1,208 research outputs found
Factors Influencing Revenue Collection for Preventative Maintenance of Community Water Systems: A Fuzzy-Set Qualitative Comparative Analysis
This study analyzed combinations of conditions that influence regular payments for water service in resource-limited communities. To do so, the study investigated 16 communities participating in a new preventive maintenance program in the Kamuli District of Uganda under a public–private partnership framework. First, this study identified conditions posited as important for collective payment compliance from a literature review. Then, drawing from data included in a water source report and by conducting semi-structured interviews with households and water user committees (WUC), we identified communities that were compliant with, or suspended from, preventative maintenance service payments. Through qualitative analyses of these data and case knowledge, we identified and characterized conditions that appeared to contribute to these outcomes. Then, we employed fuzzy-set qualitative comparative analysis (fsQCA) to determine the combinations of conditions that led to payment compliance. Overall, the findings from this study reveal distinct pathways of conditions that impact payment compliance and reflect the multifaceted nature of water point sustainability. Practically, the findings identify the processes needed for successful payment compliance, which include a strong WUC with proper support and training, user perceptions that the water quality is high and available in adequate quantities, ongoing support, and a lack of nearby water sources. A comprehensive understanding of the combined factors that lead to payment compliance can improve future preventative maintenance programs, guide the design of water service arrangements, and ultimately increase water service sustainability
Body Condition Scoring for Horses
Horse enthusiasts are often concerned about their horse’s health, appearance and performance. A major key to accomplishing these three goals is to keep your horse at a desirable body condition, or degree of fat cover. However, being able to accurately evaluate a horse to tell if they are over or underweight has been a subjective practice for many years. As with all aspects of horse ownership, horse owners have different opinions on what is an ideal body weight for an individual horse. Also, because horses come in all shapes and sizes, many horse owners are not able to objectively evaluate the body condition of their horse. This fact sheet describes the Henneke Body Condition Scoring syste
Synthesis of Two Key Fragments of the Complex Polyhalogenated Marine Meroterpenoid Azamerone
A concise route toward two advanced fragments in the context of the total synthesis of the unique natural product azamerone is reported. Key synthetic features include the enantioselective synthesis of an epoxysilane and its Lewis-acid-induced cyclization and the installation of the pyridazine ring via a formylation/condensation sequence. This route provides strategic insights into the chemistry of phthalazinediols, facilitating synthetic approaches toward this class of natural products
The Furan Shuffling Hypothesis: A Biogenetic Proposal for Eremophilane Sesquiterpenoids
Based on the structural similarities of the recently isolated eremophilane‐type sesquiterpenoids microsphaeropsisin B and C and the iso‐eremophilane periconianone C, a revised biogenetic hypothesis for C8–C11‐connected iso‐eremophilanes is presented and corroborated by strong experimental evidence. The first enantioselective total syntheses of microsphaeropsisin B and C were achieved starting from a known intermediate, whose synthesis was elaborated previously in the total synthesis of periconianone A, and in a total of 15 steps starting from γ‐hydroxy carvone. Mild reaction conditions for the subsequent α‐ketol rearrangement not only resulted in the herein proposed conversion of microsphaeropsisin B into periconianone C, but also in the conversion of microsphaeropsisin C into 4‐epi‐periconianone C
FE An efficient data-driven multiscale approach based on physics-constrained neural networks and automated data mining
Herein, we present a new data-driven multiscale framework called
FE which is based on two main keystones: the usage of
physics-constrained artificial neural networks (ANNs) as macroscopic surrogate
models and an autonomous data mining process. Our approach allows the efficient
simulation of materials with complex underlying microstructures which reveal an
overall anisotropic and nonlinear behavior on the macroscale. Thereby, we
restrict ourselves to finite strain hyperelasticity problems for now. By using
a set of problem specific invariants as the input of the ANN and the Helmholtz
free energy density as the output, several physical principles, e.g.,
objectivity, material symmetry, compatibility with the balance of angular
momentum and thermodynamic consistency are fulfilled a priori. The necessary
data for the training of the ANN-based surrogate model, i.e., macroscopic
deformations and corresponding stresses, are collected via computational
homogenization of representative volume elements (RVEs). Thereby, the core
feature of the approach is given by a completely autonomous mining of the
