2,287 research outputs found

    Aplicación de isótopos ambientales en la determinación de la biodegradación de compuestos orgánicos

    Get PDF
    Se realizaron experimentos de microcosmos para determinar el fraccionamiento de los isótopos estables de carbono durante la biodegradación de naftaleno. Los microcosmos se realizaron bajo condiciones aeróbicas, anaeróbicas (con adiciones de sulfatos, con adiciones de nitratos y sin adiciones) y controles estériles. Se analizó la fase líquida para determinar la concentración e isótopos estables de carbono de naftaleno. Los microcosmos aeróbicos muestran que el naftaleno se degradó aeróbicamente en menos de 60 horas. El d13C se incrementó de -25.5 a -25.1‰ (enriquecimiento de 0.4 ± 0.08‰) en una sola muestra, en la que 95% del naftaleno había sido biodegradado. Los microcosmos anaeróbicos muestran que después de 288 días, los microcosmos sin adiciones, con adición de NO3 - y con adición de SO4 = habían consumido, respectivamente, 30, 50 y 60% de naftaleno en promedio, comparados con los microcosmos de control. Bajo condiciones desnitrificantes, el d13C de naftaleno aumentó de -25.2 a -23.9‰ (enriquecimiento de 1.3 ± 0.3‰) después de una biodegradación de 95% del naftaleno. Para los microcosmos sin adiciones se detectó un ligero enriquecimiento en d13C de naftaleno de -25.2 a -24.5‰ (enriquecimiento de 0.7±0.3‰) después de una biodegradación de un 65% (después de 288 días). Para los microcosmos en condiciones reductoras de SO4 = no se percibieron cambios significativos en el d13C de naftaleno durante su biodegradación

    La importancia de la contragarantía en el juicio de nulidad

    Get PDF
    La presente investigación se centra en el análisis de una laguna normativa en la Ley de Justicia Administrativa del Estado de Jalisco, la cual consiste en la falta de regulación en dicho ordenamiento respecto a la figura jurídica de la contragarantía dentro del juicio de nulidad. A través de esta se han originado, en ciertos casos, prácticas ilícitas y conductas indebidas. En ese sentido este trabajo se centra en demostrar y justificar jurídicamente las razones por las cuales, a pesar de que no se encuentra debidamente regulada dicha figura en la legislación, la aplicación de esta no es solo posible, sino que es necesaria y se justifica el por qué debe ser incluida en la legislación estatal en estudio.ITESO, .A.C

    Semantic Invoice Processing

    Get PDF
    This work highlights how to transform information from invoice documents to semantic models, as an implementation of ontology modeling. The migration from printed paper to digital documents in the Mexican Government Offices in the last few years has brought significant opportunities for the usage of information technologies and applications. However, when changing digital document information into knowledge, there are still many gaps to be filled. This work proposes a solution to some issues regarding ontology modeling, specifically when mapping a document that follows some XML schema to an ontology under the OWL standard. The main contribution of this work is to provide new interpretations of the XML terms in the context of OWL, so that the XML Schema Definition (XSD) structures can be mapped into more complex OWL structures. A software tool developed to test and validate the information extraction strategies proposed is presented here.ITESO, A.C.Consejo Nacional de Ciencia y Tecnologí

    Development and testing of a novel steel formwork for casting concrete slabs with different sizes

    Get PDF
    This paper describes and discusses the results of designing and implementing a steel formwork for casting and testing concrete slab specimens with different sizes. The formwork saves space, materials and costs due to the different configurations it may adopt, which allow, for instance, casting slabs with different sizes. The formwork avoids purchasing a greater number of formworks of particular dimensions, which increases costs and the space needed for storage. The formwork performance was assessed through the analysis of numerical results (strain and stress) obtained from simulations using finite element software. Performance was also verified during construction and testing of concrete slab specimens, reinforced with welded-wire meshes or steel fibers. The novel steel formwork herein presented and discussed is currently a patent pending in the Colombian Office of Industry and Commerce

    Absolute agreement and consistency of the OptoGait system and Freemed platform for measuring walking gait

    Get PDF
    The gait cycle can be divided into four functional rocker units. Although the widespread use of the OptoGait (OG) system and the Freemed (FM) platform, their accuracy has not been tested. An observational study was completed with eighteen healthy volunteers to determine the accuracy of OG and FM for overground walking gait analysis. The pairwise comparison between data obtained from OG, FM and high-speed video analysis revealed significant differences for most of the measurements (p  0.94) for all measures for OG systems compared to video-analysis. When considering FM vs. video-analysis, ICCs showed good absolute agreement for rocker 1 (ICC = 0.86) and 3 (ICC = 0.82), excellent for rocker 2 (ICC = 0.93) and poor (ICC  0.1) while no heteroscedasticity of error was found when using FM (r2 < 0.1). This study indicates that the OG system and the FM platform can provide consistent foot rockers values when walking at a constant velocity. The differences between the systems assessed and their agreement and consistency values advise against their interchangeable use

