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Search Results: 1 - 10 of 329867 matches for " Pires Viviane S. "
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Saponins and Sapogenins from Brachiaria decumbens Stapf
Pires, Viviane S.;Taketa, Alexandre T. C.;Gosmann, Grace;Schenkel, Eloir P.;
Journal of the Brazilian Chemical Society , 2002, DOI: 10.1590/S0103-50532002000200002
Abstract: four steroidal saponins and three sapogenins were identified from aerial parts of brachiaria decumbens. their structures were established by chemical and spectroscopic means (1h and 13c nmr, hmbc, hmqc) as 3b-methoxy-lanost-9(11)-ene (1), diosgenin (2a), yamogenin (2b), 3-o-b-d-glucopyranosyl-24(s)-ethyl-22e -dihydrocholesterol (3a), 3-o-b-d-glucopyranosyl-24(r)-ethyl-22e -dihydrocholesterol (3b), dioscin (4a) and 3-o-{a-l-rhamnopyranosyl-(1?4)-[a-l-rhamnopyranosyl-(1 ?2)]-b-d-glucopyranosyl}-25(s)-spirost-5-en-3 b-ol (4b). all these compounds were isolated for the first time from b. decumbens and compound 4b is described for the first time as far as we know.
The role of Cerradomys Subflavus (Rodentia, Cricetidae) as seed predator and disperser of the palm Allagoptera arenaria
Grenha,Viviane; Macedo,Margarete V.; Pires,Alexandra S.; Monteiro,Ricardo F.;
Mastozoolog?-a neotropical , 2010,
Abstract: small rodents are among the most abundant vertebrate seed predators in the tropics and palm fruits are a rich source of energy for them. allagoptera arenaria is a nurse plant species at restinga vegetation in southeastern brazil. forty-five adult a. arenaria were marked to estimate fruit crop size and seed predation by rodents. two trapping sessions were carried out to identify the rodent seed predators. in addition, a fruit removal experiment was conducted to investigate the role of rodents as seed dispersers. of the 7409 seeds collected, 24% were damaged by rodents. predation rates ranged from 0 to 64% per plant and the number and the proportion of damaged seeds increased significantly with crop size. in the removal experiments, 64% of the fruits were manipulated by rodents either in situ or away from palms: 16% were preyed in the same place, 29% were preyed following removal, 2% were dispersed and 12% were buried. seed fate could not be identified for 5% of the seeds. cerradomys subflavus was the only species caught and this fact together with its abundance in the study area and tooth marks left in the endocarps indicates that this rodent is the main seed predator of this palm. considering this, c. subflavus should play a key role in a. arenaria population dynamics through the reduction of the total number of seeds that may be recruited. however, seed burial in sites favorable for germination suggests that this rodent can act also as seed disperser of this palm.
THE ROLE OF Cerradomys subflavus (RODENTIA, CRICETIDAE) AS SEED PREDATOR AND DISPERSER OF THE PALM Allagoptera arenaria
Viviane Grenha,Margarete V. Macedo,Alexandra S. Pires,Ricardo F. Monteiro
Mastozoolog?-a neotropical , 2010,
Abstract: Algunos peque os roedores están entre los vertebrados depredadores de semillas más abundantes en los trópicos y las semillas de palmas son una rica fuente de energía para ellos. Allagoptera arenaria es una planta facilitadora de la vegetación en restingas en el sudeste de Brasil. Cuarenta y cinco palmas adultas de A. arenaria fueron marcadas para estimar la producción de frutos y la depredación de semillas por roedores. Dos sesiones de trampeo fueron conducidas para identificar los roedores depredadores de semillas. Adicionalmente, un experimento de remoción de frutos fue conducido para investigar el papel de los roedores como dispersores de semillas. De las 7409 semillas colectadas el 24% fue da ada por roedores. Las tasas de depredación variaron de 0 a 99% por planta y el número y proporción de semillas da adas aumentó significativamente con la producción de frutos. En los experimentos de remoción, 64% de los frutos fueron manipulados por roedores in situ o distante de las plantas madres: 16% fueron depredadas in situ, 29% fueron depredadas después de removidas, 2% fueron dispersadas y 12% fueron enterradas. El destino de las semillas no pudo ser identificado para 5% de las semillas. Cerradomys subflavus fue la única especiecapturada y este hecho, junto con su abundancia en la área de estudio y las marcas de alimentación dejadas en los endocarpios, indican que sería el principal depredador de semillas en esta palma. C. subflavus puede estar desempe ando un papel clave en la dinámica poblacional de A. arenaria por la reducción del total de semillas que pueden ser reclutadas. Además, el enterramiento de las mismas en situaciones favorables para germinación indica que este roedor puede también actuar como dispersor.
