Worms turn metal into semiconductors

Worms are useful in the garden and great for fish bait, but one of their talents has remained hidden — until now. Scientists have discovered that worms can manufacture tiny semiconductors.

At King's College in London, researchers fed an ordinary red worm, Lumbricus rubellus, soil laced with metals. The worm produced quantum dots, nano-sized semiconductors that are used in imaging, LED technologies and solar cells. The experiment was published in the Dec. 23 issue of the journal Nature Nanotechnology.

The worms created these electronic components because of their ability to detoxify their body tissue. When worms ingest the metals, proteins in their body shuttle these "toxins" to tissues called chloragogen cells that are similar to a liver in mammals. In the case of cadmium, a molecule called metallothionein attaches to it to take it away. Through several chemical steps the worm separates the metals from the organic molecules they are attached to and stores them in tiny cavities its body, but not forever: eventually whatever toxic metals the worm eats are excreted.

Metamaterials experts show a way to reduce electrons' effective mass to nearly zero

The field of metamaterials involves augmenting materials with specially designed patterns, enabling those materials to manipulate electromagnetic waves and fields in previously impossible ways. Now, researchers from the University of Pennsylvania have come up with a theory for moving this phenomenon onto the quantum scale, laying out blueprints for materials where electrons have nearly zero effective mass.

Such materials could make for faster circuits with novel properties.

The work was conducted by Nader Engheta, the H. Nedwill Ramsey Professor of Electrical and Systems Engineering in Penn's School of Engineering and Applied Science, and Mario G. Silveirinha, who was a visiting scholar at the Engineering School when their collaboration began. He is currently an associate professor at the University of Coimbra, Portugal.

Their paper was published in the journal Physical Review B: Rapid Communications.

Their idea was born out of the similarities and analogies between the mathematics that govern electromagnetic waves -- Maxwell's Equations -- and those that govern the quantum mechanics of electrons -- Schrödinger's Equations.

Risks: Coffee Linked to Fewer Oral Cancer Deaths

A large study has found that drinking coffee is associated with a reduced risk of death from oral cancer.

Researchers studied 968,432 initially healthy men and women beginning in 1982. All completed questionnaires on health and dietary habits, including amounts of tea and coffee consumed, at the start of the study period. Twenty-six years later, 868 people had died of oral or throat cancer.

After adjusting for smoking, alcohol consumption and other factors, the researchers found that the risk of death from oral or throat cancer was 26 percent lower among those who drank one cup a day, 33 percent lower among those who drank two to three cups daily, and 50 percent lower among those who drank four to six cups daily, compared with those who drank no caffeinated coffee.

There was a barely significant association of decaffeinated coffee with reduced risk, and no link at all to tea. The report was posted online this month in The American Journal of Epidemiology.

Should physicians prescribe cognitive enhancers to healthy individuals?

Physicians should not prescribe cognitive enhancers to healthy individuals, states a report being published today in the Canadian Medical Association Journal (CMAJ). Dr. Eric Racine and his research team at the IRCM, the study's authors, provide their recommendation based on the professional integrity of physicians, the drugs' uncertain benefits and harms, and limited health care resources.

Prescription stimulants and other neuropharmaceuticals, generally prescribed to treat attention deficit disorder (ADD), are often used by healthy people to enhance concentration, memory, alertness and mood, a phenomenon described as cognitive enhancement.

"Individuals take prescription stimulants to perform better in school or at work," says Dr. Racine, a Montréal neuroethics specialist and Director of the Neuroethics research unit at the IRCM. "However, because these drugs are available in Canada by prescription only, people must request them from their doctors. Physicians are thus important stakeholders in this debate, given the risks and regulations of prescription drugs and the potential for requests from patients for such cognitive enhancers."

The prevalence of cognitive enhancers used by students on university campuses ranges from 1 per cent to 11 per cent. Taking such stimulants is associated with risks of dependence, cardiovascular problems, and psychosis.

