946 resultados para Binary and ternary correlations
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A doença cardiovascular constitui a causa de morte mais relevante em toda a Europa, incluindo Portugal, e é atualmente considerada como uma junção de doença arterial coronária nas suas diversas apresentações clínicas, eventos cerebrovasculares, doença arterial periférica e insuficiência cardíaca. De modo a contribuir para o estudo da importância de uma intervenção baseada numa estratégia populacional integrada na promoção de estilos de vida saudáveis, a principal finalidade deste estudo consistiu em definir o perfil de risco cardiovascular tendo por base os dados de prevalência de alguns fatores de risco, numa amostra de adultos (792 de ambos os sexos), em várias regiões de Portugal Continental. Para tal foram: caraterizados os hábitos alimentares, o contexto sociodemográfico dos adultos; analisadas as correlações entre o peso, perímetro da cintura, índice de massa corporal e a pressão arterial para ambos os sexos. Os resultados revelaram uma prevalência do excesso de peso, de obesidade e das respetivas caraterísticas, como o aumento do perímetro abdominal, e do IMC, sugerindo um contínuo de risco de doença cardiovascular. Verificou-se também uma elevada prevalência de hipertensão nos sujeitos com excesso de peso, sugerindo a existência de um risco cardiovascular acrescido. Os resultados obtidos neste estudo sustentam a necessidade de serem desenvolvidos planos de intervenção que contribuam para a redução do risco cardiovascular nos adultos. Palavras-chave: Estilos de vida; Hipertensão arterial; Índice de Massa Corporal; Obesidade; Risco Cardiovascular.
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The understanding of the continental carbon budget is essential to predict future climate change. In order to quantify CO₂ and CH₄ fluxes at the regional scale, a measurement system was installed at the former radio tower in Beromünster as part of the Swiss greenhouse gas monitoring network (CarboCount CH). We have been measuring the mixing ratios of CO₂, CH₄ and CO on this tower with sample inlets at 12.5, 44.6, 71.5, 131.6 and 212.5 m above ground level using a cavity ring down spectroscopy (CRDS) analyzer. The first 2-year (December 2012–December 2014) continuous atmospheric record was analyzed for seasonal and diurnal variations and interspecies correlations. In addition, storage fluxes were calculated from the hourly profiles along the tower. The atmospheric growth rates from 2013 to 2014 determined from this 2-year data set were 1.78 ppm yr⁻¹, 9.66 ppb yr⁻¹ and and -1.27 ppb yr⁻¹ for CO₂, CH₄ and CO, respectively. After detrending, clear seasonal cycles were detected for CO₂ and CO, whereas CH₄ showed a stable baseline suggesting a net balance between sources and sinks over the course of the year. CO and CO₂ were strongly correlated (r² > 0.75) in winter (DJF), but almost uncorrelated in summer. In winter, anthropogenic emissions dominate the biospheric CO₂ fluxes and the variations in mixing ratios are large due to reduced vertical mixing. The diurnal variations of all species showed distinct cycles in spring and summer, with the lowest sampling level showing the most pronounced diurnal amplitudes. The storage flux estimates exhibited reasonable diurnal shapes for CO₂, but underestimated the strength of the surface sinks during daytime. This seems plausible, keeping in mind that we were only able to calculate the storage fluxes along the profile of the tower but not the flux into or out of this profile, since no Eddy covariance flux measurements were taken at the top of the tower.
