394 research outputs found

    Scattering and absorption sections of Schwarzschild-anti de Sitter with quintessence

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    In this paper, we study the Schwarzschild-anti de Sitter black hole surrounded by quintessence. The critical values of the cosmological constant and the normalization factor are obtained. We described the event horizons and the extremal condition of the black hole surrounded by quintessence. Also, the effects of quintessence on the classical and semiclassical scattering cross-sections have been estimated. The absorption section is studied with the sinc approximation in the eikonal limit. This study considers the quintessence state parameter in the particular cases ω=−2/3\omega=-2/3 and ω=−1/2\omega=-1/2.Comment: arXiv admin note: substantial text overlap with arXiv:2103.0641

    DESIGN AND INTEGRATION OF A HUMAN-ROBOT PHYSICAL INTERACTION PLATFORM WITH PURPOSES OF MEDICAL DIAGNOSIS AND REHABILITATION OF UPPER LIMB

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    In this paper a human-robot physical interaction system with purposes of diagnosis and rehabilitation of upper limb is proposed.Anunderactuatedhaptic device with six degrees of freedom is used, with low inertia and low joint friction.Adaptive control technique is used for passive haptic guidance and active exploration, in order to compensate the dynamic uncertainty of the human operator in the loop.To validate the experimental platform, a procedure is established with three steps: i) knowledge of the haptic interface (interaction with the kinematic virtual environment), ii) navigation in a virtual pipe with changes in the geometric characteristics (verification of position, velocity, collisions and runtime), and iii) haptic guidance in a structured path based on a clinical protocol (study of convergence and energy).Environmental conditions such as temperature, humidity, lighting and noise are characterizedwith purposes to define experimental conditions.In this work, we assess based on the NASA-TLX protocol,the workload perception of simple temporal-spatial tasks

    DESIGN AND INTEGRATION OF A HUMAN-ROBOT PHYSICAL INTERACTION PLATFORM WITH PURPOSES OF MEDICAL DIAGNOSIS AND REHABILITATION OF UPPER LIMB

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    In this paper a human-robot physical interaction system with purposes of diagnosis and rehabilitation of upper limb is proposed.Anunderactuatedhaptic device with six degrees of freedom is used, with low inertia and low joint friction.Adaptive control technique is used for passive haptic guidance and active exploration, in order to compensate the dynamic uncertainty of the human operator in the loop.To validate the experimental platform, a procedure is established with three steps: i) knowledge of the haptic interface (interaction with the kinematic virtual environment), ii) navigation in a virtual pipe with changes in the geometric characteristics (verification of position, velocity, collisions and runtime), and iii) haptic guidance in a structured path based on a clinical protocol (study of convergence and energy).Environmental conditions such as temperature, humidity, lighting and noise are characterizedwith purposes to define experimental conditions.In this work, we assess based on the NASA-TLX protocol,the workload perception of simple temporal-spatial tasks

    Rutas Solidarias

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    En el Proyecto de Aplicación Profesional de Verano 2022, (PAP PROGRAMA DE SUSTENTABILIDAD SOCIOAMBIENTAL PARA EL DESARROLLO INCLUSIVO I) trabajamos como equipo en la creación de tres Rutas Solidarias en las comunidades del Valle de Mazatepec y sus alrededores. El objetivo principal es poder conectar a las personas con actividades que promuevan el turismo dentro de esta zona y generar mayor visibilidad, cuidando siempre el turismo ecológico y consciente. Las rutas están dirigidas a distintos perfiles; familiares, amigos, turísticos, entre otros, con el fin de acomodar las rutas a los gustos y posibilidades de las personas que desean vivir la experiencia. Las rutas incluyen parte del patrimonio cultural y natural del Valle de Mazatepec.ITESO, A.C

    Detection of open-pit mining zones by implementing spectral indices and image fusion techniques

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    This article aims to present the results of the application of different proposed spectral indices and image fusion techniques for the detection of open-pit mining zones, located to the north-east of Antioquia, Colombia; having as reference mining and no mining zones samples obtained from visual characterization of pictorial-morphological properties of the open-pit mining zones in the study area. This research used high resolution (UltraCam-D y RapidEye) and medium resolution (Landsat 8 LDCM) imagery, where the latter was defined as the main input for the application of the spectral indices and image fusion techniques. The development of the proposed methodological design and the statistical analysis of the images, presented the Brovey transformed image fusion technique -on its band 2-as the one with the highest discriminant potential for open-pit mining zone; the classification of the results were determined between the thresholds of pixel values from 0.3225 -defined as the discriminant breakpoint-to the maximum value of the mining group samples, corresponding to 0.5237.Se presentan los resultados de la aplicación de diferentes índices espectrales y técnicas de fusión de imágenes de sensores remotos propuestos para la detección de zonas mineras a cielo abierto, localizadas en el sector nor-oriental del departamento de Antioquia, Colombia, tomando como referencia muestras de minería y no minería, identificadas a partir de la caracterización visual de propiedades pictoricomorfológicas de zonas mineras a cielo abierto en el área de estudio, utilizando imágenes de alta resolución (UltraCam-D y Rapid Eye) y mediana resolución (Landsat 8 LDCM), estas últimas fueron definidas como el insumo principal para la aplicación de los índices espectrales y técnicas de fusión de imágenes. El desarrollo del diseño metodológico propuesto y el análisis estadístico de las imágenes, evidenciaron que la técnica de fusión de imágenes, transformada de Brovey -en su banda 2- presenta mayor potencial discriminante para la identificación de zonas mineras a cielo abierto; la clasificación de los resultados se determinó entre el rango de valores de pixel de 0.3225 -constituido como el punto de corte discriminante- hasta el valor máximo de las muestras del grupo de minería, correspondiente a 0.5237

