834 resultados para Management control


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This paper describes the development of an experimental distributed fuzzy control system for heating and ventilation (HVAC) systems within a building. Each local control loop is affected by a number of local variables, as well as information from neighboring controllers. By including this additional information it is hoped that a more equal allocation of resources can be achieved.

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Iron is both an essential nutrient for the growth of microorganisms, as well as a dangerous metal due to its capacity to generate reactive oxygen species (ROS) via the Fenton reaction. For these reasons, bacteria must tightly control the uptake and storage of iron in a manner that restricts the build-up of ROS. Therefore, it is not surprising to find that the control of iron homeostasis and responses to oxidative stress are coordinated. The mechanisms concerned with these processes, and the interactions involved, are the subject of this review.

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Value chain studies, including production system and market chain studies, are essential to value chain analysis, which when coupled with disease risk analysis is a powerful tool to identify key constraints and opportunities for disease control based on risk management in a livestock production and marketing system. Several production system and market chain studies have been conducted to support disease control interventions in South East Asia. This practical aid summarizes experiences and lessons learned from the implementation of such value chain studies in South East Asia. Based on these experiences it prioritizes the required data for the respective purpose of a value chain study and recommends data collection as well as data analysis tools. This practical aid is intended as an adjunct to the FAO value chain approach and animal diseases risk management guidelines document. Further practical advice is provided for more effective use of value chain studies in South and South East Asia as part of animal health decision support.

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The European Commission’s Biocidal Products Directive (Council Directive 98/8 EC), known as the BPD, is the largest regulatory exercise ever to affect the urban pest control industry. Although focussed in the European Union its impact is global because any company selling pest control products in the EU must follow its principles. All active substances, belonging to 23 different biocidal product types, come within the Directive’s scope of regulatory control. This will eventually involve re-registration of all existing products, as well as affecting any new product that comes to the market. Some active substances, such as the rodenticides and insecticides, are already highly regulated in Europe but others, such as embalming fluids, masonry preservatives, disinfectants and repellents/attractants will come under intensive regulatory scrutiny for the first time. One of the purposes of the Directive is to offer enhanced protection for human health and the environment. The potential benefit for suppliers of pest control products is mutual recognition of regulatory product dossiers across 25 Member States of the European Union. This process, requiring harmonisation of all regulatory decision-making processes, should reduce duplicated effort and, potentially, allow manufacturers speedier access to European markets. However, the cost to industry is enormous, both in terms of the regulatory resources required to assemble BPD dossiers and the development budgets required to conduct studies to meet its new standards. The cost to regulatory authorities is also tremendous, in terms of the need to upgrade staff capabilities to meet new challenges and the volume of the work expected by the Commission when they are appointed the Rapporteur Member State (RMS) for an active substance. Users of pest control products will pay a price too. The increased regulatory costs of maintaining products in the European market are likely to be passed on, at least in part, to users. Furthermore, where the costs of meeting new regulatory requirements cannot be recouped from product sales, many well-known products may leave the market. For example, it seems that in future few rodenticides that are not anticoagulants will be available within the EU. An understanding of the BPD is essential to those who intend to place urban pest control products on the European market and may be useful to those considering the harmonisation of regulatory processes elsewhere. This paper reviews the operation of the first stages of the BPD for rodenticides, examines the potential benefits and costs of the legislation to the urban pest control industry and looks forward to the next stages of implementation involving all insecticides used in urban pest management.

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Johne's disease in cattle is a contagious wasting disease caused by Mycobacterium avium subspecies paratuberculosis (MAP). Johne's infection is characterised by a long subclinical phase and can therefore go undetected for long periods of time during which substantial production losses can occur. The protracted nature of Johne's infection therefore presents a challenge for both veterinarians and farmers when discussing control options due to a paucity of information and limited test performance when screening for the disease. The objectives were to model Johne's control decisions in suckler beef cattle using a decision support approach, thus implying equal focus on ‘end user’ (veterinarian) participation whilst still focusing on the technical disease modelling aspects during the decision support model development. The model shows how Johne's disease is likely to affect a herd over time both in terms of physical and financial impacts. In addition, the model simulates the effect on production from two different Johne's control strategies; herd management measures and test and cull measures. The article also provides and discusses results from a sensitivity analysis to assess the effects on production from improving the currently available test performance. Output from running the model shows that a combination of management improvements to reduce routes of infection and testing and culling to remove infected and infectious animals is likely to be the least-cost control strategy.

