34 resultados para combinatorial protocol in multiple linear regression

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction: Hypoestrogenism is the main characteristic of female aging. It promotes significant changes in body composition, both in fat mass as in lean body mass, leading to a decrease in muscle strength and physical performance. Objective: The aim of this study was to test whether menopausal status and hormone levels are associated with muscular strength and physical performance in middle-aged women. Methods: In a cross-sectional study it was collected sociodemographic data, gynecological history, anthropometric and biochemical measures in women aged 40 to 65 years in Parnamirim-RN. The menopause status (pre, peri and post menopause) was determined by menstrual history. All women underwent three dimensions of physical performance assessment: handgrip dynamometry, gait speed and chair stands test - Short Physical Performance Battery (SPPB). Categorical data were presented as absolute and relative frequencies. Quantitative data were showed as mean and standard deviation and the normality of distribution was verified with Kolmogorov-Smirnov (KS) test. Biochemical measures of estradiol and follicle-stimulating hormone (FSH) were transformed to log10. ANOVA with Tukey post-test for comparison of variables between the groups pre, peri and post-menopausal was performed and then multiple linear regression analyzes. Results: Two hundred and seventy eight women aged 50.2 (±5.58) years composed this study, being 50 women in premenopausal status (18%), 122 in perimenopausal (43.9%), and 106 postmenopausal stage (38.1%). The groups were different in age (p=0.001), marital relationship duration (p <0.001), number of pregnancies (p=0.001) and parity (p=0.001). Differences in biochemical measures were observed among the groups: estradiol (p<0.001), FSH (p<0.001), total cholesterol (p=0.001). There were no differences in gait velocity between menopausal status. Values in mean of grip strength decreased by postmenopausal women to perimenopausal and premenopausal ones (24.5 ± 5.1, 25.6 ± 5.4, 26.9 ± 4.9 for post-stage, pre and peri menopausas, respectively, p = 0.02) and the performance of chair stands test was better in premenopausal women compared with that in peri and postmenopausal status (p = 0.02). In multiple linear regression for muscle strength, the variables that remained were: age, estradiol and somatic symptoms measured by Menopause Rating Scale-MRS (R2=0.15). While for the xiv chair-stands test the predictors were number of births and FSH values (R2=0.04). Conclusion: There is a relationship between the stages of menopause and muscle performance in measures of grip strength and sit-up test and these are influenced by the fall of estrogens levels. Data suggest that the decrease in muscle strength and physical performance already appear in the transition to menopause stage, pointing to the need for more research in this area and appropriate preventive interventions

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The scope of this study was to identify socioeconomic contextual and health care factors in primary care associated with maternal near misses and their marker conditions. This is an ecological study that used aggregated data of 63 clusters formed by the municipalities of State of Rio Grande do Norte, Brazil, using the Skater method of area regionalization, as the unit of analysis. The ratio of maternal near misses and their marker conditions were obtained from the Hospital Information System of the Brazilian Unified Health System. In multiple linear regression analysis, there was a significant association between maternal near misses and variables of poverty and poor primary health care. Hypertensive disorders were also associated with poverty and poor primary care and the occurrence of hemorrhaging was associated with infant mortality. It was observed that the occurrence of maternal near misses is linked to unfavorable socioeconomic conditions and poor quality health care that are a reflection of public policies that accentuate health inequalities.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The scope of this study was to identify socioeconomic contextual and health care factors in primary care associated with maternal near misses and their marker conditions. This is an ecological study that used aggregated data of 63 clusters formed by the municipalities of State of Rio Grande do Norte, Brazil, using the Skater method of area regionalization, as the unit of analysis. The ratio of maternal near misses and their marker conditions were obtained from the Hospital Information System of the Brazilian Unified Health System. In multiple linear regression analysis, there was a significant association between maternal near misses and variables of poverty and poor primary health care. Hypertensive disorders were also associated with poverty and poor primary care and the occurrence of hemorrhaging was associated with infant mortality. It was observed that the occurrence of maternal near misses is linked to unfavorable socioeconomic conditions and poor quality health care that are a reflection of public policies that accentuate health inequalities.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

