Relation between depressive symptoms and stressful life events in a sample of disadvantaged mothers.

The bidirectional relation between life events and self-reported depression was examined across a 1-year period. With Time 1 depression controlled, Time 2 stress accounted for an additional 10% of Time 2 depressive symptoms. Health-related stress, family violence, and financial stress at Time 2 predicted Time 2 depression after control for Time 1 depression. With Time 1 stress controlled, Time 2 depression accounted for 8% of the variance in Time 2 stress. Time 2 depression predicted Time 2 health-related stress, financial stress, household changes, spouse–partner stress, family violence stress, and substance abuse stress, controlling for each of these stressors at Time 1. The results describe a complex relation between stress and depression and suggest that the relation between stress and depression is moderated by the type of stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult attachment classification and self-reported psychiatric symptomatology as assessed by the Minnesota Multiphasic Personality Inventory--2.

This study examined differences in self-reported psychiatric symptomatology on the Minnesota Multiphasic Personality Inventory-2 according to adult attachment status on the Adult Attachment Interview in first-time mothers from a high-risk poverty sample. Participants reported fairly high levels of symptomatology regardless of attachment status. The dismissing adult attachment group reported comparatively little psychiatric distress, emphasized independence, and scored the lowest on self-reported anxiety. The preoccupied group was highest on a range of indices of psychiatric symptoms indicative of self-perceived distress and relationship problems. The autonomous group's scores ranged between the scores of the other 2 groups on most scales. These different symptom patterns are consistent with adult attachment status as an index of self-representation and as a set of strategies for processing emotions and thoughts related to distress and to attachment relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Does Class Size in First Grade Relate to Children's Academic and Social Performance or Observed Classroom Processes?

This study evaluated the extent to which first-grade class size predicted child outcomes and observed classroom processes for 651 children (in separate classrooms). Analyses examined observed child-adult ratios and teacher-reported class sizes. Smaller classrooms showed higher quality instructional and emotional support, although children were somewhat less likely to be engaged. Teachers in smaller classes rated typical children in those classes as more socially skilled and as showing less externalizing behavior and reported more closeness toward them. Children in smaller classes performed better on literacy skills. Larger classrooms showed more group activities directed by the teacher, teachers and children interacted more often, and children were more often engaged. Lower class sizes were not of more benefit (or harm) as a function of the child's family income. First-grade class size in the range typical of present-day classrooms in the United States predicts classroom social and instructional processes as well as relative changes in social and literacy outcomes from kindergarten to first grade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Practical Formulas for the Dimensioning of Air Valves

On the basis of theoretical considerations, the technical note presents two practical formulas for the dimensioning of air valves when filling a pipe with water. One is to be used for designing air valves on the basis of the maximum allowed water hammer overpressures; the other when the maximum in pipe water velocity is set. The reliability of these formulas was tested with a numerical model based on the same hypothesis, which was in turn verified with experimental tests.     

Specialization and size of scientific activities: A bibliometric analysis of advanced countries

The relationship between the size of national scientific activities of advanced countries and the degree of specialization by fields of science is examined using bibliometric indicators of the number of papers and of paper citations. A negative relation between the amount of scientific activity and the degree of scientific specialization has emerged, with Japan and, to a lesser extent Italy, showing a specialization degree higher than expected. Countries with established scientific traditions (such as the US, the UK, the Netherlands, and Switzerland) have a lower than expected specialization degree, suggesting a more diversified range of research activities. Over time, however, most countries have reduced their scientific specialization, a pattern which is in contrast with recent research on patents and technological specialization.Rotating first authorship. This paper is part of a research on the Scientific and Technological Specialization of advanced countries jointly financed by the Commission of European Communities, D.G. XII, Science, Research and Development, Service Research Evaluation, and the Italian National Research Council. We are grateful to PatriziaPrincipessa and RobertoSimonetti for research assistance.     

