oalib

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2208 )

( 2024 )

( 2023 )

( 2022 )

自定义范围…

匹配条件： “Margarita Do Campo” ，找到相关结果约18923条。
列表显示的所有文章，均可免费获取
第1页/共18923条
每页显示 条
Low-grade metamorphism of Cambro-Ordovician successions in the Famatina belt, Southern-Central Andes: Burial-inversion history linked to the evolution of the proto-Andean Gondwana margin
Collo,Gilda; Do Campo,Margarita; Nieto,Fernando;
Andean geology , 2011,
Abstract: the metamorphic p-t conditions of low-grade units from the famatina belt, central andes of argentina, were estimated through petrography, x-ray diffraction, and electron microscopy. for the middle-upper cambrian negro peinado formation a tectono-metamorphic event associated with intense intrafoliar folding, with estimated temperatures between 290 and 400°c (kicis: 0.16-0.27a°29, biotite blastesis and compositional homogeneity in dioctahedral micas) and intermediate pressure conditions (white mica b parameter: 9.010á-9.035á), was recognized. the achavil formation (middle-upper cambrian) presents a main metamorphic event associated with temperatures between 200 and 290°c (kicis: 0.26-0.41a°29) and intermediate- to low-pressure conditions (white mica b parameter values: 8.972á-9.017á). some illitic substitution in dioctahedral micas also indicates lower metamorphic grade than the negro peinado formation. for upper cambrian to middle ordovician sequences a burial metamorphic pattern, with a progressive decrease in metamorphic grade from volcancito formation to cerro morado group (ca. 490-465 ma; kicis: 0.31-0.69a°29) and absence of tendency changes linked to strati-graphic discontinuities was proposed. mica and chlorite are the main phyllosilicates in the oldest units, while ilt/ sme (r3) mixed-layer is almost the only one in the youngest. white mica b parameter indicates intermediate- to low-pressure conditions for all these sequences. this burial metamorphic pattern presents a marked break as the youngest ordovician unit (la aguadita formation, after ca. 452 ma) records higher metamorphic conditions (ikcis: 0.28-0.19a°29) than units from the ordovician arc, with estimated temperatures between 270 and 330°c and intermediate-pressure conditions. our results indicate that basin contraction and inversion processes related to the ordovician ocloyic orogeny involved at least two well-discriminated and not superposed metamorphic episodes in this region.
Low-grade metamorphism of Cambro-Ordovician successions in the Famatina belt, Southern-Central Andes: Burial-inversion history linked to the evolution of the proto-Andean Gondwana margin Metamorfismo de bajo grado de sucesiones cambro-ordovícicas en el cinturón del Famatina, Andes Centrales de Argentina: Historia de enterramiento-exhumación ligada a la evolución del margen proto-andino de Gondwana
Gilda Collo,Margarita Do Campo,Fernando Nieto
Andean Geology , 2011,
Abstract: The metamorphic P-T conditions of low-grade units from the Famatina belt, Central Andes of Argentina, were estimated through petrography, X-ray diffraction, and electron microscopy. For the Middle-Upper Cambrian Negro Peinado Formation a tectono-metamorphic event associated with intense intrafoliar folding, with estimated temperatures between 290 and 400°C (KIcis: 0.16-0.27A°29, biotite blastesis and compositional homogeneity in dioctahedral micas) and intermediate pressure conditions (white mica b parameter: 9.010á-9.035á), was recognized. The Achavil Formation (Middle-Upper Cambrian) presents a main metamorphic event associated with temperatures between 200 and 290°C (KIcis: 0.26-0.41A°29) and intermediate- to low-pressure conditions (white mica b parameter values: 8.972á-9.017á). Some illitic substitution in dioctahedral micas also indicates lower metamorphic grade than the Negro Peinado Formation. For Upper Cambrian to Middle Ordovician sequences a burial metamorphic pattern, with a progressive decrease in metamorphic grade from Volcancito Formation to Cerro Morado Group (ca. 490-465 Ma; KIcis: 0.31-0.69A°29) and absence of tendency changes linked to strati-graphic discontinuities was proposed. Mica and chlorite are the main phyllosilicates in the oldest units, while Ilt/ Sme (R3) mixed-layer is almost the only one in the youngest. White mica b parameter indicates intermediate- to low-pressure conditions for all these sequences. This burial metamorphic pattern presents a marked break as the youngest Ordovician unit (La Aguadita Formation, after ca. 452 Ma) records