Ultrasonographic assessment of splenic volume and its correlation with body parameters in a Jordanian population.

PubMed

Badran, Darwish H; Kalbouneh, Heba M; Al-Hadidi, Maher T; Shatarat, Amjad T; Tarawneh, Emad S; Hadidy, Azmy M; Mahafza, Waleed S

2015-08-01

To estimate normal linear dimensions and volume of spleen in Jordanians using ultrasonography, and to correlate splenic volume with age and body parameters: height, weight, body surface area (BSA), and body mass index (BMI). A prospective pilot study was conducted on 205 volunteers (115 males and 90 females) not known to have any conditions likely to be associated with splenomegaly. The study was performed at the Radiology Department, Jordanian University Hospital, Amman, Jordan, between December 2013 and August 2014. All linear dimensions of spleen were measured, and splenic volume (index) was calculated using the standard prolate ellipsoid formula (length × width × depth × 0.523). The splenic volume was then analyzed with age and body parameters using the Pearson's correlation coefficient. The mean (± SD) splenic dimensions were 10.72±1.37 cm in length, 7.40±1.52 cm in width, 4.40±1.47 cm in depth, and 184.15±79.56 cm3 in volume. Men had larger spleens than women (p less than 0.0001). Age had no significant effect on spleen volume (r=0.11, p=0.12). There was a significant moderate positive correlation (p less than 0.0001), using Pearson's correlation coefficient, between the spleen volume, and other parameters (height, weight, BSA, and BMI), with correlation coefficients exceeding 0.3. A local reference of spleen dimensions was established with a different range of values reported previously.

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 their generalizability before widespread adoption.

A model for predicting sulcus-to-sulcus diameter in posterior chamber phakic intraocular lens candidates: correlation between ocular biometric parameters.

PubMed

Ghoreishi, Mohammad; Abdi-Shahshahani, Mehdi; Peyman, Alireza; Pourazizi, Mohsen

2018-02-21

The aim of this study was to determine the correlation between ocular biometric parameters and sulcus-to-sulcus (STS) diameter. This was a cross-sectional study of preoperative ocular biometry data of patients who were candidates for phakic intraocular lens (IOL) surgery. Subjects underwent ocular biometry analysis, including refraction error evaluation using an autorefractor and Orbscan topography for white-to-white (WTW) corneal diameter and measurement. Pentacam was used to perform WTW corneal diameter and measurements of minimum and maximum keratometry (K). Measurements of STS and angle-to-angle (ATA) were obtained using a 50-MHz B-mode ultrasound device. Anterior optical coherence tomography was performed for anterior chamber depth measurement. Pearson's correlation test and stepwise linear regression analysis were used to find a model to predict STS. Fifty-eight eyes of 58 patients were enrolled. Mean age ± standard deviation of sample was 28.95 ± 6.04 years. The Pearson's correlation coefficient between STS with WTW, ATA, mean K was 0.383, 0.492, and - 0.353, respectively, which was statistically significant (all P < 0.001). Using stepwise linear regression analysis, there is a statistically significant association between STS with WTW (P = 0.011) and mean K (P = 0.025). The standardized coefficient was 0.323 and - 0.284 for WTW and mean K, respectively. The stepwise linear regression analysis equation was: (STS = 9.549 + 0.518 WTW - 0.083 mean K). Based on our result, given the correlation of STS with WTW and mean K and potential of direct and essay measurement of WTW and mean K, it seems that current IOL sizing protocols could be estimating with WTW and mean K.

Plasma endotoxin core antibody concentration and linear growth are unrelated in rural Malawian children aged 2-5 years.

PubMed

Benzoni, Nicole; Korpe, Poonum; Thakwalakwa, Chrissie; Maleta, Ken; Stephenson, Kevin; Manary, Micah; Manary, Mark

2015-06-24

Environmental enteropathy is subclinical inflammation of the upper gastrointestinal tract associated with reduced linear growth in developing countries. Usually investigators have used biopsy or a dual sugar absorption test to assess environmental enteropathy. Such tests are time and resource intensive, restricting their utility as screening methods. Serum endotoxin core antibody (EndoCab) concentration is a potential indicator of intestinal inflammation and integrity, and thus may be useful to predict environmental enteropathy. We analyzed the association of serum EndoCab levels versus linear growth and lactulose-mannitol assay results in 2-5 year old rural Malawian children. This was an observational study of 388 rural, asymptomatic Malawian children who had anthropometric measurements taken at least every 3 months since birth. In June and July 2011, dual sugar permeability tests were performed and serum samples were drawn for EndoCab assays. Pearson correlation, Student's t test and multivariable linear regression were used to compare ln EndoCab concentrations with height-for-age z scores (HAZ) at time of sampling and 3 months later. Identical analysis was also performed for ln EndoCab versus measurements from dual sugar permeability testing performed in conjunction with serum sampling. In a subgroup of children with anthropometric data in the months prior to serum sampling, Pearson correlation was used to estimate the relationship between ln EndoCab and recent linear growth. Ln EndoCab concentrations were not correlated with HAZ at time of measurement (B = -0.078, P = 0.14) nor change in HAZ over the subsequent 3 months HAZ (B = -0.018, P = 0.27). EndoCab concentration was not associated with %lactulose excretion (B < 0.001, P = 0.98) nor the lactulose:mannitol ratio (B = 0.021, P = 0.62). Subgroup analysis also did not reveal any significant association between EndoCab and recent growth. EndoCab titers were not correlated with measurements of growth or intestinal permeability in rural pre-school aged Malawian children.

Lumbar lordosis and sacral slope in lumbar spinal stenosis: standard values and measurement accuracy.

PubMed

Bredow, J; Oppermann, J; Scheyerer, M J; Gundlfinger, K; Neiss, W F; Budde, S; Floerkemeier, T; Eysel, P; Beyer, F

2015-05-01

Radiological study. To asses standard values, intra- and interobserver reliability and reproducibility of sacral slope (SS) and lumbar lordosis (LL) and the correlation of these parameters in patients with lumbar spinal stenosis (LSS). Anteroposterior and lateral X-rays of the lumbar spine of 102 patients with LSS were included in this retrospective, radiologic study. Measurements of SS and LL were carried out by five examiners. Intraobserver correlation and correlation between LL and SS were calculated with Pearson's r linear correlation coefficient and intraclass correlation coefficients (ICC) were calculated for inter- and intraobserver reliability. In addition, patients were examined in subgroups with respect to previous surgery and the current therapy. Lumbar lordosis averaged 45.6° (range 2.5°-74.9°; SD 14.2°), intraobserver correlation was between Pearson r = 0.93 and 0.98. The measurement of SS averaged 35.3° (range 13.8°-66.9°; SD 9.6°), intraobserver correlation was between Pearson r = 0.89 and 0.96. Intraobserver reliability ranged from 0.966 to 0.992 ICC in LL measurements and 0.944-0.983 ICC in SS measurements. There was an interobserver reliability ICC of 0.944 in LL and 0.990 in SS. Correlation between LL and SS averaged r = 0.79. No statistically significant differences were observed between the analyzed subgroups. Manual measurement of LL and SS in patients with LSS on lateral radiographs is easily performed with excellent intra- and interobserver reliability. Correlation between LL and SS is very high. Differences between patients with and without previous decompression were not statistically significant.

Prediction of Osteopathic Medical School Performance on the basis of MCAT score, GPA, sex, undergraduate major, and undergraduate institution.

PubMed

Dixon, Donna

2012-04-01

The relationships of students' preadmission academic variables, sex, undergraduate major, and undergraduate institution to academic performance in medical school have not been thoroughly examined. To determine the ability of students' preadmission academic variables to predict osteopathic medical school performance and whether students' sex, undergraduate major, or undergraduate institution influence osteopathic medical school performance. The study followed students who graduated from New York College of Osteopathic Medicine of New York Institute of Technology in Old Westbury between 2003 and 2006. Student preadmission data were Medical College Admission Test (MCAT) scores, undergraduate grade point averages (GPAs), sex, undergraduate major, and undergraduate institutional selectivity. Medical school performance variables were GPAs, clinical performance (ie, clinical subject examinations and clerkship evaluations), and scores on the Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) Level 1 and Level 2-Clinical Evaluation (CE). Data were analyzed with Pearson product moment correlation coefficients and multivariate linear regression analyses. Differences between student groups were compared with the independent-samples, 2-tailed t test. A total of 737 students were included. All preadmission academic variables, except nonscience undergraduate GPA, were statistically significant predictors of performance on COMLEX-USA Level 1, and all preadmission academic variables were statistically significant predictors of performance on COMLEX-USA Level 2-CE. The MCAT score for biological sciences had the highest correlation among all variables with COMLEX-USA Level 1 performance (Pearson r=0.304; P<.001) and Level 2-CE performance (Pearson r=0.272; P<.001). All preadmission variables were moderately correlated with the mean clinical subject examination scores. The mean clerkship evaluation score was moderately correlated with mean clinical examination results (Pearson r=0.267; P<.001) and COMLEX-USA Level 2-CE performance (Pearson r=0.301; P<.001). Clinical subject examination scores were highly correlated with COMLEX-USA Level 2-CE scores (Pearson r=0.817; P<.001). No statistically significant difference in medical school performance was found between students with science and nonscience undergraduate majors, nor was undergraduate institutional selectivity a factor influencing performance. Students' preadmission academic variables were predictive of osteopathic medical school performance, including GPAs, clinical performance, and COMLEX-USA Level 1 and Level 2-CE results. Clinical performance was predictive of COMLEX-USA Level 2-CE performance.

Emission and distribution of phosphine in paddy fields and its relationship with greenhouse gases.

PubMed

Chen, Weiyi; Niu, Xiaojun; An, Shaorong; Sheng, Hong; Tang, Zhenghua; Yang, Zhiquan; Gu, Xiaohong

2017-12-01

Phosphine (PH 3 ), as a gaseous phosphide, plays an important role in the phosphorus cycle in ecosystems. In this study, the emission and distribution of phosphine, carbon dioxide (CO 2 ) and methane (CH 4 ) in paddy fields were investigated to speculate the future potential impacts of enhanced greenhouse effect on phosphorus cycle involved in phosphine by the method of Pearson correlation analysis and multiple linear regression analysis. During the whole period of rice growth, there was a significant positive correlation between CO 2 emission flux and PH 3 emission flux (r=0.592, p=0.026, n=14). Similarly, a significant positive correlation of emission flux was also observed between CH 4 and PH 3 (r=0.563, p=0.036, n=14). The linear regression relationship was determined as [PH 3 ] flux =0.007[CO 2 ] flux +0.063[CH 4 ] flux -4.638. No significant differences were observed for all values of matrix-bound phosphine (MBP), soil carbon dioxide (SCO 2 ), and soil methane (SCH 4 ) in paddy soils. However, there was a significant positive correlation between MBP and SCO 2 at heading, flowering and ripening stage. The correlation coefficients were 0.909, 0.890 and 0.827, respectively. In vertical distribution, MBP had the analogical variation trend with SCO 2 and SCH 4 . Through Pearson correlation analysis and multiple stepwise linear regression analysis, pH, redox potential (Eh), total phosphorus (TP) and acid phosphatase (ACP) were identified as the principal factors affecting MBP levels, with correlative rankings of Eh>pH>TP>ACP. The multiple stepwise regression model ([MBP]=0.456∗[ACP]+0.235∗[TP]-1.458∗[Eh]-36.547∗[pH]+352.298) was obtained. The findings in this study hold great reference values to the global biogeochemical cycling of phosphorus in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Body Mass Index on Lung Function Index of Chinese Population

NASA Astrophysics Data System (ADS)

Guo, Qiao; Ye, Jun; Yang, Jian; Zhu, Changan; Sheng, Lei; Zhang, Yongliang

2018-01-01

To study the effect of body mass index (BMI) on lung function indexes in Chinese population. A cross-sectional study was performed on 10, 592 participants. The linear relationship between lung function and BMI was evaluated by multivariate linear regression analysis, and the correlation between BMI and lung function was assessed by Pearson correlation analysis. Correlation analysis showed that BMI was positively related with the decreasing of forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and FEV1/FVC (P <0.05), the increasing of FVC% predicted value (FVC%pre) and FEV1% predicted value (FEV1%pre). These suggested that Chinese people can restrain the decline of lung function to prevent the occurrence and development of COPD by the control of BMI.

Work related stress and blood glucose levels.

PubMed

Sancini, A; Ricci, S; Tomei, F; Sacco, C; Pacchiarotti, A; Nardone, N; Ricci, P; Suppi, A; De Cesare, D P; Anzelmo, V; Giubilati, R; Pimpinella, B; Rosati, M V; Tomei, G

2017-01-01

The aim of the study is to evaluate work-related subjective stress in a group of workers on a major Italian company in the field of healthcare through the administration of a valid "questionnaire-tool indicator" (HSE Indicator Tool), and to analyze any correlation between stress levels taken from questionnaire scores and blood glucose values. We studied a final sample consisting of 241 subjects with different tasks. The HSE questionnaire - made up of 35 items (divided into 7 organizational dimensions) with 5 possible answers - has been distributed to all the subjects in occasion of the health surveillance examinations provided by law. The questionnaire was then analyzed using its specific software to process the results related to the 7 dimensions. These results were compared using the Pearson correlation and multiple linear regression with the blood glucose values obtained from each subject. From the analysis of the data the following areas resulted critical, in other words linked to an intermediate (yellow area) or high (red area) condition of stress: sustain from managers, sustain from colleagues, quality of relationships and professional changes. A significant positive correlation (p <0.05) between the mean values of all critical areas and the concentrations of glucose values have been highlighted with the correlation index of Pearson. Multiple linear regression confirmed these findings, showing that the critical dimensions resulting from the questionnaire were the significant variables that can increase the levels of blood glucose. The preliminary results indicate that perceived work stress can be statistically associated with increased levels of blood glucose.

Development of a rapid, simple assay of plasma total carotenoids

PubMed Central

2012-01-01

Background Plasma total carotenoids can be used as an indicator of risk of chronic disease. Laboratory analysis of individual carotenoids by high performance liquid chromatography (HPLC) is time consuming, expensive, and not amenable to use beyond a research laboratory. The aim of this research is to establish a rapid, simple, and inexpensive spectrophotometric assay of plasma total carotenoids that has a very strong correlation with HPLC carotenoid profile analysis. Results Plasma total carotenoids from 29 volunteers ranged in concentration from 1.2 to 7.4 μM, as analyzed by HPLC. A linear correlation was found between the absorbance at 448 nm of an alcohol / heptane extract of the plasma and plasma total carotenoids analyzed by HPLC, with a Pearson correlation coefficient of 0.989. The average coefficient of variation for the spectrophotometric assay was 6.5% for the plasma samples. The limit of detection was about 0.3 μM and was linear up to about 34 μM without dilution. Correlations between the integrals of the absorption spectra in the range of carotenoid absorption and total plasma carotenoid concentration gave similar results to the absorbance correlation. Spectrophotometric assay results also agreed with the calculated expected absorbance based on published extinction coefficients for the individual carotenoids, with a Pearson correlation coefficient of 0.988. Conclusion The spectrophotometric assay of total carotenoids strongly correlated with HPLC analysis of carotenoids of the same plasma samples and expected absorbance values based on extinction coefficients. This rapid, simple, inexpensive assay, when coupled with the carotenoid health index, may be useful for nutrition intervention studies, population cohort studies, and public health interventions. PMID:23006902

Validation of questionnaire on the Spiritual Needs Assessment for Patients (SNAP) questionnaire in Brazilian Portuguese

PubMed Central

de Araujo Toloi, Diego; Uema, Deise; Matsushita, Felipe; da Silva Andrade, Paulo Antonio; Branco, Tiago Pugliese; de Carvalho Chino, Fabiana Tomie Becker; Guerra, Raquel Bezerra; Pfiffer, Túlio Eduardo Flesch; Chiba, Toshio; Guindalini, Rodrigo Santa Cruz; Sulmasy, Daniel P; Riechelmann, Rachel P

2016-01-01

Summary Objectives Spirituality is related to the care and the quality of life of cancer patients. Thus, it is very important to assess their needs. The objective of this study was the translation and cultural adjustment of the Spiritual Needs Assessment for Patients (SNAP) questionnaire to the Brazilian Portuguese language. Methodology The translation and cultural adjustment of the SNAP questionnaire involved six stages: backtranslation, revision of backtranslation, translation to the original language and adjustments, pre-test on ten patients, and test and retest with 30 patients after three weeks. Adult patients, with a solid tumour and literate with a minimum of four years schooling were included. For analysis and consistency we used the calculation of the Cronbach alpha coefficient and the Pearson linear correlation. Results The final questionnaire had some language and content adjustments compared to the original version in English. The correlation analysis of each item with the total score of the questionnaire showed coefficients above 0.99. The calculation of the Cronbach alpha coefficient was 0.9. The calculation of the Pearson linear correlation with the test and retest of the questionnaire was equal to 0.95. Conclusion The SNAP questionnaire translated into Brazilian Portuguese is adequately reliable and consistent. This instrument allows adequate access to spiritual needs and can help patient care. PMID:28101137

Deriving the Cost of Software Maintenance for Software Intensive Systems

DTIC Science & Technology

2011-08-29

more of software maintenance). Figure 4. SEER-SEM Maintenance Effort by Year Report (Reifer, Allen, Fersch, Hitchings, Judy , & Rosa, 2010...understand the linear relationship between two variables. The formula for the simple Pearson product-moment correlation is represented in Equation 5...standardization is required across the software maintenance community in order to ensure that the data being recorded can be employed beyond the agency or

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

Surface topography, nano-mechanics and secondary structure of wheat gluten pretreated by alternate dual-frequency ultrasound and the correlation to enzymolysis.

PubMed

Zhang, Yanyan; Wang, Bei; Zhou, Cunshan; Atungulu, Griffiths G; Xu, Kangkang; Ma, Haile; Ye, Xiaofei; Abdualrahman, Mohammed A Y

2016-07-01

The effects of alternate dual-frequency ultrasound (ADFU) pretreatment on the degree of hydrolysis (DH) of wheat gluten (WG) and angiotensin I-converting enzyme (ACE) inhibitory activity were investigated in this research. The surface topography, nano-mechanics and secondary structure of WG were also determined using atomic force microscope (AFM) and circular dichroism (CD). The correlations of ACE inhibitory activity and DH with surface topography, nano-mechanics and secondary structure of WG were determined using Pearson's correlation analysis. The results showed that with an increase in either pretreatment duration or power, the ACE inhibitory activity of the hydrolysate also increases, reaching maximum at 10 min and 150 W/L, respectively, and then decreases thereafter. Similarly, AFM analysis showed that as the pretreatment duration or power increases, the surface roughness also increase and again a decrease occurs thereafter. As the pretreatment duration or power increased, the Young's modulus and adhesion of WG also increased and then declined. Young's modulus and adhesions average values were compared with ACE inhibitory activity reversely. The result of the CD spectra analysis exhibited losses in the relative percentage of α-helix of WG. Pearson's correlation analysis showed that the average values of Young's modulus and the relative percentage of α-helix correlated with ACE inhibitory activity of the hydrolysates linearly and significantly (P<0.05); the relative percentage of β-sheet correlated linearly with DH of WG significantly (P<0.05). In conclusion, ADFU pretreatment is an efficient method in proteolysis due to its physical and chemical effect on the Young's modulus, α-helix and β-sheet of WG. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of Spectral Characteristic between LAPAN-A3 and Sentinel-2A

NASA Astrophysics Data System (ADS)

Zylshal, Z.; Sari, N. M.; Nugroho, J. T.; Kushardono, D.

2017-12-01

Indonesian National Institute of Aeronautics and Space (LAPAN) started building its experimental microsatellite back in 2007 and finally able to launch its first microsatellite dubbed as LAPAN-A1/LAPAN-Tubsat. With the launch of LAPAN-A3/LAPAN-IPB, Indonesian experimental satellite programme hit its third generation. LAPAN-A3 is carrying multiple payloads including multispectral push-broom imager, digital matrix camera, as well as video camera. This paper aims to highlight the spectral differences between LAPAN-A3 and the well-established Sentinel-2A multispectral to investigate the potential of using LAPAN-A3 data to complement the other well-established medium resolution satellite data. Comparisons between corresponding bands and band transformations were performed over a dataset. Three areas of interest were chosen as the test sites. Linear regression and Pearson correlation coefficient were then calculated between the corresponding bands. The preliminary results showed a moderate correlation between the two sensors with Pearson correlation coefficient ranging from 0.39 to 0.65. Some issues were found regarding the radiometric quality over the whole scene of LAPAN-A3.

Relationship Between Ktrans and K1 with Simultaneous Versus Separate MR/PET in Rabbits with VX2 Tumors.

PubMed

Lee, Kyung Hee; Kang, Seung Kwan; Goo, Jin Mo; Lee, Jae Sung; Cheon, Gi Jeong; Seo, Seongho; Hwang, Eui Jin

2017-03-01

To compare the relationship between K trans from DCE-MRI and K 1 from dynamic 13 N-NH 3 -PET, with simultaneous and separate MR/PET in the VX-2 rabbit carcinoma model. MR/PET was performed simultaneously and separately, 14 and 15 days after VX-2 tumor implantation at the paravertebral muscle. The K trans and K 1 values were estimated using an in-house software program. The relationships between K trans and K 1 were analyzed using Pearson's correlation coefficients and linear/non-linear regression function. Assuming a linear relationship, K trans and K 1 exhibited a moderate positive correlations with both simultaneous (r=0.54-0.57) and separate (r=0.53-0.69) imaging. However, while the K trans and K 1 from separate imaging were linearly correlated, those from simultaneous imaging exhibited a non-linear relationship. The amount of change in K 1 associated with a unit increase in K trans varied depending on K trans values. The relationship between K trans and K 1 may be mis-interpreted with separate MR and PET acquisition. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Cerebral Glucose Metabolism and Sedation in Brain-injured Patients: A Microdialysis Study.

PubMed

Hertle, Daniel N; Santos, Edgar; Hagenston, Anna M; Jungk, Christine; Haux, Daniel; Unterberg, Andreas W; Sakowitz, Oliver W

2015-07-01

Disturbed brain metabolism is a signature of primary damage and/or precipitates secondary injury processes after severe brain injury. Sedatives and analgesics target electrophysiological functioning and are as such well-known modulators of brain energy metabolism. Still unclear, however, is how sedatives impact glucose metabolism and whether they differentially influence brain metabolism in normally active, healthy brain and critically impaired, injured brain. We therefore examined and compared the effects of anesthetic drugs under both critical (<1 mmol/L) and noncritical (>1 mmol/L) extracellular brain glucose levels. We performed an explorative, retrospective analysis of anesthetic drug administration and brain glucose concentrations, obtained by bedside microdialysis, in 19 brain-injured patients. Our investigations revealed an inverse linear correlation between brain glucose and both the concentration of extracellular glutamate (Pearson r=-0.58, P=0.01) and the lactate/glucose ratio (Pearson r=-0.55, P=0.01). For noncritical brain glucose levels, we observed a positive linear correlation between midazolam dose and brain glucose (P<0.05). For critical brain glucose levels, extracellular brain glucose was unaffected by any type of sedative. These findings suggest that the use of anesthetic drugs may be of limited value in attempts to influence brain glucose metabolism in injured brain tissue.

Correlation and agreement: overview and clarification of competing concepts and measures.

PubMed

Liu, Jinyuan; Tang, Wan; Chen, Guanqin; Lu, Yin; Feng, Changyong; Tu, Xin M

2016-04-25

Agreement and correlation are widely-used concepts that assess the association between variables. Although similar and related, they represent completely different notions of association. Assessing agreement between variables assumes that the variables measure the same construct, while correlation of variables can be assessed for variables that measure completely different constructs. This conceptual difference requires the use of different statistical methods, and when assessing agreement or correlation, the statistical method may vary depending on the distribution of the data and the interest of the investigator. For example, the Pearson correlation, a popular measure of correlation between continuous variables, is only informative when applied to variables that have linear relationships; it may be non-informative or even misleading when applied to variables that are not linearly related. Likewise, the intraclass correlation, a popular measure of agreement between continuous variables, may not provide sufficient information for investigators if the nature of poor agreement is of interest. This report reviews the concepts of agreement and correlation and discusses differences in the application of several commonly used measures.

Impact of Article Language in Multi-Language Medical Journals - a Bibliometric Analysis of Self-Citations and Impact Factor

PubMed Central

Diekhoff, Torsten; Schlattmann, Peter; Dewey, Marc

2013-01-01

Background In times of globalization there is an increasing use of English in the medical literature. The aim of this study was to analyze the influence of English-language articles in multi-language medical journals on their international recognition – as measured by a lower rate of self-citations and higher impact factor (IF). Methods and Findings We analyzed publications in multi-language journals in 2008 and 2009 using the Web of Science (WoS) of Thomson Reuters (former Institute of Scientific Information) and PubMed as sources of information. The proportion of English-language articles during the period was compared with both the share of self-citations in the year 2010 and the IF with and without self-citations. Multivariable linear regression analysis was performed to analyze these factors as well as the influence of the journals‘ countries of origin and of the other language(s) used in publications besides English. We identified 168 multi-language journals that were listed in WoS as well as in PubMed and met our criteria. We found a significant positive correlation of the share of English articles in 2008 and 2009 with the IF calculated without self-citations (Pearson r=0.56, p = <0.0001), a correlation with the overall IF (Pearson r = 0.47, p = <0.0001) and with the cites to years of IF calculation (Pearson r = 0.34, p = <0.0001), and a weak negative correlation with the share of self-citations (Pearson r = -0.2, p = 0.009). The IF without self-citations also correlated with the journal‘s country of origin – North American journals had a higher IF compared to Middle and South American or European journals. Conclusion Our findings suggest that a larger share of English articles in multi-language medical journals is associated with greater international recognition. Fewer self-citations were found in multi-language journals with a greater share of original articles in English. PMID:24146929

A comparison of high-frequency cross-correlation measures

NASA Astrophysics Data System (ADS)

Precup, Ovidiu V.; Iori, Giulia

2004-12-01

On a high-frequency scale the time series are not homogeneous, therefore standard correlation measures cannot be directly applied to the raw data. There are two ways to deal with this problem. The time series can be homogenised through an interpolation method (An Introduction to High-Frequency Finance, Academic Press, NY, 2001) (linear or previous tick) and then the Pearson correlation statistic computed. Recently, methods that can handle raw non-synchronous time series have been developed (Int. J. Theor. Appl. Finance 6(1) (2003) 87; J. Empirical Finance 4 (1997) 259). This paper compares two traditional methods that use interpolation with an alternative method applied directly to the actual time series.

Correlation of Vitamin D status and orthodontic-induced external apical root resorption.

PubMed

Tehranchi, Azita; Sadighnia, Azin; Younessian, Farnaz; Abdi, Amir H; Shirvani, Armin

2017-01-01

Adequate Vitamin D is essential for dental and skeletal health in children and adult. The purpose of this study was to assess the correlation of serum Vitamin D level with external-induced apical root resorption (EARR) following fixed orthodontic treatment. In this cross-sectional study, the prevalence of Vitamin D deficiency (defined by25-hydroxyvitamin-D) was determined in 34 patients (23.5% male; age range 12-23 years; mean age 16.63 ± 2.84) treated with fixed orthodontic treatment. Root resorption of four maxillary incisors was measured using before and after periapical radiographs (136 measured teeth) by means of a design-to-purpose software to optimize data collection. Teeth with a maximum percentage of root resorption (%EARR) were indicated as representative root resorption for each patient. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of Vitamin D status and observed EARR. P < 0.05 was considered statistically significant. The Pearson coefficient between these two variables was determined about 0.15 ( P = 0.38). Regression analysis revealed that Vitamin D status of the patients demonstrated no significant statistical correlation with EARR, after adjustment of confounding variables using linear regression model ( P > 0.05). This study suggests that Vitamin D level is not among the clinical variables that are potential contributors for EARR. The prevalence of Vitamin D deficiency does not differ in patients with higher EARR. These data suggest the possibility that Vitamin D insufficiency may not contribute to the development of more apical root resorption although this remains to be confirmed by further longitudinal cohort studies.

Measuring monotony in two-dimensional samples

NASA Astrophysics Data System (ADS)

Kachapova, Farida; Kachapov, Ilias

2010-04-01

This note introduces a monotony coefficient as a new measure of the monotone dependence in a two-dimensional sample. Some properties of this measure are derived. In particular, it is shown that the absolute value of the monotony coefficient for a two-dimensional sample is between |r| and 1, where r is the Pearson's correlation coefficient for the sample; that the monotony coefficient equals 1 for any monotone increasing sample and equals -1 for any monotone decreasing sample. This article contains a few examples demonstrating that the monotony coefficient is a more accurate measure of the degree of monotone dependence for a non-linear relationship than the Pearson's, Spearman's and Kendall's correlation coefficients. The monotony coefficient is a tool that can be applied to samples in order to find dependencies between random variables; it is especially useful in finding couples of dependent variables in a big dataset of many variables. Undergraduate students in mathematics and science would benefit from learning and applying this measure of monotone dependence.

Information-theoretic approach to lead-lag effect on financial markets

NASA Astrophysics Data System (ADS)

Fiedor, Paweł

2014-08-01

Recently the interest of researchers has shifted from the analysis of synchronous relationships of financial instruments to the analysis of more meaningful asynchronous relationships. Both types of analysis are concentrated mostly on Pearson's correlation coefficient and consequently intraday lead-lag relationships (where one of the variables in a pair is time-lagged) are also associated with them. Under the Efficient-Market Hypothesis such relationships are not possible as all information is embedded in the prices, but in real markets we find such dependencies. In this paper we analyse lead-lag relationships of financial instruments and extend known methodology by using mutual information instead of Pearson's correlation coefficient. Mutual information is not only a more general measure, sensitive to non-linear dependencies, but also can lead to a simpler procedure of statistical validation of links between financial instruments. We analyse lagged relationships using New York Stock Exchange 100 data not only on an intraday level, but also for daily stock returns, which have usually been ignored.

Objective evaluation of muscle strength in infants with hypotonia and muscle weakness.

PubMed

Reus, Linda; van Vlimmeren, Leo A; Staal, J Bart; Janssen, Anjo J W M; Otten, Barto J; Pelzer, Ben J; Nijhuis-van der Sanden, Maria W G

2013-04-01

The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81 typically developing infants, 6-36 months of age, and 17 infants with Prader-Willi Syndrome (PWS) aged 24 months. The inter-rater reliability of the measurement method was good (ICC=.84) and the convergent validity was confirmed by high Pearson's correlations between muscle strength, age, height, and weight (r=.79-.85). A multiple linear regression model was developed to predict muscle strength based on age, height, and weight, explaining 73% of the variance in muscle strength. In infants with PWS, muscle strength was significantly decreased. Pearson's correlations showed that infants with PWS in which muscle strength was more severely affected also had a larger motor developmental delay (r=.75). Copyright © 2013 Elsevier Ltd. All rights reserved.

Dynamic Time Warping compared to established methods for validation of musculoskeletal models.

PubMed

Gaspar, Martin; Welke, Bastian; Seehaus, Frank; Hurschler, Christof; Schwarze, Michael

2017-04-11

By means of Multi-Body musculoskeletal simulation, important variables such as internal joint forces and moments can be estimated which cannot be measured directly. Validation can ensued by qualitative or by quantitative methods. Especially when comparing time-dependent signals, many methods do not perform well and validation is often limited to qualitative approaches. The aim of the present study was to investigate the capabilities of the Dynamic Time Warping (DTW) algorithm for comparing time series, which can quantify phase as well as amplitude errors. We contrast the sensitivity of DTW with other established metrics: the Pearson correlation coefficient, cross-correlation, the metric according to Geers, RMSE and normalized RMSE. This study is based on two data sets, where one data set represents direct validation and the other represents indirect validation. Direct validation was performed in the context of clinical gait-analysis on trans-femoral amputees fitted with a 6 component force-moment sensor. Measured forces and moments from amputees' socket-prosthesis are compared to simulated forces and moments. Indirect validation was performed in the context of surface EMG measurements on a cohort of healthy subjects with measurements taken of seven muscles of the leg, which were compared to simulated muscle activations. Regarding direct validation, a positive linear relation between results of RMSE and nRMSE to DTW can be seen. For indirect validation, a negative linear relation exists between Pearson correlation and cross-correlation. We propose the DTW algorithm for use in both direct and indirect quantitative validation as it correlates well with methods that are most suitable for one of the tasks. However, in DV it should be used together with methods resulting in a dimensional error value, in order to be able to interpret results more comprehensible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Partial Correlation-Based Retinotopically Organized Resting-State Functional Connectivity Within and Between Areas of the Visual Cortex Reflects More Than Cortical Distance

PubMed Central

Dawson, Debra Ann; Lam, Jack; Lewis, Lindsay B.; Carbonell, Felix; Mendola, Janine D.

2016-01-01

Abstract Numerous studies have demonstrated functional magnetic resonance imaging (fMRI)-based resting-state functional connectivity (RSFC) between cortical areas. Recent evidence suggests that synchronous fluctuations in blood oxygenation level-dependent fMRI reflect functional organization at a scale finer than that of visual areas. In this study, we investigated whether RSFCs within and between lower visual areas are retinotopically organized and whether retinotopically organized RSFC merely reflects cortical distance. Subjects underwent retinotopic mapping and separately resting-state fMRI. Visual areas V1, V2, and V3, were subdivided into regions of interest (ROIs) according to quadrants and visual field eccentricity. Functional connectivity (FC) was computed based on Pearson's linear correlation (correlation), and Pearson's linear partial correlation (correlation between two time courses after the time courses from all other regions in the network are regressed out). Within a quadrant, within visual areas, all correlation and nearly all partial correlation FC measures showed statistical significance. Consistently in V1, V2, and to a lesser extent in V3, correlation decreased with increasing eccentricity separation. Consistent with previously reported monkey anatomical connectivity, correlation/partial correlation values between regions from adjacent areas (V1-V2 and V2-V3) were higher than those between nonadjacent areas (V1-V3). Within a quadrant, partial correlation showed consistent significance between regions from two different areas with the same or adjacent eccentricities. Pairs of ROIs with similar eccentricity showed higher correlation/partial correlation than pairs distant in eccentricity. Between dorsal and ventral quadrants, partial correlation between common and adjacent eccentricity regions within a visual area showed statistical significance; this extended to more distant eccentricity regions in V1. Within and between quadrants, correlation decreased approximately linearly with increasing distances separating the tested ROIs. Partial correlation showed a more complex dependence on cortical distance: it decreased exponentially with increasing distance within a quadrant, but was best fit by a quadratic function between quadrants. We conclude that RSFCs within and between lower visual areas are retinotopically organized. Correlation-based FC is nonselectively high across lower visual areas, even between regions that do not share direct anatomical connections. The mechanisms likely involve network effects caused by the dense anatomical connectivity within this network and projections from higher visual areas. FC based on partial correlation, which minimizes network effects, follows expectations based on direct anatomical connections in the monkey visual cortex better than correlation. Last, partial correlation-based retinotopically organized RSFC reflects more than cortical distance effects. PMID:26415043

Partial Correlation-Based Retinotopically Organized Resting-State Functional Connectivity Within and Between Areas of the Visual Cortex Reflects More Than Cortical Distance.

PubMed

Dawson, Debra Ann; Lam, Jack; Lewis, Lindsay B; Carbonell, Felix; Mendola, Janine D; Shmuel, Amir

2016-02-01

Numerous studies have demonstrated functional magnetic resonance imaging (fMRI)-based resting-state functional connectivity (RSFC) between cortical areas. Recent evidence suggests that synchronous fluctuations in blood oxygenation level-dependent fMRI reflect functional organization at a scale finer than that of visual areas. In this study, we investigated whether RSFCs within and between lower visual areas are retinotopically organized and whether retinotopically organized RSFC merely reflects cortical distance. Subjects underwent retinotopic mapping and separately resting-state fMRI. Visual areas V1, V2, and V3, were subdivided into regions of interest (ROIs) according to quadrants and visual field eccentricity. Functional connectivity (FC) was computed based on Pearson's linear correlation (correlation), and Pearson's linear partial correlation (correlation between two time courses after the time courses from all other regions in the network are regressed out). Within a quadrant, within visual areas, all correlation and nearly all partial correlation FC measures showed statistical significance. Consistently in V1, V2, and to a lesser extent in V3, correlation decreased with increasing eccentricity separation. Consistent with previously reported monkey anatomical connectivity, correlation/partial correlation values between regions from adjacent areas (V1-V2 and V2-V3) were higher than those between nonadjacent areas (V1-V3). Within a quadrant, partial correlation showed consistent significance between regions from two different areas with the same or adjacent eccentricities. Pairs of ROIs with similar eccentricity showed higher correlation/partial correlation than pairs distant in eccentricity. Between dorsal and ventral quadrants, partial correlation between common and adjacent eccentricity regions within a visual area showed statistical significance; this extended to more distant eccentricity regions in V1. Within and between quadrants, correlation decreased approximately linearly with increasing distances separating the tested ROIs. Partial correlation showed a more complex dependence on cortical distance: it decreased exponentially with increasing distance within a quadrant, but was best fit by a quadratic function between quadrants. We conclude that RSFCs within and between lower visual areas are retinotopically organized. Correlation-based FC is nonselectively high across lower visual areas, even between regions that do not share direct anatomical connections. The mechanisms likely involve network effects caused by the dense anatomical connectivity within this network and projections from higher visual areas. FC based on partial correlation, which minimizes network effects, follows expectations based on direct anatomical connections in the monkey visual cortex better than correlation. Last, partial correlation-based retinotopically organized RSFC reflects more than cortical distance effects.

Clinical Relevance of Alternative Endpoints in Colorectal Cancer First-Line Therapy With Bevacizumab: A Retrospective Study.

PubMed

Turpin, Anthony; Paget-Bailly, Sophie; Ploquin, Anne; Hollebecque, Antoine; Peugniez, Charlotte; El-Hajbi, Farid; Bonnetain, Franck; Hebbar, Mohamed

2018-03-01

We studied the relationship between intermediate criteria and overall survival (OS) in metastatic colorectal cancer (mCRC) patients who received first-line chemotherapy with bevacizumab. We assessed OS, progression-free survival (PFS), duration of disease control (DDC), the sum of the periods in which the disease did not progress, and the time to failure of strategy (TFS), which was defined as the entire period before the introduction of a second-line treatment. Linear correlation and regression models were used, and Prentice criteria were investigated. With a median follow-up of 57.6 months for 216 patients, the median OS was 24.5 months (95% confidence interval [CI], 21.3-29.7). The median PFS, DDC, and TFS were 8.9 (95% CI, 8.4-9.7), 11.0 (95% CI, 9.8-12.4), and 11.1 (95% CI, 10.0-13.0) months, respectively. The correlations between OS and DDC (Pearson coefficient, 0.79 [95% CI, 0.73-0.83], determination coefficient, 0.62) and OS and TFS (Pearson coefficient, 0.79 [95% CI, 0.73-0.84], determination coefficient, 0.63) were satisfactory. Linear regression analysis showed a significant association between OS and DDC, and between OS and TFS. Prentice criteria were verified for TFS as well as DDC. DDC and TFS correlated with OS and are relevant as intermediate criteria in the setting of patients with mCRC treated with a first-line bevacizumab-based regimen. Copyright © 2017 Elsevier Inc. All rights reserved.

Time-resolved perfusion imaging at the angiography suite: preclinical comparison of a new flat-detector application to computed tomography perfusion.

PubMed

Jürgens, Julian H W; Schulz, Nadine; Wybranski, Christian; Seidensticker, Max; Streit, Sebastian; Brauner, Jan; Wohlgemuth, Walter A; Deuerling-Zheng, Yu; Ricke, Jens; Dudeck, Oliver

2015-02-01

The objective of this study was to compare the parameter maps of a new flat-panel detector application for time-resolved perfusion imaging in the angiography room (FD-CTP) with computed tomography perfusion (CTP) in an experimental tumor model. Twenty-four VX2 tumors were implanted into the hind legs of 12 rabbits. Three weeks later, FD-CTP (Artis zeego; Siemens) and CTP (SOMATOM Definition AS +; Siemens) were performed. The parameter maps for the FD-CTP were calculated using a prototype software, and those for the CTP were calculated with VPCT-body software on a dedicated syngo MultiModality Workplace. The parameters were compared using Pearson product-moment correlation coefficient and linear regression analysis. The Pearson product-moment correlation coefficient showed good correlation values for both the intratumoral blood volume of 0.848 (P < 0.01) and the blood flow of 0.698 (P < 0.01). The linear regression analysis of the perfusion between FD-CTP and CTP showed for the blood volume a regression equation y = 4.44x + 36.72 (P < 0.01) and for the blood flow y = 0.75x + 14.61 (P < 0.01). This preclinical study provides evidence that FD-CTP allows a time-resolved (dynamic) perfusion imaging of tumors similar to CTP, which provides the basis for clinical applications such as the assessment of tumor response to locoregional therapies directly in the angiography suite.

Pulmonary Catherization Data Correlate Poorly with Renal Function in Heart Failure.

PubMed

Masha, Luke; Stone, James; Stone, Danielle; Zhang, Jun; Sheng, Luo

2018-04-10

The mechanisms of renal dysfunction in heart failure are poorly understood. We chose to explore the relationship of cardiac filling pressures and cardiac index (CI) in relation to renal dysfunction in advanced heart failure. To determine the relationship between renal function and cardiac filling pressures using the United Network of Organ Sharing (UNOS) pulmonary artery catherization registry. Patients over the age of 18 years who were listed for single-organ heart transplantation were included. Exclusion criteria included a history of mechanical circulatory support, previous transplantation, any use of renal replacement therapy, prior history of malignancy, and cardiac surgery, amongst others. Correlations between serum creatinine (SCr) and CI, pulmonary capillary wedge pressure (PCWP), pulmonary artery systolic pressure (PASP), and pulmonary artery diastolic pressure (PADP) were assessed by Pearson correlation coefficients and simple linear regression coefficients. Pearson correlation coefficients between SCr and PCWP, PASP, and PADP were near zero with values of 0.1, 0.07, and 0.08, respectively (p < 0.0001). A weak negative correlation coefficient between SCr and CI was found (correlation coefficient, -0.045, p = 0.027). In a subgroup of young patients unlikely to have noncardiac etiologies, no significant correlations between these values were identified. These findings suggest that, as assessed by pulmonary artery catherization, none of the factors - PCWP, PASP, PADP, or CI - play a prominent role in cardiorenal syndromes. © 2018 S. Karger AG, Basel.

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 cephalometric analysis of Class II dentate subjects to establish a formula to determine the occlusal plane in Class II edentate subjects: A neo adjunct.

PubMed

Sinha, Nikita; Reddy, K Mahendranadh; Gupta, Nidhi; Shastry, Y M

2017-01-01

Occlusal plane (OP) differs considerably in participants with skeletal Class I and Class II participants. In this study, cephalometrics has been used to help in the determination of orientation of the OP utilizing the nonresorbable bony anatomic landmarks in skeletal Class II participants and an attempt has been made to predict and examine the OP in individuals with skeletal class II jaw relationship. One hundred dentulous participants with skeletal Class II malocclusion who came to the hospital for correcting their jaw relationship participated in the study. Their right lateral cephalogram was taken using standardized procedures, and all the tracings were manually done by a single trained examiner. The cephalograms which were taken for the diagnostic purpose were utilized for the study, and the patient was not exposed to any unnecessary radiation. The numerical values obtained from the cephalograms were subjected to statistical analysis. Pearson's correlation of <0.001 was considered significant, and a linear regression analysis was performed to determine a formula which would help in the determination of orientation of the OP in Class II edentulous participants. Pearson's correlation coefficient and linear regression analysis were performed, and a high correlation was found between A2 and (A2 + B2)/(B2 + C2) with " r " value of 0.5. A medium correlation was found between D2 and (D2 + E2)/(E2 + F2) with " r " value of 0.42. The formula obtained for posterior reference frame through linear regression equation was y = 0.018* × +0.459 and the formula obtained for anterior reference frame was y1 = 0.011* × 1 + 0.497. It was hypothesized that by substituting these formulae in the cephalogram obtained from the Class II edentate individual, the OP can be obtained and verified. It was concluded that cephalometrics can be useful in examining the orientation of OP in skeletal Class II participants.

Correlation Structure of Fractional Pearson Diffusions.

PubMed

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

2013-09-01

The stochastic solution to a diffusion equations with polynomial coefficients is called a Pearson diffusion. If the first time derivative is replaced by a Caputo fractional derivative of order less than one, the stochastic solution is called a fractional Pearson diffusion. This paper develops an explicit formula for the covariance function of a fractional Pearson diffusion in steady state, in terms of Mittag-Leffler functions. That formula shows that fractional Pearson diffusions are long range dependent, with a correlation that falls off like a power law, whose exponent equals the order of the fractional derivative.

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 differences in pigment levels, however, make it possible to differentiate species remotely.

Computer aided diagnosis system for Alzheimer disease using brain diffusion tensor imaging features selected by Pearson's correlation.

PubMed

Graña, M; Termenon, M; Savio, A; Gonzalez-Pinto, A; Echeveste, J; Pérez, J M; Besga, A

2011-09-20

The aim of this paper is to obtain discriminant features from two scalar measures of Diffusion Tensor Imaging (DTI) data, Fractional Anisotropy (FA) and Mean Diffusivity (MD), and to train and test classifiers able to discriminate Alzheimer's Disease (AD) patients from controls on the basis of features extracted from the FA or MD volumes. In this study, support vector machine (SVM) classifier was trained and tested on FA and MD data. Feature selection is done computing the Pearson's correlation between FA or MD values at voxel site across subjects and the indicative variable specifying the subject class. Voxel sites with high absolute correlation are selected for feature extraction. Results are obtained over an on-going study in Hospital de Santiago Apostol collecting anatomical T1-weighted MRI volumes and DTI data from healthy control subjects and AD patients. FA features and a linear SVM classifier achieve perfect accuracy, sensitivity and specificity in several cross-validation studies, supporting the usefulness of DTI-derived features as an image-marker for AD and to the feasibility of building Computer Aided Diagnosis systems for AD based on them. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Multidisciplinary Biomarkers of Early Mammary Carcinogenesis

DTIC Science & Technology

2011-04-01

cDNA prepared. Quantitative real-time PCR (qRT-PCR) was then performed on the cDNA. All qRT-PCR reactions were performed in triplicate. ESR1 ...in Figure 4, all ER(+) cells express ESR1 at high levels (at least 4 fold higher than ER(-) cell lines). A Pearson correlation coefficient was...calculated to determine the linear relationship between the optical redox ratio and ESR1 expression levels and found to be significant (p = 0.0024, r

Relationship between Air Traffic Selection and Training (AT-SAT)) Battery Test Scores and Composite Scores in the Initial en Route Air Traffic Control Qualification Training Course at the Federal Aviation Administration (FAA) Academy

ERIC Educational Resources Information Center

Kelley, Ronald Scott

2012-01-01

Scope and Method of Study: This study focused on the development and use of the AT-SAT test battery and the Initial En Route Qualification training course for the selection, training, and evaluation of air traffic controller candidates. The Pearson product moment correlation coefficient was used to measure the linear relationship between the…

Relation between histological prostatitis and lower urinary tract symptoms and erectile function.

PubMed

Mizuno, Taiki; Hiramatsu, Ippei; Aoki, Yusuke; Shimoyama, Hirofumi; Nozaki, Taiji; Shirai, Masato; Lu, Yan; Horie, Shigeo; Tsujimura, Akira

2017-09-01

Chronic prostatitis (CP) significantly worsens a patient's quality of life (QOL), but its etiology is heterogeneous. Although the inflammatory process must be associated with CP symptoms, not all patients with benign prostatic hyperplasia and histological prostatitis complain of CP symptoms. The relation between the severity of histological inflammation and lower urinary tract symptoms (LUTS) and erectile function is not fully understood. This study comprised 26 men with suspected prostate cancer but with no malignant lesion by pathological examination of prostate biopsy specimens. LUTS were assessed by several questionnaires including the International Prostate Symptom Score (IPSS), QOL index, Overactive Bladder Symptom Score (OABSS), and the National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI), and erectile function was assessed by the Sexual Health Inventory for Men. Prostate volume (PV) measured by transabdominal ultrasound, maximum flow rate by uroflowmetry, and serum concentration of prostate-specific antigen were also evaluated. All data collections were performed before prostate biopsy. Histological prostatitis was assessed by immunohistochemical staining with anti-CD45 antibody as the Quick score. The relation between the Quick score and several factors was assessed by Pearson correlation coefficient and a multivariate linear regression model after adjustment for PV. The Pearson correlation coefficient showed a correlation between the Quick score and several factors including PV, IPSS, QOL index, OABSS, and NIH-CPSI. A multivariate linear regression model after adjustment for PV showed only the NIH-CPSI to be associated with the Quick score. The relation between the Quick score and each domain score of the NIH-CPSI showed only the subscore of urinary symptoms to be an associated factor. We found a correlation only between histological prostatitis and LUTS, but not erectile dysfunction. Especially, the subscore of urinary symptoms (residual feeling and urinary frequency) was associated with histological prostatitis.

Distributed lags time series analysis versus linear correlation analysis (Pearson's r) in identifying the relationship between antipseudomonal antibiotic consumption and the susceptibility of Pseudomonas aeruginosa isolates in a single Intensive Care Unit of a tertiary hospital.

PubMed

Erdeljić, Viktorija; Francetić, Igor; Bošnjak, Zrinka; Budimir, Ana; Kalenić, Smilja; Bielen, Luka; Makar-Aušperger, Ksenija; Likić, Robert

2011-05-01

The relationship between antibiotic consumption and selection of resistant strains has been studied mainly by employing conventional statistical methods. A time delay in effect must be anticipated and this has rarely been taken into account in previous studies. Therefore, distributed lags time series analysis and simple linear correlation were compared in their ability to evaluate this relationship. Data on monthly antibiotic consumption for ciprofloxacin, piperacillin/tazobactam, carbapenems and cefepime as well as Pseudomonas aeruginosa susceptibility were retrospectively collected for the period April 2006 to July 2007. Using distributed lags analysis, a significant temporal relationship was identified between ciprofloxacin, meropenem and cefepime consumption and the resistance rates of P. aeruginosa isolates to these antibiotics. This effect was lagged for ciprofloxacin and cefepime [1 month (R=0.827, P=0.039) and 2 months (R=0.962, P=0.001), respectively] and was simultaneous for meropenem (lag 0, R=0.876, P=0.002). Furthermore, a significant concomitant effect of meropenem consumption on the appearance of multidrug-resistant P. aeruginosa strains (resistant to three or more representatives of classes of antibiotics) was identified (lag 0, R=0.992, P<0.001). This effect was not delayed and it was therefore identified both by distributed lags analysis and the Pearson's correlation coefficient. Correlation coefficient analysis was not able to identify relationships between antibiotic consumption and bacterial resistance when the effect was delayed. These results indicate that the use of diverse statistical methods can yield significantly different results, thus leading to the introduction of possibly inappropriate infection control measures. Copyright © 2010 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Correlation of Vitamin D status and orthodontic-induced external apical root resorption

PubMed Central

Tehranchi, Azita; Sadighnia, Azin; Younessian, Farnaz; Abdi, Amir H.; Shirvani, Armin

2017-01-01

Background: Adequate Vitamin D is essential for dental and skeletal health in children and adult. The purpose of this study was to assess the correlation of serum Vitamin D level with external-induced apical root resorption (EARR) following fixed orthodontic treatment. Materials and Methods: In this cross-sectional study, the prevalence of Vitamin D deficiency (defined by25-hydroxyvitamin-D) was determined in 34 patients (23.5% male; age range 12–23 years; mean age 16.63 ± 2.84) treated with fixed orthodontic treatment. Root resorption of four maxillary incisors was measured using before and after periapical radiographs (136 measured teeth) by means of a design-to-purpose software to optimize data collection. Teeth with a maximum percentage of root resorption (%EARR) were indicated as representative root resorption for each patient. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of Vitamin D status and observed EARR. P < 0.05 was considered statistically significant. Results: The Pearson coefficient between these two variables was determined about 0.15 (P = 0.38). Regression analysis revealed that Vitamin D status of the patients demonstrated no significant statistical correlation with EARR, after adjustment of confounding variables using linear regression model (P > 0.05). Conclusion: This study suggests that Vitamin D level is not among the clinical variables that are potential contributors for EARR. The prevalence of Vitamin D deficiency does not differ in patients with higher EARR. These data suggest the possibility that Vitamin D insufficiency may not contribute to the development of more apical root resorption although this remains to be confirmed by further longitudinal cohort studies. PMID:29238379

Zero Pearson coefficient for strongly correlated growing trees.

PubMed

Dorogovtsev, S N; Ferreira, A L; Goltsev, A V; Mendes, J F F

2010-03-01

We obtained Pearson's coefficient of strongly correlated recursive networks growing by preferential attachment of every new vertex by m edges. We found that the Pearson coefficient is exactly zero in the infinite network limit for the recursive trees (m=1). If the number of connections of new vertices exceeds one (m>1), then the Pearson coefficient in the infinite networks equals zero only when the degree distribution exponent gamma does not exceed 4. We calculated the Pearson coefficient for finite networks and observed a slow power-law-like approach to an infinite network limit. Our findings indicate that Pearson's coefficient strongly depends on size and details of networks, which makes this characteristic virtually useless for quantitative comparison of different networks.

Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: A postmortem study

PubMed Central

Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q.; Ducote, Justin L.; Su, Min-Ying; Molloi, Sabee

2013-01-01

Purpose: Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. Methods: T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left–right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson's r, was used to evaluate the two image segmentation algorithms and the effect of bias field. Results: The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left–right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left–right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson's r increased from 0.86 to 0.92 with the bias field correction. Conclusions: The investigated CLIC method significantly increased the precision and accuracy of breast density quantification using breast MRI images by effectively correcting the bias field. It is expected that a fully automated computerized algorithm for breast density quantification may have great potential in clinical MRI applications. PMID:24320536

Breast density quantification using magnetic resonance imaging (MRI) with bias field correction: a postmortem study.

PubMed

Ding, Huanjun; Johnson, Travis; Lin, Muqing; Le, Huy Q; Ducote, Justin L; Su, Min-Ying; Molloi, Sabee

2013-12-01

Quantification of breast density based on three-dimensional breast MRI may provide useful information for the early detection of breast cancer. However, the field inhomogeneity can severely challenge the computerized image segmentation process. In this work, the effect of the bias field in breast density quantification has been investigated with a postmortem study. T1-weighted images of 20 pairs of postmortem breasts were acquired on a 1.5 T breast MRI scanner. Two computer-assisted algorithms were used to quantify the volumetric breast density. First, standard fuzzy c-means (FCM) clustering was used on raw images with the bias field present. Then, the coherent local intensity clustering (CLIC) method estimated and corrected the bias field during the iterative tissue segmentation process. Finally, FCM clustering was performed on the bias-field-corrected images produced by CLIC method. The left-right correlation for breasts in the same pair was studied for both segmentation algorithms to evaluate the precision of the tissue classification. Finally, the breast densities measured with the three methods were compared to the gold standard tissue compositions obtained from chemical analysis. The linear correlation coefficient, Pearson's r, was used to evaluate the two image segmentation algorithms and the effect of bias field. The CLIC method successfully corrected the intensity inhomogeneity induced by the bias field. In left-right comparisons, the CLIC method significantly improved the slope and the correlation coefficient of the linear fitting for the glandular volume estimation. The left-right breast density correlation was also increased from 0.93 to 0.98. When compared with the percent fibroglandular volume (%FGV) from chemical analysis, results after bias field correction from both the CLIC the FCM algorithms showed improved linear correlation. As a result, the Pearson's r increased from 0.86 to 0.92 with the bias field correction. The investigated CLIC method significantly increased the precision and accuracy of breast density quantification using breast MRI images by effectively correcting the bias field. It is expected that a fully automated computerized algorithm for breast density quantification may have great potential in clinical MRI applications.

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.

Simple Estimation of the Endolymphatic Volume Ratio after Intravenous Administration of a Single-dose of Gadolinium Contrast

PubMed Central

NAGANAWA, Shinji; KANOU, Mai; OHASHI, Toshio; KUNO, Kayao; SONE, Michihiko

2016-01-01

Purpose: To evaluate the feasibility of a simple estimation for the endolymphatic volume ratio (endolymph volume/total lymph volume = %ELvolume) from an area ratio obtained from only one slice (%EL1slice) or from three slices (%EL3slices). The %ELvolume, calculated from a time-consuming measurement on all magnetic resonance (MR) slices, was compared to the %EL1slice and the %EL3slices. Methods: In 40 ears of 20 patients with a clinical suspicion of endolymphatic hydrops, MR imaging was performed 4 hours after intravenous administration of a single dose of gadolinium-based contrast material (IV-SD-GBCM). Using previously reported HYDROPS2-Mi2 MR imaging, the %ELvolume values in the cochlea and the vestibule were measured separately by two observers. The correlations between the %EL1slice or the %EL3slices and the %ELvolume values were evaluated. Results: A strong linear correlation was observed between the %ELvolume and the %EL3slices or the %EL1slice in the cochlea. The Pearson correlation coefficient (r) was 0.968 (3 slices) and 0.965 (1 slice) for observer A, and 0.968 (3 slices) and 0.964 (1 slice) for observer B (P < 0.001, for all). A strong linear correlation was also observed between the %ELvolume and the %EL3slices or the %EL1slice in the vestibule. The Pearson correlation coefficient (r) was 0.980 (3 slices) and 0.953 (1 slice) for observer A, and 0.979 (3 slices) and 0.952 (1 slice) for observer B (P < 0.001, for all). The high intra-class correlation coefficients (0.991–0.997) between the endolymph volume ratios by two observers were observed in both the cochlea and the vestibule for values of the %ELvolume, the %EL3slices and the %EL1slice. Conclusion: The %ELvolume might be easily estimated from the %EL3slices or the %EL1slice. PMID:27001396

Simple Estimation of the Endolymphatic Volume Ratio after Intravenous Administration of a Single-dose of Gadolinium Contrast.

PubMed

Naganawa, Shinji; Kanou, Mai; Ohashi, Toshio; Kuno, Kayao; Sone, Michihiko

2016-10-11

To evaluate the feasibility of a simple estimation for the endolymphatic volume ratio (endolymph volume/total lymph volume = %EL volume ) from an area ratio obtained from only one slice (%EL 1slice ) or from three slices (%EL 3slices ). The %EL volume, calculated from a time-consuming measurement on all magnetic resonance (MR) slices, was compared to the %EL 1slice and the %EL 3slices . In 40 ears of 20 patients with a clinical suspicion of endolymphatic hydrops, MR imaging was performed 4 hours after intravenous administration of a single dose of gadolinium-based contrast material (IV-SD-GBCM). Using previously reported HYDROPS2-Mi2 MR imaging, the %EL volume values in the cochlea and the vestibule were measured separately by two observers. The correlations between the %EL 1slice or the %EL 3slices and the %EL volume values were evaluated. A strong linear correlation was observed between the %EL volume and the %EL 3slices or the %EL 1slice in the cochlea. The Pearson correlation coefficient (r) was 0.968 (3 slices) and 0.965 (1 slice) for observer A, and 0.968 (3 slices) and 0.964 (1 slice) for observer B (P < 0.001, for all). A strong linear correlation was also observed between the %EL volume and the %EL 3slices or the %EL 1slice in the vestibule. The Pearson correlation coefficient (r) was 0.980 (3 slices) and 0.953 (1 slice) for observer A, and 0.979 (3 slices) and 0.952 (1 slice) for observer B (P < 0.001, for all). The high intra-class correlation coefficients (0.991-0.997) between the endolymph volume ratios by two observers were observed in both the cochlea and the vestibule for values of the %EL volume , the %EL 3slices and the %EL 1slice . The %EL volume might be easily estimated from the %EL 3slices or the %EL 1slice .

Wind turbine sound pressure level calculations at dwellings.

PubMed

Keith, Stephen E; Feder, Katya; Voicescu, Sonia A; Soukhovtsev, Victor; Denning, Allison; Tsang, Jason; Broner, Norm; Leroux, Tony; Richarz, Werner; van den Berg, Frits

2016-03-01

This paper provides calculations of outdoor sound pressure levels (SPLs) at dwellings for 10 wind turbine models, to support Health Canada's Community Noise and Health Study. Manufacturer supplied and measured wind turbine sound power levels were used to calculate outdoor SPL at 1238 dwellings using ISO [(1996). ISO 9613-2-Acoustics] and a Swedish noise propagation method. Both methods yielded statistically equivalent results. The A- and C-weighted results were highly correlated over the 1238 dwellings (Pearson's linear correlation coefficient r > 0.8). Calculated wind turbine SPLs were compared to ambient SPLs from other sources, estimated using guidance documents from the United States and Alberta, Canada.

Biochemical and Genetic Markers in Aggressiveness and Recurrence of Prostate Cancer: Race-Specific Links to Inflammation and Insulin Resistance

DTIC Science & Technology

2013-07-01

as a statistical graphic, and Pearson product moment correlation coefficients as measures of the strength of linear association; 4) performing SNP ...determine if there are differences in single nucleotide polymorphisms ( SNPs ) in selected candidate genes implicated in metabolic syndrome, obesity, chronic...samples for the serum and SNP analyses. We have reached a target of 500 patients at the end of year 2; however, some of the patients turned out to be

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).…

Testing the significance of a correlation with nonnormal data: comparison of Pearson, Spearman, transformation, and resampling approaches.

PubMed

Bishara, Anthony J; Hittner, James B

2012-09-01

It is well known that when data are nonnormally distributed, a test of the significance of Pearson's r may inflate Type I error rates and reduce power. Statistics textbooks and the simulation literature provide several alternatives to Pearson's correlation. However, the relative performance of these alternatives has been unclear. Two simulation studies were conducted to compare 12 methods, including Pearson, Spearman's rank-order, transformation, and resampling approaches. With most sample sizes (n ≥ 20), Type I and Type II error rates were minimized by transforming the data to a normal shape prior to assessing the Pearson correlation. Among transformation approaches, a general purpose rank-based inverse normal transformation (i.e., transformation to rankit scores) was most beneficial. However, when samples were both small (n ≤ 10) and extremely nonnormal, the permutation test often outperformed other alternatives, including various bootstrap tests.

Normative biometrics for fetal ocular growth using volumetric MRI reconstruction.

PubMed

Velasco-Annis, Clemente; Gholipour, Ali; Afacan, Onur; Prabhu, Sanjay P; Estroff, Judy A; Warfield, Simon K

2015-04-01

To determine normative ranges for fetal ocular biometrics between 19 and 38 weeks gestational age (GA) using volumetric MRI reconstruction. The 3D images of 114 healthy fetuses between 19 and 38 weeks GA were created using super-resolution volume reconstructions from MRI slice acquisitions. These 3D images were semi-automatically segmented to measure fetal orbit volume, binocular distance (BOD), interocular distance (IOD), and ocular diameter (OD). All biometry correlated with GA (Volume, Pearson's correlation coefficient (CC) = 0.9680; BOD, CC = 0.9552; OD, CC = 0.9445; and IOD, CC = 0.8429), and growth curves were plotted against linear and quadratic growth models. Regression analysis showed quadratic models to best fit BOD, IOD, and OD and a linear model to best fit volume. Orbital volume had the greatest correlation with GA, although BOD and OD also showed strong correlation. The normative data found in this study may be helpful for the detection of congenital fetal anomalies with more consistent measurements than are currently available. © 2015 John Wiley & Sons, Ltd. © 2015 John Wiley & Sons, Ltd.

The relationship of maternal-fetal attachment and depression with social support in pregnant women referring to health centers of Tabriz-Iran, 2016.

PubMed

Delavari, Mina; Mirghafourvand, Mojgan; Mohammad-Alizadeh-Charandabi, Sakineh

2018-09-01

The objective of this study was to determine the relationship of maternal-fetal attachment and depression during pregnancy with social support. This cross-sectional study was done on 287 primipara women. The data collection tools used included a demographic characteristics questionnaire, Maternal-Fetal Attachment Scale, the Edinburgh Postnatal Depression Scale and the Social Support Scale. Pearson's correlation test and general linear model were used for data analysis. The mean maternal-fetal attachment score was 90.0 (SD: 10.3). The highest score was obtained in the "role taking" domain and the lowest in the "interaction with the fetus" domain. The mean depression score was 8.5 (SD: 4.0). The score of perceived social support was 135.5 (SD: 15.6). Pearson's correlation test showed a significant positive correlation between social support and maternal-fetal attachment (r = 0.36, p < .001) and a significant negative correlation between social support and depression (r= -0.14, p = .018). The present study found a significant relationship between maternal-fetal attachment, depression and social support. It is recommended to devise plans for increasing the support given to women and to improve the society's and families' awareness about these issues in the attempt to have healthy mothers and thereby healthy families and communities.

Geographic Variation in Morbidity and Mortality of Cerebrovascular Diseases in Korea during 2011-2015.

PubMed

Lee, Juyeon; Bahk, Jinwook; Kim, Ikhan; Kim, Yeon-Yong; Yun, Sung-Cheol; Kang, Hee-Yeon; Lee, Jeehye; Park, Jong Heon; Shin, Soon-Ae; Khang, Young-Ho

2018-03-01

Little is known about within-country variation in morbidity and mortality of cerebrovascular diseases (CVDs). Geographic differences in CVD morbidity and mortality have yet to be properly examined. This study examined geographic variation in morbidity and mortality of CVD, neighborhood factors for CVD morbidity and mortality, and the association between CVD morbidity and mortality across the 245 local districts in Korea during 2011-2015. District-level health care utilization and mortality data were obtained to estimate age-standardized CVD morbidity and mortality. The bivariate Pearson correlation was used to examine the linear relationship between district-level CVD morbidity and mortality Z-scores. Simple linear regression and multivariate analyses were conducted to investigate the associations of area characteristics with CVD morbidity, mortality, and discrepancies between morbidity and mortality. Substantial variation was found in CVD morbidity and mortality across the country, with 1074.9 excess CVD inpatients and 73.8 excess CVD deaths per 100,000 between the districts with the lowest and highest CVD morbidity and mortality, respectively. Higher rates of CVD admissions and deaths were clustered in the noncapital regions. A moderate geographic correlation between CVD morbidity and mortality was found (Pearson correlation coefficient = .62 for both genders). Neighborhood level indicators for socioeconomic disadvantages, undersupply of health care resources, and unhealthy behaviors were positively associated with CVD morbidity and mortality and the relative standing of CVD mortality vis-à-vis morbidity. Policy actions targeting life-course socioeconomic conditions, equitable distribution of health care resources, and behavioral risk factors may help reduce geographic differences in CVD morbidity and mortality in Korea. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Predictive value of grade point average (GPA), Medical College Admission Test (MCAT), internal examinations (Block) and National Board of Medical Examiners (NBME) scores on Medical Council of Canada qualifying examination part I (MCCQE-1) scores.

PubMed

Roy, Banibrata; Ripstein, Ira; Perry, Kyle; Cohen, Barry

2016-01-01

To determine whether the pre-medical Grade Point Average (GPA), Medical College Admission Test (MCAT), Internal examinations (Block) and National Board of Medical Examiners (NBME) scores are correlated with and predict the Medical Council of Canada Qualifying Examination Part I (MCCQE-1) scores. Data from 392 admitted students in the graduating classes of 2010-2013 at University of Manitoba (UofM), College of Medicine was considered. Pearson's correlation to assess the strength of the relationship, multiple linear regression to estimate MCCQE-1 score and stepwise linear regression to investigate the amount of variance were employed. Complete data from 367 (94%) students were studied. The MCCQE-1 had a moderate-to-large positive correlation with NBME scores and Block scores but a low correlation with GPA and MCAT scores. The multiple linear regression model gives a good estimate of the MCCQE-1 (R2 =0.604). Stepwise regression analysis demonstrated that 59.2% of the variation in the MCCQE-1 was accounted for by the NBME, but only 1.9% by the Block exams, and negligible variation came from the GPA and the MCAT. Amongst all the examinations used at UofM, the NBME is most closely correlated with MCCQE-1.

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.

Comparison between uroflowmetry and sonouroflowmetry in recording of urinary flow in healthy men.

PubMed

Krhut, Jan; Gärtner, Marcel; Sýkora, Radek; Hurtík, Petr; Burda, Michal; Luňáček, Libor; Zvarová, Katarína; Zvara, Peter

2015-08-01

To evaluate the accuracy of sonouroflowmetry in recording urinary flow parameters and voided volume. A total of 25 healthy male volunteers (age 18-63 years) were included in the study. All participants were asked to carry out uroflowmetry synchronous with recording of the sound generated by the urine stream hitting the water level in the urine collection receptacle, using a dedicated cell phone. From 188 recordings, 34 were excluded, because of voided volume <150 mL or technical problems during recording. Sonouroflowmetry recording was visualized in a form of a trace, representing sound intensity over time. Subsequently, the matching datasets of uroflowmetry and sonouroflowmetry were compared with respect to flow time, voided volume, maximum flow rate and average flow rate. Pearson's correlation coefficient was used to compare parameters recorded by uroflowmetry with those calculated based on sonouroflowmetry recordings. The flow pattern recorded by sonouroflowmetry showed a good correlation with the uroflowmetry trace. A strong correlation (Pearson's correlation coefficient 0.87) was documented between uroflowmetry-recorded flow time and duration of the sound signal recorded with sonouroflowmetry. A moderate correlation was observed in voided volume (Pearson's correlation coefficient 0.68) and average flow rate (Pearson's correlation coefficient 0.57). A weak correlation (Pearson's correlation coefficient 0.38) between maximum flow rate recorded using uroflowmetry and sonouroflowmetry-recorded peak sound intensity was documented. The present study shows that the basic concept utilizing sound analysis for estimation of urinary flow parameters and voided volume is valid. However, further development of this technology and standardization of recording algorithm are required. © 2015 The Japanese Urological Association.

An efficient sensitivity analysis method for modified geometry of Macpherson suspension based on Pearson correlation coefficient

NASA Astrophysics Data System (ADS)

Shojaeefard, Mohammad Hasan; Khalkhali, Abolfazl; Yarmohammadisatri, Sadegh

2017-06-01

The main purpose of this paper is to propose a new method for designing Macpherson suspension, based on the Sobol indices in terms of Pearson correlation which determines the importance of each member on the behaviour of vehicle suspension. The formulation of dynamic analysis of Macpherson suspension system is developed using the suspension members as the modified links in order to achieve the desired kinematic behaviour. The mechanical system is replaced with an equivalent constrained links and then kinematic laws are utilised to obtain a new modified geometry of Macpherson suspension. The equivalent mechanism of Macpherson suspension increased the speed of analysis and reduced its complexity. The ADAMS/CAR software is utilised to simulate a full vehicle, Renault Logan car, in order to analyse the accuracy of modified geometry model. An experimental 4-poster test rig is considered for validating both ADAMS/CAR simulation and analytical geometry model. Pearson correlation coefficient is applied to analyse the sensitivity of each suspension member according to vehicle objective functions such as sprung mass acceleration, etc. Besides this matter, the estimation of Pearson correlation coefficient between variables is analysed in this method. It is understood that the Pearson correlation coefficient is an efficient method for analysing the vehicle suspension which leads to a better design of Macpherson suspension system.

A combined evaluation of the characteristics and acute toxicity of antibiotic wastewater.

PubMed

Yu, Xin; Zuo, Jiane; Li, Ruixia; Gan, Lili; Li, Zaixing; Zhang, Fei

2014-08-01

The conventional parameters and acute toxicities of antibiotic wastewater collected from each treatment unit of an antibiotic wastewater treatment plant have been investigated. The investigation of the conventional parameters indicated that the antibiotic wastewater treatment plant performed well under the significant fluctuation in influent water quality. The results of acute toxicity indicated that the toxicity of antibiotic wastewater could be reduced by 94.3 percent on average after treatment. However, treated antibiotic effluents were still toxic to Vibrio fischeri. The toxicity of antibiotic production wastewater could be attributed to the joint effects of toxic compound mixtures in wastewater. Moreover, aerobic biological treatment processes, including sequencing batch reactor (SBR) and aerobic biofilm reactor, played the most important role in reducing toxicity by 92.4 percent. Pearson׳s correlation coefficients revealed that toxicity had a strong and positive linear correlation with organic substances, nitrogenous compounds, S(2-), volatile phenol, cyanide, As, Zn, Cd, Ni and Fe. Ammonia nitrogen (NH4(+)) was the greatest contributor to toxicity according to the stepwise regression method. The multiple regression model was a good fit for [TU50-15 min] as a function of [NH₄(+)] with the determination coefficient of 0.981. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance Analysis of Occurrences January 1, 2011-December 31, 2011

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

Ludwig, M

2012-03-16

This report documents the analysis of the occurrences during the period January 1, 2011 through December 31, 2011. The report compares LLNL occurrences by reporting criteria and significance category to see if LLNL is reporting occurrences along similar percentages as other DOE sites. The three-year trends are analyzed. It does not include the analysis of the causes or the lessons learned from the occurrences, as they are analyzed separately. The number and types of occurrences that LLNL reports to DOE varies over time. This variation can be attributed to normally occurring changes in frequency; DOE's or LLNL's heightened interest inmore » a particular subject area; changes in LLNL processes; or emerging problems. Since all of the DOE sites use the same reporting criteria, it is helpful to understand if LLNL is consistent with or diverging from reporting at other sites. This section compares the normalized number of occurrences reported by LLNL and other DOE sites. In order to compare LLNL occurrence reports to occurrence reports from other DOE sites, we normalized (or standardized) the data from the sites. DOE sites vary widely in their budgets, populations, and scope of work and these variations may affect reporting frequency. In addition, reports are required for a wide range of occurrence types, some of which may not be applicable to all DOE sites. For example, one occurrence reporting group is Group 3, Nuclear Safety Basis, and not all sites have nuclear operations. Because limited information is available for all sites, the sites were normalized based on best available information. Site effort hours were extracted from the DOE Computerized Accident Incident Reporting System (CAIRS) and used to normalize (or standardize) the number of occurrences by site. Effort hours are those hours that employees normally work and do not include vacation, holiday hours etc. Sites are responsible for calculating their effort hours and ensuring entry into CAIRS. Out of the 30 DOE sites that reported occurrences into ORPS during January 2011 through December 2011, 28 had effort hours available in CAIRS. Two sites had not submitted effort hours data to CAIRS as of the time data was pulled for this report. In those two cases, third quarter data was used as an estimate of fourth quarter data. The use of estimated data may introduce minor errors in the average, median, and Pearson calculations. Using the effort hours and the frequency of occurrences by site, a rate of occurrence frequency per 100 FTE workers was calculated. This rate is similar to the injury/illness frequency rate: the number of injury/illness cases per 100 FTE workers. To validate that this rate was appropriate to use, we compared the effort hours and the frequency of occurrences by site to determine if a relationship exists between the two, e.g. the more effort hours a site has, the more occurrences they tend to have. This hypothesis was tested using the Pearson Correlation Coefficient Test. The correlation coefficient measures the strength of the linear relationship between effort hours and occurrence frequency. The Pearson Correlation Coefficient Test will determine if the true correlation coefficient is equal to zero (no relationship exists), or if the correlation coefficient is not equal to zero (a relationship exists). Values approaching 1.00 show a more positive correlation. Simple linear regression was also used to display a trend line and to test if a one-way relationship exists between effort hours predicting the number of occurrences a site will have. Using the Pearson Correlation test, for the NNSA sites, effort hours and the number of occurrences are significantly and positively correlated with a correlation coefficient of 0.90, as was also seen in the previous report (correlation coefficient of 0.67). All DOE sites are positively correlated with a coefficient of 0.85. As the effort hours increase, so does the number of occurrences and vice versa. Based on the results of the simple linear regression, effort hours were found to predict the number of occurrences.« less

Robustness of Two Formulas to Correct Pearson Correlation for Restriction of Range

ERIC Educational Resources Information Center

tran, minh

2011-01-01

Many research studies involving Pearson correlations are conducted in settings where one of the two variables has a restricted range in the sample. For example, this situation occurs when tests are used for selecting candidates for employment or university admission. Often after selection, there is interest in correlating the selection variable,…

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…

Correlation between centrality metrics and their application to the opinion model

NASA Astrophysics Data System (ADS)

Li, Cong; Li, Qian; Van Mieghem, Piet; Stanley, H. Eugene; Wang, Huijuan

2015-03-01

In recent decades, a number of centrality metrics describing network properties of nodes have been proposed to rank the importance of nodes. In order to understand the correlations between centrality metrics and to approximate a high-complexity centrality metric by a strongly correlated low-complexity metric, we first study the correlation between centrality metrics in terms of their Pearson correlation coefficient and their similarity in ranking of nodes. In addition to considering the widely used centrality metrics, we introduce a new centrality measure, the degree mass. The mth-order degree mass of a node is the sum of the weighted degree of the node and its neighbors no further than m hops away. We find that the betweenness, the closeness, and the components of the principal eigenvector of the adjacency matrix are strongly correlated with the degree, the 1st-order degree mass and the 2nd-order degree mass, respectively, in both network models and real-world networks. We then theoretically prove that the Pearson correlation coefficient between the principal eigenvector and the 2nd-order degree mass is larger than that between the principal eigenvector and a lower order degree mass. Finally, we investigate the effect of the inflexible contrarians selected based on different centrality metrics in helping one opinion to compete with another in the inflexible contrarian opinion (ICO) model. Interestingly, we find that selecting the inflexible contrarians based on the leverage, the betweenness, or the degree is more effective in opinion-competition than using other centrality metrics in all types of networks. This observation is supported by our previous observations, i.e., that there is a strong linear correlation between the degree and the betweenness, as well as a high centrality similarity between the leverage and the degree.

