Proceedings of the National Academy of Sciences, September 8
In one of the more visually pleasing bits of science news, researchers put over-ripe bananas under an ultraviolet light and revealed the pretty patterns that appeared on the bananas’ skin. Each brown spot on a banana was ringed with a bright blue glowing halo, which the study suggests might serve as a signal to animals that the fruit is ready for eating. And speaking of eating: Another study notes that half of the fish consumed by people around the globe now comes from fish farms. This might sound like good news in the sustainability department–until you remember that those farms use feed made from wild fish harvested from the sea. Finally, researchers found new evidence that the most aggressive forms of prostate cancer are linked to a viral infection, and suggest that the virus could even be sexually transmitted. The results of the study could soon help screen for people with the more severe form of the cancer.
Nature Genetics, September
Three new genes have been linked to a person’s risk of developing Alzheimer’s, according to two separate research groups. Two of the genes play a part in clearing away the toxic amyloid proteins that form plaques in the brains of Alzheimer’s patients. While the research doesn’t have any immediate applications for treating Alzheimer’s, every bit of information helps as scientists seek to understand the origins of the baffling disease.
Nature, September 10
Researchers have determined how an infectious deer disease is spreading so rapidly through herds across North America. The brain infection, which leads to fatal chronic wasting disease, is spread by infectious agents called prions that appear in the feces of infected deer up to a year before they become ill, and remain in the soil until other deer ingest them while grazing. The study‘s results were surprising because the prions that give rise to the related mad cow disease are not shed by infected animals, but instead accumulate in the brain and spinal cord. Moving from the animal to the plant kingdom, scientists also decoded the genome of the potato fungus responsible for the Irish potato famine in the 1800s, and which still troubles farmers around the world. The study found that the fungus has an usually large genome, allowing the pathogen to adapt to new conditions and target new plant strains that are supposed to be resistant to the blight.
Science, September 11
The Arctic is changing so quickly as a result of global warming that iconic animals like narwhales, walruses, seals, and polar bears are facing serious threats; some of these species could even go extinct before the end of the 21st century, a new report warns. The comprehensive study looked at ecological damage across polar ecosystems, and found that loss of sea ice, changing patterns of plant growth, and encroaching invasive species are making it harder and harder for native animals to survive. But maybe our extremely efficient brains will figure out a way out of this mess. Another study re-examined an old model of brain function that assumed that it takes a lot of energy for a brain cell to send out an electrical pulse–i.e., a message. Researchers realized the model was based on studies conducted in squid, which have conveniently large neurons that are easy to work on, and decided it would probably be a good idea to check the energy efficiency of mammal brain cells. Turns out, a rat neuron uses only a third as much energy as a squid neuron, which means our human brains are probably equally efficient.