science newsletter: Science News SciGuru.com

Τετάρτη 3 Απριλίου 2013

Science News SciGuru.com

Puzzle of how spiral galaxies get their arms comes into focus
Review: Few Effective, Evidence-Based Interventions to Prevent Posttraumatic Stress Disorder
A new understanding of metallic glass
Pre-existing mineralogy may survive lunar impacts
Diet shown to be critical factor in improving type 2 diabetes after bariatric surgery
The evolutionary consequences of infidelity

Puzzle of how spiral galaxies get their arms comes into focus

Posted: 02 Apr 2013 11:12 AM PDT

As the shapes of galaxies go, the spiral disk — with its characteristic pinwheel profile — is by far the most pedestrian.

Our own Milky Way, astronomers believe, is a spiral. Our solar system and Earth reside somewhere near one of its filamentous, swept-back arms. And nearly 70 percent of the galaxies closest to the Milky Way are spirals, suggesting they have taken the most ordinary of galactic forms in a universe with billions of galaxies.

Review: Few Effective, Evidence-Based Interventions to Prevent Posttraumatic Stress Disorder

Posted: 02 Apr 2013 11:03 AM PDT

Millions of adults are exposed to traumatic events each year. Shortly after exposure many experience symptoms of posttraumatic stress disorder (PTSD) such as flashbacks, emotional numbing and difficulty sleeping.

Despite this high rate of exposure, little is known about the effectiveness of treatments aimed at preventing and relieving posttraumatic stress symptoms that adults may experience after such events, according to researchers at the RTI-UNC Evidence-based Practice Center.

A new understanding of metallic glass

Posted: 02 Apr 2013 10:52 AM PDT

Gelatin sets by forming a solid matrix full of random, liquid-filled pores — much like a saturated sponge. It turns out that a similar process also happens in some metallic glasses, substances whose molecular behavior has now been clarified by new MIT research detailing the “setting” of these metal alloys.

Pre-existing mineralogy may survive lunar impacts

Posted: 02 Apr 2013 10:36 AM PDT

Large impacts on the Moon can form wide craters and turn surface rock liquid. Geophysicists once assumed that liquid rock would be homogenous when it cooled. Now researchers have found evidence that pre-existing mineralogy can survive impact melt.

Despite the unimaginable energy produced during large impacts on the Moon, those impacts may not wipe the mineralogical slate clean, according to new research led by Brown University geoscientists.

Diet shown to be critical factor in improving type 2 diabetes after bariatric surgery

Posted: 02 Apr 2013 10:28 AM PDT

Patients with type 2 diabetes who consume a diet identical to the strict regimen followed after bariatric surgery are just as likely to see a reduction in blood glucose levels as those who undergo surgery, researchers at UT Southwestern Medical Center have found.

The evolutionary consequences of infidelity

Posted: 02 Apr 2013 07:55 AM PDT

In the bird world, male and female blue tits are hard to distinguish for the human observer. However, in the UV-range, visible to birds, the male is much more colourful. A closer look at the monogamous mating system of these birds again reveals that all is not what it seems: in every second nest there are chicks that are not related to the care-giving father. An already mated male can increase the number of his offspring by siring extra-pair offspring in other nests than the one he cares for with his mate.