40 research outputs found

    Prospects fro automobile recycling, an integrated approach of systems dynamics and life-cycle assessment

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    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.Includes bibliographical references (leaves 139-142).by Chialin Chen.M.S

    Exploring the Relationship between Vehicle Safety and Fuel Efficiency in Automotive Design

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    Panel data analysis is used within a fixed effect model to examine the relationship between vehicle safety ratings and fuel efficiency of  45 new vehicle models sold in the between 2002 and 2007. While conventional wisdom and most early literature suggest that lighter, more fuel efficient vehicles are less safe to their occupants, the tests show a positive relationship between vehicle safety ratings and fuel efficiencies not only within and across most size classes but also for vehicles produced by both the US and Asian automakers.We also explore the design initiatives by manufacturers to compensate for the reductions in weight/size of fuel-efficient vehicles.This article will be published in Transportation Research Part D 15 (2010) 112-116

    A study on the effects of the Qihuang Needle therapy on patients with Parkinson's disease

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    ObjectiveThis study aimed to evaluate the effectiveness of the Qihuang Needle (QHN) in treating Parkinson's disease (PD).Design, setting, and participantsThe trial was an 8-week randomized clinical trial (4 weeks of treatment followed by 4 weeks of follow-up) conducted from January 2021 to July 2022 in outpatient settings at three clinical sites in Guangzhou, China. Thirty-four participants with PD were diagnosed based on the diagnostic criteria formulated by the brain bank of the British Parkinson's Disease Society in 1992.InterventionsPatients in the treatment and control groups received six sessions within 4 weeks of the QHN therapy or the sham acupuncture therapy (two times per week for the first two consecutive weeks and one time per week for the following two consecutive weeks).Main outcomes and measuresThe primary outcome measure was the change in the Parkinson's Disease Rating Scale-Part III Motor Examination (UPDRS III) between baseline and 8 weeks after treatments. Secondary outcome measures were the Non-Motor Symptoms Scale for Parkinson's Disease (NMSS) and Parkinson's Disease Daily Quality of Life-39 (PDQ-39). Real-time shear wave elastography (SWE) was assessed for each patient at baseline and during the 4-week period as the third outcome measure.ResultsA more significant reduction of UPDRS III score, PDQ-39, NMSS, and SWE was observed in the QHN group than in the sham acupuncture group.ConclusionsThe QHN therapy consistently demonstrated superiority and produced clinically meaningful benefits in reducing motor and non-motor symptoms, as well as significantly improving muscle stiffness, in patients with PD

    Glucocorticoid signaling enhances expression of glucose-sensing molecules in immature pancreatic beta-like cells derived from murine embryonic stem cells in vitro

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    Pluripotent stem cells may serve as an alternative source of beta-like cells for replacement therapy of type 1 diabetes; however, the beta-like cells generated in many differentiation protocols are immature. The maturation of endogenous beta cells involves an increase in insulin expression starting in late gestation and a gradual acquisition of the abilities to sense glucose and secrete insulin by week 2 after birth in mice; however, what molecules regulate these maturation processes are incompletely known. Here, we aim to identify small molecules that affect immature beta cells. A cell-based assay, employing pancreatic beta-like cells derived from murine embryonic stem (ES) cells harboring a transgene containing an Insulin 1-promoter driven enhanced green fluorescent protein reporter, was used to screen a compound library (NIH Clinical Collection-003). Cortisone, a glucocorticoid, was among five positive hit compounds. Quantitative RT-PCR analysis revealed that glucocorticoids enhance the gene expression of not only insulin 1 but also glucose transporter-2 (Glut2; Slc2a2) and glucokinase (Gck), two molecules important for glucose sensing. Mifepristone, a pharmacological inhibitor of glucocorticoid receptor (GR) signaling, reduced the effects of glucocorticoids on Glut2 and Gck expression. The effects of glucocorticoids on ES-derived cells were further validated in immature primary islets. Isolated islets from 1-week-old mice had an increased Glut2 and Gck expression in response to a 4-day treatment of exogenous hydrocortisone in vitro. Gene deletion of GR in beta cells using rat insulin 2 promoter-driven Cre crossed with GRflox/flox mice resulted in a reduced gene expression of Glut2, but not Gck, and an abrogation of insulin secretion when islets were incubated in 0.5 mM D-glucose and stimulated by 17 mM D-glucose in vitro. These results demonstrate that glucocorticoids positively regulate glucose sensors in immature murine beta-like cells

