936 resultados para 802.15.4


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There is a concern that high densities of elephants in southern Africa could lead to the overall reduction of other forms of biodiversity. We present a grid-based model of elephant-savanna dynamics, which differs from previous elephant-vegetation models by accounting for woody plant demographics, tree-grass interactions, stochastic environmental variables (fire and rainfall), and spatial contagion of fire and tree recruitment. The model projects changes in height structure and spatial pattern of trees over periods of centuries. The vegetation component of the model produces long-term tree-grass coexistence, and the emergent fire frequencies match those reported for southern African savannas. Including elephants in the savanna model had the expected effect of reducing woody plant cover, mainly via increased adult tree mortality, although at an elephant density of 1.0 elephant/km2, woody plants still persisted for over a century. We tested three different scenarios in addition to our default assumptions. (1) Reducing mortality of adult trees after elephant use, mimicking a more browsing-tolerant tree species, mitigated the detrimental effect of elephants on the woody population. (2) Coupling germination success (increased seedling recruitment) to elephant browsing further increased tree persistence, and (3) a faster growing woody component allowed some woody plant persistence for at least a century at a density of 3 elephants/km2. Quantitative models of the kind presented here provide a valuable tool for exploring the consequences of management decisions involving the manipulation of elephant population densities. © 2005 by the Ecological Society of America.

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Background Some patients visit a hospital’s emergency department (ED) for reasons other than an urgent medical condition. There is evidence that this practice may differ among patients from different backgrounds. The objective of this study was to examine the reasons why patients from a non-English speaking background (NESB) and patients with an English speaking background but not born in Australia (ESB-NBA) visit the ED, as compared to patients from English-speaking backgrounds but born in Australia (ESB-BA). Methods A cross-sectional survey was conducted at the ED of a tertiary hospital in metropolitan Brisbane, Queensland, Australia. Over a four-month period patients who were assigned an Australasian Triage Scale score of 3, 4 or 5 were surveyed. Pearson chi-square test and multivariate logistic regression analyses were performed to examine the differences between the ESB and NESB patients’ reported reasons for attending the ED. Results A total of 828 patients participated in this study. Compared to ESB-BA patients NESB patients were less likely to consider contacting a general practitioner (GP) before attending the ED (Odds Ratios (OR) 0.6 (95% Confidence Interval (CI) 0.4–0.8, p < .05) While ESB-NBA were more likely to consider contacting a GP 1.7 (1.1–2.5, p < .05). Both the NESB patients and the ESB-NBA patients were far more likely than ESB-BA patients to report that they had visited the ED either because they do not have a GP (OR 7.9, 95% CI 4.7–13.4, p < .001) and 2.2 (95% CI 1.1–4.4, p < .05) respectively and less likely to think that the ED could deal with their problem better than a GP(OR 0.5 (95% CI 0.3–0.8, p < .05) and 0.7 (0.3–0.9, p < .05) respectively. The NESB patients also thought it would take too long to make an appointment to consult a GP (OR 6.2, 95% CI 3.7–10.4, p < 0.001). Conclusions NESB patients were the least likely to consider contacting a GP before attending hospital EDs. Educational interventions may help direct NESB people to the appropriate health services and therefore reduce the burden on tertiary hospitals ED.

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This paper explores how threshold uncertainty affects cooperative behaviors in the provision of public goods and the prevention of public bads. The following facts motivate our study. First, environmental (resource) problems are either framed as public bads prevention or public goods provision. Second, the occurrence of these problems is characterized by thresholds that are interchangeably represented as "nonconvexity," "bifurcation," "bi-stability," or "catastrophes." Third, the threshold location is mostly unknown. We employ a provision point mechanism with threshold uncertainty and analyze the responses of cooperative behaviors to uncertainty and to the framing for each type of social preferences categorized by a value orientation test. We find that aggregate framing effects are negligible, although the response to the frame is the opposite depending on the type of social preferences. "Cooperative" subjects become more cooperative in negative frames than in positive frames, whereas "individualistic" subjects are less cooperative in negative frames than in positive ones. This finding implies that the insignificance of aggregate framing effects arises from behavioral asymmetry. We also find that the percentage of cooperative choices non-monotonically varies with the degree of threshold uncertainty, irrespective of framing and value orientation. Specifically, the degree of cooperation is highest at intermediate levels of threshold uncertainty and decreases as the uncertainty becomes sufficiently large.

