Category: Da Brayn

Scientists at Duke University say the world is on the brink of its sixth great extinction

On By A.P.In Climate Change, Da Brayn, Duke University, extinction, Mass Extinction, Science, Stuart Pimm, The FutureLeave a comment

Is the end near? Scientists at Duke University say the world is on the brink of its sixth great extinction, since certain species of plants and animals are now dying out at least 1,000 times faster than they did before humans came into existence.

The study, published Thursday in the journal Science, measured the the rate at which species are disappearing from Earth. In 1995, the researchers found that the pre-human rate of extinctions was roughly 1. Now, that rate is about 100 to 1,000.

Stuart Pimm, the study’s lead author, said habitat loss is mostly to blame for the increasing death rates. As humans continue to alter and destroy more land, animals and plants are increasingly being displaced from their natural habitats. Climate change is also a factor, he added.

“Whether we avoid it or not will depend on our actions,” Pimm warned.

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

http://theweek.com/article/index/262400/speedreads-earth-is-nearing-sixth-great-extinction-alarming-survey-says#axzz33DjJqxZg

Evolution silences crickets in Hawaii

On By A.P.In cricket, Current Biology, Da Brayn, Evolution, Hawaii, Nathan Bailey, Nature, StanfordLeave a comment

Scientists investigating the silence of the crickets in Hawaii have uncovered a bizarre evolutionary story that is part horror movie, part Cyrano de Bergerac.

In the most recent edition of the journal Current Biology, researchers from Scotland’s University of St. Andrews report on the separate but nearly simultaneous quieting of chirping crickets on Kauai and Oahu.

As lead researcher Nathan Bailey explained, Hawaii crickets appear to have abandoned their chirplike mating songs to avoid parasitoid flies. The flies, which are attracted to male cricket song, would lay larvae that would then burrow into the host crickets, killing them within a week.

Adaptive crickets survived and reproduced by silencing their own songs but positioning themselves — like Christian to Cyrano — next to crickets who continued to use their chirps to woo female crickets.

The silent flatwing crickets are present on both Oahu and Kauai. At first, Bailey and his team believed that a single population of silent crickets evolved on one island and spread to the other. However, further investigation made it clear that the crickets came from separate populations but adopted the same trait around the same time.

“This is an exciting opportunity to detect genomic evolution in real time in a wild system, which has usually been quite an challenge owing to the long timescales over which evolution acts,” Bailey said in a release. “With the crickets, we can act as relatively unobtrusive observers while the drama unfolds in the wild.”

http://www.staradvertiser.com/news/breaking/20140531_Evolution_silences_some_isle_cricket_populations.html?mobile=true

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

Physicists discover a surprisingly straightforward way to turn light into matter

On By A.P.In Albert Einstein, Breit and Wheeler, Da Brayn, Einstein, hohlraum, Imperial College London, Jonathan Webb, Nature Photonics, Oliver Pike, photon, physics, Science, Sir Peter Knight, Steven RoseLeave a comment

By Jonathan Webb

The design, published in Nature Photonics, adapts technology used in fusion research.

Several locations could now enter a race to convert photons into positrons and electrons for the very first time.

This would prove an 80-year-old theory by Breit and Wheeler, who themselves thought physical proof was impossible.

Now, according to researchers from Imperial College London, that proof is within reach.

Prof Steven Rose and his PhD student, Oliver Pike, told the BBC it could happen within a year.

“With a good experimental team, it should be quite doable,” said Mr Pike.

If the experiment comes to fruition, it will be the final piece in a puzzle that began in 1905, when Einstein accounted for the photoelectric effect with his model of light as a particle.

Several other basic interactions between matter and light have been described and subsequently proved by experiment, including Dirac’s 1930 proposal that an electron and its antimatter counterpart, a positron, could be annihilated upon collision to produce two photons.

Breit and Wheeler’s theoretical prediction of the reverse – that two photons could crash together and produce matter (a positron and an electron) – has been difficult to observe.