    An Institutional Theory perspective on sustainable practices across the dairy supply chain

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    AbstractThe need for sustainable practices in the food supply chain, particularly in the area of energy reduction, is becoming acute. The food industry currently has to contend with multiple competing pressures alongside the new challenges of sustainable production. We applied Institutional Theory to explore the role of supermarkets in the development of legitimate sustainable practices across the dairy supply chains. The paper focuses on dairy supply chain organizations and their consumption of energy. We conducted 70 semi-structured telephone interviews with various stakeholders across the supply chain. Findings revealed that the majority of actors in the supply chain identified supermarkets as the dominant player, and that the supermarkets exert pressure on other smaller organizations across the supply chain. Although some organizations wished to pursue a sustainable agenda through integrating new rules and legitimate practices within their own organization, the dominant logic appeared to be one of cost reduction and profit maximization. There was also evidence that supermarkets and other large organizations attempt to replicate publicly available information on green successes for image purposes. We conclude that the dominant logic of cost reduction is so well established that challenging the dominant logic may prove difficult. The challenge is therefore to complement the dominant logic with sustainable practices across the whole supply chain, a role Government needs to play. This will require a broader more systemic approach to encouraging sustainable practices including investment and financing practices, so that all members of the dairy supply chain can co-operate and contribute to energy reduction

    Chemical exchange saturation transfer MRI in central nervous system tumours on a 1.5 T MR-Linac

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    Purpose: To describe the implementation and initial results of using Chemical Exchange Saturation Transfer (CEST) for monitoring patients with central nervous system (CNS) tumours treated using a 1.5 tesla MR-guided radiotherapy system. Methods: CNS patients were treated with up to 30 fractions (total dose up to 60 Gy) using a 1.5 T Elekta Unity MR-Linac. CEST scans were obtained in 54 subjects at one or more time points during treatment. CEST metrics, including the amide magnetization transfer ratio (MTRAmide), nuclear Overhauser effect (NOE) MTR (MTRNOE) and asymmetry, were quantified in phantoms and CNS patients. The signal was investigated between tumour and white matter, across time, and across disease categories including high- and low-grade tumours. Results: The gross tumour volume (GTV) exhibited lower MTRAmide and MTRNOE and higher asymmetry compared to contralateral normal appearing white matter. Signal changes in the GTV during fractionated radiotherapy were observed. There were differences between high- and low-grade tumours, with higher CEST asymmetry associated with higher grade disease. Conclusion: CEST MRI using a 1.5 T MR-Linac was demonstrated to be feasible for in vivo imaging of CNS tumours. CEST images showed tumour/white-matter contrast, temporal CEST signal changes, and associations with tumour grade. These results show promise for the eventual goal of using metabolic imaging to inform the design of adaptive radiotherapy protocols

    Glucocorticoid signaling enhances expression of glucose-sensing molecules in immature pancreatic beta-like cells derived from murine embryonic stem cells in vitro

