Ecological impacts of invasive alien species along temperature gradients: testing the role of environmental matching

Invasive alien species (IAS) can cause substantive ecological impacts, and the role of temperature in mediating these impacts may become increasingly significant in a changing climate. Habitat conditions and physiological optima offer predictive information for IAS impacts in novel environments. Here, using meta-analysis and laboratory experiments, we tested the hypothesis that the impacts of IAS in the field are inversely correlated with the difference in their ambient and optimal temperatures. A meta-analysis of 29 studies of consumptive impacts of IAS in inland waters revealed that the impacts of fishes and crustaceans are higher at temperatures that more closely match their thermal growth optima. In particular, the maximum impact potential was constrained by increased differences between ambient and optimal temperatures, as indicated by the steeper slope of a quantile regression on the upper 25th percentile of impact data compared to that of a weighted linear regression on all data with measured variances. We complemented this study with an experimental analysis of the functional response - the relationship between predation rate and prey supply - of two invasive predators (freshwater mysid shrimp, Hemimysis anomala and Mysis diluviana) across relevant temperature gradients; both of these species have previously been found to exert strong community-level impacts that are corroborated by their functional responses to different prey items. The functional response experiments showed that maximum feeding rates of H. anomala and M. diluviana have distinct peaks near their respective thermal optima. Although variation in impacts may be caused by numerous abiotic or biotic habitat characteristics, both our analyses point to temperature as a key mediator of IAS impact levels in inland waters and suggest that IAS management should prioritize habitats in the invaded range that more closely match the thermal optima of targeted invaders.

Finding revelation in anthropology: Alexander Winchell, William Robertson Smith and the heretical imperative

Anthropological inquiry has often been considered an agent of intellectual secularization. Not least is this so in the sphere of religion, where anthropological accounts have often been taken to represent the triumph of naturalism. This metanarrative however fails to recognise that naturalistic explanations could sometimes be espoused for religious purposes and in defence of confessional creeds. This essay examines two late nineteenth-century figures – Alexander Winchell in the United States, and William Robertson Smith in Britain – who found in anthropological analysis resources to bolster rather than undermine faith. In both cases these individuals found themselves on the receiving end of ecclesiastical censure and were dismissed from their positions at church-governed institutions. But their motivation was to vindicate divine revelation, in Winchell’s case from the physical anthropology of human origins and in Smith’s from the cultural anthropology of Semitic ritual.

Ecological differences and coexistence in a guild of microparasites: Bartonella in wild rodents

The study of ecological differences among coexisting microparasites has been largely neglected, but it addresses important and unusual issues because there is no clear distinction in such cases between conventional (resource) and apparent competition. Here patterns in the population dynamics are examined for four species of Bartonella (bacterial parasites) coexisting in two wild rodent hosts, bank voles (Clethrionomys glareolus) and wood mice (Apodemus sylvaticus). Using generalized linear modeling and mixed effects models, we examine, for these four species, seasonal patterns and dependencies on host density (both direct and delayed) and, having accounted for these, any differences in prevalence between the two hosts. Whereas previous studies had failed to uncover species differences, here all four were different. Two, B. doshiae and B. taylorii, were more prevalent in wood mice, and one, B. birtlesii, was more prevalent in bank voles. B. birtlesii, B. grahamii, and B. taylorii peaked in prevalence in the fall, whereas B. doshiae peaked in spring. For B. birtlesii in bank voles, density dependence was direct, but for B. taylorii in wood mice density dependence was delayed. B. birtlesii prevalence in wood mice was related to bank vole density. The implications of these differences for species coexistence are discussed.

A ingerência do conhecimento explícito no conhecimento tácito: a técnica Alexander e a prática e ensino da flauta

O presente trabalho é o resultado duma investigação heurística sobre os efeitos do estudo da Técnica Alexander (TA) na prática e no ensino da flauta. Submeti-me a uma centena de aulas de Técnica Alexander e procedi a uma análise reflexiva da minha aprendizagem e prática individual e pedagógica, registando a sua evolução através da progressiva incorporação dos princípios e metodologias daquela técnica. A primeira parte descreve os princípios e procedimentos da TA enquadrando-a na problemática das relações entre conhecimento tácito e explícito, nos processos de controlo motor voluntário e involuntário, e na eficácia e eficiência dos automatismos neuromusculares. A segunda parte constitui a descrição e análise do processo transformador catalisado pelo estudo da TA: modificações na coordenação muscular; na técnica respiratória; no empunhar da flauta e na preparação para a emissão da primeira nota, e na relação entre o equilíbrio do instrumento e o movimento dos dedos. Vários procedimentos e exercícios desenvolvidos para a resolução de problemas pessoais são apresentados justificando a sua eficácia. A TA não proporciona apenas alterações na coordenação muscular mas pode modificar os processos mentais. Por isso alguns princípios para uma organização eficiente da prática são discutidos e concretizados nalguns exercícios que promovem maior variabilidade, alternância entre análise e integração e clareza na concepção do gesto técnico-musical. Por último, a evolução da minha abordagem pedagógica, incorporando procedimentos inspirados na TA e desenvolvidos ao longo da investigação são ilustrados com alguns alunos. A tese argumenta que a TA pode desempenhar um papel fundamental na melhoria do desempenho dum músico e revela-se uma ferramenta pedagógica que merece ser explorada mais sistematicamente num ensino mais baseado numa experimentação guiada que promova uma maior autoconsciência dos processos neuromusculares do que na instrução prescritiva e explícita.

Letter, Greensboro, NC, to George Washington Spencer, Chesterfield, SC, 1890 January 11

This letter is from G. W. Winstead and A. M. Scales to G. W. Spencer regarding Reverend Dr. J. W. Blosser.

A produção social da solidariedade operária : o caso de estudo da Península de Setúbal (1890-1930)

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em História Contemporânea