Regional L-Moment-Based Flood Frequency Analysis in the Upper Vistula River Basin, Poland

NASA Astrophysics Data System (ADS)

Rutkowska, A.; Żelazny, M.; Kohnová, S.; Łyp, M.; Banasik, K.

2017-02-01

The Upper Vistula River basin was divided into pooling groups with similar dimensionless frequency distributions of annual maximum river discharge. The cluster analysis and the Hosking and Wallis (HW) L-moment-based method were used to divide the set of 52 mid-sized catchments into disjoint clusters with similar morphometric, land use, and rainfall variables, and to test the homogeneity within clusters. Finally, three and four pooling groups were obtained alternatively. Two methods for identification of the regional distribution function were used, the HW method and the method of Kjeldsen and Prosdocimi based on a bivariate extension of the HW measure. Subsequently, the flood quantile estimates were calculated using the index flood method. The ordinary least squares (OLS) and the generalised least squares (GLS) regression techniques were used to relate the index flood to catchment characteristics. Predictive performance of the regression scheme for the southern part of the Upper Vistula River basin was improved by using GLS instead of OLS. The results of the study can be recommended for the estimation of flood quantiles at ungauged sites, in flood risk mapping applications, and in engineering hydrology to help design flood protection structures.

Independent contrasts and PGLS regression estimators are equivalent.

PubMed

Blomberg, Simon P; Lefevre, James G; Wells, Jessie A; Waterhouse, Mary

2012-05-01

We prove that the slope parameter of the ordinary least squares regression of phylogenetically independent contrasts (PICs) conducted through the origin is identical to the slope parameter of the method of generalized least squares (GLSs) regression under a Brownian motion model of evolution. This equivalence has several implications: 1. Understanding the structure of the linear model for GLS regression provides insight into when and why phylogeny is important in comparative studies. 2. The limitations of the PIC regression analysis are the same as the limitations of the GLS model. In particular, phylogenetic covariance applies only to the response variable in the regression and the explanatory variable should be regarded as fixed. Calculation of PICs for explanatory variables should be treated as a mathematical idiosyncrasy of the PIC regression algorithm. 3. Since the GLS estimator is the best linear unbiased estimator (BLUE), the slope parameter estimated using PICs is also BLUE. 4. If the slope is estimated using different branch lengths for the explanatory and response variables in the PIC algorithm, the estimator is no longer the BLUE, so this is not recommended. Finally, we discuss whether or not and how to accommodate phylogenetic covariance in regression analyses, particularly in relation to the problem of phylogenetic uncertainty. This discussion is from both frequentist and Bayesian perspectives.

Predicting seasonal influenza transmission using functional regression models with temporal dependence.

PubMed

Oviedo de la Fuente, Manuel; Febrero-Bande, Manuel; Muñoz, María Pilar; Domínguez, Àngela

2018-01-01

This paper proposes a novel approach that uses meteorological information to predict the incidence of influenza in Galicia (Spain). It extends the Generalized Least Squares (GLS) methods in the multivariate framework to functional regression models with dependent errors. These kinds of models are useful when the recent history of the incidence of influenza are readily unavailable (for instance, by delays on the communication with health informants) and the prediction must be constructed by correcting the temporal dependence of the residuals and using more accessible variables. A simulation study shows that the GLS estimators render better estimations of the parameters associated with the regression model than they do with the classical models. They obtain extremely good results from the predictive point of view and are competitive with the classical time series approach for the incidence of influenza. An iterative version of the GLS estimator (called iGLS) was also proposed that can help to model complicated dependence structures. For constructing the model, the distance correlation measure [Formula: see text] was employed to select relevant information to predict influenza rate mixing multivariate and functional variables. These kinds of models are extremely useful to health managers in allocating resources in advance to manage influenza epidemics.

Implementation of a computationally efficient least-squares algorithm for highly under-determined three-dimensional diffuse optical tomography problems.

PubMed

Yalavarthy, Phaneendra K; Lynch, Daniel R; Pogue, Brian W; Dehghani, Hamid; Paulsen, Keith D

2008-05-01

Three-dimensional (3D) diffuse optical tomography is known to be a nonlinear, ill-posed and sometimes under-determined problem, where regularization is added to the minimization to allow convergence to a unique solution. In this work, a generalized least-squares (GLS) minimization method was implemented, which employs weight matrices for both data-model misfit and optical properties to include their variances and covariances, using a computationally efficient scheme. This allows inversion of a matrix that is of a dimension dictated by the number of measurements, instead of by the number of imaging parameters. This increases the computation speed up to four times per iteration in most of the under-determined 3D imaging problems. An analytic derivation, using the Sherman-Morrison-Woodbury identity, is shown for this efficient alternative form and it is proven to be equivalent, not only analytically, but also numerically. Equivalent alternative forms for other minimization methods, like Levenberg-Marquardt (LM) and Tikhonov, are also derived. Three-dimensional reconstruction results indicate that the poor recovery of quantitatively accurate values in 3D optical images can also be a characteristic of the reconstruction algorithm, along with the target size. Interestingly, usage of GLS reconstruction methods reduces error in the periphery of the image, as expected, and improves by 20% the ability to quantify local interior regions in terms of the recovered optical contrast, as compared to LM methods. Characterization of detector photo-multiplier tubes noise has enabled the use of the GLS method for reconstructing experimental data and showed a promise for better quantification of target in 3D optical imaging. Use of these new alternative forms becomes effective when the ratio of the number of imaging property parameters exceeds the number of measurements by a factor greater than 2.

Topological and canonical kriging for design flood prediction in ungauged catchments: an improvement over a traditional regional regression approach?

USGS Publications Warehouse

Archfield, Stacey A.; Pugliese, Alessio; Castellarin, Attilio; Skøien, Jon O.; Kiang, Julie E.

2013-01-01

In the United States, estimation of flood frequency quantiles at ungauged locations has been largely based on regional regression techniques that relate measurable catchment descriptors to flood quantiles. More recently, spatial interpolation techniques of point data have been shown to be effective for predicting streamflow statistics (i.e., flood flows and low-flow indices) in ungauged catchments. Literature reports successful applications of two techniques, canonical kriging, CK (or physiographical-space-based interpolation, PSBI), and topological kriging, TK (or top-kriging). CK performs the spatial interpolation of the streamflow statistic of interest in the two-dimensional space of catchment descriptors. TK predicts the streamflow statistic along river networks taking both the catchment area and nested nature of catchments into account. It is of interest to understand how these spatial interpolation methods compare with generalized least squares (GLS) regression, one of the most common approaches to estimate flood quantiles at ungauged locations. By means of a leave-one-out cross-validation procedure, the performance of CK and TK was compared to GLS regression equations developed for the prediction of 10, 50, 100 and 500 yr floods for 61 streamgauges in the southeast United States. TK substantially outperforms GLS and CK for the study area, particularly for large catchments. The performance of TK over GLS highlights an important distinction between the treatments of spatial correlation when using regression-based or spatial interpolation methods to estimate flood quantiles at ungauged locations. The analysis also shows that coupling TK with CK slightly improves the performance of TK; however, the improvement is marginal when compared to the improvement in performance over GLS.

On the equivalence of generalized least-squares approaches to the evaluation of measurement comparisons

NASA Astrophysics Data System (ADS)

Koo, A.; Clare, J. F.

2012-06-01

Analysis of CIPM international comparisons is increasingly being carried out using a model-based approach that leads naturally to a generalized least-squares (GLS) solution. While this method offers the advantages of being easier to audit and having general applicability to any form of comparison protocol, there is a lack of consensus over aspects of its implementation. Two significant results are presented that show the equivalence of three differing approaches discussed by or applied in comparisons run by Consultative Committees of the CIPM. Both results depend on a mathematical condition equivalent to the requirement that any two artefacts in the comparison are linked through a sequence of measurements of overlapping pairs of artefacts. The first result is that a GLS estimator excluding all sources of error common to all measurements of a participant is equal to the GLS estimator incorporating all sources of error, including those associated with any bias in the standards or procedures of the measuring laboratory. The second result identifies the component of uncertainty in the estimate of bias that arises from possible systematic effects in the participants' measurement standards and procedures. The expression so obtained is a generalization of an expression previously published for a one-artefact comparison with no inter-participant correlations, to one for a comparison comprising any number of repeat measurements of multiple artefacts and allowing for inter-laboratory correlations.

Global longitudinal strain corrected by RR interval is a superior predictor of all-cause mortality in patients with systolic heart failure and atrial fibrillation.

PubMed

Modin, Daniel; Sengeløv, Morten; Jørgensen, Peter Godsk; Bruun, Niels Eske; Olsen, Flemming Javier; Dons, Maria; Fritz Hansen, Thomas; Jensen, Jan Skov; Biering-Sørensen, Tor

2018-04-01

Quantification of systolic function in patients with atrial fibrillation (AF) is challenging. A novel approach, based on RR interval correction, to counteract the varying heart cycle lengths in AF has recently been proposed. Whether this method is superior in patients with systolic heart failure (HFrEF) with AF remains unknown. This study investigates the prognostic value of RR interval-corrected peak global longitudinal strain {GLSc = GLS/[RR^(1/2)]} in relation to all-cause mortality in HFrEF patients displaying AF during echocardiographic examination. Echocardiograms from 151 patients with HFrEF and AF during examination were analysed offline. Peak global longitudinal strain (GLS) was averaged from 18 myocardial segments obtained from three apical views. GLS was indexed with the square root of the RR interval {GLSc = GLS/[RR^(1/2)]}. Endpoint was all-cause mortality. During a median follow-up of 2.7 years, 40 patients (26.5%) died. Neither uncorrected GLS (P = 0.056) nor left ventricular ejection fraction (P = 0.053) was significantly associated with all-cause mortality. After RR^(1/2) indexation, GLSc became a significant predictor of all-cause mortality (hazard ratio 1.16, 95% confidence interval 1.02-1.22, P = 0.014, per %/s^(1/2) decrease). GLSc remained an independent predictor of mortality after multivariable adjustment (age, sex, mean heart rate, mean arterial blood pressure, left atrial volume index, and E/e') (hazard ratio 1.17, 95% confidence interval 1.05-1.31, P = 0.005 per %/s^(1/2) decrease). Decreasing {GLSc = GLS/[RR^(1/2)]}, but not uncorrected GLS nor left ventricular ejection fraction, was significantly associated with increased risk of all-cause mortality in HFrEF patients with AF and remained an independent predictor after multivariable adjustment. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Validation of geometric accuracy of Global Land Survey (GLS) 2000 data

USGS Publications Warehouse

Rengarajan, Rajagopalan; Sampath, Aparajithan; Storey, James C.; Choate, Michael J.

2015-01-01

The Global Land Survey (GLS) 2000 data were generated from Geocover™ 2000 data with the aim of producing a global data set of accuracy better than 25 m Root Mean Square Error (RMSE). An assessment and validation of accuracy of GLS 2000 data set, and its co-registration with Geocover™ 2000 data set is presented here. Since the availability of global data sets that have higher nominal accuracy than the GLS 2000 is a concern, the data sets were assessed in three tiers. In the first tier, the data were compared with the Geocover™ 2000 data. This comparison provided a means of localizing regions of higher differences. In the second tier, the GLS 2000 data were compared with systematically corrected Landsat-7 scenes that were obtained in a time period when the spacecraft pointing information was extremely accurate. These comparisons localize regions where the data are consistently off, which may indicate regions of higher errors. The third tier consisted of comparing the GLS 2000 data against higher accuracy reference data. The reference data were the Digital Ortho Quads over the United States, orthorectified SPOT data over Australia, and high accuracy check points obtained using triangulation bundle adjustment of Landsat-7 images over selected sites around the world. The study reveals that the geometric errors in Geocover™ 2000 data have been rectified in GLS 2000 data, and that the accuracy of GLS 2000 data can be expected to be better than 25 m RMSE for most of its constituent scenes.

Geodesic least squares regression for scaling studies in magnetic confinement fusion

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

Verdoolaege, Geert

In regression analyses for deriving scaling laws that occur in various scientific disciplines, usually standard regression methods have been applied, of which ordinary least squares (OLS) is the most popular. However, concerns have been raised with respect to several assumptions underlying OLS in its application to scaling laws. We here discuss a new regression method that is robust in the presence of significant uncertainty on both the data and the regression model. The method, which we call geodesic least squares regression (GLS), is based on minimization of the Rao geodesic distance on a probabilistic manifold. We demonstrate the superiority ofmore » the method using synthetic data and we present an application to the scaling law for the power threshold for the transition to the high confinement regime in magnetic confinement fusion devices.« less

Estimating riparian understory vegetation cover with beta regression and copula models

USGS Publications Warehouse

Eskelson, Bianca N.I.; Madsen, Lisa; Hagar, Joan C.; Temesgen, Hailemariam

2011-01-01

Understory vegetation communities are critical components of forest ecosystems. As a result, the importance of modeling understory vegetation characteristics in forested landscapes has become more apparent. Abundance measures such as shrub cover are bounded between 0 and 1, exhibit heteroscedastic error variance, and are often subject to spatial dependence. These distributional features tend to be ignored when shrub cover data are analyzed. The beta distribution has been used successfully to describe the frequency distribution of vegetation cover. Beta regression models ignoring spatial dependence (BR) and accounting for spatial dependence (BRdep) were used to estimate percent shrub cover as a function of topographic conditions and overstory vegetation structure in riparian zones in western Oregon. The BR models showed poor explanatory power (pseudo-R2 ≤ 0.34) but outperformed ordinary least-squares (OLS) and generalized least-squares (GLS) regression models with logit-transformed response in terms of mean square prediction error and absolute bias. We introduce a copula (COP) model that is based on the beta distribution and accounts for spatial dependence. A simulation study was designed to illustrate the effects of incorrectly assuming normality, equal variance, and spatial independence. It showed that BR, BRdep, and COP models provide unbiased parameter estimates, whereas OLS and GLS models result in slightly biased estimates for two of the three parameters. On the basis of the simulation study, 93–97% of the GLS, BRdep, and COP confidence intervals covered the true parameters, whereas OLS and BR only resulted in 84–88% coverage, which demonstrated the superiority of GLS, BRdep, and COP over OLS and BR models in providing standard errors for the parameter estimates in the presence of spatial dependence.

The applicability of ordinary least squares to consistently short distances between taxa in phylogenetic tree construction and the normal distribution test consequences.

PubMed

Roux, C Z

2009-05-01

Short phylogenetic distances between taxa occur, for example, in studies on ribosomal RNA-genes with slow substitution rates. For consistently short distances, it is proved that in the completely singular limit of the covariance matrix ordinary least squares (OLS) estimates are minimum variance or best linear unbiased (BLU) estimates of phylogenetic tree branch lengths. Although OLS estimates are in this situation equal to generalized least squares (GLS) estimates, the GLS chi-square likelihood ratio test will be inapplicable as it is associated with zero degrees of freedom. Consequently, an OLS normal distribution test or an analogous bootstrap approach will provide optimal branch length tests of significance for consistently short phylogenetic distances. As the asymptotic covariances between branch lengths will be equal to zero, it follows that the product rule can be used in tree evaluation to calculate an approximate simultaneous confidence probability that all interior branches are positive.

Correlated Noise: How it Breaks NMF, and What to Do About It.

PubMed

Plis, Sergey M; Potluru, Vamsi K; Lane, Terran; Calhoun, Vince D

2011-01-12

Non-negative matrix factorization (NMF) is a problem of decomposing multivariate data into a set of features and their corresponding activations. When applied to experimental data, NMF has to cope with noise, which is often highly correlated. We show that correlated noise can break the Donoho and Stodden separability conditions of a dataset and a regular NMF algorithm will fail to decompose it, even when given freedom to be able to represent the noise as a separate feature. To cope with this issue, we present an algorithm for NMF with a generalized least squares objective function (glsNMF) and derive multiplicative updates for the method together with proving their convergence. The new algorithm successfully recovers the true representation from the noisy data. Robust performance can make glsNMF a valuable tool for analyzing empirical data.

Correlated Noise: How it Breaks NMF, and What to Do About It

PubMed Central

Plis, Sergey M.; Potluru, Vamsi K.; Lane, Terran; Calhoun, Vince D.

2010-01-01

Non-negative matrix factorization (NMF) is a problem of decomposing multivariate data into a set of features and their corresponding activations. When applied to experimental data, NMF has to cope with noise, which is often highly correlated. We show that correlated noise can break the Donoho and Stodden separability conditions of a dataset and a regular NMF algorithm will fail to decompose it, even when given freedom to be able to represent the noise as a separate feature. To cope with this issue, we present an algorithm for NMF with a generalized least squares objective function (glsNMF) and derive multiplicative updates for the method together with proving their convergence. The new algorithm successfully recovers the true representation from the noisy data. Robust performance can make glsNMF a valuable tool for analyzing empirical data. PMID:23750288

Effects of ketoconazole and rifampicin on the pharmacokinetics of GLS4, a novel anti-hepatitis B virus compound, in dogs

PubMed Central

Zhou, Xin; Gao, Zhi-wei; Meng, Jian; Chen, Xiao-yan; Zhong, Da-fang

2013-01-01

Aim: To investigate the metabolism of GLS4, a heteroaryldihydropyrimidine compound with anti-hepatitis B virus activity, in dog and human liver microsomes in vitro and evaluate the effects of ketoconazole (a potent CYP3A inhibitor) or rifampicin (a potent CYP3A inducer) on GLS4 pharmacokinetics in dogs. Methods: Dog and human liver microsomes and CYP3A4 were incubated with [14C]GLS4 for 15 min and then analyzed using a HPLC-dynamic online radio flow detection method. Two groups of beagle dogs were used for in vivo studies. Group A were orally administered a single dose of GLS4 (15 mg/kg) with or without ketoconazole pretreatment (100 mg/d for 8 consecutive days). Group B were orally administered a single dose of GLS4 (15 mg/kg) with or without rifampicin pretreatment (100 mg/d for 8 consecutive days). Plasma was sampled after GLS4 dosing. GLS4 concentrations were determined by HPLC-tandem mass spectrometry. Results: The metabolic profile of [14C]GLS4 in human and dog liver microsomes and CYP3A4 was similar. The major metabolites were morpholine N-dealkylated GLS4 and morpholine N,N-di-dealkylated GLS4. Pretreatment with ketoconazole or rifampicin significantly affected the plasma concentrations of GLS4 in dogs: ketoconazole increased the area under the concentration-time curve from 0 to infinity and peak concentration of GLS4 by 4.4 and 3.3 folds, respectively, whereas rifampicin decreased these parameters by 88.5% and 83.2%, respectively. Conclusion: GLS4 is a sensitive substrate of CYP3A. CYP3A inhibitors or inducers cause considerable change of GLS4 plasma concentrations in dogs, which should be considered in clinical practice. PMID:24056704

Comparing methods of analysing datasets with small clusters: case studies using four paediatric datasets.

PubMed

Marston, Louise; Peacock, Janet L; Yu, Keming; Brocklehurst, Peter; Calvert, Sandra A; Greenough, Anne; Marlow, Neil

2009-07-01

Studies of prematurely born infants contain a relatively large percentage of multiple births, so the resulting data have a hierarchical structure with small clusters of size 1, 2 or 3. Ignoring the clustering may lead to incorrect inferences. The aim of this study was to compare statistical methods which can be used to analyse such data: generalised estimating equations, multilevel models, multiple linear regression and logistic regression. Four datasets which differed in total size and in percentage of multiple births (n = 254, multiple 18%; n = 176, multiple 9%; n = 10 098, multiple 3%; n = 1585, multiple 8%) were analysed. With the continuous outcome, two-level models produced similar results in the larger dataset, while generalised least squares multilevel modelling (ML GLS 'xtreg' in Stata) and maximum likelihood multilevel modelling (ML MLE 'xtmixed' in Stata) produced divergent estimates using the smaller dataset. For the dichotomous outcome, most methods, except generalised least squares multilevel modelling (ML GH 'xtlogit' in Stata) gave similar odds ratios and 95% confidence intervals within datasets. For the continuous outcome, our results suggest using multilevel modelling. We conclude that generalised least squares multilevel modelling (ML GLS 'xtreg' in Stata) and maximum likelihood multilevel modelling (ML MLE 'xtmixed' in Stata) should be used with caution when the dataset is small. Where the outcome is dichotomous and there is a relatively large percentage of non-independent data, it is recommended that these are accounted for in analyses using logistic regression with adjusted standard errors or multilevel modelling. If, however, the dataset has a small percentage of clusters greater than size 1 (e.g. a population dataset of children where there are few multiples) there appears to be less need to adjust for clustering.

A rapid generalized least squares model for a genome-wide quantitative trait association analysis in families.

PubMed

Li, Xiang; Basu, Saonli; Miller, Michael B; Iacono, William G; McGue, Matt

2011-01-01

Genome-wide association studies (GWAS) using family data involve association analyses between hundreds of thousands of markers and a trait for a large number of related individuals. The correlations among relatives bring statistical and computational challenges when performing these large-scale association analyses. Recently, several rapid methods accounting for both within- and between-family variation have been proposed. However, these techniques mostly model the phenotypic similarities in terms of genetic relatedness. The familial resemblances in many family-based studies such as twin studies are not only due to the genetic relatedness, but also derive from shared environmental effects and assortative mating. In this paper, we propose 2 generalized least squares (GLS) models for rapid association analysis of family-based GWAS, which accommodate both genetic and environmental contributions to familial resemblance. In our first model, we estimated the joint genetic and environmental variations. In our second model, we estimated the genetic and environmental components separately. Through simulation studies, we demonstrated that our proposed approaches are more powerful and computationally efficient than a number of existing methods are. We show that estimating the residual variance-covariance matrix in the GLS models without SNP effects does not lead to an appreciable bias in the p values as long as the SNP effect is small (i.e. accounting for no more than 1% of trait variance). Copyright © 2011 S. Karger AG, Basel.

Effects of ketoconazole and rifampicin on the pharmacokinetics of GLS4, a novel anti-hepatitis B virus compound, in dogs.

PubMed

Zhou, Xin; Gao, Zhi-wei; Meng, Jian; Chen, Xiao-yan; Zhong, Da-fang

2013-11-01

To investigate the metabolism of GLS4, a heteroaryldihydropyrimidine compound with anti-hepatitis B virus activity, in dog and human liver microsomes in vitro and evaluate the effects of ketoconazole (a potent CYP3A inhibitor) or rifampicin (a potent CYP3A inducer) on GLS4 pharmacokinetics in dogs. Dog and human liver microsomes and CYP3A4 were incubated with [(14)C]GLS4 for 15 min and then analyzed using a HPLC-dynamic online radio flow detection method. Two groups of beagle dogs were used for in vivo studies. Group A were orally administered a single dose of GLS4 (15 mg/kg) with or without ketoconazole pretreatment (100 mg/d for 8 consecutive days). Group B were orally administered a single dose of GLS4 (15 mg/kg) with or without rifampicin pretreatment (100 mg/d for 8 consecutive days). Plasma was sampled after GLS4 dosing. GLS4 concentrations were determined by HPLC-tandem mass spectrometry. The metabolic profile of [(14)C]GLS4 in human and dog liver microsomes and CYP3A4 was similar. The major metabolites were morpholine N-dealkylated GLS4 and morpholine N,N-di-dealkylated GLS4. Pretreatment with ketoconazole or rifampicin significantly affected the plasma concentrations of GLS4 in dogs: ketoconazole increased the area under the concentration-time curve from 0 to infinity and peak concentration of GLS4 by 4.4 and 3.3 folds, respectively, whereas rifampicin decreased these parameters by 88.5% and 83.2%, respectively. GLS4 is a sensitive substrate of CYP3A. CYP3A inhibitors or inducers cause considerable change of GLS4 plasma concentrations in dogs, which should be considered in clinical practice.

Generalized Least Squares Estimators in the Analysis of Covariance Structures.

ERIC Educational Resources Information Center

Browne, Michael W.

This paper concerns situations in which a p x p covariance matrix is a function of an unknown q x 1 parameter vector y-sub-o. Notation is defined in the second section, and some algebraic results used in subsequent sections are given. Section 3 deals with asymptotic properties of generalized least squares (G.L.S.) estimators of y-sub-o. Section 4…

The correspondence between proximal phalanx morphology and locomotion: implications for inferring the locomotor behavior of fossil catarrhines.

PubMed

Rein, Thomas R

2011-11-01

Phalanges are considered to be highly informative in the reconstruction of extinct primate locomotor behavior since these skeletal elements directly interact with the substrate during locomotion. Variation in shaft curvature and relative phalangeal length has been linked to differences in the degree of suspension and overall arboreal locomotor activities. Building on previous work, this study investigated these two skeletal characters in a comparative context to analyze function, while taking evolutionary relationships into account. This study examined the correspondence between proportions of suspension and overall substrate usage observed in 17 extant taxa and included angle of curvature and relative phalangeal length. Predictive models based on these traits are reported. Published proportions of different locomotor behaviors were regressed against each phalangeal measurement and a size proxy. The relationship between each behavior and skeletal trait was investigated using ordinary least-squares, phylogenetic generalized least-squares (pGLS), and two pGLS transformation methods to determine the model of best-fit. Phalangeal curvature and relative length had significant positive relationships with both suspension and overall arboreal locomotion. Cross-validation analyses demonstrated that relative length and curvature provide accurate predictions of relative suspensory behavior and substrate usage in a range of extant species when used together in predictive models. These regression equations provide a refined method to assess the amount of suspensory and overall arboreal locomotion characterizing species in the catarrhine fossil record. Copyright © 2011 Wiley-Liss, Inc.

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…

Association between Global Life Satisfaction and Self-Rated Oral Health Conditions among Adolescents in Lithuania.

PubMed

Kavaliauskienė, Aistė; Šidlauskas, Antanas; Zaborskis, Apolinaras

2017-11-03

Background : This study aims to explore the extent to which the perceived oral conditions predict adolescent global life satisfaction (GLS); Methods : The sample in a cross-sectional survey consisted of 1510 Lithuanian adolescents (41.7% boys) aged 11-18. The survey was conducted by means of self-report questionnaires that were administrated in school classrooms ensuring confidentiality and anonymity of the participants. The schoolchildren rated their GLS and answered the questions about perceptions of their oral health. The relationship between GLS and oral health variables was estimated using unadjusted and adjusted binary logistic regression and nonparametric correlation analyses; Results : The research showed that the majority of adolescents rated their GLS highly; however, girls, older adolescents and adolescents from less affluent families were less likely to report high scores. GLS was significantly associated with subjective overall oral health assessment. The odds of reporting low GLS were 50% higher for adolescents with good oral health (OR = 1.51; p < 0.001; 95% CI = 1.18-1.93), and two and half time as higher for adolescents with perceived fair/poor oral health (OR = 2.78; p < 0.001; 95% CI = 1.72-4.50) compared to adolescents with subjectively excellent/very good oral health. Nonparametric correlations indicated lower GLS to be significantly associated with higher scores of Child Perceptions Questionnaire (.

Association between Global Life Satisfaction and Self-Rated Oral Health Conditions among Adolescents in Lithuania

PubMed Central

Kavaliauskienė, Aistė; Šidlauskas, Antanas; Zaborskis, Apolinaras

2017-01-01

Background: This study aims to explore the extent to which the perceived oral conditions predict adolescent global life satisfaction (GLS); Methods: The sample in a cross-sectional survey consisted of 1510 Lithuanian adolescents (41.7% boys) aged 11–18. The survey was conducted by means of self-report questionnaires that were administrated in school classrooms ensuring confidentiality and anonymity of the participants. The schoolchildren rated their GLS and answered the questions about perceptions of their oral health. The relationship between GLS and oral health variables was estimated using unadjusted and adjusted binary logistic regression and nonparametric correlation analyses; Results: The research showed that the majority of adolescents rated their GLS highly; however, girls, older adolescents and adolescents from less affluent families were less likely to report high scores. GLS was significantly associated with subjective overall oral health assessment. The odds of reporting low GLS were 50% higher for adolescents with good oral health (OR = 1.51; p < 0.001; 95% CI = 1.18–1.93), and two and half time as higher for adolescents with perceived fair/poor oral health (OR = 2.78; p < 0.001; 95% CI = 1.72–4.50) compared to adolescents with subjectively excellent/very good oral health. Nonparametric correlations indicated lower GLS to be significantly associated with higher scores of Child Perceptions Questionnaire (𝜌 = −0.17/−0.30; p < 0.01); Conclusions: Adolescents with oral health impairments more likely to report lower GLS, regardless of their gender and age. PMID:29099802

Techniques for estimating flood-peak discharges of rural, unregulated streams in Ohio

USGS Publications Warehouse

Koltun, G.F.

2003-01-01

Regional equations for estimating 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood-peak discharges at ungaged sites on rural, unregulated streams in Ohio were developed by means of ordinary and generalized least-squares (GLS) regression techniques. One-variable, simple equations and three-variable, full-model equations were developed on the basis of selected basin characteristics and flood-frequency estimates determined for 305 streamflow-gaging stations in Ohio and adjacent states. The average standard errors of prediction ranged from about 39 to 49 percent for the simple equations, and from about 34 to 41 percent for the full-model equations. Flood-frequency estimates determined by means of log-Pearson Type III analyses are reported along with weighted flood-frequency estimates, computed as a function of the log-Pearson Type III estimates and the regression estimates. Values of explanatory variables used in the regression models were determined from digital spatial data sets by means of a geographic information system (GIS), with the exception of drainage area, which was determined by digitizing the area within basin boundaries manually delineated on topographic maps. Use of GIS-based explanatory variables represents a major departure in methodology from that described in previous reports on estimating flood-frequency characteristics of Ohio streams. Examples are presented illustrating application of the regression equations to ungaged sites on ungaged and gaged streams. A method is provided to adjust regression estimates for ungaged sites by use of weighted and regression estimates for a gaged site on the same stream. A region-of-influence method, which employs a computer program to estimate flood-frequency characteristics for ungaged sites based on data from gaged sites with similar characteristics, was also tested and compared to the GLS full-model equations. For all recurrence intervals, the GLS full-model equations had superior prediction accuracy relative to the simple equations and therefore are recommended for use.

Glucosinolate profile and distribution among plant tissues and phenological stages of field-grown horseradish.

PubMed

Agneta, Rosa; Lelario, Filomena; De Maria, Susanna; Möllers, Christian; Bufo, Sabino Aurelio; Rivelli, Anna Rita

2014-10-01

Profile and distribution of glucosinolates (GLS) were detected in plant tissues of horseradish at different developmental stages: beginning of vegetative re-growth, flowering and silique formation. The GLS profile varied widely in the different tissues: we identified 17 GLS in roots and sprouts, one of which was not previously characterized in horseradish, i.e. the 2(S)-hydroxy-2-phenylethyl-GLS (glucobarbarin) and/or 2(R)-hydroxy-2-phenylethyl-GLS (epiglucobarbarin), 11 already found in the roots, including the putative 2-methylsulfonyl-oxo-ethyl-GLS, and 5 previously recognized only in the sprouts. Fifteen of those GLS were also identified in young and cauline leaves, 12 in the mature leaves and 13 in the inflorescences. No difference in GLS profile was observed in plant among the phenological stages. Differences in concentrations of GLS, quantified as desulfated, were found in plant. At the beginning of vegetative re-growth, sprouts while showing the same profile of the roots were much richer in GLS having the highest total GLS concentrations (117.5 and 7.7μmolg(-1) dry weight in sprouts and roots, respectively). During flowering and silique forming stages, the roots still maintained lower amount of total GLS (7.4μmolg(-1) of dry weight, on average) with respect to the epigeous tissues, in which mature and young leaves showed the highest total concentrations (70.5 and 73.8μmolg(-1) of dry weight on average, respectively). Regardless of the phenological stages, the aliphatic GLS were always predominant in all tissues (95%) followed by indolic (2.6%) and benzenic (2.4%) GLS. Sinigrin contributed more than 90% of the total GLS concentration. Aliphatic GLS concentrations were much higher in the epigeous tissues, particularly in the mature and young leaves, while benzenic and indolic GLS concentrations were higher in the roots. Through the phenological stages, GLS concentration increased in young and mature leaves and decreased in cauline leaves and inflorescences, while it remained constant over time in roots. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solidification of liposomes by freeze-drying: the importance of incorporating gelatin as interior support on enhanced physical stability.

PubMed

Guan, Peipei; Lu, Yi; Qi, Jianping; Niu, Mengmeng; Lian, Ruyue; Wu, Wei

2015-01-30

The main purpose of this study was to investigate the effect of gelatin as interior support on the physical stability of freeze-dried liposomes. Anticancer agent paclitaxel (PTX) was selected as a model drug. Freeze-dried liposomes containing interior gelatin support (GLs) were prepared by thin-film dispersion/freeze-drying method. Several properties of the GLs, including entrapment efficiency, particle size and gelation temperature, were extensively characterized. Encapsulation efficiency of conventional liposomes (CLs) and liposomes containing lyoprotectants as interior support dropped to lower than 20% after reconstitution, while GLs still maintained an entrapment efficiency of over 84%. Scanning electron microscopy revealed well preserved liposomal structure of GLs after reconstitution. Meanwhile, the particle size and entrapment efficiency of GLs were also well preserved after reconstitution. In contrary, deformation of CLs and recrystallization of PTX were observed, as well as significant changes in particle size and entrapment efficiency. Taken together, interior gelatin support obviously enhanced the physical stability of liposomes against the lyophilization stress. Copyright © 2014 Elsevier B.V. All rights reserved.

Graduate Liberal Studies.

ERIC Educational Resources Information Center

Brown, Peggy, Ed.

1982-01-01

An article on graduate liberal studies (GLS) and descriptions of GLS programs are presented. In "The Concept of Graduate Liberal Studies," Allie M. Frazier considers GLS curricular offerings, characteristics of students pursuing these studies, and the future of GLS. GLS degree programs allow adults to pursue a liberal education, which is…

Optical, Thermal, and Mechanical Characterization of Ga2 Se3 -Added GLS Glass.

PubMed

Ravagli, Andrea; Craig, Christopher; Alzaidy, Ghada A; Bastock, Paul; Hewak, Daniel W

2017-07-01

Gallium lanthanum sulfide glass (GLS) has been widely studied in the last 40 years for middle-infrared applications. In this work, the results of the substitution of selenium for sulphur in GLS glass are described. The samples are prepared via melt-quench method in an argon-purged atmosphere. A wide range of compositional substitutions are studied to define the glass-forming region of the modified material. The complete substitution of Ga 2 S 3 by Ga 2 Se 3 is achieved by involving new higher quenching rate techniques compared to those containing only sulfides. The samples exhibiting glassy characteristics are further characterized. In particular, the optical and thermal properties of the sample are investigated in order to understand the role of selenium in the formation of the glass. The addition of selenium to GLS glass generally results in a lower glass transition temperature and an extended transmission window. Particularly, the IR edge is found to be extended from about 9 µm for GLS glass to about 15 µm for Se-added GLS glass defined by the 50% transmission point. Furthermore, the addition of selenium does not affect the UV edge dramatically. The role of selenium is hypothesized in the glass formation to explain these changes. © 2017 University of Southampton. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

GLCF: Global Land Survey(GLS)

Science.gov Websites

Services Contact Site Map Go Global Land Survey(GLS) Data Access ESDI Download via Search and Preview Tool gls The Global Land Survey (GLS) collection of Landsat imagery is designed to meet a need from Availability: GLS 1975, 1990, 2000, and 2005 are available to the public for free at the US Geological Survey

Identification of alleles conferring resistance to gray leaf spot in maize derived from its wild progenitor species teosinte (Zea mays ssp. parviglumis)

USDA-ARS?s Scientific Manuscript database

Gray Leaf Spot [(GLS), causal agent Cercospora zeae-maydis and Cercospora zeina] is an important maize disease in the United States. Current control methods for GLS include using resistant cultivars, crop rotation, chemical applications, and conventional tillage to reduce inoculum levels. Teosinte ...

p63 regulates glutaminase 2 expression

PubMed Central

Giacobbe, Arianna; Bongiorno-Borbone, Lucilla; Bernassola, Francesca; Terrinoni, Alessandro; Markert, Elke Katrin; Levine, Arnold J.; Feng, Zhaohui; Agostini, Massimilano; Zolla, Lello; Agrò, Alessandro Finazzi; Notterman, Daniel A.; Melino, Gerry; Peschiaroli, Angelo

2013-01-01

The transcription factor p63 is critical for many biological processes, including development and maintenance of epidermal tissues and tumorigenesis. Here, we report that the TAp63 isoforms regulate cell metabolism through the induction of the mitochondrial glutaminase 2 (GLS2) gene both in primary cells and tumor cell lines. By ChIP analysis and luciferase assay, we confirmed that TAp63 binds directly to the p53/p63 consensus DNA binding sequence within the GLS2 promoter region. Given the critical role of p63 in epidermal differentiation, we have investigated the regulation of GLS2 expression during this process. GLS2 and TAp63 expression increases during the in vitro differentiation of primary human keratinocytes, and depletion of GLS2 inhibits skin differentiation both at molecular and cellular levels. We found that GLS2 and TAp63 expression are concomitantly induced in cancer cells exposed to oxidative stresses. siRNA-mediated depletion of GLS2 sensitizes cells to ROS-induced apoptosis, suggesting that the TAp63/GLS2 axis can be functionally important as a cellular antioxidant pathway in the absence of p53. Accordingly, we found that GLS2 is upregulated in colon adenocarcinoma. Altogether, our findings demonstrate that GLS2 is a bona fide TAp63 target gene, and that the TAp63-dependent regulation of GLS2 is important for both physiological and pathological processes. PMID:23574722

The Role of Multiphysics Simulation in Multidisciplinary Analysis

NASA Technical Reports Server (NTRS)

Rifai, Steven M.; Ferencz, Robert M.; Wang, Wen-Ping; Spyropoulos, Evangelos T.; Lawrence, Charles; Melis, Matthew E.

1998-01-01

This article describes the applications of the Spectrum(Tm) Solver in Multidisciplinary Analysis (MDA). Spectrum, a multiphysics simulation software based on the finite element method, addresses compressible and incompressible fluid flow, structural, and thermal modeling as well as the interaction between these disciplines. Multiphysics simulation is based on a single computational framework for the modeling of multiple interacting physical phenomena. Interaction constraints are enforced in a fully-coupled manner using the augmented-Lagrangian method. Within the multiphysics framework, the finite element treatment of fluids is based on Galerkin-Least-Squares (GLS) method with discontinuity capturing operators. The arbitrary-Lagrangian-Eulerian method is utilized to account for deformable fluid domains. The finite element treatment of solids and structures is based on the Hu-Washizu variational principle. The multiphysics architecture lends itself naturally to high-performance parallel computing. Aeroelastic, propulsion, thermal management and manufacturing applications are presented.

Impact of image quality on reliability of the measurements of left ventricular systolic function and global longitudinal strain in 2D echocardiography

PubMed Central

Nagata, Yasufumi; Kado, Yuichiro; Onoue, Takeshi; Otani, Kyoko; Nakazono, Akemi; Otsuji, Yutaka; Takeuchi, Masaaki

2018-01-01

Background Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) play important roles in diagnosis and management of cardiac diseases. However, the issue of the accuracy and reliability of LVEF and GLS remains to be solved. Image quality is one of the most important factors affecting measurement variability. The aim of this study was to investigate whether improved image quality could reduce observer variability. Methods Two sets of three apical images were acquired using relatively old- and new-generation ultrasound imaging systems (Vivid 7 and Vivid E95) in 308 subjects. Image quality was assessed by endocardial border delineation index (EBDI) using a 3-point scoring system. Three observers measured the LVEF and GLS, and these values and inter-observer variability were investigated. Results Image quality was significantly better with Vivid E95 (EBDI: 26.8 ± 5.9) than that with Vivid 7 (22.8 ± 6.3, P < 0.0001). Regarding the inter-observer variability of LVEF, the r-value, bias, 95% limit of agreement and intra-class correlation coefficient for Vivid 7 were comparable to those for Vivid E95. The % variabilities were significantly lower for Vivid E95 (5.3–6.5%) than those for Vivid 7 (6.5–7.5%). Regarding GLS, all observer variability parameters were better for Vivid E95 than for Vivid 7. Improvements in image quality yielded benefits to both LVEF and GLS measurement reliability. Multivariate analysis showed that image quality was indeed an important factor of observer variability in the measurement of LVEF and GLS. Conclusions The new-generation ultrasound imaging system offers improved image quality and reduces inter-observer variability in the measurement of LVEF and GLS. PMID:29432198

Influence of internal biogas production on hydrodynamic behavior of anaerobic fluidized-bed reactors.

PubMed

Wu, Chun-Sheng; Huang, Ju-Sheng; Chou, Hsin-Hsien

2006-01-01

Predictive models for describing the hydrodynamic behavior (bed-expansion and bed-pressure gradient) of a three-phase anaerobic fluidized bed reactor (AFBR) was developed according to wake theory together with more realistic dynamic bed-expansion experiments (with and without internal biogas production). A reliable correlation equation for the parameter k (mean volume ratio of wakes to bubbles) was also established, which is of help in estimating liquid hold up of fluidized beds. The experimental expansion ratio of three-phase fluidized beds (E(GLS)) was approximately 18% higher than that of two-phase fluidized beds (E(LS)); whereas the experimental bed-pressure gradient of the former [(-DeltaP/H)(GLS)] was approximately 9.3% lower than that of the latter [(-DeltaP/H)(LS)]. Both the experimental and modeling results indicated that a higher superficial gas velocity (u(g)) gave a higher E(GLS) and a higher E(GLS) to E(LS) ratio as well as a lower (-DeltaP/H)(GLS) and a lower (-DeltaP/H)(GLS) to (-DeltaP/H)(LS) ratio. As for the operation stability of the AFBR, the sensitivity of u(g) to expansion height (H(GLS)) and (-DeltaP/H)(GLS) is between the sensitivity of superficial liquid velocity and biofilm thickness. The model predictions of E(GLS), (-DeltaP)(GLS), and (-DeltaP/H)(GLS) agreed well the experimental measurements. Accordingly, the predictive models accounting for internal biogas production described fairly well the hydrodynamic behavior of the AFBR.

Pollination Mode and Mating System Explain Patterns in Genetic Differentiation in Neotropical Plants

PubMed Central

Ballesteros-Mejia, Liliana; Lima, Natácia E.; Lima-Ribeiro, Matheus S.

2016-01-01

We studied genetic diversity and differentiation patterns in Neotropical plants to address effects of life history traits (LHT) and ecological attributes based on an exhaustive literature survey. We used generalized linear mixed models (GLMMs) to test the effects as fixed and random factors of growth form, pollination and dispersal modes, mating and breeding systems, geographical range and habitat on patterns of genetic diversity (HS, HeS, π and h), inbreeding coefficient (FIS), allelic richness (AR) and differentiation among populations (FST) for both nuclear and chloroplast genomes. In addition, we used phylogenetic generalized least squares (pGLS) to account for phylogenetic independence on predictor variables and verify the robustness of the results from significant GLMMs. In general, GLMM revealed more significant relationships among LHTs and genetic patterns than pGLS. After accounting for phylogenetic independence (i.e., using pGLS), FST for nuclear microsatellites was significantly related to pollination mode, mating system and habitat. Plants specifically with outcrossing mating system had lower FST. Moreover, AR was significantly related to pollination mode and geographical range and HeS for nuclear dominant markers was significantly related to habitat. Our findings showed that different results might be retrieved when phylogenetic non-independence is taken into account and that LHTs and ecological attributes affect substantially the genetic pattern in Neotropical plants, hence may drive key evolutionary processes in plants. PMID:27472384

Multiple ABC glucoside transporters mediate sugar-stimulated growth in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.

PubMed

Nieves-Morión, Mercedes; Flores, Enrique

2018-02-01

Cyanobacteria are generally capable of photoautotrophic growth and are widely distributed on Earth. The model filamentous, heterocyst-forming strain Anabaena sp. PCC 7120 has long been considered as a strict photoautotroph but is now known to be able to assimilate fructose. We have previously described two components of ABC glucoside uptake transporters from Anabaena that are involved in uptake of the sucrose analog esculin: GlsC [a nucleotide-binding domain subunit (NBD)] and GlsP [a transmembrane component (TMD)]. Here, we created Anabaena mutants of genes encoding three further ABC transporter components needed for esculin uptake: GlsD (NBD), GlsQ (TMD) and GlsR (periplasmic substrate-binding protein). Phototrophic growth of Anabaena was significantly stimulated by sucrose, fructose and glucose. Whereas the glsC and glsD mutants were drastically hampered in sucrose-stimulated growth, the different gls mutants were generally impaired in sugar-dependent growth. Our results suggest the participation of Gls and other ABC transporters encoded in the Anabaena genome in sugar-stimulated growth. Additionally, Gls transporter components influence the function of septal junctions in the Anabaena filament. We suggest that mixotrophic growth is important in cyanobacterial physiology and may be relevant for the wide success of these organisms in diverse environments. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Assessment of the NASA-USGS Global Land Survey (GLS) Datasets

USGS Publications Warehouse

Gutman, Garik; Huang, Chengquan; Chander, Gyanesh; Noojipady, Praveen; Masek, Jeffery G.

2013-01-01

The Global Land Survey (GLS) datasets are a collection of orthorectified, cloud-minimized Landsat-type satellite images, providing near complete coverage of the global land area decadally since the early 1970s. The global mosaics are centered on 1975, 1990, 2000, 2005, and 2010, and consist of data acquired from four sensors: Enhanced Thematic Mapper Plus, Thematic Mapper, Multispectral Scanner, and Advanced Land Imager. The GLS datasets have been widely used in land-cover and land-use change studies at local, regional, and global scales. This study evaluates the GLS datasets with respect to their spatial coverage, temporal consistency, geodetic accuracy, radiometric calibration consistency, image completeness, extent of cloud contamination, and residual gaps. In general, the three latest GLS datasets are of a better quality than the GLS-1990 and GLS-1975 datasets, with most of the imagery (85%) having cloud cover of less than 10%, the acquisition years clustered much more tightly around their target years, better co-registration relative to GLS-2000, and better radiometric absolute calibration. Probably, the most significant impediment to scientific use of the datasets is the variability of image phenology (i.e., acquisition day of year). This paper provides end-users with an assessment of the quality of the GLS datasets for specific applications, and where possible, suggestions for mitigating their deficiencies.

Aging Reduces an ERRalpha-Directed Mitochondrial Glutaminase Expression Suppressing Glutamine Anaplerosis and Osteogenic Differentiation of Mesenchymal Stem Cells.

PubMed

Huang, Tongling; Liu, Renzhong; Fu, Xuekun; Yao, Dongsheng; Yang, Meng; Liu, Qingli; Lu, William W; Wu, Chuanyue; Guan, Min

2017-02-01

Aging deteriorates osteogenic capacity of mesenchymal stem/stromal cells (MSCs), contributing to imbalanced bone remodeling and osteoporosis. Glutaminase (Gls) catabolizes glutamine into glutamate at the first step of mitochondrial glutamine (Gln)-dependent anaplerosis which is essential for MSCs upon osteogenic differentiation. Estrogen-related receptor α (ERRα) regulates genes required for mitochondrial function. Here, we found that ERRα and Gls are upregulated by osteogenic induction in human MSCs (hMSCs). In contrast, osteogenic differentiation capacity and glutamine consumption of MSCs, as well as ERRα, Gls and osteogenic marker genes are significantly reduced with age. We demonstrated that ERRα binds to response elements on Gls promoter and affects glutamine anaplerosis through transcriptional induction of Gls. Conversely, mTOR inhibitor rapamycin, ERRα inverse agonist compound 29 or Gls inhibitor BPTES leads to reduced Gln anaplerosis and deteriorated osteogenic differentiation of hMSCs. Importantly, overexpression of ERRα or Gls restored impairment by these inhibitors. Finally, we proved that compensated ERRα or Gls expression indeed potentiated Gln anaplerosis and osteogenic capability of elderly mice MSCs in vitro. Together, we establish that Gls is a novel ERRα target gene and ERRα/Gls signaling pathway plays an important role in osteogenic differentiation of MSCs, providing new sights into novel regenerative therapeutics development. Our findings suggest that restoring age-related mitochondrial Gln-dependent anaplerosis may be beneficial for degenerative bone disorders such as osteoporosis. Stem Cells 2017;35:411-424. © 2016 AlphaMed Press.

The prognostic value of standardized reference values for speckle-tracking global longitudinal strain in hypertrophic cardiomyopathy.

PubMed

Hartlage, Gregory R; Kim, Jonathan H; Strickland, Patrick T; Cheng, Alan C; Ghasemzadeh, Nima; Pernetz, Maria A; Clements, Stephen D; Williams, B Robinson

2015-03-01

Speckle-tracking left ventricular global longitudinal strain (GLS) assessment may provide substantial prognostic information for hypertrophic cardiomyopathy (HCM) patients. Reference values for GLS have been recently published. We aimed to evaluate the prognostic value of standardized reference values for GLS in HCM patients. An analysis of HCM clinic patients who underwent GLS was performed. GLS was defined as normal (more negative or equal to -16%) and abnormal (less negative than -16%) based on recently published reference values. Patients were followed for a composite of events including heart failure hospitalization, sustained ventricular arrhythmia, and all-cause death. The power of GLS to predict outcomes was assessed relative to traditional clinical and echocardiographic variables present in HCM. 79 HCM patients were followed for a median of 22 months (interquartile range 9-30 months) after imaging. During follow-up, 15 patients (19%) met the primary outcome. Abnormal GLS was the only echocardiographic variable independently predictive of the primary outcome [multivariate Hazard ratio 5.05 (95% confidence interval 1.09-23.4, p = 0.038)]. When combined with traditional clinical variables, abnormal GLS remained independently predictive of the primary outcome [multivariate Hazard ratio 5.31 (95 % confidence interval 1.18-24, p = 0.030)]. In a model including the strongest clinical and echocardiographic predictors of the primary outcome, abnormal GLS demonstrated significant incremental benefit for risk stratification [net reclassification improvement 0.75 (95 % confidence interval 0.21-1.23, p < 0.0001)]. Abnormal GLS is an independent predictor of adverse outcomes in HCM patients. Standardized use of GLS may provide significant incremental value over traditional variables for risk stratification.

Reinforcing good practice: Implementation of guidelines at hospital G. Pini.

PubMed

Nobile, M; Bronzin, S; Navone, P; Colombo, M; Calori, G M; Auxilia, F

2014-12-01

Surgical site infections (SSIs) in orthopaedic surgery are a demanding complication for the patient and in terms of economics. Many guidelines (GLs) are available on antibiotic prophylaxis as an effective preventive measure; however, these GLs are often ignored in practice. A surveillance study of SSIs in arthroplasty, promoted by the Italian Study Group of Hospital Hygiene of the Italian Society of Public Health (SitI), showed a high percentage of non-adherence to GLs on antibiotic prophylaxis. The purpose of this study was to review the existing GLs, share them within the hospital and then monitor their implementation. Information and training are considered to be great tools for implementation and sharing of GLs, which leads to significant improvements in clinical practice. A multidisciplinary team comprising infectious disease specialists, orthopaedic surgeons, nurse epidemiologists and public health specialists was established at the G. Pini Hospital in Milan to revise GLs, and to organise educational events for their implementation, sharing and dissemination. A checklist was devised for monitoring purposes. GLs were presented to orthopaedic surgeons and nurse coordinators during two educational events. Meetings were organised in each unit to present the results of the surveillance of SSIs in arthroplasty and to discuss the reasons why the prophylaxis regimens adopted were not consistent with GLs. It was emphasised that the most important issue, on which there is consensus in the scientific literature, was related to the duration of prophylaxis beyond 24h. The review process for GLs was presented and pocket-sized GLs were given to surgeons. The importance of documenting on medical record any deviations from the GLs was emphasised. Any changes in behaviour in clinical practice must be monitored and evaluated regularly. The monitoring of GLs in terms of correct choice of drug, timing of administration and duration of prophylaxis is made using a special checklist on a representative sample of medical records. Copyright © 2014 Elsevier Ltd. All rights reserved.

Expectations among the elderly about nursing home entry.

PubMed

Lindrooth, R C; Hoerger, T J; Norton, E C

2000-12-01

To assess whether the covariates that explain expectations of nursing home entry are consistent with the characteristics of those who enter nursing homes. Waves 1 and 2 of the Assets and Health Dynamics Among the Oldest Old (AHEAD) survey. We model expectations about nursing home entry as a function of expectations about leaving a bequest, living at least ten years, health condition, and other observed characteristics. We use an instrumental variables and generalized least squares (IV-GLS) method based on Hausman and Taylor (1981) to obtain more efficient estimates than fixed effects, without the restrictive assumptions of random effects. Expectations about nursing home entry are reasonably close to the actual probability of nursing home entry. Most of the variables that affect actual entry also have significant effects on expectations about entry. Medicaid subsidies for nursing home care may have little effect on expectations about nursing home entry; individuals in the lowest asset quartile, who are most likely to receive these subsidies, report probabilities not significantly different from those in other quartiles. Application of the IV-GLS approach is supported by a series of specification tests. We find that expectations about future nursing home entry are consistent with the characteristics of actual entrants. Underestimation of risk of nursing home entry as a reason for low levels of long-term care insurance is not supported by this analysis.

The impact of multiple endpoint dependency on Q and I(2) in meta-analysis.

PubMed

Thompson, Christopher Glen; Becker, Betsy Jane

2014-09-01

A common assumption in meta-analysis is that effect sizes are independent. When correlated effect sizes are analyzed using traditional univariate techniques, this assumption is violated. This research assesses the impact of dependence arising from treatment-control studies with multiple endpoints on homogeneity measures Q and I(2) in scenarios using the unbiased standardized-mean-difference effect size. Univariate and multivariate meta-analysis methods are examined. Conditions included different overall outcome effects, study sample sizes, numbers of studies, between-outcomes correlations, dependency structures, and ways of computing the correlation. The univariate approach used typical fixed-effects analyses whereas the multivariate approach used generalized least-squares (GLS) estimates of a fixed-effects model, weighted by the inverse variance-covariance matrix. Increased dependence among effect sizes led to increased Type I error rates from univariate models. When effect sizes were strongly dependent, error rates were drastically higher than nominal levels regardless of study sample size and number of studies. In contrast, using GLS estimation to account for multiple-endpoint dependency maintained error rates within nominal levels. Conversely, mean I(2) values were not greatly affected by increased amounts of dependency. Last, we point out that the between-outcomes correlation should be estimated as a pooled within-groups correlation rather than using a full-sample estimator that does not consider treatment/control group membership. Copyright © 2014 John Wiley & Sons, Ltd.

Expectations among the elderly about nursing home entry.

PubMed Central

Lindrooth, R C; Hoerger, T J; Norton, E C

2000-01-01

OBJECTIVE: To assess whether the covariates that explain expectations of nursing home entry are consistent with the characteristics of those who enter nursing homes. DATA SOURCES: Waves 1 and 2 of the Assets and Health Dynamics Among the Oldest Old (AHEAD) survey. STUDY DESIGN: We model expectations about nursing home entry as a function of expectations about leaving a bequest, living at least ten years, health condition, and other observed characteristics. We use an instrumental variables and generalized least squares (IV-GLS) method based on Hausman and Taylor (1981) to obtain more efficient estimates than fixed effects, without the restrictive assumptions of random effects. PRINCIPAL FINDINGS: Expectations about nursing home entry are reasonably close to the actual probability of nursing home entry. Most of the variables that affect actual entry also have significant effects on expectations about entry. Medicaid subsidies for nursing home care may have little effect on expectations about nursing home entry; individuals in the lowest asset quartile, who are most likely to receive these subsidies, report probabilities not significantly different from those in other quartiles. Application of the IV-GLS approach is supported by a series of specification tests. CONCLUSIONS: We find that expectations about future nursing home entry are consistent with the characteristics of actual entrants. Underestimation of risk of nursing home entry as a reason for low levels of long-term care insurance is not supported by this analysis. PMID:11130816

August median streamflow on ungaged streams in Eastern Coastal Maine

USGS Publications Warehouse

Lombard, Pamela J.

2004-01-01

Methods for estimating August median streamflow were developed for ungaged, unregulated streams in eastern coastal Maine. The methods apply to streams with drainage areas ranging in size from 0.04 to 73.2 square miles and fraction of basin underlain by a sand and gravel aquifer ranging from 0 to 71 percent. The equations were developed with data from three long-term (greater than or equal to 10 years of record) continuous-record streamflow-gaging stations, 23 partial-record streamflow- gaging stations, and 5 short-term (less than 10 years of record) continuous-record streamflow-gaging stations. A mathematical technique for estimating a standard low-flow statistic, August median streamflow, at partial-record streamflow-gaging stations and short-term continuous-record streamflow-gaging stations was applied by relating base-flow measurements at these stations to concurrent daily streamflows at nearby long-term continuous-record streamflow-gaging stations (index stations). Generalized least-squares regression analysis (GLS) was used to relate estimates of August median streamflow at streamflow-gaging stations to basin characteristics at these same stations to develop equations that can be applied to estimate August median streamflow on ungaged streams. GLS accounts for different periods of record at the gaging stations and the cross correlation of concurrent streamflows among gaging stations. Thirty-one stations were used for the final regression equations. Two basin characteristics?drainage area and fraction of basin underlain by a sand and gravel aquifer?are used in the calculated regression equation to estimate August median streamflow for ungaged streams. The equation has an average standard error of prediction from -27 to 38 percent. A one-variable equation uses only drainage area to estimate August median streamflow when less accuracy is acceptable. This equation has an average standard error of prediction from -30 to 43 percent. Model error is larger than sampling error for both equations, indicating that additional or improved estimates of basin characteristics could be important to improved estimates of low-flow statistics. Weighted estimates of August median streamflow at partial- record or continuous-record gaging stations range from 0.003 to 31.0 cubic feet per second or from 0.1 to 0.6 cubic feet per second per square mile. Estimates of August median streamflow on ungaged streams in eastern coastal Maine, within the range of acceptable explanatory variables, range from 0.003 to 45 cubic feet per second or 0.1 to 0.6 cubic feet per second per square mile. Estimates of August median streamflow per square mile of drainage area generally increase as drainage area and fraction of basin underlain by a sand and gravel aquifer increase.

The Janus kinase inhibitor tofacitinib inhibits TNF-α-induced gliostatin expression in rheumatoid fibroblast-like synoviocytes.

PubMed

Kawaguchi, Yohei; Waguri-Nagaya, Yuko; Tatematsu, Naoe; Oguri, Yusuke; Kobayashi, Masaaki; Nozaki, Masahiro; Asai, Kiyofumi; Aoyama, Mineyoshi; Otsuka, Takanobu

2018-01-15

Gliostatin (GLS) is known to have angiogenic and arthritogenic activity, and GLS expression levels in serum from patients with rheumatoid arthritis (RA) are significantly correlated with the disease activity. Tofacitinib is a novel oral Janus kinase (JAK) inhibitor and is effective in treating RA. However, the mechanism of action of tofacitinib in fibroblast-like synoviocytes (FLSs) has not been elucidated. The purpose of this study was to investigate the modulatory effects of tofacitinib on serum GLS levels in patients with RA and GLS production in FLSs derived from patients with RA. Six patients with RA who had failed therapy with at least one TNF inhibitor and were receiving tofacitinib therapy were included in the study. Serum samples were collected to measure CRP, MMP-3 and GLS expression. FLSs derived from patients with RA were cultured and stimulated by TNFα with or without tofacitinib. GLS expression levels were determined using reverse transcription-polymerase chain reaction (RT-PCR), EIA and immunocytochemistry, and signal transducer and activator of transcription (STAT) protein phosphorylation levels were determined by western blotting. Treatment with tofacitinib decreased serum GLS levels in all patients. GLS mRNA and protein expression levels were significantly increased by treatment with TNF-α alone, and these increases were suppressed by treatment with tofacitinib, which also inhibited TNF-α-induced STAT1 phosphorylation. JAK/STAT activation plays a pivotal role in TNF-α-mediated GLS up-regulation in RA. Suppression of GLS expression in FLSs has been suggested to be one of the mechanisms through which tofacitinib exerts its anti-inflammatory effects.

Impact of the Garrett Lee Smith youth suicide prevention program on suicide mortality.

PubMed

Walrath, Christine; Garraza, Lucas Godoy; Reid, Hailey; Goldston, David B; McKeon, Richard

2015-05-01

We examined whether a reduction in youth suicide mortality occurred between 2007 and 2010 that could reasonably be attributed to Garrett Lee Smith (GLS) program efforts. We compared youth mortality rates across time between counties that implemented GLS-funded gatekeeper training sessions (the most frequently implemented suicide prevention strategy among grantees) and a set of matched counties in which no GLS-funded training occurred. A rich set of background characteristics, including preintervention mortality rates, was accounted for with a combination of propensity score-based techniques. We also analyzed closely related outcomes that we did not expect to be affected by GLS as control outcomes. Counties implementing GLS training had significantly lower suicide rates among the population aged 10 to 24 years the year after GLS training than similar counties that did not implement GLS training (1.33 fewer deaths per 100 000; P = .02). Simultaneously, we found no significant difference in terms of adult suicide mortality rates or nonsuicide youth mortality the year after the implementation. These results support the existence of an important reduction in youth suicide rates resulting from the implementation of GLS suicide prevention programming.

GLS-Finder: A Platform for Fast Profiling of Glucosinolates in Brassica Vegetables.

PubMed

Sun, Jianghao; Zhang, Mengliang; Chen, Pei

2016-06-01

Mass spectrometry combined with related tandem techniques has become the most popular method for plant secondary metabolite characterization. We introduce a new strategy based on in-database searching, mass fragmentation behavior study, formula predicting for fast profiling of glucosinolates, a class of important compounds in brassica vegetables. A MATLAB script-based expert system computer program, "GLS-Finder", was developed. It is capable of qualitative and semi-quantitative analyses of glucosinolates in samples using data generated by ultrahigh-performance liquid chromatography-high-resolution accurate mass with multi-stage mass fragmentation (UHPLC-HRAM/MS(n)). A suite of bioinformatic tools was integrated into the "GLS-Finder" to perform raw data deconvolution, peak alignment, glucosinolate putative assignments, semi-quantitation, and unsupervised principal component analysis (PCA). GLS-Finder was successfully applied to identify intact glucosinolates in 49 commonly consumed Brassica vegetable samples in the United States. It is believed that this work introduces a new way of fast data processing and interpretation for qualitative and quantitative analyses of glucosinolates, where great efficacy was improved in comparison to identification manually.

August Median Streamflow on Ungaged Streams in Eastern Aroostook County, Maine

USGS Publications Warehouse

Lombard, Pamela J.; Tasker, Gary D.; Nielsen, Martha G.

2003-01-01

Methods for estimating August median streamflow were developed for ungaged, unregulated streams in the eastern part of Aroostook County, Maine, with drainage areas from 0.38 to 43 square miles and mean basin elevations from 437 to 1,024 feet. Few long-term, continuous-record streamflow-gaging stations with small drainage areas were available from which to develop the equations; therefore, 24 partial-record gaging stations were established in this investigation. A mathematical technique for estimating a standard low-flow statistic, August median streamflow, at partial-record stations was applied by relating base-flow measurements at these stations to concurrent daily flows at nearby long-term, continuous-record streamflow- gaging stations (index stations). Generalized least-squares regression analysis (GLS) was used to relate estimates of August median streamflow at gaging stations to basin characteristics at these same stations to develop equations that can be applied to estimate August median streamflow on ungaged streams. GLS accounts for varying periods of record at the gaging stations and the cross correlation of concurrent streamflows among gaging stations. Twenty-three partial-record stations and one continuous-record station were used for the final regression equations. The basin characteristics of drainage area and mean basin elevation are used in the calculated regression equation for ungaged streams to estimate August median flow. The equation has an average standard error of prediction from -38 to 62 percent. A one-variable equation uses only drainage area to estimate August median streamflow when less accuracy is acceptable. This equation has an average standard error of prediction from -40 to 67 percent. Model error is larger than sampling error for both equations, indicating that additional basin characteristics could be important to improved estimates of low-flow statistics. Weighted estimates of August median streamflow, which can be used when making estimates at partial-record or continuous-record gaging stations, range from 0.03 to 11.7 cubic feet per second or from 0.1 to 0.4 cubic feet per second per square mile. Estimates of August median streamflow on ungaged streams in the eastern part of Aroostook County, within the range of acceptable explanatory variables, range from 0.03 to 30 cubic feet per second or 0.1 to 0.7 cubic feet per second per square mile. Estimates of August median streamflow per square mile of drainage area generally increase as mean elevation and drainage area increase.

National clinical practice guidelines for allergen immunotherapy: An international assessment applying AGREE-II.

PubMed

Larenas-Linnemann, D E S; Antolín-Amérigo, D; Parisi, C; Nakonechna, A; Luna-Pech, J A; Wedi, B; Davila, I; Gómez, M; Levin, M; Ortega Martell, J A; Klimek, L; Rosario, N; Muraro, A M; Agache, I; Bousquet, J; Sheikh, A; Pfaar, O

2018-03-01

Since 1988, numerous allergen immunotherapy guidelines (AIT-GLs) have been developed by national and international organizations to guide physicians in AIT. Even so, AIT is still severely underused. To evaluate AIT-GLs with AGREE-II, developed in 2010 by McMaster University methodologists to comprehensively evaluate GL quality. Allergist, from different continents, knowledgeable in AIT and AGREE-II trained were selected into the project team. The project received methodologists' guidance. AIT-GLs in any language were sought from 1980 to 2016; AIT-GLs were AGREE II-evaluated by at least 2 team members, independently; discrepancies were resolved in a second round, by team discussion or methodologists' consulting. We found 31 AIT-GLs (15 post-2010), ranging from local consensus reports to international position papers (EAACI, AAAAI-ACAAI, WAO). Pre-2010 GLs scored 1.6-4.6 (23%-67%) and post-2010 GLs scored 2.1-6 (30%-86%), on a 7-point Likert scale. The highest scores went to: German-Austrian-Swiss (6.0), Mexican (5.1), and the AAAAI/ACAAI AIT-GL (4.7). These were also the only 3 GLs that received "yes" of both evaluators to the item: "I would recommend this GL for use." The domains of "Stakeholder involvement" and "Rigor of Development" only scored 3/7, and "Applicability" scored the lowest. Strikingly, newer GLs only scored clearly better in "Editorial independence" and "Global evaluation." In AIT-GLs, there is still a lot of room for improvement, especially in domains crucial for the dissemination. For some GLs, the "Scientific rigor" domain flawed. When resources are limited, transculturizing a high-quality GL might be preferable over developing a GL from zero. Our study and AGREE-II could help to select the best candidate. We here evaluate allergen immunotherapy guideline (AIT-GL) quality. Only high-quality AIT-GLs should be consulted for AIT management decisions. In low-resource settings, transculturization of these is preferred over developing low-quality guidelines. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Global Longitudinal Strain to Predict Mortality in Patients With Acute Heart Failure.

PubMed

Park, Jin Joo; Park, Jun-Bean; Park, Jae-Hyeong; Cho, Goo-Yeong

2018-05-08

Heart failure (HF) is currently classified according to left ventricular ejection fraction (LVEF); however, the prognostic value of LVEF is controversial. Myocardial strain is a prognostic factor independently of LVEF. The authors sought to evaluate the prognostic value of global longitudinal strain (GLS) in patients with HF. GLS was measured in 4,172 consecutive patients with acute HF. Patients were categorized as either HF with reduced (LVEF <40%), midrange (LVEF 40% to 49%), or preserved ejection fraction (LVEF ≥50%) and were also classified as having mildly (GLS >12.6%), moderately (8.1% < GLS <12.5%), or severely (GLS ≤8.0%) reduced strain. The primary endpoint was 5-year all-cause mortality. Mean GLS was 10.8%, and mean LVEF was 40%. Overall, 1,740 (40.4%) patients had died at 5 years. Patients with reduced ejection fraction had slightly higher mortality than those with midrange or preserved ejection fraction (41%, 38%, and 39%, respectively; log-rank p = 0.031), whereas patients with reduced strain had significantly higher mortality (severely reduced GLS, 49%; moderately reduced GLS, 38%; mildly reduced GLS, 34%; log-rank p < 0.001). In multivariable analysis, each 1% increase in GLS was associated with a 5% decreased risk for mortality (p < 0.001). Patients with moderate (hazard ratio: 1.31; 95% confidence interval: 1.13 to 1.53) and severe GLS reductions (hazard ratio: 1.61; 95% confidence interval: 1.36 to 1.91) had higher mortality, but LVEF was not associated with mortality. In patients with acute HF, GLS has greater prognostic value than LVEF. Therefore, the authors suggest that GLS should be considered as the standard measurement in all patients with HF. This new concept needs validation in further studies. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

On the use of Bayesian Monte-Carlo in evaluation of nuclear data

NASA Astrophysics Data System (ADS)

De Saint Jean, Cyrille; Archier, Pascal; Privas, Edwin; Noguere, Gilles

2017-09-01

As model parameters, necessary ingredients of theoretical models, are not always predicted by theory, a formal mathematical framework associated to the evaluation work is needed to obtain the best set of parameters (resonance parameters, optical models, fission barrier, average width, multigroup cross sections) with Bayesian statistical inference by comparing theory to experiment. The formal rule related to this methodology is to estimate the posterior density probability function of a set of parameters by solving an equation of the following type: pdf(posterior) ˜ pdf(prior) × a likelihood function. A fitting procedure can be seen as an estimation of the posterior density probability of a set of parameters (referred as x→?) knowing a prior information on these parameters and a likelihood which gives the probability density function of observing a data set knowing x→?. To solve this problem, two major paths could be taken: add approximations and hypothesis and obtain an equation to be solved numerically (minimum of a cost function or Generalized least Square method, referred as GLS) or use Monte-Carlo sampling of all prior distributions and estimate the final posterior distribution. Monte Carlo methods are natural solution for Bayesian inference problems. They avoid approximations (existing in traditional adjustment procedure based on chi-square minimization) and propose alternative in the choice of probability density distribution for priors and likelihoods. This paper will propose the use of what we are calling Bayesian Monte Carlo (referred as BMC in the rest of the manuscript) in the whole energy range from thermal, resonance and continuum range for all nuclear reaction models at these energies. Algorithms will be presented based on Monte-Carlo sampling and Markov chain. The objectives of BMC are to propose a reference calculation for validating the GLS calculations and approximations, to test probability density distributions effects and to provide the framework of finding global minimum if several local minimums exist. Application to resolved resonance, unresolved resonance and continuum evaluation as well as multigroup cross section data assimilation will be presented.

The Gaussian-Lorentzian Sum, Product, and Convolution (Voigt) functions in the context of peak fitting X-ray photoelectron spectroscopy (XPS) narrow scans

NASA Astrophysics Data System (ADS)

Jain, Varun; Biesinger, Mark C.; Linford, Matthew R.

2018-07-01

X-ray photoelectron spectroscopy (XPS) is arguably the most important vacuum technique for surface chemical analysis, and peak fitting is an indispensable part of XPS data analysis. Functions that have been widely explored and used in XPS peak fitting include the Gaussian, Lorentzian, Gaussian-Lorentzian sum (GLS), Gaussian-Lorentzian product (GLP), and Voigt functions, where the Voigt function is a convolution of a Gaussian and a Lorentzian function. In this article we discuss these functions from a graphical perspective. Arguments based on convolution and the Central Limit Theorem are made to justify the use of functions that are intermediate between pure Gaussians and pure Lorentzians in XPS peak fitting. Mathematical forms for the GLS and GLP functions are presented with a mixing parameter m. Plots are shown for GLS and GLP functions with mixing parameters ranging from 0 to 1. There are fundamental differences between the GLS and GLP functions. The GLS function better follows the 'wings' of the Lorentzian, while these 'wings' are suppressed in the GLP. That is, these two functions are not interchangeable. The GLS and GLP functions are compared to the Voigt function, where the GLS is shown to be a decent approximation of it. Practically, both the GLS and the GLP functions can be useful for XPS peak fitting. Examples of the uses of these functions are provided herein.

Improving the Strength of the ZrC-SiC and TC4 Brazed Joint Through Fabricating Graded Double-Layered Composite Structure on TC4 Surface

NASA Astrophysics Data System (ADS)

Shi, J. M.; Zhang, L. X.; Chang, Q.; Sun, Z.; Feng, J. C.; Ma, N.

2018-06-01

In order to improve the ZrC-SiC ceramic and TC4 brazed joint property, graded double-layered SiC particles (SiCp)-reinforced TC4-based composite structure (named as GLS for convenience) was designed to relieve the residual stress in the joint. The GLS was successfully fabricated on TC4 substrate by double-layered laser deposition technology before the brazing process. The investigation of the GLS shows that the volume fraction of SiCp in the two composite layers was graded (20 and 39 vol pct, respectively). Ti5Si3 and TiC phases formed in the GLS due to the reaction of SiCp and TC4. The laser power-II (the laser power for the second deposition layer) affected the microstructure of the GLS significantly. Increasing the laser power-II would promote the reaction between the SiCp and TC4. But the high laser power-II made the layer I remelt completely and the two layers became homogeneous rather than graded structure. In the ZrC-SiC and TC4 brazed joint, the CTE (coefficient of thermal expansion) was graded from the TC4 to the ZrC-SiC due to the GLS, and the strength of the joint with the GLS (91 MPa) was higher than that without the GLS (43 MPa).

Modulation of oxidative responses by a virulent isolate of Colletotrichum fructicola in apple leaves.

PubMed

Velho, Aline Cristina; Rockenbach, Mathias F; Mondino, Pedro; Stadnik, Marciel J

2016-10-01

Apple bitter rot (ABR) and Glomerella leaf spot (GLS) can be caused by Colletotrichum fructicola. Although both diseases can occur simultaneously in orchards, some isolates show clear organ specialization. Thus, this work was aimed to compare microscopically the development of preinfective structures of ABR- and GLS isolates and their impact on the enzymatic oxidant defense system during the leaf infection process. On leaves, conidial germlings of GLS-isolate formed appressoria mostly sessile. In contrast, those of ABR-isolate were pedicellate and formed multiple melanized appressoria probably as a sign of unsuccessful infection attempts. Neither ABR- nor GLS isolate triggered hypersensitive response in apple leaves. In overall, the activity of scavenging enzymes was higher and long-lasting in leaves inoculated by GLS- than by ABR isolate and control. Guaiacol peroxidase, catalase, and glutathione reductase had activity peaks within 24 h after inoculation (HAI). Ascorbate peroxidase activity was higher only in GLS-infected leaves at 6 HAI, while superoxide dismutase remained unaltered. A lower level of hydrogen peroxide (H2O2) was determined in GLS-infected plants at 48 HAI, but the electrolyte leakage markedly increased. Disease symptoms in leaves were only caused by GLS-isolate. Results suggest that the virulent isolate coordinately downregulates the oxidative plant defense responses enabling its successful establishment in apple leaves. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Global Longitudinal Strain Using Speckle-Tracking Echocardiography as a Mortality Predictor in Sepsis: A Systematic Review.

PubMed

Vallabhajosyula, Saraschandra; Rayes, Hamza A; Sakhuja, Ankit; Murad, Mohammad Hassan; Geske, Jeffrey B; Jentzer, Jacob C

2018-01-01

The data on speckle-tracking echocardiography (STE) in patients with sepsis are limited. This systematic review from 1975 to 2016 included studies in adults and children evaluating cardiovascular dysfunction in sepsis, severe sepsis, and septic shock utilizing STE for systolic global longitudinal strain (GLS). The primary outcome was short- or long-term mortality. Given the significant methodological and statistical differences between published studies, combining the data using meta-analysis methods was not appropriate. A total of 120 studies were identified, with 5 studies (561 patients) included in the final analysis. All studies were prospective observational studies using the 2001 criteria for defining sepsis. Three studies demonstrated worse systolic GLS to be associated with higher mortality, whereas 2 did not show a statistically significant association. Various cutoffs between -10% and -17% were used to define abnormal GLS across studies. This systematic review revealed that STE may predict mortality in patients with sepsis; however, the strength of evidence is low due to heterogeneity in study populations, GLS technologies, cutoffs, and timing of STE. Further dedicated studies are needed to understand the optimal application of STE in patients with sepsis.

Central Obesity is the Key Component in the Association of Metabolic Syndrome With Left Ventricular Global Longitudinal Strain Impairment.

PubMed

Cañon-Montañez, Wilson; Santos, Angela B S; Nunes, Lisandra A; Pires, Julio C G; Freire, Claudia M V; Ribeiro, Antonio L P; Mill, José G; Bessel, Marina; Duncan, Bruce B; Schmidt, Maria Inês; Foppa, Murilo

2017-11-13

Subclinical systolic dysfunction is one of the proposed mechanisms for increased cardiovascular risk associated with metabolic syndrome (MS). This study investigated the association between MS and impaired left ventricular global longitudinal strain (GLS) and the role of each MS criteria in this association. We analyzed a random sample of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) after excluding participants with prevalent heart disease. Among the 1055 participants fulfilling the inclusion criteria (53% women; 52±9 years), 444 (42%) had MS. Those with MS had worse GLS (-18.0%±2.5%) than those without (-19.0%±2.4%; P<.0001). In multiple linear regression models, MS was associated with worse GLS after adjustment for various risk factors (GLS difference=0.86%; P <.0001), even after inclusion of body mass index. Adjusted PR for impaired GLS as assessed by 3 cutoffs (1, 1.5, and 2 standard deviations) were higher among participants with than without MS: GLS -16.1% (PR, 1.76; 95%CI, 1.30-2.39); GLS -14.8% (PR, 2.35; 95%CI, 1.45-3.81); and GLS -13.5% (PR, 2.07; 95%CI, 0.97-4.41). After inclusion of body mass index in the models, these associations were attenuated, suggesting that they may, at least in part, be mediated by obesity. In quantile regression analyses, elevated waist circumference was the only MS component found to be independently associated with GLS across the whole range of values. Metabolic syndrome is independently associated with impaired GLS. Among the MS criteria, central obesity best depicted the link between metabolic derangement and cardiac function. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Usefulness of layer-specific strain for identifying complex CAD and predicting the severity of coronary lesions in patients with non-ST-segment elevation acute coronary syndrome: Compared with Syntax score.

