1,526 research outputs found
Propuesta de rediseño de procesos para la adaptación de un sistema ERP en la empresa Metalmecánica arcos Ltda.
Ingeniero (a) IndustrialPregrad
Efecto citotóxico de fosfolipasas A2 del veneno de Crotalus durissus cumanensis de Colombia
Introduction. Snake venoms are an important source of proteins and peptides, which display various
biological activities such as antibacterial, antiparasitic, antiviral, antitumor, antifungal and against
platelet aggregation, among others. Phospholipases A2 present in snake venoms are the most studied proteins in these models. Active and inactive A2 phospholipases have been shown to possess catalytic activity against tumor cells.
Objective. To isolate, purify and characterize the phospholipase A2 of the venom of Crotalus durissus
cumanensis to evaluate its in vitro antitumor activity.
Materials and methods. Isolation, purification and identification of crotoxin B was done with Size
Exclusion Chromatography, Reversed Phase High-Performance Liquid Chromatography, RP-HPLC, and
Mass Spectrometry. The cytotoxic effect on tumor cells (K562) and normal cells (peripheral blood
mononuclear cells) was determined using the MTT technique.
Results. The separation and subsequent identification of crotoxin B, found in the venom of C. d.
cumanensis from Colombia, showed that this phospholipase A2 has a cytotoxic effect on peripheral
blood mononuclear cells at a dose of 18.23 ± 0.57 μg / ml, whereas for K562 cells, it was 2.34 ±
0.199 μg/ml
Conclusions. The results suggest the use of crotoxin B, isolated from the venom of C. d. cumanensis,
as a possible therapeutic resource for human application.Introducción. Los venenos de serpientes representan una fuente importante de proteínas y péptidos, los cuales exhiben diversas actividades biológicas, tales como antibacterianas, antiparasitarias, antivirales, antitumorales, antifúngicas y contra la agregación plaquetaria, entre otras.
Las fosfolipasas A2 presentes en los venenos de serpientes son las proteínas más estudiadas en estos modelos. Se ha demostrado que las fosfolipasas A2, activas e inactivas, poseen actividad catalítica contra células tumorales.
Objetivo. Aislar, purificar y caracterizar la fosfolipasa A2 del veneno de Crotalus durissus cumanensis para evaluar su actividad antitumoral in vitro.
Materiales y métodos. El aislamiento, la purificación y la identificación de la crotoxina B se hizo mediante la cromatografía de exclusión molecular, la cromatografía líquida de alto rendimiento de fase inversa (Reversed Phase High-Performance Liquid Chromatography, RP-HPLC) y la espectrometría de masas. El efecto citotóxico sobre células tumorales (K562) y células normales (células mononucleares de sangre periférica) se determinó utilizando la técnica de MTT.
Resultados. La separación y posterior identificación de la crotoxina B del veneno de C. d. cumanensis de Colombia, permitieron evidenciar que esta fosfolipasa A2 posee efecto citotóxico sobre las células mononucleares de sangre periférica con una dosis de 18,23 ± 0,57 μg/ml, mientras que, para las células K562, fue de 2,34 ± 0,199 μg/ml.
Conclusiones. Los resultados sugieren la posibilidad de utilizar la crotoxina B aislada del veneno de C. d. cumanensis como un posible recurso terapéutico para su aplicación en humanos.
Palabras clave: Crotalus durissus cumanensis; citotoxicidad; fosfolipasas A2; crotoxina B. 
