940 resultados para correlation coefficient analysis


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An analytical procedure based on manual dynamic headspace solid-phase microextraction (HS-SPME) method and the conventional extraction method by liquid–liquid extraction (LLE), were compared for their effectiveness in the extraction and quantification of volatile compounds from commercial whiskey samples. Seven extraction solvents covering a wide range of polarities and two SPME fibres coatings, has been evaluated. The highest amounts extracted, were achieved using dichloromethane (CH2Cl2) by LLE method (LLECH2Cl2)(LLECH2Cl2) and using a CAR/PDMS fibre (SPMECAR/PDMS) in HS-SPME. Each method was used to determine the responses of 25 analytes from whiskeys and calibration standards, in order to provide sensitivity comparisons between the two methods. Calibration curves were established in a synthetic whiskey and linear correlation coefficient (r ) were greater than 0.9929 for LLECH2Cl2LLECH2Cl2 and 0.9935 for SPMECAR/PDMS, for all target compounds. Recoveries greater than 80% were achieved. For most compounds, precision (expressed by relative standard deviation, R.S.D.) are very good, with R.S.D. values lower than 14.78% for HS-SPME method and than 19.42% for LLE method. The detection limits ranged from 0.13 to 19.03 μg L−1 for SPME procedure and from 0.50 to 12.48 μg L−1 for LLE. A tentative study to estimate the contribution of a specific compound to the aroma of a whiskey, on the basis of their odour activity values (OAV) was made. Ethyl octanoate followed by isoamyl acetate and isobutyl alcohol, were found the most potent odour-active compounds.

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Burnout is a psychological syndrome triggered in response to continuous exposure to interpersonal stressors. It is considered a multifactorial construct, which is commonly characterized by three dimensions: emotional exhaustion, dehumanization, and lack of personal accomplishment.This study aimed to verify if the three characteristics of burnout (exhaustion, lack of dehumanization and personal accomplishment) are present in people working as guides Tourism in Natal - RN. It is a descriptive and quantitative study. 109 subjects were surveyed. Data collection was done through the use of questionnaires, the instrument used was the characterization of the Burnout Scale (ECB) created and validated in Brazil by Trocoli and Tamayo (2000). In order to analyze data we used descriptive statistics, analysis of core measures, exploratory and confirmatory factor analysis, reliability analysis, cluster analysis, multiple discriminant and Spearman correlation. Factor analysis identified four factors that explain 58.3% of the total variance. Those factors were named exhaustion, deception, avoidance, and dehumanization. The reliability of the instrument, as measured by Cronbach's Alpha was 0.918, which is considered excellent reliability. The 109 subjects were grouped into three cluster, which had the deception, avoidance, and dehumanization as discriminant. It is possible to conclude that the characteristics of burnout syndrome are present in the studied population where 19 people are on the high level of burnout, moderate in 32 and 56 in the light. The correlations between socio-demographic variables studied and the dimensions of burnout, were few and weak. The variable leave for health reasons in the study appeared to be related to feelings of exhaustion and avoidance behavior appeared related to younger individuals and who work only in the activity of Receptive Tourism Guide. Verification of the incidence of burnout in individuals surveyed suggest the need to adopt intervention strategies are individual, organizational and / or combined

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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High carotid artery resistance indices in the elderly arise mainly as a result of harmful daily lifestyle behavior and poor eating habits. The aim of this multidisciplinary study was to assess and correlate carotid artery resistance and functional autonomy in elderly women. A descriptive, exploratory cross-sectional study was conducted with a sample comprising 27 women, enrolled in pastoral programs in the city of Teresina, Brazil. Carotid artery resistance was assessed by a high-resolution Doppler ultrasound device and functional autonomy was evaluated through five protocol tests of the Latin American Development Group for the Elderly (GDLAM), simulating activities of daily life. The data were analyzed by the Shapiro-Wilk test and the correlation by Spearman s test, considering a p-value of <0.05. The sample consisted of women with mean age and standard deviation of (68.67 ± 4.52) years, respectively and carotid resistance index of (0.71 ± 0.07). The general index value of functional autonomy classified the elderly of the study group as weak in the performance of activities of daily living (30.46 ± 6.31). The general index of functional autonomy showed a high level of sedentary behavior in the group studied (p < 0.01). The sample was classified as weak in the performance of activities of daily life. The correlation coefficient between the carotid resistance index and the general GDLAM index was r = 0.998 and p = 0.000, showing a significant correlation. The elderly women assessed had a high carotid artery resistance index and low functional autonomy; a positive correlation was found between the dependent variables studied. To perform this study we formed a team composed of a nurse, who helped in organizing the sample and performing the examinations; a radiologist, who conducted the Doppler examinations; an angiologist, who collaborated in interpreting examination data; in addition to two physical education professors and two physical therapists, who applied the functional autonomy tests and conducted the 34 research along elderly health lines, contributing thus to the multidisciplinary character, fundamental for carrying out the study

