News good and bad

Public health researchers found that seniors who participated for two years in a public school mentoring program did not suffer the shrinkage of the brain's memory centers that is characteristic of age. They also showed improvement on memory tests. Click here to learn more.

A study of people who survived a critical illness and were treated in an intensive care unit found that one in four experienced post-traumatic stress disorder. Researchers noted that this was a PTSD rate comparable to that suffered by combat veterans and rape victims. Existing psychological problems, heavy sedation, and frightening ICU memories appear to increase the risk. Click here to learn more.

Health care studies of U.S. patient outcomes rely on good data from clinical registries. But investigators who assessed 153 American registries found that most had failed to accurately measure and track patient outcomes. The study determined that most registries were underdeveloped and underfunded, and were not using sound methodology. Click here to learn more.

Elsewhere at Hopkins …

HOLY WING HAIRS, BATMAN

Scientists studying the flight of bats discovered that the remarkably agile fliers feel their way through the air. Their wings are equipped with touch sensors so sensitive they can detect small changes in airflow. Many of the sensors are located at the base of the fine hairs that cover a bat's wings. Click here to learn more.

TWITTER IS SULKING—BUY EARLY

Public sentiment expressed on Twitter about initial public stock offerings reliably predicted first-day performance of the IPOs, though in a paradoxical way. Business researchers found that in the three days prior to an IPO, optimism on Twitter tended to be followed by an opening-day slump in the price of shares. The paradox held true for pessimistic Twitter sentiment: A gloomy outlook tended to be followed by an increase in share prices on the first day of the offering. Click here to learn more.

HYPERACTIVE EATING

A study of children with attention deficit hyperactivity disorder found that they are more likely to suffer from an eating disorder akin to binge eating, known as loss of control eating syndrome. The connection is not yet clear, but experts suspect a link between impulsivity (an aspect of ADHD) and the loss of control over eating. Click here to learn more.

BLAME AGRICULTURE

A seven-year study found that human bones have become less dense over the last 33,000 years because of the development of agriculture and the corresponding reduction in mobility. As humans began settling on farms and wandering less, lower-body bone density decreased, and humans became more susceptible to osteoporosis. Click here to learn more.

TROUBLE BREATHING

Scientists studying lung diseases such as emphysema and pulmonary fibrosis discovered that defective telomeres (the "caps" on the ends of chromosomes) result in premature aging of stem cells in the lungs. These senescent stem cells in turn trigger the immune system, resulting in the inflammation central to lung diseases. Click here to learn more.

Since 2004, levels of radon in houses in Pennsylvania have been increasing. Public health investigators found that this increase correlates with the advent of extraction of natural gas in the state by fracking. They also found that radon levels correlated with the level of drilling activity in each county—the more drilling, the more radon, which has been implicated in lung cancer. Click here to learn more.

THE SKINNY ON DIETS

A review of 4,200 studies of commercial weight-loss programs found that of 32 major diet programs marketed nationwide, only 11 have been rigorously studied in randomized controlled trials. Of those 11, only two—Weight Watchers and Jenny Craig—had gold-standard data demonstrating that participants, on average, lost more weight than people dieting on their own without the programs. Click here to learn more.