“The reason this is very hard to see in the lab is that you need to throw an awful lot of photons together – because the probability of any two of them interconverting is very low,” Prof Rose explained.

His team proposes gathering that vast number of very high-energy photons by firing an intense beam of gamma-rays into a further cloud of photons, created within a tiny, gold-lined cylinder.

That cylinder is called a “hohlraum”, German for “hollow space”, because it contains a vacuum, and it is usually used in nuclear fusion research. The cloud of photons inside it is made from extraordinarily intense X-rays and is about as hot as the Sun.

Hitting this very dense cloud of photons with the powerful gamma-ray beam raises the probability of collisions that will make matter – and history.

“It’s pretty amazing really,” said Mr Pike. He says it took some time to realise the value of the scheme, which he and two colleagues initially jotted down on scrap paper over several cups of coffee.

“For the first 12 hours or so, we didn’t quite appreciate its magnitude.”

But their subsequent calculations showed that the design, theoretically at least, has more than enough power to crack the challenge set by Breit and Wheeler in the 1930s.

“All the ingredients are there,” agrees Sir Peter Knight, an emeritus professor at Imperial College who was not involved in the research but describes it as a “really clever idea”.

“I think people will seriously start to have a crack at this,” Prof Knight told BBC News, though he cautioned that there were a lot of things to get right when putting the design into practice.

“If it’s done in a year, then they’ve done bloody well! I think it might take a bit longer.”

Some healthy scientific competition may speed up the process.

There are at least three facilities with the necessary equipment to test out the new proposal, including the Atomic Weapons Establishment in Oldham.

“The race to carry out and complete the experiment is on,” said Mr Pike.

http://www.bbc.com/news/science-environment-27470034

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

New research shows that blood from young mice reverses aging in brain and muscle

On By A.P.In adult neurogenesis, aged brain, ageing, aging, Amy Wagers, Atlas Venture, Carolyn Y. Johnson, Da Brayn, Dr. Lee Rubin, GDF11, Harvard Medical School, Harvard University, Medicine, muscle, muscle bulk, muscle growth, muscle wasting, parabiosis, Richard T. Lee, San Francisco, Saul Villeda, ScienceLeave a comment

In a trio of studies published Sunday, scientists reported that they reversed aging in the muscles and brains of old mice — simply by running the blood of young mice through their veins.

The papers, from two independent groups in Cambridge and California, used different approaches to begin to unravel the rejuvenating effects of young animals’ blood, in the hopes of eventually developing a therapy that could be tested in people.

Researchers at Harvard University administered a protein found in young blood to older mice, and found that treated mice could run longer on a treadmill and had more branching blood vessels in their brains than untreated mice. A group led by a University of California, San Francisco researcher identified a molecular switch in a memory center of the brain that appears to be turned on by blood from young mice.

“These are the tissues that are really affected by advancing age. Changes in these tissues are responsible for the changes that people worry about the most — loss of cognition and loss of independent function,” said Amy Wagers, a professor of stem cell and regenerative biology at Harvard University involved in two of the studies.

Wagers said many questions remain about the mechanism of the protein and what the best therapeutic strategy might be, but she is already working to commercialize the protein discovery. The same substance is found in human blood.

Outside scientists cautioned that the findings are limited to one strain of mice and that it is not yet clear that something so simple would have dramatic anti-aging effects in people.

The new studies build on a decade of research that showed that young blood can have a rejuvenating effect on older mice. When scientists stitched together the circulatory systems of pairs of old and young mice, in a procedure called parabiosis, they found beneficial effects on the cells of the spinal cord, muscles, brain, and liver of the older animals. The next question was why — which of the many substances floating around in blood were responsible for the changes, and how did it work?

