wild life maroc: octobre 2013

mardi 29 octobre 2013

الحشرات الأحفوريّة

أستاذ العلوم البريّة والاحفوريّة Matthew Clapham بجامعة كاليفورنيا في Santa Cruz, والطالب Jered Karr: قاما بمُراكمة مجموعة من التفاصيل والمعطيات المتصلة بطول أجنحةالحشرات الأحفوريّة, قاموا بتحليل حجم الحشرات وصلته بمستويات الاوكسجين بالغلاف الجوي, خلال مئات ملايين الاعوام من تطور الحشرات.يؤكّد Clapham على:" حجم حشرات ما قبل التأريخ مرتبط بكميّة الاوكسجين الموجودة بالحقبة التي تقدّر بحوالي 200 مليون عام ". ويُضيف:" حيث ازداد الاوكسجين ولكن حجم الحشرة قل

طائر القرزبيل

يستخدم منقاره القوي والمتقاطع لفتح ثمار الصنوبر

النسر_الملك....

هذا الطائر يستغل تيارات الهواء أثناء الطيران في حمله كي تساعده على الطيران وتوفير طاقته خلال بحثه عن الطعام في الغابات أو الصحاري. ..

Today In History. What Happened This Day In History

1618		Sir Walter Raleigh is executed. After the death of Queen Elizabeth, Raleigh's enemies spread rumors that he was opposed the accession of King James.
1787		Mozart's opera Don Giovanni opens in Prague.
1814		The Demologos, the first steam-powered warship, launched in New York City.
1901		Leon Czolgosz is electrocuted for the assassination of US President William McKinley. Czolgosz, an anarchist, shot McKinley on September 6 during a public reception at the Temple of Music in Buffalo, N.Y. Despite early hopes of recovery, McKinley died September 14, in Buffalo, NY.
1927		Russian archaeologist Peter Kozloff apparently uncovers the tomb of Genghis Khan in the Gobi Desert, a claim still in dispute.
1929		Black Tuesday–the most catastrophic day in stock market history, the herald of the Great Depression. 16 million shares were sold at declining prices. By mid-November $30 billion of the $80 billion worth of stocks listed in September will have been wiped out.
1945		The first ball-point pen goes is sold by Gimbell's department store in New York for a price of $12.
1949		Alonzo G. Moron of the Virgin Islands becomes the first African-American president of Hampton Institute, Hampton, Virginia.
1952		French forces launch Operation Lorraine against Viet Minh supply bases in Indochina.
1964		Thieves steal a jewel collection–including the world's largest sapphire, the 565-carat "Star of India," and the 100-carat DeLong ruby–from the Museum of Natural History in New York. The thieves were caught and most of the jewels recovered.
1969		The U.S. Supreme Court orders immediate desegregation, superseding the previous "with all deliberate speed" ruling.
1969		First computer-to-computer link; the link is accomplished through ARPANET, forerunner of the Internet.
1972		Palestinian guerrillas kill an airport employee and hijack a plane, carrying 27 passengers, to Cuba. They force West Germany to release 3 terrorists who were involved in the Munich Massacre.
1983		More than 500,000 people protest in The Hague, The Netherlands, against cruise missiles.
1986		The last stretch of Britain's M25 motorway opens.
1998		South Africa's Truth and Reconciliation Commission reports condemns both sides on the Apartheid issue for committing atrocities.
1998		John Glenn, at age 77, becomes the oldest person to go into outer space. He is part of the crew of Space Shuttle Discovery, STS-95.
1998		The deadliest Atlantic hurricane on record up to that time, Hurricane Mitch, makes landfall in Honduras (in 2005 Hurricane Wilma surpassed it); nearly 11,000 people died and approximately the same number were missing.
2004		For the first time, Osama bin Laden admits direct responsibility for the Sept. 11, 2001, terrorist attacks in the US; his comments are part of a video broadcast by the Al Jazeera network.
2008		Delta and Northwest airlines merge, forming the world's largest airline.
2012		Hurricane Sandy devastates much of the East Coast of the US; nearly 300 die directly or indirectly from the storm.
Born on October 29
1882		Jean Giraudoux, French dramatist, novelist and diplomat, famous for his book Tiger at the Gates.
1891		Fanny Brice, comedian, singer and actress.
1897		Joseph G. Göbbels, German Nazi Propaganda Minister who committed suicide in Hitler's bunker.
1905		Henry Green, novelist (Living, Party Going).
1910		A. J. Ayer, English philosopher.
1921		Bill Maudlin, American cartoonist whose GI characters "Willie" and "Joe" appeared in Stars and Stripes newspapers during World War II.
1938		Ralph Bakshi, Palestinian-American director of live films and animated full-length films for adults including 1972's Fritz the Cat (first animated film to be rated X by the Motion Picture Association of America), Wizards (1977) and The Lord of the Rings (1978).
1943		Don Simpson, film producer, screenwriter, actor; (co-producer Flashdance, 1985; Top Gun, 1986).
1945		Melba Moore, disco and R&B singer, actress ("You Stepped into My Life," "Lean on Me").
1946		Peter Green, guitarist, songwriter, founder of the band Fleetwood Mac; regarded as one of the greatest guitarists of all time.
1947		Richard Dreyfuss, actor (American Graffiti, Jaws; won Academy Award for Best Actor for 1977's The Goodbye Girl).
1948		Kate Jackson, actress, director, producer (original Charlie's Angels TV series, Scarecrow and Mrs. King TV series).
1954		Lee Child, author; creator of the Jack Reacher novel series.
1958		David Remnick, journals, author, magazine editor (The New Yorker); won Pulitzer Prize forLenin's Tomb: The Last Days of the Soviet Empire (1994).
1971		Winona Ryder, actress, producer (Beetlejuice; Girl, Interrupted).

