Análise de sedimento de fundo: uma amostragem representativa do estuário Potengi/RN

The aim of this study is to quantify the presence of major and minor elements in the sediments of estuary Potengi. Four georeferenced sampling points were used in the study, at which sediment samples were collected in the channel of the river and on the right and left banks. In addition, dissolved oxygen, salinity and water conductivity were taken in situ at the time of sample collection. The percentage of organic matter, determined by gravimetry, and granulometric analysis of the sediment samples were conducted in the laboratory. To quantify the major and minor elements a prior test to open the sample was conducted with standard NIST 1646ª estuarine sediment to choose the best methodology to be adopted. The sediment samples were dissolved in microwaves with nitric acid and chloridric acid, according to methodology proposed by US EPA 3051ª. Quantitative analyses of the elements Al, Fe, Cd, Cr, Cu, Mn, Ni, Pb and Zn were conducted by inductively coupled plasma optical emission spectrometry (ICPOES). The results showed that the partial concentrations of the elements analyzed are below average worldwide shale levels, the standard described by Turekian and Wedepohl (1961)

Grafico misto de controle da media com amostragem em dois estagios

This paper proposes a new control chart to monitor a process mean employing a combined npx-X control chart. Basically the procedure consists of splitting the sample of size n into two sub-samples n1 and n2 determined by an optimization search. The sampling occur in two-stages. In the first stage the units of the sub-sample n1 are evaluated by attributes and plotted in npx control chart. If this chart signs then units of second sub-sample are measured and the monitored statistic plotted in X control chart (second stage). If both control charts sign then the process is stopped for adjustment. The possibility of non-inspection in all n items may promote a reduction not only in the cost but also the time spent to examine the sampled items. Performances of the current proposal, individual X and npx control charts are compared. In this study the proposed procedure presents many competitive options for the X control chart for a sample size n and a shift from the target mean. The average time to sign (ATS) of the current proposal lower than the values calculated from an individual X control chart points out that the combined control chart is an efficient tool in monitoring process mean.

O paradoxo da superdifusão de uma caminhada aleatória com memória exponencial

The random walk models with temporal correlation (i.e. memory) are of interest in the study of anomalous diffusion phenomena. The random walk and its generalizations are of prominent place in the characterization of various physical, chemical and biological phenomena. The temporal correlation is an essential feature in anomalous diffusion models. These temporal long-range correlation models can be called non-Markovian models, otherwise, the short-range time correlation counterparts are Markovian ones. Within this context, we reviewed the existing models with temporal correlation, i.e. entire memory, the elephant walk model, or partial memory, alzheimer walk model and walk model with a gaussian memory with profile. It is noticed that these models shows superdiffusion with a Hurst exponent H > 1/2. We study in this work a superdiffusive random walk model with exponentially decaying memory. This seems to be a self-contradictory statement, since it is well known that random walks with exponentially decaying temporal correlations can be approximated arbitrarily well by Markov processes and that central limit theorems prohibit superdiffusion for Markovian walks with finite variance of step sizes. The solution to the apparent paradox is that the model is genuinely non-Markovian, due to a time-dependent decay constant associated with the exponential behavior. In the end, we discuss ideas for future investigations.

Efeito agudo do exercício físico associado a praxias ideomotoras sobre as concentrações séricas de cortisol e memória declarativa em indivíduos com idade entre 51 e 74 anos

