After an unpleasant encounter with roommates or coworkers, it’s always nice to go out, get some fresh air, and perhaps blow off steam by kvetching to friends or loved ones. But your usual methods of coping won’t save you when you’re 30 million miles from Earth, hurtling through space toward the red planet with the better part of a year remaining before you’re allowed to experience the creature comforts and normal human contact of that pale blue dot you call home. On a manned mission to Mars, crew members would face exactly those psychological pressures, so Russia’s Institute for Biomedical Problems will be carrying out a 520 to 700 day simulation to see whether crew members could withstand the mental trials. Six subjects with live in a mock-up spaceship consisting of five interconnected modules. They will have no contact with the outside world, save communications with “mission control,” which will be delayed by up to 40 minutes to simulate the actual time it would take messages to travel between Earth and Mars. They will eat only the finest in prepackaged meal packets, and minor emergencies (little things like appendicitis) will have to be handled by the isolated crew members. The gender split has yet to be determined. Some think six members of one sex would be problematic because the crew would lack the calming presence and unique insight of the opposite sex, five to one could lead to extreme sexual rivalry, and three-three could precipitate “gender tribalism.” Says Marc Heppener of the ESA Science and Application Division, “Four and two might be appropriate.”
Brothers have been known to go to extreme measures to protect their sisters’ purity, but this is just ridiculous: According to research recently published in the Proceedings of the National Academy of Sciences, women with male twins are 15 percent less likely to marry and 25 percent less likely to have children than women with female twins. The brothers aren’t actively fighting off potential suitors, though; the researchers hypothesize that female fetuses with male twins are exposed to a high volume of testosterone and that could damage their fertility. Having a male twin could also help women develop more masculine traits and behaviors, which may impact their interest in marriage, the researchers suggest. Male and female fetuses are exposed to roughly the same amount of estrogen in utero, so it is unlikely that males are affected in a similar way. The researchers conducted their analysis on records of 754 Finnish twins living between 1734 and 1888, before techniques like IVF could have altered fertility.
Man Bites Man
If you’re a man in a bar on a weekend, and some drunk patron is trying to provoke you, you probably shouldn’t assume his bark is worse than his bite. According to a study recently published in the Emergency Medical Journal, intoxication, in fact, is how most human bite injuries come to be. The authors examined 92 patients referred to the plastic surgery unit of St. James’s Hospital in Dublin for human bites. Of these, they found that 92 percent of human bite victims were men, making a man 12 times as likely as a woman to be bitten by his fellow man. 86 percent of the injuries were related to alcohol consumption, and 70 percent of biting incidents happened on a weekend or public holiday. Just under half of all bites requiring a hospital visit were to the ear, in the fine tradition of the notorious 1997 Tyson-Holyfield boxing match.
Folklore endows blind people with mysteriously heightened senses and abilities that compensate for their lack of sight. A new study, published in the journal Current Biology suggests there may actually be some truth to this idea. Researchers used both blind and sighted subjects to find that the congenitally blind not only have excellent memory in general but also have especially superior “serial memory,” the ability to remember things in order. Researchers read a list of 20 words to the subjects. The subjects were then asked to identify not only the words but also the order in which they were read. Blind subjects were able to remember more words than sighted subjects, and they were far better at remembering long word sequences in the correct order. The researchers suggest that their advantage comes not from an innate ability but rather from years of practice. “[T]he blind tend to code spatial information in the form of ‘route-like’ sequential representations,” the authors write. “Thus, serial memory, indicating the order in which items are encountered, may be especially important for the blind to generate a mental picture of the world.”
The Price of Selling
While in many countries, such as Germany, Japan, and Iran, fewer than 0.2 percent of the population is infected with HIV, in some central and southern African countries, HIV/AIDS prevalence rates are in the 25 percent to 35 percent range. According to a study recently published in PLoS One, HIV/AIDS prevalence is robustly correlated with the number of female commercial sex workers as a percentage of the female adult population. The authors took data on infection prevalence and commercial sex worker population from 77 countries around the world and created a linear regression. The authors note that Africa has both a high number of commercial sex workers (nearly 4 percent, on average, in the countries surveyed) and a high percent of HIV/AIDS prevalence among those sex workers (over 40 percent). They also note that female illiteracy levels, gender illiteracy differences, income inequality are also strongly correlated with HIV/AIDS prevalence. Muslims as a percentage of the population, however, is not positively correlated with HIV/AIDS prevalence, even though it is correlated with circumcision rates. The authors therefore conclude that circumcision is not the key to slowing the AIDS epidemic.
Originally published June 25, 2007