Síndrome metabólica e fatores de risco relacionados em crianças e adolescentes com excesso de peso na cidade do Natal

Nas últimas décadas, houve grande aumento da prevalência de obesidade, inclusive na faixa etária pediátrica. Com isso, aumentou o número de crianças e adolescentes afetados por síndrome metabólica (SM), diabetes tipo 2 (DM2) e doenças cardiovasculares (DCV), doenças anteriormente consideradas quase exclusivas de adultos. Os objetivos do estudo foram identificar e correlacionar marcadores antropométricos (IMC- índice de massa corpórea, CA- circunferência abdominal, RCQ- razão cintura/quadril, RCArazão cintura altura e PSE- prega subescapular), PAS e PAD- pressão arterial sistólica e diastólica, respectivamente, e laboratoriais (CT- colesterol total, HDL, LDL, TGL- triglicérides, I/G- razão insulina glicose, HOMA- homeostatic model assessment for insulin resistance) de risco para o desenvolvimento de SM e observar a sua prevalência em crianças e adolescentes com excesso de peso. Foi conduzido estudo transversal, em amostra aleatória, de conveniência, onde foram avaliadas 60 crianças e adolescentes com excesso de peso, atendidas no ambulatório de endocrinologia pediátrica do Hospital de Pediatria da Universidade Federal do Rio Grande do Norte (UFRN) com idade mínima e máxima de 7 e 15 anos, de maio de 2009 a abril de 2010. Foram admitidos os indivíduos que apresentavam sobrepeso (IMC P > 85 e < 95) ou obesidade (IMC P > 95) (CDC, 2000) e história familiar positiva para DM2 em parentes de primeiro ou segundo grau ou algum dos sinais de resistência insulínica (acantose, hipertensão arterial, dislipidemia, síndrome de ovários policísticos). 2 O componente individual para SM mais prevalente foi o percentil da CA ≥ 90 (58,3%), seguido de HDL ≤ 40 mg/dl (36,6%). Na regressão linear simples, observaram-se as variações para mais nos parâmetros laboratoriais e de PA para cada unidade de aumento de IMC, CA, RCA, RCQ e PSE, sendo significantes as seguintes correlações: CA com TGL, HOMA IR, I/G, PAS e PAD; RCQ com TGL, HOMA, I/G, LDL e glicemia; RCA com TGL; PSE com TGL, HOMA-IR, I/G e PAS; e IMC com HOMA IR, I/G, PAS e PAD. De acordo com os critérios da IDF (Federação Internacional de Diabetes International Diabetes Federation) 2007, o diagnóstico de SM foi encontrado em seis indivíduos (10%). Do total, oito (13,3%), estavam em situação de sobrepeso e 52 (86,6%), obesos. As evidências de correlação CA e RCQ, medidas de obesidade centrípeta, com vários marcadores como TGL e HOMA, já sabidamente relacionados à SM, chamam atenção para a necessidade de utilização dessas medidas de forma mais rotineira na prática pediátrica, por serem de fácil obtenção, baixo custo e método não invasivo. Os valores de CA, RCQ, RCA e PSE, quando elevados devem justificar maior detalhamento na avaliação laboratorial de possível resistência insulínica. É importante a identificação de crianças e adolescentes que preencham os requisitos para o diagnóstico da SM, pois são indivíduos de maior risco metabólico e devem ser adequadamente acompanhados.

