Chronic kidney disease (CKD) in the elderly – a geriatrician's perspective

Chronic kidney disease (CKD) is becoming increasingly prevalent among many different populations all over the world, including the US and Europe. Its multitude of complications with devastating outcomes leads to a significantly higher risk for cardio-vascular and all-cause mortality in an individual. However, it is clear now that early detection of CKD might not only delay some of the complications but also prevent them. Therefore, various important public health organizations all over the world have turned their focus and attention to CKD and its risk factors, early detection and early intervention. Nevertheless, the general goals in preventing the increase in CKD and its complications are far from being completely achieved. Why is this so? What is the magnitude and complexity of the problem? How is it affecting the population – are there differences in its affection by age, gender or frail elderly versus the robust? Are we modifying the risk factors appropriately and aggressively? Are there subtle differences in managing the risk factors in those on dialysis versus the non-dialysis CKD patients? Is it important to treat anaemia of CKD aggressively, will it make a difference in the disease progression, its complications or to quality of life? What do these unfortunate individuals commonly succumb to? What do we advise patients who refuse dialysis or those who desire dialysis or transplant? Are there useful non-dialytic treatment recommendations for those who refuse dialysis? What is the role of the physicians caring for the elderly with CKD? When should the primary care givers refer a CKD patient to a nephrologist? The key to eventually controlling incident and prevalent CKD and improve quality of life of affected individuals, lies in not only knowing these and many other vital aspects, but also in applying such knowledge compulsively in day-to-day practice by each and every one us. As CKD is increasingly a disease of the elderly with men being affected more, this review details fairly comprehensively the vital aspects of CKD, especially from a primary care geriatrician's practical standpoint.     

Curvelet 域蒙特卡罗估计的随机噪声衰减

针对低信噪比地震资料进行噪声压制时, 传统滤波方法容易损伤有效波。研究认为, curvelet 多尺度多方向的分析能力可以有效分离随机噪声, 提出基于蒙特卡罗估计的自适应非线性阈值函数法衰减噪声能量, 实现在压制噪声的同时保持有效反射信息。模型算例及大巴山地区某地震资料的处理实例表明, 该方法能够有效地压制随机干扰, 同相轴连续性与剖面信噪比较传统小波方法显著提高, 一定程度上改善了常规滤波处理方法在压制噪声的同时对有效波的影响。     

The association between physical fitness and physical activity among Chinese college students

Abstract

Objective: The constant deterioration of the physical fitness of college students has been a popular topic in China, thus this research analyzes the potential health risk of inadequate physical activity among college students. Participants/methods: During the national student fitness test (NSFT) in 2012, 1500 students from Tsinghua University were recruited and asked to complete the international physical activity questionnaire. Finally, 1414 (94.3%) students completed the study. Results/conclusions: Compared with those students who actively participate in exercise, the risk of obesity in college students lacking exercise was 1.25 times higher. Likewise, the probability of failure in the grip strength test and the standing long jump was also higher, with increases of 2.39 fold and 1.39 fold, respectively. Moreover, the total score of physical fitness test was the same. Consequently, this study suggests that college students should exercise regularly to increase their physical fitness.     

泡沫经济崩溃后的日本中流意识

近年来对经济高速增长时期的日本中流意识的研究可谓汗牛充栋。随着经济形势的变化,日本泡沫经济崩溃之后的中流意识发生了很大变化,有的学者甚至提出了“中流意识消失”说;有的学者认为日本两极分化严重,社会被分成了“胜利组”和“失败组”;还有学者认为日本已经沦为“下流社会”。在以上诸观点的基础上,从历史与现状的角度对泡沫经济崩溃之后日本的中流意识进行了探讨。     

Branching Random Walks With Several Sources*

A continuous-time branching random walk on multidimensional lattices with a finite number of branching sources of three types leads to explicit conditions for the exponential growth of the total number of particles. These conditions are expressed in terms of the spectral characteristics of the operator describing the mean number of particles both at an arbitrary point and on the entire lattice.     

The impact of respondents and interviewers on interview speed in face-to-face interviews

In surveys carried out by interviewers trained according to the key principle of standardized interviewing it is assumed that the interviewer has only limited impact on the time a respondent needs to answer questions. In the paper the effects of interviewers and respondent characteristics on interview speed are analyzed simultaneously by means of a three-level random coefficient model. Data from the fifth round of the European Social Survey (ESS) are used. In twelve participating countries (CAPI) timers were implemented at several places in the questionnaire. Based on this time information the interview speed (number of questions asked per minute) was measured for each respondent during five modules of the questionnaire. The results support most of the expectations concerning the effects of the respondent characteristics. However, the results also indicate that, for all countries, interviewers strongly determine the interview speed and that interview length is not a simple linear function of the number of questions in a questionnaire.     

Conditional mode estimation for functional stationary ergodic data with responses missing at random

In this paper, we investigate the asymptotic properties of a non-parametric conditional mode estimation given a functional explanatory variable, when functional stationary ergodic data and missing at random responses are observed. First of all, we establish asymptotic properties for a conditional density estimator from which we derive almost sure convergence (with rate) and asymptotic normality of a conditional mode estimator. This new estimate take into account missing data, and a simulation study is performed to illustrate how this fact allows to get higher predictive performances than those obtained with standard estimates.     

On Nonsmooth Estimating Functions via Jackknife Empirical Likelihood

In many applications, the parameters of interest are estimated by solving non‐smooth estimating functions with U‐statistic structure. Because the asymptotic covariances matrix of the estimator generally involves the underlying density function, resampling methods are often used to bypass the difficulty of non‐parametric density estimation. Despite its simplicity, the resultant‐covariance matrix estimator depends on the nature of resampling, and the method can be time‐consuming when the number of replications is large. Furthermore, the inferences are based on the normal approximation that may not be accurate for practical sample sizes. In this paper, we propose a jackknife empirical likelihood‐based inferential procedure for non‐smooth estimating functions. Standard chi‐square distributions are used to calculate the p‐value and to construct confidence intervals. Extensive simulation studies and two real examples are provided to illustrate its practical utilities.