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Les informations sensorielles sont traitées dans le cortex par des réseaux de neurones co-activés qui forment des assemblées neuronales fonctionnelles. Le traitement visuel dans le cortex est régit par différents aspects des caractéristiques neuronales tels que l’aspect anatomique, électrophysiologique et moléculaire. Au sein du cortex visuel primaire, les neurones sont sélectifs à divers attributs des stimuli tels que l’orientation, la direction, le mouvement et la fréquence spatiale. Chacun de ces attributs conduit à une activité de décharge maximale pour une population neuronale spécifique. Les neurones du cortex visuel ont cependant la capacité de changer leur sélectivité en réponse à une exposition prolongée d’un stimulus approprié appelée apprentissage visuel ou adaptation visuelle à un stimulus non préférentiel. De ce fait, l’objectif principal de cette thèse est d’investiguer les mécanismes neuronaux qui régissent le traitement visuel durant une plasticité induite par adaptation chez des animaux adultes. Ces mécanismes sont traités sous différents aspects : la connectivité neuronale, la sélectivité neuronale, les propriétés électrophysiologiques des neurones et les effets des drogues (sérotonine et fluoxétine). Le modèle testé se base sur les colonnes d’orientation du cortex visuel primaire. La présente thèse est subdivisée en quatre principaux chapitres. Le premier chapitre (A) traite de la réorganisation du cortex visuel primaire suite à une plasticité induite par adaptation visuelle. Le second chapitre (B) examine la connectivité neuronale fonctionnelle en se basant sur des corrélations croisées entre paires neuronales ainsi que sur des corrélations d’activités de populations neuronales. Le troisième chapitre (C) met en liaison les aspects cités précédemment (les effets de l’adaptation visuelle et la connectivité fonctionnelle) aux propriétés électrophysiologiques des neurones (deux classes de neurones sont traitées : les neurones à décharge régulière et les neurones à décharge rapide ou burst). Enfin, le dernier chapitre (D) a pour objectif l’étude de l’effet du couplage de l’adaptation visuelle à l’administration de certaines drogues, notamment la sérotonine et la fluoxétine (inhibiteur sélectif de recapture de la sérotonine). Méthodes En utilisant des enregistrements extracellulaires d’activités neuronales dans le cortex visuel primaire (V1) combinés à un processus d’imagerie cérébrale optique intrinsèque, nous enregistrons l’activité de décharge de populations neuronales et nous examinons l’activité de neurones individuels extraite des signaux multi-unitaires. L’analyse de l’activité cérébrale se base sur différents algorithmes : la distinction des propriétés électrophysiologiques des neurones se fait par calcul de l’intervalle de temps entre la vallée et le pic maximal du potentiel d’action (largeur du potentiel d’action), la sélectivité des neurones est basée sur leur taux de décharge à différents stimuli, et la connectivité fonctionnelle utilise des calculs de corrélations croisées. L’utilisation des drogues se fait par administration locale sur la surface du cortex (après une craniotomie et une durotomie). Résultats et conclusions Dans le premier chapitre, nous démontrons la capacité des neurones à modifier leur sélectivité après une période d’adaptation visuelle à un stimulus particulier, ces changements aboutissent à une réorganisation des cartes corticales suivant un patron spécifique. Nous attribuons ce résultat à la flexibilité de groupes fonctionnels de neurones qui étaient longtemps considérés comme des unités anatomiques rigides. En effet, nous observons une restructuration extensive des domaines d’orientation dans le but de remodeler les colonnes d’orientation où chaque stimulus est représenté de façon égale. Ceci est d’autant plus confirmé dans le second chapitre où dans ce cas, les cartes de connectivité fonctionnelle sont investiguées. En accord avec les résultats énumérés précédemment, les cartes de connectivité montrent également une restructuration massive mais de façon intéressante, les neurones utilisent une stratégie de sommation afin de stabiliser leurs poids de connectivité totaux. Ces dynamiques de connectivité sont examinées dans le troisième chapitre en relation avec les propriétés électrophysiologiques des neurones. En effet, deux modes de décharge neuronale permettent la distinction entre deux classes neuronales. Leurs dynamiques de corrélations distinctes suggèrent que ces deux classes jouent des rôles clés différents dans l’encodage et l’intégration des stimuli visuels au sein d’une population neuronale. Enfin, dans le dernier chapitre, l’adaptation visuelle est combinée avec l’administration de certaines substances, notamment la sérotonine (neurotransmetteur) et la fluoxétine (inhibiteur sélectif de recapture de la sérotonine). Ces deux substances produisent un effet similaire en facilitant l’acquisition des stimuli imposés par adaptation. Lorsqu’un stimulus non optimal est présenté en présence de l’une des deux substances, nous observons une augmentation du taux de décharge des neurones en présentant ce stimulus. Nous présentons un modèle neuronal basé sur cette recherche afin d’expliquer les fluctuations du taux de décharge neuronale en présence ou en absence des drogues. Cette thèse présente de nouvelles perspectives quant à la compréhension de l’adaptation des neurones du cortex visuel primaire adulte dans le but de changer leur sélectivité dans un environnement d’apprentissage. Nous montrons qu’il y a un parfait équilibre entre leurs habiletés plastiques et leur dynamique d’homéostasie.