"Current evidence has not shown that the desired benefits of enhanced mental performance are achieved with these substances," explains Cynthia Forlini, first author of the study and doctoral student in Dr. Racine's research unit. "With uncertain benefits and clear harms, it is difficult to support the notion that physicians should prescribe a medication to a healthy individual for enhancement purposes."

The person inside the present: Narcissists buy to big themselves up

But what is the psychology behind gift-giving?

Early results from research led by Dr Aiden Gregg from the University of Southampton, have shown that people with narcissistic tendencies want to purchase products, both for others and for themselves, that positively distinguish them -- that is, that make them stand out from the crowd.

The study -- conducted in collaboration with McGill University's Desautels Faculty of Management and Hanyang University in South Korea -- investigated why narcissistic consumers chose certain products and how those products made them feel. Volunteers from both the universities in South Korea or Canada took part in one of four studies.

Why Are Genius and Madness Connected?

Many of history's most celebrated creative geniuses were mentally ill, from renowned artists Vincent van Gogh and Frida Kahlo to literary giants Virginia Woolf and Edgar Allan Poe. Today, the fabled connection between genius and madness is no longer merely anecdotal. Mounting research shows these two extremes of the human mind really are linked — and scientists are beginning to understand why.

A panel of experts discussed recent and ongoing research on the subject at an event held Thursday (May 31) in New York as part of the 5th annual World Science Festival. All three panelists suffer from mental illnesses themselves.

Kay Redfield Jamison, a clinical psychologist and professor at Johns Hopkins University School of Medicine, said the findings of some 20 or 30 scientific studies endorse the notion of the "tortured genius." Of the many varieties of psychosis, creativity appears to be most strongly linked to mood disorders, and especially bipolar disorder, which Jamison suffers from herself. For example, one study tested the intelligence of 700,000 Swedish 16-year-olds and then followed up a decade later to learn which of them had developed mental illnesses. The startling results were published in 2010. "They found that people who excelled when they were 16 years old were four times as likely to go on to develop bipolar disorder," she said.

Resistance to cocaine addiction may be passed down from father to son

Research from the Perelman School of Medicine at the University of Pennsylvania and Massachusetts General Hospital (MGH) reveals that sons of male rats exposed to cocaine are resistant to the rewarding effects of the drug, suggesting that cocaine-induced changes in physiology are passed down from father to son. The findings are published in the latest edition of Nature Neuroscience.

"We know that genetic factors contribute significantly to the risk of cocaine abuse, but the potential role of epigenetic influences -- how the expression of certain genes related to addiction is controlled -- is still relatively unknown," said senior author R. Christopher Pierce, PhD, associate professor of Neuroscience in Psychiatry at Penn. "This study is the first to show that the chemical effects of cocaine use can be passed down to future generations to cause a resistance to addictive behavior, indicating that paternal exposure to toxins such as cocaine can have profound effects on gene expression and behavior in their offspring."

In the current study, the team used an animal model to study inherited effects of cocaine abuse. Male rats self-administered cocaine for 60 days, while controls were administered saline. The male rats were mated with females that had never been exposed to the drug. To eliminate any influence that the males' behavior would have on the pregnant females, they were separated directly after they mated.

The rats' offspring were monitored to see whether they would begin to self-administer cocaine when it was offered to them. The researchers discovered that male offspring of rats exposed to the drug, but not the female offspring, acquired cocaine self-administration more slowly and had decreased levels of cocaine intake relative to controls. Moreover, control animals were willing to work significantly harder for a single cocaine dose than the offspring of cocaine-addicted rats, suggesting that the rewarding effect of cocaine was decreased.

Two Higgs Bosons? CERN Scientists Revisit Large Hadron Collider Particle Data

A month ago scientists at the Large Hadron Collider released the latest Higgs boson results. And although the data held few obvious surprises, most intriguing were the results that scientists didn’t share.

