The thyroid gland has an important role in regulating the body's metabolism, but researchers say it can also influence mental health. Past research found links between an increased risk of depression and both over- and under-active thyroid glands. Now, a new study in the Journal of Clinical Endocrinology  &  Metabolism has found an association between depression and thyroid activity variations...even within the normal range.

 Heart disease is the world's leading cause of death, but recent advances in science and medicine have improved the chances of surviving a heart attack. In the United States alone, nearly one million people have survived an attack, but are living with heart failure—a chronic condition in which the heart, having lost muscle during the attack, does not beat at full capacity.

Scientists have been look at cellular reprogramming as a way to regenerate this damaged heart muscle. And it works. Scientists can transform skin cells into cells that closely resemble beating heart cells but it's complicated and the transformation is often incomplete. 

If you want to turn down the emotional intensity before making an important decision, turn down the lights, say Alison Jing Xu, assistant professor of management at the University of Toronto Scarborough, and Aparna Labroo of Northwestern University.

Researchers have created an adult stem cell based method for restoring strength to damaged skeletal muscles in the elderly. 

Skeletal muscles are some of the most important muscles in the body, supporting functions such as sitting, standing, blinking and swallowing. In aging individuals, the function of these muscles significantly decreases.   People lose fifteen percent of muscle mass every single year after the age of 75, a trend that is irreversible. 

Through tracing the signaling pathways of the cells, the researchers determined that during aging, a subpopulation of stem cells begin to express a modification of a protein that inhibits their ability to grow and make new stem cells. 

In the 'sometimes what you don't find can be important too' department, a new high-accuracy calibration of the LUX (Large Underground Xenon) dark matter detector's sensitivity to ultra-low energy events strongly confirms the result that it did not find low-mass dark matter particles last summer during its initial run.

Survey results related to how men approach old age found that happiness remains relatively stable for some 80 percent of the population, but perceptions of unhappiness – or dealing with "hassles" – tends to get worse once you are about 65-70 years old.

The reasons vary, researchers say, but may be because of health issues, cognitive decline or the loss of a spouse or friends.