WorldWideScience

Sample records for initio quality scoring

  1. Quality scores for 32,000 genomes

    DEFF Research Database (Denmark)

    Land, Miriam L.; Hyatt, Doug; Jun, Se-Ran

    2014-01-01

    Background More than 80% of the microbial genomes in GenBank are of ‘draft’ quality (12,553 draft vs. 2,679 finished, as of October, 2013). We have examined all the microbial DNA sequences available for complete, draft, and Sequence Read Archive genomes in GenBank as well as three other major...... public databases, and assigned quality scores for more than 30,000 prokaryotic genome sequences. Results Scores were assigned using four categories: the completeness of the assembly, the presence of full-length rRNA genes, tRNA composition and the presence of a set of 102 conserved genes in prokaryotes....... Most (~88%) of the genomes had quality scores of 0.8 or better and can be safely used for standard comparative genomics analysis. We compared genomes across factors that may influence the score. We found that although sequencing depth coverage of over 100x did not ensure a better score, sequencing read...

  2. dBBQs: dataBase of Bacterial Quality scores.

    Science.gov (United States)

    Wanchai, Visanu; Patumcharoenpol, Preecha; Nookaew, Intawat; Ussery, David

    2017-12-28

    It is well-known that genome sequencing technologies are becoming significantly cheaper and faster. As a result of this, the exponential growth in sequencing data in public databases allows us to explore ever growing large collections of genome sequences. However, it is less known that the majority of available sequenced genome sequences in public databases are not complete, drafts of varying qualities. We have calculated quality scores for around 100,000 bacterial genomes from all major genome repositories and put them in a fast and easy-to-use database. Prokaryotic genomic data from all sources were collected and combined to make a non-redundant set of bacterial genomes. The genome quality score for each was calculated by four different measurements: assembly quality, number of rRNA and tRNA genes, and the occurrence of conserved functional domains. The dataBase of Bacterial Quality scores (dBBQs) was designed to store and retrieve quality scores. It offers fast searching and download features which the result can be used for further analysis. In addition, the search results are shown in interactive JavaScript chart framework using DC.js. The analysis of quality scores across major public genome databases find that around 68% of the genomes are of acceptable quality for many uses. dBBQs (available at http://arc-gem.uams.edu/dbbqs ) provides genome quality scores for all available prokaryotic genome sequences with a user-friendly Web-interface. These scores can be used as cut-offs to get a high-quality set of genomes for testing bioinformatics tools or improving the analysis. Moreover, all data of the four measurements that were combined to make the quality score for each genome, which can potentially be used for further analysis. dBBQs will be updated regularly and is freely use for non-commercial purpose.

  3. A quality score for coronary artery tree extraction results

    Science.gov (United States)

    Cao, Qing; Broersen, Alexander; Kitslaar, Pieter H.; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

    2018-02-01

    Coronary artery trees (CATs) are often extracted to aid the fully automatic analysis of coronary artery disease on coronary computed tomography angiography (CCTA) images. Automatically extracted CATs often miss some arteries or include wrong extractions which require manual corrections before performing successive steps. For analyzing a large number of datasets, a manual quality check of the extraction results is time-consuming. This paper presents a method to automatically calculate quality scores for extracted CATs in terms of clinical significance of the extracted arteries and the completeness of the extracted CAT. Both right dominant (RD) and left dominant (LD) anatomical statistical models are generated and exploited in developing the quality score. To automatically determine which model should be used, a dominance type detection method is also designed. Experiments are performed on the automatically extracted and manually refined CATs from 42 datasets to evaluate the proposed quality score. In 39 (92.9%) cases, the proposed method is able to measure the quality of the manually refined CATs with higher scores than the automatically extracted CATs. In a 100-point scale system, the average scores for automatically and manually refined CATs are 82.0 (+/-15.8) and 88.9 (+/-5.4) respectively. The proposed quality score will assist the automatic processing of the CAT extractions for large cohorts which contain both RD and LD cases. To the best of our knowledge, this is the first time that a general quality score for an extracted CAT is presented.

  4. ITC Guidelines on Quality Control in Scoring, Test Analysis, and Reporting of Test Scores

    Science.gov (United States)

    Allalouf, Avi

    2014-01-01

    The Quality Control (QC) Guidelines are intended to increase the efficiency, precision, and accuracy of the scoring, analysis, and reporting process of testing. The QC Guidelines focus on large-scale testing operations where multiple forms of tests are created for use on set dates. However, they may also be used for a wide variety of other testing…

  5. dBBQs: dataBase of Bacterial Quality scores

    OpenAIRE

    Wanchai, Visanu; Patumcharoenpol, Preecha; Nookaew, Intawat; Ussery, David

    2017-01-01

    Background: It is well-known that genome sequencing technologies are becoming significantly cheaper and faster. As a result of this, the exponential growth in sequencing data in public databases allows us to explore ever growing large collections of genome sequences. However, it is less known that the majority of available sequenced genome sequences in public databases are not complete, drafts of varying qualities. We have calculated quality scores for around 100,000 bacterial genomes from al...

  6. Lossy compression of quality scores in genomic data.

    Science.gov (United States)

    Cánovas, Rodrigo; Moffat, Alistair; Turpin, Andrew

    2014-08-01

    Next-generation sequencing technologies are revolutionizing medicine. Data from sequencing technologies are typically represented as a string of bases, an associated sequence of per-base quality scores and other metadata, and in aggregate can require a large amount of space. The quality scores show how accurate the bases are with respect to the sequencing process, that is, how confident the sequencer is of having called them correctly, and are the largest component in datasets in which they are retained. Previous research has examined how to store sequences of bases effectively; here we add to that knowledge by examining methods for compressing quality scores. The quality values originate in a continuous domain, and so if a fidelity criterion is introduced, it is possible to introduce flexibility in the way these values are represented, allowing lossy compression over the quality score data. We present existing compression options for quality score data, and then introduce two new lossy techniques. Experiments measuring the trade-off between compression ratio and information loss are reported, including quantifying the effect of lossy representations on a downstream application that carries out single nucleotide polymorphism and insert/deletion detection. The new methods are demonstrably superior to other techniques when assessed against the spectrum of possible trade-offs between storage required and fidelity of representation. An implementation of the methods described here is available at https://github.com/rcanovas/libCSAM. rcanovas@student.unimelb.edu.au Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Automatic ECG quality scoring methodology: mimicking human annotators

    International Nuclear Information System (INIS)

    Johannesen, Lars; Galeotti, Loriano

    2012-01-01

    An algorithm to determine the quality of electrocardiograms (ECGs) can enable inexperienced nurses and paramedics to record ECGs of sufficient diagnostic quality. Previously, we proposed an algorithm for determining if ECG recordings are of acceptable quality, which was entered in the PhysioNet Challenge 2011. In the present work, we propose an improved two-step algorithm, which first rejects ECGs with macroscopic errors (signal absent, large voltage shifts or saturation) and subsequently quantifies the noise (baseline, powerline or muscular noise) on a continuous scale. The performance of the improved algorithm was evaluated using the PhysioNet Challenge database (1500 ECGs rated by humans for signal quality). We achieved a classification accuracy of 92.3% on the training set and 90.0% on the test set. The improved algorithm is capable of detecting ECGs with macroscopic errors and giving the user a score of the overall quality. This allows the user to assess the degree of noise and decide if it is acceptable depending on the purpose of the recording. (paper)

  8. High Framingham risk score decreases quality of life in adults

    Directory of Open Access Journals (Sweden)

    Christian Yosaputra

    2010-04-01

    Full Text Available Cardiovascular disease (CVD risk factors, such as diabetes, hypertension, hypercholesterolemia, smoking, and obesity tend to occur together in the general population. Increasing prevalence of multiple CVD risk factors has been related to increased risk of death from coronary heart disease and stroke. Studies have suggested that people with several risk factors of CVD may have impaired health-related quality of life. The objective of this study was to assess the association of CVD risk factors with quality of life (QOL among adults aged 40 to 65 years. A cross-sectional study was conducted involving 220 subjects 40 - 65 years of age at a health center. The CVD risk factors were assessed using the Framingham risk score that is the standard instrument for assessment of the risk of a first cardiac event. The risk factors assessed were age, smoking, blood pressure, total cholesterol and high density lipoprotein cholesterol concentrations. QOL was assessed by means of the WHOQOL-BREF instrument that had been prevalidated. The results of the study showed that 28.2% of subjects were smokers, 56.4% had stage 1 hypertension, 42.8% high total cholesterol and 13.6% low HDL cholesterol. The high risk group amounted to 45.5% and 42.3% constitued an intermediate risk group. High CVD risk scores were significantly associated with a low QOL for all domains (physical, psychological, social and environment (p=0.000. Preventing or reducing the multiple CVD risk factors to improve QOL is necessary among adults.

  9. ReQON: a Bioconductor package for recalibrating quality scores from next-generation sequencing data

    Directory of Open Access Journals (Sweden)

    Cabanski Christopher R

    2012-09-01

    Full Text Available Abstract Background Next-generation sequencing technologies have become important tools for genome-wide studies. However, the quality scores that are assigned to each base have been shown to be inaccurate. If the quality scores are used in downstream analyses, these inaccuracies can have a significant impact on the results. Results Here we present ReQON, a tool that recalibrates the base quality scores from an input BAM file of aligned sequencing data using logistic regression. ReQON also generates diagnostic plots showing the effectiveness of the recalibration. We show that ReQON produces quality scores that are both more accurate, in the sense that they more closely correspond to the probability of a sequencing error, and do a better job of discriminating between sequencing errors and non-errors than the original quality scores. We also compare ReQON to other available recalibration tools and show that ReQON is less biased and performs favorably in terms of quality score accuracy. Conclusion ReQON is an open source software package, written in R and available through Bioconductor, for recalibrating base quality scores for next-generation sequencing data. ReQON produces a new BAM file with more accurate quality scores, which can improve the results of downstream analysis, and produces several diagnostic plots showing the effectiveness of the recalibration.

  10. Optimizing Scoring and Sampling Methods for Assessing Built Neighborhood Environment Quality in Residential Areas

    Science.gov (United States)

    Adu-Brimpong, Joel; Coffey, Nathan; Ayers, Colby; Berrigan, David; Yingling, Leah R.; Thomas, Samantha; Mitchell, Valerie; Ahuja, Chaarushi; Rivers, Joshua; Hartz, Jacob; Powell-Wiley, Tiffany M.

    2017-01-01

    Optimization of existing measurement tools is necessary to explore links between aspects of the neighborhood built environment and health behaviors or outcomes. We evaluate a scoring method for virtual neighborhood audits utilizing the Active Neighborhood Checklist (the Checklist), a neighborhood audit measure, and assess street segment representativeness in low-income neighborhoods. Eighty-two home neighborhoods of Washington, D.C. Cardiovascular Health/Needs Assessment (NCT01927783) participants were audited using Google Street View imagery and the Checklist (five sections with 89 total questions). Twelve street segments per home address were assessed for (1) Land-Use Type; (2) Public Transportation Availability; (3) Street Characteristics; (4) Environment Quality and (5) Sidewalks/Walking/Biking features. Checklist items were scored 0–2 points/question. A combinations algorithm was developed to assess street segments’ representativeness. Spearman correlations were calculated between built environment quality scores and Walk Score®, a validated neighborhood walkability measure. Street segment quality scores ranged 10–47 (Mean = 29.4 ± 6.9) and overall neighborhood quality scores, 172–475 (Mean = 352.3 ± 63.6). Walk scores® ranged 0–91 (Mean = 46.7 ± 26.3). Street segment combinations’ correlation coefficients ranged 0.75–1.0. Significant positive correlations were found between overall neighborhood quality scores, four of the five Checklist subsection scores, and Walk Scores® (r = 0.62, p health behaviors and outcomes. PMID:28282878

  11. Which clinical variable influences health-related quality of life the most after spontaneous subarachnoid hemorrhage? Hunt and Hess scale, Fisher score, World Federation of Neurosurgeons score, Brussels coma score, and Glasgow coma score compared.

    Science.gov (United States)

    Kapapa, Thomas; Tjahjadi, Martin; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

    2013-12-01

    To determine the strength of the correlation between the Hunt and Hess scale, Fisher score, Brussels coma score, World Federation of Neurosurgeons score, and Glasgow coma score and health-related quality of life. Evaluable questionnaires from 236 patients (5.6 years [± standard deviation, 2.854 years] on average after hemorrhage) were included in the analysis. Quality of life was documented using the MOS-36 item short form health survey. Because of the ordinal nature of the variables, Kendall tau was used for calculation. Significance was established as P ≤ 0.05. Weak and very weak correlations were found in general (r ≤ 0.28). The strongest correlations were found between the Glasgow coma score and quality of life (r = 0.236, P = 0.0001). In particular, the "best verbal response" achieved the strongest correlations in the comparison, at r = 0.28/P = 0.0001. The Fisher score showed very weak correlations (r = -0.148/P = 0.012). The Brussels coma score (r = -0.216/P = 0.0001), Hunt and Hess scale (r = -0.197/P = 0.0001), and the World Federation of Neurosurgeons score (r = -0.185/P = 0.0001) revealed stronger correlations, especially in terms of the physical aspects of quality of life. The Glasgow coma scale revealed the strongest, and the Fisher score showed the weakest correlations. Thus the Fisher score, as an indicator of the severity of a hemorrhage, has little significance in terms of health-related quality of life. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Diet Quality Scores of Australian Adults Who Have Completed the Healthy Eating Quiz.

    Science.gov (United States)

    Williams, Rebecca L; Rollo, Megan E; Schumacher, Tracy; Collins, Clare E

    2017-08-15

    Higher scores obtained using diet quality and variety indices are indicators of more optimal food and nutrient intakes and lower chronic disease risk. The aim of this paper is to describe the overall diet quality and variety in a sample of Australian adults who completed an online diet quality self-assessment tool, the Healthy Eating Quiz. The Healthy Eating Quiz takes approximately five minutes to complete online and computes user responses into a total diet quality score (out of a maximum of 73 points) and then categorizes them into the following groups: 'needs work' (Healthy eating quiz scores were higher in those aged 45-75 years compared to 16-44 years ( p Healthy Eating Quiz data indicates that individuals receiving feedback on how to improve their score can improve their diet quality, there is a need for further nutrition promotion interventions in Australian adults.

  13. Have Nursing Home Compare quality measure scores changed over time in response to competition?

    Science.gov (United States)

    Castle, Nicholas G; Engberg, John; Liu, Darren

    2007-06-01

    Currently, the Centers for Medicare and Medicaid Services report on 15 Quality Measures (QMs) on the Nursing Home Compare (NHC) website. It is assumed that nursing homes are able to make improvements on these QMs, and in doing so they will attract more residents. In this investigation, we examine changes in QM scores, and whether competition and/or excess demand have influenced these change scores over a period of 1 year. Data come from NHC and the On-line Survey Certification And Recording (OSCAR) system. QM change scores are calculated using values from January 2003 to January 2004. A series of regression analyses are used to examine the association of competition and excess demand on QM scores. Eight QMs show an average decrease in scores (ie, better quality) and six QMs show an average increase in scores (ie, worse quality). However, for 13 of the 14 QMs these average changes averaged less than 1%. The regression analyses show an association between higher competition and improving QM scores and an association between lower occupancy and improving QM scores. As would be predicted based on the market-driven mechanism underlying quality improvements using report cards, we show that it is in the most competitive markets and those with the lowest average occupancy rates that improvements in the QM scores are more likely.

  14. Optimizing Scoring and Sampling Methods for Assessing Built Neighborhood Environment Quality in Residential Areas

    Directory of Open Access Journals (Sweden)

    Joel Adu-Brimpong

    2017-03-01

    Full Text Available Optimization of existing measurement tools is necessary to explore links between aspects of the neighborhood built environment and health behaviors or outcomes. We evaluate a scoring method for virtual neighborhood audits utilizing the Active Neighborhood Checklist (the Checklist, a neighborhood audit measure, and assess street segment representativeness in low-income neighborhoods. Eighty-two home neighborhoods of Washington, D.C. Cardiovascular Health/Needs Assessment (NCT01927783 participants were audited using Google Street View imagery and the Checklist (five sections with 89 total questions. Twelve street segments per home address were assessed for (1 Land-Use Type; (2 Public Transportation Availability; (3 Street Characteristics; (4 Environment Quality and (5 Sidewalks/Walking/Biking features. Checklist items were scored 0–2 points/question. A combinations algorithm was developed to assess street segments’ representativeness. Spearman correlations were calculated between built environment quality scores and Walk Score®, a validated neighborhood walkability measure. Street segment quality scores ranged 10–47 (Mean = 29.4 ± 6.9 and overall neighborhood quality scores, 172–475 (Mean = 352.3 ± 63.6. Walk scores® ranged 0–91 (Mean = 46.7 ± 26.3. Street segment combinations’ correlation coefficients ranged 0.75–1.0. Significant positive correlations were found between overall neighborhood quality scores, four of the five Checklist subsection scores, and Walk Scores® (r = 0.62, p < 0.001. This scoring method adequately captures neighborhood features in low-income, residential areas and may aid in delineating impact of specific built environment features on health behaviors and outcomes.

  15. Effect of mandibular advancement device on sleep bruxism score and sleep quality.

    Science.gov (United States)

    Solanki, Nehal; Singh, Balendra Pratap; Chand, Pooran; Siddharth, Ramashankar; Arya, Deeksha; Kumar, Lakshya; Tripathi, Suryakant; Jivanani, Hemant; Dubey, Abhishek

    2017-01-01

    The use of mandibular advancement devices (MADs) in the treatment of sleep bruxism is gaining widespread importance. However, the effects of MADs on sleep bruxism scores, sleep quality, and occlusal force are not clear. The purpose of this clinical study was to analyze the effect of MADs on sleep bruxism scores, sleep quality, and occlusal force. This uncontrolled before and after study enrolled 30 participants with sleep bruxism. Outcomes assessed were sleep quality, sleep bruxism scores (sleep bruxism bursts and sleep bruxism episodes/hour), and occlusal force before and after 15 and 30 days of using a MAD. Sleep bruxism scores were assessed by ambulatory polysomnography and sleep quality by using the Pittsburgh sleep quality index (PSQI). Occlusal force was recorded by using a digital gnathodynamometer in the first molar region on both sides. Statistical analysis was done by 1-factor repeated measures ANOVA (α=.05). Statistically significant reductions in sleep bruxism bursts/h, sleep bruxism episodes/h, and PSQI scores were found after 15 and 30 days of using a MAD (Pbruxism scores, sleep quality, and reduction in occlusal force in sleep bruxism participants after using MADs. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  16. A glance at quality score: implication for de novo transcriptome reconstruction of Illumina reads

    Directory of Open Access Journals (Sweden)

    Stanley Kimbung Mbandi

    2014-02-01

    Full Text Available Downstream analyses of short-reads from next-generation sequencing platforms are often preceded by a pre-processing step that removes uncalled and wrongly called bases. Standard approaches rely on their associated base quality scores to retain the read or a portion of it when the score is above a predefined threshold. It is difficult to differentiate sequencing error from biological variation without a reference using quality scores. The effects of quality score based trimming have not been systematically studied in de novo transcriptome assembly. Using RNA-Seq data produced from Illumina, we teased out the effects of quality score base filtering or trimming on de novo transcriptome reconstruction. We showed that assemblies produced from reads subjected to different quality score thresholds contain truncated and missing transfrags when compared to those from untrimmed reads. Our data supports the fact that de novo assembling of untrimmed data is challenging for de Bruijn graph assemblers. However, our results indicates that comparing the assemblies from untrimmed and trimmed read subsets can suggest appropriate filtering parameters and enable selection of the optimum de novo transcriptome assembly in non-model organisms.

  17. First quality score for referral letters in gastroenterology—a validation study

    Science.gov (United States)

    Eskeland, Sigrun Losada; Brunborg, Cathrine; Seip, Birgitte; Wiencke, Kristine; Hovde, Øistein; Owen, Tanja; Skogestad, Erik; Huppertz-Hauss, Gert; Halvorsen, Fred-Arne; Garborg, Kjetil; Aabakken, Lars; de Lange, Thomas

    2016-01-01

    Objective To create and validate an objective and reliable score to assess referral quality in gastroenterology. Design An observational multicentre study. Setting and participants 25 gastroenterologists participated in selecting variables for a Thirty Point Score (TPS) for quality assessment of referrals to gastroenterology specialist healthcare for 9 common indications. From May to September 2014, 7 hospitals from the South-Eastern Norway Regional Health Authority participated in collecting and scoring 327 referrals to a gastroenterologist. Main outcome measure Correlation between the TPS and a visual analogue scale (VAS) for referral quality. Results The 327 referrals had an average TPS of 13.2 (range 1–25) and an average VAS of 4.7 (range 0.2–9.5). The reliability of the score was excellent, with an intra-rater intraclass correlation coefficient (ICC) of 0.87 and inter-rater ICC of 0.91. The overall correlation between the TPS and the VAS was moderate (r=0.42), and ranged from fair to substantial for the various indications. Mean agreement was good (ICC=0.47, 95% CI (0.34 to 0.57)), ranging from poor to good. Conclusions The TPS is reliable, objective and shows good agreement with the subjective VAS. The score may be a useful tool for assessing referral quality in gastroenterology, particularly important when evaluating the effect of interventions to improve referral quality. PMID:27855107

  18. Highlighting ethical decisions underlying the scoring of animal welfare in the Welfare Quality® scheme

    DEFF Research Database (Denmark)

    Veissier, I.; Jensen, Karsten Klint; Botreau, R.

    2011-01-01

    dimension of scoring and labelling does not mean that we should reject them, but it does mean that we need to make the normative and ethical background explicit. The Welfare Quality® scoring system is used as a case study in order to highlight the role of underlying value-based decisions. In this scoring......, but the rules governing the assignment of an animal unit to a category take into account what had been observed on European farms. The scientists behind Welfare Quality® are keen to make the value-based choices underlying assessments of animal welfare transparent. This is essential to allow stakeholder groups......All systems of scoring animal units (groups, farms, slaughter plants, etc.) according to the level of the animals’ welfare are based inevitably on normative decisions. Similarly, all methods of labelling, in terms of acceptability, are based on choices reflecting ethical values. The evaluative...

  19. Ossification score is a better indicator of maturity related changes in eating quality than animal age.

    Science.gov (United States)

    Bonny, S P F; Pethick, D W; Legrand, I; Wierzbicki, J; Allen, P; Farmer, L J; Polkinghorne, R J; Hocquette, J-F; Gardner, G E

    2016-04-01

    Ossification score and animal age are both used as proxies for maturity-related collagen crosslinking and consequently decreases in beef tenderness. Ossification score is strongly influenced by the hormonal status of the animal and may therefore better reflect physiological maturity and consequently eating quality. As part of a broader cross-European study, local consumers scored 18 different muscle types cooked in three ways from 482 carcasses with ages ranging from 590 to 6135 days and ossification scores ranging from 110 to 590. The data were studied across three different maturity ranges; the complete range of maturities, a lesser range and a more mature range. The lesser maturity group consisted of carcasses having either an ossification score of 200 or less or an age of 987 days or less with the remainder in the greater maturity group. The three different maturity ranges were analysed separately with a linear mixed effects model. Across all the data, and for the greater maturity group, animal age had a greater magnitude of effect on eating quality than ossification score. This is likely due to a loss of sensitivity in mature carcasses where ossification approached and even reached the maximum value. In contrast, age had no relationship with eating quality for the lesser maturity group, leaving ossification score as the more appropriate measure. Therefore ossification score is more appropriate for most commercial beef carcasses, however it is inadequate for carcasses with greater maturity such as cull cows. Both measures may therefore be required in models to predict eating quality over populations with a wide range in maturity.

  20. Interpreting Quality of Life after Brain Injury Scores: Cross-Walk with the Short Form-36.

    Science.gov (United States)

    Wilson, Lindsay; Marsden-Loftus, Isaac; Koskinen, Sanna; Bakx, Wilbert; Bullinger, Monika; Formisano, Rita; Maas, Andrew; Neugebauer, Edmund; Powell, Jane; Sarajuuri, Jaana; Sasse, Nadine; von Steinbuechel, Nicole; von Wild, Klaus; Truelle, Jean-Luc

    2017-01-01

    The Quality of Life after Brain Injury (QOLIBRI) instruments are traumatic brain injury (TBI)-specific assessments of health-related quality of life (HRQoL), with established validity and reliability. The purpose of the study is to help improve the interpretability of the two QOLIBRI summary scores (the QOLIBRI Total score and the QOLBRI Overall Scale [OS] score). An analysis was conducted of 761 patients with TBI who took part in the QOLIBRI validation studies. A cross-walk between QOLIBRI scores and the SF-36 Mental Component Summary norm-based scoring system was performed using geometric mean regression analysis. The exercise supports a previous suggestion that QOLIBRI Total scores GOSE), as a measure of global function, are presented in the form of means and standard deviations that allow comparison with other studies, and data on age and sex are presented for the QOLIBRI-OS. While bearing in mind the potential imprecision of the comparison, the findings provide a framework for evaluating QOLIBRI summary scores in relation to generic HRQoL that improves their interpretability.

  1. Data from frequency-volume charts versus symptom scores and quality of life score in men with lower urinary tract symptoms due to benign prostatic hyperplasia

    NARCIS (Netherlands)

    van Venrooij, GEPM; Eckhardt, MD; Gisolf, KWH; Boon, TA

    Objective: The aim is to study the relations between reported data on frequency-volume charts and the American Urological Association (AUA) symptom scores and quality of life score. Methods: Males with lower urinary tract symptoms due to benign prostatic hyperplasia (BPH), were consecutively

  2. Communication: A benchmark-quality, full-dimensional ab initio potential energy surface for Ar-HOCO

    International Nuclear Information System (INIS)

    Conte, Riccardo; Bowman, Joel M.; Houston, Paul L.

    2014-01-01

    A full-dimensional, global ab initio potential energy surface (PES) for the Ar-HOCO system is presented. The PES consists of a previous intramolecular ab initio PES for HOCO [J. Li, C. Xie, J. Ma, Y. Wang, R. Dawes, D. Xie, J. M. Bowman, and H. Guo, J. Phys. Chem. A 116, 5057 (2012)], plus a new permutationally invariant interaction potential based on fitting 12 432 UCCSD(T)-F12a/aVDZ counterpoise-corrected energies. The latter has a total rms fitting error of about 25 cm −1 for fitted interaction energies up to roughly 12 000 cm −1 . Two additional fits are presented. One is a novel very compact permutational invariant representation, which contains terms only involving the Ar-atom distances. The rms fitting error for this fit is 193 cm −1 . The other fit is the widely used pairwise one. The pairwise fit to the entire data set has an rms fitting error of 427 cm −1 . All of these potentials are used in preliminary classical trajectory calculations of energy transfer with a focus on comparisons with the results using the benchmark potential

  3. Communication: A benchmark-quality, full-dimensional ab initio potential energy surface for Ar-HOCO

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Riccardo, E-mail: riccardo.conte@emory.edu, E-mail: jmbowma@emory.edu; Bowman, Joel M., E-mail: riccardo.conte@emory.edu, E-mail: jmbowma@emory.edu [Department of Chemistry and Cherry L. Emerson Center for Scientific Calculation, Emory University, Atlanta, Georgia 30322 (United States); Houston, Paul L., E-mail: paul.houston@cos.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2014-04-21

    A full-dimensional, global ab initio potential energy surface (PES) for the Ar-HOCO system is presented. The PES consists of a previous intramolecular ab initio PES for HOCO [J. Li, C. Xie, J. Ma, Y. Wang, R. Dawes, D. Xie, J. M. Bowman, and H. Guo, J. Phys. Chem. A 116, 5057 (2012)], plus a new permutationally invariant interaction potential based on fitting 12 432 UCCSD(T)-F12a/aVDZ counterpoise-corrected energies. The latter has a total rms fitting error of about 25 cm{sup −1} for fitted interaction energies up to roughly 12 000 cm{sup −1}. Two additional fits are presented. One is a novel very compact permutational invariant representation, which contains terms only involving the Ar-atom distances. The rms fitting error for this fit is 193 cm{sup −1}. The other fit is the widely used pairwise one. The pairwise fit to the entire data set has an rms fitting error of 427 cm{sup −1}. All of these potentials are used in preliminary classical trajectory calculations of energy transfer with a focus on comparisons with the results using the benchmark potential.

  4. Plasma ascorbic acid, a priori diet quality score, and incident hypertension

    NARCIS (Netherlands)

    Buijsse, Brian; Jacobs, D.R.; Steffen, L.M.; Kromhout, Daan; Gross, M.D.

    2015-01-01

    Vitamin C may reduce risk of hypertension, either in itself or by marking a healthy diet pattern. We assessed whether plasma ascorbic acid and the a priori diet quality score relate to incident hypertension and whether they explain each other's predictive abilities. Data were from 2884 black and

  5. Reliability and Validity of SERVQUAL Scores Used To Evaluate Perceptions of Library Service Quality.

    Science.gov (United States)

    Thompson, Bruce; Cook, Colleen

    Research libraries are increasingly supplementing collection counts with perceptions of service quality as indices of status and productivity. The present study was undertaken to explore the reliability and validity of scores from the SERVQUAL measurement protocol (A. Parasuraman and others, 1991), which has previously been used in this type of…

  6. Quality Evaluation Scores are no more Reliable than Gestalt in Evaluating the Quality of Emergency Medicine Blogs: A METRIQ Study.

    Science.gov (United States)

    Thoma, Brent; Sebok-Syer, Stefanie S; Colmers-Gray, Isabelle; Sherbino, Jonathan; Ankel, Felix; Trueger, N Seth; Grock, Andrew; Siemens, Marshall; Paddock, Michael; Purdy, Eve; Kenneth Milne, William; Chan, Teresa M

    2018-01-30

    Construct: We investigated the quality of emergency medicine (EM) blogs as educational resources. Online medical education resources such as blogs are increasingly used by EM trainees and clinicians. However, quality evaluations of these resources using gestalt are unreliable. We investigated the reliability of two previously derived quality evaluation instruments for blogs. Sixty English-language EM websites that published clinically oriented blog posts between January 1 and February 24, 2016, were identified. A random number generator selected 10 websites, and the 2 most recent clinically oriented blog posts from each site were evaluated using gestalt, the Academic Life in Emergency Medicine (ALiEM) Approved Instructional Resources (AIR) score, and the Medical Education Translational Resources: Impact and Quality (METRIQ-8) score, by a sample of medical students, EM residents, and EM attendings. Each rater evaluated all 20 blog posts with gestalt and 15 of the 20 blog posts with the ALiEM AIR and METRIQ-8 scores. Pearson's correlations were calculated between the average scores for each metric. Single-measure intraclass correlation coefficients (ICCs) evaluated the reliability of each instrument. Our study included 121 medical students, 88 EM residents, and 100 EM attendings who completed ratings. The average gestalt rating of each blog post correlated strongly with the average scores for ALiEM AIR (r = .94) and METRIQ-8 (r = .91). Single-measure ICCs were fair for gestalt (0.37, IQR 0.25-0.56), ALiEM AIR (0.41, IQR 0.29-0.60) and METRIQ-8 (0.40, IQR 0.28-0.59). The average scores of each blog post correlated strongly with gestalt ratings. However, neither ALiEM AIR nor METRIQ-8 showed higher reliability than gestalt. Improved reliability may be possible through rater training and instrument refinement.

  7. First quality score for referral letters in gastroenterology-a validation study.

    Science.gov (United States)

    Eskeland, Sigrun Losada; Brunborg, Cathrine; Seip, Birgitte; Wiencke, Kristine; Hovde, Øistein; Owen, Tanja; Skogestad, Erik; Huppertz-Hauss, Gert; Halvorsen, Fred-Arne; Garborg, Kjetil; Aabakken, Lars; de Lange, Thomas

    2016-10-08

    To create and validate an objective and reliable score to assess referral quality in gastroenterology. An observational multicentre study. 25 gastroenterologists participated in selecting variables for a Thirty Point Score (TPS) for quality assessment of referrals to gastroenterology specialist healthcare for 9 common indications. From May to September 2014, 7 hospitals from the South-Eastern Norway Regional Health Authority participated in collecting and scoring 327 referrals to a gastroenterologist. Correlation between the TPS and a visual analogue scale (VAS) for referral quality. The 327 referrals had an average TPS of 13.2 (range 1-25) and an average VAS of 4.7 (range 0.2-9.5). The reliability of the score was excellent, with an intra-rater intraclass correlation coefficient (ICC) of 0.87 and inter-rater ICC of 0.91. The overall correlation between the TPS and the VAS was moderate (r=0.42), and ranged from fair to substantial for the various indications. Mean agreement was good (ICC=0.47, 95% CI (0.34 to 0.57)), ranging from poor to good. The TPS is reliable, objective and shows good agreement with the subjective VAS. The score may be a useful tool for assessing referral quality in gastroenterology, particularly important when evaluating the effect of interventions to improve referral quality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. A Novel Scoring Metrics for Quality Assurance of Ocean Color Observations

    Science.gov (United States)

    Wei, J.; Lee, Z.

    2016-02-01

    Interpretation of the ocean bio-optical properties from ocean color observations depends on the quality of the ocean color data, specifically the spectrum of remote sensing reflectance (Rrs). The in situ and remotely measured Rrs spectra are inevitably subject to errors induced by instrument calibration, sea-surface correction and atmospheric correction, and other environmental factors. Great efforts have been devoted to the ocean color calibration and validation. Yet, there exist no objective and consensus criteria for assessment of the ocean color data quality. In this study, the gap is filled by developing a novel metrics for such data quality assurance and quality control (QA/QC). This new QA metrics is not intended to discard "suspicious" Rrs spectra from available datasets. Rather, it takes into account the Rrs spectral shapes and amplitudes as a whole and grades each Rrs spectrum. This scoring system is developed based on a large ensemble of in situ hyperspectral remote sensing reflectance data measured from various aquatic environments and processed with robust procedures. This system is further tested with the NASA bio-Optical Marine Algorithm Data set (NOMAD), with results indicating significant improvements in the estimation of bio-optical properties when Rrs spectra marked with higher quality assurance are used. This scoring system is further verified with simulated data and satellite ocean color data in various regions, and we envision higher quality ocean color products with the implementation of such a quality screening system.

  9. Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist.

    Science.gov (United States)

    Terwee, Caroline B; Mokkink, Lidwine B; Knol, Dirk L; Ostelo, Raymond W J G; Bouter, Lex M; de Vet, Henrica C W

    2012-05-01

    The COSMIN checklist is a standardized tool for assessing the methodological quality of studies on measurement properties. It contains 9 boxes, each dealing with one measurement property, with 5-18 items per box about design aspects and statistical methods. Our aim was to develop a scoring system for the COSMIN checklist to calculate quality scores per measurement property when using the checklist in systematic reviews of measurement properties. The scoring system was developed based on discussions among experts and testing of the scoring system on 46 articles from a systematic review. Four response options were defined for each COSMIN item (excellent, good, fair, and poor). A quality score per measurement property is obtained by taking the lowest rating of any item in a box ("worst score counts"). Specific criteria for excellent, good, fair, and poor quality for each COSMIN item are described. In defining the criteria, the "worst score counts" algorithm was taken into consideration. This means that only fatal flaws were defined as poor quality. The scores of the 46 articles show how the scoring system can be used to provide an overview of the methodological quality of studies included in a systematic review of measurement properties. Based on experience in testing this scoring system on 46 articles, the COSMIN checklist with the proposed scoring system seems to be a useful tool for assessing the methodological quality of studies included in systematic reviews of measurement properties.

  10. The use of a dietary quality score as a predictor of childhood overweight and obesity.

    Science.gov (United States)

    Perry, Catherine P; Keane, Eimear; Layte, Richard; Fitzgerald, Anthony P; Perry, Ivan J; Harrington, Janas M

    2015-06-24

    The use of dietary quality scores/indices to describe diet quality in children has increased in the past decade. However, to date, few studies have focused on the use of these scores on disease outcomes such as childhood obesity and most are developed from detailed dietary assessments. Therefore, the aims of this study were: firstly to construct a diet quality score (DQS) from a brief dietary assessment tool; secondly to examine the association between diet quality and childhood overweight or obesity; thirdly we also aim to examine the associations between individual DQS components and childhood overweight or obesity. A secondary analysis of cross sectional data of a sample of 8,568 9-year-old children and their families as part of the Growing Up in Ireland (GUI) study. Subjects were drawn from a probability proportionate to size sampling of primary schools throughout Ireland over the school year 2007-2008. Height and weight were measured by trained researchers using standardised methods and BMI was classified using the International Obesity Taskforce cut-points. The DQS (un-weighted) was developed using a 20-item, parent reported, food frequency questionnaire of foods consumed over the past 24 h. Adjusted odds ratios for overweight and obesity were examined by DQS quintile, using the first quintile (highest diet quality) as the reference category. The prevalence of normal weight, overweight and obese was 75, 19 and 6% respectively. DQS ranged from -5 to 25, higher scores indicated higher diet quality in the continuous score. In analyses adjusted for gender, parent's education, physical activity and T.V. viewing, child obesity but not overweight was significantly associated with poor diet quality: OR of 1.56 (95% CI 1.02 2.38) in the 5th compared to the 1st DQS quintile. Findings from individual food items were inconsistent. The findings suggest that diet quality may be an important factor in childhood obesity. A simple DQS developed from a short dietary assessment

  11. Key performance indicators score (KPIs-score) based on clinical and laboratorial parameters can establish benchmarks for internal quality control in an ART program.

    Science.gov (United States)

    Franco, José G; Petersen, Claudia G; Mauri, Ana L; Vagnini, Laura D; Renzi, Adriana; Petersen, Bruna; Mattila, M C; Comar, Vanessa A; Ricci, Juliana; Dieamant, Felipe; Oliveira, João Batista A; Baruffi, Ricardo L R

    2017-06-01

    KPIs have been employed for internal quality control (IQC) in ART. However, clinical KPIs (C-KPIs) such as age, AMH and number of oocytes collected are never added to laboratory KPIs (L-KPIs), such as fertilization rate and morphological quality of the embryos for analysis, even though the final endpoint is the evaluation of clinical pregnancy rates. This paper analyzed if a KPIs-score strategy with clinical and laboratorial parameters could be used to establish benchmarks for IQC in ART cycles. In this prospective cohort study, 280 patients (36.4±4.3years) underwent ART. The total KPIs-score was obtained by the analysis of age, AMH (AMH Gen II ELISA/pre-mixing modified, Beckman Coulter Inc.), number of metaphase-II oocytes, fertilization rates and morphological quality of the embryonic lot. The total KPIs-score (C-KPIs+L-KPIs) was correlated with the presence or absence of clinical pregnancy. The relationship between the C-KPIs and L-KPIs scores was analyzed to establish quality standards, to increase the performance of clinical and laboratorial processes in ART. The logistic regression model (LRM), with respect to pregnancy and total KPIs-score (280 patients/102 clinical pregnancies), yielded an odds ratio of 1.24 (95%CI = 1.16-1.32). There was also a significant difference (pclinical pregnancies (total KPIs-score=20.4±3.7) and the group without clinical pregnancies (total KPIs-score=15.9±5). Clinical pregnancy probabilities (CPP) can be obtained using the LRM (prediction key) with the total KPIs-score as a predictor variable. The mean C-KPIs and L-KPIs scores obtained in the pregnancy group were 11.9±2.9 and 8.5±1.7, respectively. Routinely, in all cases where the C-KPIs score was ≥9, after the procedure, the L-KPIs score obtained was ≤6, a revision of the laboratory procedure was performed to assess quality standards. This total KPIs-score could set up benchmarks for clinical pregnancy. Moreover, IQC can use C-KPIs and L-KPIs scores to detect problems

  12. Complications among colorectal cancer survivors: SF-6D preference-weighted quality of life scores.

    Science.gov (United States)

    Hornbrook, Mark C; Wendel, Christopher S; Coons, Stephen Joel; Grant, Marcia; Herrinton, Lisa J; Mohler, M Jane; Baldwin, Carol M; McMullen, Carmit K; Green, Sylvan B; Altschuler, Andrea; Rawl, Susan M; Krouse, Robert S

    2011-03-01

    Societal preference-weighted health-related quality of life (HRQOL) scores enable comparing multidimensional health states across diseases and treatments for research and policy. To assess the effects of living with a permanent intestinal stoma, compared with a major bowel resection, among colorectal cancer (CRC) survivors. Cross-sectional multivariate linear regression analysis to explain preference-weighted HRQOL scores. In all, 640 CRC survivors (≥ 5 years) from 3 group model health maintenance organizations; ostomates and nonostomates with colorectal resections for CRC were matched on gender, age (± 5 years), time since diagnosis, and tumor site (rectum vs. colon). SF-6D scoring system was applied to Medical Outcomes Study Short Form-36 version 2 (SF-36v2); City of Hope Quality of Life-Ostomy; and Charlson-Deyo comorbidity index. Survey of CRC survivors linked to respondents' clinical data extracted from health maintenance organization files. Response rate was 52%. Ostomates and nonostomates had similar sociodemographic characteristics. Mean SF-6D score was 0.69 for ostomates, compared with 0.73 for nonostomates (P ostomy after other factors were taken into account. Surgical complications, comorbidities, and metastatic disease lowered the preference-weighted HRQOL of CRC survivors with and without ostomies. Further research to understand and reduce late complications from CRC surgeries as well as associated depression is warranted.

  13. Using quality scores and longer reads improves accuracy of Solexa read mapping

    Directory of Open Access Journals (Sweden)

    Xuan Zhenyu

    2008-02-01

    Full Text Available Abstract Background Second-generation sequencing has the potential to revolutionize genomics and impact all areas of biomedical science. New technologies will make re-sequencing widely available for such applications as identifying genome variations or interrogating the oligonucleotide content of a large sample (e.g. ChIP-sequencing. The increase in speed, sensitivity and availability of sequencing technology brings demand for advances in computational technology to perform associated analysis tasks. The Solexa/Illumina 1G sequencer can produce tens of millions of reads, ranging in length from ~25–50 nt, in a single experiment. Accurately mapping the reads back to a reference genome is a critical task in almost all applications. Two sources of information that are often ignored when mapping reads from the Solexa technology are the 3' ends of longer reads, which contain a much higher frequency of sequencing errors, and the base-call quality scores. Results To investigate whether these sources of information can be used to improve accuracy when mapping reads, we developed the RMAP tool, which can map reads having a wide range of lengths and allows base-call quality scores to determine which positions in each read are more important when mapping. We applied RMAP to analyze data re-sequenced from two human BAC regions for varying read lengths, and varying criteria for use of quality scores. RMAP is freely available for downloading at http://rulai.cshl.edu/rmap/. Conclusion Our results indicate that significant gains in Solexa read mapping performance can be achieved by considering the information in 3' ends of longer reads, and appropriately using the base-call quality scores. The RMAP tool we have developed will enable researchers to effectively exploit this information in targeted re-sequencing projects.

  14. Bowel Endometriosis Syndrome: a new scoring system for pelvic organ dysfunction and quality of life.

    Science.gov (United States)

    Riiskjær, M; Egekvist, A G; Hartwell, D; Forman, A; Seyer-Hansen, M; Kesmodel, U S

    2017-09-01

    Is it possible to develop a validated score that can identify women with Bowel Endometriosis Syndrome (BENS) and be used to monitor the effect of medical and surgical treatment? The BENS score can be used to identify women with BENS and to monitor the effect of medical and surgical treatment of women suffering from bowel endometriosis. Endometriosis is a heterogeneous disease with extensive variation in anatomical and clinical presentation, and symptoms do not always correspond to the disease burden. Current endometriosis scoring systems are mainly based on anatomical and surgical findings. The score was developed and validated from a cohort of 525 women with medically or surgically treated bowel endometriosis from Aarhus and Copenhagen University Hospitals, Denmark. Patients filled in questionnaires on pelvic pain, quality of life (QoL) and urinary, sexual and bowel function. Items were selected for the final score using clinical and statistical criteria. The chosen variables were included in a multivariate analysis. Individual score values were designated items to form the BENS score, which was divided into 'no BENS', 'minor BENS' and 'major BENS.' Internal and external validations were performed. The six most important items were 'pelvic pain', 'use of analgesics', 'dyschezia', 'straining to urinate', 'fecal urgency' and 'satisfaction with sexual life'. The range of the BENS score (0-28) was divided into 0-8 (no BENS), 9-16 (minor BENS) and 17-28 (major BENS). External validation showed a significant association between BENS score and QoL (P = 0.0001). The BENS scoring system is limited by the fact that it was developed from a single endometriosis unit in Denmark, making it susceptible to social, cultural and demographic bias. It is the first endometriosis classification system to be based directly on the symptomatology of the patient. Validation in other languages will promote comparison of treatments and results across borders. No external funding was either

  15. Depression, anxiety and quality of life scores in seniors after an endurance exercise program

    Directory of Open Access Journals (Sweden)

    Antunes Hanna Karen Moreira

    2005-01-01

    Full Text Available OBJECTIVE: Mood disorders are a frequent problem in old age, and their symptoms constitute an important public health issue. These alterations affect the quality of life mainly by restricting social life. The participation in a regular exercise program is an effective way of reducing or preventing the functional decline associated with aging. The aim of the present study was to examine the effects of fitness-endurance activity (at the intensity of Ventilatory Threshold 1 (VT-1 in depression, anxiety and quality of life scores in seniors. METHODS: The study involved 46 sedentary seniors aged 60-75 (66.97 ± 4.80 who were randomly allocated to two groups: 1 Control group, which was neither asked to vary their everyday activities nor to join a regular physical fitness program; and 2 Experimental group, whose members took part in an aerobic fitness program consisting of ergometer cycle sessions 3 times a week on alternate days for six months working at a heart rate corresponding to ventilatory threshold (VT-1 intensity. Subjects were submitted to a basal evaluation using the geriatric depression screening scale - GDS, STAI trait/state (anxiety scale and SF-36 (quality of life scale. RESULTS: Comparing the groups after the study period, we found a significant decrease in depressive and anxiety scores and an improvement in the quality of life in the experimental group, but no significant changes in the control group. CONCLUSION: The data suggest that an aerobic exercise program at VT-1 intensity suffices to promote favorable modifications in depressive and anxiety scores to improve the quality of life in seniors.

  16. A Prototype Public Speaking Skills Assessment: An Evaluation of Human-Scoring Quality. Research Report. ETS RR-15-36

    Science.gov (United States)

    Joe, Jilliam; Kitchen, Christopher; Chen, Lei; Feng, Gary

    2015-01-01

    The purpose of this paper is to summarize the evaluation of human-scoring quality for an assessment of public speaking skills. Videotaped performances given by 17 speakers on 4 tasks were scored by expert and nonexpert raters who had extensive experience scoring performance-based and constructed-response assessments. The Public Speaking Competence…

  17. Validation of the Six Sigma Z-score for the quality assessment of clinical laboratory timeliness.

    Science.gov (United States)

    Ialongo, Cristiano; Bernardini, Sergio

    2018-03-28

    The International Federation of Clinical Chemistry and Laboratory Medicine has introduced in recent times the turnaround time (TAT) as mandatory quality indicator for the postanalytical phase. Classic TAT indicators, namely, average, median, 90th percentile and proportion of acceptable test (PAT), are in use since almost 40 years and to date represent the mainstay for gauging the laboratory timeliness. In this study, we investigated the performance of the Six Sigma Z-score, which was previously introduced as a device for the quantitative assessment of timeliness. A numerical simulation was obtained modeling the actual TAT data set using the log-logistic probability density function. Five thousand replicates for each size of the artificial TAT random sample (n=20, 50, 250 and 1000) were generated, and different laboratory conditions were simulated manipulating the PDF in order to generate more or less variable data. The Z-score and the classic TAT indicators were assessed for precision (%CV), robustness toward right-tailing (precision at different sample variability), sensitivity and specificity. Z-score showed sensitivity and specificity comparable to PAT (≈80% with n≥250), but superior precision that ranged within 20% by moderately small sized samples (n≥50); furthermore, Z-score was less affected by the value of the cutoff used for setting the acceptable TAT, as well as by the sample variability that reflected into the magnitude of right-tailing. The Z-score was a valid indicator of laboratory timeliness and a suitable device to improve as well as to maintain the achieved quality level.

  18. Improving iris recognition performance using segmentation, quality enhancement, match score fusion, and indexing.

    Science.gov (United States)

    Vatsa, Mayank; Singh, Richa; Noore, Afzel

    2008-08-01

    This paper proposes algorithms for iris segmentation, quality enhancement, match score fusion, and indexing to improve both the accuracy and the speed of iris recognition. A curve evolution approach is proposed to effectively segment a nonideal iris image using the modified Mumford-Shah functional. Different enhancement algorithms are concurrently applied on the segmented iris image to produce multiple enhanced versions of the iris image. A support-vector-machine-based learning algorithm selects locally enhanced regions from each globally enhanced image and combines these good-quality regions to create a single high-quality iris image. Two distinct features are extracted from the high-quality iris image. The global textural feature is extracted using the 1-D log polar Gabor transform, and the local topological feature is extracted using Euler numbers. An intelligent fusion algorithm combines the textural and topological matching scores to further improve the iris recognition performance and reduce the false rejection rate, whereas an indexing algorithm enables fast and accurate iris identification. The verification and identification performance of the proposed algorithms is validated and compared with other algorithms using the CASIA Version 3, ICE 2005, and UBIRIS iris databases.

  19. Oral health-related quality-of-life scores differ by socioeconomic status and caries experience.

    Science.gov (United States)

    Chaffee, Benjamin W; Rodrigues, Priscila Humbert; Kramer, Paulo Floriani; Vítolo, Márcia Regina; Feldens, Carlos Alberto

    2017-06-01

    (i) Quantify the relative association between child dental caries experience and maternal-reported child oral health-related quality of life (OHRQoL); (ii) examine whether that association differed according to family socioeconomic status (SES); and (iii) explore whether absolute OHRQoL varied by family SES at similar levels of child caries experience. This study was a cross-sectional analysis of children in southern Brazil (n=456, mean age: 38 months) participating in an existing health centre-based intervention study. OHRQoL impact was quantified as mean score on the Brazilian Early Childhood Oral Health Impact Scale (ECOHIS) and compared over categories of caries experience (dmft: 0, dmft: 1-4, dmft: ≥5). Adjusted ECOHIS ratios between caries categories were calculated using regression modelling, overall and within socioeconomic strata defined by maternal education, social class and household income. Caries prevalence (dmft >0) was 39.7%, mean ECOHIS score was 2.0 (SD: 3.5), and 44.3% of mothers reported OHRQoL impact (ECOHIS score >0). Increasing child caries experience was associated with worsening child and family quality of life: ECOHIS scores were 3.0 times greater (95% CI: 2.0, 4.4) for children with dmft ≥5 vs dmft=0, a pattern that persisted regardless of family socioeconomic status (P for interaction: all >0.3). However, adjusted for dental status and sociodemographic characteristics, mean ECOHIS scores were lower when reported by mothers of less educational attainment (ratio: 0.7; 95% CI: 0.5, 1.0), lower social class (ratio: 0.7; 95% CI: 0.5, 1.0) or in lower income households (ratio: 0.8; 95% CI: 0.6, 1.3). Dental caries was associated with negative child and family experiences and lower OHRQoL across all social groups; yet, families facing greater disadvantage may report lesser quality-of-life impact at the same level of disease experience. Thus, subjective quality-of-life measures may differ under varying social contexts, with possible

  20. Ab initio pseudopotential theory

    International Nuclear Information System (INIS)

    Yin, M.T.; Cohen, M.L.

    1982-01-01

    The ab initio norm-conserving pseudopotential is generated from a reference atomic configuration in which the pseudoatomic eigenvalues and wave functions outside the core region agree with the corresponding ab initio all-electron results within the density-functional formalism. This paper explains why such pseudopotentials accurately reproduce the all-electron results in both atoms and in multiatomic systems. In particular, a theorem is derived to demonstrate the energy- and perturbation-independent properties of ab initio pseudopotentials

  1. Do employers know the quality of health care benefits they provide? Use of HEDIS depression scores for health plans.

    Science.gov (United States)

    Robst, John; Rost, Kathryn; Marshall, Donna

    2013-11-01

    OBJECTIVE Dissemination of health quality measures is a necessary ingredient of efforts to harness market-based forces, such as value-based purchasing by employers, to improve health care quality. This study examined reporting of Healthcare Effectiveness Data and Information Set (HEDIS) measures for depression to firms interested in improving depression care. METHODS During surveys conducted between 2009 and 2011, a sample of 325 employers that were interested in improving depression treatment were asked whether their primary health plan reports HEDIS scores for depression to the National Committee for Quality Assurance (NCQA) and if so, whether they knew the scores. Data about HEDIS reporting by the health plans were collected from the NCQA. RESULTS HEDIS depression scores were reported by the primary health plans of 154 (47%) employers, but only 7% of employers knew their plan's HEDIS scores. Because larger employers were more likely to report knowing the scores, 53% of all employees worked for employers who reported knowing the scores. A number of structural, health benefit, and need characteristics predicted knowledge of HEDIS depression scores by employers. CONCLUSIONS The study demonstrated that motivated employers did not know their depression HEDIS scores even when their plan publicly reported them. Measures of health care quality are not reaching the buyers of insurance products; however, larger employers were more likely to know the HEDIS scores for their health plan, suggesting that value-based purchasing may have some ability to affect health care quality.

  2. Scoring Mental Health Quality of Life With the SF-36 in Patients With and Without Diabetes Foot Complications.

    Science.gov (United States)

    Ahn, Junho; Del Core, Michael A; Wukich, Dane K; Liu, George T; Lalli, Trapper; VanPelt, Michael D; La Fontaine, Javier; Lavery, Lawrence A; Raspovic, Katherine M

    2018-03-01

    The aim of this study was to examine if using orthogonal and oblique factor analysis detect changes in health-related quality of life differently in diabetic patients on the Short Form-36 (SF-36) survey. A total of 155 patients had diabetic foot complications (DFC), and 145 patients had no DFCs. The SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were calculated using scoring coefficients determined by orthogonal and oblique rotation principle component analyses of the subscales. The DFC group had lower orthogonal ( P < .00001) and oblique PCS scores ( P < .00001). However, despite lower Mental Health subscale scores in the patients with DFCs, orthogonal MCS scores ( P = .156) did not differ. In contrast, the oblique MCS scores reflected the difference in the Mental Health subscale ( P = .0005). Orthogonal and oblique PCS scores did not differ significantly. However, orthogonal MCS scores were significantly higher than oblique MCS scores in those with DFCs ( P = .0004) and without DFCs ( P = .005). The shorter, 12-item SF-12 survey demonstrated similar results. Poorer physical function leads to higher orthogonal MCS scores than if determined by oblique scoring coefficients since Physical Function, Bodily Pain, and General Health are weighted more negatively in orthogonal coefficients when calculating the MCS score. Oblique scoring coefficients may address this issue, but further study is necessary to confirm whether oblique MCS scores accurately represent the mental health of patients with diabetic foot disease.

  3. A new multimodal interactive way of subjective scoring of 3D video quality of experience

    Science.gov (United States)

    Kim, Taewan; Lee, Kwanghyun; Lee, Sanghoon; Bovik, Alan C.

    2014-03-01

    People that watch today's 3D visual programs, such as 3D cinema, 3D TV and 3D games, experience wide and dynamically varying ranges of 3D visual immersion and 3D quality of experience (QoE). It is necessary to be able to deploy reliable methodologies that measure each viewers subjective experience. We propose a new methodology that we call Multimodal Interactive Continuous Scoring of Quality (MICSQ). MICSQ is composed of a device interaction process between the 3D display and a separate device (PC, tablet, etc.) used as an assessment tool, and a human interaction process between the subject(s) and the device. The scoring process is multimodal, using aural and tactile cues to help engage and focus the subject(s) on their tasks. Moreover, the wireless device interaction process makes it possible for multiple subjects to assess 3D QoE simultaneously in a large space such as a movie theater, and at di®erent visual angles and distances.

  4. Quantifying radioxerostomia: salivary flow rate, examiner's score, and quality of life questionnaire

    International Nuclear Information System (INIS)

    Al-Nawas, B.; Al-Nawas, K.; Kunkel, M.; Groetz, K.A.

    2006-01-01

    Background and purpose: salivary flow rates alone are not sufficient to quantify all aspects of radioxerostomia. This is a problem in studies aiming to reduce radioxerostomia. The aim of this study was to evaluate the association between objectively measured salivary flow rate and subjective xerostomia ratings by the physician (RTOG scale) or the patients (quality of life [QoL] questionnaire). Patients and methods: in a case-control study patients who underwent recall for oral cancer were screened. Inclusion criteria for this diagnostic, noninterventional study were: history of oral carcinoma, surgical and radiation therapy, time interval from start of radiation therapy > 90 days, salivary glands within the radiation field. The control group consisted of patients, who had not received radiotherapy. RTOG salivary gland score, quality of life (EORTC QLQ-C30 and H and N35), and sialometry were recorded. Results: patients with RTOG score 0 had mean salivary flow rates of 0.3 ml/min, those with RTOG 1 0.12 ml/min, RTOG 2 0.02 ml/min, and RTOG 3 < 0.01 ml/min. RTOG score 4 (total fibrosis) did not occur. Based on salivary flow rates, all patients were grouped into xerostomia < 0.2 ml/min (30 patients) and nonxerostomia (twelve patients). QoL results revealed significant differences between patients with xerostomia and nonxerostomia for physical function, dyspnea, swallowing, social eating, dry mouth, nutritional support, and a tendency to higher values for appetite loss. Conclusion: the correlation between ''subjective'' QoL parameters and salivary flow was confirmed. The different subjective aspects of radioxerostomia seem to be better differentiated by the EORTC QoL questionnaire. (orig.)

  5. Quantifying radioxerostomia: salivary flow rate, examiner's score, and quality of life questionnaire

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nawas, B.; Al-Nawas, K.; Kunkel, M.; Groetz, K.A. [Dept. of Oral and Maxillofacial Surgery, Hospital of the Johannes Gutenberg Univ., Mainz (Germany)

    2006-06-15

    Background and purpose: salivary flow rates alone are not sufficient to quantify all aspects of radioxerostomia. This is a problem in studies aiming to reduce radioxerostomia. The aim of this study was to evaluate the association between objectively measured salivary flow rate and subjective xerostomia ratings by the physician (RTOG scale) or the patients (quality of life [QoL] questionnaire). Patients and methods: in a case-control study patients who underwent recall for oral cancer were screened. Inclusion criteria for this diagnostic, noninterventional study were: history of oral carcinoma, surgical and radiation therapy, time interval from start of radiation therapy > 90 days, salivary glands within the radiation field. The control group consisted of patients, who had not received radiotherapy. RTOG salivary gland score, quality of life (EORTC QLQ-C30 and H and N35), and sialometry were recorded. Results: patients with RTOG score 0 had mean salivary flow rates of 0.3 ml/min, those with RTOG 1 0.12 ml/min, RTOG 2 0.02 ml/min, and RTOG 3 < 0.01 ml/min. RTOG score 4 (total fibrosis) did not occur. Based on salivary flow rates, all patients were grouped into xerostomia < 0.2 ml/min (30 patients) and nonxerostomia (twelve patients). QoL results revealed significant differences between patients with xerostomia and nonxerostomia for physical function, dyspnea, swallowing, social eating, dry mouth, nutritional support, and a tendency to higher values for appetite loss. Conclusion: the correlation between ''subjective'' QoL parameters and salivary flow was confirmed. The different subjective aspects of radioxerostomia seem to be better differentiated by the EORTC QoL questionnaire. (orig.)

  6. Quality of Life Score as a Predictor of Death in Dogs with Degenerative Mitral Valve Disease.

    Science.gov (United States)

    Strunz, Célia M C; Marcondes-Santos, Mário; Takada, Julio Yoshio; Fragata, Fernanda S; Mansur, Antônio de Pádua

    2017-04-01

    The knowledge of the variables predicting mortality is important in clinical practice and for therapeutic monitoring in mitral valve disease. To determine whether a quality of life score evaluated with the Functional Evaluation of Cardiac Health questionnaire would predict mortality in dogs with degenerative mitral valve disease (DMVD). Thirty-six client-owned dogs with mitral valve disease underwent clinical, laboratory, and echocardiographic evaluations at baseline and were monitored for 6 months. Cardiovascular death was the primary outcome. The 36 dogs were classified as survivors or nonsurvivors. Higher values of the following variables were obtained at baseline in the nonsurviving group (12 dogs): amino-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, plasma norepinephrine, heart rate, quality of life score, diastolic left ventricular internal dimension to aortic root ratio, systolic left ventricular internal dimension to aortic root ratio, and left atrium to aortic root ratio. NT-proBNP levels and quality life score were independently associated with death in the multivariable analysis. The quality life score was an independent variable for cardiac death in dogs with DMVD. This result is encouraging, as this score is easy to apply and does not require any technology, only a veterinarian and an observant owner. O conhecimento das variáveis preditoras de mortalidade é importante para a prática clínica e para o acompanhamento terapêutico na doença da valva mitral. Determinar se um escore de qualidade de vida avaliado com o Functional Evaluation of Cardiac Health poderia auxiliar na predição de mortalidade em cães com doença degenerativa da valva mitral (DDVM). Trinta e seis cães de estimação com doença valvar mitral foram submetidos a avaliação clínica, laboratorial e ecocardiográfica no início do estudo e monitorizados durante 6 meses. A morte cardiovascular foi o desfecho primário. Os 36 cães foram classificados como

  7. Translation and validation of the Danish version of the postoperative quality of recovery score QoR-15

    DEFF Research Database (Denmark)

    Kleif, J; Edwards, H M; Sort, R

    2015-01-01

    .12 to -0.43, P half reliability was 0.90 and 0.88. Test-retest reliability was 0.99 (95% CI: 0......BACKGROUND: Patient perceived quality of recovery is an important outcome after surgery and should be measured in clinical trials. Quality of recovery after surgery and general anaesthesia can be measured by the QoR-15. A high score indicates a good recovery and the score ranges from 0 to 150...

  8. Paediatric early warning scores on a children's ward: a quality improvement initiative.

    LENUS (Irish Health Repository)

    Ennis, Linda

    2014-09-09

    The aim of this quality improvement initiative was to incorporate a paediatric early warning score (PEWS) and track and trigger system in the routine care of children in an acute general children\\'s ward at a regional hospital in the Republic of Ireland. In the absence of a nationally recommended specific PEWS strategy, a local plan was developed. The experience of structuring and implementing the PEWS and track and trigger system is presented in this article. Data from the first year of use were collected to evaluate the clinical utility and effectiveness of this system. In the busy acute children\\'s service, the PEWS initiative was found to benefit processes of early detection, prompt referral and timely, appropriate management of children at potential risk of clinical deterioration. Nursing staff were empowered and supported to communicate concerns immediately and to seek rapid medical review, according to an agreed PEWS escalation plan. Outcomes were significantly improved.

