Eating dirt can be good for the belly, researchers find

Most of us never considered eating the mud pies we made as kids, but for many people all over the world, dining on dirt is nothing out of the ordinary. Now an extensive meta-analysis forthcoming in the June issue of The Quarterly Review of Biology helps explain why.

According to the research, the most probable explanation for human geophagy—the eating of earth—is that it protects the stomach against toxins, parasites, and pathogens.

The first written account of human geophagy comes from Hippocrates more than 2,000 years ago, says Sera Young, a researcher at Cornell University and the study’s lead author. Since then, the eating of earth has been reported on every inhabited continent and in almost every country.

Despite its ubiquity, scientists up to now have been unable to definitively explain why people crave earth. Several hypotheses had been considered plausible. Some researchers think geophagy is simply a consequence of food shortage. In other words, people eat dirt to ease the pangs of hunger, even though it doesn’t provide any nutritional value. Others have suggested that nutrition is exactly why dirt is consumed; perhaps people crave dirt because it provides nutrients they lack, such as iron, zinc, or calcium. Still others posit that earth has a protective effect, working as a shield against ingested parasites, pathogens, and plant toxins.

To sort through the possible explanations, Young and her colleagues analyzed reports from missionaries, plantation doctors, explorers, and anthropologists to put together a database of more than 480 cultural accounts of geophagy. The database includes as many details as possible about the circumstances under which earth was consumed, and by whom. The researchers could then use patterns in the data to evaluate each potential explanation.

They found the hunger hypothesis unlikely. Studies in the database indicate that geophagy is common even when food is plentiful. Moreover, when people eat dirt they tend to eat only small quantities that are unlikely to fill an empty stomach.

The nutrition hypothesis was also a poor fit to the data. The database shows that the kind of earth people eat most often is a type of clay that contains low amounts of nutrients like iron, zinc, and calcium. Plus, if calcium deficiency drove people to eat dirt, one would expect them to do it most often at life stages when they need calcium the most—adolescence or old age. But that isn’t the case, according to the database. Reports do indicate that geophagy is often associated with anemia, but several studies have shown that cravings for earth continue even after people are given iron supplements. What’s more, some research suggests that clay can bind to nutrients in the stomach, making them hard to digest. If that’s true, it’s not a lack of nutrients that causes geophagy; rather it could be the other way around.

Overall, the protection hypothesis fits the data best, the Cornell researchers found. The database shows that geophagy is documented most commonly in women in the early stages of pregnancy and in pre-adolescent children. Both categories of people are especially sensitive to parasites and pathogens, according to Young and her colleagues. In addition, geophagy is most common in tropical climates where foodborne microbes are abundant. Finally, the database shows that people often eat earth during episodes of gastrointestinal stress. It’s unlikely the intestinal problems are caused by the dirt itself because the type of clay people usually eat comes from deep in the ground, where pathogens and parasites are unlikely to contaminate it. Plus, people usually boil the clay before eating it.

More study would be helpful to confirm the protection hypothesis, the researchers say, but the available data at this point clearly support it over the other explanations.

“We hope this paper stimulates [more] research,” Young and her colleagues write. “More importantly, we hope readers agree that it is time to stop regarding geophagy as a bizarre, non-adaptive gustatory mistake.”

“With these data, it is clear that geophagy is a widespread behavior in humans … that occurs during both vulnerable life stages and when facing ecological conditions that require protection.”

via Eating dirt can be good for the belly, researchers find.

Only one person is known to have been completely cured of AIDS

 Caring for HIV patients in developing countries alone already costs around $13 billion (7.9 billion pounds) a year and that could treble over the next 20 years.

In tough economic times, the need to find a cure has become even more urgent, says Francoise Barre Sinoussi, who won a Nobel prize for her work in identifying Human Immunodeficiency Virus (HIV). “We have to think about the long term, including a strategy to find a cure,” she says. “We have to keep on searching until we find one.”

The Berlin patient is proof they could. His case has injected new energy into a field where people for years believed talk of a cure was irresponsible.

Timothy Ray Brown was living in Berlin when besides being HIV-positive, he had a relapse of leukaemia. He was dying. In 2007, his doctor, Gero Huetter, made a radical suggestion: a bone marrow transplant using cells from a donor with a rare genetic mutation, known as CCR5 delta 32. Scientists had known for a few years that people with this gene mutation had proved resistant to HIV.