higher metamorphic conditions (IKcis: 0.28-0.19A°29) than units from the Ordovician arc, with estimated temperatures between 270 and 330°C and intermediate-pressure conditions. Our results indicate that basin contraction and inversion processes related to the Ordovician Ocloyic Orogeny involved at least two well-discriminated and not superposed metamorphic episodes in this region. Las condiciones P-T del metamorfismo de las unidades de bajo grado del cinturón del Famatina, Andes Centrales de Argentina, fueron estimadas mediante petrografía, difracción de rayos-X y microscopía electrónica. La Formación Negro Peinado (Cámbrico Medio-Superior) fue afectada por un evento tectono-metamórfico asociado con un plegamiento intrafoliar intenso, para el cual se estimaron temperaturas entre 290 y 400°C (IKcis: 0,16-0,27 A°29, blástesis de biotita y homogeneidad composicional en micas dioctaédricas) y presiones intermedias (parámetro b de la mica blanca: 9,010 á y 9,035 á). La Formación Achavil (Cámbric
Edades de metamorfismo en las unidades con bajo grado de la región central del Famatina: la impronta del ciclo orogénico oclóyico (Ordovícico)
Collo,Gilda; Astini,Ricardo A; Cardona,Agustín; Do Campo,Margarita D; Cordani,Umberto;
Revista geológica de Chile , 2008, DOI: 10.4067/S0716-02082008000200001
Abstract: many of the metamorphic and deformational events associated to low-grade units in nw argentina have been linked with ancient orogenies, like the pampean (cambrian) and the ocloyic (ordovician) cycles. the lack of specific ages in the low-grade metamorphic rocks of the famatina belt, as well as the absence of a detailed stratigraphic analysis, have led to ambiguous interpretations respect to the paleozoic evolution of the southern segment of the central andes. recent work allows recognition of two units within the low-grade 'metamorphic basement'; the negro peinado and the achavil formations. provenance analysis relates deposition of both units to the final stages of the pampean cycle during the cambrian, whereas an ordovician (ocloyic) synorogenic nature is suggested for the la aguadita formation, also traditionally included within the low-grade 'metamorphic basement'. thus, as a whole, these units areyounger than the traditionally correlated pre-pampean punco vise ana formation. k-ar ages obtained forfamatina indicate that low-grade metamorphism and deformation of these units are ordovician, in contrast to a much older age (proterozoic-middle cambrian) previously suggested. ages of 457±9 ma (whole rock) and 463±14 ma (<2μm fraction) for the negro peinado formation allow establishing a link with the climax of the ocloyic orogeny developed along western gondwana during the early paleozoic. ages of 435±12 ma (<2μm fraction) in the la aguadita formation and of 444±8 ma (whole rock) in phyllonites of the ángulos shear zone are consistent with an extent into the earliest silurian for this cycle. additionally, a 359±7 ma (<2μm fraction) age for the negro peinado formation (las trancas shear zone) indicates local resetting within the age range assigned to the achalian orogeny (late silurian-early carboniferous).
Edades de metamorfismo en las unidades con bajo grado de la región central del Famatina: la impronta del ciclo orogénico oclóyico (Ordovícico) Metamorphic ages of low-grade units in the central region of Famatina: The signature of the Ocloyic Orogeny (Ordovician)
Gilda Collo,Ricardo A Astini,Agustín Cardona,Margarita D Do Campo
Revista geológica de Chile , 2008,
Abstract: Muchos de los episodios de metamorfismo y deformación asociados a las rocas de bajo grado del NO argentino fueron tradicionalmente vinculados con orógenos antiguos como el pampeano (Cámbrico) y el oclóyico (Ordovícico). En el cinturón del Famatina, la falta de dataciones precisas y de un análisis estratigráfico de detalle en las sucesiones con bajo grado, condujeron a interpretaciones ambiguas respecto a la evolución paleozoica del segmento sur de los Andes Centrales. Estudios recientes establecen que el 'basamento metamórfico' de bajo grado de dicha región estaría conformado por las formaciones Negro Peinado y Achavil, cuyos análisis de procedencia las vinculan con la finalización del ciclo pampeano. Por su parte, la Formación La Aguadita, también afectada por metamorfismo de bajo grado, correspondería a depósitos sinorogénicos ordo vicíeos (oclóyieos). En consecuencia, el conjunto sería más joven que la FormaciónPunco viscana (prepampeana) con la que fue