  9. Index admission laparoscopic cholecystectomy for acute cholecystitis restores Gastrointestinal Quality of Life Index (GIQLI) score.

    Science.gov (United States)

    Yu, Hongyan; Chan, Esther Ern-Hwei; Lingam, Pravin; Lee, Jingwen; Woon, Winston Wei Liang; Low, Jee Keem; Shelat, Vishal G

    2018-02-01

    Previous studies have evaluated quality of life (QoL) in patients who underwent laparoscopic cholecystectomy (LC) for cholelithiasis. The purpose of this study was to evaluate QoL after index admission LC in patients diagnosed with acute cholecystitis (AC) using the Gastrointestinal Quality of Life Index (GIQLI) questionnaire. Patients ≥21 years admitted to Tan Tock Seng Hospital, Singapore for AC and who underwent index admission LC between February 2015 and January 2016 were evaluated using the GIQLI questionnaire preoperatively and 30 days postoperatively. A total of 51 patients (26 males, 25 females) with a mean age of 60 years (24-86 years) were included. Median duration of abdominal pain at presentation was 2 days (1-21 days). 45% of patients had existing comorbidities, with diabetes mellitus being most common (33%). 31% were classified as mild AC, 59% as moderate and 10% as severe AC according to Tokyo Guideline 2013 (TG13) criteria. Post-operative complications were observed in 8 patients, including retained common bile duct stone (n=1), wound infection (n=2), bile leakage (n=2), intra-abdominal collection (n=1) and atrial fibrillation (n=2). 86% patients were well at 30 days follow-up and were discharged. A significant improvement in GIQLI score was observed postoperatively, with mean total GIQLI score increasing from 106.0±16.9 (101.7-112.1) to 120.4±18.0 (114.8-125.9) ( p <0.001). Significant improvements were also observed in GIQLI subgroups of gastrointestinal symptoms, physical status, emotional status and social function status. Index admission LC restores QoL in patients with AC as measured by GIQLI questionnaire.

  10. Negative emotions affect postoperative scores for evaluating functional knee recovery and quality of life after total knee replacement

    Directory of Open Access Journals (Sweden)

    A. Qi

    2016-01-01

    Full Text Available This study aimed to determine whether psychological factors affect health-related quality of life (HRQL and recovery of knee function in total knee replacement (TKR patients. A total of 119 TKR patients (male: 38; female: 81 completed the Beck Anxiety Inventory (BAI, Beck Depression Inventory (BDI, State Trait Anxiety Inventory (STAI, Eysenck Personality Questionnaire-revised (EPQR-S, Knee Society Score (KSS, and HRQL (SF-36. At 1 and 6 months after surgery, anxiety, depression, and KSS scores in TKR patients were significantly better compared with those preoperatively (P<0.05. SF-36 scores at the sixth month after surgery were significantly improved compared with preoperative scores (P<0.001. Preoperative Physical Component Summary Scale (PCS and Mental Component Summary Scale (MCS scores were negatively associated with extraversion (E score (B=-0.986 and -0.967, respectively, both P<0.05. Postoperative PCS and State Anxiety Inventory (SAI scores were negatively associated with neuroticism (N score; B=-0.137 and -0.991, respectively, both P<0.05. Postoperative MCS, SAI, Trait Anxiety Inventory (TAI, and BAI scores were also negatively associated with the N score (B=-0.367, -0.107, -0.281, and -0.851, respectively, all P<0.05. The KSS function score at the sixth month after surgery was negatively associated with TAI and N scores (B=-0.315 and -0.532, respectively, both P<0.05, but positively associated with the E score (B=0.215, P<0.05. The postoperative KSS joint score was positively associated with postoperative PCS (B=0.356, P<0.05. In conclusion, for TKR patients, the scores used for evaluating recovery of knee function and HRQL after 6 months are inversely associated with the presence of negative emotions.

  11. The microcirculation image quality score: development and preliminary evaluation of a proposed approach to grading quality of image acquisition for bedside videomicroscopy.

    Science.gov (United States)

    Massey, Michael J; Larochelle, Ethan; Najarro, Gabriel; Karmacharla, Adarsh; Arnold, Ryan; Trzeciak, Stephen; Angus, Derek C; Shapiro, Nathan I

    2013-12-01

    Side-stream dark-field microscopy is currently used to directly visualize sublingual microcirculation at the bedside. Our experience has found inherent technical challenges in the image acquisition process. This article presents and assesses a quality assurance method to rate image acquisition quality before analysis. We identified 6 common image capture and analysis problem areas in sublingual side-stream dark-field videos: illumination, duration, focus, content, stability, and pressure. We created the "Microcirculation Image Quality Score" by assigning a score of optimal (0 points), suboptimal but acceptable (1 point), or unacceptable (10 points) to each category (for further details, go to http://www.MicroscanAnalysis.blogspot.com). We evaluated 59 videos from a convenience sample of 34 unselected, noncritically ill emergency department patients to create a test set. Two raters, blinded to each other, implemented the score. Any video with a cumulative score of 10 or higher (range, 0-60) was considered unacceptable for further analysis. We created the Microcirculation Image Quality Score and applied it to 59 videos. For this particular set of 59 videos, the mean (SD) passing quality score was 1.68 (0.90), and the mean (SD) failing quality score was 15.74 (6.19), with 27 of 59 passing the quality score less than 10. Highest failure occurred from pressure artifact. The interrater agreement for acceptability was assessed using Cohen κ for each category: illumination (κ = 1.0), duration (κ = 1.0), focus (κ = 0.91), content (κ = 0.76), stability (κ = 0.71), and pressure (κ = 0.82) and overall pass-fail rates (score >10) (κ = 0.66). Our Microcirculation Image Quality Score addresses many of the common areas where video quality can degrade. The criteria introduced are an objective way to assess the quality of image acquisition, with the goal of selecting videos of adequate quality for analysis. The interrater reliability results in our preliminary study suggest

  12. An ab initio molecular

    Indian Academy of Sciences (India)

    mechanisms of two molecular crystals: An ab initio molecular dynamics ... for Computation in Molecular and Materials Science and Department of Chemistry, School of ..... NSAF Foundation of National Natural Science Foun- ... Matter 14 2717.

  13. Longitudinal beta regression models for analyzing health-related quality of life scores over time

    Directory of Open Access Journals (Sweden)

    Hunger Matthias

    2012-09-01

    Full Text Available Abstract Background Health-related quality of life (HRQL has become an increasingly important outcome parameter in clinical trials and epidemiological research. HRQL scores are typically bounded at both ends of the scale and often highly skewed. Several regression techniques have been proposed to model such data in cross-sectional studies, however, methods applicable in longitudinal research are less well researched. This study examined the use of beta regression models for analyzing longitudinal HRQL data using two empirical examples with distributional features typically encountered in practice. Methods We used SF-6D utility data from a German older age cohort study and stroke-specific HRQL data from a randomized controlled trial. We described the conceptual differences between mixed and marginal beta regression models and compared both models to the commonly used linear mixed model in terms of overall fit and predictive accuracy. Results At any measurement time, the beta distribution fitted the SF-6D utility data and stroke-specific HRQL data better than the normal distribution. The mixed beta model showed better likelihood-based fit statistics than the linear mixed model and respected the boundedness of the outcome variable. However, it tended to underestimate the true mean at the upper part of the distribution. Adjusted group means from marginal beta model and linear mixed model were nearly identical but differences could be observed with respect to standard errors. Conclusions Understanding the conceptual differences between mixed and marginal beta regression models is important for their proper use in the analysis of longitudinal HRQL data. Beta regression fits the typical distribution of HRQL data better than linear mixed models, however, if focus is on estimating group mean scores rather than making individual predictions, the two methods might not differ substantially.

  14. Application of a simple, affordable quality metric tool to colorectal, upper gastrointestinal, hernia, and hepatobiliary surgery patients: the HARM score.

    Science.gov (United States)

    Brady, Justin T; Ko, Bona; Hohmann, Samuel F; Crawshaw, Benjamin P; Leinicke, Jennifer A; Steele, Scott R; Augestad, Knut M; Delaney, Conor P

    2018-06-01

    Quality is the major driver for both clinical and financial assessment. There remains a need for simple, affordable, quality metric tools to evaluate patient outcomes, which led us to develop the HospitAl length of stay, Readmission and Mortality (HARM) score. We hypothesized that the HARM score would be a reliable tool to assess patient outcomes across various surgical specialties. From 2011 to 2015, we identified colorectal, hepatobiliary, upper gastrointestinal, and hernia surgery admissions using the Vizient Clinical Database. Individual and hospital HARM scores were calculated from length of stay, 30-day readmission, and mortality rates. We evaluated the correlation of HARM scores with complication rates using the Clavien-Dindo classification. We identified 525,083 surgical patients: 206,981 colorectal, 164,691 hepatobiliary, 97,157 hernia, and 56,254 upper gastrointestinal. Overall, 53.8% of patients were admitted electively with a mean HARM score of 2.24; 46.2% were admitted emergently with a mean HARM score of 1.45 (p  4 (p  4, complication rates were 9.3, 23.2, 38.8, and 71.6%, respectively. There was a similar trend for increasing HARM score in emergent admissions as well. For all surgical procedure categories, increasing HARM score, with and without risk adjustment, correlated with increasing severity of complications by Clavien-Dindo classification. The HARM score is an easy-to-use quality metric that correlates with increasing complication rates and complication severity across multiple surgical disciplines when evaluated on a large administrative database. This inexpensive tool could be adopted across multiple institutions to compare the quality of surgical care.

  15. Food-based diet quality score in relation to depressive symptoms in young and middle-aged Japanese women.

    Science.gov (United States)

    Sakai, Hiroka; Murakami, Kentaro; Kobayashi, Satomi; Suga, Hitomi; Sasaki, Satoshi

    2017-06-01

    Only a few studies have focused on the association between overall diet, rather than intakes of individual nutrients or foods, and depressive symptoms in Japanese. This cross-sectional study examined associations between a diet quality score and depressive symptoms in 3963 young (age 18 years) and 3833 middle-aged (mean age 47·9 (sd 4·2) years) Japanese women. Dietary information was collected using a diet history questionnaire. A previously developed diet quality score was computed mainly based on the Japanese Food Guide Spinning Top. The prevalence of depressive symptoms was 22·0 % for young women and 16·8 % for middle-aged women, assessed as a Center for Epidemiologic Studies Depression (CES-D) score ≥23 and ≥19, respectively. As expected, the diet quality score was associated positively with intakes of 'grain dishes', 'vegetable dishes', 'fish and meat dishes', 'milk' and 'fruits' and inversely with intakes of energy from 'snacks, confection and beverages' and Na from seasonings. After adjustment for potential confounders, OR for depressive symptoms in the highest v. lowest quintiles of the diet quality score was 0·65 (95 % CI 0·50, 0·84) in young women (P for trend=0·0005). In middle-aged women, the corresponding value was 0·59 (95 % CI 0·45, 0·78) (P for trenddiet quality and CES-D scores were treated as continuous variables also showed inverse associations. In conclusion, this cross-sectional study showed that a higher diet quality score was associated with a lower prevalence of depressive symptoms in young and middle-aged Japanese women. Prospective studies are needed to confirm a public health relevance of this finding.

  16. Evaluation of methodologies for assessing the overall diet: dietary quality scores and dietary pattern analysis.

    Science.gov (United States)

    Ocké, Marga C

    2013-05-01

    This paper aims to describe different approaches for studying the overall diet with advantages and limitations. Studies of the overall diet have emerged because the relationship between dietary intake and health is very complex with all kinds of interactions. These cannot be captured well by studying single dietary components. Three main approaches to study the overall diet can be distinguished. The first method is researcher-defined scores or indices of diet quality. These are usually based on guidelines for a healthy diet or on diets known to be healthy. The second approach, using principal component or cluster analysis, is driven by the underlying dietary data. In principal component analysis, scales are derived based on the underlying relationships between food groups, whereas in cluster analysis, subgroups of the population are created with people that cluster together based on their dietary intake. A third approach includes methods that are driven by a combination of biological pathways and the underlying dietary data. Reduced rank regression defines linear combinations of food intakes that maximally explain nutrient intakes or intermediate markers of disease. Decision tree analysis identifies subgroups of a population whose members share dietary characteristics that influence (intermediate markers of) disease. It is concluded that all approaches have advantages and limitations and essentially answer different questions. The third approach is still more in an exploration phase, but seems to have great potential with complementary value. More insight into the utility of conducting studies on the overall diet can be gained if more attention is given to methodological issues.

  17. The sum of friends’ and lovers’ self-control scores predicts relationship quality

    NARCIS (Netherlands)

    Vohs, K.D.; Finkenauer, C.; Baumeister, R.F.

    2011-01-01

    What combination of partners' trait self-control levels produces the best relationship outcomes? The authors tested three hypotheses-complementarity (large difference in trait self-control scores), similarity (small difference in self-control scores), and totality (large sum of self-control

  18. Incorporating Learning Characteristics into Automatic Essay Scoring Models: What Individual Differences and Linguistic Features Tell Us about Writing Quality

    Science.gov (United States)

    Crossley, Scott A.; Allen, Laura K.; Snow, Erica L.; McNamara, Danielle S.

    2016-01-01

    This study investigates a novel approach to automatically assessing essay quality that combines natural language processing approaches that assess text features with approaches that assess individual differences in writers such as demographic information, standardized test scores, and survey results. The results demonstrate that combining text…

  19. Identification of the optimal donor quality scoring system and measure of early renal function in kidney transplantation.

    LENUS (Irish Health Repository)

    Moore, Jason

    2009-02-27

    The early identification of kidney allografts at risk of later dysfunction has implications for clinical practice. Donor quality scoring systems (preoperative) and measures of early allograft function (first week postoperative) have previously shown practical utility. This study aimed to determine the optimal parameter(s) (preoperative and postoperative) with greatest predictive power for the development of subsequent allograft dysfunction.

  20. SF-36 total score as a single measure of health-related quality of life: Scoping review.

    Science.gov (United States)

    Lins, Liliane; Carvalho, Fernando Martins

    2016-01-01

    According to the 36-Item Short Form Health Survey questionnaire developers, a global measure of health-related quality of life such as the "SF-36 Total/Global/Overall Score" cannot be generated from the questionnaire. However, studies keep on reporting such measure. This study aimed to evaluate the frequency and to describe some characteristics of articles reporting the SF-36 Total/Global/Overall Score in the scientific literature. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses method was adapted to a scoping review. We performed searches in PubMed, Web of Science, SCOPUS, BVS, and Cochrane Library databases for articles using such scores. We found 172 articles published between 1997 and 2015; 110 (64.0%) of them were published from 2010 onwards; 30.0% appeared in journals with Impact Factor 3.00 or greater. Overall, 129 (75.0%) out of the 172 studies did not specify the method for calculating the "SF-36 Total Score"; 13 studies did not specify their methods but referred to the SF-36 developers' studies or others; and 30 articles used different strategies for calculating such score, the most frequent being arithmetic averaging of the eight SF-36 domains scores. We concluded that the "SF-36 Total/Global/Overall Score" has been increasingly reported in the scientific literature. Researchers should be aware of this procedure and of its possible impacts upon human health.

  1. [Results of applying a paediatric early warning score system as a healthcare quality improvement plan].

    Science.gov (United States)

    Rivero-Martín, M J; Prieto-Martínez, S; García-Solano, M; Montilla-Pérez, M; Tena-Martín, E; Ballesteros-García, M M

    2016-06-01

    The aims of this study were to introduce a paediatric early warning score (PEWS) into our daily clinical practice, as well as to evaluate its ability to detect clinical deterioration in children admitted, and to train nursing staff to communicate the information and response effectively. An analysis was performed on the implementation of PEWS in the electronic health records of children (0-15 years) in our paediatric ward from February 2014 to September 2014. The maximum score was 6. Nursing staff reviewed scores >2, and if >3 medical and nursing staff reviewed it. Monitoring indicators: % of admissions with scoring; % of complete data capture; % of scores >3; % of scores >3 reviewed by medical staff, % of changes in treatment due to the warning system, and number of patients who needed Paediatric Intensive Care Unit (PICU) admission, or died without an increased warning score. The data were collected from all patients (931) admitted. The scale was measured 7,917 times, with 78.8% of them with complete data capture. Very few (1.9%) showed scores >3, and 14% of them with changes in clinical management (intensifying treatment or new diagnostic tests). One patient (scored 2) required PICU admission. There were no deaths. Parents or nursing staff concern was registered in 80% of cases. PEWS are useful to provide a standardised assessment of clinical status in the inpatient setting, using a unique scale and implementing data capture. Because of the lack of severe complications requiring PICU admission and deaths, we will have to use other data to evaluate these scales. Copyright © 2016 SECA. Published by Elsevier Espana. All rights reserved.

  2. Predicting automatic speech recognition performance over communication channels from instrumental speech quality and intelligibility scores

    NARCIS (Netherlands)

    Gallardo, L.F.; Möller, S.; Beerends, J.

    2017-01-01

    The performance of automatic speech recognition based on coded-decoded speech heavily depends on the quality of the transmitted signals, determined by channel impairments. This paper examines relationships between speech recognition performance and measurements of speech quality and intelligibility

  3. Diet Quality Scores and Prediction of All-Cause, Cardiovascular and Cancer Mortality in a Pan-European Cohort Study.

    Directory of Open Access Journals (Sweden)

    Camille Lassale

    Full Text Available Scores of overall diet quality have received increasing attention in relation to disease aetiology; however, their value in risk prediction has been little examined. The objective was to assess and compare the association and predictive performance of 10 diet quality scores on 10-year risk of all-cause, CVD and cancer mortality in 451,256 healthy participants to the European Prospective Investigation into Cancer and Nutrition, followed-up for a median of 12.8y. All dietary scores studied showed significant inverse associations with all outcomes. The range of HRs (95% CI in the top vs. lowest quartile of dietary scores in a composite model including non-invasive factors (age, sex, smoking, body mass index, education, physical activity and study centre was 0.75 (0.72-0.79 to 0.88 (0.84-0.92 for all-cause, 0.76 (0.69-0.83 to 0.84 (0.76-0.92 for CVD and 0.78 (0.73-0.83 to 0.91 (0.85-0.97 for cancer mortality. Models with dietary scores alone showed low discrimination, but composite models also including age, sex and other non-invasive factors showed good discrimination and calibration, which varied little between different diet scores examined. Mean C-statistic of full models was 0.73, 0.80 and 0.71 for all-cause, CVD and cancer mortality. Dietary scores have poor predictive performance for 10-year mortality risk when used in isolation but display good predictive ability in combination with other non-invasive common risk factors.

  4. Free Dietary Choice and Free-Range Rearing Improve the Product Quality, Gait Score, and Microbial Richness of Chickens

    Directory of Open Access Journals (Sweden)

    Siyu Chen

    2018-06-01

    Full Text Available Poultry welfare has been extensively studied; however, there is a lack of rigorous scientific knowledge relating to the different aspects of welfare factors and how this may contribute to the production quantity and product quality as well as the welfare of chickens. Therefore, we conducted an integrated study to compare welfare factors in chickens by providing free dietary choice under cage rearing, and further comparing cage rearing with free-range rearing. One hundred chickens each were allocated to a cage rearing group with conventional feeding (CC, a cage rearing group with free dietary choice of mealworms (FDM, a cage rearing group with free dietary choice of mealworms and fresh grass (FDMG, and a free-range rearing system group with free dietary choice of mealworms and fresh grass (FRMG. Results showed that under cage rearing, free dietary choice contributed to better meat quality and gait score, higher values of blood platelets, and a richer gut microbial composition, but poorer egg production than CC chickens. As compared to FDMG, FRMG chickens showed better meat quality, gait score, and feather conditions, as well as a richer gut microbial composition; however, they had poorer egg production and a poorer foot pad and foot feather condition. We conclude that free dietary choice and free-range rearing systems improve the product quality, gait score, and microbial richness of chickens.

  5. Trained-user opinion about Welfare Quality measures and integrated scoring of dairy cattle welfare

    DEFF Research Database (Denmark)

    de Graaf, S.; Ampe, B.; Winckler, C.

    2017-01-01

    important by trained users (e.g., measures relating to drinkers) had the highest influence on the WQ overall welfare categorization. Conversely, measures rated as most important by the trained users (e.g., lameness and mortality) had a lower effect on the WQ overall category. In addition, trained users were...... conducted an online survey to examine whether trained users' opinions of the WQ protocol for dairy cattle correspond with the integrated scores (criteria, principles, and overall categorization) calculated according to the WQ protocol. First, the trained users' scores (n = 8–15) for reliability and validity...

  6. Interplay of I-TASSER and QUARK for template-based and ab initio protein structure prediction in CASP10.

    Science.gov (United States)

    Zhang, Yang

    2014-02-01

    We develop and test a new pipeline in CASP10 to predict protein structures based on an interplay of I-TASSER and QUARK for both free-modeling (FM) and template-based modeling (TBM) targets. The most noteworthy observation is that sorting through the threading template pool using the QUARK-based ab initio models as probes allows the detection of distant-homology templates which might be ignored by the traditional sequence profile-based threading alignment algorithms. Further template assembly refinement by I-TASSER resulted in successful folding of two medium-sized FM targets with >150 residues. For TBM, the multiple threading alignments from LOMETS are, for the first time, incorporated into the ab initio QUARK simulations, which were further refined by I-TASSER assembly refinement. Compared with the traditional threading assembly refinement procedures, the inclusion of the threading-constrained ab initio folding models can consistently improve the quality of the full-length models as assessed by the GDT-HA and hydrogen-bonding scores. Despite the success, significant challenges still exist in domain boundary prediction and consistent folding of medium-size proteins (especially beta-proteins) for nonhomologous targets. Further developments of sensitive fold-recognition and ab initio folding methods are critical for solving these problems. Copyright © 2013 Wiley Periodicals, Inc.

  7. The ARIA score of allergic rhinitis using mobile technology correlates with quality-of-life

    DEFF Research Database (Denmark)

    Bousquet, J; Arnavielhe, S; Bedbrook, A

    2018-01-01

    Mobile technology has been used to appraise allergic rhinitis control but more data are needed. In order to better assess the importance of mobile technologies in rhinitis control, the ARIA (Allergic Rhinitis and its Impact on Asthma) score ranging from 0 to 4 of the Allergy Diary was compared wi...

  8. Pronuclear scoring as a predictor of embryo quality in in vitro fertilization program.

    Directory of Open Access Journals (Sweden)

    Piotr Jedrzejczak

    2008-04-01

    Full Text Available Many strategies have been proposed for the selection of viable embryos for transfer in human assisted reproduction. These have included morphological scoring criteria for 20, 28, 44 and 68 h after insemination. The embryo selection is based on morphology, degree of fragmentation and development to the 8-cell. All have shown some correlation with implantation. However, the overall success of these methods is still limited, with over 50% of all transferred embryos failing to implant. Pronuclear zygote morphology has gained much attention recently due to its positive value in predicting implantation and pregnancy. This prospective study involved 178 conventional IVF patients only. The key aspects of pronuclear scoring and namely the presence of a cytoplasmic halo were related to day 3 of development and morphology in a retrospective study. The Z-score and the presence/absence of a halo had significant effect on the rate of development on day 3 embryo. Low Z-score result in slow development and poor morphology. The absence of a halo also resulted in slow and poor development, low morphology, increased fragmentation.

  9. Predicting performance and injury resilience from movement quality and fitness scores in a basketball team over 2 years.

    Science.gov (United States)

    McGill, Stuart M; Andersen, Jordan T; Horne, Arthur D

    2012-07-01

    The purpose of this study was to see if specific tests of fitness and movement quality could predict injury resilience and performance in a team of basketball players over 2 years (2 playing seasons). It was hypothesized that, in a basketball population, movement and fitness scores would predict performance scores and that movement and fitness scores would predict injury resilience. A basketball team from a major American university (N = 14) served as the test population in this longitudinal trial. Variables linked to fitness, movement ability, speed, strength, and agility were measured together with some National Basketball Association (NBA) combine tests. Dependent variables of performance indicators (such as games and minutes played, points scored, assists, rebounds, steal, and blocks) and injury reports were tracked for the subsequent 2 years. Results showed that better performance was linked with having a stiffer torso, more mobile hips, weaker left grip strength, and a longer standing long jump, to name a few. Of the 3 NBA combine tests administered here, only a faster lane agility time had significant links with performance. Some movement qualities and torso endurance were not linked. No patterns with injury emerged. These observations have implications for preseason testing and subsequent training programs in an attempt to reduce future injury and enhance playing performance.

  10. Age-Related Differences in Quality of Standing Balance Using a Composite Score

    NARCIS (Netherlands)

    Pasma, J.H.; Bijlsma, A.Y.; van der Bij, M.D.W.; Arendzen, J.H.; Meskers, C.G.M.; Maier, A.B.

    2014-01-01

    Background: Age-related differences in standing balance are not detected by testing the ability to maintain balance. Quality of standing balance might be more sensitive to detect age-related differences. Objective: To study age-related differences in quality of standing balance, center of pressure

  11. Hong Kong men with low incomes have worse health-related quality of life as judged by SF-36 scores.

    Science.gov (United States)

    Ko, G T C; Wai, H P S; Tsang, P C C; Chan, H C K

    2006-10-01

    To analyse the association between income and health-related quality of life using the Medical Outcome Study Short Form 36 (SF-36) Chinese version in Hong Kong Chinese working population. Cross-sectional observation study. A commercial company in Hong Kong. All clerical and administrative staff of a commercial company was invited to participate; 876 of the 1003 staff agreed. The subjects were categorised into three income groups according to monthly income in Hong Kong dollars (low, 10,000-25,000; high, >25,000). The mean age of the 288 men and 588 women was 34.9 (standard deviation, 7.9; median, 34.0; range, 18-71) years. SF-36 scores on health-related quality of life. The distribution of income was 30% in high-, 54.8% in middle-, and 15.2% in low-income groups. Women had similar SF-36 scores among different income groups. In men, for most variables there was a significant positive linear correlation between income and SF-36 scores. Low income is associated with a worse health-related quality of life in Hong Kong Chinese men.

  12. Patients' experiences of the quality of long-term care among the elderly: comparing scores over time

    Directory of Open Access Journals (Sweden)

    Zuidgeest Marloes

    2012-01-01

    Full Text Available Abstract Background Every two years, long-term care organizations for the elderly are obliged to evaluate and publish the experiences of residents, representatives of psychogeriatric patients, and/or assisted-living clients with regard to quality of care. Our hypotheses are that publication of this quality information leads to improved performance, and that organizations with substandard performance will improve more than those whose performance is relatively good. Methods The analyses included organizational units that measured experiences twice between 2007 (t0 and 2009 (t1. Experiences with quality of care were measured with Consumer Quality Index (CQI questionnaires. Besides descriptive analyses (i.e. mean, 5th and 95th percentile, and 90% central range of the 19 CQI indicators and change scores of these indicators were calculated. Differences across five performance groups (ranging from 'worst' to 'best' were tested using an ANOVA test and effect sizes were measured with omega squared (ω2. Results At t0 experiences of residents, representatives, and assisted-living clients were positive on all indicators. Nevertheless, most CQI indicators had improved scores (up to 0.37 change score at t1. Only three indicators showed a minor decline (up to -0.08 change score. Change scores varied between indicators and questionnaires, e.g. they were more profound for the face-to-face interview questionnaire for residents in nursing homes than for the other two mail questionnaires (0.15 vs. 0.05 and 0.04, respectively, possibly due to more variation between nursing homes on the first measurement, perhaps indicating more potential for improvement. A negative relationship was found between prior performance and change, particularly with respect to the experiences of residents (ω2 = 0.16 and assisted-living clients (ω2 = 0.15. However, the relation between prior performance and improvement could also be demonstrated with respect to the experiences reported

  13. [Predictive quality of the injury severity score in the systematic use of cranial MRI].

    Science.gov (United States)

    Woischneck, D; Lerch, K; Kapapa, T; Skalej, M; Firsching, R

    2010-09-01

    The ABBREVIATED INJURY SCORE (AIS) for the head is mostly coded on the basis of cranial computed tomography (CT). It defines, to a large extent, the predictive potency of the INJURY SEVERITY SCORE (ISS). The present study investigates whether the predictive capacity of the ISS can be improved by the systematic use of data from cranial MRI. 167 patients, who had been in a coma for at least 24 hours following trauma, underwent an MRI examination within 8 days. All had been found to have an intracranial injury on initial CT. 49 % had also suffered extracranial injuries. The GLASGOW OUTCOME SCALE (GOS) was determined 6 months post trauma. AIS, ISS and GOS values were rated as ordinal measurements. A contingency table was used as the statistical method of analysis, with a significance assumed as p RISC) score was improved by use of adapted MRI data. If visible brain stem lesions on MRI were coded according to the AIS guidelines, there was a significant increase in the ISS which correlated significantly to the GOS. If the AIS coding was adjusted to the prognostic significance of individual brain stem lesions, there was a further improvement in the prognostic potency of the ISS. The study encourages the inclusion of data obtained from MRI diagnostics in the ISS calculation. There are alternative ways. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Patients with tattoo reactions have reduced quality of life and suffer from itch: Dermatology Life Quality Index and Itch Severity Score measurements.

    Science.gov (United States)

    Hutton Carlsen, K; Serup, J

    2015-02-01

    Tattoos are a trend with increasing side-effects. The burden of local reaction with swelling, itching and discomfort may impel sufferers to consult medical assistance. To assess tattoo reactions and their influence on quality of life and itching by utilizing the Dermatology Life Quality Index (DLQI) scoring system and Itch Severity Scale (ISS). Patients attending the 'Tattoo Clinic' at Bispebjerg University Hospital, Denmark with tattoo problems spanning more than 3 months were invited. Forty patients participated during September-November 2012. Patients attending their routine consultations completed the ISS and DLQI questionnaires. Patients with tattoo reactions experienced reduced quality of life, DLQI score 7.4 and were burdened by itch, ISS score 7.2. Both DLQI and ISS results attained the level of discomfort of known skin diseases such as psoriasis, pruritus and eczema albeit the typical tattooed affected areas are smaller. Sufferers of tattoo reactions have reduced quality of life and are often burdened by itching attaining the level of other cumbersome afflictions recognized as dermatological diseases associated with itch. Tattoo reactions warrant diagnosis and treatment with same professional intent shared with other skin diseases. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Association between diet-quality scores, adiposity, total cholesterol and markers of nutritional status in european adults: Findings from the Food4Me study

    NARCIS (Netherlands)

    Fallaize, R.; Livingstone, K.M.; Celis-Morales, C.; Macready, A.L.; San-Cristobal, R.; Navas-Carretero, S.; Marsaux, C.F.M.; O’Donovan, C.B.; Kolossa, S.; Moschonis, G.; Walsh, M.C.; Gibney, E.R.; Brennan, L.; Bouwman, J.; Manios, Y.; Jarosz, M.; Martinez, J.A.; Daniel, H.; Saris, W.H.M.; Gundersen, T.E.; Drevon, C.A.; Gibney, M.J.; Mathers, J.C.; Lovegrove, J.A.

    2018-01-01

    Diet-quality scores (DQS), which are developed across the globe, are used to define adherence to specific eating patterns and have been associated with risk of coronary heart disease and type-II diabetes. We explored the association between five diet-quality scores (Healthy Eating Index, HEI;

  16. Health related quality of life among myocardial infarction survivors in the United States: a propensity score matched analysis.

    Science.gov (United States)

    Mollon, Lea; Bhattacharjee, Sandipan

    2017-12-04

    Little is known regarding the health-related quality of life among myocardial infarction (MI) survivors in the United States. The purpose of this population-based study was to identify differences in health-related quality of life domains between MI survivors and propensity score matched controls. This retrospective, cross-sectional matched case-control study examined differences in health-related quality of life (HRQoL) among MI survivors of myocardial infarction compared to propensity score matched controls using data from the 2015 Behavioral Risk Factor Surveillance System (BRFSS) survey. Propensity scores were generated via logistic regression for MI survivors and controls based on gender, race/ethnicity, age, body mass index (BMI), smoking status, and comorbidities. Chi-square tests were used to compare differences between MI survivors to controls for demographic variables. A multivariate analysis of HRQoL domains estimated odds ratios. Life satisfaction, sleep quality, and activity limitations were estimated using binary logistic regression. Social support, perceived general health, perceived physical health, and perceived mental health were estimated using multinomial logistic regression. Significance was set at p 15 days in the month (AOR = 1.63, 95% CI: 1.46-1.83) and poor mental health >15 days in the month (AOR = 1.25, 95% CI: 1.07-1.46) compared to matched controls. There was no difference in survivors compared to controls in level of emotional support (rarely/never: AOR = 0.75, 95% CI: 0.48-1.18; sometimes: AOR = 0.73, 95% CI: 0.41-1.28), hours of recommended sleep (AOR = 1.14, 95% CI: 0.94-1.38), or life satisfaction (AOR = 1.62, 95% CI: 0.99-2.63). MI survivors experienced lower HRQoL on domains of general health, physical health, daily activity, and mental health compared to the general population.

  17. Interobserver agreement and performance score comparison in quality control using a breast phantom: screen-film mammography vs computed radiography

    International Nuclear Information System (INIS)

    Shimamoto, Kazuhiro; Ikeda, Mitsuru; Satake, Hiroko; Ishigaki, Satoko; Sawaki, Akiko; Ishigaki, Takeo

    2002-01-01

    Our objective was to evaluate interobserver agreement and to compare the performance score in quality control of screen-film mammography and computed radiography (CR) using a breast phantom. Eleven radiologists interpreted a breast phantom image (CIRS model X) by four viewing methods: (a) original screen-film; (b) soft-copy reading of the digitized film image; (c) hard-copy reading of CR using an imaging plate; and (d) soft-copy reading of CR. For the soft-copy reading, a 17-in. CRT monitor (1024 x 1536 x 8 bits) was used. The phantom image was evaluated using a scoring system outlined in the instruction manual, and observers judged each object using a three-point rating scale: (a) clearly seen; (b) barely seen; and (c) not seen. For statistical analysis, the kappa statistic was employed. For ''mass'' depiction, interobserver agreement using CR was significantly lower than when using screen-film (p<0.05). There was no significant difference in the kappa value for detecting ''microcalcification''; however, the performance score of ''microcalcification'' on CR hard-copy was significantly lower than on the other three viewing methods (p<0.05). Viewing methods (film or CR, soft-copy or hard-copy) could affect how the phantom image is judged. Paying special attention to viewing conditions is recommended for quality control of CR mammograms. (orig.)

  18. Clinical observation on scores of anxiety, depression and quality of life for advanced gastrointestinal carcinoma patients with palliation intervention therapy

    International Nuclear Information System (INIS)

    Chen Yue; Jiang Tinghui; Jiang Yongxing; Sun Xianjun

    2007-01-01

    Objective: To evaluate the influence of palliative intervention therapy on advanced gastrointestinal carcinoma patients with depression and anxiety before and after the treatment. Methods: 56 advanced gastrointestinal carcinoma patients were selected and treated with intra-arterial perfusion chemotherapy or intra-arterial perfusion chemotherapy with embolization. Curative effects were assessed with the SDS, SAS and FACT-G before and after the treatment. In addition, all patients took self-assessment with SCL-90, comparing with the Chinese norms. Results: SCL-90 scores including the somatization agent, depression agent, and anxiety agent scores of the advanced gastrointestinal carcinoma were higher than those of Chinese norms, with significant difference (P<0.05). After palliative intervention therapy, the scores of SDS and SAS were lower than those before the palliative intervention therapy with significant difference (P< 0.05); and furthermore with an obvious improvement in the scores of FACT-G (P<0.05). Conclusion: Palliative intervention therapy for advanced gastrointestinal carcinoma patients can improve the complaints of depression anxiety and quality of life. (authors)

  19. Longitudinal Prediction of Quality-of-Life Scores and Locomotion in Individuals With Traumatic Spinal Cord Injury.

    Science.gov (United States)

    Hiremath, Shivayogi V; Hogaboom, Nathan S; Roscher, Melissa R; Worobey, Lynn A; Oyster, Michelle L; Boninger, Michael L

    2017-12-01

    To examine (1) differences in quality-of-life scores for groups based on transitions in locomotion status at 1, 5, and 10 years postdischarge in a sample of people with spinal cord injury (SCI); and (2) whether demographic factors and transitions in locomotion status can predict quality-of-life measures at these time points. Retrospective case study of the National SCI Database. Model SCI Systems Centers. Individuals with SCI (N=10,190) from 21 SCI Model Systems Centers, identified through the National SCI Model Systems Centers database between the years 1985 and 2012. Subjects had FIM (locomotion mode) data at discharge and at least 1 of the following: 1, 5, or 10 years postdischarge. Not applicable. FIM-locomotion mode; Severity of Depression Scale; Satisfaction With Life Scale; and Craig Handicap Assessment and Reporting Technique. Participants who transitioned from ambulation to wheelchair use reported lower participation and life satisfaction, and higher depression levels (P.05) or life satisfaction (P>.05) compared with those who transitioned from wheelchair to ambulation. Demographic factors and locomotion transitions predicted quality-of-life scores at all time points (P<.05). The results of this study indicate that transitioning from ambulation to wheelchair use can negatively impact psychosocial health 10 years after SCI. Clinicians should be aware of this when deciding on ambulation training. Further work to characterize who may be at risk for these transitions is needed. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  20. Patient satisfaction scores and their relationship to hospital website quality measures.

    Science.gov (United States)

    Ford, Eric W; Huerta, Timothy R; Diana, Mark L; Kazley, Abby Swanson; Menachemi, Nir

    2013-01-01

    Hospitals and health systems are using web-based and social media tools to market themselves to consumers with increasingly sophisticated strategies. These efforts are designed to shape the consumers' expectations, influence their purchase decisions, and build a positive reputation in the marketplace. Little is known about how these web-based marketing efforts are taking form and if they have any relationship to consumers' satisfaction with the services they receive. The purpose of this study is to assess if a relationship exists between the quality of hospitals' public websites and their aggregated patient satisfaction ratings. Based on analyses of 1,952 U.S. hospitals, our results show that website quality is significantly and positively related to patients' overall rating of the hospital and their intention to recommend the facility to others. The potential for web-based information sources to influence consumer behavior has important implications for policymakers, third-party payers, health care providers, and consumers.

  1. Heteromer score – using internal standards to assess the quality of proteomic data

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, Adelina; Wrzesinski, Krzysztof; Fey, S. J.

    2014-01-01

    of the method used to collect the data, requires no special sample preparation and can be used retrospectively on old datasets. It can be used for quality control, to indicate when a change becomes significant or identify complexes whose stoichiometry has been perturbed during the experiment....... of the analytical approach used. The abundance of one subunit in a heterodimer is plotted against the abundance of the other, and this is repeated for all subunits in all heteromers found in the data set. The correlation coefficient obtained (the “heteromer score”) is a new bioinformatic tool which is independent...

  2. The Image Quality of a Digital Chest X-Ray Radiography System: Comparison of Quantitative Image Quality Analysis and Radiologists' Visual Scoring

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Ho [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Darl; Kim, Won Taek; Kim, Yong Ho; Ki, Yong Kan; Kim, DFong Hyun; Lee, Ju Hee; Kim, Dong Won [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Jeon, Ho Sang [Reserach Institue for Convergence of Biomedical Science and Technology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of)

    2011-11-15

    To evaluate the performance of imaging devices, which should be periodically monitored to maintain high quality images to the radiologists. Additionally, this evaluation may prevent patients from radiation over-exposure. The most suitable engineering standard for imaging performance evaluation of digital X-ray thoracic images was determined. IEC 62220-1 standards were used to evaluate the performance of the images. In succession, the visibilities of overall image, pneumothorax, and humerus head in anthropomorphic thoracic phantom images were used to evaluate the image qualities by radiologists. The rank correlation coefficient (p) of visual scoring by radiologists with system spatial resolution is not meaningful (p-value, p = 0.295), but is significant with image noise (p-value, p -0.9267). Finally, the noise equivalent quanta (NEQ) presents a high rank correlation for visual scoring of radiologists (p-value, p = 0.9320). Image quality evaluation of radiologists were mainly affected by imaging noise. Hence, the engineered standard for evaluating image noise is the most important index to effectively monitor the performance of X-ray images. Additionally, the NEQ can be used to evaluate the performance of radiographic systems, because it theoretically corresponds to the synthetic image quality of systems.

  3. Diet quality of Italian yogurt consumers: an application of the probability of adequate nutrient intake score (PANDiet).

    Science.gov (United States)

    Mistura, Lorenza; D'Addezio, Laura; Sette, Stefania; Piccinelli, Raffaela; Turrini, Aida

    2016-01-01

    The diet quality in yogurt consumers and non-consumers was evaluated by applying the probability of adequate nutrient intake (PANDiet) index to a sample of adults and elderly from the Italian food consumption survey INRAN SCAI 2005-06. Overall, yogurt consumers had a significantly higher mean intake of energy, calcium and percentage of energy from total sugars whereas the mean percentage of energy from total fat, saturated fatty acid and total carbohydrate were significantly (p yogurt consumers than in non-consumers, (60.58 ± 0.33 vs. 58.58 ± 0.19, p yogurt consumers. The items of calcium, potassium and riboflavin showed the major percentage variation between consumers and non-consumers. Yogurt consumers were more likely to have adequate intakes of vitamins and minerals, and a higher quality score of the diet.

  4. Addressing Opioid-Associated Constipation Using Quality Oncology Practice Initiative Scores and Plan-Do-Study-Act Cycles.

    Science.gov (United States)

    Kaur, Varinder; Haider, Sajjad; Sasapu, Appalanaidu; Mehta, Paulette; Arnaoutakis, Konstantinos; Makhoul, Issam

    2017-01-01

    Using the Quality Oncology Practice Initiative, an affiliate program of ASCO, we outlined opioid-associated constipation (OAC) as a subject in need of quality improvement (QI) in our fellowship program at the University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System. We initiated a fellow-led QI project to advance the quality of patient care and provide a valuable avenue for QI training of young physicians. Fellows organized meetings with all stakeholders, addressed the scope of the problem, and devised strategies for OAC management. Monthly meetings were organized using Plan-Do-Study-Act principles. Mandatory check boxes were inserted into our electronic medical record templates to remind all physicians to identify patients on opioid medications and assess and address OAC. Final chart audit and patient satisfaction surveys were performed 6 months after project initiation. Assessment of OAC improved from 52% at baseline to 92% ( P < .003). This improvement corresponded with high patient satisfaction scores, with 90% of surveyed patients reporting adequate management of their constipation. In this QI initiative, we showed that participation in ASCO's Quality Oncology Practice Initiative helps identify areas in need of QI, and such fellow-led QI projects can serve as models for QI training of young physicians.

  5. Correlation between Family APGAR scores and health-related quality of life of Filipino elderly patients with knee osteoarthritis.

    Science.gov (United States)

    Lim, Anne T C; Manching, James; Penserga, Ester G

    2012-08-01

    This study aims to describe the clinical profile of Filipino patients with knee osteoarthritis (OA) and correlate their health-related quality of life (HrQoL) with perceived family support. This is a cross-sectional, analytical study of patients seen at the Philippine General Hospital Arthritis Clinic diagnosed with knee OA using the American College of Rheumatology classification criteria. Questionnaires for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) v.3.1 and Family APGAR (Adaptation, Partnership, Growth, Affection and Resolve) were self-administered. Pearson's correlation, analysis of variance and Bonferroni tests were applied. Ninety patients with 3 : 1 female-to-male ratio, mean age of 70.14 years qualified for the study. Mean body mass index was 23.3. Mean duration of symptoms was 5.9 years. Fifty-three considered their family to be highly functional, 28 moderately dysfunctional and nine severely dysfunctional. Analysis showed that Family APGAR is moderately and inversely correlated with pain (r = -0.3373; P = 0.0002), stiffness (r = -0.3642; P = 0.0004), function (r = -0.3646; P = 0.0004) and total WOMAC scores (r = -0.3880; P = 0.0002). Likewise, there were significant differences of total WOMAC scores in the pain, stiffness and function subscales (P = 0.0076, P = 0.0032, P = 0.0165 and P = 0.0159, respectively) between patients in highly functional and severely dysfunctional families, and between highly and moderately functional families. As Family APGAR scores increased, there was significant decrease in all WOMAC subscales. We described the clinical profile of 90 elderly patients with knee OA and the relationship of HrQoL to Family APGAR scores. This paper concludes that higher Family APGAR scores in this population correlated with better HrQoL. © 2012 The Authors International Journal of Rheumatic Diseases © 2012 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  6. Low quality of life scores in school children with attention deficit-hyperactivity disorder related to anxiety

    Directory of Open Access Journals (Sweden)

    Elizabeth Zambrano-Sánchez

    2012-03-01

    Full Text Available OBJECTIVE: Attention deficit hyperactivity disorder (ADHD is an alteration that begins early in infancy and whose cardinal symptoms are inattention, hyperactivity and impulsivity. There are few studies for specific tests to measure Quality of Life (QoL in children with ADHD. METHODS: We evaluated QoL of 120 children from 7-12 years of age with ADHD and of a group of 98 healthy control children. To measure QoL, we utilized the Questionnaire of Quality of Life for Children in Pictures (AutoQuestionnaire Qualité de Vie Enfant Imagé, AUQUEI. We evaluated anxiety in children by the Children´s Manifest Anxiety Scale-Revisited (CMAS-R. We compared results among groups and employed the calculation of correlation between the AUQUEI questionnaire and the CMAS-R scale. RESULTS: The total average of the AUQUEI questionnaire in children with ADHD was 45.2, while in the control group it was 54.3 (p<0.05. We also observed significant differences between the control group and groups of children with ADHD in the CMAS-R scale. We found significant correlations between AUQUEI questionnaire and CMAS-R scale. CONCLUSION: The main result was to the disclosure that low QoL scores in ADHD children was anxiety-related.

  7. Low quality of life scores in school children with attention deficit-hyperactivity disorder related to anxiety.

    Science.gov (United States)

    Zambrano-Sánchez, Elizabeth; Martínez-Cortés, José A; del Río-Carlos, Yolanda; Dehesa-Moreno, Minerva; Poblano, Adrián

    2012-03-01

    Attention deficit hyperactivity disorder (ADHD) is an alteration that begins early in infancy and whose cardinal symptoms are inattention, hyperactivity and impulsivity. There are few studies for specific tests to measure Quality of Life (QoL) in children with ADHD. We evaluated QoL of 120 children from 7-12 years of age with ADHD and of a group of 98 healthy control children. To measure QoL, we utilized the Questionnaire of Quality of Life for Children in Pictures (AutoQuestionnaire Qualité de Vie Enfant Imagé, AUQUEI). We evaluated anxiety in children by the Children´s Manifest Anxiety Scale-Revisited (CMAS-R). We compared results among groups and employed the calculation of correlation between the AUQUEI questionnaire and the CMAS-R scale. The total average of the AUQUEI questionnaire in children with ADHD was 45.2, while in the control group it was 54.3 (pCMAS-R scale. We found significant correlations between AUQUEI questionnaire and CMAS-R scale. The main result was to the disclosure that low QoL scores in ADHD children was anxiety-related.

  8. Ab initio vel ex eventu

    Science.gov (United States)

    Thiessen, P. A.; Treder, H.-J.

    Der gegenwärtige Stand der physikalischen Erkenntnis, in Sonderheit die Atomistik und die Quantentheorie, ermöglicht (in wohldefinierten Energie-Bereichen) eine ab initio-Berechnung aller physikalischen und chemischen Prozesse und Strukturen. Die Schrödinger-Gleichung erlaubt zusammen mit den Prinzipien der Quantenstatistik (Pauli-Prinzip) aus dem Planckschen Wirkungsquantum h und den atomischen Konstanten die Berechnung aller Energieumsätze, Zeitabläufe etc., die insbesondere die chemische Physik bestimmen. Die Rechenresultate gelten auch quantitativ bis auf die unvermeidliche Stochastik.Die ab initio-Berechnungen korrespondieren einerseits und sind andererseits komplementär zu den auf den Methoden der theoretischen Chemie und der klassischen Thermodynamik beruhenden Ergebnissen ex eventu. Die theoretische Behandlung ab initio führt zu mathematischen Experimenten, die die Laboratoriums-Experimente ergänzen oder auch substituieren.Translated AbstractAb initio vel ex eventuThe present state of physical knowledge, in peculiar atomistic and quantum theory, makes an ab initio calculation of all physical and chemical processes and structures possible (in well defined reaches of energy). The Schrödinger equation together with the principles of quantum statistics (Pauli principle) permits from the Planck and atomistic constants to calculate all exchanges of energy, courses of time, etc. which govern chemical physics. The calculated results are valid even quantitatively apart from the unavoidable stochastics.These ab initio calculations on the one hand correspond and are on the other complimentary to results ex eventu based on the methods of theoretical chemistry and classical thermodynamics. Theoretical treatment ab initio leads to mathematical experiments which add to or even substitute experiments in the laboratory.

  9. The relationship between observer-based toxicity scoring and patient assessed symptom severity after treatment for head and neck cancer. A correlative cross sectional study of the DAHANCA toxicity scoring system and the EORTC quality of life questionnaires

    International Nuclear Information System (INIS)

    Jensen, Kenneth; Bonde Jensen, Anders; Grau, Cai

    2006-01-01

    Background and purpose: Morbidity is an important issue in cancer research. The observer-based toxicity scoring system used by DAHANCA (the Danish head and neck cancer study group) has proved itself sensitive to differences in toxicity in a large randomised study, but like other toxicity scoring systems it has not been formally validated. Conversely, the EORTC quality of life questionnaire (QLQ) has been validated as a tool for collecting information about the consequences of disease and treatment on the well being of cancer patients. The purpose of this study was to examine the relationship between the two methods of side effect recording. Patients and methods: One hundred and sixteen recurrence free patients with laryngeal (n=44), pharyngeal (n=34) and oral cavity (n=38) cancer attending follow-up after radiotherapy (n=83) or surgery (n=33) completed EORTC C30, the core questionnaire concerning general symptoms and function and EORTC H and N35 the head and neck specific questionnaire. The attending physicians in the follow-up clinic evaluated and recorded DAHANCA toxicity scores on the same patients. Results: The DAHANCA toxicity scoring system and the EORTC QLQ correlated with several clinical endpoints. The conceptually similar endpoints of the two methods correlated significantly. The objective endpoints of the DAHANCA scoring system were only correlated with quality of life endpoints to a very low degree. The DAHANCA toxicity scores had a low sensitivity (0.48-0.74) in detecting equivalent subjective complaints from the questionnaires and the observer-based scoring system severely underestimated patient complaints. A specific patient group where the DAHANCA score had a higher tendency to fail could not be detected. Conclusion: The DAHANCA toxicity score is an effective instrument in assessing objective treatment induced toxicity in head and neck cancer patients but insensitive and non-specific with regard to patient assessed subjective endpoints. This

  10. Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality: A novel statistical approach for quality scoring.

    Science.gov (United States)

    Kooijman, Pieter C; Kok, Sander J; Weusten, Jos J A M; Honing, Maarten

    2016-05-05

    Preparation of samples according to an optimized method is crucial for accurate determination of polymer sample characteristics by Matrix-Assisted Laser Desorption Ionization (MALDI) analysis. Sample preparation conditions such as matrix choice, cationization agent, deposition technique or even the deposition volume should be chosen to suit the sample of interest. Many sample preparation protocols have been developed and employed, yet finding the optimal sample preparation protocol remains a challenge. Because an objective comparison between the results of diverse protocols is not possible, "gut-feeling" or "good enough" is often decisive in the search for an optimum. This implies that sub-optimal protocols are used, leading to a loss of mass spectral information quality. To address this problem a novel analytical strategy based on MALDI imaging and statistical data processing was developed in which eight parameters were formulated to objectively quantify the quality of sample deposition and optimal MALDI matrix composition and finally sum up to an overall quality score of the sample deposition. These parameters can be established in a fully automated way using commercially available mass spectrometry imaging instruments without any hardware adjustments. With the newly developed analytical strategy the highest quality MALDI spots were selected, resulting in more reproducible and more valuable spectra for PEG in a variety of matrices. Moreover, our method enables an objective comparison of sample preparation protocols for any analyte and opens up new fields of investigation by presenting MALDI performance data in a clear and concise way. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The relationship between observer-based toxicity scoring and patient assessed symptom severity after treatment for head and neck cancer. A correlative cross sectional study of the DAHANCA toxicity scoring system and the EORTC quality of life questionnaires

    DEFF Research Database (Denmark)

    Jensen, Kenneth; Bonde Jensen, Anders; Grau, Cai

    2006-01-01

          toxicity scoring systems it has not been formally validated. Conversely,       the EORTC quality of life questionnaire (QLQ) has been validated as a tool       for collecting information about the consequences of disease and treatment       on the well being of cancer patients. The purpose of this study......) completed       EORTC C30, the core questionnaire concerning general symptoms and function       and EORTC H&N35 the head and neck specific questionnaire. The attending       physicians in the follow-up clinic evaluated and recorded DAHANCA toxicity       scores on the same patients. RESULTS: The DAHANCA...... low degree. The       DAHANCA toxicity scores had a low sensitivity (0.48-0.74) in detecting       equivalent subjective complaints from the questionnaires and the       observer-based scoring system severely underestimated patient complaints.       A specific patient group where the DAHANCA score had...

  12. Association between Diet-Quality Scores, Adiposity, Total Cholesterol and Markers of Nutritional Status in European Adults: Findings from the Food4Me Study

    Directory of Open Access Journals (Sweden)

    Rosalind Fallaize

    2018-01-01

    Full Text Available Diet-quality scores (DQS, which are developed across the globe, are used to define adherence to specific eating patterns and have been associated with risk of coronary heart disease and type-II diabetes. We explored the association between five diet-quality scores (Healthy Eating Index, HEI; Alternate Healthy Eating Index, AHEI; MedDietScore, MDS; PREDIMED Mediterranean Diet Score, P-MDS; Dutch Healthy Diet-Index, DHDI and markers of metabolic health (anthropometry, objective physical activity levels (PAL, and dried blood spot total cholesterol (TC, total carotenoids, and omega-3 index in the Food4Me cohort, using regression analysis. Dietary intake was assessed using a validated Food Frequency Questionnaire. Participants (n = 1480 were adults recruited from seven European Union (EU countries. Overall, women had higher HEI and AHEI than men (p < 0.05, and scores varied significantly between countries. For all DQS, higher scores were associated with lower body mass index, lower waist-to-height ratio and waist circumference, and higher total carotenoids and omega-3-index (p trends < 0.05. Higher HEI, AHEI, DHDI, and P-MDS scores were associated with increased daily PAL, moderate and vigorous activity, and reduced sedentary behaviour (p trend < 0.05. We observed no association between DQS and TC. To conclude, higher DQS, which reflect better dietary patterns, were associated with markers of better nutritional status and metabolic health.

  13. The Quality of Toddler Child Care and Cognitive Skills at 24 Months: Propensity Score Analysis Results from the ECLS-B

    Science.gov (United States)

    Ruzek, Erik; Burchinal, Margaret; Farkas, George; Duncan, Greg J.

    2013-01-01

    Over half of the toddlers in the U.S. experience routine nonparental care, but much less is known about early care than about preschool care. This study analyzed 2-year-old child care and child outcome data from the nationally representative ECLS-B sample of children born in 2001. At two-years of age, 51% of children experienced exclusive parental care, 18% relative care, 15% family child care, and 16% center care. More children in nonparental care were in medium quality care (61%) than in high quality (26%) or low quality (13%) care. Low-income children were more likely than non-low income children to be cared for by their parents and, when in care, were more often in lower quality care. The impact of toddler care quality on cognitive skills was estimated using propensity score adjustments to account for potential selection confounds due to family and child characteristics. Children’s cognitive scores were higher in high or medium quality care than in low quality care, but no evidence emerged suggesting that poverty moderated the quality effects. Nevertheless, this suggests that increasing the proportion of low-income children in high quality care could reduce the achievement gap because low-income children are very unlikely to experience high quality care. PMID:24347815

  14. Evaluation of Diabetes Quality of Care Based on a Care Scoring System among People Referring to Diabetes Clinic in Ardabil, 2014

    Directory of Open Access Journals (Sweden)

    J Ataei

    2015-06-01

    Full Text Available Background & objectives: Successful implementation of diabetes care can reduce acute and chronic complications of diabetes. This study was conducted to evaluate the quality of care according to a care scoring system among people with type 2 diabetes referring to the diabetes clinic in Ardabil. Methods: This cross sectional study was conducted in 2014 and a total of 300 people with type 2 diabetes in age range of 20-70 years old were included via convenience sampling. Data were collected by an interviewer using a structured questionnaire and checklist. Each patient was classified according to a quality of care scoring system into 3 categories: ≤10, 15-20, >20. Statistical analysis performed by SPSS v.20 software and descriptive analysis used to display data as frequency tables and graphs. Analytical tests such as ANOVA, Kruskal-Wallis, Chi squared, and fisher exact test were also used to analyze the data. Results: The mean age of patients was 54.13 ± 9.13 and the majority of them were women (72.3%. The mean of BMI and HbA1c was 29.58 ± 4.77 and 8.93± 2.13, respectively. The mean of FBS was 191.18 ± 84.23 and the average length of disease was 7.74±5.89 years. The mean of quality of care score among participants was 23.20±9.99. About one-third of patients (29.7% had a quality care score ≤10, half of them (51% had a score between 15-20, and only 19.35% had a score >20. There was an association between HbA1c, FBS, diastolic blood pressure, cholesterol and LDL with a quality of care score which was statistically significant (p<0.05. Conclusion: In this study there was a gap between the current quality of care of patients and recommended standards. Therefore in order to minimize the current barriers and problems it is recommended to implement an effective interventional program. In addition, using a quality care scoring system is a rapid, easy and valid method for evaluating diabetes quality of care.

  15. Effect of clinical and laboratory parameters on quality of life in celiac patients using celiac disease-specific quality of life scores.

    Science.gov (United States)

    Lee, Jungmin; Clarke, Kofi

    2017-11-01

    Health-related quality of life (HR-QOL) in patients with celiac disease is reduced compared to the general population. We investigated the association between HR-QOL and clinical, laboratory findings using the previously validated CD-QOL (celiac disease-specific quality of life) instrument in patients with celiac disease. To our knowledge, no study has previously explored the relationship between HR-QOL and clinical, laboratory parameters in celiac patients. Patients who received care at the Allegheny Health Network Celiac Center, Pittsburgh, PA were asked to complete the CD-QOL questionnaire. A cross sectional study with predetermined clinical and laboratory parameters was performed. Data collected included IgA anti-tissue transglutaminase (tTG) antibody titers, iron studies, calcium, vitamin A, B12, 25 OH vitamin D, and E levels. Correlation between clinical findings and CD-QOL was also assessed. Seventy-eight out of 124 patients who completed the questionnaire was included in the analysis. Patients with concomitant irritable bowel syndrome (IBS) had significantly reduced HR-QOL with CD-QOL score of 52.4 ± 11.3 vs. 44.6 ± 12.9 in those without IBS (p = .009). There was no difference in HR-QOL in relation to IgA tTG titers or vitamin D levels. Of note, there was a trend towards correlation between higher level of vitamin E and better QOL (r = -0.236, p = .074). Celiac patients with concomitant IBS have reduced HR-QOL. There was no statistically significant association between HR-QOL and laboratory parameters or levels of micronutrients.

  16. Ab initio potential for solids

    DEFF Research Database (Denmark)

    Chetty, N.; Stokbro, Kurt; Jacobsen, Karsten Wedel

    1992-01-01

    . At the most approximate level, the theory is equivalent to the usual effective-medium theory. At all levels of approximation, every term in the total-energy expression is calculated ab initio, that is, without any fitting to experiment or to other calculations. Every step in the approximation procedure can...

  17. Ab-initio ZORA calculations

    NARCIS (Netherlands)

    Faas, S.; Snijders, Jaap; van Lenthe, J.H.; HernandezLaguna, A; Maruani, J; McWeeny, R; Wilson, S

    2000-01-01

    In this paper we present the first application of the ZORA (Zeroth Order Regular Approximation of the Dirac Fock equation) formalism in Ab Initio electronic structure calculations. The ZORA method, which has been tested previously in the context of Density Functional Theory, has been implemented in

  18. The Use of Quality Control and Data Mining Techniques for Monitoring Scaled Scores: An Overview. Research Report. ETS RR-12-20

    Science.gov (United States)

    von Davier, Alina A.

    2012-01-01

    Maintaining comparability of test scores is a major challenge faced by testing programs that have almost continuous administrations. Among the potential problems are scale drift and rapid accumulation of errors. Many standard quality control techniques for testing programs, which can effectively detect and address scale drift for small numbers of…

  19. Reporting health-related quality of life scores to physicians during routine follow-up visits of pediatric oncology patients: Is it effective?

    NARCIS (Netherlands)

    Engelen, Vivian; Detmar, Symone; Koopman, Hendrik; Maurice-Stam, Heleen; Caron, Huib; Hoogerbrugge, Peter; Egeler, R. Maarten; Kaspers, Gertjan; Grootenhuis, Martha

    2012-01-01

    Background The aim of the current study is to investigate the effectiveness of an intervention that provides health-related quality of life (HRQOL) scores of the patient (the QLIC-ON PROfile) to the pediatric oncologist. Procedure. Children with cancer participated in a sequential cohort

  20. Reporting health-related quality of life scores to physicians during routine follow-up visits of pediatric oncology patients: Is it effective?

    NARCIS (Netherlands)

    Engelen, V.; Detmar, S.; Koopman, H.; Maurice-Stam, H.; Caron, H.; Hoogerbrugge, P.; Egeler, R.M.; Kaspers, G.; Grootenhuis, M.

    2012-01-01

    Background: The aim of the current study is to investigate the effectiveness of an intervention that provides health-related quality of life (HRQOL) scores of the patient (the QLIC-ON PROfile) to the pediatric oncologist. Procedure: Children with cancer participated in a sequential cohort

  1. Reliability, construct and criterion validity of the KIDSCREEN-10 score: A short measure for children and adolescents' well-being and health-related quality of life

    NARCIS (Netherlands)

    Ravens-Sieberer, U.; Erhart, M.; Rajmil, L.; Herdman, M.; Auquier, P.; Bruil, J.; Power, M.; Duer, W.; Abel, T.; Czemy, L.; Mazur, J.; Czimbalmos, A.; Tountas, Y.; Hagquist, C.; Kilroe, J.

    2010-01-01

    Background: To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments. Methods: The child self-report and parent report versions of the KIDSCREEN-10 were tested in a

  2. The Protein Digestibility-Corrected Amino Acid Score (PDCAAS) - A concept for describing protein quality in foods and food ingredients: A critical review

    NARCIS (Netherlands)

    Schaafsma, G.

