A method for track reconstruction in the BM@N experiment, based on a constrained combinatorial search for track candidates, i.e. combinations of detector hits possibly belonging to a track, is ...presented. The algorithm has been implemented as a Vector Finder software toolkit containing track reconstruction procedures and tools to define hit acceptance windows (a priori constraints) for the track search. Track reconstruction results for simulated events of heavy-ion interactions are shown demonstrating the performance of the approach proposed.
Context.
Kinematic misalignment between gas and stellar components is observed in a certain fraction of galaxies. It believed to be caused by the acquisition of gas from the external reservoir by, ...for example, major or minor mergers, accretion from cosmological filaments, or the circumgalactic medium.
Aims.
We aim to constrain the possible sources of the gas that forms the counter-rotating component.
Methods.
We derived the gas-phase oxygen abundances of 69 galaxies with a kinematic misalignment between gas and stellar components from the MaNGA DR17 survey and compared them with the metallicity expected according to the mass–metallicity relation.
Results.
We find that the oxygen abundance of the counter-rotating gas in our sample is higher than 8.2 dex, which rules out a significant role for the inflow of pristine gas. Meanwhile, there is a significant difference in the oxygen abundance of the counter-rotating gas between red and blue galaxies. In general, the oxygen abundance is lower than expected for the stellar mass in red galaxies but is compatible with or even higher than typical values for the stellar mass in blue galaxies.
Conclusions.
We show that the exchange of enriched gas between galaxies is the most plausible mechanism for explaining the metallicity of counter-rotating gas components in galaxies of all masses and colors. Meanwhile, minor mergers may play a significant role in the formation of counter-rotating gas components in red and quenched galaxies.
DJ-1 protein has multiple specific mechanisms to protect dopaminergic neurons against neurodegeneration in Parkinson's disease. Wild type DJ-1 can acts as oxidative stress sensor and as an ...antioxidant. DJ-1 exhibits the properties of molecular chaperone, protease, glyoxalase, transcriptional regulator that protects mitochondria from oxidative stress. DJ-1 increases the expression of two mitochondrial uncoupling proteins (UCP 4 and UCP5), that decrease mitochondrial membrane potential and leads to the suppression of ROS production, optimizes of a number of mitochondrial functions, and is regarded as protection for the neuronal cell survival. We discuss also the stabilizing interaction of DJ-1 with the mitochondrial Bcl-xL protein, which regulates the activity of (Inositol trisphosphate receptor) IP
3
R, prevents the cytochrome c release from mitochondria and inhibits the apoptosis activation. Upon oxidative stress DJ-1 is able to regulate various transcription factors including nuclear factor Nrf2, PI3K/PKB, and p53 signal pathways. Stress-activated transcription factor Nrf2 regulates the pathways to protect cells against oxidative stress and metabolic pathways initiating the NADPH and ATP production. DJ-1 induces the Nrf2 dissociation from its inhibitor Keap1 (Kelch-like ECH-associated protein 1), promoting Nrf2 nuclear translocation and binding to antioxidant response elements. DJ-1 is shown to be a co-activator of the transcription factor NF-kB. Under nitrosative stress, DJ-1 may regulate PI3K/PKB signaling through PTEN transnitrosylation, which leads to inhibition of phosphatase activity. DJ-1 has a complex modulating effect on the p53 pathway: one side DJ-1 directly binds to p53 to restore its transcriptional activity and on the other hand DJ-1 can stimulate deacylation and suppress p53 transcriptional activity. The ability of the DJ-1 to induce activation of different transcriptional factors and change redox balance protect neurons against aggregation of α-synuclein and oligomer-induced neurodegeneration.
Heavy-ion collisions at NICA energies provide a unique opportunity for the study of the production of hypernuclei in dense baryonic matter. In this paper, the details of the reconstruction procedure ...for hypertritons with the MPD detector in Bi + Bi collisions at NICA energies are presented.
