2,103 research outputs found

    Resolving the Problem of Intelligent Learning Content in Learning Management Systems

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    Current e-learning standardization initiatives have put much effort into easing interoperability between systems and the reusability of contents. For this to be possible, one of the most relevant areas is the definition of a run-time environment, which allows Learning Management Systems to launch, track and communicate with learning objects. However, when dealing with intelligent content, these environments show important restrictions. In this article, we study these restrictions, comparing several standardized run-time environments with nonstandardized solutions that aim to overcome these constraints

    Glyphosate resistance in perennial Sorghum halepense (Johnsongrass), endowed by reduced glyphosate translocation and leaf uptake

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    Background: In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and 14C-glyphosate leaf absorption and translocation to meristematic tissues. Results: Individuals of all resistant (R) accessions exhibited significantly less glyphosate translocation to root (11% versus 29%) and stem (9% versus 26%) meristems when compared with susceptible (S) plants. A notably higher proportion of the applied glyphosate remained in the treated leaves of R plants (63%) than in the treated leaves of S plants (27%). In addition, individuals of S. halepense accession R 2 consistently showed lower glyphosate absorption rates in both adaxial (10-20%) and abaxial (20-25%) leaf surfaces compared with S plants. No glyphosate resistance endowing mutations in the EPSPS gene at Pro-101-106 residues were found in any of the evaluated R accessions. Conclusion: The results of the present investigation indicate that reduced glyphosate translocation to meristems is the primary mechanism endowing glyphosate resistance in S. halepense from cropping fields in Argentina. To a lesser extent, reduced glyphosate leaf uptake has also been shown to be involved in glyphosate-resistant S. halepense.Fil: Vila Aiub, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Balbi, María C.. No especifíca;Fil: Distéfano, Ana J.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad de Buenos Aires; ArgentinaFil: Fernández, Luis. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Hopp, Esteban. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Universidad de Buenos Aires; ArgentinaFil: Yu, Qin. University of Western Australia; AustraliaFil: Powles, Stephen B.. University of Western Australia; Australi

    Acute effects of isotonic eccentric exercise on the neuromuscular function of knee extensors vary according to the motor task: impact on muscle strength profiles, proprioception and balance

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    [EN] Introduction: Eccentric exercise has often been reported to result in muscle damage, limiting the muscle potential to produce force. However, understanding whether these adverse consequences extend to a broader, functional level is of apparently less concern. In this study, we address this issue by investigating the acute and delayed effects of supramaximal isotonic eccentric exercise on neuromuscular function and motor performance of knee extensors during tasks involving a range of strength profiles, proprioception, and balance. Methods: Fifteen healthy volunteers (23.2 ± 2.9 years old) performed a unilateral isotonic eccentric exercise of the knee extensors of their dominant lower limb (4 × 10 reps at 120% of one Repetition Maximum (1RM)). The maximum voluntary isometric contraction (MVC), rate of force development (RFD), force steadiness of the knee extensors, as well as knee joint position sense and mediolateral (MLI) and anteroposterior stability (API) of the dominant lower limb, were measured pre-, immediately, and 24 h after the eccentric exercise. The EMG amplitude of the vastus medialis (VM) and biceps femoris (BF) were concomitantly evaluated. Results: MVC decreased by 17.9% immediately after exercise (P < 0.001) and remained reduced by 13.6% 24 h following exercise (P < 0.001). Maximum RFD decreased by 20.4% immediately after exercise (P < 0.001) and remained reduced by 15.5% at 24 h (P < 0.001). During the MVC, EMG amplitude of the VM increased immediately after exercise while decreasing during the RFD task. Both values returned to baseline 24 h after exercise. Compared to baseline, force steadiness during submaximal isometric tasks reduced immediately after exercise, and it was accompanied by an increase in the EMG amplitude of the VM. MLI and knee joint position sense were impaired immediately after isotonic eccentric exercise (P < 0.05). While MLI returned to baseline values 24 h later, the absolute error in the knee repositioning task did not. Discussion: Impairments in force production tasks, particularly during fast contractions and in the knee joint position sense, persisted 24 h after maximal isotonic eccentric training, revealing that neuromuscular functional outputs were affected by muscle fatigue and muscle damage. Conversely, force fluctuation and stability during the balance tasks were only affected by muscle fatigue since fully recovered was observed 24 h following isotonic eccentric exercise.SIThe author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was funded by the Portuguese Foundation for Science and Technology, IP, under project UID04045/2020. The Polytechnic of Guarda partly supported the research reported in this publication.ARB and AB are part of the Highly Qualified Human Resources Project, reference number CENTRO-04-3559-FSE-000162. MR-A acknowledges the financial support received from the Spanish Ministry of Universities through the Grants for the Requalification of the Spanish University System under the Postdoctoral Margarita Salas Programme (RSUC.UDC.MS09), funded by the European Union – Next Generation

