11 resultados para Distribuição normal

em Universidade Federal do Rio Grande do Norte(UFRN)


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In this work we analyze the skin bioimpedance statistical distribution. We focus on the study of two distinct samples: the statistics of impedance of several points in the skin of a single individual and the statistics over a population (many individuals) but in a single skin point. The impedance data was obtained from the literature (Pearson, 2007). Using the Shapiro-Wilk test and the assymmetry test we conclude that the impedance of a population is better described by an assymetric and non-normal distribution. On the other side, the data concerning the individual impedance seems to follow a normal distribution. We have performed a goodnes of fitting test and the better distribution to fit the data of a population is the log-normal distribution. It is interesting to note that our result for skin impedance is in simtony with body impedance from the literature of electrical engeneering. Our results have an impact over the statistical planning and modelling of skin impedance experiments. Special attention we should drive to the treatment of outliers in this kind of dataset. The results of this work are important in the general discussion of low impedance of points of acupuncture and also in the problem of skin biopotentials used in equipments like the Electrodermal Screen Tests.

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O aborto provocado na adolescência como problema de saúde pública, é tema deste estudo que teve como objetivo identificar os motivos que levam adolescentes a provocar o aborto. A multidisciplinariedade do Programa de Pós Graduação em Ciências da Saúde, da Universidade Federal do Rio Grande do Norte, proporcionou o convívio com vários pesquisadores, bem como contribuiu para a coorientação e o crescimento deste estudo e da Pesquisadora com aquisição de conhecimentos diversificados e inovadores. Estudo transversal, quantitativo, analítico, usou questionário semi-estruturado como instrumento que foi aplicado em dez escolas. Trabalhou-se com jovens do sexo feminino, dos 12 aos 19 anos de idade. A amostra representativa foi calculada considerando-se o número de internações por curetagens na cidade de Maceió em 2004. O Banco de Dados foi analisado pelo programa Epi Info versão 3.3.2. Foram usados os testes Quiquadrado, Odds Ratio, Risco Relativo e Regressão Logística. A amostra foi de 2592 jovens, numa distribuição normal, com idade média e mediana de 15 anos, desvio padrão de 1,7. A maioria das jovens era solteira (95,7%), não trabalhava (94,1%), residia com ambos os pais (66,2%) e conhecia algum método contraceptivo (95,5%). Do total das adolescentes estudadas, 52,4% estudava o nível educacional médio. Delas 21,6% tinham vida sexual ativa, 6,4% engravidaram e 5,7 % abortaram. A maioria (95,5%) afirmou conhecer algum método contraceptivo, destas 70,1% tinha mais de 15 anos e os métodos mais citados foram os de barreira/hormonal com 72,4%. Analisando o Risco Relativo observou-se que o risco era significativo e protetor para o começo da vida sexual antes dos 15 anos de idade. Apenas 32,4% delas citaram algum tipo de complicação o aborto. Foi significativa a relação entre a idade e as citações da morte, da esterilidade como a complicação do aborto. A maioria recebeu apoio para abortar (63,8%), amigas foram as que mais apoiaram (32,9%), sendo significativa a relação entre o apoio recebido para abortar e a pratica do ato. O motivo mais citado foi o medo da reação dos pais (57,7%), esteja este motivo apontado como único ou associado a outros. A análise de significância entre as variáveis dicotômicas, forneceu 8 variáveis significativas, 2 protetoras para o abortamento: idade de 12-14 anos e conversar com os pais sobre sexo. As demais variáveis: estado marital com companheiro, vida sexual ativa, gravidez anterior, uso de método contraceptivo, recebimento de apoio para abortar e necessidade de internamento pós-aborto, foram promotoras ao abortamento. Receber apoio para abortar foi a mais significativa para abortar, estado marital com companheiro foi fator de proteção para o ato. Conclui-se que o apoio para abortar foi a variável mais significativa deste estudo reforçando a importância do grupo na adolescência. Sugere-se maior atenção as ações educativas como prevenção para riscos na saúde reprodutiva dos jovens