PubMed

Zhang, Li; Wu, Wei-Chun; Ma, Hong; Wang, Hao

2016-11-15

Layer-specific strain allows the assessment of the function of every layer of myocardium. To evaluate the changes of non-ST-segment elevation acute coronary syndrome(NSTE-ACS) patients with and without complex coronary artery disease(CAD) by layer-specific strain and determine if myocardial strain can identify complex CAD and assess the severity of coronary lesions as defined by Syntax score (SS). A total of 139 patients undergoing coronary angiography due to suspected NSTE-ACS were prospectively enrolled. Echocardiography was performed 1h before angiography. Global longitudinal strain (GLS), territorial longitudinal strain (TLS), global circumferential strain (GCS) and territorial circumferential strain (TCS) of the three layers of LV wall were assessed by two-dimensional (2D) speckle tracking echocardiography (STE) with layer-specific myocardial deformation quantitative analysis based on the perfusion territories of the three major coronary arteries in an 18-segment model of LV. SS was used for predicting the severity of coronary lesions in patients with complex CAD. 78 had complex CAD, 32 had 1- or 2-vessel disease and 29 had no significant coronary stenosis confirmed by coronary angiography. According to SS value, 78 complex CAD subjects were subdivided into three groups, 24 in group SS 1 (SS≤22), 26 in group SS 2 (SS 23-32) and 28 in group SS 3 (SS≥33). Compared to the other two groups without complex CAD, patients with NSTE-ACS due to complex CAD had worse function in all 3 myocardial layers assessed by GLS, TLS, GCS and TCS. Endocardial GLS and TLS (all, P<0.01) were most affected. The absolute differences between endocardial and epicardial GLS and TLS were lower in magnitude in patients with complex CAD than in those without (all, P<0.001), and the more complex of coronary lesion, the lower magnitude of the parameters(all, P<0.001). Endocardial GLS and TLS were closely correlated with SS value(r=-0.751 and r=-0.753, respectively; P<0.001). By receiver-operating characteristic curve analysis, endocardial GLS and TLS demonstrated the highest area under curve, showing better diagnostic accuracy (endocardial GLS: value<-21.35% had 72% sensitivity, 84% specificity and area under the curve ¼0.846; endocardial TLS: value<-20.15% had 72% sensitivity, 88% specificity and area under the curve ¼0.852) than GCS, TCS, mid-myocardial and epicardial GLS, and TLS(all, P<0.05). Strains, particularly endocardial GLS and TLS measurement by 2DSTE might enable a non-invasive method to identify complex CAD and predict the severity of coronary lesions in patients with NSTE-ACS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Additive Prognostic Value of Left Ventricular Systolic Dysfunction in a Population-Based Cohort.

PubMed

Kuznetsova, Tatiana; Cauwenberghs, Nicholas; Knez, Judita; Yang, Wen-Yi; Herbots, Lieven; D'hooge, Jan; Haddad, Francois; Thijs, Lutgarde; Voigt, Jens-Uwe; Staessen, Jan A

2016-07-01

Techniques of 2-dimensional speckle tracking enable the measurement of myocardial deformation (strain) during systole. Recent clinical studies explored the prognostic role of left ventricular global longitudinal strain (GLS). However, there are few data on the association between cardiovascular outcome and GLS in the community. Therefore, we hypothesized that GLS contains additive prognostic information over and beyond traditional cardiovascular risk factors in a large, population-based cohort. We measured GLS by 2-dimensional speckle tracking in the apical 4-chamber view in 791 participants (mean age 50.9 years). We calculated multivariable adjusted hazard ratios for midwall, endocardial, and epicardial GLS, while accounting for family cluster and cardiovascular risk factors. Median follow-up was 7.9 years (5th to 95th percentile, 3.7-9.6). In continuous analysis, with adjustments applied for covariables, midwall, endocardial, and epicardial GLS were significant predictors of fatal and nonfatal cardiovascular (n=96; P<0.0001) and cardiac events (n=68; P≤0.001). In the sex-specific low quartile of midwall GLS (<18.8% in women and <17.4% in men), the risk was significantly higher than the average population risk for cardiovascular (128%, P<0.0001) and cardiac (94%, P=0.0007) events. We also noticed that the risk for cardiovascular events increased with increasing number of left ventricular abnormalities, such as low GLS, diastolic dysfunction, and hypertrophy (log-rank P<0.0001). Low GLS measured by 2-dimensional speckle tracking predicts future cardiovascular events independent of conventional risk factors. Left ventricular midwall strain represents a simple echocardiographic measure, which might be used for assessing cardiovascular risk in a population-based cohort. © 2016 American Heart Association, Inc.

Utilizing pretreatment and fungal incubation to enhance the nutritional value of canola meal.

PubMed

Croat, J R; Karki, B; Berhow, M; Iten, L; Muthukumarappan, K; Gibbons, W R

2017-08-01

The objective of this study was to determine the optimal pretreatment and fungal strain to reduce glucosinolates (GLS), fibre and residual sugars while increasing the nutritional value of canola meal. Submerged incubation conditions were used to evaluate four pretreatment methods (extrusion, hot water cook, dilute acid and dilute alkali) and three fungal cultures (Aureobasidium pullulans Y-2311-1, Fusarium venenatum NRRL-26139 and Trichoderma reesei NRRL-3653) in hexane-extracted (HE) and cold-pressed (CP) canola meal. The combination of extrusion pretreatment followed by incubation with T. reesei resulted in the greatest overall improvement to HE canola meal, increasing protein to 51·5%, while reducing NDF, GLS and residual sugars to 18·6%, 17·2 μmol l -1  g -1 and 5% w/w, respectively. Extrusion pretreatment and incubation with F. venenatum performed the best with CP canola meal, resulting in 54·4% protein while reducing NDF, GLS and residual sugars to 11·6%, 6·7 μmol l -1  g -1 and 3·8% w/w respectively. The work is significant in that it provides a method of reducing GLS (up to 98%) and neutral detergent fibre (up to 65%) while increasing the protein content (up to 45%) of canola meal. This novel pretreatment and submerged incubation process could be used to produce a canola product with higher nutritional value for livestock consumption. © 2017 The Society for Applied Microbiology.

Metabolic profiling of glucosinolates and their hydrolysis products in a germplasm collection of Brassica rapa turnips.

PubMed

Klopsch, Rebecca; Witzel, Katja; Börner, Andreas; Schreiner, Monika; Hanschen, Franziska S

2017-10-01

About 10% of the world's vegetable production is generated from Brassicaceae, wherein Brassica rapa is a dominating species. There is growing evidence that glucosinolates (GLSs), main plant secondary metabolites in Brassicales, play an important role in promoting human health. Natural genetic diversity of B. rapa can be explored for vegetable improvement. We analyzed leaves and tubers of 16 B. rapa turnips for their GLS composition by UHPLC-DAD and the corresponding hydrolysis products by GC-MS. Thirteen GLSs were identified, 8 aliphatic, 4 indolic and one aromatic. 3-Butenyl GLS was prevailing in both plant organs while in tubers 2-hydroxy-3-butenyl GLS and 2-phenylethyl GLS occurred in high amounts. A total of 24 GLS breakdown products were detected in tubers and 16 in leaves. Epithionitriles were the main hydrolysis products in both plant organs with 4,5-epithiopentanenitrile and 3-hydroxy-4,5-epithiopentanenitrile being the main compounds. When comparing leaves and tubers, an accumulation of GLSs and their breakdown products was observed in tubers compared to leaves. Our analysis achieved the comprehensive profiling of all GLS metabolites in a collection of B. rapa turnips, underlining the natural variation not only of intact GLS, but also of their breakdown products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exercise-induced changes in left ventricular global longitudinal strain in asymptomatic severe aortic stenosis.

PubMed

Lech, Agnieszka K; Dobrowolski, Piotr P; Klisiewicz, Anna; Hoffman, Piotr

2017-01-01

The management of patients with asymptomatic severe aortic stenosis (ASAS) is still under discussion. Therefore, it is advisable to search for the parameters of early damage to left ventricular (LV) function. The aim of the study was to assess exercise-induced changes in LV global longitudinal strain (GLS) in ASAS. The ASAS group consisted of 50 patients (26 women and 24 men, aged 38.4 ± 18.1 years) meeting the echocardiographic criteria of severe aortic stenosis (AVA < 1 cm², AVAI < 0.6 cm²/m², Vmax > 4 m/s, mean aortic gradient > 40 mm Hg), with normal LV ejection fraction (LVEF ≥ 55%) and sinus rhythm on electrocardiogram, and without significant concomitant valvular heart diseases. The control group consisted of 21 people matched for age and sex. Echocardiographic examinations and echocardiographic stress tests with the assessment of GLS using the speckle tracking imaging were performed. The ASAS group was characterised by statistically significantly higher LV mass index (LVMI) and higher LVEF. GLS values at rest in both groups were within normal limits but were significantly higher in the control group (-18.9 ± 2.4% vs. -20.7 ± 1.7%, p = 0.006). An increase in GLS at peak exercise in both groups was observed, lower in the ASAS group (the difference was not statistically significant: -0.8 ± 3.0% vs. -2.2 ± 3.1%, p = 0.086). Changes in GLS during exercise (ΔGLS) did not correlate with the parameters of the severity of aortic stenosis. In the multivariate model, LVMI proved to be a factor associated with GLS at rest and during exercise. In patients with ASAS, GLS is a non-invasive marker of an early stage of LV myocardial damage associated with myocardial hypertrophy. An increase in GLS during exercise in the ASAS group, smaller than in the control group, indicates a preserved functional reserve of the LV myocardium but smaller than in healthy individuals. The assessment of the clinical usefulness of exercise-induced changes in GLS requires further research.

Expression of Gls and Gls2 glutaminase isoforms in astrocytes.

PubMed

Cardona, Carolina; Sánchez-Mejías, Elisabeth; Dávila, José C; Martín-Rufián, Mercedes; Campos-Sandoval, José A; Vitorica, Javier; Alonso, Francisco J; Matés, José M; Segura, Juan A; Norenberg, Michael D; Rama Rao, Kakulavarapu V; Jayakumar, Arumugan R; Gutiérrez, Antonia; Márquez, Javier

2015-03-01

The expression of glutaminase in glial cells has been a controversial issue and matter of debate for many years. Actually, glutaminase is essentially considered as a neuronal marker in brain. Astrocytes are endowed with efficient and high capacity transport systems to recapture synaptic glutamate which seems to be consistent with the absence of glutaminase in these glial cells. In this work, a comprehensive study was devised to elucidate expression of glutaminase in neuroglia and, more concretely, in astrocytes. Immunocytochemistry in rat and human brain tissues employing isoform-specific antibodies revealed expression of both Gls and Gls2 glutaminase isozymes in glutamatergic and GABAergic neuronal populations as well as in astrocytes. Nevertheless, there was a different subcellular distribution: Gls isoform was always present in mitochondria while Gls2 appeared in two different locations, mitochondria and nucleus. Confocal microscopy and double immunofluorescence labeling in cultured astrocytes confirmed the same pattern previously seen in brain tissue samples. Astrocytic glutaminase expression was also assessed at the mRNA level, real-time quantitative RT-PCR detected transcripts of four glutaminase isozymes but with marked differences on their absolute copy number: the predominance of Gls isoforms over Gls2 transcripts was remarkable (ratio of 144:1). Finally, we proved that astrocytic glutaminase proteins possess enzymatic activity by in situ activity staining: concrete populations of astrocytes were labeled in the cortex, cerebellum and hippocampus of rat brain demonstrating functional catalytic activity. These results are relevant for the stoichiometry of the Glu/Gln cycle at the tripartite synapse and suggest novel functions for these classical metabolic enzymes. © 2014 Wiley Periodicals, Inc.

Prognosis of Light Chain Amyloidosis With Preserved LVEF: Added Value of 2D Speckle-Tracking Echocardiography to the Current Prognostic Staging System.

PubMed

Barros-Gomes, Sergio; Williams, Brittney; Nhola, Lara F; Grogan, Martha; Maalouf, Joseph F; Dispenzieri, Angela; Pellikka, Patricia A; Villarraga, Hector R

2017-04-01

This study evaluated whether 2-dimensional speckle-tracking echocardiography (2D-STE) has incremental value for prognosis over traditional clinical, echocardiographic, and serological markers-with main focus on the current prognostic staging system-in light-chain (AL) amyloidosis patients with preserved left ventricular ejection fraction. Cardiac amyloidosis (CA) is the major determinant of outcome in AL amyloidosis. The current prognostic staging system is based primarily on serum levels of cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and free light chain differential (FLC-diff). Consecutive patients with biopsy-proven AL amyloidosis and left ventricular ejection fraction ≥55% were divided into group 1 with CA (n = 63) and group 2 without CA (n = 87). Global longitudinal strain (GLS) by 2D-STE was performed with Vivid E9 (GE Healthcare Co., Milwaukee, Wisconsin) and syngo Velocity Vector Imaging (VVI) software (Siemens Medical Solutions USA, Inc., Malvern, Pennsylvania) (GLS GE and GLS VVI , respectively). Thirty-two deaths (51%) occurred in group 1 and 13 (15%) in group 2 (p ≤ 0.001). Group 1 had thicker walls, lower early diastolic tissue Doppler velocity at septal mitral annulus, and greater left ventricular mass, left atrial volume, glomerular filtration rate, FLC-diff, cTnT, and NT-proBNP (p < 0.001). For the entire cohort, GLS GE  ≥ -14.81, GLS VVI ≥-15.02, cTnT, NT-proBNP, FLC-diff, age, left ventricular wall thickness, early diastolic tissue Doppler velocity at septal mitral annulus, diastolic dysfunction grade, glomerular filtration rate, deceleration time, and left atrial volume were univariate predictors of death. In a multivariate Cox model, GLS GE ≥-14.81 (hazard ratio [HR]: 2.68; 95% confidence interval [CI]: 1.07 to 7.13; p = 0.03), FLC-diff, NT-proBNP, and age were independent predictors of survival. There was also a strong trend for GLS VVI ≥-15.02 (HR: 2.44; 95% CI: 0.98 to 6.33; p = 0.055). Using a nested logistic regression model, GLS GE (p = 0.03) and GLS VVI (p = 0.05) provided incremental prognostic value over cTnT, NT-proBNP, and FLC-diff. For survival analysis limited to group 2 (non-CA), GLS GE and GLS VVI both predicted all-cause mortality (GLS GE HR: 1.23; 95% CI: 1.03 to 1.47 [p = 0.02]; GLS VVI HR: 1.22; 95% CI: 1.01 to 1.49 [p = 0.04], respectively). 2D-STE predicted outcome and provided incremental prognostic information over the current prognostic staging system, especially in the group without CA. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

GLS-Finder: An Automated Data-Mining System for Fast Profiling Glucosinolates and its Application in Brassica Vegetables

USDA-ARS?s Scientific Manuscript database

A rapid computer-aided program for profiling glucosinolates, “GLS-Finder", was developed. GLS-Finder is a Matlab script based expert system that is capable for qualitative and semi-quantitative analysis of glucosinolates in samples using data generated by ultra-high performance liquid chromatograph...

[18F](2S,4R)4-Fluoroglutamine PET Detects Glutamine Pool Size Changes in Triple Negative Breast Cancer in Response to Glutaminase Inhibition

PubMed Central

Pantel, Austin R.; Li, Shihong; Lieberman, Brian P.; Ploessl, Karl; Choi, Hoon; Blankemeyer, Eric; Lee, Hsiaoju; Kung, Hank F.; Mach, Robert H.

2017-01-01

Glutaminolysis is a metabolic pathway adapted by many aggressive cancers, including triple-negative breast cancers (TNBC), to utilize glutamine for survival and growth. In this study, we examined the utility of [18F](2S,4R)4-fluoroglutamine ([18F]4F-Gln) PET to measure tumor cellular glutamine pool size, whose change might reveal the pharmacodynamic (PD) effect of drugs targeting this cancer-specific metabolic pathway. High glutaminase (GLS) activity in TNBC tumors resulted in low cellular glutamine pool size assayed via high-resolution 1H magnetic resonance spectroscopy (MRS). GLS inhibition significantly increased glutamine pool size in TNBC tumors. MCF-7 tumors, with inherently low GLS activity compared to TNBC, displayed a larger baseline glutamine pool size that did not change as much in response to GLS inhibition. The tumor-to-blood-activity-ratios (T/B) obtained from [18F]4F-Gln PET images matched the distinct glutamine pool sizes of both tumor models at baseline. After a short course of GLS inhibitor treatment, the T/B values increased significantly in TNBC, but did not change in MCF-7 tumors. Across both tumor types and after GLS inhibitor or vehicle treatment, we observed a strong positive correlation between T/B values and tumor glutamine pool size measured using MRS (R2=0.71). In conclusion, [18F]4F-Gln PET tracked cellular glutamine pool size in breast cancers with differential GLS activity and detected increases in cellular glutamine pool size induced by GLS inhibitors. This study accomplished the first necessary step towards validating [18F]4F-Gln PET as a PD marker for glutaminase-targeting drugs. PMID:28202527

Association of Low-Grade Albuminuria with Adverse Cardiac Mechanics: Findings from the HyperGEN Study

PubMed Central

Katz, Daniel H.; Selvaraj, Senthil; Aguilar, Frank G.; Martinez, Eva E.; Beussink, Lauren; Kim, Kwang-Youn A.; Peng, Jie; Sha, Jin; Irvin, Marguerite R.; Eckfeldt, John H.; Turner, Stephen T.; Freedman, Barry I.; Arnett, Donna K.; Shah, Sanjiv J.

2013-01-01

Introduction Albuminuria is a marker of endothelial dysfunction and has been associated with adverse cardiovascular outcomes. The reasons for this association are unclear, but may be due to the relationship between endothelial dysfunction and intrinsic myocardial dysfunction. Methods and Results In the HyperGEN study, a population- and family-based study of hypertension, we examined the relationship between urine albumin-to-creatinine ratio (UACR) and cardiac mechanics (N=1894, all of whom had normal left ventricular ejection fraction and wall motion). We performed speckle-tracking echocardiographic analysis to quantify global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS, respectively), and early diastolic (e′) tissue velocities. We used E/e′ ratio as a marker of increased LV filling pressures. We used multivariable-adjusted linear mixed effect models to determine independent associations between UACR and cardiac mechanics. The mean age was 50±14 years, 59% were female, and 46% were African-American. Comorbidities were increasingly prevalent among higher UACR quartiles. Albuminuria was associated with GLS, GCS, GRS, e′ velocity, and E/e′ ratio on unadjusted analyses. After adjustment for covariates, UACR was independently associated with lower absolute GLS (multivariable-adjusted mean GLS [95% CI] for UACR Quartile 1 = 15.3 [15.0–15.5]% vs. UACR Q4 = 14.6 [14.3–14.9]%, P for trend <0.001) and increased E/e′ ratio (Q1 = 25.3 [23.5–27.1] vs. Q4 = 29.0 [27.0–31.0], P= 0.003). The association between UACR and GLS was present even in participants with UACR < 30 mg/g (P<0.001 after multivariable adjustment). Conclusions Albuminuria, even at low levels, is associated with adverse cardiac mechanics and higher E/e′ ratio. PMID:24077169

Effect of Sustained Elevated Gastric pH Levels on Gefitinib Exposure.

PubMed

Tang, Weifeng; Tomkinson, Helen; Masson, Eric

2017-09-01

This open-label, randomized, phase 1 crossover study investigated the effect of elevated gastric pH level (>5) on the relative bioavailability and pharmacokinetic profile of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib. Healthy male volunteers (n = 26) were randomized to gefitinib 250 mg (fasted), either alone on day 1 (unmodified gastric pH) or 1 hour following the second of 2 oral doses of the H 2 -receptor antagonist ranitidine 450 mg (elevated gastric pH). After a 3-week washout period, volunteers crossed to the other treatment. The geometric least-squares (GLS) mean AUC 0-∞ and C max for gefitinib were reduced by 47% and 71%, respectively, under conditions of sustained elevated gastric pH; for both parameters, the 90%CI for the ratio of the GLS means lay below the prespecified lower limit. Median t max was delayed from 5 to 6 hours. Mean t 1/2 was similar under both gastric pH conditions. No serious adverse events were reported. The bioavailability of a single oral gefitinib 250-mg dose was reduced by approximately 50% when gefitinib was administered under conditions of sustained elevated gastric pH. © 2017, The American College of Clinical Pharmacology.

Modern separation techniques coupled to high performance mass spectrometry for glycolipid analysis.

PubMed

Sarbu, Mirela; Zamfir, Alina Diana

2018-01-21

Glycolipids (GLs), involved in biological processes and pathologies, such as viral, neurodegenerative and oncogenic transformations are in the focus of research related to method development for structural analysis. This review highlights modern separation techniques coupled to mass spectrometry (MS) for the investigation of GLs from various biological matrices. First section is dedicated to methods, which, although provide the separation in a non-liquid phase, are able to supply important data on the composition of complex mixtures. While classical thin layer chromatography (TLC) is useful for MS analyses of the fractionated samples, ultramodern ion mobility (IMS) characterized by high reproducibility facilitates to discover minor species and to apply low sample amounts, in addition to providing conformational separation with isomer discrimination. Second section highlights the advantages, applications and limitations of liquid-based separation techniques such as high performance liquid chromatography (HPLC) and hydrophilic interaction liquid chromatography (HILIC) in direct or indirect coupling to MS for glycolipidomics surveys. The on- and off-line capillary electrophoresis (CE) MS, offering a remarkable separation efficiency of GLs is also presented and critically assessed from the technical and application perspective in the final part of the review. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluating the Analgesic Effect of the GLS Inhibitor 6-Diazo-5-Oxo-L-Norleucine in Vivo

PubMed Central

Crosby, Heith A; Miller, Kenneth E

2018-01-01

Glutamate is an excitatory neurotransmitter, produced by its synthetic enzyme, glutaminase (GLS), and packaged by vesicular transporters (VGluT2) into synaptic vesicles. Primary sensory peripheral nerve and spinal synaptic terminals release glutamate during nociceptive (pain) signaling. In post-incisional and inflammation models in rats, GLS and VGluT2 production is elevated in dorsal root ganglion neuronal cell bodies and transported to peripheral and spinal terminals for increased glutamate synthesis and release. 6-Diazo-5-oxo-l-norleucine (DON) is a GLS inhibitor that produces long lasting pain relief when applied to the inflamed paw of arthritic rats, but its effect in a post-incisional model has not been evaluated. In this study, we examined the analgesic efficacy of DON in a surgical incision model by measuring thermal latency and mechanical allodynia. Following behavioral evaluation, we examined the skin for VGluT2, GLS and glutamate immunoreactivity (ir). Our findings revealed that VGluT2-ir is elevated in the stratum lucidum by approximately 19%, 64 hours post-surgical incision and attenuated by approximately 5.4% after the administration of DON. During that same period GLS-ir was elevated in dermal nerve fibers by 52% and was attenuated by approximately 27.9% after the application of DON. Additionally, glutamate-ir was elevated in epidermal nerve fibers by 35% after incision and attenuated by approximately 23% after the administration of DON. Behavioral testing 24 and 48 hours after a single local administration of DON showed five out of six animals having an analgesic response to mechanical allodynia, but not to thermal hyperalgesia. Following a surgical incision, the area of injury shows increased VGluT2-, GLS-, glutamate-ir, mechanical allodynia and no change in thermal latency. After the application of the GLS inhibitor, DON, nerve fiber of the skin showed decreased VGluT2, GLS, and glutamate-ir. Furthermore, post-incision DON treated animals exhibited decreased mechanical allodynia with no change in thermal latency when compared to control animals. PMID:29888760

Effect of the Garrett Lee Smith Memorial Suicide Prevention Program on Suicide Attempts Among Youths.

PubMed

Godoy Garraza, Lucas; Walrath, Christine; Goldston, David B; Reid, Hailey; McKeon, Richard

2015-11-01

Youth suicide prevention is a major public health priority. Studies documenting the effectiveness of community-based suicide prevention programs in reducing the number of nonlethal suicide attempts have been sparse. To determine whether a reduction in suicide attempts among youths occurs following the implementation of the Garrett Lee Smith Memorial Suicide Prevention Program (hereafter referred to as the GLS program), consistent with the reduction in mortality documented previously. We conducted an observational study of community-based suicide prevention programs for youths across 46 states and 12 tribal communities. The study compared 466 counties implementing the GLS program between 2006 and 2009 with 1161 counties that shared key preintervention characteristics but were not exposed to the GLS program. The unweighted rounded numbers of respondents used in this analysis were 84 000 in the control group and 57 000 in the intervention group. We used propensity score-based techniques to increase comparability (on background characteristics) between counties that implemented the GLS program and counties that did not. We combined information on program activities collected by the GLS national evaluation with information on county characteristics from several secondary sources. The data analysis was performed between April and August 2014. P < .05 was considered statistically significant. Comprehensive, multifaceted suicide prevention programs, including gatekeeper training, education and mental health awareness programs, screening activities, improved community partnerships and linkages to service, programs for suicide survivors, and crisis hotlines. Suicide attempt rates for each county following implementation of the GLS program for youths 16 to 23 years of age at the time the program activities were implemented. We obtained this information from the National Survey on Drug Use and Health administered to a large national probabilistic sample between 2008 and 2011. Counties implementing GLS program activities had significantly lower suicide attempt rates among youths 16 to 23 years of age in the year following implementation of the GLS program than did similar counties that did not implement GLS program activities (4.9 fewer attempts per 1000 youths [95% CI, 1.8-8.0 fewer attempts per 1000 youths]; P = .003). More than 79 000 suicide attempts may have been averted during the period studied following implementation of the GLS program. There was no significant difference in suicide attempt rates among individuals older than 23 years during that same period. There was no evidence of longer-term differences in suicide attempt rates. Comprehensive GLS program activities were associated with a reduction in suicide attempt rates. Sustained suicide prevention programming efforts may be needed to maintain the reduction in suicide attempt rates.

miR-137 inhibits glutamine catabolism and growth of malignant melanoma by targeting glutaminase.

PubMed

Luan, Wenkang; Zhou, Zhou; Zhu, Yan; Xia, Yun; Wang, Jinlong; Xu, Bin

2018-01-01

Glutamine catabolism is considered to be an important metabolic pathway for cancer cells. Glutaminase (GLS) is the important rate-limiting enzyme of glutamine catabolism. miR-137 functions as a tumor suppressor in many human malignant tumors. However, the role and molecular mechanism of miR-137 and GLS in malignant melanoma has not been reported. In this study, we showed that miR-137 was decreased in melanoma tissue, and the low miR-137 level and high GLS expression are independent risk factor in melanoma. miR-137 suppressed the proliferation and glutamine catabolism of melanoma cells. GLS is crucial for glutamine catabolism and growth of malignant melanoma. We also demonstrated that miR-137 acts as a tumor suppressor in melanoma by targeting GLS. This result elucidates a new mechanism for miR-137 in melanoma development and provides a survival indicator and potential therapeutic target for melanoma patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Critical Appraisal of Microbiology Guidelines Endorsed by two Professional Organisations: Société Française De Microbiologie (SFM) and American Society of Microbiology (ASM).

PubMed

Fonfrède, Michèle; Couaillac, Jean Paul; Augereau, Christine; Lepargneur, Jean Pierre; Watine, Joseph

2012-07-01

Medical practice guidelines (GLs) being tools that are mainly designed to evaluate medical professionals, it sounds logical, and fair, that professionals should in turn evaluate GLs. Microbiology being a medical discipline, we used the AGREE instrument, i.e. an established evaluation tool for GLs, in order to evaluate the quality of two major microbiology guidelines, i.e. the SFM GLs and the ASM GLs). Both guidelines remain sub-optimal in their levels of quality, and obtain scores that are not very different from the average scores obtained by many other guidelines in various medical disciplines. We therefore believe that both guidelines need to be modified before they can be recommended without provisos. A higher degree of multi-disciplinary work, including a more formal implication of methodologists, as well as of infectious disease clinicians, and of economists, might perhaps enable future editions of these guidelines to reach higher levels of quality.

Head-to-Head Comparison of Global Longitudinal Strain Measurements among Nine Different Vendors: The EACVI/ASE Inter-Vendor Comparison Study.

PubMed

Farsalinos, Konstantinos E; Daraban, Ana M; Ünlü, Serkan; Thomas, James D; Badano, Luigi P; Voigt, Jens-Uwe

2015-10-01

This study was planned by the EACVI/ASE/Industry Task Force to Standardize Deformation Imaging to (1) test the variability of speckle-tracking global longitudinal strain (GLS) measurements among different vendors and (2) compare GLS measurement variability with conventional echocardiographic parameters. Sixty-two volunteers were studied using ultrasound systems from seven manufacturers. Each volunteer was examined by the same sonographer on all machines. Inter- and intraobserver variability was determined in a true test-retest setting. Conventional echocardiographic parameters were acquired for comparison. Using the software packages of the respective manufacturer and of two software-only vendors, endocardial GLS was measured because it was the only GLS parameter that could be provided by all manufactures. We compared GLSAV (the average from the three apical views) and GLS4CH (measured in the four-chamber view) measurements among vendors and with the conventional echocardiographic parameters. Absolute values of GLSAV ranged from 18.0% to 21.5%, while GLS4CH ranged from 17.9% to 21.4%. The absolute difference between vendors for GLSAV was up to 3.7% strain units (P < .001). The interobserver relative mean errors were 5.4% to 8.6% for GLSAV and 6.2% to 11.0% for GLS4CH, while the intraobserver relative mean errors were 4.9% to 7.3% and 7.2% to 11.3%, respectively. These errors were lower than for left ventricular ejection fraction and most other conventional echocardiographic parameters. Reproducibility of GLS measurements was good and in many cases superior to conventional echocardiographic measurements. The small but statistically significant variation among vendors should be considered in performing serial studies and reflects a reference point for ongoing standardization efforts. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Impact of transducer frequency setting on speckle tracking measures.

PubMed

Olsen, Flemming Javier; Svendsen, Jesper Hastrup; Køber, Lars; Højberg, Søren; Haugan, Ketil; Jensen, Jan Skov; Biering-Sørensen, Tor

2018-03-01

Speckle tracking echocardiography is an emerging technique, which is currently being included in clinical guidelines. We sought to investigate the impact of transducer frequency settings on speckle tracking derived measures. The study comprised of 22 subjects prospectively enrolled for a randomized controlled trial (LOOP-study, Clinicaltrials.gov:NCT02036450). Patients were above 70 years of age with increased risk of stroke, and had an echocardiogram performed, which included focused images of the left ventricle. Focused images were obtained with the transducer frequency set at both 1.7/3.3 and 1.5/3.0 MHz. The images were obtained immediately after each other at the exact same position for the two settings. Speckle tracking was performed in three apical projections, allowing for acquisition of layered global longitudinal strain (GLS) and strain rate measures. Concordance between the frequency settings was tested for endo-, mid-, and epicardial GLS and strain rates by coefficients of variation, bias coefficients and visually displayed by Bland-Altman plots. Bland-Altman plots did not reveal any significant over- or underestimation of any speckle tracking measure. Bias coefficients showed that none of the measurements differed significantly between the two settings (bias for GLS endo  = - 0.07 ± 2.94, p = 0.91; GLS mid  = 0.02 ± 2.70, p = 0.98, GLS epi  = 0.07 ± 2.53, p = 0.90). Coefficients of variation were as follows: GLS endo  = 15.11%, GLS mid  = 15.28%, GLS epi  = 17.26%, systolic strain rate = 15.66%, early diastolic strain rate = 38.46%, late diastolic strain rate = 11%. Changing between transducer frequency settings does not systematically derange speckle tracking measures. One can safely reduce the transducer frequency without compromising the validity of speckle tracking derived measures.

Analysis of Point Based Image Registration Errors With Applications in Single Molecule Microscopy

PubMed Central

Cohen, E. A. K.; Ober, R. J.

2014-01-01

We present an asymptotic treatment of errors involved in point-based image registration where control point (CP) localization is subject to heteroscedastic noise; a suitable model for image registration in fluorescence microscopy. Assuming an affine transform, CPs are used to solve a multivariate regression problem. With measurement errors existing for both sets of CPs this is an errors-in-variable problem and linear least squares is inappropriate; the correct method being generalized least squares. To allow for point dependent errors the equivalence of a generalized maximum likelihood and heteroscedastic generalized least squares model is achieved allowing previously published asymptotic results to be extended to image registration. For a particularly useful model of heteroscedastic noise where covariance matrices are scalar multiples of a known matrix (including the case where covariance matrices are multiples of the identity) we provide closed form solutions to estimators and derive their distribution. We consider the target registration error (TRE) and define a new measure called the localization registration error (LRE) believed to be useful, especially in microscopy registration experiments. Assuming Gaussianity of the CP localization errors, it is shown that the asymptotic distribution for the TRE and LRE are themselves Gaussian and the parameterized distributions are derived. Results are successfully applied to registration in single molecule microscopy to derive the key dependence of the TRE and LRE variance on the number of CPs and their associated photon counts. Simulations show asymptotic results are robust for low CP numbers and non-Gaussianity. The method presented here is shown to outperform GLS on real imaging data. PMID:24634573

A new genetic factor for root gravitropism in rice (Oryza sativa L.).

PubMed

Shi, Jiang-hua; Hao, Xi; Wu, Zhong-chang; Wu, Ping

2009-10-01

Root gravitropism is one of the important factors to determine root architecture. To understand the mechanism underlying root gravitropism, we isolated a rice (Xiushui63) mutant defective in root gravitropism, designated as gls1. Vertical sections of root caps revealed that gls1 mutant displayed normal distribution of amyloplast in the columella cells compared with the wild type. The gls1 mutant was less sensitive to 2,4-dichlorophenoxyacetic acid (2,4-D) and alpha-naphthaleneacetic acid (NAA) than the wild type. Genetic analysis indicated that the phenotype of gls1 mutant was caused by a single recessive mutation, which is mapped in a 255-kb region between RM16253 and CAPS1 on the short arm of chromosome 4.

Echocardiographic strain and mortality in Black Americans with end-stage renal disease on hemodialysis.

PubMed

Pressman, Gregg S; Seetha Rammohan, Harish Raj; Romero-Corral, Abel; Fumo, Peter; Figueredo, Vincent M; Gorcsan, John

2015-11-15

End-stage renal disease (ESRD) presents a significant health burden and is associated with high cardiovascular morbidity and mortality. This is particularly true in African Americans who generally have higher rates of cardiovascular mortality. Outcomes in ESRD are related to extent of cardiovascular disease, but markers for outcome are not clearly established. Global longitudinal strain (GLS) has emerged as an important measure of left ventricular systolic function that is additive to traditional ejection fraction (EF). It can be measured on routine digital echocardiography and is reproducible. This study tested the hypothesis that GLS is associated with mortality in black Americans with ESRD and preserved EF. Forty-eight outpatients undergoing hemodialysis, 59.4 ± 13.3 years, with EF ≥50% were prospectively enrolled. GLS, measured by an offline speckle tracking algorithm, ranged from -8.6% to -22.0% with a mean of -13.4%, substantially below normal (-16% or more negative). The prevalence of left ventricular systolic dysfunction, as determined by GLS, was 89%. Patients were followed for an average of 1.9 years; all-cause mortality was 19% (9 deaths). GLS was significantly associated with mortality (hazard ratio 1.15, 95% confidence interval 1.02 to 1.30, p = 0.02), whereas EF was not. After adjustment for multiple potential confounders (age, gender, race, smoking, hypertension, diabetes, hyperlipidemia, coronary disease, heart failure, and EF), GLS remained strongly associated with mortality (hazard ratio 1.30, 95% confidence interval 1.10 to 1.56, p = 0.002). In conclusion, GLS is an important index in patients with ESRD, which is additive to EF as a marker for mortality in this high-risk group. Copyright © 2015 Elsevier Inc. All rights reserved.

Detection of Obstructive Coronary Artery Disease Using Peak Systolic Global Longitudinal Strain Derived by Two-Dimensional Speckle-Tracking: A Systematic Review and Meta-Analysis.

PubMed

Liou, Kevin; Negishi, Kazuaki; Ho, Suyen; Russell, Elizabeth A; Cranney, Greg; Ooi, Sze-Yuan

2016-08-01

Global longitudinal strain (GLS) is well validated and has important applications in contemporary clinical practice. The aim of this analysis was to evaluate the accuracy of resting peak GLS in the diagnosis of obstructive coronary artery disease (CAD). A systematic literature search was performed through July 2015 using four databases. Data were extracted independently by two authors and correlated before analyses. Using a random-effect model, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and summary area under the curve for GLS were estimated with their respective 95% CIs. Screening of 1,669 articles yielded 10 studies with 1,385 patients appropriate for inclusion in the analysis. The mean age and left ventricular ejection fraction were 59.9 years and 61.1%. On the whole, 54.9% and 20.9% of the patients had hypertension and diabetes, respectively. Overall, abnormal GLS detected moderate to severe CAD with a pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 74.4%, 72.1%, 2.9, and 0.35 respectively. The area under the curve and diagnostic odds ratio were 0.81 and 8.5. The mean values of GLS for those with and without CAD were -16.5% (95% CI, -15.8% to -17.3%) and -19.7% (95% CI, -18.8% to -20.7%), respectively. Subgroup analyses for patients with severe CAD and normal left ventricular ejection fractions yielded similar results. Current evidence supports the use of GLS in the detection of moderate to severe obstructive CAD in symptomatic patients. GLS may complement existing diagnostic algorithms and act as an early adjunctive marker of cardiac ischemia. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Relations Between Aortic Stiffness and Left Ventricular Mechanical Function in the Community.

PubMed

Bell, Vanessa; McCabe, Elizabeth L; Larson, Martin G; Rong, Jian; Merz, Allison A; Osypiuk, Ewa; Lehman, Birgitta T; Stantchev, Plamen; Aragam, Jayashri; Benjamin, Emelia J; Hamburg, Naomi M; Vasan, Ramachandran S; Mitchell, Gary F; Cheng, Susan

2017-01-09

Aortic stiffness impairs optimal ventricular-vascular coupling and left ventricular systolic function, particularly in the long axis. Left ventricular global longitudinal strain (GLS) has recently emerged as a sensitive measure of early cardiac dysfunction. In this study, we investigated the relation between aortic stiffness and GLS in a large community-based sample. In 2495 participants (age 39-90 years, 57% women) of the Framingham Offspring and Omni cohorts, free of cardiovascular disease, we performed tonometry to measure arterial hemodynamics and echocardiography to assess cardiac function. Aortic stiffness was evaluated as carotid-femoral pulse wave velocity and as characteristic impedance, and GLS was calculated using speckle tracking-based measurements. In multivariable analyses adjusting for age, sex, height, systolic blood pressure, augmentation index, left ventricular structure, and additional cardiovascular risk factors, increased carotid-femoral pulse wave velocity (B±SE: 0.122±0.030% strain per SD, P<0.0001) and characteristic impedance (0.090±0.029, P=0.002) were both associated with worse GLS. We observed effect modification by sex on the relation between characteristic impedance and GLS (P=0.004); in sex-stratified multivariable analyses, the relation between greater characteristic impedance and worse GLS persisted in women (0.145±0.039, P=0.0003) but not in men (P=0.73). Multiple measures of increased aortic stiffness were cross-sectionally associated with worse GLS after adjusting for hemodynamic variables. Parallel reductions in left ventricular long axis shortening and proximal aortic longitudinal strain in individuals with a stiffened proximal aorta, from direct mechanical ventricular-vascular coupling, offers an alternative explanation for the observed relations. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Impact of image quality on reliability of the measurements of left ventricular systolic function and global longitudinal strain in 2D echocardiography.

PubMed

Nagata, Yasufumi; Kado, Yuichiro; Onoue, Takeshi; Otani, Kyoko; Nakazono, Akemi; Otsuji, Yutaka; Takeuchi, Masaaki

2018-03-01

Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) play important roles in diagnosis and management of cardiac diseases. However, the issue of the accuracy and reliability of LVEF and GLS remains to be solved. Image quality is one of the most important factors affecting measurement variability. The aim of this study was to investigate whether improved image quality could reduce observer variability. Two sets of three apical images were acquired using relatively old- and new-generation ultrasound imaging systems (Vivid 7 and Vivid E95) in 308 subjects. Image quality was assessed by endocardial border delineation index (EBDI) using a 3-point scoring system. Three observers measured the LVEF and GLS, and these values and inter-observer variability were investigated. Image quality was significantly better with Vivid E95 (EBDI: 26.8 ± 5.9) than that with Vivid 7 (22.8 ± 6.3, P  < 0.0001). Regarding the inter-observer variability of LVEF, the r -value, bias, 95% limit of agreement and intra-class correlation coefficient for Vivid 7 were comparable to those for Vivid E95. The % variabilities were significantly lower for Vivid E95 (5.3-6.5%) than those for Vivid 7 (6.5-7.5%). Regarding GLS, all observer variability parameters were better for Vivid E95 than for Vivid 7. Improvements in image quality yielded benefits to both LVEF and GLS measurement reliability. Multivariate analysis showed that image quality was indeed an important factor of observer variability in the measurement of LVEF and GLS. The new-generation ultrasound imaging system offers improved image quality and reduces inter-observer variability in the measurement of LVEF and GLS. © 2018 The authors.

Arabidopsis thaliana gonidialess A/Zuotin related factors (GlsA/ZRF) are essential for maintenance of meristem integrity.

PubMed

Guzmán-López, José Alfredo; Abraham-Juárez, María Jazmín; Lozano-Sotomayor, Paulina; de Folter, Stefan; Simpson, June

2016-05-01

Observation of a differential expression pattern, including strong expression in meristematic tissue of an Agave tequilana GlsA/ZRF ortholog suggested an important role for this gene during bulbil formation and developmental changes in this species. In order to better understand this role, the two GlsA/ZFR orthologs present in the genome of Arabidopsis thaliana were functionally characterized by analyzing expression patterns, double mutant phenotypes, promoter-GUS fusions and expression of hormone related or meristem marker genes. Patterns of expression for A. thaliana show that GlsA/ZFR genes are strongly expressed in SAMs and RAMs in mature plants and developing embryos and double mutants showed multiple changes in morphology related to both SAM and RAM tissues. Typical double mutants showed stunted growth of aerial and root tissue, formation of multiple ectopic meristems and effects on cotyledons, leaves and flowers. The KNOX genes STM and BP were overexpressed in double mutants whereas CLV3, WUSCHEL and AS1 were repressed and lack of AtGlsA expression was also associated with changes in localization of auxin and cytokinin. These results suggest that GlsA/ZFR is an essential component of the machinery that maintains the integrity of SAM and RAM tissue and underline the potential to identify new genes or gene functions based on observations in non-model plants.

Vertical electron transport in van der Waals heterostructures with graphene layers

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

Ryzhii, V., E-mail: v-ryzhii@riec.tohoku.ac.jp; Center for Photonics and Infrared Engineering, Bauman Moscow State Technical University and Institute of Ultra High Frequency Semiconductor Electronics of RAS, Moscow 111005; Otsuji, T.

We propose and analyze an analytical model for the self-consistent description of the vertical electron transport in van der Waals graphene-layer (GL) heterostructures with the GLs separated by the barriers layers. The top and bottom GLs serve as the structure emitter and collector. The vertical electron transport in such structures is associated with the propagation of the electrons thermionically emitted from GLs above the inter-GL barriers. The model under consideration describes the processes of the electron thermionic emission from and the electron capture to GLs. It accounts for the nonuniformity of the self-consistent electric field governed by the Poisson equationmore » which accounts for the variation of the electron population in GLs. The model takes also under consideration the cooling of electrons in the emitter layer due to the Peltier effect. We find the spatial distributions of the electric field and potential with the high-electric-field domain near the emitter GL in the GL heterostructures with different numbers of GLs. Using the obtained spatial distributions of the electric field, we calculate the current-voltage characteristics. We demonstrate that the Peltier cooling of the two-dimensional electron gas in the emitter GL can strongly affect the current-voltage characteristics resulting in their saturation. The obtained results can be important for the optimization of the hot-electron bolometric terahertz detectors and different devices based on GL heterostructures.« less

Targeting glutaminase-mediated glutamine dependence in papillary thyroid cancer.

PubMed

Yu, Yang; Yu, Xiaohui; Fan, Chenling; Wang, Hong; Wang, Renee; Feng, Chen; Guan, Haixia

2018-06-25

Papillary thyroid cancer is a prevalent endocrine malignancy. Although alterations in glutamine metabolism have been reported in several types of hematological and solid tumors, little is known about the functions of glutamine and glutaminolysis-associated proteins in papillary thyroid cancer. Here, we demonstrated the glutamine dependence of papillary thyroid cancer cells, and with the use of RT 2 -PCR arrays, we screened for the aberrant overexpression of glutaminase in human papillary thyroid cancer tissues and cells. These results were later confirmed via real-time PCR, Western blots, and immunohistochemical staining. We found that the levels of glutaminase were significantly correlated with extrathyroidal extension. Inhibition of GLS suppressed glutaminolysis and reduced mitochondrial respiration. The proliferative, viable, migratory, and invasive abilities of papillary thyroid cancer cells were impaired by both the pharmacological inhibition and the genetic knockdown of glutaminase. Additionally, the inhibition of glutaminase deactivated the mechanistic target of the rapamycin complex 1 (mTORC1) signaling pathway, promoting autophagy and apoptosis. Collectively, these findings show that glutaminase-mediated glutamine dependence may be a potential therapeutic target for papillary thyroid cancer. PTC cells are glutamine-dependent, and GLS is aberrantly overexpressed in PTC. Inhibition of GLS suppressed glutaminolysis and reduced mitochondrial respiration. Inhibition of GLS impairs the viability of PTC cells. GLS blockade causes deactivation of mTORC1 and induction of autophagy and apoptosis. GLS may be a potential therapeutic target for PTC.

Recent development of small molecule glutaminase inhibitors.

PubMed

Song, Minsoo; Kim, Soong-Hyun; Im, Chun Young; Hwang, Hee-Jong

2018-05-24

Glutaminase (GLS) which is responsible for the conversion of glutamine to glutamate plays vital role in up-regulating cell metabolism for tumor cell growth, and is considered as a valuable therapeutic target for cancer treatment. Based on this important function of glutaminase in cancer, several GLS inhibitors have been developed from both academia and industries. Most importantly, Calithera Biosciences Inc. is actively developing glutaminase inhibitor CB-839 for the treatment of various cancers in phase 1 and 2 clinical trials at present. In this review, it is discussed about recent efforts to develop small molecule glutaminase inhibitors targeting glutamine metabolism both in the preclinical and clinical studies. In particular, more emphasis is placed on CB-839 since it is the only small molecule GLS inhibitor being studied in clinical setting. Inhibition mechanism is discussed based on x-ray structure study of thiadiazole derivatives as well. Finally, recent medicinal chemistry efforts to develop a new class of GLS inhibitors are given herein in the hope of providing useful information for GLS inhibitors of the next generation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Comparison of three blood transfusion guidelines applied to 31 feline donors to minimise the risk of transfusion-transmissible infections.

PubMed

Marenzoni, Maria Luisa; Lauzi, Stefania; Miglio, Arianna; Coletti, Mauro; Arbia, Andrea; Paltrinieri, Saverio; Antognoni, Maria Teresa

2017-08-01

Objectives The increased demand for animal blood transfusions creates the need for an adequate number of donors. At the same time, a high level of blood safety must be guaranteed and different guidelines (GLs) deal with this topic. The aim of this study was to evaluate the appropriateness of different GLs in preventing transfusion-transmissible infections (TTI) in Italian feline blood donors. Methods Blood samples were collected from 31 cats enrolled as blood donors by the owners' voluntary choice over a period of approximately 1 year. Possible risk factors for TTI were recorded. Based on Italian, European and American GLs, specific TTI, including haemoplasmas, feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), Anaplasma phagocytophilum, Ehrlichia species, Bartonella species, Babesia species, Theileria species, Cytauxzoon species, Leishmania donovani sensu lato and feline coronavirus (FCoV) were screened. Rapid antigen and serological tests and biomolecular investigations (PCR) were used. Several PCR protocols for haemoplasma and FeLV DNA were compared. Results The presence of at least one recognised risk factor for TTI was reported in all cats. Results for FIV and FeLV infections were negative using rapid tests, whereas five (16.1%) cats were positive for FCoV antibodies. Four (12.9%) cats were PCR positive for haemoplasma DNA and one (3.2%) for FeLV provirus, the latter being positive only using the most sensitive PCR protocol applied. Other TTI were not detected using PCR. Conclusions and relevance Blood safety increases by combining the recommendations of different GLs. To reduce the risk of TTI, sensitive tests are needed and the choice of the best protocol is a critical step in improving blood safety. The cost and time of the screening procedures may be reduced if appropriate tests are selected. To this end, the GLs should include appropriate recruitment protocols and questionnaire-based risk profiles to identify suitable donors.

Predicting Cardiotoxic Effects of Carbon Monoxide Poisoning Using Speckle Tracking Echocardiography.

PubMed

Saraçoğlu, Erhan; Vuruşkan, Ertan; Kılıç, Salih; Çekici, Yusuf; Onur, Bahaeddin; Arslan, Yavuz; Kılıç, Ertuğrul; Aykut, Ömer

2018-04-01

Carbon monoxide (CO) poisoning could cause significant cardiac injury. This study aimed to evaluate patients with CO poisoning by using speckle tracking echocardiography (STE), a potentially more sensitive technique, to identify left systolic ventricular dysfunction for the first time in the literature. Seventy-two patients who were exposed to CO poisoning were studied. Blood collection and echocardiography were performed at admission and after patients' discharge on days 10-15 (mean 12 days). Global longitudinal strain (GLS) and global circumferential strain (GCS) were calculated using STE. In order to find the normal strain levels and to compare it to the patient with CO poisoning, 35 healthy subjects were included in the study. Left ventricular ejection fraction was analyzed according to Simpson's method. Patients were divided into two groups based on their LVEF values. LVEF < 55%, Group 1 (n = 24); LVEF ≥ 55%, Group 2 (n = 48). The reduction in Group 1 strain levels decreased in correlation with LVEF (p < 0.001) while in Group 2, there were no significant changes in LVEF but strain levels were significantly reduced (p = 0.091; p < 0.001). Compared with the control group patients, admission GLS and GLC values of CO-poisoned patients were significantly low both in Group 1 and 2. On the contrary, no significant difference was observed when compared with follow-up GLS value. For prediction of CO cardiotoxicity, the cutoff value of GLS was ≥ - 19.1 with a sensitivity of 70.3% and a specificity of 100% [(AUC) 0.840, 95% (CI) 0.735-0.916; p < 0.001] in the ROC curve analyses. GLS was found as independent predictors of cardiotoxicity. Our study demonstrates the potential of using systolic strain values obtained using 2D-STE in determining cardiotoxicity due to CO poisoning. Speckle tracking echocardiography has the potential of demonstrating subtle LV systolic dysfunction even in CO poisoning patients with preserved EF.

Local CD34-positive capillaries decrease in mouse models of kidney disease associating with the severity of glomerular and tubulointerstitial lesions.

PubMed

Masum, Md Abdul; Ichii, Osamu; Elewa, Yaser Hosny Ali; Nakamura, Teppei; Kon, Yasuhiro

2017-09-04

The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases. Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05). Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34 + glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34 + tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34 + glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively. From the analysis of mouse models, we identified inverse pathological correlations between the number of local capillaries in GLs and TILs and the severity of kidney diseases.

Lepidosaurian diversity in the Mesozoic-Palaeogene: the potential roles of sampling biases and environmental drivers

NASA Astrophysics Data System (ADS)

Cleary, Terri J.; Benson, Roger B. J.; Evans, Susan E.; Barrett, Paul M.

2018-03-01

Lepidosauria is a speciose clade with a long evolutionary history, but there have been few attempts to explore its taxon richness through time. Here we estimate patterns of terrestrial lepidosaur genus diversity for the Triassic-Palaeogene (252-23 Ma), and compare observed and sampling-corrected richness curves generated using Shareholder Quorum Subsampling and classical rarefaction. Generalized least-squares regression (GLS) is used to investigate the relationships between richness, sampling and environmental proxies. We found low levels of richness from the Triassic until the Late Cretaceous (except in the Kimmeridgian-Tithonian of Europe). High richness is recovered for the Late Cretaceous of North America, which declined across the K-Pg boundary but remained relatively high throughout the Palaeogene. Richness decreased following the Eocene-Oligocene Grande Coupure in North America and Europe, but remained high in North America and very high in Europe compared to the Late Cretaceous; elsewhere data are lacking. GLS analyses indicate that sampling biases (particularly, the number of fossil collections per interval) are the best explanation for long-term face-value genus richness trends. The lepidosaur fossil record presents many problems when attempting to reconstruct past diversity, with geographical sampling biases being of particular concern, especially in the Southern Hemisphere.

Prognostic and Added Value of Two-Dimensional Global Longitudinal Strain for Prediction of Survival in Patients with Light Chain Amyloidosis Undergoing Autologous Hematopoietic Cell Transplantation.

PubMed

Pun, Shawn C; Landau, Heather J; Riedel, Elyn R; Jordan, Jonathan; Yu, Anthony F; Hassoun, Hani; Chen, Carol L; Steingart, Richard M; Liu, Jennifer E

2018-01-01

Autologous hematopoietic cell transplantation (HCT) is a first-line therapy for prolonging survival in patients with light-chain (AL) amyloidosis. Cardiac involvement is the most important determinant of survival. However, patients with advanced cardiac involvement have often been excluded from HCT because of high risk for transplantation-related mortality and poor overall survival. Whether baseline left ventricular global longitudinal strain (GLS) can provide additional risk stratification and predict survival after HCT in this high-risk population remains unclear. The aim of this study was to evaluate the prognostic implication of baseline GLS and the added value of GLS beyond circulating cardiac biomarkers for risk stratification in patients with AL amyloidosis undergoing HCT. Eighty-two patients with newly diagnosed AL amyloidosis who underwent upfront HCT between January 2007 and April 2014 were included in the study. Clinical, echocardiographic, and serum cardiac biomarker data were collected at baseline and 12 months following HCT. GLS measurements were performed using a vendor-independent offline system. The median follow-up time for survivors was 58 months. Sixty-four percent of patients were in biomarker-based Mayo stage II or III. GLS, brain natriuretic peptide, troponin, and mitral E/A ratio were identified as the strongest predictors of survival (P < .0001). Other predictors included sex, creatinine, free AL, wall thickness, and ejection fraction. Mayo stage was significantly associated with outcome, with 5-year survival of 93%, 72% and 31% in stage I, II, and III patients, respectively. GLS of 17% was identified as the value that best discriminated survivors from nonsurvivors, and the application of this cutoff value provided further mortality risk stratification within each Mayo stage. GLS is a strong predictor of survival in patients with AL amyloidosis undergoing HCT, potentially providing incremental value over serum cardiac biomarkers for risk stratification. GLS should be considered as a standard parameter along with serum cardiac biomarkers when evaluating eligibility for HCT or other investigational therapies. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Assessment of global longitudinal strain using standardized myocardial deformation imaging: a modality independent software approach.

PubMed

Riffel, Johannes H; Keller, Marius G P; Aurich, Matthias; Sander, Yannick; Andre, Florian; Giusca, Sorin; Aus dem Siepen, Fabian; Seitz, Sebastian; Galuschky, Christian; Korosoglou, Grigorios; Mereles, Derliz; Katus, Hugo A; Buss, Sebastian J

2015-07-01

Myocardial deformation measurement is superior to left ventricular ejection fraction in identifying early changes in myocardial contractility and prediction of cardiovascular outcome. The lack of standardization hinders its clinical implementation. The aim of the study is to investigate a novel standardized deformation imaging approach based on the feature tracking algorithm for the assessment of global longitudinal (GLS) and global circumferential strain (GCS) in echocardiography and cardiac magnetic resonance imaging (CMR). 70 subjects undergoing CMR were consecutively investigated with echocardiography within a median time of 30 min. GLS and GCS were analyzed with a post-processing software incorporating the same standardized algorithm for both modalities. Global strain was defined as the relative shortening of the whole endocardial contour length and calculated according to the strain formula. Mean GLS values were -16.2 ± 5.3 and -17.3 ± 5.3 % for echocardiography and CMR, respectively. GLS did not differ significantly between the two imaging modalities, which showed strong correlation (r = 0.86), a small bias (-1.1 %) and narrow 95 % limits of agreement (LOA ± 5.4 %). Mean GCS values were -17.9 ± 6.3 and -24.4 ± 7.8 % for echocardiography and CMR, respectively. GCS was significantly underestimated by echocardiography (p < 0.001). A weaker correlation (r = 0.73), a higher bias (-6.5 %) and wider LOA (± 10.5 %) were observed for GCS. GLS showed a strong correlation (r = 0.92) when image quality was good, while correlation dropped to r = 0.82 with poor acoustic windows in echocardiography. GCS assessment revealed only a strong correlation (r = 0.87) when echocardiographic image quality was good. No significant differences for GLS between two different echocardiographic vendors could be detected. Quantitative assessment of GLS using a standardized software algorithm allows the direct comparison of values acquired irrespective of the imaging modality. GLS may, therefore, serve as a reliable parameter for the assessment of global left ventricular function in clinical routine besides standard evaluation of the ejection fraction.

Effect of sample stratification on dairy GWAS results

PubMed Central

2012-01-01

Background Artificial insemination and genetic selection are major factors contributing to population stratification in dairy cattle. In this study, we analyzed the effect of sample stratification and the effect of stratification correction on results of a dairy genome-wide association study (GWAS). Three methods for stratification correction were used: the efficient mixed-model association expedited (EMMAX) method accounting for correlation among all individuals, a generalized least squares (GLS) method based on half-sib intraclass correlation, and a principal component analysis (PCA) approach. Results Historical pedigree data revealed that the 1,654 contemporary cows in the GWAS were all related when traced through approximately 10–15 generations of ancestors. Genome and phenotype stratifications had a striking overlap with the half-sib structure. A large elite half-sib family of cows contributed to the detection of favorable alleles that had low frequencies in the general population and high frequencies in the elite cows and contributed to the detection of X chromosome effects. All three methods for stratification correction reduced the number of significant effects. EMMAX method had the most severe reduction in the number of significant effects, and the PCA method using 20 principal components and GLS had similar significance levels. Removal of the elite cows from the analysis without using stratification correction removed many effects that were also removed by the three methods for stratification correction, indicating that stratification correction could have removed some true effects due to the elite cows. SNP effects with good consensus between different methods and effect size distributions from USDA’s Holstein genomic evaluation included the DGAT1-NIBP region of BTA14 for production traits, a SNP 45kb upstream from PIGY on BTA6 and two SNPs in NIBP on BTA14 for protein percentage. However, most of these consensus effects had similar frequencies in the elite and average cows. Conclusions Genetic selection and extensive use of artificial insemination contributed to overlapped genome, pedigree and phenotype stratifications. The presence of an elite cluster of cows was related to the detection of rare favorable alleles that had high frequencies in the elite cluster and low frequencies in the remaining cows. Methods for stratification correction could have removed some true effects associated with genetic selection. PMID:23039970

Glutaminase-Deficient Mice Display Hippocampal Hypoactivity, Insensitivity to Pro-Psychotic Drugs and Potentiated Latent Inhibition: Relevance to Schizophrenia

PubMed Central

Gaisler-Salomon, Inna; Miller, Gretchen M; Chuhma, Nao; Lee, Sooyeon; Zhang, Hong; Ghoddoussi, Farhad; Lewandowski, Nicole; Fairhurst, Stephen; Wang, Yvonne; Conjard-Duplany, Agnès; Masson, Justine; Balsam, Peter; Hen, René; Arancio, Ottavio; Galloway, Matthew P; Moore, Holly M; Small, Scott A; Rayport, Stephen

2009-01-01

Dysregulated glutamatergic neurotransmission has been strongly implicated in the pathophysiology of schizophrenia (SCZ). Recently, presynaptic modulation of glutamate transmission has been shown to have therapeutic promise. We asked whether genetic knockdown of glutaminase (gene GLS1) to reduce glutamatergic transmission presynaptically by slowing the recycling of glutamine to glutamate, would produce a phenotype relevant to SCZ and its treatment. GLS1 heterozygous (GLS1 het) mice showed about a 50% global reduction in glutaminase activity, and a modest reduction in glutamate levels in brain regions relevant to SCZ pathophysiology, but displayed neither general behavioral abnormalities nor SCZ-associated phenotypes. Functional imaging, measuring regional cerebral blood volume, showed hippocampal hypometabolism mainly in the CA1 subregion and subiculum, the inverse of recent clinical imaging findings in prodromal and SCZ patients. GLS1 het mice were less sensitive to the behavioral stimulating effects of amphetamine, showed a reduction in amphetamine-induced striatal dopamine release and in ketamine-induced frontal cortical activation, suggesting that GLS1 het mice are resistant to the effects of these pro-psychotic challenges. Moreover, GLS1 het mice showed clozapine-like potentiation of latent inhibition, suggesting that reduction in glutaminase has antipsychotic-like properties. These observations provide further support for the pivotal role of altered glutamatergic synaptic transmission in the pathophysiology of SCZ, and suggest that presynaptic modulation of the glutamine–glutamate pathway through glutaminase inhibition may provide a new direction for the pharmacotherapy of SCZ. PMID:19516252

Glutaminase-deficient mice display hippocampal hypoactivity, insensitivity to pro-psychotic drugs and potentiated latent inhibition: relevance to schizophrenia.

PubMed

Gaisler-Salomon, Inna; Miller, Gretchen M; Chuhma, Nao; Lee, Sooyeon; Zhang, Hong; Ghoddoussi, Farhad; Lewandowski, Nicole; Fairhurst, Stephen; Wang, Yvonne; Conjard-Duplany, Agnès; Masson, Justine; Balsam, Peter; Hen, René; Arancio, Ottavio; Galloway, Matthew P; Moore, Holly M; Small, Scott A; Rayport, Stephen

2009-09-01

Dysregulated glutamatergic neurotransmission has been strongly implicated in the pathophysiology of schizophrenia (SCZ). Recently, presynaptic modulation of glutamate transmission has been shown to have therapeutic promise. We asked whether genetic knockdown of glutaminase (gene GLS1) to reduce glutamatergic transmission presynaptically by slowing the recycling of glutamine to glutamate, would produce a phenotype relevant to SCZ and its treatment. GLS1 heterozygous (GLS1 het) mice showed about a 50% global reduction in glutaminase activity, and a modest reduction in glutamate levels in brain regions relevant to SCZ pathophysiology, but displayed neither general behavioral abnormalities nor SCZ-associated phenotypes. Functional imaging, measuring regional cerebral blood volume, showed hippocampal hypometabolism mainly in the CA1 subregion and subiculum, the inverse of recent clinical imaging findings in prodromal and SCZ patients. GLS1 het mice were less sensitive to the behavioral stimulating effects of amphetamine, showed a reduction in amphetamine-induced striatal dopamine release and in ketamine-induced frontal cortical activation, suggesting that GLS1 het mice are resistant to the effects of these pro-psychotic challenges. Moreover, GLS1 het mice showed clozapine-like potentiation of latent inhibition, suggesting that reduction in glutaminase has antipsychotic-like properties. These observations provide further support for the pivotal role of altered glutamatergic synaptic transmission in the pathophysiology of SCZ, and suggest that presynaptic modulation of the glutamine-glutamate pathway through glutaminase inhibition may provide a new direction for the pharmacotherapy of SCZ.

Effective Data-Driven Calibration for a Galvanometric Laser Scanning System Using Binocular Stereo Vision.

PubMed

Tu, Junchao; Zhang, Liyan

2018-01-12

A new solution to the problem of galvanometric laser scanning (GLS) system calibration is presented. Under the machine learning framework, we build a single-hidden layer feedforward neural network (SLFN）to represent the GLS system, which takes the digital control signal at the drives of the GLS system as input and the space vector of the corresponding outgoing laser beam as output. The training data set is obtained with the aid of a moving mechanism and a binocular stereo system. The parameters of the SLFN are efficiently solved in a closed form by using extreme learning machine (ELM). By quantitatively analyzing the regression precision with respective to the number of hidden neurons in the SLFN, we demonstrate that the proper number of hidden neurons can be safely chosen from a broad interval to guarantee good generalization performance. Compared to the traditional model-driven calibration, the proposed calibration method does not need a complex modeling process and is more accurate and stable. As the output of the network is the space vectors of the outgoing laser beams, it costs much less training time and can provide a uniform solution to both laser projection and 3D-reconstruction, in contrast with the existing data-driven calibration method which only works for the laser triangulation problem. Calibration experiment, projection experiment and 3D reconstruction experiment are respectively conducted to test the proposed method, and good results are obtained.

Global longitudinal strain software upgrade: Implications for intervendor consistency and longitudinal imaging studies.

PubMed

Castel, Anne-Laure; Menet, Aymeric; Ennezat, Pierre-Vladimir; Delelis, François; Le Goffic, Caroline; Binda, Camille; Guerbaai, Raphaëlle-Ashley; Levy, Franck; Graux, Pierre; Tribouilloy, Christophe; Maréchaux, Sylvestre

2016-01-01

Speckle tracking can be used to measure left ventricular global longitudinal strain (GLS). To study the effect of speckle tracking software product upgrades on GLS values and intervendor consistency. Subjects (patients or healthy volunteers) underwent systematic echocardiography with equipment from Philips and GE, without a change in their position. Off-line post-processing for GLS assessment was performed with the former and most recent upgrades from these two vendors (Philips QLAB 9.0 and 10.2; GE EchoPAC 12.1 and 13.1.1). GLS was obtained in three myocardial layers with EchoPAC 13.1.1. Intersoftware and intervendor consistency was assessed. Interobserver variability was tested in a subset of patients. Among 73 subjects (65 patients and 8 healthy volunteers), absolute values of GLS were higher with QLAB 10.2 compared with 9.0 (intraclass correlation coefficient [ICC]: 0.88; bias: 2.2%). Agreement between EchoPAC 13.1.1 and 12.1 varied by myocardial layer (13.1.1 only): midwall (ICC: 0.95; bias: -1.1%), endocardium (ICC: 0.93; bias: 1.6%) and epicardial (ICC: 0.80; bias: -3.3%). Although GLS was comparable for QLAB 9.0 versus EchoPAC 12.1 (ICC: 0.95; bias: 0.5%), the agreement was lower between QLAB 10.2 and EchoPAC 13.1.1 endocardial (ICC: 0.91; bias: 1.1%), midwall (ICC: 0.73; bias: 3.9%) and epicardial (ICC: 0.54; bias: 6.0%). Interobserver variability of all software products in a subset of 20 patients was excellent (ICC: 0.97-0.99; bias: -0.8 to 1.0%). Upgrades of speckle tracking software may be associated with significant changes in GLS values, which could affect intersoftware and intervendor consistency. This finding has important clinical implications for the longitudinal follow-up of patients with speckle tracking echocardiography. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effects of increased left ventricular wall thickness on the myocardium in severe aortic stenosis with normal left ventricular ejection fraction: Two- and three-dimensional multilayer speckle tracking echocardiography.

PubMed

Cho, Eun Jeong; Park, Sung-Ji; Kim, Eun Kyoung; Lee, Ga Yeon; Chang, Sung-A; Choi, Jin-Oh; Lee, Sang-Chol; Park, Seung Woo

2017-04-01

The aim of this study was to determine the capability of real time three-dimensional echocardiography (RT3DE) and two-dimensional (2D) multilayer speckle tracking echocardiography (MSTE) for evaluation of early myocardial dysfunction triggered by increased left ventricular (LV) wall thickness in severe aortic stenosis (AS) with normal LV ejection fraction (EF≥55%). Conventional, RT3D STE and 2D MSTE were performed in 45 patients (mean 68.9±9.0 years) with severe AS (aortic valve area <1 cm 2 , aortic velocity Vmax >4 m/s or mean PG >40 mm Hg) and normal left ventricular ejection fraction (LVEF) without overt coronary artery disease and in 18 age-, sex-matched healthy controls. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS), and global radial strain (GRS) were calculated using RT3DE and MSTE. The severe AS group had lower 3D GLS, GRS, GAS and 2D epicardium, and mid-wall and endocardium GLS compared to healthy controls. In MSTE analysis, 2D LS and CS values decreased from the endocardial layer toward the epicardial layer. Severe AS patients with increased LV wall thickness had lower 3D GLS and 2D epicardium, and mid-wall and endocardium GLS compared with severe AS patients without LV wall thickening. GLS on RT3D STE was correlated with GLS on 2D MSTE, left ventricular mass index, LVEF, left atrial volume index, and lnNT-proBNP. RT3DE and 2D MSTE can be used to identify subtle contractile dysfunction triggered by increased LV wall thickness in severe AS with normal LVEF. Therefore, RT3D STE and 2D MSTE may provide additional information that can facilitate decision-making regarding severe AS patients with increased LV wall thickness and normal LV function. © 2017, Wiley Periodicals, Inc.

Conceptual study of Earth observation missions with a space-borne laser scanner

NASA Astrophysics Data System (ADS)

Kobayashi, Takashi; Sato, Yohei; Yamakawa, Shiro

2017-11-01

The Japan Aerospace Exploration Agency (JAXA) has started a conceptual study of earth observation missions with a space-borne laser scanner (GLS, as Global Laser Scanner). Laser scanners are systems which transmit intense pulsed laser light to the ground from an airplane or a satellite, receive the scattered light, and measure the distance to the surface from the round-trip delay time of the pulse. With scanning mechanisms, GLS can obtain high-accuracy three-dimensional (3D) information from all over the world. High-accuracy 3D information is quite useful in various areas. Currently, following applications are considered. 1. Observation of tree heights to estimate the biomass quantity. 2. Making the global elevation map with high resolution. 3. Observation of ice-sheets. This paper aims at reporting the present state of our conceptual study of the GLS. A prospective performance of the GLS for earth observation missions mentioned above.

Relationship of Office and Ambulatory Blood Pressure With Left Ventricular Global Longitudinal Strain.

PubMed

Sera, Fusako; Jin, Zhezhen; Russo, Cesare; Lee, Edward S; Schwartz, Joseph E; Rundek, Tatjana; Elkind, Mitchell S V; Homma, Shunichi; Sacco, Ralph L; Di Tullio, Marco R

2016-11-01

Left ventricular (LV) global longitudinal strain (GLS) is an early indicator of subclinical cardiac dysfunction, even when LV ejection fraction (LVEF) is normal, and is an independent predictor of cardiovascular events. Ambulatory blood pressure (BP) is a better predictor of cardiovascular events, including heart failure, than office BP. We investigated the association of office and ambulatory BP measurements with subclinical LV systolic dysfunction in a community-based cohort with normal LVEF. Two-dimensional speckle-tracking echocardiography and 24-hour ambulatory BP monitoring were performed in 577 participants (mean age 70±9 years; 60% women) with LVEF ≥50% from the Cardiovascular Abnormalities and Brain Lesions (CABL) study. Univariable and multivariable linear regression analyses were used to assess the associations of BP measures with GLS. Higher ambulatory and office BP values were consistently associated with impaired GLS. After adjustment for pertinent covariates (age, sex, race/ethnicity, body mass index, diabetes mellitus, coronary artery disease, LV mass index, and antihypertensive medication), office diastolic BP and ambulatory systolic and diastolic BPs (24-hour, daytime and nighttime) were independently associated with GLS (P = 0.003 for office DBP, P ≤ 0.001 for all ambulatory BPs). When ambulatory and office BP values were included in the same model, all ambulatory BP measures remained significantly associated with GLS (all P < 0.01), whereas office BP values were not. Ambulatory BP values are significantly associated with impaired GLS and the association is stronger than for office BP. Ambulatory BP monitoring might have a role in the risk stratification of hypertensive patients for early LV dysfunction.

Improvement in Strain Concordance between Two Major Vendors after the Strain Standardization Initiative.

PubMed

Yang, Hong; Marwick, Thomas H; Fukuda, Nobuaki; Oe, Hiroki; Saito, Makoto; Thomas, James D; Negishi, Kazuaki

2015-06-01

Disagreement of strain measurements among different vendors has provided an obstacle to the clinical use of strain. A joint standardization task force between professional societies and industry was initiated to reduce intervendor variability of strain. Although feedback from this process has been used in software upgrades, little is known about the effects of efforts to improve conformity. The aim of this study was to assess whether intervendor agreement for global longitudinal strain (GLS) has improved after standardization initiatives. Eighty-two subjects (mean age, 52 ± 21 years; 55% men) prospectively underwent two sequential examinations using two most common ultrasound systems (Vivid E9 and iE33). GLS was calculated using proprietary software (EchoPAC-PC BT12 [E12] and BT13 [E13] vs QLAB version 8.0 [Q8], QLAB version 9.0 [Q9], and QLAB version 10.0 [Q10]). Agreements in GLS were evaluated with Bland-Altman plots. Coefficients of variation (CVs) were compared using the Friedman test and compared with CVs of left ventricular volumes and ejection fraction (LVEF). Median GLS using E12 was -19.2% (interquartile range [IQR], -15.2% to -23.2%), compared with -19.3% (IQR, -14.9% to -23.7%) for E13, -15.7% (IQR, -11.4% to -20%) for Q8, -19% (IQR, -15.7% to -22.3%) for Q9, and -18.7% (IQR, -15.7% to -21.7%) for Q10. The CVs of prestandardization GLS (12 ± 8% [E12/Q8] and 14 ± 8 [E13/Q8]) were significantly larger than that of LVEF (5 ± 5) (P < .001). Since standardization, the CVs of GLS have shown improvement (6 ± 4 [E12/Q9], 7 ± 4 [E12/Q10], 6 ± 4 [E13/Q9], and 7 ± 4 [E13/Q10]) and are similar to those of LVEF. Subsequent to the joint standardization task force, there has been improvement in between-vendor concordance in GLS between two leading ultrasound manufactures, the variability of which is now analogous to that of LVEF. The removal of concerns about measurement variability should allow wider use of GLS. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

The Garrett Lee Smith Memorial Suicide Prevention Program

PubMed Central

Goldston, David B.; Walrath, Christine M.; McKeon, Richard; Puddy, Richard W.; Lubell, Keri M.; Potter, Lloyd B.; Rodi, Michael S.

2011-01-01

Responding to calls for greater efforts to reduce youth suicide, the Garrett Lee Smith (GLS) Memorial Act to date has provided funding for 68 state, territory, and tribal community grants, and 74 college campus grants for suicide prevention efforts. Suicide prevention activities supported by GLS grantees have included education, training programs including gatekeeper training, screening activities, infrastructure for improved linkages to services, crisis hotlines, and community partnerships. Through participation in both local- and cross-site evaluations, GLS grantees are generating data regarding the local context, proximal outcomes, and implementation of programs, as well as opportunities for improvement of suicide prevention efforts. PMID:20560746

The Garrett Lee Smith memorial suicide prevention program.

PubMed

Goldston, David B; Walrath, Christine M; McKeon, Richard; Puddy, Richard W; Lubell, Keri M; Potter, Lloyd B; Rodi, Michael S

2010-06-01

In response to calls for greater efforts to reduce youth suicide, the Garrett Lee Smith (GLS) Memorial Act has provided funding for 68 state, territory, and tribal community grants, and 74 college campus grants for suicide prevention efforts. Suicide prevention activities supported by GLS grantees have included education, training programs (including gatekeeper training), screening activities, infrastructure for improved linkages to services, crisis hotlines, and community partnerships. Through participation in both local- and cross-site evaluations, GLS grantees are generating data regarding the local context, proximal outcomes, and implementation of programs, as well as opportunities for improvement of suicide prevention efforts.

Identifying model error in metabolic flux analysis - a generalized least squares approach.

PubMed

Sokolenko, Stanislav; Quattrociocchi, Marco; Aucoin, Marc G

2016-09-13

The estimation of intracellular flux through traditional metabolic flux analysis (MFA) using an overdetermined system of equations is a well established practice in metabolic engineering. Despite the continued evolution of the methodology since its introduction, there has been little focus on validation and identification of poor model fit outside of identifying "gross measurement error". The growing complexity of metabolic models, which are increasingly generated from genome-level data, has necessitated robust validation that can directly assess model fit. In this work, MFA calculation is framed as a generalized least squares (GLS) problem, highlighting the applicability of the common t-test for model validation. To differentiate between measurement and model error, we simulate ideal flux profiles directly from the model, perturb them with estimated measurement error, and compare their validation to real data. Application of this strategy to an established Chinese Hamster Ovary (CHO) cell model shows how fluxes validated by traditional means may be largely non-significant due to a lack of model fit. With further simulation, we explore how t-test significance relates to calculation error and show that fluxes found to be non-significant have 2-4 fold larger error (if measurement uncertainty is in the 5-10 % range). The proposed validation method goes beyond traditional detection of "gross measurement error" to identify lack of fit between model and data. Although the focus of this work is on t-test validation and traditional MFA, the presented framework is readily applicable to other regression analysis methods and MFA formulations.

Analysis of the extracts of Isatis tinctoria by new analytical approaches of HPLC, MS and NMR.

PubMed

Zhou, Jue; Qu, Fan

2011-01-01

The methods of extraction, separation and analysis of alkaloids and indole glucosinolates (GLs) ofIsatis tinctoria were reviewed. Different analytical approaches such as High-pressure Liquid Chromatography (HPLC), Liquid Chromatography with Electrospray Ionization Mass Spectrometry (LC/ESI/MS), Electrospray Ionization Time-Of-Flight Mass Spectrometry (ESI-TOF-MS), and Nuclear Magnetic Resonance (NMR) were used to validate and identity of these constituents. These methods provide rapid separation, identification and quantitative measurements of alkaloids and GLs of Isatis tinctoria. By connection with different detectors to HPLC such as PDA, ELSD, ESI- and APCI-MS in positive and negative ion modes, complicated compounds could be detected with at least two independent detection modes. The molecular formula can be derived in a second step of ESI-TOF-MS data. But for some constituents, UV and MS cannot provide sufficient structure identification. After peak purification, NMR by semi-preparative HPLC can be used as a complementary method.

Enteric methane production and ruminal fermentation of forage brassica diets fed in continuous culture.