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.

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.

The relationship between indoor and outdoor temperature, apparent temperature, relative humidity, and absolute humidity

PubMed Central

Nguyen, Jennifer L.; Schwartz, Joel; Dockery, Douglas W.

2013-01-01

Introduction Many studies report an association between outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to outdoor ambient weather. Methods and Results The average indoor temperature, apparent temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 - April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and outdoor temperatures is non-linear. At warmer outdoor temperatures, there is a strong correlation between indoor and outdoor temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for outdoor apparent temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). AH exhibited the strongest indoor-to-outdoor correlation (r = 0.96, β = 0.69). Conclusions Indoor and outdoor temperatures correlate well only at warmer outdoor temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with outdoor AH year-round. PMID:23710826

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.

Plasma apelin levels, blood pressure and cardiovascular risk factors in a coastal Chinese population.

PubMed

Zhu, Pengli; Huang, Feng; Lin, Fan; Yuan, Yin; Chen, Falin; Li, Qiaowei

2013-11-01

To describe the relationship of plasma apelin levels with blood pressure in a coastal Chinese population. This cross-sectional study included a total of 1031 subjects from the coastal areas of China. One-way analysis of variance (ANOVA) and linear trend test, Pearson's correlation analysis, as well as multivariate linear regression analysis were used to evaluate the association between plasma apelin levels and blood pressure. Plasma apelin levels dropped with increasing quartiles of systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MABP) (all P<0.001). SBP, DBP, and MABP values decreased as the apelin levels increased within the quartiles. After adjusting for age and gender, the significant differences in SBP, DBP, and MABP between the groups within the apelin quartiles remained (all P<0.05). A significant negative correlation between SBP, DBP, as well as MABP and apelin levels was observed (all P<0.01); even after adjusting for cardiovascular confounding factors, this negative correlation remained (all P<0.001). A negative correlation between plasma apelin levels and blood pressure was found in this 1000-population-based epidemiological study. Apelin may become a potential therapeutic target of anti-hypertensive treatment.

The Evolution of Pearson's Correlation Coefficient

ERIC Educational Resources Information Center

Kader, Gary D.; Franklin, Christine A.

2008-01-01

This article describes an activity for developing the notion of association between two quantitative variables. By exploring a collection of scatter plots, the authors propose a nonstandard "intuitive" measure of association; and by examining properties of this measure, they develop the more standard measure, Pearson's Correlation Coefficient. The…

Circulating CD34-Positive Cells Are Associated with Handgrip Strength in Japanese Older Men: The Nagasaki Islands Study.

PubMed

Yamanashi, H; Shimizu, Y; Koyamatsu, J; Nagayoshi, M; Kadota, K; Tamai, M; Maeda, T

2017-01-01

Handgrip strength is a simple measurement of overall muscular strength and is used to detect sarcopenia. It also predicts adverse events in later life. Many mechanisms of sarcopenia development have been reported. A hypertensive status impairs endothelial dysfunction, which might deteriorate skeletal muscle if vascular angiogenesis is not maintained. This study investigated muscle strength and circulating CD34-positive cells as a marker of vascular angiogenesis. Cross-sectional study. 262 male Japanese community dwellers aged 60 to 69 years. The participants' handgrip strength, medical history, and blood samples were taken. We stratified the participants by hypertensive status to investigate the association between handgrip strength and circulating CD34-positive cells according to hypertensive status. Pearson correlation and linear regression analyses were used. In the Pearson correlation analysis, handgrip strength and the logarithm of circulating CD34-positive cells were significantly associated in hypertensive participants (r=0.22, p=0.021), but not in non-hypertensive participants (r=-0.01, p=0.943). This relationship was only significant in hypertensive participants (ß=1.94, p=0.021) in the simple linear regression analysis, and it remained significant after adjusting for classic cardiovascular risk factors (ß=1.92, p=0.020). The relationship was not significant in non-hypertensive participants (ß=-0.09, p=0.903). We found a positive association between handgrip strength and circulating CD34-positive cells in hypertensive men. Vascular maintenance attributed by circulating CD34-positive cells is thought to be a background mechanism of this association after hypertension-induced vascular injury in skeletal muscle.

Osteoporosis prediction from the mandible using cone-beam computed tomography

PubMed Central

Al Haffar, Iyad; Khattab, Razan

2014-01-01

Purpose This study aimed to evaluate the use of dental cone-beam computed tomography (CBCT) in the diagnosis of osteoporosis among menopausal and postmenopausal women by using only a CBCT viewer program. Materials and Methods Thirty-eight menopausal and postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) examination for hip and lumbar vertebrae were scanned using CBCT (field of view: 13 cm×15 cm; voxel size: 0.25 mm). Slices from the body of the mandible as well as the ramus were selected and some CBCT-derived variables, such as radiographic density (RD) as gray values, were calculated as gray values. Pearson's correlation, one-way analysis of variance (ANOVA), and accuracy (sensitivity and specificity) evaluation based on linear and logistic regression were performed to choose the variable that best correlated with the lumbar and femoral neck T-scores. Results RD of the whole bone area of the mandible was the variable that best correlated with and predicted both the femoral neck and the lumbar vertebrae T-scores; further, Pearson's correlation coefficients were 0.5/0.6 (p value=0.037/0.009). The sensitivity, specificity, and accuracy based on the logistic regression were 50%, 88.9%, and 78.4%, respectively, for the femoral neck, and 46.2%, 91.3%, and 75%, respectively, for the lumbar vertebrae. Conclusion Lumbar vertebrae and femoral neck osteoporosis can be predicted with high accuracy from the RD value of the body of the mandible by using a CBCT viewer program. PMID:25473633

Colocalization analysis in fluorescence micrographs: verification of a more accurate calculation of pearson's correlation coefficient.

PubMed

Barlow, Andrew L; Macleod, Alasdair; Noppen, Samuel; Sanderson, Jeremy; Guérin, Christopher J

2010-12-01

One of the most routine uses of fluorescence microscopy is colocalization, i.e., the demonstration of a relationship between pairs of biological molecules. Frequently this is presented simplistically by the use of overlays of red and green images, with areas of yellow indicating colocalization of the molecules. Colocalization data are rarely quantified and can be misleading. Our results from both synthetic and biological datasets demonstrate that the generation of Pearson's correlation coefficient between pairs of images can overestimate positive correlation and fail to demonstrate negative correlation. We have demonstrated that the calculation of a thresholded Pearson's correlation coefficient using only intensity values over a determined threshold in both channels produces numerical values that more accurately describe both synthetic datasets and biological examples. Its use will bring clarity and accuracy to colocalization studies using fluorescent microscopy.

Age estimation by dentin translucency measurement using digital method: An institutional study

PubMed Central

Gupta, Shalini; Chandra, Akhilesh; Agnihotri, Archana; Gupta, Om Prakash; Maurya, Niharika

2017-01-01

Aims: The aims of the present study were to measure translucency on sectioned teeth using available computer hardware and software, to correlate dimensions of root dentin translucency with age, and to assess whether translucency is reliable for age estimation. Materials and Methods: A pilot study was done on 62 freshly extracted single-rooted permanent teeth from 62 different individuals (35 males and 27 females) and their 250 μm thick sections were prepared by micromotor, carborundum disks, and Arkansas stone. Each tooth section was scanned and the images were opened in the Adobe Photoshop software. Measurement of root dentin translucency (TD length) was done on the scanned image by placing two guides (A and B) along the x-axis of ABFO NO. 2 scale. Unpaired t-test, regression analysis, and Pearson correlation coefficient were used as statistical tools. Results: A linear relationship was observed between TD length and age in the regression analysis. The Pearson correlation analysis showed that there was positive correlation (r = 0.52, P = 0.0001) between TD length and age. However, no significant (P > 0.05) difference was observed in the TD length between male (8.44 ± 2.92 mm) and female (7.80 ± 2.79 mm) samples. Conclusion: Translucency of the root dentin increases with age and it can be used as a reliable parameter for the age estimation. The method used here to digitally select and measure translucent root dentin is more refined, better correlated to age, and produce superior age estimation. PMID:28584476

Evaluation of pharyngeal space and its correlation with mandible and hyoid bone in patients with different skeletal classes and facial types.

PubMed

Nejaim, Yuri; Aps, Johan K M; Groppo, Francisco Carlos; Haiter Neto, Francisco

2018-06-01

The purpose of this article was to evaluate the pharyngeal space volume, and the size and shape of the mandible and the hyoid bone, as well as their relationships, in patients with different facial types and skeletal classes. Furthermore, we estimated the volume of the pharyngeal space with a formula using only linear measurements. A total of 161 i-CAT Next Generation (Imaging Sciences International, Hatfield, Pa) cone-beam computed tomography images (80 men, 81 women; ages, 21-58 years; mean age, 27 years) were retrospectively studied. Skeletal class and facial type were determined for each patient from multiplanar reconstructions using the NemoCeph software (Nemotec, Madrid, Spain). Linear and angular measurements were performed using 3D imaging software (version 3.4.3; Carestream Health, Rochester, NY), and volumetric analysis of the pharyngeal space was carried out with ITK-SNAP (version 2.4.0; Cognitica, Philadelphia, Pa) segmentation software. For the statistics, analysis of variance and the Tukey test with a significance level of 0.05, Pearson correlation, and linear regression were used. The pharyngeal space volume, when correlated with mandible and hyoid bone linear and angular measurements, showed significant correlations with skeletal class or facial type. The linear regression performed to estimate the volume of the pharyngeal space showed an R of 0.92 and an adjusted R 2 of 0.8362. There were significant correlations between pharyngeal space volume, and the mandible and hyoid bone measurements, suggesting that the stomatognathic system should be evaluated in an integral and nonindividualized way. Furthermore, it was possible to develop a linear regression model, resulting in a useful formula for estimating the volume of the pharyngeal space. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Zero Pearson coefficient for strongly correlated growing trees

NASA Astrophysics Data System (ADS)

Dorogovtsev, S. N.; Ferreira, A. L.; Goltsev, A. V.; Mendes, J. F. F.

2010-03-01

We obtained Pearson’s coefficient of strongly correlated recursive networks growing by preferential attachment of every new vertex by m edges. We found that the Pearson coefficient is exactly zero in the infinite network limit for the recursive trees (m=1) . If the number of connections of new vertices exceeds one (m>1) , then the Pearson coefficient in the infinite networks equals zero only when the degree distribution exponent γ does not exceed 4. We calculated the Pearson coefficient for finite networks and observed a slow power-law-like approach to an infinite network limit. Our findings indicate that Pearson’s coefficient strongly depends on size and details of networks, which makes this characteristic virtually useless for quantitative comparison of different networks.

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.

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

[Relationship between gender and age with quality of life in chronic hemodialysis patients].

PubMed

Santos, Paulo Roberto

2006-01-01

The stagnant mortality rate of the last decade and the increased prevalence of aged people among hemodialysis patients motivated the present study to determine the relation of gender and age with the quality of life (QL) of patients with chronic kidney failure treated with hemodialysis. From the sample of 107 individuals who underwent regular hemodialysis in a Dialysis Unit in the interior of the state of Ceará, Brazil, the Medical Outcomes Study Questionnaire 36-Item Short Form Health Survey (SF-36) was used to assess quality of life. Pearson's correlation coefficient was used to calculate and to test the linear correlation between age and the score generated by the SF-36. The score for gender was compared by the t test and the Mann-Whitney when indicated. There was no difference between the score related to gender. There was no negative and linear correlation between age and the dimensions of QL named: Physical Functioning (r=-0.289, p=0.003), Physical Role (r=-0.224, p=0.020), Body Pain (r=0.252, p=0.008), General Health (r=-0.245, p<0.001), Vitality (r=-0.334, p<0.001) and Social Functioning (r=-0.270, p=0.005). There was no correlation between age and the dimensions: Role of Emotions (r=-0.149, p=0.125) and Mental Health (r=-0.158, p=0.103). Gender did not correlate with the level of QL among chronic hemodialysis patients, while there was a linear and negative correlation between age and the dimensions relating to the physical aspect of the QL.

Effect of Ankle Range of Motion (ROM) and Lower-Extremity Muscle Strength on Static Balance Control Ability in Young Adults: A Regression Analysis

PubMed Central

Kim, Seong-Gil

2018-01-01

Background The purpose of this study was to investigate the effect of ankle ROM and lower-extremity muscle strength on static balance control ability in young adults. Material/Methods This study was conducted with 65 young adults, but 10 young adults dropped out during the measurement, so 55 young adults (male: 19, female: 36) completed the study. Postural sway (length and velocity) was measured with eyes open and closed, and ankle ROM (AROM and PROM of dorsiflexion and plantarflexion) and lower-extremity muscle strength (flexor and extensor of hip, knee, and ankle joint) were measured. Pearson correlation coefficient was used to examine the correlation between variables and static balance ability. Simple linear regression analysis and multiple linear regression analysis were used to examine the effect of variables on static balance ability. Results In correlation analysis, plantarflexion ROM (AROM and PROM) and lower-extremity muscle strength (except hip extensor) were significantly correlated with postural sway (p<0.05). In simple correlation analysis, all variables that passed the correlation analysis procedure had significant influence (p<0.05). In multiple linear regression analysis, plantar flexion PROM with eyes open significantly influenced sway length (B=0.681) and sway velocity (B=0.011). Conclusions Lower-extremity muscle strength and ankle plantarflexion ROM influenced static balance control ability, with ankle plantarflexion PROM showing the greatest influence. Therefore, both contractile structures and non-contractile structures should be of interest when considering static balance control ability improvement. PMID:29760375

Effect of Ankle Range of Motion (ROM) and Lower-Extremity Muscle Strength on Static Balance Control Ability in Young Adults: A Regression Analysis.

PubMed

Kim, Seong-Gil; Kim, Wan-Soo

2018-05-15

BACKGROUND The purpose of this study was to investigate the effect of ankle ROM and lower-extremity muscle strength on static balance control ability in young adults. MATERIAL AND METHODS This study was conducted with 65 young adults, but 10 young adults dropped out during the measurement, so 55 young adults (male: 19, female: 36) completed the study. Postural sway (length and velocity) was measured with eyes open and closed, and ankle ROM (AROM and PROM of dorsiflexion and plantarflexion) and lower-extremity muscle strength (flexor and extensor of hip, knee, and ankle joint) were measured. Pearson correlation coefficient was used to examine the correlation between variables and static balance ability. Simple linear regression analysis and multiple linear regression analysis were used to examine the effect of variables on static balance ability. RESULTS In correlation analysis, plantarflexion ROM (AROM and PROM) and lower-extremity muscle strength (except hip extensor) were significantly correlated with postural sway (p<0.05). In simple correlation analysis, all variables that passed the correlation analysis procedure had significant influence (p<0.05). In multiple linear regression analysis, plantar flexion PROM with eyes open significantly influenced sway length (B=0.681) and sway velocity (B=0.011). CONCLUSIONS Lower-extremity muscle strength and ankle plantarflexion ROM influenced static balance control ability, with ankle plantarflexion PROM showing the greatest influence. Therefore, both contractile structures and non-contractile structures should be of interest when considering static balance control ability improvement.

Depression and fatigue in patients with multiple sclerosis.

PubMed

Greeke, Emily E; Chua, Alicia S; Healy, Brian C; Rintell, David J; Chitnis, Tanuja; Glanz, Bonnie I

2017-09-15

Previous research has examined the components of depression and fatigue in multiple sclerosis (MS), but the findings have been inconsistent. The aim of this study was to explore the associations between overall and subscale scores of the Center for Epidemiologic Studies-Depression Scale (CES-D) and the Modified Fatigue Impact Scale (MFIS) as well as the longitudinal changes in scores in a large cohort of MS patients. MS subjects who completed a battery of patient reported outcome (PRO) measures including the CES-D and MFIS (N=435) were included in our analysis. At the first available MFIS measurement, Pearson's correlation coefficient was used to estimate the association between the CES-D and MFIS in terms of both total scores and subscale scores. In addition, the longitudinal change in each total score and subscale score was estimated using a linear mixed model, and the association between the measures in terms of longitudinal change was estimated using Pearson's correlation coefficient and linear mixed models. At baseline, 15% of subjects were classified as high on both depression and fatigue scales, 16% were classified as high on the fatigue scale only, and 9% were classified as high on the depression scale only. There was a high correlation between CES-D and MFIS total scores (r=0.62). High correlations were also observed between the somatic and retarded activity subscales of the CES-D and each of the MFIS subscales (r≥0.60). In terms of longitudinal change, the change over the first year between the CES-D and MFIS total scores showed a moderate correlation (r=0.49). Subjects with high fatigue scores but low depression scores at baseline were more likely than subjects with low baseline fatigue and depression scores to develop high depression scores at follow-up. Our study demonstrated that depression and fatigue in MS share several features and have a similar longitudinal course. But using cut-off scores to define depression and fatigue, our study also found that non-depressed subjects with high fatigue may be at a greater risk for developing depression. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

An anthropometric study to evaluate the correlation between the occlusal vertical dimension and length of the thumb.

PubMed

Basnet, Bishal Babu; Parajuli, Prakash Kumar; Singh, Raj Kumar; Suwal, Pramita; Shrestha, Pragya; Baral, Dharanidhar

2015-01-01

Establishment of proper occlusal vertical dimension (OVD) is one of the important tasks for successful prosthodontic therapy. An ideal method for determining OVD in terms of cost, time, and instrument requirements has been sought in prosthodontics by various investigators. However, no such single method has been formulated. In the current anthropometric study, the relationship of the length of the thumb to the OVD was tested in two ethnic groups of Nepal, Aryans, and Mongoloids. The result of this study can be useful in determining proper OVD in edentulous patients. The primary aim of the present study was to evaluate the correlation between the length of the thumb and OVD in Aryan and Mongoloid ethnic groups. The secondary aim was to compare the correlation between OVD and other anatomic measurements (eye-ear distance and pupil-to-rima oris distance) in these ethnicities. The OVD, thumb length, eye-ear distance and distance between pupil of eye and rima oris were measured in a total of 500 adult dentulous volunteers. The correlation between OVD and thumb length as well as other anatomic measurements was checked with Pearson's product moment correlation coefficient. Linear regression analysis was performed to determine the relationship of OVD to the length of the thumb. The thumb length was significantly (P≤0.05) correlated with strong and positive values (Pearson's coefficient =0.874 in the whole population, 0.826 in Aryans, and 0.944 in Mongoloids). Regression analysis showed that thumb length was significantly related to OVD in both ethnic groups. Within the limitations of the present study, the result implies that thumb length can be used as an adjunct for establishing OVD in the edentulous patients.

Correlation of the NBME advanced clinical examination in EM and the national EM M4 exams.

PubMed

Hiller, Katherine; Miller, Emily S; Lawson, Luan; Wald, David; Beeson, Michael; Heitz, Corey; Morrissey, Thomas; House, Joseph; Poznanski, Stacey

2015-01-01

Since 2011 two online, validated exams for fourth-year emergency medicine (EM) students have been available (National EM M4 Exams). In 2013 the National Board of Medical Examiners offered the Advanced Clinical Examination in Emergency Medicine (EM-ACE). All of these exams are now in widespread use; however, there are no data on how they correlate. This study evaluated the correlation between the EM-ACE exam and the National EM M4 Exams. From May 2013 to April 2014 the EM-ACE and one version of the EM M4 exam were administered sequentially to fourth-year EM students at five U.S. medical schools. Data collected included institution, gross and scaled scores and version of the EM M4 exam. We performed Pearson's correlation and random effects linear regression. 305 students took the EM-ACE and versions 1 (V1) or 2 (V2) of the EM M4 exams (281 and 24, respectively) [corrected].The mean percent correct for the exams were as follows: EM-ACE 74.9 (SD-9.82), V1 83.0 (SD-6.39), V2 78.5 (SD-7.70) [corrected]. Pearson's correlation coefficient for the V1/EM-ACE was 0.53 (0.43 scaled) and for the V2/EM-ACE was 0.58 (0.41 scaled) [corrected]. The coefficient of determination for V1/ EM-ACE was 0.73 and for V2/EM-ACE 0.71 (0.65 and .49 for scaled scores) [ERRATUM]. The R-squared values were 0.28 and 0.30 (0.18 and 0.13 scaled), respectively [corrected]. There was significant cluster effect by institution. There was moderate positive correlation of student scores on the EM-ACE exam and the National EM M4 Exams.

[Clinical significance and distribution of BRCA genes mutation in sporadic high grade serous ovarian cancer].

PubMed

Liu, W L; Wang, Z Z; Zhao, J Z; Hou, Y Y; Wu, X X; Li, W; Dong, B; Tong, T T; Guo, Y J

2017-01-25

Objective: To investigate the mutations of BRCA genes in sporadic high grade serous ovarian cancer (HGSOC) and study its clinical significance. Methods: Sixty-eight patients between January 2015 and January 2016 from the Affiliated Cancer Hospital of Zhengzhou University were collected who were based on pathological diagnosis of ovarian cancer and had no reported family history, and all patients firstly hospitalized were untreated in other hospitals before. (1) The BRCA genes were detected by next-generation sequencing (NGS) method. (2) The serum tumor markers included carcinoembryonic antigen (CEA), CA(125), CA(199), and human epididymis protein 4 (HE4) were detected by the chemiluminescence methods, and their correlation was analyzed by Pearson linear correlation. Descriptive statistics and comparisons were performed using two-tailed t -tests, Pearson's chi square test, Fisher's exact tests or logistic regression analysis as appropriate to research the clinicopathologic features associated with BRCA mutations, including age, International Federation of Gynecology and Obstetrics (FIGO) stage, platinum-based chemotherapy sensitivity, distant metastases, serum tumor markers (STM) . Results: (1) Fifteen cases (22%, 15/68) BRCA mutations were identified (BRCA1: 11 cases; BRCA2: 4 cases), and four novel mutations were observed. (2) The levels of CEA, CA(199), and HE4 were lower in BRCA mutations compared to that in control group, while no significant differences were found ( P >0.05), but the level of CA(125) was much higher in BRCA mutation group than that in controls ( t =-3.536, P =0.003). Further linear regression analysis found that there was a significant linear correlation between CA(125) and HE4 group ( r =0.494, P <0.01), and the same correlation as CEA and CA(199) group ( r =0.897, P <0.01). (3) Single factor analysis showed that no significant differences were observed in onset age, FIGO stage, distant metastasis, and STM between BRCA(+) and BRCA(-) group ( P >0.05), while significant differences were found in CA(125) and sensitivity to platinum-based chemotherapy between the patients with BRCA mutation and wild type ( P <0.05). The multiple factors analysis showed that the high level of CA(125) was a independent risk factor of BRCA mutations in sporadic HGSOC ( P =0.007). Conclusion: The combination of CA(125) with BRCA have great clinical significance, the mutation of BRCA gene could guild the clinical chemotherapy regiments.

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.

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.

Ultrasound transducer shape has no effect on measurements of lumbar multifidus muscle size.

PubMed

Worsley, Peter R; Smith, Nicholas; Warner, Martin B; Stokes, Maria

2012-04-01

Evidence is currently lacking for guidance on ultrasound transducer configuration (shape) when imaging muscle to measure its size. This study compared measurements made of lumbar multifidus on images obtained using curvilinear and linear transducers. Fifteen asymptomatic males (aged 21-32 years) had their right lumbar multifidus imaged at L3. Two transverse images were taken with two transducers (5 MHz curvilinear and 6 MHz linear), and linear and cross-sectional area (CSA) measurements were made off-line. Reliability of image interpretation was shown using intra-class correlation coefficients (0.78-0.99). Muscle measurements were compared between transducers using Bland and Altman plots and paired t-tests. Relationships between CSA and linear measurements were examined using Pearson's Correlation Coefficients. There were no significant differences (p > 0.05) in the measurements of the two transducers. Thickness and CSA measurements had small differences between transducers, with mean differences of 0.01 cm (SDdiff = 0.21 cm) and 0.03 cm(2) (SDdiff = 0.58 cm(2)) respectively. Width measures had a mean difference of 0.14 cm, with the linear transducer giving larger measures. Significant correlations (p < 0.001) were found between all linear measures and CSA, with both transducers (r = 0.78-0.89). Measurements of multifidus at L3 were not influenced by the configuration of transducers of similar frequency. For the purposes of image interpretation, the curvilinear transducer produced better definition of the lateral muscle border, suggesting it as the preferable transducer for imaging lumbar multifidus. Copyright © 2011 Elsevier Ltd. All rights reserved.

Concurrent validity of persian version of wechsler intelligence scale for children - fourth edition and cognitive assessment system in patients with learning disorder.

PubMed

Rostami, Reza; Sadeghi, Vahid; Zarei, Jamileh; Haddadi, Parvaneh; Mohazzab-Torabi, Saman; Salamati, Payman

2013-04-01

The aim of this study was to compare the Persian version of the wechsler intelligence scale for children - fourth edition (WISC-IV) and cognitive assessment system (CAS) tests, to determine the correlation between their scales and to evaluate the probable concurrent validity of these tests in patients with learning disorders. One-hundered-sixty-two children with learning disorder who were presented at Atieh Comprehensive Psychiatry Center were selected in a consecutive non-randomized order. All of the patients were assessed based on WISC-IV and CAS scores questionnaires. Pearson correlation coefficient was used to analyze the correlation between the data and to assess the concurrent validity of the two tests. Linear regression was used for statistical modeling. The type one error was considered 5% in maximum. There was a strong correlation between total score of WISC-IV test and total score of CAS test in the patients (r=0.75, P<0.001). The correlations among the other scales were mostly high and all of them were statistically significant (P<0.001). A linear regression model was obtained (α = 0.51, β = 0.81 and P<0.001). There is an acceptable correlation between the WISC-IV scales and CAS test in children with learning disorders. A concurrent validity is established between the two tests and their scales.

Concurrent Validity of Persian Version of Wechsler Intelligence Scale for Children - Fourth Edition and Cognitive Assessment System in Patients with Learning Disorder

PubMed Central

Rostami, Reza; Sadeghi, Vahid; Zarei, Jamileh; Haddadi, Parvaneh; Mohazzab-Torabi, Saman; Salamati, Payman

2013-01-01

Objective The aim of this study was to compare the Persian version of the wechsler intelligence scale for children - fourth edition (WISC-IV) and cognitive assessment system (CAS) tests, to determine the correlation between their scales and to evaluate the probable concurrent validity of these tests in patients with learning disorders. Methods One-hundered-sixty-two children with learning disorder who were presented at Atieh Comprehensive Psychiatry Center were selected in a consecutive non-randomized order. All of the patients were assessed based on WISC-IV and CAS scores questionnaires. Pearson correlation coefficient was used to analyze the correlation between the data and to assess the concurrent validity of the two tests. Linear regression was used for statistical modeling. The type one error was considered 5% in maximum. Findings There was a strong correlation between total score of WISC-IV test and total score of CAS test in the patients (r=0.75, P<0.001). The correlations among the other scales were mostly high and all of them were statistically significant (P<0.001). A linear regression model was obtained (α = 0.51, β = 0.81 and P<0.001). Conclusion There is an acceptable correlation between the WISC-IV scales and CAS test in children with learning disorders. A concurrent validity is established between the two tests and their scales. PMID:23724180

Expanding the occupational health methodology: A concatenated artificial neural network approach to model the burnout process in Chinese nurses.

PubMed

Ladstätter, Felix; Garrosa, Eva; Moreno-Jiménez, Bernardo; Ponsoda, Vicente; Reales Aviles, José Manuel; Dai, Junming

2016-01-01

Artificial neural networks are sophisticated modelling and prediction tools capable of extracting complex, non-linear relationships between predictor (input) and predicted (output) variables. This study explores this capacity by modelling non-linearities in the hardiness-modulated burnout process with a neural network. Specifically, two multi-layer feed-forward artificial neural networks are concatenated in an attempt to model the composite non-linear burnout process. Sensitivity analysis, a Monte Carlo-based global simulation technique, is then utilised to examine the first-order effects of the predictor variables on the burnout sub-dimensions and consequences. Results show that (1) this concatenated artificial neural network approach is feasible to model the burnout process, (2) sensitivity analysis is a prolific method to study the relative importance of predictor variables and (3) the relationships among variables involved in the development of burnout and its consequences are to different degrees non-linear. Many relationships among variables (e.g., stressors and strains) are not linear, yet researchers use linear methods such as Pearson correlation or linear regression to analyse these relationships. Artificial neural network analysis is an innovative method to analyse non-linear relationships and in combination with sensitivity analysis superior to linear methods.

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

Shape of Thyroid Cartilage Influences Outcome of Montgomery Medialization Thyroplasty: A Gender Issue.

PubMed

Desuter, Gauthier; Henrard, Sylvie; Van Lith-Bijl, Julie T; Amory, Avigaëlle; Duprez, Thierry; van Benthem, Peter Paul; Sjögren, Elisabeth

2017-03-01

This study aimed to determine whether the shape of the thyroid cartilage and gender influence voice outcomes after a Montgomery thyroplasty implant system (MTIS). A retrospective cohort study was performed on 20 consecutive patients who underwent MTIS. Voice outcome variables were the relative decrease in Voice Handicap Index (%) and the absolute increase in maximum phonation time (MPT) (in seconds). Material variables were the angle between the thyroid cartilage laminae (α-angle), the size of the prosthesis, and a combination of both (the α-ratio). Continuous variables were analyzed using medians and were compared between groups using the Mann-Whitney U test. Factors associated with the outcome variables were assessed by multivariable linear regression. A Pearson coefficient was calculated between material variables. The absolute increase in MPT between the pre- and postoperative period was significantly different between men and women, with a median absolute increase of 11.0 seconds for men and of 1.3 seconds for women (P < 0.001). A strong inverse correlation between the α-ratio and the absolute increase in MPT is observed in all patients, with a Pearson correlation coefficient R = -0.769 (P < 0.001). No factors were significantly associated with the relative Voice Handicap Index decrease in univariable or multivariable analyses. A better Pearson coefficient between the α-angle and the prosthesis size was found for females (0.8 vs 0.71). The MTIS is a good thyroplasty modality for male patients, but inadequate design of MTIS female implants leads to poor MPT outcomes. This represents a gender issue that needs to be further studied and eventually tackled. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

The Relationship Between Surface Curvature and Abdominal Aortic Aneurysm Wall Stress.

PubMed

de Galarreta, Sergio Ruiz; Cazón, Aitor; Antón, Raúl; Finol, Ender A

2017-08-01

The maximum diameter (MD) criterion is the most important factor when predicting risk of rupture of abdominal aortic aneurysms (AAAs). An elevated wall stress has also been linked to a high risk of aneurysm rupture, yet is an uncommon clinical practice to compute AAA wall stress. The purpose of this study is to assess whether other characteristics of the AAA geometry are statistically correlated with wall stress. Using in-house segmentation and meshing algorithms, 30 patient-specific AAA models were generated for finite element analysis (FEA). These models were subsequently used to estimate wall stress and maximum diameter and to evaluate the spatial distributions of wall thickness, cross-sectional diameter, mean curvature, and Gaussian curvature. Data analysis consisted of statistical correlations of the aforementioned geometry metrics with wall stress for the 30 AAA inner and outer wall surfaces. In addition, a linear regression analysis was performed with all the AAA wall surfaces to quantify the relationship of the geometric indices with wall stress. These analyses indicated that while all the geometry metrics have statistically significant correlations with wall stress, the local mean curvature (LMC) exhibits the highest average Pearson's correlation coefficient for both inner and outer wall surfaces. The linear regression analysis revealed coefficients of determination for the outer and inner wall surfaces of 0.712 and 0.516, respectively, with LMC having the largest effect on the linear regression equation with wall stress. This work underscores the importance of evaluating AAA mean wall curvature as a potential surrogate for wall stress.

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.

Are Predictive Equations for Estimating Resting Energy Expenditure Accurate in Asian Indian Male Weightlifters?

PubMed

Joseph, Mini; Gupta, Riddhi Das; Prema, L; Inbakumari, Mercy; Thomas, Nihal

2017-01-01

The accuracy of existing predictive equations to determine the resting energy expenditure (REE) of professional weightlifters remains scarcely studied. Our study aimed at assessing the REE of male Asian Indian weightlifters with indirect calorimetry and to compare the measured REE (mREE) with published equations. A new equation using potential anthropometric variables to predict REE was also evaluated. REE was measured on 30 male professional weightlifters aged between 17 and 28 years using indirect calorimetry and compared with the eight formulas predicted by Harris-Benedicts, Mifflin-St. Jeor, FAO/WHO/UNU, ICMR, Cunninghams, Owen, Katch-McArdle, and Nelson. Pearson correlation coefficient, intraclass correlation coefficient, and multiple linear regression analysis were carried out to study the agreement between the different methods, association with anthropometric variables, and to formulate a new prediction equation for this population. Pearson correlation coefficients between mREE and the anthropometric variables showed positive significance with suprailiac skinfold thickness, lean body mass (LBM), waist circumference, hip circumference, bone mineral mass, and body mass. All eight predictive equations underestimated the REE of the weightlifters when compared with the mREE. The highest mean difference was 636 kcal/day (Owen, 1986) and the lowest difference was 375 kcal/day (Cunninghams, 1980). Multiple linear regression done stepwise showed that LBM was the only significant determinant of REE in this group of sportspersons. A new equation using LBM as the independent variable for calculating REE was computed. REE for weightlifters = -164.065 + 0.039 (LBM) (confidence interval -1122.984, 794.854]. This new equation reduced the mean difference with mREE by 2.36 + 369.15 kcal/day (standard error = 67.40). The significant finding of this study was that all the prediction equations underestimated the REE. The LBM was the sole determinant of REE in this population. In the absence of indirect calorimetry, the REE equation developed by us using LBM is a better predictor for calculating REE of professional male weightlifters of this region.

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.

Linear and nonlinear market correlations: Characterizing financial crises and portfolio optimization.

PubMed

Haluszczynski, Alexander; Laut, Ingo; Modest, Heike; Räth, Christoph

2017-12-01

Pearson correlation and mutual information-based complex networks of the day-to-day returns of U.S. S&P500 stocks between 1985 and 2015 have been constructed to investigate the mutual dependencies of the stocks and their nature. We show that both networks detect qualitative differences especially during (recent) turbulent market periods, thus indicating strongly fluctuating interconnections between the stocks of different companies in changing economic environments. A measure for the strength of nonlinear dependencies is derived using surrogate data and leads to interesting observations during periods of financial market crises. In contrast to the expectation that dependencies reduce mainly to linear correlations during crises, we show that (at least in the 2008 crisis) nonlinear effects are significantly increasing. It turns out that the concept of centrality within a network could potentially be used as some kind of an early warning indicator for abnormal market behavior as we demonstrate with the example of the 2008 subprime mortgage crisis. Finally, we apply a Markowitz mean variance portfolio optimization and integrate the measure of nonlinear dependencies to scale the investment exposure. This leads to significant outperformance as compared to a fully invested portfolio.

Linear and nonlinear market correlations: Characterizing financial crises and portfolio optimization

NASA Astrophysics Data System (ADS)

Haluszczynski, Alexander; Laut, Ingo; Modest, Heike; Räth, Christoph

2017-12-01

Pearson correlation and mutual information-based complex networks of the day-to-day returns of U.S. S&P500 stocks between 1985 and 2015 have been constructed to investigate the mutual dependencies of the stocks and their nature. We show that both networks detect qualitative differences especially during (recent) turbulent market periods, thus indicating strongly fluctuating interconnections between the stocks of different companies in changing economic environments. A measure for the strength of nonlinear dependencies is derived using surrogate data and leads to interesting observations during periods of financial market crises. In contrast to the expectation that dependencies reduce mainly to linear correlations during crises, we show that (at least in the 2008 crisis) nonlinear effects are significantly increasing. It turns out that the concept of centrality within a network could potentially be used as some kind of an early warning indicator for abnormal market behavior as we demonstrate with the example of the 2008 subprime mortgage crisis. Finally, we apply a Markowitz mean variance portfolio optimization and integrate the measure of nonlinear dependencies to scale the investment exposure. This leads to significant outperformance as compared to a fully invested portfolio.

Associations between self-reported working conditions and registered health and safety results.

PubMed

Høivik, Dordi; Baste, Valborg; Brandsdal, Einar; Moen, Bente E

2007-02-01

To investigate the association between self-reported working conditions and registered health and safety results in a petroleum company in Norway. We analyzed data from company surveys of working and organizational conditions in 2003 and 2004 and data from the company's files of sickness absence, personal injuries, serious incidents, and undesirable incidents in 2003 and 2004 as well as personal injuries from 2000 to 2004 using Pearson's correlation analysis and multiple linear regression analyses. Good perception of confidence in management in 2003 and 2004 was significantly negatively correlated with the number of personal injuries from 2000 to 2004. Management style and trust in the manager are important factors for predicting personal injuries. The company's working and organizational survey might be used as an indicator for injury risk.

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.

Accuracy of MRI skeletal age estimation for subjects 12-19. Potential use for subjects of unknown age.

PubMed

Serinelli, Serenella; Panebianco, Valeria; Martino, Milvia; Battisti, Sofia; Rodacki, Karina; Marinelli, Enrico; Zaccagna, Fulvio; Semelka, Richard C; Tomei, Ernesto

2015-05-01

In forensic practice, there is a growing need for accurate methods of age estimation, especially in the cases of young individuals of unknown age. Age can be estimated through somatic features that are universally considered associated with chronological age. Unfortunately, these features do not always coincide with the real chronological age: for these reasons that age determination is often very difficult. Our aim is to evaluate accuracy of skeletal age estimation using Tomei's MRI method in subjects between 12 and 19 years old for forensic purposes. Two investigators analyzed MRI images of the left hand and wrist of 77 male and 74 female caucasian subjects, without chronic diseases or developmental disorders, whose age ranged from 12 to 19 years. Skeletal maturation was determined by two operators, who analyzed all MRI images separately, in blinded fashion to the chronological age. Inter-rater agreement was measured with Pearson (R (2)) coefficient. One of the examiners repeated the evaluation after 6 months, and intraobserver variation was analyzed. Bland-Altman plots were used to determine mean differences between skeletal and chronological age. Inter-rater agreement Pearson coefficient showed a good linear correlation, respectively, 0.98 and 0.97 in males and females. Bland-Altman analysis demonstrated that the differences between chronological and skeletal age are not significant. Spearman's correlation coefficient showed good correlation between skeletal and chronological age both in females (R (2) = 0.96) and in males (R (2) = 0.94). Our results show that MRI skeletal age is a reproducible method and has good correlation with chronological age.

Income inequality, disinvestment in health care and use of dental services.

PubMed

Bhandari, Bishal; Newton, Jonathan T; Bernabé, Eduardo

2015-01-01

To explore the interrelationships between income inequality, disinvestment in health care, and use of dental services at country level. This study pooled national estimates for use of dental services among adults aged 18 years or older from the 70 countries that participated in the World Health Survey from 2002 to 2004, together with aggregate data on national income (GDP per capita), income inequality (Gini coefficient), and disinvestment in health care (total health expenditure and dentist-to-population ratio) from various international sources. Use of dental services was defined as having had dental problems in the last 12 months and having received any treatment to address those needs. Associations between variables were explored using Pearson correlation coefficients and linear regression. Data from 63 countries representing the six WHO regions were analyzed. Use of dental services was negatively correlated with Gini coefficient (Pearson correlation coefficient -0.48, P < 0.001) and positively correlated with GDP per capita (0.40, P < 0.05), total health expenditure (0.45, P < 0.001), and dentist-to-population ratio (0.67, P < 0.001). The association between Gini coefficient and use of dental services was attenuated but remained significant after adjustments for GDP per capita, total health expenditure, and dentist-to-population ratio (regression coefficient -0.36; 95% CI -0.57, -0.15). This study shows an inverse relationship between income inequality and use of dental services. Of the two indicators of disinvestment in health care assessed, only dentist-to-population ratio was associated with income inequality and use of dental services. © 2014 American Association of Public Health Dentistry.

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.

Reliability and Validity of 2 Self-Report Measures to Assess Sedentary Behavior in Older Adults.

PubMed

Gennuso, Keith P; Matthews, Charles E; Colbert, Lisa H

2015-05-01

The purpose of this study was to examine the reliability and validity of 2 currently available physical activity surveys for assessing time spent in sedentary behavior (SB) in older adults. Fifty-eight adults (≥65 years) completed the Yale Physical Activity Survey for Older Adults (YPAS) and Community Health Activities Model Program for Seniors (CHAMPS) before and after a 10-day period during which they wore an ActiGraph accelerometer (ACC). Intraclass correlation coefficients (ICC) examined test-retest reliability. Overall percent agreement and a kappa statistic examined YPAS validity. Lin's concordance correlation, Pearson correlation, and Bland-Altman analysis examined CHAMPS validity. Both surveys had moderate test-retest reliability (ICC: YPAS = 0.59 (P < .001), CHAMPS = 0.64 (P < .001)) and significantly underestimated SB time. Agreement between YPAS and ACC was low (κ = -0.0003); however, there was a linear increase (P < .01) in ACC-derived SB time across YPAS response categories. There was poor agreement between ACC-derived SB and CHAMPS (Lin's r = .005; 95% CI, -0.010 to 0.020), and no linear trend across CHAMPS quartiles (P = .53). Neither of the surveys should be used as the sole measure of SB in a study; though the YPAS has the ability to rank individuals, providing it with some merit for use in correlational SB research.

[Correlation of age, IGF-1 serum levels, muscular mass index and their influence as determinants of isokinetic variables in patients with osteoporosis].

PubMed

Coronado-Zarco, Roberto; Diez-García, María del Pilar; Chávez-Arias, Daniel; León-Hernández, Saúl Renán; Cruz-Medina, Eva; Arellano-Hernández, Aurelia

2005-01-01

Bone and skeletal muscle mass loss is related to age. Mechanisms by which they interact have not been well established. To establish a relationship of age with serum levels of IGF-1, skeletal muscle and appendicular muscle mass index, and their influence in isokinetic parameters in osteoporotic female patients. Pearson correlation coefficient and linear regression analyses were used. There were 38 patients with a mean age of 65.16 years (range: 50-84 years), mean appendicular skeletal mass index (ASMI) of 6.3 kg/m2 (range: 4.3-8.3) and mean skeletal mass index (SMI) of 12.4 kg/m2 (range: 9.6-15.7), mean serum IGF-1 levels of 82.97 ng/ml (range: 22-177). Linear regression predicted hip mineral bone density by SMI (p = 0.19) and age (p = 0.017, r = 0.50). Some isokinetic parameters had a positive correlation for work with age. Knee acceleration time had a positive correlation with age. Osteoporosis and sarcopenia may have related pathophysiologic mechanisms. Growth factor study must include the influence of sex hormones. Some isokinetic parameters are determined by the predominant muscle fiber, skeletal mass index and age.

Cone-Beam Computed Tomography as a Diagnostic Method for Determination of Gingival Thickness and Distance between Gingival Margin and Bone Crest

PubMed Central

Borges, Germana Jayme; Ruiz, Luis Fernando Naldi; de Alencar, Ana Helena Gonçalves; Porto, Olavo César Lyra; Estrela, Carlos

2015-01-01

The objective of the present study was to assess cone-beam computed tomography (CBCT) as a diagnostic method for determination of gingival thickness (GT) and distance between gingival margin and vestibular (GMBC-V) and interproximal bone crests (GMBC-I). GT and GMBC-V were measured in 348 teeth and GMBC-I was measured in 377 tooth regions of 29 patients with gummy smile. GT was assessed using transgingival probing (TP), ultrasound (US), and CBCT, whereas GMBC-V and GMBC-I were assessed by transsurgical clinical evaluation (TCE) and CBCT. Statistical analyses used independent t-test, Pearson's correlation coefficient, and simple linear regression. Difference was observed for GT: between TP, CBCT, and US considering all teeth; between TP and CBCT and between TP and US in incisors and canines; between TP and US in premolars and first molars. TP presented the highest means for GT. Positive correlation and linear regression were observed between TP and CBCT, TP and US, and CBCT and US. Difference was observed for GMBC-V and GMBC-I using TCE and CBCT, considering all teeth. Correlation and linear regression results were significant for GMBC-V and GMBC-I in incisors, canines, and premolars. CBCT is an effective diagnostic method to visualize and measure GT, GMBC-V, and GMBC-I. PMID:25918737

Sirc-cvs cytotoxicity test: an alternative for predicting rodent acute systemic toxicity.

PubMed

Kitagaki, Masato; Wakuri, Shinobu; Hirota, Morihiko; Tanaka, Noriho; Itagaki, Hiroshi

2006-10-01

An in vitro crystal violet staining method using the rabbit cornea-derived cell line (SIRC-CVS) has been developed as an alternative to predict acute systemic toxicity in rodents. Seventy-nine chemicals, the in vitro cytotoxicity of which was already reported by the Multicenter Evaluation of In vitro Toxicity (MEIC) and ICCVAM/ECVAM, were selected as test compounds. The cells were incubated with the chemicals for 72 hrs and the IC(50) and IC(35) values (microg/mL) were obtained. The results were compared to the in vivo (rat or mouse) "most toxic" oral, intraperitoneal, subcutaneous and intravenous LD(50) values (mg/kg) taken from the RTECS database for each of the chemicals by using Pearson's correlation statistics. The following parameters were calculated: accuracy, sensitivity, specificity, prevalence, positive predictability, and negative predictability. Good linear correlations (Pearson's coefficient; r>0.6) were observed between either the IC(50) or the IC(35) values and all the LD(50) values. Among them, a statistically significant high correlation (r=0.8102, p<0.001) required for acute systemic toxicity prediction was obtained between the IC(50) values and the oral LD(50) values. By using the cut-off concentrations of 2,000 mg/kg (LD(50)) and 4,225 microg/mL (IC(50)), no false negatives were observed, and the accuracy was 84.8%. From this, it is concluded that this method could be used to predict the acute systemic toxicity potential of chemicals in rodents.

Predicting mortality rates: Comparison of an administrative predictive model (hospital standardized mortality ratio) with a physiological predictive model (Acute Physiology and Chronic Health Evaluation IV)--A cross-sectional study.

PubMed

Toua, Rene Elaine; de Kock, Jacques Erasmus; Welzel, Tyson

2016-02-01

Direct comparison of mortality rates has limited value because most deaths are due to the disease process. Predicting the risk of death accurately remains a challenge. A cross-sectional study compared the expected mortality rate as calculated with an administrative model to a physiological model, Acute Physiology and Chronic Health Evaluation IV. The combined cohort and stratified samples (<0.1, 0.1-0.5, or >0.5 predicted mortality) were considered. A total of 47,982 patients were scored from 1 July 2013 to 30 June 2014, and 46,061 records were included in the analysis. A moderate correlation was shown for the combined cohort (Pearson correlation index, 0.618; 95% confidence interval [CI], 0.380-0.779; R(2) = 0.38). A very good correlation for the less than 10% stratum (Pearson correlation index, 0.884; R(2) = 0.78; 95% CI, 0.79-0.937) and a moderate correlation for 0.1 to 0.5 predicted mortality rates (Pearson correlation index, 0.782; R(2) = 0.61; 95% CI, 0.623-0.879). There was no significant positive correlation for the greater than 50% predicted mortality stratum (Pearson correlation index, 0.087; R(2) = 0.007; 95% CI, -0.23 to 0.387). At less than 0.1, the models are interchangeable, but in spite of a moderate correlation, greater than 0.1 hospital standardized mortality ratio cannot be used to predict mortality. Copyright © 2015 Elsevier Inc. All rights reserved.

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-stage PAD. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

The association between clinical parameters and glaucoma-specific quality of life in Chinese primary open-angle glaucoma patients.

PubMed

Lee, Jacky W Y; Chan, Catherine W S; Chan, Jonathan C H; Li, Q; Lai, Jimmy S M

2014-08-01

OBJECTIVE. To investigate the association between clinical measurements and glaucoma-specific quality of life in Chinese glaucoma patients. DESIGN. Cross-sectional study. SETTING. An academic hospital in Hong Kong. PATIENTS. A Chinese translation of the Glaucoma Quality of Life-15 questionnaire was completed by 51 consecutive patients with bilateral primary open-angle glaucoma. The binocular means of several clinical measurements were correlated with Glaucoma Quality of Life-15 findings using Pearson's correlation coefficient and linear regression. The measurements were the visual field index and pattern standard deviation from the Humphrey Field Analyzer, Snellen best-corrected visual acuity, presenting intra-ocular pressure, current intra-ocular pressure, average retinal nerve fibre layer thickness via optical coherence tomography, and the number of topical anti-glaucoma medications being used. RESULTS. In these patients, there was a significant correlation and linear relationship between a poorer Glaucoma Quality of Life-15 score and a lower visual field index (r=0.3, r(2)=0.1, P=0.01) and visual acuity (r=0.3, r(2)=0.1, P=0.03). A thinner retinal nerve fibre layer also correlated with a poorer Glaucoma Quality of Life-15 score, but did not attain statistical significance (r=0.3, P=0.07). There were no statistically significant correlations for the other clinical parameters with the Glaucoma Quality of Life-15 scores (all P values being >0.7). The three most problematic activities affecting quality of life were "adjusting to bright lights", "going from a light to a dark room or vice versa", and "seeing at night". CONCLUSION. For Chinese primary open-angle glaucoma patients, binocular visual field index and visual acuity correlated linearly with glaucoma-specific quality of life, and activities involving dark adaptation were the most problematic.

Data mining graphene: Correlative analysis of structure and electronic degrees of freedom in graphenic monolayers with defects

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

Ziatdinov, Maxim A.; Fujii, Shintaro; Kiguchi, Manabu

The link between changes in the material crystal structure and its mechanical, electronic, magnetic, and optical functionalities known as the structure-property relationship is the cornerstone of the contemporary materials science research. The recent advances in scanning transmission electron and scanning probe microscopies (STEM and SPM) have opened an unprecedented path towards examining the materials structure property relationships on the single-impurity and atomic-configuration levels. Lacking, however, are the statistics-based approaches for cross-correlation of structure and property variables obtained in different information channels of the STEM and SPM experiments. Here we have designed an approach based on a combination of sliding windowmore » Fast Fourier Transform, Pearson correlation matrix, linear and kernel canonical correlation, to study a relationship between lattice distortions and electron scattering from the SPM data on graphene with defects. Our analysis revealed that the strength of coupling to strain is altered between different scattering channels which can explain coexistence of several quasiparticle interference patterns in the nanoscale regions of interest. In addition, the application of the kernel functions allowed us extracting a non-linear component of the relationship between the lattice strain and scattering intensity in graphene. Lastly, the outlined approach can be further utilized to analyzing correlations in various multi-modal imaging techniques where the information of interest is spatially distributed and has usually a complex multidimensional nature.« less

Data mining graphene: Correlative analysis of structure and electronic degrees of freedom in graphenic monolayers with defects

DOE PAGES

Ziatdinov, Maxim A.; Fujii, Shintaro; Kiguchi, Manabu; ...

2016-11-09

The link between changes in the material crystal structure and its mechanical, electronic, magnetic, and optical functionalities known as the structure-property relationship is the cornerstone of the contemporary materials science research. The recent advances in scanning transmission electron and scanning probe microscopies (STEM and SPM) have opened an unprecedented path towards examining the materials structure property relationships on the single-impurity and atomic-configuration levels. Lacking, however, are the statistics-based approaches for cross-correlation of structure and property variables obtained in different information channels of the STEM and SPM experiments. Here we have designed an approach based on a combination of sliding windowmore » Fast Fourier Transform, Pearson correlation matrix, linear and kernel canonical correlation, to study a relationship between lattice distortions and electron scattering from the SPM data on graphene with defects. Our analysis revealed that the strength of coupling to strain is altered between different scattering channels which can explain coexistence of several quasiparticle interference patterns in the nanoscale regions of interest. In addition, the application of the kernel functions allowed us extracting a non-linear component of the relationship between the lattice strain and scattering intensity in graphene. Lastly, the outlined approach can be further utilized to analyzing correlations in various multi-modal imaging techniques where the information of interest is spatially distributed and has usually a complex multidimensional nature.« less

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 which simulate the climate system. The method is applied to model data from the high resolution ocean model, INALT01 where the relationship between the Agulhas Leakage and the North Brazil Current is evaluated. Preliminary results show significant correlation between the two variables when there is 10 year lag between them, which is more or less the time that takes the Agulhas Leakage water to reach the North Brazil Current. Mudelsee, M., 2003. Estimating Pearson's correlation coefficient with bootstrap confidence interval from serially dependent time series. Mathematical Geology 35, 651-665.

Use of bedside ultrasound to assess degree of dehydration in children with gastroenteritis.

PubMed

Chen, Lei; Hsiao, Allen; Langhan, Melissa; Riera, Antonio; Santucci, Karen A

2010-10-01

Prospectively identifying children with significant dehydration from gastroenteritis is difficult in acute care settings. Previous work by our group has shown that bedside ultrasound (US) measurement of the inferior vena cava (IVC) and the aorta (Ao) diameter ratio is correlated with intravascular volume. This study was designed to validate the use of this method in the prospective identification of children with dehydration by investigating whether the IVC/Ao ratio correlated with dehydration in children with acute gastroenteritis. Another objective was to investigate the interrater reliability of the IVC/Ao measurements. A prospective observational study was carried out in a pediatric emergency department (PED) between November 2007 and June 2009. Children with acute gastroenteritis were enrolled as subjects. A pair of investigators obtained transverse images of the IVC and Ao using bedside US. The ratio of IVC and Ao diameters (IVC/Ao) was calculated. Subjects were asked to return after resolution of symptoms. The difference between the convalescent weight and ill weight was used to calculate the degree of dehydration. Greater than or equal to 5% difference was judged to be significant. Linear regression was performed with dehydration as the dependent variable and the IVC/Ao as the independent variable. Pearson's correlation coefficient was calculated to assess the degree of agreement between observers. A total of 112 subjects were enrolled. Seventy-one subjects (63%) completed follow-up. Twenty-eight subjects (39%) had significant dehydration. The linear regression model resulted in an R² value of 0.21 (p < 0.001) and a slope (B) of 0.11 (95% confidence interval [CI] = 0.08 to 0.14). An IVC/Ao cutoff of 0.8 produced a sensitivity of 86% and a specificity of 56% for the diagnosis of significant dehydration. Forty-eight paired measurements of IVC/Ao ratios were made. The Pearson correlation coefficient was 0.76.   In this pilot study the ratio of IVC to Ao diameters, as measured by bedside US, was a marginally accurate measurement of acute weight loss in children with dehydration from gastroenteritis. The technique demonstrated good interrater reliability. © 2010 by the Society for Academic Emergency Medicine.

Nonparametric regression applied to quantitative structure-activity relationships

PubMed

Constans; Hirst

2000-03-01

Several nonparametric regressors have been applied to modeling quantitative structure-activity relationship (QSAR) data. The simplest regressor, the Nadaraya-Watson, was assessed in a genuine multivariate setting. Other regressors, the local linear and the shifted Nadaraya-Watson, were implemented within additive models--a computationally more expedient approach, better suited for low-density designs. Performances were benchmarked against the nonlinear method of smoothing splines. A linear reference point was provided by multilinear regression (MLR). Variable selection was explored using systematic combinations of different variables and combinations of principal components. For the data set examined, 47 inhibitors of dopamine beta-hydroxylase, the additive nonparametric regressors have greater predictive accuracy (as measured by the mean absolute error of the predictions or the Pearson correlation in cross-validation trails) than MLR. The use of principal components did not improve the performance of the nonparametric regressors over use of the original descriptors, since the original descriptors are not strongly correlated. It remains to be seen if the nonparametric regressors can be successfully coupled with better variable selection and dimensionality reduction in the context of high-dimensional QSARs.

Prediction of maize phenotype based on whole-genome single nucleotide polymorphisms using deep belief networks

NASA Astrophysics Data System (ADS)

Rachmatia, H.; Kusuma, W. A.; Hasibuan, L. S.

2017-05-01

Selection in plant breeding could be more effective and more efficient if it is based on genomic data. Genomic selection (GS) is a new approach for plant-breeding selection that exploits genomic data through a mechanism called genomic prediction (GP). Most of GP models used linear methods that ignore effects of interaction among genes and effects of higher order nonlinearities. Deep belief network (DBN), one of the architectural in deep learning methods, is able to model data in high level of abstraction that involves nonlinearities effects of the data. This study implemented DBN for developing a GP model utilizing whole-genome Single Nucleotide Polymorphisms (SNPs) as data for training and testing. The case study was a set of traits in maize. The maize dataset was acquisitioned from CIMMYT’s (International Maize and Wheat Improvement Center) Global Maize program. Based on Pearson correlation, DBN is outperformed than other methods, kernel Hilbert space (RKHS) regression, Bayesian LASSO (BL), best linear unbiased predictor (BLUP), in case allegedly non-additive traits. DBN achieves correlation of 0.579 within -1 to 1 range.

Teaching High School Students Machine Learning Algorithms to Analyze Flood Risk Factors in River Deltas

NASA Astrophysics Data System (ADS)

Rose, R.; Aizenman, H.; Mei, E.; Choudhury, N.

2013-12-01

High School students interested in the STEM fields benefit most when actively participating, so I created a series of learning modules on how to analyze complex systems using machine-learning that give automated feedback to students. The automated feedbacks give timely responses that will encourage the students to continue testing and enhancing their programs. I have designed my modules to take the tactical learning approach in conveying the concepts behind correlation, linear regression, and vector distance based classification and clustering. On successful completion of these modules, students will learn how to calculate linear regression, Pearson's correlation, and apply classification and clustering techniques to a dataset. Working on these modules will allow the students to take back to the classroom what they've learned and then apply it to the Earth Science curriculum. During my research this summer, we applied these lessons to analyzing river deltas; we looked at trends in the different variables over time, looked for similarities in NDVI, precipitation, inundation, runoff and discharge, and attempted to predict floods based on the precipitation, waves mean, area of discharge, NDVI, and inundation.

Gender and Age Analyses of NIRS/STAI Pearson Correlation Coefficients at Resting State.

PubMed

Matsumoto, T; Fuchita, Y; Ichikawa, K; Fukuda, Y; Takemura, N; Sakatani, K

2016-01-01

According to the valence asymmetry hypothesis, the left/right asymmetry of PFC activity is correlated with specific emotional responses to mental stress and personality traits. In a previous study we measured spontaneous oscillation of oxy-Hb concentrations in the bilateral PFC at rest in normal adults employing two-channel portable NIRS and computed the laterality index at rest (LIR). We investigated the Pearson correlation coefficient between the LIR and anxiety levels evaluated by the State-Trait Anxiety Inventory (STAI) test. We found that subjects with right-dominant activity at rest showed higher STAI scores, while those with left dominant oxy-Hb changes at rest showed lower STAI scores such that the Pearson correlation coefficient between LIR and STAI was positive. This study performed Bootstrap analysis on the data and showed the following statistics of the target correlation coefficient: mean=0.4925 and lower confidence limit=0.177 with confidence level 0.05. Using the KS-test, we demonstrated that the correlation did not depend on age, whereas it did depend on gender.

Characterization and first flush analysis in road and roof runoff in Shenyang, China.

PubMed

Li, Chunlin; Liu, Miao; Hu, Yuanman; Gong, Jiping; Sun, Fengyun; Xu, Yanyan

2014-01-01

As urbanization increases, urban runoff is an increasingly important component of total urban non-point source pollution. In this study, the properties of urban runoff were examined in Shenyang, in northeastern China. Runoff samples from a tiled roof, a concrete roof and a main road were analyzed for key pollutants (total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), Pb, Cd, Cr, Cu, Ni, and Zn). The event mean concentration, site mean concentration, M(V) curves (dimensionless cumulative curve of pollutant load with runoff volume), and mass first flush ratio (MFF30) were used to analyze the characteristics of pollutant discharge and first flush (FF) effect. For all events, the pollutant concentration peaks occurred in the first half-hour after the runoff appeared and preceded the flow peaks. TN is the main pollutant in roof runoff. TSS, TN, TP, Pb, and Cr are the main pollutants in road runoff in Shenyang. There was a significant correlation between TSS and other pollutants except TN in runoff, which illustrated that TSS was an important carrier of organic matter and heavy metals. TN had strong positive correlations with total rainfall (Pearson's r = 0.927), average rainfall (Pearson's r = 0.995), and maximum rainfall intensity (Pearson's r = 0.991). TP had a strong correlation with rainfall intensity (Pearson's r = 0.940). A significant positive correlation between COD and rainfall duration (Pearson's r = 0.902, significance level = 0.05) was found. The order of FF intensity in different surfaces was concrete roof > tile roof > road. Rainfall duration and the length of the antecedent dry period were positively correlated with the FF. TN tended to exhibit strong flush for some events. Heavy metals showed a substantially stronger FF than other pollutant.

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.

Correlation of the National Board of Medical Examiners Emergency Medicine Advanced Clinical Examination Given in July to Intern American Board of Emergency Medicine in-training Examination Scores: A Predictor of Performance?

PubMed

Hiller, Katherine; Franzen, Doug; Heitz, Corey; Emery, Matthew; Poznanski, Stacy

2015-11-01

There is great variation in the knowledge base of Emergency Medicine (EM) interns in July. The first objective knowledge assessment during residency does not occur until eight months later, in February, when the American Board of EM (ABEM) administers the in-training examination (ITE). In 2013, the National Board of Medical Examiners (NBME) released the EM Advanced Clinical Examination (EM-ACE), an assessment intended for fourth-year medical students. Administration of the EM-ACE to interns at the start of residency may provide an earlier opportunity to assess the new EM residents' knowledge base. The primary objective of this study was to determine the correlation of the NBME EM-ACE, given early in residency, with the EM ITE. Secondary objectives included determination of the correlation of the United States Medical Licensing Examination (USMLE) Step 1 or 2 scores with early intern EM-ACE and ITE scores and the effect, if any, of clinical EM experience on examination correlation. This was a multi-institutional, observational study. Entering EM interns at six residencies took the EM-ACE in July 2013 and the ABEM ITE in February 2014. We collected scores for the EM-ACE and ITE, age, gender, weeks of clinical EM experience in residency prior to the ITE, and USMLE Step 1 and 2 scores. Pearson's correlation and linear regression were performed. Sixty-two interns took the EM-ACE and the ITE. The Pearson's correlation coefficient between the ITE and the EM-ACE was 0.62. R-squared was 0.5 (adjusted 0.4). The coefficient of determination was 0.41 (95% CI [0.3-0.8]). For every increase of one in the scaled EM-ACE score, we observed a 0.4% increase in the EM in-training score. In a linear regression model using all available variables (EM-ACE, gender, age, clinical exposure to EM, and USMLE Step 1 and Step 2 scores), only the EM-ACE score was significantly associated with the ITE (p<0.05). We observed significant colinearity among the EM-ACE, ITE and USMLE scores. Gender, age and number of weeks of EM prior to the ITE had no effect on the relationship between EM-ACE and the ITE. Given early during intern year, the EM-ACE score showed positive correlation with ITE. Clinical EM experience prior to the in-training exam did not affect the correlation.

Cross-cultural adaptation and validation of als Functional Rating Scale-Revised in Portuguese language.

PubMed

Guedes, Keyte; Pereira, Cecília; Pavan, Karina; Valério, Berenice Cataldo Oliveira

2010-02-01

The aim of this study is the cross-cultural, as well as to validate in Portuguese language the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R). We performed a prospective study of individuals with amyotrophic lateral sclerosis (ALS) clinically defined. The scale, after obtaining the final version in Portuguese, was administered in 22 individuals and three weeks after re-applied. There were no significant differences between the application and reapplication of the scale (p=0.069). The linear regression and internal consistency measured by Pearson correlation and alpha Conbrach were significant with r=0.975 e alpha=0.934. The reliability test-retest demonstrated by intraclass correlation coefficient was strong with ICC=0.975. Therefore, this version proved to be applicable, reliable and easy to be conducted in clinical practice and research.

Health Service Quality Scale: Brazilian Portuguese translation, reliability and validity.

PubMed

Rocha, Luiz Roberto Martins; Veiga, Daniela Francescato; e Oliveira, Paulo Rocha; Song, Elaine Horibe; Ferreira, Lydia Masako

2013-01-17

The Health Service Quality Scale is a multidimensional hierarchical scale that is based on interdisciplinary approach. This instrument was specifically created for measuring health service quality based on marketing and health care concepts. The aim of this study was to translate and culturally adapt the Health Service Quality Scale into Brazilian Portuguese and to assess the validity and reliability of the Brazilian Portuguese version of the instrument. We conducted a cross-sectional, observational study, with public health system patients in a Brazilian university hospital. Validity was assessed using Pearson's correlation coefficient to measure the strength of the association between the Brazilian Portuguese version of the instrument and the SERVQUAL scale. Internal consistency was evaluated using Cronbach's alpha coefficient; the intraclass (ICC) and Pearson's correlation coefficients were used for test-retest reliability. One hundred and sixteen consecutive postoperative patients completed the questionnaire. Pearson's correlation coefficient for validity was 0.20. Cronbach's alpha for the first and second administrations of the final version of the instrument were 0.982 and 0.986, respectively. For test-retest reliability, Pearson's correlation coefficient was 0.89 and ICC was 0.90. The culturally adapted, Brazilian Portuguese version of the Health Service Quality Scale is a valid and reliable instrument to measure health service quality.

Loneliness and depression among the elderly in an agricultural settlement: mediating effects of social support.

PubMed

Wan Mohd Azam, Wan Mohd Yunus; Din, Normah Che; Ahmad, Mahadir; Ghazali, Shazli Ezzat; Ibrahim, Norhayati; Said, Zaini; Ghazali, Ahmad Rohi; Shahar, Suzana; Razali, Rosdinom; Maniam, T

2013-04-01

Loneliness has long been known to have strong association with depression. The relationship between loneliness and depression, however, has been associated with other risk factors including social support. The aim of this paper is to describe the role of social support in the association between loneliness and depression. This cross-sectional study examined the mediating effects of social support among 161 community-based elderly in agricultural settlement of a rural area in Sungai Tengi, Malaysia. Subjects were investigated with De Jong Gierveld Loneliness Scale, Geriatric Depression Scale and Medical Outcome Survey Social Support Survey. Data were analyzed using Pearson correlation, linear and hierarchical regression. Results indicated that social support partially mediated the relationship between loneliness and depression. This suggests that social support affects the linear association between loneliness and depression in the elderly. Copyright © 2013 Wiley Publishing Asia Pty Ltd.

Complex messages regarding a thin ideal appearing in teenage girls' magazines from 1956 to 2005.

PubMed

Luff, Gina M; Gray, James J

2009-03-01

Seventeen and YM were assessed from 1956 through 2005 (n=312) to examine changes in the messages about thinness sent to teenage women. Trends were analyzed through an investigation of written, internal content focused on dieting, exercise, or both, while cover models were examined to explore fluctuations in body size. Pearson's Product correlations and weighted-least squares linear regression models were used to demonstrate changes over time. The frequency of written content related to exercise and combined plans increased in Seventeen, while a curvilinear relationship between time and content relating to dieting appeared. YM showed a linear increase in content related to dieting, exercise, and combined plans. Average cover model body size increased over time in YM while demonstrating no significant changes in Seventeen. Overall, more written messages about dieting and exercise appeared in teen's magazines in 2005 than before while the average cover model body size increased.

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.

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.

Short communication: using infrared thermography as an in situ measure of core body temperature in lot-fed Angus steers

NASA Astrophysics Data System (ADS)

Lees, Angela M.; Lees, J. C.; Sejian, V.; Wallage, A. L.; Gaughan, J. B.

2018-01-01

Thirty-six Black Angus steers were used in a replicated study; three replicates of 12 steers/replicate. Steers had an initial non-fasted BW of 392.3 ± 5.1, 427.5 ± 6.3, and 392.7 ± 3.7 kg for each replicate, respectively. Steers were housed outside in individual animal pens (10 m × 3.4 m). Each replicate was conducted over a 6-day period where infrared thermography (IRT) images were collected at 3-h intervals, commencing at 0600 h on day 1 and concluding at 0600 h on day 6. Rumen temperatures ( T RUM) were measured at 10-min intervals for the duration of each replicate using a radio-frequency identification (RFID) rumen bolus. These data were used to determine the relationship with surface temperature of the cattle, which was determined using IRT. Individual T RUM were converted to an hourly average. The relationship between T RUM and surface temperature was determined using Pearson's correlation coefficient. There were no linear trends between mean hourly T RUM and mean surface temperature. Pearson's correlation coefficient indicated that there were weak associations ( r ≤ 0.1; P < 0.003) between T RUM and body surface temperature. These data suggest that there was little relationship between the surface temperature and T RUM.

Photogrammetric Correlation of Face with Frontal Radiographs and Direct Measurements.

PubMed

Negi, Gunjan; Ponnada, Swaroopa; Aravind, N K S; Chitra, Prasad

2017-05-01

Photogrammetry is a science of making measurements from photographs. As cephalometric analysis till date has focused mainly on skeletal relationships, photogrammetry may provide a means to reliably assess and compare soft tissue and hard tissue measurements. To compare and correlate linear measurements taken directly from subject's faces and from standardized frontal cephalometric radiographs and to correlate them with standardized frontal facial photographs of Indian population and to obtain mean values. A cross-sectional study was conducted on 30 subjects of Indian origin. Frontal cephalograms and standardized frontal photographs were obtained from subjects in the age group of 18- 25 years. Vernier calipers were used to obtain facial measurements directly. Photographs and radiographs were uploaded and measured using Nemoceph software. Analogous cephalometric, photographic and direct measurements were compared by one-way ANOVA to assess Pearson correlation coefficients for 12 linear measurements (6 vertical, 6 horizontal). Bonferroni post-hoc test was done for pair wise comparison. Among all measurements used, O R -O L (orbitale right-orbitale left) showed a high correlation r = 0.76, 0.70, 0.71. There was moderate correlation with En R -En L (endocanthion rt - endocanthion lt) r 2 = 0.62, 0.68, 0.68. Highly significant correlation was evident with N-Sn, En R -En L and Ag R -Ag L with p<0.001. A statistically significant correlation was found between photographic, radiographic and direct measurements. Therefore, photogrammetry has proven to be an alternative diagnostic tool that can be used in epidemiologic studies when there is a need for a simple, basic, non-invasive and cost-effective method.

Systolic blood pressure but not electrocardiogram QRS duration is associated with heart rate variability (HRV): a cross-sectional study in rural Australian non-diabetics.

PubMed

Lee, Yvonne Yin Leng; Jelinek, Herbert F; McLachlan, Craig S

2017-01-01

A positive correlation between ECG derived QRS duration and heart rate variability (HRV) parameters had previously been reported in young healthy adults. We note this study used a narrow QRS duration range, and did not adjust for systolic blood pressure. Our aims are to investigate associations between systolic blood pressure (SBP), QRS duration and HRV in a rural aging population. A retrospective cross sectional population was obtained from the CSU Diabetes Screening Research Initiative data base where 200 participants had no diabetes or pre-diabetes. SBP data were matched with ECG derived QRS duration and HRV parameters. HRV parameters were calculated from R-R intervals. Resting 12-lead electrocardiograms were obtained from each subject using a Welch Allyn PC-Based ECG system. Pearson correlation analysis revealed no statistically significant associations between HRV parameters and QRS duration. No significant mean differences in HRV parameter subgroups across defined QRS cut-offs were found. SBP > 146 mmHg was associated with increasing QRS durations, however this association disappeared once models were adjusted for age and gender. SBP was also significantly associated with a number of HRV parameters using Pearson correlation analysis, including high frequency (HF) ( p  < 0.05), HFln ( p  < 0.02), RMSDD ( p  < 0.02) and non-linear parameters; ApEN ( p  < 0.001) were negatively correlated with increasing SBP while the low frequency to high frequency ratio (LF/HF) increased with increasing SBP ( p  < 0.03). Our results do not support associations between ECG derived R-R derived HRV parameters and QRS duration in aging populations. We suggest that ventricular conduction as determined by QRS duration is independent of variations in SA-node heart rate variability.

Reference Clinical Database for Fixation Stability Metrics in Normal Subjects Measured with the MAIA Microperimeter.

