314 resultados para correlation coefficient


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The equations and extrapolation use to localities whose characteristics of soil and climate, even if partial, distinguish the town to which they were generated, still permeate in studies to estimate the rainfall erosivity (EI 30). This work has objective to propose and validate mathematical equations to estimate the rainfall erosivity of two cities of Sao Paulo State's. The adjusted to estimate obtaining and validate data of equations of erosivity (EI 30) according to values of coefficient of rain (Rc) were obtained from pluviographic and pluviometric rainfall data, respectively, using of distinct historical rainfall series. Mutiple comparisions test and confidence intervals were performed to compare absolute average of EI 30, pluviometric data (Pp), and Rc. The correlation between EI 30 and Rc was verified by of Pearson correlation coefficient. Test of the hypothesis of equality between population variance was used to compare the equations. Pluviometrics data of historical series rainfall data different than those that the models were generated were used to validate and to assess the performance of the equations, proposed of this study and compare them with another equation already consolidated in literature. The results show that for the conditions under which the study was conducted, the simple linear equations, shown to be the most appropriate to estimate the rainfall erosivity these two cities. According to the test of the hypothesis of equality variances between populations, the equations adjusted for each city differ statistically so that the rainfall erosivity of each city must be estimated by their respective equation.

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Objective: The objective of this study is to characterize the assistance and analyze patient's adherence to nutritional follow-up while in the waiting line for bariatric surgery in a multidisciplinary, secondary healthcare outpatient clinic. Methods: This retrospective study was based on the nutritional records of 59 patients subjected to bariatric surgery at the Hospital das Clinics de Botucatu, from 2001 to 2008. The population studied was distributed into 8 groups and analyzed according to follow-up duration. The analysis took into account the evolution of body weight and the number of follow-up visits in a given period. The Kruskal-Wallis test was used to compare data between groups while Spearman's coefficient was used to test correlations. Results: Among the 59 studied patients, 42 (71.2%) returned to the clinic at least once in six months. Of these, 67.8% lost weight while in the waiting line and 27.1% of them lost more than 10% of their body weight. The greatest weight losses in the preoperative period were found in the groups that had more than six months of nutrition follow-up. There was a mean delay of three months between return visits, which could have contributed to the low adherence to follow-up. Conclusion: The patients in the waiting line for surgery analyzed in this study presented low adherence to the long-spaced return visits. The greatest weight losses were observed in groups that had been followed for more than six months. This shows that, to achieve the desired weight loss and an adequate education process before surgery, at least six months of follow-up and regular visits are necessary.

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Aim: To assess the bone mineral density on conventional and digitized images, comparing whether different parameters of digitization and storage change these values. Methods: Twenty radiographs were taken from five partially dentulous dry mandibles with an aluminum 7-mm stepwedge placed on the superior edge of the film. After processing, the films were digitized with a resolution of 600 and 2,400 d.p.i. and saved as TIFF and JPEG files. On every conventional and digitized image, circular regions of interest were selected for densitometry and radiographic contrast analysis. Results: Pearson's correlation coefficient showed a significant and strong mean gray values association between digitized and conventional images, differing from radiographic contrast that did not show a significant association. ANOVA did not reveal a statistically significant difference in bone density and radiographic contrast among the four digitized image groups, but the conventional image contrast was significantly lower. Conclusions: Bone mineral density did not differ in both conventional and digitized images. The parameters of image compression and resolution, tested in this study, did not change the results of densitometry and digitization process increased the radiographic contrast.