Saúde física e emocional de cuidadores da cidade de Santa Cruz-RN: perfil epidemiológico e fatores associados

Taking care for an impaired elderly is a hard and costly task that could affect directly the caregiver health. The purpose of this study was to evaluate the physical and mental health of elderly caregivers from the city of Santa Cruz-RN and analyze the potential correlated factors through an observational analytic design of a crosssectional. A multidimensional questionnaire was used to evaluation of the social demographics characteristics and those related to the care activity, as well as the caregivers´ physical and mental health. It was realized a descriptive analyze using frequency distribution and measures of the central tendency and dispersion to description of the caregivers. To verify the magnitude of the association between the variables was used the bivariate analysis through the Pearson and Spearman correlations and qui-square test. To evaluation of the association of the correlated factors to the adverse outcome with the caregivers´ physical and mental health was made a multivariate analysis by logistic binary regression and multiple linear regression models. The final sample was constituted by 304 persons, mostly women with a mean age of 50.3 ±16.8 years. The principal factors related to the physical health were age, stress and life satisfaction. Be a male caregiver, caring for a little while the elderly with cognitive deficit and not been spouse were related to worse mental health. Have worse physical health, high stress, depressive symptomatology, burden and low levels of satisfaction were also related to the mental health. After adjust through multiple linear regression was observed R2 values of R2=0,21 for Stress, R2 =0,17 for Depressive Symptomatology, R2 =0,21 for Burden and R2 =0,16 for Satisfaction. The attainment of the factors associated with caregiver´s health can help in the elaboration of specifics politics witch the goal is the integral attention to the elderly and his caregiver. The inability of continuous taking care could result in adverse outcomes such as institutionalization, impairment and death

Equações preditivas para as pressões respiratórias máximas de crianças brasileiras

I ntroduction: The assessment of respiratory muscle strength is important in the diagnosis and monitoring of the respiratory muscles weakness of respiratory and neuromuscular diseases. However, there are still no studies that provide predictive equations and reference values for maximal respiratory pressures for children in our population. Aim: The purpose of this study was to propose predictive equations for maximal respiratory pressures in healthy school children. Method: This is an observational cross-sectional study. 144 healthy children were assessed. They were students from public and private schools in the city of Natal /RN (63 boys and 81 girls), subdivided in age groups of 7-8 and 9-11 years. The students presented the BMI, for age and sex, between 5 and 85 percentile. Maximal respiratory pressures were measured with the digital manometer MVD300 (Globalmed ®). The maximal inspiratory pressure (MIP) and maximal expiratory pressures (MEP) were measured from residual volume and total lung capacity, respectively. The data were analyzed using the SPSS Statistics 15.0 software (Statistical Package for Social Science) by assigning the significance level of 5%. Descriptive analysis was expressed as mean and standard deviation. T'Student test was used for unpaired comparison of averages of the variables. The comparison of measurements obtained with the predicted values in previous studies was performed using the paired t'Student test. The Pearson correlation test was used to verify the correlation of MRP's with the independent variables (age, sex, weight and height). For the equations analysis the stepwise linear regression was used. Results: By analyzing the data, we observed that in the age range studied MIP was significantly higher in boys. The MEP did not differ between boys and girls aged 7 to 8 years, the reverse occurred in the age between 9 and 11 years. The boys had a significant increase in respiratory muscle strength with advancing age. Regardless sex and age, MEP was always higher than the MIP. The reference values found in this study are similar to a sample of Spanish and Canadian children. The two models proposed in previous studies with children from other countries were not able to consistently predict the values observed in this studied population. The variables sex, age and weight correlated with MIP, whereas the MEP was also correlated with height. However, in the regression models proposed in this study, only gender and age were kept exerting influence on the variability of maximal inspiratory and expiratory pressures. Conclusion: This study provides reference values, lower limits of normality and proposes two models that allow predicting, through the independent variables, sex and age, the value of maximal static respiratory pressures in healthy children aged between 7 and 11 years old

Equacões preditivas para as pressões respiratórias estáticas máximas de adolescentes brasileiros

