Why don't trees "bleed" to death when they are injured? Researchers from Virginia Tech, the Georg-August University of Gottingen, Germany, and the Jackson Laboratory of Bar Harbor, Maine, have discovered how "check valves" in wood cells control sap flow and protect trees when they are injured. The study, featured on the cover of the September issue of the American Journal of Botany, used a special microscope to reveal how nanostructures help contain damage within microscopic cavities called bordered pits in wood-fiber cells. The pits allow sap to circulate through adjacent ...

Researchers expect the climate to become warmer in the future and predict that climate change will have a significant impact on the Arctic. How will a warming Arctic affect the polar bears? The East Greenlandic population of polar bears resides in an area, where the Arctic sea ice is expected to disappear very late. However, the decline in the ice sheet here occurs at a rate of almost 1% per year, one of the highest rates measured in the entire Arctic region. How does this affect the prey of the polar bears - and, in turn, the polar bears' intake of contaminants? An international ...

Bethesda, Md. (Sept. 20, 2013)—Asthma is a serious public health problem. An estimated 300 million people worldwide suffer from this sometimes deadly lung disease, a number expected to increase to 400 million by 2025. One well-established risk factor for asthma is having a mother who smoked during her pregnancy. However, researchers recently discovered that smoking can have a lasting legacy. When animal mothers are exposed to nicotine during pregnancy—a proxy for smoking—their grandchildren were also at an increased risk of asthma, even though they were never exposed to ...

In a landmark discovery, the final piece in the puzzle of understanding how the brain circuitry vital to normal fertility in humans and other mammals operates has been put together by researchers at New Zealand's University of Otago. Their new findings, which appear in the leading international journal Nature Communications, will be critical to enabling the design of novel therapies for infertile couples as well as new forms of contraception. The research team, led by Otago neuroscientist Professor Allan Herbison, have discovered the key cellular location of signalling ...

OAKLAND, Calif., Sept. 20, 2013 — Digoxin, a drug commonly used to treat heart conditions, was associated with a 72 percent higher rate of death among adults with newly diagnosed systolic heart failure, according to a Kaiser Permanente study that appears in the current online issue of Circulation: Cardiovascular Quality and Outcomes. Digoxin is a drug derived from digitalis, a plant that has been used for more than 200 years to treat heart failure. "These findings suggest that the use of digoxin should be reevaluated for the treatment of systolic heart failure in contemporary ...

LA JOLLA, CA -- Researchers at The Scripps Research Institute (TSRI) discovered that an antibody that binds and neutralizes HIV likely also targets the body's own "self" proteins. This finding could complicate the development of HIV vaccines designed to elicit this protective antibody, called 4E10, and others like it, as doing so might be dangerous or inefficient. "We developed two new mouse models that allow us to visualize the fate of the rare B cells that can see HIV and we thought could be stimulated by vaccines to produce neutralizing antibodies -- the type of antibodies ...

High-intensity exercise is shown to be protective against coronary heart disease (CHD) and is well known as a popular and time-saving approach to getting fit. But what about people who already have heart disease? Previously, these patients were told to exercise, but only at a moderate intensity to protect their hearts. More recently, however, researchers have found that high-intensity exercise is very beneficial for these patients. But how intense should these sessions actually be? A new study from the K. G. Jebsen -- Center of Exercise in Medicine at the Norwegian University ...

ANN ARBOR, Mich. -- When we're born, our brains aren't very organized. Every brain cell talks to lots of other nearby cells, sending and receiving signals across connections called synapses. But as we grow and learn, things get a bit more stable. The brain pathways that will serve us our whole lives start to organize, and less-active, inefficient synapses shut down. But why and how does this happen? And what happens when it doesn't go normally? New research from the University of Michigan Medical School may help explain. In a new paper in Nature Neuroscience, a ...

