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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) 相似文献
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Fast atom bombardment ionization with tandem mass spectrometry of both positive and negative ions is a useful technique for the identification of intact glycerophosphoethanolamine (GPE) phospholipids, providing information as to polar head group and fatty acyl substituents. In the identification of GPE molecular species, positive ion neutral loss scanning for 141 units was attempted to confirm the presence of the phosphoethanolamine polar head group. This scan was found to discriminate against the abundant subclass of phospholipids having an 1-O-alk-1'-enyl linkage, termed plasmalogens, as well as 1-O-alkyl ether species. The neutral loss process is suggested to involve attack of a carbonyl oxygen from either sn-1 or sn-2 on the sn-3 methylene carbon with loss of neutral phosphoethanolamine. Using FAB/MS/MS alone, it is not possible to differentiate between plasmalogens and other 1-O-alkyl ether molecular species having the same molecular weight. The combination of mild acid hydrolysis, which selectively hydrolyzes the labile 1-O-alk-1'-enyl bond, with subsequent FAB/MS/MS distinguished species of these distinct subclasses. Using these techniques and precursor ion scans for the arachidonoyl carboxylate anion, m/z 303, the arachidonic acid containing glycerophosphoethanolamine molecular species were identified and the relative abundance of arachidonoyl plasmalogen, alkylacyl, and 1,2-diacyl GPE molecular species in the human polymorphonuclear leukocyte (neutrophil) was determined to be 75.4%, 12.1%, and 12.5%, respectively. These values were not significantly different from that reported in the literature using conventional methodology. 相似文献
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This paper investigates the effect of the waterproofing sleeve on the calibration of kilovoltage photon beams (50-300 kV). The sleeve effect correction factor, ps has been calculated using the Monte Carlo method as the ratios of the air kerma in an air cavity of a cylindrical chamber without the waterproofing sleeve to that with a sleeve. Three sleeve materials have been studied, PMMA, nylon and polystyrene. The calculations were carried out using the EGS4 (Electron Gamma Shower version 4) code system with the application of a correlated-sampling variance-reduction technique. The results show that the sleeve correction factor for 1-mm thick nylon and polystyrene sleeves, ps varies from 0.992 to 1.000 and from 0.981 to 1.000, respectively, for the same beam quality range. The ps factor varies with sleeve thickness, beam quality and phantom depth. No significant dependence of the ps factor on field size and source-surface distance has been found. Measurements for PMMA, nylon and polystyrene sleeves of various thicknesses have also been carried out and show excellent agreement with Monte Carlo calculations. 相似文献
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P Dhordain O Albagli RJ Lin S Ansieau S Quief A Leutz JP Kerckaert RM Evans D Leprince 《Canadian Metallurgical Quarterly》1997,94(20):10762-10767
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Evaluation of humoral immune responses in cattle grazing endophyte-infected or endophyte-free fescue
RL Rice DJ Blodgett GG Schurig WS Swecker JP Fontenot VG Allen RM Akers 《Canadian Metallurgical Quarterly》1997,59(3-4):285-291
Anecdotal reports suggest cattle with fescue toxicosis may not respond to vaccination and thus, experience increased incidence of Bovine Respiratory Disease Complex (BRDC) when shipped to feedlots. Fescue toxicosis causes hypoprolactemia in cattle. Hypoprolactemia decreases humoral immune responses in mice. Therefore, a study was conducted to compare the magnitude of primary and secondary humoral immune responses against specific antigens in cattle grazing endophyte-infected or endophyte-free fescue. Angus steers were blocked by weight and allocated into four groups. Two groups grazed endophyte-infected (EI) fescue and the other two groups grazed endophyte-free (EF) fescue. All steers were injected IM on d 0 and 21 with lysozyme without adjuvant and concanavalin. A (Con A) with sheep red blood cells (SRBC) in incomplete adjuvant of Freund. Steers were bled on days 0, 21 and 35 post-vaccination. Average daily gains (ADG), alkaline phosphatase (ALP) activity, cholesterol concentrations, rectal temperatures, and serum prolactin concentrations were measured to confirm fescue toxicosis in steers grazing EI fescue. Antibodies to Con A and SRBC were determined by ELISA and hemagglutination assay, respectively. The ADG were decreased for the EI group during the first month. Rectal temperature were elevated and serum prolactin concentrations were decreased in the EI group. Cholesterol and ALP concentrations also were decreased in the EI group. Primary and secondary immune responses against Con A tended to be increased and were increased against SRBC in the EI group. Antibodies against lysozyme were not induced in either group. In conclusion, cattle grazing EI fescue mounted similar humoral immune responses to vaccination, despite hypoprolactemia, as cattle grazing EF fescue. Increases in bovine respiratory disease in cattle maintained on EI fescue probably is not associated with lack of humoral immune response to vaccination protocols as a result of fescue toxicosis. 相似文献