We investigate the star formation processes operating in a mid-infrared bubble N49 site that harbors an O-type star in its interior, an ultracompact H ii region, and a 6.7 GHz methanol maser at its ...edges. The 13CO line data reveal two velocity components (at velocity peaks ∼88 and ∼95 km s−1) in the direction of the bubble. An elongated filamentary feature (length >15 pc) is investigated in each molecular cloud component, and the bubble is found at the interface of these two filamentary molecular clouds. The Herschel temperature map traces all these structures in a temperature range of ∼16-24 K. In the velocity space of 13CO, the two molecular clouds are separated by ∼7 km s−1, and are interconnected by a lower-intensity intermediate velocity emission (i.e., a broad bridge feature). A possible complementary molecular pair at 87, 88 km s−1 and 95, 96 km s−1 is also observed in the velocity channel maps. These observational signatures are in agreement with the outcomes of simulations of the cloud-cloud collision process. There are also noticeable embedded protostars and Herschel clumps distributed toward the filamentary features including the intersection zone of the two molecular clouds. In the bubble site, different early evolutionary stages of massive star formation are also present. Together, these observational results suggest that in the bubble N49 site, the collision of the filamentary molecular clouds appears to be operated about 0.7 Myr ago, and may have triggered the formation of embedded protostars and massive stars.
The research was carried out to study the enzyme activities in the gray forest soil (GF) with the second humus horizon (SHH) relative to the fertilizer application system within the agricultural ...landscapes across Vladimir oblast. The research study was conducted with two soil differences at the multifactor experiment field station in 2021–2023. The reference systems of fertilizer application intensity (for six-field crop rotation) were investigated. Thus, the levels of the fertilizer application intensity were designed as zero (Z) fertilizer + 40 t/ha manure, intense (I) fertilizers N
100
Р
80
К
160
+ 40 t/ha manure, intense mineral (IM) fertilizers N
350
P
220
K
390
, high-intense mineral (HIM) fertilizers N
480
P
280
K
575
, intense organic and mineral (IOM) fertilizers N
310
P
150
K
310
+ 60 t/ha manure, and high-intense organic and mineral (HIOM) fertilizers N
430
P
160
K
360
+ 80t/ha manure. A steady trend to increasing the catalase and invertase enzyme activities in the GF SHH soils was revealed at the reference systems of fertilizer application. The average catalase activity in the GF soil with the second humus horizon was 23% higher than that in the GF soil at the same soil depth (20–40 cm). The maximum catalase enzyme activity in the experiment was observed at the reference system of intense fertilizer use (I) for the GF SHH soil. Thus, it comprised 2.41 and 1.96 mL O
2
/g in the 0–20- and 20–40-cm layers, respectively. T invertase enzyme activity in the gray forest soil with the second humus horizon at the 20–40-cm soil depth was, on average, higher by 30% than that in the gray forest soil. The highest value for this parameter was recorded in two soil differences in the 0–20-cm layer, which comprised 3.50–3.55 mg glucose/g per 40 h. The average humus content in the GF soil with the second humus horizon made up 3.76%, which was 33% higher than that in the GF soil in the 20–40-cm layer. The maximum parameter value within the experiment (0–40-cm layer) was recorded in the GF SHH soil at the reference system of intense fertilizer use, which comprised 4.86%.
ABSTRACT We present a detailed multiwavelength study of observations from X-ray, near-infrared, and centimeter wavelengths to probe the star formation processes in the S237 region. Multiwavelength ...images trace an almost sphere-like shell morphology of the region, which is filled with the 0.5-2 keV X-ray emission. The region contains two distinct environments-a bell-shaped cavity-like structure containing the peak of 1.4 GHz emission at center, and elongated filamentary features without any radio detection at edges of the sphere-like shell-where Herschel clumps are detected. Using the 1.4 GHz continuum and 12CO line data, the S237 region is found to be excited by a radio spectral type of B0.5V star and is associated with an expanding H ii region. The photoionized gas appears to be responsible for the origin of the bell-shaped structure. The majority of molecular gas is distributed toward a massive Herschel clump (Mclump ∼ 260 ), which contains the filamentary features and has a noticeable velocity gradient. The photometric analysis traces the clusters of young stellar objects (YSOs) mainly toward the bell-shaped structure and the filamentary features. Considering the lower dynamical age of the H ii region (i.e., 0.2-0.8 Myr), these clusters are unlikely to be formed by the expansion of the H ii region. Our results also show the existence of a cluster of YSOs and a massive clump at the intersection of filamentary features, indicating that the collisions of these features may have triggered cluster formation, similar to those found in the Serpens South region.
