927 resultados para Multiple Change-point Analysis


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introdução - A vitamina D desempenha funções na regulação da homeostase do cálcio e fósforo, diferenciação celular, metabolismo de hormônios e regulação do sistema imune. Sua deficiência em crianças pode ocasionar raquitismo, convulsões e insuficiência respiratória. Objetivo - Determinar a relação entre adiposidade materna e do recém-nascido com as concentrações de vitamina D materna e do cordão umbilical. Metodologia - Foram envolvidas 101 mães e seus respectivos recém-nascidos selecionados no Hospital Maternidade Vila Nova Cachoeirinha, São Paulo. A concentração de vitamina D foi determinada por cromatografia líquida. A composição corporal materna foi determinada por bioimpedância segmentada (InBody®, Coréia do Sul) e a dos recém-nascidos obtida por pletismografia por deslocamento de ar (PEA POD®, USA). Para análise estatística, utilizou-se análise de regressão linear múltipla e coeficiente de correlação de Spearman. Valores de p <0,05 foram considerados significantes. Resultados - As médias das concentrações de vitamina D da mãe e do cordão umbilical foram de 30,16 (DP=21,16) ng/mL e 9,56 (DP=7,25) ng/mL, respectivamente. As médias das porcentagens de massa gorda das mães e dos recém-nascidos foram de 32,32 (DP=7,74) por cento e 8,55 (DP=4,37) por cento , respectivamente. Foi observada relação positiva entre concentração de vitamina D materna e do cordão umbilical (r=0,210; p<0,04). Não foi observada associação entre adiposidade do recém-nascido e concentração de vitamina D do cordão umbilical, nem entre adiposidade materna e concentrações de vitamina D materna e do cordão umbilical. Conclusão Neste estudo, original na literatura internacional, foi utilizado método de referência, validado, de alta precisão e imparcial na estimativa do percentual de gordura neonatal, nem sempre utilizado em outros estudos. Foi observada relação positiva entre concentração de vitamina D materna e do cordão umbilical. A ausência de associação entre as variáveis analisadas pode ser devido à alta prevalência de sobrepeso e obesidade entre as gestantes, baixas concentrações de vitamina D nas gestantes e recém-nascidos, alteração do metabolismo da vitamina D e da composição corporal no período da gestação e imaturidade do processo de sequestro da vitamina D pelo tecido adiposo 1 neonatal. Torna-se relevante o desenvolvimento de estudos prospectivos do tipo coorte para avaliar desde o início da gestação a influência da adiposidaidade materna nas concentrações de vitamina D materna e do cordão umbilical.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objetivos: Avaliar a capacidade funcional de pacientes vítimas de trauma um ano após alta hospitalar e verificar associação da capacidade funcional com fatores relacionados ao trauma e à internação hospitalar. Metodologia: Estudo de coorte prospectivo, com pacientes vítimas de trauma grave (Injury Severity Score - ISS >=16), internados entre Junho e Setembro de 2010 em unidade de terapia intensiva (UTI) cirúrgica especializada em paciente politraumatizado de um hospital público de grande porte na cidade de São Paulo, Brasil. Variáveis de interesse como idade, sexo, escore de Glasgow, Acute Physiology and Chronic Health Disease Classification System II (APACHE II), mecanismos de trauma, número de lesões, região corpórea afetada, número de cirurgias, duração da ventilação mecânica (VM) e tempo de internação hospitalar foram coletadas dos prontuários médicos. A capacidade funcional foi avaliada um ano após alta hospitalar utilizando as escalas Glasgow Outcome Scale (GOS) e Escala de Atividades Instrumentais de Vida Diária de Lawton (AIVDL). Os pacientes também foram questionados se haviam retornado ao trabalho ou estudo. Resultados: O seguimento um ano após trauma foi completo em 49 indivíduos, a maioria composta por jovens (36±11 anos), do sexo masculino (81,6%) e vítimas de acidentes de trânsito (71,5%). Cada indivíduo sofreu aproximadamente 4 lesões corporais, acarretando uma média no ISS de 31 ± 14,4. O traumatismo cranioencefálico foi o tipo de lesão mais comum (65,3%). De acordo com a GOS, a maioria dos pacientes apresentou disfunção moderada (43%) ou disfunção leve ou ausente (37%) um ano após o trauma. A escala AIVDL apresentou pontuação média de 12±4 com aproximadamente 60- 70% dos indivíduos capazes de realizar de forma independente a maioria das atividades avaliadas. Escore de Glasgow, APACHE II, duração da VM e tempo de internação hospitalar foram associadas com a capacidade funcional um ano após lesão. A regressão linear múltipla considerando todas as variáveis significativas revelou associação entre a pontuação da escala AIVDL e o tempo de internação hospitalar. Apenas 32,6% dos indivíduos retornaram ao trabalho ou estudo. Conclusões: A maioria dos pacientes vítimas de trauma grave foi capaz de realizar as atividades avaliadas com independência; apenas um terço deles retornou ao trabalho e/ou estudo um ano após alta hospitalar. O tempo de internação hospitalar foi revelado como preditor significativo para a recuperação da capacidade funcional um ano após lesão grave

