929 resultados para Management Sciences.
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A fundamental shift to a total system approach for crop protection is urgently needed to resolve escalating economic and environmental consequences of combating agricultural pests. Pest management strategies have long been dominated by quests for “silver bullet” products to control pest outbreaks. However, managing undesired variables in ecosystems is similar to that for other systems, including the human body and social orders. Experience in these fields substantiates the fact that therapeutic interventions into any system are effective only for short term relief because these externalities are soon “neutralized” by countermoves within the system. Long term resolutions can be achieved only by restructuring and managing these systems in ways that maximize the array of “built-in” preventive strengths, with therapeutic tactics serving strictly as backups to these natural regulators. To date, we have failed to incorporate this basic principle into the mainstream of pest management science and continue to regress into a foot race with nature. In this report, we establish why a total system approach is essential as the guiding premise of pest management and provide arguments as to how earlier attempts for change and current mainstream initiatives generally fail to follow this principle. We then draw on emerging knowledge about multitrophic level interactions and other specific findings about management of ecosystems to propose a pivotal redirection of pest management strategies that would honor this principle and, thus, be sustainable. Finally, we discuss the potential immense benefits of such a central shift in pest management philosophy.
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Recent predictions of growth in human populations and food supply suggest that there will be a need to substantially increase food production in the near future. One possible approach to meeting this demand, at least in part, is the control of pests and diseases, which currently cause a 30–40% loss in available crop production. In recent years, strategies for controlling pests and diseases have tended to focus on short-term, single-technology interventions, particularly chemical pesticides. This model frequently applies even where so-called integrated pest management strategies are used because in reality, these often are dominated by single technologies (e.g., biocontrol, host plant resistance, or biopesticides) that are used as replacements for chemicals. Very little attention is given to the interaction or compatibility of the different technologies used. Unfortunately, evidence suggests that such approaches rarely yield satisfactory results and are unlikely to provide sustainable pest control solutions for the future. Drawing on two case histories, this paper demonstrates that by increasing our basic understanding of how individual pest control technologies act and interact, new opportunities for improving pest control can be revealed. This approach stresses the need to break away from the existing single-technology, pesticide-dominated paradigm and to adopt a more ecological approach built around a fundamental understanding of population biology at the local farm level and the true integration of renewable technologies such as host plant resistance and natural biological control, which are available to even the most resource-poor farmers.
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The food system dominates anthropogenic disruption of the nitrogen cycle by generating excess fixed nitrogen. Excess fixed nitrogen, in various guises, augments the greenhouse effect, diminishes stratospheric ozone, promotes smog, contaminates drinking water, acidifies rain, eutrophies bays and estuaries, and stresses ecosystems. Yet, to date, regulatory efforts to limit these disruptions largely ignore the food system. There are many parallels between food and energy. Food is to nitrogen as energy is to carbon. Nitrogen fertilizer is analogous to fossil fuel. Organic agriculture and agricultural biotechnology play roles analogous to renewable energy and nuclear power in political discourse. Nutrition research resembles energy end-use analysis. Meat is the electricity of food. As the agriculture and food system evolves to contain its impacts on the nitrogen cycle, several lessons can be extracted from energy and carbon: (i) set the goal of ecosystem stabilization; (ii) search the entire production and consumption system (grain, livestock, food distribution, and diet) for opportunities to improve efficiency; (iii) implement cap-and-trade systems for fixed nitrogen; (iv) expand research at the intersection of agriculture and ecology, and (v) focus on the food choices of the prosperous. There are important nitrogen-carbon links. The global increase in fixed nitrogen may be fertilizing the Earth, transferring significant amounts of carbon from the atmosphere to the biosphere, and mitigating global warming. A modern biofuels industry someday may produce biofuels from crop residues or dedicated energy crops, reducing the rate of fossil fuel use, while losses of nitrogen and other nutrients are minimized.
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Focusing on an overlapping protected area and indigenous territory in the Bolivian Amazon, this article discusses how indigenous people continue to negotiate access to natural resources. Using the theoretical framework of New Institutionalism, ethnographic data from participatory observations, and interviews with Takana indigenous resource users and park management staff, we identified four phases of institutional change. We argue that under the current institutionally pluralistic setting in the overlapping area, indigenous users apply “institutional shopping” to choose, according to their power and knowledge, the most advantageous institutional framework in a situation. Indigenous users strategically employed arguments of conservation, indigeneity, or long-term occupation to legitimize their claims based on the chosen institution. Our results highlight the importance of ideologies and bargaining power in shaping the interaction of individuals and institutions. As a potential application of our research to practice, we suggest that rather than seeing institutional pluralism solely as a threat to successful resource management, the strengths of different frameworks may be combined to build robust institutions from the bottom up that are adapted to the local context. This requires taking into account local informal institutions, such as cultural values and beliefs, and integrating them with conservation priorities through cross-cultural participatory planning.
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Mode of access: Internet.
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"SW-169.1-3."
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Federal Highway Administration, Washington, D.C.
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v.1. The house, its plan, decoration and care / by Isabel Bevier. -- v.2. Household bacteriology / by S. Maria Elliott. -- v.3. Household hygiene / by S. Maria Elliott. -- v.4. Chemistry of the household / by Margaret E. Dodd. -- v.5. Principles of cookery / by Anna Barrows. -- v.6. Food and dietetics / by Alice P. Norton. -- v.7. Household management by Bertha M. Terrill. -- v.8. Personal hygiene / ed. by M. Le Bosquet. -- v.9. Home care of the sick / by Amy E. Pope. -- v.10. Textiles and clothing / by Kate H. Watson. -- v.11. Study of child life / by Marion F. Washburne. -- v.12. Care of children / by A.C. Cotton.
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Prepared for the Institute for Computer Sciences and Technology, National Bureau of Standards.
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Mode of access: Internet.
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Thesis--University of Maryland.
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v. 1. System and program description.--v. 2. Error Messages.--v. 3. Summary of control cards.--v. 4. Sample jobs.--v. 5. Formulas and statistical references.--v. 6. Primer.
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"June 1999."
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Includes bibliographical references (p. 48-49).
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Includes bibliographical references (p. 17-19).