Obsessive-compulsive mice, which were once pulling their hair out from too much grooming, are now sitting pretty. Their cure? A bone marrow transplant. In a study published today in Cell, scientists show an unsuspected link between a psychological disorder and the immune system.
Here’s how they did it:
Step 1 – Finding the Problem
Since excessive cleaning is a behavior, scientists first thought to look for defects in the mouse brain. They noticed that mice with a mutant version of the gene Hoxb8 were the ones cleaning themselves bald. Hoxb8 is important for creating microglia–nervous system repair cells that search for damage in the brain.
Although some microglia start out in the brain, others are born in the bone marrow and move in. Overall, adult mice with faulty Hoxb8 harbored about 15% fewer microglia in the brain than normal. [ScienceNow]
Since many microglia move from bone marrow to brain, the scientists decided to give the compulsive mice, with the mutant Hoxb8 gene, a marrow transplant.
With hurricane season fast approaching, the official forecasts are coming out. And they’re not good. The National Oceanic and Atmospheric Administration estimates that between 14 and 23 storms could reach the severity level of a tropical storm—the point at which they get a name.
Of those, eight to 14 are expected to become hurricanes. From three to seven of these could become major hurricanes, with winds exceeding 111 miles an hour. This compares with a long-term average of 11 named storms per season, with six becoming hurricanes and two becoming major hurricanes [Christian Science Monitor].
The warning signs are alarming even experienced hurricane watchers.
The tropics are even warmer than the toasty waters that spurred the 2005 hurricane season into such dizzying activity, with 28 named storms including Katrina, Rita and Wilma…. “The coming season looks very active based upon the latest data we’ve seen,” said Phil Klotzbach, who along with Colorado State University scientist Bill Gray publishes a widely regarded seasonal forecast. “The tropics are super warm right now” [Houston Chronicle].
The bones of our ancestors do not speak across time with ultimate clarity. The fossils with which scientists reconstruct our family tree are often fragments that offer hints and clues to where we came from. So it comes as no surprise when, as part of the flow of science, researchers offer counter-interpretations to even the most famous of finds.
That’s what happening to Ardi.
Last October Ardipithecus ramidus hit the main stage when, after 17 years of study, a large team led by paleoanthropologist Tim White published its work in the journal Science. The 4.4-million-year-old find shakes up our understanding of our own history, White said—primarily the story of how and when we learned to walk.
Ardi cast doubt on the widely accepted view that our ancestors became bipeds because they left the forest and entered a flatland savanna habitat that demanded it. But Ardi appeared to be a kind of hybrid, comfortable in the trees and on the ground. And, White said, analysis of the site where the fossil was found indicated that Ardi lived in a woodland habitat. If it’s true that early humans walked in the woods, then the “savanna hypothesis” would be swept away.
Poke a snail with a stick and it remembers for a day. Poke a snail with a stick after you’ve given it methamphetamine and it remembers for much longer.
Getting gastropods hooked on meth perhaps sounds cruel, but Barbara Sorg and her team are among those scientists trying to figure out how the drug works in the brain to produce intense connections that feed the addiction cycle. In a study forthcoming in the Journal of Experimental Biology, the scientists show that, in snails at least, meth makes it hard to forget things that happened while on the drug.
Here’s the test: The snails Sorg studied can breathe two ways, through their skin underwater and also through a breathing tube they can deploy when they surface. The team kept two groups of snails—one on meth, one not—in separate tanks of shallow water. And if the snails tried to surface and breathe that way, the scientists would poke them.
After nearly forty days of wandering in the wilderness of failure and frustration, is this the time that BP finally closes off its oil leak?
There’s a glimmer of optimism in the Gulf of Mexico right now, as the “top kill” appears to have stopped the flow of oil. But with everything that’s happened so far, people are watching nervously and holding off on any celebration until we know the leak is sealed at last.
“They’ve been able to stabilize the wellhead, they’re pumping mud down it. They’ve stopped the hydrocarbons from coming up,” said Coast Guard chief Thad Allen, who is coordinating the US government’s battle against the oil spill. He told local radio WWL First News that BP “had some success overnight” but cautioned the British energy giant was “in a period of kind of wait and see right now where they see how the well stabilizes” [Discovery News].
The likelihood of long-term success grows with the passing hours, though, for the sake of caution, it may be tomorrow before BP declares victory on this. It took a lot of pumping heavy mud just to get to this point:
Indonesia, because it’s an archipelago, might not look like it has a lot of land area. But it’s home to the third largest forest area of any country, and has half the tropical peatlands in the entire world. These forested lands are home to many endangered species, and also store greenhouse gases. Now, thanks to international cooperation (and a big check), more of that area will be saved—for now.
