Beyond the Schoolyard: The Contributions of Parenting Logics, Financial Resources, and Social Institutions to the Social Class Gap in Structured Activity Participation.

We investigate cultural and structural sources of class differences in youth activity participation with interview, survey, and archival data. We find working- and middle-class parents overlap in parenting logics about participation, though differ in one respect: middle-class parents are concerned with customizing children's involvement in activities, while working-class parents are concerned with achieving safety and social mobility for children through participation. Second, because of financial constraints, working-class families rely on social institutions for participation opportunities, but few are available. Schools act as an equalizing institution by offering low-cost activities, allowing working-class children to resemble middle-class youth in school activities, but they remain disadvantaged in out-of-school activities. School influences are complex, however, as they also contribute to class differences by offering different activities to working- and middle-class youth. Findings raise questions about the extent to which differences in participation reflect class culture rather than the objective realities parents face.

THE RELATIONSHIP BETWEEN NEIGHBORHOOD RACIAL CONCENTRATION AND VERBAL ABILITY: AN INVESTIGATION USING THE INSTITUTIONAL RESOURCES MODEL.

Relatively few studies examine the relationship between racial residential segregation and educational or cognitive outcomes. Using data from the National Longitudinal Study of Adolescent Health and the institutional resources model of neighborhood effects, I investigate one account of how macrostructural arrangements between race, neighborhood segregation, and school quality interact to produce inequalities in test scores. Consistent with the institutional resources model, results suggest that school quality varies across neighborhoods based, in part, on their degree of racial concentration. Indeed, school quality and other school characteristics mediate the relationship between racial concentration and verbal skills, particularly among black males. These findings have implications not only for inequalities in cognitive skills among blacks across residential space, but also between blacks and whites given high levels of residential segregation in the United States. In sum, findings illustrate yet another way in which residential segregation contributes to, and not merely reflects, racial inequalities.

Whole-body to tissue concentration ratios for use in biota dose assessments for animals.

Environmental monitoring programs often measure contaminant concentrations in animal tissues consumed by humans (e.g., muscle). By comparison, demonstration of the protection of biota from the potential effects of radionuclides involves a comparison of whole-body doses to radiological dose benchmarks. Consequently, methods for deriving whole-body concentration ratios based on tissue-specific data are required to make best use of the available information. This paper provides a series of look-up tables with whole-body:tissue-specific concentration ratios for non-human biota. Focus was placed on relatively broad animal categories (including molluscs, crustaceans, freshwater fishes, marine fishes, amphibians, reptiles, birds and mammals) and commonly measured tissues (specifically, bone, muscle, liver and kidney). Depending upon organism, whole-body to tissue concentration ratios were derived for between 12 and 47 elements. The whole-body to tissue concentration ratios can be used to estimate whole-body concentrations from tissue-specific measurements. However, we recommend that any given whole-body to tissue concentration ratio should not be used if the value falls between 0.75 and 1.5. Instead, a value of one should be assumed.

Brain integrity and cerebral atrophy in Vietnam combat veterans with and without posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is associated with decreased hippocampal volume, but the relationship between trauma and brain morphology in the absence of PTSD is less clear. In this study, measures of brain integrity were determined by estimating gray and white matter regional brain volumes using structural magnetic resonance imaging in six patients with PTSD and in five controls with comparable trauma exposure but without clinical evidence of PTSD. The only statistically significant volume difference between groups was observed multivariately in the white matter of the right temporal lobe (superior temporal gyrus, fusiform gyrus, parahippocampal gyrus, white-matter stem, middle temporal gyrus, and inferior temporal gyrus), although small sample sizes limit the power to detect between-group differences. Both groups showed heterogeneity in cerebral atrophy.

Preliminary findings of noncompliance with psychotropic medication and prevalence of methamphetamine intoxication associated with suicide completion.

