2,679 research outputs found

    Mange in farmed rabbits

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    [EN] In this study we determined occurrence of mange in breeding rabbits on 1368 commercial farms in Portugal and Spain during 1996-2022. We obtained our information by carrying out 11 737 visits to 1334 doe farms, 11 farms only with growers, and 23 artificial insemination (AI) centres. The median size of the visited doe farms was 450 does (minimum to maximum: 100 2500 does) and 1175 does (ranging from100 to 6000 does) in 1996 and 2022, respectively. AI was used on 9% of the farms visited in 1996 and 95% in 2022. For our diagnoses we used (1) clinical observations on all visited farms to detect sarcoptic mange; (2) examination of the outer ear of breeding rabbits on a subset of farms to assess the prevalence of otodectic clinical mange (OCM); and (3) the examination of breeding rabbits and youngstock does (2.5 to 5.5 mo old) on a subset of 72 farms during 2018 to estimate prevalence of body mange compatible with cheyletiellosis. They were mainly clinical diagnoses, supported sometimes by a laboratorial confirmation. Over the course of the 27-yr clinical study, the cumulative incidence of sarcoptic mange was low; we recorded a total of 13 affected doe farms. The percentage of farms affected by OCM dropped from 55% in 1996 to 28% in 2022. OCM mean prevalence for the period 1996-2022 and 95% binomial confidence interval (CI) were 3.2% (95% CI [3.1-3.3%]), and 3.9% (95% CI [3.7-4.1%]) in does and bucks, respectively. We observed an improvement over time; the OCM yearly mean prevalence decreased from 7% in 1996 to 2.3% in 2022 in females and from 7.2% to 2.2% in males, respectively. This progress was compatible with the use of semen coming from AI centres; biosecurity measures and medical management also contributed. Genetic type was predisposing risk factor for OCM. Enabling risk factors were year and season (more affected in summer). Hair and skin disorders along the back, compatible with cheyletiellosis, were also assessed during 2018; we detected 50% of positive farms with various prevalence results in females, males or young does. In this study, we describe protocols observed in the control of benign and severe cases of mange in rabbitries, which included the use of ivermectin and synthetic acaricides. Ivermectin was used on 36% of doe farms visited during 2018-2022; we suggest that it should be used less often to lower its negative impact on the environment.Rosell, JM.; De La Fuente, LF.; Casais, R. (2024). Mange in farmed rabbits. World Rabbit Science. 32(1):57-71. https://doi.org/10.4995/wrs.2024.20624577132

    Técnicas y métodos más adecuados para la identificación del cemento aluminoso y de cemento de base portland en hormigones

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    Instrumental techniques are indicated and the most adequated methodologies for determining the nature of the binder in concretes are explained. These methods are: a) Determination of the Silicic Moduli through chemical analysis of the sample. This test reveáis very different valúes between cement portland based concrete and high alumina cement based concretes. b) X-ray diffraction. It is considered as the best method. In the present paper the main diffraction Unes corresponding to the components of hydrated portland cement and high alumina cement, are given. As complementary methods having as limited use, DTA and TG are studied. The most significative changes of the hydrated phases of both cements when heated are shown. A valoration of the Oxine test is also done as well as a description of using the characteristic colour of the high alumina cement as a practical indicator for determining its presence in concretes. Finally, comments on the significance of the presence of different CaCO3 polymorhisms in portland cement concrete and high alumina cement concrétete are also done.Se indican las técnicas y se explican las metodologías más adecuadas para determinar la naturaleza del conglomerante aluminoso en hormigones. Estos métodos son: a) Determinación del Módulo Silícico, a través de Análisis Químico de la muestra problema, al considerar la acusada diferencia de aquel valor en hormigones de cemento portland, respecto a hormigones de cemento aluminoso. b) Difracción de Rayos X. Se considera la técnica idónea. Se dan en el presente trabajo las principales líneas de difracción de los compuestos característicos de los cementos hidratados, portland y aluminoso. Como métodos complementarios y de utilidad limitada se estudia el ATD y el TG. Se proponen las temperaturas más significativas de los compuestos hidratados de aquellos cementos, a través de lo cual se puede deducir la presencia de uno u otro tipo de cemento. Se hace una valoración del método de la "oxina", significando el alcance limitado del mismo. Igualmente se describe el color como indicador de gran interés práctico en la determinación del cemento aluminoso. Así como un comentario documentado sobre el significado de la presencia de diferentes polimorfías del CaCO3 en los hormigones de cemento portland y de cemento aluminoso

    Extreme ultra-trail race induces muscular damage, risk for acute kidney injury and hyponatremia: A case report

