3,024 research outputs found

    An End to a Means: How DNA-End Structure Shapes the Double-Strand Break Repair Process

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    Endogenously-arising DNA double-strand breaks (DSBs) rarely harbor canonical 5'-phosphate, 3'-hydroxyl moieties at the ends, which are, regardless of the pathway used, ultimately required for their repair. Cells are therefore endowed with a wide variety of enzymes that can deal with these chemical and structural variations and guarantee the formation of ligatable termini. An important distinction is whether the ends are directly "unblocked" by specific enzymatic activities without affecting the integrity of the DNA molecule and its sequence, or whether they are "processed" by unspecific nucleases that remove nucleotides from the termini. DNA end structure and configuration, therefore, shape the repair process, its requirements, and, importantly, its final outcome. Thus, the molecular mechanisms that coordinate and integrate the cellular response to blocked DSBs, although still largely unexplored, can be particularly relevant for maintaining genome integrity and avoiding malignant transformation and cancer.España, Junta de Andalucía SAF2017-89619-R, CVI-7948European Research Council (ERC-CoG-2014-647359

    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

    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

    RanBP2-Mediated SUMOylation Promotes Human DNA Polymerase Lambda Nuclear Localization and DNA Repair

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    Cellular DNA is under constant attack by a wide variety of agents, both endogenous and exogenous. To counteract DNA damage, human cells have a large collection of DNA repair factors. Among them, DNA polymerase lambda (Polλ) stands out for its versatility, as it participates in different DNA repair and damage tolerance pathways in which gap-filling DNA synthesis is required. In this work we show that human Polλ is conjugated with Small Ubiquitin-like MOdifier (SUMO) proteins both in vitro and in vivo, with Lys27 being the main target of this covalent modification. Polλ SUMOylation takes place in the nuclear pore complex and is mediated by the E3 ligase RanBP2. This post-translational modification promotes Polλ entry into the nucleus, which is required for its recruitment to DNA lesions and stimulated by DNA damage induction. Our work represents an advance in the knowledge of molecular pathways that regulate cellular localization of human Polλ, which are essential to be able to perform its functions during repair of nuclear DNA, and that might constitute an important point for the modulation of its activity in human cells

    Diseño conceptual de una estación experimental de tratamiento de aguas residuales domésticas orientada a Municipios con población menor a 30.000 habitantes.

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    Se presenta el diseño conceptual de una planta experimental de tratamiento de aguas residuales para poblaciones menores de 30.000 habitantes. El diseño integra seis esquemas de tratamiento interconectados, incluyendo sistemas convencionales y no convencionales, con disposición final del efluente a un cuerpo de agua o infiltración lenta en el terreno, cumpliendo con la norma vigente en Colombia. El proceso incluyó una revisión del estado del arte, el diseño de plantas de este tipo como la planta de Carrión de los Céspedes (Andalucía-España), la planta UFMG/COPASA (Minas Gerais-Brasil), los trabajos realizados en Colombia del IDEAM-CINARAUTP y los ensayos realizados por Madera, Silva y Peña del CINARA en planta piloto. El área estimada para la construcción de los esquemas propuestos es de 18.000 m2 y los costos fijos de construcción de la planta se estiman en 850 millones de pesospara tratar un caudal de 1,5 l/s de agua residual doméstica

    Método rápido de obtención de aceite de oliva virgen para determinación de acidez

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    A rapid and simple method to obtain, from olive samples, enough quantity of oil to determine acidity grade is proposed. From paste samples of milled olives, different fraction are separated to be centrifugated during 5 minutes at 4500 r.p.m. Oil acidity results obtained from sodium sulfate anhidrous and natural microtalc added samples are compared with blank samples, and with those obtained by the Abencor extraction procedure. The correlation between the acidity of oil samples obtained by the Abencor method is also analyzed against other samples obtained by the normalized method in Spain, norm UNE 55070, Soxhlet system. Results show that in all the centrifugated samples enough amount of oil is obtained to determin the acidity grade, it also show that treatment with sodium sulfate anhidrous obtains a bigger recovery percentage, and that in all 3 cases, the acidity shows a good correlation with that of the Abencor system, doubling the number of samples analysed by the Abencor system. It also shows that the acidity grade obtained by using the UNE 55070 norm is aproximately 0,3 grades above that obtained by the Abencor system.<br><br>Se propone un método rápido y sencillo para obtener, a partir de muestras de aceitunas, suficiente cantidad de aceite para determinar su grado de acidez. A partir de muestras de pasta de aceitunas molidas se separan distintas fracciones que se someten a un proceso de centrifugación a 4500 r.p.m. durante 5 minutos. Se comparan los resultados de acidez de los aceites obtenidos de las muestras con adición de microtalco natural y sulfato sódico anhidro, con muestras testigo, así como con el procedimiento de extracción Abencor. Se analiza también la correlación entre la acidez de muestras de aceite obtenidas por el método Abencor, con otras obtenidas por el método normalizado en España, norma UNE 55070, basado en la extracción del aceite por el método Soxhlet. Los resultados ponen de manifiesto que en las muestras centrifugadas se obtiene cantidad suficiente de aceite para la determinación del grado de acidez, que el tratamiento con sulfato sódico anhidro consigue mayor porcentaje de recuperación, y que, en los tres casos, la acidez presenta buena correlación con la del sistema Abencor, duplicando el número de muestras analizadas respecto a este método. Así mismo, se demuestra que el valor de acidez obtenido al aplicar la norma UNE 55070 es aproximadamente 0,3 grados por encima del obtenido por el sistema Abencor

