Interpretation of expansion curves of concrete subjected to accelerated alkali-aggregate reaction (AAR) tests

The examination of several long-term expansion results for concretes subjected to accelerated alkali-aggregate reaction (AAR) tests shows that, in some cases, the expansion continues for a long time after AAR has stopped. For these cases, all the concrete swelling is certainly not only caused by AAR, and the continuation of the expansion probably reveals the swelling behavior of concrete when it is conserved in saturated moisture conditions. Considering that this swelling is not negligible compared to the limit expansions fixed by standard AAR tests (2×10⁻⁴ at 90 days for the French performance test), it becomes important to evaluate it in order to avoid the inappropriate rejection of an aggregate.     

Blockade of NMDA receptors 2A subunit in the dorsal striatum impairs the learning of a complex motor skill.

Accumulating evidence proposes that the striatum, known to control voluntary movement, may also play a role in learning and memory. Striatum learning is thought to require long-lasting reorganization of striatal circuits and changes in the strength of synaptic connections during the memorization of a complex motor task. Whether the ionotropic glutamate receptor N-methyl-D-aspartate (NMDAR) contributes to the molecular mechanisms of these memory processes is still unclear. The aim of the present study was to investigate the role of striatal NMDAR and its subunit composition during the learning of the accelerating rotarod task in mice. To this end, we injected directly into the dorsal striatum of mice, via chronically implanted cannula, the NMDAR channel blocker MK-801 as well as the NR2A and NR2B subunit-selective antagonists NVP-AAM077 and Ro 25-6981, respectively, before rotarod training. There was no effect in the motor performances of mice treated with 1.0 μg/side of MK-801, 0.1 μg/side of NVP-AAM077, or 5 and 10 μg/side of Ro 25-6981. In contrast, injections of 2.5 and 5 μg/side of MK-801 or 0.5 and 1 μg/side of NVP-AAM077 impaired motor learning at Day 3 and 8. Interestingly, treatments with MK-801 and NVP-AAM077 did not alter the general motor capacities of mice as revealed by the stepping, wire suspension, and pole tests. Our study demonstrates that the NMDAR of the dorsal striatum contributes to motor learning, especially during the slow acquisition phase, and that NR2A subunits play a critical role in this process. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A Similarity-Based Aspect-Graph Approach to 3D Object Recognition

This paper describes a view-based method for recognizing 3D objects from 2D images. We employ an aspect-graph structure, where the aspects are not based on the singularities of visual mapping but are instead formed using a notion of shape similarity between views. Specifically, the viewing sphere is endowed with a metric of dis-similarity for each pair of views and the problem of aspect generation is viewed as a segmentation of the viewing sphere into homogeneous regions. The viewing sphere is sampled at regular (5 degree) intervals and the similarity metric is used in an iterative procedure to combine views into aspects with a prototype representing each aspect. This is done in a region-growing regime which stands in contrast to the usual edge detection styles to computing the aspect graph. The aspect growth is constrained such that two aspects of an object remain distinct under the given similarity metric. Once the database of 3D objects is organized as a set of aspects, and prototypes for these aspects for each object, unknown views of database objects are compared with the prototypes and the results are ordered by similarity. We use two similarity metrics for shape, one based on curve matching and the other based on matching shock graphs, which for a database of 64 objects and unknown views of objects from the database give a recall rate of (90.3%, 74.2%, 59.7%) and (95.2%, 69.0%, 57.5%), respectively, for the top three matches; cumulative recall rate based on the top three matches is 98% and 100%, respectively. The result of indexing unknown views of objects not in the database also produce intuitive matches. We also develop a hierarchical indexing scheme to prune unlikely objects at an early stage to improve the efficiency of indexing, resulting in savings of 35% at the top level and of 55% at the next level, cumulatively.     

Photocontrolled living polymerizations

Living polymerizations involve the creation of polymer chains without significant irreversible chain transfer or chain termination. Such processes are widely used to access well-defined macromolecular materials with controlled architectures, such as block and star polymers. Although this concept was first realized for anionic polymerizations in the 1950s, many key recent advances have been made, most notably in the area of radical polymerization. Here, we report a living photopolymerization that involves photoexcited monomers. Exposure of metal-containing ferrocenophane monomers to Pyrex-filtered light from a mercury lamp (lambda>310 nm) or to bright sunlight in the presence of an anionic initiator leads to living polymerizations, in which the conversion and molecular weight of the resulting polymer can be controlled by the irradiation time. Photoirradiation selectively weakens the iron-cyclopentadienyl bond in the monomer, allowing the use of moderately basic and highly functional-group-tolerant initiators. The polymerization proceeds through attack of the initiator and propagating anion on the iron atom of the photoexcited monomer and, remarkably, the polymerization rate decreases with increasing temperature. Block copolymer formation is possible when the light source is alternately switched on and off in between sequential addition of different monomers, providing unprecedented, photocontrolled access to new types of functional polymers.     

Usage patterns and misuse rates of automatic seat belts by system type

This study examined seat belt usage in North Carolina by drivers of 4,151 late model cars equipped with a variety of restraint system types. We measured usage by restraint type (automatic belt, air bag, manual belt), by make/model and by driver characteristics (age, sex, and race). Usage ranged from a high of 94.2% for motorized shoulder belts (but with only 28.6% lap belt usage in these cars) to 73.9% usage of manual lap/shoulder belts in cars equipped with air bags. Various types of misuse of the shoulder belt (e.g. excessive slack, detachment from the door, placement under the arm) were observed in nearly 6% of the sample.     