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The investigation of biologically initiated pathways to psychological disorder is critical to advance our understanding of mental illness. Research has suggested that attention bias to emotion may be an intermediate trait for depression associated with biologically plausible candidate genes, such as the serotonin transporter (5-HTTLPR) and catechol-o-methyl-transferase (COMT) genes, yet there have been mixed findings in regards to the precise direction of effects. The experience of recent stressful life events (SLEs) may be an important, yet currently unstudied, moderator of the relationship between genes and attention bias as SLEs have been associated with both gene expression and attention to emotion. Additionally, although attention biases to emotion have been studied as a possible intermediate trait associated with depression, no study has examined whether attention biases within the context of measured genetic risk lead to increased risk for clinical depressive episodes over time. Therefore, this research investigated both whether SLEs moderate the link between genetic risk (5-HTTLPR and COMT) and attention bias to emotion and whether 5-HTTLPR and COMT moderated the relationship between attention biases to emotional faces and clinical depression onset prospectively across 18 months within a large community sample of youth (n= 467). Analyses revealed a differential effect of gene. Youth who were homozygous for the low expressing allele of 5-HTTLPR (S/S) and had experienced more recent SLEs within the last three months demonstrated preferential attention toward negative emotional faces (angry and sad). However, youth who were homozygous for the high expressing COMT genotype (Val/Val) and had experienced more recent SLEs showed attentional avoidance of positive facial expressions (happy). Additionally, youth who avoided negative emotion (i.e., anger) and were homozygous for the S allele of the 5-HTTLPR gene were at greater risk for prospective depressive episode onset. Increased risk for depression onset was specific to the 5-HTTLPR gene and was not found when examining moderation by COMT. These findings highlight the importance of examining risk for depression across multiple levels of analysis, such as combined genetic, environmental, and cognitive risk, and is the first study to demonstrate clear evidence of attention biases to emotion functioning as an intermediate trait predicting depression.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O propósito deste estudo foi contribuir para a análise da epidemiologia da oclusão dentária na infância e discutir a implicação para os sistemas de saúde, examinando dados de prevalência de uma amostra probabilística (n=985) da população de 5 e 12 anos de idade na cidade de São Paulo, Brasil (1996); e estudos epidemiológicos transversais publicados nos últimos 70 anos. A prevalência na cidade, cresceu de 49,0 ± 4,5 por cento na dentição decídua para 71,3 ± 3,9 por cento na dentição permanente (p<0,001), sendo que a chance de ocorrência de oclusopatia moderada/severa foi quase duas vezes maior na segunda dentição (OR=1,87; IC95 por cento =1,43-2,45; p

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study examines worldwide usage of over 600,000 e-books from Ebook Library (EBL) and ebrary. Using multiple modes of analysis, the study shows that there are variations in usage by geographic region as well as by subject. The study examines usage in relation to availability of titles, different types of usage per session, usage of the top ten percent of titles, and intensive and extensive use. These patterns can be used for benchmarking and as a model for local e-book studies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El Tolmo de Minateda (Hellín, Albacete) ofrece una secuencia estratigráfica sin solución de continuidad entre los siglos VII y IX d. D. En este trabajo se discute la potencialidad explicativa de dicha secuencia aplicada a la cerámica y a la arquitectura altomedievales, como instrumentos de reconocimiento del cambio social y cultural. El análisis de ambos casos de estudio permite la caracterización material del siglo VIII y plantea interesantes cuestiones arqueológicas en torno al significado histórico del 711.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El presente estudio tiene como objeto analizar la abundancia y distribución de la urraca en función de las diferentes matrices de usos del suelo y gradientes ambientales. Este trabajo se ha centrado en la Comarca de la Marina Baja (Alicante), una región con 578,8 Km² de superficie. La zona cuenta con una vegetación climática de carrascal de termotipo mesomediterráneo y ombrotipo seco y subhúmedo. Se han realizado un total de 396 transectos para estimar la abundancia de la urraca durante los años 2006-2008, en diferentes matrices del paisaje: natural, abandono, regadío y secano. Las abundancias relativas, la evolución de la especie, el efecto sobre otras especies de caza y el efecto que tiene el control poblacional de las urracas se ha obtenido de 21 encuestas realizadas a los gestores de los terrenos cinegéticos. El análisis de los resultados, muestra una mayor abundancia de los individuos en zonas de cultivo de secano (IKA=0.76 aves/km) y cultivos abandonados (IKA=0.73 aves/km), siendo los valores medios anuales cada vez mayores desde el inicio del muestreo. El análisis múltiple de regresión lineal