The original Higgs data from back in July had shown that the Higgs seemed to be decaying into two photons more often than it should—an enticing though faint hint of something new, some sort of physics beyond our understanding. In November, scientists at the Atlas and LHC experiments updated everything except the two-photon data. This week we learned why.

Yesterday researchers at the Atlas experiment finally updated the two-photon results. What they seem to have found is bizarre—so bizarre, in fact, that physicists assume something must be wrong with it. Instead of one clean peak in the data, they have found two. There seems to be a Higgs boson with a mass of 123.5 GeV (gigaelectron volts, the measuring unit that particle physicists most often use for mass), and another Higgs boson at 126.6 GeV—a statistically significant difference of nearly 3 GeV. Apparently, the Atlas scientists have spent the past month trying to figure out if they could be making a mistake in the data analysis, to little avail. Might there be two Higgs bosons?

We are basically honest – except when we are at work, study suggests

A new study has revealed we are more honest than you might think. The research by the University of Oxford and the University of Bonn suggests that it pains us to tell lies, particularly when we are in our own homes. It appears that being honest is hugely important to our sense of who we are. However, while it might bother us to tell lies at home, we are less circumspect at work where we are probably more likely to bend the truth, suggests the study.

The researchers conducted simple honesty tests by ringing people in their own homes in Germany and asking them to flip a coin. The study participants were asked over the phone to report on how it landed. The catch to this test was that each of the individuals taking part was given a strong financial incentive to lie without the fear of being found out. The study participants were told that if the coin landed tails up, they would receive 15 euros or a gift voucher; while if the coin landed heads up, they would receive nothing.

Using randomly generated home phone numbers, 658 people were contacted who agreed to take part. Although the researchers could not directly observe the behaviour of the individuals in their own homes, the aggregated reports show a remarkably high level of honesty. Over half of the study participants (55.6 per cent) reported that the coin landed heads-up, which meant they would receive nothing. Only 44.4 per cent reported tails up, collecting their financial reward as a result.

Extending Einstein's ideas: New kind of quantum entanglement demonstrated

Physicists at the University of Calgary and at the Institute for Quantum Computing in Waterloo have published new research in Nature Physics which builds on the original ideas of Einstein and adds a new ingredient: a third entangled particle.

Quantum entanglement is one of the central principles of quantum physics, which is the science of sub-atomic particles. Multiple particles, such as photons, are connected with each other even when they are very far apart and what happens to one particle can have an effect on the other one at the same moment, even though these effects can not be used to send information faster than light.

The new form of three-particle entanglement demonstrated in this experiment, which is based on the position and momentum properties of photons, may prove to be a valuable part of future communications networks that operate on the rules of quantum mechanics, and could lead to new fundamental tests of quantum theory that deepen our understanding of the world around us.
"This work opens up a rich area of exploration that combines fundamental questions in quantum mechanics and quantum technologies," says Christoph Simon, paper co-author and researcher at the University of Calgary.

This research extends the theories of Einstein, seventy-seven years later. In 1935, Albert Einstein, Boris Podolsky, and Nathan Rosen, commonly referred to as EPR, published a thought experiment designed to show that quantum mechanics, by itself, is not sufficient to describe reality.

The limits of the productive capacity of ecosystems

In a letter to Science published today, Karl-Heinz Erb from the Institute of Social Ecology Vienna and a number of co-authors discuss how the measurement of biomass production and consumption can be used to gain a better understanding of the limits of the productive capacity of ecosystems.

Future growth of population and GDP are challenged byglobal biophysical limits, such as the scarcity of resources (land, energy, raw materials) as well as the limited capacity of the biosphere to cope with end products (e.g. greenhouse gas emissions). One promising indicator, which is frequently mentioned in this context, and is the subject of research at the Alpen-Adria-Universität, is the human utilization, or "appropriation" of net primary production (HANPP); that is, of the biomass production of green plants. Biomass represents the basis for all human and animal food chains. Furthermore, biomass is not only a source of energy, but also plays a significant role for the carbon sequestration of ecosystems.

