Although male pattern baldness affects some 80% of Caucasian men by age 70, it’s remained a puzzle to scientists. Existing treatments were discovered by chance: Rogaine was originally a drug for high-blood pressure and Propecia was for prostate enlargement. In a new study, however, researchers have identified a molecule called Prostaglandin D2 (PGD2) that inhibits hair growth in men, which could provide a target for future drugs designed to treat baldness.
The first thing researchers did was find a good use for the scalp fragments, usually discarded, from men undergoing hair transplant surgery. (Well, where else do you find volunteers to get scalped?) Comparing bald and non-bald tissue from these scalp parts, they discovered that the bald scalp had ten times as much PGD2 and elevated levels of PTGDS, the enzyme that makes PGD2, compared to normal scalp. The gene for PTGDS is also expressed more when there’s lots of testosterone floating around, which may explain why baldness is so endemic to men.
Flattened eye of the astronaut.
Without gravity pulling down on fluids in their bodies, astronauts’ faces get puffy and congested. This Charlie Brown effect—so named for the cartoonishly round faces—may be responsible for amusing anecdotes like hot sauce cravings among astronauts, but it could also pose a permanent problem for their eyes. In a new study, MRIs revealed swelling or flattening of eyeballs in an unusually high proportion—11 out of 27—of astronauts examined.
The abnormalities matched what doctors see in Earth-bound patients with idiopathic intracranial hypertension, or high pressure of fluids in the brain, which could be similar to what’s happening in zero gravity. The study’s authors are careful to note that they can’t rule out other causes, such as exposure to radiation, and that they did not look at astronauts who had never been in space for comparison. Nevertheless vision problems are a known hazard of space travel, and NASA is now scanning all eyeballs before astronauts leave for space.
Image courtesy of Kramer et al / Radiology
Who thought a paper on the history of words could have so many graphs? Enter “culturomics,” an emerging field that drops data-crunching into the laps of humanities professors. Armed with the scanned corpus of Google books, researchers published in 2011 the first culturomics paper, which examined the changing popularity of words over time. The paper hinted at all sorts of possibilites: tracking the evolution of irregular verbs, mapping a politician’s rise to fame, identifying censorship when a name suddenly drops in popularity, etc.
A group of physicists have taken up culturomics with a new study that models the birth and death of words in three languages: Spanish, Hebrew, and English. At the same time they’re crunching serious math, they also have an eye on history. Here are a few of their in findings:
Them’s Fighting Words
On Sunday, Cornell University’s corpse flower, a gigantic Sumatran plant that reeks of death, bloomed. It was one of only 140 such plants to bloom in cultivation in recorded history.
The plant’s long central stalk, called a spadix, had been growing by a few inches a day since the beginning of March in preparation for the bloom, finally reaching more than 60 inches in height when the fleshy, dark red leaf around its base eventually unfurled on the 18th. Read More
For frequent readers of this blog and Carl Zimmer’s The Loom, the bacterium Clostridium difficile may ring a bell. It’s a germ that can cause devastating, intractable gut infections, and is one of the reasons behind the recent development of fecal transplants to try to give the patient healthy gut bacteria to fight back with. C. difficile is on more people’s radar these days, and with good reason. A new Centers for Disease Control report shows that infections from C. difficile and another gut pathogen, norovirus, have grown more common and much more lethal in the last fifteen years. In 2007, they killed more than double the people they’d killed ten years before, jumping from 7,000 to 17,000. Most of those who died were elderly.
Chances are, your hard drive is packed with important relics—the first email you sent your spouse, the photographs of your grandma’s 80th birthday, the documents you read for your senior thesis. The data you’ve accrued plays the same role as albums full of pictures, letters, and sentimental objects might have for earlier generations: it constructs a narrative about your progress through life. Or at least it could, if there were a way to have it automatically organized.
This personal data-mining is what what Facebook’s Timeline feature aims to do, but the Timeline is curated manually by the user, includes only files you’ve uploaded to Facebook, and is public, for all your Facebook friends to see (and maybe there are some events in your life you’d like to remember without the whole world peering over your shoulder). So we were interested to read about Lifebrowser, a product being developed in Microsoft Research that automatically arranges your hard drive’s files into a timeline, using machine learning to discern which of them represent landmark events.
Just as Vikings pillaged their way from Norway to Greenland and Iceland 1000 years ago, another group of furry raiders appears to have made a similar trek: common house mice. A new analysis of ancient and modern mouse DNA suggests that the mice in Iceland and Greenland came from Norway.
Scientists began by looking at mitochondrial DNA (mtDNA) extracted from living mice in Iceland and Greenland as well as from mouse bones found in old settlements. The ancient gene sequences were strikingly similar to those of modern mice found in UK and Norway, as well as to modern Icelandic mice, suggesting a common origin in either the UK or Norway. The low genetic diversity in Iceland, to boot, suggests recent colonization by a small number of stowaway mice. These findings have prompted speculation that mice may have arrived in the islands in Viking ships, though there is no evidence that that’s the case.
As scientists continue using human DNA to map our ancestors’ migrations, it’s neat to be reminded that there might be similar patterns of migration in species that tend to live with humans. Perhaps the bones of mice may in the future provide helpful clues for figuring out where ancient humans went and what they brought with them.
[via New Scientist]
A split-brain patient is unable to say what he sees with his nonverbal right brain, but he can draw it.
Half a century ago, patients with intractable epilepsy were presented with a radical surgery: severe the corpus callosum. Cutting this bundle of fibers that allows the left and right brain hemispheres to communicate created split-brain patients. Their epilepsy got better, but a whole host of other strange things happened, such as left and right hands that would fight over what to get at the supermarket.
Nowadays, these patients have access to better drugs and less invasive surgeries, and severing the corpus callosum is no longer done. A dozen or so of these patients have been the subject of countless scientific studies, but they’re all getting older. A recent Nature News feature talks about just how invaluable these patients have been to neuroscience.