Processing acoustic images for the exploitation of fish farms
This work presents a processing methodology that uses data from a SONAR sensor located on a HROV to support the exploitation and management of fish farms.Peer Reviewe
Trunk Control Measurement Scale (TCMS): Psychometric Properties of Cross-Cultural Adaptation and Validation of the Spanish Version
The aim of this study was to develop a Spanish Version of the Trunk Measurement Scale (TCMS-S) to analyze its validity and reliability and determine the Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC) in children with Cerebral Palsy (CP). Participants were assessed twice 7–15 days apart with the TCMS-S and once with the Gross Motor Function Measurement-88 (GMFM-88), Pediatric Disability Inventory-Computer Adaptive Test (PEDI-CAT), Cerebral Palsy Quality of Life (CPQoL), and Gross Motor Classification System (GMFCS). Internal consistency was evaluated using Cronbach’s alpha, and the intraclass correlation (ICC) and kappa coefficients were used to investigate the agreement between the assessments. Finally, 96 participants with CP were included. The TCMS-S showed excellent internal consistency (Cronbach’s alpha = 0.95
[0.93 to 0.96]); was highly correlated with the GMFM-88 (rho = 0.816) and the “mobility” subscale of the PEDI-CAT (rho = 0.760); showed a moderate correlation with the “feeling about functioning” CPQoL subscale (rho = 0.576); and differentiated between the GMFCS levels. Excellent test–retest agreement was found for the total and subscale scores (ICC � 0.94 [0.89 to 0.97). For the total TCMS-S score, an SEM of 1.86 and an MDC of 5.15 were found. The TCMS-S is a valid and reliable tool for assessing trunk control in children with CP.Sección Deptal. de Radiología, Rehabilitación y Fisioterapia (Enfermería)Fac. de Enfermería, Fisioterapia y PodologíaTRUEUniversidad Europea de Madridpu
Steganography applied in the origin claim of pictures captured by drones based on chaos
In this work, steganography is implemented in photographs captured by an unmanned aerial vehicle (drone), with the purpose of adding an identifier that indicates which device they are taken from so it works for the recovery of the origin. In the system, a new technique that modifies the least significant bit (LSB) is applied, using a mathematical model to generate the chaotic orbits, one of the parts selects the RGB channel (Red, Green or Blue) where the LSB is changed and the other is implemented to calculate the random position of the sub pixel to be modified in the selected channel. In addition, a comparison between the bit to be hidden and the LSB of the pixel of the image is performed to verify if it is not necessary to modify it, which lessens the alterations in the container image. It is a tool to capture photos remotely with the Ar.Drone 2.0, with the features needed to perform an analysis that uses correlation diagrams and histograms to verify if the integrity of the message is guaranteed or if changes in the stego-image are visible to the naked eye. On the other hand, a test was done on the Baboon image to compare the robustness of the proposed system with other investigations, evaluating the correlation, contrast, energy, homogeneity, MSE, PSNR and quality index. The results generated were compared with the work of other authors concluding our system provides greater security, integrity, high sensitivity to the keys, it is not linked to a single chaotic system and can be applied to hide imperceptibly all kinds of information, in: radiographs, videos, files, official documents, and other types of containers.En este trabajo se implementó esteganografía en las fotografías capturadas por un vehículo aéreo no tripulado (dron), con la finalidad de agregar un identificador que indique desde que dispositivo fueron tomadas, y funcione para la reclamación de origen. En el sistema se aplicó una nueva técnica que modifica el bit menos significativo (LSB) usando un modelo matemático que se utiliza para generar dos órbitas caóticas, una de las cuales se usa para seleccionar el canal RGB (Rojo, Verde o Azul), donde se cambió el LSB y la otra se implementó para calcular de forma aleatoria la posición del subpixel que se modificará en el canal seleccionado; además se realizó una comparación entre el bit que se desea ocultar y el LSB del pixel de la imagen, para verificar si no es necesario modificarlo, lo cual altera menos la imagen original. Se realizaron pruebas del algoritmo en un Ar.drone 2.0, pero se puede aplicar para ocultar de forma imperceptible todo tipo de información, en: radiografías, videos, archivos, documentos oficiales, o cualquier otro tipo de contendor
Fish abundance estimation with imaging sonar in semi-intensive aquaculture ponds
To know the abundance of fishes and their size distribution in the semi-intensive rearing systems in traditional ponds is an aspect key to plan and manage efficiently the sales lots. Usually this information is obtained by means of sampling which mandatory supposes a direct catch and stressful and time consuming management of fishes. Therefore, in this work we propose the use of non-invasive procedures based on multibeam sonars or imaging sonars to count and size the fishes in the ponds. For that, we use a commercial technology portable-fixed multibeam imaging sonar and estimate the abundance in ponds of a gilt-head seabream (Sparus aurata) fishfarm
from sonar image analysis and adapting statistical methodologies traditionally applied for bird abundance estimation. Additionally, a simulation software was developed to emulate the fish aggregation contained in the rearing ponds. This computer program allows the calculation of an abundance correction factor which depends on the transducer beam size in relation to the pond size. The results indicate that the estimation is as accurate as the obtained by the fishfarm manager using traditional sampling methods and additionally it is possible to obtain a realistic function of the size distribution which allows estimate the biomass by size contained in the rearing ponds.This work was supported by KTTSeaDrones project (0622_KTTSEADRONES_5_E), cofunded by the European Regional Development Fund,
