942 resultados para oscillatory breathing
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Techniques of mind & body control seem to benefit human organism in general and cognition in particular, because they involve a mindfulness practice. However, there is still a scarcity of studies with well-controlled methods to investigate the possible effects of Yoga practice. In this study, we investigated the effects of regular Yoga practice, based on Yoga postures (asanas), breathing techniques, and meditation exercises, on memory and physiologic and psychological parameters related to quality of life. There were significant improvements on performance tasks of short term memory and long term memory. We also observed significant beneficial effects on psychological and physiological parameters such as mood, anxiety, depression, stress, and modulation of the autonomic nervous system in Yoga practitioners group compared to the conventional physical exercises group. The results suggest the possible influences of stress, emotional state and mental training on cognitive effects of yoga practice. Our results support the indication of practice of Yoga for the treatment or prevention of stress, psychological disorders and their possible cognitive consequences
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics, Guiana dolphin groups frequently changed their composition, modifying their patterns of spatial grouping and cohesion every 20 minutes on average. More than 50% of the individuals maintained a distance of up to 2 m from other group members and new individuals were attracted to the group, especially during feeding, leaving it for foraging. Large groups were more unstable than small, while groups containing only adults were more stable than groups of adults and juveniles. According to the Z-score analysis to investigate the sequence and behavioral routine, lone individuals were more ! .7! ! involved in foraging and feeding, while resting was more common in groups. Foraging and feeding were more common in homogeneous groups (individuals of the same age class), while heterogeneous groups (different age classes) were often involved in socialization, displaying a broader behavioral repertoire. Foraging and resting behavior presented higher stability (continuous duration in minutes) than the other behaviors. The analysis of breathing intervals in synchronized groups showed significant differences depending on type of behavior, composition and area preference. During resting, breathing intervals were of longer duration, and groups with calves showed shorter breathing intervals than groups without calves. Lone individuals also preferred areas called corral , often used for the entrapment of fishes. The Markov chain analysis revealed behavioral changes in the presence of boats, according to the type of group composition. Groups composed of adults presented decreased resting and increased in traveling during the presence of boats. Groups of adults and juveniles showed a massive reduction of socialization, while the behavior transition probability traveling-traveling was higher in groups of adults and calves. In the presence of the boats, stability of resting was reduced by one third of its original duration and traveling more than doubled. The behavioral patterns analyzed are discussed in light of socio-ecological models concerning costs and benefits of proximity between individuals and behavioral optimization. Furthermore, significant changes in behavioral patterns indicate that Guiana dolphins, at Pipa Beach, have suffered the effects of tourism as a result of violation of rules of conduct established for the study area
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Fretting fatigue occurs when the contact surfaces of two components undergo small oscillatory movement while they are subjected to a clamping force. A cyclic external load gives rise to the early initiation of fatigue cracks, thus reducing their service life. In this paper, the fretting fatigue behaviour of commercially pure titanium flat samples (1.5 mm thick) is evaluated. A fretting device composed of a frame, load cell, and two screw-mounted cylindrical fretting pads with convex extremities was built and set to a servo-hydraulic testing machine. The fatigue tests were conducted under load control at a frequency of 10 Hz and stress ratio R = 0.1, with various contact load values applied to the fretting pads. Additional tests under inert environment allowed assessing the role of oxidation on the wear debris formation. The fracture surfaces and fretting scars were analysed via scanning electron microscopy in order to evaluate the surface damage evolution and its effect on the fatigue crack features. The effect of the fretting condition on the S-N curve of the material in the range of 10(4)-10(6) cycles is described. Fatigue crack growth calculations allowed estimating the crack initiation and propagation lives under fretting conditions. The effect of the fretting condition in fatigue life is stronger for the lower values of cyclic stress and does not seem to depend on the contact loading value.
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Synchronism is the efetivation of the same behavior at the same time by two or more individuals. In cetology only from 2000 we verify an increasing of efforts for studies of synchronic behaviors. The synchronism in cetaceans was reported for a variety of contexts, including feeding, socializing, parental care, while resting, traveling and play, during afilliation, in sexual behaviour and possible while teaching. The synchronism in behavior is influenced by environmental factors and can be modified during stress situations such as the presence of boats. The aim of this study is to explore behavior synchronism presented by the estuarine dolphin (Sotalia guianensis) in Pipa, Rio Grande do Norte state, Northeastern Brazil. A total of 414 hours of observation during the year 2006, using scan sampling method, from a land based sighting was conducted. Analyses were conducted in four steps. Firstly, we determined the pattern of activity of the groups within the bay, testing for the influence of bay configuration before and after rains periods on the activity of animals. Analyses show that forage occurs more frequently after the rainy period, but there was no change in the number of individuals or spatial cohesions between them. Secondly, we analysed the influence of turism boat traffic on the behavior of animals. We verified no changes on the bahavior of animals during the presence of boats. Finally, we tested seven hypotheses regarding the ecological and social dynamics of synchronic behavior. Environmental aspects were considered the main influence for the synchronism, no influences of age, and more selective exihibition of synchronic breathing in feeding and social displays were observed during the study period
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This paper presents a hybrid way mixing time and frequency domain for transmission lines modelling. The proposed methodology handles steady fundamental signal mixed with fast and slow transients, including impulsive and oscillatory behaviour. A transmission line model is developed based on lumped elements representation and state-space techniques. The proposed methodology represents an easy and practical procedure to model a three-phase transmission line directly in time domain, without the explicit use of inverse transforms. The proposed methodology takes into account the frequency-dependent parameters of the line, considering the soil and skin effects. In order to include this effect in the state matrices, a fitting method is applied. Furthermore the accuracy of proposed the developed model is verified, in frequency domain, by a simple methodology based on line distributed parameters and transfer function related to the input/output signals of the lumped parameters representation. In addition, this article proposes the use of a fast and robust analytic integration procedure to solve the state equations, enabling transient and steady-state simulations. The results are compared with those obtained by the commercial software Microtran (EMTP), taking into account a three-phase transmission line, typical in the Brazilian transmission system.
