If human CO2 emissions continue unabated, the earth could become a difficult place to live before the end of the century, according to a new study in PNAS.

Researchers from Purdue University and the University of New South Wales, Australia calculated the highest tolerable "wet-bulb" temperature and found that this temperature could be exceeded for the first time in human history if future climate change scenarios are to be believed.

Wet-bulb temperature is equivalent to what is felt when wet skin is exposed to moving air. It includes temperature and atmospheric humidity and is measured by covering a standard thermometer bulb with a wetted cloth and fully ventilating it.

Trees help keep the planet cool, but rising levels of carbon dioxide in the atmosphere are preventing them from performing this very important function.

According to a new study in PNAS, in some regions more than a quarter of the warming from increased carbon dioxide is due to its direct impact on vegetation. This warming is in addition to carbon dioxide's better-known effect as a heat-trapping greenhouse gas.

The new paper highlights the importance of including plants in the models that forecast future climate change.

Watching too much TV may make children fat, bad at math and expose them to all kinds of other evils, say "child experts" writing in the Archives of Pediatrics and Adolescent Medicine. The authors found that television exposure at age two forecasts negative consequences for kids, ranging from poor school adjustment to unhealthy habits.

Since TV exposure encourages a sedentary lifestyle, television viewing must be curbed for toddlers to avoid the maintenance of passive mental and physical habits in later childhood, the researchers conclude.

Scientists at the Georgia Institute of Technology have successfully altered the brain of one type of Cichlid fish to resemble that of another and discovered differences in the general patterning of the brain before neurogenesis occurs.

The findings, published in PNAS, challenge the popular theory known as “late equals large,” first proposed in the mid 1990s to explain the way brains evolve across species.

The brain begins as a blank slate. In early development, the anterior, or front, part of the brain is specified from the posterior, or back, part.


research team were able to alter the brain of an embryonic fish,

A new study of Australian preschoolers and Kalahari Bushman children suggests that overimitation, in which a child copies everything an adult shows them, appears to be a universal human activity, rather than something the children of western middle-class parents pick up. The research, published in Psychological Science, may help shed light on how humans develop and transmit culture.

Using ancient DNA preserved in bones from Siberian mammoths 25,000 to 43,000 years old, scientists have brought the primary component of the specimens' blood "back to life."

The seven-year research effort, detailed this week in Nature Genetics, reveals special evolutionary adaptations that allowed the mammoth to cool its extremities down in harsh Arctic conditions to minimize heat loss.

The findings will also help scientists study the DNA of other extinct species, such as Australian marsupials.