The article presents an analysis of the development of the Lviv tram network from the end of the XIXth century till nowadays and for the near future. The stages of construction of tram depots and ...development of tram lines in the context of the city territory servicing, their changes, and connection with the configuration of the city street network are shown. City planning approaches to further development of the tram network infrastructure are presented.
In the present review, we summarised the information on helminths of 14 species of wild carnivorans (a total of 260 individuals examined) from Ukraine based on an investigation of collection ...materials. Additionally, helminths of the domestic dog, Canis familiaris L. (n = 73) and domestic cat, Felis catus L. (n = 11) were reviewed. Helminth species and main helminth taxa (Cestoda, Trematoda, and Nematoda) were classified according to their occurrence (prevalence of infection). Helminth fauna composition and structure in host families Canidae, Felidae, and Mustelidae and in separate host species were analysed. Sixty helminth species were found in wild carnivorans in Ukraine, including 18 species of cestodes, 11 species of trematodes, and 31 species of nematodes. In wild Canidae, 45 helminth species were recorded. Nematodes were a predominating group of helminths in the red fox, Vulpes vulpes L., cestodes predominated in the wolf, Canis lupus L., and trematodes occurred more often in the raccoon dog, Nyctereutes procyonoides Gray. Mustelidae (40 specimens of 8 species) harboured 25 helminth species; nematodes predominated by their occurrence and number of species. In the American mink, Neovizon vison Brisson, however, trematodes appeared to be the predominating group of helminths. The wolf, the red fox, and the domestic dog showed maximum similarity in the helminth fauna composition. A rather high similarity was observed between the helminth faunae of the raccoon dog and the American mink (IS = 0.42), both hosts being introduced species in the fauna of Ukraine.
General description of the research topic. A technique and an algorithm for calculating the thermal field of electromagnets operating in complex forced systems proposed by authors are considered. The ...widespread use of such devices in electromechanical switching devices allows not only to increase their speed but also significantly reduce the size, mass and energy losses, which indicates the relevance of this topic. The mathematical model of heating the windings of forced electromagnets proposed by the authors is a system of 1D differential equations of stationary heat transfer in a cylindrical coordinate system, supplemented by equations of electrical and magnetic circuits. This model allows to take into account the ripple of the currents in the windings and the losses in the magnetic core due to these ripples, contains certain signs of scientific novelty and represents the goal of the paper. The algorithm developed by the authors for calculating the thermal field of electromagnets operating in forced control systems is a complex iterative cycle. Its implementation is greatly simplified by using the Maple computing environment which allows to realize complicated and cumbersome mathematical transformations, automates the process of computations, and obtain results of numerical simulation in a convenient tabular and/or graphic form, which indicates the practical significance of this works. The results of comparison of computation results with experimental data presented in the paper indicate the adequacy of the model and algorithm proposed. References 17, tables 1, figures 7. Key words: electromagnets, thermal field, forced control, switching devices, Maple computing environment, computer simulation.
General description of the research topic. The authors propose a technique for calculating the dynamics of electromagnets operating in complex forced systems. Such forced electromagnets are widely ...used in electromechanical switching devices, in particular in vacuum contactors, to reduce their size, energy consumption and to increase speed, which indicates the relevance of this topic. A mathematical model of the dynamics of a forced electromagnetic system, which takes into account the peculiarities of behavior in transients of its individual elements--the mechanical system, the magnetic and electrical circuits, taking into account the interaction of the electromagnet with a control device when the apparatus is activated, contains certain signs of scientific novelty and is the purpose of the paper. The technique of calculating the dynamics of forced electromagnets uses the computing environment Maple. The calculation is based on a mathematical model, which is a system of nonlinear differential equations of the magnetic and electric circuits, supplemented by the equations of motion of the elements of a mechanical system. The use of the computing environment Maple, applied here to automatically perform the mathematical transformations, allows avoiding the complicated processes of choosing the numerical integration method, programming of complex and cumbersome equations and numerical integration procedures, to obtain results of calculations in convenient tabular and/or graphic form. This specifically indicates the practical significance of this work. The results of the comparison of calculations with previously published experimental data presented in the paper indicate the high efficiency of the proposed models and techniques. References 10, figures 6. Key words: electromagnets, dynamics, forced control, switching devices, vacuum contactors, computing environment Maple.
Exposure to ionizing radiation has long been suspected to increase mutation load in humans. Nevertheless, such events as atomic bombing seem not to have yielded significant genetic defects. The ...Chernobyl accident created a different, long-term exposure to radiation. Clean-up teams (or 'liquidators') of the Chernobyl reactor are among those who received the highest doses, presumably in some combination of acute and chronic forms. In this study, children born to liquidator families (currently either in the Ukraine or Israel) conceived after (CA) parental exposure to radiation were screened for the appearance of new fragments using multi-site DNA fingerprinting. Their sibs conceived before (CB) exposure served as critical internal controls, in addition to external controls (non-exposed families). An unexpectedly high (sevenfold) increase in the number of new bands in CA individuals compared with the level seen in controls was recorded. A strong tendency for the number of new bands to decrease with elapsed time between exposure and offspring conception was established for the Ukrainian families. These results indicate that low doses of radiation can induce multiple changes in human germline DNA.
