32 research outputs found

    A bi-objective model for scheduling green investments in two-stage supply chains

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    Investing in green technologies to increase sustainability in supply chains has become a common practice for two reasons: the first is directly related to the defense of the environment and people’s health to smooth the emissions of pollutants; the second is the increasing consumer awareness of green products. Despite the higher costs of producing with green technologies and processes, there is also a higher markup on the price of products which rewards the former costs. This study proposes a mathematical model for scheduling green investments over time in a two-stage supply chain to minimize the impact of production on the environment and the economic costs deriving from the investment. The resulting bi-objective model has nonlinear constraints and is solved using a commercial solver. Given its complexity, we propose an upper-bound heuristic and a lower-bound model to reduce the optimality gap attained at a given time limit. Tests on synthetic instances have been conducted, and an example demonstrates the applicability and efficacy of the proposed model

    Sustainable two stage supply chain management: A quadratic optimization approach with a quadratic constraint

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    Designing a supply chain to comply with environmental policy requires awareness of how work and/or production methods impact the environment and what needs to be done to reduce those environmental impacts and make the company more sustainable. This is a dynamic process that occurs at both the strategic and operational levels. However, being environmentally friendly does not necessarily mean improving the efficiency of the system at the same time. Therefore, when allocating a production budget in a supply chain that implements the green paradigm, it is necessary to figure out how to properly recover costs in order to improve both sustainability and routine operations, offsetting the negative environmental impact of logistics and production without compromising the efficiency of the processes to be executed. In this paper, we study the latter problem in detail, focusing on the CO2 emissions generated by the transportation from suppliers to production sites, and by the production activities carried out in each plant. We do this using a novel mathematical model that has a quadratic objective function and all linear constraints except one, which is also quadratic, and models the constraint on the budget that can be used for green investments caused by the increasing internal complexity created by large production flows in the production nodes of the supply network. To solve this model, we propose a multistart algorithm based on successive linear approximations. Computational results show the effectiveness of our proposal

    Hyperhomocysteinemia in developing age and nutritional aspects of folates: an early cardiovascular risk factor

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    elevated plasma levels of homocysteine are associated with an increased risk of atherosclerosis and cardiovascular ischemic events. Despite this evidence, however, there are still concerns about the mechanisms(s) by which homocysteine exerts its pro-atherogenic effect, and it is unclear whether the decreased plasma levels of homocysteine through diet or drugs may be paralleled by a reduction in cardiovascular risk. Experimental studies have shown that many possible mechanisms are implicated in the pro-atherogenic effect of homocysteine. Endothelial function is altered in subjects with hyperhomocysteinemia, and endothelial dysfunction is correlated with plasma levels of homocysteine. Exercise training reduces plasma levels of homocysteine and improves endothelial function, however without evidence of a better outcome. Larger studies are needed in order to demonstrate that the reduction of plasma levels of homocysteine by oral supplementation with folates and vitamins B6 and B12 translates into a decreased incidence of ischemic events, in particular in patients with documented coronary artery disease and ischemic encephalopathy

    Treatment of Acute Diarrhoea: Past and Now

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    Context: Since ancient times diarrhoea has been a highly fatal disease and even today diarrhoea, the topic of this review, is a problem affecting millions of people around the world despite the efforts of governments and professionals from the medical area. Worldwide the most common cause of children’s death is diarrhoea. Evidence Acquisition: Diarrhoea disorders generally appear with watery stools, sometimes mixed with blood, accompanied by abdominal pain, vomiting and fever. The symptoms depend on the content and distribution of body fluid, daily water requirements and physiological water loss in connection with age through sweating, urination and breathing, the degree of fluid and electrolyte loss in the liquid stool. Results: Several effective interventions have been introduced as part of diarrhoea management in the last two decades such as oral rehydration solution, zinc supplementation, vitamin A supplementation and oral administration of antibiotics and vaccines. To reduce the mortality rate, control of safe drinking water, good sanitation and vaccination against typhoid and cholera are recommended, especially in high-risk populations. Probiotics have been proposed, after more than a half of century, as additional therapy in the treatment of acute diarrhoea. Several probiotic strains showed benefit in meta-analyses of randomised controlled trials. Conclusions: Due to the high level of evidence available, the term “oral bacteriotherapy”, used for decades in the prevention and therapy of gastroenteritis in the growing age and adults, has expanded, but probiotics are acquiring significant scientific value based on the results from human trials. The future of probiotics depends on further explanation/elucidation of basic mechanisms, allowing scientists and physicians to maximize their health benefits


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    In this paper, we study a novel green financing model for a three-stage supply chain. The model considers nonlinear relations among CO2 emissions, budget spent for emission control, and quantity of products moved towards and worked in the facilities. Moreover, the model, besides the minimization of CO2 emissions, aims at balancing the commodity flow over the different facilities. The latter objective is represented by the linear combination of two quadratic penalty functions: one associated with the arc flows and the other with the entering flows at the facilities, respectively. The model is solved on both synthetic instances and a realistic network, demonstrating its effectiveness as a tool for strategically supporting green financing decisions in supply chains

    E-learning: misurazione delle differenze di apprendimento tra lezioni tradizionali e lezioni on-line

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    Discussione dei metodi e delle tecniche statistiche di monitoraggio relative all’efficacia della Formazione a Distanza e della formazione in aula