required data set within an overall loop. In each iteration of the loop, new
data are generated by gathering the macroscopic deformation states from the
macroscopic finite element (FE) simulation and a subsequently sorting by using
the anisotropy class of the considered material. Finally, all unknown
deformations are prescribed in the RVE simulation to get the corresponding
stresses and thus to extend the data set. The proposed framework consequently
allows to reduce the number of time-consuming microscale simulations to a
minimum. It is exemplarily applied to several descriptive examples, where a
fiber reinforced composite with a highly nonlinear Ogden-type behavior of the
individual components is considered
System Approaches to Water, Sanitation, and Hygiene: A Systematic Literature Review
Endemic issues of sustainability in the water, sanitation, and hygiene (WASH) sector have led to the rapid expansion of ‘system approaches’ for assessing the multitude of interconnected factors that affect WASH outcomes. However, the sector lacks a systematic analysis and characterization of the knowledge base for systems approaches, in particular how and where they are being implemented and what outcomes have resulted from their application. To address this need, we conducted a wide-ranging systematic literature review of systems approaches for WASH across peer-reviewed, grey, and organizational literature. Our results show a myriad of methods, scopes, and applications within the sector, but an inadequate level of information in the literature to evaluate the utility and efficacy of systems approaches for improving WASH service sustainability. Based on this analysis, we propose four recommendations for improving the evidence base including: diversifying methods that explicitly evaluate interconnections between factors within WASH systems; expanding geopolitical applications; improving reporting on resources required to implement given approaches; and enhancing documentation of effects of systems approaches on WASH services. Overall, these findings provide a robust survey of the existing landscape of systems approaches for WASH and propose a path for future research in this emerging field
System Dynamics Modelling as a Tool for Assessing Rural Water Sustainability
System dynamics modelling is a tool that has been used for decades in business management and economics applications, but little focus has been applied to the WASH sector.
Specifically, this paper discusses the use of causal loop diagrams and stock flow diagrams as methods to better understand the systemic drivers affecting sustainability of rural water service delivery
A serological and bacteriological survey of brucellosis in wild boar (Sus scrofa) in Belgium
Brucellosis is frequently reported among wild boar populations in Europe. The aim of the study was to assess the epidemiological situation in Belgium, regarding the steady increase of wild boar populations over the last decades. Several serological tests were used and compared with culture and IS711 polymerase chain reaction (PCR), to determine the most suitable combination of diagnostic tools for conducting a successful prevalence study in wildlif
Cross-Coupling Reactions of Monosubstituted Tetrazines
A Ag-mediated Pd-catalyzed cross-coupling method for 3-bromo-1,2,4,5-tetrazine with boronic acids is presented. Electronic modification of the 1,1′-bis(diphenylphosphine)ferrocene (dppf) ligand was found to be crucial for good turnover. Using this fast method, a variety of alkyl-, heteroatom-, and halide-substituted aryl- and heteroaryl-tetrazines were prepared (29 examples, up to 87% yield)
Understanding Rural Water Services as a Complex System: An Assessment of Key Factors as Potential Leverage Points for Improved Service Sustainability
Rural water supply services worldwide consistently fail to deliver full public health impacts as intended due to a low service sustainability. This failure is increasingly attributed to weak local systems composed of social, financial and environmental factors. Current approaches in the water, sanitation and hygiene (WASH) sector for understanding and improving these systems typically focus on the strength and capacity of these factors, but not the interactions between them. We contend that these approaches overlook the inherent complexity and context-specific nature of each local system. To assess this complexity, we conducted four participatory factor mapping workshops with local stakeholders across multiple rural water contexts to identify the factors and interactions that support service sustainability. We then evaluate the potential for factors to act as strategic leverage points based on influence, dependence and feedback metrics that arise from their interactions with other factors. We find that while participants across the contexts tend to identify a common set of factors, the interactions amongst those factors and their individual ability to influence service sustainability varies considerably across contexts. These findings suggest that a more intentional focus on factor interactions inWASH systems could lead to more effective strategies for improving service sustainability
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