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This study aimed to determine the influence of strength training (ST), in three weekly sessions over ten weeks, on cardiovascular parameters and anthropometric measurements. It is a before and after intervention trial, with a sample composed of 30 individuals. Participants were adults aged between 18 and 40 years, from both sexes and sedentary for at least three months previously. Tests were computed ergospirometry, CRP, PWV and body composition (dependent variables) before and after the experiment. Independent variables, age and sex, were considered in order to determine their influence on the dependent variablesevaluatedend. By comparing the initial cardiovascular parameters with those obtained after intervention in patients undergoing the ST proposed (a Student s t-test was conducted within each group for samples matched to parameters with normal distribution, while the Wilcoxin was applied for those without), there was no significant difference in PWV(p =0469) or PCR(p =0.247), but there was an increase in anaerobic threshold(AT) (p=0.004) and Maximal Oxygen Uptake(VO2max) (p =0.052). In regard to anthropometric measures, individuals significantly reduced their body fat percentage (p<0.001) and fat mass (p<0,001), as well as increasing lean mass (p<0.001). However, no changes were recorded in the waist-to-hip ratio (WHR) (p= 0.777), body mass (p=0.226) or body mass index (BMI) (p =0.212). Findings of this study lead us to believe that the proposed ST, and did not increase the VOP or PCR improves cardiorespiratory capacity and body composition. Devotees of this training can therefore safely enjoy all its benefits without risk to the cardiovascular system

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The present work had as objective to apply an experimental planning aiming at to improve the efficiency of separation of a new type of mixer-settler applied to treat waste water contaminated with oil. An unity in scale of laboratory, was installed in the Post-graduation Program of Chemical Engineering of UFRN. It was constructed in partnership with Petrobras S.A. This called device Misturador-Decantador a Inversão de Fases (MDIF) , possess features of conventional mixer-settler and spray column type. The equipment is composed of three main parts: mixing chamber; chamber of decantation and chamber of separation. The efficiency of separation is evaluated analyzing the oil concentrations in water in the feed and the output of the device. For the analysis one used the gravimetric method of oil and greases analysis (TOG). The system in study is a water of formation emulsified with oil. The used extractant is a mixture of Turpentine spirit hydro-carbons, supplied for Petrobras. It was applied, for otimization of the efficiency of separation of the equipment, an experimental planning of the composite central type, having as factorial portion fractionary factorial planning 2 5-2, with the magnifying of the type star and five replications in the central point. In this work, the following independents variables were studied: contents of oil in the feed of the device; volumetric ratio (O/A); total flowrate ; agitation in the mixing chamber and height of the organic bed. Minimum and maximum limits for the studied variables had been fixed according previous works. The analysis of variance for the equation of the empirical model, revealed statistically significant and useful results for predictions ends. The variance analysis also presented the distribution of the error as a normal distribution and was observed that as the dispersions do not depend on the levels of the factors, the independence assumption can be verified. The variation around the average is explained by 98.98%, or either, equal to the maximum value, being the smoothing of the model in relation to the experimental points of 0,98981. The results present a strong interaction between the variable oil contents in the feed and agitation in the mixing chamber, having great and positive influence in the separation efficiency. Another variable that presented a great positive influence was the height of the organic bed. The best results of separation efficiency had been obtained for high flowrates when associates the high oil concentrations and high agitation. The results of the present work had shown excellent agreement with the results carried out through previous works with the mixer-settler of phase inversion

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It has been shown that the development of peri-implant mucositis is associated with biofilm accumulation. It is believed that the therapeutic approaches used in periodontal disease may have a positive effect in the cases of peri-implant disease. The aim of this study was to evaluate the effectiveness of non-surgical treatment of peri-implant mucositis, with or without the use of chlorhexidine 0,12% in subjects rehabilitated with osseointegrated implants. Thus, patients were randomly divided into test group (chlorhexidine surgical therapy) and control (non-surgical treatment). This therapy consisted of an adaptation of the (Full Mouth scalling and Root Planing) nonoperative protocol FMSRP, but without the use of ultrasound. The visible plaque index (VPI), gingival bleeding index (GBI), probing depth (PD), bleeding on probing (BOP) and keratinized mucosa clinical parameters were evaluated at baseline and at different times after treatment. The data were not normally distributed and the implant was considered the sampling unit. Data were analyzed using Fri edman and Wilcoxon chi-square (=5%), tests using the Statistical Package for Social Sciences 17.0 (SPSS). Thus, 119 implants were evaluated, 61 in the test group and 58 in the control group. The results showed statistically significant differences for the variables: average BTI implants in both groups (p<0,001), mean ISG implants both in the test group (p<0,001), and control (p= 0,006) of implants; PS for the test group (p< 0,001) and control (p = 0,015) and SS (p<0,001) in the two treatment groups. However, there was no statistically significant difference when the groups were compared. The PS and SS variables showed no statistically significant difference in any of independent interest to the study (age, sex, smoking, treatment group, keratinized mucosa at different times, peri-implant biotype, average VPI implants and GBI). Thus, it can be concluded that both the mechanical treatment isolated as its association with chlorhexidine mouthwash 0.12% can be used for the treatment of peri-implant mucositis. Moreover, the condition of oral h ygiene has improved between baseline and six months and the depth and bleeding on probing decreased after three and six months

