More than half of all Medicaid enrollees use hospital emergency departments to receive care for conditions that could be treated at a primary care clinic. Why? Some of it may be urgency, and it may be cheaper for them, since they won't miss work. But it isn't cheaper for the rest of society and as the Affordable Care Act ballooned the use of Medicaid, the costs have gone up as well.

"From a patient's perspective, having all imaging and laboratory studies done in one place is likely more cost effective than going to a [primary care provider] clinic and having gone elsewhere to get further testing," writes Roberta Capp, assistant professor of emergency medicine at the University of Colorado School of Medicine on the Anschutz Medical Campus in the journal Medical Care.

Some cases of male infertility are due to mutations in the maternal X chromosome that prevent development of viable sperm, according to a study led by researchers at the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute (MWRI). The study was published online today in the New England Journal of Medicine.

Scientists have made an important step towards understanding how volcanic eruptions happen, after identifying a previously unrecognised potential trigger.

An international team of researchers from the University of Liverpool, Monash University and the University of Newcastle (Australia) think their findings could lead to new ways of interpreting signs of volcanic unrest measured by satellites and surface observations.

Dr Janine Kavanagh, from the University of Liverpool's School of Environmental Sciences and lead author of the research paper, said: "Understanding the triggers for volcanic eruptions is vital for forecasting efforts, hazard assessment and risk mitigation.

Serengeti  means means “endless plains” in the Maasai language, but Tanzania's Serengeti National Park, which extends into Kenya towards the Mau Forest, the largest virgin montane forests of Africa, faces huge pressures from population growth.

It's easy for western elites who already have homes and educations to lament encroachment of nature by humans living in remote areas without either, but the real world needs more practical solutions. A new EU program is attempting to help.

NaSt1, about 3,000 light years away, was discovered a few decades ago and identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our Sun.

Wolf-Rayet stars lose their hydrogen-filled outer layers quickly, exposing a super-hot and extremely bright core where helium is fusing into heavier elements. Typically, Wolf-Rayet stars have two outward flowing lobes of material, but in this case, the Hubble observations revealed a pancake-shaped disk of gas encircling the star. This vast disk is more than 3 billion billion kilometers wide. It seems to have formed in the last few thousand years from an unseen companion star that snacked on its outer atmosphere.

The star is so weird that astronomers have nicknamed it “Nasty 1”.

When you mention rich ecosystems that are vital for life on Earth, people tend to think of rainforests, but ocean plankton are actually just as crucial. The microscopic beings that drift on the upper layer of the oceans are globally referred to as "plankton"; together they produce half of our oxygen, act as carbon sinks, influence our weather, and serve as the base of the ocean food web that sustains the larger fish and marine mammals that we depend upon or draw delight from.

"Beyond the cutting-edge science that was developed thanks to our collaborative work with the Tara Expéditions Foundation, this adventure is also about showing people all over the world how important the ocean is for our own well-being," says Eric Karsenti, director of Tara Oceans, from EMBL and CNRS.