14,892 research outputs found

    The silicon stable isotope distribution along the GEOVIDE section (GEOTRACES GA-01) of the North Atlantic Ocean

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    The stable isotope composition of dissolved silicon in seawater (δ30SiDSi) was examined at 10 stations along the GEOVIDE section (GEOTRACES GA-01), spanning the North Atlantic Ocean (40–60∘ N) and Labrador Sea. Variations in δ30SiDSi below 500 m were closely tied to the distribution of water masses. Higher δ30SiDSi values are associated with intermediate and deep water masses of northern Atlantic or Arctic Ocean origin, whilst lower δ30SiDSi values are associated with DSi-rich waters sourced ultimately from the Southern Ocean. Correspondingly, the lowest δ30SiDSi values were observed in the deep and abyssal eastern North Atlantic, where dense southern-sourced waters dominate. The extent to which the spreading of water masses influences the δ30SiDSi distribution is marked clearly by Labrador Sea Water (LSW), whose high δ30SiDSi signature is visible not only within its region of formation within the Labrador and Irminger seas, but also throughout the mid-depth western and eastern North Atlantic Ocean. Both δ30SiDSi and hydrographic parameters document the circulation of LSW into the eastern North Atlantic, where it overlies southern-sourced Lower Deep Water. The GEOVIDE δ30SiDSi distribution thus provides a clear view of the direct interaction between subpolar/polar water masses of northern and southern origin, and allow examination of the extent to which these far-field signals influence the local δ30SiDSi distribution

    Predictors of walking capacity in peripheral arterial disease patients

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    OBJECTIVE: To estimate walking capacity in intermittent claudication patients through a prediction model based on clinical characteristics and the walking impairment questionnaire. METHODS: The sample included 133 intermittent claudication patients of both genders aged between 30 and 80 years. Data regarding clinical characteristics, the walking impairment questionnaire and treadmill walking test performance were obtained. Multiple regression modeling was conducted to predict claudication onset distance and total walking distance using clinical characteristics (age, height, mass, body mass index, ankle brachial index lower, gender, history of smoking and co-morbid conditions) and walking impairment questionnaire responses. Comparisons of claudication onset distance and total walking distance measured during treadmill tests and estimated by a regression equation were performed using paired t-tests. RESULTS: Co-morbid conditions (diabetes and coronary artery disease) and questions related to difficulty in walking short distances (walking indoors - such as around your house and walking 5 blocks) and at low speed (walking 1 block at average speed - usual pace) resulted in the development of new prediction models high significant for claudication onset distance and total walking distance (p0.05) were observed. CONCLUSION: The current study demonstrated that walking capacity can be adequately estimated based on co-morbid conditions and responses to the walking impairment questionnaire

    Dark Sector from Interacting Canonical and Non-Canonical Scalar Fields

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    In this work it is investigated general models with interactions between two canonical scalar fields and between one non-canonical (tachyon-type) and one canonical scalar field. The potentials and couplings to the gravity are selected through the Noether symmetry approach. These general models are employed to describe interactions between dark energy and dark matter, with the fields being constrained by the astronomical data. The cosmological solutions of some cases are compared with the observed evolution of the late Universe.Comment: 20 pages, 13 figures, correction of misprints in eqs. (4), (5), (43), (44

