82 resultados para Seleção Variáveis Observadas
Resumo:
Demand for organic foods within in Brazil are growing, characterizing itself for if constituting in a new strategical segment of commercialization. In this context, the objective of this research was to investigate the variables used by consumers in the purchase decision of organic products, aiming to characterize the level of competitiveness of these products, assisting in the creation of environmental strategies for the development of the activity and contributing in the increment of the knowledge about the subject, that can assist it in the increase of the commercialization and the consumption of these foods. From data collected in the city of Natal/RN, it was used a survey research, of exploratory and descriptive character. The sample was obtained using 401 questionnaires, in which was realized: the Test of Comparison of Averages, Descriptive analysis, analysis of Cluster and Qui-square. The results found in this study indicate that the main reasons for the organic food purchase are the absence of chemical pesticides in the product, followed by the care with own health and of the household. The main characteristics in the consumers of supermarkets, that are associates with purchase frequency of organic foods are the environmental behavior and lifestyle. Among the profile characteristics, gender, age and number of children are associates with the purchase frequency of these foods and the income and level education not showed association
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With the rapid growth of databases of various types (text, multimedia, etc..), There exist a need to propose methods for ordering, access and retrieve data in a simple and fast way. The images databases, in addition to these needs, require a representation of the images so that the semantic content characteristics are considered. Accordingly, several proposals such as the textual annotations based retrieval has been made. In the annotations approach, the recovery is based on the comparison between the textual description that a user can make of images and descriptions of the images stored in database. Among its drawbacks, it is noted that the textual description is very dependent on the observer, in addition to the computational effort required to describe all the images in database. Another approach is the content based image retrieval - CBIR, where each image is represented by low-level features such as: color, shape, texture, etc. In this sense, the results in the area of CBIR has been very promising. However, the representation of the images semantic by low-level features is an open problem. New algorithms for the extraction of features as well as new methods of indexing have been proposed in the literature. However, these algorithms become increasingly complex. So, doing an analysis, it is natural to ask whether there is a relationship between semantics and low-level features extracted in an image? and if there is a relationship, which descriptors better represent the semantic? which leads us to a new question: how to use descriptors to represent the content of the images?. The work presented in this thesis, proposes a method to analyze the relationship between low-level descriptors and semantics in an attempt to answer the questions before. Still, it was observed that there are three possibilities of indexing images: Using composed characteristic vectors, using parallel and independent index structures (for each descriptor or set of them) and using characteristic vectors sorted in sequential order. Thus, the first two forms have been widely studied and applied in literature, but there were no records of the third way has even been explored. So this thesis also proposes to index using a sequential structure of descriptors and also the order of these descriptors should be based on the relationship that exists between each descriptor and semantics of the users. Finally, the proposed index in this thesis revealed better than the traditional approachs and yet, was showed experimentally that the order in this sequence is important and there is a direct relationship between this order and the relationship of low-level descriptors with the semantics of the users
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Visual attention is a very important task in autonomous robotics, but, because of its complexity, the processing time required is significant. We propose an architecture for feature selection using foveated images that is guided by visual attention tasks and that reduces the processing time required to perform these tasks. Our system can be applied in bottom-up or top-down visual attention. The foveated model determines which scales are to be used on the feature extraction algorithm. The system is able to discard features that are not extremely necessary for the tasks, thus, reducing the processing time. If the fovea is correctly placed, then it is possible to reduce the processing time without compromising the quality of the tasks outputs. The distance of the fovea from the object is also analyzed. If the visual system loses the tracking in top-down attention, basic strategies of fovea placement can be applied. Experiments have shown that it is possible to reduce up to 60% the processing time with this approach. To validate the method, we tested it with the feature algorithm known as Speeded Up Robust Features (SURF), one of the most efficient approaches for feature extraction. With the proposed architecture, we can accomplish real time requirements of robotics vision, mainly to be applied in autonomous robotics
