38 resultados para BEHAVIORAL COMPONENTS

em University of Queensland eSpace - Australia


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As part of a large ongoing project, the Memory, Attention and Problem Solving (MAPS) study, we investigated whether genetic variability explains some of the variance in psychophysiological correlates of brain function, namely, the P3 and SW components of event-related potentials (ERPs). These ERP measures are minute time recordings of brain processes and, because they reflect fundamental cognitive processing, provide a unique window on the millisecondto- millisecond transactions that occur at the cognitive level and taking place in the human brain. The extent to which the variance in P3 and SW components is influenced by genetic factors was examined in 350 identical and nonidentical twin pairs aged 16 years. ERPs were recorded from 15 scalp electrodes during the performance of a visuospatial delayed response task that engages working memory. Multivariate genetic analyses using MX were used to estimate genetic and environmental influences on individual differences in brain functioning and to identify putative genetic factors common to the ERP measures and psychometric IQ. For each of the ERP measures, correlation among electrode sites was high, a spatial pattern was evident, and a large part of the genetic variation in the ERPs appeared to be mediated by a common genetic factor. Moderate within-pair concordance in MZ pairs was found for all ERP measures, with higher correlations found for P3 than SW, and the MZ twin pair correlations were approximately twice the DZ correlations, suggesting a genetic influence. Correlations between ERP measures and psychometric IQ were found and, although moderately low, were evident across electrode site. The analyses show that the ERP components, P3 and SW, are promising phenotypes of the neuroelectrical activity of the brain and have the potential to be used in linkage and association analysis in the search for QTLs influencing cognitive function.

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At present, there is a variety of formalisms for modeling and analyzing the communication behavior of components. Due to a tremendous increase in size and complexity of embedded systems accompanied by shorter time to market cycles and cost reduction, so called behavioral type systems become more and more important. This chapter presents an overview and a taxonomy of behavioral types. The intentions of this taxonomy are to provide a guidance for software engineers and to form the basis for future research.

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There have been few replicated examples of genotype x environment interaction effects on behavioral variation or risk of psychiatric disorder. We review some of the factors that have made detection of genotype x environment interaction effects difficult, and show how genotype x shared environment interaction (GxSE) effects are commonly confounded with genetic parameters in data from twin pairs reared together. Historic data on twin pairs reared apart can in principle be used to estimate such GxSE effects, but have rarely been used for this purpose. We illustrate this using previously published data from the Swedish Adoption Twin Study of Aging (SATSA), which suggest that GxSE effects could account for as much as 25% of the total variance in risk of becoming a regular smoker. Since few separated twin pairs will be available for study in the future, we also consider methods for modifying variance components linkage analysis to allow for environmental interactions with linked loci.

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We present a model linking perceptions of job insecurity to emotional reactions and negative coping behaviors. Our model is based on the idea that emotional variables explain, in part, discrepant findings reported in previous research. In particular, we propose that emotional intelligence moderates employees' emotional reactions to job insecurity and their ability to cope with associated stress. In this respect, low emotional intelligence employees are more likely than high emotional intelligence employees to experience negative emotional reactions to job insecurity and to adopt negative coping strategies.

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The aim of this mental health promotion initiative was to evaluate the effectiveness of a universally delivered group behavioral family intervention (BFI) in preventing behavior problems in children. This study investigates the transferability of an efficacious clinical program to a universal prevention intervention delivered through child and community health services targeting parents of preschoolers within a metropolitan health region. A quasiexperimental two-group (BFI, n=804 vs. Comparison group, n=806) longitudinal design followed preschool aged children and their parents over a 2-year period. BFI was associated with significant reductions in parent-reported levels of dysfunctional parenting and parent-reported levels of child behavior problems. Effect sizes on child behavior problems ranged from large (.83) to moderate (.47). Positive and significant effects were also observed in parent mental health, marital adjustment, and levels of child rearing conflict. Findings are discussed with respect to their implication for significant population reductions in child behavior problems as well as the pragmatic challenges for prevention science in encouraging both the evaluation and uptake of preventive initiatives in real world settings.

