364 research outputs found
Ecology of antimicrobial resistance: humans, animals, food and environment
Antimicrobial resistance is a major health problem. After decades of research, numerous difficulties in tacklingresistance have emerged, from the paucity of new antimicrobials to the inefficient contingency plans to reduce the use ofantimicrobials; consequently, resistance to these drugs is out of control. Today we know that bacteria from the environmentare often at the very origin of the acquired resistance determinants found in hospitals worldwide. Here we define the geneticcomponents that flow from the environment to pathogenic bacteria and thereby confer a quantum increase in resistance levels,as resistance units (RU). Environmental bacteria as well as microbiomes from humans, animals, and food represent aninfinite reservoir of RU, which are based on genes that have had, or not, a resistance function in their original bacterial hosts.This brief review presents our current knowledge of antimicrobial resistance and its consequences, with special focus on theimportance of an ecologic perspective of antimicrobial resistance. This discipline encompasses the study of the relationshipsof entities and events in the framework of curing and preventing disease, a definition that takes into account both microbialecology and antimicrobial resistance. Understanding the flux of RU throughout the diverse ecosystems is crucial to assess,prevent and eventually predict emerging scaffolds before they colonize health institutions. Collaborative horizontal researchscenarios should be envisaged and involve all actors working with humans, animals, food and the environment. [IntMicrobiol 2012; 15(3):101-109
Ecology of antimicrobial resistance: humans, animals, food and environment
Antimicrobial resistance is a major health problem. After decades of research, numerous difficulties in tackling resistance have emerged, from the paucity of new antimicrobials to the inefficient contingency plans to reduce the use of antimicrobials; consequently, resistance to these drugs is out of control. Today we know that bacteria from the environment are often at the very origin of the acquired resistance determinants found in hospitals worldwide. Here we define the genetic components that flow from the environment to pathogenic bacteria and thereby confer a quantum increase in resistance levels, as resistance units (RU). Environmental bacteria as well as microbiomes from humans, animals, and food represent an infinite reservoir of RU, which are based on genes that have had, or not, a resistance function in their original bacterial hosts. This brief review presents our current knowledge of antimicrobial resistance and its consequences, with special focus on the importance of an ecologic perspective of antimicrobial resistance. This discipline encompasses the study of the relationships of entities and events in the framework of curing and preventing disease, a definition that takes into account both microbial ecology and antimicrobial resistance. Understanding the flux of RU throughout the diverse ecosystems is crucial to assess, prevent and eventually predict emerging scaffolds before they colonize health institutions. Collaborative horizontal research scenarios should be envisaged and involve all actors working with humans, animals, food and the environment
Deployment of Digital Video and Audio Over Electrical SCADA Networks
With the arrival of new hardware and software technologies,
supervisory control and data acquisition human-machine
interfaces (SCADA/HMI), usually text-based, can now benefit
from the advantages the inclusion of multimedia information
brings. However, due to the special requirements imposed by
such systems, integrating audio and video data into the SCADA
interfaces is not a trivial task. In this document we analyze those
special characteristics and propose solutions so this integration is
possible in power systems communication.Ministerio de Ciencia y Tecnología TIC2000-0367-P4-0
Scaling of a standardized summary test (RESUMeV) for two primary school grades
El objetivo del estudio fue el de mostrar evidencias de fiabilidad y validez para una prueba de resúmenes (RESUMev) que evalúa el grado de comprensión lectora en alumnos de cuarto y sexto de primaria. Participaron un total de 528 estudiantes de primaria, de los cuales 236 fueron estudiantes de 4º de primaria (9 y 10 años) y 292 a 6º de primaria (11 a 13 años). Todos estos alumnos procedían de 21 centros escolares. Para evaluar la consistencia interna, se calculó el alfa de Cronbach en los criterios de evaluación de resúmenes (contenido, coherencia y estilo) y su índice de homogeneidad (Hj). La validez se evaluó mediante la comparación entre niveles académicos. En cuanto a los resultados, se obtuvieron índices elevados significativos de fiabilidad y de validez. Los resultados proporcionan evidencia empírica para la validez de la pruebaThe purpose of this work was to collect construct and criterion-related evidence of validity for a summary test (RESUMeV) designed to assess students from fourth and sixth grade. The sample of this study consisted of 528 children, 236 from fourth grade and 296 from sixth grade. They were drawn from 21 different primary schools. Several criteria were used. To evaluate the internal consistency, Cronbach’s alpha was calculated for all summary evaluation criteria (content, coherence, and style); a homogeneity index (Hj) was calculated too. The validity was evaluated by comparing academic levels. As for the results, both
reliability and validity indices were high and significant. These results provide empirical evidence for the validity of the summary testEste trabajo ha sido subvencionado por el MINNECO PSI2013 47219-
A critical-path based iterated local search for the green permutation flowshop problem
The permutation flowshop scheduling problem is a widely studied combinatorial optimization problem with
several real-world applications. In this paper we address a green variant of the problem with controllable processing times and two objective functions: one related to the service level of the factory (makespan) and another
one related to the total cost or the total energy/carbon consumption. For this problem we propose a novel
Critical-Path based Iterated Local Search. This metaheuristic incorporates several theoretical results to accelerate
the search of solutions in the intensification phase. The proposed algorithm has been compared on an extensive
benchmark with the most promising algorithms in the literature. The computational results show the excellent
performance of the proposal.Ministerio de Ciencia e Innovación PID2019-108756RB-I00Junta de Andalucía US-126451
Multi-Sensor Accurate Forklift Location and Tracking Simulation in Industrial Indoor Environments
