WWWBiology

Scientists from Yale and UCL have identified a new mechanism that regulates VEGFR2 transport in vascular cells, opening new therapeutic opportunities for developing drugs to stimulate or inhibit blood vessel formation.

Arteries form in utero and during development, but can also form in adults when organs become deprived of oxygen — for example, after a heart attack. The organs release a molecular signal called VEGF. Working with mice, the Yale-UCL team discovered that in order for VEGF-driven artery formation to occur, VEGF must bind with two molecules known as VEGFR2 and NRP1, and all three must work as a team.

The researchers examined mice that were lacking a particular part of the NRP1 molecule that transports VEGF and VEGFR2 to a signaling center inside blood vessel walls. They observed that the internal organs of these mice contained poorly constructed arterial branches. Further, the mice where unable to efficiently repair blood vessel blockage through the formation of new arteries.

“We have identified an important new mechanism that regulates VEGFR2 transport in vascular cells,” said corresponding author Michael Simons, professor of medicine and cell biology, and director of the cardiovascular research center at Yale School of Medicine. “This opens new therapeutic opportunities for developing drugs that would either stimulate or inhibit blood vessel formation — important goals in cardiovascular and anti-cancer therapies, respectively.”

The following topics are covered:

Aerospace, Anthropology, Astrobiology, Astronomy, Astrophysics, Biochemistry, Bioengineering, Biology, Biotechnology, Chemistry, Civil Engineering, Cognitive Science, Computers, Cosmology, Dentistry, Electrical Engineering, Engineering, Environment, Future, General Science, Geoscience, Machine Learning, Material Science, Mathematics, Mechanical Engineering, Medicine, Metallurgy, Mining, Nanotechnology, Oceanography, Philosophy, Physics, Physiology, Robotics, and Sociology.

Lectures are in Playlists and are alphabetically sorted with thumbnail pictures. No fee, no registration required - learn at your own pace. Certificates can be arranged with presenting universities.

NOTE: To subscribe to the RSS feed of Amazing Science, copy http://www.scoop.it/t/amazing-science/rss.xml into the URL field of your browser and click "subscribe".

FREE CODE for 2 days at codeschool: http://go.codeschool.com/PzsLdA

Biomass as a source for power and heat generation promises to play an important role in the energy mix of the future.

Xylella fastidiosa  is not your ordinary kind of bug. It made it to the list of the most wanted plant pathogenic bacteria in 2012! This is well deserved: X. fastidiosa can infect over a hundred species (grapevine, oleander, citrus, almonds,…), and it causes severe symptoms that can kill the infected plant. TheXylella bacteria colonize the xylem vessels, and by doing so they block the transport of water in the plant. The water-deprived leaves dry and scorch, until finally they drop to the ground.

Check also the video on the glassy-winged sharpshooter leafhopper.

Want to address world hunger — not to mention climate change, poverty and pollution? Here's how taking a more natural approach to agriculture can benefit everyone and everything from the soil up.

A new environmental threat map of the Great Lakes shows cumulative stress is highest in Lakes Ontario, Erie and Michigan, especially along the shoreline and near busy harbors. Source: Great Lakes Environmental Assessment and Mapping (GLEAM) Project.

Artisanal gold mining, the largest source of global mercury pollution in small-scale operations, is the only source of income for as many as 15 million people in 70 countries, mostly poor ones.

As the world is transfixed by a new H7N9 bird flu virus spreading through China, a study reminds us that a different avian influenza — H5N1 — still poses a pandemic threat.

A team of scientists in China has created hybrid viruses by mixing genes from H5N1 and the H1N1 strain behind the 2009 swine flu pandemic, and showed that some of the hybrids can spread through the air between guinea pigs.

Flu hybrids can arise naturally when two viral strains infect the same cell and exchange genes. This process, known as reassortment, produced the strains responsible for at least three past flu pandemics, including the one in 2009.

There is no evidence that H5N1 and H1N1 have reassorted naturally yet, but they have many opportunities to do so. The viruses overlap both in their geographical range and in the species they infect, and although H5N1 tends mostly to swap genes in its own lineage, the pandemic H1N1 strain seems to be particularly prone to reassortment.

“If these mammalian-transmissible H5N1 viruses are generated in nature, a pandemic will be highly likely,” says Hualan Chen, a virologist at the Harbin Veterinary Research Institute of the Chinese Academy of Sciences, who led the study.

