105 research outputs found
INFORMATION VALUE OF PARAMETERS FOR HEART RHYTHM ANALYSIS UNDER CONDITIONS OF ANEMIC HYPOXIA
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GEANT4 simulation of the moderating neutrons spectrum
The probability and intensity of nuclear reactions involving neutrons are
characterized by the corresponding reaction cross-sections which are known to
depend strongly on the incident neutron energy. In real applications the
neutrons are seldom or never monoenergetic, and are usually characterized by
certain continuous energy spectrum. The detailed knowledge of the neutron
spectrum is crucial for numerous applications such as the nuclear reactor
operation, the traveling wave reactor (TWR) development, including the search
of the neutron energy ranges suitable for the wave nuclear burning, the search
and prediction of the so-called "blowup modes" in neutron-multiplying media,
the verification of neutron moderation theories and so on. In this paper we
describe a method of GEANT4-based Monte Carlo calculation of the neutron
spectrum evolution as well as the steady-state neutron spectrum in a system
containing a persistent neutron source.Comment: 18 pages, 10 figure
The bidirectional association between sleep problems and autism spectrum disorder
Background: Sleep difficulties are prevalent in children with autism spectrum disorder (ASD). The temporal nature of the association between sleep problems and ASD is unclear because longitudinal studies are lacking. Our aim is to clarify whether sleep problems precede and worsen autistic traits and ASD or occur as a consequence o
Beyond main effects of gene-sets: harsh parenting moderates the association between a dopamine gene-set and child externalizing behavior
Background: In a longitudinal cohort study, we investigated the interplay of harsh parenting and genetic variation across a set of functionally related dopamine genes, in association with children's externalizing behavior. This is one of the first studies to employ gene-based and gene-set approaches in tests of Gene by Environment (G × E) effects on complex behavior. This approach can offer an important alternative or complement to candidate gene and genome-wide environmental interaction (GWEI) studies in the search for genetic variation underlying individual differences in behavior. Methods: Genetic variants in 12 autosomal dopaminergic genes were available in an ethnically homogenous part of a population-based cohort. Harsh parenting was assessed with maternal (n = 1881) and paternal (n = 1710) reports at age 3. Externalizing behavior was assessed with the Child Behavior Checklist (CBCL) at age 5 (71 ± 3.7 months). We conducted gene-set analyses of the association between variation in dopaminergic genes and externalizing behavior, stratified for harsh parenting. Results: The association was statistically significant or approached significance for children without harsh parenting experiences, but was absent in the group with harsh parenting. Similarly, significant associations between single genes and externalizing behavior were only found in the group without harsh parenting. Effect sizes in the groups with and without harsh parenting did not differ significantly. Gene-environment interaction tests were conducted for individual genetic variants, resulting in two significant interaction effects (rs1497023 and rs4922132) after correction for multiple testing. Conclusion: Our findings are suggestive of G × E interplay, with associations between dopamine genes and externalizing behavior present in children without harsh parenting, but not in children with harsh parenting experiences. Harsh parenting may overrule the role of genetic factors in externalizing behavior. Gene-based and gene-set analyses offer promising new alternatives to analyses focusing on single candidate polymorphisms when examining the interplay between genetic and environmental factors
On the dispersion of solid particles in a liquid agitated by a bubble swarm
This article deals with the dispersion of solid particles in a liquid agitated by a homogeneous swarm of bubbles. The scale of interest lies between the plant scale (of the order of the tank) and the microscale (less than the bubble diameter). The strategy consists in simulating both the twophase flow of deforming bubbles and the motion of solid particles. The evolution of the spatial distribution of particles together with the encounter and entrainment phenomena is studied as a function of the void fraction and the relative size and mass of particles. The influence of the shape of the bubble and of the model of forces that govern the motion of particles is also considered
Preschool family irregularity and the development of sleep problems in childhood
Background: Previous studies have shown that poor family environments are related to more sleep problems;
however, little is known about how family irregularity in early life affects the development of sleep problems ove
Facial Cosmetics and Attractiveness: Comparing the Effect Sizes of Professionally-Applied Cosmetics and Identity
