An on-line phase measurement system for quality assurance of the BSD 2000. Part I: technical description of the measurement system

The hyperthermia system BSD 2000 with the ring applicator Sigma 60 utilizes the principle of a phase controlled group radiation source. The accuracy of the phase relationship between the four receiving HF signals is crucial for the position of the electric field inside the applicator. Therefore, essential significance falls to the phase control of the system. An automatic phase measuring technique has been developed to register immediately the phase position of the four channels of the BSD 2000 with respect to a reference signal. The system improves the ensurance of the technical safeguarding. In the first part of this work, the technical realization of the measurement system is described and first measurements with the system are given. In the second part, results with respect to the quality assurance of the BSD 2000 system are presented.     

Psychometric properties of the Arabic self-report version of the strengths and difficulties questionnaire

Students in middle school tend to display emotional and behavioural difficulties (EBDs) compared to other forms of psychopathology. Early identification of EBDs is therefore a priority in order to prevent the chronic co-morbidity with other forms of psychopathology which may affect students’ academic achievement. Assessment of EBDs has been traditionally undertaken via proxy reporting; but psychometrically rigorous instruments are needed so that children and adolescents can report on their own emotions and behaviours. Such need increases in the Omani context given the lack of EBDs adequate assessment instruments. In the current study the factor structure of the Arabic self-report version of the Strengths and Difficulties Questionnaire (A-SDQ) was examined in a sample of 815 middle school students (mean age = 14 years). The study tested the SDQ original five-factor model which received considerable empirical support. Responses on the A-SDQ were compared to responses obtained via proxy reports from teachers and parents through confirmatory factor analyses (CFAs). Results showed a reasonable fit for the three informant forms. Nevertheless, there were differences in item loadings across the three informant forms. Additionally, participants’ self-report responses were tested for invariance across gender. CFAs provided support to the invariance hypothesis for item loadings, indicating that the items were similarly valid indices of the five factors for males and females. Factor correlations, factor variances and item residuals were not invariant across gender.What this paper addsThis paper, to our knowledge, is the first research paper that provides empirical evidence on the Arabic self report version of the Strengths and Difficulties Questionnaire (A-SDQ) within a school-based sample. Though the focus was on the self-report version we collected data from the proxy versions for parents and teachers to provide additional evidence on the construct validity of the (A-SDQ) through cross informant data.     

Identification and estimation of single‐index models with measurement error and endogeneity

Economic variables are often measured with an error and may be endogenous. In this paper, we give new identification results for the ratio of partial effects in linear index models with measurement error and endogeneity. The identification restrictions include independence of covariates and error terms, and the derivative of some conditional mean functions being nonzero. We propose a local polynomial regression estimator to estimate the single‐index parameters. We apply these tools to estimate the labour‐supply elasticity and find that the labour‐supply elasticity for married men is positive, while the coefficients for married women are negative for the full sample and positive for the working sample.     

An Evaluation of the Protective Effects of Thymoquinone on Amikacin-Induced Ototoxicity in Rats

Objectives

In this study we investigated the probable protective effects of thymoquinone on amikacin-induced ototoxicity in rats.

Methods

Thirty-two healthy rats were divided into four groups (amikacin, amikacin+thymoquinone, thymoquinone, and no treatment). Thymoquinone was fed to the rats via oral gavage in a dose of 40 mg/kg/day throughout the study period of 14 days. Amikacin was given by the intramuscular route in a dose of 600 mg/kg/day. Audiological assessment was conducted by the distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) tests, administered to all rats at the beginning of the study, and also on days 7 and 15. Biochemical parameters were calculated at the termination of the study to evaluate the oxidative status.

Results

There were significant decreases in DPOAE values and significant increases in ABR thresholds of the amikacin group on days 7 and 15, as compared to the amikacin+thymoquinone group. While ABR thresholds of the amikacin group increased significantly on days 7 and 15 as compared to their initial values, there were no significant differences between the initial and the 7th and 15th day values of ABR thresholds in the amikacin+thymoquinone group. Total oxidant status and oxidative stress index values of the amikacin+thymoquinone group were significantly lower than those of the amikacin group. Total antioxidant status values of the amikacin+thymoquinone group were significantly higher than those of the amikacin group.

Conclusion

Our study has demonstrated that the ototoxic effect brought forth by amikacin could be overcome with the concurrent use of thymoquinone.     

Benefits of the Restorative Exercise and Strength Training for Operational Resilience and Excellence Yoga Program for Chronic Low Back Pain in Service Members: A Pilot Randomized Controlled Trial

Objective

To examine the feasibility and preliminary effectiveness of an individualized yoga program.

三甲医院中文论文影响力测量模型的构建

利用结构方程模型构建医院中文论文影响力测量模型,分析论文总被引、论文基金资助情况、核心期刊发文数量、中华医学会核心期刊论文数、国际合著论文数等指标对论文影响力的贡献程度,发现上述5个指标均能很好地测量三甲医院中文科技论文影响力。     

药品价格指数的方法学综述

目的:综述药品价格指数的研究方法,为药品价格指数实证研究提供方法学借鉴。方法:以近年来的国内外研究文献为基础,从指数方法(公式)、药品产品的定义、价格和数量计量单位三个方面进行综述,并对选择不同方法的优缺点以及测量偏倚进行评析。结果:价格指数的结果会随着指数公式所选择的权重、产品的定义以及价格和数量计量单位的不同而不同。在指数公式的选择中是否考虑了新产品上市和老产品退市的产品更新换代问题以及产品的质量变化问题等同样会使得指数结果具有较大差异。结论:药品价格指数的研究方法还有待进一步研究完善,学术界应致力于对价格指数进行更深入的研究,以达到更精确的测量。在实证分析中尽可能采用多种方法进行计算,以更加准确地反映药品价格水平的变化。     

Confirmatory factor analysis and measurement invariance by gender,age and levels of psychological distress of the short TEMPS-A

Background

The Temperament Evaluation of Memphis, Pisa, Paris and San Diego – Autoquestionnaire (TEMPS-A) is a widely used self-reported tool aimed at measuring the affective temperaments that define the bipolar spectrum, with cyclothymic, depressive, irritable, hyperthymic, and anxious subscales. Confirmatory factor analysis (CFA) was rarely used to confirm the expected five-factor model. Measurement invariance was never tested.

Methods

Cross-sectional, survey design involving 649 Italian college students (males: 47%). The short 39-item TEMPS-A and the 12-item General Health Questionnaire (GHQ-12) were used as measures of the affective temperaments and of psychological distress, respectively. CFA was applied to the TEMPS-A. Measurement invariance by gender, age and levels of psychological distress on the GHQ-12 was calculated with the establishment of subsequent equivalence constraints in the model parameters across groups.

Results

The expected five-factor model had the best fit for all CFA indexes. Configural, metric and scalar invariance of the five-factor model of the TEMPS-A was proved across gender, age and levels of psychological distress of the participants. The hyperthymic temperament subscale has low or no links with the other affective temperament subscales, which were interrelated with medium to large effect sizes.

Limitations

College students might be not representative of the general population. No information on the clinical status of the students was available beyond self-report data.

Conclusion

The study proved the measurement invariance of the (short) TEMPS-A, which is a pre-requisite to compare groups or individuals in cross-sectional and longitudinal surveys. Generalizability cannot be assumed without replication of the findings in clinical samples.