Muscles Remember Their Strength

Exercising is easier for people who have worked out earlier in life. A new study shows that muscles retain a memory of their former fitness even as they wither from lack of use. Musucles seem to have both long and short term memory.

The memory is stored in the cells of the muscle. Muscle cells are huge. Because the cells are so big more than one nucleus is needed to supply the amount of protein needed for muscular strength. When you exercise muscle cells get even bigger by merging with satellite cells. Previously researchers thought that when muscles atrophy, the extra cells that had merged would be killed off. A new study suggests that the nuclei do not die-which means.

Headphone Use Increases Hearing Loss in Teens

1-in-5 U.S. Teenagers has Slight Hearing Loss

Some experts are urging teenagers to turn down the volume on their digital music players, suggesting loud music through earbuds may be to blame. Researchers analyzed data on 12- to 19-year-olds from a nationwide health survey. They compared hearing loss in nearly 3,000 kids tested from 1988-94 to nearly 1,800 kids tested over 2005-06. The prevalence of hearing loss increased from about 15 percent to 19.5 percent.

Most of the hearing loss was "slight," defined as inability to hear at 16 to 24 decibels – or sounds such as a whisper or rustling leaves. A teenager with slight hearing loss might not be able to hear water dripping or his mother whispering "good night." Extrapolating to the nation's teens, that would mean about 6.5 million with at least slight hearing loss.

ADHD Linked to Pesticide Exposure

Chemicals on our produce may contribute to behavior problems in our kids, suggest three new studies. The studies, which looked at a class of pesticides called organophosphates (OP), linked exposure to the chemicals with attention disorders in children, with perhaps the most dramatic impacts to kids who are exposed in the womb and those who are genetically most susceptible. Because pesticide residues linger on fruits and vegetables, the findings suggest that people either buy organic or take the time to wash their produce well.

Organophosphates are a set of common pesticides that work by attacking the nervous systems of insects. When people are exposed to high levels of the chemicals, they can develop anxiety, confusion impaired concentration, and other serious symptoms. More recently, scientists have started to wonder how chronic exposure at low levels might be affecting people, especially kids, whose nervous systems are still developing.

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