Saponins and Sapogenins from Brachiaria decumbens Stapf
Pires Viviane S.,Taketa Alexandre T. C.,Gosmann Grace,Schenkel Eloir P.
Journal of the Brazilian Chemical Society , 2002,
Abstract: Four steroidal saponins and three sapogenins were identified from aerial parts of Brachiaria decumbens. Their structures were established by chemical and spectroscopic means (1H and 13C NMR, HMBC, HMQC) as 3beta-methoxy-lanost-9(11)-ene (1), diosgenin (2a), yamogenin (2b), 3-O-beta-D-glucopyranosyl-24(S)-ethyl-22E -dihydrocholesterol (3a), 3-O-beta-D-glucopyranosyl-24(R)-ethyl-22E -dihydrocholesterol (3b), dioscin (4a) and 3-O-{alpha-L-rhamnopyranosyl-(1->4)-[alpha-L-rhamnopyranosyl-(1 ->2)]-beta-D-glucopyranosyl}-25(S)-spirost-5-en-3 beta-ol (4b). All these compounds were isolated for the first time from B. decumbens and compound 4b is described for the first time as far as we know.
Triterpenes and new saponins from Ilex chamaedryfolia: chemotaxonomic tool to ilex species differentiation
Lencina, Claiton L.;Cardoso, Mariana C. de;Zancanaro, Ivomar;Gosmann, Grace;Pires, Viviane S.;Sonnet, Pascal;Guillaume, Dominique;Schenkel, Eloir P.;
Química Nova , 2011, DOI: 10.1590/S0100-40422011000200010
Abstract: three saponins were isolated from leaves of ilex chamaedryfolia. their structures were established by spectroscopic and mass spectrometry data as the new saponin 3β-o-β-d-glucopyranosyl-(1-3)-α-l-arabinopyranosyl-20( s)-19α-hydroxyurs-12-en-28-oic acid 28-o-β-d-glucopyranosyl-(1-3)-β-d-glucopyranosyl ester, the new saponin 3β-o-β-d-glucopyranosyl-(1-3)-α-l-arabinopyranosyl-20( s)-19α-hydroxyurs-12-en-28-oic acid 28-o-β-d-glucopyranosyl ester and the known saponin 3β-o-β-d-glucuronopyranosyl-20(r )-19α-hydroxyurs-12-en-28-oic acid 28-o-β-d-glucopyranosyl ester. ursolic acid and α-amyrin were also isolated.
"Eis Quem Surge no Estádio: é Atalante!" A História das Mulheres nos Jogos Gregos
Paula Viviane Chiés
Movimento , 2006,
Abstract: El estudio buscó indicaciones de la participación femenina en los juegos griegos, entre ellos, los Juegos Olímpicos. Analizando la participación de las mujeres en estos acontecimientos, el texto aborda las justificaciones que determinaron la prohibición, o iguales, la limitación de este grupo en ser parte de actividades del mundo masculino en la civilización griega. A contextualizar estas justificaciones, el estudio también destaca las características principales de cada fase educativa, distinguiendo la educación llevado a través en Esparta, en el cual las mujeres possuiam un espacio más grande para la práctica de ejercicios y en Atenas, en que la educación femenina lo restringió el carácter doméstico, no teniendo la preocupación con la preparación física de las madres para jugar sus tareas del hogar, o igual, de generar a ni os robustos y sanos.
