Arquitectura Computacional para la Inferencia deuna CNN Cuantizada para Detectar FibrilaciónAuricular

Atrial Fibrillation is a common cardiac arrhythmia, which is characterized by an abnormal heartbeat rhythm that can be life-threatening. Recently, researchers have proposed several Convolutional Neural Networks (CNNs) to detect Atrial Fibrillation. CNNs have high requirements on computing and memory resources, which usually demand the use of High Performance Computing (eg, GPUs). This high energy demand is a challenge for portable devices. Therefore, efficient hardware implementations are required. We propose a computational architecture for the inference of a Quantized Convolutional Neural Network (Q-CNN) that allows the detection of the Atrial Fibrillation (AF). The architecture exploits data-level parallelism by incorporating SIMD-based vector units, which is optimized in terms of computation and storage and also optimized to perform both the convolutional and fully connected layers. The computational architecture was implemented and tested in a Xilinx Artix-7 FPGA. We present the experimental results regarding the quantization process in a different number of bits, hardware resources, and precision. The results show an accuracy of 94% accuracy for 22-bits. This work aims to be the basis for the future implementation of a portable, low-cost, and high-reliability device for the diagnosis of Atrial Fibrillation.La fibrilación auricular es una arritmia cardíaca común, que se caracte-riza por un ritmo cardíaco anormal que puede poner en peligro la vida.Recientemente, se han propuesto varias Redes Neuronales Convoluciona-les (CNNs, por sus siglas en inglés) para detectar la fibrilación auricular.Las CNN tienen altos requisitos de recursos informáticos y de memoria,lo que generalmente demanda el uso Computación de Altro Rendimientocomo por ejemplo GPUs. Esta alta demanda de energía es un desafío pa-ra los dispositivos portátiles. Por lo tanto, se requieren implementacionesde hardware eficientes. Proponemos una arquitectura computacional pa-ra la inferencia de una Red Neural Convolucional Cuantizada (Q-CNN)que permite la detección de la Fibrilación Auricular (FA). La arquitecturaaprovecha el paralelismo a nivel de datos, incorporando unidades vecto-riales basadas en SIMD, que están optimizadas en términos de cálculoy almacenamiento. El diseño también se optimizó para realizar tanto lascapas convolucionales como las capas completamente conectadas. La ar-quitectura computacional se implementó y probó en una FPGA XilinxArtix-7. Presentamos los resultados experimentales con respecto al proce-so de cuantización en un número diferente de bits, recursos de hardwarey precisión. Los resultados muestran una precisión del 94 % para 22 bits.Este trabajo pretende ser la base para la futura implementación de undispositivo portátil, de bajo costo y alta confiabilidad para el diagnósticode Fibrilación Auricular

Effect of the concentration of magnetite on the structure, electrical and magnetic properties of a polyester resin-based composite

Se reporta el efecto de la concentración de polvos de magnetita (Fe3O4) sobre las propiedades eléctricas y magnéticas de un material compuesto a base de resina de poliéster termoestable. Las muestras se elaboraron mediante el método de colado manual en concentraciones de: 60-40, 70-30, 80-20, 90-10 y 100-0 (% en peso), donde la fase mayoritaria es la resina y la minoritaria los óxidos de Fe3O4. La estructura cristalina se estudió usando la técnica de difracción de rayos X y la caracterización superficial tuvo lugar a través de la técnica de microscopía electrónica de barrido. Se midió la respuesta eléctrica por medio de curvas de polarización eléctrica en función del campo eléctrico y de resistividad eléctrica volumétrica a través de un electrómetro. La respuesta magnética se determinó mediante curvas de magnetización en función de la intensidad de campo magnético aplicado y en función de la temperatura. El análisis estructural indica que el porcentaje de cristalinidad aumenta a medida que se adiciona la concentración de Fe3O4 a las muestras. La caracterización eléctrica del material evidencia que la resistividad volumétrica disminuye con el incremento de magnetita, mostrando una transición aislante-conductor, con valores de la constante dieléctrica cada vez mayores. La caracterización magnética evidencia un aumento lineal de la magnetización de saturación y del momento magnético en función de la cantidad de magnetita adicionada a la matriz polimérica, mientras que la coercitividad evidencia comportamientos de materiales magnéticos blandos tanto en T˃TV como en T<TV, donde TV representa la temperatura de Verwey.This study reports the effect of the concentration of magnetite powders (Fe3O4) on the electrical and magnetic properties of a resin-based composite of thermoset polyester. The samples were prepared by the casting method at different concentrations: 60-40, 70-30, 80-20, 90-10 and 100-0 (% in weight), where the primary phase was resin and the secondary, Fe3O4 powders. The crystalline structure was studied using X-ray diffraction and surface characterization was carried out applying the scanning electron microscopy technique. The electrical response was measured by electric polarization curves as a function of the electric field; and the volumetric electrical resistivity, by an electrometer. The magnetic response was determined by magnetization curves as a function of temperature and intensity of the applied magnetic field. The structural analysis indicates that crystallinity increases as higher concentrations of Fe3O4 are added to the samples. The electrical characterization of the material reveals that the volumetric resistivity decreases as the content of magnetite increases. These reactions indicate an insulation-conductor transition with increasing dielectric constant values. The magnetic characterization presents a linear increase of the saturation of magnetization and magnetic moment as a function of the amount of magnetite added to the polymer matrix, whereas the coercivity shows behaviors of soft magnetic materials for T ˃ Tv and for T < Tv, where Tv represents the temperature of Verwey

Expedición cangrejo negro : informe técnico

El huracán Iota que pasó por las islas de providencia y Santa catalina el 16 de noviembre de 2020 produjo efectos importantes en los ecosistemas de las islas, así como en los servicios que estos ofrecen a las comunidades locales y que dan lugar a un atractivo turístico que se constituye en la principal actividad económica de las islas. Este trabajo corresponde a un esfuerzo por identificar áreas importantes para la prestación de los servicios ecosistémicos (SSE) en especial aquellas que pudieron haber resultado especialmente afectadas como resultado de Iota, para tal fin se aborda un enfoque basado en el análisis de datos geoespaciales, apoyado por la consulta de información secundaria. La revisión de la información secundaria permitió identificar SSE relevantes en la isla fundamentalmente relacionados con protección frente a desastres naturales y servicios de provisión y regulación hídrica, mientras que los análisis espaciales permitieron identificar cuencas importantes frente a estos servicios como Freshwater, Bailey, Bowden y Santa Catalina Sur, los análisis de imágenes satelitales por su parte permitieron identificar áreas afectadas por la pérdida de vegetación y acumulación de biomasa.Bogot

La prueba: teoría y práctica

Especialistas de talla mundial discurren en torno al núcleo básico de la administración de la justicia: la prueba, un tema fundamental que —precisamente por su carácter basilar— tiende a ser pasado por alto o a revisarse de manera superficial. En esta obra colectiva, se estudian —desde una perspectiva tanto conceptual como práctica— problemas fundamentales en torno a la prueba, desde diferentes puntos de vista que se soportan en diversas áreas del conocimiento como la filosofía, la epistemología, la psicología, entre otras. Modestia aparte, no es fortuito que en el prólogo del libro Bujosa Vadell declare que “está llamado a ser obra de cabecera para los juristas que, desde la academia y desde el foro, se preocupan por una conducción adecuada de la actividad probatoria”. Así pues, académicos, juristas, abogados litigantes y jueces tienen a su disposición la décima segunda entrega del Grupo de Investigaciones en Derecho Procesal, de la Universidad de Medellín, reconocido mundialmente por su compromiso y dedicación a la hora de coordinar esta ya tradicional serie de libros de investigación en derecho procesal.https://catalogo.udem.edu.co/la-prueba-teoria-y-practica--derecho-procesal-civil.html#.XbdVx-gzbc

Polyester urethane urea (PEUU) functionalization for enhanced anti-thrombotic performance: advancing regenerative cardiovascular devices through innovative surface modifications

Introduction: Thrombogenesis, a major cause of implantable cardiovascular device failure, can be addressed through the use of biodegradable polymers modified with anticoagulating moieties. This study introduces a novel polyester urethane urea (PEUU) functionalized with various anti-platelet deposition molecules for enhanced antiplatelet performance in regenerative cardiovascular devices.Methods: PEUU, synthesized from poly-caprolactone, 1,4-diisocyanatobutane, and putrescine, was chemically oxidized to introduce carboxyl groups, creating PEUU-COOH. This polymer was functionalized in situ with polyethyleneimine, 4-arm polyethylene glycol, seleno-L-cystine, heparin sodium, and fondaparinux. Functionalization was confirmed using Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. Bio-compatibility and hemocompatibility were validated through metabolic activity and hemolysis assays. The anti-thrombotic activity was assessed using platelet aggregation, lactate dehydrogenase activation assays, and scanning electron microscopy surface imaging. The whole-blood clotting time quantification assay was employed to evaluate anticoagulation properties.Results: Results demonstrated high biocompatibility and hemocompatibility, with the most potent anti-thrombotic activity observed on pegylated surfaces. However, seleno-L-cystine and fondaparinux exhibited no anti-platelet activity.Discussion: The findings highlight the importance of balancing various factors and addressing challenges associated with different approaches when developing innovative surface modifications for cardiovascular devices