Beach Cave, Algarve, Portugal

lundi 28 octobre 2013

my friend

"These images captured by nature photographer Lassi Rautiainen, show an unusual friendship between a lone wolf and a bear. The images show how the young brown bear and grey wolf would sit down to eat together and even enjoy views over the landscape for up to two-hours.

It’s never clear why these unusual pairings occur, but wild animals that get separated from their mothers too early, or that are cast out from the group (like this wolf, perhaps), sometimes take odd steps as they figure out how to survive on their own. A partner of any species might simply bring comfort, a sense of safety."

Rautiainen adds: "When I realised that no one had observed bears and wolves living near each other and becoming friends in Europe, I concentrated more and more on getting pictures to show what can happen in nature."

Holy cow! Dino flatulence may have changed ancient climate

Never mind cows: dinosaurs passing gas could have released enough climate-altering methane gas to warm the prehistoric world, according to newly published calculations.

While many a student has snickered over the observation that flatulating livestock contribute to the atmospheric greenhouse gases blamed for global warming today, dealing with a hulking apatosaurus (a.k.a. brontosaurus) with indigestion might have been no laughing matter.

The new research published in the May 8 issue of the research journal Current Biology also suggests that this beast and its kin—giant dinosaurs known as sauropods—could have harbored enough methane-making microbes in their guts to make a substantial climate impact.

“A simple mathematical model suggests that the microbes living in sauropod dinosaurs may have produced enough methane to have an important effect,” said Dave Wilkinson of Liverpool John Moores University in the U.K. “Our calculations suggest that these dinosaurs could have produced more methane than all modern sources—both natural and man-made—put together.”

Methane and other greenhouse gases tend to warm the climate by trapping heat in the atmosphere, scientists say.

Distinctive for their enormous size and long necks, sauropods were widespread about 150 million years ago. As in cows, methane-producing microbes aided the sauropods’ digestion by fermenting their plant food. Wilkinson and study coauthor Graeme Ruxton from the University of St Andrews, U.K. were studying sauropod ecology when a question dawned on them: If modern cows produce enough methane gas to be of interest to climate scientists, what about sauropods? They teamed up with methane expert Euan Nisbet at the University of London to work out the numbers.

“Clearly, trying to estimate this for animals that are unlike anything living has to be a bit of an educated guess,” Wilkinson said.

Physiologists have studied methane production from a range of modern animals to derive equations that predict methane production from animals of different sizes. It turns out those calculations depend only on the animal’s weight. A medium-sized sauropod weighed over 20 tons. Using available estimates of population densities, the scientists calculated global methane emissions from sauropods to have been 520 million metric tons yearly, comparable to total modern methane emissions.