“It's remarkable work and clearly shows how the continued circulation of H5N1 strains in Asia and Egypt continues to pose a very real threat for human and animal health,” says Jeremy Farrar, director of the Oxford University Clinical Research Unit in Ho Chi Minh City, Vietnam.

Chen's results are likely to reignite the controversy that plagued the flu community last year, when two groups found that H5N1 could go airborne if it carried certain mutations in a gene that produced a protein called haemagglutinin (HA). Following heated debate over biosecurity issues raised by the work, the flu community instigated a voluntary year-long moratorium on research that would produce further transmissible strains. Chen’s experiments were all finished before the hiatus came into effect, but more work of this nature can be expected now that the moratorium has been lifted.

“I do believe such research is critical to our understanding of influenza,” says Farrar. “But such work, anywhere in the world, needs to be tightly regulated and conducted in the most secure facilities, which are registered and certified to a common international standard.”

Virologists have created H5N1 reassortants before. One study found that H5N1 did not produce transmissible hybrids when it reassorts with a flu strain called H3N2. But in 2011, Stacey Schultz-Cherry, a virologist at St. Jude Children's Research Hospital in Memphis, Tennessee, showed that pandemic H1N1 becomes more virulent if it carries the HA gene from H5N1.

Chen’s team mixed and matched seven gene segments from H5N1 and H1N1 in every possible combination, to create 127 reassortant viruses, all with H5N1’s HA gene. Some of these hybrids could spread through the air between guinea pigs in adjacent cages, as long as they carried either or both of two genes from H1N1 called PA and NS. Two further genes from H1N1, NA and M, promoted airborne transmission to a lesser extent, and another, the NP gene, did so in combination with PA.

UCSF scientists controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signaling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory. Other researchers had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.

Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease, according to Scott C. Baraban, PhD, who holds the William K. Bowes Jr. Endowed Chair in Neuroscience Research at UCSF and led the new study. In many types of epilepsy, he said, current drugs have no therapeutic value at all.

"Our results are an encouraging step toward using inhibitory neurons for cell transplantation in adults with severe forms of epilepsy," Baraban said. "This procedure offers the possibility of controlling seizures and rescuing cognitive deficits in these patients."

In the UCSF study, the transplanted inhibitory cells quenched this synchronous, nerve-signaling firestorm, eliminating seizures in half of the treated mice and dramatically reducing the number of spontaneous seizures in the rest. Robert Hunt, PhD, a postdoctoral fellow in the Baraban lab, guided many of the key experiments.

he mouse model of disease that Baraban's lab team worked with is meant to resemble a severe and typically drug-resistant form of human epilepsy called mesial temporal lobe epilepsy, in which seizures are thought to arise in the hippocampus. In contrast to transplants into the hippocampus, transplants into the amygdala, a brain region involved in memory and emotion, failed to halt seizure activity in this same mouse model, the researcher found.

Temporal lobe epilepsy often develops in adolescence, in some cases long after a seizure episode triggered during early childhood by a high fever. A similar condition in mice can be induced with a chemical exposure, and in addition to seizures, this mouse model shares other pathological features with the human condition, such as loss of cells in the hippocampus, behavioral alterations and impaired problem solving.

Eye color is much more complicated than is usually taught in high school (or presented in The Tech’s eye color calculator).  There we learn that two genes influence eye color. One gene comes in two versions, brown (B) and blue (b).  The other gene comes in green (G) and blue (b).  All eye color and inheritance was thought to be explained by this simple model.  Except of course for the fact that it is obviously incomplete.

The model cannot, for example, explain how blue eyed parents can have a brown eyed child.  Yet this can and does happen (although it isn’t common).   

New research shows that the first gene is actually two separate genes, OCA2 and HERC2.  In other words, there are two ways to end up with blue eyes.  

Normally this wouldn’t be enough to explain how blue eyed parents can have a brown eyed child.  Because of how eye color works (see below), if one gene can cause brown eyes, it would dominate over another that causes blue.  In fact, that is what happens with green eyes in the older model.  The brown gene dominates over the green one resulting in brown eyes.

The key is that if someone makes a lot of pigment in the front part of their eye, they have brown eyes.  And if they make none there, they have blue.

