946 resultados para Repulsive and attractive correlations
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Background. Determine the presence and evolution of indicators microorganisms of water pollution in “Conde del Guadalhorce” reservoir, Málaga city, Spain. A second objective was to analyze pollution degree and evaluate the sanitary quality of bathing water and compliance with European Directive 76/160/CE. Method. A total of 120 water samples were collected in two bathing freshwater sites during May to September sampling period between 2000 to 2005, and the numbers of total coliforms (CT), faecal coliforms (CF) and faecal streptococci (EF) were enumerated using the membrane filtration method. We used the log-normal distribution method and calculate the logarithmic means, percentile points, ratios CF:EF, ANOVA and Pearson correlations. Results. Only two samples overcome CF limit values at Camping sampling station during 2000 year. Ratios CF:EF values were higher (> 4) during 2000 to 2002, and lower (< 0,7) during 2003 to 2005. Significant differences (ANOVA F = 3,41, ∝ < 0,01) was only observed with EF during evaluated period. There was no significant difference between concentration means at bathing water sites (ANOVA, F = 3,395, ∝ < 0,01). The counts of CT and CF were significantly correlated in Kiosko water samples, while in Camping water, significant correlation (t = 0,632, p < 0,05) was only observed with EF at the Camping station during 2000, 2003 and 2005 years. Conclusions. “Conde del Guadalhorce” reservoir showed hygienic conditions for safety bathing. Globally, water bathing quality is good. CT, CF y EF indicators were agreed with UE Directive during 2000- 2005, with exception CF at Camping station in 2000 year. CT y CF concentrations at Camping were frecuently higher than Kiosko, it could be caused to swimmers abundance and recreational activities. There was a trend towards rising EF, it could be caused to faecal pollution source of animal origin, needed to research it.
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In transplant rejection, graft versus host or autoimmune diseases T cells are mediating the pathophysiological processes. Compared to unspecific pharmacological immune suppression specific inhibition of those T cells, that are involved in the disease, would be an alternative and attractive approach. T cells are activated after their T cell receptor (TCR) recognizes an antigenic peptide displayed by the Major Histocompatibility Complex (MHC). Molecules that interact with MHC-peptide-complexes in a specific fashion should block T cells with identical specificity. Using the model of the SSX2 (103-111)/HLA-A*0201 complex we investigated a panel of MHC-peptide-specific Fab antibodies for their capacity blocking specific T cell clones. Like TCRs all Fab antibodies reacted with the MHC complex only when the SSX2 (103-111) peptide was displayed. By introducing single amino acid mutations in the HLA-A*0201 heavy chain we identified the K66 residue as the most critical binding similar to that of TCRs. However, some Fab antibodies did not inhibit the reactivity of a specific T cell clone against peptide pulsed, artificial targets, nor cells displaying the peptide after endogenous processing. Measurements of binding kinetics revealed that only those Fab antibodies were capable of blocking T cells that interacted with an affinity in the nanomolar range. Fab antibodies binding like TCRs with affinities on the lower micromolar range did not inhibit T cell reactivity. These results indicate that molecules that block T cells by competitive binding with the TCR must have the same specificity but higher affinity for the MHC-peptide-complex than the TCR.
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BACKGROUND: Tenofovir (TDF) use has been associated with proximal renal tubulopathy, reduced calculated glomerular filtration rates (cGFR) and losses in bone mineral density. Bone resorption could result in a compensatory osteoblast activation indicated by an increase in serum alkaline phosphatase (sAP). A few small studies have reported a positive correlation between renal phosphate losses, increased bone turnover and sAP. METHODS: We analysed sAP dynamics in patients initiating (n = 657), reinitiating (n = 361) and discontinuing (n = 73) combined antiretroviral therapy with and without TDF and assessed correlations with clinical and epidemiological parameters. RESULTS: TDF use was associated with a significant increase of sAP from a median of 74 U/I (interquartile range 60-98) to a plateau of 99 U/I (82-123) after 6 months (P < 0.0001), with a prompt return to baseline upon TDF discontinuation. No change occurred in TDF-sparing regimes. Univariable and multivariable linear regression analyses revealed a positive correlation between sAP and TDF use (P < or = 0.003), but no correlation with baseline cGFR, TDF-related cGFR reduction, changes in serum alanine aminotransferase (sALT) or active hepatitis C. CONCLUSIONS: We document a highly significant association between TDF use and increased sAP in a large observational cohort. The lack of correlation between TDF use and sALT suggests that the increase in sAP is because of the bone isoenzyme and indicates stimulated bone turnover. This finding, together with published data on TDF-related renal phosphate losses, this finding raises concerns that TDF use could result in osteomalacia with a loss in bone mineral density at least in a subset of patients. This potentially severe long-term toxicity should be addressed in future studies.