When administered either systemically or centrally, glucose is a potent enhancer of memory processes. Measures of glucose levels in extracellular fluid in the rat hippocampus during memory tests ...reveal that these levels are dynamic, decreasing in response to memory tasks and loads; exogenous glucose blocks these decreases and enhances memory. The present experiments test the hypothesis that glucose enhancement of memory is mediated by glycogen storage and then metabolism to lactate in astrocytes, which provide lactate to neurons as an energy substrate. Sensitive bioprobes were used to measure brain glucose and lactate levels in 1-sec samples. Extracellular glucose decreased and lactate increased while rats performed a spatial working memory task. Intrahippocampal infusions of lactate enhanced memory in this task. In addition, pharmacological inhibition of astrocytic glycogenolysis impaired memory and this impairment was reversed by administration of lactate or glucose, both of which can provide lactate to neurons in the absence of glycogenolysis. Pharmacological block of the monocarboxylate transporter responsible for lactate uptake into neurons also impaired memory and this impairment was not reversed by either glucose or lactate. These findings support the view that astrocytes regulate memory formation by controlling the provision of lactate to support neuronal functions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The article discussesthe possibility of using geoinformation technologies as instruments of landscape and ecological planning in the organization ofthe territoriesof various functional purposes, ...including recreational areas. The development of landscape planning in Russiacontributed to the formationof modern ideason the environmentalaspects ofland use planning, the need for geographicalapproach toenvironmental planning andidentifi-cation ofspecificecological frameworkof different typesof landscapesfor sustainabledevelopment of territories. Specialfeaturesof landscape planningprovidesa methodologyfor the designof tourist andrecreational areasand areaswherethe algorithmis based on thecartographic support and using GIS of all phases ofthe organization, operation and monitoringof the recreationalnature.
Aims. We explore the prospects for the detection of giant circumbinary exoplanets and brown dwarfs (BDs) orbiting Galactic double white dwarfs (DWDs) binaries with the Laser Interferometer Space ...Antenna (LISA). Methods. By assuming an occurrence rate of 50%, motivated by white dwarf pollution observations, we built a Galactic synthetic population of P-type giant exoplanets and BDs orbiting DWDs. We carried this out by injecting different sub-stellar populations, with various mass and orbital separation characteristics, into the DWD population used in the LISA mission proposal. We then performed a Fisher matrix analysis to measure how many of these three-body systems show a periodic Doppler-shifted gravitational wave perturbation detectable by LISA. Results. We report the number of circumbinary planets (CBPs) and BDs that can be detected by LISA for various combinations of mass and semi-major axis distributions. We identify pessimistic and optimistic scenarios corresponding, respectively, to 3 and 83 (14 and 2218) detections of CBPs (BDs), observed during the length of the nominal LISA mission. These detections are distributed all over the Galaxy following the underlying DWD distribution, and they are biased towards DWDs with higher LISA signal-to-noise ratio and shorter orbital period. Finally, we show that if LISA were to be extended for four more years, the number of systems detected will be more than doubled in both the optimistic and pessimistic scenarios. Conclusions. Our results present promising prospects for the detection of post-main sequence exoplanets and BDs, showing that gravitational waves can prove the existence of these populations over the totality of the Milky Way. Detections by LISA will deepen our knowledge on the life of exoplanets subsequent to the most extreme evolution phases of their hosts, clarifying whether new phases of planetary formation take place later in the life of the stars. Such a method is strongly complementary to electromagnetic studies within the solar region and opens a window into the investigation of planets and BDs everywhere in the entire Galaxy, and possibly even in nearby galaxies in the Local Group.
Context.
Milky Way dwarf satellites are unique objects that encode the early structure formation and therefore represent a window into the high redshift Universe. So far, their study has been ...conducted using electromagnetic waves only. The future Laser Interferometer Space Antenna (LISA) has the potential to reveal Milky Way satellites through gravitational waves emitted by double white dwarf (DWD) binaries.
Aims.
We investigate gravitational wave signals that will be detectable by LISA as a possible tool for the identification and characterisation of the Milky Way satellites.
Methods.
We used the binary population synthesis technique to model the population of DWDs in dwarf satellites and we assessed the impact on the number of LISA detections when making changes to the total stellar mass, distance, star formation history, and metallicity of satellites. We calibrated predictions for the known Milky Way satellites on their observed properties.
Results.
We find that DWDs emitting at frequencies ≳3 mHz can be detected in Milky Way satellites at large galactocentric distances. The number of these high frequency DWDs per satellite primarily depends on its mass, distance, age, and star formation history, and only mildly depends on the other assumptions regarding their evolution such as metallicity. We find that dwarf galaxies with
M
⋆
> 10
6
M
⊙
can host detectable LISA sources; the number of detections scales linearly with the satellite’s mass. We forecast that out of the known satellites, Sagittarius, Fornax, Sculptor, and the Magellanic Clouds can be detected with LISA.
Conclusions.
As an all-sky survey that does not suffer from contamination and dust extinction, LISA will provide observations of the Milky Way and dwarf satellites galaxies, which will be valuable for Galactic archaeology and near-field cosmology.
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