In a current letter to the editor of Science, Karl-Heinz Erb from the Institute of Social Ecology at the Alpen-Adria-Universität joins two AAU colleagues and an international group of colleagues in a discussion of how the measurement of biomass production and consumption can be used to gain a better understanding of the "productive capacity of ecosystems." "We identify the factors -- for example, land use intensity -- which are important for a clearer grasp of the global limits of the productive capacity of ecosystems," Karl-Heinz Erb explains.

Phew! Universe's Constant Has Stayed Constant | Proton-Electron Mass Ratio

The constant — the ratio of the mass of a proton to the mass of an electron — has changed by only one hundred thousandth of a percent or less over the past 7 billion years, the observations show.

The scientists determined this by pointing the Effelsberg 100-m radio telescope at a distant galaxy that lies 7 billion light-years away, meaning its light has taken that long to reach Earth. Thus, astronomers are seeing the galaxy as it existed 7 billion years ago. The telescope looked for special light features that reflect the absorption of methanol, a simple form of alcohol that contains carbon, hydrogen and oxygen.

If the ratio of the mass of the protons and electrons inside those atoms were different than it is here and now in our own galaxy, the scientists would be able to detect this in the properties of the light.

"This idea makes the methanol molecule an ideal probe to detect a possible temporal variation in the proton-electron mass ratio," astrophysicist Wim Ubachs of VU University Amsterdam said in a statement. "We proposed to search for methanol molecules in the far-distant universe, to compare the structure of those molecules with that observed in the present epoch in laboratory experiments."

Their observations confirmed that the proton-electron mass ratio has changed by no more than 10^-7 over the past 7 billion years. The universe itself is 13.7 billion years old. [The Universe: Big Bang to Now in 10 Easy Steps ]

Schizophrenia linked to social inequality

Higher rates of schizophrenia in urban areas can be attributed to increased deprivation, increased population density and an increase in inequality within a neighbourhood, new research reveals. The research, led by the University of Cambridge in collaboration with Queen Mary University of London, was published today in the journal Schizophrenia Bulletin.

Dr James Kirkbride, lead author of the study from the University of Cambridge, said: "Although we already know that schizophrenia tends to be elevated in more urban communities, it was unclear why. Our research suggests that more densely populated, more deprived and less equal communities experience higher rates of schizophrenia and other similar disorders. This is important because other research has shown that many health and social outcomes also tend to be optimal when societies are more equal."

The scientists used data from a large population-based incidence study (the East London first-episode psychosis study directed by Professor Jeremy Coid at the East London NHS Foundation Trust and Queen Mary, University of London) conducted in three neighbouring inner city, ethnically diverse boroughs in East London: City & Hackney, Newham, and Tower Hamlets.

427 people aged 18-64 years old were included in the study, all of whom experienced a first episode of psychotic disorder in East London between 1996 and 2000. The researchers assessed their social environment through measures of the neighbourhood in which they lived at the time they first presented to mental health services because of a psychotic disorder. Using the 2001 census, they estimated the population aged 18-64 years old in each neighbourhood, and then compared the incidence rate between neighbourhoods.

Too many antibiotics? Bacterial ecology that lives on humans has changed in last 100 years

A University of Oklahoma-led study has demonstrated that ancient DNA can be used to understand ancient human microbiomes. The microbiomes from ancient people have broad reaching implications for understanding recent changes to human health, such as what good bacteria might have been lost as a result of our current abundant use of antibiotics and aseptic practices.

Cecil M. Lewis Jr., professor of anthropology in the OU College of Arts and Sciences and director of the OU Molecular Anthropology Laboratory, and Raul Tito, OU Research Associate, led the research study that analyzed microbiome data from ancient human fecal samples collected from three different archaeological sites in the Americas, each dating to over 1000 years ago. In addition, the team provided a new analysis of published data from two samples that reflect rare and extraordinary preservation: Otzi the Iceman and a soldier frozen for 93 years on a glacier.

