MI weekly selection #154
Mars atmosphere stripped away by solar storms
Solar storms have been stripping away the air on Mars, according to data collected by NASA’s Maven spacecraft. Researchers say this could help explain why Mars’ atmosphere became so thin so rapidly, turning a once warm planet with liquid water into the dry, desolate landscape it is today.
Land creatures may not have perished in Permian die-off
New data about the extinction of the Dicynodon suggests that the die-off of about three-quarters of land species may not have occurred alongside that of 90% of marine species during the Permian extinction. Researchers say their findings raise questions about whether a mass die-off of land creatures occurred at all. The scientists dated the Dicynodon’s extinction to about 1.3 million years before the Permian event by studying rocks in the Karoo Basin in South Africa, where fossilized animals and plants are embedded.
Light on fish size, sight capabilities
A pair of studies add to knowledge about fish size and their vision capabilities. A study published in Nature details how salmon size is controlled by the same gene in males and females, but acts differently in each gender. Males reach maturity earlier when they are smaller, and females reach maturity later when much larger. The second study, published in Current Biology, describes a newly discovered enzyme that allows fish to see better in areas of poor visibility.
Insulin resistance tied to sleep-disordered breathing during REM sleep
An association has been showed between the apnea-hypopnea index — used to quantify sleep-disordered breathing — during rapid eye movement sleep and insulin resistance, but not with fasting glycemia or glucose intolerance. Researchers used a cohort of 3,310 participants whose fasting and two-hour post-challenge glucose levels, as well as the homeostatic model assessment index for insulin resistance, were measured.
High dose of vitamin C can kill a type of cancer cells in mice
High doses of vitamin C have been used to destroy cells with a common mutation that causes cancer and to limit tumor growth in mice, according to a study published online in Science. Researchers are hoping to start clinical trials on cancer patients with KRAS or BRAF cancer-cell mutations.