Sound waves are widely used in medical imaging, such as when doctors take an ultrasound of a developing fetus. Now scientists have developed a way to use sound to probe tissue on a much tinier scale. Researchers from the University of Bordeaux in France deployed high-frequency sound waves to test the stiffness and viscosity of the nuclei of individual human cells. The scientists predict that the probe could eventually help answer questions such as how cells adhere to medical implants and why healthy cells turn cancerous.

"We have developed a new non-contact, non-invasive tool to measure the mechanical properties of cells at the sub-cell scale," says Bertrand Audoin, a professor in the mechanics laboratory at the University of Bordeaux. "This can be useful to follow cell activity or identify cell disease." The work will be presented at the 57th Annual Meeting of the Biophysical Society (BPS), held Feb. 2-6, 2013, in Philadelphia, Pa.

The technique that the research team used, called picosecond ultrasonics, was initially applied in the electronics industry in the mid-1980s as a way to measure the thickness of semiconductor chip layers. Audoin and his colleagues, in collaboration with a research group in biomaterials led by Marie-Christine Durrieu from the Institute of Chemistry & Biology of Membranes & Nano-objects at Bordeaux University, adapted picosecond ultrasonics to study living cells. They grew cells on a metal plate and then flashed the cell-metal interface with an ultra-short laser pulse to generate high-frequency sound waves. Another laser measured how the sound pulse propagated through the cells, giving the scientists clues about the mechanical properties of the individual cell components.

Famines plagued Iceland and food prices spiked in medieval England following extreme space weather events, according to a new study of historical data
The Earth's local interplanetary environment is a maelstrom of solar winds, giant clouds of hot plasma ejected from the Sun and violent magnetic fields. To a large extent, we are protected from this so-called space weather by our atmosphere and the Earth's magnetic field.

But every once in a while, these interplanetary storms are so ferocious that even our planetary defences fail. In 1989, for example, a powerful geomagnetic storm knocked out the Hydro-Quebec power grid leaving six million people without electricity.

Today, Lev Pustil'nik and Gregory Yom Din at Tel Aviv University in Israel say the effects of space weather could be much more significant than originally thought. These guys make the case that under certain special conditions, space weather can influence terrestrial weather so severely that it can have a dramatic effects on agriculture, causing crop failures, death and starvation.

Humans alone were responsible for the demise of Australia's extinct native predator, the Tasmanian Tiger, or thylacine, a new study has found.

Led by the University of Adelaide, the study has used new modelling to contradict a widespread belief that disease must have been a factor in the thylacine's demise.

The thylacine was a unique marsupial found throughout most of Tasmania before European settlement in 1803.

Between 1886 and 1909, the Tasmanian government encouraged people to hunt the carnivores and paid bounties on over 2000 thylacine carcasses.

Only a handful of animals were located after the bounty was lifted and the last known thylacine was captured in 1933.

"Many people believe that bounty hunting alone could not have driven the thylacine extinct and therefore claim that an unknown disease epidemic must have been responsible," study leader Thomas Prowse said in a statement on Thursday.

A team of international researchers has decoded the genome of the pigeon, 5,000 years after it was first domesticated, according to a study published Thursday.

Known as Columba livia, the rock pigeon is considered among the most common and varied species on the planet, consisting of 350 breeds with a slew of different features, and is among just a few bird genomes sequenced so far.

"Birds are a huge part of life on Earth, and we know surprisingly little about their genetics," said study co-author Michael Shapiro, an assistant professor of biology at the University of Utah.

"This will give us new insights into bird evolution."

Researchers found that a single mutation in the EphB2 gene, or Ephrin receptor B2, causes head and neck feathers to grow upward instead of downward, creating so-called head crests that help attract mates in many bird species.

Call it a Saturnian version of the Ouroboros, the mythical serpent that bites its own tail. In a new paper that provides the most detail yet about the life and death of a monstrous thunder-and-lightning storm on Saturn, scientists from NASA's Cassini mission describe how the massive storm churned around the planet until it encountered its own tail and sputtered out. It is the first time scientists have observed a storm consume itself in this way anywhere in the solar system.

"This Saturn storm behaved like a terrestrial hurricane - but with a twist unique to Saturn," said Andrew Ingersoll, a Cassini imaging team member based at the California Institute of Technology, Pasadena, who is a co-author on the new paper in the journal Icarus. "Even the giant storms at Jupiter don't consume themselves like this, which goes to show that nature can play many awe-inspiring variations on a theme and surprise us again and again."

Earth's hurricanes feed off the energy of warm water and leave a cold-water wake. This storm in Saturn's northern hemisphere also feasted off warm "air" in the gas giant's atmosphere. The storm, first detected on Dec. 5, 2010, and tracked by Cassini's radio and plasma wave subsystem and imaging cameras, erupted around 33 degrees north latitude. Shortly after the bright, turbulent head of the storm emerged and started moving west, it spawned a clockwise-spinning vortex that drifted much more slowly. Within months, the storm wrapped around the planet at that latitude, stretching about 190,000 miles (300,000 kilometers) in circumference, thundering and throwing lightning along the way.

By cloaking nanoparticles in the membranes of white blood cells, scientists at The Methodist Hospital Research Institute may have found a way to prevent the body from recognizing and destroying them before they deliver their drug payloads. The group describes its "LeukoLike Vectors", or LLVs, in the January issue of Nature Nanotechnology.

