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Dengue fever causes severe flulike symptoms and is among the world's most pressing public health issues. There are 50 million to 100 million cases per year, and nearly 40 percent of the global population is at risk. The dengue virus is spread through the bite of infected female Aedes aegypti mosquitoes, and there is no vaccine or treatment. UCI researchers and colleagues from Oxitec Ltd. and the University of Oxford created the new breed. Flightless females are expected to die quickly in the wild, curtailing the number of mosquitoes and reducing - or even eliminating - dengue transmission. Males of the strain can fly but do not bite or convey disease. When genetically altered male mosquitoes mate with wild females and pass on their genes, females of the next generation are unable to fly. Scientists estimate that if released, the new breed could sustainably suppress the native mosquito population in six to nine months. The approach offers a safe, efficient alternative to harmful insecticides.

The study authors, led by Rachel Manber, PhD, professor of psychiatry and behavioral sciences, said they hope the results will raise awareness of the problem of depression during pregnancy and provide patients and physicians an alternative to antidepressants. "This standardized acupuncture protocol could be a viable treatment option for depression during pregnancy," they wrote in a paper that will appear in the March issue of Obstetrics & Gynecology. Up to 14 percent of pregnant women may have major depressive disorder, a condition characterized by feelings of dread, gloom and hopelessness, and a loss of interest in normally pleasurable activities. Some women suffer from depression before becoming pregnant, stop taking their medication and then experience a relapse; in other women, pregnancy itself may cause depression.

For this study, the researchers recruited 150 women whose pregnancies were between 12 and 30 weeks gestation and who met the criteria for major depressive disorder. The women were randomized to receive one of three treatments: acupuncture specific for depression; control acupuncture, during which needles were inserted in points not known to help alleviate depressive symptoms; or massage. All of the women received eight weeks of therapy and were assessed for depression at the four- and eight-week marks by an interviewer who was unaware of the treatment each woman received. The researchers found that women who received the depression-specific acupuncture experienced a bigger reduction in depression symptoms than the women in the other groups. The response rate — defined as having a 50 percent or greater reduction in symptoms — was 63 percent for the women receiving depression-specific acupuncture, compared with 44 percent for the women in the other two treatment groups combined. The researchers weren't surprised by what they found — a pilot study yielded similar results, and other studies have shown acupuncture is an effective treatment for depression in the general public — but they were pleased with the results. "I don't think that one-size-fits-all treatments are appropriate for everyone, but acupuncture should be considered as an option," said Lyell. "I hope that people will respect the rigorous methodology used in this blinded, randomized, controlled trial and accept the result: Traditional acupuncture was associated with a significant improvement in depression."

In his new book, "The Double Helix and the Law of Evidence" (Harvard University Press), Kaye focuses on the intersection of science and law, and emphasizes that DNA evidence is merely information. "There's a popular perception that with DNA, you get results," Kaye said. "You're either guilty or innocent, and the DNA speaks the truth. That goes too far. DNA is a tool. Perhaps in many cases it's open and shut, in other cases it's not. There's ambiguity."

One of the book's key themes is that using science in court is hard to do right. "It requires lawyers and judges to understand a lot about the science," Kaye noted. "They don't have to be scientists or technicians, but they do have to know enough to understand what's going on and whether the statements that experts are making are well-founded. The lawyers need to be able to translate that information into a form that a judge or a jury can understand." Kaye also believes that lawyers need to better understand statistics and probability, an area that has traditionally been neglected in law school curricula. His book attempts to close this gap in understanding with several sections on genetic science and probability. The book also contends that scientists, too, have contributed to the false sense of certainty, when they are so often led by either side of one particular case to take an extreme position. Scientists need to approach their role as experts less as partisans and more as defenders of truth. Aiming to be a definitive history of the use of DNA evidence, "The Double Helix and the Law of Evidence" chronicles precedent-setting criminal trials, battles among factions of the scientific community and a multitude of issues with the use of probability and statistics related to DNA. From the Simpson trial to the search for the last Russian Tsar, Kaye tells the story of how DNA science has impacted society. He delves into the history of the application of DNA science and probability within the legal system and depicts its advances and setbacks.

"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."

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.

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.

Scanning electron micrograph of the nanofossil Chiasmolithus from about 60 million years ago. This genus arose after the Cretacious Paleogene boundary mass extinction. The size about 8 microns.

The darkness caused by the collision would impair photosynthesis and reduce nannoplankton reproduction. While full darkness did not occur, the effects in the north would have lasted for up to six months. However, with ample sunlight and large amounts of nutrients in the oceans, the populations should have bounced back, even in the North, but they did not. The researchers suggest that toxic metals that where part of the asteroid, heavily contaminated the Northern oceans and were the major factor inhibiting recovery. "Metal loading is a great potential mechanism to delay recovery," said Bralower. "Toxic levels in the parts per billions of copper, nickel, cadmium and iron could have inhibited recovery." On the one hand, the researchers considered an impact scenario causing perpetual winter and ocean acidification to explain the slow recovery, but neither explains the lag between Southern and Northern Hemispheres. Trace metal poisoning, on the other hand, would have been severe near the impact in the Northern Hemisphere. When the high temperature debris from the impact hit the water, copper, chromium, aluminum, mercury and lead would have dissolved into the seawater at likely lethal levels for plankton. Iron, zinc and manganese -- normally micronutrients -- would reach harmful levels shortly after the impact. Other metal sources might be acid-rain leached soils or the effects of wildfires. Metals like these can inhibit reproduction or shell formation. The toxic metals probably exceeded the ability of organic compounds to bind them and remove them from the system. Because nannoplankton are the base of the food chain, larger organisms concentrate any metals found in nannoplankton making the metal poisoning more effective. With the toxic metals remaining in the oceans and the lack of sunlight, the length of time for recovery might increase.