الجمعة، 16 مايو 2014

ScienceDaily: Top News

ScienceDaily: Top News


How some trypanosomes cause sleeping sickness while others don't

Posted: 15 May 2014 02:35 PM PDT

Trypanosome parasites transmitted by tsetse flies cause devastating diseases in humans and livestock. Different subspecies infect different hosts: Trypanosoma brucei brucei infects cattle but is non-infectious to humans, whereas T. b. gambiense and T. b. rhodesiense cause sleeping sickness in humans. A new study reveals how humans can fight off some trypanosomes but not others.

Caught in the act: Study probes evolution of California insect

Posted: 15 May 2014 01:38 PM PDT

A first-of-its-kind study this week suggests that the genomes of new species may evolve in a similar, repeatable fashion -- even in cases where populations are evolving in parallel at separate locations. Evolutionary biologists used a combination of ecological fieldwork and genomic assays to see how natural selection is playing out across the genome of a Southern California stick insect that is in the process of evolving into two unique species.

Emissions from forests influence very first stage of cloud formation

Posted: 15 May 2014 12:41 PM PDT

Clouds are the largest source of uncertainty in present climate models. Much of the uncertainty surrounding clouds' effect on climate stems from the complexity of cloud formation. New research sheds light on new particle formation -- the very first step of cloud formation. The findings closely match observations in the atmosphere and can help make climate prediction models more accurate.

Children of parents in technical jobs at higher risk for autism

Posted: 15 May 2014 12:41 PM PDT

Children of fathers who are in technical occupations are more likely to have an autism spectrum disorder, according to researchers. Fathers who worked in engineering were two times as likely to have a child with an autism spectrum disorder (ASD). Those who worked in finance were four times more likely and those who worked in health care occupations were six times more likely to have a child on the autism spectrum. There was no association with a mother's occupation.

Going beyond the surface: New tech could take light-based cancer treatment deep inside the body

Posted: 15 May 2014 11:28 AM PDT

Photodynamic therapy (PDT) is an effective treatment for easily accessible tumors such as oral and skin cancer. But the procedure, which uses lasers to activate special drugs called photosensitizing agents, isn't adept at fighting cancer deep inside the body. Thankfully, that's changing due to new technology that could bring PDT into areas of the body which were previously inaccessible. The new tech involves using near-infrared beams of light that, upon penetrating deep into the body, are converted into visible light that activates the drug and destroys the tumor.

Silly Putty material inspires better batteries: Silicon dioxide used to make lithium-ion batteries that last three times longer

Posted: 15 May 2014 11:28 AM PDT

Using a material found in Silly Putty and surgical tubing, a group of researchers have developed a new way to make lithium-ion batteries that will last three times longer between charges compared to the current industry standard.

Definitive evidence of how zeolites grow: Tracking crystal growth in real time

Posted: 15 May 2014 11:28 AM PDT

Researchers have found the first definitive evidence of how silicalite-1 zeolites grow, showing that growth is a concerted process involving both the attachment of nanoparticles and the addition of molecules. Both processes appear to happen simultaneously, said the lead author.

Quantum simulator gives clues about magnetism

Posted: 15 May 2014 11:28 AM PDT

Researchers optically trapped a cloud of gas a billion times colder than air in a very low-pressure vacuum, and found a lower speed limit to diffusion. Assembling the puzzles of quantum materials is, in some ways, like dipping a wire hanger into a vat of soapy water, says one of the researchers. Long before mathematical equations could explain the shapes and angles in the soap foams, mathematicians conjectured that soap films naturally found the geometry that minimized surface area, thus solving the problem of minimal surfaces. They could be created simply by blowing soap bubbles.

First 'heavy mouse' leads to first lab-grown tissue mapped from atomic life

Posted: 15 May 2014 11:28 AM PDT

The molecular 'fingerprint' for tissue taken from the first isotope-enriched mouse has huge potential for scientific breakthroughs, as well as improved medical implants. Earliest research based on the data has already revealed that a molecule thought to exist for repairing DNA may also in fact trigger bone formation.

Oldest most complete, genetically intact human skeleton in New World

Posted: 15 May 2014 11:27 AM PDT

In a paper released today in the journal Science, an international team of researchers and cave divers present the results of an expedition that discovered a near-complete early American human skeleton with an intact cranium and preserved DNA. The remains were found surrounded by a variety of extinct animals more than 40 meters (130 feet) below sea level in Hoyo Negro, a deep pit within the Sac Actun cave system on Mexico's Yucatán Peninsula.