Introduction: Several modifications are identified as aging, causing more or less limitation imposed by over the years. Among these, one can highlight the different degrees of cognitive decline, particularly memory that can involve the daily activities and the subject functionality. Studies have shown an association between levels of serum cortisol and stress imposed by the exercise on this. However, there are few studies that references the performance on cognitive aspects of declarative memory and cortisol on the exercise in the water with automatic and práxicos movements and moderate. Objective: Check the effect based on the acute physical exercise and práxicos automatic movements on the performance of visual declarative memory and in serum cortisol in subjects aged between 51 and 74 years. Materials and Methods: It builds a survey characterized as cross with a first sample of 32 physically active subjects aged between 51 and 74 years, divided into two exercise groups (March of Automatic Group - MAG and the March of Praxis Group - MPG). We used a probabilistic and random sampling for sample selection. Used the MMSE (Mini Mental State Examination) to check the general cognitive status, visual acuity test - optotypes chart "E" Rasquin and was even used the declarative visual memory test proposed by Nitrini and collaborators (1994), applying before motor stimulation and immediately after, and the day of blood collection with 2 ml for analysis of cortisol hormone. The normality and homogeneity were verified from the Shapiro-Wilk and Levene tests. Thus we adopted a descriptive statistics to characterize the sample. The Split-Plot ANOVA was used along with the paired t-test to verify the identified differences. We adopted a significance level of p <0.05. Results: It was observed that the groups (MAG and MPG) and the anthropometric variables, perceived exertion, education, cognitive assessment and visual acuity showed no significant differences (p > 0.05), showing that the groups are homogeneous, with variables and similar means. After the stimulation session, lasting 30 min, it was observed that the amount of hits for Δ of declarative memory questionnaire visual images increased, presenting significant for both groups (MAG, p < 0.001; MPG, p = 0.042). The same was observed for cortisol concentration with a reduction in the levels immediately after the stimulus (MAG and MPG, p < 0.001). Conclusion: The results showed that the exercises proposed in its acute effect provide significantly memories of gains and also showed a reduction in cortisol levels.

Antecedentes do engajamento em boca a boca eletrônico positivo entre turistas

This study examined the influence of the tourism destination image as well as satisfaction and motivation in the intention of engaging in a positive electronic word of mouth (eWOM) by tourists through Facebook. In addition, it was also specifically expected to assess the sociodemographic profile and frequency of eWOM publications from those who answered the questions; it also assessed the adequacy of the manifested variables for composition of the following dimensions: Quality, Satisfaction, Image, Motivations and Positive Electronic Word of Mouth (eWOM). And finally, it analyzed a relational model where there are relationships between Quality, Satisfaction, Image and Motivations in the explanation of engagement in the Positive Electronic Word of Mouth (eWOM). With this aim it was conducted a study, based on a hypothetical-deductive logic, which was descriptive in relation to its goals. The analytical approach was quantitative (a survey). The sampling procedure was non-probabilistic, by the convenience method of sampling specifically, having the choice of the subject been made through the probabilistic systematic method, and using time as a factor of systematization in an attempt of making randomly the selection of the interviewed people. The study sample consisted of 355 tourists. The used instrument to collect information was the structured questionnaire whose answers were collected in the main points of entry, exit and rides of tourists on the Pipa’s Beach/RN. Data analysis was carried out using descriptive and multivariate statistics, mainly exploratory and confirmatory factor analysis and structural equation modeling. Among the main results, it was possible to confirm that the Motivations, Satisfaction and Image strongly affect the intention of engaging in positive electronic word of mouth (eWOM). Emphasis is given to the motivations, as they demonstrate bigger impact in explaining the dependent variable; they are followed by the satisfaction and the image. The latter, however, is inversely proportional. Among the motivations, the one with the highest percentage of variance were the social benefits sought by tourists; and presenting the same percentage appears the desire to help other tourists and to vent Positive Emotions. The manifested variables demonstrate to be fully acceptable to be taken as reflexes of their respective factors.

