3,416 research outputs found

    Exploring Biocontrol of Unwanted Fungi by Autochthonous Debaryomyces hansenii Strains Isolated from Dry Meat Products

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    The exploration of alternatives to the use of chemical preservatives in food is a topic that has attracted great attention. The implementation of regulations associated with the reduction of these elements directly affects the production of cured meat products, with the premise of looking for more “natural” alternatives. From a previously identified collection of 24 strains of Debaryomyces hansenii, isolated from dry meat products of the “Valle de los Pedroches” (Córdoba), a screening was carried out to determine which strains had inhibitory potential against a battery of fungi belonging to the genera Aspergillus, Penicillium, and Candida. After a series of general trials, four strains showing the greatest potential were selected by a streak inhibition assay performed at several concentrations of NaCl. The inhibitory activity of the selected D. hansenii strains was later evaluated by measuring their fungal antagonistic diffusible and volatile compound production following radial inhibition and mouth-to-mouth approaches, respectively. Growth aspects, sporulation, and morphology changes were also considered during these assays. The results support ideas already raised in previous studies, such as the presence of D. hanseniii could imply a reduction of pathogenic fungi in food. Autochthonous yeast strains inhibited not only the mycelial growth, but also sporulation, which strengthens the biocontrol activity of this yeast. Our results show that, under certain conditions, all tested D. hansenii strains were able to alter the growth/development of fungi, being especially evident in the cases of Penicillium expansum and Aspergillus niger. Finally, our research can facilitate the future comparison of results in this area, since we contributed to standardize the methodology described to date, we quantified the number of yeast cells and spores used during the experiments, we homogenized growth conditions for both, yeasts, and molds, and applied an image analyzer software to quantify the growth of the studied microorganisms in solid media

    Candida albicans Potassium Transporters

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    Potassium is basic for life. All living organisms require high amounts of intracellular potassium, which fulfils multiple functions. To reach efficient potassium homeostasis, eukaryotic cells have developed a complex and tightly regulated system of transporters present both in the plasma membrane and in the membranes of internal organelles that allow correct intracellular potassium content and distribution. We review the information available on the pathogenic yeast Candida albicans. While some of the plasma membrane potassium transporters are relatively well known and experimental data about their nature, function or regulation have been published, in the case of most of the transporters present in intracellular membranes, their existence and even function have just been deduced because of their homology with those present in other yeasts, such as Saccharomyces cerevisiae. Finally, we analyse the possible links between pathogenicity and potassium homeostasis. We comment on the possibility of using some of these transporters as tentative targets in the search for new antifungal drugs

    Hemodynamics in the thoracic aorta using OpenFOAM: 4D PCMRI versus CFD

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    The aim of this work is the study of fluid dynamics models using the CFD software OpenFOAM, an open source software allowing meshing, manipulation, simulation and post-processing of many problems involving fluid mechanics. The work consists of a study with OpenFOAM of a real engineering problem, namely to analyze hemodynamics in the thoracic aorta in collaboration with CIMNE (Centre Internacional de Metodes Numerics a l'Enginyeria) and LABSON-UPC (Laboratorio de Sistemas Oleohidricos y Neumcos). Speci cally, the study aims to compute the shear stress that blood causes to aorta walls

    Thermal Vision for Soil Assessment in a Multipurpose Environmental Chamber under Martian Conditions towards Robot Navigation

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    Soil assessment is important for mobile robot planning and navigation on natural and planetary environments. Terramechanic characteristics can be inferred from the thermal behaviour of soils under the influence of sunlight using remote sensors such as Long-Wave Infrared cameras. However, this behaviour is greatly affected by the low atmospheric pressures of planets such as Mars, so practical models are needed to relate robot remote sensing data on Earth to target planetary exploration conditions. This article proposes a general framework based on multipurpose environmental chambers to generate representative diurnal cycle dataset pairs that can be useful to relate the thermal behaviour of a soil on Earth to the corresponding behaviour under planetary pressure conditions using remote sensing. Furthermore, we present an application of the proposed framework to generate datasets using the UMA-Laserlab chamber, which can replicate the atmospheric \ch{CO2} composition of Mars. In particular, we analyze the thermal behaviour of four soil samples of different granularity by comparing replicated Martian surface conditions and their Earth's diurnal cycle equivalent. Results indicate a correlation between granularity and thermal inertia that is consistent with available Mars surface measurements recorded by rovers. The resulting dataset pairs, consisting of representative diurnal cycle thermal images with heater, air, and subsurface temperatures, have been made available for the scientific community.Comment: 10 pages, 13 figure

