983 resultados para limited resource
Resumo:
Agriculture in limited resource areas is characterized by small farms which an generally too small to adequately support the needs of an average farm family. The farming operation can be described as a low input cropping system with the main energy source being manual labor, draught animals and in some areas hand tractors. These farming systems are the most important contributor to the national economy of many developing countries. The role of tillage is similar in dryland agricultural systems in both the high input (HICS) and low input cropping systems (LICS), however, wet cultivation or puddling is unique to lowland rice-based systems in low input cropping systems. Evidence suggest that tillage may result in marginal increases in crop yield in the short term, however, in the longer term it may be neutral or give rise to yield decreases associated with soil structural degradation. On marginal soils, tillage may be required to prepare suitable seedbeds or to release adequate Nitrogen through mineralization, but in the longer term, however, tillage reduces soil organic matter content, increases soil erodibility and the emission of greenhouse gases. Tillage in low input cropping systems involves a very large proportion of the population and any changes: in current practices such as increased mechanization will have a large social impact such as increased unemployment and increasing feminization of poverty, as mechanization may actually reduce jobs for women. Rapid mechanization is likely to result in failures, but slower change, accompanied by measures to provide alternative rural employment, might be beneficial. Agriculture in limited resource areas must produce the food and fiber needs of their community, and its future depends on the development of sustainable tillage/cropping systems that are suitable for the soil and climatic conditions. These should be based on sound biophysical principles and meet the needs of and he acceptable to the farming communities. Some of the principle requirements for a sustainable system includes the maintenance of soil health, an increase in the rain water use efficiency of the system, increased use of fertilizer and the prevention of erosion. The maintenance of crop residues on the surface is paramount for meeting these requirements, and the competing use of crop residues must be met from other sources. These requirements can be met within a zonal tillage system combined with suitable agroforestry, which will reduce the need for crop residues. It is, however, essential that farmers participate in the development of any new technologies to ensure adoption of the new system. (C) 2001 Elsevier Science B.V. All rights reserved.
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The objective of the present study was to develop and apply the direct immunohistochemistry (D-IHC) assay to search for turkey coronavirus (TCoV) antigens in formalin-fixed embedded-paraffin tissues by the use of biotin-labeled polyclonal antibody. Twenty-eight-day-old embryonated turkey eggs (n = 50) were inoculated with TCoV-purified virus, and 3 d after inoculation, sections from ileum, ileum-cecal junction, and ceca were harvested, fixed in neutral formalin, and embedded in paraffin blocks and used as positive control. In addition, a total of 100 field samples from ileum, ileum-cecal junction, and ceca, collected from 30 to 45-d-old turkeys poults experiencing an outbreak of acute enteritis, were used to search for TCoV by the same D-IHC. All results were compared with those obtained by conventional RT-PCR and indirect fluorescent antibody assay (IFA) for all tested samples. Turkey coronavirus was detected in experimentally infected embryo tissues and also in field samples in 100% of ileum-cecal junction and ceca by the 3 detection procedures. With IFA as a reference assay, sensitivity and specificity of D-IHC were 98 and 58%, whereas sensitivity and specificity of reverse transcription-PCR were 96 and 66%, calculated from the total of tested samples from experimental infection. Each of the examined procedures was highly specific (D-IHC, 93%; RT-PCR, 90%), sensitive (D-IHC, 85%; RT-PCR, 86%), and agreement of both D-IHC and RT-PCR was 99 and 100%, respectively, compared with IFA results obtained from all the field samples. These findings demonstrated the utility of D-IHC for direct detection of TCoV from field samples and considering the sensitivity and specificity found here, can be used as an alternative technique.
