Evaluation of two school‐based HIV prevention interventions in the border city of Tijuana,Mexico

This research project examined the individual and combined effectiveness of an HIV prevention workshop and a free condom distribution program in four high schools in Tijuana, Mexico. Adolescents (N = 320) completed baseline measures on sexual practices and theoretical correlates and participated in a two‐part study. In Study I, students were randomly assigned to an HIV prevention workshop or a control condition, with a 3‐month follow‐up assessment. Results indicate three significant workshop benefits regarding HIV transmission by altering sexual initiation, access to condoms, and traditional beliefs regarding condoms. In Study 2, we set up a condom distribution program at two of the participating schools, and students completed a 6‐month follow‐up assessment. Results indicate that exposure to the workshop followed by access to the condom distribution program yielded two beneficial results for reducing HIV transmission: moderating sexual initiation and increasing condom acquisition. Access to the condom distribution program alone had no effects on behavioral and psy‐chosocial correlates of HFV transmission. We discuss implications of these results.     

Trade, education, and innovation: Prospects for the U.S. economy

This paper examines international trade issues as vital indicators of the economic prospects of the United States and other developed economies. In particular, it challenges misuses of the doctrine of mutual gains from trade and instead argues that comparative advantage does not guarantee increases in benefits to both trading partners—especially when one partner seeks to distort the market mechanism in its favor. In the face of such mercantilist or protectionist practices, efforts to advance innovation, without retaining manufacturing jobs, will not ensure continued prosperity, as the number of jobs entailed in the invention process is small compared with the number of jobs associated with manufacturing an innovative product for mass consumption. These matters call for the urgent rethinking of trade policy by the United States and other developed nations, if they are to balance their imports and exports and ensure continued economic growth.     

Projektmanagement mit virtuellen Teams?

Globalisation and internationalisation of organisations as well as fast-paced development of modern electronic communication technologies require and support the implementation of globally distributed project teams. Members are working together in different locations and in different time zones. These facts have an impact on project work. This article tries to critically reflect the work of virtual project teams and it tries to answer the question, if we can speak about teamwork under such circumstances.     

Sex,Arts and Verbal Abilities: Three Further Indicators of How American Life is not Improving

Despite clear evidence that Americans’ economic standard of living has improved over the last half-century in terms of income, ownership of technology and housing among other indicators, there is scant evidence from non-economic quality-of-life (QOL) indicators of improved life quality to parallel these economic gains. The present article adds to this list in showing little if any progress in three QOL indicators (the first two about time and activity) that have received less or no attention in the social indicators literature, namely (1) frequency of the highly enjoyable activity of sex, (2) participation in various serious arts activities and (3) scores of verbal ability. The data on sexual activity and verbal ability come from the 1974–2008 General Social Surveys (GSS) from the University of Chicago, and for the arts from the 2008 Survey of Public Participation in the Arts (SPPA) conducted by the US Census Bureau for the National Endowment for the Arts since 1982. All three surveys interviewed nationally representative samples, with over 70% response rates and sample sizes of more than 15,000 adults. The GSS data on sexual frequency show no significant increase in estimated frequency of sex since 1989, despite its strong appeal and the availability of new societal conveniences. This held both before and after adjustment for the age, marital status and education in the population; contrary to expectation, working long hours was associated with increased sex both before and after adjustment for these other demographic predictors. The SPPA trend data on arts participation actually showed a decline in participation, especially after adjustment for its major predictor of years of education; again no decreased participation was found among those working long hours. While scores on verbal ability in the GSS have stayed rather steady since 1974, they have decreased after MCA adjustment for the increased college education in more recent years, as documented by Nie et al. (2009). Thus, contrary to expectations, increases in public education have not been accompanied by improvements on these three indicators.     

Nanotechnology Risk Communication Past and Prologue

Nanotechnologies operate at atomic, molecular, and macromolecular scales, at scales where matter behaves differently than at larger scales and quantum effects can dominate. Nanotechnologies have captured the imagination of science fiction writers as science, engineering, and industry have leapt to the challenge of harnessing them. Applications are proliferating. In contrast, despite recent progress the regulatory landscape is not yet coherent, and public awareness of nanotechnology remains low. This has led risk researchers and critics of current nanotechnology risk communication efforts to call for proactive strategies that do more than address facts, that include and go beyond the public participation stipulated by some government acts. A redoubling of nanotechnology risk communication efforts could enable consumer choice and informed public discourse about regulation and public investments in science and safety.     

The eigenstructure of block-structured correlation matrices and its implications for principal component analysis

Block-structured correlation matrices are correlation matrices in which the p variables are subdivided into homogeneous groups, with equal correlations for variables within each group, and equal correlations between any given pair of variables from different groups. Block-structured correlation matrices arise as approximations for certain data sets’ true correlation matrices. A block structure in a correlation matrix entails a certain number of properties regarding its eigendecomposition and, therefore, a principal component analysis of the underlying data. This paper explores these properties, both from an algebraic and a geometric perspective, and discusses their robustness. Suggestions are also made regarding the choice of variables to be subjected to a principal component analysis, when in the presence of (approximately) block-structured variables.     

明代队来青海草场冲突纠纷及解决路径述略

本文通过梳理和分析明代以来青海草场纠纷及解决路径,认为处理草场纠纷时不仅要以一种开放、稳健而宽容的多元文化态度,尊重地方性文化和民间解纷机制,而且还需要用人类普同性价值即当代社会倡导的社会主义核心价值观来思考、看待与处理草场纠纷.