988 resultados para Kelly Gulch
Resumo:
To assess the increasing threats to aquatic ecosystems from invasive species, we need to elucidate the mechanisms of impacts of current and predicted future invaders. Dikerogammarus villosus, a Ponto-Caspian amphipod crustacean, is invading throughout Europe and predicted to invade the North American Great Lakes. European field studies show that populations of macroinvertebrates decline after D. villosus invasion. The mechanism of such impacts has not been addressed empirically; however, D. villosus is known to prey upon and replace other amphipods. Therefore, in this study, we used microcosm and mesocosm laboratory experiments, with both single and mixed prey species scenarios, to assess any predatory impact of D. villosus on a range of macro invertebrate taxa, trophic groups, and body sizes. Dikerogammarus villosus predatory behaviour included shredding of prey and infliction of
Resumo:
Invasive species can have profound impacts on communities and it is increasingly recognized that such effects may be mediated by parasitism. The 'enemy release' hypothesis posits that invaders may be successful and have high impacts owing to escape from parasitism. Alternatively, we hypothesize that parasites may increase host feeding rates and hence parasitized invaders may have increased community impacts. Here, we investigate the influence of parasitism on the predatory impact of the invasive freshwater amphipod Gammarus pulex. Up to 70 per cent of individuals are infected with the acanthoce- phalan parasite Echinorhynchus truttae, but parasitized individuals were no different in body condition to those unparasitized. Parasitized individuals consumed significantly more prey (Asellus aquaticus; Isopoda) than did unparasitized individuals. Both parasitized and unparasitized individuals displayed Type-II functional responses (FRs), with the FR for parasitized individuals rising more steeply, with a higher asymptote, compared with unparasi- tized individuals. While the parasite reduced the fitness of individual females, we predict a minor effect on population recruitment because of low parasite prevalence in the peak reproductive period. The parasite thus has a large per capita effect on predatory rate but a low population fitness effect, and thus may enhance rather than reduce the impact of this invader.
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This is one of a series of articles reporting on the large-scale ‘Northern Ireland Care Pathways and Outcomes Study’ (McSherry et al, 2008). The study has been examining a population of young children (n=374) who were in care under five years of age in Northern Ireland, and initially followed them across a four-year period (2000-2004). It has mapped these young children’s care careers, and explored factors relating to five care pathways that these children progressed along, i.e. towards adoption; long-term non-relative foster care; long-term relative foster care; Residence Order; and return to birth parent/s. This paper will examine the children’s care pathway patterns from 2000 to 2004, and will identify the background factors that appear to have influenced their specific care pathway. These background factors relate to the age of child, length of time in care, the child’s health, the child’s behaviour and regional variation. The findings indicate that although the care pathway patterns were to some extent similar to England and Wales, there were differences apparent to the Northern Ireland context.
Resumo:
Christ’s life, as related through the Gospel narratives and early Apocrypha, was subject to a riot of literary-devotional adaptation in the medieval period. This collection provides a series of groundbreaking studies centring on the devotional and cultural significance of Christianity’s pivotal story during the Middle Ages.
The collection represents an important milestone in terms of mapping the meditative modes of piety that characterize a number of Christological traditions, including the Meditationes vitae Christi and the numerous versions it spawned in both Latin and the vernacular. A number of chapters in the volume track how and why meditative piety grew in popularity to become a mode of spiritual activity advised not only to recluses and cenobites as in the writings of Aelred of Rievaulx, but also reached out to diverse lay audiences through the pastoral regimens prescribed by devotional authors such as the Carthusian prior Nicholas Love in England and the Parisian theologian and chancellor of the University of Paris, Jean Gerson.
Through exploring these texts from a variety of perspectives — theoretical, codicological, theological — and through tracing their complex lines of dissemination in ideological and material terms, this collection promises to be invaluable to students and scholars of medieval religious and literary culture.
Resumo:
Evaluating the effectiveness of social work education has become a topic of major interest in the UK in the wake of a succession of child-care tragedies that have undermined confidence in the profession. However, many key aspects of social work education remain under-researched and/or contested and our knowledge of how students acquire and develop professional expertise remains limited. This paper reports on the first part of a longitudinal study aimed at developing evidence-based knowledge in this area by considering student perceptions at different stages of their social work education at Queen’s University Belfast. Focusing on the strengths and limitations of preparatory teaching, and their first experience of practice learning, this article considers the impact of demographic factors, including age, gender and experience, on how students experience the learning process. The findings indicate a significant level of disjunction between academic and practice learning and suggest that better integration between these two domains of learning is needed if social work students are to be more effectively prepared for the challenges they are likely to encounter in practice.