Self-esteem and well-being are important for successful aging, and some evidence suggests that self-esteem and well-being are associated with hippocampal volume, cognition and stress responsivity. Whereas most of this evidence is based on studies on older adults, we investigated self-esteem, well-being and hippocampal volume in 474 male middle-aged twins. Self-esteem was significantly positively correlated with hippocampal volume (0.09, P = 0.03 for left hippocampus, 0.10, P = 0.04 for right). Correlations for well-being were not significant (Ps > 0.05). There were strong phenotypic correlations between self-esteem and well-being (0.72, P < 0.001) and between left and right hippocampal volume (0.72, P < 0.001). In multivariate genetic analyses, a two-factor additive genetic and unique environmental (AE) model with well-being and self-esteem on one factor and left and right hippocampal volumes on the other factor fits the data better than Cholesky, independent pathway or common pathway models. The correlation between the two genetic factors was 0.12 (P = 0.03); the correlation between the environmental factors was 0.09 (P > 0.05). Our results indicate that largely different genetic and environmental factors underlie self-esteem and well-being on one hand and hippocampal volume on the other. 相似文献
Abstract. Integrated synusial phytosociology combined with traditional measures of diversity is used to describe the structure of vascular vegetation diversity along the forested riparian landscape of the upper Oise valley (Belgium and France). The two dimensions (longitudinal and lateral) of the geomorphological complex are examined at four scales: synusia, phytocoenosis, tesela and catena. The results support the following hypotheses: (1) the environmental gradients observed, particularly the lateral ones, are very complex; (2) there is a clear lack of coupling between the tree, shrub and herb layers, which indicates a differential response to the underlying influence of environmental controls; (3) moderate flooding‐induced disturbance enhances herb species richness; (4) stressful environments support a low plant species diversity but a high synusial richness; (5) natural factors (substrate, climate, disturbance) are more important at the synusia and phytocoenose scales, but (6) anthropogenic disturbances, mainly through forest and river management, are more important at the landscape level. By considering plant communities as structural‐dynamic entities of ecosystems in a landscape context, integrated synusial phytosociology provides a basis for decomposing a complex system since the different hierarchical levels are both nested and thus strongly relational and process‐based. 相似文献
Constructing core/shell nanostructures with optimal structure and composition could maximize the solar light utilization. Here, using an Al nanocone array as a substrate, a well‐defined regular array of AZO/TiO2 core/shell nanocones with uniformly dispersed Au nanoparticles (AZO/TiO2/Au NCA) is successfully realized through three sequential steps of atomic layer deposition, physical vapor deposition, and annealing processes. By tuning the structural and compositional parameters, the advantages of light trapping and short carrier diffusion from the core/shell nanocone array, as well as the surface plasmon resonance and catalytic effects from the Au nanoparticles can be maximally utilized. Accordingly, a remarkable photoelectrochemical (PEC) performance can be acquired and the photocurrent density of the AZO/TiO2/Au NCA electrode reaches up to 1.1 mA cm?2 at 1.23 V, versus reversible hydrogen electrode (RHE) under simulated sunlight illumination, which is five times that of a flat AZO/TiO2 electrode (0.22 mA cm?2). Moreover, the photoconversion of the AZO/TiO2/Au NCA electrode approaches 0.73% at 0.21 V versus RHE, which is one of the highest values with the lowest applied bias ever reported in Au/TiO2 PEC composites. These results demonstrate a feasible route toward the scalable fabrication of well‐modulated core/shell nanostructures and can be easily applied to other metal/semiconductor composites for high‐performance PEC. 相似文献
The quality of water sources and its potential health implications to adults and children populations of respective major communities in Northern Cross-River was assessed. Water samples (n = 10/water source/site) were collected from three (Okpoma, Okuku and Ugaga) communities and heavy metal concentrations (Lead (Pb), Cadmium (Cd), Chromium (Cr), Manganese (Mn), Nickel (Ni), Copper (Cu), Cobalt (Co), and Zinc (Zn)) were evaluated using Atomic Absorption Spectrometer (AAS). Overall, Pb, Cd, Ni, and Co were higher than drinking water guidelines, while only Cr, Mn, Cu, and Zn were within the permissible limits. The estimated average daily intake (EADI) and target hazard quotient (THQ) were used to determine risk implications for adult and children consumer populations. The EADI for Pb in adults for borehole water, Pb and Cr by child consumer population for borehole and shallow well water exceeded the reference dose (RfD) by USEPA. The THQ for adult population were >1 for Pb in borehole water and >1 for Pb and Cr across all sites for the child consumer population. Overall, our findings indicate toxicity and higher hazard risk for both adult (Pb) and children (Pb and Cr) populations that source drinking water from borehole and shallow well water in these communities. 相似文献
Disposal quantities of organic wastes at the Brooklawn Site in Louisiana are suspected to equal nearly 1.45 × 108Kg, making this site one of the most contaminated dense nonaqueous phase liquid (DNAPL) sites in the world. Remedial activities at the site include groundwater and DNAPL extraction from recovery wells. DNAPL recovery has markedly declined in recent years, with many of the peripheral wells showing negligible recovery of organic liquids. Three-dimensional simulations of DNAPL movement in the subsurface were conducted using the STOMP simulator, including a new coupled-well model. The objectives of this modeling effort were to (1) determine the fate and transport of infiltrated DNAPL, and (2) measure the effects of active recovery through DNAPL pumping. A detailed three-dimensional geologic model of the Brooklawn primary DNAPL disposal area was developed and used as the framework for DNAPL simulations. Additionally, site-specific data were obtained to determine the most important hydraulic properties of the subsurface related to DNAPL movement and formation of entrapped DNAPL in the laboratory. In addition to a simulation using the best available subsurface information, several sensitivity simulations were conducted to assess the effects on DNAPL migration. These simulations include DNAPL pumping, well screen extension, an alternative geology, increased DNAPL density, lower DNAPL viscosity, and more-permeable sand and silt deposits.
Results of the simulations were compared to field data that define the extent of DNAPL movement based on where DNAPL has been extracted in the site recovery wells. The model simulations show that pumping has a negligible effect on subsurface DNAPL saturations and movement. Pumped DNAPL volumes diminish rapidly due to the limited radius of influence of the wells and movement of the DNAPL out of the zone of influence of the wells with a maximum radius of influence of about 6 m. The numerical analysis also demonstrates that it is impractical to extend existing wells or install new wells to retrieve enough DNAPL to affect the overall extent of DNAPL movement. 相似文献