13,961 research outputs found
Measuring Accuracy of Triples in Knowledge Graphs
An increasing amount of large-scale knowledge graphs have been constructed in recent years. Those graphs are often created from text-based extraction, which could be very noisy. So far, cleaning knowledge graphs are often carried out by human experts and thus very inefficient. It is necessary to explore automatic methods for identifying and eliminating erroneous information. In order to achieve this, previous approaches primarily rely on internal information i.e. the knowledge graph itself. In this paper, we introduce an automatic approach, Triples Accuracy Assessment (TAA), for validating RDF triples (source triples) in a knowledge graph by finding consensus of matched triples (among target triples) from other knowledge graphs. TAA uses knowledge graph interlinks to find identical resources and apply different matching methods between the predicates of source triples and target triples. Then based on the matched triples, TAA calculates a confidence score to indicate the correctness of a source triple. In addition, we present an evaluation of our approach using the FactBench dataset for fact validation. Our findings show promising results for distinguishing between correct and wrong triples
An investigation of the occurrence of sv40 antibodies in South Africa
We developed an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to simian virus 40 (SV40) in human serum. We then used the ELISA to test for anti-SV40 antibodies in healthy inviduals and patients suffering from cancer and renal diseases. The aim of the study was to determine the presence of antibodies against SV40 in sera of individuals who received the South African poliovirus vaccines from 1958 to the present. Detecting such antibodies could give an indication of whether any of the poliovirus vaccines used in South Africa were ever contaminated with the SV40 or not. A total of 5/164 samples were repeatedly positive for SV40 antibodies by the ELISA. Four of the samples were from the healthy population group and the remaining 1 (1/64) was from the patient group. An SV40 antibody-blocking assay and a Western blot were used as additional confirmation for the SV40 antibodies, whereas the Western blot assay developed a single common band on all 5 samples
Anisotropic thermal expansion and magnetostriction of YNiBC single crystals
We present results of anisotropic thermal expansion and low temperature
magnetostriction measurements on YNiBC single crystals grown by high
temperature flux and floating zone techniques. Quantum oscillations of
magnetostriction were observed at low temperatures for starting at
fields significantly below (). Large irreversible,
longitudinal magnetostriction was seen in both, in-plane and along the c-axis,
directions of the applied magnetic field in the intermediate superconducting
state. Anisotropic uniaxial pressure dependencies of were evaluated using
results of zero field, thermal expansion measurements
On the Deconfinement Phase Transition in the Resonance Gas
We obtain the constraints on the ruling parameters of the dense hadronic gas
model at the critical temperature and propose the quasiuniversal ratios of the
thermodynamic quantities. The possible appearence of thermodynamical
instability in such a model is discussed.Comment: 7 pages, plain LaTeX, BI-TP 94/4
Entrainment rates and microphysics in POST stratocumulus
The article of record as published may be located at http://dx.doi.org/10.1002/jgrd.50878An aircraft field study (POST; Physics of Stratocumulus Top) was conducted off the
central California coast in July and August 2008 to deal with the known difficulty of
measuring entrainment rates in the radiatively important stratocumulus (Sc) prevalent in that
area. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter
research aircraft flew 15 quasi-Lagrangian flights in unbroken Sc and carried a full
complement of probes including three high-data-rate probes: ultrafast temperature probe,
particulate volume monitor probe, and gust probe. The probes’ colocation near the nose of
the Twin Otter permitted estimation of entrainment fluxes and rates with an in-cloud
resolution of 1m. Results include the following: Application of the conditional sampling
variation of classical mixed layer theory for calculating the entrainment rate into cloud top
for POST flights is shown to be inadequate for most of the Sc. Estimated rates resemble
previous results after theory is modified to take into account both entrainment and
evaporation at cloud top given the strong wind shear and mixing at cloud top. Entrainment
rates show a tendency to decrease for large shear values, and the largest rates are for the
smallest temperature jumps across the inversion. Measurements indirectly suggest that
entrained parcels are primarily cooled by infrared flux divergence rather than cooling from
droplet evaporation, while detrainment at cloud top causes droplet evaporation and cooling
in the entrainment interface layer above cloud top.NSF supported H. Gerber, G. Frick, and S. Malinowski (ATM-0735121, AGS-1020445), D. Khelif (ATM-0734323), and S. Krueger (ATM-0735118). The Office of Naval Research and the Naval Postgraduate School supported in part the deployment of the Twin Otter aircraft
Van der Waals forces in density functional theory: perturbational long-range electron interaction corrections
Long-range exchange and correlation effects, responsible for the failure of
currently used approximate density functionals in describing van der Waals
forces, are taken into account explicitly after a separation of the
electron-electron interaction in the Hamiltonian into short- and long-range
components. We propose a "range-separated hybrid" functional based on a local
density approximation for the short-range exchange-correlation energy, combined
with a long-range exact exchange energy. Long-range correlation effects are
added by a second-order perturbational treatment. The resulting scheme is
general and is particularly well-adapted to describe van der Waals complexes,
like rare gas dimers.Comment: 8 pages, 1 figure, submitted to Phys. Rev.