Forms of body decoration exist in all human cultures. However, in Western societies, women are more likely to engage in appearance modification, especially through the use of facial cosmetics. How effective are cosmetics at altering attractiveness? Previous research has hinted that the effect is not large, especially when compared to the variation in attractiveness observed between individuals due to differences in identity. In order to build a fuller understanding of how cosmetics and identity affect attractiveness, here we examine how professionally-applied cosmetics alter attractiveness and compare this effect with the variation in attractiveness observed between individuals. In Study 1, 33 YouTube models were rated for attractiveness before and after the application of professionally-applied cosmetics. Cosmetics explained a larger proportion of the variation in attractiveness compared with previous studies, but this effect remained smaller than variation caused by differences in attractiveness between individuals. Study 2 replicated the results of the first study with a sample of 45 supermodels, with the aim of examining the effect of cosmetics in a sample of faces with low variation in attractiveness between individuals. While the effect size of cosmetics was generally large, between-person variability due to identity remained larger. Both studies also found interactions between cosmetics and identity-more attractive models received smaller increases when cosmetics were worn. Overall, we show that professionally- applied cosmetics produce a larger effect than self-applied cosmetics, an important theoretical consideration for the field. However, the effect of individual differences in facial appearance is ultimately more important in perceptions of attractiveness
An exploration of the relationships among facial dimensions, age, sex, dominance status and personality in rhesus macaques (Macaca mulatta)
Aspects of personality in nonhuman primates have been linked to health, social relationships, and life history outcomes. In humans as well as nonhuman primates, facial morphology is associated with assertiveness, aggression, and measures of dominance status. In this study we aimed to examine the relationship among facial morphology, age, sex, dominance status, and ratings on the personality dimensions Confidence, Openness, Assertiveness, Friendliness, Activity, and Anxiety in rhesus macaques (Macaca mulatta). We measured facial width-to-height ratio (fWHR) and lower-height/full-height ratio (fLHFH) using photographs from 109 captive rhesus macaques, which observers also assessed for dominance status and personality, and explored the associations among facial morphology, age, sex, dominance status, and personality. fWHR and fLHFH personality associations depended on age category: Assertiveness was associated with higher fWHR and fLHFH, and Confidence was associated with lower fWHR and fLHFH, but all these associations were consistent only in individuals <8 yr. of age. We found fWHR and fLHFH to not be consistently associated with sex or dominance status; compared to younger individuals, we found few associations with fWHR and fLHFH for individuals older than 8 yr., which may be due to limited sample size. Our results indicate that in macaques <8 yr. old, facial morphology is associated with the Assertiveness and Confidence personality dimensions, which is consistent with results suggesting a relationship between fWHR and trait aggression in humans and assertiveness in brown capuchins, all of which implies that fWHR might be a cue to assertive and aggressive traits
Heritability and Genome-Wide Association Analyses of Sleep Duration in Children:The EAGLE Consortium
STUDY OBJECTIVES: Low or excessive sleep duration has been associated with multiple outcomes, but the biology behind these associations remains elusive. Specifically, genetic studies in children are scarce. In this study, we aimed to: (1) estimate the proportion of genetic variance of sleep duration in children attributed to common single nucleotide polymorphisms (SNPs), (2) identify novel SNPs associated with sleep duration in children, and (3) investigate the genetic overlap of sleep duration in children and related metabolic and psychiatric traits.METHODS: We performed a population-based molecular genetic study, using data form the EArly Genetics and Life course Epidemiology (EAGLE) Consortium. 10,554 children of European ancestry were included in the discovery, and 1,250 children in the replication phase.RESULTS: We found evidence of significant but modest SNP heritability of sleep duration in children (SNP h(2) 0.14, 95% CI [0.05, 0.23]) using the LD score regression method. A novel region at chromosome 11q13.4 (top SNP: rs74506765, P = 2.27e-08) was associated with sleep duration in children, but this was not replicated in independent studies. Nominally significant genetic overlap was only found (rG = 0.23, P = 0.05) between sleep duration in children and type 2 diabetes in adults, supporting the hypothesis of a common pathogenic mechanism.CONCLUSIONS: The significant SNP heritability of sleep duration in children and the suggestive genetic overlap with type 2 diabetes support the search for genetic mechanisms linking sleep duration in children to multiple outcomes in health and disease.</p
Nature’s solution to wellbore gas-leakage: Gilsonite
Increasing complexity, environmental regulations and the need for economic efficiency requires long term integrity of wellbores more than ever. A cement sheath’s primary function is to maintain wellbore integrity by providing total isolation from surrounding formations and the wellbore. Opposing the primary function of the cement sheath is hydrocarbon migration through 2 major interfaces; 1. Cement/Casing Interface, 2. Cement/Formation Interface. While hydrocarbon migration hazards vary from miniscule psi changes at surface to major blowouts the unwanted potential environmental hazards can ultimately affect economic returns. This study focuses on the use of a naturally occurring wellbore cement additive: Gilsonite as a potential agent in the mitigation of micro-annular flow because of its unique affinity to hydrocarbons. Gilsonite’s affinity and its potential to absorb hydrocarbons in the cement matrix is analyzed through microstructural analysis of hydrocarbon interaction with Gilsonite grains. The goal of this study is to provide a proof of concept to encourage further microstructural analysis of Gilsonite’s ability to inhibit micro-annular flow. This study is comprised of two separate phases; Phase 1 consists of experimentation on pure Gilsonite to gauge its affinity to hydrocarbons, while Phase 2 examines Gilsonite as part of the cement matrix
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