia' oggi i fisici teorici hanno pubblicati i primi articoli nei quali vedono nella nuova particella la conferma della loro teoria. Quello che e' certo, secondo Petronzio, e' che fra tutte le teorie che potrebbero spiegare la natura di questa particella ''non c'e' nemmeno una che non sia estrosa''. E' il caso del modello Technicolor, che prevede l'esistenza di particelle prodotte ad energie molto alte, o l'ipotesi che esista un nuovo modello, molto bizzarro, della particella Z scoperta dal Nobel Carlo Rubbia ...
Post n°812 pubblicato il 11 Aprile 2011 da diegobaratono
Da:"CNN.com"
Scientists speak out to discredit 'gay caveman' media reports By Phil Gast and Sarah Aarthun, CNN April 11, 2011 -- Updated 0007 GMT (0807 HKT) STORY HIGHLIGHTS They say the media has overblown findings from an archaeological dig Czech archaeologists have found a "transsexual" or "third gender grave" Sexual orientation cannot be determined from a skeleton, paleoanthropologist says The term "caveman" pertains to people who lived long before these unearthed remains (CNN) -- Reports that surfaced last week about the remains of a "gay caveman" found in the Czech Republic have prompted scientists to take on an unlikely foe -- an overhyped news media that may be overblowing the archaeological find. "Dudes! I could be wrong, but I think that to have a 'gay caveman,' you need a skeleton that is both gay and a caveman. And this ain't either!" John Hawks, an associate professor of anthropology at University of Wisconsin-Madison, wrote on his blog in bold type. Hawks joined a chorus of fellow paleoanthropologists, archaeologists and other bone experts who carefully dissected media reports about the dig, which began to increase after first appearing in British and Czech newspapers. The reports stem from a Tuesday press conference in Prague where Czech archaeologists came forward to reveal their findings -- the unusual burial site of a man dating from 2800-2500 B.C. "We believe this is one of the earliest cases of what could be described as a 'transsexual' or 'third gender grave' in the Czech Republic," the Czech Position newspaper quoted archaeologist Katerina Semradova as saying at the press conference. What followed were dozens of headlines from international news organizations declaring that a "gay caveman" had been found. The man's skeleton was found placed on its left side with the head facing west -- traditionally the position in which females in the culture were buried. Around the remains were items also typically associated with female burials instead of weapons normally found in male graves from that time period. Two other conventional male and female graves were found at the same site. But Hawks and others say the news media misinterpreted the findings. First, cavemen lived about 30,000 to 20,000 years ago. The remains found last week were from the Neolithic Age, about 5,000 years ago, Hawks told CNN. And while acknowledging the "unusual" circumstances of the burial, Hawks said there is no way you can tell someone is homosexual by examining a skeleton. Instead, the possibility of a third-gender grave -- as outlined by the archaeologists -- is more plausible, he said, noting that some cultures have a third category where, in some cases, men may have feminine characteristics or roles. "In anthropology, you can't equate third gender with homosexuality," he said. Kristina Killgrove, an adjunct assistant professor at the University of North Carolina, raised similar concerns, saying that using the term "gay" to describe the man is "the application of a modern word to an ancient population." More research could possibly determine the gender role of the man, but not his sexual orientation, said Killgrove, who specializes in bioarchaeology. And whatever the man's sexual orientation, Hawks said the fact that he was buried with others is "a sign of cultural acceptance," suggesting that other graves could shed some light statistically on how people were buried in that time. The takeaway from the viral reporting? "Don't talk to British tabloids," Hawks said.
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