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Stronger Correlation (stronger + correlation)
Selected AbstractsImpacts of nonpoint inputs from potato farming on populations of slimy sculpin (Cottus cognatus)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2005Michelle A. Gray Abstract The potential influence of agricultural activity, particularly potato cultivation, on slimy sculpin populations (Cottus cognatus) was examined at 19 rivers of New Brunswick, Canada. Comparisons with forested streams resulted in differences in fish density, size, and reproductive performance. Young-of-the-year (YOY) sculpin were present only at two of 11 agricultural sites, though they were present at all nine forested sites. Sediment deposition was greatest at agricultural sites, with increased fine sediments deposited. Larger, coarse sands were deposited at two sites with active forest operations. Temperature had a stronger correlation than sedimentation with sculpin size and density in the agricultural region. Agricultural catchments were warmer than in forested catchments (median = 16.0 and 13.3°C, respectively). Body size of slimy sculpin was correlated positively and YOY densities correlated negatively with temperature, and sites with temperatures ,25°C were devoid of YOY sculpin. Our data indicate there is a significant effect of temperature on slimy sculpin populations in rivers of potato farming areas, highlighting the importance of examining indirect factors when investigating possible impacts of nonpoint source agricultural inputs. Indirect factors such as sediment deposition and temperature need to be considered in order to discriminate accurately the chronic impacts of agricultural chemicals on fish populations. [source] Tissue inhibitor of metalloproteinse-1 is a marker of diastolic dysfunction using tissue doppler in patients with type 2 diabetes and hypertensionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2005M. H. Tayebjee Abstract Background, Tissue inhibitor of metalloproteinase-1 (TIMP-1) is associated with increased fibrosis of the extracellular matrix (ECM). Myocardial stiffness is a feature of diastolic dysfunction. We assessed circulating TIMP-1 as a marker of diastolic dysfunction in patients with type 2 diabetes mellitus (DM) and hypertension, who were compared with healthy controls. Methods, We recruited 54 patients (43 males; mean age 68 ± 5 years) with treated type 2 DM (i.e. controlled glycaemia, hypertension, hyperlipidaemia), 35 (30 males; 69 ± 8 years) treated nondiabetic hypertensives, and 31 healthy controls (18 males; 66 ± 5 years). Circulating TIMP-1 was measured by ELISA. Using transthoracic echocardiography, the early (E) diastolic mitral inflow velocity was measured with pulse wave Doppler, and the early mitral annular velocity (e,), a recognized index of diastolic relaxation, was measured with tissue Doppler. The E/A ratio was also calculated and isovolumic relaxation time measured. Results, Mean e, levels differed significantly between controls, diabetics and hypertensives (P < 0·0001). Circulating TIMP-1 was significantly different between patients and controls (P = 0·006), but there was no statistically significant difference between the DM and hypertension group. In both groups, only e, was negatively correlated with TIMP-1 levels, with a stronger correlation among the hypertensive patients (Spearman r = ,0·544, P = 0·001) when compared with the diabetic group (r = ,0·341, P = 0·011). Conclusion, Diastolic relaxation is impaired in diabetes and hypertensive patients. The relationship between TIMP-1 and e, may reflect increased myocardial fibrosis and consequent diastolic dysfunction, which may be more prominent in hypertension. [source] Italian validation of INQoL, a quality of life questionnaire for adults with muscle diseasesEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2010V. A. Sansone Background and purpose:, A quality of life (QoL) questionnaire for neuromuscular diseases was recently constructed and validated in the United Kingdom in a sample of adult patients with a variety of muscle disorders. Preliminary results suggested it could be a more relevant and practical measure of QoL in muscle diseases than generic health measures of QoL. The purpose of our work was: (i) To validate INQoL in Italy on a larger sample of adult patients with muscle diseases (ii) to compare INQoL to SF-36. Methods:, We have translated into Italian and applied language adaptations to the original UK INQoL version. We studied 1092 patients with different muscle disorders and performed (i) test,retest reliability (n = 80); (ii) psychometric (n = 345), known-group (n = 1092), external criterion (n = 70), and concurrent validity with SF-36 (n = 183). Results:, We have translated and formally validated the Italian version of INQoL confirming and extending results obtained in the United Kingdom. In addition to good results in terms of reliability, known-group and criterion validity, a comparison with the SF-36 scales showed a stronger association between INQoL total index and SF-36 physical (r = ,0.72) than mental (r = ,0.38) summary health indexes. When considering comparable domains of INQoL and SF-36 with respect to an objective measure of muscle strength