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This study aimed at assessing the interobserver reliability of the Brazilian-Portuguese version of the Berg Balance Scale (BBS). The assessment was made by physiotherapists with extensive or little clinical experience in non-institutionalized elderly individuals. Participants comprised 12 elderly subjects (10 women and 2 men) with mean ages of 75.8 ± 8.4 years (range = 63-87) and 18 physiotherapists with varying clinical experience. Inter-examiner reliability obtained for each scale item yielded weighted kappa value > 0.75 in 11 of the 14 items (varying from 0.37 to 1.0). The intra-class correlation coefficient (ICC) for the total sum of BBS scores between the two groups of physiotherapists was 0.996 (95% confidence interval, 0.987 0.999) with a Cronbach alpha coefficient of 0.996. We found no difference between the rater groups when we compared the sum score means obtained with the student s T-test (p = 0.86). Although some items had low reliability values, in general our results suggest that the Brazilian Version of the BBS showed good levels of interrater reliability and agreement when used by physiotherapists with different clinical practice levels and without previous training on non-institutionalized elderly patients. We concluded that the BBS can be useful as an important evaluation instrument on a protocol for Rehabilitation clinics. It may be used by various health professionals, as: Physicians, Physical therapists, Physical educators, Occupational therapists, Nurses and Phonoaudiologists, so confirming the interdisciplinary character of this study

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Com o objetivo de obter uma equação matemática que, através de parâmetros lineares dimensionais das folhas, permitisse a estimativa da área foliar de Cissampelos glaberrima, estudaram-se relações entre a área foliar real (Sf) e os parâmetros dimensionais do limbo foliar, como o comprimento ao longo da nervura principal (C) e a largura máxima (L) perpendicular à nervura principal. As equações lineares simples, exponenciais e geométricas obtidas podem ser usadas para estimação da área foliar da falsa parreira-brava. do ponto de vista prático, sugere-se optar pela equação linear simples envolvendo o produto C x L, usando-se a equação de regressão Sf = 0,7878 x (C x L), que equivale a tomar 78,78% do produto entre o comprimento ao longo da nervura principal e a largura máxima, com coeficiente de correlação de 0,9307.

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O desempenho germinativo de sementes de Dalbergia nigra (jacarandá-da-bahia) foi avaliado em laboratório e viveiro, com o objetivo de verificar a eficiência do teste de germinação em laboratório em predizer o comportamento de lotes de sementes em condições de viveiro. Para tanto sementes pertencentes a três lotes (anos de colheita: lote I - 1998, lote II - 1997 e lote III - 1994) foram utilizados para determinar os dados biométricos, teor de água, germinação, índice de velocidade e primeira contagem da germinação e porcentagem de plântulas normais em laboratório e emergência, índice de velocidade de emergência e porcentagem de plântulas normais em viveiro. Sementes pertencentes ao lote III apresentaram qualidade inferior aos lotes I e II, tanto em laboratório como em viveiro. Os altos valores do coeficiente de correlação simples entre as características avaliadas nas duas condições, evidenciam a eficiência do teste de germinação em laboratório em predizer o desempenho germinativo de sementes de jacarandá-da-bahia em viveiro.