    Identification of non-tuberculous mycobacteria isolated from opossum (Didelphis virginiana) lymph nodes and characterisation of lesions

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    The aim of this study was to investigate the presence of NTM in the lymph nodes of opossums (D. virginiana) and to characterise the microscopic changes in affected tissue. Retropharyngeal and tracheobronchial lymph nodes were collected postmortem from 18 opossums in the state of Colima, Mexico in 2013. The lymph nodes were also cultured for mycobacterial organisms and processed for histopathological examination. Bacteriological cultures yielded 5/18X100 (28%) isolates of NTM, which were subsequently identified as M. terrae, M. szulgai, M. gastri and M. asiaticum. Microscopic examination of the affected nodes revealed a necrotic granulomatous lymphadenitis (3/60%) composed of histiocytes, epithelioid cells and giant cells with intralesional alcoholresistant acid bacteria. An association between the sex of the opossum and the presence of NTM was observed. To our knowledge, this is the first report of NTM isolation in opossums with granulomatous lymphadenitis in Mexico

    A Case of Acute Pemphigus Vulgaris Relapses Associated with Cocaine Use and Review of the Literature

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    Pemphigus is a bullous autoimmune disease that affects the skin and mucous membranes. It is very difficult to establish the etiology and the triggering factors that influence reactivations in pemphigus vulgaris (PV). The case of a 33-year-old male with chronic history of intranasal cocaine consumption is presented in this report. We present the clinical case of the patient, followed for a total of 86 weeks, with ten relapses secondary to probable cocaine use. The patient was admitted to the emergency department after presenting polymorphic dermatosis characterized by blisters, vesicles, and excoriations extending from the oral cavity to the thorax, and to the inguinal and genital regions, affecting approximately 35 % of the body surface area with a score of 56 on the Pemphigus Skin Disorder Index. Skin biopsies were compatible with PV diagnosis. The patient had clinical improvement with a combination of methylprednisolone 500 mg intravenously (IV) and cyclophosphamide 500 mg IV every 15 days, along with prednisone 50 mg orally (PO) q24 h and mycophenolic acid 500 mg PO q6 h. Persistent cocaine use is highly likely to be the factor triggering lesion reactivation and responsible for the torpid evolution. We cannot definitively conclude whether the change from azathioprine to mycophenolic acid after the tenth relapse was the adjuvant medication responsible for the end of the consolidation phase and complete remission on therapy. This case study could potentially serve as a guide for management of patients who continuously persist with cocaine use, leading to a clinical picture refractory to multiple therapeutic schemes

    Acoustic and Thermal Analysis of Food

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    Exploring the food acoustic features can help to understand and effectively apply some preservation treatments that extend their expiration date. The food composition and properties are crucial issues in their acoustic behavior when stimulated with acoustic waves. If these waves are varied in frequency and intensity, the temperature of food could be affected facilitating the moisture removal or degrading its nutritional condition. Therefore, we presented a guide to determine and apply the most influential spectral component of ultrasound waves on apple and tomato when dehydrated in an ultrasound-assisted dehydration system. In this guide, applying the finite element method, we study, simulate, and analyze the acoustic and thermic behavior of apple and tomato inside a chamber when radiated with acoustic waves at (1 Hz, 1 MHz) by using up to three piezoelectric transducers. From the physical parameters defined in the simulation environment for apple and tomato, we find the relevant spectral components that can produce temperature changes in each food sample considering the radiation time and the food sample location. This work represents an analysis guide that allows for determining the best conditions for the acoustic radiation of foods, avoiding their structural and nutritional damage, and seeking the design of energy-efficient processes

    TNF-α and IL-10 downregulation and marked oxidative stress in Neuromyelitis Optica

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    <p>Abstract</p> <p>Background</p> <p>Neuromyelitis optica is a central nervous system demyelinating and inflammatory syndrome. The objective of this study is to identify cytokines related to the cellular immune response as well as blood brain barrier integrity and oxidative stress.</p> <p>Methods</p> <p>We performed a molecular characterization of cellular immune response and oxidative stress in serum from relapsing-NMO (R-NMO) patients and established the correlations between the clinical measurements and molecular parameters using the Bayesian approach.</p> <p>Serum samples from 11 patients with R-NMO diagnosed according to Wingerchuk criteria and matched in terms of age, gender and ethnicity with the healthy controls were analyzed. The levels of TNF-<it>α</it>, IFN-<it>γ</it>, IL-10, MMP-9, TIMP-1 and oxidative stress markers: malondialdehyde, advanced oxidation protein products, peroxidation potential, superoxide dismutase, catalase, and total hydroperoxides were measured.</p> <p>Results</p> <p>We found almost undetectable levels of TNF-<it>α</it>, a decreased production of IL-10 and a significant up-regulation of every oxidative stress biomarker studied. The insufficient production of TNF-<it>α </it>and IL-10 in R-NMO patients, which are two important players of T cell mediated immunoregulation, suggest an effector – regulator imbalance. The overproduction of oxygen reactive species as a consequence of the chronic inflammatory milieu is reflected on the excess of oxidative damage mediators detected. Furthermore, Multidimensional Scaling and a Bayesian linear regression model revealed a significant linear dependence between Expanded Disability Status Scale Kurtzke and TIMP-1; pointing to a possible predictive or prognostic value of this clinical-molecular relationship.</p> <p>Conclusion</p> <p>These results suggest that there is a breakdown in immunoregulatory mechanisms and noteworthy pro-oxidant environment contributing to NMO pathogenesis.</p
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