Monday Science Links

This week's heaping helping of sciency goodness:

• Jake at Pure Pedantry on Natasha Richards and epidural hematomas: Unfortunately, epidural hematomas can have a much more insidious presentation -- which explains why Natasha Richardson was walking around after she got one. Epidural hematomas are usually caused by trauma. Often, you get a blow to the side of your head and rupture an artery. (The middle meningeal artery is quite common.) However, rather that immediately causing a headache or bursting through the dura, the blood pools outside the dura pressing on the brain.


• Carl Zimmer at The Loom blogs on bats: life in motion, with video: When the evenings get particularly thick with mosquitoes where I live, I sometimes sit out in the yard with my daughters and look up at the fading sky. Before too long, a single bat will usually flit out of the nearby trees and start flying circles around the house, scooping up bugs along the way. We can barely make out the bat’s wings as it takes its laps, a flicker of membranes. And so it was a revelation to spend some time earlier this week with two Brown University biologists, Dan Riskin and Sharon Swartz, watching slow-motion movies of bats in flight. There’s a lot going on up there. Bats evolved about 50 million years ago from squirrel-like ancestors. They probably made their first forays into the air as gliders. Like living gliders, they used flaps of skin to increase their surface area, letting them glide further. Their hands evolved long spindly fingers that were joined by membranes. Some early bat fossils suggest that they may have shifted from gliding to alternating between gliding and bursts of fluttering. Eventually bats evolved sustained powered flight. Bats evolved a way to take advantage of the same laws of physics birds use to fly. And many scientists who have studied bat flight in the past have basically treated bats like leathery birds. Yet there’s no reason to assume that this should be so.


• Mo at Neurophilosophy blogs on body integrity and identity disorder: If someone told you that they wanted to have a perfectly good leg amputated, or that they have three arms, when they clearly do not, you would probably be inclined to think that they are mentally disturbed. Psychiatrists, too, considered such conditions to be psychological in origin. Voluntary amputation, for example, was regarded as a fetish, perhaps arising because an amputee's stump resembles a phallus, whereas imaginary extra limbs were likely to be dismissed as the products of delusions or hallucinations. These bizarre conditions - body integrity and identity disorder (BIID) and supernumerary phantom limb - are now widely believed to have a neurological basis. Two forthcoming studies confirm this, by providing strong evidence that both conditions occur as a result of abnormal activity in a part of the brain which is known to be involved in constructing a mental representation of the body, or body image.


• Darren at Tetrapod Zoology gives us thunder beasts in pictures and thunder beasts of New York: No time for a proper article: all I've done here is to take screen-shots of various powerpoint slides (from a perissodactyl lecture I give), and throw in a few words where appropriate...and This incredible skeleton, easily the best known brontothere specimen in the world, is AMNH 518, collected from White River, South Dakota, in 1892. You can gauge its size from the adjacent person...


• Jess at Magma Cum Laude is at a volcano (though not Redoubt): Santiaguito is a strange place. The first of the lava domes in the complex, Caliente (the one erupting in the first photo, and the farthest to the right in the one above) began extruding from the 1902 eruption crater in Santa Maria in 1922. By 1929, the year that a 3 million cubic meter collapse and pyroclastic surge occurred, the dome had grown to about half a cubic kilometer in size. In the next 80 or so years, the other three domes - La Mitad, El Monje, and El Brujo - formed as the active vent migrated westward. Then, after a brief period when both Caliente and El Brujo were active, everything shifted back to Caliente. Currently, Caliente is looking more and more like a mini-stratovolcano - the old rubbly dome has long since been covered over by talus slopes and lava flows. At the summit, however, is a very strange situation.
  

Enjoy!