A possible width-luminosity correlation of the Ca II K1 and Mg II k1 features. [of stellar atmospheres

NASA Technical Reports Server (NTRS)

Ayres, T. R.; Shine, R. A.; Linsky, J. L.

1975-01-01

Existing high resolution stellar profiles of the Ca II and Mg II resonance lines suggest a possible width-luminosity correlation of the K1 minimum features. It is shown that such a correlation can be simply understood if the continuum optical depth of the stellar temperature minimum is relatively independent of surface gravity as suggested by three stars studied in detail.

Reef structure drives parrotfish species composition on shelf edge reefs in La Parguera, Puerto Rico

NASA Astrophysics Data System (ADS)

Tzadik, Orian E.; Appeldoorn, Richard S.

2013-02-01

Shelf edge reefs that exist in coral reef ecosystems provide essential habitats for a large variety of fish and other marine organisms. Marine herbivores act as differential algal grazers that advocate coral reef colonization. In the Caribbean basin parrotfishes make up a large contingency of such herbivores and act as important ecological ichthyofauna. By investigating parrotfish relationship with habitat, this study aims to aid in future predictive mapping techniques that will outline parrotfish distributions via benthic quantification. Parrotfish communities were evaluated on the shelf edge reef off of La Parguera, Puerto Rico. Parrotfish abundances were found to positively correlate with high values of overall reef structure. High values of coral cover and of rugosity were strong indicators of most parrotfish species. The lone exception, Scarus taeniopterus, negatively correlated with these factors and positively correlated with algal cover. Indications exist that Scarus taeniopterus and Scarus iseri are sympatric species and can be found in abundance at opposite locations.

Amplification of the basic reproduction number in cattle farm networks

PubMed Central

2018-01-01

The popularly known 20–80 rule or Pareto rule states that 20% of efforts leads to 80% of results. This rule has been applied to the study of infection transmission in contact networks, and specifically, contact networks between cattle farms. Woolhouse and collaborators showed that targeting interventions for disease control and prevention to the 20% of the farms that contribute the most to the basic reproduction number (Ro), could reduce it by 80%. The rule results from the number of incoming and outgoing contacts per farm being highly heterogeneous. Besides, Woolhouse and collaborators showed that this high contact heterogeneity, together with a high positive correlation between the number of incoming and outgoing animal movements per farm leads to an amplification in the Ro. Two previous studies carried out with Scottish cattle transport data found either no correlation or only a weak correlation (rho up to 0.33) when using weighted data. Using data from the contacts between Swiss cattle farms in 2015, we found that the 20–80 rule applies with respect to Ro, although the proportion of highly active farms is smaller (11%). Besides, a positive strong correlation (rho = 0.64, weighted data) between the incoming and outgoing contacts of farms exists. This means that the amplification of Ro (due to the contact heterogeneities and the existing correlation) in cattle contact networks can be much higher than known until now. Our results highlight the importance of an effective active surveillance, more so than in other countries were these amplification mechanisms are absent. PMID:29672512

The Relationship of Grade Span in 9th Grade to Math Achievement in High School

ERIC Educational Resources Information Center

West, John; Miller, Mary Lou; Myers, Jim; Norton, Timothy

2015-01-01

Purpose, Scope, and Method of Study: The purpose of this study was to determine if a correlation exists between grade span for ninth grade and gains in math achievement test scores in 10th grade and 12th grade. A quantitative, longitudinal, correlational research design was employed to investigate the research questions. The population was high…

Feature Genes Selection Using Supervised Locally Linear Embedding and Correlation Coefficient for Microarray Classification

PubMed Central

Wang, Yun; Huang, Fangzhou

2018-01-01

The selection of feature genes with high recognition ability from the gene expression profiles has gained great significance in biology. However, most of the existing methods have a high time complexity and poor classification performance. Motivated by this, an effective feature selection method, called supervised locally linear embedding and Spearman's rank correlation coefficient (SLLE-SC2), is proposed which is based on the concept of locally linear embedding and correlation coefficient algorithms. Supervised locally linear embedding takes into account class label information and improves the classification performance. Furthermore, Spearman's rank correlation coefficient is used to remove the coexpression genes. The experiment results obtained on four public tumor microarray datasets illustrate that our method is valid and feasible. PMID:29666661

Feature Genes Selection Using Supervised Locally Linear Embedding and Correlation Coefficient for Microarray Classification.

PubMed

Xu, Jiucheng; Mu, Huiyu; Wang, Yun; Huang, Fangzhou

2018-01-01

The selection of feature genes with high recognition ability from the gene expression profiles has gained great significance in biology. However, most of the existing methods have a high time complexity and poor classification performance. Motivated by this, an effective feature selection method, called supervised locally linear embedding and Spearman's rank correlation coefficient (SLLE-SC 2 ), is proposed which is based on the concept of locally linear embedding and correlation coefficient algorithms. Supervised locally linear embedding takes into account class label information and improves the classification performance. Furthermore, Spearman's rank correlation coefficient is used to remove the coexpression genes. The experiment results obtained on four public tumor microarray datasets illustrate that our method is valid and feasible.

The Angular Correlation Function of Galaxies from Early Sloan Digital Sky Survey Data

NASA Astrophysics Data System (ADS)

Connolly, Andrew J.; Scranton, Ryan; Johnston, David; Dodelson, Scott; Eisenstein, Daniel J.; Frieman, Joshua A.; Gunn, James E.; Hui, Lam; Jain, Bhuvnesh; Kent, Stephen; Loveday, Jon; Nichol, Robert C.; O'Connell, Liam; Postman, Marc; Scoccimarro, Roman; Sheth, Ravi K.; Stebbins, Albert; Strauss, Michael A.; Szalay, Alexander S.; Szapudi, István; Tegmark, Max; Vogeley, Michael S.; Zehavi, Idit; Annis, James; Bahcall, Neta; Brinkmann, J.; Csabai, István; Doi, Mamoru; Fukugita, Masataka; Hennessy, G. S.; Hindsley, Robert; Ichikawa, Takashi; Ivezić, Željko; Kim, Rita S. J.; Knapp, Gillian R.; Kunszt, Peter; Lamb, D. Q.; Lee, Brian C.; Lupton, Robert H.; McKay, Timothy A.; Munn, Jeff; Peoples, John; Pier, Jeff; Rockosi, Constance; Schlegel, David; Stoughton, Christopher; Tucker, Douglas L.; Yanny, Brian; York, Donald G.

2002-11-01

The Sloan Digital Sky Survey is one of the first multicolor photometric and spectroscopic surveys designed to measure the statistical properties of galaxies within the local universe. In this paper we present some of the initial results on the angular two-point correlation function measured from the early SDSS galaxy data. The form of the correlation function, over the magnitude interval 18

Environmental interpretation using insoluble residues within reef coral skeletons: problems, pitfalls, and preliminary results

NASA Astrophysics Data System (ADS)

Budd, Ann F.; Mann, Keith O.; Guzmán, Hector M.

1993-03-01

Insoluble residue concentrations have been measured within colonies of four massive reef corals from seven localities along the Caribbean coast of Panama to determine if detrital sediments, incorporated within the skeletal lattice during growth, record changes in sedimentation over the past twenty years. Amounts of resuspended sediment have increased to varying degrees at the seven localities over the past decades in response to increased deforestation in nearby terrestrial habitats. Preliminary results of correlation and regression analyses reveal few consistent temporal trends in the insoluble residue concentration. Analyses of variance suggest that amounts of insoluble residues, however, differ among environments within species, but that no consistent pattern of variation exists among species. D. strigosa and P. astreoides possess high concentrations at protected localities, S. siderea at localities with high amounts of resuspended sediment, and M. annularis at the least turbid localities. Little correlation exists between insoluble residue concentration and growth band width within species at each locality. Only in two more efficient suspension feeders ( S. siderea and D. strigosa) do weak negative correlations with growth band width exist overall. These results indicate that insoluble residue concentrations cannot be used unequivocally in environmental interpretation, until more is known about tissue damage, polyp behavior, and their effects on the incorporation of insolubles in the skeleton during growth in different coral species. Insoluble residue data are highly variable; therefore, large sample sizes and strong contrasts between environments are required to reveal significant trends.

Water Vapor Transfer and Near-Surface Salinity Contrasts in the North Atlantic Ocean.

PubMed

Reagan, James; Seidov, Dan; Boyer, Tim

2018-06-11

Maintaining North Atlantic (NA) intra-basin near-surface salinity (NSS) contrast between the high NSS (>37.0) in the subtropical NA (STNA) and low NSS (<35.0) in the subpolar NA (SPNA) has been shown to be important in sustaining the strength of the Atlantic Meridional Overturning Circulation. Evaporation (E) exceeding precipitation (P) in the STNA is primarily responsible for the high NSS there, whereas P dominating E in the SPNA contributes to its low NSS. With a basic understanding of NA intra-basin moisture transport, a correlation analysis was conducted between E-P/NSS over the NA subpolar gyre (SPG) and E-P across the rest of the NA over the 1985-2012 time period. Significant anti-correlations exist between E-P/NSS over the NA SPG and E-P over the central/northern STNA. This suggests that during times of high E over the central/northern STNA there is high (low) precipitation (NSS) over the SPG demonstrating a relationship likely exists between E over the STNA and NSS over the SPG. The maximum anti-correlated area is poleward of the maximum E-P location in the STNA, which is examined. These results provide a first step to ultimately utilizing NSS in the NA as a proxy for estimating changes in the hydrological cycle.

Attitude-correlated frames approach for a star sensor to improve attitude accuracy under highly dynamic conditions.

PubMed

Ma, Liheng; Zhan, Dejun; Jiang, Guangwen; Fu, Sihua; Jia, Hui; Wang, Xingshu; Huang, Zongsheng; Zheng, Jiaxing; Hu, Feng; Wu, Wei; Qin, Shiqiao

2015-09-01

The attitude accuracy of a star sensor decreases rapidly when star images become motion-blurred under dynamic conditions. Existing techniques concentrate on a single frame of star images to solve this problem and improvements are obtained to a certain extent. An attitude-correlated frames (ACF) approach, which concentrates on the features of the attitude transforms of the adjacent star image frames, is proposed to improve upon the existing techniques. The attitude transforms between different star image frames are measured by the strap-down gyro unit precisely. With the ACF method, a much larger star image frame is obtained through the combination of adjacent frames. As a result, the degradation of attitude accuracy caused by motion-blurring are compensated for. The improvement of the attitude accuracy is approximately proportional to the square root of the number of correlated star image frames. Simulations and experimental results indicate that the ACF approach is effective in removing random noises and improving the attitude determination accuracy of the star sensor under highly dynamic conditions.

A cross-correlation-based estimate of the galaxy luminosity function

NASA Astrophysics Data System (ADS)

van Daalen, Marcel P.; White, Martin

2018-06-01

We extend existing methods for using cross-correlations to derive redshift distributions for photometric galaxies, without using photometric redshifts. The model presented in this paper simultaneously yields highly accurate and unbiased redshift distributions and, for the first time, redshift-dependent luminosity functions, using only clustering information and the apparent magnitudes of the galaxies as input. In contrast to many existing techniques for recovering unbiased redshift distributions, the output of our method is not degenerate with the galaxy bias b(z), which is achieved by modelling the shape of the luminosity bias. We successfully apply our method to a mock galaxy survey and discuss improvements to be made before applying our model to real data.

Exchange-correlation approximations for reduced-density-matrix-functional theory at finite temperature: Capturing magnetic phase transitions in the homogeneous electron gas

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

Baldsiefen, Tim; Cangi, Attila; Eich, F. G.

Here, we derive an intrinsically temperature-dependent approximation to the correlation grand potential for many-electron systems in thermodynamical equilibrium in the context of finite-temperature reduced-density-matrix-functional theory (FT-RDMFT). We demonstrate its accuracy by calculating the magnetic phase diagram of the homogeneous electron gas. We compare it to known limits from highly accurate quantum Monte Carlo calculations as well as to phase diagrams obtained within existing exchange-correlation approximations from density functional theory and zero-temperature RDMFT.

Exchange-correlation approximations for reduced-density-matrix-functional theory at finite temperature: Capturing magnetic phase transitions in the homogeneous electron gas

DOE PAGES

Baldsiefen, Tim; Cangi, Attila; Eich, F. G.; ...

2017-12-18

Here, we derive an intrinsically temperature-dependent approximation to the correlation grand potential for many-electron systems in thermodynamical equilibrium in the context of finite-temperature reduced-density-matrix-functional theory (FT-RDMFT). We demonstrate its accuracy by calculating the magnetic phase diagram of the homogeneous electron gas. We compare it to known limits from highly accurate quantum Monte Carlo calculations as well as to phase diagrams obtained within existing exchange-correlation approximations from density functional theory and zero-temperature RDMFT.

Effect of open wedge high tibial osteotomy on the lateral tibiofemoral compartment in sheep. Part III: analysis of the microstructure of the subchondral bone and correlations with the articular cartilage and meniscus.

PubMed

Ziegler, Raphaela; Goebel, Lars; Seidel, Roland; Cucchiarini, Magali; Pape, Dietrich; Madry, Henning

2015-09-01

First, to evaluate whether medial open wedge high tibial osteotomy (HTO) induces alterations of the microstructure of the lateral tibial subchondral bone plate of sheep. Second, to test the hypothesis that specific correlations exist between topographical structural alterations of the subchondral bone, the cartilage and the lateral meniscus. Three experimental groups received biplanar osteotomies of the right proximal tibiae: (a) closing wedge HTO (4.5° of tibial varus), (b) opening wedge HTO (4.5° tibial valgus; standard correction) and (c) opening wedge HTO (9.5° of valgus; overcorrection), each of which was compared to the non-osteotomised contralateral proximal tibiae. After 6 months, subchondral bone structure indices were measured by computed tomography. Correlations between the subchondral bone, the articular cartilage and the lateral meniscus were determined. Increased loading by valgus overcorrection led to an enlarged specific bone surface (BS/BV) in the subarticular spongiosa compared with unloading by varisation. The subchondral bone plate was 3.9-fold thicker in the central region of the lateral tibial plateau than in the submeniscal periphery. Its thickness in the central region significantly correlated with the thickness of the articular cartilage. In the submeniscal region, such correlation did not exist. In general, a higher degree of osteoarthritis (OA) correlated with alterations of the subchondral bone plate microstructure. OA of the submeniscal articular cartilage also correlated with worse matrix staining of the lateral meniscus. Osteoarthritis changes are associated with alterations of the subchondral bone plate microstructure. Specific topographical relationships exist in the central region between the articular cartilage and subchondral bone plate thickness, and in the submeniscal periphery between and the articular cartilage and lateral meniscus. From a clinical perspective, the combined follow-up data from this and the previous two investigations suggest that open wedge valgus HTO is a safe procedure for the lateral compartment to manage medial osteoarthritis of the knee with varus malalignment in the short term.

Examining High School Teachers' Experiences with Social and Emotional Learning: An Interpretative Phenomenological Analysis

ERIC Educational Resources Information Center

McCoy, Meghan K.

2016-01-01

Despite wide recognition that social and emotional learning (SEL) is correlated with increased emotional intelligence and well-developed social and emotional competencies, few opportunities exists for students at the high school level. This is likely due to the fact that teachers, those most often charged with providing SEL for students, report…

Analysis of high-resolution foreign exchange data of USD-JPY for 13 years

NASA Astrophysics Data System (ADS)

Mizuno, Takayuki; Kurihara, Shoko; Takayasu, Misako; Takayasu, Hideki

2003-06-01

We analyze high-resolution foreign exchange data consisting of 20 million data points of USD-JPY for 13 years to report firm statistical laws in distributions and correlations of exchange rate fluctuations. A conditional probability density analysis clearly shows the existence of trend-following movements at time scale of 8-ticks, about 1 min.

High-frequency sum rules for the quasi-one-dimensional quantum plasma dielectric tensor

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

Genga, R.O.

A high-frequency sum-rule expansion is derived for all elements of the spinless quasi-one-dimensional quantum plasma response tensor at T = 0 K. As in the magnetized classical plasmas, we find that Omega/sub 4//sup 13/ is the only coefficient of omega/sup -4/ that has no correlational term. Further, we find that the correlations either enhance or reduce the negative quantum dispersion, depending on the direction of propagation. It is also noted that the quantum effect does not exist for the ordinary and the extraordinary modes for perpendicular and parallel propagation, respectively.

Pre-Existing Immunity with High Neutralizing Activity to 2009 Pandemic H1N1 Influenza Virus in Shanghai Population

PubMed Central

Chen, Zhihui; Tang, Ziwei; Xu, Qingqiang; Wang, Yue; Zhao, Ping; Qi, Zhongtian

2013-01-01

Pre-existing immunity is an important factor countering the pandemic potential of an emerging influenza virus strain. Thus, studying of pre-existing immunity to the 2009 pandemic H1N1 virus (2009 H1N1) will advance our understanding of the pathogenesis and epidemiology of this emerging pathogen. In the present study, sera were collected from 486 individuals in a hospital in Shanghai, China, before the 2009 H1N1 influenza pandemic. The serum anti-hemagglutinins (HA) antibody, hemagglutination inhibition (HI) antibody and neutralizing antibody against the 2009 H1N1 were assayed. Among this population, 84.2%, 14.61% and 26.5% subjects possessed anti-HA antibody, HI antibody and neutralizing antibody, respectively. Although neutralizing antibody only existed in those sera with detectable anti-HA antibody, there was no obvious correlation between the titers of anti-HA and neutralizing antibody. However, the titers of anti-HA and neutralizing antibody against seasonal H1N1 virus were highly correlated. In the same population, there was no correlation between titers of neutralizing antibody against 2009 H1N1 and seasonal H1N1. DNA immunization performed on mice demonstrated that antibodies to the HA of 2009 pandemic and seasonal H1N1 influenza viruses were strain-specific and had no cross-neutralizing activity. In addition, the predicted conserved epitope in the HA of 2009 H1N1 and recently circulating seasonal H1N1 virus, GLFGAIAGFIE, was not an immunologically valid B-cell epitope. The data in this report are valuable for advancing our understanding of 2009 H1N1 influenza virus infection. PMID:23527030

A hybrid correlation analysis with application to imaging genetics

NASA Astrophysics Data System (ADS)

Hu, Wenxing; Fang, Jian; Calhoun, Vince D.; Wang, Yu-Ping

2018-03-01

Investigating the association between brain regions and genes continues to be a challenging topic in imaging genetics. Current brain region of interest (ROI)-gene association studies normally reduce data dimension by averaging the value of voxels in each ROI. This averaging may lead to a loss of information due to the existence of functional sub-regions. Pearson correlation is widely used for association analysis. However, it only detects linear correlation whereas nonlinear correlation may exist among ROIs. In this work, we introduced distance correlation to ROI-gene association analysis, which can detect both linear and nonlinear correlations and overcome the limitation of averaging operations by taking advantage of the information at each voxel. Nevertheless, distance correlation usually has a much lower value than Pearson correlation. To address this problem, we proposed a hybrid correlation analysis approach, by applying canonical correlation analysis (CCA) to the distance covariance matrix instead of directly computing distance correlation. Incorporating CCA into distance correlation approach may be more suitable for complex disease study because it can detect highly associated pairs of ROI and gene groups, and may improve the distance correlation level and statistical power. In addition, we developed a novel nonlinear CCA, called distance kernel CCA, which seeks the optimal combination of features with the most significant dependence. This approach was applied to imaging genetic data from the Philadelphia Neurodevelopmental Cohort (PNC). Experiments showed that our hybrid approach produced more consistent results than conventional CCA across resampling and both the correlation and statistical significance were increased compared to distance correlation analysis. Further gene enrichment analysis and region of interest (ROI) analysis confirmed the associations of the identified genes with brain ROIs. Therefore, our approach provides a powerful tool for finding the correlation between brain imaging and genomic data.

Biaxial deformation in high purity aluminum

DOE PAGES

Livescu, V.; Bingert, J. F.; Liu, C.; ...

2015-09-25

The convergence of multiple characterization tools has been applied to investigate the relationship of microstructure on damage evolution in high purity aluminum. The extremely coarse grain size of the disc-shaped sample provided a quasi-two dimensional structure from which the location of surface-measured features could be inferred. In particular, the role of pre-existing defects on damage growth was accessible due to the presence of casting porosity in the aluminum. Micro tomography, electron backscatter diffraction, and digital image correlation were applied to interrogate the sample in three dimensions. Recently micro-bulge testing apparatus was used to deform the pre-characterized disc of aluminum inmore » biaxial tension, and related analysis techniques were applied to map local strain fields. Subsequent post-mortem characterization of the failed sample was performed to correlate structure to damaged regions. We determined that strain localization and associated damage was most strongly correlated with grain boundary intersections and plastic anisotropy gradients between grains. Pre-existing voids played less of an apparent role than was perhaps initially expected. Finally, these combined techniques provide insight to the mechanism of damage initiation, propagation, and failure, along with a test bed for predictive damage models incorporating anisotropic microstructural effects.« less

A Structural Theory of Pitch1,2,3

PubMed Central

Laudanski, Jonathan; Zheng, Yi

2014-01-01

Abstract Musical notes can be ordered from low to high along a perceptual dimension called “pitch”. A characteristic property of these sounds is their periodic waveform, and periodicity generally correlates with pitch. Thus, pitch is often described as the perceptual correlate of the periodicity of the sound’s waveform. However, the existence and salience of pitch also depends in a complex way on other factors, in particular harmonic content. For example, periodic sounds made of high-order harmonics tend to have a weaker pitch than those made of low-order harmonics. Here we examine the theoretical proposition that pitch is the perceptual correlate of the regularity structure of the vibration pattern of the basilar membrane, across place and time—a generalization of the traditional view on pitch. While this proposition also attributes pitch to periodic sounds, we show that it predicts differences between resolved and unresolved harmonic complexes and a complex domain of existence of pitch, in agreement with psychophysical experiments. We also present a possible neural mechanism for pitch estimation based on coincidence detection, which does not require long delays, in contrast with standard temporal models of pitch. PMID:26464959

Application of the Gini correlation coefficient to infer regulatory relationships in transcriptome analysis.

PubMed

Ma, Chuang; Wang, Xiangfeng

2012-09-01

One of the computational challenges in plant systems biology is to accurately infer transcriptional regulation relationships based on correlation analyses of gene expression patterns. Despite several correlation methods that are applied in biology to analyze microarray data, concerns regarding the compatibility of these methods with the gene expression data profiled by high-throughput RNA transcriptome sequencing (RNA-Seq) technology have been raised. These concerns are mainly due to the fact that the distribution of read counts in RNA-Seq experiments is different from that of fluorescence intensities in microarray experiments. Therefore, a comprehensive evaluation of the existing correlation methods and, if necessary, introduction of novel methods into biology is appropriate. In this study, we compared four existing correlation methods used in microarray analysis and one novel method called the Gini correlation coefficient on previously published microarray-based and sequencing-based gene expression data in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). The comparisons were performed on more than 11,000 regulatory relationships in Arabidopsis, including 8,929 pairs of transcription factors and target genes. Our analyses pinpointed the strengths and weaknesses of each method and indicated that the Gini correlation can compensate for the shortcomings of the Pearson correlation, the Spearman correlation, the Kendall correlation, and the Tukey's biweight correlation. The Gini correlation method, with the other four evaluated methods in this study, was implemented as an R package named rsgcc that can be utilized as an alternative option for biologists to perform clustering analyses of gene expression patterns or transcriptional network analyses.

Application of the Gini Correlation Coefficient to Infer Regulatory Relationships in Transcriptome Analysis[W][OA

PubMed Central

Ma, Chuang; Wang, Xiangfeng

2012-01-01

One of the computational challenges in plant systems biology is to accurately infer transcriptional regulation relationships based on correlation analyses of gene expression patterns. Despite several correlation methods that are applied in biology to analyze microarray data, concerns regarding the compatibility of these methods with the gene expression data profiled by high-throughput RNA transcriptome sequencing (RNA-Seq) technology have been raised. These concerns are mainly due to the fact that the distribution of read counts in RNA-Seq experiments is different from that of fluorescence intensities in microarray experiments. Therefore, a comprehensive evaluation of the existing correlation methods and, if necessary, introduction of novel methods into biology is appropriate. In this study, we compared four existing correlation methods used in microarray analysis and one novel method called the Gini correlation coefficient on previously published microarray-based and sequencing-based gene expression data in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). The comparisons were performed on more than 11,000 regulatory relationships in Arabidopsis, including 8,929 pairs of transcription factors and target genes. Our analyses pinpointed the strengths and weaknesses of each method and indicated that the Gini correlation can compensate for the shortcomings of the Pearson correlation, the Spearman correlation, the Kendall correlation, and the Tukey’s biweight correlation. The Gini correlation method, with the other four evaluated methods in this study, was implemented as an R package named rsgcc that can be utilized as an alternative option for biologists to perform clustering analyses of gene expression patterns or transcriptional network analyses. PMID:22797655

The Mystery of the Mars North Polar Gravity-Topography Correlation(Or Lack Thereof)

NASA Technical Reports Server (NTRS)

Phillips, R. J.; Sjogren, W. L.; Johnson, C. L.

1999-01-01

Maps of moderately high resolution gravity data obtained from the Mars Global Surveyor (MGS) gravity calibration orbit campaign and high precision topography obtained from the Mars Orbiter Laser Altimeter (MOLA) experiment reveal relationships between gravity and topography in high northern latitudes of Mars. Figure 1 shows the results of a JPL spherical harmonic gravity model bandpass filtered between degrees 6 and 50 contoured over a MOLA topographic image. A positive gravity anomaly exists over the main North Polar cap, but there are at least six additional positive gravity anomalies, as well as a number of smaller negative anomalies, with no obvious correlation to topography. Additional information is contained in the original extended abstract.

Heat transfer for falling film evaporation of industrially relevant fluids up to very high Prandtl numbers

NASA Astrophysics Data System (ADS)

Gourdon, Mathias; Karlsson, Erik; Innings, Fredrik; Jongsma, Alfred; Vamling, Lennart

2016-02-01

In many industrial applications, falling film evaporation is an attractive technique for solvent removal due to high heat transfer and low residence times. Examples are the powder production in the dairy industry and in kraft pulp production process to remove water from so called black liquor. Common for both applications is that the fluids exhibit high viscosities in industrial practice. In this paper, results from experimental studies on both black liquor and a dairy product are reported for Prandtl numbers up to 800. The results are compared with several existing correlation in literature, and the need for a modified correlation is recognized especially to cover higher Prandtl-numbers. The following correlation for the turbulent flow region with 3 < Pr < 800 was derived from the data: {Nu}t = 0.0085 \\cdot Re^{0.2} \\cdot {Pr^{0.65}} The correlation has been compared to literature data from one additional study on two other fluids (propylene glycol and cyclohexanol) with fairly high Prandtl-numbers, from 40 to 58 and from 45 to 155 respectively and the agreement was within ±40 %.

Relationships among multiple trace elements in coastal Casuarina equisetifolia ecosystems on Hainan Island, South China.

PubMed

Liu, Qiang; Bi, Hua; Hung, Lan; Peng, Shaolin; Sheng, Chengde

2006-01-01

Forty-six trace elements in coastal Casuarina equisetifolia plant-soil systems at nine sampling sites on Hainan Island were analyzed using ICP-MS. The relationships among the trace elements of the same group or the same periodicity of the Periodic Table in the plants and soils were complex and no consistent patterns were found. More combinations of elements occurred with high positive correlation coefficients within the same periodicity than within the same group of the Periodic Table, and there were more high positive correlations in soils than in plants. However, there were many element combinations in Block d (transition elements) with high positive correlation coefficients in plants. Markedly high positive correlation coefficients between individual rare earth elements and Y and among Zr, Nb, Cd existed in both plants and soils. The dendrograms obtained by cluster analysis show that rare earth elements had very similar occurrence and distribution in both soils and plants. Thus, they behaved as a coherent group of elements both geochemically and biogeochemically. The transition elements were more coherent in plants than in soils.

Solar generated quasi-biennial geomagnetic variation

NASA Technical Reports Server (NTRS)

Sugiura, M.; Poros, D. J.

1977-01-01

The existence of highly correlated quasi-biennial variations in the geomagnetic field and in solar activity is demonstrated. The analysis uses a numerical filter technique applied to monthly averages of the geomagnetic horizontal component and of the Zurich relative sunspot number. Striking correlations are found between the quasi-biennial geomagnetic variations determined from several magnetic observatories located at widely different longitudes, indicating a worldwide nature of the obtained variation. The correlation coefficient between the filtered Dst index and the filtered relative sunspot number is found to be -0.79 at confidence level greater than 99% with a time-lag of 4 months, with solar activity preceding the Dst variation. The correlation between the unfiltered data of Dst and of the sunspot number is also high with a similar time-lag. Such a timelag has not been discussed in the literature, and a further study is required to establish the mode of sun-earth relationship that gives this time delay.

Measurements of the Low Frequency Gain Fluctuations of a 30 GHz High-Electron-Mobility-Transistor Cryogenic Amplifier

NASA Technical Reports Server (NTRS)

Jarosik, Norman

1994-01-01

Low frequency gain fluctuations of a 30 GHz cryogenic HEMT amplifier have been measured with the input of the amplifier connected to a 15 K load. Effects of fluctuations of other components of the test set-up were eliminated by use of a power-power correlation technique. Strong correlation between output power fluctuations of the amplifier and drain current fluctuations of the transistors comprising the amplifier are observed. The existence of these correlations introduces the possibility of regressing some of the excess noise from the HEMT amplifier's output using the measured drain currents.

A no-reference image and video visual quality metric based on machine learning

NASA Astrophysics Data System (ADS)

Frantc, Vladimir; Voronin, Viacheslav; Semenishchev, Evgenii; Minkin, Maxim; Delov, Aliy

2018-04-01

The paper presents a novel visual quality metric for lossy compressed video quality assessment. High degree of correlation with subjective estimations of quality is due to using of a convolutional neural network trained on a large amount of pairs video sequence-subjective quality score. We demonstrate how our predicted no-reference quality metric correlates with qualitative opinion in a human observer study. Results are shown on the EVVQ dataset with comparison existing approaches.

High Correlated Paternity Leads to Negative Effects on Progeny Performance in Two Mediterranean Shrub Species

PubMed Central

Nora, Sofia; Aparicio, Abelardo; Albaladejo, Rafael G.

2016-01-01

Anthropogenic habitat deterioration can promote changes in plant mating systems that subsequently may affect progeny performance, thereby conditioning plant recruitment for the next generation. However, very few studies yet tested mating system parameters other than outcrossing rates; and the direct effects of the genetic diversity of the pollen received by maternal plants (i.e. correlated paternity) has often been overlooked. In this study, we investigated the relation between correlated paternity and progeny performance in two common Mediterranean shrubs, Myrtus communis and Pistacia lentiscus. To do so, we collected open-pollinated progeny from selected maternal plants, calculated mating system parameters using microsatellite genotyping and conducted sowing experiments under greenhouse and field conditions. Our results showed that some progeny fitness components were negatively affected by the high correlated paternity of maternal plants. In Myrtus communis, high correlated paternity had a negative effect on the proportion and timing of seedling emergence in the natural field conditions and in the greenhouse sowing experiment, respectively. In Pistacia lentiscus, seedling emergence time under field conditions was also negatively influenced by high correlated paternity and a progeny survival analysis in the field experiment showed greater mortality of seedlings from maternal plants with high correlated paternity. Overall, we found effects of correlated paternity on the progeny performance of Myrtus communis, a self-compatible species. Further, we also detected effects of correlated paternity on the progeny emergence time and survival in Pistacia lentiscus, an obligate outcrossed species. This study represents one of the few existing empirical examples which highlight the influence that correlated paternity may exert on progeny performance in multiple stages during early seedling growth. PMID:27835658

High Correlated Paternity Leads to Negative Effects on Progeny Performance in Two Mediterranean Shrub Species.

PubMed

Nora, Sofia; Aparicio, Abelardo; Albaladejo, Rafael G

2016-01-01

Anthropogenic habitat deterioration can promote changes in plant mating systems that subsequently may affect progeny performance, thereby conditioning plant recruitment for the next generation. However, very few studies yet tested mating system parameters other than outcrossing rates; and the direct effects of the genetic diversity of the pollen received by maternal plants (i.e. correlated paternity) has often been overlooked. In this study, we investigated the relation between correlated paternity and progeny performance in two common Mediterranean shrubs, Myrtus communis and Pistacia lentiscus. To do so, we collected open-pollinated progeny from selected maternal plants, calculated mating system parameters using microsatellite genotyping and conducted sowing experiments under greenhouse and field conditions. Our results showed that some progeny fitness components were negatively affected by the high correlated paternity of maternal plants. In Myrtus communis, high correlated paternity had a negative effect on the proportion and timing of seedling emergence in the natural field conditions and in the greenhouse sowing experiment, respectively. In Pistacia lentiscus, seedling emergence time under field conditions was also negatively influenced by high correlated paternity and a progeny survival analysis in the field experiment showed greater mortality of seedlings from maternal plants with high correlated paternity. Overall, we found effects of correlated paternity on the progeny performance of Myrtus communis, a self-compatible species. Further, we also detected effects of correlated paternity on the progeny emergence time and survival in Pistacia lentiscus, an obligate outcrossed species. This study represents one of the few existing empirical examples which highlight the influence that correlated paternity may exert on progeny performance in multiple stages during early seedling growth.

Macro-modeling and micro-modeling tools for HOV-to-HOT lane analysis.

DOT National Transportation Integrated Search

2016-06-01

This report summarizes the analysis of observed commuting changes after conversion of an : existing carpool lane into a high-occupancy toll lane, on 15.5 miles of Atlanta I-85. The team explored the : correlations between observed changes in travel b...

Heat transfer and flow friction correlations for perforated plate matrix heat exchangers

NASA Astrophysics Data System (ADS)

Ratna Raju, L.; Kumar, S. Sunil; Chowdhury, K.; Nandi, T. K.

2017-02-01

Perforated plate matrix heat exchangers (MHE) are constructed of high conductivity perforated plates stacked alternately with low conductivity spacers. They are being increasingly used in many cryogenic applications including Claude cycle or Reversed Brayton cycle cryo-refrigerators and liquefiers. Design of high NTU (number of (heat) transfer unit) cryogenic MHEs requires accurate heat transfer coefficient and flow friction factor. Thermo-hydraulic behaviour of perforated plates strongly depends on the geometrical parameters. Existing correlations, however, are mostly expressed as functions of Reynolds number only. This causes, for a given configuration, significant variations in coefficients from one correlation to the other. In this paper we present heat transfer and flow friction correlations as functions of all geometrical and other controlling variables. A FluentTM based numerical model has been developed for heat transfer and pressure drop studies over a stack of alternately arranged perforated plates and spacers. The model is validated with the data from literature. Generalized correlations are obtained through regression analysis over a large number of computed data.

Quantum correlation exists in any non-product state

PubMed Central

Guo, Yu; Wu, Shengjun

2014-01-01

Simultaneous existence of correlation in complementary bases is a fundamental feature of quantum correlation, and we show that this characteristic is present in any non-product bipartite state. We propose a measure via mutually unbiased bases to study this feature of quantum correlation, and compare it with other measures of quantum correlation for several families of bipartite states. PMID:25434458

Noise Pollution and How it Can Indirectly Affect the Amounts of Particulate Matter in the Environment

NASA Astrophysics Data System (ADS)

Swamy, S.; Power, J.; Pham, D.; Preston, K. B.; Iqbal, A.

2007-12-01

Human and animal activity that occurs on gravel and dirt roads tends to contribute to high levels of particulate matter in the atmosphere. Birds molt their feathers, automobiles emit unused residues, and humans and animals stir up debris on the ground. Not only do these activities generate particulate matter, but they also generate noise. The aim of our study was to determine if a direct correlation exists between the amount of particulate matter and the noise levels in select areas within the Lake Merritt Park region of downtown Oakland, California. In addition, our research was aimed at determining if the level of noise at various locations conforms to City of Oakland regulations. Over a four-week period we measured noise levels and particulate matter concentrations at 27 different sites within the Park region. Preliminary results indicate that at a construction site and a residential area near the lake a direct correlation between our two variables existed; high noise level accompanied high particulate matter while low noise level accompanied low particulate matter, respectively. However, at the majority of the areas around the lake either indirect or no correlation was observed. Based on our results thus far, we conclude that noise levels are not indicative of particulate matter levels and that noise levels around Lake Merritt do conform to the city's regulations.

Hard probes of short-range nucleon-nucleon correlations

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

J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian

2012-10-01

The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nucleimore » and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.« less

Correlation between postoperative area of high autofluorescence in macula and visual acuity after macular hole closure.

PubMed

Zhang, Peng; Shang, Qingli; Ma, Jingxue; Hao, Yuhua; Ye, Cunxi

2017-03-20

To determine the correlation between the preoperative basal diameter of macular hole, the postoperative area of high autofluorescence (AF) in macula, and visual acuity in full-thickness macular hole. Forty-nine patients with full-thickness macular hole who underwent vitrectomy and C3F8 filling were reviewed. The preoperative diameter of macular hole, the 6 months postoperative area of high AF in macula if it existed, the length of inner segment/outer segment (IS/OS) defect, and visual acuity were obtained. The correlation between them was determined. At postoperative 6 months, the rate of high AF in macula was 63.3%. There were statistical differences between with and without high AF groups in postoperative best-corrected visual acuity (BCVA) (t = -2.751, p = 0.008), preoperative basal diameter of macular hole (t = -4.946, p = 0.00001), and postoperative length of IS/OS defect (t = -8.351, p<0.00001). Simple linear regression analysis showed high positive correlations between preoperative basal diameter of macular hole and area of high AF (p<0.00001, r = 0.893), postoperative length of IS/OS defect and area of high fundus AF (FAF) (p<0.00001, r = 0.779), and negative correlations between area of high AF and postoperative BCVA (p = 0.037, r = 0.375). There was low correlation between diameter of macular hole and postoperative BCVA (p = 0.112). The preoperative basal diameter of macular hole and postoperative length of IS/OS defect decides the postoperative area of high AF in macula to some degree, and the postoperative area of high AF in macula can be an evaluating indicator for poor macular function recovery.

High-performance conjugate-gradient benchmark: A new metric for ranking high-performance computing systems

DOE PAGES

Dongarra, Jack; Heroux, Michael A.; Luszczek, Piotr

2015-08-17

Here, we describe a new high-performance conjugate-gradient (HPCG) benchmark. HPCG is composed of computations and data-access patterns commonly found in scientific applications. HPCG strives for a better correlation to existing codes from the computational science domain and to be representative of their performance. Furthermore, HPCG is meant to help drive the computer system design and implementation in directions that will better impact future performance improvement.

Scrambling and thermalization in a diffusive quantum many-body system

DOE PAGES

Bohrdt, A.; Mendl, C. B.; Endres, M.; ...

2017-06-02

Out-of-time ordered (OTO) correlation functions describe scrambling of information in correlated quantum matter. They are of particular interest in incoherent quantum systems lacking well defined quasi-particles. Thus far, it is largely elusive how OTO correlators spread in incoherent systems with diffusive transport governed by a few globally conserved quantities. Here, we study the dynamical response of such a system using high-performance matrix-product-operator techniques. Specifically, we consider the non-integrable, one-dimensional Bose–Hubbard model in the incoherent high-temperature regime. Our system exhibits diffusive dynamics in time-ordered correlators of globally conserved quantities, whereas OTO correlators display a ballistic, light-cone spreading of quantum information. Themore » slowest process in the global thermalization of the system is thus diffusive, yet information spreading is not inhibited by such slow dynamics. We furthermore develop an experimentally feasible protocol to overcome some challenges faced by existing proposals and to probe time-ordered and OTO correlation functions. As a result, our study opens new avenues for both the theoretical and experimental exploration of thermalization and information scrambling dynamics.« less

Scrambling and thermalization in a diffusive quantum many-body system

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

Bohrdt, A.; Mendl, C. B.; Endres, M.

Out-of-time ordered (OTO) correlation functions describe scrambling of information in correlated quantum matter. They are of particular interest in incoherent quantum systems lacking well defined quasi-particles. Thus far, it is largely elusive how OTO correlators spread in incoherent systems with diffusive transport governed by a few globally conserved quantities. Here, we study the dynamical response of such a system using high-performance matrix-product-operator techniques. Specifically, we consider the non-integrable, one-dimensional Bose–Hubbard model in the incoherent high-temperature regime. Our system exhibits diffusive dynamics in time-ordered correlators of globally conserved quantities, whereas OTO correlators display a ballistic, light-cone spreading of quantum information. Themore » slowest process in the global thermalization of the system is thus diffusive, yet information spreading is not inhibited by such slow dynamics. We furthermore develop an experimentally feasible protocol to overcome some challenges faced by existing proposals and to probe time-ordered and OTO correlation functions. As a result, our study opens new avenues for both the theoretical and experimental exploration of thermalization and information scrambling dynamics.« less

Using Web and Social Media for Influenza Surveillance

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

Corley, Courtney D.; Cook, Diane; Mikler, Armin R.

2010-01-04

Analysis of Google influenza-like-illness (ILI) search queries has shown a strongly correlated pattern with Centers for Disease Control (CDC) and Prevention seasonal ILI reporting data.Web and social media provide another resource to detect increases in ILI. This paper evaluates trends in blog posts that discuss influenza. Our key finding is that from 5-October 2008 to 31-January 2009 a high correlation exists between the frequency of posts, containing influenza keywords, per week and CDC influenza-like-illness surveillance data.

A method for the design and development of medical or health care information websites to optimize search engine results page rankings on Google.

PubMed

Dunne, Suzanne; Cummins, Niamh Maria; Hannigan, Ailish; Shannon, Bill; Dunne, Colum; Cullen, Walter

2013-08-27

The Internet is a widely used source of information for patients searching for medical/health care information. While many studies have assessed existing medical/health care information on the Internet, relatively few have examined methods for design and delivery of such websites, particularly those aimed at the general public. This study describes a method of evaluating material for new medical/health care websites, or for assessing those already in existence, which is correlated with higher rankings on Google's Search Engine Results Pages (SERPs). A website quality assessment (WQA) tool was developed using criteria related to the quality of the information to be contained in the website in addition to an assessment of the readability of the text. This was retrospectively applied to assess existing websites that provide information about generic medicines. The reproducibility of the WQA tool and its predictive validity were assessed in this study. The WQA tool demonstrated very high reproducibility (intraclass correlation coefficient=0.95) between 2 independent users. A moderate to strong correlation was found between WQA scores and rankings on Google SERPs. Analogous correlations were seen between rankings and readability of websites as determined by Flesch Reading Ease and Flesch-Kincaid Grade Level scores. The use of the WQA tool developed in this study is recommended as part of the design phase of a medical or health care information provision website, along with assessment of readability of the material to be used. This may ensure that the website performs better on Google searches. The tool can also be used retrospectively to make improvements to existing websites, thus, potentially enabling better Google search result positions without incurring the costs associated with Search Engine Optimization (SEO) professionals or paid promotion.

Mortarboard Psychrometer

Treesearch

Dee F. Taylor

1963-01-01

Research has demonstrated that a high correlation exists between the moisture content of fine fuels and the moisture content of the ambient air. The mortarboard psychrometer was developed by the Southern Forest Fire Laboratory to provide a simple, accurate, yet inexpensive means of obtaining wet - and dry-bulb temperature readings to be used in estimating fine fuel...

Improving Reading Achievement in High Poverty, Rural Schools

ERIC Educational Resources Information Center

Tufts, Janet

2017-01-01

Purpose: The purpose of this quantitative study was to determine what correlation exists between a student's poverty coefficient and the daily number of minutes provided for independent reading and third grade reading achievement level as measured by California Assessment of Student Performance and Progress (CAASPP) in small, rural school…

Sex-Stereotypes in Israeli Primers: A Content Analysis Approach

ERIC Educational Resources Information Center

Zak, Itai; Kaufman, Shlomit

1977-01-01

Primary reading textbooks used in Israel were examined for sexual stereotyping. It was determined that male and female descriptions in the textbooks differ from true life situations. High correlations were also found between particular personality traits and sex in the books, which do not also exist in reality. (Author/MV)

Alertness Modulates Conflict Adaptation and Feature Integration in an Opposite Way

PubMed Central

Chen, Jia; Huang, Xiting; Chen, Antao

2013-01-01

Previous studies show that the congruency sequence effect can result from both the conflict adaptation effect (CAE) and feature integration effect which can be observed as the repetition priming effect (RPE) and feature overlap effect (FOE) depending on different experimental conditions. Evidence from neuroimaging studies suggests that a close correlation exists between the neural mechanisms of alertness-related modulations and the congruency sequence effect. However, little is known about whether and how alertness mediates the congruency sequence effect. In Experiment 1, the Attentional Networks Test (ANT) and a modified flanker task were used to evaluate whether the alertness of the attentional functions had a correlation with the CAE and RPE. In Experimental 2, the ANT and another modified flanker task were used to investigate whether alertness of the attentional functions correlate with the CAE and FOE. In Experiment 1, through the correlative analysis, we found a significant positive correlation between alertness and the CAE, and a negative correlation between the alertness and the RPE. Moreover, a significant negative correlation existed between CAE and RPE. In Experiment 2, we found a marginally significant negative correlation between the CAE and the RPE, but the correlation between alertness and FOE, CAE and FOE was not significant. These results suggest that alertness can modulate conflict adaptation and feature integration in an opposite way. Participants at the high alerting level group may tend to use the top-down cognitive processing strategy, whereas participants at the low alerting level group tend to use the bottom-up processing strategy. PMID:24250824

Quantum cryptography with a predetermined key, using continuous-variable Einstein-Podolsky-Rosen correlations

NASA Astrophysics Data System (ADS)

Reid, M. D.

2000-12-01

Correlations of the type discussed by EPR in their original 1935 paradox for continuous variables exist for the quadrature phase amplitudes of two spatially separated fields. These correlations were first experimentally reported in 1992. We propose to use such EPR beams in quantum cryptography, to transmit with high efficiency messages in such a way that the receiver and sender may later determine whether eavesdropping has occurred. The merit of the new proposal is in the possibility of transmitting a reasonably secure yet predetermined key. This would allow relay of a cryptographic key over long distances in the presence of lossy channels.

Electronic structure in high temperature superconducting oxides

NASA Astrophysics Data System (ADS)

Howell, R. H.; Sterne, P.; Solal, F.; Fluss, M. J.; Tobin, J.; Obrien, J.; Radousky, H. B.; Haghighi, H.; Kaiser, J. H.; Rayner, S. L.

1991-08-01

We have performed measurements on entwined single crystals of YBCO using both photoemission and positron angular correlation of annihilation radiation and on single crystals of LSCO using only angular correlation. Fermi surface features in good agreement with band theory were found and identified in all of the measurements. In photoemission, the Fermi momentum was fixed for several points and the band dispersion below the Fermi energy was mapped. In positron angular correlation measurements, the shape of the Fermi surface was mapped for the CuO chains (YBCO) and the CuO planes (LSCO). Demonstration of the existence of Fermi surfaces in the HTSC materials points a direction for future theoretical considerations.

Fundamental Movement Skills among Iranian Primary School Children.

PubMed

Aalizadeh, Bahman; Mohamadzadeh, Hassan; Hosseini, Fatemeh Sadat

2014-12-01

To determine the relationship between anthropometric indicators, physical activity (PA) and socioeconomic status (SES) with fundamental movement skills (FMS) among Iranian male students. In this descriptive study, based on SES scores, 241 students (7-10 years) were randomly selected and classified in high, medium and low groups. All children were measured by 8 morphology anthropometric measures. In order to examine a subset of manipulative skills and to measure physical activity and socioeconomic status, Test of Gross Motor Development (TGMD2) and, interviewer-administered questionnaires were used, respectively. The data were analyzed using Pearson correlation and multiple regression. There was a significant positive correlation between SES and body mass index (BMI), while a significant negative correlation existed between PA and BMI. Object control skills were significantly correlated with height, foot length, forearm length, hand length and physical activity. Students with low socioeconomic status were more qualified in movements than other students who were in medium and high socioeconomic status. Therefore, parents need to encourage students to be more active in order to prevent obesity and to facilitate development of object control skills in high socioeconomic status.

An Improved Correction for Range Restricted Correlations Under Extreme, Monotonic Quadratic Nonlinearity and Heteroscedasticity.

PubMed

Culpepper, Steven Andrew

2016-06-01

Standardized tests are frequently used for selection decisions, and the validation of test scores remains an important area of research. This paper builds upon prior literature about the effect of nonlinearity and heteroscedasticity on the accuracy of standard formulas for correcting correlations in restricted samples. Existing formulas for direct range restriction require three assumptions: (1) the criterion variable is missing at random; (2) a linear relationship between independent and dependent variables; and (3) constant error variance or homoscedasticity. The results in this paper demonstrate that the standard approach for correcting restricted correlations is severely biased in cases of extreme monotone quadratic nonlinearity and heteroscedasticity. This paper offers at least three significant contributions to the existing literature. First, a method from the econometrics literature is adapted to provide more accurate estimates of unrestricted correlations. Second, derivations establish bounds on the degree of bias attributed to quadratic functions under the assumption of a monotonic relationship between test scores and criterion measurements. New results are presented on the bias associated with using the standard range restriction correction formula, and the results show that the standard correction formula yields estimates of unrestricted correlations that deviate by as much as 0.2 for high to moderate selectivity. Third, Monte Carlo simulation results demonstrate that the new procedure for correcting restricted correlations provides more accurate estimates in the presence of quadratic and heteroscedastic test score and criterion relationships.

Change in the tropical cyclone activity around Korea by the East Asian summer monsoon

NASA Astrophysics Data System (ADS)

Choi, Jae-Won; Cha, Yumi; Kim, Jeoung-Yun

2017-12-01

Correlation between the frequency of summer tropical cyclones (TCs) affecting Korea and the East Asian summer monsoon index (EASMI) was analyzed over the last 37 years. A clear positive correlation existed between the two variables, and this high positive correlation remained unchanged even when excluding El Niño-Southern Oscillation (ENSO) years. To investigate the causes of the positive correlation between the two variables in non-ENSO years, after the 8 years with the highest EASMI (high EASMI years) and the 8 years with the lowest EASMI (low EASMI years) were selected, and the average difference between the two phases was analyzed. In high EASMI years, in the difference between the two phases regarding 850 and 500 hPa streamline, anomalous cyclones were reinforced in the tropical and subtropical western North Pacific, while anomalous anticyclones were reinforced in mid-latitude East Asian areas. Due to these two anomalous pressure systems, anomalous southeasterlies developed near Korea, with these anomalous southeasterlies playing the role of anomalous steering flows making the TCs head toward areas near Korea. In addition, a monsoon trough strengthened more eastward, and TCs in high EASMI years occurred more in east ward over the western North Pacific.

Relationship between teacher preparedness and inquiry-based instructional practices to students' science achievement: Evidence from TIMSS 2007

NASA Astrophysics Data System (ADS)

Martin, Lynn A.

The purpose of this study was to examine the relationship between teachers' self-reported preparedness for teaching science content and their instructional practices to the science achievement of eighth grade science students in the United States as demonstrated by TIMSS 2007. Six hundred eighty-seven eighth grade science teachers in the United States representing 7,377 students responded to the TIMSS 2007 questionnaire about their instructional preparedness and their instructional practices. Quantitative data were reported. Through correlation analysis, the researcher found statistically significant positive relationships emerge between eighth grade science teachers' main area of study and their self-reported beliefs about their preparedness to teach that same content area. Another correlation analysis found a statistically significant negative relationship existed between teachers' self-reported use of inquiry-based instruction and preparedness to teach chemistry, physics and earth science. Another correlation analysis discovered a statistically significant positive relationship existed between physics preparedness and student science achievement. Finally, a correlation analysis found a statistically significant positive relationship existed between science teachers' self-reported implementation of inquiry-based instructional practices and student achievement. The data findings support the conclusion that teachers who have feelings of preparedness to teach science content and implement more inquiry-based instruction and less didactic instruction produce high achieving science students. As science teachers obtain the appropriate knowledge in science content and pedagogy, science teachers will feel prepared and will implement inquiry-based instruction in science classrooms.

Correlation among the effective mass (m*), λab and Tc of superconducting cuprates in a Casimir energy scenario

NASA Astrophysics Data System (ADS)

Orlando, M. T. D.; Rouver, A. N.; Rocha, J. R.; Cavichini, A. S.

2018-06-01

The relevance of the Casimir effect, discovered in 1948, has recently been pointed out in studies on materials such as graphene and high-temperature superconducting cuprates. In particular, the relationship between Casimir energy and the energy of a superconducting condensate with anisotropy characterized by high bidimensionality has already been discussed in certain theoretical scenarios. Using this proposal, this work describes the relationship between the effective mass of the charge carriers (m* = αme) and the macroscopic parameters characteristic of several families of high-Tc superconducting cuprates (Cu-HTSC) that have copper and oxygen superconducting planes (Cu-O). We have verified that an expression exists that correlates the effective mass, the London penetration length in the plane λab, the critical temperature Tc and the distance d between the equivalent superconducting planes of Cu-HTSC. This study revealed that the intersection between the asymptotic behavior of α as a function of Tc and the line describing the optimal value of α ≃ 2 (m* ≃ 2me) indicates that a nonadiabatic region exists, which implies a carrier-lattice interaction and where the critical temperature can have its highest value in Cu-HTSC.

Urban and regional land use analysis: CARETS and Census Cities experiment package

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator); Milazzo, V. A.

1973-01-01

The author has identified the following significant results. Areas of post 1970 and 1972 land use changes were identified solely from the Skylab imagery from comparisons with 1970 land use maps. Most land use changes identified involved transition from agriculture to single family residential land use. The second most prominent changes identified from the Skylab imagery were areas presently under construction. Post 1970 changes from Skylab were compared with the 1972 changes noted from the high altitude photographs. A good correlation existed between the change polygons mapped from Skylab and those mapped from the 1972 high altitude aerial photos. In addition, there were a number of instances where additional built-up land use not noted in the 1972 aerial photo as being developed were identified on the Skylab imagery. While these cases have not been documented by field observation, by correlating these areas with the appearance of similar land use areas whose identity has been determined, we can safely say that we have been able to map further occurrences of land use change beyond existing high altitude photo coverage from the Skylab imagery. It was concluded that Skylab data can be used to detect areas of land use change within an urban setting.

An assessment of correlations between chlorinated VOC concentrations in tree tissue and groundwater for phytoscreening applications.

PubMed

Duncan, Candice M; Brusseau, Mark L

2018-03-01

The majority of prior phytoscreening applications have employed the method as a tool to qualitatively determine the presence of contamination in the subsurface. Although qualitative data is quite useful, this study explores the potential for using phytoscreening quantitatively. The existence of site-specific and non-site-specific (master) correlations between VOC concentrations in tree tissue and groundwater is investigated using data collected from several phytoscreening studies. The aggregated data comprise 100 measurements collected from 12 sites that span a wide range of site conditions. Significant site-specific correlations are observed between tetrachloroethene (PCE) and trichloroethene (TCE) concentrations measured for tree tissue and those measured in groundwater for three sites. A moderately significant correlation (r 2 =0.56) exists for the entire aggregate data set. Parsing the data by groundwater depth produced a highly significant correlation (r 2 =0.88) for sites with shallow (<4m) groundwater. Such a significant correlation for data collected by different investigators from multiple sites with a wide range of tree species and subsurface conditions indicates that groundwater concentration is the predominant factor mediating tree-tissue concentrations for these sites. This may be a result of trees likely directly tapping groundwater for these shallow groundwater conditions. This master correlation may provide reasonable order-of-magnitude estimates of VOC concentrations in groundwater for such sites, thereby allowing the use of phytoscreening in a more quantitative mode. Copyright © 2017 Elsevier B.V. All rights reserved.

Growth hormone-binding protein activity is inversely related to 24-hour growth hormone release in normal boys.

PubMed

Martha, P M; Rogol, A D; Blizzard, R M; Shaw, M A; Baumann, G

1991-07-01

To investigate the physiological relationship between serum GH-binding proteins and 24-h GH release, we compared the 24-h GH pulse attributes in serum samples obtained at 20-min intervals to the serum GH-binding protein activity (GH-BP) from 38 normal boys between 7 5/12 and 18 4/12 yr of age. GH-BP was determined in a serum sample from each study (containing less than 1.0 micrograms/L GH) using a standardized GH-BP assay. GH-BP results are expressed as the percentage of [125I]human GH bound to the high affinity GH-BP complex (peak II) per 160 microL serum. There were significant inverse relationships between the high affinity (receptor-related) GH-BP and several characteristics of 24-h GH release. Specifically, GH-BP was significantly (P less than 0.005 for all), but negatively, correlated with mean 24-h GH concentration (r = -0.62), sum of the GH pulse amplitudes (r = -0.57), sum of the GH pulse areas (r = -0.55), interpulse mean GH concentration (r = -0.53), and number of GH pulses per 24 h (r = -0.53). In addition, GH-BP correlated positively with the mean time interval between pulses (r = 0.59). There was also a significant positive correlation (r = 0.75; P less than 0.001) between GH-BP and the subject's age-adjusted body mass index SD score (BMI-SDS). Each characteristic of 24-h GH release correlating inversely with GH-BP also correlated inversely with BMI-SDS (P less than 0.01 for all comparisons). GH-BP did not, however, correlate with plasma insulin-like growth factor-I levels, serum testosterone concentrations, or height SDS. Binding to the low affinity GH-BP (peak I) did not correlate significantly with any of the examined GH pulse attributes, BMI-SDS, or the degree of binding to the high affinity GH-BP (peak II). We conclude that an inverse relationship exists between the high affinity serum GH-BP and 24-h GH release in boys under normal physiological conditions. We speculate that abnormalities in this relationship probably also exist and may underlie some disorders of growth.

The snake geothermal drilling project. Innovative approaches to geothermal exploration

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

Shervais, John W.; Evans, James P.; Liberty, Lee M.

2014-02-21

The goal of our project was to test innovative technologies using existing and new data, and to ground-truth these technologies using slim-hole core technology. The slim-hole core allowed us to understand subsurface stratigraphy and alteration in detail, and to correlate lithologies observed in core with surface based geophysical studies. Compiled data included geologic maps, volcanic vent distribution, structural maps, existing well logs and temperature gradient logs, groundwater temperatures, and geophysical surveys (resistivity, magnetics, gravity). New data included high-resolution gravity and magnetic surveys, high-resolution seismic surveys, three slimhole test wells, borehole wireline logs, lithology logs, water chemistry, alteration mineralogy, fracture distribution,more » and new thermal gradient measurements.« less

Transport of passive scalars in a turbulent channel flow

NASA Technical Reports Server (NTRS)

Kim, John; Moin, Parviz

1987-01-01

A direct numerical simulation of a turbulent channel flow with three passive scalars at different molecular Prandtl numbers is performed. Computed statistics including the turbulent Prandtl numbers are compared with existing experimental data. The computed fields are also examined to investigate the spatial structure of the scalar fields. The scalar fields are highly correlated with the streamwise velocity; the correlation coefficient between the temperature and the streamwise velocity is as high as 0.95 in the wall region. The joint probability distributions between the temperature and velocity fluctuations are also examined; they suggest that it might be possible to model the scalar fluxes in the wall region in a manner similar to the Reynolds stresses.

Factors affecting the strength of multipass low-alloy steel weld metal

NASA Technical Reports Server (NTRS)

Krantz, B. M.

1972-01-01

The mechanical properties of multipass high-strength steel weld metals depend upon several factors, among the most important being: (1) The interaction between the alloy composition and weld metal cooling rate which determines the as-deposited microstructure; and (2) the thermal effects of subsequent passes on each underlying pass which alter the original microstructure. The bulk properties of a multipass weld are therefore governed by both the initial microstructure of each weld pass and its subsequent thermal history. Data obtained for a high strength low alloy steel weld metal confirmed that a simple correlation exists between mechanical properties and welding conditions if the latter are in turn correlated as weld cooling rate.

Correlative cryogenic tomography of cells using light and soft x-rays

PubMed Central

Smith, Elizabeth A.; Cinquin, Bertrand P.; Do, Myan; McDermott, Gerry; Le Gros, Mark A.; Larabell, Carolyn A.

2013-01-01

Correlated imaging is the process of imaging a specimen with two complementary modalities, and then combining the two data sets to create a highly informative, composite view. A recent implementation of this concept has been the combination of soft x-ray tomography (SXT) with fluorescence cryogenic microscopy (FCM). SXT-FCM is used to visualize cells that are held in a near-native, cryo-preserved state. The resultant images are, therefore, highly representative of both the cellular architecture and molecular organization in vivo. SXT quantitatively visualizes the cell and sub-cellular structures; FCM images the spatial distribution of fluorescently labeled molecules. Here, we review the characteristics of SXT-FCM, and briefly discuss how this method compares with existing correlative imaging techniques. We also describe how the incorporation of a cryo-rotation stage into a cryogenic fluorescence microscope allows acquisition of fluorescence cryogenic tomography (FCT) data. FCT is optimally suited to correlation with SXT, since both techniques image the specimen in 3-D, potentially with similar, isotropic spatial resolution. PMID:24355261

Relation of assertiveness and anxiety among Iranian University students.

PubMed

Larijani, T T; Aghajani, M; Baheiraei, A; Neiestanak, N S

2010-12-01

• The findings from the present study revealed that less than 30% of nursing and midwifery students have high assertiveness and only half of them have low anxiety. • Assertiveness and anxiety have negative correlations in nursing and midwifery students and affect the mental health and educational and occupational performance of the students. • Many factors such as years of education and working while studying influence the level of assertiveness in the students. • The anxiety in students had a significant relation with the father's level of education, family income, etc. The simultaneous existence of low assertiveness and high anxiety in nursing and midwifery students leads to the disruption of study performance. There exists little information concerning their assertiveness. The purpose of this study was to determine the relation of assertiveness and anxiety in nursing and midwifery students. In this correlational, cross-sectional study, 173 nursing students (68 males and 105 females) and 77 midwifery students were recruited from the Tehran University of Medical Sciences in Iran. Data were collected using a questionnaire including personal-social factors, the Spielberger Trait Anxiety Inventory and the Assertion Inventory of Gambrill and Richey. More than half of the nursing and midwifery students (59.5% and 59.7%, respectively) had moderate assertiveness. Also, 43.3% and 36.4% of them had moderate and high levels of anxiety. Pearson correlation test revealed that assertiveness and anxiety had negative correlations in nursing (r=-0.51, P < 0.001) and midwifery (r=-0.449, P < 0.001) students. Some demographic variables had significant correlations with assertiveness and anxiety among the students. Considering the relation of assertiveness and anxiety and its effects on mental health and educational and occupational performance, students should be informed of the required skills for positive interaction with others and to increase assertiveness and decrease anxiety. © 2010 Blackwell Publishing.

Predictors of Instrumental Music Teacher Job Satisfaction

ERIC Educational Resources Information Center

Bryant, Robert Louis, III

2012-01-01

Previous research studies related to teacher quality have found that teacher attrition rates are at an all-time high. Although much research has been conducted in the area of job satisfaction within the general teaching population, few studies of job satisfaction exist for instrumental music teachers. The purpose of this correlational study was to…

Using Mood Ratings and Mood Induction in Assessment and Intervention for Severe Problem Behavior.

ERIC Educational Resources Information Center

Carr, Edward G.; McLaughlin, Darlene Magito; Giacobbe-Grieco, Theresa; Smith, Christopher E.

2003-01-01

A study examined whether a correlation existed between mood ratings and subsequent display of problem behavior in eight adults with mental retardation. Results indicated that bad mood ratings were highly predictive of problem behavior. When an induction procedure to improve mood ratings was implemented, dramatic decreases in problem behaviors…

Relationship between Teacher-Student Rapport and High-Stakes Testing Performance in Science

ERIC Educational Resources Information Center

Kimbro, Nathan Shawn

2017-01-01

The purpose of this predictive correlational study was to determine if a predictive relationship existed between teacher-student rapport, as perceived by students, and biology achievement scores. The Teacher-Student Likert Scale Questionnaire was used to measure students' perceptions of rapport with their science instructor. Students' scores on…

Hypothesis: discrepancy between intra- and interpopulation studies of the relationship between dietary salt and blood pressure: fact or fiction?

PubMed

Omvik, P

1984-01-01

It is a paradox that intra-population studies fail to show significant correlation between sodium excretion and blood pressure while a clear relationship exists in cross-cultural studies. Since daily variation of sodium excretion is high, the discrepancy between the two observations could be due to non-comparable data on sodium excretion. This is a discussion of the hypothesis that the finding of a significant correlation or not between sodium excretion and blood pressure depends on the statistical analysis of the data.

Optical long baseline intensity interferometry: prospects for stellar physics

NASA Astrophysics Data System (ADS)

Rivet, Jean-Pierre; Vakili, Farrokh; Lai, Olivier; Vernet, David; Fouché, Mathilde; Guerin, William; Labeyrie, Guillaume; Kaiser, Robin

2018-06-01

More than sixty years after the first intensity correlation experiments by Hanbury Brown and Twiss, there is renewed interest for intensity interferometry techniques for high angular resolution studies of celestial sources. We report on a successful attempt to measure the bunching peak in the intensity correlation function for bright stellar sources with 1 meter telescopes (I2C project). We propose further improvements of our preliminary experiments of spatial interferometry between two 1 m telescopes, and discuss the possibility to export our method to existing large arrays of telescopes.

Investigation of Antarctic crust and upper mantle using MAGSAT and other geophysical data

NASA Technical Reports Server (NTRS)

Bentley, C. R. (Principal Investigator)

1981-01-01

Progress in processing and analysis of Investigator B MAGSAT data is reported. Data processing tasks required prior to data analysis, including translation and reformatting of tapes and development of computer routines, were performed. A scalar anomaly map of Antarctica is near completion. Data analysis included a qualitative correlation of NASA's 4/81 scalar map of Antarctica with other geopotential data and correlation of POGO and continental scale gravity data with MAGSAT data. A magnetic high was found to exist over the Ross Embayment.

The Relationship of Red and Photographic Infrared Spectral Data to Grain Yield Variation Within a Winter Wheat Field

NASA Technical Reports Server (NTRS)

Tucker, C. J.; Holben, B. N.; Elgin, J. H., Jr.; Mcmurtrey, J. E., III

1979-01-01

Two band hand-held radiometer data from a winter wheat field, collected on 21 dates during the spring growing season, were correlated within field final grain yield. Significant linear relationships were found between various combinations of the red and photographic infrared radiance data collected and the grain yield. The spectral data explained approximately 64 percent of the within field grain yield variation. This variation in grain yield could not be explained using meteorological data as these were similar for all areas of the wheat field. Most importantly, data collected early in the spring were highly correlated with grain yield, a five week time window existed from stem elongation through antheses in which the spectral data were most highly correlated with grain yield, and manifestations of wheat canopy water stress were readily apparent in the spectral data.

Abscisic Acid Content and Stomatal Sensitivity to CO2 in Leaves of Xanthium strumarium L. after Pretreatments in Warm and Cold Growth Chambers 1

PubMed Central

Raschke, Klaus; Pierce, Margaret; Popiela, Chu Chen

1976-01-01

The degree of stomatal sensitivity to CO2 was positively correlated with the content of abscisic acid of leaves of Xanthium strumarium grown in a greenhouse and then transferred for 24 hours or more to a cold (5/10 C, night/day) or a warm growth chamber (20/23 C). This correlation did not exist in plants kept in the greehouse continuously (high abscisic acid, no CO2 sensitivity), nor in plants transferred from the cold to the warm chamber (low abscisic acid, high CO2 sensitivity). The abscisic acid content of leaves was correlated with water content only within narrow limits, if at all. At equal water contents, prechilled leaves contained more abscisic acid than leaves of plants pretreated in the warm chamber. There appear to be at least two compartments for abscisic acid in the leaf. PMID:16659416

Abscisic Acid Content and Stomatal Sensitivity to CO(2) in Leaves of Xanthium strumarium L. after Pretreatments in Warm and Cold Growth Chambers.

