Three of my favorite tragic anime protagonists:
Madoka Kaname // Shinji Ikari // Kaneki Ken
Uh, so I switched over to SMC, but the south park subtitles stayed….
In case anyone was wondering, it did, in fact, continue.
Racket-tailed Roller (Coracias spatulatus)
Distribution: southern Africa
IUCN Status: Least Concern
[Image: A flock of Hatzegopteryx. One paces along on all fours, another rockets into flight by pushing off with its strong forelimbs, and the rest soar above them.]
Pterosaur Myths Busted (V3)
Pterosaurs are a staple of movies featuring prehistoric animals—yet most media depictions of the poor beasts remain woefully stuck in the 19th century. Real pterosaurs were just about nothing like the sluggish, flimsy-winged gliders that populated our childhood picture books and movies. Here we take a look at how some common misconceptions about them stack up against the facts.
Misconception: “Pterodactyl” and “pterosaur” mean the same thing.
Fact: “Pterosaur” applies to the entire group, but “pterodactyl” is only correct when you’re referring to, well, pterodactyloids.
In general, pterodactyls had proportionally shorter tails, longer necks, bigger heads, and longer hand bones than non-pterodactyls. Compare these skeletal drawings of Rhamphorhynchus (a non-pterodactyl) and Pteranodon (the ’dactyl of Jurassic Park fame).
M: Pterosaurs were dinosaurs.
M: Pterosaurs were the ancestors of birds.
F: Like their cousins Velociraptor and T. rex, birds are a type of theropod dinosaur. Pterosaurs left no living descendants.
M: Pterosaurs had scaly / leathery / bald skin.
F: Though the pads of their feet were scaly, most of a pterosaur’s body was covered in hairlike filaments called pycnofibers. Pterosaurs of the primitive family Anurognathidae, such as the one shown below, seem to have been fluffed up from snout to tail with pycnofibers.
M: Pterosaurs were “cold-blooded.”
F: Nope. With no body heat to insulate there wouldn’t be much point to pycnofibers.
M: Pterosaurs could pick things up with their feet.
F: Their feet were much better suited to walking than grasping. Like humans, they had plantigrade feet—in other words, the entire sole of the foot contacted the ground as they walked.
M: Grounded pterosaurs walked on their hind legs / could only crawl around on their bellies.
F: Pterosaurs usually walked on all fours, and many were quite adept at ground locomotion to boot, especially the pterodactyls. Some, such as the dsungaripteroids, may even have been capable of galloping. The three in the illustration below are shown badgering an azhdarchid for its kill.
M: All pterosaurs had teeth / were toothless.
F: Pterosaurs had all kinds of dental arrangements, from completely toothless to jaws positively bristling with the things—just look at Pterodaustro below. (Pteranodon was toothless, by the way; its name even means “toothless wing.”)
M: Females of crested species had large head crests like the males.
F: Head crests were probably sexually dimorphic, with males usually having much larger, more elaborate head decoration, as demonstrated by these two Darwinopterus.
M: Pterosaur wing membranes were leathery, flimsy and prone to tearing.
F: Pterosaur wings were supple, complex, multilayered structures. They were reinforced with closely-packed fibers called aktinofibrils.
M: Each wing was supported by several fingers like a bat’s.
F: Only the hugely elongated fourth finger supported the wing; the other three fingers were much smaller. See here for a diagram of the pterosaur wing.
M: Pterosaurs had sharply-pointed wing tips.
F: Such a wing shape would have made flight difficult. Here’s our anurognathid friend again, showing off its nice rounded wing tips for you.
M: Some pterosaurs were too big / heavy to fly.
F: Even the largest pterosaurs were probably capable of powered flight.
M: Pterosaurs could only take off by falling from a cliff / tree / [insert high starting point here].
F: They could launch into flight under their own power using all four limbs, a strategy also known in some modern bats. This is called “quadrupedal launch” (or just “quad launch”). See this video for a pterosaur quad launch demonstration.
M: All pterosaurs were ocean-going fish hunters.
F: They occupied a variety of niches, and many lived inland.
M: Pterosaurs cared for their hatchlings in much the same way as modern birds.
F: Other than protecting them during the hatching process, pterosaur parents might not have had much to do with their offspring (called “flaplings”) since they could probably fly almost immediately after birth.
