Πέμπτη 5 Δεκεμβρίου 2013

ScienceDaily: Top Environment News

ScienceDaily: Top Environment News


Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey

Posted: 04 Dec 2013 03:24 PM PST

Biologists have observed two crocodilian species -- muggers and American alligators -- using twigs and sticks to lure birds, particularly during nest-building time.

Rising ocean acidification leads to anxiety in fish

Posted: 04 Dec 2013 03:22 PM PST

A new research study combining marine physiology, neuroscience, pharmacology, and behavioral psychology has revealed a surprising outcome from increases of carbon dioxide uptake in the oceans: anxious fish. Scientists have shown for the first time that rising acidity levels increase anxiety in juvenile rockfish, an important commercial species in California.

Multi-dog study points to canine brain's reward center

Posted: 04 Dec 2013 03:22 PM PST

After capturing the first brain images of two alert, unrestrained dogs last year, researchers have confirmed their methods and results by replicating them in an experiment involving 13 dogs. The research showed that most of the dogs had a positive response in the caudate region of the brain when given a hand signal indicating they would receive a food treat, as compared to a different hand signal for "no treat."

New fossil species found in Mozambique reveals new data on ancient mammal relatives

Posted: 04 Dec 2013 03:18 PM PST

In the remote province of Niassa, Mozambique, a new species and genus of fossil vertebrate was found. The species is a distant relative of living mammals and is approximately 256 million years old. This new species belongs to a group of animals called synapsids. Synapsida includes a number of extinct lineages that dominated the communities on land in the Late Permian (260-252 million years ago), as well as living mammals and their direct ancestors.

Early tree-dwelling bipedal human ancestor was similar to ancient apes and 'Lucy' but not living apes

Posted: 04 Dec 2013 03:12 PM PST

An analysis of the femur of one of the oldest human ancestors reveals the six-million-year-old "Millenium Man" was bipedal but lived in the trees. The research could provide additional insight to the origins of human bipedalism.

Humans threaten wetlands' ability to keep pace with sea-level rise

Posted: 04 Dec 2013 10:20 AM PST

Left to themselves, coastal wetlands can withstand rapid levels of sea-level rise. But humans could be sabotaging some of their best defenses, according to a new review.

Sea-level rise to drive coastal flooding, regardless of change in cyclone activity

Posted: 04 Dec 2013 10:20 AM PST

Though recent studies focus on climate change impacts on intensity and frequency of tropical cyclones, a new review shows that sea level rise and shoreline retreat are the two more certain factors expected to drive an increase in future flood risk.

Oldest hominin DNA sequenced: Mitochondrial genome of a 400,000-year-old hominin from Spain decoded

Posted: 04 Dec 2013 10:20 AM PST

Using novel techniques to extract and study ancient DNA researchers have determined an almost complete mitochondrial genome sequence of a 400,000-year-old representative of the genus Homo from Sima de los Huesos, a unique cave site in Northern Spain, and found that it is related to the mitochondrial genome of Denisovans, extinct relatives of Neandertals in Asia. DNA this old has until recently been retrieved only from the permafrost.

Industrial age helps some coastal regions capture carbon dioxide, surprise finding shows

Posted: 04 Dec 2013 10:09 AM PST

Coastal portions of the world's oceans, once believed to be a source of carbon dioxide to the atmosphere, are now thought to absorb as much as two-thirds more carbon than they emitted in the preindustrial age, researchers estimate.

The first decade: Team reports on US trials of bioenergy grasses

Posted: 04 Dec 2013 09:38 AM PST

The first long-term US field trials of Miscanthus x giganteus, a towering perennial grass used in bioenergy production, reveal that its exceptional yields, though reduced somewhat after five years of growth, are still more than twice those of switchgrass (Panicum virgatum), another perennial grass used as a bioenergy feedstock. Miscanthus grown in Illinois also outperforms even the high yields found in earlier studies of the crop in Europe, the researchers found.

First evidence of primates regularly sleeping in caves

Posted: 04 Dec 2013 09:37 AM PST

Scientists have discovered that some ring-tailed lemurs in Madagascar regularly retire to limestone chambers for their nightly snoozes, the first evidence of the consistent, daily use of the same caves and crevices for sleeping among the world's wild primates.

Multiple mates worth the risk for female prairie dogs

Posted: 04 Dec 2013 09:37 AM PST

Mating with more than one male increases reproductive success for female prairie dogs, despite an increase in risks such as increased susceptibility to predation and increased exposure to diseases and parasites. So why would a female prairie dog take the risk? The answer is simple: female prairie dogs that mate with two or more males rear more offspring than those that mate with only one.