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In response to the call for sustainability education in construction courses, higher education institutions have started to incorporate sustainability components into their construction courses to some extent. This research aims to investigate sustainability embedded in construction management (CM) courses using the Queensland University of Technology as a case study. A content analysis of its CM course structure, unit aims, learning objectives and lecture materials is conducted to examine the sustainability elements incorporated into the CM curriculum. The results show that the course incorporates sustainability components into the existing course structure mainly through horizontal integration, embedding sustainability into general units rather than as an add-on subject. Additionally, the sustainability topics embedded in the course cover a comparatively broad and balanced range of sustainability categories, i.e. background knowledge, policies and regulations, environmental issues, social issues and economic issues as well as technology and innovation, although social sustainability aspects need to be further strengthened. This research addresses the need for urgency in the development of an effective sustainability education framework for construction courses. It is expected that the findings from this study will facilitate the improvement of sustainability education in construction courses generally.

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Prevention and management of childhood overweight and obesity is a health priority for governments and communities throughout the developed world. A conceptual model, Research around Practice in Childhood Obesity (RAPICO), has been developed to guide capacity building in a coordinated 'bench to fieldwork' initiative to address this public health problem. Translation of research findings into sustainable responses with optimal fit requires consideration of context-specific relevance, cost-effectiveness, feasibility and levels of available support. The RAPICO model uses program theory to describe a framework for progressing practitionercommunityresearch partnerships to address low, medium and high levels of risk for childhood overweight and obesity within community settings. A case study describing the development of a logic model to inform risk-linked responses to childhood overweight and obesity is presented for the Ipswich community in south-east Queensland.

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A novel interfacial structure consisting of long (up to 5 μm), thin (about 300 nm), highly-ordered, free-standing, highly-reproducible aluminum oxide nanobottles and long tubular nanocapsules attached to a rigid, thin (less than 1 μm) nanoporous anodic alumina membrane is fabricated by simple, fast, catalyst-free, environmentally friendly voltage-pulse anodization. A growth mechanism is proposed based on the formation of straight channels in alumina membrane by anodization, followed by neck formation due to a sophisticated voltage control during the process. This process can be used for the fabrication of alumina nanocontainers with highly controllable geometrical size and volume, vitally important for various applications such as material and energy storage, targeted drug and diagnostic agent delivery, controlled drug and active agent release, gene and biomolecule reservoirs, micro-biologically protected platforms, nano-bioreactors, tissue engineering and hydrogen storage.

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Climate change is one of the most important issues confronting the sustainable supply of seafood, with projections suggesting major effects on wild and farmed fisheries worldwide. While climate change has been a consideration for Australian fisheries and aquaculture management, emphasis in both research and adaptation effort has been at the production end of supply chains—impacts further along the chain have been overlooked to date. A holistic biophysical and socio-economic system view of seafood industries, as represented by end-to-end supply chains, may lead to an additional set of options in the face of climate change, thus maximizing opportunities for improved fishery profitability, while also reducing the potential for maladaptation. In this paper, we explore Australian seafood industry stakeholder perspectives on potential options for adaptation along seafood supply chains based on future potential scenarios. Stakeholders, representing wild capture and aquaculture industries, provided a range of actions targeting different stages of the supply chain. Overall, proposed strategies were predominantly related to the production end of the supply chain, suggesting that greater attention in developing adaptation options is needed at post-production stages. However, there are chain-wide adaptation strategies that can present win–win scenarios, where commercial objectives beyond adaptation can also be addressed alongside direct or indirect impacts of climate. Likewise, certain adaptation strategies in place at one stage of the chain may have varying implications on other stages of the chain. These findings represent an important step in understanding the role of supply chains in effective adaptation of fisheries and aquaculture industries to climate change.