Giant telescope tackles orbit and size of exoplanet

Posted: 15 May 2014 10:22 AM PDT

Using one of the world's largest telescopes, astronomers have tracked the orbit of a planet at least four times the size of Jupiter. The scientists were able to identify the orbit of the exoplanet, Beta Pictoris b, which sits 63 light years from our solar system, by using the Gemini Planet Imager's (GPI) next-generation, high-contrast adaptive optics (AO) system. This approach is sometimes referred to as extreme AO.

Single episode of binge drinking can adversely affect health, according to new study

Posted: 15 May 2014 10:22 AM PDT

A single episode of binge drinking can have significant negative health effects resulting in bacteria leaking from the gut, leading to increased levels of endotoxins in the blood, clinical scientists have found. Greater gut permeability and increased endotoxin levels have been linked to many of the health issues related to chronic drinking, including alcoholic liver disease.

Dramatic Improvements in nanogenerator power efficiency for wearable, implantable electronics

Posted: 15 May 2014 09:33 AM PDT

The energy efficiency of a new piezoelectric nanogenerator has increased by almost 40 times, one step closer toward the commercialization of flexible energy harvesters that can supply power infinitely to wearable, implantable electronic devices. Nanogenerators are innovative self-powered energy harvesters that convert kinetic energy created from vibrational and mechanical sources into electrical power, removing the need of external circuits or batteries for electronic devices. This innovation is vital in realizing sustainable energy generation in isolated, inaccessible, or indoor environments and even in the human body.

Richest marine reptile fossil bed along Africa's South Atlantic coast is dated at 71.5 mya

Posted: 15 May 2014 09:33 AM PDT

New research is the first to tie the stable carbon isotope record of Africa's South Atlantic coast to global records. This record clarifies the age of rocks at Bentiaba, Angola. The work provides a 71.5 million year age for the richest marine reptile fossil bed along the South Atlantic. The new record of time represents nearly 30 million years of Cretaceous fossils and environments in the ancient South Atlantic Ocean.

Cancer's potential on-off switch linked to epigenetics

Posted: 15 May 2014 09:33 AM PDT

An 'on and off' epigenetic switch could be a common mechanism behind the development of different types of cancer, a group of researchers has proposed. Epigenetics is the phenomena whereby genetically identical cells express their genes differently, resulting in different physical traits. The existence of this epigenetic switch is indirectly supported by the fact that tumors develop through different stages. When cells rapidly grow during cancer progression, they become stuck in their current stage of development and their cell characteristics do not change.

Genetic tracking identifies cancer stem cells in human patients

Posted: 15 May 2014 09:33 AM PDT

The gene mutations driving cancer have been tracked for the first time in patients back to a distinct set of cells at the root of cancer -- cancer stem cells. The international research team studied a group of patients with myelodysplastic syndromes -- a malignant blood condition which frequently develops into acute myeloid leukemia. The researchers say their findings offer conclusive evidence for the existence of cancer stem cells.

First test of pluripotent stem cell therapy in monkeys is successful

Posted: 15 May 2014 09:32 AM PDT

For the first time in an animal that is more closely related to humans, researchers have demonstrated that it is possible to make new bone from stem-cell-like induced pluripotent stem cells (iPSCs) made from an individual animal's own skin cells. The study in monkeys also shows that there is some risk that those iPSCs could seed tumors, but that unfortunate outcome appears to be less likely than studies in immune-compromised mice would suggest.

How octopuses don't tie themselves in knots

Posted: 15 May 2014 09:32 AM PDT

An octopus's arms are covered in hundreds of suckers that will stick to just about anything, with one important exception. Those suckers generally won't grab onto the octopus itself; otherwise, the impressively flexible animals would quickly find themselves all tangled up. Researchers observed the behavior of amputated octopus arms, which remain very active for an hour after separation. Those observations showed that the arms never grabbed octopus skin, though they would grab a skinned octopus arm.

The brain: Key to a better computer

Posted: 15 May 2014 09:32 AM PDT

Your brain is incredibly well-suited to handling whatever comes along, plus it's tough and operates on little energy. Those attributes -- dealing with real-world situations, resiliency and energy efficiency -- are precisely what might be possible with neuro-inspired computing. Neuro-inspired computing seeks to develop algorithms that would run on computers that function more like a brain than a conventional computer.

