Chinchillidae and Dolichotinae rodents (Rodentia: Hystricognathi: Caviomorpha) from the late Pleistocene of Southern Brazil

New records of rodents from the late Pleistocene Chuí Creek, Rio Grande do Sul State, southern Brazil, are here described. A partial dentary with fragmented cheek teeth is identified as Chinchillidae, Lagostomus Brookes cf. L. maximus (Desmarest). Other two specimens are identified as cheek teeth of Dolichotinae indet. (Caviidae). Pleistocene fossils of Lagostomus were previously reported for Argentina and Uruguay. The material of Lagostomus from Chuí Creek represents the first confidently record of this taxon Brazil. Pleistocene fossil remains of Dolichotinae have been found in Argentina, Uruguay and other areas of southern Brazil, though the Brazilian find lack precise stratigraphic information. These new records widen the paleobiogeographic distribution of Lagostomus and confirm the presence of Dolichotinae during the late Pleistocene of southern Brazil.Fil: Kerber, Leonardo. Fundação Zoobotânica do Rio Grande do Sul; BrasilFil: Pereira Lopes, Renato. Universidade Federal do Rio Grande do Sul; BrasilFil: Vucetich, María Guiomar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ribeiro, Ana Maria. Fundação Zoobotânica do Rio Grande do Sul; BrasilFil: Pereira, Jamil. Museu Coronel Tancredo Fernandes de Mello; Brasi

Escrituras de terra e de auga: Palabras e imaxes sobre a desposesión

S’analitzen els discursos literaris i interartístics centrats en la desposses- sió de l’espai a Galícia com a conseqüència de l’acció humana (espoli energètic, incendis, marees negres, contaminació).Literary and inter-artistic discourses centred on the dispossession of space in Galicia as a consequence of human action will be analysed (energy spoliation, fires, oil spills, pollution). The literary texts selected with the corresponding images, as well as showing aspects such as eucalyptization, depopulation, desiccation, overexploitation, etc., reflect the loss of ecological and environmentally friendly ways of life and, ultimately, the dispossession of identity.Analizaranse os discursos literarios e interartísticos centrados na desposesión do espazo en Galicia como consecuencia da acción humana (espolio enerxético, incendios, mareas negras, contaminación). Os textos literarios seleccionados coas imaxes correspondentes, ademais de mostrar aspectos como a eucaliptización, o despoboamento, a desecación, a sobreexplotación etc. reflicten a perda de modos de vida ecolóxicos e respectuosos co medio e, en último termo, a desposesión da identidade

Silencio, memoria y documentos de sombra. Desmemorias y relatos sobre larepresión durante la Guera Civil

El objetivo de nuestro trabajo es acercarnos a la memoria de un hecho traumático, la represión que tuvo lugar en Galicia durante los años de la guerra civil (1936-1939). Indagaremos en los procesos de olvido, de narración, de selección de recuerdos y reconstrucción que ha habido sobre aquel episodio traumático que puede ser considerado en términos de «desmemoria» social. Para ello, analizaremos el caso gallego, y lo haremos desde el punto de vista de la Historia Social y de la Literatura. Esto es, nos interesaremos tanto por la construcción de la memoria social (en oposición a la memoria oficial impuesta por el poder) y las narraciones de las que se nutre (llenas estas de silencios, memorias fraccionadas, memorias tullidas, etc.) como por la memoria construida a través de los relatos que de la represión franquista y de sus efectos se han elaborado por parte de autores literarios. Como veremos, ambas memorias, la social y la construida vía literatura, comparten trazos y están llenas de silencios y desmemorias, aunque también jalonadas de denuncia.The aim of our paper is to approach the memory of a traumatic event - the repression that took place in Galicia during the years of the Civil War (1936-1939). We investigate the processes of forgetting, of narrating, of selection of remembrances and of reconstruction undertaken for that traumatic event which is to be considered in terms of «collective oblivion». To this end, we analyze the Galician case both from the point of view of Social History and from that of Literature. Thus we are interested in the construction of social memory - as opposed to official memory imposed by power - and the narratives that feed it - filled with silences, divided memories, mutilated memories etc. –, as well as in the memory constructed by literary authors through stories about the Francoist repression and its effects. As we shall see, both memories – the social memory and the memory constructed via literature - share features and are filled with silence and forgetfulness, but also dotted with complain

Exploratory study on the relationships among conceptual knowledge, domain of mathematical techniques and visions of the Mathematics in the Physics and in the resolution of problems on the First Law of the Thermodynamics

