An analysis of about 1,300 peer-reviewed research articles found that few studies included men and women equally, less than one-third performed data analysis by sex, and there was wide variation in inclusion and matching of the sexes among the specialties and the journals reviewed, according to a paper JAMA Surgery.

Males and females can have different postoperative outcomes, complication rates, and readmission rates, so it is important to know if sex bias is pervasive in surgery. Adequately controlling for sex as a variable with inclusion, data reporting, and data analysis is important because data derived from clinical research are the foundation for evidence-based medicine.

The number of microbes in, on, and around the planet - on the order of a nonillion, or 10^³⁰ - is estimated to outnumber the stars in the Milky Way. Microbes are known to play crucial roles in regulating carbon fixation, as well as maintaining global cycles involving nitrogen, sulfur, and phosphorus and other nutrients, but the majority of them remain uncultured and unknown. The U.S. Department of Energy (DOE) is targeting this "microbial dark matter" to better understand the planet's microbial diversity and glean from nature lessons that can be applied toward energy and environmental challenges.

Few things are as interesting to a male mouse as the scent of a female. Pheromones released by females draw the attention of male mice and trigger courtship and mating behavior.

Now, researchers at Washington University School of Medicine in St. Louis have found a specific kind of neuron only in male mice that detects a pheromone in female urine. But the sex difference is not hard-wired. By manipulating the mice's living conditions and exposing male mice to female scents for long periods of time, the scientists showed that males lost these neurons and their interest in courting females.

The study, published Aug. 17 in Neuron, describes how neurons in the nose adapt to experience, and helps explain differences among individuals and between the sexes.

One year into the National Institutes of Health's Precision Medicine Initiative (PMI), the massive project could still benefit from incorporating experimental studies of animal models of human disease, according to Kent Lloyd and colleagues in this Editorial. The PMI hopes to prompt a new era of individualized medicine, where a person's own genetic profile along with personal environmental exposures and behaviors can be used to target therapies more effectively. The massive amounts of genetic and molecular data accrued from animal models to date, along with the procedures for curating, integrating, and mapping these data, could prove useful to researchers working on the PMI, Lloyd and colleagues write.

A new study in Neurology associates calcium supplements with an increased risk of dementia in older women who have had a stroke or other signs of cerebrovascular disease. 
Calcium from food affects the body differently than calcium from supplements and is safe or even protective against vascular problems. 

Cerebrovascular disease is a group of disorders that affect blood flow in the brain. These diseases, including stroke, are the fifth leading cause of death in the United States and increase the risk of developing dementia.

CRISPR-Cas9 is the go-to technique for knocking out genes in human cell lines to discover what the genes do, but the efficiency with which it disables genes can vary immensely.

University of California, Berkeley researchers have now found a way to boost the efficiency with which CRISPR-Cas9 cuts and disables genes up to fivefold, in most types of human cells, making it easler to create and study knockout cell lines and, potentially, disable a mutant gene as a form of human therapy.

Scientists are constantly discovering new genes or the proteins they code for, but it's much harder to figure out their role in the body or in disease. Key to discovering this role is disabling the gene to see what happens when it's removed.