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The segmentation of an image aims to subdivide it into constituent regions or objects that have some relevant semantic content. This subdivision can also be applied to videos. However, in these cases, the objects appear in various frames that compose the videos. The task of segmenting an image becomes more complex when they are composed of objects that are defined by textural features, where the color information alone is not a good descriptor of the image. Fuzzy Segmentation is a region-growing segmentation algorithm that uses affinity functions in order to assign to each element in an image a grade of membership for each object (between 0 and 1). This work presents a modification of the Fuzzy Segmentation algorithm, for the purpose of improving the temporal and spatial complexity. The algorithm was adapted to segmenting color videos, treating them as 3D volume. In order to perform segmentation in videos, conventional color model or a hybrid model obtained by a method for choosing the best channels were used. The Fuzzy Segmentation algorithm was also applied to texture segmentation by using adaptive affinity functions defined for each object texture. Two types of affinity functions were used, one defined using the normal (or Gaussian) probability distribution and the other using the Skew Divergence. This latter, a Kullback-Leibler Divergence variation, is a measure of the difference between two probability distributions. Finally, the algorithm was tested in somes videos and also in texture mosaic images composed by images of the Brodatz album

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The gestation process, in general, is a very important event on a woman’s life and it brings phisical, phisiological and emotional changes, which by itself is an experience full of intense feelings. By late-aged pregnancy we mean those which occurs at the age of 35 or further. The occurance of this type of pregnancy is rising in Brasil and throughout the world, factors such as, better access to birth control resources and the search for financial stability explains the pregnancy delay. Important processes like resilience and social support can help late-aged pregnant women, in a benefical way, to adapt to the gestation process. Resilience is the capacity that a certain individual or group of individuals have to go through an adverse situation, be able to overcome it and become streghtened, transforming it in motivation for its biopsichosocial development. Social support is a complex and dinamic process that involves transactions between individuals and their social networks, meeting the social needs, promoting and complementing the personal resources that they have to face new demands. This research has the intention of raising information about the issues of late-aged pregnant women in the County of Natal- RN, the main objective was to evaluate the resilience indicators and the social support on late-aged pregnant women in the Natal-RN County. A transversal cut, correlational and descriptive research that was done with 150 lateaged pregnant women. The tools that were used were: A form with sociodemographic and gestation info, the scale of resilience and social support. An eletronic spreadsheet sofware (Excel e SPSS 21.0) was used to analize data which helped on the statistics according to its variables and the objective of this work. For the nominal variables, relative frequencies were used and for continuous the Pearson correlation and determination coefficient were used, regarding that; the sample had a normal distribution. The project fulfilled the ethnic aspects prescribed by Resolution 466/12 of the National Health Council, with a favorable decision (356.436/ 2013) of the UFRN Ethics on Research Committee. Most of the pregnant women had a low money income and education level, born in the state of Rio Grande do Norte they had an average age of 37,49 (±2,577), catholic, married, house wives, they had more than one child and were on their third trimester of pregnancy; they also had a low past abortion rate, not having planned their pregnancy, with an average of 4,22 (±2,506) pre-natal appointments, residing with an average of 3,673 (±1,397) people, having used any sort of birth control device and having high indicators of resilience and social support. The correlations kept between resilience, social support and some of the social demographics and gestation variables were considered low. Such data points out the fact that most of these women were in a stable relationship; they hadn’t had a past of abortion, they were involved with some kind of religion, they were not first pregnancy mothers, had an age on which they are not considered inexperienced mothers and even had scored high on the social support scale, these may all possibly be the most contributing factors on development and resilience building on these 35 years or more mothers. We expect that the data and information from this research may add up knowledge, actions and improvements regarding late-aged pregnant women and the pregnancy phenomena in general.

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Cephalometric analysis is the mensuration of linear and angular measures through demarcation points as distances and lines on teleradiography, and is considered of fundamental importance for diagnosis and orthodontic planning. In this manner, the objective of this research was to compare cephalometric measurements obtained by dentists and radiologists from the analysis of the same radiograph, in a computerized cephalometric analysis program. All research participants marked 18 cephalometric points on a 14-inch notebook computer, as directed by the program itself (Radiocef 2®). From there, they generated 14 cephalometric parameters including skeletal, dental-skeletal, dental and soft tissue. In order to verify the intra-examiner agreement, 10 professionals from each group repeated the marking of the points with a minimum interval of eight days between the two markings. The intra-group variability was calculated based on the coefficients of variation (CV). The comparison between groups was performed using the Student t-test for normally distributed variables, and using the Mann-Whitney test for those with non-normal distribution. In the group of orthodontists, the measurements of Pog and 1-NB, SL, S-Ls Line, S-Li Line and 1.NB showed high internal variability. In the group of radiologists, the same occurred with the values of Pog and 1-NB, S-Ls Line, S-Li Line and 1.NA. In the comparison between groups, all the analyzed linear values and two angular values showed statistically significant differences between radiologists and dentists (p <0.05). According to the results, the interexaminer error in cephalometric analysis requires more attention, but does not come from a specific class of specialists, being either dentists or radiologists.

