Fisher information in randomly sampled sib pairs and extremely discordant sib pairs in genetic analysis for a quantitative trait locus

The conditional mixture likelihood method using the absolute difference of the trait values of a sib pair to estimate genetic parameters underlies commonly used method in linkage analysis. Here, the statistical properties of the model are examined. The marginal model with a pseudo-likelihood function based on a sample of the absolute difference of sib-traits is also studied. Both approaches are compared numerically. When genotyping is much more expensive than screening a quantitative trait, it is known that extremely discordant sib pairs provide more powerful linkage tests than randomly sampled sib pairs. The Fisher information about genetic parameters contained in extremely discordant sib pairs is calculated using the marginal mixture model. Our results supplement current research showing that extremely discordant sib pairs are powerful for the linkage detection by demonstrating they also contain more information about other genetic parameters.     

Bribes,power, and managerial control in corporate voting games

Proxy fights have received comparatively little attention relative to the more popular methods for corporate control transfer: merger and tender offers. This paper presents an analytic model of the proxy contest as a cooperative game with four players: management, passive shareholders, insurgent shareholders and a trust fund. The power of the players and the effectiveness of certain managerial actions is discussed.     

日本青少年蛰居的现状与对策

蛰居是日本较为严重的青少年问题和社会问题之一，是一种丧失社会行为、自我封闭的消极生活状态。目前，日本青少年蛰居的现状十分严峻，已出现了数十万规模的蛰居者。蛰居的表征相似，诱因和程度却千差万剐，且长期化和高龄化趋势日益增强。随着蛰居人数的增多、时间的延长及蛰居者年龄的增长，如何援助蛰居者，帮助其回归学校或社会，成为日本面临的重要课题之一。为此，日本政府、NPO法人等民间团体积极采取针对蛰居者及其家人的援助对策。     

关于高校树立和落实科学发展观的理性思考

本文提出了高校树立和落实科学发展观应进一步更新办学理念,应坚持学生全面发展与学校全面发展的统一,必须重视规模、结构、质量、效益的协调发展,必须正确处理好改革、发展、稳定三者的关系等观点,并进行了分析和阐释。     

EXACT P‐VALUES FOR DISCRETE MODELS OBTAINED BY ESTIMATION AND MAXIMIZATION

In constructing exact tests from discrete data, one must deal with the possible dependence of the P‐value on nuisance parameter(s) ψ as well as the discreteness of the sample space. A classical but heavy‐handed approach is to maximize over ψ. We prove what has previously been understood informally, namely that maximization produces the unique and smallest possible P‐value subject to the ordering induced by the underlying test statistic and test validity. On the other hand, allowing for the worst case will be more attractive when the P‐value is less dependent on ψ. We investigate the extent to which estimating ψ under the null reduces this dependence. An approach somewhere between full maximization and estimation is partial maximization, with appropriate penalty, as introduced by Berger & Boos (1994, P values maximized over a confidence set for the nuisance parameter. J. Amer. Statist. Assoc. 89 , 1012–1016). It is argued that estimation followed by maximization is an attractive, but computationally more demanding, alternative to partial maximization. We illustrate the ideas on a range of low‐dimensional but important examples for which the alternative methods can be investigated completely numerically.     

Supporting collegiate foster youth and alumni: A mixed-method planning approach for higher education

Despite the proliferation, of on-campus academic support programs for foster youth and alumni (e.g., those formerly in foster care), few conceptual frameworks for developing these programs exist. This study employed Group Concept Mapping (GCM) methodology to delineate a conceptual framework, from the perspective of foster youth and alumni (N = 51), for the development of on-campus support initiatives. GCM is an integrated mixed-method research method that uses non-metric multidimensional scaling and hierarchical cluster analyses, to analyze qualitative data (e.g., statement form) collected during brainstorming sessions. This research was guided by two separate queries: (1) How do foster youth/alumni conceptualize support programs to support foster youth/alumni through to degree completion; and, (2) Is there a difference in priority areas of this conceptualization between current college students, and those who have dropped out of college within the last 18 months? Analyses revealed that participants conceptualized on-campus support programs via an eight-cluster solution, including Campus Awareness, Advocacy, Data Tracking, Pre-College Supports, Fostering Family Connections, Academic Financing, Campus Life, and Peer/Mentor Supports clusters. Additionally, analyses revealed significant priority ratings between areas of this conceptualization. In terms of Importance to academic success, current students rated statements in the Academic Financing and Peer/Mentor Supports clusters significantly lower than did non-students. For Feasibility, current students viewed statements in the Data Tracking, Campus Life, and Peer/Mentor Supports clusters as significantly more feasible than non-students. Pragmatic implications derived from these findings include fostering inclusive campus environments for foster youth/alumni and advocacy undertakings by institutions, on behalf of this population.     

论维果茨基概念形成过程的语言发展观

概念形成过程是维果茨基对人类特有的高级心理机能及其反映形式——意识的探索。他通过儿童语言发展的科学实验论证了儿童日常概念的形成过程,提出了日常概念和学校教授的科学概念之间相互作用的关系,并从科学概念与外语言语发展的相似性导论出外语教学的一系列理论问题。     

马克思主义民主政治观及其对当代中国的启示

这里的马克思主义民主政治观主要指马克思恩格斯和列宁的民主政治思想。马克思恩格斯和列宁虽然没有专门的关于民主政治思想的专著,但却有非常丰富的民主政治思想主张,尤其对民主的重要性、民主形态、民主和经济的辩证关系以及如何发展民主方面有着深刻的认识,是新时期我国推进民主政治建设的指南针,对认清当前我国民主政治发展形势、统一思想具有极其重要的指导作用。     

An Equivalence of Conditional and Unconditional Maximum Likelihood Estimators via Infinite Replication of Observations

Motivated by an application with complex survey data, we show that for logistic regression with a simple matched-pairs design, infinitely replicating observations and maximizing the conditional likelihood results in an estimator exactly identical to the unconditional maximum likelihood estimator based on the original sample, which is inconsistent. Therefore, applying conditional likelihood methods to a pseudosample with observations replicated a large number of times can lead to an inconsistent estimator; this casts doubt on one possible approach to conditional logistic regression with complex survey data. We speculate that for more general designs, an asymptotic equivalence holds.     

Concept mapping internal validity: A case of misconceived mapping?

Since the early 1990s, the concept mapping technique developed by William M. K. Trochim has been widely used by evaluators for program development and evaluation and proven to be an invaluable tool for evaluators and program planners. The technique combines qualitative and statistical analysis and is designed to help identify and prioritize the components, dimensions, and particularities of a given reality. The aim of this paper is to propose an alternative way of conducting the statistical analysis to make the technique even more useful and the results easier to interpret. We posit that some methodological choices made at the inception stage of the technique were ill informed, producing maps of participants’ points-of-view that were not optimal representations of their reality. Such a depiction resulted from the statistical analysis process by which multidimensional scaling (MDS) is being applied on the similarity matrix, followed by a hierarchical cluster analysis (HCA) on the Euclidian distances between statements as plotted on the resulting two-dimensional MDS map. As an alternative, we suggest that HCA should be performed first and MDS second, rather than the reverse. To support this proposal, we present three levels of argument: 1) a logical argument backed up by expert opinions on this issue; 2) statistical evidence of the superiority of our proposed approach and 3) the results of a social validation experiment.