| Findings
January/February 2004
Kingdom of the small
by Bruce Fellman
Last year, a tiny microbe previously unknown to science was discovered north of Iceland, in an underwater hydrothermal vent where temperatures approach the boiling point of water. But what, exactly, was it?
"Nanoarchaeum equitans didn't really fit into any known category," says Dieter Soll, the Henry Ford II Professor of Molecular Biophysics and Biochemistry. He is member of a scientific team that suggests the minuscule organism, which is about 100 times smaller than a red blood cell, is so strange that it merits a kingdom all its own.
For decades, biologists could neatly divide life into two kingdoms -- plants and animals -- but the scheme has become more complicated. Many researchers now recognize three top-level "domains": Bacteria, Archaea, and Eukarya. Each domain is then divided into kingdoms (plants and animals are in Eukarya).
N. equitans was clearly one of the Archaea, but based on its chemical and morphological characteristics, couldn't be pigeon-holed into either of the two Archaean kingdoms. Thus was born the kingdom Nanoarcheota, which currently has only one member.
"This may be a very ancient organism and close to the root of the three domains," says Soll. "It also has the smallest, most densely packed genome we've ever found." In the October 17, 2003, issue of the Proceedings of the National Academy of Sciences, Soll and his colleagues explained that the microbe is a parasite that lives on a larger archaean. "Almost the entire genome of N. equitans is devoted to the machinery for information processing," says Soll. "It can make copies of itself, but all its raw materials have to come from its host."
Of particular interest to Soll is N. equitans's "split genes," stretches of widely separated genetic code that make bits of protein that are somehow joined together. "We don't have split genes," says Soll, "so this and many other things about this organism might represent the ancestral condition."
Babies and emotional intelligence
by Alexandra Galin '06
When do children start becoming attuned to other people's behavior? The standard answer has been at three to five years. But now Valerie Kuhlmeier, a postdoctoral fellow in the Department of Psychology, says it's actually much earlier. "Somewhere between 9 and 12 months of age, infants begin to do things that make people believe they are becoming real social beings -- that they are paying attention to people's goals, intentions, and maybe even emotions," says Kuhlmeier.
In research published in the September issue of Psychological Science, Kuhlmeier and her Yale colleagues used short computer animations to study this issue. In the investigation, 20 infants with an average age of 12 months watched at least half-a-dozen computer animations, each about ten seconds long, in which a ball attempted to go up a hill. In one sequence the ball was helped up the hill by a square but pushed down it by a triangle. (Some infants saw the reverse.) After this "habituation" phase, the babies watched an animation in which the ball went to either the helper or the hinderer object.
Kuhlmeier found that despite the maddeningly short attention spans of her young subjects, the babies looked longer at the movies in which the ball went to the helper. The difference was between one and four seconds.
In other studies she has found that infants as young as nine months showed a looking-time difference, provided the shapes were animated with faces. "They require morphological cues -- more-animate objects," said Kuhlmeier, adding that "the more we know about how normal infants develop, the more we can answer the question of why normal development derails."
The mind of the beholder
by Jennifer Kaylin
Marlene Schwartz, associate research scientist in the psychology department, and colleagues recently administered an unusual test to 389 clinicians. The doctors, all of them attendees at an international conference on obesity, were put through a high-speed word association exercise in which they had to match the words "thin" or "fat" with words such as "lazy," "motivated," "stupid," and "smart."
The study uncovered a surprisingly strong bias against fat people. "We found that even those most knowledgeable about the condition believe overweight people are somehow to blame for their problems," says Schwartz. (The study was published in the September edition of the journal Obesity Research. The test is available online at www.weightbias.org.)
Carol Johnson, who runs Largely Positive, a Milwaukee-based organization for the overweight, has had first-hand experience with this bias. When Johnson discovered she had high blood pressure, her doctor's first suggestion was, reasonably enough, that she lose weight. A few months later, when he saw no improvement in her condition, he advised her to try harder. "That's when I got annoyed," Johnson says. "My mother and grandmother both had high blood pressure, so there's a family history. I asked him, 'If I were a thinner person you'd give me medication, right? So why can't I have medication?'"
Eventually her physician relented, and today Johnson says her blood pressure is just where it should be, although she's still about 60 pounds overweight. She argues that the incident is typical of the kind of attitude health care providers have toward their larger patients: "If you have a health problem it must be due to your weight, and if you can't lose the weight, it's because you're lazy and lack self-control."
Dr. Drew Palin, a physician who has treated patients with obesity in Milwaukee, admits to having had an anti-fat prejudice. "I had a strong bias against obesity because I've been a pretty serious athlete and exerciser all my life," he says. But his patients finally showed him his blind spot. "I had some who weren't losing any weight," he recalls. "They'd come in and tell me, 'Doc, I'm only eating a thousand calories a day.' At first I thought they must be lying to me, but everyone was telling me the same story. Finally I realized that their metabolisms are just very slow, and their bodies are holding on to that weight for protection."
