936 resultados para Cluster Analysis of Variables
Resumo:
The aim of this work is to study the local impact on the upper troposphere/lower stratosphere air composition of an extreme deep convective system. For this purpose, we performed a simulation of a convective cluster composed of many individual deep convective cells that occurred near Bauru (Brazil). The simulation is performed using the 3-D mesoscale model RAMS coupled on-line with a chemistry model. The comparisons with meteorological measurements show that the model produces meteorological fields generally consistent with the observations. The present paper (part I) is devoted to the analysis of the ozone precursors (CO, NO x and non-methane volatile organic compounds) and HO x in the UTLS. The simulation results show that the distribution of CO with altitude is closely related to the upward convective motions and consecutive outflow at the top of the convective cells leading to a bulge of CO between 7 km altitude and the tropopause (around 17km altitude). The model results for CO are consistent with satellite-borne measurements at 700 hPa. The simulation also indicates enhanced amounts of NO x up to 2 ppbv in the 7-17 km altitude layer mainly produced by the lightning associated with the intense convective activity. For insoluble non-methane volatile organic compounds, the convective activity tends to significantly increase their amount in the 7-17km layer by dynamical effects. During daytime in the presence of lightning NO x, this bulge is largely reduced in the upper part of the layer for reactive species (e.g. isoprene, ethene) because of their reactions with OH that is increased on average during daytime. Lightning NO x also impacts on the oxydizing capacity of the upper troposphere by reducing on average HO x, HO 2, H 2O 2 and organic hydroperoxides. During the simulation time, the impact of convection on the air composition of the lower stratosphere is negligible for all ozone precursors although several of the simulated convective cells nearly reach the tropopause. There is no significant transport from the upper troposphere to the lower stratosphere, the isentropic barrier not being crossed by convection. The impact of the increase of ozone precursors and HO x in the upper troposphere on the ozone budget in the LS is discussed in part II of this series of papers.
Resumo:
The objective of this study was to analyze randomized controlled trials published in the last decades involving motor intervention as a treatment for dementia, based on Physiotherapy Evidence Database (PEDro) criteria. A database search was performed using the following keywords: randomized controlled trial, dementia, physiotherapy, physical therapy, occupational therapy, physical education, motor approach, exercise, and physical activity. Ten trials were found: 4 related to physiotherapy, 3 to occupational therapy, 1 to physical education, and 2 to interdisciplinary motor intervention. The efficacy of motor intervention was confirmed in the following variables: psychosocial function, physical health and function, affective status, and caregiver's distress (P < .05). Results related to mobility were not significant (P > .05). Behavior, cognitive performance, activities of daily living, and risk of falls were not similar among the articles. From a total score of 10 points, with excellence characterized as the highest punctuation, the articles were classified between 3 and 7 by PEDro. Motor intervention was shown to be an alternative for minimizing physical and mental decline. PEDro has been confirmed as a very reliable tool to analyze studies and as an evaluation criteria, both qualitative and quantitative, allowing the establishment of motor intervention strategies for the treatment of patients with dementia. © 2007 Lippincott Williams & Wilkins, Inc.
Resumo:
This paper presents an analyze of numeric conditioning of the Hessian matrix of Lagrangian of modified barrier function Lagrangian method (MBFL) and primal-dual logarithmic barrier method (PDLB), which are obtained in the process of solution of an optimal power flow problem (OPF). This analyze is done by a comparative study through the singular values decomposition (SVD) of those matrixes. In the MBLF method the inequality constraints are treated by the modified barrier and PDLB methods. The inequality constraints are transformed into equalities by introducing positive auxiliary variables and are perturbed by the barrier parameter. The first-order necessary conditions of the Lagrangian function are solved by Newton's method. The perturbation of the auxiliary variables results in an expansion of the feasible set of the original problem, allowing the limits of the inequality constraints to be reached. The electric systems IEEE 14, 162 and 300 buses were used in the comparative analysis. ©2007 IEEE.
