Autonomic correlates of attention-deficit/hyperactivity disorder and oppositional defiant disorder in preschool children.

Numerous studies have revealed autonomic underarousal in conduct-disordered adolescents and antisocial adults. It is unknown, however, whether similar autonomic markers are present in at-risk preschoolers. In this study, the authors compared autonomic profiles of 4- to 6-year-old children with attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD; n = 18) with those of age-matched controls (n = 20). Children with ADHD and ODD exhibited fewer electrodermal responses and lengthened cardiac preejection periods at baseline and during reward. Although group differences were not found in baseline respiratory sinus arrhythmia, heart rate changes among ADHD and ODD participants were mediated exclusively by parasympathetic withdrawal, with no independent sympathetic contribution. Heart rate changes among controls were mediated by both autonomic branches. These results suggest that at-risk preschoolers are autonomically similar to older externalizing children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal reflections: Barriers and strategies in increasing diversity in psychology.

In this article, six faculty and students of color who participated in a panel discussion at a symposium during the National Multicultural Conference and Summit of 2003 talk about the barriers they encountered and continue to encounter in their graduate training and places of employment. They also discuss strategies they found to be effective, enhancing, and positive and suggest other possibilities. The contributors describe their relationships with dominant-group and minority peers and talk about how issues of social class, disability, and sexual orientation as well as color have been part of their experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical considerations in infant nutrition trials

Infant nutrition trials usually require developmental follow-up, often to 18 mon, and sometimes beyond reading ability at age 7 yr. They are therefore logistically complex and costly, and should be conducted to a high statistical standard. With examples, we focus on: good practice in nutrition trials and the goal of a common protocol; how to set plausible trial targets and to work out trial size accordingly; statistical observations on assessing visual maturation; and methods of randomization, including the method known as minimization, which can be adapted to select more appropriately a comparison cohort of breast-fed infants. We end with discussion of analysis and reporting standards, including the give-aways (or tell-tale signs) to be on the look out for. A Cochrane Collaboration for systematic review of randomized trials of infant nutrition is proposed.     

Estimation of the exposure of the French population to the BSE agent: comparison of the 1980-95 consumption of beef products containing mechanically recovered meat in France and the UK,by birth cohort and gender

Assuming that human exposure to BSE was through beef mechanically recovered meat (MRM) consumed as burgers and other meat products, we estimated the French consumption of different food items containing beef MRM, and compared these consumptions for French and British populations. To estimate consumption of meat products containing bovine MRM, we used dietary data from national individual and household food surveys conducted between 1980 and 1995. After reconciliation of consumption data between the available surveys and calendar year adjustments, we simulated consumption of one-thousandth of the French population. Consumption was estimated by birth cohort and gender, and for the periods 1980-89 and 1990-95 separately. Data showed that burgers (including manufactured minced meat) represented around 75-80% of the individual consumption of meat products containing MRM, and that consumption of burgers increased by 40% over the 1980-95 period. In all age groups, consumption was higher in males than in females. In both genders, the 1940-69 birth cohort had the highest mean consumption of burgers and other beef products containing MRM. Similar findings have been reported for the UK population. Estimated consumption of bovine MRM per calendar year increased markedly over the study period, concomitantly with an increase of bovine carcasses imported from the UK. Comparison of the 1980-1995 pattern of bovine MRM consumption in the UK and France indicated thatthis consumption peaked later in France than in the UK. This difference might result in different temporal pattern of vCJD incidence.     

Dynamic demonstration of diffractive optic analog-to-digital converter scheme

Dynamic behavior of an analog-to-digital converter (ADC) based on diffractive optical element(s) (DOE)(s) was studied and found to be in agreement with predictions. The analog signal was translated to an angular deflection of a laser beam by means of an acousto-optic (AO) cell. The number of bits in this experimental demonstration was three, using an eight-element DOE array. The maximum sample rate was found to be 2.5 MS/s, the limiting factor being the transit time for the acoustic wave across the width of the laser beam in the AO cell. The study is intended as a first dynamic demonstration of a proposed ADC scheme previously demonstrated in a quasi-static version. The full potential of the ADC scheme will require the use of a fast tunable diode laser to replace the AO deflection scheme used here.     

Efficient entropy estimation based on doubly stochastic models for quantized wavelet image data.

Under a rate constraint, wavelet-based image coding involves strategic discarding of information such that the remaining data can be described with a given amount of rate. In a practical coding system, this task requires knowledge of the relationship between quantization step size and compressed rate for each group of wavelet coefficients, the R-Q curve. A common approach to this problem is to fit each subband with a scalar probability distribution and compute entropy estimates based on the model. This approach is not effective at rates below 1.0 bits-per-pixel because the distributions of quantized data do not reflect the dependencies in coefficient magnitudes. These dependencies can be addressed with doubly stochastic models, which have been previously proposed to characterize more localized behavior, though there are tradeoffs between storage, computation time, and accuracy. Using a doubly stochastic generalized Gaussian model, it is demonstrated that the relationship between step size and rate is accurately described by a low degree polynomial in the logarithm of the step size. Based on this observation, an entropy estimation scheme is presented which offers an excellent tradeoff between speed and accuracy; after a simple data-gathering step, estimates are computed instantaneously by evaluating a single polynomial for each group of wavelet coefficients quantized with the same step size. These estimates are on average within 3% of a desired target rate for several of state-of-the-art coders.     

Parental involvement, homework, and TV time: Direct and indirect effects on high school achievement.

Examined the direct and indirect effects of TV time, homework, and parental involvement on high school seniors' achievement using 28,051 high school seniors selected from the dataset of the High School and Beyond Longitudinal Study conducted by the National Opinion Research Center (1980). Data indicate that homework had an important, positive effect on student achievement, and TV time had a smaller, negative effect. Parental involvement had no direct effect on seniors' achievement scores but did positively influence the amount of time that seniors spent on homework. Further analysis suggested the possibilities of low homework demands and of excessive weekday TV viewing. Given the time spent on TV and homework and their influence on achievement, it is suggested that these variables be considered in the push for educational improvement. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dysfunctional attitudes and attribution style in healthy controls and patients with schizophrenia, psychotic depression, and nonpsychotic depression.

Compared the scores of 242 psychiatric inpatients with schizophrenia, psychotic depression, or nonpsychotic depression and 53 healthy controls on the Attribution Style Questionnaire (ASQ) and the Dysfunctional Attitude Scale (DAS). Results provide mixed support for the cognitive and learned helplessness models of depression. Depressed Ss scored significantly higher than healthy controls on the DAS and ASQ, but there were no differences between depressed and schizophrenic Ss. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)