Before modern industry took off, methane emissions were roughly 200 million metric tons a year. Modern ruminant animals, including cows, goats, giraffes, and others, produce about one-fourth to one-half that amount. The study’s conclusions not only show “just how strange and wonderful the workings of the planet are,” but also serve as a useful reminder for the importance of microbes and methane for global climate, the researchers wrote.

Scientists: birds are just baby dinosaurs, in a way

There’s a good reason birds are so much cuter and less threatening than their scary ancestors—the dinosaurs—if new research is correct.

It’s because birds are, in a sense, dinosaurs stuck in baby mode.

“When we look at birds, we are actually looking at juvenile dinosaurs” to a great degree, said Arkhat Abzhanov of Harvard University, co-author of a report on the findings.

Skulls of three types of archosaur—alligator, primitive dinosaur, and early bird. The left column represents juveniles and the right column represents adults. (Image courtesy U. of Texas at Austin)

Abzhanov and colleagues analyzed dozens of bird and dinosaur skulls. They found that rather than take years to reach sexual maturity, as many dinosaurs did, birds sped up the clock—some species take as little as 12 weeks to mature—allowing them to retain the physical characteristics of baby dinosaurs.

The report appeared May 27 in an online edition of the journal Nature.

In evolution, species change because some characteristics are more useful than others in a given environment. Thus individuals with more of those traits thrive, and through their offspring, spread those features through a population. Individuals lacking those traits gradually drop out. As this goes on, species can eventually become nearly unrecognizable compared to their old selves.

Most evolutionary research has focused on the physical structure of organisms, but “what is interesting about this research,” Abzhanov said, is that it illustrates how great changes can occur “simply by changing the relative timing of events in a creature’s development.” Thus, he added, “nature has produced the modern bird—an entirely new creature and one that, with approximately 10,000 species, is today the most successful group of land vertebrates on the planet.”

Dinosaurs have long snouts and mouths bristling with teeth, while birds have proportionally larger eyes and brains. But what inspired the study was the realization that skulls of modern birds and juvenile dinosaurs show surprising similarity, researchers said.

“No one had told the big story of the evolution of the bird head before,” said Bhart-Anjan Bhullar, a Harvard doctoral student and first author of the study. “There had been a number of smaller studies that focused on particular points of the anatomy, but no one had looked at the entire picture. ... When you do that, you see the origins of the features that make the bird head special lie deep in the history of the evolution of Archosaurs, a group of animals that were the dominant, meat-eating animals for millions of years.”

With colleagues at The University of Texas at Austin, the researchers conducted CT scans on dozens of skulls, ranging from modern birds to theropods—the dinosaurs most closely related to birds—to early dinosaur species. By marking various “landmarks” in the skull the scientists tracked how the overall shape changed over millions of years.

“We examined skulls from the entire lineage that gave rise to modern birds,” Abzhanov said. “We looked back approximately 250 million years, to the Archosaurs, the group which gave rise to crocodiles and alligators as well as modern birds.”

It turned out, he said, that while early dinosaurs, even those closely related to modern birds, undergo vast structural changes as they mature, the skulls of juvenile and adult birds remain remarkably similar. In the case of modern birds, Abzhanov said, the change is the result of a process known as progenesis, which causes an animal to reach sexual maturity earlier.

“To really study something you have to look at its whole existence, and understand that one portion of its life can be parceled out and made into the entire lifespan of a new, and in this case, radically successful organism,” Bhullar said.

75% of African lion habitat gone, study says

Lions have lost three-quarters of their original natural habitat in Africa as people have taken it over for their own purposes, according to a new study.

The report reaches a somber conclusion: Western Africa, in particular, must be given money to protect lions. Billed as the fullest assessment to date on the state of African savannah, or grassland, habitat, the report says the habitat loss has devastated lion populations.

A lion in West Africa. (Credit: Philipp Henschel/Panthe)

“From an original area a third larger than the continental United States, only 25 percent remains,” said Stuart Pimm of Duke University in Durham, N.C., co-author of the report, which appears online this week in the journal Biodiversity and Conservation. Primm and other scientists coordinated by the university co-wrote the report with Philipp Henschel, coordinator of the New York-based Panthera's Lion Program Survey.