Ads/CFT correspondence in condensed matter
A S T Pires
Physics , 2010,
Abstract: The goal of these notes is to introduce, in a very elementary way, the idea of the anti de-Sitter/Conformal Field Theory (AdS/CFT) correspondence to condensed matter physicists. This theory relates a gravity theory in a (d+1)- dimensional anti-de Sitter spacetime to a strongly-coupled d- dimensional quantum field theory living on its boundary. The AdS/CFT correspondence can be used to study finite temperature real time processes, such as response functions and dynamics far from equilibrium in quantum critical points in condensed matter systems. Computation of these quantities is reduced to solving classical gravitational equations in one higher dimension than the original theory.
Weak Lensing Mass Reconstruction: Flexion vs Shear
S. Pires,A. Amara
Physics , 2010, DOI: 10.1088/0004-637X/723/2/1507
Abstract: Weak gravitational lensing has proven to be a powerful tool to map directly the distribution of dark matter in the Universe. The technique, currently used, relies on the accurate measurement of the gravitational shear that corresponds to the first-order distortion of the background galaxy images. More recently, a new technique has been introduced that relies on the accurate measurement of the gravitational flexion that corresponds to the second-order distortion of the background galaxy images. This technique should probe structures on smaller scales than that of a shear analysis. The goal of this paper is to compare the ability of shear and flexion to reconstruct the dark matter distribution by taking into account the dispersion in shear and flexion measurements. Our results show that the flexion is less sensitive than shear for constructing the convergence maps on scales that are physically feasible for mapping, meaning that flexion alone not be used to do convergence map reconstruction, even on small scales.
Burnout en personal de enfermería de la Unidad de Cuidados Intensivos Pediátricos
Jofré A,Viviane; Valenzuela S,Sandra;
Aquichán , 2005,
Abstract: the burnout syndrome (bs) is used to refer to institutional working stress generated in professions which maintain a constant and direct relation with people, as the case of nursing; it has three dimensions: emotional fatigue, depersonalization and personal realization. the objective of this work was to determine the prevalence of bs in nursing staff in pediatric intensive care unit (picu) at guillermo grant benavente de concepción, chile hospital, and the factors related with it. in this descriptive exploratory study a questionnaire of socio demographic data and the inventory of burnout of maslach were applied to a sample during three months. for the analysis of data a descriptive statistics and non parametric tests for category variables were used. the scores obtained in the dimensions of bs on nursing staff at picu showed higher percentajes of low burnout levels; more than half the population in the study had high personal achievements. knowledge of variables related with burnout will allow the design of preventive strategies and the treatment to improve the health and the quality of assistance in the work area.
O texto híbrido de Anzaldúa e a re-escrita de Hinojosa: contribui es para uma reflex o sobre uma tradu o dos atravesados
Thaís Ribeiro Bueno,Viviane Veras
Tradu??o & Comunica??o : Revista Brasileira de Tradutores , 2011,
Abstract: De que formas a tradu o pode ser relacionada ao processo de choque de culturas e à emergência do hibridismo linguístico presente em regi es de fronteira – mais especificamente, no contexto da cultura chicana que tem se desenvolvido de maneira política e socialmente conflituosa na regi o da fronteira entre México e Estados Unidos? Com base em conceitos formulados por autores das linhas pósestruturalista (a diffèrance de Jacques Derrida, e a tradu o ética de Antoine Berman) e pós-colonialista (o sujeito híbrido em Homi Bhabha e a tradu o como resistência proposta por Tejaswini Niranjana), busca-se avaliar em que medida a tradu o pode assumir papéis relevantes na constante reformula o das identidades dos sujeitos emergentes nos entre-lugares e em discursos fronteiri os. A análise terá como foco a linguagem híbrida presente em duas obras representativas da literatura chicana: Borderlands/La Frontera – The New Mestiza, escrita por Gloria Anzaldúa e publicada em 1987, e Mi Querido Rafa, de autoria do chicano Rolando Hinojosa, escrito em 1981. A partir de reflex es sobre as (im)possibilidades de tradu o que a obra de Anzaldúa oferece e a experiência de autotradu o de Rolando Hinojosa, é possível considerar a fronteira um lugar privilegiado para pensar as constantes reformula es e negocia es (quase sempre social e politicamente violentas) e pensar o ato tradutório como uma rede complexa de opera es, na qual est o em jogo quest es políticas, poder e subjetividades.
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