969 resultados para Tourism -- Environmental aspects -- North America


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West Nile virus (WNV) is a mosquito-borne flavivirus that is emerging as a global pathogen. In the last decade, virulent strains of the virus have been associated with significant outbreaks of human and animal disease in Europe, the Middle East and North America. Efforts to develop human and veterinary vaccines have taken both traditional and novel approaches. A formalin-inactivated whole virus vaccine has been approved for use in horses. DNA vaccines coding for the structural WNV proteins have also been assessed for veterinary use and have been found to be protective in mice, horses and birds. Live attenuated yellow fever WNV chimeric vaccines have also been successful in animals and are currently undergoing human trials. Additional studies have shown that immunisation with a relatively benign Australian variant of WNV, the Kunjin virus, also provides protective immunity against the virulent North American strain. Levels of efficacy and safety, as well as logistical, economic and environmental issues, must all be carefully considered before vaccine candidates are approved and selected for large-scale manufacture and distribution.

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Studies of plant and animal assemblages from both the terrestrial and the marine fossil records reveal persistence for extensive periods of geological time, sometimes millions of years. Persistence does not require lack of change or the absence of variation from one occurrence of the assemblage to the next in geological time. It does, however, imply that assemblage composition is bounded and that variation occurs within those bounds. The principal cause for these patterns appears to be species-, and perhaps clade-level, environmental fidelity that results in long-term tracking of physical conditions. Other factors that influence persistent recurrence of assemblages are historical, biogeographic effects, the law of large numbers, niche differentiation, and biotic interactions. Much research needs to be done in this area, and greater uniformity is needed in the approaches to studying the problem. However, great potential also exists for enhanced interaction between paleoecology and neoecology in understanding spatiotemporal complexity of ecological dynamics.

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A new species of Gyracanthides from the mid-Visean Ducabrook Formation of Middle Paddock site, near Springsure in the Drummond Basin, central Queensland, is based on isolated three-dimensionally preserved elements. The specimens comprise paired and unpaired spines and pectoral girdle elements, procoracoids and scapulocoracoids, and include growth series. The morphology, especially of the shoulder girdle bones and the form and tubercular ornamentation of the paired fin spines, is used to distinguish the new taxon. These characters also help differentiate the numerous described gyracanthid species. Aspects of palaeobiology including possible sexual dimorphism are explored. A hypothetical reconstruction of the fish is based on our interpretation of the articulation of isolated elements combined with examination of wear patterns on fin spines. Gyracanthides hawkinsi sp. nov. is compared with other Australian taxa as well as with gyracanthids from North America, Europe, Russia, Iran, Africa and Antarctica, some of which are tentatively reassigned here to the Gondwanan genus Gyracanthides.

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By combining economic analysis of markets with ecological parameters, this article considers the role that tourism-based sea turtle hatcheries (of an open-cycle type) can play in conserving populations of sea turtles. Background is provided on the nature and development of such hatcheries in Sri Lanka. The modeling facilitates the assessment of the impacts of turtle hatcheries on the conservation of sea turtles and enables the economic and ecological consequences of tourism, based on such hatcheries, to be better appreciated. The results demonstrate that sea turtle hatcheries serving tourists can make a positive contribution to sea turtle conservation, but that their conservation effectiveness depends on the way they are managed. Possible negative effects are also identified. Economic market models are combined with turtle population survival relationships to predict the conservation impact of turtle hatcheries and their consequence for the total economic value obtained from sea turtle populations.

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Since the Second World War, Australian governments have adopted various approaches to governing nonmetropolitan Australia. The authors profile three distinct approaches to governance characterised as (1) state-centred regionalism; (2) new localism; and (3) new forms of multifaceted regionalism. Although recent policy initiatives have been justified by the argument that the region is the most suitable scale for planning and development in nonmetropolitan Australia, in practice the institutional landscape is a hybrid of overlapping local, regional, and national scales of action. The authors compare this new, multifaceted, regionalism with the so-called 'new regionalism currently being promoted in Western Europe and North America. It is argued that new regionalism differs in quite important ways from the regionalism currently being fostered in Australia. In Australia, the centrality of sustainability principles, and the attempt to foster interdependence amongst stakeholders from the state, market, and civil society, have produced a layer of networked governance that is different from that overseas. It is argued that there is a triple bottom-line 'promise' in the Australian approach which differs from the Western Europe/North American model, and which has the potential to deliver enhanced economic, social, and environmental outcomes.