habitualmente correlacionado. Las edades K-Ar presentadas en este trabajo permiten establecer que el metamorfismo y la deformación de estas unidades son Ordovícicos y no más antiguos (Proterozoico-Cámbrico Medio) como se interpretó durante muchos a os. Edades de 457±9 Ma (roca total) y 463±14 Ma (fracción <2μm) obtenidas para la Formación Negro Peinado, permiten su vinculación con el climax de la orogenia oclóyiea, desarrollada en el margen occidental de Gondwana durante el Paleozoico inferior. Las edades de 435±12 Ma (fracción <2μm) en la Formación La Aguadita y de 444±8 Ma (roca total) en filonitas de la faja de deformación ángulos, son consistentes con la extensión de este ciclo orogénico hasta el Silúrico Inferior. Adicionalmente, se obtuvo una edad de 359±7 Ma (fracción <2μm) en rocas de la Formación Negro Peinado (faja de deformación Las Trancas), que evidencia un reequilibrio local del sistema isotópico K-Ar parcialmente coincidente con el rango temporal asignado para la orogenia achaliana (Silúrico Tardío-Carbonífero temprano). Many of the metamorphic and deformational events associated to low-grade units in NW Argentina have been linked with ancient orogenies, like the Pampean (Cambrian) and the Ocloyic (Ordovician) cycles. The lack of specific ages in the low-grade metamorphic rocks of the Famatina belt, as well as the absence of a detailed stratigraphic analysis, have led to ambiguous interpretations respect to the Paleozoic evolution of the southern segment of the Central Andes. Recent work allows recognition of two units within the low-grade 'metamorphic basement'; the Negro Peinado and th
La cultura de lo cotidiano. Estudio sociocultural de la ciudad de Lugo, de Carmen Lamela Viera
Manuel García Do Campo
Política y Sociedad , 1999, DOI: -
Abstract: Sin resumen
VALIDEZ Y CONFIABILIDAD DE LA ESCALA BREVE DE FRANCIS PARA ACTITUD ANTE EL CRISTIANISMO Validity and reliability of the five-item version of the Francis scale of attitude toward Christianity
Zuleima Cogollo,Edna Margarita Gómez-Bustamante,Edwin Herazo,Adalberto Campo-Arias
Revista Facultad de Medicina de la Universidad Nacional de Colombia , 2012,
Abstract: Antecedentes. La escala breve de Francis para actitud ante el cristianismo (Francis-5) muestra alta consistencia interna y confiabilidad de tipo prueba-reprueba en adolescentes colombianos. Sin embargo, las investigaciones sólo están disponibles en inglés y no se conoce la validez nomológica de escala en esta población. Objetivo. Corroborar la validez y confiabilidad de la escala Francis-5 en adolescentes estudiantes de Cartagena, Colombia. Material y métodos. Participaron 1.730 estudiantes de sexto a undécimo grado, con una media para la edad de 14,7 a os (DE=1,2), y 52,7% mujeres. Se estimó la validez de constructo (análisis de factores) y la validez nomológica (comparación de las puntuaciones entre mujeres y varones). Para conocer la confiabilidad se calcularon los coeficientes alfa de Cronbach y omega de McDonald. Resultados. La escala Francis-5 mostró una estructura unidimensional, con un valor propio de 3,681 que dio cuenta del 73,6% de la varianza. Las mujeres puntuaron significativamente mayor que los varones, 18,5 (DE=2,7) vs. 17,9 (DE=3,3) (t = 4,3; p<0,001). El coeficiente alfa fue 0,909 y; el omega, 0,910. Conclusiones. La Francis-5 es una escala válida y confiable en estudiantes adolescentes de Cartagena, Colombia. Se necesita conocer el desempe o de esta escala en otras regiones colombianas. Background. The short version of Francis Scale attitude toward Christianity (Francis-5) presents high internal consistency and test-retest reliability among Colombian adolescents. However, the papers are only available in English, and nomological validity is not known in this population. Objective. To corroborate the validity and reliability of the Francis-5 scale among adolescent students at Cartagena, Colombia. Materials and method. A total of 1,730 sixth to eleventh grade students, mean age of 14,7 years old (SD=1.2), and 52.7% were girls. Construct validity (factor analysis) and nomological validity (score comparison between boys and girls) were explored. Cronbach alpha and McDonald omega were computed as measures of reliability. Results. Francis-5 Scale showed one dimensional structure, with Eigen value of 3.681 that accounted for 73.6% of the total variance. Girls scored significantly higher than boys, 18.5 (SD=2.7) versus 17.9 (SD=3.3) (t=4,3; p<0.001). Coefficient alpha was 0.909; and coefficient omega, 0.910. Conclusions. Francis-5 is a valid and reliable scale among adolescent students at Cartagena, Colombia. It is needed to investigate its psychometric performance in others Colombian population.