Today, the genomes of more than 250 fungi have been sequenced. Among the basal filamentous ascomycetes – a group of ascomycetes that includes e.g. truffles and morels – only one representative has been analysed so far: the truffle Tuber melanosporum. "With 125 million base pairs, the truffle genome is unusually big, yet it is coding for relatively few genes, namely some 7,500," says Minou Nowrousian from the Department of General and Molecular Botany. "Until now, it was not clear whether this is typical of basal filamentous ascomycetes or whether it is caused by the truffle's ...

In the course of life, aging processes, environmental influences and lifestyle factors such as smoking or diet induce biochemical alterations to the DNA. Frequently, these lead to DNA methylation, a process in which methyl groups are added to particular DNA segments, without changing the DNA sequence. Such processes can influence gene function and are known as epigenetics. Scientists of the Institute of Genetic Epidemiology (IGE) and the Research Unit Molecular Epidemiology (AME) at Helmholtz Zentrum München are seeking to determine what association exists between these ...

A prominent tuft of spiny hair on the back, a white tail tip and three pairs of teats represent the unique set of characteristics describing a new genus of rat which has been discovered in the Moluccan province of Indonesia. This region had a profound influence on the British Naturalist Alfred Russell Wallace who independently developed the theory of evolution alongside Charles Darwin. The international team of zoologists was led by the Museum Zoologicum Bogoriense in Indonesia and the Center for Macroecology, Evolution and Climate at the University of Copenhagen. One ...

The digestive systems of all animals contain a large number of different bacteria. Humans are no exception and our intestines provide warmth, shelter and food to a vast range of unicellular organisms, many of which are either beneficial to their hosts or at least cause no ill effects other than consuming some of the food we ingest. However, several species have been associated with disease. Among them is Helicobacter pylori, which may play a part in causing chronic gastritis and gastric ulcers. An ancient colonizer recently discovered Helicobacter pylori was only discovered ...

The story of the sodium-potassium pump has strong ties to Denmark. In 1997, the Danish scientist Jens Chr. Skou received the Nobel Prize in Chemistry for his discovery, and over the years, research on the pump has remained a strong focus area at Aarhus University. In 2007, the joint efforts of various research teams at Aarhus University led to the description of the structure of the potassium-bound state of the pump - now, Danish researchers have also described the other state of the pump; the sodium-bound state. The results were recently published in the journal Science. The ...

Up to half a million people in Britain today may not know it, but in their genetic material they carry a particular form of herpesvirus 6 inherited from a parent. The study from the world-renowned Department of Genetics at the University of Leicester, is funded principally by the Medical Research Council (MRC), and published in the journal Nucleic Acids Research. The research led by Dr Nicola Royle, Senior Lecturer in Genetics, has identified a mechanism by which the inherited herpesvirus 6 can escape from the chromosome and may be able to reactivate under certain ...

The drug combination of elvitegravir, cobicistat, emtricitabine and tenofovir disoproxil (elvitegravir fixed combination, trade name: Stribild) has been approved in Germany since May 2013 for the treatment of adults infected with human immunodeficiency virus type 1 (HIV-1). In an early benefit assessment pursuant to the Act on the Reform of the Market for Medicinal Products (AMNOG), the German Institute for Quality and Efficiency in Health Care (IQWiG) examined whether an added benefit is proven for this combination over the current standard therapy. This is not the case: ...

In patients with an acute heart attack, remote ischemic conditioning – intermittent inflation of a blood pressure cuff to cut off blood flow to the arm during transportation to hospital for acute balloon dilatation – reduces subsequent cardiac symptoms and mortality after acute heart attack. The results are presented by researchers from Aarhus University Hospital and Aarhus University in European Heart Journal on-line 12 September 2013. Activating the body's defense mechanism Lack of oxygen for short periods of time in a distant organ by intermittently stopping blood ...

WASHINGTON, D.C. Sept. 20, 2013 -- Memory based on electrically-induced "resistive switching" effects have generated a great deal of interest among engineers searching for faster and smaller devices because resistive switching would allow for a higher memory density. Researchers have tested a number of oxide materials for their promise in resistive switching memories, and now a team of researchers in Singapore have demonstrated how conductive nano-filaments in amorphous titanium dioxide (TiO2) thin films could be utilized for resistive switching device applications. Yuanmin ...