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Environmental conditions influence the breeding and migratory patterns of many avian species and may have particularly dramatic effects on long-distance migrants that breed at northern latitudes. Environment, however, is only one of the ecological variables affecting avian phenology, and recent work shows that migration tactics may be strongly affected by changes in predator populations. We used long-term data from 1978 to 2000 to examine the interactions between snowmelt in western Alaska in relation to the breeding or migration phenologies of small shorebirds and their raptor predators. Although the sandpipers' time of arrival at Alaskan breeding sites corresponded with mean snowmelt, late snowmelts did delay breeding. These delays, however, did not persist to southward migration through British Columbia, likely due to the birds' ability to compensate for variance in the length of the breeding season. Raptor phenology at an early stopover site in British Columbia was strongly related to snowmelt, so that in years of early snowmelt falcons appeared earlier during the sandpipers' southbound migration. These differential effects indicate that earlier snowmelt due to climate change may alter the ecological dynamics of the predator-prey system.

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A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. This considers all aspects of the special characteristics of bio-oil – how they are created and the solutions available to help meet requirements for utilisation. Particular attention is paid to chemical and catalytic upgrading including synthesis gas and hydrogen production which has seen a wide range of new research activities and also more limited attention to chemicals recovery. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material.

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This research identifies factors which influence the consumption of potable water supplied to customers' property. A complete spectrum of the customer base is examined including household, commercial and industrial properties. The research considers information from around the world, particularly demand management and tariff related projects from North America. A device termed the Flow Moderator was developed and proven, with extensive trials, to conserve water at a rate equivalent to 40 litres/property/day whilst maintaining standards-of-service considerably in excess of Regulatory requirements. A detailed appraisal of the Moderator underlines the costs and benefits available to the industry through deliberate application of even mild demand management. More radically the concept of a charging policy utilising the Moderator is developed and appraised. Advantages include the lower costs of conventional fixed-price charging systems coupled with the conservation and equitability aspects associated with metering. Explanatory models were developed linking consumption to a range of variables demonstrated that households served by a communal water service-pipe (known in the UK as a shared supply) are subject to associated restrictions equivalent to -180 litres/property/day. The research confirmed that occupancy levels were a significant predictive element for household, commercial and industrial customers. The occurrence of on-property leakage was also demonstrated to be a significant factor recorded as an event which offers considerable scope for demand management in its own right.

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A comprehensive examination is made of the characteristics and quality requirements of bio-oil from fast pyrolysis of biomass. An appreciation of the potential for bio-oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe, and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio-oil raw material. © 2012 American Institute of Chemical Engineers (AIChE).

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Biomass burning results in the formation and accumulation of pyrogenic products such as black carbon (BC) and black nitrogen (BN) in soils. The ubiquitous presence of pyrogenic products in natural dissolved organic matter (DOM) and potential implications in global carbon cycling have recently been reported. However, little is known about the environmental dynamics or the importance in the global N cycle of dissolved BN (DBN; or heteroaromatic N). Here we report the coupling between DBN and dissolved BC (DBC) in ultrafiltered DOM from six headwater streams across a climatic region of North America, suggesting similar combustion sources, and that DOC may play an important role in the translocation of soil BN to the dissolved phase. The export of potentially recalcitrant riverine DBN to the ocean may affect the biogeochemical cycling of N and possibly the microbial community structure in aquatic environments.

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Artisanal fishing is one of the important economic activities of Rio Grande do Norte (RN), becoming the main form of survival and income for many families. The southern coast of RN has strong fishing tradition, both in exploitation of fish as in the collection of mollusks on the banks of Guaraíra Lagoon (APA Bonfim-Guaraíra). In recent years, fishing communities have become more vulnerable to outside influences, since the socio-economic and environmental changes are exposed. These changes require adjustments to the fishermen to different environmental conditions, as the social and natural systems are driven by reorganization and upgrading processes. The living conditions in fishing communities are objective and necessary in different ways, according to a selection that is cultural, so adaptable. This study has the general objective to analyze the main environmental changes in fishing communities, based on the understanding of fishermen and mollusk fisherwomen about this problem. The specific objectives searched to: describe the socioeconomic profile, prospects and difficulties of fishermen and mollusk fisherwomen; investigate the major social and environmental changes in the fishing communities of Patané and Camocim (Arez/RN). The methodology was qualitative-quantitative with the techniques of observation in the field and open and semistructured interviews applied to representatives of Cologne fishing, fishermen and mollusk fisherwomen. Between the months of January to July 2014 were applied semistructured interviews with 41 interlocutors in Patané and 23 of Camocim; totaling 64 people. The results indicated that the interlocutors are aged 40 to 60 years; have only completed elementary school level; are married and have children; survive on less than a minimum wage income and they are not receiving employment insurance. The case study also revealed that the socioeconomic and environmental problems reflected in changes in reproduction, organization and social division of labor, which generates adaptive changes of families to external influences, resulting directly from other economic activities and market pressure and indirectly from tourism. Therefore, adaptations to changes scenario presented as favorable to economic aspects and unfavorable to the social and environmental aspects. In short, the fishery develops on technical, bureaucratic and financial obstacles, in the everyday needs of men and women is the determining factor in willingness to continue exercising fishing and shell fishing on Guaraíra Lagoon, space representing relations social, practices and customs transmitted in the course of local history through social memory of the oldest to the youngest.