Nos últimos anos têm se destacado a importância da compreensão conceitual e sua ligação com a formalização matemática de conceitos, dado que a Matemática constitui-se no esqueleto que sustenta o corpo da Física, porém são escassas as pesquisas que discutam como estudantes avançados de cursos de Física entendem as equações matemáticas e qual o seu papel na aprendizagem de conceitos físicos. Este trabalho é um recorte de uma pesquisa mais ampla, que tem como objetivo investigar o papel da Matemática na compreensão de conceitos físicos e mais especificamente dos conceitos envolvidos na primeira lei da Termodinâmica. Os dados obtidos neste estudo descritivo, realizado com 22 estudantes do último ano do curso de Licenciatura em Física da Universidade Estadual da Paraíba (Brasil), parecem mostrar a importância da compreensão não apenas dos conceitos ou das técnicas matemáticas isoladamente, mas sim da formalização matemática ligada à construção dos conceitos para que a aprendizagem ocorra de maneira efetiva. Isto se manifesta de forma mais evidente na resolução de problemas. Outro ponto que emerge deste estudo é que parece existir uma relação entre a aprendizagem de conceitos físicos e a resolução de problemas com a visão epistemológica que os estudantes têm do papel da Matemática na FísicaIn the last years, physics teaching researchers have stressed the relation between the conceptual comprehension and the mathematical formalism in the learning of physics, because Mathematics occupies the place of the internal structure in the body of the Physical science. Nevertheless, few studies argue how undergraduate advanced students of Physics understand mathematical equations and what is their role in the learning of physical concepts. This work is part of a broad research which investigates the role of mathematics in the comprehension of physical concepts related to the First Law of Thermodynamics. The data of this descriptive study deal with 22 students of the last year of a degree course in Physics of State University of Paraiba (Brasil). The data was gathered by non-participate observation, a questionnaire with straight questions, regularly discipline’s evaluation and individual interviews. The analysis shows that an effective learning requires a link between the mathematical formalism and the construction of concepts, and not only the isolated comprehension of concepts and/or the knowledge of mathematical techniques. This link seems to be more evident in problem solving. Also, it appears to be a relation between the learning of physical concepts and problem solving and how students understand the role of Mathematics in Physics theorie

Toxic cyanobacteria strains isolated from blooms in the Guadiana River (southwestern Spain)

This paper describes the occurrence of toxic cyanobacteria along the Guadiana River over its course between Mérida and Badajoz (Extremadura, Spain). Water sampling for phytoplankton quantification and toxin analysis was carried out regularly between 1999 and 2001 in six different locations, including two shallow, slow-flowing river sites, two streamed river sites and two drinking water reservoirs. The cyanobacterial community differed significantly between these locations, especially during the summer. The predominant genera were Microcystis, Oscillatoria, Aphanizomenon and Anabaena. Using an ELISA assay the total microcystin contents of natural water samples from the most eutrophic locations ranged from 0.10 – 21.86 µg mcyst-LR equivalent·L-1 in Valdelacalzada and 0.10-11.3 µg mcyst-LR equivalent·L-1 in Vitonogales, and a seasonal variation of toxin content was observed. The amount of microcystins produced by each strain was determined by ELISA assay and the detection and identification of microcystin variants of three toxic strains of Microcystis aeruginosa was performed by high performance liquid chromatography (HPLC). The analysis of microcystins of the cultured strains revealed that toxin production was variable among different strains of M. aeruginosa isolated either from different blooms or from the same bloom.Junta de Andalucía (CTS358

Chinchillidae and Dolichotinae rodents (Rodentia: Hystricognathi: Caviomorpha) from the late Pleistocene of southern Brazil