Last year, Wagers and another Harvard stem cell scientist, Dr. Richard T. Lee, found that a protein called GDF11 could cause a mouse heart thickened with age to revert to a youthful state. No one knew, however, whether the effect was specific to the heart, or would apply to aging in other tissues. Two of the new papers, published online by the journal Science, extend that work to the mouse brain and muscle.

In one study, Wagers and colleagues first connected the blood vessels of old and young mice. They measured profound changes to muscle stem cells in the older mice that made the cells appear more youthful. There were also changes to the structure of muscle. Next, they injected the protein that had been shown to rejuvenate hearts into the older mice. Although some individual mice did not change much, on average, the treated mice could run nearly twice as long on a treadmill as older mice not given the protein. The protein had no effect when injected into younger mice.

In a second study, Dr. Lee Rubin, director of translational medicine at the Harvard Stem Cell Institute, found that after parabiosis, the older mice had an increase in the branching network of blood vessels in the brain and in the rate of creation of new brain cells. Treated mice were more sensitive to changes in smell, suggesting the new neurons had an effect on their abilities. The GDF11 protein alone resulted in similar structural changes.

Wagers said that she has begun working with Atlas Venture, a venture capital firm based in Cambridge, to come up with a strategy to turn the insights about GDF11 into potential treatments that could be tested in people.

David Harrison, an aging researcher at Jackson Laboratory, a nonprofit research organization based in Bar Harbor, Maine, who was not involved in the research, said that an important caveat about the research is that it was done on a particular strain of mouse that is inbred. It will be important, he said, to test the protein’s effect in a more genetically diverse population of mice before thinking about extending the work to clinical trials.

Thomas Rando, a professor of neurology at Stanford University School of Medicine who pioneered using the parabiosis technique to study aging, said it is important to try and understand how young blood has its potent effects. But he said it seems very unlikely, given how complex aging is, that reversing it will depend on a single pathway.

“My answer always was and always will be there’s no way there’s a factor,” Rando said. “There are going to be hundreds of factors.”

In the third study published in the journal Nature Medicine, researchers from the University of California, San Francisco and Stanford used parabiosis to search for changes in gene activity in the brain that might help point to how young blood had its effects. They found changes in the activity of genes involved in the connectivity of brain cells in the hippocampus, a memory center.

Instead of using a specific protein, the researchers then gave older mice repeated transfusions of blood from young mice and found that the older animals improved on specific age-related memory tasks, such as locating an underwater platform and remembering an environment where they had experienced an unpleasant foot shock.

Saul Villeda, a UCSF faculty fellow who led the work, said that the results of the three studies reinforce one another, but they differ in their approach.

“I’m really interested to see whether GDF11 accounts for everything, or whether it’s going to be a combination of factors that together that has the full effect,” Villeda said.

All the researchers warned that people hoping to reverse aging shouldn’t get any wild ideas about infusing themselves with young blood, although they acknowledged making their share of vampire jokes.

“I am the oldest member of the team here, and I personally understand the sentiment for patients,” Rubin said. But he still wouldn’t try it.

Written by Carolyn Y. Johnson, who can be reached at cjohnson@globe.com. Follow her on Twitter @carolynyjohnson.

http://www.bostonglobe.com/news/science/2014/05/04/blood-from-young-mice-reverses-aging-brain-muscles/iepDMMf7wrLJy6WgXqpdIJ/story.html?rss_id=Top-GNP&google_editors_picks=true

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community

New study shows how to win Rock-Paper-Scissors

On By A.P.In China, classical game theory, collective cyclic motions, conditioned response, Da Brayn, mixed-strategy Nash equilibrium, Rock Papers Scissors, Zhejiang UniversityLeave a comment

If you are about to engage in an intense – because when are they not intense – game of rock-paper-scissors with a friend or loved one, do not let them read this article.

You, however, will want to take notes.

A team of researchers from China have just released the results of the first large-scale study of the game and their conclusions on player behavior could help you win the next round.

