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Search Results: 1 - 10 of 183 matches for " SABBE; CRUCES "
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Paleolimnological studies of Laguna Chica of San Pedro (VIII Region): Diatoms, hydrocarbons and fatty acid records Estudio Paleolimnológico de Laguna Chica de San Pedro (VIII Región): Diatomeas, hidrocarburos y ácidos grasos
ROBERTO URRUTIA,SABBE KOEN,FABIOLA CRUCES,KARLA POZO
Revista chilena de historia natural , 2000,
Abstract: Diatom, hydrocarbons and fatty acid sedimentary records were used for reconstructing the recent (last 150 years) palaeolimnological history of Laguna Chica of San Pedro (Concepción, VIII Región, Chile). Cluster analyses (Constrained Incremental Sum of Squares) on the diatom data revealed three distinct periods. The first period (1883-1940's) showed a pronounced increase in sedimentation rate and a slight increase in organic matter accumulation. In this period, eutrophic species (Aulacoseira granulata and Staurosira construens) became increasingly dominant. From the 1940s until the 1970s the diatom signal is more equivocal: after the initial decrease in the relative abundance of A. granulata and S. construens their numbers fluctuate without a clear pattern. Sedimentation rates strongly fluctuate in this period. From 1978 onwards eutrophic species are in decline while indicators of oligotrophic conditions, such as Cyclotella stelligera and Aulacoseira distans, become more abundant. This shift in the lake trophic status could not be attributed to a reduction in the nutrient load from the catchment and we hypothesize that the invasion of the lake by the submersed macrophyte Egeria densa has altered nutrient availability to the plankton communities. This is in agreement with the hydrocarbons and fatty acid analyses which demonstrate a shift in carbon number distributions from short chain alkanes and alkanoic acids (typical for microalgae) to long chain molecules (characteristic for higher plants) in the upper layers of the lake sediment Se realizó la reconstrucción histórica de los últimos 150 a os de Laguna Chica de San Pedro (Concepción, VIII Región, Chile), a través de la utilización de los restos de diatomeas, hidrocarburos y ácidos grasos contenidos en la columna de sedimento. El análisis estratigráfico de las diatomeas reveló la presencia de tres períodos diferentes. El primer período (1883-1940's), mostró un marcado aumento de las tasas de sedimentación y un leve aumento en la acumulación de materia orgánica; en este período se registra un incremento de las especies eutróficas (Aulacoseira granulata y Staurosira construens). Desde los a os cuarenta hasta la década del setenta el cambio en la comunidad de diatomeas fue más evidente y las tasas de sedimentación variaron fuertemente. A partir de 1978 disminuyen las especies eutróficas y aumentan las indicadoras de condiciones oligotróficas (Cyclotella stelligera y Aulacoseira distans). El cambio en el estado trófico del lago, no se atribuye a una reducción de los aportes de nutrientes desde la cuenca, si
Paleolimnological studies of Laguna Chica of San Pedro (VIII Region): Diatoms, hydrocarbons and fatty acid records
URRUTIA,ROBERTO; KOEN,SABBE; CRUCES,FABIOLA; POZO,KARLA; BECERRA,JOSE; ARANEDA,ALBERTO; VYVERMAN,WIM; PARRA,OSCAR;
Revista chilena de historia natural , 2000, DOI: 10.4067/S0716-078X2000000400014
Abstract: diatom, hydrocarbons and fatty acid sedimentary records were used for reconstructing the recent (last 150 years) palaeolimnological history of laguna chica of san pedro (concepción, viii región, chile). cluster analyses (constrained incremental sum of squares) on the diatom data revealed three distinct periods. the first period (1883-1940's) showed a pronounced increase in sedimentation rate and a slight increase in organic matter accumulation. in this period, eutrophic species (aulacoseira granulata and staurosira construens) became increasingly dominant. from the 1940s until the 1970s the diatom signal is more equivocal: after the initial decrease in the relative abundance of a. granulata and s. construens their numbers fluctuate without a clear pattern. sedimentation rates strongly fluctuate in this period. from 1978 onwards eutrophic species are in decline while indicators of oligotrophic conditions, such as cyclotella stelligera and aulacoseira distans, become more abundant. this shift in the lake trophic status could not be attributed to a reduction in the nutrient load from the catchment and we hypothesize that the invasion of the lake by the submersed macrophyte egeria densa has altered nutrient availability to the plankton communities. this is in agreement with the hydrocarbons and fatty acid analyses which demonstrate a shift in carbon number distributions from short chain alkanes and alkanoic acids (typical for microalgae) to long chain molecules (characteristic for higher plants) in the upper layers of the lake sediment
Philosophie der neuesten Musik-ein Versuch zur Extrapolation von Adornos 'Philosophie der neuen Musik'
H. Sabbe
Philosophica , 1971,
Abstract:
Isometric coactions of compact quantum groups on compact quantum metric spaces
Johan Quaegebeur,Marie Sabbe
Mathematics , 2010,
Abstract: We propose a notion of isometric coaction of a compact quantum group on a compact quantum metric space in the framework of Rieffel where the metric structure is given by a Lipnorm. We prove the existence of a quantum isometry group for finite metric quantum spaces, preserving a given state.
