947 resultados para Multivariate analysis


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Geographic differentiation and sexual dimorphism in eighteen morphometric characters of Lutosa brasiliensis (Orthoptera: Henicidae) collected in eight localities of the State of São Paulo (Brazil) were analysed. A two-way Multivariate Analysis of Variance (MONOVA) was used to assess simultaneously the effects of sex and geographic location (plus their interaction) on morphometric variability. The spatial patterns of variation were analysed by Factor and Spatial Autocorrelation Analyses (Moran's I coefficient in four distance classes). Both indicate that the main direction of variation is, for males and females, a north-south cline in overall body size. In females, however, ovipositor length is not correlated with overall body size and displays a different pattern of variation over geographic space, indicating that distinct evolutionary forces produced the geographic differentiation in the species.

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The goal of this work was to establish comparisons among environmental degradation in different areas from Southern Spain (Gulf of Cadiz) and Brazil (Santos and Sao Vicente estuary), by using principal component analyses (PCA) to integrate sediment toxicity (amphipods mortality) and chemical-physical data (Zn, Cd, Pb; Cu, Ni, Co, V, PCBs, PAHs concentrations, OC and fines contents). The results of PCA extraction of Spanish data showed that Bay of Cadiz, CA-1 did not present contamination or degradation; CA-2 exhibited contamination by PCBs, however it was not related to the amphipods mortality. Ria of Huelva was the most impacted site, showing contamination caused principally by hydrocarbons, in HV-1 and HV-2, but heavy metals were also important contaminants at HV-1, HV-2 and HV-3. Algeciras Bay was considered as not degraded in GR-3 and -4, but in GR-3' high contamination by PAHs was found. In the Brazilian area, the most degraded sediments were found in the stations situated at the inner parts of the estuary (SSV-2, SSV-3, and SSV-4), followed by SSV-6, which is close to the Submarine Sewage Outfall of Santos - SSOS. Sediments from SSV-1 and SSV-5 did not present chemical contamination, organic contamination or significant amphipod mortality. The results, of this investigation showed that both countries present environmental degradation related to PAHs: in Spain, at Ria of Huelva and Gudarranque river's estuary areas; and in Brasil, in the internal portion of the Santos and Sao Vicente estuary. The same situation is found for heavy metals, since all of the identified metals are related to toxicity in the studied areas, with few exceptions (V for both Brazil and Spain, and Cd and Co for Brazilian areas). The contamination by PCBs is more serious for Santos and Sao Vicente estuary than for the investigated areas in Gulf of Cadiz, where such compound did not relate to the toxicity. (c) 2006 Elsevier Ltd. All rights reserved.

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Objectives: the evidence linking low levels of folic acid and orofacial clefting (OFC) is presently equivocal, There is stronger evidence for the role of folic acid supplementation in protection against the occurrence and recurrence of neural tube defects. The present investigation tested the hypotheses that cleft lip, cleft palate, or both are inversely associated with maternal intake of dietary and supplemental vitamins during the periconceptional period and first 4 months of pregnancy in a Brazilian population.Design: A population-based, case-control study of cleft lip with or without cleft palate (CL(P)) and isolated cleft palate (CP) in a Brazilian population. in structured interviews, case histories were taken from the mothers of a consecutive sample of 450 infants born with nonsyndromic OFC,Results: Mothers who had children with CL(P) were less likely to have been supplemented during the periconceptional period. The statistical significance of the difference in prevalence of the use of supplements between mothers of patients and of controls was greater for the CL(P) group: p < .05 for CP and p < .001 for CL(P). Multivariate analysis confirmed this finding of a protective effect for both types of orofacial cleft,Conclusions: the use of vitamin supplements in the first 4 months of pregnancy was suggestive of a protective effect against the occurrence of CP and CL(P) in this population, the significance of an association between multivitamin supplementation and OFC and the possible role of gene/environment interaction are discussed.