The group used Google Earth's high-resolution satellite imagery to examined savannah across Africa, which comprises the majority of the lion's current range. They also analyzed human population density data to identify areas of suitable habitat. They identified just 67 isolated regions continent-wide where significant lion populations may persist. Of these, only 15 were estimated to maintain at least 500 lions.

The study also found that in West Africa, where the species is classified as Regionally Endangered on the Red List of Threatened Species, fewer than 500 lions remain, scattered across eight isolated regions.

“Lions have been hit hardest in West Africa, where local governments often lack direct incentives to protect them,” Henschel said. “While lions generate billions of tourist dollars across Eastern and Southern Africa, spurring governments to invest in their protection, wildlife-based tourism is only slowly developing in West Africa. Currently lions still have little economic value in the region, and West African governments will require significant foreign assistance in stabilizing remaining populations until sustainable local conservation efforts can be developed.”

Panthera collaborates in the Washington-based National Geographic Society's Big Cats Initiative, which is meant to address the most serious threats facing big cats in the wild and help channel financial support to well-designed conservation programs.

Pill may cut HIV risk as much as 99%

Daily use of a pill approved to protect against HIV infection cuts a man’s risk of getting the virus by 99 percent, a new study indicates.

The research also offers the first evidence that even imperfect adherence to the treatment regimen can provide a big reduction in the risk of acquiring the virus, which causes AIDS. Participants in the research were found to be able to cut their HIV infection risk by 76 percent merely by taking two doses a week.

The study, published in the Sept. 12 online issue of the research journal Science Translational Medicine, examines the effectiveness of a FDA-approved drug known as tenofovir disoproxil fumarate (brand name Truvada).

The research builds on a 2010 study by Robert Grant at the University of California, San Francisco and the Gladstone Institute in San Francisco, along with colleagues. The team found that Truvada—which had been used for years to treat HIV-positive patients—could also prevent new infections in people likely to come in contact with the virus.

But questions about the drug’s real-world effectiveness remained—in particular concerning the issue of adherence to a regimen of a pill a day. “There was concern that the protective effect of Truvada was fragile, and that individuals taking the drug would need to adhere perfectly to daily regimen for it to work,” said Grant. “This new study suggests that Truvada can help block the virus even if the person on a daily regimen doesn’t always adhere perfectly.”

The study examined the risk of HIV acquisition in men who have sex with men. Participants different doses of the drug. Men came into a clinic every day and were given either two pills per week, four pills per week or seven pills per week. The researchers then compared drug concentrations from their study to drug concentrations from a previous study.

The research team estimates that participants could reduce their risk of HIV by 76 percent taking two doses per week, 96 percent by taking four doses per week, and 99 percent by taking seven doses per week.

The timing of the dosing relative to sexual intercourse likely matters, based on research done in non-human primates, although this could not be investigated in detail in people, the researchers added. Higher drug concentrations and more frequent use may be required for women because the drugs are not concentrated as much in the female genital tract, the authors noted.

“Patients should still take one pill a day to achieve the best results, and we encourage people to explore multiple methods to prevent HIV—such as regular condom use, early treatment of HIV infection in partners, good communication and male circumcision,” Grant said. “We hope that our findings lead to more effective use of prevention tools that finally squash the HIV/AIDS epidemic.”

Gene that may have helped make people smart ID’d

Researchers have found a gene that they say helps explain how humans evolved from apes.

Called miR-941, it seems to have played a crucial role in brain development and may shed light on how we learned to use tools and language, the scientists say. They add that it's the first time a new gene, carried only by people and not by apes, has been shown to have a specific function in the body.

“This new molecule sprang from nowhere at a time when our species was undergoing dramatic changes: living longer, walking upright, learning how to use tools and how to communicate,” said Martin Taylor of the University of Edinburgh in Scotland, who led the study. “We're now hopeful that we will find more new genes that help show what makes us human.”

The gene has been found to be highly active in two areas of the brain that control our decision making and language abilities. The study suggests it could have a role in the advanced brain functions that make us human.

