Revista Scientific American Abril 2017. Inglés

Descripción

Revista Scientific American Abril 2017. Inglés

ISSN: 0036-8733

Descripción

A Rare Success against Alzheimer's
A gold-standard clinical trial provides evidence that diet, exercise and an active social life can help prevent cognitive decline

More people are reaching a ripe old age than ever before. Life expectancy has increased from 45 years in the early 1800s to more than 80 today in most European countries and in Japan, Canada and Australia, among other nations. In fact, if the trend continues, a majority of babies born in these countries today will live past their 100th birthday. This greater longevity comes with some bad news. Although we manage to survive longer than preceding generations did, we often gain time without being healthier in those extra years. Studies from different parts of the world indicate that after age 60, most people have at least one chronic disorder, such as heart disease or diabetes, and a recent population-based study in Sweden found that at 80, only around one out of 10 individuals was free of chronic diseases. In fact, most people older than 80 in this population had two or more chronic illnesses.

Shredded Stars Offer New View of Supermassive Black Holes
New techniques reveal how supermassive black holes shred entire stars

At the heart of our Milky Way and of virtually every other large galaxy lurks a deep cosmic mystery a supermassive black hole. Squeezing millions to billions of times more mass than our sun into regions smaller in size than our solar system, these objects are so bizarre as to seem almost mystical. No one yet understands exactly how nature has managed to compress so much matter into such small spaces. What is clear is that the hidden gravitational hands of supermassive black holes reach out to shape their surrounding galaxies in profound yet subtle ways. By studying the growth and behavior of these ghostly black holes, scientists hope to unlock the secrets of how galaxies themselves are born and evolve.

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