3,253 research outputs found
El examen serológico con muestras de sangre obtenidas en papel de filtro
Se ha puesto a punto una técnica de obtención de sangre total en papel filtro para el muestreo serológico de enfermedades de los conejos tales como: Enfermedad Hemorrágica Viral (RHVD); Encephalitozoonosis; Chlamydia psittaci y Mixomatosis. Se propone como alternativa de muestreo para la determinación de anticuerpos, por ser un método sencillo que no requiere muchos cuidados en el envío al laboratorio. Se evaluaron 94 muestras de suero de conejos llegados al laboratorio para el diagnóstico de las entidades antes citadas. Los resultados serológicos de la muestras de sangre total obtenida por venipuntura y en papel filtro, fueron comparados. Los métodos empleados incluyeron: Inmunofluorescencia Indirecta (IFI) para detectar IgG, Carbón inmunoensayo (CIA) e Inhibición de la Hemoaglutinación (IHA) para la evaluación de anticuerpos totales. Los resultados de sensibilidad, especificidad, índice de concordancia y valores predictivos positivos y negativos obtenidos en este trabajo fueron satisfactorios y nos permitieron decir que la toma y el transporte de muestras de sangre en papel de filtro es una técnica útil con sensibilidad y especificidad adecuada para realizar estudios seroepidemiológicos en conejos
Estilos de trabajo e inteligencias múltiples
El objetivo del trabajo es determinarla validez yflabilidad del modelo dejos
estilos de trabajo, fundamentado en la teoría de las Inteligencias Múltiples
(IM). Primero, se analizan los componentes de dicha teoría y su incidencia
en el curriculum escolar. En segundo lugar, se estudia el procedimiento de
evaluación. Además, se presentan los resultados del estudio empírico realizado
con una muestra de 237 alumnos pertenecientes a Educación Infantil y
Primaria, escolarizados en centros públicos y privados de la Región de Murcia.
Del estudio realizado se desprende que los estilos están asociados a las
diferentes inteligencias; además, el inventario de estilos de trabajo arroja
una validez y fiabilidad altamente consistente.________________________________
The objective of this work is to determinate the validity and reliability of the
model of work styles, as set out In the theory of Multiple Intelligences (MI).
First, we analyze the components of this theory and their Incidence in the
school curriculum. Second, we study the evaluation procedure. Additionally,
we present the results of an empirical study carried out with a sample of 237
students in public and private nursery and primary schools in the province
of Murcia, Spain. The study carried out reveals that the styles are associated
with the different Intelligences. Furthermore, the inventory of styles shows a
highly consistent validity and reliability
Vessel Recognition in Induction Heating Appliances - A Deep-Learning Approach
The selection of a vessel by an induction-hob user has a significant impact on the performance of the appliance. Due to the induction heating physical phenomena, there exist many factors that modify the equivalent impedance of induction hobs and, consequently, the operational conditions of the inverter. In particular, the type of vessel, which is a sole decision of the user, strongly affects these parameters. Besides, the ferromagnetic properties of the different materials the vessels are made with, vary differently with the excitation level, and given that most of the domestic induction hobs are based on an ac-bus voltage arrangement, the excitation level continuously varies. The algorithm proposed in this work takes advantage of this fact to identify the equivalent impedance of the load and recognize the pot. This is accomplished through a phase-sensitive detector that was already proposed in the literature and the application of deep learning. Different convolutional neural networks are tested on an augmented experimental-based dataset and the proposed algorithm is implemented in an experimental prototype with a system-on-chip. The proposed implementation is presented as an effective and accurate method to characterize and discriminate between different pots that could enable further functionalities in new generations of induction hobs
An amplifier-less acquisition chain for power measurements in series resonant inverters
Successive approximation register (SAR) analog-to-digital converter (ADC) manufacturers recommend the use of a driver amplifier to achieve the best performance. When a driver amplifier is not used, the conversion speed is severely penalized because of the need to meet the settling time constraint. This paper proposes a simple digital correction method to raise the performance (conversion speed and/or accuracy) when the acquisition chain lacks a driver amplifier. It is intended to reduce the cost, size and power consumption of the conditioning circuit while maintaining acceptable performance. The method is applied to the measurement of the output power delivered by a series resonant inverter for domestic induction heating
Soc-based in-cycle load identification of induction heating appliances
The equivalent load of an induction hob is strongly dependent on many parameters such as the switching frequency, the excitation level and the size, type, and material of the vessel. However, real-time methods with the ability to capture the variation of the load with the excitation level have not been proposed in the literature. This is an essential issue as most of the commercial induction hobs are based on an ac-bus voltage arrangement. This article proposes a method based on a phase-sensitive detector that offers an online tracking of the equivalent impedance for this type of arrangements. This algorithm enables advanced control functionalities such as clustering of vessels, material recognition, and premature detection of ferromagnetic saturation, among others. After simulation and experimental validation, the method is implemented into a prototype with a system-on-chip to verify its real-time behavior. The proposed approach is applied to different real-life situations that prove its great performance and applicability
Output voltage estimation of a half-bridge inverter for domestic induction heating applications
The power supplied to a vessel by a domestic induction-heating appliance is strongly dependent on several parameters the designer of the system has no control over: the type and the size of the vessel, misalignments between the pot and the inductor, temperatures, etc. A reliable estimation of the power is essential to ensure that the home appliance works under the expected conditions and the user experience is suitable. Furthermore, any reduction of hardware is totally welcome by consumer-electronics manufacturers. In this work, two methods to estimate the output voltage of a half-bridge inverter without digitizing it with an analog-to-digital converter are proposed and the effects that this estimation has on the power calculation are evaluated. Both methods are implemented and experimentally verified in a real prototype with an FPGA (Field-Programmable Gate Array)
