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.