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281.
Behavioral genomics of honeybee foraging and nest defense   总被引:9,自引:1,他引:8  
The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits. We review what is known about the genetics and physiology of two behavioral traits in honeybees, foraging specialization (pollen versus nectar), and defensive behavior, and present evidence that map-based cloning of genes is more feasible in the bee than in other metazoans. We also present bioinformatic analyses of candidate genes within QTL confidence intervals (CIs). The high recombination rate of the bee made it possible to narrow the search to regions containing only 17–61 predicted peptides for each QTL, although CIs covered large genetic distances. Knowledge of correlated behavioral traits, comparative bioinformatics, and expression assays facilitated evaluation of candidate genes. An overrepresentation of genes involved in ovarian development and insulin-like signaling components within pollen foraging QTL regions suggests that an ancestral reproductive gene network was co-opted during the evolution of foraging specialization. The major QTL influencing defensive/aggressive behavior contains orthologs of genes involved in central nervous system activity and neurogenesis. Candidates at the other two defensive-behavior QTLs include modulators of sensory signaling (Am5HT 7 serotonin receptor, AmArr4 arrestin, and GABA-B-R1 receptor). These studies are the first step in linking natural variation in honeybee social behavior to the identification of underlying genes.  相似文献   
282.
This paper presents new data on the distribution of long-lived radionuclides in Irish Sea subtidal sediments, contaminated as a result of the BNFL Sellafield discharges. The results from different sampling campaigns in 1999 have been combined to assess the extent of radionuclide mobility relative to earlier surveys, in both the eastern and western Irish Sea areas, and to investigate changes in radionuclide distribution over time. The results appear to confirm the trend of continuing re-distribution and transfer of contamination away from the English coast. West of the Isle of Man, radionuclide concentrations and inventories have remained more or less constant. The inventory of radionuclides in sandy sediments in the eastern Irish Sea is still under-represented by current sampling, but could be improved by deeper and more extensive vibrocoring.  相似文献   
283.
Lauren Carruth 《Disasters》2018,42(1):149-168
This paper draws on extended ethnographic and health policy research in eastern Ethiopia to reconsider kinship and nomadism among Somalis, as both of these cultural features transform in the contexts of recurrent humanitarian crises and episodic relief operations. The emergence and importance of new patterns of travel and migration among Somalis in Ethiopia reveal significant changes in the configurations and enactments of Somali kinship, on which many Somalis' mobility depends. Conversely, an analysis of Somalis' dynamic sub‐clan groupings and geographically dispersed kinship networks also highlights emergent patterns of mobility and migration that enable access to training opportunities and employment with relief organisations, as well as to distributions of humanitarian aid. Based on these findings, this paper argues that kinship and nomadism—both long central to Somalis' identities in Ethiopia—remain interdependent, coevolved, and key to their resilience and livelihoods in the face of recurrent crises and intermittent humanitarian responses.  相似文献   
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