ERDF, through the Interreg V-A Spain-Portugal program (POCTEP)
2014–2020. We would like to express our gratitude to Rafael Rodríguez
Sierra (Manager of ‘Salinas del Astur’) for his willingness to carry out all
the experiments of the KTTSeaDrones project at the ‘Salinas del Astur’
facilities. Funding for open access charge: Universidad de Huelva/
CBUA
Steganography applied in the origin claim of pictures captured by drones based on chaos
In this work, steganography is implemented in photographs captured by an unmanned aerial vehicle (drone), with the purpose of adding an identifier that indicates which device they are taken from so it works for the recovery of the origin. In the system, a new technique that modifies the least significant bit (LSB) is applied, using a mathematical model to generate the chaotic orbits, one of the parts selects the RGB channel (Red, Green or Blue) where the LSB is changed and the other is implemented to calculate the random position of the sub pixel to be modified in the selected channel. In addition, a comparison between the bit to be hidden and the LSB of the pixel of the image is performed to verify if it is not necessary to modify it, which lessens the alterations in the container image. It is a tool to capture photos remotely with the Ar.Drone 2.0, with the features needed to perform an analysis that uses correlation diagrams and histograms to verify if the integrity of the message is guaranteed or if changes in the stego-image are visible to the naked eye. On the other hand, a test was done on the Baboon image to compare the robustness of the proposed system with other investigations, evaluating the correlation, contrast, energy, homogeneity, MSE, PSNR and quality index. The results generated were compared with the work of other authors concluding our system provides greater security, integrity, high sensitivity to the keys, it is not linked to a single chaotic system and can be applied to hide imperceptibly all kinds of information, in: radiographs, videos, files, official documents, and other types of containers.En este trabajo se implementó esteganografía en las fotografías capturadas por un vehículo aéreo no tripulado (dron), con la finalidad de agregar un identificador que indique desde que dispositivo fueron tomadas, y funcione para la reclamación de origen. En el sistema se aplicó una nueva técnica que modifica el bit menos significativo (LSB) usando un modelo matemático que se utiliza para generar dos órbitas caóticas, una de las cuales se usa para seleccionar el canal RGB (Rojo, Verde o Azul), donde se cambió el LSB y la otra se implementó para calcular de forma aleatoria la posición del subpixel que se modificará en el canal seleccionado; además se realizó una comparación entre el bit que se desea ocultar y el LSB del pixel de la imagen, para verificar si no es necesario modificarlo, lo cual altera menos la imagen original. Se realizaron pruebas del algoritmo en un Ar.drone 2.0, pero se puede aplicar para ocultar de forma imperceptible todo tipo de información, en: radiografías, videos, archivos, documentos oficiales, o cualquier otro tipo de contendor
Clinical Characteristics and Prognosis of COPD Patients Hospitalized with SARS-CoV-2
Objective
To describe the characteristics and prognosis of patients with COPD admitted to the hospital due to SARS-CoV-2 infection.
Methods
The SEMI-COVID registry is an ongoing retrospective cohort comprising consecutive COVID-19 patients hospitalized in Spain since the beginning of the pandemic in March 2020. Data on demographics, clinical characteristics, comorbidities, laboratory tests, radiology, treatment, and progress are collected. Patients with COPD were selected and compared to patients without COPD. Factors associated with a poor prognosis were analyzed.
Results
Of the 10,420 patients included in the SEMI-COVID registry as of May 21, 2020, 746 (7.16%) had a diagnosis of COPD. Patients with COPD are older than those without COPD (77 years vs 68 years) and more frequently male. They have more comorbidities (hypertension, hyperlipidemia, diabetes mellitus, atrial fibrillation, heart failure, ischemic heart disease, peripheral vascular disease, kidney failure) and a higher Charlson Comorbidity Index (2 vs 1, p<0.001). The mortality rate in COPD patients was 38.3% compared to 19.2% in patients without COPD (p<0.001). Male sex, a history of hypertension, heart failure, moderate–severe chronic kidney disease, presence of cerebrovascular disease with sequelae, degenerative neurological disease, dementia, functional dependence, and a higher Charlson Comorbidity Index have been associated with increased mortality due to COVID-19 in COPD patients. Survival was higher among patients with COPD who were treated with hydroxychloroquine (87.1% vs 74.9%, p<0.001) and with macrolides (57.9% vs 50%, p<0.037). Neither prone positioning nor non-invasive mechanical ventilation, high-flow nasal cannula, or invasive mechanical ventilation were associated with a better prognosis.
Conclusion
COPD patients admitted to the hospital with SARS-CoV-2 infection have more severe disease and a worse prognosis than non-COPD patients
Semillas en el tiempo : el latinoamericanismo filosófico contemporáneo
Los trabajos que conforman este Iibro giran en torno a
un eje: los filósofos latinoamericanistas contemporáneos,
desde 1950 en adelante. Todos ellos pensadores que han
reflexionado desde adentro, desde el continente acerca
de la identidad cultural y social de América Latina:
¿qué es América, qué es ser americano, cuál es
su historia, cuáles son sus contribuciones, qué
problemas se derivan de sus relaciones con el
Occidente, qué problemas del pasado inciden en su
presente, de qué modo debe asumir ese pasado, qué
conflictos se desprenden de su estructura de clases?
Éstas son algunas de las preguntas que vertebran el nuevo
movimiento, que se cuestiona fuertemente la identidad
latinoamericana.
La relevancia especial de "Semillas en el tiempo" reside
en que los autores de los estudios son destacados
especialistas en la materia, tanto por sus conocimientos
acerca de la Filosofía, como por su dedicación al estudio
de la problemática latinoamericana
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