63 resultados para non-additivity of Faradaic current


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OBJETIVO: Estudar associação entre excesso de peso e hábito de fumar. METODOLOGIA: Estudo transversal desenvolvido por telefone numa amostra probabilística de adultos (Santarém /PA), em 2007. Variável desfecho foi excesso de peso, explanatória hábito de fumar e de confusão idade, escolaridade, união conjugal, estado nutricional prévio, abuso de bebidas alcoólicas, atividade física no lazer e padrão alimentar. Associação entre excesso de peso e demais variáveis foi investigada pelo teste do qui-quadrado e regressão de Poisson para o cálculo das razões de prevalência de excesso de peso conforme hábito de fumar, considerando-se três níveis de hierarquia: características sociodemográficas, estado nutricional prévio e padrão comportamental. RESULTADOS: Verificou-se 40,6% de excesso de peso e 16,4% de fumantes. As variáveis associadas ao excesso de peso foram: maior idade, menor escolaridade, união conjugal estável, excesso de peso aos 20 anos e hábito de não consumo de refrigerante para ambos os sexos; não ativo no lazer para homens e hábito de fumar (atual e passado) para mulheres. As razões de prevalência de excesso de peso não apresentaram associação com hábito de fumar para homens, porém para mulheres houve tendência de maior prevalência de excesso de peso para fumantes atuais, chegando a 2,56 vezes mais do que para nunca fumantes e ex-fumantes. CONCLUSÃO: Este estudo constatou que a prevalência de excesso de peso foi maior para mulheres fumantes, comparativamente às ex-fumantes e nunca fumantes. Para os homens não se observou nenhuma associação entre excesso de peso e tabagismo.

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The aim of the current study was to describe the sources of variation of energy and nutrient intake and to calculate the number of repetitions of diet measurements to estimate usual intake in adolescents from São Paulo, Brazil. Data was collected using 24-hour dietary recalls (24hR) in 273 adolescents between 2007 and 2008. Individuals completed a repeat 24hR around two months later. The sources of variation were estimated using the random effect model. Variance ratios (within-person to between-person variance ratio) and the number of repetitions of 24hR to estimate usual intake were calculated. The principal source of variation was due to within-person variance. The contribution of day of week and month of year was less than 8%. Variations ranged from 1.15 for calcium to 7.31 for vitamin E. The number of 24hR repeats required to estimate usual intake varied according to nutrient and gender, numbering 15 for males and 8 for females.

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Ayahuasca is a hallucinogenic beverage prepared by the decoction of plants native to the Amazon Basin region. The beverage has been used throughout the world by members of some syncretic religious movements. Despite the recent legalization of ayahuasca in Brazil for religious purposes, there is little pre-clinical and clinical information attesting to its safety, particularly in relation to the use during pregnancy. The aim of the current work was to determine the effects of perinatal exposure to ayahuasca (from the 6th day of pregnancy to the 10th day of lactation) on physical, reflexology and neurobehavioral parameters of the Wistar rat offspring. The offspring showed no statistically significant changes in the physical and reflexology parameters evaluated. However, in adult rats, perinatally exposed to ayahuasca, an increase in frequency of entries in open arms in elevated plus-maze test, a decrease in total time of interaction in social interaction test, a decrease in time of latency for the animal to start swimming and a decrease of the minimum convulsant dose induced by pentylenetetrazol were observed. In conclusion, our results showed that the use of ayahuasca by mothers during pregnancy and lactation reduced the general anxiety and social motivation of the rat offspring. Besides, it promoted a higher sensitivity for initiation and spread of seizure activity.

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OBJETIVO: Avaliar a fidedignidade das informações sobre dados nutricionais declarados em rótulos de alimentos comercializados. MÉTODOS: Foram avaliados 153 alimentos industrializados habitualmente consumidos por crianças e adolescentes, comercializados no município de São Paulo (SP) entre os anos de 2001 e 2005. Os teores de nutrientes informados pelos rótulos foram confrontados com os resultados obtidos por métodos analíticos (físico-químicos) oficiais, considerando a variabilidade de 20% tolerada pela legislação vigente, para aprovar ou condenar as amostras. Foram calculadas médias, desvios-padrão e intervalos com 95% de confiança para os nutrientes analisados, assim como a distribuição da freqüência percentual de amostras condenadas. RESULTADOS: Todos os produtos salgados analisados apresentaram inconformidades relativamente ao conteúdo de fibra alimentar, sódio ou de gorduras saturadas. Os produtos doces apresentaram variação de zero a 36% de condenação relativamente ao teor de fibra alimentar. Mais da metade (52%) dos biscoitos recheados foram condenados quanto à quantidade de gorduras saturadas. Os nutrientes implicados com a obesidade e suas complicações para a saúde foram aqueles que apresentaram maiores proporções de inconformidade. A falta de fidedignidade das informações de rótulos nas amostras analisadas viola as disposições da Resolução da Diretoria Colegiada 360/03 da ANVISA e os direitos garantidos pela lei de Segurança Alimentar e Nutricional e pelo Código de Defesa do Consumidor. CONCLUSÕES: Foram encontrados altos índices de não conformidade dos dados nutricionais nos rótulos de alimentos destinados ao público adolescente e infantil, indicando a urgência de ações de fiscalização e de outras medidas de rotulagem nutricional

