1,278 research outputs found

    Blackspot seabream early life stages dispersal by hydrodynamic modelling (Strait of Gibraltar - Alboran Sea)

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    The Blackspot seabream (Pagellus bogaraveo) is a commercially appreciated demersal fish, widespread in the north-eastern Atlantic and middle-western Mediterranean. The Strait of Gibraltar (SoG) is an important fishing area where artisanal fleets from Spain and Morocco target this species using special longline gears known as “voracera”. Different studies on the health status of this species claim an overexploitation of the resource without any kind of objective management measures implemented yet by the associated countries. Improving the knowledge of the population dynamics, and particularly during the spawning window, is crucial for a better management of the fishing effort for this species. There is an agreement in literature in considering the SoG as an especially energetic and dispersive spawning zone for this species. Once spawned, eggs and larvae (ELS) are assumed to be scattered by the currents towards both sides of the SoG, mostly to the eastwards Alboran basin, where high concentrations of juveniles occur. A high resolution hydrodynamic model coupled to a Lagrangian particle tracking system is employed to assess the potential dispersal pathways of blackspot seabream ELS spawned in the SoG. Recursive releases of passive tracers in different virtual spawning spots and depths within the SoG region are tracked under different tidal conditions in order to obtain an overall characterization of the spatial dispersion patterns of the studied species. Semidiurnal tidal currents emerge as the primary factor in determining the horizontal dispersion and pathway of the spawning products, although the spring-neap tidal cycle and the spawning depth can be also important variables depending on the region considered as well as the arrival zone for the ELS dispersal paths over the Alboran SeaUniversidad de Málaga. Campus de Excelencia Internacional CEIMA

    Live lecture screencast recording: a proposal to simplify the tasks associated with content production for video-teaching

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    Se trata de un resumen (Abstract) de la contribución. El acuerdo de transferencia de copyright del trabajo completo es incompatible con el depósito del mismo en RIUMA.Se describe la implementación inicial de un método simplificado de grabación en directo de sesiones de clase en asignaturas de las Escuelas de Ingeniería de la Universidad de Málaga. La simplificación se logra al incorporar en la actividad diaria del aula ciertas características típicas de la grabación en diferido de mini videos docentes. En una configuración mínima se graba únicamente el audio y el video en pantalla de la clase, evitando los desafíos técnicos y las dificultades que implica la grabación de otros elementos como la pizarra. Esto implica el uso de anotaciones en pantalla en tiempo real para reemplazar completamente las anotaciones en la pizarra.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. I Plan Propio Integral de Docencia. Universidad de Málaga. Universidad de Málaga. Vicerectorado de Personal Docente e Investigador, Proyectos de Innovación Educativa (PIE 17-018

    Is true friendship possible on Facebook? A study from the psychological perspective of LaĂ­n Entralgo

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    The present work aims to analyse the meaning of the concept of friendship through the study of the work of the doctor and philosopher Pedro Laín Entralgo. The initial hypothesis of the study is that the concept of friendship has been used instrumentally by social media networks, and that these do not offer the conditions necessary to fully experience true friendship. To verify this, we focused on the study of the psychological dimensions of friendship proposed by the author, identifying a series of variables and conducting an analysis by means of a survey of university students who are active users of the platform. With these results the descriptive statistics were extracted and a nonparametric analysis was performed of the variables to determine if Facebook does in fact offer the conditions necessary for to experience true friendship in its psychological dimensions. As the results show, to experience true friendship on social networks is difficult, given that the nature of the interactions between users of the platform are not appropriate for this experience. In calling this different type of relationship friendship Facebook benefits from an attractive hook which leads users to generate contacts as a form of currency which benefits the business model of the social media platform. The concept of true friendship is altered, deformed and displaced in favour of other types of relationships.El presente trabajo tiene como objetivo analizar el significado del concepto de amistad a través del estudio de la obra del médico y filósofo Pedro Laín Entralgo. La hipótesis inicial del estudio es que el concepto de amistad ha sido utilizado instrumentalmente por las redes sociales, y que estas no ofrecen las condiciones necesarias para la vivencia plena de la verdadera amistad. Para comprobarlo, nos centramos en el estudio de las dimensiones psicológicas de la amistad que propone el autor, identificando una serie de variables y realizando un análisis mediante una encuesta a estudiantes universitarios que son usuarios activos de la plataforma. Con estos resultados se extrajo la estadística descriptiva y se realizó un análisis no paramétrico de las variables para determinar si Facebook efectivamente ofrece las condiciones necesarias para la vivencia de la verdadera amistad en sus dimensiones psicológicas. Como muestran los resultados, la experiencia de la verdadera amistad en las redes sociales es difícil, dado que la naturaleza de las interacciones entre los usuarios de la plataforma no son las adecuadas para esta experiencia. Al llamar amistad a este tipo diferente de relación, Facebook se beneficia de un atractivo gancho que lleva a los usuarios a generar contactos como moneda de cambio que favorece el modelo de negocio de la plataforma de redes sociales. El concepto de verdadera amistad se altera, deforma y desplaza a favor de otro tipo de relaciones

