 |
||
 |
|
|
 |
 |
 |
 |
 |
 |
 |
 |
The Yale Alumni Magazine is owned and operated by Yale Alumni Publications, Inc., a nonprofit corporation independent of Yale University. The content of the magazine and its website is the responsibility of the editors and does not necessarily reflect the views of Yale or its officers. |
|
When Fred Volkmar began studying autism in children some two decades ago, “people didn’t know what the word meant,” he recalls. “They’d say to me, ‘Gee, that’s great. We need more children to be artistic.’” Today the condition is far more widely recognized, but early diagnosis that might improve the chances of helping children overcome the severe social disability has proven elusive. Using methods that he and colleagues at the Yale Child Study Center developed, Volkmar expects soon to be able to diagnose autism even during infancy, years earlier than once believed possible. Earlier diagnosis could lead to treatment sooner in a child’s life, significantly improving the chances for more normal development. Autism severely limits a person’s ability to interact and communicate with others. People with autism often rock themselves, engage in self-destructive acts, vocalize nonsense sounds, and have difficulty comprehending normal human emotions and communication. Although signs of autism may show early in life, a diagnosis using current standard methods is often not possible until a child reaches age five or later, because many children with behaviors that could signal autism eventually mature more normally. For a child with autism, though, such a late diagnosis may close off the chances that treatments could improve his or her ability to think, speak, and react to others in more normal ways, possibly, explains Volkmar, because of the brain’s decreasing malleability as it develops. Currently, specialists diagnose autism using what Volkmar, the Irving B. Harris Professor of Child Psychiatry, Pediatrics, and Psychology, calls a “paper-and-pencil checklist”—based on characteristics such as shrinking from human touch or delays in learning to speak. Along with Ami Klin, the Harris Associate Professor of Child Psychiatry, and graduate student Warren Jones, Volkmar developed an eye-tracking technique that enables researchers to measure an infant’s eye movement in response to visual cues, as well as the ability to focus on people in general. Volkmar, Klin, and Jones have shown that normal infants' eyes will follow human forms when presented with animations of people among objects. Autistic children’s eye movements will not differentiate between the people and the objects. The scientists also measure other types of responses to people that correlate very early in life with the eventual development of autism. In a paper published in the November issue of the American Journal of Psychiatry, a team led by Volkmar and Klin used a variety of these emerging diagnostic techniques to test a 15-month-old toddler. She was considered at high risk of developing autism because she had a sibling with the condition and she had stopped using words she had already learned. After the team diagnosed her as autistic using their methods, later follow-up with more standard tests confirmed the diagnosis. “We can now make a diagnosis and begin interventions in the first or second year of life,” Volkmar says. He eventually hopes to be able to diagnose autism within the first six months of life. “Early diagnosis can make a big difference. There’s a real payoff for families in the potential for helping their autistic children live more normal lives.”
Ethnic Cleansing, Before the Indians At three in the afternoon on Friday, September 5, 1755, British colonel John Winslow read a proclamation to the men of Grand Pre, a largely French-speaking community on the coast of Nova Scotia. “Your Land and Tenements, Cattle of all kinds, and Livestock of all sorts are forfeited to the Crown with all other [of] your Effects, saving your Money and Household Goods,” Winslow declared. “And you yourselves are to be removed from this province.” So began the deportation of the Acadians, the French colonists who had been in Nova Scotia since 1606. When the campaign against them started in Grand Pre, there were about 18,000 Acadians in the Canadian maritime colonies. When it ended eight years later, 10,000 had died and most of the survivors had been sent in small groups either back to France or to other American colonies. The English justified the purge as a “cruel necessity” in the war for domination of North America that England and France were about to commence. But John Mack Faragher, the Arthur Unobskey Professor of American History, has a more modern term. “The removal of the Acadians was the first episode of state-sponsored ethnic cleansing in North American history,” writes Faragher in his new book, A Great and Noble Scheme: The Tragic Story of the Expulsion of the French Acadians from Their American Homeland. Working with recently discovered documents and reinterpreting others, Faragher, director of the Howard R. Lamar Center for the Study of Frontiers and Borders, demonstrates how the British put together, as much as two years in advance, an operation to rid the Maritimes of a civilian population that was feared as a potential fifth column. In an August 1755 letter widely reprinted in colonial newspapers, a correspondent wrote that the Acadians “have always been our secret Enemies, and have encouraged our Savages to cut our throats.” Neither charge has any weight, says Faragher. For while the Acadians had steadfastly refused to swear unconditional oaths of allegiance to the British crown, the so-called “neutral French” sided with neither France nor England and tried to live peacefully with both. Nor, before the expulsion order, did the Acadians incite the Micmaqs against the British. (However, the Acadians who avoided deportation soon joined with the Indians in a guerrilla campaign.) But if a preemptive strike to enhance security in the colonies was not justified from a military perspective, there was another reason to purge the Acadians from Nova Scotia. It provided farmland for American immigrants, largely from Massachusetts. Such a program could not happen without government support. “These were neither pogroms nor disorganized and spontaneous folk removals,” says Faragher. “Just like the Holocaust and other ethnic cleansing episodes throughout the twentieth century, this was a top-down operation that required central planning and resources.” Le grande derangement—the Acadian term for the expulsion—was clearly effective. When the war ended in 1763 the Acadians allowed to return came home as tenant farmers in an Anglicized country. “The French names were removed, and many of the Acadian records were destroyed,” says Faragher. “One group was dispossessed, and another group repossessed the land. It was the first instance of what would become a familiar pattern.”