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This paper presents the development of an export coefficient model to characterise the rates and sources of P export from land to water in four reservoir systems located in a semi-arid rural region in southern of Portugal. The model was developed to enable effective management of these important water resource systems under the EU Water Framework Directive. This is the first time such an approach has been fully adapted for the semi-arid systems typical of Mediterranean Europe. The sources of P loading delivered to each reservoir from its catchment were determined and scenario analysis was undertaken to predict the likely impact of catchment management strategies on the scale of rate of P loading delivered to each water body from its catchment. The results indicate the importance of farming and sewage treatment works/collective septic tanks discharges as the main contributors to the total diffuse and point source P loading delivered to the reservoirs, respectively. A reduction in the total P loading for all study areas would require control of farming practices and more efficient removal of P from human wastes prior to discharge to surface waters. The scenario analysis indicates a strategy based solely on reducing the agricultural P surplus may result in only a slow improvement in water quality, which would be unlikely to support the generation of good ecological status in reservoirs. The model application indicates that a reduction of P-inputs to the reservoirs should first focus on reducing P loading from sewage effluent discharges through the introduction of tertiary treatment (P-stripping) in all major residential areas. The fully calibrated export coefficient modelling approach transferred well to semi-arid regions, with the only significant limitation being the availability of suitable input data to drive the model. Further studies using this approach in semi-arid catchments are now needed to increase the knowledge of nutrient export behaviours in semi-arid regions.

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1. Nutrient concentrations (particularly N and P) determine the extent to which water bodies are or may become eutrophic. Direct determination of nutrient content on a wide scale is labour intensive but the main sources of N and P are well known. This paper describes and tests an export coefficient model for prediction of total N and total P from: (i) land use, stock headage and human population; (ii) the export rates of N and P from these sources; and (iii) the river discharge. Such a model might be used to forecast the effects of changes in land use in the future and to hindcast past water quality to establish comparative or baseline states for the monitoring of change. 2. The model has been calibrated against observed data for 1988 and validated against sets of observed data for a sequence of earlier years in ten British catchments varying from uplands through rolling, fertile lowlands to the flat topography of East Anglia. 3. The model predicted total N and total P concentrations with high precision (95% of the variance in observed data explained). It has been used in two forms: the first on a specific catchment basis; the second for a larger natural region which contains the catchment with the assumption that all catchments within that region will be similar. Both models gave similar results with little loss of precision in the latter case. This implies that it will be possible to describe the overall pattern of nutrient export in the UK with only a fraction of the effort needed to carry out the calculations for each individual water body. 4. Comparison between land use, stock headage, population numbers and nutrient export for the ten catchments in the pre-war year of 1931, and for 1970 and 1988 show that there has been a substantial loss of rough grazing to fertilized temporary and permanent grasslands, an increase in the hectarage devoted to arable, consistent increases in the stocking of cattle and sheep and a marked movement of humans to these rural catchments. 5. All of these trends have increased the flows of nutrients with more than a doubling of both total N and total P loads during the period. On average in these rural catchments, stock wastes have been the greatest contributors to both N and P exports, with cultivation the next most important source of N and people of P. Ratios of N to P were high in 1931 and remain little changed so that, in these catchments, phosphorus continues to be the nutrient most likely to control algal crops in standing waters supplied by the rivers studied.

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A manageable, relatively inexpensive model was constructed to predict the loss of nitrogen and phosphorus from a complex catchment to its drainage system. The model used an export coefficient approach, calculating the total nitrogen (N) and total phosphorus (P) load delivered annually to a water body as the sum of the individual loads exported from each nutrient source in its catchment. The export coefficient modelling approach permits scaling up from plot-scale experiments to the catchment scale, allowing application of findings from field experimental studies at a suitable scale for catchment management. The catchment of the River Windrush, a tributary of the River Thames, UK, was selected as the initial study site. The Windrush model predicted nitrogen and phosphorus loading within 2% of observed total nitrogen load and 0.5% of observed total phosphorus load in 1989. The export coefficient modelling approach was then validated by application in a second research basin, the catchment of Slapton Ley, south Devon, which has markedly different catchment hydrology and land use. The Slapton model was calibrated within 2% of observed total nitrogen load and 2.5% of observed total phosphorus load in 1986. Both models proved sensitive to the impact of temporal changes in land use and management on water quality in both catchments, and were therefore used to evaluate the potential impact of proposed pollution control strategies on the nutrient loading delivered to the River Windrush and Slapton Ley

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Disease in farm animals has significant economic impacts on livestock production and incurs substantial costs for societies. Impacts affect not only livestock farms and the livestock industries but also sectors outside of farming. Important negative externalities of livestock disease include impacts on the health of other producers’ livestock, on human health, and on animal welfare. Good disease risk management/biosecurity and good animal welfare are public goods. Not taking account of these externality and public good aspects can lead to a misallocation of resources for livestock disease control. In such instances, there may be a strong case for government or other authority to intervene to ensure a better use of resources. There are a number of policy instruments that can be implemented for this purpose. One potential instrument is a Farm Animal Health and Welfare Stewardship Scheme funded under Pillar II of the CAP. A number of countries have public–private partnership cost-sharing schemes that aim to share appropriately both responsibilities and costs of epidemic livestock disease. There is a strong future agenda for appropriate intervention by governments in the management of livestock disease risks, including responsibility and cost sharing for livestock disease control, within the European Union and elsewhere.