PubMed

Morales, Marco U; Saker, Saker; Wilde, Craig; Pellizzari, Carlo; Pallikaris, Aristophanes; Notaroberto, Neil; Rubinstein, Martin; Rui, Chiara; Limoli, Paolo; Smolek, Michael K; Amoaku, Winfried M

2016-11-01

The purpose of this study was to establish a normal reference database for fixation stability measured with the bivariate contour ellipse area (BCEA) in the Macular Integrity Assessment (MAIA) microperimeter. Subjects were 358 healthy volunteers who had the MAIA examination. Fixation stability was assessed using two BCEA fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2). Statistical analysis was performed with linear regression and Pearson's product moment correlation coefficient. Average areas of 0.80 deg 2 (min = 0.03, max = 3.90, SD = 0.68) for the index BCEA@63% and 2.40 deg 2 (min = 0.20, max = 11.70, SD = 2.04) for the index BCEA@95% were found. The average values of P1 and P2 were 95% (min = 76, max = 100, SD = 5.31) and 99% (min = 91, max = 100, SD = 1.42), respectively. The Pearson's product moment test showed an almost perfect correlation index, r = 0.999, between BCEA@63% and BCEA@95%. Index P1 showed a very strong correlation with BCEA@63%, r = -0.924, as well as with BCEA@95%, r = -0.925. Index P2 demonstrated a slightly lower correlation with both BCEA@63% and BCEA@95%, r = -0.874 and -0.875, respectively. The single parameter of the BCEA@95% may be taken as accurately reporting fixation stability and serves as a reference database of normal subjects with a cutoff area of 2.40 ± 2.04 deg 2 in MAIA microperimeter. Fixation stability can be measured with different indices. This study originates reference fixation values for the MAIA using a single fixation index.

Comparison of the goals and MISTELS scores for the evaluation of surgeons on training benches.

PubMed

Wolf, Rémi; Medici, Maud; Fiard, Gaëlle; Long, Jean-Alexandre; Moreau-Gaudry, Alexandre; Cinquin, Philippe; Voros, Sandrine

2018-01-01

Evaluation of surgical technical abilities is a major issue in minimally invasive surgery. Devices such as training benches offer specific scores to evaluate surgeons but cannot transfer in the operating room (OR). A contrario, several scores measure performance in the OR, but have not been evaluated on training benches. Our aim was to demonstrate that the GOALS score, which can effectively grade in the OR the abilities involved in laparoscopy, can be used for evaluation on a laparoscopic testbench (MISTELS). This could lead to training systems that can identify more precisely the skills that have been acquired or must still be worked on. 32 volunteers (surgeons, residents and medical students) performed the 5 tasks of the MISTELS training bench and were simultaneously video-recorded. Their performance was evaluated with the MISTELS score and with the GOALS score based on the review of the recording by two experienced, blinded laparoscopic surgeons. The concurrent validity of the GOALS score was assessed using Pearson and Spearman correlation coefficients with the MISTELS score. The construct validity of the GOALS score was assessed with k-means clustering and accuracy rates. Lastly, abilities explored by each MISTELS task were identified with multiple linear regression. GOALS and MISTELS scores are strongly correlated (Pearson correlation coefficient = 0.85 and Spearman correlation coefficient = 0.82 for the overall score). The GOALS score proves to be valid for construction for the tasks of the training bench, with a better accuracy rate between groups of level after k-means clustering, when compared to the original MISTELS score (accuracy rates, respectively, 0.75 and 0.56). GOALS score is well suited for the evaluation of the performance of surgeons of different levels during the completion of the tasks of the MISTELS training bench.

The association of endothelial function and tone by digital arterial tonometry with MRI left ventricular mass in African Americans: the Jackson Heart Study.

PubMed

Tripathi, Avnish; Benjamin, Emelia J; Musani, Solomon K; Hamburg, Naomi M; Tsao, Connie W; Saraswat, Arti; Vasan, Ramachandran S; Mitchell, Gary F; Fox, Ervin R

2017-05-01

Peripheral vascular endothelial dysfunction assessed by digital peripheral arterial tonometry (PAT) has been associated with risk for adverse cardiovascular events. We examined the relations of peripheral microvascular dysfunction and left ventricular mass in a community-based cohort of African Americans. We examined participants of the Jackson Heart Study who had PAT and cardiac magnetic resonance imaging evaluations between 2007 and 2013. Consistent with pertinent literature, left ventricular mass index (LVMI) was adjusted for body size by indexing to height 2.7 . Pearson's correlation and general linear regression analyses were used to relate reactive hyperemia index, baseline pulse amplitude (BPA), and augmentation index (markers of microvascular vasodilator function, baseline vascular pulsatility, and relative wave reflection, respectively) to LVMI after adjusting for traditional cardiovascular risk factors. A total of 440 participants (mean age 59 ± 10 years, 60% women) were included. Age- and sex-adjusted Pearson's correlation analysis suggested that natural log transformed LVMI was negatively correlated with reactive hyperemia index (coefficient: -0.114; P = .02) and positively correlated with BPA (coefficient: 0.272; P < .001). In multivariable analyses, higher log e LVMI was associated with higher BPA (β: 0.210; P = .03) after accounting for age, sex, body mass index, diabetes, hypertension, ratio of total cholesterol and high-density lipoprotein cholesterol, smoking, and history of cardiovascular disease. In a community-based sample of African Americans, higher baseline pulsatility measured by PAT was associated with higher LVMI by cardiac magnetic resonance imaging after adjusting for traditional risk factors. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Regional gray matter atrophy in relapsing remitting multiple sclerosis: baseline analysis of multi-center data.

PubMed

Datta, Sushmita; Staewen, Terrell D; Cofield, Stacy S; Cutter, Gary R; Lublin, Fred D; Wolinsky, Jerry S; Narayana, Ponnada A

2015-03-01

Regional gray matter (GM) atrophy in multiple sclerosis (MS) at disease onset and its temporal variation can provide objective information regarding disease evolution. An automated pipeline for estimating atrophy of various GM structures was developed using tensor based morphometry (TBM) and implemented on a multi-center sub-cohort of 1008 relapsing remitting MS (RRMS) patients enrolled in a Phase 3 clinical trial. Four hundred age and gender matched healthy controls were used for comparison. Using the analysis of covariance, atrophy differences between MS patients and healthy controls were assessed on a voxel-by-voxel analysis. Regional GM atrophy was observed in a number of deep GM structures that included thalamus, caudate nucleus, putamen, and cortical GM regions. General linear regression analysis was performed to analyze the effects of age, gender, and scanner field strength, and imaging sequence on the regional atrophy. Correlations between regional GM volumes and expanded disability status scale (EDSS) scores, disease duration (DD), T2 lesion load (T2 LL), T1 lesion load (T1 LL), and normalized cerebrospinal fluid (nCSF) were analyzed using Pearson׳s correlation coefficient. Thalamic atrophy observed in MS patients compared to healthy controls remained consistent within subgroups based on gender and scanner field strength. Weak correlations between thalamic volume and EDSS (r=-0.133; p<0.001) and DD (r=-0.098; p=0.003) were observed. Of all the structures, thalamic volume moderately correlated with T2 LL (r=-0.492; P-value<0.001), T1 LL (r=-0.473; P-value<0.001) and nCSF (r=-0.367; P-value<0.001). Copyright © 2015 Elsevier B.V. All rights reserved.

Correlation between Visual Field Index and Other Functional and Structural Measures in Glaucoma Patients and Suspects.

PubMed

Iutaka, Natalia A; Grochowski, Rubens A; Kasahara, Niro

2017-01-01

To evaluate the correlation between visual field index (VFI) and both structural and functional measures of the optic disc in primary open angle glaucoma patients and suspects. In this retrospective study, 162 glaucoma patients and suspects underwent standard automated perimetry (SAP), retinography, and retinal nerve fiber layer (RNFL) measurement. The optic disc was stratified according to the vertical cup/disc ratio (C/D) and sorted by the disc damage likelihood scale (DDLS). RNFL was measured with the optical coherence tomography. The VFI perimetry was correlated with the mean deviation (MD) and pattern standard deviation (PSD) obtained by SAP, and structural parameters by Pearson's correlation coefficients. VFI displayed strong correlation with MD ( R = 0.959) and PSD ( R = -0.744). The linear correlations between VFI and structural measures including C/D ( R = -0.179, P = 0.012), DDLS ( R = -0.214, P = 0.006), and RNFL ( R = 0.416, P < 0.001) were weak but statistically significant. VFI showed a strong correlation with MD and PSD but demonstrated a weak correlation with structural measures. It can possibly be used as a marker for functional impairment severity in patients with glaucoma.

Robust correlation analyses: false positive and power validation using a new open source matlab toolbox.

PubMed

Pernet, Cyril R; Wilcox, Rand; Rousselet, Guillaume A

2012-01-01

Pearson's correlation measures the strength of the association between two variables. The technique is, however, restricted to linear associations and is overly sensitive to outliers. Indeed, a single outlier can result in a highly inaccurate summary of the data. Yet, it remains the most commonly used measure of association in psychology research. Here we describe a free Matlab((R)) based toolbox (http://sourceforge.net/projects/robustcorrtool/) that computes robust measures of association between two or more random variables: the percentage-bend correlation and skipped-correlations. After illustrating how to use the toolbox, we show that robust methods, where outliers are down weighted or removed and accounted for in significance testing, provide better estimates of the true association with accurate false positive control and without loss of power. The different correlation methods were tested with normal data and normal data contaminated with marginal or bivariate outliers. We report estimates of effect size, false positive rate and power, and advise on which technique to use depending on the data at hand.

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 preprocessing choices on both the global and nodal topological properties of functional brain networks. This study also has important implications for how to choose reliable analytical schemes in brain network studies.

Quantitative genetic properties of four measures of deformity in yellowtail kingfish Seriola lalandi Valenciennes, 1833.

PubMed

Nguyen, N H; Whatmore, P; Miller, A; Knibb, W

2016-02-01

The main aim of this study was to estimate the heritability for four measures of deformity and their genetic associations with growth (body weight and length), carcass (fillet weight and yield) and flesh-quality (fillet fat content) traits in yellowtail kingfish Seriola lalandi. The observed major deformities included lower jaw, nasal erosion, deformed operculum and skinny fish on 480 individuals from 22 families at Clean Seas Tuna Ltd. They were typically recorded as binary traits (presence or absence) and were analysed separately by both threshold generalized models and standard animal mixed models. Consistency of the models was evaluated by calculating simple Pearson correlation of breeding values of full-sib families for jaw deformity. Genetic and phenotypic correlations among traits were estimated using a multitrait linear mixed model in ASReml. Both threshold and linear mixed model analysis showed that there is additive genetic variation in the four measures of deformity, with the estimates of heritability obtained from the former (threshold) models on liability scale ranging from 0.14 to 0.66 (SE 0.32-0.56) and from the latter (linear animal and sire) models on original (observed) scale, 0.01-0.23 (SE 0.03-0.16). When the estimates on the underlying liability were transformed to the observed scale (0, 1), they were generally consistent between threshold and linear mixed models. Phenotypic correlations among deformity traits were weak (close to zero). The genetic correlations among deformity traits were not significantly different from zero. Body weight and fillet carcass showed significant positive genetic correlations with jaw deformity (0.75 and 0.95, respectively). Genetic correlation between body weight and operculum was negative (-0.51, P < 0.05). The genetic correlations' estimates of body and carcass traits with other deformity were not significant due to their relatively high standard errors. Our results showed that there are prospects for genetic selection to improve deformity in yellowtail kingfish and that measures of deformity should be included in the recording scheme, breeding objectives and selection index in practical selective breeding programmes due to the antagonistic genetic correlations of deformed jaws with body and carcass performance. © 2015 John Wiley & Sons Ltd.

Reliability and Validity of Two Self-report Measures to Assess Sedentary Behavior in Older Adults

PubMed Central

Gennuso, Keith P.; Matthews, Charles E.; Colbert, Lisa H.

2015-01-01

Background The purpose of this study was to examine the reliability and validity of two currently available physical activity surveys for assessing time spent in sedentary behavior (SB) in older adults. Methods Fifty-eight adults (≥65 years) completed the Yale Physical Activity Survey for Older Adults (YPAS) and Community Health Activities Model Program for Seniors (CHAMPS) before and after a 10-day period during which they wore an ActiGraph accelerometer (ACC). Intraclass correlation coefficients (ICC) examined test-retest reliability. Overall percent agreement and a kappa statistic examined YPAS validity. Lin’s concordance correlation, Pearson correlation, and Bland-Altman analysis examined CHAMPS validity. Results Both surveys had moderate test-retest reliability (ICC: YPAS=0.59 (P<0.001), CHAMPS=0.64 (P<0.001)) and significantly underestimated SB time. Agreement between YPAS and ACC was low (κ=−0.0003); however, there was a linear increase (P< 0.01) in ACC-derived SB time across YPAS response categories. There was poor agreement between ACC-derived SB and CHAMPS (Lin’s r=0.005; 95% CI, −0.010 to 0.020), and no linear trend across CHAMPS quartiles (p=0.53). Conclusions Neither of the surveys should be used as the sole measure of SB in a study; though the YPAS has the ability to rank individuals, providing it with some merit for use in correlational SB research. PMID:25110344

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.

The reliability and reproducibility of cephalometric measurements: a comparison of conventional and digital methods

PubMed Central

AlBarakati, SF; Kula, KS; Ghoneima, AA

2012-01-01

Objective The aim of this study was to assess the reliability and reproducibility of angular and linear measurements of conventional and digital cephalometric methods. Methods A total of 13 landmarks and 16 skeletal and dental parameters were defined and measured on pre-treatment cephalometric radiographs of 30 patients. The conventional and digital tracings and measurements were performed twice by the same examiner with a 6 week interval between measurements. The reliability within the method was determined using Pearson's correlation coefficient (r2). The reproducibility between methods was calculated by paired t-test. The level of statistical significance was set at p < 0.05. Results All measurements for each method were above 0.90 r2 (strong correlation) except maxillary length, which had a correlation of 0.82 for conventional tracing. Significant differences between the two methods were observed in most angular and linear measurements except for ANB angle (p = 0.5), angle of convexity (p = 0.09), anterior cranial base (p = 0.3) and the lower anterior facial height (p = 0.6). Conclusion In general, both methods of conventional and digital cephalometric analysis are highly reliable. Although the reproducibility of the two methods showed some statistically significant differences, most differences were not clinically significant. PMID:22184624

Development and Validation of an Abbreviated Questionnaire to Easily Measure Cognitive Failure in ICU Survivors: A Multicenter Study.

PubMed

Wassenaar, Annelies; de Reus, Jorn; Donders, A Rogier T; Schoonhoven, Lisette; Cremer, Olaf L; de Lange, Dylan W; van Dijk, Diederik; Slooter, Arjen J C; Pickkers, Peter; van den Boogaard, Mark

2018-01-01

To develop and validate an abbreviated version of the Cognitive Failure Questionnaire that can be used by patients as part of self-assessment to measure functional cognitive outcome in ICU survivors. A retrospective multicenter observational study. The ICUs of two Dutch university hospitals. Adult ICU survivors. None. Cognitive functioning was evaluated between 12 and 24 months after ICU discharge using the full 25-item Cognitive Failure Questionnaire (CFQ-25). Incomplete CFQ-25 questionnaires were excluded from analysis. Forward selection in a linear regression model was used in hospital A to assess which of the CFQ-25 items should be included to prevent a significant loss of correlation between an abbreviated and the full CFQ-25. Subsequently, the performance of an abbreviated Cognitive Failure Questionnaire was determined in hospital B using Pearson's correlation. A Bland-Altman plot was used to examine whether the reduced-item outcome scores of an abbreviated Cognitive Failure Questionnaire were a replacement for the full CFQ-25 outcome scores. Among 1,934 ICU survivors, 1,737 were included, 819 in hospital A, 918 in hospital B. The Pearson's correlation between the abbreviated 14-item Cognitive Failure Questionnaire (CFQ-14) and the CFQ-25 was 0.99. The mean of the difference scores was -0.26, and 95% of the difference scores fell within +5 and -5.5 on a 100-point maximum score. It is feasible to use the abbreviated CFQ-14 to measure self-reported cognitive failure in ICU survivors as this questionnaire has a similar performance as the full CFQ-25.

Significance of Epicardial and Intrathoracic Adipose Tissue Volume among Type 1 Diabetes Patients in the DCCT/EDIC: A Pilot Study

PubMed Central

Budoff, Matthew J.

2016-01-01

Introduction Type 1 diabetes (T1DM) patients are at increased risk of coronary artery disease (CAD). This pilot study sought to evaluate the relationship between epicardial adipose tissue (EAT) and intra-thoracic adipose tissue (IAT) volumes and cardio-metabolic risk factors in T1DM. Method EAT/IAT volumes in 100 patients, underwent non-contrast cardiac computed tomography in the Diabetes Control and Complications Trial /Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study were measured by a certified reader. Fat was defined as pixels’ density of -30 to -190 Hounsfield Unit. The associations were assessed using–Pearson partial correlation and linear regression models adjusted for gender and age with inverse probability sample weighting. Results The weighted mean age was 43 years (range 32–57) and 53% were male. Adjusted for gender, Pearson correlation analysis showed a significant correlation between age and EAT/IAT volumes (both p<0.001). After adjusting for gender and age, participants with greater BMI, higher waist to hip ratio (WTH), higher weighted HbA1c, elevated triglyceride level, and a history of albumin excretion rate of equal or greater than 300 mg/d (AER≥300) or end stage renal disease (ESRD) had significantly larger EAT/IAT volumes. Conclusion T1DM patients with greater BMI, WTH ratio, weighted HbA1c level, triglyceride level and AER≥300/ESRD had significantly larger EAT/IAT volumes. Larger sample size studies are recommended to evaluate independency. PMID:27459689

Dietary diversity score is a useful indicator of micronutrient intake in non-breast-feeding Filipino children.

PubMed

Kennedy, Gina L; Pedro, Maria Regina; Seghieri, Chiara; Nantel, Guy; Brouwer, Inge

2007-02-01

Micronutrient malnutrition remains a problem of public health concern in most developing countries, partly due to monotonous, cereal-based diets that lack diversity. The study objective was to assess whether dietary diversity score (DDS) based on a simple count of food groups consumed and DDS using a 10-g minimum intake for each food group (DDS 10g) are good indicators of adequate micronutrient intake in 24-71-mo-old non-breast-feeding Filipino children. Pearson's correlation and linear regression were used to assess the utility of DDS and DDS 10g as indicators of micronutrient intake. Sensitivity and specificity analysis were used to determine the most appropriate cut-off point for using DDS to categorize children with high probability of adequate micronutrient intake. The average diet of the sample population consisted of 4-5 food groups. The mean probability of adequate nutrient intake (MPA) of 11 micronutrients was 33%. The Pearson's correlation coefficient between MPA and DDS was 0.36 (P<0.001) and for DDS 10g it increased to 0.44 (P<0.001). Intake of individual micronutrients was correlated to DDS for most nutrients. When maximizing sensitivity and specificity, the best cut-off points for achieving 50 and 75% probability of adequate micronutrient intake were 5 and 6 food groups, respectively. DDS and DDS 10g were both significant predictors of adequate micronutrient intake. This study demonstrates the utility of indicators of dietary diversity to predict adequate intake of micronutrients in the diets of young non-breast-feeding children.

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

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.

Examining the Relationship Between Passenger Airline Aircraft Maintenance Outsourcing and Aircraft Safety

NASA Astrophysics Data System (ADS)

Monaghan, Kari L.

The problem addressed was the concern for aircraft safety rates as they relate to the rate of maintenance outsourcing. Data gathered from 14 passenger airlines: AirTran, Alaska, America West, American, Continental, Delta, Frontier, Hawaiian, JetBlue, Midwest, Northwest, Southwest, United, and USAir covered the years 1996 through 2008. A quantitative correlational design, utilizing Pearson's correlation coefficient, and the coefficient of determination were used in the present study to measure the correlation between variables. Elements of passenger airline aircraft maintenance outsourcing and aircraft accidents, incidents, and pilot deviations within domestic passenger airline operations were analyzed, examined, and evaluated. Rates of maintenance outsourcing were analyzed to determine the association with accident, incident, and pilot deviation rates. Maintenance outsourcing rates used in the evaluation were the yearly dollar expenditure of passenger airlines for aircraft maintenance outsourcing as they relate to the total airline aircraft maintenance expenditures. Aircraft accident, incident, and pilot deviation rates used in the evaluation were the yearly number of accidents, incidents, and pilot deviations per miles flown. The Pearson r-values were calculated to measure the linear relationship strength between the variables. There were no statistically significant correlation findings for accidents, r(174)=0.065, p=0.393, and incidents, r(174)=0.020, p=0.793. However, there was a statistically significant correlation for pilot deviation rates, r(174)=0.204, p=0.007 thus indicating a statistically significant correlation between maintenance outsourcing rates and pilot deviation rates. The calculated R square value of 0.042 represents the variance that can be accounted for in aircraft pilot deviation rates by examining the variance in aircraft maintenance outsourcing rates; accordingly, 95.8% of the variance is unexplained. Suggestions for future research include replication of the present study with the inclusion of maintenance outsourcing rate data for all airlines differentiated between domestic and foreign repair station utilization. Replication of the present study every five years is also encouraged to continue evaluating the impact of maintenance outsourcing practices on passenger airline safety.

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.

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.

Increased rates of authorship in radiology publications: a bibliometric analysis of 142,576 articles published worldwide by radiologists between 1991 and 2012.

PubMed

Chow, Daniel S; Ha, Richard; Filippi, Christopher G

2015-01-01

OBJECTIVE; There is evidence in academic medicine that the number of authors per paper has increased over time. The goal of this study was to quantitatively analyze authorship trends in the field of radiology over 20 years. A search of the National Library of Medicine MEDLINE database was conducted to identify articles published by radiology departments between 1991 and 2012. Country of origin, article study design, and journal impact factor were recorded. The increase in number of authors per paper was assessed by linear and nonlinear regression. Pearson correlation was used to assess the relation between journal impact factor and number of authors. A total of 142,576 articles and 699,257 authors were identified during the study period. The mean number of authors per paper displayed linear growth from 3.9 to 5.7 (p < 0.0001). The proportion of single authors declined from 11% in 1991 to 4.4% in 2012. The number of clinical trials increased in a linear pattern, review articles in an exponential pattern, and case reports in a logistic pattern (p < 0.0001 for each). Countries with the highest number of authors per paper were Japan, Italy, and Germany. The number of articles funded by the U.S. National Institutes of Health (NIH) displayed exponential growth and of non-NIH-funded articles displayed linear growth (p < 0.0001 for each). A negligible relation was observed between journal impact factor and number of authors (Pearson r = 0.1066). Radiology has had a steady increase in mean number of authors per paper since the early 1990s that has varied by study design. The increase is probably multi-factorial and includes components of author inflation and increasing complexity of research. Findings support the need for reemphasis of authorship criteria to preserve authorship value and accountability.

Spatial correlation of hydrometeor occurrence, reflectivity, and rain rate from CloudSat

NASA Astrophysics Data System (ADS)

Marchand, Roger

2012-03-01

This paper examines the along-track vertical and horizontal structure of hydrometeor occurrence, reflectivity, and column rain rate derived from CloudSat. The analysis assumes hydrometeors statistics in a given region are horizontally invariant, with the probability of hydrometeor co-occurrence obtained simply by determining the relative frequency at which hydrometeors can be found at two points (which may be at different altitudes and offset by a horizontal distance, Δx). A correlation function is introduced (gamma correlation) that normalizes hydrometeor co-occurrence values to the range of 1 to -1, with a value of 0 meaning uncorrelated in the usual sense. This correlation function is a generalization of the alpha overlap parameter that has been used in recent studies to describe the overlap between cloud (or hydrometeor) layers. Examples of joint histograms of reflectivity at two points are also examined. The analysis shows that the traditional linear (or Pearson) correlation coefficient provides a useful one-to-one measure of the strength of the relationship between hydrometeor reflectivity at two points in the horizontal (that is, two points at the same altitude). While also potentially useful in the vertical direction, the relationship between reflectivity values at different altitudes is not as well described by the linear correlation coefficient. The decrease in correlation of hydrometeor occurrence and reflectivity with horizontal distance, as well as precipitation occurrence and column rain rate, can be reasonably well fit with a simple two-parameter exponential model. In this paper, the North Pacific and tropical western Pacific are examined in detail, as is the zonal dependence.

Consumer knowledge and attitudes about genetically modified food products and labelling policy.

PubMed

Vecchione, Melissa; Feldman, Charles; Wunderlich, Shahla

2015-05-01

The purpose of this study was to examine the relationship between consumer knowledge, attitudes and behaviours towards foods containing genetically modified organisms (GMOs) and the prevalence of GMO labelling in northern New Jersey supermarkets. This cross-sectional study surveyed 331 adults, New Jersey supermarket customers (mean age 26 years old, 79.8% women). The results show a strong, positive correlation between consumer attitudes towards foods not containing GMOs and purchasing behaviour (Pearson's r = 0.701, p < 0.001) with lesser correlations between knowledge and behaviour (Pearson's r = 0.593, p < 0.001) and knowledge and attitudes (Pearson's r = 0.413, p < 0.001). GMO labelling would assist consumers in making informed purchase decisions.

Estimation of axial curvature of anterior sclera: correlation between axial length and anterior scleral curvature as affected by angle kappa.

PubMed

Lee, Sang-Mok; Choi, Hyuk Jin; Choi, Heejin; Kim, Mee Kum; Wee, Won Ryang

2016-10-07

BACKGROUND: Though the development and fitting of scleral contact lenses are expanding steadily, there is no simple method to provide scleral metrics for scleral contact lens fitting yet. The aim of this study was to establish formulae for estimation of the axial radius of curvature (ARC) of the anterior sclera using ocular biometric parameters that can be easily obtained with conventional devices. A semi-automated stitching method and a computational analysis tool for calculating ARC were developed by using the ImageJ and MATLAB software. The ARC of all the ocular surface points were analyzed from the composite horizontal cross-sectional images of the right eyes of 24 volunteers; these measurements were obtained using anterior segment optical coherence tomography for a previous study (AS-OCT; Visante). Ocular biometric parameters were obtained from the same volunteers with slit-scanning topography and partial coherence interferometry. Correlation analysis was performed between the ARC at 8 mm to the axis line (ARC[8]) and other ocular parameters (including age). With ARC obtained on several nasal and temporal points (7.0, 7.5, 8.0, 8.5, and 9.0 mm from the axis line), univariate and multivariate linear regression analyses were performed to develop a model for estimating ARC with the help of ocular biometric parameters. Axial length, spherical equivalent, and angle kappa showed correlations with temporal ARC[8] (tARC[8]; Pearson's r = 0.653, -0.579, and -0.341; P = 0.001, 0.015, and 0.015, respectively). White-to-white corneal diameter (WTW) and anterior chamber depth (ACD) showed correlation with nasal ARC[8] (nARC[8]; Pearson's r = -0.492 and -0.461; P = 0.015 and 0.023, respectively). The formulae for estimating scleral curvatures (tARC, nARC, and average ARC) were developed as a function of axial length, ACD, WTW, and distance from the axis line, with good determinant power (72 - 80 %; SPSS ver. 22.0). Angle kappa showed strong correlation with axial length (Pearson's r = -0.813, P <0.001), and the different correlation patterns of nasal and temporal ARC with axial length can be explained by the ocular surface deviation represented by angle kappa. Axial length, ACD, and WTW are useful parameters for estimating the ARC of the anterior sclera, which is important for the haptic design of scleral contact lenses. Angle kappa affects the discrepancies between the nasal and temporal scleral curvature.

Periodontal inflamed surface area as a novel numerical variable describing periodontal conditions

PubMed Central

2017-01-01

Purpose A novel index, the periodontal inflamed surface area (PISA), represents the sum of the periodontal pocket depth of bleeding on probing (BOP)-positive sites. In the present study, we evaluated correlations between PISA and periodontal classifications, and examined PISA as an index integrating the discrete conventional periodontal indexes. Methods This study was a cross-sectional subgroup analysis of data from a prospective cohort study investigating the association between chronic periodontitis and the clinical features of ankylosing spondylitis. Data from 84 patients without systemic diseases (the control group in the previous study) were analyzed in the present study. Results PISA values were positively correlated with conventional periodontal classifications (Spearman correlation coefficient=0.52; P<0.01) and with periodontal indexes, such as BOP and the plaque index (PI) (r=0.94; P<0.01 and r=0.60; P<0.01, respectively; Pearson correlation test). Porphyromonas gingivalis (P. gingivalis) expression and the presence of serum P. gingivalis antibodies were significant factors affecting PISA values in a simple linear regression analysis, together with periodontal classification, PI, bleeding index, and smoking, but not in the multivariate analysis. In the multivariate linear regression analysis, PISA values were positively correlated with the quantity of current smoking, PI, and severity of periodontal disease. Conclusions PISA integrates multiple periodontal indexes, such as probing pocket depth, BOP, and PI into a numerical variable. PISA is advantageous for quantifying periodontal inflammation and plaque accumulation. PMID:29093989

Progression of Mortality due to Diseases of the Circulatory System and Human Development Index in Rio de Janeiro Municipalities

PubMed Central

Soares, Gabriel Porto; Klein, Carlos Henrique; Silva, Nelson Albuquerque de Souza e; de Oliveira, Glaucia Maria Moraes

2016-01-01

Background Diseases of the circulatory system (DCS) are the major cause of death in Brazil and worldwide. Objective To correlate the compensated and adjusted mortality rates due to DCS in the Rio de Janeiro State municipalities between 1979 and 2010 with the Human Development Index (HDI) from 1970 onwards. Methods Population and death data were obtained in DATASUS/MS database. Mortality rates due to ischemic heart diseases (IHD), cerebrovascular diseases (CBVD) and DCS adjusted by using the direct method and compensated for ill-defined causes. The HDI data were obtained at the Brazilian Institute of Applied Research in Economics. The mortality rates and HDI values were correlated by estimating Pearson linear coefficients. The correlation coefficients between the mortality rates of census years 1991, 2000 and 2010 and HDI data of census years 1970, 1980 and 1991 were calculated with discrepancy of two demographic censuses. The linear regression coefficients were estimated with disease as the dependent variable and HDI as the independent variable. Results In recent decades, there was a reduction in mortality due to DCS in all Rio de Janeiro State municipalities, mainly because of the decline in mortality due to CBVD, which was preceded by an elevation in HDI. There was a strong correlation between the socioeconomic indicator and mortality rates. Conclusion The HDI progression showed a strong correlation with the decline in mortality due to DCS, signaling to the relevance of improvements in life conditions. PMID:27849263

Progression of Mortality due to Diseases of the Circulatory System and Human Development Index in Rio de Janeiro Municipalities.

PubMed

Soares, Gabriel Porto; Klein, Carlos Henrique; Silva, Nelson Albuquerque de Souza E; Oliveira, Glaucia Maria Moraes de

2016-10-01

Diseases of the circulatory system (DCS) are the major cause of death in Brazil and worldwide. To correlate the compensated and adjusted mortality rates due to DCS in the Rio de Janeiro State municipalities between 1979 and 2010 with the Human Development Index (HDI) from 1970 onwards. Population and death data were obtained in DATASUS/MS database. Mortality rates due to ischemic heart diseases (IHD), cerebrovascular diseases (CBVD) and DCS adjusted by using the direct method and compensated for ill-defined causes. The HDI data were obtained at the Brazilian Institute of Applied Research in Economics. The mortality rates and HDI values were correlated by estimating Pearson linear coefficients. The correlation coefficients between the mortality rates of census years 1991, 2000 and 2010 and HDI data of census years 1970, 1980 and 1991 were calculated with discrepancy of two demographic censuses. The linear regression coefficients were estimated with disease as the dependent variable and HDI as the independent variable. In recent decades, there was a reduction in mortality due to DCS in all Rio de Janeiro State municipalities, mainly because of the decline in mortality due to CBVD, which was preceded by an elevation in HDI. There was a strong correlation between the socioeconomic indicator and mortality rates. The HDI progression showed a strong correlation with the decline in mortality due to DCS, signaling to the relevance of improvements in life conditions.

An integrated, ethically driven environmental model of clinical decision making in emergency settings.

PubMed

Wolf, Lisa

2013-02-01

To explore the relationship between multiple variables within a model of critical thinking and moral reasoning. A quantitative descriptive correlational design using a purposive sample of 200 emergency nurses. Measured variables were accuracy in clinical decision-making, moral reasoning, perceived care environment, and demographics. Analysis was by bivariate correlation using Pearson's product-moment correlation coefficients, chi square and multiple linear regression analysis. The elements as identified in the integrated ethically-driven environmental model of clinical decision-making (IEDEM-CD) corrected depict moral reasoning and environment of care as factors significantly affecting accuracy in decision-making. The integrated, ethically driven environmental model of clinical decision making is a framework useful for predicting clinical decision making accuracy for emergency nurses in practice, with further implications in education, research and policy. A diagnostic and therapeutic framework for identifying and remediating individual and environmental challenges to accurate clinical decision making. © 2012, The Author. International Journal of Nursing Knowledge © 2012, NANDA International.

[Association between social deprivation and causes of mortality among elderly residents in the city of Recife, Pernambuco State, Brazil].

PubMed

Silva, Vanessa de Lima; Leal, Márcia Carréra Campos; Marino, Jacira Guiro; Marques, Ana Paula de Oliveira

2008-05-01

This paper aims to analyze mortality among elderly residents in the city of Recife, Pernambuco State, Brazil, and its association with social deprivation (hardship) in the year 2000. An ecological study was performed, and 94 neighborhoods and 5 social strata were analyzed. The independent variable consisted of a composite social deprivation indicator, obtained for each neighborhood and calculated through a scoring technique based on census variables: water supply, sewage, illiteracy, and head-of-household's years of schooling and income. The dependent variables were: mortality rate in individuals > 60 years of age and cause-specific mortality rates. The association was calculated by means of the Pearson correlation coefficient, linear regression, and mortality odds between social deprivation strata formed by grouping of neighborhoods according to the indicator's quintiles. The data show a statistically significant positive correlation between social deprivation and mortality in the elderly from pneumonia, protein-energy malnutrition, tuberculosis, diarrhea/gastroenteritis, and traffic accidents, and a negative correlation with deaths from bronchopulmonary and breast cancers.

Depression and Obesity/Overweight Association in Elderly Women: a Community-Based Case-Control Study.

PubMed

Ahmadi, Seyed Mehdi; Keshavarzi, Sareh; Mostafavi, Seyed-Ali; Bagheri Lankarani, Kamran

2015-11-01

Overweight/obesity and depression are common among women especially in the elderly and can lead to unfavorable outcomes. We aimed to determine the association of overweight with depression and also to find any correlation of depression with some anthropometric indices in old women. A total of 94 depressed elderly women were compared with 99 non-depressed controls. The structured diagnostic interview based on DSM-IV were performed to diagnose depression, and Geriatric Depression Scale (GDS) was completed to rate it. Anthropometric indices were measured and compared between groups. Pearson correlation coefficients were determined for linear relations between variables. Odds Ratio of obesity and overweight in depressed subjects comparing with normal participants was 1.45 (95%CI=0.63-3.32). A significant correlation was observed between BMI and GDS score (r=0.231, P-value=0.001). Total body fat (P-value=0.001) and BMI (P-value=0.016) were significantly higher in depressed women than non-depressed women. Despite the significantly higher total body fat and BMI among old women with depression, only a weak correlation was seen between BMI and GDS score.

A systematic correlation analysis of carotenoids, chlorophyll, non-pigmented cell mass, and cell number for the blueprint of Dunaliella salina culture in a photobioreactor.

PubMed

Song, Hyeon Gi; Byeon, Seon Yeong; Chung, Goo Yong; Jung, Sang-Myung; Choi, Jung Il; Shin, Hwa Sung

2018-05-28

Microalgal carotenoids are attractive health ingredients, but their production should be optimized to improve cost-effectiveness. Understanding cellular physiology centered on carotenoid synthesis is the prerequisite for this work. Therefore, systematic correlation analyses were conducted among chlorophyll, carotenoids, non-pigmented cell mass, and cell number of Dunaliella salina in a specified condition over a relatively long culture time. First, an integrated correlation was performed: a temporal profile of the carotenoids was correlated with those of other factors, including chlorophyll, non-pigmented cell mass, and cell number. Pearson and Spearman correlation analyses were performed to identify linearity and monotonicity of the correlation, respectively, and then cross-correlation was executed to determine if the correlation had a time lag. Second, to understand the cellular potential of metabolism, the procedure was repeated to provide a data set composed of the specific synthesis rates of the factors or growth rate, which additionally provided kinetic correlations among the constituting components of the cell, excluding the effect of cell number. This systematic approach could generate a blueprint model that is composed of only what it needs, which could make it possible to efficiently control and optimize the process.

Defining a Contemporary Ischemic Heart Disease Genetic Risk Profile Using Historical Data.

PubMed

Mosley, Jonathan D; van Driest, Sara L; Wells, Quinn S; Shaffer, Christian M; Edwards, Todd L; Bastarache, Lisa; McCarty, Catherine A; Thompson, Will; Chute, Christopher G; Jarvik, Gail P; Crosslin, David R; Larson, Eric B; Kullo, Iftikhar J; Pacheco, Jennifer A; Peissig, Peggy L; Brilliant, Murray H; Linneman, James G; Denny, Josh C; Roden, Dan M

2016-12-01

Continued reductions in morbidity and mortality attributable to ischemic heart disease (IHD) require an understanding of the changing epidemiology of this disease. We hypothesized that we could use genetic correlations, which quantify the shared genetic architectures of phenotype pairs and extant risk factors from a historical prospective study to define the risk profile of a contemporary IHD phenotype. We used 37 phenotypes measured in the ARIC study (Atherosclerosis Risk in Communities; n=7716, European ancestry subjects) and clinical diagnoses from an electronic health record (EHR) data set (n=19 093). All subjects had genome-wide single-nucleotide polymorphism genotyping. We measured pairwise genetic correlations (rG) between the ARIC and EHR phenotypes using linear mixed models. The genetic correlation estimates between the ARIC risk factors and the EHR IHD were modestly linearly correlated with hazards ratio estimates for incident IHD in ARIC (Pearson correlation [r]=0.62), indicating that the 2 IHD phenotypes had differing risk profiles. For comparison, this correlation was 0.80 when comparing EHR and ARIC type 2 diabetes mellitus phenotypes. The EHR IHD phenotype was most strongly correlated with ARIC metabolic phenotypes, including total:high-density lipoprotein cholesterol ratio (rG=-0.44, P=0.005), high-density lipoprotein (rG=-0.48, P=0.005), systolic blood pressure (rG=0.44, P=0.02), and triglycerides (rG=0.38, P=0.02). EHR phenotypes related to type 2 diabetes mellitus, atherosclerotic, and hypertensive diseases were also genetically correlated with these ARIC risk factors. The EHR IHD risk profile differed from ARIC and indicates that treatment and prevention efforts in this population should target hypertensive and metabolic disease. © 2016 American Heart Association, Inc.

Socio-economic factors associated with infant mortality in Italy: an ecological study.

PubMed

Dallolio, Laura; Di Gregori, Valentina; Lenzi, Jacopo; Franchino, Giuseppe; Calugi, Simona; Domenighetti, Gianfranco; Fantini, Maria Pia

2012-08-16

One issue that continues to attract the attention of public health researchers is the possible relationship in high-income countries between income, income inequality and infant mortality (IM). The aim of this study was to assess the associations between IM and major socio-economic determinants in Italy. Associations between infant mortality rates in the 20 Italian regions (2006-2008) and the Gini index of income inequality, mean household income, percentage of women with at least 8 years of education, and percentage of unemployed aged 15-64 years were assessed using Pearson correlation coefficients. Univariate linear regression and multiple stepwise linear regression analyses were performed to determine the magnitude and direction of the effect of the four socio-economic variables on IM. The Gini index and the total unemployment rate showed a positive strong correlation with IM (r = 0.70; p < 0.001 and r = 0.84; p < 0.001 respectively), mean household income showed a strong negative correlation (r = -0.78; p < 0.001), while female educational attainment presented a weak negative correlation (r = -0.45; p < 0.05). Using a multiple stepwise linear regression model, only unemployment rate was independently associated with IM (b = 0.15, p < 0.001). In Italy, a high-income country where health care is universally available, variations in IM were strongly associated with relative and absolute income and unemployment rate. These results suggest that in Italy IM is not only related to income distribution, as demonstrated for other developed countries, but also to economic factors such as absolute income and unemployment. In order to reduce IM and the existing inequalities, the challenge for Italian decision makers is to promote economic growth and enhance employment levels.

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.

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.

The Portuguese version of the Epilepsy Surgery Inventory (ESI-55): cross-cultural adaptation and evaluation of psychometric properties.

PubMed

Alonso, Neide Barreira; Ciconelli, Rozana Mesquita; da Silva, Tatiana Indelicato; Westphal-Guitti, Ana Carolina; Azevedo, Auro Mauro; da Silva Noffs, Maria Helena; Caboclo, Luís Otávio Sales Ferreira; Sakamoto, Américo Ceiki; Targas Yacubian, Elza Márcia

2006-08-01

The purpose of this study was to develop a Portuguese version of the Epilepsy Surgery Inventory (ESI-55) and to assess its psychometric properties. Sixty patients with temporal lobe epilepsy related to unilateral mesial temporal sclerosis who underwent presurgical evaluation at the Universidade Federal de São Paulo (UNIFESP) formed the sample for this study. The psychometric properties of the ESI-55 included: reliability, validity, and responsiveness. Internal consistency was high in all domains (Cronbach's alpha ranging from 0.76 for Social Function to 0.88 for Physical Function) except Overall Quality of Life (alpha=0.45). Test-retest reliability after 1 week was good, with the intraclass correlation coefficient ranging from 0.79 (Energy/Fatigue) to 0.92 (Role Limitations due to Emotional Problems). Interrater reliability ranged from 0.84 (Cognitive Function) to 0.94 (Role Limitations due to Physical Problems). For construct validity, we verified a high correlation between the ESI-55 and Health Assessment Questionnaire-8 for the Physical Function domain (Pearson linear correlation=-0.84), and a moderate correlation for the Pain domain (P=-0.58), but for the other subscales no correlation was detected. Beck Depression Inventory and ESI-55 domains were highly statistically correlated (ANOVA: P<0.005), but there was no association of the Cognitive Function and Role Limitations due to Memory Problems subscales with neuropsychological evaluation (Pearson coefficient: P>0.05). With respect to demographic characteristics, a statistically significant correlation was observed for the variable educational level (Student t, P<0.005) and ESI-55 scores. There was a high correlation between seizure frequency and ESI-55 domains for clinical variables (ANOVA, P<0.005). Surgical treatment in this series improved health-related quality of life in the seizure-free group in three domains--Health Perception (1.24), Emotional Well-Being (1.32), and Energy/Fatigue (1.48)-as reflected by the standard response mean and the effect size of the sample. Our results support the psychometric properties of the Portuguese version of the ESI-55 as a measure of health-related quality of life.

Rapid detection of Escherichia coli and enterococci in recreational water using an immunomagnetic separation/adenosine triphosphate technique

USGS Publications Warehouse

Bushon, R.N.; Brady, A.M.; Likirdopulos, C.A.; Cireddu, J.V.

2009-01-01

Aims: The aim of this study was to examine a rapid method for detecting Escherichia coli and enterococci in recreational water. Methods and Results: Water samples were assayed for E. coli and enterococci by traditional and immunomagnetic separation/adenosine triphosphate (IMS/ATP) methods. Three sample treatments were evaluated for the IMS/ATP method: double filtration, single filtration, and direct analysis. Pearson's correlation analysis showed strong, significant, linear relations between IMS/ATP and traditional methods for all sample treatments; strongest linear correlations were with the direct analysis (r = 0.62 and 0.77 for E. coli and enterococci, respectively). Additionally, simple linear regression was used to estimate bacteria concentrations as a function of IMS/ATP results. The correct classification of water-quality criteria was 67% for E. coli and 80% for enterococci. Conclusions: The IMS/ATP method is a viable alternative to traditional methods for faecal-indicator bacteria. Significance and Impact of the Study: The IMS/ATP method addresses critical public health needs for the rapid detection of faecal-indicator contamination and has potential for satisfying US legislative mandates requiring methods to detect bathing water contamination in 2 h or less. Moreover, IMS/ATP equipment is considerably less costly and more portable than that for molecular methods, making the method suitable for field applications. ?? 2009 The Authors.

A Linear Empirical Model of Self-Regulation on Flourishing, Health, Procrastination, and Achievement, Among University Students

PubMed Central

Garzón-Umerenkova, Angélica; de la Fuente, Jesús; Amate, Jorge; Paoloni, Paola V.; Fadda, Salvatore; Pérez, Javier Fiz

2018-01-01

This research aimed to analyze the linear bivariate correlation and structural relations between self-regulation -as a central construct-, with flow, health, procrastination and academic performance, in an academic context. A total of 363 college students took part, 101 men (27.8%) and 262 women (72.2%). Participants had an average age of 22 years and were between the first and fifth year of studies. They were from five different programs and two universities in Bogotá city (Colombia). A validated ad hoc questionnaire of physical and psychological health was applied along with a battery of tests to measure self-regulation, procrastination, and flourishing. To establish an association relationship, Pearson bivariate correlations were performed using SPSS software (v. 22.0), and structural relationship predictive analysis was performed using an SEM on AMOS software (v. 22.0). Regarding this linear association, it was established that (1) self-regulation has a significant positive association on flourishing and overall health, and a negative effect on procrastination. Regarding the structural relation, it confirmed that (2) self-regulation is a direct and positive predictor of flourishing and health; (3) self-regulation predicts procrastination directly and negatively, and academic performance indirectly and positively; and (4) age and gender have a prediction effect on the analyzed variables. Implications, limitations and future research scope are discussed. PMID:29706922

A Linear Empirical Model of Self-Regulation on Flourishing, Health, Procrastination, and Achievement, Among University Students.

PubMed

Garzón-Umerenkova, Angélica; de la Fuente, Jesús; Amate, Jorge; Paoloni, Paola V; Fadda, Salvatore; Pérez, Javier Fiz

2018-01-01

This research aimed to analyze the linear bivariate correlation and structural relations between self-regulation -as a central construct-, with flow, health, procrastination and academic performance, in an academic context. A total of 363 college students took part, 101 men (27.8%) and 262 women (72.2%). Participants had an average age of 22 years and were between the first and fifth year of studies. They were from five different programs and two universities in Bogotá city (Colombia). A validated ad hoc questionnaire of physical and psychological health was applied along with a battery of tests to measure self-regulation, procrastination, and flourishing. To establish an association relationship, Pearson bivariate correlations were performed using SPSS software (v. 22.0), and structural relationship predictive analysis was performed using an SEM on AMOS software (v. 22.0). Regarding this linear association, it was established that (1) self-regulation has a significant positive association on flourishing and overall health, and a negative effect on procrastination. Regarding the structural relation, it confirmed that (2) self-regulation is a direct and positive predictor of flourishing and health; (3) self-regulation predicts procrastination directly and negatively, and academic performance indirectly and positively; and (4) age and gender have a prediction effect on the analyzed variables. Implications, limitations and future research scope are discussed.

Near-infrared spectroscopy during stagnant ischemia estimates central venous oxygen saturation and mixed venous oxygen saturation discrepancy in patients with severe left heart failure and additional sepsis/septic shock.

PubMed

Mozina, Hugo; Podbregar, Matej

2010-01-01

Discrepancies of 5-24% between superior vena cava oxygen saturation (ScvO2) and mixed venous oxygen saturation (SvO2) have been reported in patients with severe heart failure. Thenar muscle tissue oxygenation (StO2) measured with near-infrared spectroscopy (NIRS) during arterial occlusion testing decreases slower in sepsis/septic shock patients (lower StO2 deoxygenation rate). The StO2 deoxygenation rate is influenced by dobutamine. The aim of this study was to determine the relationship between the StO2 deoxygenation rate and the ScvO2-SvO2 discrepancy in patients with severe left heart failure and additional sepsis/septic shock treated with or without dobutamine. Fifty-two patients with severe left heart failure due to primary heart disease with additional severe sepsis/septic shock were included. SvO2 and ScvO2 were compared to the thenar muscle StO2 before and during arterial occlusion. SvO2 correlated significantly with ScvO2 (Pearson correlation 0.659, P = 0.001), however, Bland Altman analysis showed a clinically important difference between both variables (ScvO2-SvO2 mean 72 +/- 8%, ScvO2-SvO2 difference 9.4 +/- 7.5%). The ScvO2-SvO2 difference correlated with plasma lactate (Pearson correlation 0.400, P = 0.003) and the StO2 deoxygenation rate (Pearson correlation 0.651, P = 0.001). In the group of patients treated with dobutamine, the ScvO2-SvO2 difference correlated with plasma lactate (Pearson correlation 0.389, P = 0.011) and the StO2 deoxygenation rate (Pearson correlation 0.777, P = 0.0001). In patients with severe heart failure with additional severe sepsis/septic shock the ScvO2-SvO2 discrepancy presents a clinical problem. In these patients the skeletal muscle StO2 deoxygenation rate is inversely proportional to the difference between ScvO2 and SvO2; dobutamine does not influence this relationship. When using ScvO2 as a treatment goal, the NIRS measurement may prove to be a useful non-invasive diagnostic test to uncover patients with a normal ScvO2 but potentially an abnormally low SvO2. NCT00384644 ClinicalTrials.Gov.

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 and specific preprocessing choices on both the global and nodal topological properties of functional brain networks. This study also has important implications for how to choose reliable analytical schemes in brain network studies. PMID:22412922

Correlation and Comparison of Various Anthropometric Measurements of Body Fat Distribution and Sagittal Abdominal Diameter as a Screening Tool for Cardio Metabolic Risk Factors and Ischaemic Heart Disease in Elderly Population.

PubMed

Sharda, Meenaxi; Jain, Pankaj; Gupta, Atul; Nagar, Deepti; Soni, Anil

2015-01-01

Primary objective of this study was to assess utility of sagittal abdominal diameter (SAD) as a cardio vascular risk predictor and compare various anthropometric measurement of body fat distribution in elderly patients. Four hundred patients were enrolled in study. Elderly patients more than 60 year of age attending medical OPD, geriatric OPD and suitable indoor patients who were willing to participate in the study were included. SAD was significantly higher in patient with ischaemic heart disease (group 1) than patient without ischaemic heart disease (Group 2) (P < 0.001 for male and female). SAD was better than WC to ascertain individual cardio metabolic risk factors in male, especially FBS (Pearson correlation .33 vs. .29), total cholesterol (Pearson correlation .24 vs. .20) as well as LDL cholesterol (Pearson correlation .13 vs. .05), while in female WC and SAD showed equal correlation with individual cardio metabolic risk factors. In patient with metabolic syndrome IHD group showed considerably higher mean SAD values. SAD also showed very good correlation with individual cardio metabolic risk factors especially in elderly male, while in female both SAD and.WC were almost equivalent.

Extra-articular manifestations of seronegative and seropositive rheumatoid arthritis.

PubMed

Sahatciu-Meka, Vjollca; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana; Rexhepi, Mjellma

2010-02-01

Although considered a "joint disease," rheumatoid arthritis is associated with the involvement of extra-articular manifestations. The aim of the study is the investigation and comparison of frequency and type of extra-articular manifestations in a well defined community based cohort of patients with seropositive and seronegative rheumatoid arthritis. Using the ACR (1987) criteria for rheumatoid arthritis, patients have been classified into the 2nd and 3rd functional class (ARA). The studied group consisted of 125 seronegative patients with titters lower than 1:64 as defined by Rose-Waaler test, whereas the control group consisted of 125 seropositive patients with titters of 1:64 or higher. All patients were between 25-60 years of age (Xb=49,96), with disease duration between 1-27 years (Xb=6,41). In order to present the findings of the study, the structure, prevalence, arithmetic mean (Xb), standard deviation (SB), variation quotient (QV%) and variation interval (Rmax-Rmin) have been used. Probability level has been expressed by p<0,01 and p<0,05. Correlation between the number of extra-articular manifestations and duration of the disease has been calculated by means of Pearson linear correlation. Higher presence of diffuse lung fibrosis, central and peripheral nervous system damages have been confirmed in the seropositive group, and osteoporosis in the seronegative; however, no statistical difference has been found. In extra-articular manifestations, "rheumatoid core" in the seropositive subset (chi2=4,80, p<0,05) presented significant statistical difference. Rheumatoid nodules were more frequent in seropositive subset (12%:16%), in both sexes; however, they were not of significant statistical difference. Neuropathy and lung diseases were also frequently present in seropositive group, but no statistical difference has been found regarding the statistical difference. Longer duration of the disease resulted in an increase of the number of extra-articular manifestations. Calculated linear correlation by Pearson, resulted as positive and high correlation in total (r=0,36, p<0,01), and for groups [(r=0,52, p<0,01) seronegative, (r=0,25, p<0,01) seropositive], nevertheless no significant statistical difference was found regarding the sero-status. In conclusion, extra-articular manifestations are more frequent in the seropositive patients. The longer the duration of the disease the larger the number of extra-articular manifestations. Differences with regard to sero-status and sex, with some exceptions, are not observed.

[Ecological executive function characteristics and effects of executive function on social adaptive function in school-aged children with epilepsy].

PubMed

Xu, X J; Wang, L L; Zhou, N

2016-02-23

To explore the characteristics of ecological executive function in school-aged children with idiopathic or probably symptomatic epilepsy and examine the effects of executive function on social adaptive function. A total of 51 school-aged children with idiopathic or probably symptomatic epilepsy aged 5-12 years at our hospital and 37 normal ones of the same gender, age and educational level were included. The differences in ecological executive function and social adaptive function were compared between the two groups with the Behavior Rating Inventory of Executive Function (BRIEF) and Child Adaptive Behavior Scale, the Pearson's correlation test and multiple stepwise linear regression were used to explore the impact of executive function on social adaptive function. The scores of school-aged children with idiopathic or probably symptomatic epilepsy in global executive composite (GEC), behavioral regulation index (BRI) and metacognition index (MI) of BRIEF ((62±12), (58±13) and (63±12), respectively) were significantly higher than those of the control group ((47±7), (44±6) and (48±8), respectively))(P<0.01). The scores of school-aged children with idiopathic or probably symptomatic epilepsy in adaptive behavior quotient (ADQ), independence, cognition, self-control ((86±22), (32±17), (49±14), (41±16), respectively) were significantly lower than those of the control group ((120±12), (59±14), (59±7) and (68±10), respectively))(P<0.01). Pearson's correlation test showed that the scores of BRIEF, such as GEC, BRI, MI, inhibition, emotional control, monitoring, initiation and working memory had significantly negative correlations with the score of ADQ, independence, self-control ((r=-0.313--0.741, P<0.05)). Also, GEC, inhibition, MI, initiation, working memory, plan, organization and monitoring had significantly negative correlations with the score of cognition ((r=-0.335--0.437, P<0.05)); Multiple stepwise linear regression analysis showed that BRI, inhibition and working memory were closely related with the social adaptive function of school-aged children with idiopathic or probably symptomatic epilepsy. School-aged children with idiopathic or probably symptomatic epilepsy may have significantly ecological executive function impairment and social adaptive function reduction. The aspects of BRI, inhibition and working memory in ecological executive function are significantly related with social adaptive function in school-aged children with epilepsy.

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.

Autofocus algorithm using one-dimensional Fourier transform and Pearson correlation

NASA Astrophysics Data System (ADS)

Bueno Mario, A.; Alvarez-Borrego, Josue; Acho, L.

2004-10-01

A new autofocus algorithm based on one-dimensional Fourier transform and Pearson correlation for Z automatized microscope is proposed. Our goal is to determine in fast response time and accuracy, the best focused plane through an algorithm. We capture in bright and dark field several images set at different Z distances from biological organism sample. The algorithm uses the one-dimensional Fourier transform to obtain the image frequency content of a vectors pattern previously defined comparing the Pearson correlation of these frequency vectors versus the reference image frequency vector, the most out of focus image, we find the best focusing. Experimental results showed the algorithm has fast response time and accuracy in getting the best focus plane from captured images. In conclusions, the algorithm can be implemented in real time systems due fast response time, accuracy and robustness. The algorithm can be used to get focused images in bright and dark field and it can be extended to include fusion techniques to construct multifocus final images beyond of this paper.

Image stitching and image reconstruction of intestines captured using radial imaging capsule endoscope

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Jeng, Wei-De; Wu, Yin-Yi; Dung, Lan-Rong; Wu, Hsien-Ming; Weng, Ping-Kuo; Huang, Ker-Jer; Chiu, Luan-Jiau

2012-05-01

This study investigates image processing using the radial imaging capsule endoscope (RICE) system. First, an experimental environment is established in which a simulated object has a shape that is similar to a cylinder, such that a triaxial platform can be used to push the RICE into the sample and capture radial images. Then four algorithms (mean absolute error, mean square error, Pearson correlation coefficient, and deformation processing) are used to stitch the images together. The Pearson correlation coefficient method is the most effective algorithm because it yields the highest peak signal-to-noise ratio, higher than 80.69 compared to the original image. Furthermore, a living animal experiment is carried out. Finally, the Pearson correlation coefficient method and vector deformation processing are used to stitch the images that were captured in the living animal experiment. This method is very attractive because unlike the other methods, in which two lenses are required to reconstruct the geometrical image, RICE uses only one lens and one mirror.

Inferring gene regression networks with model trees

PubMed Central

2010-01-01

Background Novel strategies are required in order to handle the huge amount of data produced by microarray technologies. To infer gene regulatory networks, the first step is to find direct regulatory relationships between genes building the so-called gene co-expression networks. They are typically generated using correlation statistics as pairwise similarity measures. Correlation-based methods are very useful in order to determine whether two genes have a strong global similarity but do not detect local similarities. Results We propose model trees as a method to identify gene interaction networks. While correlation-based methods analyze each pair of genes, in our approach we generate a single regression tree for each gene from the remaining genes. Finally, a graph from all the relationships among output and input genes is built taking into account whether the pair of genes is statistically significant. For this reason we apply a statistical procedure to control the false discovery rate. The performance of our approach, named REGNET, is experimentally tested on two well-known data sets: Saccharomyces Cerevisiae and E.coli data set. First, the biological coherence of the results are tested. Second the E.coli transcriptional network (in the Regulon database) is used as control to compare the results to that of a correlation-based method. This experiment shows that REGNET performs more accurately at detecting true gene associations than the Pearson and Spearman zeroth and first-order correlation-based methods. Conclusions REGNET generates gene association networks from gene expression data, and differs from correlation-based methods in that the relationship between one gene and others is calculated simultaneously. Model trees are very useful techniques to estimate the numerical values for the target genes by linear regression functions. They are very often more precise than linear regression models because they can add just different linear regressions to separate areas of the search space favoring to infer localized similarities over a more global similarity. Furthermore, experimental results show the good performance of REGNET. PMID:20950452

Are Self-Reported Medication Allergies Associated With Worse Hip Outcome Scores Prior to Hip Arthroscopy?

PubMed

Sochacki, Kyle R; Jack, Robert A; Bekhradi, Arya; Delgado, Domenica; McCulloch, Patrick C; Harris, Joshua D

2018-06-01

To determine if there are significant differences in preoperative patient-reported outcome (PRO) scores in patients with and without self-reported medication allergies undergoing hip arthroscopy. Consecutive subjects undergoing hip arthroscopy for femoroacetabular impingement (FAI) syndrome by a single surgeon were retrospectively reviewed. PROs were collected within 6 weeks of the date of surgery. PROs included International Hip Outcome Tool (iHOT-12), Hip Outcome Score (HOS), and Short-Form (SF-12) scores. Allergies to medications were self-reported preoperatively within 6 weeks of the date of surgery. Patient demographics were recorded. Bivariate correlations and multivariate regression models were calculated to identify associations with baseline hip outcome scores. Two hundred twelve subjects were analyzed (56% female, mean age 35.1 ± 13.2 years). Seventy-two subjects (34%) self-reported allergies (range 1-10; 41 subjects had 1 allergy; 14 subjects had 2; 8 subjects had 3; 2 subjects had 4; 7 subjects had 5 or more). The most commonly reported allergies included penicillin (18), sulfa (13), and codeine (11). Female gender was significantly correlated with number of allergies (Pearson correlation coefficient, 0.188; P < .001). SF-12 Mental Component Score (MCS) was significantly correlated with HOS-ADL (Pearson correlation coefficient, 0.389; P < .001), HOS-SSS (Pearson correlation coefficient, 0.251; P < .001), and iHOT-12 (Pearson correlation coefficient, 0.385; P < .001). There was no significant correlation between number of allergies and all hip PROs. In all multivariate models, the SF-12 MCS had the strongest association with HOS-ADL, HOS-SSS, and iHOT-12 (P < .001 for all). Allergies were not significantly associated with any hip PROs. In patients undergoing hip arthroscopy for FAI syndrome, self-reported medication allergies are not significantly associated with preoperative patient-reported hip outcome scores. Level III, retrospective comparative case series. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

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.

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.

Mental Health Has a Stronger Association with Patient-Reported Shoulder Pain and Function Than Tear Size in Patients with Full-Thickness Rotator Cuff Tears.

PubMed

Wylie, James D; Suter, Thomas; Potter, Michael Q; Granger, Erin K; Tashjian, Robert Z

2016-02-17

Patient-reported outcome measures have increasingly accompanied objective examination findings in the evaluation of orthopaedic interventions. Our objective was to determine whether a validated measure of mental health (Short Form-36 Mental Component Summary [SF-36 MCS]) or measures of tear severity on magnetic resonance imaging were more strongly associated with self-assessed shoulder pain and function in patients with symptomatic full-thickness rotator cuff tears. One hundred and sixty-nine patients with full-thickness rotator cuff tears were prospectively enrolled. Patients completed the Short Form-36, visual analog scales for shoulder pain and function, the Simple Shoulder Test (SST), and the American Shoulder and Elbow Surgeons (ASES) instrument at the time of diagnosis. Shoulder magnetic resonance imaging examinations were reviewed to document the number of tendons involved, tear size, tendon retraction, and tear surface area. Age, sex, body mass index, number of medical comorbidities, smoking status, and Workers' Compensation status were recorded. Bivariate correlations and multivariate regression models were calculated to identify associations with baseline shoulder scores. The SF-36 MCS had the strongest correlation with the visual analog scale for shoulder pain (Pearson correlation coefficient, -0.48; p < 0.001), the visual analog scale for shoulder function (Pearson correlation coefficient, -0.33; p < 0.001), the SST (Pearson correlation coefficient, 0.37; p < 0.001), and the ASES score (Pearson correlation coefficient, 0.51; p < 0.001). Tear severity only correlated with the visual analog scale for shoulder function; the Pearson correlation coefficient was 0.19 for tear size (p = 0.018), 0.18 for tendon retraction (p = 0.025), 0.18 for tear area (p = 0.022), and 0.20 for the number of tendons involved (p = 0.011). Tear severity did not correlate with other scores in bivariate correlations (all p > 0.05). In all multivariate models, the SF-36 MCS had the strongest association with the visual analog scale for shoulder pain, the visual analog scale for shoulder function, the SST, and the ASES score (all p < 0.001). Patient mental health may play an influential role in patient-reported pain and function in patients with full-thickness rotator cuff tears. Further studies are needed to determine its effect on the outcome of the treatment of rotator cuff disease. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Predicting adult pulmonary ventilation volume and wearing complianceby on-board accelerometry during personal level exposure assessments

NASA Astrophysics Data System (ADS)

Rodes, C. E.; Chillrud, S. N.; Haskell, W. L.; Intille, S. S.; Albinali, F.; Rosenberger, M. E.

2012-09-01

BackgroundMetabolic functions typically increase with human activity, but optimal methods to characterize activity levels for real-time predictions of ventilation volume (l min-1) during exposure assessments have not been available. Could tiny, triaxial accelerometers be incorporated into personal level monitors to define periods of acceptable wearing compliance, and allow the exposures (μg m-3) to be extended to potential doses in μg min-1 kg-1 of body weight? ObjectivesIn a pilot effort, we tested: 1) whether appropriately-processed accelerometer data could be utilized to predict compliance and in linear regressions to predict ventilation volumes in real-time as an on-board component of personal level exposure sensor systems, and 2) whether locating the exposure monitors on the chest in the breathing zone, provided comparable accelerometric data to other locations more typically utilized (waist, thigh, wrist, etc.). MethodsPrototype exposure monitors from RTI International and Columbia University were worn on the chest by a pilot cohort of adults while conducting an array of scripted activities (all <10 METS), spanning common recumbent, sedentary, and ambulatory activity categories. Referee Wocket accelerometers that were placed at various body locations allowed comparison with the chest-located exposure sensor accelerometers. An Oxycon Mobile mask was used to measure oral-nasal ventilation volumes in-situ. For the subset of participants with complete data (n = 22), linear regressions were constructed (processed accelerometric variable versus ventilation rate) for each participant and exposure monitor type, and Pearson correlations computed to compare across scenarios. ResultsTriaxial accelerometer data were demonstrated to be adequately sensitive indicators for predicting exposure monitor wearing compliance. Strong linear correlations (R values from 0.77 to 0.99) were observed for all participants for both exposure sensor accelerometer variables against ventilation volume for recumbent, sedentary, and ambulatory activities with MET values ˜<6. The RTI monitors mean R value of 0.91 was slightly higher than the Columbia monitors mean of 0.86 due to utilizing a 20 Hz data rate instead of a slower 1 Hz rate. A nominal mean regression slope was computed for the RTI system across participants and showed a modest RSD of +/-36.6%. Comparison of the correlation values of the exposure monitors with the Wocket accelerometers at various body locations showed statistically identical regressions for all sensors at alternate hip, ankle, upper arm, thigh, and pocket locations, but not for the Wocket accelerometer located at the dominant side wrist location (R = 0.57; p = 0.016). ConclusionsEven with a modest number of adult volunteers, the consistency and linearity of regression slopes for all subjects were very good with excellent within-person Pearson correlations for the accelerometer versus ventilation volume data. Computing accelerometric standard deviations allowed good sensitivity for compliance assessments even for sedentary activities. These pilot findings supported the hypothesis that a common linear regression is likely to be usable for a wider range of adults to predict ventilation volumes from accelerometry data over a range of low to moderate energy level activities. The predicted volumes would then allow real-time estimates of potential dose, enabling more robust panel studies. The poorer correlation in predicting ventilation rate for an accelerometer located on the wrist suggested that this location should not be considered for predictions of ventilation volume.

A comparison of ROC inferred from FROC and conventional ROC

NASA Astrophysics Data System (ADS)

McEntee, Mark F.; Littlefair, Stephen; Pietrzyk, Mariusz W.

2014-03-01

This study aims to determine whether receiver operating characteristic (ROC) scores inferred from free-response receiver operating characteristic (FROC) were equivalent to conventional ROC scores for the same readers and cases. Forty-five examining radiologists of the American Board of Radiology independently reviewed 47 PA chest radiographs under at least two conditions. Thirty-seven cases had abnormal findings and 10 cases had normal findings. Half the readers were asked to first locate any visualized lung nodules, mark them and assign a level of confidence [the FROC mark-rating pair] and second give an overall to the entire image on the same scale [the ROC score]. The second half of readers gave the ROC rating first followed by the FROC mark-rating pairs. A normal image was represented with number 1 and malignant lesions with numbers 2-5. A jackknife free-response receiver operating characteristic (JAFROC), and inferred ROC (infROC) was calculated from the mark-rating pairs using JAFROC V4.1 software. ROC based on the overall rating of the image calculated using DBM MRMC software, which was also used to compare infROC and ROC AUCs treating the methods as modalities. Pearson's correlations coefficient and linear regression were used to examine their relationship using SPSS, version 21.0; (SPSS, Chicago, IL). The results of this study showed no significant difference between the ROC and Inferred ROC AUCs (p≤0.25). While Pearson's correlation coefficient was 0.7 (p≤0.01). Inter-reader correlation calculated from Obuchowski- Rockette covariance's ranged from 0.43-0.86 while intra-reader agreement was greater than previously reported ranging from 0.68-0.82.

Sleep quality and spiritual well-being in hemodialysis patients.

PubMed

Eslami, Ahmad Ali; Rabiei, Leili; Khayri, Freidoon; Rashidi Nooshabadi, Mohammad Reza; Masoudi, Reza

2014-07-01

Sleep disorders are considered as one of the most important problems in hemodialysis patients, making their everyday life a serious hazard. Sleep quality of hemodialysis patients and consequences of sleep disorders on other aspects of health such as spiritual well-being are important issues. This study examined the relationship between spiritual well-being and quality of sleep in hemodialysis patients in Isfahan, Iran. This study was a correlation research, carried out on 190 hemodialysis patients. Data collection Questionnaires included demographic forms, Pittsburgh sleep quality index (PSQI), and Ellison and Paloutzian spiritual well-being scale. Data were analyzed using descriptive and inferential statistics (Pearson correlation and linear regression analysis) at P < 0.05 significance level, by SPSS software version 18. Of 190 study participants, 163 (85.78%) with scores more than five index had sleep disturbances and 27 (14.12%) had no sleep disturbance; 3 (1.52%) had mild, 163 (85.78%) moderate, and 24 (12.30%) good spiritual health conditions. Pearson correlation test showed significant relationship between the sleep quality items of Pittsburg and spiritual well-being (P < 0.04, r = 0.149). Through the regression analyses of spiritual health, family, education, financial status, marital status, occupation, and use of sleep medication, the predictive power of these variables was found 0.417% and prediction of spiritual well-being was more than others (ß = 0.209). Considering bed as one of the most vital physical, mental, and emotional needs, it is very important in mental and spiritual well-being of hemodialysis patients as an influencing factor in mental relaxation and reducing disease tensions. Paying attention to sleep quality and spiritual well-being components of hemodialysis patients in formulating and promoting healthcare programs is recommended.

Dry eye symptoms align more closely to non-ocular conditions than to tear film parameters.

PubMed

Galor, Anat; Felix, Elizabeth R; Feuer, William; Shalabi, Nabeel; Martin, Eden R; Margolis, Todd P; Sarantopoulos, Constantine D; Levitt, Roy C

2015-08-01

To evaluate the relationship between dry eye symptoms, non-ocular conditions and tear film parameters. Cross-sectional study. The study population consisted of patients who were seen in the Miami Veterans Affairs eye clinic. Patients filled out standardised questionnaires assessing dry eye symptoms (dry eye questionnaire 5 (DEQ5) and ocular surface disease index (OSDI)), non-ocular pain, depression and post-traumatic stress disorder (PTSD), and also underwent measurement of tear film parameters. Correlations between dry eye symptoms and non-ocular conditions as compared with tear film parameters. 136 patients with a mean age of 65 (SD 11) years participated in the study. All correlations between the dry eye questionnaire scores (DEQ5 and OSDI) and (A) self-reported non-ocular pain measures (numerical rating scale and pain history), (B) depression and (C) PTSD were significant and moderate in strength (Pearson's coefficient 0.24 to 0.60, p<0.01 for all). All correlations between the dry eye questionnaires and tear film measures were weak (Pearson's coefficient -0.10 to 0.18) and most were not significant. Multivariable linear regression analyses revealed that PTSD and non-ocular pain more closely associated with dry eye symptoms than did tear film parameters. Specifically, non-ocular pain and PTSD accounted for approximately 36% of the variability in DEQ5 scores (R=0.60) and approximately 40% of variability in OSDI scores (R=0.64). Of note, none of the tear parameters remained significantly associated with dry eye symptoms in either model. Dry eye symptoms more closely align to non-ocular pain, depression and PTSD than to tear film parameters. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Could CCI or FBCI Fully Eliminate the Impact of Curve Flexibility When Evaluating the Surgery Outcome for Thoracic Curve Idiopathic Scoliosis Patient? A Retrospective Study

PubMed Central

Ni, Haijian; Zhu, Xiaodong; Li, Ming

2015-01-01

Purpose To clarify if CCI or FBCI could fully eliminate the influence of curve flexibility on the coronal correction rate. Methods We reviewed medical record of all thoracic curve AIS cases undergoing posterior spinal fusion with all pedicle screw systems from June 2011 to July 2013. Radiographical data was collected and calculated. Student t test, Pearson correlation analysis and linear regression analysis were used to analyze the data. Results 60 were included in this study. The mean age was 14.7y (10-18y) with 10 males (17%) and 50 females (83%). The average Risser sign was 2.7. The mean thoracic Cobb angle before operation was 51.9°. The mean bending Cobb angle was 27.6° and the mean fulcrum bending Cobb angle was 17.4°. The mean Cobb angle at 2 week after surgery was 16.3°. The Pearson correlation coefficient r between CCI and BFR was -0.856(P<0.001), and between FBCI and FFR was -0.728 (P<0.001). A modified FBCI (M-FBCI) = (CR-0.513)/BFR or a modified CCI (M-CCI) = (CR-0.279)/FFR was generated by curve estimation has no significant correlation with FFR (r=-0.08, p=0.950) or with BFR (r=0.123, p=0.349). Conclusions Fulcrum-bending radiographs may better predict the outcome of AIS coronal correction than bending radiographs in thoracic curveAIS patients. Neither CCI nor FBCI can fully eliminate the impact of curve flexibility on the outcome of correction. A modified CCI or FBCI can better evaluating the corrective effects of different surgical techniques or instruments. PMID:25984945

Could CCI or FBCI Fully Eliminate the Impact of Curve Flexibility When Evaluating the Surgery Outcome for Thoracic Curve Idiopathic Scoliosis Patient? A Retrospective Study.

PubMed

Yang, Changwei; Sun, Xiaofei; Li, Chao; Ni, Haijian; Zhu, Xiaodong; Yang, Shichang; Li, Ming

2015-01-01

To clarify if CCI or FBCI could fully eliminate the influence of curve flexibility on the coronal correction rate. We reviewed medical record of all thoracic curve AIS cases undergoing posterior spinal fusion with all pedicle screw systems from June 2011 to July 2013. Radiographical data was collected and calculated. Student t test, Pearson correlation analysis and linear regression analysis were used to analyze the data. 60 were included in this study. The mean age was 14.7 y (10-18 y) with 10 males (17%) and 50 females (83%). The average Risser sign was 2.7. The mean thoracic Cobb angle before operation was 51.9°. The mean bending Cobb angle was 27.6° and the mean fulcrum bending Cobb angle was 17.4°. The mean Cobb angle at 2 week after surgery was 16.3°. The Pearson correlation coefficient r between CCI and BFR was -0.856(P<0.001), and between FBCI and FFR was -0.728 (P<0.001). A modified FBCI (M-FBCI) = (CR-0.513)/BFR or a modified CCI (M-CCI) = (CR-0.279)/FFR was generated by curve estimation has no significant correlation with FFR (r=-0.08, p=0.950) or with BFR (r=0.123, p=0.349). Fulcrum-bending radiographs may better predict the outcome of AIS coronal correction than bending radiographs in thoracic curveAIS patients. Neither CCI nor FBCI can fully eliminate the impact of curve flexibility on the outcome of correction. A modified CCI or FBCI can better evaluating the corrective effects of different surgical techniques or instruments.

The osmotic tolerance of boar spermatozoa and its usefulness as sperm quality parameter.