    2005-01-01

    Protein Digestibility-Corrected Amino Score (PDCAAS) is discussed. PDCAAS is now widely used as a routine assay for protein quality evaluation, replacing the more traditional biological methods [e.g., measurement of the Protein Efficiency Ratio (PER) in rats]. PDCAAS is based on comparison of the

  3. Nutritional Quality of Breakfast and Physical Activity Independently Predict the Literacy and Numeracy Scores of Children after Adjusting for Socioeconomic Status

    Science.gov (United States)

    O'Dea, Jennifer A.; Mugridge, Anna C.

    2012-01-01

    Health-related behaviors [physical activity (PA), nutritional quality of breakfast and sleep]; personal variables (self-esteem, attitudes to PA and gender) and socioeconomic status (SES) (school SES and parental education), were examined in relation to literacy and numeracy scores of 824 grade 3-7 children. Participants completed a questionnaire,…

  4. Self-Evaluation Scores of Hearing Difficulties and Quality of Life Components among Retired Workers with Noise-Related Hearing Loss

    Science.gov (United States)

    MIYAKITA, T.; UEDA, A.; ZUSHO, H.; KUDOH, Y.

    2002-02-01

    This study is intended to clarify the relationships between hearing loss caused both by noise exposure and aging and self-rated scores of hearing disabilities and to elucidate the structure of the quality of life (QOL) determinants and their moderating conditions among retired workers with noise-related hearing loss. The questionnaire consisted of three parts: background questions, the hearing disabilities and handicap scale (HDHS), and questions regarding QOL covering five areas, self-rated health, personal health practice, social support network, life satisfaction, and life events. Two hundred ten retired workers aged 56-65 years old (60·6±1·6) with noise-related hearing loss responded to our questionnaire. All were previously engaged in noise exposed work such as shipbuilding, steel and woodwork. According to the hearing disability score (DIS score), subjects were divided into three groups and comparisons were made of the hearing handicap score (HD score) among those groups. Although groups with a higher DIS score showed a higher HD score, a large individual difference in HD score was observed in each of the three groups with the same DIS score level. The results of multiple regression analysis including two variables (life satisfaction and HD score) as the dependent variables and seven variables as the independent variables showed that the strongest explanatory variable for life satisfaction was social support network, followed by handicaps caused by hearing disabilities, self-rated health and personal health practice. It was demonstrated that hearing disabilities and handicap measured by the Japanese version of the HDHS were directly associated with the deterioration in QOL. Measures of the social support network, life satisfaction, and hearing disabilities and handicaps may assist in the detection of workers who can be targeted for a variety of interventions, such as audiological rehabilitation or the creation of a barrier-free community that is supportive

  5. Designing a Score-Based Method for the Evaluation of the Nutritional Quality of the Gluten-Free Bakery Products and their Gluten-Containing Counterparts.

    Science.gov (United States)

    Morreale, Federico; Angelino, Donato; Pellegrini, Nicoletta

    2018-04-25

    Gluten-free (GF) products are consumed both by individuals with celiac disease and by an increasing number of people with no specific medical needs. Although the technological quality of GF products has been recently improved, their nutritional quality is still scarcely addressed. Moreover, the few published studies report conflicting results, mostly because the information from product nutrition facts is the only considered factor. The aim of the present study was to develop a score-based method for the nutritional evaluation of 134 packaged Italian GF bakery products and to compare it with that of 162 matched gluten-containing (GC) food items. The score included the information from the nutrition facts and the presence/absence of some nutritionally relevant components in the ingredients list. Results indicated an overall low nutritional quality of the considered GF bakery products. Additionally, with the sole exception of GF bread substitutes, there was no difference in nutritional quality between GF and equivalent GC bakery products. Future research and development of GF bakery products may take advantage of this scoring method, as it may represent an easy approach to evaluate their nutritional quality. The present findings do not justify the consumption of packaged GF bakery products by people without any specific medical needs.

  6. Regional Emphysema Score Predicting Overall Survival, Quality of Life, and Pulmonary Function Recovery in Early-Stage Lung Cancer Patients.

    Science.gov (United States)

    Dai, Jie; Liu, Ming; Swensen, Stephen J; Stoddard, Shawn M; Wampfler, Jason A; Limper, Andrew H; Jiang, Gening; Yang, Ping

    2017-05-01

    Pulmonary emphysema is a frequent comorbidity in lung cancer, but its role in tumor prognosis remains obscure. Our aim was to evaluate the impact of the regional emphysema score (RES) on a patient's overall survival, quality of life (QOL), and recovery of pulmonary function in stage I to II lung cancer. Between 1997 and 2009, a total of 1073 patients were identified and divided into two surgical groups-cancer in the emphysematous (group 1 [n = 565]) and nonemphysematous (group 2 [n = 435]) regions-and one nonsurgical group (group 3 [n = 73]). RES was derived from the emphysematous region and categorized as mild (≤5%), moderate (6%-24%), or severe (25%-60%). In group 1, patients with a moderate or severe RES experienced slight decreases in postoperative forced expiratory volume in 1 second, but increases in the ratio of forced expiratory volume in 1 second to forced vital capacity compared with those with a mild RES (p < 0.01); however, this correlation was not observed in group 2. Posttreatment QOL was lower in patients with higher RESs in all groups, mainly owing to dyspnea (p < 0.05). Cox regression analysis revealed that patients with a higher RES had significantly poorer survival in both surgical groups, with adjusted hazard ratios of 1.41 and 1.43 for a moderate RES and 1.63 and 2.04 for a severe RES, respectively; however, this association was insignificant in the nonsurgical group (adjusted hazard ratio of 0.99 for a moderate or severe RES). In surgically treated patients with cancer in the emphysematous region, RES is associated with postoperative changes in lung function. RES is also predictive of posttreatment QOL related to dyspnea in early-stage lung cancer. In both surgical groups, RES is an independent predictor of survival. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  7. A comparison of the nutritional quality of organic and conventional ready-to-eat breakfast cereals based on NuVal scores.

    Science.gov (United States)

    Woodbury, Nancy J; George, Valerie A

    2014-07-01

    To identify whether there were differences in nutritional quality between organic and conventional ready-to-eat breakfast cereals of similar types, based on NuVal scores. The current descriptive study analysed NuVal scores for 829 ready-to-eat breakfast cereals and eighteen different cereal types. ANOVA was used to compare the mean NuVal scores of 723 conventional cereals with those of 106 organic cereals. Ready-to-eat breakfast cereals (n 829) with NuVal scores. Not applicable. There was no significant difference in NuVal scores between conventional (mean 28·4 (sd 13·4)) and organic (mean 30·6 (sd 13·2)) cereal types. Consumers who choose the organic version of a ready-to-eat breakfast cereal believing that nutritional quality is superior may not be making a valid assumption. Public health nutrition educators must help consumers understand that organic cereals are not necessarily more nutritious and their consumption could result in excessive intake of undesirable nutrients, such as fat, sugar and sodium.

  8. Body Movement Music Score – Introduction of a newly developed model for the analysis and description of body qualities, movement and music in music therapy

    Directory of Open Access Journals (Sweden)

    Hanna Agnieszka Skrzypek

    2017-01-01

    Full Text Available Background In music therapy, there is a range of music therapy concepts that, in addition to music, describe and analyse the body and movement. A model that equally examines the body, movement and music has not been developed. The Body Movement Music Score (BMMS is a newly developed and evaluated music therapy model for analysing body qualities, movement, playing style of musical instruments and music and to describe body behaviour and body expression, movement behaviour and movement expression, playing behaviour and musical expression in music therapy treatment. The basis for the development of the Body Movement Music Score was the evaluation of the analytical movement model Emotorics-Emotive Body Movement Mind Paradigm (Emotorics-EBMMP by Yona Shahar Levy for the analysis and description of the emotive-motor behaviour and movement expression of schizophrenic patients in music therapy treatment. Participants and procedure The application of the Body Movement Music Score is presented in a videotaped example from the music therapy treatment of one schizophrenic patient. Results The results of applying the Body Movement Music Score are presented in the form of Body Qualities I Analysis, Body Qualities II Analysis, Movement Analysis, Playing Style Analysis and Music Analysis Profiles. Conclusions The Body Movement Music Score has been developed and evaluated for the music therapy treatment of schizophrenic patients. For the development of the model, a proof of reliability is necessary to verify the reliability and limitations of the model in practice and show that the Body Movement Music Score could be used for both practical and clinical work, for documentation purposes and to impact research in music therapy.

  9. The Mediterranean Diet Score Is More Strongly Associated with Favorable Cardiometabolic Risk Factors over 2 Years Than Other Diet Quality Indexes in Puerto Rican Adults.

    Science.gov (United States)

    Mattei, Josiemer; Sotos-Prieto, Mercedes; Bigornia, Sherman J; Noel, Sabrina E; Tucker, Katherine L

    2017-04-01

    Background: Multiple diet quality scores have been used to evaluate adherence to specific dietary recommendations or to consumption of healthful foods and nutrients. It remains unknown which score can more strongly predict longitudinal changes in cardiometabolic risk factors. Objective: We aimed to determine associations of 5 diet quality scores [AHA diet score (AHA-DS), Dietary Approaches to Stop Hypertension (DASH), Healthy Eating Index (HEI)-2005, Mediterranean diet score (MeDS), and Alternative Healthy Eating Index (AHEI)] with 2-y changes in cardiometabolic risk factors in adults 45-75 y old. Methods: Data from the Boston Puerto Rican Health Study were analyzed ( n = 1194). Diet quality scores were calculated from a baseline-validated food-frequency questionnaire. Multivariable-adjusted, repeated-subjects, mixed-effects models, adjusted for baseline measures, estimated associations between each z score and 14 individual cardiometabolic factors measured at 2 y. Results: MeDS was significantly associated with lower 2-y waist circumference (β coefficient ± SE: -0.52 ± 0.26, P = 0.048); body mass index (BMI; -0.23 ± 0.08, P = 0.005); log-insulin (-0.06 ± 0.02, P = 0.005); log-homeostasis model assessment of insulin resistance (HOMA-IR; -0.05 ± 0.02, P = 0.030), and log-C-reactive protein (-0.13 ± 0.03, P = 0.0002). Similar but weaker associations were observed for the AHEI with BMI, insulin, and HOMA-IR. The AHA-DS was inversely associated with BMI (-0.17 ± 0.08, P = 0.033). Neither the HEI-2005 nor DASH was significantly associated with any variable. Traditional Puerto Rican foods consumed by individuals with high MeDSs included vegetables and meats in homemade soups, orange juice, oatmeal, beans and legumes, fish, whole milk, corn oil, and beer. Conclusions: The MeDS comprises food components and scores associated with a favorable cardiometabolic profile over 2 y in Puerto Rican adults. An overall healthy diet may be particularly beneficial for

  10. Preferred 11 different job rotation types in automotive company and their effects on productivity, quality and musculoskeletal disorders: comparison between subjective and actual scores by workers' age.

    Science.gov (United States)

    Jeon, In Sik; Jeong, Byung Yong; Jeong, Ji Hyun

    2016-10-01

    This study investigates workers' favoured rotation types by their age and compares means between subjective and actual scores on productivity, quality and musculoskeletal disorders (MSDs). The subjects of research were 422 assembly line units in Hyundai Motor Company. The survey of 422 units focused on the workers' preference for 11 different rotation types and subjective scores for each type's perceived benefits, both by the workers' age. Then, actual scores on production-related indices were traced over a five-year period. The results suggest that different rotation types lead to different results in productivity, product quality and MSDs. Workers tend to perceive job rotation as a helpful method to enhance satisfaction, productivity and product quality more so than the actual production data suggests. Job rotation was especially effective in preventing MSDs for workers aged under 45, while its effects were not clear for the workers aged 45 years or older. Practitioner's Summary: This research presents appropriate rotation type for different age groups. Taking workers' age into account, administrators can use the paper's outcomes to select and implement the suitable rotation type to attain specific goals such as enhancing productivity, improving product quality or reducing MSDs.

  11. Classification and Prioritization of Strategic Plans in Balanced Score Card (BSC Model by Fuzzy Quality Function Deployment and Zero-One Goal Programming (ZOGP

    Directory of Open Access Journals (Sweden)

    mehdi pourmostafa

    2012-02-01

    Full Text Available Due to continuous changes in organizational environment, there is no warranty for long term survival in the market. Currently, those organizations can succeed that are agile and able to rapidly respond to environmental requirements. In this research a model has been proposed for applying proper strategies for achieving long term organizational success. The proposed model is an integration of Balanced Score Card (BSC approach, Fuzzy Quality Function Development (FQFD and Zero-One Goal Programming (ZOGP. In fact by BSC, appropriate strategic plans can be designed and prioritized by FQFD. Then, based on multiple objectives and existing problem constraints, feasible strategic plans are identified by ZOGP. Findings imply that decision making techniques can be well utilized in designing BSC through a structured methodology make improvement in all aspects and have a positive influence on organization's performance in long term .   Keywords : B alanced Score Card , Fuzzy Quality Function Development, Zero-One Goal Programming, Strategic plans

  12. [Evaluation of the adjusted amino acid score by digestibility for estimating the protein quality and protein available in food and diets].

    Science.gov (United States)

    Pak, N; Vera, G; Araya, H

    1985-03-01

    The purpose of the present study was to evaluate the amino acid score adjusted by digestibility to estimate protein quality and utilizable protein in foods and diets, considering net protein utilization (NPU) as a biological reference method. Ten foods of vegetable origin and ten of animal origin, as well as eight mixtures of foods of vegetable and animal origin were studied. When all the foods were considered, a positive (r = 0.83) and highly significant correlation (p less than 0.001) between NPU and the amino acid score adjusted by digestibility was found. When the foods were separated according to their origin, this correlation was positive only for the foods of vegetable origin (r = 0.93) and statistically significant (p less than 0.001). Also, only in those foods were similar values found between NPU and amino acid score adjusted by digestibility, as well as in utilizable protein estimated considering both methods. Caution is required to interpret protein quality and utilizable protein values of foods of animal origin and mixtures of foods of vegetable and animal origin when the amino acid score method adjusted by digestibility, or NPU, are utilized.

  13. Composite quality of care scores, electronic health record maturity models, and their associations; preliminary literature review results

    NARCIS (Netherlands)

    Joukes, Erik; de Keizer, Nicolette; Cornet, Ronald

    2013-01-01

    To accurately assess the association between the use of EHR systems and the quality of healthcare we need (composite) measures for quality of healthcare, and a model to measure the maturity of the EHR. This Medline-based literature study therefore focussed on three topics; (1) methods to compose a

  14. Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS).

    Science.gov (United States)

    Mathai, John K; Liu, Yanhong; Stein, Hans H

    2017-02-01

    An experiment was conducted to compare values for digestible indispensable amino acid scores (DIAAS) for four animal proteins and four plant proteins with values calculated as recommended for protein digestibility-corrected amino acid scores (PDCAAS), but determined in pigs instead of in rats. Values for standardised total tract digestibility (STTD) of crude protein (CP) and standardised ileal digestibility (SID) of amino acids (AA) were calculated for whey protein isolate (WPI), whey protein concentrate (WPC), milk protein concentrate (MPC), skimmed milk powder (SMP), pea protein concentrate (PPC), soya protein isolate (SPI), soya flour and whole-grain wheat. The PDCAAS-like values were calculated using the STTD of CP to estimate AA digestibility and values for DIAAS were calculated from values for SID of AA. Results indicated that values for SID of most indispensable AA in WPI, WPC and MPC were greater (P<0·05) than for SMP, PPC, SPI, soya flour and wheat. With the exception of arginine and tryptophan, the SID of all indispensable AA in SPI was greater (P<0·05) than in soya flour, and with the exception of threonine, the SID of all indispensable AA in wheat was less (P<0·05) than in all other ingredients. If the same scoring pattern for children between 6 and 36 months was used to calculate PDCAAS-like values and DIAAS, PDCAAS-like values were greater (P<0·05) than DIAAS values for SMP, PPC, SPI, soya flour and wheat indicating that PDCAAS-like values estimated in pigs may overestimate the quality of these proteins.

  15. Do medical student stress, health, or quality of life foretell step 1 scores? A comparison of students in traditional and revised preclinical curricula.

    Science.gov (United States)

    Tucker, Phebe; Jeon-Slaughter, Haekyung; Sener, Ugur; Arvidson, Megan; Khalafian, Andrey

    2015-01-01

    We explored the theory that measures of medical students' well-being and stress from different types of preclinical curricula are linked with performance on standardized assessment. Self-reported stress and quality of life among sophomore medical students having different types of preclinical curricula will vary in their relationships to USMLE Step 1 scores. Voluntary surveys in 2010 and 2011 compared self-reported stress, physical and mental health, and quality of life with Step 1 scores for beginning sophomore students in the final year of a traditional, discipline-based curriculum and the 1st year of a revised, systems-based curriculum with changed grading system. Wilcoxon rank sum tests and Spearman rank correlations were used to analyze data, significant at p students reported worse physical health, subjective feelings, leisure activities, social relationships and morale, and more depressive symptoms and life stress than traditional curriculum students. However, among curriculum-related stressors, few differences emerged; revised curriculum sophomores reported less stress working with real and standardized patients than traditional students. There were no class differences in respondents' Step 1 scores. Among emotional and physical health measures, only feelings of morale correlated negatively with Step 1 performance. Revised curriculum students' Step 1 scores correlated negatively with stress from difficulty of coursework. Although revised curriculum students reported worse quality of life, general stress, and health and less stress from patient interactions than traditional students, few measures were associated with performance differences on Step 1. Moreover, curriculum type did not appear to either hinder or help students' Step 1 performance. To identify and help students at risk for academic problems, future assessments of correlates of Step 1 performance should be repeated after the new curriculum is well established, relating them also to performance

  16. The prevalence of poor sleep quality and its association with depression and anxiety scores in patients admitted for cardiovascular disease: A cross-sectional designed study.

    Science.gov (United States)

    Matsuda, Risa; Kohno, Takashi; Kohsaka, Shun; Fukuoka, Ryoma; Maekawa, Yuichiro; Sano, Motoaki; Takatsuki, Seiji; Fukuda, Keiichi

    2017-02-01

    Poor sleep quality contributes to the development of various cardiovascular conditions. However, its real-world prevalence among cardiovascular inpatients and association with psychological disturbance is unknown. This study aimed to assess the prevalence of poor sleep quality and its association with depression and anxiety in cardiovascular patients, and explored whether sex and cardiovascular comorbidities modified these associations. A total of 1071 patients hospitalized for a broad spectrum of cardiovascular diseases at a single university hospital were assessed (790 men, mean age 64±14years). We assessed sleep quality during their index hospitalization period using the Pittsburgh Sleep Quality Index (PSQI); poor sleep quality was defined as PSQI>5. Depression and anxiety were assessed with the Hospital Anxiety and Depression Scale (HADS). The median PSQI score was 5.0 [3.0-7.0], and 461 inpatients (43%) had poor sleep quality. Multivariate regression analysis adjusting for patient background, medical risk factors, and laboratory data revealed that poor sleep quality was associated with higher HADS subscores for depression (HADS-depression; odds ratio [OR]: 1.09, 95% confidence interval [CI]: 1.03-1.15) and anxiety (HADS-anxiety; OR: 1.17, 95% CI: 1.11-1.24). Poor sleep quality was associated with markedly higher HADS-depression among women than men (p value for interaction: 0.008). The association between poor sleep quality and HADS-anxiety was more significant among patients without coronary artery diseases (p value for interaction: 0.017). Poor sleep quality was highly prevalent and associated with depression and anxiety in cardiovascular patients. These associations may be modified by sex and the presence of coronary artery diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Low quality of life scores in school children with attention deficit-hyperactivity disorder related to anxiety

    OpenAIRE

    Zambrano-Sánchez,Elizabeth; Martínez-Cortés,José A.; Río-Carlos,Yolanda del; Dehesa-Moreno,Minerva; Poblano,Adrián

    2012-01-01

    OBJECTIVE: Attention deficit hyperactivity disorder (ADHD) is an alteration that begins early in infancy and whose cardinal symptoms are inattention, hyperactivity and impulsivity. There are few studies for specific tests to measure Quality of Life (QoL) in children with ADHD. METHODS: We evaluated QoL of 120 children from 7-12 years of age with ADHD and of a group of 98 healthy control children. To measure QoL, we utilized the Questionnaire of Quality of Life for Children in Pictures (AutoQu...

  18. Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist

    NARCIS (Netherlands)

    Terwee, C.B.; Mokkink, L.B.; Knol, D.L.; Ostelo, R.W.J.G.; Bouter, L.M.; de Vet, H.C.W.

    2012-01-01

    Background: The COSMIN checklist is a standardized tool for assessing the methodological quality of studies on measurement properties. It contains 9 boxes, each dealing with one measurement property, with 5-18 items per box about design aspects and statistical methods. Our aim was to develop a

  19. Parent-Child Book-Reading Styles, Emotional Quality, and Changes in Early Head Start Children's Cognitive Scores

    Science.gov (United States)

    Cline, Keely D.; Edwards, Carolyn Pope

    2017-01-01

    Research Findings: The objective of this study was to understand how instructional book-reading style and emotional quality of reading interact and relate to cognitive skills in a sample of at-risk infants and toddlers. Participants were 81 parents and their children participating in Early Head Start programs in the rural Midwest. Correlation and…

  20. Analysis of High Quality Agar wood Oil Chemical Compounds By Means Of SPME/ GC-MS and Z-Score Technique

    International Nuclear Information System (INIS)

    Nurlaila Ismail; Mohd Ali Nor Azah; Mailina Jamil; Saiful Nizam Tajuddin; Mohd Nasir Taib

    2013-01-01

    Currently, the grading of the agar wood oil to the high and low quality is done using manually such as human trained grader. It was performed based on the agar wood oil physical properties such as human experience and perception and the oil colour, odor and long lasting aroma. Several researchers found that chemical profiles of the oil should be utilized to overcome the problem facing by manual techniques for example human nose cannot tolerate with the many oils at the same time, so that accurate result can be obtained in grading the agar wood oil. The analysis involved of SPME/ GC-MS and Z-score techniques have been proposed in this study to analyze the chemical compounds especially from the high quality samples of agar wood oil (Aquilariamalaccensis) from Malaysia. Two SPME fibers were used such as divinylbenzene-carbogen-polydimethylsiloxane (DVB-CAR-PDMS) and polydimethylsiloxane (PDMS) in extracting the oils compound under three different sampling temperature conditions such as 40, 60 and 80 degree Celsius. The chemical compounds extracted by SPME/ GC-MS were analyzed. The chemical compounds as identified by Z-score as significant compounds were discussed before the conclusion is made. It was found that 10-epi-γ-eudesmol, aromadendrene, β-agar ofuran, α-agar ofuran and γ-eudesmol were highlighted as significant for high quality agar wood oil and can be used as a marker compounds in classifying the agar wood oil. (author)

  1. Greater Independence in Activities of Daily Living is Associated with Higher Health-Related Quality of Life Scores in Nursing Home Residents with Dementia

    Directory of Open Access Journals (Sweden)

    Charice S. Chan

    2015-06-01

    Full Text Available Health-related quality of life (HRQL for nursing home residents is important, however, the concept of quality of life is broad, encompasses many domains and is difficult to assess in people with dementia. Basic activities of daily living (ADL are measured routinely in nursing homes using the Resident Assessment Instrument-Minimum Data Set Version 2.0 (RAI-MDS and Functional Independence Measure (FIM instrument. We examined the relationship between HRQL and ADL to assess the future possibility of ADL dependency level serving as a surrogate measure of HRQL in residents with dementia. To assess ADL, measures derived from the RAI-MDS and FIM data were gathered for 111 residents at the beginning of our study and at 6-month follow-up. Higher scores for independence in ADL were correlated with higher scores for a disease-specific HRQL measure, the Quality of Life—Alzheimer’s Disease Scale. Preliminary evidence suggests that FIM-assessed ADL is associated with HRQL for these residents. The associations of the dressing and toileting items with HRQL were particularly strong. This finding suggests the importance of ADL function in HRQL. The RAI-MDS ADL scales should be used with caution to evaluate HRQL.

  2. Application of Quaternion in improving the quality of global sequence alignment scores for an ambiguous sequence target in Streptococcus pneumoniae DNA

    Science.gov (United States)

    Lestari, D.; Bustamam, A.; Novianti, T.; Ardaneswari, G.

    2017-07-01

    DNA sequence can be defined as a succession of letters, representing the order of nucleotides within DNA, using a permutation of four DNA base codes including adenine (A), guanine (G), cytosine (C), and thymine (T). The precise code of the sequences is determined using DNA sequencing methods and technologies, which have been developed since the 1970s and currently become highly developed, advanced and highly throughput sequencing technologies. So far, DNA sequencing has greatly accelerated biological and medical research and discovery. However, in some cases DNA sequencing could produce any ambiguous and not clear enough sequencing results that make them quite difficult to be determined whether these codes are A, T, G, or C. To solve these problems, in this study we can introduce other representation of DNA codes namely Quaternion Q = (PA, PT, PG, PC), where PA, PT, PG, PC are the probability of A, T, G, C bases that could appear in Q and PA + PT + PG + PC = 1. Furthermore, using Quaternion representations we are able to construct the improved scoring matrix for global sequence alignment processes, by applying a dot product method. Moreover, this scoring matrix produces better and higher quality of the match and mismatch score between two DNA base codes. In implementation, we applied the Needleman-Wunsch global sequence alignment algorithm using Octave, to analyze our target sequence which contains some ambiguous sequence data. The subject sequences are the DNA sequences of Streptococcus pneumoniae families obtained from the Genebank, meanwhile the target DNA sequence are received from our collaborator database. As the results we found the Quaternion representations improve the quality of the sequence alignment score and we can conclude that DNA sequence target has maximum similarity with Streptococcus pneumoniae.

  3. Score distribution of the scoliosis research society health-related quality of life in different subgroups of adolescent subjects unaffected by scoliosis in China.

    Science.gov (United States)

    Wu, Weifei; Du, Yuanli; Liang, Jie; Chen, Ying; Tan, Xiaoyi; Xiang, Xuanping; Wang, Wanhong; Ru, Neng

    2014-02-01

    A comparative study. The aims of this study were to: (1) evaluate Scoliosis Research Society (SRS)-22 questionnaire performance in normal adolescents without scoliosis to establish a normative baseline useful for evaluating the discriminate validity of the SRS-22 in primary adolescent scoliosis; and (2) investigate impact of age and sex on SRS-22 in an adolescent population unaffected by scoliosis. The SRS-22 questionnaire is widely used to measure health-related quality of life of patients with spinal disease including scoliosis and lumbar spondylolisthesis. However, normal data, which are very important, when comparing patients and nonpatients, are few, little, and there are few studies about factors that may affect SRS questionnaire performance. The adolescent population was from 14 schools located in 7 provinces. A total of 2008 adolescents (961 females, 1026 males, 21 unknown; mean age, 14.3 yr; range, 11-20) completed the simplified Chinese version of SRS-22 questionnaire and demographic questions. Surveys were stratified into 8 age-sex groups for analysis: male/female; 12 to 13.4, 13.5 to 14.9, 15 to 15.9, and more than 16 years of age. Post hoc testing and the Tukey least significant difference were used to compare differences between any 2 of the 4 age groups. Self-image scores in males were higher than those in females (P < 0.01). Pain domain scores were significantly higher in males than those in females in the 13.5- to 14.9-year-old subgroup, whereas other subgroups showed no obvious differences. The function domain scores in males who were aged 15 to 15.9 years and those older than 16 years were significantly higher than those in females (P < 0.001). There were no statistically significant differences in mental health domain scores among age-sex subgroups, with the exception of the 13.5- to 14.9-year-old group. This is the first study to characterize the sex and age influence on the SRS-22 scores in normal population. Age and sex have an important

  4. The use of the SF-36 questionnaire in adult survivors of childhood cancer: evaluation of data quality, score reliability, and scaling assumptions

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    Winter David L

    2006-10-01

    Full Text Available Abstract Background The SF-36 has been used in a number of previous studies that have investigated the health status of childhood cancer survivors, but it never has been evaluated regarding data quality, scaling assumptions, and reliability in this population. As health status among childhood cancer survivors is being increasingly investigated, it is important that the measurement instruments are reliable, validated and appropriate for use in this population. The aim of this paper was to determine whether the SF-36 questionnaire is a valid and reliable instrument in assessing self-perceived health status of adult survivors of childhood cancer. Methods We examined the SF-36 to see how it performed with respect to (1 data completeness, (2 distribution of the scale scores, (3 item-internal consistency, (4 item-discriminant validity, (5 internal consistency, and (6 scaling assumptions. For this investigation we used SF-36 data from a population-based study of 10,189 adult survivors of childhood cancer. Results Overall, missing values ranged per item from 0.5 to 2.9 percent. Ceiling effects were found to be highest in the role limitation-physical (76.7% and role limitation-emotional (76.5% scales. All correlations between items and their hypothesised scales exceeded the suggested standard of 0.40 for satisfactory item-consistency. Across all scales, the Cronbach's alpha coefficient of reliability was found to be higher than the suggested value of 0.70. Consistent across all cancer groups, the physical health related scale scores correlated strongly with the Physical Component Summary (PCS scale scores and weakly with the Mental Component Summary (MCS scale scores. Also, the mental health and role limitation-emotional scales correlated strongly with the MCS scale score and weakly with the PCS scale score. Moderate to strong correlations with both summary scores were found for the general health perception, energy/vitality, and social functioning

  5. CONFOLD2: improved contact-driven ab initio protein structure modeling.

    Science.gov (United States)

    Adhikari, Badri; Cheng, Jianlin

    2018-01-25

    Contact-guided protein structure prediction methods are becoming more and more successful because of the latest advances in residue-residue contact prediction. To support contact-driven structure prediction, effective tools that can quickly build tertiary structural models of good quality from predicted contacts need to be developed. We develop an improved contact-driven protein modelling method, CONFOLD2, and study how it may be effectively used for ab initio protein structure prediction with predicted contacts as input. It builds models using various subsets of input contacts to explore the fold space under the guidance of a soft square energy function, and then clusters the models to obtain the top five models. CONFOLD2 obtains an average reconstruction accuracy of 0.57 TM-score for the 150 proteins in the PSICOV contact prediction dataset. When benchmarked on the CASP11 contacts predicted using CONSIP2 and CASP12 contacts predicted using Raptor-X, CONFOLD2 achieves a mean TM-score of 0.41 on both datasets. CONFOLD2 allows to quickly generate top five structural models for a protein sequence when its secondary structures and contacts predictions at hand. The source code of CONFOLD2 is publicly available at https://github.com/multicom-toolbox/CONFOLD2/ .

  6. Development of an indoor air quality checklist for risk assessment of indoor air pollutants by semiquantitative score in nonindustrial workplaces

    Directory of Open Access Journals (Sweden)

    Syazwan AI

    2012-04-01

    Full Text Available AI Syazwan1, B Mohd Rafee1, Juahir Hafizan2, AZF Azman1, AM Nizar3, Z Izwyn4, AA Muhaimin5, MA Syafiq Yunos6, AR Anita1, J Muhamad Hanafiah1, MS Shaharuddin1, A Mohd Ibthisham7, Mohd Hasmadi Ismail8, MN Mohamad Azhar1, HS Azizan1, I Zulfadhli9, J Othman101Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia; 2Department of Environmental Science, Faculty of Environmental Studies, Universiti Putra Malaysia, Selangor, Malaysia; 3Pharmacology Unit, Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia; 4Department of Therapy and Rehabilitation, Faculty of Health Science and Biomedical Engineering, Universiti Teknologi Malaysia, Johor, Malaysia; 5Department of Environmental Management, Faculty of Environmental Studies, Universiti Putra Malaysia, Selangor, Malaysia; 6Plant Assessment Technology (PAT, Industrial Technology Division (BTI, Malaysian Nuclear Agency (Nuklear Malaysia, Bangi, Kajang, Malaysia; 7Department of Mechanical Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, UTM Skudai, Johor, Malaysia; 8Department of Forest Production, Faculty of Forestry, Universiti Putra Malaysia, Selangor, Malaysia; 9Faculty of Built Environment and Architect, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia; 10Department of Counsellor Education and Counselling Psychology (DCECP, Faculty of Educational Studies, Universiti Putra Malaysia, Selangor, MalaysiaBackground: To meet the current diversified health needs in workplaces, especially in nonindustrial workplaces in developing countries, an indoor air quality (IAQ component of a participatory occupational safety and health survey should be included.Objectives: The purpose of this study was to evaluate and suggest a multidisciplinary, integrated IAQ checklist for evaluating the health risk of building occupants. This IAQ checklist proposed to support

  7. Effects of Diquafosol Ophthalmic Solution on Quality of Life in Dry Eye Assessed Using the Dry Eye-Related Quality-of-Life Score Questionnaire: Effectiveness in Patients While Reading and Using Visual Display Terminals.

    Science.gov (United States)

    Utsunomiya, Tsugiaki; Kawahara, Atsushi; Hanada, Kazuomi; Yoshida, Akitoshi

    2017-08-01

    Diquafosol ophthalmic solution improves objective findings in the ocular surface and subjective symptoms in patients with dry eye. The Dry Eye-Related Quality-of-Life Score (DEQS) questionnaire was developed to assess dry eye symptoms and their effects on quality of life. However, because little research using the DEQS has been reported, we evaluated the effects of diquafosol ophthalmic solution on ocular surface findings and quality of life using the DEQS in patients with dry eye. Sixty-three patients with dry eye were assigned to the control group (artificial tears) or diquafosol group. Both groups instilled 1 drop of the solution in both eyes 6 times daily and were evaluated after 2 weeks; the diquafosol group also was instructed to be examined at 1 and 3 months. We evaluated the subjective symptoms using the DEQS, fluorescein staining score, tear film breakup time (BUT), Schirmer testing, and lower tear meniscus height with anterior-segment optical coherence tomography. In the diquafosol group, the fluorescein staining score, BUT, tear meniscus height, and DEQS scores improved significantly compared with before treatment in contrast to the control group. Furthermore, in the diquafosol group, the staining score and BUT improved significantly compared with the control group. Analysis of each DEQS item indicated that diquafosol ophthalmic solution relieved foreign body sensation and problems when reading and using visual display terminals compared with the control group. Diquafosol ophthalmic solution was effective in patients with dry eye, especially those with foreign body sensation and problems when reading and using visual display terminals.

  8. Collective rotation from ab initio theory

    International Nuclear Information System (INIS)

    Caprio, M.A.; Maris, P.; Vary, J.P.; Smith, R.

    2015-01-01

    Through ab initio approaches in nuclear theory, we may now seek to quantitatively understand the wealth of nuclear collective phenomena starting from the underlying internucleon interactions. No-core configuration interaction (NCCI) calculations for p-shell nuclei give rise to rotational bands, as evidenced by rotational patterns for excitation energies, electromagnetic moments and electromagnetic transitions. In this review, NCCI calculations of 7–9 Be are used to illustrate and explore ab initio rotational structure, and the resulting predictions for rotational band properties are compared with experiment. We highlight the robustness of ab initio rotational predictions across different choices for the internucleon interaction. (author)

  9. Among 4 Diet Quality Indexes, Only the Alternate Mediterranean Diet Score Is Associated with Better Colorectal Cancer Survival and Only in African American Women in the Multiethnic Cohort.

    Science.gov (United States)

    Jacobs, Simone; Harmon, Brook E; Ollberding, Nicholas J; Wilkens, Lynne R; Monroe, Kristine R; Kolonel, Laurence N; Le Marchand, Loic; Boushey, Carol J; Maskarinec, Gertraud

    2016-09-01

    Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States, with a 5-y survival rate of ∼65%. Therefore, the identification of modifiable health factors to improve CRC survival is crucial. We investigated the association of 4 prediagnostic a priori diet quality indexes with CRC-specific and all-cause mortality in the Multiethnic Cohort (MEC). The MEC included >215,000 African-American, Native Hawaiian, Japanese-American, Latino, and white adults living in Hawaii and California who completed a validated quantitative food-frequency questionnaire in 1993-1996. CRC cases and deaths were identified through linkages to cancer registries and to state and national vital registries. Sex-specific HRs and 95% CIs were estimated for the Healthy Eating Index (HEI) 2010, the Alternative HEI (AHEI) 2010, the alternate Mediterranean Diet (aMED) score, and the Dietary Approaches to Stop Hypertension (DASH) index with CRC-specific and overall mortality as the primary outcomes. Ethnicity-specific analyses were the secondary outcomes. Among 4204 MEC participants diagnosed with invasive CRC through 2010, 1976 all-cause and 1095 CRC-specific deaths were identified. A higher aMED score was associated with lower CRC-specific mortality in women [HR continuous pattern score divided by its respective SD (HR1SD): 0.86; 95% CI: 0.77, 0.96] but not in men (HR1SD: 1.01; 95% CI: 0.92, 1.11). A higher aMED score was also associated with lower all-cause mortality in women (HR1SD: 0.88; 95% CI: 0.81, 0.96) but not in men (HR1SD: 1.00; 95% CI: 0.93, 1.07). The HEI-2010, AHEI-2010, and DASH index were not significantly associated with CRC-specific or with all-cause mortality. The inverse relation for the aMED score was limited to African Americans and to colon (compared with rectal) cancer. The aMED score was related to lower mortality only in African-American women (1 of 5 ethnic groups studied). The results should be interpreted with caution due to the small

  10. Development and Validation of a Preprocedural Risk Score to Predict Access Site Complications After Peripheral Vascular Interventions Based on the Vascular Quality Initiative Database

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    Daniel Ortiz

    2016-01-01

    Full Text Available Purpose: Access site complications following peripheral vascular intervention (PVI are associated with prolonged hospitalization and increased mortality. Prediction of access site complication risk may optimize PVI care; however, there is no tool designed for this. We aimed to create a clinical scoring tool to stratify patients according to their risk of developing access site complications after PVI. Methods: The Society for Vascular Surgery’s Vascular Quality Initiative database yielded 27,997 patients who had undergone PVI at 131 North American centers. Clinically and statistically significant preprocedural risk factors associated with in-hospital, post-PVI access site complications were included in a multivariate logistic regression model, with access site complications as the outcome variable. A predictive model was developed with a random sample of 19,683 (70% PVI procedures and validated in 8,314 (30%. Results: Access site complications occurred in 939 (3.4% patients. The risk tool predictors are female gender, age > 70 years, white race, bedridden ambulatory status, insulin-treated diabetes mellitus, prior minor amputation, procedural indication of claudication, and nonfemoral arterial access site (model c-statistic = 0.638. Of these predictors, insulin-treated diabetes mellitus and prior minor amputation were protective of access site complications. The discriminatory power of the risk model was confirmed by the validation dataset (c-statistic = 0.6139. Higher risk scores correlated with increased frequency of access site complications: 1.9% for low risk, 3.4% for moderate risk and 5.1% for high risk. Conclusions: The proposed clinical risk score based on eight preprocedural characteristics is a tool to stratify patients at risk for post-PVI access site complications. The risk score may assist physicians in identifying patients at risk for access site complications and selection of patients who may benefit from bleeding avoidance

  11. Family Satisfaction With Nursing Home Care: The Role of Facility Characteristics and Resident Quality-of-Life Scores

    Science.gov (United States)

    Shippee, Tetyana P.; Henning-Smith, Carrie; Gaugler, Joseph E.; Held, Robert; Kane, Robert L.

    2018-01-01

    This article explores the factor structure of a new family satisfaction with nursing home care instrument and determines the relationship of resident quality of life (QOL) and facility characteristics with family satisfaction. Data sources include (1) family satisfaction interviews (n = 16,790 family members), (2) multidimensional survey of resident QOL (n = 13,433 residents), and (3) facility characteristics (n = 376 facilities). We used factor analysis to identify domains of family satisfaction and multivariate analyses to identify the role of facility-level characteristics and resident QOL on facility-mean values of family satisfaction. Four distinct domains were identified for family satisfaction: “care,” “staff,” “environment,” and “food.” Chain affiliation, higher resident acuity, more deficiencies, and large size were all associated with less family satisfaction, and resident QOL was a significant (albeit weak) predictor of family satisfaction. Results suggest that family member satisfaction is distinct from resident QOL but is associated with resident QOL and facility characteristics. PMID:26534835

  12. Orthognathic surgery improves quality of life and depression, but not anxiety, and patients with higher preoperative depression scores improve less.

    Science.gov (United States)

    Brunault, P; Battini, J; Potard, C; Jonas, C; Zagala-Bouquillon, B; Chabut, A; Mercier, J-M; Bedhet, N; Réveillère, C; Goga, D; Courtois, R

    2016-01-01

    This study assessed quality of life (QoL), depression, and anxiety before and after orthognathic surgery and identified risk factors for poorer postoperative outcome. This multicentre prospective study included 140 patients from five French medical centres. We assessed patients before surgery (T1), 3 months after surgery (T2), and 12 months after surgery (T3). We assessed the severity of the orofacial deformity, physical, psychological, social, and environmental QoL (WHOQOL-BREF), and depression and anxiety (GHQ-28). Risk factors for poorer outcome were identified using linear mixed models. Between baseline and 12 months, there was significant improvement in psychological and social QoL and in depression (although below the norms reported in the general population), but not in anxiety. Physical QoL was poorer in patients who were younger, who had a mild orofacial deformity, and who were depressed. Psychological QoL was poorer in younger patients and in depressed patients. Social QoL was poorer in patients who were single, who had a mild orofacial deformity, and who were depressed. Although orthognathic surgery provides a moderate improvement in psychological and social QoL, the systematic screening and treatment of depression could further improve QoL after surgery because it is a major predictor of poor QoL in this population. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  13. Higher Mediterranean Diet Quality Scores and Lower Body Mass Index Are Associated with a Less-Oxidized Plasma Glutathione and Cysteine Redox Status in Adults.

    Science.gov (United States)

    Bettermann, Erika L; Hartman, Terryl J; Easley, Kirk A; Ferranti, Erin P; Jones, Dean P; Quyyumi, Arshed A; Vaccarino, Viola; Ziegler, Thomas R; Alvarez, Jessica A

    2018-02-01

    Both systemic redox status and diet quality are associated with risk outcomes in chronic disease. It is not known, however, the extent to which diet quality influences plasma thiol/disulfide redox status. The purpose of this study was to investigate the influence of diet, as measured by diet quality scores and other dietary factors, on systemic thiol/disulfide redox status. We performed a cross-sectional study of 685 working men and women (ages ≥18 y) in Atlanta, GA. Diet was assessed by 3 diet quality scores: the Alternative Healthy Eating Index (AHEI), Dietary Approaches to Stop Hypertension (DASH), and the Mediterranean Diet Score (MDS). We measured concentrations of plasma glutathione (GSH), cysteine, their associated oxidized forms [glutathione disulfide (GSSG) and cystine (CySS), respectively], and their redox potentials (EhGSSG and EhCySS) to determine thiol/disulfide redox status. Linear regression modeling was performed to assess relations between diet and plasma redox after adjustment for age, body mass index (BMI), sex, race, and history of chronic disease. MDS was positively associated with plasma GSH (β = 0.02; 95% CI: 0.003, 0.03) and total GSH (GSH + GSSG) (β = 0.02; 95% CI: 0.003, 0.03), and inversely associated with the CySS:GSH ratio (β = -0.02; 95% CI: -0.04, -0.004). There were significant independent associations between individual MDS components (dairy, vegetables, fish, and monounsaturated fat intake) and varying plasma redox indexes (P indexes and other diet factors of interest were not significantly correlated with plasma thiol and disulfide redox measures. Adherence to the Mediterranean diet was significantly associated with a favorable plasma thiol/disulfide redox profile, independent of BMI, in a generally healthy working adult population. Although longitudinal studies are warranted, these findings contribute to the feasibility of targeting a Mediterranean diet to improve plasma redox status.

  14. Parent reports of health-related quality of life and heart failure severity score independently predict outcome in children with dilated cardiomyopathy.

    Science.gov (United States)

    den Boer, Susanna L; Baart, Sara J; van der Meulen, Marijke H; van Iperen, Gabriëlle G; Backx, Ad P; Ten Harkel, Arend D; Rammeloo, Lukas A; du Marchie Sarvaas, Gideon J; Tanke, Ronald B; Helbing, Willem A; Utens, Elisabeth M; Dalinghaus, Michiel

    2017-08-01

    Dilated cardiomyopathy in children causes heart failure and has a poor prognosis. Health-related quality of life in this patient group is unknown. Moreover, results may provide detailed information of parents' sense of their child's functioning. We hypothesised that health-related quality of life, as rated by parents, and the paediatric heart failure score, as assessed by physicians, have both predictive value on outcome. Methods and results In this prospective study, health-related quality of life was assessed by parent reports: the Infant Toddler Quality of Life questionnaire (0-4 years) or Child Health Questionnaire-Parent Form 50 (4-18 years) at 3-6-month intervals. We included 90 children (median age 3.8 years, interquartile range (IQR) 0.9-12.3) whose parents completed 515 questionnaires. At the same visit, physicians completed the New York University Pediatric Heart Failure Index. Compared with Dutch normative data, quality of life was severely impaired at diagnosis (0-4 years: 7/10 subscales and 4-18 years: 8/11 subscales) and ⩾1 year after diagnosis (3/10 and 6/11 subscales). Older children were more impaired (pFailure Index were independently predictive of the risk of death and heart transplantation (hazard ratio 1.24 per 10% decrease of predicted, 95% confidence interval (CI) 1.06-1.47 and hazard ratio 1.38 per unit, 95% CI 1.19-1.61, respectively). Physical impairment rated by parents and heart failure severity assessed by physicians independently predicted the risk of death or heart transplantation in children with dilated cardiomyopathy.

  15. Reliability, construct and criterion validity of the KIDSCREEN-10 score: a short measure for children and adolescents’ well-being and health-related quality of life

    Science.gov (United States)

    Erhart, Michael; Rajmil, Luis; Herdman, Michael; Auquier, Pascal; Bruil, Jeanet; Power, Mick; Duer, Wolfgang; Abel, Thomas; Czemy, Ladislav; Mazur, Joanna; Czimbalmos, Agnes; Tountas, Yannis; Hagquist, Curt; Kilroe, Jean

    2010-01-01

    Background To assess the criterion and construct validity of the KIDSCREEN-10 well-being and health-related quality of life (HRQoL) score, a short version of the KIDSCREEN-52 and KIDSCREEN-27 instruments. Methods The child self-report and parent report versions of the KIDSCREEN-10 were tested in a sample of 22,830 European children and adolescents aged 8–18 and their parents (n = 16,237). Correlation with the KIDSCREEN-52 and associations with other generic HRQoL measures, physical and mental health, and socioeconomic status were examined. Score differences by age, gender, and country were investigated. Results Correlations between the 10-item KIDSCREEN score and KIDSCREEN-52 scales ranged from r = 0.24 to 0.72 (r = 0.27–0.72) for the self-report version (proxy-report version). Coefficients below r = 0.5 were observed for the KIDSCREEN-52 dimensions Financial Resources and Being Bullied only. Cronbach alpha was 0.82 (0.78), test–retest reliability was ICC = 0.70 (0.67) for the self- (proxy-)report version. Correlations between other children self-completed HRQoL questionnaires and KIDSCREEN-10 ranged from r = 0.43 to r = 0.63 for the KIDSCREEN children self-report and r = 0.22–0.40 for the KIDSCREEN parent proxy report. Known group differences in HRQoL between physically/mentally healthy and ill children were observed in the KIDSCREEN-10 self and proxy scores. Associations with self-reported psychosomatic complaints were r = −0.52 (−0.36) for the KIDSCREEN-10 self-report (proxy-report). Statistically significant differences in KIDSCREEN-10 self and proxy scores were found by socioeconomic status, age, and gender. Conclusions Our results indicate that the KIDSCREEN-10 provides a valid measure of a general HRQoL factor in children and adolescents, but the instrument does not represent well most of the single dimensions of the original KIDSCREEN-52. Test–retest reliability was slightly below a priori defined thresholds. PMID:20668950

  16. Psychosocial and Quality of Life in Women Receiving the 21-Gene Recurrence Score Assay: The Impact of Decision Style in Women with Intermediate RS

    Directory of Open Access Journals (Sweden)

    Nadiyah Sulayman

    2012-01-01

    Full Text Available Multigene assays such as the 21-gene recurrence score (RS quantify risk for recurrence and potential benefit from chemotherapy in early-stage, ER+ breast cancers. Few studies have assessed the impact of testing on patient-reported outcomes such as cancer-related distress or quality of life. The few studies that have assessed these outcomes do not consider potential modifiers, such as the patients’ level of involvement in the treatment decision-making process. In the current study, 81 breast cancer patients who received the RS assay completed cross-sectional surveys. We used linear multiple regression to assess whether test result, decision-making role (passive versus shared/active, and their interaction contributed to current levels of distress, quality of life, and decisional conflict. There were no associations between these variables and test result or decision-making role. However, women who received an intermediate RS and took a passive role in their care reported higher-cancer-related distress and cancer worry and lower quality of life than those who took a shared or active role. These data should be confirmed in prospective samples, as these poorer outcomes could be amenable to intervention.

  17. Psychosocial and Quality of Life in Women Receiving the 21-Gene Recurrence Score Assay: The Impact of Decision Style in Women with Intermediate RS

    International Nuclear Information System (INIS)

    Sulayman, N.; Spellman, E.; Graves, K. D.; Peshkin, B. N.; Isaacs, C.; Schwartz, M. D.; O’Neill, S. C.

    2012-01-01

    Multigene assays such as the 21-gene recurrence score (RS) quantify risk for recurrence and potential benefit from chemotherapy in early-stage, ER+ breast cancers. Few studies have assessed the impact of testing on patient-reported outcomes such as cancer-related distress or quality of life. The few studies that have assessed these outcomes do not consider potential modifiers, such as the patients’ level of involvement in the treatment decision-making process. In the current study, 81 breast cancer patients who received the RS assay completed cross-sectional surveys. We used linear multiple regression to assess whether test result, decision-making role (passive versus shared/active), and their interaction contributed to current levels of distress, quality of life, and decisional conflict. There were no associations between these variables and test result or decision-making role. However, women who received an intermediate RS and took a passive role in their care reported higher-cancer-related distress and cancer worry and lower quality of life than those who took a shared or active role. These data should be confirmed in prospective samples, as these poorer outcomes could be amenable to intervention

  18. Proposal for evaluating the quality of reports of surgical interventions in the treatment of trigeminal neuralgia: the Surgical Trigeminal Neuralgia Score.

    Science.gov (United States)

    Akram, Harith; Mirza, Bilal; Kitchen, Neil; Zakrzewska, Joanna M

    2013-09-01

    The aim of this study was to design a checklist with a scoring system for reporting on studies of surgical interventions for trigeminal neuralgia (TN) and to validate it by a review of the recent literature. A checklist with a scoring system, the Surgical Trigeminal Neuralgia Score (STNS), was devised partially based on the validated STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) criteria and customized for TN after a literature review and then applied to a series of articles. These articles were identified using a prespecified MEDLINE and Embase search covering the period from 2008 to 2010. Of the 584 articles found, 59 were studies of interventional procedures for TN that fulfilled the inclusion criteria and 56 could be obtained in full. The STNS was then applied independently by 3 of the authors. The maximum STNS came to 30, and was reliable and reproducible when used by the 3 authors who performed the scoring. The range of scores was 6-23.5, with a mean of 14 for all the journals. The impact factor scores of the journals in which the papers were published ranged from 0 to 4.8. Twenty-four of the studies were published in the Journal of Neurosurgery or in Neurosurgery. Studies published in neurosurgical journals ranked higher on the STNS scale than those published in nonneurosurgical journals. There was no statistically significant correlation between STNS and impact factors. Stereotactic radiosurgery (n = 25) and microvascular decompression (n = 15) were the most commonly reported procedures. The diagnostic criteria were stated in 35% of the studies, and 4 studies reported subtypes of TN. An increasing number of studies (46%) used the recommended Kaplan-Meier methodology for pain survival outcomes. The follow-up period was unclear in 8 studies, and 26 reported follow-ups of more than 5 years. Complications were reported fairly consistently but the temporal course was not always indicated. Direct interview, telephone conversation

  19. An audit of the impact of a consultation with a paediatric dermatology team on quality of life in infants with atopic eczema and their families: further validation of the Infants' Dermatitis Quality of Life Index and Dermatitis Family Impact score.

    Science.gov (United States)

    Beattie, P E; Lewis-Jones, M S

    2006-12-01

    Atopic dermatitis (AD) accounts for 10-20% of referrals to secondary care dermatology, often requiring multiple visits and occupying much valuable time and resources. We audited the usefulness (ease of use, reliability and sensitivity to change) of two simple and easy to use quality of life (QoL) measures, the Infants' Dermatitis Quality of Life Index (IDQOL) and Dermatitis Family Impact (DFI), for assessing the impact on QoL of AD in infants and their families in a routine clinical setting. We also examined the impact of an initial consultation with a dermatology team on AD severity and QoL impairment from the parent's perspective. The parents of 203 infants (mean age 19.8 months) with AD attending paediatric dermatology clinics completed the DFI and IDQOL. The parents of 50 of these infants completed both questionnaires before first and second consultations. In the 203 children the mean of both the IDQOL and DFI scores was 8.47 (median 8 and 7 and SD 5.8 and 6.5, respectively). The IDQOL and DFI correlated well (r(s) = 0.776, P emotional distress. In both measures these domains also correlated most strongly with eczema severity. After dermatology consultation the median global severity score, rated by 50 parents, fell from 2 (SD 0.83) to 1 (SD 0.8; 95% confidence interval, CI 0.5-1), the median IDQOL score fell from 8 (SD 5.92) to 5.5 (SD 5.92; 95% CI 2-5.5) and the median DFI score fell from 9 (SD 6.45) to 3 (SD 6.56; 95% CI 2-5.5). In 50 infants the median IDQOL scores for those infants with global AD severity scores of 1, 2 and 3 were 5 (SD 5.65), 8 (SD 4.27) and 14 (SD 5.67), respectively and improved by 10%, 38% and 64%, respectively while the median DFI scores improved by 54%, 56% and 79%, respectively. The most improved IDQOL items were the time taken to get to sleep and difficulty at mealtimes and the most improved DFI domains were tiredness/exhaustion and emotional distress in the parents. We have provided further important information on the effects of

  20. Structural Equation Modelling with Three Schemes Estimation of Score Factors on Partial Least Square (Case Study: The Quality Of Education Level SMA/MA in Sumenep Regency)

    Science.gov (United States)

    Anekawati, Anik; Widjanarko Otok, Bambang; Purhadi; Sutikno

    2017-06-01

    Research in education often involves a latent variable. Statistical analysis technique that has the ability to analyze the pattern of relationship among latent variables as well as between latent variables and their indicators is Structural Equation Modeling (SEM). SEM partial least square (PLS) was developed as an alternative if these conditions are met: the theory that underlying the design of the model is weak, does not assume a certain scale measurement, the sample size should not be large and the data does not have the multivariate normal distribution. The purpose of this paper is to compare the results of modeling of the educational quality in high school level (SMA/MA) in Sumenep Regency with structural equation modeling approach partial least square with three schemes estimation of score factors. This paper is a result of explanatory research using secondary data from Sumenep Education Department and Badan Pusat Statistik (BPS) Sumenep which was data of Sumenep in the Figures and the District of Sumenep in the Figures for the year 2015. The unit of observation in this study were districts in Sumenep that consists of 18 districts on the mainland and 9 districts in the islands. There were two endogenous variables and one exogenous variable. Endogenous variables are the quality of education level of SMA/MA (Y1) and school infrastructure (Y2), whereas exogenous variable is socio-economic condition (X1). In this study, There is one improved model which represented by model from path scheme because this model is a consistent, all of its indicators are valid and its the value of R-square increased which is: Y1=0.651Y2. In this model, the quality of education influenced only by the school infrastructure (0.651). The socio-economic condition did not affect neither the school infrastructure nor the quality of education. If the school infrastructure increased 1 point, then the quality of education increased 0.651 point. The quality of education had an R2 of 0

  1. Relationship between body mass index, fat mass and lean mass with SF-36 quality of life scores in a group of fibromyalgia patients.

    Science.gov (United States)

    Arranz, Laura; Canela, Miguel Angel; Rafecas, Magda

    2012-11-01

    Patients suffering from fibromyalgia (FM) had widespread musculoskeletal pain and stiffness, fatigue, sleep disorders, cognitive impairment and other symptoms, which seriously affects their quality of life (QoL), making it difficult to perform normal activities. Moreover, FM has been associated with a higher prevalence of overweight and obesity than in the general population. Weight reduction has been beneficial in both FM and other rheumatic patients. Obesity and overweight have been pointed as playing a relevant role in FM symptoms; however, it is necessary to find out more about this relationship. The objective of this study was to evaluate the relationship between body mass index (BMI), fat mass (fM) and lean mass (lM) with quality of life in a group of FM patients. 103 women, with a mean age of 53.74 ± 7.81, and members of different FM patient associations from Spain participated in our study. Some anthropometric measures were taken like weight, height, BMI, body fat mass and lean mass. FM patients QoL was assessed by the Short-Form Health Survey, SF-36 questionnaire. Statistical reports were based on mean, standard deviation and correlation, but significance was tested by nonparametric methods. BMI, fM and lM correlated differently with the specific SF-36 scores. BMI had a high negative correlation with emotional role, fM with bodily pain and lM almost with all scores but specially with emotional role, vitality and physical role. The outcome of this study reveals some interesting relationships, which need to be further investigated to improve the management of FM patients.

  2. Elastogram quality assessment score in vibration-controlled transient elastography: Diagnostic performance compared to digital morphometric analysis of liver biopsy in chronic hepatitis C.

    Science.gov (United States)

    Mendes, L C; Ferreira, P A; Miotto, N; Zanaga, L; Gonçales, E S L; Pedro, M N; Lazarini, M S; Júnior, F L G; Stucchi, R S B; Vigani, A G

    2018-04-01

    Vibration-controlled transient elastography (VCTE) is widely used for noninvasive fibrosis staging in chronic hepatitis C. However, internal validation is based solely on variability and success rate and lacks reproducible quality indicators. We analysed the graphic representation of shear wave propagation in comparison with morphometric results of liver biopsy, eliminating observer variability bias. Individual elastograms were classified according to two morphologic criteria: extension of wave propagation (length of the graphic representation) and shear wave dispersal (level of parallelism displayed in the elastogram). Then, a score based on these criteria stratified the elastogram in classes I through III (highest to lowest technical quality). Liver stiffness results of each measurement were compared with collagen contents in liver biopsy by morphometric analysis. A total of 3243 elastograms were studied (316 patients). Digital morphometry in liver biopsy showed significant fibrosis in 66% of samples and advanced fibrosis in 31%. Elastogram quality analysis resulted in 1438 class I measurements (44%), 1070 class II (34%) and 735 class III. Area under the receiver operating curve (AUROC) for severe fibrosis according to class (I, II and III) was 0.941, 0.887 and 0.766, respectively. For advanced fibrosis, AUROCs were 0.977, 0.883 and 0.781, respectively. Spearman's correlation testing for all classes and levels of fibrosis demonstrated significant independent association (r 2  = -.95, P digital morphometric imaging analysis. We concluded that VCTE performance is significantly influenced by quality assessment of individual measurements. Considering these criteria in clinical practice may improve accuracy. © 2017 John Wiley & Sons Ltd.

  3. Examination of the Five Comparable Component Scores of the Diet Quality Indexes HEI-2005 and RC-DQI Using a Nationally Representative Sample of 2–18 Year Old Children: NHANES 2003–2006

    Directory of Open Access Journals (Sweden)

    Sibylle Kranz

    2013-01-01

    Full Text Available Obesity has been associated with low diet quality and the suboptimal intake of food groups and nutrients. Two composite diet quality measurement tools are appropriate for Americans 2–18 years old: the Healthy Eating Index (HEI 2005 and the Revised Children’s Diet Quality Index (RC-DQI. The five components included in both indexes are fruits, vegetables, total grains, whole grains, and milk/dairy. Component scores ranged from 0 to 5 or 0 to 10 points with lower scores indicating suboptimal intake. To allow direct comparisons, one component was rescaled by dividing it by 2; then, all components ranged from 0 to 5 points. The aim of this study was to directly compare the scoring results of these five components using dietary data from a nationally representative sample of children (NHANES 2003–2006, . Correlation coefficients within and between indexes showed less internal consistency in the HEI; age- and ethnic-group stratified analyses indicated higher sensitivity of the RC-DQI. HEI scoring was likely to dichotomize the population into two groups (those with 0 and those with 5 points, while RC-DQI scores resulted in a larger distribution of scores. The scoring scheme of diet quality indexes for children results in great variation of the outcomes, and researchers must be aware of those effects.

  4. On-farm animal welfare assessment in beef bulls: consistency over time of single measures and aggregated Welfare Quality(®) scores.

    Science.gov (United States)

    Kirchner, M K; Schulze Westerath, H; Knierim, U; Tessitore, E; Cozzi, G; Winckler, C

    2014-03-01

    Consistency over time of (on-farm) animal welfare assessment systems forms part of reliability, meaning that results of the assessment should be representative of the longer-term welfare state of the farm as long as the housing and management conditions have not changed considerably. This is especially important if assessments are to be used for certification purposes. It was the aim of the present study to investigate consistency over time of the Welfare Quality(®) (WQ(®)) assessment system for fattening cattle at single measure level, aggregated criterion and principle scores, and overall classification across short-term (1 month) and longer-term periods (6 months). We hypothesized that consistency over time of aggregated criterion and principle scores is higher than that of single measures. Consistency was also expected to be lower with longer intervals between assessments. Data were obtained using the WQ(®) protocol for fattening cattle during three visits (months 0, 1 and 7) on 63 beef farms in Austria, Germany and Italy. Only data from farms where no major changes in housing and management had taken place were considered for analysis. At the single measure level, Spearman rank correlations between visits were >0.7 and variance was lower within farms than between farms for six and two of 19 measures after 1 month and 6 months, respectively. After aggregation of single measures into criterion and principle scores, five and two of 10 criteria and three and one of four principles were found reliable after 1 and 6 months, respectively. At the WQ(®) principle level, this was the case for three and one of four principles. Seventy-nine per cent and 75% of the farms were allocated to the same overall welfare category after 1 month and 6 months. Possible reasons for a lack of consistency are seasonal effects or short-term fluctuations that occur under normal farm conditions, low prevalence of clinical measures and probably insufficient sample size, whereas poor

  5. Global tilt and lumbar lordosis index: two parameters correlating with health-related quality of life scores-but how do they truly impact disability?