PubMed

Dillard, Sandra Leanne; Roca-Fernández, Ana I; Rubano, Melissa D; Elkin, Kyle R; Soder, Kathy J

2018-04-14

The aim of the current study was to determine nutrient digestibility, VFA production, N metabolism, and CH4 production of canola (Brassica napus L.), rapeseed (B. napus L.), turnip (Brassica rapa L.), and annual ryegrass (Lolium multiflorum Lam.) fed with orchardgrass (Dactylis glomerata L.) in continuous culture. Diets were randomly assigned to fermentors in a 4 × 4 Latin square design using 7 d for adaptation and 3 d for collection. Diets were: 1) 50% orchardgrass + 50% annual ryegrass (ARG); 2) 50% orchardgrass + 50% canola (CAN); 3) 50% orchardgrass + 50% rapeseed (RAP); and 4) 50% orchardgrass + 50% turnip (TUR). Feedings (82 g DM/d) occurred four times daily throughout 4, 10-d periods at 730, 1030, 1400, and 1900 h. Methane samples were collected every 10 min using a photoacoustic gas analyzer (LumaSense Technologies, Inc.; Santa Clara, CA) during the last 3 d of the experiment. Effluent samples were collected on d 8, 9, and 10, composited by fermentor, and analyzed for VFA and pH as well as DM, OM, CP, and fiber fractions for determination of nutrient digestibility. Forage samples were analyzed for CP, NDF, ADF, minerals, and glucosinolate (GLS) concentrations. Data were analyzed using the GLIMMIX procedure of SAS. Apparent DM, OM, and NDF digestibilities and true DM and OM digestibilities were similar (P > 0.28) among diets (45.1, 63.2, 44.1, 67.1, and 87.2%, respectively). Total VFA (87.2 mol/100 mol), pH (6.47), and acetate (A: 44.6 mol/100 mol) were also not different (P > 0.20) among diets. The A:P (P = propionate) ratio was greater (P < 0.01) in ARG and CAN than RAP and TUR. Daily CH4 production was greater (P < 0.01) in ARG than all other diets (68.9 vs. 11.2 mg/d). Methane, whether expressed as g per g of OM, NDF, digestible OM, or digestible NDF fed was greatest (P < 0.01) in ARG but similar (P > 0.18) among brassica diets. A significant negative correlation was observed between total GLS and CH4 production. However, when multiple regression analysis on CH4 production was completed, neither total GLS nor individual GLS were a significant component of the model. Addition of brassicas provided similar nutrient digestibility to ARG while reducing daily CH4 production, potentially making brassicas an alternative for ARG in pasture-based ruminant diets.

Normal myocardial strain values using 2D speckle tracking echocardiography in healthy adults aged 20 to 72 years.

PubMed

Menting, Myrthe E; McGhie, Jackie S; Koopman, Laurens P; Vletter, Wim B; Helbing, Willem A; van den Bosch, Annemien E; Roos-Hesselink, Jolien W

2016-11-01

Evaluation of left ventricular (LV) myocardial deformation by speckle tracking echocardiography (STE) is useful for clinical and research purposes. However, strain measurements depend on the used software. Normative data for QLAB 10 (Philips) are scarce. Additionally, little is known about the influence of anthropometric factors. We aimed to establish normal adult STE-derived strain and strain rate values and to evaluate associations with anthropometrics. One hundred fifty-five healthy subjects aged 20 to 72 years (≥28 subjects per decile) were prospectively gathered and examined with electrocardiography and two-dimensional echocardiography. With STE, we assessed peak systolic LV global longitudinal strain (GLS), segmental longitudinal strain, and strain rate from the three standard apical views. We included 147 healthy subjects (age 44.6±13.7 years, 50% female, GLS -20.8±2.0%). Men had significantly lower GLS than women (-20.1±1.8% vs -21.5±2.0%, P<.001). GLS was significantly lower in subjects with age above 55 years (P=.029), higher blood pressure (P<.001), higher body surface area (BSA, P<.001), larger LV end-systolic and end-diastolic volumes (both P<.001), lower LV ejection fraction (P<.001), and some indices of diastolic function. After multivariable regression analysis, the correlation with systolic blood pressure, E-wave, and LV end-systolic volume remained significant. The systolic strain rates of most segments correlated with BSA. Our study resulted in normative LV GLS values assessed with QLAB 10. Male sex, higher BSA, and higher blood pressure negatively influence GLS. Therefore, these factors should be taken into account for strain interpretation in clinical practice. © 2016, Wiley Periodicals, Inc.

A morpho-functional study using PEP/LVET ratio and global longitudinal strain in patients with dilated cardiomyopathy.

PubMed

Corîci, Oana Maria; Tănasie, Cornelia Andreea; Alexandru, Dragoş Ovidiu; Florescu, Mihaela Corina; Comănescu, Maria Victoria; Kamal, Kamal Constantin; Ţenea-Cojan, Tiberiu Ştefăniţă; Iancău, Maria; Dinescu, Sorin Nicolae

2018-01-01

To assess left ventricular (LV) systolic function and morphology in patients with severe dilated cardiomyopathy (DCM), using both conventional and a complex technique, speckle-tracking echocardiography, and evaluate the correlation between pre-ejection period and left ventricular ejection period (PEP/LVET) ratio, global longitudinal strain (GLS), and severity of the condition. Seventeen patients were enrolled after rigorous criteria. Echocardiography was performed in conventional and speckle-tracking mode, in all patients with DCM, in sinus rhythm. LV dimensions, volumes and ejection fraction (LVEF) were measured. PEP/LVET ratio was obtained from apical 5-chamber axis and was defined as the time between QRS onset and LV ejection reported to LV ejection period. Speckle-tracking imaging was performed in offline mode and GLS was obtained from parasternal 4-, 3-, 2-chamber apical view, by averaging longitudinal peak systolic strain of all 17 LV-segments. New York Heart Association (NYHA) functional class correlated significantly with LVEF (-0.82; p=0.0006), PEP/LVET (0.86; p=0.001) or GLS (0.85; p=0.0002). Considerable correlations were between mitral regurgitation (MR) severity and LVEF (-0.65; p=0.01) or PEP/LVET (0.69; p=0.0059), but higher were between MR severity and GLS (0.76; p=0.0018). Tricuspid regurgitation (TR) grading correlated statistically with LVEF (-0.62; p=0.01), PEP/LVET and GLS (0.6; p=0.018; and 0.62; p=0.014, respectively). As opposed to the parameters in conventional echocardiography, GLS correlated with DCM etiology (p=0.0046) and with the gender (p=0.048). This study demonstrates that, in patients with DCM, assessment of cardiac dyssynchrony can be accurately accomplished by combining parameters in conventional and in speckle-tracking echocardiography.

Global longitudinal strain and long-term outcomes in asymptomatic extracardiac sarcoid patients with no apparent cardiovascular disease.

PubMed

Felekos, Ioannis; Aggeli, Constantina; Gialafos, Elias; Kouranos, Vasileios; Rapti, Aggeliki; Sfikakis, Petros; Koulouris, Nikolaos; Tousoulis, Dimitris

2018-06-01

Global longitudinal strain (GLS) is increasingly accepted as a predictor of mortality in various clinical settings. This study tested the hypothesis that GLS is associated with increased event rate in patients with extracardiac sarcoidosis, who have no overt symptoms of cardiovascular disease and preserved ejection fraction (EF). We retrospectively studied 117 patients with extracardiac sarcoidosis and 45 age- and sex-matched controls, who underwent comprehensive echocardiographic study, while GLS was measured by an offline speckle tracking algorithm. Patients who had signs and symptoms of cardiovascular disease at the time of the examination were excluded from the study. Patients were followed for an average of 57.1 months. Primary endpoint was defined as a composite endpoint of heart failure-related hospitalizations, need for device therapy, arrhythmias, and all-cause mortality. The age of patients was 42 ± 6 years old (43 men). Events were recorded in 10 patients (8.5%). Tissue Doppler revealed E/Em 7.9 ± 3.5, while EF was 54.2 ± 3.5%. Global longitudinal strain was 14.4 ± 3%, and a cutoff value ≤-13.6% for GLS was considered more associated with adverse outcomes (AUC 0.84). After adjustment for multiple potential confounders (age, gender, hypertension, diabetes, E/Em, and EF), GLS remained strongly associated with adverse outcomes (HR 0.8, 0.63 to 0.98 95% C.I, P = .04). In conclusion, among patients with extracardiac sarcoidosis and no symptoms of cardiovascular disease, even when EF is preserved, GLS seems to be strongly associated with adverse future events. © 2018 Wiley Periodicals, Inc.

Glutamine drives glutathione synthesis and contributes to radiation sensitivity of A549 and H460 lung cancer cell lines

PubMed Central

Sappington, Daniel R.; Siegel, Eric R.; Hiatt, Gloria; Desai, Abhishek; Penney, Rosalind B.; Jamshidi-Parsian, Azemat; Griffin, Robert J.; Boysen, Gunnar

2016-01-01

Background Increased glutamine uptake is known to drive cancer cell proliferation, making tumor cells glutamine-dependent. Glutamine provides additional carbon and nitrogen sources for cell growth. The first step in glutamine utilization is its conversion to glutamate by glutaminase (GLS). Glutamate is a precursor for glutathione synthesis, and we investigated the hypothesis that glutamine drives glutathione synthesis and thereby contributes to cellular defense systems. Methods The importance of glutamine for glutathione synthesis was studied in H460 and A549 lung cancer cell lines using glutamine-free medium and Bis-2-(5-phenyl-acetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES) a GLS inhibitor. Metabolic activities were determined by targeted mass spectrometry. Results A significant correlation between glutamine consumption and glutathione excretion was demonstrated in H460 and A549 tumor cells. Culturing in the presence of [13C5]glutamine demonstrated that by 12 hrs >50% of excreted glutathione is derived from glutamine. Culturing in glutamine-free medium or treatment with BPTES, a glutaminase (GLS)-specific inhibitor, reduced cell proliferation and viability, and abolished glutathione excretion. Treatment with glutathione-ester prevented BPTES induced cytotoxicity. Inhibition of GLS markedly radiosensitized the lung tumor cell lines, suggesting an important role of glutamine-derived glutathione in determining radiation sensitivity. Conclusions We demonstrate here for the first time that a significant amount of extracellular glutathione is directly derived from glutamine. This finding adds yet another important function to the already known glutamine dependence of tumor cells and probably tumors as well. General significance Glutamine is essential for synthesis and excretion of glutathione to promote cell growth and viability. PMID:26825773

Enhanced Right-Chamber Remodeling in Endurance Ultra-Trail Athletes Compared to Marathon Runners Detected by Standard and Speckle-Tracking Echocardiography

PubMed Central

Ujka, Kristian; Bastiani, Luca; D'Angelo, Gennaro; Catuzzo, Bruna; Tonacci, Alessandro; Mrakic-Sposta, Simona; Vezzoli, Alessandra; Giardini, Guido; Pratali, Lorenza

2017-01-01

Background: Strenuous and endurance exercise training have been associated with morphological and functional heart remodeling. Two-dimensional speckle-tracking echocardiography (STE) is a novel technique that allows an accurate quantification of global myocardium deformation. Our aim was to evaluate together left and right cardiac remodeling in different long-distance running athletes: marathon runners (42 km) (M) and endurance mountain runners (>300 Km) (UT). Methods: A total of 92 athletes (70 males, 76%) including 47 M [age 45 ± 7 years; training: 18 (9–53) years*days/week], 45 UT [age 42 ± 9, training: 30 (15–66) years*days/week] underwent conventional echocardiography and STE (Beyond Diogenes 2.0, AMID) during the agonistic season. Results: Right ventricle (RV) end-diastolic area (p = 0.026), fractional area changing (FAC) (p = 0.008) and RV global longitudinal strain (GLS) were significantly increasedin UT athletes. Furthermore, UT showed larger right atrium (RA) volume (p = 0.03), reduced RA GLS and significantly increased RA global circumferential strain (GCS) compared to M. After adjustment for age, sex, and HR as covariates, UT showed a reduced RA GLS (OR 0.907; CI 0.856–0.961) and increased RV FAC (OR 1.172; CI: 1.044–1.317) compared to M. Conclusion: Athletes enrolled in UT endurance activities showed RV and RA morphological and functional remodeling to increased preload in comparison with M runners characterized by increased RV FAC and reduced RA GLS. Follow-up studies are needed to better assess the long-term clinical impact of these modifications. 2D STE is a useful tool for investigating the deformation dynamic in different sports specialties. PMID:28790928

Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006

USGS Publications Warehouse

Parrett, Charles; Veilleux, Andrea; Stedinger, J.R.; Barth, N.A.; Knifong, Donna L.; Ferris, J.C.

2011-01-01

Improved flood-frequency information is important throughout California in general and in the Sacramento-San Joaquin River Basin in particular, because of an extensive network of flood-control levees and the risk of catastrophic flooding. A key first step in updating flood-frequency information is determining regional skew. A Bayesian generalized least squares (GLS) regression method was used to derive a regional-skew model based on annual peak-discharge data for 158 long-term (30 or more years of record) stations throughout most of California. The desert areas in southeastern California had too few long-term stations to reliably determine regional skew for that hydrologically distinct region; therefore, the desert areas were excluded from the regional skew analysis for California. Of the 158 long-term stations used to determine regional skew, 145 have minimally regulated annual-peak discharges, and 13 stations are dam sites for which unregulated peak discharges were estimated from unregulated daily maximum discharge data furnished by the U.S. Army Corp of Engineers. Station skew was determined by using an expected moments algorithm (EMA) program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual peak-discharge data. The Bayesian GLS regression method previously developed was modified because of the large cross correlations among concurrent recorded peak discharges in California and the use of censored data and historical flood information with the new expected moments algorithm. In particular, to properly account for these cross-correlation problems and develop a suitable regression model and regression diagnostics, a combination of Bayesian weighted least squares and generalized least squares regression was adopted. This new methodology identified a nonlinear function relating regional skew to mean basin elevation. The regional skew values ranged from -0.62 for a mean basin elevation of zero to 0.61 for a mean basin elevation of 11,000 feet. This relation between skew and elevation reflects the interaction of snow with rain, which increases with increased elevation. The equivalent record length for the new regional skew ranges from 52 to 65 years of record, depending upon mean basin elevation. The old regional skew map in Bulletin 17B, published by the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data (1982), reported an equivalent record length of only 17 years. The newly developed regional skew relation for California was used to update flood frequency for the 158 sites used in the regional skew analysis as well as 206 selected sites in the Sacramento-San Joaquin River Basin. For these sites, annual-peak discharges having recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years were determined on the basis of data through water year 2006. The expected moments algorithm was used for determining the magnitude and frequency of floods at gaged sites by using regional skew values and using the basic approach outlined in Bulletin

Expression of the glutamine metabolism-related proteins glutaminase 1 and glutamate dehydrogenase in canine mammary tumours.

PubMed

Ryu, J-E; Park, H-K; Choi, H-J; Lee, H-B; Lee, H-J; Lee, H; Yu, E-S; Son, W-C

2018-06-01

Glutamine metabolism is an important metabolic pathway for cancer cell survival, and there is a critical connection between tumour growth and glutamine metabolism. Because of their similarities, canine mammary carcinomas are useful for studying human breast cancer. Accordingly, we investigated the correlations between the expression of glutamine metabolism-related proteins and the pathological features of canine mammary tumours. We performed immunohistochemical and western blot analysis of 39 mammary tumour tissues. In immunohistochemical analysis, the expression of glutaminase 1 (GLS1) in the epithelial region increased according to the histological grade (P < .005). In the stromal region, complex-type tumours displayed significantly higher GLS1 intensity than simple-type tumours. However, glutamate dehydrogenase expression did not show the same tendencies as GLS1. The western blot results were consistent with the immunohistochemical findings. These results suggest that the expression of GLS1 is correlates with clinicopathological factors in canine mammary tumours and shows a similar pattern to human breast cancer. © 2017 John Wiley & Sons Ltd.

β-Glucan Synthase Gene Overexpression and β-Glucans Overproduction in Pleurotus ostreatus Using Promoter Swapping

PubMed Central

Liu, Dongren; Qi, Yuancheng; Gao, Yuqian; Shen, Jinwen; Qiu, Liyou

2013-01-01

Mushroom β-glucans are potent immunological stimulators in medicine, but their productivities are very low. In this study, we successfully improved its production by promoter engineering in Pleurotus ostreatus. The promoter for β-1,3-glucan synthase gene (GLS) was replaced by the promoter of glyceraldehyde-3-phosphate dehydrogenase gene of Aspergillus nidulans. The homologous recombination fragment for swapping GLS promoter comprised five segments, which were fused by two rounds of combined touchdown PCR and overlap extension PCR (TD-OE PCR), and was introduced into P. ostreatus through PEG/CaCl2-mediated protoplast transformation. The transformants exhibited one to three fold higher transcription of GLS gene and produced 32% to 131% higher yield of β-glucans than the wild type. The polysaccharide yields had a significant positive correlation to the GLS gene expression. The infrared spectra of the polysaccharides all displayed the typical absorption peaks of β-glucans. This is the first report of successful swapping of promoters in filamentous fungi. PMID:23637884

The Garrett Lee Smith Memorial Suicide Prevention Program

ERIC Educational Resources Information Center

Goldston, David B.; Walrath, Christine M.; McKeon, Richard; Puddy, Richard W.; Lubell, Keri M.; Potter, Lloyd B.; Rodi, Michael S.

2010-01-01

In response to calls for greater efforts to reduce youth suicide, the Garrett Lee Smith (GLS) Memorial Act has provided funding for 68 state, territory, and tribal community grants, and 74 college campus grants for suicide prevention efforts. Suicide prevention activities supported by GLS grantees have included education, training programs…

A Two-Stage Algorithm for Origin-Destination Matrices Estimation Considering Dynamic Dispersion Parameter for Route Choice

PubMed Central

Wang, Yong; Ma, Xiaolei; Liu, Yong; Gong, Ke; Henricakson, Kristian C.; Xu, Maozeng; Wang, Yinhai

2016-01-01

This paper proposes a two-stage algorithm to simultaneously estimate origin-destination (OD) matrix, link choice proportion, and dispersion parameter using partial traffic counts in a congested network. A non-linear optimization model is developed which incorporates a dynamic dispersion parameter, followed by a two-stage algorithm in which Generalized Least Squares (GLS) estimation and a Stochastic User Equilibrium (SUE) assignment model are iteratively applied until the convergence is reached. To evaluate the performance of the algorithm, the proposed approach is implemented in a hypothetical network using input data with high error, and tested under a range of variation coefficients. The root mean squared error (RMSE) of the estimated OD demand and link flows are used to evaluate the model estimation results. The results indicate that the estimated dispersion parameter theta is insensitive to the choice of variation coefficients. The proposed approach is shown to outperform two established OD estimation methods and produce parameter estimates that are close to the ground truth. In addition, the proposed approach is applied to an empirical network in Seattle, WA to validate the robustness and practicality of this methodology. In summary, this study proposes and evaluates an innovative computational approach to accurately estimate OD matrices using link-level traffic flow data, and provides useful insight for optimal parameter selection in modeling travelers’ route choice behavior. PMID:26761209

Reduction of total glucosinolates in canola meal via thermal treatment and fungal bioprocessing

USDA-ARS?s Scientific Manuscript database

On a worldwide basis, canola (Brassica napus) meal is second only to soybean meal as a protein source for livestock. A general limitation of Brassica spp. meals is the presence of glucosinolates (GLS). GLS and the enzyme myrosinase are compartmentally stored separately in the plant. Upon disruption ...

Clustering of unhealthy outdoor advertisements around child-serving institutions: a comparison of three cities.

PubMed

Hillier, Amy; Cole, Brian L; Smith, Tony E; Yancey, Antronette K; Williams, Jerome D; Grier, Sonya A; McCarthy, William J

2009-12-01

Using GPS devices and digital cameras, we surveyed outdoor advertisements in Austin, Los Angeles and Philadelphia. GIS and hot spot analysis revealed that unhealthy ads were clustered around child-serving institutions in Los Angeles and Philadelphia but not in Austin. Multivariate generalized least square (GLS) regression models showed that percent black (p<0.04) was a significant positive predictor of clustering in Philadelphia and percent white (p<0.06) was a marginally significant negative predictor of clustering in Los Angeles after controlling for several land use variables. The results emphasize the importance of zoning and land use regulations to protect children from exposure to unhealthy commercial messages, particularly in neighborhoods with significant racial/ethnic minority populations.

LC-MS profiling of glucosinolates in the seeds of Brassica elongata Ehrh., and of the two stenoendemic B. botteri Vis and B. cazzae Ginzb. & Teyber.

PubMed

Montaut, Sabine; Blažević, Ivica; Ruščić, Mirko; Rollin, Patrick

2017-01-01

The glucosinolates (GLs) present in seed extracts of Brassica elongata Ehrh., B. botteri Vis and B. cazzae Ginzb. & Teyber from Croatia were identified by LC-MS. 4-Hydroxyindol-3-ylmethyl GL (3) was the major GL in the seeds of B. elongata, along with the four minor GLs 2-(R)-hydroxy-3-butenyl- (1), 3-butenyl- (2), 4-pentenyl- (4) and indol-3-ylmethyl (5). The seeds of B. botteri (Vis island) and B. cazzae (Sušac island) contained 2 as the major GL as well as 1, 3, 5 and 4-methoxyindol-3-ylmethyl GL (6). However, the GLs in B. botteri (Palagruža island) differed from other varieties having 2-propenyl GL (7) as the major GL in the seeds, and the four minor GLs 2, 3, 5 and 6. This first report of the GL content in the seeds of B. elongata, B. botteri and B. cazzae indicates that the unique GL profiles could be specific to the geographical origin of the plant.

Lipidomic Approaches towards Deciphering Glycolipids from Microalgae as a Reservoir of Bioactive Lipids

PubMed Central

da Costa, Elisabete; Silva, Joana; Mendonça, Sofia Hoffman; Abreu, Maria Helena; Domingues, Maria Rosário

2016-01-01

In recent years, noteworthy research has been performed around lipids from microalgae. Among lipids, glycolipids (GLs) are quite abundant in microalgae and are considered an important source of fatty acids (FAs). GLs are rich in 16- and 18-carbon saturated and unsaturated fatty acids and often contain polyunsaturated fatty acids (PUFAs) like n-3 α-linolenic (ALA 18:3), eicosapentaenoic (EPA, 20:5) and docosahexaenoic (DHA, 22:6). GLs comprise three major classes: monogalactosyldiacyl glycerolipids (MGDGs), digalactosyl diacylglycerolipids (DGDGs) and sulfoquinovosyl diacylglycerolipids (SQDGs), whose composition in FA directly depends on the growth conditions. Some of these lipids are high value-added compounds with antitumoral, antimicrobial and anti-inflammatory activities and also with important nutritional significance. To fully explore GLs’ bioactive properties it is necessary to fully characterize their structure and to understand the relation between the structure and their biological properties, which can be addressed using modern mass spectrometry (MS)-based lipidomic approaches. This review will focus on the up-to-date FA composition of GLs identified by MS-based lipidomics and their potential as phytochemicals. PMID:27213410

Dopamine neuron dependent behaviors mediated by glutamate cotransmission

PubMed Central

Mingote, Susana; Chuhma, Nao; Kalmbach, Abigail; Thomsen, Gretchen M; Wang, Yvonne; Mihali, Andra; Sferrazza, Caroline; Zucker-Scharff, Ilana; Siena, Anna-Claire; Welch, Martha G; Lizardi-Ortiz, José; Sulzer, David; Moore, Holly; Gaisler-Salomon, Inna; Rayport, Stephen

2017-01-01

Dopamine neurons in the ventral tegmental area use glutamate as a cotransmitter. To elucidate the behavioral role of the cotransmission, we targeted the glutamate-recycling enzyme glutaminase (gene Gls1). In mice with a dopamine transporter (Slc6a3)-driven conditional heterozygous (cHET) reduction of Gls1 in their dopamine neurons, dopamine neuron survival and transmission were unaffected, while glutamate cotransmission at phasic firing frequencies was reduced, enabling a selective focus on the cotransmission. The mice showed normal emotional and motor behaviors, and an unaffected response to acute amphetamine. Strikingly, amphetamine sensitization was reduced and latent inhibition potentiated. These behavioral effects, also seen in global GLS1 HETs with a schizophrenia resilience phenotype, were not seen in mice with an Emx1-driven forebrain reduction affecting most brain glutamatergic neurons. Thus, a reduction in dopamine neuron glutamate cotransmission appears to mediate significant components of the GLS1 HET schizophrenia resilience phenotype, and glutamate cotransmission appears to be important in attribution of motivational salience. DOI: http://dx.doi.org/10.7554/eLife.27566.001 PMID:28703706

Glutaminolysis and carcinogenesis of oral squamous cell carcinoma.

PubMed

Cetindis, Marcel; Biegner, Thorsten; Munz, Adelheid; Teriete, Peter; Reinert, Siegmar; Grimm, Martin

2016-02-01

Glutaminolysis is a crucial factor for tumor metabolism in the carcinogenesis of several tumors but has not been clarified for oral squamous cell carcinoma (OSCC) yet. Expression of glutaminolysis-related solute carrier family 1, member 5 (SLC1A5)/neutral amino acid transporter (ASCT2), glutaminase (GLS), and glutamate dehydrogenase (GLDH) was analyzed in normal oral mucosa (n = 5), oral precursor lesions (simple hyperplasia, n = 11; squamous intraepithelial neoplasia, SIN I-III, n = 35), and OSCC specimen (n = 42) by immunohistochemistry. SLC1A5/ASCT2 and GLS were significantly overexpressed in the carcinogenesis of OSCC compared with normal tissue, while GLDH was weakly detected. Compared with SIN I-III SLC1A5/ASCT2 and GLS expression were significantly increased in OSCC. GLDH expression did not significantly differ from SIN I-III compared with OSCC. This study shows the first evidence of glutaminolysis-related SLC1A5/ASCT2, GLS, and GLDH expression in OSCC. The very weak GLDH expression indicates that glutamine metabolism is rather related to nucleotide or protein/hexosamine biosynthesis or to the function as an antioxidant (glutathione) than to energy production or generation of lactate through entering the tricarboxylic acid cycle. Overcoming glutaminolysis by targeting c-Myc oncogene (e.g. by natural compounds) and thereby cross-activation of mammalian target of rapamycin complex 1 or SLC1A5/ASCT2, GLS inhibitors may be a useful strategy to sensitize cancer cells to common OSCC cancer therapies.

Association Between Global Longitudinal Strain and Cardiovascular Events in Patients With Left Bundle Branch Block Assessed Using Two-Dimensional Speckle-Tracking Echocardiography.

PubMed

Hwang, In-Chang; Cho, Goo-Yeong; Yoon, Yeonyee E; Park, Jin Joo

2018-01-01

The prognostic value of left ventricular (LV) global strain and twist in patients with left bundle branch block (LBBB) is not fully investigated. The aim of this study was to investigate the association between myocardial strain and twist and cardiovascular events in patients with LBBB, as assessed using two-dimensional speckle-tracking echocardiography. A total of 269 patients with LBBB (mean age, 69.5 ± 10.9 years; 46.8% men) were retrospectively identified. Using speckle-tracking, LV global longitudinal strain (GLS), global circumferential strain, and twist were measured. Association between LV global function and a composite of cardiovascular mortality and hospitalization for heart failure was compared with clinical risk factors, LV ejection fraction (LVEF), and other echocardiographic parameters. During a median of 27.5 months (interquartile range, 12.8-43.9 months), the composite end point occurred in 55 patients (20.4%). In univariate analyses, diabetes mellitus, chronic kidney disease, ischemic etiology of LBBB, dilated left atrium, reduced LVEF, dilated left ventricle, and impaired LV global strain (GLS > -12.2%, global circumferential strain > -11.8%, and twist < 6.5°) showed associations with the composite end point. In multivariate analyses, GLS was significantly associated with the composite end point (adjusted hazard ratio, 4.697; 95% CI, 1.344-16.413; P = .015), whereas global circumferential strain, twist, and LVEF were not. GLS showed an additive association with poor prognosis over clinical risk factors and other echocardiographic parameters, including LVEF. Patients with preserved LVEFs (≥40%) but impaired GLS (>-12.2%) had a larger number of clinical events than those with impaired LVEFs but preserved GLS. Among patients with LBBB, GLS can provide better risk stratification than LVEF or other echocardiographic parameters. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Longitudinal left ventricular function for prediction of survival in systemic light-chain amyloidosis: incremental value compared with clinical and biochemical markers.

PubMed

Buss, Sebastian J; Emami, Mostafa; Mereles, Derliz; Korosoglou, Grigorios; Kristen, Arnt V; Voss, Andreas; Schellberg, Dieter; Zugck, Christian; Galuschky, Christian; Giannitsis, Evangelos; Hegenbart, Ute; Ho, Anthony D; Katus, Hugo A; Schonland, Stefan O; Hardt, Stefan E

2012-09-18

The aim of the study was to determine whether longitudinal left ventricular (LV) function provides prognostic information in a large cohort of patients with systemic light-chain (AL) amyloidosis. AL amyloidosis is associated with a high incidence of cardiovascular events. Reduced myocardial longitudinal function is one of the hallmarks of myocardial involvement in this rare disease. Two hundred six consecutive patients with biopsy-proven AL amyloidosis were investigated in this prospective observational study. Echocardiographic imaging parameters, mean tissue Doppler-derived longitudinal strain (LS), and two-dimensional global longitudinal strain (2D-GLS) of the LV, cardiac serological biomarkers, and comprehensive clinical disease characteristics were assessed. The primary endpoint was all-cause mortality or heart transplantation. After a median follow-up of 1207 days, LS and 2D-GLS were significant predictors of survival in AL amyloidosis. The cutoff values discriminating survivors from nonsurvivors were -10.65% for LS and -11.78% for 2D-GLS. In a multivariable echocardiographic Cox model, only diastolic dysfunction and 2D-GLS remained as independent predictors of survival. In comprehensive clinical models, 2D-GLS (p < 0.0001), diastolic dysfunction (p < 0.01), the pathologic free light chains (p < 0.05), cardiac troponin-T (cTnT) (p < 0.01), and the Karnofsky index (p < 0.001) remained as independent predictors. 2D-GLS delineated a superior prognostic value compared with that derived from pathologic free light chains or cTnT in patients evaluated before firstline chemotherapy (n = 113; p < 0.0001), and remained the only independent predictor besides the Karnofsky index in subjects with preserved LV ejection fraction (≥50%; n = 127; p < 0.01). LS and 2D-GLS both offered significant incremental information (p < 0.001) for the assessment of outcome compared with clinical variables (age, Karnofsky index, and New York Heart Association functional class) and serological biomarkers. In the largest serial investigation reported so far, reduced LV longitudinal function served as an independent predictor of survival in AL amyloidosis and offered incremental information beyond standard clinical and serological parameters. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Subclinical Cardiac Dysfunction Detected by Strain Imaging During Breast Irradiation With Persistent Changes 6 Weeks After Treatment

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

Lo, Queenie; Liverpool Hospital, Sydney, NSW; Hee, Leia

Purpose: To evaluate 2-dimensional strain imaging (SI) for the detection of subclinical myocardial dysfunction during and after radiation therapy (RT). Methods and Materials: Forty women with left-sided breast cancer, undergoing only adjuvant RT to the left chest, were prospectively recruited. Standard echocardiography and SI were performed at baseline, during RT, and 6 weeks after RT. Strain (S) and strain rate (Sr) parameters were measured in the longitudinal, circumferential, and radial planes. Correlation of change in global longitudinal strain (GLS % and Δ change) and the volume of heart receiving 30 Gy (V30) and mean heart dose (MHD) were examined. Results: Leftmore » ventricular ejection fraction was unchanged; however, longitudinal systolic S and Sr and radial S were significantly reduced during RT and remained reduced at 6 weeks after treatment [longitudinal S (%) −20.44 ± 2.66 baseline vs −18.60 ± 2.70* during RT vs −18.34 ± 2.86* at 6 weeks after RT; longitudinal Sr (s{sup −1}) −1.19 ± 0.21 vs −1.06 ± 0.18* vs −1.06 ± 0.16*; radial S (%) 56.66 ± 18.57 vs 46.93 ± 14.56* vs 49.22 ± 15.81*; *P<.05 vs baseline]. Diastolic Sr were only reduced 6 weeks after RT [longitudinal E Sr (s{sup −1}) 1.47 ± 0.32 vs 1.29 ± 0.27*; longitudinal A Sr (s{sup −1}) 1.19 ± 0.31 vs 1.03 ± 0.24*; *P<.05 vs baseline], whereas circumferential strain was preserved throughout. A modest correlation between S and Sr and V30 and MHD was observed (GLS Δ change and V30 ρ = 0.314, P=.05; GLS % change and V30 ρ = 0.288, P=.076; GLS Δ change and MHD ρ = 0.348, P=.03; GLS % change and MHD ρ = 0.346, P=.031). Conclusions: Subclinical myocardial dysfunction was detected by 2-dimensional SI during RT, with changes persisting 6 weeks after treatment, though long-term effects remain unknown. Additionally, a modest correlation between strain reduction and radiation dose was observed.« less

A stream-gaging network analysis for the 7-day, 10-year annual low flow in New Hampshire streams

USGS Publications Warehouse

Flynn, Robert H.

2003-01-01

The 7-day, 10-year (7Q10) low-flow-frequency statistic is a widely used measure of surface-water availability in New Hampshire. Regression equations and basin-characteristic digital data sets were developed to help water-resource managers determine surface-water resources during periods of low flow in New Hampshire streams. These regression equations and data sets were developed to estimate streamflow statistics for the annual and seasonal low-flow-frequency, and period-of-record and seasonal period-of-record flow durations. generalized-least-squares (GLS) regression methods were used to develop the annual 7Q10 low-flow-frequency regression equation from 60 continuous-record stream-gaging stations in New Hampshire and in neighboring States. In the regression equation, the dependent variables were the annual 7Q10 flows at the 60 stream-gaging stations. The independent (or predictor) variables were objectively selected characteristics of the drainage basins that contribute flow to those stations. In contrast to ordinary-least-squares (OLS) regression analysis, GLS-developed estimating equations account for differences in length of record and spatial correlations among the flow-frequency statistics at the various stations.A total of 93 measurable drainage-basin characteristics were candidate independent variables. On the basis of several statistical parameters that were used to evaluate which combination of basin characteristics contribute the most to the predictive power of the equations, three drainage-basin characteristics were determined to be statistically significant predictors of the annual 7Q10: (1) total drainage area, (2) mean summer stream-gaging station precipitation from 1961 to 90, and (3) average mean annual basinwide temperature from 1961 to 1990.To evaluate the effectiveness of the stream-gaging network in providing regional streamflow data for the annual 7Q10, the computer program GLSNET (generalized-least-squares NETwork) was used to analyze the network by application of GLS regression between streamflow and the climatic and basin characteristics of the drainage basin upstream from each stream-gaging station. Improvement to the predictive ability of the regression equations developed for the network analyses is measured by the reduction in the average sampling-error variance, and can be achieved by collecting additional streamflow data at existing stations. The predictive ability of the regression equations is enhanced even further with the addition of new stations to the network. Continued data collection at unregulated stream-gaging stations with less than 14 years of record resulted in the greatest cost-weighted reduction to the average sampling-error variance of the annual 7Q10 regional regression equation. The addition of new stations in basins with underrepresented values for the independent variables of the total drainage area, average mean annual basinwide temperature, or mean summer stream-gaging station precipitation in the annual 7Q10 regression equation yielded a much greater cost-weighted reduction to the average sampling-error variance than when more data were collected at existing unregulated stations. To maximize the regional information obtained from the stream-gaging network for the annual 7Q10, ranking of the streamflow data can be used to determine whether an active station should be continued or if a new or discontinued station should be activated for streamflow data collection. Thus, this network analysis can help determine the costs and benefits of continuing the operation of a particular station or activating a new station at another location to predict the 7Q10 at ungaged stream reaches. The decision to discontinue an existing station or activate a new station, however, must also consider its contribution to other water-resource analyses such as flood management, water quality, or trends in land use or climatic change.

A methodology for evaluation of a markup-based specification of clinical guidelines.

PubMed

Shalom, Erez; Shahar, Yuval; Taieb-Maimon, Meirav; Lunenfeld, Eitan

2008-11-06

We introduce a three-phase, nine-step methodology for specification of clinical guidelines (GLs) by expert physicians, clinical editors, and knowledge engineers, and for quantitative evaluation of the specification's quality. We applied this methodology to a particular framework for incremental GL structuring (mark-up) and to GLs in three clinical domains with encouraging results.

Long-term reliability of the Athabasca River (Alberta, Canada) as the water source for oil sands mining

PubMed Central

Sauchyn, David J.; St-Jacques, Jeannine-Marie; Luckman, Brian H.

2015-01-01

Exploitation of the Alberta oil sands, the world’s third-largest crude oil reserve, requires fresh water from the Athabasca River, an allocation of 4.4% of the mean annual flow. This allocation takes into account seasonal fluctuations but not long-term climatic variability and change. This paper examines the decadal-scale variability in river discharge in the Athabasca River Basin (ARB) with (i) a generalized least-squares (GLS) regression analysis of the trend and variability in gauged flow and (ii) a 900-y tree-ring reconstruction of the water-year flow of the Athabasca River at Athabasca, Alberta. The GLS analysis removes confounding transient trends related to the Pacific Decadal Oscillation (PDO) and Pacific North American mode (PNA). It shows long-term declining flows throughout the ARB. The tree-ring record reveals a larger range of flows and severity of hydrologic deficits than those captured by the instrumental records that are the basis for surface water allocation. It includes periods of sustained low flow of multiple decades in duration, suggesting the influence of the PDO and PNA teleconnections. These results together demonstrate that low-frequency variability must be considered in ARB water allocation, which has not been the case. We show that the current and projected surface water allocations from the Athabasca River for the exploitation of the Alberta oil sands are based on an untenable assumption of the representativeness of the short instrumental record. PMID:26392554

Utilizing pretreatment and fungal incubation to enhance the nutritional value of canola meal

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine the optimal pretreatment and fungal strain to reduce glucosinolates (GLS), fiber, and residual sugars while increasing the nutritional value of canola meal. Submerged incubation conditions were used to evaluate four pretreatment methods (extrusion, hot wa...

Blood Pressure and Left Ventricular Remodeling Among American Style Football Players

PubMed Central

Lin, Jeffrey; Wang, Francis; Weiner, Rory B.; DeLuca, James R.; Wasfy, Meagan M.; Berkstresser, Brant; Lewis, Gregory D.; Hutter, Adolph M.; Picard, Michael H.; Baggish, Aaron L.

2016-01-01

Objective To determine the relationships between American style football (ASF) participation, acquired left ventricular (LV) hypertrophy, and LV systolic function as assessed using contemporary echocardiographic parameters. Background Participation in ASF has been associated with the development of hypertension and LV hypertrophy. To what degree these processes impact LV function is unknown. Methods This is a prospective, longitudinal, cohort study evaluating NCAA Division I collegiate football athletes stratified by field position (linemen, n=30 vs. non-linemen, n=57) before and after a single competitive season with transthoracic echocardiography. LV systolic function was measured using complementary parameters of global longitudinal strain (GLS, 2D speckle-tracking) and ejection fraction (EF, 2D biplane). Results ASF participation was associated with field position-specific increases in systolic blood pressure (linemen Δ SBP = 10±8 mmHg vs. non-linemen Δ SBP = 3±7 mmHg, p<0.001) and an overall increase in incident LV hypertrophy (pre = 8% vs. post = 25%, p<0.05). Linemen who developed LV hypertrophy had concentric geometry (9/11, 82%) with decreased GLS (Δ = −1.1%, p<0.001) while non-linemen demonstrated eccentric LV hypertrophy (8/10, 80%) with increased GLS (Δ = +1.4%, p<0.001). In contrast, LV ejection fraction in the total cohort and when stratified by field position was not significantly affected by ASF participation. Among the total cohort, lineman field position, postseason weight, systolic blood pressure, average LV wall thickness, and relative wall thickness were all independent predictors of postseason GLS. Conclusions ASF participation at a lineman field position may lead to a form of sport-related myocardial remodeling that is pathologic rather than adaptive. Future study will be required to determine if targeted efforts to control blood pressure, minimize weight gain, and to include an element of aerobic conditioning in this subset of athletes may attenuate this process and translate into tangible downstream health benefits. PMID:27931524

Myocardial deformation in pediatric patients with mucopolysaccharidoses: A two-dimensional speckle tracking echocardiography study.

PubMed

Borgia, Francesco; Pezzullo, Enrica; Schiano Lomoriello, Vincenzo; Sorrentino, Regina; Lo Iudice, Francesco; Cocozza, Sara; Della Casa, Roberto; Parenti, Giancarlo; Strisciuglio, Pietro; Trimarco, Bruno; Galderisi, Maurizio

2017-02-01

Mucopolysaccharidoses (MPS) are inherited lysosomal storage disorders caused by deficiency of required glycosaminoglycans breakdown enzymes, inducing cardiac involvement. Little is known about myocardial deformation involvement in MPS. Our aim was to assess biventricular structure and function in asymptomatic children with MPS using standard echo Doppler and 2D speckle tracking (STE). Fifteen MPS children (one type I, six type II, three type III A, one III B, three IV A, one VI), asymptomatic for cardiac symptoms, and 15 age and sex-matched healthy controls underwent echo Doppler and STE. Left ventricular (LV) wall thicknesses, diameters, and mass were normalized by z-score. LV global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) at papillary muscles, LV twisting, and right ventricular (RV) GLS were measured. The two groups were comparable for body mass index, heart rate, and blood pressure. LV mass index and relative wall thickness were higher in MPS. Ejection fraction (EF), and s' velocity did not differ between the two groups. E/A ratio was lower and E/e' higher in MPS. Tricuspid annular plane systolic excursion, RV s' and e' were lower in MPS. LV GLS did not differ between the two groups, but GCS (P=.014), GRS (P=.023), twisting (P=.012), and RV GLS (P<.001) were lower in the MPS group. LV strain abnormalities are detectable in MPS pediatric patients, independently of MPS type, when EF is still normal. RV GLS is also involved consensually with TAPSE reduction. STE can be useful for detection of subclinical myocardial damage in MPS. © 2017, Wiley Periodicals, Inc.

The dose-dependent influence of zinc and cadmium contamination of soil on their uptake and glucosinolate content in white cabbage (Brassica oleracea var. capitata f. alba).

PubMed

Kusznierewicz, Barbara; Bączek-Kwinta, Renata; Bartoszek, Agnieszka; Piekarska, Anna; Huk, Anna; Manikowska, Anna; Antonkiewicz, Jacek; Namieśnik, Jacek; Konieczka, Piotr

2012-11-01

The relationship between the ability to accumulate heavy metals (represented by Cd and Zn) and to synthesize bioactive compounds (represented by glucosinolates [GLS]) was investigated in two cabbage cultivars. Plants were grown in the greenhouse of a phytotron under controlled conditions in soils spiked with two different Zn or Cd concentrations. The measurements of Cd and Zn contents in soil and cabbage (leaf) samples were performed by atomic absorption spectroscopy, whereas GLS levels in cabbage were determined by high-performance liquid chromatography. The ranges of metal contents in soil were 80 to 450 mg/kg dry weight for Zn and 0.3 to 30 mg/kg dry weight for Cd, whereas the levels of accumulated Zn and Cd in cabbage amounted to 15 to 130 and 0.02 to 3 mg/kg dry weight, respectively. After initial symptoms of toxicity, during a later stage of growth, the plants exhibited very good tolerance to both metals. Enhanced biosynthesis of GLS was observed in a dose-dependent manner following exposure to the heavy metals. The GLS content in Zn-exposed cabbage rose from 3.2 to 12 µmol/g dry weight, and the corresponding values for Cd-treated plants were 3.5 to 10 µmol/g dry weight. Thus, the increased soil contamination by metals caused greater accumulation in cabbage, as well as stimulation of GLS biosynthesis. The results obtained point to the high phytoremediation and biofumigation potential of white cabbage. Copyright © 2012 SETAC.

Targeting glutamine metabolism in myeloproliferative neoplasms

PubMed Central

Zhan, Huichun; Ciano, Kristen; Dong, Katherine; Zucker, Stanley

2016-01-01

JAK2V617F mutation can be detected in the majority of myeloproliferative neoplasm (MPN) patients. The JAK2 inhibitor Ruxolitinib is the first FDA-approved treatment for MPNs. However, its use is limited by various dose related toxicities. Here, we studied the metabolic state and glutamine metabolism of BaF3-hEPOR-JAK2V617F and BaF3-hEPOR-JAK2WT cells. We found that the JAK2V617F-mutant cells were associated with increased oxygen consumption rate and extracellular acidification rate than the JAK2WT cells and there was an increased glutamine metabolism in JAK2V617F-mutant cells compared to wild-type cells. Glutaminase (GLS), the key enzyme in gluta-mine metabolism, was upregulated in the JAK2V617F-mutant BaF3 cells compared to the JAK2WT BaF3 cells. In MPN patient peripheral blood CD34+ cells, GLS expression was increased in JAK2V617F-mutant progenitor cells compared to JAK2 wild-type progenitor cells from the same patients and GLS levels were increased at the time of disease progression compared to at earlier time points. Moreover, GLS inhibitor increased the growth inhibitory effect of Ruxolitinib in both JAK2V617F-mutant cell lines and peripheral blood CD34+ cells from MPN patients. Therefore, GLS inhibitor should be further explored to enhance the therapeutic effectiveness of JAK2 inhibitor and allow the administration of lower doses of the drug to avoid its toxicity. PMID:26227854

Validation of consensus quantitative trait loci associated with resistance to multiple foliar pathogens of maize.

PubMed

Asea, Godfrey; Vivek, Bindiganavile S; Bigirwa, George; Lipps, Patrick E; Pratt, Richard C

2009-05-01

Maize production in sub-Saharan Africa incurs serious losses to epiphytotics of foliar diseases. Quantitative trait loci conditioning partial resistance (rQTL) to infection by causal agents of gray leaf spot (GLS), northern corn leaf blight (NCLB), and maize streak have been reported. Our objectives were to identify simple-sequence repeat (SSR) molecular markers linked to consensus rQTL and one recently identified rQTL associated with GLS, and to determine their suitability as tools for selection of improved host resistance. We conducted evaluations of disease severity phenotypes in separate field nurseries, each containing 410 F2:3 families derived from a cross between maize inbred CML202 (NCLB and maize streak resistant) and VP31 (a GLS-resistant breeding line) that possess complimentary rQTL. F2:3 families were selected for resistance based on genotypic (SSR marker), phenotypic, or combined data and the selected F3:4 families were reevaluated. Phenotypic values associated with SSR markers for consensus rQTL in bins 4.08 for GLS, 5.04 for NCLB, and 1.04 for maize streak significantly reduced disease severity in both generations based on single-factor analysis of variance and marker-interval analysis. These results were consistent with the presence of homozygous resistant parent alleles, except in bin 8.06, where markers were contributed by the NCLB-susceptible parent. Only one marker associated with resistance could be confirmed in bins 2.09 (GLS) and 3.06 (NCLB), illustrating the need for more robust rQTL discovery, fine-mapping, and validation prior to undertaking marker-based selection.

Solid state fermentation of carinata (Brassica carinata) meal using various fungal strains to produce a protein-rich product for feed application

USDA-ARS?s Scientific Manuscript database

In this study, the efficacy of several fungal strains to reduce GLS (GLS) content and enhance protein content during solid state fermentation (SSF) of carinata meal was evaluated. Solid state fermentation of hexane extracted (HE) and cold pressed (CP) carinata meals were performed at 50% moisture co...

Mitral annular plane systolic excursion/left ventricular length (MAPSE/L) as a simple index for assessing left ventricular longitudinal function in children.

PubMed

Terada, Tomomasa; Mori, Kazuhiro; Inoue, Miki; Yasunobu, Hayabuchi

2016-11-01

Assessment of longitudinal left ventricular (LV) function is important for early detection of cardiac dysfunction. Although mitral annular plane systolic excursion (MAPSE) obtained by M-mode echocardiography offers a simple method for assessing longitudinal LV function, normal values of MAPSE for children change according to body size. To minimize the effects of body size, MAPSE was divided by LV long-axis length (MAPSE/L). MAPSE/L was measured in 210 healthy children from birth to 15 years of age and classified into five subgroups. MAPSE/L was then compared with 10 parameters in 136 children (age, heart rate, mean blood pressure, ejection fraction of the LV (EF), peak atrial flow velocity/peak early diastolic flow velocity of mitral flow, tissue Doppler velocity during systole (s') and early diastole (e'), E/e' ratio, Tei index, and global longitudinal strain (GLS) of the LV by the speckle tracking method). MAPSE/L was significantly lower in the neonate group than in the remaining four groups. MAPSE/L then increased with age to peak at 1-5 years and gradually decreased thereafter. In all cases beyond the neonatal period, MAPSE/L was more than 0.17. Among various parameters, GLS, age, EF, Tei index and s' were significantly associated with MAPSE/L in that order. In univariate analysis, GLS was most significantly associated with MAPSE/L (r=.56). We have established normal reference values for MPSE/L in healthy children. MAPSE/L is expected to offer a simple parameter to evaluate LV longitudinal systolic function during daily routine echocardiography in children. © 2016, Wiley Periodicals, Inc.

Synergistic Utility of Brain Natriuretic Peptide and Left Ventricular Global Longitudinal Strain in Asymptomatic Patients With Significant Primary Mitral Regurgitation and Preserved Systolic Function Undergoing Mitral Valve Surgery.

PubMed

Alashi, Alaa; Mentias, Amgad; Patel, Krishna; Gillinov, A Marc; Sabik, Joseph F; Popović, Zoran B; Mihaljevic, Tomislav; Suri, Rakesh M; Rodriguez, L Leonardo; Svensson, Lars G; Griffin, Brian P; Desai, Milind Y

2016-07-01

In asymptomatic patients with ≥3+ mitral regurgitation and preserved left ventricular (LV) ejection fraction who underwent mitral valve surgery, we sought to discover whether baseline LV global longitudinal strain (LV-GLS) and brain natriuretic peptide provided incremental prognostic utility. Four hundred and forty-eight asymptomatic patients (61±12 years and 69% men) with ≥3+ primary mitral regurgitation and preserved left ventricular ejection fraction, who underwent mitral valve surgery (92% repair) at our center between 2005 and 2008, were studied. Baseline clinical and echocardiographic data (including LV-GLS using Velocity Vector Imaging, Siemens, PA) were recorded. The Society of Thoracic Surgeons score was calculated. The primary outcome was death. Mean Society of Thoracic Surgeons score, left ventricular ejection fraction, mitral effective regurgitant orifice, indexed LV end-diastolic volume, and right ventricular systolic pressure were 4±1%, 62±3%, 0.55±0.2 cm(2), 58±13 cc/m(2), and 37±15 mm Hg, respectively. Forty-five percent of patients had flail. Median log-transformed BNP and LV-GLS were 4.04 (absolute brain natriuretic peptide: 60 pg/dL) and -20.7%. At 7.7±2 years, death occurred in 41 patients (9%; 0% at 30 days). On Cox analysis, a higher Society of Thoracic Surgeons score (hazard ratio 1.55), higher baseline right ventricular systolic pressure (hazard ratio 1.11), more abnormal LV-GLS (hazard ratio 1.17), and higher median log-transformed BNP (hazard ratio 2.26) were associated with worse longer-term survival (all P<0.01). Addition of LV-GLS and median log-transformed BNP to a clinical model (Society of Thoracic Surgeons score and baseline right ventricular systolic pressure) provided incremental prognostic utility (χ(2) for longer-term mortality increased from 31-47 to 61; P<0.001). In asymptomatic patients with significant primary mitral regurgitation and preserved left ventricular ejection fraction who underwent mitral valve surgery, brain natriuretic peptide and LV-GLS provided synergistic risk stratification, independent of established factors. © 2016 American Heart Association, Inc.

Outcomes in Asymptomatic Severe Aortic Stenosis With Preserved Ejection Fraction Undergoing Rest and Treadmill Stress Echocardiography.

PubMed

Huded, Chetan P; Masri, Ahmad; Kusunose, Kenya; Goodman, Andrew L; Grimm, Richard A; Gillinov, A Marc; Johnston, Douglas R; Rodriguez, L Leonardo; Popovic, Zoran B; Svensson, Lars G; Griffin, Brian P; Desai, Milind Y

2018-04-12

In asymptomatic patients with severe aortic stenosis and preserved left ventricular ejection fraction, we sought to assess the incremental prognostic value of resting valvuloarterial impedence (Zva) and left ventricular global longitudinal strain (LV-GLS) to treadmill stress echocardiography. We studied 504 such patients (66±12 years, 78% men, 32% with coronary artery disease who underwent treadmill stress echocardiography between 2001 and 2012. Clinical and exercise variables (% of age-sex predicted metabolic equivalents [%AGP-METs]) were recorded. Resting Zva ([systolic arterial pressure+mean aortic valve gradient]/[LV-stroke volume index]) and LV-GLS (measured offline using Velocity Vector Imaging, Siemens) were obtained from the baseline resting echocardiogram. Death was the primary outcome. There were no major adverse cardiac events during treadmill stress echocardiography. Indexed aortic valve area, Zva, and LV-GLS were 0.46±0.1 cm 2 /m 2 , 4.5±0.9 mm Hg/mL per m 2 and -16±4%, respectively; only 50% achieved >100% AGP-METs. Sixty-four percent underwent aortic valve replacement. Death occurred in 164 (33%) patients over 8.9±3.6 years (2 within 30 days of aortic valve replacement). On multivariable Cox survival analysis, higher Society of Thoracic Surgeons score (hazard ratio or HR 1.06), lower % AGP-METS (HR 1.16), higher Zva (HR 1.25) and lower LV-GLS (HR 1.12) were associated with higher longer-term mortality, while aortic valve replacement (HR 0.45) was associated with improved survival (all P <0.01). Sequential addition of ZVa and LV-GLS to clinical model (Society of Thoracic Surgeons score and %AGP-METs) increased the c-statistic from 0.65 to 0.69 and 0.75, respectively, both P <0.001); findings were similar in the subgroup of patients who underwent aortic valve replacement. In asymptomatic patients with severe aortic stenosis undergoing treadmill stress echocardiography, LV-GLS and ZVa offer incremental prognostic value. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

The integrated value of sST2 and global longitudinal strain in the early stratification of patients with severe aortic valve stenosis: a translational imaging approach.

PubMed

Fabiani, Iacopo; Conte, Lorenzo; Pugliese, Nicola Riccardo; Calogero, Enrico; Barletta, Valentina; Di Stefano, Rossella; Santoni, Tatiana; Scatena, Cristian; Bortolotti, Uberto; Naccarato, Antonio Giuseppe; Petronio, Anna Sonia; Di Bello, Vitantonio

2017-12-01

Aortic valve stenosis (AVS) is associated with significant myocardial fibrosis (MF). Global longitudinal strain (GLS) is a sensible indicator of systolic dysfunction. ST2 is a member of the interleukin (IL)-1 receptor family and a modulator of hypertrophic and fibrotic responses. We aimed at assessing: (a) the association between adverse LV remodeling, LV functional parameters (including GLS) and sST2 level. (b) The association between MF (detected by endo-myocardial biopsy) and sST2 in patients with AVS undergoing surgical valve replacement. Twenty-two patients with severe AVS and preserved EF underwent aortic valve replacement. They performed laboratory analysis, including serum ST2 (sST2), echocardiography and inter-ventricular septum biopsy to assess MF (%). We included ten controls for comparison. Compared to controls, patients showed higher sST2 levels (p < 0.0001). sST2 showed correlation with Age (r = 0.58; p = 0.0004), E/e' average (r = 0.58; p = 0.0007), GLS (r = 0.61; p = 0.0002), LAVi (r = 0.51; p = 0.003), LVMi (r = 0.43; p = 0.01), sPAP (r = 0.36; p = 0.04) and SVi (r = -0.47; p < 0.005). No correlation was found between MF and sST2. At ROC analysis, a sST2 ≥ 284 ng/mL had the best accuracy to discriminate controls from patients with impaired GLS, i.e. GLS ≤ 17% (AUC 0.80; p = 0.003; sensitivity 95%; specificity 83%) and increased E/e' average (AUC 0.87; p = 0.0001; sensitivity 96%; specificity 74%). At multivariate regression analysis GLS resulted the only independent predictor of sST2 levels (R 2  = 0.35; p =  0.0004). Patients with severe AVS present elevated sST2 levels. LV GLS resulted the only independent predictor of sST2 levels.

Prevalence and Correlates of Early Right Ventricular Dysfunction in Sarcoidosis and Its Association with Outcome.

PubMed

Joyce, Emer; Kamperidis, Vasileios; Ninaber, Maarten K; Katsanos, Spyridon; Debonnaire, Philippe; Schalij, Martin J; Taube, Christian; Bax, Jeroen J; Delgado, Victoria; Ajmone Marsan, Nina

2016-09-01

Right ventricular (RV) function has not been systematically assessed in sarcoidosis. The aim of this study was to assess the prevalence and associates of RV dysfunction in sarcoidosis using global longitudinal peak systolic strain (GLS). Furthermore, whether RV dysfunction was associated with clinical outcomes was investigated. A total of 88 patients with sarcoidosis (mean age, 54 ± 13 years; 51% men) without known sarcoid-related or other structural heart disease or alternative etiologies of pulmonary hypertension were retrospectively included. RV GLS was measured using two-dimensional speckle-tracking echocardiography, and patients were stratified (using a previously defined cutoff value) as having preserved (RV GLS < -19%) or impaired (RV GLS ≥ -19%) RV function. An age- and gender-matched control group (n = 50) was included. The main outcome was all-cause mortality or clinical heart failure (hospitalization or New York Heart Association functional class ≥ III and/or deterioration by one or more classes). RV GLS was significantly reduced (-20.1 ± 4.6 vs -24.6 ± 1.8%, P = .001) in patients compared with control subjects. Patients with impaired RV function (n = 41) were older and had worse pulmonary function, worse left ventricular diastolic function, and lower tricuspid annular plane systolic excursion compared with patients with preserved RV function (n = 47). Lower tricuspid annular plane systolic excursion and diabetes were independent correlates of RV GLS. Over a median follow-up period of 37 months, 19 clinical end points occurred. Patients with impaired RV function were more likely to experience the clinical end point (log-rank P = .003). RV contractile dysfunction, identified using RV GLS, is common in patients with sarcoidosis without manifest cardiac involvement or pulmonary hypertension and is associated with adverse outcome. RV GLS may therefore be useful to detect sarcoidosis-related RV dysfunction at an earlier and potentially modifiable stage. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Associations of childhood and adult obesity with left ventricular structure and function.

PubMed

Yang, H; Huynh, Q L; Venn, A J; Dwyer, T; Marwick, T H

2017-04-01

Overweight and obesity are associated with left ventricular (LV) dysfunction. We sought whether echocardiographic evidence of abnormal adult cardiac structure and function was related to childhood or adult adiposity. This study included 159 healthy individuals aged 7-15 years and followed until age 36-45 years. Anthropometric measurements were performed both at baseline and follow-up. Cardiac structure (indexed left atrial volume (LAVi), left ventricular mass (LVMi)) and LV function (global longitudinal strain (GLS), mitral e') were assessed using standard echocardiography at follow-up. Conventional cutoffs were used to define abnormal LAVi, LVMi, GLS and mitral annular e'. Childhood body mass index (BMI) was correlated with LVMi (r=0.25, P=0.002), and child waist circumference was correlated with LVMi (r=0.18, P=0.03) and LAVi (r=0.20, P=0.01), but neither were correlated with GLS. One s.d. (by age and sex) increase in childhood BMI was associated with LV hypertrophy (relative risk: 2.04 (95% confidence interval (CI): 1.09, 3.78)) and LA enlargement (relative risk: 1.81 (95% CI: 1.02, 3.21)) independent of adult BMI, but the association was not observed with impaired GLS or mitral e'. Cardiac functional measures were more impaired in those who had normal BMI as child, but had high BMI in adulthood (P<0.03), and not different in those who were overweight or obese as a child and remained so in adulthood (P>0.33). Childhood adiposity is independently associated with structural cardiac disturbances (LVMi and LAVi). However, functional alterations (GLS and mitral e') were more frequently associated with adult overweight or obesity, independent of childhood adiposity.

Quantitative assessment of the entire right ventricle from one acoustic window: an attractive approach.

PubMed

McGhie, Jackie S; Menting, Myrthe E; Vletter, Wim B; Frowijn, René; Roos-Hesselink, Jolien W; van der Zwaan, Heleen B; Soliman, Osama I I; Geleijnse, Marcel L; van den Bosch, Annemien E

2017-07-01

The aim of this prospective study was to evaluate the feasibility and establish normal values of functional right ventricle (RV) parameters as assessed in our four, long-axis view RV model using iRotate echocardiography. Furthermore, we evaluated the potential use of this model in patients with abnormally loaded RVs. One hundred and fifty-five healthy subjects aged 20-72 years (≥28 subjects per decile) were prospectively recruited. We used non-dedicated RV speckle-tracking software to test the feasibility and to establish normal range values of peak systolic global longitudinal RV strain (RV-GLS) from the RV free-walls (septum was excluded). Also normal range values for: dimensions, tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (TDI-S') were established. The feasibility of RV-GLS was 88, 84, and 62%, respectively, in the lateral, inferior, and anterior free wall. Mean RV-GLS normal values were -24.5 ± 4.9% for lateral wall and -25.4 ± 5.0% for anterior wall. Mean RV-GLS in the inferior wall was -23.2 ± 4.4% in the aortic (Ao) view and -20.7 ± 5.0% in the coronal (CV) view. The feasibility of mean RV-GLS was 100% in the anterior, lateral, and inferior walls in abnormally dilated RVs. The feasibility of all RV parameters assessed in the four-view iRotate model is good to excellent. Normal values for RV dimension and function of the anterior, inferior, and lateral RV walls have been established. Further studies and dedicated RV speckle-tracking software are warranted to discover the full potential of this new technique. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions, please email: journals.permissions@oup.com.

Assessment of Myocardial Infarct Size by Three-Dimensional and Two-Dimensional Speckle Tracking Echocardiography: A Comparative Study to Single Photon Emission Computed Tomography.

PubMed

Wang, Qiushuang; Huang, Dangsheng; Zhang, Liwei; Shen, Dong; Ouyang, Qiaohong; Duan, Zhongxiang; An, Xiuzhi; Zhang, Meiqing; Zhang, Chunhong; Yang, Feifei; Zhi, Guang

2015-10-01

To compare three-dimensional (3D) and two-dimensional (2D) speckle tracking echocardiography (STE) techniques in the assessment of left ventricular function and myocardial infarct size (MIS). Thirty-two patients diagnosed with ST elevation myocardial infarction and 18 healthy control patients underwent 2D echocardiography, 3D echocardiography, and single photon emission computed tomography (SPECT). 3D left ventricular global area strain (GAS), 2D and 3D global longitudinal strain (GLS), global radial strain (GRS) as well as global circumferential strain (GCS) were analyzed to correlate with myocardial infarct size detected by SPECT. 2D and 3D left ventricular ejection fraction (LVEF) as well as 2D and 3D wall motion score index (WMSI) also were measured using conventional echocardiography. The 2D-GLS values were significantly higher than that of 3D-GLS, while 2D-GCS and GRS were significantly lower than 3D-GCS and GRS, respectively. However, no significant differences in LVEF and WMSI could be observed between 2D and 3D echocardiography. Myocardial strain indices, LVEF, and WMSI using 2D and 3D echocardiography also had good correlations with MIS as measured by SPECT. ROC curve analysis showed that the 3D and 2D myocardial indices, LVEF, and WMSI could distinguish between small and large MIS, while 2D-GLS had the highest AUC. The 2D and 3D myocardial strain indices correlated well with MIS by SPECT. Among them, the 2D-GLS showed the highest diagnostic value, while 3D-GRS and GCS had better diagnostic value than 2D-GRS and GCS. © 2015, Wiley Periodicals, Inc.

Value of tissue Doppler-derived Tei index and two-dimensional speckle tracking imaging derived longitudinal strain on predicting outcome of patients with light-chain cardiac amyloidosis.

PubMed

Liu, Dan; Hu, Kai; Herrmann, Sebastian; Cikes, Maja; Ertl, Georg; Weidemann, Frank; Störk, Stefan; Nordbeck, Peter

2017-06-01

Prognosis of patients with light-chain cardiac amyloidosis (AL-CA) is poor. Speckle tracking imaging (STI) derived longitudinal deformation parameters and Doppler-derived left ventricular (LV) Tei index are valuable predictors of outcome in patients with AL-CA. We estimated the prognostic utility of Tei index and deformation parameters in 58 comprehensively phenotyped patients with AL-CA after a median follow-up of 365 days (quartiles 121, 365 days). The primary end point was all-cause mortality. 19 (33%) patients died during follow-up. Tei index (0.89 ± 0.29 vs. 0.61 ± 0.16, p < 0.001) and E to global early diastolic strain rate ratio (E/GLSR dias ) were higher while global longitudinal systolic strain (GLS sys ) was lower in non-survivors than in survivors (all p < 0.05). Tei index, NYHA functional class, GLS sys and E/GLSR dias were independent predictors of all-cause mortality risk, and Tei index ≥0.9 (HR 7.01, 95% CI 2.43-20.21, p < 0.001) was the best predictor of poor outcome. Combining Tei index and GLS sys yielded the best results on predicting death within 1 year (100% with Tei index ≥0.9 and GLS sys ≤13%) or survival (95% with Tei index ≤0.9 and GLS sys ≥13%). We conclude that 1-year mortality risk in AL-CA patients can be reliably predicted using Tei index or deformation parameters, with combined analysis offering best performance.

Heat Shock Factor 1 Epigenetically Stimulates Glutaminase-1-Dependent mTOR Activation to Promote Colorectal Carcinogenesis.

PubMed

Li, Jiaqiu; Song, Ping; Jiang, Tingting; Dai, Dongjun; Wang, Hanying; Sun, Jie; Zhu, Liyuan; Xu, Wenxia; Feng, Lifeng; Shin, Vivian Y; Morrison, Helen; Wang, Xian; Jin, Hongchuan

2018-04-14

Heat shock factor 1 (HSF1) generally exhibits its properties under stress conditions. In tumors, HSF1 has a pleiotropic feature in regulating growth, survival, and aggressiveness of cancer cells. In this study, we found HSF1 was increased in colorectal cancer (CRC) and had a positive correlation with shorter disease-free survival (DFS). Knockdown of HSF1 in CRC cells attenuated their growth while inhibiting mTOR activation and glutamine metabolism. HSF1 inhibited the expression of microRNA137 (MIR137), which targeted GLS1 (glutaminase 1), thus stimulating GLS1 protein expression to promote glutaminolysis and mTOR activation. HSF1 bound DNA methyltransferase DNMT3a and recruited it to the promoter of lncRNA MIR137 host gene (MIR137HG), suppressing the generation of primary MIR137. The chemical inhibitor of HSF1 also reduced cell growth, increased apoptosis, and impaired glutamine metabolism in vitro. Moreover, both chemical inhibition and genetic knockout of HSF1 succeeded in increasing MIR137 expression, reducing GLS1 expression, and alleviating colorectal tumorigenesis in azoxymethane (AOM)/dextran sulfate sodium (DSS) mice. In conclusion, HSF1 expression was increased and associated with poor prognosis in CRC. By recruiting DNMT3a to suppress the expression of MIR137 that targets GLS1 mRNA, HSF1 stimulated GLS1-dependent mTOR activation to promote colorectal carcinogenesis. Therefore, targeting HSF1 to attenuate glutaminolysis and mTOR activation could be a promising approach for CRC treatment. Copyright © 2018 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Global longitudinal strain in patients with suspected heart failure and a normal ejection fraction: does it improve diagnosis and risk stratification?

PubMed

Pellicori, Pierpaolo; Kallvikbacka-Bennett, Anna; Khaleva, Olga; Carubelli, Valentina; Costanzo, Pierluigi; Castiello, Teresa; Wong, Kenneth; Zhang, Jufen; Cleland, John G F; Clark, Andrew L

2014-01-01

Many patients have clinical, structural or bio-marker evidence of heart failure (HF) but a normal left ventricular ejection fraction (LVEF; HeFNEF). Measurement of global longitudinal strain (GLS) may add diagnostic and prognostic information. Patients with symptoms suggesting heart failure and LVEF ≥50% were studied: 76 had no substantial cardiac dysfunction (left atrial diameter (LAD) <40 mm and amino-terminal pro-brain natriuretic peptide (NTproBNP) <400 ng/l); 99 had "possible HeFNEF" (LAD ≥40 mm or NTproBNP ≥400 ng/l); and 138 had "definite HeFNEF" (LAD ≥40 mm and NTproBNP ≥400 ng/L). Mean LVEF was 58% in each subgroup. Patients with definite HeFNEF were older, more likely to have atrial fibrillation, had more symptoms and signs of fluid retention, were more likely to have right ventricular dysfunction and had higher pulmonary pressures than other groups. Mean GLS (SD) was less negative in patients with definite HeFNEF (-13.6 (3.0)% vs. possible HeFNEF: -15.2 (3.1)% vs. no substantial cardiac dysfunction: -15.9 (2.4)%; p < 0.001). GLS was -19.1 (2.1)% in 20 controls. During a median follow up of 647 days, cardiovascular death or an unplanned hospitalisation for heart failure occurred in 62 patients. In univariable analysis, GLS but not LVEF predicted events. However, in a multi-variable analysis, only urea, NTproBNP, left atrial volume, inferior vena cava diameter and atrial fibrillation independently predicted adverse outcome. GLS is abnormal in patients who have other evidence of HeFNEF, is associated with a worse prognosis in this population but is not a powerful independent predictor of outcome.

Intraobserver reproducibility of parameters of standard and 2D speckle tracking echocardiography, dynamics of global longitudinal strain I in patients with acute primary anterior STEMI

NASA Astrophysics Data System (ADS)

Kercheva, M.; Ryabova, T.; Ryabov, V.; Karpov, R.

2015-11-01

The aim of this study was to assess the intraobserver reproducibility of parameters of standard and 2 dimensional speckle tracking echocardiography, dynamics of global longitudinal strain in patients with acute primary anterior STEMI. The study included 24 patients, mean age 58.46±10.2. Echocardiography with 2D speckle tracking imaging was performed on the 1st (T1), 7th (T2), 14th days (T3) after STEMI («Vivid E9»). Analysis of echocardiographic images was performed offline at the different periods by the two independent observers (EchoPac) - experienced and inexperienced. In order to assess the agreement between standard and 2D speckle tracking echocardiography, a correlation analysis (Pearson correlation, Spearman's rank correlation coefficient) and Bland-Altman analysis were undertaken. The 23 patients had urgent reperfusion therapy, 6 patients underwent primary PCI, 16 patients - PCI after successful fibrinolysis (68%). GLS and WMSI had the best intraobsever reproducibility. Dynamics of EDV LV, ESV LV, EF LV was without significant differences. Nevertheless, it was found positive dynamic of GLS: - 12.65±3.53 (T1), -13.61±3.81 (T2), -14.27±4.1 (T3), p<0.05. GLS reduced 11.35% (p=0.0048) from T1 to T3. The best intraobserver reproducibility of parameters of 2 D speckle-tracking and standard echocardiography was revealed in GLS and WMSI. The modern management of STEMI patients limits adverse postinfarction remodeling and preserves of global left ventricular contractility detected by the EF LV. However, GLS had the positive dynamics and improved to the 14th day.

Altered seed oil and glucosinolate levels in transgenic plants overexpressing the Brassica napus SHOOTMERISTEMLESS gene.

PubMed

Elhiti, Mohamed; Yang, Cunchun; Chan, Ainsley; Durnin, Douglas C; Belmonte, Mark F; Ayele, Belay T; Tahir, Muhammad; Stasolla, Claudio

2012-07-01

SHOOTMERISTEMLESS (STM) is a homeobox gene conserved among plant species which is required for the formation and maintenance of the shoot meristem by suppressing differentiation and maintaining an undetermined cell fate within the apical pole. To assess further the role of this gene during seed storage accumulation, transgenic Brassica napus (Bn) plants overexpressing or down-regulating BnSTM under the control of the 35S promoter were generated. Overexpression of BnSTM increased seed oil content without affecting the protein and sucrose level. These changes were accompanied by the induction of genes encoding several transcription factors promoting fatty acid (FA) synthesis: LEAFY COTYLEDON1 (BnLEC1), BnLEC2, and WRINKLE1 (BnWRI1). In addition, expression of key representative enzymes involved in sucrose metabolism, glycolysis, and FA biosynthesis was up-regulated in developing seeds ectopically expressing BnSTM. These distinctive expression patterns support the view of an increased carbon flux to the FA biosynthetic pathway in developing transformed seeds. The overexpression of BnSTM also resulted in a desirable reduction of seed glucosinolate (GLS) levels ascribed to a transcriptional repression of key enzymes participating in the GLS biosynthetic pathway, and possibly to the differential utilization of common precursors for GLS and indole-3-acetic acid synthesis. No changes in oil and GLS levels were observed in lines down-regulating BnSTM. Taken together, these findings provide evidence for a novel function for BnSTM in promoting desirable changes in seed oil and GLS levels when overexpressed in B. napus plants, and demonstrate that this gene can be used as a target for genetic improvement of oilseed species.

Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis).

PubMed

Zhang, Xinye; Yang, Qin; Rucker, Elizabeth; Thomason, Wade; Balint-Kurti, Peter

2017-06-01

In this study we mapped the QTL Qgls8 for gray leaf spot (GLS) resistance in maize to a ~130 kb region on chromosome 8 including five predicted genes. In previous work, using near isogenic line (NIL) populations in which segments of the teosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot (GLS) resistance. We identified alternate teosinte alleles at this QTL, one conferring increased GLS resistance and one increased susceptibility relative to the B73 allele. Using segregating populations derived from NIL parents carrying these contrasting alleles, we were able to delimit the QTL region to a ~130 kb (based on the B73 genome) which encompassed five predicted genes.

Maturational Patterns of Systolic Ventricular Deformation Mechanics by Two-Dimensional Speckle-Tracking Echocardiography in Preterm Infants over the First Year of Age.

PubMed

Levy, Philip T; El-Khuffash, Afif; Patel, Meghna D; Breatnach, Colm R; James, Adam T; Sanchez, Aura A; Abuchabe, Cristina; Rogal, Sarah R; Holland, Mark R; McNamara, Patrick J; Jain, Amish; Franklin, Orla; Mertens, Luc; Hamvas, Aaron; Singh, Gautam K

2017-07-01

The aim of this study was to determine the maturational changes in systolic ventricular strain mechanics by two-dimensional speckle-tracking echocardiography in extremely preterm neonates from birth to 1 year of age and discern the impact of common cardiopulmonary abnormalities on the deformation measures. In a prospective multicenter study of 239 extremely preterm infants (<29 weeks gestation at birth), left ventricular (LV) global longitudinal strain (GLS) and global longitudinal systolic strain rate (GLSRs), interventricular septal wall (IVS) GLS and GLSRs, right ventricular (RV) free wall longitudinal strain and strain rate, and segmental longitudinal strain in the RV free wall, LV free wall, and IVS were serially measured on days 1, 2, and 5 to 7, at 32 and 36 weeks postmenstrual age, and at 1 year corrected age (CA). Premature infants who developed bronchopulmonary dysplasia or had echocardiographic findings of pulmonary hypertension were analyzed separately. In uncomplicated preterm infants (n = 103 [48%]), LV GLS and GLSRs remained unchanged from days 5 to 7 to 1 year CA (P = .60 and P = .59). RV free wall longitudinal strain, RV free wall longitudinal strain rate, and IVS GLS and GLSRs significantly increased over the same time period (P < .01 for all measures). A significant base-to-apex (highest to lowest) segmental longitudinal strain gradient (P < .01) was seen in the RV free wall and a reverse apex-to-base gradient (P < .01) in the LV free wall. In infants with bronchopulmonary dysplasia and/or pulmonary hypertension (n = 119 [51%]), RV free wall longitudinal strain and IVS GLS were significantly lower (P < .01), LV GLS and GLSRs were similar (P = .56), and IVS segmental longitudinal strain persisted as an RV-dominant base-to-apex gradient from 32 weeks postmenstrual age to 1 year CA. This study tracks the maturational patterns of global and regional deformation by two-dimensional speckle-tracking echocardiography in extremely preterm infants from birth to 1 year CA. The maturational patterns are ventricular specific. Bronchopulmonary dysplasia and pulmonary hypertension leave a negative impact on RV and IVS strain, while LV strain remains stable. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Oxidative Stress State Is Associated with Left Ventricular Mechanics Changes, Measured by Speckle Tracking in Essential Hypertensive Patients.

PubMed

Moreno-Ruíz, Luis Antonio; Ibarra-Quevedo, David; Rodríguez-Martínez, Erika; Maldonado, Perla D; Sarabia-Ortega, Benito; Hernández-Martínez, José Gustavo; Espinosa-Caleti, Beda; Mendoza-Pérez, Beatriz; Rivas-Arancibia, Selva

2015-01-01

The oxidative stress state is characterized by an increase in oxygen reactive species that overwhelms the antioxidant defense; we do not know if these pathological changes are correlated with alterations in left ventricular mechanics. The aim was correlating the oxidative stress state with the left ventricular global longitudinal strain (GLS) and the left ventricular end diastolic pressure (LVEDP). Twenty-five patients with essential hypertension and 25 controls paired by age and gender were studied. All of the participants were subjected to echocardiography and biochemical determination of oxidative stress markers. The hypertensive patients, compared with control subjects, had significantly (p < 0.05) higher levels of oxidized proteins (5.03 ± 1.05 versus 4.06 ± 0.63 nmol/mg), lower levels of extracellular superoxide dismutase (EC-SOD) activity (0.045 ± 0.02 versus 0.082 ± 0.02 U/mg), higher LVEDP (16.2 ± 4.5 versus 11.3 ± 1.6 mm Hg), and lower GLS (-12% versus -16%). Both groups had preserved ejection fraction and the results showed a positive correlation of oxidized proteins with GLS (r = 0.386, p = 0.006) and LVEDP (r = 0.389, p = 0.005); we also found a negative correlation of EC-SOD activity with GLS (r = -0.404, p = 0.004) and LVEDP (r = -0.347, p = 0.014).

Discretization and Preconditioning Algorithms for the Euler and Navier-Stokes Equations on Unstructured Meshes

NASA Technical Reports Server (NTRS)

Barth, Timothy J.; Kutler, Paul (Technical Monitor)

1998-01-01

Several stabilized demoralization procedures for conservation law equations on triangulated domains will be considered. Specifically, numerical schemes based on upwind finite volume, fluctuation splitting, Galerkin least-squares, and space discontinuous Galerkin demoralization will be considered in detail. A standard energy analysis for several of these methods will be given via entropy symmetrization. Next, we will present some relatively new theoretical results concerning congruence relationships for left or right symmetrized equations. These results suggest new variants of existing FV, DG, GLS, and FS methods which are computationally more efficient while retaining the pleasant theoretical properties achieved by entropy symmetrization. In addition, the task of Jacobean linearization of these schemes for use in Newton's method is greatly simplified owing to exploitation of exact symmetries which exist in the system. The FV, FS and DG schemes also permit discrete maximum principle analysis and enforcement which greatly adds to the robustness of the methods. Discrete maximum principle theory will be presented for general finite volume approximations on unstructured meshes. Next, we consider embedding these nonlinear space discretizations into exact and inexact Newton solvers which are preconditioned using a nonoverlapping (Schur complement) domain decomposition technique. Elements of nonoverlapping domain decomposition for elliptic problems will be reviewed followed by the present extension to hyperbolic and elliptic-hyperbolic problems. Other issues of practical relevance such the meshing of geometries, code implementation, turbulence modeling, global convergence, etc, will. be addressed as needed.