Part of the pigment making process involves OCA2 and HERC2.  A working HERC2 is needed to turn on OCA2 and OCA2 helps to actually get the pigment made.  They need each other to make pigment.

So someone with only broken HERC2 genes will have blue eyes no matter what OCA2 says.  This is because the working OCA2 can't be turned on so no pigment gets made.

And the opposite is true as well.  Someone with broken OCA2 genes will have blue eyes no matter what the HERC2 genes are.  Turning on a broken pigment making gene still gives you no pigment.  You need a working HERC2 and a working OCA2 to have brown eyes.

Because the two genes depend on each other, it is possible for someone to actually be a carrier of a dominant trait like brown eyes.  And if two blue eyed parents are carriers, then they can have a brown eyed child.

By Douglas MainLiveScience
Both fishermen and fish species have benefited from "no-take" protections at a marine reserve in the Florida Keys, according to a government report.

An unusual event playing out high in the atmosphere above the Arctic Circle is setting the stage for what could be weeks upon weeks of frigid cold across wide swaths of the U.S.

When the sudden stratospheric warming event began in early January, that signaled to weather forecasters that a cool down was more likely to occur by the end of the month, since it usually takes many days for developments in the stratosphere to affect weather in the troposphere, and vice versa. As the polar stratosphere warms, high pressure builds over the Arctic, causing the polar jet stream to weaken. At the same time, the midlatitude jet stream strengthens, while also becoming wavier, with deeper troughs and ridges corresponding to more intense storms and high pressure areas. In fact, sudden stratospheric warming events even make so-called “blocked” weather patterns more likely to occur, which tilts the odds in favor of the development of winter storms in the U.S. and Europe.

The graph shows the evolution of the stratospheric warming event. The contours show absolute heights and the shading are height anomalies in the middle stratosphere, or about 16 miles above the surface. The height anomalies are a good proxy for temperature anomalies in the stratosphere with red representing high heights or warm temperatures and blue low heights or cold temperatures. You can see at the beginning of the loop a cohesive polar vortex along the coast of Northern Eurasia and then this area of higher heights or warm temperaturs rush poleward from Siberia into the polar vortex splitting it into two pieces, one over Eurasia and one over North America. The dramatic rise in heights or temperatures over the Pole is the sudden stratospheric warming. The result is that pieces of the polar vortex move equatorward and with it the associated cold temperatures. Usually something similar occurs in the troposphere in the ensuing weeks.

Tree lovers can add yet another pest to their list of worries. This time, it’s a beetle carrying an insidious fungus that can kill black walnut trees. Eight walnut twig beetles were found in traps set by state forestry and agriculture officials at a wood-processing business in Butler County in southwestern Ohio. Walnut products there have been quarantined.

“We definitely have a lot of walnut in Ohio, and it’s a very valuable species that we’re trying to protect,” said Dan Kenny, acting assistant chief of the Ohio Department of Agriculture’s plant health division. “We haven’t dealt with this pest before. There are a lot of questions out there, because it’s really a new discovery.” Although officials found beetles, they haven’t yet found any trees infested with the fungus that causes thousand cankers disease.

On October 25, 2012, the world watched as Hurricane Sandy swept up the east coast. Over these past few years, we have seen storm after storm leave our homes battered, our possessions ruined, and our towns and cities without power for weeks on end.

Biogen Ltd., a U.K. developer of plants that generate electricity from food waste, plans to start building four to five facilities this year as rising landfill taxes increases the costs of burying waste underground.

Information Services for Seed Professionals - The Best Place on the Web for Seed Professionals

A potent toxin in algal blooms may be causing drunken squid to fling themselves ashore to die.

Thousands of jumbo squid have beached themselves on central California shores this week, committing mass "suicide." But despite decades of study into the phenomenon in which the squid essentially fling themselves onto shore, the cause of these mass beachings have been a mystery.

But a few intriguing clues suggest poisonous algae that form so-called red tides may be intoxicating the Humboldt squidand causing the disoriented animals to swim ashore in Monterey Bay, said William Gilly, a marine biologist at Stanford University's Hopkins Marine Station in Pacific Grove, California.

Each of the strandings has corresponded to a red tide, in which algae bloom and release an extremely potent brain toxin, Gilly said. This fall, the red tides have occurred every three weeks, around the same time as the squid beachings, he said.