A latent class analysis of maternal depressive symptoms over 12 years and offspring adjustment in adolescence.

The authors used data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development to model patterns of maternal depressive symptoms, from the period of infants’ age 1 month to adolescence (age 12 years), and then examined adolescent adjustment at age 15 years as a function of the course and severity of maternal symptoms. The authors identified 5 latent classes of symptoms in 1,357 women, while also taking into account sociodemographic measures: never depressed, stable subclinical, early decreasing, moderately elevated, and chronic. Women with few symptoms were more likely to be married, better educated, and in better physical health than were women with more elevated symptoms. At age 15 years, adolescents whose mothers were in the chronic, elevated, and stable subclinical latent classes reported more internalizing and externalizing problems and acknowledged engaging in more risky behavior than did children of never depressed mothers. Latent class differences in self-reported loneliness and dysphoria were also found. Discussion focuses on adolescent adjustment, especially among offspring whose mothers reported stable symptoms of depression across their childhoods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Porteus maze performance following traumatic brain injury in children.

To investigate planning in traumatically brain injured children, the authors gave the Porteus Maze Test (PMT; S. D. Porteus, 1959) to 276 pediatric patients who had sustained a traumatic brain injury (TBI) at least 3 years previously. Sensitivity of the PMT to TBI severity, age at test, and volume of focal brain lesions detected by magnetic resonance imaging was also studied. The Peabody Picture Vocabulary Test-Revised (L. M. Dunn & L. M. Dunn, 1981) was also administered as a control measure. Results indicated that the PMT was highly sensitive to TBI severity and to volume of circumscribed prefrontal lesions. In contrast to the PMT data, receptive vocabulary was related to injury severity but not to discrete prefrontal lesions. Implications for mechanisms of cognitive deficit after TBI in children are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors influencing service utilization and mood symptom severity in children with mood disorders: Effects of multifamily psychoeducation groups (MFPGs).

This study investigated the impact of psychoeducation on service utilization and mood symptom severity in children with mood disorders. Parents’ knowledge of mood disorders, beliefs about treatment, and perceptions of children’s need for treatment were hypothesized to mediate the relationship between psychoeducation and service utilization and between psychoeducation and mood symptom severity. Linear mixed effects modeling and joint significance test for mediation were used in secondary data analyses of the multifamily psychoeducation group (MFPG) study, a randomized controlled trial of 165 children ages 8 to 12 years with mood disorders. A majority of those sampled were male (73%) and White, non-Hispanic (90%), and the median range of family income was $40,000–$59,000. Participation in MFPG significantly improved quality of services utilized, mediated by parents’ beliefs about treatment. Participation in MFPG also significantly improved severity of child’s mood symptoms, mediated by quality of services utilized. MFPG appears to be a psychoeducational intervention that helps parents to become better consumers of the mental health system who access higher quality services. Children’s symptom severity decreases as a result. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A model of seam pucker and its applications Part I: theoretical

Abstract

This article considers a simple model of the lock stitch (301) seam, and uses it to derive a measure of the severity of puckering in the seam. The numerical value of the measure depends on the bending properties of the fabrics and thread in the seam, together with the tensions in the threads. How the latter may be estimated is discussed.     

Forming severity concept for predicting sheet necking under complex loading histories

A new method of predicting neck formation in sheets under non-proportional loading is proposed, based on the concept of “cumulative forming severity”. This concept is borrowed from a macroscopic model of ductile fracture where the crack initiation is governed by the accumulated equivalent plastic strain modified by the stress triaxiality and the Lode angle parameter. Such an approach necessitates a representation of the forming limit diagram (FLD) in the space of the equivalent strain to neck and the Lode angle parameter.Another new factor is the assumption of the non-linear accumulation of forming severity for non-proportional and complex loading histories. A class of non-linear weighting function is proposed with only one free parameter. A starting point in the derivation is the known FLD corresponding to proportional loading. This can be determined from Hill's and Stören and Rice analytical solutions, from numerical simulation, or else taken directly from experiments. In the case of proportional loading, necking depends on the final state of stress or strain, so it does not matter if necking severity index is accumulated in a linear or non-linear way. For non-proportional loading, the unknown free parameter of the non-linear accumulation rule must be determined from a test.Experimental data on FLDs under complex strain paths for two types of material, aluminum alloy 6111-T4 [Graf A, Hosford W. The influence of strain-path changes on forming limit diagrams of A1 6111 T4. International Journal of Mechanical Sciences 1994;36(10):897–910.] and aluminum-killed sheet steel [Muschenborn W, Sonne HM. Influence of the strain path on the forming limits of sheet metal. Archiv fur das Eisenhuttenwesen 1975;46:597–602], found in the literature are revisited by the proposed model. Calibrated from only one test with non-proportional loading condition, the model is able to predict the remaining tests of complex loading paths with good accuracy.     