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Cognitive changes in normal aging can be similar to the alterations that take place in the initial stages of a dementia process. Longitudinal studies can provide a better understanding of this progression. Objectives: To evaluate the cognitive and functional evolution of community-dwelling individuals without dementia through a three-year longitudinal study. Methods: 168 individuals were evaluated in 2006. Three years later in 2009, 73 of these subjects were reevaluated as regards cognition and functionality using the Mini Mental State Examination (MMSE), Brief Cognitive Battery (BCB) and the Pfeffer Functional Activities Questionnaire. The statistical analysis included descriptive measurements, the Wilcoxon's test for intra-group comparison, and the Spearman's correlation coefficient test for comparing cognitive and functionality scores. Results: After three years, the Wilcoxon's test showed a discreet yet significant cognitive decline (MMSE: -0.7 points; p=0.02; Z= -2.29; and global score on the BCB: +3.6 points; p=0.02; Z= -2.29), in addition to functional decline (Pfeffer: +0.7 points; p= 0.001; Z= -3.38). Conclusions: After three years of follow-up we observed a discreet yet significant functional and cognitive decline in the subjects. Longitudinal cognitive screening represents an important strategy in the early identification of changes from normal conditions to a dementia process.

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Objective: To evaluate the intraexaminer reproducibility of static anthropometric measurements of undergraduate dental students as well as the characteristics and regulating measurements of the dental stools used by them. Methods: Forty volunteers and 6 types of dental stools were evaluated. For the anthropometric measurements the employed equipments were: an adapted office chair, aflexible measuring tape with two adapted rods, a metallic device with a 90 degree central angle, string, a 35 x 24 cm rectangular wooden board, isolating tape and crepe tape. In order to standardize the position of the adapted office chair and the volunteers' feet, the floor was marked with the isolating and crepe tapes. A string was attached to the waist of each volunteer to mark the area corresponding to the kidney region making it possible to measure the seat-renal region area. The examined anthropometric measurements were height, trunkcephalic heigh, sacral-popliteal distance (OK?), hip width, popliteal height and the seat-renal region height. The evaluated characteristics of the dental stools relative to the seat were depth, horizontal width and minimum/maximum height. The back of the dental stool was evaluated as for the minimum/ maximum height adjustment. The anthropometric and dental stool measurements were obtained by a single examiner at two moments with a 1-week interval between the evaluations. Intra-class correlation coefficient (ρ) was used to estimate the intraexaminer reproducibility. Results: Excellent reproducibility was observed for all anthropometric measurements obtained (ρ=0.99) as well as for all dental stools evaluated (ρ=0.99). Conclusion: The method used to obtain the anthropometric and dental stools measurements was reproducible and can be used reliably.

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Background and aims. Disease is influenced by the nutritional status of the individual. We have assessed the relationship between nutritional status and food intake among recently hospitalised older people. Methods. A cross-sectional study was undertaken with 240 older people in a hospital that provides care for the public and private healthcare systems. Nutritional status was classified by the MNA (Mini Nutritional Assessment) into: malnourished, risk of malnutrition and without malnutrition. Food intake was estimated by the reported food intake during a typical day. The Kruskal-Wallis test was used to compare the medians and the correlation coefficient of Spearman to verify the relationship between the consumption of energy, protein and vitamin C and MNA scores. Results. 33.8% were classified as adequate regarding nutritional status; 37.1% were classified as being at risk of malnutrition and 29.1% were classified as malnourished. The malnourished individuals reported significantly less energy and nutrient intake than those at risk of malnutrition or those without malnutrition (P=0.001). Not all nutrient intake, just some (iron, cholesterol and fibre), were lower in malnourished people. Conclusions and implications for practice. Deterioration of the nutritional status of older people is accompanied by a reduction in energy and some nutrient intake. The investigation of food intake in older people could provide important information about nutritional risk. © 2010 Blackwell Publishing Ltd.

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Albumin concentrations in female Bronze turkeys were compared using agarose gel electrophoresis (AGE) and the bromocresol green (BCG) dye-binding method. The correlation coefficient observed for albumin in the BCG and AGE methods was low, and statistical differences were observed at paired t test (p < 0. 0001). Compared with electrophoresis, the BCG-binding method yielded significantly lower albumin values for female turkeys during laying season. © 2011 Springer-Verlag London Limited.