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We present strategies for chemical shift assignments of large proteins by magic-angle spinning solid-state NMR, using the 21-kDa disulfide-bond-forming enzyme DsbA as prototype. Previous studies have demonstrated that complete de novo assignments are possible for proteins up to approximately 17 kDa, and partial assignments have been performed for several larger proteins. Here we show that combinations of isotopic labeling strategies, high field correlation spectroscopy, and three-dimensional (3D) and four-dimensional (4D) backbone correlation experiments yield highly confident assignments for more than 90% of backbone resonances in DsbA. Samples were prepared as nanocrystalline precipitates by a dialysis procedure, resulting in heterogeneous linewidths below 0.2 ppm. Thus, high magnetic fields, selective decoupling pulse sequences, and sparse isotopic labeling all improved spectral resolution. Assignments by amino acid type were facilitated by particular combinations of pulse sequences and isotopic labeling; for example, transferred echo double resonance experiments enhanced sensitivity for Pro and Gly residues; [2-(13)C]glycerol labeling clarified Val, Ile, and Leu assignments; in-phase anti-phase correlation spectra enabled interpretation of otherwise crowded Glx/Asx side-chain regions; and 3D NCACX experiments on [2-(13)C]glycerol samples provided unique sets of aromatic (Phe, Tyr, and Trp) correlations. Together with high-sensitivity CANCOCA 4D experiments and CANCOCX 3D experiments, unambiguous backbone walks could be performed throughout the majority of the sequence. At 189 residues, DsbA represents the largest monomeric unit for which essentially complete solid-state NMR assignments have so far been achieved. These results will facilitate studies of nanocrystalline DsbA structure and dynamics and will enable analysis of its 41-kDa covalent complex with the membrane protein DsbB, for which we demonstrate a high-resolution two-dimensional (13)C-(13)C spectrum.
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This paper illustrates the philosophy which forms the basis of calibrationexercises in general equilibrium macroeconomic models and the details of theprocedure, the advantages and the disadvantages of the approach, with particularreference to the issue of testing ``false'' economic models. We provide anoverview of the most recent simulation--based approaches to the testing problemand compare them to standard econometric methods used to test the fit of non--lineardynamic general equilibrium models. We illustrate how simulation--based techniques can be used to formally evaluate the fit of a calibrated modelto the data and obtain ideas on how to improve the model design using a standardproblem in the international real business cycle literature, i.e. whether amodel with complete financial markets and no restrictions to capital mobility is able to reproduce the second order properties of aggregate savingand aggregate investment in an open economy.
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Introduction: Low cardiac output syndrome is frequent in childrenafter heart surgery for congenital heart disease and may result in pooroutcome and increased morbidity. In the adult population, preoperativebrain natriuretic peptide (BNP) was shown to be predictive of postoperative complications. In children, the value of preoperative BNP onpostoperative outcome is not so clear. The aim of this study was todetermine the predictive value of preoperative BNP on postoperativeoutcome and low cardiac output syndrome in children after heartsurgery for congenital heart disease.Methods: We examined, retrospectively, the postoperative course of97 pediatric patients (mean age 3.7 years, range 0-14 years old) whounderwent heart surgery in a tertiary care pediatric intensive caresetting. NTproBNP was measured preoperatively in all patients(median 412 pg/ml, range 12-35'000 pg/ml). Patients were divided intothree groups according to their NTproBNP levels (group 1: 0-300 pg/ml, group 2: 300-600 pg/ml, group 3: >600 pg/ml) and then,correlations with postoperative outcomes were examined.Results: We found that patients with a high preoperative BNP requiredmore frequently prolonged (>2 days) mechanical ventilation (33%vs 40% vs 61%, p = 0.045) and stayed more frequently longer than6 days in the intensive care unit (42% vs 50% vs 71%, p = 0.03).However, high preoperative BNP was not correlated with occurrenceof low cardiac output syndrome.Conclusion: Preoperative BNP cannot be used, in children, as areliable and sole predictor of postoperative low cardiac outputsyndrome. However it may help identify, before surgery, those patientsat risk of having a difficult postoperative course.
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OBJECTIVE: The aim of this study was to evaluate a French language version of the Adolescent Drug Abuse Diagnosis (ADAD) instrument in a Swiss sample of adolescent illicit drug and/or alcohol users. PARTICIPANTS AND SETTING: The participants in the study were 102 French-speaking adolescents aged 13-19 years who fitted the criteria of illicit drug or alcohol use (at least one substance--except tobacco--once a week during the last 3 months). They were recruited in hospitals, institutions and leisure places. Procedure. The ADAD was administered individually by trained psychologists. It was integrated into a broader protocol including alcohol and drug abuse DSM-IV diagnoses, the BDI-13 (Beck Depression Inventory), life events and treatment trajectories. RESULTS: The ADAD appears to show good inter-rater reliability; the subscales showed good internal coherence and the correlations between the composite scores and the severity ratings were moderate to high. Finally, the results confirmed good concurrent validity for three out of eight ADAD dimensions. CONCLUSIONS: The French language version of the ADAD appears to be an adequate instrument for assessing drug use and associated problems in adolescents. Despite its complexity, the instrument has acceptable validity, reliability and usefulness criteria, enabling international and transcultural comparisons.