The study, led by three researchers at China’s Zhejiang University, recruited 360 undergraduate and graduate students to play a total of 300 rounds of rock-paper-scissors while their actions were recorded.

When a student won a round, the researchers found, they tended to stick with the same action (i.e. rock, paper or scissor) instead of switching to another.

When a student lost a round, they most often switched to another action, rotating in a clockwise direction, from rock to paper to scissor.

So, if you can think fast enough during each round’s three-second countdown, you can anticipate your opponent’s next move by whether they won, and thus would stay with the same action, or lost, and thus would switch to the next action, which you’d be able to determine by going clockwise.

The findings upend the previously held notion that rock-paper-scissors followed classical game theory, or mixed-strategy Nash equilibrium (NE), “in which every player chooses the three actions with equal probability,” the study’s authors write.

Instead, according to this study, those who win at rock-paper-scissor appear exhibit “collective cyclic motions” and “conditioned response.”

“Our theoretical calculations reveal that this new strategy may offer higher payoffs to individual players in comparison with the NE mixed strategy, suggesting that high social efficiency is achievable through optimized conditional response,” the authors write.

Translation: You can beat the pants off your opponents if you think it through properly.

The researchers say the work they did on just rock-paper-scissors could be extended in future studies to human psychology.

“Whether conditional response is a basic decision-making mechanism of the human brain or just a consequence of more fundamental neural mechanisms is a challenging question for future studies,” they conclude.

http://gma.yahoo.com/blogs/abc-blogs/win-rock-paper-scissors-study-shows-really-175713622–abc-news-lifestyle.html

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

7.5% of American schoolchildren take prescription psychiatric medications

On By A.P.In amphetamine, Anxiety, autism, bipolar disorder, Da Brayn, Depression, Drugs, Medicine, Neuropsychiatric Disease, Obsessive Compulsive Disease, OCD, psychiatrist, Psychiatry, Psychosis, schizophreniaLeave a comment

The National Center for Health Statistics has found that 7.5 percent of American schoolchildren between the ages of six and 17 had been prescribed and taking pills for emotional or behavioral difficulties.

That is one in every 13 kids.

The study also found that more than half (55 percent) of the parents of the participants said that the medications helped their children “a lot,” while another 26 percent said it helped “some.”

The researchers were unable to identify the specific medications prescribed to the children, however they did make some discoveries regarding race and gender of the children on these medications.

Significantly more boys than girls were given medication; about 9.7 percent of boys compared with 5.2 percent of girls.

Older girls were more likely than younger females to be put on medication.

White children were the most likely to be on psychiatric medications (9.2 percent), followed by Black children (7.4 percent) and Hispanic children (4.5 percent).

Children on Medicaid or a Children’s Health Insurance Program (CHIP) were more likely on medication for emotional and behavioral problems (9.9 percent), versus 6.7 percent of kids with private insurance and only 2.7 percent of uninsured children.

Parents of younger children (between ages 6 and 11) were slightly more likely to feel the medications helped “a lot” compared to those of older children.

Parents of males were also more likely to feel the medications helped “a lot” — about 58 percent of parents of males reported that they helped “a lot” compared to 50 percent of the parents of females.

Parents with incomes less than 100 percent of the federal poverty level were the least likely to feel the medications helped “a lot”. Just 43 percent of these parents said the medications helped “a lot”, while about 31 percent said they helped “some”.

More families living below 100 percent of the federal poverty level had children taking medications for emotional and behavioral problems than those above the federal poverty level.

http://atlantablackstar.com/2014/04/25/1-13-schoolkids-takes-psych-meds/

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

Food Wars Could Rage by 2050

On By A.P.In Da Brayn, Food, food shortage, Fred Davies, The Future, U.S. Agency for International DevelopmentLeave a comment

Within a few more decades, dire food shortages may lead to global-scale conflict, warned a top plant scientist in the U.S. Agency for International Development (USAID). There may not be enough land, water and energy to sustain the potential 9 billion people who are projected to share the Earth by 2050.

