Initial Ship Design Using a Pearson Correlation Coefficient and Artificial Intelligence Techniques

NASA Astrophysics Data System (ADS)

Moon, Byung Young; Kim, Soo Young; Kang, Gyung Ju

In this paper we analyzed correlation between geometrical character and resistance, and effective horse power by using Pearson correlation coefficient which is one of the data mining methods. Also we made input data to ship's geometrical character which has strong correlation with output data. We calculated effective horse power and resistance by using Neuro-Fuzzy system. To verify the calculation, 9 of 11 container ships' data were improved as data of Neuro-Fuzzy system and the others were improved as verification data. After analyzing rate of error between existing data and calculation data, we concluded that calculation data have sound agreement with existing data.

Ghost imaging based on Pearson correlation coefficients

NASA Astrophysics Data System (ADS)

Yu, Wen-Kai; Yao, Xu-Ri; Liu, Xue-Feng; Li, Long-Zhen; Zhai, Guang-Jie

2015-05-01

Correspondence imaging is a new modality of ghost imaging, which can retrieve a positive/negative image by simple conditional averaging of the reference frames that correspond to relatively large/small values of the total intensity measured at the bucket detector. Here we propose and experimentally demonstrate a more rigorous and general approach in which a ghost image is retrieved by calculating a Pearson correlation coefficient between the bucket detector intensity and the brightness at a given pixel of the reference frames, and at the next pixel, and so on. Furthermore, we theoretically provide a statistical interpretation of these two imaging phenomena, and explain how the error depends on the sample size and what kind of distribution the error obeys. According to our analysis, the image signal-to-noise ratio can be greatly improved and the sampling number reduced by means of our new method. Project supported by the National Key Scientific Instrument and Equipment Development Project of China (Grant No. 2013YQ030595) and the National High Technology Research and Development Program of China (Grant No. 2013AA122902).

Pearson's Correlation between Three Variables; Using Students' Basic Knowledge of Geometry for an Exercise in Mathematical Statistics

ERIC Educational Resources Information Center

Vos, Pauline

2009-01-01

When studying correlations, how do the three bivariate correlation coefficients between three variables relate? After transforming Pearson's correlation coefficient r into a Euclidean distance, undergraduate students can tackle this problem using their secondary school knowledge of geometry (Pythagoras' theorem and similarity of triangles).…

Fast-GPU-PCC: A GPU-Based Technique to Compute Pairwise Pearson's Correlation Coefficients for Time Series Data-fMRI Study.

PubMed

Eslami, Taban; Saeed, Fahad

2018-04-20

Functional magnetic resonance imaging (fMRI) is a non-invasive brain imaging technique, which has been regularly used for studying brain’s functional activities in the past few years. A very well-used measure for capturing functional associations in brain is Pearson’s correlation coefficient. Pearson’s correlation is widely used for constructing functional network and studying dynamic functional connectivity of the brain. These are useful measures for understanding the effects of brain disorders on connectivities among brain regions. The fMRI scanners produce huge number of voxels and using traditional central processing unit (CPU)-based techniques for computing pairwise correlations is very time consuming especially when large number of subjects are being studied. In this paper, we propose a graphics processing unit (GPU)-based algorithm called Fast-GPU-PCC for computing pairwise Pearson’s correlation coefficient. Based on the symmetric property of Pearson’s correlation, this approach returns N ( N − 1 ) / 2 correlation coefficients located at strictly upper triangle part of the correlation matrix. Storing correlations in a one-dimensional array with the order as proposed in this paper is useful for further usage. Our experiments on real and synthetic fMRI data for different number of voxels and varying length of time series show that the proposed approach outperformed state of the art GPU-based techniques as well as the sequential CPU-based versions. We show that Fast-GPU-PCC runs 62 times faster than CPU-based version and about 2 to 3 times faster than two other state of the art GPU-based methods.

Pearson-type goodness-of-fit test with bootstrap maximum likelihood estimation.

PubMed

Yin, Guosheng; Ma, Yanyuan

2013-01-01

The Pearson test statistic is constructed by partitioning the data into bins and computing the difference between the observed and expected counts in these bins. If the maximum likelihood estimator (MLE) of the original data is used, the statistic generally does not follow a chi-squared distribution or any explicit distribution. We propose a bootstrap-based modification of the Pearson test statistic to recover the chi-squared distribution. We compute the observed and expected counts in the partitioned bins by using the MLE obtained from a bootstrap sample. This bootstrap-sample MLE adjusts exactly the right amount of randomness to the test statistic, and recovers the chi-squared distribution. The bootstrap chi-squared test is easy to implement, as it only requires fitting exactly the same model to the bootstrap data to obtain the corresponding MLE, and then constructs the bin counts based on the original data. We examine the test size and power of the new model diagnostic procedure using simulation studies and illustrate it with a real data set.

Quantifying colocalization by correlation: the Pearson correlation coefficient is superior to the Mander's overlap coefficient.

PubMed

Adler, Jeremy; Parmryd, Ingela

2010-08-01

The Pearson correlation coefficient (PCC) and the Mander's overlap coefficient (MOC) are used to quantify the degree of colocalization between fluorophores. The MOC was introduced to overcome perceived problems with the PCC. The two coefficients are mathematically similar, differing in the use of either the absolute intensities (MOC) or of the deviation from the mean (PCC). A range of correlated datasets, which extend to the limits of the PCC, only evoked a limited response from the MOC. The PCC is unaffected by changes to the offset while the MOC increases when the offset is positive. Both coefficients are independent of gain. The MOC is a confusing hybrid measurement, that combines correlation with a heavily weighted form of co-occurrence, favors high intensity combinations, downplays combinations in which either or both intensities are low and ignores blank pixels. The PCC only measures correlation. A surprising finding was that the addition of a second uncorrelated population can substantially increase the measured correlation, demonstrating the importance of excluding background pixels. Overall, since the MOC is unresponsive to substantial changes in the data and is hard to interpret, it is neither an alternative to nor a useful substitute for the PCC. The MOC is not suitable for making measurements of colocalization either by correlation or co-occurrence.

Correlation Between Posttraumatic Growth and Posttraumatic Stress Disorder Symptoms Based on Pearson Correlation Coefficient: A Meta-Analysis.

PubMed

Liu, An-Nuo; Wang, Lu-Lu; Li, Hui-Ping; Gong, Juan; Liu, Xiao-Hong

2017-05-01

The literature on posttraumatic growth (PTG) is burgeoning, with the inconsistencies in the literature of the relationship between PTG and posttraumatic stress disorder (PTSD) symptoms becoming a focal point of attention. Thus, this meta-analysis aims to explore the relationship between PTG and PTSD symptoms through the Pearson correlation coefficient. A systematic search of the literature from January 1996 to November 2015 was completed. We retrieved reports on 63 studies that involved 26,951 patients. The weighted correlation coefficient revealed an effect size of 0.22 with a 95% confidence interval of 0.18 to 0.25. Meta-analysis provides evidence that PTG may be positively correlated with PTSD symptoms and that this correlation may be modified by age, trauma type, and time since trauma. Accordingly, people with high levels of PTG should not be ignored, but rather, they should continue to receive help to alleviate their PTSD symptoms.

Asymptotic properties of Pearson's rank-variate correlation coefficient under contaminated Gaussian model.

PubMed

Ma, Rubao; Xu, Weichao; Zhang, Yun; Ye, Zhongfu

2014-01-01

This paper investigates the robustness properties of Pearson's rank-variate correlation coefficient (PRVCC) in scenarios where one channel is corrupted by impulsive noise and the other is impulsive noise-free. As shown in our previous work, these scenarios that frequently encountered in radar and/or sonar, can be well emulated by a particular bivariate contaminated Gaussian model (CGM). Under this CGM, we establish the asymptotic closed forms of the expectation and variance of PRVCC by means of the well known Delta method. To gain a deeper understanding, we also compare PRVCC with two other classical correlation coefficients, i.e., Spearman's rho (SR) and Kendall's tau (KT), in terms of the root mean squared error (RMSE). Monte Carlo simulations not only verify our theoretical findings, but also reveal the advantage of PRVCC by an example of estimating the time delay in the particular impulsive noise environment.

Pearson's Functions to Describe FSW Weld Geometry

NASA Astrophysics Data System (ADS)

Lacombe, D.; Gutierrez-Orrantia, M. E.; Coupard, D.; Tcherniaeff, S.; Girot, F.

2011-01-01

Friction stir welding (FSW) is a relatively new joining technique particularly for aluminium alloys that are difficult to fusion weld. In this study, the geometry of the weld has been investigated and modelled using Pearson's functions. It has been demonstrated that the Pearson's parameters (mean, standard deviation, skewness, kurtosis and geometric constant) can be used to characterize the weld geometry and the tensile strength of the weld assembly. Pearson's parameters and process parameters are strongly correlated allowing to define a control process procedure for FSW assemblies which make radiographic or ultrasonic controls unnecessary. Finally, an optimisation using a Generalized Gradient Method allows to determine the geometry of the weld which maximises the assembly tensile strength.

Fisher, Neyman-Pearson or NHST? A tutorial for teaching data testing.

PubMed

Perezgonzalez, Jose D

2015-01-01

Despite frequent calls for the overhaul of null hypothesis significance testing (NHST), this controversial procedure remains ubiquitous in behavioral, social and biomedical teaching and research. Little change seems possible once the procedure becomes well ingrained in the minds and current practice of researchers; thus, the optimal opportunity for such change is at the time the procedure is taught, be this at undergraduate or at postgraduate levels. This paper presents a tutorial for the teaching of data testing procedures, often referred to as hypothesis testing theories. The first procedure introduced is Fisher's approach to data testing-tests of significance; the second is Neyman-Pearson's approach-tests of acceptance; the final procedure is the incongruent combination of the previous two theories into the current approach-NSHT. For those researchers sticking with the latter, two compromise solutions on how to improve NHST conclude the tutorial.

Asymptotic confidence intervals for the Pearson correlation via skewness and kurtosis.

PubMed

Bishara, Anthony J; Li, Jiexiang; Nash, Thomas

2018-02-01

When bivariate normality is violated, the default confidence interval of the Pearson correlation can be inaccurate. Two new methods were developed based on the asymptotic sampling distribution of Fisher's z' under the general case where bivariate normality need not be assumed. In Monte Carlo simulations, the most successful of these methods relied on the (Vale & Maurelli, 1983, Psychometrika, 48, 465) family to approximate a distribution via the marginal skewness and kurtosis of the sample data. In Simulation 1, this method provided more accurate confidence intervals of the correlation in non-normal data, at least as compared to no adjustment of the Fisher z' interval, or to adjustment via the sample joint moments. In Simulation 2, this approximate distribution method performed favourably relative to common non-parametric bootstrap methods, but its performance was mixed relative to an observed imposed bootstrap and two other robust methods (PM1 and HC4). No method was completely satisfactory. An advantage of the approximate distribution method, though, is that it can be implemented even without access to raw data if sample skewness and kurtosis are reported, making the method particularly useful for meta-analysis. Supporting information includes R code. © 2017 The British Psychological Society.

Hapten-antibody recognition studies in competitive immunoassay of α-zearalanol analogs by computational chemistry and Pearson Correlation analysis.

PubMed

Wang, Zhanhui; Luo, Pengjie; Cheng, Linli; Zhang, Suxia; Shen, Jianzhong

2011-01-01

The molecular recognition of hapten-antibody is a fundamental event in competitive immunoassay, which guarantees the sensitivity and specificity of immunoassay for the detection of haptens. The aim of this study is to investigate the correlation between binding ability of one monoclonal antibody, 1H9B4, recognizing and the molecular aspects of α-zearalanol analogs. The mouse-derived monoclonal antibody was produced by using α-zearalanol conjugated to bovine serum albumin as an immunogen. The antibody recognition abilities, expressed as IC(50) values, were determined by a competitive ELISA. All of the hapten molecules were optimized by Density Function Theory (DFT) at B3LYP/ 6-31G* level and the conformation and electrostatic molecular isosurface were employed to explain the molecular recognition between α-zearalanol analogs and antibody 1H9B4. Pearson Correlation analysis between molecular descriptors and IC(50) values was qualitatively undertaken and the results showed that one molecular descriptor, surface of the hapten molecule, clearly demonstrated linear relationship with antibody recognition ability, where the relationship coefficient was 0.88 and the correlation was significant at p < 0.05 level. The study shows that computational chemistry and Pearson Correlation analysis can be used as tool to help the immunochemistries better understand the processing of antibody recognition of hapten molecules in competitive immunoassay. Copyright © 2011 John Wiley & Sons, Ltd.

Quantifying distinct associations on different temporal scales: comparison of DCCA and Pearson methods

NASA Astrophysics Data System (ADS)

Piao, Lin; Fu, Zuntao

2016-11-01

Cross-correlation between pairs of variables takes multi-time scale characteristic, and it can be totally different on different time scales (changing from positive correlation to negative one), e.g., the associations between mean air temperature and relative humidity over regions to the east of Taihang mountain in China. Therefore, how to correctly unveil these correlations on different time scales is really of great importance since we actually do not know if the correlation varies with scales in advance. Here, we compare two methods, i.e. Detrended Cross-Correlation Analysis (DCCA for short) and Pearson correlation, in quantifying scale-dependent correlations directly to raw observed records and artificially generated sequences with known cross-correlation features. Studies show that 1) DCCA related methods can indeed quantify scale-dependent correlations, but not Pearson method; 2) the correlation features from DCCA related methods are robust to contaminated noises, however, the results from Pearson method are sensitive to noise; 3) the scale-dependent correlation results from DCCA related methods are robust to the amplitude ratio between slow and fast components, while Pearson method may be sensitive to the amplitude ratio. All these features indicate that DCCA related methods take some advantages in correctly quantifying scale-dependent correlations, which results from different physical processes.

Quantifying distinct associations on different temporal scales: comparison of DCCA and Pearson methods.

PubMed

Piao, Lin; Fu, Zuntao

2016-11-09

Cross-correlation between pairs of variables takes multi-time scale characteristic, and it can be totally different on different time scales (changing from positive correlation to negative one), e.g., the associations between mean air temperature and relative humidity over regions to the east of Taihang mountain in China. Therefore, how to correctly unveil these correlations on different time scales is really of great importance since we actually do not know if the correlation varies with scales in advance. Here, we compare two methods, i.e. Detrended Cross-Correlation Analysis (DCCA for short) and Pearson correlation, in quantifying scale-dependent correlations directly to raw observed records and artificially generated sequences with known cross-correlation features. Studies show that 1) DCCA related methods can indeed quantify scale-dependent correlations, but not Pearson method; 2) the correlation features from DCCA related methods are robust to contaminated noises, however, the results from Pearson method are sensitive to noise; 3) the scale-dependent correlation results from DCCA related methods are robust to the amplitude ratio between slow and fast components, while Pearson method may be sensitive to the amplitude ratio. All these features indicate that DCCA related methods take some advantages in correctly quantifying scale-dependent correlations, which results from different physical processes.

A Psychometric Measurement Model for Adult English Language Learners: Pearson Test of English Academic

ERIC Educational Resources Information Center

Pae, Hye K.

2012-01-01

The aim of this study was to apply Rasch modeling to an examination of the psychometric properties of the "Pearson Test of English Academic" (PTE Academic). Analyzed were 140 test-takers' scores derived from the PTE Academic database. The mean age of the participants was 26.45 (SD = 5.82), ranging from 17 to 46. Conformity of the participants'…

Quantitative T2-Mapping and T2⁎-Mapping Evaluation of Changes in Cartilage Matrix after Acute Anterior Cruciate Ligament Rupture and the Correlation between the Results of Both Methods.

PubMed

Tao, Hongyue; Qiao, Yang; Hu, Yiwen; Xie, Yuxue; Lu, Rong; Yan, Xu; Chen, Shuang

2018-01-01

To quantitatively assess changes in cartilage matrix after acute anterior cruciate ligament (ACL) rupture using T2- and T2 ⁎ -mapping and analyze the correlation between the results of both methods. Twenty-three patients and 23 healthy controls were enrolled and underwent quantitative MRI examination. The knee cartilage was segmented into six compartments, including lateral femur (LF), lateral tibia (LT), medial femur (MF), medial tibia (MT), trochlea (Tr), and patella (Pa). T2 and T2 ⁎ values were measured in full-thickness as well as superficial and deep layers of each cartilage compartment. Differences of T2 and T2 ⁎ values between patients and controls were compared using unpaired Student's t -test, and the correlation between their reciprocals was analyzed using Pearson's correlation coefficient. ACL-ruptured patients showed higher T2 and T2 ⁎ values in full-thickness and superficial layers of medial and lateral tibiofemoral joint. Meanwhile, patients exhibited higher T2 ⁎ values in deep layers of lateral tibiofemoral joint. The elevated percentages of T2 and T2 ⁎ value in superficial LT were most significant (20.738%, 17.525%). The reciprocal of T2 ⁎ value was correlated with that of T2 value ( r = 0.886, P < 0.001). The early degeneration could occur in various knee cartilage compartments after acute ACL rupture, especially in the superficial layer of LT. T2 ⁎ -mapping might be more sensitive in detecting deep layer of cartilage than T2-mapping.

FRACTIONAL PEARSON DIFFUSIONS.

PubMed

Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla

2013-07-15

Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change.

Test Review: Kaufman, A. S., & Kaufman, N. L. (2014), "Kaufman Test of Educational Achievement, Third Edition." Bloomington, MN: NCS Pearson

ERIC Educational Resources Information Center

Frame, Laura B.; Vidrine, Stephanie M.; Hinojosa, Ryan

2016-01-01

The Kaufman Test of Educational Achievement, Third Edition (KTEA-3) is a revised and updated comprehensive academic achievement test (Kaufman & Kaufman, 2014). Authored by Drs. Alan and Nadeen Kaufman and published by Pearson, the KTEA-3 remains an individual achievement test normed for individuals of ages 4 through 25 years, or for those in…

Spatial trends in Pearson Type III statistical parameters

USGS Publications Warehouse

Lichty, R.W.; Karlinger, M.R.

1995-01-01

Spatial trends in the statistical parameters (mean, standard deviation, and skewness coefficient) of a Pearson Type III distribution of the logarithms of annual flood peaks for small rural basins (less than 90 km2) are delineated using a climate factor CT, (T=2-, 25-, and 100-yr recurrence intervals), which quantifies the effects of long-term climatic data (rainfall and pan evaporation) on observed T-yr floods. Maps showing trends in average parameter values demonstrate the geographically varying influence of climate on the magnitude of Pearson Type III statistical parameters. The spatial trends in variability of the parameter values characterize the sensitivity of statistical parameters to the interaction of basin-runoff characteristics (hydrology) and climate. -from Authors

Quantitative T2-Mapping and T2⁎-Mapping Evaluation of Changes in Cartilage Matrix after Acute Anterior Cruciate Ligament Rupture and the Correlation between the Results of Both Methods

PubMed Central

Tao, Hongyue; Qiao, Yang; Hu, Yiwen; Xie, Yuxue; Lu, Rong; Yan, Xu

2018-01-01

Objectives To quantitatively assess changes in cartilage matrix after acute anterior cruciate ligament (ACL) rupture using T2- and T2⁎-mapping and analyze the correlation between the results of both methods. Methods Twenty-three patients and 23 healthy controls were enrolled and underwent quantitative MRI examination. The knee cartilage was segmented into six compartments, including lateral femur (LF), lateral tibia (LT), medial femur (MF), medial tibia (MT), trochlea (Tr), and patella (Pa). T2 and T2⁎ values were measured in full-thickness as well as superficial and deep layers of each cartilage compartment. Differences of T2 and T2⁎ values between patients and controls were compared using unpaired Student's t-test, and the correlation between their reciprocals was analyzed using Pearson's correlation coefficient. Results ACL-ruptured patients showed higher T2 and T2⁎ values in full-thickness and superficial layers of medial and lateral tibiofemoral joint. Meanwhile, patients exhibited higher T2⁎ values in deep layers of lateral tibiofemoral joint. The elevated percentages of T2 and T2⁎ value in superficial LT were most significant (20.738%, 17.525%). The reciprocal of T2⁎ value was correlated with that of T2 value (r = 0.886, P < 0.001). Conclusion The early degeneration could occur in various knee cartilage compartments after acute ACL rupture, especially in the superficial layer of LT. T2⁎-mapping might be more sensitive in detecting deep layer of cartilage than T2-mapping. PMID:29888279

Biochemical abnormalities in Pearson syndrome.

PubMed

Crippa, Beatrice Letizia; Leon, Eyby; Calhoun, Amy; Lowichik, Amy; Pasquali, Marzia; Longo, Nicola

2015-03-01

Pearson marrow-pancreas syndrome is a multisystem mitochondrial disorder characterized by bone marrow failure and pancreatic insufficiency. Children who survive the severe bone marrow dysfunction in childhood develop Kearns-Sayre syndrome later in life. Here we report on four new cases with this condition and define their biochemical abnormalities. Three out of four patients presented with failure to thrive, with most of them having normal development and head size. All patients had evidence of bone marrow involvement that spontaneously improved in three out of four patients. Unique findings in our patients were acute pancreatitis (one out of four), renal Fanconi syndrome (present in all patients, but symptomatic only in one), and an unusual organic aciduria with 3-hydroxyisobutyric aciduria in one patient. Biochemical analysis indicated low levels of plasma citrulline and arginine, despite low-normal ammonia levels. Regression analysis indicated a significant correlation between each intermediate of the urea cycle and the next, except between ornithine and citrulline. This suggested that the reaction catalyzed by ornithine transcarbamylase (that converts ornithine to citrulline) might not be very efficient in patients with Pearson syndrome. In view of low-normal ammonia levels, we hypothesize that ammonia and carbamylphosphate could be diverted from the urea cycle to the synthesis of nucleotides in patients with Pearson syndrome and possibly other mitochondrial disorders. © 2015 Wiley Periodicals, Inc.

Pearson Syndrome, A Medical Diagnosis Difficult to Sustain Without Genetic Testing.

PubMed

Sur, Lucia; Floca, Emanuela; Samasca, Gabriel; Lupan, Iulia; Aldea, Cornel; Sur, Genel

2018-03-01

The detection of sideroblastic anemia in a newborn may suggest developing Pearson syndrome. The prognosis of these patients is severe and death occurs in the first 3 years of life, so it is important to find new ways of diagnosis. Case Presentation: In the case of our patient the diagnosis was supported only at the age of 5 months, highlighting the difficulties of diagnosis at this age. The diagnosis of Pearson syndrome with neonatal onset is difficult to sustain or even impossible at that age. This diagnosis can be confirmed and supported during disease progression.

A bootstrap based Neyman-Pearson test for identifying variable importance.

PubMed

Ditzler, Gregory; Polikar, Robi; Rosen, Gail

2015-04-01

Selection of most informative features that leads to a small loss on future data are arguably one of the most important steps in classification, data analysis and model selection. Several feature selection (FS) algorithms are available; however, due to noise present in any data set, FS algorithms are typically accompanied by an appropriate cross-validation scheme. In this brief, we propose a statistical hypothesis test derived from the Neyman-Pearson lemma for determining if a feature is statistically relevant. The proposed approach can be applied as a wrapper to any FS algorithm, regardless of the FS criteria used by that algorithm, to determine whether a feature belongs in the relevant set. Perhaps more importantly, this procedure efficiently determines the number of relevant features given an initial starting point. We provide freely available software implementations of the proposed methodology.

Pearson-Readhead survey from space

NASA Astrophysics Data System (ADS)

Preston, R. A.; Lister, M. L.; Tingay, S. J.; Piner, B. G.; Murphy, D. W.; Jones, D. L.; Meier, D. L.; Pearson, T. J.; Readhead, A. C. S.; Hirabayashi, H.; Kobayashi, H.; Inoue, M.

2001-01-01

We are using the VSOP space VLBI mission to observe a complete sample of Pearson-Readhead survey sources at 4.8 GHz to determine core brightness temperatures and pc-scale jet properties. The Pearson-Readhead sample has been used for extensive ground-based VLBI survey studies, and is ideal for a VSOP survey because the sources are strong, the VSOP u-v coverages are especially good above +35o declination, and multi-epoch ground-based VLBI data and other existing supporting data exceed that of any other sample. To date we have imaged 27 of the 31 objects in our sample. Our preliminary results show that the majority of objects contain strong core components that remain unresolved on baselines of ~30,000 km. The brightness temperatures of several cores significantly exceed 1012 K, which is indicative of highly relativistically beamed emission. We discuss correlations with several other beaming indicators, such as variability and spectral index, that support this scenario. This research was performed in part at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA.

Correlation between T2* cardiovascular magnetic resonance with left ventricular function and mass in adolescent and adult major thalassemia patients with iron overload.

PubMed

Djer, Mulyadi M; Anggriawan, Shirley L; Gatot, Djajadiman; Amalia, Pustika; Sastroasmoro, Sudigdo; Widjaja, Patricia

2013-10-01

to assess for a correlation between T2*CMR with LV function and mass in thalassemic patients with iron overload. a cross-sectional study on thalassemic patients was conducted between July and September 2010 at Cipto Mangunkusumo and Premier Hospitals, Jakarta, Indonesia. Clinical examinations, review of medical charts, electrocardiography, echocardiography, and T2*CMR were performed. Cardiac siderosis was measured by T2*CMR conduction time. Left ventricle diastolic and systolic functions, as well as LV mass index were measured using echocardiography. Correlations between T2*CMR and echocardiography findings, as well as serum ferritin were determined using Pearson's and Spearman's tests. thirty patients aged 13-41 years were enrolled, of whom two-thirds had -thalassemia major and one-third had HbE/-thalassemia. Diastolic dysfunction was identified in 8 patients, whereas systolic function was normal in all patients. Increased LV mass index was found in 3 patients. T2*CMR conduction times ranged from 8.98 to 55.04 ms and a value below 20 ms was demonstrated in 14 patients. There was a statistically significant moderate positive correlation of T2*CMR conduction time with E/A ratio (r = 0.471, P = 0.009), but no correlation was found with LV mass index (r=0.097, P=0.608). A moderate negative correlation was found between T2*CMR and serum ferritin (r = -0.514, P = 0.004), while a moderate negative correlation was found between serum ferritin and E/A ratio (r = -0.425, P = 0.019). T2*CMR myocardial conduction time has a moderate positive correlation with diastolic function, moderate negative correlation with serum ferritin, but not with LV mass index and systolic function.

Correcting Two-Sample "z" and "t" Tests for Correlation: An Alternative to One-Sample Tests on Difference Scores

ERIC Educational Resources Information Center

Zimmerman, Donald W.

2012-01-01

In order to circumvent the influence of correlation in paired-samples and repeated measures experimental designs, researchers typically perform a one-sample Student "t" test on difference scores. That procedure entails some loss of power, because it employs N - 1 degrees of freedom instead of the 2N - 2 degrees of freedom of the…

Comparing the Pearson and Spearman correlation coefficients across distributions and sample sizes: A tutorial using simulations and empirical data.

PubMed

de Winter, Joost C F; Gosling, Samuel D; Potter, Jeff

2016-09-01

The Pearson product–moment correlation coefficient ( r p ) and the Spearman rank correlation coefficient ( r s ) are widely used in psychological research. We compare r p and r s on 3 criteria: variability, bias with respect to the population value, and robustness to an outlier. Using simulations across low (N = 5) to high (N = 1,000) sample sizes we show that, for normally distributed variables, r p and r s have similar expected values but r s is more variable, especially when the correlation is strong. However, when the variables have high kurtosis, r p is more variable than r s . Next, we conducted a sampling study of a psychometric dataset featuring symmetrically distributed data with light tails, and of 2 Likert-type survey datasets, 1 with light-tailed and the other with heavy-tailed distributions. Consistent with the simulations, r p had lower variability than r s in the psychometric dataset. In the survey datasets with heavy-tailed variables in particular, r s had lower variability than r p , and often corresponded more accurately to the population Pearson correlation coefficient ( R p ) than r p did. The simulations and the sampling studies showed that variability in terms of standard deviations can be reduced by about 20% by choosing r s instead of r p . In comparison, increasing the sample size by a factor of 2 results in a 41% reduction of the standard deviations of r s and r p . In conclusion, r p is suitable for light-tailed distributions, whereas r s is preferable when variables feature heavy-tailed distributions or when outliers are present, as is often the case in psychological research. PsycINFO Database Record (c) 2016 APA, all rights reserved

Correlations between the Hand Test Pathology score and Personality Assessment Inventory scales for pain clinic patients.

PubMed

George, J M; Wagner, E E

1995-06-01

Pearson correlations between the Hand Test Pathology (PATH) score and Personality Assessment Inventory scales produced a cluster of relationships characteristic of an antisocial orientation. Likewise, PATH significantly differentiated between a "P" (Pathology) group flagged by a high Negative Impression score on the inventory, and an "N" (Normal) group of 100 pain patients. It was suggested that the interpretive simplicity of Hand Test scores renders the scores amenable to further correlational studies involving the inventory.

Method for stationarity-segmentation of spike train data with application to the Pearson cross-correlation.

PubMed

Quiroga-Lombard, Claudio S; Hass, Joachim; Durstewitz, Daniel

2013-07-01

Correlations among neurons are supposed to play an important role in computation and information coding in the nervous system. Empirically, functional interactions between neurons are most commonly assessed by cross-correlation functions. Recent studies have suggested that pairwise correlations may indeed be sufficient to capture most of the information present in neural interactions. Many applications of correlation functions, however, implicitly tend to assume that the underlying processes are stationary. This assumption will usually fail for real neurons recorded in vivo since their activity during behavioral tasks is heavily influenced by stimulus-, movement-, or cognition-related processes as well as by more general processes like slow oscillations or changes in state of alertness. To address the problem of nonstationarity, we introduce a method for assessing stationarity empirically and then "slicing" spike trains into stationary segments according to the statistical definition of weak-sense stationarity. We examine pairwise Pearson cross-correlations (PCCs) under both stationary and nonstationary conditions and identify another source of covariance that can be differentiated from the covariance of the spike times and emerges as a consequence of residual nonstationarities after the slicing process: the covariance of the firing rates defined on each segment. Based on this, a correction of the PCC is introduced that accounts for the effect of segmentation. We probe these methods both on simulated data sets and on in vivo recordings from the prefrontal cortex of behaving rats. Rather than for removing nonstationarities, the present method may also be used for detecting significant events in spike trains.

How accurate is the Pearson r-from-Z approximation? A Monte Carlo simulation study.

PubMed

Hittner, James B; May, Kim

2012-01-01

The Pearson r-from-Z approximation estimates the sample correlation (as an effect size measure) from the ratio of two quantities: the standard normal deviate equivalent (Z-score) corresponding to a one-tailed p-value divided by the square root of the total (pooled) sample size. The formula has utility in meta-analytic work when reports of research contain minimal statistical information. Although simple to implement, the accuracy of the Pearson r-from-Z approximation has not been empirically evaluated. To address this omission, we performed a series of Monte Carlo simulations. Results indicated that in some cases the formula did accurately estimate the sample correlation. However, when sample size was very small (N = 10) and effect sizes were small to small-moderate (ds of 0.1 and 0.3), the Pearson r-from-Z approximation was very inaccurate. Detailed figures that provide guidance as to when the Pearson r-from-Z formula will likely yield valid inferences are presented.

Parental Socio-Economic Status as Correlate of Child Labour in Ile-Ife, Nigeria

ERIC Educational Resources Information Center

Elegbeleye, O. S.; Olasupo, M. O.

2012-01-01

This study investigated the relationship between parental socio-economic status and child labour practices in Ile-Ife, Nigeria. The study employed survey method to gather data from 200 parents which constituted the study population. Pearson Product Moment Correlation and t-test statistics were used for the data analyses. The outcome of the study…

Quantification of myocardial oxygenation in heart failure using blood-oxygen-level-dependent T2* magnetic resonance imaging: Comparison with cardiopulmonary exercise test.

PubMed

Nagao, Michinobu; Yamasaki, Yuzo; Kawanami, Satoshi; Kamitani, Takeshi; Sagiyama, Koji; Higo, Taiki; Ide, Tomomi; Takemura, Atsushi; Ishizaki, Umiko; Fukushima, Kenji; Watanabe, Yuji; Honda, Hiroshi

2017-06-01

Quantification of myocardial oxygenation (MO) in heart failure (HF) has been less than satisfactory. This has necessitated the use of invasive techniques to measure MO directly or to determine the oxygen demand during exercise using the cardiopulmonary exercise (CPX) test. We propose a new quantification method for MO using blood-oxygen-level-dependent (BOLD) myocardial T2* magnetic resonance imaging (M-T2* MRI), and investigate its correlation with CPX results. Thirty patients with refractory HF who underwent cardiac MRI and CPX test for heart transplantation, and 24 healthy, age-matched volunteers as controls were enrolled. M-T2* imaging was performed using a 3-Tesla and multi-echo gradient-echo sequence. M-T2* was calculated by fitting the signal intensity data for the mid-left ventricular septum to a decay curve. M-T2* was measured under room-air (T2*-air) and after inhalation of oxygen for 10min at a flow rate of 10L/min (T2*-oxy). MO was defined as the difference between the two values (ΔT2*). Changes in M-T2* at the two conditions and ΔT2* between the two groups were compared. Correlation between ΔT2* and CPX results was analyzed using the Pearson coefficient. T2*-oxy was significantly greater than T2*-air in patients with HF (29.9±7.3ms vs. 26.7±6.0ms, p<0.001), whereas no such difference was observed in controls (25.5±4.0ms vs. 25.4±4.4ms). ΔT2* was significantly greater for patients with HF than for controls (3.2±4.5ms vs. -0.1±1.3ms, p<0.001). A significant correlation between ΔT2* and CPX results (peak VO 2 , r=-0.46, p<0.05; O 2 pulse, r=-0.54, p<0.005) was observed. ΔT2* is increased T2*-oxy is greater in patients with HF, and is correlated with oxygen metabolism during exercise as measured by the CPX test. Hence, ΔT2* can be used as a surrogate marker of MO instead of CPX test. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparing Pearson, Spearman and Hoeffding's D measure for gene expression association analysis.

PubMed

Fujita, André; Sato, João Ricardo; Demasi, Marcos Angelo Almeida; Sogayar, Mari Cleide; Ferreira, Carlos Eduardo; Miyano, Satoru

2009-08-01

DNA microarrays have become a powerful tool to describe gene expression profiles associated with different cellular states, various phenotypes and responses to drugs and other extra- or intra-cellular perturbations. In order to cluster co-expressed genes and/or to construct regulatory networks, definition of distance or similarity between measured gene expression data is usually required, the most common choices being Pearson's and Spearman's correlations. Here, we evaluate these two methods and also compare them with a third one, namely Hoeffding's D measure, which is used to infer nonlinear and non-monotonic associations, i.e. independence in a general sense. By comparing three different variable association approaches, namely Pearson's correlation, Spearman's correlation and Hoeffding's D measure, we aimed at assessing the most appropriate one for each purpose. Using simulations, we demonstrate that the Hoeffding's D measure outperforms Pearson's and Spearman's approaches in identifying nonlinear associations. Our results demonstrate that Hoeffding's D measure is less sensitive to outliers and is a more powerful tool to identify nonlinear and non-monotonic associations. We have also applied Hoeffding's D measure in order to identify new putative genes associated with tp53. Therefore, we propose the Hoeffding's D measure to identify nonlinear associations between gene expression profiles.

Correlation of Gerkin, Queen's College, George, and Jackson methods in estimating maximal oxygen consumption.

PubMed

Heydari, Payam; Varmazyar, Sakineh; Variani, Ali Safari; Hashemi, Fariba; Ataei, Seyed Sajad

2017-10-01

Test of maximal oxygen consumption is the gold standard for measuring cardio-pulmonary fitness. This study aimed to determine correlation of Gerkin, Queen's College, George, and Jackson methods in estimating maximal oxygen consumption, and demographic factors affecting maximal oxygen consumption. This descriptive cross-sectional study was conducted in a census of medical emergency students (n=57) in Qazvin University of Medical Sciences in 2016. The subjects firstly completed the General Health Questionnaire (PAR-Q) and demographic characteristics. Then eligible subjects were assessed using exercise tests of Gerkin treadmill, Queen's College steps and non-exercise George, and Jackson. Data analysis was carried out using independent t-test, one way analysis of variance and Pearson correlation in the SPSS software. The mean age of participants was 21.69±4.99 years. The mean of maximal oxygen consumption using Gerkin, Queen's College, George, and Jackson tests was 4.17, 3.36, 3.64, 3.63 liters per minute, respectively. Pearson statistical test showed a significant correlation among fours tests. George and Jackson tests had the greatest correlation (r=0.85, p>0.001). Results of tests of one-way analysis of variance and t-test showed a significant relationship between independent variable of weight and height in four tests, and dependent variable of maximal oxygen consumption. Also, there was a significant relationship between variable of body mass index in two tests of Gerkin and Queen's College and variable of exercise hours per week with the George and Jackson tests (p>0.001). Given the obtained correlation, these tests have the potential to replace each other as necessary, so that the non-exercise Jackson test can be used instead of the Gerkin test.

A new method to detect event-related potentials based on Pearson's correlation.

PubMed

Giroldini, William; Pederzoli, Luciano; Bilucaglia, Marco; Melloni, Simone; Tressoldi, Patrizio

2016-12-01

Event-related potentials (ERPs) are widely used in brain-computer interface applications and in neuroscience.  Normal EEG activity is rich in background noise, and therefore, in order to detect ERPs, it is usually necessary to take the average from multiple trials to reduce the effects of this noise.  The noise produced by EEG activity itself is not correlated with the ERP waveform and so, by calculating the average, the noise is decreased by a factor inversely proportional to the square root of N , where N is the number of averaged epochs. This is the easiest strategy currently used to detect ERPs, which is based on calculating the average of all ERP's waveform, these waveforms being time- and phase-locked.  In this paper, a new method called GW6 is proposed, which calculates the ERP using a mathematical method based only on Pearson's correlation. The result is a graph with the same time resolution as the classical ERP and which shows only positive peaks representing the increase-in consonance with the stimuli-in EEG signal correlation over all channels.  This new method is also useful for selectively identifying and highlighting some hidden components of the ERP response that are not phase-locked, and that are usually hidden in the standard and simple method based on the averaging of all the epochs.  These hidden components seem to be caused by variations (between each successive stimulus) of the ERP's inherent phase latency period (jitter), although the same stimulus across all EEG channels produces a reasonably constant phase. For this reason, this new method could be very helpful to investigate these hidden components of the ERP response and to develop applications for scientific and medical purposes. Moreover, this new method is more resistant to EEG artifacts than the standard calculations of the average and could be very useful in research and neurology.  The method we are proposing can be directly used in the form of a process written in the well

The Dichotic Digits difference Test (DDdT): Development, Normative Data, and Test-Retest Reliability Studies Part 1.

PubMed

Cameron, Sharon; Glyde, Helen; Dillon, Harvey; Whitfield, Jessica; Seymour, John

2016-06-01

The dichotic digits test is one of the most widely used assessment tools for central auditory processing disorder. However, questions remain concerning the impact of cognitive factors on test results. To develop the Dichotic Digits difference Test (DDdT), an assessment tool that could differentiate children with cognitive deficits from children with genuine dichotic deficits based on differential test results. The DDdT consists of four subtests: dichotic free recall (FR), dichotic directed left ear (DLE), dichotic directed right ear (DRE), and diotic. Scores for six conditions are calculated (FR left ear [LE], FR right ear [RE], and FR total, as well as DLE, DRE, and diotic). Scores for four difference measures are also calculated: dichotic advantage, right-ear advantage (REA) FR, REA directed, and attention advantage. Experiment 1 involved development of the DDdT, including error rate analysis. Experiment 2 involved collection of normative and test-retest reliability data. Twenty adults (aged 25 yr 10 mo to 50 yr 7 mo, mean 36 yr 4 mo) took part in the development study; 62 normal-hearing, typically developing, primary-school children (aged 7 yr 1 mo to 11 yr 11 mo, mean 9 yr 4 mo) and 10 adults (aged 25 yr 0 mo to 51 yr 6 mo, mean 34 yr 10 mo) took part in the normative and test-retest reliability study. In Experiment 1, error rate analysis was conducted on the 36 digit-pair combinations of the DDdT. Normative data collected in Experiment 2 were arcsine transformed to achieve a distribution that was closer to a normal distribution and z-scores calculated. Pearson product-moment correlations were used to determine the strength of relationships between DDdT conditions. The development study revealed no significant differences in the adult population between test and retest on any DDdT condition. Error rates on 36 digit pairs ranged from 1.5% to 16.7%. The most and the least error-prone digits were removed before commencement of the normative data study, leaving 25

Clinical correlation between the 6-min walk test andcardiopulmonary exercise testing in patients with pulmonary arterial hypertension.

PubMed

Acar, Serap; Savcı, Sema; Kardibak, Didem; Özcan Kahraman, Buse; Akdeniz, Bahri; Özpelit, Ebru; Sevinç, Can

2016-12-20

The aims of the present study were to assess the relationship between the distance walked during the 6-min walk test (6MWT) and exercise capacity as determined by cardiopulmonary exercise testing (CPET) in patients with pulmonary arterial hypertension (PAH) and to investigate the prognostic value of the 6MWT in comparison to clinical parameters of CPET and echocardiography findings. Thirty PAH patients participated in the study. Subject characteristics and New York Heart Association (NYHA) classifications were recorded. All subjects completed the 6MWT and CPET. Relationships among the variables were analyzed by the Pearson correlation test. Correlation coefficients between 6MWT distance and other variables were determined by linear regression analysis. Distance walked in the 6MWT was significantly correlated with the following exercise parameters: peak oxygen consumption, work load, and metabolic equivalents. Additionally, cardiac index was correlated with peak oxygen consumption and metabolic equivalents. We also showed that cardiac index and age were two significant determinants for exercise performance, accounting for 35.4% of the variance in the 6MWT. The 6MWT provides information that may be a better index for the patient's NYHA functional class determination than maximal exercise testing.

Functional connectivity and structural covariance between regions of interest can be measured more accurately using multivariate distance correlation.

PubMed

Geerligs, Linda; Cam-Can; Henson, Richard N

2016-07-15

Studies of brain-wide functional connectivity or structural covariance typically use measures like the Pearson correlation coefficient, applied to data that have been averaged across voxels within regions of interest (ROIs). However, averaging across voxels may result in biased connectivity estimates when there is inhomogeneity within those ROIs, e.g., sub-regions that exhibit different patterns of functional connectivity or structural covariance. Here, we propose a new measure based on "distance correlation"; a test of multivariate dependence of high dimensional vectors, which allows for both linear and non-linear dependencies. We used simulations to show how distance correlation out-performs Pearson correlation in the face of inhomogeneous ROIs. To evaluate this new measure on real data, we use resting-state fMRI scans and T1 structural scans from 2 sessions on each of 214 participants from the Cambridge Centre for Ageing & Neuroscience (Cam-CAN) project. Pearson correlation and distance correlation showed similar average connectivity patterns, for both functional connectivity and structural covariance. Nevertheless, distance correlation was shown to be 1) more reliable across sessions, 2) more similar across participants, and 3) more robust to different sets of ROIs. Moreover, we found that the similarity between functional connectivity and structural covariance estimates was higher for distance correlation compared to Pearson correlation. We also explored the relative effects of different preprocessing options and motion artefacts on functional connectivity. Because distance correlation is easy to implement and fast to compute, it is a promising alternative to Pearson correlations for investigating ROI-based brain-wide connectivity patterns, for functional as well as structural data. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

More accurate, calibrated bootstrap confidence intervals for correlating two autocorrelated climate time series

NASA Astrophysics Data System (ADS)

Olafsdottir, Kristin B.; Mudelsee, Manfred

2013-04-01

Estimation of the Pearson's correlation coefficient between two time series to evaluate the influences of one time depended variable on another is one of the most often used statistical method in climate sciences. Various methods are used to estimate confidence interval to support the correlation point estimate. Many of them make strong mathematical assumptions regarding distributional shape and serial correlation, which are rarely met. More robust statistical methods are needed to increase the accuracy of the confidence intervals. Bootstrap confidence intervals are estimated in the Fortran 90 program PearsonT (Mudelsee, 2003), where the main intention was to get an accurate confidence interval for correlation coefficient between two time series by taking the serial dependence of the process that generated the data into account. However, Monte Carlo experiments show that the coverage accuracy for smaller data sizes can be improved. Here we adapt the PearsonT program into a new version called PearsonT3, by calibrating the confidence interval to increase the coverage accuracy. Calibration is a bootstrap resampling technique, which basically performs a second bootstrap loop or resamples from the bootstrap resamples. It offers, like the non-calibrated bootstrap confidence intervals, robustness against the data distribution. Pairwise moving block bootstrap is used to preserve the serial correlation of both time series. The calibration is applied to standard error based bootstrap Student's t confidence intervals. The performances of the calibrated confidence intervals are examined with Monte Carlo simulations, and compared with the performances of confidence intervals without calibration, that is, PearsonT. The coverage accuracy is evidently better for the calibrated confidence intervals where the coverage error is acceptably small (i.e., within a few percentage points) already for data sizes as small as 20. One form of climate time series is output from numerical models

A powerful nonparametric method for detecting differentially co-expressed genes: distance correlation screening and edge-count test.

PubMed

Zhang, Qingyang

2018-05-16

Differential co-expression analysis, as a complement of differential expression analysis, offers significant insights into the changes in molecular mechanism of different phenotypes. A prevailing approach to detecting differentially co-expressed genes is to compare Pearson's correlation coefficients in two phenotypes. However, due to the limitations of Pearson's correlation measure, this approach lacks the power to detect nonlinear changes in gene co-expression which is common in gene regulatory networks. In this work, a new nonparametric procedure is proposed to search differentially co-expressed gene pairs in different phenotypes from large-scale data. Our computational pipeline consisted of two main steps, a screening step and a testing step. The screening step is to reduce the search space by filtering out all the independent gene pairs using distance correlation measure. In the testing step, we compare the gene co-expression patterns in different phenotypes by a recently developed edge-count test. Both steps are distribution-free and targeting nonlinear relations. We illustrate the promise of the new approach by analyzing the Cancer Genome Atlas data and the METABRIC data for breast cancer subtypes. Compared with some existing methods, the new method is more powerful in detecting nonlinear type of differential co-expressions. The distance correlation screening can greatly improve computational efficiency, facilitating its application to large data sets.

Developing a bivariate spatial association measure: An integration of Pearson's r and Moran's I

NASA Astrophysics Data System (ADS)

Lee, Sang-Il

This research is concerned with developing a bivariate spatial association measure or spatial correlation coefficient, which is intended to capture spatial association among observations in terms of their point-to-point relationships across two spatial patterns. The need for parameterization of the bivariate spatial dependence is precipitated by the realization that aspatial bivariate association measures, such as Pearson's correlation coefficient, do not recognize spatial distributional aspects of data sets. This study devises an L statistic by integrating Pearson's r as an aspatial bivariate association measure and Moran's I as a univariate spatial association measure. The concept of a spatial smoothing scalar (SSS) plays a pivotal role in this task.

Correlation between Colon Transit Time Test Value and Initial Maintenance Dose of Laxative in Children with Chronic Functional Constipation

PubMed Central

Kim, Mock Ryeon; Park, Hye Won; Son, Jae Sung; Lee, Ran

2016-01-01

Purpose To evaluate the correlation between colon transit time (CTT) test value and initial maintenance dose of polyethylene glycol (PEG) 4000 or lactulose. Methods Of 415 children with chronic functional constipation, 190 were enrolled based on exclusion criteria using the CTT test, defecation diary, and clinical chart. The CTT test was performed with prior disimpaction. The laxative dose for maintenance was determined on the basis of the defecation diary and clinical chart. The Shapiro-Wilk test and Pearson's and Spearman's correlations were used for statistical analysis. Results The overall group median value and interquartile range of the CTT test was 43.8 (31.8) hours. The average PEG 4000 dose for maintenance in the overall group was 0.68±0.18 g/kg/d; according to age, the dose was 0.73±0.16 g/kg/d (<8 years), 0.53±0.12 g/kg/d (8 to <12 years), and 0.36±0.05 g/kg/d (12 to 15 years). The dose of lactulose was 1.99±0.43 mL/kg/d (<8 years) or 1.26±0.25 mL/kg/d (8 to <12 years). There was no significant correlation between CTT test value and initial dose of laxative, irrespective of the subgroup (encopresis, abnormal CTT test subtype) for either laxative. Even in the largest group (overall, n=109, younger than 8 years and on PEG 4000), the correlation was weak (Pearson's correlation coefficient [R]=0.268, p=0.005). Within the abnormal transit group, subgroup (n=73, younger than 8 years and on PEG 4000) correlation was weak (R=0.267, p=0.022). Conclusion CTT test value cannot predict the initial maintenance dose of PEG 4000 or lactulose with linear correlation. PMID:27738600

Correlation between Colon Transit Time Test Value and Initial Maintenance Dose of Laxative in Children with Chronic Functional Constipation.

PubMed

Kim, Mock Ryeon; Park, Hye Won; Son, Jae Sung; Lee, Ran; Bae, Sun Hwan

2016-09-01

To evaluate the correlation between colon transit time (CTT) test value and initial maintenance dose of polyethylene glycol (PEG) 4000 or lactulose. Of 415 children with chronic functional constipation, 190 were enrolled based on exclusion criteria using the CTT test, defecation diary, and clinical chart. The CTT test was performed with prior disimpaction. The laxative dose for maintenance was determined on the basis of the defecation diary and clinical chart. The Shapiro-Wilk test and Pearson's and Spearman's correlations were used for statistical analysis. The overall group median value and interquartile range of the CTT test was 43.8 (31.8) hours. The average PEG 4000 dose for maintenance in the overall group was 0.68±0.18 g/kg/d; according to age, the dose was 0.73±0.16 g/kg/d (<8 years), 0.53±0.12 g/kg/d (8 to <12 years), and 0.36±0.05 g/kg/d (12 to 15 years). The dose of lactulose was 1.99±0.43 mL/kg/d (<8 years) or 1.26±0.25 mL/kg/d (8 to <12 years). There was no significant correlation between CTT test value and initial dose of laxative, irrespective of the subgroup (encopresis, abnormal CTT test subtype) for either laxative. Even in the largest group (overall, n=109, younger than 8 years and on PEG 4000), the correlation was weak (Pearson's correlation coefficient [R]=0.268, p =0.005). Within the abnormal transit group, subgroup (n=73, younger than 8 years and on PEG 4000) correlation was weak (R=0.267, p =0.022). CTT test value cannot predict the initial maintenance dose of PEG 4000 or lactulose with linear correlation.

Patellofemoral instability in children: T2 relaxation times of the patellar cartilage in patients with and without patellofemoral instability and correlation with morphological grading of cartilage damage.

PubMed

Kang, Chang Ho; Kim, Hee Kyung; Shiraj, Sahar; Anton, Christopher; Kim, Dong Hoon; Horn, Paul S

2016-07-01

Patellofemoral instability is one of the most common causes of cartilage damage in teenagers. To quantitatively evaluate the patellar cartilage in patients with patellofemoral instability using T2 relaxation time maps (T2 maps), compare the values to those in patients without patellofemoral instability and correlate them with morphological grades in patients with patellofemoral instability. Fifty-three patients with patellofemoral instability (mean age: 15.9 ± 2.4 years) and 53 age- and gender-matched patients without patellofemoral instability were included. Knee MR with axial T2 map was performed. Mean T2 relaxation times were obtained at the medial, central and lateral zones of the patellar cartilage and compared between the two groups. In the patellofemoral instability group, morphological grading of the patellar cartilage (0-4) was performed and correlated with T2 relaxation times. Mean T2 relaxation times were significantly longer in the group with patellofemoral instability as compared to those of the control group across the patellar cartilage (Student's t-test, P<0.05) with the longest time at the central area. Positive correlation was seen between mean T2 relaxation time and morphological grading (Pearson correlation coefficiency, P<0.001). T2 increased with severity of morphological grading from 0 to 3 (mixed model, P<0.001), but no statistical difference was seen between grades 3 and 4. In patellofemoral instability, patellar cartilage damage occurs across the entire cartilage with the highest T2 values at the apex. T2 relaxation times directly reflect the severity in low-grade cartilage damage, which implies an important role for T2 maps in differentiating between normal and low-grade cartilage damage.

[Neonatal Pearson syndrome. two case studies].

PubMed

Collin-Ducasse, H; Maillotte, A-M; Monpoux, F; Boutté, P; Ferrero-Vacher, C; Paquis, V

2010-01-01

Among the etiologies of anemia in the newborn, those related to mitochondrial cytopathies are rare. Pearson syndrome is mostly diagnosed during infancy and characterized by refractory sideroblastic anemia with vacuolization of marrow progenitor cells and exocrine pancreatic dysfunction. We describe two diagnosed cases of Pearson syndrome in the early neonatal period caused by severe macrocytic aregenerative anemia. Bone marrow aspiration revealed sideroblastic anemia and vacuolization of erythroblastic precursors. The diagnosis was confirmed by genetic analysis revealing a deletion in the mitochondrial DNA. These two newborns received monthly transfusions. Five other newborns suffering from Pearson syndrome with various clinical symptoms were found in literature. Pearson syndrome, rarely diagnosed in newborns, should be suspected in the presence of macrocytic aregenerative anemia and requires a bone marrow aspirate followed by a genetic analysis from a blood sample. Copyright 2009 Elsevier Masson SAS. All rights reserved.

[Calculating Pearson residual in logistic regressions: a comparison between SPSS and SAS].

PubMed

Xu, Hao; Zhang, Tao; Li, Xiao-song; Liu, Yuan-yuan

2015-01-01

To compare the results of Pearson residual calculations in logistic regression models using SPSS and SAS. We reviewed Pearson residual calculation methods, and used two sets of data to test logistic models constructed by SPSS and STATA. One model contained a small number of covariates compared to the number of observed. The other contained a similar number of covariates as the number of observed. The two software packages produced similar Pearson residual estimates when the models contained a similar number of covariates as the number of observed, but the results differed when the number of observed was much greater than the number of covariates. The two software packages produce different results of Pearson residuals, especially when the models contain a small number of covariates. Further studies are warranted.

[Pearson syndrome. Case report].

PubMed

Cammarata-Scalisi, Francisco; López-Gallardo, Ester; Emperador, Sonia; Ruiz-Pesini, Eduardo; Da Silva, Gloria; Camacho, Nolis; Montoya, Julio

2011-09-01

Among the etiologies of anemia in the infancy, the mitochondrial cytopathies are infrequent. Pearson syndrome is diagnosed principally during the initial stages of life and it is characterized by refractory sideroblastic anemia with vacuolization of marrow progenitor cells, exocrine pancreatic dysfunction and variable neurologic, hepatic, renal and endocrine failures. We report the case of a 14 month-old girl evaluated by a multicentric study, with clinic and molecular diagnosis of Pearson syndrome, with the 4,977-base pair common deletion of mitochondrial DNA. This entity has been associated to diverse phenotypes within the broad clinical spectrum of mitochondrial disease.

Correlation of Simulation Examination to Written Test Scores for Advanced Cardiac Life Support Testing: Prospective Cohort Study.

