The importance of individual heterogeneity in the decomposition of measures of socioeconomic inequality in health: An approach based on quantile regression

This paper shows how recently developed regression-based methods for the decomposition of health inequality can be extended to incorporate individual heterogeneity in the responses of health to the explanatory variables. We illustrate our method with an application to the Canadian NPHS of 1994. Our strategy for the estimation of heterogeneous responses is based on the quantile regression model. The results suggest that there is an important degree of heterogeneity in the association of health to explanatory variables which, in turn, accounts for a substantial percentage of inequality in observed health. A particularly interesting finding is that the marginal response of health to income is zero for healthy individuals but positive and significant for unhealthy individuals. The heterogeneity in the income response reduces both overall health inequality and income related health inequality.Health inequalities, unobserved heterogeneity, quantile regression

Enclosing a moving target with an optimally rotated and scaled multiagent pattern

We propose a novel control method to enclose a moving target in a two-dimensional setting with a team of agents forming a prescribed geometric pattern. The approach optimises a measure of the overall agent motion costs, via the minimisation of a suitably defined cost function encapsulating the pattern rotation and scaling. We propose two control laws which use global information and make the agents exponentially converge to the prescribed formation with an optimal scale that remains constant, while the team's centroid tracks the target. One control law results in a multiagent pattern that keeps a constant orientation in the workspace; for the other, the pattern rotates with constant speed. These behaviours, whose optimality and steadiness are very relevant for the task addressed, occur independently from the target's velocity. Moreover, the methodology does not require distance measurements, common coordinate references, or communications. We also present formal guarantees of collision avoidance for the proposed approach. Illustrative simulation examples are provided

Robust stability analysis of formation control in local frames under time-varying delays and actuator faults

This paper investigates the robust stability of a multiagent system moving to a desired rigid formation in presence of unknown time-varying communication delays and actuator faults. Each agent uses relative position measurements to implement the proposed control method, which does not require common coordinate references. However, the presence of time delays in the measurements, which is inherent to the communication links between agents, has a negative impact in the control system performance leading, in some cases, to instability. Furthermore, the robust stability analysis becomes more complex if failures on actuators are taken into account. In addition, delays may be subject to time variations, depending on network load, availability of communication resources, dynamic routing protocols, or other environmental conditions. To cope with these problems, a sufficient condition based on Linear Matrix Inequalities (LMI) is provided to ensure the robust asymptotic convergence of the agents to the desired formation. This condition is valid for any arbitrarily fast time-varying delays and actuator faults, given a worst-case point-to-point delay. Finally, simulation results show the performance of the proposed approach

Computing the Global Irradiation over the Plane of Photovoltaic Arrays: A Step-by-Step Methodology

The quality of solar resource data is critical for the economic and technical assessment of solar photovoltaic (PV) installations. Understanding uncertainty and managing weather-related risk are essential for successful planning and operating of solar electricity assets. The input information available for PV designers is usually restricted to 12 monthly mean values of global horizontal irradiation (GHI) and average temperature, which characterize solar climate of locations. However, for calculating the energy production of a photovoltaic system, the global irradiation over the plane of the PV array is necessary. For this reason, this book chapter presents a methodology to appropriately determine the global irradiation over the plane of photovoltaic arrays. The methodology describes step by step the necessary equations for processing the data. Examples with numerical results are included to better show the data processing

Methodology for Sizing Hybrid Battery-Backed Power Generation Systems in Off-Grid Areas

In developing countries, rural electrification in areas with limited or no access to grid connection is one of the most challenging issues for governments. These areas are partially integrated with the electrical grid. This poor electricity distribution is mainly due to geographical inaccessibility, rugged terrains, lack of electrical infrastructure, and high required economic investment for installing large grid-connected power lines over long distances to provide electricity for regions with a low population. On the other hand, rapid depletion of fossil fuel resources on a global scale and progressive increase of energy demand and fuel price are other motives to reduce the reliance on fossil fuels. Hybrid renewable energy system (HRES) can be a suitable option for such remote areas. The objective of this chapter is to develop a methodology for sizing hybrid power generation systems (solar-diesel), battery-backed in non-interconnected zones, which minimizes the total cost and maximizes the reliability of supply using particle swarm optimization (PSO). The proposed methodology assists the sizing and designing process of an HRES for an off-grid area minimizing the cost of energy (COE) and maximizing the reliability of the system. Economic incentives offered by the Colombian government are considered in the model

