Scientists Discover "Shadow Person"

From Cosmos Magazine:

by Erica Harrison

SYDNEY: Ever feel as though you're being followed? As if someone is behind you, shadowing your every move? It might be your ‘shadow person', created by unusual activity in a specific brain region, a new study shows.

The paper, published in the British journal Nature, describes the case of a 22-year-old woman with no history of psychiatric problems who was being evaluated for treatment of epilepsy. When a region of her brain called the left temporoparietal junction was electrically stimulated, the woman described encounters with a ‘shadow person' who mimicked her bodily movements.

"Electrical stimulation repeatedly produced a feeling of the presence of another person in her extra-personal space," said Olaf Blanke, co-author of the study conducted by a team of researchers from University Hospital in Geneva, Switzerland.

When the patient was lying down, stimulation of this brain region caused her to feel that someone was behind her. She described the person as young, of indeterminate sex, "a shadow who did not speak or move, and whose position beneath her back was identical to her own", according to the researchers.

When the patient sat up, leaned forward and clasped her knees, she felt that the figure was also sitting, embracing her in its arms - a feeling she described as "unpleasant".

During a language task, in which the seated patient held a card in her right hand, she described the person sitting next to her and trying to interfere with the task. "He wants to take the card … he doesn't want me to read," she said.

Because it was possible to induce the sensation repeatedly, and because the ‘shadow person' closely mimicked the patient's posture and movements, the researchers conclude that the patient was experiencing a perception of her own body.

"The strange sensation that somebody is nearby when no one is actually present has been described by psychiatric and neurological patients, as well as by healthy subjects," said Blanke. Until now, however, it was not understood how the illusion was triggered in the brain.

The temporoparietal junction is known to be involved in creating the concept of ‘self', and the distinction between ‘self' and ‘other'. According to the researchers, stimulation of this region interfered with the patient's ability to integrate information about her own body, leading to her experience of a ‘shadow person'.

Although the woman was aware of the similarity between her own movements and those of her doppelganger, she didn't recognise the experience as an illusion of her own body.

Similar shadowy encounters have been described by people with schizophrenia, as well as by healthy subjects, leading the researchers to believe that: "Our findings may be a step towards understanding the mechanisms behind psychiatric manifestations such as paranoia, persecution and alien control."

Shark disappearance threatens sea life

From the Toronto Star:

Mar 29, 2007 03:24 PM

Canadian Press

HALIFAX – The near extinction of several species of sharks is causing a dangerous ripple effect through the marine food chain, according to a new study that links their virtual disappearance to depletions of other sea life.

The report by a team of researchers at Dalhousie University in Halifax has found that species that were once the primary food source for certain types of large sharks are undergoing a population boom because there aren't as many sharks to prey on them.

The scientists contend that the explosive increase in about a dozen types of smaller sharks, rays and skates has caused a cascading effect throughout the ecosystem as they begin to deplete limited nutrient sources and alter nature's complex food web.

"It's incredibly serious," said Julia Baum, who co-wrote the report to be released Friday in the journal Science. "Everyone knows that the oceans are being overfished and it's the top predators that are being disproportionately hit by overfishing.

"Because they structure everything underneath them in the food web, we may be drastically changing and restructuring how the oceanic food web functions and operates."

The report states that shark populations off the eastern United States are in an even steeper decline that originally thought. Using data from fisheries logs and research surveys from 1970 to 2005, the team discovered that the abundance of several types of so-called great sharks has dropped by more than 99 per cent.

The bull and dusty sharks are verging on extinction, while hammerheads and great white sharks are in dangerously low numbers, Baum said, due largely to overfishing.

The controversial practice of finning – slicing the shark's fin off and then tossing the carcass overboard – has led to precipitous drops in most strains of the large predators globally, the report said.

"What we're seeing is a higher risk of extinction of these species in these areas, and the term we use as ecologists is functional elimination," Baum said, adding that finning kills as many as 73 million sharks a year worldwide for an industry that supplies fins for soups and other uses.

"It means that these great predators can no longer play their roles in the ecosystem as top predators. So they're no longer controlling the species in the food web below them."

The researchers, including the late Ransom Myers who passed away Tuesday, cited a specific example of how the removal of sharks is affecting other species.

Baum, a marine biologist, said they have for the first time linked the decimation of bay scallops in waters off North Carolina to an increase in cownose rays, which eat the delicacy. Sharks feed on the rays, but because there are now so few sharks, the ray population has been allowed to grow to more than 10 times what it was a decade ago.

Cownose rays have wiped out scallop beds to the point that the fishery has been closed every year off North Carolina since 2004.

"This ecological event is having a large impact on local communities that depend so much on healthy fisheries," said Charles Peterson, a professor of marine sciences and biology at the University of North Carolina and co-author of the report.

Baum said it's not clear what the increase in the other species will mean for the food chain and the wider ecosystem, but it's likely skates, rays and smaller sharks are disrupting the wider natural order in oceans around the world.

The loss of the bay scallop has already caused disruptions to seagrass, an important habitat for other marine life, because rays plow through the growth in search of scallops. Rays may also be inhibiting the recovery of oysters, hard clams and soft-shell clams.