Our goal was to make a particle that is camouflaged within our bodies and escapes the surveillance of the immune system to reach its target undiscovered," said Department of Medicine Co-Chair Ennio Tasciotti, Ph.D., the study's principal investigator. "We accomplished this with the lipids and proteins present on the membrane of the very same cells of the immune system. We transferred the cell membranes to the surfaces of the particles and the result is that the body now recognizes these particles as its own and does not readily remove them."

Nanoparticles can deliver different types of drugs to specific cell types, for example, chemotherapy to cancer cells. But for all the benefits they offer and to get to where they need to go and deliver the needed drug, nanoparticles must somehow evade the body's immune system that recognizes them as intruders. The ability of the body's defenses to destroy nanoparticles is a major barrier to the use of nanotechnology in medicine. Systemically administered nanoparticles are captured and removed from the body within few minutes. With the membrane coating, they can survive for hours unharmed.

"Our cloaking strategy prevents the binding of opsonins - signaling proteins that activate the immune system," Tasciotti said. "We compared the absorption of proteins onto the surface of uncoated and coated particles to see how the particles might evade the immune system response."

Lack of such adaptations could explain why humans are more vulnerable to neck injury.

Medical illustrators and neurological imaging experts at Johns Hopkins have figured out how night-hunting owls can almost fully rotate their heads - by as much as 270 degrees in either direction - without damaging the delicate blood vessels in their necks and heads, and without cutting off blood supply to their brains.

In what may be the first use of angiography, CT scans and medical illustrations to examine the anatomy of a dozen of the big-eyed birds, the Johns Hopkins team, led by medical illustrator Fabian de Kok-Mercado, M.A., a recent graduate student in the Department of Art as Applied to Medicine, found four major biological adaptations designed to prevent injury from rotational head movements. The variations are all to the strigid animals' bone structure and vascular network needed to support its top-heavy head. The team's findings are acknowledged in the Feb.1 issue of the journal Science, as first-place prize winners in the posters and graphics category of the National Science Foundation's 2012 International Science & Engineering Visualization Challenge.

"Until now, brain imaging specialists like me who deal with human injuries caused by trauma to arteries in the head and neck have always been puzzled as to why rapid, twisting head movements did not leave thousands of owls lying dead on the forest floor from stroke," says study senior investigator and interventional neuroradiologist Philippe Gailloud, M.D. "The carotid and vertebral arteries in the neck of most animals - including owls and humans - are very fragile and highly susceptible to even minor tears of the vessel lining," adds Gailloud, an associate professor in the Russell H. Morgan Department of Radiology at the Johns Hopkins University School of Medicine.

Four thousands of years, our thirst for the legendary Fountain of Youth has been nearly as strong as our propensity for perpetuating the myth.

However, over the last 20 years, the fertile headwaters of molecular biology have been pumping out anything but folklore. Not only have these waters yielded a precipitous stretch in understanding the aging process, they're potentially guiding us closer to the source of everlasting youth.

From this flow now comes word that biologists from the University of California, Berkeley have tapped an influential longevity gene that can reverse cell degeneration associated with aging. That's right, they're not just offering a sip from the fountain, they're turning back the clock at the molecular level.

The new study, published in Cell Reports, represents a major discovery and offers new hope for development of targeted treatments for a long list of age-related degenerative diseases, such as heart disease, Alzheimer's and arthritis, just to name a few.

The biologists, lead by UC Berkeley assistant professor of nutritional science and toxicology Danica Chen, focused their attention on one protein in particular: SIRT3. It's one in a class of proteins called surtuins, long known to regulate aging.

Biologists found that SIRT3 plays a significant role in helping aged blood stem cells cope with the oxidative stress of the aging process. When the blood stem cells of aged mice were infused with SIRT3, it regenerated new blood cells, providing evidence of a reversal in the age-related degeneration of the cells' function.

"This is really the first demonstration that sirtuins may be able to actually reverse aging-associated degeneration," Chen told Discovery News.

A NASA spacecraft studying the sun has recorded amazing video of a giant plume of super-hot plasma erupting from the star's surface, only to crash back down hours later.

The solar plasma eruption, which NASA scientists nicknamed a "Dragon Tail," rose up from the sun's surface today (Jan. 31) and was spotted by the agency's Solar Dynamics Observatory, a powerful spacecraft that constantly records the sun's weather in different wavelengths of light.

A video of the Dragon Tail solar eruption shows a tendril of solar plasma, which scientists call a "filament," extending across the northeastern face of the sun over the course of four hours. Near the end of the event, the filament begins to break apart.

MPs call for Government to consider ending use of Cloud amid concerns that US authorities can access information

Warning comes during a Whitehall drive for government departments to store their electronic information externally with private companies

The Government should consider stopping sharing intelligence services with the US and end the use of Cloud computing due to concerns that sensitive personal information about British citizens can be spied upon by US authorities, MPs said today.

The warning comes during a Whitehall drive for government departments to store their electronic information externally with private companies, meaning taxpayers' private data could be left vulnerable to large-scale surveillance.

US law allows American agencies to access all private information stored by foreign nationals with firms falling within Washington's jurisdiction, if the information concerns US interests, without a warrant. Four suppliers of the UK Government's G-Cloud system are located in the US, leading to questions over the security of information is being stored overseas.