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Children in indigenous populations have substantially higher respiratory morbidity than non-indigenous children. Indigenous children have more frequent respiratory infections that are, more severe and, associated with long-term sequelae. Post-infectious sequelae such as chronic suppurative lung disease and bronchiectasis are especially prevalent among indigenous groups and have lifelong impact on lung function. Also, although estimates of asthma prevalence among indigenous children are similar to non-indigenous groups the morbidity of asthma is higher in indigenous children. To reduce the morbidity of respiratory illness, best-practice medicine is essential in addition to improving socio-economic factors, (eg household crowding), tobacco smoke exposure, and access to health care and illness prevention programs that likely contribute to these issues. Although each indigenous group may have unique health beliefs and interfaces with modern health care, a culturally sensitive and community-based comprehensive care system of preventive and long term care can improve outcomes for all these conditions. This article focuses on common respiratory conditions encountered by indigenous children living in affluent countries where data is available.

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In Australia, the retirement village is regarded as a viable accommodation option for the fast-growing population of older people. Given that diverse stakeholders are involved in the village development process, a comprehensive stakeholder analysis, especially understanding stakeholders' concerns and expectations, is of critical importance to project success. This paper describes a stakeholder analysis based on a typical retirement village. The main methods utilized in this research were case study and an interdisciplinary workshop comprising intensive work sessions and cross-functional review. The participants of this 2014 Brisbane workshop included four village managers from an Australian retirement village developer and eight academics from diverse disciplines from a large university. Through this workshop, 24 village stakeholders and their specific concerns and expectations were identified. Results suggest that both concerns and expectations of these stakeholders are multidimensional and vary considerably, and the concerns and expectations of different stakeholders have complex relationships. Implications for a retirement village development are also proposed. The findings of the study serve as a valuable reference for developers' understanding of stakeholder concerns and expectations, and for taking corresponding actions in the final stages of the retirement village development.

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The hydrodynamic modes and the velocity autocorrelation functions for a dilute sheared inelastic fluid are analyzed using an expansion in the parameter epsilon=(1-e)(1/2), where e is the coefficient of restitution. It is shown that the hydrodynamic modes for a sheared inelastic fluid are very different from those for an elastic fluid in the long-wave limit, since energy is not a conserved variable when the wavelength of perturbations is larger than the ``conduction length.'' In an inelastic fluid under shear, there are three coupled modes, the mass and the momenta in the plane of shear, which have a decay rate proportional to k(2/3) in the limit k -> 0, if the wave vector has a component along the flow direction. When the wave vector is aligned along the gradient-vorticity plane, we find that the scaling of the growth rate is similar to that for an elastic fluid. The Fourier transforms of the velocity autocorrelation functions are calculated for a steady shear flow correct to leading order in an expansion in epsilon. The time dependence of the autocorrelation function in the long-time limit is obtained by estimating the integral of the Fourier transform over wave number space. It is found that the autocorrelation functions for the velocity in the flow and gradient directions decay proportional to t(-5/2) in two dimensions and t(-15/4) in three dimensions. In the vorticity direction, the decay of the autocorrelation function is proportional to t(-3) in two dimensions and t(-7/2) in three dimensions.

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We made a retrospective analysis of the efficacy and complication rate of 268 esophageal dilatation procedures performed under fluoroscopic control using the fiber-optic endoscope in 45 children with esophageal stricture. Antegrade and retrograde stricture dilatation was performed under general anesthetic, mainly as an outpatient procedure. Thirty-six children had an esophageal stricture following tracheoesophageal fistula and/or esophageal atresia repair, and nine children had severe corrosive stricture of the esophagus following lye ingestion. The procedure was well tolerated and effective. © 1992 Raven Press, Ltd., New York.

