Arp 142 looks like the profile of a celestial bird but its imagery shouldn't overlook the fact that close encounters between galaxies are a messy business.

The interacting galaxy duo Arp 142 contains the disturbed, star-forming spiral galaxy NGC 2936, along with its elliptical companion, NGC 2937.

Once part of a flat, spiral disk, the orbits of the galaxy's stars have become scrambled due to gravitational tidal interactions with the other galaxy. This warps the galaxy's orderly spiral, and interstellar gas is strewn out into giant tails like stretched taffy.

The Red Queen hypothesis, a popular idea in evolution named after Lewis Carroll's character who in "Through the Looking Glass" described her country as a place where "it takes all the running you can do, to keep in the same place", recently got studied by a group of researchers who were thinking beyond the death of individual species -  they examined how the lack of new emerging species also contributes to extinction. 

Environmental brochures highlight fears about groups of animals, such as frogs or the "big cats," going extinct. But in science that is only part of the story.

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."