A team at the university compared the human genome to 11 other species of mammals, including chimpanzees, gorillas, mouse and rat, to find the differences between them. The results, published in the journal Nature Communications, indicate the gene is unique to humans. The researchers say it emerged between six and one million years ago, after the human lineage had branched off from apes.

Most differences between species occur as a result of changes to existing genes, or the duplication and deletion of genes. But scientists say this gene emerged fully functional out of non-coding genetic material, previously termed “junk DNA,” in a startlingly short time in evolutionary terms.

http://wrd.cm/1gVYv0C

Stunning photos show the solar flare explosions that happened all weekend long on the sun. (Image: NASA/SDO)

“Cloud map” of planet beyond our system a first

Astronomers using data from NASA’s Kepler and Spitzer space telescopes have created what they call the first cloud map of a planet beyond our solar system. It’s a sizzling, Jupiter-like world known as Kepler-7b.

High clouds in the west and clear skies in the east mark the planet, the map indicates. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.

This diagram represents the cloud map of Kepler 7b, left, with Jupiter shown alongside for size comparison. (Image credit: NASA/JPL-Caltech/MIT)

“By observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution ‘map’ of this giant, gaseous planet,” said Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge.

He is the lead author of a paper on the work, accepted for publication in the journal Astrophysical Journal Letters.

“We wouldn’t expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds.”

Kepler has discovered more than 150 exoplanets, which are planets outside our solar system. Kepler-7b, about 50 percent wider than Jupiter, was one of the first. The telescope is out of commission for planet-hunting, but astronomers are still poring over almost four years’ worth of old data.

Kepler’s visible-light observations of Kepler-7b’s moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere. But these data alone weren’t enough to decipher whether the bright spot was coming from clouds or heat, according to the astronomers. The Spitzer telescope helped answer that.

Like Kepler, Spitzer can fix its gaze at a star system as a planet orbits around the star, gathering clues about the planet’s atmosphere. Spitzer’s ability to detect infrared light, a low-energy form of light invisible to the unaided eye, means it was able to measure Kepler-7b’s temperature, estimating it to be between 1,500 and 1,800 degrees Fahrenheit (1,100 and 1,300 Kelvin).

This is relatively cool for a planet that orbits so close to its star – less than 1/15 as close to its sun as we are to ours – and according to astronomers, too cool to be the source of light Kepler observed. Instead, they determined, light from the planet’s star is bouncing off cloud tops on the planet’s west side.

“Kepler-7b reflects much more light than most giant planets we’ve found, which we attribute to clouds in the upper atmosphere,” said Thomas Barclay, Kepler scientist at NASA’s Ames Research Center in Moffett Field, Calif. “Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time—it has a remarkably stable climate.”

The findings are seen as an early step toward using similar techniques to study the atmospheres of planets more like Earth in makeup and size.

“Cloud map” of planet beyond our system a first

This diagram represents the cloud map of Kepler 7b, left, with Jupiter shown alongside for size comparison. (Image credit: NASA/JPL-Caltech/MIT)

“Cloud map” of planet beyond our system a first

This diagram represents the cloud map of Kepler 7b, left, with Jupiter shown alongside for size comparison. (Image credit: NASA/JPL-Caltech/MIT)

“Maternal instincts” seen in group of colorful beetles

A group of related, colorful beetles in the thick foliage of tropical forests shows signs of maternal instincts and active care, scientists say.

In a report, researchers described “maternal” behaviors in eight species within a subfamily of leaf beetles known as broad-shouldered leaf beetles, or Chrysomelinae. The findings were published in a special issue of the research journal Zookeys.

Larvae of the species Doryphora paykullimove among leaves, followed by their mother, in Panama. (Credit: S. Van Bael)

Mothers “actively defend offspring” as well as the eggs, wrote the researchers, Donald M. Windsor of the Smithsonian Tropical Research Institute in Balboa-Ancon, Panama, and colleagues.

Maternal care in insects is rarely seen in such active forms, though common in lower-level forms such as insects positioning their eggs so the newborns will have access to a good food source.

Beetle mothers in two species within the Chrysomelinae group treated the leaf on which their youngsters were born as a sort of nest to be protected, the scientists found. The mothers reacted aggressively to invaders, and charged toward the edge the leaf when a person put a thin stick in the area, they wrote. Stamping and leaf-shaking were other common reactions, they added.