Discretization and Preconditioning Algorithms for the Euler and Navier-Stokes Equations on Unstructured Meshes

NASA Technical Reports Server (NTRS)

Barth, Timothy; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

Several stabilized discretization procedures for conservation law equations on triangulated domains will be considered. Specifically, numerical schemes based on upwind finite volume, fluctuation splitting, Galerkin least-squares, and space discontinuous Galerkin discretization will be considered in detail. A standard energy analysis for several of these methods will be given via entropy symmetrization. Next, we will present some relatively new theoretical results concerning congruence relationships for left or right symmetrized equations. These results suggest new variants of existing FV, DG, GLS and FS methods which are computationally more efficient while retaining the pleasant theoretical properties achieved by entropy symmetrization. In addition, the task of Jacobian linearization of these schemes for use in Newton's method is greatly simplified owing to exploitation of exact symmetries which exist in the system. These variants have been implemented in the "ELF" library for which example calculations will be shown. The FV, FS and DG schemes also permit discrete maximum principle analysis and enforcement which greatly adds to the robustness of the methods. Some prevalent limiting strategies will be reviewed. Next, we consider embedding these nonlinear space discretizations into exact and inexact Newton solvers which are preconditioned using a nonoverlapping (Schur complement) domain decomposition technique. Elements of nonoverlapping domain decomposition for elliptic problems will be reviewed followed by the present extension to hyperbolic and elliptic-hyperbolic problems. Other issues of practical relevance such the meshing of geometries, code implementation, turbulence modeling, global convergence, etc. will be addressed as needed.

Undesirable Choice Biases with Small Differences in the Spatial Structure of Chance Stimulus Sequences.

PubMed

Herrera, David; Treviño, Mario

2015-01-01

In two-alternative discrimination tasks, experimenters usually randomize the location of the rewarded stimulus so that systematic behavior with respect to irrelevant stimuli can only produce chance performance on the learning curves. One way to achieve this is to use random numbers derived from a discrete binomial distribution to create a 'full random training schedule' (FRS). When using FRS, however, sporadic but long laterally-biased training sequences occur by chance and such 'input biases' are thought to promote the generation of laterally-biased choices (i.e., 'output biases'). As an alternative, a 'Gellerman-like training schedule' (GLS) can be used. It removes most input biases by prohibiting the reward from appearing on the same location for more than three consecutive trials. The sequence of past rewards obtained from choosing a particular discriminative stimulus influences the probability of choosing that same stimulus on subsequent trials. Assuming that the long-term average ratio of choices matches the long-term average ratio of reinforcers, we hypothesized that a reduced amount of input biases in GLS compared to FRS should lead to a reduced production of output biases. We compared the choice patterns produced by a 'Rational Decision Maker' (RDM) in response to computer-generated FRS and GLS training sequences. To create a virtual RDM, we implemented an algorithm that generated choices based on past rewards. Our simulations revealed that, although the GLS presented fewer input biases than the FRS, the virtual RDM produced more output biases with GLS than with FRS under a variety of test conditions. Our results reveal that the statistical and temporal properties of training sequences interacted with the RDM to influence the production of output biases. Thus, discrete changes in the training paradigms did not translate linearly into modifications in the pattern of choices generated by a RDM. Virtual RDMs could be further employed to guide the selection of proper training schedules for perceptual decision-making studies.

Membrane Proteomics of Arabidopsis Glucosinolate Mutants cyp79B2/B3 and myb28/29

PubMed Central

Mostafa, Islam; Yoo, Mi-Jeong; Zhu, Ning; Geng, Sisi; Dufresne, Craig; Abou-Hashem, Maged; El-Domiaty, Maher; Chen, Sixue

2017-01-01

Glucosinolates (Gls) constitute a major group of natural metabolites represented by three major classes (aliphatic, indolic and aromatic) of more than 120 chemical structures. In our previous work, soluble proteins and metabolites in Arabidopsis mutants deficient of aliphatic (myb28/29) and indolic Gls (cyp79B2B3) were analyzed. Here we focus on investigating the changes at the level of membrane proteins in these mutants. Our LC/MS-MS analyses of tandem mass tag (TMT) labeled peptides derived from the cyp79B2/B3 and myb28/29 relative to wild type resulted in the identification of 4,673 proteins, from which 2,171 are membrane proteins. Fold changes and statistical analysis showed 64 increased and 74 decreased in cyp79B2/B3, while 28 increased and 17 decreased in myb28/29. As to the shared protein changes between the mutants, one protein was increased and eight were decreased. Bioinformatics analysis of the changed proteins led to the discovery of three cytochromes in glucosinolate molecular network (GMN): cytochrome P450 86A7 (At1g63710), cytochrome P450 71B26 (At3g26290), and probable cytochrome c (At1g22840). CYP86A7 and CYP71B26 may play a role in hydroxyl-indolic Gls production. In addition, flavone 3′-O-methyltransferase 1 represents an interesting finding as it is likely to participate in the methylation process of the hydroxyl-indolic Gls to form methoxy-indolic Gls. The analysis also revealed additional new nodes in the GMN related to stress and defense activity, transport, photosynthesis, and translation processes. Gene expression and protein levels were found to be correlated in the cyp79B2/B3, but not in the myb28/29. PMID:28443122

Abdominal adiposity, general obesity, and subclinical systolic dysfunction in the elderly: A population-based cohort study.

PubMed

Russo, Cesare; Sera, Fusako; Jin, Zhezhen; Palmieri, Vittorio; Homma, Shunichi; Rundek, Tatjana; Elkind, Mitchell S V; Sacco, Ralph L; Di Tullio, Marco R

2016-05-01

General obesity, measured by body mass index (BMI), and abdominal adiposity, measured as waist circumference (WC) and waist-to-hip ratio (WHR), are associated with heart failure and cardiovascular events. However, the relationship of general and abdominal obesity with subclinical left ventricular (LV) dysfunction is unknown. We assessed the association of general and abdominal obesity with subclinical LV systolic dysfunction in a population-based elderly cohort. Participants from the Cardiovascular Abnormalities and Brain Lesions study underwent measurement of BMI, WC, and WHR. Left ventricular systolic function was assessed by two-dimensional echocardiographic LV ejection fraction (LVEF) and speckle-tracking global longitudinal strain (GLS). The study population included 729 participants (mean age 71 ± 9 years, 60% women). In multivariate analysis, higher BMI (but not WC and WHR) was associated with higher LVEF (β = 0.11, P = 0.003). Higher WC (β = 0.08, P = 0.038) and higher WHR (β = 0.15, P < 0.001) were associated with lower GLS, whereas BMI was not (P = 0.720). Compared with normal WHR, high WHR was associated with lower GLS in all BMI categories (normal, overweight, and obese), and was associated with subclinical LV dysfunction by GLS both in participants without [adjusted odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.6, P = 0.020] and with general obesity (adjusted OR 5.4, 95% CI 1.1-25.9, P = 0.034). WHR was incremental to BMI and risk factors in predicting LV dysfunction. Abdominal adiposity was independently associated with subclinical LV systolic dysfunction by GLS in all BMI categories. BMI was not associated with LV dysfunction. Increased abdominal adiposity may be a risk factor for LV dysfunction regardless of the presence of general obesity. © 2016 The Authors. European Journal of Heart Failure © 2016 European Society of Cardiology.

Left atrial booster pump function is an independent predictor of subsequent life-threatening ventricular arrhythmias in non-ischaemic cardiomyopathy.

PubMed

Negishi, Kazuaki; Negishi, Tomoko; Zardkoohi, Omeed; Ching, Elizabeth A; Basu, Nivedita; Wilkoff, Bruce L; Popović, Zoran B; Marwick, Thomas H

2016-10-01

Left atrial (LA) function helps to preserve cardiac output and to control pulmonary capillary wedge pressure in the setting of left ventricular (LV) impairment, but little is known about the contribution of the LA function to ventricular arrhythmia. We sought whether LA booster pump function was associated with arrhythmias in patients undergoing primary prevention implantable cardioverter-defibrillator (ICD) implantation for non-ischaemic dilated cardiomyopathy (NICM), independent of global longitudinal strain (GLS) and mechanical dispersion (MD). We identified 124 NICM patients (56 ± 13, 67 male) who underwent echocardiography pre-ICD implantation for primary prevention. The main outcome measure was appropriate ICD therapy (anti-tachycardia pacing or shock). The mitral A-wave was used as an LA functional marker. MD was defined as standard deviation of time to peak strain of each segment. Over a median follow-up of 3.8 ± 2.2 years, 36 patients had appropriate ICD therapy, including 23 shocks. Patients with appropriate ICD therapy had lower A-wave velocity (P < 0.001), larger LA volume (P < 0.001), and impaired circumferential MD (P = 0.006), but similar ejection fraction (EF) (P = 0.40) and GLS (P = 0.11). In sequential Cox proportional hazards models, A-wave, E/A ratio, and GLS were significantly associated with outcomes, independent of age, sex, and cardiac resynchronization therapy defibrillator or left bundle branch block. In nested Cox models, mitral A-wave had a prognostic value incremental to models with LV systolic (EF and GLS) and diastolic functional parameters (E/A, E/e', and LA volume) and MD. LA booster pump function was an independent and incremental predictor of arrhythmias in NICM over GLS and MD, and may aid better risk stratification in this population. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Cyclooxygenase inhibitors in preterm infants with patent ductus arteriosus: effects on cardiac and vascular indices.

PubMed

Sehgal, Arvind; Doctor, Tejas; Menahem, Samuel

2014-12-01

Existing data suggest subendocardial ischemia in preterm infants with patent ductus arteriosus (PDA) and alterations in cardiac function after indomethacin administration. This study aimed to explore the evolution of left ventricular function by conventional echocardiography and speckle-tracking echocardiography (STE) and to ascertain the interrelationship with coronary flow indices in response to indomethacin. A prospective observational study was performed with preterm infants receiving indomethacin for medical closure of PDA. Serial echocardiography was performed, and the results were analyzed using analysis of variance. Intra- and interobserver variability was assessed using the intraclass correlation coefficient. Indomethacin was administered to 18 infants born at a median gestational age of 25.8 weeks (interquartile range [IQR], 24.2-28.1 weeks) with a birth weight of 773 g (IQR, 704-1,002 g). The median age of the infants was 7.5 days (IQR, 4-17). Global longitudinal strain (GLS) values significantly decreased immediately after indomethacin infusion (preindomethacin GLS, -19.1 ± 2.4 % vs. -15.9 ± 1.7 %; p < 0.0001) but had improved at reassessment after 1 h (-17.4 ± 1.8 %). Conventional echocardiographic indices did not show significant alterations. A significant increase in arterial resistance in the coronary vasculature from 1.7 to 2.4 mmHg/cm/s was demonstrated. A significant correlation was noted between peak systolic GLS and flow resistance in the coronary vasculature. Significant changes in myocardial indices were observed immediately after indomethacin infusion. Compared with conventional methods, STE is a more sensitive tool to facilitate understanding of hemodynamics in preterm infants.

Global Land Survey Impervious Mapping Project Web Site

NASA Technical Reports Server (NTRS)

DeColstoun, Eric Brown; Phillips, Jacqueline

2014-01-01

The Global Land Survey Impervious Mapping Project (GLS-IMP) aims to produce the first global maps of impervious cover at the 30m spatial resolution of Landsat. The project uses Global Land Survey (GLS) Landsat data as its base but incorporates training data generated from very high resolution commercial satellite data and using a Hierarchical segmentation program called Hseg. The web site contains general project information, a high level description of the science, examples of input and output data, as well as links to other relevant projects.

Linear growth increased in young children in an urban slum of Haiti: a randomized controlled trial of a lipid-based nutrient supplement.

PubMed

Iannotti, Lora L; Dulience, Sherlie Jean Louis; Green, Jamie; Joseph, Saminetha; François, Judith; Anténor, Marie-Lucie; Lesorogol, Carolyn; Mounce, Jacqueline; Nickerson, Nathan M

2014-01-01

Haiti has experienced rapid urbanization that has exacerbated poverty and undernutrition in large slum areas. Stunting affects 1 in 5 young children. We aimed to test the efficacy of a daily lipid-based nutrient supplement (LNS) for increased linear growth in young children. Healthy, singleton infants aged 6-11 mo (n = 589) were recruited from an urban slum of Cap Haitien and randomly assigned to receive: 1) a control; 2) a 3-mo LNS; or 3) a 6-mo LNS. The LNS provided 108 kcal and other nutrients including vitamin A, vitamin B-12, iron, and zinc at ≥80% of the recommended amounts. Infants were followed monthly on growth, morbidity, and developmental outcomes over a 6-mo intervention period and at one additional time point 6 mo postintervention to assess sustained effects. The Bonferroni multiple comparisons test was applied, and generalized least-squares (GLS) regressions with mixed effects was used to examine impacts longitudinally. Baseline characteristics did not differ by trial arm except for a higher mean age in the 6-mo LNS group. GLS modeling showed LNS supplementation for 6 mo significantly increased the length-for-age z score (±SE) by 0.13 ± 0.05 and the weight-for-age z score by 0.12 ± 0.02 compared with in the control group after adjustment for child age (P < 0.001). The effects were sustained 6 mo postintervention. Morbidity and developmental outcomes did not differ by trial arm. A low-energy, fortified product improved the linear growth of young children in this urban setting. The trial was registered at clinicaltrials.gov as NCT01552512.

Influence of cultivar and fertilizer approach on curly kale (Brassica oleracea L. var. sabellica). 1. Genetic diversity reflected in agronomic characteristics and phytochemical concentration.

PubMed

Groenbaek, Marie; Jensen, Sidsel; Neugart, Susanne; Schreiner, Monika; Kidmose, Ulla; Kristensen, Hanne Lakkenborg

2014-11-26

The objectives were to investigate if genetic diversity among field-grown traditional and F1 hybrid kale cultivars was reflected in different agronomic characteristics and consequently glucosinolate (GLS) and flavonoid glycoside concentration. This study evaluated how nitrogen and sulfur supply and biomass allocation modified phytochemicals in two experiments with combinations of three cultivars and four N and two S application levels. Results showed less growth, and higher N concentration in the traditional cultivar 'Tiara' was associated with increased indole and total GLSs compared to traditional 'Høj Amager Toftø' and F1 hybrid 'Reflex' cultivars, which exhibited higher yield, lower N concentration, and different biomass allocation. S application increased total GLS concentration, whereas aliphatic GLS percentage decreased when N application increased. Decrease of six 'Reflex' GLSs besides quercetin glycosides and total flavonoid glycosides with increased N indicated higher N responsiveness for 'Reflex'. In conclusion, differences in agronomic characteristics were reflected in diverse phytochemical composition.

Gastroparesis Updates on Pathogenesis and Management

PubMed Central

Liu, Nanlong; Abell, Thomas

2017-01-01

Gastroparesis (Gp) is a chronic disease that presents with clinical symptoms of early satiety, bloating, nausea, vomiting, and abdominal pain. Along with these symptoms, an objective finding of delayed gastric emptying, along with a documented absence of gastric outlet obstruction, are required for diagnosis. This article focuses on updates in the pathogenesis and management of Gp. Recent studies on full thickness biopsies of Gp patients have shed light on the complex interactions of the central, autonomic, and enteric nervous systems, which all play key roles in maintaining normal gut motility. The management of Gp has evolved beyond prokinetics and antiemetics with the use of gastric electrical stimulators (GES). In addition, this review aims to introduce the concept of gastroparesis-like syndrome (GLS). GLS helps groups of patients who have the cardinal symptoms of Gp but have a normal or rapid emptying test. Recent tests have shown that patients with Gp and GLS have similar pathophysiology, benefit greatly from GES placement, and likely should be treated in a similar manner. PMID:28535580

MYC-induced reprogramming of glutamine catabolism supports optimal virus replication

PubMed Central

Thai, Minh; Thaker, Shivani K.; Feng, Jun; Du, Yushen; Hu, Hailiang; Ting Wu, Ting; Graeber, Thomas G.; Braas, Daniel; Christofk, Heather R.

2015-01-01

Viruses rewire host cell glucose and glutamine metabolism to meet the bioenergetic and biosynthetic demands of viral propagation. However, the mechanism by which viruses reprogram glutamine metabolism and the metabolic fate of glutamine during adenovirus infection have remained elusive. Here, we show MYC activation is necessary for adenovirus-induced upregulation of host cell glutamine utilization and increased expression of glutamine transporters and glutamine catabolism enzymes. Adenovirus-induced MYC activation promotes increased glutamine uptake, increased use of glutamine in reductive carboxylation and increased use of glutamine in generating hexosamine pathway intermediates and specific amino acids. We identify glutaminase (GLS) as a critical enzyme for optimal adenovirus replication and demonstrate that GLS inhibition decreases replication of adenovirus, herpes simplex virus 1 and influenza A in cultured primary cells. Our findings show that adenovirus-induced reprogramming of glutamine metabolism through MYC activation promotes optimal progeny virion generation, and suggest that GLS inhibitors may be useful therapeutically to reduce replication of diverse viruses. PMID:26561297

Pyruvate carboxylase is critical for non–small-cell lung cancer proliferation

PubMed Central

Sellers, Katherine; Fox, Matthew P.; Bousamra, Michael; Slone, Stephen P.; Higashi, Richard M.; Miller, Donald M.; Wang, Yali; Yan, Jun; Yuneva, Mariia O.; Deshpande, Rahul; Lane, Andrew N.; Fan, Teresa W.-M.

2015-01-01

Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non–small-cell lung cancer (NSCLC) with uniformly 13C-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in 13C6-glucose or 13C5,15N2-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation. PMID:25607840

Fourth - generation languages. Volume 2. Representative 4GLs

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

Martin, J.

1986-01-01

The chapters in Part II each describe one representative product marketed by a vendor other than IBM. (Volume III of this work covers IBM languages.) The chapters in Part II cover the following 4GLs: ADS/ONLINE, APPLICATION FACTORY, DATATRIEVE, FOCUS, IDEAL, INTELLECT, MANTIS, MIMER, NATURAL, NOMAD2, RAMIS II, SYSTEM W, and USE-IT. The Perspective section of Part II presents a general overview of the product and describes its role in the marketplace. The Tutorial section describes how a user employs the language in application development.

Prospective comparison of speckle tracking longitudinal bidimensional strain between two vendors.

PubMed

Castel, Anne-Laure; Szymanski, Catherine; Delelis, François; Levy, Franck; Menet, Aymeric; Mailliet, Amandine; Marotte, Nathalie; Graux, Pierre; Tribouilloy, Christophe; Maréchaux, Sylvestre

2014-02-01

Speckle tracking is a relatively new, largely angle-independent technique used for the evaluation of myocardial longitudinal strain (LS). However, significant differences have been reported between LS values obtained by speckle tracking with the first generation of software products. To compare LS values obtained with the most recently released equipment from two manufacturers. Systematic scanning with head-to-head acquisition with no modification of the patient's position was performed in 64 patients with equipment from two different manufacturers, with subsequent off-line post-processing for speckle tracking LS assessment (Philips QLAB 9.0 and General Electric [GE] EchoPAC BT12). The interobserver variability of each software product was tested on a randomly selected set of 20 echocardiograms from the study population. GE and Philips interobserver coefficients of variation (CVs) for global LS (GLS) were 6.63% and 5.87%, respectively, indicating good reproducibility. Reproducibility was very variable for regional and segmental LS values, with CVs ranging from 7.58% to 49.21% with both software products. The concordance correlation coefficient (CCC) between GLS values was high at 0.95, indicating substantial agreement between the two methods. While good agreement was observed between midwall and apical regional strains with the two software products, basal regional strains were poorly correlated. The agreement between the two software products at a segmental level was very variable; the highest correlation was obtained for the apical cap (CCC 0.90) and the poorest for basal segments (CCC range 0.31-0.56). A high level of agreement and reproducibility for global but not for basal regional or segmental LS was found with two vendor-dependent software products. This finding may help to reinforce clinical acceptance of GLS in everyday clinical practice. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Early detection of cardiac involvement in sarcoidosis with 2-dimensional speckle-tracking echocardiography.

PubMed

Schouver, Elie-Dan; Moceri, Pamela; Doyen, Denis; Tieulie, Nathalie; Queyrel, Viviane; Baudouy, Delphine; Cerboni, Pierre; Gibelin, Pierre; Leroy, Sylvie; Fuzibet, Jean-Gabriel; Ferrari, Emile

2017-01-15

Cardiac sarcoidosis (CS) is associated with high morbidity and sudden death. The absence of specific symptoms and lack of diagnostic gold standard technique is challenging. New imaging methods could improve the diagnosis of CS. The aim of our study was to assess the role of left ventricular (LV) longitudinal and circumferential strain as estimated by 2D speckle-tracking imaging in patients with diagnosed sarcoidosis without cardiac involvement according to the current guidelines. We investigated the prevalence of LV strain impairment in this population and assessed its relationship with clinical outcomes, composite of mortality, heart failure, arrhythmia and/or secondarily development of CS and cardiac device implantation. We performed a prospective case-control longitudinal study including 35 patients with diagnosed sarcoidosis and normal cardiac function as assessed by standard transthoracic echocardiography and 35 healthy age- and gender-matched controls. All patients underwent a comprehensive echocardiographic study. Mean age of patients was 47.9±14.8years old (22 women). Compared with controls, global LV longitudinal strain (LV GLS) was reduced in sarcoidosis patients: (-17.2±3.1 vs -21.3±1.5%, p<0.0001). Circumferential LV strain was preserved in patients compared to controls (-19.9±-4.3% vs -21.3±1.5%, p=0.12). Impaired LV GLS was significantly associated with clinical outcomes (HR 1.56; [1.16-2.11], p<0.01) on univariate analysis. Speckle-tracking echocardiography revealed decreased longitudinal LV strain in sarcoidosis patients that was associated with outcomes. LV GLS may represent an early marker of myocardial involvement in sarcoidosis patients that needs to be studied further. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A regression-kriging model for estimation of rainfall in the Laohahe basin

NASA Astrophysics Data System (ADS)

Wang, Hong; Ren, Li L.; Liu, Gao H.

2009-10-01

This paper presents a multivariate geostatistical algorithm called regression-kriging (RK) for predicting the spatial distribution of rainfall by incorporating five topographic/geographic factors of latitude, longitude, altitude, slope and aspect. The technique is illustrated using rainfall data collected at 52 rain gauges from the Laohahe basis in northeast China during 1986-2005 . Rainfall data from 44 stations were selected for modeling and the remaining 8 stations were used for model validation. To eliminate multicollinearity, the five explanatory factors were first transformed using factor analysis with three Principal Components (PCs) extracted. The rainfall data were then fitted using step-wise regression and residuals interpolated using SK. The regression coefficients were estimated by generalized least squares (GLS), which takes the spatial heteroskedasticity between rainfall and PCs into account. Finally, the rainfall prediction based on RK was compared with that predicted from ordinary kriging (OK) and ordinary least squares (OLS) multiple regression (MR). For correlated topographic factors are taken into account, RK improves the efficiency of predictions. RK achieved a lower relative root mean square error (RMSE) (44.67%) than MR (49.23%) and OK (73.60%) and a lower bias than MR and OK (23.82 versus 30.89 and 32.15 mm) for annual rainfall. It is much more effective for the wet season than for the dry season. RK is suitable for estimation of rainfall in areas where there are no stations nearby and where topography has a major influence on rainfall.

Intervendor consistency and reproducibility of left ventricular 2D global and regional strain with two different high-end ultrasound systems.

PubMed

Shiino, Kenji; Yamada, Akira; Ischenko, Matthew; Khandheria, Bijoy K; Hudaverdi, Mahala; Speranza, Vicki; Harten, Mary; Benjamin, Anthony; Hamilton-Craig, Christian R; Platts, David G; Burstow, Darryl J; Scalia, Gregory M; Chan, Jonathan

2017-06-01

We aimed to assess intervendor agreement of global (GLS) and regional longitudinal strain by vendor-specific software after EACVI/ASE Industry Task Force Standardization Initiatives for Deformation Imaging. Fifty-five patients underwent prospective dataset acquisitions on the same day by the same operator using two commercially available cardiac ultrasound systems (GE Vivid E9 and Philips iE33). GLS and regional peak longitudinal strain were analyzed offline using corresponding vendor-specific software (EchoPAC BT13 and QLAB version 10.3). Absolute mean GLS measurements were similar between the two vendors (GE -17.5 ± 5.2% vs. Philips -18.9 ± 5.1%, P = 0.15). There was excellent intervendor correlation of GLS by the same observer [r = 0.94, P < 0.0001; bias -1.3%, 95% CI limits of agreement (LOA) -4.8 to 2.2%). Intervendor comparison for regional longitudinal strain by coronary artery territories distribution were: LAD: r = 0.85, P < 0.0001; bias 0.5%, LOA -5.3 to 6.4%; RCA: r = 0.88, P < 0.0001; bias -2.4%, LOA -8.6 to 3.7%; LCX: r = 0.76, P < 0.0001; bias -5.3%, LOA -10.6 to 2.0%. Intervendor comparison for regional longitudinal strain by LV levels were: basal: r = 0.86, P < 0.0001; bias -3.6%, LOA -9.9 to 2.0%; mid: r = 0.90, P < 0.0001; bias -2.6%, LOA -7.8 to 2.6%; apical: r = 0.74; P < 0.0001; bias -1.3%, LOA -9.4 to 6.8%. Intervendor agreement in GLS and regional strain measurements have significantly improved after the EACVI/ASE Task Force Strain Standardization Initiatives. However, significant wide LOA still exist, especially for regional strain measurements, which remains relevant when considering vendor-specific software for serial measurements. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

The effect of exercise training on biventricular myocardial strain in heart failure with preserved ejection fraction.

PubMed

Angadi, Siddhartha S; Jarrett, Catherine L; Sherif, Moustafa; Gaesser, Glenn A; Mookadam, Farouk

2017-08-01

High-intensity interval training (HIIT) improves peak oxygen uptake and left ventricular diastology in patients with heart failure with preserved ejection fraction (HFpEF). However, its effects on myocardial strain in HFpEF remain unknown. We explored the effects of HIIT and moderate-intensity aerobic continuous training (MI-ACT) on left and right ventricular strain parameters in patients with HFpEF. Furthermore, we explored their relationship with peak oxygen uptake (VO 2peak ). Fifteen patients with HFpEF (age = 70 ± 8.3 years) were randomized to either: (i) HIIT (4 × 4 min, 85-90% peak heart rate, interspersed with 3 min of active recovery; n = 9) or (ii) MI-ACT (30 min at 70% peak heart rate; n = 6). Patients were trained 3 days/week for 4 weeks and underwent VO 2peak testing and 2D echocardiography at baseline and after completion of the 12 sessions of supervised exercise training. Left ventricular (LV) and right ventricular (RV) average global peak systolic longitudinal strain (GLS) and peak systolic longitudinal strain rate (GSR) were quantified. Paired t-tests were used to examine within-group differences and unpaired t-tests used for between-group differences (α = 0.05). Right ventricular average global peak systolic longitudinal strain improved significantly in the HIIT group after training (pre = -18.4 ± 3.2%, post = -21.4 ± 1.7%; P = 0.02) while RV-GSR, LV-GLS, and LV-GSR did not (P > 0.2). No significant improvements were observed following MI-ACT. No significant between-group differences were observed for any strain measure. ΔLV-GLS and ΔRV-GLS were modestly correlated with ΔVO 2peak (r = -0.48 and r = -0.45; P = 0.1, respectively). In patients with HFpEF, 4 weeks of HIIT significantly improved RV-GLS. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

T1 Mapping by Cardiac Magnetic Resonance and Multidimensional Speckle-Tracking Strain by Echocardiography for the Detection of Acute Cellular Rejection in Cardiac Allograft Recipients.

PubMed

Sade, Leyla Elif; Hazirolan, Tuncay; Kozan, Hatice; Ozdemir, Handan; Hayran, Mutlu; Eroglu, Serpil; Pirat, Bahar; Sezgin, Atilla; Muderrisoglu, Haldun

2018-04-14

The aim of this study was to test the hypothesis that echocardiographic strain imaging, by tracking subtle alterations in myocardial function, and cardiac magnetic resonance T1 mapping, by quantifying tissue properties, are useful and complement each other to detect acute cellular rejection in heart transplant recipients. Noninvasive alternatives to endomyocardial biopsy are highly desirable to monitor acute cellular rejection. Surveillance endomyocardial biopsies, catheterizations, and echocardiograms performed serially according to institutional protocol since transplantation were retrospectively reviewed. Sixteen-segment global longitudinal strain (GLS) and circumferential strain were measured before, during, and after the first rejection and at 2 time points for patients without rejection using Velocity Vector Imaging for the first part of the study. The second part, with cardiac magnetic resonance added to the protocol, served to validate previously derived strain cutoffs, examine the progression of strain over time, and to determine the accuracy of strain and T1 measurements to define acute cellular rejection. All tests were performed within 48 h. Median time to first rejection (16 grade 1 rejection, 15 grade ≥2 rejection) was 3 months (interquartile range: 3 to 36 months) in 49 patients. GLS and global circumferential strain worsened significantly during grade 1 rejection and ≥2 rejection and were independent predictors of any rejection. In the second part of the study, T1 time ≥1,090 ms, extracellular volume ≥32%, GLS >-14%, and global circumferential strain ≥-24% had 100% sensitivity and 100% negative predictive value to define grade ≥2 rejection with 70%, 63%, 55%, and 35% positive predictive values, respectively. The combination of GLS >-16% and T1 time ≥1,060 ms defined grade 1 rejection with 91% sensitivity and 92% negative predictive value. After successful treatment, T1 times decreased significantly. T1 mapping and echocardiographic GLS can serve to guide endomyocardial biopsy selectively. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Infection Structure–Specific Expression of β-1,3-Glucan Synthase Is Essential for Pathogenicity of Colletotrichum graminicola and Evasion of β-Glucan–Triggered Immunity in Maize[W

PubMed Central

Oliveira-Garcia, Ely; Deising, Holger B.

2013-01-01

β-1,3-Glucan and chitin are the most prominent polysaccharides of the fungal cell wall. Covalently linked, these polymers form a scaffold that determines the form and properties of vegetative and pathogenic hyphae. While the role of chitin in plant infection is well understood, the role of β-1,3-glucan is unknown. We functionally characterized the β-1,3-glucan synthase gene GLS1 of the maize (Zea mays) pathogen Colletotrichum graminicola, employing RNA interference (RNAi), GLS1 overexpression, live-cell imaging, and aniline blue fluorochrome staining. This hemibiotroph sequentially differentiates a melanized appressorium on the cuticle and biotrophic and necrotrophic hyphae in its host. Massive β-1,3-glucan contents were detected in cell walls of appressoria and necrotrophic hyphae. Unexpectedly, GLS1 expression and β-1,3-glucan contents were drastically reduced during biotrophic development. In appressoria of RNAi strains, downregulation of β-1,3-glucan synthesis increased cell wall elasticity, and the appressoria exploded. While the shape of biotrophic hyphae was unaffected in RNAi strains, necrotrophic hyphae showed severe distortions. Constitutive expression of GLS1 led to exposure of β-1,3-glucan on biotrophic hyphae, massive induction of broad-spectrum defense responses, and significantly reduced disease symptom severity. Thus, while β-1,3-glucan synthesis is required for cell wall rigidity in appressoria and fast-growing necrotrophic hyphae, its rigorous downregulation during biotrophic development represents a strategy for evading β-glucan–triggered immunity. PMID:23898035

Comparison of bioactive phytochemical content and release of isothiocyanates in selected brassica sprouts.

PubMed

De Nicola, Gina Rosalinda; Bagatta, Manuela; Pagnotta, Eleonora; Angelino, Donato; Gennari, Lorenzo; Ninfali, Paolino; Rollin, Patrick; Iori, Renato

2013-11-01

The consumption of brassica sprouts as raw vegetables provides a fair amount of glucosinolates (GLs) and active plant myrosinase, which enables the breakdown of GLs into health-promoting isothiocyanates (ITCs). This study reports the determination of the main constituents related to human health found in edible sprouts of two Brassica oleracea varieties, broccoli and Tuscan black kale, and two Raphanus sativus varieties, Daikon and Sango. Radish sprouts exhibited the highest ability to produce ITCs, with Daikon showing the greatest level of conversion of GLs into bioactive ITCs (96.5%), followed by Sango (90.0%). Tuscan black kale gave a value of 68.5%, whereas broccoli displayed the lowest with 18.7%. ITCs were not the exclusive GL breakdown products in the two B. oleracea varieties, since nitriles were also produced, thus accounting for the lower conversion observed. Measuring the release of plant ITCs is a valuable tool in predicting the potential level of exposure to these bioactive compounds after the consumption of raw brassica sprouts. Copyright © 2013 Elsevier Ltd. All rights reserved.

Investigation of glucosinolate profile and qualitative aspects in sprouts and roots of horseradish (Armoracia rusticana) using LC-ESI-hybrid linear ion trap with Fourier transform ion cyclotron resonance mass spectrometry and infrared multiphoton dissociation.

PubMed

Agneta, Rosa; Rivelli, Anna Rita; Ventrella, Emanuela; Lelario, Filomena; Sarli, Giulio; Bufo, Sabino Aurelio

2012-08-01

Within the family of Brassicaceae, an important source of glucosinolates (GLSs) is represented by horseradish ( Armoracia rusticana P. Gaertner, B. Meyer & Scherbius), cultivated for its roots, which are grated fresh or processed into a sauce and used as a condiment. The characteristic pungent flavor of the root depends on the abundance of the bioactive GLS molecules. In crude plant extracts (sprouts and roots) of an accession of horseradish largely diffused in the Basilicata region (southern Italy), which develops many sprouts and produces white, fiery, and sharp-flavored marketable roots, we characterized the GLS profile by LC-ESI-LTQ-FTICR-MS and IRMPD. In sprouts and roots we identified 16 and 11 GLSs, respectively. We confirmed the presence of sinigrin, 4-hydroxyglucobrassicin, glucobrassicin, gluconasturtin, and 4-methoxyglucobrassicin and identified glucoiberin, gluconapin, glucocochlearin, glucoconringianin, glucosativin, glucoibarin, 5-hydroxyglucobrassicin, glucocapparilinearisin or glucobrassicanapin, glucotropaeolin, and glucoarabishirsutain, not previously characterized in horseradish. Of particular note was the presence of the putative 2-methylsulfonyl-oxo-ethyl-GLS.

Large Area Scene Selection Interface (LASSI). Methodology of Selecting Landsat Imagery for the Global Land Survey 2005

NASA Technical Reports Server (NTRS)

Franks, Shannon; Masek, Jeffrey G.; Headley, Rachel M.; Gasch, John; Arvidson, Terry

2009-01-01

The Global Land Survey (GLS) 2005 is a cloud-free, orthorectified collection of Landsat imagery acquired during the 2004-2007 epoch intended to support global land-cover and ecological monitoring. Due to the numerous complexities in selecting imagery for the GLS2005, NASA and the U.S. Geological Survey (USGS) sponsored the development of an automated scene selection tool, the Large Area Scene Selection Interface (LASSI), to aid in the selection of imagery for this data set. This innovative approach to scene selection applied a user-defined weighting system to various scene parameters: image cloud cover, image vegetation greenness, choice of sensor, and the ability of the Landsat 7 Scan Line Corrector (SLC)-off pair to completely fill image gaps, among others. The parameters considered in scene selection were weighted according to their relative importance to the data set, along with the algorithm's sensitivity to that weight. This paper describes the methodology and analysis that established the parameter weighting strategy, as well as the post-screening processes used in selecting the optimal data set for GLS2005.

Fixative Composition Alters Distributions of Immunoreactivity for Glutaminase and Two Markers of Nociceptive Neurons, Nav1.8 and TRPV1, in the Rat Dorsal Root Ganglion

PubMed Central

Hoffman, E. Matthew; Schechter, Ruben; Miller, Kenneth E.

2010-01-01

Most, if not all, dorsal root ganglion (DRG) neurons use the neurotransmitter glutamate. There are, however, conflicting reports of the percentages of DRG neurons that express glutaminase (GLS), the enzyme that synthesizes glutamate, ranging from 30% to 100% of DRG neurons. Defining DRG neuron populations by the expression of proteins like GLS, which indicates function, is routinely accomplished with immunolabeling techniques. Proper characterization of DRG neuron populations relies on accurate detection of such antigens. It is known intuitively that fixation can alter immunoreactivity (IR). In this study, we compared the effects of five formaldehyde concentrations between 0.25% and 4.0% (w/v) and five picric acid concentrations between 0.0% and 0.8% (w/v) on the IR of GLS, the voltage-gated sodium channel 1.8 (Nav1.8), and the capsaicin receptor TRPV1. We also compared the effects of five incubation time lengths from 2 to 192 hr, in primary antiserum on IR. Lowering formaldehyde concentration elevated IR for all three antigens, while raising picric acid concentration increased Nav1.8 and TRPV1 IR. Increasing IR improved detection sensitivity, which led to higher percentages of labeled DRG neurons. By selecting fixation conditions that optimized IR, we found that all DRG neurons express GLS, 69% of neurons express Nav1.8, and 77% of neurons express TRPV1, indicating that some previous studies may have underestimated the percentages of DRG neurons expressing these proteins. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials. (J Histochem Cytochem 58:329–344, 2010) PMID:20026672

New insights into the characterization of Colletotrichum species associated with apple diseases in southern Brazil and Uruguay.

PubMed

Velho, Aline Cristina; Alaniz, Sandra; Casanova, Leticia; Mondino, Pedro; Stadnik, Marciel J

2015-04-01

Colletotrichum species are associated with Apple bitter rot (ABR) and Glomerella leaf spot (GLS). Whereas both apple diseases occur frequently in Brazil, only the former has been reported in Uruguay. This work was aimed at identifying and comparing morpho-cultural characteristics and pathogenic variability of thirty-nine Colletotrichum isolates from both countries. Sequencing of the internal transcribed spacer (ITS) rDNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β-tubulin (TUB2) allowed the identification of three species causing ABR and GLS in Brazil, i.e., Colletotrichum fructicola, Colletotrichum karstii, and Colletotrichum nymphaeae; and three species causing ABR in Uruguay, i.e., C. fructicola, Colletotrichum theobromicola, and Colletotrichum melonis. Six groups of colony colours were recorded with group 1 (mycelium white to pink and in reverse pinkish) and group 2 (mycelium white to grey and in reverse pinkish) the most frequent. Isolates of C. fructicola and C. theobromicola were sensitive to benomyl, while C. karstii, C. nymphaeae, and C. melonis were resistant. Conidia were predominantly cylindrical for C. fructicola and C. karstii, fusiform for C. nymphaeae and C. melonis, and obclavate for C. theobromicola. Brazilian isolates caused ABR in wounded fruits, but only five in non-wounded ones. Uruguayan isolates produced symptoms in fruits with or without previous wounding. All Brazilian isolates from GLS and twelve from ABR were able to cause GLS symptoms, while a sole Uruguayan ABR-isolate caused leaf spot symptoms. This study gives a better insight on the new species causing apple disease in both countries and discusses their pathogenic potential. Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Targeting hepatic glutaminase activity to ameliorate hyperglycemia.

PubMed

Miller, Russell A; Shi, Yuji; Lu, Wenyun; Pirman, David A; Jatkar, Aditi; Blatnik, Matthew; Wu, Hong; Cárdenas, César; Wan, Min; Foskett, J Kevin; Park, Junyoung O; Zhang, Yiyi; Holland, William L; Rabinowitz, Joshua D; Birnbaum, Morris J

2018-05-01

Glucagon levels increase under homeostatic, fasting conditions, promoting the release of glucose from the liver by accelerating the breakdown of glycogen (also known as glycogenolysis). Glucagon also enhances gluconeogenic flux, including from an increase in the hepatic consumption of amino acids. In type 2 diabetes, dysregulated glucagon signaling contributes to the elevated hepatic glucose output and fasting hyperglycemia that occur in this condition. Yet, the mechanism by which glucagon stimulates gluconeogenesis remains incompletely understood. Contrary to the prevailing belief that glucagon acts primarily on cytoplasmic and nuclear targets, we find glucagon-dependent stimulation of mitochondrial anaplerotic flux from glutamine that increases the contribution of this amino acid to the carbons of glucose generated during gluconeogenesis. This enhanced glucose production is dependent on protein kinase A (PKA) and is associated with glucagon-stimulated calcium release from the endoplasmic reticulum, activation of mitochondrial α-ketoglutarate dehydrogenase, and increased glutaminolysis. Mice with reduced levels of hepatic glutaminase 2 (GLS2), the enzyme that catalyzes the first step in glutamine metabolism, show lower glucagon-stimulated glutamine-to-glucose flux in vivo, and GLS2 knockout results in higher fasting plasma glucagon and glutamine levels with lower fasting blood glucose levels in insulin-resistant conditions. As found in genome-wide association studies (GWAS), human genetic variation in the region of GLS2 is associated with higher fasting plasma glucose; here we show in human cryopreserved primary hepatocytes in vitro that these natural gain-of-function missense mutations in GLS2 result in higher glutaminolysis and glucose production. These data emphasize the importance of gluconeogenesis from glutamine, particularly in pathological states of increased glucagon signaling, while suggesting a possible new therapeutic avenue to treat hyperglycemia.

Thermodynamic performance of multi-stage gradational lead screw vacuum pump

NASA Astrophysics Data System (ADS)

Zhao, Fan; Zhang, Shiwei; Sun, Kun; Zhang, Zhijun

2018-02-01

As a kind of dry mechanical vacuum pump, the twin-screw vacuum pump has an outstanding pumping performance during operation, widely used in the semiconductor industry. Compared with the constant lead screw (CLS) vacuum pump, the gradational lead screw (GLS) vacuum pump is more popularly applied in recent years. Nevertheless, not many comparative studies on the thermodynamic performance of GLS vacuum pump can be found in the literature. Our study focuses on one type of GLS vacuum pump, the multi-stage gradational lead screw (MGLS) vacuum pump, gives a detailed description of its construction and illustrates it with the drawing. Based on the structural analysis, the thermodynamic procedure is divided into four distinctive processes, including sucking process, transferring (compressing) process, backlashing process and exhausting process. The internal mechanism of each process is qualitatively illustrated and the mathematical expressions of seven thermodynamic parameters are given under the ideal situation. The performance curves of MGLS vacuum pump are plotted by MATLAB software and compared with those of the CLS vacuum pump in the same case. The results can well explain why the MGLS vacuum pump has more favorable pumping performance than the CLS vacuum pump in saving energy, reducing noise and heat dissipation.

PDHA1 gene knockout in prostate cancer cells results in metabolic reprogramming towards greater glutamine dependence

PubMed Central

Li, Yaqing; Li, Xiaoran; Li, Xiaoli; Zhong, Yali; Ji, Yasai; Yu, Dandan; Zhang, Mingzhi; Wen, Jian-Guo; Zhang, Hongquan; Goscinski, Mariusz Adam; Nesland, Jahn M.; Suo, Zhenhe

2016-01-01

Alternative pathways of metabolism endowed cancer cells with metabolic stress. Inhibiting the related compensatory pathways might achieve synergistic anticancer results. This study demonstrated that pyruvate dehydrogenase E1α gene knockout (PDHA1 KO) resulted in alterations in tumor cell metabolism by rendering the cells with increased expression of glutaminase1 (GLS1) and glutamate dehydrogenase1 (GLUD1), leading to an increase in glutamine-dependent cell survival. Deprivation of glutamine induced cell growth inhibition, increased reactive oxygen species and decreased ATP production. Pharmacological blockade of the glutaminolysis pathway resulted in massive tumor cells apoptosis and dysfunction of ROS scavenge in the LNCaP PDHA1 KO cells. Further examination of the key glutaminolysis enzymes in human prostate cancer samples also revealed that higher levels of GLS1 and GLUD1 expression were significantly associated with aggressive clinicopathological features and poor clinical outcome. These insights supply evidence that glutaminolysis plays a compensatory role for cell survival upon alternative energy metabolism and targeting the glutamine anaplerosis of energy metabolism via GLS1 and GLUD1 in cancer cells may offer a potential novel therapeutic strategy. PMID:27462778

Identification of the glutaminase genes of Aspergillus sojae involved in glutamate production during soy sauce fermentation.

PubMed

Ito, Kotaro; Koyama, Yasuji; Hanya, Yoshiki

2013-01-01

Glutaminase, an enzyme that catalyzes the conversion of L-glutamine to L-glutamate, enhances the umami taste in soy sauce. The Aspergillus sojae genome contains 10 glutaminase genes. In this study, we estimated that approximately 60% of the glutamate in soy sauce is produced through the glutaminase reaction. To determine which glutaminase is involved in soy sauce glutamate production, we prepared soy sauces using single and multiple glutaminase gene disruptants of A. sojae. The glutamate concentration in soy sauce prepared using the ΔgahA-ΔgahB-ΔggtA-Δgls disruptant was approximately 60% lower than that in the control strain, whereas it was decreased by approximately 20-30% in the ΔgahA-ΔgahB disruptant. However, the glutamate concentration was unchanged in the soy sauces prepared using the ΔgahA-ΔggtA-Δgls and ΔgahB-ΔggtA-Δgls disruptants. These results indicate that four glutaminases are involved in glutamate production in soy sauce, and that the peptidoglutaminase activities of GahA and GahB increase the glutamate concentration in soy sauce.

Effect of genomics-related literacy on non-communicable diseases.

PubMed

Nakamura, Sho; Narimatsu, Hiroto; Katayama, Kayoko; Sho, Ri; Yoshioka, Takashi; Fukao, Akira; Kayama, Takamasa

2017-09-01

Recent progress in genomic research has raised expectations for the development of personalized preventive medicine, although genomics-related literacy of patients will be essential. Thus, enhancing genomics-related literacy is crucial, particularly for individuals with low genomics-related literacy because they might otherwise miss the opportunity to receive personalized preventive care. This should be especially emphasized when a lack of genomics-related literacy is associated with elevated disease risk, because patients could therefore be deprived of the added benefits of preventive interventions; however, whether such an association exists is unclear. Association between genomics-related literacy, calculated as the genomics literacy score (GLS), and the prevalence of non-communicable diseases was assessed using propensity score matching on 4646 participants (males: 1891; 40.7%). Notably, the low-GLS group (score below median) presented a higher risk of hypertension (relative risk (RR) 1.09, 95% confidence interval (CI) 1.03-1.16) and obesity (RR 1.11, 95% CI 1.01-1.22) than the high-GLS group. Our results suggest that a low level of genomics-related literacy could represent a risk factor for hypertension and obesity. Evaluating genomics-related literacy could be used to identify a more appropriate population for health and educational interventions.

Diagnosis of Nonischemic Stage B Heart Failure in Type 2 Diabetes Mellitus: Optimal Parameters for Prediction of Heart Failure.

PubMed

Wang, Ying; Yang, Hong; Huynh, Quan; Nolan, Mark; Negishi, Kazuaki; Marwick, Thomas H

2018-05-11

This study sought to identify whether impaired global longitudinal strain (GLS), diastolic dysfunction (DD), or left atrial enlargement (LAE) should be added to stage B heart failure (SBHF) criteria in asymptomatic patients with type 2 diabetes mellitus. SBHF is a precursor to clinical heart failure (HF), and its recognition justifies initiation of cardioprotective therapy. However, original definitions of SBHF were based on LV hypertrophy and impaired ejection fraction. Patients with asymptomatic type 2 diabetes mellitus ≥65 years-of-age (age 71 ± 4 years; 55% men) with preserved ejection fraction and no ischemic heart disease were recruited from a community-based population. All underwent a standard clinical evaluation, and a comprehensive echocardiogram, including assessment of left ventricular hypertrophy (LVH), LAE, DD (abnormal E/e'), and GLS (<16%). Over a median follow-up of 1.5 years (range 0.5 to 3), 20 patients were lost to follow-up, and 290 individuals were entered into the final analyses. In this asymptomatic group, LV dysfunction was identified in 30 (10%) by DD, 68 (23%) by LVH, 102 (35%) by LAE, and 68 (23%) by impaired GLS. New-onset HF developed in 45 patients and 4 died, giving an event rate of 112/1,000 person-years. Survival free of the composite endpoint (HF and death) was about 1.5-fold higher in patients without a normal, compared with an abnormal echocardiogram. LVH, LAE, and GLS <16% were associated with increased risk of the composite endpoint, independent of ARIC risk score and glycosylated hemoglobin, but abnormal E/e' was not. The addition of left atrial volume and GLS provided incremental value to the current standard of clinical risk (ARIC score) and LVH. In a competing-risks regression analysis, LVH (hazard ratio: 2.90; p < 0.001) and GLS <16% (hazard ratio: 2.26; p = 0.008), but not DD and LAE were associated with incident HF. Subclinical left ventricular systolic dysfunction is prevalent in asymptomatic elderly patients with type 2 diabetes mellitus, and impaired GLS is independent and incremental to LVH in the prediction of incident HF. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Mapping Impervious Surfaces Globally at 30m Resolution Using Global Land Survey Data

NASA Technical Reports Server (NTRS)

DeColstoun, Eric Brown; Huang, Chengquan; Tan, Bin; Smith, Sarah Elizabeth; Phillips, Jacqueline; Wang, Panshi; Ling, Pui-Yu; Zhan, James; Li, Sike; Taylor, Michael P.;

Mapping Impervious Surfaces Globally at 30m Resolution Using Landsat Global Land Survey Data

NASA Astrophysics Data System (ADS)

Brown de Colstoun, E.; Huang, C.; Wolfe, R. E.; Tan, B.; Tilton, J.; Smith, S.; Phillips, J.; Wang, P.; Ling, P.; Zhan, J.; Xu, X.; Taylor, M. P.

2013-12-01

Impervious surfaces, mainly artificial structures and roads, cover less than 1% of the world's land surface (1.3% over USA). Regardless of the relatively small coverage, impervious surfaces have a significant impact on the environment. They are the main source of the urban heat island effect, and affect not only the energy balance, but also hydrology and carbon cycling, and both land and aquatic ecosystem services. In the last several decades, the pace of converting natural land surface to impervious surfaces has increased. Quantitatively monitoring the growth of impervious surface expansion and associated urbanization has become a priority topic across both the physical and social sciences. The recent availability of consistent, global scale data sets at 30m resolution such as the Global Land Survey from the Landsat satellites provides an unprecedented opportunity to map global impervious cover and urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such a buildings, roads and parking lots. With long term GLS data now available for the 1975, 1990, 2000, 2005 and 2010 time periods, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. In the Global Land Survey - Imperviousness Mapping Project (GLS-IMP), we are producing the first global 30 m spatial resolution impervious cover data set. We have processed the GLS 2010 data set to surface reflectance (8500+ TM and ETM+ scenes) and are using a supervised classification method using a regression tree to produce continental scale impervious cover data sets. A very large set of accurate training samples is the key to the supervised classifications and is being derived through the interpretation of high spatial resolution (~2 m or less) commercial satellite data (Quickbird and Worldview2) available to us through the unclassified archive of the National Geospatial Intelligence Agency (NGA). For each continental area several million training pixels are derived by analysts using image segmentation algorithms and tools and then aggregated to the 30m resolution of Landsat. Here we will discuss the production/testing of this massive data set for Europe, North and South America and Africa, including assessments of the 2010 surface reflectance data. This type of analysis is only possible because of the availability of long term 30m data sets from GLS and shows much promise for integration of Landsat 8 data in the future.

A Portuguese value set for the SF-6D.

PubMed

Ferreira, Lara N; Ferreira, Pedro L; Pereira, Luis N; Brazier, John; Rowen, Donna

2010-08-01

The SF-6D is a preference-based measure of health derived from the SF-36 that can be used for cost-effectiveness analysis using cost-per-quality adjusted life-year analysis. This study seeks to estimate a system weight for the SF-6D for Portugal and to compare the results with the UK system weights. A sample of 55 health states defined by the SF-6D has been valued by a representative random sample of the Portuguese population, stratified by sex and age (n = 140), using the Standard Gamble (SG). Several models are estimated at both the individual and aggregate levels for predicting health-state valuations. Models with main effects, with interaction effects and with the constant forced to unity are presented. Random effects (RE) models are estimated using generalized least squares (GLS) regressions. Generalized estimation equations (GEE) are used to estimate RE models with the constant forced to unity. Estimations at the individual level were performed using 630 health-state valuations. Alternative functional forms are considered to account for the skewed distribution of health-state valuations. The models are analyzed in terms of their coefficients, overall fit, and the ability for predicting the SG-values. The RE models estimated using GLS and through GEE produce significant coefficients, which are robust across model specification. However, there are concerns regarding some inconsistent estimates, and so parsimonious consistent models were estimated. There is evidence of under prediction in some states assigned to poor health. The results are consistent with the UK results. The models estimated provide preference-based quality of life weights for the Portuguese population when health status data have been collected using the SF-36. Although the sample was randomly drowned findings should be treated with caution, given the small sample size, even knowing that they have been estimated at the individual level.

A locally conservative non-negative finite element formulation for anisotropic advective-diffusive-reactive systems

NASA Astrophysics Data System (ADS)

Mudunuru, M. K.; Shabouei, M.; Nakshatrala, K.

2015-12-01

Advection-diffusion-reaction (ADR) equations appear in various areas of life sciences, hydrogeological systems, and contaminant transport. Obtaining stable and accurate numerical solutions can be challenging as the underlying equations are coupled, nonlinear, and non-self-adjoint. Currently, there is neither a robust computational framework available nor a reliable commercial package known that can handle various complex situations. Herein, the objective of this poster presentation is to present a novel locally conservative non-negative finite element formulation that preserves the underlying physical and mathematical properties of a general linear transient anisotropic ADR equation. In continuous setting, governing equations for ADR systems possess various important properties. In general, all these properties are not inherited during finite difference, finite volume, and finite element discretizations. The objective of this poster presentation is two fold: First, we analyze whether the existing numerical formulations (such as SUPG and GLS) and commercial packages provide physically meaningful values for the concentration of the chemical species for various realistic benchmark problems. Furthermore, we also quantify the errors incurred in satisfying the local and global species balance for two popular chemical kinetics schemes: CDIMA (chlorine dioxide-iodine-malonic acid) and BZ (Belousov--Zhabotinsky). Based on these numerical simulations, we show that SUPG and GLS produce unphysical values for concentration of chemical species due to the violation of the non-negative constraint, contain spurious node-to-node oscillations, and have large errors in local and global species balance. Second, we proposed a novel finite element formulation to overcome the above difficulties. The proposed locally conservative non-negative computational framework based on low-order least-squares finite elements is able to preserve these underlying physical and mathematical properties. Several representative numerical examples are discussed to illustrate the importance of the proposed numerical formulations to accurately describe various aspects of mixing process in chaotic flows and to simulate transport in highly heterogeneous anisotropic media.

Value of speckle tracking echocardiography for detection of clinically silent left ventricular dysfunction in patients with β-thalassemia.

PubMed

Parsaee, Mozhgan; Saedi, Sedigheh; Joghataei, Pegah; Azarkeivan, Azita; Alizadeh Sani, Zahra

2017-10-01

β-Thalassemia is an inherited hemoglobin disorder resulting in chronic hemolytic anemia requiring chronic transfusion therapy. Cardiac involvement is the main cause of death in patients with thalassemia major. The narrow border is between overt myocardial dysfunction and clinically silent left ventricular (LV) dysfunction in patients with thalassemia. Therefore, we need novel parameters in different imaging techniques to discover cardiac involvement in an early and subtle stage. We explore to find a novel, straightforward and informative parameter in echocardiography as a noninvasive, economical and really routine in clinical practice. In this prospective study, 55 patients, who are known cases of β-thalassemia major, receiving long-term blood transfusions and undergoing iron chelation therapy were enrolled. Ferritin level, cardiac magnetic resonance (CMR) T2 * value, full conventional echocardiography and speckle tracking, LV regional circumferential and longitudinal strain values (%) and time-to-peak strain (ms) of 17 segments cardiac model in eyeball tomogram were measured. There was a significant reduction in global longitudinal strain (GLS) (-20.9% ± 1.9 vs. -22.2 ± 1.03) and also basal segments longitudinal strain compared to normal subjects group (-17.4% ± 2.7 vs. -19.6% ± 1.2). There was no significant difference in circumferential strain value between thalassemia patients and normal control group. Interestingly, there was no significant correlation between GLS and CMR T2 * values showing no association between cardiac iron load and longitudinal strain. Speckle tracking echocardiography could be used as a feasible method for evaluating subclinical myocardial dysfunction in patients with thalassemia major. Echocardiography, using GLS, could predict clinically silent myocardial dysfunction independent of CMR (T2 * value) and extension of iron deposition. Our study also puts forward other causes such as chronic tissue hypoxia resulting from chronic anemia as a root cause and initiating factor for subsequent injury by the iron deposition. Speckle tracking can recognize the cardiac involvement in really early stages.

Understanding the roles of glutamine synthetase, glutaminase, and glutamate decarboxylase autoantibodies in imbalanced excitatory/inhibitory neurotransmission as etiological mechanisms of autism.

PubMed

Hamed, Najat O; Al-Ayadhi, Laila; Osman, Mohamed A; Elkhawad, Abdalla O; Qasem, Hanan; Al-Marshoud, Majida; Merghani, Nada M; El-Ansary, Afaf

2018-05-01

Autism is a heterogeneous neurological disorder that is characterized by impairments in communication and social interactions, repetitive behaviors, and sensory abnormalities. The etiology of autism remains unclear. Animal, genetic, and post-mortem studies suggest that an imbalance exists in the neuronal excitation and inhibition system in autism. The aim of this study was to determine whether alterations of the measured parameters in children with autism are significantly associated with the risk of a sensory dysfunction. The glutamine synthetase (GS), kidney-type glutaminase (GLS1), and glutamic acid decarboxylase autoantibody levels were analyzed in 38 autistic children and 33 age- and sex-matched controls using enzyme-linked immunosorbent assays. The obtained data demonstrated significant alterations in glutamate and glutamine cycle enzymes, as represented by GS and GLS1, respectively. While the glutamic acid decarboxylase autoantibodies levels were remarkably increased, no significant difference was observed compared to the healthy control participants. The obtained data indicate that GS and GLS1 are promising indicators of a neuronal excitation and inhibition system imbalance and that combined measured parameters are good predictive biomarkers of autism. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

Crystal Structures of the Scaffolding Protein LGN Reveal the General Mechanism by Which GoLoco Binding Motifs Inhibit the Release of GDP from Gαi *

PubMed Central

Jia, Min; Li, Jianchao; Zhu, Jinwei; Wen, Wenyu; Zhang, Mingjie; Wang, Wenning

2012-01-01

GoLoco (GL) motif-containing proteins regulate G protein signaling by binding to Gα subunit and acting as guanine nucleotide dissociation inhibitors. GLs of LGN are also known to bind the GDP form of Gαi/o during asymmetric cell division. Here, we show that the C-terminal GL domain of LGN binds four molecules of Gαi·GDP. The crystal structures of Gαi·GDP in complex with LGN GL3 and GL4, respectively, reveal distinct GL/Gαi interaction features when compared with the only high resolution structure known with GL/Gαi interaction between RGS14 and Gαi1. Only a few residues C-terminal to the conserved GL sequence are required for LGN GLs to bind to Gαi·GDP. A highly conserved “double Arg finger” sequence (RΨ(D/E)(D/E)QR) is responsible for LGN GL to bind to GDP bound to Gαi. Together with the sequence alignment, we suggest that the LGN GL/Gαi interaction represents a general binding mode between GL motifs and Gαi. We also show that LGN GLs are potent guanine nucleotide dissociation inhibitors. PMID:22952234

Global longitudinal strain by two-dimensional speckle tracking imaging predicts exercise capacity in patients with chronic heart failure.

PubMed

Kou, Seisyou; Suzuki, Kengo; Akashi, Yoshihiro J; Mizukoshi, Kei; Takai, Manabu; Izumo, Masaki; Shimozato, Takashi; Hayashi, Akio; Ohtaki, Eiji; Osada, Naohiko; Omiya, Kazuto; Nobuoka, Sachihiko; Miyake, Fumihiko

2011-06-01

Left ventricular ejection fraction (LVEF) predicts mortality in patients with chronic heart failure (CHF). However, a weak correlation was found between LVEF and peak oxygen uptake ([Formula: see text]) in CHF patients. Global longitudinal strain measured by two-dimensional (2D) strain is regarded as a more useful predictor of cardiac events than LVEF. We investigated whether 2D strain obtained at rest could predict peak [Formula: see text] in patients with CHF. Fifty-one patients (mean age of 54.0 ± 12.0 years, 14 females, LVEF 46.0 ± 15.0%) with stable CHF underwent resting echocardiography and cardiopulmonary exercise testing. Leg muscle strength was measured for the evaluation of peripheral factors. Global longitudinal strain (GLS) in the apical 4-, 3-, and 2-chamber views and global circumferential strain (GCS) in the parasternal mid short-axis view were measured. In all patients, peak [Formula: see text] correlated with leg muscle strength (r = 0.55, p < 0.0001), LVEF (r = 0.46, p < 0.001), GLS (r = -0.45, p < 0.001), and GCS (r = -0.41, p = 0.005), respectively. No significant correlation was found between the ratio of early transmitral velocity to peak early diastolic mitral annulus velocity (E/E') and peak [Formula: see text]. In the patients with heart failure and reduced LVEF, a multiple stepwise linear regression analysis based on leg muscle strength, LVEF, E/E', GLS, and GCS was performed to identify independent predictors of peak [Formula: see text], resulting in leg muscle strength and GLS (R (2) = 0.888) as independent predictors of peak [Formula: see text]. Global longitudinal strain at rest could possibly predict exercise capacity, which appeared to be more useful than LVEF, E/E', and GCS in CHF patients with reduced LVEF.

Characterization of Glutamatergic Neurons in the Rat Atrial Intrinsic Cardiac Ganglia that Project to the Cardiac Ventricular Wall

PubMed Central

Wang, Ting; Miller, Kenneth E.

2016-01-01

The intrinsic cardiac nervous system modulates cardiac function by acting as an integration site for regulating autonomic efferent cardiac output. This intrinsic system is proposed to be composed of a short cardio-cardiac feedback control loop within the cardiac innervation hierarchy. For example, electrophysiological studies have postulated the presence of sensory neurons in intrinsic cardiac ganglia for regional cardiac control. There is still a knowledge gap, however, about the anatomical location and neurochemical phenotype of sensory neurons inside intrinsic cardiac ganglia. In the present study, rat intrinsic cardiac ganglia neurons were characterized neurochemically with immunohistochemistry using glutamatergic markers: vesicular glutamate transporters 1 and 2 (VGLUT1; VGLUT2), and glutaminase (GLS), the enzyme essential for glutamate production. Glutamatergic neurons (VGLUT1/VGLUT2/GLS) in the ICG that have axons to the ventricles were identified by retrograde tracing of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected in the ventricular wall. Co-labeling of VGLUT1, VGLUT2, and GLS with the vesicular acetylcholine transporter (VAChT) was used to evaluate the relationship between post-ganglionic autonomic neurons and glutamatergic neurons. Sequential labeling of VGLUT1 and VGLUT2 in adjacent tissue sections was used to evaluate the co-localization of VGLUT1 and VGLUT2 in ICG neurons. Our studies yielded the following results: (1) intrinsic cardiac ganglia contain glutamatergic neurons with GLS for glutamate production and VGLUT1 and 2 for transport of glutamate into synaptic vesicles; (2) atrial intrinsic cardiac ganglia contain neurons that project to ventricle walls and these neurons are glutamatergic; (3) many glutamatergic ICG neurons also were cholinergic, expressing VAChT. (4) VGLUT1 and VGLUT2 co-localization occurred in ICG neurons with variation of their protein expression level. Investigation of both glutamatergic and cholinergic ICG neurons could help in better understanding the function of the intrinsic cardiac nervous system. PMID:27167082

Characterization of glutamatergic neurons in the rat atrial intrinsic cardiac ganglia that project to the cardiac ventricular wall.

PubMed

Wang, Ting; Miller, Kenneth E

2016-08-04

The intrinsic cardiac nervous system modulates cardiac function by acting as an integration site for regulating autonomic efferent cardiac output. This intrinsic system is proposed to be composed of a short cardio-cardiac feedback control loop within the cardiac innervation hierarchy. For example, electrophysiological studies have postulated the presence of sensory neurons in intrinsic cardiac ganglia (ICG) for regional cardiac control. There is still a knowledge gap, however, about the anatomical location and neurochemical phenotype of sensory neurons inside ICG. In the present study, rat ICG neurons were characterized neurochemically with immunohistochemistry using glutamatergic markers: vesicular glutamate transporters 1 and 2 (VGLUT1; VGLUT2), and glutaminase (GLS), the enzyme essential for glutamate production. Glutamatergic neurons (VGLUT1/VGLUT2/GLS) in the ICG that have axons to the ventricles were identified by retrograde tracing of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injected in the ventricular wall. Co-labeling of VGLUT1, VGLUT2, and GLS with the vesicular acetylcholine transporter (VAChT) was used to evaluate the relationship between post-ganglionic autonomic neurons and glutamatergic neurons. Sequential labeling of VGLUT1 and VGLUT2 in adjacent tissue sections was used to evaluate the co-localization of VGLUT1 and VGLUT2 in ICG neurons. Our studies yielded the following results: (1) ICG contain glutamatergic neurons with GLS for glutamate production and VGLUT1 and 2 for transport of glutamate into synaptic vesicles; (2) atrial ICG contain neurons that project to ventricle walls and these neurons are glutamatergic; (3) many glutamatergic ICG neurons also were cholinergic, expressing VAChT; (4) VGLUT1 and VGLUT2 co-localization occurred in ICG neurons with variation of their protein expression level. Investigation of both glutamatergic and cholinergic ICG neurons could help in better understanding the function of the intrinsic cardiac nervous system. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Glutaminase and MMP-9 Downregulation in Cortex and Hippocampus of LPA1 Receptor Null Mice Correlate with Altered Dendritic Spine Plasticity

PubMed Central

Peñalver, Ana; Campos-Sandoval, José A.; Blanco, Eduardo; Cardona, Carolina; Castilla, Laura; Martín-Rufián, Mercedes; Estivill-Torrús, Guillermo; Sánchez-Varo, Raquel; Alonso, Francisco J.; Pérez-Hernández, Mercedes; Colado, María I.; Gutiérrez, Antonia; de Fonseca, Fernando Rodríguez; Márquez, Javier

2017-01-01

Lysophosphatidic acid (LPA) is an extracellular lipid mediator that regulates nervous system development and functions acting through G protein-coupled receptors (GPCRs). Here we explore the crosstalk between LPA1 receptor and glutamatergic transmission by examining expression of glutaminase (GA) isoforms in different brain areas isolated from wild-type (WT) and KOLPA1 mice. Silencing of LPA1 receptor induced a severe down-regulation of Gls-encoded long glutaminase protein variant (KGA) (glutaminase gene encoding the kidney-type isoforms, GLS) protein expression in several brain regions, particularly in brain cortex and hippocampus. Immunohistochemical assessment of protein levels for the second type of glutaminase (GA) isoform, glutaminase gene encoding the liver-type isoforms (GLS2), did not detect substantial differences with regard to WT animals. The regional mRNA levels of GLS were determined by real time RT-PCR and did not show significant variations, except for prefrontal and motor cortex values which clearly diminished in KO mice. Total GA activity was also significantly reduced in prefrontal and motor cortex, but remained essentially unchanged in the hippocampus and rest of brain regions examined, suggesting activation of genetic compensatory mechanisms and/or post-translational modifications to compensate for KGA protein deficit. Remarkably, Golgi staining of hippocampal regions showed an altered morphology of glutamatergic pyramidal cells dendritic spines towards a less mature filopodia-like phenotype, as compared with WT littermates. This structural change correlated with a strong decrease of active matrix-metalloproteinase (MMP) 9 in cerebral cortex and hippocampus of KOLPA1 mice. Taken together, these results demonstrate that LPA signaling through LPA1 influence expression of the main isoenzyme of glutamate biosynthesis with strong repercussions on dendritic spines maturation, which may partially explain the cognitive and learning defects previously reported for this colony of KOLPA1 mice. PMID:28928633

The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.

PubMed

Dobson, Laura E; Musa, Tarique A; Uddin, Akhlaque; Fairbairn, Timothy A; Bebb, Owen J; Swoboda, Peter P; Haaf, Philip; Foley, James; Garg, Pankaj; Fent, Graham J; Malkin, Christopher J; Blackman, Daniel J; Plein, Sven; Greenwood, John P

2017-02-22

Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m 2 , p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population.

Design of a patterned nanostructure array using a nanosecond pulsed laser

NASA Astrophysics Data System (ADS)

Yoshida, Yutaka; Ohnishi, Ko; Matsuo, Yasutaka; Watanabe, Seiichi

2018-04-01

For design the patterned nanostructure array (PNSA) on material surface using a nanosecond pulsed laser, we investigated the influence of phase shift between scattered lights on silicon (Si) substrate using 30-nm-wide gold lines (GLs) spacings. At a spacing of 5,871 nm, ten nanodot (ND) arrays were formed at intervals of 533 nm by nanosecond pulsed laser. The results show that the formation of the PNSA was affected by the resonance of scattered light. We conclude that ND arrays were formed with a spacing of Λ = nλ. And we have designed PNSA comprising two ND arrays on the substrate. The PNSA with dimensions of 1,600 nm × 1,600 nm was prepared using GLs.

Heterocyclic Compounds: Effective α-Amylase and α-Glucosidase Inhibitors.

PubMed

Saeedi, Mina; Hadjiakhondi, Abbas; Nabavi, Seyed Mohammad; Manayi, Azadeh

2017-01-01

Diabetes Mellitus (DM) is a metabolic disease characterized by high blood sugar levels. Recently, it has emerged as an important and global health problem with long-term complications and high economic burden. α-Amylase (α-Amy) and α-glucosidase (α-Gls) are two enzymes which are involved in the hydrolysis of starch into sugars and disaccharides leading to the increase of blood glucose level. Hence, inhibition of α-amylase and α-glucosidase plays key role in the treatment of type 2 diabetes. Heterocyclic compounds -both synthetic and naturally occurring derivatives- possess efficient biological properties. At this juncture, they have demonstrated potent inhibitory activity against α-Amy and α-Gls and were found to be versatile tools for the development of novel anti-diabetic agents.

Amplitude death and synchronized states in nonlinear time-delay systems coupled through mean-field diffusion

NASA Astrophysics Data System (ADS)

Banerjee, Tanmoy; Biswas, Debabrata

2013-12-01

We explore and experimentally demonstrate the phenomena of amplitude death (AD) and the corresponding transitions through synchronized states that lead to AD in coupled intrinsic time-delayed hyperchaotic oscillators interacting through mean-field diffusion. We identify a novel synchronization transition scenario leading to AD, namely transitions among AD, generalized anticipatory synchronization (GAS), complete synchronization (CS), and generalized lag synchronization (GLS). This transition is mediated by variation of the difference of intrinsic time-delays associated with the individual systems and has no analogue in non-delayed systems or coupled oscillators with coupling time-delay. We further show that, for equal intrinsic time-delays, increasing coupling strength results in a transition from the unsynchronized state to AD state via in-phase (complete) synchronized states. Using Krasovskii-Lyapunov theory, we derive the stability conditions that predict the parametric region of occurrence of GAS, GLS, and CS; also, using a linear stability analysis, we derive the condition of occurrence of AD. We use the error function of proper synchronization manifold and a modified form of the similarity function to provide the quantitative support to GLS and GAS. We demonstrate all the scenarios in an electronic circuit experiment; the experimental time-series, phase-plane plots, and generalized autocorrelation function computed from the experimental time series data are used to confirm the occurrence of all the phenomena in the coupled oscillators.

The Glutaminase-1 Inhibitor 968 Enhances Dihydroartemisinin-Mediated Antitumor Efficacy in Hepatocellular Carcinoma Cells

PubMed Central

Zheng, Meihong; Zhang, Yonghui; Chen, Aiping; Wu, Junhua; Wei, Jiwu

2016-01-01

Reprogrammed metabolism and redox homeostasis are potential targets of cancer therapy. Our previous study demonstrated that the kidney form of glutaminase (GLS1) is highly expressed in hepatocellular carcinoma (HCC) cells and can be used as a target for effective anticancer therapy. Dihydroartemisinin (DHA) increases intracellular reactive oxygen species (ROS) levels leading to cytotoxicity in cancer cells. However, the heterogeneity of cancer cells often leads to differing responses to oxidative lesions. For instance, cancer cells with high ratio of GSH/GSSG, a critical ROS scavenger, are resistant to ROS-induced cytotoxicity. We postulate that a combinatorial strategy firstly disrupting redox homeostasis followed by DHA might yield a profound antitumor efficacy. In this study, when HCC cells were treated with a GLS1 inhibitor 968, the ROS elimination capacity was significantly reduced in HCC cells, which rendered HCC cells but not normal endothelial cells more sensitive to DHA-mediated cytotoxicity. We further confirmed that this synergistic antitumor efficacy was mediated by excessive ROS generation in HCC cells. NAC, a ROS inhibitor, partly rescued the combinatorial cytotoxic effect of 968 and DHA. Given that GLS1 is a potential antitumor target and DHA has been safely used in clinic, our findings provide new insight into liver cancer therapy targeting glutamine metabolism combined with the ROS generator DHA, which can be readily translated into cancer clinical trials. PMID:27835669

Association between left ventricular perfusion defects and myocardial deformation indexes in heart transplantation recipients.

PubMed

D'Andrea, Antonello; De Rimini, Maria Luisa; America, Raffaella; Cirillo, Chiara; Riegler, Lucia; Limongelli, Giuseppe; D'Alto, Michele; Salerno, Gemma; Maiello, Ciro; Muto, Pietro; Russo, Maria Giovanna; Calabrò, Raffaele; Bossone, Eduardo; Pacileo, Giuseppe

2017-10-01

The aim of the study was to analyze possible correlations between strain echocardiography (STE) and PET myocardial perfusion in a population of heart transplantation (HTx) recipients showing preserved left ventricular (LV) ejection fraction. By STE, LV global longitudinal strain (LV GLS) was lower in HTx. PET showed no transient or chronic ischemia in 83 of 115 HTx (73%). Fixed perfusion defects were observed in 17% of HTx and reversible ischemia in 10%. Significant coronary stenosis was observed only in 10 cases. GLS was independently associated with age at HTx and fixed perfusion defects (HR 0.41; P<.001). Such relationships underline STE ability to early identify HTx pts with subclinical myocardial dysfunction during long-term follow-up. © 2017, Wiley Periodicals, Inc.

Late Detection of Left Ventricular Dysfunction Using Two-Dimensional and Three-Dimensional Speckle-Tracking Echocardiography in Patients with History of Nonsevere Acute Myocarditis.

PubMed

Caspar, Thibault; Fichot, Marie; Ohana, Mickaël; El Ghannudi, Soraya; Morel, Olivier; Ohlmann, Patrick

2017-08-01

Acute myocarditis (AM) often involves the left ventricular (LV) subepicardium that might be displayed by cardiac magnetic resonance even late after the acute phase. In the absence of global or regional LV dysfunction, conventional transthoracic echocardiography (TTE) does not accurately identify tissue sequelae of AM. We sought to evaluate the diagnostic value of two-dimensional (2D) and three-dimensional (3D) speckle-tracking echocardiography to identify patients with a history of AM with preserved LV ejection fraction (LVEF). Fifty patients (group 1: age, 31.4 ± 10.5 years; 76% males) with a history of cardiac magnetic resonance-confirmed diagnosis of AM (according to the Lake Louise criteria) were retrospectively identified and then (21.7 ± 23.4 months later) evaluated by complete echocardiography including 2D and 3D speckle-tracking analysis, as well as 50 age- and gender-matched healthy controls (group 2: age, 31.2 ± 9.5 years: 76% males). Patients with a history of severe clinical presentation of AM (sudden death, ventricular arrhythmia, heart failure, alteration of LVEF) were excluded. At diagnosis, peak troponin and C-reactive protein were 11.97 (interquartile range, 4.52-25.92) μg/L and 32.3 (interquartile range, 14.85-70.45) mg/L, respectively. Mean delay between acute phase and follow-up study TTE was 21.7 ± 23.4 months. LVEF was not statistically different between groups (62.1% vs 63.5%, P = .099). Two-dimensional global longitudinal strain (GLS) was lower in magnitude in group 1 (-17.8% vs -22.1%, P < .0001) as were 2D layer-specific subepicardial GLS (-15.4% vs -19.7%, P < .0001) and subendocardial GLS (-20.71% vs -25.08%, P < .0001). Three-dimensional global longitudinal, circumferential, area, and radial strains were lower in magnitude in group 1 (-11.80% vs -14.98%, P < .0001; -12.57% vs -15.12%, P < .0001; -22.28% vs -25.87%, P < .0001; 31.47% vs 38.06%, P < .0001, respectively). Receiver operating characteristic curve analysis showed that subepicardial GLS displayed a better diagnostic performance to detect sequelae of AM as compared with GLS (area under the curve = 0.97 vs 0.93, P = .045). In patients with a history of AM, a subtle LV dysfunction can be detected by 2D and 3D speckle-tracking echocardiography, even though LVEF is conserved, adding incremental information over conventional TTE. Copyright © 2017 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Effect of sprout extract from Tuscan black cabbage on xenobiotic-metabolizing and antioxidant enzymes in rat liver.

