982 resultados para Colonial encounter


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'White syndrome' is considered to be the most prevalent coral disease on the Great Barrier Reef, characterised by rapid rates of lesion progression and high levels of colony mortality. This study investigated the production and translocation of photoassimilates towards white syndrome lesions (WSLs) and artificially inflicted lesions in healthy and diseased colonies of tabular Acropora spp. to determine the intra-colonial response to white syndrome using C-14 labelling. Translocation of C-14 labelled photoassimilates was preferentially orientated away from active WSLs, with minimal C-14 activity observed in the lesion borders, whilst artificial lesions (ALs) created directly opposite WSL borders showed significantly higher C-14 activity, suggesting active translocation of photoassimilates for tissue regeneration. Transport of photoassimilates in healthy coral colonies was preferentially oriented towards ALs with a higher perimeter-area ratio, although translocation towards WSL boundaries was minimal even though the lesion perimeter was often the width of the colony (> 200 cm). We suggest that the preferential orientation of photoassimilates away from WSLs may represent a deliberate strategy by the colony to induce a 'shutdown reaction' in order to preserve intra-colonial resources within areas of the colony that are more likely to survive and recover.

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Over the past 30 years, numerous attempts to understand the relationship between offspring size and fitness have been made, and it has become clear that this critical relationship is strongly affected by environmental heterogeneity. For marine invertebrates, there has been a long-standing interest in the evolution of offspring size, but there have been very few empirical and theoretical examinations of post-metamorphic offspring size effects, and almost none have considered the effect of environmental heterogeneity on the offspring size/fitness relationship. We investigated the post-metamorphic effects of offspring size in the field for the colonial marine invertebrate Botrylloides violaceus. We also examined how the relationship between offspring size and performance was affected by three different types of intraspecific competition. We found strong and persistent effects of offspring size on survival and growth, but these effects depended on the level and type of intraspecific competition.. Generally, competition strengthened the advantages of increasing maternal investment. Interestingly, we found that offspring size determined the outcome of competitive interaction: juveniles that had more maternal investment were more likely to encroach on another juvenile's territory. This suggests that mothers have the previously unrecognized potential to influence the outcome of competitive interactions in benthic marine invertebrates. We created a simple optimality model, which utilized the data generated from our field experiments, and found that increasing intraspecific competition resulted in an increase,in predicted optimal size. Our results suggest that the relationship between offspring size and fitness is highly variable in the marine environment and strongly dependent on the density of conspecifics.

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The medical management of those envenomed by snakes, spiders and poisonous fish in Australia featured extensively in the writings 19th century doctors, expeditioners and anthropologists. Against the background of this introduced medical doctrine there already existed an extensive tradition of Aboriginal medical lore; techniques of heat treatment, suction, incision and the application of plant-derived pharmacological substances featured extensively in the management of envenomed victims. The application of a hair-string or grass-string ligature, suctioning of the bite-site and incision were practised in a variety of combinations. Such evolved independently of and pre-dated such practices, which were promoted extensively by immigrant European doctors in the late 19th century. Pacific scientific toxinology began in the 17th century with Don Diego de Prado y Tovar's 1606 account of ciguatera. By the end of the 19th century more than 30 papers and books had defined the natural history of Australian elapid poisoning. The medical management of snakebite in Australia was the focus of great controversy from 1860 to 1900. Dogmatic claims of the supposed antidote efficacy of intravenous ammonia by Professor G.B. Halford, and that of strychnine by Dr. Augustus Mueller, claimed mainstream medical attention. This era of potential iatrogenic disaster and dogma was brought to a conclusion by the objective experiments of Joseph Lauterer and Thomas Lane Bancroft in 1890 in Brisbane; and by those of C.J. Martin (from 1893) and Frank Tidswell (from 1898), both of Sydney. The modern era of Australian toxinology developed as a direct consequence of Calmette's discovery, in Paris in 1894, of immune serum, which was protective against snakebite. We review the key contributors and discoveries of toxinology in colonial Australia.