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Includes bibliographies.
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Este estudo objetiva compreender como a Polícia Militar do Estado do Rio de Janeiro pode se valer das redes sociais para potencializar a interlocução com a sociedade e aprimorar seu trabalho e gerando valor público. O referencial teórico buscou contextualizar um panorama privilegiado nesse estudo, considerando o ambiente potencializador de interações propiciado pelas redes sociais e a visão da aplicação no campo da segurança. Foram considerados fatores como a evolução da visão sobre o trabalho policial voltado para a área de segurança, evolução esta motivada pela inserção de conceitos voltados para o pleno exercício da cidadania, para a necessidade de colaboração social nas atividades estatais como caminho para atingir as necessidades das pessoas e realização do trabalho dos órgãos estatais, bem como a forma que este envolvimento social tem se dado no contexto recente na Polícia Militar do Estado, analisada a partir de seus exemplos operacionais observados no campo da segurança, a indicação de uma terminologia própria para o momento de envolvimento desses conceitos no campo da segurança, agregando ferramentas e conceitos voltados a Governança Pública e a utilização das redes sociais através do aplicativo WhatsApp, visto ser este aplicativo um dos de maior alcance no contexto nacional e que reúne características próprias ao escopo da pesquisa. Adicionalmente e buscando entender as práticas organizacionais vivenciadas pela utilização das redes sociais através do WhatsApp, foram realizadas entrevistas semiestruturadas com empresas de comunicação e Unidades Policiais com experiência no assunto, o que propiciou um mapeamento das motivações para utilização das redes sociais, suas formas de operação, bem como dificuldades enfrentadas nesta utilização e resultados para os propósitos das organizações. Além dos resultados apresentados neste estudo, as revelações do campo e suas correlações, propiciaram a elaboração de linha mestra para emprego da ferramenta no contexto da Polícia Militar como parte das implicações do estudo. O estudo demonstrou que as redes sociais são úteis como ferramenta para a interlocução social, entre a Polícia Militar e a sociedade, destacando sua capacidade no campo da prevenção e melhoria da capacidade governamental na segurança.
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This paper discusses methods for the optical teleportation of continuous-variable polarization states. We show that using two pairs of entangled beams, generated using four squeezed beams, perfect teleportation of optical polarization states can be performed. Restricting ourselves to three squeezed beams, we demonstrate that polarization state teleportation can still exceed the classical limit. The three-squeezer schemes involve either the use of quantum nondemolition measurement or biased entanglement generated from a single squeezed beam. We analyze the efficacies of these schemes in terms of fidelity, signal transfer coefficients, and quantum correlations.
