Παρασκευή, 16 Μαΐου 2014

ScienceDaily: Top Environment News

ScienceDaily: Top Environment 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.

Vet study reveals Salmonella's hideout strategy

Posted: 15 May 2014 01:38 PM PDT

A study reveals how some Salmonella bacteria hide from the immune system, allowing them to persist and cause systemic infection. The study addresses both questions, focusing on a component of the innate immune response called the inflammasome. Consisting of a complex of proteins that triggers the release of signaling molecules, the inflammasome serves to recruit other components of the immune system that can fight off the pathogen.

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.

Researching an endangered relationship: Bee species and their search for the flowering plants

Posted: 15 May 2014 12:41 PM PDT

The timing has been beautifully choreographed by nature. Rising spring temperatures prompt many bee species to begin their search for the flowering plants they depend on for food -- and which they propagate through pollination. But what would happen if this vital, mutually beneficial relationship goes out of synch due to climate change?

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.

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.

Synthetic biology still in uncharted waters of public opinion

Posted: 15 May 2014 09:33 AM PDT

A new set of focus groups found continued low awareness of synthetic biology, as well as concerns about specific applications. The focus group discussions also reinforce earlier findings that specific applications impact people's hopes and anxieties around synthetic biology. For example, medical applications including disease cures gained the most support in the focus groups, while the biological production of chemicals and food additives received little to no support. Participants focused their concern on unforeseen, unintended consequences that might occur from synthetic biology.

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.

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.

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.

Secret of radiation vulnerability revealed by research

Posted: 15 May 2014 08:33 AM PDT

The secret of radiation vulnerability has been revealed by a new study. The discovery can help both in predicting the consequences of irradiation and understanding the fundamental patterns of morphogenesis.

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.

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.

Customizing antibodies by learning from sharks

Posted: 15 May 2014 06:56 AM PDT

Genetically engineered antibodies are deployed successfully in cancer diagnostics and therapy. Therapeutic antibodies against Alzheimer's disease and multiple sclerosis are currently under development. An important criterion when designing suitable antibody fragments is their stability. Comparing the antibodies of sharks with those of humans, a team of researchers has discovered stabilizing mechanisms that can also be applied to optimize custom-tailored antibodies for medical applications.

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.

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.

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.

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."

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.

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