This Week in Science – January 24, 2014

By Amanda Spadaro

A study conducted by Swedish professors at Umeå University found that lean, unfit men are less likely to experience heart attacks than obese, fit men. Over 700,000 Swedish men participated in the study, using data from those conscripted into national service from 1969 to 1984. The researchers followed the men until their first heart attack or until January 2011, whichever came first. Among the results, the study found that fitness through the teenage years can reduce the risk of an early heart attack by up to 35 percent. As fitness levels increased by 15 percent, adjusting for other factors like socioeconomic status, the chance of having a heart attack in the next 30 years decreased by 18 percent. However, fitness is not the only factor that can contribute to decreasing the risk of heart attacks: “While being physically fit at the end of your teens can reduce the risk of heart attack, fitness alone does not appear to fully compensate for the risks with being overweight or obese. In other words, having a normal weight is more important than being in good physical shape, but it is even better to be both fit and have a normal weight,” said Peter Nordstrom to Wired, one of the researchers on the project. Nordstrom hopes that this information can be used in public health planning.

A team of researchers from the Federal University of Amazonas in Brazil discovered a new species of river dolphin, the first to be identified since World War I. Due to a barrage of genetic analysis, scientists determined that the river dolphin was a separate species, also supported by the different number of teeth and size of the dolphin. As only the fifth river dolphin known, the dolphin inhabits the Araguaia River, but scientists already believe the species to be endangered. Inia araguaiaensis, named after the river, has an estimated population of only 1,000. However, three river dolphin populations are already on the Red List for threatened species. Due to the expanding human pressure in the area, the dolphins are losing precious space and resources. Hydroelectric dams have isolated these dolphins from one another and the major fishing industry affects the dolphins’ food supply. In addition, the population has little genetic diversity and this, coupled with the small size of the population as a whole, makes I. araguaiaensis particularly susceptible to damaging population events.

Biologists at the University of Texas MD Anderson Cancer Centre has suggested the ability to test for multiple cancers using an early diagnostic blood test. The researchers have discovered that particles called exosomes in the blood contain large sections of DNA which can then be tested for known genetic mutations that lead to cancer. These pieces of DNA actually end up in the bloodstream from other tissues of the body, enabling testing for multiple types of cancer without needing to get samples directly from that particular tissue. The current types of blood tests used in diagnosing cancer focus on cell count and the presence of proteins produced by tumors. This may open the door for early testing when tumors and other diagnostic tools are not yet able to be detected. In a clinical study, a gene and protein mutation associated with pancreatic cancer was identified in the exosome DNA. However, more investigation into the matter is necessary, especially when this type of testing would be applied to the population at large, admitted lead author Raghu Kalluri to Wired.

The U.S. Department of Agriculture conducted a recent study that suggests that honeybee colony collapse may be due, in part, to a quickly mutating virus that has moved from pollinating plant species to honeybees. The pathogen is tobacco ringspot virus, which can affect soy crops by causing blight, is a pollen-borne infection. However, honeybees that become infected may transmit the virus among the colony through mites that travel from bee to bee. Researches are also unsure of whether or not honeybees may also spread this infection back to plants as well. Commercial colonies have been affected largely by this, as the pathogen can spread systematically through the entire hive. These colonies are also responsible for pollinated approximately 90 crops internationally, which can be worth upwards of $14 billion per year. In addition to this newly discovered virus in honeybees, pesticides and beekeeping methods may also hinder the bees’ immune system, making it difficult for the bees to fight infection. The pathogen is considered a “quasi-species,” meaning that it can mutate and replicate rapidly in ways to subvert the immune system. For colonies that face a number of additional stressors, this infection could have serious ramifications as the researchers identified a correlation between the presence of the virus in colonies already considered weak due to environmental stresses. “I’d be hesitant to proclaim that this virus is the cause of colony collapse, but it certainly shows the degree of our lack of understanding of the complexity of bee pathogen interactions,” Randy Oliver, beekeeper and biologist, said to the Los Angeles Times.

A study conducted under Dr. Philipp Henschel of the Lion Survey Program Coordinator for Panthera, a wild cat conservation organization, found that the West African lion is facing extinction. Beginning in 2006, Henschel and his team of researchers started surveying in 21 known, protected areas, but they soon found that many of these areas no longer had any surviving West African lions, which Henschel called, “a complete shock,” to the National Monitor. The team posits that there are only 406 lions remaining in the wild, approximately 250 of breeding age. The lions are believed to currently live in five countries: Benin, Burkina Faso, Niger, Nigeria and Senegal. This represents 1.1 percent of the historic range of the West African lion as much of their land has been developed agriculturally. In addition to agricultural development, these lions have faced hunting and poaching as well as human expansion in the region. Because West Africa is home to some of the most poverty-stricken areas, though, government funding for conservation may also be significantly lacking. “We are talking about some of the poorest counties in the world. Many governments have bigger problems than protecting lions,” Henschel said to BBC News.

However, Dr. Luke Hunter, study co-author and Panthera President, has stated that this funding is exactly what is needed for conservation of the species. “To save the lion – and many other critically endangered mammals including unique populations of cheetahs, African wild dogs and elephants – will require a massive commitment of resources from the international community,” he said to National Monitor.