Further explorations of perceptual speed abilities in the context of assessment methods, cognitive abilities, and individual differences during skill acquisition.

Measures of perceptual speed ability have been shown to be an important part of assessment batteries for predicting performance on tasks and jobs that require a high level of speed and accuracy. However, traditional measures of perceptual speed ability sometimes have limited cost-effectiveness because of the requirements for administration and scoring of paper-and-pencil tests. There have also been concerns about the validity of previous computer approaches to administering perceptual speed tests (e.g., see Mead & Drasgow, 1993). The authors developed two sets of computerized perceptual speed tests, with touch-sensitive monitors, that were designed to parallel several paper-and-pencil tests. The reliability and validity of the tests were explored across three empirical studies (N = 167, 160, and 117, respectively). The final study included two criterion tasks with 4.67 and 10 hours of time-on-task practice, respectively. Results indicated that these new measures provide both high levels of reliability and substantial validity for performance on the two skill-learning tasks. Implications for research and application for computerized perceptual speed tests are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of family of origin and adult romantic partners on romantic attachment security.

According to attachment theory, attachment style derives from social experiences throughout the life span. The authors tested this expectation by examining associations between the quality of observed interaction patterns in the family of origin during adolescence and self-reported romantic attachment style and observed romantic relationship behaviors in adulthood (ages 25 and 27). Family and romantic relationship interactions were rated by trained observers from video recordings of structured conversation tasks. Attachment style was assessed with items from D. W. Griffin and K. Bartholomew's (1994a) Relationship Scales Questionnaire. Observational ratings of warmth and sensitivity in family interactions were positively related to similar behaviors by romantic partners and to attachment security. In addition, romantic interactions characterized by high warmth and low hostility at age 25 predicted greater attachment security at 27, after controlling for attachment security at age 25. However, attachment security at age 25 did not predict later romantic relationship interactions after controlling for earlier interactions. These findings underscore the importance of close relationships in the development of romantic attachment security but do not indicate that attachment security predicts the quality of interactions in romantic relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

天津办公建筑空间设计因素节能分析与优化

为改善天津地区办公建筑空间节能效果,以点式高层办公楼为例,研究空间设计因素对建筑能耗的影响及优化节能设计方案.首先基于案例调研总结其空间设计因素的典型值或值域,建立典型模型;然后选择6项空间设计因素展开分析,包括平面长宽比、建筑朝向、标准层面积、层高、窗墙比、外窗水平遮阳板长度,依次通过正交试验和列表法安排DesignBuilder能耗模拟试验,从而很快地获得优化节能设计方案.模拟试验考虑两种围护结构构造类型,分别代表常规构造和被动房构造.试验结果表明:层高与窗墙比构成建筑能耗的两项重要影响因素,其次为标准层面积、平面长宽比与建筑朝向、外窗水平遮阳板长度;优化节能设计方案中各因素的取值为:平面长宽比2∶1,建筑朝向南向,标准层面积1 024 m~2,层高3.6 m,窗墙比0.3,外窗水平遮阳板长度300 mm.经过试验设计与模拟分析,实现天津地区点式高层办公楼空间节能效果最大化,为该地区办公建筑节能设计提供参考.     

Properties of poly(ethylene terephthalate) prepared by high-pressure extrusion in a capillary die

The procedure of Southern and Porter has been used to prepare poly(ethylene terephthalate) segments by high-pressure extrusion in an Instron capillary rheometer at temperatures from 245° to 265°C. X-Ray measurements of crystalline orientation along the axis of long-growth segments showed that segment properties were controlled by the time-dependent crystallization of polymer melt in the rheometer reservoir. During the initial stage of extrusion, a highly oriented, translucent segment was generated by flow-induced crystallization. However, formation of the translucent morphology eventually stopped, and thereafter a poorly oriented, opaque segment was generated by solid-state extrusion. From wide- and small-angle x-ray scattering, differential scanning calorimetry, and density measurements, it was determined that the most perfect morphologies were prepared at an extrusion temperature of 265°C. In addition to having the highest degree of crystalline orientation, translucent segments extruded at 265°C have a peak melting point of 267°C and a crystallinity value of 62%. Hot-stage optical microscopy showed that the translucent segments contained axially aligned fibrous crystals whose birefringence persisted to 290°C. The exceptional thermal stability of the segments was corroborated by the results of shrinkage tests at temperatures near the melting point; even after 1 hr at 260°C, the shrinkage did not exceed 7%. The accumulated evidence suggests that the translucent segments contain an extended-chain component.     