PubMed

Melega, Simone; Canistro, Donatella; Pagnotta, Eleonora; Iori, Renato; Sapone, Andrea; Paolini, Moreno

2013-02-18

In recent years, health protection by natural products has received considerable attention, and a multitude of nutraceuticals have been characterized and their use promoted. Dietary consumption of Cruciferous vegetables, rich in glucosinolates (GLs), and their myrosinase-mediated hydrolysis products isothiocyanates (ITCs), were associated with reductions in cancer risk. In this study, the chemo-preventive potential of sprout extract of Tuscan black cabbage (Brassica oleracea L. var. acephala subvar. Laciniata L.) (TBCSE), through modulation of the xenobiotic-metabolizing apparatus and antioxidant defenses, was investigated in Sprague-Dawley rat liver. TBCSE was administered either orally or intraperitoneally, at a dose of 15mg/kg b.w., daily for twenty-one consecutive days, in the absence or presence of exogenous myrosinase, β-thioglucoside glucohydrolase (MYR), to distinguish the effects of intact GLs and ITCs, in the context of the extract. A complex, mild modulation pattern of P450-related monooxygenases was observed, mainly regarding CYP content (up to 36% loss), NADPH cytochrome (P450) c-reductase (up to 26% loss), CYP1A1 (up to 23% loss), but no evident distinctions among the effects of the extracts containing GLs or ITCs, were noted. In contrast, significant inductions of phase-II enzymes (up to 107% for UDP-glucuronosyl-transferase, and up to 36% for glutathione S-transferase) were recorded only where the GLs to ITCs conversion had occurred. A boosting effect on catalase (up to 38%), NAD(P)H:quinone reductase (up to 70%), glutathione reductase and glutathione peroxidase (up to 10%) was also recorded, suggesting an indirect antioxidant capacity of the extracts. Overall, the general phase-I inhibition, together with the up-regulation of detoxifying phase-II and antioxidant enzymes, exerted by the TBCSE supplementation, seem to be in line with the classical chemopreventive theory, but whether the addition of exogenous MYR is relevant, still remains to be clarified. These results are in support of the potential health-promoting application of TBCSE, as a nutraceutical. Copyright © 2012 Elsevier B.V. All rights reserved.

Relationship between improvement in left ventricular dyssynchrony and contractile function and clinical outcome with cardiac resynchronization therapy: the MADIT-CRT trial.

PubMed

Pouleur, Anne-Catherine; Knappe, Dorit; Shah, Amil M; Uno, Hajime; Bourgoun, Mikhail; Foster, Elyse; McNitt, Scott; Hall, W Jackson; Zareba, Wojciech; Goldenberg, Ilan; Moss, Arthur J; Pfeffer, Marc A; Solomon, Scott D

2011-07-01

To assess long-term effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) dyssynchrony and contractile function, by two-dimensional speckle-tracking echocardiography, compared with implantable cardioverter defibrillator (ICD) only in MADIT-CRT. We studied 761 patients in New York Heart Association I/II, ejection fraction ≤30%, and QRS ≥130 ms [n = 434, CRT-defibrillator (CRT-D), n = 327, ICD] with echocardiographic studies available at baseline and 12 months. Dyssynchrony was determined as the standard deviation of time to peak transverse strain between 12 segments of apical four- and two-chamber views, and contractile function as global longitudinal strain (GLS) by averaging longitudinal strain over these 12 segments. We compared changes in LV dyssynchrony and contractile function between treatment groups and assessed relationships between these changes over the first year and subsequent outcomes (median post 1-year follow-up = 14.9 months). Mean changes in LV dyssynchrony and contractile function measured by GLS in the overall population were, respectively, -29 ± 83 ms and -1 ± 2.9%. However, both LV dyssynchrony (CRT-D: -47 ± 83 ms vs. ICD: -6 ± 76 ms, P < 0.001) and contractile function (CRT-D: -1.4 ± 3.1% vs. ICD: -0.4 ± 2.5%, P < 0.001) improved to a greater extent in the CRT-D group compared with the ICD-only group. A greater improvement in dyssynchrony and contractile function at 1 year was associated with lower rates of the subsequent primary outcome of death or heart failure, adjusting for baseline dyssynchrony and contractile function, treatment arm, ischaemic status, and change in LV end-systolic volume. Each 20 ms decrease in LV dyssynchrony was associated with a 7% reduction in the primary outcome (P = 0.047); each 1% improvement in GLS over the 12-month period was associated with a 24% reduction in the primary outcome (P < 0.001). Cardiac resynchronization therapy resulted in a significant improvement in both LV dyssynchrony and contractile function measured by GLS compared with ICD only and these improvements were associated with better subsequent outcomes.

Panel data models with spatial correlation: Estimation theory and an empirical investigation of the United States wholesale gasoline industry

NASA Astrophysics Data System (ADS)

Kapoor, Mudit

The first part of my dissertation considers the estimation of a panel data model with error components that are both spatially and time-wise correlated. The dissertation combines widely used model for spatial correlation (Cliff and Ord (1973, 1981)) with the classical error component panel data model. I introduce generalizations of the generalized moments (GM) procedure suggested in Kelejian and Prucha (1999) for estimating the spatial autoregressive parameter in case of a single cross section. I then use those estimators to define feasible generalized least squares (GLS) procedures for the regression parameters. I give formal large sample results concerning the consistency of the proposed GM procedures, as well as the consistency and asymptotic normality of the proposed feasible GLS procedures. The new estimators remain computationally feasible even in large samples. The second part of my dissertation employs a Cliff-Ord-type model to empirically estimate the nature and extent of price competition in the US wholesale gasoline industry. I use data on average weekly wholesale gasoline price for 289 terminals (distribution facilities) in the US. Data on demand factors, cost factors and market structure that affect price are also used. I consider two time periods, a high demand period (August 1999) and a low demand period (January 2000). I find a high level of competition in prices between neighboring terminals. In particular, price in one terminal is significantly and positively correlated to the price of its neighboring terminal. Moreover, I find this to be much higher during the low demand period, as compared to the high demand period. In contrast to previous work, I include for each terminal the characteristics of the marginal customer by controlling for demand factors in the neighboring location. I find these demand factors to be important during period of high demand and insignificant during the low demand period. Furthermore, I have also considered spatial correlation in unobserved factors that affect price. I find it to be high and significant only during the low demand period. Not correcting for it leads to incorrect inferences regarding exogenous explanatory variables.

Impact of revascularization of coronary chronic total occlusion on left ventricular function and electrical stability: analysis by speckle tracking echocardiography and signal-averaged electrocardiogram.

PubMed

Sotomi, Yohei; Okamura, Atsunori; Iwakura, Katsuomi; Date, Motoo; Nagai, Hiroyuki; Yamasaki, Tomohiro; Koyama, Yasushi; Inoue, Koichi; Sakata, Yasushi; Fujii, Kenshi

2017-06-01

The present study aimed to assess the mechanisms of effects of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) from two different aspects: left ventricular (LV) systolic function assessed by two-dimensional speckle tracking echocardiography (2D-STE) and electrical stability evaluated by late potential on signal-averaged electrocardiogram (SAECG). We conducted a prospective observational study with consecutive CTO-PCI patients. 2D-STE and SAECG were performed before PCI, and after 1-day and 3-months of procedure. 2D-STE computed global longitudinal strain (GLS) and regional longitudinal strain (RLS) in CTO area, collateral blood-supplying donor artery area, and non-CTO/non-donor area. A total of 37 patients (66 ± 11 years, 78% male) were analyzed. RLS in CTO and donor areas and GLS were significantly improved 1-day after the procedure, but these improvements diminished during 3 months. The improvement of RLS in donor area remained significant after 3-months the index procedure (pre-PCI -13.4 ± 4.8% vs. post-3M -15.1 ± 4.5%, P = 0.034). RLS in non-CTO/non-donor area and LV ejection fraction were not influenced. Mitral annulus velocity was improved at 3-month follow-up (5.0 ± 1.4 vs. 5.6 ± 1.7 cm/s, P = 0.049). Before the procedure, 12 patients (35%) had a late potential. All components of the late potential (filtered QRS duration, root-mean-square voltage in the terminal 40 ms, and duration of the low amplitude signal <40 μV) were not improved. CTO-PCI improved RLS in the donor area at 3-month follow-up without changes of LV ejection fraction. Although higher prevalence of late potential in the current population compared to healthy population was observed, late potential as a surrogate of arrhythmogenic substrate was not influenced by CTO-PCI.

The effect of a source-contacted light shield on the electrical characteristics of an LTPS TFT

NASA Astrophysics Data System (ADS)

Kim, Miryeon; Sun, Wookyung; Kang, Jongseuk; Shin, Hyungsoon

2017-08-01

The electrical characteristics of a low-temperature polycrystalline silicon thin-film transistor (TFT) with a source-contacted light shield (SCLS) are observed and analyzed. Compared with that of a conventional TFT without a light shield (LS), the on-current of the TFT with an SCLS is lower because the SCLS blocks the fringing electric field from the drain to the active layer. Furthermore, the gate-to-source capacitance (C gs) of the TFT with an SCLS in the off and saturation regions is higher than that of a conventional TFT, which is due to the gate-to-LS capacitance (C g-LS). The electrical characteristics of the TFT with an SCLS are thoroughly investigated by two-dimensional device simulations, and a semi-empirical C g-LS model for SPICE simulation is proposed and verified.

Future Perspectives for Management of Stage A Heart Failure.

PubMed

Tanaka, Hidekazu

2018-05-07

Patients with Stage A heart failure (HF) show no HF symptoms but have related comorbid diseases with a high risk of progressing to HF. Screening for comorbid diseases warrants closer attention because of the growing interest in addressing Stage A HF as the best means of preventing eventual progression to overt HF such as Stages C and D. The identification of individuals of Stage A HF is potentially useful for the implementation of HF-prevention strategies; however, not all Stage A HF patients develop left ventricular (LV) structural heart disease or symptomatic HF, which lead to advanced HF stages. Therefore, Stage A HF requires management with the long-term goal of avoiding HF development; likewise, Stage B HF patients are ideal targets for HF prevention. Although the early detection of subclinical LV dysfunction is, thus, essential for delaying the progression to HF, the assessment of subclinical LV dysfunction can be challenging. Global longitudinal strain (GLS) as assessed by speckle-tracking echocardiography has recently been reported to be a sensitive marker of early subtle LV myocardial abnormalities, helpful for the prediction of the outcomes for various cardiac diseases, and superior to conventional echocardiographic indices. GLS reflects LV longitudinal myocardial systolic function, and can be assessed usually by means of two-dimensional speckle-tracking. This article reviews the importance of the assessment of subclinical LV dysfunction in Stage A HF patients by means of GLS, and its current potential to prevent progression to later stage HF.

Modification of oil and glucosinolate content in canola seeds with altered expression of Brassica napus LEAFY COTYLEDON1.

PubMed

Elahi, Nosheen; Duncan, Robert W; Stasolla, Claudio

2016-03-01

Over the last few decades, research focusing on canola (Brassica napus L.) seed oil content and composition has expanded. Oil production and accumulation are influenced by genes participating in embryo and seed development. The Arabidopsis LEAFY COTYLEDON1 (LEC1) is a well characterized regulator of embryo development that also enhances the expression of genes involved in fatty acid (FA) synthesis. B. napus lines over-expressing or down-regulating BnLEC1 were successfully generated by Agrobacterium-mediated transformation. The constitutive expression of BnLEC1 in B. napus var. Polo, increased seed oil content by 7-16%, while the down-regulation of BnLEC1 in B. napus var. Topas reduced oil content by 9-12%. Experimental manipulation of BnLEC1 caused transcriptional changes in enzymes participating in sucrose metabolism, glycolysis, and FA biosynthesis, suggesting an enhanced carbon flux towards FA biosynthesis in tissues over-expressing BnLEC1. The increase in oil content induced by BnLEC1 was not accompanied by alterations in FA composition, oil nutritional value or glucosinolate (GLS) levels. Suppression of BnLEC1 reduced seed oil accumulation and elevated the level of GLS possibly through the transcriptional regulation of BnST5a (Sulphotransferase5a), the last GLS biosynthetic enzyme. Collectively, these findings demonstrate that experimental alterations of BnLEC1 expression can be used to influence oil production and quality in B. napus. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Micro-RNA-21 (biomarker) and global longitudinal strain (functional marker) in detection of myocardial fibrotic burden in severe aortic valve stenosis: a pilot study.

PubMed

Fabiani, Iacopo; Scatena, Cristian; Mazzanti, Chiara Maria; Conte, Lorenzo; Pugliese, Nicola Riccardo; Franceschi, Sara; Lessi, Francesca; Menicagli, Michele; De Martino, Andrea; Pratali, Stefano; Bortolotti, Uberto; Naccarato, Antonio Giuseppe; La Carrubba, Salvatore; Di Bello, Vitantonio

2016-08-27

Myocardial fibrosis (MF) is a deleterious consequence of aortic valve stenosis (AVS). Global longitudinal strain (GLS) is a novel left ventricular (LV) functional parameter potentially useful to non-invasively estimate MF. MicroRNAs (miRNAs) are non-coding small ribonucleic acids (RNA) modulating genes function, mainly through RNA degradation. miRNA-21 is a biomarker associated with MF in pressure overload. The aim of the present study was to find an integrated algorithm for detection of MF using a combined approach with both bio- and functional markers. Thirty-six patients (75.2 ± 8 y.o.; 63 % Female) with severe AVS and preserved LV ejection fraction (EF), candidate to surgical aortic valve replacement (sAVR) were enrolled. Clinical, bio-humoral evaluation (including plasmatic miRNA-21 collected using specific tubes, PAXgene, for stabilization of peripheral RNA) and a complete echocardiographic study, including GLS and septal strain, were performed before sAVR. Twenty-eight of those patients underwent sAVR and, in 23 of them, an inter-ventricular septum biopsy was performed. Tissues were fixed in formalin and embedded in paraffin. Sections were stained with Hematoxylin and Eosin for histological evaluation and with histochemical Masson trichrome for collagen fibers. The different components were calculated and expressed as micrometers(2). To evaluate tissue miRNA components, sections 2-μm thick were cut using a microtome blade for each slide. Regression analysis was performed to test association between dependent variable and various predictors included in the model. Despite a preserved EF (66 ± 11 %), patients presented altered myocardial deformation parameters (GLS -14,02 ± 3.8 %; septal longitudinal strain, SSL -9.63 ± 2.9 %; septal longitudinal strain rate, SL-Sr -0.58 ± 0.17 1/s; Septal Longitudinal early-diastolic strain rate, SL-SrE 0.62 ± 0.32 1/s). The extent of MF showed an inverse association with both GLS and septal longitudinal deformation indices (GLS: R(2) = 0.30; p = 0.02; SSL: R(2) = 0.36; p = 0.01; SL-Sr: R(2) = 0.39; p < 0.001; SL-SrE: R(2) = 0.35; p = 0.001). miRNA-21 was mainly expressed in fibrous tissue (p < 0.0001). A significant association between MF and plasmatic miRNA-21, alone and weighted for measures of structural (LVMi R(2) = 0.50; p = 0.0005) and functional (SSL R(2) = 0.35; p = 0.006) remodeling, was found. In AVS, MF is associated with alterations of regional and global strain. Plasmatic miRNA-21 is directly related to MF and associated with LV structural and functional impairment.

The Activation by Glucose of Liver Membrane Nitric Oxide Synthase in the Synthesis and Translocation of Glucose transporter-4 in the Production of Insulin in the Mice Hepatocytes

PubMed Central

Bhattacharya, Suman; Ghosh, Rajeshwary; Maiti, Smarajit; Khan, Gausal Azam; Sinha, Asru K.

2013-01-01

Introduction Glucose has been reported to have an essential role in the synthesis and secretion of insulin in hepatocytes. As the efflux of glucose is facilitated from the liver cells into the circulation, the mechanism of transportation of glucose into the hepatocytes for the synthesis of insulin was investigated. Methods Grated liver suspension (GLS) was prepared by grating intact liver from adult mice by using a grater. Nitric oxide (NO) was measured by methemoglobin method. Glucose transporter-4 (Glut-4) was measured by immunoblot technique using Glut-4 antibody. Results Incubation of GLS with different amounts of glucose resulted in the uptake of glucose by the suspension with increased NO synthesis due to the stimulation of a glucose activated nitric oxide synthase that was present in the liver membrane. The inhibition of glucose induced NO synthesis resulted in the inhibition of glucose uptake. Glucose at 0.02M that maximally increased NO synthesis in the hepatocytes led to the translocation and increased synthesis of Glut-4 by 3.3 fold over the control that was inhibited by the inhibition of NO synthesis. The glucose induced NO synthesis was also found to result in the synthesis of insulin, in the presence of glucose due to the expression of both proinsulin genes I and II in the liver cells. Conclusion It was concluded that glucose itself facilitated its own transportation in the liver cells both via Glut-4 and by the synthesis of NO which had an essential role for insulin synthesis in the presence of glucose in these cells. PMID:24349154

Echocardiography vs magnetic resonance imaging in assessing ventricular function and systemic atrioventricular valve status in adults with congenitally corrected transposition of the great arteries.

PubMed

Kowalik, Ewa; Mazurkiewicz, Łukasz; Kowalski, Mirosław; Klisiewicz, Anna; Marczak, Magdalena; Hoffman, Piotr

2016-11-01

The survival in adults with congenitally corrected transposition of the great arteries (ccTGA) might be reduced due to dysfunction of the systemic right ventricle (sRV). The quantitative echocardiographic assessment of sRV function and tricuspid (systemic atrioventricular valve) regurgitation (TR) is still a diagnostic challenge. Thus, the aim of this study was to compare echocardiographic indices of sRV function and the degree of TR with corresponding MRI (magnetic resonance imaging)-derived parameters in adults with ccTGA. A prospective cross-sectional study of adults with ccTGA referred to a tertiary congenital heart disease center was conducted. All patients underwent transthoracic echocardiography and MRI examinations. Thirty-three adults (19F/14M, mean age 34.1 years) were included. We found significantly lower fractional area change (FAC) and global longitudinal strain (GLS) values in patients with MRI-derived RV ejection fraction (EF) <45%. A cutoff GLS<-16.3% identified sRV EF ≥45% with a sensitivity of 77.3% and specificity of 72.7%. A very strong correlation between MRI- and echocardiography-derived TR volume was observed (r=.84; P<.0001). GLS is the variable with the best sensitivity but less specificity to distinguish between systemic RV EF ≥45% and below 45%, and it seems to be the preferred echocardiographic index of systemic RV function in adults with ccTGA. The quantitative assessment of TR by MRI and echocardiography showed a very strong agreement in patients with ccTGA. © 2016, Wiley Periodicals, Inc.

Evaluation of Trastuzumab-induced early cardiac dysfunction using two-dimensional Strain Echocardiography.

PubMed

Emren, Sadik Volkan; Tuluce, Selcen Yakar; Levent, Fatih; Tuluce, Kamil; Kalkan, Toygar; Yildiz, Yasar; Alacacioğlu, Ahmet; Kucukzeybek, Yüksel; Akyol, Murat; Salman, Tarık

2015-12-01

Trastuzumab, a chemotherapeutic agent used in the treatment of breast cancer. has been shown to induce subclinical left ventricular (LV) dysfunction during a three to six month period as evidenced by strain echocardiographic examination without any change occurring in the ejection fraction of LV. The present study evaluated the presence of subclinical LV dysfunction using strain echocardiography 1 day and 7 days after the initiation of trastuzumab therapy. The patients with breast cancer receiving adjuvant trastuzumab therapy underwent 2-dimensional, tissue Doppler, and strain echocardiographic examination at baseline and 1 day and 7 days after therapy. LV global longitudinal strain (GLS), global circumferential strain (GCS) values, and other echocardiographic parameters were calculated. A total of 40 females, mean age 50+/-10 years, were evaluated. Of these patients, 97% received anthracycline and 73% received radiotherapy before the initiation of trastuzumab therapy. No change was observed in any of the echocardiographic parameters 1 day after the initiation of trastuzumab therapy (p>0.05). The LV ejection fraction, tissue Doppler parameters, and GCS values did not show any changes 7 days after the initiation of therapy, whereas significant decreases were observed in GLS value (19.2+/-4.0% vs. 17.2+/-3.4, p=0.001) and systolic annular velocity of the lateral LV wall (S' velocity) (10.5+/-3.2 vs. 8.6+/-2.2, p=0.002). Trastuzumab therapy is associated with subclinical LV dysfunction as early as 7 days after initiation of the therapy as evidenced by the decreases in GLS value of LV and systolic annular velocity of the lateral LV wall.

Food as Pharma? The Case of Glucosinolates.

PubMed

Capuano, Edoardo; Dekker, Matthijs; Verkerk, Ruud; Oliviero, Teresa

2017-01-01

Glucosinolates (GLSs) are dietary plant secondary metabolites occurring in the order Brassicales with potential health effects, in particular as anti-carcinogenic compounds. GLSs are converted into a variety of breakdown products (BPs) upon plant tissue damage and by the gut microbiota. GLS biological activity is related to BPs rather than to GLSs themselves. we have reviewed the most recent scientific literature on the metabolic fate and the biological effect of GLSs with particular emphasis on the epidemiological evidence for health effect and evidence from clinical trials. An overview of potential molecular mechanisms underlying GLS biological effect is provided. The potential toxic or anti-nutritional effect has also been discussed. Epidemiological and human in vivo evidence point towards a potential anti-cancer effect for sulforaphane, indole-3-carbinol and 3,3-diindolylmethane. A number of new human clinical trials are on-going and will likely shed further light on GLS protective effect towards cancer as well as other diseases. BPs biological effect is the results of a plurality of molecular mechanisms acting simultaneously which include modulation of xenobiotic metabolism, modulation of inflammation, regulation of apoptosis, cell cycle arrest, angiogenesis and metastasis and regulation of epigenetic events. BPs have been extensively investigated for their protective effect towards cancer but in recent years the interest also includes other diseases. It appears that certain BPs may protect against and may even represent a therapeutic strategy against several forms of cancer. Whether this latter effect can be achieved through diet or supplements should be investigated more thoroughly. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Echocardiographic assessment of right heart function in heart transplant recipients and the relation to exercise hemodynamics.

PubMed

Clemmensen, Tor Skibsted; Eiskjaer, Hans; Løgstrup, Brian Bridal; Andersen, Mads Jønsson; Mellemkjaer, Søren; Poulsen, Steen Hvitfeldt

2016-08-01

This study aimed to characterize right heart function in heart transplantation (HTx) patients using advanced echocardiographic assessment and simultaneous right heart catheterization (RHC). Comprehensive two-dimensional (2D) and three-dimensional (3D) echocardiographic assessment of right heart function was performed in 105 subjects (64 stable HTx patients and 41 healthy controls). RHC was performed at rest and during semi-supine maximal exercise test. Compared with controls, in conclusion, HTx patients had impaired right ventricle (RV) systolic function in terms of decreased RV-free wall (FW) global longitudinal strain (GLS) (-20 ± 5% vs. -28 ± 5%, P < 0.0001) and 3D-ejection fraction (EF) (50 ± 8% vs. 60 ± 6%, P < 0.0001). In HTx patients, echocardiographic RV systolic function was significantly correlated with NYHA-class (3D-RVEF: r = -0.62, P < 0.0001; RV-FW-GLS: r = -0.41, P = 0.0009) and cardiac allograft vasculopathy (3D-RVEF: r = -0.42, P = 0.0005; RV-FW-GLS: r = -0.25, P = 0.0444). RHC demonstrated a good correlation between invasively assessed resting RV-stroke volume index and exercise capacity (r = 0.58, P < 0.0001) and NYHA-class (r = -0.41, P = 0.0009). RV systolic function is reduced in HTx patients compared with controls. 3D RVEF and 2D longitudinal deformation analyses are associated with clinical performance in stable HTx patients and seem suitable in noninvasive routine right heart function evaluation after HTx. Invasively assessed RV systolic reserve was strongly associated with exercise capacity. © 2016 Steunstichting ESOT.

Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

PubMed

Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

2016-09-01

Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Gonioscopic ab interno laser sclerostomy. A pilot study in glaucoma patients.

PubMed

Latina, M A; Melamed, S; March, W F; Kass, M A; Kolker, A E

1992-11-01

The purpose of this study is to evaluate the safety and efficacy of gonioscopic ab interno laser sclerostomy (GLS) in patients with glaucoma. The technique of GLS involves iontophoresis of methylene blue dye (1%) at the limbus to focally dye the sclera and to provide subsequent delivery of 10-microsecond pulsed laser energy to the dyed area through a goniolens. The laser emits at 660 nm, a wavelength that is maximally absorbed by the methylene blue dye. Patients were evaluated for fistula formation, intraocular pressure (IOP) reduction, and adverse sequelae. Thirty-eight treatments were performed in 35 eyes. Successful complete sclerostomies were achieved in 21 eyes (55%), which was associated with an acute mean reduction in IOP of 23 mmHg. Mean preoperative IOP for all patients was 35 mmHg, and 1 hour after treatment it was reduced to 18.5 mmHg. In 4 of the 38 treatments, there was no acute IOP reduction, and these eyes were judged as failures. The mean follow-up time was 8.2 months with a maximum follow-up of 15 months. By 9 months, 50% of patients had an IOP of 22 mmHg or lower. The number of antiglaucoma medications decreased from 3.1 to 1.7 for all eyes over the 15-month follow-up period. Hyphemas (13%) were the only major complication, and these resolved spontaneously. In only one case did the IOP increase after the procedure. The results of this trial indicate that GLS is technically feasible, and preliminary results of IOP control are promising.

Fragmentations of [M-H]- anions of peptides containing Ser sulfate. A joint experimental and theoretical study.

PubMed

Tran, T T Nha; Wang, Tianfang; Hack, Sandra; Bowie, John H

2013-11-15

To determine the negative-ion cleavages from [M-H](-) ions of Ser sulfate-containing peptides using experiment and theory in concert. Fragmentations were explored using a Waters QTOF2 mass spectrometer in negative-ion electrospray mode, together with calculations at the CAM-B3LYP/6-311++g(d,p) level of theory. Peptides used in this study were: GS(SO3H)(OH) 1 GS(SO3H)(OCH3) 1a GAVS(SO3H)(OH) 2 GAVS(SO3H)(OCH3) 2a GLS(SO3H)(GVA(OH) 3 GLS(SO3H)GDA(OH) 4 GLS(SO3H)GS(SO3H)A(OH) 5. Previously, it has been shown that a peptide containing a Tyr sulfate group shows [(M-H)(-) -SO3] as the base peak. Only a small peak was observed corresponding to HOSO3(-) (formed following rearrangement of the sulfate). A Ser sulfate-containing peptide, in contrast, shows pronounced peaks due to cleavage product anions [(M-H)(-)-SO3] and HOSO3(-). Theoretical calculations at the CAM-B3LYP/6-311++g(d,p) level of theory suggest that rearrangement of a Ser sulfate to give C-terminal CO2SO3H is energetically unfavourable in comparison with fragmentation of the intact Ser sulfate to yield [(M-H)(-)-SO3] and HOSO3(-). [(M-H)(-)-H2SO4] anions are not observed in the spectra of peptides containing Ser sulfate, presumably because HOSO3(-) is a relatively weak gas-phase base (ΔGacid = 1265 kJ mol(-1)). Experimental and theoretical data suggest that [(M-H)(-)-SO3] and HOSO3(-) product anions (from a peptide with a C-terminal Ser sulfate) are formed from the serine sulfate anion accompanied by specific proton transfer. CID MS/MS/MS data for an [(M-H)(-)-SO3] ion of an underivatised sulfate-containing peptide will normally allow the determination of the amino acid sequence of that peptide. The one case we have studied where that is not the case is GLS(SO3H)GDA(OH), where the peptide contains Ser sulfate and Asp, where the diagnostic Asp cleavages are competitive with the Ser sulfate cleavages. Copyright © 2013 John Wiley & Sons, Ltd.

An Automated Algorithm to Screen Massive Training Samples for a Global Impervious Surface Classification

NASA Technical Reports Server (NTRS)

Tan, Bin; Brown de Colstoun, Eric; Wolfe, Robert E.; Tilton, James C.; Huang, Chengquan; Smith, Sarah E.

2012-01-01

An algorithm is developed to automatically screen the outliers from massive training samples for Global Land Survey - Imperviousness Mapping Project (GLS-IMP). GLS-IMP is to produce a global 30 m spatial resolution impervious cover data set for years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. This unprecedented high resolution impervious cover data set is not only significant to the urbanization studies but also desired by the global carbon, hydrology, and energy balance researches. A supervised classification method, regression tree, is applied in this project. A set of accurate training samples is the key to the supervised classifications. Here we developed the global scale training samples from 1 m or so resolution fine resolution satellite data (Quickbird and Worldview2), and then aggregate the fine resolution impervious cover map to 30 m resolution. In order to improve the classification accuracy, the training samples should be screened before used to train the regression tree. It is impossible to manually screen 30 m resolution training samples collected globally. For example, in Europe only, there are 174 training sites. The size of the sites ranges from 4.5 km by 4.5 km to 8.1 km by 3.6 km. The amount training samples are over six millions. Therefore, we develop this automated statistic based algorithm to screen the training samples in two levels: site and scene level. At the site level, all the training samples are divided to 10 groups according to the percentage of the impervious surface within a sample pixel. The samples following in each 10% forms one group. For each group, both univariate and multivariate outliers are detected and removed. Then the screen process escalates to the scene level. A similar screen process but with a looser threshold is applied on the scene level considering the possible variance due to the site difference. We do not perform the screen process across the scenes because the scenes might vary due to the phenology, solar-view geometry, and atmospheric condition etc. factors but not actual landcover difference. Finally, we will compare the classification results from screened and unscreened training samples to assess the improvement achieved by cleaning up the training samples. Keywords:

Two-dimensional speckle tracking echocardiography demonstrates no effect of active acromegaly on left ventricular strain.

PubMed

Volschan, I C M; Kasuki, L; Silva, C M S; Alcantara, M L; Saraiva, R M; Xavier, S S; Gadelha, M R

2017-06-01

Speckle tracking echocardiography (STE) allows for the study of myocardial strain (ε), a marker of early and subclinical ventricular systolic dysfunction. Cardiac disease may be present in patients with acromegaly; however, STE has never been used to evaluate these patients. To evaluate left ventricular (LV) global longitudinal strain in patients with active acromegaly with normal LV systolic function. Cross-sectional clinical study. Patients with active acromegaly with no detectable heart disease and a control group were matched for age, gender, arterial hypertension and diabetes mellitus underwent STE. Global LV longitudinal ε (GLS), left ventricular mass index (LVMi), left ventricular ejection fraction (LVEF) and relative wall thickness (RWT) were obtained via two-dimensional (2D) echocardiography using STE. Thirty-seven patients with active acromegaly (mean age 45.6 ± 13.8; 48.6% were males) and 48 controls were included. The mean GLS was not significantly different between the acromegaly group and the control group (in %, -20.1 ± 3.1 vs. -19.4 ± 2.2, p = 0.256). Mean LVMi was increased in the acromegaly group (in g/m 2 , 101.6 ± 27.1 vs. 73.2 ± 18.6, p < 0.01). There was a negative correlation between LVMi and GLS (r = -0.39, p = 0.01). Acromegaly patients, despite presenting with a higher LVMi when analyzed by 2D echocardiography, did not present with impairment in the strain when compared to a control group; this finding indicates a low chance of evolution to systolic dysfunction and agrees with recent studies that show a lower frequency of cardiac disease in these patients.

Enhanced Production of Polysaccharide Through the Overexpression of Homologous Uridine Diphosphate Glucose Pyrophosphorylase Gene in a Submerged Culture of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Higher Basidiomycetes).

PubMed

Ji, Sen-Lin; Liu, Rui; Ren, Meng-Fei; Li, Huan-Jun; Xu, Jun-Wei

2015-01-01

This study aimed to improve polysaccharide production by engineering the biosynthetic pathway in Ganoderma lucidum through the overexpression of the homologous UDP glucose pyrophosphorylase (UGP) gene. The effects of UGP gene overexpression on intracellular polysaccharide (IPS) content, extracellular polysaccharide (EPS) production, and transcription levels of 3 genes encoding the enzymes involved in polysaccharide biosynthesis, including phosphoglucomutase (PGM), UGP, and α-1,3-glucan synthase (GLS), were investigated. The maximum IPS content and EPS production in G. lucidum overexpressing the UGP gene were 24.32 mg/100 mg dry weight and 1.66 g/L, respectively, which were higher by 42% and 36% than those of the wild-type strain. The transcription levels of PGM, UGP, and GLS were up-regulated by 1.6, 2.6, and 2.4-fold, respectively, in the engineered strain, suggesting that increased polysaccharide biosynthesis may result from a higher expression of those genes.

Protective Effect of Glucosinolates Hydrolytic Products in Neurodegenerative Diseases (NDDs).

PubMed

Jaafaru, Mohammed Sani; Abd Karim, Nurul Ashikin; Enas, Mohamad Eliaser; Rollin, Patrick; Mazzon, Emanuela; Abdull Razis, Ahmad Faizal

2018-05-08

Crucifer vegetables, Brassicaceae and other species of the order Brassicales, e.g., Moringaceae that are commonly consumed as spice and food, have been reported to have potential benefits for the treatment and prevention of several health disorders. Though epidemiologically inconclusive, investigations have shown that consumption of those vegetables may result in reducing and preventing the risks associated with neurodegenerative disease development and may also exert other biological protections in humans. The neuroprotective effects of these vegetables have been ascribed to their secondary metabolites, glucosinolates (GLs), and their related hydrolytic products, isothiocyanates (ITCs) that are largely investigated for their various medicinal effects. Extensive pre-clinical studies have revealed more than a few molecular mechanisms of action elucidating multiple biological effects of GLs hydrolytic products. This review summarizes the most significant and up-to-date in vitro and in vivo neuroprotective actions of sulforaphane (SFN), moringin (MG), phenethyl isothiocyanate (PEITC), 6-(methylsulfinyl) hexyl isothiocyanate (6-MSITC) and erucin (ER) in neurodegenerative diseases.

One-Time Pad as a nonlinear dynamical system

NASA Astrophysics Data System (ADS)

Nagaraj, Nithin

2012-11-01

The One-Time Pad (OTP) is the only known unbreakable cipher, proved mathematically by Shannon in 1949. In spite of several practical drawbacks of using the OTP, it continues to be used in quantum cryptography, DNA cryptography and even in classical cryptography when the highest form of security is desired (other popular algorithms like RSA, ECC, AES are not even proven to be computationally secure). In this work, we prove that the OTP encryption and decryption is equivalent to finding the initial condition on a pair of binary maps (Bernoulli shift). The binary map belongs to a family of 1D nonlinear chaotic and ergodic dynamical systems known as Generalized Luröth Series (GLS). Having established these interesting connections, we construct other perfect secrecy systems on the GLS that are equivalent to the One-Time Pad, generalizing for larger alphabets. We further show that OTP encryption is related to Randomized Arithmetic Coding - a scheme for joint compression and encryption.

Leaf Metabolic, Genetic, and Morphophysiological Profiles of Cultivated and Wild Rocket Salad (Eruca and Diplotaxis Spp.).

PubMed

Taranto, Francesca; Francese, Gianluca; Di Dato, Francesco; D'Alessandro, Antonietta; Greco, Barbara; Onofaro Sanajà, Vincenzo; Pentangelo, Alfonso; Mennella, Giuseppe; Tripodi, Pasquale

2016-07-27

Rocket salad (Diplotaxis spp., Eruca spp.) is a leafy vegetable rich in health-promoting compounds and widely consumed. In the present study, metabolic profiles of 40 rocket accessions mainly retrieved from gene banks were assessed. Seven glucosinolates (GLSs) and 15 flavonol compounds were detected across genotypes. Dimeric 4-mercaptobutyl-GLS and 4-(β-d-glucopyranosyldisulfanyl)butyl-GLS were the major components of the total glucosinolate content. Flavonols were different between genera, with the exception of isorhamnetin 3,4'-diglucoside. Morphoagronomic traits and color coordinates were also scored. Results showed a negative correlation between color and GLSs, indicating these last as responsible for the increase of the intensity of green and yellow pigments as well as for the darkness of the leaf, whereas agronomic traits showed positive correlation with GLSs. Genetic diversity was assessed using inter simple sequence repeat (ISSR) markers, allowing separation of the accessions on the basis of the species and elucidating the observations made by means of phenotypic data.

RNA:RNA interaction can enhance RNA localization in Drosophila oocytes

PubMed Central

Hartswood, Eve; Brodie, Jim; Vendra, Georgia; Davis, Ilan; Finnegan, David J.

2012-01-01

RNA localization is a key mechanism for targeting proteins to particular subcellular domains. Sequences necessary and sufficient for localization have been identified, but little is known about factors that affect its kinetics. Transcripts of gurken and the I factor, a non-LTR retrotransposon, colocalize at the nucleus in the dorso–antero corner of the Drosophila oocyte directed by localization signals, the GLS and ILS. I factor RNA localizes faster than gurken after injection into oocytes, due to a difference in the intrinsic localization ability of the GLS and ILS. The kinetics of localization of RNA containing the ILS are enhanced by the presence of a stem–loop, the A loop. This acts as an RNA:RNA interaction element in vivo and in vitro, and stimulates localization of RNA containing other localization signals. RNA:RNA interaction may be a general mechanism for modulating RNA localization and could allow an mRNA that lacks a localization signal to hitchhike on another RNA that has one. PMID:22345148

Evaluation of the streamflow-gaging network of Alaska in providing regional streamflow information

USGS Publications Warehouse

Brabets, Timothy P.

1996-01-01

In 1906, the U.S. Geological Survey (USGS) began operating a network of streamflow-gaging stations in Alaska. The primary purpose of the streamflow- gaging network has been to provide peak flow, average flow, and low-flow characteristics to a variety of users. In 1993, the USGS began a study to evaluate the current network of 78 stations. The objectives of this study were to determine the adequacy of the existing network in predicting selected regional flow characteristics and to determine if providing additional streamflow-gaging stations could improve the network's ability to predict these characteristics. Alaska was divided into six distinct hydrologic regions: Arctic, Northwest, Southcentral, Southeast, Southwest, and Yukon. For each region, historical and current streamflow data were compiled. In Arctic, Northwest, and Southwest Alaska, insufficient data were available to develop regional regression equations. In these areas, proposed locations of streamflow-gaging stations were selected by using clustering techniques to define similar areas within a region and by spatial visual analysis using the precipitation, physiographic, and hydrologic unit maps of Alaska. Sufficient data existed in Southcentral and Southeast Alaska to use generalized least squares (GLS) procedures to develop regional regression equations to estimate the 50-year peak flow, annual average flow, and a low-flow statistic. GLS procedures were also used for Yukon Alaska but the results should be used with caution because the data do not have an adequate spatial distribution. Network analysis procedures were used for the Southcentral, Southeast, and Yukon regions. Network analysis indicates the reduction in the sampling error of the regional regression equation that can be obtained given different scenarios. For Alaska, a 10-year planning period was used. One scenario showed the results of continuing the current network with no additional gaging stations and another scenario showed the results of adding gaging stations to the network. With the exception of the annual average discharge equation for Southeast Alaska, by adding gaging stations in all three regions, the sampling error was reduced to a greater extent than by not adding gaging stations. The proposed streamflow-gaging network for Alaska consists of 308 gaging stations, of which 32 are designated as index stations. If the proposed network can not be implemented in its entirety, then a lesser cost alternative would be to establish the index stations and to implement the network for a particular region.

Specific Glucoside Transporters Influence Septal Structure and Function in the Filamentous, Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120.

PubMed

Nieves-Morión, Mercedes; Lechno-Yossef, Sigal; López-Igual, Rocío; Frías, José E; Mariscal, Vicente; Nürnberg, Dennis J; Mullineaux, Conrad W; Wolk, C Peter; Flores, Enrique

2017-04-01

When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO 2 through oxygenic photosynthesis and heterocysts that are specialized in N 2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the α-glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are an ATP-binding subunit and a permease subunit of two different ABC transporters, respectively, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for the formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena , glucoside transporters influence the structure and function of septal junctions. IMPORTANCE Heterocyst-forming cyanobacteria have the ability to perform oxygenic photosynthesis and to assimilate atmospheric CO 2 and N 2 These organisms grow as filaments that fix these gases specifically in vegetative cells and heterocysts, respectively. For the filaments to grow, these types of cells exchange nutrients, including sucrose, which serves as a source of reducing power and of carbon skeletons for the heterocysts. Movement of sucrose between cells in the filament takes place through septal junctions and has been traced with a fluorescent sucrose analog, esculin, that can be taken up by the cells. Here, we identified α-glucoside transporters of Anabaena that mediate uptake of esculin and, notably, influence septal structure and the function of septal junctions. Copyright © 2017 American Society for Microbiology.

Specific Glucoside Transporters Influence Septal Structure and Function in the Filamentous, Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

PubMed Central

Nieves-Morión, Mercedes; Lechno-Yossef, Sigal; López-Igual, Rocío; Frías, José E.; Mariscal, Vicente; Nürnberg, Dennis J.; Mullineaux, Conrad W.; Wolk, C. Peter

2017-01-01

ABSTRACT When deprived of combined nitrogen, some filamentous cyanobacteria contain two cell types: vegetative cells that fix CO2 through oxygenic photosynthesis and heterocysts that are specialized in N2 fixation. In the diazotrophic filament, the vegetative cells provide the heterocysts with reduced carbon (mainly in the form of sucrose) and heterocysts provide the vegetative cells with combined nitrogen. Septal junctions traverse peptidoglycan through structures known as nanopores and appear to mediate intercellular molecular transfer that can be traced with fluorescent markers, including the sucrose analog esculin (a coumarin glucoside) that is incorporated into the cells. Uptake of esculin by the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 was inhibited by the α-glucosides sucrose and maltose. Analysis of Anabaena mutants identified components of three glucoside transporters that move esculin into the cells: GlsC (Alr4781) and GlsP (All0261) are an ATP-binding subunit and a permease subunit of two different ABC transporters, respectively, and HepP (All1711) is a major facilitator superfamily (MFS) protein that was shown previously to be involved in formation of the heterocyst envelope. Transfer of fluorescent markers (especially calcein) between vegetative cells of Anabaena was impaired by mutation of glucoside transporter genes. GlsP and HepP interact in bacterial two-hybrid assays with the septal junction-related protein SepJ, and GlsC was found to be necessary for the formation of a normal number of septal peptidoglycan nanopores and for normal subcellular localization of SepJ. Therefore, beyond their possible role in nutrient uptake in Anabaena, glucoside transporters influence the structure and function of septal junctions. IMPORTANCE Heterocyst-forming cyanobacteria have the ability to perform oxygenic photosynthesis and to assimilate atmospheric CO2 and N2. These organisms grow as filaments that fix these gases specifically in vegetative cells and heterocysts, respectively. For the filaments to grow, these types of cells exchange nutrients, including sucrose, which serves as a source of reducing power and of carbon skeletons for the heterocysts. Movement of sucrose between cells in the filament takes place through septal junctions and has been traced with a fluorescent sucrose analog, esculin, that can be taken up by the cells. Here, we identified α-glucoside transporters of Anabaena that mediate uptake of esculin and, notably, influence septal structure and the function of septal junctions. PMID:28096449

HOTEX: An Approach for Global Mapping of Human Built-Up and Settlement Extent

NASA Technical Reports Server (NTRS)

Wang, Panshi; Huang, Chengquan; Tilton, James C.; Tan, Bin; Brown De Colstoun, Eric C.

2017-01-01

Understanding the impacts of urbanization requires accurate and updatable urban extent maps. Here we present an algorithm for mapping urban extent at global scale using Landsat data. An innovative hierarchical object-based texture (HOTex) classification approach was designed to overcome spectral confusion between urban and nonurban land cover types. VIIRS nightlights data and MODIS vegetation index datasets are integrated as high-level features under an object-based framework. We applied the HOTex method to the GLS-2010 Landsat images to produce a global map of human built-up and settlement extent. As shown by visual assessments, our method could effectively map urban extent and generate consistent results using images with inconsistent acquisition time and vegetation phenology. Using scene-level cross validation for results in Europe, we assessed the performance of HOTex and achieved a kappa coefficient of 0.91, compared to 0.74 from a baseline method using per-pixel classification using spectral information.

76 FR 21339 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-15

...- tetramethyldisil tetramethyl-* oxane--see gls138; reducing agent for organic substrates, e.g. pharmaceutical... Specialties, Inc. (G) Flame (G) Organic-N,P- retardant for compound incorporation into polymer resins (open...) Organic-N,P- retardant for compound incorporation into polymer resins (open non- dispersive use). P-11...

Math for Success in Electronics. Instructor's Guide. Reference Manual.

ERIC Educational Resources Information Center

DeVantier, Connie; And Others

This document contains both an instructor's guide and a reference manual. It was developed as part of a cooperative venture between Industrial Technology Institute (ITI), Wayne County (Michigan) Community College, and Great Lakes Steel (GLS). The instructor's guide has four sections: math for success in electronics, student materials, electronics…

Early detection of airborne inoculum of Magnaporthe oryzae in turfgrass fields using a quantitative LAMP assay

USDA-ARS?s Scientific Manuscript database

Gray leaf spot (GLS) is a destructive disease of perennial ryegrass caused by a host specific pathotype of the ascomycete Magnaporthe oryzae. Early diagnosis is crucial for effective disease management and the implementation of Integrated Pest Management practices. However, a rapid diagnostic protoc...

A maize caffeoyl-CoA O-methyltransferase gene confers quantitative resistance to multiple pathogens

USDA-ARS?s Scientific Manuscript database

Alleles that confer multiple disease resistance (MDR) are valuable in crop improvement though molecular mechanisms underlying their functions remain largely unknown. A QTL, qMdr9.02, associated with resistance to three important foliar maize diseases, southern leaf blight (SLB), gray leaf spot (GLS)...

Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction?

PubMed

Lima, Marcio Silva Miguel; Villarraga, Hector R; Abduch, Maria Cristina Donadio; Lima, Marta Fernandes; Cruz, Cecilia Beatriz Bittencourt Viana; Sbano, João Cesar Nunes; Voos, Mariana Callil; Mathias, Wilson; Tsutsui, Jeane Mike

2017-07-01

Estimative of left ventricular ejection fraction (LVEF) is a major indication for echocardiography. Speckle tracking echocardiography (STE) allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS) and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before. This study aims to check which one has the highest correlation with LVEF. Patients with normal LVEF (> 0,55) and systolic dysfunction (LVEF <0,55) were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested. A total of 131 patients were included (mean age, 46 ± 14y; 43%, men). LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001), more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001). Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001); torsion (r = 0.75; r2 = 0.56; p < 0.001). GLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS. A estimativa da fração de ejeção do ventrículo esquerdo (FEVE) é uma das pincipais indicações para a ecocardiografia. Speckle tracking (ST) permite a análise da mecânica de contração do VE que inclui a deformação (strain) longitudinal global (SLG) e o twist / torção, sendo ambos os mais utilizados. A comparação direta de correlações entre esses novos parâmetros e a FEVE nunca foi feita antes. Verificar qual delas tem a maior correlação com a FEVE. Pacientes com FEVE normal (> 0,55) e disfunção sistólica (FEVE < 0,55) foram prospectivamente inscritos e submetidos a ecocardiograma com análise do ST. A correlação das variáveis foi realizada por análise de regressão linear. Além disso, também foi testada a correlação entre os níveis de comprometimento sistólico do VE. Foram incluídos 131 pacientes (média de idade de 46 ± 14 anos e 43% de homens). A FEVE e SLG apresentaram forte correlação (r = 0,95; r2 = 0,89; p < 0,001), mais evidente em grupos com disfunção sistólica do VE do que naqueles com FEVE preservada. Também foi encontrada boa correlação com a taxa de deformação (strain rate) longitudinal (SRL) global (r = 0,85; r2 = 0,73; p < 0,001). Comparando-a à SLG, a correlação entre FEVE e mecânica de torção foi mais fraca: twist (r = 0,78; r2 = 0,60; p < 0,001); Torção (r = 0,75, r2 = 0,56, p < 0,001). A SLG do ventrículo esquerdo apresenta alta correlação positiva com o parâmetro clássico de fração de ejeção, principalmente nos casos de comprometimento sistólico do VE. O SRL também demonstrou uma boa correlação. A SLG incrementa a análise da função sistólica do VE. Por outro lado, apesar de ser a pedra angular da mecânica do VE, o twist e a torção têm uma correlação mais fraca com a ejeção do VE, quando comparados ao SLG.

Sociopolitical and economic elements to explain the environmental performance of countries.

PubMed

Almeida, Thiago Alexandre das Neves; García-Sánchez, Isabel-María

2017-01-01

The present research explains environmental performance using an ecological composite index as the dependent variable and focusing on two national dimensions: sociopolitical characteristics and economics. Environmental performance is measured using the Composite Index of Environmental Performance (CIEP) indicator proposed by García-Sánchez et al. (2015). The first model performs a factor analysis to aggregate the variables according to each analyzed dimension. In the second model, the estimation is run using only single variables. Both models are estimated using generalized least square estimation (GLS) using panel data from 152 countries and 6 years. The results show that sociopolitical factors and international trade have a positive effect on environmental performance. When the variables are separately analyzed, democracy and social policy have a positive effect on environmental performance while transport, infrastructure, consumption of goods, and tourism have a negative effect. Further observation is that the trade-off between importing and exporting countries overshadows the pollution caused by production. It was also observed that infrastructure has a negative coefficient for developing countries and positive for developed countries. The best performances are in the democratic and richer countries that are located in Europe, while the worst environmental performance is by the nondemocratic and the poorest countries, which are on the African continent.

Monitoring cotton root rot by synthetic Sentinel-2 NDVI time series using improved spatial and temporal data fusion.

PubMed

Wu, Mingquan; Yang, Chenghai; Song, Xiaoyu; Hoffmann, Wesley Clint; Huang, Wenjiang; Niu, Zheng; Wang, Changyao; Li, Wang; Yu, Bo

2018-01-31

To better understand the progression of cotton root rot within the season, time series monitoring is required. In this study, an improved spatial and temporal data fusion approach (ISTDFA) was employed to combine 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Different Vegetation Index (NDVI) and 10-m Sentinetl-2 NDVI data to generate a synthetic Sentinel-2 NDVI time series for monitoring this disease. Then, the phenology of healthy cotton and infected cotton was modeled using a logistic model. Finally, several phenology parameters, including the onset day of greenness minimum (OGM), growing season length (GLS), onset of greenness increase (OGI), max NDVI value, and integral area of the phenology curve, were calculated. The results showed that ISTDFA could be used to combine time series MODIS and Sentinel-2 NDVI data with a correlation coefficient of 0.893. The logistic model could describe the phenology curves with R-squared values from 0.791 to 0.969. Moreover, the phenology curve of infected cotton showed a significant difference from that of healthy cotton. The max NDVI value, OGM, GSL and the integral area of the phenology curve for infected cotton were reduced by 0.045, 30 days, 22 days, and 18.54%, respectively, compared with those for healthy cotton.

Conversion of canola meal into a high-protein feed additive via solid-state fungal incubation process

USDA-ARS?s Scientific Manuscript database

The study goal was to determine the optimal fungal culture to reduce glucosinolates (GLS), fiber, and residual sugars while increasing the protein content and nutritional value of canola meal. Solid-state incubation conditions were used to enhance filamentous growth of the fungi. Flask trials were p...

78 FR 50110 - Notice of Lodging Proposed Consent Decree

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... Enterprises, Inc., Civil Action No. 5:13-cv-916 (GLS/DEP) was lodged with the United States District Court for... impose civil penalties against the Defendants for violating the Clean Water Act by discharging pollutants... by requiring the Defendants to restore and monitor the impacted areas and to pay a civil penalty. The...

Systems genetics reveals a transcriptional network associated with susceptibility in the maize-grey leaf spot pathosystem

USDA-ARS?s Scientific Manuscript database

We have applied a systems genetics approach to elucidate molecular mechanisms of maize responses to gray leaf spot (GLS) disease, caused by Cercospora zeina, a major threat to maize production globally. We conducted expression QTL (eQTL) analysis of gene expression variation measured in earleaf samp...

Glutamine promotes ovarian cancer cell proliferation through the mTOR/S6 pathway

PubMed Central

Yuan, Lingqin; Sheng, Xiugui; Willson, Adam K; Roque, Dario R; Stine, Jessica E; Guo, Hui; Jones, Hannah M; Zhou, Chunxiao; Bae-Jump, Victoria L

2015-01-01

Glutamine is one of the main nutrients used by tumor cells for biosynthesis. Therefore, targeted inhibition of glutamine metabolism may have anti-tumorigenic implications. In the present study, we aimed to evaluate the effects of glutamine on ovarian cancer cell growth. Three ovarian cancer cell lines, HEY, SKOV3, and IGROV-1, were assayed for glutamine dependence by analyzing cytotoxicity, cell cycle progression, apoptosis, cell stress, and glucose/glutamine metabolism. Our results revealed that administration of glutamine increased cell proliferation in all three ovarian cancer cell lines in a dose dependent manner. Depletion of glutamine induced reactive oxygen species and expression of endoplasmic reticulum stress proteins. In addition, glutamine increased the activity of glutaminase (GLS) and glutamate dehydrogenase (GDH) by modulating the mTOR/S6 and MAPK pathways. Inhibition of mTOR activity by rapamycin or blocking S6 expression by siRNA inhibited GDH and GLS activity, leading to a decrease in glutamine-induced cell proliferation. These studies suggest that targeting glutamine metabolism may be a promising therapeutic strategy in the treatment of ovarian cancer. PMID:26045471

Cardiorespiratory fitness modifies the relationship between myocardial function and cerebral blood flow in older adults.

PubMed

Johnson, Nathan F; Gold, Brian T; Bailey, Alison L; Clasey, Jody L; Hakun, Jonathan G; White, Matthew; Long, Doug E; Powell, David K

2016-05-01

A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in myocardial functions affecting cerebral blood flow (CBF). This study explored the relationship between a measure of myocardial mechanics, global longitudinal strain (GLS), and CBF to the DMN. In addition, we explored how cardiorespiratory affects this relationship. Participants were 30 older adults between the ages of 59 and 69 (mean age=63.73years, SD=2.8). Results indicated that superior cardiorespiratory fitness and myocardial mechanics were positively associated with DMN CBF. Moreover, results of a mediation analysis revealed that the relationship between GLS and DMN CBF was accounted for by individual differences in fitness. Findings suggest that benefits of healthy heart function to brain function are modified by fitness. Copyright © 2015 Elsevier Inc. All rights reserved.

A novel role for Gtb1p in glucose trimming of N-linked glycans

PubMed Central

Quinn, Robert P; Mahoney, Sarah J; Wilkinson, Barrie M; Thornton, David J; Stirling, Colin J

2009-01-01

Glucosidase II (GluII) is a glycan-trimming enzyme active on nascent glycoproteins in the endoplasmic reticulum (ER). It trims the middle and innermost glucose residues (Glc2 and Glc1) from N-linked glycans. The monoglucosylated glycan produced by the first GluII trimming reaction is recognized by calnexin/calreticulin and serves as the signal for entry into this folding pathway. GluII is a heterodimer of α and β subunits corresponding to yeast Gls2p and Gtb1p, respectively. While Gls2p contains the glucosyl hydrolase active site, the Gtb1p subunit has previously been shown to be essential for the Glc1 trimming event. Here we demonstrate that Gtb1p also determines the rate of Glc2 trimming. In order to further dissect these activities we mutagenized a number of conserved residues across the protein. Our data demonstrate that both the MRH and G2B domains of Gtb1p contribute to the Glc2 trimming event but that the MRH domain is essential for Glc1 trimming. PMID:19542522

Right Ventricular Structure and Function in Idiopathic Pulmonary Fibrosis with or without Pulmonary Hypertension.

PubMed

D'Andrea, Antonello; Stanziola, Anna; Di Palma, Enza; Martino, Maria; D'Alto, Michele; Dellegrottaglie, Santo; Cocchia, Rosangela; Riegler, Lucia; Betancourt Cordido, Meredyth Vanessa; Lanza, Maurizia; Maglione, Marco; Diana, Veronica; Calabrò, Raffaele; Russo, Maria Giovanna; Vannan, Mani; Bossone, Eduardo

2016-01-01

To elucidate right ventricular (RV) function in patients with idiopathic pulmonary fibrosis (IPF) with and without pulmonary hypertension (PH) and its relation to other features of the disease. Clinical evaluation, standard Doppler echo, Doppler myocardial imaging (DMI), and 2D strain echocardiography (STE) of RV septal and lateral walls were performed in 52 IPF patients (66.5 ± 8.5 years; 27 males) and in 45 age- and sex-comparable controls using a commercial US system (MyLab Alpha, Esaote). Pulmonary artery mean pressure (mPAP) was estimated by standard echo Doppler. RV global longitudinal strain (RV GLS) was calculated by averaging RV local strains. The IPF patients were divided into 2 groups by noninvasive assessment of PH: no PH (mPAP<25 mmHg; 36 pts) and PH (mPAP ≥25 mmHg; 16 pts). Left ventricular diameters and ejection fraction were comparable between controls and IPF, while GLS was impaired in IPF (P < 0.01). RV end-diastolic diameters, wall thickness andmPAP were increased in IPF patients with PH. In addition, pulsed DMI detected in PH IPF impaired myocardial RV early diastolic (Em) peak velocity. Also peak systolic RV strain was reduced in basal and middle RV lateral free walls in IPF, as well as RV GLS (P < 0.0001). The impairment in RV wall strain was more evident when comparing controls with the no PH group than comparing the no PH group with the PH group. By multivariate analysis, independent association of RV strain with both six-minute walking test distance (P < 0.001), mPAP (P < 0.0001), as well as with forced vital capacity (FVC) % (P < 0.005) in IPF patients were observed. Impaired RV diastolic and systolic myocardial function were present even in IPF patients without PH, which indicates an early impact on RV function and structure in patients with IPF. © 2015, Wiley Periodicals, Inc.

The receptor tyrosine kinase EphA2 promotes glutamine metabolism in tumors by activating the transcriptional coactivators YAP and TAZ.

PubMed

Edwards, Deanna N; Ngwa, Verra M; Wang, Shan; Shiuan, Eileen; Brantley-Sieders, Dana M; Kim, Laura C; Reynolds, Albert B; Chen, Jin

2017-12-05

Malignant tumors reprogram cellular metabolism to support cancer cell proliferation and survival. Although most cancers depend on a high rate of aerobic glycolysis, many cancer cells also display addiction to glutamine. Glutamine transporters and glutaminase activity are critical for glutamine metabolism in tumor cells. We found that the receptor tyrosine kinase EphA2 activated the TEAD family transcriptional coactivators YAP and TAZ (YAP/TAZ), likely in a ligand-independent manner, to promote glutamine metabolism in cells and mouse models of HER2-positive breast cancer. Overexpression of EphA2 induced the nuclear accumulation of YAP and TAZ and increased the expression of YAP/TAZ target genes. Inhibition of the GTPase Rho or the kinase ROCK abolished EphA2-dependent YAP/TAZ nuclear localization. Silencing YAP or TAZ substantially reduced the amount of intracellular glutamate through decreased expression of SLC1A5 and GLS , respectively, genes that encode proteins that promote glutamine uptake and metabolism. The regulatory DNA elements of both SLC1A5 and GLS contain TEAD binding sites and were bound by TEAD4 in an EphA2-dependent manner. In patient breast cancer tissues, EphA2 expression positively correlated with that of YAP and TAZ , as well as that of GLS and SLC1A5 Although high expression of EphA2 predicted enhanced metastatic potential and poor patient survival, it also rendered HER2-positive breast cancer cells more sensitive to glutaminase inhibition. The findings define a previously unknown mechanism of EphA2-mediated glutaminolysis through YAP/TAZ activation in HER2-positive breast cancer and identify potential therapeutic targets in patients. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Reprogramming of proline and glutamine metabolism contributes to the proliferative and metabolic responses regulated by oncogenic transcription factor c-MYC

PubMed Central

Liu, Wei; Le, Anne; Hancock, Chad; Lane, Andrew N.; Dang, Chi V.; Fan, Teresa W.-M.; Phang, James M.

2012-01-01

In addition to glycolysis, the oncogenic transcription factor c-MYC (MYC) stimulates glutamine catabolism to fuel growth and proliferation of cancer cells through up-regulating glutaminase (GLS). Glutamine is converted to glutamate by GLS, entering the tricarboxylic acid cycle as an important energy source. Less well-recognized, glutamate can also be converted to proline through Δ1-pyrroline-5-carboxylate (P5C) and vice versa. This study suggests that some MYC-induced cellular effects are due to MYC regulation of proline metabolism. Proline oxidase, also known as proline dehydrogenase (POX/PRODH), the first enzyme in proline catabolism, is a mitochondrial tumor suppressor that inhibits proliferation and induces apoptosis. MiR-23b* mediates POX/PRODH down-regulation in human kidney tumors. MiR-23b* is processed from the same transcript as miR-23b; the latter inhibits the translation of GLS. Using MYC-inducible human Burkitt lymphoma model P493 and PC3 human prostate cancer cells, we showed that MYC suppressed POX/PRODH expression primarily through up-regulating miR-23b*. The growth inhibition in the absence of MYC was partially reversed by POX/PRODH knockdown, indicating the importance of suppression of POX/PRODH in MYC-mediated cellular effects. Interestingly, MYC not only inhibited POX/PRODH, but also markedly increased the enzymes of proline biosynthesis from glutamine, including P5C synthase and P5C reductase 1. MYC-induced proline biosynthesis from glutamine was directly confirmed using 13C,15N-glutamine as a tracer. The metabolic link between glutamine and proline afforded by MYC emphasizes the complexity of tumor metabolism. Further studies of the relationship between glutamine and proline metabolism should provide a deeper understanding of tumor metabolism while enabling the development of novel therapeutic strategies. PMID:22615405

Gestational changes in left ventricular myocardial contractile function: new insights from two-dimensional speckle tracking echocardiography.

PubMed

Sengupta, Shantanu P; Bansal, Manish; Hofstra, Leonard; Sengupta, Partho P; Narula, Jagat

2017-01-01

The goal of this study was to evaluate the impact of pregnancy and labor on left ventricular (LV) myocardial mechanics using speckle tracking echocardiography (STE). Pregnancy is characterized by profound hormonal and hemodynamic alterations that directly or indirectly influence cardiac structure and function. However, the impact of these changes on left ventricular (LV) myocardial contractile function has not been fully elucidated. In this prospective, longitudinal study, 35 pregnant women underwent serial clinical and echocardiographic evaluation during each trimester and at labor. Two dimensional STE was performed to measure global LV longitudinal, circumferential and radial strain (GLS, GCS and GRS, respectively). Similar data obtained from 20 nulliparous, age-matched women were used as control. All strain values during pregnancy were adjusted for age and hemodynamic parameters. There was a progressive increase in heart rate, systolic and diastolic blood pressure, cardiac output and LV stroke-work during pregnancy. LV end-diastolic and end-systolic volumes also increased progressively but LV ejection fraction remained unaltered, except for slight reduction during the second trimester. Compared to the controls, GLS and GCS were reduced in the first trimester itself (GLS -22.39 ± 5.43 % vs. -18.66 ± 0.64 %, P 0.0002; GCS -20.84 ± 3.20 vs. -17.88 ± 0.09, P < 0.001) and remained so throughout the pregnancy and labor. In contrast, GRS showed an increase during pregnancy which peaked during the second trimester (24.18 ± 0.39 % vs. 18.06 ± 8.14 % in controls, P < 0.001). Alterations in loading conditions during pregnancy are associated with counterbalancing changes in the myocardial mechanics. LV longitudinal and circumferential strain are reduced whereas radial strain is increased. These counterbalancing changes serve to maintain overall LV ejection performance within a normal range and enable the maternal heart to meet the hemodynamic demands of pregnancy and labor.

Baicalin effects on rats with spinal cord injury by anti-inflammatory and regulating the serum metabolic disorder.

PubMed

Kang, Shufeng; Liu, Shizhao; Li, Hongzhu; Wang, Dapeng; Qi, Xiangbei

2018-06-15

Baicalin had neuroprotective effects on inhibiting neuronal cell apoptosis induced by spinal cord ischemic injury. This study aimed to explore the protective effects of Baicalin on rats with spinal cord injury (SCI) and its mechanism of action. The recovery of spinal cord nerve function in rats was evaluated by the Basso, Beattie, and Bresnahan (BBB) score and the combine behavioral score (CBS). The expressions of cytokines tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 were detected by the enzyme-linked immunosorbent assay method. Expressions of inflammation-related proteins were detected by Western blot. Multivariate statistical analysis was performed for serum metabolites. The BBB and CBS score results showed that Baicalin had a certain improvement on rats with SCI. SCI symptoms were significantly improved in low-dose and high-dose groups. The levels of TNF-α, IL-1β, and IL-6 in the SCI group were significantly increased. The expressions of NF-κB p65, NF-κB p50, p-IκBα, and IKKα in the SCI group showed the opposite trend compared with the low-dose and high-dose groups. Compared with the sham group, glutamine, levels of 3-OH-butyrate, N-acetylaspartate, and glutathione were significantly reduced, and the levels of glutamate and betaine were significantly increased in the SCI group. When Baicalin was administered, the contents of glutamine synthase (GS) and glutaminase (GLS) were significantly reduced, indicating that Baicalin had the effect of improving GS and GLS. Baicalin has protective effects on improving SCI and lower extremity motor function, has a significant anti-inflammatory effect, and regulates the serum metabolic disorder caused by SCI in rats. © 2018 Wiley Periodicals, Inc.

Ambient-Temperature Trap/Release of Arsenic by Dielectric Barrier Discharge and Its Application to Ultratrace Arsenic Determination in Surface Water Followed by Atomic Fluorescence Spectrometry.

PubMed

Mao, Xuefei; Qi, Yuehan; Huang, Junwei; Liu, Jixin; Chen, Guoying; Na, Xing; Wang, Min; Qian, Yongzhong

2016-04-05

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge.

THE E2/FRB PATHWAY REGULATION OF DNA REPLICATION AND PROTEIN BIOSYNTHESIS

EPA Science Inventory

The E2F/Rb pathway plays a pivotal role in the control of cell cycle progression and regulates the expression of genes required for Gl/S transition. Our study examines the genomic response in Drosophila embryos after overexpression and mutation of E2F/Rb pathway molecules. Hierar...

Development of a quantitative loop-mediated isothermal amplification (qLAMP) assay for the detection of Magnaporthe oryzae airborne inoculum in turf ecosystems

USDA-ARS?s Scientific Manuscript database

Grey Leaf Spot (GLS) is a detrimental disease of perennial ryegrass caused by a host-specialized form of Magnaporthe oryzae (Mot). In order to improve turf management, a quantitative loop-mediated isothermal amplification (LAMP) assay coupled with a simple spore trap is being developed to monitor GL...

Integrated lab-in-syringe platform incorporating a membraneless gas-liquid separator for automatic cold vapor atomic absorption spectrometry.

PubMed

Giakisikli, Georgia; Miró, Manuel; Anthemidis, Aristidis

2013-10-01

This manuscript reports the proof-of-concept of a novel integrated lab-in-syringe/gas-liquid separation (LIS/GLS) batch-flow system based on a programmable flow for automatic cold vapor atomic absorption spectrometric assays. Homogeneous mixing of metered volumes of sample and reagent solutions drawn up in a sandwich-type mode along with in situ vapor generation are accomplished inside the microsyringe in a closed manner, while the separation of vapor species is achieved via the membraneless GLS located at the top of the syringe's valve in the upright position. The potentials of the proposed manifold were demonstrated for trace inorganic mercury determination in drinking waters and seawater. For a 3.0 mL sample, the limit of detection and repeatability (RSD) were found to be 0.03 μg L(-1) Hg(II) and 3.1% (at the 2.0 μg L(-1) concentration level), respectively, with a dynamic range extending up to 10.0 μg L(-1). The proposed system fulfills the requirements of US-EPA, WHO, and EU Council Directives for measurements of the maximum allowed concentrations of inorganic mercury in drinking water.

GLD-4-Mediated Translational Activation Regulates the Size of the Proliferative Germ Cell Pool in the Adult C. elegans Germ Line

PubMed Central

Millonigg, Sophia; Eckmann, Christian R.

2014-01-01

To avoid organ dysfunction as a consequence of tissue diminution or tumorous growth, a tight balance between cell proliferation and differentiation is maintained in metazoans. However, cell-intrinsic gene expression mechanisms controlling adult tissue homeostasis remain poorly understood. By focusing on the adult Caenorhabditis elegans reproductive tissue, we show that translational activation of mRNAs is a fundamental mechanism to maintain tissue homeostasis. Our genetic experiments identified the Trf4/5-type cytoplasmic poly(A) polymerase (cytoPAP) GLD-4 and its enzymatic activator GLS-1 to perform a dual role in regulating the size of the proliferative zone. Consistent with a ubiquitous expression of GLD-4 cytoPAP in proliferative germ cells, its genetic activity is required to maintain a robust proliferative adult germ cell pool, presumably by regulating many mRNA targets encoding proliferation-promoting factors. Based on translational reporters and endogenous protein expression analyses, we found that gld-4 activity promotes GLP-1/Notch receptor expression, an essential factor of continued germ cell proliferation. RNA-protein interaction assays documented also a physical association of the GLD-4/GLS-1 cytoPAP complex with glp-1 mRNA, and ribosomal fractionation studies established that GLD-4 cytoPAP activity facilitates translational efficiency of glp-1 mRNA. Moreover, we found that in proliferative cells the differentiation-promoting factor, GLD-2 cytoPAP, is translationally repressed by the stem cell factor and PUF-type RNA-binding protein, FBF. This suggests that cytoPAP-mediated translational activation of proliferation-promoting factors, paired with PUF-mediated translational repression of differentiation factors, forms a translational control circuit that expands the proliferative germ cell pool. Our additional genetic experiments uncovered that the GLD-4/GLS-1 cytoPAP complex promotes also differentiation, forming a redundant translational circuit with GLD-2 cytoPAP and the translational repressor GLD-1 to restrict proliferation. Together with previous findings, our combined data reveals two interconnected translational activation/repression circuitries of broadly conserved RNA regulators that maintain the balance between adult germ cell proliferation and differentiation. PMID:25254367

Advancement of Systems Designs and Key Engineering Technologies for Materials Based Hydrogen Storage

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

van Hassel, Bart A.

UTRC lead the development of the Simulink Framework model that enables a comparison of different hydrogen storage systems on a common basis. The Simulink Framework model was disseminated on the www.HSECoE.org website that is hosted by NREL. UTRC contributed to a better understanding of the safety aspects of the proposed hydrogen storage systems. UTRC also participated in the Failure Mode and Effect Analysis of both the chemical- and the adsorbent-based hydrogen storage system during Phase 2 of the Hydrogen Storage Engineering Center of Excellence. UTRC designed a hydrogen storage system with a reversible metal hydride material in a compacted formmore » for light-duty vehicles with a 5.6 kg H2 storage capacity, giving it a 300 miles range. It contains a heat exchanger that enables efficient cooling of the metal hydride material during hydrogen absorption in order to meet the 3.3 minute refueling time target. It has been shown through computation that the kinetics of hydrogen absorption of Ti-catalyzed NaAlH4 was ultimately limiting the rate of hydrogen absorption to 85% of the material capacity in 3.3 minutes. An inverse analysis was performed in order to determine the material property requirements in order for a metal hydride based hydrogen storage system to meet the DOE targets. Work on metal hydride storage systems was halted after the Phase 1 to Phase 2 review due to the lack of metal hydride materials with the required material properties. UTRC contributed to the design of a chemical hydrogen storage system by developing an adsorbent for removing the impurity ammonia from the hydrogen gas, by developing a system to meter the transport of Ammonia Borane (AB) powder to a thermolysis reactor, and by developing a gas-liquid-separator (GLS) for the separation of hydrogen gas from AB slurry in silicone oil. Stripping impurities from hydrogen gas is essential for a long life of the fuel cell system on board of a vehicle. Work on solid transport of AB was halted after the Phase 1 to Phase 2 review in favor of studying the slurry-form of AB as it appeared to be difficult to transport a solid form of AB through the thermolysis reactor. UTRC demonstrated the operation of a compact GLS in the laboratory at a scale that would be required for the actual automotive application. The GLS met the targets for weight and volume. UTRC also reported about the unresolved issue associated with the high vapor pressure of fluids that could be used for making a slurry-form of AB. Work on the GLS was halted after the Phase 2 to Phase 3 review as the off-board regeneration efficiency of the spent AB was below the DOE target of 60%. UTRC contributed to the design of an adsorbent-based hydrogen storage system through measurements of the thermal conductivity of a compacted form of Metal Organic Framework (MOF) number 5 and through the development and sizing of a particulate filter. Thermal conductivity is important for the design of the modular adsorbent tank insert (MATI), as developed by Oregon State University (OSU), in order to enable a rapid refueling process. Stringent hydrogen quality requirements can only be met with an efficient particulate filtration system. UTRC developed a method to size the particulate filter by taking into account the effect of the pressure drop on the hydrogen adsorption process in the tank. UTRC raised awareness about the potential use of materials-based H2 storage systems in applications outside the traditional light-duty vehicle market segment by presenting at several conferences about niche application opportunities in Unmanned Aerial Vehicles (UAV), Autonomous Underwater Vehicles (AUV), portable power and others.« less

Parameter estimation of Monod model by the Least-Squares method for microalgae Botryococcus Braunii sp

NASA Astrophysics Data System (ADS)

See, J. J.; Jamaian, S. S.; Salleh, R. M.; Nor, M. E.; Aman, F.

2018-04-01

This research aims to estimate the parameters of Monod model of microalgae Botryococcus Braunii sp growth by the Least-Squares method. Monod equation is a non-linear equation which can be transformed into a linear equation form and it is solved by implementing the Least-Squares linear regression method. Meanwhile, Gauss-Newton method is an alternative method to solve the non-linear Least-Squares problem with the aim to obtain the parameters value of Monod model by minimizing the sum of square error ( SSE). As the result, the parameters of the Monod model for microalgae Botryococcus Braunii sp can be estimated by the Least-Squares method. However, the estimated parameters value obtained by the non-linear Least-Squares method are more accurate compared to the linear Least-Squares method since the SSE of the non-linear Least-Squares method is less than the linear Least-Squares method.

ADA and C++ Business Case Analysis

DTIC Science & Technology

1991-07-01

executable mini-specs, to support import of existing code. Automated database population/change propagation. 9. Documentation generation: via FrameMaker ...Backplane. ii. 4GLS H-20 I I IDE/Software through Pictures (StP) 12 June 1991 iii. Interleaf and FrameMaker publishing. 13. Output formats: PostScript... FrameMaker , WordPerfect. 12. User interface: Menu and mouse, windowing, color, on-line help, undo. Database browser via forms/tables component later

Glycaemic Index and Load Values Tested in Normoglycemic Adults for Five Staple Foodstuffs: Pounded Yam, Pounded Cassava-Plantain, Placali, Attieke and Maize Meal Stiff Porridge

PubMed Central

Kouamé, Adam C.; Kouassi, Kouakou N.; N’dri, Yao D.; Amani, N’guessan G.

2015-01-01

There is currently an increased global interest in the published glycaemic index (GI) and glycaemic load (GL) values of foods. However, data on the GI and GL values of different varieties of foods within Côte d’Ivoire are very limited. The study therefore aimed at finding the GI and GL of the main food staples in Côte d’Ivoire. Following the International Standard Organisation’s protocol (ISO/FDI 26642:2010), a selection of five staple foodstuffs were tested for their GI and GL. Fasted healthy subjects were given 50 g of available carbohydrate servings of a glucose reference, which was tested twice, and test foods which were tested once, on separate occasions. Excepted attieke (GI 63), the majority of foods tested have a high GI (GI > 70). Attieke (agbodjama) had a high GL (GL 29) while placali (GL 17) and maize meal stiff porridge (GL 16) had medium GLs. The GLs of pounded cassava-plantain and pounded yam are 26 and 22. Consumption of attieke could minimize postprandial blood glucose spikes, in spite of high GL and potentially have benefit in the management and prevention of some chronic diseases. PMID:25690417

Using Stars to Align a Steered Laser System for Cosmic Ray Simulation

NASA Astrophysics Data System (ADS)

Krantz, Harry; Wiencke, Lawrence

2016-03-01

Ultra high energy cosmic rays (UHECRs) are the highest energy cosmic particles with kinetic energy above 1018eV . UHECRs are detected from the air shower of secondary particles and UV florescence that results from interaction with the atmosphere. A high power UV laser beam can be used to simulate the optical signature of a UHCER air shower. The Global Light System (GLS) is a planned network of ground-based light sources including lasers to support the planned space-based Extreme Universe Space Observatory (EUSO). A portable prototype GLS laser station has been constructed at the Colorado School of Mines. Currently the laser system uses reference targets on the ground but stars can be used to better align the beam by providing a complete hemisphere of targets. In this work, a CCD camera is used to capture images of known stars through the steering head optics. The images are analyzed to find the steering head coordinates of the target star. The true coordinates of the star are calculated from the location and time of observation. A universal adjustment for the steering head is determined from the differences between the two pairs of coordinates across multiple stars. This laser system prototype will also be used for preflight tests of the ESUO Super Pressure Balloon mission.

Improved polysaccharide production in a submerged culture of Ganoderma lucidum by the heterologous expression of Vitreoscilla hemoglobin gene.

PubMed

Li, Huan-Jun; Zhang, De-Huai; Yue, Tong-Hui; Jiang, Lu-Xi; Yu, Xuya; Zhao, Peng; Li, Tao; Xu, Jun-Wei

2016-01-10

Expression of Vitreoscilla hemoglobin (VHb) gene was used to improve polysaccharide production in Ganoderma lucidum. The VHb gene, vgb, under the control of the constitutive glyceraldehyde-3-phosphate dehydrogenase gene promoter was introduced into G. lucidum. The activity of expressed VHb was confirmed by the observation of VHb specific CO-difference spectrum with a maximal absorption at 419 nm for the transformant. The effects of VHb expression on intracellular polysaccharide (IPS) content, extracellular polysaccharide (EPS) production and transcription levels of three genes encoding the enzymes involved in polysaccharide biosynthesis, including phosphoglucomutase (PGM), uridine diphosphate glucose pyrophosphorylase (UGP), and β-1,3-glucan synthase (GLS), were investigated. The maximum IPS content and EPS production in the vgb-bearing G. lucidum were 26.4 mg/100mg dry weight and 0.83 g/L, respectively, which were higher by 30.5% and 88.2% than those of the wild-type strain. The transcription levels of PGM, UGP and GLS were up-regulated by 1.51-, 1.55- and 3.83-fold, respectively, in the vgb-bearing G. lucidum. This work highlights the potential of VHb to enhance G. lucidum polysaccharide production by large scale fermentation. Copyright © 2015 Elsevier B.V. All rights reserved.

Secular change of sexually dimorphic cranial variables in Euro-Americans and Germans.