Combination therapy a potential strategy for treating Niemann Pick disease

Posted: 15 May 2014 09:32 AM PDT

A potential dual-pronged approach to treating Niemann-Pick type C (NPC) disease, a rare but devastating genetic disorder, has been identified by researchers. By studying nerve and liver cells grown from NPC patient-derived induced pluripotent stem cells (iPSCs), the scientists determined that although cholesterol does accumulate abnormally in the cells of NPC patients, a more significant problem may be defective autophagy -— a basic cellular function that degrades and recycles unneeded or faulty molecules, components, or organelles in a cell.

Mice with multiple sclerosis-like condition walk again after human stem cell treatment

Posted: 15 May 2014 09:32 AM PDT

Mice severely disabled by a condition similar to multiple sclerosis (MS) were able to walk less than two weeks following treatment with human neural stem cells. The finding uncovers potential new avenues for treating MS. When scientists transplanted human stem cells into MS mice, they predicted the cells would be rejected, much like rejection of an organ transplant. Expecting no benefit to the mice, they were surprised when the experiment yielded spectacular results.

Getting chemo first may help in rectal cancer

Posted: 15 May 2014 08:33 AM PDT

If chemotherapy is offered before radiation and surgery in rectal cancer, more patients will be able to tolerate it and receive a full regimen of treatment, a new trial demonstrates. Studies have shown that only about 60 percent of rectal cancer patients comply with postoperative chemotherapy, but in this study, more than 90 percent of the patients were able to complete a full regimen.

Color of blood: Pigment helps stage symbiosis in squid

Posted: 15 May 2014 08:32 AM PDT

The relationship between the Hawaiian bobtail squid and the bacterium Vibrio fischeri is well chronicled, but a group of microbiologists adds a new wrinkle to the story: it seems that the blood pigment hemocyanin plays a dual role in helping the squid recruit and sustain the bacterium it uses to avoid predation. "In the early events of symbiosis, hemocyanin appears to have antimicrobial activity," says one co-author.

New imaging technology: Phase contrast x-ray

Posted: 15 May 2014 07:38 AM PDT

Phase contrast X-ray imaging has enabled researchers to perform mammographic imaging that allows greater precision in the assessment of breast cancer and its precursors. The technique could improve biopsy diagnostics and follow-up. One of the advantages of the phase contrast technique is its ability to provide images of high contrast. In the future, this technique can aid physicians to determine in a non-invasive way where premalignant and malignant breast lesions are most likely located.

Effects of alcohol in young binge drinkers predicts future alcoholism

Posted: 15 May 2014 07:37 AM PDT

Heavy social drinkers who report greater stimulation and reward from alcohol are more likely to develop alcohol use disorder over time, report researchers. The findings run counter to existing hypotheses that innate tolerance to alcohol drives alcoholism. "Heavy drinkers who felt alcohol's stimulant and pleasurable effects at the highest levels in their 20s were the ones with the riskiest drinking profiles in the future and most likely to go on and have alcohol problems in their 30s," the lead said, "In comparison, participants reporting fewer positive effects of alcohol were more likely to mature out of binge drinking as they aged."

Jupiter's Great Red Spot is smaller than ever seen before

Posted: 15 May 2014 07:36 AM PDT

Recent Hubble observations confirm that Jupiter's Great Red Spot, a swirling storm feature larger than Earth, has shrunken to the smallest size astronomers have ever measured. Jupiter's Great Red Spot is a churning anticyclonic storm.

Inheriting Mitochondria: Where does your father's go?

Posted: 15 May 2014 06:56 AM PDT

While it's common knowledge that all organisms inherit their mitochondria -- the cell's "power plants" -- from their mothers, it hasn't been clear what happens to all the father's mitochondria. Surprisingly, how -- and why -- paternal mitochondria are prevented from getting passed on to their offspring after fertilization is still shrouded in mystery; the only thing that's certain is that there must be a compelling reason, seeing as this phenomenon has been conserved throughout evolution. A crucial step in fertilization, and this issue, is now better understood, thanks to recent research.