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Influence of cutting instruments and The aim of this study was to analyze the hybrid layer in noncarious dentin prepared by different cutting instruments and restored with composite resin. The cavities were randomly prepared in 40 specimens using a high-speed diamond bur (KG Sorensen 1013) and an ultrasonic tip (CVDentus C22). The cavities were restored with composite resin by varying the adhesive system between the Adper™ Single Bond (2 x 1 system, primer+adhesive) and the Prompt L-Pop™ (3 x 1 system, self-etching). The restorations were hemisected longitudinally and analyzed in the SEM (Scanning electron microscopy) in order to evaluate the hybrid layer and resinous tags characteristics, using scores ranging from 1 to 6. The Pearson test revealed a high correlation coefficient and good significance levels for both intra- and inter-raters values (r=0.90). The data were statistically analyzed using the Mann-Whitney test (P≤0.05). A larger proportion of regular hybrid layers with numerous tags were observed in the dentin prepared using the high-speed diamond burs and restored with a 2 × 1 adhesive system. Alternatively, the 3 × 1 adhesive system promoted the generation of a thin hybrid layer with few tags. After preparation using an ultrasonic tip revealed few or no tags after the preparation and 2 × 1 or 3 × 1 adhesive system application. The high-speed diamond burs produced a dentin surface that was more favorable to restorative material adhesion than the ultrasonic tips, regardless of the adhesive system used.

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The aim of this study was to analyze the evolution of natural honey production in Brazil, as well as the Brazilian performance in the international markets and their own consumption behavior of natural honey in the domestic market. For this study, we used descriptive analysis of time series information, data production and export of natural honey understood, respectively, for the periods 1999 to 2010. To analyze the correlation between the series of apparent consumption per capita (variable X) and the international price data (variable Y), we used the statistical analysis of the correlation coefficient of Pearson (CP). Main results revealed that the Brazilian production of natural honey has more than doubled in the last decade, while the Northeast region was the largest contributor to this performance. This increase in the production was mainly directed towards supplying the international market, which currently consumes more than half of Brazilian production. It is true that the change in the international market price has a direct effect on domestic supply, but the Brazilian domestic market has potential for increasing effective consumer who deserves to be better exploited; it implies to pay attention to the supply of quality natural honey, quantity and regularity.

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The validation of a microbiological assay, applying agar diffusion method for determination of the active of cefuroxime in power for injection, is described. Using a strain of Micrococcus luteus ATCC 9341 as the test organism, cefuroxime was measured in concentrations ranging from 30.0 to 120.0 μg/mL. The method validation showed that it is linear (r = 0.9999), precise (relative standard deviation = 0.37%) and accurate (it measured the added quantities). Microbiological assay is satisfactory for quantitation of cefuroxime in powder for injection and the validity of the proposed bioassay, which is a simple and a useful alternative methodology for cefuroxime determination in routine quality control.

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Background: Metabolic and morphological changes associated with excessive abdominal fat, after the introduction of Antiretroviral Therapy, increase the risk of cardiovascular disease in people living with HIV/AIDS(PLWHA). Accurate methods for body composition analysis are expensive and the use of anthropometric indices is an alternative. However the investigations about this subject in PLWHA are rare, making this research very important for clinical purpose and to advance scientific knowledge. The aim of this study is to correlate results of anthropometric indices of evaluation of body fat distribution with the results obtained by Dual-energy X-Ray Absorptiometry(DEXA) , in people living with HIV/AIDS. Methods. The sample was of 67 PLWHA(39 male and 28 female), aged 43.6+7.9 years. Body mass index, conicity index, waist/hip ratio, waist/height ratio and waist/thigh were calculated. Separated by sex, each index/ratio was plotted in a scatter chart with linear regression fit and their respective Pearson correlation coefficients. Analyses were performed using Prism statistical program and significance was set at 5%. Results: The waist/height ratio presented the highest correlation coefficient, for both male (r=0.80, p<0.001) and female (r=0.87, p <001), while the lowest were in the waist/thigh also for both: male group (r=0.58, p<0.001) and female group (r=0.03, p=0.86). The other indices also showed significant positive correlation with DEXA. Conclusion: Anthropometric indices, especially waist/height ratio may be a good alternative way to be used for evaluating the distribution of fat in the abdominal region of adults living with HIV/ADIS. © 2012 Segatto et al.; licensee BioMed Central Ltd.