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This article shows a transmission line model for simulation of fast and slow transients, applied to symmetrical or asymmetrical configurations. A transmission line model is developed based on lumped elements representation and state-space techniques. The proposed methodology represents a practical procedure to model three-phase transmission lines directly in time domain, without the explicit or implicit use of inverse transforms. In three-phase representation, analysis modal techniques are applied to decouple the phases in their respective propagation modes, using a correction procedure to set a real and constant matrix for untransposed lines with or without vertical symmetry plane. The proposed methodology takes into account the frequency-dependent parameters of the line and in order to include this effect in the state matrices, a fitting procedure is applied. To verify the accuracy of the proposed state-space model in frequency domain, a simple methodology is described based on line distributed parameters and transfer function associated with input/output signals of the lumped parameters representation. In addition, this article proposes the use of a fast and robust integration procedure to solve the state equations, enabling transient and steady-state simulations. The results obtained by the proposed methodology are compared with several established transmission line models in EMTP, taking into account an asymmetrical three-phase transmission line. The principal contribution of the proposed methodology is to handle a steady fundamental signal mixed with fast and slow transients, including impulsive and oscillatory behavior, by a practical procedure applied directly in time domain for symmetrical or asymmetrical representations. (C) 2011 Elsevier Ltd. All rights reserved.
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A diminuição da densidade mineral óssea das vértebras, própria do processo de envelhecimento e que pode ser agravada pela osteoporose, determina uma diminuição da região anterior dos corpos vertebrais, resultando em compressão e colapso dessas vértebras, com maior estreitamento dos discos e espaços intervertebrais. Essas novas condições interferem no funcionamento normal de órgãos e sistemas do organismo. O objetivo foi avaliar o grau de cifose torácica e a capacidade funcional de mulheres idosas com e sem osteoporose. Foram avaliadas 30 idosas ativas fisicamente, sendo 20 sem osteoporose ( GSO: 65,1± 4,67 anos) e 10 idosas com osteoporose (GCO: 68,6± 6,46anos). Foram avaliados a medida da cifose torácica, teste de caminhada de seis minutos (TC6'), Timed Up and go (TUG) e força dos músculos respiratórios (PImáx e PEmáx). Os dados obtidos foram analisados utilizando o teste t de Student. O nível de significância utilizado foi de 5% (α£ 0,05). Houve diferença significativa entre os grupos sem (GSO) e com osteoporose (GCO) somente no TC6'(GSO: 426,63±46,36 m; GCO: 392,64±36,68 m , α =0,02). As outras variáveis analisadas não apresentaram diferença significativa (Cifose torácica: α = 0,17; TUG: α =0,49; PImax: α =0,45; PEmax: α =0,19). A osteoporose não influenciou o grau de cifose torácica, a força dos músculos respiratórios e mobilidade das idosas. Entretanto, o desempenho no TC6' foi influenciado negativamente pela osteoporose.
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TEMA: medidas da dinâmica respiratória são freqüentemente utilizadas na clínica fonoaudiológica, mas poucos são os dados científicos destas na população infantil. OBJETIVO: estudar a dinâmica respiratória entre crianças que respiram pelo modo nasal. MÉTODO: o estudo foi realizado com uma amostra aleatória estratificada de 106 crianças respiradoras nasais de escolas da cidade de Marília / SP, entre quatro e dez anos de ambos os sexos. Foram realizadas as medidas de capacidade vital (CV), nas posições em pé e sentada, com e sem oclusão nasal; de tempo máximo de fonação (TMF) de vogais e consoantes sustentadas, além de fala em seqüência com a contagem de números. RESULTADOS: a medida média da CV na posição em pé com e sem oclusão nasal foi 1515,56 ml e 1538,67 ml respectivamente e na posição sentada, 1524 ml e 1539,15 ml respectivamente; o TMF das vogais em segundos foi: /a/ = 8,32 , /i/ = 8,61 e /u/ 8,42; o de consoantes foi: /s/ = 6,64 e /z/ = 7,65 e o de seqüência de números foi de 7,76 segundos. Resultados: observou-se que o tempo médio destas medidas aumentou progressivamente conforme as faixas etárias. Tanto para o TMF das vogais como, para o das consoantes, houve diferença estatística significante (p < 0,05) nas idades mais distantes, ou seja, entre quatro e dez anos, quatro e nove, e quatro e oito anos. em faixas etárias consecutivas não houve diferença estatística significante nos valores de CV. Houve forte associação entre a CV e o crescimento físico da criança. CONCLUSÃO: esse estudo mostrou medidas de dinâmica respiratória em crianças que podem ser úteis no diagnóstico e terapia fonoaudiológica. Outras pesquisas deveriam ser desenvolvidas para adicionais informações sobre o assunto.