Balance con memoria (Bolero)
Cruces, Francisco;
Alteridades , 2008,
Abstract: in this text, that is more of an oral nature than a written one and more biographical than academic, the author celebrates the extensive academic career of the grupo de estudios urbanos (urban studies group) of uam-i and asks himself about the narratives by which this group has tried to account for life in mexico city. to tell stories about the city is to in-dissolubly weave tales about ourselves.
Etnografías sin final feliz. Sobre las condiciones de posibilidad del trabajo de campo urbano en contextos globalizados
Cruces, Francisco
Revista de Dialectología y Tradiciones Populares , 2003,
Abstract: What is the epistemological justification for current ethnography, at a time when the flux of persons, knowledge and meanings erodes any closed, self-contained sense of culture? What will be the theoretical role played by key concepts such as culture , community and place, until now used to lay the groundwork for our routines of research? On the basis of this deep transformation underway of the contextual conditions for ethnography, this paper explores some of them, focusing on three problems: (1) holism, (2) the nature of contemporary chronotopy and (3) the incommensurability of knowledge. Far from an abandonment of ethnography as a method, the author argues for the heuristic potential of ethnographic interpretation for reconstructing the unexpected connections among distant cultural realities in a temporally and spatially single world. Qué justificación epistemológica cabe dar hoy a la actividad etnográfica en contextos donde el flujo de personas, saberes y significados erosiona todo sentido cerrado, autocontenido, de cultura? Qué lugar seguir concediendo a los conceptos clave que apuntalaban nuestras rutinas de investigación, a palabras tales como lugar , comunidad o cultura ? Partiendo de la premisa de una transformación radical en las condiciones contextúales en que hemos de desplegar nuestra práctica profesional, el presente artículo trata de caracterizarlas, centrándose en (1) el problema del holismo, (2) la naturaleza de la cronotopía contemporánea y (3) la inconmensurabilidad de saberes. Lejos de un abandono de la etnografía como método, este análisis trata de argumentar el potencial heurístico de la interpretación etnográfica para reconstruir las conexiones inesperadas entre realidades culturales distantes en un mundo unificado espacial y temporalmente.
Estadios Sede
Cruces, Eduardo
Informes de la Construccion , 1981,
Abstract: Not available. Alicante: Estadio Rico Pérez Barcelona: Estadio Nou Camp Barcelona: Estadio de Sarria Bilbao: Estadio San Mames Elche: Nuevo Estadio Gijón; Estadio El Molinón La Coru a: Estadio Riazor Madrid: Estadio Santiago Bernabéu Madrid: Estadio Vicente Calderón Málaga: Estadio La Rosaleda Oviedo: Estadio Carlos Tartiere Sevilla: Estadio Sánchez Pizjuán Sevilla: Estadio Benito Villannarin Valencia: Estadio Luis Casanova Val adolid: Estadio José Zorrilla Vigo: Estadio Balaídos Zaragoza: Estadio La Romareda
Mauricio Ramia: el proceso de hacerse investigador
Cruces,José Miguel;
Acta Botánica Venezuelica , 2010,
Abstract: this manuscript examines mauricio ramia?s career as a researcher in the field of savanna ecology in venezuela. after more than 50 years of endeavor, his work stands out as one that has been built and decanted through discipline, intuition and perseverance. his effort is acknowledged and valued by all the specialists in this field in the country as a baseline contribution to subsequent analysis in the ecology of this ecosystem in venezuela. his legacy is expressed in a considerable number of publications, as well as in the formation and motivation of a significative group of students and professionals.
DIATOMEAS (BACILLARIOPHYCEAE) DE ZONAS ANDINAS DEL NORTE DE CHILE: NUEVA LOCALIDAD GEOGRáFICA PARA HALOROUNDIA SPECIOSA (HUSTEDT) DIAZ ET MAIDANA
Rivera,Patricio; Cruces,Fabiola;
Gayana. Botánica , 2009, DOI: 10.4067/S0717-66432009000200013
Abstract: this note reports the first finding of haloroundia speciosa (hustedt) diaz et maidana (bacillariophyceae) in a sample collected from the salar de aguas calientes, loa province, northern chile (23°30's; 67°33'w). this species is restricted to the andes mountains. comments about its morphological features and geographical distribution in north andean areas are given.
THALASSIOTHRIX SPATHULATA HASLE (THALASSIONEMATACEAE, BACILLARIOPHYCEAE): PRIMER REGISTRO PARA LA FLORA DIATOMOLOGICA MARINA DE CHILE
Rivera,Patricio; Cruces,Fabiola;
Gayana. Botánica , 2005, DOI: 10.4067/S0717-66432005000100009
Abstract: we report the first finding of thalassiothrix spathulata in the marine phytoplankton of chile. the species was common in samples collected between 18o16's and 28o06's. principal morphological features are described and illustrated
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