Expedición Colombia BIO. Biodiversidad y conservación de los sistemas subterráneos y ambientes exocársticos asociados en El Peñón, Santander, Colombia

La primera Expedición de Biodiversidad Colombia BIO - Instituto Humboldt se llevó a cabo en el municipio del Peñón en Santander, con el objetivo de abordar la diversidad de fauna y flora en los ecosistemas subterráneos (endocársticos) y los ambientes superficiales (exocársticos) asociados a las cuevas.BogotáSubdirección de Investigacione

Neuroaxial anesthesia caused paraplegia: a case report

Patients who undergo; anesthesia, neuraxial analgesia, or some type of neuraxial blockage are exposed to multiple complications. 33-year-old male patient, suffers a femur fracture with a long oblique trace causing pain and functional limitation for movements. Surgical resolution is determined using neuraxial block at L2-L3 level, and intravenous sedation. During his postoperative follow-up, a decrease in strength was confirmed in the lower limbs with 0/5 on the Daniels scale, 100% sensitivity without sphincter control, steroids were prescribed along with magnetic resonance imaging and a neurosurgical evaluation was requested. The MRI shows bulging of the fibrous annulus that obliterates the epidural fat and makes contact with the thecal sac in the L5-S1 intervertebral disc level. The neurosurgery service prescribes rehabilitation sessions at home, electrostimulation and neuropathic medications. Patient was discharged with rehabilitation sessions at home and medical treatment. In his last consultation, an evaluation from the psychiatry department was requested for ideas of disability, hopelessness, fantasies of death without a suicide plan related to limitations and loss of functionality. Patient does not return to external follow-up, cannot be located

Chronic venous insufficiency: a review

Chronic venous insufficiency (CVI) comprises a complete spectrum of morphological and functional abnormalities of the venous system1 including any long-term functional and morphological alteration. CVI accounts for several abnormalities of the venous system. It is a highly prevalent disease that causes serious economic consequences, a decrease in the quality of life and can lead to serious complications. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to chronic venous insufficiency. The pathophysiology of chronic venous insufficiency begins with chronic venous hypertension and the dilation of the vessel, this leads to a series of pathological changes in the venous wall and surrounding tissues, in advanced stages of CVI, skin lesions are associated with an increased proliferation of skin capillaries and microcirculatory abnormalities that may be the result of an altered level of factors responsible for the angiogenic response, such as vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2) and angiostatin. In this review, updates on pathophysiology, clinic, diagnosis, classification and treatment of this disease are analyzed, with special emphasis on therapeutic options. Chronic venous insufficiency is a disease that affects the patient at several levels, mainly diminishing his/her quality of life. Currently there are various treatments ranging from habit modifications, pharmacological, to endovenous and surgical treatment.

Characteristics of Emergency Medicine Residency Programs in Colombia

Introduction: Emergency medicine (EM) is in different stages of development around the world. Colombia has made significant strides in EM development in the last two decades and recognized it as a medical specialty in 2005. The country now has seven EM residency programs: three in the capital city of Bogotá, two in Medellin, one in Manizales, and one in Cali. The seven residency programs are in different stages of maturity, with the oldest founded 20 years ago and two founded in the last two years. The objective of this study was to characterize these seven residency programs. Methods: We conducted semi-structured interviews with faculty and residents from all the existing programs in 2013–2016. Topics included program characteristics and curricula. Results: Colombian EM residencies are three-year programs, with the exception of one four-year program. Programs accept 3–10 applicants yearly. Only one program has free tuition and the rest charge tuition. The number of EM faculty ranges from 2–15. EM rotation requirements range from 11–33% of total clinical time. One program does not have a pediatric rotation. The other programs require 1–2 months of pediatrics or pediatric EM. Critical care requirements range from 4–7 months. Other common rotations include anesthesia, general surgery, internal medicine, obstetrics, gynecology, orthopedics, ophthalmology, radiology, toxicology, psychiatry, neurology, cardiology, pulmonology, and trauma. All programs offer 4–6 hours of protected didactic time each week. Some programs require Advanced Cardiac Life Support, Pediatric Advanced Life Support and Advanced Trauma Life Support, with some programs providing these trainings in-house or subsidizing the cost. Most programs require one research project for graduation. Resident evaluations consist of written tests and oral exams several times per year. Point-of-care ultrasound training is provided in four of the seven programs. Conclusion: As emergency medicine continues to develop in Colombia, more residency programs are expected to emerge. Faculty development and sustainability of academic pursuits will be critically important. In the long term, the specialty will need to move toward certifying board exams and professional development through a national EM organization to promote standardization across programs