Resumo:
For the Wayuu of the Guajira Peninsula of northern Colombia, water procurement has historically been challenging. The ancestral territory of this indigenous pastoral society is windy and arid, with low rainfall, high temperatures and an absence of perennial rivers or streams. In the past, the Wayuu adapted to these environmental conditions by practicing transhumance during the prolonged dry seasons, digging spring wells and artificial ponds and by following guiding principles for water usage. Since the 1930s, the government has made efforts to build additional wind-powered wells and ponds for a growing native population. Notwithstanding, these water solutions have only partly met the necessities; public water sources are limited or unreliable and few attempts are made to generate safe drinking water. Furthermore, the ubiquitous practice of animal husbandry places added pressure on existing sources; livestock consume more water than the human populations in the areas visited. Rapid assessments in four Wayuu areas on the peninsula were conducted by the author and an interdisciplinary team working for the Cerrejón Foundation for Water in La Guajira from 2010 to 2013. The assessments were part of a larger pilot project to design and implement a sustainability plan for reservoir-based water supply systems in the region. This study brings cultural practices and local knowledge to the forefront as key elements for the success of water works and other development projects carried out in Wayuu territory.
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In the cerebral cortex, the small volume of the extracellular space in relation to the volume enclosed by synapses suggests an important functional role for this relationship. It is well known that there are atoms and molecules in the extracellular space that are absolutely necessary for synapses to function (e.g., calcium). I propose here the hypothesis that the rapid shift of these atoms and molecules from extracellular to intrasynaptic compartments represents the consumption of a shared, limited resource available to local volumes of neural tissue. Such consumption results in a dramatic competition among synapses for resources necessary for their function. In this paper, I explore a theory in which this resource consumption plays a critical role in the way local volumes of neural tissue operate. On short time scales, this principle of resource consumption permits a tissue volume to choose those synapses that function in a particular context and thereby helps to integrate the many neural signals that impinge on a tissue volume at any given moment. On longer time scales, the same principle aids in the stable storage and recall of information. The theory provides one framework for understanding how cerebral cortical tissue volumes integrate, attend to, store, and recall information. In this account, the capacity of neural tissue to attend to stimuli is intimately tied to the way tissue volumes are organized at fine spatial scales.
Resumo:
Background. Several medical devices used during hemodynamic procedures, particularly angiographic diagnostic and therapeutic cardiac catheters, are manufactured for single use only. However, reprocessing and reuse of these devices has been reported, to determine the frequency of reuse and reprocessing of single-use medical devices used during hemodynamic procedures in Brazil and to evaluate how reprocessing is performed. Design. National survey, conducted from December 1999 to July 2001. Methods. Most of the institutions affiliated with the Brazilian Society of Hemodynamic and Interventional Cardiology were surveyed by use of a questionnaire sent in the mail. Results. The questionnaire response rate was 50% (119 of 240 institutions). Of the 119 institutions that responded, 116 (97%) reported reuse of single-use devices used during hemodynamic procedures, and only 26 (22%) reported use of a standardized reprocessing protocol. Cleaning, flushing, rinsing, drying, sterilizing and packaging methods varied greatly and were mostly inadequate. Criteria for discarding reused devices varied widely. Of the 119 institutions that responded, 80 (67%) reported having a surveillance system for adverse events associated with the reuse of medical devices, although most of these institutions did not routinely review the data, and only 38 (32%) described a training program for the personnel who reprocessed single-use devices. Conclusions. The reuse of single-use devices used during hemodynamic procedures was very frequent in hospitals in Brazil. Basic guidance on how to reuse and reprocess single-use medical devices is urgently needed, because, despite the lack of studies to support reusing and reprocessing single-use medical devices, such devices are necessary in limited-resource areas in which these practices are current.
