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861.
PL Carr AS Ash RH Friedman A Scaramucci RC Barnett L Szalacha A Palepu MA Moskowitz 《Canadian Metallurgical Quarterly》1998,129(7):532-538
BACKGROUND: Studies have found that female faculty publish less, have slower career progress, and generally have a more difficult time in academic careers than male faculty. The relation of family (dependent) responsibilities to gender and academic productivity is unclear. OBJECTIVE: To describe dependent responsibilities by gender and to identify their relation to the aspirations, goals, rate of progress, academic productivity, and career satisfaction of male and female medical school faculty. DESIGN: 177-item survey questionnaire. SETTING: 24 randomly selected medical schools in the contiguous United States. PARTICIPANTS: 1979 respondents from a probability sample of full-time academic medical school faculty. MEASUREMENTS: The main end point for measuring academic productivity was the total number of publications in refereed journals. Perceived career progress and career satisfaction were assessed by using Likert scales. RESULTS: For both male and female faculty, more than 90% of time devoted to family responsibilities was spent on child care. Among faculty with children, women had greater obstacles to academic careers and less institutional support, including research funding from their institutions (46% compared with 57%; P < 0.001) and secretarial support (0.68 full-time equivalents compared with 0.83 full-time equivalents; P = 0.003), than men. Compared with men with children, women with children had fewer publications (18.3 compared with 29.3; P < 0.001), slower self-perceived career progress (2.6 compared with 3.1; P < 0.001), and lower career satisfaction (5.9 compared with 6.6; P < 0.001). However, no significant differences between the sexes were seen for faculty without children. CONCLUSIONS: Compared with female faculty without children and compared with men, female faculty with children face major obstacles in academic careers. Some of these obstacles can be easily modified (for example, by eliminating after-hours meetings and creating part-time career tracks). Medical schools should address these obstacles and provide support for faculty with children. 相似文献
862.
PURPOSE: To determine if runners have an increased prevalence of marrow edema in the foot and ankle compared with nonrunners at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Ankles and feet were imaged in 20 runners and 12 nonrunners with a fast short inversion time inversion-recovery sequence at 1.5 T. Edema within each bone was graded from 0 (no edema) to 3 (severe edema). Total scores for each subject equaled the sum of the grades. RESULTS: Reader 1 found edema in 16 of 20 runners and four of 12 nonrunners (P < .04); runners had a mean score of 4.7 and nonrunners had a mean score of 0.9 (P < .006). The average number of bones with edema was 3.4 for runners and 0.7 for nonrunners (P < .005). Reader 2 found edema in 16 of 20 runners and two of 12 nonrunners (P < .002); runners had a mean score of 4.5 and nonrunners had a mean score of 0.3 (P < .001). The average number of bones with edema was 3.6 for runners and 0.3 for nonrunners (P < .001). CONCLUSION: When the fast short inversion time inversion-recovery sequence is performed, edema seen within the marrow of runners on MR images may be due to exercise alone. 相似文献
863.
DW Morrish J Dakour H Li J Xiao R Miller R Sherburne RC Berdan LJ Guilbert 《Canadian Metallurgical Quarterly》1997,18(7):577-585
Normal human term cytotrophoblast cells prepared by trypsin-DNAse I digestion with and without secondary immunological purification with CD9 antibodies were investigated for the expression of morphological and genetic markers of proliferation and differentiation. After 24 h of culture, the cell preparations demonstrated spontaneous formation of microvilli and formation of small syncytial units as assessed by desmoplakin staining and FITC-dextran microinjection. EGF was required for mature syncytial formation. Compared to log-phase proliferating HeLa cells, uptake of [3H]thymidine incorporation was low and quickly decreased to negligible levels. Expression of the proto-oncogenes c-myc, c-fos, and c-jun and histone 2A decreased rapidly in the first 24 h of culture in both cell preparations, followed by an increase in expression of c-fos and junB over the next 3 days of culture. Proto-oncogene changes were similar in attached and suspension cells. Spontaneous increases in alpha hCG, pregnancy-specific beta(1)-glycoprotein and 3 beta-hydroxysteroid dehydrogenase (3 beta OHSD) occurred within 1 day in both cell preparations. EGF receptor blocking antibodies did not inhibit minor degrees of spontaneous syncytial formation nor inhibit spontaneous expression of alpha hCG or 3 beta OHSD mRNA, but did prevent extensive synctialization induced by EGF. The results demonstrate that term cytotrophoblast cells even in serum-free conditions or suspension culture rapidly commit to a non-proliferative differentiation program in culture which includes limited syncytialization and marked hormone mRNA expression. However, EGF is required for extensive syncytial development. 相似文献
864.
Our knowledge of the pathophysiology of allergy continues to grow, and with that understanding better treatment methods are being developed. An understanding of the appropriate diagnosis and treatment of allergy is mandatory for the physician who is treating patients with nasal and sinus disorders. Provision for this aspect of patient care will materially benefit such patients, although ignoring it places the physician at risk for repeated treatment failures. 相似文献
865.
Given favorable environmental and demographic conditions, premeiotic clusters of identical mutations can produce a broad distribution of the initial frequency of underdominant alleles. Because of these clusters, new underdominant mutations may not necessarily be as rare in a population as previously assumed. The fixation of underdominant mutations, especially those with low heterozygous fitness, is increased when mutations appear in a cluster due to a genetic change that occurred before germline differentiation. Most restrictions on the fixation of underdominant mutations in a single population, such as strong genetic drift, weak selection against mutant heterozygotes, isolated population structure, inbreeding, meiotic drive, and selection in favor of mutant homozygotes can be relaxed or even dropped. Instead, the fate of strong underdominant mutations is determined mainly by ecological and genetic factors that affect the cluster size distribution of new premeiotic mutations. Accumulation of reproductive isolation by the fixation of underdominant mutations becomes more feasible with clusters, and mutation is not always the weakest force during this evolutionary process. The large mean and variance of reproductive success in many multicellular species make it possible that even underdominant mutations with very low heterozygous fitness could contribute substantially to reproductive isolation. 相似文献
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