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991.
Leff SS Thomas DE Shapiro ES Paskewich B Wilson K Necowitz-Hoffman B Jawad AF 《Journal of school violence》2011,10(2):165-184
The climate of school classrooms, shaped by a combination of teacher practices and peer processes, is an important determinant for children's psychosocial functioning and is a primary factor affecting bullying and victimization. Given that there are relatively few theoretically-grounded and validated assessment tools designed to measure the social climate of classrooms, our research team developed an observation tool through participatory action research (PAR). This article details how the assessment tool was designed and preliminarily validated in 18 third-, fourth-, and fifth-grade classrooms in a large urban public school district. The goals of this study are to illustrate the feasibility of a PAR paradigm in measurement development, ascertain the psychometric properties of the assessment tool, and determine associations with different indices of classroom levels of relational and physical aggression. 相似文献
992.
Kenneth F. Greene 《American journal of political science》2011,55(2):398-416
Despite ample evidence of preelection volatility in vote intentions in new democracies, scholars of comparative politics remain skeptical that campaigns affect election outcomes. Research on the United States provides a theoretical rationale for campaign effects, but shows little of it in practice in presidential elections because candidates’ media investments are about equal and voters’ accumulated political knowledge and partisan attachments make them resistant to persuasive messages. I vary these parameters by examining a new democracy where voters’ weaker partisan attachments and lower levels of political information magnify the effects of candidates’ asymmetric media investments to create large persuasion effects. The findings have implications for the generalizability of campaign effects theory to new democracies, the development of mass partisanship, candidate advertising strategies, and the specific outcome of Mexico's hotly contested 2006 presidential election. Data come primarily from the Mexico 2006 Panel Study. 相似文献
993.
We develop a model of intraparty candidate selection under partisan electoral competition and voter uncertainty. Candidates for office belong to parties, which are factions of ideologically similar candidates. Each party’s candidate for a general election can be selected either by a “centralized” mechanism that effectively randomizes over possible candidates or by voters in a primary election. The electorate cares about ideology and valence, and both primary and general elections may reveal candidate valences. Our main theoretical result is that while primaries raise the expected quality of a party’s candidates, they may hurt the ex ante preferred party in a competitive electorate by increasing the chances of revealing the opposing party’s candidates as superior. Thus, primaries are adopted in relatively extreme districts where a clear favorite party exists. An empirical analysis of the adoption of direct primaries and the competitiveness of primary elections across U.S. states supports these predictions. 相似文献
994.
This article uses data from the 2008 Cooperative Congressional Election Study to explain weak support for public financing of congressional campaigns. Previous studies lack theory to explain variation in support and use a flawed measure of the dependent variable. We argue that low support reflects a failure resulting from a collective action dilemma. Citizens desire a campaign finance system that weans politicians from private donors, but are unwilling to pay a small amount in taxes to support public financing. In contrast to conventional wisdom, we show that support for public financing is highest among those perceived to benefit the most from the current system. Our results suggest that most Americans would rather not pay for politics, and that reform proposals must avoid incurring transparent costs on individual citizens to pay for reform. 相似文献
995.
Richard F. Potthoff 《Public Choice》2011,148(1-2):67-86
For a single-winner multi-candidate election, it is broadly accepted that the Condorcet candidate (if one exists) should win. Voting systems do not always elect the Condorcet winner. Public opinion polls are not generally designed to try to identify a Condorcet candidate. They could easily be constructed to do so, however. The resulting process may be called Condorcet polling, for which various designs are presented herein. Information from Condorcet polling may enable some voters, under a plurality or runoff system, to bring about an outcome they prefer by voting strategically for the Condorcet candidate when they would not otherwise do so. 相似文献
996.
997.
3'-Hydroxystanosolol detection in biological fluids at pg levels by gas chromatography/tandem mass spectrometry is described. Gas chromatography/high resolution mass spectrometry results can be confirmed with gas chromatography/tandem mass-spectrometry. 相似文献
998.
Papin F Clarot F Vicomte C Gaulier JM Daubin C Chapon F Vaz E Proust B 《Forensic science international》2007,166(2-3):85-90
Superwarfarin exposure is a growing health problem, described in many countries. The authors report a case of suspicious chlorophacinone poisoning with a problematic diagnosis. They review the literature and discuss particularities of anticoagulant rodenticide intoxication, as well as the apparent contradiction between anticoagulant intoxication and lethal thrombosis. 相似文献
999.
Lociciro S Hayoz P Esseiva P Dujourdy L Besacier F Margot P 《Forensic science international》2007,167(2-3):220-228
Optimisation and harmonisation of analytical and statistical methodology have been carried out between two forensic laboratories (Lausanne, CH and Lyon, F) in order to provide drug intelligence for cross-border cocaine seizures. The aim was to improve the gas chromatographic analysis of cocaine samples for profiling. Some important validation parameters were tested to verify the developed method and demonstrate its profiling capacity: the selectivity of the method with retention time reproducibility, the choice of a derivatisation agent improving the chromatography (MSTFA, BSA, TMSI and BSTFA+TMCS 1%), the cutting agents influence (matrix effect), the influence of the sample storage conditions and the sample quantity to weigh for analyses. Eight main alkaloids, which represent the sample signature, have been selected: ecgonine methyl ester, ecgonine, tropacocaine, benzoylecgonine, norcocaine, cis- and trans-cinnamoylcocaine and 3,4,5-trimethoxycocaine. Their stability in the solvent used (CHCl(3)/pyridine) was demonstrated. In order to reach the final objective, which is the comparison of samples seized and analyzed in two different laboratories, the harmonisation of the profiling method between the two laboratories had to be ensured and is the subject of ongoing research. 相似文献
1000.
Strelova OIu Vozheva AB Slonimskaia EA Strelkova LF 《Sudebno-meditsinskaia ekspertiza》2007,50(3):31-33
The authors present a method of hingamine identification in non-biological substances (tablets, powder, syringes) and biological fluids (blood, urine). Isolation was made with chloroform in pH 10. Identification was conducted with thin-layer chromatography, gas chromatography/mass-spectrometry, high-performance liquid chromatography, spectrophotometry in UV region. The quantity was estimated with spectrophotometry in UV region, high-performance liquid chromatography and high-performance thin-layer chromatography. The results of the three methods are comparable. 相似文献