Bootstrapping regression models with BLUS residuals

To bootstrap a regression problem, pairs of response and explanatory variables or residuals can be resam‐pled, according to whether we believe that the explanatory variables are random or fixed. In the latter case, different residuals have been proposed in the literature, including the ordinary residuals (Efron 1979), standardized residuals (Bickel & Freedman 1983) and Studentized residuals (Weber 1984). Freedman (1981) has shown that the bootstrap from ordinary residuals is asymptotically valid when the number of cases increases and the number of variables is fixed. Bickel & Freedman (1983) have shown the asymptotic validity for ordinary residuals when the number of variables and the number of cases both increase, provided that the ratio of the two converges to zero at an appropriate rate. In this paper, the authors introduce the use of BLUS (Best Linear Unbiased with Scalar covariance matrix) residuals in bootstrapping regression models. The main advantage of the BLUS residuals, introduced in Theil (1965), is that they are uncorrelated. The main disadvantage is that only n —p residuals can be computed for a regression problem with n cases and p variables. The asymptotic results of Freedman (1981) and Bickel & Freedman (1983) for the ordinary (and standardized) residuals are generalized to the BLUS residuals. A small simulation study shows that even though only n — p residuals are available, in small samples bootstrapping BLUS residuals can be as good as, and sometimes better than, bootstrapping from standardized or Studentized residuals.     

《左传》的幽默讽刺艺术

幽默讽刺是贯穿《左传》的一个重要特色 ,存在于作品的材料选取、情节提炼、人物刻画、叙事安排、语言运用等诸多方面 ,使全书具有一种独特的魅力     

Gender inequalities in European unemployment benefit systems

The most important structural change which has occurred on the labour market over the past 30 years is the sustained and continued growth of female labour supply. Two-earner couples have become a majority in most European countries and lone parents, mostly women, are also on the rise. On the other hand, since 1975, labour market policies have altered the quality and nature of employment in Europe by promoting atypical forms of employment where women are overrepresented. The analysis has shown us that atypical employment results in restricted access to unemployment benefits. Moreover, combining the presence of more stringent conditions with derived rights results in more and more women being dependent upon their spouses for financial as well as social protection and can even have a disincentive effect on formal labour market participation.     

Are plant communities mainly determined by anthropogenic land cover along urban riparian corridors?

Often used as a mitigation tool to landscape fragmentation, urban riparian corridors also suffered from the effects of the urban expansion. This study explored the relationships between plant riparian communities and two major environmental variables (land cover, soil characteristics) and analyzed the floristic change along an urbanization gradient. Fifteen sites were surveyed on both riverbanks of two riparian corridors characterized by contrasting water regimes in Strasbourg, North Eastern France. Data of spontaneous species abundance was collected from 180 quadrats using (i) all plant species, (ii) herbaceous stratum and (iii) ligneous stratum (bush and tree). The diversity and compositional patterns of riparian plant species were analyzed within each corridor according to three levels of urbanization (urban, suburban, peri-urban). Relationships between riparian communities, land cover and soil chemical properties (pH, nitrogen and carbon content, moisture) were established by between-class co-inertia analyses. Land cover emerged as the main factor explaining changes in riparian communities along the rural–urban gradient while soil chemical properties discriminate water stress and fluvial dynamics of the two corridors. Similar compositional patterns were found within the most urbanized sites with the establishment of ubiquitous species. The herbaceous stratum is best linked to the level of urbanization, whereas the tree stratum is primarily correlated with corridor attributes (hydrological regime, soil properties). Although riparian species and communities are mainly determined by land cover, urban riparian corridors maintain native biodiversity up to the urban center.     

Self-Reported Personal Well-Being of Youth Accessing Intensive Mental Health Treatment

Normative samples have been shown to rate their personal wellbeing (PWB) as positively high and high PWB is associated with many enduring benefits. Cummins (J Happiness Stud 10(6):1–17, 2009) has suggested that PWB has an equilibrium that is set at a rather high positive state and maintained through psychological mechanisms he termed homeostatic protected mood (HPM). Investigators who have explored PWB and mental health disorders have often focused on schizophrenia in adult populations, with varied results, and scant attention has been paid to clinical samples of youth with emotional and/or behavioral disorders. The purpose for this report was to explore the level of PWB reported by a subsample of youth who accessed residential treatment (n = 30) and intensive home based treatment (n = 33) at 12–18 months post-discharge, and explore whether clinical variables could predict PWB. Many youth reported high PWB despite experiencing continued challenges in symptoms and psychosocial functioning. Demographic and clinical characteristics did not predict participants’ PWB scores, lending support for the HPM theory with this sample of youth with emotional and behavioral disorder.     

Adjustment for nonresponse with variables from different sources: Bias correction and precision loss,with application to the Swiss European Social Survey 2012

ABSTRACT

Adjustment for nonresponse should reduce the nonresponse bias without decreasing the precision of the estimates. Adjustment for nonresponses are commonly based on socio-demographic variables, although these variables may be poorly correlated with response propensities and with variables of interest. Such variables nevertheless have the advantage of being available for all sample units, whether or not they are participating in the survey. Alternatively, adjustment for nonresponse can be obtained from a follow-up survey aimed at sample units which did not participate in the survey and from which the variables are designed to be correlated with response propensities. However, information collected through these follow-up surveys is not available for people in the sample who participated neither in the survey nor in its nonresponse follow-up. These two sets of variables when used in a nonresponse model for the Swiss European Social Survey 2012 differ only slightly with regard to their effect on bias correction and on the precision of estimates. The variables from the follow-up are performing slightly better. In both cases, the adjustment for nonresponse performs poorly.     

The social security number: A small device underpinning big systems

The possession and use of a personal social security number helps to structure people's daily lives. However, despite its fundamental normative importance, the social security number remains a little‐known entity. Increasingly universal and yet diverse in form, it is a legal and technical norm which is as much a mechanism for surveillance and monitoring as it is a necessary instrument for giving effect to social rights. Analysis of this constituent element of social security systems permits as assessment of some of the technical difficulties presented by the ever‐increasing movement of people and data. Overcoming these technical difficulties should permit to envisage a first technical step towards realizing a universal and global social security system.     

Das 360-Grad-Feedback zur Unterstützung der Kompetenzerweiterung von Führungskräften

Zusammenfassung:  Der Beitrag beschreibt die Einbettung des 360-Grad-Feedbacks in ein Programm der Führungskr?fteentwicklung. 360-Grad-Feedback ist eine Voraussetzung für die systematische Kompetenzentwicklung der Führungskr?fte eines Unternehmens. Darüber hinaus k?nnen die Entwicklungs- und Lernm?glichkeiten, die ein individuelles Coaching bietet, durch ein vorheriges 360-Grad-Feedback optimiert werden. Die bei ThyssenKrupp Services mit dem F?rderprogramm „best-for-best“ gesammelten Erfahrungen zeigen deutlich, dass die Kombination von einem 360-Grad-Feedback mit gezielten Coaching-Angeboten ein echtes Erfolgsmodell darstellt.

论创新教育与大学生课外科技活动

介绍了大学开展创新教育的意义及对大学生的影响 ,论述了创新教育与大学生课外科技活动的关系 ,即创新教育是大学生课外科技活动出成果的前提 ,大学生课外科技活动是创新教育的新平台和主要形式 ,它既是创新教育的实践环节 ,检验着创新教育的成果 ,又丰富着创新教育的内涵 ,同时是提高大学生创新精神和能力的主要途径。提出了高校要多方面创造条件 ,深化大学生课外科技活动。