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81.
The effects of the pubertal transition on behavior problems and its interaction with family and neighborhood circumstances were examined with a sample of 867 African American children 10-12 years of age. Pubertal development status, pubertal timing, and primary caregivers' parenting behaviors were significantly related to affiliation with deviant peers and externalizing behaviors. Externalizing behavior among early-maturing children was associated positively with primary caregivers' use of harsh-inconsistent discipline and negatively with nurturant-involved parenting practices. Disadvantaged neighborhood conditions were significantly associated with deviant peer affiliation. The effect of pubertal transition varied according to family and neighborhood conditions: Early-maturing children living in disadvantaged neighborhoods were significantly more likely to affiliate with deviant peers. Early-maturing children with harsh and inconsistent parents were significantly more likely to have externalizing problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
Heaving of pavements and a building foundation became progressively worse on a project at Holloman Air Force Base (AFB), N.M. The cause of the heaving was identified as sulfate attack on recycled concrete used as fill and base course below the buildings and pavements. This recycled concrete came from sulfate-resistant airfield Portland concrete pavement that had existed for decades at Holloman AFB without distress. However, severe sulfate exposure conditions, ready availability of water, the more permeable nature of the crushed recycled concrete, less common thaumasite attack, possible soil contamination as a secondary source of alumina, or some combination of these factors allowed sulfate attack to develop in the recycled material even though it had not in the original concrete pavement.  相似文献   
83.
Data from 296 sibling pairs (mean ages 10 and 13 years), their primary caregivers, and census records were used to test the hypothesis that African American children's likelihood of developing conduct problems associated with harsh parenting, a lack of nurturant-involved parenting, and exposure to an older sibling's deviance-prone attitudes and behavior would be amplified among families residing in disadvantaged neighborhoods. A latent construct representing harsh-inconsistent parenting and low levels of nurturant-involved parenting was positively associated with younger siblings' conduct disorder symptoms, as were older siblings' problematic attitudes and behavior. These associations were strongest among families residing in the most disadvantaged neighborhoods. Future research and prevention programs should focus on the specific neighborhood processes associated with increased vulnerability for behavior problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
84.
Effects of early physical maturation and accelerated pubertal changes on symptoms of major depression were examined in 639 African American children. Three rival hypotheses, early timing, off-time, and stressful change, were tested using 2 waves of data (mean ages = 11 and 13 years). The pubertal effect operates differently according to children's gender and age. For girls, early maturation was consistently associated with elevated levels of depressive symptoms. For boys, early maturers manifested elevated levels of depression only at age 11, but these symptoms subsided by age 13. Boys who experienced accelerated pubertal growth over time displayed elevated symptom levels. Results support the early timing hypothesis for girls and the stressful change hypothesis for boys. Time at assessment is critical when examining boys' pubertal transition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
85.
The occurrence and co-occurrence of depressive symptoms and conduct problems were examined in the context of parenting behaviors in a community-based sample of 897 African American children and their primary caregivers using a multi-informant, longitudinal design. Parenting behaviors and clinical symptoms were assessed in 2 waves, when the children averaged 10.5 and 12.3 years of age. Parenting behaviors differed significantly according to a child's symptomatology; (a) that is, when a child exhibited no depressive or conduct problems, (b) depressive problems only, (c) conduct problems only, or (d) co-occurring depressive and conduct problems. When parenting behaviors were examined according to changes in children's symptom levels, children whose symptoms increased over time reported increases in hostility and harsh-inconsistent parenting and decreases in warmth and nurturant-involved parenting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
86.
Hardiness, which is a multidimensional personality trait that is hypothesized to protect people from the effects of stress, has attracted considerable research attention during the last 30 years. The current study provides a meta-analytic review of hardiness. Specifically, we examined the relationships between the hardiness facets, the relationship between hardiness and other personality variables, as well as the relationships between hardiness and several hypothesized criteria, including stressors, strains, social support, coping, and performance. Our analyses generally suggest that hardiness is: (a) positively related to other personality traits that are expected to protect people from stress, (b) negatively related to personality traits that are expected to exacerbate the effects of stress, (c) negatively related to stressors, strains, and regressive coping, and (d) positively related to social support, active coping, and performance. Regression analyses suggest that hardiness is significantly related to important criteria after the effects of other personality traits (e.g., the Five Factor Model traits) are controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
To test the differential susceptibility to parenting hypothesis, a 4-wave, randomized prevention design was used to examine the impact of the Strong African American Families program on past-month substance use across 29 months as a function of DRD4 genotype. Youths (N = 337; M age = 11.65 years) were assigned randomly to treatment condition. Those carrying a 7-repeat allele showed greater differential response to intervention vs. control than those with two 4-repeat alleles. Control youths but not treatment youths with a 7-repeat allele reported increases in past-month substance use across the 29-month study period, but this pattern did not emerge for those with the 4-repeat allele. Supporting the differential susceptibility to parenting hypothesis, the results suggest a greater preventive effect for youths carrying a 7-repeat allele, a role for DRD4 in the escalation of substance use during adolescence, and potential for an enhanced understanding of early-onset substance use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
88.
Rapid Process for Manufacturing Aluminum Nitride Powder   总被引:15,自引:0,他引:15  
A rapid, direct nitridation process for the manufacture of sinterable aluminum nitride (A1N) powder was developed at the pilot scale. Atomized aluminum metal and nitrogen gas were heated and reacted rapidly to synthesize A1N while they passed through the reaction zone of a transport flow reactor. The heated walls of the reactor simultaneously initiated the reaction and removed the generated heat to control the exotherm. Several variations of the process were required to achieve high conversion and reduce wall deposition of the product. The fine A1N powder produced did not require a postreaction grinding step to reduce particle size. However, a secondary heat treatment, following a mild milling step to expose fresh surface, was necessary to ensure complete conversion of the aluminum. In some instances, a final air classification step to remove large particles was necessary to promote densification by pressureless sintering. The A1N powder produced was pressureless sintered with 3 wt% yttria to fabricate fully dense parts which exhibited high thermal conductivity. The powder was shown to be less sinterable than commercially available car-bothermally produced powders.  相似文献   
89.
We discuss serial marriage, defined as three or more marriages as a result of repeated divorce, from a heuristic perspective. We estimate the prevalence of the phenomenon and advance hypotheses based on existing empirical, clinical, and theoretical work concerning the development of this life-style and its consequences for family members. We discuss possible outcomes of children in serial marriage families. We present conceptual and theoretical considerations for the study of serial marriage, as well as suggestions for future research directions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
90.
The reaction of formaldehyde and diamides of 1,2-diamines in acetic acid containing a trace of hydrochloric acid was found to give 1,3-diacyl derivatives of imidazolidine in high yield. The similar reaction of formaldehyde and diamides of 1,3-propylenediamine gave high yields of 1,3-diacylhexahydropyrimidines. Attempts to extend this reaction to other aldehydes than formaldehyde failed, as did attempts to condense formaldehyde with a diamide which would give a four-membered or seven-membered ring system, the diamide being recovered unchanged in each instance. Twenty-two new compounds were prepared and characterized. Presented at the AOCS Meeting, Chicago, September 1970.  相似文献   
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