2,920 research outputs found

    Creativity, pedagogical, and educational innovation: analysis of the perception of a group of Chilean teachers

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    Este estudio se circunscribe al ámbito de la educación, la didáctica y la metodología en el trabajo de aula. Se analizan los resultados de una investigación con enfoque cuantitativo, que tuvo por objetivo identificar la percepción y experiencias acerca de la creatividad, innovación pedagógica y educativa -estas dos últimas nociones no siempre claras y distinguibles en la teoría y los estudios empíricos- en un grupo de docentes que recién inicia su proceso de formación en un programa de postgrado de Magíster en Didáctica, dictado por la Escuela de Educación del Campus Los Ángeles de la Universidad de Concepción, de la provincia y región de Biobío, Chile. La investigación tuvo un alcance descriptivo y como principal técnica de recolección de datos se utilizó un cuestionario de opinión con preguntas abiertas. Los principales hallazgos señalan que el profesorado en general y en un porcentaje mayoritario valora la creatividad, entiende el concepto de innovación pedagógica, pero tiene dificultades para identificar la diferencia entre esta última y la innovación educativa debido a su amplitud conceptual. Además, los resultados señalan que si bien el profesorado cree que la innovación es necesaria y tiene buena predisposición a ella en el ámbito de su labor pedagógica-docente, no siempre se generan las condiciones favorables para su implementación en los establecimientos educativos.This study is circumscribed to the scope of education, didactics, and classroom methodology. The results of an investigation with a quantitative approach will be analyzed, whose aim was to identify the perception and experiences related to creativity, as well as to pedagogical and educational innovation - the two latter concepts not always clear and distinguishable in theory and empirical studies. The research was done in a group of teachers who were just beginning their training process in a Graduate Degree in Didactics, taught in the School of Education at the Los Angeles Campus of the Universidad de Concepción, in the region of Biobío, Chile. The investigation had a descriptive approach and the main method for data collection was an opinion questionnaire with open questions. The main findings show that teachers in general and in a high percentage appreciate creativity, understand the concept of pedagogical innovation, but have difficulties to identify the difference between the latter and educational innovation due to its conceptual breadth. Furthermore, the results show that while teachers believe that innovation is necessary and that they are willing to do it in their pedagogical teaching activity, favorable conditions to implement it in schools are not always generated

    Full Bayesian analysis for a class of jump-diffusion models

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    A new Bayesian significance test is adjusted for jump detection in a diffusion process. This is an advantageous procedure for temporal data having extreme valued outliers, like financial data, pluvial or tectonic forces records and others.Comment: 15 pages, 7 figures; real data analysis adde

    Sustitución ureteral bilateral con asa ileal

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    Indexación: Web of Science; ScieloUreteral replacement by a loop of defunctionalized ileum was described more than 2 centuries ago and continues to be a therapeutic option at present. This series describes the technique of bilateral ureteral replacement with ileum. Aim: To report 4 cases of bilateral ileal ureteral replacement performed at our institution, its indications, the surgical technique, complications, and a review of the literature. Material and Method: We report 4 cases of extensive bilateral ureteral injury of different etiologies, whose treatment with curative intent was to replace the damaged ureter with a isoperistaltic small bowel segment. Results: The surgical technique used was standard in all cases. There were no intraoperative complications and only one patient had hyperchloremic acidosis. No patient has shown loss of renal function in the long-term follow up. Conclusion: Is an effective therapeutic, safe and reproducible technique to replacement of major bilateral ureteral injuries, independent of the original cause.La sustitución ureteral por un asa de íleon desfuncionalizada fue descrita hace más de 2 siglos y continúa siendo una alternativa terapéutica en la actualidad. Esta serie describe la técnica de sustitución ureteral bilateral con íleon. Objetivo: Presentar 4 casos de sustitución ureteral ileal bilateral realizados en nuestro centro, indicaciones de la técnica quirúrgica, complicaciones y revisión de la literatura. Material y Método: Presentamos 4 casos de lesión ureteral bilateral extensa, de etiologías diferentes, cuyo tratamiento con intención curativa fue la sustitución de la lesión ureteral por un segmento intestinal isoperis-táltico. Resultados: La técnica quirúrgica empleada fue estándar en todos los casos. No hubo complicaciones intraoperatorias, y sólo una paciente presentó descompensación metabólica por acidosis hiperclorémica. En ningún paciente se ha demostrado pérdida en la función renal. Conclusión: El segmento intestinal de íleon desfuncionalizado es una alternativa terapéutica eficaz, segura y reproducible, para el reemplazo de importantes lesiones ureterales bilaterales, independiente de la causa original.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-40262012000500012&nrm=is

    Un mundo diferente: las cuevas de osos. El caso de la cueva ce Amutxate (Aralar, Navarra)

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    Las campañas de excavación en la cueva de Amutxate en las que todo el sedimento fue lavado y cribado han permitido estudiar los aspecto taxonómicos de una típica acumulación de resto de oso de las cavernas. Se han recuperado más de 15000 restos de oso de las cavernas, menos de 20 restos de grandes mamíferos y cuatro piezas líticas. Los yacimientos de oso se presentan como el palimsesto de múltiples ocupaciones en las que el papel que juega el oso de las cavernas como acumulador de restos de otros mamíferos es despreciable. Palabras clave: Ursus spelaeus, tafonomía. distribución de edad, distribución de sexo, preservación anatómica