assessment (MMRC), regression analysis showed a stronger correlation using INQoL rather than SF-36 scores. Conclusions:, INQoL is recommended to assess QoL in muscle diseases because of its ability to capture physical limitations that are specifically relevant to the muscle condition. [source] Relationship Between Heart Rate Turbulence and Heart Rate, Heart Rate Variability, and Number of Ventricular Premature Beats in Coronary PatientsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2004IWONA CYGANKIEWICZ M.D., Ph.D. Introduction: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. Methods and Results: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. ,0.16 to ,0.38 for TO). Conclusion: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate. (J Cardiovasc Electrophysiol, Vol. 15, pp. 731-737, July 2004) [source] Magnetic resonance images of the globus pallidus in patients with idiopathic portal hypertension: A quantitative analysis of the relationship between signal intensity and the grade of portosystemic shuntJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2006Takeshi Fukuzawa Abstract Background and Aim:, To elucidate a quantitative relationship between hyperintensity of the globus pallidus on T1-weighted magnetic resonance images (MRI) and portosystemic shunt (PSS) in portal hypertension. Methods:, Fifteen patients with idiopathic portal hypertension (IPH) and 44 patients with liver cirrhosis (LC) underwent brain MRI to asses signal intensity at the globus pallidus and Doppler sonography to examine the blood flow volume of PSS. Blood manganese (Mn) levels were examined in 36 patients and neuropsychological tests were performed in 15 patients without overt hepatic encephalopathy. Results:, Pallidal hyperintensity on MRI was more prominent in patients with IPH than in patients with LC. There was no correlation between MRI pallidal hyperintensity and the severity of liver dysfunction or hepatic encephalopathy. The grade of hyperintensity correlated well with the grade of PSS. The correlation was stronger in patients with IPH than in patients with LC. The plasma ammonia level and whole blood Mn level significantly correlated with MRI pallidal hyperintensity, but blood Mn level showed a stronger correlation than plasma ammonia. Conclusion:, Hyperintensity of the globus pallidus on T1-weighted MRI correlated with the development of PSS independent of liver cell function. This brain image should be an index of the grade of PSS rather than a landmark of chronic liver failure. [source] Retrospective review of children presenting with non cystic fibrosis bronchiectasis: HRCT features and clinical relationships,PEDIATRIC PULMONOLOGY, Issue 2 2003E.A. Edwards FRACP Abstract Non cystic fibrosis (CF) bronchiectasis in children presents with a spectrum of disease severity. Our aims were to document the extent and severity of disease in children with non-CF bronchiectasis, to review the inter- and intraobserver agreement for the high-resolution computed tomography (HRCT) features examined, and to assess correlations between HRCT features and clinical measures of severity. We performed a retrospective review of 56 children from the Starship Children's Hospital. HRCT scans were scored by a modified Bhalla system, and the chest X-rays using the Brasfield score. Scores were correlated with demographics, number of hospitalizations, disease duration, pulmonary function, clinical examination, and chronic sputum infection. The bronchiectasis seen was widespread and severe, particularly in Maori and Pacific Island children. The kappa coefficient for intraobserver agreement was better than that for interobserver agreement. Comparisons between HRCT scan and lung function parameters showed that the strongest relationships were between forced expiratory volume in 1 sec (FEV1) and forced expiratory flow between 25,75% of forced vital capacity (FEF25,75) with the extent of bronchiectasis, bronchial wall thickening, and air trapping. Children with digital clubbing and chest deformity showed significantly higher scores for extent of bronchiectasis, bronchial wall dilatation and thickness, and overall computed tomography (CT) score. No relationship was demonstrated between chronic sputum infection and CT score. The HRCT score demonstrated a stronger correlation between the extent and severity of bronchiectasis, and spirometry values, than the chest X-ray score. In conclusion, pediatric non-CF bronchiectasis in Auckland is extensive and severe. The good intraobserver ratings mean that consistency of scoring is possible on repeated scans. This study cannot comment on the relationships of CT and less severe disease. Pediatr Pulmonol. 