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This work proposes a spectrophotometric method for the determination of hydrogen peroxide during photodegradation reactions. The method is based on the reaction of H2O2 with amonium metavanadate in acidic medium, which results in the formation of a red-orange color peroxovanadium cation, with maximum absorbance at 450 nm. The method was optimized using the multivariate analysis providing the minimum concentration of vanadate (6.2 mmol L-1) for the maximum absorbance signal. Under these conditions, the detection limit is 143 mu mol L-1. The reaction product showed to be very stable for samples of peroxide concentrations up to 3 mmol L-1 at room temperature during 180 h. For higher concentrations however, samples must be kept refrigerated (4 degrees C) or diluted. The method showed no interference of Cl- (0.2-1.3 mmol L-1), NO3- (0.3-1.0 mmol L-1), Fe3+, (0.2-1.2 mmol L-1) and 2,4-dichlorophenol (DCP) (0.2-1.0 mmol L-1). When compared to iodometric titration, the vanadate method showed a good agreament. The method was applied for the evaluation of peroxide consumption during photo-Fenton degradation of 2,4-dichlorophenol using blacklight irradiation. (c) 2004 Elsevier B.V. All rights reserved.

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We evaluated the prevalence and clinical associations of amenorrhea in 298 female juvenile systemic lupus erythematosus (JSLE) patients (ACR criteria) followed in 12 Brazilian Paediatric Rheumatology centres. Amenorrhea was observed in 35 patients (11.7%) with a mean duration of 7.2 +/- 3.6 months. The hormones were performed in 32/35 patients and none of them had FSH and LH levels above and estradiol below the normal range according to pubertal changes. JSLE patients with amenorrhea were younger (15.04 +/- 2.5 versus 17.8 +/- 3.1 years; P = 0.001), and had a shorter period of time between menarche and current age (3.4 +/- 2.9 versus 6.7 +/- 5.4 years; P = 0.001). Interestingly, the frequency, cumulative dose, number of pulses and duration of intravenous cyclophosphamide treatment were alike in patients with and without amenorrhea (P > 0.05). In contrast, patients with amenorrhea had significantly higher SLEDAI (P = 0.01) and SLICC/ACR-DI (P = 0.024) scores compared to those without this condition. Independent risk factors identified by multivariate analysis were higher SLEDAI (OR=1.059; CI=1.004-1.116; P=0.034) and SLICC/ACR-DI (OR=2.125; IC = 1.373-3.291; P = 0.001) scores. Our data suggest that in spite of imummosuppressive therapy, JSLE patients have an adequate ovarian follicular reserve and amenorrhea is particularly associated with disease activity and damage.

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Background: Urothelial bladder carcinoma (UBC) is a chemo-sensitive tumour, but the response to treatment is heterogeneous. CD 147 has been associated with chemotherapy resistance. We aimed to define tumours with an aggressive phenotype by the combined analysis of clinicopathological and biological parameters.Methods: 77 patients with T1G3 or muscle-invasive UBC treated by radical cystectomy were studied. Immunohistochemistry was performed to detect CD147, heparanase, CD31 (blood vessels identification) and D2-40 (lymphatic vessels identification) expressions. The immunohistochemical reactions were correlated with the clinicopathological and the outcome parameters. 5-year disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. Multivariate analysis was performed by Cox proportional hazards analysis.Results: The 5-year DFS and OS rates were significantly influenced by the classical clinicopathological parameters, and by the occurrence of lymphovascular invasion. CD 147 and heparanase immunoexpression did not affect patients' outcome. However, patients with pT3/pT4 tumours had a median OS time of 14.7 months (95% CI 7.1-22.3, p = 0.003), which was reduced to 9.2 months (95% CI 1.5-17.0, p = 0.008) if the tumours were CD147 positive. We developed a model of tumour aggressiveness using parameters as stage, grade, lymphovascular invasion and CD147 immunoexpression, which separated a low aggressiveness from a high aggressiveness group, remaining as an independent prognostic factor of DFS (HR 3.746; 95% CI 1.244-11.285; p = 0.019) and OS (HR 3.247; 95% CI 1.015-10.388, p = 0.047).Conclusion: CD 147 overexpression, included in a model of UBC aggressiveness, may help surgeons to identify patients who could benefit from a personalized therapeutic regimen. Additional validation is needed. (C) 2011 Elsevier Ltd. All rights reserved.

