2,456 research outputs found

    Analysis of the potentials of multi criteria decision analysis methods to conduct sustainability assessment

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    Sustainability assessments require the management of a wide variety of information types, parameters and uncertainties. Multi criteria decision analysis (MCDA) has been regarded as a suitable set of methods to perform sustainability evaluations as a result of its flexibility and the possibility of facilitating the dialogue between stakeholders, analysts and scientists. However, it has been reported that researchers do not usually properly define the reasons for choosing a certain MCDA method instead of another. Familiarity and affinity with a certain approach seem to be the drivers for the choice of a certain procedure. This review paper presents the performance of five MCDA methods (i.e. MAUT, AHP, PROMETHEE, ELECTRE and DRSA) in respect to ten crucial criteria that sustainability assessments tools should satisfy, among which are a life cycle perspective, thresholds and uncertainty management, software support and ease of use. The review shows that MAUT and AHP are fairly simple to understand and have good software support, but they are cognitively demanding for the decision makers, and can only embrace a weak sustainability perspective as trade-offs are the norm. Mixed information and uncertainty can be managed by all the methods, while robust results can only be obtained with MAUT. ELECTRE, PROMETHEE and DRSA are non-compensatory approaches which consent to use a strong sustainability concept, accept a variety of thresholds, but suffer from rank reversal. DRSA is less demanding in terms of preference elicitation, is very easy to understand and provides a straightforward set of decision rules expressed in the form of elementary “if … then …” conditions. Dedicated software is available for all the approaches with a medium to wide range of results capability representation. DRSA emerges as the easiest method, followed by AHP, PROMETHEE and MAUT, while ELECTRE is regarded as fairly difficult. Overall, the analysis has shown that most of the requirements are satisfied by the MCDA methods (although to different extents) with the exclusion of management of mixed data types and adoption of life cycle perspective which are covered by all the considered approaches

    Explaining Regional and Local Differences in Organic Farming in England and Wales: A Comparison of South West Wales and South East England

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    Explaining regional and local differences in organic farming in England and Wales: a comparison of South West Wales and South East England, Regional Studies, Few studies explain the concentration of organic farming in specific regions of England and Wales. This paper compares the development of organic farming in South West Wales and South East England. While the focus in the former is on the use of mainly national marketing channels and the movement of organic produce more than 60 min from the farm, in the latter greater use is made of local and direct marketing channels to distribute organic food within 30 min of the farm. The overriding importance of demand appears to provide a key explanation for regional differentiation in organic farming. 解释英格兰与威尔斯有机农业的区域及地方差异:西南威尔斯与东南英格兰的比较研究,区域研究。显少有研究解释有机农业在英格兰及威尔斯特定区域中的集中现象。本文比较有机农业在西南威尔斯与东南英格兰的发展。西南威尔斯的发展重点,主要在于利用全国行销通路,以及距离农场超过六十分钟的有机产品运送路程,东南英格兰则较着重运用在地且直接的行销通路,在距离农场三十分钟以内的运送路程中分派有机食品。需求的压倒性重要性,似乎提供了有机农业中的区域差异的关键解释。 Expliquer les disparités régionales dans l'agriculture biologique en Angleterre et au pays de Galles: une comparaison du sud-ouest du pays de Galles et du sud-est de l'Angleterre, Regional Studies. Rares sont les études qui expliquent la concentration de l'agriculture biologique dans des zones spécifiques de l'Angleterre et du pays de Galles. Cet article cherche à comparer le développement de l'agriculture biologique du sud-ouest du pays de Galles à celle du sud-est de l'Angleterre. Tandis que celle-là met l'accent sur l'emploi des circuits commerciaux principalement nationaux et sur la distribution de la production agricole biologique à plus de 60 minutes de la ferme, celle-ci exploite davantage les circuits commerciaux locaux et directs pour distribuer les denrées alimentaires organiques dans un rayon de 30 minutes de la ferme. Il semble que l'importance primordiale de la demande constitue un facteur déterminant de la différenciation régionale de l'agriculture biologique. Erklärung der regionalen und lokalen Unterschiede bei der ökologischen Landwirtschaft in England und Wales: ein Vergleich zwischen Südwestwales und Südostengland, Regional Studies. Die Konzentration der ökologischen Landwirtschaft in bestimmten Regionen von England und Wales wird nur in wenigen Studien erklärt. In diesem Beitrag vergleichen wir die Entwicklung der ökologischen Landwirtschaft in Südwestwales mit der von Südostengland. Während in Südwestwales der Schwerpunkt auf den größtenteils landesweiten Absatzkanälen und dem Transport von ökologischen Lebensmitteln an mehr als 60 Minuten vom landwirtschaftlichen Betrieb entfernte Orte liegt, werden in Südostengland öfter lokale und direkte Absatzkanäle genutzt und die ökologischen Lebensmittel an bis zu 30 Minuten vom landwirtschaftlichen Betrieb entfernte Orte transportiert. Die wichtigste Erklärung für die regionalen Unterschiede bei der ökologischen Landwirtschaft scheinen in der vorrangigen Bedeutung der Nachfrage zu liegen. Explicación de las diferencias regionales y locales en la agricultura biológica de Inglaterra y Gales: comparación entre el suroeste de Gales y el sureste de Inglaterra, Regional Studies. En pocos estudios se explica la concentración de la agricultura biológica en regiones específicas de Inglaterra y Gales. En este artículo comparamos el desarrollo de la agricultura biológica en el suroeste de Gales y el sureste de Inglaterra. Mientras que en el suroeste de Gales se hace hincapié en el uso de canales mercantiles principalmente nacionales y el movimiento de productos biológicos a una distancia de más de 60 minutos de la explotación agrícola, en el sureste de Inglaterra se utilizan más los canales mercantiles locales y directos para distribuir alimentos biológicos a no más de 30 minutos de la explotación agrícola. Parece ser que la demanda es el motivo más importante para explicar las diferencias regionales en la agricultura biológica