Resumo:
This paper investigates the major similarities and discrepancies among three important current decompositions proposed for the interpretation of unbalanced and/or non linear three-phase four-wire power circuits. The considered approaches were the so-called FBD Theory, the pq-Theory and the CPT. Although the methods are based on different concepts, the results obtained under ideal conditions (sinusoidal and balanced signals) are very similar. The main differences appear in the presence of unbalanced and non linear load conditions. It will be demonstrated and discussed how the choice of the voltage referential and the return conductor impedance can influence in the resulting current components, as well as, the way of interpreting a power circuit with return conductor. Under linear unbalanced conditions, both FBD and pq-Theory suggest that the some current components contain a third-order harmonic. Besides, neither pq-Theory nor FBD method are able to provide accurate information for reactive current under unbalanced and distorted conditions, what can be done by means of the CPT. © 2009 IEEE.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Incluye bibliografía
Resumo:
Includes bibliography
Resumo:
Includes bibliography
Electroglottographic analysis of actresses and nonactresses' voices in different levels of intensity
Resumo:
Background: Previous studies with long-term average spectrum (LTAS) showed the importance of the glottal source for understanding the projected voices of actresses. In this study, electroglottographic (EGG) analysis was used to investigate the contribution of the glottal source to the projected voice, comparing actresses and nonactresses' voices, in different levels of intensity. Method: Thirty actresses and 30 nonactresses sustained vowels in habitual, moderate, and loud intensity levels. The EGG variables were contact quotient (CQ), closing quotient (QCQ), and opening quotient (QOQ). Other variables were sound pressure level (SPL) and fundamental frequency (F0). A KayPENTAX EGG was used. Variables were inputted in a general linear model. Results/Discussion: Actresses showed significantly higher values for SPL, in all levels, and both groups increased SPL significantly while changing from habitual to moderate and further to loud. There were no significant differences between groups for EGG quotients. There were significant differences between the levels only for F0 and CQ for both groups. Conclusion: SPL was significantly higher among actresses in all intensity levels, but in the EGG analysis, no differences were found. This apparently weak contribution of the glottal source in the supposedly projected voices of actresses, contrary to previous LTAS studies, might be because of a higher subglottal pressure or perhaps greater vocal tract contribution in SPL. Results from the present study suggest that trained subjects did not produce a significant higher SPL than untrained individuals by increasing the cost in terms of higher vocal fold collision and hence more impact stress. Future researches should explore the difference between trained and nontrained voices by aerodynamic measurements to evaluate the relationship between physiologic findings and the acoustic and EGG data. Moreover, further studies should consider both types of vocal tasks, sustained vowel and running speech, for both EGG and LTAS analysis. © 2013 The Voice Foundation.
Resumo:
Background The epidemiology and clinical features of brachioradial pruritus are variably described in the literature. We sought to analyze these features in a large group of Brazilian patients. Patients and Methods In a descriptive, observational study, we identified all patients with a final diagnosis of brachioradial pruritus seen over a one-year period and re-trospectively reviewed their records. The diagnosis was made after clinical-laboratory investigation had ruled out other causes of chronic pruritus. Demographic and clinical variables were collected along with pruritus characteristics, and analyzed using des-criptive statistics. Results Forty-three patients were identified; their mean age was 55.9 years, with predominance of women (81.4%) and Caucasians (86%). In 52%, the pruritus worsened with heat and sun exposure; 58.1% had intermittent complaints; the ice-pack sign was present only in 20.9%. The arms involving dermatomes C5-C6-C7-C8 (62.8%) were the most affected sites, while psychoactive drugs were the most frequently prescribed therapy. Conclusions Although uncommon, brachioradial pruritus should not be neglected in dermatological diagnosis. This case series analysis indicated that Brazilian patients from a tropical climate show characteristics similar to those described in other series from more temperate regions. © Blackwell Verlag GmbH, Berlin.
