15 research outputs found
Bayesian inference supports the host selection hypothesis in explaining adaptive host specificity by European bitterling
Generalist parasites have the capacity to infect multiple hosts. The temporal pattern of host specificity by generalist parasites is rarely studied, but is critical to understanding what variables underpin infection and thereby the impact of parasites on host species and the way they impose selection on hosts. Here, the temporal dynamics of infection of four species of freshwater mussel by European bitterling fish (Rhodeus amarus) was investigated over three spawning seasons. Bitterling lay their eggs in the gills of freshwater mussels, which suffer reduced growth, oxygen stress, gill damage and elevated mortality as a result of parasitism. The temporal pattern of infection of mussels by European bitterling in multiple populations was examined. Using a Bernoulli Generalized Additive Mixed Model with Bayesian inference it was demonstrated that one mussel species, Unio pictorum, was exploited over the entire bitterling spawning season. As the season progressed, bitterling showed a preference for other mussel species, which were inferior hosts. Temporal changes in host use reflected elevated density-dependent mortality in preferred hosts that were already infected. Plasticity in host specificity by bitterling conformed with the predictions of the host selection hypothesis. The relationship between bitterling and their host mussels differs qualitatively from that of avian brood parasites
Heteronormative citizenship and the politics of passing
Copyright © 2002 SAGE PublicationsThis article argues that, despite more ostensibly âoutâ politicians and better anti-discrimination measures, strange forms of âpassingâ are still taking place in public life. Heterosexual constructions of citzenship are still being privileged. The analysis uses British, Australian and US examples to draw out the implications of these forms of âpassingâ for issues of citizen identity, policy and public behaviour. The article concludes by suggesting that existing queer theory has not engaged adequately with key issues influencing the construction of heteronormative citizenship.Carol Johnso
Male coloration signals direct benefits in the European bitterling (Rhodeus amarus)
Female mating preferences are frequently associated with exaggerated male sexual traits. In the European bitterling, Rhodeus amarus, a fish with a resource-based mating system, male coloration is not associated with indirect genetic benefits of female mate choice, and does not reliably signal spawning site quality. We tested a link between the extent of male carotenoid-based coloration and testis size and number of spermatozoa stripped from the testes. Male body size predicted spermatozoa number, but less reliably than the extent of male coloration. Male color was a highly significant predictor of spermatozoa number, with approximately 26 % of variance in the number of spermatozoa stripped from males predicted from male color after controlling for male body size. Body size, but not coloration, predicted teste size. Female bitterling often risk sperm limitation, especially during pair spawnings, and male nuptial coloration may be under direct selection through female mate choice as a signal of male fertilization efficiency
Everyday terrorism: connecting domestic violence and global terrorism
This paper remaps the geographies of terrorism. Everyday terrorism (domestic violence) and global terrorism are related attempts to exert political control through fear. Geographical research on violence neatly reflects the disproportionate recognition and resourcing that global terrorism receives from the state. The paper explores the parallels, shared foundations and direct points of connection between everyday and global terrorisms. It does so across four interrelated themes: multiscalar politics and securities, fear and trauma, public recognition and recovery, and the inequitable nature of counter-terrorisms. It concludes with implications for addressing terrorisms and for future research