Slice sampling for simulation based fitting of spatial data models

An auxiliary variable method based on a slice sampler is shown to provide an attractive simulation-based model fitting strategy for fitting Bayesian models under proper priors. Though broadly applicable, we illustrate in the context of fitting spatial models for geo-referenced or point source data. Spatial modeling within a Bayesian framework offers inferential advantages and the slice sampler provides an algorithm which is essentially off the shelf. Further potential advantages over importance sampling approaches and Metropolis approaches are noted and illustrative examples are supplied.     

A Semi-Parametric Quantile Function Estimator for Use in Bootstrap Estimation Procedures

In this note we develop a new quantile function estimator called the tail extrapolation quantile function estimator. The estimator behaves asymptotically exactly the same as the standard linear interpolation estimator. For finite samples there is small correction towards estimating the extreme quantiles. We illustrate that by employing this new estimator we can greatly improve the coverage probabilities of the standard bootstrap percentile confidence intervals. The method does not reqiure complicated calculations and hence it should appeal to the statistical practitioner.     

Estimation of long-term trends and variation in avian survival probabilities using random effects models

We obtained banding and recovery data from the Bird Banding Laboratory (operated by the Biological Resources Division of the US Geological Survey) for adults from 129 avian species that had been continuously banded for > 24 years. Data were partitioned by gender, banding period (winter versus summer), and by states/provinces. Data sets were initially screened for adequacy based on specific criteria (e.g. minimum sample sizes). Fifty-nine data sets (11 waterfowl species, the Mourning Dove and Common Grackle) met our criteria of adequacy for further analysis. We estimated annual survival probabilities using the Brownie et al. recovery model {St, ft} in program MARK. Trends in annual survival and temporal process variation were estimated using random effects models based on shrinkage estimators. Waterfowl species had relatively little variation in annual survival probabilities (mean CV = 8.7% and 10% for males and females, respectively). The limited data for other species suggested similar low temporal variation for males, but higher temporal variation for females (CV = 40%). Evidence for long-term trends varied by species, banding period and sex, with no obvious spatial patterns for either positive or negative trends in survival probabilities. An exception was Mourning Doves banded in Illinois/Missouri and Arizona/New Mexico where both males (slope = -0.0122, se = 0.0019 and females (slope = -0.0109 to -0.0128, se = 0.0018 -0.0032) exhibited declining trends in survival probabilities. We believe our approach has application for large-scale monitoring. However, meaningful banding and recovery data for species other than waterfowl is very limited in North America.     

Do taboo trade-offs explain the difficulty in valuing health and social interventions?

Persistent anomalies in the results of willingness to pay studies, despite improvements in measurement technique, challenge the assumption in economics that all sources of value are commensurable. Two sources of incommensurability have been identified: interdimensional incommensurability, which refers to the cognitive difficulty that people encounter when trying to assign a monetary value to health; and constitutive incommensurability, which arises when some forms of trade-off are regarded as ‘taboo’. In this paper we explore whether the notion of taboo trade-offs might explain some of the difficulties experienced in health-related willingness to pay studies.     

EC anti-dumping laws as a barrier to trade

Anti-dumping (AD) laws in the EC are intended to establish ‘fairness’ between trading partners. But there are negative effects, in particular, firms with weak firm specific advantages can shelter behind AD laws; they can even follow shelter-based strategies and lobby for protection.Alan Rugman and Michael Gestrin explain how shelter can be used as a management strategy, and how AD laws have grown up in the EC since 1979 to affect sectors of industry and geographic regions. They conclude by pointing out that a shelter-based strategy by a strong firm can undermine the very competitive pressures in its home market that made it internationally competitive in the first place.     

Treatment of noncustodial fathers: Gender issues and clinical dilemmas

This article addresses issues involved in the treatment of fathers who do not have custody of their children. It reviews literature on demographic trends and discusses fathers' reactions to loss of child custody. Assessment and treatment guidelines are offered so that clinical practice may become more responsive to the needs of the population. Gender concerns, particularly as they relate to transference and countertransference, are also discussed.     

Sources of Influence in the Family Therapy Field: Publication Trends in Three Major Journals1

The institutional sources of all articles published in the three major marriage and family therapy journals through 1978 are identified. The journals reviewed include: Family Process, Journal of Marital and Family Therapy, and the American Journal of Family Therapy. While no single center emerges as dominating the published family therapy literature, a small number of institutions clearly have exerted a profound impact on the literature of the field. Moreover, the absolute number of centers influencing the field is rapidly increasing, and these centers are becoming particularly influential in the newer journals in the field.     

Substance abuse, suicidality, and self-esteem in South African adolescents

Associations among six different domains of self-esteem (peers, school, family, sports/athletics, body image, and global self-worth) and risk behaviors related to substance use and suicidality were investigated in a sample of South African adolescents. Students enrolled in Grades 8 and 11 at independent secondary schools in Cape Town (N = 116) completed the Self-Esteem Questionnaire (SEQ) and a questionnaire that asked about their participation in a range of risk behaviors. Logistic regression analyses indicated that particular domains of self-esteem were differentially associated with indicators of alcohol, cigarette and drug use and suicidal ideation or behaviors in adolescents. Family self-esteem showed the strongest overall pattern of associations with the risk behaviors. Overall, the findings of this study suggest that interventions which aim to protect adolescents from engaging in risk behaviors by increasing their self-esteem are likely to be most effective and cost-efficient if they are aimed at the family and school domains.     

The effect of 6 months training on leg power, balance, and functional mobility of independently living adults over 70 years old

Where strength training has been used in conjunction with functional-task training in older people, not only have there been improvements in leg strength but also improved function has been measured (e.g., Skelton & McLaughlin, 1996). Many studies use participants from care homes rather than community dwellers. We investigated changes in leg power, balance, and functional mobility in community-dwelling sedentary men and women over 70 years of age (n = 6 for training group [TR]; n = 10 for control group [CN]). Progressive training took place over 24 weeks using seated and nonseated exercise. For TR, leg power increased 40%, from 108 +/- 40 to 141 +/- 53 W (p < .01); dynamic balance increased 48%, from 22.3 +/- 7.9 to 33.1 +/- 6.1 cm (p < .01; functional reach); and functional mobility increased 12%, from 7.46 +/- 1.32 to 6.54 +/- 1.41 s (p < .05; timed walk). CN showed no significant change. In conclusion, a community-based exercise program led to large improvements in leg-extensor power, dynamic balance, and functional mobility.