Blogs / 80beats

They call it the Mars dichotomy, or say that the planet is “two-faced.” Researchers have known for decades that the Red Planet is divided between smooth, low-lying plains in the north, and craggy, cratered highlands in the southern hemisphere. Mars orbiters have also confirmed that the planet’s crust is thinner in the north.

Now, a new study offers an explanation for this strange phenomenon: Around 4 billion years ago, an enormous asteroid smashed into Mars and changed the character of its northern half. “This impact is really one of the defining events in Mars’ history,” said [study co-author] Jeffrey Andrews-Hanna…. “More than anything this has determined the shape of the planet’s surface” [USA Today].

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Cysticercosis. Brucellosis. Dengue Fever. The names of these diseases are not familiar to most Americans, and they’re so obscure that U.S. doctors often don’t think to check for them. But a new analysis shows that these infectious diseases, which are usually associated with developing countries in the tropics, are surprisingly common in the poorer areas of the United States.

Peter Hotez, the report’s author, says the diseases go untreated in hundreds of thousands of poor people who live mainly in inner cities, the Mississippi Delta, Appalachia and the Mexican borderlands…. Hotez says it is a “disgrace” that diseases causing so much suffering remain at the bottom of the national health agenda. “If this were occurring among white mothers in the suburbs, you’d hear a tremendous outcry,” says Hotez, a microbiologist at George Washington University [USA Today].

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The International Whaling Commission’s annual meeting is almost always a quarrelsome affair, with Japan pressing for less stringent rules on whale hunting and environmental groups shouting about the need for stronger protections for the marine mammals. But this year’s meeting, which began on Monday, became strangely peaceful yesterday, as opposing sides celebrated a rare agreement–an agreement not to talk about the hard stuff until next year’s conference.

The most controversial topics before the commission are Japan’s demand to lift the ban on commercial whaling in its coastal waters, and a proposal by South American nations to create a whale sanctuary in the South Atlantic where hunting would always be prohibited. The international commission agreed to table both of these questions, and decided that over the next year a 24-nation working group … will meet in private to thrash out the most contentious issues that have left the whaling body so deeply divided [Australian Associated Press (AAP)].

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Little electronic chips called radio frequency identification devices (RFIDs) have been popping up everywhere in hospitals, and for the most part that’s a very good thing. The small devices are attached to all sorts of objects to help hospital staff keep track of their equipment–the chips are even implanted in surgical sponges so doctors can make sure they haven’t left any inside their patients.

But a new study suggests that RFIDs may not be entirely safe in a hospital setting, and that the wafer-thin chips could interfere with critical hospital equipment like pacemakers and mechanical ventilators. When a team of Dutch researchers tested the chips’ effects on various medical devices, they found potentially dangerous interference in more than 15 percent of cases.

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People may think they’re making up their own minds when they step into the voting booth on election day; they may think that the decision they make there is a product of careful reflection and personal values. But a new study suggests that voters may be swayed by the simplest factors, like the associations they have with the physical place where they vote. In the study, researchers showed that people who cast their votes in a school were more likely to support an education initiative.

“Seemingly innocuous factors can influence behavior,” said Jonah Berger, assistant professor of marketing at the Wharton School of the University of Pennsylvania, and the study’s lead author. “There is a connection between location and the thing people are voting on” [ABC News Medical Unit].

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The news just keeps getting better about vitamin D. Earlier this year, studies linked proper levels of the “sunshine vitamin” to a decreased risk of diabetes, heart attacks, and cancer; that’s in addition to the previously understood role that vitamin D plays in keeping bones strong. Building on all these findings, a new study suggests that maintaining proper levels of the nutrient can even stave off death from heart attacks and other causes.

Researchers point out that they haven’t yet demonstrated a causal relationship, just a connection. The study’s lead author, Dr. Harald Dobnig of the Medical University of Graz in Austria, said the results don’t prove that low levels of vitamin D are harmful “but the evidence is just becoming overwhelming at this point” [AP]. Researchers aren’t sure what the connection is but they speculate that the nutrient may play a role in regulating the immune system, and may also have an anti-inflammatory function that keeps the heart healthy.

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The U.S. Supreme Court has agreed to take on the above question in its next term, when it will wrestle with a complicated lawsuit between the Navy and the Natural Resources Defense Council. For years, the environmental group has been fighting to limit the Navy’s use of sonar in training exercises off the California coast, arguing that the sonar injures and disorients whales and other marine mammals.

Environmentalists successfully sued the Pentagon over the practice in March, forcing major changes in the Navy’s annual offshore training exercises. A federal judge ruled it was “constitutionally suspect” for President Bush to issue a national security exemption so no environmental impact assessment was carried out [CNN]. The Supreme Court won’t try to determine whether the sonar is causing confused whales to beach themselves, but will instead weigh in on whether the executive branch had the right to preempt an environmental law by granting the exemption to the Navy.

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On April 16, 1178 B.C. a total eclipse blotted out the sun at high noon; astronomers know that much for certain. The other events of that day are considerably less definite, but researchers say the date may also figure large in Homer’s Odyssey, the epic tale of Odysseus’s journey home to Ithaca after the Trojan War. Using astronomical clues from the text, researchers say that Homer may have indicated that the day of the eclipse was also the day that Odysseus finally reached home–arriving just in time to slaughter his wife’s persistent suitors.

