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‘Artificial Forest’ Nanosystem Mimics Photosynthesis, Researchers Say

Yale Environment 360 - Fri, 05/17/2013 - 00:10

U.S. scientists have developed what they say is the first integrated nanosystem capable of replicating the process of photosynthesis, a sort of “artificial forest” that could one day lead to the production of hydrogen that could be used to power fuel cells. Composed of nanowire structures — including silicon “trunks” and titanium oxide “branches” — the system mimics the role played by chloroplasts in promoting photosynthesis in green plants. By assembling the “trees” in a dense array, resembling a miniature forest, the network lowers sunlight reflection and provides more surface area for hydrogen-producing reactions, the scientists say. “We’ve integrated our nanowire nanoscale heterostructure into a functional system that mimics the integration in chloroplasts and provides a conceptual blueprint for better solar-to-fuel conversion efficiencies in the future,” said Peidong Yang, a chemist with the Lawrence Berkeley National Laboratory and co-author of the study, published in the journal NANO Letters. The lab of Daniel Nocera at Harvard University is doing related research into so-called artificial leaves.

Categories: Environmental News

In Post-Tsunami Japan, A Push To Rebuild Coast in Concrete

Yale Environment 360 - Thu, 05/16/2013 - 07:30

In the wake of the 2011 tsunami, the Japanese government is forgoing an opportunity to sustainably protect its coastline and is instead building towering concrete seawalls and other defenses that environmentalists say will inflict serious damage on coastal ecosystems. BY WINIFRED BIRD

Categories: Environmental News

Scientist’s U.S. Road Trip Reveals Higher Methane Emissions Than Previously Known

Yale Environment 360 - Thu, 05/16/2013 - 00:00

Methane measurements collected during a scientist’s road trip across the U.S. indicate that local emissions of the potent greenhouse gas are higher than previously known in many regions. Using a gas chromatograph mounted to the roof of a rented camper, Ira Leifer of the University of California, Santa Barbara, collected air samples from Florida to California, finding the highest methane concentrations in areas with significant refinery activity — such as Houston, Texas — and in a region of central California with oil and gas production. He found that methane concentrations exceeded the levels estimated by the U.S. Department of Energy, particularly in areas near industrial fossil fuel extraction sites. The results point to the importance of targeting these “fugitive” methane emissions in parallel with efforts to reduce CO2 emissions. Leifer's findings were published in the journal Atmospheric Environment.

Categories: Environmental News

Human stem cells created by cloning

Nature - Wed, 05/15/2013 - 20:00

Human stem cells created by cloning

Nature 497, 7449 (2013). http://www.nature.com/doifinder/10.1038/497295a

Author: David Cyranoski

Breakthrough sets up showdown with induced adult lines.

Categories: Literature

Glaciers on Everest Disappearing as Temperatures Rise, Snowfall Declines

Yale Environment 360 - Wed, 05/15/2013 - 10:33

The glaciers on Mount Everest and the surrounding region have shrunk by 13 percent in the last five decades as temperatures have risen and snowfall has declined in Pavel Novak that section of the Himalaya, according to a new study. Using satellite imagery and topographic maps, a team of scientists found that the majority of glaciers on Everest, the world’s tallest mountain, and in the surrounding Sagarmatha National Park are retreating at an accelerating rate. In the last 50 years, the snowline in the Everest region has shifted up by an average of 590 feet (180 meters), said Sudeep Thakuri, a Ph. D. student at the University of Milan and leader of the research team, which presented its findings at a conference in Cancún, Mexico. Because glaciers are melting faster than they are being replenished, researchers say, rock and debris that were previously hidden under snow are now exposed and absorbing heat.

Categories: Environmental News

Privacy in the digital age

Nature - Wed, 05/15/2013 - 00:00

Privacy in the digital age

Nature 497, 7449 (2013). doi:10.1038/497287a

The proposed European Data Protection Regulation will rightly preserve people’s privacy — but, without exceptions for scientific research, it could hinder or prevent medical discoveries.

Categories: Literature

Science in schools

Nature - Wed, 05/15/2013 - 00:00

Science in schools

Nature 497, 7449 (2013). doi:10.1038/497287b

The US National Center for Science Education teaches researchers how to fight for their cause.

Categories: Literature

Together we stand

Nature - Wed, 05/15/2013 - 00:00

Together we stand

Nature 497, 7449 (2013). doi:10.1038/497288a

To reach a sustainable future, we must merge economic and environmental agendas.

Categories: Literature

Driving students into science is a fool’s errand

Nature - Wed, 05/15/2013 - 00:00

Driving students into science is a fool’s errand

Nature 497, 7449 (2013). http://www.nature.com/doifinder/10.1038/497289a

Author: Colin Macilwain

If programmes to bolster STEM education are effective, they distort the labour market; if they aren’t, they’re a waste of money, argues Colin Macilwain.