OBJECTIVE: A study of medical examiner records from suicide completers was designed to identify potential precipitating factors in the decision to commit suicide. METHODS: Forensic data has been collected for a subset of suicide victims in Utah who completed suicide between 1996 and 2002. RESULTS: Youth suicide completers appear to be undiagnosed for mental illness, or to be noncompliant with psychotropic medications. Along with treatment issues, alcohol and methamphetamine were the most common substances found in the blood and/or urine of suicide completers. CONCLUSIONS: Accurate diagnosis of mental illness, and improved compliance with psychotropic medications may play a critical role in suicide prevention. The prevalence of methamphetamine in suicide completers is unexpectedly high and requires further investigation.

No evidence for linkage of liability to autism to HOXA1 in a sample from the CPEA network.

A recent study by Ingram et al. [2000b: Teratology 62:393-405] suggests a (His)73(Arg) polymorphism (A:G) in HOXA1 contributes substantially to a liability for autism. Using 68 individuals diagnosed with Autism Spectrum Disorders, they found a significant dearth of G homozygotes and biased transmission of G alleles from parents to affected offspring, especially from mothers. Because the connection between HOXA1 and liability to autism is compelling, we attempted to replicate their finding using a larger, independent sample from the Collaborative Programs of Excellence in Autism (CPEA) network. In our data, genotype frequencies conform to Hardy-Weinberg equilibrium; allele transmissions meet Mendelian expectations; and there is no obvious sex-biased allele transmission. Based on our sample size, calculations suggest that we would have at least 95% power to detect linkage and association even if the A:G polymorphism were to account for only 1% of the heritability of autism. Therefore, although we cannot exclude the possibility that the samples in the two studies are intrinsically different, our data from our sample argue against a major role for HOXA1 (His)73(Arg) in liability to autism.

The Neighborhood Contexts in Which Low-Income Families Navigate Welfare Reform: Evidence from the Three-City Study.

We investigate the neighborhood contexts in which low-income families negotiate the new environment created by welfare reform. Using data from the Three-City Study and U.S. Census, we follow 1,059 low-income women from 1999 to 2005tracking their neighborhood quality, employment, and welfare use. Despite living in similar neighborhoods in 1999, women who left welfare experienced larger reductions in neighborhood disadvantage than women who remained on welfare. Likewise, women who left welfare with employment achieved larger increases in neighborhood quality than those who left welfare without work; the latter experiencing neighborhood change no different than those who stayed on welfare. Results indicate that neighborhood conditions are, at minimum, associated with welfare outcomes. We evaluate whether improvements in residential contexts facilitate transitions to economic self-sufficiency, but also test the reverse possibility. Findings suggest that neighborhood quality increases after women leave welfare, though we cannot reject the possibility that better neighborhoods lead to better outcomes.

Bioenergetics and growth of young-of the-year northern pike (Esox lucius) and burbot (Lota lota) exposed to metal mining effluent.

We hypothesized that exposure to metal mining effluent would reduce the ability of young-of-the-year fishes to accumulate energy reserves to survive the overwinter period (known as "winter stress syndrome") in a Canadian boreal forest watershed. Northern pike (Esox lucius) and burbot (Lota lota) were collected immediately before and after winter from a reference lake and two lakes receiving effluent. Unexpectedly, total body lipid and triglyceride, and liver triglyceride levels were greater in effluent-exposed pike and burbot in both fall and spring. However, there were no lake or season differences in growth indices of length, weight, muscle RNA/DNA ratio, or muscle protein levels in pike. In addition, total lipids and triglycerides in burbot were greater in spring compared to fall, while no seasonal differences were observed in pike, suggesting that burbot continued to feed during winter. Findings do not support the winter stress syndrome hypothesis and suggest possible direct and indirect effects of metal mining effluent on lipid dynamics of juvenile fishes.

Comparison of chloroform-methanol-extracted and solvent-free triglyceride determinations in four fish species.