When a company desires to invest in a project, it must obtain resources needed to make the investment. The alternatives are using firm s internal resources or obtain external resources through contracts of debt and issuance of shares. Decisions involving the composition of internal resources, debt and shares in the total resources used to finance the activities of a company related to the choice of its capital structure. Although there are studies in the area of finance on the debt determinants of firms, the issue of capital structure is still controversial. This work sought to identify the predominant factors that determine the capital structure of Brazilian share capital, non-financial firms. This work was used a quantitative approach, with application of the statistical technique of multiple linear regression on data in panel. Estimates were made by the method of ordinary least squares with model of fixed effects. About 116 companies were selected to participate in this research. The period considered is from 2003 to 2007. The variables and hypotheses tested in this study were built based on theories of capital structure and in empirical researches. Results indicate that the variables, such as risk, size, and composition of assets and firms growth influence their indebtedness. The profitability variable was not relevant to the composition of indebtedness of the companies analyzed. However, analyzing only the long-term debt, comes to the conclusion that the relevant variables are the size of firms and, especially, the composition of its assets (tangibility).This sense, the smaller the size of the undertaking or the greater the representation of fixed assets in total assets, the greater its propensity to long-term debt. Furthermore, this research could not identify a predominant theory to explain the capital structure of Brazilian

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study examines the factors that influence public managers in the adoption of advanced practices related to Information Security Management. This research used, as the basis of assertions, Security Standard ISO 27001:2005 and theoretical model based on TAM (Technology Acceptance Model) from Venkatesh and Davis (2000). The method adopted was field research of national scope with participation of eighty public administrators from states of Brazil, all of them managers and planners of state governments. The approach was quantitative and research methods were descriptive statistics, factor analysis and multiple linear regression for data analysis. The survey results showed correlation between the constructs of the TAM model (ease of use, perceptions of value, attitude and intention to use) and agreement with the assertions made in accordance with ISO 27001, showing that these factors influence the managers in adoption of such practices. On the other independent variables of the model (organizational profile, demographic profile and managers behavior) no significant correlation was identified with the assertions of the same standard, witch means the need for expansion researches using such constructs. It is hoped that this study may contribute positively to the progress on discussions about Information Security Management, Adoption of Safety Standards and Technology Acceptance Model

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This research aims to understand the factors that influence intention to online purchase of consumers, and to identify between these factors those that influence the users and the nonusers of electronic commerce. Thus, it is an applied, exploratory and descriptive research, developed in a quantitative model. Data collection was done through a questionnaire administered to a sample of 194 graduate students from the Centre for Applied Social Sciences of UFRN and data analysis was performed using descriptive statistics, confirmatory factorial analysis and simple and multiple linear regression analysis. The results of descriptive statistics revealed that respondents in general and users of electronic commerce have positive perceptions of ease of use, usefulness and social influence about buying online, and intend to make purchases on Internet over the next six months. As for the non-users of electronic commerce, they do not trust the Internet to transact business, have negative perceptions of risk and social influence over purchasing online, and does not intend to make purchases on Internet over the next six months. Through confirmatory factorial analysis six factors were set up: behavioral intention, perceived ease of use, perceived usefulness, perceived risk, trust and social influence. Through multiple regression analysis, was observed that all these factors influence online purchase intentions of respondents in general, that only the social influence does not influence the intention to continue buying on the Internet from users of electronic commerce, and that only trust and social influence affect the intention to purchase online from non-users of electronic commerce. Through simple regression analysis, was found that trust influences perceptions of ease of use, usefulness and risk of respondents in general and users of electronic commerce, and that trust does not influence the perceptions of risk of non-users of electronic commerce. Finally, it was also found that the perceived ease of use influences perceived usefulness of the three groups. Given this scenario, it was concluded that it is extremely important that organizations that work with online sales know the factors that influence consumers purchasing intentions in order to gain space in their market