This week, Indonesia pledged to stop giving permits for the destruction of virgin forests:
“We will conduct a moratorium for two years where we stop the conversion of peat land and of forest,” President Yudhoyono said at a joint news conference with Norwegian Prime Minister Jens Stoltenberg. The pledge comes ahead of Thursday’s climate and forest conference in Oslo, which is expected to be attended by officials from some 50 countries [BBC News].
Environmentalists are cheering the reprieve, noting that vast swaths of forest have already been cleared in Indonesia to provide wood for timber and paper industries, and to provide space for palm oil plantations.
In the meantime, you can now say that the BP oil spill is the worst in our nation’s history, eclipsing the 11 million gallons spill by the Exxon Valdez.
In a teleconference this morning, U.S. Geological Survey head Marcia McNutt released the new estimates by her scientists trying to gauge the flow rate of the oil leak. There were two teams working—one watching the surface and the other monitoring the video feed from the leak site. The low estimate is now 12,000 barrels per day, but it may be more like 19,000 to 25,000, the teams found. (The previous estimate, repeated throughout the first month of the spill, was just 5,000 barrels per day).
McNutt wouldn’t say explicitly if the BP spill is now the worst the United States has ever seen, but the numbers speak for themselves. If we do a very conservative calculation and say that 12,000 barrels leaked every day between April 22, when the Deepwater Horizon rig sank, and May 17, when BP installed the siphon to catch some of the oil, you get approximately 13.1 million gallons of oil released into the Gulf’s waters (there are 42 gallons in a barrel of oil).
And keep in mind that’s just the conservative estimate; it’s probably a lot worse than that. The AP did a similar calculation, assuming that either 12,000 or 25,000 barrels leaked every day from the rig’s explosion on April 20 to the present moment, and came up with even more dire figures.
The new government estimate means at least 19 million gallons and maybe as much as 39 million gallons have leaked in the five weeks since an oil rig exploded and sank [AP].
Recent posts on the BP oil spill:
80beats: “Top Kill” Operation Is Under Way in Attempt to Stop Gulf Oil Leak
80beats: BP To Switch Dispersants; Will Kevin Costner Save Us All?
80beats: Scientists Say Gulf Spill Is Way Worse Than Estimated. How’d We Get It So Wrong?
80beats: Testimony Highlights 3 Major Failures That Caused Gulf Spill
80beats: 5 Offshore Oil Hotspots Beyond the Gulf That Could Boom—Or Go Boom
Image: NOAA (the Exxon Valdez)
Yesterday morning, about 70,000 feet over the Pacific Ocean, the Boeing-designed X-51A Waverider “scramjet” set a new record. Reaching Mach 5 (almost 4,000 miles per hour), it wasn’t the fastest jet flight, but by burning for over 200 seconds it became the longest flight of its kind. The previous scramjet record, held by the NASA X-43, was 12 seconds.
A scramjet is similar to a simpler engine called a ramjet, but faster. The engines on most commercial jets have turbines to push air inside, but a ramjet is basically a tapered tube. As air flows through it, the shape of the tube compresses the air and, once the engine mixes this air with fuel, it ignites.
Unlike well-understood ordinary ramjets, which slow the air passing through them to subsonic speeds, the X-51 is intended to maintain combustion in a supersonic internal airflow — hence the name scramjet, for supersonic combustion ramjet — a feat often likened to “striking a match in a hurricane”. [The Register]
This is not an “eat dirt for your health and happiness” study. You don’t need to shovel soil in your mouth. Just go outside.
Biologist Dorothy Matthews and company wanted to test a particular bacteria, Mycobacterium vaccae. It’s found commonly in the soil and carried widely through the air, so if you take a walk in the park you’ll probably breathe it in. Previous studies have shown that the bacterium increases serotonin in the brain, and have even suggested that the bacterium has antidepressant qualities. Since the neurotransmitter serotonin is also involved in cognition, the team wanted to see if the bacterium could have a direct effect on learning. Indeed it did, Matthews’ team announced at the General Meeting of the American Society for Microbiology in San Diego.
In a classic test of learning ability, Matthews gave mice a treat – white bread with peanut butter – as a reward to encourage them to learn to run through a maze. When she laced the treat with a tiny bit of Mycobacterium vaccae, she found that the mice ran through the maze twice as fast as mice that were given plain peanut butter [New Scientist].
That’s not cloud cover. It’s polar ice on Mars, about 600 miles across and covered with deep etchings. The dark valley on the right, named Chasma Boreale, is about the size of the Grand Canyon.
This riven Martian arctic was a mystery to scientists for over forty years. But data from NASA’s Mars Reconnaissance Orbiter has given researchers some important clues to how the ice spirals formed. Their findings appear in two papers published in the journal Nature.
Data from Mars now points to both the canyon and spiral troughs being created and shaped primarily by wind. Rather than being cut into existing ice very recently, the features formed over millions of years as the ice sheet grew. By influencing wind patterns, the shape of underlying, older ice controlled where and how the features grew. [NASA] Read More