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The reflectance signatures of plantation pine canopy and understorey components were measured using a spectro-radiometer. The aim was to establish whether differences observed in the reflectance signature of stressed and unstressed pine needles were consistent with observed differences in the reflectance of multispectral Landsat Thematic Mapper (TM) images of healthy and stressed forest. Because overall scene reflectance includes the contribution of each scene component, needle reflectance may not be representative of canopy reflectance. In this investigation, a limited dataset of reflectance signatures from stressed and unstressed needles confirmed the negative relationship between pine needle health and reflectance which was observed in visible red wavelengths. However, the reflectance contribution from bushes, pine needle litter and bare soil tended to reinforce this relationship suggesting that in this instance, overall scene reflectance is comprised of the proportional reflectance of each scene component. In near infrared wavelengths, differences between healthy and stressed needle reflectance suggested a strong positive relationship between reflectance and tree health. For Landsat TM images, previous research had only observed a weak positive relationship between stand health and near infrared reflectance in these pine canopies. This suggests that for multispectral Landsat TM images, reflectance of near infrared light from pine canopies may be affected by other factors which may include the scattering of light within canopies. These results are seen as promising for the use of hyperspectral images to detect stand health, provided that pixel reflectance is not influenced by other scene components.

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A simple theoretical framework is presented for bioassay studies using three component in vitro systems. An equilibrium model is used to derive equations useful for predicting changes in biological response after addition of hormone-binding-protein or as a consequence of increased hormone affinity. Sets of possible solutions for receptor occupancy and binding protein occupancy are found for typical values of receptor and binding protein affinity constants. Unique equilibrium solutions are dictated by the initial condition of total hormone concentration. According to the occupancy theory of drug action, increasing the affinity of a hormone for its receptor will result in a proportional increase in biological potency. However, the three component model predicts that the magnitude of increase in biological potency will be a small fraction of the proportional increase in affinity. With typical initial conditions a two-fold increase in hormone affinity for its receptor is predicted to result in only a 33% increase in biological response. Under the same conditions an Ii-fold increase in hormone affinity for receptor would be needed to produce a two-fold increase in biological potency. Some currently used bioassay systems may be unrecognized three component systems and gross errors in biopotency estimates will result if the effect of binding protein is not calculated. An algorithm derived from the three component model is used to predict changes in biological response after addition of binding protein to in vitro systems. The algorithm is tested by application to a published data set from an experimental study in an in vitro system (Lim et al., 1990, Endocrinology 127, 1287-1291). Predicted changes show good agreement (within 8%) with experimental observations. (C) 1998 Academic Press Limited.

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The present investigation assessed the reliability and validity of the scores of a subjective measure of desired aspirations and a behavioral measure of enacted aspirations. A sample of 5,655 employees was randomly split into two halves. Principal components analysis on Sample 1, followed by confirmatory factor analysis on Sample 2, confirmed the desired and enacted scales as distinct but related measures of managerial aspirations. The desired and enacted scales had satisfactory levels of internal consistency and temporal stability over a 1-year period. Relationships between the measures of desired and enacted managerial aspirations and both attitudinal and behavioral criteria, measured concurrently and 1 year later, provided preliminary support for convergent and discriminant validity for our sample. Desired aspirations demonstrated stronger validity than enacted aspirations. Although further examination of the psychometric properties of the scales is warranted, the present findings provide promising support for their validity and reliability for our sample.

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In the adult male Sprague-Dawley rat, a species commonly used to study tolerance to the antinociceptive effects of morphine, approximate to 10% of the morphine dose is metabolized to normorphine-3-glucuronide (NM3G). In contrast, NM3G is a relatively minor metabolite of morphine in human urine reportedly accounting for approximate to 1% of the morphine dose. To date, the pharmacology of NM3G has been poorly characterized. Therefore, our studies were designed to determine whether the intrinsic pharmacology of NM3G is similar to that of morphine-3-glucuronide (M3G), the major metabolite of morphine, which has been shown to be a potent central nervous system (CNS) excitant and to attenuate the intrinsic antinociceptive effects of morphine in rats. The CNS excitatory potency of NM3G was found to be approximately half that of M3G, inducing convulsions in rats at intracerebroventricular (i.c.v.) doses of greater than or equal to 16.8 nmol. When administered before morphine (70 nmol i.c.v.), NM3G (8.9 nmol i.c.v.) attenuated antinociception for up to 2 hr, but when administered after morphine, no significant attenuation of morphine antinociception was observed. Thus, after i.c.v. administration, NM3G like M3G, is a potent CNS excitant and antianalgesic in the rat. NM3G may therefore play a role in the development of tolerance to the antinociceptive effects of morphine in the rat as has been proposed previously for M3G.