 

“We really didn’t know when we started this project what would happen,” Huetter, an oncologist and haematologist who now works at the University of Heidelberg in southern Germany, told Reuters. The treatment could well have finished Brown off. Instead he remains the only human ever to be cured of AIDS. “He has no replicating virus and he isn’t taking any medication. And he will now probably never have any problems with HIV,” says Huetter. Brown has since moved to San Francisco. …

via Special Report – An end to AIDS? | World | Reuters.

Could Conjoined Twins Share a Mind?

…Suddenly the girls sat up again, with renewed energy, and Krista reached for a cup with a straw in the corner of the crib. “I am drinking really, really, really, really fast,” she announced and started to power-slurp her juice, her face screwed up with the effort. Tatiana was, as always, sitting beside her but not looking at her, and suddenly her eyes went wide. She put her hand right below her sternum, and then she uttered one small word that suggested a world of possibility: “Whoa!”

In any other set of twins, the natural conclusion about the two events — Krista’s drinking, Tatiana’s reaction — would be that they were coincidental: a gulp, a twinge, random simultaneous happenstance. But Krista and Tatiana are not like most other sets of twins. They are connected at their heads, where their skulls merge under a mass of shaggy brown bangs. The girls run and play and go down their backyard slide, but whatever they do, they do together, their heads forever inclined toward each other’s, their neck muscles strong and sinuous from a never-ending workout.

Twins joined at the head — the medical term is craniopagus — are one in 2.5 million, of which only a fraction survive. The way the girls’ brains formed beneath the surface of their fused skulls, however, makes them beyond rare: their neural anatomy is unique, at least in the annals of recorded scientific literature. Their brain images reveal what looks like an attenuated line stretching between the two organs, a piece of anatomy their neurosurgeon, Douglas Cochrane of British Columbia Children’s Hospital, has called a thalamic bridge, because he believes it links the thalamus of one girl to the thalamus of her sister. The thalamus is a kind of switchboard, a two-lobed organ that filters most sensory input and has long been thought to be essential in the neural loops that create consciousness. Because the thalamus functions as a relay station, the girls’ doctors believe it is entirely possible that the sensory input that one girl receives could somehow cross that bridge into the brain of the other. One girl drinks, another girl feels it. …

via Could Conjoined Twins Share a Mind? – NYTimes.com.

NASA’s Endeavour: Space shuttle makes its final landing

The last and next-to-last ships in America’s 30-year space shuttle program passed in the dark early Wednesday morning as Endeavour returned to Earth completing the penultimate mission and Atlantis crawled slowly toward its final turn on the launchpad.

Endeavour touched down gently at 2:35 a.m. at Kennedy Space Center after awakening a few in central Florida with its farewell double sonic boom. Capt. Mark E. Kelly, commander of the shuttle, thanked the thousands of workers who kept what he called “this amazing vehicle” flying, and took note of the end.”It’s sad to see her land for the last time, but she really has a great legacy,” Kelly said.

Atlantis, scheduled to launch July 8 on the 135th and last mission of the space shuttle program, took its final rollout a little late because of a hydraulic leak in the gigantic vehicle that transports it from the assembly building.

After Atlantis, officials acknowledge, there will be a lull before NASA can create a new space program that might provide an economic engine for the Space Coast. Already, thousands of shuttle workers have been laid off, and thousands more will be let go after the Atlantis mission is completed.

“It will be different without the shuttle program; that certainly is a reality,” said Launch Director Michael Leinbach. “I feel good that Kennedy Space Center will be used in the future. I don’t have a day. I can’t tell you when the next program will come here.” …

via NASA’s Endeavour: Space shuttle makes its final landing – latimes.com.

‘Devil Worm’ Takes Animal Life to New Depths

It came from the deep, a mile below the Earth’s surface, in a place where only bacteria were thought to exist.

It’s Halicephalobus mephisto, a new species of roundworm that radically extends the possibilities of animal life on this planet and perhaps on others.

“Our results expand the known metazoan biosphere and demonstrate that deep ecosystems are more complex than previously accepted,” wrote researchers led by biologist Gaetan Borgonie of Belgium’s Ghent University in a June 1 Nature paper. “The ability of multicellular organisms to survive in the subsurface should be considered in the evolution of eukaryotes and the search for life on Mars.”

It’s only been two decades since scientists recognized that any life whatsoever could live hundreds or thousands of feet beneath Earth’s surface, a region of extreme pressure, high temperatures and few nutrients. Now it’s thought that up to one-half of all biological matter exists there, though this newly conventional wisdom holds that subsurface life is strictly the domain of single-celled organisms, not complex animals.

