76 research outputs found

    Effects of shade level and microenvironment on vegetative growth, physiological and biochemical characteristics of transplanted cucumber (Cucumis sativus)

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    Growing vegetables through transplantation under black shade nets is currently becoming popular to provide protection from high intensities of light and high temperatures. This study evaluated the effects of shade level on microenvironment, vegetative growth, photosynthetic pigments, chlorophyll a fluorescence, osmoprotectants, plant water status and leaf mineral nutrients of greenhouse-grown summer cucumber transplants at 25%, 50%, 63%, and 75% shade levels. Solar radiation and tempera-ture decreased with increased shading levels. Average daily temperatures were approximately decreased by 1.5oC under 75% shade nets compared to the 25% shade nets. Vegetative growth characteristics, photosynthetic pigments, chlorophyll a fluorescence (Fv/Fm, Fv/F0, and PI), dehydration tolerance and Leaf N, P and K concentrations increased when shade level increased. Chlorophyll a fluorescence (Fv/Fm, Fv/F0, and PI) reduced with the increase of solar radiation levels. Also, clear decreases in free proline, soluble sugars and total free amino acids in both experiments with increased shade level have been observed. Additionally, relative water content (RWC), membrane stability index (MSI) and electrolyte leakage (EL) of cucumber transplants were significantly affected in both experiments by shade level. Moreover Shade level affected leaf mineral nutrient but the effect differed among nutrients concentration. This study concluded that, nets with higher shading levels (63 and/or 75%) are a potential alternative to alleviate photo-inhibition and heat stress in cucumber transplants production

    Individual Readiness for Change in the Context of Enterprise Resource Planning Systems Implementation

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    The present study takes a bottom-up approach and investigates the organizational implications of ERP systems implementation in organizations. We adopt a likely point of view of employees and study the ERP integration process along 3 dimensions: people, processes, and information. In this manner we discover the ERP-specific sources of resistance that could affect negatively the deployment of the software. Then, we argue that a general set of beliefs shapes employees readiness to change to ERP use and provides the foundation for resistance or for adoptive behavior. We define the concept of readiness for change in the context of ERP and introduce a readiness for change assessment approach. Then, we test empirically the study hypotheses upon which the research model was build. The results obtained offer insights into factors that can improve the effectiveness of ERP implementation strategies and underline the importance of change management for the success of such projects

    Cost per responder for ixekizumab and other biologic drugs approved for the treatment of moderate-to-severe plaque psoriasis in Italy

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    This analysis was aimed at estimating the cost per responder as measured by number needed to treat of ixekizumab as compared with other biologic drugs approved in Italy for the treatment of moderate-to-severe plaque psoriasis. The clinical efficacy was assessed in terms of number needed to treat, based on a network meta-analysis of published efficacy data as measured by Psoriasis Area and Severity Index response (PASI75, PASI90, and PASI100) for relevant biologic comparators. The cost was based on the number of administrations dispensed in the first (induction plus maintenance period) and the second (maintenance period only) year of treatment and the ex-factory price net of discounts of each biologic drug. The cost per responder was adopted as a cost-effectiveness indicator. Independent of the Psoriasis Area and Severity Index response (PASI75, PASI90, and PASI100) used and the year of treatment considered, the cost per number needed to treat for ixekizumab appeared consistently to be the lowest. For example, considering first-year costs and PASI75, the cost per responder for ixekizumab was ā‚¬16,388, compared to adalimumab (ā‚¬22,574), etanercept (branded original: ā‚¬32,420; biosimilar: ā‚¬21,432), secukinumab (ā‚¬17,937), and ustekinumab (ā‚¬20,014). The differences in the cost per responder between ixekizumab and the comparators increased when higher Psoriasis Area and Severity Index response levels were considered. This economic assessment confirmed that ixekizumab is a cost-efficient option from the perspective of the Italian National Health Service for the treatment of moderate-to-severe plaque psoriasis

    29th Annual International INCOSE Symposium

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    Asset planning is a complex and dynamic problem, where the decision maker is often faced with the challenge of making decisions now about aspects that will change over the asset lifetime. This paper is a part of an ongoing study whose goal is to develop decisionā€support methods and tools (qualitative and quantitative) to support asset planning. In this context, this paper's objective is to demonstrate an integrated approach for combining System Dynamics (SD) and Multiā€criteria Decisionā€Making (MCDM). To support the design approach, the paper uses a multiā€method design framework, from the wider Operations Research/Management Science (OR/MS) literature, as a theoretical lens to review and synthesize literature. To apply and test this approach in practice, the paper uses as a test case the classic asset replacement problem from the asset management literature. The test case is applied in a realā€life decision support project for fleet planning in a military organization. Results showcase the value of using SD (qualitative and quantitative) methods and MCDM, both independently and integrated, to support asset planning

    MODSIM 2017: Managing cumulative risks through model-based processes

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    The decision making of complex systems is challenging because of the presence of non-linearities and time delays in their structure and their behaviour. This decision making over the system lifetime is also challenged by the presence of deep uncertainty in the future behaviour of systems and in their surrounding environment. Traditional modelling approaches are inclined to consolidate all facts into a single ultimate model and to take a deterministic, optimal and predictive approach in decision making. However, they proved to be inadequate for coping with complexity and uncertainty challenges. We argue that an exploratory multi-method approach to modelling is needed for making effective and robust decisions for complex systems; the decisions which remain valid under a diverse range of future conditions. This paper illustrates the combined use of multi-method modelling and exploratory analysis in the support of complex systems decision making, with an application to asset acquisition and management and using the case of aircraft fleet as an illustrative example. First, a framework is introduced for the implementation of this multi-method exploratory approach in practice, and the model structure, developed for the case of aircraft fleet, is explained. We then discuss how the use of our new approach can improve the robustness of decisions in asset acquisition and management. An initial exploratory analysis is performed on the model under deep uncertainty conditions and with three design strategies: High Acquisition ā€“ Low Maintenance, Low Acquisition ā€“ High Maintenance, and Medium Acquisition ā€“ Medium Maintenance. The analysis of the results shows that investing on the maintenance capacity of an aircraft fleet could result in more average flying hours compared to more acquisition of new aircraft. However, this could cause two side-effects: a higher total (acquisition and maintenance) costs and a wider uncertainty in the future performance of the system (in terms of average flying hours and total costs)

    24th International Congress on Modelling and Simulation

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