Factores de riesgo para la transmisión de leishmaniasis cutánea en ni？os de 0 a 5 a？os en un área endémica de Leishmania (Viannia) braziliensis
Ampuero, Julia;Urdaneta, Margarita;Macêdo, Vanize de Oliveira;
Cadernos de Saúde Pública , 2005, DOI: 10.1590/S0102-311X2005000100018
Abstract: with the purpose of identifying risk factors for cutaneous leishmaniasis transmission in children from 0 to 5 years, a matched case-control study was carried out in corte de pedra, bahia, brazil, an endemic area of leishmania (viannia) braziliensis. children with a positive leishmanin skin test and one or more active lesions or scars consistent with cutaneous leishmaniasis were defined as cases. forty cases and 71 controls were selected and matched by age and place of residence. the presence of a family member with a history of cutaneous leishmaniasis in the year prior to the appearance of the disease in the child was found to be an important risk factor (m？rmh = 17.75; 95%ci: 4.08-77.25). no evidence of association between the disease and other risk factors was found, such as child's habits inside or outside the house, domiciliary or peridomiciliary characteristics, or presence of vectors or probable reservoir animals. these findings support the hypothesis that humans serve as both the reservoir and source of infection for this age group.
Contribuciones y complicaciones de michel maffesoli en el estudio de las neocomunidades estudiantiles postmodernas
Torres Morillo,Moraima; Dorneles,Malvina do Amaral; Villegas,Ma. Margarita;
Paradígma , 2008,
Abstract: a this paper it`s discuss implications of the theoretical contributions of michel maffesoli (1998; 2003; 2005a; 2005b; 2005c) in the field of the educational research. this writher invites social scientists to contemplate the social breathing of present civilization, in which progress myths, futurist projects and great utopical ideals have fallen. within this reality, a greater amount of young people have become every day irreverent in front of educational demands. they seems to focus their future expectations in their own personal conquests, strongly marked by a culture of present that favors pleasure here and now, as opposed to work, endurance and postponement. these youngsters integrate students post modern neo-communities where it is common to find school dropouts and all sort of failures and socially excluded people. these neo-communities are growing steadily, inviting us to study the situation from a sensitive logic (maffesoly, 1998) as opposed to the rational tradition used in modern science.
Factores de riesgo para la transmisión de leishmaniasis cutánea en ni os de 0 a 5 a os en un área endémica de Leishmania (Viannia) braziliensis
Ampuero Julia,Urdaneta Margarita,Macêdo Vanize de Oliveira
Cadernos de Saúde Pública , 2005,
Abstract: Fue realizado un estudio caso-control pareado en Corte de Pedra, Bahía, Brasil, área endémica de Leishmania (Viannia) braziliensis para evaluar los diferentes factores de riesgo asociados a la presencia de leishmaniasis cutánea en ni os de 0 a 5 a os. Fueron considerados como casos, los ni os con prueba de leishmanina positiva y que presentaban en el examen físico, una o más lesiones clínicas, activas o cicatrizales, compatibles con leishmaniasis cutánea. Fueron seleccionados 40 casos y 71 controles que fueron pareados por edad y área de residencia. La presencia de algún otro miembro de la familia con antecedente de leishmaniasis cutánea durante el a o anterior a la aparición de la enfermedad en el ni o demostró ser un importante factor de riesgo (M R MH = 17,75; IC95%: 4,08-77,25). No se encontraron evidencias de asociación con otros factores, como hábitos del ni o dentro y fuera de casa, características de la vivienda y del peridomicilio, presencia de vectores y animales como probables reservorios. Estos hallazgos apoyan la hipótesis que el ser humano podría comportarse como un posible reservorio y servir de fuente de contagio para este grupo de edad.
MOG antibodies in combined central and peripheral demyelination syndromes
Alana Stephens,Devon I. Rubin,I. Vanessa Marin Collazo,Rocio Vazquez Do Campo
- , 2018, DOI: 10.1212/NXI.0000000000000503
Abstract:
第1页/共18923条
每页显示 条


Home
Copyright © 2008-2020 Open Access Library. All rights reserved.