PubMed

Manthey, Laura; Jantz, Richard L; Bohnert, Michael; Jellinghaus, Katharina

2017-07-01

Crania are a reliable source for sex estimation in Euro-Americans, Europeans, and most other populations. Besides morphological assessments, the application of Fordisc® has become a useful tool within the last two decades, creating discriminant functions from morphometric data. Unfortunately, until now, white populations are mostly represented by measurements of American individuals. Therefore, classification rates are lower for European skulls than for Euro-Americans. The aim of this study was to show differences in sexual dimorphism between German and Euro-American crania. Furthermore, their secular change from the nineteenth to the twentieth century has been investigated. Analyses have been performed on glabella subtense (GLS), mastoid height (MDH), and bizygomatic breadth (ZYB). Fordisc® 3.1 was used to study sexual dimorphism and secular change, whereas SAS® was used to perform a two-level ANOVA to test for variation in sex dimorphism. Euro-Americans show greater dimorphism than Germans in all three measurements tested. This larger difference is even increasing from the late nineteenth through the late twentieth century in terms of GLS and MDH, while it stays almost the same in the present Europeans. These results explain the unsatisfying classification rates of German and other European crania on Fordisc®. Data collection for European Fordisc® samples is in progress and should improve the current situation.

Functional characteristics of left ventricular synchronization via right ventricular outflow-tract pacing detected by two-dimensional strain echocardiography.

PubMed

Hirayama, Yasutaka; Kawamura, Yuichiro; Sato, Nobuyuki; Saito, Tatsuya; Tanaka, Hideichi; Saijo, Yasuaki; Kikuchi, Kenjiro; Ohori, Katsumi; Hasebe, Naoyuki

2017-02-01

Recently, due to the detrimental effects on the ventricular function associated with right ventricular apical (RVA) pacing, right ventricular septal (RVS) pacing has become the preferred pacing method. However, the term RVS pacing refers to both right ventricular outflow-tract (RVOT) and mid-septal (RVMS) pacing, leading to a misinterpretation of the results of clinical studies. The purpose of this study, therefore, was to elucidate the functional differences of RVA, RVOT, and RVMS pacing in patients with atrioventricular block. We compared the QRS duration, global longitudinal strain (GLS), and left ventricular (LV) synchronization parameters at the three pacing sites in 47 patients. The peak systolic strain (PSS) time delay between the earliest and latest segments among the 18 LV segments and standard deviation (SD) of the time to the PSS were also calculated for the 18 LV segments at each pacing site using two-dimensional (2D) strain echocardiography. RVMS pacing was associated with a significantly shorter QRS duration compared with RVA and RVOT pacing (154.4±21.4 vs 186.5±19.9 and 171.1±21.5 ms, P <0.001). In contrast, RVOT pacing revealed a greater GLS (-14.69±4.92 vs -13.12±4.76 and -13.51±4.81%, P <0.001), shorter PSS time delay between the earliest and latest segments (236.0±87.9 vs 271.3±102.9 and 281.9±126.6%, P =0.007), and shorter SD of the time to the PSS (70.8±23.8 vs 82.7±30.8 and 81.5±33.7 ms, P =0.002) compared with RVA and RVMS pacing. These results suggest that the functional characteristics of RVOT pacing may be a more optimal pacing site than RVMS, regardless of the pacing QRS duration, in patients with atrioventricular conduction disorders.

suPAR level is associated with myocardial impairment assessed with advanced echocardiography in patients with type 1 diabetes with normal ejection fraction and without known heart disease or end-stage renal disease.

PubMed

Theilade, Simone; Rossing, Peter; Eugen-Olsen, Jesper; Jensen, Jan S; Jensen, Magnus T

2016-06-01

Heart disease is a common fatal diabetes-related complication. Early detection of patients at particular risk of heart disease is of prime importance. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker for development of cardiovascular disease. We investigate if suPAR is associated with early myocardial impairment assessed with advanced echocardiographic methods. In an observational study on 318 patients with type 1 diabetes without known heart disease and with normal left ventricular ejection fraction (LVEF) (biplane LVEF >45%), we performed conventional, tissue Doppler and speckle tracking echocardiography, and measured plasma suPAR levels. Associations between myocardial function and suPAR levels were studied in adjusted models including significant covariates. Patients were 55±12 years (mean±s.d.) and 160 (50%) males. Median (interquartile range) suPAR was 3.4 (1.7) ng/mL and LVEF was 58±5%. suPAR levels were not associated with LVEF (P=0.11). In adjusted models, higher suPAR levels were independently associated with both impaired systolic function assessed with global longitudinal strain (GLS) and tissue velocity s', and with impaired diastolic measures a' and e'/a' (all P=0.034). In multivariable analysis including cardiovascular risk factors and both systolic and diastolic measures (GLS and e'/a'), both remained independently associated with suPAR levels (P=0.012). In patients with type 1 diabetes with normal LVEF and without known heart disease, suPAR is associated with early systolic and diastolic myocardial impairment. Our study implies that both suPAR and advanced echocardiography are useful diagnostic tools for identifying patients with diabetes at risk of future clinical heart disease, suited for intensified medical therapy. © 2016 European Society of Endocrinology.

Reach-scale stream restoration in agricultural streams of southern Minnesota alters structural and functional responses of macroinvertebrates

USGS Publications Warehouse

Dolph, Christine L.; Eggert, Susan L.; Magner, Joe; Ferrington, Leonard C.; Vondracek, Bruce C.

2015-01-01

Recent studies suggest that stream restoration at the reach scale may not increase stream biodiversity, raising concerns about the utility of this conservation practice. We examined whether reach-scale restoration in disturbed agricultural streams was associated with changes in macroinvertebrate community structure (total macroinvertebrate taxon richness, total macroinvertebrate density, Ephemeroptera, Plecoptera, Trichoptera [EPT] taxon richness, % abundance of EPT taxa) or secondary production (macroinvertebrate biomass over time). We collected macroinvertebrate samples over the course of 1 y from restored and unrestored reaches of 3 streams in southern Minnesota and used generalized least-square (GLS) models to assess whether measures of community structure were related to reach type, stream site, or sampling month. After accounting for effects of stream site and time, we found no significant difference in total taxon richness or % abundance of EPT taxa between restored and unrestored reaches. However, the number of EPT taxa and macroinvertebrate density were significantly higher in restored than in unrestored reaches. We compared secondary production estimates among study reaches based on 95th-percentile confidence intervals generated via bootstrapping. In each study stream, secondary production was significantly (2–3×) higher in the restored than in the unrestored reach. Higher productivity in the restored reaches was largely a result of the disproportionate success of a few dominant, tolerant taxa. Our findings suggest that reach-scale restoration may have ecological effects that are not detected by measures of total taxon richness alone.

77 FR 41668 - Standard Instrument Approach Procedures, and Takeoff Minimums and Obstacle Departure Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

... Liberty Intl, GLS RWY 4L, Orig-C Newark, NJ, Newark Liberty Intl, ILS OR LOC RWY 4L, ILS RWY 4L (SA CAT I... by reference in this amendment under 5 U.S.C. 552(a), 1 CFR part 51, and 14 CFR 97.20. The applicable... 97 continues to read as follows: Authority: 49 U.S.C. 106(g), 40103, 40106, 40113, 40114, 40120...

Availability of Ada and C++ Compilers, Tools, Education and Training

DTIC Science & Technology

1991-07-01

executable mini-specs, to support import of existing code. Automated database population/change propagation. 9. Documentation generation: via FrameMaker . 10...formats. 12. Links to other tools: i. Atherton’s Software Backplane. ii. 4GLS iii. Interleaf and FrameMaker publishing. 13. Output formats: PostScript...by end 󈨟. 11. Output formats: ASCII, PostScript, Interleaf, HPGL, Troff, nroff, FrameMaker , WordPerfect. 12. User interface: Menu and mouse

Fitness in Young Adulthood and Long-Term Cardiac Structure and Function: The CARDIA Study.

PubMed

Pandey, Ambarish; Allen, Norrina B; Ayers, Colby; Reis, Jared P; Moreira, Henrique T; Sidney, Stephen; Rana, Jamal S; Jacobs, David R; Chow, Lisa S; de Lemos, James A; Carnethon, Mercedes; Berry, Jarett D

2017-05-01

This study sought to evaluate the association between early-life cardiorespiratory fitness (CRF) and measures of left ventricular (LV) structure and function in midlife. Low CRF in midlife is associated with a higher risk of heart failure. However, the unique contributions of early-life CRF toward measures of LV structure and function in middle age are not known. CARDIA (Coronary Artery Risk Development in Young Adults) study participants with a baseline maximal treadmill test and an echocardiogram at year 25 were included. Associations among baseline CRF, CRF change, and echocardiographic LV parameters (global longitudinal strain [GLS] and global circumferential strain, E/e') were assessed using multivariable linear regression. The study included 3,433 participants. After adjustment for baseline demographic and clinical characteristics, lower baseline CRF was significantly associated with higher LV strain (standardized parameter estimate [Std β] = -0.06; p = 0.03 for GLS) and ratio of early transmitral flow velocity to early peak diastolic mitral annular velocity (E/e') (Std β = -0.10; p = 0.0001 for lateral E/e'), findings suggesting impaired contractility and elevated diastolic filling pressure in midlife. After additional adjustment for cumulative cardiovascular risk factor burden observed over the follow-up period, the association of CRF with LV strain attenuated substantially (p = 0.36), whereas the association with diastolic filling pressure remained significant (Std β = -0.05; p = 0.02 for lateral E/e'). In a subgroup of participants with repeat CRF tests at year 20, greater decline in CRF was significantly associated with increased abnormalities in GLS (Std β = -0.05; p = 0.02) and higher diastolic filling pressure (Std β = -0.06; p = 0.006 for lateral E/e') in middle age. CRF in young adulthood and CRF change were associated with measures of LV systolic function and diastolic filling pressure in middle age. Low CRF-associated abnormalities in systolic function were related to the associated higher cardiovascular risk factor burden. In contrast, the inverse association between CRF and LV diastolic filling pressure was independent of cardiovascular risk factor burden. Copyright © 2017. Published by Elsevier Inc.

AgBufferBuilder: A geographic information system (GIS) tool for precision design and performance assessment of filter strips

Treesearch

M. G. Dosskey; S. Neelakantan; T. G. Mueller; T. Kellerman; M. J. Helmers; E. Rienzi

2015-01-01

Spatially nonuniform runoif reduces the water qua1iry perfortnance of constant- width filter strips. A geographic inlormation system (Gls)-based tool was developed and tested that ernploys terrain analysis to account lor spatially nonuniform runoffand produce more ellbctive filter strip designs.The computer program,AgBufTerBuilder, runs with ATcGIS versions 10.0 and 10...

A quality assessment tool for markup-based clinical guidelines.

PubMed

Shalom, Erez; Shahar, Yuval; Taieb-Maimon, Meirav; Lunenfeld, Eitan

2008-11-06

We introduce a tool for quality assessment of procedural and declarative knowledge. We developed this tool for evaluating the specification of mark-up-based clinical GLs. Using this graphical tool, the expert physician and knowledge engineer collaborate to perform scoring, using pre-defined scoring scale, each of the knowledge roles of the mark-ups, comparing it to a gold standard. The tool enables scoring the mark-ups simultaneously at different sites by different users at different locations.

Glutaminolysis is a metabolic dependency in FLT3ITD acute myeloid leukemia unmasked by FLT3 tyrosine kinase inhibition.

PubMed

Gallipoli, Paolo; Giotopoulos, George; Tzelepis, Konstantinos; Costa, Ana S H; Vohra, Shabana; Medina-Perez, Paula; Basheer, Faisal; Marando, Ludovica; Di Lisio, Lorena; Dias, Joao M L; Yun, Haiyang; Sasca, Daniel; Horton, Sarah J; Vassiliou, George; Frezza, Christian; Huntly, Brian J P

2018-04-12

FLT3 internal tandem duplication (FLT3 ITD ) mutations are common in acute myeloid leukemia (AML) associated with poor patient prognosis. Although new-generation FLT3 tyrosine kinase inhibitors (TKI) have shown promising results, the outcome of FLT3 ITD AML patients remains poor and demands the identification of novel, specific, and validated therapeutic targets for this highly aggressive AML subtype. Utilizing an unbiased genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 screen, we identify GLS, the first enzyme in glutamine metabolism, as synthetically lethal with FLT3-TKI treatment. Using complementary metabolomic and gene-expression analysis, we demonstrate that glutamine metabolism, through its ability to support both mitochondrial function and cellular redox metabolism, becomes a metabolic dependency of FLT3 ITD AML, specifically unmasked by FLT3-TKI treatment. We extend these findings to AML subtypes driven by other tyrosine kinase (TK) activating mutations and validate the role of GLS as a clinically actionable therapeutic target in both primary AML and in vivo models. Our work highlights the role of metabolic adaptations as a resistance mechanism to several TKI and suggests glutaminolysis as a therapeutically targetable vulnerability when combined with specific TKI in FLT3 ITD and other TK activating mutation-driven leukemias. © 2018 by The American Society of Hematology.

Quantitative analyses of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in fields with different soil types.

PubMed

Morimoto, Sho; Hayatsu, Masahito; Takada Hoshino, Yuko; Nagaoka, Kazunari; Yamazaki, Masatsugu; Karasawa, Toshihiko; Takenaka, Makoto; Akiyama, Hiroko

2011-01-01

Soil type is one of the key factors affecting soil microbial communities. With regard to ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), however, it has not been determined how soil type affects their community size and soil nitrification activity. Here we quantitatively analyzed the ammonia monooxygenase genes (amoA) of these ammonia oxidizers in fields with three different soil types (Low-humic Andosol [LHA], Gray Lowland Soil [GLS], and Yellow Soil [YS]) under common cropping conditions, and assessed the relationships between soil nitrification activity and the abundance of each amoA. Nitrification activity of LHA was highest, followed by that of GLS and YS; this order was consistent with that for the abundance of AOB amoA. Abundance of AOB amoA showed temporal variation, which was similar to that observed in nitrification activity, and a strong relationship (adjusted R(2)=0.742) was observed between the abundance of AOB amoA and nitrification activity. Abundance of AOA amoA also exhibited a significant relationship (adjusted R(2)=0.228) with nitrification activity, although this relationship was much weaker. Our results indicate that soil type affects the community size of AOA and AOB and the resulting nitrification activity, and that AOB are major contributors to nitrification in soils, while AOA are partially responsible.

Surgical antibiotic prophylaxis in children: a mixed method study on healthcare professionals attitudes.

PubMed

Giusti, Angela; Spila Alegiani, Stefania; Ciofi Degli Atti, Marta Luisa; Colaceci, Sofia; Raschetti, Roberto; Arace, Pasquale; Spiazzi, Raffaele; Raponi, Massimiliano

2016-12-05

Qualitative and quantitative research investigating determinants of adherence to clinical guidelines (GLs) on surgical antibiotic prophylaxis (SAP) are scarce. We conducted a mixed-method study aimed at investigating barriers and at describing attitudes of healthcare professionals (HCPs) regarding SAP in three Italian children's hospitals. The study comprised two sequential phases: 1) collection of qualitative data through focus groups; 2) conduction of a survey on HCPs attitudes towards SAP. Focus groups were carried out in each hospital with a theoretical convenience sample of 10-15 HCPs. Categorical analysis was conducted. Emerging categories and additional topics derived by literature search were used to develop the survey questionnaire, which included 13 questions expressed through a 4-point Likert scale. Members of surgical teams were invited by e-mail to fill in the questionnaire. We summed up the points assigned to each 4-point Likert scale response and calculated a cumulative score expressing overall concordance to expected HCPs attitudes on SAP. We conducted univariate and multivariate analysis to evaluate the relationship among characteristics of respondents and concordance with expected attitudes. The main categories identified in the qualitative phase included determinants of general adherence to GLs (e.g., relevance of clinical judgment), individual determinants (e.g., poor knowledge on hospital data) and organizational/structural determinants (e.g., patient flows). A total of 357 HCPs participated in the survey (response rate: 82.1%). Among respondents, 75% reported that SAP should be performed with first or second-generation cephalosporins, 44% that 2-3 days of antibiotic administration are useful as a precaution after surgery, 32% that SAP is needed for all surgical procedures. At multivariate analysis, professional category (physicians vs nurses; OR: 3.31; 95%CI: 1.88-5.82), and hospital (hospital 1 and 2 vs hospital 3; ORs: 2.79, 95%CI: 1.22-6.36; 2.40, 95%CI: 1.30-4.43, respectively) were significantly and independently associated with higher concordance with expected attitudes on SAP. Results from this study were useful to identify obstacles to appropriate SAP use in children. In our setting, findings support that a quality-improvement intervention should take into account local contexts, with development of hospital policies, education on SAP recommendations, and dissemination of data on adherence to recommendations.

Conventional and digital radiographic assessment of tooth enamel de-/remineralization processes: an experimental study.

PubMed

Leite-Ribeiro, Patrícia; de Oliveira, Thais Feitosa Leitão; Mathias, Paula; Campo, Elisângela de Jesus; Sarmento, Viviane Almeida

2014-01-01

This study aimed to compare digital techniques for evaluating dental enamel de-/remineralization. Sixty extracted molars were subjected to a process of de- and remineralization. Radiographs were taken before and after each stage. These radiographs were evaluated by the conventional method and were then scanned and analyzed either with or without the use of image enhancement. Moreover, the gray levels (GLs) of the affected areas were measured. All methods exhibited low sensitivity and identical levels of specificity (99.4%). Analysis of the grayscale levels found statistically significant differences between the initial radiographs (P < 0.05). The mean GL of the carious group was significantly lower than that of the remineralized group. The GL did not differ significantly between the initial and final radiographs of the remineralized group, although the mean of the first group was lower than that of the second, which demonstrated that the remineralization process restored the normal density of the dental enamel. Measurement of the mean GL was sufficiently sensitive to detect small alterations in the surface of the enamel.

Optimal least-squares finite element method for elliptic problems

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Povinelli, Louis A.

1991-01-01

An optimal least squares finite element method is proposed for two dimensional and three dimensional elliptic problems and its advantages are discussed over the mixed Galerkin method and the usual least squares finite element method. In the usual least squares finite element method, the second order equation (-Delta x (Delta u) + u = f) is recast as a first order system (-Delta x p + u = f, Delta u - p = 0). The error analysis and numerical experiment show that, in this usual least squares finite element method, the rate of convergence for flux p is one order lower than optimal. In order to get an optimal least squares method, the irrotationality Delta x p = 0 should be included in the first order system.

Evaluation of mechanical properties of some glycine complexes

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

Nagaraju, D.; Raja Shekar, P. V., E-mail: pvrsleo@gmail.com; Chandra, Ch. Sateesh

2014-04-24

The variation of Vickers hardness with load for (101) glycine zinc chloride (GZC), (001) glycine lithium sulphate (GLS), (001) triglycine sulphate (TGS) and (010) glycine phosphite (GPI) crystals was studied. From the cracks initiated along the corners of the indentation impression, crack lengths were measured and the fracture toughness value and brittle index number were determined. The hardness related parameters viz. yield strength and Young’s modulus were also estimated. The anisotropic nature of the crystals was studied using Knoop indentation technique.

The spatial distribution of underage tobacco sales in Los Angeles.

PubMed

Lipton, Robert; Banerjee, Aniruddha; Levy, David; Manzanilla, Nora; Cochrane, Michelle

2008-01-01

Underage tobacco sales is considered a serious public health problem in Los Angeles. Anecdotally, rates have been thought to be quite high. In this paper, using spatial statistical techniques, we describe underage tobacco sales, identifying areas with high levels of sales and hot spots controlling for sociodemographic measures. Six hundred eighty-nine tobacco outlets were investigated throughout the city of Los Angeles in 2001. We consider the factors that explain vendor location of illegal sales of tobacco to underage youth and focus on those areas with especially high rates of illegal sales when controlling for other independent measures. Using data from the census, the LA City Attorney's Office, and public records on school locations in Los Angeles, we employ general least-squares (GLS) estimators in order to avoid biased estimates. vendor location of underage tobacco compliance checks, violators, and nonviolators. Underage tobacco sales in Los Angeles were very high (33.5%) for the entire city in 2001. In many zip codes this rate is considerably higher (60%-100%). When conducting spatial modeling, lower income and ethnicity were strongly associated with increases in underage tobacco sales. Hotspot areas of underage tobacco sales also had much lower mean family income and a much higher percentage of foreign born and greater population density. Spatial techniques were used to better identify areas where vendors sell tobacco to underage youth. Lower income areas were much more likely to both have higher rates of underage tobacco sales and to be a hot spot for such sales. Population density is also significantly associated with underage tobacco sales. The study's limitations are noted.

Creating Magic Squares.

ERIC Educational Resources Information Center

Lyon, Betty Clayton

1990-01-01

One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)

Two-dimensional strain profiles in patients with physiological and pathological hypertrophy and preserved left ventricular systolic function: a comparative analyses.

PubMed

Afonso, Luis; Kondur, Ashok; Simegn, Mengistu; Niraj, Ashutosh; Hari, Pawan; Kaur, Ramanjit; Ramappa, Preeti; Pradhan, Jyotiranjan; Bhandare, Deepti; Williams, Kim A; Zalawadiya, Sandip; Pinheiro, Aurelio; Abraham, Theodore P

2012-01-01

This study was designed to examine the utility of two-dimensional strain (2DS) or speckle tracking imaging to typify functional adaptations of the left ventricle in variant forms of left ventricular hypertrophy (LVH). Cross-sectional study. Urban tertiary care academic medical centres. A total of 129 subjects, 56 with hypertrophic cardiomyopathy (HCM), 34 with hypertensive left ventricular hypertrophy (H-LVH), 27 professional athletes with LVH (AT-LVH) and 12 healthy controls in sinus rhythm with preserved left ventricular systolic function. Conventional echocardiographic and tissue Doppler examinations were performed in all study subjects. Bi-dimensional acquisitions were analysed to map longitudinal systolic strain (automated function imaging, AFI, GE Healthcare, Waukesha, Wisconsin, USA) from apical views. Subjects with HCM had significantly lower regional and average global peak longitudinal systolic strain (GLS-avg) compared with controls and other forms of LVH. Strain dispersion index, a measure of regional contractile heterogeneity, was higher in HCM compared with the rest of the groups. On receiver operator characteristics analysis, GLS-avg had excellent discriminatory ability to distinguish HCM from H-LVH area under curve (AUC) (0.893, p<0.001) or AT-LVH AUC (0.920, p<0.001). Tissue Doppler and LV morphological parameters were better suited to differentiate the athlete heart from HCM. 2DS (AFI) allows rapid characterisation of regional and global systolic function and may have the potential to differentiate HCM from variant forms of LVH.

Influence of high latitude light conditions on sensory quality and contents of health and sensory-related compounds in swede roots (Brassica napus L. ssp. rapifera Metzg.).

PubMed

Mølmann, Jørgen Ab; Hagen, Sidsel Fiskaa; Bengtsson, Gunnar B; Johansen, Tor J

2018-02-01

Vegetable growers in Arctic areas must increasingly rely on market strategies based on regional origin and product quality. Swede roots (rutabaga) were grown in a phytotron to investigate the effect of high latitude light conditions on sensory quality and some health and sensory-related compounds. Experimental treatments included modifications of 24 h natural day length (69° 39' N) by moving plants at daily intervals to dark chambers with either no light, fluorescent growth light and/or low intensity photoperiod extension. Shortening the photosynthetic light period to 12 h produced smaller roots than 15.7 h and 18 h, with highest scores for bitter and sulfur taste, and lowest scores for sweetness, acidic taste and fibrousness. The photoperiod in combination with the photosynthetic light period also had an influence on glucosinolate (GLS) contents, with lowest concentrations in 24 h natural light and highest in 12 h natural light. Concentrations of vitamin C, glucose, fructose and sucrose were not significantly influenced by any of the treatments. High latitude light conditions, with long photosynthetic light periods and 24 h photoperiod, can enhance sweet/less bitter taste and reduce GLS contents in swede roots, compared to growth under short day conditions. This influence of light conditions on eating quality may benefit marketing of regional products from high latitudes. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Maternal vitamin B6 deficient or supplemented diets on expression of genes related to GABAergic, serotonergic, or glutamatergic pathways in hippocampus of rat dams and their offspring.

PubMed

Almeida, Mara Ribeiro; Mabasa, Lawrence; Crane, Courtney; Park, Chung S; Venâncio, Vinícius Paula; Bianchi, Maria Lourdes Pires; Antunes, Lusânia Maria Greggi

2016-07-01

Vitamin B6 plays crucial roles on brain development and its maternal deficiency impacts the gamma-aminobutyric acid (GABA)ergic, serotonergic, glutamatergic, and dopaminergic systems in offspring. However, the molecular mechanisms underlying these neurological changes are not well understood. Thus, we aimed at evaluating which components of those neurotransmitter metabolism and signaling pathways can be modulated by maternal vitamin B6 -deficient or B6 -supplementated diets in the hippocampus of rat dams and their offspring. Female Wistar rats were fed three different diets: control (6 mg vitamin B6 /kg), supplemented (30 mg vitamin B6 /kg) or deficient diet (0 mg vitamin B6 /kg), from 4 weeks before pregnancy through lactation. Newborn pups (10 days old) from rat dams fed vitamin B6 -deficient diet presented hyperhomocysteinemia and had a significant increase in mRNA levels of glutamate decarboxylase 1 (Gad1), fibroblast growth factor 2 (Fgf2), and glutamate-ammonia ligase (Glul), while glutaminase (Gls) and tryptophan hydroxylase 1 (Tph1) mRNAs were downregulated. Vitamin B6 supplementation or deficiency did not change hippocampal global DNA methylation. A maternal vitamin B6 -deficient diet affects the expression of genes related to GABA, glutamate, and serotonin metabolisms in offspring by regulating Gad1, Glul, Gls, and Tph1 mRNA expression. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flood-Frequency Estimates for Streams on Kaua`i, O`ahu, Moloka`i, Maui, and Hawai`i, State of Hawai`i

USGS Publications Warehouse

Oki, Delwyn S.; Rosa, Sarah N.; Yeung, Chiu W.

2010-01-01

This study provides an updated analysis of the magnitude and frequency of peak stream discharges in Hawai`i. Annual peak-discharge data collected by the U.S. Geological Survey during and before water year 2008 (ending September 30, 2008) at stream-gaging stations were analyzed. The existing generalized-skew value for the State of Hawai`i was retained, although three methods were used to evaluate whether an update was needed. Regional regression equations were developed for peak discharges with 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals for unregulated streams (those for which peak discharges are not affected to a large extent by upstream reservoirs, dams, diversions, or other structures) in areas with less than 20 percent combined medium- and high-intensity development on Kaua`i, O`ahu, Moloka`i, Maui, and Hawai`i. The generalized-least-squares (GLS) regression equations relate peak stream discharge to quantified basin characteristics (for example, drainage-basin area and mean annual rainfall) that were determined using geographic information system (GIS) methods. Each of the islands of Kaua`i,O`ahu, Moloka`i, Maui, and Hawai`i was divided into two regions, generally corresponding to a wet region and a dry region. Unique peak-discharge regression equations were developed for each region. The regression equations developed for this study have standard errors of prediction ranging from 16 to 620 percent. Standard errors of prediction are greatest for regression equations developed for leeward Moloka`i and southern Hawai`i. In general, estimated 100-year peak discharges from this study are lower than those from previous studies, which may reflect the longer periods of record used in this study. Each regression equation is valid within the range of values of the explanatory variables used to develop the equation. The regression equations were developed using peak-discharge data from streams that are mainly unregulated, and they should not be used to estimate peak discharges in regulated streams. Use of a regression equation beyond its limits will produce peak-discharge estimates with unknown error and should therefore be avoided. Improved estimates of the magnitude and frequency of peak discharges in Hawai`i will require continued operation of existing stream-gaging stations and operation of additional gaging stations for areas such as Moloka`i and Hawai`i, where limited stream-gaging data are available.

Infrared Spectroscopic Imaging for Prostate Pathology Practice

DTIC Science & Technology

2009-03-01

0.3 9 2 bpa Bupa Liver Disorders 345 0.0 6 2 gls Glass 214 0.0 9 6 h s Heart Stats Log 270 0.0 13 2 ion Ionosphere 351 0.0 34 2 irs Iris 150 0.0 4 3...2008, John Wiley and Sons. (42) Hanley, J.A.; McNeil, B.J. Radiology 1982, 143, 29-36. Histologic models for optical tomography and...spectroscopic generation of contrast can serve as standard for testing and design aid for tomography and spectroscopy of tissues. We discuss here the

Model Validation for a Noninvasive Arterial Stenosis Detection Problem

DTIC Science & Technology

2013-06-09

simplicity in the final model, at the expense of some minor notational confusion at the current stage . Note that (9) implies that ur(r, t) = − A rmax...which was an improvement computationally since it led to purely differential equations in the model rather than inclusion of an integro-differential...values (c.f. (15)), this gives us θ0gls = (3.6532, 0.6990, 4.4472,−1.2218,−3.7696,−2) T . 4.1.2 Residuals We will also include residual plots to assist

A high order compact least-squares reconstructed discontinuous Galerkin method for the steady-state compressible flows on hybrid grids

NASA Astrophysics Data System (ADS)

Cheng, Jian; Zhang, Fan; Liu, Tiegang

2018-06-01

In this paper, a class of new high order reconstructed DG (rDG) methods based on the compact least-squares (CLS) reconstruction [23,24] is developed for simulating the two dimensional steady-state compressible flows on hybrid grids. The proposed method combines the advantages of the DG discretization with the flexibility of the compact least-squares reconstruction, which exhibits its superior potential in enhancing the level of accuracy and reducing the computational cost compared to the underlying DG methods with respect to the same number of degrees of freedom. To be specific, a third-order compact least-squares rDG(p1p2) method and a fourth-order compact least-squares rDG(p2p3) method are developed and investigated in this work. In this compact least-squares rDG method, the low order degrees of freedom are evolved through the underlying DG(p1) method and DG(p2) method, respectively, while the high order degrees of freedom are reconstructed through the compact least-squares reconstruction, in which the constitutive relations are built by requiring the reconstructed polynomial and its spatial derivatives on the target cell to conserve the cell averages and the corresponding spatial derivatives on the face-neighboring cells. The large sparse linear system resulted by the compact least-squares reconstruction can be solved relatively efficient when it is coupled with the temporal discretization in the steady-state simulations. A number of test cases are presented to assess the performance of the high order compact least-squares rDG methods, which demonstrates their potential to be an alternative approach for the high order numerical simulations of steady-state compressible flows.

[Research on optimization of mathematical model of flow injection-hydride generation-atomic fluorescence spectrometry].

PubMed

Cui, Jian; Zhao, Xue-Hong; Wang, Yan; Xiao, Ya-Bing; Jiang, Xue-Hui; Dai, Li

2014-01-01

Flow injection-hydride generation-atomic fluorescence spectrometry was a widely used method in the industries of health, environmental, geological and metallurgical fields for the merit of high sensitivity, wide measurement range and fast analytical speed. However, optimization of this method was too difficult as there exist so many parameters affecting the sensitivity and broadening. Generally, the optimal conditions were sought through several experiments. The present paper proposed a mathematical model between the parameters and sensitivity/broadening coefficients using the law of conservation of mass according to the characteristics of hydride chemical reaction and the composition of the system, which was proved to be accurate as comparing the theoretical simulation and experimental results through the test of arsanilic acid standard solution. Finally, this paper has put a relation map between the parameters and sensitivity/broadening coefficients, and summarized that GLS volume, carrier solution flow rate and sample loop volume were the most factors affecting sensitivity and broadening coefficients. Optimizing these three factors with this relation map, the relative sensitivity was advanced by 2.9 times and relative broadening was reduced by 0.76 times. This model can provide a theoretical guidance for the optimization of the experimental conditions.

Least Squares Procedures.

ERIC Educational Resources Information Center

Hester, Yvette

Least squares methods are sophisticated mathematical curve fitting procedures used in all classical parametric methods. The linear least squares approximation is most often associated with finding the "line of best fit" or the regression line. Since all statistical analyses are correlational and all classical parametric methods are least…

The importance of speckle tracking echocardiography in the early detection of left ventricular dysfunction in patients with polycystic ovary syndrome.

PubMed

Demirelli, Selami; Degirmenci, Husnu; Ermis, Emrah; Inci, Sinan; Nar, Gokay; Ayhan, Mehmet Emin; Fırtına, Serdar; Hamur, Hikmet; Durmaz, Senay Arikan

2015-10-19

Polycystic ovary syndrome (PCOS) is characterized by hormonal and metabolic abnormalities and is thought to increase a risk for cardiovascular diseases. In this study we use speckle tracking echocardiography (STE) to evaluate left ventricular (LV) dysfunction in the early period of the disease. We enrolled 31 patients with PCOS and 32 healthy volunteers as a control group. The participants' ages ranged between 18 and 40 years. PCOS was diagnosed according to the Rotterdam criteria. LV strain (LS) and strain rate (SR) were evaluated using apical two-chamber (2C), three-chamber (3C), and four-chamber (4C) imaging. Global LS and SR were calculated as average of three apical views. The waist-to-hip ratio, homeostasis model assessment-insulin resistance (HOMA-IR), and fasting insulin and triglyceride levels were higher in the PCOS group than in the controls (p=0.001, p=0.001, p=0.001, and p=0.005, respectively). In the PCOS group, the mitral A wave, deceleration time (DT), and isovolumetric relaxation time (IVRT) were significantly higher than in the controls (all p<0.05). The LV global longitudinal strain (GLS) and global longitudinal SR systolic (GLSRS) were significantly lower in the PCOS patient group (both p= 0.001). There were strong negative correlations between GLS and both fasting insulin (r=-0.64) and DT (r=-0.62) (both p<0.05). The study demonstrated that PCOS patients had decreased LV function using STE. Therefore, STE imaging appears to be useful for the early detection of subclinical LV dysfunction in patients with PCOS.

Gestational length in Carthusian broodmares: effects of breeding season, foal gender, age of mare, year of parturition, parity and sire.

PubMed

Satué, K; Felipe, M; Mota, J; Muñoz, A

2011-01-01

The length of gestation in Carthusian broodmares was calculated on the basis of 339 spontaneous full-term deliveries taking place in the 8-year period 1998-2005 from 158 broodmares and 29 stallions in a major farm of Spanish horses of Carthusian strain in southern Spain. Ultrasonography was used to determine follicular dehiscence, 1st day of pregnancy and to confirm conception in mares. Mean GL was 332.4 +/- 12.1 days, and a normal interval of 297-358 days was established for this breed. GL records were grouped on the basis of foal sex (colts or fillies), mating month (between November and January; February and April; May and July), age of the mare (4 to 7 years; 8 to 12 years; 13 to 17 years), breeding year, stallion and parity (primiparous vs. multiparous). GLs were 12.9 days shorter in mares mated between May and July than those mated between November and January and 15.3 days in mares mated between February and April (p < 0.001). Mares aged between 8-12 years had 5.3 days shorter GLs than those aged between 13-17 years (p < 0.05). Pregnancy was significantly 5.7 days longer when the mare gave birth to colts than fillies (p < 0.05). GL was 14.5 days longer in primiparous than in multiparous mares ( p < 0.001). No statistical differences in GL were found between the studied years. This study shows the influence of certain stallion on GL.

A Note on Magic Squares

ERIC Educational Resources Information Center

Williams, Horace E.

1974-01-01

A method for generating 3x3 magic squares is developed. A series of questions relating to these magic squares is posed. An invesitgation using matrix methods is suggested with some questions for consideration. (LS)

An analysis of security price risk and return among publicly traded pharmacy corporations.

PubMed

Gilligan, Adrienne M; Skrepnek, Grant H

2013-01-01

Community pharmacies have been subject to intense and increasing competition in the past several decades. To determine the security price risk and rate of return of publicly traded pharmacy corporations present on the major U.S. stock exchanges from 1930 to 2009. The Center of Research in Security Prices (CRSP) database was used to examine monthly security-level stock market prices in this observational retrospective study. The primary outcome of interest was the equity risk premium, with analyses focusing upon financial metrics associated with risk and return based upon modern portfolio theory (MPT) including: abnormal returns (i.e., alpha), volatility (i.e., beta), and percentage of returns explained (i.e., adjusted R(2)). Three equilibrium models were estimated using random-effects generalized least squares (GLS): 1) the Capital Asset Pricing Model (CAPM); 2) Fama-French Three-Factor Model; and 3) Carhart Four-Factor Model. Seventy-five companies were examined from 1930 to 2009, with overall adjusted R(2) values ranging from 0.13 with the CAPM to 0.16 with the Four-Factor model. Alpha was not significant within any of the equilibrium models across the entire 80-year time period, though was found from 1999 to 2009 in the Three- and Four-Factor models to be associated with a large, significant, and negative risk-adjusted abnormal returns of -33.84%. Volatility varied across specific time periods based upon the financial model employed. This investigation of risk and return within publicly listed pharmacy corporations from 1930 to 2009 found that substantial losses were incurred particularly from 1999 to 2009, with risk-adjusted security valuations decreasing by one-third. Copyright © 2013 Elsevier Inc. All rights reserved.

Genetic and environmental causes of variation in gestation length of Jersey crossbred cattle.

PubMed

Kumar, Anshuman; Mandal, Ajoy; Gupta, A K; Ratwan, Poonam

2016-04-01

The objective of this study was to investigate the effect of genetic and non-genetic factors and estimate the genetic parameter for gestation length (GL) of Jersey crossbred cattle. The data included the 986 parturition records on Jersey crossbred cattle maintained at the Eastern Regional Station of ICAR-National Dairy Research Institute, Kalyani, West Bengal, India during 36 years (1978-2013). The data were analyzed applying mixed model least square technique considering the fixed effects of genetic group, season of calving, period of calving, parity of animal, birth weight, and sex of calf born from animal. The effect of sire was included as a random effect in the model. The genetic group of animal, season of calving, parity of animal, and birth weight of calf born were found to be a significant source of variation in the GL, whereas the period of calving and sex of calf did not affect this trait. Cows with <50% and >62.5% Jersey inheritance had the shortest and longest GLs, respectively. Cows calved in summer and rainy season had shorter GL than those calved in the winter season. Older cows in 4(th) parity carried calves for longer days than the cows in 1(st) parity. The increase in calf birth weight significantly (p<0.01) contributed to a linear increase in GL value in this study. The heritability estimate of GL was 0.24±0.08. It can be concluded that selection for lower GL without distressing future growth of calf can be used to reduce calving difficulty, but a very small standard deviation of GL limits the benefit. Moreover, more accurate prediction of calving date will help in better management and health care of pregnant animals.

Proceedings of the (20th) Annual Military Librarians’ Workshop on Public Relations, United States Naval Academy, Annapolis, Maryland, 20-22 October 1976

DTIC Science & Technology

1976-10-22

tat afec. out livs dont now wathyarvoig They’ doin’t i.now what they are doing simply becausc the have no adequa te basis to judge the effects of thir...publicity toGls. The main ones that I use are radio, te!hvision, newsletters for patrons, staff notes, booklets, posters , and last of all--the library...especially in the libraries. It is the most God awful color. You can cover t 13 it though. You can get loads of posters from all over the place--foreign

Value of three-dimensional speckle tracking echocardiography to assess left ventricular function in hyperuricemia patients.

PubMed

Zhang, Xiaojie; Lu, Qing; Zhang, Zhuojun; Chen, Yongle; Wang, Yanan; Wang, Youngshi; Li, Zheng; Jiang, Lindi

2018-05-22

To assess the value of three-dimensional speckle tracking echocardiography (3D STE) in evaluating the left ventricular (LV) function in hyperuricemia patients. We enrolled 15 healthy controls and 40 hyperuricemia patients and collected and analyzed full-volume 3D STE images of the left ventricle in the apical four-chamber heart view. Laboratory tests and 3D STE parameters, including left ventricular ejection fraction, left ventricular end-diastolic volume, left ventricular end-systolic volume, stroke volume (SV), global longitudinal strain (GLS), and global circumferential strain (GCS), were compared between hyperuricemia patients and healthy controls. Hyperuricemia patients exhibited higher body mass index (24.70 ± 2.9 vs. 21.83 ± 2.4 kg/m 2 , p = 0.001), C-reactive protein (5.82 ± 9.4 vs. 1.12 ± 1.8 g/L, p = 0.012), alanine transaminase (34.26 ± 26.6 vs. 17.60 ± 13.0 U/L, p = 0.011), aspartate transaminase (24.90 ± 11.3 vs. 17.70 ± 4.1 U/L, p = 0.001), blood urea nitrogen (5.11 ± 1.6 vs. 4.18 ± 0.6 mmol/L, p = 0.046), and serum creatinine (90.25 ± 14.6 vs. 77.93 ± 10.8 μmol/L, p = 0.006) levels, as well as a lower estimated glomerular filtration rate (87.87 ± 16.5 vs. 103.64 ± 11.3 mL/min/1.73m 2 , p = 0.002). The 3D STE parameters reflecting LV function, including SV (54.71 ± 9.6 vs. 61.92 ± 14.4 mL, p = 0.024), GLS (- 20.51 ± 4.0 vs. - 23.20 ± 4.0%, p = 0.019), and GCS (- 31.30 ± 5.0 vs. - 35.65 ± 2.5%, p = 0.000), were significantly decreased in hyperuricemia patients. Furthermore, GCS was significantly correlated with the serum uric acid (sUA) level even after adjustment of confounding variables like age, body mass index, and serum creatinine. 3D STE is a novel technique for recognizing the early decline in LV function, with GLS and GCS serving as reliable indicators, in hyperuricemia patients. Moreover, the degree of decline in LV function may be correlated with the sUA level in hyperuricemia patients.

40 CFR Appendix C to Subpart Nnn... - Method for the Determination of Product Density

Code of Federal Regulations, 2011 CFR

2011-07-01

... insulation. The method is applicable to all cured board and blanket products. 2. Equipment One square foot (12 in. by 12 in.) template, or templates that are multiples of one square foot, for use in cutting... procedure for the designated product. 3.2Cut samples using one square foot (or multiples of one square foot...

40 CFR Appendix C to Subpart Nnn... - Method for the Determination of Product Density

Code of Federal Regulations, 2012 CFR

2012-07-01

.... The method is applicable to all cured board and blanket products. 2. Equipment One square foot (12 in. by 12 in.) template, or templates that are multiples of one square foot, for use in cutting... procedure for the designated product. 3.2Cut samples using one square foot (or multiples of one square foot...

40 CFR Appendix C to Subpart Nnn... - Method for the Determination of Product Density

Code of Federal Regulations, 2010 CFR

2010-07-01

.... The method is applicable to all cured board and blanket products. 2. Equipment One square foot (12 in. by 12 in.) template, or templates that are multiples of one square foot, for use in cutting... procedure for the designated product. 3.2Cut samples using one square foot (or multiples of one square foot...

The covariance matrix for the solution vector of an equality-constrained least-squares problem

NASA Technical Reports Server (NTRS)

Lawson, C. L.

1976-01-01

Methods are given for computing the covariance matrix for the solution vector of an equality-constrained least squares problem. The methods are matched to the solution algorithms given in the book, 'Solving Least Squares Problems.'

Adaptive Modal Identification for Flutter Suppression Control

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.; Drew, Michael; Swei, Sean S.

2016-01-01

In this paper, we will develop an adaptive modal identification method for identifying the frequencies and damping of a flutter mode based on model-reference adaptive control (MRAC) and least-squares methods. The least-squares parameter estimation will achieve parameter convergence in the presence of persistent excitation whereas the MRAC parameter estimation does not guarantee parameter convergence. Two adaptive flutter suppression control approaches are developed: one based on MRAC and the other based on the least-squares method. The MRAC flutter suppression control is designed as an integral part of the parameter estimation where the feedback signal is used to estimate the modal information. On the other hand, the separation principle of control and estimation is applied to the least-squares method. The least-squares modal identification is used to perform parameter estimation.

Integrated optics prototype beam combiner for long baseline interferometry in the L and M bands

NASA Astrophysics Data System (ADS)

Tepper, J.; Labadie, L.; Diener, R.; Minardi, S.; Pott, J.-U.; Thomson, R.; Nolte, S.

2017-06-01

Context. Optical long baseline interferometry is a unique way to study astronomical objects at milli-arcsecond resolutions not attainable with current single-dish telescopes. Yet, the significance of its scientfic return strongly depends on a dense coverage of the uv-plane and a highly stable transfer function of the interferometric instrument. In the last few years, integrated optics (IO) beam combiners have facilitated the emergence of 4-telescope interferometers such as PIONIER or GRAVITY, boosting the imaging capabilities of the VLTI. However, the spectral range beyond 2.2 μm is not ideally covered by the conventional silica based IO. Here, we consider new laser-written IO prototypes made of gallium lanthanum sulfide (GLS) glass, a material that permits access to the mid-infrared spectral regime. Aims: Our goal is to conduct a full characterization of our mid-IR IO two-telescope coupler in order to measure the performance levels directly relevant for long-baseline interferometry. We focus in particular on the exploitation of the L and M astronomical bands. Methods: We use a dedicated Michelson-interferometer setup to perform Fourier transform spectroscopy on the coupler and measure its broadband interferometric performance. We also analyze the polarization properties of the coupler, the differential dispersion and phase degradation, as well as the modal behavior and the total throughput. Results: We measure broadband interferometric contrasts of 94.9% and 92.1% for unpolarized light in the L and M bands. Spectrally integrated splitting ratios are close to 50%, but show chromatic dependence over the considered bandwidths. Additionally, the phase variation due to the combiner is measured and does not exceed 0.04 rad and 0.07 rad across the L and M band, respectively. The total throughput of the coupler including Fresnel and injection losses from free-space is 25.4%. Furthermore, differential birefringence is low (<0.2 rad), in line with the high contrasts reported for unpolarized light. Conclusions: The laser-written IO GLS prototype combiners prove to be a reliable technological solution with promising performance for mid-infrared long-baseline interferometry. In the next steps, we will consider more advanced optical functions, as well as a fiber-fed input, and we will revise the optical design parameters in order to further enhance the total throughput and achromatic behavior.

Least squares regression methods for clustered ROC data with discrete covariates.

PubMed

Tang, Liansheng Larry; Zhang, Wei; Li, Qizhai; Ye, Xuan; Chan, Leighton

2016-07-01

The receiver operating characteristic (ROC) curve is a popular tool to evaluate and compare the accuracy of diagnostic tests to distinguish the diseased group from the nondiseased group when test results from tests are continuous or ordinal. A complicated data setting occurs when multiple tests are measured on abnormal and normal locations from the same subject and the measurements are clustered within the subject. Although least squares regression methods can be used for the estimation of ROC curve from correlated data, how to develop the least squares methods to estimate the ROC curve from the clustered data has not been studied. Also, the statistical properties of the least squares methods under the clustering setting are unknown. In this article, we develop the least squares ROC methods to allow the baseline and link functions to differ, and more importantly, to accommodate clustered data with discrete covariates. The methods can generate smooth ROC curves that satisfy the inherent continuous property of the true underlying curve. The least squares methods are shown to be more efficient than the existing nonparametric ROC methods under appropriate model assumptions in simulation studies. We apply the methods to a real example in the detection of glaucomatous deterioration. We also derive the asymptotic properties of the proposed methods. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Domain Decomposition Algorithms for First-Order System Least Squares Methods

NASA Technical Reports Server (NTRS)

Pavarino, Luca F.

1996-01-01

Least squares methods based on first-order systems have been recently proposed and analyzed for second-order elliptic equations and systems. They produce symmetric and positive definite discrete systems by using standard finite element spaces, which are not required to satisfy the inf-sup condition. In this paper, several domain decomposition algorithms for these first-order least squares methods are studied. Some representative overlapping and substructuring algorithms are considered in their additive and multiplicative variants. The theoretical and numerical results obtained show that the classical convergence bounds (on the iteration operator) for standard Galerkin discretizations are also valid for least squares methods.

Least-squares collocation meshless approach for radiative heat transfer in absorbing and scattering media

NASA Astrophysics Data System (ADS)

Liu, L. H.; Tan, J. Y.

2007-02-01

A least-squares collocation meshless method is employed for solving the radiative heat transfer in absorbing, emitting and scattering media. The least-squares collocation meshless method for radiative transfer is based on the discrete ordinates equation. A moving least-squares approximation is applied to construct the trial functions. Except for the collocation points which are used to construct the trial functions, a number of auxiliary points are also adopted to form the total residuals of the problem. The least-squares technique is used to obtain the solution of the problem by minimizing the summation of residuals of all collocation and auxiliary points. Three numerical examples are studied to illustrate the performance of this new solution method. The numerical results are compared with the other benchmark approximate solutions. By comparison, the results show that the least-squares collocation meshless method is efficient, accurate and stable, and can be used for solving the radiative heat transfer in absorbing, emitting and scattering media.

A 3D unstructured grid nearshore hydrodynamic model based on the vortex force formalism

NASA Astrophysics Data System (ADS)

Zheng, Peng; Li, Ming; van der A, Dominic A.; van der Zanden, Joep; Wolf, Judith; Chen, Xueen; Wang, Caixia

2017-08-01

A new three-dimensional nearshore hydrodynamic model system is developed based on the unstructured-grid version of the third generation spectral wave model SWAN (Un-SWAN) coupled with the three-dimensional ocean circulation model FVCOM to enable the full representation of the wave-current interaction in the nearshore region. A new wave-current coupling scheme is developed by adopting the vortex-force (VF) scheme to represent the wave-current interaction. The GLS turbulence model is also modified to better reproduce wave-breaking enhanced turbulence, together with a roller transport model to account for the effect of surface wave roller. This new model system is validated first against a theoretical case of obliquely incident waves on a planar beach, and then applied to three test cases: a laboratory scale experiment of normal waves on a beach with a fixed breaker bar, a field experiment of oblique incident waves on a natural, sandy barred beach (Duck'94 experiment), and a laboratory study of normal-incident waves propagating around a shore-parallel breakwater. Overall, the model predictions agree well with the available measurements in these tests, illustrating the robustness and efficiency of the present model for very different spatial scales and hydrodynamic conditions. Sensitivity tests indicate the importance of roller effects and wave energy dissipation on the mean flow (undertow) profile over the depth. These tests further suggest to adopt a spatially varying value for roller effects across the beach. In addition, the parameter values in the GLS turbulence model should be spatially inhomogeneous, which leads to better prediction of the turbulent kinetic energy and an improved prediction of the undertow velocity profile.

Non-volumetric echocardiographic indices and qualitative assessment of right ventricular systolic function in Ebstein's anomaly: comparison with CMR-derived ejection fraction in 49 patients.

PubMed

Kühn, Andreas; Meierhofer, Christian; Rutz, Tobias; Rondak, Ina-Christine; Röhlig, Christoph; Schreiber, Christian; Fratz, Sohrab; Ewert, Peter; Vogt, Manfred

2016-08-01

Ebstein's anomaly (EA) is often associated with right ventricular (RV) dysfunction. Data on echocardiographic quantification of RV function are, however, rare. The aim of this study was to determine how non-volumetric echocardiographic indices and qualitative assessment of global systolic RV function correlate with cardiovascular magnetic resonance (CMR)-derived RV ejection fraction (EF). We compared six echocardiographic indices and qualitative assessment of RV function with the gold standard CMR. A total of 49 unoperated patients with EA and a mean age of 32 ± 18 years were examined. Tricuspid annular plane systolic excursion, tissue Doppler myocardial velocities (peak S and IVA) and 2D strain and strain rate measures for the RV were compared with CMR-derived EF. Only 2D global longitudinal strain (2D-GLS), out of the six parameters investigated, showed a weak, although statistically significant correlation with CMR-derived RVEF (R = -0.4, P = 0.01). Using a cut-off value of -20.15, 2D-GLS sensitivity (77%) and specificity (46%) in detecting patients with a CMR-derived EF of <50% were comparable with qualitative assessment (sensitivity 77%, specificity 45%). Overall echocardiographic parameters of RV function correlate poorly with CMR-derived EF in patients with EA. Only 2D global longitudinal RV strain correlated weakly with CMR-derived RVEF. However, the sensitivity and specificity for detecting RV dysfunction using 2D strain imaging were comparable with qualitative RV functional assessment. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

The origin and evolution of human glutaminases and their atypical C-terminal ankyrin repeats

DOE PAGES

Pasquali, Camila Cristina; Islam, Zeyaul; Adamoski, Douglas; ...

2017-05-19

On the basis of tissue-specific enzyme activity and inhibition by catalytic products, Hans Krebs first demonstrated the existence of multiple glutaminases in mammals. Currently, two human genes are known to encode at least four glutaminase isoforms. But, the phylogeny of these medically relevant enzymes remains unclear, prompting us to investigate their origin and evolution. Using prokaryotic and eukaryotic glutaminase sequences, we built a phylogenetic tree whose topology suggested that the multidomain architecture was inherited from bacterial ancestors, probably simultaneously with the hosting of the proto-mitochondrion endosymbiont. We propose an evolutionary model wherein the appearance of the most active enzyme isoform,more » glutaminase C (GAC), which is expressed in many cancers, was a late retrotransposition event that occurred in fishes from the Chondrichthyes class. The ankyrin (ANK) repeats in the glutaminases were acquired early in their evolution. In order to obtain information on ANK folding, we solved two high-resolution structures of the ANK repeat-containing C termini of both kidney-type glutaminase (KGA) and GLS2 isoforms (glutaminase B and liver-type glutaminase). We also found that the glutaminase ANK repeats form unique intramolecular contacts through two highly conserved motifs; curiously, this arrangement occludes a region usually involved in ANK-mediated protein-protein interactions. We also solved the crystal structure of full-length KGA and present a small-angle X-ray scattering model for full-length GLS2. These structures explain these proteins' compromised ability to assemble into catalytically active supra-tetrameric filaments, as previously shown for GAC. Collectively, these results provide information about glutaminases that may aid in the design of isoform-specific glutaminase inhibitors.« less

Development of Global 30m Resolution Water Body Map with Permanent/Temporal Water Body Separation Using Satellite Acquired Images of Landsat GLS Datasets

NASA Astrophysics Data System (ADS)

Ikeshima, D.; Yamazaki, D.; Yoshikawa, S.; Kanae, S.

2015-12-01

The specification of worldwide water body distribution is important for discovering hydrological cycle. Global 3-second Water Body Map (G3WBM) is a global scale map, which indicates the distribution of water body in 90m resolutions (http://hydro.iis.u-tokyo.ac.jp/~yamadai/G3WBM/index.html). This dataset was mainly built to identify the width of river channels, which is one of major uncertainties of continental-scale river hydrodynamics models. To survey the true width of the river channel, this water body map distinguish Permanent Water Body from Temporary Water Body, which means separating river channel and flood plain. However, rivers with narrower width, which is a major case in usual river, could not be observed in this map. To overcome this problem, updating the algorithm of G3WBM and enhancing the resolutions to 30m is the goal of this research. Although this 30m-resolution water body map uses similar algorithm as G3WBM, there are many technical issues attributed to relatively high resolutions. Those are such as lack of same high-resolution digital elevation map, or contamination problem of sub-pixel scale object on satellite acquired image, or invisibility of well-vegetated water body such as swamp. To manage those issues, this research used more than 30,000 satellite images of Landsat Global Land Survey (GLS), and lately distributed topography data of Shuttle Rader Topography Mission (SRTM) 1 arc-second (30m) digital elevation map. Also the effect of aerosol, which would scatter the sun reflectance and disturb the acquired result image, was considered. Due to these revises, the global water body distribution was established in more precise resolution.

Surface wind mixing in the Regional Ocean Modeling System (ROMS)

NASA Astrophysics Data System (ADS)

Robertson, Robin; Hartlipp, Paul

2017-12-01

Mixing at the ocean surface is key for atmosphere-ocean interactions and the distribution of heat, energy, and gases in the upper ocean. Winds are the primary force for surface mixing. To properly simulate upper ocean dynamics and the flux of these quantities within the upper ocean, models must reproduce mixing in the upper ocean. To evaluate the performance of the Regional Ocean Modeling System (ROMS) in replicating the surface mixing, the results of four different vertical mixing parameterizations were compared against observations, using the surface mixed layer depth, the temperature fields, and observed diffusivities for comparisons. The vertical mixing parameterizations investigated were Mellor- Yamada 2.5 level turbulent closure (MY), Large- McWilliams- Doney Kpp (LMD), Nakanishi- Niino (NN), and the generic length scale (GLS) schemes. This was done for one temperate site in deep water in the Eastern Pacific and three shallow water sites in the Baltic Sea. The model reproduced the surface mixed layer depth reasonably well for all sites; however, the temperature fields were reproduced well for the deep site, but not for the shallow Baltic Sea sites. In the Baltic Sea, the models overmixed the water column after a few days. Vertical temperature diffusivities were higher than those observed and did not show the temporal fluctuations present in the observations. The best performance was by NN and MY; however, MY became unstable in two of the shallow simulations with high winds. The performance of GLS nearly as good as NN and MY. LMD had the poorest performance as it generated temperature diffusivities that were too high and induced too much mixing. Further observational comparisons are needed to evaluate the effects of different stratification and wind conditions and the limitations on the vertical mixing parameterizations.

Monitoring the long term stability of the IRS-P6 AWiFS sensor using the Sonoran and RVPN sites

NASA Astrophysics Data System (ADS)

Chander, Gyanesh; Sampath, Aparajithan; Angal, Amit; Choi, Taeyoung; Xiong, Xiaoxiong

2010-10-01

This paper focuses on radiometric and geometric assessment of the Indian Remote Sensing (IRS-P6) Advanced Wide Field Sensor (AWiFS) sensor using the Sonoran desert and Railroad Valley Playa, Nevada (RVPN) ground sites. Imageto- Image (I2I) accuracy and relative band-to-band (B2B) accuracy were measured. I2I accuracy of the AWiFS imagery was assessed by measuring the imagery against Landsat Global Land Survey (GLS) 2000. The AWiFS images were typically registered to within one pixel to the GLS 2000 mosaic images. The B2B process used the same concepts as the I2I, except instead of a reference image and a search image; the individual bands of a multispectral image are tested against each other. The B2B results showed that all the AWiFS multispectral bands are registered to sub-pixel accuracy. Using the limited amount of scenes available over these ground sites, the reflective bands of AWiFS sensor indicate a long-term drift in the top-of-atmosphere (TOA) reflectance. Because of the limited availability of AWiFS scenes over these ground sites, a comprehensive evaluation of the radiometric stability using these sites is not possible. In order to overcome this limitation, a cross-comparison between AWiFS and Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) was performed using image statistics based on large common areas observed by the sensors within 30 minutes. Regression curves and coefficients of determination for the TOA trends from these sensors were generated to quantify the uncertainty in these relationships and to provide an assessment of the calibration differences between these sensors.

Fontibacillus aquaticus gen. nov., sp. nov., isolated from a warm spring.

PubMed

Saha, P; Krishnamurthi, S; Bhattacharya, A; Sharma, R; Chakrabarti, T

2010-02-01

A novel facultatively anaerobic strain, designated GPTSA 19(T), was isolated from a warm spring and characterized using a polyphasic approach. The strain behaved as Gram-negative in the Gram staining procedure but showed a Gram-positive reaction in the aminopeptidase test. The novel strain was a mesophilic rod with ellipsoidal endospores. On the basis of 16S rRNA gene sequence analysis, the strain showed closest similarity (96.0 %) with Paenibacillus motobuensis MC10(T). The gene sequence similarity of the novel strain with other species of the genus Paenibacillus was <95.8 %. The novel strain also had PAEN 515F and 682F signature sequence stretches in the 16S rRNA gene that are usually found in most species of the genus Paenibacillus. The strain possessed anteiso-C(15 : 0) as the major fatty acid and MK-7 as the predominant menaquinone. Polar lipids included diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), six unknown phospholipids (PLs), one aminophospholipid (PN), three glycolipids (GLs), two aminolipids (ALs), one aminophosphoglycolipid (APGL) and three unknown lipids (ULs). The polar lipid profile of the novel strain, especially as regards ALs, GLs and PLs, distinguished it from the recognized type species of the genus Paenibacillus, Paenibacillus polymyxa, as well as from its closest relative P. motobuensis. Based on phenotypic and chemotaxonomic characteristics and analysis of the 16S rRNA gene sequence, the new strain merits the rank of a novel genus for which the name Fontibacillus gen. nov. is proposed. The type species of the new genus is Fontibacillus aquaticus gen. nov., sp. nov. with the type strain GPTSA 19(T) (=MTCC 7155(T)=DSM 17643(T)).

Enhanced production of polysaccharides and triterpenoids in Ganoderma lucidum fruit bodies on induction with signal transduction during the fruiting stage

PubMed Central

Xie, Fan; Zhao, Lili

2018-01-01

Ganoderma lucidum is a medicinal mushroom that has been widely used in East Asia for the treatment of various diseases. The pharmacological activity of this fungus is primarily attributable to the polysaccharides and triterpenoids. In this study, to obtain the fruit bodies with improved content of active constituents, we examined the effect of salicylic acid (SA) and calcium ion on the biosynthesis of polysaccharides and triterpenoids by spraying the chemicals during the fruiting. To explore the underlying mechanisms for the variation, the transcripts of related genes involved in the polysaccharide and triterpenoid biosynthesis were measured. Results showed that Ca2+ had no effect on production of polysaccharides and triterpenoids, whereas SA increased triterpenoid content by 23.32%, compared to the control, but it had little influence on polysaccharide production. Interestingly, the combined induction increased polysaccharide and triterpenoid content by 9.02% and 13.61%, respectively, compared to the control. Under Ca2+ induction, the transcript of ugp gene in the polysaccharide biosynthetic pathway up-regulated in all three stages (mycelium, primordium, and fruit body), while pgm and gls gave no response in the mycelium and primordium stages, and up-regulated in the fruit body stage. Differently, six key triterpenoid biosynthetic genes including hmgr, hmgs, mvd, fps, sqs, and ls did not respond to the induction. In the case of SA and combined induction, pgm and ugp were up-regulated in all three stages, while gls showed an increased expression in the primordium stage and no response in other stages. The six triterpenoid biosynthetic genes were up-regulated in all three stages. The present study provides a useful approach to producing G. lucidum fruit bodies with high polysaccharide and triterpenoid content. This is important to the G. lucidum industry. PMID:29694432

Protein phosphatase 2ACα gene knock-out results in cortical atrophy through activating hippo cascade in neuronal progenitor cells.

PubMed

Liu, Bo; Sun, Li-Hua; Huang, Yan-Fei; Guo, Li-Jun; Luo, Li-Shu

2018-02-01

Protein phosphatase 2ACα (PP2ACα), a vital member of the protein phosphatase family, has been studied primarily as a regulator for the development, growth and protein synthesis of a lot of cell types. Dysfunction of PP2ACα protein results in neurodegenerative disease; however, this finding has not been directly confirmed in the mouse model with PP2ACα gene knock-out. Therefore, in this study presented here, we generated the PP2ACα gene knock-out mouse model by the Cre-loxP targeting gene system, with the purpose to directly observe the regulatory role of PP2ACα gene in the development of mouse's cerebral cortex. We observe that knocking-out PP2ACα gene in the central nervous system (CNS) results in cortical neuronal shrinkage, synaptic plasticity impairments, and learning/memory deficits. Further study reveals that PP2ACα gene knock-out initiates Hippo cascade in cortical neuroprogenitor cells (NPCs), which blocks YAP translocation into the nuclei of NPCs. Notably, p73, directly targeted by Hippo cascade, can bind to the promoter of glutaminase2 (GLS2) that plays a dominant role in the enzymatic regulation of glutamate/glutamine cycle. Finally, we find that PP2ACα gene knock-out inhibits the glutamine synthesis through up-regulating the activity of phosphorylated-p73 in cortical NPCs. Taken together, it concludes that PP2ACα critically supports cortical neuronal growth and cognitive function via regulating the signaling transduction of Hippo-p73 cascade. And PP2ACα indirectly modulates the glutamine synthesis of cortical NPCs through targeting p73 that plays a direct transcriptional regulatory role in the gene expression of GLS2. Copyright © 2017 Elsevier Ltd. All rights reserved.

The origin and evolution of human glutaminases and their atypical C-terminal ankyrin repeats

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

Pasquali, Camila Cristina; Islam, Zeyaul; Adamoski, Douglas

On the basis of tissue-specific enzyme activity and inhibition by catalytic products, Hans Krebs first demonstrated the existence of multiple glutaminases in mammals. Currently, two human genes are known to encode at least four glutaminase isoforms. But, the phylogeny of these medically relevant enzymes remains unclear, prompting us to investigate their origin and evolution. Using prokaryotic and eukaryotic glutaminase sequences, we built a phylogenetic tree whose topology suggested that the multidomain architecture was inherited from bacterial ancestors, probably simultaneously with the hosting of the proto-mitochondrion endosymbiont. We propose an evolutionary model wherein the appearance of the most active enzyme isoform,more » glutaminase C (GAC), which is expressed in many cancers, was a late retrotransposition event that occurred in fishes from the Chondrichthyes class. The ankyrin (ANK) repeats in the glutaminases were acquired early in their evolution. In order to obtain information on ANK folding, we solved two high-resolution structures of the ANK repeat-containing C termini of both kidney-type glutaminase (KGA) and GLS2 isoforms (glutaminase B and liver-type glutaminase). We also found that the glutaminase ANK repeats form unique intramolecular contacts through two highly conserved motifs; curiously, this arrangement occludes a region usually involved in ANK-mediated protein-protein interactions. We also solved the crystal structure of full-length KGA and present a small-angle X-ray scattering model for full-length GLS2. These structures explain these proteins' compromised ability to assemble into catalytically active supra-tetrameric filaments, as previously shown for GAC. Collectively, these results provide information about glutaminases that may aid in the design of isoform-specific glutaminase inhibitors.« less

Application of least median of squared orthogonal distance (LMD) and LMD-based reweighted least squares (RLS) methods on the stock-recruitment relationship

NASA Astrophysics Data System (ADS)

Wang, Yan-Jun; Liu, Qun

1999-03-01

Analysis of stock-recruitment (SR) data is most often done by fitting various SR relationship curves to the data. Fish population dynamics data often have stochastic variations and measurement errors, which usually result in a biased regression analysis. This paper presents a robust regression method, least median of squared orthogonal distance (LMD), which is insensitive to abnormal values in the dependent and independent variables in a regression analysis. Outliers that have significantly different variance from the rest of the data can be identified in a residual analysis. Then, the least squares (LS) method is applied to the SR data with defined outliers being down weighted. The application of LMD and LMD-based Reweighted Least Squares (RLS) method to simulated and real fisheries SR data is explored.

Economic and public policy implications of energy pricing in Costa Rica

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

Bourgoin, L.

The methods used in examining the role of pricing in energy policy development may apply to many oil-importing countries with foreign exchange constraints. Data are developed by economic sectors on output plus on real factor inputs and factor wages for capital (by a perpetual inventory method), labor and useful energy (adjusted for efficiencies). A constant elasticity of substitution production model using 1965-1982 aggregate energy and nonenergy inputs is used to demonstrate the energy-economy linkages in Costa Rica. Estimates are from the best linear unbiased estimator and from the nonlinear system (structural form) of simultaneous equations jointly estimated by GLS multivariatemore » methods. The elasticity of substitution is 0.98 using only energy source costs and about 0.87-0.89 using energy system costs. The macroeconomic impacts of energy taxation or subsidization in Costa Rica for the range of likely values of the elasticity of substitution suggest that a small energy tax would result in a net national economic gain. Eight energy policy proposals demand management interventions and supply-side enhancements) are formulated for Costa Rica and qualified for five broad criteria according to their likelihood of success. These are chosen since they are believed to promote socioeconomic efficiency, to be politically feasible, and to be administratively implementable; the anticipated degree of popular acceptance and the size of the impact vary.« less

The Markers of Glutamate Metabolism in Peripheral Blood Mononuclear Cells and Neurological Complications in Lung Cancer Patients

PubMed Central

Ambrosius, Wojciech; Gazdulska, Joanna; Gołda-Gocka, Iwona; Kozubski, Wojciech; Ramlau, Rodryg

2016-01-01

Objective. To evaluate the involvement of glutamate metabolism in peripheral blood mononuclear cells (PBMC) in the development of neurological complications in lung cancer and during chemotherapy. Methods. The prospective study included 221 lung cancer patients treated with chemotherapeutics. Neurological status and cognitive functions were evaluated at baseline and after 6-month follow-up. Glutamate level, the activities of glutaminase- (GLS-) glutamate synthetizing enzyme, glutamate dehydrogenase (GDH), and glutamate decarboxylase catalyzing glutamate degradation were analyzed in PBMC and in sera of lung cancer patients by means of spectrophotometric and colorimetric methods. Results. Chemotherapy of lung neoplasms induced increase of glutamate content in PBMC and its concentration in serum increased the activity of GDH in PBMC and decreased activity of glutaminase in PBMC. The changes in glutamate metabolism markers were associated with initial manifestation of neurological deficit in lung cancer patients and with new symptoms, which appear as a complication of chemotherapy. Moreover, the analyzed parameters of glutamate control correlated with a spectrum of cognitive functions measures in lung cancer patients. Conclusion. We have demonstrated dysregulation in glutamate and glutamate metabolism controlling enzymes as promising indicators of risk for chemotherapy-induced neurological complications in lung cancer patients with particular emphasis on cognitive impairment. PMID:28044066

A spectral mimetic least-squares method

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

Bochev, Pavel; Gerritsma, Marc

We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less

A spectral mimetic least-squares method

DOE PAGES

Bochev, Pavel; Gerritsma, Marc

2014-09-01

We present a spectral mimetic least-squares method for a model diffusion–reaction problem, which preserves key conservation properties of the continuum problem. Casting the model problem into a first-order system for two scalar and two vector variables shifts material properties from the differential equations to a pair of constitutive relations. We also use this system to motivate a new least-squares functional involving all four fields and show that its minimizer satisfies the differential equations exactly. Discretization of the four-field least-squares functional by spectral spaces compatible with the differential operators leads to a least-squares method in which the differential equations are alsomore » satisfied exactly. Additionally, the latter are reduced to purely topological relationships for the degrees of freedom that can be satisfied without reference to basis functions. Furthermore, numerical experiments confirm the spectral accuracy of the method and its local conservation.« less

Adaptive slab laser beam quality improvement using a weighted least-squares reconstruction algorithm.

PubMed

Chen, Shanqiu; Dong, LiZhi; Chen, XiaoJun; Tan, Yi; Liu, Wenjin; Wang, Shuai; Yang, Ping; Xu, Bing; Ye, YuTang

2016-04-10

Adaptive optics is an important technology for improving beam quality in solid-state slab lasers. However, there are uncorrectable aberrations in partial areas of the beam. In the criterion of the conventional least-squares reconstruction method, it makes the zones with small aberrations nonsensitive and hinders this zone from being further corrected. In this paper, a weighted least-squares reconstruction method is proposed to improve the relative sensitivity of zones with small aberrations and to further improve beam quality. Relatively small weights are applied to the zones with large residual aberrations. Comparisons of results show that peak intensity in the far field improved from 1242 analog digital units (ADU) to 2248 ADU, and beam quality β improved from 2.5 to 2.0. This indicates the weighted least-squares method has better performance than the least-squares reconstruction method when there are large zonal uncorrectable aberrations in the slab laser system.

Fitting a function to time-dependent ensemble averaged data.

PubMed

Fogelmark, Karl; Lomholt, Michael A; Irbäck, Anders; Ambjörnsson, Tobias

2018-05-03

Time-dependent ensemble averages, i.e., trajectory-based averages of some observable, are of importance in many fields of science. A crucial objective when interpreting such data is to fit these averages (for instance, squared displacements) with a function and extract parameters (such as diffusion constants). A commonly overlooked challenge in such function fitting procedures is that fluctuations around mean values, by construction, exhibit temporal correlations. We show that the only available general purpose function fitting methods, correlated chi-square method and the weighted least squares method (which neglects correlation), fail at either robust parameter estimation or accurate error estimation. We remedy this by deriving a new closed-form error estimation formula for weighted least square fitting. The new formula uses the full covariance matrix, i.e., rigorously includes temporal correlations, but is free of the robustness issues, inherent to the correlated chi-square method. We demonstrate its accuracy in four examples of importance in many fields: Brownian motion, damped harmonic oscillation, fractional Brownian motion and continuous time random walks. We also successfully apply our method, weighted least squares including correlation in error estimation (WLS-ICE), to particle tracking data. The WLS-ICE method is applicable to arbitrary fit functions, and we provide a publically available WLS-ICE software.

A component prediction method for flue gas of natural gas combustion based on nonlinear partial least squares method.

PubMed

Cao, Hui; Yan, Xingyu; Li, Yaojiang; Wang, Yanxia; Zhou, Yan; Yang, Sanchun

2014-01-01

Quantitative analysis for the flue gas of natural gas-fired generator is significant for energy conservation and emission reduction. The traditional partial least squares method may not deal with the nonlinear problems effectively. In the paper, a nonlinear partial least squares method with extended input based on radial basis function neural network (RBFNN) is used for components prediction of flue gas. For the proposed method, the original independent input matrix is the input of RBFNN and the outputs of hidden layer nodes of RBFNN are the extension term of the original independent input matrix. Then, the partial least squares regression is performed on the extended input matrix and the output matrix to establish the components prediction model of flue gas. A near-infrared spectral dataset of flue gas of natural gas combustion is used for estimating the effectiveness of the proposed method compared with PLS. The experiments results show that the root-mean-square errors of prediction values of the proposed method for methane, carbon monoxide, and carbon dioxide are, respectively, reduced by 4.74%, 21.76%, and 5.32% compared to those of PLS. Hence, the proposed method has higher predictive capabilities and better robustness.

Genetic Local Search for Optimum Multiuser Detection Problem in DS-CDMA Systems

NASA Astrophysics Data System (ADS)

Wang, Shaowei; Ji, Xiaoyong

Optimum multiuser detection (OMD) in direct-sequence code-division multiple access (DS-CDMA) systems is an NP-complete problem. In this paper, we present a genetic local search algorithm, which consists of an evolution strategy framework and a local improvement procedure. The evolution strategy searches the space of feasible, locally optimal solutions only. A fast iterated local search algorithm, which employs the proprietary characteristics of the OMD problem, produces local optima with great efficiency. Computer simulations show the bit error rate (BER) performance of the GLS outperforms other multiuser detectors in all cases discussed. The computation time is polynomial complexity in the number of users.

Coherent Anomaly Method Calculation on the Cluster Variation Method. II.

NASA Astrophysics Data System (ADS)

Wada, Koh; Watanabe, Naotosi; Uchida, Tetsuya

The critical exponents of the bond percolation model are calculated in the D(= 2,3,…)-dimensional simple cubic lattice on the basis of Suzuki's coherent anomaly method (CAM) by making use of a series of the pair, the square-cactus and the square approximations of the cluster variation method (CVM) in the s-state Potts model. These simple approximations give reasonable values of critical exponents α, β, γ and ν in comparison with ones estimated by other methods. It is also shown that the results of the pair and the square-cactus approximations can be derived as exact results of the bond percolation model on the Bethe and the square-cactus lattice, respectively, in the presence of ghost field without recourse to the s→1 limit of the s-state Potts model.

Comparing least-squares and quantile regression approaches to analyzing median hospital charges.

PubMed

Olsen, Cody S; Clark, Amy E; Thomas, Andrea M; Cook, Lawrence J

2012-07-01

Emergency department (ED) and hospital charges obtained from administrative data sets are useful descriptors of injury severity and the burden to EDs and the health care system. However, charges are typically positively skewed due to costly procedures, long hospital stays, and complicated or prolonged treatment for few patients. The median is not affected by extreme observations and is useful in describing and comparing distributions of hospital charges. A least-squares analysis employing a log transformation is one approach for estimating median hospital charges, corresponding confidence intervals (CIs), and differences between groups; however, this method requires certain distributional properties. An alternate method is quantile regression, which allows estimation and inference related to the median without making distributional assumptions. The objective was to compare the log-transformation least-squares method to the quantile regression approach for estimating median hospital charges, differences in median charges between groups, and associated CIs. The authors performed simulations using repeated sampling of observed statewide ED and hospital charges and charges randomly generated from a hypothetical lognormal distribution. The median and 95% CI and the multiplicative difference between the median charges of two groups were estimated using both least-squares and quantile regression methods. Performance of the two methods was evaluated. In contrast to least squares, quantile regression produced estimates that were unbiased and had smaller mean square errors in simulations of observed ED and hospital charges. Both methods performed well in simulations of hypothetical charges that met least-squares method assumptions. When the data did not follow the assumed distribution, least-squares estimates were often biased, and the associated CIs had lower than expected coverage as sample size increased. Quantile regression analyses of hospital charges provide unbiased estimates even when lognormal and equal variance assumptions are violated. These methods may be particularly useful in describing and analyzing hospital charges from administrative data sets. © 2012 by the Society for Academic Emergency Medicine.

Ordinary Least Squares and Quantile Regression: An Inquiry-Based Learning Approach to a Comparison of Regression Methods

ERIC Educational Resources Information Center

Helmreich, James E.; Krog, K. Peter

2018-01-01

We present a short, inquiry-based learning course on concepts and methods underlying ordinary least squares (OLS), least absolute deviation (LAD), and quantile regression (QR). Students investigate squared, absolute, and weighted absolute distance functions (metrics) as location measures. Using differential calculus and properties of convex…

A method for simultaneously counterbalancing condition order and assignment of stimulus materials to conditions.

PubMed

Zeelenberg, René; Pecher, Diane

2015-03-01

Counterbalanced designs are frequently used in the behavioral sciences. Studies often counterbalance either the order in which conditions are presented in the experiment or the assignment of stimulus materials to conditions. Occasionally, researchers need to simultaneously counterbalance both condition order and stimulus assignment to conditions. Lewis (1989; Behavior Research Methods, Instruments, & Computers 25:414-415, 1993) presented a method for constructing Latin squares that fulfill these requirements. The resulting Latin squares counterbalance immediate sequential effects, but not remote sequential effects. Here, we present a new method for generating Latin squares that simultaneously counterbalance both immediate and remote sequential effects and assignment of stimuli to conditions. An Appendix is provided to facilitate implementation of these Latin square designs.

Simultaneous quantitative analysis of olmesartan, amlodipine and hydrochlorothiazide in their combined dosage form utilizing classical and alternating least squares based chemometric methods.

PubMed

Darwish, Hany W; Bakheit, Ahmed H; Abdelhameed, Ali S

2016-03-01

Simultaneous spectrophotometric analysis of a multi-component dosage form of olmesartan, amlodipine and hydrochlorothiazide used for the treatment of hypertension has been carried out using various chemometric methods. Multivariate calibration methods include classical least squares (CLS) executed by net analyte processing (NAP-CLS), orthogonal signal correction (OSC-CLS) and direct orthogonal signal correction (DOSC-CLS) in addition to multivariate curve resolution-alternating least squares (MCR-ALS). Results demonstrated the efficiency of the proposed methods as quantitative tools of analysis as well as their qualitative capability. The three analytes were determined precisely using the aforementioned methods in an external data set and in a dosage form after optimization of experimental conditions. Finally, the efficiency of the models was validated via comparison with the partial least squares (PLS) method in terms of accuracy and precision.

