91 research outputs found
Homology class of a Lagrangian Klein bottle
It is shown that an embedded Lagrangian Klein bottle represents a non-trivial
mod 2 homology class in a compact symplectic four-manifold with
. (In versions 1 and 2, the last assumption was missing.
A counterexample to this general claim and the first proof of the corrected
result have been found by Vsevolod Shevchishin.) As a corollary one obtains
that the Klein bottle does not admit a Lagrangian embedding into the standard
symplectic four-space.Comment: Version 3 - completely rewritten to correct a mistake; Version 4 -
minor edits, added references; AMSLaTeX, 6 page
A search for disordered (glassy) phase in solid 3He deformed in situ
A disordered (glassy) state has been searched in solid 3He deformed in the
course of experiment employing precise measurements of pressure. The analysis
of the temperature dependence of the crystal pressure measured at a constant
volume shows that the main contribution to the pressure is made by the phonon
subsystem, the influence of the disordered phase being very weak. Annealing of
the deformed crystal does not affect this state. The results obtained differ
greatly from the corresponding data for solid 4He measured in the region of
supersolid effects where a pressure excessive in comparison to the phonon one
was registered. The excess pressure had a quadratic dependence on temperature,
which is typical of a disordered system. Absence of the excess pressure in
solid 3He is unclear yet, some speculative interpretations are suggested.Comment: 9 pages, 4 figure
Flux-splitting schemes for parabolic problems
To solve numerically boundary value problems for parabolic equations with
mixed derivatives, the construction of difference schemes with prescribed
quality faces essential difficulties. In parabolic problems, some possibilities
are associated with the transition to a new formulation of the problem, where
the fluxes (derivatives with respect to a spatial direction) are treated as
unknown quantities. In this case, the original problem is rewritten in the form
of a boundary value problem for the system of equations in the fluxes. This
work deals with studying schemes with weights for parabolic equations written
in the flux coordinates. Unconditionally stable flux locally one-dimensional
schemes of the first and second order of approximation in time are constructed
for parabolic equations without mixed derivatives. A peculiarity of the system
of equations written in flux variables for equations with mixed derivatives is
that there do exist coupled terms with time derivatives
Use of Geographic Information Systems for Creation of Electronic Database of Anthrax Burial sites in the Stavropol Territory
Objective of the study was to use geographic information systems to create an electronic database of anthrax burials and electronic cadastres in the Stavropol Territory. Materials and methods. ESRI - ArcGIS10 software was used as a GIS platform. Results and discussion. A retrospective analysis of the epizootiologic and epidemiological situation on anthrax in the Stavropol Territory was carried out. It was revealed that 352 anthrax stationary potentially hazardous sites were located in the territory of all 26 districts, in 16 of which 52 were abandoned anthrax burials. The greatest epidemiological risk is posed by 22 cattle burial grounds, in which animal corpses were buried (42.3 %). 30 cattle burial grounds with ash burials (57.7 %) pose a lower potential danger. The arrangement of anthrax burial sites in the Stavropol Territory has a number of disadvantages, only 23 cattle burial grounds (44.2 %) have a satisfactory veterinary and sanitary state. Based on the information obtained, an electronic geographic information database of anthrax cattle burial grounds was created for each district of the Stavropol Territory. The structure of the database is presented in the form of a table, which contains all the basic information about the burial, including geographical coordinates. The information was then entered into the ArcGIS10 program, using the geographical method. Each point, plotted on the map, contains the description of the animal burial ground, presented in the table. Thus, the main layer of the geographic information system is created. It can be overlaid with other layers that carry information about the location of the anthrax stationary potentially hazardous sites, the nature of the soil, objects located in the territory. In addition, electronic cadastral atlases of the location of anthrax cattle burials in each district of the Stavropol territory have been created. Electronic cadastral atlases are easier to use, do not require specialized personnel and applicable computer GIS system, but at the same time can give the necessary information about a particular burial in the Stavropol Territory
Effectiveness of Disinsection and Deratization in Gorno-Altai High-Mountain Natural Plague Focus
Epidemic complications in the territory of Gorno-Altai high-mountain natural plague focus, associated with increase in numbers of carriers and vectors of the dangerous diseases, entailed strengthening of preventive element in the system of epidemiological surveillance. Objective of the study was to assess the efficiency of disinsection and deratization during anti-epidemic campaign. Materials and methods. Investigations were performed in 2014-2017 in the territory of Kosh-Agach district of the Republic of Altai, based on the archival and operational records from Altai Plague Control Station, Rospotrebnadzor Administration in the Republic of Altai, and our own data. “Interactive Map on Management of Health Promotion Measures in Gorno-Altai high-mountain natural plague focus” was used as an assessment tool. Results and conclusions. The most hard-hitting sections of preventive complex as regards plague are still disinsection and deratization. Application of advanced methods and means of control over numbers of carriers and vectors of the infection testify to their high anti-epidemic effectiveness. Insecticide and rodenticide treatments of encampments situated in epizootic areas, disinsection and deratization in major population centers in the territory of the focus allowed for the reduction in risk of population infection. Technical efficiency of the field disinsection amounted to 96.7 %, community deratization and disinsection varied from 91.6 to 100 %. Emergency insecticide and rodent treatments in epizootic areas alongside other measures provided for epidemiological welfare on plague
Инфекции нижних дыхательных путей респираторно-синцитиальной вирусной этиологии у недоношенных детей и детей с бронхолегочной дисплазией
The article is devoted to the study of features of lower respiratory tract infection associated with respiratory syncytial virus. 40 cases of RSV-bronchiolitis in preterm children under year with/without bronchopulmonary dysplasia were analyzed. It was established that disease in those groups of patients had severe course because of the respiratory failure, which dominates in clinical pictures as symptoms of bronchial obstruction and apnea. Treatment of severe RSV-infection often demand admission to intensive care unit, supplemental oxygen and/or mechanical ventilation.Статья посвящена изучению особенностей поражения нижних дыхательных путей при респираторно-синцитиальной вирусной (РСВ) инфекции. Проанализировано 40 случаев РСВ-бронхиолита у недоношенных детей первого года жизни с бронхолегочной дисплазией и без нее. Установлено, что заболевание у данного контингента пациентов имеет тяжелое течение за счет развития дыхательной недостаточности, которая является основным клиническим проявлением, наряду с симптомами бронхиальной обструкции и апноэ. Лечение тяжелой РСВ-инфекции зачастую проводится в условиях отделения реанимации и интенсивной терапии, необходимо проведение оксигенотерапии и искусственной вентиляции легких
Comparative evaluation of methods used for determining the cryogenic phase transformations of moisture in construction materials
Value of the natriuretic peptide level in diagnostics of newborns with heart failure
The article contains the first-ever data on correlation of the level of N-terminal fragment of natriuretic peptide in the serum of fullterm newborns with circulatory failure and persistent pulmonary hypertension syndrome; while the N-terminal fragment of natriuretic peptide can serve as a marker of circulatory failure in newborns. The study demonstrates that the dynamics of this peptide allows us to evaluate the effectiveness of the therapy
Solution of sectorization problems for an air traffic control area. I. Basic principles and questions of airspace sectorization and its formalization as an optimization problem
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