Spatial learning deficits in mice with a targeted glucocorticoid receptor gene disruption

Previous studies in rats using the Morris water maze suggested that the processing of spatial information is modulated by corticosteroid hormones through mineralocorticoid and glucocorticoid receptors in the hippocampus. Mineralocorticoid receptors appear to be involved in the modulation of explorative behaviour, while additional activation of glucocorticoid receptors facilitates the storage of information. In the present study we used the water maze task to examine spatial learning and memory in mice homozygous and heterozygous for a targeted disruption of the glucocorticoid receptor gene. Compared with wild-type controls, homozygous and heterozygous mice were impaired in the processing of spatial but not visual information. Homozygous mutants performed variably during training, without specific platform-directed search strategies. The spatial learning disability was partly compensated for by increased motor activity. The deficits were indicative of a dysfunction of glucocorticoid receptors as well as of mineralocorticoid receptors. Although the heterozygous mice performed similarly to wild-type mice with respect to latency to find the platform, their strategy was more similar to that of the homozygous mice. Glucocorticoid receptor-related long-term spatial memory was impaired. The increased behavioural reactivity of the heterozygous mice in the open field points to a more prominent mineralocorticoid receptor-mediated function. The findings indicate that (i) the glucocorticoid receptor is of critical importance for the control of spatial behavioural functions, and (ii) mineralocorticoid receptor-mediated effects on this behaviour require interaction with functional glucocorticoid receptors. Until the development of site-specific, inducible glucocorticoid receptor mutants, glucocorticoid receptor-knockout mice present the only animal model for the study of corticosteroid-mediated effects in the complete absence of a functional receptor.     

L'impact des sympt?mes somatiques dans l'évaluation de la dépression chez une population gériatrique.

Studied the relationship among age, physical health status, and psychic and somatic symptoms of depression among elderly adults. Human Ss: 318 male and female Canadian older adults (aged 65–102 yrs). Information on sociodemographic factors and health status was obtained using the Older American Research Scale, French version, by R. Lefran?ois et al (1988). A French version by P. Bourque and D. Beaudette (1982) of the Beck Depression Inventory was also used. The results were evaluated according to each S's sex, age, institutionalized residence status, and health status. Statistical tests were used. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A finite element analysis of damage propagation during metal forming process

In this paper damage propagation during metal forming process is investigated with the concept of continuum damage mechanics. An isotropic damage model based on the theory of materials of type N is adopted to describe the damage process of a ductile material with large elasto-viscoplastic deformation. To solve the finite elasto-viscoplasticity problem, a reasonable kinematic strain measure for largely deformed solids is used and the damage constitutive equations based on thermodynamical framework are developed. The stiffness degradation of the loaded material is chosen as a damage measure. An extended interior penalty method is used to impose the contact condition on the boundary. The highly nonlinear equilibrium equations are reduced to the incremental weak form and approximated by the total Lagrangian finite element method. The displacement control method along with the modified Riks' continuation technique based on displacement parameter is used to solve the incremental iterative equations. As numerical examples, upsetting, backward extrusion and punch problems are simulated and the results of damage propagation and J₂ stress contours with and without damage are presented. For punch problems, spring back and residual stresses are also presented.     

A note on computing environments and network reliability

Interest has increased during recent years in using microcomputers for implementation of network reliability algorithms. There are indications that some implementations suffer severe restrictions imposed by such a computing environment, whereas some other results indicate otherwise. This brief note attempts to clarify the apparently contradictory conclusions that would be naturally drawn from recent papers that treat this subject.     

Output probability from a general combinational network

In this paper, we present the method which calculates the probability of the output of a general combinational network being 1, when the probabilities is given for each input being 1. Also we present the method which derives the output probability expression in terms of a given set of input probabilities.The method is based on a basic probability axiom and Binary Decision Diagrams. A Boolean function for a combinational network is transformed into a Binary Decision Diagram and the output probability expression is derived from it. Therefore a derivation of the output probability for a combinational network can be straightforward. Some examples are showed that the method using Binary Decision Diagrams is simple and efficient. We can see a variation of the output probability for a combinational network according to the given set of input probabilities.     

Analysis of hazard area associated with hydrogen gas transmission pipelines

Hydrogen is considered to be the most important future energy carrier in many applications reducing significantly greenhouse gas emissions, but the safety issues associated with hydrogen applications need to be investigated and fully understood to be applicable as the carrier. Generally, the locations of hydrogen production and consumption are different. Hydrogen must be transported from the point of production to the point of use. Pipeline delivery is cheaper than all other methods for large quantities of hydrogen. The rupture of a hydrogen pipeline can lead to outcomes that can pose a significant threat to people and property in the immediate vicinity of the failure point. In this work, a simplified equation of hazard analysis is proposed for the pipeline transporting hydrogen, which relates the diameter, the operating pressure and the length of the pipeline to the size of the affected area in the event of a failure of the pipeline. The dominant hazards are thermal radiation from sustained fire and shock pressure from gas cloud explosion. For a transmission pipeline of hydrogen gas, the hazard area from the fire is slightly larger than by the other event. The hazard area is directly proportional to the operating pressure raised to the power one-half, and to the pipeline diameter. This simplified equation to estimate the hazard area will be a useful tool for safety management of hydrogen gas transmission pipelines.     

The influence of hydroelectric power generation on the body composition of juvenile Atlantic salmon

The fat and protein content, and thus energy resources of young (parr) Atlantic salmon (Salmo salar) were examined in a temperate river. Juvenile salmon exhibited distinct seasonal patterns of energy storage and use. The lowest levels of energy were found towards the end of winter (mean mass specific energy about 4.3 kJ·g^?1). There was a rapid accumulation of fat in spring/early summer in spite of low‐water temperatures (highest mean content of mass specific energy of about 5.0 kJ·g^?1 in June). By early autumn (August) there was a rapid depletion of fat and energy resources. The decline in specific energy during late summer was of the same magnitude as the corresponding winter decline. Furthermore, total fat and protein content, and thus energy resources of juveniles below a hydroelectric power plant (hydrostation (HS)) differed from those at a (lower) reference station (RS). The younger fish exhibited higher gains, but also larger losses of energy resources compared to corresponding values at the RS. Specifically during the summer, young of year (YOY) had 31% lower total energy content at the regulated site (mean 1.27 kJ per individual) than the RS (mean 1.84 kJ). Higher mortality may occur at the site most affected by the hydroelectric plant, where energy resources on average were higher, but where depletion was also most severe. Copyright © 2006 John Wiley & Sons, Ltd.     

Structural properties of 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 relaxor ferroelectric thin films on SrRuO3 conducting oxides

Coating of 0.65Pb(Mg_1/3Nb_2/3)O₃–0.35PbTiO₃ (PMN–PT) relaxor ferroelectrics by a sol–gel method is followed by growth of epitaxial SrRuO₃ (SRO) metallic oxide electrodes on SrTiO₃ (STO) single-crystal substrate by pulsed laser deposition. High-quality PMN–PT films on SRO with preferred growth orientation were successfully fabricated by controlling the operation parameters. Structural properties of relaxor ferroelectric PMN–PT thin films on SRO/STO substrates have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). In-plane and out-of-plane alignments of the heterostructure are confirmed and the structural twinning of the materials are also revealed.