Modelling mercury deposition through latent space–time processes

Summary.  The paper provides a space–time process model for total wet mercury deposition. Key methodological features that are introduced include direct modelling of deposition rather than of expected deposition, the utilization of precipitation information (there is no deposition without precipitation) without having to construct a precipitation model and the handling of point masses at 0 in the distributions of both precipitation and deposition. The result is a specification that enables spatial interpolation and temporal prediction of deposition as well as aggregation in space or time to see patterns and trends in deposition. We use weekly deposition monitoring data from the National Atmospheric Deposition Program–Mercury Deposition Network for 2003 restricted to the eastern USA and Canada. Our spatiotemporal hierarchical model allows us to interpolate to arbitrary locations and, hence, to an arbitrary grid, enabling weekly deposition surfaces (with associated uncertainties) for this region. It also allows us to aggregate weekly depositions at coarser, quarterly and annual, temporal levels.     

Simultaneous prediction intervals for all patrwise differences among several future sample means

Hahn (1977) suggested a procedure for constructing prediction intervals for the difference between the means of two future samples from normal populations having equal variance, based on past samples selected from both populations. In this paper, we extend Hahn's work by constructing simultaneous prediction intervals for all pairwise differences among the means of k ≥ 2 future samples from normal populations with equal variances, using past samples taken from each of the k populations. For K = 2, this generalization reduces to Hahn's special case. These prediction intervals may be used when one has sampled the performance of several products and wishes to simultaneously as- sess the differences in future sample mean performance of these products with a predetermined overall coverage probability. The use of the new procedure is demonstrated with a numerical example.     

Relevance of Direct Practice for Today's Social Work Educator

This paper attempts to bring together some of the strands in general learning and instructional theories and the conceptualizations growing out of contemporary education theory and practice that may be helpful to sensitizing the teacher in continuing education to the problems and potentials in the learning-teaching situation.     

Condom Negotiation Strategy Use and Effectiveness among College Students

College students may engage in risky sexual behaviors, such as inconsistent condom use, which increase their risk of sexually transmitted infections. This study examined the association between six condom influence strategies (CIS) and reported condom use among a diverse group of college students. Differences in CIS and condom use were examined by gender, race or ethnicity, and relationship status (casual, monogamous, or no current relationship). The study also used a cluster analysis to investigate how the CIS were used relative to one another, and how patterns of CIS use were related to condom use. Results showed interesting differences in CIS use by gender, race or ethnicity, and relationship status. Four patterns of CIS usage emerged, and results suggested that using all CIS frequently and using more assertive CIS may be particularly important for increased condom use. Men reported more condom use than women overall, but results indicated that using CIS were especially vital for increasing condom use for women. Surprisingly, there were no differences in condom use found for race or ethnicity and relationship type. Programs aimed at increasing students' condom use could benefit from promoting and practicing CIS, and recognizing potential differences among demographic groups.     

Problems and Issues in Social Casework,by Scott Briar and Henry Miller. New York,Columbia University Press, 1971. 274 Pages, $9.00. Hardbound

Abstract

The rapid growth and increasing visibility of ethnic and racial groups has vigorously challenged social work to educate students for ethnic-competent practice in cross-cultural settings. This article examines an approach to teaching effective intervention involving ethnic and racial groups and helping students integrate cultural factors and society's concerns into clinical practice. Pedagogical issues and classroom processes of teaching culturally sensitive and competent interpersonal practice are discussed. Implications are drawn for culturally sensitive education and issues are raised for critical examination.     

The assessment relationship: interactions between social workers and parents in child protection assessments

Summary This paper is concerned with a relatively unresearched areaof child protection practice: the comprehensive assessment.The study comprises qualitative research of social workers conductingthese assessments. Sixteen assessments are analysed in detail.It is noted that these assessments, like many other in-depthsocial work assessments, are mainly based on verbal interactions.Some of the core evidence cited by social workers as formingthe basis of their assessment decisions is based on verbal interactionbetween social workers and parents. Such verbal interactionsare viewed as being inextricably intertwined with the socialworker-client relationship. A particular aspect of the relationship,the ability to agree a plausible explanation for the familysituation, is highlighted as particularly important in determiningthe outcome of the assessment. The possible implications ofthese findings for assessment practices are outlined.     

An emotion-based model of risk perception and stigma susceptibility: cognitive appraisals of emotion, affective reactivity, worldviews, and risk perceptions in the generation of technological stigma.

A study (N=198) was conducted to examine hypotheses derived from an emotion-based model of stigma responses to radiation sources. A model of stigma susceptibility is proposed in which affective reactions and cognitive worldviews activate predispositions to appraise and experience events in systematic ways that result in the generation of negative emotion, risk perceptions, and stigma responses. Results of structural equation modeling supported the hypotheses. Radiation sources that scored higher on a measure of stigma were included in the analyses (i.e., nuclear power plants, radioactive waste from nuclear power plants, radiation from nuclear weapons testing). Individual differences in negative reactivity and worldviews were associated with the strength of emotional appraisals that were associated, in turn, with negative emotion toward stigmatized radiation sources. As hypothesized, the model fit better with perceived risk as a function of negative emotion rather than vice versa. Finally, a measure of stigma was associated with negative emotion and, to a lesser extent, with risk perceptions. Risk communication about stigmatized objects may benefit from a more complete understanding of how affective and emotional reactions are constructed and the routes through which they affect responses and behaviors.