2003; 36:87,93. © 2003 Wiley-Liss, Inc. [source] Preoperative Differences Between Male and Female Patients With Sleep Apnea,THE LARYNGOSCOPE, Issue 9 2001Regina Paloyan Walker MD Abstract Objectives/Hypothesis To evaluate the differences between female and male patients with obstructive sleep apnea syndrome (OSAS) in the preoperative period. Study Design Nonrandomized cross-sectional study. Methods An analysis of 686 patients (111 women and 575 men) with OSAS was completed. Multivariate modeling techniques were employed to correlate gender with the preoperative respiratory disturbance index (RDI), apnea index (AI), hypopnea index (HI), body mass index (BMI), age, and initial symptoms. Results At presentation, the male patients were significantly younger and had a lower BMI and a higher RDI and AI than the female patients. For the entire OSAS population studied, the RDI increased as the BMI increased (correlation coefficient [r] = 0.35, P = <.001). For the female patients there was a weaker correlation (r = 0.21, P = .034), and in male patients there was a stronger correlation (r = 0.40, P <.001). For the entire population there was a negative correlation between age and RDI (r = ,0.15, P <.001). In female patients there was a nonsignificant correlation (r = ,0.09, P = .35), and in male patients the correlation was significant (r = ,0.16, P <.001). There was no difference in the reporting of the number of symptoms based on gender (P = .355). Female patients noted headaches on awakening more commonly than male patients (P = .001), and male patients noted snoring (P = .014) and stopping breathing during sleep (P = .001) more often than female patients. Conclusions The analysis demonstrated that within a surgical population sample, gender differences exist. The findings of this series were as follows: 1) Apnea severity in women was less weight-dependent than in men; (2) in men there was a significant negative correlation between age and apnea severity; and (3) female and male patients reported the same number of signs or symptoms on presentation, although certain signs and symptoms were more commonly reported based on gender. Current clinical evaluation practices must take into account this gender disparity. [source] Antibodies against citrullinated vimentin in rheumatoid arthritis: Higher sensitivity and extended prognostic value concerning future radiographic progression as compared with antibodies against cyclic citrullinated peptides,ARTHRITIS & RHEUMATISM, Issue 1 2008Linda Mathsson Objective The Sa autoantigen can be found in inflamed synovium of patients with rheumatoid arthritis (RA), and at least part of the humoral RA-specific anti-Sa response is directed against citrullinated vimentin. This study was undertaken to evaluate the sensitivity, specificity, and prognostic value of determination of levels of antibodies against modified citrullinated vimentin (anti-MCV) as compared with antibodies against cyclic citrullinated peptides (anti-CCP) in an inception cohort of patients with early RA. Methods Clinical data, radiographs, and measurements of levels of anti-MCV and anti-CCP antibodies were obtained in 273 patients with early RA at baseline, after 3 months, and after 1, 2, 3, and 5 years. Autoantibodies were also analyzed in 100 healthy controls. Results Of the 273 patients, 193 (70.7%) were anti-MCV positive and 158 (57.9%) were anti-CCP positive at the time of diagnosis, with nearly equal specificities (95% and 96%, respectively). Forty (14.7%) were anti-MCV positive only, and 5 (1.8%) were anti-CCP positive only. Anti-MCV,positive and anti-MCV,negative patients had similar disease activity at baseline, but presence of anti-MCV was predictive of subsequent high disease activity and continued radiographic progression. Changes in anti-MCV level showed stronger correlation with changes in clinical parameters than did changes in anti-CCP level. The subgroup of patients who were anti-MCV positive and anti-CCP negative showed a higher rate of radiographic destruction than did patients who were negative for both anti-MCV and anti-CCP. Conclusion These findings show that when patients with early RA are compared with healthy controls, analysis of anti-MCV yields greater sensitivity and unchanged specificity as compared with analysis of anti-CCP. Anti-MCV also appears to perform better than anti-CCP in identifying poor radiographic prognosis in patients with early RA. [source] APPROXIMATING VOLATILITIES BY ASYMMETRIC POWER GARCH FUNCTIONSAUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 2 2009Jeremy Penzer Summary ARCH/GARCH representations of financial series usually attempt to model the serial correlation structure of squared returns. Although it is undoubtedly true that squared returns are correlated, there is increasing empirical evidence of stronger correlation in the absolute returns than in squared returns. Rather than assuming an explicit form for volatility, we adopt an approximation approach; we approximate the ,th power of volatility by an asymmetric GARCH function with the power index , chosen so that the approximation is optimum. Asymptotic normality is established for both the quasi-maximum likelihood estimator (qMLE) and the least absolute deviations estimator (LADE) in our approximation setting. A consequence of our approach is a relaxation of the usual stationarity condition for GARCH models. In an application to real financial datasets, the estimated values for , are found to be close to one, consistent with the stylized fact that the strongest autocorrelation is found in the absolute returns. A simulation study illustrates that the qMLE is inefficient for models with heavy-tailed errors, whereas the LADE is more robust. [source] Reliability of a telephone-administered cognitive test battery (TACT) between telephone and face-to-face administrationINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2001Neil R. Thompson Abstract We have previously described the development and initial validation of a telephone administered cognitive test battery (TACT). This report investigates the retest reliability of the TACT battery between telephone administration and face-to-face administration and measures the concurrent validity of the test components against a standard test of cognitive ability, the WAIS-RUK. Data were collected on 27 participants aged 62,63 years. There was a two- to 10-month interval between time 1 (telephone) and time 2 (face-to-face) administration. Intra-class correlation coefficients for telephone versus face-to-face administration of the TACT were satisfactory for all component measures except for ,object rotation' and WAIS similarities. There was no evidence of systematic cheating on the telephone-administered test. Tests of concurrent validity showed stronger correlations for the TACT battery components with verbal tests rather than performance tests, as measured by the WAIS-RUK. A few administration difficulties are noted and recommendations for change are outlined. The TACT is a convenient assessment tool with potential for measuring cognitive change in epidemiological studies. Copyright © 2001 Whurr Publishers Ltd. [source] The Preliminary Employment Interview as a Predictor of Assessment Center OutcomesINTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 2 2008Kobi Dayan The current study examined the relationships between personnel employment interview scores (PEI), cognitive ability test scores (CAT) and assessment center (AC) scores, as well as the potential to circumvent the costly AC method for some of the candidates by using these less expensive selection methods. A total of 423 Israeli police force candidates participated in the study. Their PEI and CAT scores were collected in the first stage of the selection process. They subsequently participated in an AC and a final decision was made regarding their acceptance to the police force. It was found that PEI and CAT scores significantly correlated with the AC scores and the recruitment decision, although the PEI scores demonstrated stronger correlations with the criteria. An actuarial analysis demonstrated the benefit of using the AC procedure for those achieving middle range scores on the PEI and CAT, circumventing the costly ACs for those achieving high and low scores. This strategy resulted in minor costs of both , and , errors. Organizations can adopt this economical strategy when the AC costs exceed the manpower costs incurred by disposing of the AC. [source] An evaluation of the psychometric properties of the traumatic events questionnaire in primary care patientsJOURNAL OF TRAUMATIC STRESS, Issue 1 2008Eric F. Crawford This study examined the reliability of reports of traumatic experiences across the Traumatic Events Questionnaire (TEQ; S. Vrana & D. Lauterbach, 1994) and the Composite International Diagnostic Interview (CIDI; World Health Organization, 1998), and evaluated other psychometric properties of the TEQ in 154 primary care patients. Agreement rates for various traumatic experiences were moderate to substantial, with sexual abuse showing 87% agreement, and other forms of trauma exhibiting rates from 81,74%. The TEQ yields a trauma intensity score, which produced stronger correlations with self-reported PTSD symptoms and problematic anger than the sum of traumas experienced. Trauma intensity also proved to be a powerful predictor of posttraumatic stress disorder (PTSD) diagnostic status. Results support the TEQ as a measure of traumatic exposure in primary care populations. [source] A robust method for determining 1H,15N long-range correlations: 15N optimized CIGAR-HMBC experiments,MAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2003Mike Kline Abstract An examination of a variety of common nitrogen-containing systems was undertaken to optimize parameters for observation of 1H,15N long-range correlations. Because of the diversity of coupling constants encountered with 1H,15N correlations, a modified accordion-based sequence was used to provide the best results. Optimization of the values for the accordion delay revealed that a range between 3 and 10 Hz provided the best compromise between detection of weak correlations and loss of signal to T2 processes. Multiple bond correlations were readily detected for each class of compound with the exception of anilines. Correlations within heterocyclic systems revealed some general patterns. In general, stronger correlations were observed from protons to ,pyrrole-like' nitrogens than to the ,pyridine-type' nitrogens of imidazoles and pyrazoles. Very long-range (four- and five-bond) correlations were routinely observed between methyl groups and the nitrogens of aromatic heterocycles. Copyright © 2003 John Wiley & Sons, Ltd. [source] Scoring Total Inflammation Is Superior to the Current Banff Inflammation Score in Predicting Outcome and the Degree of Molecular Disturbance in Renal AllograftsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009M. Mengel Emerging molecular analysis can be used as an objective and independent assessment of histopathological scoring systems. We