While the researchers believe they’ve arrived at the proper date for Odysseus’s homecoming in the Odyssey, they don’t claim to have proven that all the events in the epic are real; it is, after all, packed with gods, monsters, and magic. But researcher Marcelo Magnasco says his findings could at least demonstrate Homer’s astronomical erudition. “Under the assumption that our work turns out to be correct, it adds to the evidence that he knew what he was talking about,” Magnasco said. “It still does not prove the historicity of the return of Odysseus,” he said. “It only proves that Homer knew about certain astronomical phenomena that happened much before his time” [AP].

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It seems counterintuitive, because anesthetics are supposed to knock out patients and make them numb to all the jolts, jabs, and twinges of surgery. But a new study shows that many anesthetic drugs actually stimulate parts of the nervous system that sense pain, and can lead to increased discomfort after surgery.

Surgeons already knew that some knock-out drugs cause a burning sensation at the site of injection or in the lungs if the drug is inhaled, but the new research illuminates the mechanism of that response, and helps explain postoperative pain that was thought to be a result of the surgery exclusively. “Probably what is most significant for people to know is that this activation of a pain channel actually adds to post-surgery inflammation, so what we didn’t know before was that you could exacerbate swelling of surgery-damaged tissue with general anesthetics,” says Georgetown neuroscientist Gerard Ahern, who oversaw the new study [Science News].

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Neanderthals don’t have the best reputation. In the public mind, the heavy-browed hominids are thought of as a stupid species that couldn’t compete with brighter Homo sapiens, as the also-rans that therefore went extinct. But a newly discovered trove of Neanderthal tools in Sussex, England may help rehabilitate their image. The tools, which date from the end of the Neanderthal era at around 30,000 B.C., show surprising sophistication, archaeologists say.

“The tools we’ve found at the site are technologically advanced and potentially older than tools in Britain belonging to our own species,” said [University College London]’s Matthew Pope. “It’s exciting to think that there’s a real possibility these were left by some of the last Neanderthal hunting groups to occupy northern Europe,” he added. “The impression they give is of a population in complete command of both landscape and natural raw materials with a flourishing technology — not a people on the edge of extinction” [Discovery News].

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Who knew that baby crocodiles are such tender little creatures? According to researchers, they start crying out for their mothers before they’ve even cracked their shells and poked their long noses out into the world: The little crocs make an “umph! umph! umph!” sound right before they hatch [Reuters]. Now a study has shown that the noises they make from within their shells aren’t just idle chatter, but instead play an important role in the hatching.

A team of French researchers studied Nile crocodiles, and found that the calls prompted mother crocodiles to dig the eggs out of the dirt. The cries also seemed to alert all the babies inside their shells that it was time to hatch, leading to a neatly synchronized hatching that could have an evolutionary benefit, researchers say.

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The human brain is packed with star-shaped cells called astrocytes; they make up about 50 percent of cells in the cerebral cortex, and far outnumber the neurons that process and transmit information. Yet until recently, researchers thought these ubiquitous brain cells were fairly unimportant to the brain’s functioning. Now a new study rebuts that theory, and indicates that astrocytes play a major role in sending blood to areas of brain activity.

In the study, a team of MIT researchers peered into the visual cortex of live ferrets with an advanced microscope to watch how the brain cells responded to visual stimuli. “Electrically, astrocytes are pretty silent,” study co-author James Schummers said…. “A lot of what we know about neurons is from sticking electrodes in them. We couldn’t record from astrocytes, so we ignored them.” The researchers changed this perception by imaging astrocytes with two-photon microscopy. “The first thing we noticed was that the astrocytes were responding to visual stimuli. That took us completely by surprise,” Schummers said. “We didn’t expect them to do anything at all. Yet there they were, blinking just like neurons were blinking” [HealthDay News].

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Foot-and-mouth disease, a viral disease that affects cows and other cloven-hoofed animals, is not something to play around with. It’s so contagious that when an outbreak occurred in Britain in 2001, the government slaughtered 6 million cows, sheep, and pigs to contain its spread.

Still, researchers need to study the virus somewhere in order to develop vaccines and treatments. At the moment the only place for that research within the United States is the Plum Island Animal Disease Center, located on a small island a few miles off the tip of Long Island. But the government has declared that facility outdated and hopes to build a new $450-million facility somewhere on the mainland, kicking up a round of “not in my backyard” complaints. The lab’s prospective neighbors have reason to be nervous; a new government study says that a breach at the lab could decimate nearby herds and cost the American economy $4 billion.

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Well, that’s a relief. After a long safety review, physicists have declared that the enormous atom smasher that’s expected to go online this fall won’t create tiny black holes that will “eat” our planet. So that’s one less thing to worry about.

The Large Hadron Collider, which is being built near Geneva, Switzerland, will do things with subatomic particles that humans have never done before, causing some people to worry that scientists might be unwittingly building a doomsday devise. The $8 billion machine is designed to accelerate protons, the building blocks of ordinary matter, to energies of 7 trillion electron volts and then bang them together to produce tiny primordial fireballs, miniature versions of the Big Bang. Physicists will comb the detritus from those fireballs in search of forces and particles and even new laws of nature that might have prevailed during the first trillionth of a second of time [The New York Times].

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When an experiment finds out that a treatment doesn’t work as expected and that a cherished hypothesis just isn’t right, it’s not considered as newsworthy as an amazingly effective treatment that sparkles with potential. But the negative findings are just as important in their contributions to medical knowledge.

In that category, a new study dismisses the theory that treating herpes reduces patients’ risk of HIV infection, a strategy that was believed to hold promise. Researchers wrote in a commentary: It is time to reassess the hypothesis and to adjust prevention policy accordingly [The Lancet, subscription required].

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