Whether or not humans are the only empathic beings is a debate for anthropologists, because there is no science answer; the ability to experience others' emotions is hard to quantify in a species so it is difficult to measure empathy in any objective way. 

The transmission of a feeling from one individual to another, called 'emotional contagion,' is the most basic form of empathy. Feelings are disclosed by facial expressions (such as sorrow, pain, happiness or tiredness), and these feelings can travel from an "emitting face" to a "receiving face." Upon receipt, the mirroring of facial expressions evokes in the receiver an emotion similar to the emotion experienced by the sender.

Testosterone, a steroid hormone, contributes to aggressive behavior in males, but the neural circuits through which testosterone exerts these effects have not been clear.

Prior studies found that the administration of a single dose of testosterone influenced brain circuit function. Surprisingly, those studies were conducted exclusively in women.

Researchers, led by Dr. Justin Carré, sought to rectify that gender gap by conducting a study of the effects of testosterone on the brain's response to threat cues in healthy men. They focused their attention on brain structures that mediate threat processing and aggressive behavior, including the amygdala, hypothalamus, and periaqueductal gray.

Today the Cornell arxiv features a paper by J. Aguilar Saavedra and F. Jouaquim, titled "A closer look at the possible CMS signal of a new gauge boson". As I read the title I initially felt somewhat lost, as being a CMS member I usually know about the possible new physics signals that my experiment produces, and the fact that we had a possible signal of a new gauge boson had entirely escaped my attention. Hence I downloaded the paper and started reading it, hoping to discover I had discovered something new.

One of the greatest and most dangerous naturalistic fallacies is that if our ancestors used something, it must be as good or even better than modern science.

In An Account of the Foxglove and Some of its Medical Uses, published in 1785, Sir William Withering cautioned readers that extracts from the plant foxglove, also called digitalis, was not a perfect drug. "Time will fix the real value upon this discovery," he wrote.  

Weather extremes have been linked to a recently discovered mechanism: the trapping of giant waves in the atmosphere.

A new data analysis now shows that such wave-trapping events are indeed on the rise.  One reason could be changes in circulation patterns in the atmosphere. By analyzing large sets of global weather data, the researchers found an intriguing connection.  

Rossby Waves: meandering airstreams

It's a trick almost everyone knows: to open a locked door, slide a credit card over the latch.

Scientists at The Scripps Research Institute (TSRI) used a similar strategy when they attempted to disrupt the function of MYC, a cancer regulator thought to be "undruggable." The researchers found that a credit card-like molecule they developed somehow moves in and disrupts the critical interactions between MYC and its binding partner.

MYC is a transcriptional factor, meaning it controls gene expression. When MYC is overexpressed or amplified, the unregulated expression of genes involved in cell proliferation, a key step in cancer growth, follows. MYC is involved in a majority of cancers, including Burkitt's lymphoma, a fast-growing cancer that tends to strike children.

Rangeomorphs were unlike any modern organism, which has made it difficult to determine how they fed, grew or reproduced, and therefore difficult to link them to any particular modern group.

They looked like plants but evidence points to the fact that rangeomorphs were actually some of the earliest animals.

Starting 541 million years ago, the conditions in the oceans changed quickly with the start of the Cambrian Explosion – a period of rapid evolution when most major animal groups first emerge in the fossil record and competition for nutrients increased dramatically.

Researchers have come up with a promising method of treating male infertility; a synthetic version of the sperm-originated protein known as PAWP. PAWP has been shown to be required, they write, and their synthetic version was sufficient to initiate the fertilization process.

According to the Centers for Disease Control and Prevention's 2013 Annual Report on Assisted Reproductive Technologies, only about 37 percent of treatment cycles lead to successful pregnancy. This low success rate may be due to a variety of factors in the male and female including the inability of sperm cell to initiate fertilization and trigger embryo development upon egg entry.