After some digging, they realized that the brighter lights corresponded with the holy month of Ramadan -- a period when Muslims fast during the day and gather to eat after the sun sets. Ramadan starts about a week and a half earlier every year. Sure enough, the changes in nighttime light in Cairo synced up with the Islamic calendar.
Then they turned their attention to cities in the United States. They had to focus on places without snow, since snow reflects too much light. In the cities they did analyze, they corrected for the light effects of clouds, aerosols and even the reflection of the moon.
The researchers created images to compare the light output during the holiday season with the light measured during the rest of the year. The greater the increase, the greener an area appears. In cities such as Atlanta, Dallas, Houston, Los Angeles, Miami, Phoenix, Sacramento and San Jose, the nighttime light during the weeks between Black Friday and New Year’s Day rose by as much as 50%.
“These new data reveal worrisome patterns in the prescribing of benzodiazepines for older adults, and women in particular,” said Thomas Insel, M.D., director of the National Institute of Mental Health (NIMH), which supported the study. “This analysis suggests that prescriptions for benzodiazepines in older Americans exceed what research suggests is appropriate and safe.”
Benzodiazepines — named for their chemical structure — are among the most commonly prescribed medications in developed countries. They include alprazolam (Xanax), diazepam (Valium), and lorazepam (Ativan).The most common uses of benzodiazepines are to treat anxiety and sleep problems. While effective for both conditions, the medications have risks, especially when used over long periods. Long-term use can lead to dependence and withdrawal symptoms when discontinued. In older people, research has shown that benzodiazepines can impair cognition, mobility, and driving skills, and they increase the risk of falls.
Despite the large number of prescriptions in the United States — 85 million in 2007 — relatively little was known prior to this study about the specifics of benzodiazepine prescribing in the United States relative to other countries.
astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered that black holes don’t have to be nearly so powerful to shut down star formation. By observing the dust and gas at the center of NGC 1266, a nearby lenticular galaxy with a relatively modest central black hole, the astronomers have detected a “perfect storm” of turbulence that is squelching star formation in a region that would otherwise be an ideal star factory.
This turbulence is stirred up by jets from the galaxy’s central black hole slamming into an incredibly dense envelope of gas. This dense region, which may be the result of a recent merger with another smaller galaxy, blocks nearly 98 percent of material propelled by the jets from escaping the galactic center.
“Like an unstoppable force meeting an immovable object, the particles in these jets meet so much resistance when they hit the surrounding dense gas that they are almost completely stopped in their tracks,” said Katherine Alatalo, an astronomer with the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena and lead author on a paper published in the Astrophysical Journal. This energetic collision produces powerful turbulence in the surrounding gas, disrupting the first critical stage of star formation. “So what we see is the most intense suppression of star formation ever observed,” noted Alatalo.