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BACKGROUND: Several studies have established Glioblastoma Multiforme (GBM) prognostic and predictive models based on age and Karnofsky Performance Status (KPS), while very few studies evaluated the prognostic and predictive significance of preoperative MR-imaging. However, to date, there is no simple preoperative GBM classification that also correlates with a highly prognostic genomic signature. Thus, we present for the first time a biologically relevant, and clinically applicable tumor Volume, patient Age, and KPS (VAK) GBM classification that can easily and non-invasively be determined upon patient admission. METHODS: We quantitatively analyzed the volumes of 78 GBM patient MRIs present in The Cancer Imaging Archive (TCIA) corresponding to patients in The Cancer Genome Atlas (TCGA) with VAK annotation. The variables were then combined using a simple 3-point scoring system to form the VAK classification. A validation set (N = 64) from both the TCGA and Rembrandt databases was used to confirm the classification. Transcription factor and genomic correlations were performed using the gene pattern suite and Ingenuity Pathway Analysis. RESULTS: VAK-A and VAK-B classes showed significant median survival differences in discovery (P = 0.007) and validation sets (P = 0.008). VAK-A is significantly associated with P53 activation, while VAK-B shows significant P53 inhibition. Furthermore, a molecular gene signature comprised of a total of 25 genes and microRNAs was significantly associated with the classes and predicted survival in an independent validation set (P = 0.001). A favorable MGMT promoter methylation status resulted in a 10.5 months additional survival benefit for VAK-A compared to VAK-B patients. CONCLUSIONS: The non-invasively determined VAK classification with its implication of VAK-specific molecular regulatory networks, can serve as a very robust initial prognostic tool, clinical trial selection criteria, and important step toward the refinement of genomics-based personalized therapy for GBM patients.
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Metastatic melanoma has a poor prognosis with high resistance to chemotherapy and radiation. Recently, the anti-CTLA-4 antibody ipilimumab has demonstrated clinical efficacy, being the first agent to significantly prolong the overall survival of inoperable stage III/IV melanoma patients. A major aim of patient immune monitoring is the identification of biomarkers that predict clinical outcome. We studied circulating myeloid-derived suppressor cells (MDSC) in ipilimumab-treated patients to detect alterations in the myeloid cell compartment and possible correlations with clinical outcome. Lin(-) CD14(+) HLA-DR(-) monocytic MDSC were enriched in peripheral blood of melanoma patients compared to healthy donors (HD). Tumor resection did not significantly alter MDSC frequencies. During ipilimumab treatment, MDSC frequencies did not change significantly compared to baseline levels. We observed high inter-patient differences. MDSC frequencies in ipilimumab-treated patients were independent of baseline serum lactate dehydrogenase levels but tended to increase in patients with severe metastatic disease (M1c) compared to patients with metastases in skin or lymph nodes only (M1a), who had frequencies comparable to HD. Interestingly, clinical responders to ipilimumab therapy showed significantly less lin(-) CD14(+) HLA-DR(-) cells as compared to non-responders. The data suggest that the frequency of monocytic MDSC may be used as predictive marker of response, as low frequencies identify patients more likely benefitting from ipilimumab treatment. Prospective clinical trials assessing MDSC frequencies as potential biomarkers are warranted to validate these observations.
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We study the effects of time and space correlations of an external additive colored noise on the steady-state behavior of a time-dependent Ginzburg-Landau model. Simulations show the existence of nonequilibrium phase transitions controlled by both the correlation time and length of the noise. A Fokker-Planck equation and the steady probability density of the process are obtained by means of a theoretical approximation.
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It is well-known nowadays that soil variability can influence crop yields. Therefore, to determine specific areas of soil management, we studied the Pearson and spatial correlations of rice grain yield with organic matter content and pH of an Oxisol (Typic Acrustox) under no- tillage, in the 2009/10 growing season, in Selvíria, State of Mato Grosso do Sul, in the Brazilian Cerrado (longitude 51º24' 21'' W, latitude 20º20' 56'' S). The upland rice cultivar IAC 202 was used as test plant. A geostatistical grid was installed for soil and plant data collection, with 120 sampling points in an area of 3.0 ha with a homogeneous slope of 0.055 m m-1. The properties rice grain yield and organic matter content, pH and potential acidity and aluminum content were analyzed in the 0-0.10 and 0.10-0.20 m soil layers. Spatially, two specific areas of agricultural land management were discriminated, differing in the value of organic matter and rice grain yield, respectively with fertilization at variable rates in the second zone, a substantial increase in agricultural productivity can be obtained. The organic matter content was confirmed as a good indicator of soil quality, when spatially correlated with rice grain yield.