Telephone surveys as an alternative for estimating prevalence of mental disorders and service utilization: a Montreal catchment area study

BACKGROUND: Large-scale mental health surveys have provided invaluable information regarding the prevalence of specific mental disorders and service use for mental health reasons. Unfortunately, because vast surveys conducted face to face are very costly, many countries and provinces do not embark upon this path of research, thus depriving themselves of a rich source of data useful for service planning. METHOD: As an alternative, the authors undertook a telephone survey with a sample of 893 residents from a Montreal catchment area. Mental disorders were assessed by the Composite International Diagnostic Interview Simplified (CIDIS), an instrument especially designed to be used in mail or telephone surveys. Service utilization was measured by an instrument similar to those used in recent large Canadian or American surveys. RESULTS: The prevalence rate for any mental disorder was lower in this study than in some large-scale epidemiological surveys reviewed. This could be explained by methodological differences, such as number of disorders covered and period of reference. With regard to specific mental disorders, results appeared very similar to those of other studies. Concerning service utilization, rates tended to be higher than in other studies, and this finding could reflect real differences between Quebec and other Canadian provinces or the United States. CONCLUSIONS: Aside from being lower in cost, telephone surveys can yield results comparable to those obtained in large-scale epidemiological surveys conducted by means of face-to-face interviews.     

L'influence de l'approche psychothérapeutique et de l'expérience professionnelle sur les attentes des thérapeutes.

Evaluated the influence of theoretical orientation and professional experience on therapists' expectancies. In an analog study, 199 registered psychologists were asked to read a case history of a hypothetical client and to answer an 8-point Likert type expectancies inventory. From a 61-item inventory, 3 types of therapist expectancies were examined: diagnostic (anticipations of client need), prognostic (assessments of probable client outcomes), and process expectancies (anticipated use of directiveness and interpretations). A MANOVA with unweighted means was performed. Use of a Wilks lambda criterion produced no significant interaction effects. The main effect for Professional Experience was not significant. However, a significant main effect was found for Therapist Theoretical Orientation. Discriminant function analysis clarified the meaning of these results. Group centroids indicated that behaviorists expect to be more active and anticipate fewer client needs than psychoanalysts and phenomenologists. Psychoanalysts expect to be less active and anticipate more client needs, while phenomenologists expect to be moderately active and anticipate moderate client needs. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vulnérabilité à la dépression chez les femmes victimes de violence conjugale: Contribution de la dépendance et l'autocritique.

The main purpose of this study is to evaluate the moderating effect of conjugal violence on the relationship between Dependency, Self-Criticism and depression. It investigates whether the contribution of personality to the severity of depressive symptoms diminishes as conjugal violence reported by women increases. Participants (N = 151) completed the Depressive Experiences Questionnaire, the Conflict Tactics Scales - II and two measures of depressive symptoms. The results of hierarchical hierarchical regression analyses, including quadratic interactions, indicate different patterns for each of the two personality dimensions. The main hypothesis is confirmed for Dependency: Dependency is related to the severity of depressive symptoms when violence is "moderate." However, the strength of this relationship diminishes as violence increases, the severity of the traumatic situation taking precedence over personal dispositions. On the other hand, results indicate that Self-Criticism adds up to the impact of conjugal violence on depressive symptoms. The discussion underlines the importance of integrating individual factors in the study of depression in women with a history of conjugal violence. It also underlines implications for the operationalisation of negative events likely to generate depressive affect in Dependent and Self-Critical individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of demographic and clinical characteristics in predicting length of psychiatric hospital stay: A final evaluation.

The literature on patient demographic and clinical characteristics as predictors of length of psychiatric hospital stay suggests that investigators have been unsuccessful in producing a prediction model using this information to account for any substantial criterion variance. The present study maximized predictions of length of hospital stay by using a more powerful statistical procedure and an expanded number of predictor variables. Data were obtained on 877 patients who were discharged from psychiatric hospitals in 1980. Results show that despite these improvements, the resulting proportion of variance was moderate at best. It is concluded that increases in similar information are unlikely to improve predictions. The use of untapped variables (e.g., management philosophies and politically based information) is discussed. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Destabilization of cubic-stabilized zirconia electrolyte induced by boron oxide under reducing atmosphere

The stability of yttria-stabilized zirconia (YSZ) and scandia-stabilized zirconia (ScSZ) electrolytes against boron oxide was examined. Boron oxide was painted on the polished surface of YSZ and ScSZ and annealed at 1273 K for 100 h under wet hydrogen flowing condition. The X-ray diffractometry, scanning electron microscopy/energy dispersive X-ray analysis, and Raman studies revealed that formation of Y₂O₃ and Sc₂O₃ occurred on YSZ and ScSZ surfaces contacting the boron oxide, but rare earth borates were not observed. The surface of electrolytes around precipitated particles became rough and phase transformation was confirmed from the cubic to the tetragonal or the monoclinic phases due to stabilizer removal from cubic zirconia. It has been also verified that small amounts of zirconium and yttrium were transported from the electrolyte to the gas phase via boron component. This destabilization effect induced by boron oxide was more serious for ScSZ than for YSZ. A destabilization mechanism under wet hydrogen atmosphere is proposed based on pseudo ternary phase diagrams for the YO_1.5–BO_1.5–ZrO₂ system and the ScO_1.5–BO_1.5–ZrO₂ system and thermodynamic considerations.