Microglial Cell Activation Increases Saturated and Decreases Monounsaturated Fatty Acid Content,but Both Lipid Species are Proinflammatory

Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation.     

Day Labourers, Unemployment and Socio-economic Development in South Africa

One of the most visible forms of unemployment is the men who stand at the side of the road or on corners daily, waiting for any job that may come their way. It is estimated that there are nearly 1,000 places in South Africa where a minimum of about 45,000, mostly black African men, stand, waiting to be picked up. The South African space economy is characterised by an uneven distribution of economic activities. International empirical studies have shown that there is a geographical or spatial coincidence between levels of unemployment and levels of gross domestic product per capita. The first objective of this article is to highlight some of the basic demographic dynamics of day labourers. The second is to investigate the spatial distribution of and the relationship between day labourers, unemployment and the general level of socio-economic development in South Africa. Day labourers share a number of common characteristics, but there were also obvious differences in their morale and spirit. The analyses showed that there is also a general spatial coincidence between levels of socio-economic development and the numbers of day labourers in South Africa, with a relatively high correlation coefficient between the two.     

Adolescents' theories about the development of their relationships with parents.

Assessed 100 undergraduates' developmental theories about their affective relationships with their parents, using a retrospective method. Ss used drawings and questionnaire ratings to portray their relationships with parents at 5 points between infancy and the present. From infancy to their current age, Ss portrayed their relationships in 2 major ways: They perceived themselves as gaining in responsibility, dominance, independence, and similarity from infancy to the present, whereas they portrayed their parents as experiencing a decline on these dimensions. For variables indicating closeness and love, however, there was a striking discontinuity in these linear trends: Although Ss perceived linear trends from infancy to adolescence, they depicted their current relationships as involving a great deal more love and closeness. They also portrayed their relationships with mothers and fathers somewhat differently. More responsibility was felt toward the mothers and they were portrayed as especially friendly, but Ss felt more similar to their fathers, whom they perceived as dominant. Results suggest that late adolescents construct theories of the affective components of their relationships with their parents to serve the needs of separation while maintaining a close affective tie to the parents. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adaptive Control for Robotic Rebar Bending

Abstract: Computers are becoming essential tools for integrating design, planning, fabrication, and construction. Computer-controlled construction equipment is poised to receive information from data generated in the design phase. The robotic execution of construction operations, however, depends on complex models for autonomous and intelligent control. This paper introduces a strategy for the robotic bending of rebar and presents the results of experimental work with an actual testing facility. Mechanical properties and behavior of rebar are examined to develop rules for control. Focus is placed on exploring the dynamics between the bender and steel bars. The concepts of impedance, admittance, and compliance of both the machine and the environment will be discussed in the context of control strategy development.     

Dichlorvos space treatment for protection of packaged flour against insect infestation

Dichlorvos vapor was applied weekly from dichlorvos-impregnated resin pellets into 42·5 m³ (1500 ft³) chambers. The chambers contained insect-free flour packaged in cotton sheeting, and in multiwall paper bags stacked at various distances from similar bags of infested flour. The dichlorvos concentration attained in the chambers from the weekly application of vapor was about 3 μg/1. After 5 months of storage, the number of insects found in the flour indicated that the dichlorvos applications retarded the infestation of flour in cotton bags and prevented the infestation of flour in the multiwall paper bags. Chemical analysis showed that dichlorvos residues were less than 0·1 ppm in the flour and, in general, less than 1·1 μg/dm² (10 μg/ft²) on the packaging materials.