Ken Frank, a fisheries scientist with the federal Fisheries Department, said the findings add to what he had discovered in an earlier research paper that looked at how the disappearance of cod affected the food chain.

Frank, whose study was published in Science in 2005, found that the collapse of cod and other large species led to a cascade effect. As the number of large predators declined dramatically, the fish they preyed on – herring, capelin, shrimp and snow crab – experienced a population explosion.

"There are interdependencies among the species, and when you cause these imbalances, you're going to get some effect elsewhere," he said from his office in Halifax.

"For many decades, it was thought this type of cascade effect was possible only in simplified systems like ponds, so seeing this occur in the marine system is alarming. It means we're modifying the way energy is flowing through these systems."

This latest scientific paper follows groundbreaking research Myers and Baum did in 2003 that found shark populations in the Atlantic had plunged dramatically since the mid-1980s.

"We know better now why sharks matter," Baum said. "Keeping top predators is critical for sustaining the health of the ocean."

Radioactive Boy Scout

From Discover:

Teenager achieves nuclear fusion at home
by Stephen Ornes

In 2006 Thiago Olson joined the extremely sparse ranks of amateurs worldwide who have achieved nuclear fusion with a home apparatus. In other words, he built the business end of a hydrogen bomb in his basement. The plasma "star in a jar"—shown at the left—demonstrated his success.

For two years, Olson researched what he would need and scrounged for parts from eBay and the hardware store. Flanges and piping? Check. High-voltage X-ray transformer? Check. Pumps, deuterium source, neutron bubble dosimeter? Check, check, check. “I have cross-country and track, so during those seasons I don’t have much time to work on it,” says Olson, a high school senior in Michigan. “It’s more of a weekend project.” Last November the machine finally delivered the hallmark of success: bubbles in the dosimeter. The bubbles indicate the presence of neutrons, a by-product of fusion—an energy-releasing process in which two hydrogen nuclei crash together and form a helium nucleus. Fusion is commonplace in stars, where hydrogen nuclei fuse in superhot plasma, but temperatures that high are hard to achieve on Earth. Still, the prospect of creating all this energy while forming only nonradioactive helium and easily controlled neutrons has made harnessing fusion one of the most sought-after and heavily funded goals in sustainable energy.

Olson’s apparatus won’t work for generating commercial power because it takes more energy to run than it produces. But he has succeeded in creating a “star in a jar,” a tiny flash of hot plasma. “The temperature of the plasma is around 200 million degrees,” Olson says modestly, “several times hotter than the core of the sun.”

Robert Bussard, a nuclear physicist who has spent most of his career investigating fusion for both the government and private companies, applauds Olson’s ambition. “These kids are studying much more useful physics than what the country is spending billions on,” he says. “It causes them to think. They’re not going down the mainstream path to oblivion.” And, aside from using high voltage and emitting low-level radiation, the machine has been deemed harmless. “About a week ago, the department of health from Michigan called my principal,” Olson says. “They wanted to come over and inspect it. They did that, they were impressed, and it checked out.”

Mystery illness devastates honeybee colonies

From New Scientist:

• 12:31 14 February 2007
• NewScientist.com news service
• Roxanne Khamsi

A mysterious illness is devastating honeybee populations across the US from California to Florida, claiming up to 80% of colonies in some areas. The losses of honeybees could disrupt the pollination of food crops, researchers warn.

Beekeepers are finding once-healthy colonies abandoned just a few days later, says Jerry Bromenshank, at the University of Montana at Missoula and Bee Alert Technology, a company monitoring the problem: “In most cases the only one left is the queen, along with a few young bees.”

The absence of dead bees makes it difficult to know what ails them and where they have gone. Furthermore, experts cannot track the spread of the mysterious illness. “The problem is that it strikes out of the blue,” says Bromenshank.

At a loss for an explanation, researchers have referred to the honeybee decline as “colony collapse disorder”. Reports of the problem have intensified in recent weeks and spanned 22 states, but some beekeepers say that they began seeing their colonies decline almost two years ago.

Almonds and apples

Researchers say colony collapse disorder might be a re-emergence of a similarly mysterious illness that struck US honeybees in the 1960s. Experts never pinpointed the cause behind that previous bee crisis, according to Bromenshank. He notes that in light of this some people have jokingly termed the problem the “disappearing-disappearing illness”.

But beekeepers and farmers see no humour in the potential economic costs of drastic honeybee decline. Almond crops are immediately vulnerable because they rely on honeybee pollination at this time of year. And the insect decline could potentially affect other crops later in the year, such as apples and blueberries.

Bromenshank speculates that dry conditions in the autumn reduced the natural food supply of the honeybees, making them more vulnerable to some sort of virus – such as deformed wing virus – or fungal infection. He notes that the abandoned colonies are not repopulated by other honeybees or insects for at least a few weeks. This, he says, is consistent with the presence of toxic fungal residues from the dying bees that repel other insects from re-inhabiting the colony.

Other scientists have tentatively blamed the problem on pesticides or chemicals specifically designed to control mites in bee colonies.

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This seems related to colony collapse disorder, which has struck before.