    Science.gov (United States)

    Boissière, Louis; Takemoto, Mitsuru; Bourghli, Anouar; Vital, Jean-Marc; Pellisé, Ferran; Alanay, Ahmet; Yilgor, Caglar; Acaroglu, Emre; Perez-Grueso, Francisco Javier; Kleinstück, Frank; Obeid, Ibrahim

    2017-04-01

    Many radiological parameters have been reported to correlate with patient's disability including sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence minus lumbar lordosis (PI-LL). European literature reports other parameters such as lumbar lordosis index (LLI) and the global tilt (GT). If most parameters correlate with health-related quality of life scores (HRQLs), their impact on disability remains unclear. This study aimed to validate these parameters by investigating their correlation with HRQLs. It also aimed to evaluate the relationship between each of these sagittal parameters and HRQLs to fully understand the impact in adult spinal deformity management. A retrospective review of a multicenter, prospective database was carried out. The database inclusion criteria were adults (>18 years old) presenting any of the following radiographic parameters: scoliosis (Cobb ≥20°), SVA ≥5 cm, thoracic kyphosis ≥60° or PT ≥25°. All patients with complete data at baseline were included. Health-related quality of life scores, demographic variables (DVs), and radiographic parameters were collected at baseline. Differences in HRQLs among groups of each DV were assessed with analyses of variance. Correlations between radiographic variables and HRQLs were assessed using the Spearman rank correlation. Multivariate linear regression models were fitted for each of the HRQLs (Oswestry Disability Index [ODI], Scoliosis Research Society-22 subtotal score, or physical component summaries) with sagittal parameters and covariants as independent variables. A p<.05 value was considered statistically significant. Among a total of 755 included patients (mean age, 52.1 years), 431 were non-surgical candidates and 324 were surgical candidates. Global tilt and LLI significantly correlated with HRQLs (r=0.4 and -0.3, respectively) for univariate analysis. Demographic variables such as age, gender, body mass index, past surgery, and surgical or non-surgical candidate

  6. Validation of the Brazilian Portuguese version of the Premenstrual Symptoms Screening Tool (PSST) and association of PSST scores with health-related quality of life.

    Science.gov (United States)

    Câmara, Rachel de A; Köhler, Cristiano A; Frey, Benicio N; Hyphantis, Thomas N; Carvalho, André F

    2017-01-01

    To develop and validate a Brazilian Portuguese version of the Premenstrual Symptoms Screening Tool (PSST), a questionnaire used for the screening of premenstrual syndrome (PMS) and of the most severe form of PMS, premenstrual dysphoric disorder (PMDD). The PSST also rates the impact of premenstrual symptoms on daily activities. A consecutive sample of 801 women aged ≥ 18 years completed the study protocol. The internal consistency, test-retest reliability, and content validity of the Brazilian PSST were determined. The independent association of a positive screen for PMS or PMDD and quality of life determined by the World Health Organization Quality of Life instrument-Abbreviated version (WHOQOL-Bref) was also assessed. Of 801 participants, 132 (16.5%) had a positive screening for PMDD. The Brazilian PSST had adequate internal consistency (Cronbach's alpha = 0.91) and test-retest reliability. The PSST also had adequate convergent/discriminant validity, without redundancy. Content validity ratio and content validity index were 0.61 and 0.94 respectively. Finally, a positive screen for PMS/PMDD was associated with worse WHOQOL-Bref scores. These findings suggest that PSST is a reliable and valid instrument to screen for PMS/PMDD in Brazilian women.

  7. A Probabilistic Decision-Making Scoring System for Quality and Safety Management in Aloreña de Málaga Table Olive Processing

    Directory of Open Access Journals (Sweden)

    Miguel Á. Ruiz Bellido

    2017-11-01

    Full Text Available Table olives are one of the most representatives and consumed fermented vegetables in Mediterranean countries. However, there is an evident lack of standardization of production processes and HACCP systems thus implying the need of establishing decision-making tools allowing their commercialization and shelf-life extension. The present work aims at developing a decision-making scoring system by means of a probabilistic assessment to standardize production process of Aloreña de Málaga table olives based on the identification of potential hazards or deficiencies in hygienic processes for the subsequent implementation of corrective measures. A total of 658 microbiological and physico-chemical data were collected over three consecutive olive campaigns (2014–2016 to measure the variability and relative importance of each elaboration step on total hygienic quality and product safety. Three representative companies were visited to collect samples from food-contact surfaces, olive fruits, brines, air environment, olive dressings, water tanks, and finished/packaged products. A probabilistic assessment was done based on the establishment of Performance Hygiene and Safety Scores (PHSS 0–100% through a standardized system for evaluating product acceptability. The mean value of the global PHSS for the Aloreña de Málaga table olives processing (PHHSFTOT was 64.82% (90th CI: 52.78–76.39% indicating the high variability among facilities in the evaluated processing steps on final product quality and safety. Washing and cracking, and selection and addition of olive dressings were detected as the most deficient ones in relation to PHSSFi values (p < 0.05 (mean = 53.02 and 56.62%, respectively. The relative contribution of each processing step was quantified by different experts (n = 25 from the Aloreña de Málaga table olive sector through a weighted PHSS (PHSSw. The mean value of PHSSw was 65.53% (90th CI: 53.12–77.52%. The final processing steps

  8. Associations between preoperative Oxford hip and knee scores and costs and quality of life of patients undergoing primary total joint replacement in the NHS England: an observational study.

    Science.gov (United States)

    Eibich, Peter; Dakin, Helen A; Price, Andrew James; Beard, David; Arden, Nigel K; Gray, Alastair M

    2018-04-10

    To assess how costs and quality of life (measured by EuroQoL-5 Dimensions (EQ-5D)) before and after total hip replacement (THR) and total knee replacement (TKR) vary with age, gender and preoperative Oxford hip score (OHS) and Oxford knee score (OKS). Regression analyses using prospectively collected data from clinical trials, cohort studies and administrative data bases. UK secondary care. Men and women undergoing primary THR or TKR. The Hospital Episode Statistics data linked to patient-reported outcome measures included 602 176 patients undergoing hip or knee replacement who were followed up for up to 6 years. The Knee Arthroplasty Trial included 2217 patients undergoing TKR who were followed up for 12 years. The Clinical Outcomes in Arthroplasty Study cohort included 806 patients undergoing THR and 484 patients undergoing TKR who were observed for 1 year. EQ-5D-3L quality of life before and after surgery, costs of primary arthroplasty, costs of revision arthroplasty and the costs of hospital readmissions and ambulatory costs in the year before and up to 12 years after joint replacement. Average postoperative utility for patients at the 5th percentile of the OHS/OKS distribution was 0.61/0.5 for THR/TKR and 0.89/0.85 for patients at the 95th percentile. The difference between postoperative and preoperative EQ-5D utility was highest for patients with preoperative OHS/OKS lower than 10. However, postoperative EQ-5D utility was higher than preoperative utility for all patients with OHS≤46 and those with OKS≤44. In contrast, costs were generally higher for patients with low preoperative OHS/OKS than those with high OHS/OKS. For example, costs of hospital readmissions within 12 months after primary THR/TKR were £740/£888 for patients at the 5th percentile compared with £314/£404 at the 95th percentile of the OHS/OKS distribution. Our findings suggest that costs and quality of life associated with total joint replacement vary systematically with

  9. Ab initio model of porous periclase

    International Nuclear Information System (INIS)

    Drummond, Neil D.; Swift, Damian C.; Ackland, Graeme J.

    2004-01-01

    A two-phase equilibrium equation of state (EOS) for periclase (MgO) was constructed using ab initio quantum mechanics, including a rigorous calculation of quasiharmonic phonon modes. Much of the shock wave data reported for periclase is on porous material. We compared the theoretical EOS with porous data using a simple 'snowplough' treatment and also a model using finite equilibration rates suitable for continuum mechanics simulations. (This model has been applied previously to various heterogeneous explosives as well as other porous materials.) The results were consistent and matched the data well at pressures above the regime affected by strength - and ramp-wave formation - during compaction. Ab initio predictions of the response of porous material have been cited recently as a novel and advanced capability; we feel that this is a fairly routine extension to established ab initio techniques

  10. Health utility scores from EQ-5D and health-related quality of life in patients with esophageal cancer: a real-world cross-sectional study.

    Science.gov (United States)

    Doherty, M K; Leung, Y; Su, J; Naik, H; Patel, D; Eng, L; Kong, Q Q; Mohsin, F; Brown, M C; Espin-Garcia, O; Vennettilli, A; Renouf, D J; Faluyi, O O; Knox, J J; MacKay, H; Wong, R; Howell, D; Mittmann, N; Darling, G E; Cella, D; Xu, W; Liu, G

    2018-06-14

    Esophageal cancer and its treatment can cause serious morbidity/toxicity. These effects on health-related quality of life (HRQOL) can be measured using disease-specific scales such as FACT-E, generic scales such as EQ-5D-3L, or through symptoms. In a two-year cross-sectional study, we compared HRQOL across esophageal cancer patients treated in an ambulatory clinic and across multiple disease states, among patients with all stages of esophageal cancer. Consenting patients completed FACT-E, EQ-5D, a visual analog scale, and patient reported (PR)-ECOG. Symptom complexes were constructed from FACT-E domains. Responses were categorized by disease state: pre-, during, and post-treatment, surveillance, progression, and palliative chemotherapy. Spearman correlation and multivariable linear regression characterized these associations. In total, 199 patients completed 317 questionnaires. Mean FACT-E and subscale scores dropped from baseline through treatment and recovered during post-treatment surveillance (P < 0.001); EQ-5D health utility scores (HUS) displayed a similar pattern but with smaller differences (P = 0.07), and with evidence of ceiling effect. Among patients with stage II/III esophageal cancer, mean EQ-5D HUS varied across disease states (P < 0.001), along with FACT-E and subscales (P < 0.001). Among patients with advanced disease, there was no significant difference between baseline and on-treatment total scores, but improved esophageal cancer-specific scales were noted (P = 0.003). Strong correlation was observed between EQ-5D and FACT-E (R = 0.73), along with physical and functional subscales. In addition, the association between FACT-E and EQ-5D HUS was maintained in a multivariable model (P < 0.001). We interpret these results to suggest that in a real-world clinic setting, FACT-E, EQ-5D HUS, and symptoms were strongly correlated. Most HRQOL and symptom parameters suggested that patients had worse HRQOL and symptoms during curative therapy

  11. Ab initio valence calculations in chemistry

    CERN Document Server

    Cook, D B

    1974-01-01

    Ab Initio Valence Calculations in Chemistry describes the theory and practice of ab initio valence calculations in chemistry and applies the ideas to a specific example, linear BeH2. Topics covered include the Schrödinger equation and the orbital approximation to atomic orbitals; molecular orbital and valence bond methods; practical molecular wave functions; and molecular integrals. Open shell systems, molecular symmetry, and localized descriptions of electronic structure are also discussed. This book is comprised of 13 chapters and begins by introducing the reader to the use of the Schrödinge

  12. Reporting health-related quality of life scores to physicians during routine follow-up visits of pediatric oncology patients: is it effective?

    Science.gov (United States)

    Engelen, Vivian; Detmar, Symone; Koopman, Hendrik; Maurice-Stam, Heleen; Caron, Huib; Hoogerbrugge, Peter; Egeler, R Maarten; Kaspers, Gertjan; Grootenhuis, Martha

    2012-05-01

    The aim of the current study is to investigate the effectiveness of an intervention that provides health-related quality of life (HRQOL) scores of the patient (the QLIC-ON PROfile) to the pediatric oncologist. Children with cancer participated in a sequential cohort intervention study: intervention N = 94, control N = 99. Primary outcomes of effectiveness were communication about HRQOL domains (t-test, Mann-Whitney U-test) and identification of HRQOL problems (chi-squared test). Secondary outcomes were satisfaction (multilevel analysis), referrals (chi-squared test), and HRQOL (multilevel analysis). The QLIC-ON PROfile increased discussion of emotional functioning (control M = 32.9 vs. intervention M = 47.4, P vs. M = 63.8, P vs. intervention 3%, P fear (14% vs. 0%, P sadness (26% vs. 0%, P < 0.001). The intervention had no effect on satisfaction and referrals, but did improve HRQOL of patients 5-7 years of age with respect to self-esteem (P < 0.05), family activities (P < 0.05), and psychosocial functioning (P < 0.01). We conclude that a PRO is a helpful tool for systematic monitoring HRQOL of children with cancer, without lengthening the duration of the consultation. It is recommended to be implemented in clinical practice. Copyright © 2011 Wiley Periodicals, Inc.

  13. Ab Initio molecular dynamics with excited electrons

    NARCIS (Netherlands)

    Alavi, A.; Kohanoff, J.; Parrinello, M.; Frenkel, D.

    1994-01-01

    A method to do ab initio molecular dynamics suitable for metallic and electronically hot systems is described. It is based on a density functional which is costationary with the finite-temperature functional of Mermin, with state being included with possibly fractional occupation numbers.

  14. An ab initio and TD DFT

    Indian Academy of Sciences (India)

    The photophysical behaviour of N-(2-hydroxy benzylidene) aniline or most commonly known as salicylideneaniline (SA) has been investigated using the ab initio and DFT levels of theory. The quantum chemical calculations show that the optimized non planar enol (1) form of the SA molecule is the most stable conformer ...

  15. The natural progression of health-related quality of life: results of a five-year prospective study of SF-36 scores in a normative population.

    Science.gov (United States)

    Hopman, Wilma M; Berger, Claudie; Joseph, Lawrence; Towheed, Tanveer; VandenKerkhof, Elizabeth; Anastassiades, Tassos; Adachi, Jonathan D; Ioannidis, George; Brown, Jacques P; Hanley, David A; Papadimitropoulos, Emmanuel A

    2006-04-01

    Limited information exists regarding the natural progression of health-related quality of life (HRQOL) in the general population, as most research has been cross-sectional or has followed populations with specific medical conditions. Such norms are important to establish, because the effect of any intervention may be confounded by changes due to the natural progression of HRQOL over time. Participants were randomly selected from 9 Canadian cities and surrounding rural areas. Changes in the eight domains and 2 summary component scores of the Medical Outcomes Study 36-item short form (SF-36) were examined over a 5 year period (1996/1997-2001/2002). Mean changes were calculated for men and women within 10 year age categories. Multiple imputation was used to adjust for potential selection bias due to missing data. The baseline sample included 6539 women and 2884 men. Loss to follow-up was 17% for women and 23% for men. Mean changes tended to be small, but there was an overall trend towards decreasing HRQOL over time. Changes were more pronounced in the older age groups and in the physically oriented domains. Younger age groups tended towards small mean improvements, particularly in the mentally oriented domains. Large standard errors suggest that on an individual level, large improvements in some participants are balanced by large declines in others. In general, the HRQOL of Canadians appears relatively stable over a 5 year period. However, care should be taken when assessing HRQOL longitudinally in certain age or gender groups, as changes associated with an intervention can potentially be confounded by the natural progression of HRQOL.

  16. Trends in Classroom Observation Scores

    Science.gov (United States)

    Casabianca, Jodi M.; Lockwood, J. R.; McCaffrey, Daniel F.

    2015-01-01

    Observations and ratings of classroom teaching and interactions collected over time are susceptible to trends in both the quality of instruction and rater behavior. These trends have potential implications for inferences about teaching and for study design. We use scores on the Classroom Assessment Scoring System-Secondary (CLASS-S) protocol from…

  17. Towards hydrogen metallization: an Ab initio approach

    International Nuclear Information System (INIS)

    Bernard, St.

    1998-01-01

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H 2 ) 2 which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author)

  18. Highly scalable Ab initio genomic motif identification

    KAUST Repository

    Marchand, Benoit; Bajic, Vladimir B.; Kaushik, Dinesh

    2011-01-01

    We present results of scaling an ab initio motif family identification system, Dragon Motif Finder (DMF), to 65,536 processor cores of IBM Blue Gene/P. DMF seeks groups of mutually similar polynucleotide patterns within a set of genomic sequences and builds various motif families from them. Such information is of relevance to many problems in life sciences. Prior attempts to scale such ab initio motif-finding algorithms achieved limited success. We solve the scalability issues using a combination of mixed-mode MPI-OpenMP parallel programming, master-slave work assignment, multi-level workload distribution, multi-level MPI collectives, and serial optimizations. While the scalability of our algorithm was excellent (94% parallel efficiency on 65,536 cores relative to 256 cores on a modest-size problem), the final speedup with respect to the original serial code exceeded 250,000 when serial optimizations are included. This enabled us to carry out many large-scale ab initio motiffinding simulations in a few hours while the original serial code would have needed decades of execution time. Copyright 2011 ACM.

  19. [Prognostic scores for pulmonary embolism].

    Science.gov (United States)

    Junod, Alain

    2016-03-23

    Nine prognostic scores for pulmonary embolism (PE), based on retrospective and prospective studies, published between 2000 and 2014, have been analyzed and compared. Most of them aim at identifying PE cases with a low risk to validate their ambulatory care. Important differences in the considered outcomes: global mortality, PE-specific mortality, other complications, sizes of low risk groups, exist between these scores. The most popular score appears to be the PESI and its simplified version. Few good quality studies have tested the applicability of these scores to PE outpatient care, although this approach tends to already generalize in the medical practice.

  20. Measuring health-related quality of life in population-based studies of coronary heart disease: comparing six generic indexes and a disease-specific proxy score.

    Science.gov (United States)

    Garster, Noelle C; Palta, Mari; Sweitzer, Nancy K; Kaplan, Robert M; Fryback, Dennis G

    2009-11-01

    To compare HRQoL differences with CHD in generic indexes and a proxy CVD-specific score in a nationally representative sample of U.S. adults. The National Health Measurement Study, a cross-sectional random-digit-dialed telephone survey of adults aged 35-89, administered the EQ-5D, QWB-SA, HUI2, HUI3, SF-36v2 (yielding PCS, MCS, and SF-6D), and HALex. Analyses compared 3,350 without CHD (group 1), 265 with CHD not taking chest pain medication (group 2), and 218 with CHD currently taking chest pain medication (group 3), with and without adjustment for demographic variables and comorbidities. Data on 154 patients from heart failure clinics were used to construct a proxy score utilizing generic items probing CVD symptoms. Mean scores differed between CHD groups for all indexes with and without adjustment (P < 0.0001 for all except MCS P = 0.018). Unadjusted group 3 versus 1 differences were about three times larger than for group 2 versus 1. Standardized differences for the proxy score were similar to those for generic indexes, and were about 1.0 for all except MCS for group 3 versus 1. Generic indexes capture differences in HRQoL in population-based studies of CHD similarly to a score constructed from questions probing CVD-specific symptoms.

  1. Designing a Score-Based Method for the Evaluation of the Nutritional Quality of the Gluten-Free Bakery Products and their Gluten-Containing Counterparts

    NARCIS (Netherlands)

    Morreale, Federico; Angelino, Donato; Pellegrini, Nicoletta

    2018-01-01

    Gluten-free (GF) products are consumed both by individuals with celiac disease and by an increasing number of people with no specific medical needs. Although the technological quality of GF products has been recently improved, their nutritional quality is still scarcely addressed. Moreover, the few

  2. Higher-Order Factor Analysis as a Score Validity Evaluation Tool: An Example with a Measure of Perceptions of Library Service Quality.

    Science.gov (United States)

    Cook, Colleen; Thompson, Bruce

    The SERVQUAL measure was developed by A. Parasuraman, L. Berry, and V. Zeithaml (1988) to measure perceptions of service quality, originally in the retailing sector. However, libraries and other educational institutions are also service providers. Librarians in particular have increasingly become interested in measuring quality of service as the…

  3. Comparing the use and interpretation of PGMI scoring to assess the technical quality of screening mammograms in the UK and Norway

    International Nuclear Information System (INIS)

    Boyce, M.; Gullien, R.; Parashar, D.; Taylor, K.

    2015-01-01

    Objectives: To compare PGMI systems used in the UK and Norway, determine levels of agreement in its interpretation for radiographers within and between centres, informing further research towards developing a more quantitative, uniform system. Methods: Mammograms from 112 women consecutively screened in the UK and Norway were anonymised, numbered and enriched to include all four PGMI categories. Cases were scored by five mammographers from each centre using local PGMI. Sets were exchanged and the process repeated. Distribution of categories was recorded and faults documented for images scored less than perfect. These were compared within and between centres and agreement analysed using non-weighted kappa statistic. Results: Norway uses 38 assessment criteria, the UK uses 15. Best agreement was between Norway raters scoring MLO views from both UK(RMLO k = 0.57, LMLO k = 0.490) and Norway (RMLO k = 0.48, LMLO k = 0.470). Least agreement was between UK raters scoring CC views from both UK(RCC k = 0.007, LCC k = 0.01) and Norway(RCC k = −0.04, LCC k = −0.003). There were no other apparent trends in inter-rater assessment. Most frequent faults in both test sets were on MLO views. Two out of three most common faults were the same for UK and Norway raters. Conclusions: Use of PGMI varied between centres in both number and interpretation of criteria employed. We identified the most common mammographic faults highlighting possible training needs. We suggest further work to provide a consensus list of visual criteria with accurate descriptors for each classification category. A validated way of applying them could help to standardise the process. - Highlights: • No previous published work comparing PGMI use between different countries. • Variation in number of assessment criteria used and their interpretation. • Best agreement was Norway scoring MLO views from both centres-moderate. • Least agreement was UK raters scoring CC views from both

  4. Ab initio protein structure assembly using continuous structure fragments and optimized knowledge-based force field.

    Science.gov (United States)

    Xu, Dong; Zhang, Yang

    2012-07-01

    Ab initio protein folding is one of the major unsolved problems in computational biology owing to the difficulties in force field design and conformational search. We developed a novel program, QUARK, for template-free protein structure prediction. Query sequences are first broken into fragments of 1-20 residues where multiple fragment structures are retrieved at each position from unrelated experimental structures. Full-length structure models are then assembled from fragments using replica-exchange Monte Carlo simulations, which are guided by a composite knowledge-based force field. A number of novel energy terms and Monte Carlo movements are introduced and the particular contributions to enhancing the efficiency of both force field and search engine are analyzed in detail. QUARK prediction procedure is depicted and tested on the structure modeling of 145 nonhomologous proteins. Although no global templates are used and all fragments from experimental structures with template modeling score >0.5 are excluded, QUARK can successfully construct 3D models of correct folds in one-third cases of short proteins up to 100 residues. In the ninth community-wide Critical Assessment of protein Structure Prediction experiment, QUARK server outperformed the second and third best servers by 18 and 47% based on the cumulative Z-score of global distance test-total scores in the FM category. Although ab initio protein folding remains a significant challenge, these data demonstrate new progress toward the solution of the most important problem in the field. Copyright © 2012 Wiley Periodicals, Inc.

  5. Ab initio lattice dynamics of metal surfaces

    International Nuclear Information System (INIS)

    Heid, R.; Bohnen, K.-P.

    2003-01-01

    Dynamical properties of atoms on surfaces depend sensitively on their bonding environment and thus provide valuable insight into the local geometry and chemical binding at the boundary of a solid. Density-functional theory provides a unified approach to the calculation of structural and dynamical properties from first principles. Its high accuracy and predictive power for lattice dynamical properties of semiconductor surfaces has been demonstrated in a previous article by Fritsch and Schroeder (Phys. Rep. 309 (1999) 209). In this report, we review the state-of-the-art of these ab initio approaches to surface dynamical properties of metal surfaces. We give a brief introduction to the conceptual framework with focus on recent advances in computational procedures for the ab initio linear-response approach, which have been a prerequisite for an efficient treatment of surface dynamics of noble and transition metals. The discussed applications to clean and adsorbate-covered surfaces demonstrate the high accuracy and reliability of this approach in predicting detailed microscopic properties of the phonon dynamics for a wide range of metallic surfaces

  6. Diet quality as assessed by the Healthy Eating Index, the Alternate Healthy Eating Index, the Dietary Approaches to Stop Hypertension score, and health outcomes: a systematic review and meta-analysis of cohort studies.

    Science.gov (United States)

    Schwingshackl, Lukas; Hoffmann, Georg

    2015-05-01

    Dietary patterns consider synergistic effects compared with isolated foods or nutrients on health outcomes. The aim of this systematic review and meta-analysis was to examine the associations of diet quality as assessed by the Healthy Eating Index (HEI), the Alternate Healthy Eating Index (AHEI), and the Dietary Approaches to Stop Hypertension (DASH) score and the risk of all-cause mortality, cardiovascular mortality or incidence, cancer mortality or incidence, type 2 diabetes mellitus, and neurodegenerative diseases. A literature search was performed using the electronic databases MEDLINE, SCOPUS, and EMBASE with an end date of May 10, 2014. Study-specific risk ratios were pooled using a random effect model by the Cochrane software package Review Manager 5.2. Fifteen cohort studies (34 reports), including 1,020,642 subjects, met the criteria and were included in the meta-analysis. Diets of the highest quality, as assessed by the HEI, AHEI, and DASH score, resulted in a significant risk reduction (RR) for all-cause mortality (RR 0.78, 95% CI 0.76 to 0.80; PDiets that score highly on the HEI, AHEI, and DASH are associated with a significant reduction in the risk of all-cause mortality, cardiovascular disease, cancer, and type 2 diabetes mellitus by 22%, 22%, 15%, and 22%, respectively, and therefore is of high public health relevance. Copyright © 2015 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  7. Systematic review of the QoR-15 score, a patient- reported outcome measure measuring quality of recovery after surgery and anaesthesia

    DEFF Research Database (Denmark)

    Kleif, J; Waage, J; Christensen, K B

    2018-01-01

    patients undergoing a variety of surgical elective procedures. The QoR-15 was validated in English, Danish, Chinese, and Portuguese. High-quality evidence for good content validity, good internal consistency (Cronbach's α of 0.836), and essential unidimensionality of the QoR-15 as a measurement...

  8. Allegheny County Walk Scores

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Walk Score measures the walkability of any address using a patented system developed by the Walk Score company. For each 2010 Census Tract centroid, Walk Score...

  9. D-score: a search engine independent MD-score.

    Science.gov (United States)

    Vaudel, Marc; Breiter, Daniela; Beck, Florian; Rahnenführer, Jörg; Martens, Lennart; Zahedi, René P

    2013-03-01

    While peptides carrying PTMs are routinely identified in gel-free MS, the localization of the PTMs onto the peptide sequences remains challenging. Search engine scores of secondary peptide matches have been used in different approaches in order to infer the quality of site inference, by penalizing the localization whenever the search engine similarly scored two candidate peptides with different site assignments. In the present work, we show how the estimation of posterior error probabilities for peptide candidates allows the estimation of a PTM score called the D-score, for multiple search engine studies. We demonstrate the applicability of this score to three popular search engines: Mascot, OMSSA, and X!Tandem, and evaluate its performance using an already published high resolution data set of synthetic phosphopeptides. For those peptides with phosphorylation site inference uncertainty, the number of spectrum matches with correctly localized phosphorylation increased by up to 25.7% when compared to using Mascot alone, although the actual increase depended on the fragmentation method used. Since this method relies only on search engine scores, it can be readily applied to the scoring of the localization of virtually any modification at no additional experimental or in silico cost. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Ab initio derivation of model energy density functionals

    International Nuclear Information System (INIS)

    Dobaczewski, Jacek

    2016-01-01

    I propose a simple and manageable method that allows for deriving coupling constants of model energy density functionals (EDFs) directly from ab initio calculations performed for finite fermion systems. A proof-of-principle application allows for linking properties of finite nuclei, determined by using the nuclear nonlocal Gogny functional, to the coupling constants of the quasilocal Skyrme functional. The method does not rely on properties of infinite fermion systems but on the ab initio calculations in finite systems. It also allows for quantifying merits of different model EDFs in describing the ab initio results. (letter)

  11. Ab initio electronic stopping power in materials

    International Nuclear Information System (INIS)

    Shukri, Abdullah-Atef

    2015-01-01

    The average energy loss of an ion per unit path length when it is moving through the matter is named the stopping power. The knowledge of the stopping power is essential for a variety of contemporary applications which depend on the transport of ions in matter, especially ion beam analysis techniques and ion implantation. Most noticeably, the use of proton or heavier ion beams in radiotherapy requires the knowledge of the stopping power. Whereas experimental data are readily available for elemental solids, the data are much more scarce for compounds. The linear response dielectric formalism has been widely used in the past to study the electronic stopping power. In particular, the famous pioneering calculations due to Lindhard evaluate the electronic stopping power of a free electron gas. In this thesis, we develop a fully ab initio scheme based on linear response time-dependent density functional theory to predict the impact parameter averaged quantity named the random electronic stopping power (RESP) of materials without any empirical fitting. The purpose is to be capable of predicting the outcome of experiments without any knowledge of target material besides its crystallographic structure. Our developments have been done within the open source ab initio code named ABINIT, where two approximations are now available: the Random-Phase Approximation (RPA) and the Adiabatic Local Density Approximation (ALDA). Furthermore, a new method named 'extrapolation scheme' have been introduced to overcome the stringent convergence issues we have encountered. These convergence issues have prevented the previous studies in literature from offering a direct comparison to experiment. First of all, we demonstrate the importance of describing the realistic ab initio electronic structure by comparing with the historical Lindhard stopping power evaluation. Whereas the Lindhard stopping power provides a first order description that captures the general features of the

  12. A comparison between the first-fit settings of two multichannel digital signal-processing strategies: music quality ratings and speech-in-noise scores.

    Science.gov (United States)

    Higgins, Paul; Searchfield, Grant; Coad, Gavin

    2012-06-01

    The aim of this study was to determine which level-dependent hearing aid digital signal-processing strategy (DSP) participants preferred when listening to music and/or performing a speech-in-noise task. Two receiver-in-the-ear hearing aids were compared: one using 32-channel adaptive dynamic range optimization (ADRO) and the other wide dynamic range compression (WDRC) incorporating dual fast (4 channel) and slow (15 channel) processing. The manufacturers' first-fit settings based on participants' audiograms were used in both cases. Results were obtained from 18 participants on a quick speech-in-noise (QuickSIN; Killion, Niquette, Gudmundsen, Revit, & Banerjee, 2004) task and for 3 music listening conditions (classical, jazz, and rock). Participants preferred the quality of music and performed better at the QuickSIN task using the hearing aids with ADRO processing. A potential reason for the better performance of the ADRO hearing aids was less fluctuation in output with change in sound dynamics. ADRO processing has advantages for both music quality and speech recognition in noise over the multichannel WDRC processing that was used in the study. Further evaluations of which DSP aspects contribute to listener preference are required.

  13. Ab initio calculation of intermolecular potentials for dimer Cl_2-Cl_2 and prediction of second virial coefficients

    International Nuclear Information System (INIS)

    Nguyen Thanh Duoc; Nguyen Thi Ai Nhung; Tran Duong; Pham Van Tat

    2015-01-01

    The results presented in this paper are the ab initio intermolecular potentials and the second virial coefficient, B_2 (T) of the dimer Cl_2-Cl_2. These ab initio potentials were proposed by the quantum chemical calculations at high level of theory CCSD(T) with basis sets of Dunning valence correlation-consistent aug-cc-pVmZ (m = 2, 3); these results were extrapolated to complete basis set limit aug-cc-pV23Z. The ab initio energies of complete basis set limit aug-cc-pV23Z resulted from the exponential extrapolation were used to construct the 5-site pair potential functions. The second virial coefficients for this dimer were predicted from those with four-dimensional integration. The second virial coefficients were also corrected to first-order quantum effects. The results turn out to be in good agreement with experimental data, if available, or with those from empirical correlation. The quality of ab initio 5-site potentials proved the reliability for prediction of molecular thermodynamic properties. (author)

  14. Realization of prediction of materials properties by ab initio ...

    Indian Academy of Sciences (India)

    Unknown

    alization of the results of ab initio molecular dynamics simulation on atom insertion process to C60 and to carbon nanotube ... micro-clusters to estimate absolute highest occupied mo- .... To analyse the observed properties theoretically,.

  15. Ab Initio Predictions of Structures and Densities of Energetic Solids

    National Research Council Canada - National Science Library

    Rice, Betsy M; Sorescu, Dan C

    2004-01-01

    We have applied a powerful simulation methodology known as ab initio crystal prediction to assess the ability of a generalized model of CHNO intermolecular interactions to predict accurately crystal...

  16. Ab Initio Atomistic Thermodynamics for Surfaces: A Primer

    National Research Council Canada - National Science Library

    Rogal, Jutta; Reuter, Karsten

    2006-01-01

    .... These techniques are referred to as first-principles (or in latin: ab initio) to indicate that they do not rely on empirical or fitted parameters, which then makes them applicable for a wide range of realistic conditions...

  17. Among 4 Diet Quality Indexes, Only the Alternate Mediterranean Diet Score Is Associated with Better Colorectal Cancer Survival and Only in African American Women in the Multiethnic Cohort123

    Science.gov (United States)

    Jacobs, Simone; Harmon, Brook E; Ollberding, Nicholas J; Wilkens, Lynne R; Monroe, Kristine R; Kolonel, Laurence N; Le Marchand, Loic; Boushey, Carol J; Maskarinec, Gertraud

    2016-01-01

    Background: Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States, with a 5-y survival rate of ∼65%. Therefore, the identification of modifiable health factors to improve CRC survival is crucial. Objective: We investigated the association of 4 prediagnostic a priori diet quality indexes with CRC-specific and all-cause mortality in the Multiethnic Cohort (MEC). Methods: The MEC included >215,000 African-American, Native Hawaiian, Japanese-American, Latino, and white adults living in Hawaii and California who completed a validated quantitative food-frequency questionnaire in 1993–1996. CRC cases and deaths were identified through linkages to cancer registries and to state and national vital registries. Sex-specific HRs and 95% CIs were estimated for the Healthy Eating Index (HEI) 2010, the Alternative HEI (AHEI) 2010, the alternate Mediterranean Diet (aMED) score, and the Dietary Approaches to Stop Hypertension (DASH) index with CRC-specific and overall mortality as the primary outcomes. Ethnicity-specific analyses were the secondary outcomes. Results: Among 4204 MEC participants diagnosed with invasive CRC through 2010, 1976 all-cause and 1095 CRC-specific deaths were identified. A higher aMED score was associated with lower CRC-specific mortality in women [HR continuous pattern score divided by its respective SD (HR1SD): 0.86; 95% CI: 0.77, 0.96] but not in men (HR1SD: 1.01; 95% CI: 0.92, 1.11). A higher aMED score was also associated with lower all-cause mortality in women (HR1SD: 0.88; 95% CI: 0.81, 0.96) but not in men (HR1SD: 1.00; 95% CI: 0.93, 1.07). The HEI-2010, AHEI-2010, and DASH index were not significantly associated with CRC-specific or with all-cause mortality. The inverse relation for the aMED score was limited to African Americans and to colon (compared with rectal) cancer. Conclusions: The aMED score was related to lower mortality only in African-American women (1 of 5 ethnic groups studied). The

  18. Quality

    International Nuclear Information System (INIS)

    Burnett, N.; Jeffries, J.; Mach, J.; Robson, M.; Pajot, D.; Harrigan, J.; Lebsack, T.; Mullen, D.; Rat, F.; Theys, P.

    1993-01-01

    What is quality? How do you achieve it? How do you keep it once you have got it. The answer for industry at large is the three-step hierarchy of quality control, quality assurance and Total quality Management. An overview is given of the history of quality movement, illustrated with examples from Schlumberger operations, as well as the oil industry's approach to quality. An introduction of the Schlumberger's quality-associated ClientLink program is presented. 15 figs., 4 ills., 16 refs

  19. Reference bias: presentation of extreme health states prior to eq-vas improves health-related quality of life scores. a randomised cross-over trial

    Directory of Open Access Journals (Sweden)

    McPhail Steven

    2010-12-01

    Full Text Available Abstract Background Clinical practice and clinical research has made a concerted effort to move beyond the use of clinical indicators alone and embrace patient focused care through the use of patient reported outcomes such as health-related quality of life. However, unless patients give consistent consideration to the health states that give meaning to measurement scales used to evaluate these constructs, longitudinal comparison of these measures may be invalid. This study aimed to investigate whether patients give consideration to a standard health state rating scale (EQ-VAS and whether consideration of good and poor health state descriptors immediately changes their self-report. Methods A randomised crossover trial was implemented amongst hospitalised older adults (n = 151. Patients were asked to consider descriptions of extremely good (Description-A and poor (Description-B health states. The EQ-VAS was administered as a self-report at baseline, after the first descriptors (A or B, then again after the remaining descriptors (B or A respectively. At baseline patients were also asked if they had considered either EQ-VAS anchors. Results Overall 106/151 (70% participants changed their self-evaluation by ≥5 points on the 100 point VAS, with a mean (SD change of +4.5 (12 points (p Conclusions Health state self-reports may not be well considered. An immediate significant shift in response can be elicited by exposure to a mere description of an extreme health state despite no actual change in underlying health state occurring. Caution should be exercised in research and clinical settings when interpreting subjective patient reported outcomes that are dependent on brief anchors for meaning. Trial Registration Australian and New Zealand Clinical Trials Registry (#ACTRN12607000606482 http://www.anzctr.org.au

  20. Impact of the occurrence of a response shift on the determination of the minimal important difference in a health-related quality of life score over time.

    Science.gov (United States)

    Ousmen, Ahmad; Conroy, Thierry; Guillemin, Francis; Velten, Michel; Jolly, Damien; Mercier, Mariette; Causeret, Sylvain; Cuisenier, Jean; Graesslin, Olivier; Hamidou, Zeinab; Bonnetain, Franck; Anota, Amélie

    2016-12-03

    An important challenge of the longitudinal analysis of health-related quality of life (HRQOL) is the potential occurrence of a Response Shift (RS) effect. While the impact of RS effect on the longitudinal analysis of HRQOL has already been studied, few studies have been conducted on its impact on the determination of the Minimal Important Difference (MID). This study aims to investigate the impact of the RS effect on the determination of the MID over time for each scale of both EORTC QLQ-C30 and QLQ-BR23 questionnaires in breast cancer patients. Patients with breast cancer completed the EORTC QLQ-C30 and the EORTC QLQ-BR23 questionnaires at baseline (time of diagnosis; T0), three months (T1) and six months after surgery (T2). Four hospitals and care centers participated in this study: cancer centers of Dijon and Nancy, the university hospitals of Reims and Strasbourg At T1 and T2, patients were asked to evaluate their HRQOL change during the last 3 months using the Jaeschke transition question. They were also asked to assess retrospectively their HRQOL level of three months ago. The occurrence of the RS effect was explored using the then-test method and its impact on the determination of the MID by using the Anchor-based method. Between February 2006 and February 2008, 381 patients were included of mean age 58 years old (SD = 11). For patients who reported a deterioration of their HRQOL level at each follow-up, an increase of RS effect has been detected between T1 and T2 in 13/15 dimensions of QLQ-C30 questionnaire, and 4/7 dimensions of QLQ-BR23 questionnaire. In contrast, a decrease of the RS effect was observed in 8/15 dimensions of QLQ-C30 questionnaire and in 5/7 dimensions of QLQ-BR23 questionnaire in case of improvement. At T2, the MID became ≥ 5 points when taking into account the RS effect in 10/15 dimensions of QLQ-C30 questionnaire and in 5/7 dimensions of QLQ-BR23 questionnaire. This study highlights that the RS effect increases over time in

  1. Ab initio calculation of the shear viscosity of neon in the liquid and hypercritical state over a wide pressure and temperature range

    Science.gov (United States)

    Eggenberger, Rolf; Gerber, Stefan; Huber, Hanspeter; Searles, Debra; Welker, Marc

    1992-08-01

    The shear viscosity is calculated ab initio for the liquid and hypercritical state, i.e. a previously published potential for Ne 2, obtained from ab initio calculations including electron correlation, is used in classical equilibrium molecular dynamics simulations to obtain the shear viscosity from a Green-Kubo integral. The quality of the results is quite uniform over a large pressure range up to 1000 MPa and a wide temperature range from 26 to 600 K. In most cases the calculated shear viscosity deviates by less than 10% from the experimental value, in general the error being only a few percent.

  2. The Zhongshan Score

    Science.gov (United States)

    Zhou, Lin; Guo, Jianming; Wang, Hang; Wang, Guomin

    2015-01-01

    Abstract In the zero ischemia era of nephron-sparing surgery (NSS), a new anatomic classification system (ACS) is needed to adjust to these new surgical techniques. We devised a novel and simple ACS, and compared it with the RENAL and PADUA scores to predict the risk of NSS outcomes. We retrospectively evaluated 789 patients who underwent NSS with available imaging between January 2007 and July 2014. Demographic and clinical data were assessed. The Zhongshan (ZS) score consisted of three parameters. RENAL, PADUA, and ZS scores are divided into three groups, that is, high, moderate, and low scores. For operative time (OT), significant differences were seen between any two groups of ZS score and PADUA score (all P RENAL showed no significant difference between moderate and high complexity in OT, WIT, estimated blood loss, and increase in SCr. Compared with patients with a low score of ZS, those with a high or moderate score had 8.1-fold or 3.3-fold higher risk of surgical complications, respectively (all P RENAL score, patients with a high or moderate score had 5.7-fold or 1.9-fold higher risk of surgical complications, respectively (all P RENAL and PADUA scores. ZS score could be used to reflect the surgical complexity and predict the risk of surgical complications in patients undergoing NSS. PMID:25654399

  3. Phonocatalysis. An ab initio simulation experiment

    Directory of Open Access Journals (Sweden)

    Kwangnam Kim

    2016-06-01

    Full Text Available Using simulations, we postulate and show that heterocatalysis on large-bandgap semiconductors can be controlled by substrate phonons, i.e., phonocatalysis. With ab initio calculations, including molecular dynamic simulations, the chemisorbed dissociation of XeF6 on h-BN surface leads to formation of XeF4 and two surface F/h-BN bonds. The reaction pathway and energies are evaluated, and the sorption and reaction emitted/absorbed phonons are identified through spectral analysis of the surface atomic motion. Due to large bandgap, the atomic vibration (phonon energy transfer channels dominate and among them is the match between the F/h-BN covalent bond stretching and the optical phonons. We show that the chemisorbed dissociation (the pathway activation ascent requires absorption of large-energy optical phonons. Then using progressively heavier isotopes of B and N atoms, we show that limiting these high-energy optical phonons inhibits the chemisorbed dissociation, i.e., controllable phonocatalysis.

  4. Integration of QUARK and I-TASSER for Ab Initio Protein Structure Prediction in CASP11.

    Science.gov (United States)

    Zhang, Wenxuan; Yang, Jianyi; He, Baoji; Walker, Sara Elizabeth; Zhang, Hongjiu; Govindarajoo, Brandon; Virtanen, Jouko; Xue, Zhidong; Shen, Hong-Bin; Zhang, Yang

    2016-09-01

    We tested two pipelines developed for template-free protein structure prediction in the CASP11 experiment. First, the QUARK pipeline constructs structure models by reassembling fragments of continuously distributed lengths excised from unrelated proteins. Five free-modeling (FM) targets have the model successfully constructed by QUARK with a TM-score above 0.4, including the first model of T0837-D1, which has a TM-score = 0.736 and RMSD = 2.9 Å to the native. Detailed analysis showed that the success is partly attributed to the high-resolution contact map prediction derived from fragment-based distance-profiles, which are mainly located between regular secondary structure elements and loops/turns and help guide the orientation of secondary structure assembly. In the Zhang-Server pipeline, weakly scoring threading templates are re-ordered by the structural similarity to the ab initio folding models, which are then reassembled by I-TASSER based structure assembly simulations; 60% more domains with length up to 204 residues, compared to the QUARK pipeline, were successfully modeled by the I-TASSER pipeline with a TM-score above 0.4. The robustness of the I-TASSER pipeline can stem from the composite fragment-assembly simulations that combine structures from both ab initio folding and threading template refinements. Despite the promising cases, challenges still exist in long-range beta-strand folding, domain parsing, and the uncertainty of secondary structure prediction; the latter of which was found to affect nearly all aspects of FM structure predictions, from fragment identification, target classification, structure assembly, to final model selection. Significant efforts are needed to solve these problems before real progress on FM could be made. Proteins 2016; 84(Suppl 1):76-86. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  5. The association between health-related quality-of-life scores and clinical outcomes in metastatic castration-resistant prostate cancer patients: Exploratory analyses of AFFIRM and PREVAIL studies.

    Science.gov (United States)

    Beer, Tomasz M; Miller, Kurt; Tombal, Bertrand; Cella, David; Phung, De; Holmstrom, Stefan; Ivanescu, Cristina; Skaltsa, Konstantina; Naidoo, Shevani

    2017-12-01

    Our exploratory analysis examined the association between health-related quality of life (HRQoL) (baseline and change over time) and clinical outcomes (overall survival [OS]/radiographic progression-free survival [rPFS]) in metastatic castration-resistant prostate cancer (mCRPC). HRQoL, OS and rPFS were assessed in phase III trials comparing enzalutamide with placebo in chemotherapy-naïve (PREVAIL; NCT01212991) or post-chemotherapy (AFFIRM; NCT00974311) mCRPC. HRQoL was assessed using the Functional Assessment of Cancer Therapy-Prostate (FACT-P). Multivariate analyses evaluated the prognostic significance of baseline and time-dependent scores after adjusting for treatment and clinical/demographic variables. Hazard ratios (HRs) and 95% confidence intervals (CIs) represented the hazard of rPFS or OS per minimally important difference (MID) score change in HRQoL variables. In baseline and time-dependent multivariate analyses, OS was independently associated with multiple HRQoL measures across both studies. In time-dependent analyses, a 10-point (upper bound of MID range) increase (improvement) in FACT-P total score was associated with reductions in mortality risk of 19% in AFFIRM (HR 0.81 [95% CI 0.78-0.84]) and 21% in PREVAIL (HR 0.79 [0.76-0.83]). For baseline analyses, a 10-point increase in FACT-P total score was associated with reductions in mortality risk of 12% (HR 0.88 [0.84-0.93]) and 10% (HR 0.90 [0.86-0.95]) in AFFIRM and PREVAIL, respectively. rPFS was associated with a subset of HRQoL domains in both studies. Several baseline HRQoL domains were prognostic for rPFS and OS in patients with mCRPC, and this association was maintained during treatment, indicating that changes in HRQoL are informative for patients' expected survival. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Introducing ab initio based neural networks for transition-rate prediction in kinetic Monte Carlo simulations

    Science.gov (United States)

    Messina, Luca; Castin, Nicolas; Domain, Christophe; Olsson, Pär

    2017-02-01

    The quality of kinetic Monte Carlo (KMC) simulations of microstructure evolution in alloys relies on the parametrization of point-defect migration rates, which are complex functions of the local chemical composition and can be calculated accurately with ab initio methods. However, constructing reliable models that ensure the best possible transfer of physical information from ab initio to KMC is a challenging task. This work presents an innovative approach, where the transition rates are predicted by artificial neural networks trained on a database of 2000 migration barriers, obtained with density functional theory (DFT) in place of interatomic potentials. The method is tested on copper precipitation in thermally aged iron alloys, by means of a hybrid atomistic-object KMC model. For the object part of the model, the stability and mobility properties of copper-vacancy clusters are analyzed by means of independent atomistic KMC simulations, driven by the same neural networks. The cluster diffusion coefficients and mean free paths are found to increase with size, confirming the dominant role of coarsening of medium- and large-sized clusters in the precipitation kinetics. The evolution under thermal aging is in better agreement with experiments with respect to a previous interatomic-potential model, especially concerning the experiment time scales. However, the model underestimates the solubility of copper in iron due to the excessively high solution energy predicted by the chosen DFT method. Nevertheless, this work proves the capability of neural networks to transfer complex ab initio physical properties to higher-scale models, and facilitates the extension to systems with increasing chemical complexity, setting the ground for reliable microstructure evolution simulations in a wide range of alloys and applications.

  7. Use of ab initio quantum chemical methods in battery technology

    Energy Technology Data Exchange (ETDEWEB)

    Deiss, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Ab initio quantum chemistry can nowadays predict physical and chemical properties of molecules and solids. An attempt should be made to use this tool more widely for predicting technologically favourable materials. To demonstrate the use of ab initio quantum chemistry in battery technology, the theoretical energy density (energy per volume of active electrode material) and specific energy (energy per mass of active electrode material) of a rechargeable lithium-ion battery consisting of a graphite electrode and a nickel oxide electrode has been calculated with this method. (author) 1 fig., 1 tab., 7 refs.

  8. How to score questionnaires

    NARCIS (Netherlands)

    Hofstee, W.K.B.; Ten Berge, J.M.F.; Hendriks, A.A.J.

    The standard practice in scoring questionnaires consists of adding item scores and standardizing these sums. We present a set of alternative procedures, consisting of (a) correcting for the acquiescence variance that disturbs the structure of the questionnaire; (b) establishing item weights through

  9. SCORE - A DESCRIPTION.

    Science.gov (United States)

    SLACK, CHARLES W.

    REINFORCEMENT AND ROLE-REVERSAL TECHNIQUES ARE USED IN THE SCORE PROJECT, A LOW-COST PROGRAM OF DELINQUENCY PREVENTION FOR HARD-CORE TEENAGE STREET CORNER BOYS. COMMITTED TO THE BELIEF THAT THE BOYS HAVE THE POTENTIAL FOR ETHICAL BEHAVIOR, THE SCORE WORKER FOLLOWS B.F. SKINNER'S THEORY OF OPERANT CONDITIONING AND REINFORCES THE DELINQUENT'S GOOD…

  10. Speed-up of ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo simulations by using an auxiliary potential energy surface

    International Nuclear Information System (INIS)

    Nakayama, Akira; Taketsugu, Tetsuya; Shiga, Motoyuki

    2009-01-01

    Efficiency of the ab initio hybrid Monte Carlo and ab initio path integral hybrid Monte Carlo methods is enhanced by employing an auxiliary potential energy surface that is used to update the system configuration via molecular dynamics scheme. As a simple illustration of this method, a dual-level approach is introduced where potential energy gradients are evaluated by computationally less expensive ab initio electronic structure methods. (author)

  11. The Bandim tuberculosis score

    DEFF Research Database (Denmark)

    Rudolf, Frauke; Joaquim, Luis Carlos; Vieira, Cesaltina

    2013-01-01

    Background: This study was carried out in Guinea-Bissau ’ s capital Bissau among inpatients and outpatients attending for tuberculosis (TB) treatment within the study area of the Bandim Health Project, a Health and Demographic Surveillance Site. Our aim was to assess the variability between 2...... physicians in performing the Bandim tuberculosis score (TBscore), a clinical severity score for pulmonary TB (PTB), and to compare it to the Karnofsky performance score (KPS). Method : From December 2008 to July 2009 we assessed the TBscore and the KPS of 100 PTB patients at inclusion in the TB cohort and...

  12. AB INITIO calculations of magneto-optical effects

    Czech Academy of Sciences Publication Activity Database

    Kuneš, Jan; Oppeneer, P. M.

    2002-01-01

    Roč. 2, - (2002), s. 141-146 ISSN 1346-7948 R&D Projects: GA AV ČR IAA1010214 Institutional research plan: CEZ:AV0Z1010914 Keywords : electronic structure * ab initio calculation * polar magneto-optical Kerr effect * transitiom metal * uranium intermetallics * CrO 2 Subject RIV: BM - Solid Matter Physics ; Magnetism

  13. Early stage precipitation in aluminum alloys : An ab initio study

    NARCIS (Netherlands)

    Zhang, X.

    2017-01-01

    Multiscale computational materials science has reached a stage where many complicated phenomena or properties that are of great importance to manufacturing can be predicted or explained. The word “ab initio study” becomes commonplace as the development of density functional theory has enabled the

  14. Ab initio molecular dynamics simulation of laser melting of silicon

    NARCIS (Netherlands)

    Silvestrelli, P.-L.; Alavi, A.; Parrinello, M.; Frenkel, D.

    1996-01-01

    The method of ab initio molecular dynamics, based on finite temperature density functional theory, is used to simulate laser heating of crystal silicon. We have found that a high concentration of excited electrons dramatically weakens the covalent bond. As a result, the system undergoes a melting

  15. Multiple time step integrators in ab initio molecular dynamics

    International Nuclear Information System (INIS)

    Luehr, Nathan; Martínez, Todd J.; Markland, Thomas E.

    2014-01-01

    Multiple time-scale algorithms exploit the natural separation of time-scales in chemical systems to greatly accelerate the efficiency of molecular dynamics simulations. Although the utility of these methods in systems where the interactions are described by empirical potentials is now well established, their application to ab initio molecular dynamics calculations has been limited by difficulties associated with splitting the ab initio potential into fast and slowly varying components. Here we present two schemes that enable efficient time-scale separation in ab initio calculations: one based on fragment decomposition and the other on range separation of the Coulomb operator in the electronic Hamiltonian. We demonstrate for both water clusters and a solvated hydroxide ion that multiple time-scale molecular dynamics allows for outer time steps of 2.5 fs, which are as large as those obtained when such schemes are applied to empirical potentials, while still allowing for bonds to be broken and reformed throughout the dynamics. This permits computational speedups of up to 4.4x, compared to standard Born-Oppenheimer ab initio molecular dynamics with a 0.5 fs time step, while maintaining the same energy conservation and accuracy

  16. Cyanogen Azide. Ionization Potentials and Ab Initio SCF MO Calculation

    DEFF Research Database (Denmark)

    Bak, Börge; Jansen, Peter; Stafast, Herbert

    1975-01-01

    The Ne(I) and He(I) photoelectron(PE) spectra of cyanogen azide, NCN3, have been recorded at high resolution. Their interpretation is achieved by comparison with the PE spectrum of HN3 and an ab initio LCGO SCF MO calculation. Deviations from Koopmans' theorem of quite different magnitudes...

  17. Ab initio study of alanine polypeptide chain twisting

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    chains. These particular degrees of freedom are essential for the characterization of the proteins folding process. Calculations have been carried out within the ab initio theoretical framework based on the density functional theory and accounting for all the electrons in the system. We have determined...

  18. Ab initio simulation of dislocation cores in metals

    International Nuclear Information System (INIS)

    Ventelon, L.

    2008-01-01

    In the framework of the multi scale simulation of metals and alloys plasticity, the aim of this study is to develop a methodology of ab initio dislocations study and to apply it to the [111] screw dislocation in the bc iron. (A.L.B.)

  19. Young Modulus of Crystalline Polyethylene from ab Initio Molecular Dynamics

    NARCIS (Netherlands)

    Hageman, J.C.L.; Meier, Robert J.; Heinemann, M.; Groot, R.A. de

    1997-01-01

    The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa.

  20. Ab initio electronic properties of dual phosphorus monolayers in silicon

    DEFF Research Database (Denmark)

    Drumm, Daniel W.; Per, Manolo C.; Budi, Akin

    2014-01-01

    In the midst of the epitaxial circuitry revolution in silicon technology, we look ahead to the next paradigm shift: effective use of the third dimension - in particular, its combination with epitaxial technology. We perform ab initio calculations of atomically thin epitaxial bilayers in silicon...

  1. Quantifying transition voltage spectroscopy of molecular junctions: Ab initio calculations

    DEFF Research Database (Denmark)

    Chen, Jingzhe; Markussen, Troels; Thygesen, Kristian Sommer

    2010-01-01

    Transition voltage spectroscopy (TVS) has recently been introduced as a spectroscopic tool for molecular junctions where it offers the possibility to probe molecular level energies at relatively low bias voltages. In this work we perform extensive ab initio calculations of the nonlinear current...

  2. Ab initio study of phase equilibria in TiCx

    DEFF Research Database (Denmark)

    Korzhavyi, P.A.; Pourovskii, L.V.; Hugosson, H.W.

    2002-01-01

    The phase diagram for the vacancy-ordered structures in the substoichiometric TiCx (x = 0.5-1.0) has been established from Monte Carlo simulations with the long-range pair and multisite effective interactions obtained from ab initio calculations. Three ordered superstructures of vacancies (Ti2C, Ti...

  3. Ab initio and kinetic modeling studies of formic acid oxidation

    DEFF Research Database (Denmark)

    Marshall, Paul; Glarborg, Peter

    2015-01-01

    A detailed chemical kinetic model for oxidation of formic acid (HOCHO) in flames has been developed, based on theoretical work and data from literature. Ab initio calculations were used to obtain rate coefficients for reactions of HOCHO with H, O, and HO2. Modeling predictions with the mechanism...

  4. Ab initio calculations and modelling of atomic cluster structure

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Lyalin, Andrey G.; Solov'yov, Andrey V.

    2004-01-01

    The optimized structure and electronic properties of small sodium and magnesium clusters have been investigated using it ab initio theoretical methods based on density-functional theory and post-Hartree-Fock many-body perturbation theory accounting for all electrons in the system. A new theoretical...

  5. Bicanonical ab Initio Molecular Dynamics for Open Systems.

    Science.gov (United States)

    Frenzel, Johannes; Meyer, Bernd; Marx, Dominik

    2017-08-08

    Performing ab initio molecular dynamics simulations of open systems, where the chemical potential rather than the number of both nuclei and electrons is fixed, still is a challenge. Here, drawing on bicanonical sampling ideas introduced two decades ago by Swope and Andersen [ J. Chem. Phys. 1995 , 102 , 2851 - 2863 ] to calculate chemical potentials of liquids and solids, an ab initio simulation technique is devised, which introduces a fictitious dynamics of two superimposed but otherwise independent periodic systems including full electronic structure, such that either the chemical potential or the average fractional particle number of a specific chemical species can be kept constant. As proof of concept, we demonstrate that solvation free energies can be computed from these bicanonical ab initio simulations upon directly superimposing pure bulk water and the respective aqueous solution being the two limiting systems. The method is useful in many circumstances, for instance for studying heterogeneous catalytic processes taking place on surfaces where the chemical potential of reactants rather than their number is controlled and opens a pathway toward ab initio simulations at constant electrochemical potential.

  6. Ab initio calculations of mechanical properties: Methods and applications

    Czech Academy of Sciences Publication Activity Database

    Pokluda, J.; Černý, Miroslav; Šob, Mojmír; Umeno, Y.

    2015-01-01

    Roč. 73, AUG (2015), s. 127-158 ISSN 0079-6425 R&D Projects: GA ČR(CZ) GAP108/12/0311 Institutional support: RVO:68081723 Keywords : Ab initio methods * Elastic moduli * Intrinsic hardness * Stability analysis * Theoretical strength * Intrinsic brittleness/ductility Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 31.083, year: 2015

  7. The Properties of Some Simple Covalent Hydrides: An Ab Initio ...

    African Journals Online (AJOL)

    Some properties of the monomeric binary hydrides of the elements of the first two rows of the periodic table have been determined using ab initio molecular orbital theory. The properties in question are the energetic, structural, electronic, topological and vibrational characteristics. In general, a gradual convergence towards ...

  8. Hydrogen Bond Dynamics in Aqueous Solutions: Ab initio Molecular ...

    Indian Academy of Sciences (India)

    Rate equation for the decay of CHB(t) · Definition of Hydrogen Bonds · Results of Molecular Dynamics · Dynamics of anion-water and water-water hydrogen bonds · Structural relaxation of anion-water & water-water H-bonds · Ab initio Molecular Dynamics : · Slide 14 · Dynamics of hydrogen bonds : CPMD results · Slide 16.

  9. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh; Rungger, Ivan; Droghetti, Andrea; Sanvito, Stefano

    2014-01-01

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results

  10. Volleyball Scoring Systems.

    Science.gov (United States)

    Calhoun, William; Dargahi-Noubary, G. R.; Shi, Yixun

    2002-01-01

    The widespread interest in sports in our culture provides an excellent opportunity to catch students' attention in mathematics and statistics classes. One mathematically interesting aspect of volleyball, which can be used to motivate students, is the scoring system. (MM)

  11. Combination of scoring schemes for protein docking

    Directory of Open Access Journals (Sweden)

    Schomburg Dietmar

    2007-08-01

    Full Text Available Abstract Background Docking algorithms are developed to predict in which orientation two proteins are likely to bind under natural conditions. The currently used methods usually consist of a sampling step followed by a scoring step. We developed a weighted geometric correlation based on optimised atom specific weighting factors and combined them with our previously published amino acid specific scoring and with a comprehensive SVM-based scoring function. Results The scoring with the atom specific weighting factors yields better results than the amino acid specific scoring. In combination with SVM-based scoring functions the percentage of complexes for which a near native structure can be predicted within the top 100 ranks increased from 14% with the geometric scoring to 54% with the combination of all scoring functions. Especially for the enzyme-inhibitor complexes the results of the ranking are excellent. For half of these complexes a near-native structure can be predicted within the first 10 proposed structures and for more than 86% of all enzyme-inhibitor complexes within the first 50 predicted structures. Conclusion We were able to develop a combination of different scoring schemes which considers a series of previously described and some new scoring criteria yielding a remarkable improvement of prediction quality.

  12. PM10 and gaseous pollutants trends from air quality monitoring networks in Bari province: principal component analysis and absolute principal component scores on a two years and half data set

    Science.gov (United States)

    2014-01-01

    Background The chemical composition of aerosols and particle size distributions are the most significant factors affecting air quality. In particular, the exposure to finer particles can cause short and long-term effects on human health. In the present paper PM10 (particulate matter with aerodynamic diameter lower than 10 μm), CO, NOx (NO and NO2), Benzene and Toluene trends monitored in six monitoring stations of Bari province are shown. The data set used was composed by bi-hourly means for all parameters (12 bi-hourly means per day for each parameter) and it’s referred to the period of time from January 2005 and May 2007. The main aim of the paper is to provide a clear illustration of how large data sets from monitoring stations can give information about the number and nature of the pollutant sources, and mainly to assess the contribution of the traffic source to PM10 concentration level by using multivariate statistical techniques such as Principal Component Analysis (PCA) and Absolute Principal Component Scores (APCS). Results Comparing the night and day mean concentrations (per day) for each parameter it has been pointed out that there is a different night and day behavior for some parameters such as CO, Benzene and Toluene than PM10. This suggests that CO, Benzene and Toluene concentrations are mainly connected with transport systems, whereas PM10 is mostly influenced by different factors. The statistical techniques identified three recurrent sources, associated with vehicular traffic and particulate transport, covering over 90% of variance. The contemporaneous analysis of gas and PM10 has allowed underlining the differences between the sources of these pollutants. Conclusions The analysis of the pollutant trends from large data set and the application of multivariate statistical techniques such as PCA and APCS can give useful information about air quality and pollutant’s sources. These knowledge can provide useful advices to environmental policies in

  13. A Systematic Review and Meta-Analysis of a Measure of Staff/Child Interaction Quality (the Classroom Assessment Scoring System) in Early Childhood Education and Care Settings and Child Outcomes.