A camera held 10 cm (4 inches) under and to the side of the “natal leaf” got the strongest reaction, according to the scientists. Mothers also were found to “guard” larvae by straddling them.

Other species of beetles showed “less aggressive” forms of maternal care, they added. The scientists said some mothers seem to make changes to the leaves where their offspring are born. And once the young beetles, or larvae, are born, some mothers were described as “herding” them to make them go in desired directions and keep them together in little groups.

The investigators said it’s not clear why these behaviors evolved in these Central and South American beetles. “Large voids remain in our understanding of the natural history of both groups, including the identity and importance of predators and parasitoids and the diverse ways in which mothers may be influencing the survival of offspring,” Windsor and colleagues wrote.

Already-approved drug tied to longer, healthy life in mice

The first drug to successfully extend the lifespan of normal lab mice also does so in a way that prolongs their healthy existence, according to a new study.

Researchers hope the drug, rapamycin, may also serve to prolong life and ward off aging-related diseases in people, especially as it’s already tested and approved for another human use: to prevent transplant rejection.

A popular strain of lab mice known as C57BL/6, used in the new study by Yiqiang Zhang and colleagues at the University of Texas Health Science Center at San Antonio. (Image courtesy FDA)

But obstacles remain before any human use of rapamycin as a longevity booster. It’s unclear what dosages and regimens might be required for such a purpose. Concerns about side effects linger. And mouse studies have used a special encapsulation method that’s not currently used in human consumption of the drug.

A biotech firm has sprung up in San Antonio, Texas in hopes of exploiting new commercial possibilities for rapamycin, and its officials have said that clinical trials are expected soon.

In the new study, mice were fed rapamycin as part of their diet starting when they were 19 months—the equivalent of about 60 human years—old. The measured lifespan increases were more modest than in some previous studies. Compared to untreated mice, the lifespan of the treated rodents went up by about 3 percent on average, although the difference rose to 7 percent for mice who made it to older ages to begin with.

Previous studies had yielded more dramatic results.

A study in the July 2009 issue of Nature, using a similar methodology but different mouse strains, had found increases as high as about 10.5 percent for older mice on rapamycin compared to untreated. Another piece of research found that if treatment was started when the mice were about half as old, then the average survival increase jumped to about 14 percent. That study appeared in the February 2011 issue of The Journals of Gerontology: Biological Sciences.The new study, in the May 16 online edition of the same journal, focused on the health effects in addition to the lifespan effects. “Whether the life-extending effects of rapamycin treatment are reflected in extended health has not yet been extensively investigated,” wrote the authors, researchers with the University of Texas Health Science Center at San Antonio.

The authors included scientists who have licensed rapamycin-related technologies to the biotech company, Rapamycin Holdings Inc.

They also wrote that they investigated the health effects in greater detail because “increasing life span without simultaneously increasing health span is a fool’s errand.” They found that treated mice enjoyed health benefits including increased stride length and better results on a test of endurance.

Rapamycin’s lifespan benefits to mice have tended to be greater for females, which received lifespan boosts up to 80 percent greater than the males depending on the study.

The investigators in the new study used rapamycin that had been “microencapsulated” by a special method in order to resist degradation when mixed with the rodent chow. This isn’t the same way rapamycin, a prescription drug, is normally taken in human clinical use, although it is taken orally.

Rapamycin is thought to exert its effects on lifespan by suppressing the activity of a chemical pathway in the body known as mTOR, which helps to govern growth and survival responses in cells.

Rapamycin also helps prevent transplant rejection by blocking certain immune system cells, leading to concerns of harmful immune-suppressing side effects. But these have not proved problematic in the mouse studies, according to scientists.

Very few substances have been found to reliably prolong lifespan in lab animals. Before rapamycin, the one considered perhaps most promising was resveratrol, found to extend lifespan in roundworms, yeast and certain fish. But such benefits in lab mice, seen as an important stepping-stone toward human studies, were reported only for mice that were obese.