    Special fast diffusion with slow asymptotics. Entropy method and flow on a Riemannian manifold

    Full text link
    We consider the asymptotic behaviour of positive solutions u(t,x)u(t,x) of the fast diffusion equation ut=Δ(um/m)=div(um1u)u_t=\Delta (u^{m}/m)={\rm div} (u^{m-1}\nabla u) posed for x\in\RR^d, t>0t>0, with a precise value for the exponent m=(d4)/(d2)m=(d-4)/(d-2). The space dimension is d3d\ge 3 so that m<1m<1, and even m=1m=-1 for d=3d=3. This case had been left open in the general study \cite{BBDGV} since it requires quite different functional analytic methods, due in particular to the absence of a spectral gap for the operator generating the linearized evolution. The linearization of this flow is interpreted here as the heat flow of the Laplace-Beltrami operator of a suitable Riemannian Manifold (\RR^d,{\bf g}), with a metric g{\bf g} which is conformal to the standard \RR^d metric. Studying the pointwise heat kernel behaviour allows to prove {suitable Gagliardo-Nirenberg} inequalities associated to the generator. Such inequalities in turn allow to study the nonlinear evolution as well, and to determine its asymptotics, which is identical to the one satisfied by the linearization. In terms of the rescaled representation, which is a nonlinear Fokker--Planck equation, the convergence rate turns out to be polynomial in time. This result is in contrast with the known exponential decay of such representation for all other values of mm.Comment: 37 page

    Is There a Relationship between the Morphology of Connective Tissue and Reactivity during a Drop Jump? Influence of Sex and Athletic Performance Level

    Get PDF
    The influence of the morphologic characteristics of connective tissue, which plays an essential role during sports activities, on sporting tasks needs further research given the controversial findings reported in the literature. This study aimed at examining the relationship between lower limb connective tissue morphology and drop jump reactivity and determining the influence of sex and athletic performance level. A total of 30 men and 14 women, runners, executed 6 drop jumps (3 20 cm and 30 cm height respectively) and their thickness and cross-sectional area were recorded for Achilles and patellar tendons and plantar fascia. No significant results were found in the relationship between the morphology of the connective tissue and reactivity strength index for both sexes. Significant sex differences were found, while women showed greater values (p < 0.005) for Achilles tendon and plantar fascia; men showed greater values for reactivity strength index and drop jump performance (p < 0.001). The present study shows a limited relationship between connective tissue morphology and drop jump reactivity. Additionally, women showed greater normalized values for Achilles tendon and plantar fascia, and men showed greater reactivity strength index and jumping performance values. No relationships between athletic performance level and connective tissue were found

    Mechanical Power in Endurance Running: A Scoping Review on Sensors for Power Output Estimation during Running

    Get PDF
    Mechanical power may act as a key indicator for physiological and mechanical changes during running. In this scoping review, we examine the current evidences about the use of power output (PW) during endurance running and the di erent commercially available wearable sensors to assess PW. The Boolean phrases endurance OR submaximal NOT sprint AND running OR runner AND power OR power meter, were searched in PubMed, MEDLINE, and SCOPUS. Nineteen studies were finally selected for analysis. The current evidence about critical power and both power-time and power-duration relationships in running allow to provide coaches and practitioners a new promising setting for PW quantification with the use of wearable sensors. Some studies have assessed the validity and reliability of di erent available wearables for both kinematics parameters and PW when running but running power meters need further research before a definitive conclusion regarding its validity and reliability

    Mutant huntingtin enhances activation of dendritic Kv4 K+ channels in striatal spiny projection neurons

    Get PDF
    Huntington\u27s disease (HD) is initially characterized by an inability to suppress unwanted movements, a deficit attributable to impaired synaptic activation of striatal indirect pathway spiny projection neurons (iSPNs). To better understand the mechanisms underlying this deficit, striatal neurons in ex vivo brain slices from mouse genetic models of HD were studied using electrophysiological, optical and biochemical approaches. Distal dendrites of iSPNs from symptomatic HD mice were hypoexcitable, a change that was attributable to increased association of dendritic Kv4 potassium channels with auxiliary KChIP subunits. This association was negatively modulated by TrkB receptor signaling. Dendritic excitability of HD iSPNs was rescued by knocking-down expression of Kv4 channels, by disrupting KChIP binding, by restoring TrkB receptor signaling or by lowering mutant-Htt (mHtt) levels with a zinc finger protein. Collectively, these studies demonstrate that mHtt induces reversible alterations in the dendritic excitability of iSPNs that could contribute to the motor symptoms of HD
    corecore