We present the complete genome sequence and proteogenomic map for Acholeplasma laidlawii PG-8A (class Mollicutes, order Acholeplasmatales, family Acholeplasmataceae). The genome of A. laidlawii is ...represented by a single 1,496,992-bp circular chromosome with an average G+C content of 31 mol%. This is the longest genome among the Mollicutes with a known nucleotide sequence. It contains genes of polymerase type I, SOS response, and signal transduction systems, as well as RNA regulatory elements, riboswitches, and T boxes. This demonstrates a significant capability for the regulation of gene expression and mutagenic response to stress. Acholeplasma laidlawii and phytoplasmas are the only Mollicutes known to use the universal genetic code, in which UGA is a stop codon. Within the Mollicutes group, only the sterol-nonrequiring Acholeplasma has the capacity to synthesize saturated fatty acids de novo. Proteomic data were used in the primary annotation of the genome, validating expression of many predicted proteins. We also detected posttranslational modifications of A. laidlawii proteins: phosphorylation and acylation. Seventy-four candidate phosphorylated proteins were found: 16 candidates are proteins unique to A. laidlawii, and 11 of them are surface-anchored or integral membrane proteins, which implies the presence of active signaling pathways. Among 20 acylated proteins, 14 contained palmitic chains, and six contained stearic chains. No residue of linoleic or oleic acid was observed. Acylated proteins were components of mainly sugar and inorganic ion transport systems and were surface-anchored proteins with unknown functions.
We investigate the drift paths of energetic particles in Mercury's magnetosphere by tracing their motion through a model magnetic field. Test particle simulations solving the full Lorentz force show ...a quasi‐trapped energetic particle population that gradient and curvature drift around the planet via “Shabansky” orbits, passing though high latitudes in the compressed dayside by equatorial latitudes on the nightside. Due to their large gyroradii, energetic H+ and Na+ ions will typically collide with the planet or the magnetopause and will not be able to complete a full drift orbit. These simulations provide direct comparison for recent spacecraft measurements from MESSENGER. Mercury's offset dipole results in an asymmetric loss cone and therefore an asymmetry in particle precipitation with more particles precipitating in the southern hemisphere. Since the planet lacks an atmosphere, precipitating particles will collide directly with the surface of the planet. The incident charged particles can kick up neutrals from the surface and have implications for the formation of the exosphere and weathering of the surface.
Key Points
Energetic electrons may be trapped on MercuryMercury's offset dipole causes asymmetric particle precipitation
We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive Formula omitted meson muoproduction on the proton at COMPASS using 160 GeV/c polarised Formula omitted and Formula ...omitted beams impinging on a liquid hydrogen target. The measurement covers the range 5.0 GeV/ Formula omitted Formula omitted 17.0 GeV/ Formula omitted, with the average kinematics Formula omitted 2.1 (GeV/c) Formula omitted, Formula omitted GeV/ Formula omitted, and Formula omitted (GeV/c) Formula omitted. Here, Formula omitted denotes the virtuality of the exchanged photon, W the mass of the final hadronic system and Formula omitted the transverse momentum of the Formula omitted meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons ( Formula omitted) indicate a violation of s-channel helicity conservation. Additionally, we observe a sizeable contribution of unnatural-parity-exchange (UPE) transitions that decreases with increasing W. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow to evaluate in a model-dependent way the contribution of UPE transitions and assess the role of parton helicity-flip GPDs in exclusive Formula omitted production.
Wire Tension Test Bench for Wire Chambers Abazov, V. M.; Alexeev, G. D.; Golovanov, G. A. ...
Physics of particles and nuclei letters,
10/2022, Letnik:
19, Številka:
5
Journal Article
Recenzirano
A test bench for determining the wire tension of wire chambers was designed. The tension of the wires is checked by measuring the resonant frequencies of their vibrations. In this work the ...development of the key modules of the test bench and the corresponding software are presented. The results of the test stand performance during the production of detectors for the SPD Muon System Prototype (NICA/JINR) are presented.