PubMed

Yeste, Marc; Briz, Mailo; Pinart, Elisabeth; Sancho, Sílvia; Bussalleu, Eva; Bonet, Sergi

2010-06-01

Predicting the fertility outcome of ejaculates is very important in the field of porcine reproduction. The aims of this study were to determine the effects of different osmotic treatments on boar spermatozoa and to correlate them with fertility and prolificacy, assessed as non-return rates within 60 days (NRR(60d)) of the first inseminations, and litter size (LS), respectively. Sperm samples (n=100) from one hundred healthy Piétrain boars were used to assess 48 treatments combining different osmolalities (ranged between 100 and 4000 mOsm kg(-1)), different compounds used to prepare anisotonic solutions, and two different modalities: return and non-return to isotonic conditions. Sperm quality was evaluated before and after applying the treatments on the basis of analyses of sperm viability, motility, morphology and percentages of acrosome-intact spermatozoa. Statistical analyses were performed using a one-way ANOVA and post hoc Tukey's test, linear regression analyses (Pearson correlation and multiple regression) and Jackknife cross-validation. Although three conventional parameters: sperm viability, sperm morphology and the percentages of acrosome-intact spermatozoa were significantly correlated with NRR(60d) and with LS, their respective osmotic tolerance parameters (defined for each parameter and treatment regarding with negative control) presented a higher Pearson coefficient with both fertility and prolificacy in three treatments (150 mOsm kg(-1) with non-return to isotonic conditions, 200 mOsm kg(-1) with return and 500 mOsm kg(-1) using sodium citrate and non-return to isotonic conditions). We conclude that osmotic resistance in sperm viability, sperm morphology and acrosome-intactness in the treatments mentioned above could be assessed along with classical parameters to better predict the fertilising ability of a given ejaculate. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Patient experiences of caring and person-centredness are associated with perceived nursing care quality.

PubMed

Edvardsson, David; Watt, Elizabeth; Pearce, Frances

2017-01-01

To explore the extent to which patient ratings of perceived caring and person-centredness are associated with perceived nursing care quality in an acute hospital sample of inpatients. Self-reported patient experiences have had limited attention in conceptualizations of healthcare quality as described in policy and national standards, as well as in health and nursing care practice. The impact of central nursing concepts such as caring and person-centredness on patient ratings of nursing care quality is largely unknown. A descriptive non-experimental correlational design was used to collect and analyse data from a sample of Australian acute hospital inpatients (n = 210) in December 2012. The study collected self-report patient data through a study survey including demographic data and the Caring Behaviours Inventory, the Person-centred Climate Questionnaire, the SF-36 and the Distress thermometer. Descriptive statistics together with Pearson correlation and hierarchical linear regression were used. Perceived caring behaviours of staff and the person-centredness of wards were significantly associated with nursing care quality as evidenced by Pearson correlations being significant and exceeding the pre-set cut-off of r > 0·5. Staff caring behaviours and ward person-centredness also accounted for more than half of the total variance in perceived nursing care quality as evidenced by the final regression model. Knowledgeable and communicable staff, timeliness of assistance and environmental support stood out as most significantly related to patient perceived nursing care quality. Patient experiences of caring and person-centredness seem to have an influential role in the extent to which patients experience the quality of nursing care. Knowledgeable and communicable staff, timeliness of assistance and environmental support stand out as most significantly related to patient-perceived nursing care quality. © 2016 John Wiley & Sons Ltd.

Prevalence of Psychiatric Morbidity Among Undergraduate Students of a Dental College in West Bengal.

PubMed

Makhal, Manabendra; Ray, Pradip Kumar; Ray Bhattacharya, Sampa; Ghosh, Subhankar; Majumder, Uttam; DE, Shantanu; Bandyopadhyay, Gautam Kumar; Bera, Nirmal Kumar

2015-07-01

Stresses of medical course affects the academic performance as well as physical and psychological health of the students negatively. In the present day scenario every one of us has vulnerability to have psychiatric morbidity. Like other young adults, undergraduate dental students are similarly vulnerable to turmoil due to academic and social stresses, which often hamper the educational achievement. Early detection and treatment of psychological morbidities shorten the suffering leading to less social impairment in long term. The aim of this study was to assess the psychiatric morbidity of dental students and the factors affecting their mental health. This cross sectional, descriptive and correlation study was conducted in North Bengal Dental College, a rural dental college of West Bengal, India. The study sample consisted of a total of 89 dental students. The student enrollment was done by "simple random sampling method". The semi-structured proforma and the General Health Questionnaire (GHQ)-28 were used to collect data and to assess the psychiatric morbidity. Pearson's correlation followed by multivariate linear regression analysis was done to assess the effect of academic achievement, positive and negative event on the GHQ total score. The overall mean GHQ total score in the study population was 5.33, with a SD of 4.85 which was above the cutoff (>4) score. Karl Pearson correlation co-efficient r-values for GHQ total score with 'academic achievement' and 'negative events' score were 0.718 and 0.628 respectively and p-values were 0.001 and 0.001. The poor academic performance and negative events had strong impact on psychological morbidity of dental students. The findings of our study can't be generalized for all undergraduate dental student due to small sample size and non inclusion of many other variables.

Psychological Characteristics and Traits for Finding Benefit From Prostate Cancer: Correlates and Predictors.

PubMed

Pascoe, Elizabeth C; Edvardsson, David

Although beginning evidence suggests that the capacity to derive benefit from cancer-associated experiences may be influenced by some individual psychological characteristics and traits, little is known about predictors for finding benefit from prostate cancer. The aim of this study was to explore the correlates and predictors for finding benefit from prostate cancer among a sample of men undergoing androgen deprivation. Pearson correlation and multiple linear regression modeling were performed on data collected in an acute tertiary hospital outpatient setting (N = 209) between July 2011 and December 2013 to determine correlates and predictors for finding benefit from prostate cancer. Multiple linear regression modeling showed that while the 6 predictors of self-reported coping, depression, anxiety, distress, resilience, and hope explained 38% of the variance in finding benefit, coping provided the strongest and statistically significant predictive contribution. Self-reported coping was strongly predictive of finding benefit from prostate cancer, but questions remain about if subtypes of coping strategies can be more or less predictive of finding benefit. Self-reported levels of depression, anxiety, distress, resilience, and hope had a less predictive and nonsignificant role in finding benefit from prostate cancer and raise questions about their function in this subpopulation. The findings suggest that coping strategies can maximize finding benefit from prostate cancer. Knowledge of influential coping strategies for finding benefit from prostate cancer can be immensely valuable to support men in rebuilding positive meaning amid a changed illness reality. Developing practice initiatives that foster positive meaning-making coping strategies seems valuable.

Constructing a bivariate distribution function with given marginals and correlation: application to the galaxy luminosity function

NASA Astrophysics Data System (ADS)

Takeuchi, Tsutomu T.

2010-08-01

We provide an analytic method to construct a bivariate distribution function (DF) with given marginal distributions and correlation coefficient. We introduce a convenient mathematical tool, called a copula, to connect two DFs with any prescribed dependence structure. If the correlation of two variables is weak (Pearson's correlation coefficient |ρ| < 1/3), the Farlie-Gumbel-Morgenstern (FGM) copula provides an intuitive and natural way to construct such a bivariate DF. When the linear correlation is stronger, the FGM copula cannot work anymore. In this case, we propose using a Gaussian copula, which connects two given marginals and is directly related to the linear correlation coefficient between two variables. Using the copulas, we construct the bivariate luminosity function (BLF) and discuss its statistical properties. We focus especially on the far-infrared-far-ulatraviolet (FUV-FIR) BLF, since these two wavelength regions are related to star-formation (SF) activity. Though both the FUV and FIR are related to SF activity, the univariate LFs have a very different functional form: the former is well described by the Schechter function whilst the latter has a much more extended power-law-like luminous end. We construct the FUV-FIR BLFs using the FGM and Gaussian copulas with different strengths of correlation, and examine their statistical properties. We then discuss some further possible applications of the BLF: the problem of a multiband flux-limited sample selection, the construction of the star-formation rate (SFR) function, and the construction of the stellar mass of galaxies (M*)-specific SFR (SFR/M*) relation. The copulas turn out to be a very useful tool to investigate all these issues, especially for including complicated selection effects.

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…

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.

Bone mineral density and correlation factor analysis in normal Taiwanese children.

PubMed

Shu, San-Ging

2007-01-01

Our aim was to establish reference data and linear regression equations for lumbar bone mineral density (BMD) in normal Taiwanese children. Several influencing factors of lumbar BMD were investigated. Two hundred fifty-seven healthy children were recruited from schools, 136 boys and 121 girls, aged 4-18 years were enrolled on a voluntary basis with written consent. Their height, weight, blood pressure, puberty stage, bone age and lumbar BMD (L2-4) by dual energy x-ray absorptiometry (DEXA) were measured. Data were analyzed using Pearson correlation and stepwise regression tests. All measurements increased with age. Prior to age 8, there was no gender difference. Parameters such as height, weight, and bone age (BA) in girls surpassed boys between ages 8-13 without statistical significance (p> or =0.05). This was reversed subsequently after age 14 in height (p<0.05). BMD difference had the same trend but was not statistically significant either. The influencing power of puberty stage and bone age over BMD was almost equal to or higher than that of height and weight. All the other factors correlated with BMD to variable powers. Multiple linear regression equations for boys and girls were formulated. BMD reference data is provided and can be used to monitor childhood pathological conditions. However, BMD in those with abnormal bone age or pubertal development could need modifications to ensure accuracy.

Calculation of Hammett Equation parameters for some N,N‧-bis (substituted-phenyl)-1,4-quinonediimines by density functional theory

NASA Astrophysics Data System (ADS)

Sein, Lawrence T.

2011-08-01

Hammett parameters σ' were determined from vertical ionization potentials, vertical electron affinities, adiabatic ionization potentials, adiabatic electron affinities, HOMO, and LUMO energies of a series of N, N' -bis (3',4'-substituted-phenyl)-1,4-quinonediimines computed at the B3LYP/6-311+G(2d,p) level on B3LYP/6-31G ∗ molecular geometries. These parameters were then least squares fit as a function of literature Hammett parameters. For N, N' -bis (4'-substituted-phenyl)-1,4-quinonediimines, the least squares fits demonstrated excellent linearity, with the square of Pearson's correlation coefficient ( r2) greater than 0.98 for all isomers. For N, N' -bis (3'-substituted-3'-aminophenyl)-1,4-quinonediimines, the least squares fits were less nearly linear, with r2 approximately 0.70 for all isomers when derived from calculated vertical ionization potentials, but those from calculated vertical electron affinities usually greater than 0.90.

Transcultural adaptation and psychometric properties of Spanish version of Pregnancy Physical Activity Questionnaire: the PregnActive project.

PubMed

Oviedo-Caro, Miguel Ángel; Bueno-Antequera, Javier; Munguía-Izquierdo, Diego

2018-03-19

To transculturally adapt the Spanish version of Pregnancy Physical Activity Questionnaire (PPAQ) analyzing its psychometric properties. The PPAQ was transculturally adapted into Spanish. Test-retest reliability was evaluated in a subsample of 109 pregnant women. The validity was evaluated in a sample of 208 pregnant women who answered the questionnaire and wore the multi-sensor monitor for 7 valid days. The reliability (intraclass correlation coefficient), concordance (concordance correlation coefficient), correlation (Pearson correlation coefficient), agreement (Bland-Altman plots) and relative activity levels (Jonckheere-Terpstra test) between both administrations and methods were examined. Intraclass correlation coefficients between both administrations were good for all categories except transportation. A low but significant correlation was found for total activity (light and above) whereas no correlation was found for other intensities between both methods. Relative activity levels analysis showed a significant linear trend for increased total activity between both methods. Spanish version of PPAQ is a brief and easily interpretable questionnaire with good reliability and ability to rank individuals, and poor validity compared with multi-sensor monitor. The use of PPAQ provides information of pregnancy-specific activities in order to establish physical activity levels of pregnant women and adapt health promotion interventions. Copyright © 2018 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

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.

Effectiveness of sonography assisted minimal invasive plate osteosynthesis (MIPO) compare with fluoroscope assisted in femoral shaft fracture: A cadaveric study.

PubMed

Saengsin, Jirawat; Vaseenon, Tanawat; Pattamapaspong, Nuttaya; Kritsaneephaiboon, Apipop

2017-08-01

A minimal invasive plate osteosynthesis (MIPO) has an advantage of biological soft tissue preservation that consists of preserving bony blood supply, fracture hematoma and less soft tissue damage which leads to decreasing of infection rate and rapid bone healing. However, the radiation exposure is still a disadvantage of this technique. A sonography that provides dynamic real time imaging may be used as an alternative technique for assisting MIPO. The aim of this study was to compare the effectiveness of MIPO in femoral shaft fracture between the sonography assisted and the fluoroscopy assisted. Twenty-eight cadaveric limbs were subjected to create femoral shaft fracture. Then, sonography assisted reduction with temporary external fixation and MIPO were performed. Images of the sonography and the fluoroscopy were recorded including before reduction, after reduction and after MIPO in order to identify fracture displacements in anteroposterior and mediolateral directions. Moreover, the anterior and posterior distances from edge of the bone to the plate were measured to confirm plate position. The effectiveness of this technique was defined as the proper plate position and acceptable alignment after fixation. All distances from the sonography and the fluoroscopy were also analyzed and compared using Pearson correlation and Bland-Altman method to assess the agreements between two tests. All of the subjects were met the criteria for acceptable alignment. We found only three femoral shaft fracture (11%) operated with MIPO by sonography assisted that showed slipped plate off femoral bones. According to Pearson correlation, there were good to excellent agreements in term of measuring fracture displacement before (Pearson Correlation >0.7) and after reduction (Pearson Correlation >0.7) between these two tests. There was moderate agreement regarding to evaluation of plate position (Pearson Correlation 03.-0.7). When we compared two methods of measurement using Bland-Altman plot, there were no statistical significant difference (P<0.05). Images from the sonography could provide visualization of the fracture during reduction and MIPO as accurately as the radiography. Thus, the sonography assisted MIPO in femoral shaft fracture can be done effectively comparing with radiographic assisted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Serum biomarkers of habitual coffee consumption may provide insight into the mechanism underlying the association between coffee consumption and colorectal cancer.

PubMed

Guertin, Kristin A; Loftfield, Erikka; Boca, Simina M; Sampson, Joshua N; Moore, Steven C; Xiao, Qian; Huang, Wen-Yi; Xiong, Xiaoqin; Freedman, Neal D; Cross, Amanda J; Sinha, Rashmi

2015-05-01

Coffee intake may be inversely associated with colorectal cancer; however, previous studies have been inconsistent. Serum coffee metabolites are integrated exposure measures that may clarify associations with cancer and elucidate underlying mechanisms. Our aims were 2-fold as follows: 1) to identify serum metabolites associated with coffee intake and 2) to examine these metabolites in relation to colorectal cancer. In a nested case-control study of 251 colorectal cancer cases and 247 matched control subjects from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we conducted untargeted metabolomics analyses of baseline serum by using ultrahigh-performance liquid-phase chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Usual coffee intake was self-reported in a food-frequency questionnaire. We used partial Pearson correlations and linear regression to identify serum metabolites associated with coffee intake and conditional logistic regression to evaluate associations between coffee metabolites and colorectal cancer. After Bonferroni correction for multiple comparisons (P = 0.05 ÷ 657 metabolites), 29 serum metabolites were positively correlated with coffee intake (partial correlation coefficients: 0.18-0.61; P < 7.61 × 10(-5)); serum metabolites most highly correlated with coffee intake (partial correlation coefficients >0.40) included trigonelline (N'-methylnicotinate), quinate, and 7 unknown metabolites. Of 29 serum metabolites, 8 metabolites were directly related to caffeine metabolism, and 3 of these metabolites, theophylline (OR for 90th compared with 10th percentiles: 0.44; 95% CI: 0.25, 0.79; P-linear trend = 0.006), caffeine (OR for 90th compared with 10th percentiles: 0.56; 95% CI: 0.35, 0.89; P-linear trend = 0.015), and paraxanthine (OR for 90th compared with 10th percentiles: 0.58; 95% CI: 0.36, 0.94; P-linear trend = 0.027), were inversely associated with colorectal cancer. Serum metabolites can distinguish coffee drinkers from nondrinkers; some caffeine-related metabolites were inversely associated with colorectal cancer and should be studied further to clarify the role of coffee in the cause of colorectal cancer. The Prostate, Lung, Colorectal, and Ovarian trial was registered at clinicaltrials.gov as NCT00002540. © 2015 American Society for Nutrition.

[Concordance of glomerular filtration rate with creatinine clearance in 24-hour urine and Schwartz and Schwartz updated].

PubMed

Salazar-Gutiérrez, María Luisa; Ochoa-Ponce, Cristina; Lona-Reyes, Juan Carlos; Gutiérrez-Íñiguez, Sara Ivonne

Reference methods for the quantification of the glomerular filtration rate (GFR) are difficult to use in clinical practice; formulas for evaluating GFR based on serum creatinine (SCr) and/or creatinine clearance are used. The aim of this study was to quantify the correlation and concordance of GFR with creatinine clearance in 24-hour urine (GFR24) and Schwartz and Schwartz updated formulas. Cross-sectional study involving healthy pediatric patients and with chronic kidney disease (CKD) from 5 to 16.9 years. Linear correlation between GFR 24 and two formulas was evaluated with the Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC). We studied 134 patients, of which 59.7% were male. Mean age was 10.8 years. The average GFR24 was 140.34ml/min/1.73m 2 ; 34.3% (n=46) had GFR <90ml/min/1.73m 2 . Moderate linear correlation between GFR24 and Schwartz (r= 0.63) and Schwartz updated (r= 0.65) formulas was observed. There was good concordance between the GFR24 and Schwartz (ICC= 0.77) and updated Schwartz (ICC= 0.77) formulas. Schwartz classical formula in patients with GFR24 ≥ 90ml/min/1.73m 2 estimated higher values, while Schwartz updated underestimated values. There is moderate correlation and good concordance between the GFR24 and Schwartz and Schwartz updated formulas. The concordance was better in patients with obesity and lower in women, patients with hyperfiltration and normal weight. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Outcomes and Disability After Massive Proximal Upper Extremity Reconstruction in a Resource-Limited Setting.

PubMed

Giladi, Aviram M; Shanmugakrishnan, R Raja; Venkatramani, Hari; Raja Sekaran, S; Chung, Kevin C; Sabapathy, S Raja

2017-06-01

At Ganga Hospital in Coimbatore, India, a unique approach is applied to treat massive upper limb injuries. However, long-term outcomes of complex reconstruction performed in the resource-limited setting are not known. This hinders understanding of outcomes and disability from these injuries and prevents systematically addressing care delivery around upper extremity trauma in the developing world. This project aims to analyze the details of the unique Ganga Hospital reconstruction experience and use patient-reported outcome measures for the first time in this patient population to evaluate post-injury recovery and disability . Forty-six patients were evaluated 6 months or more after massive proximal upper extremity reconstruction at Ganga Hospital. Patients completed functional tests, Jebsen-Taylor test (JTT), and patient-reported outcomes (PROs)-Michigan Hand Questionnaire (MHQ), Disability of Arm, Shoulder, and Hand questionnaire (DASH), and Short-Form 36 (SF-36). Correlations between metrics were assessed with Pearson's correlation coefficients. Linear regression modeling evaluated associations between severity, reconstruction, and outcomes. MHQ and DASH results correlated with functional test performance, JTT performance, and SF-36 scores (Pearson's coefficients all ≥0.33, p ≤ 0.05). In this cohort, mean MHQ score was 79 ± 15 and mean DASH score was 13 ± 15, which are not significantly different than scores for long-term outcomes after other complex upper extremity procedures. The following factors predicted PROs and functional performance after reconstruction: extent of soft tissue reconstruction, multi-segmental ulna fractures, median nerve injury, and ability for patients to return to work and maintain their job after injury. Complex proximal upper extremity salvage can be performed in the resource-limited setting with excellent long-term functional and patient-reported outcomes. PRO questionnaires are useful for reporting outcomes that correlate to functional and sensory testing and may be used to assess post-traumatic disability.

Organizational correlates of implementation of colocation of mental health and primary care in the Veterans Health Administration.

PubMed

Guerrero, Erick G; Heslin, Kevin C; Chang, Evelyn; Fenwick, Karissa; Yano, Elizabeth

2015-07-01

This study explored the role of organizational factors in the ability of Veterans Health Administration (VHA) clinics to implement colocated mental health care in primary care settings (PC-MH). The study used data from the VHA Clinical Practice Organizational Survey collected in 2007 from 225 clinic administrators across the United States. Clinic degree of implementation of PC-MH was the dependent variable, whereas independent variables included policies and procedures, organizational context, and leaders' perceptions of barriers to change. Pearson bivariate correlations and multivariable linear regression were used to test hypotheses. Results show that depression care training for primary care providers and clinics' flexibility and participation were both positively correlated with implementation of PC-MH. However, after accounting for other factors, regressions show that only training primary care providers in depression care was marginally associated with degree of implementation of PC-MH (p = 0.051). Given the importance of this topic for implementing integrated care as part of health care reform, these null findings underscore the need to improve theory and testing of more proximal measures of colocation in future work.

Organizational Correlates of Implementation of Colocation of Mental Health and Primary Care in the Veterans Health Administration

PubMed Central

Guerrero, Erick G.; Heslin, Kevin C.; Chang, Evelyn; Fenwick, Karissa; Yano, Elizabeth

2014-01-01

This study explored the role of organizational factors in the ability of Veterans Health Administration (VHA) clinics to implement colocated mental health care in primary care settings (PC-MH). The study used data from the VHA Clinical Practice Organizational Survey collected in 2007 from 225 clinic administrators across the United States. Clinic degree of implementation of PC-MH was the dependent variable, whereas independent variables included policies and procedures, organizational context, and leaders’ perceptions of barriers to change. Pearson bivariate correlations and multivariable linear regression were used to test hypotheses. Results show that depression care training for primary care providers and clinics’ flexibility and participation were both positively correlated with implementation of PC-MH. However, after accounting for other factors, regressions show that only training primary care providers in depression care was marginally associated with degree of implementation of PC-MH (p = 0.051). Given the importance of this topic for implementing integrated care as part of health care reform, these null findings underscore the need to improve theory and testing of more proximal measures of colocation in future work. PMID:25096986

A null model for Pearson coexpression networks.

PubMed

Gobbi, Andrea; Jurman, Giuseppe

2015-01-01

Gene coexpression networks inferred by correlation from high-throughput profiling such as microarray data represent simple but effective structures for discovering and interpreting linear gene relationships. In recent years, several approaches have been proposed to tackle the problem of deciding when the resulting correlation values are statistically significant. This is most crucial when the number of samples is small, yielding a non-negligible chance that even high correlation values are due to random effects. Here we introduce a novel hard thresholding solution based on the assumption that a coexpression network inferred by randomly generated data is expected to be empty. The threshold is theoretically derived by means of an analytic approach and, as a deterministic independent null model, it depends only on the dimensions of the starting data matrix, with assumptions on the skewness of the data distribution compatible with the structure of gene expression levels data. We show, on synthetic and array datasets, that the proposed threshold is effective in eliminating all false positive links, with an offsetting cost in terms of false negative detected edges.

The effects of climate factors on scabies. A 14-year population-based study in Taiwan.

PubMed

Liu, Jui-Ming; Wang, Hsiao-Wei; Chang, Fung-Wei; Liu, Yueh-Ping; Chiu, Feng-Hsiang; Lin, Yi-Chun; Cheng, Kuan-Chen; Hsu, Ren-Jun

2016-01-01

Scabies is a common infectious disease and can cause severe outbreaks if not controlled quickly. Besides personal contact history, environmental factors are also important. This study analyzed the effects of environmental climate factors on the incidence of scabies in Taiwan. We conducted a 14-year nationwide population-based study: a total of 14,883 patients with scabies infestation were enrolled. Monthly climate data were collected from Taiwan's Central Weather Bureau, including data on temperature, relative humidity, total rainfall, total rain days, and total sunshine hours. The linear relationships between these climate factors and scabies infestations or other risk factors were examined by Pearson's correlation analysis. Overall, the incidence of scabies was negatively correlated with temperature (γ = -0.152, p < 0.001), while being positively correlated with humidity (γ = 0.192, p < 0.001). This useful information may provide evidence for lowering humidity at nursing facilities, hospitals, and military camps with scabies infestations, which may help to reduce its spread and prevent outbreaks. © J.-M. Liu et al., published by EDP Sciences, 2016.

Validity and test–retest reliability of a novel simple back extensor muscle strength test

PubMed Central

Harding, Amy T; Weeks, Benjamin Kurt; Horan, Sean A; Little, Andrew; Watson, Steven L; Beck, Belinda Ruth

2017-01-01

Objectives: To develop and determine convergent validity and reliability of a simple and inexpensive clinical test to quantify back extensor muscle strength. Methods: Two testing sessions were conducted, 7 days apart. Each session involved three trials of standing maximal isometric back extensor muscle strength using both the novel test and isokinetic dynamometry. Lumbar spine bone mineral density was examined by dual-energy X-ray absorptiometry. Validation was examined with Pearson correlations (r). Test–retest reliability was examined with intraclass correlation coefficients and limits of agreement. Pearson correlations and intraclass correlation coefficients are presented with corresponding 95% confidence intervals. Linear regression was used to examine the ability of peak back extensor muscle strength to predict indices of lumbar spine bone mineral density and strength. Results: A total of 52 healthy adults (26 men, 26 women) aged 46.4 ± 20.4 years were recruited from the community. A strong positive relationship was observed between peak back extensor strength from hand-held and isokinetic dynamometry (r = 0.824, p < 0.001). For the novel back extensor strength test, short- and long-term reliability was excellent (intraclass correlation coefficient = 0.983 (95% confidence interval, 0.971–0.990), p < 0.001 and intraclass correlation coefficient = 0.901 (95% confidence interval, 0.833–0.943), p < 0.001, respectively). Limits of agreement for short-term repeated back extensor strength measures with the novel back extensor strength protocol were −6.63 to 7.70 kg, with a mean bias of +0.71 kg. Back extensor strength predicted 11% of variance in lumbar spine bone mineral density (p < 0.05) and 9% of lumbar spine index of bone structural strength (p < 0.05). Conclusion: Our novel hand-held dynamometer method to determine back extensor muscle strength is quick, relatively inexpensive, and reliable; demonstrates initial convergent validity in a healthy population; and is associated with bone mass at a clinically important site. PMID:28255442

SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

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

Ma, L; Braunstein, S; Chiu, J

2016-06-15

Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive anmore » EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.« less

Nonlinear and Synchronous Dissolved Organic Matter Dynamics in Streams Across an Agriculture Land Use and Climate Setting

NASA Astrophysics Data System (ADS)

Xenopoulos, M. A.; Vogt, R. J.

2014-12-01

There is now increasing evidence that non-linearity is a common response in ecological systems to pressures caused by human activities. There is also increasing evidence that exogenous environmental drivers, such as climate, induce spatial and temporal synchrony in a wide range of ecological variables. Using Moran's I and Pearson's correlation, we quantified the synchrony of dissolved organic carbon concentration (DOC) and quality (DOM; e.g., specific UV absorbance, Fluorescence Index, PARAFAC), nutrients, discharge and temperature in 40 streams that span an agriculture gradient (0 to >70% cropland), over 10 years. We then used breakpoint regression, 2D-Kolmogorov-Smirnov test and significant zero crossings (SiZer) analyses to quantify the prevalence of nonlinearity and ecological thresholds (breakpoints) where applicable. There was a high degree of synchrony in DOM quality (r > 0.7) but not DOC (r < 0.4). The degree of synchrony was driven in part by the catchment's land use. With respect to the nonlinear analyses we found non-linearity in ~50% of bivariate datasets analyzed. Non-linearity was also driven in part by the catchment's land use. Breakpoints defined different DOM properties. Nonlinearity and synchronous behaviour in DOM are intimately linked to land use.

Faecal nitrogen excretion as an approach to estimate forage intake of wethers.

PubMed

Kozloski, G V; Oliveira, L; Poli, C H E C; Azevedo, E B; David, D B; Ribeiro Filho, H M N; Collet, S G

2014-08-01

Data from twenty-two digestibility trials were compiled to examine the relationship between faecal N concentration and organic matter (OM) digestibility (OMD), and between faecal N excretion and OM intake (OMI) by wethers fed tropical or temperate forages alone or with supplements. Data set was grouped by diet type as follows: only tropical grass (n = 204), only temperate grass (n = 160), tropical grass plus supplement (n = 216), temperate grass plus supplement (n = 48), tropical grass plus tropical legume (n = 60) and temperate grass with ruminal infusion of tannins (n = 16). Positive correlation between OMD and either total faecal N concentration (Nfc, % of OM) or metabolic faecal N concentration (Nmetfc, % of OM) was significant for most diet types. Exceptions were the diet that included a tropical legume, where both relationships were negative, and the diet that included tannin extract, where the correlation between OMD and Nfc was not significant. Pearson correlation and linear regressions between OM intake (OMI, g/day) and faecal N excretion (Nf, g/day) were significant for all diet types. When OMI was estimated from the OM faecal excretion and Nfc-based OMD values, the linear comparison between observed and estimated OMI values showed intercept different from 0 and slope different from 1. When OMI was estimated using the Nf-based linear regressions, the linear comparison between observed and estimated OMI values showed neither intercept different from 0 nor slope different from 1. Both linear comparisons showed similar R(2) values (i.e. 0.78 vs. 0.79). In conclusion, linear equations are suitable for directly estimating OM intake by wethers, fed only forage or forage plus supplements, from the amount of N excreted in faeces. The use of this approach in experiments with grazing wethers has the advantage of accounting for individual variations in diet selection and digestion processes and precludes the use of techniques to estimate forage digestibility. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Relationship between Gender Roles and Sexual Assertiveness in Married Women.

PubMed

Azmoude, Elham; Firoozi, Mahbobe; Sadeghi Sahebzad, Elahe; Asgharipour, Neghar

2016-10-01

Evidence indicates that sexual assertiveness is one of the important factors affecting sexual satisfaction. According to some studies, traditional gender norms conflict with women's capability in expressing sexual desires. This study examined the relationship between gender roles and sexual assertiveness in married women in Mashhad, Iran. This cross-sectional study was conducted on 120 women who referred to Mashhad health centers through convenient sampling in 2014-15. Data were collected using Bem Sex Role Inventory (BSRI) and Hulbert index of sexual assertiveness. Data were analyzed using SPSS 16 by Pearson and Spearman's correlation tests and linear Regression Analysis. The mean scores of sexual assertiveness was 54.93±13.20. According to the findings, there was non-significant correlation between Femininity and masculinity score with sexual assertiveness (P=0.069 and P=0.080 respectively). Linear regression analysis indicated that among the predictor variables, only Sexual function satisfaction was identified as the sexual assertiveness summary predictor variables (P=0.001). Based on the results, sexual assertiveness in married women does not comply with gender role, but it is related to Sexual function satisfaction. So, counseling psychologists need to consider this variable when designing intervention programs for modifying sexual assertiveness and find other variables that affect sexual assertiveness.

Relationship between Gender Roles and Sexual Assertiveness in Married Women

PubMed Central

Azmoude, Elham; Firoozi, Mahbobe; Sadeghi Sahebzad, Elahe; Asgharipour, Neghar

2016-01-01

ABSTRACT Background: Evidence indicates that sexual assertiveness is one of the important factors affecting sexual satisfaction. According to some studies, traditional gender norms conflict with women’s capability in expressing sexual desires. This study examined the relationship between gender roles and sexual assertiveness in married women in Mashhad, Iran. Methods: This cross-sectional study was conducted on 120 women who referred to Mashhad health centers through convenient sampling in 2014-15. Data were collected using Bem Sex Role Inventory (BSRI) and Hulbert index of sexual assertiveness. Data were analyzed using SPSS 16 by Pearson and Spearman’s correlation tests and linear Regression Analysis. Results: The mean scores of sexual assertiveness was 54.93±13.20. According to the findings, there was non-significant correlation between Femininity and masculinity score with sexual assertiveness (P=0.069 and P=0.080 respectively). Linear regression analysis indicated that among the predictor variables, only Sexual function satisfaction was identified as the sexual assertiveness summary predictor variables (P=0.001). Conclusion: Based on the results, sexual assertiveness in married women does not comply with gender role, but it is related to Sexual function satisfaction. So, counseling psychologists need to consider this variable when designing intervention programs for modifying sexual assertiveness and find other variables that affect sexual assertiveness. PMID:27713899

Prediction of anthropometric measurements from tooth length--A Dravidian study.

PubMed

Sunitha, J; Ananthalakshmi, R; Sathiya, Jeeva J; Nadeem, Jeddy; Dhanarathnam, Shanmugam

2015-12-01

Anthropometric measurement is essential for identification of both victims and suspects. Often, this data is not readily available in a crime scene situation. The availability of one data set should help in predicting the other. This study was hypothesised on the basis of a correlation and geometry between the tooth length and various body measurements. To correlate face, palm, foot and stature measurements with tooth length. To derive a regression formula to estimate the various measurements from tooth length. The present study was conducted on Dravidian dental students in the age group 18 - 25 with a sample size of 372. All of the dental and physical parameters were measured using standard anthropometric equipments and techniques. The data was analysed using SPSS software and the methods used for statistical analysis were linear regression analysis and Pearson correlation. The parameters (incisor height (IH), face height (FH), palm length (PL), foot length (FL) and stature (S) showed nil to mild correlation (R = 0.2 ≤ 0.4) except for palm length (PL) and foot length (FL). (R>0.6). It is concluded that odontometric data is not a reliable source for estimating the face height (FH), palm length (PL), foot length (FL) and stature (S).

Correlation of spleen metabolism assessed by 18F-FDG PET with serum interleukin-2 receptor levels and other biomarkers in patients with untreated sarcoidosis.

PubMed

Kalkanis, Alexandros; Kalkanis, Dimitrios; Drougas, Dimitrios; Vavougios, George D; Datseris, Ioannis; Judson, Marc A; Georgiou, Evangelos

2016-03-01

The objective of our study was to assess the possible relationship between splenic F-18-fluorodeoxyglucose (18F-FDG) uptake and other established biochemical markers of sarcoidosis activity. Thirty treatment-naive sarcoidosis patients were prospectively enrolled in this study. They underwent biochemical laboratory tests, including serum interleukin-2 receptor (sIL-2R), serum C-reactive protein, serum angiotensin-I converting enzyme, and 24-h urine calcium levels, and a whole-body combined 18F-FDG PET/computed tomography (PET/CT) scan as a part of an ongoing study at our institute. These biomarkers were statistically compared in these patients. A statistically significant linear dependence was detected between sIL-2R and log-transformed spleen-average standard uptake value (SUV avg) (R2=0.488, P<0.0001) and log-transformed spleen-maximum standard uptake value (SUV max) (R2=0.490, P<0.0001). sIL-2R levels and splenic size correlated linearly (Pearson's r=0.373, P=0.042). Multivariate linear regression analysis revealed that this correlation remained significant after age and sex adjustment (β=0.001, SE=0.001, P=0.024). No statistically significant associations were detected between (a) any two serum biomarkers or (b) between spleen-SUV measurements and any serum biomarker other than sIL-2R. Our analysis revealed an association between sIL-2R levels and spleen 18F-FDG uptake and size, whereas all other serum biomarkers were not significantly associated with each other or with PET 18F-FDG uptake. Our results suggest that splenic inflammation may be related to the systemic inflammatory response in sarcoidosis that may be associated with elevated sIL-2R levels.

Stature Estimation from Lower Limb Anthropometry using Linear Regression Analysis: A Study on the Malaysian Population.

PubMed

Abu Bakar, S N; Aspalilah, A; AbdelNasser, I; Nurliza, A; Hairuliza, M J; Swarhib, M; Das, S; Mohd Nor, F

2017-01-01

Stature is one of the characteristics that could be used to identify human, besides age, sex and racial affiliation. This is useful when the body found is either dismembered, mutilated or even decomposed, and helps in narrowing down the missing person's identity. The main aim of the present study was to construct regression functions for stature estimation by using lower limb bones in the Malaysian population. The sample comprised 87 adult individuals (81 males, 6 females) aged between 20 to 79 years. The parameters such as thigh length, lower leg length, leg length, foot length, foot height and foot breadth were measured. They were measured by a ruler and measuring tape. Statistical analysis involved independent t-test to analyse the difference between lower limbs in male and female. The Pearson's correlation test was used to analyse correlations between lower limb parameters and stature, and the linear regressions were used to form equations. The paired t-test was used to compare between actual stature and estimated stature by using the equations formed. Using independent t-test, there was a significant difference (p< 0.05) in the measurement between males and females with regard to leg length, thigh length, lower leg length, foot length and foot breadth. The thigh length, leg length and foot length were observed to have strong correlations with stature with p= 0.75, p= 0.81 and p= 0.69, respectively. Linear regressions were formulated for stature estimation. Paired t-test showed no significant difference between actual stature and estimated stature. It is concluded that regression functions can be used to estimate stature to identify skeletal remains in the Malaysia population.

The Relationship of Spirituality Development and Addiction Potential Among Students of Qom University of Medical Sciences.

PubMed

Aliakbarzadeh Arani, Zahra; Biderafsh, Azam; Salmani, Somaie

2018-06-01

Drug abuse is one of the problems of the world which due to the specific characteristics of individual, social and personality causes irreparable difficult. The aim of this study was the investigation of the relationship between the spirituality development and addiction potential among students of Qom University of Medical Sciences, Iran. This cross-sectional study was performed in Qom University of Medical Sciences, Iran, from February 2015 to July 2016 which accommodates 250 subjects that were selected through systematic random sampling. Data collection tools were demographic, spiritual attitude and addiction potential questionnaire. Data were analyzed, using frequency, percent, Pearson correlation and linear regression analysis in SPSS 20 software. The mean age was 22.26 ± 4.8; 189 (75.6%) of them were women, 207 (82.8%) were single, 239 (95.6%) of them were Iranian, and the others were non-Iranian. The Pearson correlation coefficient between spiritual attitude and addiction potential (R = - 0.25) at the level of p < 0.001 and between spiritual ability and addiction (R = - 0.16) at the level of p < 0/009 was reversed and meaningful, and between spiritual attitude and spiritual ability (R = 0/76) is directly and statistically significant at the level of p < 0/001. Increasing spiritual attitude and spiritual ability is associated with decreasing addiction potential among students. Information this article can be use to planning spirituality development among students that can be a kind of obstacle against addiction during stressful events.

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.

Accurate assessment of breast volume: a study comparing the volumetric gold standard (direct water displacement measurement of mastectomy specimen) with a 3D laser scanning technique.

PubMed

Yip, Jia Miin; Mouratova, Naila; Jeffery, Rebecca M; Veitch, Daisy E; Woodman, Richard J; Dean, Nicola R

2012-02-01

Preoperative assessment of breast volume could contribute significantly to the planning of breast-related procedures. The availability of 3D scanning technology provides us with an innovative method for doing this. We performed this study to compare measurements by this technology with breast volume measurement by water displacement. A total of 30 patients undergoing 39 mastectomies were recruited from our center. The volume of each patient's breast(s) was determined with a preoperative 3D laser scan. The volume of the mastectomy specimen was then measured in the operating theater by water displacement. There was a strong linear association between breast volumes measured using the 2 different methods when using a Pearson correlation (r = 0.95, P < 0.001). The mastectomy mean volume was defined by the equation: mastectomy mean volume = (scan mean volume × 1.03) -70.6. This close correlation validates the Cyberware WBX Scanner as a tool for assessment of breast volume.

Attitudes Toward Nursing Students With Disabilities: Promoting Social Inclusion.

PubMed

Shpigelman, Carmit-Noa; Zlotnick, Cheryl; Brand, Rachel

2016-08-01

Nursing education programs rarely refer to individuals with disabilities as potential nursing students; more often, the assumption is that they are patients. Thus, this study aimed to capture nursing students' perspectives of social inclusion through examination of their attitudes toward nursing student colleagues with disabilities. Paper-and-pencil structured surveys containing two validated scales were collected from Israeli nursing students (N = 270). Analyses included measuring associations using Pearson's correlation coefficient and general linear regression models. Nursing students held relatively negative attitudes toward colleagues with disabilities, and these negative attitudes were correlated to attitudes toward people with disabilities in general, even after adjusting for noted confounders. Nurse educators and nursing students should be aware of prejudicial attitudes with their respective communities toward nursing student colleagues with disabilities, and they should work toward a better understanding that cultural competence and awareness extends not only to patients but also to one's colleagues. [J Nurs Educ. 2016;55(8):441-449.]. Copyright 2016, SLACK Incorporated.

Ex-vivo UV autofluorescence imaging and fluorescence spectroscopy of atherosclerotic pathology in human aorta

NASA Astrophysics Data System (ADS)

Lewis, William; Williams, Maura; Franco, Walfre

2017-02-01

The aim of our study was to identify fluorescence excitation-emission pairs correlated with atherosclerotic pathology in ex-vivo human aorta. Wide-field images of atherosclerotic human aorta were captured using UV and visible excitation and emission wavelength pairs of several known fluorophores to investigate correspondence with gross pathologic features. Fluorescence spectroscopy and histology were performed on 21 aortic samples. A matrix of Pearson correlation coefficients were determined for the relationship between relevant histologic features and the intensity of emission for 427 wavelength pairs. A multiple linear regression analysis indicated that elastin (370/460 nm) and tryptophan (290/340 nm) fluorescence predicted 58% of the variance in intima thickness (R-squared = 0.588, F(2,18) = 12.8, p=.0003), and 48% of the variance in media thickness (R-squared = 0.483, F(2,18) = 8.42, p=.002), suggesting that endogenous fluorescence intensity at these wavelengths can be utilized for improved pathologic characterization of atherosclerotic plaques.

REGRES: A FORTRAN-77 program to calculate nonparametric and ``structural'' parametric solutions to bivariate regression equations

NASA Astrophysics Data System (ADS)

Rock, N. M. S.; Duffy, T. R.

REGRES allows a range of regression equations to be calculated for paired sets of data values in which both variables are subject to error (i.e. neither is the "independent" variable). Nonparametric regressions, based on medians of all possible pairwise slopes and intercepts, are treated in detail. Estimated slopes and intercepts are output, along with confidence limits, Spearman and Kendall rank correlation coefficients. Outliers can be rejected with user-determined stringency. Parametric regressions can be calculated for any value of λ (the ratio of the variances of the random errors for y and x)—including: (1) major axis ( λ = 1); (2) reduced major axis ( λ = variance of y/variance of x); (3) Y on Xλ = infinity; or (4) X on Y ( λ = 0) solutions. Pearson linear correlation coefficients also are output. REGRES provides an alternative to conventional isochron assessment techniques where bivariate normal errors cannot be assumed, or weighting methods are inappropriate.

Estimating the total energy demand for supra-maximal exercise using the VO2-power regression from an incremental exercise test.

PubMed

Aisbett, B; Le Rossignol, P

2003-09-01

The VO2-power regression and estimated total energy demand for a 6-minute supra-maximal exercise test was predicted from a continuous incremental exercise test. Sub-maximal VO2-power co-ordinates were established from the last 40 seconds (s) of 150-second exercise stages. The precision of the estimated total energy demand was determined using the 95% confidence interval (95% CI) of the estimated total energy demand. The linearity of the individual VO2-power regression equations was determined using Pearson's correlation coefficient. The mean 95% CI of the estimated total energy demand was 5.9 +/- 2.5 mL O2 Eq x kg(-1) x min(-1), and the mean correlation coefficient was 0.9942 +/- 0.0042. The current study contends that the sub-maximal VO2-power co-ordinates from a continuous incremental exercise test can be used to estimate supra-maximal energy demand without compromising the precision of the accumulated oxygen deficit (AOD) method.

Protein model quality assessment prediction by combining fragment comparisons and a consensus Cα contact potential

PubMed Central

Zhou, Hongyi; Skolnick, Jeffrey

2009-01-01

In this work, we develop a fully automated method for the quality assessment prediction of protein structural models generated by structure prediction approaches such as fold recognition servers, or ab initio methods. The approach is based on fragment comparisons and a consensus Cα contact potential derived from the set of models to be assessed and was tested on CASP7 server models. The average Pearson linear correlation coefficient between predicted quality and model GDT-score per target is 0.83 for the 98 targets which is better than those of other quality assessment methods that participated in CASP7. Our method also outperforms the other methods by about 3% as assessed by the total GDT-score of the selected top models. PMID:18004783

A non-linear regression method for CT brain perfusion analysis

NASA Astrophysics Data System (ADS)

Bennink, E.; Oosterbroek, J.; Viergever, M. A.; Velthuis, B. K.; de Jong, H. W. A. M.

2015-03-01

CT perfusion (CTP) imaging allows for rapid diagnosis of ischemic stroke. Generation of perfusion maps from CTP data usually involves deconvolution algorithms providing estimates for the impulse response function in the tissue. We propose the use of a fast non-linear regression (NLR) method that we postulate has similar performance to the current academic state-of-art method (bSVD), but that has some important advantages, including the estimation of vascular permeability, improved robustness to tracer-delay, and very few tuning parameters, that are all important in stroke assessment. The aim of this study is to evaluate the fast NLR method against bSVD and a commercial clinical state-of-art method. The three methods were tested against a published digital perfusion phantom earlier used to illustrate the superiority of bSVD. In addition, the NLR and clinical methods were also tested against bSVD on 20 clinical scans. Pearson correlation coefficients were calculated for each of the tested methods. All three methods showed high correlation coefficients (>0.9) with the ground truth in the phantom. With respect to the clinical scans, the NLR perfusion maps showed higher correlation with bSVD than the perfusion maps from the clinical method. Furthermore, the perfusion maps showed that the fast NLR estimates are robust to tracer-delay. In conclusion, the proposed fast NLR method provides a simple and flexible way of estimating perfusion parameters from CT perfusion scans, with high correlation coefficients. This suggests that it could be a better alternative to the current clinical and academic state-of-art methods.

Stability of physical activity, fitness components and diet quality indices.

PubMed

Mertens, E; Clarys, P; Mullie, P; Lefevre, J; Charlier, R; Knaeps, S; Huybrechts, I; Deforche, B

2017-04-01

Regular physical activity (PA), a high level of fitness and a high diet quality are positively associated with health. However, information about stability of fitness components and diet quality indices is limited. This study aimed to evaluate stability of those parameters. This study includes 652 adults (men=57.56 (10.28) years; women=55.90 (8.34) years at follow-up) who participated in 2002-2004 and returned for follow-up at the Policy Research Centre Leuven in 2012-2014. Minutes sport per day and Physical activity level (PAL) were calculated from the Flemish Physical Activity Computerized Questionnaire. Cardiorespiratory fitness (CRF), morphological fitness (MORF; body mass index and waist circumference) and metabolic fitness (METF) (blood cholesterol and triglycerides) were used as fitness components. Diet quality indices (Healthy Eating Index-2010 (HEI), Diet Quality Index (DQI), Mediterranean Diet Score (MDS)) were calculated from a diet record. Tracking coefficients were calculated using Pearson/Spearman correlation coefficients (r Pearson ) and intra-class correlation coefficients (r ICC ). In both men (r Pearson&ICC =0.51) and women (r Pearson =0.62 and r ICC =0.60) PAL showed good stability, while minutes sport remained stable in women (r Pearson&ICC =0.57) but less in men (r Pearson&ICC =0.45). Most fitness components remained stable (r⩾0.50) except some METF components in women. In general the diet quality indices and their components were unstable (r<0.50). PAL and the majority of the fitness components remained stable, while diet quality was unstable over 10 years. For unstable parameters such as diet quality measurements are needed at both time points in prospective research.

[Quantitative analysis of drug expenditures variability in dermatology units].

PubMed

Moreno-Ramírez, David; Ferrándiz, Lara; Ramírez-Soto, Gabriel; Muñoyerro, M Dolores

2013-01-01

Variability in adjusted drug expenditures among clinical departments raises the possibility of difficult access to certain therapies at the time that avoidable expenditures may also exist. Nevertheless, drug expenditures are not usually applied to clinical practice variability analysis. To identify and quantify variability in drug expenditures in comparable dermatology department of the Servicio Andaluz de Salud. Comparative economic analysis regarding the drug expenditures adjusted to population and health care production in 18 dermatology departments of the Servicio Andaluz de Salud. The 2012 cost and production data (homogeneous production units -HPU-)were provided by Inforcoan, the cost accounting information system of the Servicio Andaluz de Salud. The observed drug expenditure ratio ranged from 0.97?/inh to 8.90?/inh and from 208.45?/HPU to 1,471.95?/ HPU. The Pearson correlation between drug expenditure and population was 0.25 and 0.35 for the correlation between expenditure and homogeneous production (p=0.32 and p=0,15, respectively), both Pearson coefficients confirming the lack of correlation and arelevant degree of variability in drug expenditures. The quantitative analysis of variability performed through Pearson correlation has confirmed the existence of drug expenditure variability among comparable dermatology departments. Copyright © 2013 SEFH. Published by AULA MEDICA. All rights reserved.

IROA: International Register of Open Abdomen, preliminary results.

PubMed

Coccolini, Federico; Montori, Giulia; Ceresoli, Marco; Catena, Fausto; Ivatury, Rao; Sugrue, Michael; Sartelli, Massimo; Fugazzola, Paola; Corbella, Davide; Salvetti, Francesco; Negoi, Ionut; Zese, Monica; Occhionorelli, Savino; Maccatrozzo, Stefano; Shlyapnikov, Sergei; Galatioto, Christian; Chiarugi, Massimo; Demetrashvili, Zaza; Dondossola, Daniele; Yovtchev, Yovcho; Ioannidis, Orestis; Novelli, Giuseppe; Nacoti, Mirco; Khor, Desmond; Inaba, Kenji; Demetriades, Demetrios; Kaussen, Torsten; Jusoh, Asri Che; Ghannam, Wagih; Sakakushev, Boris; Guetta, Ohad; Dogjani, Agron; Costa, Stefano; Singh, Sandeep; Damaskos, Dimitrios; Isik, Arda; Yuan, Kuo-Ching; Trotta, Francesco; Rausei, Stefano; Martinez-Perez, Aleix; Bellanova, Giovanni; Fonseca, Vinicius Cordeiro; Hernández, Fernando; Marinis, Athanasios; Fernandes, Wellington; Quiodettis, Martha; Bala, Miklosh; Vereczkei, Andras; Curado, Rafael L; Fraga, Gustavo Pereira; Pereira, Bruno M; Gachabayov, Mahir; Chagerben, Guillermo Perez; Arellano, Miguel Leon; Ozyazici, Sefa; Costa, Gianluca; Tezcaner, Tugan; Ansaloni, Luca

2017-01-01

No definitive data about open abdomen (OA) epidemiology and outcomes exist. The World Society of Emergency Surgery (WSES) and the Panamerican Trauma Society (PTS) promoted the International Register of Open Abdomen (IROA). A prospective observational cohort study including patients with an OA treatment. Data were recorded on a web platform (Clinical Registers®) through a dedicated website: www.clinicalregisters.org. Four hundred two patients enrolled. Adult patients: 369 patients; Mean age: 57.39±18.37; 56% male; Mean BMI: 36±5.6. OA indication: Peritonitis (48.7%), Trauma (20.5%), Vascular Emergencies/Hemorrhage (9.4%), Ischemia (9.1%), Pancreatitis (4.2%),Post-operative abdominal-compartment-syndrome (3.9%), Others (4.2%). The most adopted Temporary-abdominal-closure systems were the commercial negative pressure ones (44.2%). During OA 38% of patients had complications; among them 10.5% had fistula. Definitive closure: 82.8%; Mortality during treatment: 17.2%. Mean duration of OA: 5.39(±4.83) days; Mean number of dressing changes: 0.88(±0.88). After-closure complications: (49.5%) and Mortality: (9%). No significant associations among TACT, indications, mortality, complications and fistula. A linear correlationexists between days of OA and complications (Pearson linear correlation = 0.326 p <0.0001) and with the fistula development (Pearson = 0.146 p = 0.016). Pediatric patients: 33 patients. Mean age: 5.91±(3.68) years; 60% male. Mortality: 3.4%; Complications: 44.8%; Fistula: 3.4%. Mean duration of OA: 3.22(±3.09) days. Temporary abdominal closure is reliable and safe. The different techniques account for different results according to the different indications. In peritonitis commercial negative pressure temporary closure seems to improve results. In trauma skin-closure and Bogotà-bag seem to improve results. ClinicalTrials.gov NCT02382770.

CORRELATION BETWEEN METAL-CERAMIC BOND STRENGTH AND COEFFICIENT OF LINEAR THERMAL EXPANSION DIFFERENCE

PubMed Central

Lopes, Stella Crosara; Pagnano, Valéria Oliveira; Rollo, João Manuel Domingos de Almeida; Leal, Mônica Barbosa; Bezzon, Osvaldo Luiz

2009-01-01

The purpose of this study was to evaluate the metal-ceramic bond strength (MCBS) of 6 metal-ceramic pairs (2 Ni-Cr alloys and 1 Pd-Ag alloy with 2 dental ceramics) and correlate the MCBS values with the differences between the coefficients of linear thermal expansion (CTEs) of the metals and ceramics. Verabond (VB) Ni-Cr-Be alloy, Verabond II (VB2), Ni-Cr alloy, Pors-on 4 (P), Pd-Ag alloy, and IPS (I) and Duceram (D) ceramics were used for the MCBS test and dilatometric test. Forty-eight ceramic rings were built around metallic rods (3.0 mm in diameter and 70.0 mm in length) made from the evaluated alloys. The rods were subsequently embedded in gypsum cast in order to perform a tensile load test, which enabled calculating the CMBS. Five specimens (2.0 mm in diameter and 12.0 mm in length) of each material were made for the dilatometric test. The chromel-alumel thermocouple required for the test was welded into the metal test specimens and inserted into the ceramics. ANOVA and Tukey's test revealed significant differences (p=0.01) for the MCBS test results (MPa), with PI showing higher MCBS (67.72) than the other pairs, which did not present any significant differences. The CTE (10-6 °C-1) differences were: VBI (0.54), VBD (1.33), VB2I (-0.14), VB2D (0.63), PI (1.84) and PD (2.62). Pearson's correlation test (r=0.17) was performed to evaluate of correlation between MCBS and CTE differences. Within the limitations of this study and based on the obtained results, there was no correlation between MCBS and CTE differences for the evaluated metal-ceramic pairs. PMID:19274398

Early pregnancy fasting plasma glucose and lipid concentrations in pregnancy and association to offspring size: a retrospective cohort study.

PubMed

Liu, Bin; Geng, Huizhen; Yang, Juan; Zhang, Ying; Deng, Langhui; Chen, Weiqing; Wang, Zilian

2016-03-17

Hyperlipidemia and high fasting plasma glucose levels at the first prenatal visit (First Visit FPG) are both related to gestational diabetes mellitus, maternal obesity/overweight and fetal overgrowth. The purpose of the present study is to investigate the correlation between First Visit FPG and lipid concentrations, and their potential association with offspring size at delivery. Pregnant women that received regular prenatal care and delivered in our center in 2013 were recruited for the study. Fasting plasma glucose levels were tested at the first prenatal visit (First Visit FPG) and prior to delivery (Before Delivery FPG). HbA1c and lipid profiles were examined at the time of OGTT test. Maternal and neonatal clinical data were collected for analysis. Data was analyzed by independent sample t test, Pearson correlation, and Chi-square test, followed by partial correlation and multiple linear regression analyses to confirm association. Statistical significance level was α =0.05. Analyses were based on 1546 mother-baby pairs. First Visit FPG was not correlated with any lipid parameters after adjusting for maternal pregravid BMI, maternal age and gestational age at First Visit FPG. HbA1c was positively correlated with triglyceride and Apolipoprotein B in the whole cohort and in the NGT group after adjusting for maternal age and maternal BMI at OGTT test. Multiple linear regression analyses showed neonatal birth weight, head circumference and shoulder circumference were all associated with First Visit FPG and triglyceride levels. Fasting plasma glucose at first prenatal visit is not associated with lipid concentrations in mid-pregnancy, but may influence fetal growth together with triglyceride concentration.

Dietary intakes assessed by 24-h recalls in peri-urban African adolescents: validity of energy intake compared with estimated energy expenditure.

PubMed

Rankin, D; Ellis, S M; Macintyre, U E; Hanekom, S M; Wright, H H

2011-08-01

The objective of this study is to determine the relative validity of reported energy intake (EI) derived from multiple 24-h recalls against estimated energy expenditure (EE(est)). Basal metabolic rate (BMR) equations and physical activity factors were incorporated to calculate EE(est). This analysis was nested in the multidisciplinary PhysicaL Activity in the Young study with a prospective study design. Peri-urban black South African adolescents were investigated in a subsample of 131 learners (87 girls and 44 boys) from the parent study sample of 369 (211 girls and 158 boys) who had all measurements taken. Pearson correlation coefficients and Bland-Altman plots were calculated to identify the most accurate published equations to estimate BMR (P<0.05 statistically significant). EE(est) was estimated using BMR equations and estimated physical activity factors derived from Previous Day Physical Activity Recall questionnaires. After calculation of EE(est), the relative validity of reported energy intake (EI(rep)) derived from multiple 24-h recalls was tested for three data subsets using Pearson correlation coefficients. Goldberg's formula identified cut points (CPs) for under and over reporting of EI. Pearson correlation coefficients between calculated BMRs ranged from 0.97 to 0.99. Bland-Altman analyses showed acceptable agreement (two equations for each gender). One equation for each gender was used to calculate EE(est). Pearson correlation coefficients between EI(rep) and EE(est) for three data sets were weak, indicating poor agreement. CPs for physical activity groups showed under reporting in 87% boys and 95% girls. The 24-h recalls measured at five measurements over 2 years offered poor validity between EI(rep) and EE(est).

Relationship between left atrium catheter contact force and pacing threshold.

PubMed

Barrio-López, Teresa; Ortiz, Mercedes; Castellanos, Eduardo; Lázaro, Carla; Salas, Jefferson; Madero, Sergio; Almendral, Jesús

2017-08-01

The purpose of this study is to analyze the relationship between contact force (CF) and pacing threshold in left atrium (LA). Six to ten LA sites were studied in 28 consecutive patients with atrial fibrillation undergoing pulmonary vein isolation. Median CF, bipolar and unipolar electrogram voltage, impedance, and bipolar and unipolar thresholds for consistent constant capture and for consistent intermittent capture were measured at each site. Pacing threshold measurements were performed at 188 LA sites. Both unipolar and bipolar pacing thresholds correlated significantly with median CF; however, unipolar pacing threshold correlated better (unipolar: Pearson R -0.45; p < 0.001; Spearman Rho -0.62; p < 0.001, bipolar: Pearson R -0.39; p < 0.001; Spearman Rho -0.52; p < 0.001). Consistent constant capture threshold had better correlation with median CF than consistent intermittent capture threshold for both unipolar and bipolar pacing (Pearson R -0.45; p < 0.001 and Spearman Rho -0.62; p < 0.001 vs. Pearson R -0.35; p < 0.001; Spearman Rho -0.52; p < 0.001). The best pacing threshold cutoff point to detect a good CF (>10 g) was 3.25 mA for unipolar pacing with 69% specificity and 73% sensitivity. Both increased to 80% specificity and 74% sensitivity for sites with normal bipolar voltage and a pacing threshold cutoff value of 2.85 mA. Pacing thresholds correlate with CF in human not previously ablated LA. Since the combination of a normal bipolar voltage and a unipolar pacing threshold <2.85 mA provide reasonable parameters of validity, pacing threshold could be of interest as a surrogate for CF in LA.

Local Volume Hi Survey: the far-infrared radio correlation

NASA Astrophysics Data System (ADS)

Shao, Li; Koribalski, Bärbel S.; Wang, Jing; Ho, Luis C.; Staveley-Smith, Lister

2018-06-01

In this paper we measure the far-infrared (FIR) and radio flux densities of a sample of 82 local gas-rich galaxies, including 70 "dwarf" galaxies (M* < 109 M⊙), from the Local Volume HI Survey (LVHIS), which is close to volume limited. It is found that LVHIS galaxies hold a tight linear FIR-radio correlation (FRC) over four orders of magnitude (F_1.4GHz ∝ F_FIR^{1.00± 0.08}). However, for detected galaxies only, a trend of larger FIR-to-radio ratio with decreasing flux density is observed. We estimate the star formation rate by combining UV and mid-IR data using empirical calibration. It is confirmed that both FIR and radio emission are strongly connected with star formation but with significant non-linearity. Dwarf galaxies are found radiation deficient in both bands, when normalized by star formation rate. It urges a "conspiracy" to keep the FIR-to-radio ratio generally constant. By using partial correlation coefficient in Pearson definition, we identify the key galaxy properties associated with the FIR and radio deficiency. Some major factors, such as stellar mass surface density, will cancel out when taking the ratio between FIR and radio fluxes. The remaining factors, such as HI-to-stellar mass ratio and galaxy size, are expected to cancel each other due to the distribution of galaxies in the parameter space. Such cancellation is probably responsible for the "conspiracy" to keep the FRC alive.

An Investigation of Age-Related Iron Deposition Using Susceptibility Weighted Imaging

PubMed Central

Wang, Dan; Li, Wen-Bin; Wei, Xiao-Er; Li, Yue-Hua; Dai, Yong-Ming

2012-01-01

Aim To quantify age-dependent iron deposition changes in healthy subjects using Susceptibility Weighted Imaging (SWI). Materials and Methods In total, 143 healthy volunteers were enrolled. All underwent conventional MR and SWI sequences. Subjects were divided into eight groups according to age. Using phase images to quantify iron deposition in the head of the caudate nucleus and the lenticular nucleus, the angle radian value was calculated and compared between groups. ANOVA/Pearson correlation coefficient linear regression analysis and polynomial fitting were performed to analyze the relationship between iron deposition in the head of the caudate nucleus and lenticular nucleus with age. Results Iron deposition in the lenticular nucleus increased in individuals aged up to 40 years, but did not change in those aged over 40 years once a peak had been reached. In the head of the caudate nucleus, iron deposition peaked at 60 years (p<0.05). The correlation coefficients for iron deposition in the L-head of the caudate nucleus, R-head of the caudate nucleus, L-lenticular nucleus and R-lenticular nucleus with age were 0.67691, 0.48585, 0.5228 and 0.5228 (p<0.001, respectively). Linear regression analyses showed a significant correlation between iron deposition levels in with age groups. Conclusions Iron deposition in the lenticular nucleus was found to increase with age, reaching a plateau at 40 years. Iron deposition in the head of the caudate nucleus also increased with age, reaching a plateau at 60 years. PMID:23226360

Facing haematopoietic stem-cell transplantation: do patients and their physicians agree regarding the prognosis?

PubMed

Grulke, Norbert; Bailer, Harald

2010-10-01

To evaluate the correlation and concordance between patients' and physicians' estimations of prognoses before initiation of the conditioning regimen for allogeneic haematopoietic stem-cell transplantation. A total of 123 patients and their attending physicians were asked to estimate a prognosis on a six-point scale. The patients were also asked to fill out questionnaires addressing their psychological state and coping. The mean prognostic estimations differed by 1.17 points (p<0.001), with the patients being more optimistic than the physicians. With respect to concordance: Pearson correlation r=0.024 (ns); unweighted kappa and kappa with linear weighting are 0.115 and 0.068, respectively. The prognostic estimates of the patients correlated with their psychological state, but not with the objective disease- or treatment-related variables, whereas the physicians' estimates were partially based on such objective factors. A clear significant association between actual survival and the physicians' estimates, but not the patients' estimates, was observed. If agreement regarding the prognosis exists, the relationship between physicians' and patients' estimates is probably non-linear. Assessing one's chances of being cured is a highly emotional task, and psychological processes such as denial or repression most likely play a decisive role. Moreover, collusion between the patient and physician may be inevitable in this situation. Whether it is desirable to gain concordance and who will benefit from such efforts must be discussed and empirically studied. Copyright © 2009 John Wiley & Sons, Ltd.

[Determination of hydroxyproline in liver tissue by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry].

PubMed

Liu, Wei; Qi, Shenglan; Xu, Ying; Xiao, Zhun; Fu, Yadong; Chen, Jiamei; Yang, Tao; Liu, Ping

2017-12-08

A method for the determination of hydroxyproline (Hyp) in liver tissue of mice by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (HILIC-HRMS) was developed. The liver tissue samples of normal mice and liver fibrosis mice induced by carbon tetrachloride were hydrolyzed by concentrated hydrochloric acid. After filtrated and diluted by solution, the diluent was separated on an Hypersil GOLD HILIC column (100 mm×2.1 mm, 3 μm). Water-acetonitrile (28:72, v/v)were used as the mobile phases with isocratic elution. Finally, the target analytes were detected in positive model by HRMS equipped with an electrospray ionization source. The linear range of hydroxyproline was from 0.78 to 100.00 μg/L with the correlation coefficient ( R 2 ) of 0.9983. The limit of quantification was 0.78 μg/L. By detecting the spiked samples, the recoveries were in the range of 97.4%-100.9% with the relative standard deviations (RSDs) between 1.4% and 2.0%. In addition, comparison of the measurement results by this method and the chloramine T method was proceeded. It was found that the linear correlation between the two methods was very good, and the Pearson correlation coefficient was 0.927. And this method had simpler operation procedure and higher accuracy than chloramine T method. This method can be used for the quick determination of hydroxyproline in liver tissue samples.

Selected plantar pressure characteristics associated with the skating performance of national in-line speed skaters.

PubMed

Wu, Wen-Lan; Hsu, Hsiu-Tao; Chu, I-Hua; Tsai, Feng-Hua; Liang, Jing-Min

2017-06-01

In order to help coaches analyse the techniques of professional in-line speed skaters for making the required fine adjustments and corrections in their push-off work, this study analysed the specific plantar pressure characteristics during a 300-m time-trial test. Fourteen elite in-line speed skaters from the national team were recruited in this study. The total completion time of the 300-m time-trial test, duration of each skating phase, and plantar pressure distribution were measured. The correlation between plantar pressure distribution and skating performance was assessed using Pearson correlation analyses. The results showed that the contact time of the total foot and force-time integral (FTI) in the medial forefoot were significantly correlated with the duration of the start phase, and the FTIs in the medial forefoot of the gliding (left) leg and lateral forefoot of the pushing (right) leg were significantly correlated with the duration of the turning phase. The maximum force in the medial heel, medial forefoot, and median forefoot and the FTI in the medial heel and medial forefoot were significantly correlated with the duration of the linear acceleration phase. The results suggest that a correct plantar loading area and push-off strategy can enhance the skating performance.

Morphological adaptation to climate in modern Homo sapiens crania: the importance of basicranial breadth.

PubMed

Nowaczewska, Wioletta; Dabrowski, Paweł; Kuźmiński, Łukasz

2011-09-01

The aim of this study is to investigate whether the variation in breadth of the cranial base among modern human populations that inhabit different regions of the world is linked with climatic adaptation. This work provides an examination of two hypotheses. The first hypothesis is that the correlation between basicranial breadth and ambient temperature is stronger than the correlation between temperature and other neurocranial variables, such as maximum cranial breadth, maximum neurocranial length, and the endocranial volume. The second hypothesis is that the correlation between the breadth of the cranial base and the ambient temperature is significant even when other neurocranial features used in this study (including the size of the neurocranium) are constant. For the sake of this research, the necessary neurocranial variables for fourteen human populations living in diverse environments were obtained from Howells' data (except for endocranial volume which was obtained by means of estimation). The ambient temperature (more precisely, the mean yearly temperature) of the environments inhabited by these populations was used as a major climatic factor. Data were analysed using Pearson correlation coefficients, linear regression and partial correlation analyses. The results supported the two hypotheses, thus suggesting that ambient temperature may contribute to the observed differences in the breadth of the cranial base in the studied modern humans.

Differential correlation of suicide and homicide rates according to geographical areas: A study with population-level data.

PubMed

Fountoulakis, Konstantinos N; Gonda, Xenia

2017-03-01

The current study investigated the relationship of suicide and homicide rates internationally. WHO database mortality data for 82 countries concerning suicide, homicides, and cancer and traffic accidents as controls were used. The analysis included Pearson correlation and multiple linear regression analysis. Worldwide homicidal rates explained 55.42%, 43.86% and 41.7% of male and 22.0%, 22.14% and 13.25% of female suicides for 2000, 2005 and 2010 respectively. In Europe there was a positive correlation between male suicide rates and all homicide rates including homicide rates in both genders, in male victims, and in female victims. In America there is no significant correlation. In Asia there is a significant correlation of male suicidal rates only with homicide rates of female victims. We observed marked and interesting differences in the pattern of association between Europe and the Americas. Overall the current paper suggests that at least in some human populations, suicidality and homicidality share common etiopathogenetic substrates and could be triggered by the same internal or external events or might develop based on common genetic background. Empirically it has been suggested that suicide is related to higher living standards while murder is related to poor quality of life and lower living standards. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

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.

Multicenter study of quantitative computed tomography analysis using a computer-aided three-dimensional system in patients with idiopathic pulmonary fibrosis.

PubMed

Iwasawa, Tae; Kanauchi, Tetsu; Hoshi, Toshiko; Ogura, Takashi; Baba, Tomohisa; Gotoh, Toshiyuki; Oba, Mari S

2016-01-01

To evaluate the feasibility of automated quantitative analysis with a three-dimensional (3D) computer-aided system (i.e., Gaussian histogram normalized correlation, GHNC) of computed tomography (CT) images from different scanners. Each institution's review board approved the research protocol. Informed patient consent was not required. The participants in this multicenter prospective study were 80 patients (65 men, 15 women) with idiopathic pulmonary fibrosis. Their mean age was 70.6 years. Computed tomography (CT) images were obtained by four different scanners set at different exposures. We measured the extent of fibrosis using GHNC, and used Pearson's correlation analysis, Bland-Altman plots, and kappa analysis to directly compare the GHNC results with manual scoring by radiologists. Multiple linear regression analysis was performed to determine the association between the CT data and forced vital capacity (FVC). For each scanner, the extent of fibrosis as determined by GHNC was significantly correlated with the radiologists' score. In multivariate analysis, the extent of fibrosis as determined by GHNC was significantly correlated with FVC (p < 0.001). There was no significant difference between the results obtained using different CT scanners. Gaussian histogram normalized correlation was feasible, irrespective of the type of CT scanner used.

CT-derived indices of canine osteosarcoma-affected antebrachial strength.

PubMed

Garcia, Tanya C; Steffey, Michele A; Zwingenberger, Allison L; Daniel, Leticia; Stover, Susan M

2017-05-01

To improve the prediction of fractures in dogs with bone tumors of the distal radius by identifying computed tomography (CT) indices that correlate with antebrachial bone strength and fracture location. Prospective experimental study. Dogs with antebrachial osteosarcoma (n = 10), and normal cadaver bones (n=9). Antebrachia were imaged with quantitative CT prior to biomechanical testing to failure. CT indices of structural properties were compared to yield force and maximum force using Pearson correlation tests. Straight beam failure (Fs), axial rigidity, curved beam failure (Fc), and craniocaudal bending moment of inertia (MOICrCd) CT indices most highly correlated (0.77 > R > 0.57) with yield and maximum forces when iOSA-affected and control bones were included in the analysis. Considering only OSA-affected bones, Fs, Fc, and axial rigidity correlated highly (0.85 > R > 0.80) with maximum force. In affected bones, the location of minimum axial rigidity and maximum MOICrCd correlated highly (R > 0.85) with the actual fracture location. CT-derived axial rigidity, Fs, and MOICrCd have strong linear relationships with yield and maximum force. These indices should be further evaluated prospectively in OSA-affected dogs that do, and do not, experience pathologic fracture. © 2017 The American College of Veterinary Surgeons.

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 coefficient and the SD-weighted correlation coefficient, and is particularly useful for clustering replicated microarray data. This computational approach should be generally useful for proteomic data or other high-throughput analysis methodology.

Influence of Cobb Angle and ISIS2 Surface Topography Volumetric Asymmetry on Scoliosis Research Society-22 Outcome Scores in Scoliosis.

PubMed

Brewer, Paul; Berryman, Fiona; Baker, De; Pynsent, Paul; Gardner, Adrian

2013-11-01

Retrospective sequential patient series. To establish the relationship between the magnitude of the deformity in scoliosis and patients' perception of their condition, as measured with Scoliosis Research Society-22 scores. A total of 93 untreated patients with adolescent idiopathic scoliosis were included retrospectively. The Cobb angle was measured from a plain radiograph, and volumetric asymmetry was measured by ISIS2 surface topography. The association between Scoliosis Research Society scores for function, pain, self-image, and mental health against Cobb angle and volumetric asymmetry was investigated using the Pearson correlation coefficient. Correlation of both Cobb angle and volumetric asymmetry with function and pain was weak (all < .23); these correlation values were not statistically significant. Correlation of Cobb angle and volumetric asymmetry with self-image, was higher, although still moderate (-.37 for Cobb angle and -.44 for volumetric asymmetry). Both were statistically significant (Cobb angle, p = .0002; volumetric asymmetry; p = .00001). Cobb angle contributed 13.8% to the linear relationship with self-image, whereas volumetric asymmetry contributed 19.3%. For mental health, correlation was statistically significant with Cobb angle (p = .011) and volumetric asymmetry (p = .0005), but the correlation was low to moderate (-.26 and -.35, respectively). Cobb angle contributed 6.9% to the linear relationship with mental health, whereas volumetric asymmetry contributed 12.4%. Volumetric asymmetry correlates better with both mental health and self-image compared with Cobb angle, but the correlation was only moderate. This study suggests that a patient's own perception of self-image and mental health is multifactorial and not completely explained through present objective measurements of the size of the deformity. This helps to explain the difficulties in any objective analysis of a problem with multifactorial perception issues. Further study is required to investigate other physical aspects of the deformity that may have a role in how patients view themselves. Copyright © 2013 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Correlates of early pregnancy serum brain-derived neurotrophic factor in a Peruvian population.

PubMed

Yang, Na; Levey, Elizabeth; Gelaye, Bizu; Zhong, Qiu-Yue; Rondon, Marta B; Sanchez, Sixto E; Williams, Michelle A

2017-12-01

Knowledge about factors that influence serum brain-derived neurotrophic factor (BDNF) concentrations during early pregnancy is lacking. The aim of the study is to examine the correlates of early pregnancy serum BDNF concentrations. A total of 982 women attending prenatal care clinics in Lima, Peru, were recruited in early pregnancy. Pearson's correlation coefficient was calculated to evaluate the relation between BDNF concentrations and continuous covariates. Analysis of variance and generalized linear models were used to compare the unadjusted and adjusted BDNF concentrations according to categorical variables. Multivariable linear regression models were applied to determine the factors that influence early pregnancy serum BDNF concentrations. In bivariate analysis, early pregnancy serum BDNF concentrations were positively associated with maternal age (r = 0.16, P < 0.001) and early pregnancy body mass index (BMI) (r = 0.17, P < 0.001), but inversely correlated with gestational age at sample collection (r = -0.21, P < 0.001) and C-reactive protein (CRP) concentrations (r = -0.07, P < 0.05). In the multivariable linear regression model, maternal age (β = 0.11, P = 0.001), early pregnancy BMI (β = 1.58, P < 0.001), gestational age at blood collection (β = -0.33, P < 0.001), and serum CRP concentrations (β = -0.57, P = 0.002) were significantly associated with early pregnancy serum BDNF concentrations. Participants with moderate antepartum depressive symptoms (Patient Health Questionnaire-9 (PHQ-9) score ≥ 10) had lower serum BDNF concentrations compared with participants with no/mild antepartum depressive symptoms (PHQ-9 score < 10). Maternal age, early pregnancy BMI, gestational age, and the presence of moderate antepartum depressive symptoms were statistically significantly associated with early pregnancy serum BDNF concentrations in low-income Peruvian women. Biological changes of CRP during pregnancy may affect serum BDNF concentrations.