Generating Ground Reference Data for a Global Impervious Surface Survey

NASA Technical Reports Server (NTRS)

Tilton, James C.; deColstoun, Eric Brown; Wolfe, Robert E.; Tan, Bin; Huang, Chengquan

2012-01-01

We are engaged in a project to produce a 30m impervious cover data set of the entire Earth for the years 2000 and 2010 based on the Landsat Global Land Survey (GLS) data set. The GLS data from Landsat provide an unprecedented opportunity to map global urbanization at this resolution for the first time, with unprecedented detail and accuracy. Moreover, the spatial resolution of Landsat is absolutely essential to accurately resolve urban targets such as buildings, roads and parking lots. Finally, with GLS data available for the 1975, 1990, 2000, and 2005 time periods, and soon for the 2010 period, the land cover/use changes due to urbanization can now be quantified at this spatial scale as well. Our approach works across spatial scales using very high spatial resolution commercial satellite data to both produce and evaluate continental scale products at the 30m spatial resolution of Landsat data. We are developing continental scale training data at 1m or so resolution and aggregating these to 30m for training a regression tree algorithm. Because the quality of the input training data are critical, we have developed an interactive software tool, called HSegLearn, to facilitate the photo-interpretation of high resolution imagery data, such as Quickbird or Ikonos data, into an impervious versus non-impervious map. Previous work has shown that photo-interpretation of high resolution data at 1 meter resolution will generate an accurate 30m resolution ground reference when coarsened to that resolution. Since this process can be very time consuming when using standard clustering classification algorithms, we are looking at image segmentation as a potential avenue to not only improve the training process but also provide a semi-automated approach for generating the ground reference data. HSegLearn takes as its input a hierarchical set of image segmentations produced by the HSeg image segmentation program [1, 2]. HSegLearn lets an analyst specify pixel locations as being either positive or negative examples, and displays a classification of the study area based on these examples. For our study, the positive examples are examples of impervious surfaces and negative examples are examples of non-impervious surfaces. HSegLearn searches the hierarchical segmentation from HSeg for the coarsest level of segmentation at which selected positive example locations do not conflict with negative example locations and labels the image accordingly. The negative example regions are always defined at the finest level of segmentation detail. The resulting classification map can be then further edited at a region object level using the previously developed HSegViewer tool [3]. After providing an overview of the HSeg image segmentation program, we provide a detailed description of the HSegLearn software tool. We then give examples of using HSegLearn to generate ground reference data and conclude with comments on the effectiveness of the HSegLearn tool.

Coherent Anomaly Method Calculation on the Cluster Variation Method. II. Critical Exponents of Bond Percolation Model

NASA Astrophysics Data System (ADS)

Wada, Koh; Watanabe, Naotosi; Uchida, Tetsuya

1991-10-01

The critical exponents of the bond percolation model are calculated in the D(=2, 3, \\cdots)-dimensional simple cubic lattice on the basis of Suzuki’s coherent anomaly method (CAM) by making use of a series of the pair, the square-cactus and the square approximations of the cluster variation method (CVM) in the s-state Potts model. These simple approximations give reasonable values of critical exponents α, β, γ and ν in comparison with ones estimated by other methods. It is also shown that the results of the pair and the square-cactus approximations can be derived as exact results of the bond percolation model on the Bethe and the square-cactus lattice, respectively, in the presence of ghost field without recourse to the s→1 limit of the s-state Potts model.

[The research on separating and extracting overlapping spectral feature lines in LIBS using damped least squares method].

PubMed

Wang, Yin; Zhao, Nan-jing; Liu, Wen-qing; Yu, Yang; Fang, Li; Meng, De-shuo; Hu, Li; Zhang, Da-hai; Ma, Min-jun; Xiao, Xue; Wang, Yu; Liu, Jian-guo

2015-02-01

In recent years, the technology of laser induced breakdown spectroscopy has been developed rapidly. As one kind of new material composition detection technology, laser induced breakdown spectroscopy can simultaneously detect multi elements fast and simply without any complex sample preparation and realize field, in-situ material composition detection of the sample to be tested. This kind of technology is very promising in many fields. It is very important to separate, fit and extract spectral feature lines in laser induced breakdown spectroscopy, which is the cornerstone of spectral feature recognition and subsequent elements concentrations inversion research. In order to realize effective separation, fitting and extraction of spectral feature lines in laser induced breakdown spectroscopy, the original parameters for spectral lines fitting before iteration were analyzed and determined. The spectral feature line of' chromium (Cr I : 427.480 nm) in fly ash gathered from a coal-fired power station, which was overlapped with another line(FeI: 427.176 nm), was separated from the other one and extracted by using damped least squares method. Based on Gauss-Newton iteration, damped least squares method adds damping factor to step and adjust step length dynamically according to the feedback information after each iteration, in order to prevent the iteration from diverging and make sure that the iteration could converge fast. Damped least squares method helps to obtain better results of separating, fitting and extracting spectral feature lines and give more accurate intensity values of these spectral feature lines: The spectral feature lines of chromium in samples which contain different concentrations of chromium were separated and extracted. And then, the intensity values of corresponding spectral lines were given by using damped least squares method and least squares method separately. The calibration curves were plotted, which showed the relationship between spectral line intensity values and chromium concentrations in different samples. And then their respective linear correlations were compared. The experimental results showed that the linear correlation of the intensity values of spectral feature lines and the concentrations of chromium in different samples, which was obtained by damped least squares method, was better than that one obtained by least squares method. And therefore, damped least squares method was stable, reliable and suitable for separating, fitting and extracting spectral feature lines in laser induced breakdown spectroscopy.

Three-dimensional Reconstruction of Scar Contracture-bearing Axilla and Digital Webs Using the Square Flap Method

PubMed Central

Huang, Chenyu

2014-01-01

Background: Joint scar contractures are characterized by tight bands of soft tissue that bridge the 2 ends of the joint like a web. Classical treatment methods such as Z-plasties are mainly based on 2-dimensional designs. Our square flap method is an alternative surgical method that restores the span of the web in a stereometric fashion, thereby reconstructing joint function. Methods: In total, 20 Japanese patients with joint scar contractures on the axillary (n = 10) or first digital web (n = 10) underwent square flap surgery. The maximum range of motion and commissure length were measured before and after surgery. A theoretical stereometric geometrical model of the square flap was established to compare it to the classical single (60 degree), 4-flap (45 degree), and 5-flap (60 degree) Z-plasties in terms of theoretical web reconstruction efficacy. Results: All cases achieved 100% contracture release. The maximum range of motion and web space improved after square flap surgery (P = 0.001). Stereometric geometrical modeling revealed that the standard square flap (α = 45 degree; β = 90 degree) yields a larger flap area, length/width ratio, and postsurgical commissure length than the Z-plasties. It can also be adapted by varying angles α and β, although certain angle thresholds must be met to obtain the stereometric advantages of this method. Conclusions: When used to treat joint scar contractures, the square flap method can fully span the web space in a stereometric manner, thus yielding a close-to-original shape and function. Compared with the classical Z-plasties, it also provides sufficient anatomical blood supply while imposing the least physiological tension on the adjacent skin. PMID:25289342

Analysis of stability for stochastic delay integro-differential equations.

PubMed

Zhang, Yu; Li, Longsuo

2018-01-01

In this paper, we concern stability of numerical methods applied to stochastic delay integro-differential equations. For linear stochastic delay integro-differential equations, it is shown that the mean-square stability is derived by the split-step backward Euler method without any restriction on step-size, while the Euler-Maruyama method could reproduce the mean-square stability under a step-size constraint. We also confirm the mean-square stability of the split-step backward Euler method for nonlinear stochastic delay integro-differential equations. The numerical experiments further verify the theoretical results.

The Use of Alternative Regression Methods in Social Sciences and the Comparison of Least Squares and M Estimation Methods in Terms of the Determination of Coefficient

ERIC Educational Resources Information Center

Coskuntuncel, Orkun

2013-01-01

The purpose of this study is two-fold; the first aim being to show the effect of outliers on the widely used least squares regression estimator in social sciences. The second aim is to compare the classical method of least squares with the robust M-estimator using the "determination of coefficient" (R[superscript 2]). For this purpose,…

Simplified Least Squares Shadowing sensitivity analysis for chaotic ODEs and PDEs

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

Chater, Mario, E-mail: chaterm@mit.edu; Ni, Angxiu, E-mail: niangxiu@mit.edu; Wang, Qiqi, E-mail: qiqi@mit.edu

This paper develops a variant of the Least Squares Shadowing (LSS) method, which has successfully computed the derivative for several chaotic ODEs and PDEs. The development in this paper aims to simplify Least Squares Shadowing method by improving how time dilation is treated. Instead of adding an explicit time dilation term as in the original method, the new variant uses windowing, which can be more efficient and simpler to implement, especially for PDEs.

New method to incorporate Type B uncertainty into least-squares procedures in radionuclide metrology.

PubMed

Han, Jubong; Lee, K B; Lee, Jong-Man; Park, Tae Soon; Oh, J S; Oh, Pil-Jei

2016-03-01

We discuss a new method to incorporate Type B uncertainty into least-squares procedures. The new method is based on an extension of the likelihood function from which a conventional least-squares function is derived. The extended likelihood function is the product of the original likelihood function with additional PDFs (Probability Density Functions) that characterize the Type B uncertainties. The PDFs are considered to describe one's incomplete knowledge on correction factors being called nuisance parameters. We use the extended likelihood function to make point and interval estimations of parameters in the basically same way as the least-squares function used in the conventional least-squares method is derived. Since the nuisance parameters are not of interest and should be prevented from appearing in the final result, we eliminate such nuisance parameters by using the profile likelihood. As an example, we present a case study for a linear regression analysis with a common component of Type B uncertainty. In this example we compare the analysis results obtained from using our procedure with those from conventional methods. Copyright © 2015. Published by Elsevier Ltd.

An algorithm for propagating the square-root covariance matrix in triangular form

NASA Technical Reports Server (NTRS)

Tapley, B. D.; Choe, C. Y.

1976-01-01

A method for propagating the square root of the state error covariance matrix in lower triangular form is described. The algorithm can be combined with any triangular square-root measurement update algorithm to obtain a triangular square-root sequential estimation algorithm. The triangular square-root algorithm compares favorably with the conventional sequential estimation algorithm with regard to computation time.

A simple method for processing data with least square method

NASA Astrophysics Data System (ADS)

Wang, Chunyan; Qi, Liqun; Chen, Yongxiang; Pang, Guangning

2017-08-01

The least square method is widely used in data processing and error estimation. The mathematical method has become an essential technique for parameter estimation, data processing, regression analysis and experimental data fitting, and has become a criterion tool for statistical inference. In measurement data analysis, the distribution of complex rules is usually based on the least square principle, i.e., the use of matrix to solve the final estimate and to improve its accuracy. In this paper, a new method is presented for the solution of the method which is based on algebraic computation and is relatively straightforward and easy to understand. The practicability of this method is described by a concrete example.

Avian leucocyte counting using the hemocytometer

USGS Publications Warehouse

Dein, F.J.; Wilson, A.; Fischer, D.; Langenberg, P.

1994-01-01

Automated methods for counting leucocytes in avian blood are not available because of the presence of nucleated erythrocytes and thrombocytes. Therefore, total white blood cell counts are performed by hand using a hemocytometer. The Natt and Herrick and the Unopette methods are the most common stain and diluent preparations for this procedure. Replicate hemocytometer counts using these two methods were performed on blood from four birds of different species. Cells present in each square of the hemocytometer were counted. Counting cells in the corner, side, or center hemocytometer squares produced statistically equivalent results; counting four squares per chamber provided a result similar to that obtained by counting nine squares; and the Unopette method was more precise for hemocytometer counting than was the Natt and Herrick method. The Unopette method is easier to learn and perform but is an indirect process, utilizing the differential count from a stained smear. The Natt and Herrick method is a direct total count, but cell identification is more difficult.

A Two-Layer Least Squares Support Vector Machine Approach to Credit Risk Assessment

NASA Astrophysics Data System (ADS)

Liu, Jingli; Li, Jianping; Xu, Weixuan; Shi, Yong

Least squares support vector machine (LS-SVM) is a revised version of support vector machine (SVM) and has been proved to be a useful tool for pattern recognition. LS-SVM had excellent generalization performance and low computational cost. In this paper, we propose a new method called two-layer least squares support vector machine which combines kernel principle component analysis (KPCA) and linear programming form of least square support vector machine. With this method sparseness and robustness is obtained while solving large dimensional and large scale database. A U.S. commercial credit card database is used to test the efficiency of our method and the result proved to be a satisfactory one.

New method for propagating the square root covariance matrix in triangular form. [using Kalman-Bucy filter

NASA Technical Reports Server (NTRS)

Choe, C. Y.; Tapley, B. D.

1975-01-01

A method proposed by Potter of applying the Kalman-Bucy filter to the problem of estimating the state of a dynamic system is described, in which the square root of the state error covariance matrix is used to process the observations. A new technique which propagates the covariance square root matrix in lower triangular form is given for the discrete observation case. The technique is faster than previously proposed algorithms and is well-adapted for use with the Carlson square root measurement algorithm.

An error analysis of least-squares finite element method of velocity-pressure-vorticity formulation for Stokes problem

NASA Technical Reports Server (NTRS)

Chang, Ching L.; Jiang, Bo-Nan

1990-01-01

A theoretical proof of the optimal rate of convergence for the least-squares method is developed for the Stokes problem based on the velocity-pressure-vorticity formula. The 2D Stokes problem is analyzed to define the product space and its inner product, and the a priori estimates are derived to give the finite-element approximation. The least-squares method is found to converge at the optimal rate for equal-order interpolation.

Two-dimensional wavefront reconstruction based on double-shearing and least squares fitting

NASA Astrophysics Data System (ADS)

Liang, Peiying; Ding, Jianping; Zhu, Yangqing; Dong, Qian; Huang, Yuhua; Zhu, Zhen

2017-06-01

The two-dimensional wavefront reconstruction method based on double-shearing and least squares fitting is proposed in this paper. Four one-dimensional phase estimates of the measured wavefront, which correspond to the two shears and the two orthogonal directions, could be calculated from the differential phase, which solves the problem of the missing spectrum, and then by using the least squares method the two-dimensional wavefront reconstruction could be done. The numerical simulations of the proposed algorithm are carried out to verify the feasibility of this method. The influence of noise generated from different shear amount and different intensity on the accuracy of the reconstruction is studied and compared with the results from the algorithm based on single-shearing and least squares fitting. Finally, a two-grating lateral shearing interference experiment is carried out to verify the wavefront reconstruction algorithm based on doubleshearing and least squares fitting.

A study of autonomous satellite navigation methods using the global positioning satellite system

NASA Technical Reports Server (NTRS)

Tapley, B. D.

1980-01-01

Special orbit determination algorithms were developed to accommodate the size and speed limitations of on-board computer systems of the NAVSTAR Global Positioning System. The algorithms use square root sequential filtering methods. A new method for the time update of the square root covariance matrix was also developed. In addition, the time update method was compared with another square root convariance propagation method to determine relative performance characteristics. Comparisions were based on the results of computer simulations of the LANDSAT-D satellite processing pseudo range and pseudo range-rate measurements from the phase one GPS. A summary of the comparison results is presented.

Least Squares Moving-Window Spectral Analysis.

PubMed

Lee, Young Jong

2017-08-01

Least squares regression is proposed as a moving-windows method for analysis of a series of spectra acquired as a function of external perturbation. The least squares moving-window (LSMW) method can be considered an extended form of the Savitzky-Golay differentiation for nonuniform perturbation spacing. LSMW is characterized in terms of moving-window size, perturbation spacing type, and intensity noise. Simulation results from LSMW are compared with results from other numerical differentiation methods, such as single-interval differentiation, autocorrelation moving-window, and perturbation correlation moving-window methods. It is demonstrated that this simple LSMW method can be useful for quantitative analysis of nonuniformly spaced spectral data with high frequency noise.

Three-dimensional Reconstruction of Scar Contracture-bearing Axilla and Digital Webs Using the Square Flap Method.

PubMed

Huang, Chenyu; Ogawa, Rei

2014-05-01

Joint scar contractures are characterized by tight bands of soft tissue that bridge the 2 ends of the joint like a web. Classical treatment methods such as Z-plasties are mainly based on 2-dimensional designs. Our square flap method is an alternative surgical method that restores the span of the web in a stereometric fashion, thereby reconstructing joint function. In total, 20 Japanese patients with joint scar contractures on the axillary (n = 10) or first digital web (n = 10) underwent square flap surgery. The maximum range of motion and commissure length were measured before and after surgery. A theoretical stereometric geometrical model of the square flap was established to compare it to the classical single (60 degree), 4-flap (45 degree), and 5-flap (60 degree) Z-plasties in terms of theoretical web reconstruction efficacy. All cases achieved 100% contracture release. The maximum range of motion and web space improved after square flap surgery (P = 0.001). Stereometric geometrical modeling revealed that the standard square flap (α = 45 degree; β = 90 degree) yields a larger flap area, length/width ratio, and postsurgical commissure length than the Z-plasties. It can also be adapted by varying angles α and β, although certain angle thresholds must be met to obtain the stereometric advantages of this method. When used to treat joint scar contractures, the square flap method can fully span the web space in a stereometric manner, thus yielding a close-to-original shape and function. Compared with the classical Z-plasties, it also provides sufficient anatomical blood supply while imposing the least physiological tension on the adjacent skin.

Simple and Reliable Determination of Intravoxel Incoherent Motion Parameters for the Differential Diagnosis of Head and Neck Tumors

PubMed Central

Sasaki, Miho; Sumi, Misa; Eida, Sato; Katayama, Ikuo; Hotokezaka, Yuka; Nakamura, Takashi

2014-01-01

Intravoxel incoherent motion (IVIM) imaging can characterize diffusion and perfusion of normal and diseased tissues, and IVIM parameters are authentically determined by using cumbersome least-squares method. We evaluated a simple technique for the determination of IVIM parameters using geometric analysis of the multiexponential signal decay curve as an alternative to the least-squares method for the diagnosis of head and neck tumors. Pure diffusion coefficients (D), microvascular volume fraction (f), perfusion-related incoherent microcirculation (D*), and perfusion parameter that is heavily weighted towards extravascular space (P) were determined geometrically (Geo D, Geo f, and Geo P) or by least-squares method (Fit D, Fit f, and Fit D*) in normal structures and 105 head and neck tumors. The IVIM parameters were compared for their levels and diagnostic abilities between the 2 techniques. The IVIM parameters were not able to determine in 14 tumors with the least-squares method alone and in 4 tumors with the geometric and least-squares methods. The geometric IVIM values were significantly different (p<0.001) from Fit values (+2±4% and −7±24% for D and f values, respectively). Geo D and Fit D differentiated between lymphomas and SCCs with similar efficacy (78% and 80% accuracy, respectively). Stepwise approaches using combinations of Geo D and Geo P, Geo D and Geo f, or Fit D and Fit D* differentiated between pleomorphic adenomas, Warthin tumors, and malignant salivary gland tumors with the same efficacy (91% accuracy = 21/23). However, a stepwise differentiation using Fit D and Fit f was less effective (83% accuracy = 19/23). Considering cumbersome procedures with the least squares method compared with the geometric method, we concluded that the geometric determination of IVIM parameters can be an alternative to least-squares method in the diagnosis of head and neck tumors. PMID:25402436

Generalizations of Tikhonov's regularized method of least squares to non-Euclidean vector norms

NASA Astrophysics Data System (ADS)

Volkov, V. V.; Erokhin, V. I.; Kakaev, V. V.; Onufrei, A. Yu.

2017-09-01

Tikhonov's regularized method of least squares and its generalizations to non-Euclidean norms, including polyhedral, are considered. The regularized method of least squares is reduced to mathematical programming problems obtained by "instrumental" generalizations of the Tikhonov lemma on the minimal (in a certain norm) solution of a system of linear algebraic equations with respect to an unknown matrix. Further studies are needed for problems concerning the development of methods and algorithms for solving reduced mathematical programming problems in which the objective functions and admissible domains are constructed using polyhedral vector norms.

Error analysis on squareness of multi-sensor integrated CMM for the multistep registration method

NASA Astrophysics Data System (ADS)

Zhao, Yan; Wang, Yiwen; Ye, Xiuling; Wang, Zhong; Fu, Luhua

2018-01-01

The multistep registration(MSR) method in [1] is to register two different classes of sensors deployed on z-arm of CMM(coordinate measuring machine): a video camera and a tactile probe sensor. In general, it is difficult to obtain a very precise registration result with a single common standard, instead, this method is achieved by measuring two different standards with a constant distance between them two which are fixed on a steel plate. Although many factors have been considered such as the measuring ability of sensors, the uncertainty of the machine and the number of data pairs, there is no exact analysis on the squareness between the x-axis and the y-axis on the xy plane. For this sake, error analysis on the squareness of multi-sensor integrated CMM for the multistep registration method will be made to examine the validation of the MSR method. Synthetic experiments on the squareness on the xy plane for the simplified MSR with an inclination rotation are simulated, which will lead to a regular result. Experiments have been carried out with the multi-standard device designed also in [1], meanwhile, inspections with the help of a laser interferometer on the xy plane have been carried out. The final results are conformed to the simulations, and the squareness errors of the MSR method are also similar to the results of interferometer. In other word, the MSR can also adopted/utilized to verify the squareness of a CMM.

Latin and Magic Squares

ERIC Educational Resources Information Center

Emanouilidis, Emanuel

2005-01-01

Latin squares have existed for hundreds of years but it wasn't until rather recently that Latin squares were used in other areas such as statistics, graph theory, coding theory and the generation of random numbers as well as in the design and analysis of experiments. This note describes Latin and diagonal Latin squares, a method of constructing…

Uncertainty based pressure reconstruction from velocity measurement with generalized least squares

NASA Astrophysics Data System (ADS)

Zhang, Jiacheng; Scalo, Carlo; Vlachos, Pavlos

2017-11-01

A method using generalized least squares reconstruction of instantaneous pressure field from velocity measurement and velocity uncertainty is introduced and applied to both planar and volumetric flow data. Pressure gradients are computed on a staggered grid from flow acceleration. The variance-covariance matrix of the pressure gradients is evaluated from the velocity uncertainty by approximating the pressure gradient error to a linear combination of velocity errors. An overdetermined system of linear equations which relates the pressure and the computed pressure gradients is formulated and then solved using generalized least squares with the variance-covariance matrix of the pressure gradients. By comparing the reconstructed pressure field against other methods such as solving the pressure Poisson equation, the omni-directional integration, and the ordinary least squares reconstruction, generalized least squares method is found to be more robust to the noise in velocity measurement. The improvement on pressure result becomes more remarkable when the velocity measurement becomes less accurate and more heteroscedastic. The uncertainty of the reconstructed pressure field is also quantified and compared across the different methods.

Analysis of Nonlinear Dynamics by Square Matrix Method

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

Yu, Li Hua

The nonlinear dynamics of a system with periodic structure can be analyzed using a square matrix. In this paper, we show that because the special property of the square matrix constructed for nonlinear dynamics, we can reduce the dimension of the matrix from the original large number for high order calculation to low dimension in the first step of the analysis. Then a stable Jordan decomposition is obtained with much lower dimension. The transformation to Jordan form provides an excellent action-angle approximation to the solution of the nonlinear dynamics, in good agreement with trajectories and tune obtained from tracking. Andmore » more importantly, the deviation from constancy of the new action-angle variable provides a measure of the stability of the phase space trajectories and their tunes. Thus the square matrix provides a novel method to optimize the nonlinear dynamic system. The method is illustrated by many examples of comparison between theory and numerical simulation. Finally, in particular, we show that the square matrix method can be used for optimization to reduce the nonlinearity of a system.« less

Understanding Least Squares through Monte Carlo Calculations

ERIC Educational Resources Information Center

Tellinghuisen, Joel

2005-01-01

The method of least squares (LS) is considered as an important data analysis tool available to physical scientists. The mathematics of linear least squares(LLS) is summarized in a very compact matrix rotation that renders it practically "formulaic".

Landsat-4 (TDRSS-user) orbit determination using batch least-squares and sequential methods

NASA Technical Reports Server (NTRS)

Oza, D. H.; Jones, T. L.; Hakimi, M.; Samii, M. V.; Doll, C. E.; Mistretta, G. D.; Hart, R. C.

1992-01-01

TDRSS user orbit determination is analyzed using a batch least-squares method and a sequential estimation method. It was found that in the batch least-squares method analysis, the orbit determination consistency for Landsat-4, which was heavily tracked by TDRSS during January 1991, was about 4 meters in the rms overlap comparisons and about 6 meters in the maximum position differences in overlap comparisons. The consistency was about 10 to 30 meters in the 3 sigma state error covariance function in the sequential method analysis. As a measure of consistency, the first residual of each pass was within the 3 sigma bound in the residual space.

Total variation superiorized conjugate gradient method for image reconstruction

NASA Astrophysics Data System (ADS)

Zibetti, Marcelo V. W.; Lin, Chuan; Herman, Gabor T.

2018-03-01

The conjugate gradient (CG) method is commonly used for the relatively-rapid solution of least squares problems. In image reconstruction, the problem can be ill-posed and also contaminated by noise; due to this, approaches such as regularization should be utilized. Total variation (TV) is a useful regularization penalty, frequently utilized in image reconstruction for generating images with sharp edges. When a non-quadratic norm is selected for regularization, as is the case for TV, then it is no longer possible to use CG. Non-linear CG is an alternative, but it does not share the efficiency that CG shows with least squares and methods such as fast iterative shrinkage-thresholding algorithms (FISTA) are preferred for problems with TV norm. A different approach to including prior information is superiorization. In this paper it is shown that the conjugate gradient method can be superiorized. Five different CG variants are proposed, including preconditioned CG. The CG methods superiorized by the total variation norm are presented and their performance in image reconstruction is demonstrated. It is illustrated that some of the proposed variants of the superiorized CG method can produce reconstructions of superior quality to those produced by FISTA and in less computational time, due to the speed of the original CG for least squares problems. In the Appendix we examine the behavior of one of the superiorized CG methods (we call it S-CG); one of its input parameters is a positive number ɛ. It is proved that, for any given ɛ that is greater than the half-squared-residual for the least squares solution, S-CG terminates in a finite number of steps with an output for which the half-squared-residual is less than or equal to ɛ. Importantly, it is also the case that the output will have a lower value of TV than what would be provided by unsuperiorized CG for the same value ɛ of the half-squared residual.

Using Least Squares for Error Propagation

ERIC Educational Resources Information Center

Tellinghuisen, Joel

2015-01-01

The method of least-squares (LS) has a built-in procedure for estimating the standard errors (SEs) of the adjustable parameters in the fit model: They are the square roots of the diagonal elements of the covariance matrix. This means that one can use least-squares to obtain numerical values of propagated errors by defining the target quantities as…

a Unified Matrix Polynomial Approach to Modal Identification

NASA Astrophysics Data System (ADS)

Allemang, R. J.; Brown, D. L.

1998-04-01

One important current focus of modal identification is a reformulation of modal parameter estimation algorithms into a single, consistent mathematical formulation with a corresponding set of definitions and unifying concepts. Particularly, a matrix polynomial approach is used to unify the presentation with respect to current algorithms such as the least-squares complex exponential (LSCE), the polyreference time domain (PTD), Ibrahim time domain (ITD), eigensystem realization algorithm (ERA), rational fraction polynomial (RFP), polyreference frequency domain (PFD) and the complex mode indication function (CMIF) methods. Using this unified matrix polynomial approach (UMPA) allows a discussion of the similarities and differences of the commonly used methods. the use of least squares (LS), total least squares (TLS), double least squares (DLS) and singular value decomposition (SVD) methods is discussed in order to take advantage of redundant measurement data. Eigenvalue and SVD transformation methods are utilized to reduce the effective size of the resulting eigenvalue-eigenvector problem as well.

Analysis and computation of a least-squares method for consistent mesh tying

DOE PAGES

Day, David; Bochev, Pavel

2007-07-10

We report in the finite element method, a standard approach to mesh tying is to apply Lagrange multipliers. If the interface is curved, however, discretization generally leads to adjoining surfaces that do not coincide spatially. Straightforward Lagrange multiplier methods lead to discrete formulations failing a first-order patch test [T.A. Laursen, M.W. Heinstein, Consistent mesh-tying methods for topologically distinct discretized surfaces in non-linear solid mechanics, Internat. J. Numer. Methods Eng. 57 (2003) 1197–1242]. This paper presents a theoretical and computational study of a least-squares method for mesh tying [P. Bochev, D.M. Day, A least-squares method for consistent mesh tying, Internat. J.more » Numer. Anal. Modeling 4 (2007) 342–352], applied to the partial differential equation -∇ 2φ+αφ=f. We prove optimal convergence rates for domains represented as overlapping subdomains and show that the least-squares method passes a patch test of the order of the finite element space by construction. To apply the method to subdomain configurations with gaps and overlaps we use interface perturbations to eliminate the gaps. Finally, theoretical error estimates are illustrated by numerical experiments.« less

Missing value imputation in DNA microarrays based on conjugate gradient method.

PubMed

Dorri, Fatemeh; Azmi, Paeiz; Dorri, Faezeh

2012-02-01

Analysis of gene expression profiles needs a complete matrix of gene array values; consequently, imputation methods have been suggested. In this paper, an algorithm that is based on conjugate gradient (CG) method is proposed to estimate missing values. k-nearest neighbors of the missed entry are first selected based on absolute values of their Pearson correlation coefficient. Then a subset of genes among the k-nearest neighbors is labeled as the best similar ones. CG algorithm with this subset as its input is then used to estimate the missing values. Our proposed CG based algorithm (CGimpute) is evaluated on different data sets. The results are compared with sequential local least squares (SLLSimpute), Bayesian principle component analysis (BPCAimpute), local least squares imputation (LLSimpute), iterated local least squares imputation (ILLSimpute) and adaptive k-nearest neighbors imputation (KNNKimpute) methods. The average of normalized root mean squares error (NRMSE) and relative NRMSE in different data sets with various missing rates shows CGimpute outperforms other methods. Copyright © 2011 Elsevier Ltd. All rights reserved.

Penalized Nonlinear Least Squares Estimation of Time-Varying Parameters in Ordinary Differential Equations

PubMed Central

Cao, Jiguo; Huang, Jianhua Z.; Wu, Hulin

2012-01-01

Ordinary differential equations (ODEs) are widely used in biomedical research and other scientific areas to model complex dynamic systems. It is an important statistical problem to estimate parameters in ODEs from noisy observations. In this article we propose a method for estimating the time-varying coefficients in an ODE. Our method is a variation of the nonlinear least squares where penalized splines are used to model the functional parameters and the ODE solutions are approximated also using splines. We resort to the implicit function theorem to deal with the nonlinear least squares objective function that is only defined implicitly. The proposed penalized nonlinear least squares method is applied to estimate a HIV dynamic model from a real dataset. Monte Carlo simulations show that the new method can provide much more accurate estimates of functional parameters than the existing two-step local polynomial method which relies on estimation of the derivatives of the state function. Supplemental materials for the article are available online. PMID:23155351

Measurement System Characterization in the Presence of Measurement Errors

NASA Technical Reports Server (NTRS)

Commo, Sean A.

2012-01-01

In the calibration of a measurement system, data are collected in order to estimate a mathematical model between one or more factors of interest and a response. Ordinary least squares is a method employed to estimate the regression coefficients in the model. The method assumes that the factors are known without error; yet, it is implicitly known that the factors contain some uncertainty. In the literature, this uncertainty is known as measurement error. The measurement error affects both the estimates of the model coefficients and the prediction, or residual, errors. There are some methods, such as orthogonal least squares, that are employed in situations where measurement errors exist, but these methods do not directly incorporate the magnitude of the measurement errors. This research proposes a new method, known as modified least squares, that combines the principles of least squares with knowledge about the measurement errors. This knowledge is expressed in terms of the variance ratio - the ratio of response error variance to measurement error variance.

System and Method for Determining Rate of Rotation Using Brushless DC Motor

NASA Technical Reports Server (NTRS)

Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

2000-01-01

A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is squared. The squared outputs associated with each winding are combined, with the square root being taken of such combination, to produce a DC output proportional only to the rate of rotation of the motor's shaft.

Method for interconverting drying and heating times between round and square cross sections of ponderosa pine

Treesearch

William T. Simpson

2005-01-01

To use small-diameter trees effectively as square timbers, we need to be able to estimate the amount of time it takes for these timbers to air-dry. Since experimental data on estimating air-drying time for small-diameter logs have been developed, this study looked at a way to relate that method to square timbers. Drying times were determined for a group of round cross-...

Direct comparison of cardiac magnetic resonance feature tracking and 2D/3D echocardiography speckle tracking for evaluation of global left ventricular strain.

PubMed

Obokata, Masaru; Nagata, Yasufumi; Wu, Victor Chien-Chia; Kado, Yuichiro; Kurabayashi, Masahiko; Otsuji, Yutaka; Takeuchi, Masaaki

2016-05-01

Cardiac magnetic resonance (CMR) feature tracking (FT) with steady-state free precession (SSFP) has advantages over traditional myocardial tagging to analyse left ventricular (LV) strain. However, direct comparisons of CMRFT and 2D/3D echocardiography speckle tracking (2/3DEST) for measurement of LV strain are limited. The aim of this study was to investigate the feasibility and reliability of CMRFT and 2D/3DEST for measurement of global LV strain. We enrolled 106 patients who agreed to undergo both CMR and 2D/3DE on the same day. SSFP images at multiple short-axis and three apical views were acquired. 2DE images from three levels of short-axis, three apical views, and 3D full-volume datasets were also acquired. Strain data were expressed as absolute values. Feasibility was highest in CMRFT, followed by 2DEST and 3DEST. Analysis time was shortest in 3DEST, followed by CMRFT and 2DEST. There was good global longitudinal strain (GLS) correlation between CMRFT and 2D/3DEST (r = 0.83 and 0.87, respectively) with the limit of agreement (LOA) ranged from ±3.6 to ±4.9%. Excellent global circumferential strain (GCS) correlation between CMRFT and 2D/3DEST was observed (r = 0.90 and 0.88) with LOA of ±6.8-8.5%. Global radial strain showed fair correlations (r = 0.69 and 0.82, respectively) with LOA ranged from ±12.4 to ±16.3%. CMRFT GCS showed least observer variability with highest intra-class correlation. Although not interchangeable, the high GLS and GCS correlation between CMRFT and 2D/3DEST makes CMRFT a useful modality for quantification of global LV strain in patients, especially those with suboptimal echo image quality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Genes involved in muscle contractility and nutrient signaling pathways within celiac disease risk loci show differential mRNA expression.

PubMed

Montén, Caroline; Gudjonsdottir, Audur H; Browaldh, Lars; Arnell, Henrik; Nilsson, Staffan; Agardh, Daniel; Naluai, Åsa Torinsson

2015-06-30

Risk gene variants for celiac disease, identified in genome-wide linkage and association studies, might influence molecular pathways important for disease development. The aim was to examine expression levels of potential risk genes close to these variants in the small intestine and peripheral blood and also to test if the non-coding variants affect nearby gene expression levels in children with celiac disease. Intestinal biopsy and peripheral blood RNA was isolated from 167 children with celiac disease, 61 with potential celiac disease and 174 disease controls. Transcript levels for 88 target genes, selected from celiac disease risk loci, were analyzed in biopsies of a smaller sample subset by qPCR. Differentially expressed genes (3 from the pilot and 8 previously identified) were further validated in the larger sample collection (n = 402) of both tissues and correlated to nearby celiac disease risk variants. All genes were significantly down- or up-regulated in the intestinal mucosa of celiac disease children, NTS being most down-regulated (Fold change 3.6, p < 0.001). In contrast, PPP1R12B isoform C was up-regulated in the celiac disease mucosa (Fold change 1.9, p < 0.001). Allele specific expression of GLS (rs6741418, p = 0.009), INSR (rs7254060, p = 0.003) and NCALD (rs652008, p = 0.005) was also detected in the biopsies. Two genes (APPL2 and NCALD) were differentially expressed in peripheral blood but no allele specific expression was observed in this tissue. The differential expression of NTS and PPP1R12B indicate a potential role for smooth muscle contractility and cell proliferation in celiac disease, whereas other genes like GLS, NCALD and INSR suggests involvement of nutrient signaling and energy homeostasis in celiac disease pathogenesis. A disturbance in any of these pathways might contribute to development of childhood celiac disease.

Investigating the impact of surface wave breaking on modeling the trajectories of drifters in the northern Adriatic Sea during a wind-storm event

USGS Publications Warehouse

Carniel, S.; Warner, J.C.; Chiggiato, J.; Sclavo, M.

2009-01-01

An accurate numerical prediction of the oceanic upper layer velocity is a demanding requirement for many applications at sea and is a function of several near-surface processes that need to be incorporated in a numerical model. Among them, we assess the effects of vertical resolution, different vertical mixing parameterization (the so-called Generic Length Scale -GLS- set of k-??, k-??, gen, and the Mellor-Yamada), and surface roughness values on turbulent kinetic energy (k) injection from breaking waves. First, we modified the GLS turbulence closure formulation in the Regional Ocean Modeling System (ROMS) to incorporate the surface flux of turbulent kinetic energy due to wave breaking. Then, we applied the model to idealized test cases, exploring the sensitivity to the above mentioned factors. Last, the model was applied to a realistic situation in the Adriatic Sea driven by numerical meteorological forcings and river discharges. In this case, numerical drifters were released during an intense episode of Bora winds that occurred in mid-February 2003, and their trajectories compared to the displacement of satellite-tracked drifters deployed during the ADRIA02-03 sea-truth campaign. Results indicted that the inclusion of the wave breaking process helps improve the accuracy of the numerical simulations, subject to an increase in the typical value of the surface roughness z0. Specifically, the best performance was obtained using ??CH = 56,000 in the Charnok formula, the wave breaking parameterization activated, k-?? as the turbulence closure model. With these options, the relative error with respect to the average distance of the drifter was about 25% (5.5 km/day). The most sensitive factors in the model were found to be the value of ??CH enhanced with respect to a standard value, followed by the adoption of wave breaking parameterization and the particular turbulence closure model selected. ?? 2009 Elsevier Ltd.

A simple calculation method for determination of equivalent square field.

PubMed

Shafiei, Seyed Ali; Hasanzadeh, Hadi; Shafiei, Seyed Ahmad

2012-04-01

Determination of the equivalent square fields for rectangular and shielded fields is of great importance in radiotherapy centers and treatment planning software. This is accomplished using standard tables and empirical formulas. The goal of this paper is to present a formula based on analysis of scatter reduction due to inverse square law to obtain equivalent field. Tables are published by different agencies such as ICRU (International Commission on Radiation Units and measurements), which are based on experimental data; but there exist mathematical formulas that yield the equivalent square field of an irregular rectangular field which are used extensively in computation techniques for dose determination. These processes lead to some complicated and time-consuming formulas for which the current study was designed. In this work, considering the portion of scattered radiation in absorbed dose at a point of measurement, a numerical formula was obtained based on which a simple formula was developed to calculate equivalent square field. Using polar coordinate and inverse square law will lead to a simple formula for calculation of equivalent field. The presented method is an analytical approach based on which one can estimate the equivalent square field of a rectangular field and may be used for a shielded field or an off-axis point. Besides, one can calculate equivalent field of rectangular field with the concept of decreased scatter radiation with inverse square law with a good approximation. This method may be useful in computing Percentage Depth Dose and Tissue-Phantom Ratio which are extensively used in treatment planning.

Multi-element least square HDMR methods and their applications for stochastic multiscale model reduction

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

Jiang, Lijian, E-mail: ljjiang@hnu.edu.cn; Li, Xinping, E-mail: exping@126.com

Stochastic multiscale modeling has become a necessary approach to quantify uncertainty and characterize multiscale phenomena for many practical problems such as flows in stochastic porous media. The numerical treatment of the stochastic multiscale models can be very challengeable as the existence of complex uncertainty and multiple physical scales in the models. To efficiently take care of the difficulty, we construct a computational reduced model. To this end, we propose a multi-element least square high-dimensional model representation (HDMR) method, through which the random domain is adaptively decomposed into a few subdomains, and a local least square HDMR is constructed in eachmore » subdomain. These local HDMRs are represented by a finite number of orthogonal basis functions defined in low-dimensional random spaces. The coefficients in the local HDMRs are determined using least square methods. We paste all the local HDMR approximations together to form a global HDMR approximation. To further reduce computational cost, we present a multi-element reduced least-square HDMR, which improves both efficiency and approximation accuracy in certain conditions. To effectively treat heterogeneity properties and multiscale features in the models, we integrate multiscale finite element methods with multi-element least-square HDMR for stochastic multiscale model reduction. This approach significantly reduces the original model's complexity in both the resolution of the physical space and the high-dimensional stochastic space. We analyze the proposed approach, and provide a set of numerical experiments to demonstrate the performance of the presented model reduction techniques. - Highlights: • Multi-element least square HDMR is proposed to treat stochastic models. • Random domain is adaptively decomposed into some subdomains to obtain adaptive multi-element HDMR. • Least-square reduced HDMR is proposed to enhance computation efficiency and approximation accuracy in certain conditions. • Integrating MsFEM and multi-element least square HDMR can significantly reduce computation complexity.« less

Pyramidal space frame and associated methods

DOEpatents

Clark, Ryan Michael; White, David; Farr, Jr, Adrian Lawrence

2016-07-19

A space frame having a high torsional strength comprising a first square bipyramid and two planar structures extending outward from an apex of the first square bipyramid to form a "V" shape is disclosed. Some embodiments comprise a plurality of edge-sharing square bipyramids configured linearly, where the two planar structures contact apexes of all the square bipyramids. A plurality of bridging struts, apex struts, corner struts and optional internal bracing struts increase the strength and rigidity of the space frame. In an embodiment, the space frame supports a solar reflector, such as a parabolic solar reflector. Methods of fabricating and using the space frames are also disclosed.

Spacecraft inertia estimation via constrained least squares

NASA Technical Reports Server (NTRS)

Keim, Jason A.; Acikmese, Behcet A.; Shields, Joel F.

2006-01-01

This paper presents a new formulation for spacecraft inertia estimation from test data. Specifically, the inertia estimation problem is formulated as a constrained least squares minimization problem with explicit bounds on the inertia matrix incorporated as LMIs [linear matrix inequalities). The resulting minimization problem is a semidefinite optimization that can be solved efficiently with guaranteed convergence to the global optimum by readily available algorithms. This method is applied to data collected from a robotic testbed consisting of a freely rotating body. The results show that the constrained least squares approach produces more accurate estimates of the inertia matrix than standard unconstrained least squares estimation methods.

SIMULATIONS OF 2D AND 3D THERMOCAPILLARY FLOWS BY A LEAST-SQUARES FINITE ELEMENT METHOD. (R825200)

EPA Science Inventory

Numerical results for time-dependent 2D and 3D thermocapillary flows are presented in this work. The numerical algorithm is based on the Crank-Nicolson scheme for time integration, Newton's method for linearization, and a least-squares finite element method, together with a matri...

A new linear least squares method for T1 estimation from SPGR signals with multiple TRs

NASA Astrophysics Data System (ADS)

Chang, Lin-Ching; Koay, Cheng Guan; Basser, Peter J.; Pierpaoli, Carlo

2009-02-01

The longitudinal relaxation time, T1, can be estimated from two or more spoiled gradient recalled echo x (SPGR) images with two or more flip angles and one or more repetition times (TRs). The function relating signal intensity and the parameters are nonlinear; T1 maps can be computed from SPGR signals using nonlinear least squares regression. A widely-used linear method transforms the nonlinear model by assuming a fixed TR in SPGR images. This constraint is not desirable since multiple TRs are a clinically practical way to reduce the total acquisition time, to satisfy the required resolution, and/or to combine SPGR data acquired at different times. A new linear least squares method is proposed using the first order Taylor expansion. Monte Carlo simulations of SPGR experiments are used to evaluate the accuracy and precision of the estimated T1 from the proposed linear and the nonlinear methods. We show that the new linear least squares method provides T1 estimates comparable in both precision and accuracy to those from the nonlinear method, allowing multiple TRs and reducing computation time significantly.

A Least-Squares-Based Weak Galerkin Finite Element Method for Second Order Elliptic Equations

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

Mu, Lin; Wang, Junping; Ye, Xiu

Here, in this article, we introduce a least-squares-based weak Galerkin finite element method for the second order elliptic equation. This new method is shown to provide very accurate numerical approximations for both the primal and the flux variables. In contrast to other existing least-squares finite element methods, this new method allows us to use discontinuous approximating functions on finite element partitions consisting of arbitrary polygon/polyhedron shapes. We also develop a Schur complement algorithm for the resulting discretization problem by eliminating all the unknowns that represent the solution information in the interior of each element. Optimal order error estimates for bothmore » the primal and the flux variables are established. An extensive set of numerical experiments are conducted to demonstrate the robustness, reliability, flexibility, and accuracy of the least-squares-based weak Galerkin finite element method. Finally, the numerical examples cover a wide range of applied problems, including singularly perturbed reaction-diffusion equations and the flow of fluid in porous media with strong anisotropy and heterogeneity.« less

A Least-Squares-Based Weak Galerkin Finite Element Method for Second Order Elliptic Equations

DOE PAGES

Mu, Lin; Wang, Junping; Ye, Xiu

2017-08-17

Here, in this article, we introduce a least-squares-based weak Galerkin finite element method for the second order elliptic equation. This new method is shown to provide very accurate numerical approximations for both the primal and the flux variables. In contrast to other existing least-squares finite element methods, this new method allows us to use discontinuous approximating functions on finite element partitions consisting of arbitrary polygon/polyhedron shapes. We also develop a Schur complement algorithm for the resulting discretization problem by eliminating all the unknowns that represent the solution information in the interior of each element. Optimal order error estimates for bothmore » the primal and the flux variables are established. An extensive set of numerical experiments are conducted to demonstrate the robustness, reliability, flexibility, and accuracy of the least-squares-based weak Galerkin finite element method. Finally, the numerical examples cover a wide range of applied problems, including singularly perturbed reaction-diffusion equations and the flow of fluid in porous media with strong anisotropy and heterogeneity.« less

Speeding Fermat's factoring method

NASA Astrophysics Data System (ADS)

McKee, James

A factoring method is presented which, heuristically, splits composite n in O(n^{1/4+epsilon}) steps. There are two ideas: an integer approximation to sqrt(q/p) provides an O(n^{1/2+epsilon}) algorithm in which n is represented as the difference of two rational squares; observing that if a prime m divides a square, then m^2 divides that square, a heuristic speed-up to O(n^{1/4+epsilon}) steps is achieved. The method is well-suited for use with small computers: the storage required is negligible, and one never needs to work with numbers larger than n itself.

A unifying theoretical and algorithmic framework for least squares methods of estimation in diffusion tensor imaging.

PubMed

Koay, Cheng Guan; Chang, Lin-Ching; Carew, John D; Pierpaoli, Carlo; Basser, Peter J

2006-09-01

A unifying theoretical and algorithmic framework for diffusion tensor estimation is presented. Theoretical connections among the least squares (LS) methods, (linear least squares (LLS), weighted linear least squares (WLLS), nonlinear least squares (NLS) and their constrained counterparts), are established through their respective objective functions, and higher order derivatives of these objective functions, i.e., Hessian matrices. These theoretical connections provide new insights in designing efficient algorithms for NLS and constrained NLS (CNLS) estimation. Here, we propose novel algorithms of full Newton-type for the NLS and CNLS estimations, which are evaluated with Monte Carlo simulations and compared with the commonly used Levenberg-Marquardt method. The proposed methods have a lower percent of relative error in estimating the trace and lower reduced chi2 value than those of the Levenberg-Marquardt method. These results also demonstrate that the accuracy of an estimate, particularly in a nonlinear estimation problem, is greatly affected by the Hessian matrix. In other words, the accuracy of a nonlinear estimation is algorithm-dependent. Further, this study shows that the noise variance in diffusion weighted signals is orientation dependent when signal-to-noise ratio (SNR) is low (

Feasibility study on the least square method for fitting non-Gaussian noise data

NASA Astrophysics Data System (ADS)

Xu, Wei; Chen, Wen; Liang, Yingjie

2018-02-01

This study is to investigate the feasibility of least square method in fitting non-Gaussian noise data. We add different levels of the two typical non-Gaussian noises, Lévy and stretched Gaussian noises, to exact value of the selected functions including linear equations, polynomial and exponential equations, and the maximum absolute and the mean square errors are calculated for the different cases. Lévy and stretched Gaussian distributions have many applications in fractional and fractal calculus. It is observed that the non-Gaussian noises are less accurately fitted than the Gaussian noise, but the stretched Gaussian cases appear to perform better than the Lévy noise cases. It is stressed that the least-squares method is inapplicable to the non-Gaussian noise cases when the noise level is larger than 5%.

Method and structure for cache aware transposition via rectangular subsections

DOEpatents

Gustavson, Fred Gehrung; Gunnels, John A

2014-02-04

A method and structure for transposing a rectangular matrix A in a computer includes subdividing the rectangular matrix A into one or more square submatrices and executing an in-place transposition for each of the square submatrices A.sub.ij.

Estimation of parameters in rational reaction rates of molecular biological systems via weighted least squares

NASA Astrophysics Data System (ADS)

Wu, Fang-Xiang; Mu, Lei; Shi, Zhong-Ke

2010-01-01

The models of gene regulatory networks are often derived from statistical thermodynamics principle or Michaelis-Menten kinetics equation. As a result, the models contain rational reaction rates which are nonlinear in both parameters and states. It is challenging to estimate parameters nonlinear in a model although there have been many traditional nonlinear parameter estimation methods such as Gauss-Newton iteration method and its variants. In this article, we develop a two-step method to estimate the parameters in rational reaction rates of gene regulatory networks via weighted linear least squares. This method takes the special structure of rational reaction rates into consideration. That is, in the rational reaction rates, the numerator and the denominator are linear in parameters. By designing a special weight matrix for the linear least squares, parameters in the numerator and the denominator can be estimated by solving two linear least squares problems. The main advantage of the developed method is that it can produce the analytical solutions to the estimation of parameters in rational reaction rates which originally is nonlinear parameter estimation problem. The developed method is applied to a couple of gene regulatory networks. The simulation results show the superior performance over Gauss-Newton method.

An augmented classical least squares method for quantitative Raman spectral analysis against component information loss.

PubMed

Zhou, Yan; Cao, Hui

2013-01-01

We propose an augmented classical least squares (ACLS) calibration method for quantitative Raman spectral analysis against component information loss. The Raman spectral signals with low analyte concentration correlations were selected and used as the substitutes for unknown quantitative component information during the CLS calibration procedure. The number of selected signals was determined by using the leave-one-out root-mean-square error of cross-validation (RMSECV) curve. An ACLS model was built based on the augmented concentration matrix and the reference spectral signal matrix. The proposed method was compared with partial least squares (PLS) and principal component regression (PCR) using one example: a data set recorded from an experiment of analyte concentration determination using Raman spectroscopy. A 2-fold cross-validation with Venetian blinds strategy was exploited to evaluate the predictive power of the proposed method. The one-way variance analysis (ANOVA) was used to access the predictive power difference between the proposed method and existing methods. Results indicated that the proposed method is effective at increasing the robust predictive power of traditional CLS model against component information loss and its predictive power is comparable to that of PLS or PCR.

40 CFR Appendix C to Subpart Nnn... - Method for the Determination of Product Density

Code of Federal Regulations, 2013 CFR

2013-07-01

... One square foot (12 in. by 12 in.) template, or templates that are multiples of one square foot, for... to the plant's written procedure for the designated product. 3.2Cut samples using one square foot (or multiples of one square foot) template. 3.3Weigh product and obtain area weight (lb/ft2). 3.4Measure sample...

40 CFR Appendix C to Subpart Nnn... - Method for the Determination of Product Density

Code of Federal Regulations, 2014 CFR

2014-07-01

... One square foot (12 in. by 12 in.) template, or templates that are multiples of one square foot, for... to the plant's written procedure for the designated product. 3.2Cut samples using one square foot (or multiples of one square foot) template. 3.3Weigh product and obtain area weight (lb/ft2). 3.4Measure sample...

A fast least-squares algorithm for population inference

PubMed Central

2013-01-01

Background Population inference is an important problem in genetics used to remove population stratification in genome-wide association studies and to detect migration patterns or shared ancestry. An individual’s genotype can be modeled as a probabilistic function of ancestral population memberships, Q, and the allele frequencies in those populations, P. The parameters, P and Q, of this binomial likelihood model can be inferred using slow sampling methods such as Markov Chain Monte Carlo methods or faster gradient based approaches such as sequential quadratic programming. This paper proposes a least-squares simplification of the binomial likelihood model motivated by a Euclidean interpretation of the genotype feature space. This results in a faster algorithm that easily incorporates the degree of admixture within the sample of individuals and improves estimates without requiring trial-and-error tuning. Results We show that the expected value of the least-squares solution across all possible genotype datasets is equal to the true solution when part of the problem has been solved, and that the variance of the solution approaches zero as its size increases. The Least-squares algorithm performs nearly as well as Admixture for these theoretical scenarios. We compare least-squares, Admixture, and FRAPPE for a variety of problem sizes and difficulties. For particularly hard problems with a large number of populations, small number of samples, or greater degree of admixture, least-squares performs better than the other methods. On simulated mixtures of real population allele frequencies from the HapMap project, Admixture estimates sparsely mixed individuals better than Least-squares. The least-squares approach, however, performs within 1.5% of the Admixture error. On individual genotypes from the HapMap project, Admixture and least-squares perform qualitatively similarly and within 1.2% of each other. Significantly, the least-squares approach nearly always converges 1.5- to 6-times faster. Conclusions The computational advantage of the least-squares approach along with its good estimation performance warrants further research, especially for very large datasets. As problem sizes increase, the difference in estimation performance between all algorithms decreases. In addition, when prior information is known, the least-squares approach easily incorporates the expected degree of admixture to improve the estimate. PMID:23343408

A fast least-squares algorithm for population inference.

PubMed

Parry, R Mitchell; Wang, May D

2013-01-23

Population inference is an important problem in genetics used to remove population stratification in genome-wide association studies and to detect migration patterns or shared ancestry. An individual's genotype can be modeled as a probabilistic function of ancestral population memberships, Q, and the allele frequencies in those populations, P. The parameters, P and Q, of this binomial likelihood model can be inferred using slow sampling methods such as Markov Chain Monte Carlo methods or faster gradient based approaches such as sequential quadratic programming. This paper proposes a least-squares simplification of the binomial likelihood model motivated by a Euclidean interpretation of the genotype feature space. This results in a faster algorithm that easily incorporates the degree of admixture within the sample of individuals and improves estimates without requiring trial-and-error tuning. We show that the expected value of the least-squares solution across all possible genotype datasets is equal to the true solution when part of the problem has been solved, and that the variance of the solution approaches zero as its size increases. The Least-squares algorithm performs nearly as well as Admixture for these theoretical scenarios. We compare least-squares, Admixture, and FRAPPE for a variety of problem sizes and difficulties. For particularly hard problems with a large number of populations, small number of samples, or greater degree of admixture, least-squares performs better than the other methods. On simulated mixtures of real population allele frequencies from the HapMap project, Admixture estimates sparsely mixed individuals better than Least-squares. The least-squares approach, however, performs within 1.5% of the Admixture error. On individual genotypes from the HapMap project, Admixture and least-squares perform qualitatively similarly and within 1.2% of each other. Significantly, the least-squares approach nearly always converges 1.5- to 6-times faster. The computational advantage of the least-squares approach along with its good estimation performance warrants further research, especially for very large datasets. As problem sizes increase, the difference in estimation performance between all algorithms decreases. In addition, when prior information is known, the least-squares approach easily incorporates the expected degree of admixture to improve the estimate.

Three Perspectives on Teaching Least Squares

ERIC Educational Resources Information Center

Scariano, Stephen M.; Calzada, Maria

2004-01-01

The method of Least Squares is the most widely used technique for fitting a straight line to data, and it is typically discussed in several undergraduate courses. This article focuses on three developmentally different approaches for solving the Least Squares problem that are suitable for classroom exposition.

Highly Compact Circulators in Square-Lattice Photonic Crystal Waveguides

PubMed Central

Jin, Xin; Ouyang, Zhengbiao; Wang, Qiong; Lin, Mi; Wen, Guohua; Wang, Jingjing

2014-01-01

We propose, demonstrate and investigate highly compact circulators with ultra-low insertion loss in square-lattice- square-rod-photonic-crystal waveguides. Only a single magneto- optical square rod is required to be inserted into the cross center of waveguides, making the structure very compact and ultra efficient. The square rods around the center defect rod are replaced by several right-angled-triangle rods, reducing the insertion loss further and promoting the isolations as well. By choosing a linear-dispersion region and considering the mode patterns in the square magneto-optical rod, the operating mechanism of the circulator is analyzed. By applying the finite-element method together with the Nelder-Mead optimization method, an extremely low insertion loss of 0.02 dB for the transmitted wave and ultra high isolation of 46 dB∼48 dB for the isolated port are obtained. The idea presented can be applied to build circulators in different wavebands, e.g., microwave or Tera-Hertz. PMID:25415417

Highly compact circulators in square-lattice photonic crystal waveguides.

PubMed

Jin, Xin; Ouyang, Zhengbiao; Wang, Qiong; Lin, Mi; Wen, Guohua; Wang, Jingjing

2014-01-01

We propose, demonstrate and investigate highly compact circulators with ultra-low insertion loss in square-lattice- square-rod-photonic-crystal waveguides. Only a single magneto- optical square rod is required to be inserted into the cross center of waveguides, making the structure very compact and ultra efficient. The square rods around the center defect rod are replaced by several right-angled-triangle rods, reducing the insertion loss further and promoting the isolations as well. By choosing a linear-dispersion region and considering the mode patterns in the square magneto-optical rod, the operating mechanism of the circulator is analyzed. By applying the finite-element method together with the Nelder-Mead optimization method, an extremely low insertion loss of 0.02 dB for the transmitted wave and ultra high isolation of 46 dB∼48 dB for the isolated port are obtained. The idea presented can be applied to build circulators in different wavebands, e.g., microwave or Tera-Hertz.

Parameter estimation using weighted total least squares in the two-compartment exchange model.

PubMed

Garpebring, Anders; Löfstedt, Tommy

2018-01-01

The linear least squares (LLS) estimator provides a fast approach to parameter estimation in the linearized two-compartment exchange model. However, the LLS method may introduce a bias through correlated noise in the system matrix of the model. The purpose of this work is to present a new estimator for the linearized two-compartment exchange model that takes this noise into account. To account for the noise in the system matrix, we developed an estimator based on the weighted total least squares (WTLS) method. Using simulations, the proposed WTLS estimator was compared, in terms of accuracy and precision, to an LLS estimator and a nonlinear least squares (NLLS) estimator. The WTLS method improved the accuracy compared to the LLS method to levels comparable to the NLLS method. This improvement was at the expense of increased computational time; however, the WTLS was still faster than the NLLS method. At high signal-to-noise ratio all methods provided similar precisions while inconclusive results were observed at low signal-to-noise ratio. The proposed method provides improvements in accuracy compared to the LLS method, however, at an increased computational cost. Magn Reson Med 79:561-567, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

An analysis of the least-squares problem for the DSN systematic pointing error model

NASA Technical Reports Server (NTRS)

Alvarez, L. S.

1991-01-01

A systematic pointing error model is used to calibrate antennas in the Deep Space Network. The least squares problem is described and analyzed along with the solution methods used to determine the model's parameters. Specifically studied are the rank degeneracy problems resulting from beam pointing error measurement sets that incorporate inadequate sky coverage. A least squares parameter subset selection method is described and its applicability to the systematic error modeling process is demonstrated on Voyager 2 measurement distribution.

Rho GTPases and their roles in cancer metabolism

PubMed Central

Wilson, Kristin F.; Erickson, Jon W.; Antonyak, Marc A.; Cerione, Richard A.

2013-01-01

Recently, the small molecule 968 was found to block the Rho GTPase-dependent growth of cancer cells in cell culture and mouse xenografts, and when the target of 968 was found to be mitochondrial enzyme glutaminase (GLS1) it revealed a surprising link between Rho GTPases and mitochondrial glutamine metabolism. Signal transduction via the Rho GTPases, together with NFκB, appears to elevate mitochondrial glutaminase activity in cancer cells, thereby helping cancer cells satisfy their altered metabolic demands. Here, we review what is known about the mechanism of glutaminase activation in cancer cells, as well as compare the properties of two distinct glutaminase inhibitors, and discuss recent findings that shed new light on how glutamine metabolism might affect cancer progression. PMID:23219172

Establishment and Discontinuance Criteria for Airport Traffic Control Towers.

DTIC Science & Technology

1983-08-01

AR ASW 1 0.74 0.70 -539. HOT MINOT ND AOL 1 0.74 0.72 -509. LRD LAREDO TX ASW 1 0.76 0.72 -492. TXK TEXARKANA AR ASW 1 0.91 0.74 -462. FCN FRESNO CA...SFZ SMITHFIELD RI ANE 0 0.44 0.28 -2270. $IV AURORA CO ANN 0 0.40 0.25 -2387. ORO DURANGO CO ANN 0 0.49 0.43 -1791. 48V ERIE CO ANN 0 0.51 0.36 - 2017 ... 2017 . F70 FORT WORTH TX ASH 0 0.62 0.46 -1713. GLS GALVESTON TX ASW 0 0.83 0.69 -988. F67 GRAND PRAIRIE TX ASH 0 0.75 0.55 -1434. "Do HONDO TX ASW 0 1.77

A simple calculation method for determination of equivalent square field

PubMed Central

Shafiei, Seyed Ali; Hasanzadeh, Hadi; Shafiei, Seyed Ahmad

2012-01-01

Determination of the equivalent square fields for rectangular and shielded fields is of great importance in radiotherapy centers and treatment planning software. This is accomplished using standard tables and empirical formulas. The goal of this paper is to present a formula based on analysis of scatter reduction due to inverse square law to obtain equivalent field. Tables are published by different agencies such as ICRU (International Commission on Radiation Units and measurements), which are based on experimental data; but there exist mathematical formulas that yield the equivalent square field of an irregular rectangular field which are used extensively in computation techniques for dose determination. These processes lead to some complicated and time-consuming formulas for which the current study was designed. In this work, considering the portion of scattered radiation in absorbed dose at a point of measurement, a numerical formula was obtained based on which a simple formula was developed to calculate equivalent square field. Using polar coordinate and inverse square law will lead to a simple formula for calculation of equivalent field. The presented method is an analytical approach based on which one can estimate the equivalent square field of a rectangular field and may be used for a shielded field or an off-axis point. Besides, one can calculate equivalent field of rectangular field with the concept of decreased scatter radiation with inverse square law with a good approximation. This method may be useful in computing Percentage Depth Dose and Tissue-Phantom Ratio which are extensively used in treatment planning. PMID:22557801

Generalized Structured Component Analysis

ERIC Educational Resources Information Center

Hwang, Heungsun; Takane, Yoshio

2004-01-01

We propose an alternative method to partial least squares for path analysis with components, called generalized structured component analysis. The proposed method replaces factors by exact linear combinations of observed variables. It employs a well-defined least squares criterion to estimate model parameters. As a result, the proposed method…

Recursive least squares method of regression coefficients estimation as a special case of Kalman filter

NASA Astrophysics Data System (ADS)

Borodachev, S. M.

2016-06-01

The simple derivation of recursive least squares (RLS) method equations is given as special case of Kalman filter estimation of a constant system state under changing observation conditions. A numerical example illustrates application of RLS to multicollinearity problem.

Iterative and multigrid methods in the finite element solution of incompressible and turbulent fluid flow

NASA Astrophysics Data System (ADS)

Lavery, N.; Taylor, C.

1999-07-01

Multigrid and iterative methods are used to reduce the solution time of the matrix equations which arise from the finite element (FE) discretisation of the time-independent equations of motion of the incompressible fluid in turbulent motion. Incompressible flow is solved by using the method of reduce interpolation for the pressure to satisfy the Brezzi-Babuska condition. The k-l model is used to complete the turbulence closure problem. The non-symmetric iterative matrix methods examined are the methods of least squares conjugate gradient (LSCG), biconjugate gradient (BCG), conjugate gradient squared (CGS), and the biconjugate gradient squared stabilised (BCGSTAB). The multigrid algorithm applied is based on the FAS algorithm of Brandt, and uses two and three levels of grids with a V-cycling schedule. These methods are all compared to the non-symmetric frontal solver. Copyright

Storage and computationally efficient permutations of factorized covariance and square-root information matrices

NASA Technical Reports Server (NTRS)

Muellerschoen, R. J.

1988-01-01

A unified method to permute vector-stored upper-triangular diagonal factorized covariance (UD) and vector stored upper-triangular square-root information filter (SRIF) arrays is presented. The method involves cyclical permutation of the rows and columns of the arrays and retriangularization with appropriate square-root-free fast Givens rotations or elementary slow Givens reflections. A minimal amount of computation is performed and only one scratch vector of size N is required, where N is the column dimension of the arrays. To make the method efficient for large SRIF arrays on a virtual memory machine, three additional scratch vectors each of size N are used to avoid expensive paging faults. The method discussed is compared with the methods and routines of Bierman's Estimation Subroutine Library (ESL).

Numerical modelling of rapid, flow-like landslides across 3-D terrains: a Tsunami Squares approach to El Picacho landslide, El Salvador, September 19, 1982

NASA Astrophysics Data System (ADS)

Wang, Jiajia; Ward, Steven N.; Xiao, Lili

2015-06-01

Flow-like landslides are rapidly moving fluid-solid mixtures that can cause significant destruction along paths that run far from their original sources. Existing models for run out prediction and motion simulation of flow-like landslides have many limitations. In this paper, we develop a new method named `Tsunami Squares' to simulate the generation, propagation and stoppage of flow-like landslides based on conservation of volume and momentum. Landslide materials in the new method form divisible squares that are displaced, then further fractured. The squares move under the influence of gravity-driven acceleration and suffer decelerations due to basal and dynamic frictions. Distinctively, this method takes into account solid and fluid mechanics, particle interactions and flow regime transitions. We apply this approach to simulate the 1982 El Picacho landslide in San Salvador, capital city of El Salvador. Landslide products from Tsunami Squares such as run out distance, velocities, erosion and deposition depths and impacted area agree well with field investigated and eyewitness data.

An improved partial least-squares regression method for Raman spectroscopy

NASA Astrophysics Data System (ADS)

Momenpour Tehran Monfared, Ali; Anis, Hanan

2017-10-01

It is known that the performance of partial least-squares (PLS) regression analysis can be improved using the backward variable selection method (BVSPLS). In this paper, we further improve the BVSPLS based on a novel selection mechanism. The proposed method is based on sorting the weighted regression coefficients, and then the importance of each variable of the sorted list is evaluated using root mean square errors of prediction (RMSEP) criterion in each iteration step. Our Improved BVSPLS (IBVSPLS) method has been applied to leukemia and heparin data sets and led to an improvement in limit of detection of Raman biosensing ranged from 10% to 43% compared to PLS. Our IBVSPLS was also compared to the jack-knifing (simpler) and Genetic Algorithm (more complex) methods. Our method was consistently better than the jack-knifing method and showed either a similar or a better performance compared to the genetic algorithm.

Accuracy of least-squares methods for the Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Bochev, Pavel B.; Gunzburger, Max D.

1993-01-01

Recently there has been substantial interest in least-squares finite element methods for velocity-vorticity-pressure formulations of the incompressible Navier-Stokes equations. The main cause for this interest is the fact that algorithms for the resulting discrete equations can be devised which require the solution of only symmetric, positive definite systems of algebraic equations. On the other hand, it is well-documented that methods using the vorticity as a primary variable often yield very poor approximations. Thus, here we study the accuracy of these methods through a series of computational experiments, and also comment on theoretical error estimates. It is found, despite the failure of standard methods for deriving error estimates, that computational evidence suggests that these methods are, at the least, nearly optimally accurate. Thus, in addition to the desirable matrix properties yielded by least-squares methods, one also obtains accurate approximations.

Least-squares finite element methods for compressible Euler equations

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Carey, G. F.

1990-01-01

A method based on backward finite differencing in time and a least-squares finite element scheme for first-order systems of partial differential equations in space is applied to the Euler equations for gas dynamics. The scheme minimizes the L-sq-norm of the residual within each time step. The method naturally generates numerical dissipation proportional to the time step size. An implicit method employing linear elements has been implemented and proves robust. For high-order elements, computed solutions based on the L-sq method may have oscillations for calculations at similar time step sizes. To overcome this difficulty, a scheme which minimizes the weighted H1-norm of the residual is proposed and leads to a successful scheme with high-degree elements. Finally, a conservative least-squares finite element method is also developed. Numerical results for two-dimensional problems are given to demonstrate the shock resolution of the methods and compare different approaches.

Comparison between results of solution of Burgers' equation and Laplace's equation by Galerkin and least-square finite element methods

NASA Astrophysics Data System (ADS)

Adib, Arash; Poorveis, Davood; Mehraban, Farid

2018-03-01

In this research, two equations are considered as examples of hyperbolic and elliptic equations. In addition, two finite element methods are applied for solving of these equations. The purpose of this research is the selection of suitable method for solving each of two equations. Burgers' equation is a hyperbolic equation. This equation is a pure advection (without diffusion) equation. This equation is one-dimensional and unsteady. A sudden shock wave is introduced to the model. This wave moves without deformation. In addition, Laplace's equation is an elliptical equation. This equation is steady and two-dimensional. The solution of Laplace's equation in an earth dam is considered. By solution of Laplace's equation, head pressure and the value of seepage in the directions X and Y are calculated in different points of earth dam. At the end, water table is shown in the earth dam. For Burgers' equation, least-square method can show movement of wave with oscillation but Galerkin method can not show it correctly (the best method for solving of the Burgers' equation is discrete space by least-square finite element method and discrete time by forward difference.). For Laplace's equation, Galerkin and least square methods can show water table correctly in earth dam.

Estimators of The Magnitude-Squared Spectrum and Methods for Incorporating SNR Uncertainty

PubMed Central

Lu, Yang; Loizou, Philipos C.

2011-01-01

Statistical estimators of the magnitude-squared spectrum are derived based on the assumption that the magnitude-squared spectrum of the noisy speech signal can be computed as the sum of the (clean) signal and noise magnitude-squared spectra. Maximum a posterior (MAP) and minimum mean square error (MMSE) estimators are derived based on a Gaussian statistical model. The gain function of the MAP estimator was found to be identical to the gain function used in the ideal binary mask (IdBM) that is widely used in computational auditory scene analysis (CASA). As such, it was binary and assumed the value of 1 if the local SNR exceeded 0 dB, and assumed the value of 0 otherwise. By modeling the local instantaneous SNR as an F-distributed random variable, soft masking methods were derived incorporating SNR uncertainty. The soft masking method, in particular, which weighted the noisy magnitude-squared spectrum by the a priori probability that the local SNR exceeds 0 dB was shown to be identical to the Wiener gain function. Results indicated that the proposed estimators yielded significantly better speech quality than the conventional MMSE spectral power estimators, in terms of yielding lower residual noise and lower speech distortion. PMID:21886543

Use of partial least squares regression to impute SNP genotypes in Italian cattle breeds.

PubMed

Dimauro, Corrado; Cellesi, Massimo; Gaspa, Giustino; Ajmone-Marsan, Paolo; Steri, Roberto; Marras, Gabriele; Macciotta, Nicolò P P

2013-06-05

The objective of the present study was to test the ability of the partial least squares regression technique to impute genotypes from low density single nucleotide polymorphisms (SNP) panels i.e. 3K or 7K to a high density panel with 50K SNP. No pedigree information was used. Data consisted of 2093 Holstein, 749 Brown Swiss and 479 Simmental bulls genotyped with the Illumina 50K Beadchip. First, a single-breed approach was applied by using only data from Holstein animals. Then, to enlarge the training population, data from the three breeds were combined and a multi-breed analysis was performed. Accuracies of genotypes imputed using the partial least squares regression method were compared with those obtained by using the Beagle software. The impact of genotype imputation on breeding value prediction was evaluated for milk yield, fat content and protein content. In the single-breed approach, the accuracy of imputation using partial least squares regression was around 90 and 94% for the 3K and 7K platforms, respectively; corresponding accuracies obtained with Beagle were around 85% and 90%. Moreover, computing time required by the partial least squares regression method was on average around 10 times lower than computing time required by Beagle. Using the partial least squares regression method in the multi-breed resulted in lower imputation accuracies than using single-breed data. The impact of the SNP-genotype imputation on the accuracy of direct genomic breeding values was small. The correlation between estimates of genetic merit obtained by using imputed versus actual genotypes was around 0.96 for the 7K chip. Results of the present work suggested that the partial least squares regression imputation method could be useful to impute SNP genotypes when pedigree information is not available.

Least squares estimation of avian molt rates

USGS Publications Warehouse

Johnson, D.H.

1989-01-01

A straightforward least squares method of estimating the rate at which birds molt feathers is presented, suitable for birds captured more than once during the period of molt. The date of molt onset can also be estimated. The method is applied to male and female mourning doves.

Penalized Multi-Way Partial Least Squares for Smooth Trajectory Decoding from Electrocorticographic (ECoG) Recording

PubMed Central

Eliseyev, Andrey; Aksenova, Tetiana

2016-01-01

In the current paper the decoding algorithms for motor-related BCI systems for continuous upper limb trajectory prediction are considered. Two methods for the smooth prediction, namely Sobolev and Polynomial Penalized Multi-Way Partial Least Squares (PLS) regressions, are proposed. The methods are compared to the Multi-Way Partial Least Squares and Kalman Filter approaches. The comparison demonstrated that the proposed methods combined the prediction accuracy of the algorithms of the PLS family and trajectory smoothness of the Kalman Filter. In addition, the prediction delay is significantly lower for the proposed algorithms than for the Kalman Filter approach. The proposed methods could be applied in a wide range of applications beyond neuroscience. PMID:27196417

Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

2016-03-01

Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.

Multiway analysis methods applied to the fluorescence excitation-emission dataset for the simultaneous quantification of valsartan and amlodipine in tablets

NASA Astrophysics Data System (ADS)

Dinç, Erdal; Ertekin, Zehra Ceren; Büker, Eda

2017-09-01

In this study, excitation-emission matrix datasets, which have strong overlapping bands, were processed by using four different chemometric calibration algorithms consisting of parallel factor analysis, Tucker3, three-way partial least squares and unfolded partial least squares for the simultaneous quantitative estimation of valsartan and amlodipine besylate in tablets. In analyses, preliminary separation step was not used before the application of parallel factor analysis Tucker3, three-way partial least squares and unfolded partial least squares approaches for the analysis of the related drug substances in samples. Three-way excitation-emission matrix data array was obtained by concatenating excitation-emission matrices of the calibration set, validation set, and commercial tablet samples. The excitation-emission matrix data array was used to get parallel factor analysis, Tucker3, three-way partial least squares and unfolded partial least squares calibrations and to predict the amounts of valsartan and amlodipine besylate in samples. For all the methods, calibration and prediction of valsartan and amlodipine besylate were performed in the working concentration ranges of 0.25-4.50 μg/mL. The validity and the performance of all the proposed methods were checked by using the validation parameters. From the analysis results, it was concluded that the described two-way and three-way algorithmic methods were very useful for the simultaneous quantitative resolution and routine analysis of the related drug substances in marketed samples.

Least Median of Squares Filtering of Locally Optimal Point Matches for Compressible Flow Image Registration

PubMed Central

Castillo, Edward; Castillo, Richard; White, Benjamin; Rojo, Javier; Guerrero, Thomas

2012-01-01

Compressible flow based image registration operates under the assumption that the mass of the imaged material is conserved from one image to the next. Depending on how the mass conservation assumption is modeled, the performance of existing compressible flow methods is limited by factors such as image quality, noise, large magnitude voxel displacements, and computational requirements. The Least Median of Squares Filtered Compressible Flow (LFC) method introduced here is based on a localized, nonlinear least squares, compressible flow model that describes the displacement of a single voxel that lends itself to a simple grid search (block matching) optimization strategy. Spatially inaccurate grid search point matches, corresponding to erroneous local minimizers of the nonlinear compressible flow model, are removed by a novel filtering approach based on least median of squares fitting and the forward search outlier detection method. The spatial accuracy of the method is measured using ten thoracic CT image sets and large samples of expert determined landmarks (available at www.dir-lab.com). The LFC method produces an average error within the intra-observer error on eight of the ten cases, indicating that the method is capable of achieving a high spatial accuracy for thoracic CT registration. PMID:22797602

A simplified fractional order impedance model and parameter identification method for lithium-ion batteries

PubMed Central

Yang, Qingxia; Xu, Jun; Cao, Binggang; Li, Xiuqing

2017-01-01

Identification of internal parameters of lithium-ion batteries is a useful tool to evaluate battery performance, and requires an effective model and algorithm. Based on the least square genetic algorithm, a simplified fractional order impedance model for lithium-ion batteries and the corresponding parameter identification method were developed. The simplified model was derived from the analysis of the electrochemical impedance spectroscopy data and the transient response of lithium-ion batteries with different states of charge. In order to identify the parameters of the model, an equivalent tracking system was established, and the method of least square genetic algorithm was applied using the time-domain test data. Experiments and computer simulations were carried out to verify the effectiveness and accuracy of the proposed model and parameter identification method. Compared with a second-order resistance-capacitance (2-RC) model and recursive least squares method, small tracing voltage fluctuations were observed. The maximum battery voltage tracing error for the proposed model and parameter identification method is within 0.5%; this demonstrates the good performance of the model and the efficiency of the least square genetic algorithm to estimate the internal parameters of lithium-ion batteries. PMID:28212405

Calibration aspects of the JEM-EUSO mission

NASA Astrophysics Data System (ADS)

Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

2015-11-01

The JEM-EUSO telescope will be, after calibration, a very accurate instrument which yields the number of received photons from the number of measured photo-electrons. The project is in phase A (demonstration of the concept) including already operating prototype instruments, i.e. many parts of the instrument have been constructed and tested. Calibration is a crucial part of the instrument and its use. The focal surface (FS) of the JEM-EUSO telescope will consist of about 5000 photo-multiplier tubes (PMTs), which have to be well calibrated to reach the required accuracy in reconstructing the air-shower parameters. The optics system consists of 3 plastic Fresnel (double-sided) lenses of 2.5 m diameter. The aim of the calibration system is to measure the efficiencies (transmittances) of the optics and absolute efficiencies of the entire focal surface detector. The system consists of 3 main components: (i) Pre-flight calibration devices on ground, where the efficiency and gain of the PMTs will be measured absolutely and also the transmittance of the optics will be. (ii) On-board relative calibration system applying two methods: a) operating during the day when the JEM-EUSO lid will be closed with small light sources on board. b) operating during the night, together with data taking: the monitoring of the background rate over identical sites. (iii) Absolute in-flight calibration, again, applying two methods: a) measurement of the moon light, reflected on high altitude, high albedo clouds. b) measurements of calibrated flashes and tracks produced by the Global Light System (GLS). Some details of each calibration method will be described in this paper.