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The limits to inform is about the character stico of basic, quimica, mineralogical and mechaniques of matlaughed material used in the manufacturing process the product certified in economic region the Cariri, specifically in the city of Crato, Ceará state, motivated the development of this work, since in this region the exist ing economic context that a general appear as important in the production chains. Were made twentyfive soils-test specimen collection and the study was performed to differentiate the mat laugh materials of variaveis processing of mathing raw materials in the factory The product mica monkeys by extrusion and pressing. The results were obtained ap s as analyzes: grain size, index of plasticity, fluoresce incidence X-ray difration the X-ray, and analyzes thermicals and properties technological. through s of curves gresifica returned to was a comparison between the retro the linear, absorb to water, porosity and bulk density. the results show that the excellent distribution and character acceptable available for the processing of the structure color dark red. needing, therefore, of the mixture of a less plastic clay with thick granulation, that works as plasticity reducer. In spite of the different resignation forms for prensagem and extrusion, the characteristics of absorption of water and rupture tension the flexing was shown inside of the patterns of ABNT
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Among the main challenges in the beer industrial production is the market supply at the lowest cost and high quality, in order to ensure the expectations of customers and. consumers The beer fermentation stage represents approximately 70% of the whole time necessary to its production, having a obligatoriness of strict process controls to avoid becoming bottleneck in beer production. This stage is responsible for the formation of a series of subproducts, which are responsible for the composition of aroma/bouquet existing in beer and some of these subproducts, if produced in larger quantities, they will confer unpleasant taste and odor to the final product. Among the subproducts formed during the fermentation stage, total vicinal diketones is the main component, since it is limiting for product transfusion to the subsequent steps, besides having a low perception threshold by the consumer and giving undesirable taste and odor. Due to the instability of main raw materials quality and also process controls during fermentation, the development of alternative forms of beer production without impacting on total fermentation time and final product quality is a great challenge to breweries. In this work, a prior acidification of the pasty yeast was carried out, utilizing for that phosphoric acid, food grade, reducing yeast pH of about 5.30 to 2.20 and altering its characteristic from flocculent to pulverulent during beer fermentation. An increase of six times was observed in amount of yeast cells in suspension in the second fermentation stage regarding to fermentations by yeast with no prior acidification. With alteration on two input variables, temperature curve and cell multiplication, which goal was to minimize the maximum values for diketones detected in the fermenter tank, a reduction was obtained from peak of formed diacetyl and consequently contributed to reduction in fermentation time and total process time. Several experiments were performed with those process changes in order to verify the influence on the total fermentation time and total vicinal diketones concentration at the end of fermentation. This experiment reached as the best production result a total fermentation time of 151 hours and total vicinal diketone concentration of 0.08 ppm. The mass of yeast in suspension in the second phase of fermentation increased from 2.45 x 106 to 16.38 x 106 cells/mL of yeast, which fact is key to a greater efficiency in reducing total vicinal diketones existing in the medium, confirming that the prior yeast acidification, as well as the control of temperature and yeast cell multiplication in fermentative process enhances the performance of diketones reduction and consequently reduce the total fermentation time with diketones concentration below the expected value (Max: 0.10 ppm)
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Environmental sustainability has become one of the topics of greatest interest in industry, mainly due to effluent generation. Phenols are found in many industries effluents, these industries might be refineries, coal processing, pharmaceutical, plastics, paints and paper and pulp industries. Because phenolic compounds are toxic to humans and aquatic organisms, Federal Resolution CONAMA No. 430 of 13.05.2011 limits the maximum content of phenols, in 0.5 mg.L-1, for release in freshwater bodies. In the effluents treatment, the liquid-liquid extraction process is the most economical for the phenol recovery, because consumes little energy, but in most cases implements an organic solvent, and the use of it can cause some environmental problems due to the high toxicity of this compound. Because of this, exists a need for new methodologies, which aims to replace these solvents for biodegradable ones. Some literature studies demonstrate the feasibility of phenolic compounds removing from aqueous effluents, by biodegradable solvents. In this extraction kind called "Cloud Point Extraction" is used a nonionic surfactant as extracting agent of phenolic compounds. In order to optimize the phenol extraction process, this paper studies the mathematical modeling and optimization of extraction parameters and investigates the effect of the independent variables in the process. A 32 full factorial design has been done with operating temperature and surfactant concentration as independent variables and, parameters extraction: Volumetric fraction of coacervate phase, surfactant and residual concentration of phenol in dilute phase after separation phase and phenol extraction efficiency, as dependent variables. To achieve the objectives presented before, the work was carried out in five steps: (i) selection of some literature data, (ii) use of Box-Behnken model to find out mathematical models that describes the process of phenol extraction, (iii) Data analysis were performed using STATISTICA 7.0 and the analysis of variance was used to assess the model significance and prediction (iv) models optimization using the response surface method (v) Mathematical models validation using additional measures, from samples different from the ones used to construct the model. The results showed that the mathematical models found are able to calculate the effect of the surfactant concentration and the operating temperature in each extraction parameter studied, respecting the boundaries used. The models optimization allowed the achievement of consistent and applicable results in a simple and quick way leading to high efficiency in process operation.
