16,582 research outputs found

    Morbilidade Neonatal e Cesariana Electiva em Recém-Nascidos de Termo

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    INTRODUCTION: International guidelines suggest that non-urgent planned deliveries be scheduled at or after 39 weeks. Despite this recommendation elective cesarean often occurs before 39 weeks. Some research has demonstrated that elective cesarean before 39 weeks poses a greater risk to the infants than at or after 39 weeks. OBJECTIVE: To evaluate neonatal morbidity in term newborns born by elective cesarean section. MATERIAL AND METHODS: Retrospective study of all term elective cesarean sections (scheduled and without labor) performed in level III maternity, in the last 11 years (2003 - 2013). High risk pregnancies were excluded: twins, premature rupture of membranes, preeclampsia, poorly controlled diabetes mellitus, Rh isoimmunization and congenital malformations. Two groups of newborns with gestational age less than 39 weeks and equal or greater than 39 weeks gestational age were compared. RESULTS: In our sample, 45% of elective caesarean sections were performed before 39 weeks. Infants born before 39 weeks were more frequently admitted in neonatal intensive care, odds ratio 2.4 [1.4 - 4.1] p = 0.001, had more respiratory morbidity, odds ratio 2.4 [1.6 - 3.8] p < 0.001, more hyperbilirubinaemia odds ratio 2.3 [1.5 - 3.7] p < 0.001, more hypoglycaemia and/or feeding difficulties odds ratio 1.6 [1.2 - 2.4] p = 0.006, and longer admissions (more than five days), odds ratio 2.0 [1.4 - 3] p < 0.001. DISCUSSION: As in other studies 'early term' had higher respiratory and metabolic morbidity and consequently had a longer hospital stay. CONCLUSION: These findings support recommendations to delay elective cesarean delay until 39 weeks of gestation.info:eu-repo/semantics/publishedVersio

    Birth size and breast cancer risk: Re-analysis of individual participant data from 32 studied

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    Background Birth size, perhaps a proxy for prenatal environment, might be a correlate of subsequent breast cancer risk, but findings from epidemiological studies have been inconsistent. We re-analysed individual participant data from published and unpublished studies to obtain more precise estimates of the magnitude and shape of the birth size–breast cancer association. Methods and Findings Studies were identified through computer-assisted and manual searches, and personal communication with investigators. Individual participant data from 32 studies, comprising 22,058 breast cancer cases, were obtained. Random effect models were used, if appropriate, to combine study-specific estimates of effect. Birth weight was positively associated with breast cancer risk in studies based on birth records (pooled relative risk [RR] per one standard deviation [SD] [= 0.5 kg] increment in birth weight: 1.06; 95% confidence interval [CI] 1.02–1.09) and parental recall when the participants were children (1.02; 95% CI 0.99–1.05), but not in those based on adult self-reports, or maternal recall during the woman's adulthood (0.98; 95% CI 0.95–1.01) (p for heterogeneity between data sources = 0.003). Relative to women who weighed 3.000–3.499 kg, the risk was 0.96 (CI 0.80–1.16) in those who weighed < 2.500 kg, and 1.12 (95% CI 1.00–1.25) in those who weighed ≥ 4.000 kg (p for linear trend = 0.001) in birth record data. Birth length and head circumference from birth records were also positively associated with breast cancer risk (pooled RR per one SD increment: 1.06 [95% CI 1.03–1.10] and 1.09 [95% CI 1.03–1.15], respectively). Simultaneous adjustment for these three birth size variables showed that length was the strongest independent predictor of risk. The birth size effects did not appear to be confounded or mediated by established breast cancer risk factors and were not modified by age or menopausal status. The cumulative incidence of breast cancer per 100 women by age 80 y in the study populations was estimated to be 10.0, 10.0, 10.4, and 11.5 in those who were, respectively, in the bottom, second, third, and top fourths of the birth length distribution. Conclusions This pooled analysis of individual participant data is consistent with birth size, and in particular birth length, being an independent correlate of breast cancer risk in adulthood

    On the long-term correlation between the flux in the Ca II H & K and Halpha lines for FGK stars

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    The re-emission in the cores of the Ca II H & K and Hα\alpha lines, are well known proxies of stellar activity. However, these activity indices probe different activity phenomena, the first being more sensitive to plage variation, while the other one being more sensitive to filaments. In this paper we study the long-term correlation between logRHK\log R'_{HK} and logIHα\log I_{H\alpha}, two indices based on the Ca II H & K and Hα\alpha lines respectively, for a sample of 271 FGK stars using measurements obtained over a \sim9 year time span. Because stellar activity is one of the main obstacles to the detection of low-mass and long-period planets, understanding further this activity index correlation can give us some hints about the optimal target to focus on, and ways to correct for these activity effects. We found a great variety of long-term correlations between logRHK\log R'_{HK} and logIHα\log I_{H\alpha}. Around 20% of our sample has strong positive correlation between the indices while about 3% show strong negative correlation. These fractions are compatible with those found for the case of early-M dwarfs. Stars exhibiting a positive correlation have a tendency to be more active when compared to the median of the sample, while stars showing a negative correlation are more present among higher metallicity stars. There is also a tendency for the positively correlated stars to be more present among the coolest stars, a result which is probably due to the activity level effect on the correlation. Activity level and metallicity seem therefore to be playing a role on the correlation between logRHK\log R'_{HK} and logIHα\log I_{H\alpha}. Possible explanations based on the influence of filaments for the diversity in the correlations between these indices are discussed in this paper.Comment: 18 pages, 13 figures, 4 tables, accepted for publication in Astronomy and Astrophysic

    Is the effect of birth weight on early breast cancer mediated through childhood growth?

