'Lucid' dreamers are people who claim they are aware that they are dreaming and can deliberately control their actions in dreams. When people dream that they are performing a particular action, a portion of the brain involved in the planning and execution of movement lights up with activity. 

This learned skill presents an opportunity for researchers who are studying the neural underpinnings of our dreams and their findings in Current Biology, made by scanning the brains of lucid dreamers while they slept, give us a glimpse into non-waking consciousness and perhaps create a waypoint toward true "dream reading." 

Higher levels of testosterone have been associated with reduced lean muscle mass loss in older men, especially in those who were losing weight. In thoese men, higher testosterone levels were also associated with less loss of lower body strength.

Loss of muscle mass and strength contribute to frailty and are associated with falls, mobility limitations and fractures. Men also lose more muscle mass and strength than women as they age, suggesting that sex steroids, and testosterone in particular, may contribute to body composition and physical function changes.

Experiments have recently supported a longstanding hypothesis that explains how males can survive with only one copy of the X chromosome, a hotly debated topic in science.

Women have two X chromosomes, while men have one X and one Y. The lack of a 'back up' copy of the X chromosome in males contributes to many disorders that have long been observed to occur more often in males, such as hemophilia, Duchene muscular dystrophy and certain types of color blindness. Having only one copy of X and two copies of every other chromosome also creates a more fundamental problem; with any other chromosome, the gene number imbalance resulting from having only one copy would be lethal.

How can males survive with only one X?

In November 2010, the distant dwarf planet Eris passed in front of a faint background star, an event called an occultation. Occultations provide the most accurate, and often the only, way to measure the shape and size of a distant Solar System body like Eris.

Eris was identified as a large object in the outer Solar System in 2005. Its discovery was one of the factors that led to the creation of a new class of objects called dwarf planets by the IAU and the demotion of Pluto from planet to dwarf planet in 2006. Eris is currently three times further from the Sun than Pluto.

Astronomers are reporting that organic compounds of unexpected complexity exist throughout the Universe - which mean they can be made naturally by stars.

Researchers write in Nature that an organic substance commonly found throughout the Universe contains a mixture of aromatic (ring-like) and aliphatic (chain-like) components, compounds so complex that their chemical structures resemble those of coal and petroleum. 

Since coal and oil are remnants of ancient life, this type of organic matter was thought to arise only from living organisms but this new discovery suggests that complex organic compounds can be synthesized in space - even when no life forms are present.

Scientists have discovered more about the intricacies of Natural Killer cells, a unique type of white blood cell important in early immune responses to tumors and viruses.  

Unlike most cells of the immune system that are activated by molecules found on the pathogen or tumor, Natural Killer cells are shut down by a group of proteins found on healthy cells. These de-activating proteins, known as Human Leukocyte Antigens or HLA molecules are absent in many tumors and cells infected with viruses, leaving them open to attack by the Natural Killer cells. 

Natural Killer cells recognize the HLA molecules using an inbuilt surveillance system called "Killer cell immunoglobulin-like receptors" (KIR).