Evaluation of the Bitterness of Traditional Chinese Medicines using an E-Tongue Coupled with a Robust Partial Least Squares Regression Method.

PubMed

Lin, Zhaozhou; Zhang, Qiao; Liu, Ruixin; Gao, Xiaojie; Zhang, Lu; Kang, Bingya; Shi, Junhan; Wu, Zidan; Gui, Xinjing; Li, Xuelin

2016-01-25

To accurately, safely, and efficiently evaluate the bitterness of Traditional Chinese Medicines (TCMs), a robust predictor was developed using robust partial least squares (RPLS) regression method based on data obtained from an electronic tongue (e-tongue) system. The data quality was verified by the Grubb's test. Moreover, potential outliers were detected based on both the standardized residual and score distance calculated for each sample. The performance of RPLS on the dataset before and after outlier detection was compared to other state-of-the-art methods including multivariate linear regression, least squares support vector machine, and the plain partial least squares regression. Both R² and root-mean-squares error (RMSE) of cross-validation (CV) were recorded for each model. With four latent variables, a robust RMSECV value of 0.3916 with bitterness values ranging from 0.63 to 4.78 were obtained for the RPLS model that was constructed based on the dataset including outliers. Meanwhile, the RMSECV, which was calculated using the models constructed by other methods, was larger than that of the RPLS model. After six outliers were excluded, the performance of all benchmark methods markedly improved, but the difference between the RPLS model constructed before and after outlier exclusion was negligible. In conclusion, the bitterness of TCM decoctions can be accurately evaluated with the RPLS model constructed using e-tongue data.

Quantized kernel least mean square algorithm.

PubMed

Chen, Badong; Zhao, Songlin; Zhu, Pingping; Príncipe, José C

2012-01-01

In this paper, we propose a quantization approach, as an alternative of sparsification, to curb the growth of the radial basis function structure in kernel adaptive filtering. The basic idea behind this method is to quantize and hence compress the input (or feature) space. Different from sparsification, the new approach uses the "redundant" data to update the coefficient of the closest center. In particular, a quantized kernel least mean square (QKLMS) algorithm is developed, which is based on a simple online vector quantization method. The analytical study of the mean square convergence has been carried out. The energy conservation relation for QKLMS is established, and on this basis we arrive at a sufficient condition for mean square convergence, and a lower and upper bound on the theoretical value of the steady-state excess mean square error. Static function estimation and short-term chaotic time-series prediction examples are presented to demonstrate the excellent performance.

Speckle noise removal applied to ultrasound image of carotid artery based on total least squares model.

PubMed

Yang, Lei; Lu, Jun; Dai, Ming; Ren, Li-Jie; Liu, Wei-Zong; Li, Zhen-Zhou; Gong, Xue-Hao

2016-10-06

An ultrasonic image speckle noise removal method by using total least squares model is proposed and applied onto images of cardiovascular structures such as the carotid artery. On the basis of the least squares principle, the related principle of minimum square method is applied to cardiac ultrasound image speckle noise removal process to establish the model of total least squares, orthogonal projection transformation processing is utilized for the output of the model, and the denoising processing for the cardiac ultrasound image speckle noise is realized. Experimental results show that the improved algorithm can greatly improve the resolution of the image, and meet the needs of clinical medical diagnosis and treatment of the cardiovascular system for the head and neck. Furthermore, the success in imaging of carotid arteries has strong implications in neurological complications such as stroke.

Two Enhancements of the Logarithmic Least-Squares Method for Analyzing Subjective Comparisons

DTIC Science & Technology

1989-03-25

error term. 1 For this model, the total sum of squares ( SSTO ), defined as n 2 SSTO = E (yi y) i=1 can be partitioned into error and regression sums...of the regression line around the mean value. Mathematically, for the model given by equation A.4, SSTO = SSE + SSR (A.6) A-4 where SSTO is the total...sum of squares (i.e., the variance of the yi’s), SSE is error sum of squares, and SSR is the regression sum of squares. SSTO , SSE, and SSR are given

On the method of least squares. II. [for calculation of covariance matrices and optimization algorithms

NASA Technical Reports Server (NTRS)

Jefferys, W. H.

1981-01-01

A least squares method proposed previously for solving a general class of problems is expanded in two ways. First, covariance matrices related to the solution are calculated and their interpretation is given. Second, improved methods of solving the normal equations related to those of Marquardt (1963) and Fletcher and Powell (1963) are developed for this approach. These methods may converge in cases where Newton's method diverges or converges slowly.

Multiplier less high-speed squaring circuit for binary numbers

NASA Astrophysics Data System (ADS)

Sethi, Kabiraj; Panda, Rutuparna

2015-03-01

The squaring operation is important in many applications in signal processing, cryptography etc. In general, squaring circuits reported in the literature use fast multipliers. A novel idea of a squaring circuit without using multipliers is proposed in this paper. Ancient Indian method used for squaring decimal numbers is extended here for binary numbers. The key to our success is that no multiplier is used. Instead, one squaring circuit is used. The hardware architecture of the proposed squaring circuit is presented. The design is coded in VHDL and synthesised and simulated in Xilinx ISE Design Suite 10.1 (Xilinx Inc., San Jose, CA, USA). It is implemented in Xilinx Vertex 4vls15sf363-12 device (Xilinx Inc.). The results in terms of time delay and area is compared with both modified Booth's algorithm and squaring circuit using Vedic multipliers. Our proposed squaring circuit seems to have better performance in terms of both speed and area.

DIFFERENTIATION OF AURANTII FRUCTUS IMMATURUS AND FRUCTUS PONICIRI TRIFOLIATAE IMMATURUS BY FLOW-INJECTION WITH ULTRAVIOLET SPECTROSCOPIC DETECTION AND PROTON NUCLEAR MAGNETIC RESONANCE USING PARTIAL LEAST-SQUARES DISCRIMINANT ANALYSIS.

PubMed

Zhang, Mengliang; Zhao, Yang; Harrington, Peter de B; Chen, Pei

2016-03-01

Two simple fingerprinting methods, flow-injection coupled to ultraviolet spectroscopy and proton nuclear magnetic resonance, were used for discriminating between Aurantii fructus immaturus and Fructus poniciri trifoliatae immaturus . Both methods were combined with partial least-squares discriminant analysis. In the flow-injection method, four data representations were evaluated: total ultraviolet absorbance chromatograms, averaged ultraviolet spectra, absorbance at 193, 205, 225, and 283 nm, and absorbance at 225 and 283 nm. Prediction rates of 100% were achieved for all data representations by partial least-squares discriminant analysis using leave-one-sample-out cross-validation. The prediction rate for the proton nuclear magnetic resonance data by partial least-squares discriminant analysis with leave-one-sample-out cross-validation was also 100%. A new validation set of data was collected by flow-injection with ultraviolet spectroscopic detection two weeks later and predicted by partial least-squares discriminant analysis models constructed by the initial data representations with no parameter changes. The classification rates were 95% with the total ultraviolet absorbance chromatograms datasets and 100% with the other three datasets. Flow-injection with ultraviolet detection and proton nuclear magnetic resonance are simple, high throughput, and low-cost methods for discrimination studies.

An analytical method to calculate equivalent fields to irregular symmetric and asymmetric photon fields.

PubMed

Tahmasebi Birgani, Mohamad J; Chegeni, Nahid; Zabihzadeh, Mansoor; Hamzian, Nima

2014-01-01

Equivalent field is frequently used for central axis depth-dose calculations of rectangular- and irregular-shaped photon beams. As most of the proposed models to calculate the equivalent square field are dosimetry based, a simple physical-based method to calculate the equivalent square field size was used as the basis of this study. The table of the sides of the equivalent square or rectangular fields was constructed and then compared with the well-known tables by BJR and Venselaar, et al. with the average relative error percentage of 2.5 ± 2.5% and 1.5 ± 1.5%, respectively. To evaluate the accuracy of this method, the percentage depth doses (PDDs) were measured for some special irregular symmetric and asymmetric treatment fields and their equivalent squares for Siemens Primus Plus linear accelerator for both energies, 6 and 18MV. The mean relative differences of PDDs measurement for these fields and their equivalent square was approximately 1% or less. As a result, this method can be employed to calculate equivalent field not only for rectangular fields but also for any irregular symmetric or asymmetric field. © 2013 American Association of Medical Dosimetrists Published by American Association of Medical Dosimetrists All rights reserved.

A Comparison of Normal and Elliptical Estimation Methods in Structural Equation Models.

ERIC Educational Resources Information Center

Schumacker, Randall E.; Cheevatanarak, Suchittra

Monte Carlo simulation compared chi-square statistics, parameter estimates, and root mean square error of approximation values using normal and elliptical estimation methods. Three research conditions were imposed on the simulated data: sample size, population contamination percent, and kurtosis. A Bentler-Weeks structural model established the…

2-D weighted least-squares phase unwrapping

DOEpatents

Ghiglia, Dennis C.; Romero, Louis A.

1995-01-01

Weighted values of interferometric signals are unwrapped by determining the least squares solution of phase unwrapping for unweighted values of the interferometric signals; and then determining the least squares solution of phase unwrapping for weighted values of the interferometric signals by preconditioned conjugate gradient methods using the unweighted solutions as preconditioning values. An output is provided that is representative of the least squares solution of phase unwrapping for weighted values of the interferometric signals.

2-D weighted least-squares phase unwrapping

DOEpatents

Ghiglia, D.C.; Romero, L.A.

1995-06-13

Weighted values of interferometric signals are unwrapped by determining the least squares solution of phase unwrapping for unweighted values of the interferometric signals; and then determining the least squares solution of phase unwrapping for weighted values of the interferometric signals by preconditioned conjugate gradient methods using the unweighted solutions as preconditioning values. An output is provided that is representative of the least squares solution of phase unwrapping for weighted values of the interferometric signals. 6 figs.

A weak Galerkin least-squares finite element method for div-curl systems

NASA Astrophysics Data System (ADS)

Li, Jichun; Ye, Xiu; Zhang, Shangyou

2018-06-01

In this paper, we introduce a weak Galerkin least-squares method for solving div-curl problem. This finite element method leads to a symmetric positive definite system and has the flexibility to work with general meshes such as hybrid mesh, polytopal mesh and mesh with hanging nodes. Error estimates of the finite element solution are derived. The numerical examples demonstrate the robustness and flexibility of the proposed method.

Kernel Partial Least Squares for Nonlinear Regression and Discrimination

NASA Technical Reports Server (NTRS)

Rosipal, Roman; Clancy, Daniel (Technical Monitor)

2002-01-01

This paper summarizes recent results on applying the method of partial least squares (PLS) in a reproducing kernel Hilbert space (RKHS). A previously proposed kernel PLS regression model was proven to be competitive with other regularized regression methods in RKHS. The family of nonlinear kernel-based PLS models is extended by considering the kernel PLS method for discrimination. Theoretical and experimental results on a two-class discrimination problem indicate usefulness of the method.

Calibration and compensation method of three-axis geomagnetic sensor based on pre-processing total least square iteration

NASA Astrophysics Data System (ADS)

Zhou, Y.; Zhang, X.; Xiao, W.

2018-04-01

As the geomagnetic sensor is susceptible to interference, a pre-processing total least square iteration method is proposed for calibration compensation. Firstly, the error model of the geomagnetic sensor is analyzed and the correction model is proposed, then the characteristics of the model are analyzed and converted into nine parameters. The geomagnetic data is processed by Hilbert transform (HHT) to improve the signal-to-noise ratio, and the nine parameters are calculated by using the combination of Newton iteration method and the least squares estimation method. The sifter algorithm is used to filter the initial value of the iteration to ensure that the initial error is as small as possible. The experimental results show that this method does not need additional equipment and devices, can continuously update the calibration parameters, and better than the two-step estimation method, it can compensate geomagnetic sensor error well.

Solution of a few nonlinear problems in aerodynamics by the finite elements and functional least squares methods. Ph.D. Thesis - Paris Univ.; [mathematical models of transonic flow using nonlinear equations

NASA Technical Reports Server (NTRS)

Periaux, J.

1979-01-01

The numerical simulation of the transonic flows of idealized fluids and of incompressible viscous fluids, by the nonlinear least squares methods is presented. The nonlinear equations, the boundary conditions, and the various constraints controlling the two types of flow are described. The standard iterative methods for solving a quasi elliptical nonlinear equation with partial derivatives are reviewed with emphasis placed on two examples: the fixed point method applied to the Gelder functional in the case of compressible subsonic flows and the Newton method used in the technique of decomposition of the lifting potential. The new abstract least squares method is discussed. It consists of substituting the nonlinear equation by a problem of minimization in a H to the minus 1 type Sobolev functional space.

Use of inequality constrained least squares estimation in small area estimation

NASA Astrophysics Data System (ADS)

Abeygunawardana, R. A. B.; Wickremasinghe, W. N.

2017-05-01

Traditional surveys provide estimates that are based only on the sample observations collected for the population characteristic of interest. However, these estimates may have unacceptably large variance for certain domains. Small Area Estimation (SAE) deals with determining precise and accurate estimates for population characteristics of interest for such domains. SAE usually uses least squares or maximum likelihood procedures incorporating prior information and current survey data. Many available methods in SAE use constraints in equality form. However there are practical situations where certain inequality restrictions on model parameters are more realistic. It will lead to Inequality Constrained Least Squares (ICLS) estimates if the method used is least squares. In this study ICLS estimation procedure is applied to many proposed small area estimates.

Inter-class sparsity based discriminative least square regression.

PubMed

Wen, Jie; Xu, Yong; Li, Zuoyong; Ma, Zhongli; Xu, Yuanrong

2018-06-01

Least square regression is a very popular supervised classification method. However, two main issues greatly limit its performance. The first one is that it only focuses on fitting the input features to the corresponding output labels while ignoring the correlations among samples. The second one is that the used label matrix, i.e., zero-one label matrix is inappropriate for classification. To solve these problems and improve the performance, this paper presents a novel method, i.e., inter-class sparsity based discriminative least square regression (ICS_DLSR), for multi-class classification. Different from other methods, the proposed method pursues that the transformed samples have a common sparsity structure in each class. For this goal, an inter-class sparsity constraint is introduced to the least square regression model such that the margins of samples from the same class can be greatly reduced while those of samples from different classes can be enlarged. In addition, an error term with row-sparsity constraint is introduced to relax the strict zero-one label matrix, which allows the method to be more flexible in learning the discriminative transformation matrix. These factors encourage the method to learn a more compact and discriminative transformation for regression and thus has the potential to perform better than other methods. Extensive experimental results show that the proposed method achieves the best performance in comparison with other methods for multi-class classification. Copyright © 2018 Elsevier Ltd. All rights reserved.

Examinations of electron temperature calculation methods in Thomson scattering diagnostics.

PubMed

Oh, Seungtae; Lee, Jong Ha; Wi, Hanmin

2012-10-01

Electron temperature from Thomson scattering diagnostic is derived through indirect calculation based on theoretical model. χ-square test is commonly used in the calculation, and the reliability of the calculation method highly depends on the noise level of input signals. In the simulations, noise effects of the χ-square test are examined and scale factor test is proposed as an alternative method.

Sampling strategies for square and boll-feeding plant bugs (Hemiptera: Miridae) occurring on cotton

USDA-ARS?s Scientific Manuscript database

Six sampling methods targeting square and boll-feeding plant bugs on cotton were compared during three cotton growth periods (early-season squaring, early bloom, and peak through late bloom) by samplers differing in experience (with prior years of sampling experience or no experience) along the coas...

Assessing Fit and Dimensionality in Least Squares Metric Multidimensional Scaling Using Akaike's Information Criterion

ERIC Educational Resources Information Center

Ding, Cody S.; Davison, Mark L.

2010-01-01

Akaike's information criterion is suggested as a tool for evaluating fit and dimensionality in metric multidimensional scaling that uses least squares methods of estimation. This criterion combines the least squares loss function with the number of estimated parameters. Numerical examples are presented. The results from analyses of both simulation…

An Alternating Least Squares Method for the Weighted Approximation of a Symmetric Matrix.

ERIC Educational Resources Information Center

ten Berge, Jos M. F.; Kiers, Henk A. L.

1993-01-01

R. A. Bailey and J. C. Gower explored approximating a symmetric matrix "B" by another, "C," in the least squares sense when the squared discrepancies for diagonal elements receive specific nonunit weights. A solution is proposed where "C" is constrained to be positive semidefinite and of a fixed rank. (SLD)

Spatiotemporal groundwater level modeling using hybrid artificial intelligence-meshless method

NASA Astrophysics Data System (ADS)

Nourani, Vahid; Mousavi, Shahram

2016-05-01

Uncertainties of the field parameters, noise of the observed data and unknown boundary conditions are the main factors involved in the groundwater level (GL) time series which limit the modeling and simulation of GL. This paper presents a hybrid artificial intelligence-meshless model for spatiotemporal GL modeling. In this way firstly time series of GL observed in different piezometers were de-noised using threshold-based wavelet method and the impact of de-noised and noisy data was compared in temporal GL modeling by artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). In the second step, both ANN and ANFIS models were calibrated and verified using GL data of each piezometer, rainfall and runoff considering various input scenarios to predict the GL at one month ahead. In the final step, the simulated GLs in the second step of modeling were considered as interior conditions for the multiquadric radial basis function (RBF) based solve of governing partial differential equation of groundwater flow to estimate GL at any desired point within the plain where there is not any observation. In order to evaluate and compare the GL pattern at different time scales, the cross-wavelet coherence was also applied to GL time series of piezometers. The results showed that the threshold-based wavelet de-noising approach can enhance the performance of the modeling up to 13.4%. Also it was found that the accuracy of ANFIS-RBF model is more reliable than ANN-RBF model in both calibration and validation steps.

Hybrid least squares multivariate spectral analysis methods

DOEpatents

Haaland, David M.

2002-01-01

A set of hybrid least squares multivariate spectral analysis methods in which spectral shapes of components or effects not present in the original calibration step are added in a following estimation or calibration step to improve the accuracy of the estimation of the amount of the original components in the sampled mixture. The "hybrid" method herein means a combination of an initial classical least squares analysis calibration step with subsequent analysis by an inverse multivariate analysis method. A "spectral shape" herein means normally the spectral shape of a non-calibrated chemical component in the sample mixture but can also mean the spectral shapes of other sources of spectral variation, including temperature drift, shifts between spectrometers, spectrometer drift, etc. The "shape" can be continuous, discontinuous, or even discrete points illustrative of the particular effect.

Parametric output-only identification of time-varying structures using a kernel recursive extended least squares TARMA approach

NASA Astrophysics Data System (ADS)

Ma, Zhi-Sai; Liu, Li; Zhou, Si-Da; Yu, Lei; Naets, Frank; Heylen, Ward; Desmet, Wim

2018-01-01

The problem of parametric output-only identification of time-varying structures in a recursive manner is considered. A kernelized time-dependent autoregressive moving average (TARMA) model is proposed by expanding the time-varying model parameters onto the basis set of kernel functions in a reproducing kernel Hilbert space. An exponentially weighted kernel recursive extended least squares TARMA identification scheme is proposed, and a sliding-window technique is subsequently applied to fix the computational complexity for each consecutive update, allowing the method to operate online in time-varying environments. The proposed sliding-window exponentially weighted kernel recursive extended least squares TARMA method is employed for the identification of a laboratory time-varying structure consisting of a simply supported beam and a moving mass sliding on it. The proposed method is comparatively assessed against an existing recursive pseudo-linear regression TARMA method via Monte Carlo experiments and shown to be capable of accurately tracking the time-varying dynamics. Furthermore, the comparisons demonstrate the superior achievable accuracy, lower computational complexity and enhanced online identification capability of the proposed kernel recursive extended least squares TARMA approach.

A New Global Regression Analysis Method for the Prediction of Wind Tunnel Model Weight Corrections

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert Manfred; Bridge, Thomas M.; Amaya, Max A.

2014-01-01

A new global regression analysis method is discussed that predicts wind tunnel model weight corrections for strain-gage balance loads during a wind tunnel test. The method determines corrections by combining "wind-on" model attitude measurements with least squares estimates of the model weight and center of gravity coordinates that are obtained from "wind-off" data points. The method treats the least squares fit of the model weight separate from the fit of the center of gravity coordinates. Therefore, it performs two fits of "wind- off" data points and uses the least squares estimator of the model weight as an input for the fit of the center of gravity coordinates. Explicit equations for the least squares estimators of the weight and center of gravity coordinates are derived that simplify the implementation of the method in the data system software of a wind tunnel. In addition, recommendations for sets of "wind-off" data points are made that take typical model support system constraints into account. Explicit equations of the confidence intervals on the model weight and center of gravity coordinates and two different error analyses of the model weight prediction are also discussed in the appendices of the paper.

Tracing the conformational changes in BSA using FRET with environmentally-sensitive squaraine probes

NASA Astrophysics Data System (ADS)

Govor, Iryna V.; Tatarets, Anatoliy L.; Obukhova, Olena M.; Terpetschnig, Ewald A.; Gellerman, Gary; Patsenker, Leonid D.

2016-06-01

A new potential method of detecting the conformational changes in hydrophobic proteins such as bovine serum albumin (BSA) is introduced. The method is based on the change in the Förster resonance energy transfer (FRET) efficiency between protein-sensitive fluorescent probes. As compared to conventional FRET based methods, in this new approach the donor and acceptor dyes are not covalently linked to protein molecules. Performance of the new method is demonstrated using the protein-sensitive squaraine probes Square-634 (donor) and Square-685 (acceptor) to detect the urea-induced conformational changes of BSA. The FRET efficiency between these probes can be considered a more sensitive parameter to trace protein unfolding as compared to the changes in fluorescence intensity of each of these probes. Addition of urea followed by BSA unfolding causes a noticeable decrease in the emission intensities of these probes (factor of 5.6 for Square-634 and 3.0 for Square-685), and the FRET efficiency changes by a factor of up to 17. Compared to the conventional method the new approach therefore demonstrates to be a more sensitive way to detect the conformational changes in BSA.

Assessment of Gait Characteristics in Total Knee Arthroplasty Patients Using a Hierarchical Partial Least Squares Method.

PubMed

Wang, Wei; Ackland, David C; McClelland, Jodie A; Webster, Kate E; Halgamuge, Saman

2018-01-01

Quantitative gait analysis is an important tool in objective assessment and management of total knee arthroplasty (TKA) patients. Studies evaluating gait patterns in TKA patients have tended to focus on discrete data such as spatiotemporal information, joint range of motion and peak values of kinematics and kinetics, or consider selected principal components of gait waveforms for analysis. These strategies may not have the capacity to capture small variations in gait patterns associated with each joint across an entire gait cycle, and may ultimately limit the accuracy of gait classification. The aim of this study was to develop an automatic feature extraction method to analyse patterns from high-dimensional autocorrelated gait waveforms. A general linear feature extraction framework was proposed and a hierarchical partial least squares method derived for discriminant analysis of multiple gait waveforms. The effectiveness of this strategy was verified using a dataset of joint angle and ground reaction force waveforms from 43 patients after TKA surgery and 31 healthy control subjects. Compared with principal component analysis and partial least squares methods, the hierarchical partial least squares method achieved generally better classification performance on all possible combinations of waveforms, with the highest classification accuracy . The novel hierarchical partial least squares method proposed is capable of capturing virtually all significant differences between TKA patients and the controls, and provides new insights into data visualization. The proposed framework presents a foundation for more rigorous classification of gait, and may ultimately be used to evaluate the effects of interventions such as surgery and rehabilitation.

Evaluation of the Bitterness of Traditional Chinese Medicines using an E-Tongue Coupled with a Robust Partial Least Squares Regression Method

PubMed Central

Lin, Zhaozhou; Zhang, Qiao; Liu, Ruixin; Gao, Xiaojie; Zhang, Lu; Kang, Bingya; Shi, Junhan; Wu, Zidan; Gui, Xinjing; Li, Xuelin

2016-01-01

To accurately, safely, and efficiently evaluate the bitterness of Traditional Chinese Medicines (TCMs), a robust predictor was developed using robust partial least squares (RPLS) regression method based on data obtained from an electronic tongue (e-tongue) system. The data quality was verified by the Grubb’s test. Moreover, potential outliers were detected based on both the standardized residual and score distance calculated for each sample. The performance of RPLS on the dataset before and after outlier detection was compared to other state-of-the-art methods including multivariate linear regression, least squares support vector machine, and the plain partial least squares regression. Both R2 and root-mean-squares error (RMSE) of cross-validation (CV) were recorded for each model. With four latent variables, a robust RMSECV value of 0.3916 with bitterness values ranging from 0.63 to 4.78 were obtained for the RPLS model that was constructed based on the dataset including outliers. Meanwhile, the RMSECV, which was calculated using the models constructed by other methods, was larger than that of the RPLS model. After six outliers were excluded, the performance of all benchmark methods markedly improved, but the difference between the RPLS model constructed before and after outlier exclusion was negligible. In conclusion, the bitterness of TCM decoctions can be accurately evaluated with the RPLS model constructed using e-tongue data. PMID:26821026

Solution of a Complex Least Squares Problem with Constrained Phase.

PubMed

Bydder, Mark

2010-12-30

The least squares solution of a complex linear equation is in general a complex vector with independent real and imaginary parts. In certain applications in magnetic resonance imaging, a solution is desired such that each element has the same phase. A direct method for obtaining the least squares solution to the phase constrained problem is described.

Three-dimensional convection of binary mixtures in porous media.

PubMed

Umla, R; Augustin, M; Huke, B; Lücke, M

2011-11-01

We investigate convection patterns of binary mixtures with a positive separation ratio in porous media. As setup, we choose the Rayleigh-Bénard system of a fluid layer heated from below. Results are obtained by a multimode Galerkin method. Using this method, we compute square and crossroll patterns, and we analyze their structural, bifurcation, and stability properties. Evidence is provided that, for a strong enough Soret effect, both structures exist as stable forms of convection. Some of their properties are found to be similar to square and crossroll convection in the system without porous medium. However, there are also qualitative differences. For example, squares can be destabilized by oscillatory perturbations with square symmetry in porous media, and their velocity isolines are deformed in the so-called Soret regime.

Reference Ranges of Left Ventricular Strain Measures by Two-Dimensional Speckle-Tracking Echocardiography in Children: A Systematic Review and Meta-Analysis.

PubMed

Levy, Philip T; Machefsky, Aliza; Sanchez, Aura A; Patel, Meghna D; Rogal, Sarah; Fowler, Susan; Yaeger, Lauren; Hardi, Angela; Holland, Mark R; Hamvas, Aaron; Singh, Gautam K

2016-03-01

Establishment of the range of reference values and associated variations of two-dimensional speckle-tracking echocardiography (2DSTE)-derived left ventricular (LV) strain is a prerequisite for its routine clinical adoption in pediatrics. The aims of this study were to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) measurements derived by 2DSTE in children and to identify confounding factors that may contribute to variance in reported measures. A systematic review was launched in MEDLINE, Embase, Scopus, the Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library. Search hedges were created to cover the concepts of pediatrics, STE, and left-heart ventricle. Two investigators independently identified and included studies if they reported 2DSTE-derived LV GLS, GCS, or GRS. The weighted mean was estimated by using random effects models with 95% CIs, heterogeneity was assessed using the Cochran Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using the Egger test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression. The search identified 2,325 children from 43 data sets. The reported normal mean values of GLS among the studies varied from -16.7% to -23.6% (mean, -20.2%; 95% CI, -19.5% to -20.8%), GCS varied from -12.9% to -31.4% (mean, -22.3%; 95% CI, -19.9% to -24.6%), and GRS varied from 33.9% to 54.5% (mean, 45.2%; 95% CI, 38.3% to 51.7%). Twenty-six studies reported longitudinal strain only from the apical four-chamber view, with a mean of -20.4% (95% CI, -19.8% to -21.7%). Twenty-three studies reported circumferential strain (mean, -20.3%; 95% CI, -19.4% to -21.2%) and radial strain (mean, 46.7%; 95% CI, 42.3% to 51.1%) from the short-axis view at the midventricular level. A significant apex-to-base segmental longitudinal strain gradient (P < .01) was observed in the LV free wall. There was significant between-study heterogeneity and inconsistency (I(2) > 94% and P < .001 for each strain measure), which was not explained by age, gender, body surface area, blood pressure, heart rate, frame rate, frame rate/heart rate ratio, tissue-tracking methodology, location of reported strain value along the strain curve, ultrasound equipment, or software. The metaregression showed that these effects were not significant determinants of variations among normal ranges of strain values. There was no evidence of publication bias (P = .40). This study defines reference values of 2DSTE-derived LV strain in children on the basis of a meta-analysis. In healthy children, mean LV GLS was -20.2% (95% CI, -19.5% to -20.8%), mean GCS was -22.3% (95% CI, -19.9% to -24.6%), and mean GRS was 45.2% (95% CI, 38.3% to 51.7%). LV segmental longitudinal strain has a stable apex-to-base gradient that is preserved throughout maturation. Although variations among different reference ranges in this meta-analysis were not dependent on differences in demographic, clinical, or vendor parameters, age- and vendor-specific referenced ranges were established as well. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Orthogonalizing EM: A design-based least squares algorithm.

PubMed

Xiong, Shifeng; Dai, Bin; Huling, Jared; Qian, Peter Z G

We introduce an efficient iterative algorithm, intended for various least squares problems, based on a design of experiments perspective. The algorithm, called orthogonalizing EM (OEM), works for ordinary least squares and can be easily extended to penalized least squares. The main idea of the procedure is to orthogonalize a design matrix by adding new rows and then solve the original problem by embedding the augmented design in a missing data framework. We establish several attractive theoretical properties concerning OEM. For the ordinary least squares with a singular regression matrix, an OEM sequence converges to the Moore-Penrose generalized inverse-based least squares estimator. For ordinary and penalized least squares with various penalties, it converges to a point having grouping coherence for fully aliased regression matrices. Convergence and the convergence rate of the algorithm are examined. Finally, we demonstrate that OEM is highly efficient for large-scale least squares and penalized least squares problems, and is considerably faster than competing methods when n is much larger than p . Supplementary materials for this article are available online.

Infant perception of the rotating Kanizsa square.

PubMed

Yoshino, Daisuke; Idesawa, Masanori; Kanazawa, So; Yamaguchi, Masami K

2010-04-01

This study examined the perception of the rotating Kanizsa square by using a fixed-trial familiarization method. If the Kanizsa square is rotated across the pacmen, adult observers perceive not only a rotating illusory square, but also an illusory expansion/contraction motion of this square. The phenomenon is called a "rotational dynamic illusion". In experiments 1 and 2, we investigated whether infants perceived the rotational dynamic illusion, finding that 3-8-month-old infants perceived the rotational dynamic illusion as a simple rotation of the Kanizsa square. In experiment 3, we investigated whether infants perceived the rotational dynamic illusion as a rotation of the Kanizsa square or as a deformation of shape, finding that 3-4-month-old infants did perceive the rotational dynamic illusion as a rotation of the Kanizsa square. Our results show that while 3-8-month-old infants perceive the rotating Kanizsa square, however, it is difficult for the infants to extract expansion/contraction motion from the rotational dynamic illusion. Copyright 2010 Elsevier Inc. All rights reserved.

Stability indicating methods for the analysis of cefprozil in the presence of its alkaline induced degradation product

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

2016-04-01

Three simple, specific, accurate and precise spectrophotometric methods were developed for the determination of cefprozil (CZ) in the presence of its alkaline induced degradation product (DCZ). The first method was the bivariate method, while the two other multivariate methods were partial least squares (PLS) and spectral residual augmented classical least squares (SRACLS). The multivariate methods were applied with and without variable selection procedure (genetic algorithm GA). These methods were tested by analyzing laboratory prepared mixtures of the above drug with its alkaline induced degradation product and they were applied to its commercial pharmaceutical products.

Photogrammetric Method and Software for Stream Planform Identification

NASA Astrophysics Data System (ADS)

Stonedahl, S. H.; Stonedahl, F.; Lohberg, M. M.; Lusk, K.; Miller, D.

2013-12-01

Accurately characterizing the planform of a stream is important for many purposes, including recording measurement and sampling locations, monitoring change due to erosion or volumetric discharge, and spatial modeling of stream processes. While expensive surveying equipment or high resolution aerial photography can be used to obtain planform data, our research focused on developing a close-range photogrammetric method (and accompanying free/open-source software) to serve as a cost-effective alternative. This method involves securing and floating a wooden square frame on the stream surface at several locations, taking photographs from numerous angles at each location, and then post-processing and merging data from these photos using the corners of the square for reference points, unit scale, and perspective correction. For our test field site we chose a ~35m reach along Black Hawk Creek in Sunderbruch Park (Davenport, IA), a small, slow-moving stream with overhanging trees. To quantify error we measured 88 distances between 30 marked control points along the reach. We calculated error by comparing these 'ground truth' distances to the corresponding distances extracted from our photogrammetric method. We placed the square at three locations along our reach and photographed it from multiple angles. The square corners, visible control points, and visible stream outline were hand-marked in these photos using the GIMP (open-source image editor). We wrote an open-source GUI in Java (hosted on GitHub), which allows the user to load marked-up photos, designate square corners and label control points. The GUI also extracts the marked pixel coordinates from the images. We also wrote several scripts (currently in MATLAB) that correct the pixel coordinates for radial distortion using Brown's lens distortion model, correct for perspective by forcing the four square corner pixels to form a parallelogram in 3-space, and rotate the points in order to correctly orient all photos of the same square location. Planform data from multiple photos (and multiple square locations) are combined using weighting functions that mitigate the error stemming from the markup-process, imperfect camera calibration, etc. We have used our (beta) software to mark and process over 100 photos, yielding an average error of only 1.5% relative to our 88 measured lengths. Next we plan to translate the MATLAB scripts into Python and release their source code, at which point only free software, consumer-grade digital cameras, and inexpensive building materials will be needed for others to replicate this method at new field sites. Three sample photographs of the square with the created planform and control points

Combinatorics of least-squares trees.

PubMed

Mihaescu, Radu; Pachter, Lior

2008-09-09

A recurring theme in the least-squares approach to phylogenetics has been the discovery of elegant combinatorial formulas for the least-squares estimates of edge lengths. These formulas have proved useful for the development of efficient algorithms, and have also been important for understanding connections among popular phylogeny algorithms. For example, the selection criterion of the neighbor-joining algorithm is now understood in terms of the combinatorial formulas of Pauplin for estimating tree length. We highlight a phylogenetically desirable property that weighted least-squares methods should satisfy, and provide a complete characterization of methods that satisfy the property. The necessary and sufficient condition is a multiplicative four-point condition that the variance matrix needs to satisfy. The proof is based on the observation that the Lagrange multipliers in the proof of the Gauss-Markov theorem are tree-additive. Our results generalize and complete previous work on ordinary least squares, balanced minimum evolution, and the taxon-weighted variance model. They also provide a time-optimal algorithm for computation.

A decentralized square root information filter/smoother

NASA Technical Reports Server (NTRS)

Bierman, G. J.; Belzer, M. R.

1985-01-01

A number of developments has recently led to a considerable interest in the decentralization of linear least squares estimators. The developments are partly related to the impending emergence of VLSI technology, the realization of parallel processing, and the need for algorithmic ways to speed the solution of dynamically decoupled, high dimensional estimation problems. A new method is presented for combining Square Root Information Filters (SRIF) estimates obtained from independent data sets. The new method involves an orthogonal transformation, and an information matrix filter 'homework' problem discussed by Schweppe (1973) is generalized. The employed SRIF orthogonal transformation methodology has been described by Bierman (1977).

Simulation of Foam Divot Weight on External Tank Utilizing Least Squares and Neural Network Methods

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Coroneos, Rula M.

2007-01-01

Simulation of divot weight in the insulating foam, associated with the external tank of the U.S. space shuttle, has been evaluated using least squares and neural network concepts. The simulation required models based on fundamental considerations that can be used to predict under what conditions voids form, the size of the voids, and subsequent divot ejection mechanisms. The quadratic neural networks were found to be satisfactory for the simulation of foam divot weight in various tests associated with the external tank. Both linear least squares method and the nonlinear neural network predicted identical results.

Theoretical study of the incompressible Navier-Stokes equations by the least-squares method

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Loh, Ching Y.; Povinelli, Louis A.

1994-01-01

Usually the theoretical analysis of the Navier-Stokes equations is conducted via the Galerkin method which leads to difficult saddle-point problems. This paper demonstrates that the least-squares method is a useful alternative tool for the theoretical study of partial differential equations since it leads to minimization problems which can often be treated by an elementary technique. The principal part of the Navier-Stokes equations in the first-order velocity-pressure-vorticity formulation consists of two div-curl systems, so the three-dimensional div-curl system is thoroughly studied at first. By introducing a dummy variable and by using the least-squares method, this paper shows that the div-curl system is properly determined and elliptic, and has a unique solution. The same technique then is employed to prove that the Stokes equations are properly determined and elliptic, and that four boundary conditions on a fixed boundary are required for three-dimensional problems. This paper also shows that under four combinations of non-standard boundary conditions the solution of the Stokes equations is unique. This paper emphasizes the application of the least-squares method and the div-curl method to derive a high-order version of differential equations and additional boundary conditions. In this paper, an elementary method (integration by parts) is used to prove Friedrichs' inequalities related to the div and curl operators which play an essential role in the analysis.

A new algorithm for stand table projection models.

Treesearch

Quang V. Cao; V. Clark Baldwin

1999-01-01

The constrained least squares method is proposed as an algorithm for projecting stand tables through time. This method consists of three steps: (1) predict survival in each diameter class, (2) predict diameter growth, and (3) use the least squares approach to adjust the stand table to satisfy the constraints of future survival, average diameter, and stand basal area....

Coupling finite element and spectral methods: First results

NASA Technical Reports Server (NTRS)

Bernardi, Christine; Debit, Naima; Maday, Yvon

1987-01-01

A Poisson equation on a rectangular domain is solved by coupling two methods: the domain is divided in two squares, a finite element approximation is used on the first square and a spectral discretization is used on the second one. Two kinds of matching conditions on the interface are presented and compared. In both cases, error estimates are proved.

The Least-Squares Estimation of Latent Trait Variables.

ERIC Educational Resources Information Center

Tatsuoka, Kikumi

This paper presents a new method for estimating a given latent trait variable by the least-squares approach. The beta weights are obtained recursively with the help of Fourier series and expressed as functions of item parameters of response curves. The values of the latent trait variable estimated by this method and by maximum likelihood method…

Discrimination of Aurantii Fructus Immaturus and Fructus Poniciri Trifoliatae Immaturus by Flow Injection UV Spectroscopy (FIUV) and 1H NMR using Partial Least-squares Discriminant Analysis (PLS-DA)

USDA-ARS?s Scientific Manuscript database

Two simple fingerprinting methods, flow-injection UV spectroscopy (FIUV) and 1H nuclear magnetic resonance (NMR), for discrimination of Aurantii FructusImmaturus and Fructus Poniciri TrifoliataeImmaturususing were described. Both methods were combined with partial least-squares discriminant analysis...

Evaluation of fatty proportion in fatty liver using least squares method with constraints.

PubMed

Li, Xingsong; Deng, Yinhui; Yu, Jinhua; Wang, Yuanyuan; Shamdasani, Vijay

2014-01-01

Backscatter and attenuation parameters are not easily measured in clinical applications due to tissue inhomogeneity in the region of interest (ROI). A least squares method(LSM) that fits the echo signal power spectra from a ROI to a 3-parameter tissue model was used to get attenuation coefficient imaging in fatty liver. Since fat's attenuation value is higher than normal liver parenchyma, a reasonable threshold was chosen to evaluate the fatty proportion in fatty liver. Experimental results using clinical data of fatty liver illustrate that the least squares method can get accurate attenuation estimates. It is proved that the attenuation values have a positive correlation with the fatty proportion, which can be used to evaluate the syndrome of fatty liver.

Note: A novel method for generating multichannel quasi-square-wave pulses.

PubMed

Mao, C; Zou, X; Wang, X

2015-08-01

A 21-channel quasi-square-wave nanosecond pulse generator was constructed. The generator consists of a high-voltage square-wave pulser and a channel divider. Using an electromagnetic relay as a switch and a 50-Ω polyethylene cable as a pulse forming line, the high-voltage pulser produces a 10-ns square-wave pulse of 1070 V. With a specially designed resistor-cable network, the channel divider divides the high-voltage square-wave pulse into 21 identical 10-ns quasi-square-wave pulses of 51 V, exactly equal to 1070 V/21. The generator can operate not only in a simultaneous mode but also in a delay mode if the cables in the channel divider are different in length.

Analysis of Lard in Lipstick Formulation Using FTIR Spectroscopy and Multivariate Calibration: A Comparison of Three Extraction Methods.

PubMed

Waskitho, Dri; Lukitaningsih, Endang; Sudjadi; Rohman, Abdul

2016-01-01

Analysis of lard extracted from lipstick formulation containing castor oil has been performed using FTIR spectroscopic method combined with multivariate calibration. Three different extraction methods were compared, namely saponification method followed by liquid/liquid extraction with hexane/dichlorometane/ethanol/water, saponification method followed by liquid/liquid extraction with dichloromethane/ethanol/water, and Bligh & Dyer method using chloroform/methanol/water as extracting solvent. Qualitative and quantitative analysis of lard were performed using principle component (PCA) and partial least square (PLS) analysis, respectively. The results showed that, in all samples prepared by the three extraction methods, PCA was capable of identifying lard at wavelength region of 1200-800 cm -1 with the best result was obtained by Bligh & Dyer method. Furthermore, PLS analysis at the same wavelength region used for qualification showed that Bligh and Dyer was the most suitable extraction method with the highest determination coefficient (R 2 ) and the lowest root mean square error of calibration (RMSEC) as well as root mean square error of prediction (RMSEP) values.

Forecasting Error Calculation with Mean Absolute Deviation and Mean Absolute Percentage Error

NASA Astrophysics Data System (ADS)

Khair, Ummul; Fahmi, Hasanul; Hakim, Sarudin Al; Rahim, Robbi

2017-12-01

Prediction using a forecasting method is one of the most important things for an organization, the selection of appropriate forecasting methods is also important but the percentage error of a method is more important in order for decision makers to adopt the right culture, the use of the Mean Absolute Deviation and Mean Absolute Percentage Error to calculate the percentage of mistakes in the least square method resulted in a percentage of 9.77% and it was decided that the least square method be worked for time series and trend data.

A least-squares finite element method for incompressible Navier-Stokes problems

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan

1992-01-01

A least-squares finite element method, based on the velocity-pressure-vorticity formulation, is developed for solving steady incompressible Navier-Stokes problems. This method leads to a minimization problem rather than to a saddle-point problem by the classic mixed method and can thus accommodate equal-order interpolations. This method has no parameter to tune. The associated algebraic system is symmetric, and positive definite. Numerical results for the cavity flow at Reynolds number up to 10,000 and the backward-facing step flow at Reynolds number up to 900 are presented.

Development of New Methods for Predicting the Bistatic Electromagnetic Scattering from Absorbing Shapes

DTIC Science & Technology

1990-01-01

least-squares sense by adding a penalty term proportional to the square of the divergence to the variational principle At the start of this project... principle required for stable solutions of the electromagnetic field: It must be possible to express the basis functions used in the finite element method as... principle to derive several different methods for computing stable solutions to electromagnetic field problems. To understand above principle , notice that

Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging.

PubMed

Nadeau, Kyle P; Rice, Tyler B; Durkin, Anthony J; Tromberg, Bruce J

2015-11-01

We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI.

Multifrequency synthesis and extraction using square wave projection patterns for quantitative tissue imaging

PubMed Central

Nadeau, Kyle P.; Rice, Tyler B.; Durkin, Anthony J.; Tromberg, Bruce J.

2015-01-01

Abstract. We present a method for spatial frequency domain data acquisition utilizing a multifrequency synthesis and extraction (MSE) method and binary square wave projection patterns. By illuminating a sample with square wave patterns, multiple spatial frequency components are simultaneously attenuated and can be extracted to determine optical property and depth information. Additionally, binary patterns are projected faster than sinusoids typically used in spatial frequency domain imaging (SFDI), allowing for short (millisecond or less) camera exposure times, and data acquisition speeds an order of magnitude or more greater than conventional SFDI. In cases where sensitivity to superficial layers or scattering is important, the fundamental component from higher frequency square wave patterns can be used. When probing deeper layers, the fundamental and harmonic components from lower frequency square wave patterns can be used. We compared optical property and depth penetration results extracted using square waves to those obtained using sinusoidal patterns on an in vivo human forearm and absorbing tube phantom, respectively. Absorption and reduced scattering coefficient values agree with conventional SFDI to within 1% using both high frequency (fundamental) and low frequency (fundamental and harmonic) spatial frequencies. Depth penetration reflectance values also agree to within 1% of conventional SFDI. PMID:26524682

Wind Tunnel Strain-Gage Balance Calibration Data Analysis Using a Weighted Least Squares Approach

NASA Technical Reports Server (NTRS)

Ulbrich, N.; Volden, T.

2017-01-01

A new approach is presented that uses a weighted least squares fit to analyze wind tunnel strain-gage balance calibration data. The weighted least squares fit is specifically designed to increase the influence of single-component loadings during the regression analysis. The weighted least squares fit also reduces the impact of calibration load schedule asymmetries on the predicted primary sensitivities of the balance gages. A weighting factor between zero and one is assigned to each calibration data point that depends on a simple count of its intentionally loaded load components or gages. The greater the number of a data point's intentionally loaded load components or gages is, the smaller its weighting factor becomes. The proposed approach is applicable to both the Iterative and Non-Iterative Methods that are used for the analysis of strain-gage balance calibration data in the aerospace testing community. The Iterative Method uses a reasonable estimate of the tare corrected load set as input for the determination of the weighting factors. The Non-Iterative Method, on the other hand, uses gage output differences relative to the natural zeros as input for the determination of the weighting factors. Machine calibration data of a six-component force balance is used to illustrate benefits of the proposed weighted least squares fit. In addition, a detailed derivation of the PRESS residuals associated with a weighted least squares fit is given in the appendices of the paper as this information could not be found in the literature. These PRESS residuals may be needed to evaluate the predictive capabilities of the final regression models that result from a weighted least squares fit of the balance calibration data.

How to deal with the high condition number of the noise covariance matrix of gravity field functionals synthesised from a satellite-only global gravity field model?

NASA Astrophysics Data System (ADS)

Klees, R.; Slobbe, D. C.; Farahani, H. H.

2018-03-01

The posed question arises for instance in regional gravity field modelling using weighted least-squares techniques if the gravity field functionals are synthesised from the spherical harmonic coefficients of a satellite-only global gravity model (GGM), and are used as one of the noisy datasets. The associated noise covariance matrix, appeared to be extremely ill-conditioned with a singular value spectrum that decayed gradually to zero without any noticeable gap. We analysed three methods to deal with the ill-conditioned noise covariance matrix: Tihonov regularisation of the noise covariance matrix in combination with the standard formula for the weighted least-squares estimator, a formula of the weighted least-squares estimator, which does not involve the inverse noise covariance matrix, and an estimator based on Rao's unified theory of least-squares. Our analysis was based on a numerical experiment involving a set of height anomalies synthesised from the GGM GOCO05s, which is provided with a full noise covariance matrix. We showed that the three estimators perform similar, provided that the two regularisation parameters each method knows were chosen properly. As standard regularisation parameter choice rules do not apply here, we suggested a new parameter choice rule, and demonstrated its performance. Using this rule, we found that the differences between the three least-squares estimates were within noise. For the standard formulation of the weighted least-squares estimator with regularised noise covariance matrix, this required an exceptionally strong regularisation, much larger than one expected from the condition number of the noise covariance matrix. The preferred method is the inversion-free formulation of the weighted least-squares estimator, because of its simplicity with respect to the choice of the two regularisation parameters.

Fabrication of long linear arrays of plastic optical fibers with squared ends for the use of code mark printing lithography

NASA Astrophysics Data System (ADS)

Horiuchi, Toshiyuki; Watanabe, Jun; Suzuki, Yuta; Iwasaki, Jun-ya

2017-05-01

Two dimensional code marks are often used for the production management. In particular, in the production lines of liquid-crystal-display panels and others, data on fabrication processes such as production number and process conditions are written on each substrate or device in detail, and they are used for quality managements. For this reason, lithography system specialized in code mark printing is developed. However, conventional systems using lamp projection exposure or laser scan exposure are very expensive. Therefore, development of a low-cost exposure system using light emitting diodes (LEDs) and optical fibers with squared ends arrayed in a matrix is strongly expected. In the past research, feasibility of such a new exposure system was demonstrated using a handmade system equipped with 100 LEDs with a central wavelength of 405 nm, a 10×10 matrix of optical fibers with 1 mm square ends, and a 10X projection lens. Based on these progresses, a new method for fabricating large-scale arrays of finer fibers with squared ends was developed in this paper. At most 40 plastic optical fibers were arranged in a linear gap of an arraying instrument, and simultaneously squared by heating them on a hotplate at 120°C for 7 min. Fiber sizes were homogeneous within 496+/-4 μm. In addition, average light leak was improved from 34.4 to 21.3% by adopting the new method in place of conventional one by one squaring method. Square matrix arrays necessary for printing code marks will be obtained by piling the newly fabricated linear arrays up.

Comparison of Peak-Flow Estimation Methods for Small Drainage Basins in Maine

USGS Publications Warehouse

Hodgkins, Glenn A.; Hebson, Charles; Lombard, Pamela J.; Mann, Alexander

2007-01-01

Understanding the accuracy of commonly used methods for estimating peak streamflows is important because the designs of bridges, culverts, and other river structures are based on these flows. Different methods for estimating peak streamflows were analyzed for small drainage basins in Maine. For the smallest basins, with drainage areas of 0.2 to 1.0 square mile, nine peak streamflows from actual rainfall events at four crest-stage gaging stations were modeled by the Rational Method and the Natural Resource Conservation Service TR-20 method and compared to observed peak flows. The Rational Method had a root mean square error (RMSE) of -69.7 to 230 percent (which means that approximately two thirds of the modeled flows were within -69.7 to 230 percent of the observed flows). The TR-20 method had an RMSE of -98.0 to 5,010 percent. Both the Rational Method and TR-20 underestimated the observed flows in most cases. For small basins, with drainage areas of 1.0 to 10 square miles, modeled peak flows were compared to observed statistical peak flows with return periods of 2, 50, and 100 years for 17 streams in Maine and adjoining parts of New Hampshire. Peak flows were modeled by the Rational Method, the Natural Resources Conservation Service TR-20 method, U.S. Geological Survey regression equations, and the Probabilistic Rational Method. The regression equations were the most accurate method of computing peak flows in Maine for streams with drainage areas of 1.0 to 10 square miles with an RMSE of -34.3 to 52.2 percent for 50-year peak flows. The Probabilistic Rational Method was the next most accurate method (-38.5 to 62.6 percent). The Rational Method (-56.1 to 128 percent) and particularly the TR-20 method (-76.4 to 323 percent) had much larger errors. Both the TR-20 and regression methods had similar numbers of underpredictions and overpredictions. The Rational Method overpredicted most peak flows and the Probabilistic Rational Method tended to overpredict peak flows from the smaller (less than 5 square miles) drainage basins and underpredict peak flows from larger drainage basins. The results of this study are consistent with the most comprehensive analysis of observed and modeled peak streamflows in the United States, which analyzed statistical peak flows from 70 drainage basins in the Midwest and the Northwest.

Variability and Reproducibility of Segmental Longitudinal Strain Measurement: A Report From the EACVI-ASE Strain Standardization Task Force.

PubMed

Mirea, Oana; Pagourelias, Efstathios D; Duchenne, Jurgen; Bogaert, Jan; Thomas, James D; Badano, Luigi P; Voigt, Jens-Uwe

2018-01-01

In this study, we compared left ventricular (LV) segmental strain measurements obtained with different ultrasound machines and post-processing software packages. Global longitudinal strain (GLS) has proven to be a reproducible and valuable tool in clinical practice. Data about the reproducibility and intervendor differences of segmental strain measurements, however, are missing. We included 63 volunteers with cardiac magnetic resonance-proven infarct scar with segmental LV function ranging from normal to severely impaired. Each subject was examined within 2 h by a single expert sonographer with machines from multiple vendors. All 3 apical views were acquired twice to determine the test-retest and the intervendor variability. Segmental longitudinal peak systolic, end-systolic, and post-systolic strain were measured using 7 vendor-specific systems (Hitachi, Tokyo, Japan; Esaote, Florence, Italy; GE Vingmed Ultrasound, Horten, Norway; Philips, Andover, Massachusetts; Samsung, Seoul, South Korea; Siemens, Mountain View, California; and Toshiba, Otawara, Japan) and 2 independent software packages (Epsilon, Ann Arbor, Michigan; and TOMTEC, Unterschleissheim, Germany) and compared among vendors. Image quality and tracking feasibility differed among vendors (analysis of variance, p < 0.05). The absolute test-retest difference ranged from 2.5% to 4.9% for peak systolic, 2.6% to 5.0% for end-systolic, and 2.5% to 5.0% for post-systolic strain. The average segmental strain values varied significantly between vendors (up to 4.5%). Segmental strain parameters from each vendor correlated well with the mean of all vendors (r 2 range 0.58 to 0.81) but showed very different ranges of values. Bias and limits of agreement were up to -4.6 ± 7.5%. In contrast to GLS, LV segmental longitudinal strain measurements have a higher variability on top of the known intervendor bias. The fidelity of different software to follow segmental function varies considerably. We conclude that single segmental strain values should be used with caution in the clinic. Segmental strain pattern analysis might be a more robust alternative. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Petrogenesis and tectonic implications of Triassic mafic complexes with MORB/OIB affinities from the western Garzê-Litang ophiolitic mélange, central Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, Bin; Ma, Chang-Qian; Guo, Yu-Heng; Xiong, Fu-Hao; Guo, Pan; Zhang, Xin

2016-09-01

Although numerous Paleo-Tethyan ophiolites with mid-oceanic ridge basalts (MORB) and/or oceanic-island basalt (OIB) affinities have been reported in the central Tibetan Plateau (CTP), the origin and tectonic nature of these ophiolites are not well understood. The petrogenesis, mantle sources and geodynamic setting of the mafic rocks from these ophiolites are unclear, which is the main reason for this uncertainty. In this paper, we present new geochronological, mineralogical and Sr-Nd isotopic data for the Chayong and Xiewu mafic complexes in the western Garzê-Litang suture zone (GLS), a typical Paleo-Tethyan suture crossing the CTP. Zircon LA-ICP-MS U-Pb ages of 234 ± 3 Ma and 236 ± 2 Ma can be interpreted as formation times of the Chayong and Xiewu mafic complexes, respectively. The basalts and gabbros of the Chayong complex exhibit enriched MORB (E-MORB) compositional affinities except for a weak depletion of Nb, Ta and Ti relative to the primitive mantle, whereas the basalts and gabbros of the Xiewu complex display distinct E-MORB and OIB affinities. The geochemical features suggest a probable fractionation of olivine ± clinopyroxene ± plagioclase as well as insignificant crustal contamination. The geochemical and Sr-Nd isotopic data reveal that the Chayong mafic rocks may have been derived from depleted MORB-type mantle metasomatized by crustal components and Xiewu mafic rocks from enriched lithospheric mantle metasomatized by OIB-like components. The ratios of Zn/Fet, La/Yb and Sm/Yb indicate that these mafic melts were produced by the partial melting of garnet + minor spinel-bearing peridotite or spinel ± minor garnet-bearing peridotite. We propose that back-arc basin spreading associated with OIB/seamount recycling had occurred in the western GLS at least since the Middle Triassic times, and the decompression melting of the depleted MORB-type asthenosphere mantle and partial melting of sub-continental lithosphere were metasomatized by plume-related melts, such as OIB s, which led to the generation of the Chayong and Xiewu mafic melts.

Left atrial function to identify patients with atrial fibrillation at high risk of stroke: new insights from a large registry.

PubMed

Leung, Melissa; van Rosendael, Philippe J; Abou, Rachid; Ajmone Marsan, Nina; Leung, Dominic Y; Delgado, Victoria; Bax, Jeroen J

2018-04-21

Atrial fibrillation (AF) is an independent risk factor for ischaemic stroke. The CHA2DS2-VASc is the most widely used risk stratification model; however, echocardiographic refinement may be useful, particularly in low risk AF patients. The present study examined the association between advanced echocardiographic parameters and ischaemic stroke, independent of CHA2DS2-VASc score. One thousand, three hundred and sixty-one patients (mean age 65±12 years, 74% males) with first diagnosis of AF and baseline transthoracic echocardiogram were followed by chart review for the occurrence of stroke over a mean of 7.9 years. Left atrial (LA) volumes, LA reservoir strain, P-wave to A' duration on tissue Doppler imaging (PA-TDI, reflecting total atrial conduction time), and left ventricular (LV) global longitudinal strain (GLS) were evaluated in patients with and without stroke. The independent association of these echocardiographic parameters with the occurrence of ischaemic stroke was evaluated with Cox proportional hazard models. One-hundred patients (7%) developed an ischaemic stroke, representing an annualized stroke rate of 0.9%. The incident stroke rate in the year following the first diagnosis of AF was 2.6% in the entire population and higher than the remainder of the follow-up period. Left atrial reservoir (14.5% vs. 18.9%, P = 0.005) and conduit strains were reduced (10.5% vs. 13.5%, P = 0.013), and PA-TDI lengthened (166 ms vs. 141 ms, P < 0.001) in the stroke compared with non-stroke group, despite similar LV dimensions, LV ejection fraction, GLS, and LA volumes. Left atrial reservoir strain and PA-TDI were independently associated with risk of stroke in a model including CHA2DS2-VASc score, age, and anticoagulant use. The assessment of LA reservoir strain and PA-TDI on echocardiography after initial CHA2DS2-VASc scoring provides additional risk stratification for stroke and may be useful to guide decisions regarding anticoagulation for patients upon first diagnosis of AF.

Improved methods to estimate the effective impervious area in urban catchments using rainfall-runoff data

NASA Astrophysics Data System (ADS)

Ebrahimian, Ali; Wilson, Bruce N.; Gulliver, John S.

2016-05-01

Impervious surfaces are useful indicators of the urbanization impacts on water resources. Effective impervious area (EIA), which is the portion of total impervious area (TIA) that is hydraulically connected to the drainage system, is a better catchment parameter in the determination of actual urban runoff. Development of reliable methods for quantifying EIA rather than TIA is currently one of the knowledge gaps in the rainfall-runoff modeling context. The objective of this study is to improve the rainfall-runoff data analysis method for estimating EIA fraction in urban catchments by eliminating the subjective part of the existing method and by reducing the uncertainty of EIA estimates. First, the theoretical framework is generalized using a general linear least square model and using a general criterion for categorizing runoff events. Issues with the existing method that reduce the precision of the EIA fraction estimates are then identified and discussed. Two improved methods, based on ordinary least square (OLS) and weighted least square (WLS) estimates, are proposed to address these issues. The proposed weighted least squares method is then applied to eleven urban catchments in Europe, Canada, and Australia. The results are compared to map measured directly connected impervious area (DCIA) and are shown to be consistent with DCIA values. In addition, both of the improved methods are applied to nine urban catchments in Minnesota, USA. Both methods were successful in removing the subjective component inherent in the analysis of rainfall-runoff data of the current method. The WLS method is more robust than the OLS method and generates results that are different and more precise than the OLS method in the presence of heteroscedastic residuals in our rainfall-runoff data.

A Comprehensive Study of Gridding Methods for GPS Horizontal Velocity Fields

NASA Astrophysics Data System (ADS)

Wu, Yanqiang; Jiang, Zaisen; Liu, Xiaoxia; Wei, Wenxin; Zhu, Shuang; Zhang, Long; Zou, Zhenyu; Xiong, Xiaohui; Wang, Qixin; Du, Jiliang

2017-03-01

Four gridding methods for GPS velocities are compared in terms of their precision, applicability and robustness by analyzing simulated data with uncertainties from 0.0 to ±3.0 mm/a. When the input data are 1° × 1° grid sampled and the uncertainty of the additional error is greater than ±1.0 mm/a, the gridding results show that the least-squares collocation method is highly robust while the robustness of the Kriging method is low. In contrast, the spherical harmonics and the multi-surface function are moderately robust, and the regional singular values for the multi-surface function method and the edge effects for the spherical harmonics method become more significant with increasing uncertainty of the input data. When the input data (with additional errors of ±2.0 mm/a) are decimated by 50% from the 1° × 1° grid data and then erased in three 6° × 12° regions, the gridding results in these three regions indicate that the least-squares collocation and the spherical harmonics methods have good performances, while the multi-surface function and the Kriging methods may lead to singular values. The gridding techniques are also applied to GPS horizontal velocities with an average error of ±0.8 mm/a over the Chinese mainland and the surrounding areas, and the results show that the least-squares collocation method has the best performance, followed by the Kriging and multi-surface function methods. Furthermore, the edge effects of the spherical harmonics method are significantly affected by the sparseness and geometric distribution of the input data. In general, the least-squares collocation method is superior in terms of its robustness, edge effect, error distribution and stability, while the other methods have several positive features.

Kennard-Stone combined with least square support vector machine method for noncontact discriminating human blood species

NASA Astrophysics Data System (ADS)

Zhang, Linna; Li, Gang; Sun, Meixiu; Li, Hongxiao; Wang, Zhennan; Li, Yingxin; Lin, Ling

2017-11-01

Identifying whole bloods to be either human or nonhuman is an important responsibility for import-export ports and inspection and quarantine departments. Analytical methods and DNA testing methods are usually destructive. Previous studies demonstrated that visible diffuse reflectance spectroscopy method can realize noncontact human and nonhuman blood discrimination. An appropriate method for calibration set selection was very important for a robust quantitative model. In this paper, Random Selection (RS) method and Kennard-Stone (KS) method was applied in selecting samples for calibration set. Moreover, proper stoichiometry method can be greatly beneficial for improving the performance of classification model or quantification model. Partial Least Square Discrimination Analysis (PLSDA) method was commonly used in identification of blood species with spectroscopy methods. Least Square Support Vector Machine (LSSVM) was proved to be perfect for discrimination analysis. In this research, PLSDA method and LSSVM method was used for human blood discrimination. Compared with the results of PLSDA method, this method could enhance the performance of identified models. The overall results convinced that LSSVM method was more feasible for identifying human and animal blood species, and sufficiently demonstrated LSSVM method was a reliable and robust method for human blood identification, and can be more effective and accurate.

The crux of the method: assumptions in ordinary least squares and logistic regression.

PubMed

Long, Rebecca G

2008-10-01

Logistic regression has increasingly become the tool of choice when analyzing data with a binary dependent variable. While resources relating to the technique are widely available, clear discussions of why logistic regression should be used in place of ordinary least squares regression are difficult to find. The current paper compares and contrasts the assumptions of ordinary least squares with those of logistic regression and explains why logistic regression's looser assumptions make it adept at handling violations of the more important assumptions in ordinary least squares.

An Angular Method with Position Control for Block Mesh Squareness Improvement

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

Yao, J.; Stillman, D.

We optimize a target function de ned by angular properties with a position control term for a basic stencil with a block-structured mesh, to improve element squareness in 2D and 3D. Comparison with the condition number method shows that besides a similar mesh quality regarding orthogonality can be achieved as the former does, the new method converges faster and provides a more uniform global mesh spacing in our numerical tests.

Potential energy surface fitting by a statistically localized, permutationally invariant, local interpolating moving least squares method for the many-body potential: Method and application to N{sub 4}

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

Bender, Jason D.; Doraiswamy, Sriram; Candler, Graham V., E-mail: truhlar@umn.edu, E-mail: candler@aem.umn.edu

2014-02-07

Fitting potential energy surfaces to analytic forms is an important first step for efficient molecular dynamics simulations. Here, we present an improved version of the local interpolating moving least squares method (L-IMLS) for such fitting. Our method has three key improvements. First, pairwise interactions are modeled separately from many-body interactions. Second, permutational invariance is incorporated in the basis functions, using permutationally invariant polynomials in Morse variables, and in the weight functions. Third, computational cost is reduced by statistical localization, in which we statistically correlate the cutoff radius with data point density. We motivate our discussion in this paper with amore » review of global and local least-squares-based fitting methods in one dimension. Then, we develop our method in six dimensions, and we note that it allows the analytic evaluation of gradients, a feature that is important for molecular dynamics. The approach, which we call statistically localized, permutationally invariant, local interpolating moving least squares fitting of the many-body potential (SL-PI-L-IMLS-MP, or, more simply, L-IMLS-G2), is used to fit a potential energy surface to an electronic structure dataset for N{sub 4}. We discuss its performance on the dataset and give directions for further research, including applications to trajectory calculations.« less

Quantitative determination of additive Chlorantraniliprole in Abamectin preparation: Investigation of bootstrapping soft shrinkage approach by mid-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Yan, Hong; Song, Xiangzhong; Tian, Kuangda; Chen, Yilin; Xiong, Yanmei; Min, Shungeng

2018-02-01

A novel method, mid-infrared (MIR) spectroscopy, which enables the determination of Chlorantraniliprole in Abamectin within minutes, is proposed. We further evaluate the prediction ability of four wavelength selection methods, including bootstrapping soft shrinkage approach (BOSS), Monte Carlo uninformative variable elimination (MCUVE), genetic algorithm partial least squares (GA-PLS) and competitive adaptive reweighted sampling (CARS) respectively. The results showed that BOSS method obtained the lowest root mean squared error of cross validation (RMSECV) (0.0245) and root mean squared error of prediction (RMSEP) (0.0271), as well as the highest coefficient of determination of cross-validation (Qcv2) (0.9998) and the coefficient of determination of test set (Q2test) (0.9989), which demonstrated that the mid infrared spectroscopy can be used to detect Chlorantraniliprole in Abamectin conveniently. Meanwhile, a suitable wavelength selection method (BOSS) is essential to conducting a component spectral analysis.

Demand Forecasting: An Evaluation of DODs Accuracy Metric and Navys Procedures

DTIC Science & Technology

2016-06-01

inventory management improvement plan, mean of absolute scaled error, lead time adjusted squared error, forecast accuracy, benchmarking, naïve method...Manager JASA Journal of the American Statistical Association LASE Lead-time Adjusted Squared Error LCI Life Cycle Indicator MA Moving Average MAE...Mean Squared Error xvi NAVSUP Naval Supply Systems Command NDAA National Defense Authorization Act NIIN National Individual Identification Number

Optical NOR logic gate design on square lattice photonic crystal platform

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

D’souza, Nirmala Maria, E-mail: nirmala@cukerala.ac.in; Mathew, Vincent, E-mail: vincent@cukerala.ac.in

We numerically demonstrate a new configuration of all-optical NOR logic gate with square lattice photonic crystal (PhC) waveguide using finite difference time domain (FDTD) method. The logic operations are based on interference effect of optical waves. We have determined the operating frequency range by calculating the band structure for a perfectly periodic PhC using plane wave expansion (PWE) method. Response time of this logic gate is 1.98 ps and it can be operated with speed about 513 GB/s. The proposed device consists of four linear waveguides and a square ring resonator waveguides on PhC platform.

Chemometrics resolution and quantification power evaluation: Application on pharmaceutical quaternary mixture of Paracetamol, Guaifenesin, Phenylephrine and p-aminophenol

NASA Astrophysics Data System (ADS)

Yehia, Ali M.; Mohamed, Heba M.

2016-01-01

Three advanced chemmometric-assisted spectrophotometric methods namely; Concentration Residuals Augmented Classical Least Squares (CRACLS), Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) and Principal Component Analysis-Artificial Neural Networks (PCA-ANN) were developed, validated and benchmarked to PLS calibration; to resolve the severely overlapped spectra and simultaneously determine; Paracetamol (PAR), Guaifenesin (GUA) and Phenylephrine (PHE) in their ternary mixture and in presence of p-aminophenol (AP) the main degradation product and synthesis impurity of Paracetamol. The analytical performance of the proposed methods was described by percentage recoveries, root mean square error of calibration and standard error of prediction. The four multivariate calibration methods could be directly used without any preliminary separation step and successfully applied for pharmaceutical formulation analysis, showing no excipients' interference.

Orthogonalizing EM: A design-based least squares algorithm

PubMed Central

Xiong, Shifeng; Dai, Bin; Huling, Jared; Qian, Peter Z. G.

2016-01-01

We introduce an efficient iterative algorithm, intended for various least squares problems, based on a design of experiments perspective. The algorithm, called orthogonalizing EM (OEM), works for ordinary least squares and can be easily extended to penalized least squares. The main idea of the procedure is to orthogonalize a design matrix by adding new rows and then solve the original problem by embedding the augmented design in a missing data framework. We establish several attractive theoretical properties concerning OEM. For the ordinary least squares with a singular regression matrix, an OEM sequence converges to the Moore-Penrose generalized inverse-based least squares estimator. For ordinary and penalized least squares with various penalties, it converges to a point having grouping coherence for fully aliased regression matrices. Convergence and the convergence rate of the algorithm are examined. Finally, we demonstrate that OEM is highly efficient for large-scale least squares and penalized least squares problems, and is considerably faster than competing methods when n is much larger than p. Supplementary materials for this article are available online. PMID:27499558

Salt-induced square prism Pd microtubes and their ethanol electrocatalysis properties

NASA Astrophysics Data System (ADS)

Jiang, Kunpeng; Ma, Shenghua; Wang, Yinan; Zhang, Ying; Han, Xiaojun

2017-05-01

The synthesis of square prism tubes are always challenging due to their thermo and dynamical instability. We demonstrated a simple method using Pd2+ doped PoPD oligomers as building blocks to assemble into 1D square prism metal-organic microtubes, which consists of cataphracted nanosheets on the surfaces. After high temperature treatment, the microtubes became square prism Pd tubes with a cross section size of 3 μm. The pure Pd microtubes showed excellent catalyzing activity towards the electro oxidation of ethanol. Their electrochemically active surface area is 48.2 m2 g-1, which indicates the square prism Pd tubes have great potential in the field of fuel cell.

Instrumentation for Measurement of Gas Permeability of Polymeric Membranes

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Wood, George M.; Brown, Kenneth G.; Burns, Karen S.

1993-01-01

A mass spectrometric 'Dynamic Delta' method for the measurement of gas permeability of polymeric membranes has been developed. The method is universally applicable for measurement of the permeability of any gas through polymeric membrane materials. The usual large sample size of more than 100 square centimeters required for other methods is not necessary for this new method which requires a size less than one square centimeter. The new method should fulfill requirements and find applicability for industrial materials such as food packaging, contact lenses and other commercial materials where gas permeability or permselectivity properties are important.

QCL spectroscopy combined with the least squares method for substance analysis

NASA Astrophysics Data System (ADS)

Samsonov, D. A.; Tabalina, A. S.; Fufurin, I. L.

2017-11-01

The article briefly describes distinctive features of quantum cascade lasers (QCL). It also describes an experimental set-up for acquiring mid-infrared absorption spectra using QCL. The paper demonstrates experimental results in the form of normed spectra. We tested the application of the least squares method for spectrum analysis. We used this method for substance identification and extraction of concentration data. We compare the results with more common methods of absorption spectroscopy. Eventually, we prove the feasibility of using this simple method for quantitative and qualitative analysis of experimental data acquired with QCL.

New model for prediction binary mixture of antihistamine decongestant using artificial neural networks and least squares support vector machine by spectrophotometry method

NASA Astrophysics Data System (ADS)

Mofavvaz, Shirin; Sohrabi, Mahmoud Reza; Nezamzadeh-Ejhieh, Alireza

2017-07-01

In the present study, artificial neural networks (ANNs) and least squares support vector machines (LS-SVM) as intelligent methods based on absorption spectra in the range of 230-300 nm have been used for determination of antihistamine decongestant contents. In the first step, one type of network (feed-forward back-propagation) from the artificial neural network with two different training algorithms, Levenberg-Marquardt (LM) and gradient descent with momentum and adaptive learning rate back-propagation (GDX) algorithm, were employed and their performance was evaluated. The performance of the LM algorithm was better than the GDX algorithm. In the second one, the radial basis network was utilized and results compared with the previous network. In the last one, the other intelligent method named least squares support vector machine was proposed to construct the antihistamine decongestant prediction model and the results were compared with two of the aforementioned networks. The values of the statistical parameters mean square error (MSE), Regression coefficient (R2), correlation coefficient (r) and also mean recovery (%), relative standard deviation (RSD) used for selecting the best model between these methods. Moreover, the proposed methods were compared to the high- performance liquid chromatography (HPLC) as a reference method. One way analysis of variance (ANOVA) test at the 95% confidence level applied to the comparison results of suggested and reference methods that there were no significant differences between them.

Simultaneous spectrophotometric determination of four metals by two kinds of partial least squares methods

NASA Astrophysics Data System (ADS)

Gao, Ling; Ren, Shouxin

2005-10-01

Simultaneous determination of Ni(II), Cd(II), Cu(II) and Zn(II) was studied by two methods, kernel partial least squares (KPLS) and wavelet packet transform partial least squares (WPTPLS), with xylenol orange and cetyltrimethyl ammonium bromide as reagents in the medium pH = 9.22 borax-hydrochloric acid buffer solution. Two programs, PKPLS and PWPTPLS, were designed to perform the calculations. Data reduction was performed using kernel matrices and wavelet packet transform, respectively. In the KPLS method, the size of the kernel matrix is only dependent on the number of samples, thus the method was suitable for the data matrix with many wavelengths and fewer samples. Wavelet packet representations of signals provide a local time-frequency description, thus in the wavelet packet domain, the quality of the noise removal can be improved. In the WPTPLS by optimization, wavelet function and decomposition level were selected as Daubeches 12 and 5, respectively. Experimental results showed both methods to be successful even where there was severe overlap of spectra.

Comparison of three newton-like nonlinear least-squares methods for estimating parameters of ground-water flow models

USGS Publications Warehouse

Cooley, R.L.; Hill, M.C.

1992-01-01

Three methods of solving nonlinear least-squares problems were compared for robustness and efficiency using a series of hypothetical and field problems. A modified Gauss-Newton/full Newton hybrid method (MGN/FN) and an analogous method for which part of the Hessian matrix was replaced by a quasi-Newton approximation (MGN/QN) solved some of the problems with appreciably fewer iterations than required using only a modified Gauss-Newton (MGN) method. In these problems, model nonlinearity and a large variance for the observed data apparently caused MGN to converge more slowly than MGN/FN or MGN/QN after the sum of squared errors had almost stabilized. Other problems were solved as efficiently with MGN as with MGN/FN or MGN/QN. Because MGN/FN can require significantly more computer time per iteration and more computer storage for transient problems, it is less attractive for a general purpose algorithm than MGN/QN.

An O(N squared) method for computing the eigensystem of N by N symmetric tridiagonal matrices by the divide and conquer approach

NASA Technical Reports Server (NTRS)

Gill, Doron; Tadmor, Eitan

1988-01-01

An efficient method is proposed to solve the eigenproblem of N by N Symmetric Tridiagonal (ST) matrices. Unlike the standard eigensolvers which necessitate O(N cubed) operations to compute the eigenvectors of such ST matrices, the proposed method computes both the eigenvalues and eigenvectors with only O(N squared) operations. The method is based on serial implementation of the recently introduced Divide and Conquer (DC) algorithm. It exploits the fact that by O(N squared) of DC operations, one can compute the eigenvalues of N by N ST matrix and a finite number of pairs of successive rows of its eigenvector matrix. The rest of the eigenvectors--all of them or one at a time--are computed by linear three-term recurrence relations. Numerical examples are presented which demonstrate the superiority of the proposed method by saving an order of magnitude in execution time at the expense of sacrificing a few orders of accuracy.

Variable selection based on clustering analysis for improvement of polyphenols prediction in green tea using synchronous fluorescence spectra

NASA Astrophysics Data System (ADS)

Shan, Jiajia; Wang, Xue; Zhou, Hao; Han, Shuqing; Riza, Dimas Firmanda Al; Kondo, Naoshi

2018-04-01

Synchronous fluorescence spectra, combined with multivariate analysis were used to predict flavonoids content in green tea rapidly and nondestructively. This paper presented a new and efficient spectral intervals selection method called clustering based partial least square (CL-PLS), which selected informative wavelengths by combining clustering concept and partial least square (PLS) methods to improve models’ performance by synchronous fluorescence spectra. The fluorescence spectra of tea samples were obtained and k-means and kohonen-self organizing map clustering algorithms were carried out to cluster full spectra into several clusters, and sub-PLS regression model was developed on each cluster. Finally, CL-PLS models consisting of gradually selected clusters were built. Correlation coefficient (R) was used to evaluate the effect on prediction performance of PLS models. In addition, variable influence on projection partial least square (VIP-PLS), selectivity ratio partial least square (SR-PLS), interval partial least square (iPLS) models and full spectra PLS model were investigated and the results were compared. The results showed that CL-PLS presented the best result for flavonoids prediction using synchronous fluorescence spectra.

Variable selection based on clustering analysis for improvement of polyphenols prediction in green tea using synchronous fluorescence spectra.

PubMed

Shan, Jiajia; Wang, Xue; Zhou, Hao; Han, Shuqing; Riza, Dimas Firmanda Al; Kondo, Naoshi

2018-03-13

Synchronous fluorescence spectra, combined with multivariate analysis were used to predict flavonoids content in green tea rapidly and nondestructively. This paper presented a new and efficient spectral intervals selection method called clustering based partial least square (CL-PLS), which selected informative wavelengths by combining clustering concept and partial least square (PLS) methods to improve models' performance by synchronous fluorescence spectra. The fluorescence spectra of tea samples were obtained and k-means and kohonen-self organizing map clustering algorithms were carried out to cluster full spectra into several clusters, and sub-PLS regression model was developed on each cluster. Finally, CL-PLS models consisting of gradually selected clusters were built. Correlation coefficient (R) was used to evaluate the effect on prediction performance of PLS models. In addition, variable influence on projection partial least square (VIP-PLS), selectivity ratio partial least square (SR-PLS), interval partial least square (iPLS) models and full spectra PLS model were investigated and the results were compared. The results showed that CL-PLS presented the best result for flavonoids prediction using synchronous fluorescence spectra.