    Successful outcomes of a new combined solution of hyaluronic acid, chondroitin sulfate and poloxamer 407 for submucosal injection: animal survival study

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    Background: and study aims Endoscopic resection requires use of submucosal injection. This study was conducted to assess efficacy and impact on early healing of hyaluronic acid combined with chondroitin sulfate and poloxamer 407 (Ziverel) when used as a solution for submucosal injection. Materials: and methods Prospective and comparative study of gastric endoscopic mucosal resection (EMR) with three groups of two Yorkshire pigs. Six submucosal cushions were created in each animal by injecting 2 mL of Ziverel (Group 1) or succinylated gelatin (SG) (Group 2), enabling 12 EMR in each group. Submucosal cushions were created with Ziverel in Group 3, without resection. Electrosurgery unit settings were the same in all cases. EMR defects and injection sites were marked with clips. The animals were sacrificed 7 days later. EMR specimen size and duration of procedure were recorded. EMR specimens and EMR scars and injection sites were evaluated by a blinded pathologist. Results: We successfully performed 24 EMR (15 en-bloc and 9 piecemeal, without differences between groups 1 and 2). Mean EMR specimen dimensions were significantly larger in Group 1 (median 19 mm, range 6 - 40 vs 16.6 mm, range 5‑25; P = 0.019), without changing the electrocautery unit settings. Blinded histopathologist assessment of EMR specimens showed less fibrosis in the submucosa and a trend to fewer cautery artifacts with Ziverel and did not identify any significant differences in early healing of resection sites. Conclusion: The combination of Ziverel enables EMR and does not negatively affect early healing

    Skeletal muscle myogenesis is regulated by G protein-coupled receptor kinase 2

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    This is a pre-copyedited, author-produced pdf of an article accepted for publication in Journal of Molecular Cell Biology following peer review. The version of record Journal of Molecular Cell Biology 6.4 (2014) is available online at: http://dx.doi.org/10.1093/jmcb/mju025G protein-coupled receptor kinase 2 (GRK2) is an important serine/threonine-kinase regulating different membrane receptors and intracellular proteins. Attenuation of Drosophila Gprk2 in embryos or adult flies induced a defective differentiation of somatic muscles, loss of fibers, and a flightless phenotype. In vertebrates, GRK2 hemizygous mice contained less but more hypertrophied skeletal muscle fibers than wild-type littermates. In C2C12 myoblasts overexpression of a GRK2 kinase-deficient mutant (K220R) caused precocious differentiation of cells into immature myotubes, which were wider in size and contained more fused nuclei, while GRK2 overexpression blunted differentiation. Moreover, p38MAPK and Akt pathways were activated at an earlier stage and to a greater extent in K220R-expressing cells or upon kinase downregulation, while the activation of both kinases was impaired in GRK2- overexpressing cells. The impaired differentiation and fewer fusion events promoted by enhanced GRK2 levels were recapitulated by a p38MAPK mutant, which was able to mimic the inhibitory phosphorylation of p38MAPK by GRK2, whereas the blunted differentiation observed in GRK2-expressing clones was rescued in the presence of a constitutively active upstream stimulator of the p38MAPK pathway. These results suggest that balanced GRK2 function is necessary for a timely and complete myogenic process.This work was supported by Grants BFU2008-04043 (to M.L. and S.F.-V.), SAF2012-3618 (to S.F.-V.), and SAF2011-23800 (to F.M.) from Ministerio de Economía y Competitividad, Spain; S2010/BMD-2332 (INDISNET) from Comunidad de Madrid, Spain (to F.M.); CIBER de Diabetes y Enfermedades Metabólicas Asociadas and The Cardiovascular Network (RD06- 0014/0037 and RD12/0042/0012) from Ministerio Sanidad y Consumo-Instituto Carlos III, Spain (to F.M.); UAM-Banco de Santander (to C.M.); BFU2010-14884 (to M.R.-G.). S.F.-V. is recipient of a ‘Miguel Servet’ tenure track program (CP10/00438) co-financed by the European Regional Development Fund (ERDF). We also acknowledge the support of COST Action BM0602 from the European Commission (to M.L.) and institutional support from Fundación Ramón Arece