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    Pluripotent stem cells may serve as an alternative source of beta-like cells for replacement therapy of type 1 diabetes; however, the beta-like cells generated in many differentiation protocols are immature. The maturation of endogenous beta cells involves an increase in insulin expression starting in late gestation and a gradual acquisition of the abilities to sense glucose and secrete insulin by week 2 after birth in mice; however, what molecules regulate these maturation processes are incompletely known. Here, we aim to identify small molecules that affect immature beta cells. A cell-based assay, employing pancreatic beta-like cells derived from murine embryonic stem (ES) cells harboring a transgene containing an Insulin 1-promoter driven enhanced green fluorescent protein reporter, was used to screen a compound library (NIH Clinical Collection-003). Cortisone, a glucocorticoid, was among five positive hit compounds. Quantitative RT-PCR analysis revealed that glucocorticoids enhance the gene expression of not only insulin 1 but also glucose transporter-2 (Glut2; Slc2a2) and glucokinase (Gck), two molecules important for glucose sensing. Mifepristone, a pharmacological inhibitor of glucocorticoid receptor (GR) signaling, reduced the effects of glucocorticoids on Glut2 and Gck expression. The effects of glucocorticoids on ES-derived cells were further validated in immature primary islets. Isolated islets from 1-week-old mice had an increased Glut2 and Gck expression in response to a 4-day treatment of exogenous hydrocortisone in vitro. Gene deletion of GR in beta cells using rat insulin 2 promoter-driven Cre crossed with GRflox/flox mice resulted in a reduced gene expression of Glut2, but not Gck, and an abrogation of insulin secretion when islets were incubated in 0.5 mM D-glucose and stimulated by 17 mM D-glucose in vitro. These results demonstrate that glucocorticoids positively regulate glucose sensors in immature murine beta-like cells

    Models for Managing Green Product and Process Innovations

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    115 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000.The focus of the dissertation is to integrate Operations Management and Environmental Management, the two functional fields that are of crucial importance for the prosperity and welfare of the human society in the twenty-first century. The current trend of production and operations management, which emphasizes the management of the entire supply chain from raw materials extraction, to manufacturing, to the delivery of final products to customers, presents new opportunities in preventing and resolving the problems of environmental pollution through product and process innovations. In the dissertation, we develop decision and simulation models for managing green product and process innovations. In the model of green product development, we analyze a firm's strategies regarding the number of products introduced and their respective prices and quality levels, and compare the economic and environmental impacts of these strategies. The analytical results show that green product development and stricter environmental standards do not necessarily benefit the environment. In the model of green process management, we analyze a firm's decisions of production planning and inventory control under an uncertain environmental limit. The analytical results show that the firm will use an optimal policy that leads to higher planned production in order to deal with both demand and environmental uncertainties. In addition, we use simulation analysis to develop a decision support system for analyzing the quantitative properties of green process management. The simulation results show that the optimal policy that requires higher production may also result in higher stock levels throughout the entire planning horizon, which increases the environmental risks associated with the storage of certain toxic semi or final products. Based on the analytical results derived from the models of green product development and process management, we propose guidelines that can be used by both operations managers and environmental policy makers. The objective of the research is twofold. For the private sector, the analytical results can be used to guide today's managers in dealing with the increasingly important environmental issues in supply chain management. For the public sector, the research can provide critical insights that can be used to manage and regulate industries on environment-related issues.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

    Design for the Environment: A Quality-Based Model for Green Product Development

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    Green product development, which addresses environmental issues through product design and innovation as opposed to the traditional end-of-pipe-control approach, is receiving significant attention from customers, industries, and governments around the world. In this paper we develop a quality-based model for analyzing the strategic and policy issues concerning the development of products with conflicting traditional and environmental attributes. On the demand side of the problem, we use the framework of conjoint analysis to structure the preferences of the ordinary and green customers. On the supply side, we apply the theories in optimal product design and market segmentation to analyze the producer's strategic decisions regarding the number of products introduced and their prices and qualities. On the policy side, we evaluate the effects of environmental standards on the economic and environmental consequences of green product development. By jointly considering the interactions among the customers' preferences, the producer's product strategies, and the environmental standards imposed by governments, we present some interesting findings that can be used to manage and regulate the development of green products. Two major findings show that green product development and stricter environmental standards might not necessarily benefit the environment.Product Design, Green Marketing, Natural Environment
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