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Este trabalho teve por objetivo construir tabelas de vida ecológica para Bemisia tabaci (Genn.) biótipo B em soja. Para isso realizaram-se sucessivas infestações artificiais em plantas de soja, Glycine max (L.) Merrill, cultivar FT 2000. As amostragens foram realizadas retirando-se 10 folhas ao acaso com intervalos de três dias, durante oito gerações da mosca branca. O número de insetos vivos, mortos, parasitados e a distribuição etária foi registrado para cada folha amostrada. No presente trabalho os coeficientes de correlação para a mortalidade de ovos (0,1954), ninfas de 1º ínstar (0,5610) e pupas (0,6168), não foram significativos, porém as ninfas de 2º e 3º ínstar apresentaram coeficientes significativos de 0,7978 e 0,8641, respectivamente. No entanto o fator chave não foi identificado. O parasitóide Encarsia spp., apresentou-se como fator de mortalidade importante na fase de 'pupa' de B. tabaci biótipo B, porém o coeficiente de correlação não foi significativo.

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In the present study we evaluated the precision of the ELISA method to quantify caffeine in human plasma and compared the results with those obtained by gas chromatography. A total of 58 samples were analyzed by gas chromatography using a nitrogen-phosphorus detector and routine techniques. For the ELISA test, the samples were diluted to obtain a concentration corresponding to 50% of the absorbance of the standard curve. To determine whether the proximity between the I50 of the standard curve and that of the sample would bring about a more precise result, the samples were divided into three blocks according to the criterion of difference, in modulus, of the I50 of the standard curve and of the I50 of the sample. The samples were classified into three groups. The first was composed of 20 samples with I50 up to 1.5 ng/ml, the second consisted of 21 samples with I50 ranging from 1.51 to 3 ng/ml, and the third of 17 samples with I50 ranging from 3.01 to 13 ng/ml. The determination coefficient (R² = 0.999) showed that the data obtained by gas chromatography represented a reliable basis. The results obtained by ELISA were also reliable, with an estimated Pearson correlation coefficient of 0.82 between the two methods. This coefficient for the different groups (0.88, 0.79 and 0.49 for groups 1, 2 and 3, respectively) showed greater reliability for the test with dilutions closer to I50.

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Com este trabalho, o objetivo foi estimar a radiação fotossinteticamente ativa (PAR) e correlacioná-la com a massa de matéria seca (MMSPA) da grama-esmeralda (Zoysia japonica Steud.), em superfícies com diferentes exposições e declividades. A pesquisa foi desenvolvida na Bacia Hidrográfica Experimental do Departamento de Engenharia Rural, FCAV/UNESP, Brasil, onde foram utilizadas as superfícies (H; 10 N; 30 N; 50 N; 10 S; 30 S; 50 S; 10 L; 30 L; 50 L; 10 O; 30 O e 50 O). Para a obtenção da radiação solar global, foi instalada uma estação meteorológica automatizada, onde a PAR (variável dependente) foi obtida por meio da equação y = a + bx, e a radiação global foi a independente. Para comparação de médias da MMSPA, utilizou-se o teste de Tukey, a 5% de probabilidade, e para verificar a relação existente PAR/MMSPA, o coeficiente de correlação linear simples. O resultado mostrou que o acúmulo desses efeitos na PAR aumenta com a exposição norte e decresce com a sul, sendo a exposição 50 N a mais indicada para taludes, não havendo correlação entre a PAR e a MMSPA para as superfícies avaliadas para o período estudado.

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O conhecimento do potencial da mineralização dos compostos orgânicos nitrogenados do solo é fundamental para o uso eficiente do N em sistemas de produção agrícola. Com o objetivo de avaliar a atividade de proteases e suas relações com os teores de diferentes formas de N em Latossolo Vermelho distrófico cultivado com laranjeira, foram coletadas amostras de solo em duas profundidades (0-10 e 10-20 cm), na linha de projeção da copa e nas entrelinhas, nos meses de novembro e dezembro/98, fevereiro e março/99. em março/99, época recomendada para a diagnose foliar, também foram coletadas amostras de folhas. As amostras de solo foram avaliadas com relação à atividade de proteases e aos teores de N-amoniacal, N-nitrato, N-total, N-amoniacal obtido após incubação anaeróbia (N-pot) e N-amoniacal extraído por solução de CaCl2 sob autoclavagem (N-autoclave). Nas amostras de folha, determinou-se o teor de N-total. A atividade de proteases foi influenciada pelo local e pela profundidade de amostragem, tendo sido mais elevada na linha de projeção da copa e profundidade de 0-10 cm. A aplicação de fertilizante orgânico causou aumento na atividade de proteases, principalmente na camada de 0-10 cm. O coeficiente de correlação entre atividade de proteases e outros métodos para avaliação da disponibilidade de N dependeu da época, do local e da profundidade de amostragem. A correlação entre o N-foliar, obtido na época indicada para diagnose foliar, a atividade de proteases e as demais formas para avaliar disponibilidade de N (N-amoniacal, N-nitrato, N-autoclave e N-pot) variou com a época de amostragem. A atividade de proteases foi positiva e altamente correlacionada com o N-foliar, obtido na época indicada para fins de diagnose foliar, para amostras de terra retiradas nas entrelinhas (0-10 cm), no mês de dezembro/1998.

