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The North American Spine Society and the Society of Interventional Radiology have pointed to flaws in both studies. And earlier studies, published over 15 years, found major benefits to kyphoplasty and a related procedure called vertebroplasty. "We're missing opportunities for patients to receive a safe and effective treatment that can significantly reduce their pain and disability," said Malamis, an interventional radiologist. The procedures are used to treat vertebral compression fractures in patients with osteoporosis and other conditions that result in brittle bones. In a vertebroplasty, an acrylic cement is injected into a fractured vertebra. In a kyphoplasty, a balloon-tipped catheter first is inserted into the fracture. The balloon is inflated to restore the height and shape of the vertebra before the cement is injected. Neva Nelson, 74, of Naperville, Ill., said a kyphoplasty that Malamis performed in October, 2009, has greatly reduced her pain in a vertebra in her lower back that she fractured after falling on ice. Before her kyphoplasty, Nelson had to sit on cushions. Walking, and especially standing, were painful. "I had to do something," she said. "I could not go on like that." Nelson said that since undergoing her kyphoplasty, "I don't have to worry about my back any more." In the controversial studies, patients were randomly assigned to receive a vertebroplasty or a placebo-like "sham" procedure. In the sham procedure, patients received an injection of anesthetic, but no cement. However, patients in severe pain are reluctant to enroll in a trial where there's a 50 percent chance of receiving a sham treatment. In one of the studies, researchers had to screen 1,813 patients to enroll just 131 subjects. In the other study, only 78 of 219 eligible patients were enrolled. This low enrollment rate raises the possibility that the patients who did enroll were not representative. Patients experience the greatest pain during the first three months after a compression fracture. Thereafter, pain gradually subsides. Thus, a vertebroplasty or kyphoplasty provides the greatest benefit when performed within a week or two of the fracture. But the studies enrolled patients up to 12 months after fractures. In addition to reducing pain and disability, a kyphoplasty can reduce the risk of subsequent fractures by improving the angle and height of the spine. The studies evaluated vertebroplasty alone, and did not include the more innovative and very different kyphoplasty procedure. Malamis suggests the medical community wait for the results of additional studies now underway before passing final judgment on vertebroplasty or kyphoplasty. In the mean time, he notes that Medicare still covers the procedures.

This is the largest nationally representative study to date of the toll taken by sepsis and pneumonia, two conditions often caused by deadly microbes, including the antibiotic-resistant bacteria MRSA. Such infections can lead to longer hospital stays, serious complications and even death. "In many cases, these conditions could have been avoided with better infection control in hospitals," said Ramanan Laxminarayan, Ph.D., principal investigator for Extending the Cure, a project examining antibiotic resistance based at the Washington, D.C. think-tank Resources for the Future. "Infections that are acquired during the course of a hospital stay cost the United States a staggering amount in terms of lives lost and health care costs," he said. "Hospitals and other health care providers must act now to protect patients from this growing menace." Laxminarayan and his colleagues analyzed 69 million discharge records from hospitals in 40 states and identified two conditions caused by health care-associated infections: sepsis, a potentially lethal systemic response to infection and pneumonia, an infection of the lungs and respiratory tract. The researchers looked at infections that developed after hospitalization. They zeroed in on infections that are often preventable, like a serious bloodstream infection that occurs because of a lapse in sterile technique during surgery, and discovered that the cost of such infections can be quite high: For example, people who developed sepsis after surgery stayed in the hospital 11 days longer and the infections cost an extra $33,000 to treat per person. Even worse, the team found that nearly 20 percent of people who developed sepsis after surgery died as a result of the infection. "That's the tragedy of such cases," said Anup Malani, a study co-author, investigator at Extending the Cure, and professor at the University of Chicago. "In some cases, relatively healthy people check into the hospital for routine surgery. They develop sepsis because of a lapse in infection control—and they can die." The team also looked at pneumonia, an infection that can set in if a disease-causing microbe gets into the lungs—in some cases when a dirty ventilator tube is used. They found that people who developed pneumonia after surgery, which is also thought to be preventable, stayed in the hospital an extra 14 days. Such cases cost an extra $46,000 per person to treat. In 11 percent of the cases, the patient died as a result of the pneumonia infection.

Statistical validation of results, as Shaffer described it, simply involves testing the null hypothesis: that the pattern you detect in your data occurs at random. If you can reject the null hypothesis—and science and medicine have settled on rejecting it when there's only a five percent or less chance that it occurred at random—then you accept that your actual finding is significant. The problem now is that we're rapidly expanding our ability to do tests. Various speakers pointed to data sources as diverse as gene expression chips and the Sloan Digital Sky Survey, which provide tens of thousands of individual data points to analyze. At the same time, the growth of computing power has meant that we can ask many questions of these large data sets at once, and each one of these tests increases the prospects than an error will occur in a study; as Shaffer put it, "every decision increases your error prospects." She pointed out that dividing data into subgroups, which can often identify susceptible subpopulations, is also a decision, and increases the chances of a spurious error. Smaller populations are also more prone to random associations. In the end, Young noted, by the time you reach 61 tests, there's a 95 percent chance that you'll get a significant result at random. And, let's face it—researchers want to see a significant result, so there's a strong, unintentional bias towards trying different tests until something pops out. Young went on to describe a study, published in JAMA, that was a multiple testing train wreck: exposures to 275 chemicals were considered, 32 health outcomes were tracked, and 10 demographic variables were used as controls. That was about 8,800 different tests, and as many as 9 million ways of looking at the data once the demographics were considered.

