Transient response of a microstrip line circuit excited by anexternal electromagnetic source

The transient voltages and currents induced by an external electromagnetic field along a microstrip line interconnecting active and/or passive components are studied by using a distributed-source transmission-line model. The influence of the angle of incidence as well as that of the microstrip geometrical and electrical parameters on the line response is analyzed. The instantaneous voltage and power induced on the loads by various types of pulse excitations are computed. Numerical results are obtained both for dispersive and nondispersive lines. A line feeding a transistor microwave amplifier is also considered. The results show the effects of the multiple reflections of the field inside the dielectric substrate and of the signal at the ends of the line. Indications of how to reduce the coupling between the external field and the considered structure are given     

Transient emission from microstrip interconnects: theoreticalformulation and CAD modeling

A hybrid technique suitable for the space-time analysis of the transient spurious emission from microstrip interconnects is presented. The proposed technique requires the preliminary evaluation of the surface current excited on the microstrip interconnecting lines by means of a transmission line model accounting for dispersive effects. The radiated field is then computed in the frequency domain by applying the saddle-point asymptotic technique to the integral expression of the electric field involving the dyadic Green's function. The transient signals excited along the interconnects, and the corresponding radiated field, are finally determined by using the IFFT. Radiation mechanisms are investigated, and the influence of the structure's electrical and geometrical parameters is discussed     

Predictors of Resilience in Maltreated and Nonmaltreated Latino Children.

To date, few studies have sought to investigate the effects of child maltreatment and processes influencing maladaptation and resilience in Latino children. In the current investigation, multiple aspects of functioning, personal resources, and relationship features were examined in school-age maltreated and nonmaltreated Latino children. Maltreated Latino children were found to have fewer areas of resilient functioning. Ego-resiliency and ego-control, as personal resources, and the ability to form a positive relationship with an adult figure outside of the immediate family predicted resilience. However, certain aspects of interpersonal functioning were differentially related to resilience for maltreated and nonmaltreated Latino children. These findings have implications for understanding how resilience can be promoted in maltreated and nonmaltreated Latino children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal depressive disorder and contextual risk: contributions to the development of attachment insecurity and behavior problems in toddlerhood

Research has shown that offspring of depressed caregivers are at increased risk for maladaptive development and emotional difficulties. Specifically, infants and toddlers of depressed mothers have been shown to evidence higher percentages of insecure attachments and more behavioral difficulties than offspring of nondisordered mothers. However, even in studies that reveal significant differences between children of depressed and nondepressed caregivers, a substantial number of children with depressed caregivers do not evidence dysfunction. Such findings have resulted in increased attention to the broader social context in which children of depressed mothers develop. This investigation examined the direct influences of maternal depression on child development, as well as the role of contextual risks that may be particularly heightened in families with depressed parents. Toddlers with depressed mothers evidenced significantly more insecure attachments than did toddlers with nondisordered mothers, and this difference was not accounted for by contextual risk. In predicting child behavior problems, contextual risk was found to mediate the relation between maternal depression and child behavior problems. Father-report data on child behavior corroborated the mother report data. Results are discussed in terms of the diversity of functioning in offspring of depressed caregivers that can be attributed to varied levels of contextual risk accompanying depression.     

An ecological-transactional analysis of children and contexts: the longitudinal interplay among child maltreatment, community violence, and children's symptomatology

Cicchetti and Lynch have conceptualized ecological contexts as consisting of nested levels with varying degrees of proximity to the individual. These levels of the environment interact and transact with each other over time in shaping individual development and adaptation. With a sample of maltreated (n = 188) and nonmaltreated (n = 134) children between the ages of 7 and 12 years, this investigation employed a 1-year longitudinal design to conduct an ecological-transactional analysis of the mutual relationships among community violence, child maltreatment, and children's functioning over time. Indicators of children's functioning were externalizing and internalizing behavior problems and self-rated traumatic stress reactions, depressive symptomatology, and self-esteem. Either full or partial support was obtained for the study's primary hypotheses. Rates of maltreatment, particularly physical abuse, were related to levels of child-reported violence in the community. In addition, child maltreatment and exposure to community violence were related to different aspects of children's functioning. Specific effects were observed for neglect and sexual abuse and for witnessing and being victimized by violence in the community. Finally, there was evidence that children and their contexts mutually influence each other over time. Results were discussed within the framework of an ecological-transactional model of development.     