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This study investigates the efficacy of clinical criteria in selecting patients for primary tamoxifen therapy. A total of 60 breast cancer patients with large primary tumors and unknown hormonal receptor status were subjected to primary hormone therapy. Inclusion criteria were age over 60 years old or menopausal status for at least 10 years and no clinical evidence of inflammatory disease and fast tumor growth. The objective response rate was 55%. There was a positive correlation between the lack of clinical response and axillary lymph node metastasis (p = 0.009). Patients with objective response had significantly improved disease-free (p = 0.045) and overall (p = 0.0002) survival over those who did not have response to hormonal therapy. In multivariate analysis, the clinical response to therapy was the most powerful prognostic factor. This analysis demonstrates that clinical criteria were very effective predictor of response to neo-adjuvant hormone therapy in large breast tumors for postmenopausal women. Response to therapy is the major prognostic factor in primary tamoxifen-treated breast cancer.
Resumo:
O solo é um recurso multifuncional e vital para a humanidade, apresentando funções ecológicas, técnico-industriais, socioeconómicas e culturais, estabelecendo um vasto capital natural insubstituível. Face à sua taxa de degradação potencialmente rápida que, devido ao crescente desenvolvimento económico e incremento da população mundial, tem vindo a aumentar nas últimas décadas, o solo é, atualmente, um recurso finito e limitado. Devido a esta problemática, o presente documento visa abordar a progressiva preocupação sobre as questões geoambientais e toda a investigação que as envolvem, avaliando o modo como os contaminantes se dispersam pelo solo nas diferentes fases do mesmo (fases sólida, líquida e gasosa). A parte experimental centrou-se na análise da adsorção do benzeno, a partir da determinação das isotérmicas de adsorção. Para tal, foram previamente preparados reatores com calcário, sendo alguns deles previamente contaminados com um biocombustível, biodiesel, a uma concentração constante. Este processo foi monitorizado com base na evolução temporal da concentração na fase gasosa, através da cromatografia gasosa. De entre os objetivos, procurou-se analisar a distribuição dos contaminantes pelas fases constituintes do solo, ajustar os dados experimentais obtidos os modelos matemáticos de Langmuir, Freundlich e Polinomial, e verificar e discutir as soluções mais adequadas.
Resumo:
Water is a limited resource for which demand is growing. Contaminated water from inadequate wastewater treatment provides one of the greatest health challenges as it restricts development and increases poverty in emerging and developing countries. Therefore, the connection between wastewater and human health is linked to access to sanitation and to human waste disposal. Adequate sanitation is expected to create a barrier between disposed human excreta and sources of drinking water. Different approaches to wastewater management are required for different geographical regions and different stages of economic governance depending on the capacity to manage wastewater. Effective wastewater management can contribute to overcome the challenges of water scarcity. Separate collection of human urine at its source is one promising approach that strongly reduces the economic and load demands on wastewater treatment plants (WWTP). Treatment of source-separated urine appears as a sanitation system that is affordable, produces a valuable fertiliser, reduces pollution of water resources and promotes health. However, the technical realisation of urine separation still faces challenges. Biological hydrolysis of urea causes a strong increase of ammonia and pH. Under these conditions ammonia volatilises which can cause odour problems and significant nitrogen losses. The above problems can be avoided by urine stabilisation. Biological nitrification is a suitable process for stabilisation of urine. Urine is a highly concentrated nutrient solution which can lead to strong inhibition effects during bacterial nitrification. This can further lead to process instabilities. The major cause of instability is accumulation of the inhibitory intermediate compound nitrite, which could lead to process breakdown. Enhanced on-line nitrite monitoring can be applied in biological source-separated urine nitrification reactors as a sustainable and efficient way to improve the reactor performance, avoiding reactor failures and eventual loss of biological activity. Spectrophotometry appears as a promising candidate for the development and application of on-line nitrite monitoring. Spectroscopic methods together with chemometrics are presented in this work as a powerful tool for estimation of nitrite concentrations. Principal component regression (PCR) is applied for the estimation of nitrite concentrations using an immersible UV sensor and off-line spectra acquisition. The effect of particles and the effect of saturation, respectively, on the UV absorbance spectra are investigated. The analysis allows to conclude that (i) saturation has a substantial effect on nitrite estimation; (ii) particles appear to have less impact on nitrite estimation. In addition, improper mixing together with instabilities in the urine nitrification process appears to significantly reduce the performance of the estimation model.