PubMed

Raschke, K; Pierce, M; Popiela, C C

1976-01-01

The degree of stomatal sensitivity to CO(2) was positively correlated with the content of abscisic acid of leaves of Xanthium strumarium grown in a greenhouse and then transferred for 24 hours or more to a cold (5/10 C, night/day) or a warm growth chamber (20/23 C). This correlation did not exist in plants kept in the greehouse continuously (high abscisic acid, no CO(2) sensitivity), nor in plants transferred from the cold to the warm chamber (low abscisic acid, high CO(2) sensitivity). The abscisic acid content of leaves was correlated with water content only within narrow limits, if at all. At equal water contents, prechilled leaves contained more abscisic acid than leaves of plants pretreated in the warm chamber. There appear to be at least two compartments for abscisic acid in the leaf.

Using beta coefficients to impute missing correlations in meta-analysis research: Reasons for caution.

PubMed

Roth, Philip L; Le, Huy; Oh, In-Sue; Van Iddekinge, Chad H; Bobko, Philip

2018-06-01

Meta-analysis has become a well-accepted method for synthesizing empirical research about a given phenomenon. Many meta-analyses focus on synthesizing correlations across primary studies, but some primary studies do not report correlations. Peterson and Brown (2005) suggested that researchers could use standardized regression weights (i.e., beta coefficients) to impute missing correlations. Indeed, their beta estimation procedures (BEPs) have been used in meta-analyses in a wide variety of fields. In this study, the authors evaluated the accuracy of BEPs in meta-analysis. We first examined how use of BEPs might affect results from a published meta-analysis. We then developed a series of Monte Carlo simulations that systematically compared the use of existing correlations (that were not missing) to data sets that incorporated BEPs (that impute missing correlations from corresponding beta coefficients). These simulations estimated ρ̄ (mean population correlation) and SDρ (true standard deviation) across a variety of meta-analytic conditions. Results from both the existing meta-analysis and the Monte Carlo simulations revealed that BEPs were associated with potentially large biases when estimating ρ̄ and even larger biases when estimating SDρ. Using only existing correlations often substantially outperformed use of BEPs and virtually never performed worse than BEPs. Overall, the authors urge a return to the standard practice of using only existing correlations in meta-analysis. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A New Polar Magnetic Index of Geomagnetic Activity and its Application to Monitoring Ionospheric Parameters

NASA Technical Reports Server (NTRS)

Lyatsky, Wladislaw; Khazanov, George V.

2008-01-01

For improving the reliability of Space Weather prediction, we developed a new, Polar Magnetic (PM) index of geomagnetic activity, which shows high correlation with both upstream solar wind data and related events in the magnetosphere and ionosphere. Similarly to the existing polar cap PC index, the new, PM index was computed from data from two near-pole geomagnetic observatories; however, the method for computing the PM index is different. The high correlation of the PM index with both solar wind data and events in Geospace environment makes possible to improve significantly forecasting geomagnetic disturbances and such important parameters as the cross-polar-cap voltage and global Joule heating in high latitude ionosphere, which play an important role in the development of geomagnetic, ionospheric and thermospheric disturbances. We tested the PM index for 10-year period (1995-2004). The correlation between PM index and upstream solar wind data for these years is very high (the average correlation coefficient R approximately equal to 0.86). The PM index also shows the high correlation with the cross-polar-cap voltage and hemispheric Joule heating (the correlation coefficient between the actual and predicted values of these parameters is approximately 0.9), which results in significant increasing the prediction reliability of these parameters. Using the PM index of geomagnetic activity provides a significant increase in the forecasting reliability of geomagnetic disturbances and related events in Geospace environment. The PM index may be also used as an important input parameter in modeling ionospheric, magnetospheric, and thermospheric processes.

A Graphical Modelling Approach to the Dissection of Highly Correlated Transcription Factor Binding Site Profiles

PubMed Central

Stojnic, Robert; Fu, Audrey Qiuyan; Adryan, Boris

2012-01-01

Inferring the combinatorial regulatory code of transcription factors (TFs) from genome-wide TF binding profiles is challenging. A major reason is that TF binding profiles significantly overlap and are therefore highly correlated. Clustered occurrence of multiple TFs at genomic sites may arise from chromatin accessibility and local cooperation between TFs, or binding sites may simply appear clustered if the profiles are generated from diverse cell populations. Overlaps in TF binding profiles may also result from measurements taken at closely related time intervals. It is thus of great interest to distinguish TFs that directly regulate gene expression from those that are indirectly associated with gene expression. Graphical models, in particular Bayesian networks, provide a powerful mathematical framework to infer different types of dependencies. However, existing methods do not perform well when the features (here: TF binding profiles) are highly correlated, when their association with the biological outcome is weak, and when the sample size is small. Here, we develop a novel computational method, the Neighbourhood Consistent PC (NCPC) algorithms, which deal with these scenarios much more effectively than existing methods do. We further present a novel graphical representation, the Direct Dependence Graph (DDGraph), to better display the complex interactions among variables. NCPC and DDGraph can also be applied to other problems involving highly correlated biological features. Both methods are implemented in the R package ddgraph, available as part of Bioconductor (http://bioconductor.org/packages/2.11/bioc/html/ddgraph.html). Applied to real data, our method identified TFs that specify different classes of cis-regulatory modules (CRMs) in Drosophila mesoderm differentiation. Our analysis also found depletion of the early transcription factor Twist binding at the CRMs regulating expression in visceral and somatic muscle cells at later stages, which suggests a CRM-specific repression mechanism that so far has not been characterised for this class of mesodermal CRMs. PMID:23144600

Ideal charge-density-wave order in the high-field state of superconducting YBCO

DOE PAGES

Jang, H.; Lee, W. -S.; Nojiri, H.; ...

2016-12-05

The existence of charge-density-wave (CDW) correlations in cuprate superconductors has now been established. However, the nature of the CDW ground state has remained uncertain because disorder and the presence of superconductivity typically limit the CDW correlation lengths to only a dozen unit cells or less. Here we explore the field-induced 3D CDW correlations in extremely pure detwinned crystals of YBa 2Cu 3O 2 (YBCO) ortho-II and ortho-VIII at magnetic fields in excess of the resistive upper critical field ( H c2) where superconductivity is heavily suppressed. We observe that the 3D CDW is unidirectional and possesses a long in-plane correlationmore » length as well as significant correlations between neighboring CuO 2 planes. It is significant that we observe only a single sharply defined transition at a critical field proportional to H c2, given that the field range used in this investigation overlaps with other high-field experiments including quantum oscillation measurements. The correlation volume is at least two to three orders of magnitude larger than that of the zero-field CDW. Furthermore, this is by far the largest CDW correlation volume observed in any cuprate crystal and so is presumably representative of the high-field ground state of an “ideal” disorder-free cuprate.« less

Androgen deficiency and dry eye syndrome in the aging male.

PubMed

Azcarate, Patrick M; Venincasa, Vincent D; Feuer, William; Stanczyk, Frank; Schally, Andrew V; Galor, Anat

2014-07-03

To evaluate the relationship between androgen levels and subjective and objective measures of dry eye syndrome (DES). A total of 263 male patients from the Miami Veterans Affairs Medical Center eye clinic aged ≥50 were recruited for this prospective cross-sectional study. Patients completed Dry Eye Questionnaire 5, underwent tear film evaluation, and had serum androgen levels measured. The correlations between androgen levels, DES composite scores, DES symptoms, and global, lipid, and aqueous tear film parameters were evaluated. Two hundred sixty-three patients with a mean age of 69 (50-95) were examined. There was no linear association between composite DES scores (generated using latent class analysis) and androgen levels. However, eyes with high DES scores (0.95-1.0) had higher levels of sex hormone-binding globulin (P = 0.03) and lower levels of dehydroepiandrosterone sulfate (DHEAS) (P = 0.02), androstenedione (A) (P = 0.02), and androstane-3α,17β-diol glucuronide (P = 0.03) compared to eyes with intermediate (0.05-0.95) or low (0-0.05) scores. There were no strong correlations between tear film measures and androgen levels. Regarding global parameters, a weak inverse correlation was found between corneal staining and A (r = -0.17, P = 0.009). For lipid parameters, a weak correlation existed between tear breakup time (TBUT) and A (r = 0.15, P = 0.02). When considering aqueous and lipid deficiency independently, the association between TBUT and A existed only with aqueous tear deficiency (r = 0.66, P = 0.002). Regarding aqueous parameters, a weak correlation existed between Schirmer test and DHEAS (r = 0.13, P = 0.047) and A (r = 0.21, P = 0.001). There was a weak correlation between higher levels of androstenedione and healthier global, lipid, and aqueous tear film parameters. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Social acceptance among tuberculosis patients at Puskesmas Amplas Medan, Indonesia

NASA Astrophysics Data System (ADS)

Eyanoer, P. C.

2018-03-01

Social acceptance is a confession, compilation, and appreciation for an individual which come from other individual or social groups in their entirety which makes individual feels safe, comfortable, and their existence is appreciated. A cross-sectional study consisted of 42 pulmonary TB patients registered at Puskesmas Amplas was done to analyze their social acceptance in the society. Data was collected by direct interview using structured questionnaire. The result showed that majority had either high and very high social acceptance with 45.20% and 31.0% respectively with high family support and high self-confidence (73.8%). Bivariate analysis showed a significant association between family support and self confidence with social acceptance (p value<0.05). The correlation coefficient (r) of self confidenceis 0.629 while family support were is 0.455 (p-value<0.05). This study concludes that both family support and self-confidence have a significant correlation with social acceptance.

Hole pairing and ground state properties of high-Tc superconductivity within the t-t'-J-V model

NASA Astrophysics Data System (ADS)

Roy, Krishanu; Pal, Papiya; Nath, Subhadip; Ghosh, Nanda Kumar

2018-04-01

The t-t'-J-V model, one of the realistic models for studying high-Tc cuprates, has been investigated to explore the hole pairing and other ground state properties using exact diagonalization (ED) technique with 2 holes in a small 8-site cluster. The role of next-nearest-neighbor (NNN) hopping and nearest-neighbor (NN) Coulomb repulsion has been considered. It appears that qualitative behavior of the ground state energies of an 8-site and 16- or 18-site cluster is similar. Results show that a small short-ranged antiferromagnetic (AF) correlation exists in the 2 hole case which is favored by large V/t. A superconducting phase emerges at 0 ≤ V/t ≤ 4J. Hole-hole correlation calculation also suggests that the two holes of the pair are either at |i - j| = 1 or √2. Negative t'/t suppresses the possibility of pairing of holes. Though s-wave pairing susceptibility is dominant, pairing correlation length calculation indicates that the long range pairing, which is suitable for superconductivity, is in the d-wave channel. Both s- and d-wave pairing susceptibility gets suppressed by V/t while d-(s-) wave susceptibility gets favored (suppressed) by t'/t. The charge gap shows a gapped behavior while a spin-gapless region exists at small V/t for finite t'/t.

Open-source platform to benchmark fingerprints for ligand-based virtual screening

PubMed Central

2013-01-01

Similarity-search methods using molecular fingerprints are an important tool for ligand-based virtual screening. A huge variety of fingerprints exist and their performance, usually assessed in retrospective benchmarking studies using data sets with known actives and known or assumed inactives, depends largely on the validation data sets used and the similarity measure used. Comparing new methods to existing ones in any systematic way is rather difficult due to the lack of standard data sets and evaluation procedures. Here, we present a standard platform for the benchmarking of 2D fingerprints. The open-source platform contains all source code, structural data for the actives and inactives used (drawn from three publicly available collections of data sets), and lists of randomly selected query molecules to be used for statistically valid comparisons of methods. This allows the exact reproduction and comparison of results for future studies. The results for 12 standard fingerprints together with two simple baseline fingerprints assessed by seven evaluation methods are shown together with the correlations between methods. High correlations were found between the 12 fingerprints and a careful statistical analysis showed that only the two baseline fingerprints were different from the others in a statistically significant way. High correlations were also found between six of the seven evaluation methods, indicating that despite their seeming differences, many of these methods are similar to each other. PMID:23721588

Activity and selectivity of photocatalysts in photodegradation of phenols.

PubMed

Emeline, A V; Zhang, X; Murakami, T; Fujishima, A

2012-04-15

Photodegradation of phenol and 4-chlorophenol over six different TiO(2) samples was tested in order to establish whether an interconnection between the activity and selectivity of photocatalysts exists. The obtained experimental data were analyzed using correlation analysis. Some correlations between the activity in phenol(s) photodegradation and selectivity toward formation of primary intermediate products were established. The type of correlations depends on the type of studied photoreactions. The discussion of the observed correlations between the activity and selectivity of photocatalysts is given in terms of the difference of surface concentrations of electrons and holes and corresponding surface active sites which might be dependent on the types of dominating surface faces. On the basis of the obtained results of correlation analysis it was assumed that a higher activity of photocatalysts could be achieved provided that both reduction and oxidation reaction pathways occur with equally high efficiency. Copyright © 2011 Elsevier B.V. All rights reserved.

Black holes from large N singlet models

NASA Astrophysics Data System (ADS)

Amado, Irene; Sundborg, Bo; Thorlacius, Larus; Wintergerst, Nico

2018-03-01

The emergent nature of spacetime geometry and black holes can be directly probed in simple holographic duals of higher spin gravity and tensionless string theory. To this end, we study time dependent thermal correlation functions of gauge invariant observables in suitably chosen free large N gauge theories. At low temperature and on short time scales the correlation functions encode propagation through an approximate AdS spacetime while interesting departures emerge at high temperature and on longer time scales. This includes the existence of evanescent modes and the exponential decay of time dependent boundary correlations, both of which are well known indicators of bulk black holes in AdS/CFT. In addition, a new time scale emerges after which the correlation functions return to a bulk thermal AdS form up to an overall temperature dependent normalization. A corresponding length scale was seen in equal time correlation functions in the same models in our earlier work.

Higher plasma level of STIM1, OPG are correlated with stent restenosis after PCI.

PubMed

Li, Haibin; Jiang, Zhian; Liu, Xiangdong; Yang, Zhihui

2015-01-01

Percutaneous Coronary Intervention (PCI) is one of the most effective treatments for Coronary Heart Disease (CHD), but the high rate of In Stent Restenosis (ISR) has plagued clinicians after PCI. We aim to investigate the correlation of plasma Stromal Interaction Molecular 1 (STIM1) and Osteoprotegerin (OPG) level with stent restenosis after PCI. A total of 100 consecutive patients with Coronary Heart Disease (CHD) received PCI procedure were recruited. Coronary angiography was performed 8 months after their PCI. Then patients were divided into 2 groups: observation group was composed by patients who existing postoperative stenosis after intervention; Control group was composed by patients with no postoperative stenosis. The plasma levels of STIM, OPG in all patients were tested before and after intervention. Pearson correlation and multiple linear regression analysis were performed to analysis the correlation between STIM, OPG level and postoperative stenosis. 35 cases were divided into observation group and other 65 were divided into control group. The plasma levels of STIM, OPG have no statistical difference before their PCI procedure, but we observed higher level of High-sensitivity C-reactive protein (Hs-CRP) existed in observation group. We observed higher level of plasma STIM, OPG in observation group when compared with control group after PCI procedure (P < 0.05). Regression analysis demonstrated that Hs-CRP, STIM1, OPG are independent risk factors for ISR. Elevated levels of plasma STIM1, OPG are independent risk factors for ISR in patients received PCI, which could provide useful information for the restenosis control after PCI.

Fundamental Movement Skills among Iranian Primary School Children

PubMed Central

Aalizadeh, Bahman; Mohamadzadeh, Hassan; Hosseini, Fatemeh Sadat

2014-01-01

Objective: To determine the relationship between anthropometric indicators, physical activity (PA) and socioeconomic status (SES) with fundamental movement skills (FMS) among Iranian male students. Materials and methods: In this descriptive study, based on SES scores, 241 students (7-10 years) were randomly selected and classified in high, medium and low groups. All children were measured by 8 morphology anthropometric measures. In order to examine a subset of manipulative skills and to measure physical activity and socioeconomic status, Test of Gross Motor Development (TGMD2) and, interviewer-administered questionnaires were used, respectively. The data were analyzed using Pearson correlation and multiple regression. Results: There was a significant positive correlation between SES and body mass index (BMI), while a significant negative correlation existed between PA and BMI. Object control skills were significantly correlated with height, foot length, forearm length, hand length and physical activity. Conclusion: Students with low socioeconomic status were more qualified in movements than other students who were in medium and high socioeconomic status. Therefore, parents need to encourage students to be more active in order to prevent obesity and to facilitate development of object control skills in high socioeconomic status. PMID:25530767

Stars and reionization: the cross-correlation of the 21 cm line and the near-infrared background

NASA Astrophysics Data System (ADS)

Fernandez, Elizabeth R.; Zaroubi, Saleem; Iliev, Ilian T.; Mellema, Garrelt; Jelić, Vibor

2014-05-01

With improving telescopes, it may now be possible to observe the Epoch of Reionization in multiple ways. We examine two of these observables - the excess light in the near-infrared background that may be due to high-redshift stars and ionized HII bubbles, and the 21 cm emission from neutral hydrogen. Because these two forms of emission should result from different, mutually exclusive regions, an anticorrelation should exist between them. We discuss the strengths of using cross-correlations between these observations to learn more about high-redshift star formation and reionization history. In particular, we create simulated maps of emission from both the near-infrared background and 21 cm emission. We find that these observations are anticorrelated, with the strongest anticorrelation originating from times when the universe is half ionized. This result is robust and does not depend on the properties of the stars themselves. Rather, it depends on the ionization history. Cross-correlations can provide redshift information, which the near-infrared background cannot provide alone. In addition, cross-correlations can help separate foreground emission from the true high-redshift component, making it possible to say with greater certainty that we are indeed witnessing the Epoch of Reionization.

North Atlantic Origin of Interdecadal variability of Siberian High

NASA Astrophysics Data System (ADS)

Kim, Seon-Hwa; Sung, Mi-Kyung; Kim, Baek-Min

2017-04-01

We suggest that the changes in the mean atmospheric circulation structure in the North Atlantic Ocean upstream region of Eurasian continent play an important role in the interdecadal variability of Siberian High (SH) through the modulation of Ural blocking frequency. Previous studies suggested that the interdecadal variability of SH is partly explained by the Arctic Oscillation. However, in this study, we emphasize the role of 'Warm Arctic and Cold Eurasia (WACE)', which is the second mode of winter surface air temperature variability over Eurasia. We show that the correlation between SH and WACE is high in general compared to that between SH and AO. However, the correlation between SH and WACE does not always exhibit high constant value. It shows a distinctive interdecadal fluctuation in the correlation. We found that this fluctuation in the correlation is due to the interdecadal fluctuation of the continental trough over the North Atlantic and the resultant strengthening of in-situ atmospheric baroclinicity. This accompanies changes in the transient vorticity flux divergence which leads to the downstream wave development and anomalous anticyclonic flow near Ural region. Obviously, the existence of anticyclonic flow over Ural region helps more frequent occurrence of Ural blocking and it is shown that this condition favors positive WACE event, which links to an intensified SH.

Intraseasonal Cold Air Outbreak over East Asia and the preceding atmospheric condition over the Barents-Kara Sea

NASA Astrophysics Data System (ADS)

Hori, M. E.; Inoue, J.

2011-12-01

Frequent occurrence of cold air outbreak is a dominant feature of the East Asian winter monsoon. A contributing factor for the this cold air outbreak is the role of stationary Rossby waves over the Eurasian continent which intensifies the surface Siberian High and the accompanying cold air outflow. Reduced sea ice and increase in turbulence heat flux is hypothesized as a source of such stationary waves (Honda et al. 2009). In particular, the winter of 2009/2010 saw a strong correlation of high pressure anomaly over the Barents/Kara sea and the following cold air buildup over the Eurasian continent and its advection towards East Asia (Hori et al. 2011). The lag correlation of surface temperature over Japan and the 850hPa geopotential height shows a cyclonic anomaly appearing over the Barents/Kara sea which creates a cold air advection over the Eurasian continent. The pressure anomaly subsequently shifted westward to mature into a blocking high which created a wave- train pattern downstream advecting the cold air buildup eastward toward East Asia and Japan (Fig1). We further examine this mechanism for other years including the 2005/2006, 2010/2011 winter and other winters with extreme cold air outbreaks. Overall, the existence of an anticyclonic anomaly over the Barents/Kara sea correlated well with the seasonal dominance of cold air over the Eurasian continent thereby creating a contrast of a warm Arctic and cold Eurasian continent.In the intraseasonal timescale, the existence of this anticyclone corresponds to a persisting atmospheric blocking in the high latitudes. In the presentation, we address the underlying chain of events leading up to a strong cold air outbreak over East Asia from an atmosphere - sea ice - land surafce interaction point of view for paritular cold winter years.

Construct Validity of the Multidimensional Structure of Bullying and Victimization: An Application of Exploratory Structural Equation Modeling

ERIC Educational Resources Information Center

Marsh, Herbert W.; Nagengast, Benjamin; Morin, Alexandre J. S.; Parada, Roberto H.; Craven, Rhonda G.; Hamilton, Linda R.

2011-01-01

Existing research posits multiple dimensions of bullying and victimization but has not identified well-differentiated facets of these constructs that meet standards of good measurement: goodness of fit, measurement invariance, lack of differential item functioning, and well-differentiated factors that are not so highly correlated as to detract…

Predicting the Plate Dent Test Output in Order to Assess the Performance of Condensed High Explosives

NASA Astrophysics Data System (ADS)

Frem, Dany

2017-01-01

In the present study, a relationship is proposed that is capable of predicting the output of the plate dent test. It is shown that the initial density ?; condensed phase heat of formation ?; the number of carbon (C), nitrogen (N), oxygen (O); and the composition molecular weight (MW) are the most important parameters needed in order to accurately predict the absolute dent depth ? produced on 1018 cold-rolled steel by a detonating organic explosive. The estimated ? values can be used to predict the detonation pressure (P) of high explosives; furthermore, we show that a correlation exists between ? and the Gurney velocity ? parameter. The new correlation is used to accurately estimate ? for several C-H-N-O explosive compositions.

Geomorphic Evidence for Martian Ground Ice and Climate Change

NASA Technical Reports Server (NTRS)

Kanner, L. C.; Allen, C. C.; Bell, M. S.

2004-01-01

Recent results from gamma-ray and neutron spectrometers on Mars Odyssey indicate the presence of a hydrogen-rich layer tens of centimeters thick in the uppermost meter in high latitudes (>60 ) on Mars. This hydrogen-rich layer correlates to regions of ice stability. Thus, the subsurface hydrogen is thought to be water ice constituting 35+/- 15% by weight near the north and south polar regions. We refine the location of subsurface ice deposits at a < km scale by combining existing spectroscopy data with surface features indicative of subsurface ice. A positive correlation between spectroscopy data and geomorphic ice indicators has been previously suggested for high latitudes. Here we expand the comparative study to northern mid latitudes (30 deg.N- 65 deg.N).

Burnout and the learning environment of anaesthetic trainees.

PubMed

Castanelli, D J; Wickramaarachchi, S A; Wallis, S

2017-11-01

Burnout has a high prevalence among healthcare workers and is increasingly recognised as an environmental problem rather than reflecting a personal inability to cope with work stress. We distributed an electronic survey, which included the Maslach Burnout Inventory Health Services Survey and a previously validated learning environment instrument, to 281 Victorian anaesthetic trainees. The response rate was 50%. We found significantly raised rates of burnout in two of three subscales. Ninety-one respondents (67%) displayed evidence of burnout in at least one domain, with 67 (49%) reporting high emotional exhaustion and 57 (42%) reporting high depersonalisation. The clinical learning environment tool demonstrated a significant negative correlation with burnout (r=-0.56, P <0.001). Burnout was significantly more common than when previously measured in Victoria in 2008 (62% versus 38%). Trainees rated examination preparation the most stressful aspect of the training program. There is a high prevalence of burnout among Victorian anaesthetic trainees. We have shown a significant correlation exists between the clinical learning environment measure and the presence of burnout. This correlation supports the development of interventions to improve the clinical learning environment, as a means to improve trainee wellbeing and address the high prevalence of burnout.

Brain-behaviour relationships in people at high genetic risk of schizophrenia.

PubMed

Lymer, G Katherine S; Job, Dominic E; William, T; Moorhead, J; McIntosh, Andrew M; Owens, David G C; Johnstone, Eve C; Lawrie, Stephen M

2006-10-15

The brain is known to be structurally abnormal in schizophrenia, with replicated findings between anatomical deficits and some dysfunctions. These structure-function associations have, however, only very rarely been studied in relatives at risk of schizophrenia. We studied the relationships between structure and schizotypal features (assessed using RISC and SIS) and verbal learning and memory (measured using RAVLT) in relatives at high risk of developing schizophrenia and normal controls. Since these behavioural test scores are strong predictors of schizophrenia in the Edinburgh High Risk Study, we hypothesised that these relationships would differ between those high-risk subjects who will develop schizophrenia from those who will not. We performed multiple regressions of the grey matter segments of the subjects and controls, produced using grey matter optimised, voxel-based morphometry, with their RAVLT, SIS and RISC scores in SPM. Where significant relationships were found, we used SPSS to test for subject group by behavioural score interactions. In those high-risk subjects who became ill, grey matter density (GMD) was significantly correlated with RISC in the left superior temporal gyrus. In subjects who remained well, SIS was significantly correlated with GMD in the right pulvinar. Across the whole HR group, GMD in the right medial dorsal thalamic nucleus was significantly correlated with RAVLT. In those subjects who developed symptoms, RAVLT significantly correlated with GMD in right parahippocampal gyrus whereas in those who became ill, significant correlations existed bilaterally in the pulvinar. These results suggest complex and changing patterns of structural-functional relationships in those subjects at high-risk of schizophrenia.

High prevalence of campylobacter excretors among Liberian children related to environmental conditions.

PubMed

Mølbak, K; Højlyng, N; Gaarslev, K

1988-04-01

Campylobacter was the bacterial pathogen most prevalent in 859 children, aged 6-59 months, examined in a house-to-house diarrhoea survey in two Liberian communities. 44.9% of the children from an urban slum and 28.4% from a rural area were excretors. Since the prevalence of diarrhoea was very high and consequently many convalescent carriers were found, it was not possible to evaluate the pathogenic role of campylobacter. The excretor rate increased with age and was significantly correlated to the use of supplementary feeding, inversely correlated to the quality of the water supply, and also associated with helminthic infestation. Results from re-examination of 172 children suggested a high intensity of transmission. The findings all indicate the existence of a heavy environmental contamination with campylobacter, probably of both human and animal faecal origin.

High prevalence of campylobacter excretors among Liberian children related to environmental conditions.

PubMed Central

Mølbak, K.; Højlyng, N.; Gaarslev, K.

1988-01-01

Campylobacter was the bacterial pathogen most prevalent in 859 children, aged 6-59 months, examined in a house-to-house diarrhoea survey in two Liberian communities. 44.9% of the children from an urban slum and 28.4% from a rural area were excretors. Since the prevalence of diarrhoea was very high and consequently many convalescent carriers were found, it was not possible to evaluate the pathogenic role of campylobacter. The excretor rate increased with age and was significantly correlated to the use of supplementary feeding, inversely correlated to the quality of the water supply, and also associated with helminthic infestation. Results from re-examination of 172 children suggested a high intensity of transmission. The findings all indicate the existence of a heavy environmental contamination with campylobacter, probably of both human and animal faecal origin. PMID:3356221

Self-Esteem: Models and Implications for Management

DTIC Science & Technology

1993-12-01

self - esteem is significantly correlated with a number of behaviors. In comparison to an individual with low self - esteem , an individual with high self ...seems to look at himself and say "I like what I see and I am going to give it its desires and needs," whereas the low self - esteem person seems to say...that May identified with low self - esteem . Therefore, high self - esteem will exist with those who have a recognized and

Development of a high-performance multichannel system for time-correlated single photon counting

NASA Astrophysics Data System (ADS)

Peronio, P.; Cominelli, A.; Acconcia, G.; Rech, I.; Ghioni, M.

2017-05-01

Time-Correlated Single Photon Counting (TCSPC) is one of the most effective techniques for measuring weak and fast optical signals. It outperforms traditional "analog" techniques due to its high sensitivity along with high temporal resolution. Despite those significant advantages, a main drawback still exists, which is related to the long acquisition time needed to perform a measurement. In past years many TCSPC systems have been developed with higher and higher number of channels, aimed to dealing with that limitation. Nevertheless, modern systems suffer from a strong trade-off between parallelism level and performance: the higher the number of channels the poorer the performance. In this work we present the design of a 32x32 TCSPC system meant for overtaking the existing trade-off. To this aim different technologies has been employed, to get the best performance both from detectors and sensing circuits. The exploitation of different technologies will be enabled by Through Silicon Vias (TSVs) which will be investigated as a possible solution for connecting the detectors to the sensing circuits. When dealing with a high number of channels, the count rate is inevitably set by the affordable throughput to the external PC. We targeted a throughput of 10Gb/s, which is beyond the state of the art, and designed the number of TCSPC channels accordingly. A dynamic-routing logic will connect the detectors to the lower number of acquisition chains.

A Method for the Design and Development of Medical or Health Care Information Websites to Optimize Search Engine Results Page Rankings on Google

PubMed Central

Cummins, Niamh Maria; Hannigan, Ailish; Shannon, Bill; Dunne, Colum; Cullen, Walter

2013-01-01

Background The Internet is a widely used source of information for patients searching for medical/health care information. While many studies have assessed existing medical/health care information on the Internet, relatively few have examined methods for design and delivery of such websites, particularly those aimed at the general public. Objective This study describes a method of evaluating material for new medical/health care websites, or for assessing those already in existence, which is correlated with higher rankings on Google's Search Engine Results Pages (SERPs). Methods A website quality assessment (WQA) tool was developed using criteria related to the quality of the information to be contained in the website in addition to an assessment of the readability of the text. This was retrospectively applied to assess existing websites that provide information about generic medicines. The reproducibility of the WQA tool and its predictive validity were assessed in this study. Results The WQA tool demonstrated very high reproducibility (intraclass correlation coefficient=0.95) between 2 independent users. A moderate to strong correlation was found between WQA scores and rankings on Google SERPs. Analogous correlations were seen between rankings and readability of websites as determined by Flesch Reading Ease and Flesch-Kincaid Grade Level scores. Conclusions The use of the WQA tool developed in this study is recommended as part of the design phase of a medical or health care information provision website, along with assessment of readability of the material to be used. This may ensure that the website performs better on Google searches. The tool can also be used retrospectively to make improvements to existing websites, thus, potentially enabling better Google search result positions without incurring the costs associated with Search Engine Optimization (SEO) professionals or paid promotion. PMID:23981848

Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.

PubMed

Monahan, William B; Tingley, Morgan W

2012-01-01

The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus). Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004) further shows that: (i) existing fundamental and occupied niche centroids did not undergo directional change, (ii) interannual changes in the two niche centroids were correlated, (iii) temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv) most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced changes to the realized environmental space. Such insights may be used to conceptualize mechanistic climatic niche models in birds and other taxa.

Revealing Spatial Variation and Correlation of Urban Travels from Big Trajectory Data

NASA Astrophysics Data System (ADS)

Li, X.; Tu, W.; Shen, S.; Yue, Y.; Luo, N.; Li, Q.

2017-09-01

With the development of information and communication technology, spatial-temporal data that contain rich human mobility information are growing rapidly. However, the consistency of multi-mode human travel behind multi-source spatial-temporal data is not clear. To this aim, we utilized a week of taxies' and buses' GPS trajectory data and smart card data in Shenzhen, China to extract city-wide travel information of taxi, bus and metro and tested the correlation of multi-mode travel characteristics. Both the global correlation and local correlation of typical travel indicator were examined. The results show that: (1) Significant differences exist in of urban multi-mode travels. The correlation between bus travels and taxi travels, metro travel and taxi travels are globally low but locally high. (2) There are spatial differences of the correlation relationship between bus, metro and taxi travel. These findings help us understanding urban travels deeply therefore facilitate both the transport policy making and human-space interaction research.

High Familial Correlation in Methylphenidate Response and Side Effect Profile.

PubMed

Gazer-Snitovsky, Michal; Brand-Gothelf, Ayelet; Dubnov-Raz, Gal; Weizman, Abraham; Gothelf, Doron

2015-04-21

To examine whether a familial tendency exists in clinical response to methylphenidate. Nineteen pairs of siblings or parent-child stimulant-naive individuals with ADHD were prescribed methylphenidate-immediate release, and were comprehensively evaluated at baseline, Week 2, and Week 4, using the ADHD Rating Scale IV, Clinical Global Impression Scale, and the Barkley Side Effects Rating Scale. We found significant intraclass correlations in family member response to methylphenidate-immediate release and side effect profile, including emotional symptoms and loss of appetite and weight. Family history of response to methylphenidate should be taken into account when treating ADHD. © 2015 SAGE Publications.

Memory texture as a mechanism of improvement in preference by adding noise

NASA Astrophysics Data System (ADS)

Zhao, Yinzhu; Aoki, Naokazu; Kobayashi, Hiroyuki

2014-02-01

According to color research, people have memory colors for familiar objects, which correlate with high color preference. As a similar concept to this, we propose memory texture as a mechanism of texture preference by adding image noise (1/f noise or white noise) to photographs of seven familiar objects. Our results showed that (1) memory texture differed from real-life texture; (2) no consistency was found between memory texture and real-life texture; (3) correlation existed between memory texture and preferred texture; and (4) the type of image noise which is more appropriate to texture reproduction differed by object.

Variability in the Correlation between Asian Dust Storms and Chlorophyll a Concentration from the North to Equatorial Pacific

PubMed Central

Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

2013-01-01

A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997–2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the <50 m China seas because atmospheric deposition is commonly believed to exert less impact on coastal seas. Significant correlations existed between dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54–0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32–0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (<0.36). These correlation coefficients were further interpreted in terms of the geographical distributions of dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas. PMID:23460892

Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

PubMed

Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

2013-01-01

A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the <50 m China seas because atmospheric deposition is commonly believed to exert less impact on coastal seas. Significant correlations existed between dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54-0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (<0.36). These correlation coefficients were further interpreted in terms of the geographical distributions of dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas.

Correlative cryogenic tomography of cells using light and soft x-rays.

PubMed

Smith, Elizabeth A; Cinquin, Bertrand P; Do, Myan; McDermott, Gerry; Le Gros, Mark A; Larabell, Carolyn A

2014-08-01

Correlated imaging is the process of imaging a specimen with two complementary modalities, and then combining the two data sets to create a highly informative, composite view. A recent implementation of this concept has been the combination of soft x-ray tomography (SXT) with fluorescence cryogenic microscopy (FCM). SXT-FCM is used to visualize cells that are held in a near-native, cryopreserved. The resultant images are, therefore, highly representative of both the cellular architecture and molecular organization in vivo. SXT quantitatively visualizes the cell and sub-cellular structures; FCM images the spatial distribution of fluorescently labeled molecules. Here, we review the characteristics of SXT-FCM, and briefly discuss how this method compares with existing correlative imaging techniques. We also describe how the incorporation of a cryo-rotation stage into a cryogenic fluorescence microscope allows acquisition of fluorescence cryogenic tomography (FCT) data. FCT is optimally suited for correlation with SXT, since both techniques image the specimen in 3-D, potentially with similar, isotropic spatial resolution. © 2013 Elsevier B.V. All rights reserved.

Multiple regression equations modelling of groundwater of Ajmer-Pushkar railway line region, Rajasthan (India).

PubMed

Mathur, Praveen; Sharma, Sarita; Soni, Bhupendra

2010-01-01

In the present work, an attempt is made to formulate multiple regression equations using all possible regressions method for groundwater quality assessment of Ajmer-Pushkar railway line region in pre- and post-monsoon seasons. Correlation studies revealed the existence of linear relationships (r 0.7) for electrical conductivity (EC), total hardness (TH) and total dissolved solids (TDS) with other water quality parameters. The highest correlation was found between EC and TDS (r = 0.973). EC showed highly significant positive correlation with Na, K, Cl, TDS and total solids (TS). TH showed highest correlation with Ca and Mg. TDS showed significant correlation with Na, K, SO4, PO4 and Cl. The study indicated that most of the contamination present was water soluble or ionic in nature. Mg was present as MgCl2; K mainly as KCl and K2SO4, and Na was present as the salts of Cl, SO4 and PO4. On the other hand, F and NO3 showed no significant correlations. The r2 values and F values (at 95% confidence limit, alpha = 0.05) for the modelled equations indicated high degree of linearity among independent and dependent variables. Also the error % between calculated and experimental values was contained within +/- 15% limit.

Instability of Longitudinal Wave in Magnetized Strongly Coupled Dusty Plasma

NASA Astrophysics Data System (ADS)

Xie, Bai-Song

2003-12-01

Instability of longitudinal wave in magnetized strongly coupled dusty plasmas is investigated. The dust charging relaxation is taken into account. It is found that there exists threshold of interdust distance for the instability of wave, which is determined significantly by the dust charging relaxation, the coupling parameter of high correlation of dust as well the strength of magnetic field.

Linking Resource Allocation to Student Achievement: A Study of Title 1 and Title 1 Stimulus Utilization

ERIC Educational Resources Information Center

Krumpe, Kati P.

2012-01-01

With the emphasis on high standards and fiscal accountability, there is a heightened need to inform the research linking student achievement to the allocation of resources. This mixed methods inquiry sought to study how schools utilized Title 1 and Title 1 stimulus funding from 2009-2011 to determine if correlations existed between areas of…

Public release of the ISC-GEM Global Instrumental Earthquake Catalogue (1900-2009)

USGS Publications Warehouse

Storchak, Dmitry A.; Di Giacomo, Domenico; Bondára, István; Engdahl, E. Robert; Harris, James; Lee, William H.K.; Villaseñor, Antonio; Bormann, Peter

2013-01-01

The International Seismological Centre–Global Earthquake Model (ISC–GEM) Global Instrumental Earthquake Catalogue (1900–2009) is the result of a special effort to substantially extend and improve currently existing global catalogs to serve the requirements of specific user groups who assess and model seismic hazard and risk. The data from the ISC–GEM Catalogue would be used worldwide yet will prove absolutely essential in those regions where a high seismicity level strongly correlates with a high population density.

Doppler ultrasound study of penis in men with systemic sclerosis: a correlation with Doppler indices of renal and digital arteries.

PubMed

Rosato, E; Barbano, B; Gigante, A; Cianci, R; Molinaro, I; Quarta, S; Digiulio, M A; Messineo, D; Pisarri, S; Salsano, F

2013-01-01

Erectile dysfunction (ED) prevalence in male systemic sclerosis (SSc) is high and its pathogenesis is unclear. The aim of the study is to assess correlation between Doppler ultrasound indices of penis and kidneys or digital arteries in male systemic sclerosis. Fourteen men with systemic sclerosis were enrolled in this study. Erectile function was investigated by the International Index of Erectile Function-5. Peak systolic velocity, end diastolic velocity, resistive index, pulsative index, and systolic/diastolic ratio were measured on the cavernous arteries at the peno-scrotal junction in the flaccid state, on the interlobar artery of both kidneys and all ten proper palmar digital arteries. Ten (71 percent) patients have an International Index of Erectile Function-5 less than 21. Reduction of penis peak systolic velocity was observed in all SSc subjects. Doppler indices of cavernous arteries correlate with the International Index of Erectile Function-5. The renal and digital arteries resistive index demonstrated a good correlation (p less than 0.0001) with International Index of Erectile Function-5. A positive correlation exists between penis and kidney arteries Doppler indices: end diastolic velocity (p less than 0.05, r=0.54), resistive index (p less than 0.0001, r=0.90), systolic/diastolic ratio (p less than 0.01, r=0.69). A positive correlation was observed between penis and digital arteries Doppler indices: peak systolic velocity (p less than 0.01, r=0.68), end diastolic velocity (p less than 0.01, r=0.75), resistive index (p less than 0.001, r=0.79), systolic/diastolic ratio (p less than 0.05, r=0.59). A correlation exists between arterial impairment of penis and renal or digital arteries.

Examination of Liquid Fluoride Salt Heat Transfer

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

Yoder Jr, Graydon L

2014-01-01

The need for high efficiency power conversion and energy transport systems is increasing as world energy use continues to increase, petroleum supplies decrease, and global warming concerns become more prevalent. There are few heat transport fluids capable of operating above about 600oC that do not require operation at extremely high pressures. Liquid fluoride salts are an exception to that limitation. Fluoride salts have very high boiling points, can operate at high temperatures and low pressures and have very good heat transfer properties. They have been proposed as coolants for next generation fission reactor systems, as coolants for fusion reactor blankets,more » and as thermal storage media for solar power systems. In each case, these salts are used to either extract or deliver heat through heat exchange equipment, and in order to design this equipment, liquid salt heat transfer must be predicted. This paper discusses the heat transfer characteristics of liquid fluoride salts. Historically, heat transfer in fluoride salts has been assumed to be consistent with that of conventional fluids (air, water, etc.), and correlations used for predicting heat transfer performance of all fluoride salts have been the same or similar to those used for water conventional fluids an, water, etc). A review of existing liquid salt heat transfer data is presented, summarized, and evaluated on a consistent basis. Less than 10 experimental data sets have been found in the literature, with varying degrees of experimental detail and measured parameters provided. The data has been digitized and a limited database has been assembled and compared to existing heat transfer correlations. Results vary as well, with some data sets following traditional correlations; in others the comparisons are less conclusive. This is especially the case for less common salt/materials combinations, and suggests that additional heat transfer data may be needed when using specific salt eutectics in heat transfer equipment designs. All of the data discussed above were taken under forced convective conditions (both laminar and turbulent). Some recent data taken at ORNL under free convection conditions are also presented and results discussed. This data was taken using a simple crucible experiment with an instrumented nickel heater inserted in the salt to induce natural circulation within the crucible. The data was taken over a temperature range of 550oC to 650oC in FLiNaK salt. This data covers both laminar and turbulent natural convection conditions, and is compared to existing forms of natural circulation correlations.« less

Returners and explorers dichotomy in human mobility

PubMed Central

Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

2015-01-01

The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

Bronchiectasis: correlation of high-resolution CT findings with health-related quality of life.

PubMed

Eshed, I; Minski, I; Katz, R; Jones, P W; Priel, I E

2007-02-01

To evaluate the relationship between the severity of bronchiectatic diseases, as evident on high-resolution computed tomography (HRCT) and the patient's quality of life measured using the St George's Respiratory Questionnaire (SGRQ). Forty-six patients (25 women, 21 men, mean age: 63 years) with bronchiectatic disease as evident on recent HRCT examinations were recruited. Each patient completed the SGRQ and underwent respiratory function tests. HRCT findings were blindly and independently scored by two radiologists, using the modified Bhalla scoring system. The relationships between HRCT scores, SGRQ scores and pulmonary function tests were evaluated. The patients' total CT score did not correlate with the SGRQ scores. However, patients with more advanced disease on HRCT, significantly differed in their SGRQ scores from patients with milder bronchiectatic disease. A significant correlation was found between the CT scores for the middle and distal lung zones and the activity, impacts and total SGRQ scores. No correlation was found between CT scores and respiratory function test indices. However, a significant correlation was found between the SGRQ scores and most of the respiratory function test indices. A correlation between the severity of bronchiectatic disease as expressed in HRCT and the health-related quality of life exists in patients with a more severe bronchiectatic disease but not in patients with mild disease. Such correlation depends on the location of the bronchiectasis in the pulmonary tree.

Nonlinear information fusion algorithms for data-efficient multi-fidelity modelling.

PubMed

Perdikaris, P; Raissi, M; Damianou, A; Lawrence, N D; Karniadakis, G E

2017-02-01

Multi-fidelity modelling enables accurate inference of quantities of interest by synergistically combining realizations of low-cost/low-fidelity models with a small set of high-fidelity observations. This is particularly effective when the low- and high-fidelity models exhibit strong correlations, and can lead to significant computational gains over approaches that solely rely on high-fidelity models. However, in many cases of practical interest, low-fidelity models can only be well correlated to their high-fidelity counterparts for a specific range of input parameters, and potentially return wrong trends and erroneous predictions if probed outside of their validity regime. Here we put forth a probabilistic framework based on Gaussian process regression and nonlinear autoregressive schemes that is capable of learning complex nonlinear and space-dependent cross-correlations between models of variable fidelity, and can effectively safeguard against low-fidelity models that provide wrong trends. This introduces a new class of multi-fidelity information fusion algorithms that provide a fundamental extension to the existing linear autoregressive methodologies, while still maintaining the same algorithmic complexity and overall computational cost. The performance of the proposed methods is tested in several benchmark problems involving both synthetic and real multi-fidelity datasets from computational fluid dynamics simulations.

A new system for assessment of growth using mandibular canine calcification stages and its correlation with modified MP3 stages.

PubMed

Hegde, Gautham; Hegde, Nanditha; Kumar, Anil; Keshavaraj

2014-07-01

Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. A total of 160 periapical radiographs, of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. The correlation coefficient between MP3 stages and developmental stages of mandibular canine was found to be significant in both male and female groups. When the canine calcification stages were compared with the MP3 stages it was found that with the exception of the D stage of canine calcification the remaining stages showed a very high correlation with the modified MP3 stages. The correlation between the mandibular canine calcification stages, and the MP3 stages was found to be significant. The canine calcification could be used as a sole indicator for assessment of skeletal maturity.

Assessment of Growth Using Mandibular Canine Calcification Stages and Its Correlation with Modified MP3 Stages.

PubMed

Nayak, Reshma; Nayak, Us Krishna; Hegde, Gautam

2010-01-01

Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. A total of 160 periapical radiographs (80 males and 80 females), of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. The correlation between the developmental stages of MP3 and the mandibular right canine in male and female groups, is of high statistical significance (p = 0.001). The correlation coefficient between MP3 stages and developmental stages of mandibular canine and chronological age in male and females was found to be not significant. The correlation between the mandibular canine calcification stages and MP3 stages was found to be significant. The developmental stages of the mandibular canine could be used very reliably as a sole indicator for assessment of skeletal maturity.

Female acceleration tolerance: effects of menstrual state and physical condition.

PubMed

Heaps, C L; Fischer, M D; Hill, R C

1997-06-01

The literature contains a paucity of information on female tolerance to high sustained acceleration. With women now flying high-performance aircraft, gender-specific factors that may affect female acceleration tolerance have become increasingly important. The purpose of this investigation was to determine how menstrual state and physical condition affect acceleration tolerance. We hypothesized the menstrual cycle would have no effect on acceleration tolerance and that a positive correlation would exist between physical fitness level and tolerance to high sustained acceleration. Centrifuge exposures on 8 female subjects consisted of a relaxed gradual-onset run (0.1 G.s-1) to the visual endpoint, a rapid-onset run (6 G.s-1) to +5 GZ for 15 s, and a +4.5 to +7 GZ simulated aerial combat maneuver (SACM) to physical exhaustion. Acceleration tolerance data were collected at onset of menstruation and 1, 2 and 3 weeks following the onset for two complete menstrual cycles. On separate days, body composition, anaerobic power output and peak oxygen uptake were determined. Retrospective data from 10 male subjects who had performed the +4.5 to +7 GZ SACM were analyzed and compared to these data. Analysis of variance revealed no significant difference in relaxed tolerance or SACM duration between the four selected menstrual cycle time points. Time-to-fatigue on the +4.5 to +7 GZ SACM was positively (p < or = 0.05) correlated with absolute fat-free mass (r = 0.87) and anaerobic power production (r = 0.76) in female subjects. However, when these variables were adjusted for total body mass, the significant correlations no longer existed. No correlation was found between SACM duration and absolute (L min-1) nor relative (ml.kg-1.min-1) aerobic fitness. Time-to-fatigue during the SACM was not significantly different between male and female subjects (250 +/- 97 and 246 +/- 149 s, respectively).

Geomorphic Evidence for Martian Ground Ice and Climate Change

NASA Technical Reports Server (NTRS)

Kanner, L. C.; Allen, C. C.; Bell, M. S.

2004-01-01

Recent results from gamma-ray and neutron spectrometers on Mars Odyssey indicate the presence of a hydrogen-rich layer tens of centimeters thick in the uppermost meter in high latitudes (greater than 60) on Mars. This hydrogen-rich layer correlates to regions of ice stability. Thus, the subsurface hydrogen is thought to be water ice constituting 35 plus or minus 15% by weight near the north and south polar regions. We refine the location of subsurface ice deposits at a less than km scale by combining existing spectroscopy data with surface features indicative of subsurface ice. A positive correlation between spectroscopy data and geomorphic ice indicators has been previously suggested for high latitudes. Here we expand the comparative study to northern mid latitudes (30 degrees N- 65 degrees N).

Converting positive and negative symptom scores between PANSS and SAPS/SANS.

PubMed

van Erp, Theo G M; Preda, Adrian; Nguyen, Dana; Faziola, Lawrence; Turner, Jessica; Bustillo, Juan; Belger, Aysenil; Lim, Kelvin O; McEwen, Sarah; Voyvodic, James; Mathalon, Daniel H; Ford, Judith; Potkin, Steven G; Fbirn

2014-01-01

The Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), and the Positive and Negative Syndrome Scale for Schizophrenia (PANSS) are the most widely used schizophrenia symptom rating scales, but despite their co-existence for 25 years no easily usable between-scale conversion mechanism exists. The aim of this study was to provide equations for between-scale symptom rating conversions. Two-hundred-and-five schizophrenia patients [mean age±SD=39.5±11.6, 156 males] were assessed with the SANS, SAPS, and PANSS. Pearson's correlations between symptom scores from each of the scales were computed. Linear regression analyses, on data from 176 randomly selected patients, were performed to derive equations for converting ratings between the scales. Intraclass correlations, on data from the remaining 29 patients, not part of the regression analyses, were performed to determine rating conversion accuracy. Between-scale positive and negative symptom ratings were highly correlated. Intraclass correlations between the original positive and negative symptom ratings and those obtained via conversion of alternative ratings using the conversion equations were moderate to high (ICCs=0.65 to 0.91). Regression-based equations may be useful for conversion between schizophrenia symptom severity as measured by the SANS/SAPS and PANSS, though additional validation is warranted. This study's conversion equations, implemented at http:/converteasy.org, may aid in the comparison of medication efficacy studies, in meta- and mega-analyses examining symptoms as moderator variables, and in retrospective combination of symptom data in multi-center data sharing projects that need to pool symptom rating data when such data are obtained using different scales. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of Measures to Assess Personal Recovery in Young People Treated in Specialist Mental Health Services.

PubMed

John, Mary; Jeffries, Fiona W; Acuna-Rivera, Marcela; Warren, Fiona; Simonds, Laura M

2015-01-01

Recovery has become a central concept in mental health service delivery, and several recovery-focused measures exist for adults. The concept's applicability to young people's mental health experience has been neglected, and no measures yet exist. Aim The aim of this work is to develop measures of recovery for use in specialist child and adolescent mental health services. On the basis of 21 semi-structured interviews, three recovery measures were devised, one for completion by the young person and two for completion by the parent/carer. Two parent/carer measures were devised in order to assess both their perspective on their child's recovery and their own recovery process. The questionnaires were administered to a UK sample of 47 young people (10-18 years old) with anxiety and depression and their parents, along with a measure used to routinely assess treatment progress and outcome and a measure of self-esteem. All three measures had high internal consistency (alpha ≥ 0.89). Young people's recovery scores were correlated negatively with scores on a measure used to routinely assess treatment progress and outcome (r = -0.75) and positively with self-esteem (r = 0.84). Parent and young persons' reports of the young person's recovery were positively correlated (r = 0.61). Parent report of the young person's recovery and of their own recovery process were positively correlated (r = 0.75). The three measures have the potential to be used in mental health services to assess recovery processes in young people with mental health difficulties and correspondence with symptomatic improvement. The measures provide a novel way of capturing the parental/caregiver perspective on recovery and caregivers' own wellbeing. No tools exist to evaluate recovery-relevant processes in young people treated in specialist mental health services. This study reports on the development and psychometric evaluation of three self-report recovery-relevant assessments for young people and their caregivers. Findings indicate a high degree of correspondence between young person and caregiver reports of recovery in the former. The recovery assessments correlate inversely with a standardized symptom-focused measure and positively with self-esteem. Copyright © 2014 John Wiley & Sons, Ltd.

The Variables Associated With Health Promotion Behaviors Among Urban Black Women.

PubMed

Hepburn, Millie

2018-04-24

To improve understanding of variables impacting health promotion behaviors among urban Black women. A cross-sectional survey was used. Urban Black women (N = 132) between the ages of 30 to 64 years participated. The study was conducted in a U.S. metropolitan region in 2015. Health literacy (Newest Vital Sign [NVS]), self-efficacy (New General Self-Efficacy Scale [NGSE]), and readiness for change (Health Risk Instrument [HRI]) were correlated with health promotion behaviors (Health Promotion Lifestyle Profile II [HPLPII]). Univariate statistics addressed demographic characteristics; bivariate/simultaneous linear regression determined the relationships between the NVS, NGSE, and HRI to health promotion behaviors (HPLPII). Demographics: 72.6% completed high school and 25% completed college, and the mean body mass index (BMI) was >32. Positive correlations existed between each variable to health promotion behaviors: NVS (r = .244, p < .002), NGSE (r = .312, p < .001), HRI (r = .440, p < .001), and accounted for 29.8% of variances in health promotion behaviors. Education and health literacy were also correlated (r s = .414, p = .001). Although health literacy, self-efficacy, and readiness for change are associated with health promotion behaviors, readiness for change was the most highly correlated. The development and incorporation of interventions to promote health promotion behaviors should include readiness for change, health literacy, BMI, and education, especially among urban Black women in order to reduce critical health disparities. Community-based and culturally relevant strategies in promoting health that are integrated into existing lifestyles and designed to impact readiness for change will have the greatest impact on reducing health disparities both in the United States and in countries experiencing rapid urbanization. For example, healthy eating behaviors or increased physical activity may be best adopted when integrated into existing community-based spiritual or cultural events via trusted community leaders. Replication of this study in other populations of Black women will improve the generalizability of this study, both in the United States and globally. However, the addition of other demographic variables, such as a history of chronic conditions, military service, domestic or other violence, spirituality, and the availability of community resources, would strengthen the results in future studies. © 2018 Sigma Theta Tau International.

Noise Intensity-Intensity Correlations and the Fourth Cumulant of Photo-assisted Shot Noise

NASA Astrophysics Data System (ADS)

Forgues, Jean-Charles; Sane, Fatou Bintou; Blanchard, Simon; Spietz, Lafe; Lupien, Christian; Reulet, Bertrand

2013-10-01

We report the measurement of the fourth cumulant of current fluctuations in a tunnel junction under both dc and ac (microwave) excitation. This probes the non-Gaussian character of photo-assisted shot noise. Our measurement reveals the existence of correlations between noise power measured at two different frequencies, which corresponds to two-mode intensity correlations in optics. We observe positive correlations, i.e. photon bunching, which exist only for certain relations between the excitation frequency and the two detection frequencies, depending on the dc bias of the sample.

Ergodic channel capacity of spatial correlated multiple-input multiple-output free space optical links using multipulse pulse-position modulation

NASA Astrophysics Data System (ADS)

Wang, Huiqin; Wang, Xue; Cao, Minghua

2017-02-01

The spatial correlation extensively exists in the multiple-input multiple-output (MIMO) free space optical (FSO) communication systems due to the channel fading and the antenna space limitation. Wilkinson's method was utilized to investigate the impact of spatial correlation on the MIMO FSO communication system employing multipulse pulse-position modulation. Simulation results show that the existence of spatial correlation reduces the ergodic channel capacity, and the reception diversity is more competent to resist this kind of performance degradation.

IOD and ENSO impacts on the extreme stream-flows of Citarum river in Indonesia

NASA Astrophysics Data System (ADS)

Sahu, Netrananda; Behera, Swadhin K.; Yamashiki, Yosuke; Takara, Kaoru; Yamagata, Toshio

2012-10-01

Extreme stream-flow events of Citarum River are derived from the daily stream-flows at the Nanjung gauge station. Those events are identified based on their persistently extreme flows for 6 or more days during boreal fall when the seasonal mean stream-flow starts peaking-up from the lowest seasonal flows of June-August. Most of the extreme events of high-streamflows were related to La Niña conditions of tropical Pacific. A few of them were also associated with the negative phases of IOD and the newly identified El Niño Modoki. Unlike the cases of extreme high streamflows, extreme low streamflow events are seen to be associated with the positive IODs. Nevertheless, it was also found that the low-stream-flow events related to positive IOD events were also associated with El Niño events except for one independent event of 1977. Because the occurrence season coincides the peak season of IOD, not only the picked extreme events are seen to fall under the IOD seasons but also there exists a statistically significant correlation of 0.51 between the seasonal IOD index and the seasonal streamflows. There also exists a significant lag correlation when IOD of June-August season leads the streamflows of September-November. A significant but lower correlation coefficient (0.39) is also found between the seasonal streamflow and El Niño for September-November season only.

Evaluation of land performance in Senegal using multi-temporal NDVI and rainfall series

USGS Publications Warehouse

Li, Ji; Lewis, J.; Rowland, James; Tappan, G.; Tieszen, L.L.

2004-01-01

Time series of rainfall data and normalized difference vegetation index (NDVI) were used to evaluate land cover performance in Senegal, Africa, for the period 1982–1997, including analysis of woodland/forest, agriculture, savanna, and steppe land cover types. A strong relationship exists between annual rainfall and season-integrated NDVI for all of Senegal (r=0.74 to 0.90). For agriculture, savanna, and steppe areas, high positive correlations portray ‘normal’ land cover performance in relation to the rainfall/NDVI association. Regions of low correlation might indicate areas impacted by human influence. However, in the woodland/forest area, a negative or low correlation (with high NDVI) may reflect ‘normal’ land cover performance, due in part to the saturation effect of the rainfall/NDVI association. The analysis identified three areas of poor performance, where degradation has occurred over many years. Use of the ‘Standard Error of the Estimate’ provided essential information for detecting spatial anomalies associated with land degradation.

Structure of health-enhancing behavior in adolescence: a latent-variable approach.

PubMed

Donovan, J E; Jessor, R; Costa, F M

1993-12-01

The structure of the interrelations among a variety of health-enhancing behaviors was examined using structural equation modeling analyses of questionnaire data from 1,280 middle school students and 2,219 high school students. The health-enhancing behaviors included seat belt use, adequate hours of sleep, attention to healthy diet, adequate exercise, low sedentary behavior, and regular toothbrushing. In the middle school sample, all of the health-enhancing behaviors correlated significantly but modestly with each other, except for sleep with toothbrushing. In the high school sample, all but three of the 15 correlations among the behaviors were significant. The results further show that a single underlying factor can account for the modest correlations among these health-enhancing behaviors in both samples. The generality of the single-factor model was also established for male, female, White, Hispanic, and Black students at each school level. These findings provide some support for the existence of health-related lifestyles in adolescence.

The Dark Matter Crisis: Falsification of the Current Standard Model of Cosmology

NASA Astrophysics Data System (ADS)

Kroupa, P.

2012-06-01

The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. Type A dwarfs surround the host approximately spherically, while type B dwarfs are typically correlated in phase-space. Type B dwarfs must exist in any cosmological theory in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. The Milky Way satellite system forms a vast phase-space-correlated structure that includes globular clusters and stellar and gaseous streams. Other galaxies also have phase-space correlated satellite systems. Therefore, The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations. Other theoretical solutions to cosmological observations exist. In particular, alone the empirical mass-discrepancy-acceleration correlation constitutes convincing evidence that galactic-scale dynamics must be Milgromian. Major problems with inflationary big bang cosmologies remain unresolved.

Influences of Neural Pathway Integrity on Children's Response to Reading Instruction

PubMed Central

Davis, Nicole; Fan, Qiuyun; Compton, Donald L.; Fuchs, Doug; Fuchs, Lynn S.; Cutting, Laurie E.; Gore, John C.; Anderson, Adam W.

2010-01-01

As the education field moves toward using responsiveness to intervention to identify students with disabilities, an important question is the degree to which this classification can be connected to a student's neurobiological characteristics. A few functional neuroimaging studies have reported a relationship between activation and response to instruction; however, whether a similar correlation exists with white matter (WM) is not clear. To investigate this issue, we acquired high angular resolution diffusion images from a group of first grade children who differed in their levels of responsiveness to a year-long reading intervention. Using probabilistic tractography, we calculated the strength of WM connections among nine cortical regions of interest and correlated these estimates with participants’ scores on four standardized reading measures. We found eight significant correlations, four of which were connections between the insular cortex and angular gyrus. In each of the correlations, a relationship with children's response to intervention was evident. PMID:21088707

Regional beach/cliff system dynamics along the california coast

USGS Publications Warehouse

Hapke, C.J.; Reid, Don

2007-01-01

The coast of California is comprised of both sandy shorelines and cliffed coastline, and in many areas these features spatially coincide. In order to better understand the regional trends of change along the California coast, the U.S. Geological Survey is quantifying both sandy shoreline change and coastal cliff retreat for the state. The resulting database was used to examine the dynamics of the beach/cliff system. We found inconsistent evidence of a relationship between rates of cliff retreat and shoreline change on the spatial scale of 100-km cells. However, when the data are correlated within individual regions, a strong relationship exists between the geomorphology of the coast and the behavior of the beach/cliff system. Areas of high-relief coast show negative correlations, indicating that higher rates of cliff retreat correlate with lower rates of shoreline erosion. In contrast, low- to moderate-relief coasts show strong positive correlations.

NO RELATIONSHIP BETWEEN INTELLIGENCE AND FACIAL ATTRACTIVENESS IN A LARGE, GENETICALLY INFORMATIVE SAMPLE

PubMed Central

Mitchem, Dorian G.; Zietsch, Brendan P.; Wright, Margaret J.; Martin, Nicholas G.; Hewitt, John K.; Keller, Matthew C.

2015-01-01

Theories in both evolutionary and social psychology suggest that a positive correlation should exist between facial attractiveness and general intelligence, and several empirical observations appear to corroborate this expectation. Using highly reliable measures of facial attractiveness and IQ in a large sample of identical and fraternal twins and their siblings, we found no evidence for a phenotypic correlation between these traits. Likewise, neither the genetic nor the environmental latent factor correlations were statistically significant. We supplemented our analyses of new data with a simple meta-analysis that found evidence of publication bias among past studies of the relationship between facial attractiveness and intelligence. In view of these results, we suggest that previously published reports may have overestimated the strength of the relationship and that the theoretical bases for the predicted attractiveness-intelligence correlation may need to be reconsidered. PMID:25937789

On an additive partial correlation operator and nonparametric estimation of graphical models.

PubMed

Lee, Kuang-Yao; Li, Bing; Zhao, Hongyu

2016-09-01

We introduce an additive partial correlation operator as an extension of partial correlation to the nonlinear setting, and use it to develop a new estimator for nonparametric graphical models. Our graphical models are based on additive conditional independence, a statistical relation that captures the spirit of conditional independence without having to resort to high-dimensional kernels for its estimation. The additive partial correlation operator completely characterizes additive conditional independence, and has the additional advantage of putting marginal variation on appropriate scales when evaluating interdependence, which leads to more accurate statistical inference. We establish the consistency of the proposed estimator. Through simulation experiments and analysis of the DREAM4 Challenge dataset, we demonstrate that our method performs better than existing methods in cases where the Gaussian or copula Gaussian assumption does not hold, and that a more appropriate scaling for our method further enhances its performance.

On an additive partial correlation operator and nonparametric estimation of graphical models

PubMed Central

Li, Bing; Zhao, Hongyu

2016-01-01

Abstract We introduce an additive partial correlation operator as an extension of partial correlation to the nonlinear setting, and use it to develop a new estimator for nonparametric graphical models. Our graphical models are based on additive conditional independence, a statistical relation that captures the spirit of conditional independence without having to resort to high-dimensional kernels for its estimation. The additive partial correlation operator completely characterizes additive conditional independence, and has the additional advantage of putting marginal variation on appropriate scales when evaluating interdependence, which leads to more accurate statistical inference. We establish the consistency of the proposed estimator. Through simulation experiments and analysis of the DREAM4 Challenge dataset, we demonstrate that our method performs better than existing methods in cases where the Gaussian or copula Gaussian assumption does not hold, and that a more appropriate scaling for our method further enhances its performance. PMID:29422689

Animal versus human oral drug bioavailability: Do they correlate?

PubMed Central

Musther, Helen; Olivares-Morales, Andrés; Hatley, Oliver J.D.; Liu, Bo; Rostami Hodjegan, Amin

2014-01-01

Oral bioavailability is a key consideration in development of drug products, and the use of preclinical species in predicting bioavailability in human has long been debated. In order to clarify whether any correlation between human and animal bioavailability exist, an extensive analysis of the published literature data was conducted. Due to the complex nature of bioavailability calculations inclusion criteria were applied to ensure integrity of the data. A database of 184 compounds was assembled. Linear regression for the reported compounds indicated no strong or predictive correlations to human data for all species, individually and combined. The lack of correlation in this extended dataset highlights that animal bioavailability is not quantitatively predictive of bioavailability in human. Although qualitative (high/low bioavailability) indications might be possible, models taking into account species-specific factors that may affect bioavailability are recommended for developing quantitative prediction. PMID:23988844

Joint demosaicking and zooming using moderate spectral correlation and consistent edge map

NASA Astrophysics Data System (ADS)

Zhou, Dengwen; Dong, Weiming; Chen, Wengang

2014-07-01

The recently published joint demosaicking and zooming algorithms for single-sensor digital cameras all overfit the popular Kodak test images, which have been found to have higher spectral correlation than typical color images. Their performance perhaps significantly degrades on other datasets, such as the McMaster test images, which have weak spectral correlation. A new joint demosaicking and zooming algorithm is proposed for the Bayer color filter array (CFA) pattern, in which the edge direction information (edge map) extracted from the raw CFA data is consistently used in demosaicking and zooming. It also moderately utilizes the spectral correlation between color planes. The experimental results confirm that the proposed algorithm produces an excellent performance on both the Kodak and McMaster datasets in terms of both subjective and objective measures. Our algorithm also has high computational efficiency. It provides a better tradeoff among adaptability, performance, and computational cost compared to the existing algorithms.

A Study of Effects of MultiCollinearity in the Multivariable Analysis

PubMed Central

Yoo, Wonsuk; Mayberry, Robert; Bae, Sejong; Singh, Karan; (Peter) He, Qinghua; Lillard, James W.

2015-01-01

A multivariable analysis is the most popular approach when investigating associations between risk factors and disease. However, efficiency of multivariable analysis highly depends on correlation structure among predictive variables. When the covariates in the model are not independent one another, collinearity/multicollinearity problems arise in the analysis, which leads to biased estimation. This work aims to perform a simulation study with various scenarios of different collinearity structures to investigate the effects of collinearity under various correlation structures amongst predictive and explanatory variables and to compare these results with existing guidelines to decide harmful collinearity. Three correlation scenarios among predictor variables are considered: (1) bivariate collinear structure as the most simple collinearity case, (2) multivariate collinear structure where an explanatory variable is correlated with two other covariates, (3) a more realistic scenario when an independent variable can be expressed by various functions including the other variables. PMID:25664257

A Study of Effects of MultiCollinearity in the Multivariable Analysis.

PubMed

Yoo, Wonsuk; Mayberry, Robert; Bae, Sejong; Singh, Karan; Peter He, Qinghua; Lillard, James W

2014-10-01

A multivariable analysis is the most popular approach when investigating associations between risk factors and disease. However, efficiency of multivariable analysis highly depends on correlation structure among predictive variables. When the covariates in the model are not independent one another, collinearity/multicollinearity problems arise in the analysis, which leads to biased estimation. This work aims to perform a simulation study with various scenarios of different collinearity structures to investigate the effects of collinearity under various correlation structures amongst predictive and explanatory variables and to compare these results with existing guidelines to decide harmful collinearity. Three correlation scenarios among predictor variables are considered: (1) bivariate collinear structure as the most simple collinearity case, (2) multivariate collinear structure where an explanatory variable is correlated with two other covariates, (3) a more realistic scenario when an independent variable can be expressed by various functions including the other variables.

Stomach cancer in 67 Chinese counties: evidence of interaction between salt consumption and helicobacter pylori infection.