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This Thesis presents the elaboration of a methodological propose for the development of an intelligent system, able to automatically achieve the effective porosity, in sedimentary layers, from a data bank built with information from the Ground Penetrating Radar GPR. The intelligent system was built to model the relation between the porosity (response variable) and the electromagnetic attribute from the GPR (explicative variables). Using it, the porosity was estimated using the artificial neural network (Multilayer Perceptron MLP) and the multiple linear regression. The data from the response variable and from the explicative variables were achieved in laboratory and in GPR surveys outlined in controlled sites, on site and in laboratory. The proposed intelligent system has the capacity of estimating the porosity from any available data bank, which has the same variables used in this Thesis. The architecture of the neural network used can be modified according to the existing necessity, adapting to the available data bank. The use of the multiple linear regression model allowed the identification and quantification of the influence (level of effect) from each explicative variable in the estimation of the porosity. The proposed methodology can revolutionize the use of the GPR, not only for the imaging of the sedimentary geometry and faces, but mainly for the automatically achievement of the porosity one of the most important parameters for the characterization of reservoir rocks (from petroleum or water)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The imprecision of the frontier that separates those cognitive deficits inherent to the human physiological aging process from those which represent the early signs of nervous system degenerative pathologies ,very prevalent among the elderly, has brought attention to the need of studies aiming to establish clinical and/or laboratorial criteria to allow this differentiation. Elderly people living in poor and developing countries are frequently exposed to precarious socioeconomic conditions which facilitate the development of an array of pathologies which have metabolic and nutritional dysfunctions as the established or proposed etiological agents. The levels of certain micronutrients, such as the vitamins B12 and B9 (folic acid), and of some intermediary metabolites, such as homocysteine are being thought of as etiological factors and/or as biological markers of a group of alterations which affect the normal functioning of the nervous system with important reflexes upon cognitive performance. This study aims to investigate the influence of homocysteine, B12 vitamin and folic acid levels on the cognitive performance of the low income elderly population. This transversal study took place in Natal, Rio Grande do Norte State, Brazil, and involved 205 dwelling elderly people, users of the Programa de Saúde da Família, a public healthcare program, maintained by the city s health authorities. A multidimensional questionnaire was used to assess the socio-demographic aspects and the overall health and nutrition conditions. The cognitive performance was measured by the use of the Portuguese version of the Mini Mental State Exam (MMSE). The serum levels of homocysteine, B12 vitamin and folic acid were determined by chemiluminescence. The association between the socio-demographic and serum levels of Hcy, B12 vitamin and folic acid was determined by multiple linear regression. Serum levels higher than 13.5 μmol/l, indicative of hyperhomocysteinemia (HHcy), were found on 25.4% of the sample, being more prevalent in men (p<0.05). Deficitary levels of folic acid (<5ng/mol) and of B12 vitamin (<193 pg/ml) were found on 3.9% and 10.2% of the sample respectively. A negative correlation was found between cognitive performance with both age and HHcy and a positive correlation was found between cognitive performance and schooling. The isolated HHcy R2 values were an explanation to only 4% of the variance of the MMSE scores. However, when associated with schooling and age, this model explains about 25% of this association

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study aims to answer the following question: what are the different profiles of infant mortality, according to demographic, socioeconomic, infrastructure and health care, for the micro-regions at the Northeast of Brazil? Thus, the main objective is to analyze the profiles or typologies associated mortality levels sociodemographic conditions of the micro-regions, in the year 2010. To this end, the databases of birth and death certificates of SIM and SINASC (DATASUS/MS), were taken from the 2010 population Census microdata and from SIDRA/IBGE. As a methodology, a weighted multiple linear regression model was used in the analysis in order to find the most significant variables in the explanation child mortality for the year 2010. Also a cluster analysis was performed, seeking evidence, initially, of homogeneous groups of micro-regions, from of the significant variables. The logit of the infant mortality rate was used as dependent variable, while variables such as demographic, socioeconomic, infrastructure and health care in the micro-regions were taken as the independent variables of the model. The Bayesian estimation technique was applied to the database of births and deaths, due to the inconvenient fact of underreporting and random fluctuations of small quantities in small areas. The techniques of Spatial Statistics were used to determine the spatial behavior of the distribution of rates from thematic maps. In conclusion, we used the method GoM (Grade of Membership), to find typologies of mortality, associated with the selected variables by micro-regions, in order to respond the main question of the study. The results points out to the formation of three profiles: Profile 1, high infant mortality and unfavorable social conditions; Profile 2, low infant mortality, with a median social conditions of life; and Profile 3, median and high infant mortality social conditions. With this classification, it was found that, out of 188 micro-regions, 20 (10%) fits the extreme profile 1, 59 (31.4%) was characterized in the extreme profile 2, 34 (18.1%) was characterized in the extreme profile 3 and only 9 (4.8%) was classified as amorphous profile. The other micro-regions framed up in the profiles mixed. Such profiles suggest the need for different interventions in terms of public policies aimed to reducing child mortality in the region