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This article explains the essence of the context-sensitive parameters and dimensions in play at the time of an intervention, through the application of Rog’s (2012) model of contextual parameters. Rog’s model offers evaluators a structured approach to examine an intervention. The initial study provided a systematic way to clarify the scope, variables, timing, and appropriate evaluation methodology to evaluate the implementation of a government policy. Given that the government implementation of an educational intervention under study did not follow the experimental research approach, nor the double cycle of action research approach, the application of Rog’s model provided an in-depth understanding of the context-sensitive environment; it is from this clear purpose that the broader evaluation was conducted. Overall, when governments or institutions implement policy to invoke educational change (and this intervention is not guided by an appropriate evaluation approach), then program evaluation is achievable post-implementation. In this situation, Rog’s (2012) model of contextual parameters is a useful way to achieve clarity of purpose to guide the program evaluation.

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Swordfish are kept chilled, not frozen, for up to 15 days before being unloaded at Australian ports. Swordfish landed alive, and to a lesser extent prerigor, have better quality when unloaded. Warmer fishing waters did not lead to poorer quality at unloading. There was a serious loss of quality during long fishing trips. Sex had no influence on swordfish quality. Three methods of chilling were evaluated: refrigerated seawater (RSW) chilling for up to 2 days followed by storage under ice, refrigerated brine (seawater with extra salt added) for up to 2 days followed by storage in a freshwater ice slurry, and ice slurry (freshwater ice mixed with seawater) for up to 2 days followed by storage under ice only. Two fishing trips were monitored for each method. The freshness indicator K value was used to determine which method produced the best quality swordfish when unloaded at the factory. Storage method played a larger role in quality loss than capture conditions. Refrigerated brine produced the best quality swordfish when the machinery functioned properly closely followed by RSW. Ice slurry chilling of large fish such as swordfish exhibited initial delays in the reduction of core temperature which led to lower quality. This method could be improved with the addition of mechanical circulation. Mechanical problems, which resulted in minor increases of temperature during brine storage, led to a much larger loss of quality than would be expected.

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Pratylenchus thornei and P. neglectus are two species of root-lesion nematode that cause substantial yield losses in wheat. No commercially available wheat variety has resistance to both species. A doubled-haploid population developed from a cross between the synthetic hexaploid wheat line CPI133872 and the bread wheat Janz was used to locate and tag quantitative trait loci (QTLs) associated with resistance to both P. thornei and P. neglectus. Wheat plants were inoculated with both species of nematode in independent replicated glasshouse trials repeated over 2 years. Known locations of wheat microsatellite markers were used to construct a framework map. After an initial single-marker analysis to detect marker-trait linkages, chromosome regions associated with putative QTLs were targetted with microsatellite markers to increase map density in the chromosome regions of interest. In total, 148 wheat microsatellite markers and 21 amplified fragment length polymorphism markers were mapped. The codominant microsatellite marker Xbarc183 on the distal end of chromosome 6DS was allelic for resistance to both P. thornei and P. neglectus. The QTL were designated QRlnt.lrc-6D.1 and QRlnn.lrc-6D.1, for the 2 traits, respectively. The allele inherited from CPI133872 explained 22.0-24.2% of the phenotypic variation for P. thornei resistance, and the allele inherited from Janz accounted for 11.3-14.0% of the phenotypic variation for P. neglectus resistance. Composite interval mapping identified markers that flank a second major QTL on chromosome 6DL (QRlnt.lrc-6D.2) that explained 8.3-13.4% of the phenotypic variation for P. thornei resistance. An additional major QTL associated with P. neglectus resistance was detected on chromosome 4DS (QRlnn.lrc-4D.1) and explained a further 10.3-15.4% of the phenotypic variation. The identification and tagging of nematode resistance genes with molecular markers will allow appropriate allele combinations to be selected, which will aid the successful breeding of wheat with dual nematode resistance.