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O perímetro escrotal (PE) de 202 touros jovens da raça Nelore, sem experiência sexual prévia, classificados pela Associação Brasileira de Criadores de Zebu como superiores ou elite, foi medido aos 7, 12, 18 e 28 meses de idade, aproximadamente. Após a última medição, eles foram submetidos ao teste de libido e procedeu-se à colheita de sêmen por eletroejaculação, seguida de avaliação andrológica. As medidas do PE aos 7, 12, 18 e 28 meses foram de 18,30; 22,29; 27,54 e 33,26cm, respectivamente. Os coeficientes de correlação simples entre estas medidas variaram de 0,35 a 0,53. O coeficiente de correlação entre PE aos 28 meses e peso corporal na mesma idade foi de 0,43. A correlação entre a nota da libido e o perímetro escrotal medido aos l8 meses foi de 0,15 e entre aquela e o perímetro escrotal aos 28 meses foi de 0,13. Observou-se elevado crescimento do perímetro escrotal entre o 7º e 18º meses de idade. Utilizou-se o método de quadrados mínimos para analisar a libido, incluindo ano de nascimento como efeito fixo e como covariáveis os efeitos lineares da idade e peso no momento da avaliação e medidas de perímetro escrotal aos 7, l2, l8 e 28 meses. Cada covariável foi retida de forma seqüencial obtendo-se vários modelos de análises e as somas de quadrados foram decompostas de forma seqüencial e parcial. O ano de nascimento, a idade e o perímetro escrotal aos 18 meses de idade afetaram significativamente a libido. Os coeficientes de correlação entre a libido e concentração espermática, motilidade, peso e idade do animal no momento da avaliação foram de 0,34, 0,l6, 0,38 e 0,35, respectivamente.

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This Master of Science Thesis deals with a BSC modeling for higher education institution focusing on private institution in the Brazilian context. It‟s accomplished a literature review in order to understand the BSC and its application to for profit and non for profit organizations and as a main result it is proposed a BSC conceptual model with a new perspective (Government) and a change in the hierarchy of the main BSC perspective equaling financial to customer/society. Taking the national higher education assessment system of Education Ministry indicators a model is deployed and the relations between the indicators are measured with the Pearson correlation coefficient. As a result a model emerges with sound relations of indicators but a improvement in the financial indicators is needed

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Modern wireless systems employ adaptive techniques to provide high throughput while observing desired coverage, Quality of Service (QoS) and capacity. An alternative to further enhance data rate is to apply cognitive radio concepts, where a system is able to exploit unused spectrum on existing licensed bands by sensing the spectrum and opportunistically access unused portions. Techniques like Automatic Modulation Classification (AMC) could help or be vital for such scenarios. Usually, AMC implementations rely on some form of signal pre-processing, which may introduce a high computational cost or make assumptions about the received signal which may not hold (e.g. Gaussianity of noise). This work proposes a new method to perform AMC which uses a similarity measure from the Information Theoretic Learning (ITL) framework, known as correntropy coefficient. It is capable of extracting similarity measurements over a pair of random processes using higher order statistics, yielding in better similarity estimations than by using e.g. correlation coefficient. Experiments carried out by means of computer simulation show that the technique proposed in this paper presents a high rate success in classification of digital modulation, even in the presence of additive white gaussian noise (AWGN)