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Drying of fruit pulps in spouted beds of inert particles has been indicated as a viable technique to produce fruit powders. Most of the processes employed to produce dried fruit pulps and juices, such as Foam Mat, encapsulation by co-crystallization and spray drying utilize adjuvant and additives (such as thickeners, coating materials, emulsifiers, acidulants, flavors and dyes), which is not always desirable. The fruit pulp composition exerts an important effect on the fruit powder production using a spouted bed. In the study by Medeiros (2001) it was concluded that lipids, starch and pectin contents play an important role on the process performance, enhancing the powder production; however, the drying of fruit pulps containing high content of reducing sugars (glucose and fructose) is practically unviable. This work has the objective of expanding the studies on drying of fruit pulps in spouted bed with aid of adjuvant (lipids, starch and pectin) aiming to enhance the dryer performance without jeopardizing the sensorial quality of the product. The optimum composition obtained by Medeiros (2001) was the basis for preparing the mixtures of pulps. The mixture formulations included pulps of mango (Mangifera indica), umbu (Spondias tuberosa) and red mombin (Spondia purpurea) with addition of cornstarch, pectin and lipids. Different products were used as lipids source: olive and Brazil nut oils, coconut milk, heavy milk, powder of palm fat and palm olein. First of all, experiments were conducted to define the best formulation of the fruit pulps mixture. This definition was based on the drying performance obtained for each mixture and on the sensorial characteristics of the dry powder. The mixture formulations were submitted to drying at fixed operating conditions of drying and atomizing air flow rate, load of inert particles, temperature and flow rate of the mixture. The best results were obtained with the compositions having powder of palm fat and palm olein in terms of the drying performance and sensorial analysis. Physical and physicochemical characteristics were determined for the dry powders obtained from the mixtures formulations. Solubility and reconstitution time as well as the properties of the product after reconstitution were also evaluated. According to these analyses, the powder from the mixtures formulations presented similar characteristics and compatible quality to those produced in other types of dryers. Considering that the palm olein is produced in Brazil and that it has been used in the food industry substituting the palm fat powder, further studies on drying performance were conducted with the composition that included the palm olein. A complete factorial design of experiments 23, with three repetitions at the central point was conducted to evaluate the effects of the air temperature, feeding flow rate and intermittence time on the responses related to the process performance (powder collection efficiency, material retained in the bed and angle of repose of the inert particles after the process) and to the product quality (mean moisture content, loss of vitamin C and solubility). Powder production was uniform for the majority of the experiments and the higher efficiency with lower retention in the bed (59.2% and 1.8g, respectively) were obtained for the air temperature of 80°C, mixture feed rate of 5ml/min in intervals of 10 min. The statistical analysis of the results showed that the process variables had individual or combined significant influences on the powder collection efficiency, material retention in the bed, powder moisture content and loss of vitamin C. At the experimental ranges of this work, the angle of repose and solubility were not influenced by the operating variables. From the results of the experimental design, statistical models were obtained for the powder moisture content and loss of vitamin C