Introduction: The reference values and prediction equations for maximal respiratory pressures (MRP) differ significantly between the available studies. This large discrepancy can be attributed to the different methodologies proposed. Although the importance of MRP is widely recognized, there are no Brazilian studies that provide predictive equations and reference values for PRM adolescents. Objectives: The purpose of this study was to provide normal values and propose predictive equations for maximal static respiratory pressures of Brazilian adolescents. Methods: An observational cross-sectional study, which evaluated 182 adolescents of both sexes aged between 12 and 18 years, enrolled in schools of the state and private in the city of Natal / RN. The selection of schools and participants of the study was randomly through a lottery system. The spirometric evaluation was performed through the digital spirometer One Flow FVC prior to the assessment of respiratory muscle strength. The MICs were measured with MVD digital manometer 300. Statistical analysis was performed using the SPSS 17.0 software STATISTICS, assigning the significance level of 5%. The normality of data distribution was verified using the Kolmogorov-Smirnov (KS). The descriptive analysis was expressed as mean and standard deviation. We used one-way ANOVA test to verify the difference of the averages of MRPs between age and gender and comparing the averages of MRPs between levels of physical activity. The test t'Student unpaired compared the averages of MRPs being ages and sexes. The comparison of mean values obtained in this study PRM with the values predicted using the equations mentioned above was relizada by testing paired t'Student. To verify the correlation between the PRM and the independent variables (age, weight, height) was used Pearson correlation test. Levene's test evaluated the homogeneity of variance. To obtain predictive equations analysis was used stepwise multiple linear regression. Results: There was no significant difference in mean age between the PRM. The male adolescents, regardless of age, showed superiority in MRP values when compared to the opposite sex. Weight, height and sex correlated with the PRM. Regression analysis suggested in this study, pointed out that the weight and sex had an influence in MIP and MEP only in relation to sex influenced. The mean for each PRM adolescents classified as very active were superior to those observed in adolescents classified as irregularly active. Conclusion: This study provides reference values and two models of predictive equations for maximal inspiratory and expiratory pressures, and to establish the lower limits of normality that will serve as an indispensable condition for careful evaluation of respiratory muscle strength in Brazilian adolescents

Características sociodemográficas, hábitos de sono, estado cognitivo e funcional após acidente vascular cerebral

ABSTRACT Introduction: The cerebrovascular accident (CVA) is an important cause of neurological impairment. Few data about the factors associated with morbidity of cerebrovascular accident are found in Brazil. Objectives: Evaluate sociodemographic characteristics, sleep habits, cognitive and functional status of patients with cerebrovascular accident. Methods: The patients evaluated through questionnaire Step 1 to survey the sociodemographic characteristics and Modified Rankin Scale for functional assessment. The neurological degree was evaluated by the National Institutes of Health Stroke Scale (NIHSS), the sleep Habits questionnaire for sleep and cognitive status by the Mini-Examination of the Mental State (MEMS). The data were analyzed using the chi-square test to determine differences in proportions of variables and linear regression analysis. Results: 305 patients were evaluated and the larger number of subjects was between 50 and 69 years (40%), most patients had no formal education (40.3%) and had ischemic type of cerebrovascular accident (72.5%). In the analysis of the functionality it was found that most patients had moderate impairment (55.1%). The results of the sleep habits showed that 63,6% of patients had one more person in the bedroom,12,3% complained about too much noise in the 11 room and 35% of too much light. From these patients 5,8% were smokers, 7,8% and 70,1% drank coffee drinkers, 28,6% had difficulty in initiate to sleep and woke up 37,6% in the middle of the night. Were showed complaints about nightmares (11%), feeling of suffocation (37,7%) and 35% felt very sleepy during the day. In addition, 95% were unemployed, 80,5% did not perform physical activities and 95,4% did not perform mental activities. The cognitive screening conducted a determined association of cognitive status with age and education level and neurological status. Conclusion: The study showed a high frequency of cases of cerebrovascular accident with functional dependence in a moderate degree, identified that many patients do not follow hygienic measures of sleep and found that the assessment of cognitive deficits must take into consideration the age, educational level and degree of neurological patients. We suggest the need for programs of assistance to victims of cerebrovascular accident patients, with a multidimensional approach including the rehabilitation team, the role of sleep medicine and Neuropsychology, so that patients have access to a more appropriate functional rehabilitation, develop a lifestyle that ensures a good sleep quality and are evaluated and rehabilitated with regard to cognitive impairment