[Abstract] Location and tracking needs are becoming more prominent in industrial environments nowadays. Process optimization, traceability or safety are some of the topics where a positioning system can operate to improve and increase the productivity of a factory or warehouse. Among the different options, solutions based on ultra-wideband (UWB) have emerged during recent years as a good choice to obtain highly accurate estimations in indoor scenarios. However, the typical harsh wireless channel conditions found inside industrial environments, together with interferences caused by workers and machinery, constitute a challenge for this kind of system. This paper describes a real industrial problem (location and tracking of forklift trucks) that requires precise internal positioning and presents a study on the feasibility of meeting this challenge using UWB technology. To this end, a simulator of this technology was created based on UWB measurements from a set of real sensors. This simulator was used together with a location algorithm and a physical model of the forklift to obtain estimations of position in different scenarios with different obstacles. Together with the simulated UWB sensor, an additional inertial sensor and optical sensor were modeled in order to test its effect on supporting the location based on UWB. All the software created for this work is published under an open-source license and is publicly available.Xunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/01Agencia Estatal de Investigación de España; TEC2016-75067-C4-1-
Environmental Cross-Validation of NLOS Machine Learning Classification/Mitigation with Low-Cost UWB Positioning Systems
[Abstract] Indoor positioning systems based on radio frequency inherently present multipath-related phenomena. This causes ranging systems such as ultra-wideband (UWB) to lose accuracy when detecting secondary propagation paths between two devices. If a positioning algorithm uses ranging measurements without considering these phenomena, it will face critical errors in estimating the position. This work analyzes the performance obtained in a localization system when combining location algorithms with machine learning techniques applied to a previous classification and mitigation of the propagation effects. For this purpose, real-world cross-scenarios are considered, where the data extracted from low-cost UWB devices for training the algorithms come from a scenario different from that considered for the test. The experimental results reveal that machine learning (ML) techniques are suitable for detecting non-line-of-sight (NLOS) ranging values in this situation.Xunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/01Agencia Estatal de Investigación de España; TEC2016-75067-C4-1-
NLOS Identification and Mitigation Using Low-Cost UWB Devices
[Abstract] Indoor location systems based on ultra-wideband (UWB) technology have become very popular in recent years following the introduction of a number of low-cost devices on the market capable of providing accurate distance measurements. Although promising, UWB devices also suffer from the classic problems found when working in indoor scenarios, especially when there is no a clear line-of-sight (LOS) between the emitter and the receiver, causing the estimation error to increase up to several meters. In this work, machine learning (ML) techniques are employed to analyze several sets of real UWB measurements, captured in different scenarios, to try to identify the measurements facing non-line-of-sight (NLOS) propagation condition. Additionally, an ulterior process is carried out to mitigate the deviation of these measurements from the actual distance value between the devices. The results show that ML techniques are suitable to identify NLOS propagation conditions and also to mitigate the error of the estimates when there is LOS between the emitter and the receiver.Xunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/01Agencia Estatal de Investigación de España; TEC2016-75067-C4-1-
The effects of type of discourse and of a second language on comprehension processes : a new linguistic relativism?
A través de este trabajo se examinan diversas cuestiones relacionadas con los procesos de comprensión del discurso escrito y de la adquisición de segundas lenguas como el español, inglés o portugués. El objetivo fundamental de este artículo es tratar de desvelar si el procesamiento que realiza el lector durante la comprensión de un discurso determinado o ante la adquisición de una segunda lengua requiere de una actividad cognitiva diferente a cuando se trata de comprender otro de naturaleza diferente o bajo una lengua diferente. Para ello se analiza por un lado, las diferencias existentes entre diferentes tipos de texto, centrándonos fundamentalmente en el narrativo y el expositivo, analizando sus repercusiones sobre varios niveles de la cognición humana. Por otro, se analizan algunos estudios sobre la adquisición de diferentes segundas lenguas y sus repercusiones sobre su nivel de activación cerebral utilizando la técnica de fMRI. Por último, se plantea hasta qué punto el relativismo lingüístico influye en los procesos de comprensión y de la realización de inferencias y de la adquisición de una segunda lengua.In this paper we address issues related to comprehension processes, and how they can be affected by types of text or written discourse, and by a reader’s first or second language. To this end, we discuss the processing of narrative and expository texts, and their effects on different levels of human cognition. Likewise, we discuss the effects of texts written in different codes, that is, in first and second languages. We propose that differences in text comprehension processes occur as a function of their causal nature and of the inferences that are generated during comprehension. In terms of second language comprehension, modern research applying functional magnetic resonance imaging, or fMRI, with bilinguals is discussed in support of the notion that first language comprehension processes are generally replicated in the second language. Therefore, we focus on comprehension processes, generation of interferences, and the processing of a second language as influenced by linguistic relativism
Persistence of instanton connections in chemical reactions with time dependent rates
The evolution of a system of chemical reactions can be studied, in the
eikonal approximation, by means of a Hamiltonian dynamical system. The fixed
points of this dynamical system represent the different states in which the
chemical system can be found, and the connections among them represent
instantons or optimal paths linking these states. We study the relation between
the phase portrait of the Hamiltonian system representing a set of chemical
reactions with constant rates and the corresponding system when these rates
vary in time. We show that the topology of the phase space is robust for small
time-dependent perturbations in concrete examples and state general results
when possible. This robustness allows us to apply some of the conclusions on
the qualitative behavior of the autonomous system to the time-dependent
situation
- …