    Perspectiva paleobotánica y geológica de la biodiversidad en México

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    The origin of the extant vegetation and diversity of Mexico has a long history. Possibly the extent of this history is the point where the proposals differ, one states that the history begins in the Cretaceous (ca. 132 my) while other emphasize processes restricted to the Plio-Pleistocene (5.3 my), especially if referring the appearance of extant vegetation. Increased knowledge of the geological evolution of Mexico, and the constant change in physiography, along with the study of fossil angiosperms of the region, generates a clearer concept of how and when life forms differentiated and partnered. A hypothesis that combines geological processes and physiographic changes with the presence of plants and vegetation on the emerged continental parts is presented. It is proposed that existing biodiversity does indeed start ca. 132 million years ago, and although lineages that live in Mexico today can be recognized from this time, it is difficult to place their representants within a family, probably because they may represent members of the stem group. By the Paleogene (65-32 my) families, and even genera, that continue to live in Mexico are more easily recognized, but groups of extinct plants or plants growing today in other regions are still common. Based on the morphological/anatomical approach the Neogene (32-1.8 my) fossil plants resemble more those living naturally in Mexico, but still have important differences supporting the recognition of new species only. If in relatively recent times extant and fossil plants in Mexico seem closer based on their morphology/anatomy, it is to be expected that with the vegetation types a similar process can be recognized. The fossil record suggests that from communities that developed under hot-humid conditions in the Cretaceous, vegetation types with different capabilities to tolerate water stress, and communities that favored cool temperate conditions diverged. The process of divergence apparently occurred at two different times in two different regions. During the Paleogene it affected northern Mexico and during the Neogene it affected central and southern Mexico. Further geological and paleobotanical work will refine this proposal that suggests that changes that enable or constrain biological responses are part of other components of the Earth System.El origen de la vegetación actual de México y su diversidad tiene larga historia. Posiblemente es la extensión de esta historia el punto en que discrepan las propuestas, una planteando que inicia en el Cretácico (ca. 132 ma) y otras haciendo énfasis en procesos restringidos al Plio-Pleistoceno (5.3 ma), sobre todo si se refieren al origen de la vegetación actual. El aumento del conocimiento sobre la evolución geológica de México, y del constante cambio en su fisiografía, así como del estudio de las angiospermas fósiles de la región, genera un concepto más claro de cómo y cuándo las formas de vida fueron llegando y asociándose. Se presenta una hipótesis en la que se combinan procesos geológicos y cambios fisiográficos, con la presencia de plantas y vegetación en las partes emergidas que se van desarrollando. Se propone que la biodiversidad actual efectivamente inicia hace ca. 132 millones de años, aunque linajes que hoy viven en México se pueden reconocer desde este tiempo, es complicado ubicarlos en familias, pues posiblemente representen miembros del grupo troncal. En el Paleógeno (65-32 ma) las familias, y aun géneros, que continúan viviendo en el país son más fácilmente reconocidos, pero grupos extintos o que hoy crecen en otras regiones siguen siendo comunes. Es en el Neógeno (32-1.8 ma) que desde un punto de vista de la morfológico/anatómico las plantas fósiles se parecen más a las que viven de forma natural actualmente en el país, pero muestran diferencias que en general permiten proponer nuevas especies. Si las plantas fósiles y actuales de México se relacionan morfo/anatómicamente más solo en tiempos relativamente recientes, es de esperar que con los tipos de vegetación suceda algo similar. El registro fósil sugiere que a partir de comunidades que se desarrollaron bajo condiciones cálido-húmedas en el Cretácico, divergieron tipos de vegetación con capacidades diferentes ante el estrés hídrico, y comunidades que se favorecieron de condiciones templadas a frías. Esto sucede aparentemente en dos momentos distintos en dos regiones diferentes; durante el Paleógeno se afecta al norte y en al Neógeno al centro y sur del país. Trabajo geológico y paleobotánico conjunto y comparativo permitirá refinar esta propuesta que sugiere que los cambios que activan o restringen respuestas biológicas forman parte de otros componentes del Sistema Tierra

    Distribution of indium in the Ánimas - Chocaya - Siete Suyos District

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    The Ánimas - Chocaya - Siete Suyos district in SW Bolivia hosts a Bolivian-type polymetallic vein mineralization composed mostly of cassiterite, sphalerite, pyrite, galena, stannite, lead sulfosalts, tin sulfosalts and silver sulfosalts. In addition to base (Zn, Sn, Pb) and precious (Ag) metals, important concentrations of In have been described. Systematic EPMA analyses have revealed that the highest concentrations are found in an early generation of sphalerite (up to 9.66 wt% In) and in stannite (up to 4.11 wt% In). Although In-bearing sphalerites are relatively Fe-rich (mostly between 6.0 and 18.1 mol % FeS), the atomic concentrations of these two elements do not yield any correlation. In contrast, In is positively correlated with Cu mostly along a Cu/In = 1 proportion pointing to a (In3+ + Cu+ ) ¿ 2Zn2+ coupled substitution. A relatively high activity of Cu during the crystallization of In-rich sphalerite is also supported by exsolutions of chalcopyrite and stannite.Peer ReviewedPostprint (author's final draft