"The results support the hypothesis that ancient human gut microbiomes are more similar to those of non-human primates and rural non-western communities than to those of people living a modern lifestyle in the United States," says Lewis. "From these data, the team concluded that the last 100 years has been a time of major change to the human gut microbiome in cosmopolitan areas."

Gay sex makes fish more attractive to females

A little fish that appears to enjoy homosexual relations with other males simultaneously increases their attractiveness to females, German researchers have discovered.

A new study by scientists from the University of Frankfurt found the Shortfin molly – a popular fish for tropical aquariums – places a premium on sexual activity. Therefore a male engaging in homosexual behaviour can impress a female with his virility and fitness.

“Sexual activity in itself is a sign of quality for females because sick or underfed males show little sexual behaviour,” said evolutionary biologist David Bierbach, adding this could possibly explain bisexuality in some other species as well.

Female sharks capable of virgin birth

Female sharks can fertilize their own eggs and give birth without sperm from males, according to a new study of the asexual reproduction of a hammerhead in a U.S. zoo.

The joint Northern Ireland-U.S. research, being published Wednesday in the Royal Society's peer-reviewed Biology Letter journal, analyzed the DNA of a shark born in 2001 in the Henry Doorly Zoo in Omaha, Neb. The shark was born in a tank with three potential mothers, none of whom had contact with a male hammerhead for at least three years.

Analysis of the baby shark's DNA found no trace of any chromosomal contribution from a male partner. Shark experts said this was the first confirmed case in a shark of parthenogenesis, which is derived from Greek and means "virgin birth."

3-D printer helps create a 'biobot'

These bots were made for walking — out of rat heart cells and hydrogel.

Scientists have paired these unlikely ingredients to create simple biological machines that look something like a front-loaded inchworm and can step their way through fluid at speeds up to 236 micrometers per second.

Bioengineers working at the boundary between organics and mechanics dream of harnessing the power of biology's nuts and bolts. Some have built tweezers out of DNA; others have made sensors by sticking bacteria on a chip. It's no easy task — plastic and metal are far more predictable materials to work with.

But in work published recently in Scientific Reports, a team of bioengineers described how they came up with a way to manufacture biobots quickly and efficiently with a three-dimensional printer.

The printer builds preprogrammed shapes layer by ultrathin layer, until it has constructed a soft "body" out of hydrogel, a class of polymers that includes the stuff contact lenses are made from, said senior author Rashid Bashir, a bioengineer at the University of Illinois at Urbana-Champaign.

Engineered immune cells produce complete response in child with an aggressive leukemia

By reprogramming a 7-year-old girl's own immune cells to attack an aggressive form of childhood leukemia, a pediatric oncologist has achieved a complete response in his patient, who faced grim prospects when she relapsed after conventional treatment. The innovative experimental therapy used bioengineered T cells, custom-designed to multiply rapidly in the patient, and then destroy leukemia cells. After the treatment, the child's doctors found that she had no evidence of cancer.

Google Search Algorithm Models Cancer Spread

The equations Google employs to predict the Web pages users visit has inspired a new way to track the spread of cancer cells throughout the body.

“Each of the sites where a spreading, or “metastatic,” tumor could show up are analogous to Web pages,” said Paul Newton, a mathematician at the University of Southern California, who has been working with cancer specialists at the Scripps Research Institute.

Google ranks Web pages by the likelihood that an individual would end up visiting each one randomly. These predictions are based on the trends of millions of users across the Web. Google uses something called the "steady state distribution" to calculate the probability of someone visiting a page.

“You have millions of people wandering the Web, [and] Google would like to know what proportion are visiting any given Web page at a given time,” Newton explained.

“It occurred to me that steady state distribution is equivalent to the metastatic tumor distribution that shows up in the autopsy datasets.”

Violent video games: More playing time equals more aggression

A new study provides the first experimental evidence that the negative effects of playing violent video games can accumulate over time.