    Cinética y estructura microbiana de las bacterias del ciclo del nitrógeno de la rizosfera de un humedal natural contaminado con cromo

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    En el manuscrito se describe la estructura y composición microbiana de un lodo de un humedal natural y sus conductas cinéticas de la nitrificación, desnitrificación y anammox, en presencia y ausencia de cromoWetlands have been considered a feasible technology for wastewater treatment in the last decades; however, information on the kinetics and microbial structure of nitrogen cycle bacteria involved on the rhizosphere activity of natural wetlands polluted with chromium is still scarce. The goal was to evaluate the kinetic behavior of nitrification, denitrification, and ANAMMOX on rhizosphere sludge, with and without chromium, through batch cultures, as well as the microbial structure using Next Generation Sequencing (NGS). The microbial sludge was able to nitrify (3.8 ± 0.2 mg NO3--N/gVSS-h) and carry out the ANAMMOX (0.67 ± 0.05 mg NH4+-N/gVSS-h), however, denitrifying activity was not observed. Chromium inhibited the nitrifying process, and the IC50 obtained for the nitrifying activity was of 7.9 mg CrVI/L. ANAMMOX activity was stopped in the presence of chromium, even to the lowest chromium concentration tested. Recovery cultures showed that ANAMMOX bacteria suffered some damage by chromium presence since they required more than 5 days to recover the activity. Microbial results indicated that Xanthomonadaceae (17.17%), Ignavibacteriaceae (16.52%), Trueperaceae (10.66%) and Chitinophagaceae (10.06%) dominated in the microbial sludge, whereas Nitrosomonas and Planctomycetaceae were in lesser proportion. This research improves the understanding of bacteria behavior on natural wetlands polluted with metals

    Análisis de la calidad del servicio en el transporte público mediante redes neuronales artificiales

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    [ES] El éxito de un servicio de transporte público reside en su capacidad para captar nuevos pasajeros y de fidelizar el uso de los actuales. De ahí que las administraciones y los gestores de transporte se preocupen cada vez más por conocer cuál es la calidad percibida por los usuarios. Aunque existen numerosos métodos matemáticos que ya han sido utilizados para analizar la calidad del servicio en el transporte público, es necesario seguir avanzando en el estudio de nuevas técnicas que sean válidas para su estudio. En esta ponencia se aplica la técnica de las redes neuronales artificiales al estudio de la calidad del servicio en el transporte público. La metodología novedosa desarrollada al aplicar las redes neuronales artificiales mitiga considerablemente las principales limitaciones que éstas presentan, por lo que además de aportar una nueva herramienta para análisis de la calidad del servicio en el transporte público, pone a disposición de los especialistas en esta técnica un nuevo procedimiento de aplicación de las redes neuronales artificiales aplicable a cualquier campo de estudio en el que esta técnica sea aplicada.Garrido Rodriguez, M.; De Oña Lopez, JJ. (2016). Análisis de la calidad del servicio en el transporte público mediante redes neuronales artificiales. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 2143-2165. https://doi.org/10.4995/CIT2016.2015.4120OCS2143216

    The role of axonal Kv1 channels in CA3 pyramidal cell excitability

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    Axonal ion channels control spike initiation and propagation along the axon and determine action potential waveform. We show here that functional suppression of axonal Kv1 channels with local puff of dendrotoxin (DTx), laser or mechanical axotomy significantly increased excitability measured in the cell body. Importantly, the functional effect of DTx puffing or axotomy was not limited to the axon initial segment but was also seen on axon collaterals. In contrast, no effects were observed when DTx was puffed on single apical dendrites or after single dendrotomy. A simple model with Kv1 located in the axon reproduced the experimental observations and showed that the distance at which the effects of axon collateral cuts are seen depends on the axon space constant. In conclusion, Kv1 channels located in the axon proper greatly participate in intrinsic excitability of CA3 pyramidal neurons. This finding stresses the importance of the axonal compartment in the regulation of intrinsic neuronal excitability