Prevalência de incontinência urinária e fatores associados em idosos institucionalizados

Urinary incontinence (UI) is a geriatric syndrome that is especially prevalent in institutionalized individuals, and that causes economic and social impacts derived from treatment costs and overload of caregiver. UI also entails physical consequences to the health of the elderly, such as urinary tract infections or pressure ulcers, among other health problems. However, the existing national research on this condition is still scarce and comprises serious methodological biases. Therefore, the objective of this study is to determine the prevalence of urinary incontinence and associated factors in institutionalized elderly. A cross-sectional study is presented herein, conducted between October and December, 2013 and carried out in 10 nursing homes in the city of Natal (Northeast Brazil). UI was verified through the program Minimum Data Set version 3.0, which was also used to assess fecal incontinence, urinary devices and UI control programs. Data collection included sociodemographic information, UI characterization, as well as variables related to the institution itself and to health conditions (comorbidities, medication, pelvic floor surgery, Barthel Index for functional capacity and Pfeiffer test for cognitive status). Bivariate analysis was performed using the Chi-Square Test (or Fisher‟s Exact Test) and the Linear Chi-Square Test, calculating the prevalence ratio with 95% confidence interval. Variables with p value under 0.20 were included in the multivariate analysis, which was performed using the Stepwise Forward logistic regression. The inclusion of variables in the final model depended on the likelihood ratio test, absence of multicollinearity and on the Hosmer-Lemeshow test. A statistical significance level of 0.05 was considered. Six (1.8%) hospitalized elderly, one individual in palliative care (0.3%) and one (0.3%) individual under the age of 60 were excluded from the study. The final sample consisted of 321 elderly, mostly females, with a mean age of 81.5 years. The prevalence of UI was 59.43% and the final model revealed statistically a significant association between UI and white race, physical inactivity, stroke, mobility constraints and cognitive decline. The most frequent UI type was functional UI due to physical or cognitive disability, and incontinence control measures were applied only to a minority of residents (approximately 8%). It is concluded that UI is a health issue that affects more than half of the institutionalized elderly, and is associated with white race, physical inactivity, stroke and other geriatric syndromes such as immobility and cognitive disability. Most of these associated factors are modifiable and therefore the findings of this study highlight the importance of UI prevention and treatment in nursing homes, which include general measures, such as physical and psychosocial activities, and specific measures, such as prompted voiding

Gestão Sustentável da água: um estudo da conscientização ambiental em atividades residenciais urbanas

The search for sustainable solutions through an appropriate environmental administration of the available natural resources, that comes from encounter to the aspirations of preservation of the environment and of the human being, in way to diagnose and to solve the environmental and social problems with the smallest possible impact to the nature and the man, it is the great challenge, so much for that generation, as for the future generations. The study of the environmental problems of the water and the participation and the social actors' environmental understanding as a whole, interferes in the field of the thematic environmental international, contemplating the strategic need of an appropriate administration of that very natural one, through a program returned to the diagnosis of the problems and in the search of compatible maintainable solutions, in a social and environmental politics of planning and environmental education, centered above all in the citizen's voice , user of that system. The present thesis she seeks to study the problem of the maintainable administration of the water, focusing the participation and the citizen's environmental understanding in the use of that very natural one for urban residential activities, in what concerns the approach and analyses of variables that treat of the measurement of general knowledge and you adapt, sense of community of the access to the means of information and of the attitudes and environmental behaviors, besides the variables of partner-demographic characterization or personal identification of the interviewed ones of an exploratory research of the type " survey ", accomplished through a stratified aleatory sampling, being the strata each one of the 4 (four) Political-Administrative Areas of the Natal city, having happened the collection of the data in the period of february to april/2002. The methodology used in this work it constitutes in the application of questionnaires with scales of the type Likert to measure the echo-varied of the study, besides a partner-demographic scale for the characterization of the studied sample. For the analysis of the results, it was made an exploratory descriptive study initially, followed by the use of techniques statistical multivariate s, such as, factorial analysis through the application of main components, besides the accomplishment of studies of multiple lineal regression. To complement this study, the accomplishment of Tests of Independence was proceeded through the Qui-square of Pearson, in way to verify the dependence of the associations between the partner-demographic variables and the principal selected variables and presents in the resulting factors of the factorial analysis. The results appear for a low level of environmental knowledge, of access to the information and community's sense, besides the verification that the principal factors resultants send for the need of feeling emphasis in the programs and administration actions addressed for the environmental understanding, the behaviors and attitudes that approach the information and the environmental education, besides the reuse of the water

