Bayesian palaeoclimate reconstruction

Summary.  We consider the problem of reconstructing prehistoric climates by using fossil data that have been extracted from lake sediment cores. Such reconstructions promise to provide one of the few ways to validate modern models of climate change. A hierarchical Bayesian modelling approach is presented and its use, inversely, is demonstrated in a relatively small but statistically challenging exercise: the reconstruction of prehistoric climate at Glendalough in Ireland from fossil pollen. This computationally intensive method extends current approaches by explicitly modelling uncertainty and reconstructing entire climate histories. The statistical issues that are raised relate to the use of compositional data (pollen) with covariates (climate) which are available at many modern sites but are missing for the fossil data. The compositional data arise as mixtures and the missing covariates have a temporal structure. Novel aspects of the analysis include a spatial process model for compositional data, local modelling of lattice data, the use, as a prior, of a random walk with long-tailed increments, a two-stage implementation of the Markov chain Monte Carlo approach and a fast approximate procedure for cross-validation in inverse problems. We present some details, contrasting its reconstructions with those which have been generated by a method in use in the palaeoclimatology literature. We suggest that the method provides a basis for resolving important challenging issues in palaeoclimate research. We draw attention to several challenging statistical issues that need to be overcome.     

Comparing Expressed and Revealed Preferences for Risk Reduction: Different Hazards and Question Frames

Studies often note the wide differences that exist in costs per death avoided across U.S. federal programs and regulatory contexts. This paper explores two new, related explanations for these differences. First, it argues that the patterns of revealed preferences (public allocations) may be related to public values, which are measured here through subjects' expressed preference responses to a contingent valuation survey regarding risk reduction. Subjects' expressed values are compared to actual (and proposed) costs of safety regulations for a similar set of hazards. We discover strong congruence in the ranking of expressed values and actual values. Second, the paper presents the results of a subsequent survey that investigates why the patterns observed in the first survey might occur. It suggests that one reason for the observed similarities between revealed and expressed preferences may be in how choices are framed. The paper hypothesizes that both subjects and decision makers may frame valuation decisions in the same way: as percentage changes from the reference point provided by the base rate of deaths for that hazard.     

How Close Is Close Enough: Public Perceptions of the Risks of Industrial Facilities

Public opinion poll data have consistently shown that the proportion of respondents who are willing to have a nuclear power plant in their own community is smaller than the proportion who agree that more nuclear plants should be built in this country. Respondents' judgments of the minimum safe distance from each of eight hazardous facilities confirmed that this finding results from perceived risk gradients that differ by facility (e.g., nuclear vs. natural gas power plants) and social group (e.g., chemical engineers vs. environmentalists) but are relatively stable over time. Ratings of the facilities on thirteen perceived risk dimensions were used to determine whether any of the dimensions could explain the distance data. Because the rank order of the facilities with respect to acceptable distance was very similar to the rank order on a number of the perceived risk dimensions, it is difficult to determine which of the latter is the critical determinant of acceptable distance if, indeed, there is only one. There were, however, a number of reversals of rank order that indicate that the respondents had a differentiated view of technological risk. Finally, data from this and other studies were interpreted as suggesting that perceived lack of any other form of personal control over risk exposure may be an important factor in stimulating public opposition to the siting of hazardous facilities.     

Determinants of sexual arousal and accuracy of its self-estimation in sexually functional males

Men with and without sexual dysfunction present with varying patterns of agreement between subjective estimates of sexual arousal and more objective psychophysiological measures of the same construct. This relative accuracy seems to be associated with sexual function, with men who have sexual dysfunction presenting less accurate estimations (mostly reporting below measured arousal levels). The purpose of this study is to clarify the processes underlying sexual arousal and the accuracy of its self-estimation. We looked at potential predictors of sexual arousal (subjective and physiological) and accuracy in estimating objective sexual arousal in a sample of 60 sexually functional males. Predictors included pre-existing sexual attitudes (erotophobia), both trait and state positive and negative affect, self-focused attention, and interoceptive awareness. Results indicate that this sexually functional sample generally reported below their own erection level. Interestingly, trait negative affect was associated with somewhat lower levels of subjective arousal and higher levels of physiological arousal. On the other hand, state positive affect facilitated both subjective and objective arousal and increased somewhat the accuracy of estimates of erectile responding. Pre-existing sexual attitudes as well as variations in self-focused attention and interoceptive awareness evidenced little effect on sexual arousal or the accuracy of its estimation.     