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Former colonies and dependencies in the South Pacific do not have the luxury of entirely ‘homegrown’ laws. Their legal systems are burdened with a ‘legacy’ of transplanted laws, developed for use in a foreign country, imposed on pre-existing systems of custom and culture. As a result, many small island countries are struggling to balance the demands of law from different sources, designed to operate in fundamentally different circumstances. In addition to the conflict that occurs in areas of substantive law, where customary and introduced law may prescribe a different rule for the same situation, the two systems differ in their approach to procedure, penalties and relief. This paper considers the divide between the theory and practice of introduced law and customary law and examines the way in which conflicts have been dealt with by the courts. In particular, it uses the example of banishment to illustrate the type of problems that arise in a plural system. The paper looks at the balancing exercise which has been necessary when custom, in the form of banishment, comes into conflict with introduced law, in the form of constitutional rights.

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Movements of wide-ranging top predators can now be studied effectively using satellite and archival telemetry. However, the motivations underlying movements remain difficult to determine because trajectories are seldom related to key biological gradients, such as changing prey distributions. Here, we use a dynamic prey landscape of zooplankton biomass in the north-east Atlantic Ocean to examine active habitat selection in the plankton-feeding basking shark Cetorhinus maximus. The relative success of shark searches across this landscape was examined by comparing prey biomass encountered by sharks with encounters by random-walk simulations of ‘model’ sharks. Movements of transmitter-tagged sharks monitored for 964 days (16754km estimated minimum distance) were concentrated on the European continental shelf in areas characterized by high seasonal productivity and complex prey distributions. We show movements by adult and sub-adult sharks yielded consistently higher prey encounter rates than 90% of random-walk simulations. Behavioural patterns were consistent with basking sharks using search tactics structured across multiple scales to exploit the richest prey areas available in preferred habitats. Simple behavioural rules based on learned responses to previously encountered prey distributions may explain the high performances. This study highlights how dynamic prey landscapes enable active habitat selection in large predators to be investigated from a trophic perspective, an approach that may inform conservation by identifying critical habitat of vulnerable species.

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Post‐colonial theories about liminality, hybridity, unhomeliness, and identity form a novel lens through which to re‐theorise educational development work. Applying these conceptual frameworks allows practitioners and the academics they work with the opportunity to problematise some of educational development’s colonial underpinnings and assumptions. They also enable an exploration of the states of betweenness that form educational developers’ identities and impact implicitly and explicitly upon the nature of their changing practices. This paper seeks to read educational development and research supervisor development in particular “against the grain”. It also seeks to illustrate these concepts through some vignettes of my academic development practice.

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The majority of ‘service’ literature has focused on the production side of service work (i.e. employees and management), while treating the role of the customer and/or consumer as secondary (Korczynski and Ott, 2004). Those authors who have addressed the role consumption plays in shaping and maintaining individuals' self- identity have tended to overemphasize the dominance of consumer culture in shaping ‘our consciousness’ (Ritzer, 1999), with little in the way of empirical evidence to support these assertions. This paper develops the conceptualization of service work and consumer culture literature, by placing more emphasis on the customer in the service encounter. Using an ethnographic study of a ‘high class’ department store, this paper addresses employee and customer identity and the nature of managerial, employee and customer control within this ‘exclusive’ context. Of particular interest is how employees and customer’s ‘embody’ this control. Using Bourdieu’s (1986) conception of class and habitus, the concept of exclusivity goes beyond the management /service worker dyad by providing a means of investigating identity control by the organization over both customers and service workers. However, an organization’s exclusivity is not a closed normative pursuit of control, and shows this enterprise is part of a contested terrain, while revealing the ambiguity and ‘openness’ of control practices and pursuits. In order to uphold the ideal of exclusivity, management, service workers and customers must all engage in a precarious quest for establishing and maintaining a sense of control and/or identity. This paper demonstrates the continuing contradiction between bureaucratic practices of control and consumer culture, and highlights the need for research that investigates the context -dependent nature of control in service-related and consumer studies.