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1.
Adv Health Sci Educ Theory Pract ; 11(3): 267-78, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16832709

RESUMO

Students inaccurately assess their own skills, especially high- or low-performers on exams. This study assessed whether regression effects account for this observation. After completing the Infection and Immunity course final exam (IIF), second year medical students (N = 143) estimated their performance on the IIF in terms of percent correct and percentile rank. Second year grade point averages (M2GPAs) were combined with the IIF results to form five subgroups: 1 = true-low (lowest third on both IIF and M2GPA, 2 = false-low (lowest third on IIF only), 3 = middle (neither lowest nor highest third on IIF), 4 = false-high (highest third on IIF only), 5 = true-high (highest third on IIF and M2GPA). The false-low and false-high groups were considered more susceptible to regression effects due to likely group misclassification. Differences between self-assessment and actual performance within each group and between the five groups were used to estimate what portion of observed differences is due to general tendencies versus regression effects. Results found that students accurately assessed their percent correct, but inaccurately assessed their percentile rank. No statistically significant differences existed between the true and false-low subgroups nor the true- and false-high subgroups. Percentages of mean differences suggest that while regression effects resulted in 50-75% over/under-estimates of scores by students who were misclassified, when they were merged with the true-low/high groups, they do not account for more than 14% of low performer over-estimates of their performance and high performer under-estimates of their performance. Accurate percent correct assessments and distorted percentile rank assessments are challenges in using instructional methods dependent on student self-assessments of their learning needs. Identifying and helping students with distorted perceptions of their test performances may be a key issue in such instructional approaches.


Assuntos
Interpretação Estatística de Dados , Avaliação Educacional/métodos , Percepção , Autoavaliação (Psicologia) , Estudantes de Medicina/psicologia , Humanos
2.
Theriogenology ; 64(8): 1809-22, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15921734

RESUMO

Preservation of DNA integrity is essential for protection of sperm quality. This study examined, with the use of comet assay, DNA fragmentation of rainbow trout (Oncorhynchus mykiss) spermatozoa subjected to UV irradiation (2,075 microW/cm(2), 0-15 min) or oxidative stress induced by hydrogen peroxide (0-20mM). Sperm motility and fertilizing ability were also measured. A dramatic increase in DNA fragmentation was recorded after 5 min UV irradiation but no significant changes in sperm motility were observed at this time. Longer irradiation resulted in a decrease in motility parameters and further increase of DNA fragmentation. UV irradiation caused a clear decrease in the percentage of eyed embryos and most of the embryos did not hatch. When highly diluted sperm suspensions (50,000-fold) were exposed to 0.1mM H(2)O(2) evident increase in DNA fragmentation was observed. On the other hand, when more concentrated sperm suspensions (diluted only 40-fold) were employed (in order to conduct motility and fertilization measurements at the same time) 1-20mM H(2)O(2) caused only moderate increase in DNA fragmentation and dose-dependent decline in sperm motility and fertilizing ability. This suggests that toxic effects of H(2)O(2) were primarily related to inhibition of sperm motility. Our results demonstrate that comet assay can be used for monitoring the effectiveness of fish sperm DNA inactivation by UV irradiation. Therefore, the comet assay together with sperm motility analysis can be applied in optimization works of gynogenetic procedures in fish. Lack of effectiveness of H(2)O(2) in inducing major DNA fragmentation suggests presence of mechanisms of antioxidative defense in rainbow trout spermatozoa.


Assuntos
Fragmentação do DNA , Fertilização , Peróxido de Hidrogênio/farmacologia , Oncorhynchus mykiss , Motilidade dos Espermatozoides , Raios Ultravioleta , Animais , Ensaio Cometa , Fragmentação do DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos da radiação , Fertilização/efeitos dos fármacos , Fertilização/efeitos da radiação , Masculino , Motilidade dos Espermatozoides/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos da radiação
4.
J Gen Intern Med ; 13(6): 410-3, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9669570

RESUMO

We surveyed employers of general internists at teaching hospitals to determine whether they prefer that new hires are graduates of general internal medicine (GIM) fellowships. We surveyed former GIM fellows who graduated between 1988 and 1994 to determine whether they found jobs with protected research time and whether the positions they found matched their expectations. Employers rated a GIM fellowship, among other criteria, as important for clinician-researchers, but not for clinician-educators. For graduates categorized as clinician-researchers (with more than 33% of their time protected for research), there was a good match between their actual time allocations for research and clinical work and what they recalled their expectations were when looking for a job. Clinician-educators had a marked discordance between actual time allocations for research and clinical work and their recollection of their expectations when looking for a job.


Assuntos
Emprego , Bolsas de Estudo , Medicina Interna , Coleta de Dados
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