Imagens do terceiro setor: um estudo com pais e responsáveis financeiros das organizações educacionais

The present report is the result of an applied research in the educational entities of the third sector, aiming to demonstrate whether the financial influences the perception of users on the image of those entities. For both used the prospect of integrative marketing relationship adapting to and developing a set of indicators which bore the measurement of images from the model of Machado et al (2005) and Kotler and Fox (1994). The sample included a total of 187 parents and financial responsibility in 03 (three) institutions of education in Natal / RN. These data were processed by multivariate statistical analysis, factor analysis, linear regression, analysis of cluster and discriminant analysis. The factor analysis also identified 6 images perceived by users of services. Next were the relationships of cause and effect between the financial and images formed. In discriminant analysis, was identified two distinct groups of parents and guardians with financial perceptions similar and well defined. The result of the work shows that the differential level of financial participation of parents and guardians not influence the formation of the images formed from educational institutions of the third sector

Determinantes da Estrutura de Capital de Companhias Abertas Brasileiras Não-Financeiras: Um Estudo Empírico com Dados em Painel

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

Influência dos intermediários de distribuição de produtos turísticos no processo de decisão do meio de hospedagem pelo consumidor

This study examines the complex hotel buyer decision process in front of the tourism distribution channels. Its objective is to describe the influence level of the tourism marketing intermediaries, mainly the travel agents and tour operators, over the hotel decision process by the buyer-tourist. The data collection process was done trough a survey with three hundred brazilian tourists hosted in nineteen hotels of Natal, capital of Rio Grande do Norte, Brazil. The data analysis was done using some multivariate statistic techniques as correlation analysis, multiple regression analysis, factor analysis and multiple discriminant analysis. The research characterizes the hotel services consumers profile and his trip, and identifying the distribution channels used by them. Furthermore, the research verifies the intermediaries influence exercised over hotel buyer decision process, looking for identify causality relations between the influence level and the buyer profile. Verifies that information about hotels available on internet reduces the probability that this influence can be practiced; however it was possible identifying those consumers considers this information complementary and non-substitutes than the information from intermediaries. The characteristics of the data do not allow indentifying the factors that constraint the intermediaries influence neither identifying discriminant functions of the specific distribution channel choice by consumers. The study concludes that consumers don t agree in have been influenced by intermediaries or don t know if they have, still considering important to consult them and internet doesn t substitute their function as information source

Fatores que influenciam a aceitação de práticas avançadas de gestão de segurança da informação: um estudo com gestores públicos estaduais no Brasil

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

Fatores que influenciam a intenção de compra online: aplicação de um modelo adaptado de aceitação da tecnologia para o comércio eletrônico

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

Os efeitos das reclamações online na lealdade dos consumidores: um estudo experimental