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    Link Invariants for Flows in Higher Dimensions

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    Linking numbers in higher dimensions and their generalization including gauge fields are studied in the context of BF theories. The linking numbers associated to nn-manifolds with smooth flows generated by divergence-free p-vector fields, endowed with an invariant flow measure are computed in different cases. They constitute invariants of smooth dynamical systems (for non-singular flows) and generalizes previous results for the 3-dimensional case. In particular, they generalizes to higher dimensions the Arnold's asymptotic Hopf invariant for the three-dimensional case. This invariant is generalized by a twisting with a non-abelian gauge connection. The computation of the asymptotic Jones-Witten invariants for flows is naturally extended to dimension n=2p+1. Finally we give a possible interpretation and implementation of these issues in the context of string theory.Comment: 21+1 pages, LaTeX, no figure

    Transport Processes in Metal-Insulator Granular Layers

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    Tunnel transport processes are considered in a square lattice of metallic nanogranules embedded into insulating host to model tunnel conduction in real metal/insulator granular layers. Based on a simple model with three possible charging states (±\pm, or 0) of a granule and three kinetic processes (creation or recombination of a ±\pm pair, and charge transfer) between neighbor granules, the mean-field kinetic theory is developed. It describes the interplay between charging energy and temperature and between the applied electric field and the Coulomb fields by the non-compensated charge density. The resulting charge and current distributions are found to be essentially different in the free area (FA), between the metallic contacts, or in the contact areas (CA), beneath those contacts. Thus, the steady state dc transport is only compatible with zero charge density and ohmic resistivity in FA, but charge accumulation and non-ohmic behavior are \emph{necessary} for conduction over CA. The approximate analytic solutions are obtained for characteristic regimes (low or high charge density) of such conduction. The comparison is done with the measurement data on tunnel transport in related experimental systems.Comment: 10 pages, 11 figures, 1 reference corrected, acknowlegments adde

    Geomorphological units of mainland Portugal

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    São representadas cartograficamente as unidades geomorfológicas identificadas para os 89015 km2 do território de Portugal Continental. A delimitação das unidades teve por base a análise dos padrões da textura fornecida por imagens SRTM, com revisão e adaptação posterior à altimetria e à geologia, para os quais foram usadas bases cartográficas digitais. Foram considerados três níveis taxionómicos que permitem descrever e caracterizar áreas homogéneas do ponto de vista geomorfológico. As três unidades de 1º nível baseiam-se nas unidades morfostruturais clássicas consideradas para a Península Ibérica. As dez unidades de 2º nível constituem, na sua maioria, divisões clássicas do relevo de Portugal Continental, agora agrupadas de acordo com a metodologia adoptada e designadas como unidades morfosculturais. As 56 unidades de 3º nível, ou subunidades morfosculturais, foram individualizadas com base nos padrões de relevo identifi cados nas imagens SRTM e na observação de campo e adquiriram uma designação baseada essencialmente nas geoformas que as individualizam e na toponímia local. As unidades geomorfológicas identificadas são descritas através de características do relevo, dissecação fluvial, estruturas, tipo de drenagem e base geológica, bem como de parâmetros numéricos gerados de forma automática, como classes de altitude e de declividade. Pretende-se que o mapa elaborado possa contribuir para a gestão territorial, em especial na tomada de decisões em conservação da natureza.Fundação para a Ciência e a Tecnologia (FCT); CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (Brasil

    Quantification of a new water diversity index for large areas using GIS. Examples in Paraná State, Xingu river basin (Brazil) and Portugal

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    (Cuantificación de un nuevo index de diversidad hídrica para grandes áreas con SIG: ejemplos en lo estado del Paraná, en la cuenca del rio Xingú (Brasil) y en Portugal): Se presenta un método para la evaluación cuantitativa de la diversidad de recursos hídricos en grandes áreas, con los ejemplos del estado de Paraná (Brasil), de la Cuenca del rio Xingú (Brasil) y de Portugal continental. En la mayoría de las propuestas metodológicas para evaluación de la geodiversidad, la diversidad hidrológica respecta a las características de la hidrografía, en relación con la diversidad de geoformas fluviales. Este trabajo pretende contribuir al inclusión de recursos hídricos como un elemento significativo en metodologías de evaluación de la geodiversidad, incluyendo tanto las aguas superficiales y aguas subterráneas. El uso de procedimientos de SIG demuestra que estas técnicas pueden ser utilizados para acelerar el cálculo de los índices de diversidad y su representación cartográfica.The Portuguese authors express their gratitude for the financial support given by the FCT (Fundação para a Ciência e a Tecnologia) to the Institute of Earth Sciences (Pole of the University of Minho), which partially supports this research. The Brazilian authors express their gratitude for the financial support given by the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and CAPES (Cordenação de Aperfeiçoamento de Pessoal de Nível Superior).info:eu-repo/semantics/publishedVersio
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