6,729 research outputs found

    Working with Complexity: a Participatory Systems-Based Process for Planning and Evaluating Rural Water, Sanitation and Hygiene Services

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    Individuals working within the water, sanitation and hygiene for development (WASH) sector grapple daily with complex technical, social, economic, and environmental issues that often produce unexpected outcomes that are difficult to plan for and resolve. Here we propose a method we are calling the ‘Participatory Systems-based Planning and Evaluation Process’ (PS-PEP) that combines structural factor analysis and collaborative modeling to guide teams of practitioners, researchers, and other stakeholders through a process of modeling and interpreting how factors systemically and dynamically influence sustained access to WASH services. The use and utility of the PS-PEP is demonstrated with a regional team of water committee members in the municipality of Jalapa, Nicaragua who participated in a two-day modeling workshop. Water committee members left the workshop with a clear set of action items for water service planning and management in Jalapa, informed by the analysis of systemic influences and dependencies between key service factors. In so doing, we find that the PS-PEP provides a powerful tool for WASH project or program planning, evaluation, management and policy, the continued use of which could offer unprecedented growth in understanding of WASH service complexity for a broad spectrum of service contexts

    The Effect of Nitrogen Fertilisation on the Morphological Development and Growth Rate of Star Grass (\u3cem\u3eCynodon nlemfuensis\u3c/em\u3e)

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    Nitrogen is one of the main inputs used in forage production systems to increase productivity. However, in Cuba, the availability of fertiliser N is limited and therefore if applied, needs to be used with high efficiency. Previous studies (Johnson, 2001, Del Pozo, 2003) investigated the effects of N on growth, carbohydrate and protein content but did not consider morphological changes in Cynodon nlemfuensis. A study was therefore undertaken investigating how N application influences morphological development of the plant and how these changes might affect the efficiency of use of applied N

    Symmetries in Fluctuations Far from Equilibrium

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    Fluctuations arise universally in Nature as a reflection of the discrete microscopic world at the macroscopic level. Despite their apparent noisy origin, fluctuations encode fundamental aspects of the physics of the system at hand, crucial to understand irreversibility and nonequilibrium behavior. In order to sustain a given fluctuation, a system traverses a precise optimal path in phase space. Here we show that by demanding invariance of optimal paths under symmetry transformations, new and general fluctuation relations valid arbitrarily far from equilibrium are unveiled. This opens an unexplored route toward a deeper understanding of nonequilibrium physics by bringing symmetry principles to the realm of fluctuations. We illustrate this concept studying symmetries of the current distribution out of equilibrium. In particular we derive an isometric fluctuation relation which links in a strikingly simple manner the probabilities of any pair of isometric current fluctuations. This relation, which results from the time-reversibility of the dynamics, includes as a particular instance the Gallavotti-Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by time-reversibility on the statistics of nonequilibrium fluctuations. The new symmetry implies remarkable hierarchies of equations for the current cumulants and the nonlinear response coefficients, going far beyond Onsager's reciprocity relations and Green-Kubo formulae. We confirm the validity of the new symmetry relation in extensive numerical simulations, and suggest that the idea of symmetry in fluctuations as invariance of optimal paths has far-reaching consequences in diverse fields.Comment: 8 pages, 4 figure

    Identification of the best-performing novel microbial strains from naturally-aged graffiti for biocleaning research

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    [EN] Microorganisms that can act as biocleaning agents can potentially be isolated from existing graffiti. In this study, a total of 30 different isolates of bacteria, fungi and yeasts were obtained from black, blue, red and silver graffiti coatings exposed outdoors conditions for 10 years. An additional strain was obtained from samples of black powdered graffiti exposed under laboratory conditions for 5 years. Each of the isolates from the most prolific sources (i.e. red and silver graffiti coatings and black powdered graffiti) was evaluated alone and in combination with Tween? 20, to determine their potential as biocleaning agents, in test tube assays. Two strains isolated from the red graffiti coating (identified as Candida parapsilosis) and one strain isolated from the black powered graffiti (identified as Rhodococcus erythropolis) performed best alone. The quantity of live cells throughout the trials and biofilm formation indicated that both strains were able to utilize the paint as a substrate. When the microorganisms isolated were combined with Tween? 20, the quantity of live cells increased notably throughout the incubation time, and turbidity and graffiti discoloration were observed. Infrared spectroscopic examination revealed that R. erythropolis performed the best alone, while the addition of Tween? 20 to C. parapsilosis enhanced the oxidative degradation of the graffiti.J.S. Pozo-Antonio is grateful to the Spanish Ministry of Economy and Competitiveness (MINECO) for a post-doctoral contract (Juan de la Cierva-Incorporacion, IJCI-2017-3277). P. Sanmartin is grateful for financial support from the Xunta de Galicia (grant ED431C 2018/32).Bosch-Roig, P.; Pozo-Antonio, J.; Sanmartín, P. (2021). Identification of the best-performing novel microbial strains from naturally-aged graffiti for biocleaning research. International Biodeterioration & Biodegradation. 159:1-7. https://doi.org/10.1016/j.ibiod.2021.105206S1715

    Relation of Gallbladder Motility to Viscosity and Composition of Gallbladder Bile in Patients with Cholesterol Gallstones

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    Background/Aims: Increased viscosity and supersaturation of cholesterol in gallbladder bile, as well as an impaired motility of the gallbladder, are considered to be important factors in the pathogenesis of cholesterol gallstones. However, the relation of these parameters has not yet been determined. Material and Methods: Bile viscosity (mPa.s) was measured by rotation viscosimetry and the composition of gallbladder bile was determined using standard methodology. Gallbladder motility was calculated as ejection fraction in percent of total volume 45 min after a test meal using ultrasonography in patients with gallstones prior to elective cholecystectomy. Results: The study included 35 patients with cholesterol gallstones. Viscosity of gallbladder bile ranged between 0.9 and 12.5 mPa.s (median 2.2 mPa.s) and an ejection fraction of the gallbladder of 55.4 +/- 18.3% (mean +/- SD) was determined. No significant correlation (r = 0.19, p < 0.2) between the 2 parameters could be calculated. Analysis of the composition of gallbladder bile revealed a positive correlation of all components to biliary viscosity but not to the motility of the gallbladder, with the exceptions of a negative correlation (r = 0.39, p < 0.02) between mucin concentration and the ejection fraction at 45 min after the test meal. Conclusions: The motility of the gallbladder appears to be unrelated to the viscosity of gallbladder bile or gallbladder bile composition. The negative correlation between the ejection fraction of the gallbladder and mucin concentration of gallbladder bile suggests that chronic inflammation of the gallbladder wall is associated with both an impaired motility of the gallbladder and increased mucin release into gallbladder bile. Copyright (C) 2009 S. Karger AG, Base
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