718 resultados para Weak sustainability


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We study the spectral and noise properties of the fluorescence field emitted from a two-level atom driven by a beam of squeezed light. For a weak driving field we derive simple analytical formulae for the fluorescence and quadrature-noise spectra which are valid for an arbitrary bandwidth of the squeezed field. We analyse the spectra in the regime where the squeezing bandwidth is smaller or comparable to the atomic linewidth, the area where non-Markovian effects are important. We emphasize that there is a noticable difference between the fluorescence spectra for the thermal and squeezed field excitations. In both cases the spectrum can be narrower than any bandwidth involved in the process. However, as we point out for the squeezed driving field the linewidth narrowing, being much larger than in the thermal-field case, can be attributed to the squeezing of the fluctuations in the driving held. We also calculate the quadrature-noise spectrum of the emitted fluorescence, and find that for a detuned squeezed field the fluorescence spectrum does not reveal the quadrature-noise spectrum. In contrast to the fluorescence spectrum having two peaks, the quadrature-noise spectrum exhibits three peaks. We explain this difference as arising from the competiting three-photon scattering processes. (C) 1998 Elsevier Science B.V. All rights reserved.

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Community awareness of the sustainable use of land, water and vegetation resources is increasing. The sustainable use of these resources is pivotal to sustainable farming systems. However, techniques for monitoring the sustainable management of these resources are poorly understood and untested. We propose a framework to benchmark and monitor resources in the grains industry. Eight steps are listed below to achieve these objectives: (i) define industry issues; (ii) identify the issues through growers, stakeholder and community consultation; (iii) identify indicators (measurable attributes, properties or characteristics) of sustainability through consultation with growers, stakeholders, experts and community members, relating to: crop productivity; resource maintenance/enhancement; biodiversity; economic viability; community viability; and institutional structure; (iv) develop and use selection criteria to select indicators that consider: responsiveness to change; ease of capture; community acceptance and involvement; interpretation; measurement error; stability, frequency and cost of measurement; spatial scale issues; and mapping capability in space and through time. The appropriateness of indicators can be evaluated using a decision making system such as a multiobjective decision support system (MO-DSS, a method to assist in decision making from multiple and conflicting objectives); (v) involve stakeholders and the community in the definition of goals and setting benchmarking and monitoring targets for sustainable farming; (vi) take preventive and corrective/remedial action; (vii) evaluate effectiveness of actions taken; and (viii) revise indicators as part of a continual improvement principle designed to achieve best management practice for sustainable farming systems. The major recommendations are to: (i) implement the framework for resources (land, water and vegetation, economic, community and institution) benchmarking and monitoring, and integrate this process with current activities so that awareness, implementation and evolution of sustainable resource management practices become normal practice in the grains industry; (ii) empower the grains industry to take the lead by using relevant sustainability indicators to benchmark and monitor resources; (iii) adopt a collaborative approach by involving various industry, community, catchment management and government agency groups to minimise implementation time. Monitoring programs such as Waterwatch, Soilcheck, Grasscheck and Topcrop should be utilised; (iv) encourage the adoption of a decision making system by growers and industry representatives as a participatory decision and evaluation process. Widespread use of sustainability indicators would assist in validating and refining these indicators and evaluating sustainable farming systems. The indicators could also assist in evaluating best management practices for the grains industry.

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We investigate the utility of nonclassical states of simple harmonic oscillators, particularly a superposition of coherent states, for sensitive force detection. We find that like squeezed states, a superposition of coherent states allows displacement measurements at the Heisenberg limit. Entangling many superpositions of coherent states offers a significant advantage over a single-mode superposition state with the same mean photon number.

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The incentives and governance system of organizations are important in explaining how they behave in localized development processes. This article builds on the observation that the literature on territorial development does not generally address the action of social movements. At the same time, research on social movements rarely studies their effects on the territories ill which they act. This text is a contribution to fill this gap. It compares two social movement organizations: a trade union federation and a credit cooperative system operating throughout southern Brazil, Both organizations share common origins and social bases, yet their impacts oil territories have been quite different. The analysis focuses Oil the social ties that link trade unions and cooperatives to their territories to show that governance systems may explain the performance of each organization, especially with regard to their capacity for innovation. (c) 2008 Elsevier Ltd. All rights reserved.

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Multi-strategy interventions have been demonstrated to prevent falls among older people, but studies have not explored their sustainability. This paper investigates program sustainability of Stay on Your Feet (SOYF), an Australian multi-strategy falls prevention program (1992-1996) that achieved a significant reduction in falls-related hospital admissions. A series of surveys assessed recall, involvement and current falls prevention activities, 5 years post-SOYF in multiple original SOYF stakeholder groups within the study area [general practitioners (GPs), pharmacists, community health (CH) staff shire councils (SCs) and access committees (ACs)]. Focus groups explored possible behavioural changes in the target group. Surveys were mailed, except to CH staff and ACs. who participated in guided group sessions and were contacted via the telephone, respectively. Response rates were: GPs. 67% (139/209); pharmacists, 79% (53/67); CH staff, 63% (129/204); SCs, 90% (9/10); ACs, 80% (8/10). There were 73 older people in eight focus groups. Of 117 GPs who were practising during SOYF 80% recalled SOYF and 74% of these reported an influence on their practice. Of 46 pharmacists operating a business during SOYF, 45% had heard of SOYF and 79% of these reported being 'somewhat' influenced. Of 76 community health staff (59%) in the area at that time, 99% had heard of SOYF and 82% reported involvement. Four SCs retained a SOYF resource, but none thought current activities were related. Seven ACs reported involvement, but no activities were sustained. Thirty-five focus group participants (48%) remembered SOYF and reported a variety of SOYF-initiated behaviour changes. Program sustainability was clearly demonstrated among health practitioners. Further research is required to assess long-term effect sustainability.

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The Strength of Weak Parties The aim of this article is to fill some gaps in research on the Brazilian electoral arena. The current literature, by neglecting the study of party organization, ends up overlooking fundamental questions for understanding how the electoral process works. This study addressed two questions: How do Brazilian parties work? What is the impact of party organization on a party`s decision to launch or withhold a candidate in a given election? We intend to show that the parties have more life than many studies on our political system tend to show. This partisan life helps understand one of the central aspects of the electoral arena, that is, how pre-election coordination occurs.

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This study shows the creation of a graphical representation after the application of a questionnaire to evaluate the indicative factors of a sustainable telemedicine and telehealth center in Sao Paulo, Brazil. We categorized the factors into seven domain areas: institutional, functional, economic-financial, renewal, academic-scientific, partnerships, and social welfare, which were plotted into a graphical representation. The developed graph was shown to be useful when used in the same institution over a long period and complemented with secondary information from publications, archives, and administrative documents to support the numerical indicators. Its use may contribute toward monitoring the factors that define telemedicine and telehealth center sustainability. When systematically applied, it may also be useful for identifying the specific characteristics of the telemedicine and telehealth center, to support its organizational development.

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