3,856 research outputs found
Agronomical and environmental performances of organic farming in the Seine watershed, France
This work suggests that Soil Surface Balance is a robust indicator to compare the performances of organic agriculture with those of conventional agriculture, even strictly following the rules of rational and optimised application of fertilisers. The results of long term nitrogen budget calculation brought us to seriously reconsider the relevance of the need to increase crop yields, and more broadly to reconsider cropping patterns and production systems. In terms of policy levers for mitigating nitrogen contamination of water resources, only the shift to organic farming provides a possible way to reconcile agricultural production and water quality.
Further, this view points out the need for specific measures to encourage more mixed farming approach to organic farming on a territorial basis, thus reversing a 50 years trend to regional specialization into either crop or livestock farming
Human alteration of the global nitrogen and phosphorus soil balances for the period 1970-2050
The Millennium Ecosystem Assessment scenarios for 2000 to 2050 describe contrasting future developments in agricultural land use under changing climate. Differences are related to the total crop and livestock production and the efficiency of nutrient use in agriculture. The scenarios with a reactive approach to environmental problems show increases in agricultural N and P soil balances in all developing countries. In the scenarios with a proactive attitude, N balances decrease and P balances show no change or a slight increase. In Europe and North America, the N balance will decline in all scenarios, most strongly in the environment-oriented scenarios; the P balance declines (proactive) or increases slowly (reactive approach). Even with rapidly increasing agricultural efficiency, the global N balance, ammonia, leaching and denitrification loss will not decrease from their current levels even in the most optimistic scenario. Soil P depletion seems to be a major problem in large parts of the global grassland are
A Bioecological View of Culturally Sustaining Pedagogy
Culturally sustaining pedagogy (CSP) considers the impacts of schools on communities, explicitly calling upon schools to sustain instead of overlook the cultural modalities of communities of color (Paris, 2012). In this paper, we argue that one important influence schools should have on families is the awareness and knowledge that familiesâ culture are sustained and viewed as âofficial knowledgeâ (Ladson-Billings, 1995) in the education system. We do so by including a perspective found in the disciplines of developmental science, family science, and education, Bronfenbrennerâs bioecological theory. Specifically, we examine the principles of CSP from the Person-Process-Context-Time (PPCT) model within bioecological theory. Furthermore, we problematize the traditional practice of assigning homework and offer an implication for reimagining homework from a CSP lens.
Keywords: culturally sustaining pedagogy, bioecological theory, homework, family storytelling, PPCT mode
Anthropogenic nitrogen autotrophy and heterotrophy of the world's watersheds: Past, present, and future trends
Anthropogenic nitrogen autotrophy of a territory is defined as the nitrogen flux associated with local production of harvested crops and grass consumed by livestock grazing (in kg N/km(2)/yr). Nitrogen heterotrophy is the nitrogen flux associated with local food and feed consumption by humans and domestic animals. These two summarizing characteristics (anthropogenic nitrogen autotrophy and heterotrophy (ANAH)) indicate the degree of anthropogenic perturbation of the nitrogen cycle by agriculture and human consumption: their balance value provides information on either the potential for commercial export or the need to import agricultural goods; in a watershed, their vector sum is related to the nitrogen flux delivered to the sea. These indicators were calculated for all the watersheds in the Global Nutrient Export from Watersheds (NEWS) database for 1970 and 2000, as well as for 2030 and 2050, according to Millennium Ecosystem Assessment scenarios. During this 30 year period, many watersheds shifted from relatively balanced situations toward either more autotrophic or more heterotrophic conditions. This trend is predicted to become more pronounced over the next 50 year
The evolution of the LEP logging database
In January 1992, a project was started to create a system, using an on-line ORACLE database, to allow logging of a multitude of data on the Large Electron Positron Collider (LEP). The aim of this project was to log particle beam characteristics, physics parameters, hardware settings and environmental conditions. Storing and keeping track of this heterogeneous data for a period of at least one year would permit a better understanding of the behavior of the fairly new LEP Collider.After using the logging system for almost four years, nearly three years of which in full operation, the reliability and performance has been proved, endorsing the design of the database and surrounding software. Moreover, the large number of users of the logging database and the huge amount of new requests for data logging shows the high activity and usefulness of this system. Furthermore, in the context of the 1993 and 1995 energy scans, the logged data turns out to be indispensable for thorough monitoring of the LEP beam energy, which is affected by many parameters.Since the commissioning in 1992, the logging database has been subject to an ORACLE migration from version 6 to 7 and a hardware upgrade of the host platform, in order to keep in step with latest technology and future user requirements.This paper describes the evolution and present state of the LEP logging database
LEP Traceability
After more than ten years of production for high energy physics, CERN's current flagship, LEP, will be closed down definitively October 1st, 2000. Starting immediately, some 30,000 tonnes of LEP materials will be removed from the tunnel to make room for LHC installation. The dismantling project is a major undertaking in terms of resources and constraints, which has to be completed in less than one year. Moreover, since LEP is classified as a nuclear installation in France (as if it was a nuclear power plant), special procedures have to be followed in addition to the normal environmental and safety issues. One major facet of the project is the "traceability" of everything that comes out of the LEP tunnel. This implies that each piece of equipment must be identified and tracked from its origin through any temporary storage to its final destination. Special procedures have to be followed for all materials even if they are not radioactive. As much of the equipment as possible will be recycled or disposed of. This paper describes the database design, software and procedures that are envisaged for the implementation of the LEP traceability system
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