SciTech Briefs

Identical Twins Live Longer

According to a recent study by the University of Washington. The study is the first of its kind to analyze what being a twin means for life expectancy. Lead author of the study David Sharrow says his team found that “at nearly every age, identical twins survive at a higher proportion than fraternal twins, and fraternal twins are a little higher than the general population.” Their data comes from the Danish Twin Registry, from which the scientists examined nearly 3,000 pairs of identical twins born in Denmark between 1870 and 1900, all having survived past the age of 10. They found that 6 percent more male twins survived into their mid-40’s than did males of the general population, with a higher difference of 10 percent for female twins. The authors of the study think their results show the benefits of having a close social relationship with someone. By having such a close personal bond as twins do, they say it can provide healthy outlets and activities, and “provide material or emotional support that lead to better longevity outcomes.” Researchers think this study has implications beyond twins, and that close social relationships for anyone could have positive effects on longevity.

Source: Science Daily

3-D Molecules Displayed in a New Way

Researchers at the Department of Energy’s Lawrence Berkeley National Laboratory and UC Berkeley have created a type of “display case” that allows for new atomic-scale views of molecules that have previously been difficult to examine. This new form of display can help reveal structural details of molecules that were not previously known in order to aid research on chemically complex compounds and even new drugs. This new form of display works by stabilizing the molecules inside what the scientists call “metal-organic frameworks”, or MOFs. The researchers introduced molecules that were chemically bound to the MOFs, and then used x-ray techniques to precisely determine the molecular structure of the molecules. The molecules used in the study range from simple alcohol to complex plant hormones, and the MOFs used are easy to manufacture in large numbers. This is critical because the MOFs are most useful in that they can determine a molecules “chirality” by selectively binding with molecules that possess the same chirality as the MOF. Chirality is best explained as left vs. right-handedness, and it is crucial for pharmaceutical companies to know because it can determine the difference between a medicine and a poison. According to researchers, the scientific potential of the MOF is groundbreaking.

Source: Science Daily

Eating turns off nerve cells that counter obesity

Researchers at the Francis Crick Institute in London have found that eating shuts down a group of specialized nerve cells in mice, designed to energize. Once eating stops, these nerve cells reactivate. These nerve cells are providing scientists with new clues about how the brain controls appetitie. The cells produce a chemical called orexin (or hypocretin), which has been thought to have a role in appetite for years. The cells are so perplexing because they are largely absent from people with narcolepsy, and narcoleptic people are more likely to be overweight than a non-narcoleptic person. When scientists used a genetic technique to remove the orexin cells from mice, they found that the mice at more than normal, which led to weight gain. The results of the study suggest that giving orexin to people like narcoleptics who lack it could reduce obesity, the researchers also warn against its adverse effects. Study coauthor Denis Burkadov says an overactive orexin system can lead to stress and anxiety, which also raises the possibility that anxiety can be reduced by decreasing orexin cell activity. He also says it provides “an explanation for why people eat in times of anxiety.”

Source: Science News

Hoverflies probably can’t sense gravity

Insects known for flying in dramatic patterns at high speeds, such as dragonflies and hoverflies have to execute turns with great precision, but scientists have never known whether or not they use gravity to control themselves. Roman Goulard of Aix-Marseille University in France simulated gravity by dropping hoverflies in different lab environments and observing how they react to free-fall. In a dark box, 70 percent of flies were too slow to beat their wings and crashed. In a light box, the insects had better reaction speed, but many still crashed. The final box was light with striped walls and the flies were much faster to beat their wings with only 10 percent of the flies crashing. While the study does not completely prove that hoverflies do not sense gravity, the insects still do not have a means to sense acceleration. This means that they must use only sight and airflow to determine their location in space.

Source: Science News

Satellite images predicting poverty

A team of researchers at Stanford University trained a computer system to identify impoverished areas from survey and satellite data in five African countries. Neal Jean and Marshall Burke of the research team say that their system can transform the way we track and target poverty. Poverty data has traditionally been collected by household surveys, sending people to houses and asking questions about income and consumption. However, these surveys are costly, hard to keep recent, and impossible in certain areas of the world due to conflict. This new model looks at a plethora of factors to determine an area in poverty, like paved roads, metal roofs, urban areas, farmland, and many other things in imagery that are predicative of poverty. Burke explained that the model is “surprisingly predicative of economic livelihoods in these countries.” An assistant professor at UC Berkeley, Joshua Blumenstock, said this model can ultimately “help ensure that resources get to those with the greatest need.”

Source: BBC

New species of ancient dolphin identified

After spending decades in the Smithsonian Museum of Natural history in Washington, D.C., scientists from the museum have re-examined a skull that belonged to a previously unrecognized species. The skull is believed to belong to a relative of the South Asian river dolphin, an endangered species. The skull is only partial, is about nine inches in length and was discovered in 1951 in Alaska by geologist Donald J. Miller. The new study’s authors Alexandra Boersma and Nicholas Pyenson say that the dolphin swam in sub-arctic waters about 25 million years ago, and represents a new species named Arktocara yakataga. Scientists estimate that Arkotcara came from the late Oligocene epoch, around the time that whales split into two classes of baleen whales and toothed whales. The team determined that Arktocara, previously known as Platanista, is indeed a relative of the South Asian river dolphin, which means that the endangered species is the last living relative of a once widespread group of dolphins. Scientists say that while they know the relationship, how a once diverse and widespread group came down to single species in Southeast Asia is still a mystery.

Source: BBC