Findings reveal new understanding of how virus suppresses the human immune system.

Disabling a protein in Ebola virus cells can stop the virus from replicating and infecting the host, according to researchers from the Icahn School of Medicine at Mount Sinai. The data are published in July in the journal Cell Host and Microbe.

Ebola viruses cause severe disease in humans because they can deactivate the innate immune system. Christopher Basler, PhD, Associate Professor of Microbiology at Mount Sinai and his team have studied how Ebola viruses evade the immune system, and discovered that a viral protein called VP35 is critical to deactivating the immune system. They found that when VP35 interacts with an important cellular protein called PACT, it blocks PACT from activating the immune system, allowing the virus to spread.

A newfound asteroid about the size of a football field will cruise past Earth tonight (July 22), and you can follow all the action live online.

The near-Earth asteroid 2013 NE19, estimated to be between 194 feet and 426 feet wide (59 to 130 meters), will pass within 2.6 million miles (4.2 million kilometers) of Earth tonight - about 11 times the distance between our planet and the moon. There is no danger that it will strike Earth on this pass, scientists say.

The online Slooh Space Camera will webcast live views of 2013 NE19's close approach as seen from an observatory in the Canary Islands off the west coast of Africa. You can watch the asteroid webcast live here on SPACE.com at 9 p.m. EDT (0100 GMT Tuesday), courtesy of Slooh.

Asteroid 2013 NE19, which was discovered just last Monday (July 15), will be quite faint, making it a difficult target for backyard observers. But it should be readily visible in Slooh's remote-controlled telescope, the group said.

"Slooh's imaging technology and high-altitude location in the Canary Islands are well suited for a tricky object like this, which may be impossible for garden-variety setups to capture," Slooh CEO Michael Paolucci said in a statement.

The power of computing, and the thrill of its apparently infinite possibilities, has also long been a source of fear.

Going into a San Francisco second-hand book shop, shortly before a visit to Google's headquarters in California, I happened upon a copy of Dick Tracy, an old novel based on Chester Gould's cartoon strip starring America's favourite detective.

For a 1970 publication, the plot seemed remarkably topical. Dick, and his sidekick Sam Catchem, find themselves battling a sinister character known as "Mr Computer" who wants to control the world. His strange powers enable him to remember everything he hears or sees and recall it instantly. This is a bad guy who can store data, analyse voice patterns and read private thoughts.

My visit to the legendary "Googleplex" at Mountain View comes at an awkward time for the company. Edward Snowden's revelations about the snooping of the US Government's National Security Agency (NSA) in its clandestine electronic-surveillance programme PRISM have provoked a crisis of trust in Silicon Valley. Larry Page, Google co-founder and CEO, rushed out a blog to deny claims in leaked NSA documents that it - in parallel with other American internet giants - had been co-operating with the spying programme since 2009. "Any suggestion that Google is disclosing information about our users' internet activity on such a scale is completely false," he said.

When a young Indian-American woman walked into the funky L.A. jewelry boutique Tarina Tarantino, store manager Lauren Twisselman thought she was just like any other customer. She didn't realize the woman was actress and writer Mindy Kaling .

"I hadn't watched The Office,"Twisselman says. Kaling both wrote and appeared in the NBC hit.

This lack of recognition is precisely what the VIP-identification technology designed by NEC IT Solutions is supposed to prevent.

The U.K.-based company already supplies similar software to security services to help identify terrorists and criminals. The ID technology works by analyzing footage of people's faces as they walk through a door, taking measurements to create a numerical code known as a "face template," and checking it against a database.

In the retail setting, the database of customers' faces is comprised of celebrities and valued customers, according to London's Sunday Times. If a face is a match, the program sends an alert to staff via computer, iPad or smartphone, providing details like dress size, favorite buys or shopping history.

The software works even when people are wearing sunglasses, hats and scarves. Recent tests have found that facial hair, aging, or changes in weight or hair color do not affect the accuracy of the system.

When a flock of birds changes direction on a dime, it's easy to imagine that the group is controlled by a single, collective mind. But in reality, the individual matters. That's the message of new research on group navigation in homing pigeons. The study used computer tracking to reveal a complex hierarchy, where even birds with a low social rank on the ground may be trusted leaders in the air.

In research on animal social dynamics, large mammals such as wolves and gorillas have received a lot of attention, because their groups' smaller numbers make them easier to study, says Andrew King, a behavioral ecologist at Swansea University in the United Kingdom who was not involved in the study. But when hundreds or thousands of creatures synchronize their movements, the decision-making process is harder to sort out. King says that these big groups have traditionally been viewed as hoards of anonymous agents in a democracy. "Five or so years ago, papers were saying that you should be finding consensus decisions where everybody has an equal say."

And yet elaborate synchronized movements arise from individuals with various abilities and social roles. Zoologist Dora Biro of the University of Oxford in the United Kingdom wanted to investigate how a flock of pigeons manages to stay organized as it navigates the skies. "Different individuals within these flocks might have different ideas about where they want to go," she says "but at the same time, they want to maintain a kind of cohesive flock, because there's safety in numbers." Computerized tracking methods make this type of research possible. Remote visual sensors and GPS units on the birds can keep tabs on every bird at every moment, and complex data analysis can tease out meaningful social patterns.

Conventional theories have placed life on land for the last 500 million years, but a new study from a team of American and Australian researchers might push that back to 2.2 billion years.

