Alzheimer's disease

In this case study, we describe the symptoms, neuropsychological testing, and brain pathology of a man with Alzheimer's disease (AD). AD commonly presents with impairment of memory and language function. In this case, language difficulties were noted more prominently than was memory impairment. Throughout the limbic system and neocortex of the patient were large numbers of senile plaques and neurofibrillary tangles, the pathological hallmarks of AD.     

Frontotemporal dementia

In this case study, we describe the symptoms, neuropsychological testing, and brain pathology of a man with frontotemporal dementia (FTD). FTD most often presents with either a change in personality or behavior, such as social withdrawal, increased gregariousness, disinhibition, or obsessive behaviors; or with impairment of language function. Memory difficulties are common, but usually are less prominent than these other symptoms in the early stages of the disease. Frequently, psychiatric diagnoses are initially the primary consideration. Cases may be either familial or sporadic. In this familial case, an autopsy was ultimately performed and revealed findings characteristic of FTD, with grossly evident focal brain degeneration in the frontal and temporal regions, microscopic signs of gliosis, and cellular abnormalities of the intracellular microtubule-associated protein tau.     

Improved Measures of the Spread of Data for Some Unknown Complex Distributions Using Saddlepoint Approximations

Measures of the spread of data for random sums arise frequently in many problems and have a wide range of applications in real life, such as in the insurance field (e.g., the total claim size in a portfolio). The exact distribution of random sums is extremely difficult to determine, and normal approximation usually performs very badly for this complex distributions. A better method of approximating a random-sum distribution involves the use of saddlepoint approximations.

Saddlepoint approximations are powerful tools for providing accurate expressions for distribution functions that are not known in closed form. This method not only yields an accurate approximation near the center of the distribution but also controls the relative error in the far tail of the distribution.

In this article, we discuss approximations to the unknown complex random-sum Poisson–Erlang random variable, which has a continuous distribution, and the random-sum Poisson-negative binomial random variable, which has a discrete distribution. We show that the saddlepoint approximation method is not only quick, dependable, stable, and accurate enough for general statistical inference but is also applicable without deep knowledge of probability theory. Numerical examples of application of the saddlepoint approximation method to continuous and discrete random-sum Poisson distributions are presented.     

The Effects of Group Attitudes Toward Alternative GDSS Designs on the Decision-making Performance of Computer-Supported Groups*

Empirical investigations of the effects of group decision support systems (GDSS) accord relatively little attention to the role of attitudes developed by groups toward the GDSS. This study draws upon the theory of social influence to examine the role played by group attitudes in mediating the impact of GDSS designs on group decision-making performance. We found that, in addition to capabilities of GDSS designs, group attitudes toward GDSS were influential in affecting group decision-making performance. The managerial implications of the study are: (1) effective GDSS designs for supporting groups in equivocal decision-making contexts should include structures for communication and consensus support and (2) attempts should be made to enhance user attitudes toward the GDSS through design features of the GDSS, training, and facilitation of positive social influences within the group. The study also provides encouraging evidence about the value of social theories, such as the social influence model and the adaptive structuration theory, in investigating GDSS effects. Further, this study illustrates the value of the partial least squares (PLS) analysis method for testing holistic structural models of GDSS effects.     

Physical capital taxation and labor income taxation in an endogenous growth model with new generations

This paper examines the growth and welfare effects of physical capital taxation and labor income taxation. It is found that the impact of a rise in the physical capital tax rate on the balanced growth rate is crucially related to the birth rate, but a rise in the labor income tax rate definitely reduces the balanced growth rate regardless of the birth rate. It is also found that an increase in the physical capital income tax rate will harm the older but will benefit the younger, while an increase in the labor income tax rate will benefit the older but will harm the younger.

Parameter Estimation for Bivariate Shock Models with Singular Distribution for Censored Data with Concomitant Order Statistics

When two‐component parallel systems are tested, the data consist of Type‐II censored data X_(i), i= 1, n, from one component, and their concomitants Y _[i] randomly censored at X_(r), the stopping time of the experiment. Marshall & Olkin's (1967) bivariate exponential distribution is used to illustrate statistical inference procedures developed for this data type. Although this data type is motivated practically, the likelihood is complicated, and maximum likelihood estimation is difficult, especially in the case where the parameter space is a non‐open set. An iterative algorithm is proposed for finding maximum likelihood estimates. This article derives several properties of the maximum likelihood estimator (MLE) including existence, uniqueness, strong consistency and asymptotic distribution. It also develops an alternative estimation method with closed‐form expressions based on marginal distributions, and derives its asymptotic properties. Compared with variances of the MLEs in the finite and large sample situations, the alternative estimator performs very well, especially when the correlation between X and Y is small.     

The Politics of Emigration and Expatriation: Ethnicisation of Citizenship in Imperial Germany and China

In the era of perpetual allegiance, the nationality regimes of Germany and China were characterised by restricted, instead of voluntary, expatriation. Although this policy reflected the two states' perceptions of overseas Germans and Chinese as sources of national strength, it also resulted in widespread dual nationality practices. Using case studies of Germany and China, this article analyses the right to expatriation in the aforementioned era. This study suggests that both the imperial regimes adopted strict expatriation rules with knowledge of the possibility of dual allegiance but remained indifferent to its consequences. Dual nationality practices were the accidental result of strict expatriation rather than a deliberate outcome.     

Cheong: The Socioemotional Grammar of Koreans

Based on the replies of 36 Korean university students, we analyzed the structural properties that underpin the culture-bound concept of Cheong. Cheong embodies the emotional links among individuals connected to each other by feelings of we-ness and exhibiting the humanistic side of their selves. It is concluded that Western models of the nature of persons and of social relationships are insufficient to account for the socioemotional characteristics of Koreans.     

风险投资项目退出时机选择的定量分析模型与应用研究

在研究风险投资项目退出时机选择的一般性原则时,通过引入持有期成本率γ0和目标收益率TR0两个参数,运用内部收益率(IRR)和净现值(NPV)指标,建立起一个动态的风险投资项目退出时机选择定量分析模型,为风险投资项目退出时机选择提供可操作的定量化分析工具。     

基于环境因素的中国省级能源效率评价

能源环境问题是一经济体能源效率高低的尺度,运用基于定向技术距离函数的投入产出导向型DEA方法,在模型中加入污染排放指标并设定非意愿投入变量,测度了中国29个地区1999-2008年的全要素能源技术效率并作相应对比分析。结果显示:全要素能源技术效率低于全要素技术效率,考虑环境因素的全要素能源技术效率高于不考虑环境因素的;考虑环境因素的中国东部地区能源效率普遍高于中、西部地区,节能减排的重点应该放在全要素能源效率比较低的中、西部省份。