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The aquatic ecosystems can play a role as carbon-dioxide-source or carbon-dioxide-sink systems due to the high predominance of heterotrophic or autotrophic metabolism. The primary production can strongly affect the carbon balance (CO2) through the consumption of carbon dioxide in the photosynthesis, especially in eutrophic environment, acting as a carbon sink. The present study tested the hypothesis that the eutrophic reservoirs in tropical semi-arid region are carbon dioxide-sink systems due to the high primary productivity presented in these systems. Five Brazilian reservoirs from the semi-arid in the northeast region were monitored monthly during four years (2010 to 2013) with a prolonged drought event identified during the study. The results showed an increasing level of eutrophication over the period of prolonged drought, with the predominance of autotrophy. Significant negative correlations were observed between the partial pressure of CO2 (pCO2) (p<0,001) and chlorophyll-a in the Boqueirão, Passagem das Traíras, Dourado and Gargalheiras reservoirs, showing a pattern of the carbon dioxide-sink systems. However, this pattern was not found in Cruzeta reservoir. In summary, in the tropical semi-arid region, hydrological and morphometric variables can lead to different behaviors of the water-supply reservoirs on the carbon metabolism. The eutrophic reservoirs evaluated showed a negative relationship between pCO2 and Chl-a, which suggests that these water bodies show an autotrophic metabolism and behave as carbon dioxide- sink systems
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A rotação estelar é um dos mais importantes observáveis da evolução estelar. Neste sentido, o satélite CoRoT representa uma oportunidade única de medir os períodos rotacionais para uma amostra de estrelas estatisticamente robusta, oferecendo dados absolutamente necessários para o estudo da rotação e seu papel na evolução estelar. Para conseguir isto, um passo fundamental é a caracterização física e química das estrelas observadas pelo CoRoT, especificamente devido ao fato de que o cálculo de períodos rotacionais confiáveis é um trabalho difícil sem a ajuda dos parâmetros estelares. Desta forma, foi elaborado um importante seguimento observacional das estrelas nos campos do CoRoT do anticentro LRa01 e do centro LRc01, permitindo a correta identificação dos períodos que reflitam a modulação rotacional. Nesta tese de doutorado são apresentados os resultados de tal seguimento. Parâmetros físicos e químicos, tais como temperatura efetiva Teff , gravidade superficial log(g), velocidade de microturbulência Vmic, abundância de ferro [Fe/H], velocidade de rotação projetada Vsin(i), e abundância de lítio A(Li) são apresentados para uma amostra de 116 estrelas dos campos CoRoT. Elas se encontram em diferentes estágios evolutivos, desde a sequência principal (SP) até o ramo das gigantes vermelhas (GV). As observações foram feitas utilizando os espectrógrafos UVES (VLT) e HYDRA (CTIO). Para a derivação de tais parâmetros foram utilizados o programa TurboSpectrum e os modelos de atmosfera de MARCS. Paralelamente, velocidades rotacionais Vsin(i) foram obtidas a partir do ajuste dos perfis observados e sintéticos das linhas de ferro e por meio de uma calibração de função de correlação cruzada (CCF). Períodos rotacionais Prot para 77 estrelas da amostra foram obtidos a partir das curvas de luz do satélite CoRoT. Extensas tabelas destes parâmetros e seus respectivos erros são apresentadas. Foram encontradas diferenças nas distribuições de Teff , [Fe/H] e estágios evolutivos entre os diferentes campos do CoRoT, indicando possíveis efeitos de seleção na amostra, assim como a existência de diferentes populações estelares do disco Galáctico. Por outro lado, o comportamento rotacional e as abundâncias de lítio não apresentam diferenças entre estrelas de parâmetros físicos similares, mas que pertencem a diferentes campos do CoRoT. A partir da análise de temperaturas, foi encontrada uma maior extinção por avermelhamento para estrelas do CoRoT localizadas no campo LRc01, assim como um gradiente deste valor em função da distância. Os resultados mostram que as abundâncias de lítio, as velocidades de rotação e os períodos rotacionais apresentam o mesmo comportamento descrito na literatura. Por outro lado, é apresentada pela primeira vez a relação que existe entre o lítio e o período de rotação em diferentes estágios evolutivos, mostrando, tal como era esperado, que ambas as grandezas possuem uma anticorrelação. Também é apresentada a evolução simultânea da rotação e do lítio, e foram calculadas relações que permitem obter valores médios de A(Li) como função da temperatura efetiva e do período rotacional. Os dados apresentados nesta tese de doutorado representam um importante ponto de partida para serem utilizados como uma amostra de calibração para diferentes programas no contexto da missão do satélite CoRoT, uma vez que a lista de estrelas aqui analisadas são parte das mais brilhantes que compõem o campo Exo do CoRoT