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Objective To compare the cardiorespiratory effects and incidence of gastroesophageal reflux with the use of a laryngeal mask airway (LMA) or endotracheal tube (ET) in anesthetized cats during spontaneous (SV) or controlled ventilation (CV).Study design Prospective randomized experimental trial.Animals Thirty-two adult crossbred cats, weighing 2.7 +/- 0.4 kg.Methods the cats were sedated with intramuscular (IM) methotrimeprazine (0.5 mg kg(-1)) and buprenorphine (0.005 mg kg(-1)), followed 30 minutes later by induction of anesthesia with intravenous (IV) thiopental (12.5-20 mg kg(-1)). An ET was used in 16 cats and an LMA in the remaining 16 animals. Anesthesia was maintained with 0.5 minimum alveolar concentration (0.6%) of halothane in oxygen using a Mapleson D breathing system. Cats in both groups were further divided into two equal groups (n = 8), undergoing either SV or CV. Neuromuscular blockade with pancuronium (0.06 mg kg(-1)) was used to facilitate CV. Heart and respiratory rates, direct arterial blood pressure, capnometry (PE'CO2) and arterial blood gases were measured. Gastric reflux and possible aspiration was investigated by intragastric administration of 5 mL of radiographic contrast immediately after induction of anesthesia. Cervical and thoracic radiographs were taken at the end of anesthesia. Data were analyzed using ANOVA followed by Student-Newman-Keuls, Kruskal-Wallis or Friedman test where appropriate.Results Values for PaCO2 and PE'CO2 were higher in spontaneously breathing cats with the LMA when compared with other groups. Values of PaO2 and hemoglobin oxygen saturation did not differ between groups. Gastroesophageal reflux occurred in four of eight and two of eight cats undergoing CV with ET or LMA, respectively. There was no tracheal or pulmonary aspiration in any cases.Conclusions and clinical relevance the use of an LMA may be used as an alternative to endotracheal intubation in anesthetized cats. Although aspiration was not observed, gastric reflux may occur in mechanically ventilated animals.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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OBJETIVO: Avaliar o efeito da utilização de um programa de treinamento específico dos músculos respiratórios sobre a função pulmonar em indivíduos tabagistas. MÉTODOS: Foram estudados 50 indivíduos tabagistas assintomáticos com idade superior a 30 anos, nos seguintes momentos: A0 - avaliação inicial seguida do protocolo de exercícios respiratórios; A1 - reavaliação após 10 minutos da aplicação do protocolo; e A2 -reavaliação final após duas semanas de treinamento utilizando o mesmo protocolo três vezes por semana. A avaliação foi realizada através das medidas de pressões respiratórias máximas (PImax. e PEmax.), picos de fluxo respiratórios (PFI e PFE), ventilação voluntária máxima (VVM), capacidade vital Forçada (CVF) e Volume expiratório forçado no primeiro segundo (VEF1). RESULTADOS: Não houve melhora na CVF e VEF1 da avaliação inicial para a final. Houve aumento significativo das variáveis PFI, PFE, VVM e PImax nas avaliações A1 e A2. A variável PEmax. aumentou somente na avaliação A2. CONCLUSÃO: A aplicação de protocolo de exercícios respiratórios com e sem carga adicional em indivíduos tabagistas produziu melhora imediata na performance dos músculos respiratórios, mas esta melhora foi mais acentuada após duas semanas de exercício.
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Aim. This study aimed at assessing the accuracy of ultrasound (US) in the diagnosis of recent deep vein thrombosis (DVT) in an experimental study in dogs.Methods. Design: blinded and randomized experimental study. Twenty dogs were randomly divided in two groups: control group (CG) and thrombosis group (TG). US was performed in the pre- and postoperative period. Phlebography was performed immediately prior to the postoperative US. After the second US, a surgery was performed to detect whether thrombus was present or not. US results were compared to those of phlebography and surgical findings.Results. in all dogs, inferior vena cava (IVC) was compressible. The relations of IVC diameter with the aorta were higher (P<0.005) in TG than in CG. Spectral Doppler in spontaneous breathing, tissue harmonic imaging, power Doppler and B flow showed sensitivity, specificity and accuracy of 1. Phlebography presented sensitivity of 90%, specificity of 80% and accuracy of 85%, when compared to surgical finding.Conclusion. For the diagnosis of recent DVT in the experimental model used, venous compressibility proved to be inefficient. The ratio of WC diameter to aorta, when increased, suggests thrombosis. The use of new US technological advances increases accuracy. Phlebography was less accurate than US.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)