People 60 or older, especially minorities and women, have a lower risk of stroke if the top number (systolic) in their blood pressure is below 140 millimeters of mercury (mm Hg), according to a study presented at the American Stroke Association's International Stroke Conference 2015.

A report published in JAMA in 2014, advised doctors to aim for blood pressure readings of less than 150/90 mm Hg when treating patients 60 or older who do not have diabetes or chronic kidney disease. That raised the standard for systolic blood pressure, by 10 points from previous guidance, stirring controversy among healthcare providers, agencies and professional groups.

Some of the coldest air of the 2014-2015 winter season is settling over the eastern two-thirds of the U.S., an Arctic air mass that brought wind chills from below zero to the single numbers from the Midwest to the Mid-Atlantic.

It is certainly cold on the surface, but infrared NASA satellite imagery revealed even colder temperatures in cloud tops associated with the air mass.

Evolution starts species off on different paths and even if they arrived in one spot from common descent in the past, they can't reproduce. So in modern times an elephant is not hybridizing with a manatee, or a human with a lemur. Tree frogs...well, yes, but who can explain tree frogs? That did happen, two species were able to interbreed after 34 million years, and sunfish who hybridized after nearly 40 million years.

There may be a new explanation for why fad diets tend to cluster in pockets - and it may help companies spend their marketing money a little smarter also.

A 10-year retrospective study of 383 children is the first to examine the prevalence of positive drug screens in pediatric patients undergoing  multiple sleep latency test (MSLT) for narcolepsy.

The results in Journal of Clinical Sleep Medicine showed that 43 percent of children with urine drug screens positive for marijuana actually had test results consistent with narcolepsy or abnormal REM sleep patterns. No child younger than 13 years of age had a positive urine drug screen. The data showed that males were more likely to have a positive urine drug screen and MSLT findings consistent with narcolepsy.  

Suppose we we tell you everything quantum mechanics can tell you about a quantum particle; what do you really know? Unfortunately, you still cannot predict with certainty the outcome of a simple experiment to measure its state. All quantum mechanics can offer are statistical probabilities for possible results.

This indeterminacy is not a defect, it's a defining feature of its undefined nature. The particle's state is not merely unknown, but truly undefined before it is measured. The act of measurement itself forces the particle to collapse to a definite state.