31 research outputs found
Novel Analytical Study For The Charge-Transfer Reactions Of Omeprazole With 2,3-Dichloro-Naphthoquinone And 2,3,5,6-Tetrabromo- 1,4-Benzoquinone: Application For The Development Of Microwell Assay Of Omeprazole
Novel analytical study was performed in order to develop and validate new high-throughput microwell-based spectrophotometric assays for determination of omeprazole (OMZ) in its pharmaceutical formulations. The proposed assays were based on the charge-transfer (CT) reaction of OMZ with 2,3-dichloronaphthoquinone (DCNQ) and 2,3,5,6-tetrabromo-1,4-benzo-quinone (BROM). In the present study, the CT reactions was carried out in microwell plates as reaction vessels in order to increase the automation of the assays and the efficiency of its use in quality control laboratories (QCLs). All factors affecting the CT reactions were carefully studied, and the conditions were optimized. Kinetics and stoichiometry of the CT reactions were investigated, and the mechanism was postulated. Activation energy of the CT reactions was determined and found to be 13.87 and 16.27 Kcal mol−1 for the reaction of OMZ with DCNQ and BROM, respectively. The initial rate and fixed time methods were applied for generating the calibration graphs for determination of OMZ concentrations. Under the optimum conditions, the linear range was 0.145 – 1.45 x 10-4 and 1.45 – 7.25 x 10-4 M with LOD of 0.6 and 6.0 microgram ml-1 for DCNQ and BROM, respectively. Analytical performance of the proposed methods, in terms of accuracy and precision, was statistically validated and the results were satisfactory; RSD was <2.8% for both repeatability and reproducibility. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms and the recovery results (98.64 – 100.6 ± 0.25 -2.74 %) were comparable with those of the reported method. The developed method may provide a safer and economic tool for the analysis of OMZ in QCLs
Assessing the Incidence and Wage Effects of Overeducation Among Italian Graduates Using a New Measure for Educational Requirements
A relational model of perceived overqualification : the moderating role of interpersonal influence on social acceptance.
Theories of perceived overqualification have tended to focus on employees’ job-related responses to account for effects on performance. We offer an alternative perspective and theorize that perceived overqualification could influence work performance through a relational mechanism. We propose that relational skills, in the form of interpersonal influence of overqualified employees, determine their tendency to experience social acceptance and, thus, engage in positive work-related behaviors. We tested this relational model across two studies using time-lagged, multisource data. In Study 1, the results indicated that for employees high on interpersonal influence, perceived overqualification was positively related to self-reported social acceptance, whereas for employees low on interpersonal influence, the relationship was negative. Social acceptance, in turn, was positively related to in-role job performance, interpersonal altruism, and team member proactivity evaluated by supervisors. In Study 2, we focused on peer-reported social acceptance and found that the indirect relationships between perceived overqualification and supervisor-reported behavioral outcomes via social acceptance were negative when interpersonal influence was low and nonsignificant when interpersonal influence was high. The implications of the general findings are discussed
A parametric control function approach to estimating the returns to schooling in the absence of exclusion restrictions: an application to the NLSY
Overeducation e undereducation no Brasil: incidência e retornos
Nos paÃses desenvolvidos, a literatura acerca da sobreeducação encontra-se em expansão. Há vários autores preocupados com a existência de diferenças entre os requisitos educacionais das ocupações e a escolaridade possuÃda pelos indivÃduos e os seus efeitos. O objetivo deste artigo é acrescentar evidências a essa literatura, avaliando a incidência e os retornos da sobreeducação e da subeducação no Brasil, nas Grandes Regiões e no Estado de São Paulo. Também foram analisadas as diferenças por gênero e por grande grupo ocupacional. Foram utilizados dados do Censo de 2000 e da Classificação Brasileira das Ocupações de 2002. Entre as regiões, os nÃveis de adequação oscilaram entre 25% e 31% e os de sobreeducação entre 14% e 19%. A região Sudeste apresentou a maior taxa de adequação e a região Sul a maior taxa de sobreeducação. O Nordeste apresentou a mais alta subeducação, sendo que quase 60% dos trabalhadores encontravam-se nesta condição. Relativamente aos retornos, a comparação entre os resultados de homens e mulheres evidenciou que o retorno de ser sobreeducada era de 13,9%, enquanto o de ser sobreeducado era de 12,1%. Verificamos, também, no caso dos homens, que o retorno da sobreeducação é maior nas regiões Centro-Oeste (12,7%) e Sudeste (12,4%). No caso das mulheres, constatamos que as duas regiões de maior dinamismo econômico - Sudeste e Sul - apresentaram menores retornos da sobreeducação (13,6% e 12,1%, respectivamente).<br>The overeducation literature is increasing in developed countries. Several authors have estimated the education-occupation mismatch as well as its effects on individuals' earnings. The objective of this article is to add evidences to this literature, evaluating the incidence and the returns for overeducation and undereducation in Brazil, Regions and São Paulo State. We also focus on gender and occupational differences. Data is taken from Census 2000 and the Brazilian Occupational Titles (CBO) 2002. Regarding regional pattern, the proper-match level has oscillated between 25% and 31%. The level of overeducation was between 14% and 19%. The Southeast region presented the highest tax of proper-match and the South region presented the highest tax of overeducation. The Northeast region presented highest undereducation level (almost 60%). As far as the returns are concerned, the return for women overeducated was 13.9%, while the same rate for men was 12.1%. The return for men overeducated was higher in Center-West (12.7%) and Southeast (12.4%). The women overeducated return was lower in the two most dynamic regions: Southeast and South (13.6% and 12.1%, respectively)
Overeducation in Developing Economies: How Can We Test for it, and What Does it Mean?
In the absence of data measuring the number of years of schooling required to perform particular jobs, we propose a new approach to testing for overeducation. Overeducation is confirmed by rising education levels in menial jobs that offer very low returns to education. Overeducation is deemed a systemic problem if these jobs absorb a growing share of the educated labor force. Normatively, overeducation should sometimes be seen as a shortage of skilled jobs, not as a surplus of educated workers. We use a decomposition of the returns to education to clarify the distinction between equity and efficiency rationales for expanding access to education when returns to education are low. We find substantial evidence of overeducation in the Philippines, mild evidence of it in India, and none in Thailand