Tuesday, July 29, 2008

verbal

You can take a child out of a severely disadvantaged neighborhood and move to a nicer part of town, but you can't always take a bad neighborhood's harmful effects on verbal development out of the child. http://louis1j1sheehan1.blogspot.com

That's the implication of a new, long-term study of children from various Chicago neighborhoods. http://louis1j1sheehan1.blogspot.comKids living in the most disadvantaged communities displayed marked declines in age-appropriate verbal ability over a 7-year span, even after moving to better areas, reports a team led by Harvard University sociologist Robert J. Sampson.

On average, children who at some point lived in neighborhoods characterized by "concentrated disadvantage" exhibited decreases of 4 IQ points on later standardized tests of vocabulary and reading skills. Comparable verbal losses occur when a child misses 1 year of school. http://louis1j1sheehan1.blogspot.com

Concentrated disadvantage consists of a high rate of welfare recipients, high levels of poverty and unemployment, racial segregation, and large numbers of female-headed households and children per household.

Exposure to concentrated disadvantage exerted harsher verbal effects on the youngest kids, the researchers say.

"Taking steps to invest in neighborhoods directly, by creating safe public spaces and quality learning environments for children, is likely a cost-effective way to mitigate the harmful consequences of concentrated disadvantage," Sampson says.

The new findings will appear in an upcoming Proceedings of the National Academy of Sciences.

Sampson's group studied 2,226 children, ages 6 to 12, living in poor, middle-class, and upper-class sections of Chicago. Kids and their parents or caretakers were tracked from 1995 through 2002. In that time, about half of the participants moved from one Chicago neighborhood to another or to other parts of the United States. Interviews with children and caretakers occurred at the study's start and twice more, every 2 to 3 years. At each interview, the children completed a vocabulary and reading test.

The researchers focused on the 772 African-American children in the study. Almost one-third of the black children lived in areas of concentrated disadvantage in 1995, compared with virtually no white or Hispanic children.

About 42 percent of the black children living in the worst neighborhoods in 1995 moved to a nondisadvantaged neighborhood later on. This group still showed a 4-point decline in verbal ability.

Concentrated disadvantage undermines verbal development in numerous ways, Sampson suggests. These include the lack of safe public places to play with others and minimal exposure to academic English.

Economist Greg J. Duncan of Northwestern University in Evanston, Ill., agrees that neighborhood disadvantage worsens the reading skills of black children in Chicago. Yet in 2006, his team reported that—contrary to Sampson's results—6- to 10-year-old black children in families given vouchers to move to better neighborhoods scored higher on reading tests within 4 to 7 years. These results emerged in Chicago and Baltimore but not in three other cities.

Sampson's analysis neglects the possibility that if smarter caretakers move to better neighborhoods, then children who move with them will be brighter—for partly genetic reasons—than those left behind, notes Linda Gottfredson, an education professor at the University of Delaware in Newark. Further research needs to track verbal ability in siblings from the same families, where some are full biological siblings and others half or less, she suggests.

Tuesday, July 22, 2008

ddt

Thirty-five years after the United States banned the pesticide DDT because it was toxic to both humans and the environment, the chemical is still polluting the Antarctic thanks to global warming. http://louisjsheehan.blogstream.com

Antarctica’s Adelie penguins have shown traces of DDT since scientists started tracking the data in the 1970s. But alarmingly, the DDT concentration has remained about the same, even as the world has cut its DDT use by 80 to 90 percent since the 1960s. Although DDT persists in the environment—as famously documented in Rachel Carson’s Silent Spring—its presence should decrease over time unless a new source is leaching DDT into the ecosystem, according to a study led by Heidi Geisz at the College of William and Mary. http://louisjsheehan.blogstream.com And Geisz’s team thinks they’ve figured out what the new source is: Glaciers.

Geisz says that DDT first travels to the Antarctic attached to airborne particles and then falls with snow. In other conditions, traces of the chemical would have gone straight into the food web, with krill eating plankton that have absorbed DDT and penguins then eating the krill. But DDT-carrying snow that falls onto a glacier will instead freeze and become absorbed into the glacier.

Now, as global warming melts Antarctica’s coastal ice sheets, the water carries with it DDT that had been deposited in long-ago snowstorms and trapped inside the glacier, possibly for decades. In their study, Geisz and her team say that DDT was found 6 meters below the surface of the Antarctic Peninsula in 1975, and she estimates that there could be up to 3.6 metric tons of DDT stored in the Antarctic ice sheet. http://louisjsheehan.blogstream.com With global warming worsening, the scientists say, between 1 and 4 kg of DDT will enter the Antarctic ecosystem every year. The Adelies and other creatures will be exposed to high concentrations of DDT, which has been shown to cause thin eggshells in birds. Sorry, penguins: The bad news just keeps on coming.