“Food issues could become as politically destabilizing by 2050 as energy issues are today,” said Fred Davies, senior science adviser for tUSAID’s bureau of food security, in a press release.

Biotechnology, improved breeding and advances in farming techniques may not be capable of keeping up with the growing human population, according to Davies. Even if farm production can be increased through technology, those innovations may not trickle down to small-scale farmers, the very people who most need help to stave off starvation.

Recent history shows that even massive increases in production don’t solve hunger. In the middle of the last century, the “Green Revolution” dramatically increased crop yields. New varieties of wheat and other grains produced bumper crops, but required purchases of expensive seed, fertilizer and other materials.

Hypothetically, food abounded for all after the agricultural advances, and hunger was indeed reduced in many regions. Yet starvation continued because of economic inequalities and lack of access to food supplies. Plus, subsistence farmers couldn’t afford the new technologies or compete with the large farms that could afford fertilizers and high-yielding seeds.

Now, after less than a century, the human population has grown rapidly, fueled by the bountiful harvests of Green Revolution technology. Once again, the global food system approaches its maximum production limit, but this time, technology may not be up to the challenge, as Davies warned.

One way to partially address the challenge could be to shift farm production toward profitable horticultural crops, like chili peppers, as opposed to bulk commodities, such as corn, suggested Davies.

“A greater emphasis is needed in high-value horticultural crops,” Davies said. “Those create jobs and economic opportunities for rural communities and enable more profitable, intense farming.”

In many cultures, sociologists have observed that increasing wealth correlates to decreasing birth rates, a phenomenon known as the demographic-economic paradox. Although a wealthier nation, such as Japan, could support more children, citizens tend to actually have fewer kids.

By lifting people out of poverty, the food wars of the future could be averted, as long as those wealthier future people don’t demand the same amounts of resource-intensive foods, such as beef, that current rich populations enjoy.

http://news.discovery.com/earth/weather-extreme-events/food-wars-could-rage-by-2050-140418.htm

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

Researchers have created a new giant dual-laser that could control the weather

On By A.P.In Da Brayn, laser, Nature Photonics, Science, Technology, University of Arizona, University of Central Florida, Weather, weather controlLeave a comment

Zeus, God of the Sky, may be out of work, as scientists at the University of Central Florida believe they’ve developed a technique — which involves pointing a high powered laser at the sky — to induce clouds to drop rain and hurl thunderbolts.

Scientists have known that water condensation and lightning activity in storm clouds are associated with large amounts of static charged particles. In theory, stimulating those particles with a laser is the key to harnessing Zeus-like powers.

The hard part, scientists say, is creating a laser beam with the right combination of range, precision and strength.

“When a laser beam becomes intense enough, it behaves differently than usual — it collapses inward on itself,” explained Matthew Mills, a graduate student in the UCF Center for Research and Education in Optics and Lasers. “The collapse becomes so intense that electrons in the air’s oxygen and nitrogen are ripped off creating plasma — basically a soup of electrons.”

But students at UCF’s College of Optics & Photonics have collaborated with researchers at the University of Arizona to create a “dressed laser” that they think might be up for the challenge of controlling the weather.

The dressed laser is a high-power laser beam surrounded by a second beam, which acts as a refueling agent, sustaining the strength and accuracy of the central beam over longer distances.

“Since we have control over the length of a filament with our method, one could seed the conditions needed for a rainstorm from afar,” said Mills. “Ultimately, you could artificially control the rain and lightning over a large expanse with such ideas.”

The students recently published their research findings in the journal Nature Photonics. Their efforts were supported by a $7.5 million grant from the Department of Defense.

