64 research outputs found

    Mathematical modelling of mass transfer phenomena for sucrose and lactitol molecules during osmotic dehydration of cherries

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    The diffusion phenomena of sucrose and lactitol in cherries using different proportions during osmotic dehydration was quantified by means of a mathematical model based on Fick's second law. The average effective diffusion coefficient for soluble solids in skin and flesh are 5.37 10−11 m2∕s and 1.24 10−10 m2∕s. Whereas, for water in skin and flesh are 9.27 10−09 m2∕s and 5.48 10−08 m2∕s. A significant difference for water diffusion coefficients (p < 0.05) was observed between the treatments. This could indicate that the diffusion between species and treatments is differential. Effective diffusion coefficients for water in skin and flesh are 2 orders of magnitude greater than effective diffusion coefficients for soluble solids. This is probably due to its lesser molecular weight. Furthermore, the effective diffusion coefficients for water and soluble solids in cherry skin are between 1 and 2 orders of magnitude lower than effective diffusion coefficients for both in cherry flesh, possibly due to the barrier effect exerted by the cherry skin.Fil: Maldonado, Mariela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Tecnológica Nacional; ArgentinaFil: González Pacheco, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Tecnológica Nacional; Argentin

    Cerejas em conserva feitas com lactitol: uma alternativa para reduzir o seu valor calórico

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    Polyalcohols are used&nbsp;in the food industry as nutritional sweeteners. They are well known for having&nbsp;a syrupy appearance when dissolved in&nbsp;water, and have prebiotic properties.Los polialcoholes son&nbsp;usados en la industria alimentaria como&nbsp;edulcorantes nutritivos y muy conocidos por tener aspecto de jarabe (sirope) al&nbsp;disolverlos en agua. Tienen además, propiedades prebióticas.Os poliálcoois são usados&nbsp;na indústria alimentar como adoçantes&nbsp;nutritivos e são bem conhecidos por terem uma aparência de um xarope quando&nbsp;dissolvidos em água. Apresentam ainda&nbsp;propriedades prebióticas

    Expression and differential cell distribution of low-threshold Ca2+ channels in mammalian male germ cells and sperm

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    AbstractNumerous sperm functions including the acrosome reaction (AR) are associated with Ca2+ influx through voltage-gated Ca2+ (CaV) channels. Although the electrophysiological characterization of Ca2+ currents in mature sperm has proven difficult, functional studies have revealed the presence of low-threshold (CaV3) channels in spermatogenic cells. However, the molecular identity of these proteins remains undefined. Here, we identified by reverse transcription polymerase chain reaction the expression of CaV3.3 mRNA in mouse male germ cells, an isoform not previously described in these cells. Immunoconfocal microscopy revealed the presence of the three CaV3 channel isoforms in mouse spermatogenic cells. In mature mouse sperm only CaV3.1 and CaV3.2 were detected in the head, suggesting its participation in the AR. CaV3.1 and CaV3.3 were found in the principal and the midpiece of the flagella. All CaV3 channels are also present in human sperm, but only to a minor extent in the head. These findings were corroborated by immunogold transmission electron microscopy. Tail localization of CaV3 channels suggested they may participate in motility, however, mibefradil and gossypol concentrations that inhibit CaV3 channels did not significantly affect human sperm motility. Only higher mibefradil doses that can block high-threshold (HVA) CaV channels caused small but significant motility alterations. Antibodies to HVA channels detected CaV1.3 and CaV2.3 in human sperm flagella

    Generation of Arc-Like and OIB-Like Magmas Triggered by Slab Detachment in the Eastern Mexican Alkaline Province: Petrological Evidence from the Cenozoic Sierra de San Carlos-Cruillas Complex, Tamaulipas

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    The origin of the Eastern Mexican Alkaline Province has been explained by landward arc migration and subsequent asthenospheric upwelling after slab roll-back of the Farallon Plate. In this work, we present new petrographic, mineral chemical, geochemical, and geochronological data of the Sierra de San Carlos-Cruillas (SSCC), one of the most important complexes in the province. This information, together with published data, helped us to reinterpret the tectonic processes operating during the generation of this province, as well as the mantle sources involved in the partial melting process. Detailed geochemical analysis suggests the participation of two types of metasomatized mantle regions: a lithospheric source modified by past subduction processes and an asthenospheric source slightly affected by carbonatite-related metasomatism. Variations in the partial melting degrees controlled the extent of magma enrichment in the latter. Major and trace element geochemistry, together with geochronological data and field relations, evinced an older post-orogenic setting related to the arc-like rocks (Eocene) and a younger intraplate extensional environment associated with all enriched igneous rocks (Oligocene-Miocene). Bivariate diagrams of SiO2-trace element ratios and multi-element patterns indicate that magmas from the SSCC complex dominantly evolved through fractional crystallization with a limited crustal contribution. Petrographic and mineral chemistry features suggest that some of these magmas experienced open-system processes (e.g. recharge events) in a complex and dynamic magmatic feeding system. In contrast to the traditional petrotectonic model, we propound that the passage and subsequent foundering of the Hess conjugate under northeastern Mexico resulted in its eclogitization and triggered slab tearing and succeeding detachment. This latter process occasioned mantle upwelling and the partial melting of the two recognized metasomatized mantle sources, thus generating the San Carlos-Cruillas magmatism

    Adiciones y correcciones a la orquidoflora valenciana, VI

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    Se aportan datos sobre algunos táxones poco abundantes en la Comunidad Valenciana; a destacar la presencia de Barlia robertiana en Monòver, Himantoglossum hircinum en Bocairent, Orchis fragrans en el Parc Natural de la Serra de Mariola y Orchis italica en Castellonet de la Conquesta.It is shown some data about rare taxa at the Valencian Community, specially about Barlia robertiana in Monòver, Himantoglossum hircinum in Bocairent, Orchis fragrans in the Natural Park Serra de Mariola and Orchis italica in Castellonet de la Conquesta

    Prácticas virtuales de fisiología

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    El presente proyecto de innovación educativa ha servido para generar material audiovisual compatible con dispositivos electrónicos para el aprendizaje de fisiología de una manera sencilla y accesible. Es la continuación de un proyecto del curso 2020-21, en el que se generó un material con las prácticas que se realizan con un programa de registros fisiológicos. En esta ocasión, se procedió a la grabación de los procedimientos experimentales de las asignaturas de Fisiología del Grado en Veterinaria y del Grado en CyTA y se han incluido en un formato presentación, en el que se exponen los conocimientos básicos de la práctica, los objetivos, el material y métodos, el procedimiento experimental en vídeo con explicaciones y finalmente la recogida de datos y la interpretación de los resultados. Así, se reduce el número de animales a utilizar en las prácticas porque no es necesario volver a hacer el procedimiento en el animal y el estudiante puede aprender a su ritmo y visualizar la presentación tantas veces como necesite para su aprendizaje, antes, durante y después de la práctica. Se ha contado con un amplio equipo en el que han participado PDI del departamento de Fisiología y de Producción Animal, PAS y estudiantes de grado y posgrado, de modo que la experiencia de todos ellos ha aportado un enfoque multidisciplinar, muy adecuado para la viabilidad del proyecto. El producto generado es un material duradero en el tiempo, que seguirá poniéndose a disposición de los estudiantes en cursos venideros

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO
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