According to the study, people expend more effort on actions when the message to move is accompanied by a little subliminal "pep talk." The researchers tested this idea by showing a group of exertion-related words such as "vigorous" to people and later measuring their performance on a handgrip test. People who saw encouraging words such as "good" mixed in with the exertion words had stronger and quicker grips that those who just saw exertion words, suggesting that the positive words motivated people to expend extra effort on the task.

An analysis of the earliest fossil evidence of human lineage – a femur from the six million year old Orrorin tugenensis -- indicates that this species was bipedal. The functional and phylogenetic significance of these remains have been hotly debated since their discovery in 2000. To date, no one has measured and analyzed the shape of these bones and compared them to modern humans, living apes and other fossil hominins. Recently, though, researchers were granted permission to measure the original fossils in Kenya. Their results reveal and confirm bipedal adaptations. The bones closely resemble those from Australopithecus and Paranthropus, circa 3 to 2 million years ago, contradicting the hypothesis that Orrorin is more closely related to Homo than to Australopithecus.

Scientists say the findings show how the water cycle is working on Mars, and that the cycle is probably quite active today.

Instead, economists Isabelle Brocas and Juan D. Carrillo present a situation - commonly observed in real life - in which all parties have access to the same information, but one party still manages to control public opinion.

For example, a pharmaceutical company such as Merck may be obliged to make public the findings of all studies related to a new drug. Preliminary trials may indicate no short-term side effects, and the company may elect not to perform follow-up trials before releasing the drug on the market.

"Optimally, you want to provide enough information so the other party reaches a certain level of confidence, but stop once you reach that level," Brocas explained. "Otherwise, it may be the case that more information causes the confidence level to go down."

The study, "Influence Through Ignorance," is the first to thoroughly examine situations in which power comes from controlling the flow of public information, as opposed to the possession of private information.

As Brocas and Carrillo explain, there are secrets - facts that are deliberately withheld - and there are facts that are not known to anybody.

"It's not necessary to have extra information," Brocas said. "You can induce people to do what you want just by stopping the flow of information or continuing it. That's enough."

Notably, the party manipulating the flow of information must deliberately choose to remain uninformed as well - which can backfire.

In Merck's case, a study released five years after the drug was introduced on the market showed that taking Vioxx significantly increased the risk of heart attacks. Merck funded the study, which had been intended to see if the painkiller was also effective against colon polyps.

Now, embroiled in a $4.85 billion settlement, the company claims that Vioxx poses no statistically significant long-term risk to the heart once it is no longer taken. This claim is disputed: Merck stopped monitoring patients after only a year, discontinuing the study once the drug was taken off the market.

Similarly, the researchers explain, the head of a council may terminate discussion and introduction of new evidence about, say, whether to continue searching for weapons of mass destruction. Calling for a vote when sentiment seems biased in a certain direction effectively curtails how much all members, including the chairperson, know about the issue at stake.

"Overall, the ability of to control the flow of news and remain publicly ignorant gives the leader some power, which is used to influence the actions of the follower," the researchers wrote. "Our result suggests that the chairperson, the President and media can bias the decision of the committee, electorate and public by strategically restricting the flow of information."

Brocas and Carrillo are in the midst of a follow-up to the study that gauges how well individuals intuitively understand the "influence through ignorance" phenomenon: "We're interested in whether people understand their ability to manipulate information and if they do it optimally," Brocas said.

The paper also provide implications for several important variants, such as how public opinion is affected when there is more than one source of information available to everyone and it is not excessively costly to obtain.

Competition, supported by media diversity and public sources of research funding, not only induces outlets to release more information but also causes the "influence through ignorance" effect to diminish - and under certain circumstances to vanish - the researchers found.

Prior research has documented the association between children's cognitive achievement and the socioeconomic status of their parents as measured by education level, occupation, and income. Many of these studies focused on the effect of poverty-defined by family income-on children's achievement, but household wealth (i.e., net worth) has received little attention.

This new study used new methods, including data from a new national study (the Panel Study of Income Dynamics and its Child Development Supplement). It explored many functional forms and sources of wealth, looking at different mediating pathways of wealth from distinct sources, and analyzing how wealth affects children's cognitive achievement at different stages of childhood.

The researchers found a marked disparity in family wealth between Black and White families with young children, with White families owning more than 10 times as many assets as Black families. The study found that family wealth had a stronger association with cognitive achievement of school-aged children than that of preschoolers, and a stronger association with school-aged children's math than with their reading scores. Family wealth accumulated from different sources also was found to have a distinct influence on children at different developmental stages. Liquid assets, particularly holdings in stocks or mutual funds, were positively associated with school-aged children's test scores. Family wealth was associated with a higher quality home environment, better parenting behavior, and children's private school attendance.