Avaliação da efetividade do Programa de Alimentação do Trabalhador

This study analyzed the Worker’s Healthy Eating Program in Rio Grande do Norte state (RN) to assess its possible impact on the nutritional status of the workers benefitted. To that end, we conducted a cross-sectional observational prospective study based on a multistage stratified random sample comparing 26 small and medium-sized companies from the Manufacturing Sector (textiles, food and beverages, and nonmetallic minerals) of RN, divided into two equal groups (WFP and Non WFP). Interviews were conducted at each company by trained interviewers from Tuesday to Saturday between September and December 2014. Data were collected on the company (characterization and information regarding the program’s desired results) and workers (personal and professional information, anthropometrics, health, lifestyle and food consumed the previous day). Population estimates were calculated for RN on the characteristics of workers and the study variables. The main variable was BMI. The secondary variables were waist circumference (WC), nutritional diagnosis, calorie intake, blood pressure, metabolic variables and lifestyle indicators. The statistical method used was hierarchical mixed effects linear regression for interval variables and hierarchical mixed effects logistic regression for binary variables. The variables measured in ordinal scales were analyzed by ordinal logistic regression adjusted for correlated variables, adopting robust standard errors. The results for interval variables are presented as point estimates and their 95% confidence intervals; and as odds-ratios and their 95% confidence intervals for binary variables. The Fisher’s exact and Student’s t-tests were used for simple comparisons between proportions and means, respectively. Differences were considered statistically significant at p<0.05. A total of 1069 workers were interviewed, of which 541 were from the WFP group and 528 from the Non WFP group. Subjects were predominantly males and average age was 34.5 years. Significant intergroup differences were observed for schooling level, income above 1 MW (minimum wage) and specific training for their position at the company. The results indicated a significant difference between the BMI of workers benefitted, which was on average 0.989 kg/m2 higher than the BMI of workers from the Non WFP group (p=0.002); and between the WC, with the waist circumference of WFP group workers an average of 1.528 cm larger (p<0.05). Higher prevalence of overweight and obesity (p<0.001) and cardiovascular risk (p=0.038) were recorded in the WFP group. Tests on the possible effect of the WFP on health (blood pressure and metabolic indicators) and lifestyle indicators (smoking, alcohol consumption and exercise) were not significant. With respect to worker’s diets, differences were significant for consumption of saturated fat (lunch and daily intake), salt (lunch, other meals and daily intake) and proteins (other meals and daily intake), with higher consumption of these nutrients in the WFP group. The study showed a possible positive impact of the WFP on nutritional status (BMI and WC) among the workers benefitted. No possible effects of the program were observed for the lifestyle indicators studied. Workers benefitted consumed less salt, saturated fat and protein. The relevance of the WFP is recognized for this portion of society and it is understood that, if the program can reach and impact those involved, the development of educational initiatives aimed at nutritional and food safety may also exert a positive influence.

Efeito de diferentes divisões territoriais na flutuação aleatória de indicadores socioeconômicos relacionados à determinação social da saúde

This research aimed to analyse the effect of different territorial divisions in the random fluctuation of socio-economic indicators related to social determinants of health. This is an ecological study resulting from a combination of statistical methods including individuated and aggregate data analysis, using five databases derived from the database of the Brazilian demographic census 2010: overall results of the sample by weighting area. These data were grouped into the following levels: households; weighting areas; cities; Immediate Urban Associated Regions and Intermediate Urban Associated Regions. A theoretical model related to social determinants of health was used, with the dependent variable Household with death and as independent variables: Black race; Income; Childcare and school no attendance; Illiteracy; and Low schooling. The data was analysed in a model related to social determinants of health, using Poisson regression in individual basis, multilevel Poisson regression and multiple linear regression in light of the theoretical framework of the area. It was identified a greater proportion of households with deaths among those with at least one black resident, lower-income, illiterate, who do not attend or attended school or day-care and less educated. The analysis of the adjusted model showed that most adjusted prevalence ratio was related to Income, where there is a risk value of 1.33 for households with at least one resident with lower average personal income to R$ 655,00 (Brazilian current). The multilevel analysis demonstrated that there was a context effect when the variables were subjected to the effects of areas, insofar as the random effects were significant for all models and with different prevalence rates being higher in the areas with smaller dimensions - Weighting areas with coefficient of 0.035 and Cities with coefficient of 0.024. The ecological analyses have shown that the variable Income and Low schooling presented explanatory potential for the outcome on all models, having income greater power to determine the household deaths, especially in models related to Immediate Urban Associated Regions with a standardized coefficient of -0.616 and regions intermediate urban associated regions with a standardized coefficient of -0.618. It was concluded that there was a context effect on the random fluctuation of the socioeconomic indicators related to social determinants of health. This effect was explained by the characteristics of territorial divisions and individuals who live or work there. Context effects were better identified in the areas with smaller dimensions, which are more favourable to explain phenomena related to social determinants of health, especially in studies of societies marked by social inequalities. The composition effects were better identified in the Regions of Urban Articulation, shaped through mechanisms similar to the phenomenon under study.

Crítica descentrada para o senso comum: amostragem da reflexão acerca da comunicação contemporânea realizada na Universidade Federal do Rio Grande do Norte

Crítica descentrada para o senso comum: MUNIZ, Euzébia Maria de Pontes Targino; DANTAS, Juliana Bulhões Alberto; ALBANO, Sebastião Guilherme (Orgs). Amostragem da reflexão acerca da comunicação contemporânea realizada na Universidade Federal do Rio Grande do Norte. Natal, RN: EDUFRN, 2012.