PubMed

Wang, Xiaoqin; Terry, Paul; Yan, Hong

2008-01-01

To examine the interaction between salt-intake and helicobacter pylori (H. pylori) infection in the development of stomach cancer in an ecological study of 67 Chinese rural counties. Stomach cancer mortality data of 67 counties were derived from a national survey conducted in China between 1986 and 1988. Information regarding the prevalence of H. pylori infection and urinary sodium excretion were collected from the same individuals during a subsequent dietary survey in 1989. In these 67 counties, H. pylori prevalence and urinary sodium were correlated with stomach cancer mortality, with r=0.31 (p=0.01) and r=0.28 (p=0.03), respectively. After stratification, the significant correlation between H. pylori prevalence and stomach cancer mortality only existed in counties with high levels (> or =5.0 mg/mg creatinine/12-hour) of urinary sodium (r=0.5; p=0.002). Similarly, the significant correlation between urinary sodium and stomach cancer mortality was only presented in counties with high (> or =71.6%) H. pylori prevalence (r=0.4; p=0.017). Multivariate regression analysis showed results consistent with the correlation analysis. These findings suggest that there may be an interaction between high salt consumption and H .pylori infection in the development of stomach cancer. Corroborating data from epidemiological, clinical, and experimental studies are needed.

An assessment of hair cortisol among postpartum Brazilian mothers and infants from a high-risk community in São Paulo: Intra-individual stability and association in mother-infant dyads.

PubMed

Liu, Cindy H; Fink, Günther; Brentani, Helena; Brentani, Alexandra

2017-11-01

This study examined maternal-infant synchrony of hair cortisol at 12 months after birth and the intra-individual stability of maternal hair cortisol in the postpartum period. Participants were selected from an ongoing São Paulo birth cohort project, where families are considered to be "high-risk" due to their chronic stress experiences, with the majority living in slums (favelas). Cortisol was collected through 3-cm segments of hair samples, with values representing approximate levels of cortisol from 9 to 12 months for mothers and children and 6 to 12 months for mothers. Maternal and infant cortisol values reflecting chronic stress 9-12 months after birth were highly correlated (r = .61, p < .001); earlier maternal cortisol levels (6-9 months) and child cortisol levels at 9-12 months (r = .51, p < .001) were also correlated. Maternal cortisol values showed stability over time (r = .79, p < .001). These maternal-infant correlations are high compared to the existing literature on hair cortisol in other mother-child dyads, suggesting stronger synchrony under high-risk contexts where families are faced with challenging circumstances. © 2017 Wiley Periodicals, Inc.

Evaluating reproducibility of differential expression discoveries in microarray studies by considering correlated molecular changes.

PubMed

Zhang, Min; Zhang, Lin; Zou, Jinfeng; Yao, Chen; Xiao, Hui; Liu, Qing; Wang, Jing; Wang, Dong; Wang, Chenguang; Guo, Zheng

2009-07-01

According to current consistency metrics such as percentage of overlapping genes (POG), lists of differentially expressed genes (DEGs) detected from different microarray studies for a complex disease are often highly inconsistent. This irreproducibility problem also exists in other high-throughput post-genomic areas such as proteomics and metabolism. A complex disease is often characterized with many coordinated molecular changes, which should be considered when evaluating the reproducibility of discovery lists from different studies. We proposed metrics percentage of overlapping genes-related (POGR) and normalized POGR (nPOGR) to evaluate the consistency between two DEG lists for a complex disease, considering correlated molecular changes rather than only counting gene overlaps between the lists. Based on microarray datasets of three diseases, we showed that though the POG scores for DEG lists from different studies for each disease are extremely low, the POGR and nPOGR scores can be rather high, suggesting that the apparently inconsistent DEG lists may be highly reproducible in the sense that they are actually significantly correlated. Observing different discovery results for a disease by the POGR and nPOGR scores will obviously reduce the uncertainty of the microarray studies. The proposed metrics could also be applicable in many other high-throughput post-genomic areas.

A Ranking Approach to Genomic Selection.

PubMed

Blondel, Mathieu; Onogi, Akio; Iwata, Hiroyoshi; Ueda, Naonori

2015-01-01

Genomic selection (GS) is a recent selective breeding method which uses predictive models based on whole-genome molecular markers. Until now, existing studies formulated GS as the problem of modeling an individual's breeding value for a particular trait of interest, i.e., as a regression problem. To assess predictive accuracy of the model, the Pearson correlation between observed and predicted trait values was used. In this paper, we propose to formulate GS as the problem of ranking individuals according to their breeding value. Our proposed framework allows us to employ machine learning methods for ranking which had previously not been considered in the GS literature. To assess ranking accuracy of a model, we introduce a new measure originating from the information retrieval literature called normalized discounted cumulative gain (NDCG). NDCG rewards more strongly models which assign a high rank to individuals with high breeding value. Therefore, NDCG reflects a prerequisite objective in selective breeding: accurate selection of individuals with high breeding value. We conducted a comparison of 10 existing regression methods and 3 new ranking methods on 6 datasets, consisting of 4 plant species and 25 traits. Our experimental results suggest that tree-based ensemble methods including McRank, Random Forests and Gradient Boosting Regression Trees achieve excellent ranking accuracy. RKHS regression and RankSVM also achieve good accuracy when used with an RBF kernel. Traditional regression methods such as Bayesian lasso, wBSR and BayesC were found less suitable for ranking. Pearson correlation was found to correlate poorly with NDCG. Our study suggests two important messages. First, ranking methods are a promising research direction in GS. Second, NDCG can be a useful evaluation measure for GS.

Comparative study on long-term visibility trend and its affecting factors on both sides of the Taiwan Strait

NASA Astrophysics Data System (ADS)

Deng, Junjun; Xing, Zhenyu; Zhuang, Bingliang; Du, Ke

2014-06-01

The rapid industrial development and urbanization has lead to increasing particulate matter pollution in the Cross Taiwan Strait Region, which has significant impacts on atmospheric visibility degradation. Long-term visibility trends in five typical cities over the cross-strait region (i.e., Xiamen and Fuzhou in the Western Taiwan Strait (WTS) region and Taipei, Taichung and Tainan in Taiwan) and its correlation with air quality and meteorological conditions were investigated using visibility and meteorological data during 1973-2011 and air pollution data during 2009-2011. For the entire period, the overall average visibilities in the WTS region were better than those in Taiwan, with an average of 16.8, 16.6, 8.5, 10.3 and 9.0 km in Fuzhou, Xiamen, Taipei, Taichung and Tainan, respectively. Decline trends with decreasing rates of - 0.5-0.1 km/yr existed in all cities except Taipei, which had an improvement in visibility after 1992. All seasons had decreasing trends during the 39-year period except in Taipei. The WTS region had the worse change trend compared with Taiwan. No statistically significant weekend effect in visibility is found over the region. Visibilities were better in summer and autumn, while worse in winter and spring. Correlation analysis revealed that significant negative correlations existed between visibility and NO2 and airborne particles (i.e., PM10 and PM2.5); PM2.5 played an important role in visibility degradation. High temperature and low pressure is beneficial for better visibility. Principal component analysis further confirmed the impacts of high concentrations of air pollutants, stable synoptic systems and humid air with high relative humidity on visibility impairment. In addition, case studies highlighted characteristics and potential causes of typical regional low visibility episodes over the region.

Measuring geographical accessibility to palliative and end of life (PEoLC) related facilities: a comparative study in an area with well-developed specialist palliative care (SPC) provision.

PubMed

Pearson, Clare; Verne, Julia; Wells, Claudia; Polato, Giovanna M; Higginson, Irene J; Gao, Wei

2017-01-26

Geographical accessibility is important in accessing healthcare services. Measuring it has evolved alongside technological and data analysis advances. High correlations between different methods have been detected, but no comparisons exist in the context of palliative and end of life care (PEoLC) studies. To assess how geographical accessibility can affect PEoLC, selection of an appropriate method to capture it is crucial. We therefore aimed to compare methods of measuring geographical accessibility of decedents to PEoLC-related facilities in South London, an area with well-developed SPC provision. Individual-level death registration data in 2012 (n = 18,165), from the Office for National Statistics (ONS) were linked to area-level PEoLC-related facilities from various sources. Simple and more complex measures of geographical accessibility were calculated using the residential postcodes of the decedents and postcodes of the nearest hospital, care home and hospice. Distance measures (straight-line, travel network) and travel times along the road network were compared using geographic information system (GIS) mapping and correlation analysis (Spearman rho). Borough-level maps demonstrate similarities in geographical accessibility measures. Strong positive correlation exist between straight-line and travel distances to the nearest hospital (rho = 0.97), care home (rho = 0.94) and hospice (rho = 0.99). Travel times were also highly correlated with distance measures to the nearest hospital (rho range = 0.84-0.88), care home (rho = 0.88-0.95) and hospice (rho = 0.93-0.95). All correlations were significant at p < 0.001 level. Distance-based and travel-time measures of geographical accessibility to PEoLC-related facilities in South London are similar, suggesting the choice of measure can be based on the ease of calculation.

Variation in critical care services across North America and Western Europe.

PubMed

Wunsch, Hannah; Angus, Derek C; Harrison, David A; Collange, Olivier; Fowler, Robert; Hoste, Eric A J; de Keizer, Nicolette F; Kersten, Alexander; Linde-Zwirble, Walter T; Sandiumenge, Alberto; Rowan, Kathryn M

2008-10-01

Critical care represents a large percentage of healthcare spending in developed countries. Yet, little is known regarding international variation in critical care services. We sought to understand differences in critical care delivery by comparing data on the distribution of services in eight countries. Retrospective review of existing national administrative data. We identified sources of data in each country to provide information on acute care hospitals and beds, intensive care units and beds, intensive care admissions, and definitions of intensive care beds. Data were all referenced and from as close to 2005 as possible. United States, France, United Kingdom, Canada, Belgium, Germany, The Netherlands, and Spain. Not available. None. No standard definition existed for acute care hospital or intensive care unit beds across countries. Hospital beds varied three-fold from 221/100,000 population in the United States to 593/100,000 in Germany. Adult intensive care unit beds also ranged seven-fold from 3.3/100,000 population in the United Kingdom to 24.0/100,000 in Germany. Volume of intensive care unit admissions per year varied ten-fold from 216/100,000 population in the United Kingdom to 2353/100,000 in Germany. The ratio of intensive care unit beds to hospital beds was highly correlated across all countries except the United States (r = .90). There was minimal correlation between the number of intensive care unit beds per capita and health care spending per capita (r = .45), but high inverse correlation between intensive care unit beds and hospital mortality for intensive care unit patients across countries (r = -.82). Absolute critical care services vary dramatically between countries with wide differences in both numbers of beds and volume of admissions. The number of intensive care unit beds per capita is not strongly correlated with overall health expenditure, but does correlate strongly with mortality. These findings demonstrate the need for critical care data from all countries, as they are essential for interpretation of studies, and policy decisions regarding critical care services.

The effects of common risk factors on stock returns: A detrended cross-correlation analysis

NASA Astrophysics Data System (ADS)

Ruan, Qingsong; Yang, Bingchan

2017-10-01

In this paper, we investigate the cross-correlations between Fama and French three factors and the return of American industries on the basis of cross-correlation statistic test and multifractal detrended cross-correlation analysis (MF-DCCA). Qualitatively, we find that the return series of Fama and French three factors and American industries were overall significantly cross-correlated based on the analysis of a statistic. Quantitatively, we find that the cross-correlations between three factors and the return of American industries were strongly multifractal, and applying MF-DCCA we also investigate the cross-correlation of industry returns and residuals. We find that there exists multifractality of industry returns and residuals. The result of correlation coefficients we can verify that there exist other factors which influence the industry returns except Fama three factors.

Modeling evaporation from spent nuclear fuel storage pools: A diffusion approach

NASA Astrophysics Data System (ADS)

Hugo, Bruce Robert

Accurate prediction of evaporative losses from light water reactor nuclear power plant (NPP) spent fuel storage pools (SFPs) is important for activities ranging from sizing of water makeup systems during NPP design to predicting the time available to supply emergency makeup water following severe accidents. Existing correlations for predicting evaporation from water surfaces are only optimized for conditions typical of swimming pools. This new approach modeling evaporation as a diffusion process has yielded an evaporation rate model that provided a better fit of published high temperature evaporation data and measurements from two SFPs than other published evaporation correlations. Insights from treating evaporation as a diffusion process include correcting for the effects of air flow and solutes on evaporation rate. An accurate modeling of the effects of air flow on evaporation rate is required to explain the observed temperature data from the Fukushima Daiichi Unit 4 SFP during the 2011 loss of cooling event; the diffusion model of evaporation provides a significantly better fit to this data than existing evaporation models.

Regional differences of maternal health care utilization in China.

PubMed

Tang, Mengsha; Wang, Debin; Hu, Hong; Wang, Guoping; Li, Rongjie

2015-03-01

To describe regional differences in maternal health care (MHC) utilization in China. Cross-sectional comparisons of 4 MHC utilization indicators, namely, early (13 weeks within pregnancy) examinations rate (EER), prenatal examination (>4 times) rate (PER), hospital delivery rate (HDR), and postnatal visit (>1 time) rate (PVR), using index of dissimilarity (ID), linear correlation analysis, and geographical mapping. Significant differences existed across regions in all the indicators (P < .01). All the IDs for rural areas were higher than that for urban areas. The IDs for major regions ranged from 0.01 to 0.27. Linear correlation coefficients between MHC utilization indicators by regions varied from 0.007 to 0.889 (in absolute value, P < .05). Characteristic formats of geographical distribution were found with PER, EER, HDR, and PVR being in "high-plateau," "low-plateau," and "shifting" patterns, respectively. There exist substantial regional discrepancies in MHC utilization in China and future MHC-related policies should take account regional context. © 2013 APJPH.

Correlational Study of Sleep Apnea Patient Characteristics With Discharge Locations.

PubMed

Lee, Esther; Daugherty, JoAnn; Burkard, Joseph

2016-10-01

To determine if a correlation exists between OSA patient characteristics and the PACU discharge location; and the characteristics of the patients at-risk for low saturation levels, increased number of desaturations, and longer length of stay in the PACU. Retrospective, correlational study design. Chart review of OSA patients ≥ 18 years old. Correlational analysis was performed between 15 high risk patient variables and the PACU discharge disposition: home or monitored bed. Complications resulting in monitored bed admission were reviewed. 153 patients' charts were reviewed. The results showed that age>60, ASA classification, anesthesia type and narcotics use in the PACU were significantly correlated (p≤.05) with a patient's discharge disposition. The findings are consistent with other OSA research except BMI was not significant in this study. The results highlighted areas for future research and implications for clinical practice that would enable the perioperative care team to deliver safe care based on evidence. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

Condensation heat transfer and pressure drop of R-410A in flat aluminum multi-port tubes

NASA Astrophysics Data System (ADS)

Kim, Nae-Hyun

2018-02-01

Brazed heat exchangers with aluminum flat multi-port tubes are being used as condensers of residential air-conditioners. In this study, R-410A condensation tests were conducted in four multi-port tubes having a range of hydraulic diameter (0.78 ≤ Dh ≤ 0.95 mm). The test range covered the mass flux from 100 to 400 kg/m2 s and the heat flux at 3 kW/m2, which are typical operating conditions of residential air conditioners. Results showed that both the heat transfer coefficient and the pressure drop increased as the hydraulic diameter decreased. The effect of hydraulic diameter on condensation heat transfer was much larger than the predictions of existing correlations for the range of investigation. Comparison of the data with the correlations showed that some macro-channel tube correlations and mini-channel tube correlations reasonably predicted the heat transfer coefficient. However, macro-channel correlations highly overpredicted the pressure drop data.

Spatial Distribution Characteristics of Healthcare Facilities in Nanjing: Network Point Pattern Analysis and Correlation Analysis.

PubMed

Ni, Jianhua; Qian, Tianlu; Xi, Changbai; Rui, Yikang; Wang, Jiechen

2016-08-18

The spatial distribution of urban service facilities is largely constrained by the road network. In this study, network point pattern analysis and correlation analysis were used to analyze the relationship between road network and healthcare facility distribution. The weighted network kernel density estimation method proposed in this study identifies significant differences between the outside and inside areas of the Ming city wall. The results of network K-function analysis show that private hospitals are more evenly distributed than public hospitals, and pharmacy stores tend to cluster around hospitals along the road network. After computing the correlation analysis between different categorized hospitals and street centrality, we find that the distribution of these hospitals correlates highly with the street centralities, and that the correlations are higher with private and small hospitals than with public and large hospitals. The comprehensive analysis results could help examine the reasonability of existing urban healthcare facility distribution and optimize the location of new healthcare facilities.

Laboratory demonstration of Stellar Intensity Interferometry using a software correlator

NASA Astrophysics Data System (ADS)

Matthews, Nolan; Kieda, David

2017-06-01

In this talk I will present measurements of the spatial coherence function of laboratory thermal (black-body) sources using Hanbury-Brown and Twiss interferometry with a digital off-line correlator. Correlations in the intensity fluctuations of a thermal source, such as a star, allow retrieval of the second order coherence function which can be used to perform high resolution imaging and source geometry characterization. We also demonstrate that intensity fluctuations between orthogonal polarization states are uncorrelated but can be used to reduce systematic noise. The work performed here can readily be applied to existing and future Imaging Air-Cherenkov telescopes to measure spatial properties of stellar sources. Some possible candidates for astronomy applications include close binary star systems, fast rotators, Cepheid variables, and potentially even exoplanet characterization.

Two-point correlators revisited: fast and slow scales in multifield models of inflation

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

Ghersi, José T. Gálvez; Frolov, Andrei V., E-mail: joseg@sfu.ca, E-mail: frolov@sfu.ca

2017-05-01

We study the structure of two-point correlators of the inflationary field fluctuations in order to improve the accuracy and efficiency of the existing methods to calculate primordial spectra. We present a description motivated by the separation of the fast and slow evolving components of the spectrum which is based on Cholesky decomposition of the field correlator matrix. Our purpose is to rewrite all the relevant equations of motion in terms of slowly varying quantities. This is important in order to consider the contribution from high-frequency modes to the spectrum without affecting computational performance. The slow-roll approximation is not required tomore » reproduce the main distinctive features in the power spectrum for each specific model of inflation.« less

Correlation of Lunar South Polar Epithermal Neutron Maps: Lunar Exploration Neutron Detector and Lunar Prospector Neutron Detector

NASA Technical Reports Server (NTRS)

McClanahan, Timothy P.; Mitrofanov, I. G.; Boynton, W. V.; Sagdeev, R.; Trombka, J. I.; Starr, R. D.; Evans, L. G.; Litvak, M. L.; Chin, G.; Garvin, J.;

Computational architecture of the yeast regulatory network

NASA Astrophysics Data System (ADS)

Maslov, Sergei; Sneppen, Kim

2005-12-01

The topology of regulatory networks contains clues to their overall design principles and evolutionary history. We find that while in- and out-degrees of a given protein in the regulatory network are not correlated with each other, there exists a strong negative correlation between the out-degree of a regulatory protein and in-degrees of its targets. Such correlation positions large regulatory modules on the periphery of the network and makes them rather well separated from each other. We also address the question of relative importance of different classes of proteins quantified by the lethality of null-mutants lacking one of them as well as by the level of their evolutionary conservation. It was found that in the yeast regulatory network highly connected proteins are in fact less important than their low-connected counterparts.

High-resolution electron microscope observation of voids in amorphous Ge.

NASA Technical Reports Server (NTRS)

Donovan, T. M.; Heinemann, K.

1971-01-01

Electron micrographs have been obtained which clearly show the existence of a void network in amorphous Ge films formed at substrate temperatures of 25 and 150 C, and the absence of a void network in films formed at higher substrate temperatures of 200 and 250 C. These results correlate quite well with density measurements and predictions of void densities by indirect methods.

Polonium-210 content of human tissues in relation to dietary habit.

PubMed

Hill, C R

1966-05-27

Concentrations of polonium-210, a natural fallout nuclide, in human placentas collected in northern Canada ranged up to 27.8 picocuries per 100 grains, or 80 times the average United Kingdom value. High levels are related to the inclusion of reindeer or caribou meat in the diet, and a correlation exists between the eoncentrations of polonium-210 and cesium-137 in the placentas.

Role of Insulin in Endogenous Hypertriglyceridemia*

PubMed Central

Reaven, Gerald M.; Lerner, Roger L.; Stern, Michael P.; Farquhar, John W.

1967-01-01

Dietary carbohydrate accentuation of endogenous triglyceride production has been studied in 33 patients. A broad and relatively continuous spectrum of steady-state plasma triglyceride concentrations was produced in 31 of the 33 subjects during 3 wk of a high carbohydrate (fat-free) liquid formula diet. Two patients developed plasma triglyceride concentrations in excess of 2000 mg/100 ml, and these were the only patients we have studied in which carbohydrate induction of hypertriglyceridemia seemed to be associated with a defect in endogenous plasma triglyceride removal mechanisms. In the remaining 31 patients the degree of hypertriglyceridemia was highly correlated with the insulin response elicited by the ingestion of the high carbohydrate formula (P < 0.005). No significant correlation existed between fasting plasma triglyceride concentration and either plasma glucose or free fatty acid concentrations after the high carbohydrate diet, nor was the degree of hypertriglyceridemia related to degree of obesity. It is suggested that hypertriglyceridemia in most subjects results from an increase in hepatic triglyceride secretion rate secondary to exaggerated postprandial increases in plasma insulin concentration. Images PMID:6061748

Seeing and Reading Red: Hue and Color-word Correlation in Images and Attendant Text on the WWW

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

Newsam, S

2004-07-12

This work represents an initial investigation into determining whether correlations actually exist between metadata and content descriptors in multimedia datasets. We provide a quantitative method for evaluating whether the hue of images on the WWW is correlated with the occurrence of color-words in metadata such as URLs, image names, and attendant text. It turns out that such a correlation does exist: the likelihood that a particular color appears in an image whose URL, name, and/or attendant text contains the corresponding color-word is generally at least twice the likelihood that the color appears in a randomly chosen image on the WWW.more » While this finding might not be significant in and of itself, it represents an initial step towards quantitatively establishing that other, perhaps more useful correlations exist. These correlations form the basis for exciting novel approaches that leverage semi-supervised datasets, such as the WWW, to overcome the semantic gap that has hampered progress in multimedia information retrieval for some time now.« less

Generation and control of Greenberger-Horne-Zeilinger entanglement in superconducting circuits.

PubMed

Wei, L F; Liu, Yu-xi; Nori, Franco

2006-06-23

Going beyond the entanglement of microscopic objects (such as photons, spins, and ions), here we propose an efficient approach to produce and control the quantum entanglement of three macroscopic coupled superconducting qubits. By conditionally rotating, one by one, selected Josephson-charge qubits, we show that their Greenberger-Horne-Zeilinger (GHZ) entangled states can be deterministically generated. The existence of GHZ correlations between these qubits could be experimentally demonstrated by effective single-qubit operations followed by high-fidelity single-shot readouts. The possibility of using the prepared GHZ correlations to test the macroscopic conflict between the noncommutativity of quantum mechanics and the commutativity of classical physics is also discussed.

[Correlation between iridology and general pathology].

PubMed

Demea, Sorina

2002-01-01

The research proposal is to evaluate the association between certain irian signs and general pathology of studied patients. There were studied 57 hospitalized patients; there was taken over all their iris images, which were analyzed through iridological protocols; in the same time the pathology of these patients was noted from their records in the hospital, concordant with the clinical diagnosis; all these information were included in a database for a computerised processing. The correlations resulted from, shows a high connection between the irian constitution establish through iridological criteria and the existent pathology. Iris examination can be very useful for diagnosis of a certain general pathology, in a holistic approach of the patient.

Quantifying Differential Privacy under Temporal Correlations.

PubMed

Cao, Yang; Yoshikawa, Masatoshi; Xiao, Yonghui; Xiong, Li

2017-04-01

Differential Privacy (DP) has received increasing attention as a rigorous privacy framework. Many existing studies employ traditional DP mechanisms (e.g., the Laplace mechanism) as primitives, which assume that the data are independent, or that adversaries do not have knowledge of the data correlations. However, continuous generated data in the real world tend to be temporally correlated, and such correlations can be acquired by adversaries. In this paper, we investigate the potential privacy loss of a traditional DP mechanism under temporal correlations in the context of continuous data release. First, we model the temporal correlations using Markov model and analyze the privacy leakage of a DP mechanism when adversaries have knowledge of such temporal correlations. Our analysis reveals that the privacy loss of a DP mechanism may accumulate and increase over time . We call it temporal privacy leakage . Second, to measure such privacy loss, we design an efficient algorithm for calculating it in polynomial time. Although the temporal privacy leakage may increase over time, we also show that its supremum may exist in some cases. Third, to bound the privacy loss, we propose mechanisms that convert any existing DP mechanism into one against temporal privacy leakage. Experiments with synthetic data confirm that our approach is efficient and effective.

Detrended cross-correlations between returns, volatility, trading activity, and volume traded for the stock market companies

NASA Astrophysics Data System (ADS)

Rak, Rafał; Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł

2015-11-01

We consider a few quantities that characterize trading on a stock market in a fixed time interval: logarithmic returns, volatility, trading activity (i.e., the number of transactions), and volume traded. We search for the power-law cross-correlations among these quantities aggregated over different time units from 1 min to 10 min. Our study is based on empirical data from the American stock market consisting of tick-by-tick recordings of 31 stocks listed in Dow Jones Industrial Average during the years 2008-2011. Since all the considered quantities except the returns show strong daily patterns related to the variable trading activity in different parts of a day, which are the most evident in the autocorrelation function, we remove these patterns by detrending before we proceed further with our study. We apply the multifractal detrended cross-correlation analysis with sign preserving (MFCCA) and show that the strongest power-law cross-correlations exist between trading activity and volume traded, while the weakest ones exist (or even do not exist) between the returns and the remaining quantities. We also show that the strongest cross-correlations are carried by those parts of the signals that are characterized by large and medium variance. Our observation that the most convincing power-law cross-correlations occur between trading activity and volume traded reveals the existence of strong fractal-like coupling between these quantities.

Correlation of compliance to statin therapy with lipid profile and serum HMGCoA reductase levels in dyslipidemic patients.

PubMed

Grover, Abhinav; Rehan, Harmeet Singh; Gupta, Lalit Kumar; Yadav, Madhur

The efficacy of statin therapy may be lost or vary with reduction in compliance and intensity of statin therapy. To study and correlate the quantitative effect of compliance on lipid profile and 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMGCoA-R) levels in dyslipidemic patients. Compliance to different intensity of statin therapy assessed by pill count was correlated with serum levels of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), triglycerides (TG), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and HMGCoA-R. Out of 200 patients, 160 received moderate intensity statin therapy whereas 40 were on high intensity statin therapy. The overall mean compliance of patients was 56.7%. The compliance of patients on moderate intensity statin therapy was higher (56.8%) than those on high intensity (56.4%) (p=0.92). There was significant inverse correlation (p<0.05) between compliance and TC, TG, LDL-C and HMGCoA-R levels and positive correlation (p<0.05) with HDL-C levels. The mean serum HMGCoA-R levels did not fall below 9-10ng/mL when compliance to either moderate or high intensity statin therapy was increased above 60%. It is appropriate to improve the compliance to existing statin therapy than switching over to higher intensity statin therapy. Estimation of HMGCoA-R levels may be explored as a surrogate marker to monitor and assess the compliance of patients to statin therapy. Copyright © 2016. Published by Elsevier B.V.

Correlation Between High-sensitivity C-reactive Protein and Reactive Oxygen Metabolites During A One-year Period Among Asymptomatic Subjects

PubMed Central

Kotani, Kazuhiko; Taniguchi, Nobuyuki

2012-01-01

Background Inflammation and oxidative stress are associated with human health and the disease status. The present study aimed to investigate the longitudinal correlation between the diacron reactive oxygen metabolites (d-ROMs) level, as an oxidative stress-related marker, and high-sensitivity C-reactive protein (hsCRP), as an inflammatory marker, during a one-year period among asymptomatic subjects. Methods The data, including anthropometric and biochemical markers, were collected at baseline and after the one-year period from 71 participants (male/female = 41/30, mean age 50 years). The correlation between the changes of the d-ROMs and hsCRP levels during the study period was examined. Results A simple correlation analysis showed a significant and positive correlation to exist between the changes of the d-ROMs and hsCRP levels (r = 0.40, P < 0.01). This significant correlation remained independent in a multiple linear regression analysis adjusted for confounding factors. Conclusions The present findings suggest that the relationship between the d-ROMs and hsCRP levels could be prospectively followed, and that monitoring both markers may help to better understand the cooperation of inflammation and oxidative stress in association with health and disease. Further studies are necessary to clarify the biological mechanism(s) responsible for the observed relationship. Keywords Oxidative stress; Oxygen reactive species; Inflammation; CRP PMID:22383928

Comparison of high pressure transient PVT measurements and model predictions. Part I.

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

Felver, Todd G.; Paradiso, Nicholas Joseph; Evans, Gregory Herbert

2010-07-01

A series of experiments consisting of vessel-to-vessel transfers of pressurized gas using Transient PVT methodology have been conducted to provide a data set for optimizing heat transfer correlations in high pressure flow systems. In rapid expansions such as these, the heat transfer conditions are neither adiabatic nor isothermal. Compressible flow tools exist, such as NETFLOW that can accurately calculate the pressure and other dynamical mechanical properties of such a system as a function of time. However to properly evaluate the mass that has transferred as a function of time these computational tools rely on heat transfer correlations that must bemore » confirmed experimentally. In this work new data sets using helium gas are used to evaluate the accuracy of these correlations for receiver vessel sizes ranging from 0.090 L to 13 L and initial supply pressures ranging from 2 MPa to 40 MPa. The comparisons show that the correlations developed in the 1980s from sparse data sets perform well for the supply vessels but are not accurate for the receivers, particularly at early time during the transfers. This report focuses on the experiments used to obtain high quality data sets that can be used to validate computational models. Part II of this report discusses how these data were used to gain insight into the physics of gas transfer and to improve vessel heat transfer correlations. Network flow modeling and CFD modeling is also discussed.« less

Type 2 diabetes mellitus in Navajo adolescents.

PubMed Central

Kim, C; McHugh, C; Kwok, Y; Smith, A

1999-01-01

Diabetes mellitus afflicts over one-fifth of the Navajo population aged over 20 years, but the prevalence of diabetes in Navajo adolescents is unclear. We conducted voluntary testing for diabetes mellitus at two high schools on the Navajo reservation to clarify the prevalence as well as to assess the utility of a high-school based screening program. Body mass index measurements (BMI), oral glucose tolerance tests, and hemoglobin A1C measurements were obtained in consenting high school students. Of the 276 students that participated, 234 were Navajo. Only one Navajo student (0.4%) had diabetes mellitus, although eight (3%) had impaired glucose tolerance or impaired fasting glucose. Participant BMI did not differ significantly from nonparticipant BMI. No correlation existed between BMI or impaired glucose handling, and significant overlap existed between the hemoglobin A1C values of students with impaired glucose handling and students without impaired glucose handling. Increased participation in screening programs may reveal higher disease prevalence, but high school-based screening is not justified by this study, despite the high rates of diabetes mellitus in the Navajo population. PMID:10344174

Energy: It is life

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

Arques, P.

1998-07-01

The relationships that seem to exist between energy and man are presented in this paper. Habitually, social coefficients are connected to the gross domestic product; some parameters with correlations are: birth rate, infant mortality rate, death rate, literacy, etc. Along with energy these define the optimal energy consumption per capita; the author presents the correlation between these parameters and energy consumed per capita. There exists a high correlation between energy consumption per capita and gross domestic product per capita. The set of parameters considered are correlated with similar values relative to these two parameters. Using data collected on a groupmore » of the different countries of the world, a table of 165 countries and 22 variables has been drawn up. From the [Country x variable] matrix, a correlation table is calculated and a factorial analysis is applied to this matrix. The first factorial plan comprises 57% of the information contained in this table. Results from this first factorial plan are presented. These parameters are analyzed: influence of a country's latitude on its inhabitants' consumption; relationship between consumed energy and gross domestic product; women's fertility rate; birth rate per 1000 population; sex ratio; life expectancy at birth; rate of literacy; death rate; population growth rate. Finally, it is difficult to define precise criteria for: an optimal distribution of population according to age, but with a power consumed of above 300 W per capita, the population becomes younger; the birth rate per 1000 population; the total fertility rate per woman; the population growth rate. The authors determine that optimal energy is approximately between 200 W and 677 W inclusive.« less

Assessment of Growth Using Mandibular Canine Calcification Stages and Its Correlation with Modified MP3 Stages

PubMed Central

Nayak, US Krishna; Hegde, Gautam

2010-01-01

Background and objectives Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. Methods A total of 160 periapical radiographs (80 males and 80 females), of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian’s stages of dental calcification and the modified MP3 stages. Results The correlation between the developmental stages of MP3 and the mandibular right canine in male and female groups, is of high statistical significance (p = 0.001). The correlation coefficient between MP3 stages and developmental stages of mandibular canine and chronological age in male and females was found to be not significant. Conclusions The correlation between the mandibular canine calcification stages and MP3 stages was found to be significant. The developmental stages of the mandibular canine could be used very reliably as a sole indicator for assessment of skeletal maturity. PMID:27625553

A new system for assessment of growth using mandibular canine calcification stages and its correlation with modified MP3 stages

PubMed Central

Hegde, Gautham; Hegde, Nanditha; Kumar, Anil; Keshavaraj

2014-01-01

Objective: Orthodontic diagnosis and treatment planning for growing children must involve growth prediction, especially in the treatment of skeletal problems. Studies have shown that a strong association exists between skeletal maturity and dental calcification stages. The present study was therefore taken up to provide a simple and practical method for assessing skeletal maturity using a dental periapical film and standard dental X-ray machine, to compare the developmental stages of the mandibular canine with that of developmental stages of modified MP3 and to find out if any correlation exists, to determine if the developmental stages of the mandibular canine alone can be used as a reliable indicator for assessment of skeletal maturity. Materials and Methods: A total of 160 periapical radiographs, of the mandibular right canine and the MP3 region was taken and assessed according to the Dermirjian's stages of dental calcification and the modified MP3 stages. Results and Discussion: The correlation coefficient between MP3 stages and developmental stages of mandibular canine was found to be significant in both male and female groups. When the canine calcification stages were compared with the MP3 stages it was found that with the exception of the D stage of canine calcification the remaining stages showed a very high correlation with the modified MP3 stages. Conclusion: The correlation between the mandibular canine calcification stages, and the MP3 stages was found to be significant. The canine calcification could be used as a sole indicator for assessment of skeletal maturity. PMID:25210386

Cavitation in liquid cryogens. 2: Hydrofoil

NASA Technical Reports Server (NTRS)

Hord, J.

1973-01-01

Boundary layer principles, along with two-phase concepts, are used to improve existing correlative theory for developed cavity data. Details concerning cavity instrumentation, data analysis, correlative techniques, and experimental and theoretical aspects of a cavitating hydrofoil are given. Both desinent and thermodynamic data, using liquid hydrogen and liquid nitrogen, are reported. The thermodynamic data indicated that stable thermodynamic equilibrium exists throughout the vaporous cryogen cavities. The improved correlative formulas were used to evaluate these data. A new correlating parameter based on consideration of mass limiting two-phase flow flux across the cavity interface, is proposed. This correlating parameter appears attractive for future correlative and predictive applications. Agreement between theory and experiment is discussed, and directions for future analysis are suggested. The front half of the cavities, developed on the hydrofoil, may be considered as parabolically shaped.

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

NASA Astrophysics Data System (ADS)

Ridlo, S.; Lutfiya, F.

2017-04-01

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

The Effect of Training Data Set Composition on the Performance of a Neural Image Caption Generator

DTIC Science & Technology

2017-09-01

objects was compared using the Metric for Evaluation of Translation with Explicit Ordering (METEOR) and Consensus-Based Image Description Evaluation...using automated scoring systems. Many such systems exist, including Bilingual Evaluation Understudy (BLEU), Consensus-Based Image Description Evaluation...shown to be essential to automated scoring, which correlates highly with human precision.5 CIDEr uses a system of consensus among the captions and

Acute hypoxia during organogenesis affects cardiac autonomic balance in pregnant rats.

PubMed

Maslova, M V; Graf, A V; Maklakova, A S; Krushinskaya, Ya V; Sokolova, N A; Koshelev, V B

2005-02-01

Changes in ECG parameters were studied in pregnant rats exposed to acute hypobaric hypoxia during the period of organogenesis (gestation days 9 to 10). Rats with low, medium, and high tolerance to hypoxia exhibited pronounced autonomic nervous system imbalance, which become apparent as a loss of correlation between various parameters of ECG signals recorded at rest and during exposure to some stress factors existing under normal conditions.

High-frequency dielectric study of proustite crystals Ag3AsS3

NASA Astrophysics Data System (ADS)

Bordovsky, V. A.; Gunia, N. Yu; Castro, R. A.

2014-12-01

The dielectric properties of the crystals proustite in the frequency of 106-109 Hz and a temperature range of 173 to 473 K were studied. The dispersion of the dielectric parameters indicates the existence of non-Debye relaxation mechanism correlates with structural changes in the phase transition region. The charge transfer is temperature activated with an activation energy of 2.40 ± 0.01 eV.

Synthesis of Long-Chain-Branched (LCB) Polysulfones for Multifunctional Transport Membranes

DTIC Science & Technology

2010-09-01

R.; Dutta, N. K. Interfacial Interactions in Aprotic Ionic Liquid Based Protonic Membrane and Its Correlation with High Temperature Conductivity...rigidity. The series of novel polymers was characterized for chemical structure, thermal transitions, and molecular weight. Ionic conductivity was tested...Although much progress exists based on perfluorosulfonated platforms ( Nafion , σ ≈ 10-1 – 10-2 S/cm) new and more complicated parameters arise as

Discovering high-resolution patterns of differential DNA methylation that correlate with gene expression changes

PubMed Central

VanderKraats, Nathan D.; Hiken, Jeffrey F.; Decker, Keith F.; Edwards, John R.

2013-01-01

Methylation of the CpG-rich region (CpG island) overlapping a gene’s promoter is a generally accepted mechanism for silencing expression. While recent technological advances have enabled measurement of DNA methylation and expression changes genome-wide, only modest correlations between differential methylation at gene promoters and expression have been found. We hypothesize that stronger associations are not observed because existing analysis methods oversimplify their representation of the data and do not capture the diversity of existing methylation patterns. Recently, other patterns such as CpG island shore methylation and long partially hypomethylated domains have also been linked with gene silencing. Here, we detail a new approach for discovering differential methylation patterns associated with expression change using genome-wide high-resolution methylation data: we represent differential methylation as an interpolated curve, or signature, and then identify groups of genes with similarly shaped signatures and corresponding expression changes. Our technique uncovers a diverse set of patterns that are conserved across embryonic stem cell and cancer data sets. Overall, we find strong associations between these methylation patterns and expression. We further show that an extension of our method also outperforms other approaches by generating a longer list of genes with higher quality associations between differential methylation and expression. PMID:23748561

[Changes of insulin resistance and islet beta cells function in subjects with high-normal blood pressure].

PubMed

Xu, Ling-Ling; Xiang, Hong-Ding; Zhang, Li-Hong; Chen, Wei; Fang, Jing-Hui

2009-08-01

To investigate the changes of insulin resistance and islet beta cells function in subjects with euglycemia and high-normal blood pressure. Total 423 subjects were divided into normal blood pressure group and high-normal blood pressure group. Body height, weight, waist and hip circumference, and biochemical data were measured. Homeostasis model assessment of insulin resistance (HOMA-IR), insulin sensitivity index (ISI)-composite, and first-phase (1 PH) Stumvoll index were calculated. Results Waist circumference, total cholesterol, triglyceride, low-density lipoprotein cholesterol, HOMA-IR were significantly higher and IPH Stumvoll index and ISI-composite were significantly lower in high-normal blood pressure group than in normal blood pressure group (P < 0.05). Systolic blood pressure (SBP) was positively correlated with HOMA-IR (r = 0.122) and negatively correlated with 1PH Stumvoll index (r = -0. 159) and ISI-composite (r = -0.131) (P < 0.05). SBP and triglyceride were independent factors for IPH Stumvoll index. Insulin resistance and islet dysfunction may exist in subjects with high-normal blood pressure.

Atmospheric response to Saharan dust deduced from ECMWF reanalysis (ERA) temperature increments

NASA Astrophysics Data System (ADS)

Kishcha, P.; Alpert, P.; Barkan, J.; Kirchner, I.; Machenhauer, B.

2003-09-01

This study focuses on the atmospheric temperature response to dust deduced from a new source of data the European Reanalysis (ERA) increments. These increments are the systematic errors of global climate models, generated in the reanalysis procedure. The model errors result not only from the lack of desert dust but also from a complex combination of many kinds of model errors. Over the Sahara desert the lack of dust radiative effect is believed to be a predominant model defect which should significantly affect the increments. This dust effect was examined by considering correlation between the increments and remotely sensed dust. Comparisons were made between April temporal variations of the ERA analysis increments and the variations of the Total Ozone Mapping Spectrometer aerosol index (AI) between 1979 and 1993. The distinctive structure was identified in the distribution of correlation composed of three nested areas with high positive correlation (>0.5), low correlation and high negative correlation (<-0.5). The innermost positive correlation area (PCA) is a large area near the center of the Sahara desert. For some local maxima inside this area the correlation even exceeds 0.8. The outermost negative correlation area (NCA) is not uniform. It consists of some areas over the eastern and western parts of North Africa with a relatively small amount of dust. Inside those areas both positive and negative high correlations exist at pressure levels ranging from 850 to 700 hPa, with the peak values near 775 hPa. Dust-forced heating (cooling) inside the PCA (NCA) is accompanied by changes in the static instability of the atmosphere above the dust layer. The reanalysis data of the European Center for Medium Range Weather Forecast (ECMWF) suggest that the PCA (NCA) corresponds mainly to anticyclonic (cyclonic) flow, negative (positive) vorticity and downward (upward) airflow. These findings are associated with the interaction between dust-forced heating/cooling and atmospheric circulation. This paper contributes to a better understanding of dust radiative processes missed in the model.

Correlating off-axis tension tests to shear modulus of wood-based panels

Treesearch

Edmond P. Saliklis; Robert H. Falk

2000-01-01

The weakness of existing relationships correlating off-axis modulus of elasticity E q to shear modulus G 12 for wood composite panels is demonstrated through presentation of extensive experimental data. A new relationship is proposed that performs better than existing equations found in the literature. This relationship can be manipulated to calculate the shear modulus...

The link between callosal thickness and intelligence in healthy children and adolescents.

PubMed

Luders, Eileen; Thompson, Paul M; Narr, Katherine L; Zamanyan, Alen; Chou, Yi-Yu; Gutman, Boris; Dinov, Ivo D; Toga, Arthur W

2011-02-01

The link between brain structure and intelligence is a well-investigated topic, but existing analyses have mainly focused on adult samples. Studies in healthy children and adolescents are rare, and normative data specifically addressing the association between corpus callosum morphology and intellectual abilities are quite limited. To advance this field of research, we mapped the correlations between standardized intelligence measures and callosal thickness based on high-resolution magnetic resonance imaging (MRI) data. Our large and well-matched sample included 200 normally developing subjects (100 males, 100 females) ranging from 6 to 17 years of age. Although the strongest correlations were negative and confined to the splenium, the strength and the direction of intelligence-callosal thickness associations varied considerably. While significant correlations in females were mainly positive, significant correlations in males were exclusively negative. However, only the negative correlations in the overall sample (i.e., males and females combined) remained significant when controlling for multiple comparisons. The observed negative correlations between callosal thickness and intelligence in children and adolescents contrast with the positive correlations typically reported in adult samples. However, negative correlations are in line with reports from other pediatric studies relating cognitive measures to other brain attributes such as cortical thickness, gray matter volume, and gray matter density. Altogether, these findings suggest that relationships between callosal morphology and cognition are highly dynamic during brain maturation. Sex effects on links between callosal thickness and intelligence during childhood and adolescence are present but appear rather weak in general. Copyright © 2010 Elsevier Inc. All rights reserved.

The link between callosal thickness and intelligence in healthy children and adolescents

PubMed Central

Luders, Eileen; Thompson, Paul M.; Narr, Katherine L.; Zamanyan, Alen; Chou, Yi-Yu; Gutman, Boris; Dinov, Ivo D.; Toga, Arthur W.

2010-01-01

The link between brain structure and intelligence is a well-investigated topic, but existing analyses have mainly focused on adult samples. Studies in healthy children and adolescents are rare, and normative data specifically addressing the association between corpus callosum morphology and intellectual abilities is quite limited. To advance this field of research, we mapped the correlations between standardized intelligence measures and callosal thickness based on high-resolution magnetic resonance imaging (MRI) data. Our large and well-matched sample included 200 normally developing subjects (100 males, 100 females) ranging from 6 to 17 years of age. Although the strongest correlations were negative and confined to the splenium, the strength and the direction of intelligence-callosal thickness associations varied considerably with respect to age and sex. While significant correlations in females were mainly positive, significant correlations in males were exclusively negative. However, only the negative correlations in the overall sample (i.e., males and females combined) remained significant when controlling for multiple comparisons. The observed negative correlations between callosal thickness and intelligence in children and adolescents contrast with the positive correlations typically reported in adult samples. However, negative correlations are in line with reports from other pediatric studies relating cognitive measures to other brain attributes such as cortical thickness, gray matter volume, and gray matter density. Altogether, these findings suggest that relationships between callosal morphology and cognition are highly dynamic during brain maturation. Sex effects on links between callosal thickness and intelligence during childhood and adolescence are present but appear rather weak in general. PMID:20932920

Information content exploitation of imaging spectrometer's images for lossless compression

NASA Astrophysics Data System (ADS)

Wang, Jianyu; Zhu, Zhenyu; Lin, Kan

1996-11-01

Imaging spectrometer, such as MAIS produces a tremendous volume of image data with up to 5.12 Mbps raw data rate, which needs urgently a real-time, efficient and reversible compression implementation. Between the lossy scheme with high compression ratio and the lossless scheme with high fidelity, we must make our choice based on the particular information content analysis of each imaging spectrometer's image data. In this paper, we present a careful analysis of information-preserving compression of imaging spectrometer MAIS with an entropy and autocorrelation study on the hyperspectral images. First, the statistical information in an actual MAIS image, captured in Marble Bar Australia, is measured with its entropy, conditional entropy, mutual information and autocorrelation coefficients on both spatial dimensions and spectral dimension. With these careful analyses, it is shown that there is high redundancy existing in the spatial dimensions, but the correlation in spectral dimension of the raw images is smaller than expected. The main reason of the nonstationarity on spectral dimension is attributed to the instruments's discrepancy on detector's response and channel's amplification in different spectral bands. To restore its natural correlation, we preprocess the signal in advance. There are two methods to accomplish this requirement: onboard radiation calibration and normalization. A better result can be achieved by the former one. After preprocessing, the spectral correlation increases so high that it contributes much redundancy in addition to spatial correlation. At last, an on-board hardware implementation for the lossless compression is presented with an ideal result.

Injury Source and Correlation Analysis of Riders in Car-Electric Bicycle Accidents.

PubMed

Zou, Tiefang; Yi, Liang; Cai, Ming; Hu, Lin; Li, Yuelin

2018-01-01

The knowledge about the injury source and correlation of riders in car-electric bicycle accident will be helpful in the cross validation of traces and vehicle safety design. In order to know more information about such kind of knowledge, 57 true car-electric bicycle accidents were reconstructed by PC-Crash and then data on injury information of riders were collected directly from the reconstructed cases. These collected data were validated by some existing research results firstly, and then 4 abnormal cases were deleted according to the statistical method. Finally, conclusions can be obtained according to the data obtained from the remaining 53 cases. Direct injuries of the head and right leg are from the road pavement upon low speed; the source laws of indirect head injuries are not obvious. Upon intermediate and high speed, the injuries of the above parts are from automobiles. Injuries of the left leg, femur, and right knee are from automobiles; left knee injuries are from automobiles, the road pavement and automobiles, respectively, upon low, intermediate, and high speed. The source laws of indirect torso injuries are not obvious upon intermediate and low speed, which are from automobiles upon high speed, while direct torso injuries are from the road pavement. And there is no high correlation between all parts of the injury of riders. The largest correlation coefficient was the head-left femur and left femur-right femur, which was 0.647, followed by the head-right femur (0.638) and head-torso which was 0.617.

Validation of the oesophageal hypervigilance and anxiety scale for chronic oesophageal disease.

PubMed

Taft, T H; Triggs, J R; Carlson, D A; Guadagnoli, L; Tomasino, K N; Keefer, L; Pandolfino, J E

2018-05-01

Oesophageal hypervigilance and anxiety can drive symptom experience in chronic oesophageal conditions, including gastro-oesophageal reflux disease, achalasia and functional oesophageal disorders. To date, no validated self-report measure exists to evaluate oesophageal hypervigilance and anxiety. This study aims to develop a brief and reliable questionnaire assessing these constructs, the oesophageal hypervigilance and anxiety scale (EHAS). Questions for the EHAS were drawn from 4 existing validated measures that assessed hypervigilance and anxiety adapted for the oesophagus. Patients who previously underwent high-resolution manometry testing at a university-based oesophageal motility clinic were retrospectively identified. Patients were included in the analysis if they completed the EHAS as well as questionnaires assessing symptom severity and health-related quality of life at the time of the high-resolution manometry. Nine hundred and eighty-two patients aged 18-85 completed the study. The EHAS demonstrates excellent internal consistency (α = 0.93) and split-half reliability (Guttman = 0.87). Inter-item correlations indicated multicollinearity was not achieved; thus, no items were removed from the original 15-item scale. Principal components factor analysis revealed two subscales measuring symptom-specific anxiety and symptom-specific hypervigilance. Construct validity for total and subscale scores was supported by positive correlations with symptom severity and negative correlations with health-related quality of life. The EHAS is a 15-item scale assessing oesophageal hypervigilance and symptom-specfic anxiety. The EHAS could be useful in evaluating the role of these constructs in several oesophageal conditions in which hypersensitivity, hypervigilance and anxiety may contribute to symptoms and impact treatment outcomes. © 2018 John Wiley & Sons Ltd.

Estimation of Comfort/Disconfort Based on EEG in Massage by Use of Clustering according to Correration and Incremental Learning type NN

NASA Astrophysics Data System (ADS)

Teramae, Tatsuya; Kushida, Daisuke; Takemori, Fumiaki; Kitamura, Akira

Authors proposed the estimation method combining k-means algorithm and NN for evaluating massage. However, this estimation method has a problem that discrimination ratio is decreased to new user. There are two causes of this problem. One is that generalization of NN is bad. Another one is that clustering result by k-means algorithm has not high correlation coefficient in a class. Then, this research proposes k-means algorithm according to correlation coefficient and incremental learning for NN. The proposed k-means algorithm is method included evaluation function based on correlation coefficient. Incremental learning is method that NN is learned by new data and initialized weight based on the existing data. The effect of proposed methods are verified by estimation result using EEG data when testee is given massage.

Spatio-temporal Reconstruction of Neural Sources Using Indirect Dominant Mode Rejection.

PubMed

Jafadideh, Alireza Talesh; Asl, Babak Mohammadzadeh

2018-04-27

Adaptive minimum variance based beamformers (MVB) have been successfully applied to magnetoencephalogram (MEG) and electroencephalogram (EEG) data to localize brain activities. However, the performance of these beamformers falls down in situations where correlated or interference sources exist. To overcome this problem, we propose indirect dominant mode rejection (iDMR) beamformer application in brain source localization. This method by modifying measurement covariance matrix makes MVB applicable in source localization in the presence of correlated and interference sources. Numerical results on both EEG and MEG data demonstrate that presented approach accurately reconstructs time courses of active sources and localizes those sources with high spatial resolution. In addition, the results of real AEF data show the good performance of iDMR in empirical situations. Hence, iDMR can be reliably used for brain source localization especially when there are correlated and interference sources.

Correlates of insight into different symptom dimensions in obsessive-compulsive disorder.

PubMed

Fontenelle, Jùlia M; Harrison, Ben J; Santana, Lívia; Conceição do Rosário, Maria; Versiani, Marcio; Fontenelle, Leonardo F

2013-02-01

In this study, we evaluated insight into different obsessive-compulsive disorder (OCD) symptom dimensions and their impact on clinical and sociodemographic features of patients with OCD. Sixty OCD patients were assessed with the Brown Assessment of Beliefs Scale (BABS), the Dimensional Yale-Brown Obsessive-Compulsive Scale-Short Version, the Beck Depression Inventory, and the Sheehan Disability Scale. Two methods of using BABS were employed: 1) a traditional approach, which considers a composite of the insight into existing OCD symptoms, and 2) an alternative approach, which includes assessments of insight into each OCD symptom dimension separately. Composite BABS scores correlated with global severity of OCD and depressive symptoms, and degree of interference on social life/leisure activities and family life/home responsibilities. Dimension-specific correlations between severity of symptoms and insight ranged from very high (P = .87, for hoarding) to moderate (P = .61, for miscellaneous symptoms). Greater severity of depression and concomitant generalized anxiety disorder were independently associated with lower levels of insight into aggressive/checking symptoms. While earlier-onset OCD was associated with lower insight into sexual/religious and symmetry symptoms, later-onset OCD displayed lower insight into hoarding. Assessing insight into dimension-specific OCD symptoms may challenge the existence of clear-cut OCD with fair or poor insight.

Computing Challenges in Coded Mask Imaging

NASA Technical Reports Server (NTRS)

Skinner, Gerald

2009-01-01

This slide presaentation reviews the complications and challenges in developing computer systems for Coded Mask Imaging telescopes. The coded mask technique is used when there is no other way to create the telescope, (i.e., when there are wide fields of view, high energies for focusing or low energies for the Compton/Tracker Techniques and very good angular resolution.) The coded mask telescope is described, and the mask is reviewed. The coded Masks for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) instruments are shown, and a chart showing the types of position sensitive detectors used for the coded mask telescopes is also reviewed. Slides describe the mechanism of recovering an image from the masked pattern. The correlation with the mask pattern is described. The Matrix approach is reviewed, and other approaches to image reconstruction are described. Included in the presentation is a review of the Energetic X-ray Imaging Survey Telescope (EXIST) / High Energy Telescope (HET), with information about the mission, the operation of the telescope, comparison of the EXIST/HET with the SWIFT/BAT and details of the design of the EXIST/HET.

Quantifying Differential Privacy under Temporal Correlations

PubMed Central

Cao, Yang; Yoshikawa, Masatoshi; Xiao, Yonghui; Xiong, Li

2017-01-01

Differential Privacy (DP) has received increasing attention as a rigorous privacy framework. Many existing studies employ traditional DP mechanisms (e.g., the Laplace mechanism) as primitives, which assume that the data are independent, or that adversaries do not have knowledge of the data correlations. However, continuous generated data in the real world tend to be temporally correlated, and such correlations can be acquired by adversaries. In this paper, we investigate the potential privacy loss of a traditional DP mechanism under temporal correlations in the context of continuous data release. First, we model the temporal correlations using Markov model and analyze the privacy leakage of a DP mechanism when adversaries have knowledge of such temporal correlations. Our analysis reveals that the privacy loss of a DP mechanism may accumulate and increase over time. We call it temporal privacy leakage. Second, to measure such privacy loss, we design an efficient algorithm for calculating it in polynomial time. Although the temporal privacy leakage may increase over time, we also show that its supremum may exist in some cases. Third, to bound the privacy loss, we propose mechanisms that convert any existing DP mechanism into one against temporal privacy leakage. Experiments with synthetic data confirm that our approach is efficient and effective. PMID:28883711

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

NASA Astrophysics Data System (ADS)

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

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

Axioms for quantum mechanics: relativistic causality, retrocausality, and the existence of a classical limit

NASA Astrophysics Data System (ADS)

Rohrlich, Daniel

Y. Aharonov and A. Shimony both conjectured that two axioms - relativistic causality (``no superluminal signalling'') and nonlocality - so nearly contradict each other that only quantum mechanics reconciles them. Can we indeed derive quantum mechanics, at least in part, from these two axioms? No: ``PR-box'' correlations show that quantum correlations are not the most nonlocal correlations consistent with relativistic causality. Here we replace ``nonlocality'' with ``retrocausality'' and supplement the axioms of relativistic causality and retrocausality with a natural and minimal third axiom: the existence of a classical limit, in which macroscopic observables commute. That is, just as quantum mechanics has a classical limit, so must any generalization of quantum mechanics. In this limit, PR-box correlations violaterelativistic causality. Generalized to all stronger-than-quantum bipartite correlations, this result is a derivation of Tsirelson's bound (a theorem of quantum mechanics) from the three axioms of relativistic causality, retrocausality and the existence of a classical limit. Although the derivation does not assume quantum mechanics, it points to the Hilbert space structure that underlies quantum correlations. I thank the John Templeton Foundation (Project ID 43297) and the Israel Science Foundation (Grant No. 1190/13) for support.

An evaluation of acquired data as a tool for management of wildlife habitat in Alaska

NASA Technical Reports Server (NTRS)

Vantries, B. J. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Density sliced and digitized imagery of the Kuskokwin/Yukon Delta were analyzed. Color coded images of the isodensity displays were compared with existing vegetation maps of the ERTS-1 frames for the Yukon/Kuskokwin area. A high degree of positive correlation was found to exist between the ERTS-1 image and the conventionally prepared maps. Hydrologic phenomena were also analyzed. Digitization on South Dakota State Remote Sensing Center's SADE system provide some discrimination among several large lakes in the subject area. However, interpretation must await ground observations and depth measurements. An attempt will be made to classify large water bodies by depth classes.

Exercise economy in skiing and running

PubMed Central

Losnegard, Thomas; Schäfer, Daniela; Hallén, Jostein

2014-01-01

Substantial inter-individual variations in exercise economy exist even in highly trained endurance athletes. The variation is believed to be determined partly by intrinsic factors. Therefore, in the present study, we compared exercise economy in V2-skating, double poling, and uphill running. Ten highly trained male cross-country skiers (23 ± 3 years, 180 ± 6 cm, 75 ± 8 kg, VO2peak running: 76.3 ± 5.6 mL·kg−1·min−1) participated in the study. Exercise economy and VO2peak during treadmill running, ski skating (V2 technique) and double poling were compared based on correlation analysis. There was a very large correlation in exercise economy between V2-skating and double poling (r = 0.81) and large correlations between V2-skating and running (r = 0.53) and double poling and running (r = 0.58). There were trivial to moderate correlations between exercise economy and the intrinsic factors VO2peak (r = 0.00–0.23), cycle rate (r = 0.03–0.46), body mass (r = −0.09–0.46) and body height (r = 0.11–0.36). In conclusion, the inter-individual variation in exercise economy could be explained only moderately by differences in VO2peak, body mass and body height. Apparently other intrinsic factors contribute to the variation in exercise economy between highly trained subjects. PMID:24478718

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

Steiner, Andrew W.; Lattimer, James M.; Brown, Edward F.

We investigate constraints on neutron star structure arising from the assumptions that neutron stars have crusts, that recent calculations of pure neutron matter limit the equation of state of neutron star matter near the nuclear saturation density, that the high-density equation of state is limited by causality and the largest high-accuracy neutron star mass measurement, and that general relativity is the correct theory of gravity. We explore the role of prior assumptions by considering two classes of equation of state models. In a first, the intermediate- and high-density behavior of the equation of state is parameterized by piecewise polytropes. Inmore » the second class, the high-density behavior of the equation of state is parameterized by piecewise continuous line segments. The smallest density at which high-density matter appears is varied in order to allow for strong phase transitions above the nuclear saturation density. We critically examine correlations among the pressure of matter, radii, maximum masses, the binding energy, the moment of inertia, and the tidal deformability, paying special attention to the sensitivity of these correlations to prior assumptions about the equation of state. It is possible to constrain the radii of 1.4 solar mass neutron stars to be larger than 10 km, even without consideration of additional astrophysical observations, for example, those from photospheric radius expansion bursts or quiescent low-mass X-ray binaries. We are able to improve the accuracy of known correlations between the moment of inertia and compactness as well as the binding energy and compactness. Furthermore, we also demonstrate the existence of a correlation between the neutron star binding energy and the moment of inertia.« less

Correlated Topic Vector for Scene Classification.

PubMed

Wei, Pengxu; Qin, Fei; Wan, Fang; Zhu, Yi; Jiao, Jianbin; Ye, Qixiang

2017-07-01

Scene images usually involve semantic correlations, particularly when considering large-scale image data sets. This paper proposes a novel generative image representation, correlated topic vector, to model such semantic correlations. Oriented from the correlated topic model, correlated topic vector intends to naturally utilize the correlations among topics, which are seldom considered in the conventional feature encoding, e.g., Fisher vector, but do exist in scene images. It is expected that the involvement of correlations can increase the discriminative capability of the learned generative model and consequently improve the recognition accuracy. Incorporated with the Fisher kernel method, correlated topic vector inherits the advantages of Fisher vector. The contributions to the topics of visual words have been further employed by incorporating the Fisher kernel framework to indicate the differences among scenes. Combined with the deep convolutional neural network (CNN) features and Gibbs sampling solution, correlated topic vector shows great potential when processing large-scale and complex scene image data sets. Experiments on two scene image data sets demonstrate that correlated topic vector improves significantly the deep CNN features, and outperforms existing Fisher kernel-based features.

Voluntary Movement Frequencies in Submaximal One- and Two-Legged Knee Extension Exercise and Pedaling

PubMed Central

Stang, Julie; Wiig, Håvard; Hermansen, Marte; Hansen, Ernst Albin

2016-01-01

Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n = 16, thereof eight women; 23.4 ± 2.7 years; 1.70 ± 0.11 m; 68.6 ± 11.2 kg). High and fair correlations (R-values of 0.99 and 0.75) occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95) occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence. The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs) of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs appeared to be stronger for the relatively simple single-joint activity of knee extension exercise as compared to the more complex multi-joint activity of pedaling. Finally, it appeared that the shared aspect of knee extension in the related types of activities of knee extension exercise and pedaling was insufficient to cause obvious correlations between generated movement frequencies in the two types of activities. PMID:26973486

A powerful score-based test statistic for detecting gene-gene co-association.

PubMed

Xu, Jing; Yuan, Zhongshang; Ji, Jiadong; Zhang, Xiaoshuai; Li, Hongkai; Wu, Xuesen; Xue, Fuzhong; Liu, Yanxun

2016-01-29

The genetic variants identified by Genome-wide association study (GWAS) can only account for a small proportion of the total heritability for complex disease. The existence of gene-gene joint effects which contains the main effects and their co-association is one of the possible explanations for the "missing heritability" problems. Gene-gene co-association refers to the extent to which the joint effects of two genes differ from the main effects, not only due to the traditional interaction under nearly independent condition but the correlation between genes. Generally, genes tend to work collaboratively within specific pathway or network contributing to the disease and the specific disease-associated locus will often be highly correlated (e.g. single nucleotide polymorphisms (SNPs) in linkage disequilibrium). Therefore, we proposed a novel score-based statistic (SBS) as a gene-based method for detecting gene-gene co-association. Various simulations illustrate that, under different sample sizes, marginal effects of causal SNPs and co-association levels, the proposed SBS has the better performance than other existed methods including single SNP-based and principle component analysis (PCA)-based logistic regression model, the statistics based on canonical correlations (CCU), kernel canonical correlation analysis (KCCU), partial least squares path modeling (PLSPM) and delta-square (δ (2)) statistic. The real data analysis of rheumatoid arthritis (RA) further confirmed its advantages in practice. SBS is a powerful and efficient gene-based method for detecting gene-gene co-association.

Validation of a novel computer-assisted sperm analysis (CASA) system using multitarget-tracking algorithms.

PubMed

Tomlinson, Mathew James; Pooley, Karen; Simpson, Tracey; Newton, Thomas; Hopkisson, James; Jayaprakasan, Kannamanadias; Jayaprakasan, Rajisha; Naeem, Asad; Pridmore, Tony

2010-04-01

To determine the accuracy and precision of a novel computer-assisted sperm analysis (CASA) system by comparison with existing recommended manual methods. Prospective study using comparative measurements of sperm concentration and motility on latex beads and immotile and motile sperm. Tertiary referral fertility center with strong academic links. Sperm donors and male partners of couples attending for fertility investigations. None. Achievement of Accubead target value for high and low concentration suspensions. Repeatability as demonstrated by coefficients of variation and intraclass correlation coefficients. Correlation and limits of agreement between CASA and manual methods. The CASA measurements of latex beads and sperm concentrations demonstrated a high level of accuracy and repeatability. Repeated Accubead measurements attained the required target value (mean difference from target of 2.61% and 3.71% for high- and low-concentration suspensions, respectively) and were highly reproducible. Limits of agreement analysis suggested that manual and CASA counts compared directly could be deemed to be interchangeable. Manual and CASA motility measurements were highly correlated for grades a, b, and d but could not be deemed to be interchangeable, and manual motility estimates were consistently higher for motile sperm. The novel CASA system was able to provide semen quality measurements for sperm concentration and motility measurements which were at least as reliable as current manual methods. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Novel method for fog monitoring using cellular networks infrastructures

NASA Astrophysics Data System (ADS)

David, N.; Alpert, P.; Messer, H.

2012-08-01

A major detrimental effect of fog is visibility limitation which can result in serious transportation accidents, traffic delays and therefore economic damage. Existing monitoring techniques including satellites, transmissometers and human observers - suffer from low spatial resolution, high cost or lack of precision when measuring near ground level. Here we show a novel technique for fog monitoring using wireless communication systems. Communication networks widely deploy commercial microwave links across the terrain at ground level. Operating at frequencies of tens of GHz they are affected by fog and are, effectively, an existing, spatially world-wide distributed sensor network that can provide crucial information about fog concentration and visibility. Fog monitoring potential is demonstrated for a heavy fog event that took place in Israel. The correlation between transmissomters and human eye observations to the visibility estimates from the nearby microwave links was found to be 0.53 and 0.61, respectively. These values indicate the high potential of the proposed method.

Floquet prethermalization in the resonantly driven Hubbard model

NASA Astrophysics Data System (ADS)

Herrmann, Andreas; Murakami, Yuta; Eckstein, Martin; Werner, Philipp

2017-12-01

We demonstrate the existence of long-lived prethermalized states in the Mott insulating Hubbard model driven by periodic electric fields. These states, which also exist in the resonantly driven case with a large density of photo-induced doublons and holons, are characterized by a nonzero current and an effective temperature of the doublons and holons which depends sensitively on the driving condition. Focusing on the specific case of resonantly driven models whose effective time-independent Hamiltonian in the high-frequency driving limit corresponds to noninteracting fermions, we show that the time evolution of the double occupation can be reproduced by the effective Hamiltonian, and that the prethermalization plateaus at finite driving frequency are controlled by the next-to-leading-order correction in the high-frequency expansion of the effective Hamiltonian. We propose a numerical procedure to determine an effective Hubbard interaction that mimics the correlation effects induced by these higher-order terms.

Ortho-para-hydrogen equilibration on Jupiter

NASA Technical Reports Server (NTRS)

Carlson, Barbara E.; Lacis, Andrew A.; Rossow, William B.

1992-01-01

Voyager IRIS observations reveal that the Jovian para-hydrogen fraction is not in thermodynamic equilibrium near the NH3 cloud top, implying that a vertical gradient exists between the high-temperature equilibrium value of 0.25 at depth and the cloud top values. The height-dependent para-hydrogen profile is obtained using an anisotropic multiple-scattering radiative transfer model. A vertical correlation is found to exist between the location of the para-hydrogen gradient and the NH3 cloud, strongly suggesting that paramagnetic conversion on NH3 cloud particle surfaces is the dominant equilibration mechanism. Below the NH3 cloud layer, the para fraction is constant with depth and equal to the high-temperature equilibrium value of 0.25. The degree of cloud-top equilibration appears to depend on the optical depth of the NH3 cloud layer. Belt-zone variations in the para-hydrogen profile seem to be due to differences in the strength of the vertical mixing.

A novel secret sharing with two users based on joint transform correlator and compressive sensing

NASA Astrophysics Data System (ADS)

Zhao, Tieyu; Chi, Yingying

2018-05-01

Recently, joint transform correlator (JTC) has been widely applied to image encryption and authentication. This paper presents a novel secret sharing scheme with two users based on JTC. Two users must be present during the decryption that the system has high security and reliability. In the scheme, two users use their fingerprints to encrypt plaintext, and they can decrypt only if both of them provide the fingerprints which are successfully authenticated. The linear relationship between the plaintext and ciphertext is broken using the compressive sensing, which can resist existing attacks on JTC. The results of the theoretical analysis and numerical simulation confirm the validity of the system.

Correlation of unsupported ²¹⁰Pb activity in soil and moss.

PubMed

Krmar, M; Radnović, D; Hansman, J

2014-03-01

The activities of unsupported (210)Pb, a naturally occurring radionuclide, were measured in samples of soil and terrestrial mosses collected in Serbia. Considering that clay particles in soil have a high affinity for Pb adsorption, and that mosses usually capture aerosol particles to obtain necessary nutrients, measurable amounts of airborne (210)Pb, the daughter of (222)Rn, can be registered in both soil and mosses. The objective of the present study was to determine if it is possible to compare the activity of unsupported (210)Pb in soil and moss collected at the same sampling site, and to establish if a correlation exists between these measured values. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnetic Spin Correlations in the One-dimensional Frustrated Spin-chain System Ca3Co2O6

NASA Astrophysics Data System (ADS)

Månsson, M.; Sugiyama, J.; Roessli, B.; Hitti, B.; Ikedo, Y.; Zivkovic, I.; Nozaki, H.; Harada, M.; Sassa, Y.; Andreica, D.; Goko, T.; Amato, A.; Ofer, O.; Ansaldo, E. J.; Brewer, J. H.; Chow, K. H.; Yi, H. T.; Cheong, S.-W.; Prsa, K.

In this work we present a combination of zero-field and high transverse-field muon spin rotation/relaxation (μ+SR) measurements. The current μ+SR Knight-shift measurements clearly shows that Ca3Co2O6 display strong spin correlations even at room-temperature. Further, several anomalies in the temperature dependent data are proposed to be connected to the onset of a quasi-one-dimensional (Q1D) ferrimagnetic order. Further, we suggest that in the low-temperature regime, the Q1D ferrimagnetic order co-exist within a long-range antiferromagnetic phase, which has been confirmed by our recent neutron scattering studies.

Authoritarianism, dominance and assertiveness.

PubMed

Ray, J J

1981-08-01

It is shown that there are definitions of the three constructs of authoritarianism, dominance and assertiveness which read very similarly; so much so that no distinction is immediately evident. It is proposed that authoritarianism might be conceived as aggressive dominance and at least some types of assertiveness as nonaggressive dominance. A new scale of Dominance suitable for general population use was produced, and compared with the existing Ray (1976) behavior inventory of authoritarianism. Both scales showed highly significant correlations with peer rated dominance and submission (the latter being negative in sign) but only the authoritarianism scale showed significant correlations with rated aggressiveness and rigidity. It was concluded that the new definitions could be operationalized into valid scales.

LES, DNS, and RANS for the Analysis of High-Speed Turbulent Reacting Flows

NASA Technical Reports Server (NTRS)

Colucci, P. J.; Jaberi, F. A.; Givi, P.

1996-01-01

A filtered density function (FDF) method suitable for chemically reactive flows is developed in the context of large eddy simulation. The advantage of the FDF methodology is its inherent ability to resolve subgrid scales (SGS) scalar correlations that otherwise have to be modeled. Because of the lack of robust models to accurately predict these correlations in turbulent reactive flows, simulations involving turbulent combustion are often met with a degree of skepticism. The FDF methodology avoids the closure problem associated with these terms and treats the reaction in an exact manner. The scalar FDF approach is particularly attractive since it can be coupled with existing hydrodynamic computational fluid dynamics (CFD) codes.

Hope Matters: Developing and Validating a Measure of Future Expectations Among Young Women in a High HIV Prevalence Setting in Rural South Africa (HPTN 068).

PubMed

Abler, Laurie; Hill, Lauren; Maman, Suzanne; DeVellis, Robert; Twine, Rhian; Kahn, Kathleen; MacPhail, Catherine; Pettifor, Audrey

2017-07-01

Hope is a future expectancy characterized by an individual's perception that a desirable future outcome can be achieved. Though scales exist to measure hope, they may have limited relevance in low resource, high HIV prevalence settings. We developed and validated a hope scale among young women living in rural South Africa. We conducted formative interviews to identify the key elements of hope. Using items developed from these interviews, we administered the hope scale to 2533 young women enrolled in an HIV-prevention trial. Women endorsed scale items highly and the scale proved to be unidimensional in the sample. Hope scores were significantly correlated with hypothesized psycholosocial correlates with the exception of life stressors. Overall, our hope measure was found to have excellent reliability and to show encouraging preliminary indications of validity in this population. This study presents a promising measure to assess hope among young women in South Africa.

Hope Matters: Developing and Validating a Measure of Future Expectations Among Young Women in a High HIV Prevalence Setting in Rural South Africa (HPTN 068)

PubMed Central

Abler, Laurie; Maman, Suzanne; DeVellis, Robert; Twine, Rhian; Kahn, Kathleen; MacPhail, Catherine; Pettifor, Audrey

2017-01-01

Hope is a future expectancy characterized by an individual’s perception that a desirable future outcome can be achieved. Though scales exist to measure hope, they may have limited relevance in low resource, high HIV prevalence settings. We developed and validated a hope scale among young women living in rural South Africa. We conducted formative interviews to identify the key elements of hope. Using items developed from these interviews, we administered the hope scale to 2533 young women enrolled in an HIV-prevention trial. Women endorsed scale items highly and the scale proved to be unidimensional in the sample. Hope scores were significantly correlated with hypothesized psycholosocial correlates with the exception of life stressors. Overall, our hope measure was found to have excellent reliability and to show encouraging preliminary indications of validity in this population. This study presents a promising measure to assess hope among young women in South Africa. PMID:27544516

Modeling long correlation times using additive binary Markov chains: Applications to wind generation time series.

PubMed

Weber, Juliane; Zachow, Christopher; Witthaut, Dirk

2018-03-01

Wind power generation exhibits a strong temporal variability, which is crucial for system integration in highly renewable power systems. Different methods exist to simulate wind power generation but they often cannot represent the crucial temporal fluctuations properly. We apply the concept of additive binary Markov chains to model a wind generation time series consisting of two states: periods of high and low wind generation. The only input parameter for this model is the empirical autocorrelation function. The two-state model is readily extended to stochastically reproduce the actual generation per period. To evaluate the additive binary Markov chain method, we introduce a coarse model of the electric power system to derive backup and storage needs. We find that the temporal correlations of wind power generation, the backup need as a function of the storage capacity, and the resting time distribution of high and low wind events for different shares of wind generation can be reconstructed.

Modeling long correlation times using additive binary Markov chains: Applications to wind generation time series

NASA Astrophysics Data System (ADS)

Weber, Juliane; Zachow, Christopher; Witthaut, Dirk

2018-03-01

Wind power generation exhibits a strong temporal variability, which is crucial for system integration in highly renewable power systems. Different methods exist to simulate wind power generation but they often cannot represent the crucial temporal fluctuations properly. We apply the concept of additive binary Markov chains to model a wind generation time series consisting of two states: periods of high and low wind generation. The only input parameter for this model is the empirical autocorrelation function. The two-state model is readily extended to stochastically reproduce the actual generation per period. To evaluate the additive binary Markov chain method, we introduce a coarse model of the electric power system to derive backup and storage needs. We find that the temporal correlations of wind power generation, the backup need as a function of the storage capacity, and the resting time distribution of high and low wind events for different shares of wind generation can be reconstructed.

Detection of surface impurity phases in high T.sub.C superconductors using thermally stimulated luminescence

DOEpatents

Cooke, D. Wayne; Jahan, Muhammad S.

1989-01-01

Detection of surface impurity phases in high-temperature superconducting materials. Thermally stimulated luminescence has been found to occur in insulating impurity phases which commonly exist in high-temperature superconducting materials. The present invention is sensitive to impurity phases occurring at a level of less than 1% with a probe depth of about 1 .mu.m which is the region of interest for many superconductivity applications. Spectroscopic and spatial resolution of the emitted light from a sample permits identification and location of the impurity species. Absence of luminescence, and thus of insulating phases, can be correlated with low values of rf surface resistance.

Uncertainty Analysis on Heat Transfer Correlations for RP-1 Fuel in Copper Tubing

NASA Technical Reports Server (NTRS)

Driscoll, E. A.; Landrum, D. B.

2004-01-01

NASA is studying kerosene (RP-1) for application in Next Generation Launch Technology (NGLT). Accurate heat transfer correlations in narrow passages at high temperatures and pressures are needed. Hydrocarbon fuels, such as RP-1, produce carbon deposition (coke) along the inside of tube walls when heated to high temperatures. A series of tests to measure the heat transfer using RP-1 fuel and examine the coking were performed in NASA Glenn Research Center's Heated Tube Facility. The facility models regenerative cooling by flowing room temperature RP-1 through resistively heated copper tubing. A Regression analysis is performed on the data to determine the heat transfer correlation for Nusselt number as a function of Reynolds and Prandtl numbers. Each measurement and calculation is analyzed to identify sources of uncertainty, including RP-1 property variations. Monte Carlo simulation is used to determine how each uncertainty source propagates through the regression and an overall uncertainty in predicted heat transfer coefficient. The implications of these uncertainties on engine design and ways to minimize existing uncertainties are discussed.

Psychometric evaluation of a daily gastro-oesophageal reflux disease symptom measure.

PubMed

Bytzer, Peter; Reimer, Christina; Smith, Gary; Anatchkova, Milena D; Hsieh, Ray; Wilkinson, Joanne; Thomas, S Jane; Lenderking, William R

2017-03-01

The objective of this study was to evaluate the validity of the Heartburn Reflux Dyspepsia Questionnaire (HRDQ), a newly developed measure of gastro-oesophageal reflux disease (GORD) symptoms. Specifically, the HRDQ was developed for patients, who still experience symptoms with proton pump inhibitor (PPI) treatment. The psychometric properties of HRDQ were evaluated based on data from two clinical trials of patients with GORD with a partial response to PPIs, one from the UK and one from Denmark and Germany. The HRDQ had good internal consistency (Cronbach's alpha range .83-.88) and test-retest reliability (intraclass correlation coefficient range .71-.90). Convergent and discriminant validity were supported by high correlations with ReQuest™ and ability to differentiate between groups based on ReQuest™ cut-off values. Responsiveness of HRDQ was demonstrated by moderate to high correlations with ReQuest™ change scores and time with symptoms. An HRDQ cut-off value of 0.70 for definition of 'bad day' was also evaluated. Based on existing evidence, the HRDQ is a valid and reliable measure of GORD symptoms that can be used as a study outcome in clinical trials.

Nearshore shore-oblique bars, gravel outcrops, and their correlation to shoreline change

USGS Publications Warehouse

Schupp, C.A.; McNinch, J.E.; List, J.H.

2006-01-01

This study demonstrates the physical concurrence of shore-oblique bars and gravel outcrops in the surf zone along the northern Outer Banks of North Carolina. These subaqueous features are spatially correlated with shoreline change at a range of temporal and spatial scales. Previous studies have noted the existence of beach-surf zone interactions, but in general, relationships between nearshore geological features and coastal change are poorly understood. These new findings should be considered when exploring coastal zone dynamics and developing predictive engineering models.The surf zone and nearshore region of the Outer Banks is predominantly planar and sandy, but there are several discrete regions with shore-oblique bars and interspersed gravel outcrops. These bar fields have relief up to 3 m, are several kilometers wide, and were relatively stationary over a 1.5 year survey period; however, the shoreward component of the bar field does exhibit change during this time frame. All gravel outcrops observed in the study region, a 40 km longshore length, were located adjacent to a shore-oblique bar, in a trough that had width and length similar to that of the associated bar. Seismic surveys show that the outcrops are part of a gravel stratum underlying the active surface sand layer.Cross-correlation analyses demonstrate high correlation of monthly and multi-decadal shoreline change rates with the adjacent surf-zone bathymetry and sediment distribution. Regionally, areas with shore-oblique bars and gravel outcrops are correlated with on-shore areas of high short-term shoreline variability and high long-term shoreline change rates. The major peaks in long-term shoreline erosion are onshore of shore-oblique bars, but not all areas with high rates of long-term shoreline change are associated with shore-oblique bars and troughs.

The IR properties of ringed galaxies and the IRAS database

NASA Technical Reports Server (NTRS)

Buta, Ronald J.; Crocker, Deborah A.

1993-01-01

Our study of the Infrared Astronomy Satellite (IRAS) properties of ringed galaxies has been largely successful. We have identified what we think is the probable cause of the differences in the IRAS properties among non-interacting barred galaxies as the pattern speed of the bar. The key to identifying this parameter has been our focusing the study on outer-ringed galaxies where we know precisely what is present in the central regions (from available BVI CCD images in our library of images). The theory is that outer rings, through their morphology and other characteristics, can be identified with the outer Lindblad resonance, one of the major resonances in galaxy structure. Using a library of n-body simulations for comparison, we can reliably infer both low and high pattern speed galaxies from the appearance of outer rings and the existence of other ring features. It is clear that in some barred galaxies, the bar pattern speed is high enough to avoid an inner Lindblad resonance, hence such objects do not contain nuclear or circumnuclear star formation. The IRAS observations are most sensitive to nuclear star formation in early-type barred galaxies, and will thus select those barred galaxies where the pattern speed is low enough to allow an inner Lindblad resonance to exist. High pattern speed barred galaxies therefore weaken the correlation between bars and infrared excess. This finding helps to reconcile the inconsistent results found between different studies on the correlation between bars and far-IR emission.

A distributed network of low-cost continuous reading sensors to measure spatiotemporal variations of PM2.5 in Xi'an, China.

PubMed

Gao, Meiling; Cao, Junji; Seto, Edmund

2015-04-01

Fine particulate matter (PM2.5) is a growing public health concern especially in industrializing countries but existing monitoring networks are unable to properly characterize human exposures due to low resolution spatiotemporal data. Low-cost portable monitors can supplement existing networks in both developed and industrializing regions to increase density of sites and data. This study tests the performance of a low-cost sensor in high concentration urban environments. Seven Portable University of Washington Particle (PUWP) monitors were calibrated with optical and gravimetric PM2.5 reference monitors in Xi'an, China in December 2013. Pairwise correlations between the raw PUWP and the reference monitors were high (R(2) = 0.86-0.89). PUWP monitors were also simultaneously deployed at eight sites across Xi'an alongside gravimetric PM2.5 monitors (R(2) = 0.53). The PUWP monitors were able to identify the High-technology Zone site as a potential PM2.5 hotspot with sustained high concentrations compared to the city average throughout the day. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Correlation of causal factors that influence construction safety performance: A model.

PubMed

Rodrigues, F; Coutinho, A; Cardoso, C

2015-01-01

The construction sector has presented positive development regarding the decrease in occupational accident rates in recent years. Regardless, the construction sector stands out systematically from other industries due to its high number of fatalities. The aim of this paper is to deeply understand the causality of construction accidents from the early design phase through a model. This study reviewed several research papers presenting various analytical models that correlate the contributing factors to occupational accidents in this sector. This study also analysed different construction projects and conducted a survey of design and site supervision teams. This paper proposes a model developed from the analysis of existing ones, which correlates the causal factors through all the construction phases. It was concluded that effective risk prevention can only be achieved by a global correlation of causal factors including not only production ones but also client requirements, financial climate, design team competence, project and risk management, financial capacity, health and safety policy and early planning. Accordingly, a model is proposed.

Decadal predictability of river discharge with climate oscillations over the 20th and early 21st century

NASA Astrophysics Data System (ADS)

Wanders, Niko; Wada, Yoshihide

2015-12-01

Long-term hydrological forecasts are important to increase our resilience and preparedness to extreme hydrological events. The skill in these forecasts is still limited due to large uncertainties inherent in hydrological models and poor predictability of long-term meteorological conditions. Here we show that strong (lagged) correlations exist between four different major climate oscillation modes and modeled and observed discharge anomalies over a 100 year period. The strongest correlations are found between the El Niño-Southern Oscillation signal and river discharge anomalies all year round, while North Atlantic Oscillation and Antarctic Oscillation time series are strongly correlated with winter discharge anomalies. The correlation signal is significant for periods up to 5 years for some regions, indicating a high added value of this information for long-term hydrological forecasting. The results suggest that long-term hydrological forecasting could be significantly improved by including the climate oscillation signals and thus improve our preparedness for hydrological extremes in the near future.

Low temperature spalling of silicon: A crack propagation study

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

Bertoni, Mariana; Uberg Naerland, Tine; Stoddard, Nathan

2017-06-08

Spalling is a promising kerfless method for cutting thin silicon wafers while doubling the yield of a silicon ingot. The main obstacle in this technology is the high total thickness variation of the spalled wafers, often as high as 100% of the wafer thickness. It has been suggested before that a strong correlation exists between low crack velocities and a smooth surface, but this correlation has never been shown during a spalling process in silicon. The reason lies in the challenge associated to measuring such velocities. In this contribution, we present a new approach to assess, in real time, themore » crack velocity as it propagates during a low temperature spalling process. Understanding the relationship between crack velocity and surface roughness during spalling can pave the way to attain full control on the surface quality of the spalled wafer.« less

Local visual perception bias in children with high-functioning autism spectrum disorders; do we have the whole picture?

PubMed

Falkmer, Marita; Black, Melissa; Tang, Julia; Fitzgerald, Patrick; Girdler, Sonya; Leung, Denise; Ordqvist, Anna; Tan, Tele; Jahan, Ishrat; Falkmer, Torbjorn

2016-01-01

While local bias in visual processing in children with autism spectrum disorders (ASD) has been reported to result in difficulties in recognizing faces and facially expressed emotions, but superior ability in disembedding figures, associations between these abilities within a group of children with and without ASD have not been explored. Possible associations in performance on the Visual Perception Skills Figure-Ground test, a face recognition test and an emotion recognition test were investigated within 25 8-12-years-old children with high-functioning autism/Asperger syndrome, and in comparison to 33 typically developing children. Analyses indicated a weak positive correlation between accuracy in Figure-Ground recognition and emotion recognition. No other correlation estimates were significant. These findings challenge both the enhanced perceptual function hypothesis and the weak central coherence hypothesis, and accentuate the importance of further scrutinizing the existance and nature of local visual bias in ASD.

Online blind source separation using incremental nonnegative matrix factorization with volume constraint.

PubMed

Zhou, Guoxu; Yang, Zuyuan; Xie, Shengli; Yang, Jun-Mei

2011-04-01

Online blind source separation (BSS) is proposed to overcome the high computational cost problem, which limits the practical applications of traditional batch BSS algorithms. However, the existing online BSS methods are mainly used to separate independent or uncorrelated sources. Recently, nonnegative matrix factorization (NMF) shows great potential to separate the correlative sources, where some constraints are often imposed to overcome the non-uniqueness of the factorization. In this paper, an incremental NMF with volume constraint is derived and utilized for solving online BSS. The volume constraint to the mixing matrix enhances the identifiability of the sources, while the incremental learning mode reduces the computational cost. The proposed method takes advantage of the natural gradient based multiplication updating rule, and it performs especially well in the recovery of dependent sources. Simulations in BSS for dual-energy X-ray images, online encrypted speech signals, and high correlative face images show the validity of the proposed method.

Large-scale coherent structures of suspended dust concentration in the neutral atmospheric surface layer: A large-eddy simulation study

NASA Astrophysics Data System (ADS)

Zhang, Yangyue; Hu, Ruifeng; Zheng, Xiaojing

2018-04-01

Dust particles can remain suspended in the atmospheric boundary layer, motions of which are primarily determined by turbulent diffusion and gravitational settling. Little is known about the spatial organizations of suspended dust concentration and how turbulent coherent motions contribute to the vertical transport of dust particles. Numerous studies in recent years have revealed that large- and very-large-scale motions in the logarithmic region of laboratory-scale turbulent boundary layers also exist in the high Reynolds number atmospheric boundary layer, but their influence on dust transport is still unclear. In this study, numerical simulations of dust transport in a neutral atmospheric boundary layer based on an Eulerian modeling approach and large-eddy simulation technique are performed to investigate the coherent structures of dust concentration. The instantaneous fields confirm the existence of very long meandering streaks of dust concentration, with alternating high- and low-concentration regions. A strong negative correlation between the streamwise velocity and concentration and a mild positive correlation between the vertical velocity and concentration are observed. The spatial length scales and inclination angles of concentration structures are determined, compared with their flow counterparts. The conditionally averaged fields vividly depict that high- and low-concentration events are accompanied by a pair of counter-rotating quasi-streamwise vortices, with a downwash inside the low-concentration region and an upwash inside the high-concentration region. Through the quadrant analysis, it is indicated that the vertical dust transport is closely related to the large-scale roll modes, and ejections in high-concentration regions are the major mechanisms for the upward motions of dust particles.

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

PubMed

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

2014-01-01

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

Detection of Nitrogen Content in Rubber Leaves Using Near-Infrared (NIR) Spectroscopy with Correlation-Based Successive Projections Algorithm (SPA).

PubMed

Tang, Rongnian; Chen, Xupeng; Li, Chuang

2018-05-01

Near-infrared spectroscopy is an efficient, low-cost technology that has potential as an accurate method in detecting the nitrogen content of natural rubber leaves. Successive projections algorithm (SPA) is a widely used variable selection method for multivariate calibration, which uses projection operations to select a variable subset with minimum multi-collinearity. However, due to the fluctuation of correlation between variables, high collinearity may still exist in non-adjacent variables of subset obtained by basic SPA. Based on analysis to the correlation matrix of the spectra data, this paper proposed a correlation-based SPA (CB-SPA) to apply the successive projections algorithm in regions with consistent correlation. The result shows that CB-SPA can select variable subsets with more valuable variables and less multi-collinearity. Meanwhile, models established by the CB-SPA subset outperform basic SPA subsets in predicting nitrogen content in terms of both cross-validation and external prediction. Moreover, CB-SPA is assured to be more efficient, for the time cost in its selection procedure is one-twelfth that of the basic SPA.

Factors that influence utilisation of HIV/AIDS prevention methods among university students residing at a selected university campus.

PubMed

Ndabarora, Eléazar; Mchunu, Gugu

2014-01-01

Various studies have reported that university students, who are mostly young people, rarely use existing HIV/AIDS preventive methods. Although studies have shown that young university students have a high degree of knowledge about HIV/AIDS and HIV modes of transmission, they are still not utilising the existing HIV prevention methods and still engage in risky sexual practices favourable to HIV. Some variables, such as awareness of existing HIV/AIDS prevention methods, have been associated with utilisation of such methods. The study aimed to explore factors that influence use of existing HIV/AIDS prevention methods among university students residing in a selected campus, using the Health Belief Model (HBM) as a theoretical framework. A quantitative research approach and an exploratory-descriptive design were used to describe perceived factors that influence utilisation by university students of HIV/AIDS prevention methods. A total of 335 students completed online and manual questionnaires. Study findings showed that the factors which influenced utilisation of HIV/AIDS prevention methods were mainly determined by awareness of the existing university-based HIV/AIDS prevention strategies. Most utilised prevention methods were voluntary counselling and testing services and free condoms. Perceived susceptibility and perceived threat of HIV/AIDS score was also found to correlate with HIV risk index score. Perceived susceptibility and perceived threat of HIV/AIDS showed correlation with self-efficacy on condoms and their utilisation. Most HBM variables were not predictors of utilisation of HIV/AIDS prevention methods among students. Intervention aiming to improve the utilisation of HIV/AIDS prevention methods among students at the selected university should focus on removing identified barriers, promoting HIV/AIDS prevention services and providing appropriate resources to implement such programmes.

Fingerprint Changes in Coeliac Disease

PubMed Central

David, T. J.; Ajdukiewicz, A. B.; Read, A. E.

1970-01-01

Study of the fingerprints of 73 patients with coeliac disease, taken carefully, showed changes varying between moderate epidermal ridge atrophy and actual loss of fingerprint patterns. Of the patients 63 had these abnormalities, compared with 3 out of 485 controls. A high degree of correlation existed between ridge atrophy and changes in the clinical state of patients with coeliac disease. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:5488703

High-resolution maps of Jupiter at five microns.

NASA Technical Reports Server (NTRS)

Keay, C. S. L.; Low, F. J.; Rieke, G. H.; Minton, R. B.

1973-01-01

The distribution of 5-micron radiation, emitted from a large number of discrete sources from Jupiter, was observed during the 1972 apparition. These sources are less bright than those observed by Westphal (1969). At least 50 discrete sources having brightness temperatures exceeding 227 K were revealed which were mainly located within three narrow-latitude bands. Strong correlation exists between the 5-micron brightness temperatures of Jovian features and their colors as recorded photographically.

Use of international foundations of medicine clinical sciences examination to evaluate students' performance in the local examination at the University of Sharjah, United Arab Emirates.

PubMed

Dash, Nihar Ranjan; Abdalla, Mohamed Elhassan; Hussein, Amal

2017-01-01

Several medical schools around the world are moving away from isolated, locally developed in-house assessments to the introduction of external examinations into their curriculum. Although the objective varies, it is typically done to evaluate, audit, and compare students' performance to international standards. Similarly, the International Foundations of Medicine-Clinical Sciences Examination (IFOM-CSE) was introduced in the College of Medicine at the University of Sharjah as an external assessment criterion in addition to the existing in-house assessments. The aim of this study was to compare the student performance in this newly introduced IFOM-CSE examination and the existing in-house final examination in the college. The scores of three consecutive final-year undergraduate medical student batches (2013-2015) who took both the IFOM-CSE and the existing in-house final examination were analyzed. Pearson correlation and one-way analysis of variance test were conducted using SPSS 22. The students' scores in the IFOM-CSE and in the final examination prepared locally were highly correlated with Pearson correlation coefficients of 0.787 for batch 2013, 0.827 for batch 2014, and 0.830 for batch 2015 (P < 0.0005). Interestingly, while the mean scores of the IFOM-CSE among the three batches in the years 2013, 2014, and 2015 (475, 492, and 513, respectively) showed improvement with borderline significance (F[2226] = 2.73, P = 0.067), local examination scores showed a significant improvement during the study period (F[2277] = 52.87, P < 0.0005). The findings of this study showed that students' scores in the local examination were consistently correlated with their scores in the IFOM-CSE over all the three batches. Thus, introduction of external examination can be an important evaluation tool to a comprehensive internal assessment system providing evidence of external validity.

Collective Dynamics of Specific Gene Ensembles Crucial for Neutrophil Differentiation: The Existence of Genome Vehicles Revealed

PubMed Central

Giuliani, Alessandro; Tomita, Masaru

2010-01-01

Cell fate decision remarkably generates specific cell differentiation path among the multiple possibilities that can arise through the complex interplay of high-dimensional genome activities. The coordinated action of thousands of genes to switch cell fate decision has indicated the existence of stable attractors guiding the process. However, origins of the intracellular mechanisms that create “cellular attractor” still remain unknown. Here, we examined the collective behavior of genome-wide expressions for neutrophil differentiation through two different stimuli, dimethyl sulfoxide (DMSO) and all-trans-retinoic acid (atRA). To overcome the difficulties of dealing with single gene expression noises, we grouped genes into ensembles and analyzed their expression dynamics in correlation space defined by Pearson correlation and mutual information. The standard deviation of correlation distributions of gene ensembles reduces when the ensemble size is increased following the inverse square root law, for both ensembles chosen randomly from whole genome and ranked according to expression variances across time. Choosing the ensemble size of 200 genes, we show the two probability distributions of correlations of randomly selected genes for atRA and DMSO responses overlapped after 48 hours, defining the neutrophil attractor. Next, tracking the ranked ensembles' trajectories, we noticed that only certain, not all, fall into the attractor in a fractal-like manner. The removal of these genome elements from the whole genomes, for both atRA and DMSO responses, destroys the attractor providing evidence for the existence of specific genome elements (named “genome vehicle”) responsible for the neutrophil attractor. Notably, within the genome vehicles, genes with low or moderate expression changes, which are often considered noisy and insignificant, are essential components for the creation of the neutrophil attractor. Further investigations along with our findings might provide a comprehensive mechanistic view of cell fate decision. PMID:20725638

Dynamics and Energetics of Deformable Evaporating Droplets at Intermediate Reynolds Numbers.

NASA Astrophysics Data System (ADS)

Haywood, Ross Jeffrey

The behaviour of vaporizing droplets, representative of droplets present in hydrocarbon fuel sprays, has been investigated. A finite volume numerical model using a non-orthogonal, adaptive grid has been developed to examine both steady deformed and transient deforming droplet behaviour. Computations are made of the shapes of, and the velocity, pressure, temperature and concentration fields around and within n-heptane droplets evaporating in high temperature air environments at intermediate Reynolds and Weber numbers (10 <= Re <= 100, We <= 10). The numerical model has been rigorously tested by comparison with existing theoretical and numerical solutions and experimental data for problems of intermediate Reynolds number flows over spheroids, inviscid deforming droplets, viscous oscillating droplets, and transient deforming liquid droplets subjected to electrostatic fields. Computations show steady deformed droplets assuming oblate shapes with major axes perpendicular to the mean flow direction. When based on volume equivalent diameters, existing quasi-steady correlations of Nusselt and Sherwood numbers (Renksizbulut and Yuen (1983), Haywood et al. (1989), and Renksizbulut et al. (1991)) for spherical droplets are in good agreement with the numerical results. Providing they are based on actual frontal area, the computed drag coefficients are also reasonably well predicted by the existing quasi-steady drag correlation (Haywood et al. (1989), Renksizbulut and Yuen (1983)). A new correlation is developed for the total drag coefficient of quasi-steady deformed vaporizing droplets. The computed transient histories of droplets injected with an initial Reynolds number of 100 into 1000 K air at 1 and 10 atmospheres ambient pressure show strongly damped initial oscillations at frequencies within 25 percent of the theoretical natural frequency of Lamb (1932). Gas phase shear induced circulation within the droplets is responsible for the observed strong damping and promotes the formation of prolate shapes. The computed rates of heat and mass transfer of transient deforming drops are well predicted by the quasi-steady correlations indicated above.

Identification of sequence motifs significantly associated with antisense activity.

PubMed

McQuisten, Kyle A; Peek, Andrew S

2007-06-07

Predicting the suppression activity of antisense oligonucleotide sequences is the main goal of the rational design of nucleic acids. To create an effective predictive model, it is important to know what properties of an oligonucleotide sequence associate significantly with antisense activity. Also, for the model to be efficient we must know what properties do not associate significantly and can be omitted from the model. This paper will discuss the results of a randomization procedure to find motifs that associate significantly with either high or low antisense suppression activity, analysis of their properties, as well as the results of support vector machine modelling using these significant motifs as features. We discovered 155 motifs that associate significantly with high antisense suppression activity and 202 motifs that associate significantly with low suppression activity. The motifs range in length from 2 to 5 bases, contain several motifs that have been previously discovered as associating highly with antisense activity, and have thermodynamic properties consistent with previous work associating thermodynamic properties of sequences with their antisense activity. Statistical analysis revealed no correlation between a motif's position within an antisense sequence and that sequences antisense activity. Also, many significant motifs existed as subwords of other significant motifs. Support vector regression experiments indicated that the feature set of significant motifs increased correlation compared to all possible motifs as well as several subsets of the significant motifs. The thermodynamic properties of the significantly associated motifs support existing data correlating the thermodynamic properties of the antisense oligonucleotide with antisense efficiency, reinforcing our hypothesis that antisense suppression is strongly associated with probe/target thermodynamics, as there are no enzymatic mediators to speed the process along like the RNA Induced Silencing Complex (RISC) in RNAi. The independence of motif position and antisense activity also allows us to bypass consideration of this feature in the modelling process, promoting model efficiency and reducing the chance of overfitting when predicting antisense activity. The increase in SVR correlation with significant features compared to nearest-neighbour features indicates that thermodynamics alone is likely not the only factor in determining antisense efficiency.

Geographical diffusion of prazosin across Veterans Health Administration: Examination of regional variation in daily dosing and quality indicators among veterans with posttraumatic stress disorder.

PubMed

Abrams, Thad E; Lund, Brian C; Alexander, Bruce; Bernardy, Nancy C; Friedman, Matthew J

2015-01-01

Posttraumatic stress disorder (PTSD) is a high-priority treatment area for the Veterans Health Administration (VHA), and dissemination patterns of innovative, efficacious therapies can inform areas for potential improvement of diffusion efforts and quality prescribing. In this study, we replicated a prior examination of the period prevalence of prazosin use as a function of distance from Puget Sound, Washington, where prazosin was first tested as an effective treatment for PTSD and where prazosin use was previously shown to be much greater than in other parts of the United States. We tested the following three hypotheses related to prazosin geographic diffusion: (1) a positive geographical correlation exists between the distance from Puget Sound and the proportion of users treated according to a guideline recommended minimum therapeutic target dose (>/=6 mg/d), (2) an inverse geographic correlation exists between prazosin and benzodiazepine use, and (3) no geographical correlation exists between prazosin use and serotonin reuptake inhibitor/serotonin norepinephrine reuptake inhibitor (SSRI/SNRI) use. Among a national sample of veterans with PTSD, overall prazosin utilization increased from 5.5 to 14.8% from 2006 to 2012. During this time period, rates at the Puget Sound VHA location declined from 34.4 to 29.9%, whereas utilization rates at locations a minimum of 2,500 miles away increased from 3.0 to 12.8%. Rates of minimum target dosing fell from 42.6 to 34.6% at the Puget Sound location. In contrast, at distances of at least 2,500 miles from Puget Sound, minimum threshold dosing rates remained stable (range, 18.6 to 17.7%). No discernible association was demonstrated between SSRI/SNRI or benzodiazepine utilization and the geographic distance from Puget Sound. Minimal threshold dosing of prazosin correlated positively with increased diffusion of prazosin use, but there was still a distance diffusion gradient. Although prazosin adoption has improved, geographic differences persist in both prescribing rates and minimum target dosing. Importantly, these regional disparities appear to be limited to prazosin prescribing and are not meaningfully correlated with SSRI/SNRI and benzodiazepine use as indicators of PTSD prescribing quality.

Accidental deep field bias in CMB T and SNe z correlation

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Immediate versus delayed intramedullary nailing for open fractures of the tibial shaft: a multivariate analysis of factors affecting deep infection and fracture healing.

PubMed

Yokoyama, Kazuhiko; Itoman, Moritoshi; Uchino, Masataka; Fukushima, Kensuke; Nitta, Hiroshi; Kojima, Yoshiaki

2008-10-01

The purpose of this study was to evaluate contributing factors affecting deep infection and fracture healing of open tibia fractures treated with locked intramedullary nailing (IMN) by multivariate analysis. We examined 99 open tibial fractures (98 patients) treated with immediate or delayed locked IMN in static fashion from 1991 to 2002. Multivariate analyses following univariate analyses were derived to determine predictors of deep infection, nonunion, and healing time to union. The following predictive variables of deep infection were selected for analysis: age, sex, Gustilo type, fracture grade by AO type, fracture location, timing or method of IMN, reamed or unreamed nailing, debridement time (< or =6 h or >6 h), method of soft-tissue management, skin closure time (< or =1 week or >1 week), existence of polytrauma (ISS< 18 or ISS> or =18), existence of floating knee injury, and existence of superficial/pin site infection. The predictive variables of nonunion selected for analysis was the same as those for deep infection, with the addition of deep infection for exchange of pin site infection. The predictive variables of union time selected for analysis was the same as those for nonunion, excluding of location, debridement time, and existence of floating knee and superficial infection. Six (6.1%; type II Gustilo n=1, type IIIB Gustilo n=5) of the 99 open tibial fractures developed deep infections. Multivariate analysis revealed that timing or method of IMN, debridement time, method of soft-tissue management, and existence of superficial or pin site infection significantly correlated with the occurrence of deep infection (P< 0.0001). In the immediate nailing group alone, the deep infection rate in type IIIB + IIIC was significantly higher than those in type I + II and IIIA (P = 0.016). Nonunion occurred in 17 fractures (20.3%, 17/84). Multivariate analysis revealed that Gustilo type, skin closure time, and existence of deep infection significantly correlated with occurrence of nonunion (P < 0.05). Gustilo type and existence of deep infection were significantly correlated with healing time to union on multivariate analysis (r(2) = 0.263, P = 0.0001). Multivariate analyses for open tibial fractures treated with IMN showed that IMN after EF (especially in existence of pin site infection) was at high risk of deep infection, and that debridement within 6 h and appropriate soft-tissue managements were also important factor in preventing deep infections. These analyses postulated that both the Gustilo type and the existence of deep infection is related with fracture healing in open fractures treated with IMN. In addition, immediate IMN for type IIIB and IIIC is potentially risky, and canal reaming did not increase the risk of complication for open tibial fractures treated with IMN.

The Internalized Homophobia Scale for Vietnamese Sexual Minority Women: Conceptualization, Factor Structure, Reliability, and Associations With Hypothesized Correlates.

PubMed

Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R

2016-08-01

We developed the first Vietnamese Internalized Homophobia (IH) scale for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n = 1187), or as bisexual (n = 641) and those who were unsure about their sexual identity (n = 353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscale associations with a wide range of hypothesized correlates, including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage, and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates, and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the minority stress model and the IH literature, and exhibited context-specific features, which are discussed.

The Internalized Homophobia Scale for Vietnamese Sexual Minority Women (IHVN-W): Conceptualization, factor structure, reliability, and associations with hypothesized correlates

PubMed Central

Nguyen, Trang Quynh; Poteat, Tonia; Bandeen-Roche, Karen; German, Danielle; Nguyen, Yen Hai; Vu, Loan Kieu-Chau; Nguyen, Nam Thi-Thu; Knowlton, Amy R.

2016-01-01

We developed the first Vietnamese internalized homophobia (IH) scale, for use with Vietnamese sexual minority women (SMW). Drawing from existing IH scales in the international literature and based on prior qualitative research about SMW in the Viet Nam context, the scale covers two domains: self-stigma (negative attitudes toward oneself as a sexual minority person) and sexual prejudice (negative attitudes toward homosexuality/same-sex relations in general). Scale items, including items borrowed from existing scales and items based on local expressions, were reviewed and confirmed by members of the target population. Quantitative evaluation used data from an anonymous web-based survey of Vietnamese SMW, including those who identified as lesbian (n=1187), or as bisexual (n=641) and those who were unsure about their sexual identity (n=353). The scale was found to consist of two highly correlated factors reflecting self-stigma (not normal/wholesome and self-reproach and wishing away same-sex sexuality) and one factor reflecting sexual prejudice, and to have excellent internal consistency. Construct validity was evidenced by subscales’ associations with a wide range of hypothesized correlates including perceived sexual stigma, outness, social support, connection to other SMW, relationship quality, psychological well-being, anticipation of heterosexual marriage and endorsement of same-sex marriage legalization. Self-stigma was more strongly associated with psychosocial correlates and sexual prejudice was more associated with endorsement of legal same-sex marriage. The variations in these associations across the hypothesized correlates and across sexual identity groups were consistent with the Minority Stress Model and the IH literature, and exhibited context-specific features, which are discussed. PMID:27007469

CORRELATION ANALYSIS BETWEEN TIBET AS-γ TeV COSMIC RAY AND WMAP NINE-YEAR DATA

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

Yin, Qian-Qing; Zhang, Shuang-Nan, E-mail: zhangsn@ihep.ac.cn

2015-08-01

The WMAP team subtracted template-based foreground models to produce foreground-reduced maps, and masked point sources and uncertain sky regions directly; however, whether foreground residuals exist in the WMAP foreground-reduced maps is still an open question. Here, we use Pearson correlation coefficient analysis with AS-γ TeV cosmic ray (CR) data to probe possible foreground residuals in the WMAP nine-year data. The correlation results between the CR and foreground-contained maps (WMAP foreground-unreduced maps, WMAP template-based, and Maximum Entropy Method foreground models) suggest that: (1) CRs can trace foregrounds in the WMAP data; (2) at least some TeV CRs originate from the Milkymore » Way; (3) foregrounds may be related to the existence of CR anisotropy (loss-cone and tail-in structures); (4) there exist differences among different types of foregrounds in the decl. range of <15°. Then, we generate 10,000 mock cosmic microwave background (CMB) sky maps to describe the cosmic variance, which is used to measure the effect of the fluctuations of all possible CMB maps to the correlations between CR and CMB maps. Finally, we do correlation analysis between the CR and WMAP foreground-reduced maps, and find that: (1) there are significant anticorrelations; and (2) the WMAP foreground-reduced maps are credible. However, the significant anticorrelations may be accidental, and the higher signal-to-noise ratio Planck SMICA map cannot reject the hypothesis of accidental correlations. We therefore can only conclude that the foreground residuals exist with ∼95% probability.« less

Critical thinking, self-esteem, and state anxiety of nursing students.

PubMed

Suliman, Wafika A; Halabi, Jehad

2007-02-01

This study aimed at exploring the existing predominant critical thinking disposition(s) of baccalaureate nursing students and the relationship among their critical thinking (CT), self-esteem (SE), and state anxiety (SA). Cross-sectional correlational design was utilized to achieve the said aim. A voluntary convenient sample consisted of first year (n=105) and fourth year (n=60) nursing students. The California Critical Thinking Disposition Inventory, Rosenberg Self-Esteem Scale, and Spielberger State Anxiety Inventory were used for data collection after their translation to Arabic language and test for validity and reliability. Descriptive and inferential statistics were used to analyze data. Results showed that both groups overall CT was marginal indicating no serious deficiency, their SE was average, and their SA was relatively high; they reported analyticity, open-mindedness, systematicity, inquisitiveness, and truth seeking as predominant critical thinking dispositions with no significant difference between them. However, the two groups were weak with significant difference on CT self-confidence (t=-2.053, df=136.904, p=.042) with beginning students reporting poorer level of CT self-confidence. Significant correlation results showed that critical thinking is positively correlated with SE, negatively correlated with SA, and SE is negatively correlated with SA; however, all correlations were actually quite low.

A high-significance measurement of correlation between unresolved IRAS sources and optically-selected galaxy clusters

NASA Astrophysics Data System (ADS)

Hincks, Adam D.; Hajian, Amir; Addison, Graeme E.

2013-05-01

We cross-correlate the 100 μm Improved Reprocessing of the IRAS Survey (IRIS) map and galaxy clusters at 0.1 < z < 0.3 in the maxBCG catalogue taken from the Sloan Digital Sky Survey, measuring an angular cross-power spectrum over multipole moments 150 < l < 3000 at a total significance of over 40σ. The cross-spectrum, which arises from the spatial correlation between unresolved dusty galaxies that make up the cosmic infrared background (CIB) in the IRIS map and the galaxy clusters, is well-fit by a single power law with an index of -1.28±0.12, similar to the clustering of unresolved galaxies from cross-correlating far-infrared and submillimetre maps at longer wavelengths. Using a recent, phenomenological model for the spectral and clustering properties of the IRIS galaxies, we constrain the large-scale bias of the maxBCG clusters to be 2.6±1.4, consistent with existing analyses of the real-space cluster correlation function. The success of our method suggests that future CIB-optical cross-correlations using Planck and Herschel data will significantly improve our understanding of the clustering and redshift distribution of the faint CIB sources.

Variety of Behavior of Equity Returns in Financial Markets

NASA Astrophysics Data System (ADS)

Bonanno, Giovanni; Lillo, Fabrizio; Mantegna, Rosario N.

2001-03-01

The price dynamics of a set of equities traded in an efficient market is pretty complex. It consists of almost not redundant time series which have (i) long-range correlated volatility and (ii) cross-correlation between each pair of equities. We perform a study of the statistical properties of an ensemble of equities returns which is fruitful to elucidate the nature and role of time and ensemble correlation. Specifically, we investigate a statistical ensemble of daily returns of n equities traded in United States financial markets. For each trading day of our database, we study the ensemble return distribution. We find that a typical ensemble return distribution exists in most of the trading days [1] with the exception of crash and rally days and of the days following to these extreme events [2]. We analyze each ensemble return distribution by extracting its first two central moments. We call the second moment of the ensemble return distribution the variety of the market. We choose this term because high variety implies a variated behavior of the equities returns in the considered day. We observe that the mean return and the variety are fluctuating in time and are stochastic processes themselves. The variety is a long-range correlated stochastic process. Customary time-averaged statistical properties of time series of stock returns are also considered. In general, time-averaged and portfolio-averaged returns have different statistical properties [1]. We infer from these differences information about the relative strength of correlation between equities and between different trading days. We also compare our empirical results with those predicted by the single-index model and we conclude that this simple model is unable to explain the statistical properties of the second moment of the ensemble return distribution. Correlation between pairs of equities are continuously present in the dynamics of a stock portfolio. Hence, it is relevant to investigate pair correlation in a efficient and original way. We propose to investigate these correlations at a daily and intra daily time horizon with a method based on concepts of random frustrated systems. Specifically, a hierarchical organization of the investigated equities is obtained by determining a metric distance between stocks and by investigating the properties of the subdominant ultrametric associated with it [3]. The high-frequency cross-correlation existing between pairs of equities are investigated in a set of 100 stocks traded in US equity markets. The decrease of the cross-correlation between the equity returns observed for diminishing time horizons progressively changes the nature of the hierarchical structure associated to each different time horizon [4]. The nature of the correlation present between pairs of time series of equity returns collected in a portfolio has a strong influence on the variety of the market. We finally discuss the relation between pair correlation and variety of an ensemble return distribution. References [1] Fabrizio Lillo and Rosario N. Mantegna, Variety and volatility in financial markets, Phys. Rev. E 62, 6126-6134 (2000). [2] Fabrizio Lillo and Rosario N. Mantegna, Symmetry alteration of ensemble return distribution in crash and rally days of financial market, Eur. Phys. J. B 15, 603-606 (2000). [3] Rosario N. Mantegna, Hierarchical structure in financial markets, Eur. Phys. J. B 11, 193-197 (1999). [4] Giovanni Bonanno, Fabrizio Lillo, and Rosario N. Mantegna, High-frequency cross-correlation in a set of stocks, Quantitative Finance (in press).

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

NASA Astrophysics Data System (ADS)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

Memory and long-range correlations in chess games

NASA Astrophysics Data System (ADS)

Schaigorodsky, Ana L.; Perotti, Juan I.; Billoni, Orlando V.

2014-01-01

In this paper we report the existence of long-range memory in the opening moves of a chronologically ordered set of chess games using an extensive chess database. We used two mapping rules to build discrete time series and analyzed them using two methods for detecting long-range correlations; rescaled range analysis and detrended fluctuation analysis. We found that long-range memory is related to the level of the players. When the database is filtered according to player levels we found differences in the persistence of the different subsets. For high level players, correlations are stronger at long time scales; whereas in intermediate and low level players they reach the maximum value at shorter time scales. This can be interpreted as a signature of the different strategies used by players with different levels of expertise. These results are robust against the assignation rules and the method employed in the analysis of the time series.

Psychopathology and weapon choice: a study of 103 perpetrators of homicide or attempted homicide.

PubMed

Catanesi, Roberto; Carabellese, Felice; Troccoli, Giuseppe; Candelli, Chiara; Grattagliano, Ignazio; Solarino, Biagio; Fortunato, Francesca

2011-06-15

The aim of this study was to ascertain if a relationship between weapon choice and psychopathology existed. The perpetrators (103) were evaluated at the Department of Criminology and Forensic Psychiatry of the University of Bari in southern Italy. Psychiatric examination and psycho-diagnostic tests were administered for each of the perpetrators and a database was subsequently formulated. The results showed a significant correlation between some types of mental disorder and weapon choice. A strong correlation was found between delusional disorders and the use of sharp weapons, whereas depressive disorders were more strongly associated with asphyxia. Organic disorders were found to be highly correlated with the use of blunt instruments. In cases where the homicide was the result of an impulsive reaction, the use of sharp weapons was most often observed. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Computing thermal Wigner densities with the phase integration method

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

Beutier, J.; Borgis, D.; Vuilleumier, R.

2014-08-28

We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta andmore » coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.« less

Monochromatic infrasonic tremor driven by persistent degassing and convection at Villarrica Volcano, Chile

NASA Astrophysics Data System (ADS)

Ripepe, M.; Marchetti, E.; Bonadonna, C.; Harris, A. J. L.; Pioli, L.; Ulivieri, G.

2010-08-01

Infrasonic data collected at Villarrica volcano (Chile) in March 2009 show a sustained, continuous, infrasonic oscillation (tremor) with a monochromatic low frequency content at ˜0.75 Hz. This tremor is extremely stable in time both at the summit and at a distal (˜4 km) small aperture array. Infrasonic tremor is characterized by discrete high amplitude bursts with a cyclic recurrence time of ˜40 s and is well correlated (0.93) with seismic tremor. These new data are compared with previous datasets collected in 2002 and 2004 during different levels of activity. All data show the same persistent infrasonic tremor and have the same strong correlation with seismic tremor. The stability and correlation of infrasonic and seismic tremor indicate the existence of a sustained and continuous process, which we suggest is related to the gravity-driven bubble column dynamics responsible for conduit convection.

Strong correlation between early stage atherosclerosis and electromechanical coupling of aorta

NASA Astrophysics Data System (ADS)

Liu, X. Y.; Yan, F.; Niu, L. L.; Chen, Q. N.; Zheng, H. R.; Li, J. Y.

2016-03-01

Atherosclerosis is the underlying cause of cardiovascular diseases that are responsible for many deaths in the world, and the early diagnosis of atherosclerosis is highly desirable. The existing imaging methods, however, are not capable of detecting the early stage of atherosclerosis development due to their limited spatial resolution. Using piezoresponse force microscopy (PFM), we show that the piezoelectric response of an aortic wall increases as atherosclerosis advances, while the stiffness of the aorta shows a less evident correlation with atherosclerosis. Furthermore, we show that there is strong correlation between the coercive electric field necessary to switch the polarity of the artery and the development of atherosclerosis. Thus by measuring the electromechanical coupling of the aortic wall, it is possible to probe atherosclerosis at the early stage of its development, not only improving the spatial resolution by orders of magnitude, but also providing comprehensive quantitative information on the biomechanical properties of the artery.

Computing thermal Wigner densities with the phase integration method.

PubMed

Beutier, J; Borgis, D; Vuilleumier, R; Bonella, S

2014-08-28

We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta and coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.

Local-feature analysis for automated coarse-graining of bulk-polymer molecular dynamics simulations.

PubMed

Xue, Y; Ludovice, P J; Grover, M A

2012-12-01

A method for automated coarse-graining of bulk polymers is presented, using the data-mining tool of local feature analysis. Most existing methods for polymer coarse-graining define superatoms based on their covalent bonding topology along the polymer backbone, but here superatoms are defined based only on their correlated motions, as observed in molecular dynamics simulations. Correlated atomic motions are identified in the simulation data using local feature analysis, between atoms in the same or in different polymer chains. Groups of highly correlated atoms constitute the superatoms in the coarse-graining scheme, and the positions of their seed coordinates are then projected forward in time. Based on only the seed positions, local feature analysis enables the full reconstruction of all atomic positions. This reconstruction suggests an iterative scheme to reduce the computation of the simulations to initialize another short molecular dynamic simulation, identify new superatoms, and again project forward in time.

Multidimensional Attosecond Resonant X-Ray Spectroscopy of Molecules: Lessons from the Optical Regime

PubMed Central

Mukamel, Shaul; Healion, Daniel; Zhang, Yu; Biggs, Jason D.

2013-01-01

New free-electron laser and high-harmonic generation X-ray light sources are capable of supplying pulses short and intense enough to perform resonant nonlinear time-resolved experiments in molecules. Valence-electron motions can be triggered impulsively by core excitations and monitored with high temporal and spatial resolution. We discuss possible experiments that employ attosecond X-ray pulses to probe the quantum coherence and correlations of valence electrons and holes, rather than the charge density alone, building on the analogy with existing studies of vibrational motions using femtosecond techniques in the visible regime. PMID:23245522

Self-calibrated correlation imaging with k-space variant correlation functions.

PubMed

Li, Yu; Edalati, Masoud; Du, Xingfu; Wang, Hui; Cao, Jie J

2018-03-01

Correlation imaging is a previously developed high-speed MRI framework that converts parallel imaging reconstruction into the estimate of correlation functions. The presented work aims to demonstrate this framework can provide a speed gain over parallel imaging by estimating k-space variant correlation functions. Because of Fourier encoding with gradients, outer k-space data contain higher spatial-frequency image components arising primarily from tissue boundaries. As a result of tissue-boundary sparsity in the human anatomy, neighboring k-space data correlation varies from the central to the outer k-space. By estimating k-space variant correlation functions with an iterative self-calibration method, correlation imaging can benefit from neighboring k-space data correlation associated with both coil sensitivity encoding and tissue-boundary sparsity, thereby providing a speed gain over parallel imaging that relies only on coil sensitivity encoding. This new approach is investigated in brain imaging and free-breathing neonatal cardiac imaging. Correlation imaging performs better than existing parallel imaging techniques in simulated brain imaging acceleration experiments. The higher speed enables real-time data acquisition for neonatal cardiac imaging in which physiological motion is fast and non-periodic. With k-space variant correlation functions, correlation imaging gives a higher speed than parallel imaging and offers the potential to image physiological motion in real-time. Magn Reson Med 79:1483-1494, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Role of short-range correlation in facilitation of wave propagation in a long-range ladder chain

NASA Astrophysics Data System (ADS)

Farzadian, O.; Niry, M. D.

2018-09-01

We extend a new method for generating a random chain, which has a kind of short-range correlation induced by a repeated sequence while retaining long-range correlation. Three distinct methods are considered to study the localization-delocalization transition of mechanical waves in one-dimensional disordered media with simultaneous existence of short and long-range correlation. First, a transfer-matrix method was used to calculate numerically the localization length of a wave in a binary chain. We found that the existence of short-range correlation in a long-range correlated chain can increase the localization length at the resonance frequency Ωc. Then, we carried out an analytical study of the delocalization properties of the waves in correlated disordered media around Ωc. Finally, we apply a dynamical method based on the direct numerical simulation of the wave equation to study the propagation of waves in the correlated chain. Imposing short-range correlation on the long-range background will lead the propagation to super-diffusive transport. The results obtained with all three methods are in agreement with each other.

Correlations Between Anthropometry and Lipid Profile in Women With PCOS.

PubMed

Kiranmayee, Donthu; Kavya, Kothapalli; Himabindu, Yalamanchali; Sriharibabu, Manne; Madhuri, Gadi Leela Jaya; Venu, Swargam

2017-01-01

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in reproductive age women and is associated with both reproductive and metabolic abnormalities. Recent studies have demonstrated an early onset of abnormal cardiovascular risk profile in women with PCOS. Abnormal lipid profile patterns are common in women with PCOS, and these abnormalities are not uniform in all populations. Anthropometry is a simple and commonly used research tool for assessing metabolic risk in women with PCOS. Therefore, this study examined the correlations between anthropometric parameters and lipid profile in women with PCOS. The objectives of the study were (1) To study the anthropometric profile of women with PCOS, (2) To examine the lipid profile pattern of these women with PCOS and (3) To see whether there exists any correlation between these anthropometric parameters and lipid profile. This observational cross-sectional study examined anthropometry and lipid profile in 86 married women with PCOS in the age group of 18-35 years and correlated them by using Pearson's correlation coefficient. More than 80% of the women with PCOS demonstrated abnormal anthropometric parameters, and in more than 70% women, lipid abnormalities such as low levels of high-density lipoprotein (HDL) cholesterol and high levels of triglycerides and low-density lipoprotein cholesterol were observed. Significant positive correlations were seen between body mass index (BMI) and triglycerides ( P ≤ 0.001) and waist circumference (WC) and triglycerides ( P ≤ 0.029). Negative correlations were observed between BMI and HDL cholesterol ( P ≤ 0.013). This study revealed that BMI and WC are the most important anthropometric parameters correlated to dyslipidemia in the south Indian women with PCOS.

Sciatic neurosteatosis: Relationship with age, gender, obesity and height.

PubMed

Ratner, Shayna; Khwaja, Raamis; Zhang, Lihua; Xi, Yin; Dessouky, Riham; Rubin, Craig; Chhabra, Avneesh

2018-04-01

To evaluate inter-reader performance for cross-sectional area and fat quantification of bilateral sciatic nerves on MRI and assess correlations with anthropometrics. In this IRB-approved, HIPPA-compliant study, three readers performed a cross-sectional analysis of 3T lumbosacral plexus MRIs over an 18-month period. Image slices were evaluated at two levels (A and B). The sciatic nerve was outlined using a free hand region of interest tool on PACS. Proton-density fat fraction (FF) and cross-sectional areas were recorded. Inter-reader agreement was assessed using intra-class correlation coefficient (ICC). Spearman correlation coefficients were used for correlations with age, BMI and height and Wilcoxon rank sum test was used to assess gender differences. A total of 67 patients were included in this study with male to female ratio of 1:1. Inter-reader agreement was good to excellent for FF measurements at both levels (ICC=0.71-0.90) and poor for sciatic nerve areas (ICC=0.08-0.27). Positive correlations of sciatic FF and area were seen with age (p value<0.05). Males had significantly higher sciatic intraneural fat than females (p<0.05). Fat quantification MRI is highly reproducible with significant positive correlations of sciatic FF and area with age, which may have implications for MRI diagnosis of sciatic neuropathy. • MR proton density fat fraction is highly reproducible at multiple levels. • Sciatic intraneural fat is positively correlated with increasing age (p < 0.05). • Positive correlations exist between bilateral sciatic nerve areas and age (p < 0.05). • Males had significantly higher sciatic intraneural fat than females (p < 0.05).

Does selection in a challenging environment produce Nile tilapia genotypes that can thrive in a range of production systems?

PubMed

Thoa, Ngo Phu; Ninh, Nguyen Huu; Knibb, Wayne; Nguyen, Nguyen Hong

2016-02-19

This study assessed whether selection for high growth in a challenging environment of medium salinity produces tilapia genotypes that perform well across different production environments. We estimated the genetic correlations between trait expressions in saline and freshwater using a strain of Nile tilapia selected for fast growth under salinity water of 15-20 ppt. We also estimated the heritability and genetic correlations for new traits of commercial importance (sexual maturity, feed conversion ratio, deformity and gill condition) in a full pedigree comprising 36,145 fish. The genetic correlations for the novel characters between the two environments were 0.78-0.99, suggesting that the effect of genotype by environment interaction was not biologically important. Across the environments, the heritability for body weight was moderate to high (0.32-0.62), indicating that this population will continue responding to future selection. The estimates of heritability for sexual maturity and survival were low but significant. The additive genetic components also exist for FCR, gill condition and deformity. Genetic correlations of harvest body weight with sexual maturity were positive and those between harvest body weight with FCR were negative. Our results indicate that the genetic line selected under a moderate saline water environment can be cultured successfully in freshwater systems.

Prediction of Geomagnetic Activity and Key Parameters in High-latitude Ionosphere

NASA Technical Reports Server (NTRS)

Khazanov, George V.; Lyatsky, Wladislaw; Tan, Arjun; Ridley, Aaron

2007-01-01

Prediction of geomagnetic activity and related events in the Earth's magnetosphere and ionosphere are important tasks of US Space Weather Program. Prediction reliability is dependent on the prediction method, and elements included in the prediction scheme. Two of the main elements of such prediction scheme are: an appropriate geomagnetic activity index, and an appropriate coupling function (the combination of solar wind parameters providing the best correlation between upstream solar wind data and geomagnetic activity). We have developed a new index of geomagnetic activity, the Polar Magnetic (PM) index and an improved version of solar wind coupling function. PM index is similar to the existing polar cap PC index but it shows much better correlation with upstream solar wind/IMF data and other events in the magnetosphere and ionosphere. We investigate the correlation of PM index with upstream solar wind/IMF data for 10 years (1995-2004) that include both low and high solar activity. We also have introduced a new prediction function for the predicting of cross-polar-cap voltage and Joule heating based on using both PM index and upstream solar wind/IMF data. As we show such prediction function significantly increase the reliability of prediction of these important parameters. The correlation coefficients between the actual and predicted values of these parameters are approx. 0.9 and higher.

Robust and sparse correlation matrix estimation for the analysis of high-dimensional genomics data.

PubMed

Serra, Angela; Coretto, Pietro; Fratello, Michele; Tagliaferri, Roberto; Stegle, Oliver

2018-02-15

Microarray technology can be used to study the expression of thousands of genes across a number of different experimental conditions, usually hundreds. The underlying principle is that genes sharing similar expression patterns, across different samples, can be part of the same co-expression system, or they may share the same biological functions. Groups of genes are usually identified based on cluster analysis. Clustering methods rely on the similarity matrix between genes. A common choice to measure similarity is to compute the sample correlation matrix. Dimensionality reduction is another popular data analysis task which is also based on covariance/correlation matrix estimates. Unfortunately, covariance/correlation matrix estimation suffers from the intrinsic noise present in high-dimensional data. Sources of noise are: sampling variations, presents of outlying sample units, and the fact that in most cases the number of units is much larger than the number of genes. In this paper, we propose a robust correlation matrix estimator that is regularized based on adaptive thresholding. The resulting method jointly tames the effects of the high-dimensionality, and data contamination. Computations are easy to implement and do not require hand tunings. Both simulated and real data are analyzed. A Monte Carlo experiment shows that the proposed method is capable of remarkable performances. Our correlation metric is more robust to outliers compared with the existing alternatives in two gene expression datasets. It is also shown how the regularization allows to automatically detect and filter spurious correlations. The same regularization is also extended to other less robust correlation measures. Finally, we apply the ARACNE algorithm on the SyNTreN gene expression data. Sensitivity and specificity of the reconstructed network is compared with the gold standard. We show that ARACNE performs better when it takes the proposed correlation matrix estimator as input. The R software is available at https://github.com/angy89/RobustSparseCorrelation. aserra@unisa.it or robtag@unisa.it. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Advanced Atherogenic Index for the Assessment of Consolidated Lipid Risk in Premature Coronary Artery Disease Patients in India.

PubMed

Bansal, Sanjiv Kumar; Agarwal, Sarita; Daga, Mridul Kumar

2016-01-01

The high prevalence, severity, and prematurity of coronary artery disease (CAD) in the Indian population cannot be completely explained by the conventional lipid parameters and the existing lipid indices. To calculate newly defined advanced atherogenic index (AAI) in premature CAD patients and compare it between cases and controls and Correlate its values with the existing indices. One hundred and twenty premature CAD patients and an equal number of age and sex matched healthy individuals were included in this study. Lipid profile and nonconventional lipid parameters like oxidized Low density lipoprotein (OX LDL), small dense LDL (SD LDL), lipoprotein (a) apolipoprotein B (Apo B), and apolipoprotein A1 (Apo A1) were estimated and their values were used to define AAI and existing lipid indices like AI, lipid tetrad index (LTI) and lipid pentad index (LPI). The mean age of cases and controls was 37.29 + 4.50 and 36.13 + 3.53 years, respectively. The value of AAI was highly significant in cases (3461.22 ± 45.20) as compared to controls (305.84 ± 21.80). AAI has shown better statistical significance and correlation (P < 0.0001, r = 0.737) as compared to the earlier indices such as AI (P < 0.01, r = 0.52), LTI (P < 0.001, r = 0.677) and LPI (P < 0.001, r = 0.622) in premature CAD. Kolmogorov D statistic and cumulative distribution function plot has shown that AAI can discriminate cases and controls more accurately as compared to the earlier indices. Statistically AAI appears to be a better marker of consolidated lipid risk in premature CAD patients as compared to the earlier indices.

Injury Source and Correlation Analysis of Riders in Car-Electric Bicycle Accidents

PubMed Central

Yi, Liang; Hu, Lin; Li, Yuelin

2018-01-01

The knowledge about the injury source and correlation of riders in car-electric bicycle accident will be helpful in the cross validation of traces and vehicle safety design. In order to know more information about such kind of knowledge, 57 true car-electric bicycle accidents were reconstructed by PC-Crash and then data on injury information of riders were collected directly from the reconstructed cases. These collected data were validated by some existing research results firstly, and then 4 abnormal cases were deleted according to the statistical method. Finally, conclusions can be obtained according to the data obtained from the remaining 53 cases. Direct injuries of the head and right leg are from the road pavement upon low speed; the source laws of indirect head injuries are not obvious. Upon intermediate and high speed, the injuries of the above parts are from automobiles. Injuries of the left leg, femur, and right knee are from automobiles; left knee injuries are from automobiles, the road pavement and automobiles, respectively, upon low, intermediate, and high speed. The source laws of indirect torso injuries are not obvious upon intermediate and low speed, which are from automobiles upon high speed, while direct torso injuries are from the road pavement. And there is no high correlation between all parts of the injury of riders. The largest correlation coefficient was the head-left femur and left femur-right femur, which was 0.647, followed by the head-right femur (0.638) and head-torso which was 0.617. PMID:29849757

Canopy near-infrared reflectance and terrestrial photosynthesis.

PubMed

Badgley, Grayson; Field, Christopher B; Berry, Joseph A

2017-03-01

Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIR V ). NIR V provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors. NIR V is strongly correlated with solar-induced chlorophyll fluorescence, a direct index of photons intercepted by chlorophyll, and with site-level and globally gridded estimates of GPP. NIR V makes it possible to use existing and future reflectance data as a starting point for accurately estimating GPP.

Canopy near-infrared reflectance and terrestrial photosynthesis

PubMed Central

Badgley, Grayson; Field, Christopher B.; Berry, Joseph A.

2017-01-01

Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIRV). NIRV provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors. NIRV is strongly correlated with solar-induced chlorophyll fluorescence, a direct index of photons intercepted by chlorophyll, and with site-level and globally gridded estimates of GPP. NIRV makes it possible to use existing and future reflectance data as a starting point for accurately estimating GPP. PMID:28345046

Linking environment-productivity trade-offs and correlated uncertainties: Greenhouse gas emissions and crop productivity in paddy rice production systems.

PubMed

Hayashi, Kiyotada; Nagumo, Yoshifumi; Domoto, Akiko

2016-11-15

In comparative life cycle assessments of agricultural production systems, analyses of both the trade-offs between environmental impacts and crop productivity and of the uncertainties specific to agriculture such as fluctuations in greenhouse gas (GHG) emissions and crop yields are crucial. However, these two issues are usually analyzed separately. In this paper, we present a framework to link trade-off and uncertainty analyses; correlated uncertainties are integrated into environment-productivity trade-off analyses. We compared three rice production systems in Japan: a system using a pelletized, nitrogen-concentrated organic fertilizer made from poultry manure using closed-air composting techniques (high-N system), a system using a conventional organic fertilizer made from poultry manure using open-air composting techniques (low-N system), and a system using a chemical compound fertilizer (conventional system). We focused on two important sources of uncertainties in paddy rice cultivation-methane emissions from paddy fields and crop yields. We found trade-offs between the conventional and high-N systems and the low-N system and the existence of positively correlated uncertainties in the conventional and high-N systems. We concluded that our framework is effective in recommending the high-N system compared with the low-N system, although the performance of the former is almost the same as the conventional system. Copyright © 2016 Elsevier B.V. All rights reserved.

Strongly correlated perovskite fuel cells

NASA Astrophysics Data System (ADS)

Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D.; Ramanathan, Shriram

2016-06-01

Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

Strongly correlated perovskite fuel cells

DOE PAGES

Zhou, You; Guan, Xiaofei; Zhou, Hua; ...

2016-05-16

Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes.more » Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.« less

Strongly correlated perovskite fuel cells.

PubMed

Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D; Ramanathan, Shriram

2016-06-09

Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

Association between somatotypes and blood pressure in an adult Chuvasha population.

PubMed

Kalichman, Leonid; Livshits, Gregory; Kobyliansky, Eugene

2004-01-01

The relationship between blood pressure (BP) and anthropometrical characteristics has been indeed examined extensively, but only a few studies have investigated any connection of somatotypes to BP. to evaluate the association between BP and various anthropometrical characteristics, including components of somatotypes (using the methods of Heath and Carter and of Deriabin). The study sample comprised 783 males aged 18-89 years and 720 females aged 18-90 years, all residents of the Chuvasha, Russian Federation. We used multiple regression, Pearson's and canonical correlation analyses. Significant correlations (r = 0.19-0.28, p < 0.05) were obtained between BP and anthropometric characteristics associated with body compositions and somatotypes. The most impressive were the canonical correlations between BP and somatotype components derived according to Heath and Carter (0.275), and according to Deriabin's (0.333) method. Different body types were highly significantly (P < 0.001) associated with systolic and diastolic BP. Individuals of robust physique (with high endomorphy and mesomorphy) showed high mean values of systolic and diastolic BP, whereas the smallest persons had the lowest BP values. These findings suggest the existence of common physiological paths in the development of body physique and blood pressure regulation and may possibly be indicative of the involvement of pleiotropic genetic and/or epigenetic mechanisms in this regulation.