    Detección y recogida de muestras por vehículos de exploración planetaria

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    Las futuras misiones de exploración planetaria exigen cada vez más autonomía, ya que estas misiones son cada vez más complejas. Un ejemplo claro es la misión de retorno de muestras a Marte, en la que el Sample Fetch Rover debe recoger tubos de muestras en un lugar remoto y llevarlos de vuelta a la estación base para lanzarlos a la Tierra. Esta misión requiere ampliar las capacidades autónomas a bordo. En primer lugar, el componente de navegación debe ser capaz de detectar y localizar los tubos de muestra, y en segundo lugar, los de guiado y control deben situar el rover cerca de los tubos de muestra y mover el manipulador para recogerlos. Estas son las principales aportaciones de este trabajo. La primera cuestión se ha resuelto mediante el uso de Redes Neuronales Profundas, que permiten identificar los tubos de muestra previamente entrenados en imágenes, y la segunda se ha resuelto ampliando el algoritmo de planificación de trayectorias dentro del componente de Guiado. Para demostrar y validar los métodos propuestos, se han realizado dos experimentos. Una primera prueba de campo en el terreno experimental de Búsqueda y Rescate de la Universidad de Málaga, y una segunda prueba de laboratorio en el Laboratorio de Robótica Planetaria de la Agencia Espacial Europea. Ambos experimentos se llevaron a cabo utilizando el Rover de Pruebas ExoMars, propiedad de esta última institución.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    MicroRNA-200 Family Modulation in Distinct Breast Cancer Phenotypes

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    The epithelial to mesenchymal transition (EMT) contributes to tumor invasion and metastasis in a variety of cancer types. In human breast cancer, gene expression studies have determined that basal-B/claudin-low and metaplastic cancers exhibit EMT-related characteristics, but the molecular mechanisms underlying this observation are unknown. As the family of miR-200 microRNAs has been shown to regulate EMT in normal tissues and cancer, here we evaluated whether the expression of the miR-200 family (miR-200f) and their epigenetic state correlate with EMT features in human breast carcinomas. We analyzed by qRT-PCR the expression of miR-200f members and various EMT-transcriptional inducers in a series of 70 breast cancers comprising an array of phenotypic subtypes: estrogen receptor positive (ER+), HER2 positive (HER2+), and triple negative (TN), including a subset of metaplastic breast carcinomas (MBCs) with sarcomatous (homologous or heterologous) differentiation. No MBCs with squamous differentiation were included. The DNA methylation status of miR-200f loci in tumor samples were inspected using Sequenom MassArray® MALDI-TOF platform. We also used two non-tumorigenic breast basal cell lines that spontaneously undergo EMT to study the modulation of miR-200f expression during EMT in vitro. We demonstrate that miR-200f is strongly decreased in MBCs compared with other cancer types. TN and HER2+ breast cancers also exhibited lower miR-200f expression than ER+ tumors. Significantly, the decreased miR-200f expression found in MBCs is accompanied by an increase in the expression levels of EMT-transcriptional inducers, and hypermethylation of the miR-200c-141 locus. Similar to tumor samples, we demonstrated that downregulation of miR-200f and hypermethylation of the miR-200c-141 locus, together with upregulation of EMT-transcriptional inducers also occur in an in vitro cellular model of spontaneous EMT. Thus, the expression and methylation status of miR-200f could be used as hypothetical biomarkers to assess the occurrence of EMT in breast cancer. © 2012 Castilla et al.This work was supported by grants from: the Instituto de Salud Carlos III (ISCIII; Grant Nos PI07/90324 and PI080971) and the Ministerio de Ciencia e Innovación (MCINN), co-financed by the European Development Regional Fund, “A way to achieve Europe” EDRF (Grant No. RD06/0020/0013); the Junta de Andalucía (Consejería de Salud, Grant No.PI-0384/2007, PI0581/2009); the Consejería de Innovación (Proyecto de Excelencia, Grant No. P07-CVI-03100); and Sandra Ibarra Foundation (Grant No. 2011/088) to JP. MAC and JDM are PhD researchers funded by the ISCIII (Grant No. RD06/0020/0013) and the Consejería de Salud, Junta de Andalucía (PI0581/2009), respectively. DS was funded by an EU Marie Curie Intra-European Fellowship (PIEF-GA-2008-221083) and by Breakthrough Breast Cancer. LRP is a PhD student recipient of a PFIS fellowship (Grant No. F109/00193). MB is a researcher funded by the ISCIII-Red de Biobancos RD09/0076/00085. SR works as a lab technician supported by the ISCIII (PI080971). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