Inverse expression pattern of REST and synapsin I in human neuroblastoma cells

The zinc finger protein REST is a repressor of neuronal genes in nonneuronal tissues. We have analyzed the expression of REST, together with the expression of a REST target gene, encoding synapsin I, in human neuroblastoma cells. It was found that REST and synapsin I are coexpressed in neuroblastoma cell lines, although the expression of REST was inversely proportional to the levels of synapsin I mRNA. Thus, increased expression of synapsin I was directly correlated with decreased expression of REST. These expression data are in excellent correlation with synapsin I promoter activity measured in neuroblastoma cells showing that an increase in the REST concentration switched off synapsin I promoter activity. We conclude that the concentration of REST determines the expression level of neuronal genes such as the synapsin I gene.     

Emotion regulation among school-age children: The development and validation of a new criterion Q-sort scale.

To foster the study of emotion regulation beyond infancy and toddlerhood, a new criterion Q-sort was constructed. In Study 1, Q-scales for emotion regulation and autonomy were developed, and analyses supported their discriminant validity. Study 2 further explored the construct validity of the Emotion Regulation Q-Scale within a sample of 143 maltreated and 80 impoverished children, aged 6 to 12 years. A multitrait-multimethod matrix and confirmatory factor analyses indicated impressive convergence among the Emotion Regulation Q-Scale and established measures of affect regulation. This new scale also was discriminable from measures of related constructs, including Q-sort assessments of ego resiliency. The use of this new measure was further supported by its ability to distinguish between maltreated and comparison children and between groups of well-regulated versus dysregulated children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of depression in children and adolescents.

In recent decades, research on child and adolescent depression has proliferated. Currently, attention in the field is directed toward examining the epidemiology, causes, course, sequelae, and treatment response of children at risk for developing or presently experiencing depressive disorders. In this article, a developmental psychopathology approach is used to elucidate the development of depressive disorders, the diverse pathways that evolve, and the processes that contribute to varied outcomes. The developmental psychopathology perspective underscores the importance of moving beyond the identification of isolated aberrations in psychological and biological components of depressive presentations to the understanding of how those components have evolved and how they are integrated within and transact across biological, psychological, and social systems. Implications for prevention and intervention are addressed as is the importance of increasing the public awareness of depressive disorders and reducing the social stigma that interfere with the attainment of treatment for depressed persons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chemical phenotype of calretinin interneurons in the human striatum

We recently reported the existence of a new class of aspiny interneurons characterized by their immunoreactivity for the calcium-binding protein calretinin (CR) in human striatum. This group is composed of numerous medium-sized (10-20 microm) neurons with poorly branched dendrites and a smaller number of large-sized (24-42 microm) neurons with highly ramified dendrites. We further demonstrated the selective sparing of the medium-sized, but not all the large-sized, CR+ striatal neurons in Huntington's disease. In the present study, we applied a double-antigen localization method to postmortem striatal tissue obtained from normal individuals to further characterize the chemical phenotype of these two subsets of CR+ neurons. Our results reveal that in the medium-sized neurons, CR is not colocalized with any of the following current markers of striatal neurons: calbindin, parvalbumin, beta-nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d), or choline acetyltransferase (ChAT). Furthermore, quantitative estimates show that the medium-sized CR+ neurons are by far the most abundant type of interneurons in the human striatum. In contrast, CR is colocalized with ChAT in about 80% of the large-sized CR+ neurons. Thus, the medium-sized CR+ neurons appear to form a distinct class of striatal interneurons, whereas most of the large-sized CR+ neurons belong to the population of giant cholinergic neurons. This study has provided the first exhaustive characterization of the chemical phenotype of the CR + neurons in the human striatum.     

Trauma, mental representation, and the organization of memory for mother-referent material

Research on the effects of child maltreatment and exposure to community violence suggests that children who experience these types of traumatic events may be at risk for alterations and biases in attention and memory similar to those that have been observed in adults suffering from traumatic stress reactions. Along these lines, attachment theory posits that representational models of relationships also may act as moderators of similar cognitive biases by selectively guiding children's attention to and processing of interpersonal stimuli. Building upon the trauma and attachment literatures, the present investigation examined the links among trauma, representational models of caregivers, and children's memory for mother-relevant information using an incidental recall task in a sample of maltreated (n = 71) and nonmaltreated (n = 102) children between the ages of 8 and 13 years. Results were consistent with the hypothesis that experiences of trauma and representational models of caregivers are associated with differences in the way children process and retrieve information about positive and negative mother attribute words. In particular, experiences of trauma initially were associated with increased insecurity in children's representational models. Moreover, the interaction of traumatic experience and security of mental representation predicted children's recall for mother attribute words: victimized children with insecure models recalled the highest proportion of negative mother stimuli. Trauma and mental representation did not have a consistent effect on structurally encoded aspects of recall. Results were discussed in terms of the ways in which children who have experienced trauma process information about their worlds. The importance of assessing functioning in multiple developmental domains when studying memory also was discussed.