    The showrunner’s skills and responsibilities in the creation and production process of fiction series in the contemporary North American television industry

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    This article has been written during the pre-doctoral contract: "Formacion de Profesorado Universitario" (FPU 15/00737) of the Government of Spain. Project National Plan "Transmedializacion y crowdsourcing en las narrativas de ficcion y no ficcion audiovisuales, periodisticas, dramaticas y literarias" (2018-2020) (Ref. CSO2017-85965-P), Domingo Sanchez-Mesa Martinez and Jordi AlberichPascual. International Research Stay at California State University L.A. (2018) funded by University of Granada, and supervised by Tanya Kane-Parry. We thank television professionals for attending the interviews and offering valuable data for this research.Contemporary fiction TV series production in North America is characterized by the showrunner figure’s importance. This paper aims to study the concept of “showrunner” as executive-creative producer, analyze the competencies and responsibilities carried out by them during the production process of TV shows according to personal and professional factors, and examine their position within the current television market. For this purpose, a literature review on fiction TV series production and television authorship has been conducted. After this, adopting the focus of media production studies, a qualitative methodology based on in-depth personal interviews has been used, which was carried out with a selection of thirty-six significant executive producers and writers of contemporary American TV series. The findings indicate the relevance of this profile from a historical perspective, and particularly in recent years. Although there is a basic scheme of tasks developed by the showrunner in each phase of the production process, we find differences in this actuation due to personal –sex and nationality– and professional –format/gender and channel– characteristics in this industrial context. The showrunner develops an executive-creative dual profile to maintain the project’s coherence according to the established vision. Their influence over the TV series’ creative features contributes to reflection on television authorship and its attribution to this figure.Government of Spain FPU 15/00737Project National Plan "Transmedializacion y crowdsourcing en las narrativas de ficcion y no ficcion audiovisuales, periodisticas, dramaticas y literarias" (2018-2020) CSO2017-85965-PUniversity of Granad

    Weighted Lp-boundedness of Fourier series with respect to generalized Jacobi weights

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    Let w be a generalized Jacobi weight on the interval [-1,1] and, for each function f, let Snf denote the n-th partial sum of the Fourier series of f in the orthogonal polynomials associated to w. We prove a result about uniform boundedness of the operators Sn in some weighted Lp spaces. The study of the norms of the kernels Kn related to the operators Sn allows us to obtain a relation between the Fourier series with respect to different generalized Jacobi weights

    Econometrics and Free Software: A Fruitful Binomial Teaching

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    En el Grado en Economía, en tercer curso, se imparten dos asignaturas relacionadas con la Econometría. La que aparece en segundo lugar, Métodos Avanzados de Econometría, tiene un enfoque eminentemente práctico que exige el uso de material informático sofisticado y que, hasta hace poco, tenía alto coste en el mercado, y por tanto, prohibitivo para nuestros estudian - tes. El hecho de disponer ahora de un software libre econométrico, GRETL, nos ha permitido desarrollar con total naturalidad todos los objetivos de la asignatura, consiguiendo para los estu- diantes un aprendizaje práctico a partir de datos reales, proporcionando a los mismos una visión global, eficaz y útil, de una disciplina que para el profesional de la Economía se convertirá en un instrumento fundamental para sus investigaciones futuras. Los resultados obtenidos entre nuestros alumnos son completamente satisfactorios.We teach two subjects related to Econometrics within the third year of the Degree in Eco- nomics. The second of them, Advanced Methods in Econometrics, has a practical approach and therefore it is necessary the use of specific software which until now had a prohibitive price for our students. However, we could carry out all the objectives of the subject using the free software GRETL. It has allowed our students learn practicing from real data, providing them a global, effective and useful overview of a subject that will be essential for their coming research in Economics. The results obtained with our students have been entirely satisfactor
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