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Morbidly obese patients present an increase in heart rate, blood pressure and perceived exertion besides lower walking ability compared to normal weight people. However, little is known about how these variables are presented after bariatric surgery. Moreover, despite the distance walked during the six-minute walk (6MWT) improve after surgery is not well established if the level of physical activity influences this improvement. Objective: To evaluate cardiovascular performance, perceived effort, ability of walking and physical activity level of patients with morbid obesity before and after bariatric surgery. Methods: The cardiovascular performance, perception of effort, the ability to walk and level of physical activity were assessed in 22 patients before (BMI = 50.4 kg/m2) and after (BMI = 34.8 kg/m2) bariatric surgery through the 6MWT. The heart rate, blood pressure and perceived exertion were assessed at rest, at the end of the 6MWT and in the second minute post-test (HR recovery). The ability to walk was measured by total distance walked at the end of the test while the level of physical activity was estimated by applying the Baecke questionnaire, analyzing domains occupation, leisure and locomotion and leisure and physical activity. Results: The HR at rest and recovery decreased significantly (91.2 ± 15.8 bpm vs. 71.9 ± 9.8 bpm, 99.5 ± 15.3 bpm vs 82.5 ± 11.1 bpm, respectively), as well as all the arterial pressure and perceived exertion after surgery. The distance achieved by the patients increased by 58.4 m (p = 0.001) postoperatively. Time postoperatively had correlation with the percentage of excess weight lost (r = 0.48, p = 0.02), BMI (r =- 0.68, p = 0.001) and the Baecke (r = 0.52, p = 0.01) which did not happen with the distance walked (r = 0.37, p = 0.09). Despite weight loss, patients showed no difference in the level of physical activity in any of the areas before and after surgery. Conclusion: The cardiovascular performance, the perception of effort and ability to walk seem to improve after bariatric surgery. However, despite improvement in the ability to walk by the distance achieved in the 6MWT after weight loss, this is not reflected in an increase in physical activity level of obese patients after surgery
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Objective: To compare the effects of the treadmill training with partial body-weight support (TPBWS) and Proprioceptive Neuromuscular Facilitation (PNF) method on gait of subjects with chronic stroke. Design: Quasi-experimental study. Setting: Laboratorial research. Participants: Twenty-three subjects (13 men and 10 women), with a mean age of 56,7 ± 8,0 years and a mean time since the onset of the stroke of 27,7 ± 20,3 months, and able to walk with personal assistance or assistive devices. Interventions: Two experimental groups underwent gait training based on PNF method (PNF group, n=11) or using the TPBWS - Gait Trainer System 2, Biodex, USA (TPBWS group, n=12), for three weekly sessions, during four weeks. Measures: Evaluation of motor function - using the Stroke Rehabilitation Assessment of Movement (STREAM) and the motor subscale of the Functional Independence Measure (motor FIM) -, and kinematic gait analyze with the Qualisys System (Qualisys Medical AB, Gothenburg, Sweden) were carried out before and after the interventions. Results: Increases in the STREAM scores (F=49.189, P<0.001) and in motor FIM scores (F=7.093, P=0.016), as well as improvement in symmetry ratio (F=7.729, P=0.012) were observed for both groups. Speed, stride length and double-support time showed no change after training. Differences between groups were observed only for the maximum ankle dorsiflexion over the swing phase (F=6.046, P=0.024), which showed an increase for the PNF group. Other angular parameters remain unchanged. Conclusion: Improvement in motor function and in gait symmetry was observed for both groups, suggesting similarity of interventions. The cost-effectiveness of each treatment should be considered for your choice
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Introduction: The frailty in the elderly is the result of a complex interplay between many social and clinical factors involved in its genesis. Although there is an understanding of its association with increased risk of adverse clinical outcomes, still it is unclear whether this syndrome can be aggravated due to lack of social support. So, the objective of this study was to analyze the association between social support and frailty syndrome in elderly community residents. Materials and methods: Observational analytical cross-sectional study, with a sample of 300 elderly living in the city of Natal-RN. Were collected informations about socialdemographic, economics and