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Climate change may affect the frequency, intensity, and geographic distribution of severe coastal storms. Concurrent sea-level rise would raise the baseline of flooding during such events. Meanwhile, social vulnerability factors such as poverty and disability hinder the ability to cope with storms and storm damage. While physical changes are likely to remain scientifically uncertain into the foreseeable future, the ability to mitigate potential impacts from coastal flooding may be fostered by better understanding the interplay of social and physical factors that produce human vulnerability. This study does so by integrating the classic causal model of hazards with social, environmental, and spatial dynamics that lead to the differential ability of people to cope with hazards. It uses Census data, factor analysis, data envelopment analysis, and floodplain maps to understand the compound social and physical vulnerability of coastal residents in the city of Revere, MA, USA. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
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The essence of eusociality is a trade-off between producing ones own offspring and helping collateral kin via such activities as defence, foraging and brood rearing. This trade-off often involves morphological differences between helper and reproductive castes, but the advantages, correlates and phylogenetic context of morphological caste differentiation have seldom been analysed. Six species of Australian gall-inducing thrips on Acacia show morphological polymorphism. One morph, referred to as a soldier, has reduced wings and antennae but greatly enlarged fore-femora, which are thought to be adaptations for gall defence. The other, dispersing morph, has fully developed wings and relatively slight fore-femora. Here, we quantify the defensive behaviour of soldier morphs, and compare soldier and foundresses, using behavioural assays designed to measure proclivity to attack kleptoparasites (specialised invaders in the genus Koptothrips) and effectiveness in killing them. In all five species investigated, soldiers were able to kill Koptothrips. Moreover, the effectiveness of soldiers was relatively high in the more-derived species in the phylogeny of the clade, Kladothrips intermedius, K. habrus and K. waterhousei. Soldiers of K. intermedius and K. habrus also killed kleptoparasites more effectively than did foundresses, and K. habrus soldiers exhibited higher proclivity to attack than did foundresses. Data from naturally invaded galls demonstrate that soldiers in the field do kill Koptothrips, and vice versa. These results show that soldiers of Australian gall thrips are motivated and effective for gall defence.Communicated by D. Gwynne  相似文献   
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Visual cues are important navigational tools for many solitary foraging insects. In addition to information provided by path integration, desert ants learn and use visual cues for homing back to their nest. In this study, we compared the visually based learning of two desert ant species: the North African Cataglyphis fortis and the Australian Melophorus bagoti, each of which lives in ecologically similar but visually different environments. In our experiment, ants’ choice performance was measured by training foragers in a channel system. We used a decision box with two visual stimuli during their homebound trips, with one of the stimuli always being the correct one that provided thoroughfare. To determine any habitat effects on learning, we examined intraspecific comparisons in C. fortis with different nest surroundings. The intraspecific comparison in C. fortis revealed no differences in learning the task. In general, C. fortis showed little learning in our task and the results were similar for ants from barren and cluttered environments. Overall, M. bagoti learned the task faster and had a higher level of accuracy than C. fortis. One explanation for this species-specific difference could be that the cluttered habitat of M. bagoti favours the evolution of visual associative learning more so than the plain habitat of C. fortis.  相似文献   
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