One day a few years ago, while working on wasps in a rainforest in Costa Rica, entomologist Kevin J. Loope, a postdoctoral researcher at the University of California, Riverside, began reading about the enigmatic matricidal behavior of some social insects. In most social insects, such as bees, ants and wasps, the workers, which are all female, work their whole lives to help the queen produce new offspring. Yet, in the literature Loope found anecdotal reports of workers killing their queen, presenting a fascinating evolutionary puzzle.

Asthma has become the most common chronic disease in children, and that plus a corresponding increase in modern helicoptering parenting one of the reasons there are so many emergency department visits for asthma in the US.

A new study presented at the American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting has determined that the probability of future acute care visits increased from 30 percent with one historical acute care visit to 87 percent with more than five acute care visits, based on records for more than 10,000 children seen for asthma in a three-year period. It focused on acute care visits which included emergency departments, urgent care centers and inpatient admissions at hospitals. 

The 2015 Antarctic ozone hole area was larger and formed later than in recent years, accorrding to a new paper. On Oct. 2, 2015, the ozone hole expanded to its peak of 10.9 million square miles, an area larger than the continent of North America.

Throughout October, the hole remained large and set many area daily records. Unusually cold temperature and weak dynamics in the Antarctic stratosphere this year resulted in this larger ozone hole.

In comparison, last year the ozone hole peaked at 24.1 million square kilometers (9.3 million square miles) on Sept. 11, 2014. Compared to the 1991-2014 period, the 2015 ozone hole average area was the fourth largest.

Just how bad was the bite of Tyrannosaurus rex? Pretty bad, because the feeding style and dietary preferences of dinosaurs was closely linked to how wide they could open their jaws and T. rex could open quite wide.

Using digital models and computer analyses, Dr. Stephan Lautenschlager from the University of Bristol  studied the muscle strain during jaw opening of three different theropod dinosaurs with different dietary habits. Theropods (from the Greek for "beast-footed") were a diverse group of two-legged dinosaurs that included the largest carnivores ever to walk the Earth.  

Substance abuse treatments that target drug and alcohol addiction are not frequently being used to also wean adolescents from tobacco, a study finds. There are even proposals to curb harm reduction and smoking cessation techniques at Food and Drug Administration (the American Council on Science and Health will be at the White House talking about smoking cessation regulations in a few weeks), which would keep young people addicted to cancer-causing smoke. The reason is likely because cigarette smoking doesn't carry the stigma that alcohol and other erious drugs do, according to the study's lead author, Jessica Muilenburg, an associate professor at University of Georgia's College of Public Health. 

The HIV epidemic among gay men in the Netherlands isn't going to decline as long as large, persistent, self-sustaining, and, in many cases, growing sub-epidemics shifting towards new generations of gay men, according to a new paper in PLOS Medicine by Daniela Bezemer from HIV Monitoring Foundation, Amsterdam, the Netherlands, and Anne Cori from Imperial College London, UK, and colleagues.