1,340 research outputs found
A New Method for Sensorless Estimation of the Speed and Position in Brushed DC Motors Using Support Vector Machines
Currently, for many applications, it is necessary to know the speed and
position of motors. This can be achieved using mechanical sensors coupled to
the motor shaft or using sensorless techniques. The sensorless techniques in
brushed dc motors can be classified into two types: 1) techniques based on the
dynamic brushed dc motor model and 2) techniques based on the ripple component
of the current. This paper presents a new method, based on the ripple
component, for speed and position estimation in brushed dc motors, using
support vector machines. The proposed method only measures the current and
detects the pulses in this signal. The motor speed is estimated by using the
inverse distance between the detected pulses, and the position is estimated by
counting all detected pulses. The ability to detect ghost pulses and to discard
false pulses is the main advantage of this method over other sensorless
methods. The performed tests on two fractional horsepower brushed dc motors
indicate that the method works correctly in a wide range of speeds and
situations, in which the speed is constant or varies dynamically
Diabetes Patients' Care based on Mobile Monitoring
In this paper, we propose a new architecture for diabetes patients. These applications allow the monitoring, patient selfcontrol and communication between patient and doctor. Moreover, as an important study case, we present a mobile monitoring system which allows patients with diabetes to have a constant control of their glucose tendency as well as direct communication with their doctor. We present an application to solve this problem; we share some details of the current implementation, detailing the functionalities achieved so far.In this paper, we propose a new architecture for diabetes patients. These applications allow the monitoring, patient selfcontrol and communication between patient and doctor. Moreover, as an important study case, we present a mobile monitoring system which allows patients with diabetes to have a constant control of their glucose tendency as well as direct communication with their doctor. We present an application to solve this problem; we share some details of the current implementation, detailing the functionalities achieved so far
Diabetes Patients´ Care based on Mobile Monitoring
In this paper, we propose a new architecture for diabetes patients. These applications allow the monitoring, patient selfcontrol and communication between patient and doctor. Moreover, as an important study case, we present a mobile monitoring system which allows patients with diabetes to have a constant control of their glucose tendency as well as direct communication with their doctor. We present an application to solve this problem; we share some details of the current implementation, detailing the functionalities achieved so far.In this paper, we propose a new architecture for diabetes patients. These applications allow the monitoring, patient selfcontrol and communication between patient and doctor. Moreover, as an important study case, we present a mobile monitoring system which allows patients with diabetes to have a constant control of their glucose tendency as well as direct communication with their doctor. We present an application to solve this problem; we share some details of the current implementation, detailing the functionalities achieved so far
Influencia del comportamiento humano en la efectividad de intercambio del conocimiento en la empresa
El objetivo de este trabajo es identificar y analizar la
influencia que el comportamiento y las relaciones humanas ejercen en el intercambio del conocimiento en la empresa para dos tipos de trabajadores: los recién incorporados o ‘novatos’ y los experimentados o ‘veteranos’. Se abordan los efectos de tres variables concretas: la hostilidad del conocimiento, entendida como la negativa del trabajador a compartir su conocimiento; la prescindibilidad del trabajador o percepción de pérdida de relevancia por transmitir el conocimiento a otros; y el interés del conocimiento, que es la motivación por adquirir nuevos conocimientos. Para salvar la dificultad que supone
contrastar tales relaciones en la realidad de la empresa, se ha utilizado la metodología de simulación con multiagentes en Netlogo, configurando el estudio sobre tres tipos de simulación con tres opciones para cada una y generando 2000 simulaciones con 250 ciclos de movimientos en cada simulación.
Esta metodología ha permitido representar y obtener conclusiones valiosas, abriendo un amplio campo de posibilidades para la investigación de fenómenos relacionados con la Gestión del Conocimiento. El trabajo presenta dos novedades importantes: la identificación de las variables estudiadas y la metodología utilizada. De los resultados destácase que la hostilidad favorece el intercambio cuando aumentan los trabajadores veteranos y lo contrario para el caso de los novatos; el sentimiento de prescindibilidad dificulta compartir conocimientos entre veteranos y novatos; y el interés provoca siempre un aumento de los intercambios, independientemente del número y la categoría de los trabajadores
Estudio teórico-empírico de las barreras al intercambio del conocimiento en la empresa
El objetivo de este trabajo es investigar las barreras u obstáculos que dificultan el intercambio del conocimiento entre los trabajadores desde las perspectivas teórica y práctica. Se trata de una investigación novedosa en España por el tamaño de la muestra utilizada, pues sólo se han encontrado tres referencias de esta naturaleza para empresas chinas y americanas. A ese fin se han revisado los estudios teóricos de naturaleza psicológica y motivacional que explican el comportamiento y la actitud del trabajador, y los estudios sobre el clima, compromiso y estilo de
dirección que afectan a la compartición del conocimiento en la empresa. Esto justifica las bases teóricas en las que se sustenta el estudio, así como su propósito y los beneficios que aporta a la organización. Para la investigación empírica se ha elaborado una encuesta para una muestra de 557 trabajadores de 27 empresas de la provincia de Burgos, España. Los resultados obtenidos, referidos a las personas, revelan que las barreras más importantes al intercambio son la apropiación del conocimiento por los demás, la falta de incentivos explícitos, la ausencia de reciprocidad entre los compañeros y el contrato temporal o eventual. En cuanto a las negligencias o conductas de la dirección destacan la contratación por influencias o ‘enchufismo’, el acoso y humillación hacia el empleado, los climas laborales