    Science.gov (United States)

    Perlman, Michal; Falenchuk, Olesya; Fletcher, Brooke; McMullen, Evelyn; Beyene, Joseph; Shah, Prakesh S

    2016-01-01

    The quality of staff/child interactions as measured by the Classroom Assessment Scoring System (CLASS) in Early Childhood Education and Care (ECEC) programs is thought to be important for children's outcomes. The CLASS is made of three domains that assess Emotional Support, Classroom Organization and Instructional Support. It is a relatively new measure that is being used increasingly for research, quality monitoring/accountability and other applied purposes. Our objective was to evaluate the association between the CLASS and child outcomes. Searches of Medline, PsycINFO, ERIC, websites of large datasets and reference sections of all retrieved articles were conducted up to July 3, 2015. Studies that measured association between the CLASS and child outcomes for preschool-aged children who attended ECEC programs were included after screening by two independent reviewers. Searches and data extraction were conducted by two independent reviewers. Thirty-five studies were systematically reviewed of which 19 provided data for meta-analyses. Most studies had moderate to high risk of bias. Of the 14 meta-analyses we conducted, associations between Classroom Organization and Pencil Tapping and between Instructional Support and SSRS Social Skills were significant with pooled correlations of .06 and .09 respectively. All associations were in the expected direction. In the systematic review, significant correlations were reported mainly from one large dataset. Substantial heterogeneity in use of the CLASS, its dimensions, child outcomes and statistical measures was identified. Greater consistency in study methodology is urgently needed. Given the multitude of factors that impact child development it is encouraging that our analyses revealed some, although small, associations between the CLASS and children's outcomes.

  14. Perspective: Ab initio force field methods derived from quantum mechanics

    Science.gov (United States)

    Xu, Peng; Guidez, Emilie B.; Bertoni, Colleen; Gordon, Mark S.

    2018-03-01

    It is often desirable to accurately and efficiently model the behavior of large molecular systems in the condensed phase (thousands to tens of thousands of atoms) over long time scales (from nanoseconds to milliseconds). In these cases, ab initio methods are difficult due to the increasing computational cost with the number of electrons. A more computationally attractive alternative is to perform the simulations at the atomic level using a parameterized function to model the electronic energy. Many empirical force fields have been developed for this purpose. However, the functions that are used to model interatomic and intermolecular interactions contain many fitted parameters obtained from selected model systems, and such classical force fields cannot properly simulate important electronic effects. Furthermore, while such force fields are computationally affordable, they are not reliable when applied to systems that differ significantly from those used in their parameterization. They also cannot provide the information necessary to analyze the interactions that occur in the system, making the systematic improvement of the functional forms that are used difficult. Ab initio force field methods aim to combine the merits of both types of methods. The ideal ab initio force fields are built on first principles and require no fitted parameters. Ab initio force field methods surveyed in this perspective are based on fragmentation approaches and intermolecular perturbation theory. This perspective summarizes their theoretical foundation, key components in their formulation, and discusses key aspects of these methods such as accuracy and formal computational cost. The ab initio force fields considered here were developed for different targets, and this perspective also aims to provide a balanced presentation of their strengths and shortcomings. Finally, this perspective suggests some future directions for this actively developing area.

  15. Epidemiology of Functional abdominal bloating and its impact on health related quality of life: male-female stratified propensity score analysis in a population based survey in mainland China.

    Science.gov (United States)

    Wu, Meijing; Zhao, Yanfang; Wang, Rui; Zheng, Wenxin; Guo, Xiaojing; Wu, Shunquan; Ma, Xiuqiang; He, Jia

    2014-01-01

    The epidemiology of Functional abdominal bloating (FAB) and its impact on health-related quality of life (HRQoL) in Chinese people remains unclear. Randomised, stratified, multi-stage sampling methodology was used to select a representative sample of the general population from five cities in China (n = 16,078). All respondents completed the modified Rome II questionnaire; 20% were asked to complete the 36-item Short Form (SF-36). The associated factors of FAB were analyzed. The effects of FAB on HRQoL were estimated with gender stratification using propensity score techniques in 20% subsample. Overall, 643 individuals (4.00%) had FAB and it was more prevalent in males than in females (4.87% vs. 3.04%, Pproblems (P = 0.030) and bodily pain (PChina was lower than previous reports. Males who had ever been diagnosed with dyspepsia and females who were in a poor self-reported health status were correlated with a higher prevalence of FAB. FAB affected only physical health in females, but impaired both physical and mental health in males.

  16. Development of the siriraj clinical asthma score.

    Science.gov (United States)

    Vichyanond, Pakit; Veskitkul, Jittima; Rienmanee, Nuanphong; Pacharn, Punchama; Jirapongsananuruk, Orathai; Visitsunthorn, Nualanong

    2013-09-01

    Acute asthmatic attack in children commonly occurs despite the introduction of effective controllers such as inhaled corticosteroids and leukotriene modifiers. Treatment of acute asthmatic attack requires proper evaluation of attack severity and appropriate selection of medical therapy. In children, measurement of lung function is difficult during acute attack and thus clinical asthma scoring may aid physician in making further decision regarding treatment and admission. We enrolled 70 children with acute asthmatic attack with age range from 1 to 12 years (mean ± SD = 51.5 ± 31.8 months) into the study. Twelve selected asthma severity items were assessed by 2 independent observers prior to administration of salbutamol nebulization (up to 3 doses at 20 minutes interval). Decision for further therapy and admission was made by emergency department physician. Three different scoring systems were constructed from items with best validity. Sensitivity, specificity and accuracy of these scores were assessed. Inter-rater reliability was assessed for each score. Review of previous scoring systems was also conducted and reported. Three severity items had poor validity, i.e., cyanosis, depressed cerebral function, and I:E ratio (p > 0.05). Three items had poor inter-rater reliability, i.e., breath sound quality, air entry, and I:E ratio. These items were omitted and three new clinical scores were constructed from the remaining items. Clinical scoring system comprised retractions, dyspnea, O2 saturation, respiratory rate and wheezing (rangeof score 0-10) gave the best accuracy and inter-rater variability and were chosen for clinical use-Siriraj Clinical Asthma Score (SCAS). A Clinical Asthma Score that is simple, relatively easy to administer and with good validity and variability is essential for treatment of acute asthma in children. Several good candidate scores have been introduced in the past. We described the development of the Siriraj Clinical Asthma Score (SCAS) in

  17. Ab initio calculation of molecular energies including parity violating interactions

    International Nuclear Information System (INIS)

    Bakasov, A.; Ha Taekyu; Quack, M.

    1995-01-01

    A new approach, RHF-CIS, based on the perturbation of the ground state RHF wave function by the CIS excitations, has been implemented for evaluation of energy of parity violating interaction in molecules, E pv . The earlier approach, RHF-SDE, was based on the perturbation of the RHF ground states by the single-determinant ''excitations'' (SDE). The results obtained show the dramatic difference between E pv values in the RHF-CIS framework and those in the RHF-SDE framework: the E pv values of the RHF-CIS formalism are more than one order of magnitude greater compared to the RHF-SDE formalism as well as the corresponding tensor components. The maximal total value obtained for hydrogen peroxide in the RHF-CIS framework is 3.661 X 10 -19 E H (DZ ** basis set) while the maximal E pv value for the RHF-SDE formalism is just 3.635 X 10 -20 E H (TZ basis set). It is remarkable that both in the RFH-CIS and in the RHF-SDE approaches the diagonal tensor components of E pv strictly follow the geometry of a molecule and are always different from zero at chiral conformations. The zeros of the total E pv at chiral geometries are now found to be the results of the interplay between the diagonal tensor components values. We have carried out exhaustive analysis of the RHF-SDE formalism and found that it is not sufficiently accurate for studies of E pv . To this end, we have completely reproduced the previous work, which has been done in the RHF-SDE frame-work, and developed it further, studying how the RHF-SDE results vary when changing size and quality of basis sets. This last resource does not save the RHF-SDE formalism for evaluations of E pv from the general failure. Packages of FORTRAN routines called ENWEAK/RHFSDE-93 and ENWEAK/RHFCIS-94 have been developed which run on top of an ab initio MO package. We used 6-31G and 6-31G**, DZ and DZ**, TZ and TZ**, and (10s, 6p,**) basis sets. We will discuss the importance of the present results for possible measurement of the parity

  18. Instant MuseScore

    CERN Document Server

    Shinn, Maxwell

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. Instant MuseScore is written in an easy-to follow format, packed with illustrations that will help you get started with this music composition software.This book is for musicians who would like to learn how to notate music digitally with MuseScore. Readers should already have some knowledge about musical terminology; however, no prior experience with music notation software is necessary.

  19. Ab initio configuration interaction description of excitation energy transfer between closely packed molecules

    International Nuclear Information System (INIS)

    Fink, R.F.; Pfister, J.; Schneider, A.; Zhao, H.; Engels, B.

    2008-01-01

    We present new, generally applicable protocols for the computation of the coupling parameter, J, of excitation energy transfer with quantum chemical ab initio methods. The protocols allow to select the degree of approximation and computational demand such that they are applicable for realistic systems and still allow to control the quality of the approach. We demonstrate the capabilities of the different protocols using the CO dimer as a first example. Correlation effects are found to scale J by a factor of about 0.7 which is in good agreement to earlier results obtained for the ethene dimer. The various levels of the protocol allow to assess the influence of ionic configurations and the polarisation within the dimer. Further, the interplay between the Foerster and Dexter contribution to J is investigated. The computations also show error compensation within approximations that are widely used for extended systems as in particular the transition density cube method

  20. Identifying stereoisomers by ab-initio calculation of secondary isotope shifts on NMR chemical shieldings.

    Science.gov (United States)

    Böhm, Karl-Heinz; Banert, Klaus; Auer, Alexander A

    2014-04-23

    We present ab-initio calculations of secondary isotope effects on NMR chemical shieldings. The change of the NMR chemical shift of a certain nucleus that is observed if another nucleus is replaced by a different isotope can be calculated by computing vibrational corrections on the NMR parameters using electronic structure methods. We demonstrate that the accuracy of the computational results is sufficient to even distinguish different conformers. For this purpose, benchmark calculations for fluoro(2-2H)ethane in gauche and antiperiplanar conformation are carried out at the HF, MP2 and CCSD(T) level of theory using basis sets ranging from double- to quadruple-zeta quality. The methodology is applied to the secondary isotope shifts for 2-fluoronorbornane in order to resolve an ambiguity in the literature on the assignment of endo- and exo-2-fluoronorbornanes with deuterium substituents in endo-3 and exo-3 positions, also yielding insight into mechanistic details of the corresponding synthesis.

  1. Identifying Stereoisomers by ab-initio Calculation of Secondary Isotope Shifts on NMR Chemical Shieldings

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Böhm

    2014-04-01

    Full Text Available We present ab-initio calculations of secondary isotope effects on NMR chemical shieldings. The change of the NMR chemical shift of a certain nucleus that is observed if another nucleus is replaced by a different isotope can be calculated by computing vibrational corrections on the NMR parameters using electronic structure methods. We demonstrate that the accuracy of the computational results is sufficient to even distinguish different conformers. For this purpose, benchmark calculations for fluoro(2-2Hethane in gauche and antiperiplanar conformation are carried out at the HF, MP2 and CCSD(T level of theory using basis sets ranging from double- to quadruple-zeta quality. The methodology is applied to the secondary isotope shifts for 2-fluoronorbornane in order to resolve an ambiguity in the literature on the assignment of endo- and exo-2-fluoronorbornanes with deuterium substituents in endo-3 and exo-3 positions, also yielding insight into mechanistic details of the corresponding synthesis.

  2. Ab initio configuration interaction description of excitation energy transfer between closely packed molecules

    Energy Technology Data Exchange (ETDEWEB)

    Fink, R.F. [University of Wuerzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Wuerzburg (Germany)], E-mail: reinhold.fink@rub.de; Pfister, J.; Schneider, A.; Zhao, H.; Engels, B. [University of Wuerzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Wuerzburg (Germany)

    2008-01-29

    We present new, generally applicable protocols for the computation of the coupling parameter, J, of excitation energy transfer with quantum chemical ab initio methods. The protocols allow to select the degree of approximation and computational demand such that they are applicable for realistic systems and still allow to control the quality of the approach. We demonstrate the capabilities of the different protocols using the CO dimer as a first example. Correlation effects are found to scale J by a factor of about 0.7 which is in good agreement to earlier results obtained for the ethene dimer. The various levels of the protocol allow to assess the influence of ionic configurations and the polarisation within the dimer. Further, the interplay between the Foerster and Dexter contribution to J is investigated. The computations also show error compensation within approximations that are widely used for extended systems as in particular the transition density cube method.

  3. The lod score method.

    Science.gov (United States)

    Rice, J P; Saccone, N L; Corbett, J

    2001-01-01

    The lod score method originated in a seminal article by Newton Morton in 1955. The method is broadly concerned with issues of power and the posterior probability of linkage, ensuring that a reported linkage has a high probability of being a true linkage. In addition, the method is sequential, so that pedigrees or lod curves may be combined from published reports to pool data for analysis. This approach has been remarkably successful for 50 years in identifying disease genes for Mendelian disorders. After discussing these issues, we consider the situation for complex disorders, where the maximum lod score (MLS) statistic shares some of the advantages of the traditional lod score approach but is limited by unknown power and the lack of sharing of the primary data needed to optimally combine analytic results. We may still learn from the lod score method as we explore new methods in molecular biology and genetic analysis to utilize the complete human DNA sequence and the cataloging of all human genes.

  4. The Bayesian Score Statistic

    NARCIS (Netherlands)

    Kleibergen, F.R.; Kleijn, R.; Paap, R.

    2000-01-01

    We propose a novel Bayesian test under a (noninformative) Jeffreys'priorspecification. We check whether the fixed scalar value of the so-calledBayesian Score Statistic (BSS) under the null hypothesis is aplausiblerealization from its known and standardized distribution under thealternative. Unlike

  5. South African Scoring System

    African Journals Online (AJOL)

    2014-11-18

    Nov 18, 2014 ... for 80% (SASS score) and 75% (NOT) of the variation in the regression model. Consequently, SASS ... further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics. Keywords: .... conductivity levels was assessed using multiple linear regres- sion.

  6. Developing Scoring Algorithms

    Science.gov (United States)

    We developed scoring procedures to convert screener responses to estimates of individual dietary intake for fruits and vegetables, dairy, added sugars, whole grains, fiber, and calcium using the What We Eat in America 24-hour dietary recall data from the 2003-2006 NHANES.

  7. Epidemiology of Functional abdominal bloating and its impact on health related quality of life: male-female stratified propensity score analysis in a population based survey in mainland China.

    Directory of Open Access Journals (Sweden)

    Meijing Wu

    Full Text Available BACKGROUND: The epidemiology of Functional abdominal bloating (FAB and its impact on health-related quality of life (HRQoL in Chinese people remains unclear. METHODS: Randomised, stratified, multi-stage sampling methodology was used to select a representative sample of the general population from five cities in China (n = 16,078. All respondents completed the modified Rome II questionnaire; 20% were asked to complete the 36-item Short Form (SF-36. The associated factors of FAB were analyzed. The effects of FAB on HRQoL were estimated with gender stratification using propensity score techniques in 20% subsample. RESULTS: Overall, 643 individuals (4.00% had FAB and it was more prevalent in males than in females (4.87% vs. 3.04%, P<0.001. For males, self-reported history of dyspepsia was most strongly associated with FAB (OR = 2.78; 95% CI: 1.59, 4.72. However, the most strongly associated factor was self-reported health status for females (moderate health vs. good health: OR = 2.06, 95% CI: 1.07, 3.96. P = 0.030; poor health vs. good health: OR = 5.71, 95% CI: 2.06, 15.09. Concerning HRQoL, FAB was found to be related to two domains: role limitation due to physical problems (P = 0.030 and bodily pain (P<0.001 in females. While, in males, there were significant differences in multiple domains between those with and without FAB. CONCLUSION: The prevalence of FAB in China was lower than previous reports. Males who had ever been diagnosed with dyspepsia and females who were in a poor self-reported health status were correlated with a higher prevalence of FAB. FAB affected only physical health in females, but impaired both physical and mental health in males.

  8. Computational methods for ab initio detection of microRNAs

    Directory of Open Access Journals (Sweden)

    Malik eYousef

    2012-10-01

    Full Text Available MicroRNAs are small RNA sequences of 18-24 nucleotides in length, which serve as templates to drive post transcriptional gene silencing. The canonical microRNA pathway starts with transcription from DNA and is followed by processing via the Microprocessor complex, yielding a hairpin structure. Which is then exported into the cytosol where it is processed by Dicer and then incorporated into the RNA induced silencing complex. All of these biogenesis steps add to the overall specificity of miRNA production and effect. Unfortunately, their modes of action are just beginning to be elucidated and therefore computational prediction algorithms cannot model the process but are usually forced to employ machine learning approaches. This work focuses on ab initio prediction methods throughout; and therefore homology-based miRNA detection methods are not discussed. Current ab initio prediction algorithms, their ties to data mining, and their prediction accuracy are detailed.

  9. Augmented wave ab initio EFG calculations: some methodological warnings

    International Nuclear Information System (INIS)

    Errico, Leonardo A.; Renteria, Mario; Petrilli, Helena M.

    2007-01-01

    We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO 2 . The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects

  10. Augmented wave ab initio EFG calculations: some methodological warnings

    Energy Technology Data Exchange (ETDEWEB)

    Errico, Leonardo A. [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Renteria, Mario [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Petrilli, Helena M. [Instituto de Fisica-DFMT, Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil)]. E-mail: hmpetril@macbeth.if.usp.br

    2007-02-01

    We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO{sub 2}. The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects.

  11. Ab Initio Calculations Of Light-Ion Reactions

    International Nuclear Information System (INIS)

    Navratil, P.; Quaglioni, S.; Roth, R.; Horiuchi, W.

    2012-01-01

    The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of nuclear forces, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present one of such promising techniques capable of describing simultaneously both bound and scattering states in light nuclei. By combining the resonating-group method (RGM) with the ab initio no-core shell model (NCSM), we complement a microscopic cluster approach with the use of realistic interactions and a microscopic and consistent description of the clusters. We discuss applications to light nuclei scattering, radiative capture and fusion reactions.

  12. GAUSSIAN 76: an ab initio molecular orbital program

    International Nuclear Information System (INIS)

    Binkley, J.S.; Whiteside, R.; Hariharan, P.C.; Seeger, R.; Hehre, W.J.; Lathan, W.A.; Newton, M.D.; Ditchfield, R.; Pople, J.A.

    Gaussian 76 is a general-purpose computer program for ab initio Hartree-Fock molecular orbital calculations. It can handle basis sets involving s, p and d-type gaussian functions. Certain standard sets (STO-3G, 4-31G, 6-31G*, etc.) are stored internally for easy use. Closed shell (RHF) or unrestricted open shell (UHF) wave functions can be obtained. Facilities are provided for geometry optimization to potential minima and for limited potential surface scans

  13. Ab initio study of hot electrons in GaAs

    OpenAIRE

    Bernardi, Marco; Vigil-Fowler, Derek; Ong, Chin Shen; Neaton, Jeffrey B.; Louie, Steven G.

    2015-01-01

    Hot carrier dynamics critically impacts the performance of electronic, optoelectronic, photovoltaic, and plasmonic devices. Hot carriers lose energy over nanometer lengths and picosecond timescales and thus are challenging to study experimentally, whereas calculations of hot carrier dynamics are cumbersome and dominated by empirical approaches. In this work, we present ab initio calculations of hot electrons in gallium arsenide (GaAs) using density functional theory and many-body perturbation...

  14. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Draayer, Jerry P. [Louisiana State Univ., Baton Rouge, LA (United States)

    2014-09-28

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  15. Ab initio nuclear structure - the large sparse matrix eigenvalue problem

    Energy Technology Data Exchange (ETDEWEB)

    Vary, James P; Maris, Pieter [Department of Physics, Iowa State University, Ames, IA, 50011 (United States); Ng, Esmond; Yang, Chao [Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sosonkina, Masha, E-mail: jvary@iastate.ed [Scalable Computing Laboratory, Ames Laboratory, Iowa State University, Ames, IA, 50011 (United States)

    2009-07-01

    The structure and reactions of light nuclei represent fundamental and formidable challenges for microscopic theory based on realistic strong interaction potentials. Several ab initio methods have now emerged that provide nearly exact solutions for some nuclear properties. The ab initio no core shell model (NCSM) and the no core full configuration (NCFC) method, frame this quantum many-particle problem as a large sparse matrix eigenvalue problem where one evaluates the Hamiltonian matrix in a basis space consisting of many-fermion Slater determinants and then solves for a set of the lowest eigenvalues and their associated eigenvectors. The resulting eigenvectors are employed to evaluate a set of experimental quantities to test the underlying potential. For fundamental problems of interest, the matrix dimension often exceeds 10{sup 10} and the number of nonzero matrix elements may saturate available storage on present-day leadership class facilities. We survey recent results and advances in solving this large sparse matrix eigenvalue problem. We also outline the challenges that lie ahead for achieving further breakthroughs in fundamental nuclear theory using these ab initio approaches.

  16. Ab initio nuclear structure - the large sparse matrix eigenvalue problem

    International Nuclear Information System (INIS)

    Vary, James P; Maris, Pieter; Ng, Esmond; Yang, Chao; Sosonkina, Masha

    2009-01-01

    The structure and reactions of light nuclei represent fundamental and formidable challenges for microscopic theory based on realistic strong interaction potentials. Several ab initio methods have now emerged that provide nearly exact solutions for some nuclear properties. The ab initio no core shell model (NCSM) and the no core full configuration (NCFC) method, frame this quantum many-particle problem as a large sparse matrix eigenvalue problem where one evaluates the Hamiltonian matrix in a basis space consisting of many-fermion Slater determinants and then solves for a set of the lowest eigenvalues and their associated eigenvectors. The resulting eigenvectors are employed to evaluate a set of experimental quantities to test the underlying potential. For fundamental problems of interest, the matrix dimension often exceeds 10 10 and the number of nonzero matrix elements may saturate available storage on present-day leadership class facilities. We survey recent results and advances in solving this large sparse matrix eigenvalue problem. We also outline the challenges that lie ahead for achieving further breakthroughs in fundamental nuclear theory using these ab initio approaches.

  17. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    International Nuclear Information System (INIS)

    Draayer, Jerry P.

    2014-01-01

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  18. Ab Initio Calculations of Transport in Titanium and Aluminum Mixtures

    Science.gov (United States)

    Walker, Nicholas; Novak, Brian; Tam, Ka Ming; Moldovan, Dorel; Jarrell, Mark

    In classical molecular dynamics simulations, the self-diffusion and shear viscosity of titanium about the melting point have fallen within the ranges provided by experimental data. However, the experimental data is difficult to collect and has been rather scattered, making it of limited value for the validation of these calculations. By using ab initio molecular dynamics simulations within the density functional theory framework, the classical molecular dynamics data can be validated. The dynamical data from the ab initio molecular dynamics can also be used to calculate new potentials for use in classical molecular dynamics, allowing for more accurate classical dynamics simulations for the liquid phase. For metallic materials such as titanium and aluminum alloys, these calculations are very valuable due to an increasing demand for the knowledge of their thermophysical properties that drive the development of new materials. For example, alongside knowledge of the surface tension, viscosity is an important input for modeling the additive manufacturing process at the continuum level. We are developing calculations of the viscosity along with the self-diffusion for aluminum, titanium, and titanium-aluminum alloys with ab initio molecular dynamics. Supported by the National Science Foundation through cooperative agreement OIA-1541079 and the Louisiana Board of Regents.

  19. Ab initio multiple cloning algorithm for quantum nonadiabatic molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Makhov, Dmitry V.; Shalashilin, Dmitrii V. [Department of Chemistry, University of Leeds, Leeds LS2 9JT (United Kingdom); Glover, William J.; Martinez, Todd J. [Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, USA and SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States)

    2014-08-07

    We present a new algorithm for ab initio quantum nonadiabatic molecular dynamics that combines the best features of ab initio Multiple Spawning (AIMS) and Multiconfigurational Ehrenfest (MCE) methods. In this new method, ab initio multiple cloning (AIMC), the individual trajectory basis functions (TBFs) follow Ehrenfest equations of motion (as in MCE). However, the basis set is expanded (as in AIMS) when these TBFs become sufficiently mixed, preventing prolonged evolution on an averaged potential energy surface. We refer to the expansion of the basis set as “cloning,” in analogy to the “spawning” procedure in AIMS. This synthesis of AIMS and MCE allows us to leverage the benefits of mean-field evolution during periods of strong nonadiabatic coupling while simultaneously avoiding mean-field artifacts in Ehrenfest dynamics. We explore the use of time-displaced basis sets, “trains,” as a means of expanding the basis set for little cost. We also introduce a new bra-ket averaged Taylor expansion (BAT) to approximate the necessary potential energy and nonadiabatic coupling matrix elements. The BAT approximation avoids the necessity of computing electronic structure information at intermediate points between TBFs, as is usually done in saddle-point approximations used in AIMS. The efficiency of AIMC is demonstrated on the nonradiative decay of the first excited state of ethylene. The AIMC method has been implemented within the AIMS-MOLPRO package, which was extended to include Ehrenfest basis functions.

  20. Credit scoring methods

    Czech Academy of Sciences Publication Activity Database

    Vojtek, Martin; Kočenda, Evžen

    2006-01-01

    Roč. 56, 3-4 (2006), s. 152-167 ISSN 0015-1920 R&D Projects: GA ČR GA402/05/0931 Institutional research plan: CEZ:AV0Z70850503 Keywords : banking sector * credit scoring * discrimination analysis Subject RIV: AH - Economics Impact factor: 0.190, year: 2006 http://journal.fsv.cuni.cz/storage/1050_s_152_167.pdf

  1. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1999-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  2. Towards hydrogen metallization: an Ab initio approach; Vers la metallisation de l`hydrogene: approche AB initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, St

    1998-12-31

    The quest for metallic hydrogen is a major goal for both theoretical and experimental condensed matter physics. Hydrogen and deuterium have been compressed up to 200 GPa in diamond anvil cells, without any clear evidence for a metallic behaviour. Loubeyere has recently suggested that hydrogen could metallize, at pressures within experimental range, in a new Van der Waals compound: Ar(H{sub 2}){sub 2} which is characterized at ambient pressure by an open and anisotropic sublattice of hydrogen molecules, stabilized by an argon skeleton. This thesis deals with a detailed ab initio investigation, by Car-Parrinello molecular dynamics methods, of the evolution under pressure of this compound. In a last chapter, we go to much higher pressures and temperatures, in order to compare orbital and orbital free ab initio methods for the dense hydrogen plasma. (author) 109 refs.

  3. Credit scoring for individuals

    Directory of Open Access Journals (Sweden)

    Maria DIMITRIU

    2010-12-01

    Full Text Available Lending money to different borrowers is profitable, but risky. The profits come from the interest rate and the fees earned on the loans. Banks do not want to make loans to borrowers who cannot repay them. Even if the banks do not intend to make bad loans, over time, some of them can become bad. For instance, as a result of the recent financial crisis, the capability of many borrowers to repay their loans were affected, many of them being on default. That’s why is important for the bank to monitor the loans. The purpose of this paper is to focus on credit scoring main issues. As a consequence of this, we presented in this paper the scoring model of an important Romanian Bank. Based on this credit scoring model and taking into account the last lending requirements of the National Bank of Romania, we developed an assessment tool, in Excel, for retail loans which is presented in the case study.

  4. College Math Assessment: SAT Scores vs. College Math Placement Scores

    Science.gov (United States)

    Foley-Peres, Kathleen; Poirier, Dawn

    2008-01-01

    Many colleges and university's use SAT math scores or math placement tests to place students in the appropriate math course. This study compares the use of math placement scores and SAT scores for 188 freshman students. The student's grades and faculty observations were analyzed to determine if the SAT scores and/or college math assessment scores…

  5. Prepartum concentrate supplementation of a diet based on medium-quality grass silage: Effects on performance, health, fertility, metabolic function, and immune function of low body condition score cows.

    Science.gov (United States)

    Little, M W; O'Connell, N E; Welsh, M D; Barley, J; Meade, K G; Ferris, C P

    2016-09-01

    When cows with a "higher" body condition score (BCS) are oversupplied with energy during the dry period, postpartum energy balance is normally reduced, which can have a detrimental effect on immune competence and increase the infectious disease risk. However, within grassland-based systems higher yielding cows frequently have a low BCS at drying off. The effects on performance, health, and metabolic and immune functions of providing additional energy to cows with low BCS during the dry period is less certain. To address this uncertainty, 53 multiparous Holstein-Friesian cows (mean BCS of 2.5; 1-5 scale) were allocated to 1 of 2 treatments at dry-off: silage only or silage plus concentrates. Cows on the silage-only treatment were offered ad libitum access to medium-quality grass silage. Cows on the silage-plus-concentrate treatment were offered ad libitum access to a mixed ration comprising the same grass silage plus concentrates [in a 75:25 dry matter (DM) ratio], which provided a mean concentrate DM intake of 3.0kg/cow per day. Postpartum, cows were offered a common mixed ration comprising grass silage and concentrates (in a 40:60 DM ratio) for a 70-d period. Offering concentrates during the dry period increased DM intake, tended to increase energy balance, and increased body weight (BW) and BCS gain prepartum. Offering concentrates during the dry period increased BW and BCS loss postpartum and tended to increase milk fat percentage and serum nonesterified fatty acid concentration, but it did not affect postpartum DM intake, energy balance, and milk yield. Although the percentage of phagocytosis-positive neutrophils did not differ, neutrophils from cows on the silage-plus-concentrate treatment had higher phagocytic fluorescence intensity at 1 and 2 wk postpartum and higher phagocytic index at 1 wk postpartum. Serum haptoglobin concentrations and IFN-γ production by pokeweed mitogen stimulated whole blood culture were unaffected by treatment, although haptoglobin

  6. Estimating NHL Scoring Rates

    OpenAIRE

    Buttrey, Samuel E.; Washburn, Alan R.; Price, Wilson L.; Operations Research

    2011-01-01

    The article of record as published may be located at http://dx.doi.org/10.2202/1559-0410.1334 We propose a model to estimate the rates at which NHL teams score and yield goals. In the model, goals occur as if from a Poisson process whose rate depends on the two teams playing, the home-ice advantage, and the manpower (power-play, short-handed) situation. Data on all the games from the 2008-2009 season was downloaded and processed into a form suitable for the analysis. The model...

  7. The International Bleeding Risk Score

    DEFF Research Database (Denmark)

    Laursen, Stig Borbjerg; Laine, L.; Dalton, H.

    2017-01-01

    The International Bleeding Risk Score: A New Risk Score that can Accurately Predict Mortality in Patients with Upper GI-Bleeding.......The International Bleeding Risk Score: A New Risk Score that can Accurately Predict Mortality in Patients with Upper GI-Bleeding....

  8. Ab Initio Studies of Metal Hexaboride Materials

    Science.gov (United States)

    Schmidt, Kevin M.

    Metal hexaborides are refractory ceramics with several qualities relevant to materials design, such as low work functions, high hardness, low thermal expansion coefficients, and high melting points, among many other properties of interest for industrial applications. Thermal and mechanical stability is a common feature provided by the covalently-bonded network boron atoms, and electronic properties can vary significantly with the resident metal. While these materials are currently employed as electron emitters and abrasives, promising uses of these materials also include catalytic applications for chemical dissociation reactions of various molecules such as hydrogen, water and carbon monoxide, for example. However, these extensions require a thorough understanding of particular mechanical and electronic properties. This dissertation is a collection of studies focused on understanding the behavior of metal hexaboride materials using computational modeling methods to investigate materials properties of these from both classical and quantum mechanical points of view. Classical modeling is performed using molecular dynamics methods with interatomic potentials obtained from density functional theory (DFT) calculations. Atomic mean-square displacements from the quasi-harmonic approximation and lattice energetic data are produced with DFT for developing the potentials. A generalized method was also developed for the inversion of cohesive energy curves of crystalline materials; pairwise interatomic potentials are extracted using detailed geometrical descriptions of the atomic interactions and a list of atomic displacements and degeneracies. The surface structure of metal hexaborides is studied with DFT using several model geometries to describe the terminal cation layouts, and these provide a basis for further studies on metal hexaboride interactions with hydrogen. The surface electronic structure calculations show that segregated regions of metal and boron

  9. The Pariser-Parr-Pople model for trans-polyenes. I. Ab initio and semiempirical study of the bond alternation in trans-butadiene

    Science.gov (United States)

    Förner, Wolfgang

    1992-03-01

    Ab initio investigations of the bond alternation in butadiene are presented. The atomic basis sets applied range from minimal to split valence plus polarization quality. With the latter one the Hartree-Fock limit for the bond alternation is reached. Correlation is considered on Møller-Plesset many-body perturbation theory of second order (MP2), linear coupled cluster doubles (L-CCD) and coupled cluster doubles (CCD) level. For the smaller basis sets it is shown that for the bond alternation π-π correlations are essential while the effects of σ-σ and σ-π correlations are, though large, nearly independent of bond alternation. On MP2 level the variation of σ-π correlation with bond alternation is surprisingly large. This is discussed as an artefact of MP2. Comparative Su-Schrieffer-Heeger (SSH) and Pariser-Parr-Pople (PPP) calculations show that these models in their usual parametrizations cannot reproduce the ab initio results.

  10. State-of-the-art ab initio potential energy curve for the xenon atom pair and related spectroscopic and thermophysical properties

    Science.gov (United States)

    Hellmann, Robert; Jäger, Benjamin; Bich, Eckard

    2017-07-01

    A new ab initio interatomic potential energy curve for two ground-state xenon atoms is presented. It is based on supermolecular calculations at the coupled-cluster level with single, double, and perturbative triple excitations [CCSD(T)] employing basis sets up to sextuple-zeta quality, which were developed as part of this work. In addition, corrections were determined for higher coupled-cluster levels up to CCSDTQ as well as for scalar and spin-orbit relativistic effects at the CCSD(T) level. A physically motivated analytical function was fitted to the calculated interaction energies and used to compute the vibrational spectrum of the dimer, the second virial coefficient, and the dilute gas transport properties. The agreement with the best available experimental data for the investigated properties is excellent; the new potential function is superior not only to previous ab initio potentials but also to the most popular empirical ones.

  11. State-of-the-art ab initio potential energy curve for the xenon atom pair and related spectroscopic and thermophysical properties.

    Science.gov (United States)

    Hellmann, Robert; Jäger, Benjamin; Bich, Eckard

    2017-07-21

    A new ab initio interatomic potential energy curve for two ground-state xenon atoms is presented. It is based on supermolecular calculations at the coupled-cluster level with single, double, and perturbative triple excitations [CCSD(T)] employing basis sets up to sextuple-zeta quality, which were developed as part of this work. In addition, corrections were determined for higher coupled-cluster levels up to CCSDTQ as well as for scalar and spin-orbit relativistic effects at the CCSD(T) level. A physically motivated analytical function was fitted to the calculated interaction energies and used to compute the vibrational spectrum of the dimer, the second virial coefficient, and the dilute gas transport properties. The agreement with the best available experimental data for the investigated properties is excellent; the new potential function is superior not only to previous ab initio potentials but also to the most popular empirical ones.

  12. Cooperative effects in spherical spasers: Ab initio analytical model

    Science.gov (United States)

    Bordo, V. G.

    2017-06-01

    A fully analytical semiclassical theory of cooperative optical processes which occur in an ensemble of molecules embedded in a spherical core-shell nanoparticle is developed from first principles. Both the plasmonic Dicke effect and spaser generation are investigated for the designs in which a shell/core contains an arbitrarily large number of active molecules in the vicinity of a metallic core/shell. An essential aspect of the theory is an ab initio account of the feedback from the core/shell boundaries which significantly modifies the molecular dynamics. The theory provides rigorous, albeit simple and physically transparent, criteria for both plasmonic superradiance and surface plasmon generation.

  13. Tailoring magnetoresistance at the atomic level: An ab initio study

    KAUST Repository

    Tao, Kun

    2012-01-05

    The possibility of manipulating the tunneling magnetoresistance (TMR) of antiferromagnetic nanostructures is predicted in the framework of ab initio calculations. By the example of a junction composed of an antiferromagnetic dimer and a spin-polarized scanning tunneling microscopy tip we show that the TMR can be tuned and even reversed in sign by lateral and vertical movements of the tip. Moreover, our finite-bias calculations demonstrate that the magnitude and the sign of the TMR can also be tuned by an external voltage. © 2012 American Physical Society.

  14. Tailoring magnetoresistance at the atomic level: An ab initio study

    KAUST Repository

    Tao, Kun; Stepanyuk, V. S.; Rungger, I.; Sanvito, S.

    2012-01-01

    The possibility of manipulating the tunneling magnetoresistance (TMR) of antiferromagnetic nanostructures is predicted in the framework of ab initio calculations. By the example of a junction composed of an antiferromagnetic dimer and a spin-polarized scanning tunneling microscopy tip we show that the TMR can be tuned and even reversed in sign by lateral and vertical movements of the tip. Moreover, our finite-bias calculations demonstrate that the magnitude and the sign of the TMR can also be tuned by an external voltage. © 2012 American Physical Society.

  15. Ab initio calculations on hydrogen storage in porous carbons

    International Nuclear Information System (INIS)

    Maresca, O.; Marinelli, F.; Pellenq, R.J.M.; Duclaux, L.; Azais, Ph.; Conard, J.

    2005-01-01

    We have investigated through ab initio computations the possible ways to achieve efficient hydrogen storage on carbons. Firstly, we have considered how the curvature of a carbon surface could affect the chemisorption of atomic H 0 Secondly, we show that electron donor elements such as Li and K, used as dopants for the carbon substrate, strongly enhance the physi-sorption energy of H 2 , allowing in principle its storage in this type of material at room temperature under mild conditions of pressure. (authors)

  16. Routine calculation of ab initio melting curves: application to aluminum

    OpenAIRE

    Robert, Grégory; Legrand, Philippe; Arnault, Philippe; Desbiens, Nicolas; Clérouin, Jean

    2014-01-01

    We present a simple, fast, and reliable method to compute the melting curves of materials with ab initio molecular dynamics. It is based on the two-phase thermodynamic model of [Lin et al., J. Chem. Phys. 119, 11792 (2003)] and its improved version given by [Desjarlais, Phys. Rev. E, 88, 062145 (2013)]. In this model, the velocity autocorrelation function is utilized to calculate the contribution of the nuclei motion to the entropy of the solid and liquid phases. It is then possible to find t...

  17. TiAl doping by vanadium: ab initio study

    International Nuclear Information System (INIS)

    Smirnova, E.A.; Isaev, Eh.I.; Vekilov, Yu.Kh.

    2004-01-01

    Tetragonality degree in TiAl and vanadium doping effect on it were studied using the methods of calculation based on approximation of coherent potential and ab initio pseudopotentials. It is shown that vanadium substitution for Ti sublattice atoms entails increase in tetragonality degree but with substitution of the atoms in aluminium sublattice the tetragonality of the TiAl:V alloy decreases and at the content of vanadium about 8 at. % the lattice becomes actually cubical. In its turn, it may result in increase in TiAl ductility, the alloy being brittle at low temperatures [ru

  18. Ab initio calculation of tensile strength in iron

    Czech Academy of Sciences Publication Activity Database

    Friák, Martin; Šob, Mojmír; Vitek, V.

    2003-01-01

    Roč. 83, 31-34 (2003), s. 3529-3537 ISSN 1478-6435. [Multiscale Materials Modelling: Working Theory for Industry /1./. London, 17.06.2002-20.06.2002] R&D Projects: GA AV ČR IAA1041302; GA ČR GA202/03/1351; GA MŠk OC 523.90 Institutional research plan: CEZ:AV0Z2041904 Keywords : ab initio calculations * electronic structure * theoretical tensile strength Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. Ab initio molecular dynamics in a finite homogeneous electric field.

    Science.gov (United States)

    Umari, P; Pasquarello, Alfredo

    2002-10-07

    We treat homogeneous electric fields within density functional calculations with periodic boundary conditions. A nonlocal energy functional depending on the applied field is used within an ab initio molecular dynamics scheme. The reliability of the method is demonstrated in the case of bulk MgO for the Born effective charges, and the high- and low-frequency dielectric constants. We evaluate the static dielectric constant by performing a damped molecular dynamics in an electric field and avoiding the calculation of the dynamical matrix. Application of this method to vitreous silica shows good agreement with experiment and illustrates its potential for systems of large size.

  20. Ab initio and Gordon--Kim intermolecular potentials for two nitrogen molecules

    International Nuclear Information System (INIS)

    Ree, F.H.; Winter, N.W.

    1980-01-01

    Both ab initio MO--LCAO--SCF and the electron-gas (or Gordon--Kim) methods have been used to compute the intermolecular potential (Phi) of N 2 molecules for seven different N 2 --N 2 orientations. The ab initio calculations were carried out using a [4s3p] contracted Gaussian basis set with and without 3d polarization functions. The larger basis set provides adequate results for Phi>0.002 hartree or intermolecular separations less than 6.5--7 bohr. We use a convenient analytic expression to represent the ab initio data in terms of the intermolecular distance and three angles defining the orientations of the two N 2 molecules. The Gordon--Kim method with Rae's self-exchange correction yields Phi, which agrees reasonably well over a large repulsive range. However, a detailed comparison of the electron kinetic energy contributions shows a large difference between the ab initio and the Gordon--Kim calculations. Using the ab initio data we derive an atom--atom potential of the two N 2 molecules. Although this expression does not accurately fit the data at some orientations, its spherical average agrees with the corresponding average of the ab initio Phi remarkably well. The spherically averaged ab initio Phi is also compared with the corresponding quantities derived from experimental considerations. The approach of the ab initio Phi to the classical quadrupole--quadrupole interaction at large intermolecular separation is also discussed

  1. Modeling Disordered Materials with a High Throughput ab-initio Approach

    Science.gov (United States)

    2015-11-13

    Modeling Disordered Materials with a High Throughput ab - initio Approach Kesong Yang,1 Corey Oses,2 and Stefano Curtarolo3, 4 1Department of...J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169–11186 (1996

  2. Embedded atom approach for gold–silicon system from ab initio

    Indian Academy of Sciences (India)

    In the present paper, an empirical embedded atom method (EAM) potential for gold–silicon (Au–Si) is developed by fitting to ab initio force (the 'force matching' method) and experimental data. The force database is generated within ab initio molecular dynamics (AIMD). The database includes liquid phase at various ...

  3. QUASAR--scoring and ranking of sequence-structure alignments.

    Science.gov (United States)

    Birzele, Fabian; Gewehr, Jan E; Zimmer, Ralf

    2005-12-15

    Sequence-structure alignments are a common means for protein structure prediction in the fields of fold recognition and homology modeling, and there is a broad variety of programs that provide such alignments based on sequence similarity, secondary structure or contact potentials. Nevertheless, finding the best sequence-structure alignment in a pool of alignments remains a difficult problem. QUASAR (quality of sequence-structure alignments ranking) provides a unifying framework for scoring sequence-structure alignments that aids finding well-performing combinations of well-known and custom-made scoring schemes. Those scoring functions can be benchmarked against widely accepted quality scores like MaxSub, TMScore, Touch and APDB, thus enabling users to test their own alignment scores against 'standard-of-truth' structure-based scores. Furthermore, individual score combinations can be optimized with respect to benchmark sets based on known structural relationships using QUASAR's in-built optimization routines.

  4. Summation of Parquet diagrams as an ab initio method in nuclear structure calculations

    International Nuclear Information System (INIS)

    Bergli, Elise; Hjorth-Jensen, Morten

    2011-01-01

    Research highlights: → We present a Green's function based approach for doing ab initio nuclear structure calculations. → In particular the sum the subset of so-called Parquet diagrams. → Applying the theory to a simple but realistic model, results in good agreement with other ab initio methods. → This opens up for ab initio calculations for medium-heavy nuclei. - Abstract: In this work we discuss the summation of the Parquet class of diagrams within Green's function theory as a possible framework for ab initio nuclear structure calculations. The theory is presented and some numerical details are discussed, in particular the approximations employed. We apply the Parquet method to a simple model, and compare our results with those from an exact solution. The main conclusion is that even at the level of approximation presented here, the results shows good agreement with other comparable ab initio approaches.

  5. Residue contacts predicted by evolutionary covariance extend the application of ab initio molecular replacement to larger and more challenging protein folds

    Directory of Open Access Journals (Sweden)

    Felix Simkovic

    2016-07-01

    Full Text Available For many protein families, the deluge of new sequence information together with new statistical protocols now allow the accurate prediction of contacting residues from sequence information alone. This offers the possibility of more accurate ab initio (non-homology-based structure prediction. Such models can be used in structure solution by molecular replacement (MR where the target fold is novel or is only distantly related to known structures. Here, AMPLE, an MR pipeline that assembles search-model ensembles from ab initio structure predictions (`decoys', is employed to assess the value of contact-assisted ab initio models to the crystallographer. It is demonstrated that evolutionary covariance-derived residue–residue contact predictions improve the quality of ab initio models and, consequently, the success rate of MR using search models derived from them. For targets containing β-structure, decoy quality and MR performance were further improved by the use of a β-strand contact-filtering protocol. Such contact-guided decoys achieved 14 structure solutions from 21 attempted protein targets, compared with nine for simple Rosetta decoys. Previously encountered limitations were superseded in two key respects. Firstly, much larger targets of up to 221 residues in length were solved, which is far larger than the previously benchmarked threshold of 120 residues. Secondly, contact-guided decoys significantly improved success with β-sheet-rich proteins. Overall, the improved performance of contact-guided decoys suggests that MR is now applicable to a significantly wider range of protein targets than were previously tractable, and points to a direct benefit to structural biology from the recent remarkable advances in sequencing.

  6. Equations of state of heavy metals: ab initio approaches; Equations d'etat des metaux lourds: approches ab initio

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, S.; Jollet, F.; Jomard, G.; Siberchicot, B.; Torrent, M.; Zerah, G.; Amadon, B.; Bouchet, J.; Richard, N.; Robert, G. [CEA Bruyeres-le-Chatel, 91 (France)

    2005-07-01

    The determination of equations of states of heavy metals through ab initio calculation, i.e. without any adjustable parameter, allows to access to pressure and temperature thermodynamic conditions sometimes inaccessible to experiment. To perform such calculations, density functional theory (DFT) is a good starting point: when electronic densities are homogeneous enough, the local density approximation (LDA) remarkably accounts for thermodynamic properties of heavy metals, such as tantalum, or the light actinides, as well for static properties - equilibrium volume, elastic constants - as for dynamical quantities like phonon spectra. For heavier elements, like neptunium or plutonium, relativistic effects and strong electronic interactions must be taken into account, which requires more sophisticated theoretical approaches. (authors)

  7. Using Trauma and Injury Severity Score (TRISS)-based analysis in the development of regional risk adjustment tools to trend quality in a voluntary trauma system: the experience of the Trauma Foundation of Northeast Ohio.

    Science.gov (United States)

    Mancuso, C; Barnoski, A; Tinnell, C; Fallon, W

    2000-04-01

    Presently, no trauma system exists in Ohio. Since 1993, all hospitals in Cuyahoga County (CUY), northeast Ohio (n = 22) provide data to a trauma registry. In return, each received hospital-specific data, comparison data by trauma care level and a county-wide aggregate summary. This report describes the results of this approach in our region. All cases were entered by paper abstract or electronic download. Interrater reliability audits and z score analysis was performed by using the Major Trauma Outcome Study and the CUY 1994 baseline groups. Risk adjustment of mortality data was performed using statistical modeling and logistic regression (Trauma and Injury Severity Score, Major Trauma Outcome Study, CUY). Trauma severity measures were defined. In 1995, 3,375 patients were entered. Two hundred ninety-one died (8.6%). Severity measures differed by level of trauma care, indicating differences in case mix. Probability of survival was lowest in the Level I centers, highest in the acute care hospitals. Outcomes z scores demonstrated survival differences for all levels. In a functioning trauma system, the most severely injured patients should be cared for at the trauma centers. A low volume at acute care hospitals is desirable. By using Trauma and Injury Severity Score with community-specific constants, NE Ohio is accomplishing these goals. The Level I performance data are an interesting finding compared with the data from the Level II centers in the region

  8. Ab initio theory and calculations of X-ray spectra

    International Nuclear Information System (INIS)

    Rehr, J.J.; Kas, J.J.; Prange, M.P.; Sorini, A.P.; Takimoto, Y.; Vila, F.

    2009-01-01

    There has been dramatic progress in recent years both in the calculation and interpretation of various x-ray spectroscopies. However, current theoretical calculations often use a number of simplified models to account for many-body effects, in lieu of first principles calculations. In an effort to overcome these limitations we describe in this article a number of recent advances in theory and in theoretical codes which offer the prospect of parameter free calculations that include the dominant many-body effects. These advances are based on ab initio calculations of the dielectric and vibrational response of a system. Calculations of the dielectric function over a broad spectrum yield system dependent self-energies and mean-free paths, as well as intrinsic losses due to multielectron excitations. Calculations of the dynamical matrix yield vibrational damping in terms of multiple-scattering Debye-Waller factors. Our ab initio methods for determining these many-body effects have led to new, improved, and broadly applicable x-ray and electron spectroscopy codes. (authors)

  9. (4)He Thermophysical Properties: New Ab Initio Calculations.

    Science.gov (United States)

    Hurly, John J; Mehl, James B

    2007-01-01

    Since 2000, atomic physicists have reduced the uncertainty of the helium-helium "ab initio" potential; for example, from approximately 0.6 % to 0.1 % at 4 bohr, and from 0.8 % to 0.1 % at 5.6 bohr. These results led us to: (1) construct a new inter-atomic potential ϕ 07, (2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of (4)He from 1 K to 10,000 K, and (3), analyze the uncertainties of the thermophysical properties that propagate from the uncertainty of ϕ 07 and from the Born-Oppenheimer approximation of the electron-nucleon quantum mechanical system. We correct minor errors in a previous publication [J. J. Hurly and M. R. Moldover, J. Res. Nat. Inst. Standards Technol. 105, 667 (2000)] and compare our results with selected data published after 2000. The ab initio results tabulated here can serve as standards for the measurement of thermophysical properties.

  10. Ab initio thermodynamic model for magnesium carbonates and hydrates.

    Science.gov (United States)

    Chaka, Anne M; Felmy, Andrew R

    2014-09-04

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first-principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogues of Ca-based hydrated carbonates monohydrocalcite and ikaite, which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  11. A Deep Learning Network Approach to ab initio Protein Secondary Structure Prediction.

    Science.gov (United States)

    Spencer, Matt; Eickholt, Jesse; Jianlin Cheng

    2015-01-01

    Ab initio protein secondary structure (SS) predictions are utilized to generate tertiary structure predictions, which are increasingly demanded due to the rapid discovery of proteins. Although recent developments have slightly exceeded previous methods of SS prediction, accuracy has stagnated around 80 percent and many wonder if prediction cannot be advanced beyond this ceiling. Disciplines that have traditionally employed neural networks are experimenting with novel deep learning techniques in attempts to stimulate progress. Since neural networks have historically played an important role in SS prediction, we wanted to determine whether deep learning could contribute to the advancement of this field as well. We developed an SS predictor that makes use of the position-specific scoring matrix generated by PSI-BLAST and deep learning network architectures, which we call DNSS. Graphical processing units and CUDA software optimize the deep network architecture and efficiently train the deep networks. Optimal parameters for the training process were determined, and a workflow comprising three separately trained deep networks was constructed in order to make refined predictions. This deep learning network approach was used to predict SS for a fully independent test dataset of 198 proteins, achieving a Q3 accuracy of 80.7 percent and a Sov accuracy of 74.2 percent.

  12. Methods and statistics for combining motif match scores.

    Science.gov (United States)

    Bailey, T L; Gribskov, M

    1998-01-01

    Position-specific scoring matrices are useful for representing and searching for protein sequence motifs. A sequence family can often be described by a group of one or more motifs, and an effective search must combine the scores for matching a sequence to each of the motifs in the group. We describe three methods for combining match scores and estimating the statistical significance of the combined scores and evaluate the search quality (classification accuracy) and the accuracy of the estimate of statistical significance of each. The three methods are: 1) sum of scores, 2) sum of reduced variates, 3) product of score p-values. We show that method 3) is superior to the other two methods in both regards, and that combining motif scores indeed gives better search accuracy. The MAST sequence homology search algorithm utilizing the product of p-values scoring method is available for interactive use and downloading at URL http:/(/)www.sdsc.edu/MEME.

  13. Room temperature linelists for CO2 asymmetric isotopologues with ab initio computed intensities

    Science.gov (United States)

    Zak, Emil J.; Tennyson, Jonathan; Polyansky, Oleg L.; Lodi, Lorenzo; Zobov, Nikolay F.; Tashkun, Sergei A.; Perevalov, Valery I.

    2017-12-01

    The present paper reports room temperature line lists for six asymmetric isotopologues of carbon dioxide: 16O12C18O (628), 16O12C17O (627), 16O13C18O (638),16O13C17O (637), 17O12C18O (728) and 17O13C18O (738), covering the range 0-8000 cm-1. Variational rotation-vibration wavefunctions and energy levels are computed using the DVR3D software suite and a high quality semi-empirical potential energy surface (PES), followed by computation of intensities using an ab initio dipole moment surface (DMS). A theoretical procedure for quantifying sensitivity of line intensities to minor distortions of the PES/DMS renders our theoretical model as critically evaluated. Several recent high quality measurements and theoretical approaches are discussed to provide a benchmark of our results against the most accurate available data. Indeed, the thesis of transferability of accuracy among different isotopologues with the use of mass-independent PES is supported by several examples. Thereby, we conclude that the majority of line intensities for strong bands are predicted with sub-percent accuracy. Accurate line positions are generated using an effective Hamiltonian, constructed from the latest experiments. This study completes the list of relevant isotopologues of carbon dioxide; these line lists are available to remote sensing studies and inclusion in databases.

  14. Do Test Scores Buy Happiness?

    Science.gov (United States)

    McCluskey, Neal

    2017-01-01

    Since at least the enactment of No Child Left Behind in 2002, standardized test scores have served as the primary measures of public school effectiveness. Yet, such scores fail to measure the ultimate goal of education: maximizing happiness. This exploratory analysis assesses nation level associations between test scores and happiness, controlling…

  15. Airline Quality Rating 2001

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2001-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, Airline Quality Rating 2001, reflects monthly Airline Quality Rating scores for 2000. AQR scores for the calendar year 2000 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2001 is a summary of month-by-month quality ra...

  16. Influence of the ab initio n–d cross sections in the critical heavy-water benchmarks

    International Nuclear Information System (INIS)

    Morillon, B.; Lazauskas, R.; Carbonell, J.

    2013-01-01

    Highlights: ► We solve the three nucleon problem using different NN potential (MT, AV18 and INOY) to calculate the Neutron–deuteron cross sections. ► These cross sections are compared to the existing experimental data and to international libraries. ► We describe the different sets of heavy water benchmarks for which the Monte Carlo simulations have been performed including our new Neutron–deuteron cross sections. ► The results obtained by the ab initio INOY potential have been compared with the calculations based on the international library cross sections and are found to be of the same quality. - Abstract: The n–d elastic and breakup cross sections are computed by solving the three-body Faddeev equations for realistic and semi-realistic nucleon–nucleon potentials. These cross sections are inserted in the Monte Carlo simulation of the nuclear processes considered in the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook). The results obtained using thes ab initio n–d cross sections are compared with those provided by the most renown international libraries

  17. Predicting occupational personality test scores.

    Science.gov (United States)

    Furnham, A; Drakeley, R

    2000-01-01

    The relationship between students' actual test scores and their self-estimated scores on the Hogan Personality Inventory (HPI; R. Hogan & J. Hogan, 1992), an omnibus personality questionnaire, was examined. Despite being given descriptive statistics and explanations of each of the dimensions measured, the students tended to overestimate their scores; yet all correlations between actual and estimated scores were positive and significant. Correlations between self-estimates and actual test scores were highest for sociability, ambition, and adjustment (r = .62 to r = .67). The results are discussed in terms of employers' use and abuse of personality assessment for job recruitment.

  18. Fingerprint Recognition Using Minutia Score Matching

    OpenAIRE

    J, Ravi.; Raja, K. B.; R, Venugopal. K.

    2010-01-01

    The popular Biometric used to authenticate a person is Fingerprint which is unique and permanent throughout a person’s life. A minutia matching is widely used for fingerprint recognition and can be classified as ridge ending and ridge bifurcation. In this paper we projected Fingerprint Recognition using Minutia Score Matching method (FRMSM). For Fingerprint thinning, the Block Filter is used, which scans the image at the boundary to preserves the quality of the image and extract the minutiae ...

  19. MODELING CREDIT RISK THROUGH CREDIT SCORING

    OpenAIRE

    Adrian Cantemir CALIN; Oana Cristina POPOVICI

    2014-01-01

    Credit risk governs all financial transactions and it is defined as the risk of suffering a loss due to certain shifts in the credit quality of a counterpart. Credit risk literature gravitates around two main modeling approaches: the structural approach and the reduced form approach. In addition to these perspectives, credit risk assessment has been conducted through a series of techniques such as credit scoring models, which form the traditional approach. This paper examines the evolution of...

  20. Differences of wells scores accuracy, caprini scores and padua scores in deep vein thrombosis diagnosis

    Science.gov (United States)

    Gatot, D.; Mardia, A. I.

    2018-03-01

    Deep Vein Thrombosis (DVT) is the venous thrombus in lower limbs. Diagnosis is by using venography or ultrasound compression. However, these examinations are not available yet in some health facilities. Therefore many scoring systems are developed for the diagnosis of DVT. The scoring method is practical and safe to use in addition to efficacy, and effectiveness in terms of treatment and costs. The existing scoring systems are wells, caprini and padua score. There have been many studies comparing the accuracy of this score but not in Medan. Therefore, we are interested in comparative research of wells, capriniand padua score in Medan.An observational, analytical, case-control study was conducted to perform diagnostic tests on the wells, caprini and padua score to predict the risk of DVT. The study was at H. Adam Malik Hospital in Medan.From a total of 72 subjects, 39 people (54.2%) are men and the mean age are 53.14 years. Wells score, caprini score and padua score has a sensitivity of 80.6%; 61.1%, 50% respectively; specificity of 80.65; 66.7%; 75% respectively, and accuracy of 87.5%; 64.3%; 65.7% respectively.Wells score has better sensitivity, specificity and accuracy than caprini and padua score in diagnosing DVT.

  1. A Initio Theoretical Studies of Surfaces of Semiconductors

    Science.gov (United States)

    Wang, Jing

    1993-01-01

    The first semiconductor which we study with these techniques is the archetypal elemental semiconductor, silicon. We present the first extensive study of point defects on Si(100). We identify the principal defects and two primary mechanisms responsible for their dominance: the need to eliminate dangling bonds on the surface and the need to compensate the strain induced by topological effects. Furthermore, we present evidence that the presence of point defects on the Si(100) surface is not intrinsic to the ground state of the surface as a stress relieving mechanism but rather is due merely to thermal fluctuations. We address materials issues associated with the identification of the lowest energy surfaces of GaAs and the determination of the geometric structure of a GaAs crystallite growing freely in three dimensions. The fracture energies associated with (110), (100) and (111) interface planes are calculated and a Wulff construction indicates that an ideal stoichiometric GaAs crystal should be terminated with (110) surfaces. We investigate the more complex issues that arise on surfaces when aspects of these two semiconductors are mixed. We investigate the problem of growing GaAs on the Si(100) surface and demonstrate how and why the most fundamental properties of the resulting bulk GaAs material, such as its crystalline orientation, may depend sensitively on the interplay between growth conditions such as temperature and the properties of the Si surface. For stepped Si(100) -As, we show that the growth of As directly on top of the Si surface produces a metastable state, while the replacement of the original top Si layer leads to a lower energy configuration, with the rearrangement of the surface driven by the relaxation of stress by surface steps. Finally, we study delta -doping, where one attempts to grow a single layer of Si on a GaAs surface before continuing with the growth of bulk GaAs. We shall employ a slightly different modality of the ab initio approach. We

  2. Ab Initio Calculation of Hyperfine Interaction Parameters: Recent Evolutions, Recent Examples

    International Nuclear Information System (INIS)

    Cottenier, Stefaan; Vanhoof, Veerle; Torumba, Doru; Bellini, Valerio; Cakmak, Mehmet; Rots, Michel

    2004-01-01

    For some years already, ab initio calculations based on Density Functional Theory (DFT) belong to the toolbox of the field of hyperfine interaction studies. In this paper, the standard ab initio approach is schematically sketched. New features, methods and possibilities that broke through during the past few years are listed, and their relation to the standard approach is explained. All this is illustrated by some highlights of recent ab initio work done by the Nuclear Condensed Matter Group at the K.U.Leuven.

  3. Correcting Grade Deflation Caused by Multiple-Choice Scoring.

    Science.gov (United States)

    Baranchik, Alvin; Cherkas, Barry

    2000-01-01

    Presents a study involving three sections of pre-calculus (n=181) at four-year college where partial credit scoring on multiple-choice questions was examined over an entire semester. Indicates that grades determined by partial credit scoring seemed more reflective of both the quantity and quality of student knowledge than grades determined by…

  4. Checklist for Evaluating SREB-SCORE Learning Objects

    Science.gov (United States)

    Southern Regional Education Board (SREB), 2007

    2007-01-01

    This checklist is based on "Evaluation Criteria for SREB-SCORE Learning Objects" and is designed to help schools and colleges determine the quality and effectiveness of learning objects. It is suggested that each learning object be rated to the extent to which it meets the criteria and the SREB-SCORE definition of a learning object. A learning…

  5. Simple calculation of ab initio melting curves: Application to aluminum.

    Science.gov (United States)

    Robert, Grégory; Legrand, Philippe; Arnault, Philippe; Desbiens, Nicolas; Clérouin, Jean

    2015-03-01

    We present a simple, fast, and promising method to compute the melting curves of materials with ab initio molecular dynamics. It is based on the two-phase thermodynamic model of Lin et al [J. Chem. Phys. 119, 11792 (2003)] and its improved version given by Desjarlais [Phys. Rev. E 88, 062145 (2013)]. In this model, the velocity autocorrelation function is utilized to calculate the contribution of the nuclei motion to the entropy of the solid and liquid phases. It is then possible to find the thermodynamic conditions of equal Gibbs free energy between these phases, defining the melting curve. The first benchmark on the face-centered cubic melting curve of aluminum from 0 to 300 GPa demonstrates how to obtain an accuracy of 5%-10%, comparable to the most sophisticated methods, for a much lower computational cost.

