Connaissance des résultats et contr?le spatiotemporel dans une tache d'anticipation-co?ncidence chez des enfants de 6 à 10 ans.

Studied the effects of knowledge of results (KR), either spatial or temporal, on performance of a coincidence-timing task among Canadian children. Human subjects: 90 male and female Canadian children (aged 6–10 yrs). Ss were divided into 3 age groups (mean age 6.8 yrs, 8.3 yrs, and 10.2 yrs). Each age group was divided into 3 experimental groups: 1 group received spatial KR, 1 group received temporal KR, and 1 group received no KR during practice sessions for a coincidence-timing task. The task consisted of moving an object horizontally with the hand to a spot corresponding to the movement of a visual stimulus. The object was to reach the correct spot at the same time as the visual stimulus, which came from either the right or the left at speeds of 100 or 152 cm/s. The results were analyzed according to Ss' age, speed of stimulus, direction of stimulus, type of KR training, and whether or not the S's object arrived before or after the visual stimulus. A multivariate analysis of variance (MANOVA) was used. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of diffraction gratings by using an edge element method

Typically the grating problem is formulated for TE and TM polarizations by using, respectively, the electric and magnetic fields aligned with the grating wall and perpendicular to the plane of incidence, and this leads to a one-field-component problem. For some grating profiles such as metallic gratings with a triangular profile, the prediction of TM polarization by using a standard finite-element method experiences a slower convergence rate, and this reduces the accuracy of the computed results and also introduces a numerical polarization effect. This discrepancy cannot be seen as a simple numerical issue, since it has been observed for different types of numerical methods based on the classical formulation. Hence an alternative formulation is proposed, where the grating problem is modeled by taking the electric field as unknown for TM polarization. The application of this idea to both TE and TM polarizations leads to a two-field-component problem. The purpose of the paper is to propose an edge finite-element method to solve this wave problem. A comparison of the results of the proposed formulation and the classical formulation shows improvement and robustness in the new approach.     

Functional analysis of depressive states: integration of cognitive and behavioral contributions (author's transl)

The article provides a review of the main contributions both of behaviorally--and cognitively--oriented litterature on depressive states and depressive behaviors. These various data are organised so as to form into a tool for the functional analysis of depression: symptoms--structures--releasing factors--mechanisms--maintaining and aggravating factors. Synthetic tables at the end of the article constitute a first attempt at a clinical report allowing the pratician to evaluate the contributions--as well as the limits--of a behavioral approach of the depression phenomenom.     

Resting energy expenditure and food-induced thermogenesis in obese children

Nineteen overweight girls 14.54 +/- 0.38 years of age were studied. Results were compared with those obtained in eight age-matched (14.07 +/- 0.51 years) and sex-matched normal weight controls. Energy expenditure (EE) was determined using open-circuit indirect calorimetry at rest, both after a 12-h fast and after an oral sucrose load of 3 g/kg ideal body weight. Food-induced thermogenesis (FIT) was evaluated by computing the area under the curve of the EE response above resting energy expenditure (REE) during the first 3 h after the sucrose load, REE (kcal/day) was higher in the overweight patients (1,818 +/- 46 vs. 1,527 +/- 67; p = 0.002); REE standardized by fat-free mass (FFM) (kcal/kg FFM/day) was lower in obese children than in controls (35.2 +/- 1.0 vs. 44.9 +/- 1.9; p = 0.0001). A linear correlation between REE and FFM was evidenced in both controls and overweight subjects (r = 0.78 and 0.68, respectively; p = 0.05 and p < 0.001, respectively). Actual REE in the obese children was significantly lower than the value predicted by applying the regression equation of REE on FFM in controls to the actual FFM in obese children (paired t test; p = 0.003). FIT was identical in overweight and normal weight subjects, regardless of whether it was expressed in absolute value, as the percentage calorie intake, or standardized by FFM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Directional control of rapid arm movements: The role of the kinetic visual feedback system.

Examined how vision of initial, terminal, or complete arm trajectory affected the movement control and accuracy of 6 right-handed volunteers when the amplitude and directional task constraints were varied. Evidence was found for the significant contribution of vision during the initial phase of rapid pointing movements when this phase is under the control of the kinetic channel. Movements having directional requirements were more accurate when vision of the initial portion of the trajectory was available. Times-to-peak acceleration and velocity were shorter and their respective amplitudes were generally higher when vision was available for the 1st 3rd of the trajectory than when it was not. Vision of the entire trajectory did not yield better precision than when vision was available for the initial phase of the movements only. The data support the existence of 2 supportive visual feedback systems. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Toxicity of Phenolic Compounds Extracted from Bark Residues of Different Ages

In Quebec, Canada, industrial bark wastelands cover several hundred hectares of land. Bark residue that has piled up for decades tends to remain free of vegetation for years. To assess the revegetation potential of such sites, we sought to determine those factors responsible for poor plant growth. Phenolic compounds from fresh to 20-year-old bark residues were extracted with four solvents and quantified by high-performance liquid chromatography (HPLC). We simulated solutions (mixtures of standard phenolic compounds) to evaluate the potential toxic effects of phenolic compounds on the rhizobial growth, germination index, plant growth, nodule number, and nitrogen fixation activity of two legume species under laboratory conditions. The concentration of individual phenolic compounds varied from none detected to 350 μg/g bark residue. The extracted phenolic compounds differed among solvents and bark residues. The highest concentration of total phenolic compounds was from fresh bark; most of these were soluble in water or 0.1 M NaOH. For older bark residues, the total phenolic content depended on solvent strength, generally in the order of 2.0 M NaOH > 0.1 M NaOH = hot water > cold water. The biological activity of the simulated bark extracts was not established with the rhizobial growth inhibition test but with the germination index and rhizobium–legume symbiosis tests. With these, the toxicity of the simulated phenolic extracts decreased from fresh to the older bark residues. Plant dry weight, nodule number, and nitrogen fixation activity of vetch (Vicia sativa L.) were less negatively affected by high concentrations of phenolics than birdsfoot trefoil (Lotus corniculatus L.), although birdsfoot trefoil grew at lower concentrations. The rhizobium–legume symbiosis has potential for revegetating bark wastelands with less than 1 year old and older bark residues.     

Hierarchical porous silica membranes with dispersed Pt nanoparticles

Multifunctional silica membranes with a hierarchical porosity and containing dispersed Pt nanoparticles were prepared by an original one pot microwave-assisted sol–gel route. These membranes exhibit three porosity levels: interconnected micropores (<2 nm) in silica walls, isolated ordered mesopores (4 nm), and isolated macropores (70 nm). They were directly coated on tubular macroporous alumina supports without any intermediate mesoporous layer contrary to conventional membrane architectures. The isolated macropores and mesopores enable to increase the membrane permeability whereas the interconnected microporosity defines the membrane cut-off. The catalytic Pt nanoparticles (4 nm) mainly hosted in the mesoporous volume, are stabilised against undesirable agglomeration under working conditions. A first series of multifunctional membranes were prepared, in which preferential adsorption of hydrocarbon gases and efficient propene oxidation were evidenced. In order to avoid any possible interconnection between macropores, several strategies were investigated, which prevented sol infiltration in the macroporous support during the deposition process. These original multifunctional membranes are potentially attractive for gas separation and catalytic reactor applications.     

SHOP: A Method For Structure‐Based Fragment and Scaffold Hopping

We present a method for fragment/scaffold substitution based on protein–ligand interactions. This concept goes beyond bioisosteric replacement, which only uses the structure of the fragment to replace as query. The methodology is validated with more than 10 biological targets relevant for drug discovery.