WASHINGTON, D.C. Sept. 20, 2013 -- Carbon nanotubes' outstanding mechanical, electrical and thermal properties make them an alluring material to electronics manufacturers. However, until recently scientists believed that growing the high density of tiny graphene cylinders needed for many microelectronics applications would be difficult. Now a team from Cambridge University in England has devised a simple technique to increase the density of nanotube forests grown on conductive supports about five times over previous methods. The high density nanotubes might one day replace ...

CAMBRIDGE, Mass-- Cancer cells metastasize in several stages -- first by invading surrounding tissue, then by infiltrating and spreading via the circulatory system. Some circulating cells work their way out of the vascular network, eventually forming a secondary tumor. While the initial process by which cancer cells enter the bloodstream -- called intravasation -- is well characterized, how cells escape blood vessels to permeate other tissues and organs is less clear. This process, called extravasation, is a crucial step in cancer metastasis. Now researchers at MIT ...

Psychiatrists and psychologists have long understood that an individual's personality can define how he or she views the world around them, reacts to situations, and interacts with others. It now appears that personality traits can be linked to the frequency with which older adults use expensive health care services. A study, published today in the journal The Milbank Quarterly, finds that certain measurable personality characteristics can be correlated to health care consumption, in some instances increasing use high cost health care services such as emergency room ...

Three new species of tiny frogs from Papua New Guinea are described in the latest issue of Zookeys. Dr Fred Kraus, University of Michigan, who in 2011 in Zookeys described the world's smallest frogs Paedophryne dekot and Paedophryne verrucosa, now adds another 3 species from the genus Oreophryne to the remarkable diversity of this region. The three new species Oreophryne cameroni, Oreophryne parkopanorum and Oreophryne gagneorum are all rather minute, with total body lengths of around 20 mm. These tiny frogs, however are still substantially larger than the species that ...

The radar on the Tropical Rainfall Measuring Mission (TRMM) satellite captured an image of Supertyphoon Usagi near the end of a 24-hour period in which Usagi intensified by 65 knots. This is more than twice the commonly used 30-knot threshold for defining rapid intensification. The TRMM data was used to create a 3-D image. The data was collected at 1035 UTC/6:35 a.m. EDT on Thursday, September 19, 2013, when Usagi was at category 3 on the Saffir-Simpson hurricane intensity scale. A few hours later, Usagi completed its lightning-fast intensification to category 5, the ...

According to a recent study published by the National Science Foundation (NSF), businesses spent more on research and development (R&D) in 2011 than they did in 2010. Companies spent $294 billion on R&D performed in the United States during 2011, compared with $279 billion during 2010. Data are from the Business and R&D and Innovation Survey (BRDIS), which is co-sponsored by NSF and the U.S. Census Bureau. BRDIS revealed that during 2011, companies in manufacturing industries performed $201 billion, or 68 percent, of domestic R&D. Companies in nonmanufacturing industries ...

Boulder, Colo., USA -- The October 2013 Lithosphere is now online. Locations studied include the Central Iberian Massif in Spain; Arctic Alaska; the Wet Mountains of Central Colorado, USA; the Basgo Formation in northwest India; Crystal Geyser in southeastern Utah, USA; Knight Inlet in the southwestern Coast Mountains Batholith, British Columbia, Canada; and three crustal-scale shear zones in the western Canadian Shield of northern Saskatchewan. Lithosphere is published bimonthly in hardcopy; articles are posted online as they become available. Abstracts are online at ...

DALLAS -- Researchers at UT Southwestern Medical Center have identified a cellular switch that potentially can be turned off and on to slow down, and eventually inhibit the growth of the most commonly diagnosed and aggressive malignant brain tumor. Findings of their investigation show that the protein RIP1 acts as a mediator of brain tumor cell survival, either protecting or destroying cells. Researchers believe that the protein, found in most glioblastomas, can be targeted to develop a drug treatment for these highly malignant brain tumors. The study was published online ...