New records of rodents from the late Pleistocene Chuí Creek, Rio Grande do Sul State, southern Brazil, are here described. A partial dentary with fragmented cheek teeth is identified as Chinchillidae, Lagostomus Brookes cf. L. maximus (Desmarest). Other two specimens are identified as cheek teeth of Dolichotinae indet. (Caviidae). Pleistocene fossils of Lagostomus were previously reported for Argentina and Uruguay. The material of Lagostomus from Chuí Creek represents the first confidently record of this taxon Brazil. Pleistocene fossil remains of Dolichotinae have been found in Argentina, Uruguay and other areas of southern Brazil, though the Brazilian find lack precise stratigraphic information. These new records widen the paleobiogeographic distribution of Lagostomus and confirm the presence of Dolichotinae during the late Pleistocene of southern Brazil. Sociedade Brasileira de Paleontologia.Este trabalho reporta novos materiais de roedores provenientes dos depósitos fossilíferos do arroio Chuí (Rio Grande do Sul, sul do Brasil). O material de Chinchillidae é identificado como Lagostomus Brookes cf. L. maximus (Desmarest) e é representado por um dentário esquerdo faltando sua região posterior, com o incisivo preservado e a série p4-m3 fragmentada. Os outros dois espécimes são identificados como molariformes de Dolichotinae indet. (Caviidae). Os fósseis de Lagostomus durante o Pleistoceno estavam restritos a Argentina e Uruguai. O material aqui reportado caracteriza o primeiro registro seguro deste táxon no Brasil. Fósseis de Dolichotinae têm sido encontrados em depósitos pleistocênicos da Argentina, Uruguai e sul do Brasil, porém este último provém de uma localidade sem contexto estratigráfico preciso. Desta forma, estes novos registros ampliam a distribuição paleobiogeográfica de Lagostomus e confirmam a presença de Dolichotinae durante o Pleistoceno final do sul do Brasil.Facultad de Ciencias Naturales y Muse

Diseño de una campaña de concientización sobre la utilización del comercio electrónico para las Pymes del sector turístico - hotelero del departamento de Rivas.

Tesis (Licenciado en Mercadeo y Publicidad)--Universidad Americana, Managua, 2008El objetivo de este estudio es el diseño de una campaña de concientización a las PYMES para que los empresarios conozcan su importancia y los beneficios que se obtiene con la utilización del comercio electrónico. Para esto, se investigarán las condiciones actuales de las empresas

Contact detection between a small ellipsoid and another quadric

[Abstract] We analyze the characteristic polynomial associated to an ellipsoid and another quadric in the context of the contact detection problem. We obtain a necessary and sufficient condition for an efficient method to detect contact. This condition, named smallness condition, is a feature on the size and the shape of the quadrics and can be checked directly from their parameters. Under this hypothesis, contact can be noticed by means of the expressions in a discriminant system of the characteristic polynomial. Furthermore, relative positions can be classified through the sign of the coefficients of this polynomial. As an application of these results, a method to detect contact between a small ellipsoid and a combination of quadrics is given

Classification of the relative positions between a small ellipsoid and an elliptic paraboloid

©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/. This version of the article Brozos-Vázquez, M., Pereira-Sáez, M. J., Souto-Salorio, M. J., & Tarrío-Tobar, A. D. (2019). “Classification of the relative positions between a small ellipsoid and an elliptic paraboloid” has been accepted for publication in Computer Aided Geometric Design, 72, 34–48. The Version of Record is available online at https://doi.org/10.1016/j.cagd.2019.05.002.[Abstract]: We classify all the relative positions between an ellipsoid and an elliptic paraboloid when the ellipsoid is small in comparison with the paraboloid (small meaning that the two surfaces cannot be tangent at two points simultaneously when one is moved with respect to the other). This provides an easy way to detect contact between the two surfaces by a direct analysis of the coefficients of a fourth degree polynomial.The authors wish to thank the referees for extremely valuable comments and suggestions, which were essential to improve the final version of the paper. Supported by Projects ED431F 2017/03, TIN2017-85160-C2-1-R, MTM2016-75897-P and MTM2016-78647-P (AEI/FEDER, UE).Xunta de Galicia; ED431F 2017/0

Optimización de una técnica para la observación de cromosomas mitóticos de especies de Passiflora L.

La necesidad de optimización de una técnica que permita la visualización de cromosomas mitóticos surgió de resultados poco satisfactorios de otros protocolos de coloración ensayados, tales como técnicas de tinción con ácido acético 45% para observación con microscopio de contraste de fases, hematoxilina acética, orceína acética 2% y carmín acético 2% (sin mordiente). El objetivo del presente trabajo fue desarrollar una técnica para la observación reiterada de cromosomas mitóticos en raicillas de especies del género Passiflora.Fil: Pereira S., Claudia. Universidad Nacional de Asuncion; Paraguay;Fil: Honfi, Ana Isabel. Universidad Nacional de Misiones. Facultad de Cs.exactas Quimicas y Naturales. Laboratorio de Citogenetica Vegetal; Argentina;Fil: Deginani, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion (i); Argentina;Fil: Ferrucci, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina