788 research outputs found
Towards OWL-based Knowledge Representation in Petrology
This paper presents our work on development of OWL-driven systems for formal
representation and reasoning about terminological knowledge and facts in
petrology. The long-term aim of our project is to provide solid foundations for
a large-scale integration of various kinds of knowledge, including basic terms,
rock classification algorithms, findings and reports. We describe three steps
we have taken towards that goal here. First, we develop a semi-automated
procedure for transforming a database of igneous rock samples to texts in a
controlled natural language (CNL), and then a collection of OWL ontologies.
Second, we create an OWL ontology of important petrology terms currently
described in natural language thesauri. We describe a prototype of a tool for
collecting definitions from domain experts. Third, we present an approach to
formalization of current industrial standards for classification of rock
samples, which requires linear equations in OWL 2. In conclusion, we discuss a
range of opportunities arising from the use of semantic technologies in
petrology and outline the future work in this area.Comment: 10 pages. The paper has been accepted by OWLED2011 as a long
presentatio
Restrictions on local embeddability into finite semigroups
In this paper the concept of local embeddability into finite structures
(being LEF) for the class of semigroups is expanded with investigations of
non-LEF structures, a closely related generalising property of local wrapping
of finite structures (being LWF) and inverse semigroups. The established
results include a description of a family of non-LEF semigroups unifying the
bicyclic monoid and Baumslag--Solitar groups and establishing that inverse LWF
semigroups with finite number of idempotents are LEF.Comment: 19 page
Using ORG-Master for Knowledge Based Organizational Change
* Under Knowledge Infrastructure we imply all the means that enable effective knowledge management within
organization ~ knowledge process support.Enterprises in growing markets with transitional economy nowadays encounter extreme necessity to
change their structures and improve business processes. In order to support knowledge processes within
organizational change initiative enterprises can use business modeling tools. On one hand software vendors
suggest many tools of this kind, but on the other hand growing markets with transitional economy determine quite
special requirements for such tools. This article reveals these requirements, assesses existing business modeling
tools using these requirements and describes ORG-Master as a tool specially created for support of process
improvement initiatives in the growing markets with transitional economy
The extraordinary complex magnetic field of the helium-strong star HD 37776
The early-type chemically peculiar stars often show strong magnetic fields on
their surfaces. These magnetic topologies are organized on large scales and are
believed to be close to an oblique dipole for most of the stars. In a striking
exception to this general trend, the helium-strong star HD 37776 shows an
extraordinary double-wave rotational modulation of the longitudinal magnetic
field measurements, indicating a topologically complex and, possibly, record
strong magnetic field. Here we present a new investigation of the magnetic
field structure of HD 37776, using both simple geometrical interpretation of
the longitudinal field curve and detailed modeling of the time-resolved
circular polarization line profiles with the help of magnetic Doppler imaging
technique. We derive a model of the magnetic field structure of HD 37776, which
reconciles for the first time all magnetic observations available for this
star. We find that the local surface field strength does not exceed ~30 kG,
while the overall field topology of HD 37776 is dominated by a non-axisymmetric
component and represents by far the most complex magnetic field configuration
found among early-type stars.Comment: 9 pages, 8 figures; accepted for publication in The Astrophysical
Journa
Spectropolarimetry of Magnetic Chemically Peculiar Stars in the Orion OB1 Association
We summarise the results of a spectropolarimetric survey of 56 chemically
peculiar (CP) stars in the association of Orion OB1. We uniformly collected the
observational material with the 6-m telescope BTA of the Special Astrophysical
Observatory in 2013-2021. We identify 14 new magnetic CP stars with a
longitudinal magnetic field exceeding approximately 500 G. The studied sample
contains 31 magnetic stars or 55% of the whole CP population in Orion OB1. We
show that the percentage of the magnetic CP stars and the field strength drops
sharply with age. The mean longitudinal magnetic field in the young subgroup
OB1b () is confidently almost three times stronger than in the
older subgroups OB1a () and OB1c (). In the Orion
Nebula, a place with the youngest stellar population (), we
detect the magnetic field only in 20% of CP stars. Such occurrence drastically
differs from 83% of magnetic CP stars in the nearby subgroup OB1c. We consider
this effect an observational bias caused by a significant portion of a very
