Sexuality in Older Adults (65+)—An Overview of the Literature,Part 1: Sexual Function and its Difficulties

Objectives: The aim of the current article was to provide an overview of literature on sexual function and sexual difficulties in older adults. Method: The authors conducted a narrative review of papers published in English between January 2005 and July 2015 based on an extensive search in PsycINFO. Results: The review showed that although common biological changes may adversely affect sexual function in old age, sexual experience seems to also be affected by psychological and interpersonal factors. Conclusions: Greater life expectancy and better medical care will result in older individuals with chronic diseases living longer. The need for help to cope with changes in sexual health is likely to increase in older adults, as sexuality may be negatively affected through several pathways.     

On robustness of the Shiryaev–Roberts change-point detection procedure under parameter misspecification in the post-change distribution

The gist of the quickest change-point detection problem is to detect the presence of a change in the statistical behavior of a series of sequentially made observations, and do so in an optimal detection-speed-versus-“false-positive”-risk manner. When optimality is understood either in the generalized Bayesian sense or as defined in Shiryaev's multi-cyclic setup, the so-called Shiryaev–Roberts (SR) detection procedure is known to be the “best one can do”, provided, however, that the observations’ pre- and post-change distributions are both fully specified. We consider a more realistic setup, viz. one where the post-change distribution is assumed known only up to a parameter, so that the latter may be misspecified. The question of interest is the sensitivity (or robustness) of the otherwise “best” SR procedure with respect to a possible misspecification of the post-change distribution parameter. To answer this question, we provide a case study where, in a specific Gaussian scenario, we allow the SR procedure to be “out of tune” in the way of the post-change distribution parameter, and numerically assess the effect of the “mistuning” on Shiryaev's (multi-cyclic) Stationary Average Detection Delay delivered by the SR procedure. The comprehensive quantitative robustness characterization of the SR procedure obtained in the study can be used to develop the respective theory as well as to provide a rational for practical design of the SR procedure. The overall qualitative conclusion of the study is an expected one: the SR procedure is less (more) robust for less (more) contrast changes and for lower (higher) levels of the false alarm risk.     

Back propagation neural networks and multiple regressions in the case of heteroskedasticity

This paper compares the performance between regression analysis and a clustering based neural network approach when the data deviates from the homoscedasticity assumption of regression. Heteroskedasticity is a problem that arises in linear regression due to the unequal error variances. One of the methods to deal heteroskedasticity in classical regression theory is weighted least-square regression (WLS). In order to deal the problem of heteroskedasticity, backpropagation neural network is applied. In this context, an algorithm is proposed which is based on robust estimates of location and dispersion matrix that helps in preserving the error assumption of the linear regression. Analysis is carried out with appropriate designs using simulated data and the results are presented.     

Asymptotic expansions of density of normalized extremes from logarithmic general error distribution

Logarithmic general error distribution is an extension of the log-normal distribution. In this paper, the asymptotic expansions of densities of normalized maximum from logarithmic general error distribution are derived under two different kinds of normalized constants. By applying the main results, the higher-order expansions of moments of maxima are established.     

Parameter estimation for multivariate diffusion processes with the time inhomogeneously positive semidefinite diffusion matrix

Statistical inference for the diffusion coefficients of multivariate diffusion processes has been well established in recent years; however, it is not the case for the drift coefficients. Furthermore, most existing estimation methods for the drift coefficients are proposed under the assumption that the diffusion matrix is positive definite and time homogeneous. In this article, we put forward two estimation approaches for estimating the drift coefficients of the multivariate diffusion models with the time inhomogeneously positive semidefinite diffusion matrix. They are maximum likelihood estimation methods based on both the martingale representation theorem and conditional characteristic functions and the generalized method of moments based on conditional characteristic functions, respectively. Consistency and asymptotic normality of the generalized method of moments estimation are also proved in this article. Simulation results demonstrate that these methods work well.     

The performance of model averaged tail area confidence intervals

We investigate the exact coverage and expected length properties of the model averaged tail area (MATA) confidence interval proposed by Turek and Fletcher, CSDA, 2012, in the context of two nested, normal linear regression models. The simpler model is obtained by applying a single linear constraint on the regression parameter vector of the full model. For given length of response vector and nominal coverage of the MATA confidence interval, we consider all possible models of this type and all possible true parameter values, together with a wide class of design matrices and parameters of interest. Our results show that, while not ideal, MATA confidence intervals perform surprisingly well in our regression scenario, provided that we use the minimum weight within the class of weights that we consider on the simpler model.     

教育扩张对大学毕业生收入的影响——基于断点回归设计分析

本文使用2012年"中国劳动力动态调查"数据②,基于断点回归方法评估高等教育扩招政策对收入的影响.本文的实证研究主要发现扩招政策对不同收入群体的影响不同,对低收入群体并无显著影响,但显著提高了高收入群体的收入,说明扩招促使高收入群体的高等教育收益高于低收入群体,这表明在一定程度上高等教育扩招政策并不利于社会公平,可能会造成居民收入差距进一步扩大.     

Giving Victims of Bullying a Voice: A Qualitative Study of Post Bullying Reactions and Coping Strategies

Current research on how adolescents cope with bullying is primarily quantitative, examines youth in Grades 1 through 6, and neglects to specifically assess how victims of bullying cope with being bullied. The current qualitative study explored the coping strategies of 22 rural middle- and high-school youth victimized by bullying. Results indicated that youth report using an array of emotion focused coping strategies (an internal coping strategy that focuses on emotion regulation) and problem focused coping strategies (active behaviors that are aimed to decrease or eradicate the stressor). These coping strategies included help seeking, physical and verbal aggression, standing up for themselves, and prosocial bystander behavior. While the majority of coping strategies were similar between middle- and high-school participants, these groups reported utilizing verbal and physical aggression in different ways. Further, certain coping strategies, such as help seeking and lashing out with physical and verbal aggression, were utilized as both emotion- and problem-focused coping strategies. Implications are discussed.     

西藏地区企业现代化与居民现代化相互影响的路径研究

企业现代化与居民现代化均是西藏地区现代化建设所追求的重要目标.本文从西藏地区的实际情况出发,从宏观层面探索了二者的相互联系的内在机理,认为二者通过能量、信息以及物质的交换,将会形成一个微观的现代化社会系统.正是由于这个系统的存在,从而使二者必然存在相互影响,且存在一定的影响路径.     

中国农产品市场开放与贸易政策——技术性贸易壁垒的视角

中国加入世界贸易组织以后,严守承诺开放农产品市场,但农产品出口正在成为中美贸易摩擦的主要根源。选取棉花、小麦、稻米和大豆等四种主要农产品,通过测算技术性贸易壁垒,考察净出口波动、产出效率和补贴政策,对中美农产品市场开放程度和贸易政策展开比较分析后发现:美国凭借其生产技术和贸易制度设计上的优势地位,实施严格的技术规制来保护本国农产品市场,向生产者提供巨额补贴以巩固市场竞争力。由于生产技术落后和贸易规则制定话语权的缺失,中国农产品市场开放有背离本国农业发展水平的趋势,产业安全正遭受巨大冲击。中国正在成为新多边贸易体制的重要力量,为打破农产品贸易被动局面,中国应将发展中国家利益纳入贸易制度设计中去,增大补贴范围和补贴力度,提高农业生产技术水平,加强对贸易壁垒的防御能力。