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Magnetic susceptibility (chi, mass specific) is useful for easy indirect estimation of other soil properties at a low cost. The aim of this study was to assess the use of chi as measured with an analytical balance for predicting properties with a substantial influence on the management of Typic Haplustalfs in southern Brazil. To achieve this 48 topsoil samples were taken at the intersection points in a rectangular grid of 20 m x 20 m cells, with 38 of these used for calibration and 10 for validation in regression analyses. The obtained chi values were slightly higher than, and highly correlated (r = 0.970; P < 0.001) with those measured with a susceptibility meter. Highly significant (P < 0.001) correlations were also found between chi and other soil properties relevant to soil classification and management such as clay content (r = 0.68), cation exchange capacity (r = 0.62), P sorption capacity (r = 0.76) and haematite content (r = 0.82). Results from a principal component analysis of eight properties important for soil classification explained 11% of the variance in the data set. The good predictive ability of chi was consistent with current knowledge on the formation pathways for pedogenic ferrimagnets. In summary, chi, which can be readily measured with an analytical balance, has the potential for quantifying soil attributes and may therefore be used in pedotransfer functions.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Thirty-two Polwarth sheep of ages up to 1 year were observed under temperatures varying from 10.5 to 46.5°C. The following blood cell counts were made: erythrocyte (RBC), leucocyte (WBC), eosinophil (EOS), neutrophil (NEU), lymphocyte (LYM) and monocyte (MON). Other traits measured were: haemoglobin (HB), haematocrit (HT), blood glucose (GLU) and serum protein (PROT). Multivariate analysis of variance was used and the results showed a significant (P<0.001) effect for the interaction of shearing and temperature treatment. Under temperatures >25°C, sheep presented a decrease of RBC, WBC, HB and HT, these differences being greater in the shorn than in the unshorn animals. Unshorn animals presented higher variations in EOS, NEU, LYM, MON and GLU. Blood glucose increased under high temperatures in the shorn animals (from 56.36±0.65 mg/100 ml to 60.52±0.69 mg/100 ml) as in the unshorn animals (from 54.72±0.74 mg/100 ml to 57.56±0.77 mg/100 ml). © 1992 International Society of Biometeorology.

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Purpose - To analyse the influence of mannitol added to Krebs-Henseleit (KH) solution on the myocardium edema and myocardial function. Methods - Isolated rat heart under isovolumetric contractions studied according to Langendorff's technique were perfused with KH solution at constant flow during 90 min. The coronary perfusion pressure, diastolic and systolic pressures were recorded at every 15 min. At the end of the experiment, myocardium water content was measured in hearts perfused with KH solution (group I, n = 9) and in hearts perfused with KH solution plus 8 mM mannitol (group II, n = 8). These results were compared to non-perfused control heart (n = 9). Results - Myocardial water content was statistically higher in group I (80.8 ± 1.3%) compared to group II (78.1 ± 0.7%) and control group (75.5 ± 0.5%). Systolic arterial pressure was statistically higher in group I (86.2 ± 11.5 mmHg) compared to group II (72.7 ± 21.1 mmHg). There was no difference in the diastolic pressure between the two groups. Coronary perfusion pressure (Pp) increased progressively during the experiment in both groups. However, Pp was lower in group II than in group I. Conclusion - Mannitol added to KH solution significantly attenuates the myocardium edema in the isolated perfused rat heart.

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Non-allometric and clear-cut caste dimorphism were found in two colonies of the social wasp Agelaia vicina. Such type of allometry was previously recorded in the Epiponini and its origin is pre-imaginally determined as in the other analysed species which present caste dimorphism. Multivariate analyses evidenced that the most intercastes discriminant characters were found in the metasoma and mesosoma while head differences were slight. Although queens were characterized by marked ovary development and insemination, the presence of some uninseminated queens was detected in one of the analysed colonies.