de la abundancia de urraca con la matriz de usos del suelo muestra una relación significativa y positiva con el abandono antiguo (p<0.01), el frutal de secano y las zonas húmedas (p<0.05), mientras que no hay relación significativa (p>0.05) con los índices del paisaje. El análisis ANOVA muestra que las variables significativas influyentes sobre el número de urracas son: matriz de usos del suelo, latitud/ombroclima, continentalidad y la interacción usos del suelo:continentalidad (p<0.05). La urraca ha experimentado un aumento en sus poblaciones desde principios de la primera década del actual siglo. Los cotos que realizan un control sobre la población de urracas tienen un efecto positivo que se ve reflejado en la menor afección sobre otras especies cinegéticas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This article shows how the cognitive mobilization index, designed for use in observing potential political participation, can be used as an indicator of the political climate that a particular society is going through. Following a discussion of the theoretical elaborations (and their working definitions) of the concept of cognitive mobilization, a longitudinal study of various European countries is used to consider the question of how political crises influence cognitive mobilization indexes and what effects they have on the political socialization process among the youngest cohorts.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose: To evaluate the relationship between different ocular and corneal biomechanical parameters in emmetropic and ametropic healthy white children. Methods: This study included 293 eyes of 293 healthy Spanish children (135 boys and 158 girls), ranging in age from 6 to 17 years. Subjects were divided according to the refractive error: control (emmetropia, 99 children), myopia (100 children), and hyperopia (94 children) groups. In all cases, corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated with the Ocular Response Analyzer system. Axial length (AL) and mean corneal power were also measured by partial coherence interferometry (IOLMaster), and central corneal thickness (CCT) and anterior chamber depth were measured by anterior segment optical coherence tomography (Visante). Results: Mean (±SD) CH and CRF were 12.12 (±1.71) and 12.30 (±1.89) mm Hg, respectively. Mean (±SD) CCT was 542.68 (±37.20) μm and mean (±SD) spherical equivalent was +0.14 (±3.41) diopters. A positive correlation was found between CH and CRF (p < 0.001), and both correlated as well with CCT (p < 0.0001). Corneal resistance factor was found to decrease with increasing age (p = 0.01). Lower levels of CH were associated with longer AL and more myopia (p < 0.001 and p = 0.001, respectively). Higher values of CH were associated with increasing hyperopia. Significant differences in CH were found between emmetropic and myopic groups (p < 0.001) and between myopic and hyperopic groups (p = 0.011). There were also significant differences in CRF between emmetropic and myopic groups (p = 0.02). Multiple linear regression analysis showed that lower CH and CRF significantly associated with thinner CCT, longer AL, and flatter corneal curvature. Conclusions: The Ocular Response Analyzer corneal biomechanical properties seem to be compromised in myopia from an early age, especially in high myopia.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recent research has highlighted that in the last few years the evolution of regional disparities in many European states has become pro-cyclical. This represents a change with respect to the predominantly anti-cyclical pattern of the 1960s and 1970s. This paper addresses the question of whether and when this change has taken place in the southern periphery of Europe, before analyzing the factors that may have played a role in such a change. The analysis relies on a regional database that includes the evolution of the GDP per capita of NUTS II regions in five European countries (France, Greece, Italy, Portugal, and Spain) between 1980 and 2000. The results of the analysis support the hypothesis of a change towards a pro-cyclical evolution of regional disparities in the cases of Italy, Portugal, and Spain, but not in those of Greece and France. A relationship between these pro-cyclical patters and the emergence of less dynamic sheltered economies is also detected in peripheral regions. This lack of dynamism is related to the fact that numerous peripheral areas in southern Europe have become increasingly dependent on factors such as transfers or public investment and employment, and therefore are less exposed to changes in market conditions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We compare eight pollen records reflecting climatic and environmental change from the tropical Andes. Our analysis focuses on the last 50 ka, with particular emphasis on the Pleistocene to Holocene transition. We explore ecological grouping and downcore ordination results as two approaches for extracting environmental variability from pollen records. We also use the records of aquatic and shoreline vegetation as markers for lake level fluctuations, and precipitation change. Our analysis focuses on the signature of millennial-scale variability in the tropical Andes, in particular, Heinrich stadials and Greenland