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181.
In pest risk assessment it is frequently necessary to make management decisions regarding emerging threats under severe uncertainty. Although risk maps provide useful decision support for invasive alien species, they rarely address knowledge gaps associated with the underlying risk model or how they may change the risk estimates. Failure to recognize uncertainty leads to risk‐ignorant decisions and miscalculation of expected impacts as well as the costs required to minimize these impacts. Here we use the information gap concept to evaluate the robustness of risk maps to uncertainties in key assumptions about an invading organism. We generate risk maps with a spatial model of invasion that simulates potential entries of an invasive pest via international marine shipments, their spread through a landscape, and establishment on a susceptible host. In particular, we focus on the question of how much uncertainty in risk model assumptions can be tolerated before the risk map loses its value. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. The results provide a spatial representation of the robustness of predictions of S. noctilio invasion risk to uncertainty and show major geographic hotspots where the consideration of uncertainty in model parameters may change management decisions about a new invasive pest. We then illustrate how the dependency between the extent of uncertainties and the degree of robustness of a risk map can be used to select a surveillance network design that is most robust to knowledge gaps about the pest.  相似文献   
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This paper offers a rationale for the comprehensive inclusion of women's issues in social work education. The development of women's studies is traced, with particular reference to a current social work programme at the University of New South Wales. It is asserted that women's studies has something distinctive to offer the social work curriculum.  相似文献   
184.
Consider classifying an n × I observation vector as coming from one of two multivariate normal distributions which differ both in mean vectors and covariance matrices. A class of dis-crimination rules based upon n independent univariate discrim-inate functions is developed yielding exact misclassification probabilities when the population parameters are known. An efficient search of this class to select the procedure with minimum expected misclassification is made by employing an algorithm of the implicit enumeration type used in integer programming. The procedure is applied to the classification of male twins as either monozygotic or dizygotic.  相似文献   
185.
Routine implementation of the Bayesian paradigm requires an efficient approach to the calculation and display of posterior or predictive distributions for given likelihood and prior specifi- cations. In this paper we shall review some of the analytic and numerical approaches currently available, describing in detail a numerical integration strategy based on Gaussian quadrature, and an associated strategy for the reconstruction and display of distributions based on spline techniques.  相似文献   
186.
One of the most notorious network design problems is the Quadratic Assignment Problem (QAP). We develop an heuristic algorithm for QAPs along with an M/G/C/C state dependent queueing model for capturing congestion in the traffic system interconnecting the nodes in the network. Computational results are also presented.  相似文献   
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A hazard model of the probability of medical school drop-out in the UK   总被引:2,自引:0,他引:2  
Summary.  From individual level longitudinal data for two entire cohorts of medical students in UK universities, we use multilevel models to analyse the probability that an individual student will drop out of medical school. We find that academic preparedness—both in terms of previous subjects studied and levels of attainment therein—is the major influence on withdrawal by medical students. Additionally, males and more mature students are more likely to withdraw than females or younger students respectively. We find evidence that the factors influencing the decision to transfer course differ from those affecting the decision to drop out for other reasons.  相似文献   
189.
As societies like Northern Ireland, Israel, and South Africa strive to resolve social conflict, there is growing theoretical and empirical interest in the role of intergroup forgiveness. This study examined intergroup forgiveness among 340 young adults in Northern Ireland. A short form of the Enright Forgiveness Inventory explored possible influences on propensity to forgive. All participants were Catholic and female (mean age 17.36 years), and had experienced verbal or physical injury or bereavement due to the Northern Irish political violence. Overall forgiveness levels were low in comparison with previous studies of interpersonal forgiveness but similar to previous studies of intergroup forgiveness in Northern Ireland. The strongest (negative) predictor of forgiveness was the perceived degree of hurt caused by the injury .  相似文献   
190.
Facial expression in the presence of friends and strangers   总被引:1,自引:0,他引:1  
This study investigated the effect of the physical presence of a friend or of a stranger on facial expressiveness. Pairs of friends and pairs of strangers (all women) were unobtrusively videotaped while they viewed together a number of emotional stimulus slides, and rated their individual emotional responses to them. Judges subsequently attempted to identify from the videotapes the emotions reported by each sender subject. Generally, expressions were more readily identified for women videotaped with friends than for those recorded with strangers. These results support the suggestion that the degree to which emotions are expressed depends on the role of an accompanying person. Altemative interpretations of this view are discussed.We thank Alan Fridlund and an anonymous reviewer for comments on a previous version of this paper.  相似文献   
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