245 research outputs found

    On the parallelization of a three-parametric log-logistic estimation algorithm

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    Networked telerobots transmit data from its sensors to the remote controller. To provide guarantees on the time requirements of these systems it is mandatory to keep the transmission time delays below a given threshold, and to that end we should predict them. In this paper we tackle the parallelization of a procedure that models these stochastic time delays. More precisely, we focus on fitting the time delay signal using a three-parametrical log-logistic distribution. Since, the robot and the controller are powered by multicore processors and, mainly on the robot, the energy consumption is a relevant issue, we study different alternatives to optimize both performance and energy usage of the aforesaid algorithm. Two quad-core processors are considered: a low power Intel Core i7 (45W TDP) and a ultra low power Samsung Exynos 5 (6W TDP). Results show that parallelism is beneficial, but that not all the cores should be exploited if the system is targeted at optimizing a performance-energy tradeoff.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Integration of Facial Expression and Gaze Direction in Individuals with a High Level of Autistic Traits

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    This work was supported by the Spanish Ministry of Economy, Industry, and Competitiveness, through research project PID2020-114790GB-I00 to J.L., and by the Andalusian Council and European Regional Development Fund, through research project B-SEJ-572-UGR20 to A.M. B.A.-M. was supported by a predoctoral fellowship from the FPU program from the Spanish Ministry of Science and Education (FPU16/07124).Background.We investigated whether individuals with high levels of autistic traits integrate relevant communicative signals, such as facial expression, when decoding eye-gaze direction. Methods. Students with high vs. low scores on the Autism Spectrum Quotient (AQ) performed a task in which they responded to the eye directions of faces, presented on the left or the right side of a screen, portraying different emotional expressions. Results. In both groups, the identification of gaze direction was faster when the eyes were directed towards the center of the scene. However, in the low AQ group, this effect was larger for happy faces than for neutral faces or faces showing other emotional expressions, whereas participants from high AQ group were not affected by emotional expressions. Conclusions. These results suggest that individuals with more autistic traits may not integrate multiple communicative signals based on their emotional value.Spanish Government PID2020-114790GB-I00Andalusian CouncilEuropean Commission B-SEJ-572-UGR20German Research Foundation (DFG) FPU16/0712

    Hierarchical regulation of sensor data transmission for networked telerobots

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    Networked telerobots carry sensors that send data, with stochastic transmission times, to a remote human operator, who must execute some real-time control task (e.g., navigation). In this paper we propose to regulate the sensory information being transmitted in order to guarantee soft real-time requirements and also optimize the quality of control, through a novel two-level hierarchical controller that both varies the amount of transmitted sensor data and dynamically reconfigures active sensors. Our controller has been implemented in a web-based teleoperator interface that is highly portable (it runs on desktop PCs, tablets, smartphones, etc.) and non-invasive, i.e., requires minimal modifications in the existing components of the system, thus being suitable for many applications. Here we present our regulation methods and the results of some experiments. They demonstrate the maximization of the transmitted data while guaranteeing the real-time requirements.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Living at the Wrong Time: Effects of Unmatching Official Time in Portugal and Western Spain

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    Human circadian rhythmicity is subjected to the internal circadian clock, the sun and social clocks (official time, social/work schedules). The discrepancy among these clocks, as occurs when official time does not match its geographical time zone, may produce circadian disruption. Western Spain (GMT+1/+2) and Portugal (GMT0/+1) share similar longitudes (sun time) but have different official times. This provides a unique opportunity to evaluate the effects of official time on circadian rhythmicity and sleep in elderly and retired populations (with no remunerated duties presumed, although other social commitments may be present) at both locations. Although both populations slept enough for their age (7-8 h), circadian robustness (e.g., interdaily stability, relative amplitude) was greater in Portugal, especially during weekdays, while greater desynchronization (both body temperature vs. motor activity and body temperature vs. light exposure) tended to occur in the Spaniards. Once corrected by GMT0, meals took place later in Spain than in Portugal, especially as the day progresses, and a possible interplay between bed/meal timings and internal desynchronization was found. Our results point to the possible deleterious effect on circadian system robustness when official time is misaligned with its geographical time zone.This research was funded by the Ministry of Economy and Competitiveness, the Instituto de Salud Carlos III through a CIBERFES grant (CB16/10/00239, CB16/10/00468); Fundación General del Consejo Superior de Investigaciones Científicas through grant ModulEn (POCTEP 0348_CIE_6_E, Programa de cooperación INTERREG V-A España-Portugal) and Diabfrail LatAm (European Union Horizon 2020 research and innovation programme No. 825546) awarded to MAR (all co-financed by FEDER). Grant RTI2018-093528-B-I00, funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union” or by the “European Union NextGenerationEU/PRTR”. A research fellowship was granted to MAB-C (20401/SF/17, Fundación Séneca, Región de Murcia (Spain)).S

    Isotopic study of the influence of oxygen interaction and surface species over different catalysts on the soot removal mechanism

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    In order to improve the catalytic formulations for soot removal in after-treatment emission control technologies for gasoline and diesel engine vehicle, an isotopic study was approached using transitory labeled oxygen response method over model catalysts that allows the unraveling of soot oxidation mechanism. Ce-based materials promote oxygen exchange associated with the high population of lattice oxygen species (O2-) denoted as OI type. The incorporation of praseodymium produces a Pr3+ enrichment that decrease the energy for oxygen release and increase oxygen mobility through surface and subsurface oxygen centers (OII type) depending on the synthesis procedure. For PtBaK catalyst, OIII species are responsible for oxygen exchange. Gas-solid reaction between soot and gas phase molecular oxygen is responsible for direct uncatalyzed soot oxidation. For ceria containing catalysts, low-temperature soot removal takes place through the intervention of lattice atomic species and superoxide species. For DPNR model catalyst, PtBaK/Al2O3, the soot elimination occurs with the intervention of OIII type centers. In the presence NO, the assisted and cooperative mechanism due to NO2 and the intervention of the adsorbed nitrate species on the trimetallic catalyst enhances soot removal capacity.MCR acknowledges the postdoctoral fellowship obtained from the University of Malaga. MCR, CH, MAL and LJA want to thank the financial support of CTQ 2017-87909R project. MCR also want to thank the University of Alicante for the financial support for the internship (INV19-07). JCMM and AGG gratefully acknowledge the financial support of Generalitat Valenciana (PROMETEO/2018/076 project) and the Spanish Ministry of Science, Innovation and Universities (PID2019-105542RB-I00 project) and the UE-FEDER funding. JCMM also acknowledges Spanish Ministry of Science, Innovation and Universities for the financial support through a FPU grant (FPU17/00603)

    Regulator of calcineurin 1 (Rcan1) has a protective role in brain ischemia/reperfusion injury

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    <p>Abstract</p> <p>Background</p> <p>An increase in intracellular calcium concentration [Ca<sup>2+</sup>]<sub>i </sub>is one of the first events to take place after brain ischemia. A key [Ca<sup>2+</sup>]<sub>i</sub>-regulated signaling molecule is the phosphatase calcineurin (CN), which plays important roles in the modulation of inflammatory cascades. Here, we have analyzed the role of endogenous regulator of CN 1 (Rcan1) in response to experimental ischemic stroke induced by middle cerebral artery occlusion.</p> <p>Methods</p> <p>Animals were subjected to focal cerebral ischemia with reperfusion. To assess the role of Rcan1 after stroke, we measured infarct volume after 48 h of reperfusion in <it>Rcan1 </it>knockout (KO) and wild-type (WT) mice. <it>In vitro </it>studies were performed in astrocyte-enriched cortical primary cultures subjected to 3% oxygen (hypoxia) and glucose deprivation (HGD). Adenoviral vectors were used to analyze the effect of overexpression of Rcan1-4 protein. Protein expression was examined by immunohistochemistry and immunoblotting and expression of mRNA by quantitative real-time Reverse-Transcription Polymerase Chain Reaction (real time qRT-PCR).</p> <p>Results</p> <p>Brain ischemia/reperfusion (I/R) injury <it>in vivo </it>increased mRNA and protein expression of the calcium-inducible Rcan1 isoform (Rcan1-4). I/R-inducible expression of Rcan1 protein occurred mainly in astroglial cells, and in an <it>in vitro </it>model of ischemia, HGD treatment of primary murine astrocyte cultures induced Rcan1-4 mRNA and protein expression. Exogenous Rcan1-4 overexpression inhibited production of the inflammatory marker cyclo-oxygenase 2. Mice lacking Rcan1 had higher expression of inflammation associated genes, resulting in larger infarct volumes.</p> <p>Conclusions</p> <p>Our results support a protective role for Rcan1 during the inflammatory response to stroke, and underline the importance of the glial compartment in the inflammatory reaction that takes place after ischemia. Improved understanding of non-neuronal mechanisms in ischemic injury promises novel approaches to the treatment of acute ischemic stroke.</p

    Advanced blends as avisable extended option for thermal engines: emissions and performance on a Diesel Engine