Socio-economic factors associated with infant mortality in Italy: an ecological study

PubMed Central

2012-01-01

Introduction One issue that continues to attract the attention of public health researchers is the possible relationship in high-income countries between income, income inequality and infant mortality (IM). The aim of this study was to assess the associations between IM and major socio-economic determinants in Italy. Methods Associations between infant mortality rates in the 20 Italian regions (2006–2008) and the Gini index of income inequality, mean household income, percentage of women with at least 8 years of education, and percentage of unemployed aged 15–64 years were assessed using Pearson correlation coefficients. Univariate linear regression and multiple stepwise linear regression analyses were performed to determine the magnitude and direction of the effect of the four socio-economic variables on IM. Results The Gini index and the total unemployment rate showed a positive strong correlation with IM (r = 0.70; p < 0.001 and r = 0.84; p < 0.001 respectively), mean household income showed a strong negative correlation (r = −0.78; p < 0.001), while female educational attainment presented a weak negative correlation (r = −0.45; p < 0.05). Using a multiple stepwise linear regression model, only unemployment rate was independently associated with IM (b = 0.15, p < 0.001). Conclusions In Italy, a high-income country where health care is universally available, variations in IM were strongly associated with relative and absolute income and unemployment rate. These results suggest that in Italy IM is not only related to income distribution, as demonstrated for other developed countries, but also to economic factors such as absolute income and unemployment. In order to reduce IM and the existing inequalities, the challenge for Italian decision makers is to promote economic growth and enhance employment levels. PMID:22898293

Saving time and money: a validation of the self ratings on the prospective NIMH Life-Chart Method (NIMH-LCM).

PubMed

Born, Christoph; Amann, Benedikt L; Grunze, Heinz; Post, Robert M; Schärer, Lars

2014-05-07

Careful observation of the longitudinal course of bipolar disorders is pivotal to finding optimal treatments and improving outcome. A useful tool is the daily prospective Life-Chart Method, developed by the National Institute of Mental Health. However, it remains unclear whether the patient version is as valid as the clinician version. We compared the patient-rated version of the Lifechart (LC-self) with the Young-Mania-Rating Scale (YMRS), Inventory of Depressive Symptoms-Clinician version (IDS-C), and Clinical Global Impression-Bipolar version (CGI-BP) in 108 bipolar I and II patients who participated in the Naturalistic Follow-up Study (NFS) of the German centres of the Bipolar Collaborative Network (BCN; formerly Stanley Foundation Bipolar Network). For statistical evaluation, levels of severity of mood states on the Lifechart were transformed numerically and comparison with affective scales was performed using chi-square and t tests. For testing correlations Pearson´s coefficient was calculated. Ratings for depression of LC-self and total scores of IDS-C were found to be highly correlated (Pearson coefficient r = -.718; p < .001), whilst the correlation of ratings for mania with YMRS compared to LC-self were slightly less robust (Pearson coefficient r = .491; p = .001). These results were confirmed by good correlations between the CGI-BP IA (mania), IB (depression) and IC (overall mood state) and the LC-self ratings (Pearson coefficient r = .488, r = .721 and r = .65, respectively; all p < .001). The LC-self shows a significant correlation and good concordance with standard cross sectional affective rating scales, suggesting that the LC-self is a valid and time and money saving alternative to the clinician-rated version which should be incorporated in future clinical research in bipolar disorder. Generalizability of the results is limited by the selection of highly motivated patients in specialized bipolar centres and by the open design of the study.

Linearised and non-linearised isotherm models optimization analysis by error functions and statistical means

PubMed Central

2014-01-01

In adsorption study, to describe sorption process and evaluation of best-fitting isotherm model is a key analysis to investigate the theoretical hypothesis. Hence, numerous statistically analysis have been extensively used to estimate validity of the experimental equilibrium adsorption values with the predicted equilibrium values. Several statistical error analysis were carried out. In the present study, the following statistical analysis were carried out to evaluate the adsorption isotherm model fitness, like the Pearson correlation, the coefficient of determination and the Chi-square test, have been used. The ANOVA test was carried out for evaluating significance of various error functions and also coefficient of dispersion were evaluated for linearised and non-linearised models. The adsorption of phenol onto natural soil (Local name Kalathur soil) was carried out, in batch mode at 30 ± 20 C. For estimating the isotherm parameters, to get a holistic view of the analysis the models were compared between linear and non-linear isotherm models. The result reveled that, among above mentioned error functions and statistical functions were designed to determine the best fitting isotherm. PMID:25018878

Relationship between head posture and dentofacial morphology in patients with TMJ osteoarthritis/osteoarthrosis.

PubMed

Ioi, Hideki; Matsumoto, Ryusuke; Nishioka, Masato; Goto, Tazuko K; Nakata, Shunsuke; Nakasima, Akihiko; Counts, Amy L

2008-01-01

To test whether there is a relationship between head and cervical posture and dentofacial morphology in patients with temporomandibular joint osteoarthritis/osteoarthrosis (OA). The subjects consisted of 34 Japanese females with TMJ OA (aged 24.7 +/- 6.1 years). Six craniocervical angular measurements were constructed for head posture. Two angular and 6 linear measurements were constructed for the skeletal relationship, while 1 angular and 6 linear measurements were constructed for the dental relationship. Pearson correlation coefficients were calculated between head posture and dentofacial variables. In the skeletal relationship, increased craniocervical angulations were significantly associated with a more posterior position of the maxilla, a decreased Frankfort to mandibular plane angle, decreased mandibular length, and a decreased lower facial height. In the dental relationship, increased craniocervical angulations were significantly associated with more posterior positions of the anterior teeth to the basal bone and decreased alveolar height of the anterior-posterior teeth. The hypothesis was rejected. These results suggest that an association may exist between head and cervical posture and dentofacial morphology in patients with TMJ OA.

WE-AB-202-08: Feasibility of Single-Inhalation/Single-Energy Xenon CT for High-Resolution Imaging of Regional Lung Ventilation in Humans

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

Pinkham, D; Schueler, E; Diehn, M

Purpose: To demonstrate the efficacy of a novel functional lung imaging method that utilizes single-inhalation, single-energy xenon CT (Xe-CT) lung ventilation scans, and to compare it against the current clinical standard, ventilation single-photon emission CT (V-SPECT). Methods: In an IRB-approved clinical study, 14 patients undergoing thoracic radiotherapy received two successive single inhalation, single energy (80keV) CT images of the entire lung using 100% oxygen and a 70%/30% xenon-oxygen mixture. A subset of ten patients also received concurrent SPECT ventilation scans. Anatomic reproducibility between the two scans was achieved using a custom video biofeedback apparatus. The CT images were registered tomore » each other by deformable registration, and a calculated difference image served as surrogate xenon ventilation map. Both lungs were partitioned into twelve sectors, and a sector-wise correlation was performed between the xenon and V-SPECT scans. A linear regression model was developed with forced expiratory volume (FEV) as a predictor and the coefficient of variation (CoV) as the outcome. Results: The ventilation comparison for five of the patients had either moderate to strong Pearson correlation coefficients (0.47 to 0.69, p<0.05). Of these, four also had moderate to strong Spearman correlation coefficients (0.46 to 0.80, p<0.03). The patients with the strongest correlation had clear regional ventilation deficits. The patient comparisons with the weakest correlations had more homogeneous ventilation distributions, and those patients also had diminished lung function as assessed by spirometry. Analysis of the relationship between CoV and FEV yielded a non-significant trend toward negative correlation (Pearson coefficient −0.60, p<0.15). Conclusion: Significant correlations were found between the Xe-CT and V-SPECT ventilation imagery. The results from this small cohort of patients indicate that single inhalation, single energy Xe-CT has the potential to quantify regional lung ventilation volumetrically with high resolution using widely accessible radiologic equipment. Bill Loo and Peter Maxim are founders of TibaRay, Inc. Bill Loo is also a board member. Bill Loo and Peter Maxim have received research grants from Varian Medical Systems, Inc. and RaySearch Laboratory.« less

Augmentation of linear facial anthropometrics through modern morphometrics: a facial convexity example.

PubMed

Wei, R; Claes, P; Walters, M; Wholley, C; Clement, J G

2011-06-01

The facial region has traditionally been quantified using linear anthropometrics. These are well established in dentistry, but require expertise to be used effectively. The aim of this study was to augment the utility of linear anthropometrics by applying them in conjunction with modern 3-D morphometrics. Facial images of 75 males and 94 females aged 18-25 years with self-reported Caucasian ancestry were used. An anthropometric mask was applied to establish corresponding quasi-landmarks on the images in the dataset. A statistical face-space, encoding shape covariation, was established. The facial median plane was extracted facilitating both manual and automated indication of commonly used midline landmarks. From both indications, facial convexity angles were calculated and compared. The angles were related to the face-space using a regression based pathway enabling the visualization of facial form associated with convexity variation. Good agreement between the manual and automated angles was found (Pearson correlation: 0.9478-0.9474, Dahlberg root mean squared error: 1.15°-1.24°). The population mean angle was 166.59°-166.29° (SD 5.09°-5.2°) for males-females. The angle-pathway provided valuable feedback. Linear facial anthropometrics can be extended when used in combination with a face-space derived from 3-D scans and the exploration of property pathways inferred in a statistically verifiable way. © 2011 Australian Dental Association.

Prediction of HDR quality by combining perceptually transformed display measurements with machine learning

NASA Astrophysics Data System (ADS)

Choudhury, Anustup; Farrell, Suzanne; Atkins, Robin; Daly, Scott

2017-09-01

We present an approach to predict overall HDR display quality as a function of key HDR display parameters. We first performed subjective experiments on a high quality HDR display that explored five key HDR display parameters: maximum luminance, minimum luminance, color gamut, bit-depth and local contrast. Subjects rated overall quality for different combinations of these display parameters. We explored two models | a physical model solely based on physically measured display characteristics and a perceptual model that transforms physical parameters using human vision system models. For the perceptual model, we use a family of metrics based on a recently published color volume model (ICT-CP), which consists of the PQ luminance non-linearity (ST2084) and LMS-based opponent color, as well as an estimate of the display point spread function. To predict overall visual quality, we apply linear regression and machine learning techniques such as Multilayer Perceptron, RBF and SVM networks. We use RMSE and Pearson/Spearman correlation coefficients to quantify performance. We found that the perceptual model is better at predicting subjective quality than the physical model and that SVM is better at prediction than linear regression. The significance and contribution of each display parameter was investigated. In addition, we found that combined parameters such as contrast do not improve prediction. Traditional perceptual models were also evaluated and we found that models based on the PQ non-linearity performed better.

Rate of occurrence, gross appearance, and age relation of hyperostosis frontalis interna in females: a prospective autopsy study.

PubMed

Nikolić, Slobodan; Djonić, Danijela; Zivković, Vladimir; Babić, Dragan; Juković, Fehim; Djurić, Marija

2010-09-01

The aim of our study was to determine rate of occurrence and appearance of hyperostosis frontalis interna (HFI) in females and correlation of this phenomenon with ageing. The sample included 248 deceased females: 45 of them with different types of HFI, and 203 without HFI, average age 68.3 +/- 15.4 years (range, 19-93), and 58.2 +/- 20.2 years (range, 10-101), respectively. According to our results, the rate of HFI was 18.14%. The older the woman was, the higher the possibility of HFI occurring (Pearson correlation 0.211, N=248, P=0.001), but the type of HFI did not correlate with age (Pearson correlation 0.229, N=45, P=0.131). Frontal and temporal bone were significantly thicker in women with than in women without HFI (t= -10.490, DF=246, P=0.000, and t= -5.658, DF=246, P=0.000, respectively). These bones became thicker with ageing (Pearson correlation 0.178, N=248, P=0.005, and 0.303, N=248, P=0.000, respectively). The best predictors of HFI occurrence were respectively, frontal bone thickness, temporal bone thickness, and age(Wald. coeff.=35.487, P=0.000; Wald. coeff.=3.288, P=0.070, and Wald.coeff. =2.727, P =0.099). Diagnosis of HFI depends not only on frontal bone thickness, but also on waviness of internal plate of the frontal bone, as well as-the involvement of the inner bone surface.

Evaluating resin-enamel bonds by microshear and microtensile bond strength tests: effects of composite resin

PubMed Central

de ANDRADE, Andrea Mello; MOURA, Sandra Kiss; REIS, Alessandra; LOGUERCIO, Alessandro Dourado; GARCIA, Eugenio Jose; GRANDE, Rosa Helena Miranda

2010-01-01

Objectives The aims of this study were to evaluate the effect of resin composite (Filtek Z250 and Filtek Flow Z350) and adhesive system [(Solobond Plus, Futurabond NR (VOCO) and Adper Single Bond (3M ESPE)] on the microtensile (µTBS) and microshear bond strength (µSBS) tests on enamel, and to correlate the bond strength means between them. Material and methods Thirty-six extracted human molars were sectioned to obtain two tooth halves: one for µTBS and the other one for µSBS. Adhesive systems and resin composites were applied to the enamel ground surfaces and light-cured. After storage (37ºC/24 h) specimens were stressed (0.5 mm/ min). Fracture modes were analyzed under scanning electron microscopy. The data were analyzed using two-way ANOVA and Tukey's test (α=0.05). Results The correlation between tests was estimated with Pearson's product-moment correlation statistics (α =0.05). For both tests only the main factor resin composite was statistically significant (p<0.05). The correlation test detected a positive (r=0.91) and significant (p=0.01) correlation between the tests. Conclusions The results were more influenced by the resin type than by the adhesives. Both microbond tests seem to be positive and linearly correlated and can therefore lead to similar conclusions. PMID:21308290

Prospective evaluation of a bivalirudin to warfarin transition nomogram.

PubMed

Hohlfelder, Benjamin; Sylvester, Katelyn W; Rimsans, Jessica; DeiCicchi, David; Connors, Jean M

2017-05-01

Bivalirudin may cause a falsely prolonged international normalized ratio (INR) that complicates the discontinuation of bivalirudin when used as a bridge to warfarin. To prospectively validate our novel bivalirudin to warfarin transition nomogram, adult patients who received bivalirudin as a bridge to warfarin between July 2015 and June 2016 were prospectively evaluated, utilizing our predictive nomogram. The major outcome of our analysis was the correlation between the predicted change in INR upon bivalirudin discontinuation based on the nomogram, and the actual change in INR upon bivalirudin discontinuation. The major outcome was analyzed using the Pearson's correlation test. A Pearson's correlation coefficient >0.6 was considered to be a strong correlation. Bivalirudin was used as a bridge to warfarin in 29 patients. The majority of patients (86%) included in the analysis had a ventricular assist device. The median initial bivalirudin rate was 0.07 mg/kg/h and the mean increase in INR when starting bivalirudin was 0.6. The mean final weight-based bivalirudin rate was 0.08 mg/kg/h and the mean change in INR after stopping bivalirudin was 0.7. The Pearson correlation coefficient between the predicted change in INR upon bivalirudin discontinuation and the actual change in INR upon bivalirudin discontinuation was 0.86 (p < 0.001). After bivalirudin discontinuation, 68% of patients had a therapeutic INR. The results of this prospective analysis successfully validated our novel bivalirudin to warfarin transition nomogram. There was a very strong correlation between the predicted change and actual change in INR upon bivalirudin discontinuation.

Influence of Landmarks on Spatial Memory in Short-nosed Fruit Bat, Cynopterus sphinx.

PubMed

Zeng, Yu; Zhang, Xin-Wen; Zhu, Guang-Jian; Gong, Yan-Yan; Yang, Jian; Zhang, Li-Biao

2010-04-01

In order to study the relationship between landmarks and spatial memory in short-nosed fruit bat, Cynopterus sphinx (Megachiroptera, Pteropodidae), we simulated a foraging environment in the laboratory. Different landmarks were placed to gauge the spatial memory of C. sphinx. We changed the number of landmarks every day with 0 landmarks again on the fifth day (from 0, 2, 4, 8 to 0). Individuals from the control group were exposed to the identical artificial foraging environment, but without landmarks. The results indicated that there was significant correlation between the time of the first foraging and the experimental days in both groups (Pearson Correlation: experimental group: r=-0.593, P<0.01; control group: r=-0.581, P<0.01). There was no significant correlation between the success rates of foraging and the experimental days in experimental groups (Pearson Correlation: r=0.177, P>0.05), but there was significant correlation between the success rates of foraging and the experimental days in the control groups (Pearson Correlation: r=0.445, P<0.05). There was no significant difference for the first foraging time between experimental and control groups (GLM: F(0.05,1 )=4.703, P>0.05); also, there was no significant difference in success rates of foraging between these two groups (GLM: F(0.05,1 )=0.849, P>0.05). The results of our experiment suggest that spatial memory in C. sphinx was formed gradually and that the placed landmarks appeared to have no discernable effects on the memory of the foraging space.

Relations between Brain Structure and Attentional Function in Spina Bifida: Utilization of Robust Statistical Approaches

PubMed Central

Kulesz, Paulina A.; Tian, Siva; Juranek, Jenifer; Fletcher, Jack M.; Francis, David J.

2015-01-01

Objective Weak structure-function relations for brain and behavior may stem from problems in estimating these relations in small clinical samples with frequently occurring outliers. In the current project, we focused on the utility of using alternative statistics to estimate these relations. Method Fifty-four children with spina bifida meningomyelocele performed attention tasks and received MRI of the brain. Using a bootstrap sampling process, the Pearson product moment correlation was compared with four robust correlations: the percentage bend correlation, the Winsorized correlation, the skipped correlation using the Donoho-Gasko median, and the skipped correlation using the minimum volume ellipsoid estimator Results All methods yielded similar estimates of the relations between measures of brain volume and attention performance. The similarity of estimates across correlation methods suggested that the weak structure-function relations previously found in many studies are not readily attributable to the presence of outlying observations and other factors that violate the assumptions behind the Pearson correlation. Conclusions Given the difficulty of assembling large samples for brain-behavior studies, estimating correlations using multiple, robust methods may enhance the statistical conclusion validity of studies yielding small, but often clinically significant, correlations. PMID:25495830

Relations between volumetric measures of brain structure and attentional function in spina bifida: utilization of robust statistical approaches.

PubMed

Kulesz, Paulina A; Tian, Siva; Juranek, Jenifer; Fletcher, Jack M; Francis, David J

2015-03-01

Weak structure-function relations for brain and behavior may stem from problems in estimating these relations in small clinical samples with frequently occurring outliers. In the current project, we focused on the utility of using alternative statistics to estimate these relations. Fifty-four children with spina bifida meningomyelocele performed attention tasks and received MRI of the brain. Using a bootstrap sampling process, the Pearson product-moment correlation was compared with 4 robust correlations: the percentage bend correlation, the Winsorized correlation, the skipped correlation using the Donoho-Gasko median, and the skipped correlation using the minimum volume ellipsoid estimator. All methods yielded similar estimates of the relations between measures of brain volume and attention performance. The similarity of estimates across correlation methods suggested that the weak structure-function relations previously found in many studies are not readily attributable to the presence of outlying observations and other factors that violate the assumptions behind the Pearson correlation. Given the difficulty of assembling large samples for brain-behavior studies, estimating correlations using multiple, robust methods may enhance the statistical conclusion validity of studies yielding small, but often clinically significant, correlations. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Can Twitter Be a Source of Information on Allergy? Correlation of Pollen Counts with Tweets Reporting Symptoms of Allergic Rhinoconjunctivitis and Names of Antihistamine Drugs.

PubMed

Gesualdo, Francesco; Stilo, Giovanni; D'Ambrosio, Angelo; Carloni, Emanuela; Pandolfi, Elisabetta; Velardi, Paola; Fiocchi, Alessandro; Tozzi, Alberto E

2015-01-01

Pollen forecasts are in use everywhere to inform therapeutic decisions for patients with allergic rhinoconjunctivitis (ARC). We exploited data derived from Twitter in order to identify tweets reporting a combination of symptoms consistent with a case definition of ARC and those reporting the name of an antihistamine drug. In order to increase the sensitivity of the system, we applied an algorithm aimed at automatically identifying jargon expressions related to medical terms. We compared weekly Twitter trends with National Allergy Bureau weekly pollen counts derived from US stations, and found a high correlation of the sum of the total pollen counts from each stations with tweets reporting ARC symptoms (Pearson's correlation coefficient: 0.95) and with tweets reporting antihistamine drug names (Pearson's correlation coefficient: 0.93). Longitude and latitude of the pollen stations affected the strength of the correlation. Twitter and other social networks may play a role in allergic disease surveillance and in signaling drug consumptions trends.

Cone-beam computed tomography for lung cancer - validation with CT and monitoring tumour response during chemo-radiation therapy.

PubMed

Michienzi, Alissa; Kron, Tomas; Callahan, Jason; Plumridge, Nikki; Ball, David; Everitt, Sarah

2017-04-01

Cone-beam computed tomography (CBCT) is a valuable image-guidance tool in radiation therapy (RT). This study was initiated to assess the accuracy of CBCT for quantifying non-small cell lung cancer (NSCLC) tumour volumes compared to the anatomical 'gold standard', CT. Tumour regression or progression on CBCT was also analysed. Patients with Stage I-III NSCLC, prescribed 60 Gy in 30 fractions RT with concurrent platinum-based chemotherapy, routine CBCT and enrolled in a prospective study of serial PET/CT (baseline, weeks two and four) were eligible. Time-matched CBCT and CT gross tumour volumes (GTVs) were manually delineated by a single observer on MIM software, and were analysed descriptively and using Pearson's correlation coefficient (r) and linear regression (R 2 ). Of 94 CT/CBCT pairs, 30 patients were eligible for inclusion. The mean (± SD) CT GTV vs CBCT GTV on the four time-matched pairs were 95 (±182) vs 98.8 (±160.3), 73.6 (±132.4) vs 70.7 (±96.6), 54.7 (±92.9) vs 61.0 (±98.8) and 61.3 (±53.3) vs 62.1 (±47.9) respectively. Pearson's correlation coefficient (r) was 0.98 (95% CI 0.97-0.99, ρ < 0.001). The mean (±SD) CT/CBCT Dice's similarity coefficient was 0.66 (±0.16). Of 289 CBCT scans, tumours in 27 (90%) patients regressed by a mean (±SD) rate of 1.5% (±0.75) per fraction. The mean (±SD) GTV regression was 43.1% (±23.1) from the first to final CBCT. Primary lung tumour volumes observed on CBCT and time-matched CT are highly correlated (although not identical), thereby validating observations of GTV regression on CBCT in NSCLC. © 2016 The Royal Australian and New Zealand College of Radiologists.

Determination of dioxins and polychlorinated biphenyls in breast milk, maternal blood and cord blood from residents of Tohoku, Japan.

PubMed

Nakamura, Tomoyuki; Nakai, Kunihiko; Matsumura, Tohru; Suzuki, Shigeru; Saito, Yoshinori; Satoh, Hiroshi

2008-05-01

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) are bioaccumulative chemicals that are considered to be toxic contaminants based on several epidemiological studies. To elucidate exposure levels of these chemicals in the present study, concentrations of PCDD/DFs, dioxin-like PCBs (DL-PCBs) and PCBs in breast milk, maternal blood and cord blood obtained from the same participants registered in a birth cohort study in Tohoku, Japan, were measured. Congener-specific analysis revealed several differences in minor congeners of these compounds among the three specimen types, although major congeners were detected in the specimens. The toxicity equivalence quantity concentrations (1998 WHO-TEF) and PCBs in breast milk, maternal blood and cord blood on the whole and on a lipid basis were in the order of breast milk > maternal blood > cord blood. Pearson's correlation coefficients of TEQs and total PCBs among the three specimens were high, with the correlation coefficient of TEQ between breast milk and maternal blood being the highest (r=0.94, p<0.001). On the other hand, the TEQ between breast milk and cord blood was the lowest (r=0.79, p<0.001). Pearson's correlation coefficient between the TEQ and PCBs in each specimen was also high (r=0.82-0.95, p<0.001). The associations of chemical concentrations with maternal age, parity, fish intake, BMI and the rate of body weight increase during pregnancy were analyzed with multiple linear regression analysis. TEQ concentrations and PCBs were negatively associated with parity (p<0.05), and maternal age was positively associated with PCBs (p<0.05). However, the associations with BMI and fish intake during pregnancy were not significant. These results suggest that parity is an important factor affecting the concentrations of dioxins and PCBs in these specimens.

Relationship between perceived social support and self-care behavior in type 2 diabetics: A cross-sectional study

PubMed Central

Mohebi, Siamak; Parham, Mahmoud; Sharifirad, Gholamreza; Gharlipour, Zabihollah; Mohammadbeigi, Abolfazl; Rajati, Fatemeh

2018-01-01

BACKGROUND: Social support is one of the most effective factors on the diabetic self-care. This study aimed to assess social support and its relationship to self-care in type 2 diabetic patients in Qom, Iran. STUDY DESIGN: A cross-sectional study was conducted on 325 diabetics attending the Diabetes Mellitus Association. METHODS: Patients who meet inclusion and exclusion criteria were selected using random sampling method. Data were collected by the Summary of Diabetes Self-Care Activities and Multidimensional Scale of Perceived Social Support, with hemoglobin A1C test. Data were analyzed using descriptive statistics and independent t-test, analysis of variance, Pearson correlation, and linear regression test, using 0.05 as the critical significance level, provided by SPSS software. RESULTS: The mean and standard deviation of self-care and social support scores were 4.31 ± 2.7 and 50.32 ± 11.09, respectively. The mean level of glycosylated hemoglobin (HbA1C) of patients was 7.54. There was a significant difference between mean score of self-care behaviors and social support according to gender and marital status (P < 0.05). The regression analysis showed that disease duration was the only variable which had a significant effect on the level of HbA1C (P < 0.001). Pearson correlation coefficient indicated that self-care and social support significantly correlated (r = 0.489, P > 0.001) and also predictive power of social support was 0.28. Self-care was significantly better in diabetics with HbA1C ≤7%. Patients who had higher HbA1C felt less, but not significant, social support. CONCLUSIONS: This study indicated the relationship between social support and self-care behaviors in type 2 diabetic patients. Interventions that focus on improving the social support and self-care of diabetic control may be more effective in improving glycemic control. PMID:29693029

Relationship between perceived social support and self-care behavior in type 2 diabetics: A cross-sectional study.

PubMed

Mohebi, Siamak; Parham, Mahmoud; Sharifirad, Gholamreza; Gharlipour, Zabihollah; Mohammadbeigi, Abolfazl; Rajati, Fatemeh

2018-01-01

Social support is one of the most effective factors on the diabetic self-care. This study aimed to assess social support and its relationship to self-care in type 2 diabetic patients in Qom, Iran. A cross-sectional study was conducted on 325 diabetics attending the Diabetes Mellitus Association. Patients who meet inclusion and exclusion criteria were selected using random sampling method. Data were collected by the Summary of Diabetes Self-Care Activities and Multidimensional Scale of Perceived Social Support, with hemoglobin A 1 C test. Data were analyzed using descriptive statistics and independent t -test, analysis of variance, Pearson correlation, and linear regression test, using 0.05 as the critical significance level, provided by SPSS software. The mean and standard deviation of self-care and social support scores were 4.31 ± 2.7 and 50.32 ± 11.09, respectively. The mean level of glycosylated hemoglobin (HbA 1 C) of patients was 7.54. There was a significant difference between mean score of self-care behaviors and social support according to gender and marital status ( P < 0.05). The regression analysis showed that disease duration was the only variable which had a significant effect on the level of HbA 1 C ( P < 0.001). Pearson correlation coefficient indicated that self-care and social support significantly correlated ( r = 0.489, P > 0.001) and also predictive power of social support was 0.28. Self-care was significantly better in diabetics with HbA 1 C ≤7%. Patients who had higher HbA 1 C felt less, but not significant, social support. This study indicated the relationship between social support and self-care behaviors in type 2 diabetic patients. Interventions that focus on improving the social support and self-care of diabetic control may be more effective in improving glycemic control.

Further Examination of the Reliability of the Modified Rathus Assertiveness Schedule.

ERIC Educational Resources Information Center

Del Greco, Linda; And Others

1986-01-01

Examined the reliability of the 30-item Modified Rathus Assertiveness Schedule (MRAS) using the test-retest method over a three-week period. The MRAS yielded correlations of .74 using the Pearson product and Spearman Brown correlation coefficient. Correlations for males yielded .77 and .72. For females correlations for both tests were .72.…

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…

Direct Estimation of Correlation as a Measure of Association Strength Using Multidimensional Item Response Models

ERIC Educational Resources Information Center

Wang, Wen-Chung

2004-01-01

The Pearson correlation is used to depict effect sizes in the context of item response theory. Amultidimensional Rasch model is used to directly estimate the correlation between latent traits. Monte Carlo simulations were conducted to investigate whether the population correlation could be accurately estimated and whether the bootstrap method…

Why conventional detection methods fail in identifying the existence of contamination events.

PubMed

Liu, Shuming; Li, Ruonan; Smith, Kate; Che, Han

2016-04-15

Early warning systems are widely used to safeguard water security, but their effectiveness has raised many questions. To understand why conventional detection methods fail to identify contamination events, this study evaluates the performance of three contamination detection methods using data from a real contamination accident and two artificial datasets constructed using a widely applied contamination data construction approach. Results show that the Pearson correlation Euclidean distance (PE) based detection method performs better for real contamination incidents, while the Euclidean distance method (MED) and linear prediction filter (LPF) method are more suitable for detecting sudden spike-like variation. This analysis revealed why the conventional MED and LPF methods failed to identify existence of contamination events. The analysis also revealed that the widely used contamination data construction approach is misleading. Copyright © 2016 Elsevier Ltd. All rights reserved.

3-dimensional computed tomographic analysis of the pharynx in adult patients with unrepaired isolated cleft palate.

PubMed

Xu, Yi; Zhao, Shufan; Shi, Jiayu; Wang, Yan; Shi, Bing; Zheng, Qian; Lo, Lun-Jou

2013-08-01

This study investigated 3D differences of the pharynx in adult patients with unrepaired isolated cleft palate (ICP) versus normal adults using cone-beam computed tomography (CBCT). CBCT data of 32 adult patients with nonsyndromic unrepaired ICP and 30 normal controls were acquired. Image processing and analyses were performed using Mimics (Materialise NV, Leuven, Belgium). Linear, planar, and volumetric measurements and comparisons were performed between patients with ICP and controls. Interobserver and intraobserver reliabilities of 3D pharyngeal analysis were determined by the Pearson correlation coefficient. Statistical analyses comparing patients with ICP to normal adults were performed using independent-samples t test, with the significance threshold set at P = .05. Interobserver and intraobserver reliabilities were high. Pearson correlation coefficients ranged from 0.992 to 0.999 for interobserver measurements and from 0.994 to 0.999 for intraobserver measurements. Anterior height (P = .000), total depth (P = .003), and floor length (P = .034) of the bony nasopharynx; posteroanterior diameter of the pharyngeal airway at the palatal plane (P = .000); cross-sectional area of the pharyngeal airway at the palatal plane (P = .000); total volume (P = .031); volume above the palatal plane (P = .024); and the volume between the palatal plane and the plane of the most anterior point on the inferior margin of the outline of the body of the second cervical vertebra (P = .022) were larger in patients with ICP. This imaging study showed an enlarged nasopharynx in the sagittal plane and increased nasopharyngeal airway volume at the palatal plane in patients with ICP. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

The Effects of Increasing Ocular Surface Stimulation on Blinking and Sensation

PubMed Central

Wu, Ziwei; Begley, Carolyn G.; Situ, Ping; Simpson, Trefford

2014-01-01

Purpose. The purpose of this study was to determine how increasing ocular surface stimulation affected blinking and sensation, while controlling task concentration. Methods. Ten healthy subjects concentrated on a task while a custom pneumatic device generated air flow toward the central cornea. Six flow rates (FRs) were randomly presented three times each and subjects used visual analog scales to record their sensory responses. The interblink interval (IBI) and the FR were recorded simultaneously and the IBI, sensory response, and corresponding FR were determined for each trial. The FR associated with a statistically significant decrease in IBI, the blink increase threshold (BIT), was calculated for each subject. Results. Both the mean and SD of IBI were decreased with increasing stimulation, from 5.69 ± 3.96 seconds at baseline to 1.02 ± 0.37 seconds at maximum stimulation. The average BIT was 129 ± 20 mL/min flow rate with an IBI of 2.33 ± 1.10 seconds (permutation test, P < 0.001). After log transformation, there was a significant linear function between increasing FR and decreasing IBI within each subject (Pearson's r ≤ −0.859, P < 0.05). The IBI was highly correlated with wateriness, discomfort, and cooling ratings (Pearson's r ≤ −0.606, P < 0.001). Conclusions. There was a dose-response–like relationship between increased surface stimulation and blinking in healthy subjects, presumably for protection of the ocular surface. The blink response was highly correlated with ocular surface sensation, which is not surprising given their common origins. The BIT, a novel metric, may provide an additional end point for studies on dry eye or other conditions. PMID:24557346

Blood lead is a predictor of homocysteine levels in a population-based study of older adults.

PubMed

Schafer, Jyme H; Glass, Thomas A; Bressler, Joseph; Todd, Andrew C; Schwartz, Brian S

2005-01-01

Lead and homocysteine are both associated with cardiovascular disease and cognitive dysfunction. We evaluated the relations among blood lead, tibia lead, and homocysteine levels by cross-sectional analysis of data among subjects in the Baltimore Memory Study, a longitudinal study of 1,140 randomly selected residents in Baltimore, Maryland, who were 50-70 years of age. Tibia lead was measured by (superscript)109(/superscript)Cd K-shell X-ray fluorescence. The subject population had a mean +/- SD age of 59.3 +/- 5.9 years and was 66.0% female, 53.9% white, and 41.4% black or African American. Mean +/- SD blood lead, tibia lead, and homocysteine levels were 3.5 +/- 2.4 microg/dL, 18.9 +/- 12.5 microg/g, and 10.0 +/- 4.1 micromol/L, respectively. In unadjusted analysis, blood lead and homocysteine were moderately correlated (Pearson's r = 0.27, p < 0.01). After adjustment for age, sex, race/ethnicity, educational level, tobacco and alcohol consumption, and body mass index using multiple linear regression, results revealed that homocysteine levels increased 0.35 micromol/L per 1.0 microg/dL increase in blood lead (p < 0.01). The relations of blood lead with homocysteine levels did not differ in subgroups distinguished by age, sex, or race/ethnicity. Tibia lead was modestly correlated with blood lead (Pearson's r = 0.12, p < 0.01) but was not associated with homocysteine levels. To our knowledge, these are the first data to reveal an association between blood lead and homocysteine. These results suggest that homocysteine could be a mechanism that underlies the effects of lead on the cardiovascular and central nervous systems, possibly offering new targets for intervention to prevent the long-term consequences of lead exposure.

Employing the Gini coefficient to measure participation inequality in treatment-focused Digital Health Social Networks.

PubMed

van Mierlo, Trevor; Hyatt, Douglas; Ching, Andrew T

2016-01-01

Digital Health Social Networks (DHSNs) are common; however, there are few metrics that can be used to identify participation inequality. The objective of this study was to investigate whether the Gini coefficient, an economic measure of statistical dispersion traditionally used to measure income inequality, could be employed to measure DHSN inequality. Quarterly Gini coefficients were derived from four long-standing DHSNs. The combined data set included 625,736 posts that were generated from 15,181 actors over 18,671 days. The range of actors (8-2323), posts (29-28,684), and Gini coefficients (0.15-0.37) varied. Pearson correlations indicated statistically significant associations between number of actors and number of posts (0.527-0.835, p  < .001), and Gini coefficients and number of posts (0.342-0.725, p  < .001). However, the association between Gini coefficient and number of actors was only statistically significant for the addiction networks (0.619 and 0.276, p  < .036). Linear regression models had positive but mixed R 2 results (0.333-0.527). In all four regression models, the association between Gini coefficient and posts was statistically significant ( t  = 3.346-7.381, p  < .002). However, unlike the Pearson correlations, the association between Gini coefficient and number of actors was only statistically significant in the two mental health networks ( t  = -4.305 and -5.934, p  < .000). The Gini coefficient is helpful in measuring shifts in DHSN inequality. However, as a standalone metric, the Gini coefficient does not indicate optimal numbers or ratios of actors to posts, or effective network engagement. Further, mixed-methods research investigating quantitative performance metrics is required.

Impact of Autocorrelation on Functional Connectivity

PubMed Central

Arbabshirani, Mohammad R.; Damaraju, Eswar; Phlypo, Ronald; Plis, Sergey; Allen, Elena; Ma, Sai; Mathalon, Daniel; Preda, Adrian; Vaidya, Jatin G.; Adali, Tülay; Calhoun, Vince D.

2014-01-01

Although the impact of serial correlation (autocorrelation) in residuals of general linear models for fMRI time-series has been studied extensively, the effect of autocorrelation on functional connectivity studies has been largely neglected until recently. Some recent studies based on results from economics have questioned the conventional estimation of functional connectivity and argue that not correcting for autocorrelation in fMRI time-series results in “spurious” correlation coefficients. In this paper, first we assess the effect of autocorrelation on Pearson correlation coefficient through theoretical approximation and simulation. Then we present this effect on real fMRI data. To our knowledge this is the first work comprehensively investigating the effect of autocorrelation on functional connectivity estimates. Our results show that although FC values are altered, even following correction for autocorrelation, results of hypothesis testing on FC values remain very similar to those before correction. In real data we show this is true for main effects and also for group difference testing between healthy controls and schizophrenia patients. We further discuss model order selection in the context of autoregressive processes, effects of frequency filtering and propose a preprocessing pipeline for connectivity studies. PMID:25072392

Cold perception and cutaneous microvascular response to local cooling at different cooling temperatures.

PubMed

Music, Mark; Finderle, Zarko; Cankar, Ksenija

2011-05-01

The aim of the present study was to investigate the effect of quantitatively measured cold perception (CP) thresholds on microcirculatory response to local cooling as measured by direct and indirect response of laser-Doppler (LD) flux during local cooling at different temperatures. The CP thresholds were measured in 18 healthy males using the Marstock method (thermode placed on the thenar). The direct (at the cooling site) and indirect (on contralateral hand) LD flux responses were recorded during immersion of the hand in a water bath at 20°C, 15°C, and 10°C. The cold perception threshold correlated (linear regression analysis, Pearson correlation) with the indirect LD flux response at cooling temperatures 20°C (r=0.782, p<0.01) and 15°C (r=0.605, p<0.01). In contrast, there was no correlation between the CP threshold and the indirect LD flux response during cooling in water at 10°C. The results demonstrate that during local cooling, depending on the cooling temperature used, cold perception threshold influences indirect LD flux response. Copyright © 2011 Elsevier Inc. All rights reserved.

Detecting and Quantifying Topography in Neural Maps

PubMed Central

Yarrow, Stuart; Razak, Khaleel A.; Seitz, Aaron R.; Seriès, Peggy

2014-01-01

Topographic maps are an often-encountered feature in the brains of many species, yet there are no standard, objective procedures for quantifying topography. Topographic maps are typically identified and described subjectively, but in cases where the scale of the map is close to the resolution limit of the measurement technique, identifying the presence of a topographic map can be a challenging subjective task. In such cases, an objective topography detection test would be advantageous. To address these issues, we assessed seven measures (Pearson distance correlation, Spearman distance correlation, Zrehen's measure, topographic product, topological correlation, path length and wiring length) by quantifying topography in three classes of cortical map model: linear, orientation-like, and clusters. We found that all but one of these measures were effective at detecting statistically significant topography even in weakly-ordered maps, based on simulated noisy measurements of neuronal selectivity and sparse sampling of the maps. We demonstrate the practical applicability of these measures by using them to examine the arrangement of spatial cue selectivity in pallid bat A1. This analysis shows that significantly topographic arrangements of interaural intensity difference and azimuth selectivity exist at the scale of individual binaural clusters. PMID:24505279

Serum biomarkers of habitual coffee consumption may provide insight into the mechanism underlying the association between coffee consumption and colorectal cancer12345

PubMed Central

Guertin, Kristin A; Loftfield, Erikka; Boca, Simina M; Sampson, Joshua N; Moore, Steven C; Xiao, Qian; Huang, Wen-Yi; Xiong, Xiaoqin; Freedman, Neal D; Cross, Amanda J; Sinha, Rashmi

2015-01-01

Background: Coffee intake may be inversely associated with colorectal cancer; however, previous studies have been inconsistent. Serum coffee metabolites are integrated exposure measures that may clarify associations with cancer and elucidate underlying mechanisms. Objectives: Our aims were 2-fold as follows: 1) to identify serum metabolites associated with coffee intake and 2) to examine these metabolites in relation to colorectal cancer. Design: In a nested case-control study of 251 colorectal cancer cases and 247 matched control subjects from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we conducted untargeted metabolomics analyses of baseline serum by using ultrahigh-performance liquid-phase chromatography–tandem mass spectrometry and gas chromatography–mass spectrometry. Usual coffee intake was self-reported in a food-frequency questionnaire. We used partial Pearson correlations and linear regression to identify serum metabolites associated with coffee intake and conditional logistic regression to evaluate associations between coffee metabolites and colorectal cancer. Results: After Bonferroni correction for multiple comparisons (P = 0.05 ÷ 657 metabolites), 29 serum metabolites were positively correlated with coffee intake (partial correlation coefficients: 0.18–0.61; P < 7.61 × 10−5); serum metabolites most highly correlated with coffee intake (partial correlation coefficients >0.40) included trigonelline (N′-methylnicotinate), quinate, and 7 unknown metabolites. Of 29 serum metabolites, 8 metabolites were directly related to caffeine metabolism, and 3 of these metabolites, theophylline (OR for 90th compared with 10th percentiles: 0.44; 95% CI: 0.25, 0.79; P-linear trend = 0.006), caffeine (OR for 90th compared with 10th percentiles: 0.56; 95% CI: 0.35, 0.89; P-linear trend = 0.015), and paraxanthine (OR for 90th compared with 10th percentiles: 0.58; 95% CI: 0.36, 0.94; P-linear trend = 0.027), were inversely associated with colorectal cancer. Conclusions: Serum metabolites can distinguish coffee drinkers from nondrinkers; some caffeine-related metabolites were inversely associated with colorectal cancer and should be studied further to clarify the role of coffee in the cause of colorectal cancer. The Prostate, Lung, Colorectal, and Ovarian trial was registered at clinicaltrials.gov as NCT00002540. PMID:25762808

The relationship between allometry and preferred transition speed in human locomotion.

PubMed

Ranisavljev, Igor; Ilic, Vladimir; Soldatovic, Ivan; Stefanovic, Djordje

2014-04-01

The purpose of this study was to explore the relationships between preferred transition speed (PTS) and anthropometric characteristics, body composition and different human body proportions in males. In a sample of 59 male students, we collected anthropometric and body composition data and determined individual PTS using increment protocol. The relationships between PTS and other variables were determined using Pearson correlation, stepwise linear and hierarchical regression. Body ratios were formed as quotient of two variables whereby at least one significantly correlated to PTS. Circular and transversal (except bitrochanteric diameter) body dimensions did not correlate with PTS. Moderate correlations were found between longitudinal leg dimensions (foot, leg and thigh length) and PTS, while the highest correlation was found for lower leg length (r=.488, p<.01). Two parameters related to body composition showed weak correlation with PTS: body fat mass (r=-.250, p<.05) and amount of lean leg mass scaled to body weight (r=.309, p<.05). Segmental body proportions correlated more significantly with PTS, where thigh/lower leg length ratio showed the highest correlation (r=.521, p<.01). Prediction model with individual variables (lower leg and foot length) have explained just 31% of PTS variability, while model with body proportions showed almost 20% better prediction (R(2)=.504). These results suggests that longitudinal leg dimensions have moderate influence on PTS and that segmental body proportions significantly more explain PTS than single anthropometric variables. Copyright © 2014 Elsevier B.V. All rights reserved.

Distance M-Me: A novel parameter having significant potential as a predictor of mandibular growth.

PubMed

Jain, Parul; Kaul, Rahul; Mukhopadhyay, Santanu; Saha, Subrata; Sarkar, Subir

2017-01-01

The purpose of the present study was to investigate the relationship of the measured distance between two mandibular points (distance M-Me) to chronological age and to find out whether the absolute values of distance M-Me could be classified age-wise into a unique range, which could be directly read for predicting the stage of mandibular growth. The study sample consists of lateral cephalometric records of 65 patients (34 females and 31 males; age range: 6-21 years). Chronological age was calculated in decimal years. Lateral cephalograms were assessed by two independent examiners. Points M and Me were located on the lateral cephalograms, and linear distance between them was measured. Pearson product-moment correlation coefficients showed a high correlation between chronological age and distance M-Me (0.746 for females and 0.869 for males, p < 0.01). When the values of distance M-Me were compared with chronological age, it was possible to make four age groups (for females and males separately), where each group showed a unique range of value for distance M-Me. The values increased with increasing age. Increase in value of distance M-Me with age, showing reduced individual variation, depicts a well-conserved linear dimension. Values of distance M-Me can be directly read for predicting the stage of mandibular growth and can be used as a valuable adjunct or substitute to chronological age.

Self-rated and observer-rated measures of well-being and distress in adolescence: an exploratory study.

PubMed

Vescovelli, Francesca; Albieri, Elisa; Ruini, Chiara

2014-01-01

The evaluation of eudaimonic well-being in adolescence is hampered by the lack of specific assessment tools. Moreover, with younger populations, the assessment of positive functioning may be biased by self-report data only, and may be more accurate by adding significant adults' evaluations. The objective of this research was to measure adolescents' well-being and prosocial behaviours using self-rated and observer-rated instruments, and their pattern of associations. The sample included 150 Italian high school adolescents. Observed-evaluation was performed by their school teachers using the Strengths and Difficulties Questionnaire. Adolescents completed Ryff's Psychological Well-being Scales and Symptom Questionnaire. Pearson' r correlations and Linear regression were performed. Self-rated dimensions of psychological well-being significantly correlated with all observer-rated dimensions, but Strengths and Difficulties Emotional symptom scale. Multiple linear regression showed that the self-rated dimensions Environmental Mastery and Personal Growth, and surprisingly not Positive Relations, are related to the observer-rated dimension Prosocial Behaviour. Adolescents with higher levels of well-being in specific dimensions tend to be perceived as less problematic by their teachers. However, some dimensions of positive functioning present discrepancies between self and observer-rated instruments. Thus, the conjunct use of self-reports and observer-rated tools for a more comprehensive assessment of students' eudaimonic well-being is recommended.

Predictors of cervical lordosis loss after laminoplasty in patients with cervical spondylotic myelopathy.

PubMed

Zhang, Jing Tao; Li, Jia Qi; Niu, Rui Jie; Liu, Zhao; Tong, Tong; Shen, Yong

2017-04-01

To determine whether radiological, clinical, and demographic findings in patients with cervical spondylotic myelopathy (CSM) were independently associated with loss of cervical lordosis (LCL) after laminoplasty. The prospective study included 41 consecutive patients who underwent laminoplasty for CSM. The difference in C2-7 Cobb angle between the postoperative and preoperative films was used to evaluate change in cervical alignment. Age, sex, body mass index (BMI), smoking history, preoperative C2-7 Cobb angle, T1 slope, C2-7 range of motion (C2-7 ROM), C2-7 sagittal vertical axis (C2-7 SVA), and cephalad vertebral level undergoing laminoplasty (CVLL) were assessed. Data were analyzed using Pearson and Spearman correlation test, and univariate and stepwise multivariate linear regression. T1 slope, C2-7 SVA, and CVLL significantly correlated with LCL (P < 0.001), whereas age, BMI, and preoperative C2-7 Cobb angle did not. In multiple linear regression analysis, higher T1 slope (B = 0.351, P = 0.037), greater C2-7 SVA (B = 0.393, P < 0.001), and starting laminoplasty at C4 level (B = - 7.038, P < 0.001) were significantly associated with higher postoperative LCL. Cervical alignment was compromised after laminoplasty in patients with CSM, and the degree of LCL was associated with preoperative T1 slope, C2-7 SVA, and CVLL.

Fever Is Associated with Reduced, Hypothermia with Increased Mortality in Septic Patients: A Meta-Analysis of Clinical Trials

PubMed Central

Rumbus, Zoltan; Matics, Robert; Hegyi, Peter; Zsiboras, Csaba; Szabo, Imre; Illes, Anita; Petervari, Erika; Balasko, Marta; Marta, Katalin; Miko, Alexandra; Parniczky, Andrea; Tenk, Judit; Rostas, Ildiko; Solymar, Margit

2017-01-01

Background Sepsis is usually accompanied by changes of body temperature (Tb), but whether fever and hypothermia predict mortality equally or differently is not fully clarified. We aimed to find an association between Tb and mortality in septic patients with meta-analysis of clinical trials. Methods We searched the PubMed, EMBASE, and Cochrane Controlled Trials Registry databases (from inception to February 2016). Human studies reporting Tb and mortality of patients with sepsis were included in the analyses. Average Tb with SEM and mortality rate of septic patient groups were extracted by two authors independently. Results Forty-two studies reported Tb and mortality ratios in septic patients (n = 10,834). Pearson correlation analysis revealed weak negative linear correlation (R2 = 0.2794) between Tb and mortality. With forest plot analysis, we found a 22.2% (CI, 19.2–25.5) mortality rate in septic patients with fever (Tb > 38.0°C), which was higher, 31.2% (CI, 25.7–37.3), in normothermic patients, and it was the highest, 47.3% (CI, 38.9–55.7), in hypothermic patients (Tb < 36.0°C). Meta-regression analysis showed strong negative linear correlation between Tb and mortality rate (regression coefficient: -0.4318; P < 0.001). Mean Tb of the patients was higher in the lowest mortality quartile than in the highest: 38.1°C (CI, 37.9–38.4) vs 37.1°C (CI, 36.7–37.4). Conclusions Deep Tb shows negative correlation with the clinical outcome in sepsis. Fever predicts lower, while hypothermia higher mortality rates compared with normal Tb. Septic patients with the lowest (< 25%) chance of mortality have higher Tb than those with the highest chance (> 75%). PMID:28081244

Fever Is Associated with Reduced, Hypothermia with Increased Mortality in Septic Patients: A Meta-Analysis of Clinical Trials.

PubMed

Rumbus, Zoltan; Matics, Robert; Hegyi, Peter; Zsiboras, Csaba; Szabo, Imre; Illes, Anita; Petervari, Erika; Balasko, Marta; Marta, Katalin; Miko, Alexandra; Parniczky, Andrea; Tenk, Judit; Rostas, Ildiko; Solymar, Margit; Garami, Andras

2017-01-01

Sepsis is usually accompanied by changes of body temperature (Tb), but whether fever and hypothermia predict mortality equally or differently is not fully clarified. We aimed to find an association between Tb and mortality in septic patients with meta-analysis of clinical trials. We searched the PubMed, EMBASE, and Cochrane Controlled Trials Registry databases (from inception to February 2016). Human studies reporting Tb and mortality of patients with sepsis were included in the analyses. Average Tb with SEM and mortality rate of septic patient groups were extracted by two authors independently. Forty-two studies reported Tb and mortality ratios in septic patients (n = 10,834). Pearson correlation analysis revealed weak negative linear correlation (R2 = 0.2794) between Tb and mortality. With forest plot analysis, we found a 22.2% (CI, 19.2-25.5) mortality rate in septic patients with fever (Tb > 38.0°C), which was higher, 31.2% (CI, 25.7-37.3), in normothermic patients, and it was the highest, 47.3% (CI, 38.9-55.7), in hypothermic patients (Tb < 36.0°C). Meta-regression analysis showed strong negative linear correlation between Tb and mortality rate (regression coefficient: -0.4318; P < 0.001). Mean Tb of the patients was higher in the lowest mortality quartile than in the highest: 38.1°C (CI, 37.9-38.4) vs 37.1°C (CI, 36.7-37.4). Deep Tb shows negative correlation with the clinical outcome in sepsis. Fever predicts lower, while hypothermia higher mortality rates compared with normal Tb. Septic patients with the lowest (< 25%) chance of mortality have higher Tb than those with the highest chance (> 75%).

A pilot study on bladder wall thickness at different filling stages

NASA Astrophysics Data System (ADS)

Zhang, Xi; Liu, Yang; Li, Baojuan; Zhang, Guopeng; Liang, Zhengrong; Lu, Hongbing

2015-03-01

The ever-growing death rate and the high recurrence of bladder cancer make the early detection and appropriate followup procedure of bladder cancer attract more attention. Compare to optical cystoscopy, image-based studies have revealed its potentials in non-invasive observations of the abnormities of bladder recently, in which MR imaging turns out to be a better choice for bladder evaluation due to its non-ionizing and high contrast between urine and wall tissue. Recent studies indicate that bladder wall thickness tends to be a good indicator for detecting bladder wall abnormalities. However, it is difficult to quantitatively compare wall thickness of the same subject at different filling stages or among different subjects. In order to explore thickness variations at different bladder filling stages, in this study, we preliminarily investigate the relationship between bladder wall thickness and bladder volume based on a MRI database composed of 40 datasets acquired from 10 subjects at different filling stages, using a pipeline for thickness measurement and analysis proposed in our previous work. The Student's t-test indicated that there was no significant different on wall thickness between the male group and the female group. The Pearson correlation analysis result indicated that negative correlation with a correlation coefficient of -0.8517 existed between the wall thickness and bladder volume, and the correlation was significant(p <0.01). The corresponding linear regression equation was then estimated by the unary linear regression. Compared to the absolute value of wall thickness, the z-score of wall thickness would be more appropriate to reflect the thickness variations. For possible abnormality detection of a bladder based on wall thickness, the intra-subject and inter-subject thickness variation should be considered.

What makes patients with fibromyalgia feel better? Correlations between Patient Global Impression of Improvement and changes in clinical symptoms and function: a pooled analysis of 4 randomized placebo-controlled trials of duloxetine.

PubMed

Hudson, James I; Arnold, Lesley M; Bradley, Laurence A; Choy, Ernest H S; Mease, Philip J; Wang, Fujun; Ahl, Jonna; Wohlreich, Madelaine M

2009-11-01

To investigate the relationship between changes in clinical rating scale items and endpoint Patient Global Impression of Improvement (PGI-I). Data were pooled from 4 randomized, double-blind, placebo-controlled studies of duloxetine in patients with fibromyalgia (FM). Variables included in the analyses were those that assessed symptoms in FM domains of pain, fatigue, sleep, cognitive difficulties, emotional well-being, physical function, and impact on daily living. The association of endpoint PGI-I with changes from baseline in individual variables was assessed using Pearson product-moment correlations (r). Stepwise linear regression was used to identify those variables for which changes from baseline were statistically significant independent predictors of the endpoint PGI-I ratings. Changes in pain variables and interference of symptoms with the ability to work were highly correlated (r >or= 0.5 or r

Short communication: Correlation between within-herd antibody-prevalence and bulk tank milk antibody levels to Mycobacterium avium ssp. paratuberculosis using 2 commercial immunoassays.

PubMed

Pesqueira, M N; Yus, E; Factor, C; Mato, I; Sanjuán, M L; Eiras, C; Arnaiz, I; Diéguez, F J

2017-09-01

The objective of this study was to determine the correlation between the results obtained with the ELISA technique for antibodies to Mycobacterium avium ssp. paratuberculosis in serum and bulk tank milk at the herd level. For this purpose, 203 samples of bulk tank milk were analyzed with 2 commercial ELISA from dairy herds with a prevalence of seropositive animals that was also determined. In regard to the reference test (results in blood serum), the sensitivity of the bulk tank milk test to detect high-positive herds (≥10% seroprevalence) ranged from 85.7 to 71.4%. The specificity to detect herds with no seropositive animals ranged from 70.5 to 53%. In a quantitative approach, Pearson correlation coefficients, reported as a measure of the linear association between herd seroprevalences and transformed optical density values recorded in bulk tank milk, were 0.39 and 0.54 for the studied ELISA. Although the test results were relatively fairly correlated with the within-herd prevalence, the practical utility of bulk tank milk testing for Mycobacterium avium ssp. paratuberculosis seems limited, especially regarding specificity. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Correlation between mean body mass index in the population and prevalence of obesity in Brazilian capitals: empirical evidence for a population-based approach of obesity.

PubMed

Lobato, Jackeline Christiane Pinto; Kale, Pauline Lorena; Velarde, Luis Guillermo Coca; Szklo, Moyses; Costa, Antonio José Leal

2015-04-02

The purpose of this study was to investigate the association between mean body mass index (BMI) and prevalence of obesity in adult populations living in Brazilian State capitals. An ecological study was conducted, using data from the National Household Budget Survey conducted in July 2002 through June 2003, including a representative sample of 48.470 households. Pearson's correlation and linear regression coefficients were estimated in order to define the relationships of mean BMI and sex-specific, age standardized obesity prevalence (BMI ≥ 30.0 kg/m(2)) in adults aged 20 to 59 years. Stronger correlations between BMI and prevalence of obesity were observed in women (r = 0.9; p < 0.001) than in men (r = 0.6; p = 0.001) in all analyzes. A reduction of one unit in mean BMI predicted a decline in the prevalence of obesity of about 4.0% (95% CI: 1.7-6.3) in men, and 3.4% (95% CI: 2.6-4.3) in women. We found a correlation between BMI and prevalence of obesity, particularly among women, suggesting that population-based strategies would be effective to reduce the prevalence of obesity in adult populations living in Brazilian state capitals.

Linking N2O emission from biochar-amended composting process to the abundance of denitrify (nirK and nosZ) bacteria community.

PubMed

Li, Shuqing; Song, Lina; Jin, Yaguo; Liu, Shuwei; Shen, Qirong; Zou, Jianwen

2016-12-01

Manure composting has been recognized as an important anthropogenic source of nitrous oxide (N2O) contributing to global warming. However, biochar effect on N2O emissions from manure composting is rarely evaluated, especially by linking it to abundance of denitrifying bacteria community. Results of this study indicated that biochar amendment significantly reduced N2O emissions from manure composting, primarily due to suppression of the nirK gene abundance of denitrifying bacteria. Pearson's correlation analysis showed a significant positive correlation between nirK abundance and N2O fluxes, while a negative correlation between nosZ density and N2O fluxes. Simultaneously, a linear correlation between nirK gene abundance minus nosZ gene abundance with N2O fluxes was also observed. In addition, a statistical model for estimating N2O emissions based on the bacterial denitrifying functional genes was developed and verified to adequately fit the observed emissions. Our results highlighted that biochar amendment would be an alternative strategy for mitigating N2O emissions during manure composting, and the information of related functional bacterial communities could be helpful for understanding the mechanism of N2O emissions.

Preliminary Survey on TRY Forest Traits and Growth Index Relations - New Challenges

NASA Astrophysics Data System (ADS)

Lyubenova, Mariyana; Kattge, Jens; van Bodegom, Peter; Chikalanov, Alexandre; Popova, Silvia; Zlateva, Plamena; Peteva, Simona

2016-04-01

Forest ecosystems provide critical ecosystem goods and services, including food, fodder, water, shelter, nutrient cycling, and cultural and recreational value. Forests also store carbon, provide habitat for a wide range of species and help alleviate land degradation and desertification. Thus they have a potentially significant role to play in climate change adaptation planning through maintaining ecosystem services and providing livelihood options. Therefore the study of forest traits is such an important issue not just for individual countries but for the planet as a whole. We need to know what functional relations between forest traits exactly can express TRY data base and haw it will be significant for the global modeling and IPBES. The study of the biodiversity characteristics at all levels and functional links between them is extremely important for the selection of key indicators for assessing biodiversity and ecosystem services for sustainable natural capital control. By comparing the available information in tree data bases: TRY, ITR (International Tree Ring) and SP-PAM the 42 tree species are selected for the traits analyses. The dependence between location characteristics (latitude, longitude, altitude, annual precipitation, annual temperature and soil type) and forest traits (specific leaf area, leaf weight ratio, wood density and growth index) is studied by by multiply regression analyses (RDA) using the statistical software package Canoco 4.5. The Pearson correlation coefficient (measure of linear correlation), Kendal rank correlation coefficient (non parametric measure of statistical dependence) and Spearman correlation coefficient (monotonic function relationship between two variables) are calculated for each pair of variables (indexes) and species. After analysis of above mentioned correlation coefficients the dimensional linear regression models, multidimensional linear and nonlinear regression models and multidimensional neural networks models are built. The strongest dependence between It and WD was obtained. The research will support the work on: Strategic Plan for Biodiversity 2011-2020, modelling and implementation of ecosystem-based approaches to climate change adaptation and disaster risk reduction. Key words: Specific leaf area (SLA), Leaf weight ratio (LWR), Wood density (WD), Growth index (It)

Meta-Analytic Structural Equation Modeling: A Two-Stage Approach

ERIC Educational Resources Information Center

Cheung, Mike W. L.; Chan, Wai

2005-01-01

To synthesize studies that use structural equation modeling (SEM), researchers usually use Pearson correlations (univariate r), Fisher z scores (univariate z), or generalized least squares (GLS) to combine the correlation matrices. The pooled correlation matrix is then analyzed by the use of SEM. Questionable inferences may occur for these ad hoc…

The Robustness of LISREL Estimates in Structural Equation Models with Categorical Variables.

ERIC Educational Resources Information Center

Ethington, Corinna A.

This study examined the effect of type of correlation matrix on the robustness of LISREL maximum likelihood and unweighted least squares structural parameter estimates for models with categorical manifest variables. Two types of correlation matrices were analyzed; one containing Pearson product-moment correlations and one containing tetrachoric,…

Relevant reduction effect with a modified thermoplastic mask of rotational error for glottic cancer in IMRT

NASA Astrophysics Data System (ADS)

Jung, Jae Hong; Jung, Joo-Young; Cho, Kwang Hwan; Ryu, Mi Ryeong; Bae, Sun Hyun; Moon, Seong Kwon; Kim, Yong Ho; Choe, Bo-Young; Suh, Tae Suk

2017-02-01

The purpose of this study was to analyze the glottis rotational error (GRE) by using a thermoplastic mask for patients with the glottic cancer undergoing intensity-modulated radiation therapy (IMRT). We selected 20 patients with glottic cancer who had received IMRT by using the tomotherapy. The image modalities with both kilovoltage computed tomography (planning kVCT) and megavoltage CT (daily MVCT) images were used for evaluating the error. Six anatomical landmarks in the image were defined to evaluate a correlation between the absolute GRE (°) and the length of contact with the underlying skin of the patient by the mask (mask, mm). We also statistically analyzed the results by using the Pearson's correlation coefficient and a linear regression analysis ( P <0.05). The mask and the absolute GRE were verified to have a statistical correlation ( P < 0.01). We found a statistical significance for each parameter in the linear regression analysis (mask versus absolute roll: P = 0.004 [ P < 0.05]; mask versus 3D-error: P = 0.000 [ P < 0.05]). The range of the 3D-errors with contact by the mask was from 1.2% - 39.7% between the maximumand no-contact case in this study. A thermoplastic mask with a tight, increased contact area may possibly contribute to the uncertainty of the reproducibility as a variation of the absolute GRE. Thus, we suggest that a modified mask, such as one that covers only the glottis area, can significantly reduce the patients' setup errors during the treatment.

Temperament affects sympathetic nervous function in a normal population.

PubMed

Kim, Bora; Lee, Jae-Hon; Kang, Eun-Ho; Yu, Bum-Hee

2012-09-01

Although specific temperaments have been known to be related to autonomic nervous function in some psychiatric disorders, there are few studies that have examined the relationship between temperaments and autonomic nervous function in a normal population. In this study, we examined the effect of temperament on the sympathetic nervous function in a normal population. Sixty eight healthy subjects participated in the present study. Temperament was assessed using the Korean version of the Cloninger Temperament and Character Inventory (TCI). Autonomic nervous function was determined by measuring skin temperature in a resting state, which was recorded for 5 minutes from the palmar surface of the left 5th digit using a thermistor secured with a Velcro® band. Pearson's correlation analysis and multiple linear regression were used to examine the relationship between temperament and skin temperature. A higher harm avoidance score was correlated with a lower skin temperature (i.e. an increased sympathetic tone; r=-0.343, p=0.004) whereas a higher persistence score was correlated with a higher skin temperature (r=0.433, p=0.001). Hierarchical linear regression analysis revealed that harm avoidance was able to predict the variance of skin temperature independently, with a variance of 7.1% after controlling for sex, blood pressure and state anxiety and persistence was the factor predicting the variance of skin temperature with a variance of 5.0%. These results suggest that high harm avoidance is related to an increased sympathetic nervous function whereas high persistence is related to decreased sympathetic nervous function in a normal population.

Predictors of caregiver burden in Iranian family caregivers of cancer patients.

PubMed

Mirsoleymani, Seyed Reza; Rohani, Camelia; Matbouei, Mahsa; Nasiri, Malihe; Vasli, Parvaneh

2017-01-01

Caregiver burden threatens the psychological, emotional, functional and even physical health of caregivers. The aims of this study were to determine caregiver burden and family distress and the relationship between them, also to explore predictors of caregiver burden in a sample of Iranian family caregivers of cancer patients. This is a cross-sectional study with correlational design. A total of 104 family caregivers of cancer patients were asked to respond to the Caregiver Burden Inventory (CBI) and the Family Distress Index (FDI) together with a sociodemographic questionnaire. For evaluating the relationship between CBI and FDI scores, the Pearson's product-moment correlation was used. In addition, multiple linear regression analysis was applied to explore the predictive factors of caregiver burden. A high burden was experienced by almost half of the caregivers (48.1%). The FDI mean score was 9.76 ± 5.40 ranged from 0 to 24. A strong positive correlation was found between the caregiver burden and family distress ( r = 0.76). Multiple linear regression results showed the predictive role of FDI score (β = 0.71, P = 0.001), patient's gender (β = -0.25, P = 0.001), and early cancer diagnosis (β =0.13, P = 0.027) in caregiver burden. They could explain 65% of variance in the level of burden in family caregivers. Family nurses should consider the caregivers burden and vulnerability of families with cancer patient, especially if the patient is a male or has a new diagnosis. They should also design special programs for the whole family as a system that family can adapt to the new situation.

Temperament Affects Sympathetic Nervous Function in a Normal Population

PubMed Central

Kim, Bora; Lee, Jae-Hon; Kang, Eun-Ho

2012-01-01

Objective Although specific temperaments have been known to be related to autonomic nervous function in some psychiatric disorders, there are few studies that have examined the relationship between temperaments and autonomic nervous function in a normal population. In this study, we examined the effect of temperament on the sympathetic nervous function in a normal population. Methods Sixty eight healthy subjects participated in the present study. Temperament was assessed using the Korean version of the Cloninger Temperament and Character Inventory (TCI). Autonomic nervous function was determined by measuring skin temperature in a resting state, which was recorded for 5 minutes from the palmar surface of the left 5th digit using a thermistor secured with a Velcro® band. Pearson's correlation analysis and multiple linear regression were used to examine the relationship between temperament and skin temperature. Results A higher harm avoidance score was correlated with a lower skin temperature (i.e. an increased sympathetic tone; r=-0.343, p=0.004) whereas a higher persistence score was correlated with a higher skin temperature (r=0.433, p=0.001). Hierarchical linear regression analysis revealed that harm avoidance was able to predict the variance of skin temperature independently, with a variance of 7.1% after controlling for sex, blood pressure and state anxiety and persistence was the factor predicting the variance of skin temperature with a variance of 5.0%. Conclusion These results suggest that high harm avoidance is related to an increased sympathetic nervous function whereas high persistence is related to decreased sympathetic nervous function in a normal population. PMID:22993530

Impact of income and income inequality on infant health outcomes in the United States.

PubMed

Olson, Maren E; Diekema, Douglas; Elliott, Barbara A; Renier, Colleen M

2010-12-01

The goal was to investigate the relationships of income and income inequality with neonatal and infant health outcomes in the United States. The 2000-2004 state data were extracted from the Kids Count Data Center. Health indicators included proportion of preterm births (PTBs), proportion of infants with low birth weight (LBW), proportion of infants with very low birth weight (VLBW), and infant mortality rate (IMR). Income was evaluated on the basis of median family income and proportion of federal poverty levels; income inequality was measured by using the Gini coefficient. Pearson correlations evaluated associations between the proportion of children living in poverty and the health indicators. Linear regression evaluated predictive relationships between median household income, proportion of children living in poverty, and income inequality for the 4 health indicators. Median family income was negatively correlated with all birth outcomes (PTB, r = -0.481; LBW, r = -0.295; VLBW, r = -0.133; IMR, r = -0.432), and the Gini coefficient was positively correlated (PTB, r = 0.339; LBW, r = 0.398; VLBW, r = 0.460; IMR, r = 0.114). The Gini coefficient explained a significant proportion of the variance in rate for each outcome in linear regression models with median family income. Among children living in poverty, the role of income decreased as the degree of poverty decreased, whereas the role of income inequality increased. Both income and income inequality affect infant health outcomes in the United States. The health of the poorest infants was affected more by absolute wealth than relative wealth.

Estimation of stature from sternum - Exploring the quadratic models.

PubMed

Saraf, Ashish; Kanchan, Tanuj; Krishan, Kewal; Ateriya, Navneet; Setia, Puneet

2018-04-14

Identification of the dead is significant in examination of unknown, decomposed and mutilated human remains. Establishing the biological profile is the central issue in such a scenario, and stature estimation remains one of the important criteria in this regard. The present study was undertaken to estimate stature from different parts of the sternum. A sample of 100 sterna was obtained from individuals during the medicolegal autopsies. Length of the deceased and various measurements of the sternum were measured. Student's t-test was performed to find the sex differences in stature and sternal measurements included in the study. Correlation between stature and sternal measurements were analysed using Karl Pearson's correlation, and linear and quadratic regression models were derived. All the measurements were found to be significantly larger in males than females. Stature correlated best with the combined length of sternum, among males (R = 0.894), females (R = 0.859), and for the total sample (R = 0.891). The study showed that the models derived for stature estimation from combined length of sternum are likely to give the most accurate estimates of stature in forensic case work when compared to manubrium and mesosternum. Accuracy of stature estimation further increased with quadratic models derived for the mesosternum among males and combined length of sternum among males and females when compared to linear regression models. Future studies in different geographical locations and a larger sample size are proposed to confirm the study observations. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Nurse staffing levels and outcomes - mining the UK national data sets for insight.

PubMed

Leary, Alison; Tomai, Barbara; Swift, Adrian; Woodward, Andrew; Hurst, Keith

2017-04-18

Purpose Despite the generation of mass data by the nursing workforce, determining the impact of the contribution to patient safety remains challenging. Several cross-sectional studies have indicated a relationship between staffing and safety. The purpose of this paper is to uncover possible associations and explore if a deeper understanding of relationships between staffing and other factors such as safety could be revealed within routinely collected national data sets. Design/methodology/approach Two longitudinal routinely collected data sets consisting of 30 years of UK nurse staffing data and seven years of National Health Service (NHS) benchmark data such as survey results, safety and other indicators were used. A correlation matrix was built and a linear correlation operation was applied (Pearson product-moment correlation coefficient). Findings A number of associations were revealed within both the UK staffing data set and the NHS benchmarking data set. However, the challenges of using these data sets soon became apparent. Practical implications Staff time and effort are required to collect these data. The limitations of these data sets include inconsistent data collection and quality. The mode of data collection and the itemset collected should be reviewed to generate a data set with robust clinical application. Originality/value This paper revealed that relationships are likely to be complex and non-linear; however, the main contribution of the paper is the identification of the limitations of routinely collected data. Much time and effort is expended in collecting this data; however, its validity, usefulness and method of routine national data collection appear to require re-examination.

Three-dimensional gender differences in facial form of children in the North East of England.

PubMed

Bugaighis, Iman; Mattick, Clare R; Tiddeman, Bernard; Hobson, Ross

2013-06-01

The aim of the prospective cross-sectional morphometric study was to explore three dimensional (3D) facial shape and form (shape plus size) variation within and between 8- and 12-year-old Caucasian children; 39 males age-matched with 41 females. The 3D images were captured using a stereophotogrammeteric system, and facial form was recorded by digitizing 39 anthropometric landmarks for each scan. The x, y, z coordinates of each landmark were extracted and used to calculate linear and angular measurements. 3D landmark asymmetry was quantified using Generalized Procrustes Analysis (GPA) and an average face was constructed for each gender. The average faces were superimposed and differences were visualized and quantified. Shape variations were explored using GPA and PrincipalComponent Analysis. Analysis of covariance and Pearson correlation coefficients were used to explore gender differences and to determine any correlation between facial measurements and height or weight. Multivariate analysis was used to ascertain differences in facial measurements or 3D landmark asymmetry. There were no differences in height or weight between genders. There was a significant positive correlation between facial measurements and height and weight and statistically significant differences in linear facial width measurements between genders. These differences were related to the larger size of males rather than differences in shape. There were no age- or gender-linked significant differences in 3D landmark asymmetry. Shape analysis confirmed similarities between both males and females for facial shape and form in 8- to 12-year-old children. Any differences found were related to differences in facial size rather than shape.

Association of academic performance of premedical students to satisfaction and engagement in a short training program: a cross sectional study presenting gender differences

PubMed Central

2014-01-01

Background It is important that students have a high academic engagement and satisfaction in order to have good academic achievement. No study measures association of these elements in a short training program. This study aimed to measure the correlation between academic achievement, satisfaction and engagement dimensions in a short training program among premedical students. Methods We carried out a cross sectional study, in August 2013, at Cercle d’Etudiants, Ingénieurs, Médecins et Professeurs de Lycée pour le Triomphe de l’Excellence (CEMPLEX) training center, a center which prepares students for the national common entrance examination into medical schools in Cameroon. We included all students attending this training center during last examination period. They were asked to fill out a questionnaire on paper. Academic engagement was measured using three dimensions: vigor, dedication and absorption. Satisfaction to lessons, for each learning subject was collected. Academic achievement was calculated using mean of the score of all learning subjects affected with their coefficient. Pearson coefficient (r) and multiple regression models were used to measure association. A p value < 0.05 was statistically significant. Results In total, 180 students were analyzed. In univariate linear analysis, we found correlation with academic achievement for vigor (r = 0.338, p = 0.006) and dedication (r = 0.287, p = 0.021) only in male students. In multiple regression linear analysis, academic engagement and satisfaction were correlated to academic achievement only in male students (R2 = 0.159, p = 0.035). No correlation was found in female students and in all students. The independent variables (vigor, dedication, absorption and satisfaction) explained 6.8-24.3% of the variance of academic achievement. Conclusion It is only in male students that academic engagement and satisfaction to lessons are correlated to academic achievement in this short training program for premedical students and this correlation is weak. PMID:24564911

Association of academic performance of premedical students to satisfaction and engagement in a short training program: a cross sectional study presenting gender differences.