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REE analyses were performed on authigenic illitic clay. minerals from Late Permian mudrocks, sandstones and bentonites from the Bowen Basin (Australia). The mixed-layer illite-smectite exhibit REE patterns with an obvious fractionation of the HREE from the LREE and MREE, which is an apparent function of degree of illitization reaction. The highly illitic (R greater than or equal to 3) illite-smectite from the northern Bowen Basin show a depletion of LREE relative to the less illitic (R=0 and 1) clays. In contrast, an enrichment of HREE for the illite-rich clays relative to less. illitic clays is evident for the southern Bowen Basin samples. The North American Shale Composite-normalized (La/Lu)(sn) ratios show negative correlations with the illite content in illite-smectite and positive correlations with the delta(18)O values of the clays for both the northern and southern Bowen Basin samples. These correlations indicate that the increasing depletion of LREE in hydrothermal fluids is a function of increasing water/rock ratios in the northern Bowen Basin. Good negative correlations between (La/Lu)(sn) ratios and illite content in illite-smectite from the southern Bowen Basin suggest the involvement of fluids with higher alkalinity and higher pH in low water/ rock ratio conditions. Increasing HREE enrichment with delta(18)O decrease indicates the effect of increasing temperature at low water/rock ratios in the southern Bowen Basin. Results of the present study confirm the conclusions of some earlier studies suggesting that REE in illitic clay minerals are mobile and fractionated during illitization and that this fact should be considered in studies of sedimentary processes and in identifying provenance. Moreover, our results show that REE systematic of illitic clay minerals can be applied as an useful technique to gain information about physico-chemical conditions during thermal and fluid flow events in certain sedimentary basins. (C) 2003 Elsevier Science B.V. All rights reserved.
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The authors evaluated the efficacy of cholinergic drugs in the treatment of neuroleptic-induced tardive dyskinesia (TD) by a systematic review of the literature on the following agents: choline, lecithin, physostigmine, tacrine, 7-methoxyacridine, ipidacrine, galantamine, donepezil, rivastigmine, eptastigmine, metrifonate, arecoline, RS 86, xanomeline, cevimeline, deanol, and meclofenoxate. All relevant randomized controlled trials, without any language or year limitations, were obtained from the Cochrane Schizophrenia Group's Register of Trials. Trials were classified according to their methodological quality. For binary and continuous data, relative risks (RR) and weighted or standardized mean differences (SMD) were calculated, respectively. Eleven trials with a total of 261 randomized patients were included in the meta-analysis. Cholinergic drugs showed a minor trend for improvement of tardive dyskinesia symptoms, but results were not statistically significant (RR 0.84, 95% confidence interval (CI) 0.68 to 1.04, p=0.11). Despite an extensive search of the literature, eligible data for the meta-analysis were few and no results reached statistical significance. In conclusion, we found no evidence to support administration of the old cholinergic agents lecithin, deanol, and meclofenoxate to patients with tardive dyskinesia. In addition, two trials were found on novel cholinergic Alzheimer drugs in tardive dyskinesia, one of which was ongoing. Further investigation of the clinical effects of novel cholinergic agents in tardive dyskinesia is warranted. (C) 2004 Elsevier Inc. All rights reserved.
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Objective: To examine the performance of the Norwegian version of the AUSCAN Index as a disease-specific health status measure in patients with hand osteoarthritis (OA). Methods: One hundred and ninety-nine patients with clinical hand OA (mean (SD) age 61.7 (5.7) years, 18 (9%) males) underwent a comprehensive examination including joint status, examination of grip strength and completion of several self-reported health status questionnaires. The Australian/Canadian OA hand index (AUSCAN) captures three different dimensions of hand OA: pain (5 items), stiffness (1 item), and difficulties with daily activities (9 items). Our pre-study hypothesis was to identify AUSCAN as a specific hand measure with strong correlations to hand measures and lower correlations to other general measures of health. Results: Patient completion of the AUSCAN Index was similar or better than other measures. The internal consistency of the AUSCAN was excellent. The pain and physical dimension of AUSCAN correlated substantially to, each other and moderately to the stiffness scale. The AUSCAN physical scale correlated moderately to substantially to other measures, the highest correlation being seen with the Arthritis Impact Measurement Scale (AIMS) 2 hand and finger function scale (r= 0.73). The standardised differences between patients with and without radiographic abnormalities were numerically larger for the AUSCAN pain and physical scales than for other measures. Conclusion: The Norwegian version of the AUSCAN has an acceptable clinimetric performance and is a suitable tool for assessment of hand OA. (C) 2005 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