Categories: Literature

Epidemiology: Unappreciated toll of toxic sites

Nature - Wed, 05/15/2013 - 00:00

Epidemiology: Unappreciated toll of toxic sites

Nature 497, 7449 (2013). doi:10.1038/497290a

Toxic-waste sites pose as big a health threat as malaria in some developing nations.Kevin Chatham-Stephens at the Icahn School of Medicine at Mount Sinai in New York and his colleagues produced a systematic assessment of the disease burden of toxic-waste sites in India (pictured),

Categories: Literature

Neuroscience: Cell transplants stem seizures

Nature - Wed, 05/15/2013 - 00:00

Neuroscience: Cell transplants stem seizures

Nature 497, 7449 (2013). doi:10.1038/497290b

Stem-cell therapy can reduce seizures in epileptic mice.Some forms of epilepsy are thought to be caused by dysfunctional cells in the hippocampus region of the brain. The affected cells, called inhibitory interneurons, help to regulate neural circuits. Robert Hunt, Scott Baraban and their colleagues

Categories: Literature

Addiction research: Drug vaccine blocks rat relapse

Nature - Wed, 05/15/2013 - 00:00

Addiction research: Drug vaccine blocks rat relapse

Nature 497, 7449 (2013). doi:10.1038/497290c

A vaccine stops heroin-addicted rats from seeking the drug.Earlier vaccines against heroin have faltered because the antibodies that they induce are easily overwhelmed by increased doses of the drug. Joel Schlosburg and his colleagues at the Scripps Research Institute in La Jolla, California, have

Categories: Literature

Climate science: More cyclones for Hawaiian Islands

Nature - Wed, 05/15/2013 - 00:00

Climate science: More cyclones for Hawaiian Islands

Nature 497, 7449 (2013). doi:10.1038/497290d

Climate change could double the number of tropical cyclones that storm into the Hawaiian Islands.Hiroyuki Murakami, then at the Meteorological Research Institute in Tsukuba, Japan, and his colleagues simulated tropical-cyclone patterns using several versions of a weather model, as well as predictions of sea-surface

Categories: Literature

Microbiology: Fast life in the urinary tract

Nature - Wed, 05/15/2013 - 00:00

Microbiology: Fast life in the urinary tract

Nature 497, 7449 (2013). doi:10.1038/497290e

Bacteria responsible for recurrent urinary-tract infections migrate from the gut.These infections, which affect up to one-quarter of women, are caused mostly by strains of the bacterium Escherichia coli that are thought to give up their adaptations to life in the gut for ones

Categories: Literature

Animal behaviour: Tree-loving lemur digs hole in winter

Nature - Wed, 05/15/2013 - 00:00

Animal behaviour: Tree-loving lemur digs hole in winter

Nature 497, 7449 (2013). doi:10.1038/497291a

Lemurs normally live in trees, but researchers have discovered that at least two species hibernate underground.Marina Blanco at the Duke Lemur Center in Durham, North Carolina, and her colleagues unearthed two species of eastern dwarf lemur (Cheirogaleus sibreei and C. crossleyi,

Categories: Literature

Palaeontology: Flow sorting for fossil pollen

Nature - Wed, 05/15/2013 - 00:00

Palaeontology: Flow sorting for fossil pollen

Nature 497, 7449 (2013). doi:10.1038/497291b

Unconventional use of a sorting technology could help palaeontologists to date lake sediments. This could enable better reconstruction of past environments and climates.Pollen grains, which can be used in carbon dating, are often the only organic matter found in abundance in lake sediments. However,

Categories: Literature

Cell biology: Sperm control DNA breaks

Nature - Wed, 05/15/2013 - 00:00

Cell biology: Sperm control DNA breaks

Nature 497, 7449 (2013). doi:10.1038/497291c

When dividing to produce mammalian sex cells, cells coordinate how DNA breaks occur.The cell-division process that forms these sex cells, which contain one set of chromosomes instead of the normal two, involves the swapping of bits of genetic material between matching pairs of chromosomes.

Categories: Literature

Zoology: Tongue spikes snare nectar

Nature - Wed, 05/15/2013 - 00:00

Zoology: Tongue spikes snare nectar

Nature 497, 7449 (2013). doi:10.1038/497291d

Hovering bats use barbed tongues to snare nectar from flowers.Cally Harper and her colleagues at Brown University in Providence, Rhode Island, used a high-speed video camera and post-mortem analyses to understand the mechanics of the eponymous organ of the Pallas's long-tongued bat (Glossophaga

Categories: Literature

Materials science: Holes help supercapacitor

Nature - Wed, 05/15/2013 - 00:00

Materials science: Holes help supercapacitor

Nature 497, 7449 (2013). doi:10.1038/497291e

Highly read on www.wiley.com in MarchA graphene-based material can store energy at seven times the density of commercial carbon-based products.Supercapacitors — which could be used to power electric vehicles — recharge and release energy faster than batteries, but their energy density is

Categories: Literature

Seven days: 10–16 May 2013

Nature - Wed, 05/15/2013 - 00:00

Seven days: 10–16 May 2013

Nature 497, 7449 (2013). http://www.nature.com/doifinder/10.1038/497292a

The week in science: Endangered ecosystems listed, GM patents protected, and wild poliovirus detected in Somalia.

Categories: Literature