Expansion and retention of pulmonary CD4+ T cells after prime boost vaccination correlates with improved longevity and strength of immunity against tularemia.

PubMed

Roberts, Lydia M; Wehrly, Tara D; Crane, Deborah D; Bosio, Catharine M

2017-05-02

Francisella tularensis subsp. tularensis strain SchuS4 (Ftt) is a highly virulent intracellular bacterium. Inhalation of 10 or fewer organisms results in an acute and potentially lethal disease called pneumonic tularemia. Ftt infections occur naturally in the U.S. and Ftt was developed as a bioweapon. Thus, there is a need for vaccines that protect against this deadly pathogen. Although a live vaccine strain of Francisella tularensis (LVS) exists, LVS fails to generate long-lived protective immunity against modest challenge doses of Ftt. We recently identified an important role for high avidity CD4 + T cells in short-term protection and hypothesized that expanding this pool of cells would improve overall vaccine efficacy with regard to longevity and challenge dose. In support of our hypothesis, application of a prime/boost vaccination strategy increased the pool of high avidity CD4 + T cells which correlated with improved survival following challenge with either increased doses of virulent Ftt or at late time points after vaccination. In summary, we demonstrate that both epitope selection and vaccination strategies that expand antigen-specific T cells correlate with superior immunity to Ftt as measured by survival. Copyright © 2017. Published by Elsevier Ltd.

Neutron star radii, universal relations, and the role of prior distributions

DOE PAGES

Steiner, Andrew W.; Lattimer, James M.; Brown, Edward F.

2016-02-02

We investigate constraints on neutron star structure arising from the assumptions that neutron stars have crusts, that recent calculations of pure neutron matter limit the equation of state of neutron star matter near the nuclear saturation density, that the high-density equation of state is limited by causality and the largest high-accuracy neutron star mass measurement, and that general relativity is the correct theory of gravity. We explore the role of prior assumptions by considering two classes of equation of state models. In a first, the intermediate- and high-density behavior of the equation of state is parameterized by piecewise polytropes. Inmore » the second class, the high-density behavior of the equation of state is parameterized by piecewise continuous line segments. The smallest density at which high-density matter appears is varied in order to allow for strong phase transitions above the nuclear saturation density. We critically examine correlations among the pressure of matter, radii, maximum masses, the binding energy, the moment of inertia, and the tidal deformability, paying special attention to the sensitivity of these correlations to prior assumptions about the equation of state. It is possible to constrain the radii of 1.4 solar mass neutron stars to be larger than 10 km, even without consideration of additional astrophysical observations, for example, those from photospheric radius expansion bursts or quiescent low-mass X-ray binaries. We are able to improve the accuracy of known correlations between the moment of inertia and compactness as well as the binding energy and compactness. Furthermore, we also demonstrate the existence of a correlation between the neutron star binding energy and the moment of inertia.« less

Angio-Architectural Features of High-Grade Intracranial Dural Arteriovenous Fistulas: Correlation With Aggressive Clinical Presentation and Hemorrhagic Risk.

PubMed

Della Pepa, Giuseppe Maria; Parente, Paolo; D'Argento, Francesco; Pedicelli, Alessandro; Sturiale, Carmelo Lucio; Sabatino, Giovanni; Albanese, Alessio; Puca, Alfredo; Fernandez, Eduardo; Olivi, Alessando; Marchese, Enrico

2017-08-01

High-grade dural arteriovenous fistulas (dAVFs) can present shunts with very different angio-architectural characteristics. Specific hemodynamic factors may affect clinical history and determine very different clinical courses. To evaluate the relationship between some venous angio-architectural features in high-grade dAVFs and clinical presentation. Specific indicators of moderate or severe venous hypertension were analyzed, such as altered configurations of the dural sinuses (by a single or a dual thrombosis), or overload of cortical vessels (restrictions of outflow, pseudophlebitic cortical vessels, and venous aneurysms). The institutional series was retrospectively reviewed (49 cases), and the pattern of venous drainage was analyzed in relationship with clinical presentation (benign/aggressive/hemorrhage). Thirty-five of 49 cases displayed cortical reflux (high-grade dAVFs). This subgroup displayed a benign presentation in 31.42% of cases, an aggressive in 31.42%, and hemorrhage in 37.14%. Our data confirm that within high-grade dAVFs, 2 distinct subpopulations exist according to severity of clinical presentation. Some indicators we examined showed correlation with aggressive nonhemorrhagic manifestations (outflow restriction and pseudophlebitic cortical vessels), while other showed a correlation with hemorrhage (dual thrombosis and venous aneurysms). Current classifications appear insufficient to identify a wide range of conditions that ultimately determine the organization of the cortical venous drainage. Intermediate degrees of venous congestion correlate better with the clinical risk than the simple definition of cortical reflux. The angiographic aspects of venous drainage presented in this study may prove useful to assess dAVF hemodynamic characteristics and identify conditions at higher clinical risk. Copyright © 2017 by the Congress of Neurological Surgeons

Positive Correlation between Serum Osteocalcin and Testosterone in Male Hyperthyroidism Patients with High Bone Turnover.

PubMed

Zhong, N; Xu, B; Cui, R; Xu, M; Su, J; Zhang, Z; Liu, Y; Li, L; Sheng, C; Sheng, H; Qu, S

2016-07-01

Animal studies suggested that there is an independent bone-osteocalcin-gonadal axis, except of the hypothalamic-pituitary-gonadal axis. Based on this hypothesis, the higher osteocalcin during the high bone turnover should be followed by higher testosterone formation. Yet such clinical evidence is limited. The patients with uncontrolled hyperthyroidism are proper model with high bone turnover. If this hypothesis is true, there should be high testosterone level in patients with uncontrolled hyperthyroidism. Therefore, Graves' disease patients were recruited to study the correlation between osteocalcin and testosterone. 50 male hyperthyroidism patients with Graves' disease and 50 health persons matched by age and gender were enrolled in our cross-section study. Serum markers for thyroid hormone, sex hormone and bone metabolic markers including free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and osteocalcin (OC), C-terminal telopeptide fragments of type I collagen (CTX) were examined. The demographic parameters such as duration of disease were also collected. All data was analyzed by SPSS 20.0. High testosterone and osteocalcin level was observed in the hyperthyroidism patients (T 36.35±10.72 nmol/l and OC 46.79±26.83 ng/ml). In simple Pearson correlation, testosterone was positively associated with OC (r=0.486, P<0.001), and this positive relation still existed after adjusted for age, BMI, smoking, drinking, duration of disease, FT3, FT4, LH, FSH, CTX in multi-linear regression analysis (See Model 1-4). In male hyperthyroidism patients, osteocalcin was positively correlated with serum testosterone, which indirectly supports the hypothesis that serum osteocalcin participates in the regulation of sex hormone. © Georg Thieme Verlag KG Stuttgart · New York.

Can metamorphosis survival during larval development in spiny lobster Sagmariasus verreauxi be improved through quantitative genetic inheritance?

PubMed

Nguyen, Nguyen H; Fitzgibbon, Quinn P; Quinn, Jane; Smith, Greg; Battaglene, Stephen; Knibb, Wayne

2018-05-04

One of the major impediments to spiny lobster aquaculture is the high cost of hatchery production due to the long and complex larval cycle and poor survival during the many moult stages, especially at metamorphosis. We examined if the key trait of larval survival can be improved through selection by determining if genetic variance exists for this trait. Specifically, we report, for the first time, genetic parameters (heritability and correlations) for early survival rates recorded at five larval phases; early-phyllosoma stages (instars 1-6; S1), mid-phyllosoma stages (instars; 7-12; S2), late-phyllosoma stages (instars 13-17; S3), metamorphosis (S4) and puerulus stage (S5) in hatchery-reared spiny lobster Sagmariasus verreauxi. The data were collected from a total of 235,060 larvae produced from 18 sires and 30 dams over nine years (2006 to 2014). Parentage of the offspring and full-sib families was verified using ten microsatellite markers. Analysis of variance components showed that the estimates of heritability for all the five phases of larval survival obtained from linear mixed model were generally similar to those obtained from threshold logistic generalised models (0.03-0.47 vs. 0.01-0.50). The heritability estimates for survival traits recorded in the early larval phases (S1 and S2) were higher than those estimated in later phases (S3, S4 and S5). The existence of the additive genetic component in larval survival traits indicate that they could be improved through selection. Both phenotypic and genetic correlations among the five survival measures studied were moderate to high and positive. The genetic associations between successive rearing periods were stronger than those that are further apart. Our estimates of heritability and genetic correlations reported here in a spiny lobster species indicate that improvement in the early survival especially during metamorphosis can be achieved through genetic selection in this highly economic value species.

An effective and efficient compression algorithm for ECG signals with irregular periods.

PubMed

Chou, Hsiao-Hsuan; Chen, Ying-Jui; Shiau, Yu-Chien; Kuo, Te-Son

2006-06-01

This paper presents an effective and efficient preprocessing algorithm for two-dimensional (2-D) electrocardiogram (ECG) compression to better compress irregular ECG signals by exploiting their inter- and intra-beat correlations. To better reveal the correlation structure, we first convert the ECG signal into a proper 2-D representation, or image. This involves a few steps including QRS detection and alignment, period sorting, and length equalization. The resulting 2-D ECG representation is then ready to be compressed by an appropriate image compression algorithm. We choose the state-of-the-art JPEG2000 for its high efficiency and flexibility. In this way, the proposed algorithm is shown to outperform some existing arts in the literature by simultaneously achieving high compression ratio (CR), low percent root mean squared difference (PRD), low maximum error (MaxErr), and low standard derivation of errors (StdErr). In particular, because the proposed period sorting method rearranges the detected heartbeats into a smoother image that is easier to compress, this algorithm is insensitive to irregular ECG periods. Thus either the irregular ECG signals or the QRS false-detection cases can be better compressed. This is a significant improvement over existing 2-D ECG compression methods. Moreover, this algorithm is not tied exclusively to JPEG2000. It can also be combined with other 2-D preprocessing methods or appropriate codecs to enhance the compression performance in irregular ECG cases.

PageRank as a method to rank biomedical literature by importance.

PubMed

Yates, Elliot J; Dixon, Louise C

2015-01-01

Optimal ranking of literature importance is vital in overcoming article overload. Existing ranking methods are typically based on raw citation counts, giving a sum of 'inbound' links with no consideration of citation importance. PageRank, an algorithm originally developed for ranking webpages at the search engine, Google, could potentially be adapted to bibliometrics to quantify the relative importance weightings of a citation network. This article seeks to validate such an approach on the freely available, PubMed Central open access subset (PMC-OAS) of biomedical literature. On-demand cloud computing infrastructure was used to extract a citation network from over 600,000 full-text PMC-OAS articles. PageRanks and citation counts were calculated for each node in this network. PageRank is highly correlated with citation count (R = 0.905, P < 0.01) and we thus validate the former as a surrogate of literature importance. Furthermore, the algorithm can be run in trivial time on cheap, commodity cluster hardware, lowering the barrier of entry for resource-limited open access organisations. PageRank can be trivially computed on commodity cluster hardware and is linearly correlated with citation count. Given its putative benefits in quantifying relative importance, we suggest it may enrich the citation network, thereby overcoming the existing inadequacy of citation counts alone. We thus suggest PageRank as a feasible supplement to, or replacement of, existing bibliometric ranking methods.

Continuous, Large-Scale Processing of Seismic Archives for High-Resolution Monitoring of Seismic Activity and Seismogenic Properties

NASA Astrophysics Data System (ADS)

Waldhauser, F.; Schaff, D. P.

2012-12-01

Archives of digital seismic data recorded by seismometer networks around the world have grown tremendously over the last several decades helped by the deployment of seismic stations and their continued operation within the framework of monitoring earthquake activity and verification of the Nuclear Test-Ban Treaty. We show results from our continuing effort in developing efficient waveform cross-correlation and double-difference analysis methods for the large-scale processing of regional and global seismic archives to improve existing earthquake parameter estimates, detect seismic events with magnitudes below current detection thresholds, and improve real-time monitoring procedures. We demonstrate the performance of these algorithms as applied to the 28-year long seismic archive of the Northern California Seismic Network. The tools enable the computation of periodic updates of a high-resolution earthquake catalog of currently over 500,000 earthquakes using simultaneous double-difference inversions, achieving up to three orders of magnitude resolution improvement over existing hypocenter locations. This catalog, together with associated metadata, form the underlying relational database for a real-time double-difference scheme, DDRT, which rapidly computes high-precision correlation times and hypocenter locations of new events with respect to the background archive (http://ddrt.ldeo.columbia.edu). The DDRT system facilitates near-real-time seismicity analysis, including the ability to search at an unprecedented resolution for spatio-temporal changes in seismogenic properties. In areas with continuously recording stations, we show that a detector built around a scaled cross-correlation function can lower the detection threshold by one magnitude unit compared to the STA/LTA based detector employed at the network. This leads to increased event density, which in turn pushes the resolution capability of our location algorithms. On a global scale, we are currently building the computational framework for double-difference processing the combined parametric and waveform archives of the ISC, NEIC, and IRIS with over three million recorded earthquakes worldwide. Since our methods are scalable and run on inexpensive Beowulf clusters, periodic re-analysis of such archives may thus become a routine procedure to continuously improve resolution in existing global earthquake catalogs. Results from subduction zones and aftershock sequences of recent great earthquakes demonstrate the considerable social and economic impact that high-resolution images of active faults, when available in real-time, will have in the prompt evaluation and mitigation of seismic hazards. These results also highlight the need for consistent long-term seismic monitoring and archiving of records.

Scaling Exponents in Financial Markets

NASA Astrophysics Data System (ADS)

Kim, Kyungsik; Kim, Cheol-Hyun; Kim, Soo Yong

2007-03-01

We study the dynamical behavior of four exchange rates in foreign exchange markets. A detrended fluctuation analysis (DFA) is applied to detect the long-range correlation embedded in the non-stationary time series. It is for our case found that there exists a persistent long-range correlation in volatilities, which implies the deviation from the efficient market hypothesis. Particularly, the crossover is shown to exist in the scaling behaviors of the volatilities.

A toy model to investigate the existence of excitons in the ground state of strongly-correlated semiconductor

NASA Astrophysics Data System (ADS)

Karima, H. R.; Majidi, M. A.

2018-04-01

Excitons, quasiparticles associated with bound states between an electron and a hole and are typically created when photons with a suitable energy are absorbed in a solid-state material. We propose to study a possible emergence of excitons, created not by photon absorption but the effect of strong electronic correlations. This study is motivated by a recent experimental study of a substrate material SrTiO3 (STO) that reveals strong exitonic signals in its optical conductivity. Here we conjecture that some excitons may already exist in the ground state as a result of the electronic correlations before the additional excitons being created later by photon absorption. To investigate the existence of excitons in the ground state, we propose to study a simple 4-energy-level model that mimics a situation in strongly-correlated semiconductors. The four levels are divided into two groups, lower and upper groups separated by an energy gap, Eg , mimicking the valence and the conduction bands, respectively. Further, we incorporate repulsive Coulomb interactions between the electrons. The model is then solved by exact diagonalization method. Our result shows that the toy model can demonstrate band gap widening or narrowing and the existence of exciton in the ground state depending on interaction parameter values.

Existing branches correlatively inhibit further branching in Trifolium repens: possible mechanisms

PubMed Central

Thomas, R. G.; Hay, M. J. M.

2011-01-01

In Trifolium repens removal of any number of existing branches distal to a nodal root stimulates development of axillary buds further along the stem such that the complement of branches distal to a nodal root remains constant. This study aimed to assess possible mechanisms by which existing branches correlatively inhibit the outgrowth of axillary buds distal to them. Treatments were applied to basal branches to evaluate the roles of three postulated inhibitory mechanisms: (I) the transport of a phloem-mobile inhibitory feedback signal from branches into the main stem; (II) the polar flow of auxin from branches into the main stem acting to limit further branch development; or (III) the basal branches functioning as sinks for a net root-derived stimulatory signal (NRS). Results showed that transport of auxin, or of a non-auxin phloem-mobile signal, from basal branches did not influence regulation of correlative inhibition and were consistent with the possibility that the intra-plant distribution of NRS could be involved in the correlative inhibition of distal buds by basal branches. This study supports existing evidence that regulation of branching in T. repens is dominated by a root-derived stimulatory signal, initially distributed via the xylem, the characterization of which will progress the generic understanding of branching regulation. PMID:21071681

Association of Neck Circumference and Obesity with Blood Pressure among Adolescents in Urban and Rural Population in North Tamil Nadu.

PubMed

Rajagopalan, Archana; Balaji, Nisha

2017-01-01

Since a few studies exist on the association of neck circumference (NC) and obesity with blood pressure (BP) among adolescents in India, we found it highly relevant to measure the NC and body mass index (BMI) using them as indicators of upper body subcutaneous fat and obesity and relate them to BP in a rural and urban adolescent population in North Tamil Nadu. This is a community-based cross-sectional study of descriptive design where 500 students from urban and rural areas were selected, and their BMI, NC, and BP were measured using standardized instruments. Among urban and rural population high and normal NC positively correlated with BMI, systolic BP (SBP) and diastolic BP (DBP), indicating that the data clearly reflects increase in BMI, SBP, and DBP values with increase in NC or vice versa. The correlation was statistically significant ( P < 0.001) significantly higher BMI ( P < 0.01), SBP ( P < 0.05), and NC ( P < 0.001) was observed in urban population than rural. DBP was not significantly different in rural and urban population. 95 th percentile values are significantly higher than rest in both urban and rural population. Only the 95 th percentile values correlate and reflect similar changes in BMI, SBP, and DBP. Our studies indicate a strong association of elevation in BP with high NC and increase in BMI. Overweight and obesity were positively correlated with increase in SBP and DBP.

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

PubMed

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

2016-03-01

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

Inverse correlation between quasiparticle mass and Tc in a cuprate high-Tc superconductor

PubMed Central

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

2016-01-01

Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature Tc is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-Tc superconductivity. We have tested the robustness of this correlation between m* and Tc by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as Tc increases under pressure. This inverse correlation between m* and Tc suggests that quantum fluctuations of the charge order enhance m* but do not enhance Tc. PMID:27034989

Negative correlation learning for customer churn prediction: a comparison study.

PubMed

Rodan, Ali; Fayyoumi, Ayham; Faris, Hossam; Alsakran, Jamal; Al-Kadi, Omar

2015-01-01

Recently, telecommunication companies have been paying more attention toward the problem of identification of customer churn behavior. In business, it is well known for service providers that attracting new customers is much more expensive than retaining existing ones. Therefore, adopting accurate models that are able to predict customer churn can effectively help in customer retention campaigns and maximizing the profit. In this paper we will utilize an ensemble of Multilayer perceptrons (MLP) whose training is obtained using negative correlation learning (NCL) for predicting customer churn in a telecommunication company. Experiments results confirm that NCL based MLP ensemble can achieve better generalization performance (high churn rate) compared with ensemble of MLP without NCL (flat ensemble) and other common data mining techniques used for churn analysis.

Quantification of Fibrosis and Osteosclerosis in Myeloproliferative Neoplasms: A Computer-Assisted Image Study

PubMed Central

Teman, Carolin J.; Wilson, Andrew R.; Perkins, Sherrie L.; Hickman, Kimberly; Prchal, Josef T.; Salama, Mohamed E.

2010-01-01

Evaluation of bone marrow fibrosis and osteosclerosis in myeloproliferative neoplasms (MPN) is subject to interobserver inconsistency. Performance data for currently utilized fibrosis grading systems are lacking, and classification scales for osteosclerosis do not exist. Digital imaging can serve as a quantification method for fibrosis and osteosclerosis. We used digital imaging techniques for trabecular area assessment and reticulin-fiber quantification. Patients with all Philadelphia negative MPN subtypes had higher trabecular volume than controls (p ≤0.0015). Results suggest that the degree of osteosclerosis helps differentiate primary myelofibrosis from other MPN. Numerical quantification of fibrosis highly correlated with subjective scores, and interobserver correlation was satisfactory. Digital imaging provides accurate quantification for osteosclerosis and fibrosis. PMID:20122729

The correlation structure of several popular pseudorandom number generators

NASA Technical Reports Server (NTRS)

Neuman, F.; Merrick, R.; Martin, C. F.

1973-01-01

One of the desirable properties of a pseudorandom number generator is that the sequence of numbers it generates should have very low autocorrelation for all shifts except for zero shift and those that are multiples of its cycle length. Due to the simple methods of constructing random numbers, the ideal is often not quite fulfilled. A simple method of examining any random generator for previously unsuspected regularities is discussed. Once they are discovered it is often easy to derive the mathematical relationships, which describe the mathematical relationships, which describe the regular behavior. As examples, it is shown that high correlation exists in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle lengths.

Study of TEC and foF2 with the Help of GPS and Ionosonde Data over Maitri, Antarctica

NASA Astrophysics Data System (ADS)

Khatarkar, Prakash; Gwal, Ashok Kumar

Prakash Khatarkar, Purusottam Bhaware, Azad Ahmad Mansoori, Varsha Kachneria, Shweta Thakur, and A. K. Gwal Abstract The behavior of ionosphere can be diagnosed by a number of techniques. The common techniques used are the space based Global Positioning System and the ground based Ionosonde. We have compared the variability of ionospheric parameters by using two different techniques GPS and Ionosonde, during December 2009 to November 2010 at the Indian base station Maitri (11.45E, 70.45S). The comparison between the measurements of two techniques was realized through the Total Electron Content (TEC) parameters derived by using different methods. The comparison was made diurnally, seasonally, polar day and polar night variations and the annually. From our analysis we found that a strong correlation exists between the GPS derived TEC and Ionosonde derived foF2 during the day period while during the night time the correlation is insignificant. At the same time we found that a strong correlation exists between the Ionosonde and GPS derived TEC. The pattern of variation of ionospheric parameters derived from two techniques is strikingly similar indicating that the high degree of synchronization between them. This has a practical applicability by allowing calculating the error in one technique by comparing with other. Keywords: Ionosphere, Ionosonde, GPS, foF2, TEC.

Correlation between standard plate count and somatic cell count milk quality results for Wisconsin dairy producers.

PubMed

Borneman, Darand L; Ingham, Steve

2014-05-01

The objective of this study was to determine if a correlation exists between standard plate count (SPC) and somatic cell count (SCC) monthly reported results for Wisconsin dairy producers. Such a correlation may indicate that Wisconsin producers effectively controlling sanitation and milk temperature (reflected in low SPC) also have implemented good herd health management practices (reflected in low SCC). The SPC and SCC results for all grade A and B dairy producers who submitted results to the Wisconsin Department of Agriculture, Trade, and Consumer Protection, in each month of 2012 were analyzed. Grade A producer SPC results were less dispersed than grade B producer SPC results. Regression analysis showed a highly significant correlation between SPC and SCC, but the R(2) value was very small (0.02-0.03), suggesting that many other factors, besides SCC, influence SPC. Average SCC (across 12 mo) for grade A and B producers decreased with an increase in the number of monthly SPC results (out of 12) that were ≤ 25,000 cfu/mL. A chi-squared test of independence showed that the proportion of monthly SCC results >250,000 cells/mL varied significantly depending on whether the corresponding SPC result was ≤ 25,000 or >25,000 cfu/mL. This significant difference occurred in all months of 2012 for grade A and B producers. The results suggest that a generally consistent level of skill exists across dairy production practices affecting SPC and SCC. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Improved identification of the solution space of aerosol microphysical properties derived from the inversion of profiles of lidar optical data, part 1: theory.

PubMed

Kolgotin, Alexei; Müller, Detlef; Chemyakin, Eduard; Romanov, Anton

2016-12-01

Multiwavelength Raman/high spectral resolution lidars that measure backscatter coefficients at 355, 532, and 1064 nm and extinction coefficients at 355 and 532 nm can be used for the retrieval of particle microphysical parameters, such as effective and mean radius, number, surface-area and volume concentrations, and complex refractive index, from inversion algorithms. In this study, we carry out a correlation analysis in order to investigate the degree of dependence that may exist between the optical data taken with lidar and the underlying microphysical parameters. We also investigate if the correlation properties identified in our study can be used as a priori or a posteriori constraints for our inversion scheme so that the inversion results can be improved. We made the simplifying assumption of error-free optical data in order to find out what correlations exist in the best case situation. Clearly, for practical applications, erroneous data need to be considered too. On the basis of simulations with synthetic optical data, we find the following results, which hold true for arbitrary particle size distributions, i.e., regardless of the modality or the shape of the size distribution function: surface-area concentrations and extinction coefficients are linearly correlated with a correlation coefficient above 0.99. We also find a correlation coefficient above 0.99 for the extinction coefficient versus (1) the ratio of the volume concentration to effective radius and (2) the product of the number concentration times the sum of the squares of the mean radius and standard deviation of the investigated particle size distributions. Besides that, we find that for particles of any mode fraction of the particle size distribution, the complex refractive index is uniquely defined by extinction- and backscatter-related Ångström exponents, lidar ratios at two wavelengths, and an effective radius.

A comparison of confidence interval methods for the intraclass correlation coefficient in community-based cluster randomization trials with a binary outcome.

PubMed

Braschel, Melissa C; Svec, Ivana; Darlington, Gerarda A; Donner, Allan

2016-04-01

Many investigators rely on previously published point estimates of the intraclass correlation coefficient rather than on their associated confidence intervals to determine the required size of a newly planned cluster randomized trial. Although confidence interval methods for the intraclass correlation coefficient that can be applied to community-based trials have been developed for a continuous outcome variable, fewer methods exist for a binary outcome variable. The aim of this study is to evaluate confidence interval methods for the intraclass correlation coefficient applied to binary outcomes in community intervention trials enrolling a small number of large clusters. Existing methods for confidence interval construction are examined and compared to a new ad hoc approach based on dividing clusters into a large number of smaller sub-clusters and subsequently applying existing methods to the resulting data. Monte Carlo simulation is used to assess the width and coverage of confidence intervals for the intraclass correlation coefficient based on Smith's large sample approximation of the standard error of the one-way analysis of variance estimator, an inverted modified Wald test for the Fleiss-Cuzick estimator, and intervals constructed using a bootstrap-t applied to a variance-stabilizing transformation of the intraclass correlation coefficient estimate. In addition, a new approach is applied in which clusters are randomly divided into a large number of smaller sub-clusters with the same methods applied to these data (with the exception of the bootstrap-t interval, which assumes large cluster sizes). These methods are also applied to a cluster randomized trial on adolescent tobacco use for illustration. When applied to a binary outcome variable in a small number of large clusters, existing confidence interval methods for the intraclass correlation coefficient provide poor coverage. However, confidence intervals constructed using the new approach combined with Smith's method provide nominal or close to nominal coverage when the intraclass correlation coefficient is small (<0.05), as is the case in most community intervention trials. This study concludes that when a binary outcome variable is measured in a small number of large clusters, confidence intervals for the intraclass correlation coefficient may be constructed by dividing existing clusters into sub-clusters (e.g. groups of 5) and using Smith's method. The resulting confidence intervals provide nominal or close to nominal coverage across a wide range of parameters when the intraclass correlation coefficient is small (<0.05). Application of this method should provide investigators with a better understanding of the uncertainty associated with a point estimator of the intraclass correlation coefficient used for determining the sample size needed for a newly designed community-based trial. © The Author(s) 2015.

Genotype by environment interaction for activity-based estrus traits in relation to production level for Danish Holstein.

PubMed

Ismael, Ahmed; Strandberg, Erling; Berglund, Britt; Kargo, Morten; Fogh, Anders; Løvendahl, Peter

2016-12-01

The objective of this study was to investigate whether genotype by environment interaction exists for female fertility traits and production of energy-corrected milk at 70d in milk (ECM70). Fertility traits considered were the activity-based estrus traits interval from calving to first high activity (CFHA), duration of high activity episode (DHA), as an indicator for first estrus duration, and strength of high activity episode (SHA), as an indicator for first estrus strength. The physical activity traits were derived from electronic activity tags for 11,522 first-parity cows housed in 125 commercial dairy herds. Data were analyzed using a univariate random regression animal model (URRM), by regressing the phenotypic performance on the average herd ECM70 as an environmental gradient. Furthermore, the genetic correlations between CFHA and ECM70 as a function of production level were estimated using a bivariate random regression animal model (BRRM). For all traits, heterogeneity of additive genetic variances and heritability estimates was observed. The heritability estimate for CFHA decreased from 0.25 to 0.10 with increasing production level and the heritability estimate for ECM70 decreased from 0.35 to 0.15 with increasing production level using URRM. The genetic correlation of the same trait in low and high production levels was around 0.74 for CFHA and 0.80 for ECM70 using URRM, but when data were analyzed using the multiple-trait analysis (MT), genetic correlation estimates between low and high production levels were not significantly different from unity. Furthermore, the genetic correlation of SHA between low and high production level was 0.22 using URRM, but the corresponding correlation estimate had large standard error when data were analyzed using MT. The genetic correlation between CFHA and ECM70 as a function of production environment was weak but unfavorable and decreased slightly from 0.09 to 0.04 with increasing production level using BRRM. Moreover, the same trend was observed when the data were analyzed using MT where the genetic correlation between CFHA and ECM70 in the low production environment was 0.29 compared with -0.13 in the high production environment, but these estimates had large standard errors. In conclusion, regardless of the trait used, in relation to average herd ECM70 production, the results indicated no clear evidence of strong genotype by environment interaction that would cause significant re-ranking of sires between low and high production environments. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Improving Localization Accuracy: Successive Measurements Error Modeling

PubMed Central

Abu Ali, Najah; Abu-Elkheir, Mervat

2015-01-01

Vehicle self-localization is an essential requirement for many of the safety applications envisioned for vehicular networks. The mathematical models used in current vehicular localization schemes focus on modeling the localization error itself, and overlook the potential correlation between successive localization measurement errors. In this paper, we first investigate the existence of correlation between successive positioning measurements, and then incorporate this correlation into the modeling positioning error. We use the Yule Walker equations to determine the degree of correlation between a vehicle’s future position and its past positions, and then propose a p-order Gauss–Markov model to predict the future position of a vehicle from its past p positions. We investigate the existence of correlation for two datasets representing the mobility traces of two vehicles over a period of time. We prove the existence of correlation between successive measurements in the two datasets, and show that the time correlation between measurements can have a value up to four minutes. Through simulations, we validate the robustness of our model and show that it is possible to use the first-order Gauss–Markov model, which has the least complexity, and still maintain an accurate estimation of a vehicle’s future location over time using only its current position. Our model can assist in providing better modeling of positioning errors and can be used as a prediction tool to improve the performance of classical localization algorithms such as the Kalman filter. PMID:26140345

The structural, connectomic and network covariance of the human brain.

PubMed

Irimia, Andrei; Van Horn, John D

2013-02-01

Though it is widely appreciated that complex structural, functional and morphological relationships exist between distinct areas of the human cerebral cortex, the extent to which such relationships coincide remains insufficiently appreciated. Here we determine the extent to which correlations between brain regions are modulated by either structural, connectomic or network-theoretic properties using a structural neuroimaging data set of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) volumes acquired from N=110 healthy human adults. To identify the linear relationships between all available pairs of regions, we use canonical correlation analysis to test whether a statistically significant correlation exists between each pair of cortical parcels as quantified via structural, connectomic or network-theoretic measures. In addition to this, we investigate (1) how each group of canonical variables (whether structural, connectomic or network-theoretic) contributes to the overall correlation and, additionally, (2) whether each individual variable makes a significant contribution to the test of the omnibus null hypothesis according to which no correlation between regions exists across subjects. We find that, although region-to-region correlations are extensively modulated by structural and connectomic measures, there are appreciable differences in how these two groups of measures drive inter-regional correlation patterns. Additionally, our results indicate that the network-theoretic properties of the cortex are strong modulators of region-to-region covariance. Our findings are useful for understanding the structural and connectomic relationship between various parts of the brain, and can inform theoretical and computational models of cortical information processing. Published by Elsevier Inc.

Reveal quantum correlation in complementary bases

PubMed Central

Wu, Shengjun; Ma, Zhihao; Chen, Zhihua; Yu, Sixia

2014-01-01

An essential feature of genuine quantum correlation is the simultaneous existence of correlation in complementary bases. We reveal this feature of quantum correlation by defining measures based on invariance under a basis change. For a bipartite quantum state, the classical correlation is the maximal correlation present in a certain optimum basis, while the quantum correlation is characterized as a series of residual correlations in the mutually unbiased bases. Compared with other approaches to quantify quantum correlation, our approach gives information-theoretical measures that directly reflect the essential feature of quantum correlation. PMID:24503595

Brain abnormalities in high-risk violent offenders and their association with psychopathic traits and criminal recidivism.

PubMed

Leutgeb, V; Leitner, M; Wabnegger, A; Klug, D; Scharmüller, W; Zussner, T; Schienle, A

2015-11-12

Measures of psychopathy have been proved to be valuable for risk assessment in violent criminals. However, the neuronal basis of psychopathy and its contribution to the prediction of criminal recidivism is still poorly understood. We compared structural imaging data from 40 male high-risk violent offenders and 37 non-delinquent healthy controls via voxel-based morphometry. Psychopathic traits and risk of violence recidivism were correlated with gray matter volume (GMV) of regions of interest previously shown relevant for criminal behavior. Relative to controls, criminals showed less GMV in the prefrontal cortex (PFC) and more GMV in cerebellar regions and basal ganglia structures. Within criminals, we found a negative correlation between prefrontal GMV and psychopathy. Additionally, there was a positive correlation between cerebellar GMV and psychopathy as well as risk of recidivism for violence. Moreover, GMVs of the basal ganglia and supplementary motor area (SMA) were positively correlated with anti-sociality. GMV of the amygdala was negatively correlated with dynamic risk for violence recidivism. In contrast, GMV of (para)limbic areas (orbitofrontal cortex, insula) was positively correlated with anti-sociality and risk of violence recidivism. The current investigation revealed that in violent offenders deviations in GMV of the PFC as well as areas involved in the motor component of impulse control (cerebellum, basal ganglia, SMA) are differentially related to psychopathic traits and the risk of violence recidivism. The results might be valuable for improving existing risk assessment tools. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Development of reliable predictive heat transfer correlations for low-rank coal-fired fluid bed combustors. Final report

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

Grewal, N.S.

(1) The proposed correlation of Equation (5) is recommended to predict the maximum value of heat transfer coefficient between a horzontal tube and a gas-solid fluidized bed of small particles under the conditions given. For high temperature applications (T/sub B/ > 600/sup 0/C), the radiative component is important and was estimated following Baskakov et al. (2) The proposed correlation of Equation (8) was found reliable to predict the existing data on the maximum value of heat transfer coefficient between a horizontal tube bundle and a gas-solid fluidized bed of small particles under the conditions given. At high temperatures, the radiativemore » component was estimated from the experimental data of Baskakov et al. (3) The correlation of Equation (8) predicted the GFETC data taken during the combustion of low-rank coal very well, when the contribution due to radiation was estimated following Baskakov et al. (4) The correlations proposed by Grewal and Bansal et al. were found to predict the data taken during low-rank coal combustion within +-25%, when the contribution due to radiation was included and estimated following Baskakov et al. (5) Finally, the correlations for large particles (anti d/sub p/ > 1mm) as proposed by Glicksman and Decker, Catipovic et al., Xavier and Davidson, and Zabrodsky et al. also predicted the data for low-rank coal fluidized bed combustor quite well, when the radiative component was estimated from the data of Baskakov et al. 64 references, 19 figures, 10 tables.« less

Global Terrestrial Water Storage Changes and Connections to ENSO Events

NASA Astrophysics Data System (ADS)

Ni, Shengnan; Chen, Jianli; Wilson, Clark R.; Li, Jin; Hu, Xiaogong; Fu, Rong

2018-01-01

Improved data quality of extended record of the Gravity Recovery and Climate Experiment (GRACE) satellite gravity solutions enables better understanding of terrestrial water storage (TWS) variations. Connections of TWS and climate change are critical to investigate regional and global water cycles. In this study, we provide a comprehensive analysis of global connections between interannual TWS changes and El Niño Southern Oscillation (ENSO) events, using multiple sources of data, including GRACE measurements, land surface model (LSM) predictions and precipitation observations. We use cross-correlation and coherence spectrum analysis to examine global connections between interannual TWS changes and the Niño 3.4 index, and select four river basins (Amazon, Orinoco, Colorado, and Lena) for more detailed analysis. The results indicate that interannual TWS changes are strongly correlated with ENSO over much of the globe, with maximum cross-correlation coefficients up to 0.70, well above the 95% significance level ( 0.29) derived by the Monte Carlo experiments. The strongest correlations are found in tropical and subtropical regions, especially in the Amazon, Orinoco, and La Plata basins. While both GRACE and LSM TWS estimates show reasonably good correlations with ENSO and generally consistent spatial correlation patterns, notably higher correlations are found between GRACE TWS and ENSO. The existence of significant correlations in middle-high latitudes shows the large-scale impact of ENSO on the global water cycle.

Metformin Accumulation Correlates with Organic Cation Transporter 2 Protein Expression and Predicts Mammary Tumor Regression in Vivo

PubMed Central

Checkley, L. Allyson; Rudolph, Michael C.; Wellberg, Elizabeth A.; Giles, Erin D.; Wahdan-Alaswad, Reema S.; Houck, Julie A.; Edgerton, Susan M.; Thor, Ann D.; Schedin, Pepper; Anderson, Steven M.; MacLean, Paul S.

2017-01-01

Several epidemiological studies have associated metformin treatment with a reduction in breast cancer incidence in pre-diabetic and type II diabetic populations. Uncertainty exists regarding which patient populations and/or tumor subtypes will benefit from metformin treatment, and most preclinical in vivo studies have given little attention to the cellular pharmacology of intratumoral metformin uptake. Epidemiological reports consistently link western-style high fat diets, which drive overweight and obesity, with increased risk of breast cancer. We used a rat model of high fat diet (HFD) induced overweight and mammary carcinogenesis to define intratumoral factors that confer metformin sensitivity. Mammary tumors were initiated with N-methyl-N-nitrosourea (MNU), and rats were randomized into metformin-treated (2 mg/ml drinking water) or control groups (water only) for 8 weeks. Two-thirds of existing mammary tumors responded to metformin treatment with decreased tumor volumes (p<0.05), reduced proliferative index (p<0.01), and activated AMPK (p<0.05). Highly responsive tumors accumulated 3-fold greater metformin amounts (p<0.05) that were positively correlated with organic cation transporter-2 (OCT2) protein expression (r=0.57, P=0.038). Importantly, intratumoral metformin concentration negatively associated with tumor volume (P=0.03), and each 10 pmol increase in intratumoral metformin predicted >0.11 cm3 reduction in tumor volume. Metformin treatment also decreased proinflammatory arachidonic acid >1.5 fold in responsive tumors (P=0.023). Collectively, these preclinical data provide evidence for a direct effect of metformin in vivo and suggest that OCT2 expression may predict metformin uptake and tumor response. PMID:28154203

Dynamic statistical optimization of GNSS radio occultation bending angles: advanced algorithm and performance analysis

NASA Astrophysics Data System (ADS)

Li, Y.; Kirchengast, G.; Scherllin-Pirscher, B.; Norman, R.; Yuan, Y. B.; Fritzer, J.; Schwaerz, M.; Zhang, K.

2015-08-01

We introduce a new dynamic statistical optimization algorithm to initialize ionosphere-corrected bending angles of Global Navigation Satellite System (GNSS)-based radio occultation (RO) measurements. The new algorithm estimates background and observation error covariance matrices with geographically varying uncertainty profiles and realistic global-mean correlation matrices. The error covariance matrices estimated by the new approach are more accurate and realistic than in simplified existing approaches and can therefore be used in statistical optimization to provide optimal bending angle profiles for high-altitude initialization of the subsequent Abel transform retrieval of refractivity. The new algorithm is evaluated against the existing Wegener Center Occultation Processing System version 5.6 (OPSv5.6) algorithm, using simulated data on two test days from January and July 2008 and real observed CHAllenging Minisatellite Payload (CHAMP) and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) measurements from the complete months of January and July 2008. The following is achieved for the new method's performance compared to OPSv5.6: (1) significant reduction of random errors (standard deviations) of optimized bending angles down to about half of their size or more; (2) reduction of the systematic differences in optimized bending angles for simulated MetOp data; (3) improved retrieval of refractivity and temperature profiles; and (4) realistically estimated global-mean correlation matrices and realistic uncertainty fields for the background and observations. Overall the results indicate high suitability for employing the new dynamic approach in the processing of long-term RO data into a reference climate record, leading to well-characterized and high-quality atmospheric profiles over the entire stratosphere.

Higher-Order Factors of Personality: Do They Exist?

PubMed Central

Ashton, Michael C.; Lee, Kibeom; Goldberg, Lewis R.; de Vries, Reinout E.

2010-01-01

Scales that measure the Big Five personality factors are often substantially intercorrelated. These correlations are sometimes interpreted as implying the existence of two higher-order factors of personality. We show that correlations between measures of broad personality factors do not necessarily imply the existence of higher-order factors, and might instead be due to variables that represent same-signed blends of orthogonal factors. Therefore, the hypotheses of higher-order factors and blended variables can only be tested with data on lower-level personality variables that define the personality factors. We compared the higher-order factor model and the blended variable model in three participant samples using the Big Five Aspect Scales, and found better fit for the latter model. In other analyses using the HEXACO Personality Inventory, we identified mutually uncorrelated markers of six personality factors. We conclude that correlations between personality factor scales can be explained without postulating any higher-order dimensions of personality. PMID:19458345

Solar wind structure suggested by bimodal correlations of solar wind speed and density between the spacecraft SOHO and Wind

NASA Astrophysics Data System (ADS)

Ogilvie, K. W.; Coplan, M. A.; Roberts, D. A.; Ipavich, F.

2007-08-01

We calculate the cross-spacecraft maximum lagged-cross-correlation coefficients for 2-hour intervals of solar wind speed and density measurements made by the plasma instruments on the Solar and Heliospheric Observatory (SOHO) and Wind spacecraft over the period from 1996, the minimum of solar cycle 23, through the end of 2005. During this period, SOHO was located at L1, about 200 R E upstream from the Earth, while Wind spent most of the time in the interplanetary medium at distances of more than 100 R E from the Earth. Yearly histograms of the maximum, time-lagged correlation coefficients for both the speed and density are bimodal in shape, suggesting the existence of two distinct solar wind regimes. The larger correlation coefficients we suggest are due to structured solar wind, including discontinuities and shocks, while the smaller are likely due to Alfvénic turbulence. While further work will be required to firmly establish the physical nature of the two populations, the results of the analysis are consistent with a solar wind that consists of turbulence from quiet regions of the Sun interspersed with highly filamentary structures largely convected from regions in the inner solar corona. The bimodal appearance of the distributions is less evident in the solar wind speed than in the density correlations, consistent with the observation that the filamentary structures are convected with nearly constant speed by the time they reach 1 AU. We also find that at solar minimum the fits for the density correlations have smaller high-correlation components than at solar maximum. We interpret this as due to the presence of more relatively uniform Alfvénic regions at solar minimum than at solar maximum.

Decorrelation of L-band and C-band interferometry to volcanic risk prevention

NASA Astrophysics Data System (ADS)

Malinverni, E. S.; Sandwell, D.; Tassetti, A. N.; Cappelletti, L.

2013-10-01

SAR has several strong key features: fine spatial resolution/precision and high temporal pass frequency. Moreover, the InSAR technique allows the accurate detection of ground deformations. This high potential technology can be invaluable to study volcanoes: it provides important information on pre-eruption surface deformation, improving the understanding of volcanic processes and the ability to predict eruptions. As a downside, SAR measurements are influenced by artifacts such as atmospheric effects or bad topographic data. Correlation gives a measure of these interferences, quantifying the similarity of the phase of two SAR images. Different approaches exists to reduce these errors but the main concern remain the possibility to correlate images with different acquisition times: snow-covered or heavily-vegetated areas produce seasonal changes on the surface. Minimizing the time between passes partly limits decorrelation. Though, images with a short temporal baseline aren't always available and some artifacts affecting correlation are timeindependent. This work studies correlation of pairs of SAR images focusing on the influence of surface and climate conditions, especially snow coverage and temperature. Furthermore, the effects of the acquisition band on correlation are taken into account, comparing L-band and C-band images. All the chosen images cover most of the Yellowstone caldera (USA) over a span of 4 years, sampling all the seasons. Interferograms and correlation maps are generated. To isolate temporal decorrelation, pairs of images with the shortest baseline are chosen. Correlation maps are analyzed in relation to snow depth and temperature. Results obtained with ENVISAT and ERS satellites (C-band) are compared with the ones from ALOS (L-band). Results show a good performance during winter and a bad attitude towards wet snow (spring and fall). During summer both L-band and C-band maintain a good coherence with L-band performing better over vegetation.

Correlated Encounter Model for Cooperative Aircraft in the National Airspace System; Version 2.0

DTIC Science & Technology

2018-05-08

Lincoln Laboratory MASSACHUSETTS INSTITUTE OF TECHNOLOGY LEXINGTON, MASSACHUSETTS Project Report ATC-440 Correlated Encounter Model for...specifically authorized by the U.S. Government may violate any copyrights that exist in this work. Correlated Encounter Model for Cooperative Aircraft...2008 Correlated Encounter Model for Cooperative Aircraft (CEM) subsequently referred to as the Extended Correlated Encounter Model (ECEM). This model

Predicting radiocaesium sorption characteristics with soil chemical properties for Japanese soils.

PubMed

Uematsu, Shinichiro; Smolders, Erik; Sweeck, Lieve; Wannijn, Jean; Van Hees, May; Vandenhove, Hildegarde

2015-08-15

The high variability of the soil-to-plant transfer factor of radiocaesium (RCs) compels a detailed analysis of the radiocaesium interception potential (RIP) of soil, which is one of the specific factors ruling the RCs transfer. The range of the RIP values for agricultural soils in the Fukushima accident affected area has not yet been fully surveyed. Here, the RIP and other major soil chemical properties were characterised for 51 representative topsoils collected in the vicinity of the Fukushima contaminated area. The RIP ranged a factor of 50 among the soils and RIP values were lower for Andosols compared to other soils, suggesting a role of soil mineralogy. Correlation analysis revealed that the RIP was most strongly and negatively correlated to soil organic matter content and oxalate extractable aluminium. The RIP correlated weakly but positively to soil clay content. The slope of the correlation between RIP and clay content showed that the RIP per unit clay was only 4.8 mmol g(-1) clay, about threefold lower than that for clays of European soils, suggesting more amorphous minerals and less micaceous minerals in the clay fraction of Japanese soils. The negative correlation between RIP and soil organic matter may indicate that organic matter can mask highly selective sorption sites to RCs. Multiple regression analysis with soil organic matter and cation exchange capacity explained the soil RIP (R(2)=0.64), allowing us to map soil RIP based on existing soil map information. Copyright © 2015 Elsevier B.V. All rights reserved.

Cross-cultural adaptation and validation of the Korean version of the neck disability index.

PubMed

Song, Kyung-Jin; Choi, Byung-Wan; Choi, Byung-Ryeul; Seo, Gyeu-Beom

2010-09-15

Validation of a translated, culturally adapted questionnaire. The purpose of this study is to translate and culturally adapt the Neck Disability Index (NDI) and to validate the use of the derived version in Korean patient. Although several valid measures exist for measurement of neck pain and functional impairment, these measures have yet been validated in Korean version. The NDI was linguistically translated into Korean, and prefinal version was assessed and modified by a pilot study. The reliability and validity of the derived Korean version was examined in 78 patients with degenerative cervical spine disease. Test-retest reliability, internal consistency, and construct validity were investigated by comparing Visual Analogue Scale (VAS) and Short Form Health Survey (SF-36) scores. Factor analysis of Korean NDI extracted 2 factors with eigenvalues >1. The intraclass-correlation coefficient of test-retest reliability was 0.93. Reliability, estimated by internal consistency, had a Cronbach alpha value of 0.82. The correlation between NDI and VAS scores was r = 0.49, and the correlation between NDI and SF-36 scores was r = -0.44. The physical health component score of SF-36 was highly correlated with NDI, and the correlation between VAS scores and the mental health component scores of SF-36 was high. The derived Korean version of the NDI was found to be a reliable and valid instrument for measuring disability in Korean patients with cervical problems. The authors recommend its use in future Korean clinical studies.

Classifying and Standardizing Panfacial Trauma With a New Bony Facial Trauma Score.

PubMed

Casale, Garrett G A; Fishero, Brian A; Park, Stephen S; Sochor, Mark; Heltzel, Sara B; Christophel, J Jared

2017-01-01

The practice of facial trauma surgery would benefit from a useful quantitative scale that measures the extent of injury. To develop a facial trauma scale that incorporates only reducible fractures and is able to be reliably communicated to health care professionals. A cadaveric tissue study was conducted from October 1 to 3, 2014. Ten cadaveric heads were subjected to various degrees of facial trauma by dropping a fixed mass onto each head. The heads were then imaged with fine-cut computed tomography. A Bony Facial Trauma Scale (BFTS) for grading facial trauma was developed based only on clinically relevant (reducible) fractures. The traumatized cadaveric heads were then scored using this scale as well as 3 existing scoring systems. Regression analysis was used to determine correlation between degree of incursion of the fixed mass on the cadaveric heads and trauma severity as rated by the scoring systems. Statistical analysis was performed to determine correlation of the scores obtained using the BFTS with those of the 3 existing scoring systems. Scores obtained using the BFTS were not correlated with dentition (95% CI, -0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (95% CI, -0.068 to 0.944; P = .08). Facial trauma scores. Among all 10 cadaveric specimens (9 male donors and 1 female donor; age range, 41-87 years; mean age, 57.2 years), the facial trauma scores obtained using the BFTS correlated with depth of penetration of the mass into the face (odds ratio, 4.071; 95% CI, 1.676-6.448) P = .007) when controlling for presence of dentition and age. The BFTS scores also correlated with scores obtained using 3 existing facial trauma models (Facial Fracture Severity Scale, rs = 0.920; Craniofacial Disruption Score, rs = 0.945; and ZS Score, rs = 0.902; P < .001 for all 3 models). In addition, the BFTS was found to have excellent interrater reliability (0.908; P = .001), which was similar to the interrater reliability of the other 3 tested trauma scales. Scores obtained using the BFTS were not correlated with dentition (odds ratio, .482; 95% CI, -0.087 to 1.053; P = .08; measured as absolute number of teeth) or age of the cadaveric donor (odds ratio, .436; 95% CI, -0.068 to 0.944; P = .08). Facial trauma severity as measured by the BFTS correlated with depth of penetration of the fixed mass into the face. In this study, the BFTS was clinically relevant, had high fidelity in communicating the fractures sustained in facial trauma, and correlated well with previously validated models. NA.

Analysis of the acute response of Galleria mellonella larvae to potassium nitrate.

PubMed

Maguire, Ronan; Kunc, Martin; Hyrsl, Pavel; Kavanagh, Kevin

2017-05-01

Potassium nitrate (E252) is widely used as a food preservative and has applications in the treatment of high blood pressure however high doses are carcinogenic. Larvae of Galleria mellonella were administered potassium nitrate to establish whether the acute effects in larvae correlated with those evident in mammals. Intra-haemocoel injection of potassium nitrate resulted in a significant increase in the density of circulating haemocytes and a small change in the relative proportions of haemocytes but haemocytes showed a reduced fungicidal ability. Potassium nitrate administration resulted in increased superoxide dismutase activity and in the abundance of a range of proteins associated with mitochondrial function (e.g. mitochondrial aldehyde dehydrogenase, putative mitochondrial Mn superoxide dismutase), metabolism (e.g. triosephosphate isomerase, glyceraldehyde 3 phosphate dehydrogenase) and nitrate metabolism (e.g. aliphatic nitrilase, glutathione S-transferase). A strong correlation exists between the toxicity of a range of food preservatives when tested in G. mellonella larvae and rats. In this work a correlation between the effect of potassium nitrate in larvae and mammals is shown and opens the way to the utilization of insects for studying the in vivo acute and chronic toxicity of xenobiotics. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation of understanding of physics and psychological symptoms among high-school students in Greece

NASA Astrophysics Data System (ADS)

Aggeliki, Anagnostopoulou; Miltiades, Kyprianou; Antigoni-Elisavet, Rota; Evangelia, Pavlatou; Loizos, Zaphiris

2017-09-01

Depression may essentially influence cognitive function contributing to poor school performance. The present study undertakes to determine the existence and strength of correlation between depressive symptomatology and other mental conditions with the acquired level of understanding of Newtonian physics taught in schools. The current study recruited 490 students (262 girls, 228 boys) attending the first semester of the Greek Second Grade of General Lyceum School. Force Concept Inventory (FCI) tested the depth of the students’ understanding of Newtonian Physics. Symptom Checklist-90-R assessed general mental status. The tests took place in the classroom during a 1 h session. Low FCI scores significantly correlated with mental conditions, with depression ranking first. Girls had higher scores in all nine symptoms scales of SCL-90 and lower FCI scores. Stepwise regression models proved that the gender effect on FCI could be effectively explained through the significant effect of depression. An understanding of Newtonian physics among high school students may be restricted by common problematic mental conditions, with depression being the greatest among all. Further research, using a more systematic approach to measure depression among adolescents with poor understanding of physics, would help to elucidate the nature of the effect.

Relevance of graph literacy in the development of patient-centered communication tools.

PubMed

Nayak, Jasmir G; Hartzler, Andrea L; Macleod, Liam C; Izard, Jason P; Dalkin, Bruce M; Gore, John L

2016-03-01

To determine the literacy skill sets of patients in the context of graphical interpretation of interactive dashboards. We assessed literacy characteristics of prostate cancer patients and assessed comprehension of quality of life dashboards. Health literacy, numeracy and graph literacy were assessed with validated tools. We divided patients into low vs. high numeracy and graph literacy. We report descriptive statistics on literacy, dashboard comprehension, and relationships between groups. We used correlation and multiple linear regressions to examine factors associated with dashboard comprehension. Despite high health literacy in educated patients (78% college educated), there was variation in numeracy and graph literacy. Numeracy and graph literacy scores were correlated (r=0.37). In those with low literacy, graph literacy scores most strongly correlated with dashboard comprehension (r=0.59-0.90). On multivariate analysis, graph literacy was independently associated with dashboard comprehension, adjusting for age, education, and numeracy level. Even among higher educated patients; variation in the ability to comprehend graphs exists. Clinicians must be aware of these differential proficiencies when counseling patients. Tools for patient-centered communication that employ visual displays need to account for literacy capabilities to ensure that patients can effectively engage these resources. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A Comparative Study of Acousto-Optic Time-Integrating Correlators for Adaptive Jamming Cancellation

DTIC Science & Technology

1997-10-01

This final report presents a comparative study of the space-integrating and time-integrating configurations of an acousto - optic correlator...systematically evaluate all existing acousto - optic correlator architectures and to determine which would be most suitable for adaptive jamming

Multi-particle correlations in transverse momenta from statistical clusters

NASA Astrophysics Data System (ADS)

Bialas, Andrzej; Bzdak, Adam

2016-09-01

We evaluate n-particle (n = 2 , 3 , 4 , 5) transverse momentum correlations for pions and kaons following from the decay of statistical clusters. These correlation functions could provide strong constraints on a possible existence of thermal clusters in the process of particle production.

Second feature of the matter two-point function

NASA Astrophysics Data System (ADS)

Tansella, Vittorio

2018-05-01

We point out the existence of a second feature in the matter two-point function, besides the acoustic peak, due to the baryon-baryon correlation in the early Universe and positioned at twice the distance of the peak. We discuss how the existence of this feature is implied by the well-known heuristic argument that explains the baryon bump in the correlation function. A standard χ2 analysis to estimate the detection significance of the second feature is mimicked. We conclude that, for realistic values of the baryon density, a SKA-like galaxy survey will not be able to detect this feature with standard correlation function analysis.

On the relationship between positive and negative affect: Their correlation and their co-occurrence.

PubMed

Larsen, Jeff T; Hershfield, Hal E; Stastny, Bradley J; Hester, Neil

2017-03-01

Understanding the nature of emotional experience requires understanding the relationship between positive and negative affect. Two particularly important aspects of that relationship are the extent to which positive and negative affect are correlated with one another and the extent to which they co-occur. Some researchers have assumed that weak negative correlations imply greater co-occurrence (i.e., more mixed emotions) than do strong negative correlations, but others have noted that correlations may imply very little about co-occurrence. We investigated the relationship between the correlation between positive and negative affect and co-occurrence. Participants in each of 2 samples provided moment-to-moment happiness and sadness ratings as they watched an evocative film and listened to music. Results indicated (a) that 4 measures of the correlation between positive and negative affect were quite highly related to 1 another; (b) that the strength of the correlation between measures of mixed emotions varied considerably; (c) that correlational measures were generally (but not always) weakly correlated with mixed emotion measures; and (d) that bittersweet stimuli consistently led to elevations in mixed emotion measures but did not consistently weaken the correlation between positive and negative affect. Results highlight that the correlation between positive and negative affect and their co-occurrence are distinct aspects of the relationship between positive and negative affect. Such insight helps clarify the implications of existing work on age-related and cultural differences in emotional experience and sets the stage for greater understanding of the experience of mixed emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Towards timelike singularity via AdS dual

NASA Astrophysics Data System (ADS)

Bhowmick, Samrat; Chatterjee, Soumyabrata

2017-07-01

It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore, one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various extremal surfaces including spacelike geodesics in the dual gravity description. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.

Effect of the microscopic correlated-pinning landscape on the macroscopic critical current density in YBCO films

NASA Astrophysics Data System (ADS)

Ghigo, G.; Chiodoni, A.; Gerbaldo, R.; Gozzelino, L.; Laviano, F.; Mezzetti, E.; Minetti, B.; Camerlingo, C.

This paper deals with the mechanisms controlling the critical current density vs. field behavior in YBCO films. We base our analysis on a suitable model concerning the existence of a network of intergrain Josephson junctions whose length is modulated by defects. Irradiation with 0.25 GeV Au ions provide a useful tool to check the texture of the sample, in particular to give a gauge length reference to separate “weak” links and high- J c links.

Nonlinear aerodynamic wing design

NASA Technical Reports Server (NTRS)

Bonner, Ellwood

1985-01-01

The applicability of new nonlinear theoretical techniques is demonstrated for supersonic wing design. The new technology was utilized to define outboard panels for an existing advanced tactical fighter model. Mach 1.6 maneuver point design and multi-operating point compromise surfaces were developed and tested. High aerodynamic efficiency was achieved at the design conditions. A corollary result was that only modest supersonic penalties were incurred to meet multiple aerodynamic requirements. The nonlinear potential analysis of a practical configuration arrangement correlated well with experimental data.

From Mild to WildLV14378 Fluctuations in Crystal Plasticity

NASA Astrophysics Data System (ADS)

Weiss, J.; Rhouma, W. Ben; Richeton, T.; Dechanel, S.; Louchet, F.; Truskinovsky, L.

2015-03-01

Macroscopic crystal plasticity is classically viewed as an outcome of uncorrelated dislocation motions producing Gaussian fluctuations. An apparently conflicting picture emerged in recent years emphasizing highly correlated dislocation dynamics characterized by power-law distributed fluctuations. We use acoustic emission measurements in crystals with different symmetries to show that intermittent and continuous visions of plastic flow are not incompatible. We demonstrate the existence of crossover regimes where strongly intermittent events coexist with a Gaussian quasiequilibrium background and propose a simple theoretical framework compatible with these observations.

Method of determining forest production from remotely sensed forest parameters

DOEpatents

Corey, J.C.; Mackey, H.E. Jr.

1987-08-31

A method of determining forest production entirely from remotely sensed data in which remotely sensed multispectral scanner (MSS) data on forest 5 composition is combined with remotely sensed radar imaging data on forest stand biophysical parameters to provide a measure of forest production. A high correlation has been found to exist between the remotely sensed radar imaging data and on site measurements of biophysical 10 parameters such as stand height, diameter at breast height, total tree height, mean area per tree, and timber stand volume.

The effects of cocaine on HIV transcription.

PubMed

Tyagi, Mudit; Weber, Jaime; Bukrinsky, Michael; Simon, Gary L

2016-06-01

Illicit drug users are a high-risk population for infection with the human immunodeficiency virus (HIV). A strong correlation exists between prohibited drug use and an increased rate of HIV transmission. Cocaine stands out as one of the most frequently abused illicit drugs, and its use is correlated with HIV infection and disease progression. The central nervous system (CNS) is a common target for both drugs of abuse and HIV, and cocaine intake further accelerates neuronal injury in HIV patients. Although the high incidence of HIV infection in illicit drug abusers is primarily due to high-risk activities such as needle sharing and unprotected sex, several studies have demonstrated that cocaine enhances the rate of HIV gene expression and replication by activating various signal transduction pathways and downstream transcription factors. In order to generate mature HIV genomic transcript, HIV gene expression has to pass through both the initiation and elongation phases of transcription, which requires discrete transcription factors. In this review, we will provide a detailed analysis of the molecular mechanisms that regulate HIV transcription and discuss how cocaine modulates those mechanisms to upregulate HIV transcription and eventually HIV replication.

Effect of atomizer scale and fluid properties on atomization mechanisms and spray characteristics

NASA Astrophysics Data System (ADS)

Waind, Travis

Atomization is chaos. The breakup of liquid structures by a gas encompasses such a wide range of possible configurations that a definitive mechanism describing breakup in any and all situations is an impossibility. However, when focus is applied, trends can be teased out of experimental data that seem to appropriately describe the action undertaken. These studies sought to better understand atomization, specifically coaxial, two-stream, airblast (or air-assist) atomization in which a central liquid jet is broken up by an annular, high-velocity gas stream. The studies enclosed focused on identifying the effect of changing the atomizer's scale on atomization. While most (but not all) atomization studies only focus on the resulting far-field drop diameters, these studies placed the focus largely on the intermediate structures, in the form of the intact liquid jet (ILJ), while also quantifying the resulting drop diameters. The location and shape of the ILJ constantly change, and on its surface, wavelengths were seen to form and grow, which have been correlated to the resulting drop diameters in previous studies. The studies enclosed herein are unique in that they attempt to apply and explain exiting mechanism-based breakup mechanisms to regimes, fluids, and geometry changes not yet evaluated in the literature. Existing correlations were compared to the experimental data for a range of atomizer geometries, and when they were found lacking, Buckingham-(Pi) theorem was used to develop new correlations for predicting behavior. Additionally, the method developed for the calculation of these parameters for other image sets is included, allowing for easy comparison and value verification. A small-scale, coaxial atomization system was used to atomize water and two silicone oils with air. The atomizers used in these studies had the same general geometry type, but had varying sizes, allowing for the effect of both scale and geometry to be evaluated. These studies quantified instability development and growth along with the resulting spray characteristics, allowing for correlations to be made between the two data sets as the more recent mechanism-based atomization models do. Existing mechanism-based models from the literature are compared to the experimental results, as these existing models have not been evaluated significantly with changing atomizer geometry, high-viscosity fluids, and high flow regimes as was done here. Additionally, two experimental campaigns were undertaken with atomizers used to operate the University of Utah's PDU-scale (process development unit) entrained flow gasifier. The first campaign showed the effect of gas velocity, atomizer load (total flow), and gas-liquid impingement angle on the qualitative cold-flow atomizer performance. These trends are then tied to behavior of the entrained flow gasifier, showing the existence of a minimum required degree of atomization to avoid substantial losses in fuel conversion and efficiency in a gasifier. The second campaign showed the effect of gas flow, liquid flow, and fluid on the quantitative cold-flow atomizer performance. While in the literature, changing fluid properties of Newtonian fluids are shown to have a relatively linear response on atomizer performance, the behavior of non-Newtonian fluids was shown to be much more complex and difficult to predict. The correlations developed for the small-scale atomizers are applied to the micro-hole atomizers and found to be erroneous for the change in atomizer geometry. Buckingham-(Pi) theorem is then used to develop correlations to predict the spray Sauter mean diameter for the micro-hole atomizers. Slurry-fed combustion and gasification systems are but one industrial implementation of atomization. Atomization plays important roles in numerous other industries, and despite decades of study, it is not well understood. This document serves to shed some light on a few small, specific subsets of the topic.

Coexistence of species with different dispersal across landscapes: a critical role of spatial correlation in disturbance.

PubMed

Liao, Jinbao; Ying, Zhixia; Woolnough, Daelyn A; Miller, Adam D; Li, Zhenqing; Nijs, Ivan

2016-05-11

Disturbance is key to maintaining species diversity in plant communities. Although the effects of disturbance frequency and extent on species diversity have been studied, we do not yet have a mechanistic understanding of how these aspects of disturbance interact with spatial structure of disturbance to influence species diversity. Here we derive a novel pair approximation model to explore competitive outcomes in a two-species system subject to spatially correlated disturbance. Generally, spatial correlation in disturbance favoured long-range dispersers, while distance-limited dispersers were greatly suppressed. Interestingly, high levels of spatial aggregation of disturbance promoted long-term species coexistence that is not possible in the absence of disturbance, but only when the local disperser was intrinsically competitively superior. However, spatial correlation in disturbance led to different competitive outcomes, depending on the disturbed area. Concerning ecological conservation and management, we theoretically demonstrate that introducing a spatially correlated disturbance to the system or altering an existing disturbance regime can be a useful strategy either to control species invasion or to promote species coexistence. Disturbance pattern analysis may therefore provide new insights into biodiversity conservation. © 2016 The Author(s).

Diametrical clustering for identifying anti-correlated gene clusters.

PubMed

Dhillon, Inderjit S; Marcotte, Edward M; Roshan, Usman

2003-09-01

Clustering genes based upon their expression patterns allows us to predict gene function. Most existing clustering algorithms cluster genes together when their expression patterns show high positive correlation. However, it has been observed that genes whose expression patterns are strongly anti-correlated can also be functionally similar. Biologically, this is not unintuitive-genes responding to the same stimuli, regardless of the nature of the response, are more likely to operate in the same pathways. We present a new diametrical clustering algorithm that explicitly identifies anti-correlated clusters of genes. Our algorithm proceeds by iteratively (i). re-partitioning the genes and (ii). computing the dominant singular vector of each gene cluster; each singular vector serving as the prototype of a 'diametric' cluster. We empirically show the effectiveness of the algorithm in identifying diametrical or anti-correlated clusters. Testing the algorithm on yeast cell cycle data, fibroblast gene expression data, and DNA microarray data from yeast mutants reveals that opposed cellular pathways can be discovered with this method. We present systems whose mRNA expression patterns, and likely their functions, oppose the yeast ribosome and proteosome, along with evidence for the inverse transcriptional regulation of a number of cellular systems.

Temporal evolution of total ozone and circulation patterns over European mid-latitudes

NASA Astrophysics Data System (ADS)

Monge Sanz, B. M.; Casale, G. R.; Palmieri, S.; Siani, A. M.

2003-04-01

Linear correlation analysis and the running correlation technique are used to investigate the interannual and interdecadal variations of total ozone (TO) over several mid-latitude European locations. The study includes the longest series of ozone data, that of the Swiss station of Arosa. TO series have been related to time series of two circulation indices, the North Atlantic Oscillation Index (NAOI) and the Arctic Oscillation Index (AOI). The analysis has been performed with monthly data, and both series containing all the months of the year and winter (DJFM) series have been used. Special attention has been given to winter series, which exhibit very high correlation coefficients with NAOI and AOI; interannual variations of this relationship are studied by applying the running correlation technique. TO and circulation indices data series have been also partitioned into their different time-scale components with the Kolmogorov-Zurbenko method. Long-term components indicate the existence of strong opposite connection between total ozone and circulation patterns over the studied region during the last three decades. However, it is also observed that this relation has not always been so, and in previous times differences in the correlation amplitude and sign have been detected.

Tunable emergent heterostructures in a prototypical correlated metal

NASA Astrophysics Data System (ADS)

Fobes, D. M.; Zhang, S.; Lin, S.-Z.; Das, Pinaki; Ghimire, N. J.; Bauer, E. D.; Thompson, J. D.; Harriger, L. W.; Ehlers, G.; Podlesnyak, A.; Bewley, R. I.; Sazonov, A.; Hutanu, V.; Ronning, F.; Batista, C. D.; Janoschek, M.

2018-05-01

At the interface between two distinct materials, desirable properties, such as superconductivity, can be greatly enhanced1, or entirely new functionalities may emerge2. Similar to in artificially engineered heterostructures, clean functional interfaces alternatively exist in electronically textured bulk materials. Electronic textures emerge spontaneously due to competing atomic-scale interactions3, the control of which would enable a top-down approach for designing tunable intrinsic heterostructures. This is particularly attractive for correlated electron materials, where spontaneous heterostructures strongly affect the interplay between charge and spin degrees of freedom4. Here we report high-resolution neutron spectroscopy on the prototypical strongly correlated metal CeRhIn5, revealing competition between magnetic frustration and easy-axis anisotropy—a well-established mechanism for generating spontaneous superstructures5. Because the observed easy-axis anisotropy is field-induced and anomalously large, it can be controlled efficiently with small magnetic fields. The resulting field-controlled magnetic superstructure is closely tied to the formation of superconducting6 and electronic nematic textures7 in CeRhIn5, suggesting that in situ tunable heterostructures can be realized in correlated electron materials.

Evaluation of Dewatering Performance and Fractal Characteristics of Alum Sludge

PubMed Central

Sun, Yongjun; Fan, Wei; Zheng, Huaili; Zhang, Yuxin; Li, Fengting; Chen, Wei

2015-01-01

The dewatering performance and fractal characteristics of alum sludge from a drinking-water treatment plant were investigated in this study. Variations in residual turbidity of supernatant, dry solid content (DS), specific resistance to filtration (SRF), floc size, fractal dimension, and zeta potential were analyzed. Sludge dewatering efficiency was evaluated by measuring both DS and SRF. Results showed that the optimum sludge dewatering efficiency was achieved at 16 mg∙L-1 flocculant dosage and pH 7. Under these conditions, the maximum DS was 54.6%, and the minimum SRF was 0.61 × 1010 m∙kg-1. Floc-size measurements demonstrated that high flocculant dosage significantly improved floc size. Correlation analysis further revealed a strong correlation between fractal dimension and floc size after flocculation. A strong correlation also existed between floc size and zeta potential, and flocculants with a higher cationic degree had a larger correlation coefficient between floc size and zeta potential. In the flocculation process, the main flocculation mechanisms involved adsorption bridging under an acidic condition, and a combination between charge neutralization and adsorption-bridging interaction under neutral and alkaline conditions. PMID:26121132

Tunable emergent heterostructures in a prototypical correlated metal

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

Fobes, D. M.; Zhang, S.; Lin, S. -Z.

We report at the interface between two distinct materials, desirable properties, such as superconductivity, can be greatly enhanced1, or entirely new functionalities may emerge. Similar to in artificially engineered heterostructures, clean functional interfaces alternatively exist in electronically textured bulk materials. Electronic textures emerge spontaneously due to competing atomic-scale interactions, the control of which would enable a top-down approach for designing tunable intrinsic heterostructures. This is particularly attractive for correlated electron materials, where spontaneous heterostructures strongly affect the interplay between charge and spin degrees of freedom. Here we report high-resolution neutron spectroscopy on the prototypical strongly correlated metal CeRhIn 5, revealingmore » competition between magnetic frustration and easy-axis anisotropy—a well-established mechanism for generating spontaneous superstructures. Because the observed easy-axis anisotropy is field-induced and anomalously large, it can be controlled efficiently with small magnetic fields. Finally, the resulting field-controlled magnetic superstructure is closely tied to the formation of superconducting and electronic nematic textures in CeRhIn 5, suggesting that in situ tunable heterostructures can be realized in correlated electron materials.« less

An improved correlation to predict molecular weight between crosslinks based on equilibrium degree of swelling of hydrogel networks.

PubMed

Jimenez-Vergara, Andrea C; Lewis, John; Hahn, Mariah S; Munoz-Pinto, Dany J

2018-04-01

Accurate characterization of hydrogel diffusional properties is of substantial importance for a range of biotechnological applications. The diffusional capacity of hydrogels has commonly been estimated using the average molecular weight between crosslinks (M c ), which is calculated based on the equilibrium degree of swelling. However, the existing correlation linking M c and equilibrium swelling fails to accurately reflect the diffusional properties of highly crosslinked hydrogel networks. Also, as demonstrated herein, the current model fails to accurately predict the diffusional properties of hydrogels when polymer concentration and molecular weight are varied simultaneously. To address these limitations, we evaluated the diffusional properties of 48 distinct hydrogel formulations using two different photoinitiator systems, employing molecular size exclusion as an alternative methodology to calculate average hydrogel mesh size. The resulting data were then utilized to develop a revised correlation between M c and hydrogel equilibrium swelling that substantially reduces the limitations associated with the current correlation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1339-1348, 2018. © 2017 Wiley Periodicals, Inc.

Tunable emergent heterostructures in a prototypical correlated metal

DOE PAGES

Fobes, D. M.; Zhang, S.; Lin, S. -Z.; ...

2018-03-26

We report at the interface between two distinct materials, desirable properties, such as superconductivity, can be greatly enhanced1, or entirely new functionalities may emerge. Similar to in artificially engineered heterostructures, clean functional interfaces alternatively exist in electronically textured bulk materials. Electronic textures emerge spontaneously due to competing atomic-scale interactions, the control of which would enable a top-down approach for designing tunable intrinsic heterostructures. This is particularly attractive for correlated electron materials, where spontaneous heterostructures strongly affect the interplay between charge and spin degrees of freedom. Here we report high-resolution neutron spectroscopy on the prototypical strongly correlated metal CeRhIn 5, revealingmore » competition between magnetic frustration and easy-axis anisotropy—a well-established mechanism for generating spontaneous superstructures. Because the observed easy-axis anisotropy is field-induced and anomalously large, it can be controlled efficiently with small magnetic fields. Finally, the resulting field-controlled magnetic superstructure is closely tied to the formation of superconducting and electronic nematic textures in CeRhIn 5, suggesting that in situ tunable heterostructures can be realized in correlated electron materials.« less

Comparison of analytical and experimental subsonic steady and unsteady pressure distributions for a high-aspect-ratio-supercritical wing model with oscillating control surfaces

NASA Technical Reports Server (NTRS)

Mccain, W. E.

1982-01-01

The results of a comparative study using the unsteady aerodynamic lifting surface theory, known as the Doublet Lattice method, and experimental subsonic steady- and unsteady-pressure measurements, are presented for a high-aspect-ratio supercritical wing model. Comparisons of pressure distributions due to wing angle of attack and control-surface deflections were made. In general, good correlation existed between experimental and theoretical data over most of the wing planform. The more significant deviations found between experimental and theoretical data were in the vicinity of control surfaces for both static and oscillatory control-surface deflections.

Functional inverted Wishart for Bayesian multivariate spatial modeling with application to regional climatology model data.

PubMed

Duan, L L; Szczesniak, R D; Wang, X

2017-11-01

Modern environmental and climatological studies produce multiple outcomes at high spatial resolutions. Multivariate spatial modeling is an established means to quantify cross-correlation among outcomes. However, existing models typically suffer from poor computational efficiency and lack the flexibility to simultaneously estimate auto- and cross-covariance structures. In this article, we undertake a novel construction of covariance by utilizing spectral convolution and by imposing an inverted Wishart prior on the cross-correlation structure. The cross-correlation structure with this functional inverted Wishart prior flexibly accommodates not only positive but also weak or negative associations among outcomes while preserving spatial resolution. Furthermore, the proposed model is computationally efficient and produces easily interpretable results, including the individual autocovariances and full cross-correlation matrices, as well as a partial cross-correlation matrix reflecting the outcome correlation after excluding the effects caused by spatial convolution. The model is examined using simulated data sets under different scenarios. It is also applied to the data from the North American Regional Climate Change Assessment Program, examining long-term associations between surface outcomes for air temperature, pressure, humidity, and radiation, on the land area of the North American West Coast. Results and predictive performance are compared with findings from approaches using convolution only or coregionalization.

Functional inverted Wishart for Bayesian multivariate spatial modeling with application to regional climatology model data

PubMed Central

Duan, L. L.; Szczesniak, R. D.; Wang, X.

2018-01-01

Modern environmental and climatological studies produce multiple outcomes at high spatial resolutions. Multivariate spatial modeling is an established means to quantify cross-correlation among outcomes. However, existing models typically suffer from poor computational efficiency and lack the flexibility to simultaneously estimate auto- and cross-covariance structures. In this article, we undertake a novel construction of covariance by utilizing spectral convolution and by imposing an inverted Wishart prior on the cross-correlation structure. The cross-correlation structure with this functional inverted Wishart prior flexibly accommodates not only positive but also weak or negative associations among outcomes while preserving spatial resolution. Furthermore, the proposed model is computationally efficient and produces easily interpretable results, including the individual autocovariances and full cross-correlation matrices, as well as a partial cross-correlation matrix reflecting the outcome correlation after excluding the effects caused by spatial convolution. The model is examined using simulated data sets under different scenarios. It is also applied to the data from the North American Regional Climate Change Assessment Program, examining long-term associations between surface outcomes for air temperature, pressure, humidity, and radiation, on the land area of the North American West Coast. Results and predictive performance are compared with findings from approaches using convolution only or coregionalization. PMID:29576735

Tabu Search enhances network robustness under targeted attacks

NASA Astrophysics Data System (ADS)

Sun, Shi-wen; Ma, Yi-lin; Li, Rui-qi; Wang, Li; Xia, Cheng-yi

2016-03-01

We focus on the optimization of network robustness with respect to intentional attacks on high-degree nodes. Given an existing network, this problem can be considered as a typical single-objective combinatorial optimization problem. Based on the heuristic Tabu Search optimization algorithm, a link-rewiring method is applied to reconstruct the network while keeping the degree of every node unchanged. Through numerical simulations, BA scale-free network and two real-world networks are investigated to verify the effectiveness of the proposed optimization method. Meanwhile, we analyze how the optimization affects other topological properties of the networks, including natural connectivity, clustering coefficient and degree-degree correlation. The current results can help to improve the robustness of existing complex real-world systems, as well as to provide some insights into the design of robust networks.

Adolescents' lifetime experience of selling sex: development over five years.

PubMed

Fredlund, Cecilia; Svensson, Frida; Svedin, Carl Göran; Priebe, Gisela; Wadsby, Marie

2013-01-01

Lifetime experience of selling sex among adolescents was investigated together with sociodemographic correlates, parent-child relationship, and the existence of people to confide in. Changes over time regarding the selling of sex were investigated through a comparison of data from 2004 and 2009. This study was carried out using 3,498 adolescents from a representative sample of Swedish high school students with a mean age 18.3 years. Of these adolescents, 1.5% stated that they had given sexual services for reimbursement and both male and female buyers existed. The adolescents who had sold sex had a poorer parent-child relationship during childhood and had fewer people to confide in about problems and worries. Changes over time were found especially regarding the Internet as a contact source and also immigrant background.

Magnification-temperature correlation: The dark side of integrated Sachs-Wolfe measurements

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

LoVerde, Marilena; Hui, Lam; Gaztanaga, Enrique

2007-02-15

Integrated Sachs-Wolfe (ISW) measurements, which involve cross-correlating the microwave background anisotropies with the foreground large-scale structure (e.g. traced by galaxies/quasars), have proven to be an interesting probe of dark energy. We show that magnification bias, which is the inevitable modulation of the foreground number counts by gravitational lensing, alters both the scale dependence and amplitude of the observed ISW signal. This is true especially at high redshifts because (1) the intrinsic galaxy-temperature signal diminishes greatly back in the matter-dominated era, (2) the lensing efficiency increases with redshift and (3) the number count slope generally steepens with redshift in a magnitudemore » limited sample. At z > or approx. 2, the magnification-temperature correlation dominates over the intrinsic galaxy-temperature correlation and causes the observed ISW signal to increase with redshift, despite dark energy subdominance--a result of the fact that magnification probes structures all the way from the observer to the sources. Ignoring magnification bias therefore can lead to (significantly) erroneous conclusions about dark energy. While the lensing modulation opens up an interesting high z window for ISW measurements, high redshift measurements are not expected to add much new information to low redshift ones if dark energy is indeed the cosmological constant. This is because lensing introduces significant covariance across redshifts. The most compelling reasons for pursuing high redshift ISW measurements are to look for potential surprises such as early dark energy domination or signatures of modified gravity. We conclude with a discussion of existing measurements, the highest redshift of which is at the margin of being sensitive to the magnification effect. We also develop a formalism which might be of more general interest: to predict biases in estimating parameters when certain physical effects are ignored in interpreting observations.« less

Experimental witness of genuine high-dimensional entanglement

NASA Astrophysics Data System (ADS)

Guo, Yu; Hu, Xiao-Min; Liu, Bi-Heng; Huang, Yun-Feng; Li, Chuan-Feng; Guo, Guang-Can

2018-06-01

Growing interest has been invested in exploring high-dimensional quantum systems, for their promising perspectives in certain quantum tasks. How to characterize a high-dimensional entanglement structure is one of the basic questions to take full advantage of it. However, it is not easy for us to catch the key feature of high-dimensional entanglement, for the correlations derived from high-dimensional entangled states can be possibly simulated with copies of lower-dimensional systems. Here, we follow the work of Kraft et al. [Phys. Rev. Lett. 120, 060502 (2018), 10.1103/PhysRevLett.120.060502], and present the experimental realizing of creation and detection, by the normalized witness operation, of the notion of genuine high-dimensional entanglement, which cannot be decomposed into lower-dimensional Hilbert space and thus form the entanglement structures existing in high-dimensional systems only. Our experiment leads to further exploration of high-dimensional quantum systems.

Graphical correlation of gaging-station records

USGS Publications Warehouse

Searcy, James K.

1960-01-01

A gaging-station record is a sample of the rate of flow of a stream at a given site. This sample can be used to estimate the magnitude and distribution of future flows if the record is long enough to be representative of the long-term flow of the stream. The reliability of a short-term record for estimating future flow characteristics can be improved through correlation with a long-term record. Correlation can be either numerical or graphical, but graphical correlation of gaging-station records has several advantages. The graphical correlation method is described in a step-by-step procedure with an illustrative problem of simple correlation, illustrative problems of three examples of multiple correlation--removing seasonal effect--and two examples of correlation of one record with two other records. Except in the problem on removal of seasonal effect, the same group of stations is used in the illustrative problems. The purpose of the problems is to illustrate the method--not to show the improvement that can result from multiple correlation as compared with simple correlation. Hydrologic factors determine whether a usable relation exists between gaging-station records. Statistics is only a tool for evaluating and using an existing relation, and the investigator must be guided by a knowledge of hydrology.

Head injury as a PTSD predictor among Oklahoma City bombing survivors.

PubMed

Walilko, Timothy; North, Carol; Young, Lee Ann; Lux, Warren E; Warden, Deborah L; Jaffee, Michael S; Moore, David F

2009-12-01

The aim of the Oklahoma City (OKC) bombing retrospective review was to investigate the relationship between physical injury, environmental contributors, and psychiatric disorders such as posttraumatic stress disorder (PTSD) in an event-based, matched design study focused on injury. The 182 selected participants were a random subset of the 1,092 direct survivors from the OKC bombing. Only 124 of these 182 cases had a full complement of medical/clinical data in the OKC database. These 124 cases were assessed to explore relationships among PTSD diagnoses, levels of blast exposure, and physical injuries. Associations among variables were statistically tested using contingency analysis and logistic regression. Comparison of the PTSD cases to symptoms/diagnoses reported in the medical records reveals a statistically significant association between PTSD and head/brain injuries associated with head acceleration. PTSD was not highly correlated with other injuries. Although blast pressure and impulse were highly correlated with head injuries, the correlation with PTSD was not statistically significant. Thus, a correlation between blast pressure and PTSD may exist, but higher fidelity pressure calculations are required to elucidate this potential relationship. This study provides clear evidence that head injury is associated with subsequent PTSD, giving caregivers' information on what physical injuries may suggest the development of psychologic disorders to aid them in developing a profile for the identification of future survivors of terrorist attacks and Warfighters with brain injuries and potential PTSD.

Does selection in a challenging environment produce Nile tilapia genotypes that can thrive in a range of production systems?

PubMed Central

Thoa, Ngo Phu; Ninh, Nguyen Huu; Knibb, Wayne; Nguyen, Nguyen Hong

2016-01-01

This study assessed whether selection for high growth in a challenging environment of medium salinity produces tilapia genotypes that perform well across different production environments. We estimated the genetic correlations between trait expressions in saline and freshwater using a strain of Nile tilapia selected for fast growth under salinity water of 15–20 ppt. We also estimated the heritability and genetic correlations for new traits of commercial importance (sexual maturity, feed conversion ratio, deformity and gill condition) in a full pedigree comprising 36,145 fish. The genetic correlations for the novel characters between the two environments were 0.78–0.99, suggesting that the effect of genotype by environment interaction was not biologically important. Across the environments, the heritability for body weight was moderate to high (0.32–0.62), indicating that this population will continue responding to future selection. The estimates of heritability for sexual maturity and survival were low but significant. The additive genetic components also exist for FCR, gill condition and deformity. Genetic correlations of harvest body weight with sexual maturity were positive and those between harvest body weight with FCR were negative. Our results indicate that the genetic line selected under a moderate saline water environment can be cultured successfully in freshwater systems. PMID:26892814

Correlation of dickkopf-1 concentrations in plasma and synovial fluid to the severity of radiographic signs of equine osteoarthritis.

PubMed

Mills, Jillian S; Kinsley, Marc A; Peters, Duncan F; Weber, Patty S D; Shearer, Tara R; Pease, Anthony P

2017-09-12

The purpose of this study was to determine whether there was a correlation between circulating and intra-synovial Dkk-1 and radiographic signs of equine osteoarthritis. Circulating and intra-synovial Dkk-1 levels were measured in clinical cases using a commercially available human Dkk-1 ELISA. Radiographs were performed of the joints from which fluid was collected and these were assessed and scored by a boarded radiologist for joint narrowing, subchondral bone sclerosis, subchondral bone lysis, and periarticular modelling. Comparisons were made between radiographic scores and the concentrations of Dkk-1 using a Kruskal-Wallis one-way ANOVA. Correlations were calculated using Kendall's statistic. A total of 42 synovial fluid samples from 21 horses were collected and used in the analysis. No significant correlation was identified between Dkk-1 concentrations and radiographic signs of osteoarthritis. Intra-synovial Dkk-1 concentrations were significantly greater (p <0.001) in low motion joints (mean concentration, 232.68 pg/mL; range, 109.07-317.17) when compared to high-motion joints (28.78 pg/mL; 0.05-186.44 pg/mL) (p <0.001). Low motion joints have significantly higher concentrations of Dkk-1 compared to high motion joints. Further research is needed to establish the importance of this finding and whether potential diagnostic or therapeutic applications of Dkk-1 exist in the horse.

Evidence of Adverse Selection in Iranian Supplementary Health Insurance Market

PubMed Central

Mahdavi, Gh; Izadi, Z

2012-01-01

Background: Existence or non-existence of adverse selection in insurance market is one of the important cases that have always been considered by insurers. Adverse selection is one of the consequences of asymmetric information. Theory of adverse selection states that high-risk individuals demand the insurance service more than low risk individuals do. Methods: The presence of adverse selection in Iran’s supplementary health insurance market is tested in this paper. The study group consists of 420 practitioner individuals aged 20 to 59. We estimate two logistic regression models in order to determine the effect of individual’s characteristics on decision to purchase health insurance coverage and loss occurrence. Using the correlation between claim occurrence and decision to purchase health insurance, the adverse selection problem in Iranian supplementary health insurance market is examined. Results: Individuals with higher level of education and income level purchase less supplementary health insurance and make fewer claims than others make and there is positive correlation between claim occurrence and decision to purchase supplementary health insurance. Conclusion: Our findings prove the evidence of the presence of adverse selection in Iranian supplementary health insurance market. PMID:23113209

[Effects of root-knot nematodes on cucumber leaf N and P contents, soil pH, and soil enzyme activities].

PubMed

Xu, Hua; Ruan, Wei-Bin; Gao, Yu-Bao; Song, Xiao-Yan; Wei, Yu-Kun

2010-08-01

A pot experiment was conducted to study the effects of inoculation with root-knot nematodes on the cucumber leaf N and P contents, and the rhizospheric and non-rhizospheric soil pH and enzyme activities. The rhizospheric soil pH didn't have a significant decrease until the inoculation rate reached 6000 eggs per plant. With the increase of inoculation rate, the leaf N and P contents, rhizospheric soil peroxidase activity, and rhizospheric and non-rhizospheric soil polyphenol oxidase activity all decreased gradually, rhizospheric soil catalase activity was in adverse, non-rhizospheric soil pH decreased after an initial increase, and non-rhizospheric soil catalase activity had no regular change. After inoculation, rhizospheric soil urease activity decreased significantly, but rhizospheric and non-rhizospheric soil phosphatase activity and non-rhizospheric soil peroxidase activity only had a significant decrease under high inoculation rate. In most cases, there existed significant correlations between rhizospheric soil pH, enzyme activities, and leaf N and P contents; and in some cases, there existed significant correlations between non-rhizospheric soil pH, enzyme activities, and leaf N and P contents.

A phylogeographic study of the endemic rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of Northern Madagascar.

PubMed

Rakotoarisoa, Jean-Eric; Raheriarisena, Martin; Goodman, Steven M

2013-01-01

We conducted a mitochondrial phylogeographic study of the endemic dry forest rodent Eliurus carletoni (Rodentia: Nesomyinae) in an ecological transition zone of northern Madagascar (Loky-Manambato) and 2 surrounding regions (Ankarana and Analamerana). The main goal was to assess the evolutionary consequences on this taxon of the complex landscape features and Quaternary ecological vicissitudes. Three haplogroups were identified from the 215 specimens obtained from 15 populations. High levels of genetic diversity and significant genetic differentiation among populations were observed. The different geographical subdivisions of the study area by regions, by river catchment zones, and the physical distance between populations are not correlated with genetic patterns. In contrast, population structure is mostly explained by the geographic distribution of the samples among existing forest blocks. E. carletoni experienced a genetic bottleneck between 18 750 and 7500 years BP, which correlates with periods when moister climates existed on the island. Overall, our data suggest that the complex genetic patterns of E. carletoni can be explained by Quaternary climatic vicissitudes that resulted in habitat fluctuations between dry and humid forests, as well as subsequent human-induced fragmentation of forest habitat.

Effect of volatile hydrocarbon fractions on mobility and earthworm uptake of polycyclic aromatic hydrocarbons from soils and soil/lampblack mixtures.

PubMed

Bogan, Bill W; Beardsley, Kate E; Sullivan, Wendy R; Hayes, Thomas D; Soni, Bhupendra K

2005-01-01

Studies were conducted to examine the mobility and bioavailability to earthworms (Eisenia fetida) of priority pollutant polycyclic aromatic hydrocarbons (PAH) in a suite of 11 soils and soil/lampblack mixtures obtained from former manufactured-gas plant sites. Contaminant mobility was assessed using XAD4 resins encapsulated in dialysis tubing, which were exposed to slurried soils for 15 d. These experiments showed that mobility of PAH in the different soils strongly correlated to the levels of volatile hydrocarbons (namely, gasoline- and diesel-range organics [GRO and DRO]) that existed in the soils as co-contaminants. Actual PAH bioavailability (as measured by earthworm PAH concentrations) also appeared to depend on GRO + DRO levels, although this was most evident at high levels of these contaminants. These findings are discussed in view of the effects of dieselrange organics on oil viscosity, assuming that the hydrocarbon contaminants in these soils exist in the form of distinct adsorbed oil phases. This study, therefore, extends correlations between carrier-oil viscosity and dissolved solute bioavailability, previously observed in a number of other in vitro and whole-organism tests (and in bacterial mutagenicity studies in soil), to multicellular organisms inhabiting contaminated-soil systems.

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

Sridharan, Niyanth; Gussev, Maxim; Seibert, Rachel

Ultrasonic additive manufacturing (UAM) is a solid-state process, which uses ultrasonic vibrations at 20 kHz along with mechanized tape layering and intermittent milling operation, to build fully functional three-dimensional parts. In the literature, UAM builds made with low power (1.5 kW) exhibited poor tensile properties in Z-direction, i.e., normal to the interfaces. This reduction in properties is often attributed to the lack of bonding at faying interfaces. The generality of this conclusion is evaluated further in 6061 aluminum alloy builds made with very high power UAM (9 kW). Tensile deformation behavior along X and Z directions were evaluated with small-scalemore » in-situ mechanical testing equipped with high-resolution digital image correlation, as well as, multi-scale characterization of builds. Interestingly, even with complete metallurgical bonding across the interfaces without any discernable voids, poor Z-direction properties were observed. This reduction is correlated to coalescence of pre-existing shear bands at interfaces into micro voids, leading to strain localization and spontaneous failure on tensile loading.« less

High-definition reconstruction of clonal composition in cancer.

PubMed

Fischer, Andrej; Vázquez-García, Ignacio; Illingworth, Christopher J R; Mustonen, Ville

2014-06-12

The extensive genetic heterogeneity of cancers can greatly affect therapy success due to the existence of subclonal mutations conferring resistance. However, the characterization of subclones in mixed-cell populations is computationally challenging due to the short length of sequence reads that are generated by current sequencing technologies. Here, we report cloneHD, a probabilistic algorithm for the performance of subclone reconstruction from data generated by high-throughput DNA sequencing: read depth, B-allele counts at germline heterozygous loci, and somatic mutation counts. The algorithm can exploit the added information present in correlated longitudinal or multiregion samples and takes into account correlations along genomes caused by events such as copy-number changes. We apply cloneHD to two case studies: a breast cancer sample and time-resolved samples of chronic lymphocytic leukemia, where we demonstrate that monitoring the response of a patient to therapy regimens is feasible. Our work provides new opportunities for tracking cancer development. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Time-invariant discord: high temperature limit and initial environmental correlations

NASA Astrophysics Data System (ADS)

Tabesh, F. T.; Karpat, G.; Maniscalco, S.; Salimi, S.; Khorashad, A. S.

2018-04-01

We present a thorough investigation of the phenomena of frozen and time-invariant quantum discord for two-qubit systems independently interacting with local reservoirs. Our work takes into account several significant effects present in decoherence models, which have not been yet explored in the context of time-invariant quantum discord, but which in fact must be typically considered in almost all realistic models. Firstly, we study the combined influence of dephasing, dissipation and heating reservoirs at finite temperature. Contrarily to previous claims in the literature, we show the existence of time-invariant discord at high temperature limit in the weak coupling regime and also examine the effect of thermal photons on the dynamical behavior of frozen discord. Secondly, we explore the consequences of having initial correlations between the dephasing reservoirs. We demonstrate in detail how the time-invariant discord is modified depending on the relevant system parameters such as the strength of the initial amount of entanglement between the reservoirs.

Impact of formation water geochemistry and crude oil biodegradation on microbial methanogenesis

USGS Publications Warehouse

Shelton, Jenna L.; McIntosh, Jennifer C.; Warwick, Peter D.; McCray, John E.

2016-01-01

Shallow wells (393–442 m depth) contained highly biodegraded oils associated with low extent of methanogenesis, while the deepest (> 1208 m) wells contained minimally degraded oils and produced fluids suggesting a low extent of methanogenesis. Mid-depth wells (666–857 m) in the central field had the highest indicators of methanogenesis and contained moderately biodegraded oils. Little correlation existed between extents of crude oil biodegradation and methanogenesis across the whole transect (avg.R2 = 0.13). However, when wells with the greatest extent of crude oil biodegradation were eliminated (3 of 6 oilfields), better correlation between extent of methanogenesis and biodegradation (avg. R2 = 0.53) was observed. The results suggest that oil quality and salinity impact methanogenic crude oil biodegradation. Reservoirs indicating moderate extent of crude oil biodegradation and high extent of methanogenesis, such as the central field, would be good candidates for attempting to enhance methanogenic crude oil biodegradation as a result of the observations from the study.

Analysis-Preserving Video Microscopy Compression via Correlation and Mathematical Morphology

PubMed Central

Shao, Chong; Zhong, Alfred; Cribb, Jeremy; Osborne, Lukas D.; O’Brien, E. Timothy; Superfine, Richard; Mayer-Patel, Ketan; Taylor, Russell M.

2015-01-01

The large amount video data produced by multi-channel, high-resolution microscopy system drives the need for a new high-performance domain-specific video compression technique. We describe a novel compression method for video microscopy data. The method is based on Pearson's correlation and mathematical morphology. The method makes use of the point-spread function (PSF) in the microscopy video acquisition phase. We compare our method to other lossless compression methods and to lossy JPEG, JPEG2000 and H.264 compression for various kinds of video microscopy data including fluorescence video and brightfield video. We find that for certain data sets, the new method compresses much better than lossless compression with no impact on analysis results. It achieved a best compressed size of 0.77% of the original size, 25× smaller than the best lossless technique (which yields 20% for the same video). The compressed size scales with the video's scientific data content. Further testing showed that existing lossy algorithms greatly impacted data analysis at similar compression sizes. PMID:26435032

Consumption of fruits and vegetables in Malaysia: profiling the daily and nondaily consumers.

PubMed

Yen, Steven T; Tan, Andrew K G; Feisul, Mustapha I

2015-03-01

This study examines the sociodemographic factors associated with daily fruit and vegetable (FV) consumption in Malaysia. Based on a cross-sectional sample of 2447 individuals from the Malaysia Non-Communicable Disease Surveillance-1, a multivariate sample selection system is developed and estimated, to accommodate high frequencies of daily FV consumption and the days of servings among nondaily consumers. Results indicate that the authors' attempt to account for endogenous sample selectivity and cross-equation correlations is justified. There exist positive correlations between FV consumption likelihoods and longer work hours, higher levels of education, high income, female gender, nonsmoking status, and being from East Malaysia. Among nondaily consumers, those with longer work hours, singles, and people with diabetes are less inclined to eat fruits on more days. Overall, higher-educated, affluent people, nonsmokers, and East Malaysians display more days of FV consumption. Based on these outcomes, several policy implications are recommended vis-à-vis FV consumption patterns in Malaysia. © 2012 APJPH.

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

Fattoyev, F. J.; Piekarewicz, J.

The sensitivity of the stellar moment of inertia to the neutron-star matter equation of state is examined using accurately calibrated relativistic mean-field models. We probe this sensitivity by tuning both the density dependence of the symmetry energy and the high-density component of the equation of state, properties that are at present poorly constrained by existing laboratory data. Particularly attractive is the study of the fraction of the moment of inertia contained in the solid crust. Analytic treatments of the crustal moment of inertia reveal a high sensitivity to the transition pressure at the core-crust interface. This may suggest the existencemore » of a strong correlation between the density dependence of the symmetry energy and the crustal moment of inertia. However, no correlation was found. We conclude that constraining the density dependence of the symmetry energy - through, for example, the measurement of the neutron skin thickness in {sup 208}Pb - will place no significant bound on either the transition pressure or the crustal moment of inertia.« less

Telemedicine Versus Face-to-Face Evaluations by Respiratory Therapists of Mechanically Ventilated Neonates and Children: A Pilot Study.

PubMed

Bell, Rebecca C; Yager, Phoebe H; Clark, Maureen E; Roumiantsev, Serguei; Venancio, Heather L; Chipman, Daniel W; Kacmarek, Robert M; Noviski, Natan N

2016-02-01

Mechanical ventilation is one of the most important therapeutic interventions in neonatal and pediatric ICUs. Telemedicine has been shown to reliably extend pediatric intensivist expertise to facilities where expertise is limited. If reliable, telemedicine may extend the reach of pediatric respiratory therapists (RTs) to facilities where expertise does not exist or free up existing RT resources for important face-to-face activities in facilities where expertise is limited. The aim of this study was to determine how well respiratory assessments for ventilated neonates and children correlated when performed simultaneously by 2 RTs face-to-face and via telemedicine. We conducted a pilot study including 40 assessments by 16 RTs on 11 subjects (5 neonatal ICU; 6 pediatric ICU). Anonymously completed intake forms by 2 different RTs concurrently assessing 14 ventilator-derived and patient-based respiratory variables were used to determine correlations. Forty paired assessments were performed. Median telemedicine assessment time was 8 min. The Pearson correlation coefficient (r) was used to determine agreement between continuous data, and the Cohen kappa statistics were used for binary variables. Pressure control, PEEP, breathing frequency, and FIO2 perfectly correlated (r = 1, all P < .001) as did the presence of a CO2 monitor and need for increased ventilatory support (kappa = 1). The Pearson correlation coefficient for VT, minute ventilation, mean airway pressure, and oxygen saturation ranged from 0.84 to 0.97 (all P < .001). kappa = 0.41 (95% CI 0.02-0.80) for patient-triggered breaths, and kappa = 0.57 (95% CI 0.19-0.94) for breathing frequency higher than set frequency. kappa = -0.25 (95% CI -0.46 to -0.04) for need for suctioning. Telemedicine technology was acceptable to RTs. Telemedicine evaluations highly correlated with face-to-face for 10 of 14 aspects of standard bedside respiratory assessment. Poor correlation was noted for more complex, patient-generated parameters, highlighting the importance of further investigation incorporating a virtual stethoscope. Copyright © 2016 by Daedalus Enterprises.

A Solution to Separation and Multicollinearity in Multiple Logistic Regression

PubMed Central

Shen, Jianzhao; Gao, Sujuan

2010-01-01

In dementia screening tests, item selection for shortening an existing screening test can be achieved using multiple logistic regression. However, maximum likelihood estimates for such logistic regression models often experience serious bias or even non-existence because of separation and multicollinearity problems resulting from a large number of highly correlated items. Firth (1993, Biometrika, 80(1), 27–38) proposed a penalized likelihood estimator for generalized linear models and it was shown to reduce bias and the non-existence problems. The ridge regression has been used in logistic regression to stabilize the estimates in cases of multicollinearity. However, neither solves the problems for each other. In this paper, we propose a double penalized maximum likelihood estimator combining Firth’s penalized likelihood equation with a ridge parameter. We present a simulation study evaluating the empirical performance of the double penalized likelihood estimator in small to moderate sample sizes. We demonstrate the proposed approach using a current screening data from a community-based dementia study. PMID:20376286

A Solution to Separation and Multicollinearity in Multiple Logistic Regression.

PubMed

Shen, Jianzhao; Gao, Sujuan

2008-10-01

In dementia screening tests, item selection for shortening an existing screening test can be achieved using multiple logistic regression. However, maximum likelihood estimates for such logistic regression models often experience serious bias or even non-existence because of separation and multicollinearity problems resulting from a large number of highly correlated items. Firth (1993, Biometrika, 80(1), 27-38) proposed a penalized likelihood estimator for generalized linear models and it was shown to reduce bias and the non-existence problems. The ridge regression has been used in logistic regression to stabilize the estimates in cases of multicollinearity. However, neither solves the problems for each other. In this paper, we propose a double penalized maximum likelihood estimator combining Firth's penalized likelihood equation with a ridge parameter. We present a simulation study evaluating the empirical performance of the double penalized likelihood estimator in small to moderate sample sizes. We demonstrate the proposed approach using a current screening data from a community-based dementia study.

[Retrospective analysis of correlative factors between digestive system injury and anticoagulant or antiplatelet-agents].

PubMed

Cui, Ning; Luo, Hesheng

2014-05-27

To explore the correlative factors and clinical characteristics of digestive system injury during the treatment of anticoagulant and (or) antiplatelet-agents. A total of 1 443 hospitalized patients on anticoagulant and (or) antiplatelet-agents from January 2010 to December 2013 at Renmin Hospital of Wuhan University were analyzed retrospectively. Their length of hospital stay was from 5 to 27 days. Most of them were elderly males (n = 880, 61.0%) with an average age of (62 ± 6) years. 1 138 patients (78.9%) were farmers, workers or someone without a specific occupation. During the treatment of anticoagulant/antiplatelet-agents, statistical difference existed (P = 0.01) between positively and negatively previous digestive disease groups for actively newly occurring digestive system injury (16.0% (41/256) vs 15.9% (189/1 187)). After the dosing of anticoagulant and (or) antiplatelet-agents, 57 (66.3%, 57/86) patients were complicated by hemorrhage of digestive tract, taking 62.9% (61/97) of all positive result patients for Helicobacter pylori test. Comparing preventive PPI group with no PPI group, there was no marked statistical differences (P = 2.67) for digestive system complication (including hemorrhage of digestive tract) while receiving anticoagulant and (or) antiplatelet-agents (13.9% (74/533) vs 17.1% (156/910)). During anticoagulant and/or antiplatelet-agent therapy, 185 patients (12.8%) were complicated by peptic ulcer or peptic ulcer with bleeding, 40 patients (2.8%) had erosive gastritis and 5 (0.3%) developed acute gastric mucosal lesions. And 42 of 76 patients complicated by hemorrhage of digestive tract underwent endoscopic hemostasis while 2 patients were operated. Ninety-seven patients (6.7%) died, including 61 (62.9%, 61/97) from hemorrhage of digestive tract. The remainder became cured, improved and discharged. Moreover, no significant statistical differences existed (P = 2.29) among three combination group (aspirin, clopidogrel, warfarin), two combination group (aspirin, clopidogrel), exclusive aspirin group and exclusive warfarin group in short-term (<27 d) mortality. It is necessary to clearly dictate the details of medication to the patients not highly educated. Elder, male, history of digestive system disease and Helicobacter pylori infection are possibly highly risk correlative factors for digestive system complications during anticoagulant/antiplatelet-agent therapy. The short-term protective effect of routine dose of PPI is inconspicuous. No significant correlation exists between short-term mortality and the dosage (or type) of anticoagulant/antiplatelet-agents.

Correlates of previous couples' HIV counseling and testing uptake among married individuals in three HIV prevalence strata in Rakai, Uganda.

PubMed

Matovu, Joseph K B; Todd, Jim; Wanyenze, Rhoda K; Wabwire-Mangen, Fred; Serwadda, David

2015-01-01

Studies show that uptake of couples' HIV counseling and testing (couples' HCT) can be affected by individual, relationship, and socioeconomic factors. However, while couples' HCT uptake can also be affected by background HIV prevalence and awareness of the existence of couples' HCT services, this is yet to be documented. We explored the correlates of previous couples' HCT uptake among married individuals in a rural Ugandan district with differing HIV prevalence levels. This was a cross-sectional study conducted among 2,135 married individuals resident in the three HIV prevalence strata (low HIV prevalence: 9.7-11.2%; middle HIV prevalence: 11.4-16.4%; and high HIV prevalence: 20.5-43%) in Rakai district, southwestern Uganda, between November 2013 and February 2014. Data were collected on sociodemographic and behavioral characteristics, including previous receipt of couples' HCT. HIV testing data were obtained from the Rakai Community Cohort Study. We conducted multivariable logistic regression analysis to identify correlates that are independently associated with previous receipt of couples' HCT. Data analysis was conducted using STATA (statistical software, version 11.2). Of the 2,135 married individuals enrolled, the majority (n=1,783, 83.5%) had been married for five or more years while (n=1,460, 66%) were in the first-order of marriage. Ever receipt of HCT was almost universal (n=2,020, 95%); of those ever tested, (n=846, 41.9%) reported that they had ever received couples' HCT. There was no significant difference in previous receipt of couples' HCT between low (n=309, 43.9%), middle (n=295, 41.7%), and high (n=242, 39.7%) HIV prevalence settings (p=0.61). Marital order was not significantly associated with previous receipt of couples' HCT. However, marital duration [five or more years vis-à-vis 1-2 years: adjusted odds ratio (aOR): 1.06; 95% confidence interval (95% CI): 1.04-1.08] and awareness about the existence of couples' HCT services within the Rakai community cohort (aOR: 7.58; 95% CI: 5.63-10.20) were significantly associated with previous receipt of couples' HCT. Previous couples' HCT uptake did not significantly differ by HIV prevalence setting. Longer marital duration and awareness of the existence of couples' HCT services in the community were significantly correlated with previous receipt of couples' HCT. These findings suggest a need for innovative demand-creation interventions to raise awareness about couples' HCT service availability to improve couples' HCT uptake among married individuals.

Approximate correlations for chevron-type plate heat exchangers

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

Wanniarachchi, A.S.; Ratnam, U.; Tilton, B.E.

1995-12-31

There exists very little useful data representing the performance of industrial plate heat exchangers (PHEs) in the open literature. As a result, it has been difficult to arrive at any generalized correlations. While every PHE manufacturer is believed to have a comprehensive set of performance curves for their own designs, there exists the need to generate an approximate set of generalized correlations for the heat-transfer community. Such correlations can be used for preliminary designs and analytical studies. This paper attempts to develop such a set of generalized correlations to quantify the heat-transfer and pressure-drop performance of chevron-type PHEs. For thismore » purpose, the experimental data reported by Heavner et al. were used for the turbulent region. For the laminar region, a semi-theoretical approach was used to express, for example, the friction factor as a function of the Reynolds number and the chevron angle. Asymptotic curves were used for the transitional region. Physical explanations are provided for the trends shown by the generalized correlations. The correlations are compared against the open-literature data, where appropriate. These correlations are expected to be improved in the future when more data become available.« less

Structural Genomics: Correlation Blocks, Population Structure, and Genome Architecture

PubMed Central

Hu, Xin-Sheng; Yeh, Francis C.; Wang, Zhiquan

2011-01-01

An integration of the pattern of genome-wide inter-site associations with evolutionary forces is important for gaining insights into the genomic evolution in natural or artificial populations. Here, we assess the inter-site correlation blocks and their distributions along chromosomes. A correlation block is broadly termed as the DNA segment within which strong correlations exist between genetic diversities at any two sites. We bring together the population genetic structure and the genomic diversity structure that have been independently built on different scales and synthesize the existing theories and methods for characterizing genomic structure at the population level. We discuss how population structure could shape correlation blocks and their patterns within and between populations. Effects of evolutionary forces (selection, migration, genetic drift, and mutation) on the pattern of genome-wide correlation blocks are discussed. In eukaryote organisms, we briefly discuss the associations between the pattern of correlation blocks and genome assembly features in eukaryote organisms, including the impacts of multigene family, the perturbation of transposable elements, and the repetitive nongenic sequences and GC-rich isochores. Our reviews suggest that the observable pattern of correlation blocks can refine our understanding of the ecological and evolutionary processes underlying the genomic evolution at the population level. PMID:21886455

Dietary Phosphorus Intake and the Kidney

PubMed Central

Chang, Alex R.; Anderson, Cheryl

2017-01-01

Although phosphorus is an essential nutrient required for multiple physiological functions, recent research raises concerns that high phosphorus intake could have detrimental effects on health. Phosphorus is abundant in the food supply of developed countries, occurring naturally in protein-rich foods and as an additive in processed foods. High phosphorus intake can cause vascular and renal calcification, renal tubular injury, and premature death in multiple animal models. Small studies in human suggest that high phosphorus intake may result in positive phosphorus balance and correlate with renal calcification and albuminuria. Although serum phosphorus is strongly associated with cardiovascular disease, progression of kidney disease, and death, limited data exist linking high phosphorus intake directly to adverse clinical outcomes. Further prospective studies are needed to determine whether phosphorus intake is a modifiable risk factor for kidney disease. PMID:28613982

Business Metrics for High-Performance Homes: A Colorado Springs Case Study

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

Beach, R.; Jones, A.

The building industry needs to understand how energy ratings can impact homebuilders. Of interest is how energy efficiency may or may not have a positive impact on homebuilders’ business success. Focusing on Colorado Springs, Colorado, as a case study, the U.S. Department of Energy’s Building America research team IBACOS suggests a win–win between a builder’s investment in energy efficiency and that builder’s ability to sell homes. Although this research did not ultimately determine why a correlation may exist, a builder’s investment in voluntary energy-efficiency programs correlated with that builder’s ability to survive the Great Recession of 2007 to 2009. Thismore » report explores the relationship between energy-efficiency ratings and the market performance of several builders in Colorado Springs.« less

Optic Nerve Assessment Using 7-Tesla Magnetic Resonance Imaging.

PubMed

Singh, Arun D; Platt, Sean M; Lystad, Lisa; Lowe, Mark; Oh, Sehong; Jones, Stephen E; Alzahrani, Yahya; Plesec, Thomas

2016-04-01

The purpose of this study was to correlate high-resolution magnetic resonance imaging (MRI) and histologic findings in a case of juxtapapillary choroidal melanoma with clinical evidence of optic nerve invasion. With institutional review board approval, an enucleated globe with choroidal melanoma and optic nerve invasion was imaged using a 7-tesla MRI followed by histopathologic evaluation. Optical coherence tomography, B-scan ultrasonography, and 1.5-tesla MRI of the orbit (1-mm sections) could not detect optic disc invasion. Ex vivo, 7-tesla MRI detected optic nerve invasion, which correlated with histopathologic features. Our case demonstrates the potential to document the existence of optic nerve invasion in the presence of an intraocular tumor, a feature that has a major bearing on decision making, particularly for consideration of enucleation.

Negative Correlation Learning for Customer Churn Prediction: A Comparison Study

PubMed Central

Faris, Hossam

2015-01-01

Recently, telecommunication companies have been paying more attention toward the problem of identification of customer churn behavior. In business, it is well known for service providers that attracting new customers is much more expensive than retaining existing ones. Therefore, adopting accurate models that are able to predict customer churn can effectively help in customer retention campaigns and maximizing the profit. In this paper we will utilize an ensemble of Multilayer perceptrons (MLP) whose training is obtained using negative correlation learning (NCL) for predicting customer churn in a telecommunication company. Experiments results confirm that NCL based MLP ensemble can achieve better generalization performance (high churn rate) compared with ensemble of MLP without NCL (flat ensemble) and other common data mining techniques used for churn analysis. PMID:25879060

Correlations between wave activity and electron temperature in the Martian upper ionosphere

NASA Astrophysics Data System (ADS)

Fowler, Chris; Andersson, Laila; Ergun, Robert; Andrews, David

2017-04-01

Prior to the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, only two electron temperature profiles of the Martian ionosphere existed, made by the Viking landers in the late 70s. Since MAVENs arrival at Mars in late 2014, electron temperature (and density) profiles have been measured every orbit, once every 4.5 hours. Recent analysis of this new dataset has shown that the Martian ionospheric electron temperature is significantly warmer than expected by factors of 2-3 above the exobase and within the upper ionosphere. We present correlations between electron temperature and electric field wave power (also measured by MAVEN), and discuss the possibility that such waves (which are likely produced by the Mars-solar wind interaction) may drive electron heating and contribute to the observed high temperatures.

Lower thermosphere (80-100 km) dynamics response to solar and geomagnetic activity: Overview

NASA Technical Reports Server (NTRS)

Kazimirovsky, E. S.

1989-01-01

The variations of solar and geomagnetic activity may affect the thermosphere circulation via plasma heating and electric fields, especially at high latitudes. The possibility exists that the energy involved in auroral and magnetic storms can produce significant changes of mesosphere and lower thermosphere wind systems. A study of global radar measurements of winds at 80 to 100 km region revealed the short term effects (correlation between wind field and geomagnetic storms) and long term variations over a solar cycle. It seems likely that the correlation results from a modification of planetary waves and tides propagated from below, thus altering the dynamical regime of the thermosphere. Sometimes the long term behavior points rather to a climatic variation with the internal atmospheric cause than to a direct solar control.

Autocorrelation peaks in congruential pseudorandom number generators

NASA Technical Reports Server (NTRS)

Neuman, F.; Merrick, R. B.

1976-01-01

The complete correlation structure of several congruential pseudorandom number generators (PRNG) of the same type and small cycle length was studied to deal with the problem of congruential PRNG almost repeating themselves at intervals smaller than their cycle lengths, during simulation of bandpass filtered normal random noise. Maximum period multiplicative and mixed congruential generators were studied, with inferences drawn from examination of several tractable members of a class of random number generators, and moduli from 2 to the 5th power to 2 to the 9th power. High correlation is shown to exist in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle length. The random noise sequences in question are required when simulating electrical noise, air turbulence, or time variation of wind parameters.

Correlated phonons and the Tc-dependent dynamical phonon anomalies

NASA Astrophysics Data System (ADS)

Hakioğlu, T.; Türeci, H.

1997-11-01

Anomalously large low-temperature phonon anharmonicities can lead to static as well as dynamical changes in the low-temperature properties of the electron-phonon system. In this work, we focus our attention on the dynamically generated low-temperature correlations in an interacting electron-phonon system using a self-consistent dynamical approach in the intermediate coupling range. In the context of the model, the polaron correlations are produced by the charge-density fluctuations which are generated dynamically by the electron-phonon coupling. Conversely, the latter is influenced in the presence of the former. The purpose of this work is to examine the dynamics of this dual mechanism between the two using the illustrative Fröhlich model. In particular, the influence of the low-temperature phonon dynamics on the superconducting properties in the intermediate coupling range is investigated. The influence on the Holstein reduction factor as well as the enhancement in the zero-point fluctuations and in the electron-phonon coupling are calculated numerically. We also examine these effects in the presence of superconductivity. Within this model, the contribution of the electron-phonon interaction as one of the important elements in the mechanisms of superconductivity can reach values as high as 15-20% of the characteristic scale of the lattice vibrational energy. The second motivation of this work is to understand the nature of the Tc-dependent temperature anomalies observed in the Debye-Waller factor, dynamical pair correlations, and average atomic vibrational energies for a number of high-temperature superconductors. In our approach we do not claim nor believe that the electron-phonon interaction is the primary mechanism leading to high-temperature superconductivity. Nevertheless, our calculations suggest that the dynamically induced low-temperature phonon correlation model can account for these anomalies and illustrates their possible common origin. Finally, the relevance of incorporating these low-temperature effects into more realistic models of high-temperature superconductivity including both the charge and spin degrees and other similar ideas existing in the literature are discussed.

The Southern Oscillation and Prediction of `Der' Season Rainfall in Somalia.

NASA Astrophysics Data System (ADS)

Hutchinson, P.

1992-05-01

Somalia survives in semiarid to arid conditions, with annual rainfall totals rarely exceeding 700 mm, which are divided between two seasons. Many areas are arid, with negligible precipitation. Seasonal totals are highly variable. Thus, any seasonal rainfall forecast would be of significant importance to both the agricultural and animal husbandry communities. An investigation was carried out to determine whether there is a relationship between the Southern Oscillation and seasonal rainfall. No relationship exists between the Southern Oscillation and rainfall during the midyear `Gu' season, but it is shown that the year-end `Der' season precipitation is attected by the Southern Oscillation in southern and central areas of Somalia. Three techniques were used: correlation, regression, and simple contingency tables. Correlations between the SOI (Southern Oscillation index) and seasonal rainfall vary from zero up to about 0.8, with higher correlations in the south, both for individual stations and for area-averaged rainfall. Regression provides some predictive capacity, but the `explanation' of the variation in rainfall is not particularly high. The contingency tables revealed that there were very few occasions of both high SOI and high seasonal rainfall, although there was a wide scatter of seasonal rainfall associated with a low SOI.It is concluded that the SOI would be useful for planners, governments, and agencies as one tool in food/famine early warning but that the relationships are not strong enough for the average farmer to place much reliance on forecasts produced solely using the SOI.

Correlation studies of Pioneer Venus imagery obtained from PV experiments with near IR imagery obtained from ground-based observations during Venus inferior conjunction

NASA Technical Reports Server (NTRS)

Ragent, Boris

1993-01-01

The purpose of this study is to attempt to find correlations between data taken by experiments aboard the Pioneer-Venus Orbiter (PVO) and those obtained from Earth-based near-infrared (NIR) measurements of Venus during periods near inferior conjunction. Since the NIR measurements have been found to provide data on the middle atmosphere cloud morphology and motion, it is assumed that any correlations will also indicate that the PVO experiments are also documenting cloud behavior. If such correlations are found, then a further task is to attempt to study the long term behavior of the cloud features implied by the correlations. Many PVO data have been obtained over an extended period extending from 1978 until the PV demise in 1992. There exists a long, somewhat ill-conditioned time series of data that may contain valuable information on the long time, as well as short term behavior of the clouds, and, derivatively from cloud motion, atmospheric dynamics and wave activity in the Venus atmosphere. For example, determination of the zonal velocities of any OCPP (Cloud Photopolarimeter) 0.935 micron features could then be used for comparisons with data from other sources to attempt to fix the altitude region in which such features existed. A further task of this study is to attempt to correlate any features found in simultaneously obtained data, for example, the OCPP 0.365 and 0.935 micron data. The existence of such correlations may imply that data was obtained in overlapping altitude regions of the atmosphere.

Short-time windowed covariance: A metric for identifying non-stationary, event-related covariant cortical sites

PubMed Central

Blakely, Timothy; Ojemann, Jeffrey G.; Rao, Rajesh P.N.

2014-01-01

Background Electrocorticography (ECoG) signals can provide high spatio-temporal resolution and high signal to noise ratio recordings of local neural activity from the surface of the brain. Previous studies have shown that broad-band, spatially focal, high-frequency increases in ECoG signals are highly correlated with movement and other cognitive tasks and can be volitionally modulated. However, significant additional information may be present in inter-electrode interactions, but adding additional higher order inter-electrode interactions can be impractical from a computational aspect, if not impossible. New method In this paper we present a new method of calculating high frequency interactions between electrodes called Short-Time Windowed Covariance (STWC) that builds on mathematical techniques currently used in neural signal analysis, along with an implementation that accelerates the algorithm by orders of magnitude by leveraging commodity, off-the-shelf graphics processing unit (GPU) hardware. Results Using the hardware-accelerated implementation of STWC, we identify many types of event-related inter-electrode interactions from human ECoG recordings on global and local scales that have not been identified by previous methods. Unique temporal patterns are observed for digit flexion in both low- (10 mm spacing) and high-resolution (3 mm spacing) electrode arrays. Comparison with existing methods Covariance is a commonly used metric for identifying correlated signals, but the standard covariance calculations do not allow for temporally varying covariance. In contrast STWC allows and identifies event-driven changes in covariance without identifying spurious noise correlations. Conclusions: STWC can be used to identify event-related neural interactions whose high computational load is well suited to GPU capabilities. PMID:24211499

Geochemical patterns of arsenic-enriched ground water in fractured, crystalline bedrock, Northport, Maine, USA

USGS Publications Warehouse

Lipfert, G.; Reeve, A.S.; Sidle, W.C.; Marvinney, R.

2006-01-01

High mean As concentrations of up to 26.6 ??mol/L (1990 ??g/L) occur in ground water collected from a fractured-bedrock system composed of sulfidic schist with granitic to dioritic intrusions. Sulfides in the bedrock are the primary source of the As in the ground water, but the presence of arsenopyrite in rock core retrieved from a borehole with As concentrations in the ground water barely above the detection limit of 2.0 ??mol/L, shows that there are complicating factors. Chemical analyses of water from 35 bedrock wells throughout a small watershed reveal spatial clustering of wells with high As concentrations. Stiff diagrams and box plots distinguish three distinct types; calcium-bicarbonate-dominated water with low As concentrations (CaHCO 3 type), sodium-bicarbonate-dominated water with moderately high As concentrations (NaHCO3 type), and calcium-bicarbonate-dominated water with very high As concentrations (High-As type). It is proposed that differences in recharge area and ground-water evolution, and possible bedrock composition difference are responsible for the chemical distinctions within the watershed. Lack of correlation of As concentrations with pH indicates that desorption of As is an insignificant control on As concentration. Correlations of As concentrations with Fe and redox parameters indicates that reductive dissolution of Fe(III) oxyhydroxides may play a role in the occurrence of high As concentrations in the NaHCO3 and High-As type water. The oxidation of sulfide minerals occurs within the ground-water system and is ultimately responsible for the existence of As in the ground water, but there is no correlation between As and SO4 concentrations, probably due to precipitation of Fe(III) oxyhydroxides and adsorption of As under oxidizing conditions. Crown Copyright ?? 2006 Published by Elsevier Ltd. All rights reserved.

[Chemical forms and ecological effect of soil Mn in liver cancer's high incidence area in Zhu-jiang River Delta, China].

PubMed

Dou, Lei; Zhou, Yong-Zhang; Li, Yong; Ma, Jin; An, Yan-Fei; Du, Hai-Yan; Li, Zhan-Qiang

2008-06-01

The samples of surface soil, deep soil, and vegetables were collected from the liver cancer's high- and low incidence areas in Zhujiang River Delta to study the relationships between soil Mn forms and vegetables' Mn enrichment. The results showed that the soil Mn in study area was mainly derived from parent materials, and rarely come from human activities. The average soil Mn content in liver cancer's high incidence area was 577.65 mg x kg(-1), being significantly lower than that of liver cancer's low incidence area (718.04 mg x kg(-1)) and whole country (710 mg x kg(-1)). The Mn forms in high incidence area were mainly of residual Mn and Fe-Mn oxide, and less of water soluble Mn and exchangeable Mn, with the sum of the latter two's distribution coefficients being not higher than 4%. In low incidence area, the distribution pattern of soil Mn forms was similar to that in high incidence area, but the absolute contents of the Mn forms were significantly higher. Soil total Mn and soil pH had significant effects on soil Mn forms. There existed significant positive correlations between soil total Mn and the Mn forms of Fe-Mn bound, humic acid bound, carbonate bound, and residual, and negative correlations between soil pH and soil water soluble and organic bound Mn forms. Among the test five kinds of vegetables, Youmai lettuce and Chinese cabbage in liver cancer' s high incidence area had a significantly lower Mn content than in low incidence area, while the other three had less difference. The Mn enrichment in test vegetables was positively correlated with to the content of soil available Mn (sum of water soluble Mn and exchangeable Mn), but had no correlations with the contents of soil total Mn and other Mn forms.

Electronic structures of superionic conductor Li3N

NASA Astrophysics Data System (ADS)

Aoki, Masaru; Ode, Yoshiyuki; Tsumuraya, Kazuo

2011-03-01

Lithium nitride is a superionic conductor with high Li conductivity. The compound has been studied extensively because of its potential utility as electrolyte in solid-state batteries. Though the mobility of the cations within the crystalline solid is high comparable to that of molten salts, the mechanism of the high mobility of the cations remains unsolved. To clarify the origin of the mobility we investigate the electronic states of the Li cations in the Li 3 N crystal with the first principles electronic structure analysis, focusing a correlation between the cations and the ionicities of the constituent atoms. We have found the existence of the covalent bonding between the Li atoms in the Li 3 N crystal in spite of the ionized states of the constituent atoms.

Ultra-High Density Holographic Memory Module with Solid-State Architecture

NASA Technical Reports Server (NTRS)

Markov, Vladimir B.

2000-01-01

NASA's terrestrial. space, and deep-space missions require technology that allows storing. retrieving, and processing a large volume of information. Holographic memory offers high-density data storage with parallel access and high throughput. Several methods exist for data multiplexing based on the fundamental principles of volume hologram selectivity. We recently demonstrated that a spatial (amplitude-phase) encoding of the reference wave (SERW) looks promising as a way to increase the storage density. The SERW hologram offers a method other than traditional methods of selectivity, such as spatial de-correlation between recorded and reconstruction fields, In this report we present the experimental results of the SERW-hologram memory module with solid-state architecture, which is of particular interest for space operations.

VizieR Online Data Catalog: Spectroscopic analysis of 348 red giants (Zielinski+, 2012)

NASA Astrophysics Data System (ADS)

Zielinski, P.; Niedzielski, A.; Wolszczan, A.; Adamow, M.; Nowak, G.

2012-10-01

The atmospheric parameters were derived using a strictly spectroscopic method based on the LTE analysis of equivalent widths of FeI and FeII lines. With existing photometric data and the Hipparcos parallaxes, we estimated stellar masses and ages via evolutionary tracks fitting. The stellar radii were calculated from either estimated masses and the spectroscopic logg or from the spectroscopic Teff and estimated luminosities. The absolute radial velocities were obtained by cross-correlating spectra with a numerical template. Our high-quality, high-resolution optical spectra have been collected since 2004 with the Hobby-Eberly Telescope (HET), located in the McDonald Observatory. The telescope was equipped with the High Resolution Spectrograph (HRS; R~60000 resolution). (2 data files).

Assessment of benthic flux of dissolved organic carbon in wetland and estuarine sediments using the eddy-correlation technique

NASA Astrophysics Data System (ADS)

Swett, M. P.; Amirbahman, A.; Boss, E.

2009-12-01

Wetland and estuarine sediments release significant amounts of dissolved organic carbon (DOC) due to high levels of microbial activity, particularly sulfate reduction. Changes in climate and hydrologic conditions have a potential to alter DOC release from these systems as well. This is a concern, as high levels of DOC can lead to mobilization of toxic metals and organics in natural waters. In addition, source waters high in DOC produce undesirable disinfection byproducts in water treatment. Various in situ methods, such as peepers and sediment core centrifugation, exist to quantify vertical benthic fluxes of DOC and other dissolved species from the sediment-water interface (SWI). These techniques, however, are intrusive and involve disturbance of the sediment environment. Eddy-correlation allows for real-time, non-intrusive, in situ flux measurement of important analytes, such as O2 and DOC. An Acoustic Doppler Velocimeter (ADV) is used to obtain three-dimensional fluid velocity measurements. The eddy-correlation technique employs the mathematical separation of fluid velocity into mean velocity and fluctuating velocity components, with the latter representing turbulent eddy velocity. DOC concentrations are measured using a colored dissolved organic matter (CDOM) fluorometer, and instantaneous vertical flux is determined from the correlated data. This study assesses DOC flux at three project sites: a beaver pond in the Lower Penobscot Watershed, Maine; a mudflat in Penobscot River, Maine; and a mudflat in Great Bay, New Hampshire. Eddy flux values are compared with results obtained using peepers and centrifugation, as well as vertical profiling.

The H-Impairment Index (HII): a standardized assessment of alcohol-induced impairment in the Emergency Department.

PubMed

Hack, Jason B; Goldlust, Eric J; Gibbs, Frantz; Zink, Brian

2014-03-01

Emergency Departments (EDs) care for thousands of alcohol-intoxicated patients annually. No clinically relevant bedside measures currently exist to describe degree of impairment. To assess a group of bedside tests ("Hack's Impairment Index [HII] score") that applies a numerical value to the degree of alcohol-induced impairment in ED patients. A six-month retrospective review of HII score data was performed in a convenience sample of 293 intoxicated ED patients. Patients were scored 0-4 on five tasks, divided by the maximum score (20 if all tasks completed), every 2 hours; and classified by the number of visits: Low-frequency (1 visit); Medium-frequency (2 visits); High-frequency (≥3 visits). Correlations were assessed between HII score, healthcare provider judgment of intoxication, and measured alcohol levels. Study patients had 513 visits; 236 were low-frequency, 26 middle-frequency and 31 high-frequency. Clinical assessment and HII score were strongly correlated (Spearman's rho = 0.82, p < 0.001); clinical assessment and alcohol level less strongly so (rho = 0.49, p < 0.001). Among low-frequency patients, HII score and alcohol level were weakly correlated (r = 0.324, p < 0.001), with no such correlation among high-frequency visitors (r = -0.04, p = 0.89). The mean decline between serial HII scores was 0.126 (95% CI: 0.098-0.154). This pilot study shows the HII score can be performed at the bedside of alcohol-intoxicated patients. The HII declines in a reasonably predictable manner over time; and applies a quantitative, objective assessment of alcohol impairment.

Design and validation of an automated hydrostatic weighing system.

PubMed

McClenaghan, B A; Rocchio, L

1986-08-01

The purpose of this study was to design and evaluate the validity of an automated technique to assess body density using a computerized hydrostatic weighing system. An existing hydrostatic tank was modified and interfaced with a microcomputer equipped with an analog-to-digital converter. Software was designed to input variables, control the collection of data, calculate selected measurements, and provide a summary of the results of each session. Validity of the data obtained utilizing the automated hydrostatic weighing system was estimated by: evaluating the reliability of the transducer/computer interface to measure objects of known underwater weight; comparing the data against a criterion measure; and determining inter-session subject reliability. Values obtained from the automated system were found to be highly correlated with known underwater weights (r = 0.99, SEE = 0.0060 kg). Data concurrently obtained utilizing the automated system and a manual chart recorder were also found to be highly correlated (r = 0.99, SEE = 0.0606 kg). Inter-session subject reliability was determined utilizing data collected on subjects (N = 16) tested on two occasions approximately 24 h apart. Correlations revealed high relationships between measures of underwater weight (r = 0.99, SEE = 0.1399 kg) and body density (r = 0.98, SEE = 0.00244 g X cm-1). Results indicate that a computerized hydrostatic weighing system is a valid and reliable method for determining underwater weight.

Atmospheric response to Saharan dust deduced from ECMWF reanalysis increments

NASA Astrophysics Data System (ADS)

Kishcha, P.; Alpert, P.; Barkan, J.; Kirchner, I.; Machenhauer, B.

2003-04-01

This study focuses on the atmospheric temperature response to dust deduced from a new source of data - the European Reanalysis (ERA) increments. These increments are the systematic errors of global climate models, generated in reanalysis procedure. The model errors result not only from the lack of desert dust but also from a complex combination of many kinds of model errors. Over the Sahara desert the dust radiative effect is believed to be a predominant model defect which should significantly affect the increments. This dust effect was examined by considering correlation between the increments and remotely-sensed dust. Comparisons were made between April temporal variations of the ERA analysis increments and the variations of the Total Ozone Mapping Spectrometer aerosol index (AI) between 1979 and 1993. The distinctive structure was identified in the distribution of correlation composed of three nested areas with high positive correlation (> 0.5), low correlation, and high negative correlation (<-0.5). The innermost positive correlation area (PCA) is a large area near the center of the Sahara desert. For some local maxima inside this area the correlation even exceeds 0.8. The outermost negative correlation area (NCA) is not uniform. It consists of some areas over the eastern and western parts of North Africa with a relatively small amount of dust. Inside those areas both positive and negative high correlations exist at pressure levels ranging from 850 to 700 hPa, with the peak values near 775 hPa. Dust-forced heating (cooling) inside the PCA (NCA) is accompanied by changes in the static stability of the atmosphere above the dust layer. The reanalysis data of the European Center for Medium Range Weather Forecast(ECMWF) suggests that the PCA (NCA) corresponds mainly to anticyclonic (cyclonic) flow, negative (positive) vorticity, and downward (upward) airflow. These facts indicate an interaction between dust-forced heating /cooling and atmospheric circulation. The April correlation results are supported by the analysis of vertical distribution of dust concentration, derived from the 24-hour dust prediction system at Tel Aviv University (website: http://earth.nasa.proj.ac.il/dust/current/). For other months the analysis is more complicated because of the essential increasing of humidity along with the northward progress of the ITCZ and the significant impact on the increments.

Lack of Day/Night variation in fibroblast growth factor 21 levels in young healthy men.

PubMed

Foo, J-P; Aronis, K N; Chamberland, J P; Mantzoros, C S

2015-06-01

Fibroblast growth factor (FGF) 21 is an endocrine factor with an emerging role as a metabolic regulator. We previously reported the presence of a significant day/night variation of FGF-21 in energy-replete, healthy female subjects. However the day/night patterns of secretion in male subjects remain to be fully elucidated. To elucidate day/night pattern of FGF-21 levels in male subjects in the energy-replete state, its relationship to FFA and to investigate whether a sexual dimorphism exists in FGF-21 physiology. Eight healthy lean male subjects were studied for up to 5 days while on an isocaloric diet. Blood samples were obtained for measurement of FGF-21 and free fatty acids (FFA) hourly from 0800 AM on day 4 till 0800AM on day 5. FGF-21 did not exhibit any statistically significant day/night variation pattern of circulating FGF-21 levels during the isocaloric fed state in male subjects. FGF-21 levels in male subjects are closely cross-correlated with FFA levels, similar to female subjects. A sexual dimorphism exists in FGF-21 physiology; that as opposed to female subjects, no significant day/night variation exists in FGF-21 rhythm in male subjects in the energy-replete state. Circulating pattern of FGF-21, similar to the female subjects, was highly cross-correlated to the FFA levels in the male subjects, signifying that the sexual dimorphism in FGF-21 physiology may be related to the differing lipid metabolism in both the genders.

A phenotypic structure and neural correlates of compulsive behaviors in adolescents.

