Utilizing Bayesian predictive power in clinical trial design

The Bayesian paradigm provides an ideal platform to update uncertainties and carry them over into the future in the presence of data. Bayesian predictive power (BPP) reflects our belief in the eventual success of a clinical trial to meet its goals. In this paper we derive mathematical expressions for the most common types of outcomes, to make the BPP accessible to practitioners, facilitate fast computations in adaptive trial design simulations that use interim futility monitoring, and propose an organized BPP-based phase II-to-phase III design framework.     

Testing the dilation order by using cumulative residual Tsallis entropy

In this paper, we introduce a new test for the dilation order based on cumulative residual Tsallis entropy of order α. The effect of the values of parameter α on the power of the test statistics is numerically investigated. The asymptotic distribution of the test statistic is given. The performance of the test statistic is evaluated using a simulation study. Finally, some numerical examples illustrating the theory are also given.     

A comparison of recent nonparametric methods for testing effects in two-by-two factorial designs

The two-way two-levels crossed factorial design is a commonly used design by practitioners at the exploratory phase of industrial experiments. The F-test in the usual linear model for analysis of variance (ANOVA) is a key instrument to assess the impact of each factor and of their interactions on the response variable. However, if assumptions such as normal distribution and homoscedasticity of errors are violated, the conventional wisdom is to resort to nonparametric tests. Nonparametric methods, rank-based as well as permutation, have been a subject of recent investigations to make them effective in testing the hypotheses of interest and to improve their performance in small sample situations. In this study, we assess the performances of some nonparametric methods and, more importantly, we compare their powers. Specifically, we examine three permutation methods (Constrained Synchronized Permutations, Unconstrained Synchronized Permutations and Wald-Type Permutation Test), a rank-based method (Aligned Rank Transform) and a parametric method (ANOVA-Type Test). In the simulations, we generate datasets with different configurations of distribution of errors, variance, factor's effect and number of replicates. The objective is to elicit practical advice and guides to practitioners regarding the sensitivity of the tests in the various configurations, the conditions under which some tests cannot be used, the tradeoff between power and type I error, and the bias of the power on one main factor analysis due to the presence of effect of the other factor. A dataset from an industrial engineering experiment for thermoformed packaging production is used to illustrate the application of the various methods of analysis, taking into account the power of the test suggested by the objective of the experiment.     

A latent variable model for analyzing mixed longitudinal (k,l)-inflated count and ordinal responses

A random effects model for analyzing mixed longitudinal count and ordinal data is presented where the count response is inflated in two points (k and l) and an (k,l)-Inflated Power series distribution is used as its distribution. A full likelihood-based approach is used to obtain maximum likelihood estimates of parameters of the model. For data with non-ignorable missing values models with probit model for missing mechanism are used.The dependence between longitudinal sequences of responses and inflation parameters are investigated using a random effects approach. Also, to investigate the correlation between mixed ordinal and count responses of each individuals at each time, a shared random effect is used. In order to assess the performance of the model, a simulation study is performed for a case that the count response has (k,l)-Inflated Binomial distribution. Performance comparisons of count-ordinal random effect model, Zero-Inflated ordinal random effects model and (k,l)-Inflated ordinal random effects model are also given. The model is applied to a real social data set from the first two waves of the national longitudinal study of adolescent to adult health (Add Health study). In this data set, the joint responses are the number of days in a month that each individual smoked as the count response and the general health condition of each individual as the ordinal response. For the count response there is incidence of excess values of 0 and 30.     

Confidence interval estimation and hypothesis testing for a common correlation coefficient

Several procedures have been proposed for testing the hypothesis that all off-diagonal elements of the correlation matrix of a multivariate normal distribution are equal. If the hypothesis of equal correlation can be accepted, it is then of interest to estimate and perhaps test hypotheses for the common correlation. In this paper, two versions of five different test statistics are compared via simulation in terms of adequacy of the normal approximation, coverage probabilities of confidence intervals, control of Type I error, and power. The results indicate that two test statistics based on the average of the Fisher z-transforms of the sample correlations should be used in most cases. A statistic based on the sample eigenvalues also gives reasonable results for confidence intervals and lower-tailed tests.     

中华武术散打之局部力量与整体力量解读

散打之力量是散打运动中除运动技术等要素外,非常重要的另一要素,散打之力量在运动中表现出两个方面的应用,即散打之局部力量和整体力量;散打之局部力量和整体力量在比赛中交替展现,正是由于散打之局部力量和整体力量的不停变换使用及不同情况下各种力量共同作用,运动员才能在比赛中赢得胜利。散打之局部力量与整体力量的科学应用与训练不仅塑造了练习者完美的运动身形,而且培养了个人不凡的运动气质,是一项完美的体育运动。     

高兹资本主义核电技术批判理论及其当代价值

高兹是法国当代左翼生态政治思想家,他以法国发展核电技术为例,从技术、经济、生态和安全方面对资本主义使用的核电技术进行了深刻的分析和批判。他指出核电技术是"资本的圈套",符合资本主义积累逻辑,是资本主义专制的政治选择,社会生态重建的基本前提是工具转换。高兹的核电批判理论为我们审视目前的能源发展战略提供了一种新的理论视野,他对节约能源以及采用新技术发展新型能源的思考,对建设生态文明具有重要的价值。     

智库建设的困境摆脱与国家软实力提升

智库是国家软实力的重要体现。改革开放以来，国家软实力的提升为智库建设的机制创新创造了有利条件。但在新时期新的历史条件下，由于体制内官方智库的非自主性、体制外智库发展的滞后性、智库设置和定位的模糊化、智库建设和发展的保障不足等仍影响着国家软实力的提升。不断加强官方智库建设，高度重视半官方智库建设，加大民间智库的扶持力度，引导大学附属型智库的积极发展，建立各类智库的互动合作机制，是我国进一步提升国家软实力的必由之路。     

The logic of strategic ignorance

Ignorance and knowledge are often thought of as opposite phenomena. Knowledge is seen as a source of power, and ignorance as a barrier to consolidating authority in political and corporate arenas. This article disputes this, exploring the ways that ignorance serves as a productive asset, helping individuals and institutions to command resources, deny liability in the aftermath of crises, and to assert expertise in the face of unpredictable outcomes. Through a focus on the Food and Drug Administration's licensing of Ketek, an antibiotic drug manufactured by Sanofi-Aventis and linked to liver failure, I suggest that in drug regulation, different actors, from physicians to regulators to manufacturers, often battle over who can attest to the least knowledge of the efficacy and safety of different drugs - a finding that raises new insights about the value of ignorance as an organizational resource.     

The State of Research in Latino Academic Attainment

In this essay, I present an interdisciplinary examination of the state of research in Latino education, addressing not only the cultural forces influencing Latinos’ educational attainment, but also the structural conditions faced by them—as a racialized minority group—throughout their schooling and that have a cumulative effect on their academic attainment. Overall, I suggest that by engaging in a critical review of the literature on Latinos’ educational attainment, the reader will acknowledge that the racially driven hierarchical structural arrangements are highly responsible for the patterns observed.