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Introdução: A obesidade infantil apresenta incidência crescente e as possíveis comorbidades, como alteração da função respiratória, estão cada vez mais presente nessa faixa etária. O tecido adiposo impõe carga ao sistema respiratório o que leva a um padrão restritivo. Essa condição sofre alterações com as mudanças posturais, onde a gravidade influencia o padrão respiratório de acordo com o posicionamento adotado. Objetivo: Avaliar a distribuição dos volumes total e regional e o movimento tóracoabdominal de crianças e adolescentes que estão acima do peso nas posturas supino e sentado. Métodos: Cinqüenta e duas crianças/adolescentes (8-12 anos) divididas em três grupos: Grupo Obeso (GO=22); Grupo Sobrepeso (GSP=9); Grupo Controle (GC=21) foram avaliadas quanto às medidas antropométricas, teste de função pulmonar, exame das pressões respiratórias máxima e a pletismografia optoeletrônica em duas posturas, supino e sentado, durante a respiração tranquila. Resultados: As crianças que estão obesas apresentaram maiores valores em relação ao GSP e GC das seguintes variáveis espirométricas: volume expiratório forçado no primeiro segundo (VEF1) (p<0.05) e capacidade vital forçada (CVF) (p<0.01). No exame de manovacuometria o GO apresentou um aumento na pressão inspiratória máxima (PImáx) (p<0.01) em comparação com os outros grupos. Quanto à distribuição do volume corrente, o GO possui uma maior contribuição do compartimento abdominal (AB) na postura supina (p<0.05) em relação ao GC e GSP, enquanto que na postura sentada os grupos não diferiram em relação à distribuição dos volumes. O GO apresentou maior assincronia na postura supina (p<0.05) e maior velocidade de encurtamento (p<0.05) em relação os outros grupos. Conclusão: A obesidade em crianças/adolescentes não provoca prejuízos na função pulmonar, incrementa a força muscular inspiratória, aumenta a participação do compartimento AB e a assincronia no MTA na postura em supino, conclui-se que a postura supina associada à obesidade provoca aumento da sobrecarga do diafragma, desfavorecendo o desempenho do sistema respiratório.

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Most algorithms for state estimation based on the classical model are just adequate for use in transmission networks. Few algorithms were developed specifically for distribution systems, probably because of the little amount of data available in real time. Most overhead feeders possess just current and voltage measurements at the middle voltage bus-bar at the substation. In this way, classical algorithms are of difficult implementation, even considering off-line acquired data as pseudo-measurements. However, the necessity of automating the operation of distribution networks, mainly in regard to the selectivity of protection systems, as well to implement possibilities of load transfer maneuvers, is changing the network planning policy. In this way, some equipments incorporating telemetry and command modules have been installed in order to improve operational features, and so increasing the amount of measurement data available in real-time in the System Operation Center (SOC). This encourages the development of a state estimator model, involving real-time information and pseudo-measurements of loads, that are built from typical power factors and utilization factors (demand factors) of distribution transformers. This work reports about the development of a new state estimation method, specific for radial distribution systems. The main algorithm of the method is based on the power summation load flow. The estimation is carried out piecewise, section by section of the feeder, going from the substation to the terminal nodes. For each section, a measurement model is built, resulting in a nonlinear overdetermined equations set, whose solution is achieved by the Gaussian normal equation. The estimated variables of a section are used as pseudo-measurements for the next section. In general, a measurement set for a generic section consists of pseudo-measurements of power flows and nodal voltages obtained from the previous section or measurements in real-time, if they exist -, besides pseudomeasurements of injected powers for the power summations, whose functions are the load flow equations, assuming that the network can be represented by its single-phase equivalent. The great advantage of the algorithm is its simplicity and low computational effort. Moreover, the algorithm is very efficient, in regard to the accuracy of the estimated values. Besides the power summation state estimator, this work shows how other algorithms could be adapted to provide state estimation of middle voltage substations and networks, namely Schweppes method and an algorithm based on current proportionality, that is usually adopted for network planning tasks. Both estimators were implemented not only as alternatives for the proposed method, but also looking for getting results that give support for its validation. Once in most cases no power measurement is performed at beginning of the feeder and this is required for implementing the power summation estimations method, a new algorithm for estimating the network variables at the middle voltage bus-bar was also developed

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