Improving broiler performance at market age regardless of stocking density by using a pre-starter diet
Altres ajuts: Centro para el Desarrollo Tecnológico Industrial CDTI project IDI-20180885Broiler early nutrition has caught the attention of nutritionists due to the positive correlation between early growth rate and market weight. Early nutrition strategies such as low Ca levels or the use of highly digestible ingredients (e.g., spray-dried porcine plasma [SDPP]) have been reported to improve gut and muscle development, immunity, and overall growth of the bird. On the other hand, recent works suggested that stocking density represents the main constrain for modern chickens to express their full genetic potential. The current study aimed to elucidate the potential effects of pre-starter feeding strategies on contrasting livestock stocking densities. The study followed a factorial design of 2 contrasting starter programs (standard [0-11d] vs. pre-starter [0-4 d] + standard [4-11 d]) by 3 stocking densities (low, medium, and high, 27, 33, and 39 kg/BW/m, respectively). Birds placed at low stocking density showed higher BW and better FCR than those at high stocking density (P < 0.05) being this evident only after d 28. On the other hand, birds fed on pre-starter diet led to higher BW at 4 d (P < 0.001) and the effects on BW were maintained until market age (+2.54%; P < 0.05). The pre-starter diet also led to heavier carcasses (+2.2%; P < 0.05), improved uniformity (P < 0.10) and showed a lower incidence of lameness at high stocking densities (P < 0.05) compared to birds fed the standard starter diet. Results of the current study confirm that, regardless of the stocking density used, pre-starter diets (0-4 d) could lead to a better early growth and market weight
Host-pathogen evolutionary signatures reveal dynamics and future invasions of vampire bat rabies
Anticipating how epidemics will spread across landscapes requires understanding host dispersal events that are notoriously difficult to measure. Here, we contrast host and virus genetic signatures to resolve the spatiotemporal dynamics underlying geographic expansions of vampire bat rabies virus (VBRV) in Peru. Phylogenetic analysis revealed recent viral spread between populations that, according to extreme geographic structure in maternally inherited host mitochondrial DNA, appeared completely isolated. In contrast, greater population connectivity in biparentally inherited nuclear microsatellites explained the historical limits of invasions, suggesting that dispersing male bats spread VBRV between genetically isolated female populations. Host nuclear DNA further indicated unanticipated gene flow through the Andes mountains connecting the VBRV-free Pacific coast to the VBRV-endemic Amazon rainforest. By combining Bayesian phylogeography with landscape resistance models, we projected invasion routes through northern Peru that were validated by real-time livestock rabies mortality data. The first outbreaks of VBRV on the Pacific coast of South America could occur by June 2020, which would have serious implications for agriculture, wildlife conservation, and human health. Our results show that combining host and pathogen genetic data can identify sex biases in pathogen spatial spread, which may be a widespread but underappreciated phenomenon, and demonstrate that genetic forecasting can aid preparedness for impending viral invasions
Effect of mineral and vitamin C mix on growth performance and blood corticosterone concentrations in heat-stressed broilers
Heat stress is a major problem in the poultry industry, especially during summer months and when birds are raised under high-density conditions. Previous studies have reported that vitamin C or electrolyte supplementation could palliate the effects of heat stress in broiler chickens. The present study evaluated the effect of a mineral and vitamin mix (AHS) added to drinking water on the performance of broiler chickens. In total, 1,824 one-day-old birds were randomly allocated to 48 pens. Maximum animal density was 26.5 kg/m2. The control group received no additive; AHS-1 and -2 groups received the AHS mix at a concentration of 1 and 2 kg/1,000 L in drinking water, respectively; and the Vit-C group received vitamin C in drinking water at 200 g/1,000 L. All birds were fed the same diets based on a 3-phase feeding program; feed and water were given on ad libitum basis. To mimic heat stress conditions, temperature in the barn was raised to 35 C from 08:00 to 14:00 h each day. For the overall growing period (0 to 35 D), adding AHS to drinking water increased final BW, ADG, and ADFI linearly (PLinear Linear 0.10). No significant effect on mortality were found (8.77%; P > 0.10). Relative to control, all the treatments tested reduced (P < 0.05) corticosterone concentration in blood serum. In conclusion, the combined use of supplementary levels of minerals and vitamins could alleviate the effects of heat stress on broilers chickens.</p
Cuarta pantalla en los medios de comunicación: análisis de Periscope
El presente análisis se adentra en la aplicación de telefonía móvil Periscope, surgida en 2015. Una plataforma que permite trasmitir y ver video en streaming desde cualquier rincón del mundo. El periodismo no ha querido quedarse atrás y los profesionales de la información están utilizando la herramienta. Esta investigación tiene como principal objetivo analizar el uso mediático de la plataforma. Como consecuencia, el proyecto ahonda en el análisis de las emisiones, de forma cuantitativa y cualitativa, de varios medios de comunicación: los informativos de televisión Antena 3 Noticias, la emisora de radio COPE, el diario online El Español y el periódico El País. Como conclusión, advertimos que los resultados apuntan a que existen diferencias según el medio del que se trate.
This analysis focuses on the new mobile phone application Periscope, started in 2015. It is a platform that allows consuming broadcast TV and video streaming from anywhere in the world. News media Journalist did not want to behind and information professionals in Spain started using the tool. The main goal of this study is to analyze how professional news media use the platform. The project thus researches the programming of a number of broadcast media in a quantitative and qualitative way: the news of television channel Antena 3, radio channel COPE, online newspaper El Espanol and newspaper El Pais. In conclusion, the information shows that there are differences between the broadcast media researched
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