Exposing doctors' attitudes is important, says Schwartz, because it can affect medical care. "Patients have told me they avoid going to the doctor for regular things like mammograms because they know they'll get a lecture about their weight," she says. So far, she says, the response to her findings from clinicians has been accepting. "They acknowledge we all grew up in the same society, exposed to the same messages."
The politics of breathing
by Marc Wortman
Politicians are not known to devour scientific journals, but, according to Yale public health scientist Janneane Gent, "the attention was instant" when a paper she co-authored appeared in October in the Journal of the American Medical Association. The study showed that even small increases in ozone levels in the air can start asthmatic children wheezing and turning to medication for relief. It was published amidst the raucous political debate over the Clear Skies Act, new legislation proposed by the Bush administration. "It's a question of timing," says Gent.
Ozone, the major component in smog, is formed when the sun acts on certain pollutants, emitted mostly by motor vehicles, power plants, and factories. Physicians urge parents of the nation's 3.5 million asthmatic children to keep them inside and quiet when ozone levels reach the limit judged unhealthy by the Environmental Protection Agency. But that limit may need to be revisited.
In the first study of the impact of low ozone levels on children with asthma, a Yale team followed 271 asthmatics under age 12 in a region of Connecticut and Massachusetts where air pollution normally remains at levels the EPA considers acceptable. From April through September 2001, the investigators tracked parents' reports of their children's asthma symptoms against ozone levels.
The results showed that for each 50-parts-per-billion increase in ozone levels, there were a 35 percent increase in the risk of wheezing and a 47 percent increase in the risk of chest tightness. "What this means," says Gent, "is that we begin to see health effects at an ozone level that is about half what the standard is." (The current limit is set at a maximum of 120 parts per billion in 24 hours.) Parents of asthmatics who were already taking medication to prevent wheezing also reported increases in their children's use of "rescue" medication -- a typical sign of a serious asthma attack.
The same study, which was undertaken as part of long-term research into the causes of asthma, found that increases in another controversial pollutant -- fine particles of dust, smoke, soot, and other material -- had no impact on asthma symptoms. (Fine particle levels, says Gent, were very low that summer.)
Connecticut attorney general Richard Blumenthal '73JD says that the proposed Clear Skies Act would weaken the existing limit on ozone, causing "an immediate and significant impact of further diluting an air quality standard that already is inadequate to protect our children." Along with attorneys general from 13 other states, Blumenthal has filed a lawsuit to block Bush administration rules that, they contend, would increase power plant emissions. "This study is very powerful ammunition in our litigation," he says.
EPA officials also read the study, but they view it differently. John Millett, an EPA spokesman, says, "We're grateful for this research. We're getting more detailed information on levels that help us determine the best way to protect people. We depart in the contention that the EPA is backsliding somehow. That is simply not the case."
Whatever the outcome, Brian Leaderer, the Susan Dwight Bliss Professor of Public Health and principal investigator for the study, says the results answer one question: "Do current air quality standards protect the most susceptible segments of the population? Clearly they do not."
Appalachian desert
by David B. Williams
One of the greatest deserts of the earth's history exists now only as a series of massive rock cliffs in southern Utah. The formation, known as Navajo Sandstone, was created from a sea of sand that covered an area the size of Texas 190 million years ago. The original source of all that sand, however, has been a mystery. Geologists have speculated that it was carried by prevailing winds from nearby, long-eroded-away mountains known as the Ancestral Rockies, or that it was blown west from as far away as the Ouachita Mountains of Arkansas.
But in a paper published in the September edition of the journal Geology, Yale researchers Jeffrey Rahl and Peter Reiners suggest a surprisingly distant source for the ancient desert: the Appalachian Mountains. Rahl and Reiners maintain that the material was carried to the desert, more than 2,000 miles westward, by a transcontinental river system that, 225 million years ago, rivaled the Amazon.
The scientists base this remarkable scenario on evidence they gathered using a new variation, pioneered by Reiners, of a geological dating technique called thermochronology. The technique dates temperature-related geological events -- such as the cooling of lava into rock -- using the rate of decay of radioactive elements in that rock. Reiners, an assistant professor of geology and geophysics, and Rahl, a graduate student, improved on thermochronology by using two separate radioactive-dating methods. "Their work is a huge leap forward," says University of Arizona geology professor George Gehrels. "They've come up with a very powerful tool for using the cooling and crystallization histories of individual minerals to pinpoint the source of materials."
The two looked specifically at zircon in the Navajo Sandstone. Using uranium-lead dating, they found that it had crystallized between 1.2 billion and 950 million years ago. Then, using helium dating, they showed that the mineral underwent a second major geologic upheaval between 400 and 250 million years ago. The first set of dates corresponds with a mountain building event known as the Grenville Orogen, the second with the uplift of the Appalachians. Subsequent erosion of the Appalachians carried sediments west in a mammoth river that flowed across the continent to places where prevailing winds could transport the sands south to the great desert.
Reiners is also using thermochronology to date mountain building and erosion events in Washington State's Olympics, the Italian Apennines, and the Himalayas. "There are questions about earth history that have long been asked," says Reiners. "Now we have the technology to answer them." 
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