  6. Ab initio study of II-(VI){sub 2} dichalcogenides

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, P; Vidal, J; Lincot, D, E-mail: polsson@kth.se [Institut de R and D sur l' energie photovoltaique (IRDEP), UMR 7174-EDF-CNRS-ENSCP, 6 quai Watier, 78401 Chatou Cedex (France)

    2011-10-12

    The structural stabilities of the (Zn,Cd)(S,Se,Te){sub 2} dichalcogenides have been determined ab initio. These compounds are shown to be stable in the pyrite phase, in agreement with available experiments. Structural parameters for the ZnTe{sub 2} pyrite semiconductor compound proposed here are presented. The opto-electronic properties of these dichalcogenide compounds have been calculated using quasiparticle GW theory. Bandgaps, band structures and effective masses are proposed as well as absorption coefficients and refraction indices. The compounds are all indirect semiconductors with very flat conduction band dispersion and high absorption coefficients. The work functions and surface properties are predicted. The Te and Se based compounds could be of interest as absorber materials in photovoltaic applications. (paper)

  7. A hydronitrogen solid: high pressure ab initio evolutionary structure searches

    International Nuclear Information System (INIS)

    Hu Anguang; Zhang Fan

    2011-01-01

    High pressure ab initio evolutionary structure searches resulted in a hydronitrogen solid with a composition of (NH) 4 . The structure searches also provided two molecular isomers, ammonium azide (AA) and trans-tetrazene (TTZ) which were previously discovered experimentally and can be taken as molecular precursors for high pressure synthesis of the hydronitrogen solid. The computed pressure versus enthalpy diagram showed that the transformation pressure to the hydronitrogen solid is 36 GPa from AA and 75 GPa from TTZ. Its metastability was analyzed by the phonon dispersion spectrum and room-temperature vibrational density of state together with the transformation energy barrier back to molecular phases at 298 K. The predicted energy barrier of 0.21 eV/atom means that the proposed hydronitrogen solid should be very stable at ambient conditions. (fast track communication)

  8. High-throughput ab-initio dilute solute diffusion database.

    Science.gov (United States)

    Wu, Henry; Mayeshiba, Tam; Morgan, Dane

    2016-07-19

    We demonstrate automated generation of diffusion databases from high-throughput density functional theory (DFT) calculations. A total of more than 230 dilute solute diffusion systems in Mg, Al, Cu, Ni, Pd, and Pt host lattices have been determined using multi-frequency diffusion models. We apply a correction method for solute diffusion in alloys using experimental and simulated values of host self-diffusivity. We find good agreement with experimental solute diffusion data, obtaining a weighted activation barrier RMS error of 0.176 eV when excluding magnetic solutes in non-magnetic alloys. The compiled database is the largest collection of consistently calculated ab-initio solute diffusion data in the world.

  9. The ab-initio density matrix renormalization group in practice.

    Science.gov (United States)

    Olivares-Amaya, Roberto; Hu, Weifeng; Nakatani, Naoki; Sharma, Sandeep; Yang, Jun; Chan, Garnet Kin-Lic

    2015-01-21

    The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of accuracies can be obtained, and how do we reason about the computational difficulty in different molecules? By examining a diverse benchmark set of molecules: π-electron systems, benchmark main-group and transition metal dimers, and the Mn-oxo-salen and Fe-porphine organometallic compounds, we provide some answers to these questions, and show how the density matrix renormalization group is used in practice.

  10. The ab-initio density matrix renormalization group in practice

    Energy Technology Data Exchange (ETDEWEB)

    Olivares-Amaya, Roberto; Hu, Weifeng; Sharma, Sandeep; Yang, Jun; Chan, Garnet Kin-Lic [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Nakatani, Naoki [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Catalysis Research Center, Hokkaido University, Kita 21 Nishi 10, Sapporo, Hokkaido 001-0021 (Japan)

    2015-01-21

    The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of accuracies can be obtained, and how do we reason about the computational difficulty in different molecules? By examining a diverse benchmark set of molecules: π-electron systems, benchmark main-group and transition metal dimers, and the Mn-oxo-salen and Fe-porphine organometallic compounds, we provide some answers to these questions, and show how the density matrix renormalization group is used in practice.

  11. Quantitative verification of ab initio self-consistent laser theory.

    Science.gov (United States)

    Ge, Li; Tandy, Robert J; Stone, A D; Türeci, Hakan E

    2008-10-13

    We generalize and test the recent "ab initio" self-consistent (AISC) time-independent semiclassical laser theory. This self-consistent formalism generates all the stationary lasing properties in the multimode regime (frequencies, thresholds, internal and external fields, output power and emission pattern) from simple inputs: the dielectric function of the passive cavity, the atomic transition frequency, and the transverse relaxation time of the lasing transition.We find that the theory gives excellent quantitative agreement with full time-dependent simulations of the Maxwell-Bloch equations after it has been generalized to drop the slowly-varying envelope approximation. The theory is infinite order in the non-linear hole-burning interaction; the widely used third order approximation is shown to fail badly.

  12. Ab initio elastic properties and tensile strength of crystalline hydroxyapatite.

    Science.gov (United States)

    Ching, W Y; Rulis, Paul; Misra, A

    2009-10-01

    We report elastic constant calculation and a "theoretical" tensile experiment on stoichiometric hydroxyapatite (HAP) crystal using an ab initio technique. These results compare favorably with a variety of measured data. Theoretical tensile experiments are performed on the orthorhombic cell of HAP for both uniaxial and biaxial loading. The results show considerable anisotropy in the stress-strain behavior. It is shown that the failure behavior of the perfect HAP crystal is brittle for tension along the z-axis with a maximum stress of 9.6 GPa at 10% strain. Biaxial failure envelopes from six "theoretical" loading tests show a highly anisotropic pattern. Structural analysis of the crystal under various stages of tensile strain reveals that the deformation behavior manifests itself mainly in the rotation of the PO(4) tetrahedron with concomitant movements of both the columnar and axial Ca ions. These results are discussed in the context of mechanical properties of bioceramic composites relevant to mineralized tissues.

  13. Ab initio methods for electron-molecule collisions

    International Nuclear Information System (INIS)

    Collins, L.A.; Schneider, B.I.

    1987-01-01

    This review concentrates on the recent advances in treating the electronic aspect of the electron-molecule interaction and leaves to other articles the description of the rotational and vibrational motions. Those methods which give the most complete treatment of the direct, exchange, and correlation effects are focused on. Such full treatments are generally necessary at energies below a few Rydbergs (≅ 60 eV). This choice unfortunately necessitates omission of those active and vital areas devoted to the development of model potentials and approximate scattering formulations. The ab initio and model approaches complement each other and are both extremely important to the full explication of the electron-scattering process. Due to the rapid developments of recent years, the approaches that provide the fullest treatment are concentrated on. 81 refs

  14. Ab initio Eliashberg Theory: Making Genuine Predictions of Superconducting Features

    Science.gov (United States)

    Sanna, Antonio; Flores-Livas, José A.; Davydov, Arkadiy; Profeta, Gianni; Dewhurst, Kay; Sharma, Sangeeta; Gross, E. K. U.

    2018-04-01

    We present an application of Eliashberg theory of superconductivity to study a set of novel superconducting systems with a wide range of structural and chemical properties. The set includes three intercalated group-IV honeycomb layered structures, SH3 at 200 GPa (the superconductor with the highest measured critical temperature), the similar system SeH3 at 150 GPa, and a lithium doped mono-layer of black phosphorus. The theoretical approach we adopt is a recently developed, fully ab initio Eliashberg approach that takes into account the Coulomb interaction in a full energy-resolved fashion avoiding any free parameters like μ*. This method provides reasonable estimations of superconducting properties, including TC and the excitation spectra of superconductors.

  15. Ab Initio Symmetry-Adapted No-Core Shell Model

    International Nuclear Information System (INIS)

    Draayer, J P; Dytrych, T; Launey, K D

    2011-01-01

    A multi-shell extension of the Elliott SU(3) model, the SU(3) symmetry-adapted version of the no-core shell model (SA-NCSM), is described. The significance of this SA-NCSM emerges from the physical relevance of its SU(3)-coupled basis, which – while it naturally manages center-of-mass spuriosity – provides a microscopic description of nuclei in terms of mixed shape configurations. Since typically configurations of maximum spatial deformation dominate, only a small part of the model space suffices to reproduce the low-energy nuclear dynamics and hence, offers an effective symmetry-guided framework for winnowing of model space. This is based on our recent findings of low-spin and high-deformation dominance in realistic NCSM results and, in turn, holds promise to significantly enhance the reach of ab initio shell models.

  16. Ab Initio Analysis of Auger-Assisted Electron Transfer.

    Science.gov (United States)

    Hyeon-Deuk, Kim; Kim, Joonghan; Prezhdo, Oleg V

    2015-01-15

    Quantum confinement in nanoscale materials allows Auger-type electron-hole energy exchange. We show by direct time-domain atomistic simulation and analytic theory that Auger processes give rise to a new mechanism of charge transfer (CT) on the nanoscale. Auger-assisted CT eliminates the renown Marcus inverted regime, rationalizing recent experiments on CT from quantum dots to molecular adsorbates. The ab initio simulation reveals a complex interplay of the electron-hole and charge-phonon channels of energy exchange, demonstrating a variety of CT scenarios. The developed Marcus rate theory for Auger-assisted CT describes, without adjustable parameters, the experimental plateau of the CT rate in the region of large donor-acceptor energy gap. The analytic theory and atomistic insights apply broadly to charge and energy transfer in nanoscale systems.

  17. H3+: Ab initio calculation of the vibration spectrum

    International Nuclear Information System (INIS)

    Carney, G.D.; Porter, R.N.

    1976-01-01

    The vibration spectrum of H 3 + is calculated from the representation of a previously reported [J. Chem Phys. 60, 4251 (1974)] ab initio potential-energy surface in a fifth degree Simons--Parr--Finlan (SPF) expansion. Morse- and harmonic-oscillator basis functions are used to describe the motions of the three oscillators and the Harris--Engerholm--Gwinn quadrature technique is used to obtain matrix elements of the Hamiltonian in the basis of vibrational configurations. Our variational method is thus analogous to configuration--interaction calculations for electronic states. The ground state is found to have a zero-point energy of 4345 cm -1 and a vibrationally averaged geometry of R 1 =R 2 =0.91396 A, theta=60.0012degree, where theta is the angle between the two equivalent bonds. The transition frequencies for the E and A 1 fundamentals are nu-bar/sub E/=2516 cm -1 and nu-bar/sub A/=3185 cm -1 and those for the corresponding first overtones of the bending mode are 2nu-bar/sub E/=5004 +- 4 cm -1 and 2nu-bar/sub A/=4799 cm -1 . The first overtone of the breathing mode is 6264 cm -1 . The first-excited A 1 vibration state is metastable with a dipole--radiation lifetime of 3 sec. Transition frequencies, Einstein coefficients, and lifetimes are reported for a total of 21 transitions. Analysis of results for Dunham number and normal-coordinate expansions in comparison with those for SPF expansion show the latter to be superior for ab initio vibrational calculations. A scheme for possible direct measurement of the fundamental A 1 and E vibrational bands is suggested

  18. [Propensity score matching in SPSS].

    Science.gov (United States)

    Huang, Fuqiang; DU, Chunlin; Sun, Menghui; Ning, Bing; Luo, Ying; An, Shengli

    2015-11-01

    To realize propensity score matching in PS Matching module of SPSS and interpret the analysis results. The R software and plug-in that could link with the corresponding versions of SPSS and propensity score matching package were installed. A PS matching module was added in the SPSS interface, and its use was demonstrated with test data. Score estimation and nearest neighbor matching was achieved with the PS matching module, and the results of qualitative and quantitative statistical description and evaluation were presented in the form of a graph matching. Propensity score matching can be accomplished conveniently using SPSS software.

  19. Airline Quality Rating 2003

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2003-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2003, reflects monthly Airline Quality Rating scores for 2002. AQR scores for the calendar year 2002 are based on 15 elements that focus on airline performance areas important to air travel consumers. The Airline Quality Rating 2003 is a summary of month-by-month qualit...

  20. Airline Quality Rating 2013

    OpenAIRE

    Bowen, Brent D.; Headley, Dean E.

    2013-01-01

    The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method for assessing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2013, reflects monthly Airline Quality Rating scores for calendar year 2012. AQR scores for 2013 are based on 15 elements in four major areas that focus on airline performance aspects important to air travel consumers over the calendar year of 2012. The Airline Quality...

  1. ``Phantom'' Modes in Ab Initio Tunneling Calculations: Implications for Theoretical Materials Optimization, Tunneling, and Transport

    Science.gov (United States)

    Barabash, Sergey V.; Pramanik, Dipankar

    2015-03-01

    Development of low-leakage dielectrics for semiconductor industry, together with many other areas of academic and industrial research, increasingly rely upon ab initio tunneling and transport calculations. Complex band structure (CBS) is a powerful formalism to establish the nature of tunneling modes, providing both a deeper understanding and a guided optimization of materials, with practical applications ranging from screening candidate dielectrics for lowest ``ultimate leakage'' to identifying charge-neutrality levels and Fermi level pinning. We demonstrate that CBS is prone to a particular type of spurious ``phantom'' solution, previously deemed true but irrelevant because of a very fast decay. We demonstrate that (i) in complex materials, phantom modes may exhibit very slow decay (appearing as leading tunneling terms implying qualitative and huge quantitative errors), (ii) the phantom modes are spurious, (iii) unlike the pseudopotential ``ghost'' states, phantoms are an apparently unavoidable artifact of large numerical basis sets, (iv) a presumed increase in computational accuracy increases the number of phantoms, effectively corrupting the CBS results despite the higher accuracy achieved in resolving the true CBS modes and the real band structure, and (v) the phantom modes cannot be easily separated from the true CBS modes. We discuss implications for direct transport calculations. The strategy for dealing with the phantom states is discussed in the context of optimizing high-quality high- κ dielectric materials for decreased tunneling leakage.

  2. Erbium(III) in aqueous solution: an ab initio molecular dynamics study.

    Science.gov (United States)

    Canaval, Lorenz R; Sakwarathorn, Theerathad; Rode, Bernd M; Messner, Christoph B; Lutz, Oliver M D; Bonn, Günther K

    2013-12-05

    Structural and dynamical properties of the erbium(III) ion in water have been obtained by means of ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) simulations for the ground state and an excited state. The quality of the simulations has been monitored by recording UV/vis and Raman spectra of dilute solutions of ErCl3 and Er(NO3)3 in water and by comparison with EXAFS data from literature. Slight deviations between these data can be mainly attributed to relativistic effects, which are not sufficiently considered by the methodological framework. In both simulations, a mixture of coordination numbers eight and nine and a ligand exchange on the picosecond range are observed. The strength of the Er-ligand bond is considerably lower than that of trivalent transition metal ions but higher than that for La(III) and Ce(III) in aqueous solution. The main difference between ground state and excited state is the ligand exchange rate of the first shell. The second hydration shell is stable in both cases but with significantly different properties.

  3. Time-resolved photoelectron spectroscopy and ab initio multiple spawning studies of hexamethylcyclopentadiene

    DEFF Research Database (Denmark)

    Wolf, T. J. A.; Kuhlman, Thomas Scheby; Schalk, O.

    2014-01-01

    Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom.......Time-resolved photoelectron spectroscopy and ab initio multiple spawning were applied to the ultrafast non-adiabatic dynamics of hexamethylcyclopentadiene. The high level of agreement between experiment and theory associates wavepacket motion with a distinct degree of freedom....

  4. Permanent and induced dipole requirements in ab initio calculations of electron affinities of polar molecules

    International Nuclear Information System (INIS)

    Garrett, W.R.

    1979-01-01

    Through the use of a molecular pseudopotential method, we determine the a approximate magnitudes of errors that result when electron affinity determinations of polar negative ions are made through ab initio calculations in which the use of a given basis set yields inappropriate values for permanent and induced dipole moments of the neutral molecule. These results should prove useful in assessing the adequacy of basis sets in ab initio calculations of molecular electron affinities for simple linear polar molecules

  5. Ab Initio Molecular Dynamics Simulations of Furfural at the Liquid-Solid Interface

    OpenAIRE

    Sanwu Wang; Hongli Dang; Wenhua Xue; Darwin Shields; Xin Liu; Friederike C. Jentoft; Daniel E. Resasco

    2013-01-01

    The bonding configuration and the heat of adsorption of a furfural molecule on the Pd(111) surface were determined by ab initio density-functional-theory calculations. The dynamics of pure liquid water, the liquid-solid interface formed by liquid water and the Pd(111) surface, as well as furfural at the water-Pd interface, were investigated by ab initio molecular dynamics simulations at finite temperatures. Calculations and simulations suggest that the bonding configurati...

  6. Quadratic prediction of factor scores

    NARCIS (Netherlands)

    Wansbeek, T

    1999-01-01

    Factor scores are naturally predicted by means of their conditional expectation given the indicators y. Under normality this expectation is linear in y but in general it is an unknown function of y. II is discussed that under nonnormality factor scores can be more precisely predicted by a quadratic

  7. The Machine Scoring of Writing

    Science.gov (United States)

    McCurry, Doug

    2010-01-01

    This article provides an introduction to the kind of computer software that is used to score student writing in some high stakes testing programs, and that is being promoted as a teaching and learning tool to schools. It sketches the state of play with machines for the scoring of writing, and describes how these machines work and what they do.…

  8. Matching score based face recognition

    NARCIS (Netherlands)

    Boom, B.J.; Beumer, G.M.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2006-01-01

    Accurate face registration is of vital importance to the performance of a face recognition algorithm. We propose a new method: matching score based face registration, which searches for optimal alignment by maximizing the matching score output of a classifier as a function of the different

  9. Modelling sequentially scored item responses

    NARCIS (Netherlands)

    Akkermans, W.

    2000-01-01

    The sequential model can be used to describe the variable resulting from a sequential scoring process. In this paper two more item response models are investigated with respect to their suitability for sequential scoring: the partial credit model and the graded response model. The investigation is

  10. Carbon monoxide adsorption on alkali and proton-exchanged chabazite: an ab-initio periodic study using the CRYSTAL code

    Science.gov (United States)

    Ugliengo, P.; Busco, C.; Civalleri, B.; Zicovich-Wilson, C. M.

    Ab initio periodic calculations based on local Gaussian basis sets as coded in the CRYSTAL program have been performed to investigate the structure, the binding energy and the vibrational features of carbon monoxide adsorbed on H+, Li+, Na+ and K+-exchanged chabazite (Si/Al = 11/1, i.e. one Al atom per unit cell). The hybrid B3LYP functional has been adopted for all calculations with a polarized double-zeta quality basis set. The B3LYP binding energies (BSSE corrected) are 16.0, 24.6, 20.4 and 5.1 kJ/mol for H+, Li+, Na+ and K+-exchanged chabazite, respectively. Corresponding CO hypsochromic stretching frequency shifts are 47, 68, 43 and 33 cm-1, respectively. Comparison with the case of CO interacting with bare alkali cations and the available experimental data on a variety of zeolites has also been addressed.

  11. Evaluating Patient Activation Measure (PAM) Scores and Readmission Rates Following Implementation of a Nurse-Initiated Multi-Faceted Strategy for Patients on a U.S. Navy Inpatient Oncology Unit: A Quality Improvement Project

    Science.gov (United States)

    2016-06-30

    5b. GRANT NUMBER N/A of a Nurse-Initiated Multi-Faceted Strategy for Patients on a U.S. Navy Inpatient Oncology Unit: A Quality...13. SUPPLEMENTARY NOTES N/A 14. ABSTRACT Background: Chronically ill patients often experience multiple hospitalizations. Oncology patients...have been shown to have more readmissions to the hospital than non- oncology patients. Recent reports estimate a $17.4 billion cost burden is

  12. The Veterans Affairs Cardiac Risk Score: Recalibrating the Atherosclerotic Cardiovascular Disease Score for Applied Use.

    Science.gov (United States)

    Sussman, Jeremy B; Wiitala, Wyndy L; Zawistowski, Matthew; Hofer, Timothy P; Bentley, Douglas; Hayward, Rodney A

    2017-09-01

    Accurately estimating cardiovascular risk is fundamental to good decision-making in cardiovascular disease (CVD) prevention, but risk scores developed in one population often perform poorly in dissimilar populations. We sought to examine whether a large integrated health system can use their electronic health data to better predict individual patients' risk of developing CVD. We created a cohort using all patients ages 45-80 who used Department of Veterans Affairs (VA) ambulatory care services in 2006 with no history of CVD, heart failure, or loop diuretics. Our outcome variable was new-onset CVD in 2007-2011. We then developed a series of recalibrated scores, including a fully refit "VA Risk Score-CVD (VARS-CVD)." We tested the different scores using standard measures of prediction quality. For the 1,512,092 patients in the study, the Atherosclerotic cardiovascular disease risk score had similar discrimination as the VARS-CVD (c-statistic of 0.66 in men and 0.73 in women), but the Atherosclerotic cardiovascular disease model had poor calibration, predicting 63% more events than observed. Calibration was excellent in the fully recalibrated VARS-CVD tool, but simpler techniques tested proved less reliable. We found that local electronic health record data can be used to estimate CVD better than an established risk score based on research populations. Recalibration improved estimates dramatically, and the type of recalibration was important. Such tools can also easily be integrated into health system's electronic health record and can be more readily updated.

  13. Extension of the lod score: the mod score.

    Science.gov (United States)

    Clerget-Darpoux, F

    2001-01-01

    In 1955 Morton proposed the lod score method both for testing linkage between loci and for estimating the recombination fraction between them. If a disease is controlled by a gene at one of these loci, the lod score computation requires the prior specification of an underlying model that assigns the probabilities of genotypes from the observed phenotypes. To address the case of linkage studies for diseases with unknown mode of inheritance, we suggested (Clerget-Darpoux et al., 1986) extending the lod score function to a so-called mod score function. In this function, the variables are both the recombination fraction and the disease model parameters. Maximizing the mod score function over all these parameters amounts to maximizing the probability of marker data conditional on the disease status. Under the absence of linkage, the mod score conforms to a chi-square distribution, with extra degrees of freedom in comparison to the lod score function (MacLean et al., 1993). The mod score is asymptotically maximum for the true disease model (Clerget-Darpoux and Bonaïti-Pellié, 1992; Hodge and Elston, 1994). Consequently, the power to detect linkage through mod score will be highest when the space of models where the maximization is performed includes the true model. On the other hand, one must avoid overparametrization of the model space. For example, when the approach is applied to affected sibpairs, only two constrained disease model parameters should be used (Knapp et al., 1994) for the mod score maximization. It is also important to emphasize the existence of a strong correlation between the disease gene location and the disease model. Consequently, there is poor resolution of the location of the susceptibility locus when the disease model at this locus is unknown. Of course, this is true regardless of the statistics used. The mod score may also be applied in a candidate gene strategy to model the potential effect of this gene in the disease. Since, however, it

  14. EORTC QLQ-BM22 and QLQ-C30 quality of life scores in patients with painful bone metastases of prostate cancer treated with strontium-89 radionuclide therapy

    International Nuclear Information System (INIS)

    Kurosaka, Shinji; Satoh, Takefumi; Chow, E.

    2012-01-01

    Approximately 80% of patients with prostate cancer will develop bone metastases, which often lead to bone pain and skeletal-related events. Sr-89 is an established alternative for the palliation of bone pain in prostate cancer. We aimed to assess the effect of Sr-89 radionuclide therapy on quality of life (QOL) in prostate cancer patients with painful bone metastases. Thirteen patients received a single intravenous injection of Sr-89 at a dose of 2.0 MBq/kg. All patients underwent QOL evaluation prior to Sr-89 treatment and 1, 2, and 3 months afterward using the Japanese version of the European Organisation for Research and Treatment of Cancer developed a Quality of Life questionnaire for Patients with Bone Metastases 22(EORTC QLQ-BM22), EORTC Quality of Life Group core questionnaire (EORTC QLQ-C30), a visual analog scale (VAS), and face scale. We also evaluated prostate-specific antigen (PSA) and serum alkaline phosphatase (ALP) response and toxicity of the Sr-89 therapy. The pain characteristics subscale of the EORTC QLQ-BM22 was significantly reduced from 1 month onward compared with the baseline. The functional interference and psychosocial aspects subscales were significantly higher than baseline from 2 months onward. At 2 months, VAS indicated a significant reduction in pain as compared to the baseline. Sr-89 therapy caused a nonsignificant reduction in PSA and ALP levels. No patients had leukocyte toxicity, and one patient had grade 3 platelet toxicity. Sr-89 radionuclide therapy can provide not only reduced pain characteristics but also better psychosocial aspects and functional interference in patients with painful bone metastases of prostate cancer. (author)

  15. IW-Scoring: an Integrative Weighted Scoring framework for annotating and prioritizing genetic variations in the noncoding genome.

    Science.gov (United States)

    Wang, Jun; Dayem Ullah, Abu Z; Chelala, Claude

    2018-01-30

    The vast majority of germline and somatic variations occur in the noncoding part of the genome, only a small fraction of which are believed to be functional. From the tens of thousands of noncoding variations detectable in each genome, identifying and prioritizing driver candidates with putative functional significance is challenging. To address this, we implemented IW-Scoring, a new Integrative Weighted Scoring model to annotate and prioritise functionally relevant noncoding variations. We evaluate 11 scoring methods, and apply an unsupervised spectral approach for subsequent selective integration into two linear weighted functional scoring schemas for known and novel variations. IW-Scoring produces stable high-quality performance as the best predictors for three independent data sets. We demonstrate the robustness of IW-Scoring in identifying recurrent functional mutations in the TERT promoter, as well as disease SNPs in proximity to consensus motifs and with gene regulatory effects. Using follicular lymphoma as a paradigmatic cancer model, we apply IW-Scoring to locate 11 recurrently mutated noncoding regions in 14 follicular lymphoma genomes, and validate 9 of these regions in an extension cohort, including the promoter and enhancer regions of PAX5. Overall, IW-Scoring demonstrates greater versatility in identifying trait- and disease-associated noncoding variants. Scores from IW-Scoring as well as other methods are freely available from http://www.snp-nexus.org/IW-Scoring/. © The Author(s) 2018. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. Many-body perturbation theory for ab initio nuclear structure

    International Nuclear Information System (INIS)

    Tichai, Alexander

    2017-01-01

    The solution of the quantum many-body problem for medium-mass nuclei using realistic nuclear interactions poses a superbe challenge for nuclear structure research. Because an exact solution can only be provided for the lightest nuclei, one has to rely on approximate solutions when proceeding to heavier systems. Over the past years, tremendous progress has been made in the development and application of systematically improvable expansion methods and an accurate description of nuclear observables has become viable up to mass number A ∼ 100. While closed-shell systems are consistently described via a plethora of different many-body methods, the extension to genuine open-shell systems still remains a major challenge and up to now there is no ab initio many-body method which applies equally well to systems with even and odd mass numbers. The goal of this thesis is the development and implementation of innovative perturbative approaches with genuine open-shell capabilities. This requires the extension of well-known single-reference approaches to more general vacua. In this work we choose two complementary routes for the usage of generalized reference states. First, we derive a new ab initio approach based on multi-configurational reference states that are conveniently derived from a prior no-core shell model calculation. Perturbative corrections are derived via second-order many-body perturbation theory, thus, merging configuration interaction and many-body perturbation theory. The generality of this ansatz enables for a treatment of medium-mass systems with arbitrary mass number, as well as the extension to low-lying excited states such that ground and excited states are treated on an equal footing. In a complementary approach, we use reference states that break a symmetry of the underlying Hamiltonian. In the simplest case this corresponds to the expansion around a particle-number-broken Hartree-Fock-Bogolyubov vacuum which is obtained from a mean-field calculation

  17. Ab initio molecular crystal structures, spectra, and phase diagrams.

    Science.gov (United States)

    Hirata, So; Gilliard, Kandis; He, Xiao; Li, Jinjin; Sode, Olaseni

    2014-09-16

    Conspectus Molecular crystals are chemists' solids in the sense that their structures and properties can be understood in terms of those of the constituent molecules merely perturbed by a crystalline environment. They form a large and important class of solids including ices of atmospheric species, drugs, explosives, and even some organic optoelectronic materials and supramolecular assemblies. Recently, surprisingly simple yet extremely efficient, versatile, easily implemented, and systematically accurate electronic structure methods for molecular crystals have been developed. The methods, collectively referred to as the embedded-fragment scheme, divide a crystal into monomers and overlapping dimers and apply modern molecular electronic structure methods and software to these fragments of the crystal that are embedded in a self-consistently determined crystalline electrostatic field. They enable facile applications of accurate but otherwise prohibitively expensive ab initio molecular orbital theories such as Møller-Plesset perturbation and coupled-cluster theories to a broad range of properties of solids such as internal energies, enthalpies, structures, equation of state, phonon dispersion curves and density of states, infrared and Raman spectra (including band intensities and sometimes anharmonic effects), inelastic neutron scattering spectra, heat capacities, Gibbs energies, and phase diagrams, while accounting for many-body electrostatic (namely, induction or polarization) effects as well as two-body exchange and dispersion interactions from first principles. They can fundamentally alter the role of computing in the studies of molecular crystals in the same way ab initio molecular orbital theories have transformed research practices in gas-phase physical chemistry and synthetic chemistry in the last half century. In this Account, after a brief summary of formalisms and algorithms, we discuss applications of these methods performed in our group as compelling

  18. Thermophysical properties of krypton-helium gas mixtures from ab initio pair potentials.

    Science.gov (United States)

    Jäger, Benjamin; Bich, Eckard

    2017-06-07

    A new potential energy curve for the krypton-helium atom pair was developed using supermolecular ab initio computations for 34 interatomic distances. Values for the interaction energies at the complete basis set limit were obtained from calculations with the coupled-cluster method with single, double, and perturbative triple excitations and correlation consistent basis sets up to sextuple-zeta quality augmented with mid-bond functions. Higher-order coupled-cluster excitations up to the full quadruple level were accounted for in a scheme of successive correction terms. Core-core and core-valence correlation effects were included. Relativistic corrections were considered not only at the scalar relativistic level but also using full four-component Dirac-Coulomb and Dirac-Coulomb-Gaunt calculations. The fitted analytical pair potential function is characterized by a well depth of 31.42 K with an estimated standard uncertainty of 0.08 K. Statistical thermodynamics was applied to compute the krypton-helium cross second virial coefficients. The results show a very good agreement with the best experimental data. Kinetic theory calculations based on classical and quantum-mechanical approaches for the underlying collision dynamics were utilized to compute the transport properties of krypton-helium mixtures in the dilute-gas limit for a large temperature range. The results were analyzed with respect to the orders of approximation of kinetic theory and compared with experimental data. Especially the data for the binary diffusion coefficient confirm the predictive quality of the new potential. Furthermore, inconsistencies between two empirical pair potential functions for the krypton-helium system from the literature could be resolved.

  19. Single-ion 4f element magnetism: an ab-initio look at Ln(COT)2(-).

    Science.gov (United States)

    Gendron, Frédéric; Pritchard, Benjamin; Bolvin, Hélène; Autschbach, Jochen

    2015-12-14

    The electron densities associated with the Ln 4f shell, and spin and orbital magnetizations ('magnetic moment densities'), are investigated for the Ln(COT)2(-) series. The densities are obtained from ab-initio calculations including spin-orbit coupling. For Ln = Ce, Pr the magnetizations are also derived from crystal field models and shown to agree with the ab-initio results. Analysis of magnetizations from ab-initio calculations may be useful in assisting research on single molecule magnets.

  20. Association between value-based purchasing score and hospital characteristics

    Directory of Open Access Journals (Sweden)

    Borah Bijan J

    2012-12-01

    Full Text Available Abstract Background Medicare hospital Value-based purchasing (VBP program that links Medicare payments to quality of care will become effective from 2013. It is unclear whether specific hospital characteristics are associated with a hospital’s VBP score, and consequently incentive payments. The objective of the study was to assess the association of hospital characteristics with (i the mean VBP score, and (ii specific percentiles of the VBP score distribution. The secondary objective was to quantify the associations of hospital characteristics with the VBP score components: clinical process of care (CPC score and patient satisfaction score. Methods Observational analysis that used data from three sources: Medicare Hospital Compare Database, American Hospital Association 2010 Annual Survey and Medicare Impact File. The final study sample included 2,491 U.S. acute care hospitals eligible for the VBP program. The association of hospital characteristics with the mean VBP score and specific VBP score percentiles were assessed by ordinary least square (OLS regression and quantile regression (QR, respectively. Results VBP score had substantial variations, with mean score of 30 and 60 in the first and fourth quartiles of the VBP score distribution. For-profit status (vs. non-profit, smaller bed size (vs. 100–199 beds, East South Central region (vs. New England region and the report of specific CPC measures (discharge instructions, timely provision of antibiotics and beta blockers, and serum glucose controls in cardiac surgery patients were positively associated with mean VBP scores (p Conclusions Although hospitals serving the poor and the elderly are more likely to score lower under the VBP program, the correlation appears small. Profit status, geographic regions, number and type of CPC measures reported explain the most variation among scores.

  1. From Rasch scores to regression

    DEFF Research Database (Denmark)

    Christensen, Karl Bang

    2006-01-01

    Rasch models provide a framework for measurement and modelling latent variables. Having measured a latent variable in a population a comparison of groups will often be of interest. For this purpose the use of observed raw scores will often be inadequate because these lack interval scale propertie....... This paper compares two approaches to group comparison: linear regression models using estimated person locations as outcome variables and latent regression models based on the distribution of the score....

  2. Zirconium - ab initio modelling of point defects diffusion

    International Nuclear Information System (INIS)

    Gasca, Petrica

    2010-01-01

    Zirconium is the main element of the cladding found in pressurized water reactors, under an alloy form. Under irradiation, the cladding elongate significantly, phenomena attributed to the vacancy dislocation loops growth in the basal planes of the hexagonal compact structure. The understanding of the atomic scale mechanisms originating this process motivated this work. Using the ab initio atomic modeling technique we studied the structure and mobility of point defects in Zirconium. This led us to find four interstitial point defects with formation energies in an interval of 0.11 eV. The migration paths study allowed the discovery of activation energies, used as entry parameters for a kinetic Monte Carlo code. This code was developed for calculating the diffusion coefficient of the interstitial point defect. Our results suggest a migration parallel to the basal plane twice as fast as one parallel to the c direction, with an activation energy of 0.08 eV, independent of the direction. The vacancy diffusion coefficient, estimated with a two-jump model, is also anisotropic, with a faster process in the basal planes than perpendicular to them. Hydrogen influence on the vacancy dislocation loops nucleation was also studied, due to recent experimental observations of cladding growth acceleration in the presence of this element [fr

  3. Thermal, spectroscopic, and ab initio structural characterization of carprofen polymorphs.

    Science.gov (United States)

    Bruni, Giovanna; Gozzo, Fabia; Capsoni, Doretta; Bini, Marcella; Macchi, Piero; Simoncic, Petra; Berbenni, Vittorio; Milanese, Chiara; Girella, Alessandro; Ferrari, Stefania; Marini, Amedeo

    2011-06-01

    Commercial and recrystallized polycrystalline samples of carprofen, a nonsteroidal anti-inflammatory drug, were studied by thermal, spectroscopic, and structural techniques. Our investigations demonstrated that recrystallized sample, stable at room temperature (RT), is a single polymorphic form of carprofen (polymorph I) that undergoes an isostructural polymorphic transformation by heating (polymorph II). Polymorph II remains then metastable at ambient conditions. Commercial sample is instead a mixture of polymorphs I and II. The thermodynamic relationships between the two polymorphs were determined through the construction of an energy/temperature diagram. The ab initio structural determination performed on synchrotron X-Ray powder diffraction patterns recorded at RT on both polymorphs allowed us to elucidate, for the first time, their crystal structure. Both crystallize in the monoclinic space group type P2(1) /c, and the unit cell similarity index and the volumetric isostructurality index indicate that the temperature-induced polymorphic transformation I → II is isostructural. Polymorphs I and II are conformational polymorphs, sharing a very similar hydrogen bond network, but with different conformation of the propanoic skeleton, which produces two different packing. The small conformational change agrees with the low value of transition enthalpy obtained by differential scanning calorimetry measurements and the small internal energy computed with density functional methods. Copyright © 2011 Wiley-Liss, Inc.

  4. Ab Initio Liquid Water Dynamics in Aqueous TMAO Solution.

    Science.gov (United States)

    Usui, Kota; Hunger, Johannes; Sulpizi, Marialore; Ohto, Tatsuhiko; Bonn, Mischa; Nagata, Yuki

    2015-08-20

    Ab initio molecular dynamics (AIMD) simulations in trimethylamine N-oxide (TMAO)-D2O solution are employed to elucidate the effects of TMAO on the reorientational dynamics of D2O molecules. By decomposing the O-D groups of the D2O molecules into specific subensembles, we reveal that water reorientational dynamics are retarded considerably in the vicinity of the hydrophilic TMAO oxygen (O(TMAO)) atom, due to the O-D···O(TMAO) hydrogen-bond. We find that this reorientational motion is governed by two distinct mechanisms: The O-D group rotates (1) after breaking the O-D···O(TMAO) hydrogen-bond, or (2) together with the TMAO molecule while keeping this hydrogen-bond intact. While the orientational slow-down is prominent in the AIMD simulation, simulations based on force field models exhibit much faster dynamics. The simulated angle-resolved radial distribution functions illustrate that the O-D···O(TMAO) hydrogen-bond has a strong directionality through the sp(3) orbital configuration in the AIMD simulation, and this directionality is not properly accounted for in the force field simulation. These results imply that care must be taken when modeling negatively charged oxygen atoms as single point charges; force field models may not adequately describe the hydration configuration and dynamics.

  5. Ab initio modeling of the motional Stark effect on MAST

    International Nuclear Information System (INIS)

    De Bock, M. F. M.; Conway, N. J.; Walsh, M. J.; Carolan, P. G.; Hawkes, N. C.

    2008-01-01

    A multichord motional Stark effect (MSE) system has recently been built on the MAST tokamak. In MAST the π and σ lines of the MSE spectrum overlap due to the low magnetic field typical for present day spherical tokamaks. Also, the field curvature results in a large change in the pitch angle over the observation volume. The measured polarization angle does not relate to one local pitch angle but to an integration over all pitch angles in the observation volume. The velocity distribution of the neutral beam further complicates the measurement. To take into account volume effects and velocity distribution, an ab initio code was written that simulates the MSE spectrum on MAST. The code is modular and can easily be adjusted for other tokamaks. The code returns the intensity, polarized fraction, and polarization angle as a function of wavelength. Results of the code are presented, showing the effect on depolarization and wavelength dependence of the polarization angle. The code is used to optimize the design and calibration of the MSE diagnostic.

  6. Ab initio modelling of transition metals in diamond

    International Nuclear Information System (INIS)

    Watkins, M; Mainwood, A

    2003-01-01

    Transition metals (TM) from the first transition series are commonly used as solvent catalysts in the synthesis of diamond by high pressure, high temperature processes. Ab initio calculations on these metals, in finite clusters of tetrahedrally coordinated carbon, enable us to investigate trends in their stability and properties. By carrying out systematic studies of interstitial, substitutional and semi-vacancy TM defects, we show that the electronic structure of the TMs is complicated by the presence of 'dangling bonds' when the TM disrupts the crystal lattice: interstitial defects conform to the Ludwig-Woodbury (LW) model, whilst substitutional and semi-vacancy defects move from approximating the LW model early in the transition series to approaching the vacancy model for the heavier metals. Multi-configurational self-consistent field methods allow genuine many-electron states to be modelled; for neutral interstitial, and all substitutional TMs, the crystal fields are found to exceed the exchange energies in strength. Consequently, low spin states are found for these defects. We find substitutional defects to be the most stable, but that semi-vacancy TMs are very similar in energy to the substitutional defects late in the transition series; interstitial defects are only metastable in diamond. Given appropriate charge compensators neutral and positively charged interstitial TM defects were stable, while negatively charged species appeared to be strongly disfavoured

  7. Predicting lattice thermal conductivity with help from ab initio methods

    Science.gov (United States)

    Broido, David

    2015-03-01

    The lattice thermal conductivity is a fundamental transport parameter that determines the utility a material for specific thermal management applications. Materials with low thermal conductivity find applicability in thermoelectric cooling and energy harvesting. High thermal conductivity materials are urgently needed to help address the ever-growing heat dissipation problem in microelectronic devices. Predictive computational approaches can provide critical guidance in the search and development of new materials for such applications. Ab initio methods for calculating lattice thermal conductivity have demonstrated predictive capability, but while they are becoming increasingly efficient, they are still computationally expensive particularly for complex crystals with large unit cells . In this talk, I will review our work on first principles phonon transport for which the intrinsic lattice thermal conductivity is limited only by phonon-phonon scattering arising from anharmonicity. I will examine use of the phase space for anharmonic phonon scattering and the Grüneisen parameters as measures of the thermal conductivities for a range of materials and compare these to the widely used guidelines stemming from the theory of Liebfried and Schölmann. This research was supported primarily by the NSF under Grant CBET-1402949, and by the S3TEC, an Energy Frontier Research Center funded by the US DOE, office of Basic Energy Sciences under Award No. DE-SC0001299.

  8. Physical properties of molybdenum monoboride: Ab-initio study

    Science.gov (United States)

    Rajpoot, Priyanka; Rastogi, Anugya; Verma, U. P.

    2018-02-01

    The Ab initio investigations on structural, electronic, optical and thermal properties of MoB have been reported using full potential linearised-augmented plane wave method within the framework of density functional theory. The exchange and correlation potentials were calculated using the Perdew-Burke-Ernzerhof-Sol generalised gradient approximation. The calculated equilibrium lattice constants and cell volume are in excellent agreement with the experimental results as compared to the available theoretical data. Electronic band structure shows that MoB is metallic in nature. From the partial densities of states of MoB it has been found that major contribution on the Fermi level is due to Mo-4d states. Among the reported optical parameters the large value of reflectivity at low energy shows that MoB can be used as a coating material in IR region. Maximum absorption in extreme UV region shows that it can be used in production of electricity through solar power in space vehicles. Various thermal properties have been calculated in a wide temperature range at high pressures. Change in thermal expansion coefficient with respect to temperature shows that anharmonic effect in MoB is very weak at high temperature. The optical and thermal properties of MoB are presented for the first time in this work.

  9. Development of materials science by Ab initio powder diffraction analysis

    International Nuclear Information System (INIS)

    Fujii, Kotaro

    2015-01-01

    Crystal structure is most important information to understand properties and behavior of target materials. Technique to analyze unknown crystal structures from powder diffraction data (ab initio powder diffraction analysis) enables us to reveal crystal structures of target materials even we cannot obtain a single crystal. In the present article, three examples are introduced to show the power of this technique in the field of materials sciences. The first example is dehydration/hydration of the pharmaceutically relevant material erythrocycin A. In this example, crystal structures of two anhydrous phases were determined from synchrotron X-ray powder diffraction data and their different dehydration/hydration properties were understood from the crystal structures. In the second example, a crystal structure of a three dimensional metal-organic-framework prepared by a mechanochemical reaction was determined from laboratory X-ray powder diffraction data and the reaction scheme has been revealed. In the third example, a crystal structure of a novel oxide-ion conductor of a new structure family was determined from synchrotron X-ray and neutron powder diffraction data which gave an important information to understand the mechanism of the oxide-ion conduction. (author)

  10. Ab-initio calculations for dilute magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Belhadji, Brahim

    2008-03-03

    This thesis focusses on ab-initio calculations for the electronic structure and the magnetic properties of dilute magnetic semiconductors (DMS). In particular we aim at the understanding of the complex exchange interactions in these systems. Our calculations are based on density functional theory, being ideally suited for a description of the material specific properties of the considered DMS. Moreover we use the KKR Green function method in connection with the coherent potential approximation (CPA), which allows to include the random substitutional disorder in a mean field-like approximation for the electronic structure. Finally we calculate the exchange coupling constants J{sub ij} between two impurities in a CPA medium by using the Lichtenstein formula and from this calculate the Curie temperature by a numerically exact Monte Carlo method. Based on this analysis we found and investigated four different exchange mechanisms being of importance in DMS systems: Double exchange, p-d exchange, antiferromagnetic superexchanges, and ferromagnetic superexchange. A second topic we have investigated in this thesis is the pressure dependence of the exchange interactions and the Curie temperatures in (Ga,Mn)As and (In,Mn)As, using the LDA and the LDA+U approximations. Exact calculations of T{sub C} by Monte Carlo simulations show a somehow different behavior. (orig.)

  11. Ab initio transport across bismuth selenide surface barriers

    KAUST Repository

    Narayan, Awadhesh

    2014-11-24

    © 2014 American Physical Society. We investigate the effect of potential barriers in the form of step edges on the scattering properties of Bi2Se3(111) topological surface states by means of large-scale ab initio transport simulations. Our results demonstrate the suppression of perfect backscattering, while all other scattering processes, which do not entail a complete spin and momentum reversal, are allowed. Furthermore, we find that the spin of the surface state develops an out-of-plane component as it traverses the barrier. Our calculations reveal the existence of quasibound states in the vicinity of the surface barriers, which appear in the form of an enhanced density of states in the energy window corresponding to the topological state. For double barriers we demonstrate the formation of quantum well states. To complement our first-principles results we construct a two-dimensional low-energy effective model and illustrate its shortcomings. Our findings are discussed in the context of a number of recent experimental works.

  12. Ab initio study of MgH2 formation

    International Nuclear Information System (INIS)

    Novakovic, Nikola; Matovic, Ljiljana; Novakovic, Jasmina Grbovic; Manasijevic, Miodrag; Ivanovic, Nenad

    2009-01-01

    Even if there is considerable literature dealing with structure and properties of MgH 2 compound there are still some uncertain details about nature of bonding governing its formation and decomposition. In order to better understand the processes essential for absorption and desorption of MgH 2 , ab initio DFT based calculations of rutile MgH 2 compound, elemental hcp-Mg, and three different hypothetical hcp-Mg-derived hydrides are performed. Our findings show that all structures are unstable, and that MgH (Wurtzite) is a closest possible candidate for intermediate phase between the hcp-Mg and MgH 2 at 1:1 stoichiometry. An alternative hydration pathway is suggested, including promotion of hcp-Mg to bcc-Mg and consecutive transformation to rutile MgH 2 by means of hydrogen incorporation into Mg matrix. Rutile MgH 2 calculations with various hydrogen vacancies concentration are performed. Calculation shows that at high hydrogen concentration close to 1:2, stable substoichiometric hydride is possible. Calculation also shows that high vacancy (low hydrogen) concentration favors bcc-Mg 2 H over rutile Mg 2 H structure.

  13. Double-walled silicon nanotubes: an ab initio investigation

    Science.gov (United States)

    Lima, Matheus P.

    2018-02-01

    The synthesis of silicon nanotubes realized in the last decade demonstrates multi-walled tubular structures consisting of Si atoms in {{sp}}2 and the {{sp}}3 hybridizations. However, most of the theoretical models were elaborated taking as the starting point {{sp}}2 structures analogous to carbon nanotubes. These structures are unfavorable due to the natural tendency of the Si atoms to undergo {{sp}}3. In this work, through ab initio simulations based on density functional theory, we investigated double-walled silicon nanotubes proposing layered tubes possessing most of the Si atoms in an {{sp}}3 hybridization, and with few {{sp}}2 atoms localized at the outer wall. The lowest-energy structures have metallic behavior. Furthermore, the possibility to tune the band structure with the application of a strain was demonstrated, inducing a metal-semiconductor transition. Thus, the behavior of silicon nanotubes differs significantly from carbon nanotubes, and the main source of the differences is the distortions in the lattice associated with the tendency of Si to make four chemical bonds.

  14. Domain Wall Formation in Ferromagnetic Layers: An Ab Initio Study

    Science.gov (United States)

    Herper, Heike C.

    Domain walls are an inherent feature of ferromagnetic (FM) films consisting of layers with different magnetic orientations. Since FM films are used in electrical devices the question of the influence of domain walls on, e.g., the magnetoresistance has attracted much interest. Besides discussing the resistance contribution of domain walls, it is appropriate to study different types of domain walls and their energy of formation. The behaviour of domain walls is usually discussed within model calculations. In the present paper it is done within an ab initio Green's function technique for layered systems, i.e., the fully relativistic, spin-polarized screened Korringa-Kohn Rostoker method. Results are presented for fcc Co layers covered by two semi-infinite fcc Pt(001) bulk systems or by bulk fcc Co(001), respectively. The resistance, which is caused by the different types of domain walls is discussed within a Kubo-Greenwood approach considering Co(001)/Co24/Co(001) as an example.

  15. Ab initio study of point defects in magnesium oxide

    International Nuclear Information System (INIS)

    Gilbert, C. A.; Kenny, S. D.; Smith, R.; Sanville, E.

    2007-01-01

    Energetics of a variety of point defects in MgO have been considered from an ab initio perspective using density functional theory. The considered defects are isolated Schottky and Frenkel defects and interstitial pairs, along with a number of Schottky defects and di-interstitials. Comparisons were made between the density functional theory results and results obtained from empirical potential simulations and these generally showed good agreement. Both methodologies predicted the first nearest neighbor Schottky defects to be the most energetically favorable of the considered Schottky defects and that the first, second, and fifth nearest neighbor di-interstitials were of similar energy and were favored over the other di-interstitial configurations. Relaxed structures of the defects were analyzed, which showed that empirical potential simulations were accurately predicting the displacements of atoms surrounding di-interstitials, but were overestimating O atom displacement for Schottky defects. Transition barriers were computed for the defects using the nudged elastic band method. Vacancies and Schottky defects were found to have relatively high energy barriers, the majority of which were over 2 eV, in agreement with conclusions reached using empirical potentials. The lowest barriers for di-interstitial transitions were found to be for migration into a first nearest neighbor configuration. Charges were calculated using a Bader analysis and this found negligible charge transfer during the defect transitions and only small changes in the charges on atoms surrounding defects, indicating why fixed charge models work as well as they do

  16. Ab initio modelling of methane hydrate thermophysical properties.

    Science.gov (United States)

    Jendi, Z M; Servio, P; Rey, A D

    2016-04-21

    The key thermophysical properties of methane hydrate were determined using ab initio modelling. Using density functional theory, the second-order elastic constants, heat capacity, compressibility, and thermal expansion coefficient were calculated. A wide and relevant range of pressure-temperature conditions were considered, and the structures were assessed for stability using the mean square displacement and radial distribution functions. Methane hydrate was found to be elastically isotropic with a linear dependence of the bulk modulus on pressure. Equally significant, multi-body interactions were found to be important in hydrates, and water-water interactions appear to strongly influence compressibility like in ice Ih. While the heat capacity of hydrate was found to be higher than that of ice, the thermal expansion coefficient was significantly lower, most likely due to the lower rigidity of hydrates. The mean square displacement gave important insight into stability, heat capacity, and elastic moduli, and the radial distribution functions further confirmed stability. The presented results provide a much needed atomistic thermoelastic characterization of methane hydrates and are essential input for the large-scale applications of hydrate detection and production.

  17. 4He Thermophysical Properties: New Ab Initio Calculations

    Science.gov (United States)

    Hurly, John J.; Mehl, James B.

    2007-01-01

    Since 2000, atomic physicists have reduced the uncertainty of the helium-helium “ab initio” potential; for example, from approximately 0.6 % to 0.1 % at 4 bohr, and from 0.8 % to 0.1 % at 5.6 bohr. These results led us to: (1) construct a new inter-atomic potential ϕ07, (2) recalculate values of the second virial coefficient, the viscosity, and the thermal conductivity of 4He from 1 K to 10,000 K, and (3), analyze the uncertainties of the thermophysical properties that propagate from the uncertainty of ϕ07 and from the Born-Oppenheimer approximation of the electron-nucleon quantum mechanical system. We correct minor errors in a previous publication [J. J. Hurly and M. R. Moldover, J. Res. Nat. Inst. Standards Technol. 105, 667 (2000)] and compare our results with selected data published after 2000. The ab initio results tabulated here can serve as standards for the measurement of thermophysical properties. PMID:27110456

  18. Accurate ab initio vibrational energies of methyl chloride

    International Nuclear Information System (INIS)

    Owens, Alec; Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan; Thiel, Walter

    2015-01-01

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH 3 35 Cl and CH 3 37 Cl. The respective PESs, CBS-35  HL , and CBS-37  HL , are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY 3 Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35  HL and CBS-37  HL PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm −1 , respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH 3 Cl without empirical refinement of the respective PESs

  19. Accurate ab initio vibrational energies of methyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Alec, E-mail: owens@mpi-muelheim.mpg.de [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany); Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Thiel, Walter [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany)

    2015-06-28

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH{sub 3}{sup 35}Cl and CH{sub 3}{sup 37}Cl. The respective PESs, CBS-35{sup  HL}, and CBS-37{sup  HL}, are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY {sub 3}Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35{sup  HL} and CBS-37{sup  HL} PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm{sup −1}, respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH{sub 3}Cl without empirical refinement of the respective PESs.

  20. Re-Scoring the Game’s Score

    DEFF Research Database (Denmark)

    Gasselseder, Hans-Peter

    2014-01-01

    This study explores immersive presence as well as emotional valence and arousal in the context of dynamic and non-dynamic music scores in the 3rd person action-adventure video game genre while also considering relevant personality traits of the player. 60 subjects answered self-report questionnai......This study explores immersive presence as well as emotional valence and arousal in the context of dynamic and non-dynamic music scores in the 3rd person action-adventure video game genre while also considering relevant personality traits of the player. 60 subjects answered self......-temporal alignment in the resulting emotional congruency of nondiegetic music. Whereas imaginary aspects of immersive presence are systemically affected by the presentation of dynamic music, sensory spatial aspects show higher sensitivity towards the arousal potential of the music score. It is argued...

  1. Ab-initio conformational epitope structure prediction using genetic algorithm and SVM for vaccine design.

    Science.gov (United States)

    Moghram, Basem Ameen; Nabil, Emad; Badr, Amr

    2018-01-01

    T-cell epitope structure identification is a significant challenging immunoinformatic problem within epitope-based vaccine design. Epitopes or antigenic peptides are a set of amino acids that bind with the Major Histocompatibility Complex (MHC) molecules. The aim of this process is presented by Antigen Presenting Cells to be inspected by T-cells. MHC-molecule-binding epitopes are responsible for triggering the immune response to antigens. The epitope's three-dimensional (3D) molecular structure (i.e., tertiary structure) reflects its proper function. Therefore, the identification of MHC class-II epitopes structure is a significant step towards epitope-based vaccine design and understanding of the immune system. In this paper, we propose a new technique using a Genetic Algorithm for Predicting the Epitope Structure (GAPES), to predict the structure of MHC class-II epitopes based on their sequence. The proposed Elitist-based genetic algorithm for predicting the epitope's tertiary structure is based on Ab-Initio Empirical Conformational Energy Program for Peptides (ECEPP) Force Field Model. The developed secondary structure prediction technique relies on Ramachandran Plot. We used two alignment algorithms: the ROSS alignment and TM-Score alignment. We applied four different alignment approaches to calculate the similarity scores of the dataset under test. We utilized the support vector machine (SVM) classifier as an evaluation of the prediction performance. The prediction accuracy and the Area Under Receiver Operating Characteristic (ROC) Curve (AUC) were calculated as measures of performance. The calculations are performed on twelve similarity-reduced datasets of the Immune Epitope Data Base (IEDB) and a large dataset of peptide-binding affinities to HLA-DRB1*0101. The results showed that GAPES was reliable and very accurate. We achieved an average prediction accuracy of 93.50% and an average AUC of 0.974 in the IEDB dataset. Also, we achieved an accuracy of 95

  2. Missing data methods for dealing with missing items in quality of life questionnaires. A comparison by simulation of personal mean score, full information maximum likelihood, multiple imputation, and hot deck techniques applied to the SF-36 in the French 2003 decennial health survey.

    Science.gov (United States)

    Peyre, Hugo; Leplège, Alain; Coste, Joël

    2011-03-01

    Missing items are common in quality of life (QoL) questionnaires and present a challenge for research in this field. It remains unclear which of the various methods proposed to deal with missing data performs best in this context. We compared personal mean score, full information maximum likelihood, multiple imputation, and hot deck techniques using various realistic simulation scenarios of item missingness in QoL questionnaires constructed within the framework of classical test theory. Samples of 300 and 1,000 subjects were randomly drawn from the 2003 INSEE Decennial Health Survey (of 23,018 subjects representative of the French population and having completed the SF-36) and various patterns of missing data were generated according to three different item non-response rates (3, 6, and 9%) and three types of missing data (Little and Rubin's "missing completely at random," "missing at random," and "missing not at random"). The missing data methods were evaluated in terms of accuracy and precision for the analysis of one descriptive and one association parameter for three different scales of the SF-36. For all item non-response rates and types of missing data, multiple imputation and full information maximum likelihood appeared superior to the personal mean score and especially to hot deck in terms of accuracy and precision; however, the use of personal mean score was associated with insignificant bias (relative bias personal mean score appears nonetheless appropriate for dealing with items missing from completed SF-36 questionnaires in most situations of routine use. These results can reasonably be extended to other questionnaires constructed according to classical test theory.

  3. The Rectal Cancer Female Sexuality Score

    DEFF Research Database (Denmark)

    Thyø, Anne; Emmertsen, Katrine J; Laurberg, Søren

    2018-01-01

    BACKGROUND: Sexual dysfunction and impaired quality of life is a potential side effect to rectal cancer treatment. OBJECTIVE: The objective of this study was to develop and validate a simple scoring system intended to evaluate sexual function in women treated for rectal cancer. DESIGN......: This is a population-based cross-sectional study. SETTINGS: Female patients diagnosed with rectal cancer between 2001 and 2014 were identified by using the Danish Colorectal Cancer Group's database. Participants filled in the validated Sexual Function Vaginal Changes questionnaire. Women declared to be sexually active...... in the validation group. PATIENTS: Female patients with rectal cancer above the age of 18 who underwent abdominoperineal resection, Hartmann procedure, or total/partial mesorectal excision were selected. MAIN OUTCOME MEASURES: The primary outcome measured was the quality of life that was negatively affected because...

  4. Wearable PPG sensor based alertness scoring system.

    Science.gov (United States)

    Dey, Jishnu; Bhowmik, Tanmoy; Sahoo, Saswata; Tiwari, Vijay Narayan

    2017-07-01

    Quantifying mental alertness in today's world is important as it enables the person to adopt lifestyle changes for better work efficiency. Miniaturized sensors in wearable devices have facilitated detection/monitoring of mental alertness. Photoplethysmography (PPG) sensors through Heart Rate Variability (HRV) offer one such opportunity by providing information about one's daily alertness levels without requiring any manual interference from the user. In this paper, a smartwatch based alertness estimation system is proposed. Data collected from PPG sensor of smartwatch is processed and fed to machine learning based model to get a continuous alertness score. Utility functions are designed based on statistical analysis to give a quality score on different stages of alertness such as awake, long sleep and short duration power nap. An intelligent data collection approach is proposed in collaboration with the motion sensor in the smartwatch to reduce battery drainage. Overall, our proposed wearable based system provides a detailed analysis of alertness over a period in a systematic and optimized manner. We were able to achieve an accuracy of 80.1% for sleep/awake classification along with alertness score. This opens up the possibility for quantifying alertness levels using a single PPG sensor for better management of health related activities including sleep.

  5. A Force Balanced Fragmentation Method for ab Initio Molecular Dynamic Simulation of Protein

    Directory of Open Access Journals (Sweden)

    Mingyuan Xu

    2018-05-01

    Full Text Available A force balanced generalized molecular fractionation with conjugate caps (FB-GMFCC method is proposed for ab initio molecular dynamic simulation of proteins. In this approach, the energy of the protein is computed by a linear combination of the QM energies of individual residues and molecular fragments that account for the two-body interaction of hydrogen bond between backbone peptides. The atomic forces on the caped H atoms were corrected to conserve the total force of the protein. Using this approach, ab initio molecular dynamic simulation of an Ace-(ALA9-NME linear peptide showed the conservation of the total energy of the system throughout the simulation. Further a more robust 110 ps ab initio molecular dynamic simulation was performed for a protein with 56 residues and 862 atoms in explicit water. Compared with the classical force field, the ab initio molecular dynamic simulations gave better description of the geometry of peptide bonds. Although further development is still needed, the current approach is highly efficient, trivially parallel, and can be applied to ab initio molecular dynamic simulation study of large proteins.

  6. AN AB INITIO MODEL FOR COSMIC-RAY MODULATION

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N. E.; Burger, R. A. [Center for Space Research, North-West University, Potchefstroom 2520 (South Africa)

    2013-07-20

    A proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays (CRs) is of vital importance for a better understanding of CR modulation in the heliosphere. This study presents an ab initio model for CR modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for solar minimum heliospheric conditions, utilizing boundary values chosen so that model results are in reasonable agreement with spacecraft observations of turbulence quantities in the solar ecliptic plane and along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modeled slab and two-dimensional (2D) turbulence energy spectra. The modeled 2D spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers. There currently exist no models or observations for the wavenumber where this drop-off occurs, and it is considered to be the only free parameter in this study. The modeled spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on CR drifts are modeled in a self-consistent way, also employing a recently developed model for wavy current sheet drift. The resulting diffusion and drift coefficients are applied to the study of galactic CR protons and antiprotons using a 3D, steady-state CR modulation code, and sample solutions in fair to good agreement with multiple spacecraft observations are presented.

  7. Cosmic-ray modulation: an ab initio approach

    Energy Technology Data Exchange (ETDEWEB)

    Engelbrecht, N.E.; Burger, R.A., E-mail: 12580996@nwu.ac.za [Center for Space Research, North-West University, Potchefstroom (South Africa)

    2014-07-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  8. Cosmic-ray modulation: an ab initio approach

    International Nuclear Information System (INIS)

    Engelbrecht, N.E.; Burger, R.A.