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The South African government has endeavoured to strengthen property rights in communal areas and develop civil society institutions for community-led development and natural resource management. However, the effectiveness of this remains unclear as the emergence and operation of civil society institutions in these areas is potentially constrained by the persistence of traditional authorities. Focusing on the former Transkei region of Eastern Cape Province, three case study communities are used examine the extent to which local institutions overlap in issues of land access and control. Within these communities, traditional leaders (chiefs and headmen) continue to exercise complete and sole authority over land allocation and use this to entrench their own positions. However, in the absence of effective state support, traditional authorities have only limited power over how land is used and in enforcing land rights, particularly over communal resources such as rangeland. This diminishes their local legitimacy and encourages some groups to contest their authority by cutting fences, ignoring collective grazing decisions and refusing to pay ‘fees’ levied on them. They are encouraged in such activities by the presence of democratically elected local civil society institutions such as ward councillors and farmers’ organisations, which have broad appeal and are increasingly responsible for much of the agrarian development that takes place, despite having no direct mandate over land. Where it occurs at all, interaction between these different institutions is generally restricted to approval being required from traditional leaders for land allocated to development projects. On this basis it is argued that a more radical approach to land reform in communal areas is required, which transfers all powers over land to elected and accountable local institutions and integrates land allocation, land management and agrarian development more effectively.

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Grass buffer strips have been widely sown to mitigate against intensive agricultural management practices that have negatively impacted on invertebrate and plant biodiversity in arable farming systems. Typically, such strips are floristically species poor and are dominated by grasses. In the present study, we developed management practices to enhance the floristic and structural diversity of these existing strips for the benefit of spiders, a key provider of natural pest control in crops. Across three UK arable farms, we investigated the benefits of: (i) scarification to create germination niches into which wildflower seeds were sown and (ii) the effect of graminicide applications to suppress grass dominance. Spiders were sampled twice per year (July and September) during 2008 and 2009. The combination of scarification with wildflower seeds, as well as graminicide, resulted in the greatest wildflower cover and lowest grass cover, with a general trend of increased abundance of adult and juvenile spiders. The abundance of Pachygnatha degeeri, Bathyphantes gracilis and juvenile wolf spiders of the genus Pardosa was positively correlated with wildflower cover, probably reflecting increased prey availability. Sward structure was negatively correlated with Erigone atra, Oedothorax fuscus and juvenile Pardosa abundance. Management that utilizes existing commonly adopted agri-environment options, such as grass buffer strips, represents a potentially important conservation tool for increasing the quantity and quality of invertebrate habitats. This can maximize opportunities for the provision of multiple ecosystem services, including pest regulation by predators such as spiders. These management practices have the potential to be incorporated into existing U.K. and European agri-environment schemes.

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The experience of earworms, a type of involuntary musical imagery, may reflect a systematic failure in mental control. This study focused on how individual differences in each of two factors, schizotypy, or “openness to experience”, and thought suppression might relate to the appearance of the involuntary musical image (earworm). Schizotypy, was measured by Raine’s schizotypal personality questionnaire (SPQ; Raine, 1991) and thought suppression was measured by the White Bear Suppression Inventory (WBSI; Wegner & Zanakos, 1994). Each was found to contribute independently to the overall experience of involuntary musical imagery. Schizotypy was correlated with the length and disruptiveness of earworms, the difficulty with which they were dismissed and the worry they caused, but was not correlated with the frequency of such intrusive imagery. In turn, schizotypy was predicted by suppression and intrusion components of WBSI. The WBSI is associated with the length, disruptiveness, difficulty dismissing and interference but not with the worry caused or the frequency of earworms. The assumption of “ownership” of earworms was also found to affect the extent to which the earworms were considered worrying. Multiple regression analysis showed that both schizotypy and the WBSI predicted the difficulty with which unwanted musical images were dismissed, but that the WBSI accounted for additional variance on top of that accounted for by schizotypy. Finally we consider how earworm management might relate to wider cognitive processes.