Read more: http://www.upi.com/Science_News/2014/04/19/Giant-lasers-could-control-the-weather/1691397928851/#ixzz2zRZl9YTP

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

South Korean Researchers Clone Stem Cells From Human Adults

On By A.P.In Cell, cloning, Da Brayn, Science, South KoreaLeave a comment

Scientists from South Korea have devised a technique for cloning adult stem cells that doesn’t involve the destruction of human embryos. The resulting stem cells, which are highly personalized, could be used to treat illnesses such as heart disease and blindness — but the technique could also be used to clone adults.

It’s a process called therapeutic cloning and it involves the production of embryonic cells that are genetically identical to those of the donor, typically for the purpose of using the resulting pluripotent cells to treat disease. The scientists, whose study now appears in Cell, extracted skin cells from two adult males, aged 35 and 75. The DNA was then fused with human eggs donated by four adult women.

A burst of electricity was used to fuse grown cells with eggs whose own DNA had been removed. The eggs then multiplied and soon developed into embryos in the shape of a hollow sphere. This resulted in pluripotent cells — cells that can turn into any kind of human cell.

Last year, scientists essentially did the same thing, though the cells were derived from human fetal and infant DNA (which tend to be more malleable). This technique is considered much more ethically palatable because it does not involve the destruction of human embryos.

As noted, and in addition to creating personalized stem cells to treat such conditions as Parkinson’s disease, heart disease, multiple sclerosis or type-1 diabetes, the technique could be used to clone human adults.

http://io9.com/researchers-clone-stem-cells-from-human-adults-1564755314

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

NASA discovers Kepler-186f, Earth-sized world in orbit that could support life

On By A.P.In Alien life, Ames Research Center, Cygnus, Da Brayn, David Charbonneau, Earth-like planets, Kepler, Kepler-186, Kepler-186f, NASA, Nature, Science, Space and Time2 Comments

For the first time, scientists have found an Earth-sized world orbiting in a life-friendly zone around a distant star.

The discovery, announced on Thursday, is the closest scientists have come so far to finding a true Earth twin. The star, known as Kepler-186 and located about 500 light years away in the constellation Cygnus, is smaller and redder than the sun.

The star’s outermost planet, designated Kepler-186f, receives about one-third the radiation from its parent star as Earth gets from the sun, meaning that high noon on this world would be roughly akin to Earth an hour before sunset, said astronomer Thomas Barclay, with NASA’s Ames Research Center in Moffett Field, California.

The planet is the right distance from its host star for water — if any exists — to be liquid on the surface, a condition that scientists suspect is necessary for life.

“This planet is an Earth cousin, not an Earth twin,” said Barclay, who is among a team of scientists reporting on the discovery in the journal Science this week.

NASA launched its Kepler space telescope in 2009 to search about 150,000 target stars for signs of any planets passing by, or transiting, relative to the telescope’s point of view. Kepler was sidelined by a positioning system failure last year.

Analysis of archived Kepler data continues. From Kepler’s observational perch, a planet about the size and location of Earth orbiting a sun-like star would blot out only about 80 to 100 photons out of every million as it transits.

The pattern is repeated every 365 days and at least three transits would be needed to rule out other possibilities, so the search takes time.

“It’s very challenging to find Earth analogs,” Barclay said. “Most candidates don’t pan out, but things change as we get more measurements.”

Scientists don’t know anything about the atmosphere of Kepler-186f, but it will be a target for future telescopes that can scan for telltale chemicals that may be linked to life.

“This planet is in the habitable zone, but that’s doesn’t mean it is habitable,” Barclay said.

So far, scientists have found nearly 1,800 planets beyond the solar system.

“The past year has seen a lot of progress in the search for Earth-like planets. Kepler-168f is significant because it is the first exoplanet that is the same temperature and is (almost) the same size as Earth,” astronomer David Charbonneau, with the Harvard-Smithsonian Center for Astrophysics, wrote in an email.

“For me the impact is to prove that yes, such planets really do exist,” Charbonneau said. “Now we can point to a star and say, “There lies an Earth-like planet.'”

http://in.mobile.reuters.com/article/idINBREA3G1XI20140417?irpc=932

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.