浅议PFMEA在实际生产中的有效运用

介绍了过程潜在失效模式及后果分析(PFMEA,Process Potential Failure Mode and Effects Analysis)技术,说明了PFMEA与控制计划及标准化操作之间的关系,结合发动机制造工艺的具体应用实例,阐述了运用PFMEA使之成为动态文件并指导实际问题解决的方法.     

基于TMS320C6713 DSP的IEC电压闪变仪

为实现电压闪变的精确测量,按照国际电工委员会（IEC）推荐的电压闪变仪功能和设计规范,在TMS320C6713数字信号处理器（DSP）平台上设计了采样率为400 Hz的IEC电压闪变仪,并按照IEC给出的电压闪变仪的校验标准,采用多个矩形波动信号进行了闪变值的校验,分析了电网谐波和白噪声对IEC电压闪变仪计算结果的影响,最后,针对白噪声干扰问题,提出了小波阈值去噪的方法,对输入信号进行去噪,校验结果表明基于TMS320C6713 DSP的IEC电压闪变仪测量结果较为准确。研究结果表明电网白噪声对闪变仪的精度干扰较大,电网谐波几乎无影响;经小波阈值去噪后,电压闪变仪的测量精度得到了显著提高。     

The impact fracture behavior of aluminum alloy 2024-T351: Influence of notch severity

In this paper, the interactive influences of notch severity and test temperature on the impact properties and fracture behavior of a Al-Cu-Mg alloy 2024 in the T351 microstructural condition is presented and discussed. Notch angles of 45, 60, 75, and 90° were chosen for a standard Charpy impact test specimen containing two notches. For a given angle of the notch, an increase in dynamic fracture toughness, with test temperature, is most significant for the least severe of the notches, i.e., 45°. At a given test temperature, the impact toughness decreased with an increase in notch severity. An increase in notch severity resulted in Mode I dominated failure at all test temperatures. The influence of localized mixed-mode loading is minimal for the alloy in the T351 microstructural condition. The impact fracture behavior of the alloy is rationalized in light of alloy microstructure, mechanisms governing fracture, and the deformation field ahead of the propagating crack.     

基于大气环境质量的电网绝缘污秽等级划分

通过测试户外挂网绝缘子表面自然积污量及实时监测湖南省各地市近年大气环境污染物主要因子(SO2,NO2,PM10)排放状况,建立了基于大气环境质量的输电线路绝缘子等值盐密、灰密的线性理论模型,并依据该模型对湖南电网绝缘污秽等级进行划分。结果表明,大气环境质量与绝缘子等值盐密、灰密之间具有较好的相关性,可通过对区域大气环境的实时监测,来实现对电网污秽等级的划分和动态调整。     

Measuring the severity of transboundary freshwater conflict: structural vs. behavioural indices in Africa

In the global crisis over access to clean, adequate freshwater, Africa is a special case. Not only are many African states under severe water stress, but the continent is one of the most hydrologically interconnected regions on the planet. With 113 rivers, lakes and aquifers that cross an international border, over 60% of Africa’s territory falls into a transboundary watershed. Africa’s hydrology is interdependent, and mass poverty and political volatility heighten the risk of conflict over freshwater resources. This paper compares two approaches to understanding the severity of transboundary freshwater conflict; one based in behavior and the other based on structural factors unique to each water resource and its users. The goal is to identify Africa’s water hot spots, or those areas where violence over water resources is most likely. The broader aim is to better understand how the way we measure severity affects our understanding of freshwater conflict, and how policy-makers might best approach water politics in Africa.