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Alison D. MacEachern Sharon Jackson 《International journal of occupational safety and ergonomics》2013,19(4):329-339
Child protection is an area of police work which has expanded in the last decade, leading to an increase in the number of police officers working in departments which specialise in investigating cases of child abuse. Police officers in this field may be at greater risk of experiencing secondary traumatic stress but there remains a paucity of research in this area of policing. Analogies can be drawn to existing research in policing and with social service workers involved in child protection. The paper finishes off with implications for police forces to ensure safe working environments and appropriate counselling for employees. 相似文献
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Order restricted randomized designs and two sample inference 总被引:1,自引:0,他引:1
This paper develops a new design that relies on subjective judgment ranking to compare subsets of experimental units. This
judgment ranking is used along with restricted randomization to improve statistical inference for the contrast between two
levels of a treatment. The new design assigns the judgment ranked units in a subset to different treatments. Such an assignment
translates the positive dependence among units within each subset into negative dependence for the estimators of treatment
means, and hence leads to a reduction in variance for the contrast. For the proposed design, a test for the difference in
means of two treatment levels is developed along with an associated confidence interval. It is shown that the null distribution
of the proposed test is approximated reasonably well with the Student’s t-distribution for sample sizes as small as 6. A simulation study indicates that the proposed design is advantageous compared
to its competitors in the literature for both high and low quality rankings. The new design’s advantage increases with the
quality of rankings. 相似文献
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Density-dependent habitat selection has numerous and far-reaching implications to population dynamics and evolutionary processes. Although several studies suggest that organisms choose and occupy high-quality habitats over poorer ones, definitive experiments demonstrating active selection, by the same individuals at the appropriate population scale, are lacking. We conducted a reciprocal food supplementation experiment to assess whether voles would first occupy a habitat receiving extra food, then change their preference to track food supplements moved to another habitat. Meadow voles, as predicted, were more abundant in food-supplemented habitat than in others. Density declined when food supplements ceased because the voles moved to the new habitat receiving extra food. Although males and females appeared to follow different strategies, meadow-vole densities reflected habitat quality because voles actively selected the best habitat available. It is thus clear that behavioral decisions on habitat use can motivate patterns of abundance, frequency, and gene flow that have widespread effects on subsequent evolution. 相似文献
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