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891.
892.
A study of deaths due to organophosphate and related "cholinesterase-inhibiting" pesticides was performed on the case files of the office of the Medical Examiner in Metropolitan Dade County in Miami, Florida, USA. Briefly, a comparison was performed between cases which occurred between the years 1961-1965, when such pesticides were used indiscriminately and before stricter laws regulating their use were enacted, and with a series of cases occurring between the years, 1981-85, after such stricter laws were enacted. The occurrence of such deaths dropped dramatically with the decease in organophosphate use. A discussion ensues, along with specific information for the reader, on how the forensic scientist may help ameliorate their environment.  相似文献   
893.
Headspace gas chromatography was used to determine the concentration of ethanol and methanol in blood samples from 519 individuals suspected of drinking and driving in Sweden where the legal alcohol limit is 0.50 mg/g in whole blood (11 mmol/l). The concentration of ethanol in blood ranged from 0.01 to 3.52 mg/g with a mean of 1.83 +/- 0.82 mg/g (+/- S.D.). The frequency distribution was symmetrical about the mean but deviated from normality. A plot of the same data on normal probability paper indicated that it might be composed of two subpopulations (bimodal). The concentration of methanol in the same blood specimens ranged from 1 to 23 mg/l with a mean of 7.3 +/- 3.6 mg/l (+/- S.D.) and this distribution was markedly skew (+). The concentration of ethanol (x) and methanol (y) were positively correlated (r = 0.47, P less than 0.001) and implies that 22% (r2) of the variance in blood-methanol can be attributed to its linear regression on blood-ethanol. The regression equation was y = 3.6 + 2.1 x and the standard error estimate was 0.32 mg/l. This large scatter precludes making reliable estimates of blood-methanol concentration from measurements of blood-ethanol concentration and the regression equation. But higher blood-methanol concentrations are definitely associated with higher blood-ethanol in this sample of Swedish drinking drivers. Frequent exposure to methanol and its toxic products of metabolism, formaldehyde and formic acid, might constitute an additional health risk associated with heavy drinking in predisposed individuals. The determination of methanol in blood of drinking drivers in addition to ethanol could indicate long-standing ethanol intoxication and therefore potential problem drinkers or alcoholics.  相似文献   
894.
The polymorphism of the human vitamin D binding protein (Gc system) was investigated in a total of 149 sera from unrelated healthy Egyptians residing in Tanta City, Gharbiya Governorate, Nile Delta of Egypt, using isoelectric focusing (IEF) in thin-layer polyacrylamide gel followed by immunoblotting. The estimated gene frequencies were Gc1s = 0.540, Gc1f = 0.242 and Gc2 = 0.218.  相似文献   
895.
Research examining factors that predict youth’s involvement in organized activities is very limited, despite associations with positive outcomes. Using data from 1043 youth (49% female; 46.4% Hispanic, 35.4% African American, 14.0% Caucasian, and 4.2% other) from the Project on Human Development in Chicago Neighborhoods, this study examined how characteristics of parents (supervision, warmth) and neighborhoods (perceived neighborhood safety and collective efficacy) predict patterns of adolescents’ involvement in organized activities concurrently (i.e., intensity) and longitudinally (i.e., type and breadth). Parental supervision predicted adolescents’ participation in organized activities across multiple waves. Neighborhood violence was positively associated with concurrent participation in organized activities after controlling for socioeconomic status (SES), whereas higher neighborhood collective efficacy predicted greater breadth in organized activity participation across time. These findings have important implications regarding how to attract and sustain organized activity participation for low-income, urban youth.  相似文献   
896.
Hopelessness is implicated in multiple psychological disorders. Little is known, however, about the trajectory of hopelessness during adolescence or how emergent future orientation may influence its trajectory. Parallel process latent growth curve modelling tested whether (i) trajectories of future orientation and hopelessness and (ii) within-individual change in future orientation and hopelessness were related. The study was comprised of 472 adolescents [52% female, 47% Caucasian, 47% received free lunch] recruited at ages 12–13 who completed measures of future orientation and hopelessness at five annual assessments. The results indicate that a general decline in hopelessness across adolescence occurs quicker for those experiencing faster development of future orientation, when controlling for age, sex, low socio-economic status in addition to stressful life events in childhood and adolescence. Stressful childhood life events were associated with worse future orientation at baseline and negative life events experienced during adolescence were associated with both an increase in the trajectory of hopelessness as well as a decrease in the trajectory of future orientation. This study provides compelling evidence that the development of future orientation during adolescence is associated with a faster decline in hopelessness.  相似文献   
897.