Trade's effect on military conflict is one of the most important issues in international relations. The last decade has seen research and debate into the role of trade intensify; Liberals argue that trade brings peace, neo-realists and neo-Marxists reason that trade brings conflict, and classical realists contend that trade has no impact. This debate is not just academic: some key U.S. policymakers (Senator McCain and former President Clinton for instance) believe that trade brings peace, a view that contributes to their support for free trade. Economists developed bilateral trade models in isolation from models of interstate conflict, which were the work of political scientists. These two types of models handle distance between nations differently. Bilateral trade takes its cue from Isaac Newton's formula for the gravitational attraction between two objects: the larger the objects' masses and the shorter the distance between them, the larger the attraction. So the larger the trade partners' economies and the closer they are to one another, the greater their trade. However, conflict models instead incorporate shared borders by land or close distance over water (contiguity) - stressing the role of border disputes in sparking interstate conflict. Distance is included in conflict equations based on the idea that an army gets weaker the farther it strays from its base, but what point in a nation to pick for the trade and conflict equation is unclear. Often theorists use the distance between capital cities, which is problematic: wars generally happen around borders where armies are often based, and capitals have historically changed without this altering the likelihood of war between the nation and its neighbours. The authors suggest that the trade data set plugged into trade and conflict equations is critical. This type of data often contains gaps - there are a number of reasons why data from a particular nation might be unavailable, inevitably leaving researchers to make assumptions. The majority of trade and conflict studies define conflict to include all types of militarised interstate disputes (MIDs). But Keshk, Reuveny, and Pollins question the results generated when different conflict definitions are chosen. For instance, a conflict such as a threat to use nuclear weapons would not cause fatalities, but may still have some impact on trade and vice versa. In fact, by altering the data treatment and assumptions in the equation, the authors generated a variety of results, which supported several different theoretical viewpoints. The authors suggest that future research should investigate questions of missing bilateral trade data, and attempt a more subtle use of the meaning of "military conflict". Researchers might also develop distance and contiguity measures at a more sophisticated level. "Any signal that trade brings peace remains weak and inconsistent, regardless of the way proximity is modelled in the conflict equation. The signal that conflict reduces trade, in contrast, is strong and consistent," say the authors. "Any study of the effect of trade on conflict that ignores the reverse fact is practically guaranteed to produce estimates that contain simultaneity bias." Studies of the relationship between international trade and military conflict can be traced back many centuries, particularly in the works of luminaries such as de Montesquieu, Immanuel Kant, John Hobson, Vladimir Lenin, Henry Morgenthau, Kenneth Waltz, Frederic List, and Albert Hirschman. This latest study emphasises that international politics are affecting trade between nation pairs, while it is far less obvious whether trade systematically affects politics. "To our colleagues from the liberal camp we would like to say that we still believe there are limited circumstances in which more trade may help lead countries to more peaceful resolutions of their differences, particularly if they are already at peace," the authors state. "However, it is past time for academics and policymakers to look beyond the naive claim that the cultivation of trade ties will always and everywhere produce a more peaceful world."

Known as 'polyandry' among scientists, the phenomenon of females having multiple mates is shared across most animal species, from insects to mammals. This study suggests that polyandry reduces the risk of populations becoming extinct because of all-female broods being born. This can sometimes occur as a result of a sex-ratio distortion (SR) chromosome, which results in all of the Y chromosome 'male' sperm being killed before fertilisation. The all-female offspring will carry the SR chromosome, which will be passed on to their sons in turn resulting in more all-female broods. Eventually there will be no males and the population will die out. For this study, the scientists worked with the fruitfly Drosophila pseudoobscura. They gave some populations the opportunity to mate naturally, meaning that the females had multiple partners. The others were restricted to having one mate each. They bred several generations of these populations, so they could see how each fared over time. Over fifteen generations, five of the twelve populations that had been monogamous became extinct as a result of males dying out. The SR chromosome was far less prevalent in the populations in which females had the opportunity to have multiple mates and none of these populations became extinct. The study shows how having multiple mates can suppress the spread of the SR chromosome, making all-female broods a rarity. This is because males that carry the SR chromosome produce only half as many sperm as normal males. When a female mates with multiple males, their sperm will compete to fertilise her eggs. The few sperm produced by males carrying the SR chromosome are out-competed by the sperm from normal males, and the SR chromosome cannot spread.

