107 research outputs found

    MARKETING CONCEPTS APPLIED TO RECYCLABLE MATERIALS

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    Environmental Economics and Policy,

    The combination of qualitative forecasts

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    Composite forecasting has received increasing attention in the literature. However, with the exception of Feather and Kaylen (1987), previous studies of composite forecasting have only considered the combination of cardinal forecasts. Despite the growing importance of qualitative models, the resolution of conflicting qualitative forecasts has received little attention. The main objective of this thesis is the development of a method to combine qualitative forecasts. The second objective of this thesis is to apply the theoretical model to the combination of signals generated from three technical trading systems. For illustrative purposes, five live cattle and six corn futures contracts are used. Out-of-sample forecasts made by the composite and individual trading systems are evaluated by the number of correct positions forecast and profit. The results of this study indicate that the proposed composite method performs well.Includes bibliographical references

    Economic Valuation of Environmental Benefits and the Targeting of Conservation Programs: The Case of the CRP

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    The range of environmental problems confronting agriculture has expanded in recent years. As the largest program designed to mitigate the negative environmental effects of agriculture, the Conservation Reserve Program (CRP) has broadened its initial focus on reductions in soil erosion to consider other landscape factors that may also be beneficial. For example, preserving habitats can help protect wildlife, thus leading to more nature-viewing opportunities. This report demonstrates how nonmarket valuation models can be used in targeting conservation programs such as the CRP.Environmental Economics and Policy,

    Benefits of Protecting Rural Water Quality: An Empirical Analysis

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    Concerns about the impact of farm production on the quality of the Nation's drinking and recreational water resources have risen over the past 10 years. Because point sources of pollution were controlled first, agricultural nonpoint sources have become the Nation's largest remaining single water-quality problem. Both public and private costs of policies that address the conflict between agricultural production and water quality are relevant, but measuring the off-farm benefits and costs of changing water quality is difficult. Many of the values placed on these resources are not measured in traditional ways through market prices. This report explores the use of nonmarket valuation methods to estimate the benefits of protecting or improving rural water quality from agricultural sources of pollution. Two case studies show how these valuation methods can be used to include water-quality benefits estimates in economic analyses of specific policies to prevent or reduce water pollution.water quality, nonpoint source pollution, environmental quality, agricultural production, costs, benefits, Resource /Energy Economics and Policy,

    Calibrating Benefit Function Transfer to Assess the Conservation Reserve Program

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    Benefit transfer offers an inexpensive alternative to conducting an original study to determine economic value. Unfortunately, benefit transfers can also result in biased welfare estimates. In this paper, we suggest a method of calibrating the benefit transfer to reduce this bias. An empirical example to determine the benefits of the Conservation Reserve Program on water-based recreation illustrates the potentially large biases that can result if the transfer is not calibrated

    Calibrating Benefit Function Transfer to Assess the Conservation Reserve Program

    Get PDF
    Benefit transfer offers an inexpensive alternative to conducting an original study to determine economic value. Unfortunately, benefit transfers can also result in biased welfare estimates. In this paper, we suggest a method of calibrating the benefit transfer to reduce this bias. An empirical example to determine the benefits of the Conservation Reserve Program on water-based recreation illustrates the potentially large biases that can result if the transfer is not calibrated

    NASA System Safety Handbook. Volume 2: System Safety Concepts, Guidelines, and Implementation Examples

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    This is the second of two volumes that collectively comprise the NASA System Safety Handbook. Volume 1 (NASASP-210-580) was prepared for the purpose of presenting the overall framework for System Safety and for providing the general concepts needed to implement the framework. Volume 2 provides guidance for implementing these concepts as an integral part of systems engineering and risk management. This guidance addresses the following functional areas: 1.The development of objectives that collectively define adequate safety for a system, and the safety requirements derived from these objectives that are levied on the system. 2.The conduct of system safety activities, performed to meet the safety requirements, with specific emphasis on the conduct of integrated safety analysis (ISA) as a fundamental means by which systems engineering and risk management decisions are risk-informed. 3.The development of a risk-informed safety case (RISC) at major milestone reviews to argue that the systems safety objectives are satisfied (and therefore that the system is adequately safe). 4.The evaluation of the RISC (including supporting evidence) using a defined set of evaluation criteria, to assess the veracity of the claims made therein in order to support risk acceptance decisions

