317 research outputs found

    Un modelo Casi Ideal de Demanda de Combustibles para la Industria de Transporte

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    Este paper utilizando el Modelo Casi Ideal de Demanda (AIDS) por medio de ecuaciones aparentemente no relacionadas para la industria de combustibles en el sector transporte en Colombia, analiza las elasticidades precio de la demanda, precio cruzada de la demanda y gasto de la demanda de la Gasolina motor, Diesel y Gas Natural Vehicular (GNV), dada la recomposición que ha presentado esta industria entre el 2003 y 2012, con el objetivo de determinar si estos combustibles se comportan como sustitutos o complementarios y se trata de bienes necesarios o no. Los principales resultados indican que la elasticidad precio de la demanda de la Gasolina y el Diesel son bienes inelásticos, mientras que el GNV se comporta como un bien elástico. Por su parte, por medio de la elasticidad precio cruzada de la demanda, se encuentra que solo el Diesel y el GNV se comportan como bienes sustitutos, mientras que para el resto de relaciones (Gasolina-Diesel y Gasolina- GNV) se observa un comportamiento de complementariedad. Además desde la elasticidad gasto de la demanda se encontró que la Gasolina y el Diesel se comportan como bienes normales, mientras que el GNV resulta ser un bien inferior.This article presents an Almost Ideal Demand System (AIDS) for different types of fuels in Colombia, focusing specifically on the transport industry. Estimates of price, expenditure and cross elasticities are computed using a Seemingly Unrelated Regressions (SUR) model and based on 10 years observations (2003-2012). Results show that diesel and regular gas behave as inelastic goods while natural gas is more elastic. Also, diesel fuels and natural gas seem to behave as substitutes while there’s a complementary relation among the others (regular gas-Diesel; regular fuels-Natural Gas). Regarding the expenditures elasticities, this paper concludes that regular gas and diesel behave as normal goods while natural gas seems be an inferior type of fuel for the transport sector

    Predicting the energy consumption of heated plastic greenhouses in south-eastern Spain

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    [ENG] Measurements of heat consumption in a parral type greenhouse, equipped with an air-heating system, were carried out in south-eastern Spain (Almería) during the 1998/99 winter. From the daily values of heat consumption (Qd, MJ m-2 d-1) recorded in five identical greenhouses heated to different night temperature set-points (Tc), and data of minimum outside air temperature (Te,min), relationships between Qd and the temperature difference (ΔTmin = Tc – Te,min) were established. Linear regressions between Qd and ΔTmin gave satisfactory fits (R2 ranging from 0.75 to 0.83), considering that Te,min was the only input data for the model. When all data were pooled, the correlation was curvilinear, the best fit to a 2nd order polynomial being Qd = 0.049 ΔTmin 2 – 0.001 ΔTmin + 1.107 (R2 = 0.89). Validation of this model was performed using data obtained during other years, giving a fair agreement at the daily (R2 = 0.86), 10-day (R2 = 0.95) and yearly (R2 = 0.99) time scales. This simple model could be of interest to growers for decision-making related to the choice of set-point temperature and crop planning in heated greenhouses.[ESP] Se realizaron medidas de consumo de energía de la calefacción por aire caliente en invernaderos tipo parral durante la campaña 1998/99 en el sureste de España (Almería). Se determinaron relaciones adecuadas, para cinco invernaderos calentados a diferentes temperaturas nocturnas de consigna (Tc), entre los valores de consumos diarios de energía (Qd, MJ m-2 d-1) y la diferencia (ΔTmin) entre la temperatura de consigna de calefacción y la temperatura mínima exterior (Te,min). La regresión lineal entre Qd y ΔTmin fue satisfactoria (R2 varió entre 0,75 y 0,83), considerando que Te,min fue la única variable de entrada para el modelo. Cuando se analizaron todos los datos en conjunto, la correlación fue curvilínea, siendo el mejor ajuste para un polinomio de 2º orden, Qd = 0,049 ΔTmin 2 – 0,001 ΔTmin + 1,107 (R2 = 0,89). La validación de este modelo fue realizada utilizando datos de otros años, mostrando un ajuste adecuado para los periodos diarios (R2 = 0,86), 10-días (R2 = 0,95) y anuales (R2 = 0,99). Este sencillo modelo puede ser de interés para los agricultores a la hora de tomar decisiones sobre el mercado, escoger la temperatura de consigna y programar el periodo de calefacción del invernadero

    Regresión de un caso de linfosarcoma canino tras un tratamiento inmunoquimioterápico

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    Presentamos un caso clínico de un linfosarcoma multicéntrico en un perro y su evolución con un tratamiento inmunoquimioterápico, apreciándose una regresión del proceso tumoral al final del mismo.We have reported a case report about a multicentríc lymphosarcoma in a dog and its evolution with an immunochemotherapeutic protocol. We noticed a total regresion of the tumor at the end of the treatment