Rapamycin is so named because it was discovered coming from soil bacteria at Easter Island, also known as Rapa Nui.

galaxies

Space photo weekend edition: Crashing galaxies in Pandora's cluster reveal the location of dark matter.

http://wrd.cm/1gSGNLJ

dimanche 27 octobre 2013

Lioness Hunts Zebra

Untamed and Uncut- Zebra Escapes Lion's Jaws

japan

rio di janiro

colorado

norway

portugal

in tayland

lozern suis

ttttoooookkkkyyyyoooooo

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new york city

Space photo weekend edition: New photos reveal the amazing lakes at Titan's north pole.

http://wrd.cm/17QaKCz

samedi 26 octobre 2013

We want to bring the attention of any of you who enjoy puzzle games to one called Phylo, developed by Prof. Jérôme Waldispühl and his colleagues from McGill University. (Link to game: http://bit.ly/1bivTHG)

Described as “a cross between Tetris, Rubik’s cube and an old-fashioned sliding-tile puzzle game”, where the goal is to line up coloured rectangles, gamers are actually helping pinpoint genetic anomalies that researchers believe may play a role in a range of diseases including diabetes, breast cancer and retinoblastoma. Since it was first launched, players ranging from teenagers to seniors have suggested solutions for over 4,000 puzzles based on genomic data.

So if you like puzzle games, consider giving it a try!

You can read the rest of the press release here: http://bit.ly/1ig6fpM

In the transcriptional races, the larger RNA polymerase I has always seemed to work faster than the more easily studied RNA polymerase II – and now scientists have an idea of why!
(Though keep in mind that all three eukaryotic RNA polymerases do play different roles in a cell, so it’s not a question of which is ‘better’)

Having been able to determine the 3-dimensional structure of RNA polymerase I, they realized that the larger size is in part because the polymerase already incorporates many of the ‘extra’ helper proteins that RNA polymerase II needs to bind to in order to do its job. They also discovered that, what in RNA polymerase II are two separate modules, has in RNA polymerase I been combined into a single multi-tasking component.

Though these changes result in RNA polymerase I being able to produce RNA more quickly, it also makes it harder to regulate the process. One structural mechanism they discovered for doing so is a built-in loop that can block the space DNA would normally dock onto.

You can read more here: http://bit.ly/1g0obrx

Image: The cell’s Swiss-army knife: the structure of RNA polymerase I revealed an efficiency-boosting strategy. Credit: EMBL/C. Férnandez-Tornero & P. Riedinger

Mutator S is one of the first proteins on the scene when mismatched nucleotides make an appearance. And thanks to a new technique that involves hybrid nanomaterials and small angle X-ray scattering technology, researchers have for the first time been able to ‘observe’ the work being done by MutS, helping to validate the “beads-on-a-string” model of DNA repair.

You can read more about it here: http://bit.ly/1aJQwel

Image: DNA_Repair. redondoself/Flickr

Adivina adivinador: ¿Qué animal se camufla en el bosque, tiene un cuerno flexible sobre su hocico y reapareció recientemente en Ecuador, 50 años después de haber sido declarado extinto? ¿No se te ocurre? Se trata del curioso lagarto Pinocho: http://bit.ly/GZjq24

mardi 29 octobre 2013

lundi 28 octobre 2013

Stunning photos show the solar flare explosions that happened all weekend long on the sun. (Image: NASA/SDO)

Space photo weekend edition: Crashing galaxies in Pandora's cluster reveal the location of dark matter.http://wrd.cm/1gSGNLJ

dimanche 27 octobre 2013

Space photo weekend edition: New photos reveal the amazing lakes at Titan's north pole. http://wrd.cm/17QaKCz

samedi 26 octobre 2013

Adivina adivinador: ¿Qué animal se camufla en el bosque, tiene un cuerno flexible sobre su hocico y reapareció recientemente en Ecuador, 50 años después de haber sido declarado extinto? ¿No se te ocurre? Se trata del curioso lagarto Pinocho: http://bit.ly/GZjq24

Space photo weekend edition: Crashing galaxies in Pandora's cluster reveal the location of dark matter.

http://wrd.cm/1gSGNLJ

Space photo weekend edition: New photos reveal the amazing lakes at Titan's north pole.

http://wrd.cm/17QaKCz