Robust optimization of valve management to improve water quality in WDNs under demand uncertainty

ABSTRACTWater quality deterioration in water distribution networks can be associated with high water residence time in the network. To this end, some previous studies have proposed optimization procedures for valve management. However, these studies generally come up with operational configurations assuming deterministic user demand patterns that may never occur in reality. In consequence, the proposed solutions may not be effective for improving water quality or do not comply with pressure constraints if different demand patterns are observed. This study proposes a methodology to determine robust configurations of the valves to keep water residence time at acceptable levels regardless of the variability in demand patterns. The methodology is tested on four different distribution systems of varying topology and size. Results show the importance of executing robust – instead of deterministic, optimization to find valve configurations that guarantee the performance of the networks in terms of hydraulics and..

Multi-objective valve management optimization formulations for water quality enhancement in WDNs.

Water distribution networks (WDNs) need to guarantee that water is delivered with adequate quality. This paper compares the performance of 12 multiobjective procedures to limit water quality deterioration in a WDN through the optimal operation of valves. The first objective (ObF1) is to minimize the water age, chosen as a surrogate parameter of quality deterioration, and the second objective (ObF2) is to minimize the number of valve closures. The 12 procedures are derived from the combination of 4 different optimization algorithms and 3 formulations of ObF1, namely, to minimize the maximum, the arithmetic mean, and the demand-weighted mean water age. The optimization algorithms considered are random search (RS), Loop for Optimal Valve Status Configuration (LOC), and a combination of each of these two with the Archive-based Micro Genetic Algorithm. The procedures are tested on two networks of different complexity. Results show how LOC is able to find near-optimal solutions using a fraction of the computational time required by a brute force search. Furthermore, among the ObF1 formulations, the use of the averages (either arithmetic or demand-weighted) gives better results in terms of impact on the population served by a WDN

Vinculación entre extensión, investigación y docencia a partir del trabajo en red en promoción de la salud

Networking is an articulation and exchange strategy between institutions that decide to bond and associate efforts, experiences and knowledge to reach common objectives. The participation of teachers of the School of Veterinary Sciences of the National University of La Pampa in networks with representatives of the health and education sectors, municipal organisms and NGOs, among others, allowed to generate different extension proposals based on health promotion. Dialogue, communication and construction spaces were created between the university and the community. The objective of this article is to describe linkage activities between the School above mentioned and the community through networking in health promotion. Fifty two meetings in different regions took place and fifty five community activities were organized, which included thirty eight workshops aimed at different actors of the educational community, elders, pregnant women, and public in general and seventeen training activities, seminars, informative talks, active waiting rooms and scientific-technological publication. Different didactic materials were elaborated. Through the socio-environmental problems detected, three research projects were designed. This type of proposals based on networking and health promotion offer an opportunity to higher level institutions to develop their social function. Furthermore, they help teaching, research and extension articulationEl trabajo en red es una estrategia de articulación e intercambio entre instituciones que deciden vincularse y asociar sus esfuerzos, experiencias y conocimientos para el logro de fines comunes. La participación de docentes de la Facultad de Ciencias Veterinarias de la UNLPam en redes conformadas por representantes del sector salud, educación, organismos municipales, ONG, entre otros; permitió generar distintas propuestas de extensión basadas en la promoción de la salud. Se crearon espacios de diálogo, comunicación y construcción de conocimiento entre la universidad y la comunidad. El objetivo de este artículo es describir las actividades de vinculación entre la Facultad de Cs. Veterinarias de la UNLPam y la comunidad a partir del trabajo en red en promoción de la salud. Se participó en 52 reuniones intersectoriales y se realizaron un total de 55 actividades comunitarias, las que incluyeron38 talleres destinados a distintos actores de la comunidad educativa, adultos mayores, embarazadas, público en general y 17 actividades de capacitaciones, seminario, charla informativa, salas de espera activa y divulgación científico-tecnológica. Se elaboraron distintos materiales didácticos A partir de las problemáticas socio-ambientales detectadas, se generaron 3 proyectos de investigación. Este tipo de propuestas basadas en el trabajo en red y en la promoción de la salud ofrecen una oportunidad para que las instituciones de nivel superior desempeñen su función social. Además favorecen la articulación entre la docencia, investigación y extensión DOI:http://dx.doi.org/10.19137/cienvet2013-1511

Advancing robust multi-objective optimisation applied to complex model-based water-related problems

The exercise of solving engineering problems that require optimisation procedures can be seriously affected by uncertain variables, resulting in potential underperforming solutions. Although this is a well-known problem, important knowledge gaps are still to be addressed. For example, concepts of robustness largely differ from study to study, robust solutions are generally provided with limited information about their uncertainty, and robust optimisation is difficult to apply as it is a computationally demanding task. The proposed research aims to address the mentioned challenges and focuses on robust optimisation of multiple objectives and multiple sources of probabilistically described uncertainty. This is done by the development of the Robust Optimisation and Probabilistic Analysis of Robustness algorithm (ROPAR), which integrates widely accepted robustness metrics into a single flexible framework. In this thesis, ROPAR is not only tested in benchmark functions, but also in engineering problems related to the water sector, in particular the design of urban drainage and water distribution systems. ROPAR allows for employing practically any existing multi-objective optimisation algorithm as its internal optimisation engine, which enables its applicability to other problems as well. Additionally, ROPAR can be straightforwardly parallelized, allowing for fast availability of results

CCWI2017: F83 'Operational interventions in WDS to improve water quality: a comparison of multi-objective optimization formulations'

Managing water quality in drinking water distribution systems is very important to guarantee consumers’ health. Disinfection is used to reduce the risk of pathogenic contamination or microbial species proliferation. Chlorine is a disinfection substance that is traditionally used due to its effectiveness and low cost. However, the use of chlorine has related disinfection by-products, some of which can have carcinogenic effects on human health (e.g., trihalomethanes, THMs). In this context, the objective of this paper is to compare different multi-objective optimization problem formulations to improve the operational interventions of WDSs, in order to reduce the formation of THMs in the network. The analysis of two case studies shows that operating valves is more convenient than operating hydrants and pumps in most of the proposed formulations

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field