For the last 20 years, Borgonie has studied roundworms, developing what he calls “a healthy respect for their ability to withstand stress.” Various members of the ubiquitous, 28,000-species-strong phylum can live almost without oxygen, in extremely acidic environments, and despite prolonged starvation. When space shuttle Columbia tragically disintegrated upon re-entering Earth’s atmosphere in 2003, roundworms in a canister on its wings survived.

Five years ago, Borgonie started to wonder whether roundworms might live in Earth’s subsurface. Comparing their known physiological limits to subsurface conditions, he reasoned that roundworms should be able to survive there. Few people agreed.

“Everyone thought I was insane risking a career hunting something everybody said they knew could not be,” said Borgonie. But even as grantmakers denied him funding, he met Tullis Onstott, a Princeton University biologist who also suspected that roundworms could live deep.

via ‘Devil Worm’ Takes Animal Life to New Depths | Wired Science | Wired.com.

Octomom’s Doctor Has License Revoked For ‘Mega-Birth’

The state medical board has revoked the license of the fertility doctor who helped “Octomom” Nadya Suleman become the mother of 14 children through repeated in vitro treatments, according to a decision made public Wednesday.

The Medical Board of California said it was necessary to revoke Dr. Michael Kamrava’s license to protect the public. The revocation takes effect July 1.

The Beverly Hills fertility doctor has acknowledged implanting 12 embryos into Suleman, then 33, prior to the pregnancy that produced her octuplets. It was six times the norm for a

woman her age.

That was a mistake, according to the board, which rejected an earlier recommendation to give Kamrava five years of probation to dole out the harsher punishment.

“While the evidence did not establish (Kamrava) as a maverick or deviant physician, oblivious to standards of care in IVF practice, it certainly demonstrated that he did not exercise sound judgment in the transfer of twelve embryos to (Suleman),” the board said in its 45-page decision.

Kamrava’s lawyer Henry Fenton did not immediately return phone calls seeking comment.

Since Suleman’s octuplets were born in January 2009, the medical community and public have puzzled over how a doctor could have implanted so many embryos into a patient and how the babies were carried to premature birth.

In practice, fertility doctors avoid mega-births, as high number multiple births are sometimes called, because the process can put the mother at risk for serious complications and death. Crowding in a mother’s uterus could also result in premature birth, cerebral palsy, developmental delays or other health problems for the babies.

via Octomom’s Doctor Has License Revoked For ‘Mega-Birth’.

Monkeys Playing Rock, Paper, Scissors Teaches Us About Regret

We humans tend to think of ourselves as the only sentient beings capable of regret, a key emotion that helps keep us from making the same mistakes over and over. Now a new study shows that rhesus monkeys may be saddled with the same feelings of disappointment — at least when they lose at rock, paper, scissors.

A duo of researchers from Yale School of Medicine taught the animals to play a modified version of the popular childhood game. When the monkey won, it got a large container of juice as a reward. If the monkey and the researcher tied, the monkey was given a smaller reward. Monkeys that lost were given nothing. These monkeys displayed regret about their missteps, said Daeyeol Lee, a professor of neurobiology at Yale School of Medicine and the Kavli Institute for Neuroscience, and Hiroshi Abe of Yale medical school’s department of neurobiology.

How do they know? Because each time a monkey lost, it was more likely in the next round to use the gesture that would have won in the previous one (so, for instance, if the researcher’s rock beat the monkey’s scissors, the monkey was more likely to throw a rock in the next round). That suggests the monkeys were capable of analyzing past results and imagining a different outcome, the researchers said.

In a second experiment, Lee and Abe recorded the monkeys’ neuronal function as they played the game, hoping to get a better understanding of how regret registers in the brain. When the monkeys lost, they showed activity in two regions of the brain associated with the rational and emotional components of regret: the dorsolateral prefrontal cortex, which is involved in working memory, and the orbitofrontal cortex, which is associated with the emotional aspect of regret.

Lee and Abe hope their findings can be used to help treat patients who suffer from pathological regret, such as mental illnesses that lead patients to obsess over past decisions that led to poor outcomes. “Regret serves us well most of the time, by helping us recognize choices that lead to bad outcomes,” said Lee in a statement. “But sometimes regret can be very damaging.”

via How Monkeys Playing Rock, Paper, Scissors Teaches Us About Where Regret Comes From – - TIME Healthland.