"People tend to conform their factual beliefs to ones that are consistent with their cultural outlook, their world view," Braman says. The Cultural Cognition Project has conducted several experiments to back that up. Participants in these experiments are asked to describe their cultural beliefs. Some embrace new technology, authority and free enterprise. They are labeled the "individualistic" group. Others are suspicious of authority or of commerce and industry. Braman calls them "communitarians." In one experiment, Braman queried these subjects about something unfamiliar to them: nanotechnology — new research into tiny, molecule-sized objects that could lead to novel products. "These two groups start to polarize as soon as you start to describe some of the potential benefits and harms," Braman says. The individualists tended to like nanotechnology. The communitarians generally viewed it as dangerous. Both groups made their decisions based on the same information. "It doesn't matter whether you show them negative or positive information, they reject the information that is contrary to what they would like to believe, and they glom onto the positive information," Braman says.

"Basically the reason that people react in a close-minded way to information is that the implications of it threaten their values," says Dan Kahan, a law professor at Yale University and a member of The Cultural Cognition Project. Kahan says people test new information against their preexisting view of how the world should work. "If the implication, the outcome, can affirm your values, you think about it in a much more open-minded way," he says. And if the information doesn't, you tend to reject it. In another experiment, people read a United Nations study about the dangers of global warming. Then the researchers told the participants that the solution to global warming is to regulate industrial pollution. Many in the individualistic group then rejected the climate science. But when more nuclear power was offered as the solution, says Braman, "they said, you know, it turns out global warming is a serious problem."And for the communitarians, climate danger seemed less serious if the only solution was more nuclear power.

Cherkauer said he ran simulation models that show Indiana, Illinois, Wisconsin and Michigan could see as much as 28 percent more precipitation by the year 2070, with much of that coming during the winter and spring months. His projections also show drier summer and fall seasons. "This was already a difficult spring to plant because of how wet it was. If you were to add another inch or so of rain to that, it would be a problem," Cherkauer said. "It could make it difficult to get into fields. There's also a potential for more flooding." He calculated that winters in the four states could be 2.7 degrees to 5.4 degrees Fahrenheit warmer by 2077 than today. Summers could be 3.6 degrees to 10.8 degrees warmer. The NASA-funded study appears in the early online edition of the Journal of Great Lakes Research.

"How old you are matters, but beyond that it's your interpretation that has far-reaching implications for the process of aging," said Markus H. Schafer, a doctoral student in sociology and gerontology who led the study. "So, if you feel old beyond your own chronological years you are probably going to experience a lot of the downsides that we associate with aging. "But if you are older and maintain a sense of being younger, then that gives you an edge in maintaining a lot of the abilities you prize." Schafer and co-author Tetyana P. Shippee, a Purdue graduate who is a research associate at Purdue's Center on Aging and the Life Course, compared people's chronological age and their subjective age to determine which one has a greater influence on cognitive abilities during older adulthood. Nearly 500 people ages 55-74 were surveyed about aging in 1995 and 2005 as part of the National Survey of Midlife Development in the United States. In 1995, when people were asked what age do you feel most of the time, the majority identified with being 12 years younger than they actually were. "We found that these people who felt young for their age were more likely to have greater confidence about their cognitive abilities a decade later," Schafer said. "Yes, chronological age was important, but the subjective age had a stronger effect. "What we are not sure about is what comes first. Does a person's wellness and happiness affect their cognitive abilities or does a person's cognitive ability contribute to their sense of wellness. We are planning to address this in a future study."

"Exposure to BPA may be harmful during pregnancy; this exposure may permanently affect the fetus," said Hugh S. Taylor, Ph.D., co-author of the study from Yale University School of Medicine in New Haven, Connecticut. "We need to better identify the effects of environmental contaminants on not just crude measures such as birth defects, but also their effect in causing more subtle developmental errors." Taylor and colleagues made this discovery by exposing fetal mice to BPA during pregnancy and examining gene expression and DNA in the uteruses of female fetuses. Results showed that BPA exposure permanently affected the uterus by decreasing regulation of gene expression. These epigenetic changes caused the mice to over-respond to estrogen throughout adulthood, long after the BPA exposure. This suggests that early exposure to BPA genetically "programmed" the uterus to be hyper-responsive to estrogen. Extreme estrogen sensitivity can lead to fertility problems, advanced puberty, altered mammary development and reproductive function, as well as a variety of hormone-related cancers. BPA has been widely used in plastics and other materials. Examples include use in water bottles, baby bottles, epoxy resins used to coat food cans, and dental sealants. "The BPA baby bottle scare may be only the tip of the iceberg." said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Remember how diethylstilbestrol (DES) caused birth defects and cancers in young women whose mothers were given such hormones during pregnancy. We'd better watch out for BPA, which seems to carry similar epigenetic risks across the generations. "