compared the existing Banff i-score to the total inflammation (total i-) score for assessing the molecular phenotype in 129 renal allograft biopsies for cause. The total i-score showed stronger correlations with microarray-based gene sets representing major biological processes during allograft rejection. Receiver operating characteristic curves showed that total-i was superior (areas under the curves 0.85 vs. 0.73 for Banff i-score, p = 0.012) at assessing an abnormal cytotoxic T-cell burden, because it identified molecular disturbances in biopsies with advanced scarring. The total-i score was also a better predictor of graft survival than the Banff i-score and essentially all current diagnostic Banff categories. The exception was antibody-mediated rejection which is able to predict graft loss with greater specificity (96%) but at low sensitivity (38%) due to the fact that it only applies to cases with this diagnosis. The total i-score is able to achieve moderate sensitivities (60,80%) with losses in specificity (60,80%) across the whole population. Thus, the total i-score is superior to the current Banff i-score and most diagnostic Banff categories in predicting outcome and assessing the molecular phenotype of renal allografts. [source] Variation in ecophysiology and carbon economy of invasive and native woody vines of riparian zones in south-eastern QueenslandAUSTRAL ECOLOGY, Issue 6 2010OLUSEGUN O. OSUNKOYA Abstract Exotic and invasive woody vines are major environmental weeds of riparian areas, rainforest communities and remnant natural vegetation in coastal eastern Australia, where they smother standing vegetation, including large trees, and cause canopy collapse. We investigated, through glasshouse resource manipulative experiments, the ecophysiological traits that might facilitate faster growth, better resource acquisition and/or utilization and thus dominance of four exotic and invasive vines of South East Queensland, Australia, compared with their native counterparts. Relative growth rate was not significantly different between the two groups but water use efficiency (WUE) was higher in the native species while the converse was observed for light use efficiency (quantum efficiency, AQE) and maximum photosynthesis on a mass basis (). The invasive species, as a group, also exhibited higher respiration load, higher light compensation point and higher specific leaf area. There were stronger correlations of leaf traits and greater structural (but not physiological) plasticity in invasive species than in their native counterparts. The scaling coefficients of resource use efficiencies (WUE, AQE and respiration efficiency) as well as those of fitness (biomass accumulated) versus many of the performance traits examined did not differ between the two species-origin groups, but there were indications of significant shifts in elevation (intercept values) and shifts along common slopes in many of these relationships , signalling differences in carbon economy (revenue returned per unit energy invested) and/or resource usage. Using ordination and based on 14 ecophysiological attributes, a fair level of separation between the two groups was achieved (51.5% explanatory power), with AQE, light compensation point, respiration load, WUE, specific leaf area and leaf area ratio, in decreasing order, being the main drivers. This study suggests similarity in trait plasticity, especially for physiological traits, but there appear to be fundamental differences in carbon economy and resource conservation between native and invasive vine species. [source] Differential correlates to self-report and parent-report of callous,unemotional traits in a sample of juvenile sexual offendersBEHAVIORAL SCIENCES & THE LAW, Issue 6 2009Stuart F. White M.A. The association of callous,unemotional (CU) traits with violence and severe antisocial behavior has led to a recent focus on the association between CU traits and sexual offending behavior. When assessing juveniles with sexual offenses, practice standards recommend that multiple sources of data are considered. However, the differential correlates of parent-report versus self-report of CU traits in juvenile sex offenders have not been investigated. A sample of 94 detained male youth (mean age,=,15.22, SD,=,1.48) was administered both youth and parent versions of the Inventory of Callous,Unemotional Traits (ICU), a general delinquency risk assessment tool (YLS), and a sexual offending risk assessment tool (J-SOAP-II) to investigate concordance between self-report and parent-report of CU traits as well as association with general and sex-specific risk factors. Both parent-report and self-report of CU traits were significantly related to higher general delinquency risk scores, with parent-report showing stronger correlations than self-report. Both parent-report and self-report were related to sex-specific risk factors. However, only parent-report significantly predicted static sexual risk, while self-report significantly predicted dynamic sexual risk scores. Evidence supports the importance of including both parent- and self-report of CU traits in the comprehensive assessment of sexually offending youth. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||||||||