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Search Results: 1 - 10 of 1476 matches for " FABIOLA; POZO "
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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
Using an Interactive Computer System to Support the Task of Building the Notions of Ratio and Proportion  [PDF]
Elena Fabiola Ruiz Ledesma
Creative Education (CE) , 2010, DOI: 10.4236/ce.2010.12017
Abstract: This article describes the design and general outcome of applying a computer system that includes interactive activities to the topics of ratio and proportion. The work was undertaken with Mexican students attending primary school grade six (11 year olds). In designing the activities, our work was based on the studies of researchers who have focused on such topics, as well as on the work of researchers in the field of computer sciences and education technology. Support of the activities designed is found in psycho-pedagogy, in knowledge of mathematics and in the fields of computer sciences and education technology.
Representation Registers in the Solution of Calculus Problems  [PDF]
Elena Fabiola Ruiz Ledesma
Creative Education (CE) , 2011, DOI: 10.4236/ce.2011.23036
Abstract: This article is derived from the research project registered under number 20110343 (Ruiz, 2011), and developed in Escuela Superior de Cómputo del Instituto Politécnico Nacional (IPN) (School of Computer Sciences of the National Poly-technical Institute of Mexico). The article reports on the problems found among Engineering students with respect to their resistance to using different representation registers when solving optimization problems in the Calculus Learning Unit. Use of such registers could help the students to build mathematics know ledge and to solve calculus problems. As a didactic strategy, simulations are used in an electronic environment in order to support the students by fostering their use of tabular, graphical and algebraic representation registers. Interviews are undertaken of six of the professors who give the calculus courses, and a diagnostic questionnaire is applied to 68 students prior to and after working with the proposal. As for the theoretical framework, the work reported by Duval and Hitt is salient in this report, particularly their emphasis of the fact that working on activities by way of one single representation system is not sufficient. From the first responses provided by the students, one can conclude that the algebraic register is preferred by the majority of students. It is however used in a mechanical fashion without affording any meaning to the content of the problem and to the process of solving it. Another conclusion reported is that implementing tasks in the classroom in which the mathematics activity requires coherent use of different representations is necessary.
Primary and Secondary Teachers’ Knowledge, Interpretation, and Approaches to Students Errors about Ratio and Proportion Topics  [PDF]
Elena Fabiola Ruiz Ledesma
Creative Education (CE) , 2011, DOI: 10.4236/ce.2011.23035
Abstract: This study investigated elementary and secondary teachers’ understanding and pedagogical strategies applied to students making errors in finding a missing length in similar rectangles. It was revealed that secondary teachers had better understanding of ratio and proportion in similar rectangles than elementary teachers. While all secondary teachers solved the similar rectangles problems correctly, a large portion of elementary teacher struggled with the problem. In explaining their solution strategies, and even though similar strategies appeared both from elementary teachers and secondary teachers, a majority of secondary teachers pointed out the underlying idea of similarity, whereas less than half of the elementary teachers explained their reasoning for using ratios and proportion. This article is derived from the research project registered under number 20110343 (Ruiz, 2011), and developed in Escuela Superior de Cómputo del Instituto Politécnico Nacional (IPN) (School of Computer Sciences of the National Poly-technical Institute of Mexico)
A Cognitive Analysis When the Students Solve Problems  [PDF]
Elena Fabiola Ruiz Ledesma
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.34063
Abstract: The research reported in this paper shows an analysis of the cognitive process of students from the senior technical program on food technology, whom are asked to solve a contextualized event on systems of linear algebraic equations within the context of balance of matter in situations of chemical mixtures. The cognitive analysis is founded on the theories of Conceptual Fields and vents. For the analysis attention is focused on the representations carried out by students regarding the invariants in the schemes that they build when they face an event of contextualized mathematics. During the acting process of students emerge different types of representation which are appropriate to the context in which the research develops, with which a proposal for the classification of them.
Objeciones de Sen frente al enfoque de los bienes primarios de Rawls
Vethencourt,Fabiola;
EPISTEME , 2009,
Abstract: this article studies the objections raised by amartya sen against john rawls? view on primary goods, as well as the corresponding responses of the latter. it is sought to assess whether there is an irreconcilable position between both authors when referring to specific and fundamental matters of justice. through an interpretation of the arguments held by both authors, we found out that there is reconciliation between them after all. in fact, the horizon of analysis posed by sen represents a fundamental contribution to rawls? view on primary goods.
La distribución espacial del taller de dise?o y los códigos de conocimiento educativos dos casos de estudio: el taller de planta ‘tabicada’ y el taller de planta ‘abierta’
Vivas,Fabiola;
Educere , 2006,
Abstract: the main aim of this exploratory-descriptive research was to complete the space evaluation of an innovative educative space (design project units: dpu) in the architecture major in the university of táchira. the specific research objectives were: verify the premises of unet ’s architectural project, regarding the design of the dpu, describe the spatial behaviour of the main users in two types of building distribution of the dpu and explore how the physical space is related to teacher training in the projects course. the qualitative approach was used, within the framework of bernstein ’s (1973) pedagogical transmission theory and peatross and peponis’ interpretations (1995). according to bernstein, education space is a medium for social control. the knowledge code in education, understood as the principles that underlie the curriculum, pedagogy and evaluation, can take one of two shapes: integration and collection. the results show that the spatial distribution of the workshop not only reflected the pedagogical principles, but it also generated its own pedagogical efects.
PROTECCIóN JURíDICA DE LOS ADULTOS MAYORES EN CHILE
Lathrop,Fabiola;
Revista chilena de derecho , 2009, DOI: 10.4067/S0718-34372009000100005
Abstract: abstract: this article reviews the legal situation of older adults in chile and analyses a type of age discrimination: the mistreatment against older people; specially, the situation in nursing homes and long-term care institutions. describes the concept, types and risk factors of the abuse against older adults, and proposes some legal solutions that have been introduced in several countries to protect them. finally, this article draws some conclusions to contribute to the incipient chilean debate regarding protection older people.
Exclus?o social: no??o ou conceito?
Zioni, Fabiola;
Saúde e Sociedade , 2006, DOI: 10.1590/S0104-12902006000300003
Abstract: this manuscript contains a reflexion on the methodological status of the theme social exclusion based on a literature review of the scientific french and brazilian production of the last ten years, also taking into account the scientific recognition of the authors. the works of present day sociologists face great difficulties to define social exclusion due to the lack of global analysis on social cohesion. the lack of this conceptual definition implies in the lack of knowledge of philosophical and political paradigms behind the different concepts (republican, social-democrat and liberal) as well as of the different meanings that can be given to social exclusion. for this reason an identification of different paradigms of social sciences and of different orientations regarding social integration was undertaken. in brazilian production also there are controversies related to the theme social exclusion that most times are related to a structural inequality. about the scientific status of the concept, it can be classified as a methodological one, as it aggregates elements of knowledge used as images to explain reality that contributed largely for the inclusion of the theme of poverty in public spaces and for the implementation of public policies.
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