Lipids, including triglycerides, are important variables in fish bioenergetics and can be used to estimate overall fish condition. Triglycerides are the major energy storage form in fish and therefore are a more ecologically and physiologically relevant measure of bioenergetics than total lipids. Chloroform-methanol-extracted total body lipids (Bligh and Dyer) and total body triglycerides determined in chloroform-methanol extracts and unextracted whole-body fractions were measured in four fish species: northern pike Esox lucius, burbot Lota lota, slimy sculpin Cottus cognatus, and spottail shiners Notropis hudsonius. Determinations of total body lipids were consistently greater than those of total body triglycerides when measured in the same solvent-extracted fraction, although both measures followed similar trends. In an effort to eliminate the need for extraction with organic solvents, we compared the performance of an enzyme-based triglyceride assay in both the solvent-extracted fraction and a whole-body unextracted homogenate for each fish. The chloroform-methanol-extracted triglyceride values were consistently lower than triglycerides measured in the unextracted whole-body homogenate. In addition, comparison of triglyceride measurements revealed limitations to the solvent extraction and subsequent triglyceride determinations in lean fish. Thus, in addition to being simple, rapid, and not requiring organic solvents, determination of triglycerides in an unextracted whole-fish homogenate may be a useful alternative to chloroform-methanol-based methods of lipid extraction and subsequent triglyceride measurement.

Larval deformities associated with selenium accumulation in northern pike (Esox lucius) exposed to metal mining effluent.

The objective of this study was to investigate selenium toxicosis in larval northern pike (Esox lucius) originating from reproductively mature pike collected downstream of a uranium milling operation in northern Saskatchewan, Canada. Eggs were obtained from female pike collected from a reference site and three sites representing an exposure gradient (approximately 2, 10, and 15 km downstream of effluent discharge). Embryos were incubated following a two-way (crossover) analysis of variance experimental design that allowed discrimination between effects due to maternal transfer to eggs and effects due to site water exposure in the developing embryos. The major finding of this study was a significant increase in the frequencies of individual deformities (skeletal curvatures, craniofacial deformities, and fin deformities) and edema in fry originating from high and medium exposure site females (mean selenium concentrations of 48.23 and 31.28 microg/g egg dry weight and 38.27 and 16.58 microg/g muscle dry weight, respectively) compared to reference site females. Selenium concentrations resulting in a 20% increase in total deformities above background levels (EC20S) were 33.55 and 21.54 micro/g dry weight in eggs and muscle, respectively. Mathematical conversion of the egg- and muscle-derived relationships to whole body selenium levels resulted in similar EC20S of 15.56 and 17.72 microg/g dry weight, respectively. These relationships between tissue selenium levels and larval deformities suggest that northern pike are within the same range of sensitivity to selenium as the majority of warm water (e.g., centrarchids and cyprinids) and cold water (e.g., salmonids) fish species studied to date.

Evidence for frontal-subcortical circuit abnormalities in bipolar affective disorder.

Most of the literature on bipolar disorder has focused on abnormalities of neurotransmitters rather than brain circuits. The few discussions of circuits have primarily focused on the limbic system. Evidence is accumulating, however, that basal ganglia-thalamic-cortical reentrant circuits play a major role in the affective, motor and cognitive symptoms of a number of neuropsychiatric conditions including bipolar disorder. In this paper, the authors argue that there is compelling direct and indirect evidence of frontal-subcortical circuit abnormalities in patients with bipolar affective disorder.

Alleles of a reelin CGG repeat do not convey liability to autism in a sample from the CPEA network.

A recent study by Persico et al. [2001: Mol Psychiatry 6:150-159] suggests alleles of a CGG polymorphism, just 5' of the reelin gene (RELN) initiator codon, confer liability for autism, especially alleles bearing 11 or more CGG repeats (long alleles). The association is consistent across both a case-control and family-based sample. We attempted to replicate their finding using a larger, independent family-based sample from the NIH Collaborative Programs of Excellence in Autism (CPEA) Network. In our data, allele transmissions to individuals with autism versus unaffected individuals are unbiased, both when alleles are classified by repeat length and when they are classified into long/short categories. Because of the apparent linkage of autism to chromosome 7q, particularly related to the development of language, we also evaluate the relationship between Reelin alleles and the age at which autism subjects use their first word or first phrase. Neither is significantly associated with Reelin alleles. Our results are not consistent with a major role for Reelin alleles in liability to autism.