884 research outputs found

    Influencing Factors of Infestation of Endo and Ectoparasites on Hair Sheep in Tropical Ecuador

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    120 hair sheep were tested for faecal, skin and blood parasites. After three parasitological studies in humid Sucumbíos, it was proved that the parasitic charge is influenced by different factors. In the case of air temperature and humidity there was no variation detected between the seasons, although the parasitical charge rose in the course of this study. With regard to parasitic charge some systematic differences were found between the farming systems. Prophylactic measures such as rotational grazing, guarantee the food alternatives in the case of grass shortage, the strategic treatment with de-wormers and removal of excrement and garbage were recommended

    Understanding pit sites: storage, surplus and social complexity in Prehistoric Western Europe.

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    This is a pre-print of an article published in Journal of Archaeological Method and Theory. The final authenticated, peer-reviewed version is available online at: https://doi.org/10.1007/s10816-019-09429-7The importance of pits for archaeological inference can hardly be overstated, given their virtual omnipresence in the archaeological record. In Prehistoric Europe pits occasionally form large concentrations known as ‘pit sites’, where they are the most visible, sometimes the sole, remnants of past human activity. If we follow the generally accepted view of pits as grain storage containers, how can we interpret the social role played by places comprising hundreds or even thousands of pits? This paper is an attempt to shed light on this topic by summarising and critically analysing much of the current knowledge on storage of grain in non-industrial societies. We will start by gathering relevant and up-to-date experimental, ethnographic and historical data about the challenges that the storage of grain poses and how pits may have helped Prehistoric communities to overcome them. This will be followed by a discussion of their advantages and disadvantages relative to other methods: why would anybody use airtight pits instead of, for instance, weather-proofed raised granaries? Next, we will undertake an examination of the social and economic contexts in which storage pits are an effective solution as opposed to those in which their performance is far from optimal. The conclusions drawn will serve as a background against which to evaluate current interpretations concerning three selected case studies in Prehistoric Western Europe.The research leading to these results has received funding from the PEOPLE Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement nº 2012-326129

    Genomic comparative analysis of the environmental Enterococcus mundtii against enterococcal representative species

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    Background Enterococcus mundtii is a yellow-pigmented microorganism rarely found in human infections. The draft genome sequence of E. mundtii was recently announced. Its genome encodes at least 2,589 genes and 57 RNAs, and 4 putative genomic islands have been detected. The objective of this study was to compare the genetic content of E. mundtii with respect to other enterococcal species and, more specifically, to identify genes coding for putative virulence traits present in enterococcal opportunistic pathogens. Results An in-depth mining of the annotated genome was performed in order to uncover the unique properties of this microorganism, which allowed us to detect a gene encoding the antimicrobial peptide mundticin among other relevant features. Moreover, in this study a comparative genomic analysis against commensal and pathogenic enterococcal species, for which genomic sequences have been released, was conducted for the first time. Furthermore, our study reveals significant similarities in gene content between this environmental isolate and the selected enterococci strains (sharing an “enterococcal gene core” of 805 CDS), which contributes to understand the persistence of this genus in different niches and also improves our knowledge about the genetics of this diverse group of microorganisms that includes environmental, commensal and opportunistic pathogens. Conclusion Although E. mundtii CRL1656 is phylogenetically closer to E. faecium, frequently responsible of nosocomial infections, this strain does not encode the most relevant relevant virulence factors found in the enterococcal clinical isolates and bioinformatic predictions indicate that it possesses the lowest number of putative pathogenic genes among the most representative enterococcal species. Accordingly, infection assays using the Galleria mellonella model confirmed its low virulenceFil: Repizo, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Espariz, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Blancato, Victor Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Suárez, Cristian Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Esteban, Luis. Universidad Nacional de Rosario. Facultad de Cs.médicas. Escuela de Cs.médicas. Cátedra de Fisiología; ArgentinaFil: Magni, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin

    The assessment in the Primary Education classroom. Key factor for the learning science and mathematics

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    En este artículo se presenta una experiencia desarrollada en un aula de 6º de primaria. Después de una breve justificación de la perspectiva desde la que se fueron tomando las decisiones presentamos la propuesta desarrollada en torno a un proceso de evaluación. Dicho proceso está basado en el seguimiento del reconocimiento y superación del error por parte de los alumnos en relación con el conocimiento de las facciones y su combinación, como parte fundamental para entender aspectos relacionados con la proporcionalidad