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Background: Intermediate phenotypes are often measured as a proxy for asthma. It is largely unclear to what extent the same set of environmental or genetic factors regulate these traits. Objective: Estimate the environmental and genetic correlations between self-reported and clinical asthma traits. Methods: A total of 3073 subjects from 802 families were ascertained through a twin proband. Traits measured included self-reported asthma, airway histamine responsiveness (AHR), skin prick response to common allergens including house dust mite (Dermatophagoides pteronyssinus [D. pter]), baseline lung function, total serum immunoglobulin E (IgE) and eosinophilia. Bivariate and multivariate analyses of eight traits were performed with adjustment for ascertainment and significant covariates. Results: Overall 2716 participants completed an asthma questionnaire and 2087 were clinically tested, including 1289 self-reported asthmatics (92% previously diagnosed by a doctor). Asthma, AHR, markers of allergic sensitization and eosinophilia had significant environmental correlations with each other (range: 0.23-0.89). Baseline forced expiratory volume in 1 s (FEV1) showed low environmental correlations with most traits. Fewer genetic correlations were significantly different from zero. Phenotypes with greatest genetic similarity were asthma and atopy (0.46), IgE and eosinophilia (0.44), AHR and D. pter (0.43) and AHR and airway obstruction (-0.43). Traits with greatest genetic dissimilarity were FEV1 and atopy (0.05), airway obstruction and IgE (0.07) and FEV1 and D. pter (0.11). Conclusion: These results suggest that the same set of environmental factors regulates the variation of many asthma traits. In addition, although most traits are regulated to great extent by specific genetic factors, there is still some degree of genetic overlap that could be exploited by multivariate linkage approaches.
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After conceptual clarification of international business cycle and a review of the literature, a new indicator is proposed. This indicator refers to two time series only and allows for an internationally comparable quantification of a country's position in the business cycle. We then calculate times series of this indicator for 30 countries from 1970-2000. After some plausibility checks, we refer to these series to test a number of hypotheses. Cross correlations reveal a high degree of interconnectedness. Moreover, the number of highly positive correlations has increased over time, whereas the number of low and moderate correlations has decreased. A principal components analysis yields a first component that can be interpreted as the world business cycle. The further components suggest the existence of a Scandinavian-Anglo-Saxon business cycle as well as of another, smaller group of Anglo-Saxon countries that move together. This finding is replicated by a hierarchical cluster analysis, which in addition suggests a closely integrated group of non-Scandinavian and non-English speaking European countries plus Japan and Israel. Furthermore, there is indication for some, albeit weak business cycle integration in Southeast Asia and in South America. The international business cycle is thus found to have a hierarchical structure.
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Purpose: This Study evaluated the predictive validity of three previously published ActiGraph energy expenditure (EE) prediction equations developed for children and adolescents. Methods: A total of 45 healthy children and adolescents (mean age: 13.7 +/- 2.6 yr) completed four 5-min activity trials (normal walking. brisk walking, easy running, and fast running) in ail indoor exercise facility. During each trial, participants were all ActiGraph accelerometer oil the right hip. EE was monitored breath by breath using the Cosmed K4b(2) portable indirect calorimetry system. Differences and associations between measured and predicted EE were assessed using dependent t-tests and Pearson correlations, respectively. Classification accuracy was assessed using percent agreement, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve, Results: None of the equations accurately predicted mean energy expenditure during each of the four activity trials. Each equation, however, accurately predicted mean EE in at least one activity trial. The Puyau equation accurately predicted EE during slow walking. The Trost equation accurately predicted EE during slow running. The Freedson equation accurately predicted EE during fast running. None of the three equations accurately predicted EE during brisk walking. The equations exhibited fair to excellent classification accuracy with respect to activity intensity. with the Trost equation exhibiting the highest classification accuracy and the Puyau equation exhibiting the lowest. Conclusions: These data suggest that the three accelerometer prediction equations do not accurately predict EE on a minute-by-minute basis in children and adolescents during overground walking and running. The equations maybe, however, for estimating participation in moderate and vigorous activity.
