Enseñanza-aprendizaje en la clase de Educación Física

Analyzing and understanding the components of the teaching-learning process (E-A) in the Physical Education class carried out among teachers and schoolchildren of an educational Institution in Medellin, is the intention of this qualitative research and with the particularistic ethnographic approach, it allowed to demonstrate through from the voices of the participants their perceptions about the subject in question. The information obtained was collected through investigative techniques such as: Participant observation, interviews and workshops.The analysis was carried out under open and axial coding, in the category of the process methodology (E-A). As a result of the inquiry, it became clear that in the Physical Education class the teaching task is concreted, understood as an integrality between knowledge and experiences, where the task must have: a start-planning, a development-teaching-learning strategies and an end-evaluation.The moments and spaces for the planning should be according to the objectives and needs of the students established in a curricular design, during the development of the class the teacher must have clear the planned objectives, which should be his methodological tools for the adequate orientation and pertinent of the subject, and to finalize the formative process, it is pertinent to clarify the elements developed in the session that will be valued at the end of each meeting, which serve as inputs for the evaluative moment. The findings in this work account for biased visions during the construction of planning as its execution, as well as the different ways of evaluating the processes, which suggests a new investigation towards the methodological development of teaching.Analizar y comprender los componentes del proceso de enseñanza-aprendizaje  (E-A) en la clase de Educación Física realizada entre docentes y escolares de una institución educativa de Medellín, es la intención de esta investigación cualitativa y con el enfoque etnográfico particularista, permitió evidenciar a través de las voces de los participantes sus percepciones sobre el tema en cuestión. La información obtenida se recolecto a través de las técnicas investigativas tales como: Observación participante, entrevistas y talleres.    El análisis se realizó bajo codificación abierta y axial, en la categoría de la metodología del proceso (E-A). Como resultado de la indagación, quedo claro que en la clase de Educación Física se concreta el quehacer docente, entendido como una integralidad entre saberes y vivencias, donde el quehacer debe tener: un inicio -la planeación, un desarrollo- las estrategias de enseñanza aprendizaje y un final- la evaluación.Los momentos y espacios para la planeación deberían ser de acuerdo a los objetivos y necesidades de los escolares establecidos en un diseño curricular, durante el desarrollo de la clase el docente debe tener claro los objetivos planeados, cuales debería ser sus herramientas metodológicas para la orientación adecuada y pertinente de la asignatura, y para finalizar el proceso formativo, es pertinente clarificar los elementos desarrollados en la sesión que serán valorados al finalizar cada encuentro, que sirven de insumos para el  momento evaluativo.Los hallazgos en este trabajo dan cuenta de visiones parcializadas durante la construcción de la planeación como su ejecución, así mismo de las diferentes formas de evaluar los procesos, lo que deja entrever una nueva indagación hacia el desarrollo metodológico de la enseñanza

A parametric model for analysing atherosclerotic arteries: On the FSI coupling

There are many evidences that coronary plaque is not only dependent on the formation and progression of atherosclerosis, but also on the vascular remodelling response. If the local wall shear stress is low, a proliferative plaque may develop. Local inflammatory response will stimulate the formation of a plaque prone to rupture with superimposed thrombus formation (vulnerable plaque). Furthermore, the role of the wall shear stress in the genesis and the development of atherosclerotic diseases has been recently intensively investigated, examining its relationship with the presence of lesions and the intima media thickness. Due to the important role of pulsating blood flow, pressure and hemodynamics factors in atheroma growth, a Fluid Structure Interaction (FSI) parametric study of a 3D atherosclerotic artery has been carried out, with aim of studying the main geometrical risk factors in terms of plaque vulnerability

Influence of a commercial antithrombotic filter on the caval blood flow during neutra and valsalva maneuver

Anticoagulants are the treatment of choice for pulmonary embolism. When these fail or are contraindicated, vena cava filters are effective devices for preventing clots from the legs from migrating to the lung. Many uncertainties exist when a filter is inserted, especially during physiological activity such as normal breathing and the Valsalva maneuver. These activities are often connected with filter migration and vena cava damage due to the various related vein geometrical configurations. In this work, we analyzed the response of the vena cava during normal breathing and Valsalva maneuver, for a healthy vena cava and after insertion of a commercial Günther-Tulip® filter. Validated computational fluid dynamics (CFD) and patient specific data are used for analyzing blood flow inside the vena cava during these maneuvers. While during normal breathing, the vena cava flow can be considered almost stationary with a very low pressure gradient, during Valsalva the extravascular pressure compresses the vena cava resulting in a drastic reduction of the vein section, a global flow decrease through the cava but increasing the velocity magnitude. This change in the section is altered by the presence of the filter which forces the section of the vena cava before the renal veins to keep open. The effect of the presence of the filter is investigated during these maneuvers showing changes in wall shear stress and velocity patterns

In vitro comparison of Günther Tulip and Celect filters. Testing filtering efficiency and pressure drop

In this study, the trapping ability of the Günther Tulip and Celect inferior vena cava filters was evaluated. Thrombus capture rates of the filters were tested in vitro in horizontal position with thrombus diameters of 3 and 6. mm and tube diameter of 19. mm. The filters were tested in centered and tilted positions. Sets of 30 clots were injected into the model and the same process was repeated 20 times for each different condition simulated. Pressure drop experienced along the system was also measured and the percentage of clots captured was recorded. The Günther Tulip filter showed superiority in all cases, trapping almost 100% of 6. mm clots both in an eccentric and tilted position and trapping 81.7% of the 3. mm clots in a centered position and 69.3% in a maximum tilted position. The efficiency of all filters tested decreased as the size of the embolus decreased and as the filter was tilted. The injection of 6 clots raised the pressure drop to 4.1. mmHg, which is a reasonable value that does not cause the obstruction of blood flow through the system