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This paper reports on the implementation of a psychoeducational program utilizing cognitive-behavioral principles. The efficacy of this psychoeducational treatment program in modifying dysfunctional attitudes in patients with chronic low back pain was examined using a two-group pretest posttest design with a follow-lip at 3 months Thirty patients (average age = 44.37 SD = 13.71) participated in the study, with 15 in the psychoeducational treatment group and 15 in the placebo control group. These two conditions were added on to an existing eclectic inpatient pain management program. After assessment on the IPAM (The Integrated Psychosocial Assessment Model), scores were reduced to multivariate composite scores on the factors of illness behavior depressed and negative cognitions, and acute pain strategies. Results of a group x time repeated measures analysis of variance for the three pain factors revealed a significant main effect for group (F(23,1) = 5.00 p < .04), tempered by a significant interaction between group and rime on the 'depressed and negative' pain factor (F(23,1) = 4.77 p < .04). Patients in the treatment group improved significantly over time and significantly more than the placebo control group patients at posttreatment. Results provide support for the program in increasing patients' feelings of control over their pain and the use of positive coping strategies, while reducing perceived helplessness, depression, disability, and pain intensity.

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Introduction: This paper reviews studies of physical activity interventions in health care settings to determine effects on physical activity and/or fitness and characteristics of successful interventions. Methods: Studies testing interventions to promote physical activity in health care settings for primary prevention (patients without disease) and secondary prevention (patients with cardiovascular disease [CVD]) were identified by computerized search methods and reference lists of reviews and articles. Inclusion criteria included assignment to intervention and control groups, physical activity or cardiorespiratory fitness outcome measures, and, for the secondary prevention studies, measurement 12 or more months after randomization. The number of studies with statistically significant effects was determined overall as well as for studies testing interventions with various characteristics. Results: Twelve studies of primary prevention were identified, seven of which were randomized. Three of four randomized studies with short-term measurement (4 weeks to 3 months after randomization), and two of five randomized studies with long-term measurement (6 months after randomization) achieved significant effects on physical activity. Twenty-four randomized studies of CVD secondary prevention were identified; 13 achieved significant effects on activity and/or fitness at twelve or more months. Studies with measurement at two time points showed decaying effects over time, particularly if the intervention were discontinued. Successful interventions contained multiple contacts, behavioral approaches, supervised exercise, provision of equipment, and/or continuing intervention. Many studies had methodologic problems such as low follow-up rates. Conclusion: Interventions in health care settings can increase physical activity for both primary and secondary prevention. Long-term effects are more likely with continuing intervention and multiple intervention components such as supervised exercise, provision of equipment, and behavioral approaches. Recommendations for additional research are given.

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This study was designed to determine in rats whether morphine-3-glucuronide (M3G) produces its neuro-excitatory effects most potently in the ventral hippocampus (as has been reported previously for subanalgesic doses of opioid peptides). Guide cannulae were implanted into one of seven regions of the rat brain: lateral ventricle; ventral, CA1 and CA2-CA3 regions of the hippocampus; amygdala; striatum or cortex. After a 7 day recovery period, rats received intracerebral injections of (i) M3G (1.1 or 11 nmol) (ii) DADLE ([D-Ala(2),D-Leu(5)]enkephalin), (45 nmol, positive controls) or (iii) vehicle (deionised water), and behavioral excitation was quantified over 80 min. High-dose M3G (11 nmol) evoked behavioral excitation in all brain regions but the onset, severity and duration of these effects varied considerably among brain regions. By contrast, low-dose M3G (1.1 nmol) evoked excitatory behaviors only when administered into the ventral hippocampus and the amygdala, with the most potent effects being observed in the ventral hippocampus. Prior administration of the nonselective opioid antagonists, naloxone and beta-funaltrexamine into the ventral hippocampus, markedly attenuated low-dose M3G's excitatory effects but did not significantly alter levels of excitation evoked by high-dose M3G. Naloxone given 10 min after M3G (1.1 or 11 nmol) did not significantly attenuate behavioral excitation. Thus, M3G's excitatory behavioral effects occur most potently in the ventral hippocampus as reported previously for subanalgesic doses of opioid peptides, and appear to be mediated through at least two mechanisms, one possibly involving excitatory opioid receptors and the other, non-opioid receptors.