PubMed

Bigna, Jean Joel R; Fonkoue, Loic; Tchatcho, Manuela Francette F; Dongmo, Christelle N; Soh, Dorothée M; Um, Joseph Lin Lewis N; Sime, Paule Sandra D; Affana, Landry A; Woum, Albert Ruben N; Noumegni, Steve Raoul N; Tabekou, Alphonce; Wanke, Arlette M; Taffe, Herman Rhais K; Tchoukouan, Miriette Linda N; Anyope, Kevin O; Ella, Stephane Brice E; Mouaha, Berny Vanessa T; Kenne, Edgar Y; Mbessoh, Ulrich Igor K; Tchapmi, Adrienne Y; Tene, Donald F; Voufouo, Steve S; Zogo, Stephanie M; Nouebissi, Linda P; Satcho, Kevine F; Tchoumo, Wati Joel T; Basso, Moise Fabrice; Tcheutchoua, Bertrand Daryl N; Agbor, Ako A

2014-02-24

It is important that students have a high academic engagement and satisfaction in order to have good academic achievement. No study measures association of these elements in a short training program. This study aimed to measure the correlation between academic achievement, satisfaction and engagement dimensions in a short training program among premedical students. We carried out a cross sectional study, in August 2013, at Cercle d'Etudiants, Ingénieurs, Médecins et Professeurs de Lycée pour le Triomphe de l'Excellence (CEMPLEX) training center, a center which prepares students for the national common entrance examination into medical schools in Cameroon. We included all students attending this training center during last examination period. They were asked to fill out a questionnaire on paper. Academic engagement was measured using three dimensions: vigor, dedication and absorption. Satisfaction to lessons, for each learning subject was collected. Academic achievement was calculated using mean of the score of all learning subjects affected with their coefficient. Pearson coefficient (r) and multiple regression models were used to measure association. A p value < 0.05 was statistically significant. In total, 180 students were analyzed. In univariate linear analysis, we found correlation with academic achievement for vigor (r = 0.338, p = 0.006) and dedication (r = 0.287, p = 0.021) only in male students. In multiple regression linear analysis, academic engagement and satisfaction were correlated to academic achievement only in male students (R2 = 0.159, p = 0.035). No correlation was found in female students and in all students. The independent variables (vigor, dedication, absorption and satisfaction) explained 6.8-24.3% of the variance of academic achievement. It is only in male students that academic engagement and satisfaction to lessons are correlated to academic achievement in this short training program for premedical students and this correlation is weak.

The Placebo Effect in Clinical Trials for Alcohol Dependence: An Exploratory Analysis of 51 Naltrexone and Acamprosate Studies

PubMed Central

Litten, Raye Z.; Castle, I-Jen P.; Falk, Daniel; Ryan, Megan; Fertig, Joanne; Chen, Chiung M.; Yi, Hsiao-ye

2013-01-01

Background The placebo effect often undermines efforts to determine treatment effectiveness in clinical trials. A significant placebo response occurs in alcohol trials, but it is not well understood. The purpose of this study was to characterize the placebo response across multiple naltrexone and acamprosate studies. Methods Fifty-one trials, 3 with a naltrexone and an acamprosate arm, 31 with at least 1 naltrexone arm, and 17 with at least 1 acamprosate arm, were identified from Cochrane reviews and PubMed search. To be included in this study, patients had to be at least 18 years old, abstinent from alcohol before randomization, and meet a diagnosis of alcohol dependence. Pearson correlation coefficients (rp) and simple linear regression were used to describe the strength of linear relationships between placebo response and treatment effect size. Spearman’s rank correlation coefficients (rs) were used to examine the strength of associations between study characteristics and placebo response. Results For the end-point measures of percent days abstinent and total abstinence, a negative relationship was evident between placebo response and treatment effect size in the naltrexone trials (rp = −0.55, p < 0.01 and rp = −0.20, p = 0.35, respectively) as well as in the acamprosate trials (rp = −0.45, p = 0.09 and rp = −0.56, p = 0.01, respectively). The placebo response for percent days abstinent was negatively correlated with mean age of participants (rs = −0.42, p = 0.05) across naltrexone trials and positively correlated with publication year (rs = 0.57, p = 0.03) across acamprosate trials. However, these two study characteristics were not significantly correlated with treatment effect size. Conclusion The placebo response varied considerably across trials and was negatively correlated with the treatment effect size. Additional studies are required to fully understand the complex nature of the placebo response and to evaluate approaches to minimize its effects. PMID:23889231

Validity and reliability of Turkish translation of Migraine Disability Assessment (MIDAS) questionnaire in patients with migraine.

PubMed

Gedikoglu, U; Coskun, O; Inan, L E; Ucler, S; Tunc, T; Emre, U

2005-06-01

The Migraine Disability Assessment (MIDAS) questionnaire is a brief, self-administered questionnaire which is designed to quantify headache-related disability in a 3-month period. We have tested a Turkish version of the MIDAS questionnaire in 60 migraine patients. Sixty of the clinically diagnosed migraine headache sufferers were enrolled in a 90-day diary study and completed the MIDAS questionnaire in the first, 21st and the last day of the 90-day study. The scores taken from the diary and the scores of the MIDAS taken at different times were evaluated by the correlation tests of both Pearson and Spearman for each question and total scores. Cronbach's scores taken from the diary and taken from the test of the MIDAS which was applied at different times were evaluated. Pearson's correlation on the responses in the initial MIDAS questions was between 0.44 (reduced productivity in household chores) and 0.78 (missed work or school days). The correlation of the Spearman was similar to the Pearson values. As a result, we found that the overall score of the MIDAS has a good reliability and its internal consistency is also good (Cronbach's alpha 0.87). These findings support the use of the MIDAS questionnaire as a clinical and research tool on Turkish patients.

A Study on Work Ability Index and Physical Work Capacity on the Base of Fax Equation VO(2) Max in Male Nursing Hospital Staff in Isfahan, Iran.

PubMed

Habibi, Ehsanollah; Dehghan, Habibollah; Zeinodini, Mohhamad; Yousefi, Hosseinali; Hasanzadeh, Akbar

2012-11-01

The purpose of this research is to establish the ability of employees by work ability index (WAI), physical work capacity (PWC), and finding the correlation between them. Establishing the PWC index with attention to WAI values for the purpose of saving in costs and time of PWC measurements is another aim of this project. The present research is an analytic cross-sectional and one-trail study. The study population consists of 228 randomly selected registered nurses from hospitals in Isfahan (Iran). The WAI and PWC were established through WAI questionnaire and Fax equation and by using ergometer bicycle, respectively. The resulting data were analyzed using SPSS 16 software. Average WAI and PWC among the study population were 38.25±4.4 and 4.45±0.7, respectively. Pearson test results showed no significant correlation between PWC and WAI in different age groups (r=0.3 and P>0.05). Multiple linear regression analysis showed that the variables of age and diagnosed diseases were the most effective factors of WAI (β=0.18 and P>0.05). Pearson test revealed a significant correlation between the number of diagnosed diseases and PWC index in age groups of 40-49 years. Average WAI in this research, like other studies on similar jobs is in the acceptable level of >36. Work ability index and PWC index in different age groups did not show a significant correlation and this suggests that there are essential discrepancies in work ability evaluations made by each index and it is not possible to predict PWC index using WAI values. Given the PWC results and the level of nursing staff's activity (low, medium) the WAI is a suitable instrument to establish the professionals' abilities. This study revealed that 27.6% of individuals were subject to medium-low work ability risk (WAI<37), which was 1.8 times that of Finland's professional health Institute, which could be caused by shift working and increased working hours.

The development and validation of using inertial sensors to monitor postural change in resistance exercise.

PubMed

Gleadhill, Sam; Lee, James Bruce; James, Daniel

2016-05-03

This research presented and validated a method of assessing postural changes during resistance exercise using inertial sensors. A simple lifting task was broken down to a series of well-defined tasks, which could be examined and measured in a controlled environment. The purpose of this research was to determine whether timing measures obtained from inertial sensor accelerometer outputs are able to provide accurate, quantifiable information of resistance exercise movement patterns. The aim was to complete a timing measure validation of inertial sensor outputs. Eleven participants completed five repetitions of 15 different deadlift variations. Participants were monitored with inertial sensors and an infrared three dimensional motion capture system. Validation was undertaken using a Will Hopkins Typical Error of the Estimate, with a Pearson׳s correlation and a Bland Altman Limits of Agreement analysis. Statistical validation measured the timing agreement during deadlifts, from inertial sensor outputs and the motion capture system. Timing validation results demonstrated a Pearson׳s correlation of 0.9997, with trivial standardised error (0.026) and standardised bias (0.002). Inertial sensors can now be used in practical settings with as much confidence as motion capture systems, for accelerometer timing measurements of resistance exercise. This research provides foundations for inertial sensors to be applied for qualitative activity recognition of resistance exercise and safe lifting practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

[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.

Assessment of oxygen saturation in dental pulp of permanent teeth with periodontal disease.

PubMed

Giovanella, Larissa Bergesch; Barletta, Fernando Branco; Felippe, Wilson Tadeu; Bruno, Kely Firmino; de Alencar, Ana Helena Gonçalves; Estrela, Carlos

2014-12-01

In individuals with periodontal disease, dental pulp status should be determined before a treatment plan is made. Pulse oximeters are promising diagnostic tools to evaluate pulp vascularization. This study used pulse oximetry to determine the level of oxygen saturation in dental pulp of intact permanent teeth with periodontal attachment loss (PAL) and gingival recession (GR) and to evaluate the correlation between periodontal disease and level of oxygen saturation in the pulp. This study included 67 anterior teeth of 35 patients; all teeth showed intact crowns, PAL, a periodontal pocket (PP), and GR. The teeth underwent periodontal examination, cold and electric pulp testing, and pulse oximetry measurements. The Pearson correlation coefficient and a linear regression coefficient were calculated to evaluate the degree of correlation between periodontal disease markers (PAL, PP, and GR) and the level of oxygen saturation in dental pulp. These tests also evaluated possible associations between oxygen saturation and cold and electric pulp testing. PAL, PP, and GR had negative correlations with oxygen saturation in dental pulp. Conversely, no statistically significant association was found between oxygen saturation in dental pulp and the response to electric sensibility testing. Oxygen saturation was lower in the pulp of permanent teeth with PAL, PP, and GR, indicating that periodontal disease correlates with the level of oxygen saturation in the pulp. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Decreased platelet APP isoform ratios in autosomal dominant Alzheimer's disease: baseline data from a DIAN cohort subset.

PubMed

Chatterjee, Pratishtha; Gupta, Veer B; Fagan, Anne M; Jasielec, Mateusz S; Xiong, Chengjie; Sohrabi, Hamid R; Dhaliwal, Satvinder; Taddei, Kevin; Bourgeat, Pierrick; Brown, Belinda M; Benzinger, Tammie; Bateman, Randall J; Morris, John C; Martins, Ralph N

2015-01-01

This study examines platelet amyloid precursor protein (APP) isoform ratios of 120KDa to 110KDa (APPr) between mutation carriers (MC) carrying a mutation for autosomal dominant Alzheimer's disease (ADAD) and non-carriers (NC). Two previous studies reported no significant difference in APPr between ADAD MC and NC, which may have been due to the small sample size in both studies. The current study examines APPr in MC versus NC in a larger sample. In addition, it investigated whether APPr correlate with neuroimaging data, neuropsychological data and cerebrospinal fluid biomarkers in a cohort subset derived from the Dominantly Inherited Alzheimer Network (DIAN) study. APPr were quantified by western blotting. Fifteen MC (symptomatic and asymptomatic) were compared against twelve NC using univariate general linear model. All participants underwent neuroimaging and neuropsychological testing which were correlated with APPr using Pearson's correlation coefficient (r). APPr were lower in MC compared to NC (p=0.003) while Mini-Mental State Examination (MMSE) scores were not significantly different (p>0.1). Furthermore, APPr inversely correlated with amyloid imaging in the Caudate Nucleus (r=-0.505; p<0.05) and Precuneus (r=-0.510; p<0.05). APPr are lower in ADAD MC compared to NC, and inversely correlated with brain amyloid load prior to significant differences in cognitive health. However, the use of APPr as a biomarker needs to be explored further.

Interplay between binding affinity and kinetics in protein-protein interactions.

PubMed

Cao, Huaiqing; Huang, Yongqi; Liu, Zhirong

2016-07-01

To clarify the interplay between the binding affinity and kinetics of protein-protein interactions, and the possible role of intrinsically disordered proteins in such interactions, molecular simulations were carried out on 20 protein complexes. With bias potential and reweighting techniques, the free energy profiles were obtained under physiological affinities, which showed that the bound-state valley is deep with a barrier height of 12 - 33 RT. From the dependence of the affinity on interface interactions, the entropic contribution to the binding affinity is approximated to be proportional to the interface area. The extracted dissociation rates based on the Arrhenius law correlate reasonably well with the experimental values (Pearson correlation coefficient R = 0.79). For each protein complex, a linear free energy relationship between binding affinity and the dissociation rate was confirmed, but the distribution of the slopes for intrinsically disordered proteins showed no essential difference with that observed for ordered proteins. A comparison with protein folding was also performed. Proteins 2016; 84:920-933. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Nanometer-scale displacement sensing using self-mixing interferometry with a correlation-based signal processing technique

NASA Astrophysics Data System (ADS)

Hast, J.; Okkonen, M.; Heikkinen, H.; Krehut, L.; Myllylä, R.

2006-06-01

A self-mixing interferometer is proposed to measure nanometre-scale optical path length changes in the interferometer's external cavity. As light source, the developed technique uses a blue emitting GaN laser diode. An external reflector, a silicon mirror, driven by a piezo nanopositioner is used to produce an interference signal which is detected with the monitor photodiode of the laser diode. Changing the optical path length of the external cavity introduces a phase difference to the interference signal. This phase difference is detected using a signal processing algorithm based on Pearson's correlation coefficient and cubic spline interpolation techniques. The results show that the average deviation between the measured and actual displacements of the silicon mirror is 3.1 nm in the 0-110 nm displacement range. Moreover, the measured displacements follow linearly the actual displacement of the silicon mirror. Finally, the paper considers the effects produced by the temperature and current stability of the laser diode as well as dispersion effects in the external cavity of the interferometer. These reduce the sensor's measurement accuracy especially in long-term measurements.

Are there any differences in power performance and morphological characteristics of Croatian adolescent soccer players according to the team position?

PubMed

Sporis, Goran; Vucetić, Vlatko; Jovanović, Mario; Milanović, Zoran; Rucević, Marijan; Vuleta, Dinko

2011-12-01

The aim of the study was to analyze differences in power performance and morphological characteristics of young Croatian soccer players with respect to their team positions and to establish correlations between the power performance variables. Anthropometric characteristics and jumping and sprint performances were analyzed for 45 soccer players (age 14-15; mean body height 175.4 +/- 6.61 cm; body weight 63.6 +/- 8.06 kg) according to their team positions (defender, midfielder, forward). Pearsons coefficient of correlation was used to determine the relationship between the power performance variables. There were no significant differences (p > 0.05) in the power performance of players according to their team position. The only significant differences between players were in some of the anthropometric characteristics, such as height and weight linear relationship was determined between almost all the power performance variables. Since the players in this study were very young and their sports careers have not reached their peak performance, it is possible that their nominal team positions may change during their soccer careers.

Syndromic surveillance models using Web data: the case of scarlet fever in the UK.

PubMed

Samaras, Loukas; García-Barriocanal, Elena; Sicilia, Miguel-Angel

2012-03-01

Recent research has shown the potential of Web queries as a source for syndromic surveillance, and existing studies show that these queries can be used as a basis for estimation and prediction of the development of a syndromic disease, such as influenza, using log linear (logit) statistical models. Two alternative models are applied to the relationship between cases and Web queries in this paper. We examine the applicability of using statistical methods to relate search engine queries with scarlet fever cases in the UK, taking advantage of tools to acquire the appropriate data from Google, and using an alternative statistical method based on gamma distributions. The results show that using logit models, the Pearson correlation factor between Web queries and the data obtained from the official agencies must be over 0.90, otherwise the prediction of the peak and the spread of the distributions gives significant deviations. In this paper, we describe the gamma distribution model and show that we can obtain better results in all cases using gamma transformations, and especially in those with a smaller correlation factor.

One device, one equation: the simplest way to objectively evaluate psoriasis severity.

PubMed

Choi, Jae Woo; Kim, Bo Ri; Choi, Chong Won; Youn, Sang Woong

2015-02-01

The erythema, scale and thickness of psoriasis lesions could be converted to bioengineering parameters. An objective psoriasis severity assessment is advantageous in terms of accuracy and reproducibility over conventional severity assessment. We aimed to formulate an objective psoriasis severity index with a single bioengineering device that can possibly substitute the conventional subjective Psoriasis Severity Index. A linear regression analysis was performed to derive the formula with the subjective Psoriasis Severity Index as the dependent variable and various bioengineering parameters determined from 157 psoriasis lesions as independent variables. The construct validity of the objective Psoriasis Severity Index was evaluated with an additional 30 psoriasis lesions through a Pearson correlation analysis. The formula is composed of hue and brightness, which are sufficiently obtainable with a Colorimeter alone. A very strong positive correlation was found between the objective and subjective psoriasis severity indexes. The objective Psoriasis Severity Index is a novel, practical and valid assessment method that can substitute the conventional one. Combined with subjective area assessment, it could further replace the Psoriasis Area and Severity Index which is currently most popular. © 2014 Japanese Dermatological Association.

Application of multivariate analysis to investigate the trace element contamination in top soil of coal mining district in Jorong, South Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Pujiwati, Arie; Nakamura, K.; Watanabe, N.; Komai, T.

2018-02-01

Multivariate analysis is applied to investigate geochemistry of several trace elements in top soils and their relation with the contamination source as the influence of coal mines in Jorong, South Kalimantan. Total concentration of Cd, V, Co, Ni, Cr, Zn, As, Pb, Sb, Cu and Ba was determined in 20 soil samples by the bulk analysis. Pearson correlation is applied to specify the linear correlation among the elements. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to observe the classification of trace elements and contamination sources. The results suggest that contamination loading is contributed by Cr, Cu, Ni, Zn, As, and Pb. The elemental loading mostly affects the non-coal mining area, for instances the area near settlement and agricultural land use. Moreover, the contamination source is classified into the areas that are influenced by the coal mining activity, the agricultural types, and the river mixing zone. Multivariate analysis could elucidate the elemental loading and the contamination sources of trace elements in the vicinity of coal mine area.

Investigation of the wavelength dependence of laser stratigraphy on Cu and Ni coatings using LIBS compared to a pure thermal ablation model

NASA Astrophysics Data System (ADS)

Paulis, Evgeniya; Pacher, Ulrich; Weimerskirch, Morris J. J.; Nagy, Tristan O.; Kautek, Wolfgang

2017-12-01

In this study, galvanic coatings of Cu and Ni, typically applied in industrial standard routines, were investigated. Ablation experiments were carried out using the first two harmonic wavelengths of a pulsed Nd:YAG laser and the resulting plasma spectra were analysed using a linear Pearson correlation method. For both wavelengths the absorption/ablation behaviour as well as laser-induced breakdown spectroscopy (LIBS) depth profiles were studied varying laser fluences between 4.3-17.2 J/cm^2 at 532 nm and 2.9-11.7 J/cm^2 at 1064 nm. The LIBS-stratigrams were compared with energy-dispersive X-ray spectroscopy of cross-sections. The ablation rates were calculated and compared to theoretical values originating from a thermal ablation model. Generally, higher ablation rates were obtained with 532 nm light for both materials. The light-plasma interaction is suggested as possible cause of the lower ablation rates in the infrared regime. Neither clear evidence of the pure thermal ablation, nor correlation with optical properties of investigated materials was obtained.

Determinants of the Transmission Variation of Hand, Foot and Mouth Disease in China.

PubMed

Zhao, Jijun; Li, Xinmin

2016-01-01

Severe outbreaks of hand, foot and mouth disease (HFMD) have occurred in China for decades. Our understanding of the HFMD transmission process and its determinants is still limited. In this paper, factors that affect the local variation of HFMD transmission process were studied. Three classes of factors, including meteorological, demographic and public health intervention factors, were carefully selected and their effects on HFMD transmission were investigated with Pearson's correlation coefficient and multiple linear regression models. The determining factors for the variation of HFMD transmission were different for the southeastern and the northwestern regions of China. In the northwest, fadeouts occurred yearly, and the average age at infection and the fadeout were negatively correlated with the population density. In the southeast, HFMD transmission was governed by the combined effects of the birth rate, the relative humidity and the interaction of the Health System Performance and the log of the population density. When the Health System Performance was low, HFMD transmission increased with the population density, but when the Health System Performance was high, the better health performance counteracted the transmission increase due to the higher population density.

An evaluation of the effects of eyeball structure on ocular pulse amplitude in healthy subjects.

PubMed

Ishii, Kotaro; Mori, Mikiro; Oshika, Tetsuro

2012-12-01

To evaluate the effects of eyeball structure on ocular pulse amplitude (OPA) measured using dynamic contour tonometer (DCT). In 86 eyes of 43 healthy subjects, we measured OPA and intraocular pressure (IOP) with DCT (DCT-IOP), IOP with Goldmann applanation tonometry (GAT-IOP), central corneal thickness (CCT), corneal thickness 2 mm (2 mmCT) and 4 mm (4 mmCT) apart from the center, corneal volume within a 3.5-mm radius from the corneal center, corneal curvature, anterior chamber depth, anterior chamber volume, and axial length (AL). OPA had a significant positive correlation with GAT-IOP (Pearson's r = 0.412, p < 0.001), DCT-IOP (r = 0.350, p < 0.001), and 4 mmCT (r = 0.244, p = 0.0231), and had a significant negative correlation with AL (r = -0.268, p = 0.0122). In a multiple linear regression analysis, AL and GAT-IOP were significantly associated with OPA. OPA measured with DCT is significantly influenced by several factors, such as IOP, peripheral corneal thickness (4 mmCT), and AL.

Low-flow frequency analyses for streams in west-central Florida

USGS Publications Warehouse

Hammett, K.M.

1985-01-01

The log-Pearson type III distribution was used for defining low-flow frequency at 116 continuous-record streamflow stations in west-central Florida. Frequency distributions were calculated for 1, 3, 7, 14, 30, 60, 90, 120, and 183 consecutive-day periods for recurrence intervals of 2, 5, 10, and 20 years. Discharge measurements at more than 100 low-flow partial-record stations and miscellaneous discharge-measurement stations were correlated with concurrent daily mean discharge at continuous-record stations. Estimates of the 7-day, 2-year; 7-day, 10-year; 30-day, 2-year; and 30-day, 10-year discharges were made for most of the low-flow partial-record and miscellaneous discharge-measurement stations based on those correlations. Multiple linear-regression analysis was used in an attempt to mathematically relate low-flow frequency data to basin characteristics. The resulting equations showed an apparent bias and were considered unsatisfactory for use in estimating low-flow characteristics. Maps of the 7-day, 10-year and 30-day, 10-year low flows are presented. Techniques that can be used to estimate low-flow characteristics at an ungaged site are also provided. (USGS)

Variability of carotid artery measurements on 3-Tesla MRI and its impact on sample size calculation for clinical research.

PubMed

Syed, Mushabbar A; Oshinski, John N; Kitchen, Charles; Ali, Arshad; Charnigo, Richard J; Quyyumi, Arshed A

2009-08-01

Carotid MRI measurements are increasingly being employed in research studies for atherosclerosis imaging. The majority of carotid imaging studies use 1.5 T MRI. Our objective was to investigate intra-observer and inter-observer variability in carotid measurements using high resolution 3 T MRI. We performed 3 T carotid MRI on 10 patients (age 56 +/- 8 years, 7 male) with atherosclerosis risk factors and ultrasound intima-media thickness > or =0.6 mm. A total of 20 transverse images of both right and left carotid arteries were acquired using T2 weighted black-blood sequence. The lumen and outer wall of the common carotid and internal carotid arteries were manually traced; vessel wall area, vessel wall volume, and average wall thickness measurements were then assessed for intra-observer and inter-observer variability. Pearson and intraclass correlations were used in these assessments, along with Bland-Altman plots. For inter-observer variability, Pearson correlations ranged from 0.936 to 0.996 and intraclass correlations from 0.927 to 0.991. For intra-observer variability, Pearson correlations ranged from 0.934 to 0.954 and intraclass correlations from 0.831 to 0.948. Calculations showed that inter-observer variability and other sources of error would inflate sample size requirements for a clinical trial by no more than 7.9%, indicating that 3 T MRI is nearly optimal in this respect. In patients with subclinical atherosclerosis, 3 T carotid MRI measurements are highly reproducible and have important implications for clinical trial design.

Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit.

PubMed

Marics, Gábor; Koncz, Levente; Eitler, Katalin; Vatai, Barbara; Szénási, Boglárka; Zakariás, David; Mikos, Borbála; Körner, Anna; Tóth-Heyn, Péter

2015-03-19

Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion. In 38 pediatric patients (age range, 0-18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson's correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05). CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson's correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson's correlation coefficient: 0.83). The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions.

Fracture pattern interpretation in the skull: differentiating blunt force from ballistics trauma using concentric fractures.

PubMed

Hart, Gina O

2005-11-01

There have been several anthropological studies on trauma analysis in recent literature, but few studies have focused on the differences between the three mechanisms of trauma (sharp force trauma, blunt force trauma and ballistics trauma). The hypothesis of this study is that blunt force and ballistics fracture patterns in the skull can be differentiated using concentric fractures. Two-hundred and eleven injuries from skulls exhibiting concentric fractures were examined to determine if the mechanism of trauma could be determined by beveling direction. Fractures occurring in buttressed and non-buttressed regions were examined separately. Contingency tables and Pearson's Chi-Square were used to evaluate the relationship between the two variables (the mechanism of trauma and the direction of beveling), while Pearson's r correlation was used to determine the strength of the relationship. Contingency tables and Chi-square tests among the entire sample, the buttressed areas, and the non-buttressed areas led to the null hypothesis (no relationship) to be rejected. Pearson's r correlation indicated that the relationship between the variables studied is greater than chance allocation.

Microperimetric correlations of autofluorescence and optical coherence tomography imaging in dry age-related macular degeneration.

PubMed

Querques, Lea; Querques, Giuseppe; Forte, Raimondo; Souied, Eric H

2012-06-01

To investigate the microperimetric correlations of autofluorescence imaging and optical coherence tomography (OCT) in dry age-related macular degeneration (AMD). Retrospective, observational, cross-sectional study. Consecutive patients with dry AMD underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA), blue fundus autofluorescence (FAF), near-infrared autofluorescence, and spectral-domain (SD)-OCT with integrated microperimetry. A total of 58 eyes of 29 patients (21 women; mean age 73 ± 9 years) were included. Mean BCVA was 0.28 ± 0.3 logarithm of the minimal angle of resolution (logMAR). Overall, 2842 points were analyzed as regards FAF and near-infrared autofluorescence patterns, the status of inner segment/outer segment (IS/OS) interface, and retinal sensitivity. We observed a good correlation between the FAF and near-infrared autofluorescence patterns for all the points graded (increased FAF/near-infrared autofluorescence, Pearson rho = 0.6, P = .02; decreased FAF/near-infrared autofluorescence, Pearson rho = 0.7, P = .01; normal FAF/near-infrared autofluorescence, Pearson rho = 0.7, P = .01). Mean retinal sensitivity was significantly reduced in cases of decreased FAF (4.73 ± 2.23 dB) or increased FAF (4.75 ± 2.39 dB) compared with normal FAF (7.44 ± 2.34 dB) (P = .001). Mean retinal sensitivity was significantly reduced in case of decreased near-infrared autofluorescence (3.87 ± 2.28 dB), compared with increased near-infrared autofluorescence (5.76 ± 2.44 dB) (P = .02); mean retinal sensitivity in case of increased near-infrared autofluorescence was significantly reduced compared with normal near-infrared autofluorescence (7.15 ± 2.38 dB) (P = .002). On SD-OCT, there was a high inverse correlation between retinal sensitivity and rate of disruptions in IS/OS interface (Pearson rho = -0.72, P = .001). A reduced retinal sensitivity consistently correlates with decreased FAF/near-infrared autofluorescence and a disrupted IS/OS interface. Increased near-infrared autofluorescence may represent a useful method for detection of retinal abnormalities early in dry AMD development. Copyright © 2012 Elsevier Inc. All rights reserved.

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…

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.

Religious Moral Beliefs Inversely Related to Trauma Experiences Severity and Presented Posttraumatic Stress Disorder Among Bosnia and Herzegovina War Veterans.

PubMed

Hasanović, Mevludin; Pajević, Izet

2015-08-01

The aim of this study was to determine the correlation of the level of religious moral beliefs (RMB) with trauma experiences and posttraumatic stress disorder (PTSD) severity in war veterans of Bosnia and Herzegovina. The sample consists of 120 Bosnian war veterans divided into two equal groups-one with and one without PTSD. We used the Harvard Trauma Questionnaire and the RMB belief scale. We then correlated the severity of trauma experiences and PTSD symptoms with veterans' scores on the RMB scale. The score on the RMB scale was negatively correlated to severity of trauma experiences and PTSD symptoms (Pearson's r = -0.509, P = 0.004; Pearson's r = -0.325, P < 0.001, respectively). The RMB may have protective role in the mental health stability of severely traumatized war veterans.

Accuracy of clinical observations of push-off during gait after stroke.

PubMed

McGinley, Jennifer L; Morris, Meg E; Greenwood, Ken M; Goldie, Patricia A; Olney, Sandra J

2006-06-01

To determine the accuracy (criterion-related validity) of real-time clinical observations of push-off in gait after stroke. Criterion-related validity study of gait observations. Rehabilitation hospital in Australia. Eleven participants with stroke and 8 treating physical therapists. Not applicable. Pearson product-moment correlation between physical therapists' observations of push-off during gait and criterion measures of peak ankle power generation from a 3-dimensional motion analysis system. A high correlation was obtained between the observational ratings and the measurements of peak ankle power generation (Pearson r =.98). The standard error of estimation of ankle power generation was .32W/kg. Physical therapists can make accurate real-time clinical observations of push-off during gait following stroke.

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.

Selling blood and gametes during tough economic times: insights from Google search.

PubMed

Wu, Jonathan A; Ngo, Tin C; Rothman, Cappy; Breyer, Benjamin N; Eisenberg, Michael L

2015-10-01

To use Google Insights search volume and publicly available economic indicators to test the hypothesis that sperm, egg, and blood donations increase during economic downturns and to demonstrate the feasibility of using Google search volume data to predict national trends in actual sperm, egg, and blood donations rates. Cross-correlation statistical analysis comparing Google search data for terms relating to blood, egg, and sperm donations with various economic indicators including the S&P 500 closing values, gross domestic product (GDP), the U.S. Index of Leading Indicators (U.S. Leading Index), gross savings rate, mortgage interest rates, unemployment rate, and consumer price index (CPI) from 2004-2011. A secondary analysis determined the Pearson correlation coefficient between Google search data with actual sperm, egg, and blood donation volume in the U.S. as measured by California Cryobank, the National Assisted Reproductive Technology Surveillance System, and the National Blood Collection and Utilization Survey, respectively. Significance of cross-correlation and Pearson correlation analysis as indicated by p value. There were several highly significant cross-correlation relationships between search volume and various economic indicators. Correlation between Google search volume for the term 'sperm donation,' 'egg donation,' and 'blood donation' with actual number of sperm, egg and blood donations in the United States demonstrated Pearson correlation coefficients of 0.2 (p > 0.10), -0.1 (p > 0.10), and 0.07 (p > 0.10), respectively. Temporal analysis showed an improved correlation coefficient of 0.9 (p < 0.05) for blood donation when shifted 12 months later relative to Google search volume. Google search volume data for search terms relating to sperm, egg, and blood donation increase during economic downturns. This finding suggests gamete and bodily fluid donations are influenced by market forces like other commodities. Google search may be useful for predicting blood donation trends but is more limited in predicting actual semen and oocyte donation patterns.

Alterations in retinal nerve fiber layer thickness in early stages of diabetic retinopathy and potential risk factors.

PubMed

Shi, Rui; Guo, Zhonglan; Wang, Feng; Li, Rong; Zhao, Lei; Lin, Rong

2018-02-01

To investigate the loss of retinal nerve fiber layer (RNFL) in type-2 diabetic patients with early-stage diabetic retinopathy (DR) and to identify potential risk factors accounting for these alterations. In this cross-sectional study, 158 type-2 diabetic patients were divided into three groups based on their DR status. RNFL thickness and other optic disc parameters were obtained by optical coherence tomography (OCT) and then compared among different groups. We investigated the potential association between RNFL loss and systemic risk factors for DR, including diabetes duration, body mass index (BMI), serum lipids, hemoglobin A1c (HbA1c) and albumin-creatinine ratio (ACR). One-way ANOVA was carried out to compare RNFL thickness among different groups, Pearson correlation and multivariate linear regression analysis were performed to determine potential risk factors related to RNFL thickness in these patients. There were significant differences in the average (F = 8.872, P = 0.003), superior (F = 8.769, P = 0.004), and inferior (F = 8.857, P = 0.003) RNFL thickness of both eyes among the groups, but no obvious difference in optic disc parameters was found. Diabetic duration, BMI, TG, High density lipoprotein cholesterol (HDL), HbA1c, and ACR were found negatively related to the RNFL thickness in both or single eye according to Pearson correlation analysis. After controlling for age, gender, and axis length (AL) in multivariate linear regression analysis, the diabetic duration was associated significantly with RNFL thickness of superior in both eye (right eye: p = 0.016, left eye: p = 0.024), BMI was related to the nasal quadrant of the right eye (p = 0.034), and TG was related to the inferior of the right eye (p = 0.037), HbA1c (p = 0.026) was associated significantly with the average RNFL thickness of the right eye. In addition, ACR was found negatively related to average (p = 0.042) and inferior quadrant (p = 0.014) of the left eye, respectively. RNFL loss might be the earliest structural change of retina in diabetic patients, and associated with diabetic duration, BMI, TG, HbA1c, and ACR. The conclusions of this study need to be proved by other well-matched and large-scale prospective clinical trials in the future, because the correlations discovered in our study were weak.

Best method for right atrial volume assessment by two-dimensional echocardiography: validation with magnetic resonance imaging.

PubMed

Ebtia, Mahasti; Murphy, Darra; Gin, Kenneth; Lee, Pui K; Jue, John; Nair, Parvathy; Mayo, John; Barnes, Marion E; Thompson, Darby J S; Tsang, Teresa S M

2015-05-01

Echocardiographic methods for estimating right atrial (RA) volume have not been standardized. Our aim was to evaluate two-dimensional (2D) echocardiographic methods of RA volume assessment, using RA volume by magnetic resonance imaging (MRI) as the reference. Right atrial volume was assessed in 51 patients (mean age 63 ± 14 years, 33 female) who underwent comprehensive 2D echocardiography and cardiac MRI for clinically indicated reasons. Echocardiographic RA volume methods included (1) biplane area length, using four-chamber view twice (biplane 4C-4C); (2) biplane area length, using four-chamber and subcostal views (biplane 4C-subcostal); and (3) single plane Simpson's method of disks (Simpson's). Echocardiographic RA volumes as well as linear RA major and minor dimensions were compared to RA volume by MRI using correlation and Bland-Altman methods, and evaluated for inter-observer reproducibility and accuracy in discriminating RA enlargement. All echocardiography volumetric methods performed well compared to MRI, with Pearson's correlation of 0.98 and concordance correlation ≥0.91 for each. For bias and limits of agreement, biplane 4C-4C (bias -4.81 mL/m(2) , limits of agreement ±9.8 mL/m(2) ) and Simpson's (bias -5.15 mL/m(2) , limits of agreement ±10.1 mL/m(2) ) outperformed biplane 4C-subcostal (bias -8.36 mL/m(2) , limits of agreement ±12.5 mL/m(2) ). Accuracy for discriminating RA enlargement was higher for all volumetric methods than for linear measurements. Inter-observer variability was satisfactory across all methods. Compared to MRI, biplane 4C-4C and single plane Simpson's are highly accurate and reproducible 2D echocardiography methods for estimating RA volume. Linear dimensions are inaccurate and should be abandoned. © 2014, Wiley Periodicals, Inc.

Concurrent validity of Physiological Cost Index in walking over ground and during robotic training in subacute stroke patients.

PubMed

Delussu, Anna Sofia; Morone, Giovanni; Iosa, Marco; Bragoni, Maura; Paolucci, Stefano; Traballesi, Marco

2014-01-01

Physiological Cost Index (PCI) has been proposed to assess gait demand. The purpose of the study was to establish whether PCI is a valid indicator in subacute stroke patients of energy cost of walking in different walking conditions, that is, over ground and on the Gait Trainer (GT) with body weight support (BWS). The study tested if correlations exist between PCI and ECW, indicating validity of the measure and, by implication, validity of PCI. Six patients (patient group (PG)) with subacute stroke and 6 healthy age- and size-matched subjects as control group (CG) performed, in a random sequence in different days, walking tests overground and on the GT with 0, 30, and 50% BWS. There was a good to excellent correlation between PCI and ECW in the observed walking conditions: in PG Pearson correlation was 0.919 (p < 0.001); in CG Pearson correlation was 0.852 (p < 0.001). In conclusion, the high significant correlations between PCI and ECW, in all the observed walking conditions, suggest that PCI is a valid outcome measure in subacute stroke patients.

Student Bedtimes, Academic Performance, and Health in a Residential High School.

PubMed

Wernette, Maliah J; Emory, Jan

2017-08-01

Inadequate sleep among adolescents is considered an epidemic in the United States. Late night bedtimes could be an important factor in academic performance and health with consequences continuing throughout adulthood. The purpose of this study was to explore the relationships between late night bedtimes, academic performance (grade point average [GPA]), and utilization of health care (school nurse visits) in a residential high school. The data were collected from archival records for one academic semester. The statistical analysis employed the nonparametric Pearson's correlation coefficient ( r) with the standard level of significance (α = .05). Positive and inverse linear relationships were found between bedtime and school nurse visits ( p < .00001) and bedtime and GPA ( p = .007). The findings suggest students' late night bedtimes may be related to increased school nurse visits and lower academic performance. Adolescent late night bedtimes may be an important consideration for academic success and maintaining health in residential high schools.

Fat quantification and analysis of lung transplant patients on unenhanced chest CT images based on standardized anatomic space

NASA Astrophysics Data System (ADS)

Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.; Wu, Caiyun; Christie, Jason; Lederer, David J.

2016-03-01

Chest fat estimation is important for identifying high-risk lung transplant candidates. In this paper, an approach to chest fat quantification based on a recently formulated concept of standardized anatomic space (SAS) is presented. The goal of this paper is to seek answers to the following questions related to chest fat quantification on single slice versus whole volume CT, which have not been addressed in the literature. What level of correlation exists between total chest fat volume and fat areas measured on single abdominal and thigh slices? What is the anatomic location in the chest where maximal correlation of fat area with fat volume can be expected? Do the components of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) have the same area-to-volume correlative behavior or do they differ? The SAS approach includes two steps: calibration followed by transformation which will map the patient slice locations non-linearly to SAS. The optimal slice locations found for SAT and VAT based on SAS are different and at the mid-level of the T8 vertebral body for SAT and mid-level of the T7 vertebral body for VAT. Fat volume and area on optimal slices for SAT and VAT are correlated with Pearson correlation coefficients of 0.97 and 0.86, respectively. The correlation of chest fat volume with abdominal and thigh fat areas is weak to modest.

Metabolites as novel biomarkers for childhood obesity-related traits in Mexican-American children.

PubMed

Farook, V S; Reddivari, L; Chittoor, G; Puppala, S; Arya, R; Fowler, S P; Hunt, K J; Curran, J E; Comuzzie, A G; Lehman, D M; Jenkinson, C P; Lynch, J L; DeFronzo, R A; Blangero, J; Hale, D E; Duggirala, R; Vanamala, J

2015-08-01

Although newer approaches have identified several metabolites associated with obesity, there is paucity of such information in paediatric populations, especially among Mexican-Americans (MAs) who are at high risk of obesity. Therefore, we performed a global serum metabolite screening in MA children to identify biomarkers of childhood obesity. We selected 15 normal-weight, 13 overweight and 14 obese MA children (6-17 years) and performed global serum metabolite screening using ultra-performance liquid chromatography/quadruple orthogonal acceleration time of flight tandem micro mass spectrometer. Metabolite values were analysed to assess mean differences among groups using one-way analysis of variance, to test for linear trend across groups and to examine Pearson's correlations between them and seven cardiometabolic traits (CMTs): body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, homeostasis model of assessment-insulin resistance, triglycerides and high-density lipoprotein cholesterol. We identified 14 metabolites exhibiting differences between groups as well as linear trend across groups with nominal statistical significance. After adjustment for multiple testing, mean differences and linear trends across groups remained significant (P < 5.9 × 10(-5) ) for L-thyronine, bradykinin and naringenin. Of the examined metabolite-CMT trait pairs, all metabolites except for 2-methylbutyroylcarnitine were nominally associated with two or more CMTs, some exhibiting significance even after accounting for multiple testing (P < 3.6 × 10(-3) ). To our knowledge, this study - albeit pilot in nature - is the first study to identify these metabolites as novel biomarkers of childhood obesity and its correlates. These findings signify the need for future systematic investigations of metabolic pathways underlying childhood obesity. © 2014 World Obesity.

Validation of a Video Analysis Software Package for Quantifying Movement Velocity in Resistance Exercises.

PubMed

Sañudo, Borja; Rueda, David; Pozo-Cruz, Borja Del; de Hoyo, Moisés; Carrasco, Luis

2016-10-01

Sañudo, B, Rueda, D, del Pozo-Cruz, B, de Hoyo, M, and Carrasco, L. Validation of a video analysis software package for quantifying movement velocity in resistance exercises. J Strength Cond Res 30(10): 2934-2941, 2016-The aim of this study was to establish the validity of a video analysis software package in measuring mean propulsive velocity (MPV) and the maximal velocity during bench press. Twenty-one healthy males (21 ± 1 year) with weight training experience were recruited, and the MPV and the maximal velocity of the concentric phase (Vmax) were compared with a linear position transducer system during a standard bench press exercise. Participants performed a 1 repetition maximum test using the supine bench press exercise. The testing procedures involved the simultaneous assessment of bench press propulsive velocity using 2 kinematic (linear position transducer and semi-automated tracking software) systems. High Pearson's correlation coefficients for MPV and Vmax between both devices (r = 0.473 to 0.993) were observed. The intraclass correlation coefficients for barbell velocity data and the kinematic data obtained from video analysis were high (>0.79). In addition, the low coefficients of variation indicate that measurements had low variability. Finally, Bland-Altman plots with the limits of agreement of the MPV and Vmax with different loads showed a negative trend, which indicated that the video analysis had higher values than the linear transducer. In conclusion, this study has demonstrated that the software used for the video analysis was an easy to use and cost-effective tool with a very high degree of concurrent validity. This software can be used to evaluate changes in velocity of training load in resistance training, which may be important for the prescription and monitoring of training programmes.

Estimation of Fetal Weight during Labor: Still a Challenge.

PubMed

Barros, Joana Goulão; Reis, Inês; Pereira, Isabel; Clode, Nuno; Graça, Luís M

2016-01-01

To evaluate the accuracy of fetal weight prediction by ultrasonography labor employing a formula including the linear measurements of femur length (FL) and mid-thigh soft-tissue thickness (STT). We conducted a prospective study involving singleton uncomplicated term pregnancies within 48 hours of delivery. Only pregnancies with a cephalic fetus admitted in the labor ward for elective cesarean section, induction of labor or spontaneous labor were included. We excluded all non-Caucasian women, the ones previously diagnosed with gestational diabetes and the ones with evidence of ruptured membranes. Fetal weight estimates were calculated using a previously proposed formula [estimated fetal weight = 1687.47 + (54.1 x FL) + (76.68 x STT). The relationship between actual birth weight and estimated fetal weight was analyzed using Pearson's correlation. The formula's performance was assessed by calculating the signed and absolute errors. Mean weight difference and signed percentage error were calculated for birth weight divided into three subgroups: < 3000 g; 3000-4000 g; and > 4000 g. We included for analysis 145 cases and found a significant, yet low, linear relationship between birth weight and estimated fetal weight (p < 0.001; R2 = 0.197) with an absolute mean error of 10.6%. The lowest mean percentage error (0.3%) corresponded to the subgroup with birth weight between 3000 g and 4000 g. This study demonstrates a poor correlation between actual birth weight and the estimated fetal weight using a formula based on femur length and mid-thigh soft-tissue thickness, both linear parameters. Although avoidance of circumferential ultrasound measurements might prove to be beneficial, it is still yet to be found a fetal estimation formula that can be both accurate and simple to perform.

Statistical analysis of co-occurrence patterns in microbial presence-absence datasets.

PubMed

Mainali, Kumar P; Bewick, Sharon; Thielen, Peter; Mehoke, Thomas; Breitwieser, Florian P; Paudel, Shishir; Adhikari, Arjun; Wolfe, Joshua; Slud, Eric V; Karig, David; Fagan, William F

2017-01-01

Drawing on a long history in macroecology, correlation analysis of microbiome datasets is becoming a common practice for identifying relationships or shared ecological niches among bacterial taxa. However, many of the statistical issues that plague such analyses in macroscale communities remain unresolved for microbial communities. Here, we discuss problems in the analysis of microbial species correlations based on presence-absence data. We focus on presence-absence data because this information is more readily obtainable from sequencing studies, especially for whole-genome sequencing, where abundance estimation is still in its infancy. First, we show how Pearson's correlation coefficient (r) and Jaccard's index (J)-two of the most common metrics for correlation analysis of presence-absence data-can contradict each other when applied to a typical microbiome dataset. In our dataset, for example, 14% of species-pairs predicted to be significantly correlated by r were not predicted to be significantly correlated using J, while 37.4% of species-pairs predicted to be significantly correlated by J were not predicted to be significantly correlated using r. Mismatch was particularly common among species-pairs with at least one rare species (<10% prevalence), explaining why r and J might differ more strongly in microbiome datasets, where there are large numbers of rare taxa. Indeed 74% of all species-pairs in our study had at least one rare species. Next, we show how Pearson's correlation coefficient can result in artificial inflation of positive taxon relationships and how this is a particular problem for microbiome studies. We then illustrate how Jaccard's index of similarity (J) can yield improvements over Pearson's correlation coefficient. However, the standard null model for Jaccard's index is flawed, and thus introduces its own set of spurious conclusions. We thus identify a better null model based on a hypergeometric distribution, which appropriately corrects for species prevalence. This model is available from recent statistics literature, and can be used for evaluating the significance of any value of an empirically observed Jaccard's index. The resulting simple, yet effective method for handling correlation analysis of microbial presence-absence datasets provides a robust means of testing and finding relationships and/or shared environmental responses among microbial taxa.

Assessment of Correlation Between Early and Late Efficacy Endpoints to Identify Potential Surrogacy Relationships in Non-Hodgkin Lymphoma: a Literature-Based Meta-analysis of 108 Phase II and Phase III Studies.

PubMed

Zhu, Rui; Lu, Dan; Chu, Yu-Waye; Chai, Akiko; Green, Michelle; Zhang, Nancy; Jin, Jin Yan

2017-05-01

Correlations between early and late efficacy endpoints were assessed to identify potential surrogate endpoints for overall survival (OS) or progression-free survival (PFS) with clinical trial-level data in three non-Hodgkin lymphoma (NHL) subtypes: diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and mantle cell lymphoma (MCL). One hundred and eight phase II-III trials (129 trial arms) in DLBCL, FL, and MCL were identified and included in the database. Correlations between efficacy endpoints were analyzed using weighted linear regression and Pearson's coefficient of determination (R 2 ). In newly diagnosed DLBCL, 6-month PFS was strongly correlated with 2-year OS (R 2  = 0.81, 95% confidence interval [CI] 0.51-0.96). Six-month PFS was strongly correlated with 3-year PFS (R 2  = 0.89, 95% CI 0.62-0.96) in FL and was moderately correlated with 2-year OS (R 2  = 0.69, 95% CI 0.40-0.91) in MCL trials. Linear regression determined that a 10% increase in 6-month PFS would yield a 13% ± 1.2% increase in 2-year OS in DLBCL, a 23% ± 1.1% increase in 3-year PFS in FL, or a 6.7% ± 1.0% increase in 2-year OS in MCL. Both 6-month PFS and complete response (CR) rate were moderately correlated with median PFS in FL trials with R 2  = 0.66 (95% CI 0.52-0.98) and R 2  = 0.69 (95% CI 0.22-0.89), respectively. Six-month PFS is a potential surrogate endpoint for 2-year OS in newly diagnosed DLBCL and MCL and for 3-year PFS in FL. Both 6-month PFS and CR rate are potential surrogate endpoints for median PFS in FL patients. Confirmation and validation of these correlations may facilitate early interpretation of NHL trials.

A preliminary biomechanical study of a novel carbon-fibre hip implant versus standard metallic hip implants.

PubMed

Bougherara, Habiba; Zdero, Rad; Dubov, Anton; Shah, Suraj; Khurshid, Shaheen; Schemitsch, Emil H

2011-01-01

Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based composite hip stem, the Exeter hip stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite stem stiffness (1982 N/mm) was lower than the metallic hip stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip stem compared to standard commercially-available devices. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

Correlation of Admission Metrics with Eventual Success in Mathematics Academic Performance of Freshmen in AMAIUB's Business Curricula

ERIC Educational Resources Information Center

Calucag, Lina S.; Talisic, Geraldo C.; Caday, Aileen B.

2016-01-01

This is a correlational study research design, which aimed to determine the correlation of admission metrics with eventual success in mathematics academic performance of the admitted 177 first year students of Bachelor of Science in Business Informatics and 59 first year students of Bachelor of Science in International Studies. Using Pearson's…

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.

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.

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.

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 initial stages of psychometric questionnaire validation.

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.

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

The Predictive Validity of the National Board of Osteopathic Medical Examiners' COMLEX-USA Examinations With Regard to Outcomes on American Board of Family Medicine Examinations.

PubMed

O'Neill, Thomas R; Peabody, Michael R; Song, Hao

2016-11-01

To examine the predictive validity of the National Board of Osteopathic Medical Examiners' Comprehensive Osteopathic Medical Licensing Examination of the United States of America (COMLEX-USA) series with regard to the American Board of Family Medicine's (ABFM's) In-Training Examination (ITE) and Maintenance of Certification for Family Physicians (MC-FP) Examination. A repeated-measures design was employed, using test scores across seven levels of training for 1,023 DOs who took the MC-FP for the first time between April 2012 and November 2014 and for whom the ABFM had ITE scores for each of their residency years. Pearson and disattenuated correlations were calculated; Fisher r to z transformation was performed; and sensitivity, specificity, and positive and negative predictive values for the COMLEX-USA Level 2-Cognitive Evaluation (CE) with regard to the MC-FP were computed. The Pearson and disattenuated correlations ranged from 0.55 to 0.69 and from 0.61 to 0.80, respectively. For MC-FP scores, only the correlation increase from the COMLEX-USA Level 2-CE to Level 3 was statistically significant (for Pearson correlations: z = 2.41, P = .008; for disattenuated correlations: z = 3.16, P < .001). The sensitivity, specificity, and positive and negative predictive values of the COMLEX-USA Level 2-CE with the MC-FP were 0.90, 0.39, 0.96, and 0.19, respectively. Evidence was found that the COMLEX-USA can assist family medicine residency program directors in predicting later resident performance on the ABFM's ITE and MC-FP, which is becoming increasingly important as graduate medical education accreditation moves toward a single aligned model.

Assessing exotic plant species invasions and associated soil characteristics: A case study in eastern Rocky Mountain National Park, Colorado, USA, using the pixel nested plot design

USGS Publications Warehouse

Kalkhan, M.A.; Stafford, E.J.; Woodly, P.J.; Stohlgren, T.J.

2007-01-01

Rocky Mountain National Park (RMNP), Colorado, USA, contains a diversity of plant species. However, many exotic plant species have become established, potentially impacting the structure and function of native plant communities. Our goal was to quantify patterns of exotic plant species in relation to native plant species, soil characteristics, and other abiotic factors that may indicate or predict their establishment and success. Our research approach for field data collection was based on a field plot design called the pixel nested plot. The pixel nested plot provides a link to multi-phase and multi-scale spatial modeling-mapping techniques that can be used to estimate total species richness and patterns of plant diversity at finer landscape scales. Within the eastern region of RMNP, in an area of approximately 35,000 ha, we established a total of 60 pixel nested plots in 9 vegetation types. We used canonical correspondence analysis (CCA) and multiple linear regressions to quantify relationships between soil characteristics and native and exotic plant species richness and cover. We also used linear correlation, spatial autocorrelation and cross correlation statistics to test for the spatial patterns of variables of interest. CCA showed that exotic species were significantly (P < 0.05) associated with photosynthetically active radiation (r = 0.55), soil nitrogen (r = 0.58) and bare ground (r = -0.66). Pearson's correlation statistic showed significant linear relationships between exotic species, organic carbon, soil nitrogen, and bare ground. While spatial autocorrelations indicated that our 60 pixel nested plots were spatially independent, the cross correlation statistics indicated that exotic plant species were spatially associated with bare ground, in general, exotic plant species were most abundant in areas of high native species richness. This indicates that resource managers should focus on the protection of relatively rare native rich sites with little canopy cover, and fertile soils. Using the pixel nested plot approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and cost-effective manner. ?? 2006 Elsevier B.V. All rights reserved.

A comparative evaluation of Oratest with the microbiological method of assessing caries activity in children

PubMed Central

Sundaram, Meenakshi; Nayak, Ullal Anand; Ramalingam, Krishnakumar; Reddy, Venugopal; Rao, Arun Prasad; Mathian, Mahesh

2013-01-01

Aims: The aim of this study is to find out whether Oratest can be used as a diagnostic tool in assessing the caries activity by evaluating its relationship to the existing caries status and the salivary streptococcus mutans level. Materials and Methods: The study sample consists of 90 students divided into two groups. Group I (test group) and Group II (control group) consisting of 30 children for control group and 60 children for test group. The sampling of unstimulated saliva for the estimation of streptococcus mutans was done as per the method suggested by Kohler and Bratthall. The plates were then incubated. Rough surface colonies were identified as streptococcus mutans on a pre-determined area of the tip (approximately 1.5 cm2) were counted for each side of spatula pressed against mitis salivarius bacitracin agar using digital colony counter. The results were expressed in colony forming units (CFU). Oratest was carried out in the same patients after the collection of salivary sample for the microbiological method to evaluate the relationship between the two tests. Statistical Analysis Used: The tests used were ANOVA, Pearson Chi-square test, Pearson′s correlation analysis, Mann-Whitney U test and Student′s independent t-test. Results: In the control group and test group, when the streptococcus mutans count (CFU) and Oratest time (minutes) were correlated using Pearson′s correlation analysis, the streptococcus mutans counts was found to be in a statistically significant negative linear relationship with the Oratest time. When the caries status of the children, participated in the test group were correlated with mutans count (CFU) and Oratest time, caries status were found to be in a statistically significant positive linear relationship with streptococcus mutans count and in a significant negative linear relationship with Oratest time. Conclusions: The test proved to be a simple, inexpensive and rapid technique for assessing caries activity since a significant relationship exists clinically with caries status and microbiologically with the streptococcus mutans count of the individual. PMID:23946577

Probability distribution functions for unit hydrographs with optimization using genetic algorithm

NASA Astrophysics Data System (ADS)

Ghorbani, Mohammad Ali; Singh, Vijay P.; Sivakumar, Bellie; H. Kashani, Mahsa; Atre, Atul Arvind; Asadi, Hakimeh

2017-05-01

A unit hydrograph (UH) of a watershed may be viewed as the unit pulse response function of a linear system. In recent years, the use of probability distribution functions (pdfs) for determining a UH has received much attention. In this study, a nonlinear optimization model is developed to transmute a UH into a pdf. The potential of six popular pdfs, namely two-parameter gamma, two-parameter Gumbel, two-parameter log-normal, two-parameter normal, three-parameter Pearson distribution, and two-parameter Weibull is tested on data from the Lighvan catchment in Iran. The probability distribution parameters are determined using the nonlinear least squares optimization method in two ways: (1) optimization by programming in Mathematica; and (2) optimization by applying genetic algorithm. The results are compared with those obtained by the traditional linear least squares method. The results show comparable capability and performance of two nonlinear methods. The gamma and Pearson distributions are the most successful models in preserving the rising and recession limbs of the unit hydographs. The log-normal distribution has a high ability in predicting both the peak flow and time to peak of the unit hydrograph. The nonlinear optimization method does not outperform the linear least squares method in determining the UH (especially for excess rainfall of one pulse), but is comparable.

Colour-stability and gloss-retention of silorane and dimethacrylate composites with accelerated aging.

PubMed

Furuse, Adilson Y; Gordon, Kathryn; Rodrigues, Flávia P; Silikas, Nick; Watts, David C

2008-11-01

To evaluate the colour-stability and gloss-retention of silorane versus dimethacrylate composites exposed to accelerated aging from daylight radiation. Five disc-shaped specimens of photo-cured resin-composites were prepared and manually polished for each material (Filtek Silorane, Herculite XRV, Tetric Evoceram and QuiXfil). Colour and gloss were evaluated before and after periods (baseline, 24, 72, 120 and 192 h) of accelerated photo-aging in xenon light following ISO 7491:2000. Colour measurements were performed with a colourimeter according to the CIE-Lab colour-space. The colour change (DeltaE) for each time was calculated. The surface gloss was measured using a glossmeter. Results were evaluated using one-way ANOVA and Tukey tests (alpha=0.05). Correlations between logtime, DeltaE and gloss were evaluated using Pearson's correlation (alpha=0.05). Materials generally decreased in L and a and increased in b. The strong exception was Filtek Silorane which maintained a and b. DeltaE was found to be a positive linear function of logtime for all materials. Materials varied in the magnitude and rate of increase of DeltaE with logtime: QuiXfil>Tetric EvoCeram>(Filtek Silorane>or=Herculite XRV). DeltaE remained<3.3 for Filtek Silorane and Herculite XRV. Gloss was found to be a negative linear function of logtime. Gloss was maximal in the sequence: Filtek Silorane approximately Tetric EvoCeram>Herculite XRV>QuiXfil. Silorane gave the best overall performance in stability over time, compared to a set of representative dimethacrylate composites.

Impact of sociodemographic variables on executive functions.

PubMed

Campanholo, Kenia Repiso; Boa, Izadora Nogueira Fonte; Hodroj, Flávia Cristina da Silva Araujo; Guerra, Glaucia Rosana Benute; Miotto, Eliane Correa; de Lucia, Mara Cristina Souza

2017-01-01

Executive functions (EFs) regulate human behavior and allow individuals to interact and act in the world. EFs are sensitive to sociodemographic variables such as age, which promotes their decline, and to others that can exert a neuroprotective effect. To assess the predictive role of education, occupation and family income on decline in executive functions among a sample with a wide age range. A total of 925 participants aged 18-89 years with 1-28 years' education were submitted to assessment of executive functions using the Card Sorting Test (CST), Phonemic Verbal Fluency (FAS) Task and Semantic Verbal Fluency (SVF) Task. Data on income, occupation and educational level were collected for the sample. The data were analyzed using Linear Regression, as well as Pearson's and Spearman's Correlation. Age showed a significant negative correlation (p<0.001) with performance on the CST, FAS and SVF, whereas education, income and occupation were positively associated (p<0.001) with the tasks applied. After application of the multivariate linear regression model, a significant positive relationship with the FAS was maintained only for education (p<0.001) and income (p<0.001). The negative relationship of age (p<0.001) and positive relationship of both education (p<0.001) and income (p<0.001and p=0.003) were evident on the CST and SVF. Educational level and income positively influenced participants' results on executive function tests, attenuating expected decline for age. However, no relationship was found between occupation and the cognitive variables investigated.

Impact of sociodemographic variables on executive functions

PubMed Central

Campanholo, Kenia Repiso; Boa, Izadora Nogueira Fonte; Hodroj, Flávia Cristina da Silva Araujo; Guerra, Glaucia Rosana Benute; Miotto, Eliane Correa; de Lucia, Mara Cristina Souza

2017-01-01

Executive functions (EFs) regulate human behavior and allow individuals to interact and act in the world. EFs are sensitive to sociodemographic variables such as age, which promotes their decline, and to others that can exert a neuroprotective effect. Objective To assess the predictive role of education, occupation and family income on decline in executive functions among a sample with a wide age range. Methods A total of 925 participants aged 18-89 years with 1-28 years' education were submitted to assessment of executive functions using the Card Sorting Test (CST), Phonemic Verbal Fluency (FAS) Task and Semantic Verbal Fluency (SVF) Task. Data on income, occupation and educational level were collected for the sample. The data were analyzed using Linear Regression, as well as Pearson's and Spearman's Correlation. Results Age showed a significant negative correlation (p<0.001) with performance on the CST, FAS and SVF, whereas education, income and occupation were positively associated (p<0.001) with the tasks applied. After application of the multivariate linear regression model, a significant positive relationship with the FAS was maintained only for education (p<0.001) and income (p<0.001). The negative relationship of age (p<0.001) and positive relationship of both education (p<0.001) and income (p<0.001and p=0.003) were evident on the CST and SVF. Conclusion Educational level and income positively influenced participants' results on executive function tests, attenuating expected decline for age. However, no relationship was found between occupation and the cognitive variables investigated. PMID:29213495

First-trimester visualization of the fourth ventricle in fetuses with and without spina bifida.

PubMed

Solt, Ido; Acuna, Joann G; Adeniji, Beni A; Mirocha, James; Kim, Matthew J; Rotmensch, Siegfried

2011-12-01

The purpose of this study was to examine the efficacy of nonvisualization of the fourth ventricle for first-trimester detection of spina bifida. A total of 250 digitally stored sonographic examinations at gestational ages of 11 weeks to 13 weeks 6 days (245 normal and 5 randomly interspersed spina bifida cases) were retrospectively analyzed by 4 blinded reviewers for the presence or absence of the fourth ventricle followed by an anteroposterior ventricular dimension measurement. The ventricle size was related to the crown-rump length and gestational age by linear regression analysis and Pearson correlation. The fourth ventricle was identified in 971 of 1000 image readings (97.1%). False-negative and false-positive readings occurred in 11 of 20 (55.0%) and 20 of 980 (2.0%) cases, respectively (sensitivity, 0.45; specificity, 0.98.). False-negative and false-positive readings were evenly distributed throughout the gestational age range. When the ventricular size was measurable, its mean dimensions increased linearly with gestational age and were below the fifth percentile in 10 of 245 (4.0%) normal and 0 of 4 spina bifida cases, respectively. Intraclass correlation coefficient estimates were calculated based on the 2-way analysis of variance model and found to be 0.30 for a single rater and 0.64 for the mean of 4 raters. Nonvisualization of the first-trimester fourth ventricle is a less robust screening parameter for spina bifida than previously published.

Does herpes zoster predispose to giant cell arteritis: a geo-epidemiologic study.

PubMed

Ing, Edsel B; Ing, Royce; Liu, Xinyang; Zhang, Angela; Torun, Nurhan; Sey, Michael; Pagnoux, Christian

2018-01-01

Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly and can cause irreversible blindness and aortitis. Varicella zoster (VZ), which is potentially preventable by vaccination, has been proposed as a possible immune trigger for GCA, but this is controversial. The incidence of GCA varies widely by country. If VZ virus contributes to the immunopathogenesis of GCA we hypothesized that nations with increased incidence of GCA would also have increased incidence of herpes zoster (HZ). We conducted an ecologic analysis to determine the relationship between the incidence of HZ and GCA in different countries. A literature search for the incidence rates (IRs) of GCA and HZ from different countries was conducted. Correlation and linear regression was performed comparing the disease IR of each country for subjects 50 years of age or older. We found the IR for GCA and HZ from 14 countries. Comparing the IRs for GCA and HZ in 50-year-olds, the Pearson product-moment correlation ( r ) was -0.51, with linear regression coefficient (β) -2.92 (95% CI -5.41, -0.43; p =0.025) using robust standard errors. Comparing the IRs for GCA and HZ in 70-year-olds, r was -0.40, with β -1.78, which was not statistically significant (95% CI -4.10, 0.53; p =0.12). Although this geo-epidemiologic study has potential for aggregation and selection biases, there was no positive biologic gradient between the incidence of clinically evident HZ and GCA.

Decreased Anti-Tumor Cytotoxic Immunity among Microsatellite-Stable Colon Cancers from African Americans.

PubMed

Basa, Ranor C B; Davies, Vince; Li, Xiaoxiao; Murali, Bhavya; Shah, Jinel; Yang, Bing; Li, Shi; Khan, Mohammad W; Tian, Mengxi; Tejada, Ruth; Hassan, Avan; Washington, Allen; Mukherjee, Bhramar; Carethers, John M; McGuire, Kathleen L

2016-01-01

Colorectal cancer is a leading cause of cancer related deaths in the U.S., with African-Americans having higher incidence and mortality rates than Caucasian-Americans. Recent studies have demonstrated that anti-tumor cytotoxic T lymphocytes provide protection to patients with colon cancer while patients deficient in these responses have significantly worse prognosis. To determine if differences in cytotoxic immunity might play a role in racial disparities in colorectal cancer 258 microsatellite-stable colon tumors were examined for infiltrating immune biomarkers via immunohistochemistry. Descriptive summary statistics were calculated using two-sample Wilcoxon rank sum tests, while linear regression models with log-transformed data were used to assess differences in race and Pearson and Spearman correlations were used to correlate different biomarkers. The association between different biomarkers was also assessed using linear regression after adjusting for covariates. No significant differences were observed in CD8+ (p = 0.83), CD57+ (p = 0.55), and IL-17-expressing (p = 0.63) cell numbers within the tumor samples tested. When infiltration of granzyme B+ cells was analyzed, however, a significant difference was observed, with African Americans having lower infiltration of cells expressing this cytotoxic marker than Caucasians (p<0.01). Analysis of infiltrating granzyme B+ cells at the invasive borders of the tumor revealed an even greater difference by race (p<0.001). Taken together, the data presented suggest differences in anti-tumor immune cytotoxicity may be a contributing factor in the racial disparities observed in colorectal cancer.

Factors Predicting a Good Symptomatic Outcome After Prostate Artery Embolisation (PAE).

PubMed

Maclean, D; Harris, M; Drake, T; Maher, B; Modi, S; Dyer, J; Somani, B; Hacking, N; Bryant, T

2018-02-26

As prostate artery embolisation (PAE) becomes an established treatment for benign prostatic obstruction, factors predicting good symptomatic outcome remain unclear. Pre-embolisation prostate size as a predictor is controversial with a handful of papers coming to conflicting conclusions. We aimed to investigate if an association existed in our patient cohort between prostate size and clinical benefit, in addition to evaluating percentage volume reduction as a predictor of symptomatic outcome following PAE. Prospective follow-up of 86 PAE patients at a single institution between June 2012 and January 2016 was conducted (mean age 64.9 years, range 54-80 years). Multiple linear regression analysis was performed to assess strength of association between clinical improvement (change in IPSS) and other variables, of any statistical correlation, through Pearson's bivariate analysis. No major procedural complications were identified and clinical success was achieved in 72.1% (n = 62) at 12 months. Initial prostate size and percentage reduction were found to have a significant association with clinical improvement. Multiple linear regression analysis (r 2  = 0.48) demonstrated that percentage volume reduction at 3 months (r = 0.68, p < 0.001) had the strongest correlation with good symptomatic improvement at 12 months after adjusting for confounding factors. Both the initial prostate size and percentage volume reduction at 3 months predict good symptomatic outcome at 12 months. These findings therefore aid patient selection and counselling to achieve optimal outcomes for men undergoing prostate artery embolisation.

Volitional and Real-Time Control Cursor Based on Eye Movement Decoding Using a Linear Decoding Model

PubMed Central

Zhang, Cheng

2016-01-01

The aim of this study is to build a linear decoding model that reveals the relationship between the movement information and the EOG (electrooculogram) data to online control a cursor continuously with blinks and eye pursuit movements. First of all, a blink detection method is proposed to reject a voluntary single eye blink or double-blink information from EOG. Then, a linear decoding model of time series is developed to predict the position of gaze, and the model parameters are calibrated by the RLS (Recursive Least Square) algorithm; besides, the assessment of decoding accuracy is assessed through cross-validation procedure. Additionally, the subsection processing, increment control, and online calibration are presented to realize the online control. Finally, the technology is applied to the volitional and online control of a cursor to hit the multiple predefined targets. Experimental results show that the blink detection algorithm performs well with the voluntary blink detection rate over 95%. Through combining the merits of blinks and smooth pursuit movements, the movement information of eyes can be decoded in good conformity with the average Pearson correlation coefficient which is up to 0.9592, and all signal-to-noise ratios are greater than 0. The novel system allows people to successfully and economically control a cursor online with a hit rate of 98%. PMID:28058044

Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain.

PubMed

Ishak, Nor Azizah; Zahari, Zarina; Justine, Maria

2017-01-01

This study aims (1) to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2) to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP). This is a correlational study, involving 63 institutionalized older persons (age = 70.98 ± 7.90 years) diagnosed with LBP. Anthropometric characteristics (BMI) and functional performances (lower limb function, balance and mobility, and hand grip strength) were measured. Muscle strength (abdominal and back muscle strength) was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus) was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson's correlation coefficients and multivariate linear regressions. No significant correlations were found between kinesiophobia and pain and muscle functions (all p > 0.05). Kinesiophobia was significantly correlated with mobility and balance ( p = 0.038, r = 0.263). Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance ( p = 0.038). We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient's compliance towards a rehabilitation program in older persons with LBP.

The Relationship between Family Functioning and Academic Achievement in Female High School Students of Isfahan, Iran, in 2013-2014.

PubMed

Rezaei-Dehaghani, Abdollah; Keshvari, Mahrokh; Paki, Somayeh

2018-01-01

Nowadays, the most important problem of the educational system is the vast spread of school failure. Therefore, detection of the factors leading to or preventing students' academic achievement is of utmost importance. Family function is considered to be a critical component of academic success. This study aimed to investigate the relationship between family functioning and academic achievement in high school female students in Isfahan. This descriptive correlational study was conducted through random sampling among 237 female high school students in Isfahan during school year 2013-2014. Data were collected by participants' personal characteristics and Bloom family function questionnaires. To analyze the data, descriptive statistics (mean and standard deviation) and inferential statistics (Pearson correlation and linear regression analysis) were adopted and computed using SPSS software. The results showed a significant correlation between family function (except lack of independence) and students' academic achievement ( p < 0.05). Further, among family function dimensions, expressiveness ( β = 0.235, p < 0.001), family socialization ( β = 0.219, p = 0.001), and cohesion ( β = 0.211, p = 0.001) were more reliable predictors of academic achievement. The results of this study showed that students' academic achievement is highly correlated with the performance of their families. Therefore, to improve students' educational status in cultural and educational programs, which are specified for them, family function centered plans should be at the heart of attention.

Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain

PubMed Central

2017-01-01

Objectives This study aims (1) to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2) to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP). Methods This is a correlational study, involving 63 institutionalized older persons (age = 70.98 ± 7.90 years) diagnosed with LBP. Anthropometric characteristics (BMI) and functional performances (lower limb function, balance and mobility, and hand grip strength) were measured. Muscle strength (abdominal and back muscle strength) was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus) was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson's correlation coefficients and multivariate linear regressions. Results No significant correlations were found between kinesiophobia and pain and muscle functions (all p > 0.05). Kinesiophobia was significantly correlated with mobility and balance (p = 0.038, r = 0.263). Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance (p = 0.038). Conclusion We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient's compliance towards a rehabilitation program in older persons with LBP. PMID:28634547

Relationship of Social Cognitive Theory Concepts to Dietary Habits of Pregnant Women.

PubMed

Torkan, Nasrin; Kazemi, Ashraf; Paknahad, Zamzam; Bahadoran, Parvin

2018-01-01

Nutrition during pregnancy is undoubtedly one of the most important factors affecting maternal health. In this regard, considering the cognitive-behavioral factors associated with feeding, behaviors will play an important role in the effectiveness of interventions. Therefore, this study aimed to investigate the correlation between food habits and structures of social cognitive theory in pregnant women. In this cross-sectional study, 192 pregnant women were randomly selected. Data were collected using a questionnaire based on the social cognitive theory structures and food habits questionnaire in the questioning manner and was also analyzed using Pearson correlation and multiple linear regression with the software Statistical Package for the Social Sciences, version 19. There was a significant correlation between nutritional behavior with self-regulation ( p = 0.001), self-efficacy ( p = 0.001), outcome expectations ( p = 0.001), social support ( p = 0.002), and access ( p = 0.001). A significant correlation was observed between lack of consumption of unnecessary and unhelpful food with self-regulation ( p = 0.02). In the multivariable regression analysis, only self-regulation revealed significant and direct contribution in relation to nutritional behavior ( p < 0.001). Results of this study showed that self-regulation is one of the important factors associated with feeding behavior in pregnant women so that it is suggested to be considered in nutritional interventions in order to improve nutritional behavior.

Relationship of Social Cognitive Theory Concepts to Dietary Habits of Pregnant Women

PubMed Central

Torkan, Nasrin; Kazemi, Ashraf; Paknahad, Zamzam; Bahadoran, Parvin

2018-01-01

Background: Nutrition during pregnancy is undoubtedly one of the most important factors affecting maternal health. In this regard, considering the cognitive-behavioral factors associated with feeding, behaviors will play an important role in the effectiveness of interventions. Therefore, this study aimed to investigate the correlation between food habits and structures of social cognitive theory in pregnant women. Materials and Methods: In this cross-sectional study, 192 pregnant women were randomly selected. Data were collected using a questionnaire based on the social cognitive theory structures and food habits questionnaire in the questioning manner and was also analyzed using Pearson correlation and multiple linear regression with the software Statistical Package for the Social Sciences, version 19. Results: There was a significant correlation between nutritional behavior with self-regulation (p = 0.001), self-efficacy (p = 0.001), outcome expectations (p = 0.001), social support (p = 0.002), and access (p = 0.001). A significant correlation was observed between lack of consumption of unnecessary and unhelpful food with self-regulation (p = 0.02). In the multivariable regression analysis, only self-regulation revealed significant and direct contribution in relation to nutritional behavior (p < 0.001). Conclusions: Results of this study showed that self-regulation is one of the important factors associated with feeding behavior in pregnant women so that it is suggested to be considered in nutritional interventions in order to improve nutritional behavior. PMID:29628960

Workers exposed to low levels of benzene present in urban air: Assessment of peripheral blood count variations.