Resumo:
Background: Dendropsophus is a monophyletic anuran genus with a diploid number of 30 chromosomes as an important synapomorphy. However, the internal phylogenetic relationships of this genus are poorly understood. Interestingly, an intriguing interspecific variation in the telocentric chromosome number has been useful in species identification. To address certain uncertainties related to one of the species groups of Dendropsophus, the D. microcephalus group, we carried out a cytogenetic analysis combined with phylogenetic inferences based on mitochondrial sequences, which aimed to aid in the analysis of chromosomal characters. Populations of Dendropsophus nanus, Dendropsophus walfordi, Dendropsophus sanborni, Dendropsophus jimi and Dendropsophus elianeae, ranging from the extreme south to the north of Brazil, were cytogenetically compared. A mitochondrial region of the ribosomal 12S gene from these populations, as well as from 30 other species of Dendropsophus, was used for the phylogenetic inferences. Phylogenetic relationships were inferred using maximum parsimony and Bayesian analyses.Results: The species D. nanus and D. walfordi exhibited identical karyotypes (2n = 30; FN = 52), with four pairs of telocentric chromosomes and a NOR located on metacentric chromosome pair 13. In all of the phylogenetic hypotheses, the paraphyly of D. nanus and D. walfordi was inferred. D. sanborni from Botucatu-SP and Torres-RS showed the same karyotype as D. jimi, with 5 pairs of telocentric chromosomes (2n = 30; FN = 50) and a terminal NOR in the long arm of the telocentric chromosome pair 12. Despite their karyotypic similarity, these species were not found to compose a monophyletic group. Finally, the phylogenetic and cytogenetic analyses did not cluster the specimens of D. elianeae according to their geographical occurrence or recognized morphotypes.Conclusions: We suggest that a taxonomic revision of the taxa D. nanus and D. walfordi is quite necessary. We also observe that the number of telocentric chromosomes is useful to distinguish among valid species in some cases, although it is unchanged in species that are not necessarily closely related phylogenetically. Therefore, inferences based on this chromosomal character must be made with caution; a proper evolutionary analysis of the karyotypic variation in Dendropsophus depends on further characterization of the telocentric chromosomes found in this group. © 2013 Medeiros et al.; licensee BioMed Central Ltd.
Resumo:
Incluye Bibliografía
Resumo:
Includes bibliography
Resumo:
Los temas que se incluiran en un estudio comparativo sobre la fecundidad en algunos paises latinoamericanos, basado en los resultados de la Encuesta Mundial de Fecundidad, se describen junto con las variables y las categorias adoptadas. Los niveles y tendencias de la fecundidad se hallan adecuadamente descritos por la tasa global de fecundidad en los anos previos a la encuesta. Los diferenciales socio-economicos mas importantes serian la magnitud de la localidad de residencia, la educacion de ambos conyuges, la situacion ocupacional del marido, la participacion de la mujer en la actividad economica y la movilidad geografica. Variables importantes para determinar la formacion de la familia es la nupcialidad (numero y duracion de las uniones y edad a la primera union) y duracion de los intervalos intergenesicos, que a su vez pueden variar segun el tipo de resultados del embarazo y del empleo de planificacion familiar. El deseo de tener mas hijos juega un papel importante en ultima instancia en la determinacion del comportamiento reproductivo.
Resumo:
El estudio proporciona un análisis de las percepciones de los gobiernos sobre la situación demográfica y de las políticas gubernamentales implementadas por los países de América Latina y el Caribe en el campo de la población. El énfasis se sitúa en el crecimiento demográfico, a nivel de la mortalidad y acceso a servicios anticonceptivos. Previo la descripción de la situación regional , el análisis releva la evolución de las percepciones y políticas entre 1980 y 1991, incluyendo una discusión detenida tanto de las variables objeto de políticas como de la demografía de los países de la región.