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A voltammetric method for the determination of ethyl acetate in ethanol fuel using a Fe3+/Nafion®-coated glassy carbon electrode (GCE) is proposed. The ethyl acetate present in the ethanol fuel was previously converted to acetohydroxamic acid via pretreatment with hydroxylamine chloride. The acetohydroxamic acid promptly reacted with the iron (III) present in the film, producing iron (III) acetohydroxamate, which presents a well-defined voltammetric peak current at -0.02 V. Optimization of the voltammetric parameters for the cyclic, linear sweep, square wave, and differential pulse modalities was carried out for this chemically-modified electrode. Square wave voltammetry afforded the best response for acetohydroxamic acid detection. The analytical curve for this species was linear from 9 to 100 μmol L 1 according to the following equation: ip (μA) = 0.27 + 2.55Cacetohydroxamic acid (μmol L 1), with linear correlation coefficient equal to 0.993. The technique presented limit of detection equal to 5.3 μmol L 1 and quantification limit of 17.6 μmol L 1. The proposed method was compared to the official method of ethyl acetate analysis (Gas Chromatography), and a satisfactory correlation was found between these techniques. © 2012 Elsevier Ltd. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Poor posture control has been associated with an increased risk of falls and mobility disability among older adults. This study was conducted to assess the test-retest reliability and sensitivity to group differences regarding the time-limit (TLimit) of one-leg standing and selected balance parameters obtained with a force platform in older and young adults. A secondary purpose was to assess the relationship between TLimit and these balance parameters. Twenty-eight healthy older adults (age: 69±5years) and thirty young adults (age: 21±4years) participated in this study. Two one-leg stance tasks were performed: (1) three trials of 30s maximum and (2) one TLimit trial. The following balance parameters were computed: center of pressure area, RMS sway amplitude, and mean velocity and mean frequency in both the anterio-posterior and medio-lateral directions. All balance parameters obtained with the force platform as well as the TLimit variable were sensitive to differences in balance performance between older and young adults. The test-retest reliability of these measures was found to be acceptable (ICC: 0.40-0.85), with better ICC scores observed for mean velocity and mean frequency in the older group. Pearson correlations coefficients (r) between balance parameters and TLimit ranged from -0.16 to -0.54. These results add to the current literature that can be used in the development of measurement tools for evaluating balance in older and young adults. © 2013 Elsevier Ltd.

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A novel composite formed by interaction of a octa(3-chloropropyl)octasilsesquioxane modified with Purpald®, and its subsequent reaction with silver and hexacyanoferrate (III) (AgHSP), was synthesized and initially characterized by Fourier transform infrared spectra (FTIR) and cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with AgHSP, showed one redox couple with formal potential Eθ'=0.64V (vs Ag/AgCl, KNO3, 1.0 mol L-1; v = 20 mV s-1), attributed to the Fe2+(CN)6/ Fe3+(CN)6 process. The redox couple presents an electrocatalytic response for determination of sulfite. The modified electrode showed a linear response from 7.0×10-5 to 1.0×10-3 mol L-1 with the corresponding equation Y(μA) = 18.05 + 29.983×103 [sulfite], and a correlation coefficient of r=0.999. The method showed a detection limit of 0.115×10-4 mol L-1 with a relative standard deviation of ± 4% (n = 3) and amperometric sensitivity of 29.983×10-3A mol L-1. The modified electrode showed a excellent stability and good reproducibility during experiments. © 2013 by ESG.