    The Hodge--Poincar\'e polynomial of the moduli spaces of stable vector bundles over an algebraic curve

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    Let X be a nonsingular complex projective variety that is acted on by a reductive group GG and such that XssX(0)sX^{ss} \neq X_{(0)}^{s}\neq \emptyset. We give formulae for the Hodge--Poincar\'e series of the quotient X(0)s/GX_{(0)}^s/G. We use these computations to obtain the corresponding formulae for the Hodge--Poincar\'e polynomial of the moduli space of properly stable vector bundles when the rank and the degree are not coprime. We compute explicitly the case in which the rank equals 2 and the degree is even.Comment: Final published version. arXiv admin note: text overlap with arXiv:math/0305346, arXiv:math/0305347 by other author

    Beta radiation for glaucoma surgery

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    Improved hydrogen gas production in microbial electrolysis cells using inexpensive recycled carbon fibre fabrics

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    Growing energy demands of wastewater treatment have made it vital for water companies to develop less energy intensive processes for treating wastewater if net zero emissions are to be achieved by 2050. Microbial electrolysis cells (MECs) have the potential to do this by treating water and producing renewable hydrogen gas as a product, but capital and operational costs have slowed their deployment. By using recycled carbon fibre mats, commercially viable MECs can brought closer to reality, where recycled carbon fibre anode MECs treating real wastewater (normalised ~3100 L d−1) were producing 66.77 L H2 d−1 while graphite felt anode MECs produced 3.65 L H2 d−1 per 1 m3 reactor, anodes costing £5.53 m−2 and £88.36 m−2 respectively, resulting in a total anode cost saving of 93%. This could incentivise the development of larger pilot systems, opening the door for generating greater value and a more sustainable wastewater treatment industry

    Assessing Human Error Against a Benchmark of Perfection

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    An increasing number of domains are providing us with detailed trace data on human decisions in settings where we can evaluate the quality of these decisions via an algorithm. Motivated by this development, an emerging line of work has begun to consider whether we can characterize and predict the kinds of decisions where people are likely to make errors. To investigate what a general framework for human error prediction might look like, we focus on a model system with a rich history in the behavioral sciences: the decisions made by chess players as they select moves in a game. We carry out our analysis at a large scale, employing datasets with several million recorded games, and using chess tablebases to acquire a form of ground truth for a subset of chess positions that have been completely solved by computers but remain challenging even for the best players in the world. We organize our analysis around three categories of features that we argue are present in most settings where the analysis of human error is applicable: the skill of the decision-maker, the time available to make the decision, and the inherent difficulty of the decision. We identify rich structure in all three of these categories of features, and find strong evidence that in our domain, features describing the inherent difficulty of an instance are significantly more powerful than features based on skill or time.Comment: KDD 2016; 10 page

    Metallochaperones Are Needed for Mycobacterium tuberculosis and Escherichia coli Nicotinamidase-Pyrazinamidase Activity.

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    Mycobacterium tuberculosis nicotinamidase-pyrazinamidase (PZAse) is a metalloenzyme that catalyzes conversion of nicotinamide-pyrazinamide to nicotinic acid-pyrazinoic acid. This study investigated whether a metallochaperone is required for optimal PZAse activity. M. tuberculosis and Escherichia coli PZAses (PZAse-MT and PZAse-EC, respectively) were inactivated by metal depletion (giving PZAse-MT-Apo and PZAse-EC-Apo). Reactivation with the E. coli metallochaperone ZnuA or Rv2059 (the M. tuberculosis analog) was measured. This was repeated following proteolytic and thermal treatment of ZnuA and Rv2059. The CDC1551 M. tuberculosis reference strain had the Rv2059 coding gene knocked out, and PZA susceptibility and the pyrazinoic acid (POA) efflux rate were measured. ZnuA (200 μM) achieved 65% PZAse-EC-Apo reactivation. Rv2059 (1 μM) and ZnuA (1 μM) achieved 69% and 34.3% PZAse-MT-Apo reactivation, respectively. Proteolytic treatment of ZnuA and Rv2059 and application of three (but not one) thermal shocks to ZnuA significantly reduced the capacity to reactivate PZAse-MT-Apo. An M. tuberculosis Rv2059 knockout strain was Wayne positive and susceptible to PZA and did not have a significantly different POA efflux rate than the reference strain, although a trend toward a lower efflux rate was observed after knockout. The metallochaperone Rv2059 restored the activity of metal-depleted PZAse in vitro Although Rv2059 is important in vitro, it seems to have a smaller effect on PZA susceptibility in vivo. It may be important to mechanisms of action and resistance to pyrazinamide in M. tuberculosis Further studies are needed for confirmation.IMPORTANCE Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis and remains one of the major causes of disease and death worldwide. Pyrazinamide is a key drug used in the treatment of tuberculosis, yet its mechanism of action is not fully understood, and testing strains of M. tuberculosis for pyrazinamide resistance is not easy with the tools that are presently available. The significance of the present research is that a metallochaperone-like protein may be crucial to pyrazinamide's mechanisms of action and of resistance. This may support the development of improved tools to detect pyrazinamide resistance, which would have significant implications for the clinical management of patients with tuberculosis: drug regimens that are appropriately tailored to the resistance profile of a patient's individual strain lead to better clinical outcomes, reduced onward transmission of infection, and reduction of the development of resistant strains that are more challenging and expensive to treat
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