Residential mobility is one documented stressor contributing to higher delinquency and worse educational outcomes. Sensitive period life course models suggest that certain developmental stages make individuals more susceptible to the effects of an exposure, like residential mobility, on outcomes. However, most prior research is observational, and has not examined heterogeneity across age or gender that may inform sensitive periods, even though it may have important implications for the etiology of adolescent development. Moreover, there are important translational implications for identifying the groups most vulnerable to residential mobility to inform how to buffer adverse effects of moving. In this study, low-income families were randomized to residential mobility out of public housing into lower poverty neighborhoods using a rental subsidy voucher (“experimental voucher condition”), and were compared to control families remaining in public housing. The sample was comprised of 2829 youth (51% female; 62% Non-Hispanic Black, 31% Hispanic, 7% other race). At baseline, youth ranged from 5 to 16 years old. This study hypothesized that random assignment to the housing voucher condition would generate harmful effects on delinquency and educational problems, compared to the control group, among boys who were older at baseline. The results confirmed this hypothesis: random assignment to the experimental voucher condition generating residential mobility caused higher delinquency among boys who were 13–16 years old at baseline, compared to same-age, in-place public housing controls. However, residential mobility did not affect delinquency among girls regardless of age, or among boys who were 5–12 years old at baseline. The pattern of results for educational problems was similar but weaker. Families with teenage boys are particularly vulnerable to residential transitions. Incorporating additional supports into housing programs may help low-income, urban families to successfully transition to lower poverty neighborhoods.  相似文献   
898.
Time spent on social media and making online comparisons with others may influence users’ mental health. This study examined links between parental control over the time their child spends on social media, preadolescents’ time spent browsing social media, preadolescents’ appearance comparisons on social media, and preadolescents’ appearance satisfaction, depressive symptoms, and life satisfaction. Preadolescent social media users (N?=?284, 49.1% female; aged 10–12) and one of their parents completed online surveys. Preadolescents, whose parents reported greater control over their child’s time on social media, reported better mental health. This relationship was mediated by preadolescents spending less time browsing and making fewer appearance comparisons on social media. Parental control over time spent on social media may be associated with benefits for mental health among preadolescents.  相似文献   
899.
The goal of the current study was to examine the protective role that maternal media monitoring might have for adolescents. This was done by considering whether styles of media monitoring either directly reduced media use, or whether they buffered the associations between aggressive media use and adolescents’ prosocial behavior, aggression, and delinquency. Participants were 681 adolescents from two cities in the United States (51% female; 73% white), and their mothers, who provided data at two different time points, 2 years apart (when adolescents were roughly ages 13 and 15). Mixture modeling results revealed that mothers used four different styles of media monitoring made up of combinations of active and restrictive monitoring as well as forms of co-use. Styles that included active monitoring and connective co-use (i.e., engaging in media with the intent to connect with children) were directly associated with less media use, and moderated links between adolescents’ media use and behavioral outcomes concurrently but not longitudinally. The discussion was focused on the strength of considering multiple strategies of media monitoring together, and how this approach can inform future research in the area of parental media monitoring.  相似文献   
900.
Adolescent self-regulation is increasingly seen as an important predictor of sexual risk-taking behaviors, but little is understood about how changes in self-regulation affect later sexual risk-taking. Family financial stress may affect the development of self-regulation and later engagement in sexual risk-taking. We examined whether family financial stress influences self-regulation in early adolescence (age 13) and growth in self-regulation throughout adolescence (from age 13–17 years). We then assessed the effects of family financial stress, baseline self-regulation, and the development of self-regulation on adolescent sexual risk-taking behaviors at age 18 years. Using a curve-of-factors model, we examined these relationships in a 6-year longitudinal study of 470 adolescents (52% female) and their parents from a large northwestern city in the United States. Results indicated that family financial stress was negatively associated with baseline self-regulation but not with growth in self-regulation throughout adolescence. Both baseline self-regulation and growth in self-regulation were predictive of decreased likelihood of engaging in sexual risk-taking. Family financial stress was not predictive of later sexual risk-taking. Intervening to support the development of self-regulation in adolescence may be especially protective against later sexual risk-taking.  相似文献   
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