277 research outputs found
Quantitative comparison of filtering methods in lattice QCD
We systematically compare filtering methods used to extract topological
excitations (like instantons, calorons, monopoles and vortices) from lattice
gauge configurations, namely APE-smearing and spectral decompositions based on
lattice Dirac and Laplace operators. Each of these techniques introduces
ambiguities, which can invalidate the interpretation of the results. We show,
however, that all these methods, when handled with care, reveal very similar
topological structures. Hence, these common structures are free of ambiguities
and faithfully represent infrared degrees of freedom in the QCD vacuum. As an
application we discuss an interesting power-law for the clusters of filtered
topological charge.Comment: 6 pages, 18 plots in 5 figures; final version as published in EPJ A;
section 4 was adde
Characterization and application of artificial light sources for nighttime aerosol optical depth retrievals using the Visible Infrared Imager Radiometer Suite Day/Night Band
Using nighttime observations from Visible Infrared Imager Radiometer Suite (VIIRS) Day/Night band (DNB), the characteristics of artificial light sources are evaluated as functions of observation conditions, and incremental improvements are documented on nighttime aerosol retrievals using VIIRS DNB data on a regional scale. We find that the standard deviation of instantaneous radiance for a given artificial light source is strongly dependent upon the satellite viewing angle but is weakly dependent on lunar fraction and lunar angle. Retrieval of nighttime aerosol optical thickness (AOT) based on the novel use of these artificial light sources is demonstrated for three selected regions (United States, Middle East and India) during 2015. Reasonable agreement is found between nighttime AOTs from the VIIRS DNB and temporally adjacent daytime AOTs from the AErosol RObotic NETwork (AERONET) as well as from coincident nighttime AOT retrievals from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), indicating the potential of this method to begin filling critical gaps in diurnal AOT information at both regional and global scales. Issues related to cloud, snow and ice contamination during the winter season, as well as data loss due to the misclassification of thick aerosol plumes as clouds, must be addressed to make the algorithm operationally robust
Using shape expressions (ShEx) to share rdf data models and to guide curation with rigorous validation
International Conference, European Semantic Web Conference, ESWC (16th. 2019. Portorož, Slovenia
The researcher Toolkit: A preventative, peer-support approach to postgraduate research student mental health
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Vacuum structure revealed by over-improved stout-link smearing compared with the overlap analysis for quenched QCD
A detailed comparison is made between the topological structure of quenched
QCD as revealed by the recently proposed over-improved stout-link smearing in
conjunction with an improved gluonic definition of the topological density on
one hand and a similar analysis made possible by the overlap-fermionic
topological charge density both with and without variable ultraviolet cutoff
. The matching is twofold, provided by fitting the
density-density two-point functions on one hand and by a point-by-point fitting
of the topological densities according to the two methods. We point out the
similar cluster structure of the topological density for moderate smearing and
, respectively. We
demonstrate the relation of the gluonic topological density for extensive
smearing to the location of the overlap zero modes and the lowest overlap
non-zero mode as found for the unsmeared configurations.Comment: 19 pages, 18 figure
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PYROPROCESSING PROGRESS AT IDAHO NATIONAL LABORATORY
At the end of May 2007, 830 and 2600 kilograms of EBR-II driver and blanket metal fuel have been treated by a pyroprocess since spent fuel operations began in June 1996. A new metal waste furnace has completed out-of-cell testing and is being installed in the Hot Fuel Examination Facility. Also, ceramic waste process development and qualification is progressing so integrated nuclear fuel separations and high level waste processes will exist at Idaho National Laboratory. These operations have provided important scale-up and performance data on engineering scale operations. Idaho National Laboratory is also increasing their laboratory scale capabilities so new process improvements and new concepts can be tested before implementation at engineering scale. This paper provides an overview of recent achievements and provides the interested reader references for more details
Borna disease virus (BDV) circulating immunocomplex positivity in addicted patients in the Czech Republic: a prospective cohort analysis
<p>Abstract</p> <p>Background</p> <p>Borna disease virus (BDV) is an RNA virus belonging to the family Bornaviridae. Borna disease virus is a neurotropic virus that causes changes in mood, behaviour and cognition. BDV causes persistent infection of the central nervous system. Immune changes lead to activation of infection. Alcohol and drug dependence are associated with immune impairment.</p> <p>Methods</p> <p>We examined the seropositivity of BDV circulating immunocomplexes (CIC) in patients with alcohol and drug dependence and healthy individuals (blood donors). We examined 41 addicted patients for the presence of BDV CIC in the serum by ELISA at the beginning of detoxification, and after eight weeks of abstinence. This is the first such study performed in patients with alcohol and drug dependence.</p> <p>Results</p> <p>BDV CIC positivity was detected in 36.59% of addicted patients on day 0 and in 42.86% on day 56. The control group was 37.3% positive. However, we did not detect higher BDV CIC positivity in addicted patients in comparison with blood donors (p = 0.179). The significantly higher level of BDV CIC was associated with lower levels of GGT (gamma glutamyl transferase) (p = 0.027) and approached statistical significance with the lower age of addicted patients (p = 0.064). We did not find any association between BDV CIC positivity and other anamnestic and demographic characteristics.</p> <p>Conclusions</p> <p>In our study addicted patients did not have significantly higher levels of BDV CIC than the control group. The highest levels of BDV CIC were detected in patients with lower levels of GGT and a lower age.</p> <p>Trial registration</p> <p>This study was approved by the ethical committee of the University Hospital Medical Faculty of Charles University in Pilsen, Czech Republic (registration number 303/2001).</p
A multi-source data integration approach reveals novel associations between metabolites and renal outcomes in the German Chronic Kidney Disease study
Omics data facilitate the gain of novel insights into the pathophysiology of diseases and, consequently, their diagnosis, treatment, and prevention. To this end, omics data are integrated with other data types, e.g., clinical, phenotypic, and demographic parameters of categorical or continuous nature. We exemplify this data integration issue for a chronic kidney disease (CKD) study, comprising complex clinical, demographic, and one-dimensional H-1 nuclear magnetic resonance metabolic variables. Routine analysis screens for associations of single metabolic features with clinical parameters while accounting for confounders typically chosen by expert knowledge. This knowledge can be incomplete or unavailable. We introduce a framework for data integration that intrinsically adjusts for confounding variables. We give its mathematical and algorithmic foundation, provide a state-of-the-art implementation, and evaluate its performance by sanity checks and predictive performance assessment on independent test data. Particularly, we show that discovered associations remain significant after variable adjustment based on expert knowledge. In contrast, we illustrate that associations discovered in routine univariate screening approaches can be biased by incorrect or incomplete expert knowledge. Our data integration approach reveals important associations between CKD comorbidities and metabolites, including novel associations of the plasma metabolite trimethylamine-N-oxide with cardiac arrhythmia and infarction in CKD stage 3 patients
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