To support their claim, the scientists presented evidence in the form of tiny newly discovered fossils the size of a match head called Diskagma buttonii that were discovered in ancient soil samples.

"They certainly were not plants or animals, but something rather more simple," said co-author Gregory Retallack, co-director of paleontological collections at the University of Oregon's Museum of Natural and Cultural History.

The fossils are small, vase-like structures with a cup on one end and a basal tube on the other end. Retallack says these ancient organisms are comparable to a modern soil organism called Geosiphon, a fungus containing a cavity filled with symbiotic cyanobacteria.

"There is independent evidence for cyanobacteria, but not fungi, of the same geological age, and these new fossils set a new and earlier benchmark for the greening of the land," he said. "This gains added significance because fossil soils hosting the fossils have long been taken as evidence for a marked rise in the amount of oxygen in the atmosphere at about 2.4 billion to 2.2 billion years ago, widely called the Great Oxidation Event."

That event, which occurred around 2.4 billion years ago, boosted atmospheric oxygen to around 5 percent - still a far cry from today's level of 21 percent.

An analysis of data returned by the Curiosity rover, which landed on the planet a year ago, suggests there was a major upheaval which could have been caused by volcanic eruptions or a massive collision which stripped away the atmosphere.

The rover has returned its first measurements of the makeup of gases, including argon, oxygen, nitrogen, carbon monoxide and carbon dioxide, in the Martian atmosphere.

The results, published in two parallel studies in the journal Science, allow scientists to better understand how the Martian climate changed, and understand whether it ever had the right conditions for life.

Dr Chris Webster at Nasa's Jet Propulsion Laboratory in Pasadena, lead author on one of the studies, said the data enabled direct comparisons with the Earth's climate.

"As Mars became a planet and its magma solidified, catastrophic outgassing occurred while volatiles were delivered by impact of comets and other small bodies", Dr Webster said.

"Our Curiosity measurements are - for the first time - accurate enough to make direct comparisons with measurements done on Earth on meteorites using sophisticated large instrumentation that gives high accuracy results."

Behind every great man, the saying goes, there's a great woman. And behind every sperm, there may be an X chromosome gene. In humans, the Y chromosome makes men, men, or so researchers have thought: It contains genes that are responsible for sex determination, male development, and male fertility. But now a team has discovered that X - "the female chromosome" - could also play a significant role in maleness. It contains scores of genes that are active only in tissue destined to become sperm. The finding shakes up our ideas about how sex chromosomes influence gender and also suggests that at least some parts of the X chromosome are playing an unexpectedly dynamic role in evolution.

Each mammal has a pair of sex chromosomes. Females have two copies of the X chromosome, and males have one, along with a Y chromosome. The body needs only one active copy of the X chromosome, so in females, the second copy is disabled. Almost 50 years ago, a geneticist named Susumu Ohno proposed that this shutdown slowed the evolution of the X chromosome, and he predicted that its genes would be very similar across most mammals. David Page, a geneticist at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, wanted to check if that was true between mice and humans, which are separated by 80 million years of evolution.

Although the genomes of both species had already been decoded, there were gaps and mistakes in the DNA sequence of the human X chromosome that first needed to be filled in or fixed. Using a special sequencing technique that it developed, Page's research team determined the order of the DNA bases in those gaps - many contained multiple duplicated regions of DNA that were impossible to decipher with the technology available when the X chromosome was first sequenced. Then the researchers compared the genes in the mouse and human versions of the chromosome.

Warfare was uncommon among hunter-gatherers, and killings among nomadic groups were often due to competition for women or interpersonal disputes, researchers in Finland said Thursday.

Their study in the US journal Science suggests that the origins of war were not -- as some have argued -- rooted in roving hunter-gather groups but rather in cultures that held land and livestock and knew how to farm for food.

For clues on what life was like before colonial powers, missionaries and traders entered the scene, anthropologists examined a subset of records from a well-known database that contains information on 186 cultures around the world.

Douglas Fry and Patrik Soderberg of Abo Akademi University in Vasa, Finland, chose to examine only the earliest existing records on those that had no horses and no permanent settlements, leaving them with 21 mobile foraging societies for analysis.

"To be purists, we took only the oldest high-quality sources for each culture," Fry told the journal Science, adding that these studies would best showcase the people's traditional ways.

The groups included the Montagnais people of Canada, the Andamanese people of India, the Botocudos of Brazil, and the !Kung people who live in isolated areas of Botswana, Angola and Namibia.

A fossilized elephant tusk at least 100,000 years old has been discovered on the seafloor off the Sicilian coast, according to a survey of underwater archaeologists. Discovered during a series of archaeological dives in the waters off Torretta Granitola, a village on the island's southwestern coast, the tusk is more than 3 feet long.

"It was found embedded on the sea bottom in Pleistocene alluvional deposits," the Superintendency of Maritime Cultural Heritage of Sicily said in a statement.
In the same area, Giampaolo Mirabile, a local diver, found some years ago two molar teeth belonging to the dwarf elephant Palaeoloxodon mnaidriensis, or Elephas Mnaidriensis, a species that roamed Sicily between 100,000 and 200,000 years ago.

"The tusk' size confirms the previous finding and points to the same extinct species," Sebastiano Tusa, Sicily's superintendent of the Sea Office, said.