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In the study of physical, chemical, and mineralogical data related to the weathering of soils and the quantification of their properties, remote sensing constitutes an important technique that, in addition to conventional analyses, can contribute to soil survey. The objectives of this research were to characterize and differentiate soils developed from basaltic rocks that occur in the Parana state, Brazil and to quantify soil properties based on their spectral reflectance. These observations were used to verify the relationship between the soils and reflectance with regard to weathering, organic matter (OM), and forms of Fe. From the least to the most weathered soil, we used a Typic Argiudoll (Reddish Brunizem), Rhodudalf (Terra Roxa Estruturada), and Rhodic Hapludox (Very Dark Red Latosol). The spectral reflectances between 400 and 2500 nm were obtained in the laboratory from soil samples collected at two depth increments, 0- to 20- and 40- to 60-cm, using an Infra Red Intelligent Spectroradiometer (IRIS). Correlation, regression, and discriminant estimates were used in analyzing the soil and spectral data. Results of this study indicated that soils could be separated at the soil-type level based on reflectance intensity in various absorption bands. Soil collected in the 40- to 60-cm depth appeared to have higher reflectance intensities than those from the 0- to 20-cm depth. Removal of OM from soil samples promoted higher reflectance intensity in the entire spectrum. Amorphous and crystalline Fe influenced reflectance differently. Weathering of basaltic soils was correlated with alterations in the reflectance intensities and absorption features of the spectral curves. Multivariate analysis demonstrated that this technique was efficient in the estimation of clay, silt, kaolinite, crystalline Fe, amorphous Fe, and Mg through the use of reflected energy of the soils.

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External morphology, internal oral anatomy, and chondrocranial anatomy were examined for tadpoles of Hyla geographica from the Amazon rainforest, Brazil, and Hyla semilineata from the Atlantic rainforest, Brazil. Here, we provide morphological larval data to help diagnose these closely related species. Scanning electron microscopy analysis of buccal morphology showed the most distinctive features between these species: the distance between the lingual papillae in the buccal floor of H. geographica is three times greater than that distance in H. semilineata, and the relative size of the lingual papillae in H. geographica is less than half their size in H. semilineata. Although the chondrocranium of both species is identical, and the external morphology of the larvae of both taxa is very similar, they differ greatly in size at most developmental stages. A multivariate analysis of covariance, corrected for stage and size, also showed a significant difference between morphometric measurements of the two species. These differences support the existence of two separate taxa.

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Objective. To assess factors determining growth in a group of children between 3 months and 6 years old enrolled in a public municipal (i.e., government-supported, not private) day-care center, in comparison to a group of children with similar characteristics but who were not enrolled in the center. Methods. A quasi-experimental study was designed to observe 444 children aged 3 to 72 months from a low-income neighborhood in the city of Sorocaba, in the state of São Paulo, Brazil. Two groups were studied: 164 children enrolled in a local municipal day-care center (intervention group) and 280 not receiving care at the center (nonintervention, comparison group) but instead being cared for at home. Both groups were seen four times over a period of 16 months. At each observation session, the children's weight and height were measured. Information was also collected on the mother's sociodemographic characteristics and the illnesses she had suffered as well as the child's weight and other health characteristics at birth, the child's illnesses in the 15 days before each observation, and any hospitalizations. Results. The children in both groups were from low-income families, with 65% of the families having an average monthly income below US$ 100; 80% of the mothers had received 8 years of schooling or less. Multivariate linear regression analysis showed that at the first observation (just before enrollment in the day-care center), birth weight was the only factor that explained the nutritional differences between the two groups. Subsequent analyses showed that being in day care was the factor that best explained the differences between the groups, especially in terms of the adequacy of weight for age, after controlling for birthweight, sex, age at the beginning of the study, and illnesses in the 15 days before an observation session. The nutritional impact of the intervention was significant as early as 3 months after being enrolled in day care. Conclusions. The nutritional benefits of the care provided at the center outweighed the negative effects sometimes seen in such centers, such as the greater morbidity that children in day-care centers often experience in comparison to children receiving care at home.

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The developmental phases of giant cells induced by root-knot nematodes (Meloidogyne exigua) in rubber plant (Hevea brasiliensis) root were studied in relation to its number and size evaluated in eight sample dates. The results were subject to cluster analysis and principal component analysis. Sample dates were clearly distinct regarding giant cell development. As a result, the nematode infestation cycle was characterized by the following sequential phases: initial, equilibrium, choice and final.