inadecuados, una estructura organizativa mal diseñada o inexistente, o los estilos de dirección autoritarios y personalistas
Palynology from “The Jurassic Dinosaur Coast” of Asturias (Lastres Fm., Northwestern Spain): palynostratigraphical and palaeoecological insights
Abundant fossils of vertebrates (mainly footprints and bones of dinosaurs) and numerous invertebrates occur in the Upper Jurassic deposits of the Lastres Formation in the Asturias region, North of Spain. However, no palynological study has been published from this geological formation; therefore, much palaeoenvironmental and palaeoecological information is still unknown. In this study, a total of 62 morphospecies, belonging to 49 different morphogenera were identified, including pollen, spores, algae remains, fungi spores, dinoflagellates, foraminifera, and scolecodonts from four different locations on the Asturian coast. Spores are the dominant group of palynomorphs, both in diversity and abundance, contrasting with the minor diversity of pollen grains. The age of some key taxa indicates that the palynological assemblage cannot be older than the Kimmeridgian, suggesting a Kimmeridgian-Tithonian age. The botanical and environmental affinities of the pollen and spores indicate the presence of different plant assemblages, including plant communities from humid areas such as the margin of rivers and small freshwater ponds that were dominated by bryophytes and ferns, and a coastal plant community that would inhabit arid areas and would be dominated by gymnosperms and some pteridophytes. The SEM analyses of wood remains show the abundance of charcoalified remains suggesting that wildfires were usual in The Dinosaur Coast of Asturias during the Kimmeridgian.Xunta de Galicia | Ref. ED481A-2019/243Xunta de Galicia | Ref. ED481A-2020/175Chinese Academy of Sciences | Ref. XDB26000000Ministerio de Ciencia, Innovación y Universidades | Ref. PGC2018-094034-B-C2
Vascular NADH/NADPH oxidase is involved in enhanced superoxide production in spontaneously hypertensive rats
This study was designed to test the hypothesis that stimulation of nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase is involved in increased vascular superoxide anion (*O(2)(-)) production in spontaneously hypertensive rats (SHR). The study was performed in 16-week-old and 30-week-old normotensive Wistar-Kyoto rats (WKY(16) and WKY(30), respectively) and in 16-week-old and 30-week-old SHR (SHR(16) and SHR(30), respectively). In addition, 16-week-old SHR were treated with oral irbesartan (average dose 20 mg/kg per day) for 14 weeks (SHR(30)-I). Aortic NADH/NADPH oxidase activity was determined by use of chemiluminescence with lucigenin. The expression of p22phox messenger RNA was assessed by competitive reverse transcription-polymerase chain reaction. Vascular responses to acetylcholine were determined by isometric tension studies. Aortic wall structure was studied, determining the media thickness and the cross-sectional area by morphometric analysis. Whereas systolic blood pressure was significantly increased in the 2 groups of hypertensive animals compared with their normotensive controls, no differences were observed in systolic blood pressure between SHR(30) and SHR(16). No other differences in the parameters measured were found between WKY(16) and SHR(16). In SHR(30) compared with WKY(30), we found significantly greater p22phox mRNA level, NADH/NADPH-driven *O(2)(-) production, media thickness, and cross-sectional area and an impaired vasodilation in response to acetylcholine. Treated SHR had similar NADH/NADPH oxidase activity and p22phox expression as the WKY(30) group. The vascular functional and morphological parameters were improved in SHR(30)-I. These findings suggest that an association exists between p22phox gene overexpression and NADH/NADPH overactivity in the aortas of adult SHR. Enhanced NADH/NADPH oxidase-dependent *O(2)(-) production may contribute to endothelial dysfunction and vascular hypertrophy in this genetic model of hypertension
Epigenetic Modulation of Gremlin-1/NOTCH Pathway in Experimental Crescentic Immune-Mediated Glomerulonephritis
Crescentic glomerulonephritis is a devastating autoimmune disease that without early and properly treatment may rapidly progress to end-stage renal disease and death. Current immunosuppressive treatment provides limited efficacy and an important burden of adverse events. Epigenetic drugs are a source of novel therapeutic tools. Among them, bromodomain and extraterminal domain (BET) inhibitors (iBETs) block the interaction between bromodomains and acetylated proteins, including histones and transcription factors. iBETs have demonstrated protective effects on malignancy, inflammatory disorders and experimental kidney disease. Recently, Gremlin-1 was proposed as a urinary biomarker of disease progression in human anti-neutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. We have now evaluated whether iBETs could regulate Gremlin-1 in experimental anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS) in mice, a model resembling human crescentic glomerulonephritis. In NTS-injected mice, the iBET JQ1 inhibited renal Gremlin-1 overexpression and diminished glomerular damage, restoring podocyte numbers. Chromatin immunoprecipitation assay demonstrated BRD4 enrichment of the Grem-1 gene promoter in injured kidneys, consistent with Gremlin-1 epigenetic regulation. Moreover, JQ1 blocked BRD4 binding and inhibited Grem-1 gene transcription. The beneficial effect of iBETs was also mediated by modulation of NOTCH pathway. JQ1 inhibited the gene expression of the NOTCH effectors Hes-1 and Hey-1 in NTS-injured kidneys. Our results further support the role for epigenetic drugs, such as iBETs, in the treatment of rapidly progressive crescentic glomerulonephritis
Análisis de la correlación entre la autoevaluación, evaluación por pares y evaluaciones externas de la competencia clínica en los cursos clínicos del Grado de Medicina
Comparación entre la autoevaluación y evaluación por pares de competencias de conocimiento y profesionalismo en estudiantes de los cursos clínicos del Grado de Medicin
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