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Currently, sugarcane plays an important global role, particularly with a view to alternative energy sources. Thus, in a sugarcane field of the mill Vale do Paraná S/A Álcool e Açúcar, Rubineia, São Paulo State, managed under two green cane harvest systems (cane trash left on and cane trash removed from the soil), Pearson and spatial correlations between the sugarcane yield (variety RB855035 in the third cut) and soil physical and chemical properties were studied to identify the property best correlated with stalk yield and the best harvest method. For this purpose, two geostatistical grids (121 sampling points on 1.30 ha) were installed on a eutrophic Red Argisol (homogeneous slope of 0.065 m m-1), in 2011, to determine the properties: stalk yield and sugarcane plant population, and soil resistance to penetration, gravimetric moisture, bulk density, and carbon stock, in the layers 0-0.20 and 0.20-0.40 m. The data were analyzed by descriptive, linear correlation and geostatistical analysis. In both treatments, the property stand density was best correlated with sugarcane yield (r = 0.725 in the trash mulching treatment - TM and r = 0.769 in the trash removal treatment - TR). However, in relation to the soil properties, bulk density (0-0.20 m) was best correlated (r = 0.305 in TM, r = 0.211 in TR). Similarly, from the spatial point of view, stand density was the property that best explained the sugarcane yield. However, in the TM treatment the density (0.20-0.40 m) was the only soil property spatially correlated with stalk yield. The carbon stock in the soil of the TM was 11.5 % higher than in the TR treatment. Results of the TM treatment were best, also with regard to soil management and conservation.
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BACKGROUND Few population studies have described the heritability and intrafamilial concordance of the retinal microvessels, or the genetic or environmental correlations of the phenotypes of these vessels. METHODS We randomly selected 413 participants from 70 families (mean age, 51.5 years; 50.1% women) from a Flemish population. We postprocessed retinal images using IVAN software to generate the central retinal arteriole equivalent (CRAE), central retinal venule equivalent (CRVE), and arteriole-to-venule-ratio (AVR) from these images. We used SAGE version 6.2 and SAS version 9.2 to compute multivariate-adjusted estimates of heritability and intrafamilial correlations of the CRAE, CRVE, and AVR of the retinal microvessels in the images. RESULTS Sex, age, mean arterial pressure, and smoking explained up to 12.7% of the variance of the phenotypes of the retinal microvessels of the study participants. With adjustments applied for these covariates, the heritability estimates of CRAE, CRVE, and AVR were 0.213 (P = 0.044), 0.339 (P = 0.010), and 0.272 (P = 0.004), respectively. The parent-offspring correlations for CRAE, CRVE, and AVR were 0.118 (NS), 0.225 (P < 0.01), and 0.215 (P < 0.05), respectively. The corresponding values were 0.222 (P < 0.05), 0.213 (P < 0.05), and 0.390 (P < 0.001) for sib-sib correlations, respectively. The genetic and environmental correlations between CRAE and CRVE were 0.360 and 0.545 (P < 0.001 for both). CONCLUSION Our study showed moderate heritability for CRAE, CRVE, and AVR, and a significant genetic correlation of CRAE with CRVE in the Flemish population of our study. These findings suggest that genetic factors influence the diameter of the retinal microvessels, and that CRAE and CRVE share some genetic determinants.
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We report the characterisation of 27 cardiovascular-related traits in 23 inbred mouse strains. Mice were phenotyped either in response to chronic administration of a single dose of the beta-adrenergic receptor blocker atenolol or under a low and a high dose of the beta-agonist isoproterenol and compared to baseline condition. The robustness of our data is supported by high trait heritabilities (typically H(2)>0.7) and significant correlations of trait values measured in baseline condition with independent multistrain datasets of the Mouse Phenome Database. We then focused on the drug-, dose-, and strain-specific responses to beta-stimulation and beta-blockade of a selection of traits including heart rate, systolic blood pressure, cardiac weight indices, ECG parameters and body weight. Because of the wealth of data accumulated, we applied integrative analyses such as comprehensive bi-clustering to investigate the structure of the response across the different phenotypes, strains and experimental conditions. Information extracted from these analyses is discussed in terms of novelty and biological implications. For example, we observe that traits related to ventricular weight in most strains respond only to the high dose of isoproterenol, while heart rate and atrial weight are already affected by the low dose. Finally, we observe little concordance between strain similarity based on the phenotypes and genotypic relatedness computed from genomic SNP profiles. This indicates that cardiovascular phenotypes are unlikely to segregate according to global phylogeny, but rather be governed by smaller, local differences in the genetic architecture of the various strains.