How to keep track of mouse urine
Eight hours is a long time without a trip to the bathroom when awake, yet most of us can sleep through the night without peeing. And no, it’s not just because you (presumably) stop drinking coffee in your sleep: even when food and drink are factored out, you both make less urine and have better bladder capacity during the night. As with most behaviors that change from day to night, it does indeed have everything to do with the circadian rhythm.
In a new study published in Nature Communications, researchers compared normal mice with mice whose circadian rhythms were disrupted by genetic mutations. To keep track of mice urination over time, they used a rather charming contraption that slowly unspooled urine paper under the cages (see image). Urine spots on the paper were counted up and, sure enough, urination in the normal mice showed 24-hour patterns while the mutant mice did not.
How you doin’?
After thousands of years living in our homes, cats and dogs have gotten pretty good at tuning into human social cues—as good as human babies anyways.
Dogs, with their adorable puppy faces, are easily swayed by the actions of humans. A new study in PLoS ONE shows that dogs will prefer a plate of food preferred by a person, even if that plate has less food on it. Cats, on the other hand, have an especially annoying “solicitation” purr that they deploy when they want something from their owners, much like (though quieter than) a hungry baby that will not stop screaming. Pet owners who fancy themselves parents may actually be onto something.
The things we do for science.
Researchers who study mosquitoes and other blood-sucking insects sometimes use themselves as skeeter chow. In some cases, it’s because certain species of mosquitoes seem to prefer human blood to animal blood. In others, though, it’s a cheap, convenient alternative to keeping animals around for the insects to feed on or buying blood. And as it turns out, once you’ve been bitten a certain number of times you develop a tolerance to mosquito saliva.
Entomologist Steve Schutz, seen above paging through a magazine while the bloodsuckers go to work on his arm, feeds his mosquito colony once a week. He has welts for about an hour, but after that the bites fade, occasionally leaving a few red spots. That’s good, because at 300 bites a week, he averages about 15,000 a year. That’s dedication.
CT scan of whale head; fat in yellow, ear bones in magenta.
For us landlubbers, jiggling fat may just be an unsightly presence. For whales, jiggling clumps of fat in their jaws may pick up sound waves underwater, helping them communicate over long distances in the sea. We knew that dolphins and porpoises have “ear fats,” but baleen whales have not been as well-studied for one simple reason: their heads are just too big to fit into a scanner.
A new study looks at minke whales, a genus of balleen whales that top out at only seven meters long. (Tiny compared to 30-meter blue whales.) Scientists put six frozen whale heads, salvaged from beached animals, in CT and MRI scanners to analyze the soft tissues. Some of the heads were still too big, so the lower jaw had to be removed or excess flesh trimmed away. The scans and subsequent dissections showed a glob of fat sitting right next to the ear bones. While the anatomical evidence is compelling, the researchers admit they still have to show how exactly the fat works to help in hearing.
During a snow storm last year, several cows managed to wander into a ranger cabin where they have stayed ever since. Alas, the cows have not been playing house—they died in the cabin, and there they remain, dead and frozen. Rangers at Conundrum Hot Springs are now faced with removing several tons of dead, frozen cow from the remote mountain spot. If not, the slowly decomposing bodies could attract predators and cause contamination.
So here’s the dynamite idea they’ve proposed: blow ’em up to smithereens and radically speed up the decomposition process. Lucky for the rangers, the USDA happens to have a protocol detailing every step of this process—including diagrams of where to place the explosives.
Because this diagram is optimized for a horse, it includes species-specific pro tips like, “Horseshoes should be removed to minimize dangerous flying debris.” The full protocol also includes a second, more complicated diagram of where to pack explosives on a frozen animal such as these cows. It ends with this note: “Carcasses that have been partially obliterated will generally not show any trace of existence the next day.” Good to know.
[via Improbable Research]
My, what, uh, nice hair you have…
Among the mutant lab mice that scientists have dreamed up, there’s a particularly funny-looking nude mouse. Now scientists have managed to make it look even more ridiculous by adding just one small tuft of black hair on its back.
Getting the hair follicles to sprout was no small feat of bioengineering. As reported in a new paper in Nature Communications, researchers took stem cells from bald mice as well as men and implanted them in the skin of the nude mice. A plastic sheath guided the growing hair through layers of the skin, and voila. The individual hairs could also stand up on their ends—just like how your body hair stands up when you’re cold–which means the bioengineered follicles even connected to the small muscle that control piloerection.
And if you ever wanted to a naked, red-eyed mouse with one tuft of black hair to stare straight into your soul, do not miss the video below.
And unicorns, too.
Well, no. Just the dinosaurs. But isn’t that enough?
Each of the quarters, which will retail for $29.99, will feature an image of a Pachyrhinosaurus lakustai, a dinosaur discovered in Alberta. But take it into the closet under the stairs or wherever your favored glow-in-the-dark viewing site is, and the creature’s skeleton glows.
This is, according to TIME’s Moneyland, the Canadian government’s latest scheme to help shrink the deficit. We’re not hopeful, though—how many dino-loving 6-year-olds have $29.99 to spare?
Image courtesy of Canadian Mint
Did you know I can eat and digest bone? Plenty of calcium.
After painstakingly identifying all the animal hairs in hyena poop, scientists have determined that Lent forces spotted hyenas in Ethiopia to change their diets too. No, Ethiopians have not managed to convert hyenas—they just deprive them of butcher scraps.
In 2004, a street in Taiwan got showered in whale guts. The putrefying whale was on route to a necropsy when pent-up gas blew a hole in its body and entrails spewed onto unfortunate passersby. One hundred to 200 million years earlier, an ichthyosaur—a dolphin-looking marine reptile contemporary to dinosaurs—died and became a fossil. Since embryos were scattered around the ichthyosaur mother’s body, some paleontologists believed the decaying animal had met an end as explosive as the whale’s.
The exploding-carcass theory has been used to explain why so many ichthyosaur fossils have been found with embryos ejected or bones oddly scattered. But as with old bones, evidence is frustratingly thin: the theory was mostly based on exploding whales as proof of principal. Scientists who want to test this hypothesis today don’t have any ichthyosaur carcasses at their disposal…but there are a lot of humans around now, many of them dead. A new study measuring gas pressure in 100 bloating human carcasses found the pressure (0.035 bar) to be nowhere near high enough to cause an explosion underwater (more than 5 to 15 bar).