The researchers suggest that the stronger impact of wealth on school-aged children may be because school-aged children benefit more from family wealth that is spent on educational resources that require substantial financial investment, such as private schools, extracurricular activities, and cultural experiences. Furthermore, older children may be more conscious of differences in wealth relative to their peers as they are exhibited in the quality of the learning environment, possessions, and the type of neighborhood where children live. These differences may influence their self-esteem and aspirations, which in turn are positively associated with their school performance.

"While wealth may help smooth consumption on a more short-term basis, the presence of wealth over time in a family (or extended family) may have a stronger impact of engendering a sense of economic security, future orientation, and the ability to take risks among all family members which, in turn, positively affect child development," according to W. Jean Yeung, professor of sociology at New York University and the lead author of the study.

Despite the marked disparity in wealth between Black and White families, the study found little evidence that wealth by itself explains the test score gaps between Black and White children. Those gaps were found to become less meaningful when child and family demographic characteristics and parents' income, education, and occupation were held constant. "Although wealth may not have a substantial short-term benefit in narrowing the Black-White achievement gap among young children, allowing and encouraging low-income families to accumulate wealth may improve family dynamics and foster a forward-looking attitude that may benefit children's development in the long run," said Yeung. "The financial effects of wealth would likely be observed later in life when school financing becomes an issue."

Low doses of the toxic gas responsible for the unpleasant odor of rotten eggs can safely and reversibly depress both metabolism and aspects of cardiovascular function in mice, producing a suspended-animation-like state. In the April 2008 issue of the journal Anesthesiology, Massachusetts General Hospital (MGH) reseachers report that effects seen in earlier studies of hydrogen sulfide do not depend on a reduction in body temperature and include a substantial decrease in heart rate without a drop in blood pressure.

"Hydrogen sulfide is the stinky gas that can kill workers who encounter it in sewers; but when adminstered to mice in small, controlled doses, within minutes it produces what appears to be totally reversible metabolic suppression," says Warren Zapol, MD, chief of Anesthesia and Critical Care at MGH and senior author of the Anesthesiology study. "This is as close to instant suspended animation as you can get, and the preservation of cardiac contraction, blood pressure and organ perfusion is remarkable."

Previous investigations into the effects of low-dose hydrogen sulfide showed that the gas could lower body temperature and metabolic rate and also improved survival of mice whose oxygen supply had been restricted. But since hypothermia itself cuts metabolic needs, it was unclear whether the reduced body temperature was responsible for the other observed effects. The current study was designed to investigate both that question and the effects of hydrogen sulfide inhalation on the cardiovascular system.

The researchers measured factors such as heart rate, blood pressure, body temperature, respiration and physical activity in normal mice exposed to low-dose (80 ppm) hydrogen sulfide for several hours. They analyzed cardiac function with electrocardiograms and echocardiography and measured blood gas levels. While some mice were studied at room temperature, others were kept in a warm environment - about 98º F - to prevent their body temperatures from dropping.

In all the mice, metabolic measurements such as consumption of oxygen and production of carbon dioxide dropped in as little as 10 minutes after they began inhaling hydrogen sulfide, remained low as long as the gas was administered, and returned to normal within 30 minutes of the resumption of a normal air supply. The animals' heart rate dropped nearly 50 percent during hydrogen sulfide adminstration, but there was no significant change in blood pressure or the strength of the heart beat. While respiration rate also decreased, there were no changes in blood oxygen levels, suggesting that vital organs were not at risk of oxygen starvation.

The mice kept at room temperature had the same drop in body temperature seen in earlier studies, but those in the warm environment maintained normal body temperatures. The same metabolic and cardiovascular changes were seen in both groups, indicating that they did not depend on the reduced body temperature, and analyzing the timing of those changes showed that metabolic reduction actually began before body temperature dropped.

"Producing a reversible hypometabolic state could allow organ function to be preserved when oxygen supply is limited, such as after a traumatic injury," says Gian Paolo Volpato, MD, MGH Anesthesiology research fellow and lead author of the study. "We don't know yet if these results will be transferable to humans, so our next step will be to study the use of hydrogen sulfide in larger mammals."

Zapol adds, "It could be that inhaled hydrogen sulfide will only be useful in small animals and we'll need to use intravenous drugs that can deliver hydrogen sulfide to vital organs to prevent lung toxicity in larger animals." Zapol is the Reginald Jenney Professor of Anaesthesia at Harvard Medical School.