Conditional inference in finite population sampling under a calibration model

Several estimators, including the classical and the regression estimators of finite population mean, are compared, both theoretically and empirically, under a calibration model, where the dependent variable(y), and not the independent variable(x), can be observed for all units of the finite population. It is shown asymptotically that when conditioned on x, the bias of the classical estimator may be much smaller than that of the regression estimators; whereas when conditioned on y, the regression estimator may have much smaller conditional bias than the classical estimator. Since all the y's(not x's) can be observed, it seems appropriate to make comparison under the conditional distribution of each estimator with y fixed. In this case, the regression estimator has smaller variance, smaller conditional bias, and the conditional coverage probability closer to its nominal level     

Maximum likelihood estimation of correlation between maximal oxygen consumption and the 6-min walk test in patients with chronic heart failure

Maximal oxygen consumption (VO₂max) is the standard measurement used to quantify cardiovascular functional capacity and aerobic fitness. Unfortunately, it is a costly, impractical and labour-intensive measure to obtain. The 6-min walk test (6MWT) also assesses cardiopulmonary function, but in contrast to the VO₂max test, it is inexpensive and can be performed almost anywhere. Various medical studies have addressed the correlation between VO₂max and 6MWT in patients with chronic heart failure. Of particular interest, from a medical point of view, is the conditional correlation between the two measures given the individual's height, weight, age and gender. In this paper, we have calculated the maximum likelihood estimate of the conditional correlation in patients with chronic heart failure under the assumption of skew normality. Data were recorded from 98 patients in the Operative Unit of Thoracic Surgery in Bari, Italy. The estimated conditional correlation was found to be much smaller than estimated marginal correlations reported in the medical literature.     

耐力运动对大鼠血液学指标影响的实验研究

通过测定大鼠4周耐力运动后RBC、Hb、MCT、MCV的变化，并观察大鼠一般表现，结果：4周耐力运动后大鼠RBC显减少（P＜0．05），Hb下降（P＜0．05），表明本实验采用的运动形式和运动负荷量能造成大鼠运动性贫血，可作为研究运动性贫血的动物模型。     

中华女子学院跆拳道训练课的质性研究

以质性研究的范式为基础,采用深入访谈法,结合内因、外因分析探讨中华女子学院15位女子跆拳道队员坚持训练两年后,身体、心理及意志均得到提升,进而得出结论：通过跆拳道训练课的训练及比赛,队员们不仅在体质、技术方面有了较大提高,更可贵的是培养磨炼了顽强无畏的意志,耐受挫能力亦同样得到较大提高,并潜移默化到生活学习中.     

A Bayesian ordinal logistic regression model to correct for interobserver measurement error in a geographical oral health study

Summary.  We present an approach for correcting for interobserver measurement error in an ordinal logistic regression model taking into account also the variability of the estimated correction terms. The different scoring behaviour of the 16 examiners complicated the identification of a geographical trend in a recent study on caries experience in Flemish children (Belgium) who were 7 years old. Since the measurement error is on the response the factor 'examiner' could be included in the regression model to correct for its confounding effect. However, controlling for examiner largely removed the geographical east–west trend. Instead, we suggest a (Bayesian) ordinal logistic model which corrects for the scoring error (compared with a gold standard) using a calibration data set. The marginal posterior distribution of the regression parameters of interest is obtained by integrating out the correction terms pertaining to the calibration data set. This is done by processing two Markov chains sequentially, whereby one Markov chain samples the correction terms. The sampled correction term is imputed in the Markov chain pertaining to the regression parameters. The model was fitted to the oral health data of the Signal–Tandmobiel^® study. A WinBUGS program was written to perform the analysis.     

中师学生体育炼身运动负荷标准探讨

运用现代科学体育方法学的基本原理———炼身运动负荷价值阈 ,在中师体育教育实践中进行实验研究 ,以求全面提高中师体育教育教学质量     

大学生余暇体育促进终身健康发展的研究

余暇体育在广泛意义上讲指学生在参与体育锻炼时的主要方法和手段。本文应用科学的研究方法分析影响当代大学生参与余暇体育的主、客观因素及参与情况,研究余暇体育对当代大学生终身健康发展的重要作用;并提出结论与建议。     

对改革多媒体教学软件设计课程教学的探讨

本文通过分析多媒体教学软件设计课程在传统教学模式下存在的弊端,从教学规律出发,深入探讨该课程的教学特点,提出教学改革的新思路,研究认为多媒体教学软件设计课程必须改革。     

体育锻炼对职业中专学生人际交往困扰的影响

采用问卷调查法对职业中专学生的体育锻炼和人际交往困扰及其关系进行研究。结果表明,职业中专尚有很大一部分学生在人际总分及其各维度上存在一定困扰或是严重困扰,女生在待人接物和异性交往方面好于男生,高年级学生在待人接物、异性交往和人际总分上好于低年级学生;大锻炼量学生的人际交往困扰少于中小锻炼量学生,而起主要作用的是每次参与锻炼的时间。     

Association of age and physical exercise with bodyweight and body composition in Asian Chinese men

Background.?The present study sought to examine the association between physical exercise as a lifestyle habit with anthropometric parameters and body composition and aging in men.

Methods.?Intensity of exercise was scored as metabolic equivalent-min/week (MET-min/week) from data of the questionnaire, while anthropometric parameters and body composition were carried out by standard measuring instruments and dual-energy X-ray absorptiometry scanner, respectively.

Results.?Age was associated with decreases in bodyweight, height, total lean mass and bone mass, but an increase in fat mass. The negative association of lean mass with age was predominantly due to the negative association of lean masses in the legs and arm, while the positive association of fat mass with age was primarily due to the positive association of fat masses in the trunk and abdomen. Exercise of intensity greater than 1000 MET-min/week was significantly associated with higher lean and bone masses and lower fat mass. The increase in lean mass was predominantly in the legs, while the decreases in fat mass were in the trunk and abdomen.

Conclusion.?The study showed that the high intensity of physical exercise, equivalent to greater than 1000 MET-min/week, is required to effect beneficial changes in the body composition. Hence, results from the study support the importance of promoting a lifestyle habit of exercise of sufficient intensity in order to mitigate the increase risks of sarcopenia and obesity and their attendant ill effects on health in men as they age.