Shifts in the suitable habitat available for brown trout (Salmo trutta L.) under short-term climate change scenarios

The impact of climate change on the habitat suitability for large brown trout (Salmo trutta L.) was studied in a segment of the Cabriel River (Iberian Peninsula). The future flow and water temperature patterns were simulated at a daily time step with M5 models' trees (NSE of 0.78 and 0.97 respectively) for two short-term scenarios (2011 2040) under the representative concentration pathways (RCP 4.5 and 8.5). An ensemble of five strongly regularized machine learning techniques (generalized additive models, multilayer perceptron ensembles, random forests, support vector machines and fuzzy rule base systems) was used to model the microhabitat suitability (depth, velocity and substrate) during summertime and to evaluate several flows simulated with River2D©. The simulated flow rate and water temperature were combined with the microhabitat assessment to infer bivariate habitat duration curves (BHDCs) under historical conditions and climate change scenarios using either the weighted usable area (WUA) or the Boolean-based suitable area (SA). The forecasts for both scenarios jointly predicted a significant reduction in the flow rate and an increase in water temperature (mean rate of change of ca. −25% and +4% respectively). The five techniques converged on the modelled suitability and habitat preferences; large brown trout selected relatively high flow velocity, large depth and coarse substrate. However, the model developed with support vector machines presented a significantly trimmed output range (max.: 0.38), and thus its predictions were banned from the WUA-based analyses. The BHDCs based on the WUA and the SA broadly matched, indicating an increase in the number of days with less suitable habitat available (WUA and SA) and/or with higher water temperature (trout will endure impoverished environmental conditions ca. 82% of the days). Finally, our results suggested the potential extirpation of the species from the study site during short time spans.The study has been partially funded by the IMPADAPT project (CGL2013-48424-C2-1-R) - Spanish MINECO (Ministerio de Economia y Competitividad) - and FEDER funds and by the Confederacion Hidrografica del Jucar (Spanish Ministry of Agriculture, Food and Environment). We are grateful to the colleagues who worked in the field and in the preliminary data analyses, especially Juan Diego Alcaraz-Henandez, David Argibay, Aina Hernandez and Marta Bargay. Thanks to Matthew J. Cashman for the academic review of English. Finally, the authors would also to thank the Direccion General del Agua and INFRAECO for the cession of the trout data. The authors thank AEMET and UC by the data provided for this work (dataset Spain02).Muñoz Mas, R.; López Nicolás, AF.; Martinez-Capel, F.; Pulido-Velazquez, M. (2016). Shifts in the suitable habitat available for brown trout (Salmo trutta L.) under short-term climate change scenarios. Science of the Total Environment. 544:686-700. https://doi.org/10.1016/j.scitotenv.2015.11.14768670054

Socio-Cultural Differences in Social Exclusion

Received 28 April 2018. Accepted 30 May 2018. Published online 1 July 2018.The main object of this research is to describe social exclusion in a comparative world perspective. Social exclusion is a main concern worldwide. Non-desirable social groups as neighbours are used as a proxy measure to answer three questions: who are the most excluded social groups, who are the excluders, and what are the main explanatory variables of social exclusion. Social exclusion, as a multidimensional phenomenon, is defined in relation to concepts such as stigma, discrimination, and prejudice. Social, economic, political and ideological-religious attitudes are used to construct the profile of the excluder. Social exclusion has been measured through three indexes of social exclusion, personal, group and total exclusion, since a main component analysis demonstrated that the degree of social exclusion varied depending on whether the excluded group was more or less based on personal decisions on one’s behaviour taken by the individual. Based on theory and previous research, four main variables have been tested to explain social exclusion: social position, exposure to information, post-materialist values and perception of security. But other explanatory variables were also added to the analysis. EVS and WVS databases (from 1981 to 2014) have been used, though most of the analysis has been based on the last WVS- 6th wave on 59 countries with a total of more than 85,000 interviews

Resolución quirúrgica de la colecistitis aguda. ¿Influye el tiempo de evolución?