    Characterization of mesenchymal stem cells in sheep naturally infected with scrapie

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    Mesenchymal stem cells (MSCs) can be infected with prions and have been proposed as in vitro cell-based models for prion replication. In addition, autologous MSCs are of interest for cell therapy in neurodegenerative diseases. To the best of our knowledge, the effect of prion diseases on the characteristics of these cells has never been investigated. Here, we analysed the properties of MSCs obtained from bone marrow (BM-MSCs) and peripheral blood (PB-MSCs) of sheep naturally infected with scrapie — a large mammal model for the study of prion diseases. After three passages of expansion, MSCs derived from scrapie animals displayed similar adipogenic, chondrogenic and osteogenic differentiation ability as cells from healthy controls, although a subtle decrease in the proliferation potential was observed. Exceptionally, mesenchymal markers such as CD29 were significantly upregulated at the transcript level compared with controls. Scrapie MSCs were able to transdifferentiate into neuron-like cells, but displayed lower levels of neurogenic markers at basal conditions, which could limit this potential. The expression levels of cellular prion protein (PrPC) were highly variable between cultures, and no significant differences were observed between control and scrapie-derived MSCs. However, during neurogenic differentiation the expression of PrPC was upregulated in MSCs. This characteristic could be useful for developing in vitro models for prion replication. Despite the infectivity reported for MSCs obtained from scrapie-infected mice and Creutzfeldt–Jakob disease patients, protein misfolding cyclic amplification did not detect PrPSc in BM- or PB-MSCs from scrapie-infected sheep, which limits their use for in vivo diagnosis for scrapie

    Fiabilidad de la velocidad de ejecución en tres modalidades del ejercicio de press de banca: influencia del nivel de experiencia

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    Premio Congreso SIBB 2019El objetivo del estudio fue comparar la fiabilidad de la velocidad media propulsiva (VMP) entre tres variantes del ejercicio de press de banca (PB). Quince hombres con experiencia y 15 sin experiencia con el ejercicio de PB realizaron en orden aleatorizado tres variantes del ejercicio de PB en diferentes sesiones (sólo-concéntrico, excéntrico-rápido y excéntrico-controlado). La VMP se registró ante tres cargas (≈ 30%1RM, 50%1RM y 75%1RM) con un transductor lineal de velocidad. La fiabilidad fue siempre alta (coeficiente de variación [CV] ≤ 5,76%, coeficiente de correlación intraclase [CCI] ≥ 0,74). La comparación de los CV reveló una mayor fiabilidad para las variantes sólo-concéntrico y excéntrico-rápido en comparación con la variante excéntrico-controlado (CV ratio > 1,15), no existiendo diferencias significativas en fiabilidad entre las variantes sólo-concéntrico y excéntrico-rápido (CV ratio < 1,15). No se observaron diferencias en fiabilidad entre los participantes con (CV ≤ 5,76%; CCI ≥ 0,83) y sin experiencia (CV ≤ 5,21%; CCI ≥ 0,74). Estos resultados apoyan el uso de las modalidades de PB sólo-concéntrico y excéntrico-rápido para evaluar la fuerza de los miembros superiores a través de la medición de la velocidad de ejecución en participantes con y sin  experiencia con el ejercicio de PB.Award-winningPremio Congreso SIBB 2019Peer Reviewe
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