Resumo:
Evidence of sustainability, or the potential to achieve this, is increasingly a pre-requisite for OER activity, whether imposed by funders, by institutions requiring a 'business case' for OER, or practitioners themselves - academics, educational technologists and librarians, concerned about how to justify engagement with a unfamiliar, and unproven practices, in today's climate of limited resource. However, it is not clear what is meant by 'sustainability' in relation to OER, what will be needed to achieve or demonstrate this, nor who the expectation of sustainability relates to. This paper draws on experiences of UK OER projects to identify aspirations that those involved in delivering OER activity have for OER sustainability ¿ what a 'manifesto' for OER sustainability beyond project funding, based on OER use, might look like.
Resumo:
RESUM L’aigua és un recurs limitat necessari per a l’establiment de qualsevol forma de vida sobre la Terra. Aquest recurs, es veu regit pel cicle hidrològic i durant les diferents fases del seu cicle, l’aigua pot ser captada per ser aprofitada per l’ésser humà. En els darrers anys, la necessitat d’aigua per a la població ha estat incrementada provocant un impacte negatiu sobre aquest recurs. Per aquest motiu sorgeix la necessitat de crear polítiques globals per protegir l’aigua que vagin encaminades a minimitzar l’efecte negatiu provocat per l’home. Tota captació d’aigua destinada al consum humà ha de garantir uns paràmetres de qualitat i per tal de poder aconseguir aquest objectiu amb eficàcia és imprescindible l’aplicació d’una eina legal molt important: els perímetres de protecció. A l’article 6 de la Llei de policia i protecció de les aigües del 31 de juliol del 1985, s’estableix que tota captació d’aigua potable haurà de quedar aïllada mitjançant un perímetre de protecció, a l’interior del qual no podrà dur-se a terme cap activitat sense prèvia autorització de Govern. Els objectius principals d’aquest estudi son recopilar la informació existent en referència a les captacions d’aigua i els seus respectius perímetres de protecció, elaborar una base de dades que pugui contenir tota la informació existent i elaborar cartografia especifica amb la finalitat de realitzar una diagnosi de la situació actual de les captacions i perímetres associats i identificar els principals riscos potencials existents en aquestes àrees. Entre les conclusions mes rellevants obtingudes amb aquest treball, cal destacar que s’ha constatat que algunes activitats antròpiques potencialment contaminants es troben situades en zones properes a les captacions destinades a consum humà, inclòs dins dels seus perímetres de protecció, amb el conseqüent risc que aquesta situació comporta.
Resumo:
RESUM L’aigua és un recurs limitat necessari per a l’establiment de qualsevol forma de vida sobre la Terra. Aquest recurs, es veu regit pel cicle hidrològic i durant les diferents fases del seu cicle, l’aigua pot ser captada per ser aprofitada per l’ésser humà. En els darrers anys, la necessitat d’aigua per a la població ha estat incrementada provocant un impacte negatiu sobre aquest recurs. Per aquest motiu sorgeix la necessitat de crear polítiques globals per protegir l’aigua que vagin encaminades a minimitzar l’efecte negatiu provocat per l’home. Tota captació d’aigua destinada al consum humà ha de garantir uns paràmetres de qualitat i per tal de poder aconseguir aquest objectiu amb eficàcia és imprescindible l’aplicació d’una eina legal molt important: els perímetres de protecció. A l’article 6 de la Llei de policia i protecció de les aigües del 31 de juliol del 1985, s’estableix que tota captació d’aigua potable haurà de quedar aïllada mitjançant un perímetre de protecció, a l’interior del qual no podrà dur-se a terme cap activitat sense prèvia autorització de Govern. Els objectius principals d’aquest estudi son recopilar la informació existent en referència a les captacions d’aigua i els seus respectius perímetres de protecció, elaborar una base de dades que pugui contenir tota la informació existent i elaborar cartografia especifica amb la finalitat de realitzar una diagnosi de la situació actual de les captacions i perímetres associats i identificar els principals riscos potencials existents en aquestes àrees. Entre les conclusions mes rellevants obtingudes amb aquest treball, cal destacar que s’ha constatat que algunes activitats antròpiques potencialment contaminants es troben situades en zones properes a les captacions destinades a consum humà, inclòs dins dels seus perímetres de protecció, amb el conseqüent risc que aquesta situació comporta.
