Current experimental evidence shows that interictal discharges consist of a short spike and a slow wave, which is regarded as long-lasting hyperpolarization. Feedback inhibitory connections were ...studied by modeling the synchronization of interictal discharges. Studies in rats in a state of light narcotic sleep with application of GABA
A
receptor blockers to the cortex showed that interictal discharges arose in neighboring areas of the cortex, first independently of each other and then synchronized. The durations of slow waves (inhibitory phase) were identical in experiments in which interictal discharges arose simultaneously. Recording in these and other experiments showed increases in the time delay between the moments at which interictal discharges were generated. The durations of the slow waves (inhibitory phase) of interictal discharges increased in conditions of increased synchronization. Interictal discharges occurring initially had longer durations of inhibition than those at a neighboring point, as inhibition from neighboring networks via feedback inhibitory connections is added to the intrinsic inhibition in the neural network. When excitation occurred, it was followed by onset of feedback inhibition, which restricted the duration of excitation, thus creating a time window for integration; this also occurred in neighboring neural networks in the cortex.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Here we present detailed analysis of the distinct X-ray emission features present within the eastern radio lobe of the Pictor A galaxy, around the jet termination region, utilizing the data ...obtained from the Chandra X-ray Observatory. Various emission features have been selected for the study based on their enhanced X-ray surface brightness, including five sources that appear pointlike, as well as three extended regions, one characterized by a filamentary morphology. For those, we perform a basic spectral analysis within the 0.5–7 keV range. We also investigate various correlations between the X-ray emission features and the nonthermal radio emission, utilizing the high-resolution radio maps from the Very Large Array at gigahertz frequencies. The main novel findings following from our analysis concern the newly recognized bright X-ray filament located upstream of the jet termination region, extending for at least 30 kpc (projected), and inclined with respect to the jet axis. For this feature, we observe a clear anticorrelation between the X-ray surface brightness and the polarized radio intensity, as well as a decrease in the radio rotation measure with respect to the surroundings. We speculate on the nature of the filament, in particular addressing a possibility that it is related to the presence of a hot X-ray-emitting thermal gas, only partly mixed with the nonthermal radio/X-ray-emitting electrons within the lobe, combined with the reversals in the lobe’s net magnetic field.
Thermal emission spectra of the Al
2
O
3
/Er
3
Al
5
O
12
eutectic (EAG) used in thermophotovoltaics were interpreted by deconvolution into emission spectra of Al
2
O
3
and Er
2
O
3
. The fraction of ...selective emission of Er
3+
ions at EAG temperature 1500 K was ~0.2 and was maximal in the Er
2
O
3
coating.
We study the statements and solvability of the modal control problem (the pole assignment problem) for linear time-invariant hybrid difference-differential systems in symmetric form and for the ...associated delay systems of neutral type. We obtain constructive necessary and sufficient parametric conditions for the modal controllability of the systems in question in various scales of difference-differential controllers. Methods for the construction of such controllers solving the corresponding modal controllability problem are indicated. The results are illustrated by examples and counterexamples.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The valence behavior of neptunium in the reaction of Np(V) with U(IV) in HNO
3
solutions containing hydrazine and Tc(VII) ions has been studied. It was found that Np(V) is reduced to Np(IV) in two ...successive stages differing in the rates, after which the formed Np(IV) is oxidized to the pentavalent state. Simultaneously with the Np(V) reduction, complete oxidation of U(IV) occurs. Kinetic equations describing the rates of Np(V) reduction and U(IV) oxidation are established, and possible schemes of these reactions are studied.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
The radio source 1146+596 is hosted by the elliptical/S0 galaxy NGC 3894, with a low-luminosity active nucleus. The radio structure is compact, suggesting a very young age for the jets in ...the system. Recently, the source has been confirmed as a high-energy (HE; >0.1 GeV)
γ
-ray emitter in the most recent accumulation of Fermi Large Area Telescope data. Here we report on the analysis of the archival Chandra X-ray Observatory data for the central part of the galaxy, consisting of a single 40 ks long exposure. We have found that the core spectrum is best fitted by a combination of an ionized thermal plasma with a temperature of ≃0.8 keV, and a moderately absorbed power-law component (photon index Γ = 1.4 ± 0.4, hydrogen column density
N
H
/10
22
cm
−2
= 2.4 ± 0.7). We have also detected the iron K
α
line at 6.5 ± 0.1 keV, with a large equivalent width of
1.0
−
0.5
+
0.9
keV. Based on the simulations of Chandra's point-spread function, we have concluded that while the soft thermal component is extended on the scale of the galaxy host, the hard X-ray emission within the narrow photon energy range 6.0–7.0 keV originates within the unresolved core (effectively the central kiloparsec radius). The line is therefore indicative of the X-ray reflection from a cold neutral gas in the central regions of NGC 3894. We discuss the implications of our findings in the context of the X-ray Baldwin effect. NGC 3894 is the first young radio galaxy detected in HE
γ
-rays with the iron K
α
line.