    Desarrollo infantil: análisis de un nuevo concepto

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    Objetivos: realizar el análisis del concepto "desarrollo infantil" y evaluarlo con expertos. Método: análisis de concepto según el modelo híbrido, en tres fases: fase teórica, con revisión de la literatura; fase de campo, con investigación cualitativa con los profesionales que atienden a niños; y fase analítica para articulación de datos de los pasos anteriores, basada en la teoría bioecológica del desarrollo, con la producción de una nueva definición para el concepto abordado. Esa definición fue evaluada por especialistas en un grupo de enfoque. El proyecto fue aprobado por un Comité de Ética en la Investigación. Resultados: la revisión de 256 artículos de 12 bases de datos y de libros, y entrevistas con 10 profesionales, mostró que: el desarrollo infantil tiene como antecedentes aspectos del embarazo, factores propios del niño, factores contextuales, destacando las relaciones y el cuidado de los niños, y aspectos sociales; sus consecuencias pueden ser positivas o negativas, impactando en la sociedad; sus atributos son comportamientos y habilidades del niño; sus definiciones valoran aspectos madurativos, contextuales o ambos. Nueve expertos validaron la nueva definición producida en el análisis del concepto, la que expresa la magnitud del fenómeno y los factores no presentados en otras definiciones. Conclusión: Se generó una nueva definición para las clasificaciones de enfermería y la atención integral a los niños.Objetivos: realizar análise de conceito do termo desenvolvimento infantil e submeter à análise por peritos. Método: análise de conceito segundo o modelo híbrido, em três fases: fase teórica, com revisão bibliográfica; fase de campo, de pesquisa qualitativa com profissionais que atendem crianças; e fase analítica, de articulação dos dados das etapas anteriores, baseada na teoria bioecológica do desenvolvimento, com produção de nova definição para o conceito. A nova definição foi validada por peritos em um grupo focal. Projeto aprovado pelo Comitê de Ética em Pesquisa. Resultados: a revisão de 256 artigos, de 12 bases de dados e livros, e entrevistas com 10 profissionais, mostrou que: o conceito desenvolvimento infantil tem como antecedentes aspectos da gestação, fatores próprios da criança, fatores do contexto, destacando as relações e o cuidado à criança, e aspectos sociais; suas consequências podem ser positivas ou negativas, impactando na sociedade; seus atributos são comportamentos e habilidades da criança; suas definições contêm perspectivas maturacionais, contextuais ou ambas. A nova definição, produzida na análise e validada por nove peritos, expressa a magnitude do fenômeno e fatores não apresentados em outras definições. Conclusão: a análise de conceito gerou uma definição para as classificações de enfermagem na atenção integral à criança.Objectives: to perform concept analysis of the term child development (CD) and submit it to review by experts. Method: analysis of concept according to the hybrid model, in three phases: theoretical phase, with literature review; field phase of qualitative research with professionals who care for children; and analytical phase, of articulation of data from previous steps, based on the bioecological theory of development. The new definition was analyzed by experts in a focus group. Project approved by the Research Ethics Committee. Results: we reviewed 256 articles, from 12 databases and books, and interviewed 10 professionals, identifying that: The CD concept has as antecedents aspects of pregnancy, factors of the child, factors of context, highlighting the relationships and child care, and social aspects; its consequences can be positive or negative, impacting on society; its attributes are behaviors and abilities of the child; its definitions are based on maturation, contextual perspectives or both. The new definition elaborated in concept analysis was validated by nine experts in focus group. It expresses the magnitude of the phenomenon and factors not presented in other definitions. Conclusion: the research produced a new definition of CD that can improve nursing classifications for the comprehensive care of the child

    Anatomia da artéria pudenda superficial externa: estudo quantitativo

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    The importance of the superficial external pudendal artery in cases of lower limb obstructive arteriopathies has been established, and a perfect knowledge of its anatomy is desirable for the creation of successful flaps involving it. However, little information is available on the morphometry of this artery. PURPOSE: In this study, we conducted a quantitative investigation of the superficial external pudendal artery as the basis for skin grafts. METHOD: Twenty-five right and left sides of the inguinal region of male cadavers were dissected. After retracting the skin at the inguinal region, the femoral vessels and the sapheno-femoral junction were exposed. The following aspects were then analyzed: 1) the presence of the superficial external pudendal artery, 2) the place of origin of the superficial external pudendal artery and the common trunk, 3) the duplication of the superficial external pudendal artery, 4) the distance from the superficial external pudendal artery or the common trunk to the inguinal ligament, and 5) the diameter of the superficial external pudendal artery. RESULTS: The results were the following: 1) superficial external pudendal arteries were found in 46 of 50 sides (92%); 2) they originated from the femoral artery in 45 cases and from the deep femoral artery in only 1 case; 3) the arteries were found duplicated in 21 cases (46%), as a common trunk in 11 cases (24%), and as a single artery in 14 cases (30%); 4) the distance from the superficial external pudendal artery to the inguinal ligament ranged from 0.8 cm to 8.5 cm; from the common trunk, it ranged from 3.5 cm to 6.7 cm; 5) the diameter of the superficial external pudendal artery ranged from 1.2 mm to 3.8 mm; and 6) the diameter of the common trunk ranged from 1.35 mm to 5.15 mm. CONCLUSION: The results show that the superficial external pudendal artery generally originates from the femoral artery. It was found as a common trunk, duplicated, or as a single artery. There was a great variability in both the diameter of the artery and the distance from the artery to the inguinal ligament. Most of the data showed no significant differences between the right and the left sides.A importância do conhecimento da anatomia da artéria pudenda superficial externa está bem estabelecida e um conhecimento adequado de sua anatomia é desejável para a criação bem sucedida de flaps. Entretanto, são escassos os trabalhos morfométricos sobre esta artéria. OBJETIVO. No presente estudo, foi feita uma análise quantitativa da artéria pudenda superficial externa, como base para enxertos de pele. MÉTODO. Foram dissecadas 25 regiões inguinais direitas e 25 esquerdas de cadáveres do sexo masculino. Após rebater a pele da região inguinal, os vasos femorais, a junção safeno-femoral e a artéria pudenda superficial externa foram expostas. Os seguintes aspectos foram então analisados: 1. Presença da artéria pudenda superficial externa; 2. Local de origem da artéria pudenda superficial externa ou do tronco comum; 3. Duplicação da artéria pudenda superficial externa; 4. Distância da artéria pudenda superficial externa ou do tronco comum ao ligamento inguinal; 5. Diâmetro da artéria pudenda superficial externa. RESULTADOS. Os resultados mostraram que: 1. A artéria pudenda superficial externa foi encontrada em 46 dos 50 lados dissecados (92%); 2. A artéria teve origem na artéria femoral em 45 casos; em um único caso teve origem na artéria femoral profunda; 3. A artéria foi encontrada duplicada, em 21 casos (46%), formando um tronco comum, que depois se bifurcava, em 11 casos (24%) e como uma artéria única 14 vezes (30%); 4. A distância da artéria ao ligamento inguinal variou de 0,8 cm a 8,5 cm; quando sob a forma de tronco comum, esta distância variou de 3,5 cm a 6,7 cm; 5. O diâmetro da artéria pudenda superficial externa variou de 1,36 mm a 5,15 mm. CONCLUSÕES. Os resultados mostram que a artéria pudenda superficial externa origina-se, na grande maioria dos casos, da artéria femoral. Foi encontrada como um tronco comum, duplicada ou como uma artéria única. O diâmetro da artéria mostrou grande variabilidade assim como a distância da artéria ao ligamento inguinal. A maioria dos dados não mostrou diferença significante entre os lados direito e esquerdo