 

Massachusetts emergency after tornadoes kill four

A cluster of tornadoes has hit the US state of Massachusetts, killing at least four people.

They roared through some 20 towns, ripping off roofs, uprooting trees and scattering debris.

Worst hit was Springfield, the third largest city in the state, where 33 injuries were reported. A state of emergency has been declared and the National Guard has been called in.

Tornadoes are rare, but not unheard of, in the north-eastern US.

State Governor Deval Patrick said the path of damage from the first and most powerful tornado rampaged from Westfield, just west of Springfield, and extended east to the community of Douglas.

A second, slightly less powerful twister, cut a path from West Springfield to Sturbridge in the central part of the state.

The damaged area is about 90 miles (145km) west of Boston.

The storm struck after a tornado alert was issued for much of the East Coast, including Philadelphia, New York and Boston.

At least 48,000 homes have been left without electricity, said the Massachusetts governor.

The casualty figures are likely to rise, he warned at a news conference: “It is early going yet, so those are not final numbers. Although we are hoping and praying and working as hard as possible to keep the fatalities limited to those four.” …

via BBC News – Massachusetts emergency after tornadoes kill four.

DNA computer ‘calculates square roots’

Researchers have shown off a “DNA computer” of unprecedented complexity, which can calculate square roots.

DNA computing uses chemical reactions to solve problems in which a number of DNA strands act as “bits”.

The work, reported in Science, required 130 strands of DNA to work in a cascade of programmed chemical changes.

The approach is not designed to rival traditional electronics, but rather to allow computing to occur in biological contexts, perhaps even in the body.

DNA computing was first proposed by Leonard Adelman in 1994, to solve what is known as the “travelling salesman problem” – determining the shortest path that joins a number of geographically separated locations.

Since then, a wide array of approaches has aimed to make use of the properties that make DNA attractive for computing: it can be made to order and its interactions with itself are well-studied and reliable.

In 2006, Erik Winfree of the California Institute of Technology (Caltech) and his colleagues published an article in Science a framework making use of one of these approaches, known as strand displacement.

Stretches of DNA made of just one strand (rather than the two joined strands that form the well-known double helix) were used as anchor points for other single strands.

By carefully “programming” the movement of these strands, the researchers were able to recreate a number of elements familiar from conventional computing, including logic gates, amplification, and feedback.

“Those circuits were smaller [than those of the current work], but more importantly, they were built using more complex DNA molecules that made systems more difficult to debug and had other problems,” Professor Winfree told BBC News. …

via BBC News – DNA computer ‘calculates square roots’.

Not sure I see the point when we already have computers…

German Death Cucumber Bacteria Outbreak is new form of E. coli

The E. coli outbreak in Germany is a new form of the bacterium, researchers and public health experts believe.

The infection can cause the deadly complication – haemolytic-uraemic syndrome (HUS) – affecting the blood and kidneys.

More than 1,500 people have been infected and 18 have died: 17 in Germany and one in Sweden.

In the UK, three British nationals have been infected – all had visited Germany.

The World Health Organisation said the variant had “never been seen in an outbreak situation before.”

Scientists at the Beijing Genomics Institute in China are also reported as saying the new form was “highly infectious and toxic.”

The Health Protection Agency said it was likely to be a new variant of the rare strain O104 – possibly with a newly acquired ability to infect large numbers of people.

In a statement it said: “While there is a lot more that we need to learn about this bacterium, the evidence that is already available tells us that the German authorities have been dealing with something new.”

Professor Gad Frankel, from Imperial College London, the Sanger Institute and the Medical Research Council, said: “This is a new combination and a deadly combination.

“It has a gene which produces a toxin and another which helps the bacterium colonise the gut more efficiently, which effectively means even more toxin is produced. …

The HPA continues to advise that people travelling to Germany should not eat raw cucumber, lettuce or tomatoes and that they should seek medical advice if they have bloody diarrhoea.

It said one of the strange things about the outbreak was the number of cases of haemolytic uraemic syndrome. It is a very severe kidney complication which destroys red blood cells and can also affect the central nervous system.

Dr Dilys Morgan, from the Health Protection Agency, said: “It’s very unusual for adults to have HUS anyway….

• Germany: 470 cases, 17 deaths
• Sweden: 15 cases, one death
• Denmark: Seven cases
• The Netherlands: Three cases
• UK: Three cases
• Spain: One case

via BBC News – Outbreak is new form of E. coli.