PubMed

Strom, Suzanne L; Anderson, Craig L; Yang, Luanna; Canales, Cecilia; Amin, Alpesh; Lotfipour, Shahram; McCoy, C Eric; Osborn, Megan Boysen; Langdorf, Mark I

2015-11-01

Traditional Advanced Cardiac Life Support (ACLS) courses are evaluated using written multiple-choice tests. High-fidelity simulation is a widely used adjunct to didactic content, and has been used in many specialties as a training resource as well as an evaluative tool. There are no data to our knowledge that compare simulation examination scores with written test scores for ACLS courses. To compare and correlate a novel high-fidelity simulation-based evaluation with traditional written testing for senior medical students in an ACLS course. We performed a prospective cohort study to determine the correlation between simulation-based evaluation and traditional written testing in a medical school simulation center. Students were tested on a standard acute coronary syndrome/ventricular fibrillation cardiac arrest scenario. Our primary outcome measure was correlation of exam results for 19 volunteer fourth-year medical students after a 32-hour ACLS-based Resuscitation Boot Camp course. Our secondary outcome was comparison of simulation-based vs. written outcome scores. The composite average score on the written evaluation was substantially higher (93.6%) than the simulation performance score (81.3%, absolute difference 12.3%, 95% CI [10.6-14.0%], p<0.00005). We found a statistically significant moderate correlation between simulation scenario test performance and traditional written testing (Pearson r=0.48, p=0.04), validating the new evaluation method. Simulation-based ACLS evaluation methods correlate with traditional written testing and demonstrate resuscitation knowledge and skills. Simulation may be a more discriminating and challenging testing method, as students scored higher on written evaluation methods compared to simulation.

Statistical tests for power-law cross-correlated processes

NASA Astrophysics Data System (ADS)

Podobnik, Boris; Jiang, Zhi-Qiang; Zhou, Wei-Xing; Stanley, H. Eugene

2011-12-01

For stationary time series, the cross-covariance and the cross-correlation as functions of time lag n serve to quantify the similarity of two time series. The latter measure is also used to assess whether the cross-correlations are statistically significant. For nonstationary time series, the analogous measures are detrended cross-correlations analysis (DCCA) and the recently proposed detrended cross-correlation coefficient, ρDCCA(T,n), where T is the total length of the time series and n the window size. For ρDCCA(T,n), we numerically calculated the Cauchy inequality -1≤ρDCCA(T,n)≤1. Here we derive -1≤ρDCCA(T,n)≤1 for a standard variance-covariance approach and for a detrending approach. For overlapping windows, we find the range of ρDCCA within which the cross-correlations become statistically significant. For overlapping windows we numerically determine—and for nonoverlapping windows we derive—that the standard deviation of ρDCCA(T,n) tends with increasing T to 1/T. Using ρDCCA(T,n) we show that the Chinese financial market's tendency to follow the U.S. market is extremely weak. We also propose an additional statistical test that can be used to quantify the existence of cross-correlations between two power-law correlated time series.

An automated Pearson's correlation change classification (APC3) approach for GC/MS metabonomic data using total ion chromatograms (TICs).

PubMed

Prakash, Bhaskaran David; Esuvaranathan, Kesavan; Ho, Paul C; Pasikanti, Kishore Kumar; Chan, Eric Chun Yong; Yap, Chun Wei

2013-05-21

A fully automated and computationally efficient Pearson's correlation change classification (APC3) approach is proposed and shown to have overall comparable performance with both an average accuracy and an average AUC of 0.89 ± 0.08 but is 3.9 to 7 times faster, easier to use and have low outlier susceptibility in contrast to other dimensional reduction and classification combinations using only the total ion chromatogram (TIC) intensities of GC/MS data. The use of only the TIC permits the possible application of APC3 to other metabonomic data such as LC/MS TICs or NMR spectra. A RapidMiner implementation is available for download at http://padel.nus.edu.sg/software/padelapc3.

Corneal endothelial dysfunction in Pearson syndrome.

PubMed

Kasbekar, Shivani A; Gonzalez-Martin, Jose A; Shafiq, Ayad E; Chandna, Arvind; Willoughby, Colin E

2013-01-01

Mitochondrial disorders are associated with well recognized ocular manifestations. Pearson syndrome is an often fatal, multisystem, mitochondrial disorder that causes variable bone marrow, hepatic, renal and pancreatic exocrine dysfunction. Phenotypic progression of ocular disease in a 12-year-old male with Pearson syndrome is described. This case illustrates phenotypic drift from Pearson syndrome to Kearns-Sayre syndrome given the patient's longevity. Persistent corneal endothelial failure was noted in addition to ptosis, chronic external ophthalmoplegia and mid-peripheral pigmentary retinopathy. We propose that corneal edema resulting from corneal endothelial metabolic pump failure occurs within a spectrum of mitochondrial disorders.

Evaluation of the Talar Cartilage in Chronic Lateral Ankle Instability with Lateral Ligament Injury Using Biochemical T2* Mapping: Correlation with Clinical Symptoms.

PubMed

Hu, Yiwen; Tao, Hongyue; Qiao, Yang; Ma, Kui; Hua, Yinghui; Yan, Xu; Chen, Shuang

2018-06-19

This study aims to quantitatively compare T2* measurements of the talar cartilage between chronic lateral ankle instability (LAI) patients with lateral ligament injury and healthy volunteers, and to assess the association of T2* value with American Orthopedic Foot and Ankle Society (AOFAS) score. Nineteen consecutive patients with chronic LAI (LAI group) and 19 healthy individuals (control group) were enrolled. Biochemical magnetic resonance examination of the ankle was performed in all participants using three-dimensional gradient-echo T2* mapping. Total talar cartilage was divided into six subcompartments, including medial anterior (MA), central medial, medial posterior, lateral anterior, central lateral (LC), and lateral posterior regions. T2* values of respective cartilage areas were measured and compared between the two groups using Student t test. AOFAS scoring was performed for clinical evaluation. Then, the association of T2* value with AOFAS score was evaluated by Pearson correlation. The T2* values of total talar cartilage, as well as MA and LC cartilage compartments, in the chronic LAI group were significantly higher than control values (P <.001, P = .039, and P = .014, respectively). Furthermore, the T2* value of MA in the chronic LAI group was negatively correlated with AOFAS score (r =-0.8089, P <.001). Chronic LAI with lateral ligament injury may have a causal connection with early cartilage degeneration in the ankle joint, especially in MA and LC cartilage compartments, as assessed by quantitative T2* measurements. The clinical score correlates highly with T2* value of the MA cartilage compartment, indicating that MA may be the principal cartilage area conferring clinical symptoms. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

T1ρ Dispersion in Articular Cartilage

PubMed Central

Besier, Thor F.; Pauly, John M.; Smith, R. Lane; Delp, Scott L.; Beaupre, Gary S.; Gold, Garry E.

2015-01-01

Objective This study assessed T1ρ relaxation dispersion, measured by magnetic resonance imaging (MRI), as a tool to noninvasively evaluate cartilage material and biochemical properties. The specific objective was to answer two questions: (1) does cartilage initial elastic modulus (E0) correlate with T1ρ dispersion effects and (2) does collagen or proteoglycan content correlate with T1ρ dispersion effects? Design Cadaveric patellae with and without visible cartilage damage on conventional MR were included. T2 and T1ρ relaxation times at 500 and 1000 Hz spin-lock field amplitudes were measured. We estimated T1ρ dispersion effects by measuring T1ρ relaxation time at 500 and 1000 Hz and T2 relaxation time and using a new tool, the ratio T1ρ/T2. Cartilage initial elastic modulus, E0, was measured from initial response of mechanical indentation creep tests. Collagen and proteoglycan contents were measured at the indentation test sites; proteoglycan content was measured by their covalently linked sulfated glycosaminoglycans (sGAG). Pearson correlation coefficients were determined, taking into account the clustering of multiple samples within a single patella specimen. Results Cartilage initial elastic modulus, E0, increased with decreasing values of T1ρ/T2 measurements at both 500 Hz (P = 0.034) and 1000 Hz (P = 0.022). 1/T1ρ relaxation time (500 Hz) increased with increasing sGAG content (P = 0.041). Conclusions T1ρ/T2 ratio, a new tool, and cartilage initial elastic modulus are both measures of water–protein interactions, are dependent on the cartilage structure, and were correlated in this study. PMID:26069714

Test Review: Wagner, R. K., Torgesen, J. K., Rashotte, C. A., & Pearson, N. A., "Comprehensive Test of Phonological Processing-2nd Ed. (CTOPP-2)." Austin, Texas: Pro-Ed

ERIC Educational Resources Information Center

Dickens, Rachel H.; Meisinger, Elizabeth B.; Tarar, Jessica M.

2015-01-01

The Comprehensive Test of Phonological Processing-Second Edition (CTOPP-2; Wagner, Torgesen, Rashotte, & Pearson, 2013) is a norm-referenced test that measures phonological processing skills related to reading for individuals aged 4 to 24. According to its authors, the CTOPP-2 may be used to identify individuals who are markedly below their…

An improved Pearson's correlation proximity-based hierarchical clustering for mining biological association between genes.

PubMed

Booma, P M; Prabhakaran, S; Dhanalakshmi, R

2014-01-01

Microarray gene expression datasets has concerned great awareness among molecular biologist, statisticians, and computer scientists. Data mining that extracts the hidden and usual information from datasets fails to identify the most significant biological associations between genes. A search made with heuristic for standard biological process measures only the gene expression level, threshold, and response time. Heuristic search identifies and mines the best biological solution, but the association process was not efficiently addressed. To monitor higher rate of expression levels between genes, a hierarchical clustering model was proposed, where the biological association between genes is measured simultaneously using proximity measure of improved Pearson's correlation (PCPHC). Additionally, the Seed Augment algorithm adopts average linkage methods on rows and columns in order to expand a seed PCPHC model into a maximal global PCPHC (GL-PCPHC) model and to identify association between the clusters. Moreover, a GL-PCPHC applies pattern growing method to mine the PCPHC patterns. Compared to existing gene expression analysis, the PCPHC model achieves better performance. Experimental evaluations are conducted for GL-PCPHC model with standard benchmark gene expression datasets extracted from UCI repository and GenBank database in terms of execution time, size of pattern, significance level, biological association efficiency, and pattern quality.

An Improved Pearson's Correlation Proximity-Based Hierarchical Clustering for Mining Biological Association between Genes

PubMed Central

Booma, P. M.; Prabhakaran, S.; Dhanalakshmi, R.

2014-01-01

Microarray gene expression datasets has concerned great awareness among molecular biologist, statisticians, and computer scientists. Data mining that extracts the hidden and usual information from datasets fails to identify the most significant biological associations between genes. A search made with heuristic for standard biological process measures only the gene expression level, threshold, and response time. Heuristic search identifies and mines the best biological solution, but the association process was not efficiently addressed. To monitor higher rate of expression levels between genes, a hierarchical clustering model was proposed, where the biological association between genes is measured simultaneously using proximity measure of improved Pearson's correlation (PCPHC). Additionally, the Seed Augment algorithm adopts average linkage methods on rows and columns in order to expand a seed PCPHC model into a maximal global PCPHC (GL-PCPHC) model and to identify association between the clusters. Moreover, a GL-PCPHC applies pattern growing method to mine the PCPHC patterns. Compared to existing gene expression analysis, the PCPHC model achieves better performance. Experimental evaluations are conducted for GL-PCPHC model with standard benchmark gene expression datasets extracted from UCI repository and GenBank database in terms of execution time, size of pattern, significance level, biological association efficiency, and pattern quality. PMID:25136661

Using type IV Pearson distribution to calculate the probabilities of underrun and overrun of lists of multiple cases.

PubMed

Wang, Jihan; Yang, Kai

2014-07-01

An efficient operating room needs both little underutilised and overutilised time to achieve optimal cost efficiency. The probabilities of underrun and overrun of lists of cases can be estimated by a well defined duration distribution of the lists. To propose a method of predicting the probabilities of underrun and overrun of lists of cases using Type IV Pearson distribution to support case scheduling. Six years of data were collected. The first 5 years of data were used to fit distributions and estimate parameters. The data from the last year were used as testing data to validate the proposed methods. The percentiles of the duration distribution of lists of cases were calculated by Type IV Pearson distribution and t-distribution. Monte Carlo simulation was conducted to verify the accuracy of percentiles defined by the proposed methods. Operating rooms in John D. Dingell VA Medical Center, United States, from January 2005 to December 2011. Differences between the proportion of lists of cases that were completed within the percentiles of the proposed duration distribution of the lists and the corresponding percentiles. Compared with the t-distribution, the proposed new distribution is 8.31% (0.38) more accurate on average and 14.16% (0.19) more accurate in calculating the probabilities at the 10th and 90th percentiles of the distribution, which is a major concern of operating room schedulers. The absolute deviations between the percentiles defined by Type IV Pearson distribution and those from Monte Carlo simulation varied from 0.20  min (0.01) to 0.43  min (0.03). Operating room schedulers can rely on the most recent 10 cases with the same combination of surgeon and procedure(s) for distribution parameter estimation to plan lists of cases. Values are mean (SEM). The proposed Type IV Pearson distribution is more accurate than t-distribution to estimate the probabilities of underrun and overrun of lists of cases. However, as not all the individual case durations

Significance Testing Needs a Taxonomy: Or How the Fisher, Neyman-Pearson Controversy Resulted in the Inferential Tail Wagging the Measurement Dog.

PubMed

Bradley, Michael T; Brand, Andrew

2016-10-01

Accurate measurement and a cutoff probability with inferential statistics are not wholly compatible. Fisher understood this when he developed the F test to deal with measurement variability and to make judgments on manipulations that may be worth further study. Neyman and Pearson focused on modeled distributions whose parameters were highly determined and concluded that inferential judgments following an F test could be made with accuracy because the distribution parameters were determined. Neyman and Pearson's approach in the application of statistical analyses using alpha and beta error rates has played a dominant role guiding inferential judgments, appropriately in highly determined situations and inappropriately in scientific exploration. Fisher tried to explain the different situations, but, in part due to some obscure wording, generated a long standing dispute that currently has left the importance of Fisher's p < .05 criteria not fully understood and a general endorsement of the Neyman and Pearson error rate approach. Problems were compounded with power calculations based on effect sizes following significant results entering into exploratory science. To understand in a practical sense when each approach should be used, a dimension reflecting varying levels of certainty or knowledge of population distributions is presented. The dimension provides a taxonomy of statistical situations and appropriate approaches by delineating four zones that represent how well the underlying population of interest is defined ranging from exploratory situations to highly determined populations. © The Author(s) 2016.

Remodeling Pearson's Correlation for Functional Brain Network Estimation and Autism Spectrum Disorder Identification

PubMed Central

Li, Weikai; Wang, Zhengxia; Zhang, Limei; Qiao, Lishan; Shen, Dinggang

2017-01-01

Functional brain network (FBN) has been becoming an increasingly important way to model the statistical dependence among neural time courses of brain, and provides effective imaging biomarkers for diagnosis of some neurological or psychological disorders. Currently, Pearson's Correlation (PC) is the simplest and most widely-used method in constructing FBNs. Despite its advantages in statistical meaning and calculated performance, the PC tends to result in a FBN with dense connections. Therefore, in practice, the PC-based FBN needs to be sparsified by removing weak (potential noisy) connections. However, such a scheme depends on a hard-threshold without enough flexibility. Different from this traditional strategy, in this paper, we propose a new approach for estimating FBNs by remodeling PC as an optimization problem, which provides a way to incorporate biological/physical priors into the FBNs. In particular, we introduce an L1-norm regularizer into the optimization model for obtaining a sparse solution. Compared with the hard-threshold scheme, the proposed framework gives an elegant mathematical formulation for sparsifying PC-based networks. More importantly, it provides a platform to encode other biological/physical priors into the PC-based FBNs. To further illustrate the flexibility of the proposed method, we extend the model to a weighted counterpart for learning both sparse and scale-free networks, and then conduct experiments to identify autism spectrum disorders (ASD) from normal controls (NC) based on the constructed FBNs. Consequently, we achieved an 81.52% classification accuracy which outperforms the baseline and state-of-the-art methods. PMID:28912708

Remodeling Pearson's Correlation for Functional Brain Network Estimation and Autism Spectrum Disorder Identification.

PubMed

Li, Weikai; Wang, Zhengxia; Zhang, Limei; Qiao, Lishan; Shen, Dinggang

2017-01-01

Functional brain network (FBN) has been becoming an increasingly important way to model the statistical dependence among neural time courses of brain, and provides effective imaging biomarkers for diagnosis of some neurological or psychological disorders. Currently, Pearson's Correlation (PC) is the simplest and most widely-used method in constructing FBNs. Despite its advantages in statistical meaning and calculated performance, the PC tends to result in a FBN with dense connections. Therefore, in practice, the PC-based FBN needs to be sparsified by removing weak (potential noisy) connections. However, such a scheme depends on a hard-threshold without enough flexibility. Different from this traditional strategy, in this paper, we propose a new approach for estimating FBNs by remodeling PC as an optimization problem, which provides a way to incorporate biological/physical priors into the FBNs. In particular, we introduce an L 1 -norm regularizer into the optimization model for obtaining a sparse solution. Compared with the hard-threshold scheme, the proposed framework gives an elegant mathematical formulation for sparsifying PC-based networks. More importantly, it provides a platform to encode other biological/physical priors into the PC-based FBNs. To further illustrate the flexibility of the proposed method, we extend the model to a weighted counterpart for learning both sparse and scale-free networks, and then conduct experiments to identify autism spectrum disorders (ASD) from normal controls (NC) based on the constructed FBNs. Consequently, we achieved an 81.52% classification accuracy which outperforms the baseline and state-of-the-art methods.

Heavy-tailed fractional Pearson diffusions.

PubMed

Leonenko, N N; Papić, I; Sikorskii, A; Šuvak, N

2017-11-01

We define heavy-tailed fractional reciprocal gamma and Fisher-Snedecor diffusions by a non-Markovian time change in the corresponding Pearson diffusions. Pearson diffusions are governed by the backward Kolmogorov equations with space-varying polynomial coefficients and are widely used in applications. The corresponding fractional reciprocal gamma and Fisher-Snedecor diffusions are governed by the fractional backward Kolmogorov equations and have heavy-tailed marginal distributions in the steady state. We derive the explicit expressions for the transition densities of the fractional reciprocal gamma and Fisher-Snedecor diffusions and strong solutions of the associated Cauchy problems for the fractional backward Kolmogorov equation.

R1 changes in the human placenta at 3 T in response to a maternal oxygen challenge protocol.

PubMed

Ingram, Emma; Hawkins, Lauren; Morris, David M; Myers, Jenny; Sibley, Colin P; Johnstone, Edward D; Naish, Josephine H

2016-03-01

Oxygen-enhanced MRI non-invasively monitors placental oxygenation in-vivo. This technique has been demonstrated at 1.5 Tesla (T) in healthy pregnancies. The aim of this study was to investigate whether findings are comparable at 3T. Nine pregnant volunteers underwent MRI at 3T. Scans obtained R1 (1/T1) measures from T1 maps under air, followed by a dynamic series breathing 100% oxygen. A statistically significant negative correlation was found between dR1 and gestation (P = 0.0008, r = -0.90, Pearson correlation test). The effect of the field strength was not significant within regression analysis. Placental Oxygen-Enhanced MRI at 3T gives comparable results to those previously obtained at 1.5T. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Maximum Entropy Test for Evaluating Higher-Order Correlations in Spike Counts

PubMed Central

Onken, Arno; Dragoi, Valentin; Obermayer, Klaus

2012-01-01

Evaluating the importance of higher-order correlations of neural spike counts has been notoriously hard. A large number of samples are typically required in order to estimate higher-order correlations and resulting information theoretic quantities. In typical electrophysiology data sets with many experimental conditions, however, the number of samples in each condition is rather small. Here we describe a method that allows to quantify evidence for higher-order correlations in exactly these cases. We construct a family of reference distributions: maximum entropy distributions, which are constrained only by marginals and by linear correlations as quantified by the Pearson correlation coefficient. We devise a Monte Carlo goodness-of-fit test, which tests - for a given divergence measure of interest - whether the experimental data lead to the rejection of the null hypothesis that it was generated by one of the reference distributions. Applying our test to artificial data shows that the effects of higher-order correlations on these divergence measures can be detected even when the number of samples is small. Subsequently, we apply our method to spike count data which were recorded with multielectrode arrays from the primary visual cortex of anesthetized cat during an adaptation experiment. Using mutual information as a divergence measure we find that there are spike count bin sizes at which the maximum entropy hypothesis can be rejected for a substantial number of neuronal pairs. These results demonstrate that higher-order correlations can matter when estimating information theoretic quantities in V1. They also show that our test is able to detect their presence in typical in-vivo data sets, where the number of samples is too small to estimate higher-order correlations directly. PMID:22685392

Correlation Coefficients: Appropriate Use and Interpretation.

PubMed

Schober, Patrick; Boer, Christa; Schwarte, Lothar A

2018-05-01

Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. The Pearson correlation coefficient is typically used for jointly normally distributed data (data that follow a bivariate normal distribution). For nonnormally distributed continuous data, for ordinal data, or for data with relevant outliers, a Spearman rank correlation can be used as a measure of a monotonic association. Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.

Reconstructing gene regulatory networks from knock-out data using Gaussian Noise Model and Pearson Correlation Coefficient.

PubMed

Mohamed Salleh, Faridah Hani; Arif, Shereena Mohd; Zainudin, Suhaila; Firdaus-Raih, Mohd

2015-12-01

A gene regulatory network (GRN) is a large and complex network consisting of interacting elements that, over time, affect each other's state. The dynamics of complex gene regulatory processes are difficult to understand using intuitive approaches alone. To overcome this problem, we propose an algorithm for inferring the regulatory interactions from knock-out data using a Gaussian model combines with Pearson Correlation Coefficient (PCC). There are several problems relating to GRN construction that have been outlined in this paper. We demonstrated the ability of our proposed method to (1) predict the presence of regulatory interactions between genes, (2) their directionality and (3) their states (activation or suppression). The algorithm was applied to network sizes of 10 and 50 genes from DREAM3 datasets and network sizes of 10 from DREAM4 datasets. The predicted networks were evaluated based on AUROC and AUPR. We discovered that high false positive values were generated by our GRN prediction methods because the indirect regulations have been wrongly predicted as true relationships. We achieved satisfactory results as the majority of sub-networks achieved AUROC values above 0.5. Copyright © 2015 Elsevier Ltd. All rights reserved.

Top quark polarization and T-odd spin correlations as tools for testing (non) Standard Model predictions

NASA Astrophysics Data System (ADS)

Bernreuther, W.; Ma, J. P.; Schroeder, T.

In this paper a number of T-odd spin-momentum correlations are defined for t and t-bar quarks and directly measurable correlations involving the momenta of the charged leptons and/or b jets from t and t-bar decay are identified. It concentrates on observables which can be classified as being even under a CP symmetry transformation in the case of e(sup +)e(sup -) yields tt-bar X or pp-bar yields tt-bar X (unpolarized or transversely polarized beams). These correlations project onto absorptive parts of the scattering matrix which are induced by CP-conserving interactions. In order to estimate the effects of the Standard Model interactions the Quantum Chromodynamics and Higgs boson contributions were calculated to a number of these observables. Several of them are considered to be useful tools for a detailed study of the tt-bar system at future hadron colliders.

Correlational Analysis of Ordinal Data: From Pearson's "r" to Bayesian Polychoric Correlation

ERIC Educational Resources Information Center

Choi, Jaehwa; Peters, Michelle; Mueller, Ralph O.

2010-01-01

Correlational analyses are one of the most popular quantitative methods, yet also one of the mostly frequently misused methods in social and behavioral research, especially when analyzing ordinal data from Likert or other rating scales. Although several correlational analysis options have been developed for ordinal data, there seems to be a lack…

A novel fractal image compression scheme with block classification and sorting based on Pearson's correlation coefficient.

PubMed

Wang, Jianji; Zheng, Nanning

2013-09-01

Fractal image compression (FIC) is an image coding technology based on the local similarity of image structure. It is widely used in many fields such as image retrieval, image denoising, image authentication, and encryption. FIC, however, suffers from the high computational complexity in encoding. Although many schemes are published to speed up encoding, they do not easily satisfy the encoding time or the reconstructed image quality requirements. In this paper, a new FIC scheme is proposed based on the fact that the affine similarity between two blocks in FIC is equivalent to the absolute value of Pearson's correlation coefficient (APCC) between them. First, all blocks in the range and domain pools are chosen and classified using an APCC-based block classification method to increase the matching probability. Second, by sorting the domain blocks with respect to APCCs between these domain blocks and a preset block in each class, the matching domain block for a range block can be searched in the selected domain set in which these APCCs are closer to APCC between the range block and the preset block. Experimental results show that the proposed scheme can significantly speed up the encoding process in FIC while preserving the reconstructed image quality well.

The human foramen magnum--normal anatomy of the cisterna magna in adults.

PubMed

Whitney, Nathaniel; Sun, Hai; Pollock, Jeffrey M; Ross, Donald A

2013-11-01

The goal of this study was to radiologically describe the anatomical characteristics of the cisterna magna (CM) with regard to presence, dimension, and configuration. In this retrospective study, 523 records were reviewed. We defined five CM types, the range of which covered all normal variants found in the study population. Characteristics of the CM were recorded and correlations between various posterior fossa dimensions and CM volume determined. There were 268 female (mean age 50.9 ± 16.9 years) and 255 male (mean age 54.1 ± 15.8 years) patients. CM volume was smaller in females than in males and correlated with age (Pearson correlation, r = 0.1494, p = 0.0006) and gender (unpaired t test, r (2) = 0.0608, p < 0.0001). Clivus length correlated with CM volume (Pearson correlation, r = 0.211, p < 0.0001) and gender (unpaired t test, r (2) = 0.2428, p < 0.0001). Tentorial angle did not correlate with CM volume (Pearson correlation, r = -0.0609, p < 0.1642) but did correlate with gender (unpaired t test, r (2) = 0.0163, p < 0.0035). The anterior-posterior dimension of cerebrospinal fluid anterior to the brainstem correlated with CM volume (Pearson correlation, r = 0.181, p < 0.0001) and gender (unpaired t test, r (2) = 0.0205, p = 0.001). The anatomical description and simple classification system we define allows for a more precise description of posterior fossa anatomy and could potentially contribute to the understanding of Chiari malformation anatomy and management.

Pearson syndrome in a Diamond-Blackfan anemia cohort.

PubMed

Alter, Blanche P

2014-07-17

In this issue of Blood, Gagne et al describe a cohort of 362 patients clinically classified as having Diamond-Blackfan anemia (DBA), in which 175 (48%) were found to have mutations and deletions in ribosomal protein genes or GATA1, and 8 of the remaining patients (2.2% overall) had mitochondrial gene deletions consistent with Pearson marrow-pancreas syndrome (PS). The authors propose that all patients with presumptive DBA should be tested for mitochondrial DNA (mtDNA) deletion during their initial genetic evaluation.

Correlation of cardiorespiratory fitness with risk factors for cardiovascular disease in children with type 1 diabetes mellitus.

PubMed

Miculis, Cristiane P; de Campos, Wagner; Gasparotto, Guilherme S; Silva, Michael P; Mascarenhas, Luis P; Boguszewski, Margaret C S

2012-01-01

The objective of this study was to correlate CRF with cardiovascular risk factors in T1DM children. Fifty children and adolescents aged between 9 and 17 years with no diabetes complications and a mean diabetes duration of 4.6 years were selected. Antropometric, sexual maturation and blood pressure data were evaluated. CRF level was assessed with a 20-m shuttle run test. Laboratory tests were performed to verify fasting lipids and glycated hemoglobin. Statistical analyses were made with Pearson partial correlation, t test, and one-way ANOVA, with p≤0.05. After adjustment for body adiposity and sexual maturity, inverse correlations among CRF and TC, TG, TC/HDL-C, TG/HDL-C, non-HDL-C, and SBP were statistically significant. Variables differing by sex included weight Z score, BMI Z score, skinfold thickness, percentage of body fat, and DBP. Boys had higher CRF compared to girls. CRF and TC differed significantly by sexual maturation status. An inverse and significant relationship between CRF and most lipid profile's components and SBP in poor controlled T1DM children and adolescents was found, independently of body adiposity. Copyright © 2012 Elsevier Inc. All rights reserved.

Karl Pearson and eugenics: personal opinions and scientific rigor.

PubMed

Delzell, Darcie A P; Poliak, Cathy D

2013-09-01

The influence of personal opinions and biases on scientific conclusions is a threat to the advancement of knowledge. Expertise and experience does not render one immune to this temptation. In this work, one of the founding fathers of statistics, Karl Pearson, is used as an illustration of how even the most talented among us can produce misleading results when inferences are made without caution or reference to potential bias and other analysis limitations. A study performed by Pearson on British Jewish schoolchildren is examined in light of ethical and professional statistical practice. The methodology used and inferences made by Pearson and his coauthor are sometimes questionable and offer insight into how Pearson's support of eugenics and his own British nationalism could have potentially influenced his often careless and far-fetched inferences. A short background into Pearson's work and beliefs is provided, along with an in-depth examination of the authors' overall experimental design and statistical practices. In addition, portions of the study regarding intelligence and tuberculosis are discussed in more detail, along with historical reactions to their work.

Relationship between career motivation and perceived spiritual leadership in health professional educators: a correlational study in Iran.

PubMed

Sadeghifar, Jamil; Bahadori, Mohammadkarim; Baldacchino, Donia; Raadabadi, Mehdi; Jafari, Mehdi

2013-12-20

Career motivation in university educators through efficient ways and appropriate with the educational system, is considered one of the important factors affecting education of students and their competence. This study aimed to determine the relationship between career motivation and spiritual leadership among a university of medical sciences in the west, Iran. This descriptive, cross-sectional correlation study was conducted among the university educators of medical sciences in the west, Iran in 2012. All of the educators (N=230) were selected and recruited according to census method. The data were collected by two established self-completed questionnaires on spiritual leadership (SL) and career motivation. Data were analyzed statistically by parametric tests: Pearson correlation, independent student t-test and one-way analysis of variance (ANOVA). The Pearson correlation test identified a significant relationship between educators' career motivation and vision, altruistic love, hope/faith, meaning/calling and membership dimensions of spiritual leadership (p<0.05). The independent t-test detected a significant relationship between the 'hope/faith' (p=0.04) and organizational commitment (p=0.004) dimensions and the gender of educators. ANOVA revealed significant differences in educators' years of work experience and their overall career motivation (p=0.003) and the dimension of 'membership' (p<0.04). A significant relationship was found in 'altruistic love' and 'Hope/faith', and the educators' academic rank place in the university (p=0.03). Also a significant relationship was found in 'vision' (p=0.03) and 'altruistic love' (p=0.002) and 'membership' (p=0.04) dimensions, and the type of faculty. The results indicate that the dimensions of existence of spiritual leadership may have a positive relationship with educators' career motivation.

Estimating correlation of prevalence at two locations in the farm-to-table continuum using qualitative test data.

PubMed

Williams, Michael S; Ebel, Eric D

2017-03-20

The presence or absence of contaminants in food samples changes as a commodity moves along the farm-to-table continuum. Interest lies in the degree to which the prevalence (i.e., infected animals or contaminated sample units) at one location in the continuum, as measured by the proportion of test-positive samples, is correlated with the prevalence at a location later in the continuum. If prevalence of a contaminant at one location in the continuum is strongly correlated with the prevalence of the contaminant later in the continuum, then the effect of changes in contamination on overall food safety can be better understood. Pearson's correlation coefficient is one of the simplest metrics of association between two measurements of prevalence but it is biased when data consisting of presence/absence testing results are used to directly estimate the correlation. This study demonstrates the potential magnitude of this bias and explores the utility of three methods for unbiased estimation of the degree of correlation in prevalence. An example, based on testing broiler chicken carcasses for Salmonella at re-hang and post-chill, is used to demonstrate the methods. Published by Elsevier B.V.

MaxEnt alternatives to pearson family distributions

NASA Astrophysics Data System (ADS)

Stokes, Barrie J.

2012-05-01

In a previous MaxEnt conference [11] a method of obtaining MaxEnt univariate distributions under a variety of constraints was presented. The Mathematica function Interpolation[], normally used with numerical data, can also process "semi-symbolic" data, and Lagrange Multiplier equations were solved for a set of symbolic ordinates describing the required MaxEnt probability density function. We apply a more developed version of this approach to finding MaxEnt distributions having prescribed β1 and β2 values, and compare the entropy of the MaxEnt distribution to that of the Pearson family distribution having the same β1 and β2. These MaxEnt distributions do have, in general, greater entropy than the related Pearson distribution. In accordance with Jaynes' Maximum Entropy Principle, these MaxEnt distributions are thus to be preferred to the corresponding Pearson distributions as priors in Bayes' Theorem.

Simultaneous acquisition for T2 -T2 Exchange and T1 -T2 correlation NMR experiments

NASA Astrophysics Data System (ADS)

Montrazi, Elton T.; Lucas-Oliveira, Everton; Araujo-Ferreira, Arthur G.; Barsi-Andreeta, Mariane; Bonagamba, Tito J.

2018-04-01

The NMR measurements of longitudinal and transverse relaxation times and its multidimensional correlations provide useful information about molecular dynamics. However, these experiments are very time-consuming, and many researchers proposed faster experiments to reduce this issue. This paper presents a new way to simultaneously perform T2 -T2 Exchange and T1 -T2 correlation experiments by taking the advantage of the storage time and the two steps phase cycling used for running the relaxation exchange experiment. The data corresponding to each step is either summed or subtracted to produce the T2 -T2 and T1 -T2 data, enhancing the information obtained while maintaining the experiment duration. Comparing the results from this technique with traditional NMR experiments it was possible to validate the method.

The Use of Time Series Analysis and t Tests with Serially Correlated Data Tests.

ERIC Educational Resources Information Center

Nicolich, Mark J.; Weinstein, Carol S.

1981-01-01

Results of three methods of analysis applied to simulated autocorrelated data sets with an intervention point (varying in autocorrelation degree, variance of error term, and magnitude of intervention effect) are compared and presented. The three methods are: t tests; maximum likelihood Box-Jenkins (ARIMA); and Bayesian Box Jenkins. (Author/AEF)

Partial Roc Reveals Superiority of Mutual Rank of Pearson's Correlation Coefficient as a Coexpression Measure to Elucidate Functional Association of Genes

NASA Astrophysics Data System (ADS)

Obayashi, Takeshi; Kinoshita, Kengo

2013-01-01

Gene coexpression analysis is a powerful approach to elucidate gene function. We have established and developed this approach using vast amount of publicly available gene expression data measured by microarray techniques. The coexpressed genes are used to estimate gene function of the guide gene or to construct gene coexpression networks. In the case to construct gene networks, researchers should introduce an arbitrary threshold of gene coexpression, because gene coexpression value is continuous value. In the viewpoint to introduce common threshold of gene coexpression, we previously reported rank of Pearson's correlation coefficient (PCC) is more useful than the original PCC value. In this manuscript, we re-assessed the measure of gene coexpression to construct gene coexpression network, and found that mutual rank (MR) of PCC showed better performance than rank of PCC and the original PCC in low false positive rate.

Inverse correlation between quasiparticle mass and T c in a cuprate high-T c superconductor.

PubMed

Putzke, Carsten; Malone, Liam; Badoux, Sven; Vignolle, Baptiste; Vignolles, David; Tabis, Wojciech; Walmsley, Philip; Bird, Matthew; Hussey, Nigel E; Proust, Cyril; Carrington, Antony

2016-03-01

Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature T c is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-T c superconductivity. We have tested the robustness of this correlation between m* and T c by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as T c increases under pressure. This inverse correlation between m* and T c suggests that quantum fluctuations of the charge order enhance m* but do not enhance T c.

Contextualisation in the revised dual representation theory of PTSD: a response to Pearson and colleagues.

PubMed

Brewin, Chris R; Burgess, Neil

2014-03-01

Three recent studies (Pearson, 2012; Pearson, Ross, & Webster, 2012) purported to test the revised dual representation theory of posttraumatic stress disorder (Brewin, Gregory, Lipton, & Burgess, 2010) by manipulating the amount of additional information accompanying traumatic stimulus materials and assessing the effect on subsequent intrusive memories. Here we point out that these studies involve a misunderstanding of the meaning of "contextual" within the theory, such that the manipulation would be unlikely to have had the intended effect and the results are ambiguous with respect to the theory. Past and future experimental tests of the theory are discussed. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Increased correlation coefficient between the written test score and tutors' performance test scores after training of tutors for assessment of medical students during problem-based learning course in Malaysia.

PubMed

Jaiprakash, Heethal; Min, Aung Ko Ko; Ghosh, Sarmishtha

2016-03-01

This paper is aimed at finding if there was a change of correlation between the written test score and tutors' performance test scores in the assessment of medical students during a problem-based learning (PBL) course in Malaysia. This is a cross-sectional observational study, conducted among 264 medical students in two groups from November 2010 to November 2012. The first group's tutors did not receive tutor training; while the second group's tutors were trained in the PBL process. Each group was divided into high, middle and low achievers based on their end-of-semester exam scores. PBL scores were taken which included written test scores and tutors' performance test scores. Pearson correlation coefficient was calculated between the two kinds of scores in each group. The correlation coefficient between the written scores and tutors' scores in group 1 was 0.099 (p<0.001) and for group 2 was 0.305 (p<0.001). The higher correlation coefficient in the group where tutors received the PBL training reinforces the importance of tutor training before their participation in the PBL course.

Finite-T correlations and free exchange-correlation energy of quasi-one-dimensional electron gas

NASA Astrophysics Data System (ADS)

Garg, Vinayak; Sharma, Akariti; Moudgil, R. K.

2018-02-01

We have studied the effect of temperature on static density-density correlations and plasmon excitation spectrum of quasi-one-dimensional electron gas (Q1DEG) using the random phase approximation (RPA). Numerical results for static structure factor, pair-correlation function, static density susceptibility, free exchange-correlation energy and plasmon dispersion are presented over a wide range of temperature and electron density. As an interesting result, we find that the short-range correlations exhibit a non-monotonic dependence on temperature T, initially growing stronger (i.e. the pair-correlation function at small inter-electron spacing assuming relatively smaller values) with increasing T and then weakening above a critical T. The cross-over temperature is found to increase with increasing coupling among electrons. Also, the q = 2kF peak in the static density susceptibility χ(q,ω = 0,T) at T = 0 K smears out with rising T. The free exchange-correlation energy and plasmon dispersion show a significant variation with T, and the trend is qualitatively the same as in higher dimensions.

Bi-exponential T2 analysis of healthy and diseased Achilles tendons: an in vivo preliminary magnetic resonance study and correlation with clinical score.

PubMed

Juras, Vladimir; Apprich, Sebastian; Szomolanyi, Pavol; Bieri, Oliver; Deligianni, Xeni; Trattnig, Siegfried

2013-10-01

To compare mono- and bi-exponential T2 analysis in healthy and degenerated Achilles tendons using a recently introduced magnetic resonance variable-echo-time sequence (vTE) for T2 mapping. Ten volunteers and ten patients were included in the study. A variable-echo-time sequence was used with 20 echo times. Images were post-processed with both techniques, mono- and bi-exponential [T2 m, short T2 component (T2 s) and long T2 component (T2 l)]. The number of mono- and bi-exponentially decaying pixels in each region of interest was expressed as a ratio (B/M). Patients were clinically assessed with the Achilles Tendon Rupture Score (ATRS), and these values were correlated with the T2 values. The means for both T2 m and T2 s were statistically significantly different between patients and volunteers; however, for T2 s, the P value was lower. In patients, the Pearson correlation coefficient between ATRS and T2 s was -0.816 (P = 0.007). The proposed variable-echo-time sequence can be successfully used as an alternative method to UTE sequences with some added benefits, such as a short imaging time along with relatively high resolution and minimised blurring artefacts, and minimised susceptibility artefacts and chemical shift artefacts. Bi-exponential T2 calculation is superior to mono-exponential in terms of statistical significance for the diagnosis of Achilles tendinopathy. • Magnetic resonance imaging offers new insight into healthy and diseased Achilles tendons • Bi-exponential T2 calculation in Achilles tendons is more beneficial than mono-exponential • A short T2 component correlates strongly with clinical score • Variable echo time sequences successfully used instead of ultrashort echo time sequences.

Relationship between Career Motivation and Perceived Spiritual Leadership in Health Professional Educators: A Correlational Study in Iran

PubMed Central

Sadeghifar, Jamil; Bahadori, Mohammadkarim; Baldacchino, Donia; Raadabadi, Mehdi; Jafari, Mehdi

2014-01-01

Background and Aims: Career motivation in university educators through efficient ways and appropriate with the educational system, is considered one of the important factors affecting education of students and their competence. This study aimed to determine the relationship between career motivation and spiritual leadership among a university of medical sciences in the west, Iran. Methods: This descriptive, cross-sectional correlation study was conducted among the university educators of medical sciences in the west, Iran in 2012. All of the educators (N=230) were selected and recruited according to census method. The data were collected by two established self-completed questionnaires on spiritual leadership (SL) and career motivation. Data were analyzed statistically by parametric tests: Pearson correlation, independent student t-test and one-way analysis of variance (ANOVA). Results: The Pearson correlation test identified a significant relationship between educators’ career motivation and vision, altruistic love, hope/faith, meaning/calling and membership dimensions of spiritual leadership (p<0.05). The independent t-test detected a significant relationship between the ‘hope/faith’ (p=0.04) and organizational commitment (p=0.004) dimensions and the gender of educators. ANOVA revealed significant differences in educators’ years of work experience and their overall career motivation (p=0.003) and the dimension of ‘membership’ (p<0.04). A significant relationship was found in ‘altruistic love’ and ‘Hope/faith’, and the educators’ academic rank place in the university (p=0.03). Also a significant relationship was found in ‘vision’ (p=0.03) and ‘altruistic love’ (p=0.002) and ‘membership’ (p=0.04) dimensions, and the type of faculty. Conclusion: The results indicate that the dimensions of existence of spiritual leadership may have a positive relationship with educators’ career motivation. PMID:24576374

Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients.

PubMed

Castro-Sesquen, Yagahira E; Gilman, Robert H; Mejia, Carolina; Clark, Daniel E; Choi, Jeong; Reimer-McAtee, Melissa J; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

2016-02-01

Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients.

The correlation of symptoms, pulmonary function tests and exercise testing with high-resolution computed tomography in patients with idiopathic interstitial pneumonia in a tertiary care hospital in South India.

PubMed

Isaac, Barney Thomas Jesudason; Thangakunam, Balamugesh; Cherian, Rekha A; Christopher, Devasahayam Jesudas

2015-01-01

For the follow-up of patients with idiopathic interstitial pneumonias (IIP), it is unclear which parameters of pulmonary function tests (PFT) and exercise testing would correlate best with high-resolution computed tomography (HRCT).. To find out the correlation of symptom scores, PFTs and exercise testing with HRCT scoring in patients diagnosed as idiopathic interstitial pneumonia. Cross-sectional study done in pulmonary medicine outpatients department of a tertiary care hospital in South India. Consecutive patients who were diagnosed as IIP by a standard algorithm were included into the study. Cough and dyspnea were graded for severity and duration. Pulmonary function tests and exercise testing parameters were noted. HRCT was scored based on an alveolar score, an interstitial score and a total score. The HRCT was correlated with each of the clinical and physiologic parameters. Pearson's/Spearman's correlation coefficient was used for the correlation of symptoms and parameters of ABG, PFT and 6MWT with the HRCT scores. A total of 94 patients were included in the study. Cough and dyspnea severity (r = 0.336 and 0.299), FVC (r = -0.48), TLC (r = -0.439) and DLCO and distance saturation product (DSP) (r = -0.368) and lowest saturation (r = -0.324) had significant correlation with total HRCT score. Among these, DLCO, particularly DLCO corrected % of predicted, correlated best with HRCT score (r = -0.721).. Symptoms, PFT and exercise testing had good correlation with HRCT. DLCO corrected % of predicted correlated best with HRCT.

Utilization of standardized patients to evaluate clinical and interpersonal skills of surgical residents.

PubMed

Hassett, James M; Zinnerstrom, Karen; Nawotniak, Ruth H; Schimpfhauser, Frank; Dayton, Merril T

2006-10-01

This project was designed to determine the growth of interpersonal skills during the first year of a surgical residency. All categorical surgical residents were given a clinical skills examination of abdominal pain using standardized patients during their orientation (T1). The categorical residents were retested after 11 months (T2). The assessment tool was based on a 12-item modified version of the 5-point Likert Interpersonal Scale (IP) used on the National Board of Medical Examiners prototype Clinical Skills Examination and a 24-item, done-or-not-done, history-taking checklist. Residents' self-evaluation scores were compared to standardized patients' assessment scores. Data were analyzed using the Pearson correlation coefficient, Wilcoxon signed rank test, Student t test, and Cronbach alpha. Thirty-eight categorical residents were evaluated at T1 and T2. At T1, in the history-taking exercise, the scores of the standardized patients and residents correlated (Pearson = .541, P = .000). In the interpersonal skills exercise, the scores of the standardized patients and residents did not correlate (Pearson = -0.238, P = .150). At T2, there was a significant improvement in the residents' self-evaluation scores in both the history-taking exercise (t = -3.280, P = .002) and the interpersonal skills exercise (t = 2.506, P = 0.017). In the history-taking exercise, the standardized patients' assessment scores correlated with the residents' self-evaluation scores (Pearson = 0.561, P = .000). In the interpersonal skills exercise, the standardized patients' assessment scores did not correlate with the residents' self-evaluation scores (Pearson = 0.078, P = .646). Surgical residents demonstrate a consistently low level of self-awareness regarding their interpersonal skills. Observed improvement in resident self-evaluation may be a function of growth in self-confidence.

Effective record length for the T-year event

USGS Publications Warehouse

Tasker, Gary D.

1983-01-01

The effect of serial dependence on the reliability of an estimate of the T-yr. event is of importance in hydrology because design decisions are based upon the estimate. In this paper the reliability of estimates of the T-yr. event from two common distributions is given as a function of number of observations and lag-one serial correlation coefficient for T = 2, 10, 20, 50, and 100 yr. A lag-one autoregressive model is assumed with either a normal or Pearson Type-III disturbance term. Results indicate that, if observations are serially correlated, the effective record length should be used to estimate the discharge associated with the expected exceedance probability. ?? 1983.

Pearson syndrome.

PubMed

Farruggia, Piero; Di Marco, Floriana; Dufour, Carlo

2018-03-01

Pearson syndrome (PS) is a sporadic and very rare syndrome classically associated with single large-scale deletions of mitochondrial DNA and characterized by refractory sideroblastic anemia during infancy. Areas covered: This review presents an analysis and interpretation of the published data that forms the basis for our understanding of PS. PubMed, Google Scholarand Thompson ISI Web of Knowledge were searched for relevant data. Expert commentary: PS is a very rare mitochodrial disease that involves different organs and systems. Clinical phenotype is extremely variable and may change over the course of disease itself with the possibility both of worsenings and improvements. Outcome is invariably lethal and at the moment no cure is available. Accurate supportive treatment and follow up program in centres with experience in mitochondrial diseases and marrow failure may positively influence quality and duration of life.

The Pearson-Readhead AGN Survey

NASA Astrophysics Data System (ADS)

Lister, M. L.

2009-08-01

The Pearson-Readhead survey of active galactic nuclei (AGN) was the first complete sample to be studied by VLBI, and was the subject of a detailed investigation by the VSOP program. We discuss the scientific findings from this unique survey, and how it has provided robust confirmation of the relativistic beaming model for AGN jets.

Subclinical respiratory dysfunction in chronic cervical cord compression: a pulmonary function test correlation.

PubMed

Bhagavatula, Indira Devi; Bhat, Dhananjaya I; Sasidharan, Gopalakrishnan M; Mishra, Rakesh Kumar; Maste, Praful Suresh; Vilanilam, George C; Sathyaprabha, Talakkad N

2016-06-01

OBJECTIVE Respiratory abnormalities are well documented in acute spinal cord injury; however, the literature available for respiratory dysfunction in chronic compressive myelopathy (CCM) is limited. Respiratory dysfunction in CCM is often subtle and subclinical. The authors studied the pattern of respiratory dysfunction in patients with chronic cord compression by using spirometry, and the clinical and surgical implications of this dysfunction. In this study they also attempted to address the postoperative respiratory function in these patients. METHODS A prospective study was done in 30 patients in whom cervical CCM due to either cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL) was diagnosed. Thirty age-matched healthy volunteers were recruited as controls. None of the patients included in the study had any symptoms or signs of respiratory dysfunction. After clinical and radiological diagnosis, all patients underwent pulmonary function tests (PFTs) performed using a standardized Spirometry Kit Micro before and after surgery. The data were analyzed using Statistical Software SPSS version 13.0. Comparison between the 2 groups was done using the Student t-test. The Pearson correlation coefficient was used for PFT results and Nurick classification scores. A p value < 0.05 was considered significant. RESULTS Cervical spondylotic myelopathy (prolapsed intervertebral disc) was the predominant cause of compression (n = 21, 70%) followed by OPLL (n = 9, 30%). The average patient age was 45.06 years. Degenerative cervical spine disease has a relatively younger onset in the Indian population. The majority of the patients (n = 28, 93.3%) had compression at or above the C-5 level. Ten patients (33.3%) underwent an anterior approach and discectomy, 11 patients (36.7%) underwent decompressive laminectomy, and the remaining 9 underwent either corpectomy with fusion or laminoplasty. The mean preoperative forced vital capacity (FVC) (65%) of the

"It was a young man's life": G. A. Pearson

Treesearch

Susan D. Olberding

2008-01-01

The nation's initial USFS research site commenced in a rustic cabin in the midst of northern Arizona's expansive ponderosa pine forest. Gustaf A. Pearson was the first in a distinguished line of USFS scientists to live and study there. A visitor to Fort Valley today often wishes he could have stood in Pearson's large boots (he was said to have enormous...

Correlation study between facet joint cartilage and intervertebral discs in early lumbar vertebral degeneration using T2, T2* and T1ρ mapping

PubMed Central

Zhang, Yi; Hu, Jianzhong; Duan, Chunyue; Hu, Ping; Lu, Hongbin; Peng, Xianjing

2017-01-01

Recent advancements in magnetic resonance imaging have allowed for the early detection of biochemical changes in intervertebral discs and articular cartilage. Here, we assessed the feasibility of axial T2, T2* and T1ρ mapping of the lumbar facet joints (LFJs) to determine correlations between cartilage and intervertebral discs (IVDs) in early lumbar vertebral degeneration. We recruited 22 volunteers and examined 202 LFJs and 101 IVDs with morphological (sagittal and axial FSE T2-weighted imaging) and axial biochemical (T2, T2* and T1ρ mapping) sequences using a 3.0T MRI scanner. IVDs were graded using the Pfirrmann system. Mapping values of LFJs were recorded according to the degeneration grades of IVDs at the same level. The feasibility of T2, T2* and T1ρ in IVDs and LFJs were analyzed by comparing these mapping values across subjects with different rates of degeneration using Kruskal-Wallis tests. A Pearson’s correlation analysis was used to compare T2, T2* and T1ρ values of discs and LFJs. We found excellent reproducibility in the T2, T2* and T1ρ values for the nucleus pulposus (NP), anterior and posterior annulus fibrosus (PAF), and LFJ cartilage (intraclass correlation coefficients 0.806–0.955). T2, T2* and T1ρ mapping (all P<0.01) had good Pfirrmann grade performances in the NP with IVD degeneration. LFJ T2* values were significantly different between grades I and IV (PL = 0.032, PR = 0.026), as were T1ρ values between grades II and III (PL = 0.002, PR = 0.006) and grades III and IV (PL = 0.006, PR = 0.001). Correlations were moderately negative for T1ρ values between LFJ cartilage and NP (rL = −0.574, rR = −0.551), and between LFJ cartilage and PAF (rL = −0.551, rR = −0.499). T1ρ values of LFJ cartilage was weakly correlated with T2 (r = 0.007) and T2* (r = −0.158) values. Overall, we show that axial T1ρ effectively assesses early LFJ cartilage degeneration. Using T1ρ analysis, we propose a link between LFJ degeneration and IVD NP or

Short-term test-retest-reliability of conditioned pain modulation using the cold-heat-pain method in healthy subjects and its correlation to parameters of standardized quantitative sensory testing.

PubMed

Gehling, Julia; Mainka, Tina; Vollert, Jan; Pogatzki-Zahn, Esther M; Maier, Christoph; Enax-Krumova, Elena K

2016-08-05

Conditioned Pain Modulation (CPM) is often used to assess human descending pain inhibition. Nine different studies on the test-retest-reliability of different CPM paradigms have been published, but none of them has investigated the commonly used heat-cold-pain method. The results vary widely and therefore, reliability measures cannot be extrapolated from one CPM paradigm to another. Aim of the present study was to analyse the test-retest-reliability of the common heat-cold-pain method and its correlation to pain thresholds. We tested the short-term test-retest-reliability within 40 ± 19.9 h using a cold-water immersion (10 °C, left hand) as conditioning stimulus (CS) and heat pain (43-49 °C, pain intensity 60 ± 5 on the 101-point numeric rating scale, right forearm) as test stimulus (TS) in 25 healthy right-handed subjects (12females, 31.6 ± 14.1 years). The TS was applied 30s before (TSbefore), during (TSduring) and after (TSafter) the 60s CS. The difference between the pain ratings for TSbefore and TSduring represents the early CPM-effect, between TSbefore and TSafter the late CPM-effect. Quantitative sensory testing (QST, DFNS protocol) was performed on both sessions before the CPM assessment. paired t-tests, Intraclass correlation coefficient (ICC), standard error of measurement (SEM), smallest real difference (SRD), Pearson's correlation, Bland-Altman analysis, significance level p < 0.05 with Bonferroni correction for multiple comparisons, when necessary. Pain ratings during CPM correlated significantly (ICC: 0.411…0.962) between both days, though ratings for TSafter were lower on day 2 (p < 0.005). The early (day 1: 16.7 ± 11.7; day 2: 19.5 ± 11.9; ICC: 0.618, SRD: 20.2) and late (day 1: 1.7 ± 9.2; day 2: 7.6 ± 11.5; ICC: 0.178, SRD: 27.0) CPM effect did not differ significantly between both days. Both early and late CPM-effects did not correlate with the pain thresholds. The short-term test-retest-reliability of the early CPM-effect using the

Outcome of transforaminal lumbar interbody fusion in spondylolisthesis-A clinico-radiological correlation.

PubMed

Balasubramanian, Vijay Anand; Douraiswami, Balaji; Subramani, Suresh

2018-06-01

Lumbar spondylolisthesis is a common cause of morbidity in middle aged individuals. Spinal fusion with instrumentation has become the gold standard for lumbar segmental instability. Studies which correlate the improvement in radiology postoperatively with functional outcome show contrasting reports. This study is aimed at finding the correlation between clinical and radiological outcomes after surgery with transforaminal lumbar interbody fusion. A retrospective study in 35 patients who underwent transforaminal lumbar interbody fusion in a period of 1 year was done. Preoperative pain (VAS Score), functional ability (ODI), radiological parameters (slip angle, slip grade, disc height, foraminal height, lumbar lordosis) were compared with postoperative recordings at the last followup. Functional improvement (Macnab's criteria) and fusion (Lee's fusion criteria) were assessed. Statistical analysis was done with student's paired t -test and Pearson's correlation coefficient. VAS score, ODI improved from 8 to 2 and 70 to 15 respectively. Slip angle improved from 23°to 5° on an average. 80% patients showed fusion and 85% showed good clinical outcome at 1 year followup. Analyzing with Pearson correlation coefficient showed no significant relation between pain scores and radiological parameters. But there was statistically significant relation between radiological fusion and the final clinical outcome. TLIF produces spinal fusion in most individuals. Strong spinal fusion is essential for good clinical outcome in spondylolisthesis patients who undergo TLIF. Reduction in slip is not necessary for all patients with listhesis.

Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients

PubMed Central

Castro-Sesquen, Yagahira E.; Gilman, Robert H.; Mejia, Carolina; Clark, Daniel E.; Choi, Jeong; Reimer-McAtee, Melissa J.; Castro, Rosario; Valencia-Ayala, Edward; Flores, Jorge; Bowman, Natalie; Castillo-Neyra, Ricardo; Torrico, Faustino; Liotta, Lance; Bern, Caryn; Luchini, Alessandra

2016-01-01

Background Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. Methodology/Principal Findings T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Conclusion Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co

Neyman-Pearson biometric score fusion as an extension of the sum rule

NASA Astrophysics Data System (ADS)

Hube, Jens Peter

2007-04-01

We define the biometric performance invariance under strictly monotonic functions on match scores as normalization symmetry. We use this symmetry to clarify the essential difference between the standard score-level fusion approaches of sum rule and Neyman-Pearson. We then express Neyman-Pearson fusion assuming match scores defined using false acceptance rates on a logarithmic scale. We show that by stating Neyman-Pearson in this form, it reduces to sum rule fusion for ROC curves with logarithmic slope. We also introduce a one parameter model of biometric performance and use it to express Neyman-Pearson fusion as a weighted sum rule.

Y balance test has no correlation with the Stability Index of the Biodex Balance System.

PubMed

Almeida, Gabriel Peixoto Leão; Monteiro, Isabel Oliveira; Marizeiro, Débora Fortes; Maia, Laísa Braga; de Paula Lima, Pedro Olavo

2017-02-01

A cross-sectional study design. The Stability Index of the Biodex Balance System (SI-BBS) and Y Balance Test (YBT) has been used in studies assessing postural stability but no studies have verified the association of the YBT with the SI-BBS. To analyze the association of the Y Balance Test (YBT) with the Stability Index of the Biodex Balance System (SI-BBS) to evaluate postural stability. Forty participants who engaged in recreational physical activities, 12 of whom had a history of injury to the lower limbs. Was used the SI-BBS and the anterior, posterolateral, posteromedial, and composite measures of the YBT. The order of execution of the tests and of the lower limbs evaluated was randomized and blind tested by two evaluators. Pearson's correlation coefficient was used to check the strength of the relationship between the distances achieved on the YBT and the SI-BBS. The YBT showed excellent reliability in the anterior, posteromedial, and posterolateral directions. However, the YBT showed no statistically significant correlation with any variables in the SI-BBS, indicating poor validity between YBT and SI-BBS assessments of postural stability in people with and without history of lower limb injuries. The results of this study showed the YBT is not correlated with the SI-BBS as an assessment of postural stability. This finding has implications for researchers and clinicians using YBT results as the only measure of postural stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Correlation between benzene and testosterone in workers exposed to urban pollution.

PubMed

Rosati, M V; Sancini, A; Tomei, F; Sacco, C; Traversini, V; De Vita, A; De Cesare, D P; Giammichele, G; De Marco, F; Pagliara, F; Massoni, F; Ricci, L; Tomei, G; Ricci, S

2017-01-01

Many studies have examined the effects of benzene on testosterone. The purpose of this study was to evaluate the possible correlation between the blood levels of benzene and the levels of testosterone. The study involved a group of 148 subjects. For every worker have been made out a blood sample for the evaluation of benzene and testosterone levels and an urine analysis for the evaluation of the levels of trans, trans-muconic acid and S-phenylmercapturic acid. We estimated the Pearson correlation coefficient between the variables in the sample and the urinary metabolites, age, length of service, gender, BMI. For the analysis of the major confounding factors it was performed a multiple linear regression. The Pearson correlation coefficiet showed: 1. a significant inverse correlation between the S-phenyl mercapturic acid and free testosterone; 2. a significant direct correlation between trans-trans muconic acid and BMI. After dividing the sample according to the median of blood benzene (161.0 ng / L), Pearson correlation coefficient showed a significant inverse correlation between the S-phenyl mercapturic acid and free testosterone in the group with values below this median. Our results, to be considered preliminary, suggest that occupational exposure to low levels of benzene, present in urban pollution, affect the blood levels of testosterone. These results need to be confirmed in future studies, with the eventual possibility of including more specific fertility tests.

When "t"-Tests or Wilcoxon-Mann-Whitney Tests Won't Do

ERIC Educational Resources Information Center

McElduff, Fiona; Cortina-Borja, Mario; Chan, Shun-Kai; Wade, Angie

2010-01-01

"t"-Tests are widely used by researchers to compare the average values of a numeric outcome between two groups. If there are doubts about the suitability of the data for the requirements of a "t"-test, most notably the distribution being non-normal, the Wilcoxon-Mann-Whitney test may be used instead. However, although often…

Correlation Revelation: The Search for Meaning in Pearson's Coefficient

ERIC Educational Resources Information Center

Huhn, Craig

2016-01-01

When the author was first charged with getting a group of students to understand the correlation coefficient, he did not anticipate the topic would challenge his own understanding, let alone cause him to eventually question the very nature of mathematics itself. On the surface, the idea seemed straightforward, one that millions of students across…

Physiological Background of Differences in Quantitative Diffusion-Weighted Magnetic Resonance Imaging Between Acute Malignant and Benign Vertebral Body Fractures: Correlation of Apparent Diffusion Coefficient With Quantitative Perfusion Magnetic Resonance Imaging Using the 2-Compartment Exchange Model.

PubMed

Geith, Tobias; Biffar, Andreas; Schmidt, Gerwin; Sourbron, Steven; Dietrich, Olaf; Reiser, Maximilian; Baur-Melnyk, Andrea

2015-01-01

To test the hypothesis that apparent diffusion coefficient (ADC) in vertebral bone marrow of benign and malignant fractures is related to the volume of the interstitial space, determined with dynamic contrast-enhanced (DCE) magnetic resonance imaging. Patients with acute benign (n = 24) and malignant (n = 19) vertebral body fractures were examined at 1.5 T. A diffusion-weighted single-shot turbo-spin-echo sequence (b = 100 to 600 s/mm) and DCE turbo-FLASH sequence were evaluated. Regions of interest were manually selected for each fracture. Apparent diffusion coefficient was determined with a monoexponential decay model. The DCE magnetic resonance imaging concentration-time curves were analyzed using a 2-compartment tracer-kinetic model. Apparent diffusion coefficient showed a significant positive correlation with interstitial volume in the whole study population (Pearson r = 0.66, P < 0.001), as well as in the malignant (Pearson r = 0.64, P = 0.004) and benign (Pearson r = 0.52, P = 0.01) subgroup. A significant correlation between ADC and the permeability-surface area product could be observed when analyzing the whole study population (Spearman rs = 0.40, P = 0.008), but not when separately examining the subgroups. Plasma flow showed a significant correlation with ADC in benign fractures (Pearson r = 0.23, P = 0.03). Plasma volume did not show significant correlations with ADC. The results support the hypothesis that the ADC of a lesion is inversely correlated to its cellularity. This explains previous observations that ADC is reduced in more malignant lesions.

Comparison and correlation of pelvic parameters between low-grade and high-grade spondylolisthesis.

PubMed

Min, Woo-Kie; Lee, Chang-Hwa

2014-05-01

This study was retrospectively conducted on 51 patients with L5-S1 spondylolisthesis. This study was conducted to compare a total of 11 pelvic parameters, such as the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, pelvic incidence (PI), L5 inclination, L5 slope, pelvic tilt (PT), and sacral slope (SS) between low-grade and high-grade spondylolisthesis, and to investigate a correlation of the level of displacement by Meyerding method with other pelvic parameters. Pelvic parameters were measured using preoperational erect lateral spinal simple radiographs. The patients were divided into 39 patients with low-grade spondylolisthesis and 12 patients with high-grade spondylolisthesis before analysis. In all patients of both groups, 11 radiographic measurements including the level of displacement by Meyerding method, lumbar lordosis, sacral inclination, lumbosacral angle, slip angle, S2 inclination, PI, L5 inclination, L5 slope, PT, and SS were performed. T test and Pearson correlation analysis were conducted to compare and analyze each measurement. As for the comparison between the 2 groups, a statistically great significance in the level of displacement by Meyerding method, lumbosacral angle, slip angle, L5 incidence, PI, and L5 slope (P≤0.001) was shown. Meanwhile, a statistical significance in the sacral inclination and PT (P<0.05) was also shown. However, no statistical significance in the S2 incidence and SS was shown. A correlation of the level of displacement by Meyerding method with each parameter was analyzed in the both the groups. A high correlation was observed in the lumbar lordosis, lumbosacral angle, slip angle, L5 incidence, and L5 slope (Pearson correlation coefficient, P=0.01), as well as the sacral inclination, PI, and PT (Pearson correlation coefficient, P=0.05). Meanwhile, no correlation was shown in the S2 incidence and SS. A significant difference in the lumbosacral

Contrasting weight changes with LY2605541, a novel long-acting insulin, and insulin glargine despite similar improved glycaemic control in T1DM and T2DM.

PubMed

Jacober, S J; Rosenstock, J; Bergenstal, R M; Prince, M J; Qu, Y; Beals, J M

2014-04-01

The basal insulin analogue LY2605541, a PEGylated insulin lispro with prolonged duration of action, was previously shown to be associated with modest weight loss in Phase 2, randomized, open-label trials in type 2 (N=288) and type 1 (N=137) diabetes mellitus (T2DM and T1DM), compared with modest weight gain with insulin glargine. Exploratory analyses were conducted to further characterize these findings. Pearson correlations between change in body weight and other variables were calculated. Continuous variables were analysed using a mixed linear model with repeated measurements. Proportions of subjects with weight loss were analysed using Fisher's exact test for T2DM and Nagelkerke's method for T1DM. Weight loss was more common in LY2605541-treated patients than in patients treated with insulin glargine (T2DM: 56.9 vs. 40.2%, p=0.011; T1DM: 66.1 vs. 40.3%, p<0.001). More LY2605541-treated patients experienced ≥5% weight loss compared to patients treated with glargine (T2DM: 4.8 vs. 0%, p=0.033; T1DM: 11.9 vs. 0.8%, p<0.001). In both the T1DM and T2DM studies, weight change did not correlate with baseline body mass index (BMI), or change in HDL-cholesterol in either treatment group. No consistent correlations were found across both studies between weight change and any of the variables assessed; however, weight change was significantly correlated with hypoglycaemia rate in glargine-treated T2DM patients. In two Phase 2 trials, improved glycaemic control with long-acting basal insulin analogue LY2605541 is associated with weight loss in previously insulin-treated patients. This weight change is independent of baseline BMI or hypoglycaemia.

Correlation of diffusion tensor imaging parameters with neural status in Pott's spine.

PubMed

Jain, Nikhil; Saini, Namita Singh; Kumar, Sudhir; Rajagopalan, Mukunth; Chakraborti, Kanti Lal; Jain, Anil Kumar

2016-04-29

Diffusion tensor imaging (DTI) has been used in cervical trauma and spondylotic myelopathy, and it has been found to correlate with neural deficit and prognosticate neural recovery. Such a correlation has not been studied in Pott's spine with paraplegia. Hence, this prospective study has been used to find correlation of DTI parameters with neural deficit in these patients. Thirty-four patients of spinal TB were enrolled and DTI was performed before the start of treatment and after six months. Fractional anisotropy (FA), Mean diffusivity (MD), and Tractography were studied. Neurological deficit was graded by the Jain and Sinha scoring. Changes in FA and MD at and below the site of lesion (SOL) were compared to above the SOL (control) using the unpaired t-test. Pre-treatment and post-treatment values were also compared using the paired t-test. Correlation of DTI parameters with neurological score was done by Pearson's correlation. Subjective assessment of Tractography images was done. Mean average FA was not significantly decreased at the SOL in patients with paraplegia as compared to control. After six months of treatment, a significant decrease (p = 0.02) in mean average FA at the SOL compared to pre-treatment was seen. Moderate positive correlation (r = 0.49) between mean average FA and neural score after six months of treatment was found. Tractography images were not consistent with severity of paraplegia. Unlike spondylotic myelopathy and trauma, epidural collection and its organized inflammatory tissue in Pott's spine precludes accurate assessment of diffusion characteristics of the compressed cord.

Factors that influence disease-specific quality of life or health status in patients with COPD: a review and meta-analysis of Pearson correlations.

PubMed

Tsiligianni, Ioanna; Kocks, Janwillem; Tzanakis, Nikolaos; Siafakas, Nikolaos; van der Molen, Thys

2011-09-01

A major goal in the management of chronic obstructive pulmonary disease (COPD) is to ensure that the burden of the disease for patients with COPD is limited and that patients will have the best possible quality of life. To explore all the possible factors that could influence disease-specific quality of life and health status in patients with COPD. A systematic review of the literature and a meta-analysis were performed to explore the factors that could have a positive or negative effect on quality of life and/or health status in patients with COPD. Quality of life and health status are determined by certain factors included gender, disease severity indices, lung function parameters, body mass index, smoking, symptoms, co-morbidity, depression, anxiety, and exacerbations. Factors such as dyspnoea, depression, anxiety and exercise tolerance were found to be more correlated with health status than the widely used spirometric values. Forced expiratory volume in one second had a weak to modest Pearson weighted correlation coefficient which ranged from -0.110 to -0.510 depending on the questionnaire used. The broad range of determining factors suggests that, in order to reach the management goals, health status should be measured in addition to lung function in patients with COPD.

Classification of probability densities on the basis of Pearson?s curves with application to coronal heating simulations

NASA Astrophysics Data System (ADS)

Podladchikova, O.; Lefebvre, B.; Krasnoselskikh, V.; Podladchikov, V.

An important task for the problem of coronal heating is to produce reliable evaluation of the statistical properties of energy release and eruptive events such as micro-and nanoflares in the solar corona. Different types of distributions for the peak flux, peak count rate measurements, pixel intensities, total energy flux or emission measures increases or waiting times have appeared in the literature. This raises the question of a precise evaluation and classification of such distributions. For this purpose, we use the method proposed by K. Pearson at the beginning of the last century, based on the relationship between the first 4 moments of the distribution. Pearson's technique encompasses and classifies a broad range of distributions, including some of those which have appeared in the literature about coronal heating. This technique is successfully applied to simulated data from the model of Krasnoselskikh et al. (2002). It allows to provide successful fits to the empirical distributions of the dissipated energy, and to classify them as a function of model parameters such as dissipation mechanisms and threshold.

Clinical and Pathological Staging Validation in the Eighth Edition of the TNM Classification for Lung Cancer: Correlation between Solid Size on Thin-Section Computed Tomography and Invasive Size in Pathological Findings in the New T Classification.

PubMed

Aokage, Keiju; Miyoshi, Tomohiro; Ishii, Genichiro; Kusumoto, Masahiro; Nomura, Shogo; Katsumata, Shinya; Sekihara, Keigo; Hishida, Tomoyuki; Tsuboi, Masahiro

2017-09-01

The aim of this study was to validate the new eighth edition of the TNM classification and to elucidate whether radiological solid size corresponds to pathological invasive size incorporated in this T factor. We analyzed the data on 1792 patients who underwent complete resection from 2003 to 2011 at the National Cancer Center Hospital East, Japan. We reevaluated preoperative thin-section computed tomography (TSCT) to determine solid size and pathological invasive size using the fourth edition of the WHO classification and reclassified them according to the new TNM classification. The discriminative power of survival curves by the seventh edition was compared with that by the eighth edition by using concordance probability estimates and Akaike's information criteria calculated using a univariable Cox regression model. Pearson's correlation coefficient was calculated to elucidate the correlation between radiological solid size using TSCT and pathological invasive size. The overall survival curves in the eighth edition were well distinct at each clinical and pathological stage. The 5-year survival rates of patients with clinical and pathological stage 0 newly defined were both 100%. The concordance probability estimate and Akaike's information criterion values of the eighth edition were higher than those of the seventh edition in discriminatory power for overall survival. Solid size on TSCT scan and pathological invasive size showed a positive linear relationship, and Pearson's correlation coefficient was calculated as 0.83, which indicated strong correlation. This TNM classification will be feasible regarding patient survival, and radiological solid size correlates significantly with pathological invasive size as a new T factor. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Evaluation of paper gradient concentration strips for antifungal combination testing of Candida spp.

PubMed

Siopi, Maria; Siafakas, Nikolaos; Zerva, Loukia; Meletiadis, Joseph

2015-11-01

In vitro combination testing with broth microdilution chequerboard (CHEQ) method is widely used although it is time-consuming, cumbersome and difficult to apply in routine setting of clinical microbiology laboratory. A new gradient concentration paper strip method, the Liofilchem(®) MIC test strips (MTS), provides an alternative easy and fast method enabling the simultaneous diffusion of both drugs in combination. We therefore tested a polyene+azole and an azole+echinocandin combination against 18 Candida isolates with the CHEQ method based on EUCAST guidelines and the MTS method in research and routine settings. Fractional inhibitory concentration (FIC) indices were calculated after 24 and 48 h of incubation based on complete and prominent (FIC-2) growth inhibition endpoints. Reproducibility and agreement within 1 twofold dilution was assessed. The FICs of the two methods were correlated quantitatively with t-test and Pearson analysis and qualitatively with Chi-squared test. The reproducibility of the CHEQ and MTS method was 88-100% and their agreement was 80% with 62-77% of MTS FICs being higher than the corresponding CHEQ FICs. A statistically significant Pearson correlation (r = 0.86, P = 0.0003) and association (χ(2) = 17.05, df = 4, P = 0.002) was found between MTS FIC and CHEQ FIC-2 after 24 h. Categorical agreement was 63% with no very major or major errors. All MTS synergistic interactions were also synergistic with the CHEQ method. © 2015 Blackwell Verlag GmbH.

Test-retest stability of the Task and Ego Orientation Questionnaire.

PubMed

Lane, Andrew M; Nevill, Alan M; Bowes, Neal; Fox, Kenneth R

2005-09-01

Establishing stability, defined as observing minimal measurement error in a test-retest assessment, is vital to validating psychometric tools. Correlational methods, such as Pearson product-moment, intraclass, and kappa are tests of association or consistency, whereas stability or reproducibility (regarded here as synonymous) assesses the agreement between test-retest scores. Indexes of reproducibility using the Task and Ego Orientation in Sport Questionnaire (TEOSQ; Duda & Nicholls, 1992) were investigated using correlational (Pearson product-moment, intraclass, and kappa) methods, repeated measures multivariate analysis of variance, and calculating the proportion of agreement within a referent value of +/-1 as suggested by Nevill, Lane, Kilgour, Bowes, and Whyte (2001). Two hundred thirteen soccer players completed the TEOSQ on two occasions, 1 week apart. Correlation analyses indicated a stronger test-retest correlation for the Ego subscale than the Task subscale. Multivariate analysis of variance indicated stability for ego items but with significant increases in four task items. The proportion of test-retest agreement scores indicated that all ego items reported relatively poor stability statistics with test-retest scores within a range of +/-1, ranging from 82.7-86.9%. By contrast, all task items showed test-retest difference scores ranging from 92.5-99%, although further analysis indicated that four task subscale items increased significantly. Findings illustrated that correlational methods (Pearson product-moment, intraclass, and kappa) are influenced by the range in scores, and calculating the proportion of agreement of test-retest differences with a referent value of +/-1 could provide additional insight into the stability of the questionnaire. It is suggested that the item-by-item proportion of agreement method proposed by Nevill et al. (2001) should be used to supplement existing methods and could be especially helpful in identifying rogue items in the

Histological correlation of 7 T multi-parametric MRI performed in ex-vivo Achilles tendon.

PubMed

Juras, Vladimir; Apprich, Sebastian; Pressl, Christina; Zbyn, Stefan; Szomolanyi, Pavol; Domayer, Stephan; Hofstaetter, Jochen G; Trattnig, Siegfried

2013-05-01

The goal of this in vitro validation study was to investigate the feasibility of biochemical MRI techniques, such as sodium imaging, T₂ mapping, fast imaging with steady state precession (FISP), and reversed FISP (PSIF), as potential markers for collagen, glycosaminoglycan and water content in the Achilles tendon. Five fresh cadaver ankles acquired from a local anatomy department were used in the study. To acquire a sodium signal from the Achilles tendon, a 3D-gradient-echo sequence, optimized for sodium imaging, was used with TE=7.71 ms and TR=17 ms. The T₂ relaxation times were obtained using a multi-echo, spin-echo technique with a repetition time (TR) of 1200 ms and six echo times. A 3D, partially balanced, steady-state gradient echo pulse sequence was used to acquire FISP and PSIF images, with TR/TE=6.96/2.46 ms. MRI parameters were correlated with each other, as well as with histologically assessed glycosaminoglycan and water content in cadaver Achilles tendons. The highest relevant Pearson correlation coefficient was found between sodium SNR and glycosaminoglycan content (r=0.71, p=0.007). Relatively high correlation was found between the PSIF signal and T2 values (r=0.51, p=0.036), and between the FISP signal and T₂ values (r=0.56, p=0.047). Other correlations were found to be below the moderate level. This study demonstrated the feasibility of progressive biochemical MRI methods for the imaging of the AT. A GAG-specific, contrast-free method (sodium imaging), as well as collagen- and water-sensitive methods (T₂ mapping, FISP, PSIF), may be used in fast-relaxing tissues, such as tendons, in reasonable scan times. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Correlation between hippocampal volumes and medial temporal lobe atrophy in patients with Alzheimer's disease.

PubMed

Dhikav, Vikas; Duraiswamy, Sharmila; Anand, Kuljeet Singh

2017-01-01

Hippocampus undergoes atrophy in patients with Alzheimer's disease (AD). Calculation of hippocampal volumes can be done by a variety of methods using T1-weighted images of magnetic resonance imaging (MRI) of the brain. Medial temporal lobes atrophy (MTL) can be rated visually using T1-weighted MRI brain images. The present study was done to see if any correlation existed between hippocampal volumes and visual rating scores of the MTL using Scheltens Visual Rating Method. We screened 84 subjects presented to the Department of Neurology of a Tertiary Care Hospital and enrolled forty subjects meeting the National Institute of Neurological and Communicative Disorders and Stroke, AD related Disease Association criteria. Selected patients underwent MRI brain and T1-weighted images in a plane perpendicular to long axis of hippocampus were obtained. Hippocampal volumes were calculated manually using a standard protocol. The calculated hippocampal volumes were correlated with Scheltens Visual Rating Method for Rating MTL. A total of 32 cognitively normal age-matched subjects were selected to see the same correlation in the healthy subjects as well. Sensitivity and specificity of both methods was calculated and compared. There was an insignificant correlation between the hippocampal volumes and MTL rating scores in cognitively normal elderly ( n = 32; Pearson Correlation coefficient = 0.16, P > 0.05). In the AD Group, there was a moderately strong correlation between measured hippocampal volumes and MTL Rating (Pearson's correlation coefficient = -0.54; P < 0.05. There was a moderately strong correlation between hippocampal volume and Mini-Mental Status Examination in the AD group. Manual delineation was superior compared to the visual method ( P < 0.05). Good correlation was present between manual hippocampal volume measurements and MTL scores. Sensitivity and specificity of manual measurement of hippocampus was higher compared to visual rating scores for MTL in patients

Correlation between hippocampal volumes and medial temporal lobe atrophy in patients with Alzheimer's disease

PubMed Central

Dhikav, Vikas; Duraiswamy, Sharmila; Anand, Kuljeet Singh

2017-01-01

Introduction: Hippocampus undergoes atrophy in patients with Alzheimer's disease (AD). Calculation of hippocampal volumes can be done by a variety of methods using T1-weighted images of magnetic resonance imaging (MRI) of the brain. Medial temporal lobes atrophy (MTL) can be rated visually using T1-weighted MRI brain images. The present study was done to see if any correlation existed between hippocampal volumes and visual rating scores of the MTL using Scheltens Visual Rating Method. Materials and Methods: We screened 84 subjects presented to the Department of Neurology of a Tertiary Care Hospital and enrolled forty subjects meeting the National Institute of Neurological and Communicative Disorders and Stroke, AD related Disease Association criteria. Selected patients underwent MRI brain and T1-weighted images in a plane perpendicular to long axis of hippocampus were obtained. Hippocampal volumes were calculated manually using a standard protocol. The calculated hippocampal volumes were correlated with Scheltens Visual Rating Method for Rating MTL. A total of 32 cognitively normal age-matched subjects were selected to see the same correlation in the healthy subjects as well. Sensitivity and specificity of both methods was calculated and compared. Results: There was an insignificant correlation between the hippocampal volumes and MTL rating scores in cognitively normal elderly (n = 32; Pearson Correlation coefficient = 0.16, P > 0.05). In the AD Group, there was a moderately strong correlation between measured hippocampal volumes and MTL Rating (Pearson's correlation coefficient = −0.54; P < 0.05. There was a moderately strong correlation between hippocampal volume and Mini-Mental Status Examination in the AD group. Manual delineation was superior compared to the visual method (P < 0.05). Conclusions: Good correlation was present between manual hippocampal volume measurements and MTL scores. Sensitivity and specificity of manual measurement of hippocampus was

Quadrupolar magic angle spinning NMR spectra fitted using the Pearson IV function.

PubMed

Mironenko, Roman M; Belskaya, Olga B; Talsi, Valentin P; Likholobov, Vladimir A

2014-01-01

The Pearson IV function was used to fit the asymmetric solid-state (27)Al NMR spectra of alumina based catalysts. A high convergence (correlation coefficient is no less than 0.997) between experimental and simulated spectra was achieved. The decomposition of the (27)Al NMR spectra of zinc/aluminum mixed oxides with different Zn/Al molar ratio revealed an increased fraction (6-9%) of pentacoordinated aluminum atoms in these oxides as compared to γ-Al2O3. As the Zn/Al ratio is raised, the fraction of [AlO6] octahedral units decreases, while the fraction of [AlO4] tetrahedra increases. Copyright © 2014 Elsevier Inc. All rights reserved.

Correlation of ADC value with pathologic indexes in colorectal tumor homografts in Balb/c mouse.

PubMed

Li, Xiaojun; Jiang, Hongnan; Niu, Jinliang; Zheng, Ying

2014-08-01

Noninvasive diffusion-weighted magnetic resonance imaging (DWI) is a well-studied MR imaging technique for quantifying water diffusion especially in tumor area. The correlation between apparent diffusion coefficient (ADC) value and apoptosis or proliferation is not clear by now. This study aimed to investigate whether DWI-ADC value could be used as an imaging marker related with pathologic indexes of tumors. A total of 30 Balb/c mice with HT29 colorectal carcinoma were subjected to DWI and histologic analysis. The percentage of ADC changes and the apoptotic and proliferating indexes were calculated at predefined time points. Kolmogorov-Smirnov distances were considered to determine whether the percentage of ADC changes, and the apoptotic and proliferating indexes were normally distributed. An independent-samples t-test was used to analyze the difference between apoptotic and proliferating indexes in the two groups. THERE WAS A STATISTICALLY SIGNIFICANT DIFFERENCE IN PROLIFERATING INDEX BETWEEN THE RADIOTHERAPY AND CONTROL GROUPS (MEAN PROLIFERATING INDEX: 49.27% vs. 83.09%), and there was a statistically significant difference in apoptotic index between the two groups (mean apoptotic index: 37.7% vs. 2.71%). A significant positive correlation was found between the percentage of ADC changes of the viable tissue and apoptotic index. Pearson's correlation coefficient was 0.655 (P=0.015). A significant negative correlation was found between the percentage of ADC changes of the viable tissue and ki-67 proliferation index. Pearson's correlation coefficient was 0.734 (P<0.001). Our results suggest that ADC value may be used in measurement of cell apoptotic and proliferating indexes in colorectal carcinoma.

The aging correlation (RH + t): Relative humidity (%) + temperature (deg C)

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.

1986-01-01

An aging correlation between corrosion lifetime, and relative humidity RH (%) and temperature t (C) has been reported in the literature. This aging correlation is a semi-log plot of corrosion lifetime on the log scale versus the interesting summation term RH(%) + t(C) on the linear scale. This empirical correlation was derived from observation of experimental data trends and has been referred to as an experimental law. Using electrical resistivity data of polyvinyl butyral (PVB) measured as a function of relative humidity and temperature, it was found that the electrical resistivity could be expressed as a function of the term RH(%) t(C). Thus, if corrosion is related to leakage current through an organic insulator, which, in turn, is a function of RH and t, then some partial theoretical validity for the correlation is indicated. This article describes the derivation of the term RH(%) t(C) from PVB electrical resistivity data.

Correlation between thyroidal and peripheral blood total T cells, CD8+ T cells, and CD8+ T- regulatory cells and T-cell reactivity to calsequestrin and collagen XIII in patients with Graves' ophthalmopathy.

PubMed

Al-Ansari, Farah; Lahooti, Hooshang; Stokes, Leanne; Edirimanne, Senarath; Wall, Jack

2018-05-22

Purpose/aim of the study: Graves' ophthalmopathy (GO) is closely related to the thyroid autoimmune disorder Graves' disease. Previous studies have suggested roles for thyroidal CD8 +  T cells and autoimmunity against calsequestrin-1 (CASQ)-1 in the link between thyroidal and orbital autoimmune reactions in GO. A role for autoimmunity against CollXIII has also been suggested. In this study, we aimed to investigate correlations between some thyroidal and peripheral blood T-cell subsets and thyroidal T-cell reactivity against CASQ1 and CollXIII in patients with GO. Fresh thyroid tissues were processed by enzyme digestion and density gradient to isolate mononuclear cells (MNCs). Peripheral blood MNCs were also isolated using density gradient. Flow-cytometric analysis was used to identify the various T-cell subsets. T -cell reactivity to CASQ1 and CollXIII was measured by a 5-day culture of the MNCs and BrdU uptake method. We found a positive correlation between thyroidal CD8 +  T cells and CD8 +  T-regulatory (T-reg) cells in patients with GO. Thyroidal T cells from two out of the three patients with GO tested (66.7%) showed a positive response to CASQ1, while thyroidal T cells from none of the six Graves' Disease patients without ophthalmopathy (GD) tested showed a positive response to this antigen. Thyroidal T cells from these patient groups however, showed no significant differences in their response to CollXIII. Our observations provide further evidence for a possible role of thyroidal CD8 +  T cells, CD8 +  T-reg cells and the autoantigen CASQ1 in the link between thyroidal and orbital autoimmune reactions of GO.

Pathogen-Specific T Cell Polyfunctionality Is a Correlate of T Cell Efficacy and Immune Protection

PubMed Central

Boyd, Anders; Almeida, Jorge R.; Darrah, Patricia A.; Sauce, Delphine; Seder, Robert A.; Appay, Victor; Gorochov, Guy; Larsen, Martin

2015-01-01

Introduction Understanding the factors that delineate the efficacy of T cell responses towards pathogens is crucial for our ability to develop potent therapies against infectious diseases. Multidimensional evaluation of T cell functionality at the single-cell level enables exhaustive analysis of combinatorial functional properties, hence polyfunctionality. We have recently invented an algorithm that quantifies polyfunctionality, the Polyfunctionality Index (Larsen et al. PLoS One 2012). Here we demonstrate that quantitative assessment of T cell polyfunctionality correlates with T cell efficacy measured as the capacity to kill target cells in vitro and control infection in vivo. Methods We employed the polyfunctionality index on two datasets selected for their unique ability to evaluate the polyfunctional imprint on T cell efficacy. 1) HIV-specific CD8+ T cells and 2) Leishmania major-specific CD4+ T cells were analysed for their capacity to secrete multiple effector molecules, kill target cells and control infection. Briefly, employing the Polyfunctionality Index algorithm we determined the parameter estimates resulting in optimal correlation between T cell polyfunctionality and T cell efficacy. Results T cell polyfunctionality is correlated with T cell efficacy measured as 1) target killing (r=0.807, P<0.0001) and 2) lesion size upon challenge with Leishmania major (r=-0.50, P=0.004). Contrary to an approach relying on the Polyfunctionality Index algorithm, quantitative evaluation of T cell polyfunctionality traditionally ignores the gradual contribution of more or less polyfunctional T cells. Indeed, comparing both approaches we show that optimal description of T cell efficacy is obtained when gradually integrating all levels of polyfunctionality in accordance with the Polyfunctionality Index. Conclusions Our study presents a generalizable methodology to objectively evaluate the impact of polyfunctionality on T cell efficacy. We show that T cell polyfunctionality

Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

PubMed

Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

2018-02-01

Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

Meta-Analysis of Correlations Revisited: Attempted Replication and Extension of Field's (2001) Simulation Studies

ERIC Educational Resources Information Center

Hafdahl, Adam R.; Williams, Michelle A.

2009-01-01

In 2 Monte Carlo studies of fixed- and random-effects meta-analysis for correlations, A. P. Field (2001) ostensibly evaluated Hedges-Olkin-Vevea Fisher-[zeta] and Schmidt-Hunter Pearson-r estimators and tests in 120 conditions. Some authors have cited those results as evidence not to meta-analyze Fisher-[zeta] correlations, especially with…

Pearson syndrome: unique endocrine manifestations including neonatal diabetes and adrenal insufficiency.

PubMed

Williams, T B; Daniels, M; Puthenveetil, G; Chang, R; Wang, R Y; Abdenur, J E

2012-05-01

Pearson syndrome is a very rare metabolic disorder that is usually present in infancy with transfusion dependent macrocytic anemia and multiorgan involvement including exocrine pancreas, liver and renal tubular defects. The disease is secondary to a mitochondrial DNA deletion that is variable in size and location. Endocrine abnormalities can develop, but are usually not part of the initial presentation. We report two patients who presented with unusual endocrine manifestations, neonatal diabetes and adrenal insufficiency, who were both later diagnosed with Pearson syndrome. Medical records were reviewed. Confirmatory testing included: mitochondrial DNA deletion testing and sequencing of the breakpoints, muscle biopsy, and bone marrow studies. Case 1 presented with hyperglycemia requiring insulin at birth. She had several episodes of ketoacidosis triggered by stress and labile blood glucose control. Workup for genetic causes of neonatal diabetes was negative. She had transfusion dependent anemia and died at 24 months due to multisystem organ failure. Case 2 presented with adrenal insufficiency and anemia during inturcurrent illness, requiring steroid replacement since 37 months of age. He is currently 4 years old and has mild anemia. Mitochondrial DNA studies confirmed a 4.9 kb deletion in patient 1 and a 5.1 kb deletion in patient 2. The patients reported highlight the importance of considering mitochondrial DNA disorders in patients with early onset endocrine dysfunction, and expand the knowledge about this rare mitochondrial disease. Copyright © 2012 Elsevier Inc. All rights reserved.

MIDAS and HIT-6 French translation: reliability and correlation between tests.

PubMed

Magnoux, E; Freeman, M A; Zlotnik, G

2008-01-01

, with a median of 19 days. The Shrout-Fleiss intraclass correlation coefficients for MIDAS and HIT-6 were, respectively, 0.76 and 0.77 for episodic headaches and 0.83 and 0.80 for chronic headaches. The Pearson correlation coefficient between the MIDAS and HIT-6 questionnaires was 0.48 for episodic headaches and 0.58 for chronic headaches at the first compilation and 0.42 and 0.59 at the second compilation. The test-retest intraclass correlation of the French versions for both MIDAS and HIT-6 questionnaires indicates moderate reliability for episodic headache and substantial reliability for chronic headache. The correlation between the MIDAS and HIT-6 questionnaires is weak for episodic headaches, but approaches a level of 'good' for chronic headaches.

Systematic reviews: I. The correlation between laboratory tests on marginal quality and bond strength. II. The correlation between marginal quality and clinical outcome.

PubMed

Heintze, Siegward D

2007-01-01

An accepted principle in restorative dentistry states that restorations should be placed with the best marginal quality possible to avoid postoperative sensitivity, marginal discoloration, and secondary caries. Different laboratory methods claim to predict the clinical performance of restorative materials, for example, tests of bond strength and microleakage and gap analysis. The purpose of this review was twofold: (1) find studies that correlated the results of bond strength tests with either microleakage or gap analysis for the same materials, and (2) find studies that correlated the results of microleakage and/or gaps with the clinical parameters for the same materials. Furthermore, influencing factors on the results of the laboratory tests were reviewed and assessed. For the first question, searches for studies were conducted in the MEDLINE database and IADR/AADR abtracts online with specific search and inclusion criteria. The outcome for each study was assessed on the basis of the statistical test applied in the study, and finally the number of studies with or without correlation was compiled. For the second question, results of the quantitative marginal analysis of Class V restorations published by the University of Zürich with the same test protocol and prospective clinical trials were searched that investigated the same materials for at least 2 years in Class V cavities. Pearson correlation coefficients were calculated for pooled data of materials and clinical outcome parameters such as retention loss, marginal discoloration, marginal integrity, and secondary caries. For the correlation of dye penetration and clinical outcome, studies on Class V restorations published by the same research institute were searched in MEDLINE that examined the same adhesive systems as the selected clinical trials. For the correlation bond strength/microleakage, 30 studies were included into the review, and for the correlation bond strength/gap analysis 18 studies. For both

A Tunisian patient with Pearson syndrome harboring the 4.977kb common deletion associated to two novel large-scale mitochondrial deletions.

PubMed

Ayed, Imen Ben; Chamkha, Imen; Mkaouar-Rebai, Emna; Kammoun, Thouraya; Mezghani, Najla; Chabchoub, Imen; Aloulou, Hajer; Hachicha, Mongia; Fakhfakh, Faiza

2011-07-29

Pearson syndrome (PS) is a multisystem disease including refractory anemia, vacuolization of marrow precursors and pancreatic fibrosis. The disease starts during infancy and affects various tissues and organs, and most affected children die before the age of 3years. Pearson syndrome is caused by de novo large-scale deletions or, more rarely, duplications in the mitochondrial genome. In the present report, we described a Pearson syndrome patient harboring multiple mitochondrial deletions which is, in our knowledge, the first case described and studied in Tunisia. In fact, we reported the common 4.977kb deletion and two novel heteroplasmic deletions (5.030 and 5.234kb) of the mtDNA. These deletions affect several protein-coding and tRNAs genes and could strongly lead to defects in mitochondrial polypeptides synthesis, and impair oxidative phosphorylation and energy metabolism in the respiratory chain in the studied patient. Copyright © 2011 Elsevier Inc. All rights reserved.

Assessment of the correlation between insertion torque and resonance frequency analysis of implants placed in bone tissue of different densities.

PubMed

Filho, Luiz Carlos Magno; Cirano, Fabiano Ribeiro; Hayashi, Fernando; Feng, Hsu Shao; Conte, Alexandre; Dib, Luciano Lauria; Casati, Marcio Zaffalon

2014-06-01

The primary stability of dental implants is fundamental for osseointegration. Therefore, this study aimed to assess the correlation between insertion torque (IT) and resonance frequency analysis (RFA) of implants placed in mandibles and maxillas of different bone densities. Eighty dental implants were placed in maxillas and mandibles, and IT and the implant stability quotient (ISQ) were measured at the time of implant insertion. Bone density was assessed subjectively by the Lekholm and Zarb index. The type I and II densities were grouped together (group A)as were the type III and IV densities (group B). The IT in group A was higher (Student t test, P = .0013) than in group B (46.27 ± 18.51 Ncm, 33.62 ± 14.74 Ncm, respectively). The implants placed in group A showed higher ISQ (Student t test, P = .0004) than those placed in group B (70.09 ± 7.50, 63.66 ± 8.00, respectively). A significant correlation between IT and the ISQ value was observed for group A (Pearson correlation test; r = 0.35; P = .0213) and for group B (r = 0.37; P = .0224). Within the limitations of this study, it was possible to conclude that there is a correlation between IT and RFA of implants placed in mandibles and maxillas of different bone densities.

Predictive MRI correlates of lesser metatarsophalangeal joint plantar plate tear.

PubMed

Umans, Rachel L; Umans, Benjamin D; Umans, Hilary; Elsinger, Elisabeth

2016-07-01

To identify correlated signs on non-enhanced MRI that might improve diagnostic detection of plantar plate (PP) tear. We performed an IRB-approved, HIPAA-compliant retrospective analysis of 100 non-contrast MRI (50 PP tear, 50 controls). All were anonymized, randomized, and reviewed; 20 were duplicated to assess consistency. One musculoskeletal radiologist evaluated qualitative variables. A trained non-physician performed measurements. Consistency and concordance were assessed. Pearson's Chi-square test was used to test the correlation between qualitative findings and PP tear status. Correlation between measurements and PP status was assessed using t tests and Wilcoxon's rank-sum test (p values < 0.05 considered significant). Classification and regression trees were utilized to identify attributes that, taken together, would consistently distinguish PP tear from controls. Quantitative measurements were highly reproducible (concordance 0.88-0.99). Elevated 2nd MT protrusion, lesser MT supination and rotational divergence of >45° between the 1st-2nd MT axis correlated with PP tear. Pericapsular soft tissue thickening correlated most strongly with PP tear, correctly classifying 95 % of cases and controls. Excluding pericapsular soft tissue thickening, sequential assessment of 2nd toe enthesitis, 2nd flexor tendon subluxation, and splaying of the second and third toes accurately classified PP status in 92 %. Pericapsular soft tissue thickening most strongly correlated with PP tear. For cases in which it might be difficult to distinguish pericapsular fibrosis from neuroma, sequential assessment of 2nd toe enthesitis, flexor tendon subluxation and splaying of the 2nd and 3rd toe is most helpful for optimizing accurate diagnosis of PP tear.

"It was a young man's life": G.A. Pearson (P-53)

Treesearch

Susan D. Olberding

2008-01-01

The nation's initial USFS research site commenced in a rustic cabin in the midst of northern Arizona’s expansive ponderosa pine forest. Gustaf A. Pearson was the first in a distinguished line of USFS scientists to live and study there. A visitor to Fort Valley today often wishes he could have stood in Pearson's large boots (he was said to have enormous feet)...

Meta-analysis of correlations revisited: attempted replication and extension of Field's (2001) simulation studies.

PubMed

Hafdahl, Adam R; Williams, Michelle A

2009-03-01

In 2 Monte Carlo studies of fixed- and random-effects meta-analysis for correlations, A. P. Field (2001) ostensibly evaluated Hedges-Olkin-Vevea Fisher-z and Schmidt-Hunter Pearson-r estimators and tests in 120 conditions. Some authors have cited those results as evidence not to meta-analyze Fisher-z correlations, especially with heterogeneous correlation parameters. The present attempt to replicate Field's simulations included comparisons with analytic values as well as results for efficiency and confidence-interval coverage. Field's results under homogeneity were mostly replicable, but those under heterogeneity were not: The latter exhibited up to over .17 more bias than ours and, for tests of the mean correlation and homogeneity, respectively, nonnull rejection rates up to .60 lower and .65 higher. Changes to Field's observations and conclusions are recommended, and practical guidance is offered regarding simulation evidence and choices among methods. Most cautions about poor performance of Fisher-z methods are largely unfounded, especially with a more appropriate z-to-r transformation. The Appendix gives a computer program for obtaining Pearson-r moments from a normal Fisher-z distribution, which is used to demonstrate distortion due to direct z-to-r transformation of a mean Fisher-z correlation.

Correlation between production performance and feeding behavior of steers on pasture during the rainy-dry transition period.

PubMed

Brandão, Rita K C; de Carvalho, Gleidson G P; Silva, Robério R; Dias, Daniel L S; Mendes, Fabrício B L; Lins, Túlio O J D'A; Pereira, Maria M S; Guimarães, Joanderson O; Tosto, Manuela S L; Rufino, Luana M de A; de Araujo, Maria L G M L

2018-01-01

The aim of this study was to evaluate the correlation between production performance and feeding behavior of steers reared on pasture during the rainy-dry transition period. Twenty-two ½ Holstein-Zebu crossbred steers at an average age of 10 months and with an average initial body weight of 234.5 ± 16.0 kg were distributed in a completely randomized design with two types of supplementation and eleven replications. Pearson's linear correlation analysis was performed between behavioral variables and weight gain and feed conversion. Correlation coefficients were tested by the t test. The time expended feeding at the trough was positively correlated (P < 0.05) with average daily gain (ADG) and with the number of periods of permanence at the trough. Bite rate and the number of bites per day were positively correlated (P < 0.05) with ADG and negatively (P < 0.05) with feed conversion, unlike the number of bites per swallow, which was negatively correlated (P < 0.05) with ADG. There was a positive correlation (P < 0.05) between feed efficiency in dry matter and neutral detergent fiber and ADG. Feeding behavior characteristics have little association with the production performance of cattle on pasture receiving mineral or energy-protein supplementation.

T\\overline{T} -deformations, AdS/CFT and correlation functions

NASA Astrophysics Data System (ADS)

Giribet, Gaston

2018-02-01

A solvable irrelevant deformation of AdS3/CFT2 correspondence leading to a theory with Hagedorn spectrum at high energy has been recently proposed. It consists of a single trace deformation of the boundary theory, which is inspired by the recent work on solvable T\\overline{T} deformations of two-dimensional CFTs. Thought of as a worldsheet σ-model, the interpretation of the deformed theory from the bulk viewpoint is that of string theory on a background that interpolates between AdS3 in the IR and a linear dilaton vacuum of little string theory in the UV. The insertion of the operator that realizes the deformation in the correlation functions produces a logarithmic divergence, leading to the renormalization of the primary operators, which thus acquire an anomalous dimension. We compute this anomalous dimension explicitly, and this provides us with a direct way of determining the spectrum of the theory. We discuss this and other features of the correlation functions in presence of the deformation.

A Study of Correlation of Various Growth Indicators with Chronological Age.

PubMed

Singh, Sarabjeet; Sandhu, Navreet; Puri, Taruna; Gulati, Ritika; Kashyap, Rita

2015-01-01

The aim of this study was to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth and a correlation, if any, among the three variables. The samples were derived from lateral cephalometric radiographs of 80 subjects (40 males, 40 females; age range: 10 to 19 years). Cervical vertebral development was evaluated by the method of Hassel and Farman, frontal sinus width was measured by the method described by Ertürk and antegonial notch depth as described by Singer et al. The Pearson's correlation coefficients were estimated to assess the relationship of chronological age with cervical vertebrae skeletal maturation, frontal sinus width and antegonial notch depth. The Pearson's correlation coefficient were 0.855 (p < 0.001) between chronological age and cervical vertebrae skeletal maturation, and 0.333 (p < 0.001) between chronological age and frontal sinus width. A highly significant positive correlation was found between chronological age and cervical vertebrae skeletal maturation, and between chronological age and frontal sinus width. Nonsignificant correlation was found between chronological age and antegonial notch depth. How to cite this article: Singh S, Sandhu N, Puri T, Gulati R, Kashyap R. A Study of Correlation of Various Growth Indicators with Chronological Age. Int J Clin Pediatr Dent 2015;8(3): 190-195.

Statistical functions and relevant correlation coefficients of clearness index

NASA Astrophysics Data System (ADS)

Pavanello, Diego; Zaaiman, Willem; Colli, Alessandra; Heiser, John; Smith, Scott

2015-08-01

This article presents a statistical analysis of the sky conditions, during years from 2010 to 2012, for three different locations: the Joint Research Centre site in Ispra (Italy, European Solar Test Installation - ESTI laboratories), the site of National Renewable Energy Laboratory in Golden (Colorado, USA) and the site of Brookhaven National Laboratories in Upton (New York, USA). The key parameter is the clearness index kT, a dimensionless expression of the global irradiance impinging upon a horizontal surface at a given instant of time. In the first part, the sky conditions are characterized using daily averages, giving a general overview of the three sites. In the second part the analysis is performed using data sets with a short-term resolution of 1 sample per minute, demonstrating remarkable properties of the statistical distributions of the clearness index, reinforced by a proof using fuzzy logic methods. Successively some time-dependent correlations between different meteorological variables are presented in terms of Pearson and Spearman correlation coefficients, and introducing a new one.

Test-Retest Stability of the Task and Ego Orientation Questionnaire

ERIC Educational Resources Information Center

Lane, Andrew M.; Nevill, Alan M.; Bowes, Neal; Fox, Kenneth R.

2005-01-01

Establishing stability, defined as observing minimal measurement error in a test-retest assessment, is vital to validating psychometric tools. Correlational methods, such as Pearson product-moment, intraclass, and kappa are tests of association or consistency, whereas stability or reproducibility (regarded here as synonymous) assesses the…

Two-colour chewing gum mixing ability test for evaluating masticatory performance in children with mixed dentition: validity and reliability study.

PubMed

Kaya, M S; Güçlü, B; Schimmel, M; Akyüz, S

2017-11-01

The unappealing taste of the chewing material and the time-consuming repetitive task in masticatory performance tests using artificial foodstuff may discourage children from performing natural chewing movements. Therefore, the aim was to determine the validity and reliability of a two-colour chewing gum mixing ability test for masticatory performance (MP) assessment in mixed dentition children. Masticatory performance was tested in two groups: systemically healthy fully dentate young adults and children in mixed dentition. Median particle size was assessed using a comminution test, and a two-colour chewing gum mixing ability test was applied for MP analysis. Validity was tested with Pearson correlation, and reliability was tested with intra-class correlation coefficient, Pearson correlation and Bland-Altman plots. Both comminution and two-colour chewing gum mixing ability tests revealed statistically significant MP differences between children (n = 25) and adults (n = 27, both P < 0·01). Pearson correlation between comminution and two-colour chewing gum mixing ability tests was positive and significant (r = 0·418, P = 0·002). Correlations for interobserver reliability and test-retest values were significant (r = 0·990, P = 0·0001 and r = 0·995, P = 0·0001). Although both methods could discriminate MP differences, the comminution test detected these differences generally in a wider range compared to two-colour chewing gum mixing ability test. However, considering the high reliability of the results, the two-colour chewing gum mixing ability test can be used to assess masticatory performance in children, especially at non-clinical settings. © 2017 John Wiley & Sons Ltd.

Overview of T.E.S.T. (Toxicity Estimation Software Tool)

EPA Science Inventory

This talk provides an overview of T.E.S.T. (Toxicity Estimation Software Tool). T.E.S.T. predicts toxicity values and physical properties using a variety of different QSAR (quantitative structure activity relationship) approaches including hierarchical clustering, group contribut...

Correlation of sex ratio at birth with health and socioeconomic indicators.

PubMed

Grech, Victor

2018-03-01

The sex ratio at birth (male divided by total live births: M/T) has been mooted as a potential sentinel health indicator. Several metrics indicate individual countries' health and socioeconomic status. In this study, in all available countries (where such data was accessible), M/T and these indicators were compared in order to ascertain whether better (vis-à-vis health and socioeconomic status) levels of these indicators were associated with higher M/T in available countries. The following were obtained (by country) from various sources: M/T, infant mortality rate, under 5 years mortality rate, fertility rate, Human Development Index, gross domestic product per capita, life expectancy for both sexes, females, males, as well as both sexes Health Adjusted Life Expectancy (HALE). Pearson correlation was performed comparing M/T and these indicators. Despite weak correlation values, all except for the Human Development Index (HDI) correlated with M/T at statistically significant levels. A decrease in mortality and an increase in life expectancy and GDP/capita are indicators of socioeconomic wellbeing. In this study, mortality was negatively correlated with M/T. Life expectancy and GDP/capita were both positively correlated with M/T, indicating that M/T may also serve as a surrogate health indicator, and incidentally, also supporting the Trivers-Willard hypothesis. Improving economies lead to increasing education, which in turns tends to lower fertility rate in association with a declining M/T. In conclusion, the global correlation of health and socioeconomic indicators with M/T suggests that M/T may be a useful sentinel health indicator. Copyright © 2018 Elsevier B.V. All rights reserved.

Clinical manifestations and management of four children with Pearson syndrome.

PubMed

Tumino, Manuela; Meli, Concetta; Farruggia, Piero; La Spina, Milena; Faraci, Maura; Castana, Cinzia; Di Raimondo, Vincenzo; Alfano, Marivana; Pittalà, Annarita; Lo Nigro, Luca; Russo, Giovanna; Di Cataldo, Andrea

2011-12-01

Pearson marrow-pancreas syndrome is a fatal disorder mostly diagnosed during infancy and caused by mutations of mitochondrial DNA. We hereby report on four children affected by Pearson syndrome with hematological disorders at onset. The disease was fatal to three of them and the fourth one, who received hematopoietic stem cell transplantation, died of secondary malignancy. In this latter patient transplantation corrected hematological and non-hematological issues like metabolic acidosis, and we therefore argue that it could be considered as a useful option in an early stage of the disease. Copyright © 2011 Wiley Periodicals, Inc.

Correlating Species and Spectral Diversity using Remote Sensing in Successional Fields in Virginia

NASA Astrophysics Data System (ADS)

Aneece, I.; Epstein, H. E.

2015-12-01

Conserving biodiversity can help preserve ecosystem properties and function. As the increasing prevalence of invasive plant species threatens biodiversity, advances in remote sensing technology can help monitor invasive species and their effects on ecosystems and plant communities. To assess whether we could study the effects of invasive species on biodiversity using remote sensing, we asked whether species diversity was positively correlated with spectral diversity, and whether correlations differed among spectral regions along the visible and near-infrared range. To answer these questions, we established community plots in secondary successional fields at the Blandy Experimental Farm in northern Virginia and collected vegetation surveys and ground-level hyperspectral data from 350 to 1025 nm wavelengths. Pearson correlation analysis revealed a positive correlation between spectral diversity and species diversity in the visible ranges of 350-499 nm (Pearson correlation=0.69, p=0.01), 500-589 nm (Pearson=0.64, p=0.03), and 590-674 nm (Pearson=0.70, p=0.01), slight positive correlation in the red edge range of 675-754 nm (Pearson=0.56, p=0.06), and no correlation in the near-infrared ranges of 755-924 nm (Pearson=-0.06, p=0.85) and 925-1025 nm (Pearson=0.30, p=0.34). These differences in correlations across spectral regions may be due to the elements that contribute to signatures in those regions and spectral data transformation methods. To investigate the role of pigment variability in these correlations, we estimated chlorophyll, carotenoid, and anthocyanin concentrations of five dominant species in the plots using vegetation indices. Although interspecific variability in pigment levels exceeded intraspecific variability, chlorophyll (F value=118) was more varied within species than carotenoids (F=322) and anthocyanins (F=126), perhaps contributing to the lack of correlation between species diversity and spectral diversity in the red edge region. Interspecific

Incident Energy Dependence of p t Correlations at RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, J.; Aggarwal, M. M.; Ahammed, Z.

2005-10-01

We present results for two-particle transverse momentum correlations, Δp t,iΔ t,j, as a function of event centrality for Au+Au collisions at √( sNN) = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or nomore » beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.« less

Nurse managers' work life quality and their participation in knowledge management: a correlational study.

PubMed

Hashemi Dehaghi, Zahra; Sheikhtaheri, Abbas; Dehnavi, Fariba

2015-01-01

The association between quality of work life and participation in knowledge management is unknown. This study aimed to discover the association between quality of work life of nurse managers and their participation in implementing knowledge management. This was a correlational study. All nurse managers (71 people) from 11 hospitals affiliated with the Social Security Organization in Tehran, Iran, were included. They were asked to rate their participation in knowledge management and their quality of work life. Data was gathered by a researcher-made questionnaire (May-June 2012). The questionnaire was validated by content and construct validity approaches. Cronbach's alpha was used to evaluate reliability. Finally, 50 questionnaires were analyzed. The answers were scored and analyzed using mean of scores, T-test, ANOVA (or nonparametric test, if appropriate), Pearson's correlation coefficient and linear regression. Nurse managers' performance to implement knowledge management strategies was moderate. A significant correlation was found between quality of work life of nurse managers and their participation in implementing knowledge management strategies (r = 0.82; P < 0.001). The strongest correlations were found between implementation of knowledge management and participation of nurse managers in decision making (r = 0.82; P < 0.001). Improvement of nurse managers' work life quality, especially in decision-making, may increase their participation in implementing knowledge management.