Resumo:
Soil forms the outer skin of the earth's land surface. Often less than a metre in depth, it is essential to sustain natural terrestrial ecosystems and human life. Soils result from the interactions over time between climate, parent material, topography, vegetation, and biota. They vary from place to place. Mineral soils are composed of mineral matter, organic matter, and gas- or liquid-filled pores in varying proportions. Soils perform a wide range of functions and provide many ecosystem or environmental services; with the climate problem, the soil is increasingly being recognised as a potential sink for carbon from the atmosphere. In part because of humankind's (over)use of soils and in part because of natural and human-induced environmental change, there is a widespread decline in soil quality and an increasing number of threats to soil, which jeopardise both the soil's natural functions and its use by humans. As a limited resource, soils must be used sustainably. Soil protection strategies have been indirectly embodied in a number of United Nations conventions, and there are now national and supranational developments towards specific regulations and legislation to protect soils and their functions.
Resumo:
The preparation of Community Strategies (CS) has been required of LSPs and Local Authorities in England since the passing of the Local Government Act 2000. This paper examines the process and content of two Community Strategies in southern England as part of an ongoing project to understand their impact and explore ways that CSs may be carried through in a meaningful and effective manner. The paper concludes that the two CSs studied illustrate the challenge faced by LSPs in producing Strategies that are meaningful, inclusive and which follow the spirit of the government CS guidance. LAs and LSPs are also posed with a difficult challenge of seeing through an implicitly required transition from a traditional representative democratic structure/process with a more fluid participatory model. Thus we detect that at least two forms of conflict may arise – firstly with elected councillors threatened by a loss of power and secondly between communities and the LAs who are encouraged to problematise local policy and service delivery in the context of limited resource availability.
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In order to best utilize the limited resource of medical resources, and to reduce the cost and improve the quality of medical treatment, we propose to build an interoperable regional healthcare systems among several levels of medical treatment organizations. In this paper, our approaches are as follows:(1) the ontology based approach is introduced as the methodology and technological solution for information integration; (2) the integration framework of data sharing among different organizations are proposed(3)the virtual database to realize data integration of hospital information system is established. Our methods realize the effective management and integration of the medical workflow and the mass information in the interoperable regional healthcare system. Furthermore, this research provides the interoperable regional healthcare system with characteristic of modularization, expansibility and the stability of the system is enhanced by hierarchy structure.
Resumo:
The psychiatric and psychosocial evaluation of the heart transplant candidate can identify particular predictors for postoperative problems. These factors, as identified during the comprehensive evaluation phase, provide an assessment of the candidate in context of the proposed transplantation protocol. Previous issues with compliance, substance abuse, and psychosis are clear indictors of postoperative problems. The prolonged waiting list time provides an additional period to evaluate and provide support to patients having a terminal disease who need a heart transplant, and are undergoing prolonged hospitalization. Following transplantation, the patient is faced with additional challenges of a new self-image, multiple concerns, anxiety, and depression. Ultimately, the success of the heart transplantation remains dependent upon the recipient's ability to cope psychologically and comply with the medication regimen. The limited resource of donor hearts and the high emotional and financial cost of heart transplantation lead to an exhaustive effort to select those patients who will benefit from the improved physical health the heart transplant confers.