    Spatial and temporal variability of soil CO2 flux in sugarcane green harvest systems

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    The sugarcane green harvest system, characterized by mechanized harvesting and the absence of crop burning, affects soil quality by increasing crop residue on the soil surface after harvest; thus, it contributes to improving the physical, chemical, and microbiological properties and influences the soil carbon content and CO2 flux (FCO2). This study aimed to evaluate the spatial and temporal variability of soil FCO2 in sugarcane green harvest systems. The experiment was conducted in two areas of sugarcane in São Paulo, Brazil: the first had a 5-year history of sugarcane green harvest (SG-5) and the second had a longer history of 10 years (SG-10). The temporal FCO2 were evaluated in the dry and rainy periods, and spatial variability in the dry period, and related to soil chemical and physical properties, including organic C porosity, bulk density, soil penetration resistance, mean weight diameter of soil aggregates, clay, P, S, Ca, Mg and Fe. The temporal variability indicated no differences between the dry and rainy periods in SG-10, while in SG-5 soil moisture was increased by 33 % in the rainy period. The spatial variability indicated a different pattern from the temporal one, where FCO2 in SG-10 was correlated with soil temperature, air-filled pore space, total porosity, soil moisture, and the Ca and Mg contents; in the SG-5 area, FCO2 was correlated with soil mean weight diameter of soil aggregates and the sulfur content.4

    Vigencia del cardenismo

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    La principal motivación del presente libro y que distingue a éste de otros trabajos sobre Lázaro Cárdenas es mostrar porqué, estimulado por el marasmo que tan graves consecuencias ha tenido para las mayorías y para la nación, agravadas aún más por las políticas económicas y sociales "neoliberales" puestas en práctica en México durante los últimos años, las aguas de la profunda y caudalosa corriente política del cardenismo que muchos consideraban agotada encontraron un nuevo vigoroso cauce político e ideológico en el movimiento popular que emergió en 1988, en el curso del proceso electoral de ese año. Esa ideología popular, de gran importancia potencial para las luchas presentes y futuras del pueblo trabajador mexicano, se inspira en la trayectoria revolucionaria de Cárdenas, un político excepcional -desde antes, durante y después de que ocupara una profunda huella y un pensamiento congruente, expresado en su vasta obra escrita. Muestran los autores que los ingredientes principales de esta ideología revolucionaria son el patriotismo, el nacionalismo, la permanente solidaridad con los pueblos por el imperialismo norteamericano, en primer lugar los de nuestra América, así como la profunda convicción democrática, libertaria y de respeto a la dignidad de los humildes, de quien razonó y actuó siempre convencido de que la base más firme de un genuino desarrollo de México es la justicia social, y de la defensa de la soberanía nacional, la soberanía de un pueblo unido, organizado con independencia y decidido a ejercer sus derechos
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