Family member response to violent infant kidnapping

All family members interviewed suffered from chronic posttraumatic stress disorder 5 or more years after an infant kidnapping. Psychiatric nurses should routinely assess for secondary victimization related to any type of traumatic stressor. Nurses should refer parents and families to materials available from the National Center for Missing and Exploited Children (NCMEC) (http://www.missingkids.com/).     

Bridging child welfare and juvenile justice: preventing unnecessary detention of foster children

Gaps in service coordination between child welfare and other child-serving agencies are well documented. This article examines the gap between the child welfare and juvenile justice systems and discusses a program, Project Confirm, designed to reduce the problems associated with this gap. Project Confirm aims to improve cooperation between juvenile justice and child welfare agencies to prevent the unnecessary detention of arrested foster children in secure facilities. The program's design is outlined, and implementation statistics and government partner perceptions of the program in its first year of operations are provided. The article also identifies future challenges to implementation and discusses the broader implications of the program. In making this appeal for coordination and collaboration among public agencies, I'm not talking about pro forma integration efforts-I'm not talking about memoranda of understanding or top-level reorganizations that have autonomous agencies vaguely reporting to a single box labeled "human services." Rather, I'm talking about the much more challenging objective of achieving real working partnerships at the front line. (Nelson, 1998, p. 6)     

Challenging the one-size-fits-all myth: findings and solutions from a statewide focus group of rural social workers

Of America's counties, 76% are rural, comprising 83% of U.S. land and 25% of the American population. Yet most child welfare programs are designed to fit the needs of urban and suburban families. This article reviews the unique needs and assets of rural children and families in Texas. It presents recommendations from a focus group for overcoming the inappropriate transfer of urban models to rural communities.     

How physician-employees experience their work lives in a changing HMO

The present study advances our understanding of both physician adaptation and the physician-organization relationship in a managed care environment defined by structural diversity and constant change. It does so through a longitudinal examination of a single group of physician-employees experiencing their work lives within a nonprofit health maintenance organization (HMO) in the midst of major strategic developments. Using interview, observation, and archival data collected over a five-year period, the analysis reveals that the form and substance of individual physician adaptation to organizational life is dependent upon social exchanges over time with the HMO, making it an emergent, evolutionary process rather than a pre-determined, static phenomenon. However, the results also demonstrate that physician adaptive response to rapid, unpredictable organizational change is slow and delayed, in particular when this change makes physicians more dependent on their employing organization. This confers an advantage onto the organization vis-à-vis professionals in interpreting and responding to environmental change. These insights should encourage sociologists to employ research designs and contingency models of physician attitudes and behavior that capture the dynamic and particularistic nature of everyday physician work life in contemporary health care.     

The Gambling Self-Efficacy Questionnaire: An Initial Psychometric Evaluation

Instruments to assess individuals' self-efficacy for the control of addictive behaviors have been useful for monitoring behavior change, predicting maintenance of treatment gains, and identifying potential relapse situations. The Gambling Self-Efficacy Questionnaire (GSEQ) was developed to assess perceived self-efficacy to control gambling behavior. A demographically diverse sample of 309 adult gamblers completed an initial set of 42 items, of which 16 were selected to form the final version of the GSEQ. The GSEQ showed high internal consistency ( = .96) and good test-retest reliability (r = .86). A factor analysis provided some support for a unitary factor structure. As expected, GSEQ scores were negatively correlated with reports of problematic gambling behavior. Participants experiencing problems related to their gambling behavior scored significantly lower on the GSEQ than those who were not experiencing gambling problems. This psychometric examination of the GSEQ supported its potential utility for treatment planning and outcome evaluation with problem gamblers.