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    A case study involving a healthy trained male athlete who completed a 786 km multistage ultra-trail race. Several markers were analyzed in blood and urine samples: creatinine (SCR) for kidney damage, sodium ([Na+]) for hyponatremia, creatine kinase (CK) for exertional rhabdo-myolysis, as well as other hematological values. Samples were taken before and after the race and during the recovery period (days 2 and 9 after the race). Results showed: SCR = 1.13 mg/dL, [Na+] =139 mmol/L and CK = 1.099 UI/L. Criteria for the determination of acute kidney damage were not met, and [Na+] concentration was above 135 mEq/L, indicating the absence of hyponatremia. Exer-tional rhabdomyolysis was suffered by the athlete (baseline CK increased fivefold), though this situation was reverted after 9 days of recovery. Ultra-trail races cause biochemical changes in athletes, which should be known about by healthcare professionals. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Chemical and structural changes of calcium ion exchange silica pigment in 0.5M NaCl and 0.5M Na 2SO4 solutions

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    This paper studies the suitability of an environmentallyfriendly anticorrosive pigment (Si/Ca) to replace Cr(VI) pigments, characterising the initial pigment and the products obtained after interaction with aqueous solutions containing aggressive ions from a corrosion viewpoint (Cl - and SO42- ). X-ray diffraction (XRD), calorimetry (DTATG), Fourier transform IR spectroscopy (FTIR) and scanningelectron microscopy (SEM-EDAX) techniques areused. The ion exchange capacity of the pigment is studied and the solutions obtained after the pigment-solution interaction are analysed. The results obtained show that a series of physical/chemical transformations take place in the pigment on interaction with the Cl - and SO42-  solutions, in some cases accompanied by the appearance of new crystalline phases, mainly calcium and sodium silicates and calcium sulphate. Analysis of the solutions obtained after interaction shows a rise in the calcium content as theionic force of the medium increases. These results suggest that the mechanism by which the pigment acts is not only based on ion exchange reactions but also on a structural modification of the pigment itself and consequently on (co)precipitation reactions that form insoluble compounds in the studied aggressive media

    Structural and optical characterisation of planar waveguides obtained via sol-gel

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    8 páginas, 6 figuras, 1 tabla.-- Trabajo presentado a la "International Conference on Applications of Optics and Photonics" celebrada en Braga (Portugal) en Mayo del 2011.Planar waveguides of SiO2:TiO2 (multilayer structure) and SiO2:CeO2 (thick layer) were prepared onto commercial glass substrates using a sol-gel technique combined with dip-coating. These glassy coatings were structural characterised by Transmission Electron Microscopy (TEM) Energy Dispersive X-ray analysis and by Confocal Microscopy. Thicknesses of 1230 nm and 4,15 μm and refractive indices of 1.59 and 1.48 for SiO2:TiO2 (70:30) and SiO2:CeO2 (95:5) waveguides were obtained, respectively, by Spectroscopic Ellypsometry. Losses of 0.8 dB/cm were measured by double prism method in the SiO2:CeO2 system.The authors acknowledge funding from MICINN (TEC2006-10469, CEN 2007-2014, SURFALUX SOL-00030930 and MAT2010-18519), from DGA (Group of Excellence in Laser Material Processing and Characterisation) and XUNTA DE GALICIA (INCITE08PXIB206013PR).Peer reviewe

    Detección de daño estructural de losas de hormigón armado de puentes sometidas a fatiga

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    The complex nature of structural phenomena still requires the comparison between numerical models and the real structural performance. Accordingly, many civil structures are monitored to detect structural damage and provide updated data for numerical models. Monitoring usually relies on the change of dynamic properties (experimental modal analysis). Regarding concrete structures, existing works have typically focused on the progressive decrease of natural frequencies under gradually increasing loads. In this paper, high-cycle fatigue effects are analyzed. An experimental campaign on specimens reproducing the top slab of concrete girders has been carried out, including fatigue tests and a reference static test. Impact-excitation tests were done at different stages to extract dynamic properties. Output-only models (only based on the structural response to an external excitation that is not measured) were used as identification techniques. The evolution of dynamic properties was correlated with damage development, with emphasis on the fatigue process stages: crack formation, cyclic reduction of tension-stiffening and brittle fracture of the reinforcement.La naturaleza compleja de muchos fenómenos estructurales requiere que los modelos numéricos necesiten ser verificados con el comportamiento estructural real. Por ello, muchas estructuras son monitorizadas, tanto para detectar posibles daños estructurales como para proporcionar datos a incluir en los modelos. A menudo, la monitorización se basa en el cambio de las propiedades dinámicas mediante técnicas de análisis modal experimental. Con respecto al hormigón estructural, la mayoría de los trabajos existentes se ha centrado en el cambio de las frecuencias propias con cargas monótonamente crecientes. En este artículo se analizan los efectos de la fatiga. Se ha llevado a cabo una campaña experimental sobre piezas que reproducen la losa superior de tableros de puentes, realizándose ensayos de fatiga y uno estático de referencia. Las propiedades dinámicas se han ido extrayendo mediante técnicas de output-only a partir de ensayos de excitación mediante impacto. El cambio de las propiedades dinámicas se ha correlacionado con las etapas del proceso de fatiga: formación de fisuras, reducción de tension-stiffening y rotura frágil de la armadura