No blue skies for mice: Scientist study differential distribution of photoreceptors in retina of mice

Posted: 04 Dec 2013 09:36 AM PST

Guppies, hyenas and mice share one particular retinal specialization in their eye: Photoreceptors ("cones") sensitive to 'green' light are largely located in the top half of the eye, whereas cones sensitive to 'blue' light dominate the bottom half. Scientists have investigated this retinal specialization in mice, showing that the apparent match between 'color' and differential cone distribution brings the animals no advantage.

Researchers find shape-shifting stops migrating cancer cells

Posted: 04 Dec 2013 09:32 AM PST

Like a car with a front and back end, a steering mechanism and an engine to push it forward, cancer cells propel themselves through normal tissues and organs to spread cancer throughout the body. Researchers, however, have managed to turn these cells into shapes like a round fried egg and an exaggerated starfish that sticks out in many directions — both of which cannot move.

Virtual wall could stop spread of oil and help build invisible barrier for oil spills

Posted: 04 Dec 2013 08:20 AM PST

A new technique forms a virtual wall for oily liquids that will help confine them to a certain area, aiding researchers who are studying these complex molecules. This development will have future implications in the guided delivery of oil and effective blockage of oil spreading.

Turning waste into power with bacteria and loofahs

Posted: 04 Dec 2013 08:20 AM PST

Loofahs, best known for their use in exfoliating skin to soft, radiant perfection, have emerged as a new potential tool to advance sustainability efforts on two fronts at the same time: energy and waste. A new study describes the pairing of loofahs with bacteria to create a power-generating microbial fuel cell.

While the Arctic Ocean is largely a carbon sink, parts are also a source of atmospheric carbon dioxide

Posted: 04 Dec 2013 08:20 AM PST

While the Arctic Ocean is largely a carbon sink, researchers find parts are also a source of atmospheric carbon dioxide. The Arctic Ocean as a whole seems to be storing more carbon than in previous years but the increase in the carbon sink may not be as large as scientists had previously thought.

Scientists unearth secrets of Périgord truffles, the culinary 'black diamond'

Posted: 04 Dec 2013 08:20 AM PST

Just in time for the holidays when cooks in France and elsewhere will be slipping bits of the coveted black Périgord truffle under their turkeys' skin for a luxurious flavor, scientists are revealing the secrets that give the culinary world's "black diamond" its unique, pungent aroma. Their study could lead to better ways to determine the freshness and authenticity of the pricey delicacy.

Silkworms spin colored silks while on a 'green' dyed-leaf diet

Posted: 04 Dec 2013 08:20 AM PST

For some 5,000 years, cultivated silkworms have been spinning luxurious white silk fibers destined for use in the finest clothing. But current dyeing practices produce wastewater that contains potentially harmful toxins, so scientists are turning to a new, "greener" dyeing method in which they coax already-colored fibers from the caterpillars by feeding them dyed leaves.

Fossils clarify the origins of wasps and their kin: Alderfly ancestors, snakefly cousins

Posted: 04 Dec 2013 08:20 AM PST

The insect order Hymenoptera -- wasps, bees, ants and relatives -- is the third most diverse animal group, but its origin remains controversial. Fossils from Permian beds of Russia demonstrate that the wasp lineage is not as ancient as held before, and is related to alderflies and snakeflies. The wasp and snakefly ancestors were very small, indicating that these lineages have passed through a "miniaturization bottleneck."

Fruit pest targeted by genomic research

Posted: 04 Dec 2013 06:16 AM PST

Genome sequencing of the spotted wing drosophila, a major fruit pest, is expected to accelerate basic and applied research, leading to better monitoring and control strategies for the insect.

First global snapshot of key coral reef fishes: Fishing has reduced vital seaweed eaters by more than 50 percent

Posted: 04 Dec 2013 06:16 AM PST

Biologists have reported on the impact of fishing on a group of fish known to protect the health of coral reefs. The report offers key data for setting management and conservation targets to protect and preserve fragile coral reefs.

How to change cell types by flipping a single switch

Posted: 04 Dec 2013 06:16 AM PST

With few exceptions, cells don't change type once they have become specialized -- a heart cell, for example, won't suddenly become a brain cell. However, new findings have identified a method for changing one cell type into another in a process called forced transdifferentiation.

Five distinct humpback whale populations identified in North Pacific

Posted: 04 Dec 2013 06:16 AM PST

The first comprehensive genetic study of humpback whale populations in the North Pacific Ocean has identified five distinct populations -- at the same time a proposal to designate North Pacific humpbacks as a single "distinct population segment" is being considered under the Endangered Species Act.