Correlation between cell cycle proteins and hMSH2 in actinic cheilitis and lip cancer.

PubMed

Lopes, Maria Luiza Diniz de Sousa; de Oliveira, Denise Hélen Imaculada Pereira; Sarmento, Dmitry José de Santana; Queiroz, Lélia Maria Guedes; Miguel, Márcia Cristina da Costa; da Silveira, Éricka Janine Dantas

2016-04-01

This study aims to evaluate and verify the relationship between the immunoexpression of hMSH2, p53 and p21 in actinic cheilitis (AC) and lower lip squamous cell carcinoma (SCC) cases. Forty AC and 40 SCC cases were submitted to immunoperoxidase method and quantitatively analyzed. Expression was compared by Mann-Whitney test, Student t test or one-way ANOVA. To correlate the variables, Pearson's correlation coefficient was calculated. The expression of p53 and p21 showed no significant differences between histopathological grades of AC or lower lip SCC (p > 0.05). Immunoexpression of p53 was higher in SCC than in AC (p < 0.001), while p21 expression was more observed in AC when compared to SCC group (p = 0.006). The AC group revealed an inverse correlation between p53 and hMSH2 expression (r = -0.30, p = 0.006). Alterations in p53 and p21 expression suggest that these proteins are involved in lower lip carcinogenesis. Moreover, p53 and hMSH2 seem to be interrelated in early events of this process.

End of Course Grades and End of Course Tests in the Virtual Environment: A Study of Correlation

ERIC Educational Resources Information Center

Philipp, Jamie Gilbert

2014-01-01

The purpose of this correlational study is to understand the relationship between end-of-course grades as assigned by teachers and standardized end-of-course scores earned by students in Algebra, Geometry, Biology, Physical Science, and U.S. History courses at one virtual charter school in the State of Georgia. Pearson Product-Moment Correlation…

A New Family of Solvable Pearson-Dirichlet Random Walks

NASA Astrophysics Data System (ADS)

Le Caër, Gérard

2011-07-01

An n-step Pearson-Gamma random walk in ℝ d starts at the origin and consists of n independent steps with gamma distributed lengths and uniform orientations. The gamma distribution of each step length has a shape parameter q>0. Constrained random walks of n steps in ℝ d are obtained from the latter walks by imposing that the sum of the step lengths is equal to a fixed value. Simple closed-form expressions were obtained in particular for the distribution of the endpoint of such constrained walks for any d≥ d 0 and any n≥2 when q is either q = d/2 - 1 ( d 0=3) or q= d-1 ( d 0=2) (Le Caër in J. Stat. Phys. 140:728-751, 2010). When the total walk length is chosen, without loss of generality, to be equal to 1, then the constrained step lengths have a Dirichlet distribution whose parameters are all equal to q and the associated walk is thus named a Pearson-Dirichlet random walk. The density of the endpoint position of a n-step planar walk of this type ( n≥2), with q= d=2, was shown recently to be a weighted mixture of 1+ floor( n/2) endpoint densities of planar Pearson-Dirichlet walks with q=1 (Beghin and Orsingher in Stochastics 82:201-229, 2010). The previous result is generalized to any walk space dimension and any number of steps n≥2 when the parameter of the Pearson-Dirichlet random walk is q= d>1. We rely on the connection between an unconstrained random walk and a constrained one, which have both the same n and the same q= d, to obtain a closed-form expression of the endpoint density. The latter is a weighted mixture of 1+ floor( n/2) densities with simple forms, equivalently expressed as a product of a power and a Gauss hypergeometric function. The weights are products of factors which depends both on d and n and Bessel numbers independent of d.

Correlation of Meniscal T2* with Multiphoton Microscopy, and Change of Articular Cartilage T2 in an Ovine Model of Meniscal Repair

PubMed Central

Koff, Matthew F.; Shah, Parina; Pownder, Sarah; Romero, Bethsabe; Williams, Rebecca; Gilbert, Susannah; Maher, Suzanne; Fortier, Lisa A.; Rodeo, Scott A.; Potter, Hollis G.

2013-01-01

Objective To correlate meniscal T2* relaxation times using ultra-short echo time (UTE) magnetic resonance imaging (MRI) with quantitative microscopic methods, and to determine the effect of meniscal repair on post-operative cartilage T2 values. Design A medial meniscal tear was created and repaired in the anterior horn of one limb of 28 crossbred mature ewes. MR scans for morphological evaluation, meniscal T2* values, and cartilage T2 values were acquired at 0, 4 and 8 months post-operatively for the Tear and Non-Op limb. Samples of menisci from both limbs were analyzed using multiphoton microscopy (MPM) analysis and biomechanical testing. Results Significantly prolonged meniscal T2* values were found in repaired limbs than in control limbs, p<0.0001. No regional differences of T2* were detected for either the repaired or control limbs in the anterior horn. Repaired limbs had prolonged cartilage T2 values, primarily anteriorly, and tended to have lower biomechanical force to failure at 8 months than Non-Op limbs. MPM autofluorescence and second harmonic generation data correlated with T2* values at 8 months (ρ=−0.48, p=0.06). Conclusions T2* mapping is sensitive to detecting temporal and zonal differences of meniscal structure and composition. Meniscal MPM and cartilage T2 values indicate changes in tissue integrity in the presence of meniscal repair. PMID:23680878

Estimation of the simple correlation coefficient.

PubMed

Shieh, Gwowen

2010-11-01

This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.

Estimation of Rank Correlation for Clustered Data

PubMed Central

Rosner, Bernard; Glynn, Robert

2017-01-01

It is well known that the sample correlation coefficient (Rxy) is the maximum likelihood estimator (MLE) of the Pearson correlation (ρxy) for i.i.d. bivariate normal data. However, this is not true for ophthalmologic data where X (e.g., visual acuity) and Y (e.g., visual field) are available for each eye and there is positive intraclass correlation for both X and Y in fellow eyes. In this paper, we provide a regression-based approach for obtaining the MLE of ρxy for clustered data, which can be implemented using standard mixed effects model software. This method is also extended to allow for estimation of partial correlation by controlling both X and Y for a vector U of other covariates. In addition, these methods can be extended to allow for estimation of rank correlation for clustered data by (a) converting ranks of both X and Y to the probit scale, (b) estimating the Pearson correlation between probit scores for X and Y, and (c) using the relationship between Pearson and rank correlation for bivariate normally distributed data. The validity of the methods in finite-sized samples is supported by simulation studies. Finally, two examples from ophthalmology and analgesic abuse are used to illustrate the methods. PMID:28399615

Viral-mediated overexpression of the Myelin Transcription Factor 1 (MyT1) in the dentate gyrus attenuates anxiety- and ethanol-related behaviors in rats.

PubMed

Bahi, Amine; Dreyer, Jean-Luc

2017-06-01

Myelin Transcription Factor 1 (MyT1), a member of the Zinc Finger gene family, plays a fundamental role in the nervous system. Recent research has suggested that this transcription factor is associated with the pathophysiology of psychiatric disorders including addiction, schizophrenia, and depression. However, the role of MyT1 in anxiety- and ethanol-related behaviors is still unknown. We evaluated the effects of lentiviral-mediated overexpression of MyT1 in the dentate gyrus (DG) on anxiety- and ethanol-related behaviors in rats. We used the elevated plus maze (EPM) and the open field (OF) tests to assess anxiety-like behavior and a two-bottle choice procedure to measure the effects of MyT1 on ethanol intake and preference. MyT1 overexpression produced anxiolytic-like effects in the EPM test and decreased the number of fecal boli in the OF test, without affecting locomotor activity in both behavioral tests. Next, we demonstrated that ethanol intake and preference were decreased in the MyT1-overexpressing rats with no effect on saccharin and quinine, used to assess taste discrimination, and no effect on ethanol clearance suggesting specific alterations in the rewarding effects of ethanol. Most importantly, ectopic MyT1 overexpression increased both MyT1 and BDNF mRNA levels in the DG. Using Pearson's correlation, results showed a strong negative relationship between MyT1 mRNA and anxiety parameters and ethanol consumption and a positive correlation between MyT1 and BDNF mRNAs. Taken together, MyT1 along with being a key component in anxiety may be a suitable candidate in the search of the molecular underpinnings of alcoholism.

Five times sit-to-stand test in subjects with total knee replacement: Reliability and relationship with functional mobility tests.

PubMed

Medina-Mirapeix, Francesc; Vivo-Fernández, Iván; López-Cañizares, Juan; García-Vidal, José A; Benítez-Martínez, Josep Carles; Del Baño-Aledo, María Elena

2018-01-01

The objective was to determine the inter-observer and test/retest reliability of the "Five-repetition sit-to-stand" (5STS) test in patients with total knee replacement (TKR). To explore correlation between 5STS and two mobility tests. A reliability study was conducted among 24 (mean age 72.13, S.D. 10.67; 50% were women) outpatients with TKR. They were recruited from a traumatology unit of a public hospital via convenience sampling. A physiotherapist and trauma physician assessed each patient at the same time. The same physiotherapist realized a 5STS second measurement 45-60min after the first one. Reliability was assessed with intraclass correlation coefficients (ICCs) and Bland-Altman plots. Pearson coefficient was calculated to assess the correlation between 5STS, time up to go test (TUG) and four meters gait speed (4MGS). ICC for inter-observer and test-retest reliability of the 5STS were 0.998 (95% confidence interval [CI], 0.995-0.999) and 0.982 (95% CI, 0.959-0.992). Bland-Altman plot inter-observer showed limits between -0.82 and 1.06 with a mean of 0.11 and no heteroscedasticity within the data. Bland-Altman plot for test-retest showed the limits between 1.76 and 4.16, a mean of 1.20 and heteroscedasticity within the data. Pearson correlation coefficient revealed significant correlation between 5STS and TUG (r=0.7, p<0.001) and 4MGS (r=-0.583, p=0.003). This study demonstrates excellent inter-observer and test-retest reliability when it is used in people with TKR, and also significant correlation with other functional mobility tests. These findings support the use of 5STS as outcome measure in TKR population. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantitative comparison of the absorption spectra of the gas mixtures in analogy to the criterion of Pearson

NASA Astrophysics Data System (ADS)

Kistenev, Yu. V.; Kuzmin, D. A.; Sandykova, E. A.; Shapovalov, A. V.

2015-11-01

An approach to the reduction of the space of the absorption spectra, based on the original criterion for profile analysis of the spectra, was proposed. This criterion dates back to the known statistics chi-square test of Pearson. Introduced criterion allows to quantify the differences of spectral curves.

Correlation between Forced Vital Capacity and Slow Vital Capacity for the assessment of respiratory involvement in Amyotrophic Lateral Sclerosis: a prospective study.

PubMed

Pinto, Susana; de Carvalho, Mamede

2017-02-01

Slow vital capacity (SVC) and forced vital capacity (FVC) are the most frequent used tests evaluating respiratory function in amyotrophic lateral sclerosis (ALS). No previous study has determined their interchangeability. To evaluate SVC-FVC correlation in ALS. Consecutive definite/probable ALS and primary lateral sclerosis (PLS) patients (2000-2014) in whom respiratory tests were performed at baseline/4-6months later were included. All were evaluated with revised ALS functional rating scale, the ALSFRS respiratory (R-subscore) and bulbar subscores, SVC, FVC, maximal inspiratory (MIP) and expiratory (MEP) pressures. SVC-FVC correlation was analysed by Pearson product-moment correlation test. Paired t-test compared baseline/follow-up values. Multilinear regression analysis modelled the relationship between tested variables. We included 592 ALS (332 men, mean onset age 62.6 ± 11.8 years, mean disease duration 15.4 ± 15 months) and 19 PLS (11 men, median age 54 years, median disease duration 5.5 years) patients. SVC and FVC predicted values decreased 2.15%/month and 2.08%/month, respectively. FVC and SVC were strongly correlated. Both were strongly correlated with MIP and MEP and moderately correlated with R-subscore for the all population and spinal-onset patients, but weakly correlated for bulbar-onset patients. FVC and SVC were strongly correlated and declined similarly. This correlation was preserved in bulbar-onset ALS and in spastic PLS patients.

Vibration sensibility testing in the workplace. Day-to-day reliability.

PubMed

Rosecrance, J C; Cook, T M; Satre, D L; Goode, J D; Schroder, M J

1994-09-01

Loss of vibration sensibility has been suggested as an early indicator of peripheral compression neuropathy, including carpal tunnel syndrome. Although vibration sensibility has been used frequently to evaluate carpal tunnel syndrome, the day-to-day reliability of vibration measurements in an industrial population measured at the workplace has not been assessed. Vibration sensibility testing was performed at the university ergonomics laboratory on 50 volunteers (100 hands) and at a newspaper company on 50 workers (100 hands). Vibration perception and disappearance thresholds were measured on two occasions separated by 3 to 5 days. Student's t tests indicated no significant differences between the first and second tests or between the two groups. Pearson product-moment correlations for test-retest reliability were lower in the industry group but were relatively high despite the less than optimal testing conditions. Our findings suggest that vibration sensibility measurements are reliable from day to day not only in the laboratory but also in the workplace.

Correlation between pre-pregnancy body mass index and maternal visceral adiposity with fetal biometry during the second trimester.

PubMed

Lopes, Karina R M; Souza, Alex Sandro R; Figueiroa, José N; Alves, João Guilherme B

2017-08-01

To determine the correlation between pre-pregnancy body mass index (BMI) and maternal visceral adiposity with fetal biometry during the second trimester. A cross-sectional observational study was conducted among pregnant women who received prenatal care at a center in Recife, Brazil, between October 3, 2011, and September 27, 2013. Pre-pregnancy BMI was determined at the first prenatal care visit. Maternal visceral adiposity and fetal biometry were measured at the same ultrasonography session. The associations between maternal and fetal variables were evaluated using the Pearson correlation coefficient (R). The Student t test was used to test the null hypothesis of adjusted correlation coefficients. Overall, 740 women were included. No correlation was found between pre-pregnancy BMI and any of the fetal biometric variables assessed. By contrast, maternal visceral adiposity positively correlated with fetal abdominal circumference (R=0.529), estimated fetal weight (R=0.524), head circumference (R=0.521), femur length (R=0.521), and biparietal diameter (R=0.524; P<0.001 for all fetal variables). These findings remained statistically significant after controlling for pregnancy length. Maternal visceral adiposity, but not pre-pregnancy BMI, positively correlated with fetal biometry during the second trimester. © 2017 International Federation of Gynecology and Obstetrics.

The Pearson-Readhead Survey from Space

NASA Technical Reports Server (NTRS)

Preston, R. A.; Tingay, S. J.; Jones, D. L.; Lister, M.; Piner, G.; Murphy, D. W.; Meier, D. L.; Pearson, T. J.; Readhead, A. C. S.; Hirabayashi, H.;

Expression of MCM-3 and MCM-7 in Primary Cutaneous T-cell Lymphomas.

PubMed

Jankowska-Konsur, Alina; Kobierzycki, Christopher; Reich, Adam; Grzegrzolka, Jedrzej; Maj, Joanna; Dziegiel, Piotr

2015-11-01

Primary cutaneous T-cell lymphomas is a group of rare non-Hodgkin lymphomas, originally affecting the skin. Increased proliferation activity is a hallmark of diverse tumors and the proliferation rate, measured by the expression of various markers has a predictive value regarding the malignancy course. The aim of the present study was to evaluate the prognostic value and the potential correlation between the expression of proliferation markers Ki-67, MCM-3 and MCM-7, and clinicopathological data for different types of primary cutaneous T-cell lymphomas. Immunohistochemical reactions were performed on paraffin blocks obtained from 90 patients with mycosis fungoides (MF) and 21 patients with other CTCL (oCTCL), in comparison to 19 patients with benign inflammatory dermatosis (lichen planus, eczema), serving as control. Statistically significant differences in the expression of Ki-67, MCM-3 and MCM-7 were observed between oCTCL vs. the control group (29% vs. 5%; 17% vs. 5%; 13% vs. 1.5%, respectively, ANOVA with Scheffé post-hoc test: p<0.01). In both, MF and oCTCL Ki-67 expression highly correlated with the expression of MCM-3 (r=0.83; p<0.001 and r=0.91; p<0.001, respectively) and MCM-7 (r=0.84; p<0.001 and r=0.87; p<0.01, respectively; Pearson correlation test). Similarly, a strong positive correlation was observed between MCM-3 and MCM-7 (r=0.81, p<0.001 and r=0.85, p<0.001). Regarding the MF group, Ki-67 and MCM-3 expression was significantly higher in advanced compared to early stages (11% vs. 3% and 15.5% vs. 5.0%, respectively, Student's t-test: p<0.05). Advanced MF had also significantly higher labeling indexes for Ki-67, MCM-3 and MCM-7 compared to benign inflammatory dermatoses (Student's t-test: p<0.01, p<0.001 and p=0.02, respectively). Considering skin involvement in MF, T1b had a significantly higher expression of Ki-67, MCM-3 and MCM-7 than T1a (p<0.001 for all comparisons) with similar observations between T2b and T2a (p=0.02; p<0.01; p=0

Correlation between antimicrobial consumption and antimicrobial resistance of Pseudomonas aeruginosa in a hospital setting: a 10-year study.

PubMed

Mladenovic-Antic, S; Kocic, B; Velickovic-Radovanovic, R; Dinic, M; Petrovic, J; Randjelovic, G; Mitic, R

2016-10-01

Antimicrobial resistance is one of the greatest threats to human health. One of the most important factors leading to the emergence of resistant bacteria is overuse of antibiotics. The purpose of this study was to investigate the correlation between antimicrobial usage and bacterial resistance of Pseudomonas aeruginosa (P. aeruginosa) over a 10-year period in the Clinical Center Niš, one of the biggest tertiary care hospitals in Serbia. We focused on possible relationships between the consumption of carbapenems and beta-lactam antibiotics and the rates of resistance of P. aeruginosa to carbapenems. We recorded utilization of antibiotics expressed as defined daily doses per 100 bed days (DBD). Bacterial resistance was reported as the percentage of resistant isolates (percentage of all resistant and intermediate resistant strains) among all tested isolates. A significant increasing trend in resistance was seen in imipenem (P < 0·05, Spearman ρ = 0·758) and meropenem (P < 0·05, ρ = 0·745). We found a significant correlation between aminoglycoside consumption and resistance to amikacin (P < 0·01, Pearson r = 0·837) and gentamicin (P < 0·01, Pearson r = 0·827). The correlation between the consumption of carbapenems and resistance to imipenem in P. aeruginosa shows significance (P < 0·01, Pearson r = 0·795), whereas resistance to meropenem showed a trend towards significance (P > 0·05, Pearson r = 0·607). We found a very good correlation between the use of all beta-lactam and P. aeruginosa resistance to carbapenems (P < 0·01, Pearson r = 0·847 for imipenem and P < 0·05, Pearson r = 0·668 for meropenem). Our data demonstrated a significant increase in antimicrobial resistance to carbapenems, significant correlations between the consumption of antibiotics, especially carbapenems and beta-lactams, and rates of antimicrobial resistance of P. aeruginosa to imipenem and meropenem. © 2016 John Wiley & Sons Ltd.

Fast computation of voxel-level brain connectivity maps from resting-state functional MRI using l₁-norm as approximation of Pearson's temporal correlation: proof-of-concept and example vector hardware implementation.

PubMed

Minati, Ludovico; Zacà, Domenico; D'Incerti, Ludovico; Jovicich, Jorge

2014-09-01

An outstanding issue in graph-based analysis of resting-state functional MRI is choice of network nodes. Individual consideration of entire brain voxels may represent a less biased approach than parcellating the cortex according to pre-determined atlases, but entails establishing connectedness for 1(9)-1(11) links, with often prohibitive computational cost. Using a representative Human Connectome Project dataset, we show that, following appropriate time-series normalization, it may be possible to accelerate connectivity determination replacing Pearson correlation with l1-norm. Even though the adjacency matrices derived from correlation coefficients and l1-norms are not identical, their similarity is high. Further, we describe and provide in full an example vector hardware implementation of l1-norm on an array of 4096 zero instruction-set processors. Calculation times <1000 s are attainable, removing the major deterrent to voxel-based resting-sate network mapping and revealing fine-grained node degree heterogeneity. L1-norm should be given consideration as a substitute for correlation in very high-density resting-state functional connectivity analyses. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

The changes in the T-lymphocyte subsets in a population of Turkish children with puberty gingivitis.

PubMed

Demir, Turgut; Orbak, Recep; Tezel, Adnan; Canakç, Varol; Kaya, Hasan

2009-05-01

The aim of the study was to investigate the number of CD4 and CD8 T lymphocytes, analyse subjects with gingivitis and those without, and determine the role of T lymphocytes in the pathobiology of puberty gingivitis. Fifty individuals with and without puberty gingivitis were recruited for this study. The CD4(+) and CD8(+) T-lymphocyte counts were determined using flow cytometry on the biopsy samples, and the CD4(+)/CD8(+) ratio was calculated. At the same time, periodontal index scores were recorded to assess the periodontal status. Acquired data were analysed statistically using a paired t-test to compare laboratory values obtained before and after the treatment in individuals with puberty gingivitis and disease-free individuals. In addition, Pearson's correlation analysis was performed to investigate the relation between laboratory values and clinical measurements. The CD4(+)/CD8 ratio in gingival tissues obtained from test group was significantly higher (P < 0.05) than that found in the gingival tissue obtained from control group. We found that the CD4(+) and CD8(+) lymphocyte counts continued to increase significantly (P < 0.001) and the CD4(+)/CD8(+) ratio continued to drop significantly (P < 0.05) after treatment in test group. T lymphocytes could play a significant role in the pathobiology of puberty gingivitis.

Reducing Bias and Error in the Correlation Coefficient Due to Nonnormality

ERIC Educational Resources Information Center

Bishara, Anthony J.; Hittner, James B.

2015-01-01

It is more common for educational and psychological data to be nonnormal than to be approximately normal. This tendency may lead to bias and error in point estimates of the Pearson correlation coefficient. In a series of Monte Carlo simulations, the Pearson correlation was examined under conditions of normal and nonnormal data, and it was compared…

Effect of degree correlations above the first shell on the percolation transition

NASA Astrophysics Data System (ADS)

Valdez, L. D.; Buono, C.; Braunstein, L. A.; Macri, P. A.

2011-11-01

The use of degree-degree correlations to model realistic networks which are characterized by their Pearson's coefficient, has become widespread. However the effect on how different correlation algorithms produce different results on processes on top of them, has not yet been discussed. In this letter, using different correlation algorithms to generate assortative networks, we show that for very assortative networks the behavior of the main observables in percolation processes depends on the algorithm used to build the network. The different alghoritms used here introduce different inner structures that are missed in Pearson's coefficient. We explain the different behaviors through a generalization of Pearson's coefficient that allows to study the correlations at chemical distances l from a root node. We apply our findings to real networks.

Clustering stocks using partial correlation coefficients

NASA Astrophysics Data System (ADS)

Jung, Sean S.; Chang, Woojin

2016-11-01

A partial correlation analysis is performed on the Korean stock market (KOSPI). The difference between Pearson correlation and the partial correlation is analyzed and it is found that when conditioned on the market return, Pearson correlation coefficients are generally greater than those of the partial correlation, which implies that the market return tends to drive up the correlation between stock returns. A clustering analysis is then performed to study the market structure given by the partial correlation analysis and the members of the clusters are compared with the Global Industry Classification Standard (GICS). The initial hypothesis is that the firms in the same GICS sector are clustered together since they are in a similar business and environment. However, the result is inconsistent with the hypothesis and most clusters are a mix of multiple sectors suggesting that the traditional approach of using sectors to determine the proximity between stocks may not be sufficient enough to diversify a portfolio.

Estimation of rank correlation for clustered data.

PubMed

Rosner, Bernard; Glynn, Robert J

2017-06-30

It is well known that the sample correlation coefficient (R xy ) is the maximum likelihood estimator of the Pearson correlation (ρ xy ) for independent and identically distributed (i.i.d.) bivariate normal data. However, this is not true for ophthalmologic data where X (e.g., visual acuity) and Y (e.g., visual field) are available for each eye and there is positive intraclass correlation for both X and Y in fellow eyes. In this paper, we provide a regression-based approach for obtaining the maximum likelihood estimator of ρ xy for clustered data, which can be implemented using standard mixed effects model software. This method is also extended to allow for estimation of partial correlation by controlling both X and Y for a vector U_ of other covariates. In addition, these methods can be extended to allow for estimation of rank correlation for clustered data by (i) converting ranks of both X and Y to the probit scale, (ii) estimating the Pearson correlation between probit scores for X and Y, and (iii) using the relationship between Pearson and rank correlation for bivariate normally distributed data. The validity of the methods in finite-sized samples is supported by simulation studies. Finally, two examples from ophthalmology and analgesic abuse are used to illustrate the methods. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

3. Historic American Buildings Survey, Elmer R. Pearson, Photographer, 1968 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Historic American Buildings Survey, Elmer R. Pearson, Photographer, 1968 ELEVATION, LOOKING NORTHWEST. - Shaker Centre Family, Broom Shop, East side of Oxford Road, White Water Park, Hamilton County, OH

Distance correlation methods for discovering associations in large astrophysical databases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez-Gómez, Elizabeth; Richards, Mercedes T.; Richards, Donald St. P., E-mail: elizabeth.martinez@itam.mx, E-mail: mrichards@astro.psu.edu, E-mail: richards@stat.psu.edu

2014-01-20

High-dimensional, large-sample astrophysical databases of galaxy clusters, such as the Chandra Deep Field South COMBO-17 database, provide measurements on many variables for thousands of galaxies and a range of redshifts. Current understanding of galaxy formation and evolution rests sensitively on relationships between different astrophysical variables; hence an ability to detect and verify associations or correlations between variables is important in astrophysical research. In this paper, we apply a recently defined statistical measure called the distance correlation coefficient, which can be used to identify new associations and correlations between astrophysical variables. The distance correlation coefficient applies to variables of any dimension,more » can be used to determine smaller sets of variables that provide equivalent astrophysical information, is zero only when variables are independent, and is capable of detecting nonlinear associations that are undetectable by the classical Pearson correlation coefficient. Hence, the distance correlation coefficient provides more information than the Pearson coefficient. We analyze numerous pairs of variables in the COMBO-17 database with the distance correlation method and with the maximal information coefficient. We show that the Pearson coefficient can be estimated with higher accuracy from the corresponding distance correlation coefficient than from the maximal information coefficient. For given values of the Pearson coefficient, the distance correlation method has a greater ability than the maximal information coefficient to resolve astrophysical data into highly concentrated horseshoe- or V-shapes, which enhances classification and pattern identification. These results are observed over a range of redshifts beyond the local universe and for galaxies from elliptical to spiral.« less

Optimization of the two-sample rank Neyman-Pearson detector

NASA Astrophysics Data System (ADS)

Akimov, P. S.; Barashkov, V. M.

1984-10-01

The development of optimal algorithms concerned with rank considerations in the case of finite sample sizes involves considerable mathematical difficulties. The present investigation provides results related to the design and the analysis of an optimal rank detector based on a utilization of the Neyman-Pearson criteria. The detection of a signal in the presence of background noise is considered, taking into account n observations (readings) x1, x2, ... xn in the experimental communications channel. The computation of the value of the rank of an observation is calculated on the basis of relations between x and the variable y, representing interference. Attention is given to conditions in the absence of a signal, the probability of the detection of an arriving signal, details regarding the utilization of the Neyman-Pearson criteria, the scheme of an optimal rank, multichannel, incoherent detector, and an analysis of the detector.

Complementarity and Correlations

NASA Astrophysics Data System (ADS)

Maccone, Lorenzo; Bruß, Dagmar; Macchiavello, Chiara

2015-04-01

We provide an interpretation of entanglement based on classical correlations between measurement outcomes of complementary properties: States that have correlations beyond a certain threshold are entangled. The reverse is not true, however. We also show that, surprisingly, all separable nonclassical states exhibit smaller correlations for complementary observables than some strictly classical states. We use mutual information as a measure of classical correlations, but we conjecture that the first result holds also for other measures (e.g., the Pearson correlation coefficient or the sum of conditional probabilities).

Reliability and Validity of a New Test of Agility and Skill for Female Amateur Soccer Players

PubMed Central

Kutlu, Mehmet; Yapici, Hakan; Yilmaz, Abdullah

2017-01-01

Abstract The aim of this study was to evaluate the Agility and Skill Test, which had been recently developed to assess agility and skill in female athletes. Following a 10 min warm-up, two trials to test the reliability and validity of the test were conducted one week apart. Measurements were collected to compare soccer players’ physical performance in a 20 m sprint, a T-Drill test, the Illinois Agility Run Test, change-of-direction and acceleration, as well as agility and skill. All tests were completed following the same order. Thirty-four amateur female soccer players were recruited (age = 20.8 ± 1.9 years; body height = 166 ± 6.9 cm; body mass = 55.5 ± 5.8 kg). To determine the reliability and usefulness of these tests, paired sample t-tests, intra-class correlation coefficients, typical error, coefficient of variation, and differences between the typical error and smallest worthwhile change statistics were computed. Test results showed no significant differences between the two sessions (p > 0.01). There were higher intra-class correlations between the test and retest values (r = 0.94–0.99) for all tests. Typical error values were below the smallest worthwhile change, indicating ‘good’ usefulness for these tests. A near perfect Pearson correlation between the Agility and Skill Test (r = 0.98) was found, and there were moderate-to-large levels of correlation between the Agility and Skill Test and other measures (r = 0.37 to r = 0.56). The results of this study suggest that the Agility and Skill Test is a reliable and valid test for female soccer players and has significant value for assessing the integrative agility and skill capability of soccer players. PMID:28469760

Commercialising Comparison: Pearson Puts the TLC in Soft Capitalism

ERIC Educational Resources Information Center

Hogan, Anna; Sellar, Sam; Lingard, Bob

2016-01-01

This paper provides a critical policy analysis of "The Learning Curve" (TLC) (2012), an initiative developed by the multinational edu-business, Pearson, in conjunction with the Economist Intelligence Unit. "TLC" exemplifies the commercialising of comparison and the efforts of edu-businesses to strategically position themselves…

Correlation between spermatogenesis disorders and rat testes CYP2E1 mRNA contents under experimental alcoholism or type I diabetes.

PubMed

Shayakhmetova, Ganna M; Bondarenko, Larysa B; Matvienko, Anatoliy V; Kovalenko, Valentina M

2014-09-01

The aim of the study was to investigate the correlation between spermatogenesis disorders and CYP2E1 mRNA contents in testes of rats with experimental alcoholism or type I diabetes. Two pathological states characterized by CYP2E1 induction were simulated on Wistar male rats: experimental alcoholism and type I diabetes. As controls for each state, equal number of animals (of the same age and weight) were used. Morphological evaluation of rat testes was carried out. The spermatogenic epithelium state was estimated by four points system. CYP2E1 mRNA expression was rated by method of reverse transcriptase polymerase chain reaction. Pearson correlation coefficients were used for describing relationships between variables. The presence of alcoholism and diabetes-mediated quantitative and qualitative changes in male rat spermatogenic epithelium in comparison with norm has been demonstrated. The increased levels of testes CYP2E1 have been fixed simultaneously. CYP2E1 mRNA content negatively strongly correlated with spermatogenic index value (r=-0.99; P<0.001) and positively strongly correlated with epithelium desquamation occurrence (r=0.99; P<0.001) in testes of rats with chronic alcoholism. The strong correlation between CYP2E1 mRNA content and number of spermatogonia (r=0.99; P<0.001) and "windows" occurrence (r=0.96; P<0.001) has been fixed in diabetic rats testes. Present investigation has demonstrated that the testicular failure following chronic ethanol consumption and diabetes type I in male rats accompanied CYP2E1 mRNA over-expression in testes. The correlation between the levels of CYP2E1 mRNA in testes and spermatogenesis disorders allow supposing the involvement of CYP2E1 into the non-specific pathogenetic mechanisms of male infertility under above-mentioned pathologies. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Entanglement-enhanced Neyman-Pearson target detection using quantum illumination

NASA Astrophysics Data System (ADS)

Zhuang, Quntao; Zhang, Zheshen; Shapiro, Jeffrey H.

2017-08-01

Quantum illumination (QI) provides entanglement-based target detection---in an entanglement-breaking environment---whose performance is significantly better than that of optimum classical-illumination target detection. QI's performance advantage was established in a Bayesian setting with the target presumed equally likely to be absent or present and error probability employed as the performance metric. Radar theory, however, eschews that Bayesian approach, preferring the Neyman-Pearson performance criterion to avoid the difficulties of accurately assigning prior probabilities to target absence and presence and appropriate costs to false-alarm and miss errors. We have recently reported an architecture---based on sum-frequency generation (SFG) and feedforward (FF) processing---for minimum error-probability QI target detection with arbitrary prior probabilities for target absence and presence. In this paper, we use our results for FF-SFG reception to determine the receiver operating characteristic---detection probability versus false-alarm probability---for optimum QI target detection under the Neyman-Pearson criterion.

[Transcultural adaptation of the Antifat Attitudes Test to Brazilian Portuguese].

PubMed

Obara, Angélica Almeida; Alvarenga, Marle Dos Santos

2018-05-01

Obese individuals are often blamed for their own condition and the targets of discrimination and prejudice. The scope of this study is to describe the cross-cultural adaptation to Brazilian Portuguese and the validation of the Antifat Attitudes Test - specifically developed for evaluation of negative attitudes toward the obese individual. The scale has 34 statements distributed in three subscales - Social/Character Disparagement (15 items), Physical/Romantic Unattractiveness (10 items) and Weight Control/Blame (9 items). The method involved the translation of the scale; evaluation of the conceptual, operational and item equivalence; evaluation of the semantic equivalence using the paired t test, the Pearson correlation coefficient and the intraclass correlation coefficient (ICC); internal consistency evaluation (Cronbach's alpha) and test-retest reliability (ICC) and Confirmatory Factor Analysis - after application in 340 college students in the area of health. The results showed good global internal consistency and reliability (α 0.85; CCI 0.83), and factor analysis showed that the original subscales can be kept in the adaptation, and therefore the scale adapted to the Brazilian-Portuguese version is valid and useful in studies to explore negative attitudes toward obese individuals.

Global-in-time solutions for the isothermal Matovich-Pearson equations

NASA Astrophysics Data System (ADS)

Feireisl, Eduard; Laurençot, Philippe; Mikelić, Andro

2011-01-01

In this paper we study the Matovich-Pearson equations describing the process of glass fibre drawing. These equations may be viewed as a 1D-reduction of the incompressible Navier-Stokes equations including free boundary, valid for the drawing of a long and thin glass fibre. We concentrate on the isothermal case without surface tension. Then the Matovich-Pearson equations represent a nonlinearly coupled system of an elliptic equation for the axial velocity and a hyperbolic transport equation for the fluid cross-sectional area. We first prove existence of a local solution, and, after constructing appropriate barrier functions, we deduce that the fluid radius is always strictly positive and that the local solution remains in the same regularity class. This estimate leads to the global existence and uniqueness result for this important system of equations.

31. Historic American Buildings Survey E. R. Pearson, Photographer 1972 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. Historic American Buildings Survey E. R. Pearson, Photographer 1972 CLOTHES ROOM, FIRST ATTIC, SOUTHEAST CORNER, LOOKING EAST - Shaker Centre Family Dwelling House, West side of U.S. Route 68, South Union, Logan County, KY

Global and Local Partitioning of the Charge Transferred in the Parr-Pearson Model.

PubMed

Orozco-Valencia, Angel Ulises; Gázquez, José L; Vela, Alberto

2017-05-25

Through a simple proposal, the charge transfer obtained from the cornerstone theory of Parr and Pearson is partitioned, for each reactant, in two channels: an electrophilic, through which the species accepts electrons, and the other, a nucleophilic, where the species donates electrons. It is shown that this global model allows us to determine unambiguously the charge-transfer mechanism prevailing in a given reaction. The partitioning is extended to include local effects through the Fukui functions of the reactants. This local model is applied to several emblematic reactions in organic and inorganic chemistry, and we show that besides improving the correlations obtained with the global model it provides valuable information concerning the atoms in the reactants playing the most important roles in the reaction and thus improving our understanding of the reaction under study.

Reducing Bias and Error in the Correlation Coefficient Due to Nonnormality.

PubMed

Bishara, Anthony J; Hittner, James B

2015-10-01

It is more common for educational and psychological data to be nonnormal than to be approximately normal. This tendency may lead to bias and error in point estimates of the Pearson correlation coefficient. In a series of Monte Carlo simulations, the Pearson correlation was examined under conditions of normal and nonnormal data, and it was compared with its major alternatives, including the Spearman rank-order correlation, the bootstrap estimate, the Box-Cox transformation family, and a general normalizing transformation (i.e., rankit), as well as to various bias adjustments. Nonnormality caused the correlation coefficient to be inflated by up to +.14, particularly when the nonnormality involved heavy-tailed distributions. Traditional bias adjustments worsened this problem, further inflating the estimate. The Spearman and rankit correlations eliminated this inflation and provided conservative estimates. Rankit also minimized random error for most sample sizes, except for the smallest samples ( n = 10), where bootstrapping was more effective. Overall, results justify the use of carefully chosen alternatives to the Pearson correlation when normality is violated.

Reducing Bias and Error in the Correlation Coefficient Due to Nonnormality

PubMed Central

Hittner, James B.

2014-01-01

It is more common for educational and psychological data to be nonnormal than to be approximately normal. This tendency may lead to bias and error in point estimates of the Pearson correlation coefficient. In a series of Monte Carlo simulations, the Pearson correlation was examined under conditions of normal and nonnormal data, and it was compared with its major alternatives, including the Spearman rank-order correlation, the bootstrap estimate, the Box–Cox transformation family, and a general normalizing transformation (i.e., rankit), as well as to various bias adjustments. Nonnormality caused the correlation coefficient to be inflated by up to +.14, particularly when the nonnormality involved heavy-tailed distributions. Traditional bias adjustments worsened this problem, further inflating the estimate. The Spearman and rankit correlations eliminated this inflation and provided conservative estimates. Rankit also minimized random error for most sample sizes, except for the smallest samples (n = 10), where bootstrapping was more effective. Overall, results justify the use of carefully chosen alternatives to the Pearson correlation when normality is violated. PMID:29795841

A closer look at the effect of preliminary goodness-of-fit testing for normality for the one-sample t-test.

PubMed

Rochon, Justine; Kieser, Meinhard

2011-11-01

Student's one-sample t-test is a commonly used method when inference about the population mean is made. As advocated in textbooks and articles, the assumption of normality is often checked by a preliminary goodness-of-fit (GOF) test. In a paper recently published by Schucany and Ng it was shown that, for the uniform distribution, screening of samples by a pretest for normality leads to a more conservative conditional Type I error rate than application of the one-sample t-test without preliminary GOF test. In contrast, for the exponential distribution, the conditional level is even more elevated than the Type I error rate of the t-test without pretest. We examine the reasons behind these characteristics. In a simulation study, samples drawn from the exponential, lognormal, uniform, Student's t-distribution with 2 degrees of freedom (t(2) ) and the standard normal distribution that had passed normality screening, as well as the ingredients of the test statistics calculated from these samples, are investigated. For non-normal distributions, we found that preliminary testing for normality may change the distribution of means and standard deviations of the selected samples as well as the correlation between them (if the underlying distribution is non-symmetric), thus leading to altered distributions of the resulting test statistics. It is shown that for skewed distributions the excess in Type I error rate may be even more pronounced when testing one-sided hypotheses. ©2010 The British Psychological Society.

mtDNA Deletion in an Iranian Infant with Pearson Marrow Syndrome.

PubMed

Arzanian, Mohammad Taghi; Eghbali, Aziz; Karimzade, Parvaneh; Ahmadi, Mitra; Houshmand, Massoud; Rezaei, Nima

2010-03-01

Pearson syndrome (PS) is a rare multisystem mitochondrial disorder of hematopoietic system, characterized by refractory sideroblastic anemia, pancytopenia, exocrine pancreatic insufficiency, and variable neurologic, hepatic, renal, and endocrine failure. We describe a six-month-old female infant with Pearson marrow syndrome who presented with neurological manifestations. She had several episodes of seizures. Hematopoietic abnormalities were macrocytic anemia and neutropenia. Bone marrow aspiration revealed a cellular marrow with marked vacuolization of erythroid and myeloid precursors. Analysis of mtDNA in peripheral blood showed 8.5 kb deletion that was compatible with the diagnosis of PS. PS should be considered in infants with neurologic diseases, in patients with cytopenias, and also in patients with acidosis or refractory anemia.

Clock drawing test in elderly individuals with different education levels: correlation with clinical dementia rating.

PubMed

Cecato, Juliana Francisca; Fiorese, Bruna; Montiel, José Maria; Bartholomeu, Daniel; Martinelli, José Eduardo

2012-12-01

The aim of this study was to describe the performance in Clock Drawing Test (CDT) of the elderly individuals assessed in a geriatric clinic, with at least 1 year of schooling, comparing with other groups with higher education and with Clinical Dementia Rating (CDR) levels. The study also aims to correlate the results of CDT and other used diagnostic tests for dementia by CDR levels, providing additional validity evidence to the CDT. Cross-sectional study with 426 elderly individuals, >60 years old and at least 1 year of education. All participants searched for medical assistance at Geriatric and Gerontology Ambulatory of Jundiaí city, in Brazil. The community-dwelling outpatients previously undergone a detailed clinical examination and neuropsychological evaluation: Cambrigde Cognitive Examination (CAMCOG), Mini-Mental State Examination (MMSE), andCDT. To differentiate data from diagnostic groups based on CDR, it Kruskal-Wallis test was used. Pearson statistics were calculated to compare data from CDT and CDR. The statistical analyses were 2-tailed and were considered significant when P < .05. Regarding CDT, groups with more years of schooling showed similar means in CDR = 0 and CDR = 0.5 and in CDR = 1 and CDR = 2. Shulman and Sunderland scale were high score in groups with more years of education and above of cutoff points in all CDT score. On the contrary, in Mendez scale we did not observed similar means. Otherwise, in the group with less years of schooling greater means differences in the CDT were observed. The CDT did not show a strong correlation with MMSE and CAMCOG, both important instruments in Brazilian population to investigate dementia. For elderly individuals with high education levels, the CDT did not seem to be a good test to detect cognitive impairment.

Clopper-Pearson bounds from HEP data cuts

NASA Astrophysics Data System (ADS)

Berg, B. A.

2001-08-01

For the measurement of Ns signals in N events rigorous confidence bounds on the true signal probability pexact were established in a classical paper by Clopper and Pearson [Biometrica 26, 404 (1934)]. Here, their bounds are generalized to the HEP situation where cuts on the data tag signals with probability Ps and background data with likelihood Pb

Hypothesis testing for differentially correlated features.

PubMed

Sheng, Elisa; Witten, Daniela; Zhou, Xiao-Hua

2016-10-01

In a multivariate setting, we consider the task of identifying features whose correlations with the other features differ across conditions. Such correlation shifts may occur independently of mean shifts, or differences in the means of the individual features across conditions. Previous approaches for detecting correlation shifts consider features simultaneously, by computing a correlation-based test statistic for each feature. However, since correlations involve two features, such approaches do not lend themselves to identifying which feature is the culprit. In this article, we instead consider a serial testing approach, by comparing columns of the sample correlation matrix across two conditions, and removing one feature at a time. Our method provides a novel perspective and favorable empirical results compared with competing approaches. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The Toxicity Estimation Software Tool (T.E.S.T.)

EPA Science Inventory

The Toxicity Estimation Software Tool (T.E.S.T.) has been developed to estimate toxicological values for aquatic and mammalian species considering acute and chronic endpoints for screening purposes within TSCA and REACH programs.

Object aggregation using Neyman-Pearson analysis

NASA Astrophysics Data System (ADS)

Bai, Li; Hinman, Michael L.

2003-04-01

This paper presents a novel approach to: 1) distinguish military vehicle groups, and 2) identify names of military vehicle convoys in the level-2 fusion process. The data is generated from a generic Ground Moving Target Indication (GMTI) simulator that utilizes Matlab and Microsoft Access. This data is processed to identify the convoys and number of vehicles in the convoy, using the minimum timed distance variance (MTDV) measurement. Once the vehicle groups are formed, convoy association is done using hypothesis techniques based upon Neyman Pearson (NP) criterion. One characteristic of NP is the low error probability when a-priori information is unknown. The NP approach was demonstrated with this advantage over a Bayesian technique.

Effects of different correlation metrics and preprocessing factors on small-world brain functional networks: a resting-state functional MRI study.

PubMed

Liang, Xia; Wang, Jinhui; Yan, Chaogan; Shu, Ni; Xu, Ke; Gong, Gaolang; He, Yong

2012-01-01

Graph theoretical analysis of brain networks based on resting-state functional MRI (R-fMRI) has attracted a great deal of attention in recent years. These analyses often involve the selection of correlation metrics and specific preprocessing steps. However, the influence of these factors on the topological properties of functional brain networks has not been systematically examined. Here, we investigated the influences of correlation metric choice (Pearson's correlation versus partial correlation), global signal presence (regressed or not) and frequency band selection [slow-5 (0.01-0.027 Hz) versus slow-4 (0.027-0.073 Hz)] on the topological properties of both binary and weighted brain networks derived from them, and we employed test-retest (TRT) analyses for further guidance on how to choose the "best" network modeling strategy from the reliability perspective. Our results show significant differences in global network metrics associated with both correlation metrics and global signals. Analysis of nodal degree revealed differing hub distributions for brain networks derived from Pearson's correlation versus partial correlation. TRT analysis revealed that the reliability of both global and local topological properties are modulated by correlation metrics and the global signal, with the highest reliability observed for Pearson's-correlation-based brain networks without global signal removal (WOGR-PEAR). The nodal reliability exhibited a spatially heterogeneous distribution wherein regions in association and limbic/paralimbic cortices showed moderate TRT reliability in Pearson's-correlation-based brain networks. Moreover, we found that there were significant frequency-related differences in topological properties of WOGR-PEAR networks, and brain networks derived in the 0.027-0.073 Hz band exhibited greater reliability than those in the 0.01-0.027 Hz band. Taken together, our results provide direct evidence regarding the influences of correlation metrics and specific

Effects of Different Correlation Metrics and Preprocessing Factors on Small-World Brain Functional Networks: A Resting-State Functional MRI Study

PubMed Central

Liang, Xia; Wang, Jinhui; Yan, Chaogan; Shu, Ni; Xu, Ke; Gong, Gaolang; He, Yong

2012-01-01

Graph theoretical analysis of brain networks based on resting-state functional MRI (R-fMRI) has attracted a great deal of attention in recent years. These analyses often involve the selection of correlation metrics and specific preprocessing steps. However, the influence of these factors on the topological properties of functional brain networks has not been systematically examined. Here, we investigated the influences of correlation metric choice (Pearson's correlation versus partial correlation), global signal presence (regressed or not) and frequency band selection [slow-5 (0.01–0.027 Hz) versus slow-4 (0.027–0.073 Hz)] on the topological properties of both binary and weighted brain networks derived from them, and we employed test-retest (TRT) analyses for further guidance on how to choose the “best” network modeling strategy from the reliability perspective. Our results show significant differences in global network metrics associated with both correlation metrics and global signals. Analysis of nodal degree revealed differing hub distributions for brain networks derived from Pearson's correlation versus partial correlation. TRT analysis revealed that the reliability of both global and local topological properties are modulated by correlation metrics and the global signal, with the highest reliability observed for Pearson's-correlation-based brain networks without global signal removal (WOGR-PEAR). The nodal reliability exhibited a spatially heterogeneous distribution wherein regions in association and limbic/paralimbic cortices showed moderate TRT reliability in Pearson's-correlation-based brain networks. Moreover, we found that there were significant frequency-related differences in topological properties of WOGR-PEAR networks, and brain networks derived in the 0.027–0.073 Hz band exhibited greater reliability than those in the 0.01–0.027 Hz band. Taken together, our results provide direct evidence regarding the influences of correlation metrics

The application of soccer performance testing protocols to the non-elite player.

PubMed

Siegler, J; Robergs, R; Weingart, H

2006-03-01

The application of performance testing for the evaluation of non-elite soccer players has received little attention. The purpose of this investigation was to use tests developed for elite soccer players to evaluate performance in non-elite soccer players and compare performance test results between elite (literature) and non-elite (data) players. Thirteen male soccer players volunteered to participate. The tests included a treadmill VO2max test, 20 m sprint, vertical jump (VJ), 30 s Wingate cycle ergometer test, the Loughborough Intermittent Shuttle Test (LIST), and 2 20-m multi-stage shuttle runs to exhaustion (fatigue test). Actual VO2max (absolute and relative) scores were correlated with the estimated VO2max scores (fatigue test), 20 m sprint, VJ, and 30 s Wingate using a Pearson's product-moment correlation. A paired t-test was conducted on the fatigue test trials. Non-significant relationships were observed between actual VO2max scores and estimated VO2max from the fatigue test (absolute and relative terms). Non-significant relationships were also observed between peak and average power output (Wingate), 20 m sprint, and VJ. Mean heart rates (HRs) throughout the LIST was 165+/-7 bpm, which represented 88% of HRmax. The results of this study demonstrate that to elicit physiological differences between elite and non-elite players, assessment must include both an aerobic and anaerobic component.

Relationship Between T1 Slope and Cervical Alignment Following Multilevel Posterior Cervical Fusion Surgery: Impact of T1 Slope Minus Cervical Lordosis.

PubMed

Hyun, Seung-Jae; Kim, Ki-Jeong; Jahng, Tae-Ahn; Kim, Hyun-Jib

2016-04-01

Retrospective study. To assess the relationship between sagittal alignment of the cervical spine and patient-reported health-related quality-of-life scores following multilevel posterior cervical fusion, and to explore whether an analogous relationship exists in the cervical spine using T1 slope minus C2-C7 lordosis (T1S-CL). A recent study demonstrated that, similar to the thoracolumbar spine, the severity of disability increases with sagittal malalignment following cervical reconstruction surgery. From 2007 to 2013, 38 consecutive patients underwent multilevel posterior cervical fusion for cervical stenosis, myelopathy, and deformities. Radiographic measurements included C0-C2 lordosis, C2-C7 lordosis, C2-C7 sagittal vertical axis (SVA), T1 slope, and T1S-CL. Pearson correlation coefficients were calculated between pairs of radiographic measures and health-related quality-of-life. C2-C7 SVA positively correlated with neck disability index (NDI) scores (r = 0.495). C2-C7 lordosis (P = 0.001) and T1S-CL (P = 0.002) changes correlated with NDI score changes after surgery. For significant correlations between C2-C7 SVA and NDI scores, regression models predicted a threshold C2-C7 SVA value of 50 mm, beyond which correlations were most significant. The T1S-CL also correlated positively with C2-C7 SVA and NDI scores (r = 0.871 and r = 0.470, respectively). Results of the regression analysis indicated that a C2-C7 SVA value of 50 mm corresponded to a T1S-CL value of 26.1°. This study showed that disability of the neck increased with cervical sagittal malalignment following surgical reconstruction and a greater T1S-CL mismatch was associated with a greater degree of cervical malalignment. Specifically, a mismatch greater than 26.1° corresponded to positive cervical sagittal malalignment, defined as C2-C7 SVA greater than 50 mm. 3.

Does endothelial cell density correlate with corneal diameter in a group of young adults?

PubMed

Giasson, Claude J; Gosselin, Lucie; Masella, Aviva; Forcier, Pierre

2008-07-01

In children, but not in the elderly, an association exists between corneal diameter and endothelial cell density (ECD). We tested whether such an association also held true in young adults. The eyes of 35 healthy subjects (mean age, 23.1 +/- 3.1 years) were photographed by using a video camera and a noncontact endothelial microscope. Both sets of images were analyzed with image software and the contour method to measure corneal diameter, ECD, and endothelial coefficients. Axial lengths, refractive errors, and corneal curvatures were measured by using an A-scan ultrasonic biometer and kerato-refractometer. Measurements, averaged for the right and left eyes, were analyzed depending on (1) use of contact lenses, (2) ametropia, and on whether (3) axial length or (4) corneal diameter was above or below group means. Differences were tested for statistical significance with independent t tests and association with the Pearson correlation coefficient. ECD, corneal diameter, and spherical equivalent refraction were 3022 +/- 262 cells/mm2, 12.0 +/- 0.5 mm, and -3.1 +/- 2.5 D, respectively. The only significant differences between wearers and nonwearers of contact lenses were the spherical refractive equivalent and axial length. There was no correlation between ECD and corneal diameter or axial length. As opposed to previously reported results in children, but as found in the elderly, there is no correlation between ECD and corneal diameter in young adults. Therefore, corneal size cannot be considered a determinant of ECD in young adults.

Using a Nonparametric Bootstrap to Obtain a Confidence Interval for Pearson's "r" with Cluster Randomized Data: A Case Study

ERIC Educational Resources Information Center

Wagstaff, David A.; Elek, Elvira; Kulis, Stephen; Marsiglia, Flavio

2009-01-01

A nonparametric bootstrap was used to obtain an interval estimate of Pearson's "r," and test the null hypothesis that there was no association between 5th grade students' positive substance use expectancies and their intentions to not use substances. The students were participating in a substance use prevention program in which the unit of…

Correlation between Serum Uric Acid Level and Microalbuminuria in Type-2 Diabetic Nephropathy

PubMed Central

Latif, Hina; Iqbal, Adil; Rathore, Rabia; Butt, Nasir Farooq

2017-01-01

Objective: To measure the correlation between microalbuminuria and serum uric acid level in Type-2 diabetic nephropathy. Methods: This cross-sectional study was done in department of Medicine, Mayo hospital Lahore from August 2014 to February 2015. A total of 200 patients with Type-2 diabetic nephropathy were enrolled in the study. Demographic data and contact details were obtained. Serum Uric acid and microalbuminuria by albumin to creatinine ratio (ACR) in random urine sample was measured at the time of inclusion of patients. All the information was collected through a pre-defined proforma. Pearson correlation coefficient and t-test were used to assess correlation and significance respectively. Results: Out of 200 cases, 29%(n=58) were between 16-40 years of age while 71%(n=142) were between 41-65 years of age, Mean ± SD was calculated as 48.1±10.26 years, 48.5%(n=97) were male and 51.5%(n=103) were females, Mean serum uric acid level was calculated as 6.99±1.01 mg/dL while microalbuminuria was calculated as 5.63±1.08 mg/mmol, r value was 0.0838 which is a positive correlation. Conclusion: The results of our study concluded that level of serum uric acid and microalbuminuria are significantly correlated to nephropathy in patients having Type-2 diabetes mellitus. PMID:29492061

Combining Correlation Matrices: Simulation Analysis of Improved Fixed-Effects Methods

ERIC Educational Resources Information Center

Hafdahl, Adam R.

2007-01-01

The originally proposed multivariate meta-analysis approach for correlation matrices--analyze Pearson correlations, with each study's observed correlations replacing their population counterparts in its conditional-covariance matrix--performs poorly. Two refinements are considered: Analyze Fisher Z-transformed correlations, and substitute better…

Substance Abuse Counselors and Moral Reasoning: Hypothetical and Authentic Dilemmas

ERIC Educational Resources Information Center

Sias, Shari M.