    Procedimiento de preparación y materiales conformados basados en compuestos eutécticos binarios o ternarios de circonia

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    Referencia OEPM: P9600891.-- Fecha de solicitud: 19/04/1996.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).Procedimiento de preparación y materiales conformados basados en compuestos eutécticos binarios o ternarios de circonia. La presente invención está relacionada con la preparación de materiales con estructuras eutécticas micrométricas basados en mezclas de óxidos, conformados con dimensiones mili y submilimétricas mediante fusión zonal por láser con diferentes sistemas ópticos de focalización y control de los haces de los láseres. Su utilización es en el sector de la producción y conservación de energía, como elementos calefactores, refractarios, cátodos para plasmas de aire, electrodos, en componentes para celdas de combustión, microsensores de gas oxígeno, etc.Peer reviewe

    Incorporación de elementos traza en conchas de melanopsis durante el crecimiento : posibilidades de aplicación en paleoecología

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    El objetivo del presente trabajo está encaminado al estudio de las variaciones de oligoelementos en la concha de un gasterópodo de agua dulce del género Melanopsis (U dufouri (FERUSSAC), con dos morfotipos) y si éstas tienen que ver, o no, con la fluctuación de una serie de parámetros ambientales. La importancia del trabajo radica en la posibilidad de la aplicación paleoecológica de sus resultados, ya que el género MelanopsÍs tiene un abundante registro fósil durante todo el Cenozoico. La incorporación de oligoelementos se efectúa a medida que la concha va creciendo por acreción; lo ideal sería que tal crecimiento fuera circadiano, ya que se podría seguir día a día, sobre la concha, la fluctuación de sus componentes químicos. Sin embargo, nuestro trabajo muestra que, para esta especie, ello no es así. La tasa de acreción, tanto si se mide en función de los incrementos segregados por unidad de tiempo como del espesor segregado durante un período fijo, es función del tamaño de la concha para la misma población. Una primera campaña, de un mes de duración, ha revelado que en aquellas conchas, cuya tasa de acreción coincide con el número de días, las composiciones químicas de cada línea de crecimiento no parecen tener una relación de carácter fijo con las variaciones diarias de los parámetros del medio. Parece haber unos organismos más sensibles que otros a tal variación. Ello, pues, probablemente sea atribuible a variabilidad genética en cuanto a la capacidad de filtrado de los distintos iones. Durante un período de siete meses, en que la variación más significativa corresponde a la temperatura, uno de los morfotipos presenta variaciones de composición química correlacionadas con las variaciones de los parámetros del medio, mientras que el otro no muestra tendencias claras al respecto. La posibilidad de ritmos circadianos de acreción en caparazones de invertebrados está en contradicción con los resultados obtenidos en este estudio. Sería interesante analizar casos dados como válidos desde las perspectivas que aquí se abren. Las posibilidades de aplicación paleoecológica son también bajas, al menos para el género aquí estudiado.The living freshwater gastropod Melanopsis dufouri (FERUSSAC) has two morphotypes. The study of chemical variation of trace-elements in this gastropod and its correlation with the environmental fluctuation are the aim of this paper. Due to the genus MelanopsÍs has an abundant fossil record during the Cenozoic, the results of the present work could be of paleoecological interest. Trace-elements are embodied in the shell during growth. The shell of U dufouri has accretionary growth. There are several examples cited on circadian accretionary growth in invertebrate shells. However, in the present case and as a first coclusion, the accretion rate depends on the size of the shell. In a short-time field study (l month) that has been carried out we are found sorne shells with circadian accretion. Chemical compositions of growth lines are generelly not related to dialy fluctuations of environmental parameters. There are gastropods of this species more sensitive to these parameter:> than others. This fact could be due to genetic variability. .In. a long-time field study (7 montbs) also carried out, the most significant environmental vanation observed concerns to temperature in this periodo The chemical composition of one of the two morphotypes is very sensitive to variations of environmental parameters. The other morphotype does not seem to be enough sensitive to environmental variation. The poss!ble circadian accr~tion rates in M dufoun' does not agree with many general results about acc!etio~ary gro~ of mvertebrate sheUs. It should be interesting analizing the reported cases oC Clrcadlan rates m sheUs under the assumptions oC too paper. Paleoecological applications of ow results are very difficult Cor Cossil species oC [email protected] [email protected]
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