Controversy and consensus regarding the use of cognitive ability testing in organizations.

Seven hundred three members of the Society for Industrial and Organizational Psychology indicated agreement or disagreement with 49 propositions regarding cognitive ability tests in organizations. There was consensus that cognitive ability tests are valid and fair, that they provide good but incomplete measures, that different abilities are necessary for different jobs, and that diversity is valuable. Items dealing with the unique status of cognitive ability were most likely to generate polarized opinions. A 2-factor model, classifying items as those reflecting societal concerns over the consequences of ability testing and those reflecting an emphasis on the unique status of "g," fit the data well, and these factors proved especially important for predicting responses to the more controversial items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

钢的连铸用保护渣的表征

在钢的连铸过程中,结晶器保护渣的性质强烈地影响着铸造的行为、钢的质量、以及连铸工艺的环境.本研究采用高温显微技术来研究保护渣的熔化行为,采用液滴测试方法来测定保护渣的熔化速率.结果表明:自由碳是控制保护渣熔化行为的主要因素.熔化速率随碳的反应能力的增加而增加,随着碳含量的减少而增加.     

Markov decision processes with delays and asynchronous cost collection

Markov decision processes (MDPs) may involve three types of delays. First, state information, rather than being available instantaneously, may arrive with a delay (observation delay). Second, an action may take effect at a later decision stage rather than immediately (action delay). Third, the cost induced by an action may be collected after a number of stages (cost delay). We de rive two results, one for constant and one for random delays, for reducing an MDP with delays to an MDP without delays, which differs only in the size of the state space. The results are based on the intuition that costs may be collected asynchronously, i.e., at a stage other than the one in which they are induced, as long as they are discounted properly.     

Ornithine decarboxylase transformation of NIH/3T3 cells is mediated by altered epidermal growth factor receptor activity

Ornithine decarboxylase (ODC) has been shown to be oncogenic in transfected NIH/3T3 cells overexpressing the enzyme from a heterologous promoter. These cells, designated as NODC-2 cells, acquire proliferative properties associated with tumorigenic transformation such as loss of contact inhibition, decreased population doubling time, anchorage-independent growth, and tumor production in nude mice. At least one of these parameters, loss of contact inhibition, remains dependent on elevated ODC levels. We have used these cells to investigate the molecular mechanisms by which ODC overexpression drives cell transformation and to examine the involvement of other proto-oncogene products in this process. An interaction between ODC overexpression and the epidermal growth factor receptor (EGF-R) was suggested initially by the elevation of both basal (300%) and ligand-induced (457%) EGF-R tyrosine kinase activities in NODC-2 cells compared to similarly treated control NLK cells. Disruption of EGF-R mediated signal transduction in NODC-2 cells both by treatment with tyrphostin-25 or by transfection with a vector expressing a dominant negative EGF-R mutant resulted in reacquisition of contact-inhibited growth and suppression of anchorage-independent, clonogenic growth in soft agar. We conclude that ODC-induced transformation of NIH/3T3 cells is mediated, at least partly, by alterations in EGF-R signal transduction activity.     

Phase Relations and Properties of Phases in the TlInSe2–TlPrSe2 System

The phase diagram of the TlInSe₂–TlPrSe₂ system was mapped out using differential thermal analysis and x-ray diffraction data. The system was found to contain a partial solid-solution series (0–10 mol % TlPrSe₂) and a quaternary compound of composition Tl₂InPrSe₄. The electrical conductivity, Hall coefficient, and thermoelectric power of TlPrSe₂ and Tl₂InPrSe₄ were measured in the temperature range 300–1100 K. The charge carriers in these compounds were shown to be scattered mainly by longitudinal acoustic phonons.     

Cohesive stresses and size effect in quasi-brittle materials

A novel approach to the derivation of Bažant’s size effect law is presented. Contrarily to the original Lagrangian derivation which hinged on energetic consideration, a Newtonian approach based on local stress intensity factors is presented. Through this approach, it is shown that Bažant’s size effect law is the first (and dominant) term in a series expansion for the nominal stress. Furthermore, analytical expressions forB are derived for selected specimen geometries.     

Current gain-Early voltage products in heterojunction bipolartransistors with nonuniform base bandgaps

The tradeoff between common-emitter current gain (β) and Early voltage (V_A) in heterojunction bipolar transistors (HBTs) where the bandgap varies across the base has been studied. The Early voltage depends exponentially on the difference between the bandgap at the collector side of the base and the largest bandgap in the base, allowing very high Early voltages with only very thin narrow bandgap regions. Using Si/Si_1-xGe_x/Si HBTs with a two-layer stepped base, βV_A products of over 100000 V have been achieved for devices with a cutoff frequency expected to be about 30 GHz     

Development of brief scales to monitor clients' constructions of change.

This article describes the development and validation of scales to measure clients' outcome optimism, perceived progress, and self-agency related to change in problems presented in therapy. In Study 1, initial confirmatory and subsequent exploratory factor analyses (N?=?257) identified effort and persistence as an additional unique factor and guided selection of items to measure the 4 constructs. In Study 2, confirmatory factor analysis of the revised scales with a new sample (N?=?93) confirmed the measurement model. Results of convergent and discriminant validity analyses generally were in the predicted directions. The Perceived Progress scale demonstrated criterion validity with changes in dyadic adjustment and family functioning. The Outcome Optimism and Self-Agency scales showed variability in their relationship to the Perceived Progress scale over the first 3 sessions of therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calcification of subcutaneously implanted collagens in relation to cytotoxicity,cellular interactions and crosslinking

In general, calcification of biomaterials occurs through an interaction of host and implanted material factors, but up to now the real origin of pathologic calcification is unknown. In this study we aimed to investigate incidence of calcification of (crosslinked) dermal sheep collagens (DSCs) with respect to their specific properties, during subcutaneous implantation in rats. Three types of DSCs were commercially obtained: non-crosslinked DSC (NDSC), and DSC crosslinked with glutaraldehyde (GDSC) and hexamethylenediisocyanate (HDSC). NDSC, HDSC and GDSC were (enzymatically) tissue culture pretreated to eliminate their cytotoxic products. Beside this, crosslinking methods were modified to optimize mechanical properties and to decrease cytotoxicity, which resulted in HDSC^* and GDSC^*. Furthermore, DSC was crosslinked by activation of the carboxylic groups, i.e. by means of acyl azide and carbodiimide, resulting in AaDSC and CDSC, respectively. After implantation of HDSCs and GDSCs a relation between cytotoxicity and calcification of crosslinked DSC could be made. No relation was found between cellular infiltration of DSCs and calcification. However, from the use of different types and modification of crosslinking methods it might be concluded that calcification is mainly related to stable crosslinks, i.e. to the chemical properties of the obtained material.     

A study of ionic defects in modified lead titanate ceramics

Pb_1–x Ca _x [(Co_0.5W_0.5)_0·05Ti_0.95]O₃ ceramics with x = 0.24, 0.30 and 0.35, are prepared by a solid state reaction of oxides. Deviations from nominal chemical compositions and formation of segregated phases different from modified lead titanate perovskites, are studied. Pyro- and non-pyroelectric currents excited in the material by a thermal wave are investigated and related to mobility of electrical charges in the materials.