Spontaneous burst firing is a hallmark attributed to the neuronal network activity. It is known to be accompanied by intracellular calcium Са2+i oscillations within the bursting neurons. Studying ...mechanisms underlying regulation of burst firing is highly relevant, since impairment in neuronal bursting accompanies different neurological disorders. In the present study, the contribution of NMDA and GABA(A) receptors to the shape formation of spontaneous burst -was studied in cultured hippocampal neurons. A combination of inhibitory analysis with simultaneous registration of neuronal bursting by whole-cell patch clamp and calcium imaging was used to assess spontaneous burst firing and Са2+i level.
Using bicuculline and D-AP5 we showed that GABA(A) and NMDA receptors effectively modulate burst plateau phase and Са2+i transient spike which can further affect action potential (AP) amplitudes and firing frequency within a burst. Bicuculline significantly elevated the amplitude and reduced the duration of both burst plateau phase and Са2+i spike resulting in an increase of AP firing frequency and shortening of AP amplitudes within a burst. D-AP5 significantly decreases the amplitude of both plateau phase and Са2+i spike along with a burst duration that correlated with an increase in AP amplitudes and reduced firing frequency within a burst. The effect of bicuculline was occluded by co-addition of D-AP5 revealing modulatory role of GABA(A) receptors to the NMDA receptor-mediated formation of the burst.
Our results provide new evidence on importance of NMDA and GABA(A) receptors in shaping burst firing and Ca2+transient spikes in cultured hippocampal neurons.
•GABA(A)R and NMDAR bi-directionally modulate burst plateau phase amplitude.•GABA(A)R and NMDAR bi-directionally modulate burst Ca2+-spike amplitude.•GABA(A)R and NMDAR modulate burst APs amplitude and firing frequency.•NMDAR plays leading role in tuning parameters of the burst.•GABA(A)R modulates NMDAR-mediated tuning of the burst.
We determine the radial abundance distributions across the discs of 14 irregular galaxies of the types Sm and Im (morphological T types 9 and 10) as traced by their H ii regions. The oxygen and ...nitrogen abundances in H ii regions are estimated through the T
e method or/and with the counterpart method (C method). Moreover, we examine the correspondence between the radial abundance gradient and the surface brightness profile. We find that irregular galaxies with a flat inner profile (flat or outwardly increasing surface brightness in the central region) show shallow (if any) radial abundance gradients. On the other hand, irregular galaxies with a steep inner profile (with or without a bulge or central star cluster) usually show rather steep radial abundance gradients. This is in contrast to the widely held belief that irregular galaxies do not usually show a radial abundance gradient.
Oxygen abundance maps of CALIFA galaxies Zinchenko, I. A; Pilyugin, L. S; Grebel, E. K ...
Monthly Notices of the Royal Astronomical Society,
11/2016, Letnik:
462, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We construct maps of the oxygen abundance distribution across the discs of 88 galaxies using Calar Alto Legacy Integral Field Area survey (CALIFA) Data Release 2 (DR2) spectra. The position of the ...centre of a galaxy (coordinates on the plate) was also taken from the CALIFA DR2. The galaxy inclination, the position angle of the major axis, and the optical radius were determined from the analysis of the surface brightnesses in the Sloan Digital Sky Survey (SDSS) g and r bands of the photometric maps of SDSS Data Release 9. We explore the global azimuthal abundance asymmetry in the discs of the CALIFA galaxies and the presence of a break in the radial oxygen abundance distribution. We found that there is no significant global azimuthal asymmetry for our sample of galaxies, i.e. the asymmetry is small, usually lower than 0.05 dex. The scatter in oxygen abundances around the abundance gradient has a comparable value, ≲0.05 dex. A significant (possibly dominant) fraction of the asymmetry can be attributed to the uncertainties in the geometrical parameters of these galaxies. There is evidence for a flattening of the radial abundance gradient in the central part of 18 galaxies. We also estimated the geometric parameters (coordinates of the centre, the galaxy inclination and the position angle of the major axis) of our galaxies from the analysis of the abundance map. The photometry-map-based and the abundance-map-based geometrical parameters are relatively close to each other for the majority of the galaxies but the discrepancy is large for a few galaxies with a flat radial abundance gradient.
PDF