    2014-01-01

    A better understanding of cosmic-ray modulation in the heliosphere can only be gained through a proper understanding of the effects of turbulence on the diffusion and drift of cosmic rays. We present an ab initio model for cosmic-ray modulation, incorporating for the first time the results yielded by a two-component turbulence transport model. This model is solved for periods of minimum solar activity, utilizing boundary values chosen so that model results are in fair to good agreement with spacecraft observations of turbulence quantities, not only in the solar ecliptic plane but also along the out-of-ecliptic trajectory of the Ulysses spacecraft. These results are employed as inputs for modelled slab and 2D turbulence energy spectra. The latter spectrum is chosen based on physical considerations, with a drop-off at the very lowest wavenumbers commencing at the 2D outerscale. There currently exist no models or observations for this quantity, and it is the only free parameter in this study. The modelled turbulence spectra are used as inputs for parallel mean free path expressions based on those derived from quasi-linear theory and perpendicular mean free paths from extended nonlinear guiding center theory. Furthermore, the effects of turbulence on cosmic-ray drifts are modelled in a self-consistent way, employing a recently developed model for drift along the wavy current sheet. The resulting diffusion coefficients and drift expressions are applied to the study of galactic cosmic-ray protons and antiprotons using a three dimensional, steady-state cosmic-ray modulation code, and sample solutions in fair agreement with multiple spacecraft observations are presented. (author)

  9. Lithium Insertion In Silicon Nanowires: An ab Initio Study

    KAUST Repository

    Zhang, Qianfan

    2010-09-08

    The ultrahigh specific lithium ion storage capacity of Si nanowires (SiNWs) has been demonstrated recently and has opened up exciting opportunities for energy storage. However, a systematic theoretical study on lithium insertion in SiNWs remains a challenge, and as a result, understanding of the fundamental interaction and microscopic dynamics during lithium insertion is still lacking. This paper focuses on the study of single Li atom insertion into SiNWs with different sizes and axis orientations by using full ab initio calculations. We show that the binding energy of interstitial Li increases as the SiNW diameter grows. The binding energies at different insertion sites, which can be classified as surface, intermediate, and core sites, are quite different. We find that surface sites are energetically the most favorable insertion positions and that intermediate sites are the most unfavorable insertion positions. Compared with the other growth directions, the [110] SiNWs with different diameters always present the highest binding energies on various insertion locations, which indicates that [110] SiNWs are more favorable by Li doping. Furthermore, we study Li diffusion inside SiNWs. The results show that the Li surface diffusion has a much higher chance to occur than the surface to core diffusion, which is consistent with the experimental observation that the Li insertion in SiNWs is layer by layer from surface to inner region. After overcoming a large barrier crossing surface-to-intermediate region, the diffusion toward center has a higher possibility to occur than the inverse process. © 2010 American Chemical Society.

  10. An ab initio study of plutonium oxides surfaces

    International Nuclear Information System (INIS)

    Jomard, G.; Bottin, F.; Amadon, B.

    2007-01-01

    By means of first-principles calculations, we have studied the atomic structure as well as the thermodynamic stability of various plutonium dioxide surfaces in function of their environment (in terms of oxygen partial pressure and temperature). All these simulations have been performed with the ABINIT code. It is well known that DFT fails to describe correctly plutonium-based materials since 5f electrons in such systems are strongly correlated. In order to go beyond DFT, we have treated PuO 2 and β-Pu 2 O 3 in a DFT+U framework. We show that the couple of parameters (U,J) that works well for pure Pu is also well designed for describing ground state (GS) properties of these two oxides. The major improvement with respect with DFT is that we are able to predict an insulating GS in agreement with experiments. The presence of a gap in the DOS (Density of States) of plutonium oxides should play a significant role in the predicted surface reactivity. However, performing DFT+U calculations on surfaces of plutonium oxide from scratch was too ambitious. That is why we decided, as a first step, to study the stability of the (100), (110) and (111) surfaces of PuO 2 in a DFT-GGA framework. For each of these orientations, we considered various terminations. These ab initio results have been introduced in a thermodynamic model which allows us to predict the relative stability of the different terminations as a function of temperature and oxygen partial pressure (p O 2 ). We conclude that at room temperature and for p O 2 ∼10 atm., the polar O 2 -(100) termination is favoured. The stabilization of such a polar stoichiometric surface is surprising and should be confirmed by DFT+U calculations before any final conclusion. (authors)

  11. Skin scoring in systemic sclerosis

    DEFF Research Database (Denmark)

    Zachariae, Hugh; Bjerring, Peter; Halkier-Sørensen, Lars

    1994-01-01

    Forty-one patients with systemic sclerosis were investigated with a new and simple skin score method measuring the degree of thickening and pliability in seven regions together with area involvement in each region. The highest values were, as expected, found in diffuse cutaneous systemic sclerosis...... (type III SS) and the lowest in limited cutaneous systemic sclerosis (type I SS) with no lesions extending above wrists and ancles. A positive correlation was found to the aminoterminal propeptide of type III procollagen, a serological marker for synthesis of type III collagen. The skin score...

  12. Ab initio study of the adducts of carbon monoxide with alkaline cations

    Science.gov (United States)

    Ferrari, A. M.; Ugliengo, P.; Garrone, E.

    1996-09-01

    The interaction between CO (either via the C or the O end) and the alkaline cations (Li+, Na+, K+, Rb+, and Cs+) has been studied by means of six ab initio methods, featuring the classical Hartree-Fock, the second order Møller-Plesset treatment of electron correlation, one local density functional and two gradient-corrected methods as well as a quadratic configuration interaction inclusive of single and double substitutions with a noniterative triples contribution to the energy. Basis sets adopted for CO, Li+, Na+, and K+ and the corresponding adducts are of triple-ζ valence quality augmented with a double set of polarization functions (d on C and O; p on the cations). For Rb+ and Cs+, Hay-Wadt effective core potential basis sets have been adopted. Calculated features are the binding energy, the frequency and intensity of the CO stretch, the bending mode, the cation-carbon (or oxygen) stretch, and the equilibrium geometry. Gradient-corrected density functional methods yield results nearly as good as the most expensive correlated method based on configurations interaction. A number of correlations are established among the observables. The role of electrostatics in the interaction is analyzed both by studying the molecular electrostatic potential of CO and by replacing the cation with a proton in the same position. Binding through the C end is invariably preferred, though, with increasing size of the cation, binding through the O end become progressively less unfavored. Experimental data concerning alkaline-cation substituted zeolites are compared with computational results, and an overall agreement is observed.

  13. A Scoring Tool for Websites – A Case of Sustainable Organizations

    Directory of Open Access Journals (Sweden)

    Ahmed GOMAA

    2014-06-01

    Full Text Available This paper introduces a scoring tool to analyse company sustainability marketing efforts. We identify the expected scores for the companies selected on Corporate Responsibility Magazine’s list of 100 Best Corporate Citizens of the year. The scoring tool is based on the aspects of sustainability and website quality and is divided into three categories: a user friendly, b transparency, and c content. The automation of the scoring tool benefits from a sustainability taxonomy to extract and evaluate the sustainability concepts and efforts mentioned by the companies. The tool scores the selected companies websites to determine the extent and quality of a company’s marketing of sustainability efforts. The result of applying the scoring tool shows that all companies in the list scored 8 to 14 in the user friendly section. In the transparency section, they scored 5 to 7, and in the content section they scored 6 to 10.

  14. Severity scoring in the critically ill: part 2: maximizing value from outcome prediction scoring systems.

    Science.gov (United States)

    Breslow, Michael J; Badawi, Omar

    2012-02-01

    Part 2 of this review of ICU scoring systems examines how scoring system data should be used to assess ICU performance. There often are two different consumers of these data: lCU clinicians and quality leaders who seek to identify opportunities to improve quality of care and operational efficiency, and regulators, payors, and consumers who want to compare performance across facilities. The former need to know how to garner maximal insight into their care practices; this includes understanding how length of stay (LOS) relates to quality, analyzing the behavior of different subpopulations, and following trends over time. Segregating patients into low-, medium-, and high-risk populations is especially helpful, because care issues and outcomes may differ across this severity continuum. Also, LOS behaves paradoxically in high-risk patients (survivors often have longer LOS than nonsurvivors); failure to examine this subgroup separately can penalize ICUs with superior outcomes. Consumers of benchmarking data often focus on a single score, the standardized mortality ratio (SMR). However, simple SMRs are disproportionately affected by outcomes in high-risk patients, and differences in population composition, even when performance is otherwise identical, can result in different SMRs. Future benchmarking must incorporate strategies to adjust for differences in population composition and report performance separately for low-, medium- and high-acuity patients. Moreover, because many ICUs lack the resources to care for high-acuity patients (predicted mortality >50%), decisions about where patients should receive care must consider both ICU performance scores and their capacity to care for different types of patients.

  15. Many-body optimization using an ab initio monte carlo method.

    Science.gov (United States)

    Haubein, Ned C; McMillan, Scott A; Broadbelt, Linda J

    2003-01-01

    Advances in computing power have made it possible to study solvated molecules using ab initio quantum chemistry. Inclusion of discrete solvent molecules is required to determine geometric information about solute/solvent clusters. Monte Carlo methods are well suited to finding minima in many-body systems, and ab initio methods are applicable to the widest range of systems. A first principles Monte Carlo (FPMC) method was developed to find minima in many-body systems, and emphasis was placed on implementing moves that increase the likelihood of finding minimum energy structures. Partial optimization and molecular interchange moves aid in finding minima and overcome the incomplete sampling that is unavoidable when using ab initio methods. FPMC was validated by studying the boron trifluoride-water system, and then the method was used to examine the methyl carbenium ion in water to demonstrate its application to solvation problems.

  16. Ab-initio calculations of superconducting properties of YBa2Cu3O7

    International Nuclear Information System (INIS)

    Zhao, G.L.; Bagayoko, D.

    1999-01-01

    The authors present ab-initio calculations for the electronic structure and superconducting properties of YBa 2 Cu 3 O 7 (YBCO). The electronic structure was calculated using a self-consistent ab-initio LCAO method. They solved the anisotropic Eliashberg gap equation numerically. The strong coupling of the high energy optical phonons around 60--73 meV, with the electrons at the Fermi surface, leads to a high Tc in YBCO. The calculated Tc is about 89 K for μ* = 0.1. The good agreement of the calculated results with experimental measurements and the ab-initio nature of the calculations support the scenario of an anisotropic s-wave superconductor for YBCO

  17. Inelastic neutron scattering an ab-initio calculation of negative thermal expansion in Ag2O

    International Nuclear Information System (INIS)

    Gupta, M.K.; Mittal, R.; Rols, S.; Chaplot, S.L.

    2012-01-01

    The compound Ag 2 O undergoes large and isotropic negative thermal expansion over 0-500 K. We report temperature dependent inelastic neutron scattering measurements and ab-initio calculations of the phonon spectrum. The temperature dependence of the experimental phonon spectrum shows strong anharmonic nature of phonon modes of energy around 2.4 meV. The ab-initio calculations reveal that the maximum negative Grüneisen parameter, which is a measure of the relevant anharmonicity, occurs for the transverse phonon modes that involve bending motions of the Ag 4 O tetrahedra. The thermal expansion is evaluated from the ab-initio calculation of the pressure dependence of the phonon modes, and found in good agreement with available experimental data.

  18. Ab initio calculations of 3H(d,n)4He fusion

    International Nuclear Information System (INIS)

    Navratil, Petr; Quaglioni, Sofia

    2012-01-01

    We build a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the ab initio no-core shell model. In this way, we complement a microscopic-cluster technique with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. We will present the first results of the d- 3 H and d- 3 He fusion calculation obtained within our ab initio approach. We will also discuss our d- 4 He, 3 H- 4 He and 3 H- 3 H scattering calculations and the outline of the extension of the formalism to include three-cluster final states with the goal to calculate the 3 H( 3 H,2n) 4 He cross section

  19. Shear stiffness in nanolaminar Ti3SiC2 challenges ab initio calculations

    International Nuclear Information System (INIS)

    Kisi, E H; Zhang, J F; Kirstein, O; Riley, D P; Styles, M J; Paradowska, A M

    2010-01-01

    Nanolaminates such as the M n+1 AX n (MAX) phases are a material class with ab initio derived elasticity tensors published for over 250 compounds. We have for the first time experimentally determined the full elasticity tensor of the archetype MAX phase, Ti 3 SiC 2 , using polycrystalline samples and in situ neutron diffraction. The experimental elastic constants show extreme shear stiffness, with c 44 more than five times greater than expected for an isotropic material. Such shear stiffness is quite rare in hexagonal materials and strongly contradicts the predictions of all published MAX phase elastic constants derived from ab initio calculations. It is concluded that second order properties such as elastic moduli derived from ab initio calculations require careful experimental verification. The diffraction technique used currently provides the only method of verification for the elasticity tensor for the majority of new materials where single crystals are not available. (fast track communication)

  20. Ab initio/interpolated quantum dynamics on coupled electronic states with full configuration interaction wave functions

    International Nuclear Information System (INIS)

    Thompson, K.; Martinez, T.J.

    1999-01-01

    We present a new approach to first-principles molecular dynamics that combines a general and flexible interpolation method with ab initio evaluation of the potential energy surface. This hybrid approach extends significantly the domain of applicability of ab initio molecular dynamics. Use of interpolation significantly reduces the computational effort associated with the dynamics over most of the time scale of interest, while regions where potential energy surfaces are difficult to interpolate, for example near conical intersections, are treated by direct solution of the electronic Schroedinger equation during the dynamics. We demonstrate the concept through application to the nonadiabatic dynamics of collisional electronic quenching of Li(2p). Full configuration interaction is used to describe the wave functions of the ground and excited electronic states. The hybrid approach agrees well with full ab initio multiple spawning dynamics, while being more than an order of magnitude faster. copyright 1999 American Institute of Physics

  1. Exploring the speed and performance of molecular replacement with AMPLE using QUARK ab initio protein models

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, Ronan M. [STFC Rutherford Appleton Laboratory, Didcot OX11 0FA (United Kingdom); Bibby, Jaclyn; Thomas, Jens [University of Liverpool, Liverpool L69 7ZB (United Kingdom); Xu, Dong [Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037 (United States); Zhang, Yang [University of Michigan, Ann Arbor, MI 48109 (United States); Mayans, Olga [University of Liverpool, Liverpool L69 7ZB (United Kingdom); Winn, Martyn D. [Science and Technology Facilities Council Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Rigden, Daniel J., E-mail: drigden@liv.ac.uk [University of Liverpool, Liverpool L69 7ZB (United Kingdom); STFC Rutherford Appleton Laboratory, Didcot OX11 0FA (United Kingdom)

    2015-02-01

    Two ab initio modelling programs solve complementary sets of targets, enhancing the success of AMPLE with small proteins. AMPLE clusters and truncates ab initio protein structure predictions, producing search models for molecular replacement. Here, an interesting degree of complementarity is shown between targets solved using the different ab initio modelling programs QUARK and ROSETTA. Search models derived from either program collectively solve almost all of the all-helical targets in the test set. Initial solutions produced by Phaser after only 5 min perform surprisingly well, improving the prospects for in situ structure solution by AMPLE during synchrotron visits. Taken together, the results show the potential for AMPLE to run more quickly and successfully solve more targets than previously suspected.

  2. Virtual synthesis of crystals using ab initio MD: Case study on LiFePO4

    Science.gov (United States)

    Mishra, S. B.; Nanda, B. R. K.

    2017-05-01

    Molecular dynamics simulation technique is fairly successful in studying the structural aspects and dynamics of fluids. Here we study the ability of ab initio molecular dynamics (ab initio MD) to carry out virtual experiments to synthesize new crystalline materials and to predict their structures. For this purpose the olivine phosphate LiFePO4 (LFPO) is used as an example. As transition metal oxides in general are stabilized with layered geometry, we carried out ab initio MD simulations over a hypothetical layered configuration consisting of alternate LiPO2 and FeO2 layers. With intermittent steps of electron minimization, the resulted equilibrium lattice consist of PO4 tetrahedra and distorted Fe-O complexes similar to the one observed in the experimental lattice.

  3. The persistence of depression score

    NARCIS (Netherlands)

    Spijker, J.; de Graaf, R.; Ormel, J.; Nolen, W. A.; Grobbee, D. E.; Burger, H.

    2006-01-01

    Objective: To construct a score that allows prediction of major depressive episode (MDE) persistence in individuals with MDE using determinants of persistence identified in previous research. Method: Data were derived from 250 subjects from the general population with new MDE according to DSM-III-R.

  4. Score distributions in information retrieval

    NARCIS (Netherlands)

    Arampatzis, A.; Robertson, S.; Kamps, J.

    2009-01-01

    We review the history of modeling score distributions, focusing on the mixture of normal-exponential by investigating the theoretical as well as the empirical evidence supporting its use. We discuss previously suggested conditions which valid binary mixture models should satisfy, such as the

  5. Developing Scoring Algorithms (Earlier Methods)

    Science.gov (United States)

    We developed scoring procedures to convert screener responses to estimates of individual dietary intake for fruits and vegetables, dairy, added sugars, whole grains, fiber, and calcium using the What We Eat in America 24-hour dietary recall data from the 2003-2006 NHANES.

  6. A simplified score to quantify comorbidity in COPD.

    Directory of Open Access Journals (Sweden)

    Nirupama Putcha

    Full Text Available Comorbidities are common in COPD, but quantifying their burden is difficult. Currently there is a COPD-specific comorbidity index to predict mortality and another to predict general quality of life. We sought to develop and validate a COPD-specific comorbidity score that reflects comorbidity burden on patient-centered outcomes.Using the COPDGene study (GOLD II-IV COPD, we developed comorbidity scores to describe patient-centered outcomes employing three techniques: 1 simple count, 2 weighted score, and 3 weighted score based upon statistical selection procedure. We tested associations, area under the Curve (AUC and calibration statistics to validate scores internally with outcomes of respiratory disease-specific quality of life (St. George's Respiratory Questionnaire, SGRQ, six minute walk distance (6MWD, modified Medical Research Council (mMRC dyspnea score and exacerbation risk, ultimately choosing one score for external validation in SPIROMICS.Associations between comorbidities and all outcomes were comparable across the three scores. All scores added predictive ability to models including age, gender, race, current smoking status, pack-years smoked and FEV1 (p<0.001 for all comparisons. Area under the curve (AUC was similar between all three scores across outcomes: SGRQ (range 0·7624-0·7676, MMRC (0·7590-0·7644, 6MWD (0·7531-0·7560 and exacerbation risk (0·6831-0·6919. Because of similar performance, the comorbidity count was used for external validation. In the SPIROMICS cohort, the comorbidity count performed well to predict SGRQ (AUC 0·7891, MMRC (AUC 0·7611, 6MWD (AUC 0·7086, and exacerbation risk (AUC 0·7341.Quantifying comorbidity provides a more thorough understanding of the risk for patient-centered outcomes in COPD. A comorbidity count performs well to quantify comorbidity in a diverse population with COPD.

  7. Identification of male factor infertility using a novel semen quality score and reactive oxygen species levels Identificação de pacientes portadores do fator de infertilidade masculina através do cálculo de um novo escore de qualidade de sêmen e pela medida de espécies reativas de oxigênio

    Directory of Open Access Journals (Sweden)

    Kiran P. Nallella

    2005-08-01

    Full Text Available PURPOSE: To determine whether patients with male factor infertility can be accurately identified by calculating a novel semen quality score and measuring levels of reactive oxygen species during routine infertility screening. METHODS: Semen samples from 133 patients and 91 healthy donors were evaluated with manual and computer-assisted semen analysis. A principal component analysis model was employed to calculate a semen quality score. In brief, this score was calculated by base 10 logarithms multiplied by varying weights given to 9 sperm parameters. Reactive oxygen species levels were measured using chemiluminescence assay. RESULTS: The semen quality score had a sensitivity of 80.45% and accuracy of 77% at a cutoff of 93.1 in identifying patients with male factor infertility. The area under the receiver operating characteristic curves for the semen quality score was 84.28% (95% CI: 65.22%-100%. Reactive oxygen species levels [log10 (reactive oxygen species +1] were significantly higher in male factor infertility patients. Reactive oxygen species had a sensitivity of 83.47% and specificity of 60.52% with an accuracy of 75% at a cutoff of 1.25 in identifying male factor infertility patients. The area under the receiver operating characteristic curve for reactive oxygen species levels was 78.92% (95% CI: 72.60%-85.23%. semen quality scores were significantly and negatively correlated with reactive oxygen species levels in the donors and the male factor infertility patients. CONCLUSIONS: The semen quality score and reactive oxygen species levels in semen samples appear to be strongly associated with male factor infertility. Because both of these parameters are more sensitive than individual sperm parameters in identifying male factor infertility, they should be included in routine infertility screening.OBJETIVO: Determinar se pacientes portadores do fator de infertilidade masculina podem ser precisamente identificados através do cálculo de um

  8. An ab initio study of plutonium oxides surfaces; Etude ab initio des surfaces d'oxydes de Pu

    Energy Technology Data Exchange (ETDEWEB)

    Jomard, G.; Bottin, F.; Amadon, B

    2007-07-01

    By means of first-principles calculations, we have studied the atomic structure as well as the thermodynamic stability of various plutonium dioxide surfaces in function of their environment (in terms of oxygen partial pressure and temperature). All these simulations have been performed with the ABINIT code. It is well known that DFT fails to describe correctly plutonium-based materials since 5f electrons in such systems are strongly correlated. In order to go beyond DFT, we have treated PuO{sub 2} and {beta}-Pu{sub 2}O{sub 3} in a DFT+U framework. We show that the couple of parameters (U,J) that works well for pure Pu is also well designed for describing ground state (GS) properties of these two oxides. The major improvement with respect with DFT is that we are able to predict an insulating GS in agreement with experiments. The presence of a gap in the DOS (Density of States) of plutonium oxides should play a significant role in the predicted surface reactivity. However, performing DFT+U calculations on surfaces of plutonium oxide from scratch was too ambitious. That is why we decided, as a first step, to study the stability of the (100), (110) and (111) surfaces of PuO{sub 2} in a DFT-GGA framework. For each of these orientations, we considered various terminations. These ab initio results have been introduced in a thermodynamic model which allows us to predict the relative stability of the different terminations as a function of temperature and oxygen partial pressure (p{sub O{sub 2}}). We conclude that at room temperature and for p{sub O{sub 2}}{approx}10 atm., the polar O{sub 2}-(100) termination is favoured. The stabilization of such a polar stoichiometric surface is surprising and should be confirmed by DFT+U calculations before any final conclusion. (authors)

  9. Ab Initio Calculations and Raman and SERS Spectral Analyses of Amphetamine Species

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nørbygaard, Thomas; White, Peter C.

    2011-01-01

    For the first time, the differences between the spectra of amphetamine and amphetamine-H+ and between different conformers are thoroughly studied by ab initio model calculations, and Raman and surface-enhanced Raman spectroscopy (SERS) spectra are measured for different species of amphetamine....... The spectra of amphetamine and amphetamine-H+ sampleswere obtained and assigned according to a comparison of the experimental spectra and the ab initio MO calculations, performed using the Gaussian 03W program (Gaussian, Inc., Pittsburgh, PA). The analyses were based on complete geometry minimization...

  10. Exploring the ab initio/classical free energy perturbation method: The hydration free energy of water

    International Nuclear Information System (INIS)

    Sakane, Shinichi; Yezdimer, Eric M.; Liu, Wenbin; Barriocanal, Jose A.; Doren, Douglas J.; Wood, Robert H.

    2000-01-01

    The ab initio/classical free energy perturbation (ABC-FEP) method proposed previously by Wood et al. [J. Chem. Phys. 110, 1329 (1999)] uses classical simulations to calculate solvation free energies within an empirical potential model, then applies free energy perturbation theory to determine the effect of changing the empirical solute-solvent interactions to corresponding interactions calculated from ab initio methods. This approach allows accurate calculation of solvation free energies using an atomistic description of the solvent and solute, with interactions calculated from first principles. Results can be obtained at a feasible computational cost without making use of approximations such as a continuum solvent or an empirical cavity formation energy. As such, the method can be used far from ambient conditions, where the empirical parameters needed for approximate theories of solvation may not be available. The sources of error in the ABC-FEP method are the approximations in the ab initio method, the finite sample of configurations, and the classical solvent model. This article explores the accuracy of various approximations used in the ABC-FEP method by comparing to the experimentally well-known free energy of hydration of water at two state points (ambient conditions, and 973.15 K and 600 kg/m3). The TIP4P-FQ model [J. Chem. Phys. 101, 6141 (1994)] is found to be a reliable solvent model for use with this method, even at supercritical conditions. Results depend strongly on the ab initio method used: a gradient-corrected density functional theory is not adequate, but a localized MP2 method yields excellent agreement with experiment. Computational costs are reduced by using a cluster approximation, in which ab initio pair interaction energies are calculated between the solute and up to 60 solvent molecules, while multi-body interactions are calculated with only a small cluster (5 to 12 solvent molecules). Sampling errors for the ab initio contribution to

  11. Atomic carbon chains as spin-transmitters: An ab initio transport study

    DEFF Research Database (Denmark)

    Fürst, Joachim Alexander; Brandbyge, Mads; Jauho, Antti-Pekka

    2010-01-01

    An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin-polarization of the transmi......An atomic carbon chain joining two graphene flakes was recently realized in a ground-breaking experiment by Jin et al. (Phys. Rev. Lett., 102 (2009) 205501). We present ab initio results for the electron transport properties of such chains and demonstrate complete spin...

  12. Studies of urea geometry by means of ab initio methods and computer simulations of liquids

    OpenAIRE

    Cirino, José Jair Vianna; Bertran, Celso Aparecido

    2002-01-01

    A study was carried out on the urea geometries using ab initio calculation and Monte Carlo computational simulation of liquids. The ab initio calculated results showed that urea has a non-planar conformation in the gas phase in which the hydrogen atoms are out of the plane formed by the heavy atoms. Free energies associated to the rotation of the amino groups of urea in water were obtained using the Monte Carlo method in which the thermodynamic perturbation theory is implemented. The magnitud...

  13. Ab initio study of H + + H 2 collisions: Elastic/inelastic and charge transfer processes

    Science.gov (United States)

    Saieswari, A.; Kumar, Sanjay

    2007-12-01

    An ab initio full configuration interaction study has been undertaken to obtain the global potential energy surfaces for the ground and the first excited electronic state of the H + + H 2 system employing Dunning's cc-pVQZ basis set. Using the ab initio approach the corresponding quasi-diabatic potential energy surfaces and coupling potentials have been obtained. A time-independent quantum mechanical study has been also undertaken for both the inelastic and charge transfer processes at the experimental collision energy Ec.m. = 20.0 eV and the preliminary results show better agreement with the experimental data as compared to the earlier available theoretical studies.

  14. Evaluation of a nutrient-rich food index score in the Netherlands

    NARCIS (Netherlands)

    Sluik, D.; Streppel, M.T.; Lee, van L.; Geelen, A.; Feskens, E.J.M.

    2015-01-01

    Nutrient-rich food (NRF) index scores are dietary quality indices based on nutrient density. We studied the design aspects involved in the development and validation of NRF index scores, using the Dutch consumption data and guidelines as an example. We evaluated fifteen NRF index scores against the

  15. Is HO3 minimum cis or trans? An analytic full-dimensional ab initio isomerization path.

    Science.gov (United States)

    Varandas, A J C

    2011-05-28

    The minimum energy path for isomerization of HO(3) has been explored in detail using accurate high-level ab initio methods and techniques for extrapolation to the complete basis set limit. In agreement with other reports, the best estimates from both valence-only and all-electron single-reference methods here utilized predict the minimum of the cis-HO(3) isomer to be deeper than the trans-HO(3) one. They also show that the energy varies by less than 1 kcal mol(-1) or so over the full isomerization path. A similar result is found from valence-only multireference configuration interaction calculations with the size-extensive Davidson correction and a correlation consistent triple-zeta basis, which predict the energy difference between the two isomers to be of only Δ = -0.1 kcal mol(-1). However, single-point multireference calculations carried out at the optimum triple-zeta geometry with basis sets of the correlation consistent family but cardinal numbers up to X = 6 lead upon a dual-level extrapolation to the complete basis set limit of Δ = (0.12 ± 0.05) kcal mol(-1). In turn, extrapolations with the all-electron single-reference coupled-cluster method including the perturbative triples correction yield values of Δ = -0.19 and -0.03 kcal mol(-1) when done from triple-quadruple and quadruple-quintuple zeta pairs with two basis sets of increasing quality, namely cc-cpVXZ and aug-cc-pVXZ. Yet, if added a value of 0.25 kcal mol(-1) that accounts for the effect of triple and perturbative quadruple excitations with the VTZ basis set, one obtains a coupled cluster estimate of Δ = (0.14 ± 0.08) kcal mol(-1). It is then shown for the first time from systematic ab initio calculations that the trans-HO(3) isomer is more stable than the cis one, in agreement with the available experimental evidence. Inclusion of the best reported zero-point energy difference (0.382 kcal mol(-1)) from multireference configuration interaction calculations enhances further the relative

  16. Modelling of nuclear glasses by classical and ab initio molecular dynamics; Modelisation de verres intervenant dans le conditionnement des dechets radioactifs par dynamiques moleculaires classique et ab initio

    Energy Technology Data Exchange (ETDEWEB)

    Ganster, P

    2004-10-15

    A calcium aluminosilicate glass of molar composition 67 % SiO{sub 2} - 12 % Al{sub 2}O{sub 3} - 21 % CaO was modelled by classical and ab initio molecular dynamics. The size effect study in classical MD shows that the systems of 100 atoms are more ordered than the larger ones. These effects are mainly due to the 3-body terms in the empirical potentials. Nevertheless, these effects are small and the structures generated are in agreement with experimental data. In such kind of glass, we denote an aluminium avoidance and an excess of non bridging oxygens which can be compensated by tri coordinated oxygens. When the dynamics of systems of 100 and 200 atoms is followed by ab initio MD, some local arrangements occurs (bond length, angular distributions). Thus, more realistic vibrational properties are obtained in ab initio MD. The modelling of thin films shows that aluminium atoms extend to the most external part of the surface and they are all tri-coordinated. Calcium atoms are set in the sub layer part of the surface and they produce a depolymerization of the network. In classical MD, tri-coordinated aluminium atoms produce an important electric field above the surface. With non bridging oxygens, they constitute attractive sites for single water molecules. (author)

  17. Combining Teacher Assessment Scores with External Examination ...

    African Journals Online (AJOL)

    Combining Teacher Assessment Scores with External Examination Scores for Certification: Comparative Study of Four Statistical Models. ... University entrance examination scores in mathematics were obtained for a subsample of 115 ...

  18. Scoring System Improvements to Three Leadership Predictors

    National Research Council Canada - National Science Library

    Dela

    1997-01-01

    .... The modified scoring systems were evaluated by rescoring responses randomly selected from the sample which had been scored according to the scoring systems originally developed for the leadership research...

  19. Interpreting force concept inventory scores: Normalized gain and SAT scores

    Directory of Open Access Journals (Sweden)

    Jeffrey J. Steinert

    2007-05-01

    Full Text Available Preinstruction SAT scores and normalized gains (G on the force concept inventory (FCI were examined for individual students in interactive engagement (IE courses in introductory mechanics at one high school (N=335 and one university (N=292 , and strong, positive correlations were found for both populations ( r=0.57 and r=0.46 , respectively. These correlations are likely due to the importance of cognitive skills and abstract reasoning in learning physics. The larger correlation coefficient for the high school population may be a result of the much shorter time interval between taking the SAT and studying mechanics, because the SAT may provide a more current measure of abilities when high school students begin the study of mechanics than it does for college students, who begin mechanics years after the test is taken. In prior research a strong correlation between FCI G and scores on Lawson’s Classroom Test of Scientific Reasoning for students from the same two schools was observed. Our results suggest that, when interpreting class average normalized FCI gains and comparing different classes, it is important to take into account the variation of students’ cognitive skills, as measured either by the SAT or by Lawson’s test. While Lawson’s test is not commonly given to students in most introductory mechanics courses, SAT scores provide a readily available alternative means of taking account of students’ reasoning abilities. Knowing the students’ cognitive level before instruction also allows one to alter instruction or to use an intervention designed to improve students’ cognitive level.

  20. Interpreting force concept inventory scores: Normalized gain and SAT scores

    Directory of Open Access Journals (Sweden)

    Vincent P. Coletta

    2007-05-01

    Full Text Available Preinstruction SAT scores and normalized gains (G on the force concept inventory (FCI were examined for individual students in interactive engagement (IE courses in introductory mechanics at one high school (N=335 and one university (N=292, and strong, positive correlations were found for both populations (r=0.57 and r=0.46, respectively. These correlations are likely due to the importance of cognitive skills and abstract reasoning in learning physics. The larger correlation coefficient for the high school population may be a result of the much shorter time interval between taking the SAT and studying mechanics, because the SAT may provide a more current measure of abilities when high school students begin the study of mechanics than it does for college students, who begin mechanics years after the test is taken. In prior research a strong correlation between FCI G and scores on Lawson’s Classroom Test of Scientific Reasoning for students from the same two schools was observed. Our results suggest that, when interpreting class average normalized FCI gains and comparing different classes, it is important to take into account the variation of students’ cognitive skills, as measured either by the SAT or by Lawson’s test. While Lawson’s test is not commonly given to students in most introductory mechanics courses, SAT scores provide a readily available alternative means of taking account of students’ reasoning abilities. Knowing the students’ cognitive level before instruction also allows one to alter instruction or to use an intervention designed to improve students’ cognitive level.

  1. Estimating structure quality trends in the Protein Data Bank by equivalent resolution.

    Science.gov (United States)

    Bagaria, Anurag; Jaravine, Victor; Güntert, Peter

    2013-10-01

    The quality of protein structures obtained by different experimental and ab-initio calculation methods varies considerably. The methods have been evolving over time by improving both experimental designs and computational techniques, and since the primary aim of these developments is the procurement of reliable and high-quality data, better techniques resulted on average in an evolution toward higher quality structures in the Protein Data Bank (PDB). Each method leaves a specific quantitative and qualitative "trace" in the PDB entry. Certain information relevant to one method (e.g. dynamics for NMR) may be lacking for another method. Furthermore, some standard measures of quality for one method cannot be calculated for other experimental methods, e.g. crystal resolution or NMR bundle RMSD. Consequently, structures are classified in the PDB by the method used. Here we introduce a method to estimate a measure of equivalent X-ray resolution (e-resolution), expressed in units of Å, to assess the quality of any type of monomeric, single-chain protein structure, irrespective of the experimental structure determination method. We showed and compared the trends in the quality of structures in the Protein Data Bank over the last two decades for five different experimental techniques, excluding theoretical structure predictions. We observed that as new methods are introduced, they undergo a rapid method development evolution: within several years the e-resolution score becomes similar for structures obtained from the five methods and they improve from initially poor performance to acceptable quality, comparable with previously established methods, the performance of which is essentially stable. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Blind Grid Scoring Record No. 290

    National Research Council Canada - National Science Library

    Overbay, Larry; Robitaille, George

    2005-01-01

    ...) utilizing the APG Standardized UXO Technology Demonstration Site Blind Grid. Scoring Records have been coordinated by Larry Overbay and the Standardized UXO Technology Demonstration Site Scoring Committee...

  3. Blind Grid Scoring Record No. 293

    National Research Council Canada - National Science Library

    Overbay, Larry; Robitaille, George; Archiable, Robert; Fling, Rick; McClung, Christina

    2005-01-01

    ...) utilizing the YPG Standardized UXO Technology Demonstration Site Blind Grid. Scoring Records have been coordinated by Larry Overbay and the Standardized UXO Technology Demonstration Site Scoring Committee...

  4. Open Field Scoring Record No. 298

    National Research Council Canada - National Science Library

    Overbay, Jr., Larry; Robitaille, George; Fling, Rick; McClung, Christina

    2005-01-01

    ...) utilizing the APG Standardized UXO Technology Demonstration Site Open Field. Scoring Records have been coordinated by Larry Overbay and the Standardized UXO Technology Demonstration Site Scoring Committee...

  5. Open Field Scoring Record No. 299

    National Research Council Canada - National Science Library

    Overbay, Larry; Robitaille, George

    2005-01-01

    ...) utilizing the YPG Standardized UXO Technology Demonstration Site Open Field. Scoring Records have been coordinated by Larry Overbay and the standardized UXO Technology Demonstration Site Scoring Committee...

  6. Knee Injury and Osteoarthritis Outcome Score (KOOS)

    DEFF Research Database (Denmark)

    Collins, N J; Prinsen, C A C; Christensen, R

    2016-01-01

    OBJECTIVE: To conduct a systematic review and meta-analysis to synthesize evidence regarding measurement properties of the Knee injury and Osteoarthritis Outcome Score (KOOS). DESIGN: A comprehensive literature search identified 37 eligible papers evaluating KOOS measurement properties in partici......OBJECTIVE: To conduct a systematic review and meta-analysis to synthesize evidence regarding measurement properties of the Knee injury and Osteoarthritis Outcome Score (KOOS). DESIGN: A comprehensive literature search identified 37 eligible papers evaluating KOOS measurement properties...... in participants with knee injuries and/or osteoarthritis (OA). Methodological quality was evaluated using the COSMIN checklist. Where possible, meta-analysis of extracted data was conducted for all studies and stratified by age and knee condition; otherwise narrative synthesis was performed. RESULTS: KOOS has...... adequate internal consistency, test-retest reliability and construct validity in young and old adults with knee injuries and/or OA. The ADL subscale has better content validity for older patients and Sport/Rec for younger patients with knee injuries, while the Pain subscale is more relevant for painful...

  7. Study on the surface hydroxyl group on solid breeding materials by ab-initio calculations

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Satoru; Taniguchi, Masaki [Tokyo Univ. (Japan). Faculty of Engineering

    1996-10-01

    The nature of -OH on the surface of Li{sub 2}O was analyzed with the ab-initio quantum chemical calculation technique. Calculation results showed that the stretching vibration of O-H is affected by the chemical species around the -OH. (author)

  8. Understanding hydration of Zn(2+) in hydrothermal fluids with ab initio molecular dynamics

    NARCIS (Netherlands)

    Liu, X.; Lu, X.; Wang, R.; Meijer, E.J.

    2011-01-01

    With ab initio molecular dynamics simulations, the free-energy profiles of hydrated Zn2+ are calculated for both gaseous and aqueous systems from ambient to supercritical conditions, and from the derived free-energy information, the speciation of hydrated Zn2+ has been revealed. It is shown that the

  9. Sphinx: merging knowledge-based and ab initio approaches to improve protein loop prediction.

    Science.gov (United States)

    Marks, Claire; Nowak, Jaroslaw; Klostermann, Stefan; Georges, Guy; Dunbar, James; Shi, Jiye; Kelm, Sebastian; Deane, Charlotte M

    2017-05-01

    Loops are often vital for protein function, however, their irregular structures make them difficult to model accurately. Current loop modelling algorithms can mostly be divided into two categories: knowledge-based, where databases of fragments are searched to find suitable conformations and ab initio, where conformations are generated computationally. Existing knowledge-based methods only use fragments that are the same length as the target, even though loops of slightly different lengths may adopt similar conformations. Here, we present a novel method, Sphinx, which combines ab initio techniques with the potential extra structural information contained within loops of a different length to improve structure prediction. We show that Sphinx is able to generate high-accuracy predictions and decoy sets enriched with near-native loop conformations, performing better than the ab initio algorithm on which it is based. In addition, it is able to provide predictions for every target, unlike some knowledge-based methods. Sphinx can be used successfully for the difficult problem of antibody H3 prediction, outperforming RosettaAntibody, one of the leading H3-specific ab initio methods, both in accuracy and speed. Sphinx is available at http://opig.stats.ox.ac.uk/webapps/sphinx. deane@stats.ox.ac.uk. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.

  10. The Influence of Square Planar Platinum Complexes on DNA Bases Pairing. An ab initio DFT Study

    Czech Academy of Sciences Publication Activity Database

    Burda, J. V.; Šponer, Jiří; Leszczynski, J.

    2001-01-01

    Roč. 3, č. 19 (2001), s. 4404-4411 ISSN 1463-9076 R&D Projects: GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z4040901 Keywords : DNA base pairing * platinated base pairs * ab initio DFT study Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.787, year: 2001

  11. Ab initio Defect Energetics in LaBO3 Perovskite Solid Oxide Fuel Cell Materials

    DEFF Research Database (Denmark)

    Lee, Yueh-Lin; Morgan, Dane; Kleis, Jesper

    2009-01-01

    Perovskite materials of the form ABO3 are a promising family of compounds for use in solid oxide fuel cell (SOFC) cathodes. Study of the physics of these compounds under SOFC conditions with ab initio methods is particularly challenging due to high temperatures, exchange of oxygen with O2 gas...

  12. Ab initio molecular dynamics simulation of hydrogen fluoride at several thermodynamic states

    DEFF Research Database (Denmark)

    Kreitmeir, M.; Bertagnolli, H.; Mortensen, Jens Jørgen

    2003-01-01

    Liquid hydrogen fluoride is a simple but interesting system for studies of the influence of hydrogen bonds on physical properties. We have performed ab initio molecular dynamics simulations of HF at several thermodynamic states, where we examine the microscopic structure of the liquid as well...

  13. Ab initio Calculations of Charge Symmetry Breaking in the A=4 Hypernuclei

    Czech Academy of Sciences Publication Activity Database

    Gazda, Daniel; Gal, A.

    2016-01-01

    Roč. 116, č. 12 (2016), s. 122501 ISSN 0031-9007 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : ab initio * shell model * four-body calculations Subject RIV: BE - Theoretical Physics Impact factor: 8.462, year: 2016

  14. An Efficient Method for Electron-Atom Scattering Using Ab-initio Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Yang, Yonggang; Xiao, Liantuan; Jia, Suotang [Shanxi University, Taiyuan (China)

    2017-02-15

    We present an efficient method based on ab-initio calculations to investigate electron-atom scatterings. Those calculations profit from methods implemented in standard quantum chemistry programs. The new approach is applied to electron-helium scattering. The results are compared with experimental and other theoretical references to demonstrate the efficiency of our method.

  15. Ab initio theory of charge-carrier conduction in ultrapure organic crystals

    NARCIS (Netherlands)

    Hannewald, K.; Bobbert, P.A.

    2004-01-01

    We present an ab initio description of charge-carrier mobilities in organic molecular crystals of high purity. Our approach is based on Holstein's original concept of small-polaron bands but generalized with respect to the inclusion of nonlocal electron-phonon coupling. By means of an explicit

  16. Limitations of Ab Initio Predictions of Peptide Binding to MHC Class II Molecules

    DEFF Research Database (Denmark)

    Zhang, Hao; Lund, Ole; Nielsen, Morten

    2010-01-01

    potentials derived from the analysis of known protein structures; energetic evaluation of different peptide snapshots in a molecular dynamics simulation; and direct analysis of contacts made in known 3D structures of peptide:MHC complexes. These methods are ab initio in that they require structural data...

  17. The Pu–U–Am system: An ab initio informed CALPHAD thermodynamic study

    International Nuclear Information System (INIS)

    Perron, A.; Turchi, P.E.A.; Landa, A.; Söderlind, P.; Ravat, B.; Oudot, B.; Delaunay, F.

    2015-01-01

    Highlights: • The ab initio informed CALPHAD assessment of the Am–U system has been realized. • A strong tendency toward phase separation across the whole composition range is predicted. • The ab initio informed Pu–U–Am thermodynamic database has been developed. • The solubility of Am and U in the liquid phase is improved by adding Pu. • The δ-Pu (fcc) phase is strongly stabilized by Am, on the contrary to the bcc phase. - Abstract: Phase diagram and thermodynamic properties of the Am–U system, that are experimentally unknown, are calculated using the CALPHAD method with input from ab initio electronic-structure calculations for the fcc and bcc phases. A strong tendency toward phase separation across the whole composition range is predicted. In addition, ab initio informed Pu–U and Am–Pu thermodynamic assessments are combined to build a Pu–U–Am thermodynamic database. Regarding the Pu-rich corner of the ternary system, predictions indicate that Am acts as a powerful δ-Pu (fcc) stabilizer. In the U-rich corner, similar predictions are made but to a lesser extent. In both cases, the bcc phase is destabilized and the fcc phase is enhanced. Finally, results and methodology are discussed and compared with previous assessments and guidelines are provided for further experimental studies

  18. All electron ab initio investigations of the electronic states of the FeC molecule

    DEFF Research Database (Denmark)

    Shim, Irene; Gingerich, Karl A.

    1999-01-01

    The low lying electronic states of the molecule FeC have been investigated by performing all electron ab initio multi-configuration self-consistent-field (CASSCF) and multi reference configuration interaction (MRCI) calculations. The relativistic corrections for the one electron Darwin contact term...

  19. All Electron ab initio Investigations of the Electronic States of the MoN Molecule

    DEFF Research Database (Denmark)

    Shim, Irene; Gingerich, Karl A.

    1999-01-01

    The low lying electronic states of the molecule MoN have been investigated by performing all electron ab initio multi-configuration self-consistent-field (CASSCF) calculations. The relativistic corrections for the one electron Darwin contact term and the relativistic mass-velocity correction have...

  20. Ab initio I-V characteristics of short C-20 chains

    DEFF Research Database (Denmark)

    Roland, C.; Larade, B.; Taylor, Jeremy Philip

    2002-01-01

    We have calculated the I-V characteristics of short chains of C-20 molecular cages between Al and Au leads with an ab initio formalism. The results indicate that a linear chain of such molecules acts primarily as metallic nanowires. The transmission, however, depends sensitively both...

  1. Ab Initio Assessment of the Bonding in Disulfonates Containing Divalent Nitrogen and Phosphorus Atoms

    DEFF Research Database (Denmark)

    Andersen, Vinca Bonde; Berg, Rolf W.; Shim, Irene

    2017-01-01

    The iminodisulfonate, [N(SO3)2]3–, and phosphinodisulfonate, [P(SO3)2]3–, ions have been investigated by performing ab initio MP2/6-311+G**calculations. The nitrogen and phosphorus atoms as part of the ions are shown to be divalent with a negative charge and two lone pairs on the nitrogen...

  2. Raman Spectroscopy and Ab-Initio Model Calculations on Ionic Liquids

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2007-01-01

    spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C4mim][X]) salts. The rotational isomerism of the [C4mim]þ cation is described: the presence of anti...

  3. All-electron ab initio investigations of the electronic states of the NiC molecule

    DEFF Research Database (Denmark)

    Shim, Irene; Gingerich, Karl. A.

    1999-01-01

    The low-lying electronic states of NiC are investigated by all-electron ab initio multi-configuration self-consistent-field (CASSCF) calculations including relativistic corrections. The electronic structure of NiC is interpreted as perturbed antiferromagnetic couplings of the localized angular...

  4. Force fields for silicas and aluminophosphates based on ab initio calculations

    NARCIS (Netherlands)

    Beest, van B.W.H.; Kramer, G.J.; Santen, van R.A.

    1990-01-01

    Authors address the problem of finding interat. force fields for silicas from ab initio calcns. on small clusters. The force field cannot be detd. from cluster data alone; incorporation of bulk-system information into the force field remains essential. Bearing this in mind, authors derive a force

  5. Hexamethylcyclopentadiene: time-resolved photoelectron spectroscopy and ab initio multiple spawning simulations

    DEFF Research Database (Denmark)

    Wolf, T. J. A.; Kuhlman, Thomas Scheby; Schalk, O.

    2014-01-01

    comparing time-resolved photoelectron spectroscopy (TRPES) with ab initio multiple spawning (AIMS) simulations on the MS-MR-CASPT2 level of theory. We disentangle the relationship between two phenomena that dominate the immediate molecular response upon light absorption: a spectrally dependent delay...

  6. Unraveling the structure of the h-BN/Rh(111) nanomesh with ab initio calculations

    International Nuclear Information System (INIS)

    Laskowski, R; Blaha, P

    2008-01-01

    The properties of a single layer of h-BN on top of a Rh(111) surface are discussed in terms of an ab initio generated force field approach as well as by direct ab initio density-functional theory (DFT) calculations. A single-layer model for the h-BN/Rh(111) nanomesh, in contrast to a previously considered (incomplete) double-layer model of h-BN, can explain the experimental data. The main focus of this work is to compare a force field approach described earlier in (Laskowski et al 2007 Phys. Rev. Lett. 98 106802) with direct ab initio calculations. The calculated geometry of the h-BN layer is very similar to the structure predicted by the force field approach. The ab initio calculated density of states projected on N-p x,y of BN corresponding to 'low' and 'high' regions with respect to the Rh surface shows a 1 eV splitting and thus explains the observed σ-band splitting. Moreover, we find good agreement between calculated and experimental scanning tunneling microscope (STM) images of this system

  7. Precise Ab-initio prediction of terahertz vibrational modes in crystalline systems

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd; Clark, Stewart J.

    2007-01-01

    We use a combination of experimental THz time-domain spectroscopy and ab-initio density functional perturbative theory to accurately predict the terahertz vibrational spectrum of molecules in the crystalline phase. Our calculations show that distinct vibrational modes found in solid-state materials...

  8. Ab initio study of gas phase and water-assisted tautomerization of ...

    Indian Academy of Sciences (India)

    WINTEC

    Water-assisted tautomerization in maleimide and formamide showed that difference in energy barrier reduces to 2⋅83 kcal/mol from 10⋅41 kcal/mol (in gas phase) at B3LYP level, which resulted that maleimide readily undergoes tautomerization in water molecule. Keywords. Ab Initio calculations; maleimide; formamide; ...

  9. Ductility improvement of Mg alloys by solid solution: Ab initio modeling, synthesis and mechanical properties

    Czech Academy of Sciences Publication Activity Database

    Sandlöbes, S.; Pei, Z.; Friák, Martin; Zhu, L.-F.; Wang, F.; Zaefferer, S.; Raabe, D.; Neugebauer, J.

    2014-01-01

    Roč. 70, MAY (2014), s. 92-104 ISSN 1359-6454 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:68081723 Keywords : Magnesium * Rare-earth elements * Ductility * Modeling * Ab initio Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.465, year: 2014

  10. Computationally efficient and quantitatively accurate multiscale simulation of solid-solution strengthening by ab initio calculation

    Czech Academy of Sciences Publication Activity Database

    Ma, D.; Friák, Martin; von Pezold, J.; Raabe, D.; Neugebauer, J.

    2015-01-01

    Roč. 85, FEB (2015), s. 53-66 ISSN 1359-6454 Institutional support: RVO:68081723 Keywords : Solid-solution strengthening * DFT * Peierls–Nabarro model * Ab initio * Al alloys Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.058, year: 2015

  11. A fragment-based approach towards ab-initio treatment of polymeric ...

    Indian Academy of Sciences (India)

    Reshma S Pingale

    2017-06-20

    Jun 20, 2017 ... Keywords. π-Conjugated polymer; divide and conquer; ab-initio; fragmentation. PACS Nos 31.15.A−; 36.20. ... cut the parent system into a set of overlapping small fragments and .... some oligomers, we approached the problem by increas- ..... Financial support of DST, Govt. of India, New Delhi, in the form of ...

  12. Ab initio molecular dynamics approach to a quantitative description of ion pairing in water

    Czech Academy of Sciences Publication Activity Database

    Pluhařová, Eva; Maršálek, Ondřej; Schmidt, B.; Jungwirth, Pavel

    2013-01-01

    Roč. 4, č. 23 (2013), s. 4177-4181 ISSN 1948-7185 R&D Projects: GA ČR GBP208/12/G016 Institutional support: RVO:61388963 Keywords : ion pairing * charge transfer * water * ab initio molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.687, year: 2013

  13. One Size Fits All? Learning Conditions and Working Memory Capacity in "Ab Initio" Language Development

    Science.gov (United States)

    Sanz, Cristina; Lin, Hui-Ju; Lado, Beatriz; Stafford, Catherine A.; Bowden, Harriet W.

    2016-01-01

    The article summarizes results from two experimental studies (N = 23, N = 21) investigating the extent to which working memory capacity (WMC) intervenes in "ab initio" language development under two pedagogical conditions [± grammar lesson + input-based practice + explicit feedback]. The linguistic target is the use of morphosyntax to…

  14. Conformational Sampling by Ab Initio Molecular Dynamics Simulations Improves NMR Chemical Shift Predictions

    Czech Academy of Sciences Publication Activity Database

    Dračínský, Martin; Möller, H. M.; Exner, T. E.

    2013-01-01

    Roč. 9, č. 8 (2013), s. 3806-3815 ISSN 1549-9618 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : ab initio molecular dynamics * NMR spectroscopy * DFT calculations * hydration Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.310, year: 2013

  15. Matrix product operators, matrix product states, and ab initio density matrix renormalization group algorithms

    Science.gov (United States)

    Chan, Garnet Kin-Lic; Keselman, Anna; Nakatani, Naoki; Li, Zhendong; White, Steven R.

    2016-07-01

    Current descriptions of the ab initio density matrix renormalization group (DMRG) algorithm use two superficially different languages: an older language of the renormalization group and renormalized operators, and a more recent language of matrix product states and matrix product operators. The same algorithm can appear dramatically different when written in the two different vocabularies. In this work, we carefully describe the translation between the two languages in several contexts. First, we describe how to efficiently implement the ab initio DMRG sweep using a matrix product operator based code, and the equivalence to the original renormalized operator implementation. Next we describe how to implement the general matrix product operator/matrix product state algebra within a pure renormalized operator-based DMRG code. Finally, we discuss two improvements of the ab initio DMRG sweep algorithm motivated by matrix product operator language: Hamiltonian compression, and a sum over operators representation that allows for perfect computational parallelism. The connections and correspondences described here serve to link the future developments with the past and are important in the efficient implementation of continuing advances in ab initio DMRG and related algorithms.

  16. Ab initio calculation atomics ground state wave function for interactions Ion- Atom

    International Nuclear Information System (INIS)

    Shojaee, F.; Bolori zadeh, M. A.

    2007-01-01

    Ab initio calculation atomics ground state wave function for interactions Ion- Atom Atomic wave function expressed in a Slater - type basis obtained within Roothaan- Hartree - Fock for the ground state of the atoms He through B. The total energy is given for each atom.

  17. Ab initio and work function and surface energy anisotropy of LaB6

    NARCIS (Netherlands)

    Uijttewaal, M. A.; de Wijs, G. A.; de Groot, R. A.

    2006-01-01

    Lanthanum hexaboride is one of the cathode materials most used in high-power electronics technology, but the many experimental results do not provide a consistent picture of the surface properties. Therefore, we report the first ab initio calculations of the work functions and surface energies of

  18. Mechanical properties of carbynes investigated by ab initio total-energy calculations

    DEFF Research Database (Denmark)

    Castelli, Ivano E.; Salvestrini, Paolo; Manini, Nicola

    2012-01-01

    As sp carbon chains (carbynes) are relatively rigid molecular objects, can we exploit them as construction elements in nanomechanics? To answer this question, we investigate their remarkable mechanical properties by ab initio total-energy simulations. In particular, we evaluate their linear...

  19. Investigation of the Hydroxylation Mechanism of Noncoupled Copper Oxygenases by Ab Initio Molecular Dynamics Simulations

    Czech Academy of Sciences Publication Activity Database

    Meliá, C.; Ferrer, S.; Řezáč, Jan; Parisel, O.; Reinaud, O.; Moliner, V.; de la Lande, A.

    2013-01-01

    Roč. 19, č. 51 (2013), s. 17328-17337 ISSN 0947-6539 Institutional support: RVO:61388963 Keywords : ab initio calculations * copper * electron transfer * enzymes * molecular dynamics * reaction mechanisms Subject RIV: CC - Organic Chemistry Impact factor: 5.696, year: 2013

  20. Ab initio study of antiphase boundaries and stacking faults in L12 and DO22 compounds

    DEFF Research Database (Denmark)

    Rosengaard, N. M.; Skriver, Hans Lomholt

    1994-01-01

    We have performed ab initio calculations of the energies of antiphase boundaries as well as complex and superlattice intrinsic stacking faults in nine intermetallic compounds observed in the face-centered-cubic L1(2) and DO22 structures. The calculations were performed by means of a Green...

  1. The Pu–U–Am system: An ab initio informed CALPHAD thermodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Perron, A., E-mail: perron1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Turchi, P.E.A.; Landa, A.; Söderlind, P. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Ravat, B.; Oudot, B.; Delaunay, F. [CEA-Centre de Valduc, 21120 Is sur Tille (France)

    2015-03-15

    Highlights: • The ab initio informed CALPHAD assessment of the Am–U system has been realized. • A strong tendency toward phase separation across the whole composition range is predicted. • The ab initio informed Pu–U–Am thermodynamic database has been developed. • The solubility of Am and U in the liquid phase is improved by adding Pu. • The δ-Pu (fcc) phase is strongly stabilized by Am, on the contrary to the bcc phase. - Abstract: Phase diagram and thermodynamic properties of the Am–U system, that are experimentally unknown, are calculated using the CALPHAD method with input from ab initio electronic-structure calculations for the fcc and bcc phases. A strong tendency toward phase separation across the whole composition range is predicted. In addition, ab initio informed Pu–U and Am–Pu thermodynamic assessments are combined to build a Pu–U–Am thermodynamic database. Regarding the Pu-rich corner of the ternary system, predictions indicate that Am acts as a powerful δ-Pu (fcc) stabilizer. In the U-rich corner, similar predictions are made but to a lesser extent. In both cases, the bcc phase is destabilized and the fcc phase is enhanced. Finally, results and methodology are discussed and compared with previous assessments and guidelines are provided for further experimental studies.

  2. Ab-initio calculations of electric field gradient in Ru compounds and ...

    Indian Academy of Sciences (India)

    S N Mishra

    2017-07-11

    Jul 11, 2017 ... with calculated electric field gradient (EFG) for a large number of Ru-based compounds. The ab-initio ... zz assumed to stem from geometric arrangement of ... tant nuclear probes for the measurements of quadrupole ... with the unit cell including the nucleus and no restriction is put on ..... The effect of on-site ...

  3. Steel — ab Initio: Quantum Mechanics Guided Design of New Fe-Based Materials

    Science.gov (United States)

    Prahl, Ulrich; Bleck, Wolfgang; Saeed-Akbari, Alireza

    This contribution reports the results of the collaborative research unit SFB 761 "Steel — ab initio", a cooperative project between RWTH Aachen University and the Max-Planck-Institute for Iron Research in Düsseldorf (MPIE) financed by the German Research Foundation (DFG). For the first time, it is exploited how ab initio approaches may lead to a detailed understanding and thus to a specific improvement of material development. The challenge lies in the combination of abstract natural science theories with rather engineering-like established concepts. Aiming at the technological target of the development of a new type of structural materials based on Fe-Mn-C alloys, the combination of ab initio and engineering methods is new, but could be followed quite successfully. Three major topics are treated in this research unit: a) development of a new method for material- and process-development based on ab initio calculations; b) design of a new class of structural materials with extraordinary property combinations; c) acceleration of development time and reduction of experimental efforts and complexity for material- and process-development. In the present work, an overview of the results of the first five years as well as an outlook for the upcoming three-year period is given.

  4. Ab initio study of the bcc-hcp transformation in iron

    Czech Academy of Sciences Publication Activity Database

    Friák, Martin; Šob, Mojmír

    2008-01-01

    Roč. 77, č. 17 (2008), 174117/1-174117/7 ISSN 1098-0121 R&D Projects: GA MŠk OC 147; GA AV ČR IAA1041302 Institutional research plan: CEZ:AV0Z20410507 Keywords : ab initio calculations * phase transformations * iron Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

  5. Gait Deviation Index, Gait Profile Score and Gait Variable Score in children with spastic cerebral palsy

    DEFF Research Database (Denmark)

    Rasmussen, Helle Mätzke; Nielsen, Dennis Brandborg; Pedersen, Niels Wisbech

    2015-01-01

    Abstract The Gait Deviation Index (GDI) and Gait Profile Score (GPS) are the most used summary measures of gait in children with cerebral palsy (CP). However, the reliability and agreement of these indices have not been investigated, limiting their clinimetric quality for research and clinical...... to good reliability with ICCs of 0.4–0.7. The agreement for the GDI and the logarithmically transformed GPS, in terms of the standard error of measurement as a percentage of the grand mean (SEM%) varied from 4.1 to 6.7%, whilst the smallest detectable change in percent (SDC%) ranged from 11.3 to 18...

  6. Validation of the Danish version of the Oxford Elbow Score

    DEFF Research Database (Denmark)

    Plaschke, Hans Christian; Jørgensen, Andreas Møller; Thillemann, Theis Muncholm

    2013-01-01

    The Oxford Elbow Score (OES) is a patient-related outcome measure quantifying quality of life in relation to elbow disorders. This 12-item patient-administered English questionnaire comprises three domains: function, social-psychological status and pain. The purpose of this study was to examine...

  7. Can facial uniqueness be inferred from impostor scores?

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    2013-01-01

    In Biometrics, facial uniqueness is commonly inferred from impostor similarity scores. In this paper, we show that such uniqueness measures are highly unstable in the presence of image quality variations like pose, noise and blur. We also experimentally demonstrate the instability of a recently

  8. Interval Coded Scoring: a toolbox for interpretable scoring systems

    Directory of Open Access Journals (Sweden)

    Lieven Billiet

    2018-04-01

    Full Text Available Over the last decades, clinical decision support systems have been gaining importance. They help clinicians to make effective use of the overload of available information to obtain correct diagnoses and appropriate treatments. However, their power often comes at the cost of a black box model which cannot be interpreted easily. This interpretability is of paramount importance in a medical setting with regard to trust and (legal responsibility. In contrast, existing medical scoring systems are easy to understand and use, but they are often a simplified rule-of-thumb summary of previous medical experience rather than a well-founded system based on available data. Interval Coded Scoring (ICS connects these two approaches, exploiting the power of sparse optimization to derive scoring systems from training data. The presented toolbox interface makes this theory easily applicable to both small and large datasets. It contains two possible problem formulations based on linear programming or elastic net. Both allow to construct a model for a binary classification problem and establish risk profiles that can be used for future diagnosis. All of this requires only a few lines of code. ICS differs from standard machine learning through its model consisting of interpretable main effects and interactions. Furthermore, insertion of expert knowledge is possible because the training can be semi-automatic. This allows end users to make a trade-off between complexity and performance based on cross-validation results and expert knowledge. Additionally, the toolbox offers an accessible way to assess classification performance via accuracy and the ROC curve, whereas the calibration of the risk profile can be evaluated via a calibration curve. Finally, the colour-coded model visualization has particular appeal if one wants to apply ICS manually on new observations, as well as for validation by experts in the specific application domains. The validity and applicability

  9. Functional Movement Screen: Pain versus composite score and injury risk.

    Science.gov (United States)

    Alemany, Joseph A; Bushman, Timothy T; Grier, Tyson; Anderson, Morgan K; Canham-Chervak, Michelle; North, William J; Jones, Bruce H

    2017-11-01

    The Functional Movement Screen (FMS™) has been used as a screening tool to determine musculoskeletal injury risk using composite scores based on movement quality and/or pain. However, no direct comparisons between movement quality and pain have been quantified. Retrospective injury data analysis. Male Soldiers (n=2154, 25.0±1.3years; 26.2±.7kg/m 2 ) completed the FMS (scored from 0 points (pain) to 3 points (no pain and perfect movement quality)) with injury data over the following six months. The FMS is seven movements. Injury data were collected six months after FMS completion. Sensitivity, specificity, receiver operator characteristics and positive and negative predictive values were calculated for pain occurrence and low (≤14 points) composite score. Risk, risk ratios (RR) and 95% confidence intervals were calculated for injury risk. Pain was associated with slightly higher injury risk (RR=1.62) than a composite score of ≤14 points (RR=1.58). When comparing injury risk between those who scored a 1, 2 or 3 on each individual movement, no differences were found (except deep squat). However, Soldiers who experienced pain on any movement had a greater injury risk than those who scored 3 points for that movement (pmovements in which pain occurrence increased, so did injury risk (p<0.01). Pain occurrence may be a stronger indicator of injury risk than a low composite score and provides a simpler method of evaluating injury risk compared to the full FMS. Published by Elsevier Ltd.

