The student population of America's suburban public schools has shot up by 3.4 million in the past decade and a half, and virtually all of this increase (99%) has been due to the enrollment of new Latino, black and Asian students, according to an analysis of public school data by the Pew Hispanic Center, a project of the Pew Research Center. Once a largely white enclave, suburban school districts in 2006-07 educated a student population that was 41.4% non-white, up from 28% in 1993-94 and not much different from the 43.7% non-white share of the nation's overall public school student population. At the same time, suburban school districts have been gaining "market share"; they educated 38% of the nation's public school students in 2006-07, up from 35% in 1993-94.
Despite the sharp rise in the racial and ethnic diversity of suburban district enrollments overall, there has been only a modest increase in the racial and ethnic diversity of student populations at the level of the individual suburban school. For example, in 2006-07, the typical white suburban student attended a school whose student body was 75% white; in 1993-94, this same figure had been 83%. So at a time when the white share of student enrollment in suburban school districts was falling by 13 percentage points (from 72% in 1993-94 to 59% in 2006-07), the exposure of the typical white suburban student to minority students in his or her own school was growing by a little more than half that much-or 8 percentage points.
When it comes to increases in public school student enrollment, the suburbs are where most of the action has been over the past decade and a half. In 1993-94, city school districts educated a majority of the nation's minority students. That is no longer the case. The movement out of city schools has nearly exclusively been suburban school districts' gain.
The movement of minority students into suburban schools has had the overall effect of slightly reducing levels of ethnic and racial segregation throughout the nation's 93,430 public schools. Minority students on average are less segregated in suburban school districts compared with city school districts, so the shift toward suburban school districts tends to reduce national segregation levels.
The report also examines the changes since 1993-94 in individual suburban school districts. It lists the suburban school districts that have had the fastest growth in minority enrollment, as well as those with the highest levels of racial/ethnic segregation.
These findings are based on an analysis of the most recent available enrollment figures for the nation's public schools. The National Center for Education Statistics of the U.S. Department of Education collects this information and also classifies school districts as being suburban, city or town/rural districts.
Complete report:
http://pewhispanic.org/files/reports/105.pdf
Einstein scientists propose new theory of autism
Symptoms of the disorder may be reversible: Fever may hold clues
Scientists at Albert Einstein College of Medicine of Yeshiva University have proposed a sweeping new theory of autism that suggests that the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible.
The central tenet of the theory, published in the March issue of Brain Research Reviews, is that autism is a developmental disorder caused by impaired regulation of the locus coeruleus, a bundle of neurons in the brain stem that processes sensory signals from all areas of the body.
The new theory stems from decades of anecdotal observations that some autistic children seem to improve when they have a fever, only to regress when the fever ebbs. A 2007 study in the journal Pediatrics took a more rigorous look at fever and autism, observing autistic children during and after fever episodes and comparing their behavior with autistic children who didn't have fevers. This study documented that autistic children experience behavior changes during fever.
"On a positive note, we are talking about a brain region that is not irrevocably altered. It gives us hope that, with novel therapies, we will eventually be able to help people with autism," says theory co-author Mark F. Mehler, M.D., chairman of neurology and director of the Institute for Brain Disorders and Neural Regeneration at Einstein.
Autism is a complex developmental disability that affects a person's ability to communicate and interact with others. It usually appears during the first three years of life. Autism is called a "spectrum disorder" since it affects individuals differently and to varying degrees. It is estimated that one in every 150 American children has some degree of autism.
Einstein researchers contend that scientific evidence directly points to the locus coeruleus–noradrenergic (LC-NA) system as being involved in autism. "The LC-NA system is the only brain system involved both in producing fever and controlling behavior," says co-author Dominick P. Purpura, M.D., dean emeritus and distinguished professor of neuroscience at Einstein.
The locus coeruleus has widespread connections to brain regions that process sensory information. It secretes most of the brain's noradrenaline, a neurotransmitter that plays a key role in arousal mechanisms, such as the "fight or flight" response. It is also involved in a variety of complex behaviors, such as attentional focusing (the ability to concentrate attention on environmental cues relevant to the task in hand, or to switch attention from one task to another). Poor attentional focusing is a defining characteristic of autism.
"What is unique about the locus coeruleus is that it activates almost all higher-order brain centers that are involved in complex cognitive tasks," says Dr. Mehler.