2009-01-01

This exploratory study examined the assumption that the level of moral reasoning (Defining Issues Test; J. R. Rest, 1986) used in solving hypothetical and authentic dilemmas is similar for substance abuse counselors (N = 188). The statistical analyses used were paired-sample t tests, Pearson product-moment correlation, and simultaneous multiple…

Classification of mouth movements using 7 T fMRI.

PubMed

Bleichner, M G; Jansma, J M; Salari, E; Freudenburg, Z V; Raemaekers, M; Ramsey, N F

2015-12-01

A brain-computer interface (BCI) is an interface that uses signals from the brain to control a computer. BCIs will likely become important tools for severely paralyzed patients to restore interaction with the environment. The sensorimotor cortex is a promising target brain region for a BCI due to the detailed topography and minimal functional interference with other important brain processes. Previous studies have shown that attempted movements in paralyzed people generate neural activity that strongly resembles actual movements. Hence decodability for BCI applications can be studied in able-bodied volunteers with actual movements. In this study we tested whether mouth movements provide adequate signals in the sensorimotor cortex for a BCI. The study was executed using fMRI at 7 T to ensure relevance for BCI with cortical electrodes, as 7 T measurements have been shown to correlate well with electrocortical measurements. Twelve healthy volunteers executed four mouth movements (lip protrusion, tongue movement, teeth clenching, and the production of a larynx activating sound) while in the scanner. Subjects performed a training and a test run. Single trials were classified based on the Pearson correlation values between the activation patterns per trial type in the training run and single trials in the test run in a 'winner-takes-all' design. Single trial mouth movements could be classified with 90% accuracy. The classification was based on an area with a volume of about 0.5 cc, located on the sensorimotor cortex. If voxels were limited to the surface, which is accessible for electrode grids, classification accuracy was still very high (82%). Voxels located on the precentral cortex performed better (87%) than the postcentral cortex (72%). The high reliability of decoding mouth movements suggests that attempted mouth movements are a promising candidate for BCI in paralyzed people.

Comparison of Performance of Eight-Year-Old Children on Three Auditory Sequential Memory Tests.

ERIC Educational Resources Information Center

Chermak, Gail D.; O'Connell, Vickie I.

1981-01-01

Twenty normal children were administered three tests of auditory sequential memory. A Pearson product-moment correlation of .50 and coefficients of determination showed all but one relationship to be nonsignificant and predictability between pairs of scores to be poor. (Author)

Statistical analysis of latent generalized correlation matrix estimation in transelliptical distribution.

PubMed

Han, Fang; Liu, Han

2017-02-01

Correlation matrix plays a key role in many multivariate methods (e.g., graphical model estimation and factor analysis). The current state-of-the-art in estimating large correlation matrices focuses on the use of Pearson's sample correlation matrix. Although Pearson's sample correlation matrix enjoys various good properties under Gaussian models, its not an effective estimator when facing heavy-tail distributions with possible outliers. As a robust alternative, Han and Liu (2013b) advocated the use of a transformed version of the Kendall's tau sample correlation matrix in estimating high dimensional latent generalized correlation matrix under the transelliptical distribution family (or elliptical copula). The transelliptical family assumes that after unspecified marginal monotone transformations, the data follow an elliptical distribution. In this paper, we study the theoretical properties of the Kendall's tau sample correlation matrix and its transformed version proposed in Han and Liu (2013b) for estimating the population Kendall's tau correlation matrix and the latent Pearson's correlation matrix under both spectral and restricted spectral norms. With regard to the spectral norm, we highlight the role of "effective rank" in quantifying the rate of convergence. With regard to the restricted spectral norm, we for the first time present a "sign subgaussian condition" which is sufficient to guarantee that the rank-based correlation matrix estimator attains the optimal rate of convergence. In both cases, we do not need any moment condition.

Correlates of health-promoting lifestyle behaviors among Vietnamese female immigrants in Taiwan.

PubMed

Hsiao, Chiu-Yueh; Chien, Maio-Ju; Wu, Hua-Shan; Chiao, Chia-Yi

2017-03-01

Immigration is a demanding and challenging life event that may cause married immigrant women to be likely to adopt unhealthy lifestyle behaviors. The aim of the authors of this study was to assess the prevalence of health-promoting lifestyle behaviors and their correlates among Vietnamese female immigrants in Taiwan. A cross-sectional study was conducted with 140 Vietnamese female immigrants from November 2012 to October 2013. Measures included demographic information, the Chinese Health Questionnaire, the General Functioning Scale of the Family Assessment Device, and a short version of the Chinese Health-Promoting Lifestyle Profile. Data analyses included descriptive statistics, Pearson's product-moment correlation coefficients, t-tests, one-way analysis of variance, and a hierarchical multiple regression analysis. Vietnamese female immigrants with better individual health status, higher education from their original country, greater communication ability, better health status of the husband, and adaptive family functioning demonstrated greater participation in health-promoting lifestyle behaviors. Particularly, better husband's health status and family functioning correlated with greater practices of health-promoting lifestyle behaviors after controlling for individual characteristics and experiences, with 38% of the total variance explained. Findings may serve to guide and design culturally specific, family-focused health promotion interventions to assist Vietnamese female immigrants and their families.

Antigen-Specific CD8 Lytic Phenotype Induced by Sipuleucel-T in Hormone-Sensitive or Castration-Resistant Prostate Cancer and Association With Overall Survival.

PubMed

Antonarakis, Emmanuel S; Small, Eric J; Petrylak, Daniel; Quinn, David I; Kibel, Adam S; Chang, Nancy; Dearstyne, Erica; Harmon, Matthew; Campogan, Dwayne; Haynes, Heather; Vu, Tuyen; Sheikh, Nadeem A; Drake, Charles G

2018-06-01

Sipuleucel-T is FDA-approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC) based on the IMPACT trial showing a 4.1-month benefit in median overall survival (OS) for patients receiving sipuleucel-T vs control. Although efficacy of sipuleucel-T is well-established, its mechanism remains incompletely understood. Patient samples from three sipuleucel-T trials were assessed for peripheral cellular immune responses to the immunogen PA2024 and the target antigen prostatic acid phosphatase (PAP). PAP- and PA2024-specific proliferative and cytolytic responses were characterized to delineate sipuleucel-T-induced immune responses. To quantify potential cytotoxic T lymphocyte (CTL) activity, cell-surface CD107a expression on PAP- or PA2024-specific CD8+ T cells was measured in sipuleucel-T-treated patient and healthy volunteer samples. Increased PA2024-specific CD4+ (p=0.030) and CD8+ (p=0.052) T-cell proliferation from baseline to week 6 was observed (N=14) post-sipuleucel-T, with greater magnitude of PA2024-specific responses compared to PAP. PAP- and PA2024-CTL activity (CD107a positivity) significantly increased at weeks 6 and 26 after sipuleucel-T treatment (p<0.0001; N=22). At 26 weeks post-sipuleucel-T, OS correlated with the magnitude of PAP (Pearson's R, 0.52; p=0.013) or PA2024 (Pearson's R, 0.67; p=0.0006) CTL activity. Higher PA2024-CTL activity at week 26 was significantly associated with longer OS using tertile analysis (p=0.0005; N=22), with PA2024 responses correlating with PAP responses at week 26 (R=0.90; p=1.53E -08 ). This study is the first to report PAP-specific CD8+ T-cell responses elicited by sipuleucel-T treatment. Increased and persistent potential PA2024-specific CTL activity correlated with PAP-specific CTL activity and associated with improved OS following sipuleucel-T treatment. Copyright ©2018, American Association for Cancer Research.

T1- Thresholds in Black Holes Increase Clinical-Radiological Correlation in Multiple Sclerosis Patients.

PubMed

Thaler, Christian; Faizy, Tobias; Sedlacik, Jan; Holst, Brigitte; Stellmann, Jan-Patrick; Young, Kim Lea; Heesen, Christoph; Fiehler, Jens; Siemonsen, Susanne

2015-01-01

Magnetic Resonance Imaging (MRI) is an established tool in diagnosing and evaluating disease activity in Multiple Sclerosis (MS). While clinical-radiological correlations are limited in general, hypointense T1 lesions (also known as Black Holes (BH)) have shown some promising results. The definition of BHs is very heterogeneous and depends on subjective visual evaluation. We aimed to improve clinical-radiological correlations by defining BHs using T1 relaxation time (T1-RT) thresholds to achieve best possible correlation between BH lesion volume and clinical disability. 40 patients with mainly relapsing-remitting MS underwent MRI including 3-dimensional fluid attenuated inversion recovery (FLAIR), magnetization-prepared rapid gradient echo (MPRAGE) before and after Gadolinium (GD) injection and double inversion-contrast magnetization-prepared rapid gradient echo (MP2RAGE) sequences. BHs (BHvis) were marked by two raters on native T1-weighted (T1w)-MPRAGE, contrast-enhancing lesions (CE lesions) on T1w-MPRAGE after GD and FLAIR lesions (total-FLAIR lesions) were detected separately. BHvis and total-FLAIR lesion maps were registered to MP2RAGE images, and the mean T1-RT were calculated for all lesion ROIs. Mean T1 values of the cortex (CTX) were calculated for each patient. Subsequently, Spearman rank correlations between clinical scores (Expanded Disability Status Scale and Multiple Sclerosis Functional Composite) and lesion volume were determined for different T1-RT thresholds. Significant differences in T1-RT were obtained between all different lesion types with highest T1 values in visually marked BHs (BHvis: 1453.3±213.4 ms, total-FLAIR lesions: 1394.33±187.38 ms, CTX: 1305.6±35.8 ms; p<0.05). Significant correlations between BHvis/total-FLAIR lesion volume and clinical disability were obtained for a wide range of T1-RT thresholds. The highest correlation for BHvis and total-FLAIR lesion masks were found at T1-RT>1500 ms (Expanded Disability Status Scale vs

$$t\\bar{t}$$ Spin Correlations at D0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, Yvonne

2013-01-01

The heaviest known elementary particle today, the top quark, has been discovered in 1995 by the CDF and D0 collaborations at the Tevatron collider at Fermilab. Its high mass and short lifetime, shorter than the timescale for hadronization, makes the top quark a special particle to study. Due to the short lifetime, the top quark's spin information is preserved in the decay products. In this article we discuss the studies of ttbar spin correlations at D0, testing the full chain from production to decay. In particular, we present a measurement using angular information and an analysis using a matrix-element basedmore » technique. The application of the matrix-element based technique to the ttbar dilepton and semileponic final state resulted in the first evidence for non-vanishing ttbar spin correlations.« less

Test-retest reliability of neurophysiological tests of hand-arm vibration syndrome in vibration exposed workers and unexposed referents.

PubMed

Gerhardsson, Lars; Gillström, Lennart; Hagberg, Mats

2014-01-01

Exposure to hand-held vibrating tools may cause the hand-arm vibration syndrome (HAVS). The aim was to study the test-retest reliability of hand and muscle strength tests, and tests for the determination of thermal and vibration perception thresholds, which are used when investigating signs of neuropathy in vibration exposed workers. In this study, 47 vibration exposed workers who had been investigated at the department of Occupational and Environmental Medicine in Gothenburg were compared with a randomized sample of 18 unexposed subjects from the general population of the city of Gothenburg. All participants passed a structured interview, answered several questionnaires and had a physical examination including hand and finger muscle strength tests, determination of vibrotactile (VPT) and thermal perception thresholds (TPT). Two weeks later, 23 workers and referents, selected in a randomized manner, were called back for the same test-procedures for the evaluation of test-retest reliability. The test-retest reliability after a two week interval expressed as limits of agreement (LOA; Bland-Altman), intra-class correlation coefficients (ICC) and Pearson correlation coefficients was excellent for tests with the Baseline hand grip, Pinch-grip and 3-Chuck grip among the exposed workers and referents (N = 23: percentage of differences within LOA 91 - 100%; ICC-values ≥0.93; Pearson r ≥0.93). The test-retest reliability was also excellent (percentage of differences within LOA 96-100 %) for the determination of vibration perception thresholds in digits 2 and 5 bilaterally as well as for temperature perception thresholds in digits 2 and 5, bilaterally (percentage of differences within LOA 91 - 96%). For ICC and Pearson r the results for vibration perception thresholds were good for digit 2, left hand and for digit 5, bilaterally (ICC ≥ 0.84; r ≥0.85), and lower (ICC = 0.59; r = 0.59) for digit 2, right hand. For the latter two indices the test

An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 2: Functional Performance Tests Correlate With Return-to-Sport Outcomes.

PubMed

McGrath, Timothy M; Waddington, Gordon; Scarvell, Jennie M; Ball, Nick; Creer, Rob; Woods, Kevin; Smith, Damian; Adams, Roger

2017-02-01

Additional high-quality prospective studies are needed to better define the objective criteria used in relation to return-to-sport decisions after anterior cruciate ligament (ACL) reconstruction in active populations. To investigate prospectively the relationship between functional performance test results at 24 weeks postoperative and return-to-sport activity (Tegner activity score) at 12 and 24 months, respectively, after synthetic (ligament advanced reinforcement system [LARS]) and autograft (doubled semitendinosus/gracilis [2ST/2GR]) ACL reconstructions. Case series; Level of evidence, 4. A total of 64 patients who underwent ACL reconstruction (32 LARS, 32 2ST/2GR autograft; mean age, 27.9 years; body mass index [BMI], 24.9 kg/m 2 ) were assessed preoperatively and at staged intervals postoperatively up to 24 weeks for isokinetic testing of quadriceps and hamstring average power per repetition at 60 deg/s and 180 deg/s, a battery of hop tests, peak vertical ground-reaction force (vGRF), and time to peak vGRF (in seconds) during a step- and jump-down task onto a force platform and peak speed (m/s) using a global positioning system (GPS unit) during a running task. A cohort of 32 healthy matched participants (mean age, 26.31 years; BMI, 25.7 kg/m 2 ) were also tested to act as reference. Pearson correlation was calculated to assess correlation of each performance measure at 24 weeks postoperative with activity outcomes (Tegner score) at 12 and 24 months. The strongest correlation between physical performance tests and return-to-sport outcomes was observed with peak speed during running. Large correlations were also observed for hamstring isokinetic power and hop test for distance. Moderate correlations were observed for timed hop, peak vGRF during a jump-down task, and quadriceps isokinetic power. No statistical correlations were observed for time to peak vGRF during a step-down and jump-down task as well as peak vGRF during a step-down task. When the performance

Correlation between adenoma detection rate in colonoscopy- and fecal immunochemical testing-based colorectal cancer screening programs.

PubMed

Cubiella, Joaquín; Castells, Antoni; Andreu, Montserrat; Bujanda, Luis; Carballo, Fernando; Jover, Rodrigo; Lanas, Ángel; Morillas, Juan Diego; Salas, Dolores; Quintero, Enrique

2017-03-01

The adenoma detection rate (ADR) is the main quality indicator of colonoscopy. The ADR recommended in fecal immunochemical testing (FIT)-based colorectal cancer screening programs is unknown. Using the COLONPREV (NCT00906997) study dataset, we performed a post-hoc analysis to determine if there was a correlation between the ADR in primary and work-up colonoscopy, and the equivalent figure to the minimal 20% ADR recommended. Colonoscopy was performed in 5722 individuals: 5059 as primary strategy and 663 after a positive FIT result (OC-Sensor™; cut-off level 15 µg/g of feces). We developed a predictive model based on a multivariable lineal regression analysis including confounding variables. The median ADR was 31% (range, 14%-51%) in the colonoscopy group and 55% (range, 21%-83%) in the FIT group. There was a positive correlation in the ADR between primary and work-up colonoscopy (Pearson's coefficient 0.716; p  < 0.001). ADR in the FIT group was independently related to ADR in the colonoscopy group: regression coefficient for colonoscopy ADR, 0.71 ( p  = 0.009); sex, 0.09 ( p  = 0.09); age, 0.3 ( p  = 0.5); and region 0.00 ( p  = 0.9). The equivalent figure to the 20% ADR was 45% (95% confidence interval, 35%-56%). ADR in primary and work-up colonoscopy of a FIT-positive result are positively and significantly correlated.

[Correlation index amylase-creatinine clearance to endogenous creatinine clearance in severe preeclampsia].

PubMed

Vázquez Rodríguez, Juan Gustavo; Cruz Cruz, Polita del Rocío; Márquez Hubert, Elizabeth

2009-07-01

Tubular lesion may cause acute renal insufficiency in pregnant patients with severe preeclampsia. To describe the correlation between the amylase/creatinine clearance ratio and endogenous creatinine depuration in pregnant patients with severe preeclampsia. Transversal study (pilot study) twenty eight women with pregnancies of 20 to 40 weeks complicated by severe preeclampsia were studied. Subjects had serum and urine creatinine and amylase determinations to calculate the amylase/creatinine clearance ratio (%). According to the results, two groups were formed: group A (> 3%) and group B (< or = 3%). The correlation between amylase/creatinine clearance ratio and endogenous creatinine depuration was evaluated. measures of central tendency and dispersion, Student's t-test, Pearson correlation coefficient (r) and linear regression were used. Group A included 23 cases (82%) and group B included 5 cases (18%). Amylase/creatinine clearance ratio (%) for group A was 5.22 +/- 1.6 and for group B was 2.41 +/- 0.41 (p = 0.001). The endogenous creatinine depuration (mL /min. /1.73 m2 SC) for group A was 105.6 +/- 9.71 and for group B was 132.10 +/- 7.95 (p = 0.54). The r between amylase/creatinine clearance ratio and endogenous creatinine depuration for group A was -0.43 and for group B was -0.25. A moderately significant negative correlation exists between amylase/creatinine clearance ratio and endogenous creatinine depuration.

High CD8+ and absence of Foxp3+ T lymphocytes infiltration in gallbladder tumors correlate with prolonged patients survival.

PubMed

Fluxá, Paula; Rojas-Sepúlveda, Daniel; Gleisner, María Alejandra; Tittarelli, Andrés; Villegas, Pablo; Tapia, Loreto; Rivera, María Teresa; López, Mercedes Natalia; Catán, Felipe; Uribe, Mario; Salazar-Onfray, Flavio

2018-03-02

Gallbladder cancer (GBC), although infrequent in industrialized countries, has high incidence rates in certain world regions, being a leading cause of death among elderly Chilean women. Surgery is the only effective treatment, and a five-year survival rate of advanced-stage patients is less than 10%. Hence, exploring immunotherapy is relevant, although GBC immunogenicity is poorly understood. This study examined the relationship between the host immune response and GBC patient survival based on the presence of tumor-infiltrating lymphocytes at different disease stages. Tumor tissues from 80 GBC patients were analyzed by immunohistochemistry for the presence of CD3 + , CD4 + , CD8 + , and Foxp3 + T cell populations, and the results were associated with clinical stage and patient survival. The majority of tumor samples showed CD3 + T cell infiltration, which correlated with better prognosis, particularly in advanced disease stages. CD8 + , but not CD4 + , T cell infiltration correlated with improved survival, particularly in advanced disease stages. Interestingly, a < 1 CD4 + /CD8 + T cell ratio was related with increased survival. Additionally, the presence of Foxp3 + T cells correlated with decreased patient survival, whereas a ≤ 1 Foxp3 + /CD8 + T cell ratio was associated with improved patient survival. Depending on the disease stage, the presence of CD8 + and absence of Foxp3 + T cell populations in tumor tissues correlated with improved GBC patient survival, and thus represent potential markers for prognosis and management of advanced disease, and supports testing of immunotherapy.

Test Review: Wechsler, D. (2014),"Wechsler Intelligence Scale for Children, Fifth Edition: Canadian 322 (WISC-V[superscript CDN])." Toronto, Ontario: Pearson Canada Assessment.

ERIC Educational Resources Information Center

Cormier, Damien C.; Kennedy, Kathleen E.; Aquilina, Alexandra M.

2016-01-01

The Wechsler Intelligence Scale for Children, Fifth Edition: Canadian (WISC-V[superscript CDN]; Wechsler, 2014) is published by Pearson Canada Assessment. The WISC-V[superscript CDN] is a norm-referenced, individually administered intelligence battery that provides a comprehensive diagnostic profile of the cognitive strengths and weaknesses of…

Development of a Tablet-based symbol digit modalities test for reliably assessing information processing speed in patients with stroke.

PubMed

Tung, Li-Chen; Yu, Wan-Hui; Lin, Gong-Hong; Yu, Tzu-Ying; Wu, Chien-Te; Tsai, Chia-Yin; Chou, Willy; Chen, Mei-Hsiang; Hsieh, Ching-Lin

2016-09-01

To develop a Tablet-based Symbol Digit Modalities Test (T-SDMT) and to examine the test-retest reliability and concurrent validity of the T-SDMT in patients with stroke. The study had two phases. In the first phase, six experts, nine college students and five outpatients participated in the development and testing of the T-SDMT. In the second phase, 52 outpatients were evaluated twice (2 weeks apart) with the T-SDMT and SDMT to examine the test-retest reliability and concurrent validity of the T-SDMT. The T-SDMT was developed via expert input and college student/patient feedback. Regarding test-retest reliability, the practise effects of the T-SDMT and SDMT were both trivial (d=0.12) but significant (p≦0.015). The improvement in the T-SDMT (4.7%) was smaller than that in the SDMT (5.6%). The minimal detectable changes (MDC%) of the T-SDMT and SDMT were 6.7 (22.8%) and 10.3 (32.8%), respectively. The T-SDMT and SDMT were highly correlated with each other at the two time points (Pearson's r=0.90-0.91). The T-SDMT demonstrated good concurrent validity with the SDMT. Because the T-SDMT had a smaller practise effect and less random measurement error (superior test-retest reliability), it is recommended over the SDMT for assessing information processing speed in patients with stroke. Implications for Rehabilitation The Symbol Digit Modalities Test (SDMT), a common measure of information processing speed, showed a substantial practise effect and considerable random measurement error in patients with stroke. The Tablet-based SDMT (T-SDMT) has been developed to reduce the practise effect and random measurement error of the SDMT in patients with stroke. The T-SDMT had smaller practise effect and random measurement error than the SDMT, which can provide more reliable assessments of information processing speed.

Evaluation of Fitness and the Balance Levels of Children with a Diagnosis of Juvenile Idiopathic Arthritis: A Pilot Study.

PubMed

Patti, Antonino; Maggio, Maria Cristina; Corsello, Giovanni; Messina, Giuseppe; Iovane, Angelo; Palma, Antonio

2017-07-19

Background: Juvenile idiopathic arthritis is a main cause of physical disability and has high economic costs for society. The purpose of this study was to assess the fitness levels and the postural and balance deficits with a specific test battery. Methods: Fifty-six subjects were enrolled in this study. Thirty-nine healthy subjects were included in the control group and seventeen in the juvenile idiopathic arthritis group. All subjects were evaluated using a posturography system. The fitness level was evaluated with a battery of tests (Abalakov test, sit-up test, hand grip test, backsaver sit and reach, the toe touch test). An unpaired t -test was used to determine differences. Pearson's correlation coefficient was used to evaluate the correlation between the tests. Results: The battery of tests demonstrated that subjects in the juvenile idiopathic arthritis group have lower fitness levels compared to the control group. The juvenile idiopathic arthritis group showed low postural control with respect to the control group. Pearson analysis of the juvenile idiopathic arthritis group data showed significant correlations between variables. Pearson's results from the control group data showed a similar trend. Conclusions: The results suggest that the battery of tests used could be an appropriate tool. However, we highlight that these conclusions need to be supported by other studies with a larger population scale.

The 3-min all-out test is valid for determining critical power but not anaerobic work capacity in tethered running

PubMed Central

2018-01-01

The purpose of the study was to investigate if the 3-min all-out test (3MT) is valid for obtaining critical power intensity (CP) and the amount of work that can be performed above CP (W’) on non-motorized treadmills in tethered running. Eight physically active individuals (24 ± 3 years; 78.3 ± 8.7 kg; 179 ± 5 cm; 9.0 ± 2.5% body fat) performed four different efforts at constant intensity to exhaustion in order to determine CP and W’. The mechanical power values obtained were subsequently plotted with their corresponding time to exhaustion (limit time) for application of three mathematical models: power hyperbolic versus time limit (Hyp), linear power versus 1/time (P vs 1/t) and linear work versus time limit (Ԏ vs t). The 3MT test was carried out on the last day to determine end power (EP) and anaerobic capacity (WEP) using this methodology. EP value of 181.7 ± 52 was similar (p = 0.486) to 178.2 ± 61 (CP Hyp), 191.4 ± 55 (Ԏ vs t) and 188.3 ± 55 (P vs 1/t). WEP value of 17.9 ± 4.8 was not similar (p = 0.000) to 50.2 ± 15.3 (CP Hyp), 44.8 ± 8.7 (Ԏ vs t) and 45.5 ± 8.4 (P vs 1/t). Positive results (r = 0.78–0.98 and ICC = 0.88–0.99) of Pearson correlation and intraclass correlation (ICC–absolute agreement) were found for aerobic applications of conventional CP and 3MT. For anaerobic data, only the three models of conventional CP were correlated (r = 0.76–0.93); however, W’ from the three models was not correlated with WEP (r = 0.37–0.52). The results of this study suggest that 3MT in tethered running on non-motorized treadmills is a valid test for estimating CP aerobic parameters in a single day of application but not anaerobic parameters of W’. PMID:29444141

Reliability and validity of an audio signal modified shuttle walk test.

PubMed

Singla, Rupak; Rai, Richa; Faye, Abhishek Anil; Jain, Anil Kumar; Chowdhury, Ranadip; Bandyopadhyay, Debdutta

2017-01-01

The audio signal in the conventionally accepted protocol of shuttle walk test (SWT) is not well-understood by the patients and modification of the audio signal may improve the performance of the test. The aim of this study is to study the validity and reliability of an audio signal modified SWT, called the Singla-Richa modified SWT (SWTSR), in healthy normal adults. In SWTSR, the audio signal was modified with the addition of reverse counting to it. A total of 54 healthy normal adults underwent conventional SWT (CSWT) at one instance and two times SWTSRon the same day. The validity was assessed by comparing outcomes of the SWTSRto outcomes of CSWT using the Pearson correlation coefficient and Bland-Altman plot. Test-retest reliability of SWTSRwas assessed using the intraclass correlation coefficient (ICC). The acceptability of the modified test in comparison to the conventional test was assessed using Likert scale. The distance walked (mean ± standard deviation) in the CSWT and SWTSRtest was 853.33 ± 217.33 m and 857.22 ± 219.56 m, respectively (Pearson correlation coefficient - 0.98; P < 0.001) indicating SWTSRto be a valid test. The SWTSRwas found to be a reliable test with ICC of 0.98 (95% confidence interval: 0.97-0.99). The acceptability of SWTSRwas significantly higher than CSWT. The SWTSRwith modified audio signal with reverse counting is a reliable as well as a valid test when compared with CSWT in healthy normal adults. It better understood by subjects compared to CSWT.

The relation between FoxP3⁺ regulatory T cells and fungal density in oral paracoccidioidomycosis: a preliminary study.

PubMed

Cardoso, Rhanderson Miller Nascimento; Jham, Bruno Correia; do Carmo, Gabriela Mota; Batista, Aline Carvalho; de Oliveira, Flávia Aparecida; de Paula, Elbio Candido; Mesquita, Ricardo Alves; da Silva, Tarcília Aparecida; Duarte, Eliza Carla Barroso

2014-12-01

Regulatory T (Treg) cells may play an important role in the pathogenesis of paracoccidioidomycosis (PCM), but data on the role of Treg cells in the context of oral PCM are still scarce. The objectives of this study were to investigate the density of FoxP3(+) T regulatory cells in oral PCM and to correlate the results with the density of Paracoccidioides brasiliensis in the lesions. Cases of chronic oral PCM seen between 2000 and 2008 were included in this study. The diagnosis of all lesions was confirmed with histopathological examination and Grocott-Gomori staining. The quantitative analysis of the viable fungi was conducted in all cases with Grocott-stained slides. Treg cells were identified using antibodies against FoxP3. Pearson correlation coefficient was used to test the correlation between the density of fungi and Treg cells. Results were considered significant when P < 0.05. A total of 11 cases of oral PCM were obtained. There was a positive correlation between fungal density and FoxP3(+) Treg cells density in oral lesions, however, without statistical significance. A positive relation between Treg cells and fungal density was seen in oral PCM. Further studies are required to further elucidate the role of these cells in the pathogenesis of oral PCM, as well the clinical significance of these findings. © 2014 Blackwell Verlag GmbH.

On the insignificance of Herschel's sunspot correlation

NASA Astrophysics Data System (ADS)

Love, Jeffrey J.

2013-08-01

We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is "statistically significant." On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are "insignificant." Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

On the insignificance of Herschel's sunspot correlation

USGS Publications Warehouse

Love, Jeffrey J.

2013-01-01

We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is “statistically significant.” On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are “insignificant.” Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

T2* mapping of hip joint cartilage in various histological grades of degeneration.

PubMed

Bittersohl, B; Miese, F R; Hosalkar, H S; Herten, M; Antoch, G; Krauspe, R; Zilkens, C

2012-07-01

To evaluate T2* values in various histological severities of osteoarthritis (OA). Magnetic resonance imaging (MRI) and T2* mapping including a three-dimensional (3D) double-echo steady-state (DESS) sequence for morphological cartilage assessment and a 3D multiecho data image combination (MEDIC) sequence for T2* mapping were conducted in 21 human femoral head specimens with varying severities of OA. Subsequently, histological assessment was undertaken in all specimens to correlate the observations of T2* mapping with histological analyses. According to the Mankin score, four grades of histological changes were determined: grade 0 (Mankin scores of 0-4), grade I (scores of 5-8), grade II (scores of 9-10), and grade III (scores of 11-14). For reliability assessment, cartilage T2* measurements were repeated after 4 weeks in 10 randomly selected femoral head specimens. T2* values decreased significantly with increasing cartilage degeneration (total P-values <0.001) ranging from 36.3 ± 4.3 ms in grade 0 regions to 22.8 ± 4.3 ms in regions with grade III changes. Pearson correlation analysis proved a fair correlation between T2* values and Mankin score (correlation coefficient = -0.362) that was statistically significant (P-value <0.001). Intra-class correlation (ICC) analysis demonstrated high intra-observer reproducibility for the T2* measurement (ICC: 0.949, P < 0.001). Given the advantages of the T2* mapping technique with no need for contrast medium, high image resolution and ability to perform 3D biochemically sensitive imaging, T2* mapping may be a strong addition to the currently evolving era of cartilage biochemical imaging. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

[Polar S810 as an alternative resource to the use of the electrocardiogram in the 4-second exercise test].

PubMed

Pimentel, Alan Santos; Alves, Eduardo da Silva; Alvim, Rafael de Oliveira; Nunes, Rogério Tasca; Costa, Carlos Magno Amaral; Lovisi, Júlio Cesar Moraes; Perrout de Lima, Jorge Roberto

2010-05-01

The 4-second exercise test (T4s) evaluates the cardiac vagal tone during the initial heart rate (HR) transient at sudden dynamic exercise, through the identification of the cardiac vagal index (CVI) obtained from the electrocardiogram (ECG). To evaluate the use of the Polar S810 heart rate monitor (HRM) as an alternative resource to the use of the electrocardiogram in the 4-second exercise test. In this study, 49 male individuals (25 +/- 20 years, 176 +/-12 cm, 74 +/- 6 kg) underwent the 4-second exercise test. The RR intervals were recorded simultaneously by ECG and HRM. We calculated the mean and the standard deviation of the last RR interval of the pre-exercise period, or of the first RR interval of the exercise period, whichever was longer (RRB), of the shortest RR interval of the exercise period (RRC), and of the CVI obtained by ECG and HRM. We used the Student t-test for dependent samples (p < or 0.05) to test the significance of the differences between means. To identify the correlation between the ECG and the HRM, we used the linear regression to calculate the Pearson's correlation coefficient and the strategy proposed by Bland and Altman. Linear regression showed r(2) of 0.9999 for RRB, 0.9997 for RRC, and 0.9996 for CVI. Bland e Altman strategy presented standard deviation of 0.92 ms for RRB, 0.86 ms for RRC, and 0.002 for CVI. Polar S810 HRM was more efficient in the application of T4s compared to the ECG.

"Describing our whole experience": the statistical philosophies of W. F. R. Weldon and Karl Pearson.

PubMed

Pence, Charles H

2011-12-01

There are two motivations commonly ascribed to historical actors for taking up statistics: to reduce complicated data to a mean value (e.g., Quetelet), and to take account of diversity (e.g., Galton). Different motivations will, it is assumed, lead to different methodological decisions in the practice of the statistical sciences. Karl Pearson and W. F. R. Weldon are generally seen as following directly in Galton's footsteps. I argue for two related theses in light of this standard interpretation, based on a reading of several sources in which Weldon, independently of Pearson, reflects on his own motivations. First, while Pearson does approach statistics from this "Galtonian" perspective, he is, consistent with his positivist philosophy of science, utilizing statistics to simplify the highly variable data of biology. Weldon, on the other hand, is brought to statistics by a rich empiricism and a desire to preserve the diversity of biological data. Secondly, we have here a counterexample to the claim that divergence in motivation will lead to a corresponding separation in methodology. Pearson and Weldon, despite embracing biometry for different reasons, settled on precisely the same set of statistical tools for the investigation of evolution. Copyright © 2011 Elsevier Ltd. All rights reserved.

Measuring hepatic functional reserve using T1 mapping of Gd-EOB-DTPA enhanced 3T MR imaging: A preliminary study comparing with 99mTc GSA scintigraphy and signal intensity based parameters.

PubMed

Nakagawa, Masataka; Namimoto, Tomohiro; Shimizu, Kie; Morita, Kosuke; Sakamoto, Fumi; Oda, Seitaro; Nakaura, Takeshi; Utsunomiya, Daisuke; Shiraishi, Shinya; Yamashita, Yasuyuki

2017-07-01

To determine the utility of liver T1-mapping on gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance (MR) imaging for the measurement of liver functional reserve compared with the signal intensity (SI) based parameters, technetium-99m-galactosyl serum albumin ( 99m Tc-GSA) scintigraphy and indocyanine green (ICG) clearance. This retrospective study included 111 patients (Child-Pugh-A 90; -B 21) performed with both Gd-EOB-DTPA enhanced liver MR imaging and 99m Tc-GSA (76 patients with ICG). Receiver operating characteristic (ROC) curve analysis was performed to compare diagnostic performances of T1-relaxation-time parameters [pre-(T1pre) and post-contrast (T1hb) Gd-EOB-DTPA], SI based parameters [relative enhancement (RE), liver-to-muscle-ratio (LMR), liver-to-spleen-ratio (LSR)] and 99m Tc-GSA scintigraphy blood clearance index (HH15)] for Child-Pugh classification. Pearson's correlation was used for comparisons among T1-relaxation-time parameters, SI-based parameters, HH15 and ICG. A significant difference was obtained for Child-Pugh classification with T1hb, ΔT1, all SI based parameters and HH15. T1hb had the highest AUC followed by RE, LMR, LSR, ΔT1, HH15 and T1pre. The correlation coefficients with HH15 were T1pre 0.22, T1hb 0.53, ΔT1 -0.38 of T1 relaxation parameters; RE -0.44, LMR -0.45, LSR -0.43 of SI-based parameters. T1hb was highest for correlation with HH15. The correlation coefficients with ICG were T1pre 0.29, T1hb 0.64, ΔT1 -0.42 of T1 relaxation parameters; RE -0.50, LMR -0.61, LSR -0.58 of SI-based parameters; 0.64 of HH15. Both T1hb and HH15 were highest for correlation with ICG. T1 relaxation time at post-contrast of Gd-EOB-DTPA (T1hb) was strongly correlated with ICG clearance and moderately correlated HH15 with 99m Tc-GSA. T1hb has the potential to provide robust parameter of liver functional reserve. Copyright © 2017 Elsevier B.V. All rights reserved.

Are Mucosa CD4+/CD8+ T-Cells Expressions Correlated with the Endoscopic Appearance of Chronic Gastritis Related with Helicobacter pylori Infection?

PubMed

Ratnasari, Neneng; Bayupurnama, Putut; Maduseno, Sutanto; Indrarti, Fahmi; Triwikatmani, Catharina; Harijadi, Achmad; Nurdjanah, Siti

2016-06-01

Local inflammatory processes in the gastric mucosa are followed by extensive immune cell infiltration, resulting in chronic active gastritis characterized by a marked infiltration of T(h)1 cytokine-producing CD4+ and CD8+T-cells Objective. To investigate the correlation between CD4+/CD8+ T-cells in gastric mucosa with endoscopic appearance in chronic gastritis with or without H.pylori infection. Prospective, cross sectional study is performed in a chronic dyspepsia population in July-November 2009 at Dr. Sardjito General Hospital Yogyakarta, Indonesia. The update Sydney system was used to analyze the gastroscopy appearance. Biopsy specimens were stained with HE-stain and IHC-stain. Data were analyzed by t-test, Mann-Whitney and Spearman correlation test. Number of 88 consecutive subjects are enrolled the study (50% male; 50% female), age 46±15 years; 25% H.pylori positive. The expression of CD4+ and CD8+ were higher in H.pylori negative subjects, but only the CD4+ was significant (P=0.011). A significant correlation was found between CD4+ and CD8+ in both subjects (r(Hp+)=0.62 and r(Hp-)=0.68; P<0.05). The expression of CD4+ and CD8+ in H.pylori positive showed a significant correlation with gastric lesions (r(CD4+)=-0.60; r(CD8+)=-0.42 ; P<0.05), only erosion showed a significant difference in both subjects. A positive correlation was found between CD4+ and CD8+ infiltration in both subjects with or without H.pylori infection, and a negative correlation was only found between gastric lesion with CD4+ and CD8+ infiltration in H.pylori subject.

Predicting neuropsychological test performance on the basis of temporal orientation.

PubMed

Ryan, Joseph J; Glass, Laura A; Bartels, Jared M; Bergner, CariAnn M; Paolo, Anthony M

2009-05-01

Temporal orientation is often disrupted in the context of psychiatric or neurological disease; tests assessing this function are included in most mental status examinations. The present study examined the relationship between scores on the Temporal Orientation Scale (TOS) and performance on a battery of tests that assess memory, language, and cognitive functioning in a sample of patients with Alzheimer's disease (N = 55). Pearson-product moment correlations showed that, in all but two instances, the TOS was significantly correlated with each neuropsychological measure, p values < or = .05. Also, severely disoriented (i.e., TOS score < or = -8) patients were consistently 'impaired' on memory tests but not on tests of language and general cognitive functioning.

Clinical applications of correlational vestibular autorotation test.

PubMed

Hsieh, Li-Chun; Lin, Te-Ming; Chang, Yu-Min; Kuo, Terry B J; Lee, Gho-She

2015-06-01

The correlational vestibular autorotation test (VAT) system has the advantages of good test-retest reliability and calibrations of absolute degrees of eye movement are unnecessary when acquiring a cross correlation coefficient (CCC). The approach is able to efficiently detect peripheral vestibulopathies. A VAT has some drawbacks including poor test-retest reliability and slippage of sensor. This study aimed to develop a correlational VAT system and to evaluate the reliability and applicability of this system. Twenty healthy participants and 10 vertiginous patients were enrolled. Vertical and horizontal autorotations from 0 to 3 Hz with either closed or open eyes were performed. A small sensor and a wireless transmission technique were used to acquire the electro-ocular graph and head velocity signals. The two signals were analyzed using CCCs to assess the functioning of the vestibular ocular reflex (VOR). The results showed a significantly greater CCC for open-eye versus closed-eye of head autorotations. The CCCs also increased significantly with head rotational frequencies. Moreover, the CCCs significantly correlated with the VOR gains at autorotation frequencies ≥1.0 Hz. The test-retest reliability was good (intraclass correlation coefficients ≥0.85). The vertiginous participants had significantly lower individual CCCs and overall average CCC than age- and-gender matched controls.

A test of the hypothesis that correlational selection generates genetic correlations.

PubMed

Roff, Derek A; Fairbairn, Daphne J

2012-09-01

Theory predicts that correlational selection on two traits will cause the major axis of the bivariate G matrix to orient itself in the same direction as the correlational selection gradient. Two testable predictions follow from this: for a given pair of traits, (1) the sign of correlational selection gradient should be the same as that of the genetic correlation, and (2) the correlational selection gradient should be positively correlated with the value of the genetic correlation. We test this hypothesis with a meta-analysis utilizing empirical estimates of correlational selection gradients and measures of the correlation between the two focal traits. Our results are consistent with both predictions and hence support the underlying hypothesis that correlational selection generates a genetic correlation between the two traits and hence orients the bivariate G matrix. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Direct correlation between serum homocysteine level and insulin resistance index in patients with subclinical hypothyroidism: Does subclinical hypothyroidism increase the risk of diabetes and cardio vascular disease together?

PubMed

Ebrahimpour, Anahita; Vaghari-Tabari, Mostafa; Qujeq, Durdi; Moein, Soheila; Moazezi, Zoleikha

2018-05-05

Subclinical hypothyroidism known as mild thyroid disorder without significant sign and symptoms. The correlation between subclinical hypothyroidism and some of cardiovascular disease risk factors such as serum lipids, homocysteine levels and also insulin resistance index is not well established and the current study was conducted to clarify this issue. Seventy four patients with mild elevation in levels of thyroid stimulating hormone (TSH) along with normal levels of T3 and T4 were selected as patients group and 74 age and sex matched individuals were selected as healthy control group. Serum insulin, triglyceride, glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol and homocysteine levels were measured. Obtained data compared between groups with independent sample t-test. For evaluation of the correlation between mentioned parameters Pearson correlation coefficient method was used. Serum levels of LDL-C and total cholesterol significantly increased in SCH group compared to healthy control group. Homeostatic Model Assessment of Insulin Resistance (HOM-IR) and serum homocysteine level significantly elevated in patients with SCH compared to control group. There was a significant direct correlation between HOM-IR and serum homocysteine levels in SCH patients. Subclinical hypothyroidism likely have significant effect on insulin resistance as major diabetes risk factors and also cardiovascular disease risk factors such as homocysteine. The direct correlation between HOM-IR with serum homocysteine level indicate the possible role of insulin resistance in elevation of serum homocysteine in SCH patient group. Copyright © 2018 Diabetes India. Published by Elsevier Ltd. All rights reserved.

NDRG2 correlated with favorable recurrence-free survival inhibits metastasis of mouse breast cancer cells via attenuation of active TGF-β production.

PubMed

Oh, Sang-seok; Kim, Donghyeok; Kim, Dong-Hee; Chang, Hong Hee; Sohn, Kyung-Cheol; Kim, Kyo Hyun; Jung, Sung Hoo; Lee, Byoung Kil; Kim, Joo Heon; Kim, Kwang Dong

2012-10-01

N-myc downstream-regulated gene 2 (NDRG2) has been studied for its inhibitory effects against growth and metastasis of many tumor cell types. In this study, we showed NDRG2 expression was correlated with favorable recurrence-free survival of patients with breast cancer and inhibited metastasis of breast cancer cells (4T1). NDRG2 expression was examined in 189 breast carcinoma tissues and paired normal breast tissues using immunohistochemistry. Histological and clinicopathological data were correlated using Pearson's chi-square test of independence. NDRG2 expression in human breast cancer tissues was inversely associated with lymph node metastasis and pTNM stage. Furthermore, patients with breast cancer with a high level of NDRG2 expression showed favorable recurrence-free survival (P = 0.038). To study the effect of NDRG2 on metastasis in vivo, we established an NDRG2-overexpressing mouse breast cancer cell line (4T1-NDRG2) and measured the metastasis and survival of 4T1-NDRG2 tumor-bearing mice. To test whether transforming growth factor β (TGF-β)- mediated metastasis of 4T1 was inhibited by NDRG2 expression, TGF-Smad-binding element (SBE)-luciferase activity and/or measurement of active TGF-β were performed in cell or tumor tissue level. 4T1-NDRG2 cells grew gradually and showed less metastatic activity in vivo and low invasiveness in vitro. 4T1-NDRG2 cells showed lower SBE-luciferase activity and lower level of active autocrine TGF-β than 4T1-Mock did. Correctly, our data show that NDRG2 significantly suppress tumor metastasis by attenuating active autocrine TGF-β production, and the attenuation might be typically associated with the favorable recurrence-free survival of patients clinically.

Correlation of Space Shuttle Landing Performance with Post-Flight Cardiovascular Dysfunction

NASA Technical Reports Server (NTRS)

McCluskey, R.

2004-01-01

Introduction: Microgravity induces cardiovascular adaptations resulting in orthostatic intolerance on re-exposure to normal gravity. Orthostasis could interfere with performance of complex tasks during the re-entry phase of Shuttle landings. This study correlated measures of Shuttle landing performance with post-flight indicators of orthostatic intolerance. Methods: Relevant Shuttle landing performance parameters routinely recorded at touchdown by NASA included downrange and crossrange distances, airspeed, and vertical speed. Measures of cardiovascular changes were calculated from operational stand tests performed in the immediate post-flight period on mission commanders from STS-41 to STS-66. Stand test data analyzed included maximum standing heart rate, mean increase in maximum heart rate, minimum standing systolic blood pressure, and mean decrease in standing systolic blood pressure. Pearson correlation coefficients were calculated with the null hypothesis that there was no statistically significant linear correlation between stand test results and Shuttle landing performance. A correlation coefficient? 0.5 with a p<0.05 was considered significant. Results: There were no significant linear correlations between landing performance and measures of post-flight cardiovascular dysfunction. Discussion: There was no evidence that post-flight cardiovascular stand test data correlated with Shuttle landing performance. This implies that variations in landing performance were not due to space flight-induced orthostatic intolerance.

Test – Retest Reliability and Concurrent Validity of in vivo Myelin Content Indices: Myelin Water Fraction and Calibrated T1w/T2w Image Ratio

PubMed Central

Arshad, Muzamil; Stanley, Jeffrey A.; Raz, Naftali

2016-01-01

In an age-heterogeneous sample of healthy adults, we examined test-retest reliability (with and without participant re-positioning) of two popular MRI methods of estimating myelin content: modeling the short spin-spin (T2) relaxation component of multi-echo imaging data and computing the ratio of T1-weighted and T2-weighted images (T1w/T2w). Taking the myelin water fraction (MWF) index of myelin content derived from the multi-component T2 relaxation data as a standard, we evaluate the concurrent and differential validity of T1w/T2w ratio images. The results revealed high reliability of MWF and T1w/T2w ratio. However, we found significant correlations of low to moderate magnitude between MWF and the T1w/T2w ratio in only two of six examined regions of the cerebral white matter. Notably, significant correlations of the same or greater magnitude were observed for T1w/T2w ratio and the intermediate T2 relaxation time constant, which is believed to reflect differences in the mobility of water between the intracellular and extracellular compartments. We conclude that although both methods are highly reliable and thus well-suited for longitudinal studies, T1w/T2w ratio has low criterion validity and may be not an optimal index of subcortical myelin content. PMID:28009069

The Correlates of Body Composition with Heart Rate Recovery after Step Test: An Exploratory Study of Malaysian Adolescents

PubMed Central

Abu Hanifah, Redzal; Mohamed, Mohd. Nahar Azmi; Jaafar, Zulkarnain; Abdul Mohsein, Nabilla Al-Sadat; Jalaludin, Muhammad Yazid; Abdul Majid, Hazreen; Murray, Liam; Cantwell, Marie; Su, Tin Tin

2013-01-01

Background In adults, heart rate recovery is a predictor of mortality, while in adolescents it is associated with cardio-metabolic risk factors. The aim of this study was to examine the relationship between body composition measures and heart rate recovery (HRR) after step test in Malaysian secondary school students. Methods In the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study, 1071 healthy secondary school students, aged 13 years old, participated in the step test. Parameters for body composition measures were body mass index z-score, body fat percentage, waist circumference, and waist height ratio. The step test was conducted by using a modified Harvard step test. Heart rate recovery of 1 minute (HRR1min) and heart rate recovery of 2 minutes (HRR2min) were calculated by the difference between the peak pulse rate during exercise and the resting pulse rate at 1 and 2 minutes, respectively. Analysis was done separately based on gender. Pearson correlation analysis was used to determine the association between the HRR parameters with body composition measures, while multiple regression analysis was used to determine which body composition measures was the strongest predictor for HRR. Results For both gender groups, all body composition measures were inversely correlated with HRR1min. In girls, all body composition measures were inversely correlated with HRR2min, while in boys all body composition measures, except BMI z-score, were associated with HRR2min. In multiple regression, only waist circumference was inversely associated with HRR2min (p=0.024) in boys, while in girls it was body fat percentage for HRR2min (p=0.008). Conclusion There was an inverse association between body composition measurements and HRR among apparently healthy adolescents. Therefore, it is important to identify cardio-metabolic risk factors in adolescent as an early prevention of consequent adulthood morbidity. This reiterates the importance of healthy living

Correlation between heat shock proteins, adiponectin, and T lymphocyte cytokine expression in type 2 diabetics.

PubMed

Mahmoud, Fadia F; Haines, David; Dashti, Ali A; El-Shazly, Sherief; Al-Najjar, Fawzia

2018-05-11

Type 2 diabetes mellitus (T2DM) features insulin resistance, hyperglycemia, dyslipidemia, overproduction of inflammatory cytokines, and systemic oxidative stress. Here, heat shock proteins Hsp70 and Hsp 90, adiponectin, and heme oxygenase-1 (HO-1, Hsp32) are profiled in peripheral blood mononuclear cells (PBMC) and serum from 25 T2DM patients and 25 healthy control subjects. Cells cultured with phorbol 12-myristate 13-acetate/ionomycin were evaluated by three-color flow cytometry for immunophenotypic biomarkers. Plasma HO-1, Hsp, and adiponectin levels were assayed by enzyme-linked immunosorbent assay (ELISA). Relative to healthy controls, T2DM patients exhibited significantly elevated plasma Hsp70, and representation of T helper immunophenotypes activated to express inflammatory cytokines, including CD4+ IFN-γ+, CD4+ TNF-α+, CD4+ IL-6+, CD4+ IL-1β+ T cells, significantly lower representation of CD4+ IL-10+ T cells, plasma adiponectin and cell-associated HO-1 expression-with no significant differences in plasma Hsp90 between T2DM and healthy controls. Plasma HO-1 and adiponectin in T2DM patients inversely correlated with TNF-α and showed inverse correlation between serum LDL and plasma HO-1. Moreover, TNF-α and Hsp90 in T2DM patients correlated positively with fasting blood glucose (FBG). These results demonstrate correlation between potentially pathogenic T cells, HO-1, and adiponectin, additionally revealing a T helper (Th)1-related character of T2DM immunopathogenesis, suggesting potential for novel T cell-related management strategies for T2DM and related co-morbidities.

Cross correlation calculations and neutron scattering analysis for a portable solid state neutron detection system

NASA Astrophysics Data System (ADS)

Saltos, Andrea

In efforts to perform accurate dosimetry, Oakes et al. [Nucl. Intrum. Mehods. (2013)] introduced a new portable solid state neutron rem meter based on an adaptation of the Bonner sphere and the position sensitive long counter. The system utilizes high thermal efficiency neutron detectors to generate a linear combination of measurement signals that are used to estimate the incident neutron spectra. The inversion problem associated to deduce dose from the counts in individual detector elements is addressed by applying a cross-correlation method which allows estimation of dose with average errors less than 15%. In this work, an evaluation of the performance of this system was extended to take into account new correlation techniques and neutron scattering contribution. To test the effectiveness of correlations, the Distance correlation, Pearson Product-Moment correlation, and their weighted versions were performed between measured spatial detector responses obtained from nine different test spectra, and the spatial response of Library functions generated by MCNPX. Results indicate that there is no advantage of using the Distance Correlation over the Pearson Correlation, and that weighted versions of these correlations do not increase their performance in evaluating dose. Both correlations were proven to work well even at low integrated doses measured for short periods of time. To evaluate the contribution produced by room-return neutrons on the dosimeter response, MCNPX was used to simulate dosimeter responses for five isotropic neutron sources placed inside different sizes of rectangular concrete rooms. Results show that the contribution of scattered neutrons to the response of the dosimeter can be significant, so that for most cases the dose is over predicted with errors as large as 500%. A possible method to correct for the contribution of room-return neutrons is also assessed and can be used as a good initial estimate on how to approach the problem.

Dynamic test/analysis correlation using reduced analytical models

NASA Technical Reports Server (NTRS)

Mcgowan, Paul E.; Angelucci, A. Filippo; Javeed, Mehzad

1992-01-01

Test/analysis correlation is an important aspect of the verification of analysis models which are used to predict on-orbit response characteristics of large space structures. This paper presents results of a study using reduced analysis models for performing dynamic test/analysis correlation. The reduced test-analysis model (TAM) has the same number and orientation of DOF as the test measurements. Two reduction methods, static (Guyan) reduction and the Improved Reduced System (IRS) reduction, are applied to the test/analysis correlation of a laboratory truss structure. Simulated test results and modal test data are used to examine the performance of each method. It is shown that selection of DOF to be retained in the TAM is critical when large structural masses are involved. In addition, the use of modal test results may provide difficulties in TAM accuracy even if a large number of DOF are retained in the TAM.

Test-retest reliability and concurrent validity of in vivo myelin content indices: Myelin water fraction and calibrated T1 w/T2 w image ratio.

PubMed

Arshad, Muzamil; Stanley, Jeffrey A; Raz, Naftali

2017-04-01

In an age-heterogeneous sample of healthy adults, we examined test-retest reliability (with and without participant repositioning) of two popular MRI methods of estimating myelin content: modeling the short spin-spin (T 2 ) relaxation component of multi-echo imaging data and computing the ratio of T 1 -weighted and T 2 -weighted images (T 1 w/T 2 w). Taking the myelin water fraction (MWF) index of myelin content derived from the multi-component T 2 relaxation data as a standard, we evaluate the concurrent and differential validity of T 1 w/T 2 w ratio images. The results revealed high reliability of MWF and T 1 w/T 2 w ratio. However, we found significant correlations of low to moderate magnitude between MWF and the T 1 w/T 2 w ratio in only two of six examined regions of the cerebral white matter. Notably, significant correlations of the same or greater magnitude were observed for T 1 w/T 2 w ratio and the intermediate T 2 relaxation time constant, which is believed to reflect differences in the mobility of water between the intracellular and extracellular compartments. We conclude that although both methods are highly reliable and thus well-suited for longitudinal studies, T 1 w/T 2 w ratio has low criterion validity and may be not an optimal index of subcortical myelin content. Hum Brain Mapp 38:1780-1790, 2017. © 2017 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Heart of Great Teaching: Pearson Global Survey of Educator Effectiveness

ERIC Educational Resources Information Center

McKnight, Katherine; Graybeal, John; Yarbro, Jessica; Graybeal, Lacey

2016-01-01

To contribute to the global discussion about what makes an effective teacher, Pearson surveyed students ages 15-19, teachers, principals, education researchers, education policymakers, and parents of school-aged children in 23 countries (Canada, U.S., Mexico, Brazil, Argentina, Finland, Germany, Poland, England, Morocco, Egypt, South Africa,…

Correlation of cancer stem cell markers and immune cell markers in resected non-small cell lung cancer.