PubMed

Casale, Teodorico; Sacco, Carmina; Ricci, Serafino; Loreti, Beatrice; Pacchiarotti, Alessandro; Cupelli, Vincenzo; Arcangeli, Giulio; Mucci, Nicola; Antuono, Vittorio; De Marco, Federica; Tomei, Gianfranco; Tomei, Francesco; Rosati, Maria Valeria

2016-06-01

Few studies in the literature have examined the effects of benzene on blood cells. The aim of this study was to evaluate the possible correlation between the blood benzene levels and the blood cell counts. From a population of 2658 workers, we studied a group of 215 subjects. Each worker underwent blood sampling for the assessment of the blood benzene levels and the blood cell counts. The Mann-Whitney U test for two-mode variables and the Kruskal-Wallis test for more-than-two-mode variables were performed on all subjects. We estimated the Pearson correlation index between the variables in the total sample and the subgroups divided according to sex, the smoking habit, and job. After the main confounding factors were evaluated, multiple linear regression was performed on both the total sample and the subgroups. A significant inverse correlation was found among the blood benzene levels and the white blood cells, lymphocytes, and neutrophils in traffic policemen, motorcyclists, and other outdoor workers. We did not find any significant correlation with any other parameters of blood cell count. Our results, which must be considered preliminary, indicate that increased blood benzene levels in outdoor workers lead to decreased counts of white blood cells, neutrophils, and lymphocytes, because of possible immune effects. These are worth investigating in the future by specific immune tests. Copyright © 2016. Published by Elsevier Ltd.

Lower Dietary Inflammatory Index Scores Are Associated with Lower Glycemic Index Scores among College Students.

PubMed

Kim, Yeonsoo; Chen, Jie; Wirth, Michael D; Shivappa, Nitin; Hebert, James R

2018-02-07

The association between the Dietary Inflammatory Index (DII ® ), the glycemic index (GI), and the glycemic load (GL) is not known, although it is known that carbohydrates are pro-inflammatory. We aimed to measure the association between the DII and both GI and GL among college students. In this cross-sectional study, 110 college students completed a 3-day food diary, which was used to calculate the DII, the GI, the GL, and the healthy eating index (HEI)-2010. Least square means and 95% confidence intervals of the GI, the GL, and the HEI-2010 were presented per DII tertile using generalized linear mixed models. Participants in tertile 1 of DII scores had lower GI and GL scores, but higher HEI-2010 scores than those in tertile 3. Pearson correlations showed that DII score was positively correlated with the GI score ( r = 0.30, p < 0.01), but negatively correlated with the HEI-2010 ( r = -0.56, p < 0.001). DII score was not correlated with GL score. Results from this study suggest that increased inflammatory potential of diet, as represented by higher DII scores, was associated with increased GI scores and lower quality of diet on the HEI-2010. Use of the DII suggests new directions for dietary approaches for preventing chronic diseases that moves beyond convention by decreasing systemic inflammation.

A comparison of acoustic and visual metrics of sperm whale longline depredation.

PubMed

Thode, Aaron M; Wild, Lauren; Mathias, Delphine; Straley, Janice; Lunsford, Christopher

2014-05-01

Annual federal stock assessment surveys for Alaskan sablefish also attempt to measure sperm whale depredation by quantifying visual evidence of depredation, including lip remains and damaged fish. A complementary passive acoustic method for quantifying depredation was investigated during the 2011 and 2012 survey hauls. A combination of machine-aided and human analysis counted the number of distinct “creak” sounds detected on autonomous recorders deployed during the survey, emphasizing sounds that are followed by silence (“creak-pauses”), a possible indication of prey capture. These raw counts were then adjusted for variations in background noise levels between deployments. Both a randomized Pearson correlation analysis and a generalized linear model found that noise-adjusted counts of “creak-pauses” were highly correlated with survey counts of lip remains during both years (2012: r(10) = 0.89, p = 1e-3; 2011: r(39) = 0.72, p = 4e-3) and somewhat correlated with observed sablefish damage in 2011 [r(39) = 0.37, p = 0.03], but uncorrelated with other species depredation. The acoustic depredation count was anywhere from 10% to 80% higher than the visual counts, depending on the survey year and assumptions employed. The results suggest that passive acoustics can provide upper bounds on depredation rates; however, the observed correlation breaks down whenever three or more whales are present.

Estimating the reliability of repeatedly measured endpoints based on linear mixed-effects models. A tutorial.

PubMed

Van der Elst, Wim; Molenberghs, Geert; Hilgers, Ralf-Dieter; Verbeke, Geert; Heussen, Nicole

2016-11-01

There are various settings in which researchers are interested in the assessment of the correlation between repeated measurements that are taken within the same subject (i.e., reliability). For example, the same rating scale may be used to assess the symptom severity of the same patients by multiple physicians, or the same outcome may be measured repeatedly over time in the same patients. Reliability can be estimated in various ways, for example, using the classical Pearson correlation or the intra-class correlation in clustered data. However, contemporary data often have a complex structure that goes well beyond the restrictive assumptions that are needed with the more conventional methods to estimate reliability. In the current paper, we propose a general and flexible modeling approach that allows for the derivation of reliability estimates, standard errors, and confidence intervals - appropriately taking hierarchies and covariates in the data into account. Our methodology is developed for continuous outcomes together with covariates of an arbitrary type. The methodology is illustrated in a case study, and a Web Appendix is provided which details the computations using the R package CorrMixed and the SAS software. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Accelerometer-Based Method for Extracting Respiratory and Cardiac Gating Information for Dual Gating during Nuclear Medicine Imaging

PubMed Central

Pänkäälä, Mikko; Paasio, Ari

2014-01-01

Both respiratory and cardiac motions reduce the quality and consistency of medical imaging specifically in nuclear medicine imaging. Motion artifacts can be eliminated by gating the image acquisition based on the respiratory phase and cardiac contractions throughout the medical imaging procedure. Electrocardiography (ECG), 3-axis accelerometer, and respiration belt data were processed and analyzed from ten healthy volunteers. Seismocardiography (SCG) is a noninvasive accelerometer-based method that measures accelerations caused by respiration and myocardial movements. This study was conducted to investigate the feasibility of the accelerometer-based method in dual gating technique. The SCG provides accelerometer-derived respiratory (ADR) data and accurate information about quiescent phases within the cardiac cycle. The correct information about the status of ventricles and atria helps us to create an improved estimate for quiescent phases within a cardiac cycle. The correlation of ADR signals with the reference respiration belt was investigated using Pearson correlation. High linear correlation was observed between accelerometer-based measurement and reference measurement methods (ECG and Respiration belt). Above all, due to the simplicity of the proposed method, the technique has high potential to be applied in dual gating in clinical cardiac positron emission tomography (PET) to obtain motion-free images in the future. PMID:25120563

The impact of insight on social functioning in patients with schizophrenia.

PubMed

Erol, Almila; Delibas, Hakan; Bora, Ozlem; Mete, Levent

2015-06-01

It is still unclear whether insight has a direct association with social functioning in schizophrenia, independent of its association with symptoms. This study aimed to investigate the relationship of insight and its dimensions with social functioning in schizophrenia. A total of 170 outpatients with schizophrenia were included in this study. All patients were evaluated with the Scale to Assess Unawareness of Mental Disorder (SUMD), Positive and Negative Syndrome Scale (PANSS) and Personal and Social Performance Scale (PSP). Patients with impaired insight and patients with unimpaired insight were compared for PSP score through independent samples t test. Pearson's correlation analysis was used to determine the correlations between study variables. Multiple stepwise linear regression analysis was used in order to determine the variables that predict social performance. The PSP score of patients with impaired insight was significantly lower than that of patients with unimpaired insight. There were significant correlations between insight dimensions and PSP score. PANSS negative scale score, awareness of achieved effects of medication and awareness of anhedonia/asociality were significant predictors of social performance. Insight has a significant impact on social functioning in schizophrenia, and some, but not all, insight dimensions have direct impact on social performance, independent of their association with symptoms. © The Author(s) 2014.

Socio-demographic diversity and unexplained variation in death rates among the most deprived parliamentary constituencies in Britain.

PubMed

Tunstall, H; Mitchell, R; Gibbs, J; Platt, S; Dorling, D

2012-06-01

There is considerable unexplained variation in death rates between deprived areas of Britain. This analysis assesses the degree of variation in socio-demographic factors among deprivation deciles and how variables associated with deaths differ among the most deprived areas. Death rates 1996-2001, Carstairs' 2001 deprivation score and indicators, population density, black and minority ethnic group (BME) and population change 1971-2001 were calculated for 641 parliamentary constituencies in Britain. Constituencies were grouped into Carstairs' deciles. We assessed standard errors of all variables by decile and the relationship between death rates and socio-demographic variables with Pearson's correlations and linear regression by decile and for all constituencies combined. Standard errors in death rates and most socio-demographic variables were greatest for the most deprived decile. Death rates among all constituencies were positively correlated with Carstairs' score and indicators, density and BME, but for the most deprived decile, there was no association with Carstairs and a negative correlation with overcrowding, density and BME. For the most deprived decile multivariate models containing population density, BME and change had substantially higher R(2). Understanding variations in death rates between deprived areas requires greater consideration of their socio-demographic diversity including their population density, ethnicity and migration.

Predicting Power Output of Upper Body using the OMNI-RES Scale.

PubMed

Bautista, Iker J; Chirosa, Ignacio J; Tamayo, Ignacio Martín; González, Andrés; Robinson, Joseph E; Chirosa, Luis J; Robertson, Robert J

2014-12-09

The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI-RES scale values of different loads of the bench press exercise. Sixty males (age 23.61 2.81 year; body height 176.29 6.73 cm; body mass 73.28 4.75 kg) voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM) in the bench press exercise. A linear regression analysis produced a strong correlation (r = -0.94) between rating of perceived exertion (RPE) and mean bar velocity (Velmean). The Pearson correlation analysis between real power output (PotReal) and estimated power (PotEst) showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI-RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone.

Predicting Power Output of Upper Body using the OMNI-RES Scale

PubMed Central

Bautista, Iker J.; Chirosa, Ignacio J.; Tamayo, Ignacio Martín; González, Andrés; Robinson, Joseph E.; Chirosa, Luis J.; Robertson, Robert J.

2014-01-01

The main aim of this study was to determine the optimal training zone for maximum power output. This was to be achieved through estimating mean bar velocity of the concentric phase of a bench press using a prediction equation. The values for the prediction equation would be obtained using OMNI–RES scale values of different loads of the bench press exercise. Sixty males (age 23.61 2.81 year; body height 176.29 6.73 cm; body mass 73.28 4.75 kg) voluntarily participated in the study and were tested using an incremental protocol on a Smith machine to determine one repetition maximum (1RM) in the bench press exercise. A linear regression analysis produced a strong correlation (r = −0.94) between rating of perceived exertion (RPE) and mean bar velocity (Velmean). The Pearson correlation analysis between real power output (PotReal) and estimated power (PotEst) showed a strong correlation coefficient of r = 0.77, significant at a level of p = 0.01. Therefore, the OMNI–RES scale can be used to predict Velmean in the bench press exercise to control the intensity of the exercise. The positive relationship between PotReal and PotEst allowed for the identification of a maximum power-training zone. PMID:25713677

The Interrelations among the Perception of Parental Styles and Psychological Well-Being in Adolescence: A Longitudinal Study.

PubMed

Shahimi, Farnaz; Heaven, Patrick; Ciarrochi, Joseph

2013-01-01

This longitudinal study aims to examine the relationships between the perception of parental style, hope, self-esteem and Eysenck's psychoticism dimension throughout the span of four years. The sample was composed of 884 students from the Wollongong Youth Study, which commenced when students entered high school. During the course of the 4 years of the study, each participant completed the test booklets each time data was collected. Data was analyzed using one way ANOVA, Post-hoc test, Repeated Measurement, Pearson and Partial Correlation and General Linear Model in order to provide the aims of the study. The mean score of hope and self-esteem among adolescents from authoritative parents were higher from permissive and authoritarian families while the hope with a permissive perception were lower than those with authoritarian, and self-esteem was lower in the authoritarian group compared to the permissive group. Children with a permissive perception reported higher psychoticism compared to the two other. Significant correlations were found between authoritative perception and hope, self-esteem and psychoticism. Finally, hope, self-esteem and psychoticism showed a significant inter correlation in all of the parental styles. Adolescents with the perception of each kind of parental style showed significant between group differences in psychological well-being throughout the four years of the study.

Association of serum uric acid with high-sensitivity C-reactive protein in postmenopausal women.

PubMed

Raeisi, A; Ostovar, A; Vahdat, K; Rezaei, P; Darabi, H; Moshtaghi, D; Nabipour, I

2017-02-01

To explore the independent correlation between serum uric acid and low-grade inflammation (measured by high-sensitivity C-reactive protein, hs-CRP) in postmenopausal women. A total of 378 healthy Iranian postmenopausal women were randomly selected in a population-based study. Circulating hs-CRP levels were measured by highly specific enzyme-linked immunosorbent assay method and an enzymatic calorimetric method was used to measure serum levels of uric acid. Pearson correlation coefficient, multiple linear regression and logistic regression models were used to analyze the association between uric acid and hs-CRP levels. A statistically significant correlation was seen between serum levels of uric acid and log-transformed circulating hs-CRP (r = 0.25, p < 0.001). After adjustment for age and cardiovascular risk factors (according to NCEP ATP III criteria), circulating hs-CRP levels were significantly associated with serum uric acid levels (β = 0.20, p < 0.001). After adjustment for age and cardiovascular risk factors, hs-CRP levels ≥3 mg/l were significantly associated with higher uric acid levels (odds ratio =1.52, 95% confidence interval 1.18-1.96). Higher serum uric acid levels were positively and independently associated with circulating hs-CRP in healthy postmenopausal women.

Concentrated Animal Feeding Operations, Row Crops and their Relationship to Nitrate in Eastern Iowa Rivers

PubMed Central

Weldon, Mark B.; Hornbuckle, Keri C.

2009-01-01

Concentrated animal feeding operations (CAFO) and fertilizer application to row crops may contribute to poor water quality in surface waters. To test this hypothesis, we evaluated nutrient concentrations and fluxes in four Eastern Iowa watersheds sampled between 1996-2004. We found that these watersheds contribute nearly 10% of annual nitrate flux entering the Gulf of Mexico, while representing only 1.5% of the contributing drainage basin. Mass budget analysis shows stream flow to be a major loss of nitrogen (18% of total N output), second only to crop harvest (63%). The major watershed inputs of nitrogen include applied fertilizer for corn (54% of total N input) and nitrogen fixation by soybeans (26%). Despite the relatively small input from animal manure (~5%), the results of spatial analysis indicate that row crop and CAFO densities are significantly and independently correlated to higher nitrate concentration in streams. Pearson correlation coefficients of 0.59 and 0.89 were found between nitrate concentration and row crop and CAFO density, respectively. Multiple linear regression analysis produced a correlation for nitrate concentration with an R2 value of 85%. High spatial density of row crops and CAFOs are linked to the highest river nitrate concentrations (up to 15 mg/l normalized over five years). PMID:16749677

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).

The role of spurious correlation in the development of a komatiite alteration model

NASA Astrophysics Data System (ADS)

Butler, John C.

1986-11-01

Procedures for detecting alterations in komatiites are described. The research of Pearson (1897) on spurious correlation and of Chayes (1949, 1971) on ratio correlation is reviewed. The equations for the ratio correlation procedure are provided. The ratio correlation procedure is applied to the komatiites from Gorgona Island and the Barberton suite. Plots of the molecular proportion ratios of (FeO + MgO)/TiO2 versus SiO2/TiO2, and correlation coefficients for the komatiites are presented and analyzed.

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.

Spectral properties of the nucleus of short-period comets

NASA Astrophysics Data System (ADS)

Toth, I.; Lamy, P. L.

2000-10-01

Comets, Edgeworth-Kuiper-Belt Objects (EKBOs), Centaurs and low albedo asteroids contain a considerable amount of information regarding some of the primordial processes that governed the formation of the early Solar System planetesimals. Opportunities to determine the colors of cometary nuclei are rare and relevant ground-based observations are difficult to perform. Color diversities and similarities between different types of small bodies have already been considered ([1] and references therein). We pursue this analysis further by introducing new BVRI colors obtained from our survey of cometary nuclei with the Hubble Space Telescope [2] as well as recent data obtained on EKBOs. We present preliminary results on the distribution of the BVRI colors (histograms, two-color diagrams) and possible relationships between the colors and orbital elements as well as the determined body sizes. The mean colors of the selected sample of the short-period (s-p) comets are: < (B-V) > = 0.91, < (V-R) > = 0.52, and < (V-I) > = 0.84. Pearson's linear correlation analysis of the (B-V) versus (V-R) and (V-R) versus (V-I) colors show significant correlations for the EKBOs+Centaurs sample while the s-p sample seems to be uncorrelated, with a few outliers. The linear regression lines of the EKBOs+Centaurs sample crosses through the sample of the s-p comets. There are no correlations of the colors versus perihelion distances, effective radii and perihelion distances as well as the (a,sin(i)) diagrams. This work was supported by grants from CNRS and CNES, France and partially by the the Hungarian Research Foundation OTKA T025049. [1] Luu, J., 1993. Icarus 104, 138. [2] Lamy, P.L. et al., this conference

Holocene monsoon variability as resolved in small complex networks from palaeodata

NASA Astrophysics Data System (ADS)

Rehfeld, K.; Marwan, N.; Breitenbach, S.; Kurths, J.

2012-04-01

To understand the impacts of Holocene precipitation and/or temperature changes in the spatially extensive and complex region of Asia, it is promising to combine the information from palaeo archives, such as e.g. stalagmites, tree rings and marine sediment records from India and China. To this end, complex networks present a powerful and increasingly popular tool for the description and analysis of interactions within complex spatially extended systems in the geosciences and therefore appear to be predestined for this task. Such a network is typically constructed by thresholding a similarity matrix which in turn is based on a set of time series representing the (Earth) system dynamics at different locations. Looking into the pre-instrumental past, information about the system's processes and thus its state is available only through the reconstructed time series which -- most often -- are irregularly sampled in time and space. Interpolation techniques are often used for signal reconstruction, but they introduce additional errors, especially when records have large gaps. We have recently developed and extensively tested methods to quantify linear (Pearson correlation) and non-linear (mutual information) similarity in presence of heterogeneous and irregular sampling. To illustrate our approach we derive small networks from significantly correlated, linked, time series which are supposed to capture the underlying Asian Monsoon dynamics. We assess and discuss whether and where links and directionalities in these networks from irregularly sampled time series can be soundly detected. Finally, we investigate the role of the Northern Hemispheric temperature with respect to the correlation patterns and find that those derived from warm phases (e.g. Medieval Warm Period) are significantly different from patterns found in cold phases (e.g. Little Ice Age).

The Diesel Exhaust in Miners Study: III. Interrelations between respirable elemental carbon and gaseous and particulate components of diesel exhaust derived from area sampling in underground non-metal mining facilities.

PubMed

Vermeulen, Roel; Coble, Joseph B; Yereb, Daniel; Lubin, Jay H; Blair, Aaron; Portengen, Lützen; Stewart, Patricia A; Attfield, Michael; Silverman, Debra T

2010-10-01

Diesel exhaust (DE) has been implicated as a potential lung carcinogen. However, the exact components of DE that might be involved have not been clearly identified. In the past, nitrogen oxides (NO(x)) and carbon oxides (CO(x)) were measured most frequently to estimate DE, but since the 1990s, the most commonly accepted surrogate for DE has been elemental carbon (EC). We developed quantitative estimates of historical exposure levels of respirable elemental carbon (REC) for an epidemiologic study of mortality, particularly lung cancer, among diesel-exposed miners by back-extrapolating 1998-2001 REC exposure levels using historical measurements of carbon monoxide (CO). The choice of CO was based on the availability of historical measurement data. Here, we evaluated the relationship of REC with CO and other current and historical components of DE from side-by-side area measurements taken in underground operations of seven non-metal mining facilities. The Pearson correlation coefficient of the natural log-transformed (Ln)REC measurements with the Ln(CO) measurements was 0.4. The correlation of REC with the other gaseous, organic carbon (OC), and particulate measurements ranged from 0.3 to 0.8. Factor analyses indicated that the gaseous components, including CO, together with REC, loaded most strongly on a presumed 'Diesel exhaust' factor, while the OC and particulate agents loaded predominantly on other factors. In addition, the relationship between Ln(REC) and Ln(CO) was approximately linear over a wide range of REC concentrations. The fact that CO correlated with REC, loaded on the same factor, and increased linearly in log-log space supported the use of CO in estimating historical exposure levels to DE.

Depression is a predictor for balance in people with multiple sclerosis.

PubMed

Alghwiri, Alia A; Khalil, Hanan; Al-Sharman, Alham; El-Salem, Khalid

2018-05-26

Balance impairments are common and multifactorial among people with multiple sclerosis (MS). Depression is the most common psychological disorder in MS population and is strongly correlated with MS disease. Depression might be one of the factors that contribute to balance deficits in this population. However, the relationship between depression and balance impairments has not been explored in people with MS. To investigate the association between depression and balance impairments in people with MS. Cross sectional design was used in patients with MS. The Activities-specific Balance Confidence scale (ABC) and Berg Balance Scale (BBS) was used to assess balance. Beck Depression Inventory (BDI-II) was used to quantify depression and Kurtizki Expanded Disability Status Scale (EDSS) was utilized for the evaluation of MS disability severity. Pearson correlation coefficient was used to examine the association between depression and balance measurements. Multiple linear stepwise regressions were also conducted to find out if depression is a potential predictor for balance deficits. Seventy-five individuals with MS (Female = 69%) with a mean age (SD) of 38.8 (10) and a mean (SD) EDSS score of 3.0 (1.4) were recruited in this study. Depression was present in 53% of the patients. Depression was significantly correlated with balance measurements and EDSS. However, multiple linear stepwise regressions found that only depression and age significantly predict balance. Depression and balance were found frequent and associated in people with MS. Importantly depression was a significant predictor for balance impairments in individuals with MS. Balance rehabilitation may be hindered by depression. Therefore, depression should be evaluated and treated properly in individuals with MS. Copyright © 2018 Elsevier B.V. All rights reserved.

Leniency and halo effects in marking undergraduate short research projects.

PubMed

McKinstry, Brian H; Cameron, Helen S; Elton, Robert A; Riley, Simon C

2004-11-29

Supervisors are often involved in the assessment of projects they have supervised themselves. Previous research suggests that detailed marking sheets may alleviate leniency and halo effects. We set out to determine if, despite using such a marking schedule, leniency and halo effects were evident in the supervisors' marking of undergraduate short research projects (special study modules (SSM)). Review of grades awarded by supervisors, second markers and control markers to the written reports of 4th year medical students who had participated in an SSM during two full academic years (n = 399). Paired t-tests were used to compare mean marks, Pearson correlation to look at agreement between marks and multiple linear regression to test the prediction of one mark from several others adjusted for one another. There was a highly significant difference of approximately half a grade between supervisors and second markers with supervisors marking higher. (t = 3.12, p < 0.01, difference in grade score = 0.42, 95% CI for mean difference 0.18-0.80). There was a high correlation between the two marks awarded for performance of the project and the written report by the supervisor (r = 0.75), but a low-modest correlation between supervisor and second marker (r = 0.28). Linear regression analysis of the influence of the supervisors' mark for performance on their mark for the report gave a non-significant result. This suggests a leniency effect but no halo effect. This study shows that with the use of structured marking sheet for assessment of undergraduate medical students, supervisors marks are not associated with a halo effect, but leniency does occur. As supervisor assessment is becoming more common in both under graduate and postgraduate teaching new ways to improve objectivity in marking and to address the leniency of supervisors should be sought.

The relationship between emotional intelligence and job stress in the faculty of medicine in Isfahan University of Medical Sciences

PubMed Central

YAMANI, NIKOO; SHAHABI, MARYAM; HAGHANI, FARIBA

2014-01-01

Introduction: health care professionals especially clinicians, undergo lots of job stress (JS). Emotional intelligence (EI) is among the variables that appear to be associated with stress. It is also included among the ways adopted by the individuals in order to resist JS in the workplace. Thus, this study aims to investigate the relationship between EI and JS in the faculty members of Isfahan University of Medical Sciences (IUMS). Methods: This was a correlational study performed on 202 faculty members of IUMS. The data was gathered through two valid and reliable questionnaires (Bradberry EI questionnaire and JS questionnaire), being analyzed by SPSS software using descriptive statistics, Pearson correlation coefficient, t-test, analysis of variance (ANOVA) and linear regression analysis (α=0.05). Results: 142 individuals (70.30%) filled out the questionnaires. 75% of the respondents were male and 98% were married. There was an inverse correlation between the total score of EI and the level of JS (r=-0.235, p=0.005). Moreover, among the factors of EI, self-awareness and self-management scores had significant inverse relationship with the level of JS. Linear regression analysis showed that the EI factors explained approximately 7% of the variance of JS levels of the teachers. Conclusions: Individuals with high EI have less JS. Since the EI can be taught, it can be expected that the JS of faculty members can be reduced through training them on emotional intelligence. Therefore, it is recommended that short-term training courses be scheduled and designed based on the concepts of EI for teachers, particularly clinicians. PMID:25512914

Evaluation of Relationship between Trunk Muscle Endurance and Static Balance in Male Students

PubMed Central

Barati, Amirhossein; SafarCherati, Afsaneh; Aghayari, Azar; Azizi, Faeze; Abbasi, Hamed

2013-01-01

Purpose Fatigue of trunk muscle contributes to spinal instability over strenuous and prolonged physical tasks and therefore may lead to injury, however from a performance perspective, relation between endurance efficient core muscles and optimal balance control has not been well-known. The purpose of this study was to examine the relationship of trunk muscle endurance and static balance. Methods Fifty male students inhabitant of Tehran university dormitory (age 23.9±2.4, height 173.0±4.5 weight 70.7±6.3) took part in the study. Trunk muscle endurance was assessed using Sørensen test of trunk extensor endurance, trunk flexor endurance test, side bridge endurance test and static balance was measured using single-limb stance test. A multiple linear regression analysis was applied to test if the trunk muscle endurance measures significantly predicted the static balance. Results There were positive correlations between static balance level and trunk flexor, extensor and lateral endurance measures (Pearson correlation test, r=0.80 and P<0.001; r=0.71 and P<0.001; r=0.84 and P<0.001, respectively). According to multiple regression analysis for variables predicting static balance, the linear combination of trunk muscle endurance measures was significantly related to the static balance (F (3,46) = 66.60, P<0.001). Endurance of trunk flexor, extensor and lateral muscles were significantly associated with the static balance level. The regression model which included these factors had the sample multiple correlation coefficient of 0.902, indicating that approximately 81% of the variance of the static balance is explained by the model. Conclusion There is a significant relationship between trunk muscle endurance and static balance. PMID:24800004

Stature estimation from the lengths of the growing foot-a study on North Indian adolescents.

PubMed

Krishan, Kewal; Kanchan, Tanuj; Passi, Neelam; DiMaggio, John A

2012-12-01

Stature estimation is considered as one of the basic parameters of the investigation process in unknown and commingled human remains in medico-legal case work. Race, age and sex are the other parameters which help in this process. Stature estimation is of the utmost importance as it completes the biological profile of a person along with the other three parameters of identification. The present research is intended to formulate standards for stature estimation from foot dimensions in adolescent males from North India and study the pattern of foot growth during the growing years. 154 male adolescents from the Northern part of India were included in the study. Besides stature, five anthropometric measurements that included the length of the foot from each toe (T1, T2, T3, T4, and T5 respectively) to pternion were measured on each foot. The data was analyzed statistically using Student's t-test, Pearson's correlation, linear and multiple regression analysis for estimation of stature and growth of foot during ages 13-18 years. Correlation coefficients between stature and all the foot measurements were found to be highly significant and positively correlated. Linear regression models and multiple regression models (with age as a co-variable) were derived for estimation of stature from the different measurements of the foot. Multiple regression models (with age as a co-variable) estimate stature with greater accuracy than the regression models for 13-18 years age group. The study shows the growth pattern of feet in North Indian adolescents and indicates that anthropometric measurements of the foot and its segments are valuable in estimation of stature in growing individuals of that population. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Diesel Exhaust in Miners Study: III. Interrelations between Respirable Elemental Carbon and Gaseous and Particulate Components of Diesel Exhaust derived from Area Sampling in Underground Non-metal Mining Facilities

PubMed Central

Vermeulen, Roel; Coble, Joseph B.; Yereb, Daniel; Lubin, Jay H.; Blair, Aaron; Portengen, Lützen; Stewart, Patricia A.; Attfield, Michael; Silverman, Debra T.

2010-01-01

Diesel exhaust (DE) has been implicated as a potential lung carcinogen. However, the exact components of DE that might be involved have not been clearly identified. In the past, nitrogen oxides (NOx) and carbon oxides (COx) were measured most frequently to estimate DE, but since the 1990s, the most commonly accepted surrogate for DE has been elemental carbon (EC). We developed quantitative estimates of historical exposure levels of respirable elemental carbon (REC) for an epidemiologic study of mortality, particularly lung cancer, among diesel-exposed miners by back-extrapolating 1998–2001 REC exposure levels using historical measurements of carbon monoxide (CO). The choice of CO was based on the availability of historical measurement data. Here, we evaluated the relationship of REC with CO and other current and historical components of DE from side-by-side area measurements taken in underground operations of seven non-metal mining facilities. The Pearson correlation coefficient of the natural log-transformed (Ln)REC measurements with the Ln(CO) measurements was 0.4. The correlation of REC with the other gaseous, organic carbon (OC), and particulate measurements ranged from 0.3 to 0.8. Factor analyses indicated that the gaseous components, including CO, together with REC, loaded most strongly on a presumed ‘Diesel exhaust’ factor, while the OC and particulate agents loaded predominantly on other factors. In addition, the relationship between Ln(REC) and Ln(CO) was approximately linear over a wide range of REC concentrations. The fact that CO correlated with REC, loaded on the same factor, and increased linearly in log–log space supported the use of CO in estimating historical exposure levels to DE. PMID:20876234

Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry

PubMed Central

Huang, Mingna; Hu, Yun; Yu, Jinfeng; Sun, Jicheng; Ming, Ye

2017-01-01

Objective Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar. PMID:28861389

Predictive Regression Equations of Flowmetric and Spirometric Peak Expiratory Flow in Healthy Moroccan Children.

PubMed

Bouti, Khalid; Benamor, Jouda; Bourkadi, Jamal Eddine

2017-08-01

Peak Expiratory Flow (PEF) has never been characterised among healthy Moroccan school children. To study the relationship between PEF and anthropometric parameters (sex, age, height and weight) in healthy Moroccan school children, to establish predictive equations of PEF; and to compare flowmetric and spirometric PEF with Forced Expiratory Volume in 1 second (FEV1). This cross-sectional study was conducted between April, 2016 and May, 2016. It involved 222 (122 boys and 100 girls) healthy school children living in Ksar el-Kebir, Morocco. We used mobile equipments for realisation of spirometry and peak expiratory flow measurements. SPSS (Version 22.0) was used to calculate Student's t-test, Pearson's correlation coefficient and linear regression. Significant linear correlation was seen between PEF, age and height in boys and girls. The equation for prediction of flowmetric PEF in boys was calculated as 'F-PEF = -187+ 24.4 Age + 1.61 Height' (p-value<0.001, r=0.86), and for girls as 'F-PEF = -151 + 17Age + 1.59Height' (p-value<0.001, r=0.86). The equation for prediction of spirometric PEF in boys was calculated as 'S-PEF = -199+ 9.8Age + 2.67Height' (p-value<0.05, r=0.77), and for girls as 'S-PEF = -181 + 8.5Age + 2.5Height' (p-value<0.001, r=0.83). The boys had higher values than the girls. The performance of the Mini Wright Peak Flow Meter was lower than that of a spirometer. Our study established PEF predictive equations in Moroccan children. Our results appeared to be reliable, as evident by the high correlation coefficient in this sample. PEF can be an alternative of FEV1 in centers without spirometry.

Can Preoperative Psychological Assessment Predict Outcomes After Temporomandibular Joint Arthroscopy?

PubMed

Bouloux, Gary F; Zerweck, Ashley G; Celano, Marianne; Dai, Tian; Easley, Kirk A

2015-11-01

Psychological assessment has been used successfully to predict patient outcomes after cardiothoracic and bariatric surgery. The purpose of this study was to determine whether preoperative psychological assessment could be used to predict patient outcomes after temporomandibular joint arthroscopy. Consecutive patients with temporomandibular dysfunction (TMD) who could benefit from arthroscopy were enrolled in a prospective cohort study. All patients completed the Millon Behavior Medicine Diagnostic survey before surgery. The primary predictor variable was the preoperative psychological scores. The primary outcome variable was the difference in pain between the pre- and postoperative periods. The Spearman rank correlation coefficient and the Pearson product-moment correlation were used to determine the association between psychological factors and change in pain. Univariable and multivariable analyses were performed using a mixed-effects linear model and multiple linear regression. A P value of .05 was considered significant. Eighty-six patients were enrolled in the study. Seventy-five patients completed the study and were included in the final analyses. The mean change in visual analog scale (VAS) pain score 1 month after arthroscopy was -15.4 points (95% confidence interval, -6.0 to -24.7; P < .001). Jaw function also improved after surgery (P < .001). No association between change in VAS pain score and each of the 5 preoperative psychological factors was identified with univariable correlation analyses. Multivariable analyses identified that a greater pain decrease was associated with a longer duration of preoperative symptoms (P = .054) and lower chronic anxiety (P = .064). This study has identified a weak association between chronic anxiety and the magnitude of pain decrease after arthroscopy for TMD. Further studies are needed to clarify the role of chronic anxiety in the outcome after surgical procedures for the treatment of TMD. Copyright © 2015. Published by Elsevier Inc.

The extent of using mobility assistive devices can partly explain fatigue among persons with late effects of polio - a retrospective registry study in Sweden.

PubMed

Santos Tavares Silva, I; Sunnerhagen, K S; Willén, C; Ottenvall Hammar, I

2016-11-18

Fatigue is reported as one of the most disabling symptoms and is common among persons living with late effects of polio. Although fatigue has been studied in the context of people living with late effects of polio, there is a lack of knowledge concerning the association of fatigue and variables of importance for participation in daily life. Therefore, the aim of this study was to explore possible factors associated with fatigue among persons with late effects of polio in Sweden. This retrospective registry study consisted of 89 persons with late effects of polio living in Sweden. Fatigue was measured with the Multidimensional Fatigue Inventory (MFI-20) scale, Swedish version. Pearson's correlation coefficient was used to analyse the correlation between the factors and fatigue, and a multiple linear regression was carried out to explore factors for fatigue. Fatigue statistically significantly correlated with age (r = 0.234, p < 0.05) and the use of mobility assistive devices (r = 0.255, p < 0.05). The multiple linear regression model showed that the factors age (β = 0.304, p < 0.019) and mobility assistive devices (β = 0.262, p < 0.017) were associated with fatigue among persons living with late effects of polio, and the model partly explained 14% of the variation of fatigue. Fatigue could partly be explained by the extent of using mobility assistive devices and age. Healthcare professionals should provide and demonstrate the importance of assistive devices to ensure management of fatigue in persons living with late effects of polio.

Correlates of Dietary Adherence and Maladaptive Eating Patterns Following Roux-en-Y Bariatric Surgery.

PubMed

Adler, Sarah; Fowler, Natasha; Robinson, Athena Hagler; Salcido, Lianne; Darcy, Alison; Toyama, Hannah; Safer, Debra Lynn

2018-04-01

Self-reported poor dietary adherence following bariatric surgery is associated with less successful weight loss outcomes. Poor dietary adherence is a global construct lacking specificity regarding its underlying, clinically targetable, maladaptive eating behaviors. Comprehensive online survey data were obtained from a sample of 274 adults who underwent Roux-en-Y surgery in the prior 1-12 years. Correlations between dietary adherence and six eating-related behaviors were calculated, with the frequency of each behavior reported on a 7-point scale. Linear regression modeling was applied. All six maladaptive eating behaviors were highly correlated with dietary adherence (Pearson's r > 0.5): grazing (r = - 0.565), mindless eating (r = - 0.572), loss of control eating (r = - 0.517), eating "more than is best" after dinner (r = - 0.518), eating foods off of one's plan (r = - 0.557), and "when I eat something off-plan, I feel like I have blown it and I give up and eat more" (r = - 0.574). The estimated regression coefficients in the linear model was statistically significant, [F(5, 261) = 60.006, p < 0.001] and accounted for approximately 54% of the variance of global dietary adherence (R 2  = 0.535, adjusted R 2  = 0.526). Six maladaptive eating behaviors accounted for a highly significant portion of post-Roux-en-Y patients' poor self- reported dietary adherence. Prospective studies are needed to investigate the relationship between targetable maladaptive eating behaviors and bariatric surgery outcomes.

Correlation between cystatin C-based formulas, Schwartz formula and urinary creatinine clearance for glomerular filtration rate estimation in children with kidney disease.

PubMed

Safaei-Asl, Afshin; Enshaei, Mercede; Heydarzadeh, Abtin; Maleknejad, Shohreh

2016-01-01

Assessment of glomerular filtration rate (GFR) is an important tool for monitoring renal function. Regarding to limitations in available methods, we intended to calculate GFR by cystatin C (Cys C) based formulas and determine correlation rate of them with current methods. We studied 72 children (38 boys and 34 girls) with renal disorders. The 24 hour urinary creatinine (Cr) clearance was the gold standard method. GFR was measured with Schwartz formula and Cys C-based formulas (Grubb, Hoek, Larsson and Simple). Then correlation rates of these formulas were determined. Using Pearson correlation coefficient, a significant positive correlation between all formulas and the standard method was seen (R(2) for Schwartz, Hoek, Larsson, Grubb and Simple formula was 0.639, 0.722, 0.705, 0.712, 0.722, respectively) (P<0.001). Cys C-based formulas could predict the variance of standard method results with high power. These formulas had correlation with Schwarz formula by R(2) 0.62-0.65 (intermediate correlation). Using linear regression and constant (y-intercept), it revealed that Larsson, Hoek and Grubb formulas can estimate GFR amounts with no statistical difference compared with standard method; but Schwartz and Simple formulas overestimate GFR. This study shows that Cys C-based formulas have strong relationship with 24 hour urinary Cr clearance. Hence, they can determine GFR in children with kidney injury, easier and with enough accuracy. It helps the physician to diagnosis of renal disease in early stages and improves the prognosis.

Association of pituitary adenylate cyclase-activating polypeptide with cognitive decline in mild cognitive impairment due to Alzheimer disease.

PubMed

Han, Pengcheng; Caselli, Richard J; Baxter, Leslie; Serrano, Geidy; Yin, Junxiang; Beach, Thomas G; Reiman, Eric M; Shi, Jiong

2015-03-01

There is a deficit of pituitary adenylate cyclase-activating polypeptide (PACAP) in patients with neuropathologically confirmed Alzheimer dementia. However, whether this deficit is associated with the earlier stages of Alzheimer disease (AD) is unknown. This study was conducted to clarify the association between PACAP biomarkers and preclinical, mild cognitive impairment (MCI), and dementia stages of AD in postmortem brain tissue. To examine PACAP and PACAP receptor levels in postmortem brain tissues and cerebrospinal fluid from cognitively and neuropathologically normal control individuals, patients with MCI due to AD (MCI-AD), and individuals with AD; analyze the relationship between PACAP, cognitive, and pathologic features; and propose a model to assess these relationships. We measured PACAP and its receptor (PAC1) levels using enzyme-linked immunoassay. A total of 35 cases were included. All the brain tissue and cerebrospinal fluid samples were selected from Banner Sun Health Research Institute Brain and Body Donation Program. All cognitive test results were in record with the Arizona Alzheimer's Consortium. A comparison of PACAP and PAC1 levels among the healthy controls, MCI-AD, and AD dementia groups, as well as a systematic correlation analysis between PACAP level, cognitive performance, and pathologic severity. The PACAP levels in cerebrospinal fluid, the superior frontal gyrus, and the middle temporal gyrus were inversely related to dementia severity. The PACAP levels in cerebrospinal fluid correlated with the Mattis Dementia Rating Scale score (Pearson r = 0.50; P = .03) and inversely correlated with total amyloid plaques (Pearson r = -0.48; P < .01) and tangles (Pearson r = -0.55; P = .01) in the brain. The PACAP in the superior frontal gyrus and middle temporal gyrus correlated with the Stroop Color-Word Interference Test (Pearson r = 0.58; P < .01) and the Auditory Verbal Learning Test-Total Learning (Pearson r = 0.33; P = .02), respectively. The PACAP in the primary visual cortex did not correlate with the Judgment of Line orientation test (P = .14). Furthermore, the PAC1 level in the superior frontal gyrus showed an upregulation in MCI-AD but not in AD. The pharmacodynamic model of the PACAP-PAC1 interaction best predicted cognitive function in the superior frontal gyrus, but it was less predictive in the middle temporal gyrus and failed to be predictive in the primary visual cortex. Deficits in PACAP are associated with clinical severity in the MCI and dementia stages of AD. Additional studies are needed to clarify the role of PACAP deficits in the predisposition to, pathogenesis of, and treatment of AD.

Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema.

PubMed

Forooghian, Farzin; Stetson, Paul F; Meyer, Scott A; Chew, Emily Y; Wong, Wai T; Cukras, Catherine; Meyerle, Catherine B; Ferris, Frederick L

2010-01-01

The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity. Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity. Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81. Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS measurements was less than that of macular thickness measurements, the stronger correlation of PROS length with visual acuity suggests that the PROS measures may be more directly related to visual function. Photoreceptor outer segment length may be a useful physiologic outcome measure, both clinically and as a direct assessment of treatment effects.

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.

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.

Correcting Four Similar Correlational Measures for Attenuation Due to Errors of Measurement in the Dependent Variable: Eta, Epsilon, Omega, and Intraclass r.

ERIC Educational Resources Information Center

Stanley, Julian C.; Livingston, Samuel A.

Besides the ubiquitous Pearson product-moment r, there are a number of other measures of relationship that are attenuated by errors of measurement and for which the relationship between true measures can be estimated. Among these are the correlation ratio (eta squared), Kelley's unbiased correlation ratio (epsilon squared), Hays' omega squared,…

Ethnic differences in association of high body mass index with early onset of Type 1 diabetes - Arab ethnicity as case study.

PubMed

Channanath, Arshad M; Elkum, Naser; Al-Abdulrazzaq, Dalia; Tuomilehto, Jaakko; Shaltout, Azza; Thanaraj, Thangavel Alphonse

2017-01-01

The "accelerator hypothesis" predicts early onset of Type 1 diabetes (T1D) in heavier children. Studies testing direction of correlation between body mass index (BMI) and age at onset of T1D in different continental populations have reported differing results-inverse, direct, and neutral. Evaluating the correlation in diverse ethnic populations is required to generalize the accelerator hypothesis. The study cohort comprised 474 Kuwaiti children of Arab ethnicity diagnosed with T1D at age 6 to 18 years during 2011-2013. Age- and sex-adjusted BMI z-scores were calculated by comparing the BMI measured at diagnosis with Kuwaiti pediatric population reference data recorded during comparable time-period. Multiple linear regression and Pearson correlation analyses were performed. BMI z-score was seen inversely associated with onset age (r,-0.28; p-value<0.001). Children with BMI z-score>0 (i.e. BMI >national average) showed a stronger correlation (r,-0.38; p-value<0.001) than those with BMI z-score<0 (r,-0.19; p-value<0.001); the former group showed significantly lower mean onset age than the latter group (9.6±2.4 versus 10.5±2.7; p-value<0.001). Observed inverse correlation was consistent with that seen in Anglo-saxon, central european, caucasian, and white children while inconsistent with that seen in Indian, New Zealander, and Australian children. The accelerator hypothesis generalizes in Arab pediatric population from Kuwait.

Tmax Determined Using a Bayesian Estimation Deconvolution Algorithm Applied to Bolus Tracking Perfusion Imaging: A Digital Phantom Validation Study.

PubMed

Uwano, Ikuko; Sasaki, Makoto; Kudo, Kohsuke; Boutelier, Timothé; Kameda, Hiroyuki; Mori, Futoshi; Yamashita, Fumio

2017-01-10

The Bayesian estimation algorithm improves the precision of bolus tracking perfusion imaging. However, this algorithm cannot directly calculate Tmax, the time scale widely used to identify ischemic penumbra, because Tmax is a non-physiological, artificial index that reflects the tracer arrival delay (TD) and other parameters. We calculated Tmax from the TD and mean transit time (MTT) obtained by the Bayesian algorithm and determined its accuracy in comparison with Tmax obtained by singular value decomposition (SVD) algorithms. The TD and MTT maps were generated by the Bayesian algorithm applied to digital phantoms with time-concentration curves that reflected a range of values for various perfusion metrics using a global arterial input function. Tmax was calculated from the TD and MTT using constants obtained by a linear least-squares fit to Tmax obtained from the two SVD algorithms that showed the best benchmarks in a previous study. Correlations between the Tmax values obtained by the Bayesian and SVD methods were examined. The Bayesian algorithm yielded accurate TD and MTT values relative to the true values of the digital phantom. Tmax calculated from the TD and MTT values with the least-squares fit constants showed excellent correlation (Pearson's correlation coefficient = 0.99) and agreement (intraclass correlation coefficient = 0.99) with Tmax obtained from SVD algorithms. Quantitative analyses of Tmax values calculated from Bayesian-estimation algorithm-derived TD and MTT from a digital phantom correlated and agreed well with Tmax values determined using SVD algorithms.

The Role of Attachment, Travel Experiences and English Proficiency in International Students' Acculturative Stress and Depressive Symptoms

ERIC Educational Resources Information Center

Smiljanic, Iskra

2017-01-01

This study examined the relationship between attachment, travel experiences, and English proficiency and international students' acculturative stress and depressive symptoms. A total of 91 graduate international students completed online surveys. Pearson correlations showed that both attachment anxiety and avoidance were positively correlated with…

The Social Correlates of Lexical Borrowing in Spanish in New York City

ERIC Educational Resources Information Center

Varra, Rachel Marie

2013-01-01

This dissertation investigates lexical borrowing in Spanish in New York. English-origin lexical material was extracted from a stratified sample of 146 Spanish-speaking informants of different ages, national origins, classes, etc., living in New York City. ANOVAs and Pearson correlations determined whether lexical borrowing frequency and the type…

Interrater Reliability Estimators Commonly Used in Scoring Language Assessments: A Monte Carlo Investigation of Estimator Accuracy

ERIC Educational Resources Information Center

Morgan, Grant B.; Zhu, Min; Johnson, Robert L.; Hodge, Kari J.

2014-01-01

Common estimators of interrater reliability include Pearson product-moment correlation coefficients, Spearman rank-order correlations, and the generalizability coefficient. The purpose of this study was to examine the accuracy of estimators of interrater reliability when varying the true reliability, number of scale categories, and number of…

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…

Analysis of trichloroethylene removal and bacterial community function based on pH-adjusted in an upflow anaerobic sludge blanket reactor.

PubMed

Zhang, Ying; Hu, Miao; Li, Pengfei; Wang, Xin; Meng, Qingjuan

2015-11-01

The study reported the upflow anaerobic sludge blanket (UASB) reactor performance in treating wastewater containing trichloroethylene (TCE) and characterized variations of bacteria composition and structure by changing the pH from 6.0 to 8.0. A slightly acidic environment (pH < 7.0) had a greater impact on the TCE removal. Illumina pyrosequencing was applied to investigate the bacterial community changes in response to pH shifts. The results demonstrated that pH greatly influenced the dominance and presence of specific populations. The potential TCE degradation pathway in the UASB reactor was proposed. Importantly, the genus Dehalobacter which was capable of reductively dechlorinating TCE was detected, and it was not found at pH of 6.0, which presumably is the reason why the removal efficiency of TCE was the lowest (80.73 %). Through Pearson correlation analyses, the relative abundance of Dehalobacter positively correlated with TCE removal efficiency (R = 0.912). However, the relative abundance of Lactococcus negatively correlated with TCE removal efficiency according to the results from Pearson correlation analyses and redundancy analysis (RDA).

Relationship Between Visual Acuity and Retinal Thickness During Anti-Vascular Endothelial Growth Factor Therapy for Retinal Diseases.

PubMed

Ou, William C; Brown, David M; Payne, John F; Wykoff, Charles C

2017-08-01

To investigate the relationship between best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in eyes receiving ranibizumab for 3 common retinal diseases. Retrospective analysis of clinical trial data. Early Treatment Diabetic Retinopathy Study BCVA and spectral-domain optical coherence tomography-measured CRT of 387 eyes of 345 patients enrolled in 6 prospective clinical trials for management of neovascular age-related macular degeneration (AMD), diabetic macular edema (DME), and retinal vein occlusion (RVO) were evaluated by Pearson correlation and linear regression. At baseline, there was a small correlation between BCVA and CRT in pooled AMD trial data (r = -0.24). A medium correlation was identified in pooled DME trial data (r = -0.42). No correlation was found in pooled RVO trial data. At month 12, no correlation was found between changes from baseline in BCVA and CRT in pooled AMD trial data. Medium correlations were identified in both pooled DME (r = -0.45) and pooled RVO (r = -0.35) trial data at month 12. Changes in BCVA and CRT associated with edema recurrence upon transition from monthly to pro re nata (PRN) dosing were correlated in AMD (r = -0.27) and RVO (r = -0.72) trials, but not in DME trial data. DME demonstrated a convincing relationship between BCVA and CRT. Correlations appear to be more complex in AMD and RVO. At the inflection point between monthly and PRN dosing, when recurrence of edema is anticipated in many patients, CRT appears strongly correlated with loss of BCVA in RVO. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation analysis of respiratory signals by using parallel coordinate plots.

PubMed

Saatci, Esra

2018-01-01

The understanding of the bonds and the relationships between the respiratory signals, i.e. the airflow, the mouth pressure, the relative temperature and the relative humidity during breathing may provide the improvement on the measurement methods of respiratory mechanics and sensor designs or the exploration of the several possible applications in the analysis of respiratory disorders. Therefore, the main objective of this study was to propose a new combination of methods in order to determine the relationship between respiratory signals as a multidimensional data. In order to reveal the coupling between the processes two very different methods were used: the well-known statistical correlation analysis (i.e. Pearson's correlation and cross-correlation coefficient) and parallel coordinate plots (PCPs). Curve bundling with the number intersections for the correlation analysis, Least Mean Square Time Delay Estimator (LMS-TDE) for the point delay detection and visual metrics for the recognition of the visual structures were proposed and utilized in PCP. The number of intersections was increased when the correlation coefficient changed from high positive to high negative correlation between the respiratory signals, especially if whole breath was processed. LMS-TDE coefficients plotted in PCP indicated well-matched point delay results to the findings in the correlation analysis. Visual inspection of PCB by visual metrics showed range, dispersions, entropy comparisons and linear and sinusoidal-like relationships between the respiratory signals. It is demonstrated that the basic correlation analysis together with the parallel coordinate plots perceptually motivates the visual metrics in the display and thus can be considered as an aid to the user analysis by providing meaningful views of the data. Copyright © 2017 Elsevier B.V. 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

Validation of general job satisfaction in the Korean Labor and Income Panel Study.

PubMed

Park, Shin Goo; Hwang, Sang Hee

2017-01-01

The purpose of this study is to assess the validity and reliability of general job satisfaction (JS) in the Korean Labor and Income Panel Study (KLIPS). We used the data from the 17th wave (2014) of the nationwide KLIPS, which selected a representative panel sample of Korean households and individuals aged 15 or older residing in urban areas. We included in this study 7679 employed subjects (4529 males and 3150 females). The general JS instrument consisted of five items rated on a scale from 1 (strongly disagree) to 5 (strongly agree). The general JS reliability was assessed using the corrected item-total correlation and Cronbach's alpha coefficient. The validity of general JS was assessed using confirmatory factor analysis (CFA) and Pearson's correlation. The corrected item-total correlations ranged from 0.736 to 0.837. Therefore, no items were removed. Cronbach's alpha for general JS was 0.925, indicating excellent internal consistency. The CFA of the general JS model showed a good fit. Pearson's correlation coefficients for convergent validity showed moderate or strong correlations. The results obtained in our study confirm the validity and reliability of general JS.

[Current status of job burnout in clinical nurses in a grade A tertiary hospital and related influencing factors].

PubMed

Ye, L Y; Fan, C L; Wang, L G; Tao, T; Gao, W B; Li, Y H

2017-10-20

Objective: To investigate the current status of job burnout in clinical nurses in a grade A tertiary hospitalin Shaoxing,China and related influencing factors. Methods: In October 2016, the Nursing Burnout Scale (NBS)was used for the investigation of 304 clinical nurses in a grade A tertiary hospital.The contents of the investigation included general data(including age,education background,working years,marital status, frequency of night shifts,professional title, and way of employment), characteristics of working environment,burnout, personality characteristics,coping strategy,and psychosomatic symptoms.SPSS 18.0 was used to conduct Pearson correlation analysis of the scores of each dimension of NBS. A multivariate regression analysis was performed with the demographic features of clinical nurses as the independent variable and the scores of each dimension of NBS as the dependent variable. Results: Among the clinical nurses in this grade A tertiary hospital, the incidence rate of severe burnout was 74%.The Pearson correlation analysis showed that burnout,pessimistic personality,negative coping,and psychosomatic symptoms were positively correlated with working environment( r =0.530,0.316,0.116,and 0.502); pessimistic personality and psychosomatic symptoms were positively correlated with burnout( r =0.618 and 0.675); psychosomatic symptoms were positively correlated withpessimistic personality( r =0.540); negative coping was negatively correlated with pessimistic personality( r =-0.145).The multivariate linear regression analysis showed that department(Department of Internal Medicine or Department of Surgery, B =-0.364 and -0.428)and frequency of night shifts(<6 times/month and 6 - 10 times/month, B =0.199 and 0.256)were influencing factors for the score of working environment; department(Department of Internal Medicine or Department of Surgery, B =-0.350 and -0.360)was an influencing factor for the score of burnout; 1 - 3 working years( B =-0.238)was an influencing factor for the score of pessimistic personality; married state,1 - 3 working years,and department (Department of Internal Medicine or Department of Surgery)were influencing factors for the score of psychosomatic symptoms( B =0.263,-0.301,-0.322,and -0.391). Conclusion: There is a high incidence rate of job burnout among clinical nurses in this grade A tertiary hospital,which is associated with burnout,working environment, pessimistic personality,and psychosomatic symptoms.Marital status,working years,department,and frequency of night shifts are major influencing factors for job burnout.

Evaluating a measure of social health derived from two mental health recovery measures: the California Quality of Life (CA-QOL) and Mental Health Statistics Improvement Program Consumer Survey (MHSIP).

PubMed

Carlson, Jordan A; Sarkin, Andrew J; Levack, Ashley E; Sklar, Marisa; Tally, Steven R; Gilmer, Todd P; Groessl, Erik J

2011-08-01

Social health is important to measure when assessing outcomes in community mental health. Our objective was to validate social health scales using items from two broader commonly used measures that assess mental health outcomes. Participants were 609 adults receiving psychological treatment services. Items were identified from the California Quality of Life (CA-QOL) and Mental Health Statistics Improvement Program (MHSIP) outcome measures by their conceptual correspondence with social health and compared to the Social Functioning Questionnaire (SFQ) using correlational analyses. Pearson correlations for the identified CA-QOL and MSHIP items with the SFQ ranged from .42 to .62, and the identified scale scores produced Pearson correlation coefficients of .56, .70, and, .70 with the SFQ. Concurrent validity with social health was supported for the identified scales. The current inclusion of these assessment tools allows community mental health programs to include social health in their assessments.

Pearson's chi-square test and rank correlation inferences for clustered data.

PubMed

Shih, Joanna H; Fay, Michael P

2017-09-01

Pearson's chi-square test has been widely used in testing for association between two categorical responses. Spearman rank correlation and Kendall's tau are often used for measuring and testing association between two continuous or ordered categorical responses. However, the established statistical properties of these tests are only valid when each pair of responses are independent, where each sampling unit has only one pair of responses. When each sampling unit consists of a cluster of paired responses, the assumption of independent pairs is violated. In this article, we apply the within-cluster resampling technique to U-statistics to form new tests and rank-based correlation estimators for possibly tied clustered data. We develop large sample properties of the new proposed tests and estimators and evaluate their performance by simulations. The proposed methods are applied to a data set collected from a PET/CT imaging study for illustration. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Clinical comparison of branched DNA and reverse transcriptase-PCR and nucleic acid sequence-based amplification assay for the quantitation of circulating recombinant form_BC HIV-1 RNA in plasma.

PubMed

Pan, Pinliang; Tao, Xiaoxia; Zhang, Qi; Xing, Wenge; Sun, Xianguang; Pei, Lijian; Jiang, Yan

2007-12-01

To investigate the correlation between three viral load assays for circulating recombinant form (CRF)_BC. Recent studies in HIV-1 molecular epidemiology, reveals that CRF_BC is the dominant subtype of HIV-1 virus in mainland China, representing over 45% of the HIV-1 infected population. The performances of nucleic acid sequence-based amplification (NASBA), branched DNA (bDNA) and reverse transcriptase polymerase chain reaction (RT-PCR) were compared for the HIV-1 viral load detection and quantitation of CRF_BC in China. Sixteen HIV-1 positive and three HIV-1 negative samples were collected. Sequencing of the positive samples in the gp41 region was conducted. The HIV-1 viral load values were determined using bDNA, RT-PCR and NASBA assays. Deming regression analysis with SPSS 12.0 (SPS Inc., Chicago, Illinois, USA) was performed for data analysis. Sequencing and phylogenetic analysis of env gene (gp41) region of the 16 HIV-1 positive clinical specimens from Guizhou Province in southwest China revealed the dominance of the subtype CRF_BC in that region. A good correlation of their viral load values was observed among three assays. Pearson's correlation between RT-PCR and bDNA is 0.969, Lg(VL)RT-PCR = 0.969 * Lg(VL)bDNA + 0.55; Pearson's correlation between RT-PCR and NASBA is 0.968, Lg(VL)RT-PCR = 0.968 * Lg(VL)NASBA + 0.937; Pearson's correlation between NASBA and bDNA is 0.980, Lg(VL)NASBA = 0.980 * Lg(VL)bDNA - 0.318. When testing with 3 different assays, RT-PCR, bDNA and NASBA, the group of 16 HIV-1 positive samples showed the viral load value was highest for RT-PCR, followed by bDNA then NASBA, which is consistent with the former results in subtype B. The three viral load assays are highly correlative for CRF_BC in China.

Analysis of linear measurements on 3D surface models using CBCT data segmentation obtained by automatic standard pre-set thresholds in two segmentation software programs: an in vitro study.

PubMed

Poleti, Marcelo Lupion; Fernandes, Thais Maria Freire; Pagin, Otávio; Moretti, Marcela Rodrigues; Rubira-Bullen, Izabel Regina Fischer

2016-01-01

The aim of this in vitro study was to evaluate the reliability and accuracy of linear measurements on three-dimensional (3D) surface models obtained by standard pre-set thresholds in two segmentation software programs. Ten mandibles with 17 silica markers were scanned for 0.3-mm voxels in the i-CAT Classic (Imaging Sciences International, Hatfield, PA, USA). Twenty linear measurements were carried out by two observers two times on the 3D surface models: the Dolphin Imaging 11.5 (Dolphin Imaging & Management Solutions, Chatsworth, CA, USA), using two filters(Translucent and Solid-1), and in the InVesalius 3.0.0 (Centre for Information Technology Renato Archer, Campinas, SP, Brazil). The physical measurements were made by another observer two times using a digital caliper on the dry mandibles. Excellent intra- and inter-observer reliability for the markers, physical measurements, and 3D surface models were found (intra-class correlation coefficient (ICC) and Pearson's r ≥ 0.91). The linear measurements on 3D surface models by Dolphin and InVesalius software programs were accurate (Dolphin Solid-1 > InVesalius > Dolphin Translucent). The highest absolute and percentage errors were obtained for the variable R1-R1 (1.37 mm) and MF-AC (2.53 %) in the Dolphin Translucent and InVesalius software, respectively. Linear measurements on 3D surface models obtained by standard pre-set thresholds in the Dolphin and InVesalius software programs are reliable and accurate compared with physical measurements. Studies that evaluate the reliability and accuracy of the 3D models are necessary to ensure error predictability and to establish diagnosis, treatment plan, and prognosis in a more realistic way.

Complex Networks Dynamics Based on Events-Phase Synchronization and Intensity Correlation Applied to The Anomaly Patterns and Extremes in The Tropical African Climate System

NASA Astrophysics Data System (ADS)

Oluoch, K.; Marwan, N.; Trauth, M.; Loew, A.; Kurths, J.

2012-04-01

The African continent lie almost entirely within the tropics and as such its (tropical) climate systems are predominantly governed by the heterogeneous, spatial and temporal variability of the Hadley and Walker circulations. The variabilities in these meridional and zonal circulations lead to intensification or suppression of the intensities, durations and frequencies of the Inter-tropical Convergence Zone (ICTZ) migration, trade winds and subtropical high-pressure regions and the continental monsoons. The above features play a central role in determining the African rainfall spatial and temporal variability patterns. The current understanding of these climate features and their influence on the rainfall patterns is not sufficiently understood. Like many real-world systems, atmospheric-oceanic processes exhibit non-linear properties that can be better explored using non-linear (NL) methods of time-series analysis. Over the recent years, the complex network approach has evolved as a powerful new player in understanding spatio-temporal dynamics and evolution of complex systems. Together with NL techniques, it is continuing to find new applications in many areas of science and technology including climate research. We would like to use these two powerful methods to understand the spatial structure and dynamics of African rainfall anomaly patterns and extremes. The method of event synchronization (ES) developed by Quiroga et al., 2002 and first applied to climate networks by Malik et al., 2011 looks at correlations with a dynamic time lag and as such, it is a more intuitive way to correlate a complex and heterogeneous system like climate networks than a fixed time delay most commonly used. On the other hand, the short comings of ES is its lack of vigorous test statistics for the significance level of the correlations, and the fact that only the events' time indices are synchronized while all information about how the relative intensities propagate within network framework is lost. The new method we present is motivated by the ES and borrows ideas from signal processing where a signal is represented by its intensity and frequency. Even though the anomaly signals are not periodic, the idea of phase synchronization is not far fetched. It brings into one umbrella, the traditionally known linear Intensity correlation methods like Pearson correlation, spear-man's rank or non-linear ones like mutual information with the ES for non-linear temporal synchronization. The intensity correlation is only performed where there is a temporal synchronization. The former just measures how constant the intensity differences are. In other words, how monotonic are the two functions. The overall measure of correlation and synchronization is the product of the two coefficients. Complex networks constructed by this technique has all the advantages inherent in each of the techniques it borrows. But, it is more superior and able to uncover many known and unknown dynamical features in rainfall field or any variable of interest. The main aim of this work is to develop a method that can identify the footprints of coherent or incoherent structures within the ICTZ, the African and the Indian monsoons and the ENSO signal on the tropical African continent and their temporal evolution.

Modern calibration of Tussac grass (Poa flabellata) as a new paleoclimate proxy in the Falkland Islands

NASA Astrophysics Data System (ADS)

Groff, D. V.; Williams, D. G.; Gill, J. L.

2017-12-01

Monospecific stands of Tussac grasses (Poa flabellata) are a peat forming community found along coastal fringes of the Falkland Islands, and other sub-Antarctic islands in the South Atlantic region. Vegetation in peatlands record variation in regional precipitation and temperature in the cellulose of root and leaf plant tissues. A modern proof-of-concept study has determined how modern living P. flabellata records temperature, relative humidity, and precipitation using carbon (δ13C) and oxygen (δ18O) stable isotopes of leaf and root cellulose. At four locations in the Falkland Islands, P. flabellata plants were collected monthly and temperature (°C) and relative humidity (%) were measured continuously between September 1, 2015 to September 1, 2016. Monthly composite precipitation at each location was used to construct a local meteoric water line using δ2H and δ18O. Measurements of δ13C in leaf cellulose positively correlated with monthly average temperature (Pearson's r=0.82) and negatively correlated with relative humidity (Pearson's r = -0.76) across all sites, but not δ13C of root cellulose. Across all sites, the mean summer δ13C of leaf cellulose (-24.28‰) was significantly greater than winter (-26.80‰; t=8.91, df=73, p<0.001), and mean seasonal temperatures range from 9.32°C to 3.68°C for summer and winter, respectively. Measurements of δ18O in precipitation and leaf cellulose indicate a weak negative correlation (Pearson's r = -0.20), as well as δ18O in root cellulose (Pearson's r= -0.30). The δ13C isotope composition in leaf cellulose, along with the abundance of macrofossil P. flabellata leaves in peat deposits spanning the Holocene, supports the use of coastal grasslands formed by P. flabellata in the Falkland Islands as a paleoclimate proxy in the South Atlantic region.

Indices for estimating fractional snow cover in the western Tibetan Plateau

NASA Astrophysics Data System (ADS)

Shreve, Cheney M.; Okin, Gregory S.; Painter, Thomas H.

Snow cover in the Tibetan Plateau is highly variable in space and time and plays a key role in ecological processes of this cold-desert ecosystem. Resolution of passive microwave data is too low for regional-scale estimates of snow cover on the Tibetan Plateau, requiring an alternate data source. Optically derived snow indices allow for more accurate quantification of snow cover using higher-resolution datasets subject to the constraint of cloud cover. This paper introduces a new optical snow index and assesses four optically derived MODIS snow indices using Landsat-based validation scenes: MODIS Snow-Covered Area and Grain Size (MODSCAG), Relative Multiple Endmember Spectral Mixture Analysis (RMESMA), Relative Spectral Mixture Analysis (RSMA) and the normalized-difference snow index (NDSI). Pearson correlation coefficients were positively correlated with the validation datasets for all four optical snow indices, suggesting each provides a good measure of total snow extent. At the 95% confidence level, linear least-squares regression showed that MODSCAG and RMESMA had accuracy comparable to validation scenes. Fusion of optical snow indices with passive microwave products, which provide snow depth and snow water equivalent, has the potential to contribute to hydrologic and energy-balance modeling in the Tibetan Plateau.

The relationship between job stressors, hardy personality, coping resources and burnout in a sample of nurses: a correlational study at two time points.

PubMed

Garrosa, Eva; Rainho, Conceição; Moreno-Jiménez, Bernardo; Monteiro, Maria João

2010-02-01

Nursing is considered as a risk profession with high levels of stress and burnout, and these levels are probably increasing. This study assessed temporal and cross-sectional relationships between job stressors, hardy personality and coping resources on burnout dimensions among nurses. Temporal and cross-sectional effects were evaluated. A sample of 98 nurses from Portugal completed the Nursing Burnout Scale at two time points. The data were analysed using descriptive statistics, Pearson correlations, and hierarchical linear regression analyses regressing Wave 2 burnout dimensions. The study confirmed the specific contribution of control and challenged hardy personality dimensions as the explanation of burnout. However, commitment did not show any effects in this study. Social support and active coping were also relevant predictors of burnout dimensions. Specifically, active coping had an inverse temporal effect on depersonalisation and lack of personal accomplishment. In relation to the burnout process, depersonalisation appeared as an antecedent of lack of personal accomplishment. The present study is an initial step to comprehend the link between job stressors, hardy personality, coping resources and diminishing burnout. Copyright 2009 Elsevier Ltd. All rights reserved.

A study of International Baccalaureate science teachers' choices in curriculum and instruction

NASA Astrophysics Data System (ADS)

Jauss, Lanett S.

This study was designed to investigate the choices International Baccalaureate (IB) science teachers make in curriculum and instruction. Data was gathered via a survey completed by IB science teachers who had attended either an April, 2007 workshop in Reston, Virginia or a January, 2008 IB roundtable discussion in Kansas City, Missouri. Surveys solicited the different choices IB science teachers make for options, Internal Assessment (IA) activities, Theory of Knowledge (TOK) emphasis, and demographics. Teachers' reasons for their option choices were also analyzed. Statistical analysis was performed using SPSS descriptive statistics, Pearson's product-moment correlations, and linear regression. It was found that IB science teachers' most frequent reasons for their option choices were related to ease, interest, background, and available resources. IB science teachers used a variety of IA activities, with hands-on activities and worksheets being most frequent. IB science teachers did not emphasize inquiry, although they did include some aspects of it among their choices. IB science teachers preferred to use activities they design or those designed by other teachers. Years of teaching experience, both total and IB, were correlated to the level of use of some TOK tenets.

A foreground object features-based stereoscopic image visual comfort assessment model

NASA Astrophysics Data System (ADS)

Jin, Xin; Jiang, G.; Ying, H.; Yu, M.; Ding, S.; Peng, Z.; Shao, F.

2014-11-01

Since stereoscopic images provide observers with both realistic and discomfort viewing experience, it is necessary to investigate the determinants of visual discomfort. By considering that foreground object draws most attention when human observing stereoscopic images. This paper proposes a new foreground object based visual comfort assessment (VCA) metric. In the first place, a suitable segmentation method is applied to disparity map and then the foreground object is ascertained as the one having the biggest average disparity. In the second place, three visual features being average disparity, average width and spatial complexity of foreground object are computed from the perspective of visual attention. Nevertheless, object's width and complexity do not consistently influence the perception of visual comfort in comparison with disparity. In accordance with this psychological phenomenon, we divide the whole images into four categories on the basis of different disparity and width, and exert four different models to more precisely predict its visual comfort in the third place. Experimental results show that the proposed VCA metric outperformance other existing metrics and can achieve a high consistency between objective and subjective visual comfort scores. The Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are over 0.84 and 0.82, respectively.

Female homicide in Rio Grande do Sul, Brazil.

PubMed

Leites, Gabriela Tomedi; Meneghel, Stela Nazareth; Hirakata, Vania Noemi

2014-01-01

This study aimed to assess the female homicide rate due to aggression in Rio Grande do Sul, Brazil, using this as a "proxy" of femicide. This was an ecological study which correlated the female homicide rate due to aggression in Rio Grande do Sul, according to the 35 microregions defined by the Brazilian Institute of Geography and Statistics (IBGE), with socioeconomic and demographic variables access and health indicators. Pearson's correlation test was performed with the selected variables. After this, multiple linear regressions were performed with variables with p < 0.20. The standardized average of female homicide rate due to aggression in the period from 2003 to 2007 was 3.1 obits per 100 thousand. After multiple regression analysis, the final model included male mortality due to aggression (p = 0.016), the percentage of hospital admissions for alcohol (p = 0.005) and the proportion of ill-defined deaths (p = 0.015). The model have an explanatory power of 39% (adjusted r2 = 0.391). The results are consistent with other studies and indicate a strong relationship between structural violence in society and violence against women, in addition to a higher incidence of female deaths in places with high alcohol hospitalization.

Labor inclusion of individuals with disabilities: Managers' conceptions as a contributing factor.

PubMed

Brite, Roberta; Nunes, Francisco; Souza, Danielle

2015-01-01

This study aims to analyze the managers' conceptions involved in the process of labor inclusion in 18 supermarkets with 5,000 employees, 300 of whom with disabilities. A group of 90 managers working with people with disability completed a Conceptions of Disability Inventory (CDI) about their conceptions of people with disabilities. Their responses were categorized as follows: (a) disability as a spiritual manifestation; b) disability as a deviation from normality; (c) disability based on assumptions of inclusion; (d) disability assessed from performance criteria; (e) disability assessed from the connection established with the work organization; (f) disability conceived by contracting benefits, and (g) disability based on the perception of the need for training. Based on the outcomes of the Pearson Correlation Matrix, significant linear correlations were found in seven managers' conceptions of disability. The results also indicate that the managers' conceptions contributed to differentiated inclusionist actions based on their perceptions related to people with disabilities. This study data contributes to identifying the best practices in labor inclusion. The outcomes of the present study could lead to development of a public policy aimed towards humanizing job alternatives for people with disability.

Characterizing Facial Skin Ageing in Humans: Disentangling Extrinsic from Intrinsic Biological Phenomena

PubMed Central

Trojahn, Carina; Dobos, Gabor; Lichterfeld, Andrea; Blume-Peytavi, Ulrike; Kottner, Jan

2015-01-01

Facial skin ageing is caused by intrinsic and extrinsic mechanisms. Intrinsic ageing is highly related to chronological age. Age related skin changes can be measured using clinical and biophysical methods. The aim of this study was to evaluate whether and how clinical characteristics and biophysical parameters are associated with each other with and without adjustment for chronological age. Twenty-four female subjects of three age groups were enrolled. Clinical assessments (global facial skin ageing, wrinkling, and sagging), and biophysical measurements (roughness, colour, skin elasticity, and barrier function) were conducted at both upper cheeks. Pearson's correlations and linear regression models adjusted for age were calculated. Most of the measured parameters were correlated with chronological age (e.g., association with wrinkle score, r = 0.901) and with each other (e.g., residual skin deformation and wrinkle score, r = 0.606). After statistical adjustment for age, only few associations remained (e.g., mean roughness (R z) and luminance (L *),  β = −0.507, R 2 = 0.377). Chronological age as surrogate marker for intrinsic ageing has the most important influence on most facial skin ageing signs. Changes in skin elasticity, wrinkling, sagging, and yellowness seem to be caused by additional extrinsic ageing. PMID:25767806

Femicides: female homicide in Brazil.

PubMed

Meneghel, Stela Nazareth; Hirakata, Vania Naomi

2011-06-01

To assess female homicide rates due to aggression according to sociodemographic and health indicators. Ecological study on female homicides due to aggression in Brazil between 2003 and 2007. Information on 19,459 deaths were obtained form the Brazilian Mortality Database. Standardized female homicide rates due to aggression were correlated with 28 socioeconomic, demographic and health indicators, using Pearson's correlation test. Multiple linear regression was performed including variables with p < 0.20 and excluding those with multicollinearity. The standardized female homicide rate due to aggression was 4.1/100,000 during the study period. After adjustment, three variables remained significantly associated with female homicides: birth rate (p = 0.072), percentage of Evangelicals (p = 0.019) and male homicides due to aggression (p < 0.001). The model had a predictive power of 69% (r² = 0.699). The Brazilian states of Espírito Santo, Pernambuco, Mato Grosso, Rio de Janeiro, Rondônia, Alagoas, Mato Grosso do Sul, Roraima e Amapá showed the highest rates during the study period. The female homicide rates due to aggression were high in Brazil and varied by region. The association with male homicides due to aggression stresses the importance of reducing structural violence to protect women against violence.

Estimation of aboveground biomass in Mediterranean forests by statistical modelling of ASTER fraction images

NASA Astrophysics Data System (ADS)

Fernández-Manso, O.; Fernández-Manso, A.; Quintano, C.