Microstructural quantification of collagen fiber orientations and its integration in constitutive modeling of the porcine carotid artery

Background Mechanical characteristics of vascular tissue may play a role in different arterial pathologies, which, amongst others, requires robust constitutive descriptions to capture the vessel wall’s anisotropic and non-linear properties.Specifically, the complex 3D network of collagen and its interaction with other structural elements has a dominating effect of arterial properties at higher stress levels.The aim of this study is to collect quantitative collagen organization as well as mechanical properties to facilitate structural constitutive models for the porcine carotid artery.This helps the understanding of the mechanics of swine carotid arteries, being a standard in clinical hypothesis testing, in endovascular preclinical trials for example. Method Porcine common carotid arteries (n = 10) were harvested and used to (i) characterize the collagen fiber organization with polarized light microscopy, and (ii) the biaxial mechanical properties by inflation testing.The collagen organization was quantified by the Bingham orientation density function (ODF), which in turn was integrated in a structural constitutive model of the vessel wall.A one-layered and thick-walled model was used to estimate mechanical constitutive parameters by least-square fitting the recorded in vitro inflation test results.Finally, uniaxial data published elsewhere were used to validate the mean collagen organization described by the Bingham ODF. Results Thick collagen fibers, i.e.the most mechanically relevant structure, in the common carotid artery are dispersed around the circumferential direction.In addition, almost all samples showed two distinct families of collagen fibers at different elevation, but not azimuthal, angles.Collagen fiber organization could be accurately represented by the Bingham ODF (¿1,2,3=[13.5,0.0,25.2] and ¿1,2,3=[14.7,0.0,26.6]; average error of about 5%), and their integration into a structural constitutive model captured the inflation characteristics of individual carotid artery samples.Specifically, only four mechanical parameters were required to reasonably (average error from 14% to 38%) cover the experimental data over a wide range of axial and circumferential stretches.However, it was critical to account for fibrilar links between thick collagen fibers.Finally, the mean Bingham ODF provide also good approximation to uniaxial experimental data. Conclusions The applied structural constitutive model, based on individually measured collagen orientation densities, was able to capture the biaxial properties of the common carotid artery. Since the model required coupling amongst thick collagen fibers, the collagen fiber orientations measured from polarized light microscopy, alone, seem to be insufficient structural information. Alternatively, a larger dispersion of collagen fiber orientations, that is likely to arise from analyzing larger wall sections, could have had a similar effect, i.e. could have avoided coupling amongst thick collagen fibers.Peer ReviewedPostprint (author's final draft

A nonparametric control chart based on the Mann-Whitney statistic

Nonparametric or distribution-free charts can be useful in statistical process control problems when there is limited or lack of knowledge about the underlying process distribution. In this paper, a phase II Shewhart-type chart is considered for location, based on reference data from phase I analysis and the well-known Mann-Whitney statistic. Control limits are computed using Lugannani-Rice-saddlepoint, Edgeworth, and other approximations along with Monte Carlo estimation. The derivations take account of estimation and the dependence from the use of a reference sample. An illustrative numerical example is presented. The in-control performance of the proposed chart is shown to be much superior to the classical Shewhart $\bar{X}$ chart. Further comparisons on the basis of some percentiles of the out-of-control conditional run length distribution and the unconditional out-of-control ARL show that the proposed chart is almost as good as the Shewhart $\bar{X}$ chart for the normal distribution, but is more powerful for a heavy-tailed distribution such as the Laplace, or for a skewed distribution such as the Gamma. Interactive software, enabling a complete implementation of the chart, is made available on a website.Comment: Published in at http://dx.doi.org/10.1214/193940307000000112 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Methodology to calibrate the dissection properties of aorta layers from two sets of experimental measurements

Aortic dissection is a prevalent cardiovascular pathology that can have a fatal outcome. However, the mechanisms that trigger this disease and the mechanics of its progression are not fully understood. Computational models can help understand these issues, but they need a proper characterisation of the tissues. Therefore, we propose a methodology to obtain the dissection parameters of all layers in aortic tissue via the computational modelling of two different delamination tests: the peel and mixed tests. Both experimental tests have been performed in specimens of porcine aorta, where the intima-media and media-adventitia interfaces, as well as the medial layer, were dissected. These two tests have been modelled using a cohesive zone formulation for the separating interface and a hyperelastic anisotropic material model via an implicit static analysis. The dissection properties of each interface have been calibrated by reproducing the force-displacement curves obtained in the experimental tests. The values of peak and mean force of the experiments were fitted with an error below 10%. With this methodology, we intend to contribute to the development of reliable numerical tools for simulating aortic dissection and aortic aneurysm rupture. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Numerical and experimental study of the fluid flow through a medical device

The purpose of this paper is to verify a commercial software based fluid–structure interaction scheme for the inferior vena cava. Vena cava deep thrombosis (TVP) is a potentially deathly disease consequent to pulmonary thromboembolism (TEP). TEP consist in the obstruction of the pulmonary artery due to a blood clot traveling in the cardiovascular system and is treated with anticoagulants and inferior vena cava filters. Flow fields along the vena cava and an antithrombus filter were studied and compared with a Particle Image Velocimetry (PIV) based model to validate the numerical model. The results show that the fluid–structure interaction (FSI) models are valid and can be used to study the deformations in the inferior vena cava wall using patient-specific geometries