Estimation of Acute Toxicity by Fitting a Dose-Time-Response Surface

In acute toxicity testing, organisms are continuously exposed to progressively increasing concentrations of a chemical and deaths of test organisms are recorded at several selected times. The results of the test are traditionally summarized by a dose-response curve, and the time course of effect is usually ignored for lack of a suitable model. A model which integrates the combined effects of dose and exposure duration on response is derived from the biological mechanisms of aquatic toxicity, and a statistically efficient approach for estimating acute toxicity by fitting the proposed model is developed in this paper. The proposed procedure has been computerized as software and a typical data set is used to illustrate the theory and procedure. The new statistical technique is also tested by a data base of a variety of chemical and fish species.     

Ownership Identity and Concentration: A Study of their Joint Impact on Corporate Diversification

This paper examines the impact of ownership on product and international diversification. While ownership concentration has received considerable attention from agency theorists we argue that a more nuanced analysis is necessary. We consider how the identity of owners moderates the impact of ownership concentration on diversification strategies. We develop a framework that explains how the combination of different motivations, resources and capabilities associated with different types of owners results in significantly variable relationships between ownership concentration and both product and international diversification. From a theoretical perspective this suggests a social contextualization and extension of the agency theoretic approach that characterizes the field. Based on a study of 222 European firms between 1994 and 2007 we show that family ownership concentration has a positive impact on product and a negative impact on international diversification while the impact of institutional and state ownership concentration is negative on product diversification and positive on international diversification compared with family ownership. This is the first study to provide a comprehensive framework explaining how ownership concentration and identity interact and affect both international and product diversification.     

Voluntary Counselling Services in Melbourne: A Survey

The paper reports on a survey of aspects of counselling services provided by 83 voluntary organisations operating in the Melbourne metropolitan area. Information was obtained on the types of counselling services provided, clients making use of the services, and the selection and supervision of counsellors. The findings showed that the voluntary sector of organisations providing counselling services is both highly active and very heterogeneous.     

Average rank correlation statistics in the presence of ties

The problem of n judges ranking r objects is considered in the situation where ties are permitted. Asymtotic distributions under the null hypothesis of complete randomness in the rankings are derived for the test statistics of average rank correlations between all pairs of ranking where the rank correlations are measured either by Spearman rho or Kendall tau. The relative efficeincies of these average rank correlatins are derived using approximate Bahadur slope and limiting pitman efficiency, and in both cases the Kendall statistic is shown to be more efficient. Some interpretatins of these and related results are also given.     

Erfolgsfaktoren bei der Integration von Coaching und Entwicklungsprogrammen

Success factors for the integration of coaching and development programs This article describes possible ways to combine coaching and development programs for managers, that are based on the author’s practical experience. Such a combination can lead to a more intense and more sustainable competence growth than each individual approach. Both coaching and development program benefit from a combination. Adequately, a high level of integration is desirable. Such an integration will be successful if the structure of the program allows for embedding, special characteristics of the target group are considered, non-threatening labels are used, and the coaches/trainers are able to build a coherent bridge between the single elements.     

Analysis of the cross-effects in a cross-lagged panel study

Panel studies are statistical studies in which two or more variables are observed for two or more subjects at two or more points in time. Cross-lagged panel studies are comprised of continuous variables which divide naturally into two sets, and otten the primary statistical issue Is to estimate and test the cross-effects which indicate the degree to which each set is related to the other over time. By taking a regression approach to modeling the relationships, we apply multivariate regression methodology to make inferences about the regression coefficients in a cross-lagged panel model. In particular we develop a test of the hypothesis that the regression coefficients indicating the cross-effects are equal and develop simultaneous confidence bounds for various linear combinations of these regression coefficients.     

Rural social work The perceptions and experiences of five remote practitioners

Abstract

Living and working as a remote, rural social worker is a challenging experience. This qualitative study explores the experiences of five longer-term social workers in rural Western Australia. It provides a glimpse of their world including initial experiences, factors which support long-term rural practice, the demands and skills needed, the difficulties working in a bureaucracy and the positive aspects of rural practice. Tentative conclusions indicate that rural practice is distinct, due to the demands of living and working in the same community. Moreover, skills must be applied in the context of few secondary referral points or after hours services, and huge distances. The difficulty of maintaining professional identity and feelings of personal isolation are significant, but are compensated for by families who are settled and reluctant to leave, These findings can be used to inform social work education and improve retention of workers and quality of rural practice.