PubMed

Montigny, Chantale; Castellanos-Ryan, Natalie; Whelan, Robert; Banaschewski, Tobias; Barker, Gareth J; Büchel, Christian; Gallinat, Jürgen; Flor, Herta; Mann, Karl; Paillère-Martinot, Marie-Laure; Nees, Frauke; Lathrop, Mark; Loth, Eva; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Schumann, Gunter; Smolka, Michael N; Struve, Maren; Robbins, Trevor W; Garavan, Hugh; Conrod, Patricia J

2013-01-01

A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD), Eating Disorders (ED), substance abuse (SA) and binge-drinking (BD). The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates. A community-sample of adolescents (N=1938; mean age 14.5 years), and their parents were recruited via high-schools in 8 European study sites. Data on adolescents' psychiatric symptoms, DSM diagnoses (DAWBA) and substance use behaviors (AUDIT and ESPAD) were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI), and Voxel-Based Morphometry (VBM) analysis. Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p ≤ 0.001), conscientiousness (r=0.171; p ≤ 0.001), and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p ≤ 0.001), novelty-seeking (r=0.451; p ≤ 0.001), and negatively with gray matter volume in the left inferior and middle frontal gyri. Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum.

Associations Between Arterial Oxygen Saturation, Body Size and Limb Measurements Among High-Altitude Andean Children

PubMed Central

Pomeroy, Emma; Stock, Jay T; Stanojevic, Sanja; Miranda, J Jaime; Cole, Tim J; Wells, Jonathan CK

2013-01-01

Objectives The relative influences of hypoxia and other environmental stressors on growth at altitude remain unclear. Previous work demonstrated an association between peripheral arterial oxygen saturation (SpO2) and anthropometry (especially tibia length) among Tibetan and Han children at altitude. We investigated whether similar associations exist among Andeans, and the patterning of associations between SpO2 and anthropometry. Methods Stature, head-trunk height, total upper and lower limb lengths, zeugopod (ulna and tibia) and autopod (hand and foot) lengths were measured in Peruvian children (0.5–14 years) living at >3000 m altitude. SpO2 was measured by pulse oximetry. Anthropometry was converted to internal z scores. Correlation and multiple regression were used to examine associations between anthropometry z scores and SpO2, altitude, or SpO2 adjusted for altitude since altitude is a major determinant of variation in SpO2. Results SpO2 and altitude show weak, significant correlations with zeugopod length z scores and still weaker significant correlations with total upper and lower limb length z scores. Correlations with z scores for stature, head-trunk height, or autopod lengths are not significant. Adjusted for altitude, there is no significant association between anthropometry and SpO2. Conclusions Associations between SpO2 or altitude and total limb and zeugopod length z scores exist among Andean children. However, the relationships are relatively weak, and while the relationship between anthropometry and altitude may be partly mediated by SpO2, other factors that covary with altitude (e.g., socioeconomic status, health) are likely to influence anthropometry. The results support suggestions that zeugopod lengths are particularly sensitive to environmental stressors. Am. J. Hum. Biol., 25:629–636, 2013. © 2013 Wiley Periodicals, Inc. PMID:23904412

[Distribution of 137Cs and relative influencing factors on typical karst sloping land].

PubMed

Zhang, Xiao-Nan; Wang, Ke-Lin; Zhang, Wei; Chen, Hong-Song; He, Xun-Yang; Zhang, Xin-Bao

2009-11-01

Based on the field survey and the analysis of a large number of soil samples, the distribution of 137 Cs and its influencing factors were studied using 137 Cs tracer technology on typical karst sloping land. The results indicate that the distribution of 137 Cs in soil profile in karst areas show the similar characteristics as that in non-karst areas, fitted an exponential pattern in forest soils and a uniform pattern in cultivated soils. In the sinkhole points in karst areas, 137 Cs exists in deep soil layers and its specific activity vary from 1.7 to 3.3 Bq/kg in soil layers above 45cm, suggesting the existing soil around karst sinkhole is mainly formed by the accumulation of erosion materials. The 137 Cs specific activity in the soil from two rock cracks are 16.8 Bq/kg and 37.6 Bq/kg respectively, which are much higher than that in the soil around the rock, this phenomenon indicates that bare rock is an important influencing factor for 137 Cs spatial movement. With the increment of altitude, the 137 Cs area activity exhibits an irregular fluctuation and evident spatial heterogeneity. On the forest land, the 137 Cs area activities which range from 299.4 to 1 592.6 Bq/m2 are highly positively correlated with the slope gradient and positively correlated with the altitude; while on the cultivated land, the 137 Cs area activities which range from 115.8 to 1478.6 Bq/m2 are negatively correlated with the slope gradient but negatively correlated with the altitude. Topography, geomorphology and human disturbance intensity are the key factors influencing 137 Cs spatial distribution.

A Phenotypic Structure and Neural Correlates of Compulsive Behaviors in Adolescents

PubMed Central

Montigny, Chantale; Castellanos-Ryan, Natalie; Whelan, Robert; Banaschewski, Tobias; Barker, Gareth J.; Büchel, Christian; Gallinat, Jürgen; Flor, Herta; Mann, Karl; Paillère-Martinot, Marie-Laure; Nees, Frauke; Lathrop, Mark; Loth, Eva; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Schumann, Gunter; Smolka, Michael N.; Struve, Maren; Robbins, Trevor W.; Garavan, Hugh; Conrod, Patricia J.

2013-01-01

Background A compulsivity spectrum has been hypothesized to exist across Obsessive-Compulsive disorder (OCD), Eating Disorders (ED), substance abuse (SA) and binge-drinking (BD). The objective was to examine the validity of this compulsivity spectrum, and differentiate it from an externalizing behaviors dimension, but also to look at hypothesized personality and neural correlates. Method A community-sample of adolescents (N=1938; mean age 14.5 years), and their parents were recruited via high-schools in 8 European study sites. Data on adolescents’ psychiatric symptoms, DSM diagnoses (DAWBA) and substance use behaviors (AUDIT and ESPAD) were collected through adolescent- and parent-reported questionnaires and interviews. The phenotypic structure of compulsive behaviors was then tested using structural equation modeling. The model was validated using personality variables (NEO-FFI and TCI), and Voxel-Based Morphometry (VBM) analysis. Results Compulsivity symptoms best fit a higher-order two factor model, with ED and OCD loading onto a compulsivity factor, and BD and SA loading onto an externalizing factor, composed also of ADHD and conduct disorder symptoms. The compulsivity construct correlated with neuroticism (r=0.638; p≤0.001), conscientiousness (r=0.171; p≤0.001), and brain gray matter volume in left and right orbitofrontal cortex, right ventral striatum and right dorsolateral prefrontal cortex. The externalizing factor correlated with extraversion (r=0.201; p≤0.001), novelty-seeking (r=0.451; p≤0.001), and negatively with gray matter volume in the left inferior and middle frontal gyri. Conclusions Results suggest that a compulsivity spectrum exists in an adolescent, preclinical sample and accounts for variance in both OCD and ED, but not substance-related behaviors, and can be differentiated from an externalizing spectrum. PMID:24244633

Response of ammonium removal to growth and transpiration of Juncus effusus during the treatment of artificial sewage in laboratory-scale wetlands.

PubMed

Wiessner, A; Kappelmeyer, U; Kaestner, M; Schultze-Nobre, L; Kuschk, P

2013-09-01

The correlation between nitrogen removal and the role of the plants in the rhizosphere of constructed wetlands are the subject of continuous discussion, but knowledge is still insufficient. Since the influence of plant growth and physiological activity on ammonium removal has not been well characterized in constructed wetlands so far, this aspect is investigated in more detail in model wetlands under defined laboratory conditions using Juncus effusus for treating an artificial sewage. Growth and physiological activity, such as plant transpiration, have been found to correlate with both the efficiency of ammonium removal within the rhizosphere of J. effusus and the methane formation. The uptake of ammonium by growing plant stocks is within in a range of 45.5%, but under conditions of plant growth stagnation, a further nearly complete removal of the ammonium load points to the likely existence of additional nitrogen removal processes. In this way, a linear correlation between the ammonium concentration inside the rhizosphere and the transpiration of the plant stocks implies that an influence of plant physiological activity on the efficiency of N-removal exists. Furthermore, a linear correlation between methane concentration and plant transpiration has been estimated. The findings indicate a fast response of redox processes to plant activities. Accordingly, not only the influence of plant transpiration activity on the plant-internal convective gas transport, the radial oxygen loss by the plant roots and the efficiency of nitrification within the rhizosphere, but also the nitrogen gas released by phytovolatilization are discussed. The results achieved by using an unplanted control system are different in principle and characterized by a low efficiency of ammonium removal and a high methane enrichment of up to a maximum of 72.7% saturation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biomineralisation by earthworms - an investigation into the stability and distribution of amorphous calcium carbonate.

PubMed

Hodson, Mark E; Benning, Liane G; Demarchi, Bea; Penkman, Kirsty E H; Rodriguez-Blanco, Juan D; Schofield, Paul F; Versteegh, Emma A A

Many biominerals form from amorphous calcium carbonate (ACC), but this phase is highly unstable when synthesised in its pure form inorganically. Several species of earthworm secrete calcium carbonate granules which contain highly stable ACC. We analysed the milky fluid from which granules form and solid granules for amino acid (by liquid chromatography) and functional group (by Fourier transform infrared (FTIR) spectroscopy) compositions. Granule elemental composition was determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and electron microprobe analysis (EMPA). Mass of ACC present in solid granules was quantified using FTIR and compared to granule elemental and amino acid compositions. Bulk analysis of granules was of powdered bulk material. Spatially resolved analysis was of thin sections of granules using synchrotron-based μ-FTIR and EMPA electron microprobe analysis. The milky fluid from which granules form is amino acid-rich (≤ 136 ± 3 nmol mg -1 (n = 3; ± std dev) per individual amino acid); the CaCO 3 phase present is ACC. Even four years after production, granules contain ACC. No correlation exists between mass of ACC present and granule elemental composition. Granule amino acid concentrations correlate well with ACC content (r ≥ 0.7, p ≤ 0.05) consistent with a role for amino acids (or the proteins they make up) in ACC stabilisation. Intra-granule variation in ACC (RSD = 16%) and amino acid concentration (RSD = 22-35%) was high for granules produced by the same earthworm. Maps of ACC distribution produced using synchrotron-based μ-FTIR mapping of granule thin sections and the relative intensity of the ν 2 : ν 4 peak ratio, cluster analysis and component regression using ACC and calcite standards showed similar spatial distributions of likely ACC-rich and calcite-rich areas. We could not identify organic peaks in the μ-FTIR spectra and thus could not determine whether ACC-rich domains also had relatively high amino acid concentrations. No correlation exists between ACC distribution and elemental concentrations determined by EMPA. ACC present in earthworm CaCO 3 granules is highly stable. Our results suggest a role for amino acids (or proteins) in this stability. We see no evidence for stabilisation of ACC by incorporation of inorganic components. Graphical abstractSynchrotron-based μ-FTIR mapping was used to determine the spatial distribution of amorphous calcium carbonate in earthworm-produced CaCO 3 granules.

Detection of changes in semi-natural grasslands by cross correlation analysis with WorldView-2 images and new Landsat 8 data.

PubMed

Tarantino, Cristina; Adamo, Maria; Lucas, Richard; Blonda, Palma

2016-03-15

Focusing on a Mediterranean Natura 2000 site in Italy, the effectiveness of the cross correlation analysis (CCA) technique for quantifying change in the area of semi-natural grasslands at different spatial resolutions (grain) was evaluated. In a fine scale analysis (2 m), inputs to the CCA were a) a semi-natural grasslands layer extracted from an existing validated land cover/land use (LC/LU) map (1:5000, time T 1 ) and b) a more recent single date very high resolution (VHR) WorldView-2 image (time T 2 ), with T 2  > T 1 . The changes identified through the CCA were compared against those detected by applying a traditional post-classification comparison (PCC) technique to the same reference T 1 map and an updated T 2 map obtained by a knowledge driven classification of four multi-seasonal Worldview-2 input images. Specific changes observed were those associated with agricultural intensification and fires. The study concluded that prior knowledge (spectral class signatures, awareness of local agricultural practices and pressures) was needed for the selection of the most appropriate image (in terms of seasonality) to be acquired at T 2 . CCA was also applied to the comparison of the existing T 1 map with recent high resolution (HR) Landsat 8 OLS images. The areas of change detected at VHR and HR were broadly similar with larger error values in HR change images.

Estimating psycho-physiological state of a human by speech analysis

NASA Astrophysics Data System (ADS)

Ronzhin, A. L.

2005-05-01

Adverse effects of intoxication, fatigue and boredom could degrade performance of highly trained operators of complex technical systems with potentially catastrophic consequences. Existing physiological fitness for duty tests are time consuming, costly, invasive, and highly unpopular. Known non-physiological tests constitute a secondary task and interfere with the busy workload of the tested operator. Various attempts to assess the current status of the operator by processing of "normal operational data" often lead to excessive amount of computations, poorly justified metrics, and ambiguity of results. At the same time, speech analysis presents a natural, non-invasive approach based upon well-established efficient data processing. In addition, it supports both behavioral and physiological biometric. This paper presents an approach facilitating robust speech analysis/understanding process in spite of natural speech variability and background noise. Automatic speech recognition is suggested as a technique for the detection of changes in the psycho-physiological state of a human that typically manifest themselves by changes of characteristics of voice tract and semantic-syntactic connectivity of conversation. Preliminary tests have confirmed that the statistically significant correlation between the error rate of automatic speech recognition and the extent of alcohol intoxication does exist. In addition, the obtained data allowed exploring some interesting correlations and establishing some quantitative models. It is proposed to utilize this approach as a part of fitness for duty test and compare its efficiency with analyses of iris, face geometry, thermography and other popular non-invasive biometric techniques.

A 911 year chronology from earlywood vessels of European oak in NE-Germany and its use for climate reconstructions

NASA Astrophysics Data System (ADS)

Heinrich, Ingo; Balanzategui, Daniel; Heußner, Karl-Uwe; Pritzkow, Carola; Giese, Laura; Graaf, Johannes; Lindemann, Josephine; Schirmer, Thomas; Dorado Liñán, Isabel; Wazny, Tomasz; Scharnweber, Tobias; Van der Maaten, Ernst; Helle, Gerd; Blume, Theresa; Pohlmann, Silvio

2016-04-01

Tree-ring based temperature reconstructions form a substantial part of the international proxy data base used to examine and model global climate variations of the last Millennium. However, most tree-ring based reconstructions are derived from study sites in the high latitudes or high altitudes paying little attention to the temperate lowlands worldwide. Thus, a large gap in the geographical coverage of climate reconstructions, in particular temperature reconstructions, from temperate low elevation sites in central Europe still exists. This motivated us to concentrate our efforts on the European oak (Quercus robur) in Northeastern Germany, combining core samples from living trees with archaeological wood. We developed a new wood anatomical chronology focusing on the earlywood vessels of Q. robur for the period 1100 to 2011. As far as we know it is by far the longest chronology based on wood anatomical parameters. First climate growth analyses demonstrated that earlywood vessel parameters, especially average vessel area, contained climate signals which were different and more significant than those found in tree-ring widths. The strongest correlation was found with winter temperatures. This relationship was then used for a reconstruction for the period 1100 to 2011. By using only raw values, low-frequency signals could be sustained. This new reconstruction was compared with already existing temperature reconstructions and spatial field correlations were calculated. Results will be presented and discussed at EGU for the first time.

a High Precision dem Extraction Method Based on Insar Data

NASA Astrophysics Data System (ADS)

Wang, Xinshuang; Liu, Lingling; Shi, Xiaoliang; Huang, Xitao; Geng, Wei

2018-04-01

In the 13th Five-Year Plan for Geoinformatics Business, it is proposed that the new InSAR technology should be applied to surveying and mapping production, which will become the innovation driving force of geoinformatics industry. This paper will study closely around the new outline of surveying and mapping and then achieve the TerraSAR/TanDEM data of Bin County in Shaanxi Province in X band. The studying steps are as follows; Firstly, the baseline is estimated from the orbital data; Secondly, the interferometric pairs of SAR image are accurately registered; Thirdly, the interferogram is generated; Fourth, the interferometric correlation information is estimated and the flat-earth phase is removed. In order to solve the phase noise and the discontinuity phase existing in the interferometric image of phase, a GAMMA adaptive filtering method is adopted. Aiming at the "hole" problem of missing data in low coherent area, the interpolation method of low coherent area mask is used to assist the phase unwrapping. Then, the accuracy of the interferometric baseline is estimated from the ground control points. Finally, 1 : 50000 DEM is generated, and the existing DEM data is used to verify the accuracy through statistical analysis. The research results show that the improved InSAR data processing method in this paper can obtain the high-precision DEM of the study area, exactly the same with the topography of reference DEM. The R2 can reach to 0.9648, showing a strong positive correlation.

Smoking intensity among male factory workers in Kunming, China.

PubMed

Cheng, Kai-Wen; Tsoh, Janice Y; Cui, Wenlong; Li, Xiaoliang; Kohrman, Matthew

2015-03-01

This study investigated the intensity of cigarette consumption and its correlates in China among urban male factory workers, a cohort especially vulnerable to tobacco exposure, one that appears to have benefitted little from recent public health efforts to reduce smoking rates. Data were collected from men working in factories of Kunming city, Yunnan, China, who are current daily smokers (N = 490). A multinomial logistic regression was conducted to examine the factors in association with smoking intensity in light, moderate, and heavy levels. Light smoking correlated with social smoking, smoking the first cigarette later in the day, self-reported health condition, and quit intention. Heavy smoking was associated with purchase of lower priced cigarettes, difficulty refraining from smoking, and prehypertensive blood pressure. Even in regions where smoking is highly prevalent, even among cohorts who smoke heavily, variation exists in how cigarettes are consumed. Analyses of this consumption, with special consideration given to smoking intensity and its correlates, can help guide tobacco-control strategists in developing more effective interventions. © 2013 APJPH.

Business Metrics for High-Performance Homes: A Colorado Springs Case Study

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

Beach, R.; Jones, A.

This report explores the correlation between energy efficiency and the business success of home builders by examining a data set of builders and homes in the Colorado Springs, Colorado, market between 2006 and 2014. During this time, the Great Recession of 2007 to 2009 occurred, and new-home sales plummeted both nationally and in Colorado Springs. What is evident from an analysis of builders and homes in Colorado Springs is that builders who had Home Energy Rating System (HERS) ratings performed on some or all of their homes during the Recession remained in business during this challenging economic period. Many buildersmore » who did not have HERS ratings performed on their homes at that time went out of business or left the area. From the analysis presented in this report, it is evident that a correlation exists between energy efficiency and the business success of home builders, although the reasons for this correlation remain largely anecdotal and not yet clearly understood.« less

School-age children's fears, anxiety, and human figure drawings.

PubMed

Carroll, M K; Ryan-Wenger, N A

1999-01-01

The purpose of this study was to identify the fears of school-age children and determine the relationship between fear and anxiety. A descriptive, correlational, secondary analysis study was conducted using a convenience sample of 90 children between the ages of 8 and 12 years. Each child was instructed to complete the Revised Children's Anxiety Scale and then answer questions from a structured interview. On completion, each child was instructed to draw a human figure drawing. Frequency charts and correlational statistics were used to analyze the data. Findings indicated that the most significant fears of the boys were in the categories of animals, safety, school, and supernatural phenomena, whereas girls were more fearful of natural phenomena. High correlations existed between anxiety scores and the number of fears and emotional indicators on human figure drawings. Because human figure drawings are reliable tools for assessing anxiety and fears in children, practitioners should incorporate these drawings as part of their routine assessments of fearful children.

Correlates and Racial/Ethnic Differences in Bareback Sex Among Men Who Have Sex with Men with Unknown or Negative HIV Serostatus.

PubMed

Vosvick, Mark; Fritz, Sarah; Henry, Doug; Prybutok, Victor; Sheu, Shane; Poe, Jonathon

2016-12-01

Men who have sex with men (MSM), particularly racial/ethnic minority MSM, are disproportionately affected by HIV in the United States and Texas. Bareback sex or condomless anal intercourse (CAI) can be a high HIV risk behavior. Despite this, a majority of MSM continues to engage in barebacking. Research suggests racial/ethnic differences in barebacking exist; however, these conclusions remain unclear due to insufficient sample sizes to compare racial/ethnic groups. Our cross-sectional correlational design explores barebacking correlates (substance use during sex, safe sex fatigue, and optimistic HIV treatment beliefs) within and between racial/ethnic groups among 366 MSM. Regression models are significant for Latino and African-American MSM alone and for all MSM combined, though not significant for European-American and Other Race/Ethnicity MSM alone. Our findings suggest motivations and behaviors underlying barebacking among MSM vary by racial/ethnic membership with clinical implications for informing culturally sensitive HIV interventions and prevention programs for target racial/ethnic groups.

Influence of weather and climate on subjective symptom intensity in atopic eczema

NASA Astrophysics Data System (ADS)

Vocks, E.; Busch, R.; Fröhlich, C.; Borelli, S.; Mayer, H.; Ring, J.

The frequent clinical observation that the course of atopic eczema, a skin disease involving a disturbed cutaneous barrier function, is influenced by climate and weather motivated us to analyse these relationships biometrically. In the Swiss high-mountain area of Davos the intensity of itching experienced by patients with atopic eczema was evaluated and compared to 15 single meteorological variables recorded daily during an entire 7-year observation period. By means of univariate analyses and multiple regressions, itch intensity was found to be correlated with some meteorological variables. A clear-cut inverse correlation exists with air temperature (coefficient of correlation: -0.235, P<0.001), but the effects of water vapour pressure, air pressure and hours of sunshine are less pronounced. The results show that itching in atopic eczema is significantly dependent on meteorological conditions. The data suggest that, in patients with atopic eczema, a certain range of thermo-hygric atmospheric conditions with a balance of heat and water loss on the skin surface is essential for the skin to feel comfortable.

Measurements and Correlations of cis-1,3,3,3-Tetrafluoroprop-1-ene (R1234ze(Z)) Saturation Pressure

NASA Astrophysics Data System (ADS)

Fedele, Laura; Di Nicola, Giovanni; Brown, J. Steven; Bobbo, Sergio; Zilio, Claudio

2014-01-01

cis-1,3,3,3-Tetrafluoroprop-1-ene (R1234ze(Z)) is being investigated as a working fluid possessing a low global warming potential (GWP) for high-temperature heat pumping applications, organic Rankine cycles, and air-conditioning and refrigeration applications, and as a potential solvent, propellant, and foam blowing agent. Its GWP is less than one. The open literature contains a total of 79 vapor-pressure data from three sources and the critical state properties from a single source. The current paper provides 64 vapor-pressure data from two different laboratories over the temperature range from 238.13 K to 372.61 K. These data are regressed using Wagner and extended Antoine vapor-pressure correlations and then compared to the existing open literature data and correlations. The normal-boiling-point temperature and acentric factor for R1234ze(Z) are estimated to be 282.73 K and 0.3257, respectively.

Full-flow-regime storage-streamflow correlation patterns provide insights into hydrologic functioning over the continental US

NASA Astrophysics Data System (ADS)

Fang, Kuai; Shen, Chaopeng

2017-09-01

Interannual changes in low, median, and high regimes of streamflow have important implications for flood control, irrigation, and ecologic and human health. The Gravity Recovery and Climate Experiment (GRACE) satellites record global terrestrial water storage anomalies (TWSA), providing an opportunity to observe, interpret, and potentially utilize the complex relationships between storage and full-flow-regime streamflow. Here we show that utilizable storage-streamflow correlations exist throughout vastly different climates in the continental US (CONUS) across low- to high-flow regimes. A panoramic framework, the storage-streamflow correlation spectrum (SSCS), is proposed to examine macroscopic gradients in these relationships. SSCS helps form, corroborate or reject hypotheses about basin hydrologic behaviors. SSCS patterns vary greatly over CONUS with climate, land surface, and geologic conditions. Data mining analysis suggests that for catchments with hydrologic settings that favor storage over runoff, e.g., a large fraction of precipitation as snow, thick and highly-permeable permeable soil, SSCS values tend to be high. Based on our results, we form the hypotheses that groundwater flow dominates streamflows in Southeastern CONUS and Great Plains, while thin soils in a belt along the Appalachian Plateau impose alimit on water storage. SSCS also suggests shallow water table caused by high-bulk density soil and flat terrain induces rapid runoff in several regions. Our results highlight the importance of subsurface properties and groundwater flow in capturing flood and drought. We propose that SSCS can be used as a fundamental hydrologic signature to constrain models and to provide insights thatlead usto better understand hydrologic functioning.

Spatial-temporal consistency between gross primary productivity and solar-induced chlorophyll fluorescence of vegetation in China during 2007-2014

NASA Astrophysics Data System (ADS)

Ma, J.; Xiao, X.; Zhang, Y.; Chen, B.; Zhao, B.

2017-12-01

Great significance exists in accurately estimating spatial-temporal patterns of gross primary production (GPP) because of its important role in global carbon cycle. Satellite-based light use efficiency (LUE) models are regarded as an efficient tool in simulating spatially time-sires GPP. However, the estimation of the accuracy of GPP simulations from LUE at both spatial and temporal scales is still a challenging work. In this study, we simulated GPP of vegetation in China during 2007-2014 using a LUE model (Vegetation Photosynthesis Model, VPM) based on MODIS (moderate-resolution imaging spectroradiometer) images of 8-day temporal and 500-m spatial resolutions and NCEP (National Center for Environmental Prediction) climate data. Global Ozone Monitoring Instrument 2 (GOME-2) solar-induced chlorophyll fluorescence (SIF) data were used to compare with VPM simulated GPP (GPPVPM) temporally and spatially using linear correlation analysis. Significant positive linear correlations exist between monthly GPPVPM and SIF data over both single year (2010) and multiple years (2007-2014) in China. Annual GPPVPM is significantly positive correlated with SIF (R2>0.43) spatially for all years during 2007-2014 and all seasons in 2010 (R2>0.37). GPP dynamic trends is high spatial-temporal heterogeneous in China during 2007-2014. The results of this study indicate that GPPVPM is temporally and spatially in line with SIF data, and space-borne SIF data have great potential in validating and parameterizing GPP estimation of LUE-based models.

Study on environmental indices and heat tolerance tests in hair sheep.

PubMed

Seixas, L; de Melo, C B; Menezes, A M; Ramos, A F; Paludo, G R; Peripolli, V; Tanure, C B; Costa Junior, J B G; McManus, C

2017-06-01

The ability to predict the effects of climatic factors on animals and their adaptability is important for livestock production. The aim of the present study was to analyze whether existing indices are suitable for evaluating heat stress in Santa Ines and Morada Nova sheep, which are locally adapted hair sheep breeds from northeastern Brazil, and if the limits used to classify thermal stress are suitable for these breeds. Therefore, climatic, physiological, and physical parameters, as well as thermographic images, were collected in 26 sheep, 1 1/2 years old, from two genetic groups (Santa Ines 12 males and 4 females; Morada Nov. 7 males and 3 females) for 3 days in both morning (4:00 a.m.) and afternoon (2:00 p.m.) with six repetitions, totalizing 156 repetitions. Statistical analysis included correlations and broken-line regressions. Iberia and Benezra indices were the tolerance tests that best correlated with the assessed parameters. High correlations between environmental indices and rectal or skin surface temperatures was observed, which indicates that these indices can be used for Santa Ines and Morada Nova sheep raised in central Brazil. However, some indicative values of thermal discomfort are different from the existing classification. Therefore, in order to classify appropriately, the model used needs to be carefully studied, because these classifying values can vary according to the species and model. Further research is necessary to establish indicators of thermal stress for sheep breeds raised in the region.

The availability of filament ends modulates actin stochastic dynamics in live plant cells

PubMed Central

Li, Jiejie; Staiger, Benjamin H.; Henty-Ridilla, Jessica L.; Abu-Abied, Mohamad; Sadot, Einat; Blanchoin, Laurent; Staiger, Christopher J.

2014-01-01

A network of individual filaments that undergoes incessant remodeling through a process known as stochastic dynamics comprises the cortical actin cytoskeleton in plant epidermal cells. From images at high spatial and temporal resolution, it has been inferred that the regulation of filament barbed ends plays a central role in choreographing actin organization and turnover. How this occurs at a molecular level, whether different populations of ends exist in the array, and how individual filament behavior correlates with the overall architecture of the array are unknown. Here we develop an experimental system to modulate the levels of heterodimeric capping protein (CP) and examine the consequences for actin dynamics, architecture, and cell expansion. Significantly, we find that all phenotypes are the opposite for CP-overexpression (OX) cells compared with a previously characterized cp-knockdown line. Specifically, CP OX lines have fewer filament–filament annealing events, as well as reduced filament lengths and lifetimes. Further, cp-knockdown and OX lines demonstrate the existence of a subpopulation of filament ends sensitive to CP concentration. Finally, CP levels correlate with the biological process of axial cell expansion; for example, epidermal cells from hypocotyls with reduced CP are longer than wild-type cells, whereas CP OX lines have shorter cells. On the basis of these and other genetic studies in this model system, we hypothesize that filament length and lifetime positively correlate with the extent of axial cell expansion in dark-grown hypocotyls. PMID:24523291

Tobacco use, oral cancer screening, and oral disease burden in Indian women.

PubMed

Joseph, Immanuel; Rooban, Thavarajah; Ranganathan, Kannan

2017-01-01

India lacks data on national level adaptation of oral cancer screening measures and burden of oral diseases. We intend to address the issue through a secondary data analysis of existing data and reports. Data were acquired from the National Family Health Survey-4 (2015-2016). Of the 699,686 responses, representing 99% of India's women population living in all of India, the following data from the age group of 15-49 years were mined - any tobacco use, desire to quit tobacco use, and oral cavity screening for cancers. Data from Central Health Intelligence Bureau 2016 was used to identify population served by dentists in each state. The state-level data of the District Level Household and Facility Survey-4 (2012-2013) were mined for household population having symptoms of chronic illness including mouth/dental illness persisting for more than 1 month and had sought treatment. SPSS version 20; Descriptive statistics for values in proportions; Pearson's correlation test assessed between the various factors. Tobacco use in any form was highly prevalent among the North Eastern states, and there was also a lack of willingness to quit the habit. There was unequal distribution of dentists in different states. No significant statistical correlation was found between the proportions. There is disparity existing in treating seeking behavior of the general population as well as the need for dental treatment. The skewedness in dentists' distribution among the nation as compared with oral burden of diseases needs to be correlated before oral health policies are planned.

Full-field transient vibrometry of the human tympanic membrane by local phase correlation and high-speed holography

NASA Astrophysics Data System (ADS)

Dobrev, Ivo; Furlong, Cosme; Cheng, Jeffrey T.; Rosowski, John J.

2014-09-01

Understanding the human hearing process would be helped by quantification of the transient mechanical response of the human ear, including the human tympanic membrane (TM or eardrum). We propose a new hybrid high-speed holographic system (HHS) for acquisition and quantification of the full-field nanometer transient (i.e., >10 kHz) displacement of the human TM. We have optimized and implemented a 2+1 frame local correlation (LC) based phase sampling method in combination with a high-speed (i.e., >40 K fps) camera acquisition system. To our knowledge, there is currently no existing system that provides such capabilities for the study of the human TM. The LC sampling method has a displacement difference of <11 nm relative to measurements obtained by a four-phase step algorithm. Comparisons between our high-speed acquisition system and a laser Doppler vibrometer indicate differences of <10 μs. The high temporal (i.e., >40 kHz) and spatial (i.e., >100 k data points) resolution of our HHS enables parallel measurements of all points on the surface of the TM, which allows quantification of spatially dependent motion parameters, such as modal frequencies and acoustic delays. Such capabilities could allow inferring local material properties across the surface of the TM.

Ranking Causal Anomalies via Temporal and Dynamical Analysis on Vanishing Correlations.

PubMed

Cheng, Wei; Zhang, Kai; Chen, Haifeng; Jiang, Guofei; Chen, Zhengzhang; Wang, Wei

2016-08-01

Modern world has witnessed a dramatic increase in our ability to collect, transmit and distribute real-time monitoring and surveillance data from large-scale information systems and cyber-physical systems. Detecting system anomalies thus attracts significant amount of interest in many fields such as security, fault management, and industrial optimization. Recently, invariant network has shown to be a powerful way in characterizing complex system behaviours. In the invariant network, a node represents a system component and an edge indicates a stable, significant interaction between two components. Structures and evolutions of the invariance network, in particular the vanishing correlations, can shed important light on locating causal anomalies and performing diagnosis. However, existing approaches to detect causal anomalies with the invariant network often use the percentage of vanishing correlations to rank possible casual components, which have several limitations: 1) fault propagation in the network is ignored; 2) the root casual anomalies may not always be the nodes with a high-percentage of vanishing correlations; 3) temporal patterns of vanishing correlations are not exploited for robust detection. To address these limitations, in this paper we propose a network diffusion based framework to identify significant causal anomalies and rank them. Our approach can effectively model fault propagation over the entire invariant network, and can perform joint inference on both the structural, and the time-evolving broken invariance patterns. As a result, it can locate high-confidence anomalies that are truly responsible for the vanishing correlations, and can compensate for unstructured measurement noise in the system. Extensive experiments on synthetic datasets, bank information system datasets, and coal plant cyber-physical system datasets demonstrate the effectiveness of our approach.

Wavelet-based image compression using shuffling and bit plane correlation

NASA Astrophysics Data System (ADS)

Kim, Seungjong; Jeong, Jechang

2000-12-01

In this paper, we propose a wavelet-based image compression method using shuffling and bit plane correlation. The proposed method improves coding performance in two steps: (1) removing the sign bit plane by shuffling process on quantized coefficients, (2) choosing the arithmetic coding context according to maximum correlation direction. The experimental results are comparable or superior for some images with low correlation, to existing coders.

Two-phase flow correlations as applied to pumping well testing

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

Kabir, C.S.; Hasan, A.R.

1994-06-01

In a pumping-well buildup test, computation of bottom-hole pressure (BHP) and flow rate (BHF) requires the use of a two-phase flow correlation for estimating the gas void-fraction or holdup along the pipe length and shut-in time. Various correlations are available to perform this task. The purpose of this work is to review these two-phase correlations and to provide an objective evaluation. This analysis is necessitated by the fact that considerable differences in BHP and BHF may occur -- depending upon the correlation used -- in wells with long pumping liquid columns or those that have high gas/liquid ratio production. Consequently,more » a potential exists for obtaining different reservoir parameters from transient interpretation. Using laboratory data for two-phase flow in annular geometry, relative strengths of these correlations are explored. The authors' own data and those of others (a total of 114 points) are used in this comparative study. For static liquid columns, the correlations of Hasan-Kabir, Gilbert, and Podio et al. provide acceptable agreement with experimental data, exceptions being the Godbey-Dimon and Schmidt et al. correlations. In contrast, for the moving liquid column scenario, as in a buildup test, the Hasan-Kabir model provides the best agreement with the data set used in this work. A basis for smoothing the bubbly/slug transition boundary is given for the Hasan-Kabir method, together with a field example.« less

A novel coefficient for detecting and quantifying asymmetry of California electricity market based on asymmetric detrended cross-correlation analysis.

PubMed

Wang, Fang

2016-06-01

In order to detect and quantify asymmetry of two time series, a novel cross-correlation coefficient is proposed based on recent asymmetric detrended cross-correlation analysis (A-DXA), which we called A-DXA coefficient. The A-DXA coefficient, as an important extension of DXA coefficient ρDXA, contains two directional asymmetric cross-correlated indexes, describing upwards and downwards asymmetric cross-correlations, respectively. By using the information of directional covariance function of two time series and directional variance function of each series itself instead of power-law between the covariance function and time scale, the proposed A-DXA coefficient can well detect asymmetry between the two series no matter whether the cross-correlation is significant or not. By means of the proposed A-DXA coefficient conducted over the asymmetry for California electricity market, we found that the asymmetry between the prices and loads is not significant for daily average data in 1999 yr market (before electricity crisis) but extremely significant for those in 2000 yr market (during the crisis). To further uncover the difference of asymmetry between the years 1999 and 2000, a modified H statistic (MH) and ΔMH statistic are proposed. One of the present contributions is that the high MH values calculated for hourly data exist in majority months in 2000 market. Another important conclusion is that the cross-correlation with downwards dominates over the whole 1999 yr in contrast to the cross-correlation with upwards dominates over the 2000 yr.

Structural instability and phase co-existence driven non-Gaussian resistance fluctuations in metal nanowires at low temperatures.

PubMed

Bid, Aveek; Raychaudhuri, A K

2016-11-11

We report a detailed experimental study of the resistance fluctuations measured at low temperatures in high quality metal nanowires ranging in diameter from 15-200 nm. The wires exhibit co-existing face-centered-cubic and 4H hcp phases of varying degrees as determined from the x-ray diffraction data. We observe the appearance of a large non-Gaussian noise for nanowires of diameter smaller than 50 nm over a certain temperature range around ≈30 K. The diameter range ∼30 nm, where the noise has maxima coincides with the maximum volume fraction of the co-existing 4H hcp phase thus establishing a strong link between the fluctuation and the phase co-existence. The resistance fluctuation in the same temperature range also shows a deviation of [Formula: see text] behavior at low frequency with appearance of single frequency Lorentzian type contribution in the spectral power density. The fluctuations are thermally activated with an activation energy [Formula: see text] meV, which is of same order as the activation energy of creation of stacking fault in FCC metals that leads to the co-existing crystallographic phases. Combining the results of crystallographic studies of the nanowires and analysis of the resistance fluctuations we could establish the correlation between the appearance of the large resistance noise and the onset of phase co-existence in these nanowires.

Influence of lumbar lordosis restoration on thoracic curve and sagittal position in lumbar degenerative kyphosis patients.

PubMed

Jang, Jee-Soo; Lee, Sang-Ho; Min, Jun-Hong; Maeng, Dae Hyeon

2009-02-01

A retrospective study. To determine postsurgical correlations between thoracic and lumbar sagittal curves in lumbar degenerative kyphosis (LDK) and to determine predictability of spontaneous correction of thoracic curve and sacral angle after surgical restoration of lumbar lordosis and fusion. To our knowledge, there are only a limited number of articles about the relationship between thoracic and lumbar curve in sagittal thoracic compensated LDK. Retrospective review of 53 consecutive patients treated with combined anterior and posterior spinal arthrodesis. We included patients with sagittal thoracic compensated LDK caused by sagittal imbalance in this study. Total lumbar lordosis, thoracic kyphosis, sacral slope, and C7 plumb line were measured on the pre- and postoperative whole spine lateral views. Postoperative changes in thoracic kyphosis, sacral slope, and C7 plumb line according to the surgical lumbar lordosis restoration were measured and evaluated. The mean preoperative sagittal imbalance by plumb line was 78.3 mm (+/-76.5); this improved to 13.6 mm (+/-25) after surgery (P < 0.0001). Mean lumbar lordosis was 9.4 degrees (+/-19.2) before surgery and increased to 38.4 degrees (+/-13.1) at follow-up (P < 0.0001). Mean thoracic kyphosis was 1.1 degrees (+/-12.7) before surgery and increased to 17.6 degrees (+/-12.2) at follow-up (P < 0.0001). Significant preoperative correlations existed between kyphosis and lordosis (r = 0.772, P < 0.0001) and between lordosis and sacral slope (r = 0.785, P < 0.0001). Postoperative lumbar lordosis is correlated to thoracic kyphosis increase (r = 0.620, P < 0.0001). Postoperative lumbar lordosis is correlated to sacral slope increase (r = 0.722, P < 0.0001). Reciprocal relationship exists between lumbar lordosis and thoracic kyphosis in sagittal thoracic compensated LDK. Surgical restoration of lumbar lordosis for LDK brings about high level of statistical correlation to thoracic kyphosis improvement. At the same time, the reciprocal relationship is maintained.

Correlations among the parameters of the spherical model for eclipsing binaries

NASA Technical Reports Server (NTRS)

Sobieski, S.; White, J. E.

1971-01-01

Correlation coefficients were computed to investigate the parameters for describing the spherical model of an eclipsing binary system. Regions in parameter hyperspace were identified where strong correlations exist and, by implication, the solution determinacy is low. The results are presented in tabular form for a large number of system configurations.

Candida species isolation in peristomal skin in patients with abdominal stomas and correlation to clinical signs: a descriptive pilot study.

PubMed

Morales-Mendoza, Yamilett; Fernández-Martínez, Ramón; Fabián-Victoriano, Ma Rosy; Contreras-Ruiz, José; Vásquez-del-Mercado, Elsa; de Lourdes Suárez-Roa, Maria; Arenas-Guzman, Roberto

2014-11-01

The reported prevalence of candidiasis in peristomal skin varies greatly. Very few studies exist that correlate the clinical findings around the peristomal skin to the mycology. In this study, the authors report on Candida species prevalence, clinical correlation, and mycology.

Dynamic Functional Connectivity States Between the Dorsal and Ventral Sensorimotor Networks Revealed by Dynamic Conditional Correlation Analysis of Resting-State Functional Magnetic Resonance Imaging.

PubMed

Syed, Maleeha F; Lindquist, Martin A; Pillai, Jay J; Agarwal, Shruti; Gujar, Sachin K; Choe, Ann S; Caffo, Brian; Sair, Haris I

2017-12-01

Functional connectivity in resting-state functional magnetic resonance imaging (rs-fMRI) has received substantial attention since the initial findings of Biswal et al. Traditional network correlation metrics assume that the functional connectivity in the brain remains stationary over time. However, recent studies have shown that robust temporal fluctuations of functional connectivity among as well as within functional networks exist, challenging this assumption. In this study, these dynamic correlation differences were investigated between the dorsal and ventral sensorimotor networks by applying the dynamic conditional correlation model to rs-fMRI data of 20 healthy subjects. k-Means clustering was used to determine an optimal number of discrete connectivity states (k = 10) of the sensorimotor system across all subjects. Our analysis confirms the existence of differences in dynamic correlation between the dorsal and ventral networks, with highest connectivity found within the ventral motor network.

High order neural correlates of social behavior in the honeybee brain.

PubMed

Duer, Aron; Paffhausen, Benjamin H; Menzel, Randolf

2015-10-30

Honeybees are well established models of neural correlates of sensory function, learning and memory formation. Here we report a novel approach allowing to record high-order mushroom body-extrinsic interneurons in the brain of worker bees within a functional colony. New method The use of two 100 cm long twisted copper electrodes allowed recording of up to four units of mushroom body-extrinsic neurons simultaneously for up to 24h in animals moving freely between members of the colony. Every worker, including the recorded bee, hatched in the experimental environment. The group consisted of 200 animals in average. Animals explored different regions of the comb and interacted with other colony members. The activities of the units were not selective for locations on the comb, body directions with respect to gravity and olfactory signals on the comb, or different social interactions. However, combinations of these parameters defined neural activity in a unit-specific way. In addition, units recorded from the same animal co-varied according to unknown factors. Comparison with existing method(s): All electrophysiological studies with honey bees were performed so far on constrained animals outside their natural behavioral contexts. Yet no neuronal correlates were measured in a social context. Free mobility of recoded insects over a range of a quarter square meter allows addressing questions concerning neural correlates of social communication, planning of tasks within the colony and attention-like processes. The method makes it possible to study neural correlates of social behavior in a near-natural setting within the honeybee colony. Copyright © 2015 Elsevier B.V. All rights reserved.

Urinary angiotensinogen as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease patients.

PubMed

Xu, Z; Xu, B; Xu, C

2015-06-01

Urinary angiotensinogen (AGT) mainly derives from the AGT produced in proximal tubular cells. Evidence exists that supports the correlation between urinary AGT and circulating AGT. To investigate the role of urinary AGT as a potential biomarker of intrarenal renin-angiotensin system activity in Chinese chronic kidney disease (CKD) patients. ELISA-based method used to quantify urinary AGT. Analyzed the relationship between urinary AGT and intrarenal angiotensin II (Ang II) activity in 128 CKD patients. ELISA was applied to measure the urinary and plasma renin activity, AGT, Ang II and aldosterone. Furthermore expression levels of intrarenal renin, AGT, Ang II and Ang II receptor were examined by immunohistochemistry staining (IHCS) in 72 CKD patients undergoing renal biopsy. The logarithmic transformation Log(urinary AGT/UCre) levels showed a normal distribution. Therefore, Log(urinary AGT/UCre) levels were used for the analyses. Average urinary AGT was 2.02 ± 0.55 ng/(mg Cr). Hypertension, urinary protein, urinary Ang II and urinary type IV collagen (Col IV) positively correlated with urinary AGT. Estimated glomerular filtration rate (eGFR), urinary sodium and serum AGT negatively correlated with urinary AGT. Multiple regression analysis indicated that low serum AGT, high urinary protein, urinary Ang II and urinary Col IV correlated significantly with high urinary AGT. We observed positive correlation between urinary AGT and positive IHCS area of AGT, Ang II and Ang II type 1 receptor in renal tissue. These data suggest that urinary AGT might be a potential biomarker of intrarenal Ang II activity in CKD patients.

Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China

NASA Astrophysics Data System (ADS)

Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping

2016-06-01

Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008-2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008-2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy.

Spatiotemporal Co-existence of Female Thyroid and Breast Cancers in Hangzhou, China

PubMed Central

Fei, Xufeng; Christakos, George; Lou, Zhaohan; Ren, Yanjun; Liu, Qingmin; Wu, Jiaping

2016-01-01

Thyroid and breast cancers (TC, BC) are common female malignant tumors worldwide. Studies suggest that TC patients have a higher BC risk, and vice versa. However, it has not been investigated quantitatively if there is an association between the space-time TC and BC incidence distributions at the population level. This work aims to answer this question. 5358 TC and 8784 BC (female) cases were diagnosed in Hangzhou (China, 2008–2012). Pearson and Spearman rank correlation coefficients of the TC and BC incidences were high, and their patterns were geographically similar. The spatiotemporal co-existence of TC and BC distributions was investigated using the integrative disease predictability (IDP) criterion: if TC-BC association is part of the disease mapping knowledge bases, it should yield improved space-time incidence predictions. Improved TC (BC) incidence predictions were generated when integrating both TC and BC data than when using only TC (BC) data. IDP consistently demonstrated the spatiotemporal co-existence of TC and BC distributions throughout Hangzhou (2008–2012), which means that when the population experiences high incidences of one kind of cancer attention should be paid to the other kind of cancer too. The strength of TC-BC association was measured by the IDP coefficients and incidence prediction accuracy. PMID:27341638

Bimodality and variability of particle size distributions in high Ice Water Content regions and their implications for microphysical models

NASA Astrophysics Data System (ADS)

Zhu, S.; McFarquhar, G. M.; Leroy, D.; Korolev, A.; Schwarzenboeck, A.; Wu, W.; Strapp, J. W.

2016-12-01

Aviation records since the 1990s indicate that aircraft engines are facing a threat of occasional power loss due to ice ingestion over tropical oceanic convective clouds. The typical absence of radar echoes greater than 30 dBZ during such incidents suggests the existence of large amounts of small ice particles. The industrial aviation safety concerns inspired the High Altitude Ice Crystals / High Ice Water Content (HAIC/HIWC) campaign, whose Phase I was conducted between January and March 2014. A 2-D Stereo (2DS) probe, Precipitation Imaging Probe (PIP) and Isokinetic Evaporator Probe were installed on the French Falcon 20 making in-situ observations off the coast of Darwin, Australia. Composite particle size distributions (PSDs) using 2DS and PIP data were derived for each 5 second period in cloud. Using an automated technique to identify multiple modes in PSDs and an Incomplete Gamma Fit technique, the intercept (N0), slope (λ) and shape parameter (μ) of each mode of a gamma distribution were determined. The variation of PSDs and fit parameters for Ice Water Contents (IWCs) > 1.5 g m-3 with cloud and environmental parameters and their differences from PSDs measured outside of high IWC conditions are summarized here. Two types of HIWC conditions were observed, according to whether the median mass diameters (MMD) were positively or negatively correlated with IWC. The principal findings about high IWC regions are as follows: 1) larger μ and N0 are found in high IWC regions while λ tends to remain unchanged; 2) PSDs are more likely to be bimodal at lower temperatures. 3) Positive MMD-IWC correlations are associated with larger μ and smaller N0; 4) Bimodal distributions are more frequent for positive MMD-IWC correlations; and 5) Positive MMD-IWC correlations are usually associated with longer-aged clouds, but there are exceptions, showing other factors affect the occurrence of frequent small particles in high IWC regions. Implications for modeling of high IWC events are discussed.

Improving the detection of wind fields from LIDAR aerosol backscatter using feature extraction

NASA Astrophysics Data System (ADS)

Bickel, Brady R.; Rotthoff, Eric R.; Walters, Gage S.; Kane, Timothy J.; Mayor, Shane D.

2016-04-01

The tracking of winds and atmospheric features has many applications, from predicting and analyzing weather patterns in the upper and lower atmosphere to monitoring air movement from pig and chicken farms. Doppler LIDAR systems exist to quantify the underlying wind speeds, but cost of these systems can sometimes be relatively high, and processing limitations exist. The alternative is using an incoherent LIDAR system to analyze aerosol backscatter. Improving the detection and analysis of wind information from aerosol backscatter LIDAR systems will allow for the adoption of these relatively low cost instruments in environments where the size, complexity, and cost of other options are prohibitive. Using data from a simple aerosol backscatter LIDAR system, we attempt to extend the processing capabilities by calculating wind vectors through image correlation techniques to improve the detection of wind features.

Dark matter and cosmological nucleosynthesis

NASA Technical Reports Server (NTRS)

Schramm, D. N.

1986-01-01

Existing dark matter problems, i.e., dynamics, galaxy formation and inflation, are considered, along with a model which proposes dark baryons as the bulk of missing matter in a fractal universe. It is shown that no combination of dark, nonbaryonic matter can either provide a cosmological density parameter value near unity or, as in the case of high energy neutrinos, allow formation of condensed matter at epochs when quasars already existed. The possibility that correlations among galactic clusters are scale-free is discussed. Such a distribution of matter would yield a fractal of 1.2, close to a one-dimensional universe. Biasing, cosmic superstrings, and percolated explosions and hot dark matter are theoretical approaches that would satisfy the D = 1.2 fractal model of the large-scale structure of the universe and which would also allow sufficient dark matter in halos to close the universe.

"K" value correlation study.

DOT National Transportation Integrated Search

1972-08-01

One objective of this study was to determine what correlation existed between the modulus of subgrade reaction as determined by the Plate Bearing Test and the deflection determined by the first snsor of the Lane Wells "Dynaflect". The Research and De...

Background Noise Reduction Using Adaptive Noise Cancellation Determined by the Cross-Correlation

NASA Technical Reports Server (NTRS)

Spalt, Taylor B.; Brooks, Thomas F.; Fuller, Christopher R.

2012-01-01

Background noise due to flow in wind tunnels contaminates desired data by decreasing the Signal-to-Noise Ratio. The use of Adaptive Noise Cancellation to remove background noise at measurement microphones is compromised when the reference sensor measures both background and desired noise. The technique proposed modifies the classical processing configuration based on the cross-correlation between the reference and primary microphone. Background noise attenuation is achieved using a cross-correlation sample width that encompasses only the background noise and a matched delay for the adaptive processing. A present limitation of the method is that a minimum time delay between the background noise and desired signal must exist in order for the correlated parts of the desired signal to be separated from the background noise in the crosscorrelation. A simulation yields primary signal recovery which can be predicted from the coherence of the background noise between the channels. Results are compared with two existing methods.

Chemical composition of scales generated from oil industry and correlation to radionuclide contents and gamma-ray measurements of (210)Pb.

PubMed

Al Attar, Lina; Safia, Bassam; Abdul Ghani, Basem

2016-03-01

Scale generated from the maintenance of equipment contaminated by naturally occurring radioactive materials may contain also chemical components that cause hazardous pollution to human health and the environment. This study spotlights the characterisation of chemical pollutants in scales in relation to home-made comparison samples as no reference material for such waste exists. Analysis by energy dispersive x-ray fluorescence, with accuracy and precision better than 90%, revealed that barium was the most abundant element in scale samples, ranging from 1.4 to 38.2%. The concentrations of the toxic elements such as lead and chromium were as high as 2.5 and 1.2% respectively. Statistically, high correlation was observed between the concentration of Ba and Sr, sample density, radionuclide contents ((210)Pb and (226)Ra) and self-attenuation factor used for the radio-measurements. However, iron showed a reverse correlation. Interpretation of data with regards to the mineralogical components indicated that (226)Ra and (210)Pb co-precipitated with the insoluble salt Ba0.75Sr0.25SO4. Since both Ba and Sr have high Z, samples of high density (ρ) were accompanied with high values of self-attenuation correction factors (Cf) for the emitted radiation; correlation matrix of Pearson reached 0.935 between ρ and Cf. An attempt to eliminate the effect of the elemental composition and improve gamma measurements of (210)Pb activity concentration in scale samples was made, which showed no correction for self-attenuation was needed when sample densities were in the range 1.0-1.4 g cm(-3). For denser samples, a mathematical model was developed. Accurate determinations of radionuclide and chemical contents of scale would facilitate future Environmental Impact Assessment for the petroleum industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of surgical care improvement project inf-9 on postoperative urinary tract infections: do exemptions interfere with quality patient care?

PubMed

Owen, Rachel M; Perez, Sebastian D; Bornstein, William A; Sweeney, John F

2012-10-01

The Surgical Care Improvement Project (SCIP) Inf-9 guideline promotes removal of indwelling urinary catheters (IUCs) within 48 hours of surgery. To determine whether a correlation exists between SCIP Inf-9 compliance and postoperative urinary tract infection (UTI) rates and whether an association exists between UTI rates and SCIP Inf-9 exemption status. DESIGN Retrospective case control study. Southeastern academic medical center. American College of Surgeons National Surgical Quality Improvement Program (NSQIP) and SCIP Inf-9 compliance data were collected prospectively on randomly selected general and vascular surgery inpatients. Monthly UTI rates and SCIP Inf-9 compliance scores were tested for correlation. Complete NSQIP data for all the inpatients with postoperative UTIs were compared with a group of 100 random controls to determine whether an association exists between UTI rates and SCIP Inf-9 exemption status. Postoperative UTI. In 2459 patients reviewed, SCIP Inf-9 compliance increased over time, but this was not correlated with improved monthly UTI rates. Sixty-one of the 69 UTIs (88.4%) were compliant with SCIP Inf-9; however, 49 (71.0%) of these were considered exempt from the guideline and, therefore, the IUC was not removed within 48 hours of surgery. Retrospective review of 100 random controls showed a similar compliance rate (84.0%, P = .43) but a lower rate of exemption (23.5%, P < .001). The odds of developing a postoperative UTI were 8 times higher in patients deemed exempt from SCIP Inf-9 (odds ratio [OR], 7.99; 95% CI, 3.85-16.61). After controlling for differences between the 2 groups, the adjusted ORs slightly increased (OR, 8.34; 95% CI, 3.70-18.76). Most UTIs occurred in patients deemed exempt from SCIP Inf-9. Although compliance rates remain high, practices are not actually improving. Surgical Care Improvement Project Inf-9 guidelines should be modified with fewer exemptions to facilitate earlier removal of IUCs.

Distinct Correlation Structure Supporting a Rate-Code for Sound Localization in the Owl’s Auditory Forebrain

PubMed Central

2017-01-01

Abstract While a topographic map of auditory space exists in the vertebrate midbrain, it is absent in the forebrain. Yet, both brain regions are implicated in sound localization. The heterogeneous spatial tuning of adjacent sites in the forebrain compared to the midbrain reflects different underlying circuitries, which is expected to affect the correlation structure, i.e., signal (similarity of tuning) and noise (trial-by-trial variability) correlations. Recent studies have drawn attention to the impact of response correlations on the information readout from a neural population. We thus analyzed the correlation structure in midbrain and forebrain regions of the barn owl’s auditory system. Tetrodes were used to record in the midbrain and two forebrain regions, Field L and the downstream auditory arcopallium (AAr), in anesthetized owls. Nearby neurons in the midbrain showed high signal and noise correlations (RNCs), consistent with shared inputs. As previously reported, Field L was arranged in random clusters of similarly tuned neurons. Interestingly, AAr neurons displayed homogeneous monotonic azimuth tuning, while response variability of nearby neurons was significantly less correlated than the midbrain. Using a decoding approach, we demonstrate that low RNC in AAr restricts the potentially detrimental effect it can have on information, assuming a rate code proposed for mammalian sound localization. This study harnesses the power of correlation structure analysis to investigate the coding of auditory space. Our findings demonstrate distinct correlation structures in the auditory midbrain and forebrain, which would be beneficial for a rate-code framework for sound localization in the nontopographic forebrain representation of auditory space. PMID:28674698

Correlations between water-soluble organic aerosol and water vapor: a synergistic effect from biogenic emissions?

PubMed

Hennigan, Christopher J; Bergin, Michael H; Weber, Rodney J

2008-12-15

Ground-based measurements of meteorological parameters and water-soluble organic carbon in the gas(WSOCg) and particle (WSOCp) phases were carried out in Atlanta, Georgia, from May to September 2007. Fourteen separate events were observed throughout the summer in which WSOCp and water vapor concentrations were highly correlated (average WSOCp-water vapor r = 0.92); however, for the entire summer, no well-defined relationship existed between the two. The correlation events, which lasted on average 19 h, were characterized by a wide range of WSOCp and water vapor concentrations. Several hypotheses for the correlation are explored, including heterogeneous liquid phase SOA formation and the co-emission of biogenic VOCs and water vapor. The data provide supporting evidence for contributions from both and suggest the possibility of a synergistic effect between the co-emission of water vapor and VOCs from biogenic sources on SOA formation. Median WSOCp concentrations were also correlated with elemental carbon (EC), although this correlation extended over the entire summer. Despite the emission of water vapor from anthropogenic mobile sources and the WSOCp-EC correlation, mobile sources were not considered a potential cause for the WSOCp-water vapor correlations because of their low contribution to the water vapor budget. Meteorology could perhaps have influenced the WSOCp-EC correlation, but other factors are implicated as well. Overall, the results suggest that the temperature-dependent co-emission of water vapor through evapotranspiration and SOA precursor-VOCs by vegetation may be an important process contributing to SOA in some environments.

Nanoscale interplay of strain and doping in a high-temperature superconductor

DOE PAGES

Zeljkovic, Ilija; Gu, Genda; Nieminen, Jouko; ...

2014-11-07

The highest temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable which could be harnessed to enhance the superconducting pairing. Here we report the relationship between local doping and local strain in the cuprate superconductor Bi₂Sr₂CaCu₂O₈₊ x. We use scanning tunneling microscopy to discover that the crucial oxygen dopants are periodically distributed, in correlation with local strain. Our picoscale investigation of the intra-unit-cell positions of all oxygen dopants provides essential structural input for a complete microscopic theory.

Rapid, topology-based particle tracking for high-resolution measurements of large complex 3D motion fields.

PubMed

Patel, Mohak; Leggett, Susan E; Landauer, Alexander K; Wong, Ian Y; Franck, Christian

2018-04-03

Spatiotemporal tracking of tracer particles or objects of interest can reveal localized behaviors in biological and physical systems. However, existing tracking algorithms are most effective for relatively low numbers of particles that undergo displacements smaller than their typical interparticle separation distance. Here, we demonstrate a single particle tracking algorithm to reconstruct large complex motion fields with large particle numbers, orders of magnitude larger than previously tractably resolvable, thus opening the door for attaining very high Nyquist spatial frequency motion recovery in the images. Our key innovations are feature vectors that encode nearest neighbor positions, a rigorous outlier removal scheme, and an iterative deformation warping scheme. We test this technique for its accuracy and computational efficacy using synthetically and experimentally generated 3D particle images, including non-affine deformation fields in soft materials, complex fluid flows, and cell-generated deformations. We augment this algorithm with additional particle information (e.g., color, size, or shape) to further enhance tracking accuracy for high gradient and large displacement fields. These applications demonstrate that this versatile technique can rapidly track unprecedented numbers of particles to resolve large and complex motion fields in 2D and 3D images, particularly when spatial correlations exist.

An integrated measure of display clutter based on feature content, user knowledge and attention allocation factors.

PubMed

Pankok, Carl; Kaber, David B

2018-05-01

Existing measures of display clutter in the literature generally exhibit weak correlations with task performance, which limits their utility in safety-critical domains. A literature review led to formulation of an integrated display data- and user knowledge-driven measure of display clutter. A driving simulation experiment was conducted in which participants were asked to search 'high' and 'low' clutter displays for navigation information. Data-driven measures and subjective perceptions of clutter were collected along with patterns of visual attention allocation and driving performance responses during time periods in which participants searched the navigation display for information. The new integrated measure was more strongly correlated with driving performance than other, previously developed measures of clutter, particularly in the case of low-clutter displays. Integrating display data and user knowledge factors with patterns of visual attention allocation shows promise for measuring display clutter and correlation with task performance, particularly for low-clutter displays. Practitioner Summary: A novel measure of display clutter was formulated, accounting for display data content, user knowledge states and patterns of visual attention allocation. The measure was evaluated in terms of correlations with driver performance in a safety-critical driving simulation study. The measure exhibited stronger correlations with task performance than previously defined measures.

On one-parametric formula relating the frequencies of twin-peak quasi-periodic oscillations

NASA Astrophysics Data System (ADS)

Török, Gabriel; Goluchová, Kateřina; Šrámková, Eva; Horák, Jiří; Bakala, Pavel; Urbanec, Martin

2018-01-01

Twin-peak quasi-periodic oscillations (QPOs) are observed in several low-mass X-ray binary systems containing neutron stars. Timing the analysis of X-ray fluxes of more than dozen of such systems reveals remarkable correlations between the frequencies of two characteristic peaks present in the power density spectra. The individual correlations clearly differ, but they roughly follow a common individual pattern. High values of measured QPO frequencies and strong modulation of the X-ray flux both suggest that the observed correlations are connected to orbital motion in the innermost part of an accretion disc. Several attempts to model these correlations with simple geodesic orbital models or phenomenological relations have failed in the past. We find and explore a surprisingly simple analytic relation that reproduces individual correlations for a group of several sources through a single parameter. When an additional free parameter is considered within our relation, it well reproduces the data of a large group of 14 sources. The very existence and form of this simple relation support the hypothesis of the orbital origin of QPOs and provide the key for further development of QPO models. We discuss a possible physical interpretation of our relation's parameters and their links to concrete QPO models.

Compression of color-mapped images

NASA Technical Reports Server (NTRS)

Hadenfeldt, A. C.; Sayood, Khalid

1992-01-01

In a standard image coding scenario, pixel-to-pixel correlation nearly always exists in the data, especially if the image is a natural scene. This correlation is what allows predictive coding schemes (e.g., DPCM) to perform efficient compression. In a color-mapped image, the values stored in the pixel array are no longer directly related to the pixel intensity. Two color indices which are numerically adjacent (close) may point to two very different colors. The correlation still exists, but only via the colormap. This fact can be exploited by sorting the color map to reintroduce the structure. The sorting of colormaps is studied and it is shown how the resulting structure can be used in both lossless and lossy compression of images.

Microarray labeling extension values: laboratory signatures for Affymetrix GeneChips

PubMed Central

Lee, Yun-Shien; Chen, Chun-Houh; Tsai, Chi-Neu; Tsai, Chia-Lung; Chao, Angel; Wang, Tzu-Hao

2009-01-01

Interlaboratory comparison of microarray data, even when using the same platform, imposes several challenges to scientists. RNA quality, RNA labeling efficiency, hybridization procedures and data-mining tools can all contribute variations in each laboratory. In Affymetrix GeneChips, about 11–20 different 25-mer oligonucleotides are used to measure the level of each transcript. Here, we report that ‘labeling extension values (LEVs)’, which are correlation coefficients between probe intensities and probe positions, are highly correlated with the gene expression levels (GEVs) on eukayotic Affymetrix microarray data. By analyzing LEVs and GEVs in the publicly available 2414 cel files of 20 Affymetrix microarray types covering 13 species, we found that correlations between LEVs and GEVs only exist in eukaryotic RNAs, but not in prokaryotic ones. Surprisingly, Affymetrix results of the same specimens that were analyzed in different laboratories could be clearly differentiated only by LEVs, leading to the identification of ‘laboratory signatures’. In the examined dataset, GSE10797, filtering out high-LEV genes did not compromise the discovery of biological processes that are constructed by differentially expressed genes. In conclusion, LEVs provide a new filtering parameter for microarray analysis of gene expression and it may improve the inter- and intralaboratory comparability of Affymetrix GeneChips data. PMID:19295132

Report on the Study of Radiation Damage in Calcium Fluoride and Magnesium Fluoride Crystals for use in Excimer Laser Applications

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

None, None

1999-10-04

A study was performed to investigate the effects of radiation damage in calcium fluoride and magnesium fluoride crystals caused by gamma rays and UV photons from excimer lasers. The purpose was to study and correlate the damage caused by these two different mechanisms in various types of material used for fabricating optical elements in high power excimer lasers and lens systems of lithography tools. These optical systems are easily damaged by the laser itself, and it is necessary to use only the most radiation resistant materials for certain key elements. It was found that a clear correlation exists between the,more » radiation induced damage caused by high energy gamma rays and that produced by UV photons from the excimer laser. This correlation allows a simple procedure to be developed to select the most radiation resistant material at the ingot level, which would be later used to fabricate various components of the optical system. This avoids incurring the additional cost of fabricating actual optical elements with material that would later be damaged under prolonged use. The result of this screening procedure can result in a considerable savings in the overall cost of the lens and laser system.« less

Correlation of cerebrovascular disorder and anxiety: The Kecskemet study

NASA Astrophysics Data System (ADS)

Sipos, Kornel; Bodo, Michael; Szalay, Piroska; Szucs, Attila

2010-04-01

In order to test the hypothesis that anxiety is a risk factor for cardiovascular disease, specifically stroke, we simultaneously measured anxiety and cerebral vascular alternation, using a computer-based system, "Cerberus." Sixty nine psychiatric patients (including an alcoholic subgroup) were selected as subjects for measurements conducted in Kecskemet, Hungary. The five-item short form of anxiety test (STAI) was administered twice during the same session. Between each test, brain pulse waves were recorded by rheoencephalogram (REG). A REG peak time above 180 milliseconds was considered a cerebrovascular alteration (modified after Jenkner). Data were sorted into two groups: low anxiety (N=10) and high anxiety (N=10). Significant differences were found between cardiovascular risk factors (p< 0.001), REG peak time (p<0.043), and heart rate (p< 0.045). Six subjects showed cerebrovascular alteration in the high anxiety group, and two in the low anxiety group. For the two anxiety groups, there were no significant differences in body mass index, cardiovascular sympathetic-parasympathetic balance, age and symptoms of transient ischemic attack. The correlation of REG and age was significantly different only for the alcoholic subgroup (Szalay et al, 2007). These data support the hypothesis that a correlation exists between cerebrovascular disorder and anxiety in the studied population.

Optical coherence tomography in retinitis pigmentosa: reproducibility and capacity to detect macular and retinal nerve fiber layer thickness alterations.

PubMed

Garcia-Martin, Elena; Pinilla, Isabel; Sancho, Eva; Almarcegui, Carmen; Dolz, Isabel; Rodriguez-Mena, Diego; Fuertes, Isabel; Cuenca, Nicolas

2012-09-01

To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

Multi-Resolution Climate Ensemble Parameter Analysis with Nested Parallel Coordinates Plots.

PubMed

Wang, Junpeng; Liu, Xiaotong; Shen, Han-Wei; Lin, Guang

2017-01-01

Due to the uncertain nature of weather prediction, climate simulations are usually performed multiple times with different spatial resolutions. The outputs of simulations are multi-resolution spatial temporal ensembles. Each simulation run uses a unique set of values for multiple convective parameters. Distinct parameter settings from different simulation runs in different resolutions constitute a multi-resolution high-dimensional parameter space. Understanding the correlation between the different convective parameters, and establishing a connection between the parameter settings and the ensemble outputs are crucial to domain scientists. The multi-resolution high-dimensional parameter space, however, presents a unique challenge to the existing correlation visualization techniques. We present Nested Parallel Coordinates Plot (NPCP), a new type of parallel coordinates plots that enables visualization of intra-resolution and inter-resolution parameter correlations. With flexible user control, NPCP integrates superimposition, juxtaposition and explicit encodings in a single view for comparative data visualization and analysis. We develop an integrated visual analytics system to help domain scientists understand the connection between multi-resolution convective parameters and the large spatial temporal ensembles. Our system presents intricate climate ensembles with a comprehensive overview and on-demand geographic details. We demonstrate NPCP, along with the climate ensemble visualization system, based on real-world use-cases from our collaborators in computational and predictive science.

