Gender differences in self-esteem: A meta-analysis.

Two analyses were conducted to examine gender differences in global self-esteem. In Analysis I, a computerized literature search yielded 216 effect sizes, representing the testing of 97,121 respondents. The overall effect size was 0.21, a small difference favoring males. A significant quadratic effect of age indicated that the largest effect emerged in late adolescence (d?=?0.33). In Analysis II, gender differences were examined using 3 large, nationally representative data sets from the National Center for Education Statistics (NCES). All of the NCES effect sizes, which collectively summarize the responses of approximately 48,000 young Americans, indicated higher male self-esteem (ds ranged from 0.04 to 0.24). Taken together, the 2 analyses provide evidence that males score higher on standard measures of global self-esteem than females, but the difference is small. Potential reasons for the small yet consistent effect size are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical and genetic characterization of a gentisate 1, 2-dioxygenase from Sphingomonas sp. strain RW5

A 4,103-bp long DNA fragment containing the structural gene of a gentisate 1,2-dioxygenase (EC 1.13.11.4), gtdA, from Sphingomonas sp. strain RW5 was cloned and sequenced. The gtdA gene encodes a 350-amino-acid polypeptide with a predicted size of 38.85 kDa. Comparison of the gtdA gene product with protein sequences in databases, including those of intradiol or extradiol ring-cleaving dioxygenases, revealed no significant homology except for a low similarity (27%) to the 1-hydroxy-2-naphthoate dioxygenase (phdI) of the phenanthrene degradation in Nocardioides sp. strain KP7 (T. Iwabuchi and S. Harayama, J. Bacteriol. 179:6488-6494, 1997). This gentisate 1,2-dioxygenase is thus a member of a new class of ring-cleaving dioxygenases. The gene was subcloned and hyperexpressed in E. coli. The resulting product was purified to homogeneity and partially characterized. Under denaturing conditions, the polypeptide exhibited an approximate size of 38.5 kDa and migrated on gel filtration as a species with a molecular mass of 177 kDa. The enzyme thus appears to be a homotetrameric protein. The purified enzyme stoichiometrically converted gentisate to maleylpyruvate, which was identified by gas chromatography-mass spectrometry analysis as its methyl ester. Values of affinity constants (Km) and specificity constants (Kcat/Km) of the enzyme were determined to be 15 microM and 511 s-1 M-1 x 10(4) for gentisate and 754 microM and 20 s-1 M-1 x 10(4) for 3, 6-dichlorogentisate. Three further open reading frames (ORFs) were found downstream of gtdA. The deduced amino acid sequence of ORF 2 showed homology to several isomerases and carboxylases, and those of ORFs 3 and 4 exhibited significant homology to enzymes of the glutathione isomerase superfamily and glutathione reductase superfamily, respectively.     

Theoretical Study of Strengthening for Increased Shear Bearing Capacity

In recent years, the use of carbon fiber reinforced polymer (CFRP) has been shown to be a competitive method for strengthening both the structural and economic performance of concrete. The method has been used for almost a decade, yet – most research undertaken has studied the flexural behavior of strengthened structures, while research on shear strengthening has been limited. The work presented in this paper focuses on CFRP shear strengthening of concrete beams. The theory presented addresses the limitations of the widely used truss model, and a refinement is suggested. A reduction factor to consider the nonuniform strain distribution over the cross section is proposed and strain limitations are prescribed for the principal strain in the concrete instead of the fiber strain, as in previous studies. The derived analytical model is compared to experimental data from tests. Fairly good agreement is found between results from tests and calculated values from theory with regard to both shear-bearing capacity and average fiber utilization.     

Benzodiazepine use and cognitive function among community-dwelling elderly

OBJECTIVE: To evaluate the relation between benzodiazepine use and cognitive function among community-dwelling elderly. METHODS: This prospective cohort study included 2765 self-reporting subjects from the Duke Established Populations for Epidemiologic Studies of the Elderly. The subjects were cognitively intact at baseline (1986-1987) and alive at follow-up data collection 3 years later. Cognitive function was assessed with the Short Portable Mental Status Questionnaire (unimpaired versus impaired and change in score) and on the basis of the number of errors on the individual domains of the Orientation-Memory-Concentration Test. Benzodiazepine use was determined during in-home interviews and classified by dose, half-life, and duration. Covariates included demographic characteristics, health status, and health behaviors. RESULTS: After control for covariates, current users of benzodiazepine made more errors on the memory test (beta coefficient, 0.35; 95% confidence interval [CI], 0.10 to 0.61) than nonusers. Further assessment of the negative effects on memory among current users suggested a dose response in which users taking the recommended or higher dose made more errors (beta coefficient, 0.57; 95% CI, 0.26 to 0.88) and a duration response in which long-term users made more errors (beta coefficient, 0.39; 95% CI, 0.05 to 0.73) than nonusers. Users of agents with long half-lives and users of agents with short half-lives both had increased memory impairment (beta coefficient, 0.32; 95% CI, 0.01 to 0.64 and beta coefficient, 0.38; 95% CI, 0.02 to 0.75, respectively) relative to nonusers. Previous benzodiazepine use was unrelated to memory problems, and current and previous benzodiazepine use was unrelated to level of cognitive functioning as measured with the other 4 tests. CONCLUSIONS: The results suggested that current benzodiazepine use, especially in recommended or higher doses, is associated with worse memory among community-dwelling elderly.     

Is there a threshold between peak oxygen uptake and self-reported physical functioning in older adults?

Purpose: Few studies have examined the relationship between directly measured oxygen uptake (VO2) and self-reported physical function (PF). The purpose of this study was: 1) to examine the relationship between peak V02 and PF and 2) to determine whether a threshold or cut point exist that distinguishes between individuals reporting required assistance in the performance of functional tasks (low PF) and those who report ability to perform tasks independently (high PF). Methods: Participants were 161 community-dwelling adults, ages 65-90, who had a baseline evaluation for a clinical trail that included measurement of peak V02 and PF consisted of a summary score combining scores from the Older Americans Resources and Services Multidimensional Functional Assessment Questionnaire, Nagi Disability Study. Rosow-Breslau Scale, Physical Function Scale of the Medical Outcomes Study, and the Falls Efficacy Scale. Decision tree, cubic spline, and logistic regression analyses explored these relationships with age, gender, education, race, body mass index, depression, and total number of chronic diseases included as important covariates. Results: Among all covariates examined, peak V02 was most strongly associated with (P = 0.004) with PF. There was not threshold effect. Decision tree analyses indicated that 18.3 mL.kg-1.min-1 was the optimal cut point distinguishing between low PF and High PG (P < 0.0001). Between-gender differences in PF (P = 0.002) were no longer significant when peak V02 was included in the PF model (P = 0.17). Conclusions: These data indicate that individuals with a V02 < 18 mL.kg-1min-1 report significant difficulty in the performance of daily tasks and that differences in peak V02 may explain, in part, why women report more impairment in PF.     

Nonlinearity-insensitive standard-fibre transmission based onoptical-phase conjugation in a semiconductor-laser amplifier

Experimental results are presented confirming that optical-phase conjugation in a semiconductor-laser amplifier has the potential to compensate for the interplay of chromatic dispersion and nonlinear self-phase modulation, thereby enabling high-capacity high-power transmission over standard singlemode fibres