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This research objectify to analyze the effects of minimum wage recovery in the household consumption in the Brazil, northeastern region of the Brazil and the state of the Rio Grande do Norte, in the period of 1995 to 2011. This is because the search for the strengthening of the internal market, via incentive policies to private demand has assumed prominence in the Government agenda. Thus, under the justification of the fierce debate about the effectiveness of countercyclical policies of Brazil, in view of the recent economic crisis, aims to: 1) retake the theoretical debate and, to a certain extent, the evolution of the theory of household consumption, as well as some conclusions about their connection with the minimum wage; 2) to describe the experiences and the effects of this legislation in economic history, with emphasis on the Brazilian case; 3) to present some of the available statistics to research bases, with attention to the specifics of each and the empirical results found for consumption in Brazil; 4) to estimate the effects of minimum wage variation in household consumption in Brazil (BR), northeast (NE) and Rio Grande do Norte (RN). From this, in order to quantify this relationship, makes inferences from the effects of the wage bill and the minimum wage on consumption, in quarterly series (with ad hoc adjustment from the "weights" of each quarter), from classic model of multiple linear regression. The hypothesis is that released: increments in income, derived from the policy of minimum wage recovery will influence directly the household consumption. However, when comparing the results between the units analyzed, the expressiveness of the northeastern families of Brazil and Rio Grande do Norte families front national dynamics with income linked to this floor, drives most significant impacts spending decisions in NE and RN, thus reducing regional disparities in the consumer. The results indicate contrary evidence, because while for the BR a unitary variation in minimum wage increases the consumption in units monetary 1.28, to the NE and RN these parameters are respectively 1.05 and 1.09

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study intended to evaluate the maze test accuracy in cognitive deficit screening in elderly with or without neuropsychological pathology. The sample included 40 healthy young (18-25 years old; mean- 21 ± 1.6), 40 healthy old (60-77 years old; mean- 67 ± 5.1) and 18 patients with probable diagnosis of Alzheimer s disease initial stage (52-90 years old; mean- 78 ± 9.2). Data analysis was made using Anova with Tukey s post hoc, multiple linear regression analysis and ROC curve analysis. According to Tukey s test Alzheimer patients spent more time (46843 ± 37926 ms) to execute the test than healthy young (5482 ± 2873 ms; p= 0.0001) and elderly (17978 ± 13700; p= 0.0001); healthy young executed test n lower time (p= 0.035). According to the regression analysis of age, education level and cognitive performance of the three groups, the cognitive performance was the predictor of the execution time. When analyzing young and elderly only age was the predictor and the cognitive performance was the only factor to influence the test of old aged healthy and patients. The ROC curve analysis indicated 72% accuracy for young and elderly and 36% for healthy and elderly patients. The maze execution time represented a better balance between sensibility (75%) and the specificity (61%) was near 13575 ms, indicating that those subjects that execute the maze in a time higher to this value may show cognitive deficit related to the executive function. According to the results it is suggested that the maze test used in this study shows a good accuracy in the cognitive deficit tracking and may discriminate age changes