A New Way to Fight Lyme For four years, Durland Fish and Jean Tsao ran a Lyme disease vaccination clinic whose patients were all mice. Fish, a professor of epidemiology, and Tsao, a post-doc, designed the vaccination effort as an experiment to find out whether immunizing mice against the disease could help protect humans. They captured and vaccinated more than 1,000 white-footed mice in a forested area near New Haven (when it comes to disease management, says Fish, “this is a hard way to do it”). Recently, they reported that the technique works—sort of. The partial success has them eyeing a new target: robins. Humans contract Lyme disease from deer ticks. Because deer are one of the ticks' favorite foods, the dramatic increase in the deer populations of the Northeast and Midwest is often cited as a major cause of human Lyme disease cases in those regions. (The Centers for Disease Control reported 24,000 cases in 2002.) But in fact, deer are minor players, because they can’t be infected by the Lyme bacterium. Where are the Lyme spirochetes hiding? “We’ve long thought that mice were the primary reservoir of infection,” says Fish. And in fact, his mouse vaccination program had an effect. Fish and colleagues reported in the Proceedings of the National Academy of Science in December that, in areas where nearly two-thirds of the mice were successfully immunized, the number of infected ticks dropped by around 25 percent. But Fish says this result suggests that the role of the white-footed mouse in spreading Lyme may be overrated. Moreover, even if it were possible to vaccinate all the mice in a given area—by setting out mouse food laced with an oral vaccine, for instance—a significant number of infected ticks, capable of infecting humans, would remain. Fish and other researchers have ruled out raccoons, skunks, opossums, and chipmunks as important reservoirs of the infection, and studies have shown that the gray catbird plays no role in spreading the disease. But the biologist has his eye on another winged culprit. “Robins turn out to be really good reservoirs,” says Fish. “There is research demonstrating that almost all ticks feeding on these birds get infected.” Robins had never been a leading suspect in the Lyme cycle, but Fish suspects that they may be extremely important. They spend a great deal of time on the ground, where they often come in contact with ticks, he notes, and they are abundant in the residential areas where most Lyme cases are acquired. Birds have already been implicated in the transmission of other emerging diseases, West Nile fever in particular, and Fish is beginning a study to understand the overall importance of avian reservoirs in passing on human pathogens. As yet, however, he has no plans to set up a drop-in vaccination center for robins.
The Consequences of Competition When competition for its favorite prey—clams—is fierce, the Atlantic-dwelling muricid snail, Chicoreus dilectus, takes the fastest available route to dinner: it drills a tiny gap at the clamshell’s edge with its rasped tongue and a cocktail of chemicals. The shell is thinnest here, and the process takes only a couple of days, but it’s risky. The odds that the clam will nip off the snail’s feeding proboscis are high. When fewer predators are around to compete for clams, however, C. dilectus tackles its prey in a safer, more leisurely way, taking about a week to drill through the shell wall. Gregory Dietl, a Yale postdoctoral fellow in geology and geophysics, demonstrated these behaviors in the lab. But Dietl and his colleagues (including University of California-Davis paleontologist Geerat Vermeij '71PhD) have also used the phenomenon to explore the effects of a major extinction 1.7 million years ago in the western Atlantic. Their findings were published in a December 2004 issue of the journal Science. The scientists originally became curious about the effects of extinction on competition when they noticed a trend in the fossil record: edge-drilled clams were replaced almost entirely by wall-drilled clams at the time of the die-off. Suspecting the snails had responded to a reduction in predator numbers, Dietl’s team simulated different levels of competition in the lab. They found that when several snails were housed in the same tank, 37.5 percent of the clams that were consumed showed edge drilling. But when each snail was housed alone, only 2.6 percent of the clams did. “Snails that had no contact with other predators abandoned the edge-drilling behavior,” Dietl says. “That’s consistent with what we see today in the wild.” C. dilectus is a cautionary tale of how the plunge in competition that follows a major extinction can forever affect the remaining species. “We tend to home in on diversity and say, ‘If we’re not losing species, we’re doing okay,’” Dietl notes. “But that’s not the whole story.” |
Noted Another reason for teens to avoid tobacco: in the January issue of Biological Psychiatry, Leslie Jacobsen, associate professor of psychiatry and pediatrics, and her colleagues at the medical school report that adolescent smokers, compared to teen non-smokers, experience significant declines in working memory, the short-term ability to retain information such as a phone number. Joseph Santos-Sacchi, professor of surgery and neurobiology, has identified a new threat to whales. In the March issue of the Biophysical Journal, he shows that tributylin oxide, a chemical painted on boat hulls to prevent barnacle colonization, can damage the outer hair cells of marine mammals—cells critical to underwater hearing and communication. Dark matter may be invisible, but using Hubble Space Telescope data, astrophysicist Priyamvada Natarajan found that the enigmatic material has a kind of structure. The researcher and her colleagues discuss the clumpy nature of dark matter, which makes up 90 percent of the mass of clusters of galaxies, in the December 10 issue of Astrophysical Journal Letters. Yale researcher A. David Patiel and his colleagues have shown that a greatly expanded program of HIV testing is a cost-effective means of preventing the spread of the disease and increasing the life spans of people infected with the virus. Patiel’s study appeared in the February 10 issue of the New England Journal of Medicine. |
|
|
|
|
|
|
|
|
|
||
|
||
©1992–2012, Yale Alumni Publications, Inc. All rights reserved. Yale Alumni Magazine, P.O. Box 1905, New Haven, CT 06509-1905, USA. yam@yale.edu |
||