interstadials. We identify rapid responses of the tropical vegetation to this climate variability, and relate differences between sites to moisture sources and site sensitivity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Low temperature alteration of oceanic basement rocks is characterized by net gain of sulfur, which commonly yields low d34S values, suggesting involvement of microbial sulfate reduction. In order to test whether secondary sulfide minerals are consistent with a biogenic source, we apply high precision multiple sulfur isotope analysis to bulk rock sulfide and pyrite isolates from two contrasting types of altered oceanic basement rocks, namely serpentinized peridotites and altered basalts. Samples from two peridotite sites (Iberian Margin and Hess Deep) and from a basalt site on the eastern flank of the Juan de Fuca Ridge yield overlapping d34S values ranging from 0 per mil to -44 per mil. In contrast, sulfides in the basalt site are characterized by relatively low D33S values ranging from -0.06 per mil to 0.04 per mil, compared to those from peridotite sites (0.00 per mil to 0.16 per mil). The observed D33S signal is significant considering the analytical precision of 0.014 per mil (2 sigma). We present a batch reaction model that uses observed d34S and D33S relationships to quantify the effect of closed system processes and constrain the isotope enrichment factor intrinsic to sulfate reduction. The estimated enrichment factors as large as 61 per mil and 53 per mil, for peridotite and basalt sites respectively, suggest the involvement of microbial sulfate reduction. The relatively high D33S values in the peridotite sites are due to sulfate reduction in a closed system environment, whereas negative D33S values in the basalt site reflect open system sulfate reduction. A larger extent of sulfate reduction during alteration of peridotite to serpentinite is consistent with its higher H2 production capacity compared to basalt alteration, and further supports in-situ microbial sulfate reduction coupled with H2 production during serpentinization reactions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Bulk mineralogy of the terrigenous fraction of 99 samples from ODP Site 722 on the Owen Ridge, western Arabian Sea, has been determined by x-ray diffraction, using an internal standard method. The sampling interval, approximately 4.3 k.y., provides a detailed mineralogic record for the past 500 k.y. Previous studies have identified important modern continental sediment sources and the mineral assemblages presently derived from each. These studies have also demonstrated that most of this material is supplied by southwest and northwest winds during the summer monsoon. A variety of marine and terrestrial records and general circulation model (GCM) simulations have indicated the importance of monsoonal circulation during the Pleistocene and Holocene and have demonstrated increased aridity during glacial times and increased humidity during inter glacials. The mineralogic data generated here were used to investigate variations in source area weathering conditions during these environmental changes. Terrigenous minerals present include smectite, illite, palygorskite, kaolinite, chlorite, quartz, plagioclase feldspar, and dolomite. This mineralogy is consistent with the compositions of source areas presently supplying sediment to the Arabian Sea. An R-mode factor analysis has identified four mineral assemblages present throughout the past 500 k.y.: quartz/chlorite/dolomite (Factor 1), kaolinite/plagioclase/illite (Factor 2), smectite (Factor 3), and palygorskite/dolomite (Factor 4). Chlorite, illite, and palygorskite are extremely susceptible to chemical weathering, and a spectral comparison of these factors with the eolian mass accumulation rate (MAR) record from Hole 722B (an index of dust source area aridity) indicates that Factors 1, 2, and 4 are directly related to changes in aridity. Because of these characteristics, Factors 1,2, and 4 are interpreted to originate from arid source regions. Factor 3 is interpreted to record more humid source conditions. Time-series of scores for the four factors are dominated by short-term (10-100 k.y.) variability, and do not correlate well to glacial/interglacial fluctuations in the time domain. These characteristics suggest that local climatic shifts were complex, and that equilibrium weathering assemblages did not develop immediately after climatic change. Spectral analysis of factor scores identifies peaks at or near the primary Milankovitch frequencies for all factors. Factor 1 (quartz/chlorite/dolomite), Factor 2 (kaolinite/plagioclase/illite), and Factor 4 (illite/palygorskite) are coherent and in phase with the MAR record over the 23, 41, and 100 k.y. bands, respectively. The reasons for coherency at single Milankovitch frequencies are not known, but may include differences in the susceptibilities of minerals to varying time scales of weathering and/or preferential development of suitable continental source environments by climatic changes at the various Milankovitch frequencies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thesis (Master's)--University of Washington, 2016-06

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thesis (Master's)--University of Washington, 2016-06