    Cistinosis en pacientes adolescentes y adultos: Recomendaciones para la atención integral de la cistinosis

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    ResumenIntroducciónLa cistinosis es una enfermedad lisosomal minoritaria de expresión sistémica con especial afectación renal y oftalmológica, en la que los pacientes inician terapia renal sustitutiva en la primera década de la vida en ausencia de tratamiento. El pronóstico de la cistinosis depende del diagnóstico precoz, la pronta instauración del tratamiento con cisteamina y el buen cumplimiento terapéutico. La progresión de la enfermedad renal y de las complicaciones extrarrenales y una menor supervivencia, son más acentuadas en pacientes no adherentes.ObjetivoEl objetivo de este trabajo fue la elaboración de unas recomendaciones para la atención integral de la cistinosis y la transición del adolescente a la medicina del adulto, basadas en la experiencia clínica, con el fin de reducir el impacto de la enfermedad y mejorar la calidad de vida y el pronóstico del paciente.MétodoBúsqueda bibliográfica y reuniones de consenso de un equipo multidisciplinar de expertos en la práctica clínica con pacientes afectos de cistinosis (Grupo T-CiS.bcn), procedentes de 5 hospitales localizados en Barcelona.ResultadosEl documento recoge recomendaciones específicas y necesarias para el diagnóstico, tratamiento y seguimiento multidisciplinar de la cistinosis en las siguientes áreas: nefrología, diálisis, trasplante renal, oftalmología, endocrinología, neurología, laboratorio, consejo genético, enfermería y farmacia.ConclusionesDisponer de un documento de referencia para la atención integral de la cistinosis constituye una herramienta de soporte para los profesionales de la salud que asisten a estos pacientes. Los principales pilares en los que se sustenta son: a) el enfoque multidisciplinar, b) la adecuada monitorización de la enfermedad y control de los niveles de cistina intraleucocitarios, c) la importancia de la adherencia al tratamiento con cisteamina y d) la promoción del autocuidado del paciente mediante programas de educación en la enfermedad. Todo ello conducirá, en una segunda fase, a la elaboración de un modelo de transición coordinado entre los servicios de pediatría y de adultos que contemple las necesidades específicas de la cistinosis.AbstractIntroductionCystinosis is a rare lysosomal systemic disease that mainly affects the kidney and the eye. Patients with cystinosis begin renal replacement therapy during the first decade of life in absence of treatment. Prognosis of cystinosis depends on early diagnosis, and prompt starting and good compliance with cysteamine treatment. Kidney disease progression, extra-renal complications and shorter life expectancy are more pronounced in those patients that do not follow treatment.The objective of this work was to elaborate recommendations for the comprehensive care of cystinosis and the facilitation of patient transition from paediatric to adult treatment, based on clinical experience. The goal is to reduce the impact of the disease, and to improve patient quality of life and prognosis.MethodsBibliographic research and consensus meetings among a multidisciplinary professional team of experts in the clinical practice, with cystinotic patients (T-CiS.bcn group) from 5 hospitals located in Barcelona.ResultsThis document gathers specific recommendations for diagnosis, treatment and multidisciplinary follow-up of cystinotic patients in the following areas: nephrology, dialysis, renal transplant, ophthalmology, endocrinology, neurology, laboratory, genetic counselling, nursing and pharmacy.ConclusionsA reference document for the comprehensive care of cystinosis represents a support tool for health professionals who take care of these patients. It is based on the following main pillars: a) a multi-disciplinary approach, b) appropriate disease monitoring and control of intracellular cystine levels in leukocytes, c) the importance of adherence to treatment with cysteamine, and d) the promotion of patient self-care by means of disease education programmes. All these recommendations will lead us, in a second phase, to create a coordinated transition model between paediatric and adult care services which will cover the specific needs of cystinosis