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The ability to work, considered as resulting from a dynamic process between the individual resources in relation to their work, influenced from various factors such as sociodemographic, lifestyle, aging process and requirements of work. Aiming analyze the ability to work in a population of public servants, the study analyzed 132 public servants volunteers of the infrastructure sector, in a Federal Institution of Higher Education of the state of Rio Grande do Norte, Northeast, Brazil. Data were collected through a questionnaire called the Index of Capacity for Work - ICT. The variable analysis was done by using descriptive statistics of means, standard deviations, median minimum and maximum values of the scores of quantitative variables. The joint analysis of the variables was performed by multiple linear regression. The server had low capacity to work 11 (8.33%), moderate 31 (23.48%), good 54 (40.91), and Great 28 (21.21). Multiple regression analysis, adjusted for age, sex, education, age started to work, length of service, current capacity and full of disease, showed that best explained the variation of the CTI were age, current capacity and full of disease. The survey showed that 75% of the servers showed ICT below 43, so capacity low, moderate or good and only 25% of respondents had the CTI servers over 43 points, so great capacity for work. According to the recommendations of FIOH - Finnish Institute of Occupational Health, for servers that have these scores be implemented whose objective is to restore the ability to work which is low, improving the capacity for moderate work, support the capacity for the good work and maintain the ability to work great. Therefore, we recommend that the ICT is implemented in other units of the IFES survey in the perspective of achieving a real situation of all its servers, enabling the implementation of these measures as necessary to promote recovery and health of its employees.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study presents an investigation of the influence of Corporate Social Responsibility (CSR) in customer s satisfaction and loyalty through a study with car s buyers, besides that, it aims to contribute to conceptual models of satisfaction and loyalty analysis by applying the model of Johnson et al. (2001), adapted for the introduction of variables of CSR and conscious consumption, in a car dealership in Natal / RN. The methodology has a descriptive quantitative approach and for the analysis results were applied statistical methods of simple and multiple linear regression analysis, descriptive analysis and exploratory analysis. The field research provided 90 valid forms. The results show that CSR affects the image of the company studied and is also one of the elements of the compound of satisfaction and loyalty. This study concludes that CSR should be considered in the strategic and marketing actions of firms

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis treats of a avaliation of a laboral gimnastics program of a electrical energy enterprise from Rio Grande do Norte. The leading aim of this work is to analyse the laboral gimnastics program with emphasis on functional performing and personal changes of staff of different categories. The work shows two divisions: at first, it was carried out the bibliographic study approaching the concepts and historic about the ergonomy and the main focus of study, the laboral gimnastics , performing factors and lifestyle.The second time , it was carried out the field study where was used a questionnaire to a 160 staff population which participate of laboral gymnastics program; then the data were analysed through three statistics analyses: multivaried__ clusters, qui-quadrado and multiple linear regression. The results aim to the confirmation that the laboral gymnastics program developed two years ago on enterprise proposes to the white-collar and operational workers an improving on their functional performing and also, to the changes in some aspects of lifestyle, like the food, leisure and stress level. In conclusion, it was checked that the investiment in life quality programs offer benefits both to the staff and the enterprise which will account with good services and satisfaction of customer. Therefore, it was concluded that the laboral gymnastics while a ergonomic tool and a physical activity, it is an investiment which needs more and more to be strengthened and inserted by many segments of society

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work purposes the application of a methodology to optimize the implantation cost of an wind-solar hybrid system for oil pumping. The developed model is estimated the implantation cost of system through Multiple Linear Regression technique, on the basis of the previous knowledge of variables: necessary capacity of storage, total daily energy demand, wind power, module power and module number. These variables are gotten by means of sizing. The considered model not only can be applied to the oil pumping, but also for any other purposes of electric energy generation for conversion of solar, wind or solar-wind energy, that demand short powers. Parametric statistical T-student tests had been used to detect the significant difference in the average of total cost to being considered the diameter of the wind, F by Snedecor in the variance analysis to test if the coefficients of the considered model are significantly different of zero and test not-parametric statistical by Friedman, toverify if there is difference in the system cost, by being considered the photovoltaic module powers. In decision of hypothesis tests was considered a 5%-significant level. The configurations module powers showed significant differences in total cost of investment by considering an electrical motor of 3 HP. The configurations module powers showed significant differences in total cost of investment by considering an electrical motor of 5 HP only to wind speed of 4m/s and 6 m/s in wind of 3 m, 4m and 5 m of diameter. There was not significant difference in costs to diameters of winds of 3 m and 4m. The mathematical model and the computational program may be used to others applications which require electrical between 2.250 W and 3.750 W. A computational program was developed to assist the study of several configurations that optimizes the implantation cost of an wind-solar system through considered mathematical model