Affirmation effects on math scores: The importance of high school track

Stereotype threat has been shown to affect academic performance of minority racial groups. Minority girls may experience the burdens of both race and gender - a “double bind” theorized to affect the underrepresentation of women in STEM fields. A randomized controlled trial focused on alleviating stereotype threat in three high schools in a large U.S. metro demonstrates the effects of affirmative writing interventions, which have previously shown positive effects for minority and female students. Results indicate effects for these groups were insignificant. However, results also show that student track is highly significant at p < 0.001, and interactive analyses suggest that the intervention may help alleviate threat for higher-achieving students.     

Robust block bootstrap panel predictability tests*

This article develops two block bootstrap-based panel predictability test procedures that are valid under very general conditions. Some of the allowable features include cross-sectional dependence, heterogeneous predictive slopes, persistent predictors, and complex error dynamics, including cross-unit endogeneity. While the first test procedure tests if there is any predictability at all, the second procedure determines the units for which predictability holds in case of a rejection by the first. A weak unit root framework is adopted to allow persistent predictors, and a novel theory is developed to establish asymptotic validity of the proposed bootstrap. Simulations are used to evaluate the performance of our tests in small samples, and their implementation is illustrated through an empirical application to stock returns.     

矿渣MTC胶结物抗腐蚀性能研究

随着矿渣MTC技术的发展和应用,矿渣MTC胶结物的抗腐蚀性能日益受到人们的关注。矿渣MTC胶结物的抗腐蚀性能直接关系到矿渣胶结物后期性能,并影响井和套管的使用寿命。分析了矿渣MTC胶结物可能受到的几种腐蚀类型及其机理,实验验证了矿渣胶结物具有较强的抗NaCl、Na₂CO₃、Na₂SO₄、MgSO₄侵蚀的能力,但易受酸性介质腐蚀;实验发现了加入胶乳能较大幅度提高矿渣胶结物抗酸性介质腐蚀的能力,并对胶乳提高矿渣胶结物抗酸蚀能力的原因进行了分析。     

Therapeutic Assessment with Children in Family Therapy

Therapeutic Assessment with Children (TA‐C) is a brief semi‐structured intervention in which psychological assessment is used to help families with children and adolescents to change. In this paper we introduce the TA‐C model, describe its semi‐structured format and exemplify how it can be applied by family therapists.     

用工业CT技术测量储层岩芯饱和度分布

认识储层岩石中含油饱和度及饱和度分布,对驱替机理的深入研究是非常重要的。为了搞清储层岩石在驱替过程中的饱和度分布情况,应用工业CT技术,提出了一种储层含油岩芯被驱替后的饱和度分布的CT密度差测量方法。在岩样的同一断面,分别对干岩样、饱和岩样及在驱替后的岩样进行CT扫描,重建相应的断层图象,测量所建图象的灰度值,计算出相应的密度值,用密度差法计算出饱和度及其分布值。在γ射线工业CT机“CD-300BG”上对某油田岩样进行了实际测量,获得的结果说明,采用CT密度差法测量饱和度分布是有效的。该方法与常规驱替法相比较,具有快速、精度高、无损岩样和能模拟地层状态测量等特点,是油田开发、油藏描述和地层评价的一种新的有效方法。     

Peer and Friend Influences on Children's Eating

Peers and friends are perceived as important role models for the formation of children's attitudes and behaviours. A wealth of research has aimed to establish the contribution of peers and friends to children's developing eating behaviours, and their attitudes towards eating. This review describes and evaluates such research. Experimental research examining peer modelling of food consumption and liking is reviewed, and several individual child factors that are suggested to make children more or less receptive to peer and friend influences are discussed. The influence of children's perceptions of their peers’ and friends’ eating behaviours upon their own eating practices is also explored. The benefits of future longitudinal research to improve understanding of peer and friend influences on children's eating are emphasized.     

Testing for a change point in a sequence of exponential random variables with repeated values

Two test statistics are proposed for the change-point problem with repeated values when the data follow an exponential distribution. The properties of these two statistics have been studied and their asymptotic distributions under the alternative have been derived. The powers of the two test statistics are compared. Real-data examples are presented to illustrate the application of these tests.     

“社会企业”与“食物银行”:澳门特区的社会管理创新刍议

伴随着经济的飞速发展,社会管理体制绝不能产生任何滞后。随着经济社会各领域发生深刻地变化,由政府高度主导的社会管理模式亦需要与时俱进地创新。作为国家特别行政区之一的澳门,近年来在经济上取得长足发展、政府公共财政收入颇为理想的情况下,不断探索"以民为本"的社会管理模式,努力辅助弱势社群,解决社会问题,持续营造良好的社会环境,促进社会和谐。澳门特区近年来推出的"社会企业"和"食物银行",是澳门政府现阶段社会管理的着力举措,体现出澳门特区的社会管理体制创新的特点。     

A Five-Decision Testing Procedure to Infer the Value of a Unidimensional Parameter

ABSTRACT

A statistical test can be seen as a procedure to produce a decision based on observed data, where some decisions consist of rejecting a hypothesis (yielding a significant result) and some do not, and where one controls the probability to make a wrong rejection at some prespecified significance level. Whereas traditional hypothesis testing involves only two possible decisions (to reject or not a null hypothesis), Kaiser’s directional two-sided test as well as the more recently introduced testing procedure of Jones and Tukey, each equivalent to running two one-sided tests, involve three possible decisions to infer the value of a unidimensional parameter. The latter procedure assumes that a point null hypothesis is impossible (e.g., that two treatments cannot have exactly the same effect), allowing a gain of statistical power. There are, however, situations where a point hypothesis is indeed plausible, for example, when considering hypotheses derived from Einstein’s theories. In this article, we introduce a five-decision rule testing procedure, equivalent to running a traditional two-sided test in addition to two one-sided tests, which combines the advantages of the testing procedures of Kaiser (no assumption on a point hypothesis being impossible) and Jones and Tukey (higher power), allowing for a nonnegligible (typically 20%) reduction of the sample size needed to reach a given statistical power to get a significant result, compared to the traditional approach.