Scattering theory and ground-state energy of Dirac fermions in graphene with two Coulomb impurities

We study the physics of Dirac fermions in a gapped graphene monolayer containing two Coulomb impurities. For the case of equal impurity charges, we discuss the ground-state energy using the linear combination of atomic orbitals (LCAO) approach. For opposite charges of the Coulomb centers, an electric dipole potential results at large distances. We provide a nonperturbative analysis of the corresponding low-energy scattering problem

The mediating role of parenting in the associations between household chaos and children’s representations of family dysfunction

Children’s drawings are thought to reflect their mental representations of self and their interpersonal relations within families. Household chaos is believed to disrupt key proximal processes related to optimal development. The present study examines the mediating role of parenting behaviors in the relations between two measures of household chaos, instability and disorganization, and how they may be evidenced in children’s representations of family dysfunction as derived from their drawings. The sample (N= 962) is from a longitudinal study of rural poverty exploring the ways in which child, family, and contextual factors shape development over time. Findings reveal that, after controlling for numerous factors including child and primary caregiver covariates, there were significant indirect effects from cumulative family disorganization, but not cumulative family instability, on children’s representation of family dysfunction through parenting behaviors. Results suggest that the proximal effects of daily disorganization outweigh the effects of periodic instability overtime

Biodistribution of 64 Cu in Inflamed Rats Following Administration of Two Anti-Inflammatory Copper Complexes

64Cu was administered in two anti-inflammatory formulations to normal rats and to rats with 2 forms of local inflammation, namely (a) an acute paw oedema (elicited with carrageenan) or (b) a chronic granulomatous response to an implanted irritant (Mycobacterium tuberculosis in a polyurethane sponge). The copper formulations used were (i) a slow release one consisting of Cu(II) salicylate applied dermally with ethanol/DMSO and (ii) short acting hydrophilic complex (Cu(I)Cu(II)-penicillamine)5- given subcutaneously. Three types of changes in copper biodistribution with these forms of inflammation were discerned based on determination of 64Cu and copper content in the following organs: inflammatory locus (foot or sponge implant), kidney, liver, spleen, adrenals, brain, blood, thymus, heart, and skin (site of application). The most evident changes were in the kidneys, liver, spleen, adrenals, thymus and serum from animals with chronic granulomatous inflammation. In contrast, a short term acute inflammatory stress (carrageenan paw oedema) had little effect. While copper D-penicillamine (applied subcutaneously) appeared to move as a bolus through the animals, the results with the percutaneous copper salicylate formulation are consistent with it providing a slow release source of copper(II). Exogenous 64Cu from both formulations was sequestered at inflammatory sites (relative to serum). This may partly explain how applied copper complexes can be anti-inflammatory

Composição corporal e exigências líquidas de energia e proteína de bezerros da raça holandesa alimentados com dietas contendo diferentes níveis de volumoso

O objetivo deste trabalho foi avaliar os efeitos de diferentes níveis de volumoso nas dietas, sobre a composição corporal, as exigências de energia líquida para mantença e ganho de peso e os requerimentos líquidos de proteína para ganho de peso. Cinquenta e dois bezerros da raça Holandesa, puros por cruzamento, não-castrados, com idade média de 60 dias e peso vivo (PV) inicial de 78 kg foram usados. Oito animais foram abatidos ao início do experimento, como referência. Outros oito animais foram alimentados com dietas na proporção de 90% de volumoso e 10% de concentrado para atender às exigências ligeiramente acima da mantença (grupo de mantença). Os 36 animais restantes foram distribuídos nos tratamentos, em delineamento inteiramente casualizado, em quatro grupos de nove animais, de acordo com o nível de volumoso nas dietas: 10, 25, 40 e 55%, na base da MS, usando-se feno de capim coast-cross (Cynodon dactylon), fubá de milho e farelo de soja, os quais constituíram dietas com aproximadamente 16% de PB.. Cinco animais de cada tratamento foram abatidos, quando atingiram 190 ± 10 kg PV e quatro, quando atingiram 300 ± 10 kg PV. A exigência de energia líquida (EL) para mantença foi estimada da equação de regressão do logaritmo da producão de calor e em relação ao consumo de energia metabolizável (CEM), assumindo CEM igual a zero. Equações de regressão foram ajustadas, para cada nível de volumoso e em conjunto, do logaritmo das quantidades corporais de gordura, proteína e energia, em função do logaritmo do peso corporal vazio (PCVZ). A exigência de energia líquida para mantença foi, em média, de 110,46 kcal/kg0,75. A quantidade de gordura e o conteúdo de energia no ganho de peso aumentaram, à medida que se elevou o PV do animal, para todos os níveis de volumoso e em conjunto. As exigências líquidas de energia e proteína para ganho de 1 kg de PCVZ, para um animal de 300 kg de peso vivo, foram 2,83 Mcal/dia e 183,20 g/dia, respectivamente. As exigências líquidas de energia e proteína para ganho de bezerros da raça Holandesa, em média, aumentaram com o aumento do peso corporal vazio

The genetic architecture of the human cerebral cortex

INTRODUCTION The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. RATIONALE To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 individuals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. RESULTS We identified 306 nominally genome-wide significant loci (P < 5 × 10−8) associated with cortical structure in a discovery sample of 33,992 participants of European ancestry. Of the 299 loci for which replication data were available, 241 loci influencing surface area and 14 influencing thickness remained significant after replication, with 199 loci passing multiple testing correction (P < 8.3 × 10−10; 187 influencing surface area and 12 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness; surface area and thickness showed a negative genetic correlation (rG = −0.32, SE = 0.05, P = 6.5 × 10−12), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain samples, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on individual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 10 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. CONCLUSION This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function

Interference-controlled excitation of a hybrid resonance in Xe

In well studied examples of multi-photon driven hybrid resonances, a resonant or near resonant transition in a simple molecule or in atoms during collision, leads to a “product” which subsequently is further excited.</jats:p