PubMed

Huang, Zhaoqin; Yu, Haining; Zhang, Jianbo; Jing, Haiyan; Zhu, Wanqi; Li, Xiaolin; Kong, Lingling; Xing, Ligang; Yu, Jinming; Meng, Xiangjiao

2017-01-01

Background: Recent studies confirmed that immunotherapy showed prominent efficacy in non-small cell lung cancer (NSCLC). Cancer stem cells/cancer initiating cells are resistant to anticancer treatment. The purpose of the study was to analyze the correlation of cancer stem cells/cancer initiating cells and tumor-infiltrating immune cells in NSCLC. Methods: CD133, octamer 4 (OCT-4), CD8, CD56, human leukocyte antigen (HLA) class I and programmed death ligand-1 (PD-L1) were assessed in 172 resected NSCLC samples. The staining was analyzed and scored by the pathologist who was blinded to the clinical pathological data of the patients. Results: High CD8+ T cell infiltration was correlated significantly with squamous cell carcinoma histology (p=0.008). High PD-L1 expression (≥10%) was associated with high tumor status (p=0.043). Pearson's correlation test showed that CD56+ cells were negatively correlated with CD133 expression (r=-0.361, p<0.001) and weakly correlated with negative OCT-4 expression (r=-0.180, p=0.018). There was a strong positive correlation between CD8 and HLA class I (r=0.573, p<0.001). In the survival analysis, high CD8+ T cell infiltration is an independent predictor of improved disease-free survival and overall survival. Patients with low CD133 expression and high CD56 expression had a longer overall survival than those with high CD133 expression and/or low CD56 expression (p=0.013). Conclusion: There is a negative correlation between CD56+ cells and cancer stem cell markers. This correlation may confirm the possibility that natural killer cells can target CD133+ cancer stem cells/cancer initiating cells in non-small cell lung cancer.

Test-retest reliability of the irrational performance beliefs inventory.

PubMed

Turner, M J; Slater, M J; Dixon, J; Miller, A

2018-02-01

The irrational performance beliefs inventory (iPBI) was developed to measure irrational beliefs within performance domains such as sport, academia, business, and the military. Past research indicates that the iPBI has good construct, concurrent, and predictive validity, but the test-retest reliability of the iPBI has not yet been examined. Therefore, in the present study the iPBI was administered to university sport and exercise students (n = 160) and academy soccer athletes (n = 75) at three-time points. Time point two occurred 7 days after time point one, and time point three occurred 21 days after time point two. In addition, social desirability was also measured. Repeated-measures MANCOVAs, intra-class coefficients, and Pearson's (r) correlations demonstrate that the iPBI has good test-retest reliability, with iPBI scores remaining stable across the three-time points. Pearson's correlation coefficients revealed no relationships between the iPBI and social desirability, indicating that the iPBI is not highly susceptible to response bias. The results are discussed with reference to the continued usage and development of the iPBI, and future research recommendations relating to the investigation of irrational performance beliefs are proposed.

Incidental Findings in Abdominal Dual-Energy Computed Tomography: Correlation Between True Noncontrast and Virtual Noncontrast Images Considering Renal and Liver Cysts and Adrenal Masses.

PubMed

Slebocki, Karin; Kraus, Bastian; Chang, De-Hua; Hellmich, Martin; Maintz, David; Bangard, Christopher

To assess correlation between attenuation measurements of incidental findings in abdominal second generation dual-energy computed tomography (CT) on true noncontrast (TNC) and virtual noncontrast (VNC) images. Sixty-three patients underwent arterial dual-energy CT (Somatom Definition Flash, Siemens; pitch factor, 0.75-1.0; gantry rotation time, 0.28 seconds) after endovascular aneurysm repair, consisting of a TNC single energy CT scan (collimation, 128 × 0.6 mm; 120 kVp) and a dual-energy arterial phase scan (collimation, 32 × 0.6 mm, 140 and 100 kVp; blended, 120 kVp data set). Attenuation measurements in Hounsfield units (HU) of liver parenchyma and incidental findings like renal and hepatic cysts and adrenal masses on TNC and VNC images were done by drawing regions of interest. Statistical analysis was performed by paired t test and Pearson correlation. Incidental findings were detected in 56 (89%) patients. There was excellent correlation for both renal (n = 40) and hepatic cysts (n = 12) as well as adrenal masses (n = 6) with a Pearson correlation of 0.896, 0.800, and 0.945, respectively, and mean attenuation values on TNC and VNC images of 10.6 HU ± 12.8 versus 5.1 HU ± 17.5 (attenuation value range from -8.8 to 59.1 HU vs -11.8 to 73.4 HU), 6.4 HU ± 5.8 versus 6.3 HU ± 4.6 (attenuation value range from 2.0 to 16.2 HU vs -3.0 to 15.9 HU), and 12.8 HU ± 11.2 versus 12.4 HU ± 10.2 (attenuation value range from -2.3 to 27.5 HU vs -2.2 to 23.6 HU), respectively. As proof of principle, liver parenchyma measurements also showed excellent correlation between TNC and VNC (n = 40) images with a Pearson correlation of 0.839 and mean attenuation values on TNC and VNC images of 47.2 HU ± 10.5 versus 43.8 HU ± 8.7 (attenuation value range from 21.9 to 60.2 HU vs 4.5 to 65.3 HU). In conclusion, attenuation measurements of incidental findings like renal cysts or adrenal masses on TNC and VNC images derived from second generation dual-energy CT scans show excellent

Reverend Doctor William Pearson in South Kilworth, Leicestershire

NASA Astrophysics Data System (ADS)

Frost, M. A.

2006-12-01

William Pearson (1767-1847) was a 19th-century astronomer, renowned for his work in positional astronomy and the design of astronomical instruments, both practical and instructional. He was a co-founder in 1820 of the Astronomical Society of London, which later became the Royal Astronomical Society, where his portrait hangs. For 30 years of his astronomical career he was the Rector of South Kilworth, a village in Leicestershire, England, where he erected several observatory buildings, as well as extending the village church and building the village schoolroom. This paper documents his activities in South Kilworth.

Several submaximal exercise tests are reliable, valid and acceptable in people with chronic pain, fibromyalgia or chronic fatigue: a systematic review.

PubMed

Ratter, Julia; Radlinger, Lorenz; Lucas, Cees

2014-09-01

Are submaximal and maximal exercise tests reliable, valid and acceptable in people with chronic pain, fibromyalgia and fatigue disorders? Systematic review of studies of the psychometric properties of exercise tests. People older than 18 years with chronic pain, fibromyalgia and chronic fatigue disorders. Studies of the measurement properties of tests of physical capacity in people with chronic pain, fibromyalgia or chronic fatigue disorders were included. Studies were required to report: reliability coefficients (intraclass correlation coefficient, alpha reliability coefficient, limits of agreements and Bland-Altman plots); validity coefficients (intraclass correlation coefficient, Spearman's correlation, Kendal T coefficient, Pearson's correlation); or dropout rates. Fourteen studies were eligible: none had low risk of bias, 10 had unclear risk of bias and four had high risk of bias. The included studies evaluated: Åstrand test; modified Åstrand test; Lean body mass-based Åstrand test; submaximal bicycle ergometer test following another protocol other than Åstrand test; 2-km walk test; 5-minute, 6-minute and 10-minute walk tests; shuttle walk test; and modified symptom-limited Bruce treadmill test. None of the studies assessed maximal exercise tests. Where they had been tested, reliability and validity were generally high. Dropout rates were generally acceptable. The 2-km walk test was not recommended in fibromyalgia. Moderate evidence was found for reliability, validity and acceptability of submaximal exercise tests in patients with chronic pain, fibromyalgia or chronic fatigue. There is no evidence about maximal exercise tests in patients with chronic pain, fibromyalgia and chronic fatigue. Copyright © 2014. Published by Elsevier B.V.

Correlation between plasma homocysteine levels and craving in alcohol dependent stabilized patients.

PubMed

Coppola, Maurizio; Mondola, Raffaella

2018-06-01

Homocysteine is a sulfur amino acid strictly related with alcohol consumption. In alcoholics, hyperhomocysteinemia can increase the risk of various alcohol-related disorders such as: brain atrophy, epileptic seizures during withdrawal, and mood disorders. To evaluate the correlation among serum homocysteine concentrations, craving, hazardous and harmful patterns of alcohol consumption in patients stabilized for withdrawal symptoms. Participants were adult outpatients accessed at the Addiction Treatment Unit. Alcoholism was assessed using the following tools: Mini-International Neuropsychiatric Interview Plus (MINI Plus), Alcohol Use Disorder Identification test (AUDIT), Visual Analogic Scale for craving (VAS). Furthermore, during the first visit a blood sample was taken from all patients to measure the plasma concentration of both homocysteine and Carboxy Deficient Transferrin (CDT). Differences between groups in socio-demographic and clinical characteristics were analyzed using the t-test and the Mann-Whitney's U test for normally and non-normally distributed data, respectively. Correlation between clinical scale scores and plasma concentration of homocysteine and CDT was evaluated using the Pearson's correlation coefficient and the Kendall's Tau-b bivariate correlation coefficient for normally and non-normally distributed data, respectively. Our study included 92 patients. No difference was found in socio-demographic characteristics between groups. The group with high homocysteine had higher prevalence of mood disorders (p < 0.001), plasma CDT percentage (p < 0.001), VAS score (p < 0.001) and AUDIT score (p < 0.001) than group with normal homocysteine. Plasma homocysteine showed a positive correlation with both VAS score (p < 0.001), and AUDIT score (p < 0.05). In our study, plasma homocysteine concentration is associated with craving, hazardous and harmful patterns of alcohol consumption. In particular, homocysteine is correlated with alcoholism in a

Correlation between performance in physics and prior mathematics knowledge

NASA Astrophysics Data System (ADS)

Hudson, H. T.; Rottmann, Ray M.

The final grade of 1403 students enrolled in the first semester of the introductory, pre-professional physics course has been correlated with performance on a precourse diagnostic test of mathematical skills. The students were from a total of eight different sections taught by six separate instructors over a three year time span. The student population has been separated into two groups, those who completed the course (913 students) and those who dropped (490 students). The drops were assigned a projected final gradebased on performance up to date of withdrawal. The Pearson product-moment correlation for students who completed the course is 0.418 and correlation for the drops is 0.232. Both correlations are significant at the p < 0.001 level. This study suggests that prior mathematical ability is a primary influence on performance in the course, and has a secondary influence on the tendency to drop out of the course.

Bisphenol A release from an orthodontic adhesive and its correlation with the degree of conversion on varying light-curing tip distances.

PubMed

Sunitha, Catherine; Kailasam, Vignesh; Padmanabhan, Sridevi; Chitharanjan, Arun B

2011-08-01

The aims of this research were to use high-performance liquid chromatography to assess the bisphenol A (BPA) released from an orthodontic adhesive (Transbond XT; 3M Unitek, Monrovia, Calif) with various light-curing tip distances and to correlate the release to the degree of conversion. One hundred thirty-eight premolar brackets were divided into 3 groups of 40 each for the high-performance liquid chromatography analysis and 3 groups of 6 each for assessing the degree of conversion. Fourier transform infrared spectroscopy was used for this purpose. Each group was studied at light-curing tip distances of 0, 5, and 10 mm. Statistical analyses were performed by using 2-way analysis of variance (ANOVA), post-hoc multiple comparisons Tukey HSD tests, and paired t tests. Pearson correlation was used to assess the correlation between the degree of conversion and BPA release. BPA release was greater in specimens cured with a greater light-curing tip distance. The degree of conversion decreased with increased light-curing tip distances. A negative correlation was found between BPA release and degree of conversion. Clinicians should ensure that the adhesive is completely cured by keeping the light-curing tip as close to the adhesive as clinically possible. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Ninth and Tenth Grade Students' Mathematics Self-Efficacy Beliefs: The Sources and Relationships to Teacher Classroom Interpersonal Behaviors

ERIC Educational Resources Information Center

White, Amanda Garrett

2009-01-01

The purpose of the mix-methods action research study was to seek how the changes in students' perceptions about teacher classroom interpersonal behaviors, the four efficacy sources and mathematics self-efficacy beliefs were related. The methods used to accomplish this were: descriptive statistics, t-test, Pearson correlation coefficient…

Role of Admission Troponin-T and Serial Troponin-T Testing in Predicting Outcomes in Severe Sepsis and Septic Shock.

PubMed

Vallabhajosyula, Saraschandra; Sakhuja, Ankit; Geske, Jeffrey B; Kumar, Mukesh; Poterucha, Joseph T; Kashyap, Rahul; Kashani, Kianoush; Jaffe, Allan S; Jentzer, Jacob C

2017-09-09

Troponin-T elevation is seen commonly in sepsis and septic shock patients admitted to the intensive care unit. We sought to evaluate the role of admission and serial troponin-T testing in the prognostication of these patients. This was a retrospective cohort study from 2007 to 2014 on patients admitted to the intensive care units at the Mayo Clinic with severe sepsis and septic shock. Elevated admission troponin-T and significant delta troponin-T were defined as ≥0.01 ng/mL and ≥0.03 ng/mL in 3 hours, respectively. The primary outcome was in-hospital mortality. Secondary outcomes included 1-year mortality and lengths of stay. During this 8-year period, 944 patients met the inclusion criteria with 845 (90%) having an admission troponin-T ≥0.01 ng/mL. Serial troponin-T values were available in 732 (78%) patients. Elevated admission troponin-T was associated with older age, higher baseline comorbidity, and severity of illness, whereas significant delta troponin-T was associated with higher severity of illness. Admission log 10 troponin-T was associated with unadjusted in-hospital (odds ratio 1.6; P =0.003) and 1-year mortality (odds ratio 1.3; P =0.04), but did not correlate with length of stay. Elevated delta troponin-T and log 10 delta troponin-T were not significantly associated with any of the primary or secondary outcomes. Admission log 10 troponin-T remained an independent predictor of in-hospital mortality (odds ratio 1.4; P =0.04) and 1-year survival (hazard ratio 1.3; P =0.008). In patients with sepsis and septic shock, elevated admission troponin-T was associated with higher short- and long-term mortality. Routine serial troponin-T testing did not add incremental prognostic value in these patients. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

A novel mitochondrial DNA deletion in a patient with Pearson syndrome and neonatal diabetes mellitus provides insight into disease etiology, severity and progression.

PubMed

Chen, Xin-Yu; Zhao, Si-Yu; Wang, Yan; Wang, Dong; Dong, Chang-Hu; Yang, Ying; Wang, Zhi-Hua; Wu, Yuan-Ming

2016-07-01

Pearson syndrome (PS) is a rare, mitochondrial DNA (mtDNA) deletion disorder mainly affecting hematopoietic system and exocrine pancreas in early infancy, which is characterized by multi-organ involvement, variable manifestations and poor prognosis. Since the clinical complexity and uncertain outcome of PS, the ability to early diagnose and anticipate disease progression is of great clinical importance. We described a patient with severe anemia and hyperglycinemia at birth was diagnosed with neonatal diabetes mellitus, and later with PS. Genetic testing revealed that a novel mtDNA deletion existed in various non-invasive tissues from the patient. The disease course was monitored by mtDNA deletion heteroplasmy and mtDNA/nucleus DNA genome ratio in different tissues and at different time points, showing a potential genotype-phenotype correlation. Our findings suggest that for patient suspected for PS, it may be therapeutically important to first perform detailed mtDNA analysis on non-invasive tissues at the initial diagnosis and during disease progression.

Vitamin D Status Is Positively Correlated with Regulatory T Cell Function in Patients with Multiple Sclerosis

PubMed Central

Smolders, Joost; Thewissen, Mariëlle; Peelen, Evelyn; Menheere, Paul; Cohen Tervaert, Jan Willem; Damoiseaux, Jan; Hupperts, Raymond

2009-01-01

Background In several autoimmune diseases, including multiple sclerosis (MS), a compromised regulatory T cell (Treg) function is believed to be critically involved in the disease process. In vitro, the biologically active metabolite of vitamin D has been shown to promote Treg development. A poor vitamin D status has been linked with MS incidence and MS disease activity. In the present study, we assess a potential in vivo correlation between vitamin D status and Treg function in relapsing remitting MS (RRMS) patients. Methodology/Principal Findings Serum levels of 25-hydroxyvitamin D (25(OH)D) were measured in 29 RRMS patients. The number of circulating Tregs was assessed by flow-cytometry, and their functionality was tested in vitro in a CFSE-based proliferation suppression assay. Additionally, the intracellular cytokine profile of T helper cells was determined directly ex-vivo by flow-cytometry. Serum levels of 25(OH)D correlated positively with the ability of Tregs to suppress T cell proliferation (R = 0.590, P = 0.002). No correlation between 25(OH)D levels and the number of Tregs was found. The IFN-γ/IL-4 ratio (Th1/Th2-balance) was more directed towards IL-4 in patients with favourable 25(OH)D levels (R = −0.435, P = 0.023). Conclusions/Significance These results show an association of high 25(OH)D levels with an improved Treg function, and with skewing of the Th1/Th2 balance towards Th2. These findings suggest that vitamin D is an important promoter of T cell regulation in vivo in MS patients. It is tempting to speculate that our results may not only hold for MS, but also for other autoimmune diseases. Future intervention studies will show whether modulation of vitamin D status results in modulation of the T cell response and subsequent amelioration of disease activity. PMID:19675671

Myocardial effective transverse relaxation time T2* Correlates with left ventricular wall thickness: A 7.0 T MRI study.

PubMed

Huelnhagen, Till; Hezel, Fabian; Serradas Duarte, Teresa; Pohlmann, Andreas; Oezerdem, Celal; Flemming, Bert; Seeliger, Erdmann; Prothmann, Marcel; Schulz-Menger, Jeanette; Niendorf, Thoralf

2017-06-01

Myocardial effective relaxation time T2* is commonly regarded as a surrogate for myocardial tissue oxygenation. However, it is legitimate to assume that there are multiple factors that influence T2*. To this end, this study investigates the relationship between T2* and cardiac macromorphology given by left ventricular (LV) wall thickness and left ventricular radius, and provides interpretation of the results in the physiological context. High spatio-temporally resolved myocardial CINE T2* mapping was performed in 10 healthy volunteers using a 7.0 Tesla (T) full-body MRI system. Ventricular septal wall thickness, left ventricular inner radius, and T2* were analyzed. Macroscopic magnetic field changes were elucidated using cardiac phase-resolved magnetic field maps. Ventricular septal T2* changes periodically over the cardiac cycle, increasing in systole and decreasing in diastole. Ventricular septal wall thickness and T2* showed a significant positive correlation, whereas the inner LV radius and T2* were negatively correlated. The effect of macroscopic magnetic field gradients on T2* can be considered minor in the ventricular septum. Our findings suggest that myocardial T2* is related to tissue blood volume fraction. Temporally resolved T2* mapping could be beneficial for myocardial tissue characterization and for understanding cardiac (patho)physiology in vivo. Magn Reson Med 77:2381-2389, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Specific Features of Executive Dysfunction in Alzheimer-Type Mild Dementia Based on Computerized Cambridge Neuropsychological Test Automated Battery (CANTAB) Test Results.

PubMed

Kuzmickienė, Jurgita; Kaubrys, Gintaras

2016-10-08

BACKGROUND The primary manifestation of Alzheimer's disease (AD) is decline in memory. Dysexecutive symptoms have tremendous impact on functional activities and quality of life. Data regarding frontal-executive dysfunction in mild AD are controversial. The aim of this study was to assess the presence and specific features of executive dysfunction in mild AD based on Cambridge Neuropsychological Test Automated Battery (CANTAB) results. MATERIAL AND METHODS Fifty newly diagnosed, treatment-naïve, mild, late-onset AD patients (MMSE ≥20, AD group) and 25 control subjects (CG group) were recruited in this prospective, cross-sectional study. The CANTAB tests CRT, SOC, PAL, SWM were used for in-depth cognitive assessment. Comparisons were performed using the t test or Mann-Whitney U test, as appropriate. Correlations were evaluated by Pearson r or Spearman R. Statistical significance was set at p<0.05. RESULTS AD and CG groups did not differ according to age, education, gender, or depression. Few differences were found between groups in the SOC test for performance measures: Mean moves (minimum 3 moves): AD (Rank Sum=2227), CG (Rank Sum=623), p<0.001. However, all SOC test time measures differed significantly between groups: SOC Mean subsequent thinking time (4 moves): AD (Rank Sum=2406), CG (Rank Sum=444), p<0.001. Correlations were weak between executive function (SOC) and episodic/working memory (PAL, SWM) (R=0.01-0.38) or attention/psychomotor speed (CRT) (R=0.02-0.37). CONCLUSIONS Frontal-executive functions are impaired in mild AD patients. Executive dysfunction is highly prominent in time measures, but minimal in performance measures. Executive disorders do not correlate with a decline in episodic and working memory or psychomotor speed in mild AD.

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor.

PubMed

Kim, Hyo Jung; Park, Seong Ho; Kim, Ji Soo; Koo, Ja Won; Kim, Chae Yong; Kim, Young Hoon; Han, Jung Ho

2016-01-01

Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor. Twenty-eight patients (21 women; age=64±12 years, mean±SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification. Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction. Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion.

PubMed

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune; Kim, Tae Kyun

2016-06-01

Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA.

Active Flexion in Weight Bearing Better Correlates with Functional Outcomes of Total Knee Arthroplasty than Passive Flexion

PubMed Central

Song, Young Dong; Jain, Nimash; Kang, Yeon Gwi; Kim, Tae Yune

2016-01-01

Purpose Correlations between maximum flexion and functional outcomes in total knee arthroplasty (TKA) patients are reportedly weak. We investigated whether there are differences between passive maximum flexion in nonweight bearing and other types of maximum flexion and whether the type of maximum flexion correlates with functional outcomes. Materials and Methods A total of 210 patients (359 knees) underwent preoperative evaluation and postoperative follow-up evaluations (6, 12, and 24 months) for the assessment of clinical outcomes including maximum knee flexion. Maximum flexion was measured under five conditions: passive nonweight bearing, passive weight bearing, active nonweight bearing, and active weight bearing with or without arm support. Data were analyzed for relationships between passive maximum flexion in nonweight bearing by Pearson correlation analyses, and a variance comparison between measurement techniques via paired t test. Results We observed substantial differences between passive maximum flexion in nonweight bearing and the other four maximum flexion types. At all time points, passive maximum flexion in nonweight bearing correlated poorly with active maximum flexion in weight bearing with or without arm support. Active maximum flexion in weight bearing better correlated with functional outcomes than the other maximum flexion types. Conclusions Our study suggests active maximum flexion in weight bearing should be reported together with passive maximum flexion in nonweight bearing in research on the knee motion arc after TKA. PMID:27274468

Correlation of United States Medical Licensing Examination and Internal Medicine In-Training Examination performance.

PubMed

Perez, Jose A; Greer, Sharon

2009-12-01

The Internal Medicine In-Training Examination (ITE) is administered during residency training in the United States as a self-assessment and program assessment tool. Performance on this exam correlates with outcome on the American Board of Internal Medicine Certifying examination. Internal Medicine Program Directors use the United States Medical Licensing Examination (USMLE) to make decisions in recruitment of potential applicants. This study was done to determine a correlation of USMLE Steps 1, 2 and 3 results with ITE scores in each level of Internal Medicine training. A retrospective review of all residents graduating from an Internal Medicine program from 1999 to 2006 was done. Subjects included had data for all USMLE Steps and ITE during all years of training. Thirty-one subjects were included in the study. Correlations of USMLE Steps 1, 2 and 3 were done with ITE scores (percent correct) in each year of training. Pearson's correlation coefficient (r) was determined for each pairing and a t test to determine statistical significance of the correlation was done. Statistical significance was defined as P value <0.05. The r values for USMLE Step 1 and ITE percent correct in PGY I, II and III were 0.46, 0.55 and 0.51 respectively. Corresponding r values for USMLE Step 2 and ITE percent correct were 0.79, 0.70 and 0.72; for USMLE Step 3 these values were 0.51, 0.37 and 0.51 respectively for each training year. USMLE scores are correlated with ITE scores. This correlation was strongest for USMLE Step 2.

Differentiation of Trypanosoma brucei, T. rhodesiense, and T. gambiense by the indirect fluorescent antibody test

PubMed Central

Latif, B. M. A.; Adam, Katherine M. G.

1973-01-01

Epidemiological studies, if they are to lead to appropriate preventive procedures, require knowledge of the host distribution of the parasite. Progress in the epidemiology of African trypanosomiasis is restricted by the lack of a reliable and simple method of differentiating Trypanosoma brucei, T. rhodesiense, and T. gambiense. The recently introduced blood inoculation infectivity test promises to fulfil this need by distinguishing T. brucei from T. rhodesiense, but it would not be suitable for separating T. brucei from T. gambiense, since rats and mice are frequently refractory to infection by fresh isolates of T. gambiense. Previous studies had indicated that the indirect fluorescent antibody test might differentiate not only the subgenera of the salivarian trypanosome species but also members of the subgenus Trypanozoon. A method of performing the test is described that enables T. brucei, T. rhodesiense, and T. gambiense to be differentiated by the titre of the sera. The method might be used in conjunction with the blood inoculation infectivity test to distinguish between new isolates of the subgenus Trypanozoon in East Africa, and also to search for possible animal reservoirs of T. gambiense in West Africa. PMID:4587481

Why Waveform Correlation Sometimes Fails

NASA Astrophysics Data System (ADS)

Carmichael, J.

2015-12-01

Waveform correlation detectors used in explosion monitoring scan noisy geophysical data to test two competing hypotheses: either (1) an amplitude-scaled version of a template waveform is present, or, (2) no signal is present at all. In reality, geophysical wavefields that are monitored for explosion signatures include waveforms produced by non-target sources that are partially correlated with the waveform template. Such signals can falsely trigger correlation detectors, particularly at low thresholds required to monitor for smaller target explosions. This challenge is particularly formidable when monitoring known test sites for seismic disturbances, since uncatalogued natural seismicity is (generally) more prevalent at lower magnitudes, and could be mistaken for small explosions. To address these challenges, we identify real examples in which correlation detectors targeting explosions falsely trigger on both site-proximal earthquakes (Figure 1, below) and microseismic "noise". Motivated by these examples, we quantify performance loss when applying these detectors, and re-evaluate the correlation-detector's hypothesis test. We thereby derive new detectors from more general hypotheses that admit unknown background seismicity, and apply these to real data. From our treatment, we derive "rules of thumb'' for proper template and threshold selection in heavily cluttered signal environments. Last, we answer the question "what is the probability of falsely detecting an earthquake collocated at a test site?", using correlation detectors that include explosion-triggered templates. Figure Top: An eight-channel data stream (black) recorded from an earthquake near a mine. Red markers indicate a detection. Middle: The correlation statistic computed by scanning the template against the data stream at top. The red line indicates the threshold for event declaration, determined by a false-alarm on noise probability constraint, as computed from the signal-absent distribution using

Correlation tests of the engine performance parameter by using the detrended cross-correlation coefficient

NASA Astrophysics Data System (ADS)

Dong, Keqiang; Gao, You; Jing, Liming

2015-02-01

The presence of cross-correlation in complex systems has long been noted and studied in a broad range of physical applications. We here focus on an aero-engine system as an example of a complex system. By applying the detrended cross-correlation (DCCA) coefficient method to aero-engine time series, we investigate the effects of the data length and the time scale on the detrended cross-correlation coefficients ρ DCCA ( T, s). We then show, for a twin-engine aircraft, that the engine fuel flow time series derived from the left engine and the right engine exhibit much stronger cross-correlations than the engine exhaust-gas temperature series derived from the left engine and the right engine do.

The Correlation of Cognitive and Psychomotor Tests

DTIC Science & Technology

1992-09-01

a measure of association and was developed in its current form by Karl Pearson. He built upon the work of Sir Francis Galton who conceived of the...Sir Francis Galton who conceived of the idea and on the mathematical formulations of the product-moment of the Austrian mathematician, Bravis...is not unitary, but there’s more to the story: Comment on Kranzler and Jensen. Intelligence , 15, 423-436. Cronbach, L J. (1970). Essentials of

Correlational structure of 'frontal' tests and intelligence tests indicates two components with asymmetrical neurostructural correlates in old age.

PubMed

Cox, Simon R; MacPherson, Sarah E; Ferguson, Karen J; Nissan, Jack; Royle, Natalie A; MacLullich, Alasdair M J; Wardlaw, Joanna M; Deary, Ian J

2014-09-01

Both general fluid intelligence ( g f ) and performance on some 'frontal tests' of cognition decline with age. Both types of ability are at least partially dependent on the integrity of the frontal lobes, which also deteriorate with age. Overlap between these two methods of assessing complex cognition in older age remains unclear. Such overlap could be investigated using inter-test correlations alone, as in previous studies, but this would be enhanced by ascertaining whether frontal test performance and g f share neurobiological variance. To this end, we examined relationships between g f and 6 frontal tests (Tower, Self-Ordered Pointing, Simon, Moral Dilemmas, Reversal Learning and Faux Pas tests) in 90 healthy males, aged ~ 73 years. We interpreted their correlational structure using principal component analysis, and in relation to MRI-derived regional frontal lobe volumes (relative to maximal healthy brain size). g f correlated significantly and positively (.24 ≤  r  ≤ .53) with the majority of frontal test scores. Some frontal test scores also exhibited shared variance after controlling for g f . Principal component analysis of test scores identified units of g f -common and g f -independent variance. The former was associated with variance in the left dorsolateral (DL) and anterior cingulate (AC) regions, and the latter with variance in the right DL and AC regions. Thus, we identify two biologically-meaningful components of variance in complex cognitive performance in older age and suggest that age-related changes to DL and AC have the greatest cognitive impact.

PROMIS Physical Function Correlation With NDI and mJOA in the Surgical Cervical Myelopathy Patient Population.

PubMed

Owen, Robert J; Zebala, Lukas P; Peters, Colleen; McAnany, Steven

2018-04-15

Retrospective review. To determine the correlation of Patient-Reported Outcomes Measurement Information System (PROMIS) physical function with Neck Disability Index (NDI) and Modified Japanese Orthopedic Association (mJOA) scores in the surgical cervical myelopathy patient population. Outcome measures such as NDI and mJOA are essential for analyzing treatments for cervical myelopathy. Administrative burdens impose limits on completion of these measures. The PROMIS group developed an outcome measure to improve reporting of patient symptoms and function and to reduce administrative burden. Despite early success, NDI and mJOA have not been compared with PROMIS in patients with cervical myelopathy. This study determines the correlation of NDI and mJOA with PROMIS in surgical patients with cervical myelopathy. A total of 60 patients with cervical myelopathy undergoing surgery were included. PROMIS, NDI, and mJOA were collected preoperatively, and in the first 6 months postoperatively. Correlations between NDI, mJOA, and PROMIS were quantified using Pearson correlation coefficients. Students t tests were used to test significance. All 60 (100%) of patients completed preoperative questionnaires. Fifty-five (92%) of patients completed initial follow-up questionnaires within the first 6 months. PROMIS physical function and NDI demonstrated a strong negative correlation at baseline and in initial follow-up (R = -0.69, -0.76). PROMIS and mJOA demonstrated a strong positive correlation at baseline and in initial follow-up (R = 0.61, 0.72). PROMIS physical function has a strong negative correlation with NDI and a strong positive correlation with mJOA at baseline and in the early postoperative course in patients undergoing surgery for cervical myelopathy. Surgeons may factor these outcomes into the delivery and interpretation of patient-reported outcome measures in this population. Use of PROMIS may improve completion of outcome measures in the office and reduce

An invariance property of generalized Pearson random walks in bounded geometries

NASA Astrophysics Data System (ADS)

Mazzolo, Alain

2009-03-01

Invariance properties of random walks in bounded domains are a topic of growing interest since they contribute to improving our understanding of diffusion in confined geometries. Recently, limited to Pearson random walks with exponentially distributed straight paths, it has been shown that under isotropic uniform incidence, the average length of the trajectories through the domain is independent of the random walk characteristic and depends only on the ratio of the volume's domain over its surface. In this paper, thanks to arguments of integral geometry, we generalize this property to any isotropic bounded stochastic process and we give the conditions of its validity for isotropic unbounded stochastic processes. The analytical form for the traveled distance from the boundary to the first scattering event that ensures the validity of the Cauchy formula is also derived. The generalization of the Cauchy formula is an analytical constraint that thus concerns a very wide range of stochastic processes, from the original Pearson random walk to a Rayleigh distribution of the displacements, covering many situations of physical importance.

Genome-scale cluster analysis of replicated microarrays using shrinkage correlation coefficient.

PubMed

Yao, Jianchao; Chang, Chunqi; Salmi, Mari L; Hung, Yeung Sam; Loraine, Ann; Roux, Stanley J

2008-06-18

Currently, clustering with some form of correlation coefficient as the gene similarity metric has become a popular method for profiling genomic data. The Pearson correlation coefficient and the standard deviation (SD)-weighted correlation coefficient are the two most widely-used correlations as the similarity metrics in clustering microarray data. However, these two correlations are not optimal for analyzing replicated microarray data generated by most laboratories. An effective correlation coefficient is needed to provide statistically sufficient analysis of replicated microarray data. In this study, we describe a novel correlation coefficient, shrinkage correlation coefficient (SCC), that fully exploits the similarity between the replicated microarray experimental samples. The methodology considers both the number of replicates and the variance within each experimental group in clustering expression data, and provides a robust statistical estimation of the error of replicated microarray data. The value of SCC is revealed by its comparison with two other correlation coefficients that are currently the most widely-used (Pearson correlation coefficient and SD-weighted correlation coefficient) using statistical measures on both synthetic expression data as well as real gene expression data from Saccharomyces cerevisiae. Two leading clustering methods, hierarchical and k-means clustering were applied for the comparison. The comparison indicated that using SCC achieves better clustering performance. Applying SCC-based hierarchical clustering to the replicated microarray data obtained from germinating spores of the fern Ceratopteris richardii, we discovered two clusters of genes with shared expression patterns during spore germination. Functional analysis suggested that some of the genetic mechanisms that control germination in such diverse plant lineages as mosses and angiosperms are also conserved among ferns. This study shows that SCC is an alternative to the Pearson

Correlation of diffusion and perfusion MRI with Ki-67 in high-grade meningiomas.

PubMed

Ginat, Daniel T; Mangla, Rajiv; Yeaney, Gabrielle; Wang, Henry Z

2010-12-01

Atypical and anaplastic meningiomas have a greater likelihood of recurrence than benign meningiomas. The risk for recurrence is often estimated using the Ki-67 labeling index. The purpose of this study was to determine the correlation between Ki-67 and regional cerebral blood volume (rCBV) and between Ki-67 and apparent diffusion coefficient (ADC) in atypical and anaplastic meningiomas. A retrospective review of the advanced imaging and immunohistochemical characteristics of atypical and anaplastic meningiomas was performed. The relative minimum ADC, relative maximum rCBV, and specimen Ki-67 index were measured. Pearson's correlation was used to compare these parameters. There were 23 cases with available ADC maps and 20 cases with available rCBV maps. The average Ki-67 among the cases with ADC maps and rCBV maps was 17.6% (range, 5-38%) and 16.7% (range, 3-38%), respectively. The mean minimum ADC ratio was 0.91 (SD, 0.26) and the mean maximum rCBV ratio was 22.5 (SD, 7.9). There was a significant positive correlation between maximum rCBV and Ki-67 (Pearson's correlation, 0.69; p = 0.00038). However, there was no significant correlation between minimum ADC and Ki-67 (Pearson's correlation, -0.051; p = 0.70). Maximum rCBV correlated significantly with Ki-67 in high-grade meningiomas.

The Relationship between English Language Proficiency, Academic Achievement and Self-Esteem of Non-Native-English-Speaking Students

ERIC Educational Resources Information Center

Dev, Smitha; Qiqieh, Sura

2016-01-01

The present study aims to find out the relationship between English Language proficiency, self-esteem, and academic achievement of the students in Abu Dhabi University (ADU). The variables were analyzed using "t" test, chi-squire and Pearson's product moment correlation. In addition, Self-rating scale, Self-esteem inventory and Language…

Correlation of the near-infrared spectroscopy signals with signal intensity in T(2)-weighted magnetic resonance imaging of the human masseter muscle.

PubMed

Kuboki, T; Suzuki, K; Maekawa, K; Inoue-Minakuchi, M; Acero, C O; Yanagi, Y; Wakasa, T; Kishi, K; Yatani, H; Clark, G T

2001-08-01

The purpose of this study was to compare and contrast blood volume changes transcutaneously measured using near-infrared (NIR) spectroscopy against water signal intensity changes taken from a transverse T(2)-weighted MR image of the masseter muscle in healthy human subjects before, during and after contraction. Eight healthy non-smoking males with no history of chronic muscle pain or vascular headaches participated (mean age: 23.9+/-0.6 years). The MRI data were gathered using a turbo spin echo sequence (TR: 2300 ms; TE: 90 ms; FOV: 188x300 mm; scanning time: 30 s; slice thickness: 10 mm) and the slice level was set at the mid-point between the origin and insertion of the masseter. Intramuscular haemoglobin (Hb) levels and water content of the right masseter muscle were continuously monitored for 2 min before, 30 s during and 15 min after a maximum voluntary clenching (MVC) task. Both the near-infrared and MRI data were baseline-corrected and normalized and mean levels were established and plotted. Plots of the data showed that both near-infrared-based total Hb and T(2)-weighted MRI-based signal-intensity levels clearly decreased during contraction and a clear post-contraction rebound response was evident after the contraction. The near-infrared data were found to be highly correlated with MRI-based signal-intensity data (Pearson's r=0.909, P<0.0001). In conclusion, these data provide powerful evidence that near-infrared data (total Hb), transcutaneously taken from the masseter muscle in humans, will reflect the intramuscular water signal intensity changes seen using a T(2)-weighted MRI imaging method.

Test wells T23, T29, and T30, White Sands Missile Range and Fort Bliss Military Reservation, Dona Ana County, New Mexico

USGS Publications Warehouse

Myers, R.G.; Pinckley, K.M.

1984-01-01

Three test wells, T23, T29, and T30, were drilled in south-central New Mexico as part of a joint military training program sponsored by the U.S. Army in November 1982. Test well T23 was drilled as an exploratory and monitoring well in the proposed Soledad well field at the Fort Bliss Military Reservation. Test wells T29 and T30 were drilled at White Sands Missile Range. Test well T29 was drilled as an observation well in the vicinity of the outfall channel from the sewage treatment plant. Test well T30 was drilled as an observation well for a landfill south of the well site. Information obtained from these wells includes lithologic logs for all wells and borehole-geophysical logs from the cased wells for test wells T29 and T30. (USGS)

Comparison between Standing Broad Jump test and Wingate test for assessing lower limb anaerobic power in elite sportsmen.

PubMed

Krishnan, Anup; Sharma, Deep; Bhatt, Madhu; Dixit, Apoorv; Pradeep, P

2017-04-01

Lower limb explosive power is an important motor quality for sporting performance and indicates use of anaerobic energy systems like stored ATP and Creatine phosphate system. Weightlifting, Fencing and Wrestling use it for monitoring and identification of potential sportsmen. The Wingate test and Standing Broad Jump (SBJ) test are reliable and accurate tests for its assessment. This study conducted on elite Indian sportsmen tries to analyse feasibility of use of the SBJ test in sports and military medicine when Wingate test is impractical. 95 elite sportsmen (51 Fencers, 17 Weight lifters and 27 Wrestlers) of a sports institute were administered Wingate cycle ergometer test and SBJ under standardised conditions. The results were analysed for mass and inter-discipline correlation. Analysis using Pearson's correlation showed significant positive correlation between Peak power ( r  = 0.446, p  < 0.0001) and SBJ (distance) in all sportsmen. Inter-sport correlation showed positive correlation between SBJ and peak power ( r  = 0.335, p  < 0.016) in Fencers and between SBJ, peak power ( r  = 0.686, p  < 0.002) in Weightlifters. Bland-Altman plot analysis showed that about 94% pairs of peak power and SBJ were within limits of agreement for each discipline as well as among all sportsmen. The test results show definite correlation and SBJ test can be used as a field test in performance monitoring, talent identification, military recruit screening and injury prevention.

Quantized correlation coefficient for measuring reproducibility of ChIP-chip data.

PubMed

Peng, Shouyong; Kuroda, Mitzi I; Park, Peter J

2010-07-27

Chromatin immunoprecipitation followed by microarray hybridization (ChIP-chip) is used to study protein-DNA interactions and histone modifications on a genome-scale. To ensure data quality, these experiments are usually performed in replicates, and a correlation coefficient between replicates is used often to assess reproducibility. However, the correlation coefficient can be misleading because it is affected not only by the reproducibility of the signal but also by the amount of binding signal present in the data. We develop the Quantized correlation coefficient (QCC) that is much less dependent on the amount of signal. This involves discretization of data into set of quantiles (quantization), a merging procedure to group the background probes, and recalculation of the Pearson correlation coefficient. This procedure reduces the influence of the background noise on the statistic, which then properly focuses more on the reproducibility of the signal. The performance of this procedure is tested in both simulated and real ChIP-chip data. For replicates with different levels of enrichment over background and coverage, we find that QCC reflects reproducibility more accurately and is more robust than the standard Pearson or Spearman correlation coefficients. The quantization and the merging procedure can also suggest a proper quantile threshold for separating signal from background for further analysis. To measure reproducibility of ChIP-chip data correctly, a correlation coefficient that is robust to the amount of signal present should be used. QCC is one such measure. The QCC statistic can also be applied in a variety of other contexts for measuring reproducibility, including analysis of array CGH data for DNA copy number and gene expression data.

Applying standardized uptake values in gallium-67-citrate single-photon emission computed tomography/computed tomography studies and their correlation with blood test results in representative organs.

PubMed

Toriihara, Akira; Daisaki, Hiromitsu; Yamaguchi, Akihiro; Yoshida, Katsuya; Isogai, Jun; Tateishi, Ukihide

2018-05-21

Recently, semiquantitative analysis using standardized uptake value (SUV) has been introduced in bone single-photon emission computed tomography/computed tomography (SPECT/CT). Our purposes were to apply SUV-based semiquantitative analytic method for gallium-67 (Ga)-citrate SPECT/CT and to evaluate correlation between SUV of physiological uptake and blood test results in representative organs. The accuracy of semiquantitative method was validated using an National Electrical Manufacturers Association body phantom study (radioactivity ratio of sphere : background=4 : 1). Thereafter, 59 patients (34 male and 25 female; mean age, 66.9 years) who had undergone Ga-citrate SPECT/CT were retrospectively enrolled in the study. A mean SUV of physiological uptake was calculated for the following organs: the lungs, right atrium, liver, kidneys, spleen, gluteal muscles, and bone marrow. The correlation between physiological uptakes and blood test results was evaluated using Pearson's correlation coefficient. The phantom study revealed only 1% error between theoretical and actual SUVs in the background, suggesting the sufficient accuracy of scatter and attenuation corrections. However, a partial volume effect could not be overlooked, particularly in small spheres with a diameter of less than 28 mm. The highest mean SUV was observed in the liver (range: 0.44-4.64), followed by bone marrow (range: 0.33-3.60), spleen (range: 0.52-2.12), and kidneys (range: 0.42-1.45). There was no significant correlation between hepatic uptake and liver function, renal uptake and renal function, or bone marrow uptake and blood cell count (P>0.05). The physiological uptake in Ga-citrate SPECT/CT can be represented as SUVs, which are not significantly correlated with corresponding blood test results.

Test-retest reliability of the Clinical Learning Environment, Supervision and Nurse Teacher (CLES + T) scale.

PubMed

Gustafsson, Margareta; Blomberg, Karin; Holmefur, Marie

2015-07-01

The Clinical Learning Environment, Supervision and Nurse Teacher (CLES + T) scale evaluates the student nurses' perception of the learning environment and supervision within the clinical placement. It has never been tested in a replication study. The aim of the present study was to evaluate the test-retest reliability of the CLES + T scale. The CLES + T scale was administered twice to a group of 42 student nurses, with a one-week interval. Test-retest reliability was determined by calculations of Intraclass Correlation Coefficients (ICCs) and weighted Kappa coefficients. Standard Error of Measurements (SEM) and Smallest Detectable Difference (SDD) determined the precision of individual scores. Bland-Altman plots were created for analyses of systematic differences between the test occasions. The results of the study showed that the stability over time was good to excellent (ICC 0.88-0.96) in the sub-dimensions "Supervisory relationship", "Pedagogical atmosphere on the ward" and "Role of the nurse teacher". Measurements of "Premises of nursing on the ward" and "Leadership style of the manager" had lower but still acceptable stability (ICC 0.70-0.75). No systematic differences occurred between the test occasions. This study supports the usefulness of the CLES + T scale as a reliable measure of the student nurses' perception of the learning environment within the clinical placement at a hospital. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationship between the TCAP and the Pearson Benchmark Assessment in Elementary Students' Reading and Math Performance in a Northeastern Tennessee School District

ERIC Educational Resources Information Center

Dugger-Roberts, Cherith A.

2014-01-01

The purpose of this quantitative study was to determine if there was a relationship between the TCAP test and Pearson Benchmark assessment in elementary students' reading and language arts and math performance in a northeastern Tennessee school district. This study involved 3rd, 4th, 5th, and 6th grade students. The study focused on the following…

A shift from significance test to hypothesis test through power analysis in medical research.

PubMed

Singh, G

2006-01-01

Medical research literature until recently, exhibited substantial dominance of the Fisher's significance test approach of statistical inference concentrating more on probability of type I error over Neyman-Pearson's hypothesis test considering both probability of type I and II error. Fisher's approach dichotomises results into significant or not significant results with a P value. The Neyman-Pearson's approach talks of acceptance or rejection of null hypothesis. Based on the same theory these two approaches deal with same objective and conclude in their own way. The advancement in computing techniques and availability of statistical software have resulted in increasing application of power calculations in medical research and thereby reporting the result of significance tests in the light of power of the test also. Significance test approach, when it incorporates power analysis contains the essence of hypothesis test approach. It may be safely argued that rising application of power analysis in medical research may have initiated a shift from Fisher's significance test to Neyman-Pearson's hypothesis test procedure.

Tuberculin skin test and ELISPOT/T. SPOT.TB in children and adolescents with juvenile idiopathic arthritis

PubMed Central

2014-01-01

Background There are controversies regarding the accuracy of the tuberculin skin test (TST) and methods based on the production of interferon gamma by sensitized T cells for the diagnosis of latent tuberculosis infection (LTBI) in pediatrics and immunosuppressed patients. Our objectives are to study TST and ELISPOT/T. SPOT.TB in the diagnosis of LTBI in children and adolescents with JIA undergoing methotrexate, the correlation between both and the sensitivity and specificity of T. SPOT.TB. Methods This is an observational prospective longitudinal study in which children and adolescents with JIA undergoing methotrexate therapy were assessed for clinical and epidemiological data for LTBI, in addition to performing TST and T. SPOT.TB at baseline and after 3 and 12months. Results There were 24 patients. The prevalence of LTBI at inclusion was 20.8%, the incidence after initiation of immunosuppressions 26.3% and the prevalence at the end of the study 41.6%. Epidemiological history positive for TB showed a relative risk of 2.0 for the development of LTBI. Only 2 patients had positive T. SPOT.TB but only in one it was useful for detecting early LTBI. T. SPOT.TB presented a sensitivity of 10%, specificity of 92.8%, and low correlation with TST. No patient developed TB disease at a mean follow-up of 47months. Conclusions We found a high prevalence of ILTB that doubled with immunosuppression and that epidemiological history was an important relative risk. T. SPOT.TB showed low sensitivity and high specificity, and no superiority over TST. There was low agreement and little influence of immunosuppression on the results of both tests. PMID:24904240

[Medical school admission test at the University of Goettingen - which applicants will benefit?].

PubMed

Simmenroth-Nayda, Anne; Meskauskas, Erik; Burckhardt, Gerhard; Görlich, Yvonne

2014-01-01

Medical schools in Germany may select 60% of the student applicants through their own admission tests. The influence of the school-leaving examination grades (EGs) in each of the procedural steps is controversial. At Goettingen Medical School, we combine a structured interview and a communicative skills assessment. We analysed how many applicants succeeded in our admission test, compared to a model which only takes EGs into account. Admission scores were transferred into SPSS-21. Sociodemographic data were submitted by the Stiftung Hochschulstart. Besides descriptive statistics, we used Pearson-correlation and means comparisons (t-test, analysis of variance). 221 applicants (EGs 1.0-1.9) were invited in the winter semester 2013/14 and 222 applicants (EGs 1.1-1.8) in the summer semester 2014. The proportion of women was 68% (winter) and 74% (summer). Sixteen and 37 applicants had a medical vocational training and performed slightly better. The analysis showed that our test was gender neutral. EGs did not correlate with interviews or skills assessment. Despite a two-fold impact of EGs, 26 (winter) and 44 (summer) of the overall 181 applicants had EGs of 1.4 -1.9, which would have been too low for admission otherwise. If EGs were only considered once, 40 (winter) and 59 (summer) applicants would have succeeded. Copyright © 2014. Published by Elsevier GmbH.

[A multicenter study of correlation between peripheral lymphocyte counts and CD(+)4T cell counts in HIV/AIDS patients].

PubMed

Xie, Jing; Qiu, Zhifeng; Han, Yang; Li, Yanling; Song, Xiaojing; Li, Taisheng

2015-02-01

To evaluate the accuracy of lymphocyte count as a surrogate for CD(+)4T cell count in treatment-naїve HIV-infected adults. A total of 2 013 HIV-infected patients were screened at 23 sites in China. CD(+)4T cell counts were measured by flow cytometry. Correlation between CD(+)4T cell count and peripheral lymphocyte count were analyzed by spearman coefficient. AUCROC were used to evaluate the performance of lymphocyte count as a surrogate for CD(+)4T cell count. The lymphocyte count and CD(+)4T cell count of these 2 013 patients were (1 600 ± 670) × 10(6)/L and (244 ± 148) × 10(6)/L respectively. CD(+)4T cell count were positively correlated with lymphocyte count (r = 0.482, P < 0.000 1). AUCROC of lymphocyte count as a surrogate for CD(+)4T cell counts of <100×10(6)/L, <200×10(6)/L and <350×10(6)/L were 0.790 (95%CI 0.761-0.818, P < 0.000 1), 0.733 (95%CI 0.710-0.755, P < 0.000 1) and 0.732 (95%CI 0.706-0.758, P < 0.000 1) respectively. Lymphocyte count could be considerad as a potential surrogate marker for CD(+)4T cell count in HIV/AIDS patients not having access to T cell subset test by flowcytometry.

Two-Way Gene Interaction From Microarray Data Based on Correlation Methods.

PubMed

Alavi Majd, Hamid; Talebi, Atefeh; Gilany, Kambiz; Khayyer, Nasibeh

2016-06-01

Gene networks have generated a massive explosion in the development of high-throughput techniques for monitoring various aspects of gene activity. Networks offer a natural way to model interactions between genes, and extracting gene network information from high-throughput genomic data is an important and difficult task. The purpose of this study is to construct a two-way gene network based on parametric and nonparametric correlation coefficients. The first step in constructing a Gene Co-expression Network is to score all pairs of gene vectors. The second step is to select a score threshold and connect all gene pairs whose scores exceed this value. In the foundation-application study, we constructed two-way gene networks using nonparametric methods, such as Spearman's rank correlation coefficient and Blomqvist's measure, and compared them with Pearson's correlation coefficient. We surveyed six genes of venous thrombosis disease, made a matrix entry representing the score for the corresponding gene pair, and obtained two-way interactions using Pearson's correlation, Spearman's rank correlation, and Blomqvist's coefficient. Finally, these methods were compared with Cytoscape, based on BIND, and Gene Ontology, based on molecular function visual methods; R software version 3.2 and Bioconductor were used to perform these methods. Based on the Pearson and Spearman correlations, the results were the same and were confirmed by Cytoscape and GO visual methods; however, Blomqvist's coefficient was not confirmed by visual methods. Some results of the correlation coefficients are not the same with visualization. The reason may be due to the small number of data.

A new computer-based Farnsworth Munsell 100-hue test for evaluation of color vision.

PubMed

Ghose, Supriyo; Parmar, Twinkle; Dada, Tanuj; Vanathi, Murugesan; Sharma, Sourabh

2014-08-01

To evaluate a computer-based Farnsworth-Munsell (FM) 100-hue test and compare it with a manual FM 100-hue test in normal and congenital color-deficient individuals. Fifty color defective subjects and 200 normal subjects with a best-corrected visual acuity ≥ 6/12 were compared using a standard manual FM 100-hue test and a computer-based FM 100-hue test under standard operating conditions as recommended by the manufacturer after initial trial testing. Parameters evaluated were total error scores (TES), type of defect and testing time. Pearson's correlation coefficient was used to determine the relationship between the test scores. Cohen's kappa was used to assess agreement of color defect classification between the two tests. A receiver operating characteristic curve was used to determine the optimal cut-off score for the computer-based FM 100-hue test. The mean time was 16 ± 1.5 (range 6-20) min for the manual FM 100-hue test and 7.4 ± 1.4 (range 5-13) min for the computer-based FM 100-hue test, thus reducing testing time to <50 % (p < 0.05). For grading color discrimination, Pearson's correlation coefficient for TES between the two tests was 0.91 (p < 0.001). For color defect classification, Cohen's agreement coefficient was 0.98 (p < 0.01). The computer-based FM 100-hue is an effective and rapid method for detecting, classifying and grading color vision anomalies.

Spiritual Well-Being and Its Relationship with Mindfulness, Self-Compassion and Satisfaction with Life in Baccalaureate Nursing Students: A Correlation Study.

PubMed

Mathad, Monali D; Rajesh, S K; Pradhan, Balaram

2017-12-06

The present study aimed to explore the correlates and predictors of spiritual well-being among nursing students. One hundred and forty-five BSc nursing students were recruited from three nursing colleges in Bangalore, Karnataka, India. Data were collected using SHALOM, FMI, SCS-SF and SWLS questionnaires and analysed by the Pearson correlation test and multiple regression analysis. The results of our study revealed a significant correlation between variables, and a considerable amount of variance was explained by self-compassion, mindfulness and satisfaction with life on personal, communal, environmental and transcendental domains of spiritual well-being.

Information and Communication Technology (ICT) Usage and Achievement of Turkish Students in Pisa 2006

ERIC Educational Resources Information Center

Aypay, Ahmet

2010-01-01

The purpose of this study is to examine the ICT usage and academic achievement of Turkish students in PISA 2006 data. The sample of the study included 4942 students from 160 schools. Frequencies, independent samples t-tests, ANOVAs, pearson correlation coefficients, exploratory factor analysis, and regression analysis were used. A high percentage…

Sequential accelerated tests: Improving the correlation of accelerated tests to module performance in the field

NASA Astrophysics Data System (ADS)

Felder, Thomas; Gambogi, William; Stika, Katherine; Yu, Bao-Ling; Bradley, Alex; Hu, Hongjie; Garreau-Iles, Lucie; Trout, T. John

2016-09-01

DuPont has been working steadily to develop accelerated backsheet tests that correlate with solar panels observations in the field. This report updates efforts in sequential testing. Single exposure tests are more commonly used and can be completed more quickly, and certain tests provide helpful predictions of certain backsheet failure modes. DuPont recommendations for single exposure tests are based on 25-year exposure levels for UV and humidity/temperature, and form a good basis for sequential test development. We recommend a sequential exposure of damp heat followed by UV then repetitions of thermal cycling and UVA. This sequence preserves 25-year exposure levels for humidity/temperature and UV, and correlates well with a large body of field observations. Measurements can be taken at intervals in the test, although the full test runs 10 months. A second, shorter sequential test based on damp heat and thermal cycling tests mechanical durability and correlates with loss of mechanical properties seen in the field. Ongoing work is directed toward shorter sequential tests that preserve good correlation to field data.