physical health data. The Social support was assessed by the status of cohabitation; marital status; contact frequency and diversity rate; received and given attendance frequency rate; and Map Minimum Relations of the Elderly. The frailty was assessed using the following criteria: unintentional weight loss, weakness, low physical activity, exhaustion and Slowness. To observe any possible associations, we performed the Pearson chi-square test, the Student t test and multivariate analysis using binary logistic regression, adopting a significance level of 5%. Results: It was observed that there were no associations of frailty with the social support variables, except for housekeeping mode (p = 0.046) of the MMRI. For the sociodemographic, economic, physical health and social support data, only age (p <0.001), sedentary lifestyle (p = 0.002) and poor perceived health (p = 0.001) were the ones that remained in the logistic regression model, with strong association for the presence of frailty. Conclusion: Among the variables related to social support, only to help with housekeeping was significantly associated with frailty. However, more studies need to be developed to characterize the social vulnerability, as well as health services need to recognize the importance of social support as an integral part of care for the elderly
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Among the therapeutic approaches that can be used to achieve this goal is the gait training on sloping surfaces, but there are few scientific findings that elucidate the results of this practice. OBJECTIVE: To evaluate the effects of training on sloping surfaces on the gait of subjects with chronic hemiparesis. MATERIALS AND METHODS: A controlled, randomized, blinded clinical trial was conducted. Concluded the study twenty-four subjects with age between 40 and 70 years (54,91±9,3). Their neurological function, functional independence, motor function and balance assessed, besides the gait evaluation through kinemetry. The subjects were allocated into two groups: control group (CG) underwent gait training on treadmill with partial body weight support (PBWS) without inclination; and the experimental group (EG) submitted to gait training on treadmill with PBWS and inclination of 10%. Twelve training sessions were performed. The paired t Student test and Wilcoxon test were used in statistical analysis to compare findings before and after training for each group, and the t student test for independent samples and Mann-Whitney.test were used to compare the to groups. RESULTS: After training within-group changes were observed on balance recovery, motor function and functionality, in both experimental conditions. The EG showed changes after training on speed, stride length, step length of paretic and non-paretic side, paretic single support, double support time and non-paretic swing time. The CG the differences were detected on double support, paretic single support and hip range of movement. The EG showed better results when compared to CG on the variables: speed (p=0,034), non-paretic single support (p=0,02) and paretic swing time (p=0,02). CONCLUSION: gait training on sloping surfaces represents a promising strategy for gait training of subjects with chronic hemiparesis since it is can influence a greater number of gait variables, when compared with gait training on flat surface
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Introduction: Falls among older adults is a public health problem, therefore it is necessary preventive actions, however the adherence is the major problem faced by practitioners and researchers working on falls prevention programs. Objective: To evaluate the variables related to the adherence to falls prevention programs among the elderly enrolled in a Basic Health Unit (BHU). Methods: Was performed an observational cross-sectional analytical study. All elderly registered in a BHU and able to ambulate independently were invited to participate in a falls prevent program. The Elderly who Adhered to the Program (EAP) were evaluated at BHU; and the Elderly Not Adhered to the Program (ENAP) were identified and assessed at home. The assessment for both groups was performed using an evaluation form containing personal data, measures and clinical scales to assess cognitive status, balance, mobility, fear of falling, handgrip strength. Data were analyzed with SPSS 20.0. In addition to this assessment, the ENAP underwent a semi structured interview, in which we used the qualitative approach based on the figure of the Collective Subject Discourse. Results: The study included 222 