“Learning on a chip:” Microfluidics for formal and informal science education
© 2019 Author(s). Microfluidics is a technique for the handling of small volumes of liquids on the order of picoliters to nanoliters and has impact for miniaturized biomedical science and fundamental research. Because of its multi- and interdisciplinary nature (i.e., combining the fields of biology, chemistry, physics, and engineering), microfluidics offers much potential for educational applications, both at the university level as well as primary and secondary education. Microfluidics is also an ideal "tool" to enthuse and educate members of the general public about the interdisciplinary aspects of modern sciences, including concepts of science, technology, engineering, and mathematics subjects such as (bio)engineering, chemistry, and biomedical sciences. Here, we provide an overview of approaches that have been taken to make microfluidics accessible for formal and informal learning. We also point out future avenues and desired developments. At the extreme ends, we can distinguish between projects that teach how to build microfluidic devices vs projects that make various microscopic phenomena (e.g., low Reynolds number hydrodynamics, microbiology) accessible to learners and the general public. Microfluidics also enables educators to make experiments low-cost and scalable, and thereby widely accessible. Our goal for this review is to assist academic researchers working in the field of microfluidics and lab-on-a-chip technologies as well as educators with translating research from the laboratory into the lecture hall, teaching laboratory, or public sphere
Pion propagation in real time field theory at finite temperature
We describe how the thermal counterpart of a vacuum two-point function may be
obtained in the real time formalism in a simple way by using directly the
matrices that different elements acquire in this formalism. Using
this procedure we calculate the analytic (single component) thermal amplitude
for the pion pole term in the ensemble average of two axial-vector currents to
two loops in chiral perturbation theory. The general expressions obtained for
the effective mass and decay constants of the pion are evaluated in the chiral
and the nonrelativistic limits. We also investigate the effect of massive
states on these effective parameters.Comment: 17 pages TeX and 9 eps figure
Morphological Abnormalities in Vitamin B6 Deficient Tarsometatarsal Chick Cartilage
The aim of this study was to test the hypothesis that deficiency of vitamin B6 would produce morphological characteristics of osteochondral lathyrism. To accomplish this goal, morphological characteristics of chick cartilage in which lathyrism was produced by two separate dietary regimens was compared to morphological changes encountered in vitamin B6 deficiency. Vitamin B6 deficiency should reduce activity of lysyloxidase needed for producing intermolecular cross-links. The question to be addressed was: would this latter deficiency impair collagen morphological features and secondarily other structures indirectly by reducing collagen molecular assembly? Failure of cross-linking of collagen in the positive controls was related to a lack of functional aldehyde cross-link intermediates which are blocked by homocysteine and aminoacetonitrile.
Day-old-male Lohmann chicks were fed adequate (6 mg/kg) or vitamin B6-deficient diets. Cross-link defects were induced by homocysteine-rich diets (0.6% w/w) or a diet containing aminoacetonitrile (0.1% w/w). Animals were sacrificed at 6 weeks of age and Ossa tarsalia articular cartilage specimens, as well as the proximal end of tarsometatarsus were dissected from the tibial metatarsal joint, a major weight-bearing site. Light microscopic observations revealed reduction of subarticular trabecular bone formation, concurrent with overexpansion of the hypertrophic cell zone. Ultrastructural electron microscopy observations of articular fibro-cartilage indicated significant thickening of collagen fibers in vitamin B6 deficient birds, as well as the positive controls in comparison to that of cage-matched control birds. It was concluded that vitamin B6 deficient cross-linking may be responsible for the observed delay in bone development and aforementioned cartilage histological alterations
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