Dark matter is ill-defined and never detected so how can a group of astronomers say current measurements are off by 50 percent?

Most of the matter in the universe is hidden. It's not stars, it's not planets, it's not dust. No one knows what it is. But it must be something or gravity does not work. That something is the mystery. Using inference, if 4 percent of the universe is matter, and around 25 percent is dark matter (what is the rest? Dark energy, an even more fanciful conjecture) then the 'weight' of  dark matter just in our galaxy is 800,000,000,000 times the mass of the Sun, say a group of Australian astronomers who used a method developed almost 100 years ago for their estimate.

People concerned about human-insecticide exposure have stimulated interest in alternative bed bug control materials, including oil-based pesticides and detergent insecticides.

But how well do they work? Researchers from Rutgers University evaluated the efficacy of nine essential oil-based products and two detergents that are labeled and marketed as 'natural' bed bug control. 

The non-synthetic bed bug pesticides contain ingredients such as geraniol, rosemary oil, mint oil, cinnamon oil, peppermint oil, eugenol, clove oil, lemongrass oil, sodium lauryl sulfate, 2-Phenethyl propionate, potassium sorbate, and sodium chloride, included the following products:

Researchers have uncovered a molecular process in the brain known to control eating that transforms white fat into brown fat, and that impacts how much energy we burn and how much weight we can lose.  

Oxytocin, called the "love hormone" because it has been linked to social behaviors like cuddling, maternal care and pair bonding, is also necessary for female social interest during estrus.

A study Cell Press found oxytocin-responsive brain cells that are necessary for female social interest in male mice during estrus, the sexually receptive phase of their cycle. These neurons, found in the prefrontal cortex, may play a role in other oxytocin-related social behaviors such as intimacy, love, and mother-child bonding. 

A new paper from the International Osteoporosis Foundation (IOF) says that one-third of all hip fractures worldwide occur in men, with mortality rates as high as 37% in the first year following fracture.

This makes men twice as likely as women to die after a hip fracture. Osteoporosis experts warn that as men often remain undiagnosed and untreated, millions are left vulnerable to early death and disability, irrespective of fracture type. 

When a sturdy material becomes soft and spongy, it's been damaged in some way. But when it comes to complex fluids and biological cells, things may be different.

By looking at the microscopic building blocks – known as "filaments" – of biopolymer networks, researchers from Forschungszentrum Jülich, Germany and the FOM Institute AMOLF in the Netherlands, revealed (Nature Communications DOI: 10.1038/ncomms5060)  that such materials soften by undergoing a transition from an entangled spaghetti of filaments to aligned layers of bow-shaped filaments that slide past each other.