    Resistance gene pool to co-trimoxazole in non-susceptible Nocardia strains

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    The soil-borne pathogen Nocardia sp. causes severe cutaneous, pulmonary, and central nervous system infections. Against them, co-trimoxazole (SXT) constitutes the mainstay of antimicrobial therapy. However, some Nocardia strains show resistance to SXT, but the underlying genetic basis is unknown. We investigated the presence of genetic resistance determinants and class 1-3 integrons in 76 SXT-resistant Nocardia strains by PCR and sequencing. By E test, these clinical strains showed SXT minimum inhibitory concentrations of ≥32:608 mg/L (ratio of 1:19 for trimethoprim: sulfamethoxazole). They belonged to 12 species, being the main representatives Nocardia farcinica (32%), followed by N. flavorosea (6.5%), N. nova (11.8%), N. carnea (10.5%), N. transvalensis (10.5%), and Nocardia sp. (6.5%). The prevalence of resistance genes in the SXT-resistant strains was as follows: sul1 and sul2 93.4 and 78.9%, respectively, dfrA(S1) 14.7%, blaTEM-1 and blaZ 2.6 and 2.6%, respectively, VIM-2 1.3%, aph(3')-IIIa 40.8%, ermA, ermB, mefA, and msrD 2.6, 77.6, 14.4, and 5.2%, respectively, and tet(O), tet(M), and tet(L) 48.6, 25.0, and 3.9%, respectively. Detected amino acid changes in GyrA were not related to fluoroquinolone resistance, but probably linked to species polymorphism. Class 1 and 3 integrons were found in 93.42 and 56.57% strains, respectively. Class 2 integrons and sul3 genes were not detected. Other mechanisms, different than dfrA(S1), dfrD, dfrF, dfrG, and dfrK, could explain the strong trimethoprim resistance shown by the other 64 strains. For first time, resistance determinants commonly found in clinically important bacteria were detected in Nocardia sp. sul1, sul2, erm(B), and tet(O) were the most prevalent in the SXT-resistant strains. The similarity in their resistome could be due to a common genetic platform, in which these determinants are co-transferred.This study was presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy, ICAAC2014, Washington, DC, USA. We thank Adrian Burton for editing and language assistance (http://physicalevidence.es/english/welcome). We are very grateful to all persons who took part in this study, and to the sample providers.S

    Estradiol Activates β-Catenin Dependent Transcription in Neurons

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    Estradiol may fulfill a plethora of functions in neurons, in which much of its activity is associated with its capacity to directly bind and dimerize estrogen receptors. This hormone-protein complex can either bind directly to estrogen response elements (ERE's) in gene promoters, or it may act as a cofactor at non-ERE sites interacting with other DNA-binding elements such as AP-1 or c-Jun. Many of the neuroprotective effects described for estrogen have been associated with this mode of action. However, recent evidence suggests that in addition to these “genomic effects”, estrogen may also act as a more general “trophic factor” triggering cytoplasmic signals and extending the potential activity of this hormone. We demonstrated that estrogen receptor alpha associates with β-catenin and glycogen synthase kinase 3 in the brain and in neurons, which has since been confirmed by others. Here, we show that the action of estradiol activates β-catenin transcription in neuroblastoma cells and in primary cortical neurons. This activation is time and concentration-dependent, and it may be abolished by the estrogen receptor antagonist ICI 182780. The transcriptional activation of β-catenin is dependent on lymphoid enhancer binding factor-1 (LEF-1) and a truncated-mutant of LEF-1 almost completely blocks estradiol TCF-mediated transcription. Transcription of a TCF-reporter in a transgenic mouse model is enhanced by estradiol in a similar fashion to that produced by Wnt3a. In addition, activation of a luciferase reporter driven by the engrailed promoter with three LEF-1 repeats was mediated by estradiol. We established a cell line that constitutively expresses a dominant-negative LEF-1 and it was used in a gene expression microarray analysis. In this way, genes that respond to estradiol or Wnt3a, sensitive to LEF-1, could be identified and validated. Together, these data demonstrate the existence of a new signaling pathway controlled by estradiol in neurons. This pathway shares some elements of the insulin-like growth factor-1/Insulin and Wnt signaling pathways, however, our data strongly suggest that it is different from that of both these ligands. These findings may reveal a set of new physiological roles for estrogens, at least in the Central Nervous System (CNS)
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