2014-09-01

Aboveground biomass (AGB) estimation from optical satellite data is usually based on regression models of original or synthetic bands. To overcome the poor relation between AGB and spectral bands due to mixed-pixels when a medium spatial resolution sensor is considered, we propose to base the AGB estimation on fraction images from Linear Spectral Mixture Analysis (LSMA). Our study area is a managed Mediterranean pine woodland (Pinus pinaster Ait.) in central Spain. A total of 1033 circular field plots were used to estimate AGB from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) optical data. We applied Pearson correlation statistics and stepwise multiple regression to identify suitable predictors from the set of variables of original bands, fraction imagery, Normalized Difference Vegetation Index and Tasselled Cap components. Four linear models and one nonlinear model were tested. A linear combination of ASTER band 2 (red, 0.630-0.690 μm), band 8 (short wave infrared 5, 2.295-2.365 μm) and green vegetation fraction (from LSMA) was the best AGB predictor (Radj2=0.632, the root-mean-squared error of estimated AGB was 13.3 Mg ha-1 (or 37.7%), resulting from cross-validation), rather than other combinations of the above cited independent variables. Results indicated that using ASTER fraction images in regression models improves the AGB estimation in Mediterranean pine forests. The spatial distribution of the estimated AGB, based on a multiple linear regression model, may be used as baseline information for forest managers in future studies, such as quantifying the regional carbon budget, fuel accumulation or monitoring of management practices.

Relation of Cardiometabolic Risk Factors between Parents and Children.

PubMed

Halvorsen, Tanya; Moran, Antoinette; Jacobs, David R; Steffen, Lyn M; Sinaiko, Alan R; Zhou, Xia; Steinberger, Julia

2015-11-01

To explore the relations of parent-child cardiometabolic risk factors and assess the influence of adiposity on these associations. Associations of adiposity, blood pressure (BP), lipids, fasting insulin and glucose, and a risk factor cluster score (CS) were evaluated in a cross-sectional study of 179 parents and their children (6-18 years, N = 255). Insulin resistance was assessed by euglycemic clamp in parents and children aged 10 years or older. Metabolic syndrome in parents was defined by National Cholesterol Education Program's Adult Treatment Panel III criteria. CSs of the risk factors were created based on age-specific z-scores. Analyses included Pearson correlation and linear regression, adjusted for parent and child age, sex, race, and body mass index (BMI), accounting for within-family correlation. We found positive parent-child correlations for measures of adiposity (BMI, BMI percentile, waist, subcutaneous fat, and visceral fat; r = 0.22-0.34, all P ≤ .003), systolic BP (r = 0.20, P = .002), total cholesterol (r = 0.39, P < .001), low-density lipoprotein cholesterol (r = 0.34, P < .001), high density lipoprotein cholesterol (r = 0.26, P < .001), triglycerides (r = 0.19, P = .01), and insulin sensitivity (r = 0.22, P = .02) as well as CSs (r = 0.15, P = .02). After adjustment for BMI all parent-child correlations, except systolic BP, remained significant. Although adiposity is strongly correlated between parents and children, many cardiometabolic risk factors correlate independent of parent and child BMI. Adverse parental cardiometabolic profiles may identify at-risk children independent of the child's adiposity status. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationship between parent–infant attachment and parental satisfaction with supportive nursing care

PubMed Central

Ghadery-Sefat, Akram; Abdeyazdan, Zahra; Badiee, Zohreh; Zargham-Boroujeni, Ali

2016-01-01

Background: Parent–infant attachment is an important factor in accepting parenting role, accelerating infant survival, and adjusting to the environment outside the uterus. Since family supportive interventions can strengthen the parent–infant caring relationship, this study sought to investigate the relationship between mother–infant attachment and satisfaction of the mothers with the supportive nursing care received in the neonatal intensive care unit (NICU). Materials and Methods: In this descriptive–correlational study, 210 mothers with premature infants who were hospitalized in the NICUs affiliated to Isfahan Medical University hospitals took part. The data were collected via Maternal Postnatal Attachment Scale and researcher's self-tailored questionnaire based on Nurse Parent Support Tool. Pearson correlation coefficient and multiple linear regressions were used to analyze the collected data. Results: The results showed that the overall score of mother–infant attachment and the overall score of maternal satisfaction correlated with a correlation coefficient of r = 0.195. Also, the overall score of mother–infant attachment and mothers’ satisfaction scores in the emotional, communicative-informative, and self-confidence domains correlated with correlation coefficients of r = 0.182, r = 0.0.189, and r = 0.0.304, respectively. The results of multiple regression analysis revealed that about 15% of changes in the dependent variable (mother–infant attachment) could be explained by different dimensions of mothers’ satisfaction. Conclusions: The results of the study showed that mother–infant attachment improved by increasing mothers’ satisfaction of supportive nursing care. Therefore, it seems necessary to increase maternal satisfaction through given nursing care support, in order to promote mother–infant attachment. PMID:26985225

Relationship between parent-infant attachment and parental satisfaction with supportive nursing care.

PubMed

Ghadery-Sefat, Akram; Abdeyazdan, Zahra; Badiee, Zohreh; Zargham-Boroujeni, Ali

2016-01-01

Parent-infant attachment is an important factor in accepting parenting role, accelerating infant survival, and adjusting to the environment outside the uterus. Since family supportive interventions can strengthen the parent-infant caring relationship, this study sought to investigate the relationship between mother-infant attachment and satisfaction of the mothers with the supportive nursing care received in the neonatal intensive care unit (NICU). In this descriptive-correlational study, 210 mothers with premature infants who were hospitalized in the NICUs affiliated to Isfahan Medical University hospitals took part. The data were collected via Maternal Postnatal Attachment Scale and researcher's self-tailored questionnaire based on Nurse Parent Support Tool. Pearson correlation coefficient and multiple linear regressions were used to analyze the collected data. The results showed that the overall score of mother-infant attachment and the overall score of maternal satisfaction correlated with a correlation coefficient of r = 0.195. Also, the overall score of mother-infant attachment and mothers' satisfaction scores in the emotional, communicative-informative, and self-confidence domains correlated with correlation coefficients of r = 0.182, r = 0.0.189, and r = 0.0.304, respectively. The results of multiple regression analysis revealed that about 15% of changes in the dependent variable (mother-infant attachment) could be explained by different dimensions of mothers' satisfaction. The results of the study showed that mother-infant attachment improved by increasing mothers' satisfaction of supportive nursing care. Therefore, it seems necessary to increase maternal satisfaction through given nursing care support, in order to promote mother-infant attachment.

Do Deregulated Cas Proteins Induce Genomic Instability in Early-Stage Ovarian Cancer

DTIC Science & Technology

2006-12-01

use Western blot analysis of tumor lysates to correlate expression of HEF1, p130Cas, Aurora A, and phospho-Aurora A. This analysis is in progress. In...and importantly, evaluated a number of different detection/image analysis systems to ensure reproducible quantitative results. We have used a pilot...reproducible Interestingly, preliminary statistical analysis using Spearman and Pearson correlation indicates at least one striking correlation

Systematic bias of correlation coefficient may explain negative accuracy of genomic prediction.

PubMed

Zhou, Yao; Vales, M Isabel; Wang, Aoxue; Zhang, Zhiwu

2017-09-01

Accuracy of genomic prediction is commonly calculated as the Pearson correlation coefficient between the predicted and observed phenotypes in the inference population by using cross-validation analysis. More frequently than expected, significant negative accuracies of genomic prediction have been reported in genomic selection studies. These negative values are surprising, given that the minimum value for prediction accuracy should hover around zero when randomly permuted data sets are analyzed. We reviewed the two common approaches for calculating the Pearson correlation and hypothesized that these negative accuracy values reflect potential bias owing to artifacts caused by the mathematical formulas used to calculate prediction accuracy. The first approach, Instant accuracy, calculates correlations for each fold and reports prediction accuracy as the mean of correlations across fold. The other approach, Hold accuracy, predicts all phenotypes in all fold and calculates correlation between the observed and predicted phenotypes at the end of the cross-validation process. Using simulated and real data, we demonstrated that our hypothesis is true. Both approaches are biased downward under certain conditions. The biases become larger when more fold are employed and when the expected accuracy is low. The bias of Instant accuracy can be corrected using a modified formula. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Liver Cancer Mortality and Food Consumption in Serbia, 1991-2010: An Ecological Study.

PubMed

Ilić, Milena; Radoman, Kristina; Konević, Slavica; Ilić, Irena

2016-06-01

This paper investigates the correlation between liver cancer mortality and consumption of food-groups in Serbia. We conducted an ecological study. The study comprised the population of the Republic of Serbia (about 7.5 million inhabitants) during the period 1991-2010. This ecological study included the data on food consumption per capita which were obtained by the Household Budget Survey and mortality data for liver cancer made available by the National Statistical Office. Linear trend model was used to assess a trend of age-adjusted liver cancer mortality rates (per 100,000 persons) that were calculated by the method of direct standardization using the World Standard Population. Pearson correlation was performed to examine the association between liver cancer mortality and per capita food consumption quantified with a correlation coefficient (r value). In Serbia, over the past two decades a significantly decreasing trend of liver cancer mortality rates has been observed (p<0.001). Liver cancer mortality was significantly (p<0.01) positively correlated with animal fat, beef, wine and spirits intake (r=0.713, 0.631, 0.632 and 0.745, respectively). A weakly positive correlation between milk consumption and mortality from liver cancer (r=0.559, p<0.05) was found only among women. The strongest correlation was found between spirits consumption and liver cancer mortality rates in women (r=0.851, p<0.01). A negative correlation between coffee consumption and age-adjusted liver cancer mortality rates was found (r=0.516, p<0.05) only for the eldest men (aged 65 years or older). Correlations between liver cancer and dietary habits were observed and further effort is needed in order to investigate a possible causative association, using epidemiological analytical studies. Copyright© by the National Institute of Public Health, Prague 2015.

The potential link between sugar-sweetened beverage consumption and post-exercise airway narrowing across puberty: a longitudinal cohort study.

PubMed

Emerson, Sam R; Rosenkranz, Sara K; Rosenkranz, Richard R; Kurti, Stephanie P; Harms, Craig A

2016-09-01

The prevalence of asthma is rising, presenting serious public health challenges. Recent data suggest that sugar-sweetened beverage (SSB) consumption plays a role in asthma aetiology. The purpose of the present study was to determine whether SSB consumption is linked to post-exercise airway narrowing (predictor of asthma development) across puberty. Participants completed pulmonary function tests, physical activity and dietary habit questionnaires, and an exercise test to exhaustion. Community in Manhattan, Kansas, USA. We recruited ten boys and ten girls from an original cohort of forty participants tested in our laboratory approximately 5 years prior. Participants were aged 9·7 (sd 0·9) years at baseline and 14·7 (sd 0·9) years at follow-up. Pre-puberty, boys consumed 6·8 (sd 4·8) servings/week and girls consumed 6·9 (sd 3·7) servings/week, while post-puberty boys consumed 11·5 (sd 5·3) servings/week and girls consumed 7·7 (sd 4·3) servings/week. Using Pearson correlation, SSB consumption was not significantly related to post-exercise airway narrowing at pre-puberty (r=-0·35, P=0·130). In linear regression analyses, SSB consumption was significantly related to post-exercise airway narrowing post-puberty before (standardized β=-0·60, P=0·005) but not after (standardized β=-0·33, P=0·211) adjustment for confounders. Change in SSB consumption from pre- to post-puberty was significantly associated with post-exercise airway narrowing post-puberty (r=-0·61, P=0·010) and change in post-exercise airway narrowing from pre- to post-puberty (r=-0·45, P=0·048) when assessed via Pearson correlations. These findings suggest a possible link between SSB consumption and asthma development during maturation. Reduced SSB intake may be a possible public health avenue for blunting rising asthma prevalence.

Bioimpedance analysis vs. DEXA as a screening tool for osteosarcopenia in lean, overweight and obese Caucasian postmenopausal females.

PubMed

Peppa, Melpomeni; Stefanaki, Charikleia; Papaefstathiou, Athanasios; Boschiero, Dario; Dimitriadis, George; Chrousos, George P

2017-04-01

We aimed at evaluating the efficiency of a newly developed, advanced Bioimpedance Analysis (BIA-ACC®) device as a screening tool for determining the degree of obesity and osteosarcopenia in postmenopausal women with normal or decreased bone density determined by Dual-Energy X-Ray absorptiometry (DEXA) in a representative sample of Greek postmenopausal women. This is a single-gate cross-sectional study of body composition measured by BIA-ACC® and DEXA. Postmenopausal females with BMI ranging from 18.5 to 40 kg/m2 were subjected to two consecutive measurements of DEXA and BIA-ACC® within 5-10 minutes of each other. We used Pearson's co-efficient to examine linear correlations, the intraclass correlation co-efficient (ICC) to test reliability, Bland-Atman plots to assess bias and Deming regressions to establish the agreement in parameters measured by BIA-ACC® and DEXA. Last, we used ANOVA, with Bonferroni correction and Dunnett T3 post hoc tests, for assessing the differences between quantitative and Pearson's x2 between qualitative variables. Our sample consisted of 84 overweight/obese postmenopausal women, aged 39-83 years, of whom 22 had normal bone density, 38 had osteopenia and 24 had osteoporosis based on DEXA measurements, using quota sampling. ICCs and Deming regressions showed strong agreement between BIA-ACC® and DEXA and demonstrated minimal proportional differences of no apparent clinical significance. Bland-Altman plots indicated minimal biases. Fat, skeletal and bone mass measured by BIA-ACC® and DEXA were increased in the non-osteopenic/non-osteoporotic women compared with those of the osteopenic and osteoporotic groups. BIA-ACC® is a rapid, bloodless and useful screening tool for determining body composition adiposity and presence of osteo-sarcopenic features in postmenopausal women. Women with osteopenia and osteoporosis evaluated by DEXA had decreased fat, skeletal and bone mass compared with normal bone density women, suggesting concordance in the change of these three organ masses in postmenopausal women.

Association between Climatic Variables and Malaria Incidence: A Study in Kokrajhar District of Assam, India

PubMed Central

Nath, Dilip C.; Mwchahary, Dimacha Dwibrang

2013-01-01

A favorable climatic condition for transmission of malaria prevails in Kokrajhar district throughout the year. A sizeable part of the district is covered by forest due to which dissimilar dynamics of malaria transmission emerge in forest and non-forest areas. Observed malaria incidence rates of forest area, non-forest area and the whole district over the period 2001-2010 were considered for analyzing temporal correlation between malaria incidence and climatic variables. Associations between the two were examined by Pearson correlation analysis. Cross-correlation tests were performed between pre-whitened series of climatic variable and malaria series. Linear regressions were used to obtain linear relationships between climatic factors and malaria incidence, while weighted least squares regression was used to construct models for explaining and estimating malaria incidence rates. Annual concentration of malaria incidence was analyzed by Markham technique by obtaining seasonal index. Forest area and non-forest area have distinguishable malaria seasons. Relative humidity was positively correlated with z malaria incidence, while temperature series were negatively correlated with non-forest malaria incidence. There was higher seasonality of concentration of malaria in the forest area than non-forest area. Significant correlation between annual changes in malaria cases in forest area and temperature was observed (coeff=0.689, p=0.040). Separate reliable models constructed for forecasting malaria incidence rates based on the combined influence of climatic variables on malaria incidence in different areas of the district were able to explain substantial percentage of observed variability in the incidence rates (R2adj=45.4%, 50.6%, 47.2%; p< .001 for all). There is an intricate association between climatic variables and malaria incidence of the district. Climatic variables influence malaria incidence in forest area and non-forest area in different ways. Rainfall plays a primary role in characterizing malaria incidences in the district. Malaria parasites in the district had adapted to a relative humidity condition higher than the normal range for transmission in India. Instead of individual influence of the climatic variables, their combined influence was utilizable for construction of models. PMID:23283041

Association between climatic variables and malaria incidence: a study in Kokrajhar district of Assam, India.

PubMed

Nath, Dilip C; Mwchahary, Dimacha Dwibrang

2012-11-11

A favorable climatic condition for transmission of malaria prevails in Kokrajhar district throughout the year. A sizeable part of the district is covered by forest due to which dissimilar dynamics of malaria transmission emerge in forest and non-forest areas. Observed malaria incidence rates of forest area, non-forest area and the whole district over the period 2001-2010 were considered for analyzing temporal correlation between malaria incidence and climatic variables. Associations between the two were examined by Pearson correlation analysis. Cross-correlation tests were performed between pre-whitened series of climatic variable and malaria series. Linear regressions were used to obtain linear relationships between climatic factors and malaria incidence, while weighted least squares regression was used to construct models for explaining and estimating malaria incidence rates. Annual concentration of malaria incidence was analyzed by Markham technique by obtaining seasonal index. Forest area and non-forest area have distinguishable malaria seasons. Relative humidity was positively correlated with forest malaria incidence, while temperature series were negatively correlated with non-forest malaria incidence. There was higher seasonality of concentration of malaria in the forest area than non-forest area. Significant correlation between annual changes in malaria cases in forest area and temperature was observed (coeff=0.689, p=0.040). Separate reliable models constructed for forecasting malaria incidence rates based on the combined influence of climatic variables on malaria incidence in different areas of the district were able to explain substantial percentage of observed variability in the incidence rates (R2adj=45.4%, 50.6%, 47.2%; p< .001 for all). There is an intricate association between climatic variables and malaria incidence of the district. Climatic variables influence malaria incidence in forest area and non-forest area in different ways. Rainfall plays a primary role in characterizing malaria incidences in the district. Malaria parasites in the district had adapted to a relative humidity condition higher than the normal range for transmission in India. Instead of individual influence of the climatic variables, their combined influence was utilizable for construction of models.

Surgery residency curriculum examination scores predict future American Board of Surgery in-training examination performance.

PubMed

Webb, Travis P; Paul, Jasmeet; Treat, Robert; Codner, Panna; Anderson, Rebecca; Redlich, Philip

2014-01-01

A protected block curriculum (PBC) with postcurriculum examinations for all surgical residents has been provided to assure coverage of core curricular topics. Biannual assessment of resident competency will soon be required by the Next Accreditation System. To identify opportunities for early medical knowledge assessment and interventions, we examined whether performance in postcurriculum multiple-choice examinations (PCEs) is predictive of performance in the American Board of Surgery In-Training Examination (ABSITE) and clinical service competency assessments. Retrospective single-institutional education research study. Academic general surgery residency program. A total of 49 surgical residents. Data for PGY1 and PGY2 residents participating in the 2008 to 2012 PBC are included. Each resident completed 6 PCEs during each year. The results of 6 examinations were correlated to percentage-correct ABSITE scores and clinical assessments based on the 6 Accreditation Council for Graduate Medical Education core competencies. Individual ABSITE performance was compared between PGY1 and PGY2. Statistical analysis included multivariate linear regression and bivariate Pearson correlations. A total of 49 residents completed the PGY1 PBC and 36 completed the PGY2 curriculum. Linear regression analysis of percentage-correct ABSITE and PCE scores demonstrated a statistically significant correlation between the PGY1 PCE 1 score and the subsequent PGY1 ABSITE score (p = 0.037, β = 0.299). Similarly, the PGY2 PCE 1 score predicted performance in the PGY2 ABSITE (p = 0.015, β = 0.383). The ABSITE scores correlated between PGY1 and PGY2 with statistical significance, r = 0.675, p = 0.001. Performance on the 6 Accreditation Council for Graduate Medical Education core competencies correlated between PGY1 and PGY2, r = 0.729, p = 0.001, but did not correlate with PCE scores during either years. Within a mature PBC, early performance in a PGY1 and PGY2 PCE is predictive of performance in the respective ABSITE. This information can be used for formative assessment and early remediation of residents who are predicted to be at risk for poor performance in the ABSITE. Copyright © 2014 Association of Program Directors in Surgery. All rights reserved.

Scale-Free Nonparametric Factor Analysis: A User-Friendly Introduction with Concrete Heuristic Examples.

ERIC Educational Resources Information Center

Mittag, Kathleen Cage

Most researchers using factor analysis extract factors from a matrix of Pearson product-moment correlation coefficients. A method is presented for extracting factors in a non-parametric way, by extracting factors from a matrix of Spearman rho (rank correlation) coefficients. It is possible to factor analyze a matrix of association such that…

Understanding the Relationship between School-Based Management, Emotional Intelligence and Performance of Religious Upper Secondary School Principals in Banten Province

ERIC Educational Resources Information Center

Muslihah, Oleh Eneng

2015-01-01

The research examines the correlation between the understanding of school-based management, emotional intelligences and headmaster performance. Data was collected, using quantitative methods. The statistical analysis used was the Pearson Correlation, and multivariate regression analysis. The results of this research suggest firstly that there is…

Personality Characteristics of Women Religious: A Three Year Follow-Up.

ERIC Educational Resources Information Center

Melamed, Audrey

Sixty-two women religious were administered the 16 Personality Factor Questionnaire (16-PF) and the Personal Orientation Inventory in 1969 and again in 1972. The Pearson product-moment correlations on the 16-PF ranged from .18 to .77; the mean correlation was .36. Statistical significance was reached on 14 to 16 factors. In a "t"…

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…

Validity and reproducibility of a food frequency questionnaire for assessment of fruit and vegetable intake in Iranian adults*

PubMed Central

Mohammadifard, Noushin; Omidvar, Nasrin; Houshiarrad, Anahita; Neyestani, Tirang; Naderi, Gholam-Ali; Soleymani, Bahram

2011-01-01

BACKGROUND: This study's aim was to design and validate a semi-quantitative food frequency questionnaire (FFQ) for assessment of fruits and vegetables (FV) consumption in adults of Isfahan by comparing the FFQ with dietary reference method and blood plasma levels of beta-carotene, vitamin C, and retinol. METHODS: This validation study was performed on 123 healthy adults of Isfahan. FV intake was assessed using a 110-item FFQ. Data collection was performed during two different time periods to control for seasonal effects, fall/winter (cold season) and spring/summer (warm season). In each phase a FFQ and 1 day recall, and 2 days of food records as the dietary reference method were completed and plasma vitamin C, beta-carotene and retinol were measured. Data was analyzed by Pearson or Spearman and intraclass correlations. RESULTS: Serum Lipids, sex, age, body mass index (BMI) and educational level adjusted Pearson correlation coefficient of FV with plasma vitamin C, beta-carotene and retinol were 0.55, 0.47 and 0.28 in the cold season (p < 0.05) and 0.52, 0.45 and 0.35 in the warm season (p < 0.001), respectively. Energy and fat intake, sex, age, BMI and educational level adjusted Pearson correlation coefficient for FV with dietary reference method in the cold and warm seasons were 0.62 and 0.60, respectively (p < 0.001). Intraclass correlation for reproducibility of FFQ in FV was 0.65 (p<0.001). CONCLUSIONS: The designed FFQ had a good criterion validity and reproducibility for assessment of FV intake. Thus, it can serve as a valid tool in epidemiological studies to assess fruit and vegetable intake. PMID:22973322

Automated Grading System for Evaluation of Superficial Punctate Keratitis Associated With Dry Eye.

PubMed

Rodriguez, John D; Lane, Keith J; Ousler, George W; Angjeli, Endri; Smith, Lisa M; Abelson, Mark B

2015-04-01

To develop an automated method of grading fluorescein staining that accurately reproduces the clinical grading system currently in use. From the slit lamp photograph of the fluorescein-stained cornea, the region of interest was selected and punctate dot number calculated using software developed with the OpenCV computer vision library. Images (n = 229) were then divided into six incremental severity categories based on computed scores. The final selection of 54 photographs represented the full range of scores: nine images from each of six categories. These were then evaluated by three investigators using a clinical 0 to 4 corneal staining scale. Pearson correlations were calculated to compare investigator scores, and mean investigator and automated scores. Lin's Concordance Correlation Coefficients (CCC) and Bland-Altman plots were used to assess agreement between methods and between investigators. Pearson's correlation between investigators was 0.914; mean CCC between investigators was 0.882. Bland-Altman analysis indicated that scores assessed by investigator 3 were significantly higher than those of investigators 1 and 2 (paired t-test). The predicted grade was calculated to be: Gpred = 1.48log(Ndots) - 0.206. The two-point Pearson's correlation coefficient between the methods was 0.927 (P < 0.0001). The CCC between predicted automated score Gpred and mean investigator score was 0.929, 95% confidence interval (0.884-0.957). Bland-Altman analysis did not indicate bias. The difference in SD between clinical and automated methods was 0.398. An objective, automated analysis of corneal staining provides a quality assurance tool to be used to substantiate clinical grading of key corneal staining endpoints in multicentered clinical trials of dry eye.

Validation of a quantitative Eimeria spp. PCR for fresh droppings of broiler chickens.

PubMed

Peek, H W; Ter Veen, C; Dijkman, R; Landman, W J M

2017-12-01

A quantitative Polymerase Chain Reaction (qPCR) for the seven chicken Eimeria spp. was modified and validated for direct use on fresh droppings. The analytical specificity of the qPCR on droppings was 100%. Its analytical sensitivity (non-sporulated oocysts/g droppings) was 41 for E. acervulina, ≤2900 for E. brunetti, 710 for E. praecox, 1500 for E. necatrix, 190 for E. tenella, 640 for E. maxima, and 1100 for E. mitis. Field validation of the qPCR was done using droppings with non-sporulated oocysts from 19 broiler flocks. To reduce the number of qPCR tests five grams of each pooled sample (consisting of ten fresh droppings) per time point were blended into one mixed sample. Comparison of the oocysts per gram (OPG)-counting method with the qPCR using pooled samples (n = 1180) yielded a Pearson's correlation coefficient of 0.78 (95% CI: 0.76-0.80) and a Pearson's correlation coefficient of 0.76 (95% CI: 0.70-0.81) using mixed samples (n = 236). Comparison of the average of the OPG-counts of the five pooled samples with the mixed sample per time point (n = 236) showed a Pearson's correlation coefficient (R) of 0.94 (95% CI: 0.92-0.95) for the OPG-counting method and 0.87 (95% CI: 0.84-0.90) for the qPCR. This indicates that mixed samples are practically equivalent to the mean of five pooled samples. The good correlation between the OPG-counting method and the qPCR was further confirmed by the visual agreement between the total oocyst/g shedding patterns measured with both techniques in the 19 broiler flocks using the mixed samples.

Self-adaptive signals separation for non-contact heart rate estimation from facial video in realistic environments.

PubMed

Liu, Xuenan; Yang, Xuezhi; Jin, Jing; Li, Jiangshan

2018-06-05

Recent researches indicate that facial epidermis color varies with the rhythm of heat beats. It can be captured by consumer-level cameras and, astonishingly, be adopted to estimate heart rate (HR). The HR estimated remains not as precise as required in practical environment where illumination interference, facial expressions, or motion artifacts are involved, though numerous methods have been proposed in the last few years. A novel algorithm is proposed to make non-contact HR estimation technique more robust. First, the face of subject is detected and tracked to follow the head movement. The facial region then falls into several blocks, and the chrominance feature of each block is extracted to establish raw HR sub-signal. Self-adaptive signals separation (SASS) is performed to separate the noiseless HR sub-signals from raw sub-signals. On that basis, the noiseless sub-signals full of HR information are selected using weight-based scheme to establish the holistic HR signal, from which average HR is computed adopting wavelet transform and data filter. Forty subjects take part in our experiments, whose facial videos are recorded by a normal webcam with the frame rate of 30 fps under ambient lighting conditions. The average HR estimated by our method correlates strongly with ground truth measurements, as indicated in experimental results measured in static scenario with the Pearson's correlation r=0.980 and dynamic scenario with the Pearson's correlation r=0.897. Our method, compared to the newest method, decreases the error rate by 38.63% and increases the Pearson's correlation by 15.59%, indicating that our method evidently outperforms state-of-the-art non-contact HR estimation methods in realistic environments. © 2018 Institute of Physics and Engineering in Medicine.

Parametric distribution approach for flow availability in small hydro potential analysis

NASA Astrophysics Data System (ADS)

Abdullah, Samizee; Basri, Mohd Juhari Mat; Jamaluddin, Zahrul Zamri; Azrulhisham, Engku Ahmad; Othman, Jamel

2016-10-01

Small hydro system is one of the important sources of renewable energy and it has been recognized worldwide as clean energy sources. Small hydropower generation system uses the potential energy in flowing water to produce electricity is often questionable due to inconsistent and intermittent of power generated. Potential analysis of small hydro system which is mainly dependent on the availability of water requires the knowledge of water flow or stream flow distribution. This paper presented the possibility of applying Pearson system for stream flow availability distribution approximation in the small hydro system. By considering the stochastic nature of stream flow, the Pearson parametric distribution approximation was computed based on the significant characteristic of Pearson system applying direct correlation between the first four statistical moments of the distribution. The advantage of applying various statistical moments in small hydro potential analysis will have the ability to analyze the variation shapes of stream flow distribution.

Statistical characteristics of the sequential detection of signals in correlated noise

NASA Astrophysics Data System (ADS)

Averochkin, V. A.; Baranov, P. E.

1985-10-01

A solution is given to the problem of determining the distribution of the duration of the sequential two-threshold Wald rule for the time-discrete detection of determinate and Gaussian correlated signals on a background of Gaussian correlated noise. Expressions are obtained for the joint probability densities of the likelihood ratio logarithms, and an analysis is made of the effect of correlation and SNR on the duration distribution and the detection efficiency. Comparison is made with Neumann-Pearson detection.

Swedish Consumers' Perception of Food Quality and Sustainability in Relation to Organic Food Production.

PubMed

Bosona, Techane; Gebresenbet, Girma

2018-04-01

Consumers' demand for locally produced and organic foods has increased in Sweden. This paper presents the results obtained from the analysis of data acquired from 100 consumers in Sweden who participated in an online survey during March to June 2016. The objective was to identify consumers' demand in relation to organic food and sustainable food production, and to understand how the consumers evaluate food quality and make buying decisions. Qualitative descriptions, descriptive statistics and Pearson's Chi-square test (with alpha value of p < 0.05 as level of significance), and Pearson's correlation coefficient were used for analysis. About 72% of participants have the perception that organic food production method is more sustainable than conventional methods. Female consumers have more positive attitudes than men towards organic food. However, age difference, household size and income level do not significantly influence the consumers' perception of sustainable food production concepts. Regionality, sustainable methods of production and organic production are the most important parameters to characterize the food as high quality and make buying decisions. On the other hand, product uniformity, appearance, and price were found to be relatively less important parameters. Food buying decisions and food quality were found to be highly related with Pearson's correlation coefficient of r = 0.99.

Correlation between the pain numeric rating scale and the 12-item WHO Disability Assessment Schedule 2.0 in patients with musculoskeletal pain.

PubMed

Saltychev, Mikhail; Bärlund, Esa; Laimi, Katri

2018-03-01

The aim of this study was to assess the correlation between pain severity measured on a numeric rating scale and restrictions of functioning measured with the WHO Disability Assessment Schedule (WHODAS 2.0). This was a cross-sectional study of 1207 patients with musculoskeletal pain conditions. Correlation was assessed using Spearman's and Pearson tests. Although all the Spearman's rank correlations between WHODAS 2.0 items and pain severity were statistically significant, they were mostly weak, with only a few moderate associations for 'S2 household responsibilities', 'S8 washing', 'S9 dressing', and 'S12 day-to-day work'. The correlation between the WHODAS 2.0 total score and pain severity was also moderate: 0.41 [95% confidence interval (CI): 0.36-0.45] for average pain and 0.42 (95% CI: 0.37-0.46) for worst pain. The correlation between the WHODAS 2.0 total score and pain level was also assessed using Pearson's product-moment correlation, yielding figures that were similar to Spearman's correlation: 0.42 (P<0.0001, 95% CI: 0.37-0.46) for average pain and 0.39 (P<0.0001, 95% CI: 0.34-0.44) for worst pain. Among patients with chronic musculoskeletal pain, the correlation between pain severity measured by numeric rating scale and functioning level measured by WHODAS 2.0 was weak to moderate, with slightly stronger associations in physical domains of functioning.

Examining the relationship of ethnicity, gender and social cognitive factors with the academic achievement of first-year engineering students

NASA Astrophysics Data System (ADS)

Carr, Bruce Henry

The purpose of the study was to examine the relationships of social cognitive factors and their influence on the academic performance of first-year engineering students. The nine social cognitive variables identified were under the groupings of personal support, occupational self-efficacy, academic self-efficacy, vocational interests, coping, encouragement, discouragement, outcome expectations, and perceived stress. The primary student participants in this study were first-year engineering students from underrepresented groups which include African American, Hispanic American students and women. With this in mind, the researcher sought to examine the interactive influence of race/ethnicity and gender based on the aforementioned social cognitive factors. Differences in academic performance (university GPA of first-year undergraduate engineering students) were analyzed by ethnicity and gender. There was a main effect for ethnicity only. Gender was found not to be significant. Hispanics were not found to be significantly different in their GPAs than Whites but Blacks were found to have lower GPAs than Whites. Also, Pearson correlation coefficients were used to examine the relationship between and among the nine identified social cognitive variables. The data from the analysis uncovered ten significant correlations which were as follows: occupational self-efficacy and academic self-efficacy, occupational self-efficacy and vocational interest, occupational self-efficacy and perceived stress, academic self-efficacy and encouragement, academic self-efficacy and outcome expectations, academic self-efficacy and perceived stress, vocational interest and outcome expectations, discouragement and encouragement, coping and perceived stress, outcome expectations and perceived stress. Next, a Pearson correlation coefficient was utilized to examine the relationship between academic performance (college GPA) of first-year undergraduate engineering students and the nine identified social cognitive variables. The data analysis revealed three significant correlations which were as follows academic performance and occupational self-efficacy, academic performance and academic self-efficacy, and academic performance and encouragement. Finally, a Pearson correlation coefficient was used to examine the relationship between high school GPA and the nine identified social cognitive variables. The Pearson correlational coefficient indicated that there was one statistically significant correlation which was high school GPA and academic self-efficacy. Recommendations for further study included (a) future research involving investigations that compare a variety of institutions in different regions of the country; (b) further investigations utilizing open-ended responses from engineering students based on interviews; (c) a replicated study in 5 to 10 years to evaluate whether differences emerged relating to ethnicity and gender due to possible societal or cultural changes; and (d) a study involving a pretest and posttest of students' self-efficacy beliefs. Finally, the researcher recommends a qualitative study specifically involving interview questions aimed at students with moderate level grades and SAT scores who exhibited above average academic performance. (Abstract shortened by UMI.).

Factors associated to quality of life in active elderly.

PubMed

Alexandre, Tiago da Silva; Cordeiro, Renata Cereda; Ramos, Luiz Roberto

2009-08-01

To analyze whether quality of life in active, healthy elderly individuals is influenced by functional status and sociodemographic characteristics, as well as psychological parameters. Study conducted in a sample of 120 active elderly subjects recruited from two open universities of the third age in the cities of São Paulo and São José dos Campos (Southeastern Brazil) between May 2005 and April 2006. Quality of life was measured using the abbreviated Brazilian version of the World Health Organization Quality of Live (WHOQOL-bref) questionnaire. Sociodemographic, clinical and functional variables were measured through crossculturally validated assessments by the Mini Mental State Examination, Geriatric Depression Scale, Functional Reach, One-Leg Balance Test, Timed Up and Go Test, Six-Minute Walk Test, Human Activity Profile and a complementary questionnaire. Simple descriptive analyses, Pearson's correlation coefficient, Student's t-test for non-related samples, analyses of variance, linear regression analyses and variance inflation factor were performed. The significance level for all statistical tests was set at 0.05. Linear regression analysis showed an independent correlation without colinearity between depressive symptoms measured by the Geriatric Depression Scale and four domains of the WHOQOL-bref. Not having a conjugal life implied greater perception in the social domain; developing leisure activities and having an income over five minimum wages implied greater perception in the environment domain. Functional status had no influence on the Quality of Life variable in the analysis models in active elderly. In contrast, psychological factors, as assessed by the Geriatric Depression Scale, and sociodemographic characteristics, such as marital status, income and leisure activities, had an impact on quality of life.

Does herpes zoster predispose to giant cell arteritis: a geo-epidemiologic study

PubMed Central

Ing, Edsel B; Ing, Royce; Liu, Xinyang; Zhang, Angela; Torun, Nurhan; Sey, Michael; Pagnoux, Christian

2018-01-01

Purpose Giant cell arteritis (GCA) is the most common systemic vasculitis in the elderly and can cause irreversible blindness and aortitis. Varicella zoster (VZ), which is potentially preventable by vaccination, has been proposed as a possible immune trigger for GCA, but this is controversial. The incidence of GCA varies widely by country. If VZ virus contributes to the immunopathogenesis of GCA we hypothesized that nations with increased incidence of GCA would also have increased incidence of herpes zoster (HZ). We conducted an ecologic analysis to determine the relationship between the incidence of HZ and GCA in different countries. Methods A literature search for the incidence rates (IRs) of GCA and HZ from different countries was conducted. Correlation and linear regression was performed comparing the disease IR of each country for subjects 50 years of age or older. Results We found the IR for GCA and HZ from 14 countries. Comparing the IRs for GCA and HZ in 50-year-olds, the Pearson product-moment correlation (r) was −0.51, with linear regression coefficient (β) −2.92 (95% CI −5.41, −0.43; p=0.025) using robust standard errors. Comparing the IRs for GCA and HZ in 70-year-olds, r was −0.40, with β −1.78, which was not statistically significant (95% CI −4.10, 0.53; p=0.12). Conclusion Although this geo-epidemiologic study has potential for aggregation and selection biases, there was no positive biologic gradient between the incidence of clinically evident HZ and GCA. PMID:29391771

Healthcare waste management during disasters and its effects on climate change: Lessons from 2010 earthquake and cholera tragedies in Haiti.

PubMed

Raila, Emilia M; Anderson, David O

2017-03-01

Despite growing effects of human activities on climate change throughout the world, and global South in particular, scientists are yet to understand how poor healthcare waste management practices in an emergency influences the climate change. This article presents new findings on climate change risks of healthcare waste disposal during and after the 2010 earthquake and cholera disasters in Haiti. The researchers analysed quantities of healthcare waste incinerated by the United Nations Mission in Haiti for 60 months (2009 to 2013). The aim was to determine the relationship between healthcare waste incinerated weights and the time of occurrence of the two disasters, and associated climate change effects, if any. Pearson product-moment correlation coefficient indicated a weak correlation between the quantities of healthcare waste disposed of and the time of occurrence of the actual emergencies (r (58) = 0.406, p = 0.001). Correspondingly, linear regression analysis indicated a relatively linear data trend (R 2 = 0.16, F (1, 58) = 11.42, P = 0.001) with fluctuating scenarios that depicted a sharp rise in 2012, and time series model showed monthly and yearly variations within 60 months. Given that the peak healthcare waste incineration occurred 2 years after the 2010 disasters, points at the need to minimise wastage on pharmaceuticals by improving logistics management. The Government of Haiti had no data on healthcare waste disposal and practised smoky open burning, thus a need for capacity building on green healthcare waste management technologies for effective climate change mitigation.

[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.

Association between cell-bound blood amyloid-β(1-40) levels and hippocampus volume.

PubMed

Sotolongo-Grau, Oscar; Pesini, Pedro; Valero, Sergi; Lafuente, Asunción; Buendía, Mar; Pérez-Grijalba, Virginia; José, Itziar San; Ibarria, Marta; Tejero, Miguel A; Giménez, Joan; Hernández, Isabel; Tárraga, Lluís; Ruiz, Agustín; Boada, Mercé; Sarasa, Manuel

2014-01-01

The identification of early, preferably presymptomatic, biomarkers and true etiologic factors for Alzheimer's disease (AD) is the first step toward establishing effective primary and secondary prevention programs. Consequently, the search for a relatively inexpensive and harmless biomarker for AD continues. Despite intensive research worldwide, to date there is no definitive plasma or blood biomarker indicating high or low risk of conversion to AD. Magnetic resonance imaging and β-amyloid (Aβ) levels in three blood compartments (diluted in plasma, undiluted in plasma and cell-bound) were measured in 96 subjects (33 with mild cognitive impairment, 14 with AD and 49 healthy controls). Pearson correlations were completed between 113 regions of interest (ROIs) (45 subcortical and 68 cortical) and Aβ levels. Pearson correlation analyses adjusted for the covariates age, sex, apolipoprotein E (ApoE), education and creatinine levels showed neuroimaging ROIs were associated with Aβ levels. Two statistical methods were applied to study the major relationships identified: (1) Pearson correlation with phenotype added as a covariate and (2) a meta-analysis stratified by phenotype. Neuroimaging data and plasma Aβ measurements were taken from 630 Alzheimer's Disease Neuroimaging Initiative (ADNI) subjects to be compared with our results. The left hippocampus was the brain region most correlated with Aβ(1-40) bound to blood cell pellets (partial correlation (pcor) = -0.37, P = 0.0007) after adjustment for the covariates age, gender and education, ApoE and creatinine levels. The correlation remained almost the same (pcor = -0.35, P = 0.002) if phenotype is also added as a covariate. The association between both measurements was independent of cognitive status. The left hemisphere entorhinal cortex also correlated with Aβ(1-40) cell-bound fraction. AB128 and ADNI plasma Aβ measurements were not related to any brain morphometric measurement. Association of cell-bound Aβ(1-40) in blood with left hippocampal volume was much stronger than previously observed in Aβ plasma fractions. If confirmed, this observation will require careful interpretation and must be taken into account for blood amyloid-based biomarker development.

Predicting Reactive Intermediate Quantum Yields from Dissolved Organic Matter Photolysis Using Optical Properties and Antioxidant Capacity.

PubMed

Mckay, Garrett; Huang, Wenxi; Romera-Castillo, Cristina; Crouch, Jenna E; Rosario-Ortiz, Fernando L; Jaffé, Rudolf

2017-05-16

The antioxidant capacity and formation of photochemically produced reactive intermediates (RI) was studied for water samples collected from the Florida Everglades with different spatial (marsh versus estuarine) and temporal (wet versus dry season) characteristics. Measured RI included triplet excited states of dissolved organic matter ( 3 DOM*), singlet oxygen ( 1 O 2 ), and the hydroxyl radical ( • OH). Single and multiple linear regression modeling were performed using a broad range of extrinsic (to predict RI formation rates, R RI ) and intrinsic (to predict RI quantum yields, Φ RI ) parameters. Multiple linear regression models consistently led to better predictions of R RI and Φ RI for our data set but poor prediction of Φ RI for a previously published data set,1 probably because the predictors are intercorrelated (Pearson's r > 0.5). Single linear regression models were built with data compiled from previously published studies (n ≈ 120) in which E2:E3, S, and Φ RI values were measured, which revealed a high degree of similarity between RI-optical property relationships across DOM samples of diverse sources. This study reveals that • OH formation is, in general, decoupled from 3 DOM* and 1 O 2 formation, providing supporting evidence that 3 DOM* is not a • OH precursor. Finally, Φ RI for 1 O 2 and 3 DOM* correlated negatively with antioxidant activity (a surrogate for electron donating capacity) for the collected samples, which is consistent with intramolecular oxidation of DOM moieties by 3 DOM*.

Decisional balance and self-efficacy of physical activity among the elderly in Rasht in 2013 based on the transtheoretical model

PubMed Central

Abbaspour, Seddigheh; Farmanbar, Rabiollah; Njafi, Fateme; Ghiasvand, Arezoo Mohamadkhani; Dehghankar, Leila

2017-01-01

Background Regular physical activity has been considered as health promotion, and identifying different effective psycho-social variables on physical has proven to be essential. Objective To identify the relationship between decisional balance and self-efficacy in physical activities using the transtheoretical model in the members of a retirement center in Rasht, Guillen. Methods A descriptive cross-sectional study was conducted in 2013 by using convenient sampling on 262 elderly people who are the members of retirement centers in Rasht. Data were collected using Stages of change, Decisional balance, Self-efficacy and Physical Activity Scale for the Elderly (PASE). Data was analyzed using SPSS-16 software, descriptive and analytic statistic (Pearson correlation, Spearman, ANOVA, HSD Tukey, linear and ordinal regression). Results The majority of participants were in maintenance stage. Mean and standard deviation physical activity for the elderly was 119.35±51.50. Stages of change and physical activities were significantly associated with decisional balance and self-efficacy (p<0.0001); however, cons had a significant and reverse association. According to linear and ordinal regression the only predicator variable of physical activity behavior was self-efficacy. Conclusion By increase in pros and self-efficacy on doing physical activity, it can be benefited in designing appropriate intervention programs. PMID:28713520

Determination of the efficiency of diets for larval development in mass rearing Aedes aegypti (Diptera: Culicidae).

PubMed

Gunathilaka, P A D H N; Uduwawala, U M H U; Udayanga, N W B A L; Ranathunge, R M T B; Amarasinghe, L D; Abeyewickreme, W

2017-11-23

Larval diet quality and rearing conditions have a direct and irreversible effect on adult traits. Therefore, the current study was carried out to optimize the larval diet for mass rearing of Aedes aegypti, for Sterile Insect Technique (SIT)-based applications in Sri Lanka. Five batches of 750 first instar larvae (L 1) of Ae. aegypti were exposed to five different concentrations (2-10%) of International Atomic Energy Agency (IAEA) recommended the larval diet. Morphological development parameters of larva, pupa, and adult were detected at 24 h intervals along with selected growth parameters. Each experiment was replicated five times. General Linear Modeling along with Pearson's correlation analysis were used for statistical treatments. Significant differences (P < 0.05) among the larvae treated with different concentrations were found using General Linear Modeling in all the stages namely: total body length and the thoracic length of larvae; cephalothoracic length and width of pupae; thoracic length, thoracic width, abdominal length and the wing length of adults; along with pupation rate and success, sex ratio, adult success, fecundity and hatching rate of Ae. aegypti. The best quality adults can be produced at larval diet concentration of 10%. However, the 8% larval diet concentration was most suitable for adult male survival.

Association between Organizational Commitment and Personality Traits of Faculty Members of Ahvaz Jundishapur University of Medical Sciences.

PubMed

Khiavi, Farzad Faraji; Dashti, Rezvan; Mokhtari, Saeedeh

2016-03-01

Individual characteristics are important factors influencing organizational commitment. Also, committed human resources can lead organizations to performance improvement as well as personal and organizational achievements. This research aimed to determine the association between organizational commitment and personality traits among faculty members of Ahvaz Jundishapur University of Medical Sciences. the research population of this cross-sectional study was the faculty members of Ahvaz Jundishapur University of Medical Sciences (Ahvaz, Iran). The sample size was determined to be 83. Data collection instruments were the Allen and Meyer questionnaire for organizational commitment and Neo for characteristics' features. The data were analyzed through Pearson's product-moment correlation and the independent samples t-test, ANOVA, and simple linear regression analysis (SLR) by SPSS. Continuance commitment showed a significant positive association with neuroticism, extroversion, agreeableness, and conscientiousness. Normative commitment showed a significant positive association with conscientiousness and a negative association with extroversion (p = 0.001). Openness had a positive association with affective commitment. Openness and agreeableness, among the five characteristics' features, had the most effect on organizational commitment, as indicated by simple linear regression analysis. Faculty members' characteristics showed a significant association with their organizational commitment. Determining appropriate characteristic criteria for faculty members may lead to employing committed personnel to accomplish the University's objectives and tasks.

Translation and validation of the Rhinosinusitis Disability Index for use in Nigeria.

PubMed

Asoegwu, C N; Nwawolo, C C; Okubadejo, N U

2017-07-01

The Rhinosinusitis Disability Index (RSDI) is a validated and reliable measure of severity of chronic rhinosinusitis. The objective of this study was to translate and validate the instrument for use in Nigeria. This is a methodological study. 71 patients with chronic rhinosinusitis attending two Otolaryngology clinics in Lagos, Nigeria. Using standardized methods and trained translators, the RSDI was translated to vernacular (Yoruba language) and back-translated to culturally appropriate English. Data analysis comprised of assessment of the item quality, content validity and internal consistency of the back-translated Rhinosinusitis Disability Index (bRSDI), and correlation to the original RSDI. Content validity (floor and ceiling effects) showed 0% floor and ceiling effects for the total scores, 0% ceiling effects for all domains and floor effect for physical domain, and 9.9 and 8.5% floor effects for functional and emotional domains, respectively. The mean item-own correlation for physical domain was 0.54 ± 0.08, 0.72 ± 0.08 for functional domain and 0.74 ± 0.07 for emotional domain. All domain item-own correlations were higher than item-other domain correlations. The total Cronbach's alpha was 0.936 and was higher than 0.70 for all the domains representing good internal consistency. Pearson correlation analysis showed strong correlation of RSDI to bRSDI (total score 0.881; p = 0.000, and domain subscores-physical: 0.788; p = 0.000, functional: 0.830; p = 0.000, and emotional: 0.888; p = 0.000). The back-translated Rhinosinusitis Disability Index shows good face and content validity with good internal consistency while correlating linearly and significantly with the original Rhinosinusitis Disability Index and is recommended for use in Nigeria.

Validating hospital antibiotic purchasing data as a metric of inpatient antibiotic use.

PubMed

Tan, Charlie; Ritchie, Michael; Alldred, Jason; Daneman, Nick

2016-02-01

Antibiotic purchasing data are a widely used, but unsubstantiated, measure of antibiotic consumption. To validate this source, we compared purchasing data from hospitals and external medical databases with patient-level dispensing data. Antibiotic purchasing and dispensing data from internal hospital records and purchasing data from IMS Health were obtained for two hospitals between May 2013 and April 2015. Internal purchasing data were validated against dispensing data, and IMS data were compared with both internal metrics. Scatterplots of individual antimicrobial data points were generated; Pearson's correlation and linear regression coefficients were computed. A secondary analysis re-examined these correlations over shorter calendar periods. Internal purchasing data were strongly correlated with dispensing data, with correlation coefficients of 0.90 (95% CI = 0.83-0.95) and 0.98 (95% CI = 0.95-0.99) at hospitals A and B, respectively. Although dispensing data were consistently lower than purchasing data, this was attributed to a single antibiotic at both hospitals. IMS data were favourably correlated with, but underestimated, internal purchasing and dispensing data. This difference was accounted for by eight antibiotics for which direct sales from some manufacturers were not included in the IMS database. The correlation between purchasing and dispensing data was consistent across periods as short as 3 months, but not at monthly intervals. Both internal and external antibiotic purchasing data are strongly correlated with dispensing data. If outliers are accounted for appropriately, internal purchasing data could be used for cost-effective evaluation of antimicrobial stewardship programmes, and external data sets could be used for surveillance and research across geographical regions. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Validating hospital antibiotic purchasing data as a metric of inpatient antibiotic use

PubMed Central

Tan, Charlie; Ritchie, Michael; Alldred, Jason; Daneman, Nick

2016-01-01

Objectives Antibiotic purchasing data are a widely used, but unsubstantiated, measure of antibiotic consumption. To validate this source, we compared purchasing data from hospitals and external medical databases with patient-level dispensing data. Methods Antibiotic purchasing and dispensing data from internal hospital records and purchasing data from IMS Health were obtained for two hospitals between May 2013 and April 2015. Internal purchasing data were validated against dispensing data, and IMS data were compared with both internal metrics. Scatterplots of individual antimicrobial data points were generated; Pearson's correlation and linear regression coefficients were computed. A secondary analysis re-examined these correlations over shorter calendar periods. Results Internal purchasing data were strongly correlated with dispensing data, with correlation coefficients of 0.90 (95% CI = 0.83–0.95) and 0.98 (95% CI = 0.95–0.99) at hospitals A and B, respectively. Although dispensing data were consistently lower than purchasing data, this was attributed to a single antibiotic at both hospitals. IMS data were favourably correlated with, but underestimated, internal purchasing and dispensing data. This difference was accounted for by eight antibiotics for which direct sales from some manufacturers were not included in the IMS database. The correlation between purchasing and dispensing data was consistent across periods as short as 3 months, but not at monthly intervals. Conclusions Both internal and external antibiotic purchasing data are strongly correlated with dispensing data. If outliers are accounted for appropriately, internal purchasing data could be used for cost-effective evaluation of antimicrobial stewardship programmes, and external data sets could be used for surveillance and research across geographical regions. PMID:26546668

The Effect of Patient Age on Standardized, Uptake Value-Hounsfield Unit Values of Male Genitourinery Structures In F-18 FDG PET/CT

PubMed Central

Çavuşoğlu, Berrin; Durak, Hatice

2011-01-01

Objective: Relation between patient age and Hounsfield Unit (HU),which is the linear attenuation coefficient, and Standardized Uptake Values (SUV) which is the amount of 18F-fluorodeoxyglucose (F-18 FDG) uptake, measured in the areas of interest drawn to prostate, seminal vesicles and testicles in F-18 FDG Positron Emission Tomography/Computed Tomography (PET/CT) images was investigated. Material and Methods: Mean and maximum SUV and HU values were recorded from the areas of interest (min 12 mm in diameter) which showed FDG uptake in prostate, seminal vesicles and testicles from F-18 FDG PET-CT images of 21 male patients under 40 years without genitourinary cancer. The effect of patient age to SUV and HU values was examined with Pearson correlation test using SPSS program. Results: There was a negative insignificant correlation between patient age and SUV and HU values for prostate. For seminal vesicles, correlation between patient age and SUV values and HUmax were positive but insignificant, while correlation with HUmean was significant (r=0.459, p=0.00). Correlation between patient age and SUVmax and SUVmean values were significant for testicles (r=0.506, p=0.002 and r=0.467, p=0.005, respectively) but the correlation between patient age and HUmax and HUmean values was not significant. Conclusion: F-18 FDG uptake in testicles in males increases with age until 40, suggesting an increase in metabolic rate. The significant correlation between age and mean HU values is probably caused by thickening of the tissue without an increase in glucose metabolism in seminal vesicles. In prostate, the effect of patient age to SUV and HU values was not observed until the age 40. Conflict of interest:None declared. PMID:23486855

Body adiposity index (BAI) correlates with BMI and body fat pre- and post-bariatric surgery but is not an adequate substitute for BMI in severely obese women.

PubMed

Gibson, C D; Atalayer, D; Flancbaum, L; Geliebter, A

2012-01-01

OBJECTIVE: Body Adiposity Index (BAI), a new surrogate measure of body fat (hip circumference/[height 1.5-18]), has been proposed as a more accurate alternative to BMI. We compared BAI with BMI and their correlations with measures of body fat, waist circumference (WC), and indirect indices of fat pre- and post-Roux-en-Y gastric bypass (RYGB). METHODS: Sixteen clinically severe obese (CSO) non-diabetic women (age = 33.9± 7.9 SD; BMI = 46.5±9.5 kg/m(2)) were assessed pre-surgery, and at 2 (n=9) and 5 mo (n=8) post-surgery. Body fat percentage (% fat) was estimated with bioimpedance analysis (BIA), air displacement plethysmography (ADP), and dual-energy x-ray absorptiometry (DXA). WC, an indicator of central fat, and both plasma leptin (ng/ml) and insulin (mU/l) concentrations were measured as indirect body fat indices. Pre- and post-surgery values were analyzed with Pearson correlations and linear regressions. RESULTS: BAI and BMI correlated significantly with each other pre-surgery and at each time point post surgery. BAI and BMI also correlated significantly with % fat from BIA and ADP; however, only BMI correlated significantly with % fat from DXA pre- and post-RYGB. BMI was the single best predictor of WC and leptin at 2 and 5 mo post-surgery and had significant longitudinal changes correlating with % fat from BIA and DXA as well as with leptin. DISCUSSION: Both BAI and BMI were good surrogates of % fat as estimated from BIA and ADP, but only BMI was a good surrogate of % fat from DXA in CSO women. Thus, BAI may not be a better alternative to BMI.

The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis.

PubMed

Easter, Sarah Rae; Robinson, Julian N; Carusi, Daniela; Little, Sarah E

2018-03-01

 The objective of this study was to test whether hospitals experienced in twin delivery have lower rates of cesarean delivery for twins.  We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean delivery rate to its overall cesarean delivery and vaginal birth after cesarean (VBAC) rates.  Annual twin delivery volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean delivery were independent of delivery volume with a rate of 75.5 versus 74.8% in the lowest and highest volume hospitals ( p  = 0.09 across quartiles). A hospital's cesarean delivery rate for twins moderately correlated with the overall cesarean rate ( r  = 0.52, p  < 0.01) and inversely correlated with VBAC rate ( r  =  - 0.42, p  < 0.01).  Most U.S. obstetrical units perform a low volume of twin deliveries with no decrease in cesarean delivery rates at higher volume hospitals. Twin cesarean delivery rates correlate with other obstetric parameters such as singleton cesarean delivery and VBAC rates suggesting twin cesarean delivery rate is more closely related to a hospital's general obstetric practice than its twin delivery volume. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Anticipation, Teamwork, and Cognitive Load: Chasing Efficiency during Robot-Assisted Surgery

PubMed Central

Sexton, Kevin; Johnson, Amanda; Gotsch, Amanda; Hussein, Ahmed A.; Cavuoto, Lora; Guru, Khurshid A.

2018-01-01

Introduction Robot-assisted surgery (RAS) has changed the traditional operating room, occupying more space with equipment and isolating console surgeons away from the patients and their team. We aimed to evaluate how anticipation of surgical steps and familiarity between team members impacted efficiency and safety. Methods We analyzed recordings (video and audio) of 12 robot-assisted radical prostatectomies. Any requests between surgeon and the team members were documented and classified by personnel, equipment type, mode of communication, level of inconvenience in fulfilling the request, and anticipation. Surgical team members completed questionnaires assessing team familiarity and cognitive load (NASA-TLX). Predictors of team efficiency were assessed using Pearson correlation and stepwise linear regression. Results 1330 requests were documented of which 413 (31%) were anticipated. Anticipation correlated negatively with operative time resulting in overall 8% reduction of OR time. Team familiarity negatively correlated with inconveniences. Anticipation ratio, percent of requests that were nonverbal, and total request duration were significantly correlated with the console surgeons’ cognitive load (r=0.77, p=0.006; r=0.63, p=0.04; and r=0.70, p=0.02, respectively). Conclusions Anticipation and active engagement by the surgical team resulted in shorter operative time; and higher familiarity scores were associated with fewer inconveniences. Less anticipation and nonverbal requests were also associated with lower cognitive load for the console surgeon. Training efforts to increase anticipation and team familiarity can improve team efficiency during RAS. PMID:28689193

Cognition in multiple sclerosis: Between cognitive reserve and brain volume.

PubMed

Fenu, G; Lorefice, L; Arru, M; Sechi, V; Loi, L; Contu, F; Cabras, F; Coghe, G; Frau, J; Fronza, M; Sbrescia, G; Lai, V; Boi, M; Mallus, S; Murru, S; Porcu, A; Barracciu, M A; Marrosu, M G; Cocco, E

2018-03-15

Several correlations between cognitive impairment (CI), radiologic markers and cognitive reserve (CR) have been documented in MS. To evaluate correlation between CI and brain volume (BV) considering CR as possibile mitigating factor. 195 relapsing MS patients underwent a neuropsychological assessment using BICAMS. BV was estimated using SIENAX to obtain normalized volume of brain (NBV), white matter (NWV), gray matter (NGV) and cortical gray matter (CGV). CR was estimated using a previously validated tool. Pearson test showed a correlation between the symbol digit modality test (SDMT) score and NBV (r=0.38; p<0.000) NGV(r=0.31; p<0.000), CGV (r=0.35; p<0.000) and CRI score(r=0.42; p<0.000). Linear regression (dependent variable:SDMT) showed a relationship with CR scores (p=0.000) and NGV(p<0.000). A difference was detected between cognitive impaired and preserved patients regarding mean of NBV(p=0.002), NGV(p=0.007), CGV(p=0.002) and CR Scores (p=0.007). Anova showed a association between the presence of CI (dependent variable) and the interaction term CRIQ × CGV (p=0.004) whit adjustment for age and disability evaluated by EDSS. Our study shows a correlation between cognition and BV, in particular gray matter volume. Cognitive reserve is also confirmed as an important element playing a role in the complex interaction to determine the cognitive functions in MS. Copyright © 2018 Elsevier B.V. All rights reserved.

What Is the Role of Apelin regarding Cardiovascular Risk and Progression of Renal Disease in Type 2 Diabetic Patients with Diabetic Nephropathy?

PubMed Central

Fragoso, André; Silva, Claudia; Viegas, Carla; Tavares, Nelson; Guilherme, Patrícia; Santos, Nélio; Rato, Fátima; Camacho, Ana; Cavaco, Cidália; Pereira, Victor; Faísca, Marilia; Ataíde, João; Jesus, Ilídio; Neves, Pedro

2013-01-01

Aims. To evaluate the association of different apelin levels with cardiovascular mortality, hospitalization, renal function, and cardiovascular risk factors in type 2 diabetic patients with mild to moderate CKD. Methods. An observational, prospective study involving 150 patients divided into groups according to baseline apelin levels: 1 ≤ 98 pg/mL, 2 = 98–328 pg/mL, and 3 ≥ 329 pg/mL. Baseline characteristics were analyzed and compared. Multivariate Cox regression was used to find out predictors of cardiovascular mortality, and multivariate logistic regression was used to find out predictors of hospitalization and disease progression. Simple linear regressions and Pearson correlations were used to investigate correlations between apelin and renal disease and cardiovascular risk factors. Results. Patients' survival at 83 months in groups 1, 2, and 3 was 39%, 40%, and 71.2%, respectively (P = 0.046). Apelin, age, and eGFR were independent predictors of mortality, and apelin, creatinine, eGFR, resistin, and visfatin were independent predictors of hospitalization. Apelin levels were negatively correlated with cardiovascular risk factors and positively correlated with eGFR. Patients with lower apelin levels were more likely to start a depurative technique. Conclusions. Apelin levels might have a significant clinical use as a marker/predictor of cardiovascular mortality and hospitalization or even as a therapeutic agent for CKD patients with cardiovascular disease. PMID:24089668

Accuracy of a Radiological Evaluation Method for Thoracic and Lumbar Spinal Curvatures Using Spinous Processes.

PubMed

Marchetti, Bárbara V; Candotti, Cláudia T; Raupp, Eduardo G; Oliveira, Eduardo B C; Furlanetto, Tássia S; Loss, Jefferson F

The purpose of this study was to assess a radiographic method for spinal curvature evaluation in children, based on spinous processes, and identify its normality limits. The sample consisted of 90 radiographic examinations of the spines of children in the sagittal plane. Thoracic and lumbar curvatures were evaluated using angular (apex angle [AA]) and linear (sagittal arrow [SA]) measurements based on the spinous processes. The same curvatures were also evaluated using the Cobb angle (CA) method, which is considered the gold standard. For concurrent validity (AA vs CA), Pearson's product-moment correlation coefficient, root-mean-square error, Pitman- Morgan test, and Bland-Altman analysis were used. For reproducibility (AA, SA, and CA), the intraclass correlation coefficient, standard error of measurement, and minimal detectable change measurements were used. A significant correlation was found between CA and AA measurements, as was a low root-mean-square error. The mean difference between the measurements was 0° for thoracic and lumbar curvatures, and the mean standard deviations of the differences were ±5.9° and 6.9°, respectively. The intraclass correlation coefficients of AA and SA were similar to or higher than the gold standard (CA). The standard error of measurement and minimal detectable change of the AA were always lower than the CA. This study determined the concurrent validity, as well as intra- and interrater reproducibility, of the radiographic measurements of kyphosis and lordosis in children. Copyright © 2017. Published by Elsevier Inc.

Lower Hybrid Frequency Range Waves Generated by Ion Polarization Drift Due to Electromagnetic Ion Cyclotron Waves: Analysis of an Event Observed by the Van Allen Probe B

NASA Technical Reports Server (NTRS)

Khazanov, G. V.; Boardsen, S.; Krivorutsky, E. N.; Engebretson, M. J.; Sibeck, D.; Chen, S.; Breneman, A.

2017-01-01

We analyze a wave event that occurred near noon between 07:03 and 07:08 UT on 23 February 2014 detected by the Van Allen Probes B spacecraft, where waves in the lower hybrid frequency range (LHFR) and electromagnetic ion cyclotron (EMIC) waves are observed to be highly correlated, with Pearson correlation coefficient of approximately 0.86. We assume that the correlation is the result of LHFR wave generation by the ions polarization drift in the electric field of the EMIC waves. To check this assumption the drift velocities of electrons and H+, He+, and O+ ions in the measured EMIC wave electric field were modeled. Then the LHFR wave linear instantaneous growth rates for plasma with these changing drift velocities and different plasma compositions were calculated. The time distribution of these growth rates, their frequency distribution, and the frequency dependence of the ratio of the LHFR wave power spectral density (PSD)parallel and perpendicular to the ambient magnetic eld to the total PSD were found. These characteristics of the growth rates were compared with the corresponding characteristics of the observed LHFR activity. Reasonable agreement between these features and the strong correlation between EMIC and LHFR energy densities support the assumption that the LHFR wave generation can be caused by the ions polarization drift in the electric field of an EMIC wave.

[Dose-Response Dependences for Frequency of RET/PTC Gene Rearrangements in Papillary Thyroid Carcinoma after Irradiation. Simple Pooling Analysis of Molecular Epidemiological Data].

PubMed

Koterov, A N; Ushenkova, L N; Biryukov, A P

2016-01-01

On the basis of all possible publications on the theme included in the previously formed base of sources on molecular epidemiology of RET/PTC rearrangements in thyroid papillary carcinoma a pooled analysis ("simple pooling data") on determination of the dose-effect dependences for RET/PTC frequency in radiogenic carcinomas of various irradiated groups was performed. (They are groups subjected to radiotherapeutic exposure, residents near the Chernobyl nuclear power plant (CNPP) and victims of nuclear bombing). The tendency to Pearson linear correlation (r = 0.746; p = 0.148) between the frequency of RET/PTC and the estimated dose on thyroid in the regions affected by the CNPP accident was revealed. But this tendency was recognized to be random owing to abnormally low values of the indicator for the most contaminated Gomel region. The method tentatively called "case-control" showed reliable differences in thyroid dose values for carcinomas with RET/PTC and without those. The versatility of changes was found: the lack of RET/PTC for radiotherapeutic impacts was associated with higher doses, whereas in case of the CNPP accident and for nuclear bombing victims it was the opposite. Probably, in the first case the "cellular cleaning" phenomenon after exposure to very high doses took place. Search of direct Pearson correlations between average/median thyroid doses on groups and RET/PTC frequency in carcinomas of these groups showed a high reliability for the dose-effect dependences- at the continuous dose scale (for RET/PTC in total and RET/PTC1 respectively: r = 0.830; p = 0.002 and r = 0.906; p = 0.0003); while there was no significant correlation received for RET/PTC3. When using the weighting least square regression analysis (proceeding from the number of carcinomas in samples), the specified regularities remained. Attempts to influence the strength of correlation by exception ofthe data of all the samples connected with the accident on the CNPP did not significantly reduce the strength of associations for RET/PTC in total. On the basis of ordinal scale doses (background, "low" (0.1 Gy), "middle" (0.1-1 Gy) and "large" (1-10 Gy) dose) also found was a significant correlation (Spearman) with the dose for the frequency RET/PTC in total (r = 0.736; p = 0.0098), but for certain types of rearrangements the results were reverse to the previous analysis (the effect was significant only for the RET/PTC3: r = 0.731; p = 0.024). The linear dose-response trends of the Cochrane-Armitage-test for the frequency of RET/PTC in total, RET/PTC1 and RET/PTC3 depending on the dose to the thyroid in the ordinal scale were registered (p, respectively: < 0.0001 < 0.0001 and 0.007). Thus; after more than 20 years of the molecular and epidemiological research of RET/PTC in thyroid radiogenic carcinomas the comprehensive evidence of the dose-effect dependence existence indicating a real relationship between the studied parameters and a radiation factor was obtained for the first time.

Gradient approach to quantify the gradation smoothness for output media

NASA Astrophysics Data System (ADS)

Kim, Youn Jin; Bang, Yousun; Choh, Heui-Keun

2010-01-01

We aim to quantify the perception of color gradation smoothness using objectively measurable properties. We propose a model to compute the smoothness of hardcopy color-to-color gradations. It is a gradient-based method that can be determined as a function of the 95th percentile of second derivative for the tone-jump estimator and the fifth percentile of first derivative for the tone-clipping estimator. Performance of the model and a previously suggested method were psychophysically appreciated, and their prediction accuracies were compared to each other. Our model showed a stronger Pearson correlation to the corresponding visual data, and the magnitude of the Pearson correlation reached up to 0.87. Its statistical significance was verified through analysis of variance. Color variations of the representative memory colors-blue sky, green grass and Caucasian skin-were rendered as gradational scales and utilized as the test stimuli.

Validation of a New Metric for Assessing the Integration of Health Protection and Health Promotion in a Sample of Small- and Medium-Sized Employer Groups.

PubMed

Williams, Jessica A R; Nelson, Candace C; Cabán-Martinez, Alberto J; Katz, Jeffrey N; Wagner, Gregory R; Pronk, Nicolaas P; Sorensen, Glorian; McLellan, Deborah L

2015-09-01

To conduct validation analyses for a new measure of the integration of worksite health protection and health promotion approaches developed in earlier research. A survey of small- to medium-sized employers located in the United States was conducted between October 2013 and March 2014 (n = 111). Cronbach α coefficient was used to assess reliability, and Pearson correlation coefficients were used to assess convergent validity. The integration score was positively associated with the measures of occupational safety and health and health promotion activities/policies-supporting its convergent validity (Pearson correlation coefficients of 0.32 to 0.47). Cronbach α coefficient was 0.94, indicating excellent reliability. The integration score seems to be a promising tool for assessing integration of health promotion and health protection. Further work is needed to test its dimensionality and validate its use in other samples.

SPSS and SAS programs for comparing Pearson correlations and OLS regression coefficients.

PubMed

Weaver, Bruce; Wuensch, Karl L

2013-09-01

Several procedures that use summary data to test hypotheses about Pearson correlations and ordinary least squares regression coefficients have been described in various books and articles. To our knowledge, however, no single resource describes all of the most common tests. Furthermore, many of these tests have not yet been implemented in popular statistical software packages such as SPSS and SAS. In this article, we describe all of the most common tests and provide SPSS and SAS programs to perform them. When they are applicable, our code also computes 100 × (1 - α)% confidence intervals corresponding to the tests. For testing hypotheses about independent regression coefficients, we demonstrate one method that uses summary data and another that uses raw data (i.e., Potthoff analysis). When the raw data are available, the latter method is preferred, because use of summary data entails some loss of precision due to rounding.

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.

Burnout Syndrome Among Health Care Students: The Role of Type D Personality.

PubMed

Skodova, Zuzana; Lajciakova, Petra; Banovcinova, Lubica

2016-07-18

The aim of this study was to examine the effect of Type D personality, along with other personality traits (resilience and sense of coherence), on burnout syndrome and its counterpart, engagement, among students of nursing, midwifery, and psychology. A cross-sectional study was conducted on 97 university students (91.9% females; M age = 20.2 ± 1.49 years). A Type D personality subscale, School Burnout Inventory, Utrecht Work Engagement Scale, Sense of Coherence Questionnaire, and Baruth Protective Factor Inventory were used. Linear regression models, Student's t test, and Pearson's correlation analysis were employed. Negative affectivity, a dimension of Type D personality, was a significant personality predictor for burnout syndrome (β = .54; 95% CI = [0.33, 1.01]). The only significant personality predictor of engagement was a sense of coherence. Students who were identified as having Type D personality characteristics scored significantly higher on the burnout syndrome questionnaire (t = -2.58, p < .01). In health care professions, personality predictors should be addressed to prevent burnout. © The Author(s) 2016.

Analysis of the lateral push-off in the freestyle flip turn.

PubMed

Araujo, Luciana; Pereira, Suzana; Gatti, Roberta; Freitas, Elinai; Jacomel, Gabriel; Roesler, Helio; Villas-Boas, Joao

2010-09-01

The aim of this study was to examine the contact phase during the lateral push-off in the turn of front crawl swimming to determine which biomechanical variables (maximum normalized peak force, contact time, impulse, angle of knee flexion, and total turn time within 15 m) contribute to the performance of this turn technique. Thirty-four swimmers of state, national, and international competitive standard participated in the study. For data collection, the following equipment was used: an underwater force platform, a 30-Hz VHS video camera, and a MiniDv digital camera within an underwater box. Data are expressed as descriptive statistics. Inferential analyses were performed using Pearson's correlation and multiple linear regressions. All variables studied had a significant relationship with turn performance. We conclude that a turn executed with a knee flexion angle of between 100° and 120° provides optimum peak forces to generate impulses that allow the swimmer to lose less time in the turn without the need for an excessive force application and with less energy lost.

Extraversion, neuroticism and secondary trauma in Internet child abuse investigators

PubMed Central

2016-01-01

Background Working with victims and perpetrators of child sexual abuse has been shown to cause secondary traumatic stress (STS) in child protection professionals. Aims To examine the role of gender and personality on the development of secondary trauma responses. Methods A study of Internet child abuse investigators (ICAIs) from two UK police forces. Participants completed a personality test together with tests for anxiety, depression, burnout, STS and post-traumatic stress disorder to assess secondary trauma. The data were normally distributed and the results were analysed using an independent t-test, Pearson correlation and linear regression. Results Among 126 study subjects (50 females and 75 males), there was a higher incidence of STS in investigators who were female, introverted and neurotic. However, there were lower levels of STS in the participants in this study than those found in other studies. Conclusions Psychological screening and surveillance of ICAI teams can help to identify risk factors for the development of STS and identify where additional support may be required. PMID:26928859

Comprehensive model for predicting perceptual image quality of smart mobile devices.

PubMed

Gong, Rui; Xu, Haisong; Luo, M R; Li, Haifeng

2015-01-01

An image quality model for smart mobile devices was proposed based on visual assessments of several image quality attributes. A series of psychophysical experiments were carried out on two kinds of smart mobile devices, i.e., smart phones and tablet computers, in which naturalness, colorfulness, brightness, contrast, sharpness, clearness, and overall image quality were visually evaluated under three lighting environments via categorical judgment method for various application types of test images. On the basis of Pearson correlation coefficients and factor analysis, the overall image quality could first be predicted by its two constituent attributes with multiple linear regression functions for different types of images, respectively, and then the mathematical expressions were built to link the constituent image quality attributes with the physical parameters of smart mobile devices and image appearance factors. The procedure and algorithms were applicable to various smart mobile devices, different lighting conditions, and multiple types of images, and performance was verified by the visual data.

Principal component analysis and neurocomputing-based models for total ozone concentration over different urban regions of India

NASA Astrophysics Data System (ADS)

Chattopadhyay, Goutami; Chattopadhyay, Surajit; Chakraborthy, Parthasarathi

2012-07-01

The present study deals with daily total ozone concentration time series over four metro cities of India namely Kolkata, Mumbai, Chennai, and New Delhi in the multivariate environment. Using the Kaiser-Meyer-Olkin measure, it is established that the data set under consideration are suitable for principal component analysis. Subsequently, by introducing rotated component matrix for the principal components, the predictors suitable for generating artificial neural network (ANN) for daily total ozone prediction are identified. The multicollinearity is removed in this way. Models of ANN in the form of multilayer perceptron trained through backpropagation learning are generated for all of the study zones, and the model outcomes are assessed statistically. Measuring various statistics like Pearson correlation coefficients, Willmott's indices, percentage errors of prediction, and mean absolute errors, it is observed that for Mumbai and Kolkata the proposed ANN model generates very good predictions. The results are supported by the linearly distributed coordinates in the scatterplots.