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The purpose of the current study was to understand how visual information about an ongoing change in obstacle size is used during obstacle avoidance for both lead and trail limbs. Participants were required to walk in a dark room and to step over an obstacle edged with a special tape visible in the dark. The obstacle's dimensions were manipulated one step before obstacle clearance by increasing or decreasing its size. Two increasing and two decreasing obstacle conditions were combined with seven control static conditions. Results showed that information about the obstacle's size was acquired and used to modulate trail limb trajectory, but had no effect on lead limb trajectory. The adaptive step was influenced by the time available to acquire and process visual information. In conclusion, visual information about obstacle size acquired during lead limb crossing was used in a feedforward manner to modulate trail limb trajectory.

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Metal oxide-semiconductor capacitors with TiO(x) deposited with different O(2) partial pressures (30%, 35%, and 40%) and annealed at 550, 750, and 1000 degrees C were fabricated and characterized. Fourier transform infrared, x-ray near edge spectroscopy, and elipsometry measurements were performed to characterize the TiO(x) films. TiO(x)N(y) films were also obtained by adding nitrogen to the gaseous mixture and physical results were presented. Capacitance-voltage (1 MHz) and current-voltage measurements were utilized to obtain the effective dielectric constant, effective oxide thickness, leakage current density, and interface quality. The results show that the obtained TiO(x) films present a dielectric constant varying from 40 to 170 and a leakage current density (for V(G)=-1 V, for some structures as low as 1 nA/cm(2), acceptable for complementary metal oxide semiconductor circuits fabrication), indicating that this material is a viable, in terms of leakage current density, highk substitute for current ultrathin dielectric layers. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3043537]

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Background: RRP is a devastating disease in which papillomas in the airway cause hoarseness and breathing difficulty. The disease is caused by human papillomavirus (HPV) 6 or 11 and is very variable. Patients undergo multiple surgeries to maintain a patent airway and in order to communicate vocally. Several small studies have been published in which most have noted that HPV 11 is associated with a more aggressive course. Methodology/Principal Findings: Papilloma biopsies were taken from patients undergoing surgical treatment of RRP and were subjected to HPV typing. 118 patients with juvenile-onset RRP with at least 1 year of clinical data and infected with a single HPV type were analyzed. HPV 11 was encountered in 40% of the patients. By our definition, most of the patients in the sample (81%) had run an aggressive course. The odds of a patient with HPV 11 running an aggressive course were 3.9 times higher than that of patients with HPV 6 (Fisher's exact p = 0.017). However, clinical course was more closely associated with age of the patient (at diagnosis and at the time of the current surgery) than with HPV type. Patients with HPV 11 were diagnosed at a younger age (2.4y) than were those with HPV 6 (3.4y) (p = 0.014). Both by multiple linear regression and by multiple logistic regression HPV type was only weakly associated with metrics of disease course when simultaneously accounting for age. Conclusions/Significance Abstract: The course of RRP is variable and a quarter of the variability can be accounted for by the age of the patient. HPV 11 is more closely associated with a younger age at diagnosis than it is associated with an aggressive clinical course. These data suggest that there are factors other than HPV type and age of the patient that determine disease course.

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Aims. We derive lists of proper-motions and kinematic membership probabilities for 49 open clusters and possible open clusters in the zone of the Bordeaux PM2000 proper motion catalogue (+ 11 degrees <= delta <= + 18 degrees). We test different parametrisations of the proper motion and position distribution functions and select the most successful one. In the light of those results, we analyse some objects individually. Methods. We differenciate between cluster and field member stars, and assign membership probabilities, by applying a new and fully automated method based on both parametrisations of the proper motion and position distribution functions, and genetic algorithm optimization heuristics associated with a derivative-based hill climbing algorithm for the likelihood optimization. Results. We present a catalogue comprising kinematic parameters and associated membership probability lists for 49 open clusters and possible open clusters in the Bordeaux PM2000 catalogue region. We note that this is the first determination of proper motions for five open clusters. We confirm the non-existence of two kinematic populations in the region of 15 previously suspected non-existent objects.

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The energy dependence of the neutrino-iron and antineutrino-iron inclusive charged-current cross sections and their ratio have been measured using a high-statistics sample with the MINOS near detector exposed to the NuMI beam from the main injector at Fermilab. Neutrino and antineutrino fluxes were determined using a low hadronic energy subsample of charged-current events. We report measurements of nu-Fe ((nu) over bar - Fe) cross section in the energy range 3-50 GeV (5-50 GeV) with precision of 2%-8% (3%-9%) and their ratio which is measured with precision 2%-8%. The data set spans the region from low energy, where accurate measurements are sparse, up to the high-energy scaling region where the cross section is well understood.