Molecular features of sulfonic acids used for synthesis of overbased detergent additives

Overbased calcium sulfonates are used in many modern oil formulations to provide cleaning action and to neutralize the organic acids formed during combustion, preventing corrosion. The performance of detergents is related to their molecular structure, which is generally known only as a chemical category. In the present work, nuclear magnetic resonance (NMR) spectroscopy and electrospray ionization mass spectrometry are used to analyze the molecular structure of three alkyl‐benzene sulfonic acids in detail. Some important molecular features were obtained by elaborating the NMR signal intensities, such as the number and positions of alkyl substituents on the benzene ring, the distribution of alkyl chain lengths and the mole fraction of 1‐phenyl isomers (synthesized by alkylation of benzene with α‐olefin). Ion‐trap mass spectrometry is used to obtain the mass spectrometry/mass spectrometry (MS²) spectra of the principal molecular ions. By choosing suitable molecular ions, MS² spectra can ascertain the presence of different substituted benzene isomers within a mixture because the MS² spectra show specific fragments due to the number of alkyl substituents on the aromatic ring. Copyright © 2006 John Wiley & Sons, Ltd.     

Instruction, teacher–student relations, and math achievement trajectories in elementary school.

Children enter elementary school with widely different skill levels in core subjects. Whether because of differences in aptitude or in preparedness, these initial skill differences often translate into systematic disparities in achievement over time. How can teachers reduce these disparities? Three possibilities are to offer basic skills training, to expose students to higher order instruction, or to provide socioemotional support. Repeated measures analyses of longitudinal data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Study of Early Child Care and Youth Development revealed that children with low, average, or high math skills prior to elementary school followed different but parallel trajectories of math achievement up through fifth grade. When enrolled in classes with inference-based instruction, however, the initially least skilled children narrowed the achievement gap as long as they did not have conflictual relations with their teachers. They did not make this kind of progress if they were in classes focused exclusively on basic skills instruction or if they were in inference-focused classes but had conflictual relations with teachers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluating the Effectiveness of a Software-Based Technique Under SEEs Using FPGA-Based Fault Injection Approach

Nowadays, microprocessor-based system??s robustness under Single Event Effects (SEEs) represents a very important concern. A widely adopted solution to make a microprocessor-based system robust consists in modifying the application code by adding redundancy and fault tolerance capabilities. In this context, the main idea behind this paper is to evaluate a software-based technique named Optimized Embedded Signature Monitoring (OESM) using an FPGA-based fault injection technique, which is able to inject a high number of Single Event Upsets (SEUs) and Single Event Transients (SETs) in a short period of time. The obtained results demonstrated not only the increase of system??s robustness level, but also point out the remaining weak areas in the microprocessor-based system with respect to both types of SEEs.     

Teachers' perceptions of their relationships with students: Effects of child age, gender, and ethnicity of teachers and children.

This study assessed the extent to which teachers' perceptions of their relationships with young students varied as a function of child and teacher characteristics in a large, demographically diverse sample of 197 preschool and kindergarten teachers and 840 children (mean age 4 yrs 7 mo old). Children were approximately evenly divided between boys and girls. Regression analyses were conducted to examine the relation between teachers' perceptions of their relationships with students and (a) teacher ethnicity, (b) child age, ethnicity, and gender, and (c) the ethnic match between teacher and child. Child age and ethnicity and teacher–child ethnic match were consistently related to teachers perceptions, explaining up to 27% of the variance in perceptions of negative aspects of the teacher–child relationship, specifically teacher–child conflict. When child and teacher had the same ethnicity, teachers rated their relationships with children more positively. The results are discussed in terms of classroom social processes related to children's adjustment and the measurement of teacher–child relationships. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Early behavioral associations of achievement trajectories.

Duncan et al. (2007) examined associations between early behavioral and cognitive skills with later achievement. These associations were examined in 6 different data sets and results converged to suggest that early behavioral competences or problems had little, if any, prediction to later achievement and that attentional competences had small positive relations with later achievement. In contrast, cognitive abilities were by far the strongest predictors of achievement. We provide and investigate potential reasons why Duncan et al. found little to no association between behavior and later achievement in a reanalysis of data from 3 studies previously analyzed by Duncan et al. Potential reasons include the validity of the behavioral measures, treatment of the behavioral measures as continuous as opposed to categorical, and the choice of data analytic method. In this article, we discuss these issues at greater length and address them in our reanalysis. We also bring into question the nature of the relationship between behavior and achievement. Generally, our reanalysis supports the idea that attention measures are more predictive than behavioral measures; however, certain behavior measures showed small to moderate associations to concurrent levels of academic achievement and changes in academic achievement through elementary school. (PsycINFO Database Record (c) 2010 APA, all rights reserved)