The present rate of greenhouse carbon dioxide emissions through fossil fuel burning is higher than that associated with an ancient episode of severe global warming, according to new research. The findings are published online this week by the journal Nature Geoscience.

Around 55.9 million years ago, the Earth experienced a period of intense global warming known as the Palaeocene–Eocene Thermal Maximum (PETM), which lasted for around 170,000 years. During its main phase, average annual temperatures rose by around 5°C.

A team of researchers from Columbia Engineering, the Italian National Research Council, Princeton University, University of Missouri, and University of Nijmegen (Netherlands) has developed an artificial semiconductor structure that has superimposed a pattern created by advanced fabrication methods that are precise at the nanometer scale. The pattern is similar to the honeycomb lattice that occurs in graphene. The device, called "artificial graphene" (AG), simulates quantum behavior of strongly interacting electrons.

Lowering phosphate intake in humans can reduce heart disease, according to research by experts at the University of Sheffield.

This is the first time the connection between a high phosphate diet and atherosclerosis - the cause of heart disease - has been proven. The findings have been published in Arteriosclerosis, Thrombosis and Vascular Biology (2 June 2011).

The decision of the German government to phase out nuclear power by 2022 has reopened an energy debate that has far wider implications than Germany or Japan, which is still coming to terms with events at the damaged Fukushima plant.

This virtual issue, published by the SETAC journal Environmental Toxicology and Chemistry adds to that debate by exploring the ecological effects of radiation, using research from the Chernobyl disaster.

A dark-matter experiment deep in the Soudan mine of Minnesota now has detected a seasonal signal variation similar to one an Italian experiment has been reporting for more than a decade.

The new seasonal variation, recorded by the Coherent Germanium Neutrino Technology (CoGeNT) experiment, is exactly what theoreticians had predicted if dark matter turned out to be what physicists call Weakly Interacting Massive Particles (WIMPs).

NASA's Terra Satellite, the GOES-13 and GOES-11 satellites all captured images of the ash plume from southern Chile's Puyehue-Cordón Volcano this week. The volcano is located in Puyehue National Park in the Andes of Ranco Province of Chile.

OAK RIDGE, Tenn., June 6, 2011 -- Neutron analysis of the atomic dynamics behind thermal conductivity is helping scientists at the Department of Energy's Oak Ridge National Laboratory gain a deeper understanding of how thermoelectric materials work. The analysis could spur the development of a broader range of products with the capability to transform heat to electricity.

A lower dose of zoledronic acid than currently recommended for prevention of bone fractures due to osteoporosis decreases bone resorption and increases bone density, and may be effective in reducing the risk of osteoporotic fractures, a study finds. The new research findings will be presented Monday at The Endocrine Society's 93rd Annual Meeting in Boston.

A new study comparing lifelong obesity with the weight fluctuations of "yo-yo dieting" suggests it is better to attempt to lose weight despite repeated failures at keeping the weight off than to not diet and remain obese. The results will be presented Monday at The Endocrine Society's 93rd Annual Meeting in Boston.

PASADENA, Calif.—When geologists survey an area of land for the potential that gas or petroleum deposits could exist there, they must take into account the composition of rocks that lie below the surface. Take, for instance, sandstone—a sedimentary rock composed mostly of weakly cemented quartz grains. Previous research had suggested that compaction bands—highly compressed, narrow, flat layers within the sandstone—are much less permeable than the host rock and might act as barriers to the flow of oil or gas.

Researchers now understand more about why platinum is so efficient at producing power in hydrogen fuel cells.

"Understanding platinum's properties for speeding up chemical reactions will potentially enable scientists to create significantly cheaper synthetic or metal alloy alternatives for use in sustainable devices like fuel cells," says Gregory Jerkiewicz, a professor in the Department of Chemistry who led the groundbreaking study.

This world-first has its origins in Hamburg. Jörg Weißmüller, a materials scientist at both the Technical University of Hamburg and the Helmholtz Center Geesthacht, has carried out research on this groundbreaking development, working in cooperation with colleagues from the Institute for Metal Research in Shenyang, China.

The human impact on the environment, especially through the release of greenhouse gases, is an area of controversy in public understanding of climate change, and is important for predicting future changes. Many studies into our collective impact use climate models to understand the causes of observed climate changes, both globally and in specific regions.

The tropics and much of the Northern Hemisphere are likely to experience an irreversible rise in summer temperatures within the next 20 to 60 years if atmospheric greenhouse gas concentrations continue to increase, according to a new climate study by Stanford University scientists. The results will be published later this month in the journal Climatic Change.

The ALPHA Collaboration, an international team of scientists working at CERN in Geneva, Switzerland, has created and stored a total of 309 antihydrogen atoms, some for up to 1,000 seconds (almost 17 minutes), with an indication of much longer storage time as well.

ALPHA announced in November, 2010, that they had succeeded in storing antimatter atoms for the first time ever, having captured 38 atoms of antihydrogen and storing each for a sixth of a second. In the weeks following, ALPHA continued to collect anti-atoms and hold them for longer and longer times.