Recent studies have significantly expanded our understanding of the functions of GABAergic interneurons in cortical neural networks. Interneurons of specific classes are involved in generating ...interictal activity in the cortex not only in certain types of pathology, but also in conditions in which inhibition is mediated mainly via GABA
B
receptors. Interictal activity consists of high-amplitude spikes, where a short excitatory phase is followed by a long inhibitory phase occurring almost simultaneously in different parts of the cortex. Highamplitude spikes reflect the synchronous action of excitatory neurons in a local area, while synchronous activity in remote areas is determined by feedback between pyramidal cells and interneurons, when the activity of a large mass of neurons occurs simultaneously within a narrow time interval. Synchronization of interictal spikes involves Martinotti cells, as well as parvalbumin, neurogliaform, and vasoactive intestinal peptide-expressing interneurons, which, as experimental data show, also inhibit via GABA
B
receptors. Several mechanisms are now known which synchronize neuron activity in cortical neural networks: via electrical connections, volume conduction, and synaptic feedback – both between pyramidal neurons and interneurons and between interneurons. We propose that the mechanism of synchronization of interictal spikes in cortical neural networks operates as follows. This mechanism appears to operate in the same way both in local neural networks and over distances. When excitation occurs, it is followed by inhibition mediated by feedback; this limits the excitation period and thus creates a time window for integration, and this also occurs in neighboring cortical neural networks. At the initial stage, the amplitudes of interictal spikes are small and nonsimultaneous in different parts of the cortex. As time progresses, ever more pyramidal neurons become active during the time window, thus increasing the amplitude of the interictal spike, in turn increasing inhibition. Increased inhibition due to feedback ultimately begins to affect neighboring neural networks, with the result that interictal spikes appear almost simultaneously in different parts of the cortex. This produces a significant lengthening of postspike inhibition, as inhibition within a neural network is supplemented by inhibition from neighbors via inhibitory feedback.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The aim of the work is forecasting the development of nuclear power in Russia and the world for the period up to 2050 under various scenarios of constraints on carbon dioxide emissions. A brief ...comparative analysis of the main characteristics of the forecasts of the International Energy Agency (IEA) and the International Renewable Energy Agency (IRENA) has been carried out. Additionally, calculations were performed using the mathematical models of the world energy system GEM and GEM-Dyn developed at the ISEM SB RAS. The optimal ratio of nuclear and non-nuclear energy sources has been determined. It is shown that nuclear power, including nuclear power plants operating on a closed fuel cycle, along with renewable energy sources, is an effective technology that can solve the problem of reducing carbon dioxide emissions. Calculations have shown that in the sustainable development scenario, the capacity of nuclear power plants in Russia in the period from 2020 to 2050 can increase by 2.7 times, and their share in electricity generation can reach 21–25% in 2030 and 26–35% in 2050. The average annual growth rate (for 30 years) of the installed capacity of nuclear power plants in Russia in the sustainable development scenario is 3.1% compared to 2.7% for the world as a whole. In the GEM and GEM-Dyn calculations performed by the authors, the scale of nuclear energy use turned out to be about 30% higher than in the scenarios of the International Energy Agency due to more conservative estimates of the opportunities for improving the performance of renewable energy sources and taking into account the need to back-up their capacity.
We develop statistical methods for the comparative analysis of the accuracy of relations used for the determination of the residual strength of plastic pipes with rectangular surface defects. In the ...existing approaches, the accuracy of relations is established for the entire set of experiments as a single generalized value. At the same time, in the present work, the corresponding values are established separately for every fixed collection of the sizes of defects (points of interest). For each test, we determine its weight, which is not larger than one at every point of interest. The statistical analysis of accuracy is performed separately for each point of interest, which enables us to smooth out the experimental errors and determine the error of the formula itself more precisely.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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