In an environment of constant change, technological developments, market competition and more informed consumers, the search for a lasting relationship through the conquest of loyalty has become the objective of companies. However, several authors suggest that this loyalty can be affected by negative comments available on the internet. Therefore, this dissertation has as objective to examine if the complaints are available on the internet impact the loyalty to a brand of mobile phone. The research used as the basis the Expanded NCSB model suggest by Johnson et al. (2001), studying five prominent drives of loyalty: image/brand reputation, affective commitment, calculative commitment, perceived value and trust, beyond the satisfaction construct as moderator variable. The research method adopted was the experimental design which included 285 undergraduate students, with the trial which included 285 undergraduate students, with the field study of the mobile industry, specifically, the brands of cell phones. The research approach was quantitative and methods were descriptive statistics, factor analysis, cluster analysis, linear regression and non-parametric test of Wilcoxon for data analysis. Of the 16 hypothesis stemmed from the research model proposed, 12 were confirmed. The results showed that the complaint available on the internet, here represented by the available on the site Reclame Aqui, may impact consumer perceptions about brand loyalty, as well as its antecedents, being that these complaints can affect all the consumers, regardless of historical satisfaction with the brand. It also noted the positive relationship between the independent variables trust, image/brand reputation, perceived value, affective commitment and calculative commitment and the dependent variable - loyalty, even when considering the data obtained after exposure to the complaint. However, no unanimous conclusion that the relationship between these variables was strongest in the group with satisfactory experience. At the first moment of the research, the trust was the most important variable for the formation of loyalty. However, after exposure to treatment, the image/brand reputation, was more relevant. Contributions of the study, limitations and recommendations for future researches are approached in the present investigation

Comportamento do consumidor: um estudo do mercado imobiliário em condomínios verticais fechados na região metropolitana de Natal

The research in question looked for to establish the relation between the motivation (of the proprietor of apartment) to change itself of another one apartment, in closed vertical condominium (residential mobility) in the period of the recognition of the necessity, and the satisfaction with the apartment after consume. The universe or the population chosen for the development of the study was of proprietors of apartment in vertical condominiums located in the region metropolitan of Natal. The analysis of data was made using the techniques of linear regression and logistic regression between variables. The linear regression found relations between the motivations for housing change and the satisfaction in after consume with some attributes of the apartment. The logistic regression showed that relations between the motivations for change and the general satisfaction to the apartment exist as a whole, in the period after consumes. With regard to the motivation to change itself of a apartment for another one, some reasons shown more motivation them the others. The research found different degrees of satisfaction with certain characteristics of the apartment and degrees of no satisfaction with others. Finally the results of the research had contributed for the reply of the problem that guided the present study, therefore had obtained in such a way to find how much logistic not linear relations between the two periods purchase (recognition of the necessity and evaluation after consume) and had elucidated the process that goes since the choice the product until the satisfaction of the necessities

análise experimental do efeito da diversificação em carteiras de ações: a relação entre risco e quantidade de ativos sob a ótica da estratégia ingênua

The objective is to analyze the relationship between risk and number of stocks of a portfolio for an individual investor when stocks are chosen by "naive strategy". For this, we carried out an experiment in which individuals select actions to reproduce this relationship. 126 participants were informed that the risk of first choice would be an asset average of all standard deviations of the portfolios consist of a single asset, and the same procedure should be used for portfolios composed of two, three and so on, up to 30 actions . They selected the assets they want in their portfolios without the support of a financial analysis. For comparison we also tested a hypothetical simulation of 126 investors who selected shares the same universe, through a random number generator. Thus, each real participant is compensated for random hypothetical investor facing the same opportunity. Patterns were observed in the portfolios of individual participants, characterizing the curves for the components of the samples. Because these groupings are somewhat arbitrary, it was used a more objective measure of behavior: a simple linear regression for each participant, in order to predict the variance of the portfolio depending on the number of assets. In addition, we conducted a pooled regression on all observations by analyzing cross-section. The result of pattern occurs on average but not for most individuals, many of which effectively "de-diversify" when adding seemingly random bonds. Furthermore, the results are slightly worse using a random number generator. This finding challenges the belief that only a small number of titles is necessary for diversification and shows that there is only applicable to a large sample. The implications are important since many individual investors holding few stocks in their portfolios