Drs. Purpura and Mehler hypothesize that in autism, the LC-NA system is dysregulated by the interplay of environment, genetic, and epigenetic factors (chemical substances both within as well as outside the genome that regulate the expression of genes). They believe that stress plays a central role in dysregulation of the LC-NA system, especially in the latter stages of prenatal development when the fetal brain is particularly vulnerable.
As evidence, the researchers point to a 2008 study, published in the Journal of Autism and Developmental Disorders, that found a higher incidence of autism among children whose mothers had been exposed to hurricanes and tropical storms during pregnancy. Maternal exposure to severe storms at mid-gestation resulted in the highest prevalence of autism.
Drs. Purpura and Mehler believe that, in autistic children, fever stimulates the LC-NA system, temporarily restoring its normal regulatory function. "This could not happen if autism was caused by a lesion or some structural abnormality of the brain," says Dr. Purpura.
"This gives us hope that we will eventually be able to do something for people with autism," he adds.
The researchers do not advocate fever therapy (fever induced by artificial means), which would be an overly broad, and perhaps even dangerous, remedy. Instead, they say, the future of autism treatment probably lies in drugs that selectively target certain types of noradrenergic brain receptors or, more likely, in epigenetic therapies targeting genes of the LC-NA system.
"If the locus coeruleus is impaired in autism, it is probably because tens or hundreds, maybe even thousands, of genes are dysregulated in subtle and complex ways," says Dr. Mehler. "The only way you can reverse this process is with epigenetic therapies, which, we are beginning to learn, have the ability to coordinate very large integrated gene networks."
"The message here is one of hope but also one of caution," Dr. Mehler adds. "You can't take a complex neuropsychiatric disease that has escaped our understanding for 50 years and in one fell swoop have a therapy that is going to reverse it — that's folly. On the other hand, we now have clues to the neurobiology, the genetics, and the epigenetics of autism. To move forward, we need to invest more money in basic science to look at the genome and the epigenome in a more focused way."
Serious Vision Problems in Urban Preschoolers
In what is believed to be the first comprehensive eye disease study among urban pre-schoolers, Johns Hopkins investigators report that while vision problems are rare, they are more common than once thought. Also, they say, a small group of children with easily treatable visions problems go untreated, while others get treatments they don't need.
Writing in the April issue of the journal Ophthalmology, investigators from the Johns Hopkins Children's Center and the Johns Hopkins Bloomberg School of Public Health say 5 percent of the nearly 2,300 Baltimore area children who were followed in the study, had refractive errors-a defect in the eye's ability to focus light-significant enough to require treatment, but only 1 percent actually were treated. Among 29 children who had a prescription for eyeglasses before entering the study, more than one-third didn't need eyeglasses.
Undetected and untreated, refractive errors can cause loss of visual acuity and eventually lead to amblyopia (lazy eye) and strabismus (crossed eyes), which are hard or impossible to reverse after age 7.
In the study, more than half of the 1,268 black children (55 percent) had some refractive errors as did half (51 percent) of the 1,030 white children. Because overall, one in 20 children studied had a problem that is easily treated, the researchers suggest that pediatricians screen routinely during physicals and parents should insist on screening by age 4.
"The good news is that serious eye disease in preschoolers appears to be uncommon, but the bad news is that we're missing kids who need treatment and treating some children who don't need it," says investigator Michael X. Repka, M.D., deputy director of ophthalmology at Hopkins Children's.
A surprising additional finding in the report is that contrary to previous research suggesting that most infants will outgrow their farsightedness in the first few years of life, few children in the Baltimore study did outgrow it during their preschool years, making early diagnosis and treatment critical, says lead investigator David Friedman, M.D., Ph.D., of the Johns Hopkins School of Medicine and the Bloomberg School of Public Health.
Hyperopia, or farsightedness, was the most common abnormality, occurring more often in white children (40 percent of 1,030) than in black children (31 percent of 1,268).
Anisometropia, a condition marked by a difference in vision between the two eyes, was more common in black children (18 percent) than in white children (11 percent). Black children also had more nearsightedness (6 percent) compared to 0 percent among white children.
Other findings:
- Only 3 percent of all children in the study had severe farsightedness, while only 0.6 percent had severe near-sightedness.
- Only 1 percent of black children and 1.5 percent of white children had a difference in vision between the two eyes (anisometropia) that required treatment.
- Fewer than 3 percent of children had serious astigmatism, an optical defect that can cause lazy eye, blurred vision, headaches, eye strain and fatigue.
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