Drought monitoring using space-based rainfall observations

Posted: 15 May 2014 06:56 AM PDT

Using modern weather satellites to monitor rainfall has become a robust, widely practiced technique. However, establishing a reliable context for relating space-based rainfall observations to current and historical ground-based rainfall data has been difficult. Now researchers are using space-based rainfall observations and comparing them to current and historical ground-based rainfall data to observe early warning of drought and famine to monitor rainfall in near real-time, at a high resolution, over most of the globe.

This is your brain on meditation: Brain processes more thoughts, feelings during meditation, study shows

Posted: 15 May 2014 06:55 AM PDT

Meditation is more than just a way to calm our thoughts and lower stress levels: our brain processes more thoughts and feelings during meditation than when you are simply relaxing, a coalition of researchers has found. "The study indicates that nondirective meditation allows for more room to process memories and emotions than during concentrated meditation," says a co-author of the study.

West Antarctic Ice Sheet collapse is under way

Posted: 15 May 2014 06:09 AM PDT

Models using detailed topographic maps show that the collapse of the West Antarctic ice sheet has begun. Fast-moving Thwaites Glacier, which acts as a linchpin on the rest of the ice sheet, will likely disappear in a matter of centuries.

Invisible wireless networks brought to life as stunning 'spectres'

Posted: 15 May 2014 06:09 AM PDT

Invisible wireless networks are transformed into beautiful beams of color in a series of photographs. The images show the 'spectres' of wireless networks sweeping, swirling and swooping around a ghostly figure. They were produced as part of a project which aims to bring the invisible world around us to life.

HIV patient nutrition more vital than once assumed

Posted: 15 May 2014 06:09 AM PDT

Access to HIV medication has significantly reduced the number of AIDS related deaths in Africa. Yet in a number of African countries, one in four HIV infected still dies within the first few months of commencing treatment. One reason for these deaths is malnutrition which causes the HIV-virus to develop more aggressively. Now a team of researchers has shown that a dietary supplement given during the first months of HIV treatment significantly improves the general condition of patients.

Marine scientists create world’s first global jellyfish database

Posted: 15 May 2014 06:09 AM PDT

An international study has led to the creation of the world's first global database of jellyfish records to map jellyfish populations in the oceans. The debate regarding future trends, and subsequent ecological, biogeochemical and societal impacts, of jellyfish and jellyfish blooms in a changing ocean is hampered by a lack of information about jellyfish biomass and distribution from which to compare. To address this knowledge gap, scientists used the Jellyfish Database Initiative, or JeDI, to map jellyfish biomass in the upper 200m of the world's oceans and explore the underlying environmental causes driving the observed patterns of distribution.

Stability lost as supernovae explode

Posted: 15 May 2014 06:08 AM PDT

Exploding supernovae are a phenomenon that is still not fully understood. The trouble is that the state of nuclear matter in stars cannot be reproduced on Earth. Scientists have now developed a new model of supernovae represented as dynamical systems subject to a loss of stability, just before they explode. Because similar stability losses also occur in dynamical systems in nature, this model could be used to predict natural catastrophes before they happen.

Studying behavior using light to control neurons

Posted: 15 May 2014 06:07 AM PDT

Some of the neurons responsible for behavioral decisions in rats have been identified in a new study. Using a technique that employs light to control nerve cell activity, researchers inactivated a region of the brain and showed that it caused the rats to behave more flexibly while trying to get a reward. The technique, called optogenetics, allows researchers to "show that the firing or inhibition of certain neurons has a causative relationship with a given behavior, whereas previous methods only allowed us to correlate neuronal activity with behavior," says one researcher.

High-speed solar winds increase lightning strikes on Earth

Posted: 14 May 2014 05:57 PM PDT

Scientists have discovered new evidence to suggest that lightning on Earth is triggered not only by cosmic rays from space, but also by energetic particles from the sun. Researchers found a link between increased thunderstorm activity on Earth and streams of high-energy particles accelerated by the solar wind, offering compelling evidence that particles from space help trigger lightning bolts.

Study may explain link between antibiotic use in infants, asthma

Posted: 14 May 2014 05:57 PM PDT

Children who receive antibiotics before their first birthday might be at an increased risk of developing asthma, new research has confirmed. However, the findings suggest that it is impaired viral immunity and genetic variants on a region of chromosome 17 that increase the risk of both antibiotic use in early life and later development of asthma rather than the antibiotics themselves, as previously thought.