    A comprehensive structural, lectin and immunohistochemical characterization of the zebrafish olfactory system

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    Fish chemosensory olfactory receptors allow them to detect a wide range of water-soluble chemicals, that mediate fundamental behaviours. Zebrafish possess a well-developed sense of smell which governs reproduction, appetite, and fear responses. The spatial organization of functional properties within the olfactory epithelium and bulb are comparable to those of mammals, making this species suitable for studies of olfactory differentiation and regeneration and neuronal representation of olfactory information. The advent of genomic techniques has been decisive for the discovery of specific olfactory cell types and the identification of cell populations expressing vomeronasal receptors. These advances have marched ahead of morphological and neurochemical studies. This study aims to fill the existing gap in specific histological, lectin-histochemical and immunohistochemical studies on the olfactory rosette and the olfactory bulb of the zebrafish. Tissue dissection and microdissection techniques were employed, followed by histological staining techniques, lectin-histochemical labelling (UEA, LEA, BSI-B4) and immunohistochemistry using antibodies against G proteins subunits αo and αi2, growth-associated protein-43, calbindin, calretinin, glial-fibrillary-acidic-protein and luteinizing-hormone-releasing-hormone. The results obtained enrich the available information on the neurochemical patterns of the zebrafish olfactory system, pointing to a greater complexity than the one currently considered, especially when taking into account the peculiarities of the nonsensory epithelium.S

    Trace element distribution in the geological record of Roñanzas Peat Bog (Asturias, Northern Spain)

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    The Pb, Zn and Hg concentrations in the peat-bog samples of the Roñanzas record, that covers the last 8000 cal. BP, reveal a relationship with natural processes (climate, vulcanism) together with the atmospheric pollution linked to ancient minning, industrial activities, and agricultural development in northern Spain. There are metal enrichments along the peat profile probably related to the Roman Period, after 1700 AD and the Industrial Revolution and, in some cases, during the Visigod (Hg) and Islamic (Zn) Periods and Medieval Age (Pb, Zn). These processes are also observed in other European records, indicating that atmospheric pollution was produced globally, although with local particularitie

    Indium mineralization in the volcanic dome-hosted Ánimas–Chocaya–Siete Suyos polymetallic deposit, Potosí, Bolivia

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    A volcanic dome complex of Miocene age hosts the In-bearing Ánimas–Chocaya–Siete Suyos district in SW Bolivia. Ore mineralization occurs as banded and massive infillings in subvertical, NE-SW striking veins. In this article, a detailed petrographic study is combined with in situ mineral geochemistry determinations in ore from the Arturo, Chorro and Diez veins in the Siete Suyos mine, the Ánimas, Burton, Colorada, and Rosario veins in the Ánimas mine and the Nueva vein in the Chocaya mine. A three-stage paragenetic sequence is roughly determined for all of them, and includes (1) an early low-sulfidation stage that is dominated by cassiterite, pyrrhotite, arsenopyrite, and high-Fe sphalerite (FeS > 21 mol. %); (2) a second intermediate-sulfidation stage dominated by pyrite + marcasite ± intermediate product, sphalerite (FeS < 21 mol. %), stannite, and local famatinite; and, (3) a late intermediate-sulfidation stage dominated by galena and Ag-Pb-Sn sulfosalts. Electron-probe microanalyses reveal high indium enrichment in stage-2 sphalerite (up to 9.66 wt.% In) and stannite (up to 4.11 wt.% In), and a moderate enrichment in rare wurtzite (up to 1.61 wt.% In), stage-1 sphalerite (0.35 wt.% In), cassiterite (up to 0.25 wt.% In2O3), and ramdohrite (up to 0.24 wt.% In). Therefore, the main indium mineralization in the district can be associated to the second, intermediate-sulfidation stage, chiefly in those veins in which sphalerite and stannite are more abundant. Atomic concentrations of In and Cu in sphalerite yield a positive correlation at Cu/In = 1 that agrees with a (Cu+ + In3+) ¿ 2Zn2+ coupled substitution. The availability of Cu in the mineralizing fluids during the crystallization of sphalerite is, in consequence, essential for the incorporation of indium in its crystal lattice and would control the distribution of indium enrichment at different scales. The highest concentrations of indium in sphalerite, which is found in the Diez vein in the Siete Suyos mine, occur in crustiform bands of sphalerite with local “chalcopyrite disease” texture, which has not been observed in the other studied veins. In stannite, the atomic concentrations of In are negatively correlated with those of Cu and Sn at Cu + In = 2 and Sn + In = 1. Thus, atomic proportions and correlations suggest the contextualization of the main indium mineralization in the sphalerite–stannite–roquesite pseudoternary system.Peer ReviewedPostprint (published version
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