University of GranadaGranada


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Perez de Vargas-Sansalvador I.M.,University of GranadaGranada | Perez de Vargas-Sansalvador I.M.,Insight Centre for Data Analytics | Erenas M.M.,University of GranadaGranada | Diamond D.,Insight Centre for Data Analytics | And 2 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

A new water-based sensor for carbon dioxide containing an ionic liquid is presented. The sensor is based on the acidity of the CO2 molecule. The sensor incorporates an ionic liquid in the matrix, which enhances CO2 solubility, and minimising the response and recovery times of the sensor. The entire concentration range (0–100%) of CO2 in water has been studied. The sensor is more sensitive at low CO2 concentrations as is usual in this kind of optical sensor. As the sensor is intended for smart food packaging, one of the most important characteristics is stability, and this has been studied under different conditions of light, temperature and relative humidity. The sensor was found to be stablef or more than 14 days, which is the period of use for the intended application. Pork chops were packed at 4 °C and the production of CO2 studied in conjunction with total bacterial counts over a period of 14 days. The results show that the concentration of CO2 dioxide increases in time, in correlation with bacterial counts. As the threshold of CO2 content for human consumption of this meat is 20%, the sensor has been optimised for detection around this concentration. © 2017 Elsevier B.V.

Almecija M.C.,University of GranadaGranada | Guadix A.,University of GranadaGranada | Calvo J.I.,Applied Materials | Guadix E.M.,University of GranadaGranada
Food and Bioproducts Processing | Year: 2017

The purpose of this work was to evaluate the effect of the temperature (50 and 60 °C) of a NaOH cleaning solution during the diafiltration of a binary mixture of bovine serum albumin and β-lactoglobulin, through a 300 kDa tubular ceramic membrane along repeated operational cycles. To this aim, final permeate volume, membrane and fouling resistances and individual protein concentration were analyzed. At the end of each individual study, the membranes were characterized by liquid–liquid displacement porosimetry. As a result, 50 °C was found to be the most appropriated temperature due to its higher capability to restore the initial membrane resistance and the higher efficiency achieved in terms of protein separation. Both conditions fulfilled without altering the structural properties of the membrane as given by porosimetric analysis. In contrast, a great fouling resistance involving null protein transmission occurred when cleaning was performed at 60 °C. © 2017 Institution of Chemical Engineers

Fernandez-Rodriguez M.A.,University of GranadaGranada | Ramos J.,University of the Basque Country | Ramos J.,Institute for Biomedical Engineering | Isa L.,ETH Zurich | And 3 more authors.
Langmuir | Year: 2015

Surface heterogeneity affects the behavior of nanoparticles at liquid interfaces. To gain a deeper understanding on the details of these phenomena, we have measured the interfacial activity and contact angle at water/decane interfaces for three different types of nanoparticles: homogeneous poly(methyl methacrylate) (PMMA), silica functionalized with a capping ligand containing a methacrylate terminal group, and Ag-based Janus colloids with two capping ligands of different hydrophobicity. The interfacial activity was analyzed by pendant drop tensiometry, and the contact angle was measured directly by freeze-fracture shadow-casting cryo-scanning electron microscopy. The silver Janus nanoparticles presented the highest interfacial activity, compared to the silica nanoparticles and the homogeneous PMMA nanoparticles. Additionally, increasing the bulk concentration of the PMMA and silica nanoparticles up to 100-fold compared to the Janus nanoparticles led to silica particles forming fractal-like structures at the interface, contrary to the PMMA particles that did not show any spontaneous adsorption. © 2015 American Chemical Society.

Ariza-Vega P.,Rehabilitation And Traumatology Virgen Of Las Nieves University Hospitalgranada | Ariza-Vega P.,University of GranadaGranada | Kristensen M.T.,Copenhagen University | Martin-Martin L.,University of GranadaGranada | And 2 more authors.
Archives of Physical Medicine and Rehabilitation | Year: 2015

Abstract Objectives To determine 1-year mortality and predisposing factors in older people who had surgery after a hip fracture. Design Prospective cohort study. Setting Public acute hospital, trauma service. Participants Patients (N=281) aged ≥65 years who were admitted to the hospital with a hip fracture from January 2009 to January 2010, and followed up for 1 year thereafter. Interventions Not applicable. Main Outcome Measures Cumulative survival probability up to 1 year from surgery was calculated by means of Kaplan-Meier charts, and Cox regression models were performed to analyze the factors associated with mortality. Data were collected from medical charts and by interviews. Health status was evaluated using the American Society of Anesthesiologists rating, prefracture functional level with the FIM, and cognitive status with the Pfeiffer score. Results The 1-year mortality for the 281 patients who were followed up was 21% (95% confidence interval [CI], 16.1%-25.9%). A non-weight-bearing status was associated with increased mortality in unadjusted analyses (hazard ratio [HR]=1.99; 95% CI, 1.16-3.43), but 5 other factors were identified when entered into the multiple Cox regression model: age (HR=1.05; 95% CI, 1-1.09), male sex (HR=2.92; 95% CI, 1.58-5.39), low health status (HR=2.8; 95% CI, 1.29-6.09), low prefracture function (HR=.98; 95% CI,.97-.99), and change of residence (HR=3.21; 95% CI, 1.43-7.17). Conclusions The overall 1-year mortality rate was 21%. Change of residence is the only potentially modifiable risk factor, independent of the following other traditional risk factors that were found: age, sex, health status, and prefracture functional level. Furthermore, 2 to 4 weeks of non-weight-bearing status, which is considered modifiable, is also associated with increased mortality rates in unadjusted analyses. © 2015 American Congress of Rehabilitation Medicine.

Canadas L.,Autonomous University of Madrid | Ruiz J.R.,University of GranadaGranada | Veiga O.L.,Autonomous University of Madrid | Gomez-Martinez S.,Institute of Food Science and Technology and Nutrition | And 6 more authors.
Nutricion Hospitalaria | Year: 2014

Methods: Participants included 2606 (49.3% girls) adolescents from AVENA and UP&DOWN studies. physical education enjoyment was assessed with a 7-point Likert scale. Fatness was assessed with BMI, skinfolds and waist circumference. Physical fitness was assessed with cardiorespiratory, motor and muscular fitness tests.Results: Boys who dislike physical education had similar levels of fatness and fitness than their peers (all P>0.05). Adolescent girls who dislike physical education had higher levels in body fat (P=0.035), and lower levels in muscular (P=0.007) and motor (P=0.007) fitness than their peers.Conclusion: Since only girls who dislike physical education seem to have, albeit weak, higher levels of fatness and lower of fitness than their peers, it partially confirms the myth in adolescent girls.Introduction: In the physical education context a well-known myth suggest that obese and unfit youth dislike physical education.Objective: To examine if adolescents who dislike physical education have higher levels of fatness and lower of fitness than their peers. © 2014, Grupo Aula Medica S.A. All rights reserved.

Alejandro Gonzalez M.,University of GranadaGranada | Delgado A.V.,University of GranadaGranada | Rica R.A.,University of GranadaGranada | Jimenez M.L.,University of GranadaGranada | Ahualli S.,University of GranadaGranada
Langmuir | Year: 2015

In this work we discuss the electrokinetic evaluation of model platelike particles. By model particles we mean homogeneous and controlled size and shape. The electrokinetic analysis in such complex geometries cannot be limited to a single data point as in usual electrophoresis in constant (dc) fields. The information can be made much richer if alternating (ac) fields with a sufficiently wide range of frequencies are used. In this case, two techniques can be applied: one is the determination of the frequency spectrum of the electric permittivity or dielectric constant (low-frequency dielectric dispersion), and the other is the electroacoustics of suspensions and the determination of the frequency dispersion of the electrophoretic mobility (dynamic or ac mobility). In this work, these techniques are used with planar gibbsite (γ-Al(OH)3) particles, modeled as oblate spheroids with a small aspect ratio. As in other laminar minerals, a particular charge distribution, differing between edges and faces, gives rise to very peculiar electrokinetic behavior. It is found that pH 7 approximately separates two distinct field responses: below that pH the dielectric dispersion and dynamic mobility data are consistent with the existence of individual, highly charged platelets, with charge mainly originating on edge surfaces. At pH 4, a low-frequency relaxation is observed, which must originated from larger particles. It is suggested that these are individual ones bridged by negatively charged fiberlike structures, coming from the partial decomposition of gibbsite particles. On the other side of the measured pH spectrum, the overall charge of the particles is low, and this probably produces aggregates with a relatively large average size, with relaxation frequencies on the low side. This is confirmed by dynamic mobility data, showing that a coherent picture of the nanostructure can be reached by combining the two techniques. © 2015 American Chemical Society.

Liberatore F.,University of GranadaGranada | Mora A.M.,University of GranadaGranada | Castillo P.A.,University of GranadaGranada | Guervos J.J.M.,University of GranadaGranada
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

Flocking strategies are sets of behavior rules for the interaction of agents that allow to devise controllers with reduced complexity that generate emerging behavior. In this paper, we present an application of genetic algorithms and flocking strategies to control the Ghost Team in the game Ms. Pac-Man. In particular, we define flocking strategies for the Ghost Team and optimize them for robustness with respect to the stochastic elements of the game and effectivity against different possible opponents bymeans of genetic algorithm. The performance of the methodology proposed is tested and compared with that of other standard controllers. The results show that flocking strategies are capable of modeling complex behaviors and produce effective and challenging agents. © Springer-Verlag Berlin Heidelberg 2014.

Aviles A.,University of GranadaGranada | Takimoto M.,University of Tokyo | Kambayashi Y.,Nippon Institute of TechnologySaitama
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

This paper proposes a distributed multi-agent framework for discovering and optimizing evacuation routes on demand. Our framework assumes mobile ad hoc networks (MANETs) composed of smartphones with geo-location capabilities. On the network, heterogeneous mobile agents cooperatively insert knowledge about crowd in our mass evacuation framework. They are relying exclusively on crowd sourcing; therefore our framework is layout independent and adaptable for any situation. The mobile agents take advantage of ant colony optimization (ACO) in order to collect such knowledge. Once users reach safe areas, they distribute agents to inform the directions of the locations of the safe areas. On the other hand, evacuating users distribute agents to search safe areas, based on guidance given by the agents from the safe areas. Once each searching agent reaches the safe area, it traces its path backwardly collecting geographical information of intermediate nodes for composing an evacuation route. During the backward travel, agents lay down pheromone as they migrate back based on the ACO algorithm, strengthening quasi-optimal physical routes, and hence guiding succeeding agents. A characteristic of pheromone in this family of algorithms is that it lessens during run-time, keeping the information about successful escape routes current, as is essential in an evacuation scenario. We have implemented a simulator based on our framework in order to show the effectiveness of our technique. We discuss the behaviors of our system with various settings on the simulator for real world implementation in the near future. © Springer-Verlag Berlin Heidelberg 2014.

PubMed | University of Alicante and University of GranadaGranada
Type: | Journal: Frontiers in microbiology | Year: 2016

The production of virulence factors by many pathogenic microorganisms depends on the intercellular communication system called quorum sensing, which involves the production and release of signal molecules known as autoinducers. Based on this, new-therapeutic strategies have emerged for the treatment of a variety of infections, such as the enzymatic degradation of signaling molecules, known as quorum quenching (QQ). In this study, we present the screening of QQ activity amongst 450 strains isolated from a bivalve hatchery in Granada (Spain), and the selection of the strain PQQ-42, which degrades a wide range of N-acylhomoserine lactones (AHLs). The selected strain, identified as Alteromonas stellipolaris, degraded the accumulation of AHLs and reduced the production of protease and chitinase and swimming motility of a Vibrio species in co-cultivation experiments in vitro. In the bio-control experiment, strain PQQ-42 significantly reduced the pathogenicity of Vibrio mediterranei VibC-Oc-097 upon the coral Oculina patagonica showing a lower degree of tissue damage (29.25 14.63%) in its presence, compared to when the coral was infected with V. mediterranei VibC-Oc-097 alone (77.53 13.22%). Our results suggest that this AHL-degrading bacterium may have biotechnological applications in aquaculture.

PubMed | Cairo University, University of GranadaGranada and Egyptian Russian University
Type: | Journal: Frontiers in pharmacology | Year: 2016

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