Chlamydia trachomatis is a human pathogen that is the leading cause of bacterial sexually transmitted disease worldwide.

More than 90 million new cases of genital infections occur each year. About 70 percent of women infected with Chlamydia remain asymptomatic and these bacteria can establish chronic infections for months and even years. Even when it causes no symptoms, Chlamydia can damage a woman's reproductive organs but standard antibacterial drugs are proving increasingly ineffective in complete eradication, as Chlamydia goes in to persistent mode, leading to asymptomatic chronic infection.

A student who shows up on time, listens respectfully and appears fully engaged to teachers might still lack emotional and cognitive involvement with the course material, according to survey results

More importantly for educators, the paper in Learning and Instruction suggests that student engagement—essential for success in school—is malleable, and can be improved by promoting a positive school environment. The result may lead to diagnostic tools for recognizing disengagement, as well as strategies for creating a school environment more conducive to student engagement. 

Long hours, no money - medical residents have a hard job and it can wear them down. But topping the list are residents in anesthesiology training programs, reports a surve in the July issue of Anesthesia&Analgesia.

The findings raise concerns that, "In addition to effects on the health of anesthesiology trainees, burnout and depression may also affect patient care and safety," write Dr Gildasio S. de Oliveira, Jr, and colleagues of Northwestern University, Chicago.

Mealybugs only eat plant sap but sap doesn't contain all the essential amino acids the insects need to survive - so mealybugs have developed a symbiotic relationship with two species of bacteria, one living inside the other in a situation unique to known biology, to manufacture the nutrients sap doesn't provide.

The net result: The bacteria get a comfy mealybug home, and the bugs get the nutrition they need to live.

University of Montana microbiologist John McCutcheon describes such mutually beneficial relationships used to solve life's little problems as "almost hilariously complicated. But animal-bacterial relationships are extremely common in nature, and it's my goal in life to help people understand that it's normal."

An assistant professor in the Division of Biology at Kansas State University is projecting that grazing animals such as bison and cattle will get smaller due to global warming in the Great Plains. 

The conclusion came about by comparing bison in cooler, wetter regions with those in warmer, drier regions. For example, the average 7-year-old male bison in South Dakota weighed 1,900 pounds, while an average 7-year-old male bison in Oklahoma -- a warmer region -- weighed 1,300 pounds. The cause: grasses in the southern Great Plains have less protein than grasses in the northern Great Plains because of the warmer climate. 

Nearly 70 percent of Americans take at least one prescription drug and more than 50 percent take two, scholars writing in Mayo Clinic Proceedings say. Antibiotics, antidepressants and painkilling opioids are most commonly prescribed, they found. 20 percent of patients are on five or more prescription medications, according to the findings.