    Effect of small-sided games on football players

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    El objetivo ha sido analizar cómo influyen los juegos reducidos o SSGs sobre la condición física, técnica y los cambios de dirección (CODA) en jugadoras alevines de fútbol femenino. Participan 12 jugadoras de fútbol femenino. Realizaron 14 sesiones de entrenamiento basado en juegos reducidos de fútbol. La muestra presenta valores normales en la prueba de Saphiro-Wilk, además, en la prueba de t de Student muestra que existen diferencias estadísticamente muy significativas (p ≤0,00) en todas las variables físicas analizadas, menos en el caso de la fuerza explosiva. En las variables de técnica nos muestra que existen diferencias significativas en todas las variables analizadas (p ≤0,00). Por último existen correlaciones positivas y estadísticamente significativas entre las distintas variables analizadas. De esta forma podemos considerar los juegos reducidos son un método adecuado y muy ventajoso para el entrenamiento en las etapas iniciales o de formación en jugadoras de fútbolThe objective has been to analyze how small-sided games or SSGs affect physical, technical and changes of direction (CODA) in U12 female soccer players. 12 female soccer players participate. They conducted 14 training sessions based on reduced soccer games. The sample has normal values in the Saphiro-Wilk test, and in the Student's t test it shows that there are statistically very significant differences (p ≤0,00) in all the analyzed physical variables, less in the case of the explosive force. In the technique variables we show that there are significant differences in all variables analyzed (p ≤0,00). Finally, there are positive and statistically significant correlations between the different variables analyzed. In this way we can consider reduced games are a suitable and very advantageous method for training in the initial stages or training in soccer player

    Caracterización lesional y etiológica de neumonías en vacuno de cebo sacrificado en matadero

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    Trabajo presentado a la: XXVII Reunión de la Sociedad Española de Anatomía Patológica Veterinaria. (Barcelona, España, 17-19 junio de 2015).Peer Reviewe

    Color image segmentation using perceptual spaces through applets for determining and preventing diseases in chili peppers

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    Plant pathogens cause disease in plants. Chili peppers are one of the most important crops in the world. There are currently disease detection techniques classified as: biochemical, microscopy, immunology, nucleic acid hybridization, identification by visual inspection in vitro or in situ but these have the following disadvantages: they require several days, their implementation is costly and highly trained. This paper proposes a method for knowing and preventing the disease in chili peppers plant through a color image processing, using online system developed in Java applets. This system gets results in real time and remotely (Internet). The images are converted to perceptual spaces [hue, saturation and lightness (HSL), hue, saturation, and intensity (HSI) and hue saturation and value (HSV)]. Sequence was applied to the proposed method. HSI color space was the best detected disease. The percentage of disease in the leaf is of 12.42%. HSL and HSV do not expose the exact area of the disease compared to the HSI color space. Finally, images were analyzed and the disease is known by the expert in plant pathology to take preventive or corrective actions.Keywords: Applets, knowing disease, color image segmentation, perceptual spacesAfrican Journal of Biotechnology Vol. 12(7), pp. 679-68

    Ambient Intelligence Systems for Personalized Sport Training

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    Several research programs are tackling the use of Wireless Sensor Networks (WSN) at specific fields, such as e-Health, e-Inclusion or e-Sport. This is the case of the project “Ambient Intelligence Systems Support for Athletes with Specific Profiles”, which intends to assist athletes in their training. In this paper, the main developments and outcomes from this project are described. The architecture of the system comprises a WSN deployed in the training area which provides communication with athletes’ mobile equipments, performs location tasks, and harvests environmental data (wind speed, temperature, etc.). Athletes are equipped with a monitoring unit which obtains data from their training (pulse, speed, etc.). Besides, a decision engine combines these real-time data together with static information about the training field, and from the athlete, to direct athletes’ training to fulfill some specific goal. A prototype is presented in this work for a cross country running scenario, where the objective is to maintain the heart rate (HR) of the runner in a target range. For each track, the environmental conditions (temperature of the next track), the current athlete condition (HR), and the intrinsic difficulty of the track (slopes) influence the performance of the athlete. The decision engine, implemented by means of (m; s)-splines interpolation, estimates the future HR and selects the best track in each fork of the circuit. This method achieves a success ratio in the order of 80%. Indeed, results demonstrate that if environmental information is not take into account to derive training orders, the success ratio is reduced notably.Ministerio de Educación y Ciencia; DEP2006-56158-C03-01/02/03Ministerio de Educación y Ciencia; TEC2007-67966 -01/02/TCM CON-PARTE-1/2Ministerio de Industria, Turismo y Comercio ; TSI-020301-2008-16 ELISAMinisterio de Industria, Turismo y Comercio ; TSI-020301-2008-2 PIRAmID

    Placental thrombosis in acute phase abortions during experimental Toxoplasma gondii infection in sheep

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    43 p.After oral administration of ewes during mid gestation with 2000 freshly prepared sporulated oocysts of T. gondii isolate M4, abortions occurred between days 7 and 11 in 91.6% of pregnant and infected ewes. Afterwards, a further infection was carried out at late gestation in another group of sheep with 500 sporulated oocysts. Abortions happened again between days 9 and 11 post infection (pi) in 58.3% of the infected ewes. Classically, abortions in natural and experimental ovine toxoplasmosis usually occur one month after infection. Few experimental studies have reported the so-called acute phase abortions as early as 7 to 14 days after oral inoculation of oocysts, and pyrexia was proposed to be responsible for abortion, although the underline mechanism was not elucidated. In the present study, all placentas analysed from ewes suffering acute phase abortions showed infarcts and thrombosis in the caruncullar villi of the placentomes and ischemic lesions (periventricular leukomalacia) in the brain of some foetuses. The parasite was identified by PCR in samples from some placentomes of only one sheep, and no antigen was detected by immunohistochemical labelling. These findings suggest that the vascular lesions found in the placenta, and the consequent hypoxic damage to the foetus, could be associated to the occurrence of acute phase abortions. Although the pathogenesis of these lesions remains to be determined, the infectious dose or virulence of the isolate may play a role in their developmentS
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