Correlation between clinical and cognitive aspects and nutritional indicators of elderly patients with new-onset epilepsy.

PubMed

Tedrus, Gloria Maria A S; Screbenich, Silvana Mariana; Santos, Tamires Barbosa Nascimento

2018-06-20

Nutritional indicators were correlated with cognitive and clinical aspects of 25 elderly patients with new-onset epilepsy (EPWE). The nutritional indicators of the EPWE were compared with those of a similar control group at a significance level of p < 0.05. There was lower cognitive performance, greater risk of malnutrition and muscle tissue depletion, and higher waist circumference (WC) in the EPWE. Longer epilepsy duration was correlated with loss of muscle mass (Pearson's correlation: 0.433; p = 0.044). Performance in the verbal fluency test, in the clock-drawing test, and in the immediate memory test was negatively associated with body fat. Better performance in the image recognition test was negatively associated with the indicators of muscle reserve. There was lower cognitive performance, higher risk of malnutrition, and high abdominal obesity in EPWE. Cognitive performance was related to adiposity. Cognitive impairment and longer disease duration are related to increased nutritional risk. Copyright © 2018. Published by Elsevier Inc.

Pearson marrow pancreas syndrome in patients suspected to have Diamond-Blackfan anemia.

PubMed

Gagne, Katelyn E; Ghazvinian, Roxanne; Yuan, Daniel; Zon, Rebecca L; Storm, Kelsie; Mazur-Popinska, Magdalena; Andolina, Laura; Bubala, Halina; Golebiowska, Sydonia; Higman, Meghan A; Kalwak, Krzysztof; Kurre, Peter; Matysiak, Michal; Niewiadomska, Edyta; Pels, Salley; Petruzzi, Mary Jane; Pobudejska-Pieniazek, Aneta; Szczepanski, Tomasz; Fleming, Mark D; Gazda, Hanna T; Agarwal, Suneet

2014-07-17

Pearson marrow pancreas syndrome (PS) is a multisystem disorder caused by mitochondrial DNA (mtDNA) deletions. Diamond-Blackfan anemia (DBA) is a congenital hypoproliferative anemia in which mutations in ribosomal protein genes and GATA1 have been implicated. Both syndromes share several features including early onset of severe anemia, variable nonhematologic manifestations, sporadic genetic occurrence, and occasional spontaneous hematologic improvement. Because of the overlapping features and relative rarity of PS, we hypothesized that some patients in whom the leading clinical diagnosis is DBA actually have PS. Here, we evaluated patient DNA samples submitted for DBA genetic studies and found that 8 (4.6%) of 173 genetically uncharacterized patients contained large mtDNA deletions. Only 2 (25%) of the patients had been diagnosed with PS on clinical grounds subsequent to sample submission. We conclude that PS can be overlooked, and that mtDNA deletion testing should be performed in the diagnostic evaluation of patients with congenital anemia. © 2014 by The American Society of Hematology.

The Correlation Between Metacognition Level with Self-Efficacy of Biology Education College Students

NASA Astrophysics Data System (ADS)

Ridlo, S.; Lutfiya, F.

2017-04-01

Self-efficacy is a strong predictor of academic achievement. Self-efficacy refers to the ability of college students to achieve the desired results. The metacognition level can influence college student’s self-efficacy. This study aims to identify college student’s metacognition level and self-efficacy, as well as determine the relationship between self-efficacy and metacognition level for college students of Biology Education 2013, Semarang State University. The ex-post facto quantitative research was conducted on 99 students Academic Year 2015/2016. Saturation sampling technique determined samples. E-D scale collected data for self-efficacy identification. Data for assess the metacognition level collected by Metacognitive Awareness Inventory. Data were analysed quantitatively by Pearson correlation and linear regression. Most college students have the high level of metacognition and average self-efficacy. Pearson correlation coefficient result was 0.367. This result showed that metacognition level and self-efficacy has a weak relationship. Based on linear regression test, self-efficacy influenced by metacognition level up to 13.5%. The results of the study showed that positive and significant relationships exist between metacognition level and self-efficacy. Therefore, if the metacognition level is high, then self-efficacy will also be high (appropriate).

Basal measures of insulin sensitivity and insulin secretion and simplified glucose tolerance tests in dogs.

PubMed

Verkest, K R; Fleeman, L M; Rand, J S; Morton, J M

2010-10-01

There is need for simple, inexpensive measures of glucose tolerance, insulin sensitivity, and insulin secretion in dogs. The aim of this study was to estimate the closeness of correlation between fasting and dynamic measures of insulin sensitivity and insulin secretion, the precision of fasting measures, and the agreement between results of standard and simplified glucose tolerance tests in dogs. A retrospective descriptive study using 6 naturally occurring obese and 6 lean dogs was conducted. Data from frequently sampled intravenous glucose tolerance tests (FSIGTTs) in 6 obese and 6 lean client-owned dogs were used to calculate HOMA, QUICKI, fasting glucose and insulin concentrations. Fasting measures of insulin sensitivity and secretion were compared with MINMOD analysis of FSIGTTs using Pearson correlation coefficients, and they were evaluated for precision by the discriminant ratio. Simplified sampling protocols were compared with standard FSIGTTs using Lin's concordance correlation coefficients, limits of agreement, and Pearson correlation coefficients. All fasting measures except fasting plasma glucose concentration were moderately correlated with MINMOD-estimated insulin sensitivity (|r| = 0.62-0.80; P < 0.03), and those that combined fasting insulin and glucose were moderately closely correlated with MINMOD-estimated insulin secretion (r = 0.60-0.79; P < 0.04). HOMA calculated using the nonlinear formulae had the closest estimated correlation (r = 0.77 and 0.74) and the best discrimination for insulin sensitivity and insulin secretion (discriminant ratio 4.4 and 3.4, respectively). Simplified sampling protocols with half as many samples collected over 3 h had close agreement with the full sampling protocol. Fasting measures and simplified intravenous glucose tolerance tests reflect insulin sensitivity and insulin secretion derived from frequently sampled glucose tolerance tests with MINMOD analysis in dogs. Copyright 2010 Elsevier Inc. All rights reserved.

Accidental deep field bias in CMB T and SNe z correlation

NASA Astrophysics Data System (ADS)

Friday, Tracey; Clowes, Roger G.; Raghunathan, Srinivasan; Williger, Gerard M.

2018-05-01

Evidence presented by Yershov, Orlov and Raikov apparently showed that the WMAP/Planck cosmic microwave background (CMB) pixel-temperatures (T) at supernovae (SNe) locations tend to increase with increasing redshift (z). They suggest this correlation could be caused by the Integrated Sachs-Wolfe effect and/or by some unrelated foreground emission. Here, we assess this correlation independently using Planck 2015 SMICA R2.01 data and, following Yershov et al., a sample of 2783 SNe from the Sternberg Astronomical Institute. Our analysis supports the prima facie existence of the correlation but attributes it to a composite selection bias (high CMB T × high SNe z) caused by the accidental alignment of seven deep survey fields with CMB hotspots. These seven fields contain 9.2 per cent of the SNe sample (256 SNe). Spearman's rank-order correlation coefficient indicates the correlation present in the whole sample (ρs = 0.5, p-value =6.7 × 10-9) is insignificant for a sub-sample of the seven fields together (ρs = 0.2, p-value =0.2) and entirely absent for the remainder of the SNe (ρs = 0.1, p-value =0.6). We demonstrate the temperature and redshift biases of these seven deep fields, and estimate the likelihood of their falling on CMB hotspots by chance is at least ˜ 6.8 per cent (approximately 1 in 15). We show that a sample of 7880 SNe from the Open Supernova Catalogue exhibits the same effect and we conclude that the correlation is an accidental but not unlikely selection bias.

Prevalence of Coxitis and its Correlation with Inflammatory Activity in Rheumatoid Arthritis.

PubMed

Bajraktari, Ismet H; Krasniqi, Blerim; Rexhepi, Sylejman; Bexheti, Sadi; Bahtiri, Elton; Bajraktari, Halit; Luri, Besim

2018-02-15

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterised by intra-articular and extra-articular manifestations but very rarely with coxitis. This study aimed to investigate the prevalence of coxitis, clinical changes, and its correlation with the parameters of inflammatory activity. A cohort of 951 patients diagnosed with ACR/EULAR (American College of Rheumatology/European League against Rheumatism) 2010 criteria was enrolled in this prospective, observational and analytic research study. The CBC (Complete Blood Count), ESR (Erythrocyte sedimentation rate), CRP(C - reactive protein), Anti CCP (Antibodies to cyclic citrullinated peptides), X-ray examination of palms and pelvis, and the activity of the disease as measured by DAS - 28 (28 - joint disease activity score) were carried out in all subjects. Independent samples t-test was used to compare the group's characteristics, whereas Pearson correlation test was used to analyse the correlation between study variables. Of the total number of the subjects, 730 (76.8 %) were females, whereas 221 (23.2%) were males. The average age was 51.3, y/o while the most of them were between 40 - 49 y/o (32.6%). The prevalence of coxitis was 14.2%, mostly found in males (19.46%). The echosonografic prevalence of changes was 21.45%, while the radiological changes were 16.3%; in both cases, the changes were more expressed in males. The analysis showed that inflammatory parameters were significantly higher in patients with coxitis. Coxitis has high economic cost because it ends up with a mandatory need for a total hip joint prosthesis. Thus the results of this study can serve to plan and initiate early preventive measures.

Prevalence of Coxitis and its Correlation with Inflammatory Activity in Rheumatoid Arthritis

PubMed Central

Bajraktari, Ismet H.; Krasniqi, Blerim; Rexhepi, Sylejman; Bexheti, Sadi; Bahtiri, Elton; Bajraktari, Halit; Luri, Besim

2018-01-01

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterised by intra-articular and extra-articular manifestations but very rarely with coxitis. AIM: This study aimed to investigate the prevalence of coxitis, clinical changes, and its correlation with the parameters of inflammatory activity. METHODS: A cohort of 951 patients diagnosed with ACR/EULAR (American College of Rheumatology/European League against Rheumatism) 2010 criteria was enrolled in this prospective, observational and analytic research study. The CBC (Complete Blood Count), ESR (Erythrocyte sedimentation rate), CRP(C - reactive protein), Anti CCP (Antibodies to cyclic citrullinated peptides), X-ray examination of palms and pelvis, and the activity of the disease as measured by DAS - 28 (28 - joint disease activity score) were carried out in all subjects. Independent samples t-test was used to compare the group’s characteristics, whereas Pearson correlation test was used to analyse the correlation between study variables. RESULTS: Of the total number of the subjects, 730 (76.8 %) were females, whereas 221 (23.2%) were males. The average age was 51.3, y/o while the most of them were between 40 - 49 y/o (32.6%). The prevalence of coxitis was 14.2%, mostly found in males (19.46%). The echosonografic prevalence of changes was 21.45%, while the radiological changes were 16.3%; in both cases, the changes were more expressed in males. The analysis showed that inflammatory parameters were significantly higher in patients with coxitis. CONCLUSION: Coxitis has high economic cost because it ends up with a mandatory need for a total hip joint prosthesis. Thus the results of this study can serve to plan and initiate early preventive measures. PMID:29531599

Improving Multidimensional Wireless Sensor Network Lifetime Using Pearson Correlation and Fractal Clustering.

PubMed

Almeida, Fernando R; Brayner, Angelo; Rodrigues, Joel J P C; Maia, Jose E Bessa

2017-06-07

An efficient strategy for reducing message transmission in a wireless sensor network (WSN) is to group sensors by means of an abstraction denoted cluster. The key idea behind the cluster formation process is to identify a set of sensors whose sensed values present some data correlation. Nowadays, sensors are able to simultaneously sense multiple different physical phenomena, yielding in this way multidimensional data. This paper presents three methods for clustering sensors in WSNs whose sensors collect multidimensional data. The proposed approaches implement the concept of multidimensional behavioral clustering . To show the benefits introduced by the proposed methods, a prototype has been implemented and experiments have been carried out on real data. The results prove that the proposed methods decrease the amount of data flowing in the network and present low root-mean-square error (RMSE).

Rapid down-regulation of γc on T cells in early SIV infection correlates with impairment of T-cell function

PubMed Central

Xu, Huanbin; Wang, Xiaolei; Pahar, Bapi; Alvarez, Xavier; Rasmussen, Kelsi K.; Lackner, Andrew A.; Veazey, Ronald S.

2012-01-01

The common γc subunit molecule is shared among all γc cytokines and clearly involved in T-cell function, but its role in HIV infection and immunity is not well understood. Here, we examined expression and function of γc on T cells during SIV infection in Rhesus macaques. Surface γc distribution was differentially expressed on CD4+ and CD8+ T cells, and CD4+ naive/memory cell populations in various lymphoid tissues of normal macaques. However, surface γc expression was rapidly and significantly down-regulated on T cells in acute infection with pathogenic SIV, compared to infection with a less virulent SHIV or controls and did not recover on CD8+ T cells in the chronic stage. Moreover, the peripheral and CD4+T cell loss was inversely correlated with γc+ CD8+ T cells in individual tissues. γc+ T cells were mainly functional as evidenced by higher cytokine secretion and proliferative capacity. Further in vitro experiments found that surface γc expression could be down-regulated following high level of IL-7 treatment by both internalization and shedding. Down-regulation of γc during early HIV/SIV infection may inhibit T-cell function, particularly of CD8+ T cells, and, may be linked with immune failure and loss of viral containment.—Xu, H., Wang, X., Pahar, B., Alvarez, X., Rasmussen, K. K., Lackner, A. A., Veazey, R. S. Rapid down-regulation of γc on T cells in early SIV infection correlates with impairment of T-cell function. PMID:22375017

Phytoecdysteroids and flavonoid glycosides among Chilean and commercial sources of Chenopodium quinoa: variation and correlation to physicochemical characteristics

PubMed Central

Graf, Brittany; Rojo, Leonel E.; Delatorre-Herrera, Jose; Poulev, Alexander; Calfio, Camila; Raskin, Ilya

2015-01-01

BACKGROUND Little is known about varietal differences in the content of bioactive phytoecdysteroids (PE) and flavonoid glycosides (FG) from quinoa (Chenopodium quinoa Willd.). The aim of this study was to determine the variation in PE and FG content among seventeen distinct quinoa sources and identify correlations to genotypic (highland vs. lowland) and physicochemical characteristics (seed color, 100-seed weight, protein content, oil content). RESULTS PE and FG concentrations exhibited over 4-fold differences across quinoa sources, ranging from 138 ± 11 μg/g to 570 ± 124 μg/g total PE content and 192 ± 24 μg/g to 804 ± 91 μg/g total FG content. Mean FG content was significantly higher in highland Chilean varieties (583.6 ± 148.9 μg/g) versus lowland varieties (228.2 ± 63.1 μg/g) grown under the same environmental conditions (P = 0.0046; t-test). Meanwhile, PE content was positively and significantly correlated with oil content across all quinoa sources (r = 0.707, P = 0.002; Pearson correlation). CONCLUSION FG content may be genotypically regulated in quinoa. PE content may be increased via enhancement of oil content. These findings may open new avenues for the improvement and development of quinoa as a functional food. PMID:25683633

How well do Radiologic Assessments of Truncal and Shoulder Balance Correlate With Cosmetic Assessment Indices in Lenke 1C Adolescent Idiopathic Scoliosis?

PubMed

Sharma, Shallu; Andersen, Thomas; Wu, Chunsen; Sun, Haolin; Wang, Yu; Hansen, Ebbe S; Bünger, Cody E

2016-10-01

A correlation study. The primary objective was to determine the correlation between radiologic and cosmetic indices of trunk and shoulder balance before and after scoliosis surgery in Lenke 1C adolescent idiopathic scoliosis and to determine whether postoperative trunk shift is affiliated with worsening of the patients' cosmesis. Achieving a symmetrical appearance with truncal and shoulder balance is of prime importance to adolescent idiopathic scoliosis patients and their surgeons. However, surgeons prefer radiographic indices rather than measures of patients' clinical appearance. If radiographic indices are to be considered accurate depictions of the patient's cosmesis, radiologic and cosmetic indices must necessarily exhibit high association. Radiographic and cosmetic indices of trunk and shoulder balance, along with posterior trunk symmetry index, were measured preoperatively and 3 months postoperatively in 33 Lenke 1C scoliosis patients. Pearson correlation analysis was performed. Paired t test was used to determine significant changes in radiographic and cosmetic indices after surgery. Independent-sample t test was used for all intergroup analyses in trunk shift and no-trunk-shift groups. Correlation coefficients between radiologic and cosmetic indices ranged between -0.63 and 0.70 with thoracic apical vertebra-central sacral vertical line (AV-CSVL) distance and first rib angle showing consistent correlations with cosmetic trunk and cosmetic shoulder balance indices. Trunk shift, a postoperative iatrogenic phenomenon, was seen in 19 (58%) patients. These patients had higher preoperative thoracic AV-CSVL translation, thoracic apical vertebra-first thoracic vertebra (AV-T1) translation, thoracic deformity correction rate, AV-T1 correction rates, and shorter fusions compared with the no-trunk-shift group. Posterior trunk symmetry index worsened in trunk shift group and improved significantly (-7.94 vs. 16.53) in no-trunk-shift group. Significant association (P=0

Correlation or Limits of Agreement? Applying the Bland-Altman Approach to the Comparison of Cognitive Screening Instruments.

PubMed

Larner, A J

2016-01-01

Calculation of correlation coefficients is often undertaken as a way of comparing different cognitive screening instruments (CSIs). However, test scores may correlate but not agree, and high correlation may mask lack of agreement between scores. The aim of this study was to use the methodology of Bland and Altman to calculate limits of agreement between the scores of selected CSIs and contrast the findings with Pearson's product moment correlation coefficients between the test scores of the same instruments. Datasets from three pragmatic diagnostic accuracy studies which examined the Mini-Mental State Examination (MMSE) vs. the Montreal Cognitive Assessment (MoCA), the MMSE vs. the Mini-Addenbrooke's Cognitive Examination (M-ACE), and the M-ACE vs. the MoCA were analysed to calculate correlation coefficients and limits of agreement between test scores. Although test scores were highly correlated (all >0.8), calculated limits of agreement were broad (all >10 points), and in one case, MMSE vs. M-ACE, was >15 points. Correlation is not agreement. Highly correlated test scores may conceal broad limits of agreement, consistent with the different emphases of different tests with respect to the cognitive domains examined. Routine incorporation of limits of agreement into diagnostic accuracy studies which compare different tests merits consideration, to enable clinicians to judge whether or not their agreement is close. © 2016 S. Karger AG, Basel.

Correlation of the plasma sphingoid base profile with results from oral glucose tolerance tests in gestational diabetes mellitus

PubMed Central

Khan, Abad; Hornemann, Thorsten

2017-01-01

Oral glucose tolerance test (OGTT) is usually insufficient to accurately predict the risk for type 2 diabetes mellitus (T2DM), it is therefore necessary to identify an additional biomarker that would most likely improve the accuracy of OGTT. The current OGTT was performed in 53 volunteers after ingestion of 75 g glucose in 250 ml water to each volunteer. Similarly the sphingoid base profile of these volunteers was explored using liquid-chromatography linked with mass spectrometer (LC-MS) and correlated with the different time-points glucose values of OGTT as well as with total area under the curve (tAUC), incremental area under the curve (iAUC), and positive incremental area under the curve (pAUC). The findings showed that 1-deoxysphinganine (1-deoxySA) was significantly positively correlated with the 1-hour, 2-hour, and 3-hour plasma glucose level as well as with total, incremental, and positive incremental AUC while 1-deoxysphingosine (1-deoxySO) was correlated only with 1-hour, 2-hour glucose levels and tAUC of OGTT. The C18SAdiene was negatively correlated with all-time points glucose values and AUCs followed by negative correlation of C18SO, C16SO and C17SO with 2-hour glucose and tAUC of OGTT. The ratios of 1-deoxySA and 1-deoxySO with respect to C18SAdiene have shown significant correlation with 2-hour and AUCs. These ratios were higher in subjects with gestational diabetes in comparison with normal subjects. These findings underlined that 1-deoxysphingolipids (1-deoxySLs) and their ratios with C18SAdiene could be significantly correlated with the glucose load of OGTT and might be used as predictive biomarkers along with OGTT for the risk assessment of diabetes. PMID:28694753

In arthritis the Doppler based degree of hypervascularisation shows a positive correlation with synovial leukocyte count and distinguishes joints with leukocytes greater and less than 5/nL.

PubMed

Löffler, Christian; Sattler, Horst; Peters, Lena; Tuleweit, Anika; Löffler, Uta; Wadsack, Daniel; Uppenkamp, Michael; Bergner, Raoul

2016-10-01

Power Doppler ultrasound is used to assess joint vascularity in acute arthritis. PDUS signals have been correlated with synovial histology and bone deterioration. Little is known about the correlation between power Doppler signals and synovial white blood count. In our study, we analyzed power Doppler signals in inflammatory joint diseases including gout, calcium pyrophosphate deposition disease, rheumatoid arthritis, spondyloarthritis and others and correlated power Doppler signals with synovial white blood count and with serologic markers of inflammation. We retrospectively evaluated 194 patients with arthritis. All patients underwent joint sonography, power Doppler ultrasound, synovial fluid analysis and blood examination of C-reactive protein and erythrocyte sedimentation rate. Correlation analyses (Spearman and Pearson), Chi(2) test, t-tests, a unifactorial ANOVA and regression analyses were applied. Hypervascularisation in power Doppler was most prominent in gout and calcium pyrophosphate deposition disease. Spondyloarthritis and non-inflammatory joint diseases presented with low degrees of hypervascularisation. Mean synovial white blood count did not differ significantly between crystal-related arthritides, rheumatoid arthritis, spondyloarthritis or other inflammatory joint diseases. There was a positive but weak correlation between power Doppler signals and synovial white blood count (P<0.001, rs=0.283), erythrocyte sedimentation rate (P<0.001, rs=0.387) and C-reactive protein (P<0.001, rs=0.373) over all diagnoses. This was especially relevant in rheumatoid arthritis (P<0.01, rs=0.479). Power Doppler degrees 0 and 1 were able to predict synovial leukocytes<5/nL, degrees 2 and 3 predict leukocytes≥5/nL (P<0.001). Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Prentice Hall/Pearson Literature© (2007-15). What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2017

2017-01-01

"Prentice Hall/Pearson Literature©" (2007-15) is an English language arts curriculum designed for students in grades 6-12 that focuses on building reading, vocabulary, literary analysis, and writing skills. It uses passages from fiction and nonfiction texts, poetry, and contemporary digital media. The curriculum is based on a textbook.…

Correlation and simple linear regression.

PubMed

Zou, Kelly H; Tuncali, Kemal; Silverman, Stuart G

2003-06-01

In this tutorial article, the concepts of correlation and regression are reviewed and demonstrated. The authors review and compare two correlation coefficients, the Pearson correlation coefficient and the Spearman rho, for measuring linear and nonlinear relationships between two continuous variables. In the case of measuring the linear relationship between a predictor and an outcome variable, simple linear regression analysis is conducted. These statistical concepts are illustrated by using a data set from published literature to assess a computed tomography-guided interventional technique. These statistical methods are important for exploring the relationships between variables and can be applied to many radiologic studies.

Celiac disease in siblings with Pearson syndrome.

PubMed

Köklü, Seyfettin; Alioğlu, Bülent; Akbal, Erdem; Koçak, Erdem

2010-04-01

Pearson syndrome (PS) is a rare mitochondrial disorder characterized by sideroblastic anemia and exocrine pancreas deficiency as a result of mitochondrial DNA deletion or deletion-duplication. A 21-year-old woman and 11-year-old brother who had been diagnosed as PS at the age of 18 and 8, respectively, were admitted to our hospital with the complaints of chronic diarrhea while using exogenous pancreas enzymes. Diarrhea was present in both for a long time and attributed to existing PS. Endoscopic and laboratory examinations revealed celiac disease (CD). After gluten-free diet, their symptoms were resolved. Detailed family investigation revealed that parents and the sister of the siblings were free of both PS and CD. To our knowledge, there has been no previous report of the presence of these 2 disorders, PS and CD, in the same patient. CD should be screened and treated appropriately in cases with PS.

Correlational structure of ‘frontal’ tests and intelligence tests indicates two components with asymmetrical neurostructural correlates in old age

PubMed Central

Cox, Simon R.; MacPherson, Sarah E.; Ferguson, Karen J.; Nissan, Jack; Royle, Natalie A.; MacLullich, Alasdair M.J.; Wardlaw, Joanna M.; Deary, Ian J.

2014-01-01

Both general fluid intelligence (gf) and performance on some ‘frontal tests’ of cognition decline with age. Both types of ability are at least partially dependent on the integrity of the frontal lobes, which also deteriorate with age. Overlap between these two methods of assessing complex cognition in older age remains unclear. Such overlap could be investigated using inter-test correlations alone, as in previous studies, but this would be enhanced by ascertaining whether frontal test performance and gf share neurobiological variance. To this end, we examined relationships between gf and 6 frontal tests (Tower, Self-Ordered Pointing, Simon, Moral Dilemmas, Reversal Learning and Faux Pas tests) in 90 healthy males, aged ~ 73 years. We interpreted their correlational structure using principal component analysis, and in relation to MRI-derived regional frontal lobe volumes (relative to maximal healthy brain size). gf correlated significantly and positively (.24 ≤ r ≤ .53) with the majority of frontal test scores. Some frontal test scores also exhibited shared variance after controlling for gf. Principal component analysis of test scores identified units of gf-common and gf-independent variance. The former was associated with variance in the left dorsolateral (DL) and anterior cingulate (AC) regions, and the latter with variance in the right DL and AC regions. Thus, we identify two biologically-meaningful components of variance in complex cognitive performance in older age and suggest that age-related changes to DL and AC have the greatest cognitive impact. PMID:25278641

Electric vehicle chassis dynamometer test methods at JPL and their correlation to track tests

NASA Technical Reports Server (NTRS)

Marte, J.; Bryant, J.

1983-01-01

Early in its electric vehicle (EV) test program, JPL recognized that EV test procedures were too vague and too loosely defined to permit much meaningful data to be obtained from the testing. Therefore, JPL adopted more stringent test procedures and chose the chassis dynamometer rather than the track as its principal test technique. Through the years, test procedures continued to evolve towards a methodology based on chassis dynamometers which would exhibit good correlation with track testing. Based on comparative dynamometer and track test results on the ETV-1 vehicle, the test methods discussed in this report demonstrate a means by which excellent track-to-dynamometer correlation can be obtained.

Kolmogorov-Smirnov test for spatially correlated data

USGS Publications Warehouse

Olea, R.A.; Pawlowsky-Glahn, V.

2009-01-01

The Kolmogorov-Smirnov test is a convenient method for investigating whether two underlying univariate probability distributions can be regarded as undistinguishable from each other or whether an underlying probability distribution differs from a hypothesized distribution. Application of the test requires that the sample be unbiased and the outcomes be independent and identically distributed, conditions that are violated in several degrees by spatially continuous attributes, such as topographical elevation. A generalized form of the bootstrap method is used here for the purpose of modeling the distribution of the statistic D of the Kolmogorov-Smirnov test. The innovation is in the resampling, which in the traditional formulation of bootstrap is done by drawing from the empirical sample with replacement presuming independence. The generalization consists of preparing resamplings with the same spatial correlation as the empirical sample. This is accomplished by reading the value of unconditional stochastic realizations at the sampling locations, realizations that are generated by simulated annealing. The new approach was tested by two empirical samples taken from an exhaustive sample closely following a lognormal distribution. One sample was a regular, unbiased sample while the other one was a clustered, preferential sample that had to be preprocessed. Our results show that the p-value for the spatially correlated case is always larger that the p-value of the statistic in the absence of spatial correlation, which is in agreement with the fact that the information content of an uncorrelated sample is larger than the one for a spatially correlated sample of the same size. ?? Springer-Verlag 2008.

Improving Multidimensional Wireless Sensor Network Lifetime Using Pearson Correlation and Fractal Clustering

PubMed Central

Almeida, Fernando R.; Brayner, Angelo; Rodrigues, Joel J. P. C.; Maia, Jose E. Bessa

2017-01-01

An efficient strategy for reducing message transmission in a wireless sensor network (WSN) is to group sensors by means of an abstraction denoted cluster. The key idea behind the cluster formation process is to identify a set of sensors whose sensed values present some data correlation. Nowadays, sensors are able to simultaneously sense multiple different physical phenomena, yielding in this way multidimensional data. This paper presents three methods for clustering sensors in WSNs whose sensors collect multidimensional data. The proposed approaches implement the concept of multidimensional behavioral clustering. To show the benefits introduced by the proposed methods, a prototype has been implemented and experiments have been carried out on real data. The results prove that the proposed methods decrease the amount of data flowing in the network and present low root-mean-square error (RMSE). PMID:28590450

The influence of base rates on correlations: An evaluation of proposed alternative effect sizes with real-world data.

PubMed

Babchishin, Kelly M; Helmus, Leslie-Maaike

2016-09-01

Correlations are the simplest and most commonly understood effect size statistic in psychology. The purpose of the current paper was to use a large sample of real-world data (109 correlations with 60,415 participants) to illustrate the base rate dependence of correlations when applied to dichotomous or ordinal data. Specifically, we examined the influence of the base rate on different effect size metrics. Correlations decreased when the dichotomous variable did not have a 50 % base rate. The higher the deviation from a 50 % base rate, the smaller the observed Pearson's point-biserial and Kendall's tau correlation coefficients. In contrast, the relationship between base rate deviations and the more commonly proposed alternatives (i.e., polychoric correlation coefficients, AUCs, Pearson/Thorndike adjusted correlations, and Cohen's d) were less remarkable, with AUCs being most robust to attenuation due to base rates. In other words, the base rate makes a marked difference in the magnitude of the correlation. As such, when using dichotomous data, the correlation may be more sensitive to base rates than is optimal for the researcher's goals. Given the magnitude of the association between the base rate and point-biserial correlations (r = -.81) and Kendall's tau (r = -.80), we recommend that AUCs, Pearson/Thorndike adjusted correlations, Cohen's d, or polychoric correlations should be considered as alternate effect size statistics in many contexts.

The relationship between vertical jump power estimates and weightlifting ability: a field-test approach.

PubMed

Carlock, Jon M; Smith, Sarah L; Hartman, Michael J; Morris, Robert T; Ciroslan, Dragomir A; Pierce, Kyle C; Newton, Robert U; Harman, Everett A; Sands, William A; Stone, Michael H

2004-08-01

The purpose of this study was to assess the usefulness of the vertical jump and estimated vertical-jump power as a field test for weightlifting. Estimated PP output from the vertical jump was correlated with lifting ability among 64 USA national-level weightlifters (junior and senior men and women). Vertical jump was measured using the Kinematic Measurement System, consisting of a switch mat interfaced with a laptop computer. Vertical jumps were measured using a hands-on-hips method. A counter-movement vertical jump (CMJ) and a static vertical jump (SJ, 90 degrees knee angle) were measured. Two trials were given for each condition. Test-retest reliability for jump height was intra-class correlation (ICC) = 0.98 (CMJ) and ICC = 0.96 (SJ). Athletes warmed up on their own for 2-3 minutes, followed by 2 practice jumps at each condition. Peak power (PP) was estimated using the equations developed by Sayers et al. (24). The athletes' current lifting capabilities were assessed by a questionnaire, and USA national coaches checked the listed values. Differences between groups (i.e., men versus women, juniors versus resident lifters) were determined using t-tests (p < or = 0.05). Correlations were determined using Pearson's r. Results indicate that vertical jumping PP is strongly associated with weightlifting ability. Thus, these results indicate that PP derived from the vertical jump (CMJ or SJ) can be a valuable tool in assessing weightlifting performance.

Pelvic floor muscle strength of women consulting at the gynecology outpatient clinics and its correlation with sexual dysfunction: A cross-sectional study.

PubMed

Ozdemir, Filiz Ciledag; Pehlivan, Erkan; Melekoglu, Rauf

2017-01-01

To investigate the pelvic floor muscle strength of the women andevaluateits possible correlation with sexual dysfunction. In this cross-sectional type study, stratified clusters were used for the sampling method. Index of Female Sexual Function (IFSF) worksheetwere used for questions on sexual function. The pelvic floor muscle strength of subjects was assessed byperineometer. The chi-squared test, logistic regression and Pearson's correlation analysis were used for the statistical analysis. Four hundred thirty primiparous women, mean age 38.5 participated in this study. The average pelvic floor muscle strength value was found 31.4±9.6 cm H 2 O and the average Index of Female Sexual Function (IFSF) score was found 26.5±6.9. Parity (odds ratio OR=5.546) and age 40 or higher (OR=3.484) were found correlated with pelvic floor muscle weakness (p<0.05). The factors directly correlated with sexual dysfunction were found being overweight (OR=2.105) and age 40 or higher (OR=2.451) (p<0.05). Pearson's correlation analysis showed that there was a statistically significantlinear correlation between the muscular strength of the pelvic floor and sexual function (p=0.001). The results suggested subjects with decreased pelvic floor muscle strength value had higher frequency of sexual dysfunction.

Correlated displacement-T2 MRI by means of a Pulsed Field Gradient-Multi Spin Echo Method.

PubMed

Windt, Carel W; Vergeldt, Frank J; Van As, Henk

2007-04-01

A method for correlated displacement-T2 imaging is presented. A Pulsed Field Gradient-Multi Spin Echo (PFG-MSE) sequence is used to record T2 resolved propagators on a voxel-by-voxel basis, making it possible to perform single voxel correlated displacement-T2 analyses. In spatially heterogeneous media the method thus gives access to sub-voxel information about displacement and T2 relaxation. The sequence is demonstrated using a number of flow conducting model systems: a tube with flowing water of variable intrinsic T2's, mixing fluids of different T2's in an "X"-shaped connector, and an intact living plant. PFG-MSE can be applied to yield information about the relation between flow, pore size and exchange behavior, and can aid volume flow quantification by making it possible to correct for T2 relaxation during the displacement labeling period Delta in PFG displacement imaging methods. Correlated displacement-T2 imaging can be of special interest for a number of research subjects, such as the flow of liquids and mixtures of liquids or liquids and solids moving through microscopic conduits of different sizes (e.g., plants, porous media, bioreactors, biomats).

Uterine Fibroids: Correlation of T2 Signal Intensity with Semiquantitative Perfusion MR Parameters in Patients Screened for MR-guided High-Intensity Focused Ultrasound Ablation.

PubMed

Kim, Young-Sun; Lee, Jeong-Won; Choi, Chel Hun; Kim, Byoung-Gie; Bae, Duk-Soo; Rhim, Hyunchul; Lim, Hyo Keun

2016-03-01

To evaluate the relationships between T2 signal intensity and semiquantitative perfusion magnetic resonance (MR) parameters of uterine fibroids in patients who were screened for MR-guided high-intensity focused ultrasound (HIFU) ablation. Institutional review board approval was granted, and informed consents were waived. One hundred seventy most symptom-relevant, nondegenerated uterine fibroids (mean diameter, 7.3 cm; range, 3.0-17.2 cm) in 170 women (mean age, 43.5 years; range, 24-56 years) undergoing screening MR examinations for MR-guided HIFU ablation from October 2009 to April 2014 were retrospectively analyzed. Fibroid signal intensity was assessed as the ratio of the fibroid T2 signal intensity to that of skeletal muscle. Parameters of semiquantitative perfusion MR imaging obtained during screening MR examination (peak enhancement, percentage of relative peak enhancement, time to peak [in seconds], wash-in rate [per seconds], and washout rate [per seconds]) were investigated to assess their relationships with T2 signal ratio by using multiple linear regression analysis. Correlations between T2 signal intensity and independently significant perfusion parameters were then evaluated according to fibroid type by using Spearman correlation test. Multiple linear regression analysis revealed that relative peak enhancement showed an independently significant correlation with T2 signal ratio (Β = 0.004, P < .001). Submucosal intracavitary (n = 20, ρ = 0.275, P = .240) and type III (n = 18, ρ = 0.082, P = .748) fibroids failed to show significant correlations between perfusion and T2 signal intensity, while significant correlations were found for all other fibroid types (ρ = 0.411-0.629, P < .05). In possible candidates for MR-guided HIFU ablation, the T2 signal intensity of nondegenerated uterine fibroids showed an independently significant positive correlation with relative peak enhancement in most cases, except those of submucosal intracavitary or type III

Slow or swift, your patients' experience won't drift: absence of correlation between physician productivity and the patient experience.

PubMed

Lenz, Kasia; McRae, Andrew; Wang, Dongmei; Higgins, Benjamin; Innes, Grant; Cook, Timothy; Lang, Eddy

2017-09-01

Absract OBJECTIVES: To evaluate the relationship between Emergency Physician (EP) productivity and patient satisfaction with Emergency Department (ED) care. This retrospective observational study linked administrative and patient experience databases to measure correlations between the patient experience and EP productivity. The study was performed across three Calgary EDs (from June 2010 to July 2013). Patients>16 years old with completed Health Quality Council of Alberta (HQCA) ED Patient Experience Surveys were included. EP productivity was measured at the individual physician level and defined as the average number of patients seen per hour. The association between physician productivity and patient experience scores from six composite domains of the HQCA ED Patient Experience Survey were examined using Pearson correlation coefficients, linear regression modelling, and a path analysis. We correlated 3,794 patient experience surveys with productivity data for 130 EPs. Very weak non-significant negative correlations existed between productivity and survey composites: "Staff Care and Communication" (r=-0.057, p=0.521), "Discharge Communication" (r=-0.144, p=0.102), and "Respect" (r=-0.027, p=0.760). Very weak, non-significant positive correlations existed between productivity and the composite domains: "Medication Communication" (r=0.003, p=0.974) and "Pain management" (r=0.020, p=0.824). A univariate general linear model yielded no statistically significant correlations between EP productivity and patient experience, and the path analysis failed to show a relationship between the variables. We found no correlation between EP productivity and the patient experience.

Evaluation of "e-rater"® for the "Praxis I"®Writing Test. Research Report. ETS RR-15-03

ERIC Educational Resources Information Center

Ramineni, Chaitanya; Trapani, Catherine S.; Williamson, David M.

2015-01-01

Automated scoring models were trained and evaluated for the essay task in the "Praxis I"® writing test. Prompt-specific and generic "e-rater"® scoring models were built, and evaluation statistics, such as quadratic weighted kappa, Pearson correlation, and standardized differences in mean scores, were examined to evaluate the…

Correlation between increasing tissue ischemia and circulating levels of angiogenic growth factors in peripheral artery disease.

PubMed

Jalkanen, Juho; Hautero, Olli; Maksimow, Mikael; Jalkanen, Sirpa; Hakovirta, Harri

2018-04-21

The aim of the present study was to assess the circulating levels of vascular endothelial growth factor (VEGF) and other suggested therapeutic growth factors with the degree of ischemia in patients with different clinical manifestations of peripheral arterial disease (PAD) according to the Rutherford grades. The study cohort consists of 226 consecutive patients admitted to a Department of Vascular Surgery for elective invasive procedures. PAD patients were grouped according to the Rutherford grades after a clinical assessment. Ankle-brachial pressure indices (ABI) and absolute toe pressure (TP) values were measured. Serum levels of circulating VEGF, hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) were measured from serum and analysed against Rutherford grades and peripheral hemodynamic measurements. The levels of VEGF (P = 0.009) and HGF (P < 0.001) increased significantly as the ischaemic burden became more severe according to the Rutherford grades. PDGF behaved in opposite manner and declined along increasing Rutherford grades (P = 0.004). A significant, inverse correlations between Rutherford grades was detected as follows; VEGF (Pearson's correlation = 0.183, P = 0.004), HGF (Pearson's correlation = 0.253, P < 0.001), bFGF (Pearson's correlation = 0.169, P = 0.008) and PDGF (Pearson's correlation = 0.296, P < 0.001). In addition, VEGF had a clear direct negative correlation with ABI (Pearson's correlation -0.19, P = 0.009) and TP (Pearson's correlation -0.20, P = 0.005) measurements. Our present observations show that the circulating levels of VEGF and other suggested therapeutic growth factors are significantly increased along with increasing ischemia. These findings present a new perspective to anticipated positive effects of gene therapies utilizing VEGF, HGF, and bFGF, because the levels of these growth factors are endogenously high in end

T-cell antigenic sites involved in myasthenia gravis: correlations with antibody titre and disease severity.

PubMed

Berrih-Aknin, S; Cohen-Kaminsky, S; Lepage, V; Neumann, D; Bach, J F; Fuchs, S

1991-02-01

We have evaluated the ability of eight synthetic peptides corresponding to selected regions of the alpha-subunit from human (H) or Torpedo (T) acetylcholine receptor (AChR) to stimulate proliferative responses of peripheral blood lymphocytes (PBL) and thymic cells from patients with Myasthenia Gravis (MG) in comparison to healthy controls. Using PBL, two of the peptides were most reactive: in the 40 myasthenic patients tested, peptide 169-181 (H) induced significant proliferative responses in 10 patients and peptide 351-368 (H) in five, while there was no response in any of the 34 healthy controls tested. Interestingly, clear associations between proliferation to peptides and clinical data were observed. Indeed, among responding patients, all presented thymic hyperplasia and most showed a high anti-AChR Ab titre and/or a severe form of the disease. In addition, responses to AChR cytoplasmic sequences were observed only in severely affected patients. Correlation with HLA-DR haplotype, sought in a subgroup of patients, indicated that response to 169-181 (H) is associated with HLA-DR5 in the patients presenting a high anti-AChR antibody titre. Using thymic lymphocytes, few responses were obtained with the human peptides, suggesting that the frequency of autoreactive cells is lower than in the blood. Similar to PBL, responses to peptides were observed only with lymphocytes isolated from hyperplastic thymuses. The correlations observed between responses to peptides and clinical parameters underline the pathophysiological relevance of our data and indicate that pathogenic and nonpathogenic T-cell antigenic sites involved in the anti-AChR response could be identified by this approach.

Ocular blood flow values measured by laser speckle flowgraphy correlate with the postmenstrual age of normal neonates.

PubMed

Matsumoto, Tadashi; Itokawa, Takashi; Shiba, Tomoaki; Katayama, Yuuji; Arimura, Tetsushi; Hine, Kotaro; Mizukaki, Norio; Yoda, Hitoshi; Hori, Yuichi

2016-08-01

To evaluate the relationships between optic nerve head (ONH) blood flow by laser speckle flowgraphy (LSFG), and postmenstrual age and body weight in normal neonates. During their normal sleep, we studied 24 infants (postmenstrual age, 248-295 days) whose ocular blood flow could be measured three consecutive times. While the subjects slept in the supine position, three mean blur rate (MBR) values of the ONH were obtained: the MBR-A (mean of all values), MBR-V (vessel mean) and MBR-T (tissue mean) in the ONH. With regard to eye diseases, no retinopathy of prematurity (ROP) was observed, and no severe systemic diseases requiring treatment were noted in the subjects. Pearson's correlation coefficients were used to determine the relationship between the MBR-A, -V, -T and postmenstrual age (days) and body weight (g). Postmenstrual age was significantly correlated with MBR-A (r = 0.64, p = 0.0007), MBR-V (r = 0.62, p = 0.0012) and MBR-T (r = 0.62, p = 0.0012). However, the body weight was not correlated with the MBR (MBR-A: r = 0.37, p = 0.07, MBR-V: r = 0.31, p = 0.14, MBR-T: r = 0.38, p = 0.06). Our results clarified that the values of ocular blood flow measured by LSFG correlate with the postmenstrual age of normal neonates.

Bayesian Correlation Analysis for Sequence Count Data

PubMed Central

Lau, Nelson; Perkins, Theodore J.

2016-01-01

Evaluating the similarity of different measured variables is a fundamental task of statistics, and a key part of many bioinformatics algorithms. Here we propose a Bayesian scheme for estimating the correlation between different entities’ measurements based on high-throughput sequencing data. These entities could be different genes or miRNAs whose expression is measured by RNA-seq, different transcription factors or histone marks whose expression is measured by ChIP-seq, or even combinations of different types of entities. Our Bayesian formulation accounts for both measured signal levels and uncertainty in those levels, due to varying sequencing depth in different experiments and to varying absolute levels of individual entities, both of which affect the precision of the measurements. In comparison with a traditional Pearson correlation analysis, we show that our Bayesian correlation analysis retains high correlations when measurement confidence is high, but suppresses correlations when measurement confidence is low—especially for entities with low signal levels. In addition, we consider the influence of priors on the Bayesian correlation estimate. Perhaps surprisingly, we show that naive, uniform priors on entities’ signal levels can lead to highly biased correlation estimates, particularly when different experiments have widely varying sequencing depths. However, we propose two alternative priors that provably mitigate this problem. We also prove that, like traditional Pearson correlation, our Bayesian correlation calculation constitutes a kernel in the machine learning sense, and thus can be used as a similarity measure in any kernel-based machine learning algorithm. We demonstrate our approach on two RNA-seq datasets and one miRNA-seq dataset. PMID:27701449

Estimation of T2* Relaxation Time of Breast Cancer: Correlation with Clinical, Imaging and Pathological Features

PubMed Central

Seo, Mirinae; Jahng, Geon-Ho; Sohn, Yu-Mee; Rhee, Sun Jung; Oh, Jang-Hoon; Won, Kyu-Yeoun

2017-01-01

Objective The purpose of this study was to estimate the T2* relaxation time in breast cancer, and to evaluate the association between the T2* value with clinical-imaging-pathological features of breast cancer. Materials and Methods Between January 2011 and July 2013, 107 consecutive women with 107 breast cancers underwent multi-echo T2*-weighted imaging on a 3T clinical magnetic resonance imaging system. The Student's t test and one-way analysis of variance were used to compare the T2* values of cancer for different groups, based on the clinical-imaging-pathological features. In addition, multiple linear regression analysis was performed to find independent predictive factors associated with the T2* values. Results Of the 107 breast cancers, 92 were invasive and 15 were ductal carcinoma in situ (DCIS). The mean T2* value of invasive cancers was significantly longer than that of DCIS (p = 0.029). Signal intensity on T2-weighted imaging (T2WI) and histologic grade of invasive breast cancers showed significant correlation with T2* relaxation time in univariate and multivariate analysis. Breast cancer groups with higher signal intensity on T2WI showed longer T2* relaxation time (p = 0.005). Cancer groups with higher histologic grade showed longer T2* relaxation time (p = 0.017). Conclusion The T2* value is significantly longer in invasive cancer than in DCIS. In invasive cancers, T2* relaxation time is significantly longer in higher histologic grades and high signal intensity on T2WI. Based on these preliminary data, quantitative T2* mapping has the potential to be useful in the characterization of breast cancer. PMID:28096732

Extremely correlated Fermi liquid theory of the t-J model in 2 dimensions: low energy properties

NASA Astrophysics Data System (ADS)

Shastry, B. Sriram; Mai, Peizhi

2018-01-01

Low energy properties of the metallic state of the two-dimensional t-J model are presented for second neighbor hopping with hole-doping (t\\prime ≤slant 0) and electron-doping (t\\prime > 0), with various superexchange energy J. We use a closed set of equations for the Greens functions obtained from the extremely correlated Fermi liquid theory. These equations reproduce the known low energies features of the large U Hubbard model in infinite dimensions. The density and temperature dependent quasiparticle weight, decay rate and the peak spectral heights over the Brillouin zone are calculated. We also calculate the resistivity, Hall conductivity, Hall number and cotangent Hall angle. The spectral features display high thermal sensitivity at modest T for density n≳ 0.8, implying a suppression of the effective Fermi-liquid temperature by two orders of magnitude relative to the bare bandwidth. The cotangent Hall angle exhibits a T 2 behavior at low T, followed by an interesting kink at higher T. The Hall number exhibits strong renormalization due to correlations. Flipping the sign of t\\prime changes the curvature of the resistivity versus T curves between convex and concave. Our results provide a natural route for understanding the observed difference in the temperature dependent resistivity of strongly correlated electron-doped and hole-doped matter.

Epidemiological investigation of the UGT2B17 polymorphism in doping control urine samples and its correlation to T/E ratios.

PubMed

Anielski, Patricia; Simmchen, Juliane; Wassill, Lars; Ganghofner, Dirk; Thieme, Detlef

2011-10-01

The deletion polymorphism of the enzyme UGT2B17 is known to correlate with the level of the testosterone to epitestosterone (T/E) ratio in urine specimen. Due to the importance of the T/E ratio to detect testosterone abuse in doping analysis, a PCR-ELISA system (Genotype® UGT test, AmplexDiagnostics) was established to identify the UGT2B17 phenotype in urine samples. Epidemiological investigations in a set of 674 routine doping controls (in- and out-of-competition) resulted in 22.8% homozygote gene-deleted and 74.5% UGT2B17-positive athletes. The validated test system has shown to be robust and sensitive: in only 18 cases (2.7%) isolation of cell material from urine failed. Following hydrolysis of glucuronidated conjugates, steroids were analyzed as bis-TMS derivatives by gas chromatography-mass spectrometry (GC-MS), for example, testosterone (T) and epitestosterone (E). Additionally, isotope ration mass spectrometry (IRMS) analysis and luteinizing hormone (LH) measurement were applied. Mean T/E ratios significantly correlated with the UGT2B17 phenotype (del: T/E 0.9; pos: 1.7), however the values did not differ as distinctive as reported in previous studies. Additionally, the T/E ratios in the gene-deleted group did not show a normal curve of distribution (median of T/E 0.5). Obviously, beside the UGT2B17 deletion further influences have to be taken into account, for example, polymorphisms or induction of other metabolizing enzymes. Our results indicate that the UGT2B17 polymorphism might be insufficient when utilized solely as a crucial parameter for individual interpretation of T/E in urine. Nevertheless, the detection of the UGT2B17-gene deletion in urine samples would provide additional information important for gathering evidence in analysis of steroids in doping control. Copyright © 2011 John Wiley & Sons, Ltd.

Performance evaluation for epileptic electroencephalogram (EEG) detection by using Neyman-Pearson criteria and a support vector machine

NASA Astrophysics Data System (ADS)

Wang, Chun-mei; Zhang, Chong-ming; Zou, Jun-zhong; Zhang, Jian

2012-02-01

The diagnosis of several neurological disorders is based on the detection of typical pathological patterns in electroencephalograms (EEGs). This is a time-consuming task requiring significant training and experience. A lot of effort has been devoted to developing automatic detection techniques which might help not only in accelerating this process but also in avoiding the disagreement among readers of the same record. In this work, Neyman-Pearson criteria and a support vector machine (SVM) are applied for detecting an epileptic EEG. Decision making is performed in two stages: feature extraction by computing the wavelet coefficients and the approximate entropy (ApEn) and detection by using Neyman-Pearson criteria and an SVM. Then the detection performance of the proposed method is evaluated. Simulation results demonstrate that the wavelet coefficients and the ApEn are features that represent the EEG signals well. By comparison with Neyman-Pearson criteria, an SVM applied on these features achieved higher detection accuracies.

Multivariate Longitudinal Analysis with Bivariate Correlation Test

PubMed Central

Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

2016-01-01

In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model’s parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated. PMID:27537692

Multivariate Longitudinal Analysis with Bivariate Correlation Test.

PubMed

Adjakossa, Eric Houngla; Sadissou, Ibrahim; Hounkonnou, Mahouton Norbert; Nuel, Gregory

2016-01-01

In the context of multivariate multilevel data analysis, this paper focuses on the multivariate linear mixed-effects model, including all the correlations between the random effects when the dimensional residual terms are assumed uncorrelated. Using the EM algorithm, we suggest more general expressions of the model's parameters estimators. These estimators can be used in the framework of the multivariate longitudinal data analysis as well as in the more general context of the analysis of multivariate multilevel data. By using a likelihood ratio test, we test the significance of the correlations between the random effects of two dependent variables of the model, in order to investigate whether or not it is useful to model these dependent variables jointly. Simulation studies are done to assess both the parameter recovery performance of the EM estimators and the power of the test. Using two empirical data sets which are of longitudinal multivariate type and multivariate multilevel type, respectively, the usefulness of the test is illustrated.

Spatial computation of intratumoral T cells correlates with survival of patients with pancreatic cancer.

PubMed

Carstens, Julienne L; Correa de Sampaio, Pedro; Yang, Dalu; Barua, Souptik; Wang, Huamin; Rao, Arvind; Allison, James P; LeBleu, Valerie S; Kalluri, Raghu

2017-04-27

The exact nature and dynamics of pancreatic ductal adenocarcinoma (PDAC) immune composition remains largely unknown. Desmoplasia is suggested to polarize PDAC immunity. Therefore, a comprehensive evaluation of the composition and distribution of desmoplastic elements and T-cell infiltration is necessary to delineate their roles. Here we develop a novel computational imaging technology for the simultaneous evaluation of eight distinct markers, allowing for spatial analysis of distinct populations within the same section. We report a heterogeneous population of infiltrating T lymphocytes. Spatial distribution of cytotoxic T cells in proximity to cancer cells correlates with increased overall patient survival. Collagen-I and αSMA + fibroblasts do not correlate with paucity in T-cell accumulation, suggesting that PDAC desmoplasia may not be a simple physical barrier. Further exploration of this technology may improve our understanding of how specific stromal composition could impact T-cell activity, with potential impact on the optimization of immune-modulatory therapies.

Magnetic Resonance T2-Relaxometry and 2D L-Correlated Spectroscopy in Patients with Minimal Hepatic Encephalopathy

PubMed Central

Singhal, Aparna; Nagarajan, Rajakumar; Kumar, Rajesh; Huda, Amir; Gupta, Rakesh K.; Thomas, M. Albert

2010-01-01

Purpose To evaluate T2-relaxation changes in patients with minimal hepatic encephalopathy (MHE) using T2-relaxometry and to correlate T2 values with brain metabolites evaluated using two-dimensional (2D) magnetic resonance spectroscopy (MRS). Materials and Methods Eight MHE patients and 13 healthy subjects were evaluated using T2-relaxometry, and 8 patients and 9 healthy subjects underwent 2D MRS in right frontal and left occipital regions. Whole brain T2-relaxation maps were compared between MHE and control subjects using analysis-of-covariance, with age and gender included as covariates. T2 values derived from the right frontal and left occipital lobes were correlated with the metabolite ratios. Results Multiple brain regions including anterior and mid cingulate cortices, right anterior and left posterior insular cortices, right prefrontal, medial frontal, and right superior temporal cortices showed significantly increased T2 values in MHE patients compared to control subjects. MRS showed significantly increased ratios of glutamine/glutamate (Glx) and decreased ratios of myo-inositol, taurine, choline, and myo-inositol/choline (mICh) with respect to creatine (Cr_d) in patients compared to controls. Frontal Glx/Cr_d showed significantly positive correlation with T2 values. Conclusion MHE patients showed significantly increased T2 values in multiple brain regions reflecting increased free water content and T2 values in frontal lobe correlated with the increased Glx/Cr_d ratio. PMID:19856435

Correlation of visual in vitro cytotoxicity ratings of biomaterials with quantitative in vitro cell viability measurements.

