Populations in fragmented habitat patches may show ecological differentiation, which has implications for metapopulation viability. In this study we used a common garden with two watering treatments to contrast mean differences in ecophysiological traits and the relationships between traits and performance among seven populations of three alvar species. These species differ in their alvar specialization in Ontario, from almost endemic (Solidago ptarmicoides) to highly confined (Dasiphora fruticosa) to a widespread generalist (Hypericum perforatum). Populations of all species exhibited mean differences in at least one trait: photosynthesis (Amax), growth rate and specific leaf area. More surprisingly, the relationship between functional traits and performance was significantly different among populations in all species, suggesting different strategies for maximizing growth in different environments. The ecological differentiation observed affected all species regardless of distribution and is likely genetically based. This differentiation may destabilize metapopulation dynamics and reduce rates of spread if colonization is negatively impacted.

Populations in fragmented habitat patches may show ecological differentiation, which has implications for metapopulation viability. In this study we used a common garden with two watering treatments to contrast mean differences in ecophysiological traits and the relationships between traits and performance among seven populations of three alvar species. These species differ in their alvar specialization in Ontario, from almost endemic (Solidago ptarmicoides) to highly confined (Dasiphora fruticosa) to a widespread generalist (Hypericum perforatum). Populations of all species exhibited mean differences in at least one trait: photosynthesis (Amax), growth rate and specific leaf area. More surprisingly, the relationship between functional traits and performance was significantly different among populations in all species, suggesting different strategies for maximizing growth in different environments. The ecological differentiation observed affected all species regardless of distribution and is likely genetically based. This differentiation may destabilize metapopulation dynamics and reduce rates of spread if colonization is negatively impacted.

No description available.

A significant goal in studies on learning and memory is to relate cellular plasticity to the modification of behaviour. The phenomenon of dual-process learning affords an ideal opportunity to explore the complexities inherent in establishing this relationship. Dual-process learning occurs when depression (habituation) and facilitation (sensitization) are expressed simultaneously within a neural network and compete to determine the behavioural outcome. A large body of literature is reviewed to define characteristics which are common across the neural networks that exhibit dual-process learning: depression occurs at loci early in the reflex pathway, upstream of the modulatory system necessary for the induction of facilitation. Consequently, depression not only competes directly with facilitation for the determination, of behavioural change (by serial and/or parallel expression), but depression also precludes the ongoing development and maintenance of sensitization (by serial induction). A mathematical model is presented to formally describe the nature of this competition and how this competition leads to the kinetics of dual-process learning. The tentacle withdrawal reflex of the snag Helix aspersa exhibits dual-process learning and was further investigated in this study. The neural circuit mediating tentacle withdrawal is described along with the nature and the location of plasticity which occurs within that circuit. In turn, plasticity at the cellular level is related, via the network level, to plasticity at the behavioural level. The data demonstrate the importance of localizing the sites of plasticity within a neural network in order to explain (1) how plasticity at a particular locus influences plasticity occurring elsewhere in the network and (2) how plasticity at different loci affect different aspects of behaviour.

The gonad of the snail Helix aspersa is innervated by a branch of the intestinal nerve. Here it is demonstrated that nerve stimulation causes peristaltic contractions and the acceleration of cilia beating in the proximal part of the hermaphroditic duct. Acetylcholine and serotonin induced peristaltic contractions when applied without nerve stimulation. As well, serotonin induced the acceleration of cilia beating. The neuropeptide FMRFamide caused dilation of the hermaphroditic duct. Pharmacological blocking of acetylcholine and serotonin receptors with concurrent nerve stimulation induced a dilation similar to that caused by FMRFamide application. It is suggested that all three transmitters are released from intestinal nerve terminals to facilitate oocyte transport during ovulation. Nerve stimulation induced an increase in gamete transport rates. Because several candidate chemical messengers failed to induce ovulation when injected into the circulatory system, Helix aspersa appears to initiate ovulation differently from related species. Whereas Aplysia and Lymnaea use hormones, Helix apparently signals ovulation via the intestinal nerve.

No description available.

No description available.

Ordinary life oscillates between dichotomies: from work to leisure, from reality to fantasy, from private to public. These are distinct worlds that bring order to the chaos of experience; their boundaries contain what philosopher James Carse calls finite games. As we move from game to game, we find ourselves in perpetual motion. SUPER ORDINARY explores Carse‚s other type of game: the infinite game. It is an architectural investigation of its potential to transcend the serious and experience the truly playful, an attempt to manifest a place without boundaries in a world defined by them. Lamport Stadium is the setting for this journey. In this theatre of finite games, our experiences are limited to its rules and boundaries. However, where we truly play, we liberate personal narratives from finite games. Architecture, rather than categorizing experience, is instead redefined through experience. Ergo, rather than the site of finite games, SUPER ORDINARY imagines Lamport Stadium as an infinite game. The dichotomies of finite play˜field and bleacher, player and observer, inside and out, and so on˜are dissolved, and the stadium becomes a place of possibility and adventure; here, we can at once submit to the ecstasy of the place while forging our own narratives. It is a building that is never quite finished, but always open to our imaginations.

The Western Australian Museum houses a large collection of artefacts from late nineteenth century iron sailing vessels, wrecked en route from Britain. The bulk of this collection comprises cargo objects, destined for sale in the Swan River colony. The protection afforded artefacts, due to the integrity of these shipwrecks, presents new research opportunites for identifying particular classes of commodities which were considered either necessary or desirable for colonial consumers. This thesis examines the notion of material consumption as reflected in shipwreck assemblages in Western Australia for the later nineteenth century, prior to Federation. The research is concerned with the notion of cultural continuity from Britain through specific product selection, as demonstrated by the archaeological assemblages of iron barques importing general merchandise into the colony. Focusing on the Sepia (1898), the objectives include an appraisal of shipwreck cargo artefacts and their applicability to questions relating to consumer behaviour. While the primary objective of this study is on the identification of cargo assemblages, it presents an opportunity to study taphonomic processes and provide a method of relating the vessel to its cargo contents in order to answer broader questions about shipping practices, with a particular focus on stowage. This research also critiques shipwreck collections comprised of selectively recovered, unprovenanced artefacts and suggests appropriate methods for using such material.

Thesis (M.Env.Sc.)--University of Adelaide, School of Social Sciences, Discipline of Geographical and Environmental Studies, 2003. / "June 2003" Bibliography: leaves 81-88.