Expressions of miR-30c and let-7a are inversely correlated with HMGA2 expression in squamous cell carcinoma of the vulva.

PubMed

Agostini, Antonio; Brunetti, Marta; Davidson, Ben; Trope, Claes G; Heim, Sverre; Panagopoulos, Ioannis; Micci, Francesca

2016-12-20

Malignant tumors of the vulva, most of them squamous cell carcinomas, account for only 5% of cancers of the female genital tract. Though little is known about the genetic features of these tumors, the Fragile Histidine Triad (FHIT) and High Mobility Group AT-hook 2 (HMGA2) genes were found deregulated. We wanted to gain more knowledge about the expression of HMGA2-related miRNAs such as miR-30c and let-7a, and whether a correlation exists between the expression of FHIT and HMGA2, in this tumor type. An inverse correlation was found in-as-much as HMGA2 was highly expressed (mean fold change 8.8) whereas miR30c and let-7a were both downregulated (mean fold change -3.9 and -2.3, respectively). The consistent overexpression of HMGA2 found in all tumors adds to the likelihood that this gene is of importance in SCC pathogenesis. Moreover, we came to the conclusion that miRNAs may be the cause of the deregulation of HMGA2. Our results also show that SCC of the vulva presents a characteristic molecular pattern with FHIT being downregulated whereas HMGA2 is upregulated.

Expressions of miR-30c and let-7a are inversely correlated with HMGA2 expression in squamous cell carcinoma of the vulva

PubMed Central

Agostini, Antonio; Brunetti, Marta; Davidson, Ben; Trope, Claes G.; Heim, Sverre; Panagopoulos, Ioannis; Micci, Francesca

2016-01-01

Malignant tumors of the vulva, most of them squamous cell carcinomas, account for only 5% of cancers of the female genital tract. Though little is known about the genetic features of these tumors, the Fragile Histidine Triad (FHIT) and High Mobility Group AT-hook 2 (HMGA2) genes were found deregulated. We wanted to gain more knowledge about the expression of HMGA2-related miRNAs such as miR-30c and let-7a, and whether a correlation exists between the expression of FHIT and HMGA2, in this tumor type. An inverse correlation was found in-as-much as HMGA2 was highly expressed (mean fold change 8.8) whereas miR30c and let-7a were both downregulated (mean fold change -3.9 and -2.3, respectively). The consistent overexpression of HMGA2 found in all tumors adds to the likelihood that this gene is of importance in SCC pathogenesis. Moreover, we came to the conclusion that miRNAs may be the cause of the deregulation of HMGA2. Our results also show that SCC of the vulva presents a characteristic molecular pattern with FHIT being downregulated whereas HMGA2 is upregulated. PMID:27835588

Trichotillomania symptoms in African American women: are they related to anxiety and culture?

PubMed

Neal-Barnett, Angela; Statom, Deborah; Stadulis, Robert

2011-08-01

Trichotillomania (TTM) is a little understood disorder that has been underresearched in the African American community. Furthermore, the incorporation of cultural factors into TTM research has virtually been ignored. Existing data from an African American college student population suggest TTM is associated with high levels of anxiety. In this study, we explored anxiety symptoms and cultural hair messages in an African American female community sample with TTM symptoms. We predicted high levels of TTM severity and impairment would be associated with high level of anxiety symptoms. We also predicted that cultural messages about hair will influence both TTM and anxiety symptoms. In this telephone study, 41 African American females participated in interviews about their TTM. TTM impairment and severity was positively correlated with general anxiety symptoms as measured on the Symptom Checklist 90-Revised (SCL 90-R(®) ). Severity was also positively correlated with obsessive-compulsive symptoms. Given the significance of hair for African American women, we also explored the childhood cultural messages receive about hair. Over half the sample received at least one cultural message about hair. Although many women received the same message, the value they placed on the message differed. Messages received about hair were not associated with TTM severity or impairment. The association among obsessive-compulsive symptoms and hair messages approached significance. Results highlight the importance of assessing anxiety comorbidity and culture with African American TTM samples. Little is known about TTM in African American samples. Existing research indicates this population seeks TTM help from their hairdressers. Among college students, a significant correlation has been found for anxiety as measured on the Beck Anxiety Inventory and TTM. To the best of our knowledge, this is the first paper to examine cultural messages about hair in an African American sample. In addition, rather than looking at college students, this research is conducted with a community sample of mostly professional African American women. The use of the SCL-90-R(®) specific anxiety dimensions demonstrates the relationship with TTM severity and impairment. © 2010 Blackwell Publishing Ltd.

Does asymmetric correlation affect portfolio optimization?

NASA Astrophysics Data System (ADS)

Fryd, Lukas

2017-07-01

The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

Developing a prototype for short-term psychodynamic (supportive-expressive) therapy: An empirical study with the psychotherapy process Q-set.

PubMed

Leichsenring, Falk; Ablon, Stuart; Barber, Jacques P; Beutel, Manfred; Gibbons, Mary Beth Connolly; Crits-Christoph, Paul; Klein, Susanne; Leweke, Frank; Steinert, Christiane; Wiltink, Jörg; Salzer, Simone

2016-07-01

A Psychotherapy Process Q-set (PQS) prototype characteristic of short-term psychodynamic therapy (STPP) does not yet exist. Experts in supportive-expressive (SE) therapy used the 100-Item PQS questionnaire to rate an ideal short-term SE therapy. Agreement between raters was high (Cronbach's alpha = 0.94). The prototype for SE therapy showed a significant correlation with the psychoanalytic prototype, but with 28% of variance explained, the majority of variance of the former was not explained by the latter or vice versa. Furthermore, the SE prototype showed significant correlations with the cognitive-behavioral prototype and the prototype of interpersonal therapy by Ablon and Jones (r = 0.69, 0.43). We recommend using the PQS prototype presented here for future process research on STPP.

Antibody-dependent enhancement of severe dengue disease in humans*

PubMed Central

Katzelnick, Leah C.; Gresh, Lionel; Halloran, M. Elizabeth; Mercado, Juan Carlos; Kuan, Guillermina; Gordon, Aubree; Balmaseda, Angel; Harris, Eva

2018-01-01

For dengue viruses (DENV1-4), a specific range of antibody titer has been shown to enhance viral replication in vitro and severe disease in animal models. Although suspected, such antibody-dependent enhancement (ADE) of severe disease has not been shown to occur in humans. Using multiple statistical approaches to study a long-term pediatric cohort in Nicaragua, we show that risk of severe dengue disease is highest within a narrow range of pre-existing anti-DENV antibody titers. By contrast, we observe protection from all symptomatic dengue disease at high antibody titers. Thus, immune correlates of severe dengue must be evaluated separately from correlates of protection against symptomatic disease. These results have implications for studies of dengue pathogenesis and for vaccine development, because enhancement, not just lack of protection, is of concern. PMID:29097492

Optic Nerve Assessment Using 7-Tesla Magnetic Resonance Imaging

PubMed Central

Singh, Arun D.; Platt, Sean M.; Lystad, Lisa; Lowe, Mark; Oh, Sehong; Jones, Stephen E.; Alzahrani, Yahya; Plesec, Thomas

2016-01-01

Purpose The purpose of this study was to correlate high-resolution magnetic resonance imaging (MRI) and histologic findings in a case of juxtapapillary choroidal melanoma with clinical evidence of optic nerve invasion. Methods With institutional review board approval, an enucleated globe with choroidal melanoma and optic nerve invasion was imaged using a 7-tesla MRI followed by histopathologic evaluation. Results Optical coherence tomography, B-scan ultrasonography, and 1.5-tesla MRI of the orbit (1-mm sections) could not detect optic disc invasion. Ex vivo, 7-tesla MRI detected optic nerve invasion, which correlated with histopathologic features. Conclusions Our case demonstrates the potential to document the existence of optic nerve invasion in the presence of an intraocular tumor, a feature that has a major bearing on decision making, particularly for consideration of enucleation. PMID:27239461

The contact of a homogeneous unitary Fermi gas

NASA Astrophysics Data System (ADS)

Mukherjee, Biswaroop; Patel, Parth; Yan, Zhenjie; Fletcher, Richard; Struck, Julian; Zwierlein, Martin

2017-04-01

The contact is a fundamental quantity that measures the strength of short-range correlations in quantum gases. As one of its most important implications, it provides a link between the microscopic two-particle correlation function at small distance and the macroscopic thermodynamic properties of the gas. In particular, pairing and superfluidity in a unitary Fermi gas can be expected to leave its mark in behavior of the contact. Here we present measurements on the temperature dependence of the contact of a unitary Fermi gas across the superfluid transition. By trapping ultracold 6Li atoms in a potential that is homogeneous in two directions and harmonic in the third, we obtain radiofrequency spectra of the homogeneous gas at a high signal-to-noise ratio. We compare our data to existing, but often mutually excluding theoretical calculations for the strongly interacting Fermi gas.

The Correlation between Chemical Structures and Antioxidant, Prooxidant, and Antitrypanosomatid Properties of Flavonoids

PubMed Central

de Alcântara, Bianca Gonçalves Vasconcelos; Domingos, Olívia da Silva

2017-01-01

Flavonoids have demonstrated in vivo and in vitro leishmanicidal, trypanocidal, antioxidant, and prooxidant properties. The chemotherapy of trypanosomiasis and leishmaniasis lacks efficacy, presents high toxicity, and is related to the development of drug resistance. Thus, a series of 40 flavonoids were investigated with the purpose of correlating these properties via structure and activity analyses based on integrated networks and QSAR models. The classical groups for the antioxidant activity of flavonoids were combined in order to explain the influence of antioxidant and prooxidant activities on the antiparasitic properties. These analyses become useful for the development of efficient treatments for leishmaniasis and trypanosomiasis. Finally, the dual activity of flavonoids presenting both anti- and prooxidant activities revealed that the existence of a balance between these two features could be important to the development of adequate therapeutic strategies. PMID:28751930

A hybrid method based on Band Pass Filter and Correlation Algorithm to improve debris sensor capacity

NASA Astrophysics Data System (ADS)

Hong, Wei; Wang, Shaoping; Liu, Haokuo; Tomovic, Mileta M.; Chao, Zhang

2017-01-01

The inductive debris detection is an effective method for monitoring mechanical wear, and could be used to prevent serious accidents. However, debris detection during early phase of mechanical wear, when small debris (<100 um) is generated, requires that the sensor has high sensitivity with respect to background noise. In order to detect smaller debris by existing sensors, this paper presents a hybrid method which combines Band Pass Filter and Correlation Algorithm to improve sensor signal-to-noise ratio (SNR). The simulation results indicate that the SNR will be improved at least 2.67 times after signal processing. In other words, this method ensures debris identification when the sensor's SNR is bigger than -3 dB. Thus, smaller debris will be detected in the same SNR. Finally, effectiveness of the proposed method is experimentally validated.

Predicting intentions versus predicting behaviors: domestic violence prevention from a theory of reasoned action perspective.

PubMed

Nabi, Robin L; Southwell, Brian; Hornik, Robert

2002-01-01

A central assumption of many models of human behavior is that intention to perform a behavior is highly predictive of actual behavior. This article presents evidence that belies this notion. Based on a survey of 1,250 Philadelphia adults, a clear and consistent pattern emerged suggesting that beliefs related to domestic violence correlate with intentions to act with respect to domestic violence but rarely correlate with reported actions (e.g., talking to the abused woman). Numerous methodological and substantive explanations for this finding are offered with emphasis placed on the complexity of the context in which an action to prevent a domestic violence incident occurs. We conclude by arguing that despite the small, insignificant relationships between beliefs and behaviors found, worthwhile aggregate effects on behavior might still exist, thus reaffirming the role of communication campaign efforts.

Selecting band combinations with thematic mapper data

NASA Technical Reports Server (NTRS)

Sheffield, C. A.

1983-01-01

A problem arises in making color composite images because there are 210 different possible color presentations of TM three-band images. A method is given for reducing that 210 to a single choice, decided by the statistics of a scene or subscene, and taking into full account any correlations that exist between different bands. Instead of using total variance as the measure for information content of the band triplets, the ellipsoid of maximum volume is selected which discourages selection of bands with high correlation. The band triplet is obtained by computing and ranking in order the determinants of each 3 x 3 principal submatrix of the original matrix M. After selection of the best triplet, the assignment of colors is made by using the actual variances (the diagonal elements of M): green (maximum variance), red (second largest variance), blue (smallest variance).

Correlations among the parameters of the spherical model for eclipsing binaries.

NASA Technical Reports Server (NTRS)

Sobieski, S.; White, J.

1973-01-01

Correlation coefficients have been computed to investigate the parameters used to describe the spherical model of an eclipsing binary system. Regions in parameter hyperspace have been identified where strong correlations exist and, by implication, the solution determinacy is low. The results are presented in tabular form for a large number of system configurations.

Multilabel learning via random label selection for protein subcellular multilocations prediction.

PubMed

Wang, Xiao; Li, Guo-Zheng

2013-01-01

Prediction of protein subcellular localization is an important but challenging problem, particularly when proteins may simultaneously exist at, or move between, two or more different subcellular location sites. Most of the existing protein subcellular localization methods are only used to deal with the single-location proteins. In the past few years, only a few methods have been proposed to tackle proteins with multiple locations. However, they only adopt a simple strategy, that is, transforming the multilocation proteins to multiple proteins with single location, which does not take correlations among different subcellular locations into account. In this paper, a novel method named random label selection (RALS) (multilabel learning via RALS), which extends the simple binary relevance (BR) method, is proposed to learn from multilocation proteins in an effective and efficient way. RALS does not explicitly find the correlations among labels, but rather implicitly attempts to learn the label correlations from data by augmenting original feature space with randomly selected labels as its additional input features. Through the fivefold cross-validation test on a benchmark data set, we demonstrate our proposed method with consideration of label correlations obviously outperforms the baseline BR method without consideration of label correlations, indicating correlations among different subcellular locations really exist and contribute to improvement of prediction performance. Experimental results on two benchmark data sets also show that our proposed methods achieve significantly higher performance than some other state-of-the-art methods in predicting subcellular multilocations of proteins. The prediction web server is available at >http://levis.tongji.edu.cn:8080/bioinfo/MLPred-Euk/ for the public usage.

Improving overly manufacturing metrics through application of feedforward mask-bias

NASA Astrophysics Data System (ADS)

Joubert, Etienne; Pellegrini, Joseph C.; Misra, Manish; Sturtevant, John L.; Bernhard, John M.; Ong, Phu; Crawshaw, Nathan K.; Puchalski, Vern

2003-06-01

Traditional run-to-run controllers that rely on highly correlated historical events to forecast process corrections have been shown to provide substantial benefit over manual control in the case of a fab that is primarily manufacturing high volume, frequent running parts (i.e., DRAM, MPU, and similar operations). However, a limitation of the traditional controller emerges when it is applied to a fab whose work in process (WIP) is composed of primarily short-running, high part count products (typical of foundries and ASIC fabs). This limitation exists because there is a strong likelihood that each reticle has a unique set of process corrections different from other reticles at the same process layer. Further limitations exist when it is realized that each reticle is loaded and aligned differently on multiple exposure tools.A structural change in how the run-to-run controller manages the frequent reticle changes associated with the high part count environment has allowed for breakthrough performance to be achieved. This breakthrough was mad possible by the realization that; 1. Reticle sourced errors were highly stable over long periods of time, thus allowing them to be deconvolved from the day to day tool and process drifts. 2. Reticle sourced errors can be modeled as a feedforward disturbance rather than as discriminates in defining and dividing process streams. In this paper, we show how to deconvolve the static (reticle) and dynamic (day to day tool and process) components from the overall error vector to better forecast feedback for existing products as well as how to compute or learn these values for new product introductions - or new tool startups. Manufacturing data will presented to support this discussion with some real world success stories.

The Coordinate Orthogonality Check (corthog)

NASA Astrophysics Data System (ADS)

Avitabile, P.; Pechinsky, F.

1998-05-01

A new technique referred to as the coordinate orthogonality check (CORTHOG) helps to identify how each physical degree of freedom contributes to the overall orthogonality relationship between analytical and experimental modal vectors on a mass-weighted basis. Using the CORTHOG technique together with the pseudo-orthogonality check (POC) clarifies where potential discrepancies exist between the analytical and experimental modal vectors. CORTHOG improves the understanding of the correlation (or lack of correlation) that exists between modal vectors. The CORTHOG theory is presented along with the evaluation of several cases to show the use of the technique.

The associations between parenting styles and proactive and reactive aggression in Hong Kong children and adolescents.

PubMed

Gao, Yu; Zhang, Wei; Fung, Annis Lai Chu

2015-12-01

Previous research suggests that reactive and proactive aggression may be differentially related to family contextual (e.g. parenting practices) factors. However, the existing research has focused largely on children and adolescents from Western countries, and no study has examined the parenting-aggression association using a parenting style measure sensitive to Asian culture. In this study parenting styles (i.e. warmth, control and guan/training) and proactive and reactive aggression were assessed in a large sample of school children in Hong Kong, China (N = 4,175, mean age = 11.75). We found that: (a) both low warmth (in boys only) and guan (i.e. high expectation and close supervision, in both boys and girls) were associated with elevated parent-reported proactive aggression, (b) high restrictive control (i.e. dominating and rejecting) was associated with high reactive aggression (in both boys and girls) based on parent- or child-report data, and with high proactive aggression (in boys only) based on parent-report data, and (c) guan was also positively associated with parent-reported reactive aggression. Findings provide more information about the Parenting Inventory using a large Asian sample, and extend existing research on familial correlates of different types of aggression. © 2014 International Union of Psychological Science.

Reconstructing the history of the Atlantic Multidecadal Oscillation using high-resolution Mg/Ca paleothermometry from a Cariaco Basin core

NASA Astrophysics Data System (ADS)

Wurtzel, J. B.; Black, D. E.; Rahman, S.; Thunell, R.; Peterson, L. C.; Tappa, E.

2010-12-01

Instrumental and proxy-reconstructions show the existence of an approximately 70-year periodicity in Atlantic sea surface temperature (SST), known as the Atlantic Multidecadal Oscillation (AMO). The AMO is correlated with circum-tropical Atlantic climate phenomena such as Sahel and Nordeste rainfall, and Atlantic hurricane patterns. Though it has been suggested that the AMO is controlled by thermohaline circulation, much debate exists as to whether the SST fluctuations are a result of anthropogenic forcing or a natural climate mode, or even if the AMO is a true oscillation at all. Our ability to address this issue has been limited by instrumental SST records that rarely extend back more than 50-100 years and proxy reconstructions that are mostly terrestrial-based. Additionally, the modern instrumental variability likely contains an anthropogenic component that is not easily distinguished from the natural background of the system. From a marine sediment core taken in the Cariaco Basin, we have developed a high-resolution SST reconstruction for the past ca. 1500 years using Mg/Ca paleothermometry on seasonally-representative foraminifera, with the most recent data calibrated to the instrumental record. Previous studies have shown Cariaco Basin Mg/Ca-SSTs to be well-correlated to the Caribbean Sea and much of the western tropical Atlantic, which allows us to create a record that can be used to determine pre-anthropogenic rates and ranges of SST variability and observe how they change over time. Averaging the seasonal temperatures derived from the two foraminiferal species over the instrumental period yields a strong correlation to the AMO index from A. D. 1880 through 1970 (r = 0.44, p<0.0001). Wavelet analysis of the proxy average annual SST data indicates that modern AMO variability is not a consistent feature through time, and may be a function of warm-period climate.

Finger vein recognition based on the hyperinformation feature

NASA Astrophysics Data System (ADS)

Xi, Xiaoming; Yang, Gongping; Yin, Yilong; Yang, Lu

2014-01-01

The finger vein is a promising biometric pattern for personal identification due to its advantages over other existing biometrics. In finger vein recognition, feature extraction is a critical step, and many feature extraction methods have been proposed to extract the gray, texture, or shape of the finger vein. We treat them as low-level features and present a high-level feature extraction framework. Under this framework, base attribute is first defined to represent the characteristics of a certain subcategory of a subject. Then, for an image, the correlation coefficient is used for constructing the high-level feature, which reflects the correlation between this image and all base attributes. Since the high-level feature can reveal characteristics of more subcategories and contain more discriminative information, we call it hyperinformation feature (HIF). Compared with low-level features, which only represent the characteristics of one subcategory, HIF is more powerful and robust. In order to demonstrate the potential of the proposed framework, we provide a case study to extract HIF. We conduct comprehensive experiments to show the generality of the proposed framework and the efficiency of HIF on our databases, respectively. Experimental results show that HIF significantly outperforms the low-level features.

Structure of public transit costs in the presence of multiple serial correlation

DOT National Transportation Integrated Search

1999-12-01

Most studies indicate that public transit systems operate under increasing returns to capital stock utilization and are significantly overcapitalized. Existing flexible form time series analyses, however, fail to correct for serial correlation. In th...

Accelerated Dynamic Corrosion Test Method Development

DTIC Science & Technology

test method has poor correlation to outdoor exposures, particularly for non-chromate primers. As a result, more realistic cyclic environmental...exposures have been developed to more closely resemble actual atmospheric corrosion damage. Several existing tests correlate well with the outdoor performance

Local newspapers, drinking water pathways, and dimensions of knowledge: Public awareness amid the hydrofracking debate

NASA Astrophysics Data System (ADS)

Berg, Weston

Studies on determinants of pro-environmental behavior have found environmental knowledge to be a prerequisite for public participation. While much has been written on correlations between media coverage and environmental knowledge in general, a gap exists concerning the linkages between media coverage and knowledge of an individual's local environment. This study measures public awareness of local drinking water supplies in urban communities, using a face-to-face survey of 90 respondents in three upstate New York cities. The findings show no significant correlation between newspaper coverage of local water issues and awareness of one's drinking water source; however, the surveys revealed high correlations between such awareness and home ownership (as opposed to renting) and between awareness and receiving a water bill. In addition, there was a positive correlation between reading about a local water-related issue (in this case, hydraulic fracturing for natural gas in the Marcellus Shale) in a local newspaper and possessing basic knowledge of that issue. These findings contribute to previous research on environmental knowledge, and have practical applications in efforts addressing: civic engagement, public understanding of science, citizen participation, and democratic practices. Keywords: Public understanding, environmental communication, water resources management, hydraulic fracturing, schema theory

Cots Correlator Platform

NASA Astrophysics Data System (ADS)

Schaaf, Kjeld; Overeem, Ruud

2004-06-01

Moore’s law is best exploited by using consumer market hardware. In particular, the gaming industry pushes the limit of processor performance thus reducing the cost per raw flop even faster than Moore’s law predicts. Next to the cost benefits of Common-Of-The-Shelf (COTS) processing resources, there is a rapidly growing experience pool in cluster based processing. The typical Beowulf cluster of PC’s supercomputers are well known. Multiple examples exists of specialised cluster computers based on more advanced server nodes or even gaming stations. All these cluster machines build upon the same knowledge about cluster software management, scheduling, middleware libraries and mathematical libraries. In this study, we have integrated COTS processing resources and cluster nodes into a very high performance processing platform suitable for streaming data applications, in particular to implement a correlator. The required processing power for the correlator in modern radio telescopes is in the range of the larger supercomputers, which motivates the usage of supercomputer technology. Raw processing power is provided by graphical processors and is combined with an Infiniband host bus adapter with integrated data stream handling logic. With this processing platform a scalable correlator can be built with continuously growing processing power at consumer market prices.

The prevalence of dyspepsia symptoms and its correlation with the quality of life among Qashqai Turkish migrating nomads in Fars Province, Southern Iran

PubMed Central

Masoumi, Seyed Jalil; Mehrabani, Davood; Moradi, Fariba; Zare, Najaf; Saberi-Firouzi, Mehdi; Mazloom, Zohreh

2015-01-01

Objectives: To determine the prevalence of dyspepsia and its correlation with quality of life in Fars Qashqai Turkish migrating nomads from Southern Iran. Methods: During 2010 we enrolled 397 Qashqai migrating nomads from Southern Iran who were 25 years of age or older. Participants completed a questionnaire that consisted of demographic factors, lifestyle data, gastrointestinal symptoms, and the Short-Form 36 Health Survey (SF-36) questionnaire. Results: There was a 48% prevalence of dyspepsia symptoms among participants. The prevalence was higher among females, those less than 35 years of age, married participants, and those with a low body mass index (BMI). The correlation between dyspepsia and quality of life was significant. Dyspeptic patients were classified into ulcer-like (27.9%), dysmotility-like (26.2%), and unspecified (45.9%) groups. A significant correlation existed between dyspepsia symptoms and consumption of dairy products, drinking water and tea before and after meals, smoking, dysphagia, reflux, heartburn, and use of non-steroid anti-inflammatory drugs and acetaminophen. Conclusion: The high prevalence of dyspepsia in Qashqai nomads necessitates educational health programs for the migrating tribes in order to decrease prevalence of this disease. PMID:26101484

Feature Selection Using Information Gain for Improved Structural-Based Alert Correlation

PubMed Central

Siraj, Maheyzah Md; Zainal, Anazida; Elshoush, Huwaida Tagelsir; Elhaj, Fatin

2016-01-01

Grouping and clustering alerts for intrusion detection based on the similarity of features is referred to as structurally base alert correlation and can discover a list of attack steps. Previous researchers selected different features and data sources manually based on their knowledge and experience, which lead to the less accurate identification of attack steps and inconsistent performance of clustering accuracy. Furthermore, the existing alert correlation systems deal with a huge amount of data that contains null values, incomplete information, and irrelevant features causing the analysis of the alerts to be tedious, time-consuming and error-prone. Therefore, this paper focuses on selecting accurate and significant features of alerts that are appropriate to represent the attack steps, thus, enhancing the structural-based alert correlation model. A two-tier feature selection method is proposed to obtain the significant features. The first tier aims at ranking the subset of features based on high information gain entropy in decreasing order. The‏ second tier extends additional features with a better discriminative ability than the initially ranked features. Performance analysis results show the significance of the selected features in terms of the clustering accuracy using 2000 DARPA intrusion detection scenario-specific dataset. PMID:27893821

Mental Task Classification Scheme Utilizing Correlation Coefficient Extracted from Interchannel Intrinsic Mode Function.

PubMed

Rahman, Md Mostafizur; Fattah, Shaikh Anowarul

2017-01-01

In view of recent increase of brain computer interface (BCI) based applications, the importance of efficient classification of various mental tasks has increased prodigiously nowadays. In order to obtain effective classification, efficient feature extraction scheme is necessary, for which, in the proposed method, the interchannel relationship among electroencephalogram (EEG) data is utilized. It is expected that the correlation obtained from different combination of channels will be different for different mental tasks, which can be exploited to extract distinctive feature. The empirical mode decomposition (EMD) technique is employed on a test EEG signal obtained from a channel, which provides a number of intrinsic mode functions (IMFs), and correlation coefficient is extracted from interchannel IMF data. Simultaneously, different statistical features are also obtained from each IMF. Finally, the feature matrix is formed utilizing interchannel correlation features and intrachannel statistical features of the selected IMFs of EEG signal. Different kernels of the support vector machine (SVM) classifier are used to carry out the classification task. An EEG dataset containing ten different combinations of five different mental tasks is utilized to demonstrate the classification performance and a very high level of accuracy is achieved by the proposed scheme compared to existing methods.

Clinicopathologic and prognostic implications of progranulin in breast carcinoma.

PubMed

Li, Li-qin; Huang, Hui-lian; Ping, Jin-liang; Wang, Xiao-hong; Zhong, Jing; Dai, Li-cheng

2011-07-05

Progranulin is a newly discovered 88-kDa glycoprotein originally purified from the highly tumorigenic mouse teratoma-derived cell line PC. Its expression is closely correlated with the development and metastasis of several cancers. However, no immunohistochemical evidence currently exists to correlate progranulin expression with clinicopathologic features in breast carcinoma biopsies, and the role of progranulin as a new marker of metastatic risk and prognosis in breast cancer has not yet been studied. The aim of this study was to investigate the clinicopathologic and prognostic implications of progranulin expression in breast carcinoma and its correlation with tumor angiogenesis. Progranulin expression was determined immunohistochemically in 183 surgical specimens from patients with breast cancer and 20 tissue samples from breast fibroadenomas. The tumor angiogenesis-related biomarker, vascular endothelial growth factor was assayed and microvessel density was assessed by counting vascular endothelial cells in tumor tissues labeled with endoglin antibody. The relationship between progranulin expression and the clinicopathologic data were analyzed. Progranulin proteins were overexpressed in breast cancer. The level of progranulin expression was significantly correlated with tumor size (P = 0.004), lymph node metastasis (P < 0.001) and TNM staging (P < 0.001). High progranulin expression was associated with higher tumor angiogenesis, reflected by increased vascular endothelial growth factor expression (P < 0.001) and higher microvessel density (P = 0.002). Progranulin may be a valuable marker for assessing the metastasis and prognosis of breast cancer, and could provide the basis for new combination regimens with antiangiogenic activity.

Recovery performance in xylem hydraulic conductivity is correlated with cavitation resistance for temperate deciduous tree species.

PubMed

Ogasa, Mayumi; Miki, Naoko H; Murakami, Yuki; Yoshikawa, Ken

2013-04-01

Woody species hydraulically vulnerable to xylem cavitation may experience daily xylem embolism. How such species cope with the possibility of accumulated embolism is unclear. In this study, we examined seven temperate woody species to assess the hypothesis that low cavitation resistance (high vulnerability to cavitation) is compensated by high recovery performance via vessel refilling. We also evaluated leaf functional and xylem structural traits. The xylem recovery index (XRI), defined as the ratio of xylem hydraulic conductivity in plants rewatered after soil drought to that in plants under moist conditions, varied among species. The xylem water potential causing 50% loss of hydraulic conductivity (Ψ50) varied among the species studied, whereas only a slight difference was detected with respect to midday xylem water potential (Ψmin), indicating smaller hydraulic safety margins (Ψmin - Ψ50) for species more vulnerable to cavitation. Cavitation resistance (|Ψ50|) was negatively correlated with XRI across species, with cavitation-vulnerable species showing a higher performance in xylem recovery. Wood density was positively correlated with cavitation resistance and was negatively correlated with XRI. These novel results reveal that coordination exists between cavitation resistance and xylem recovery performance, in association with wood functional traits such as denser wood for cavitation-resistant xylem and less-dense but water-storable wood for refillable xylem. These findings provide insights into long-term maintenance of water transport in tree species growing under variable environmental conditions.

The relationship of geophysical measurements to engineering and construction parameters in the Straight Creek Tunnel pilot bore, Colorado

USGS Publications Warehouse

Scott, J.H.; Lee, F.T.; Carroll, R.D.; Robinson, C.S.

1968-01-01

Seismic-refraction and electrical-resistivity measurements made along the walls of the Straight Creek Tunnel pilot bore indicate that both a low-velocity and a high-resistivity layer exist in the disturbed rock surrounding the excavation. Seismic measurements were analyzed to obtain the thickness and seismic velocity of rock in the low-velocity layer, the velocity of rock behind the layer and the amplitude of seismic energy received at the detectors. Electrical-resistivity measurements were analyzed to obtain the thickness and electrical resistivity of the high-resistivity layer and the resistivity of rock behind the layer. The electrical resistivity and the seismic velocity of rock at depth, the thickness of rock in the low-velocity layer, and the relative amplitude of seismic energy were correlated against the following parameters, all of which are important in tunnel construction: height of the tension arch, stable vertical rock load, rock quality, rate of construction and cost per foot, percentage of lagging and blocking, set spacing, and type and amount of steel support required, The correlations were statistically meaningful, having correlation coefficients ranging in absolute value from about 0??7 to nearly 1??0. This finding suggests the possibility of predicting parameters of interest in tunnel construction from geophysical measurements made in feeler holes drilled ahead of a working face. Predictions might be based on correlations established either during the early stages of construction or from geophysical surveys in other tunnels of similar design in similar geologic environments. ?? 1968.

Estimation of static parameters based on dynamical and physical properties in limestone rocks

NASA Astrophysics Data System (ADS)

Ghafoori, Mohammad; Rastegarnia, Ahmad; Lashkaripour, Gholam Reza

2018-01-01

Due to the importance of uniaxial compressive strength (UCS), static Young's modulus (ES) and shear wave velocity, it is always worth to predict these parameters from empirical relations that suggested for other formations with same lithology. This paper studies the physical, mechanical and dynamical properties of limestone rocks using the results of laboratory tests which carried out on 60 the Jahrum and the Asmari formations core specimens. The core specimens were obtained from the Bazoft dam site, hydroelectric supply and double-curvature arch dam in Iran. The Dynamic Young's modulus (Ed) and dynamic Poisson ratio were calculated using the existing relations. Some empirical relations were presented to estimate uniaxial compressive strength, as well as static Young's modulus and shear wave velocity (Vs). Results showed the static parameters such as uniaxial compressive strength and static Young's modulus represented low correlation with water absorption. It is also found that the uniaxial compressive strength and static Young's modulus had high correlation with compressional wave velocity and dynamic Young's modulus, respectively. Dynamic Young's modulus was 5 times larger than static Young's modulus. Further, the dynamic Poisson ratio was 1.3 times larger than static Poisson ratio. The relationship between shear wave velocity (Vs) and compressional wave velocity (Vp) was power and positive with high correlation coefficient. Prediction of uniaxial compressive strength based on Vp was better than that based on Vs . Generally, both UCS and static Young's modulus (ES) had good correlation with Ed.

Dry eye in patients with fibromyalgia and its relevance to functional and emotional status.

PubMed

Türkyilmaz, Kemal; Türkyilmaz, Ayşegül Küçükali; Kurt, Emine Eda; Kurt, Ali; Öner, Veysi

2013-06-01

To evaluate dry eye in patients with fibromyalgia (FM). Fifty-three FM patients and 53 age and sex well-matched controls were included in this study. Visual analog scale (VAS), number of tender points, FM impact questionnaire (FIQ), Beck depression scale (BDS), Ocular Surface Disease Index (OSDI), the tear break-up time (TBUT), Schirmer test, and tear osmolarity (TO) were assessed. The OSDI, TBUT, Schirmer test, and TO scores of the FM and control groups were significantly different (P < 0.05). The OSDI, TBUT, Schirmer test, and TO were higher in FM with high FIQ, and TBUT and TO were higher in FM with high BDS. In FM patients, Schirmer test was correlated with the VAS (r = -0.429, P = 0.001), BDS (r = -0.277, P = 0.044), and FIQ (r = -0.382, P = 0.005), and the TBUT was correlated with the VAS (r = -0.537, P < 0.001), BDS (r = -0.350, P = 0.010), and FIQ (r = -0.456, P = 0.001). In addition, TO was significantly correlated with the VAS (r = 0.681, P < 0.001), BDS (r = 0.661, P < 0.001), and FIQ (r = 0.842, P < 0.001). However, no significant correlation existed between the OSDI and the VAS, BDS, or FIQ. We have revealed an association between FM disease activity and dry eye severity. The consideration of this relation will be useful in the treatment of FM with deteriorated clinical status.

The impact of testosterone imbalance on depression and women's health.

PubMed

Rohr, Uwe D

2002-04-15

Women suffer more often from depression than males, indicating that hormones might be involved in the etiology of this disease. Low as well as high testosterone (T) levels are related to depression and well-being in women, T plasma levels correlate to depression in a parabolic curve: at about 0.4-0.6 ng/ml plasma free T a minimum of depression is detected. Lower levels are related to depression, osteoporosis, declining libido, dyspareunia and an increase in total body fat mass. Androgen levels in women decrease continuously to about 50% before menopause compared to a 20-year-old women. Androgen levels even decline 70% within 24 h when women undergo surgical removal of the ovaries. Conventional oral contraception or HRT cause a decline in androgens because of higher levels of SHBG. Hyperandrogenic states exist, like hirsutism, acne and polycystic ovary syndrome. Social research suggests high androgen levels cause aggressive behavior in men and women and as a consequence may cause depression. Higher androgen values are more pronounced at young ages and before and after delivery of a baby and might be responsible for the "baby blues". It was found that depression in pubertal girls correlated best with an increase in T levels in contrast to the common belief that "environmental factors" during the time of growing up might be responsible for emotional "up and downs". T replacement therapy might be useful in perimenopausal women suffering from hip obesity, also named gynoid obesity. Abdominal obesity in men and women is linked to type 2 diabetes and coronary heart diseases. Testosterone replacement therapy in hypoandrogenic postmenopausal women might not only protect against obesity but also reduce the risk of developing these diseases. Antiandrogenic progestins might be useful for women suffering from hyperandrogenic state in peri- and postmenopause. Individual dosing schemes balancing side effects and beneficial effects are absolutely necessary. Substantial interindividual variability in T plasma values exists, making it difficult to utilize them for diagnostic purposes. Therefore a "four-level-hormone classification scheme" was developed identifying when estradiol (E) and T levels are out of balance. (1) Low E-low T levels are correlated with osteoporosis, depression, and obesity; (2) high E-low T with obesity, decreased libido; (3) high T-low E levels with aggression, depression, increased libido, and substance abuse; (4) high E-high T with type II diabetes risk, breast cancer and cardiovascular risk. Testosterone delivery systems are needed where beneficial and negative effects can be balanced. Any woman diagnosed for osteoporosis should be questioned for symptoms of depression.

CCLasso: correlation inference for compositional data through Lasso.

PubMed

Fang, Huaying; Huang, Chengcheng; Zhao, Hongyu; Deng, Minghua

2015-10-01

Direct analysis of microbial communities in the environment and human body has become more convenient and reliable owing to the advancements of high-throughput sequencing techniques for 16S rRNA gene profiling. Inferring the correlation relationship among members of microbial communities is of fundamental importance for genomic survey study. Traditional Pearson correlation analysis treating the observed data as absolute abundances of the microbes may lead to spurious results because the data only represent relative abundances. Special care and appropriate methods are required prior to correlation analysis for these compositional data. In this article, we first discuss the correlation definition of latent variables for compositional data. We then propose a novel method called CCLasso based on least squares with [Formula: see text] penalty to infer the correlation network for latent variables of compositional data from metagenomic data. An effective alternating direction algorithm from augmented Lagrangian method is used to solve the optimization problem. The simulation results show that CCLasso outperforms existing methods, e.g. SparCC, in edge recovery for compositional data. It also compares well with SparCC in estimating correlation network of microbe species from the Human Microbiome Project. CCLasso is open source and freely available from https://github.com/huayingfang/CCLasso under GNU LGPL v3. dengmh@pku.edu.cn Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Satellite DNA and cytogenetic evolution: molecular aspects and implications for man. [Kangaroo rats

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

Hatch, F.T.; Mazrimas, J.

1977-02-28

Simple, highly reiterated DNA sequences, often observed in density gradients as satellite DNAs, exist in condensed heterochromatin. This material is predominantly located at chromosomal centromeres, occasionally at telomeres, or intercalated within arms; in a few species it occupies entire chromosome arms. Satellite DNAs are a highly variable component of the genome of most higher eukaryotes, but their functions have remained speculative. The genus of kangaroo rats (Dipodomys) exhibits remarkable interspecies variations in content of three satellite DNAs, consisting of simple sequences 3 to 10 base pairs long, and in species karyotypes. A broad range of diploid-DNA content is correlated withmore » satellite-DNA content. The latter is correlated positively with predominance of biarmed over uniarmed chromosomes (high fundamental number FN) and inversely with two anatomical indices (leg-bone-length ratios) of specialization for the jumping gait. Karyotypic variation is achieved via chromosomal rearrangements, e.g., Robertsonian fusion, C-band heteromorphism, and pericentric inversion. Environmental adaptation is achieved, in part, by reassortment of gene-linkage groups and regulatory controls as a result of the chromosomal rearrangements. The foregoing relationships led to the postulation that highly reiterated DNA sequences play a supragenic, global role in environmental adaptation and the evolution of new species.« less

Search for correlation between asteroid families and classes

NASA Technical Reports Server (NTRS)

Hansen, O.

1977-01-01

A correlation between membership in a dynamically defined asteroid family and membership in a given asteroid spectral class is sought. Examination of 10 families each with five or more classified members indicates a correlation for the 4 families whose existence is best established, and no correlation for the remaining 6 families. This conclusion supports the break-up hypothesis for the origin of some families, while not contradicting that hypothesis for any family.

The QAP weighted network analysis method and its application in international services trade

NASA Astrophysics Data System (ADS)

Xu, Helian; Cheng, Long

2016-04-01

Based on QAP (Quadratic Assignment Procedure) correlation and complex network theory, this paper puts forward a new method named QAP Weighted Network Analysis Method. The core idea of the method is to analyze influences among relations in a social or economic group by building a QAP weighted network of networks of relations. In the QAP weighted network, a node depicts a relation and an undirect edge exists between any pair of nodes if there is significant correlation between relations. As an application of the QAP weighted network, we study international services trade by using the QAP weighted network, in which nodes depict 10 kinds of services trade relations. After the analysis of international services trade by QAP weighted network, and by using distance indicators, hierarchy tree and minimum spanning tree, the conclusion shows that: Firstly, significant correlation exists in all services trade, and the development of any one service trade will stimulate the other nine. Secondly, as the economic globalization goes deeper, correlations in all services trade have been strengthened continually, and clustering effects exist in those services trade. Thirdly, transportation services trade, computer and information services trade and communication services trade have the most influence and are at the core in all services trade.

Block sparsity-based joint compressed sensing recovery of multi-channel ECG signals.

PubMed

Singh, Anurag; Dandapat, Samarendra

2017-04-01

In recent years, compressed sensing (CS) has emerged as an effective alternative to conventional wavelet based data compression techniques. This is due to its simple and energy-efficient data reduction procedure, which makes it suitable for resource-constrained wireless body area network (WBAN)-enabled electrocardiogram (ECG) telemonitoring applications. Both spatial and temporal correlations exist simultaneously in multi-channel ECG (MECG) signals. Exploitation of both types of correlations is very important in CS-based ECG telemonitoring systems for better performance. However, most of the existing CS-based works exploit either of the correlations, which results in a suboptimal performance. In this work, within a CS framework, the authors propose to exploit both types of correlations simultaneously using a sparse Bayesian learning-based approach. A spatiotemporal sparse model is employed for joint compression/reconstruction of MECG signals. Discrete wavelets transform domain block sparsity of MECG signals is exploited for simultaneous reconstruction of all the channels. Performance evaluations using Physikalisch-Technische Bundesanstalt MECG diagnostic database show a significant gain in the diagnostic reconstruction quality of the MECG signals compared with the state-of-the art techniques at reduced number of measurements. Low measurement requirement may lead to significant savings in the energy-cost of the existing CS-based WBAN systems.

Evidence for the innate immune response as a correlate of protection in human immunodeficiency virus (HIV)-1 highly exposed seronegative subjects (HESN)

PubMed Central

Tomescu, C; Abdulhaqq, S; Montaner, L J

2011-01-01

The description of highly exposed individuals who remain seronegative (HESN) despite repeated exposure to human immunodeficiency virus (HIV)-1 has heightened interest in identifying potential mechanisms of HIV-1 resistance. HIV-specific humoral and T cell-mediated responses have been identified routinely in HESN subjects, although it remains unknown if these responses are a definitive cause of protection or merely a marker for exposure. Approximately half of HESN lack any detectible HIV-specific adaptive immune responses, suggesting that other mechanisms of protection from HIV-1 infection also probably exist. In support of the innate immune response as a mechanism of resistance, increased natural killer (NK) cell activity has been correlated with protection from infection in several high-risk cohorts of HESN subjects, including intravenous drug users, HIV-1 discordant couples and perinatally exposed infants. Inheritance of protective NK KIR3DL1high and KIR3DS1 receptor alleles have also been observed to be over-represented in a high-risk cohort of HESN intravenous drug users and HESN partners of HIV-1-infected subjects. Other intrinsic mechanisms of innate immune protection correlated with resistance in HESN subjects include heightened dendritic cell responses and increased secretion of anti-viral factors such as β-chemokines, small anti-viral factors and defensins. This review will highlight the most current evidence in HESN subjects supporting the role of epithelial microenvironment and the innate immune system in sustaining resistance against HIV-1 infection. We will argue that as a front-line defence the innate immune response determines the threshold of infectivity that HIV-1 must overcome to establish a productive infection. PMID:21413945

HPV prevalence among women from Appalachia: results from the CARE project.

PubMed

Reiter, Paul L; Katz, Mira L; Ruffin, Mack T; Hade, Erinn M; DeGraffenreid, Cecilia R; Patel, Divya A; Paskett, Electra D; Unger, Elizabeth R

2013-01-01

Cervical cancer incidence and mortality rates are high among women from Appalachia, yet data do not exist on human papillomavirus (HPV) prevalence among these women. We examined the prevalence of genital HPV among Appalachian women and identified correlates of HPV detection. We report data from a case-control study conducted between January 2006 and December 2008 as part of the Community Awareness, Resources, and Education (CARE) Project. We examined HPV prevalence among 1116 women (278 women with abnormal Pap tests at study entry [cases], 838 women with normal Pap tests [controls]) from Appalachian Ohio. Analyses used multivariable logistic regression to identify correlates of HPV detection. The prevalence of HPV was 43.1% for any HPV type, 33.5% for high-risk HPV types, 23.4% for low-risk HPV types, and 12.5% for vaccine-preventable HPV types. Detection of any HPV type was more common among women who were ages 18-26 (OR = 2.09, 95% CI: 1.26-3.50), current smokers (OR = 1.86, 95% CI: 1.26-2.73), had at least five male sexual partners during their lifetime (OR = 2.28, 95% CI: 1.56-3.33), or had multiple male sexual partners during the last year (OR = 1.98, 95% CI: 1.25-3.14). Similar correlates were identified for detection of a high-risk HPV type. HPV was prevalent among Appalachian women, with many women having a high-risk HPV type detected. Results may help explain the high cervical cancer rates observed among Appalachian women and can help inform future cervical cancer prevention efforts in this geographic region.

Comparisons between Arabidopsis thaliana and Drosophila melanogaster in relation to Coding and Noncoding Sequence Length and Gene Expression

PubMed Central

Caldwell, Rachel; Lin, Yan-Xia; Zhang, Ren

2015-01-01

There is a continuing interest in the analysis of gene architecture and gene expression to determine the relationship that may exist. Advances in high-quality sequencing technologies and large-scale resource datasets have increased the understanding of relationships and cross-referencing of expression data to the large genome data. Although a negative correlation between expression level and gene (especially transcript) length has been generally accepted, there have been some conflicting results arising from the literature concerning the impacts of different regions of genes, and the underlying reason is not well understood. The research aims to apply quantile regression techniques for statistical analysis of coding and noncoding sequence length and gene expression data in the plant, Arabidopsis thaliana, and fruit fly, Drosophila melanogaster, to determine if a relationship exists and if there is any variation or similarities between these species. The quantile regression analysis found that the coding sequence length and gene expression correlations varied, and similarities emerged for the noncoding sequence length (5′ and 3′ UTRs) between animal and plant species. In conclusion, the information described in this study provides the basis for further exploration into gene regulation with regard to coding and noncoding sequence length. PMID:26114098

Emergent quasicrystals in strongly correlated systems

NASA Astrophysics Data System (ADS)

Sagi, Eran; Nussinov, Zohar

2016-07-01

Commensurability is of paramount importance in numerous strongly interacting electronic systems. In the fractional quantum Hall effect, a rich cascade of increasingly narrow plateaux appear at larger denominator filling fractions. Rich commensurate structures also emerge, at certain filling fractions, in high temperature superconductors and other electronic systems. A natural question concerns the character of these and other electronic systems at irrational filling fractions. Here we demonstrate that quasicrystalline structures naturally emerge in these situations, and trigger behaviors not typically expected of periodic systems. We first show that irrationally filled quantum Hall systems cross over into quasiperiodically ordered configuration in the thin-torus limit. Using known properties of quasicrystals, we argue that these states are unstable against the effects of disorder, in agreement with the existence of quantum Hall plateaux. We then study analogous physical situations in a system of cold Rydberg atoms placed on an optical lattice. Such an experimental setup is generally disorder free, and can therefore be used to detect the emergent quasicrystals we predict. We discuss similar situations in the Falicov-Kimball model, where known exact results can be used to establish quasicrystalline structures in one and two dimensions. We briefly speculate on possible relations between our theoretical findings and the existence of glassy dynamics and other features of strongly correlated electronic systems.

Laboratory correlation of soil swell potential : final report.

DOT National Transportation Integrated Search

1979-03-01

The objective of the study was to determine if a correlation exists between the Potential Volume Change Test and the Potential Vertical Rise Test as compared to the Third Cycle Expansion Pressure Test. In order to accomplish this objective, samples o...

Development of Interspecies Correlation Models for Petroleum Hydrocarbons

EPA Science Inventory

Estimating the consequences of petroleum products to water column organisms has commonly been hampered by limited acute toxicity data, which exists only for a relatively small number of test species. In this study, we developed petroleum-specific Interspecies Correlation Estimati...

A Swedish cross-cultural adaptation and validation of the Tinnitus Functional Index.

PubMed

Hoff, Maria; Kähäri, Kim

2017-04-01

The Tinnitus Functional Index (TFI) is a recent self-report instrument for tinnitus with potential advantages over other existing instruments, including a demonstrated high responsiveness. The objectives of this study were to translate and cross-culturally adapt the TFI into Swedish and to investigate its validity and reliability. The development of the Swedish version (TFI-SE) followed published guidelines on cross-cultural adaptation of health questionnaires. Validity and reliability was investigated by correlating responses on the TFI-SE with other tinnitus measures [Tinnitus Handicap Inventory (THI) and visual analogue scale (VAS)] and a scale measuring anxiety and depression (HADS). Consecutively recruited tinnitus patients (n = 100) from four Swedish clinics completed the questionnaires. The mean age of the sample was 51 years (SD =17). The internal consistency of the TFI-SE was good (α = 0.95) and the test-retest reliability was high (ICC =0.93). Our results supported the eight-factor structure proposed for the original TFI, and a high correlation between the TFI-SE and the THI (r = 0.8; p < 0.01) and lower correlations between the TFI-SE and the HADS-D (r = 0.60; p < 0.01) and HADS-A (r = 0.59; p < 0.01) confirmed satisfactory convergent and discriminant validity. We found that the Swedish translation and cross-cultural adaptation of the TFI is valid and reliable for use with adult tinnitus patients.

Does the presence of antagonist remaining teeth affect implant overdenture success? A systematic review.

PubMed

Ohkubo, C; Baek, K W

2010-04-01

Many patients who need implant overdentures are not completely edentulous; they still have antagonist natural teeth or implant fixed prostheses. In such cases, however, little is known about whether existing natural teeth affect the success of implant overdentures positively or act as a complicating factor. This systematic review attempts to clarify the correlation between existing remaining teeth and the survival/success rate of maxillary and mandibular implant overdentures. An assessment of available relevant articles published in English from 1990 to 2009 was performed using an online database and a manual search in libraries. Although the opposing natural dentition was not sufficiently described in the literature, 10 articles about the mandible and 10 articles about the maxilla were selected. As there was no controlled study on the natural teeth opposing implant overdentures, this review could not reach a clear conclusion. The review did reveal a remarkably high success/survival rate for mandibular implant overdentures; maxillary implant overdentures showed a lower rate. The presence of antagonist teeth hardly seems to be a risk factor for success for mandibular implant overdentures. For maxillary implant overdentures, the existence of antagonist teeth might act negatively for implant survival, but they are certainly not a contraindication. Although a few articles stated this relationship, we could not find an apparent correlation between the remaining antagonist teeth and the success of the implant overdentures. A detailed description of the opposing dentate status and results of randomized controlled clinical trials would be required to characterize this evidence-based implant overdenture treatment.

Correlation Between Existence of Reef Sharks with Abundance of Reef Fishes in South Waters of Morotai Island (North Moluccas)

NASA Astrophysics Data System (ADS)

Mukharror, Darmawan Ahmad; Tiara Baiti, Isnaini; Ichsan, Muhammad; Pridina, Niomi; Triutami, Sanny

2017-10-01

Despite increasing academic research citation on biology, abundance, and the behavior of the blacktip reef sharks, the influence of reef fish population on the density of reef sharks: Carcharhinus melanopterus and Triaenodon obesus population in its habitat were largely unassessed. This present study examined the correlation between abundance of reef fishes family/species with the population of reef sharks in Southern Waters of Morotai Island. The existence of reef sharks was measured with the Audible Stationary Count (ASC) methods and the abundance of reef fishes was surveyed using Underwater Visual Census (UVC) combined with Diver Operated Video (DOV) census. The coefficient of Determination (R2) was used to investigate the degree of relationships between sharks and the specific reef fishes species. The research from 8th April to 4th June 2015 showed the strong positive correlations between the existence of reef sharks with abundance of reef fishes. The correlation values between Carcharhinus melanopterus/Triaenodon obesus with Chaetodon auriga was 0.9405, blacktip/whitetip reef sharks versus Ctenochaetus striatus was 0.9146, and Carcharhinus melanopterus/Triaenodon obesus to Chaetodon kleinii was 0.8440. As the shark can be worth more alive for shark diving tourism than dead in a fish market, the abundance of these reef fishes was important as an early indication parameter of shark existence in South Water of Morotai Island. In the long term, this highlights the importance of reef fishes abundance management in Morotai Island’s Waters to enable the establishment of appropriate and effective reef sharks conservation.

A Method for Correlation of Gravestone Weathering and Air Quality (SO2), West Amidlands, UK

NASA Astrophysics Data System (ADS)

Carlson, Michael John

From the beginning of the Industrial Revolution through the environmental revolution of the 1970s Britain suffered the effects of poor air quality primarily from particulate matter and acid in the form of NOx and SO x compounds. Air quality stations across the region recorded SO 2 beginning in the 1960s however the direct measurement of air quality prior to 1960 is lacking and only anecdotal notations exist. Proxy records including lung tissue samples, particulates in sediments cores, lake acidification studies and gravestone weathering have all been used to reconstruct the history of air quality. A 120-year record of acid deposition reconstructed from lead-lettered marble gravestone weathering combined with SO2 measurements from the air monitoring network across the West Midlands, UK region beginning in the 1960s form the framework for this study. The study seeks to create a spatial and temporal correlation between the gravestone weathering and measured SO 2. Successful correlation of the dataset from 1960s to the 2000s would allow a paleo-air quality record to be generated from the 120-year record of gravestone weathering. Decadal gravestone weathering rates can be estimated by non-linear regression analysis of stone loss at individual cemeteries. Gravestone weathering rates are interpolated across the region through Empirical Bayesian Kriging (EBK) methods performed through ArcGISRTM and through a land use based approach based on digitized maps of land use. Both methods of interpolation allow for the direct correlation of gravestone weathering and measured SO2 to be made. Decadal scale correlations of gravestone weathering rates and measured SO2 are very weak and non-existent for both EBK and the land use based approach. Decadal results combined together on a larger scale for each respective method display a better visual correlation. However, the relative clustering of data at lower SO2 concentrations and the lack of data at higher SO2 concentrations make the confidence in the correlations made too weak to rely on. The relation between surrounding land use and gravestone weathering rates was very strong for the 1960s-1980s with diminishing correlations approaching the 2000s. Gravestone weathering of cemeteries is highly influenced by the amount of industrial sources of pollution within a 7km radius. Reduced correlation of land use and weathering beyond the 1980s is solid grounds for the success of environmental regulation and control put in place across the UK during later parts of the 20th century.

Exploring lag times between monthly atmospheric deposition and stream chemistry in Appalachian forests using cross-correlation

NASA Astrophysics Data System (ADS)

DeWalle, David R.; Boyer, Elizabeth W.; Buda, Anthony R.

2016-12-01

Forecasts of ecosystem changes due to variations in atmospheric emissions policies require a fundamental understanding of lag times between changes in chemical inputs and watershed response. Impacts of changes in atmospheric deposition in the United States have been documented using national and regional long-term environmental monitoring programs beginning several decades ago. Consequently, time series of weekly NADP atmospheric wet deposition and monthly EPA-Long Term Monitoring stream chemistry now exist for much of the Northeast which may provide insights into lag times. In this study of Appalachian forest basins, we estimated lag times for S, N and Cl by cross-correlating monthly data from four pairs of stream and deposition monitoring sites during the period from 1978 to 2012. A systems or impulse response function approach to cross-correlation was used to estimate lag times where the input deposition time series was pre-whitened using regression modeling and the stream response time series was filtered using the deposition regression model prior to cross-correlation. Cross-correlations for S were greatest at annual intervals over a relatively well-defined range of lags with the maximum correlations occurring at mean lags of 48 months. Chloride results were similar but more erratic with a mean lag of 57 months. Few high-correlation lags for N were indicated. Given the growing availability of atmospheric deposition and surface water chemistry monitoring data and our results for four Appalachian basins, further testing of cross-correlation as a method of estimating lag times on other basins appears justified.

A novel coefficient for detecting and quantifying asymmetry of California electricity market based on asymmetric detrended cross-correlation analysis

NASA Astrophysics Data System (ADS)

Wang, Fang

2016-06-01

In order to detect and quantify asymmetry of two time series, a novel cross-correlation coefficient is proposed based on recent asymmetric detrended cross-correlation analysis (A-DXA), which we called A-DXA coefficient. The A-DXA coefficient, as an important extension of DXA coefficient ρ D X A , contains two directional asymmetric cross-correlated indexes, describing upwards and downwards asymmetric cross-correlations, respectively. By using the information of directional covariance function of two time series and directional variance function of each series itself instead of power-law between the covariance function and time scale, the proposed A-DXA coefficient can well detect asymmetry between the two series no matter whether the cross-correlation is significant or not. By means of the proposed A-DXA coefficient conducted over the asymmetry for California electricity market, we found that the asymmetry between the prices and loads is not significant for daily average data in 1999 yr market (before electricity crisis) but extremely significant for those in 2000 yr market (during the crisis). To further uncover the difference of asymmetry between the years 1999 and 2000, a modified H statistic (MH) and ΔMH statistic are proposed. One of the present contributions is that the high MH values calculated for hourly data exist in majority months in 2000 market. Another important conclusion is that the cross-correlation with downwards dominates over the whole 1999 yr in contrast to the cross-correlation with upwards dominates over the 2000 yr.

Towards a Rational Model for the Triple Velocity Correlations of Turbulence

NASA Technical Reports Server (NTRS)

Younis, B. A.; Gatski, T. B.; Speziale, C. G.

1999-01-01

This paper presents a rational approach to modelling the triple velocity correlations that appear in the transport equations for the Reynolds stresses. All existing models of these correlations have largely been formulated on phenomenological grounds and are defective in one important aspect: they all neglect to allow for the dependence of these correlations on the local gradients of mean velocity. The mathematical necessity for this dependence will be demonstrated in the paper. The present contribution lies in the novel use of Group Representation Theory to determine the most general tensorial form of these correlations in terms of all the second- and third-order tensor quantities that appear in the exact equations that govern their evolution. The requisite representation did not exist in the literature and therefore had to be developed specifically for this purpose by Professor G. F. Smith. The outcome of this work is a mathematical framework for the construction of algebraic, explicit, and rational models for the triple velocity correlations that are theoretically consistent and include all the correct dependencies. Previous models are reviewed, and all are shown to be an incomplete subset of this new representation, even to lowest order.

Patients' and observers' perceptions of involvement differ. Validation study on inter-relating measures for shared decision making.

PubMed

Kasper, Jürgen; Heesen, Christoph; Köpke, Sascha; Fulcher, Gary; Geiger, Friedemann

2011-01-01

Patient involvement into medical decisions as conceived in the shared decision making method (SDM) is essential in evidence based medicine. However, it is not conclusively evident how best to define, realize and evaluate involvement to enable patients making informed choices. We aimed at investigating the ability of four measures to indicate patient involvement. While use and reporting of these instruments might imply wide overlap regarding the addressed constructs this assumption seems questionable with respect to the diversity of the perspectives from which the assessments are administered. The study investigated a nested cohort (N = 79) of a randomized trial evaluating a patient decision aid on immunotherapy for multiple sclerosis. Convergent validities were calculated between observer ratings of videotaped physician-patient consultations (OPTION) and patients' perceptions of the communication (Shared Decision Making Questionnaire, Control Preference Scale & Decisional Conflict Scale). OPTION reliability was high to excellent. Communication performance was low according to OPTION and high according to the three patient administered measures. No correlations were found between observer and patient judges, neither for means nor for single items. Patient report measures showed some moderate correlations. Existing SDM measures do not refer to a single construct. A gold standard is missing to decide whether any of these measures has the potential to indicate patient involvement. Pronounced heterogeneity of the underpinning constructs implies difficulties regarding the interpretation of existing evidence on the efficacy of SDM. Consideration of communication theory and basic definitions of SDM would recommend an inter-subjective focus of measurement. Controlled-Trials.com ISRCTN25267500.

Comparison of Body Composition Measurements Using a New Caliper, Two Established Calipers, Hydrostatic Weighing, and BodPod.

PubMed

Talbert, Erin E; Flynn, Michael G; Bell, Jeffrey W; Carrillo, Andres E; Dill, Marquita D; Christensen, Christiania N; Thompson, Colleen M

2009-01-01

(1) To compare the Lafayette Instruments (LI) skinfold caliper to the Lange (L) and Harpenden (H) calipers using a diverse subject population. (2) To determine the validity of the LI caliper in a subset of subjects by comparing body compositions from skinfold thicknesses to those measured by hydrostatic weighing (HW) and air displacement plethysmography (ADP). (3) To compare measurements obtained by experienced (EX) and inexperienced (IX) technicians using all three calipers. Skinfold measurements were performed by both EX and IX technicians using three different calipers on 21 younger (21.2 ± 1.5 yrs) and 20 older (59.2 ± 4 yrs) subjects. Body compositions were calculated using the Jackson-Pollock seven-site and three-site formulas. HW and ADP tests were performed on a subset of subjects (10 younger, 10 older). No significant differences existed between LI and L or H when measurements were made by EX. Further, the LI-EX measurements were highly correlated to both H-EX and L-EX. No significant differences existed in the subgroup between LI-EX and HW or ADP. Skinfold determinations made by EX and IX were similar. Similar body compositions determined using LI, H, and L suggest that LI determines body composition as effectively as H and L. High correlations between the three calipers support this notion. Similar results between LI and HW/ADP subgroup suggest that the LI caliper may be a valid method of measuring body composition. Overall, performance by IX was similar to EX and suggests similar ease of use for all three calipers.

Comparison of Body Composition Measurements Using a New Caliper, Two Established Calipers, Hydrostatic Weighing, and BodPod

PubMed Central

TALBERT, ERIN E.; FLYNN, MICHAEL G.; BELL, JEFFREY W.; CARRILLO, ANDRES E.; DILL, MARQUITA D.; CHRISTENSEN, CHRISTIANIA N.; THOMPSON, COLLEEN M.

2009-01-01

Purposes (1) To compare the Lafayette Instruments (LI) skinfold caliper to the Lange (L) and Harpenden (H) calipers using a diverse subject population. (2) To determine the validity of the LI caliper in a subset of subjects by comparing body compositions from skinfold thicknesses to those measured by hydrostatic weighing (HW) and air displacement plethysmography (ADP). (3) To compare measurements obtained by experienced (EX) and inexperienced (IX) technicians using all three calipers. Methods Skinfold measurements were performed by both EX and IX technicians using three different calipers on 21 younger (21.2 ± 1.5 yrs) and 20 older (59.2 ± 4 yrs) subjects. Body compositions were calculated using the Jackson-Pollock seven-site and three-site formulas. HW and ADP tests were performed on a subset of subjects (10 younger, 10 older). Results No significant differences existed between LI and L or H when measurements were made by EX. Further, the LI-EX measurements were highly correlated to both H-EX and L-EX. No significant differences existed in the subgroup between LI-EX and HW or ADP. Skinfold determinations made by EX and IX were similar. Conclusions Similar body compositions determined using LI, H, and L suggest that LI determines body composition as effectively as H and L. High correlations between the three calipers support this notion. Similar results between LI and HW/ADP subgroup suggest that the LI caliper may be a valid method of measuring body composition. Overall, performance by IX was similar to EX and suggests similar ease of use for all three calipers. PMID:28572871

Correlation of FCGRT genomic structure with serum immunoglobulin, albumin and farletuzumab pharmacokinetics in patients with first relapsed ovarian cancer.

PubMed

O'Shannessy, Daniel J; Bendas, Katie; Schweizer, Charles; Wang, Wenquan; Albone, Earl; Somers, Elizabeth B; Weil, Susan; Meredith, Rhonda K; Wustner, Jason; Grasso, Luigi; Landers, Mark; Nicolaides, Nicholas C

2017-07-01

Farletuzumab (FAR) is a humanized monoclonal antibody (mAb) that binds to folate receptor alpha. A Ph3 trial in ovarian cancer patients treated with carboplatin/taxane plus FAR or placebo did not meet the primary statistical endpoint. Subgroup analysis demonstrated that subjects with high FAR exposure levels (Cmin>57.6μg/mL) showed statistically significant improvements in PFS and OS. The neonatal Fc receptor (fcgrt) plays a central role in albumin/IgG stasis and mAb pharmacokinetics (PK). Here we evaluated fcgrt sequence and association of its promoter variable number tandem repeats (VNTR) and coding single nucleotide variants (SNV) with albumin/IgG levels and FAR PK in the Ph3 patients. A statistical correlation existed between high FAR Cmin and AUC in patients with the highest quartile of albumin and lowest quartile of IgG1. Analysis of fcgrt identified 5 different VNTRs in the promoter region and 9 SNVs within the coding region, 4 which are novel. Copyright © 2017. Published by Elsevier Inc.

Concentrations of oligomers and polymers of proanthocyanidins in red and purple rice bran and their relationships to total phenolics, flavonoids, antioxidant capacity and whole grain color.

PubMed

Chen, Ming-Hsuan; McClung, Anna M; Bergman, Christine J

2016-10-01

Proanthocyanidins, a flavonoids subgroup, are proposed to have chronic disease modulation properties. With the eventual goal of enhancing rice phytonutrient concentrations, we investigated the genotypic variation of the concentrations of individual oligomers and polymers of proanthocyanidins in red and purple rice brans. A 4.3-fold variation in total proanthocyanidins (sum of oligomers and polymers) in the extractable fraction was found and the concentration was highly correlated with total phenolics, total flavonoids and antiradical capacity. Variation in the proportion of oligomers and polymers existed, with monomers to trimers, 4-6mers, 7-10mers and polymers accounting for 7, 18, 26.5 and 48.7%, respectively, of the total. The redness value a(∗) of whole grain rice measured in CIE L(∗)a(∗)b(∗) color space was negatively and positively correlated with extractable and non-extractable proanthocyanidins, respectively. The variation found indicates it is possible to select rice with bran containing high levels of total proanthocyanidins and specific degree of polymerization profiles. Published by Elsevier Ltd.

Recoil ions from the β decay of 134Sb confined in a Paul trap

NASA Astrophysics Data System (ADS)

Siegl, K.; Scielzo, N. D.; Czeszumska, A.; Clark, J. A.; Savard, G.; Aprahamian, A.; Caldwell, S. A.; Alan, B. S.; Burkey, M. T.; Chiara, C. J.; Greene, J. P.; Harker, J.; Marley, S. T.; Morgan, G. E.; Munson, J. M.; Norman, E. B.; Orford, R.; Padgett, S.; Galván, A. Perez; Sharma, K. S.; Strauss, S. Y.

2018-03-01

The low-energy recoiling ions from the β decay of 134Sb were studied by using the Beta-decay Paul Trap. Using this apparatus, singly charged ions were suspended in vacuum at the center of a detector array used to detect emitted β particles, γ rays, and recoil ions in coincidence. The recoil ions emerge from the trap with negligible scattering, allowing β -decay properties and the charge-state distribution of the daughter ions to be determined from the β -ion coincidences. First-forbidden β -decay theory predicts a β -ν correlation coefficient of nearly unity for the 0- to 0+ transition from the ground state of 134Sb to the ground state of 134Te. Although this transition was expected to have a nearly 100% branching ratio, an additional 17.2(52)% of the β -decay strength must populate high-lying excited states to obtain an angular correlation consistent with unity. The extracted charge-state distribution of the recoiling ions was compared with existing β -decay results and the average charge state was found to be consistent with the results from lighter nuclei.