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    The stricter emission regulation for the automobile sector to achieve reduction in pollution that caused GHG in the atmosphere, have resulted in the search of alternative clean fuels which satisfy the demand of this sector. In this context, the incorporation of bio-based oxygenated compounds can be considered as an alternative to both, contribute to the decarbonisation of the energetic system and to reduce the fossil fuel dependence. A significant interest has been growing in long-chain additive alcohols as ternary Biodiesel-Petrodiesel-Oxigenated blends [1, 2], and indeed, bio-butanol has attracted interest as oxygenated compound because of its closer properties to the fossil-sourced fuels [3]. This contribution focuses on the study and development of different optimized Biodiesel-Petrodiesel- (bio)Butanol ternary advanced fuel blends and their performance on the different engine parameters and gas-emissions in a real diesel engine.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Hydrogen co-injection as a bridged technology for internal combustion engines

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    In order to survive at media-term, diesel engines need a new approach for the use of the new fuel portfolio and to control the exhaust gas emissions. Hydrogen has been proposed as an alternative due to its excellent combustion properties, which could improve the combustion performance and emissions of internal combustion engines [1, 2]. The main drawback is that the location of a hydrogen cylinder inside the vehicles implies space and risk problems. Therefore, it could be produced on board and released into the air-intake of any biofuels fed to diesel engines. For that, the required optimized amount of hydrogen must be known, studying all engine parameters and emission in different driving modes for the establishment of the engine regions of operation in which partial replacement of fuel by hydrogen is effective as a bridged technology.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Mixed Oxides Derived from Hydrotalcites Mg/Al Active in the Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol

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    Herein, a family of Mg/Al hydrotalcites was synthesized as catalytic precursors of MgAlOx mixed oxides. Both hydrotalcites and mixed oxides were characterized and the mixed oxides were tested in the reduction of furfural to yield furfuryl alcohol by MPV reaction using isopropanol as hydrogen donor. Different catalytic parameters were tested, such as the type of alcohol, calcination temperature of the hydrotalcite, and reaction temperature. Furfural and isopropanol were adsorbed on the MgAl-3 catalyst to follow the species adsorbed on the catalyst by FTIR analysis. The results showed that the isopropanol was activated as isopropoxide and furfural changed the adsorption site with increasing temperature but maintaining the h1-conformation. The catalytic performances were associated with the basicity of the catalysts and the deactivation processes have been attributed to the existence of adsorbed species on the surface, mainly due to furfural-derived compounds. The catalysts were reused in three consecutive cycles showing a sharp drop of catalytic activity. To recover the activity, the catalysts were calcined at 500 °C but the activity was only partially recovered. The XPS analysis after reactivation showed that the catalyst surface was modified due to the segregation of hydroxides of Mg and Al.This research was funded by the Spanish Ministry of Science and Innovation (PID2021-122736OB-C42), FEDER (European Union) funds (PID2021-122736OB-C42, P20-00375, UMA20-FEDERJA88). Partial funding for open access charge: Universidad de Málag

    Karst: a very diverse concept

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    La gran diversidad intrínseca del karst y la variedad de campos científicos desde los que ha sido estudiado este medio ha generado un espectacular aumento de su conocimiento. Ese avance ha venido acompañado también de nuevas incógnitas y nuevos planteamientos. El presente trabajo trata de recoger una pequeña muestra de esa amplia diversidad, asociada a un elevado grado de especialización, que de forma integrada permite completar el puzzle del karst. Inicialmente, se presenta una revisión sintética del concepto de karst, del proceso de karstificación y de las morfologías asociadas al mismo. Seguidamente, y planteado a partir de una serie de interrogantes, se muestran algunos aspectos y curiosidades relacionadas con el karst. Las características microclimáticas subterráneas, el karst no tradicional o los depósitos y mineralizaciones asociados al karst, son algunos de los temas que se incluyen en este trabajo y que puede interesar a los docentes que imparten docencia sobre el karst.The great intrinsic diversity of karst and the variety of scientific fields in which it has been studied has generated a dramatic increase in our knowledge about it. This advance has also been accompanied by new questions and issues that open the door to new approaches. Our work intends to show a small sample of the wide diversity, often associated with a high degree of specialization, which allows completing the karst puzzle. In the first place, this paper provides a synthetic review of the concept of karst, the karstification process and the morphologies associated with it. Next, starting with a few questions, it shows some aspects and curiosities related to karst. The features of the underground microclimate, the non-traditional karst or deposits and mineralization associated with karst, are some of the topics included in this work, which can be interesting for the teachers dealing with the topic of karst in their classes
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