PubMed

Bhatia, Sujata K; Yetter, Ann B

2008-08-01

Medical devices and implanted biomaterials are often assessed for biological reactivity using visual scores of cell-material interactions. In such testing, biomaterials are assigned cytotoxicity ratings based on visual evidence of morphological cellular changes, including cell lysis, rounding, spreading, and proliferation. For example, ISO 10993 cytotoxicity testing of medical devices allows the use of a visual grading scale. The present study compared visual in vitro cytotoxicity ratings to quantitative in vitro cytotoxicity measurements for biomaterials to determine the level of correlation between visual scoring and a quantitative cell viability assay. Biomaterials representing a spectrum of biological reactivity levels were evaluated, including organo-tin polyvinylchloride (PVC; a known cytotoxic material), ultra-high molecular weight polyethylene (a known non-cytotoxic material), and implantable tissue adhesives. Each material was incubated in direct contact with mouse 3T3 fibroblast cell cultures for 24 h. Visual scores were assigned to the materials using a 5-point rating scale; the scorer was blinded to the material identities. Quantitative measurements of cell viability were performed using a 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay; again, the assay operator was blinded to material identities. The investigation revealed a high degree of correlation between visual cytotoxicity ratings and quantitative cell viability measurements; a Pearson's correlation gave a correlation coefficient of 0.90 between the visual cytotoxicity score and the percent viable cells. An equation relating the visual cytotoxicity score and the percent viable cells was derived. The results of this study are significant for the design and interpretation of in vitro cytotoxicity studies of novel biomaterials.

The t-test: An Influential Inferential Tool in Chaplaincy and Other Healthcare Research.

PubMed

Jankowski, Katherine R B; Flannelly, Kevin J; Flannelly, Laura T

2018-01-01

The t-test developed by William S. Gosset (also known as Student's t-test and the two-sample t-test) is commonly used to compare one sample mean on a measure with another sample mean on the same measure. The outcome of the t-test is used to draw inferences about how different the samples are from each other. It is probably one of the most frequently relied upon statistics in inferential research. It is easy to use: a researcher can calculate the statistic with three simple tools: paper, pen, and a calculator. A computer program can quickly calculate the t-test for large samples. The ease of use can result in the misuse of the t-test. This article discusses the development of the original t-test, basic principles of the t-test, two additional types of t-tests (the one-sample t-test and the paired t-test), and recommendations about what to consider when using the t-test to draw inferences in research.

Weighted network analysis of high-frequency cross-correlation measures

NASA Astrophysics Data System (ADS)

Iori, Giulia; Precup, Ovidiu V.

2007-03-01

In this paper we implement a Fourier method to estimate high-frequency correlation matrices from small data sets. The Fourier estimates are shown to be considerably less noisy than the standard Pearson correlation measures and thus capable of detecting subtle changes in correlation matrices with just a month of data. The evolution of correlation at different time scales is analyzed from the full correlation matrix and its minimum spanning tree representation. The analysis is performed by implementing measures from the theory of random weighted networks.

Attributions, future time perspective and career maturity in nursing undergraduates: correlational study design.

PubMed

Cheng, Cheng; Yang, Liu; Chen, Yuxia; Zou, Huijing; Su, Yonggang; Fan, Xiuzhen

2016-01-25

Career maturity is an important parameter as nursing undergraduates prepare for their future careers. However, little is known regarding the relationships between attributions, future time perspective and career maturity among nursing undergraduates. The purpose of this study was to investigate the degree of career maturity and its relationship with attributions and future time perspective. A cross-sectional survey was designed. This survey was administered to 431 Chinese nursing undergraduates. Independent-sample t-tests and one-way ANOVA were performed to examine the mean differences between categories of binary and categorical demographic characteristics, respectively. Pearson correlations and multiple linear regressions were used to test the relationships between attributions, future time perspective and career maturity. The degree of career maturity was moderate among nursing undergraduates and that internal attributions of academic achievement, future efficacy and future purpose consciousness were positively associated with career maturity (all p < 0.01). These three factors accounted for 37.6% of the variance in career maturity (adjusted R(2) = 0.376). These findings might assist nursing educators and career counselors to improve nursing undergraduate career maturity by elucidating the imperative roles of internal attributions and future time perspective and to facilitate their transition from school to clinical practice.

Neurocognitive correlates of white matter in children surviving cancer: a quantitative MR imaging study

NASA Astrophysics Data System (ADS)

Reddick, Wilburn E.; Glass, John O.; Shan, Zuyao Y.; Wu, Shengjie; Helton, Susan; Mulhern, Raymond K.

2005-04-01

Due to the inherent risk of central nervous system (CNS) dissemination, children treated for either acute lymphoblastic leukemia (ALL) or malignant brain tumors (BT) receive aggressive CNS therapy. The primary objective of this study was to confirm a previously observed association between reduced volumes of normal-appearing white matter (NAWM) and intellectual and attentional deficits in survivors. A combined MR imaging set consisting of T1, T2, and PD images were collected for 221 children (110 BT; 112 ALL). MR imaging sets were segmented with a hybrid neural network algorithm and volumetric measurements were calculated for five slices centered on the basal ganglia. Summary measures of Overall Index, Omissions, d" (attentiveness), and beta (risk-taking) were derived from the computer-administered Conners" Continuous Performance Test (CPT). Age-corrected estimates of Full-Scale IQ (FSIQ) were also obtained. Pearson correlation analyses were performed between each neurocognitive measure and the volume of NAWM. The correlation between FSIQ and NAWM failed to reach statistical significance for the BT group but was highly significant for the more homogeneous ALL group. Larger Omission rates, decreased attentiveness and more risk taking were significantly associated with lower NAWM volumes in both groups of survivors. Long-term survivors are at increased risk for cognitive delays or deficits, which oftentimes impair future academic performance, employment, and quality of life. These long-term adverse effects of treatment appear to be due to a diminished ability to acquire new information and may be secondary to deficits in attention, which is thought to be supported by interhemispheric and intrahemispheric white matter tracts.

Quantification of Abdominal Fat in Obese and Healthy Adolescents Using 3 Tesla Magnetic Resonance Imaging and Free Software for Image Analysis.

PubMed

Eloi, Juliana Cristina; Epifanio, Matias; de Gonçalves, Marília Maia; Pellicioli, Augusto; Vieira, Patricia Froelich Giora; Dias, Henrique Bregolin; Bruscato, Neide; Soder, Ricardo Bernardi; Santana, João Carlos Batista; Mouzaki, Marialena; Baldisserotto, Matteo

2017-01-01

Computed tomography, which uses ionizing radiation and expensive software packages for analysis of scans, can be used to quantify abdominal fat. The objective of this study is to measure abdominal fat with 3T MRI using free software for image analysis and to correlate these findings with anthropometric and laboratory parameters in adolescents. This prospective observational study included 24 overweight/obese and 33 healthy adolescents (mean age 16.55 years). All participants underwent abdominal MRI exams. Visceral and subcutaneous fat area and percentage were correlated with anthropometric parameters, lipid profile, glucose metabolism, and insulin resistance. Student's t test and Mann-Whitney's test was applied. Pearson's chi-square test was used to compare proportions. To determine associations Pearson's linear correlation or Spearman's correlation were used. In both groups, waist circumference (WC) was associated with visceral fat area (P = 0.001 and P = 0.01 respectively), and triglycerides were associated with fat percentage (P = 0.046 and P = 0.071 respectively). In obese individuals, total cholesterol/HDL ratio was associated with visceral fat area (P = 0.03) and percentage (P = 0.09), and insulin and HOMA-IR were associated with visceral fat area (P = 0.001) and percentage (P = 0.005). 3T MRI can provide reliable and good quality images for quantification of visceral and subcutaneous fat by using a free software package. The results demonstrate that WC is a good predictor of visceral fat in obese adolescents and visceral fat area is associated with total cholesterol/HDL ratio, insulin and HOMA-IR.

Potential of fluid-attenuated inversion recovery (FLAIR) in identification of temporomandibular joint effusion compared with T2-weighted images.

PubMed

Imoto, Kenichi; Otonari-Yamamoto, Mika; Nishikawa, Keiichi; Sano, Tsukasa; Yamamoto, Aya

2011-08-01

The purpose of this study was to determine the potential of fluid-attenuated inversion recovery (FLAIR) sequence images in the identification of joint effusion (JE) compared with T2-weighted images. A total of 31 joints (28 patients) with JE were investigated by magnetic resonance imaging (MRI). Regions of interest were placed over JE, cerebrospinal fluid (CSF), and gray matter (GM) on T2-weighted and FLAIR images and their signal intensities compared. The signal intensity ratios (SIRs) of JE and CSF were calculated with GM as the reference point. The Pearson product-moment correlation coefficient was used for the statistical analysis. The SIR of JE showed a strong correlation between T2-weighted and FLAIR images. However, no correlation was observed for CSF. The average suppression ratio for JE was lower than that for CSF. MRI using FLAIR sequences revealed that JE was not just water content, but a fluid accumulation containing elements such as protein. Further studies are needed, and FLAIR sequences could be useful for the diagnosis of pain and symptoms of the temporomandibular joint (TMJ). Copyright © 2011 Mosby, Inc. All rights reserved.

3T deep gray matter T2 hypointensity correlates with disability over time in stable relapsing-remitting multiple sclerosis: a 3-year pilot study.

PubMed

Zhang, Y; Metz, L M; Yong, V W; Mitchell, J R

2010-10-15

Abnormally decreased deep gray matter (GM) signal intensity on T2-weighted MRI (T2 hypointensity) is associated with brain atrophy and disability progression in patients with multiple sclerosis (MS) and is believed to represent excessive iron deposition. We investigated the time course of deep GM T2 hypointensity and its relationship with disability at 3T in 8 stable relapsing-remitting (RR) MS patients treated with minocycline over 3years. MRI and disability measurements were compared at baseline, 6, 12, 24, and 36months. Grand mean deep GM T2 hypointensity was negatively correlated with EDSS over time (r=-0.94, P=0.02). This correlation was strongest in the head of caudate (r=-0.95, P=0.01) and putamen (r=-0.89, P=0.04). Additionally, baseline grand mean deep GM T2 hypointensity appears to predict third year EDSS (r=-0.72, P=0.04). These results suggest that iron associated deep GM injury correlates with patient disability in stable RRMS. Measurements of deep GM T2 hypointensity at high field MRI may prove to be useful in monitoring individuals with MS. Further studies are required to confirm these results in a large sample and to determine if T2 hypointensity changes in clinically active MS patients. Copyright 2010 Elsevier B.V. All rights reserved.

Multi-model Analysis of Diffusion-weighted Imaging of Normal Testes at 3.0 T: Preliminary Findings.

PubMed

Min, Xiangde; Feng, Zhaoyan; Wang, Liang; Cai, Jie; Li, Basen; Ke, Zan; Zhang, Peipei; You, Huijuan; Yan, Xu

2018-04-01

This study aimed to establish diffusion quantitative parameters (apparent diffusion coefficient [ADC], DDC, α, D app , and K app ) in normal testes at 3.0 T. Sixty-four healthy volunteers in two age groups (A: 10-39 years; B: ≥ 40 years) underwent diffusion-weighted imaging scanning at 3.0 T. ADC 1000 , ADC 2000 , ADC 3000 , DDC, α, D app , and K app were calculated using the mono-exponential, stretched-exponential, and kurtosis models. The correlations between parameters and the age were analyzed. The parameters were compared between the age groups and between the right and the left testes. The average ADC 1000 , ADC 2000 , ADC 3000 , DDC, α, D app , and K app values did not significantly differ between the right and the left testes (P > .05 for all). The following significant correlations were found: positive correlations between age and testicular ADC 1000 , ADC 2000 , ADC 3000 , DDC, and D app (r = 0.516, 0.518, 0.518, 0.521, and 0.516, respectively; P < .01 for all) and negative correlations between age and testicular α and K app (r = -0.363, -0.427, respectively; P < .01 for both). Compared to group B, in group A, ADC 1000 , ADC 2000 , ADC 3000 , DDC, and D app were significantly lower (P < .05 for all), but α and K app were significantly higher (P < .05 for both). Our study demonstrated the applicability of the testicular mono-exponential, stretched-exponential, and kurtosis models. Our results can help establish a baseline for the normal testicular parameters in these diffusion models. The contralateral normal testis can serve as a suitable reference for evaluating the abnormalities of the other side. The effect of age on these parameters requires further attention. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Relationship between the Wide Range Achievement Test 3 and the Wechsler Individual Achievement Test.

PubMed

Smith, T D; Smith, B L

1998-12-01

The present study examined the relationship between the Wide Range Achievement Test 3 and the Wechsler Individual Achievement Test for a sample of children with learning disabilities in two rural school districts. Data were collected for 87 school children who had been classified as learning disabled and placed in special education resource services. Pearson product-moment correlations between scores on the two measures were significant and moderate to high; however, mean scores were not significantly different on Reading, Spelling, and Arithmetic subtests of the Wide Range Achievement Test 3 compared to those for the basic Reading, Spelling, and Mathematics Reasoning subtests of the Wechsler Individual Achievement Test. Although there were significant mean differences between scores on Reading and Reading Comprehension and on Arithmetic and Numerical Operations, magnitudes were small. It appears that the two tests provide similar results when screening for reading, spelling, and arithmetic.

Pearson disease in an infant presenting with severe hypoplastic anemia, normal pancreatic function, and progressive liver failure.

PubMed

Shapira, Adi; Konopnicki, Muriel; Hammad-Saied, Mohammed; Shabad, Evelyn

2014-07-01

Pearson disease is a rare, usually fatal, mitochondrial disorder affecting primarily the bone marrow and the exocrine pancreas. We report a previously healthy 10-week-old girl who presented with profound macrocytic anemia followed by pancytopenia, synthetic liver dysfunction with liver steatosis, and metabolic acidosis with high lactate levels. She had no pancreatic involvement. Multiple cytoplasmic vacuoles in myelocytes and monocytes were seen upon microscopic evaluation of the bone marrow. Genetic analysis of the mitochondrial genome revealed a 5 kbp deletion, thus establishing the diagnosis of Pearson disease.

Primary hypolactasia diagnosis: Comparison between the gaxilose test, shortened lactose tolerance test, and clinical parameters corresponding to the C/T-13910 polymorphism.

PubMed

Domínguez Jiménez, José Luis; Fernández Suárez, Antonio; Muñoz Colmenero, Aurora Úrsula; Fatela Cantillo, Daniel; López Pelayo, Iratxe

2017-04-01

There is no consensus on the most accurate method to diagnose primary hypolactasia. We aimed to compare the diagnostic accuracy of the new gaxilose test with 2 traditional tests (lactose tolerance test and clinical criteria) for the diagnosis of primary hypolactasia using the C/T-13910 polymorphism as a reference standard. Patients with a clinical suspicion of lactose intolerance were subjected to gaxilose tests, shortened lactose tolerance tests, and symptom questionnaires before and after overload with 50 g lactose and after a lactose-free diet. The diagnostic accuracy and degree of agreement and correlation were assessed using a genetic test (C/T-13910 polymorphism) as a reference standard and their respective 95% confidence intervals. Thirty consecutive patients (70% women) participated in the study. The genetic test confirmed the C/T-13910 polymorphism in 11 patients (36.8%). The presence of diarrhoea and the symptom score after lactose overload, along with the tolerance test, were the variables with the highest degree of agreement (κ > 0.60). Area under the ROC curve was >0.82 (p < 0.05), with sensitivity and specificity values of >0.80. However, the gaxilose test obtained lower values: κ, 0.47; area under curve, 0.75 (0.57-0.94); sensitivity, 0.82 (0.55-1); and specificity, 0.68 (0.45-0.92). The multivariate analysis showed an association between the post-overload symptom questionnaire and the results of the genetic test (odds ratio: 1.17; 1.04-1.31; p < 0.01). The presence of diarrhoea and the symptom score after overload with 50 g lactose showed a higher degree of agreement and diagnostic accuracy for primary hypolactasia than the gaxilose test when the genetic test is used as a reference standard. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Early Articular Cartilage MRI T2 Changes After Anterior Cruciate Ligament Reconstruction Correlate With Later Changes in T2 and Cartilage Thickness

PubMed Central

Williams, Ashley; Winalski, Carl S.; Chu, Constance R.

2018-01-01

Anterior cruciate ligament (ACL) injury is a known risk factor for future development of osteoarthritis (OA). This human clinical study seeks to determine if early changes to cartilage MRI T2 maps between baseline and 6 months following ACL reconstruction (ACLR) are associated with changes to cartilage T2 and cartilage thickness between baseline and 2 years after ACLR. Changes to T2 texture metrics and T2 mean values in medial knee cartilage of 17 human subjects 6 months after ACLR were compared to 2-year changes in T2 and in cartilage thickness of the same areas. T2 texture and mean assessments were also compared to that of 11 uninjured controls. In ACLR subjects, six-month changes in mean T2 correlated to 2-year changes in mean T2 (R = 0.80, p = 0.0001), and 6-month changes to T2 texture metrics, but not T2 mean, correlated with 2-year changes in medial femoral cartilage thickness in 9 of the 20 texture features assessed (R = 0.48–0.72, p ≤ 0.05). Both mean T2 and texture differed (p < 0.05) between ALCR subjects and uninjured controls. Clinical Significance These results show that short-term longitudinal evaluation of T2 map and textural changes may provide early warning of cartilage at risk for progressive degeneration after ACL injury and reconstruction. PMID:27381512

Biostatistics Series Module 6: Correlation and Linear Regression.

PubMed

Hazra, Avijit; Gogtay, Nithya

2016-01-01

Correlation and linear regression are the most commonly used techniques for quantifying the association between two numeric variables. Correlation quantifies the strength of the linear relationship between paired variables, expressing this as a correlation coefficient. If both variables x and y are normally distributed, we calculate Pearson's correlation coefficient ( r ). If normality assumption is not met for one or both variables in a correlation analysis, a rank correlation coefficient, such as Spearman's rho (ρ) may be calculated. A hypothesis test of correlation tests whether the linear relationship between the two variables holds in the underlying population, in which case it returns a P < 0.05. A 95% confidence interval of the correlation coefficient can also be calculated for an idea of the correlation in the population. The value r 2 denotes the proportion of the variability of the dependent variable y that can be attributed to its linear relation with the independent variable x and is called the coefficient of determination. Linear regression is a technique that attempts to link two correlated variables x and y in the form of a mathematical equation ( y = a + bx ), such that given the value of one variable the other may be predicted. In general, the method of least squares is applied to obtain the equation of the regression line. Correlation and linear regression analysis are based on certain assumptions pertaining to the data sets. If these assumptions are not met, misleading conclusions may be drawn. The first assumption is that of linear relationship between the two variables. A scatter plot is essential before embarking on any correlation-regression analysis to show that this is indeed the case. Outliers or clustering within data sets can distort the correlation coefficient value. Finally, it is vital to remember that though strong correlation can be a pointer toward causation, the two are not synonymous.

Biostatistics Series Module 6: Correlation and Linear Regression

PubMed Central

Hazra, Avijit; Gogtay, Nithya

2016-01-01

Correlation and linear regression are the most commonly used techniques for quantifying the association between two numeric variables. Correlation quantifies the strength of the linear relationship between paired variables, expressing this as a correlation coefficient. If both variables x and y are normally distributed, we calculate Pearson's correlation coefficient (r). If normality assumption is not met for one or both variables in a correlation analysis, a rank correlation coefficient, such as Spearman's rho (ρ) may be calculated. A hypothesis test of correlation tests whether the linear relationship between the two variables holds in the underlying population, in which case it returns a P < 0.05. A 95% confidence interval of the correlation coefficient can also be calculated for an idea of the correlation in the population. The value r2 denotes the proportion of the variability of the dependent variable y that can be attributed to its linear relation with the independent variable x and is called the coefficient of determination. Linear regression is a technique that attempts to link two correlated variables x and y in the form of a mathematical equation (y = a + bx), such that given the value of one variable the other may be predicted. In general, the method of least squares is applied to obtain the equation of the regression line. Correlation and linear regression analysis are based on certain assumptions pertaining to the data sets. If these assumptions are not met, misleading conclusions may be drawn. The first assumption is that of linear relationship between the two variables. A scatter plot is essential before embarking on any correlation-regression analysis to show that this is indeed the case. Outliers or clustering within data sets can distort the correlation coefficient value. Finally, it is vital to remember that though strong correlation can be a pointer toward causation, the two are not synonymous. PMID:27904175

Energy system contribution in a maximal incremental test: correlations with pacing and overall performance in a 10-km running trial.

PubMed

Damasceno, M V; Pasqua, L A; Lima-Silva, A E; Bertuzzi, R

2015-11-01

This study aimed to verify the association between the contribution of energy systems during an incremental exercise test (IET), pacing, and performance during a 10-km running time trial. Thirteen male recreational runners completed an incremental exercise test on a treadmill to determine the respiratory compensation point (RCP), maximal oxygen uptake (V˙O2max), peak treadmill speed (PTS), and energy systems contribution; and a 10-km running time trial (T10-km) to determine endurance performance. The fractions of the aerobic (WAER) and glycolytic (WGLYCOL) contributions were calculated for each stage based on the oxygen uptake and the oxygen energy equivalents derived by blood lactate accumulation, respectively. Total metabolic demand (WTOTAL) was the sum of these two energy systems. Endurance performance during the T10-km was moderately correlated with RCP, V˙O2max and PTS (P<@0.05), and moderate-to-highly correlated with WAER, WGLYCOL, and WTOTAL (P<0.05). In addition, WAER, WGLYCOL, and WTOTAL were also significantly correlated with running speed in the middle (P<0.01) and final (P<0.01) sections of the T10-km. These findings suggest that the assessment of energy contribution during IET is potentially useful as an alternative variable in the evaluation of endurance runners, especially because of its relationship with specific parts of a long-distance race.

Quantification and Correlation of Angiogenesis with Macrophages by Histomorphometric Method in Central and Peripheral Giant Cell Granuloma: An Immunohistochemical Analysis.

PubMed

Kumar, Varsha Vimal; Krishanappa, Savita Jangal; Prakash, Smitha Gowdra; Channabasaviah, Girish Hemdal; Murgod, Sanjay; Pujari, Ravikumar; Kamat, Mamata Sharad

2016-03-01

Angiogenesis is a fundamental process that affects physiologic reactions and pathological processes such as tumour development and metastasis. It is the process of formation of new microvessel from the preexisting vessels. The purpose of this study was to evaluate angiogenesis, macrophage index and correlate the impact of macrophages on angiogenesis in the central and peripheral giant cell granulomas by evaluating immunohistochemically microvessel density, microvessel perimeter and macrophage index. Immunohistochemical analysis was carried on 20 cases of central and peripheral giant cell granulomas each for CD34 and CD68 proteins expression. Inferential statistical analysis was performed using Independent student t-test to assess the microvessel density, microvessel perimeter and macrophage index on continuous scale between Group I and Group II. Level of significance was determined at 5%. Further bivariate analysis using Pearson correlation test was carried out to see the relationship between microvessel density and macrophage index in each group. Microvessel density, micro vessel perimeter and macrophage index was higher in central giant cell granuloma compared to that of peripheral giant cell granuloma. Correlation between microvessel density and macrophage index among these two lesions was statistically insignificant. Angiogenesis as well as the number of macrophages appeared to increase in Central Giant Cell Granuloma in present study. These findings suggest that macrophages may up regulate the angiogenesis in these giant cell granulomas and angiogenesis do have a role in clinical behaviour. However, we could not establish a positive correlation between microvessel density and macrophage index as the values were statistically insignificant. This insignificance may be presumed due to fewer samples taken for study.

Gene Expression and Correlation of Pten and Fabp4 in Liver, Muscle, and Adipose Tissues of Type 2 Diabetes Rats.

PubMed

Su, Di; Zhang, Chuan-Ling; Gao, Ying-Chun; Liu, Xiao-Ying; Li, Cai-Ping; Huangfu, Jian; Xiao, Rui

2015-11-22

The aim of this work was to study the Fabp4 and Pten gene expression and correlation in the liver, muscle, and adipose tissues of type 2 diabetes mellitus (T2DM) rats. Male Wistar rats (8 weeks old) were randomly divided into 2 groups (n=12/group): a control group fed a normal diet for 8 weeks and an experimental group fed a high-fat, high-sugar diet for 8 weeks and that received 25 mg/kg streptozotocin by intraperitoneal injection to induce T2DM. The random blood glucose, fasting blood glucose, and fasting insulin levels were measured. The expression of Pten and Fabp4 in the liver, muscle, and epididymal adipose tissues was estimated by real-time quantitative PCR. Pearson correlation coefficient analysis was used to investigate the expression correlation between Pten and Fabp4 in T2DM rats. The gene expressions of Pten and Fabp4 in the liver, muscle, and adipose tissues of T2DM rats were all significantly higher than those in the control group (P<0.05). Pten was highly expressed in the muscles and Fabp4 was highly expressed in muscle and adipose tissues. Furthermore, expressions of Fabp4 and Pten in the muscle and adipose tissues of T2DM rats were positively correlated (P<0.05), but not in the liver. The increased expression of PTEN and FABP4 in the adipose and muscles of T2DM rats may play an important role in the insulin resistance of T2DM. However, the mechanism by which these 2 genes function in T2DM needs further study.

Test wells T21, T22, and T25, White Sands Missile Range, Dona Ana County, New Mexico

USGS Publications Warehouse

Myers, R.G.

1983-01-01

Three test wells, T21, T22, and T25, were drilled at White Sands Missile Range in south-central New Mexico as part of a joint military program sponsored by the U.S. Army in September 1982. T21 and T22 were drilled as observation wells for two old landfills. T25 was drilled as an exploratory hole to obtain lithologic and borehole-geophysical data in the vicinity of the proposed replacement well for Supply Well 15. Information obtained from these wells includes borehole-geophysical and driller's logs.

A free software for the calculation of T2* values for iron overload assessment.

PubMed

Fernandes, Juliano Lara; Fioravante, Luciana Andrea Barozi; Verissimo, Monica P; Loggetto, Sandra R

2017-06-01

Background Iron overload assessment with magnetic resonance imaging (MRI) using T2* has become a key diagnostic method in the management of many diseases. Quantitative analysis of the MRI images with a cost-effective tool has been a limitation to increased use of the method. Purpose To provide a free software solution for this purpose comparing the results with a commercial solution. Material and Methods The free tool was developed as a standalone program to be directly downloaded and ran in a common personal computer platform without the need of a dedicated workstation. Liver and cardiac T2* values were calculated using both tools and the values obtained compared between them in a group of 56 patients with suspected iron overload using Bland-Altman plots and concordance correlation coefficients (CCC). Results In the heart, the mean T2* differences between the two methods was 0.46 ms (95% confidence interval [CI], -0.037 -0.965) and in the liver 0.49 ms (95% CI, 0.257-0.722). The CCC for both the heart and the liver were significantly high (0.98 [95% CI, 0.966-0.988] with a Pearson ρ of 0.9811 and 0.991 [95% CI, 0.986-0.994] with a Pearson ρ of 0.996, respectively. No significant differences were observed when analyzing only patients with abnormal concentrations of iron in both organs compared to the whole cohort. Conclusion The proposed free software tool is accurate for calculation of T2* values of the liver and heart and might be a solution for centers that cannot use paid commercial solutions.

Correlation between quantified breast densities from digital mammography and 18F-FDG PET uptake.

PubMed

Lakhani, Paras; Maidment, Andrew D A; Weinstein, Susan P; Kung, Justin W; Alavi, Abass

2009-01-01

To correlate breast density quantified from digital mammograms with mean and maximum standardized uptake values (SUVs) from positron emission tomography (PET). This was a prospective study that included 56 women with a history of suspicion of breast cancer (mean age 49.2 +/- 9.3 years), who underwent 18F-fluoro-2-deoxyglucose (FDG)-PET imaging of their breasts as well as digital mammography. A computer thresholding algorithm was applied to the contralateral nonmalignant breasts to quantitatively estimate the breast density on digital mammograms. The breasts were also classified into one of four Breast Imaging Reporting and Data System categories for density. Comparisons between SUV and breast density were made using linear regression and the Student's t-test. Linear regression of mean SUV versus average breast density showed a positive relationship with a Pearson's correlation coefficient of R(2) = 0.83. The quantified breast densities and mean SUVs were significantly greater for mammographically dense than nondense breasts (p < 0.0001 for both). The average quantified densities and mean SUVs of the breasts were significantly greater for premenopausal than postmenopausal patients (p < 0.05). 8/51 (16%) of the patients had maximum SUVs that equaled 1.6 or greater. There is a positive linear correlation between quantified breast density on digital mammography and FDG uptake on PET. Menopausal status affects the metabolic activity of normal breast tissue, resulting in higher SUVs in pre- versus postmenopausal patients.

Pro-Brain Natriuretic Peptide and Troponin T-Hypersensitivity Levels Correlate With the Severity of Liver Dysfunction in Liver Cirrhosis.

PubMed

Zhao, Jiancheng; Li, Sai; Ren, Linan; Guo, Xiaozhong; Qi, Xingshun

2017-08-01

Increased pro-brain natriuretic peptide (pro-BNP) or troponin T-hypersensitivity (TnT-HSST) levels are common in liver cirrhosis. We conducted a retrospective observational study aimed to evaluate the correlation of pro-BNP and TnT-HSST levels with the clinical characteristics, laboratory data and in-hospital outcomes of patients with liver cirrhosis. We selected cirrhotic patients admitted to our hospital between January 2011 and June 2014. All eligible patients had pro-BNP or TnT-HSST data, or both. The pro-BNP and TnT-HSST data were further divided according to the presence of cardiac diseases. The prevalence of pro-BNP level >900pg/mL was 41.72% (63 of 151 patients). The prevalence of TnT-HSST level >0.05ng/mL was 11.22% (45 of 401 patients). In the overall analysis, pro-BNP level significantly correlated with red blood cell (RBC), platelet, ascites, blood urea nitrogen (BUN), creatinine (Cr), Child-Pugh score, model for end-stage liver disease (MELD) score and in-hospital death; TnT-HSST level significantly correlated with white blood cell, ascites, albumin (ALB), BUN, Cr, Child-Pugh score, MELD score and in-hospital death. In patients with cardiac diseases, pro-BNP level significantly correlated with RBC, ascites, BUN, Cr, Child-Pugh score and MELD score; TnT-HSST level significantly correlated with sex, ascites, white blood cell, ALB, BUN, Cr, Child-Pugh score, MELD score and in-hospital death. In patients without cardiac diseases, pro-BNP level significantly correlated with ascites, RBC, platelet, BUN, Cr, MELD score and in-hospital death; TnT-HSST level significantly correlated with age, ascites, RBC, ALB, BUN, Cr, Child-Pugh score, MELD score and in-hospital death. Pro-BNP and TnT-HSST levels significantly correlated with the severity of liver dysfunction and in-hospital mortality in cirrhosis. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Metacognitive Ability Relationship with Test Result of Senior High School of Biology Teacher Competence in Sijunjung District

NASA Astrophysics Data System (ADS)

Ardi, A.; Fadilah, M.; Ichsani, W.

2018-04-01

This research aimed to reveal how the relationship between metacognitive ability and the test result of biology teacher competence in Sijunjung District. The population of this descriptive research were all high school biology teachers in Sijunjung District, and sample is all teachers who are members of the population, which is 23 biology teachers. The instrument used in this research are a questionnaire of research on teacher's metacognitive ability and document about teacher competence test result. The questionnaire was validated first by two lecturers of biology and one lecturer of English. Data analysis using Pearson Product Moment's. Based on the results of research and discussion that have been described, it can generally be concluded that there is a low relationship between metacognitive ability with competence test results of high school biology teachers in Sijunjung District. Partially, the relationship of metacognitive ability with the test result of professional competence of biology teacher showed significant result, with correlation coefficient 0,46 and t table 1,72 while titung 2,37. The contribution of metacognitive ability to the competence test result of the teacher is 21.6%, while the other 78.4% have not been revealed in this research.

Correlation and Reliability of Cervical Sagittal Alignment Parameters between Lateral Cervical Radiograph and Lateral Whole-Body EOS Stereoradiograph.

PubMed

Singhatanadgige, Weerasak; Kang, Daniel G; Luksanapruksa, Panya; Peters, Colleen; Riew, K Daniel

2016-09-01

Retrospective analysis. To evaluate the correlation and reliability of cervical sagittal alignment parameters obtained from lateral cervical radiographs (XRs) compared with lateral whole-body stereoradiographs (SRs). We evaluated adults with cervical deformity using both lateral XRs and lateral SRs obtained within 1 week of each other between 2010 and 2014. XR and SR images were measured by two independent spine surgeons using the following sagittal alignment parameters: C2-C7 sagittal Cobb angle (SCA), C2-C7 sagittal vertical axis (SVA), C1-C7 translational distance (C1-7), T1 slope (T1-S), neck tilt (NT), and thoracic inlet angle (TIA). Pearson correlation and paired t test were used for statistical analysis, with intra- and interrater reliability analyzed using intraclass correlation coefficient (ICC). A total of 35 patients were included in the study. We found excellent intrarater reliability for all sagittal alignment parameters in both the XR and SR groups with ICC ranging from 0.799 to 0.994 for XR and 0.791 to 0.995 for SR. Interrater reliability was also excellent for all parameters except NT and TIA, which had fair reliability. We also found excellent correlations between XR and SR measurements for most sagittal alignment parameters; SCA, SVA, and C1-C7 had r > 0.90, and only NT had r < 0.70. There was a significant difference between groups, with SR having lower measurements compared with XR for both SVA (0.68 cm lower, p < 0.001) and C1-C7 (1.02 cm lower, p < 0.001). There were no differences between groups for SCA, T1-S, NT, and TIA. Whole-body stereoradiography appears to be a viable alternative for measuring cervical sagittal alignment parameters compared with standard radiography. XR and SR demonstrated excellent correlation for most sagittal alignment parameters except NT. However, SR had significantly lower average SVA and C1-C7 measurements than XR. The lower radiation exposure using single SR has to be weighed against its

Jordanian Men's and Women's Attitudes Toward Intimate Partner Violence and Its Correlates With Family Functioning and Demographics.

PubMed

Alzoubi, Fatmeh Ahmad; Ali, Reem Ahmad

2018-04-01

Jordan is a developing country in the Middle East and, much like other countries in the world, has high rates of intimate partner violence (IPV). Little information is available on Jordanian men's and women's attitudes toward IPV. The purpose of this study is to examine men's and women's attitudes toward IPV in Jordan and its relationship with some demographics and family functioning. A descriptive cross-sectional correlational design with a sample of 401 men and women was used. Descriptive statistics ( M, SD), Pearson r, t test, and ANOVA were used. The results indicated that Jordanian men and women have a lower score of IPVAS, 40.06 ( SD = 8.20), indicating lower acceptance of IPV compared with the literature. Family functioning was 3.12 ( SD = 0.46), indicating more healthy families. Family functioning was negatively correlated with IPVAS scores ( r = -.22, p = .00). All demographic variables showed small to moderate correlations with IPVAS. Education for both study participants and their spouses had a negative correlation with IPVAS ( r = -.27, p = .00) and ( r = -.20, p = .00), respectively. Male participants, individuals who were living with extended family, and those living in rural areas had significantly high IPVAS scores, indicating more accepting attitudes toward IPV. Practitioners should provide families with education on the methods of conflict resolution, effective communication within the family, problem-solving approaches, equal role distribution, and appropriate styles of establishing a family.

Test wells T27 and T28, White Sands Missile Range, Dona Ana County, New Mexico

USGS Publications Warehouse

Myers, R.G.; Pinckley, K.M.

1985-01-01

Two test wells, T27 and T28, were drilled at White Sands Missile Range in south-central New Mexico as part of a joint military training program sponsored by the U.S. Army in February and March 1983. Test wells T27 and T28 were drilled as observation wells in the vicinity of the Liquid Propellant Storage Area. Information obtained from these wells includes lithologic logs, driller 's logs, and borehole-geophysical logs from the cased wells. (USGS)

Recent advances on terrain database correlation testing

NASA Astrophysics Data System (ADS)

Sakude, Milton T.; Schiavone, Guy A.; Morelos-Borja, Hector; Martin, Glenn; Cortes, Art

1998-08-01

Terrain database correlation is a major requirement for interoperability in distributed simulation. There are numerous situations in which terrain database correlation problems can occur that, in turn, lead to lack of interoperability in distributed training simulations. Examples are the use of different run-time terrain databases derived from inconsistent on source data, the use of different resolutions, and the use of different data models between databases for both terrain and culture data. IST has been developing a suite of software tools, named ZCAP, to address terrain database interoperability issues. In this paper we discuss recent enhancements made to this suite, including improved algorithms for sampling and calculating line-of-sight, an improved method for measuring terrain roughness, and the application of a sparse matrix method to the terrain remediation solution developed at the Visual Systems Lab of the Institute for Simulation and Training. We review the application of some of these new algorithms to the terrain correlation measurement processes. The application of these new algorithms improves our support for very large terrain databases, and provides the capability for performing test replications to estimate the sampling error of the tests. With this set of tools, a user can quantitatively assess the degree of correlation between large terrain databases.

The test-retest reliability and criterion validity of a high-intensity, netball-specific circuit test: The Net-Test.

PubMed

Mungovan, Sean F; Peralta, Paula J; Gass, Gregory C; Scanlan, Aaron T

2018-04-12

To examine the test-retest reliability and criterion validity of a high-intensity, netball-specific fitness test. Repeated measures, within-subject design. Eighteen female netball players competing in an international competition completed a trial of the Net-Test, which consists of 14 timed netball-specific movements. Players also completed a series of netball-relevant criterion fitness tests. Ten players completed an additional Net-Test trial one week later to assess test-retest reliability using intraclass correlation coefficient (ICC), typical error of measurement (TEM), and coefficient of variation (CV). The typical error of estimate expressed as CV and Pearson correlations were calculated between each criterion test and Net-Test performance to assess criterion validity. Five movements during the Net-Test displayed moderate ICC (0.84-0.90) and two movements displayed high ICC (0.91-0.93). Seven movements and heart rate taken during the Net-Test held low CV (<5%) with values ranging from 1.7 to 9.5% across measures. Total time (41.63±2.05s) during the Net-Test possessed low CV and significant (p<0.05) correlations with 10m sprint time (1.98±0.12s; CV=4.4%, r=0.72), 20m sprint time (3.38±0.19s; CV=3.9%, r=0.79), 505 Change-of-Direction time (2.47±0.08s; CV=2.0%, r=0.80); and maximum oxygen uptake (46.59±2.58 mLkg -1 min -1 ; CV=4.5%, r=-0.66). The Net-Test possesses acceptable reliability for the assessment of netball fitness. Further, the high criterion validity for the Net-Test suggests a range of important netball-specific fitness elements are assessed in combination. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Memory Alteration Test to Detect Amnestic Mild Cognitive Impairment and Early Alzheimer's Dementia in Population with Low Educational Level.

PubMed

Custodio, Nilton; Lira, David; Herrera-Perez, Eder; Montesinos, Rosa; Castro-Suarez, Sheila; Cuenca-Alfaro, José; Valeriano-Lorenzo, Lucía

2017-01-01

Background/Aims : Short tests to early detection of the cognitive impairment are necessary in primary care setting, particularly in populations with low educational level. The aim of this study was to assess the performance of Memory Alteration Test (M@T) to discriminate controls, patients with amnestic Mild Cognitive Impairment (aMCI) and patients with early Alzheimer's Dementia (AD) in a sample of individuals with low level of education. Methods : Cross-sectional study to assess the performance of the M@T (study test), compared to the neuropsychological evaluation (gold standard test) scores in 247 elderly subjects with low education level from Lima-Peru. The cognitive evaluation included three sequential stages: (1) screening (to detect cases with cognitive impairment); (2) nosological diagnosis (to determinate specific disease); and (3) classification (to differentiate disease subtypes). The subjects with negative results for all stages were considered as cognitively normal (controls). The test performance was assessed by means of area under the receiver operating characteristic (ROC) curve. We calculated validity measures (sensitivity, specificity and correctly classified percentage), the internal consistency (Cronbach's alpha coefficient), and concurrent validity (Pearson's ratio coefficient between the M@T and Clinical Dementia Rating (CDR) scores). Results : The Cronbach's alpha coefficient was 0.79 and Pearson's ratio coefficient was 0.79 ( p < 0.01). The AUC of M@T to discriminate between early AD and aMCI was 99.60% (sensitivity = 100.00%, specificity = 97.53% and correctly classified = 98.41%) and to discriminate between aMCI and controls was 99.56% (sensitivity = 99.17%, specificity = 91.11%, and correctly classified = 96.99%). Conclusions : The M@T is a short test with a good performance to discriminate controls, aMCI and early AD in individuals with low level of education from urban settings.

Psychometric Testing of the Chinese-Version Glover-Nilsson Smoking Behavioral Questionnaire (GN-SBQ-C) for the Identification of Nicotine Dependence in Adult Smokers in Taiwan.

PubMed

Chen, Shu-Ching; Chen, Hsiu-Fang; Peng, Hsi-Ling; Lee, Li-Yun; Chiang, Ting-Yu; Chiu, Hui-Chuan

2017-04-01

The purposes of this study were to evaluate the psychometric properties, reliability, and validity of the Chinese-version Glover-Nilsson Smoking Behavioral Questionnaire (GN-SBQ-C) and assess the behavioral nicotine dependence among community-dwelling adult smokers in Taiwan. The methods used were survey design, administration, and validation. A total of 202 adult smokers completed a survey to assess behavioral dependence, nicotine dependence, depression, social support, and demographic and smoking characteristics. Data analysis included descriptive statistics, internal consistency reliability, t test, exploratory factor analysis, independent t test, and Pearson product moment correlation. The results showed that (1) the GN-SBQ-C has good internal consistency reliability and stability (2-week test-retest reliability); (2) the extracted one factor explained 41.80 % of the variance, indicating construct validity; (3) the scale has acceptable concurrent validity, with significant positive correlation between the GN-SBQ-C and nicotine dependence, depression, and time smoking and negative correlation between the GN-SBQ-C and age and exercise habit; and (4) the instrument has discriminant validity, supported by significant differences between those with high and low-to-moderate nicotine dependence, smokers greater than 43 years old and those 43 years old and younger, and those who smoked 10 years or less and those smoking more than 10 years. The 11-item GN-SBQ-C has satisfactory psychometric properties when applied in a sample of Taiwanese adult smokers. The scale is feasible and valid to use to assess smoking behavioral dependence.

Lack of correlation between left ventricular outflow tract velocity time integral and stroke volume index in mechanically ventilated patients.

PubMed

Blancas, R; Martínez-González, Ó; Ballesteros, D; Núñez, A; Luján, J; Rodríguez-Serrano, D; Hernández, A; Martínez-Díaz, C; Parra, C M; Matamala, B L; Alonso, M A; Chana, M

2018-02-07

To assess the correlation between left ventricular outflow tract velocity time integral (LVOT VTI) and stroke volume index (SVI) calculated by thermodilution methods in ventilated critically ill patients. A prospective, descriptive, multicenter study was performed. Five intensive care units from university hospitals. Patients older than 17 years needing mechanical ventilation and invasive hemodynamic monitoring were included. LVOT VTI was measured by pulsatile Doppler echocardiography. Calculations of SVI were performed through a floating pulmonary artery catheter (PAC) or a Pulse index Contour Cardiac Output (PiCCO ® ) thermodilution methods. The relation between LVOT VTI and SVI was tested by linear regression analysis. One hundred and fifty-six paired measurements were compared. Mean LVOT VTI was 20.83±4.86cm and mean SVI was 41.55±9.55mL/m 2 . Pearson correlation index for these variables was r=0.644, p<0.001; ICC was 0.52 (CI 95% 0.4-0.63). When maximum LVOT VTI was correlated with SVI, Pearson correlation index was r=0.62, p<0.001. Correlation worsened for extreme values, especially for those with higher LVOT VTI. LVOT VTI could be a complementary hemodynamic evaluation in selected patients, but does not eliminate the need for invasive monitoring at the present time. The weak correlation between LVOT VTI and invasive monitoring deserves additional assessment to identify the factors affecting this disagreement. Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

NASA Technical Reports Server (NTRS)

Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

2011-01-01

Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

Lymph node and circulating T cell characteristics are strongly correlated in end-stage renal disease patients, but highly differentiated T cells reside within the circulation.

PubMed

Dedeoglu, B; de Weerd, A E; Huang, L; Langerak, A W; Dor, F J; Klepper, M; Verschoor, W; Reijerkerk, D; Baan, C C; Litjens, N H R; Betjes, M G H

2017-05-01

Ageing is associated with changes in the peripheral T cell immune system, which can be influenced significantly by latent cytomegalovirus (CMV) infection. To what extent changes in circulating T cell populations correlate with T cell composition of the lymph node (LN) is unclear, but is crucial for a comprehensive understanding of the T cell system. T cells from peripheral blood (PB) and LN of end-stage renal disease patients were analysed for frequency of recent thymic emigrants using CD31 expression and T cell receptor excision circle content, relative telomere length and expression of differentiation markers. Compared with PB, LN contained relatively more CD4 + than CD8 + T cells (P < 0·001). The percentage of naive and central memory CD4 + and CD8 + T cells and thymic output parameters showed a strong linear correlation between PB and LN. Highly differentiated CD28 null T cells, being CD27 - , CD57 + or programmed death 1 (PD-1 + ), were found almost exclusively in the circulation but not in LN. An age-related decline in naive CD4 + and CD8 + T cell frequency was observed (P = 0·035 and P = 0·002, respectively) within LN, concomitant with an increase in central memory CD8 + T cells (P = 0·033). Latent CMV infection increased dramatically the frequency of circulating terminally differentiated T cells, but did not alter T cell composition and ageing parameters of LN significantly. Overall T cell composition and measures of thymic function in PB and LN are correlated strongly. However, highly differentiated CD28 null T cells, which may comprise a large part of circulating T cells in CMV-seropositive individuals, are found almost exclusively within the circulation. © 2017 British Society for Immunology.

Biomechanical assessment of dynamic balance: Specificity of different balance tests.

PubMed

Ringhof, Steffen; Stein, Thorsten

2018-04-01

Dynamic balance is vitally important for most sports and activities of daily living, so the assessment of dynamic stability has become an important issue. In consequence, a large number of balance tests have been developed. However, it is not yet known whether these tests (i) measure the same construct and (ii) can differentiate between athletes with different balance expertise. We therefore studied three common dynamic balance tests: one-leg jump landings, Posturomed perturbations and simulated forward falls. Participants were 24 healthy young females in regular training in either gymnastics (n = 12) or swimming (n = 12). In each of the tests, the participants were instructed to recover balance as quickly as possible. Dynamic stability was computed by time to stabilization and margin of stability, deduced from force plates and motion capture respectively. Pearson's correlations between the dynamic balance tests found no significant associations between the respective dynamic stability measures. Furthermore, independent t-tests indicated that only jump landings could properly distinguish between both groups of athletes. In essence, the different dynamic balance tests applied did not measure the same construct but rather task-specific skills, each of which depends on multifactorial internal and external constraints. Our study therefore contradicts the traditional view of considering balance as a general ability, and reinforces that dynamic balance measures are not interchangeable. This highlights the importance of selecting appropriate balance tests. Copyright © 2018 Elsevier B.V. All rights reserved.

Clinical manifestations and enzymatic activities of mitochondrial respiratory chain complexes in Pearson marrow-pancreas syndrome with 3-methylglutaconic aciduria: a case report and literature review.

PubMed

Sato, Takeshi; Muroya, Koji; Hanakawa, Junko; Iwano, Reiko; Asakura, Yumi; Tanaka, Yukichi; Murayama, Kei; Ohtake, Akira; Hasegawa, Tomonobu; Adachi, Masanori

2015-12-01

Pearson marrow-pancreas syndrome (PS) is a rare mitochondrial disorder. Impaired mitochondrial respiratory chain complexes (MRCC) differ among individuals and organs, which accounts for variable clinical pictures. A subset of PS patients develop 3-methylglutaconic aciduria (3-MGA-uria), but the characteristic symptoms and impaired MRCC remain unknown. Our patient, a girl, developed pancytopenia, hyperlactatemia, steatorrhea, insulin-dependent diabetes mellitus, liver dysfunction, Fanconi syndrome, and 3-MGA-uria. She died from cerebral hemorrhage at 3 years of age. We identified a novel 5.4-kbp deletion of mitochondrial DNA. The enzymatic activities of MRCC I and IV were markedly reduced in the liver and muscle and mildly reduced in skin fibroblasts and the heart. To date, urine organic acid analysis has been performed on 29 PS patients, including our case. Eight patients had 3-MGA-uria, while only one patient did not. The remaining 20 patients were not reported to have 3-MGA-uria. In this paper, we included these 20 patients as PS patients without 3-MGA-uria. PS patients with and without 3-MGA-uria have similar manifestations. Only a few studies have examined the enzymatic activities of MRCC. No clinical characteristics distinguish between PS patients with and without 3-MGA-uria. The correlation between 3-MGA-uria and the enzymatic activities of MRCC remains to be elucidated. • The clinical characteristics of patients with Pearson marrow-pancreas syndrome and 3-methylglutaconic aciduria remain unknown. • No clinical characteristics distinguish between Pearson marrow-pancreas syndrome patients with and without 3-methylglutaconic aciduria.

The immediate effect of long-distance running on T2 and T2* relaxation times of articular cartilage of the knee in young healthy adults at 3.0 T MR imaging

PubMed Central

Welsch, Goetz H; Laqmani, Azien; Henes, Frank O; Kaul, Michael G; Schoen, Gerhard; Adam, Gerhard; Regier, Marc

2016-01-01

Objective: To quantitatively assess the immediate effect of long-distance running on T2 and T2* relaxation times of the articular cartilage of the knee at 3.0 T in young healthy adults. Methods: 30 healthy male adults (18–31 years) who perform sports at an amateur level underwent an initial MRI at 3.0 T with T2 weighted [16 echo times (TEs): 9.7–154.6 ms] and T2* weighted (24 TEs: 4.6–53.6 ms) relaxation measurements. Thereafter, all participants performed a 45-min run. After the run, all individuals were immediately re-examined. Data sets were post-processed using dedicated software (ImageJ; National Institute of Health, Bethesda, MD). 22 regions of interest were manually drawn in segmented areas of the femoral, tibial and patellar cartilage. For statistical evaluation, Pearson product–moment correlation coefficients and confidence intervals were computed. Results: Mean initial values were 35.7 ms for T2 and 25.1 ms for T2*. After the run, a significant decrease in the mean T2 and T2* relaxation times was observed for all segments in all participants. A mean decrease of relaxation time was observed for T2 with 4.6 ms (±3.6 ms) and for T2* with 3.6 ms (±5.1 ms) after running. Conclusion: A significant decrease could be observed in all cartilage segments for both biomarkers. Both quantitative techniques, T2 and T2*, seem to be valuable parameters in the evaluation of immediate changes in the cartilage ultrastructure after running. Advances in knowledge: This is the first direct comparison of immediate changes in T2 and T2* relaxation times after running in healthy adults. PMID:27336705

The immediate effect of long-distance running on T2 and T2* relaxation times of articular cartilage of the knee in young healthy adults at 3.0 T MR imaging.

PubMed

Behzadi, Cyrus; Welsch, Goetz H; Laqmani, Azien; Henes, Frank O; Kaul, Michael G; Schoen, Gerhard; Adam, Gerhard; Regier, Marc

2016-08-01

To quantitatively assess the immediate effect of long-distance running on T2 and T2* relaxation times of the articular cartilage of the knee at 3.0 T in young healthy adults. 30 healthy male adults (18-31 years) who perform sports at an amateur level underwent an initial MRI at 3.0 T with T2 weighted [16 echo times (TEs): 9.7-154.6 ms] and T2* weighted (24 TEs: 4.6-53.6 ms) relaxation measurements. Thereafter, all participants performed a 45-min run. After the run, all individuals were immediately re-examined. Data sets were post-processed using dedicated software (ImageJ; National Institute of Health, Bethesda, MD). 22 regions of interest were manually drawn in segmented areas of the femoral, tibial and patellar cartilage. For statistical evaluation, Pearson product-moment correlation coefficients and confidence intervals were computed. Mean initial values were 35.7 ms for T2 and 25.1 ms for T2*. After the run, a significant decrease in the mean T2 and T2* relaxation times was observed for all segments in all participants. A mean decrease of relaxation time was observed for T2 with 4.6 ms (±3.6 ms) and for T2* with 3.6 ms (±5.1 ms) after running. A significant decrease could be observed in all cartilage segments for both biomarkers. Both quantitative techniques, T2 and T2*, seem to be valuable parameters in the evaluation of immediate changes in the cartilage ultrastructure after running. This is the first direct comparison of immediate changes in T2 and T2* relaxation times after running in healthy adults.

An external validation study reporting poor correlation between the claims-based index for rheumatoid arthritis severity and the disease activity score.

PubMed

Desai, Rishi J; Solomon, Daniel H; Weinblatt, Michael E; Shadick, Nancy; Kim, Seoyoung C

2015-04-13

We conducted an external validation study to examine the correlation of a previously published claims-based index for rheumatoid arthritis severity (CIRAS) with disease activity score in 28 joints calculated by using C-reactive protein (DAS28-CRP) and the multi-dimensional health assessment questionnaire (MD-HAQ) physical function score. Patients enrolled in the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) and Medicare were identified and their data from these two sources were linked. For each patient, DAS28-CRP measurement and MD-HAQ physical function scores were extracted from BRASS, and CIRAS was calculated from Medicare claims for the period of 365 days prior to the DAS28-CRP measurement. Pearson correlation coefficient between CIRAS and DAS28-CRP as well as MD-HAQ physical function scores were calculated. Furthermore, we considered several additional pharmacy and medical claims-derived variables as predictors for DAS28-CRP in a multivariable linear regression model in order to assess improvement in the performance of the original CIRAS algorithm. In total, 315 patients with enrollment in both BRASS and Medicare were included in this study. The majority (81%) of the cohort was female, and the mean age was 70 years. The correlation between CIRAS and DAS28-CRP was low (Pearson correlation coefficient = 0.07, P = 0.24). The correlation between the calculated CIRAS and MD-HAQ physical function scores was also found to be low (Pearson correlation coefficient = 0.08, P = 0.17). The linear regression model containing additional claims-derived variables yielded model R(2) of 0.23, suggesting limited ability of this model to explain variation in DAS28-CRP. In a cohort of Medicare-enrolled patients with established RA, CIRAS showed low correlation with DAS28-CRP as well as MD-HAQ physical function scores. Claims-based algorithms for disease activity should be rigorously tested in distinct populations in order to establish

Development of Test-Analysis Models (TAM) for correlation of dynamic test and analysis results

NASA Technical Reports Server (NTRS)

Angelucci, Filippo; Javeed, Mehzad; Mcgowan, Paul

1992-01-01

The primary objective of structural analysis of aerospace applications is to obtain a verified finite element model (FEM). The verified FEM can be used for loads analysis, evaluate structural modifications, or design control systems. Verification of the FEM is generally obtained as the result of correlating test and FEM models. A test analysis model (TAM) is very useful in the correlation process. A TAM is essentially a FEM reduced to the size of the test model, which attempts to preserve the dynamic characteristics of the original FEM in the analysis range of interest. Numerous methods for generating TAMs have been developed in the literature. The major emphasis of this paper is a description of the procedures necessary for creation of the TAM and the correlation of the reduced models with the FEM or the test results. Herein, three methods are discussed, namely Guyan, Improved Reduced System (IRS), and Hybrid. Also included are the procedures for performing these analyses using MSC/NASTRAN. Finally, application of the TAM process is demonstrated with an experimental test configuration of a ten bay cantilevered truss structure.

Review of Pearson Test of English Academic: Building an Assessment Use Argument

ERIC Educational Resources Information Center

Wang, Huan; Choi, Ikkyu; Schmidgall, Jonathan; Bachman, Lyle F.