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We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.

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Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of 7.07 x 10(20) protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of 754 +/- 28(stat) +/- 37(syst) for oscillations among three active flavors. The fraction f(s) of disappearing nu(mu) that may transition to nu(s) is found to be less than 22% at the 90% C.L.

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We report the measurement of the transverse momentum dependence of inclusive J/psi polarization in p + p collisions at root s = 200 GeV performed by the PHENIX Experiment at the Relativistic Heavy Ion Collider. The J/psi polarization is studied in the helicity, Gottfried-Jackson, and Collins-Soper frames for p(T) < 5 GeV/c and vertical bar y vertical bar < 0.35. The polarization in the helicity and Gottfried-Jackson frames is consistent with zero for all transverse momenta, with a slight (1.8 sigma) trend towards longitudinal polarization for transverse momenta above 2 GeV/c. No conclusion is allowed due to the limited acceptance in the Collins-Soper frame and the uncertainties of the current data. The results are compared to observations for other collision systems and center of mass energies and to different quarkonia production models.

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Data collected at the Pierre Auger Observatory are used to establish an upper limit on the diffuse flux of tau neutrinos in the cosmic radiation. Earth-skimming nu(tau) may interact in the Earth's crust and produce a tau lepton by means of charged-current interactions. The tau lepton may emerge from the Earth and decay in the atmosphere to produce a nearly horizontal shower with a typical signature, a persistent electromagnetic component even at very large atmospheric depths. The search procedure to select events induced by tau decays against the background of normal showers induced by cosmic rays is described. The method used to compute the exposure for a detector continuously growing with time is detailed. Systematic uncertainties in the exposure from the detector, the analysis, and the involved physics are discussed. No tau neutrino candidates have been found. For neutrinos in the energy range 2x10(17) eV < E(nu)< 2x10(19) eV, assuming a diffuse spectrum of the form E(nu)(-2), data collected between 1 January 2004 and 30 April 2008 yield a 90% confidence-level upper limit of E(nu)(2)dN(nu tau)/dE(nu)< 9x10(-8) GeV cm(-2) s(-1) sr(-1).

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Medusae and polyps of Clytia are abundantly found in coastal marine environments and one species in the genus-Clytia hemisphaerica (Linnaeus, 1767)-has become an important experimental model. Yet, only 10 species in the genus have had their life cycle investigated. Most species of Clytia are also poorly described, and detailed life cycle and morphological studies are needed for accurate species-level identifications. Here, we investigated the life cycle of Clytia elsaeoswaldae Stechow, 1914, a species described for the tropical western Atlantic and subsequently considered conspecific to the nearly-cosmopolitan species Clytia gracilis (Sars, 1850) and Clytia hemisphaerica, originally described for the temperate North Atlantic. Based on observations of mature medusae and multiple colonies from southeastern Brazil and the U. S. Virgin Islands (type locality), our results show that C. elsaeoswaldae is morphologically distinct from C. gracilis and C. hemisphaerica. The morphological results are corroborated by a multigene phylogenetic analysis of the genus Clytia, which shows that C. gracilis-like species form a polyphyletic group of several species. These results suggest that the nearly-cosmopolitan distribution attributed to some species of Clytia may be due to the non-recognition of morphologically similar species with more restricted ranges.

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Stream discharge-concentration relationships are indicators of terrestrial ecosystem function. Throughout the Amazon and Cerrado regions of Brazil rapid changes in land use and land cover may be altering these hydrochemical relationships. The current analysis focuses on factors controlling the discharge-calcium (Ca) concentration relationship since previous research in these regions has demonstrated both positive and negative slopes in linear log(10)discharge-log(10)Ca concentration regressions. The objective of the current study was to evaluate factors controlling stream discharge-Ca concentration relationships including year, season, stream order, vegetation cover, land use, and soil classification. It was hypothesized that land use and soil class are the most critical attributes controlling discharge-Ca concentration relationships. A multilevel, linear regression approach was utilized with data from 28 streams throughout Brazil. These streams come from three distinct regions and varied broadly in watershed size (< 1 to > 10(6) ha) and discharge (10(-5.7)-10(3.2) m(3) s(-1)). Linear regressions of log(10)Ca versus log(10)discharge in 13 streams have a preponderance of negative slopes with only two streams having significant positive slopes. An ANOVA decomposition suggests the effect of discharge on Ca concentration is large but variable. Vegetation cover, which incorporates aspects of land use, explains the largest proportion of the variance in the effect of discharge on Ca followed by season and year. In contrast, stream order, land use, and soil class explain most of the variation in stream Ca concentration. In the current data set, soil class, which is related to lithology, has an important effect on Ca concentration but land use, likely through its effect on runoff concentration and hydrology, has a greater effect on discharge-concentration relationships.