A roundup of the good, the bad and the just plain interesting from the week's science headlines:
Scientists were examining some unusual bright flecks Thursday after NASA's Mars rover Curiosity ate dirt for the first time, Reuters said. Curiosity's sample of Martian ground was about the size of a baby aspirin, and is the first step in testing equipment that will evaluate whether Mars could support, or has ever supported, microbial life. The flecks could be debris from the rover, but most of the team thinks the flecks are some sort of naturally occurring mineral, the news agency reported.
Maybe you feel you can function on a few hours of sleep, but your fat cells know otherwise. It's generally accepted that the main point of sleep is to recharge the brain. But scientists examining the effects of sleep deprivation – in this case, getting 4.5 hours of sleep instead of 8.5 hours – found a 30 per cent reduction in fat cells' ability to respond to insulin in the study's seven participants. The hormone insulin regulates energy, and this University of Chicago study directly links the effects of disturbed energy regulation, which can result in weight gain and diabetes, to not getting enough sleep. The research was published Wednesday in the Annals of Internal Medicine.
- In other planetary developments, another study released this week adds credence to a different theory of why the Earth and its moon are so similar in composition. The prevalent theory about the moon's formation says a planetary body, Theia, collided with Earth. Logically, the moon's composition should be similar to Theia but it's not: its chemistry resembles that of Earth. In a new paper published Wednesday in the journal Science, scientists suggest a fast-spinning baby Earth (an average day would last two to three hours) launched material into orbit when it was struck by Theia, and that part of Earth became the moon.
- Brain size relative to body size is used by scientists to predict intelligence. But evolutionary changes to the brain might not be what makes some animals smarter than others, say a team of scientists in a University College London press statement. A new study published Monday showed changes in body size – such as bats gradually becoming smaller, increasing their relative brain size –is often the most significant factor, challenging the previous assumption that evolutionary growth in brain size is key to smarter creatures. In fact, most of the animals studied grew faster in body than in brain size.
- Can motherhood mute the effects of cocaine? Compared to virgin rats, mother rats had less dopamine – the chemical that causes a drug’s ‘high’ – released in their brains’ pleasure centres after cocaine exposure, University of Michigan researchers said in a press release. The researchers also had the rats poke their noses against a dispenser to get their fix as part of the study. Mother rats were more likely to get a drug fix after a short, stressful situation. However, as scientists upped the number of pokes needed to deliver the drug, mother rats were more likely to give up. The study adds to scientific understanding of different factors affecting drug use. The findings were presented Monday at the Neuroscience 2012 annual meeting.