More extreme weather events likely: Climate projections of unparalleled accuracy for the whole of Europe

Posted: 04 Dec 2013 06:11 AM PST

Scientists have analyzed climate projections for the whole of Europe at an unprecedented resolution of 12 km, by downscaling the global simulations carried out for the 5th IPCC report. These simulations for the 21st century now provide a much more detailed representation of local phenomena and extreme events. Initial analyses confirm that there will be a significant increase in the frequency of extreme events, such as heavy rainfall, heatwaves and droughts.

Ocean crust could store many centuries of industrial carbon dioxide

Posted: 04 Dec 2013 06:11 AM PST

Researchers have identified regions beneath the oceans where the igneous rocks of the upper ocean crust could safely store very large volumes of carbon dioxide. The burning of fossil fuels such as coal, oil, and natural gas has led to dramatically increasing concentrations of CO2 in the atmosphere causing climate change and ocean acidification. Although technologies are being developed to capture CO2 at major sources such as power stations, this will only avoid further warming if that CO2 is then safely locked away from the atmosphere for centuries.

Harlequin ladybugs escape enemies while native species succumb

Posted: 04 Dec 2013 06:11 AM PST

The astonishing success of the alien invasive harlequin ladybird (ladybug) in Britain has given a team of scientists a unique opportunity to investigate a key ecological theory – the Enemy Release Hypothesis.

Rapid climate changes at end of last glaciation, but with 120 year time lag

Posted: 04 Dec 2013 06:09 AM PST

Regional climate changes can be very rapid. Geoscientists now report that such a rapid climate change occurred in different regions with a time difference of 120 years. Investigation in the west German Eifel region and in southern Norway demonstrated that at the end of the last glaciation about 12,240 years before present climate became warmer, first recognized in the Eifel region and 120 years later in southern Norway. Nonetheless, the warming was equally rapid in both regions.

Amoeboid swimming: Crawling in a fluid

Posted: 04 Dec 2013 06:09 AM PST

Researchers have developed a particularly simple model that reproduces the swimming mechanism of amoebas. They show that, by changing shape, these single cell organisms propel themselves forward in a viscous fluid at the same speed as when they crawl on a solid substrate. The way microorganisms swim is fundamentally different to that of fish since, at their scale, viscosity effects dominate and make fins totally inefficient.

New insights into cancer evolution help define screening window of opportunity

Posted: 03 Dec 2013 04:10 PM PST

Researchers discover that cancer develops a few years after cells undergo drastic mutations, contrary to common belief.

Development near Oregon, Washington public forests

Posted: 03 Dec 2013 01:17 PM PST

Private development along the edges of most public forests in Oregon and Washington more than doubled since the 1970s, a new study has found.

Membrane enzymes 'stop and frisk' proteins indiscriminately

Posted: 03 Dec 2013 01:15 PM PST

For what is believed to be the first time, researchers have illuminated the inner workings of an important class of enzymes located inside the outer envelopes of cells. Much to their surprise, they report, these protein cutters, called rhomboid proteases, are entirely different than nearly every other type of enzyme studied, showing no attraction to the proteins they cut and being extremely slow in making their cuts.

Precipitation declines in Pacific Northwest mountains

Posted: 03 Dec 2013 08:03 AM PST

Scientists previously attributed streamflow declines in the Pacific Northwest USA to warming temperatures based on data collected from long-term monitoring stations located in lower elevation valleys. In this new study, scientists monitored and observed declines in precipitation resulting from decreases in westerly winds in the mountains where the elevation is much higher concluding this may compound the changes in streamflow. This finding is significant since mountains are a primary water source for this region.

New research will allow more reliable dating of major past events

Posted: 03 Dec 2013 08:03 AM PST

Academics have developed a new internationally agreed radiocarbon calibration curve which will allow key past events to be dated more accurately.

Tuberculosis: Nature has double-duty antibiotic up her sleeve

Posted: 03 Dec 2013 08:03 AM PST

Technology has made it possible to synthesize increasingly targeted drugs. But scientists still have much to learn from Mother Nature. Pyridomycin, a substance produced by non-pathogenic soil bacteria, has been found to be a potent antibiotic against a related strain of bacteria that cause tuberculosis. Its complex three-dimensional structure allows it to act simultaneously on two parts of a key enzyme in the tuberculosis bacillus, and in doing so, dramatically reduce the risk that the bacteria will develop multiple resistances.

How onions recognize when to bulb

Posted: 03 Dec 2013 06:16 AM PST

New research from New Zealand identifies the gene that controls onion bulb development will help to breed new varieties tailored to grow in specific conditions.

Culling vampire bats to stem rabies in Latin America can backfire

Posted: 02 Dec 2013 01:21 PM PST

Culling vampire bat colonies to stem the transmission of rabies in Latin America does little to slow the spread of the virus and could even have the reverse effect.

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