Scientists investigate the role of the 'silent killer' inside deep-diving animals

Posted: 14 May 2014 03:28 PM PDT

Scientists have furthered science's understanding of carbon monoxide's natural characteristics and limitations by studying the gas in one of the world's best divers: the elephant seal. Colorless and odorless, carbon monoxide (CO) is now monitored in many homes with inexpensive detectors. In human bodies, CO is produced naturally as a byproduct of the breakdown of hemoglobin -- molecules responsible for transporting oxygen -- inside red blood cells. To their surprise, researchers discovered that carbon monoxide is bound to 10 percent of the hemoglobin in adult elephant seals, or 10 times the amount found in healthy humans, and roughly comparable to someone who smokes 40 cigarettes per day.

Nanowire bridging transistors open way to next-generation electronics

Posted: 14 May 2014 01:54 PM PDT

Combining atoms of semiconductor materials into nanowires and structures on top of silicon surfaces shows promise for a new generation of fast, robust electronic and photonic devices. Scientists have recently demonstrated three-dimensional nanowire transistors using this approach that open exciting opportunities for integrating other semiconductors, such as gallium nitride, on silicon substrates.

Control methane now, greenhouse gas expert warns

Posted: 14 May 2014 01:52 PM PDT

As the shale gas boom continues, the atmosphere receives more methane, adding to Earth's greenhouse gas problem. A greenhouse gas expert and ecology and environmental biology professor fears that we may not be many years away from an environmental tipping point – and disaster. "Society needs to wean itself from the addiction to fossil fuels as quickly as possible," he said. "But to replace some fossil fuels – coal, oil – with another, like natural gas, will not suffice as an approach to take on global warming. Rather, we should embrace the technologies of the 21st century and convert our energy systems to ones that rely on wind, solar and water power."

Brain Study: Deconstructing goal-oriented movement

Posted: 14 May 2014 12:32 PM PDT

Our human brains are filled with maps: visual maps of our external environments, and motor maps that define how we interact physically within those environments. Somehow these separate points of reference need to correspond with -- and to -- one another in order for us to act, whether it's grasping a coffee cup or hitting a tennis ball.

Scientists test hearing in Bristol Bay beluga whale population

Posted: 14 May 2014 12:32 PM PDT

How well do marine mammals hear in the wild? A biologist and his colleagues are the first to publish a study of hearing in a population of wild marine mammals. In human populations, there is variability in our hearing ability: older people don't hear as well as younger people; males don't hear high frequencies as well as females. But in the tested beluga population, there was surprisingly little variation. "The bottom line is they all hear pretty well," said the lead researcher.

New insight into thermoelectric materials may boost green technologies

Posted: 14 May 2014 12:32 PM PDT

Physicists have found remarkable thermoelectric properties for a metal that may impact the search for materials useful in power generation, refrigeration or energy detection. Thermoelectric materials can turn a temperature difference into an electric voltage.

Technology may help with imaging brain tumors, research shows

Posted: 14 May 2014 12:32 PM PDT

Possible new ways to image glioblastoma multiforme tumors -- a form of brain tumor -- using the SapC-DOPS technology have been revealed by researchers. Brain tumors are an extremely serious example of this and are not only difficult to treat -- both adult and pediatric patients have a five-year survival rate of only 30 percent -- but also have even been difficult to image, which could provide important information for deciding next steps in the treatment process.

How cone snail venom minimizes pain

Posted: 14 May 2014 11:23 AM PDT

The venom from marine cone snails, used to immobilize prey, contains numerous peptides called conotoxins, some of which can act as painkillers in mammals. Researchers provide new insight into the mechanisms by which one conotoxin, Vc1.1, inhibits pain.

Possible new plan of attack for opening, closing blood-brain barrier

Posted: 14 May 2014 10:34 AM PDT

The gene that controls blood-brain barrier permeability through a little-studied phenomenon calledtranscytosis has been identified by researchers for the first time. The study, which was conducted in mice, offers a new way to devise strategies to open the blood-brain barrier for drug delivery or restore it in neurological disease.

Deformable mirror corrects errors

Posted: 14 May 2014 10:30 AM PDT

Very high power is needed to cut or weld using a laser beam. But this creates its own problem: the beam's energy deforms the mirrors that are focusing it to a point. When this happens, the beam expands and loses intensity. A new type of mirror can deform itself so as to correct this unwanted deformation.

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