  10. Analysis of some conventional ab initio gene finders using human ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... highly dependent upon the quantity and quality of pre- existing .... measures of predictive accuracy on nucleotide and exon level were measured for each ...... Bayraktaroglu L, Birney E, Crosby MA, Kaminker JS, Matthews BB,.

  11. Investigation of polarization effects in the gramicidin A channel from ab initio molecular dynamics simulations.

    Science.gov (United States)

    Timko, Jeff; Kuyucak, Serdar

    2012-11-28

    Polarization is an important component of molecular interactions and is expected to play a particularly significant role in inhomogeneous environments such as pores and interfaces. Here we investigate the effects of polarization in the gramicidin A ion channel by performing quantum mechanics/molecular mechanics molecular dynamics (MD) simulations and comparing the results with those obtained from classical MD simulations with non-polarizable force fields. We consider the dipole moments of backbone carbonyl groups and channel water molecules as well as a number of structural quantities of interest. The ab initio results show that the dipole moments of the carbonyl groups and water molecules are highly sensitive to the hydrogen bonds (H-bonds) they participate in. In the absence of a K(+) ion, water molecules in the channel are quite mobile, making the H-bond network highly dynamic. A central K(+) ion acts as an anchor for the channel waters, stabilizing the H-bond network and thereby increasing their average dipole moments. In contrast, the K(+) ion has little effect on the dipole moments of the neighboring carbonyl groups. The weakness of the ion-peptide interactions helps to explain the near diffusion-rate conductance of K(+) ions through the channel. We also address the sampling issue in relatively short ab initio MD simulations. Results obtained from a continuous 20 ps ab initio MD simulation are compared with those generated by sampling ten windows from a much longer classical MD simulation and running each window for 2 ps with ab initio MD. Both methods yield similar results for a number of quantities of interest, indicating that fluctuations are fast enough to justify the short ab initio MD simulations.

  12. Exploring a Source of Uneven Score Equity across the Test Score Range

    Science.gov (United States)

    Huggins-Manley, Anne Corinne; Qiu, Yuxi; Penfield, Randall D.

    2018-01-01

    Score equity assessment (SEA) refers to an examination of population invariance of equating across two or more subpopulations of test examinees. Previous SEA studies have shown that score equity may be present for examinees scoring at particular test score ranges but absent for examinees scoring at other score ranges. No studies to date have…

  13. A Review of Solid-Solution Models of High-Entropy Alloys Based on Ab Initio Calculations

    Directory of Open Access Journals (Sweden)

    Fuyang Tian

    2017-11-01

    Full Text Available Similar to the importance of XRD in experiments, ab initio calculations, as a powerful tool, have been applied to predict the new potential materials and investigate the intrinsic properties of materials in theory. As a typical solid-solution material, the large degree of uncertainty of high-entropy alloys (HEAs results in the difficulty of ab initio calculations application to HEAs. The present review focuses on the available ab initio based solid-solution models (virtual lattice approximation, coherent potential approximation, special quasirandom structure, similar local atomic environment, maximum-entropy method, and hybrid Monte Carlo/molecular dynamics and their applications and limits in single phase HEAs.

  14. Comparison of the Classifier Oriented Gait Score and the Gait Profile Score based on imitated gait impairments.

    Science.gov (United States)

    Christian, Josef; Kröll, Josef; Schwameder, Hermann

    2017-06-01

    Common summary measures of gait quality such as the Gait Profile Score (GPS) are based on the principle of measuring a distance from the mean pattern of a healthy reference group in a gait pattern vector space. The recently introduced Classifier Oriented Gait Score (COGS) is a pathology specific score that measures this distance in a unique direction, which is indicated by a linear classifier. This approach has potentially improved the discriminatory power to detect subtle changes in gait patterns but does not incorporate a profile of interpretable sub-scores like the GPS. The main aims of this study were to extend the COGS by decomposing it into interpretable sub-scores as realized in the GPS and to compare the discriminative power of the GPS and COGS. Two types of gait impairments were imitated to enable a high level of control of the gait patterns. Imitated impairments were realized by restricting knee extension and inducing leg length discrepancy. The results showed increased discriminatory power of the COGS for differentiating diverse levels of impairment. Comparison of the GPS and COGS sub-scores and their ability to indicate changes in specific variables supports the validity of both scores. The COGS is an overall measure of gait quality with increased power to detect subtle changes in gait patterns and might be well suited for tracing the effect of a therapeutic treatment over time. The newly introduced sub-scores improved the interpretability of the COGS, which is helpful for practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Timing of Emergency Medicine Student Evaluation Does Not Affect Scoring.

    Science.gov (United States)

    Hiller, Katherine M; Waterbrook, Anna; Waters, Kristina

    2016-02-01

    Evaluation of medical students rotating through the emergency department (ED) is an important formative and summative assessment method. Intuitively, delaying evaluation should affect the reliability of this assessment method, however, the effect of evaluation timing on scoring is unknown. A quality-improvement project evaluating the timing of end-of-shift ED evaluations at the University of Arizona was performed to determine whether delay in evaluation affected the score. End-of-shift ED evaluations completed on behalf of fourth-year medical students from July 2012 to March 2013 were reviewed. Forty-seven students were evaluated 547 times by 46 residents and attendings. Evaluation scores were means of anchored Likert scales (1-5) for the domains of energy/interest, fund of knowledge, judgment/problem-solving ability, clinical skills, personal effectiveness, and systems-based practice. Date of shift, date of evaluation, and score were collected. Linear regression was performed to determine whether timing of the evaluation had an effect on evaluation score. Data were complete for 477 of 547 evaluations (87.2%). Mean evaluation score was 4.1 (range 2.3-5, standard deviation 0.62). Evaluations took a mean of 8.5 days (median 4 days, range 0-59 days, standard deviation 9.77 days) to complete. Delay in evaluation had no significant effect on score (p = 0.983). The evaluation score was not affected by timing of the evaluation. Variance in scores was similar for both immediate and delayed evaluations. Considerable amounts of time and energy are expended tracking down delayed evaluations. This activity does not impact a student's final grade. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Identify High-Quality Protein Structural Models by Enhanced K-Means.

    Science.gov (United States)

    Wu, Hongjie; Li, Haiou; Jiang, Min; Chen, Cheng; Lv, Qiang; Wu, Chuang

    2017-01-01

    Background. One critical issue in protein three-dimensional structure prediction using either ab initio or comparative modeling involves identification of high-quality protein structural models from generated decoys. Currently, clustering algorithms are widely used to identify near-native models; however, their performance is dependent upon different conformational decoys, and, for some algorithms, the accuracy declines when the decoy population increases. Results. Here, we proposed two enhanced K -means clustering algorithms capable of robustly identifying high-quality protein structural models. The first one employs the clustering algorithm SPICKER to determine the initial centroids for basic K -means clustering ( SK -means), whereas the other employs squared distance to optimize the initial centroids ( K -means++). Our results showed that SK -means and K -means++ were more robust as compared with SPICKER alone, detecting 33 (59%) and 42 (75%) of 56 targets, respectively, with template modeling scores better than or equal to those of SPICKER. Conclusions. We observed that the classic K -means algorithm showed a similar performance to that of SPICKER, which is a widely used algorithm for protein-structure identification. Both SK -means and K -means++ demonstrated substantial improvements relative to results from SPICKER and classical K -means.

  17. Serious Gaming for Test & Evaluation of Clean-Slate (Ab Initio) National Airspace System (NAS) Designs

    Science.gov (United States)

    Allen, B. Danette; Alexandrov, Natalia

    2016-01-01

    Incremental approaches to air transportation system development inherit current architectural constraints, which, in turn, place hard bounds on system capacity, efficiency of performance, and complexity. To enable airspace operations of the future, a clean-slate (ab initio) airspace design(s) must be considered. This ab initio National Airspace System (NAS) must be capable of accommodating increased traffic density, a broader diversity of aircraft, and on-demand mobility. System and subsystem designs should scale to accommodate the inevitable demand for airspace services that include large numbers of autonomous Unmanned Aerial Vehicles and a paradigm shift in general aviation (e.g., personal air vehicles) in addition to more traditional aerial vehicles such as commercial jetliners and weather balloons. The complex and adaptive nature of ab initio designs for the future NAS requires new approaches to validation, adding a significant physical experimentation component to analytical and simulation tools. In addition to software modeling and simulation, the ability to exercise system solutions in a flight environment will be an essential aspect of validation. The NASA Langley Research Center (LaRC) Autonomy Incubator seeks to develop a flight simulation infrastructure for ab initio modeling and simulation that assumes no specific NAS architecture and models vehicle-to-vehicle behavior to examine interactions and emergent behaviors among hundreds of intelligent aerial agents exhibiting collaborative, cooperative, coordinative, selfish, and malicious behaviors. The air transportation system of the future will be a complex adaptive system (CAS) characterized by complex and sometimes unpredictable (or unpredicted) behaviors that result from temporal and spatial interactions among large numbers of participants. A CAS not only evolves with a changing environment and adapts to it, it is closely coupled to all systems that constitute the environment. Thus, the ecosystem that

  18. Ab initio studies on [bmim][PF6]–CO2 mixture and CO2 clusters

    Indian Academy of Sciences (India)

    Wintec

    Ionic liquids; supercritical carbon dioxide; ab initio; molecular dynamics. 1. Introduction .... Several experi- mental and simulation studies have been carried out to .... from an analysis of its electronic polarizability (α), which is a measure of the ...

  19. Controlling Magnetic and Ferroelectric Order Through Geometry: Synthesis, Ab Initio Theory, Characterization of New Multi-Ferric Fluoride Materials

    Energy Technology Data Exchange (ETDEWEB)

    Halasyamani, Shiv [Univ. of Houston, TX (United States); Fennie, Craig [Cornell Univ., Ithaca, NY (United States)

    2016-11-03

    We have focused on the synthesis, characterization, and ab initio theory on multi-functional mixed-metal fluorides. With funding from the DOE, we have successfully synthesized and characterized a variety of mixed metal fluoride materials.

  20. Structural, magnetic and electronic properties of FexCoyIrz (x + y + z = 5, 6) clusters: an ab initio study

    KAUST Repository

    Devi, Assa Aravindh Sasikala

    2014-01-01

    Investigations on freestanding binary and ternary clusters of Fe (x) Co (y) Ir (z) (x + y + z = 5, 6) are carried out using ab initio density functional theory techniques. The geometry, chemical order, binding energy, magnetic moment and electronic

  1. Comparison between s - and d -electron mediated transport in a photoswitching dithienylethene molecule using ab initio transport methods

    KAUST Repository

    Odell, Anders; Delin, Anna; Johansson, Bö rje; Ulman, Kanchan; Narasimhan, Shobhana; Rungger, Ivan; Sanvito, Stefano

    2011-01-01

    The influence of the electrode's Fermi surface on the transport properties of a photoswitching molecule is investigated with state-of-the-art ab initio transport methods. We report results for the conducting properties of the two forms

  2. "Score the Core" Web-based pathologist training tool improves the accuracy of breast cancer IHC4 scoring.

    Science.gov (United States)

    Engelberg, Jesse A; Retallack, Hanna; Balassanian, Ronald; Dowsett, Mitchell; Zabaglo, Lila; Ram, Arishneel A; Apple, Sophia K; Bishop, John W; Borowsky, Alexander D; Carpenter, Philip M; Chen, Yunn-Yi; Datnow, Brian; Elson, Sarah; Hasteh, Farnaz; Lin, Fritz; Moatamed, Neda A; Zhang, Yanhong; Cardiff, Robert D

    2015-11-01

    Hormone receptor status is an integral component of decision-making in breast cancer management. IHC4 score is an algorithm that combines hormone receptor, HER2, and Ki-67 status to provide a semiquantitative prognostic score for breast cancer. High accuracy and low interobserver variance are important to ensure the score is accurately calculated; however, few previous efforts have been made to measure or decrease interobserver variance. We developed a Web-based training tool, called "Score the Core" (STC) using tissue microarrays to train pathologists to visually score estrogen receptor (using the 300-point H score), progesterone receptor (percent positive), and Ki-67 (percent positive). STC used a reference score calculated from a reproducible manual counting method. Pathologists in the Athena Breast Health Network and pathology residents at associated institutions completed the exercise. By using STC, pathologists improved their estrogen receptor H score and progesterone receptor and Ki-67 proportion assessment and demonstrated a good correlation between pathologist and reference scores. In addition, we collected information about pathologist performance that allowed us to compare individual pathologists and measures of agreement. Pathologists' assessment of the proportion of positive cells was closer to the reference than their assessment of the relative intensity of positive cells. Careful training and assessment should be used to ensure the accuracy of breast biomarkers. This is particularly important as breast cancer diagnostics become increasingly quantitative and reproducible. Our training tool is a novel approach for pathologist training that can serve as an important component of ongoing quality assessment and can improve the accuracy of breast cancer prognostic biomarkers. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. [New scores in renal transplantation: How can we use them?

    Science.gov (United States)

    Hazzan, Marc; Frimat, Marie; Glowacki, François; Lionet, Arnaud; Provot, François; Noël, Christian

    2017-04-01

    In renal transplant medicine, several scores have been recently developed in order to help decision-making in clinical practice. The aim of this update is to focus on these new scores that allow to better estimate the quality of the renal transplant, to refine the allocation policy, to help registration of old recipients on the waiting list, or to evaluate the risk to develop end-stage renal failure after living donation. Copyright © 2017 Association Société de néphrologie. Published by Elsevier Masson SAS. All rights reserved.

  4. Formation of borrower’s bank credit scoring integrated model

    Directory of Open Access Journals (Sweden)

    O.V. Lysenok

    2017-03-01

    Full Text Available The article proposes the borrower’s bank credit scoring model that is of particular relevance in an unstable world and Ukrainian financial markets. The essence of this integrated model is the consistent definition of indicators, which analyze the financial and economic situation and development of scoring that allows to calculate overall index, that is, the integral factor of credit scoring level of the bank to calculate which one uses the formed set of factors characterizing riskiness, profitability and liquidity of the banking institution. The author determines the factors according to their functional purpose; the former ones are divided into four groups: capital adequacy, loan portfolio quality, profitability and liquidity. Each group consists of four indicators; each indicator is assigned thresholds to determine the appropriate credit scoring level of the bank for one or another direction. The higher is the value of the integral factor, the more efficient and less risky is the financial and economic activity of banks and the higher is their credit scoring level. The study concludes that the proposed model for bank credit scoring differs with its transparency and clarity due to use in its implementation only public information. The disadvantages include the presence of the subjective factor in assigning a certain number of points based on expert and normative methods.

  5. Ab initio calculation of a global potential, vibrational energies, and wave functions for HCN/HNC, and a simulation of the (A-tilde)-(X-tilde) emission spectrum

    Science.gov (United States)

    Bowman, Joel M.; Gazdy, Bela; Bentley, Joseph A.; Lee, Timothy J.; Dateo, Christopher E.

    1993-01-01

    A potential energy surface for the HCN/HNC system which is a fit to extensive, high-quality ab initio, coupled-cluster calculations is presented. All HCN and HNC states with energies below the energy of the first delocalized state are reported and characterized. Vibrational transition energies are compared with all available experimental data on HCN and HNC, including high CH-overtone states up to 23,063/cm. A simulation of the (A-tilde)-(X-tilde) stimulated emission pumping (SEP) spectrum is also reported, and the results are compared to experiment. Franck-Condon factors are reported for odd bending states of HCN, with one quantum of vibrational angular momentum, in order to compare with the recent assignment by Jonas et al. (1992), on the basis of axis-switching arguments of a number of previously unassigned states in the SEP spectrum.

  6. Linkage between company scores and stock returns

    Directory of Open Access Journals (Sweden)

    Saban Celik

    2017-12-01

    Full Text Available Previous studies on company scores conducted at firm-level, generally concluded that there exists a positive relation between company scores and stock returns. Motivated by these studies, this study examines the relationship between company scores (Corporate Governance Score, Economic Score, Environmental Score, and Social Score and stock returns, both at portfolio-level analysis and firm-level cross-sectional regressions. In portfolio-level analysis, stocks are sorted based on each company scores and quintile portfolio are formed with different levels of company scores. Then, existence and significance of raw returns and risk-adjusted returns difference between portfolios with the extreme company scores (portfolio 10 and portfolio 1 is tested. In addition, firm-level cross-sectional regression is performed to examine the significance of company scores effects with control variables. While portfolio-level analysis results indicate that there is no significant relation between company scores and stock returns; firm-level analysis indicates that economic, environmental, and social scores have effect on stock returns, however, significance and direction of these effects change, depending on the included control variables in the cross-sectional regression.

  7. Ab initio assisted process modeling for Si-based nanoelectronic devices

    International Nuclear Information System (INIS)

    Windl, Wolfgang

    2005-01-01

    In this paper, we discuss concepts and examples of ab initio calculations assisting physics-based process simulation. We focus on how to determine diffusion and reaction constants, where modern methods such as the nudged elastic band method allow a systematic and reliable search for the minimum energy migration path and barrier. We show that once the saddle point is determined, the underlying harmonic transition state theory also allows to calculate the prefactors. The discussed examples include nitrogen diffusion, boron deactivation and boron interface segregation. Finally, some concepts are discussed for future device technologies such as molecular devices, where the currently prevalent multiscale approach (kinetic parameters used in higher level models like diffusion-reaction or kinetic Monte Carlo modeling) would not be sensible anymore. As an example, we described the ab initio temperature-accelerated dynamics modeling of contact formation in carbon nanotube devices

  8. Nuclear quantum effects in ab initio dynamics: Theory and experiments for lithium imide

    Science.gov (United States)

    Ceriotti, Michele; Miceli, Giacomo; Pietropaolo, Antonino; Colognesi, Daniele; Nale, Angeloclaudio; Catti, Michele; Bernasconi, Marco; Parrinello, Michele

    2010-11-01

    Owing to their small mass, hydrogen atoms exhibit strong quantum behavior even at room temperature. Including these effects in first-principles calculations is challenging because of the huge computational effort required by conventional techniques. Here we present the first ab initio application of a recently developed stochastic scheme, which allows to approximate nuclear quantum effects inexpensively. The proton momentum distribution of lithium imide, a material of interest for hydrogen storage, was experimentally measured by inelastic neutron-scattering experiments and compared with the outcome of quantum thermostatted ab initio dynamics. We obtain favorable agreement between theory and experiments for this purely quantum-mechanical property, thereby demonstrating that it is possible to improve the modeling of complex hydrogen-containing materials without additional computational effort.

  9. Computational prediction of muon stopping sites using ab initio random structure searching (AIRSS)

    Science.gov (United States)

    Liborio, Leandro; Sturniolo, Simone; Jochym, Dominik

    2018-04-01

    The stopping site of the muon in a muon-spin relaxation experiment is in general unknown. There are some techniques that can be used to guess the muon stopping site, but they often rely on approximations and are not generally applicable to all cases. In this work, we propose a purely theoretical method to predict muon stopping sites in crystalline materials from first principles. The method is based on a combination of ab initio calculations, random structure searching, and machine learning, and it has successfully predicted the MuT and MuBC stopping sites of muonium in Si, diamond, and Ge, as well as the muonium stopping site in LiF, without any recourse to experimental results. The method makes use of Soprano, a Python library developed to aid ab initio computational crystallography, that was publicly released and contains all the software tools necessary to reproduce our analysis.

  10. Ab Initio Many-Body Calculations Of Nucleon-Nucleus Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S; Navratil, P

    2008-12-17

    We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We outline technical details and present phase shift results for neutron scattering on {sup 3}H, {sup 4}He and {sup 10}Be and proton scattering on {sup 3,4}He, using realistic nucleon-nucleon (NN) potentials. Our A = 4 scattering results are compared to earlier ab initio calculations. We find that the CD-Bonn NN potential in particular provides an excellent description of nucleon-{sup 4}He S-wave phase shifts. We demonstrate that a proper treatment of the coupling to the n-{sup 10}Be continuum is successful in explaining the parity-inverted ground state in {sup 11}Be.

  11. Large-scale ab initio configuration interaction calculations for light nuclei

    International Nuclear Information System (INIS)

    Maris, Pieter; Potter, Hugh; Vary, James P; Aktulga, H Metin; Ng, Esmond G; Yang Chao; Caprio, Mark A; Çatalyürek, Ümit V; Saule, Erik; Oryspayev, Dossay; Sosonkina, Masha; Zhou Zheng

    2012-01-01

    In ab-initio Configuration Interaction calculations, the nuclear wavefunction is expanded in Slater determinants of single-nucleon wavefunctions and the many-body Schrodinger equation becomes a large sparse matrix problem. The challenge is to reach numerical convergence to within quantified numerical uncertainties for physical observables using finite truncations of the infinite-dimensional basis space. We discuss strategies for constructing and solving the resulting large sparse matrix eigenvalue problems on current multicore computer architectures. Several of these strategies have been implemented in the code MFDn, a hybrid MPI/OpenMP Fortran code for ab-initio nuclear structure calculations that can scale to 100,000 cores and more. Finally, we will conclude with some recent results for 12 C including emerging collective phenomena such as rotational band structures using SRG evolved chiral N3LO interactions.

  12. An ab-initio study of mechanical, dynamical and electronic properties of MgEu intermetallic

    Science.gov (United States)

    Kumar, S. Ramesh; Jaiganesh, G.; Jayalakshmi, V.

    2018-04-01

    The theoretical investigation on the mechanical, dynamical and electronic properties of MgEu in CsCl-type structure has been carried out through the ab-initio calculations within the framework of the density functional theory and the density functional perturbation theory. For the purpose, Vienna Ab initio Simulation Package and Phonopy packages were used. Our calculated ground-state properties of MgEu are in good agreement with other available results. Our computed elastic constants and phonon spectrum results suggest that MgEu is mechanically and dynamically stable up to 5 GPa. The thermodynamic quantities as a function of temperatures are also reported and discussed. The band structure, density of states and charge density also calculated to understand the electronic properties of MgEu.

  13. Geometry optimization of supersymmetrical molecules in quantum chemical ab-initio calculations

    International Nuclear Information System (INIS)

    Gruenbichler, H.

    1985-01-01

    One-dimensional geometry optimizations in ab-initio SCF-calculations are investigated. It is shown, that the well known standard algorithms are sometimes too expensive and can be replaced or accompanied by more recent algorithms. Two alternatives were realized in the molecule calculating program GAUSSIAN 80, basing on the Fibonacci algorithm and Kryachco potential adjustment. The algorithms were compared in terms of accuracy of results, CPU-time used and reliability of the method. The results are presented in various tables, showing the efficiency of the various methods. A survey of the usual model potentials is given and the compatibility with ab-initio data is evaluated. (Author, shortened and translated by A.N.)

  14. Electronic properties of liquid Hg-In alloys : Ab-initio molecular dynamics study

    International Nuclear Information System (INIS)

    Sharma, Nalini; Ahluwalia, P. K.; Thakur, Anil

    2016-01-01

    Ab-initio molecular dynamics simulations are performed to study the structural properties of liquid Hg-In alloys. The interatomic interactions are described by ab-initio pseudopotentials given by Troullier and Martins. Three liquid Hg-In alloys (Hg_1_0In_9_0, Hg_3_0In_7_0_,_. Hg_5_0In_5_0, Hg_7_0In_3_0, and Hg_9_0Pb_1_0) at 299 K are considered. The calculated results for liquid Hg (l-Hg) and lead (l-In) are also drawn. Along with the calculated results of considered five liquid alloys of Hg-In alloy. The results obtained from electronic properties namely total density of state and partial density of states help to find the local arrangement of Hg and In atoms and the presence of liquid state in the considered five alloys.

  15. Raman spectroscopy, ab-initio model calculations, and conformational, equilibria in ionic liquids

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    2009-01-01

    spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT- Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methyl-imidazolium ([C4C1Im]+X-) salts. The rotational isomerism of the [C4C1Im]+ cation is described: the presence of anti.......3 Brief introduction to ab-initio model calculations .... 312 12.4 Case study on Raman spectroscopy and structure of imidazolium-based ionic liquids ..... 312 12.5 Raman spectra and structure of [C4C1Im]+ liquids ..... 315 12.6 Normal mode analysis and rotational isomerism of the [C4C1Im]+ cation...

  16. Molecular structure determination of cyclooctane by Ab Initio and electron diffraction methods in the gas phase

    International Nuclear Information System (INIS)

    Almeida, Wagner B. de

    2000-01-01

    The determination of the molecular structure of molecules is of fundamental importance in chemistry. X-rays and electron diffraction methods constitute in important tools for the elucidation of the molecular structure of systems in the solid state and gas phase, respectively. The use of quantum mechanical molecular orbital ab initio methods offer an alternative for conformational analysis studies. Comparison between theoretical results and those obtained experimentally in the gas phase can make a significant contribution for an unambiguous determination of the geometrical parameters. In this article the determination for an unambiguous determination of the geometrical parameters. In this article the determination of the molecular structure of the cyclooctane molecule by electron diffraction in the gas phase an initio calculations will be addressed, providing an example of a comparative analysis of theoretical and experimental predictions. (author)

  17. Specific interactions between DNA and regulatory protein controlled by ligand-binding: Ab initio molecular simulation

    International Nuclear Information System (INIS)

    Matsushita, Y.; Murakawa, T.; Shimamura, K.; Oishi, M.; Ohyama, T.; Kurita, N.

    2015-01-01

    The catabolite activator protein (CAP) is one of the regulatory proteins controlling the transcription mechanism of gene. Biochemical experiments elucidated that the complex of CAP with cyclic AMP (cAMP) is indispensable for controlling the mechanism, while previous molecular simulations for the monomer of CAP+cAMP complex revealed the specific interactions between CAP and cAMP. However, the effect of cAMP-binding to CAP on the specific interactions between CAP and DNA is not elucidated at atomic and electronic levels. We here considered the ternary complex of CAP, cAMP and DNA in solvating water molecules and investigated the specific interactions between them at atomic and electronic levels using ab initio molecular simulations based on classical molecular dynamics and ab initio fragment molecular orbital methods. The results highlight the important amino acid residues of CAP for the interactions between CAP and cAMP and between CAP and DNA

  18. Ab initio theoretical calculations of the electronic excitation energies of small water clusters.

    Science.gov (United States)

    Tachikawa, Hiroto; Yabushita, Akihiro; Kawasaki, Masahiro

    2011-12-14

    A direct ab initio molecular dynamics method has been applied to a water monomer and water clusters (H(2)O)(n) (n = 1-3) to elucidate the effects of zero-point energy (ZPE) vibration on the absorption spectra of water clusters. Static ab initio calculations without ZPE showed that the first electronic transitions of (H(2)O)(n), (1)B(1)←(1)A(1), are blue-shifted as a function of cluster size (n): 7.38 eV (n = 1), 7.58 eV (n = 2) and 8.01 eV (n = 3). The inclusion of the ZPE vibration strongly affects the excitation energies of a water dimer, and a long red-tail appears in the range of 6.42-6.90 eV due to the structural flexibility of a water dimer. The ultraviolet photodissociation of water clusters and water ice surfaces is relevant to these results.

  19. Ab Initio Calculations for the BaTiO3 (001) Surface Structure

    Institute of Scientific and Technical Information of China (English)

    XUE Xu-Yan; WANG Chun-Lei; ZHONG Wei-Lie

    2004-01-01

    @@ The ab initio method within the local density approximation is applied to calculate cubic BaTiO3 (001) surface relaxation and rumpling for two different terminations (BaO and TiO2). Our calculations demonstrate that cubic perovskite BaTiO3 crystals possess surface polarization, accompanied by the presence of the relevant electric field.We analyse their electronic structures (band structure, density of states and the electronic density redistribution with emphasis on the covalency effects). The results are also compared with that of the previous ab initio calculations. Considerable increases of Ti-O chemical bond covalency nearby the surface have been observed.The band gap reduces especially for the TiO2 termination.

  20. Ab initio molecular dynamics simulation of liquid water by quantum Monte Carlo

    International Nuclear Information System (INIS)

    Zen, Andrea; Luo, Ye; Mazzola, Guglielmo; Sorella, Sandro; Guidoni, Leonardo

    2015-01-01

    Although liquid water is ubiquitous in chemical reactions at roots of life and climate on the earth, the prediction of its properties by high-level ab initio molecular dynamics simulations still represents a formidable task for quantum chemistry. In this article, we present a room temperature simulation of liquid water based on the potential energy surface obtained by a many-body wave function through quantum Monte Carlo (QMC) methods. The simulated properties are in good agreement with recent neutron scattering and X-ray experiments, particularly concerning the position of the oxygen-oxygen peak in the radial distribution function, at variance of previous density functional theory attempts. Given the excellent performances of QMC on large scale supercomputers, this work opens new perspectives for predictive and reliable ab initio simulations of complex chemical systems

  1. Specific interactions between DNA and regulatory protein controlled by ligand-binding: Ab initio molecular simulation

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, Y., E-mail: kurita@cs.tut.ac.jp; Murakawa, T., E-mail: kurita@cs.tut.ac.jp; Shimamura, K., E-mail: kurita@cs.tut.ac.jp; Oishi, M., E-mail: kurita@cs.tut.ac.jp; Ohyama, T., E-mail: kurita@cs.tut.ac.jp; Kurita, N., E-mail: kurita@cs.tut.ac.jp [Department of Computer Science and Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi, 441-8580 (Japan)

    2015-02-27

    The catabolite activator protein (CAP) is one of the regulatory proteins controlling the transcription mechanism of gene. Biochemical experiments elucidated that the complex of CAP with cyclic AMP (cAMP) is indispensable for controlling the mechanism, while previous molecular simulations for the monomer of CAP+cAMP complex revealed the specific interactions between CAP and cAMP. However, the effect of cAMP-binding to CAP on the specific interactions between CAP and DNA is not elucidated at atomic and electronic levels. We here considered the ternary complex of CAP, cAMP and DNA in solvating water molecules and investigated the specific interactions between them at atomic and electronic levels using ab initio molecular simulations based on classical molecular dynamics and ab initio fragment molecular orbital methods. The results highlight the important amino acid residues of CAP for the interactions between CAP and cAMP and between CAP and DNA.

  2. Atomic defects in monolayer WSe2 tunneling FETs studied by systematic ab initio calculations

    Science.gov (United States)

    Wu, Jixuan; Fan, Zhiqiang; Chen, Jiezhi; Jiang, Xiangwei

    2018-05-01

    Atomic defects in monolayer WSe2 tunneling FETs (TFETs) are studied through systematic ab initio calculations aiming at performance predictions and enhancements. The effects of various defect positions and different passivation atoms are characterized in WSe2 TFETs by rigorous ab initio quantum transport simulations. It is suggested that the Se vacancy (VSe) defect located in the gate-controlled channel region tends to increase the OFF current (I off), whereas it can be well suppressed by oxygen passivation. It is demonstrated that chlorine (Cl) passivation at the source-side tunneling region can largely suppress I off, leading to an impressively improved on–off ratio (I on/I off) compared with that without any defect. However, it is also observed that randomly positioned atomic defects tend to induce significant fluctuation of the TFET output. Further discussions are made with focus on the performance-variability trade-off for robust circuit design.

  3. Bridging a gap between continuum-QCD and ab initio predictions of hadron observables

    Energy Technology Data Exchange (ETDEWEB)

    Binosi, Daniele [European Centre for Theoretical Studies in Nuclear Physics and Related Areas - ECT* and Fondazione Bruno Kessler, Villa Tambosi, Strada delle Tabarelle 286, I-38123 Villazzano (Italy); Chang, Lei [CSSM, School of Chemistry and Physics, University of Adelaide, Adelaide, SA 5005 (Australia); Papavassiliou, Joannis [Department of Theoretical Physics and IFIC, University of Valencia and CSIC, E-46100, Valencia (Spain); Roberts, Craig D., E-mail: cdroberts@anl.gov [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2015-03-06

    Within contemporary hadron physics there are two common methods for determining the momentum-dependence of the interaction between quarks: the top-down approach, which works toward an ab initio computation of the interaction via direct analysis of the gauge-sector gap equations; and the bottom-up scheme, which aims to infer the interaction by fitting data within a well-defined truncation of those equations in the matter sector that are relevant to bound-state properties. We unite these two approaches by demonstrating that the renormalisation-group-invariant running-interaction predicted by contemporary analyses of QCD's gauge sector coincides with that required in order to describe ground-state hadron observables using a nonperturbative truncation of QCD's Dyson–Schwinger equations in the matter sector. This bridges a gap that had lain between nonperturbative continuum-QCD and the ab initio prediction of bound-state properties.

  4. Explicit polarization (X-Pol) potential using ab initio molecular orbital theory and density functional theory.

    Science.gov (United States)

    Song, Lingchun; Han, Jaebeom; Lin, Yen-lin; Xie, Wangshen; Gao, Jiali

    2009-10-29

    The explicit polarization (X-Pol) method has been examined using ab initio molecular orbital theory and density functional theory. The X-Pol potential was designed to provide a novel theoretical framework for developing next-generation force fields for biomolecular simulations. Importantly, the X-Pol potential is a general method, which can be employed with any level of electronic structure theory. The present study illustrates the implementation of the X-Pol method using ab initio Hartree-Fock theory and hybrid density functional theory. The computational results are illustrated by considering a set of bimolecular complexes of small organic molecules and ions with water. The computed interaction energies and hydrogen bond geometries are in good accord with CCSD(T) calculations and B3LYP/aug-cc-pVDZ optimizations.

  5. Cardiovascular risk scores for coronary atherosclerosis.

    Science.gov (United States)

    Yalcin, Murat; Kardesoglu, Ejder; Aparci, Mustafa; Isilak, Zafer; Uz, Omer; Yiginer, Omer; Ozmen, Namik; Cingozbay, Bekir Yilmaz; Uzun, Mehmet; Cebeci, Bekir Sitki

    2012-10-01

    The objective of this study was to compare frequently used cardiovascular risk scores in predicting the presence of coronary artery disease (CAD) and 3-vessel disease. In 350 consecutive patients (218 men and 132 women) who underwent coronary angiography, the cardiovascular risk level was determined using the Framingham Risk Score (FRS), the Modified Framingham Risk Score (MFRS), the Prospective Cardiovascular Münster (PROCAM) score, and the Systematic Coronary Risk Evaluation (SCORE). The area under the curve for receiver operating characteristic curves showed that FRS had more predictive value than the other scores for CAD (area under curve, 0.76, P MFRS, PROCAM, and SCORE) may predict the presence and severity of coronary atherosclerosis.The FRS had better predictive value than the other scores.

  6. Dutch validation of the low anterior resection syndrome score.

    Science.gov (United States)

    Hupkens, B J P; Breukink, S O; Olde Reuver Of Briel, C; Tanis, P J; de Noo, M E; van Duijvendijk, P; van Westreenen, H L; Dekker, J W T; Chen, T Y T; Juul, T

    2018-04-21

    The aim of this study was to validate the Dutch translation of the low anterior resection syndrome (LARS) score in a population of Dutch rectal cancer patients. Patients who underwent surgery for rectal cancer received the LARS score questionnaire, a single quality of life (QoL) category question and the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire. A subgroup of patients received the LARS score twice to assess the test-retest reliability. A total of 165 patients were included in the analysis, identified in six Dutch centres. The response rate was 62.0%. The percentage of patients who reported 'major LARS' was 59.4%. There was a high proportion of patients with a perfect or moderate fit between the QoL category question and the LARS score, showing a good convergent validity. The LARS score was able to discriminate between patients with or without neoadjuvant radiotherapy (P = 0.003), between total and partial mesorectal excision (P = 0.008) and between age groups (P = 0.039). There was a statistically significant association between a higher LARS score and an impaired function on the global QoL subscale and the physical, role, emotional and social functioning subscales of the EORTC QLQ-C30 questionnaire. The test-retest reliability of the LARS score was good, with an interclass correlation coefficient of 0.79. The good psychometric properties of the Dutch version of the LARS score are comparable overall to the earlier validations in other countries. Therefore, the Dutch translation can be considered to be a valid tool for assessing LARS in Dutch rectal cancer patients. Colorectal Disease © 2018 The Association of Coloproctology of Great Britain and Ireland.

  7. Raman spectroscopy, ab-initio model calculations, and conformational, equilibria in ionic liquids

    OpenAIRE

    Berg, Rolf W.

    2009-01-01

    A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical results combined with vibrational spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT- Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methyl-imidazolium ...

  8. Raman Spectroscopy and Ab-Initio Model Calculations on Ionic Liquids:Invited Review

    OpenAIRE

    Berg, Rolf W.

    2007-01-01

    A review of the recent developments in the study and understanding of room temperature ionic liquids are given. An intimate picture of how and why these liquids are not crystals at ambient conditions is attempted, based on evidence from crystallographical results combined with vibrational spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([...

  9. Ab Initio theory of the Gilbert damping in random ferromagnetic alloys

    Czech Academy of Sciences Publication Activity Database

    Drchal, Václav; Turek, I.; Kudrnovský, Josef

    2017-01-01

    Roč. 30, č. 6 (2017), s. 1669-1672 ISSN 1557-1939 R&D Projects: GA ČR GA15-13436S Institutional support: RVO:68378271 Keywords : Gilbert damping * ferromagnetic alloys * ab initio * nonlocal torques Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.180, year: 2016

  10. Ab initio theory of the N2V defect in diamond for quantum memory implementation

    Science.gov (United States)

    Udvarhelyi, Péter; Thiering, Gergő; Londero, Elisa; Gali, Adam

    2017-10-01

    The N2V defect in diamond is characterized by means of ab initio methods relying on density functional theory calculated parameters of a Hubbard model Hamiltonian. It is shown that this approach appropriately describes the energy levels of correlated excited states induced by this defect. By determining its critical magneto-optical parameters, we propose to realize a long-living quantum memory by N2V defect, i.e., H 3 color center in diamond.

  11. Ab initio calculation of positron distribution, ACAR and lifetime in TTF-TCNQ

    International Nuclear Information System (INIS)

    Ishibashi, Shoji; Kohyama, Masanori

    2000-01-01

    We have performed ab initio calculations of positron distribution, ACAR and lifetime in the quasi-one-dimensional organic conductor TTF-TCNQ. The electronic structure is obtained within the LDA, while the positron state is calculated either with the LDA or with the GGA. Except the positron lifetime, differences between the LDA and GGA results are rather small. The obtained results are compared with our previous experiments and calculations.

  12. Pair potentials for alumina from ab initio results on the Al2O3 molecule

    International Nuclear Information System (INIS)

    Akdeniz, Z.; Cicek, Z.; Tosi, M.P.

    2000-08-01

    We use results from an ab initio investigation by Chang et al. on energetically low-lying stationary points of the Al 2 O 3 molecule to determine interionic potentials for the Al-O, O-O and Al-Al pairs. Our results are discussed in the perspective of previous studies of the condensed phases of alumina, with special regard to the structure of its molten state. (author)

  13. Molecular structure determination of cyclootane by ab initio and electron diffraction methods in the gas phase

    OpenAIRE

    De Almeida, Wagner B.

    2000-01-01

    The determination of the molecular structure of molecules is of fundamental importance in chemistry. X-rays and electron diffraction methods constitute in important tools for the elucidation of the molecular structure of systems in the solid state and gas phase, respectively. The use of quantum mechanical molecular orbital ab initio methods offer an alternative for conformational analysis studies. Comparison between theoretical results and those obtained experimentally in the gas phase can ma...

  14. Mechanisms for catalytic carbon nanofiber growth studied by ab initio density functional theory calculations

    DEFF Research Database (Denmark)

    Abild-Pedersen, Frank; Nørskov, Jens Kehlet; Rostrup-Nielsen, Jens

    2006-01-01

    Mechanisms and energetics of graphene growth catalyzed by nickel nanoclusters were studied using ab initio density functional theory calculations. It is demonstrated that nickel step-edge sites act as the preferential growth centers for graphene layers on the nickel surface. Carbon is transported......, and it is argued how these processes may lead to different nanofiber structures. The proposed growth model is found to be in good agreement with previous findings....

  15. Ab initio quantum-enhanced optical phase estimation using real-time feedback control

    DEFF Research Database (Denmark)

    Berni, Adriano; Gehring, Tobias; Nielsen, Bo Melholt

    2015-01-01

    of a quantum-enhanced and fully deterministic ab initio phase estimation protocol based on real-time feedback control. Using robust squeezed states of light combined with a real-time Bayesian adaptive estimation algorithm, we demonstrate deterministic phase estimation with a precision beyond the quantum shot...... noise limit. The demonstrated protocol opens up new opportunities for quantum microscopy, quantum metrology and quantum information processing....

  16. Study of carvedilol by combined Raman spectroscopy and ab initio MO calculations

    OpenAIRE

    Marques, M. P. M.; Oliveira, P. J.; Moreno, A. J. M.; Carvalho, L. A. E. Batista de

    2002-01-01

    The novel cardioprotective drug carvedilol was studied by both Raman spectroscopy and ab initio molecular orbital methods (using the density functional theory approach). The spectra, acquired both for the solid samples and DMSO solutions as a function of pH, were assigned in view of the calculated wavenumbers and intensities, and also based on the experimental data obtained for individual compounds which comprise the molecule, namely carbazole and 1,2-dimethoxybenzene. The pH dependence of th...

  17. Ab initio excited states calculations of Kr3+, probing semi-empirical modelling

    Czech Academy of Sciences Publication Activity Database

    Milko, Petr; Kalus, R.; Paidarová, Ivana; Hrušák, Jan; Gadéa, F. X.

    -, 23 June (2009), s. 25 ISSN 1432-2234 R&D Projects: GA AV ČR IAA100400501 Institutional research plan: CEZ:AV0Z40400503 Keywords : cluster modelling * rare gas ions * ab initio potential energie * evaporation energies Subject RIV: CF - Physical ; Theoretical Chemistry http://www.springerlink.com/content/100493/?Content+Status=Accepted&sort=p_OnlineDate&sortorder=desc&v=condensed&o=20

  18. Ab initio study of thermodynamic, electronic, magnetic, structural, and elastic properties of Ni4N allotropes

    Czech Academy of Sciences Publication Activity Database

    Hemzalová, P.; Friák, Martin; Šob, Mojmír; Ma, D.; Udyansky, A.; Raabe, D.; Neugebauer, J.

    2013-01-01

    Roč. 88, č. 17 (2013), Art. no. 174103 ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP108/12/0311; GA ČR GD106/09/H035; GA AV ČR IAA100100920 Institutional support: RVO:68081723 Keywords : nitrides * ab initio * thermodynamics * elasticity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.664, year: 2013

  19. Ab initio study of Co and Ni under uniaxial and biaxial loading and in epitaxial overlayers

    Czech Academy of Sciences Publication Activity Database

    Zelený, Martin; Legut, Dominik; Šob, Mojmír

    2008-01-01

    Roč. 78, č. 22 (2008), 224105/1-224105/11 ISSN 1098-0121 R&D Projects: GA ČR GD106/05/H008; GA AV ČR IAA1041302; GA MŠk OC 147 Institutional research plan: CEZ:AV0Z20410507 Keywords : ab initio calculations * epitaxial overlayers * uniaxial and biaxial loading Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

  20. The onset of ion solvation by ab initio calculations: Comparison of water and methanol

    Czech Academy of Sciences Publication Activity Database

    Pluhařová, Eva; Jungwirth, Pavel

    2008-01-01

    Roč. 73, 6/7 (2008), s. 733-744 ISSN 0010-0765 R&D Projects: GA MŠk LC512; GA ČR GA203/07/1006 Institutional research plan: CEZ:AV0Z40550506 Keywords : ions * water cluster * methanol * ab initio calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.784, year: 2008

  1. DNA oligonucleotide-cis-platin Binding: Ab initio interpretation of the vibrational spectra

    Czech Academy of Sciences Publication Activity Database

    Andrushchenko, Valery; Wieser, H.; Bouř, Petr

    2007-01-01

    Roč. 111, č. 39 (2007), s. 9714-9723 ISSN 1089-5639 R&D Projects: GA AV ČR IAA400550702; GA ČR GA202/07/0732 Institutional research plan: CEZ:AV0Z40550506 Keywords : cis - platin * DNA * vibrational spektra * ab initio Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.918, year: 2007

  2. Calibration of Sn-119 isomer shift using ab initio wave function methods

    NARCIS (Netherlands)

    Kurian, Reshmi; Filatov, Michael

    2009-01-01

    The isomer shift for the 23.87 keV M1 resonant transition in the Sn-119 nucleus is calibrated with the help of ab initio calculations. The calibration constant alpha(Sn-119) obtained from Hartree-Fock (HF) calculations (alpha(HF)(Sn-119)=(0.081 +/- 0.002)a(0)(-3) mm/s) and from second-order

  3. Advances and applications in the FIREBALL ab initio tight-binding molecular-dynamics formalism

    Czech Academy of Sciences Publication Activity Database

    Lewis, J.P.; Jelínek, Pavel; Ortega, J.; Demkov, A.A.; Trabada, D.G.; Haycock, B.; Wang, H.; Adams, G.; Tomfohr, J.K.; Abad, E.; Wang, Ho.; Drabold, D.A.

    2011-01-01

    Roč. 248, č. 9 (2011), 1989-2007 ISSN 0370-1972 R&D Projects: GA ČR GA202/09/0545; GA ČR GAP204/10/0952 Grant - others:AVČR(CZ) M100100904 Institutional research plan: CEZ:AV0Z10100521 Keywords : DFT * ab initio molecular-dynamics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.316, year: 2011

  4. Dose Uniformity of Scored and Unscored Tablets: Application of the FDA Tablet Scoring Guidance for Industry.

    Science.gov (United States)

    Ciavarella, Anthony B; Khan, Mansoor A; Gupta, Abhay; Faustino, Patrick J

    world. Tablets are often split to modify dose strength, make swallowing easier, and reduce cost to the consumer. To better address product quality for this widely used practice, the U.S. Food and Drug Administration (FDA) published a Guidance for Industry that addresses tablet splitting. The guidance provides testing criteria for scored tablets, which is a part of the FDA review process for drugs. The model drugs selected for this study were amlodipine and gabapentin, which have different sizes, shapes, and tablet scores. Whole and split amlodipine tablets were tested for drug content because of a concern that the low-dose strength may cause greater variability. Whole and split gabapentin tablets were tested for weight variation because of their higher dosage strength of 600 mg. All whole tablets met the acceptance criteria for the Uniformity of Dosage Units based on the guidance recommendations. When unscored amlodipine tablets were split by a splitter, all formulations did not meet the acceptance criteria. When fully scored gabapentin tablets were split by hand and by splitter, they met the acceptance criteria. The findings of this FDA study indicated physical characteristics such as size, shape, and tablet score can affect the uniformity of split tablets. © PDA, Inc. 2016.

  5. Interobserver variability of the neurological optimality score

    NARCIS (Netherlands)

    Monincx, W. M.; Smolders-de Haas, H.; Bonsel, G. J.; Zondervan, H. A.

    1999-01-01

    To assess the interobserver reliability of the neurological optimality score. The neurological optimality score of 21 full term healthy, neurologically normal newborn infants was determined by two well trained observers. The interclass correlation coefficient was 0.31. Kappa for optimality (score of

  6. Semiparametric score level fusion: Gaussian copula approach

    NARCIS (Netherlands)

    Susyanyo, N.; Klaassen, C.A.J.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    2015-01-01

    Score level fusion is an appealing method for combining multi-algorithms, multi- representations, and multi-modality biometrics due to its simplicity. Often, scores are assumed to be independent, but even for dependent scores, accord- ing to the Neyman-Pearson lemma, the likelihood ratio is the

  7. An Objective Fluctuation Score for Parkinson's Disease

    Science.gov (United States)

    Horne, Malcolm K.; McGregor, Sarah; Bergquist, Filip

    2015-01-01

    Introduction Establishing the presence and severity of fluctuations is important in managing Parkinson’s Disease yet there is no reliable, objective means of doing this. In this study we have evaluated a Fluctuation Score derived from variations in dyskinesia and bradykinesia scores produced by an accelerometry based system. Methods The Fluctuation Score was produced by summing the interquartile range of bradykinesia scores and dyskinesia scores produced every 2 minutes between 0900-1800 for at least 6 days by the accelerometry based system and expressing it as an algorithm. Results This Score could distinguish between fluctuating and non-fluctuating patients with high sensitivity and selectivity and was significant lower following activation of deep brain stimulators. The scores following deep brain stimulation lay in a band just above the score separating fluctuators from non-fluctuators, suggesting a range representing adequate motor control. When compared with control subjects the score of newly diagnosed patients show a loss of fluctuation with onset of PD. The score was calculated in subjects whose duration of disease was known and this showed that newly diagnosed patients soon develop higher scores which either fall under or within the range representing adequate motor control or instead go on to develop more severe fluctuations. Conclusion The Fluctuation Score described here promises to be a useful tool for identifying patients whose fluctuations are progressing and may require therapeutic changes. It also shows promise as a useful research tool. Further studies are required to more accurately identify therapeutic targets and ranges. PMID:25928634

  8. Breaking of scored tablets : a review

    NARCIS (Netherlands)

    van Santen, E; Barends, D M; Frijlink, H W

    The literature was reviewed regarding advantages, problems and performance indicators of score lines. Scored tablets provide dose flexibility, ease of swallowing and may reduce the costs of medication. However, many patients are confronted with scored tablets that are broken unequally and with

  9. Validation of Automated Scoring of Science Assessments

    Science.gov (United States)

    Liu, Ou Lydia; Rios, Joseph A.; Heilman, Michael; Gerard, Libby; Linn, Marcia C.

    2016-01-01

    Constructed response items can both measure the coherence of student ideas and serve as reflective experiences to strengthen instruction. We report on new automated scoring technologies that can reduce the cost and complexity of scoring constructed-response items. This study explored the accuracy of c-rater-ML, an automated scoring engine…

  10. Theoretical study of silicon carbide under irradiation at the nano scale: classical and ab initio modelling

    International Nuclear Information System (INIS)

    Lucas, G.

    2006-10-01

    The behaviour of silicon carbide under irradiation has been studied using classical and ab initio simulations, focusing on the nano scale elementary processes. First, we have been interested in the calculation of threshold displacement energies, which are difficult to determine both experimentally and theoretically, and also the associated Frenkel pairs. In the framework of this thesis, we have carried out simulations in classical and ab initio molecular dynamics. For the classical approach, two types of potentials have been used: the Tersoff potential, which led to non satisfactory results, and a new one which has been developed during this thesis. This potential allows a better modelling of SiC under irradiation than most of the empirical potentials available for SiC. It is based on the EDIP potential, initially developed to describe defects in silicon, that we have generalized to SiC. For the ab initio approach, the feasibility of the calculations has been validated and average energies of 19 eV for the C and 38 eV for the Si sublattices have been determined, close to the values empirically used in the fusion community. The results obtained with the new potential EDIP are globally in agreement with those values. Finally, the elementary processes involved in the crystal recovery have been studied by calculating the stability of the created Frenkel pairs and determining possible recombination mechanisms with the nudged elastic band method. (author)

  11. Materials Screening for the Discovery of New Half-Heuslers: Machine Learning versus ab Initio Methods.

    Science.gov (United States)

    Legrain, Fleur; Carrete, Jesús; van Roekeghem, Ambroise; Madsen, Georg K H; Mingo, Natalio

    2018-01-18

    Machine learning (ML) is increasingly becoming a helpful tool in the search for novel functional compounds. Here we use classification via random forests to predict the stability of half-Heusler (HH) compounds, using only experimentally reported compounds as a training set. Cross-validation yields an excellent agreement between the fraction of compounds classified as stable and the actual fraction of truly stable compounds in the ICSD. The ML model is then employed to screen 71 178 different 1:1:1 compositions, yielding 481 likely stable candidates. The predicted stability of HH compounds from three previous high-throughput ab initio studies is critically analyzed from the perspective of the alternative ML approach. The incomplete consistency among the three separate ab initio studies and between them and the ML predictions suggests that additional factors beyond those considered by ab initio phase stability calculations might be determinant to the stability of the compounds. Such factors can include configurational entropies and quasiharmonic contributions.

  12. Ab initio and empirical studies on the asymmetry of molecular current-voltage characteristics

    International Nuclear Information System (INIS)

    Hoft, R C; Armstrong, N; Ford, M J; Cortie, M B

    2007-01-01

    We perform theoretical calculations of the tunnelling current through various small organic molecules sandwiched between gold electrodes by using both a tunnel barrier model and an ab initio transport code. The height of the tunnelling barrier is taken to be the work function of gold as modified by the adsorbed molecule and calculated from an ab initio electronic structure code. The current-voltage characteristics of these molecules are compared. Asymmetry is introduced into the system in two ways: an asymmetric molecule and a gap between the molecule and the right electrode. The latter is a realistic situation in scanning probe experiments. The asymmetry is also realized in the tunnel barrier model by two distinct work functions on the left and right electrodes. Significant asymmetry is observed in the ab initio i(V) curves. The tunnel barrier i(V) curves show much less pronounced asymmetry. The relative sizes of the currents through the molecules are compared. In addition, the performance of the WKB approximation is compared to the results obtained from the exact Schroedinger solution to the tunnelling barrier problem

  13. Dominant Modes in Light Nuclei - Ab Initio View of Emergent Symmetries

    International Nuclear Information System (INIS)

    Draayer, J P; Dytrych, T; Launey, K D; Dreyfuss, A C; Langr, D

    2015-01-01

    An innovative symmetry-guided concept is discussed with a focus on emergent symmetry patterns in complex nuclei. In particular, the ab initio symmetry-adapted no-core shell model (SA-NCSM), which capitalizes on exact as well as partial symmetries that underpin the structure of nuclei, provides remarkable insight into how simple symmetry patterns emerge in the many-body nuclear dynamics from first principles. This ab initio view is complemented by a fully microscopic no-core symplectic shell-model framework (NCSpM), which, in turn, informs key features of the primary physics responsible for the emergent phenomena of large deformation and alpha-cluster substructures in studies of the challenging Hoyle state in Carbon-12 and enhanced collectivity in intermediate-mass nuclei. Furthermore, by recognizing that deformed configurations often dominate the low-energy regime, the SA-NCSM provides a strategy for determining the nature of bound states of nuclei in terms of a relatively small subspace of the symmetry-reorganized complete model space, which opens new domains of nuclei for ab initio investigations, namely, the intermediate-mass region, including isotopes of Ne, Mg, and Si

  14. Thermal transport in nanocrystalline Si and SiGe by ab initio based Monte Carlo simulation.

    Science.gov (United States)

    Yang, Lina; Minnich, Austin J

    2017-03-14

    Nanocrystalline thermoelectric materials based on Si have long been of interest because Si is earth-abundant, inexpensive, and non-toxic. However, a poor understanding of phonon grain boundary scattering and its effect on thermal conductivity has impeded efforts to improve the thermoelectric figure of merit. Here, we report an ab-initio based computational study of thermal transport in nanocrystalline Si-based materials using a variance-reduced Monte Carlo method with the full phonon dispersion and intrinsic lifetimes from first-principles as input. By fitting the transmission profile of grain boundaries, we obtain excellent agreement with experimental thermal conductivity of nanocrystalline Si [Wang et al. Nano Letters 11, 2206 (2011)]. Based on these calculations, we examine phonon transport in nanocrystalline SiGe alloys with ab-initio electron-phonon scattering rates. Our calculations show that low energy phonons still transport substantial amounts of heat in these materials, despite scattering by electron-phonon interactions, due to the high transmission of phonons at grain boundaries, and thus improvements in ZT are still possible by disrupting these modes. This work demonstrates the important insights into phonon transport that can be obtained using ab-initio based Monte Carlo simulations in complex nanostructured materials.

  15. Proper construction of ab initio global potential surfaces with accurate long-range interactions

    International Nuclear Information System (INIS)

    Ho, Tak-San; Rabitz, Herschel

    2000-01-01

    An efficient procedure based on the reproducing kernel Hilbert space interpolation method is presented for constructing intermolecular potential energy surfaces (PES) using not only calculated ab initio data but also a priori information on long-range interactions. Explicitly, use of the reciprocal power reproducing kernel on the semiinfinite interval [0,∞) yields a set of exact linear relations between dispersion (multipolar) coefficients and PES data points at finite internuclear separations. Consequently, given a combined set of ab initio data and the values of dispersion (multipolar) coefficients, the potential interpolation problem subject to long-range interaction constraints can be solved to render globally smooth, asymptotically accurate ab initio potential energy surfaces. Very good results have been obtained for the one-dimensional He-He potential curve and the two-dimensional Ne-CO PES. The construction of the Ne-CO PES was facilitated by invoking a new reproducing kernel for the angular coordinate based on the optimally stable and shape-preserving Bernstein basis functions. (c) 2000 American Institute of Physics

  16. Common lines modeling for reference free Ab-initio reconstruction in cryo-EM.

    Science.gov (United States)

    Greenberg, Ido; Shkolnisky, Yoel

    2017-11-01

    We consider the problem of estimating an unbiased and reference-free ab initio model for non-symmetric molecules from images generated by single-particle cryo-electron microscopy. The proposed algorithm finds the globally optimal assignment of orientations that simultaneously respects all common lines between all images. The contribution of each common line to the estimated orientations is weighted according to a statistical model for common lines' detection errors. The key property of the proposed algorithm is that it finds the global optimum for the orientations given the common lines. In particular, any local optima in the common lines energy landscape do not affect the proposed algorithm. As a result, it is applicable to thousands of images at once, very robust to noise, completely reference free, and not biased towards any initial model. A byproduct of the algorithm is a set of measures that allow to asses the reliability of the obtained ab initio model. We demonstrate the algorithm using class averages from two experimental data sets, resulting in ab initio models with resolutions of 20Å or better, even from class averages consisting of as few as three raw images per class. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Modeling of nuclear glasses by classical and ab initio molecular dynamics

    International Nuclear Information System (INIS)

    Ganster, P.

    2004-01-01

    A calcium aluminosilicate glass of molar composition 67 % SiO 2 - 12 % Al 2 O 3 - 21 % CaO was modelled by classical and ab initio molecular dynamics. The size effect study in classical MD shows that the systems of 100 atoms are more ordered than the larger ones. These effects are mainly due to the 3-body terms in the empirical potentials. Nevertheless, these effects are small and the structures generated are in agreement with experimental data. In such kind of glass, we denote an aluminium avoidance and an excess of non bridging oxygens which can be compensated by tri-coordinated oxygens. When the dynamics of systems of 100 and 200 atoms is followed by ab initio MD, some local arrangements occurs (bond length, angular distributions). Thus, more realistic vibrational properties are obtained in ab initio MD. The modelling of thin films shows that aluminum atoms extend to the most external part of the surface and they are all tri-coordinated. Calcium atoms are set in the sub layer part of the surface and they produce a depolymerization of the network. In classical MD, tri-coordinated aluminium atoms produce an important electric field above the surface. With non bridging oxygens, they constitute attractive sites for single water molecules. (author) [fr

  18. Modelling of nuclear glasses by classical and ab initio molecular dynamics

    International Nuclear Information System (INIS)

    Ganster, P.

    2004-10-01

    A calcium aluminosilicate glass of molar composition 67 % SiO 2 - 12 % Al 2 O 3 - 21 % CaO was modelled by classical and ab initio molecular dynamics. The size effect study in classical MD shows that the systems of 100 atoms are more ordered than the larger ones. These effects are mainly due to the 3-body terms in the empirical potentials. Nevertheless, these effects are small and the structures generated are in agreement with experimental data. In such kind of glass, we denote an aluminium avoidance and an excess of non bridging oxygens which can be compensated by tri coordinated oxygens. When the dynamics of systems of 100 and 200 atoms is followed by ab initio MD, some local arrangements occurs (bond length, angular distributions). Thus, more realistic vibrational properties are obtained in ab initio MD. The modelling of thin films shows that aluminium atoms extend to the most external part of the surface and they are all tri-coordinated. Calcium atoms are set in the sub layer part of the surface and they produce a depolymerization of the network. In classical MD, tri-coordinated aluminium atoms produce an important electric field above the surface. With non bridging oxygens, they constitute attractive sites for single water molecules. (author)

  19. Ab Initio Predictions of Hexagonal Zr(B,C,N) Polymorphs for Coherent Interface Design

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chongze [Univ. of Minnesota-Twin Cities, Minneapolis, MN (United States); Huang, Jingsong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sumpter, Bobby G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Meletis, Efstathios [Univ. of Texas at Arlington, Arlington, TX (United States); Dumitrica, Traian [Univ. of Minnesota-Twin Cities, Minneapolis, MN (United States)

    2017-10-27

    Density functional theory calculations are used to explore hexagonal (HX) NiAs-like polymorphs of Zr(B,C,N) and compare with corresponding Zr(B,C,N) Hagg-like face-centered cubic rocksalt (B1) phases. While all predicted compounds are mechanically stable according to the Born-Huang criteria, only HX Zr(C,N) are found dynamically stable from ab initio molecular dynamics simulations and lattice dynamics calculations. HX ZrN emerges as a candidate structure with ground state energy, elastic constants, and extrinsic mechanical parameters comparable with those of B1 ZrN. Ab initio band structure and semi-classical Boltzmann transport calculations predict a metallic character and a monotonic increase in electrical conductivity with the number of valence electrons. Electronic structure calculations indicate that the HX phases gain their stability and mechanical attributes by Zr d- non-metal p hybridization and by broadening of Zr d bands. Furthermore, it is shown that the HX ZrN phase provides a low-energy coherent interface model for connecting B1 ZrN domains, with significant energetic advantage over an atomistic interface model derived from high resolution transmission electron microscopy images. The ab initio characterizations provided herein should aid the experimental identification of non-Hagg-like hard phases. Furthermore, the results can also enrich the variety of crystalline phases potentially available for designing coherent interfaces in superhard nanostructured materials and in materials with multilayer characteristics.

  20. Disease scoring systems for oral lichen planus; a critical appraisal

    Science.gov (United States)

    Wang, Jing

    2015-01-01

    The aim of the present study has been to critically review 22 disease scoring systems (DSSs) on oral lichen planus (OLP) that have been reported in the literature during the past decades. Although the presently available DSSs may all have some merit, particularly for research purposes, the diversity of both the objective and subjective parameters used in these systems and the lack of acceptance of one of these systems for uniform use, there is a need for an international, authorized consensus meeting on this subject. Because of the natural course of OLP characterized by remissions and exacerbations and also due to the varying distribution pattern and the varying clinical types, e.g. reticular and erosive, the relevance of a DSS based on morphologic parameters is somewhat questionable. Instead, one may consider to only look for a quality of life scoring system adapted for use in OLP patients. Key words:Oral lichen planus, disease scoring system, classification. PMID:25681372