    Expression of CD44 and integrins in bronchial mucosa of normal and mildly asthmatic subjects

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    We have investigated the expression of cell surface markers and leucocyte cell adhesion molecules by immunohistochemistry in bronchial biopsies from 10 mild atopic asthmatics and 8 normal, nonatopic subjects. Significantly increased numbers of eosinophils (p<0.01) were evident in the bronchial submucosa of asthmatic subjects. In epithelium there were more CD44+ (p<0.02) and lymphocyte function-associated antigen-1 (LFA-1)+ (p<0.06) leucocytes in asthmatics than in normal subjects. Bronchial epithelial cells stained positively with anti-CD44 monoclonal antibodies (moAb) in both groups; however, when the staining was expressed as percentage of the total basement membrane, a considerable and highly significant increase was observed in the asthmatics (median 80 vs 22%, p=0.003). Few leucocytes were positive for very late activation antigen (VLA)-1, VLA-2 and VLA-4. The moAb for VLA-6 stained the basement membrane of the bronchial epithelium; while intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were constitutively expressed in endothelium. A positive correlation was found between LFA-1+ cells and activated eosinophils (EG2+) in the submucosa (p<0.005; r(s)=0.80). We conclude that even in mild asthma there is evidence of increased expression of cell surface ligands, and suggest that adhesive mechanisms play a role both in cell recruitment and disease activity.peer-reviewe

    Agri-Environmental Policy at the Crossroads: Guideposts on a Changing Landscape

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    Agri-environmental policy is at a crossroads. Over the past 20 years, a wide range of policies addressing the environmental implications of agricultural production have been implemented at the Federal level. Those policies have played an important role in reducing soil erosion, protecting and restoring wetlands, and creating wildlife habitat. However, emerging agri-environmental issues, evolution of farm income support policies, and limits imposed by trade agreements may point toward a rethinking of agri-environmental policy. This report identifies the types of policy tools available and the design features that have improved the effectiveness of current programs. It provides an indepth analysis of one policy tool that may be an important component of a future policy package-agri-environmental payments. The analysis focuses on issues and tradeoffs that policymakers would face in designing a program of agri-environmental payments.conservation programs, environmental policy, agricultural policy, policy instruments, agricultural program design, soil erosion, nitrogen runoff, Environmental Economics and Policy,

    Identification of key small non-coding MicroRNAs controlling pacemaker mechanisms in the human sinus node

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    BACKGROUND: The sinus node (SN) is the primary pacemaker of the heart. SN myocytes possess distinctive action potential morphology with spontaneous diastolic depolarization because of a unique expression of ion channels and Ca2+-handling proteins. MicroRNAs (miRs) inhibit gene expression. The role of miRs in controlling the expression of genes responsible for human SN pacemaking and conduction has not been explored. The aim of this study was to determine miR expression profile of the human SN as compared with that of non-pacemaker atrial muscle. METHODS AND RESULTS: SN and atrial muscle biopsies were obtained from donor or post-mortem hearts (n=10), histology/ immunolabeling were used to characterize the tissues, TaqMan Human MicroRNA Arrays were used to measure 754 miRs, Ingenuity Pathway Analysis was used to identify miRs controlling SN pacemaker gene expression. Eighteen miRs were significantly more and 48 significantly less abundant in the SN than atrial muscle. The most interesting miR was miR-486-3p predicted to inhibit expression of pacemaking channels: HCN1 (hyperpolarization-activated cyclic nucleotide-gated 1), HCN4, voltage-gated calcium channel (Cav )1.3, and Cav 3.1. A luciferase reporter gene assay confirmed that miR-486-3p can control HCN4 expression via its 3′ untranslated region. In ex vivo SN preparations, transfection with miR-486-3p reduced the beating rate by ≈35±5% (P<0.05) and HCN4 expression (P<0.05). CONCLUSIONS: The human SN possesses a unique pattern of expression of miRs predicted to target functionally important genes. miR-486-3p has an important role in SN pacemaker activity by targeting HCN4, making it a potential target for therapeutic treatment of SN disease such as sinus tachycardia.</p
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