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A restricted maximum likelihood analysis applied to an animal model showed no significant differences (P > 0.05) in pH value of the longissimus dorsi measured at 24 h post-mortem (pH24) between high and low lines of Large White pigs selected over 4 years for post-weaning growth rate on restricted feeding. Genetic and phenotypic correlations between pH24 and production and carcass traits were estimated using all performance testing records combined with the pH24 measurements (5.05–7.02) on slaughtered animals. The estimate of heritability for pH24 was moderate (0.29 ± 0.18). Genetic correlations between pH24 and production or carcass composition traits, except for ultrasonic backfat (UBF), were not significantly different from zero. UBF had a moderate, positive genetic correlation with pH24 (0.24 ± 0.33). These estimates of genetic correlations affirmed that selection for increased growth rate on restricted feeding is likely to result in limited changes in pH24 and pork quality since the selection does not put a high emphasis on reduced fatness.
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A long-term planning method for the electricity market is to simulate market operation into the future. Outputs from market simulation include indicators for transmission augmentation and new generation investment. A key input to market simulations is demand forecasts. For market simulation purposes, regional demand forecasts for each half-hour interval of the forecasting horizon are required, and they must accurately represent realistic demand profiles and interregional demand relationships. In this paper, a demand model is developed to accurately model these relationships. The effects of uncertainty in weather patterns and inherent correlations between regional demands on market simulation results are presented. This work signifies the advantages of probabilistic modeling of demand levels when making market-based planning decisions.
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O período de transição para a universidade constitui-se um desafio para os estudantes devido à quantidade e à diversidade de mudanças originadas por um novo contexto pessoal e social que exige o desenvolvimento de recursos adaptativos. A vulnerabilidade trazida por essa fase pode motivar o uso de álcool e outras drogas, sendo um padrão recorrente encontrado em universitários. O bem-estar subjetivo (BES) e a autoeficácia (AE) são exemplos de fatores de proteção capazes de influenciar os comportamentos e atitudes dos jovens diante de situações como o consumo de bebidas alcoólicas. Sendo assim, o objetivo geral deste estudo foi analisar a capacidade explicativa do bem-estar subjetivo e da autoeficácia sobre o consumo de álcool em universitários. A amostra pesquisada foi constituída por 405 estudantes universitários de cursos da área da saúde da região metropolitana de São Paulo, com uma idade média de 21,69 (DP= 5,49), sendo a maioria do sexo feminino (81,5%), cursando o primeiro ou o segundo semestre, tanto do período matutino quanto do noturno. A análise dos dados foi realizada utilizando-se o programa SPSS, versão 20.0 para Windows para a realização de cálculos descritivos e exploratórios: média, desvio-padrão, correlações, análise de regressão múltipla, análises de variância (ANOVA) e teste t de Student. Os resultados do estudo revelaram que os universitários apresentaram um baixo nível de bem-estar subjetivo, autoeficácia acima da média e baixo consumo de álcool, sendo classificados na sua maioria como abstinentes. Foram observados indícios de que o bem-estar subjetivo e a autoeficácia predizem, ainda que de forma limitada, o consumo de álcool, destacando-se com maior capacidade preditiva os afetos negativos, a autoeficácia em ações pró-ativas e a autoeficácia em interação social. Além disso, a análise de correlação (r de Pearson) revelou que BES e AE guardam relação entre si, apresentando índices positivos e significativos. Também foram verificadas correlações significativas e negativas entre o consumo de álcool, a autoeficácia total e seus fatores, assim como correlações significativas e positivas entre o consumo de álcool e afetos negativos. Adicionalmente, é possível concluir que, no grupo estudado, dentre os jovens que consumiram álcool, estudantes do sexo masculino demonstraram um consumo maior da bebida do que as mulheres.