    Expression of the Agmatine Deiminase Pathway in Enterococcus faecalis Is Activated by the AguR Regulator and Repressed by CcpA and PTSMan System

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    Although the agmatine deiminase system (AgDI) has been investigated in Enterococcus faecalis, little information is available with respect to its gene regulation. In this study we demonstrate that the presence of exogenous agmatine induces the expression of agu genes in this bacterium. In contrast to the homologous and extensively characterized AgDI system of S. mutants, the aguBDAC operon in E. faecalis is not induced in response to low pH. In spite of this, agmatine catabolism in this bacterium contributes by neutralizing the external medium while enhancing bacterial growth. Our results indicate that carbon catabolic repression (CCR) operates on the AgDI system via a mechanism that involves interaction of CcpA and PSer- HPr with a cre site found in an unusual position considering the aguB promoter (55 nt upstream the +1 position). In addition, we found that components of the mannose phosphotransferase (PTSMan) system also contributed to CCR in E. faecalis since a complete relief of the PTS-sugars repressive effect was observed only in a PTSMan and CcpA double defective strain. Our gene context analysis revealed that aguR is present in oral and gastrointestinal microorganisms. Thus, regulation of the aguBDAC operon in E. faecalis seems to have evolved to obtain energy and resist low pH conditions in order to persist and colonize gastrointestinal nichesFil: Suárez, Cristian Alejandro. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Biologia Molecular y Celular de Rosario;Fil: Espariz, Martin. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Biologia Molecular y Celular de Rosario;Fil: Blancato, Victor Sebastian. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Biologia Molecular y Celular de Rosario;Fil: Magni, Christian. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Rosario. Instituto de Biologia Molecular y Celular de Rosario

    Historia de vida del programa ciencias del deporte y la recreación – UTP : Una caracterización histórica de los estudiantes 1991-2015

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    La siguiente investigación se adentra en el programa de Ciencias del Deporte y la Recreación, en especial de sus estudiantes. El trabajo tiene como eje central la tendencia histórica de las características (edad, colegio, departamento de procedencia, entre otras) de los estudiantes desde 1991, el momento en que inicia labores el programa, hasta finales del 2015. Además de esto busca dar un panorama más amplio de estas características, por medio de un conjunto de documentos históricos del programa; y, no siendo suficiente, llega hasta la misma historia de la educación superior colombiana

    Análisis de curvas de retención de agua en suelos granulares con diferentes contenidos de finos, obtenidas empleando metodologías modernas.

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    InvestigaciónEn este trabajo se propuso analizar la retención hídrica en cinco muestras granulares (arena de guamo) con diferentes contenidos de finos (caolín amarillo) para determinar si la influencia del material fino es directamente proporcional a la retención hídrica en las muestras. Para la elaboración de curvas de retención hídrica se emplearon los equipos Hyprop 2 y WP4C, los cuales son capaces de determinar la succión matricial de las muestras a ciertos contenidos volumétricos de agua en estado saturado y seco, respectivamente.1. RESUMEN / ABSTRACT 2. INTRODUCCIÓN 3. ANTECEDENTES Y JUSTIFICACIÓN 4. PLANTEAMIENTO Y FORMULACIÓN DEL PROBLEMA 5. ALCANCES Y LIMITACIONES 6. OBJETIVOS 6.1. OBJETIVO GENERAL 6.2. OBJETIVOS ESPECÍFICOS 7. MARCO TEÓRICO 8. MARCO CONCEPTUAL 9. MARCO LEGAL 10. METODOLOGÍA EMPLEADA11. RESULTADOS OBTENIDOS12. ANÁLISIS DE RESULTADOS 13. CONCLUSIONES Y RECOMENDACIONES 14. REFERENCIASPregradoIngeniero Civi

    Interaction of water with methanesulfonic acid on Pt single crystal electrodes

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    The electrochemical behavior of methanesulfonic acid on platinum single crystal electrode surfaces is investigated by cyclic voltammetry and infrared spectroscopy measurements. The results are compared with the voltammetric profiles of perchloric and trifluoromethanesulfonic acids. The differences are interpreted in terms of the effect of the anion on the structure of water. No adsorbed species are detected by infrared spectroscopy.APS acknowledges the scholarship “Estudiantes sobresalientes de posgrado” at the UNC and COLCIENCIAS National Doctoral Scholarship (567). MFS acknowledges the support of UNC (Research Project 19030). JMFwould like to thankGeneralitat Valenciana (Feder) through project PROMETEOII/2014/013
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