ResumenIntroducciónLa colecistectomía laparoscópica precoz es nuestra conducta para el tratamiento de la colecistitis aguda; sin embargo, la consulta tardía y el tratamiento postergado por dificultades de acceso hacen que el tiempo de resolución muchas veces sobrepase los 7 días de iniciados los síntomas.Nuestro objetivo es comparar los resultados quirúrgicos entre los pacientes operados antes y después de este periodo.Material y métodosSerie de casos consecutivos de pacientes con diagnóstico de colecistitis aguda operados entre junio de 2013 y diciembre de 2014 en el Servicio de Cirugía del Hospital de Coquimbo. De 358 casos, se excluyen aquellos asociados a colangitis, pancreatitis aguda, ASA ≥4 y cuadro mayor de 30 días. Consecuentemente se incluyen 233 pacientes que se dividen en «grupo precoz» (GP), operados antes del séptimo día de iniciados los síntomas, y «grupo tardío» (GT), operados después de este periodo. Se analizan la presentación de la serie y la asociación entre variables cualitativas y cuantitativas mediante la prueba de χ2 y t de Student, respectivamente.ResultadosEl GP presenta una estadía hospitalaria de 3,9 (±2,0) días y el GT de 7,2 (±5,2), (p=0,0001); el periodo postoperatorio es de 1,9 (±1,6) y de 2,9 (±4,4) días, respectivamente (p=0,055). La tasa de conversión en el GP es del 2,1% y en el GT del 9,7% (p=0,027); la tasa global de complicaciones postoperatorias es del 3,2 y 10,7%, respectivamente (p=0,033).DiscusiónNuestros resultados respaldan la colecistectomía precoz en pacientes con colecistitis aguda. Se pone de manifiesto un problema de gestión, en que la postergación de la resolución quirúrgica empeora los resultados y conlleva mayor riesgo de complicaciones.AbstractIntroductionThe treatment for acute Cholecystitis should be an early Laparoscopic Cholecystectomy. However, this resolution often exceed 7 days after the clinical symptoms onset. Mainly, for delayed consultation of the patients, access difficulties and delayed surgical resolution in our hospital.The aim is compare the surgical outcomes of patients that have had a Cholecystectomy before 7 days after the clinical symptoms onset with those operated after this period.Material and methodsBetween June 2013 and December 2014, 358 patients were Cholecystectomy for acute Cholecystitis at the Hospital of Coquimbo. Those associated to Cholangitis, Acute Pancreatitis, ASA ≥4 and Gallbladder Cancer, were excluded; 233 patients were included. They were allocated into two groups according to the treatment timeframe: ‘Early Group’ (EG) for those operated before the seventh day of symptoms onset and ‘Late Group’ (LG) for those operated after this period. A retrospective study was used to collect data demographics, clinical and surgical outcomes. All these factors were compared between the two groups.ResultsThe EG had a hospital stay of 3.9 (±2.0) days and the LG 7.2 (±5.2) (P=.0001); the postoperative stay was 1.9 (±1.6) and 2.9 (±4.4) (P=.055) days, respectively. The conversion rate in the EG was 2.1% and 9.7% in the LT (P=.027); the overall rate of postoperative complications was 3.2% and 10.7% (P=.033), respectively.ConclusionsThe findings support an early Cholecystectomy in patients with acute cholecystitis. There is a management problem in terms of delayed surgical resolution which worsens surgical outcomes and increase morbidity