young population with the signatures of Herbig Ae/Be stars. The technique we
used for magnetic measurements, and the quality of available data do not allow
us to detect weak fields in the case of stars with a limited number of lines
and emissions in spectra.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical
Society Main Journal. Contains 14 pages, 11 figure
АНАЛИЗ ВЛИЯНИЯ ВСТУПЛЕНИЯ РОССИИ ВО ВСЕМИРНУЮ ТОРГОВУЮ ОРГАНИЗАЦИЮ НА МАЛЫЙ И СРЕДНИЙ БИЗНЕС
This article consideres influence on small and medium enterprises of membership of the Russian Federation in the World Trade Organization. SWOT matrix is offered as the tool of the analysis risk.В данной статье оценивается влияние вступления Российской Федерации во Всемирную торговую организацию на малый и средней бизнес. Как инструмент анализа риска предложена матрица SWOT
Rarefaction and Non-equilibrium Effects in Hypersonic Flows about Leading Edges of Small Bluntness
Abstract. A hypersonic flow about a cylindrically blunted thick plate at a zero angle of attack is numerically studied with the kinetic (DSMC) and continuum (Navier-Stokes equations) approaches. The Navier-Stokes equations with velocity slip and temperature jump boundary conditions correctly predict the flow fields and surface parameters for values of the Knudsen number (based on the radius of leading edge curvature) smaller than 0.1. The results of computations demonstrate significant effects of the entropy layer on the boundary layer characteristics
Molecular and Cellular Mechanisms of M. tuberculosis and SARS-CoV-2 Infections-Unexpected Similarities of Pathogenesis and What to Expect from Co-Infection
Tuberculosis is still an important medical and social problem. In recent years, great strides have been made in the fight against M. tuberculosis, especially in the Russian Federation. However, the emergence of a new coronavirus infection (COVID-19) has led to the long-term isolation of the population on the one hand and to the relevance of using personal protective equipment on the other. Our knowledge regarding SARS-CoV-2-induced inflammation and tissue destruction is rapidly expanding, while our understanding of the pathology of human pulmonary tuberculosis gained through more the 100 years of research is still limited. This paper reviews the main molecular and cellular differences and similarities caused by M. tuberculosis and SARS-CoV-2 infections, as well as their critical immunological and pathomorphological features. Immune suppression caused by the SARS-CoV-2 virus may result in certain difficulties in the diagnosis and treatment of tuberculosis. Furthermore, long-term lymphopenia, hyperinflammation, lung tissue injury and imbalance in CD4+ T cell subsets associated with COVID-19 could propagate M. tuberculosis infection and disease progression
Identification of autoimmune markers in pulmonary tuberculosis
IntroductionPathogenesis of many autoimmune diseases is mainly promoted by poorly regulated and/or wrong targeted immune response to pathogens including M. tuberculosis. Autoimmunity is one of the processes with are characteristics of tuberculosis (Tbc). The aim was to determine the autoimmune clinical and immunological features in patients with pulmonary Tbc.Materials and methodsA prospective comparative study was performed in 2017 – 2019 with the inclusion of 46 patients with Tbc. The trigger factors and clinical manifestations, autoantibodies, peripheral blood B cell subsets were stained with fluorochrome-conjugated monoclonal antibodies. 40 healthy volunteers in the control group, were matched for age with no chronic diseases, contacts with TB patients and changes in their laboratory parameters. A statistical analysis was done with GraphPad Prism 6, Statistica 10 (Statsoft) and MedCalc – version 18.2.1 values.ResultsThere were no significant ASIA triggers in Tbc patients and control group. 21.1% of Tbc patients had a high level of a rheumatoid factor and in 47.4% complement system factor C3 was high; anti-MCV was detected in 60.7% of Tbc patients. Relative and absolute frequencies of “naïve” Bm1 cells and eBm5 were significantly decreased and activated pre-germinal-center Bm2’ cells were significantly increased in Tbc patients. The CD24++CD38++ B cells were increased in Tbc vs control group (10.25% vs 5.42%), p < 0.001, and 19 cell/1μL (10; 290 vs 11 cell/1μL (6; 20), p = 0.029, respectively). The frequency of CXCR3+CCR4– Tfh1 cells was significantly lower in Tbc vs control one (26.52% vs. 31.00%, p = 0.004), while CXCR3–CCR4+ Tfh2 cells were increased in Tbc (20.31% vs. controls (16.56%, p = 0.030). The absolute numbers of Tfh1 cells were decreased in the Tbc vs. control (24 cell/1μL vs. 37 cell/1μL p = 0.005).ConclusionThe results of our study showed that the detection of a rheumatoid factor, the components of complement system and anti-MCV in complex with alterations in B cells and follicular Th cell subsets may indicate a presence of autoimmunity in the pathogenesis of tuberculosis, but they are not specific. The indicators of autoimmune-related provide new opportunities in the Tbc treatment
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