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The evolution of a positive genetic correlation between male and female components of mate recognition systems will result as a consequence of assortative mating and, in particular, is central to a number of theories of sexual selection. Although the existence of such genetic correlations has been investigated in a number of taxa, it has yet to be shown that such correlations evolve and whether they may evolve as rapidly as suggested by sexual selection models. In this study, I used a hybridization experiment to disrupt natural mate recognition systems and then observed the subsequent evolutionary dynamics of the genetic correlation between male and female components for 56 generations in hybrids between Drosophila serrata and Drosophila birchii. The genetic correlation between male and female components evolved from 0.388 at generation 5 to 1.017 at generation 37 and then declined to -0.040 after a further 19 generations. These results indicated that the genetic basis of the mate recognition system in the hybrid populations evolved rapidly. The initial rapid increase in the genetic correlation was consistent with the classic assumption that male and female components will coevolve under sexual selection. The subsequent decline in genetic correlation may be attributable to the fixation of major genes or, alternatively, may be a result of a cyclic evolutionary change in mate recognition.

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Recent reports have shown neurodegenerative disorders to be associated with abnormal expansions of a CAG trinucleotide repeat allele at various autosomal loci. While normal chromosomes have 14 to 44 repeats, disease chromosomes may have 60 to 84 repeats. The number of CAG repeats on mutant chromosomes correlates with increasing severity of disease or decreasing age at onset of symptoms. Since we are interested in identifying the many quantitative trait loci (QTL) influencing brain functioning, we examined the possibility that the number of CAG repeats in the normal size range at these loci are relevant to "normal" neural functioning. We have used 150 pairs of adolescent (aged 16 years) twins and their parents to examine allele size at the MJD, SCA1, and DRPLA loci in heterozygous normal individuals. These are part of a large ongoing project using cognitive and physiological measures to investigate the genetie influences on cognition, and an extensive protocol of tests is employed to assess some of the key components of intellectual functioning. This study selected to examine full-scale psychometric IQ (FSIQ) and a measure of information processing (choice reaction time) and working memory (slow wave amplitude). CAG repeat size was determined on an ABI Genescan system following multiplex PCR amplification. Quantitative genetic analyses were performed to determine QTL effects of MJD, SCA1, and DRPLA on cognitive functioning. Analyses are in progress and will be discussed.

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While there is a developing understanding of the influence of sleep on cardiovascular autonomic activity in humans, there remain unresolved issues. In particular, the effect of time within the sleep period, independent of sleep stage, has not been investigated. Further, the influence of sleep on central sympathetic nervous system (SNS) activity is uncertain because results using the major method applicable to humans, the low frequency (LF) component of heart rate Variability (HRV), have been contradictory, and because the method itself is open to criticism. Sleep and cardiac activity were measured in 14 young healthy subjects on three nights. Data was analysed in 2-min epochs. All epochs meeting specified criteria were identified, beginning 2 h before, until 7 h after, sleep onset. Epoch values were allocated to 30-min bins and during sleep were also classified into stage 2, slow wave sleep (SWS) and rapid eye movement (REM) sleep. The measures of cardiac activity were heart irate (HR), blood pressure (BP), high frequency (HF) and LF components of HRV and pre-ejection period (PEP). During non-rapid eye movement (NREM) sleep autonomic balance shifted from sympathetic to parasympathetic dominance, although this appeared to be more because of a shift in parasympathetic nervous system (PNS) activity. Autonomic balance during REM was in general similar to wakefulness. For BP and the HF and LF components the change occurred abruptly at sleep onset and was then constant over time within each stage of sleep, indicating that any change in autonomic balance over the sleep period is a consequence of the changing distribution of sleep stages. Two variables, HR and PEP, did show time effects reflecting a circadian influence over HR and perhaps time asleep affecting PEP. While both the LF component and PEP showed changes consistent with reduced sympathetic tone during sleep, their pattern of change over time differed.