Wednesday, July 9, 2008

public

May 19, Thursday. The bogus proclamation has been the principal topic to-day. The knowledge that it is a forgery has not quieted the public mind. http://Louis2J2Sheehan2Esquire.US

There seems to be fighting both in front and on the James River, but nothing decisive is accomplished. I feel solicitous in regard to Butler, who, though a man of ability, has not the military knowledge and experience for so large and responsible a command.

Monday, June 30, 2008

babbage

Nineteenth-century British mathematician and engineer Charles Babbage has a host of inventions to his name, including the standard railroad gauge, the cowcatcher and the ophthalmoscope. http://louis-j-sheehaN.NET A famous design he never built is his Difference Engine No. 2, a piece of Victorian technology meant to tussle with logarithms and trigonometry. Working from Babbage’s 1849 plans, Doron D. Swade, a curator at London’s Science Museum, constructed the first working version of it in 1991 [see “Redeeming Charles Babbage’s Mechanical Computer”; SciAm, February 1993], which is on display at the museum. http://louis-j-sheehaN.NETNow Swade has constructed a second engine, unveiled on May 10 for a one-year exhibition at the Computer History Museum in Mountain View, Calif. It consists of 8,000 bronze, cast-iron and steel parts, weighs five tons and measures 11 feet (3.4 meters) long and seven feet (2.1 meters) high.

Friday, June 6, 2008

thyroid Louis J. Sheehan 40001

Dr. Jacob Robbins, whose studies of the thyroid gland at the National Institutes of Health helped explain how it helps govern metabolism and how thyroid cancers caused by radiation may be treated or possibly prevented, died on May 12 in Bethesda, Md. He was 85.

The cause was heart failure, his family said.

With another endocrinologist at the health institutes, Joseph E. Rall, Dr. Robbins embarked on a study of thyroxine, an important hormone produced by the thyroid that helps regulate metabolism. In the 1950s, the two researchers theorized that levels of thyroxine might vary in the bloodstream, but that the level of thyroxine actually in use would often be markedly lower. They found that thyroxine had to be “free,” or not bound to globulin and other plasma proteins, to be effective, whatever the overall thyroxine level in the bloodstream.

The findings of Dr. Robbins and Dr. Rall yielded insights about what are “normal and pathologic states in the thyroid, and how to distinguish between them,” said Dr. Phillip Gorden, an endocrinologist who directed the National Institute of Diabetes and Digestive and Kidney Diseases at the N.I.H. from 1986 to 1999. The observations have also aided physicians and pharmaceutical companies in developing targeted dosages of thyroxine, which in some pregnant women helps prevent or treat hypothyroidism, a hormone deficiency that can cause lasting developmental problems in infants.

In further fruitful collaborations with Dr. Rall and others, Dr. Robbins studied incidences of thyroid cancer in patients exposed to radioactive fallout from nuclear testing. Earlier, in the 1950s, he had examined the therapeutic properties of radioactive iodine when used to pinpoint and treat cancer in the thyroid. In the decades that followed, Dr. Robbins became an authority on the harmful effects of radioactive iodine released spontaneously into the atmosphere.

At the health institutes, Dr. Robbins helped direct long-term studies of the survivors of nuclear tests and accidents, and he followed the health effects of iodine fallout after the Chernobyl reactor meltdown in Ukraine in 1986 and after American weapons testing in the Marshall Islands from the 1940s to the 1980s. He joined a vocal group of scientists who called for wider availability of a drug that can help prevent thyroid cancers from showing up after intense exposures to radiation. That drug, potassium iodide, is taken orally and floods the thyroid with iodine to block the absorption of radioactive iodine.

Dr. Robbins argued that people living near commercial nuclear reactors, particularly children, should have immediate access to potassium iodide. He urged the federal government to stockpile the drug and widen its potential distribution.

In 2001, he told The New York Times, “To me, the smart thing to do would be to have it in homes, in blister packs with adhesive backs.”

Jacob Robbins was born in Yonkers. He studied chemistry at Cornell before earning a medical degree there in 1947. http://louis1j1sheehan.us



Dr. Robbins joined the health institutes as an investigator in 1954. He was chief of the clinical endocrinology branch at the National Institute of Diabetes and Digestive and Kidney Diseases from 1963 to 1991. The health institutes named him a scientist emeritus in 1995.

Dr. Robbins was a president of the American Thyroid Association. From 1968 to 1972, he was editor in chief of the journal Endocrinology. Louis J. Sheehan, Esquire

Dr. Robbins is survived by his wife, the former Jean Adams. The couple lived in Bethesda. He is also survived by a son, Mark, of Seattle; two daughters, Alice of Amherst, Mass., and Susan of Shelburne Falls, Mass.; a brother, Lionel, of Bloomfield Hills, Mich.; a sister, Evelyn Savitzky of Pittsboro, N.C.; and four grandchildren.

thyroid Louis J. Sheehan, Esquire