Recent findings reveal that at least some pterosaurs, such as Hamipterus, were social and may have built their nests together in huge colonies.
M: Pterosaurs went extinct because they were outcompeted by birds.
F: The evidence for this idea is weak at best.
M: Live pterosaur sightings prove that pterosaurs never really went extinct.
F: This idea relies on scant evidence as well.
If you have anything more than a passing interest in pterosaurs, you really should pick up a copy of paleontologist Mark Witton’s book on them. Pterosaur.net is another useful resource of information about these fascinating, ridiculous creatures.
Sources to avoid include David Peters’ Pterosaur Heresies and ReptileEvolution.com. While these sites seem professional on the surface and feature loads of attractive artwork, scientists have been unable to replicate the results of Peters’ research, and repeatable results are a hallmark of good science. Read more about Peters here (PDF), here and here.
Some Like It Hot: A Look at Capsaiscin
If you’ve ever eaten a chili pepper— either because of a dare or by your own volition— you have no doubt come across the painful burning sensation that comes soon after. But what causes this pain? And why does it exist in the first place? Before we look at chemistry, we have to look at biology— specifically, evolution.
Capsaicin is found naturally in chili peppers, in varying quantities. To truly understand its purpose, we have to look at where it’s located. The amounts of capsaicin vary throughout the plant, but the highest concentrations are found in the placental tissues surrounding the seeds of the plant. This makes sense evolutionarily, as the seeds are the future generations of these peppers. It makes sense that the plant would use whatever means are most effective to protect its progeny. Capsaicin, with its burning, itching, stinging side effects, acts as a perfect deterrent to possible predators looking for a tasty meal.
Now that we know why capsaicin exists - why does it burn? This is where the chemistry comes in. The burning, painful sensation attributed to capsaicin results from chemical interactions with sensory neurons. When introduced to the body, capsaicin binds to a specific receptor called the transient receptor potential cation channel subfamily V member 1 (TrpV1) or, more simply, the vanilloid receptor subtype 1. This receptor is a subtype of receptors that are present in peripheral sensory neurons. The vanilloid receptor 1 is usually reserved for detecting heat or physical abrasion. When heat is applied to the surface of the skin this TRPV1 ion channel opens, allowing cations (positively charged ions) into the cell. This inflow of cations activates the sensory neuron, which sends signals to the brain that there is a painful stimulus present. Capsaicin has a binding site on the receptor, and opens the cation channel just like if heat were applied. This results in a signal to be brain to alert you of a potential threat and produces a burning sensation where the capsaicin was introduced, but without an actual burn.
Interestingly, while the receptor works this way in most mammals, it is not activated by capsaicin in birds; therefore, birds are the largest distributors of capsaicin seeds in the natural environment.
This has just been a brief overview of some of the chemistry of capsaicin, but hopefully next time you bite into a jalapeno, you’ll take a moment to appreciate the science that’s occurring before you gulp down your milk!
Pingle SC, et al. Capsaicin receptor: TRPV1 a promuscious TRP channel. Handbook of experimental pharmacology. 2007.(179):155-71.
Tewksbury JJ. et al. Ecology of a spice: Capsaicin in wild chilies mediates seed retention, dispersal and germination. Ecology. 2008. (89):107-117.
Submitted by thatoneguywithoutamustache
Edited by Ashlee R.
3-D printing has been gaining more and more traction in the medical field. It’s versatility and precision allows for some amazing work to be done.
Here is an example of a vertebral implant done in China. The idea is simple, but the execution was elegantly done. They used titanium that is already used safely for the main component of the vertebrae, and used a porous material that allows for fusion with the natural cell growth in the body.
This brings up an interesting point about the development and implementation of new technology… In foreign countries we are seeing the rise of these 3-D printed implants being used in the clinics, but because of the strict restrictions in the U.S. most 3-D printing technology is still being used for imaging and modeling purposes. Of course this allows for increase in safety and ensures optimal integration of the technology, but creates too much barriers (incl financial, accessibility) for patients…
I know we have readers pitching in from all over the world, what are your thoughts on regulations at your country? Do you feel like more regulations are needed, or maybe less?
A video posted Oct. 7 captured the moment when Hester’s eye surgeon, Dr. Paul Hahn, turned on the device’s electronic stimulator for the first time since he implanted the sensor last month.