elderly, 111 EAP and 111ENAP, most aged between 70 and 79 years (48.2%), female (68.5%), married (52.3%) and illiterate (47.7%). Consolidated as protective factors for adherence, worst rates of physical activity (p = 0.001), balance (p = 0.010) and cognition (p = 0.007). The interview of ENAP identified two themes: "Local implementation of programs for the prevention of falls" and "Relationship between BHU and the elderly health care," and found that the elderly who did not adhere were unable to displace and did not mention that primary care programs are related to health care in elderly. Conclusions: Elderly who do not adhere to the program differ from elderly who adhere as worst indices of cognition, balance and physical activity which implies greater risk of falling; and they were unable to participate in falls prevention program and by to be caregiver and showed displacement difficult
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Introdução: A asma se tornou um problema de saúde pública devido aos seus grandes custos em cuidados de saúde. Os exercícios respiratórios constituem uma intervenção não farmacológica de baixo custo e baixo risco que vem sendo utilizada por fisioterapeutas em diferentes países no tratamento de pacientes asmáticos. Objetivo: Avaliar a eficácia dos exercícios respiratórios no tratamento de pacientes adultos com asma nos seguintes desfechos: qualidade de vida, sintomas da asma, número de exacerbações agudas, episódios de hospitalização, mensurações fisiológicas (função pulmonar e capacidade funcional), número de consultas médicas, número de faltas no trabalho devido a exacerbações da doença, avaliação subjetiva do paciente em relação à intervenção. Método: Revisão sistemática de estudos controlados randomizados com metanálise realizada em parceria com a Colaboração Cochrane. As seguintes bases de dados foram consultadas: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED, e PsycINFO, além de busca manual em revistas da área e em resumos de congressos. Os seguintes termos foram utilizados: (breath*) and (exercise* or retrain* or train* or re-educat* or educat* or physiotherap* or "physical therap*" or "respiratory therapy" or buteyko ). As listas de referências dos estudos selecionados e registros de ensaios clínicos também foram consultados. A seleção dos estudos e a avaliação do risco de viés dos estudos incluídos foram realizadas de maneira independente por dois revisores. O software Review Manager foi utilizado para análise dos dados, no qual o modelo de efeito fixo foi utilizado. As variáveis contínuas foram expressas como diferença de média ponderada com um intervalo de confiança de 95%. A heterogeneidade dos resultados dos estudos incluídos foi realizada por meio da análise dos Forest plots. O teste qui-quadrado (Chi2) com um P valor de 0.10 foi utilizado para indicar significância estatística. O Índice de heterogeneidade (I2) foi implementado com um valor acima de 50% como um nível substancial de heterogeneidade. Resultados: 13 estudos envolvendo 906 pacientes estão atualmente incluídos na revisão. Os seguintes desfechos foram mensurados pelos estudos incluídos: qualidade de vida, sintomas da asma, número de exacerbações agudas e função pulmonar. Os estudos relataram uma melhora na qualidade de vida, sintomas da asma e número de exacerbações agudas. Seis dos onze estudos que avaliaram função pulmonar mostraram uma diferença significativa favorável aos exercícios respiratórios. Não houve relato de efeitos adversos. Devido à heterogeneidade substancial encontrada entre os estudos, metanálise foi possível apenas para sintomas da asma, a qual incluiu dois estudos e mostrou uma diferença significativa favorável aos exercícios respiratórios. A avaliação do risco de viés foi prejudicada devido ao relato incompleto de aspectos metodológicos pela maioria dos estudos incluídos. Conclusão: Embora os resultados encontrados pelos estudos incluídos demonstraram individualmente que os exercícios respiratórios podem ser importantes no tratamento da asma, não há evidência conclusiva nesta revisão para suportar ou refutar a eficácia desta intervenção no tratamento de pacientes asmáticos. Este fato foi devido às diferenças metodológicas entre os estudos incluídos e à ausência de relato de aspectos metodológicos por parte da maioria dos estudos incluídos. Não há dados disponíveis em relação aos efeitos dos exercícios respiratórios nos seguintes desfechos: episódios de hospitalização, número de consultas médicas, número de faltas no trabalho devido a exacerbações da doença, e avaliação subjetiva do paciente em relação à intervenção