Παρασκευή 25 Απριλίου 2014

ScienceDaily: Top Science News

ScienceDaily: Top Science News


Microscopic organism plays a big role in ocean carbon cycling

Posted: 24 Apr 2014 12:18 PM PDT

Scientists have taken a leap forward in understanding the microscopic underpinnings of the ocean carbon cycle by pinpointing a bacterium that appears to play a dominant role in carbon consumption.

Genomic diversity and admixture differs for stone-age Scandinavian foragers and farmers

Posted: 24 Apr 2014 12:18 PM PDT

Scientists report a breakthrough on understanding the demographic history of Stone-Age humans. A genomic analysis of eleven Stone-Age human remains from Scandinavia revealed that expanding Stone-age farmers assimilated local hunter-gatherers, and that the hunter-gatherers were historically in lower numbers than the farmers. The transition between a hunting-gathering lifestyle and a farming lifestyle has been debated for a century. As scientists learned to work with DNA from ancient human material, a complete new way to learn about the people in that period opened up.

Some corals adjusting to rising ocean temperatures

Posted: 24 Apr 2014 11:37 AM PDT

Scientists have revealed how some corals can quickly switch on or off certain genes in order to survive in warmer-than-average tidal waters. To most people, 86-degree Fahrenheit water is pleasant for bathing and swimming. To most sea creatures, however, it's deadly. As climate change heats up ocean temperatures, the future of species such as coral, which provides sustenance and livelihoods to a billion people, is threatened.

Cosmic illusion revealed: Gravitational lens magnifies supernova

Posted: 24 Apr 2014 11:36 AM PDT

Astronomers have announced the discovery of a galaxy that magnified a background, Type Ia supernova thirty-fold through gravitational lensing. This first example of strong gravitational lensing of a supernova confirms the team's previous explanation for the unusual properties of this supernova.

Ocean microbes display remarkable genetic diversity: One species, a few drops of seawater, hundreds of coexisting subpopulations

Posted: 24 Apr 2014 11:36 AM PDT

The smallest, most abundant marine microbe, Prochlorococcus, is a photosynthetic bacteria species essential to the marine ecosystem. An estimated billion billion billion of the single-cell creatures live in the oceans, forming the base of the marine food chain and occupying a range of ecological niches based on temperature, light and chemical preferences, and interactions with other species. But the full extent and characteristics of diversity within this single species remains a puzzle.

Genome yields insights into golden eagle vision, smell

Posted: 24 Apr 2014 11:10 AM PDT

Scientists have sequenced the genome of the golden eagle, providing a bird's-eye view of eagle features that could lead to more effective conservation strategies.

Tsetse fly genome reveals weaknesses: International 10-year project unravels biology of disease-causing fly

Posted: 24 Apr 2014 11:09 AM PDT

Mining the genome of the disease-transmitting tsetse fly, researchers have revealed the genetic adaptions that allow it to have such unique biology and transmit disease to both humans and animals. The tsetse fly spreads the parasitic diseases human African trypanosomiasis, known as sleeping sickness, and Nagana that infect humans and animals respectively. Throughout sub-Saharan Africa, 70 million people are currently at risk of deadly infection.

Astronomical forensics uncover planetary disks in NASA's Hubble archive

Posted: 24 Apr 2014 11:09 AM PDT

Astronomers using NASA's Hubble Space Telescope have applied a new image processing technique to obtain near-infrared scattered light photos of five disks observed around young stars in the Mikulski Archive for Space Telescopes database. These disks are telltale evidence for newly formed planets.

Carbon loss from soil accelerating climate change

Posted: 24 Apr 2014 11:09 AM PDT

New research has found that increased levels of carbon dioxide in the atmosphere cause soil microbes to produce more carbon dioxide, accelerating climate change. This research challenges our previous understanding about how carbon accumulates in soil.

Scientists build new 'off switch' to shut down neural activity

Posted: 24 Apr 2014 11:09 AM PDT

Nearly a decade ago, the era of optogenetics was ushered in with the development of channelrhodopsins, light-activated ion channels that can, with the flick of a switch, instantaneously turn on neurons in which they are genetically expressed. What has lagged behind, however, is the ability to use light to inactivate neurons with an equal level of reliability and efficiency. Now, scientists have used an analysis of channelrhodopsin's molecular structure to guide a series of genetic mutations to the ion channel that grant the power to silence neurons with an unprecedented level of control.

Skin layer grown from human stem cells could replace animals in drug, cosmetics testing

Posted: 24 Apr 2014 09:52 AM PDT

The first lab-grown epidermis -- the outermost skin layer -- with a functional permeability barrier akin to real skin has been developed by scientists. The new epidermis, grown from human pluripotent stem cells, offers a cost-effective alternative lab model for testing drugs and cosmetics, and could also help to develop new therapies for rare and common skin disorders.

Blood cells reprogrammed into blood stem cells in mice

Posted: 24 Apr 2014 09:52 AM PDT

Researchers have reprogrammed mature blood cells from mice into blood-forming hematopoietic stem cells, using a cocktail of eight genetic switches called transcription factors. The reprogrammed cells are able to self-renew like HSCs and can give rise to all of the cellular components of the blood like HSCs. The findings mark a significant step toward a major goal of regenerative medicine: the ability to produce HSCs suitable for hematopoietic stem cell transplantation from other cell types.

New genetic brain disorder in humans discovered

Posted: 24 Apr 2014 09:51 AM PDT

A newly identified genetic disorder associated with degeneration of the central and peripheral nervous systems in humans, along with the genetic cause, has been reported by researchers. By performing DNA sequencing of more than 4,000 families affected by neurological problems, the two research teams independently discovered that a disease marked by reduced brain size and sensory and motor defects is caused by a mutation in a gene called CLP1, which is known to regulate tRNA metabolism in cells.

Oldest pterodactyloid species discovered: Primitive flying reptile took wing 163 million years ago

Posted: 24 Apr 2014 09:46 AM PDT

Scientists have discovered and named the earliest and most primitive pterodactyloid -- a group of flying reptiles that would go on to become the largest known flying creatures to have ever existed -- and established they flew above Earth some 163 million years ago, longer than previously known.

Your T-shirt's ringing: Printable tiny flexible cell phones for clothes?

Posted: 24 Apr 2014 07:28 AM PDT

A new version of 'spaser' technology being investigated could mean that mobile phones become so small, efficient, and flexible they could be printed on clothing. A spaser is effectively a nanoscale laser or nanolaser. It emits a beam of light through the vibration of free electrons, rather than the space-consuming electromagnetic wave emission process of a traditional laser.

Microbes provide insights into evolution of human language

Posted: 23 Apr 2014 07:14 PM PDT

Research into Pseudomonas aeruginosa, a type of bacteria common in water and soil, shows that they can communicate in a way that was previously thought to be unique to humans and perhaps some other primates. The bacteria used combinatorial communication, in which two signals are used together to achieve an effect that is different to the sum of the effects of the component parts.

New shape discovered using rubber bands

Posted: 23 Apr 2014 07:12 PM PDT

While setting out to fabricate new springs to support a cephalopod-inspired imaging project, a group of researchers stumbled upon a surprising discovery: the hemihelix, a shape rarely seen in nature. This made the researchers wonder: Were the three-dimensional structures they observed randomly occurring, or are there specific factors that control their formation? The scientists answered that question by performing experiments in which they stretched, joined, and then released rubber strips.

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