    Indicadores de observación y competencias en el Prácticum Grados Infantil y Primaria: centro y aula

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    El trabajo que se presenta está enmarcado en la RED Diseño y desarrollo de una Guía observacional para la implementación del Prácticum de los Grados de Infantil y Primaria, dentro del Programa de REDES de investigación en docencia universitaria del ICE/ Universidad de Alicante. Tomando como referencia las competencias de la asignatura Prácticum que se desarrolla a lo largo de varios periodos, se han establecido una serie de indicadores de observación a nivel de centro y de aula, que nos permitan configurar una Guía observacional como instrumento de observación y análisis de la realidad escolar durante el desarrollo del Prácticum. La metodología utilizada se ha centrado en el trabajo colaborativo de los integrantes de la RED, desde sus diversas experiencias y aportaciones en sus campos profesionales. Los primeros resultados han determinado los seis grandes bloques de indicadores de esta Guía: la organización y gestión del centro; la organización y gestión del aula; el clima del aula y el alumnado; el planteamiento metodológico y la evaluación; la atención a las n.e.e.; y la participación de las familias

    Un estudio en RED: Guía observacional en el Prácticum Grados Infantil y Primaria

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    El trabajo que se presenta está enmarcado en la RED Diseño y desarrollo de una Guía observacional para la implementación del Prácticum de los Grados de Infantil y Primaria, dentro del Programa de REDES de investigación en docencia universitaria del ICE/ Universidad de Alicante. Tomando como referencia las competencias de la asignatura Prácticum que se desarrolla a lo largo de varios periodos, se han establecido una serie de indicadores de observación a nivel de centro y de aula, que nos permitan configurar una Guía observacional como instrumento de observación y análisis de la realidad escolar durante el desarrollo del Prácticum. La metodología utilizada se ha centrado en el trabajo colaborativo de los integrantes de la RED, desde sus diversas experiencias y aportaciones en sus campos profesionales. Los primeros resultados han determinado los seis grandes bloques de indicadores de esta Guía: la organización y gestión del centro; la organización y gestión del aula; el clima del aula y el alumnado; el planteamiento metodológico y la evaluación; la atención a las n.e.e.; y la participación de las familias

    The ins and outs of the BCCAo model for chronic hypoperfusion: a multimodal and longitudinal MRI approach

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    Cerebral hypoperfusion induced by bilateral common carotid artery occlusion (BCCAo) in rodents has been proposed as an experimental model of white matter damage and vascular dementia. However, the histopathological and behavioral alterations reported in this model are variable and a full characterization of the dynamic alterations is not available. Here we implemented a longitudinal multimodal magnetic resonance imaging (MRI) design, including time- of-flight angiography, high resolution T1-weighted images, T2 relaxometry mapping, diffusion tensor imaging, and cerebral blood flow measurements up to 12 weeks after BCCAo or sham-operation in Wistar rats. Changes in MRI were related to behavioral performance in executive function tasks and histopathological alterations in the same animals. MRI frequently (70%) showed various degrees of acute ischemic lesions, ranging from very small to large subcortical infarctions. Independently, delayed MRI changes were also apparent. The patterns of MRI alterations were related to either ischemic necrosis or gliosis. Progressive microstructural changes revealed by diffusion tensor imaging in white matter were confirmed by observation of myelinated fiber degeneration, including severe optic tract degeneration. The latter interfered with the visually cued learning paradigms used to test executive functions. Independently of brain damage, BCCAo induced progressive arteriogenesis in the vertebrobasilar tree, a process that was associated with blood flow recovery after 12 weeks. The structural alterations found in the basilar artery were compatible with compensatory adaptive changes driven by shear stress. In summary, BCCAo in rats induces specific signatures in multimodal MRI that are compatible with various types of histological lesion and with marked adaptive arteriogenesis
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