Fragilysin (BFT) is metalloprotease that is secreted by enterotoxigenic Bacteroides fragilis. Studying the mechanism of BFT interaction with intestinal epithelial cells requires a pure protein ...sample. In this study, we cloned DNA-fragments coding for the catalytic domain of fragilysin-2 and profragilysin-2 into an E. coli expression vector. Purification methods for the recombinant fragilysin-2 catalytic domain and profragilysin-2 were developed. In addition, we obtained mature active fragilysin-2 from recombinant proprotein by limited tryptic digestion. We tested the biological activity of the recombinant protein samples and revealed that E-cadherin was cleaved when HT-29 cells were treated with mature fragilysin-2 but not with profragilysin-2. Azocoll, azocasein and gelatin were not proteolytically cleaved by mature fragilysin-2. Proteins released in culture medium after HT-29 cells treatment with mature active BFT-2 were identified.
•Recombinant profragilysin-2 and mature active fragilysin-2 (mBFT-2) were obtained.•Limited tryrptic digestion was used for conversion of profragilysin to mature form.•Loss of E-cadherin was detected after the exposure of HT-29 cells to mBFT-2.•Proteins released in culture medium after HT-29 treatment with mBFT were identified.
We have performed the most comprehensive resonance-model fit of π−π−π+ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation ...events from the reaction π−+p→π−π−π++precoil with a 190 GeV/c pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, 0.5<m3π<2.5 GeV/c2, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1<t′<1.0 (GeV/c)2, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with JPC=0−+, 1++, 2++, 2−+, 4++, and spin-exotic 1−+ quantum numbers. The model contains the well-known resonances π(1800), a1(1260), a2(1320), π2(1670), π2(1880), and a4(2040). In addition, it includes the disputed π1(1600), the excited states a1(1640), a2(1700), and π2(2005), as well as the resonancelike a1(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 t′ bins. We extract the relative branching fractions of the ρ(770)π and f2(1270)π decays of a2(1320) and a4(2040), where the former one is measured for the first time. In a novel approach, we extract the t′ dependence of the intensity of the resonances and of their phases. The t′ dependence of the intensities of most resonances differs distinctly from the t′ dependence of the nonresonant components. For the first time, we determine the t′ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances. We have performed extensive systematic studies on the model dependence and correlations of the measured physical parameters.
Abstract
Exercise-induced oxidative stress is a state that primarily occurs in athletes involved in high-intensity sports when pro-oxidants overwhelm the antioxidant defense system to oxidize ...proteins, lipids, and nucleic acids. During exercise, oxidative stress is linked to muscle metabolism and muscle damage, because exercise increases free radical production. The T allele of the Ala16Val (rs4880 C/T) polymorphism in the mitochondrial superoxide dismutase 2 (SOD2) gene has been reported to reduce SOD2 efficiency against oxidative stress. In the present study we tested the hypothesis that the SOD2 TT genotype would be underrepresented in elite athletes involved in high-intensity sports and associated with increased values of muscle and liver damage biomarkers. The study involved 2664 Caucasian (2262 Russian and 402 Polish) athletes. SOD2 genotype and allele frequencies were compared to 917 controls. Muscle and liver damage markers creatine kinase (CK), creatinine, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) were examined in serum from 1444 Russian athletes. The frequency of the SOD2 TT genotype (18.6%) was significantly lower in power/strength athletes (n = 524) compared to controls (25.0%, p = 0.0076) or athletes involved in low-intensity sports (n = 180; 33.9%, p < 0.0001). Furthermore, the SOD2 T allele was significantly associated with increased activity of CK (females: p = 0.0144) and creatinine level (females: p = 0.0276; males: p = 0.0135) in athletes. Our data show that the SOD2 TT genotype might be unfavorable for high-intensity athletic events.
The results of the study of air-cooled coolers with natural and forced heat removal from such powerful semiconductor devices as processors are presented. Experiments were performed in the SOLIDWORKS ...Flow Simulation software environment to assess the influence of the orientation of the formed thermal channels on the efficiency of heat removal from the surface of a heat-loaded element. Three-dimensional models of tower heatsinks with an installed fan and a supporting structure in the form of heat pipes penetrating fins that form horizontal (model No 1) or vertical (model No 2) air channels have been developed, which made it possible to determine the efficiency of heat removal from the processor during natural and forced convection. The developed model No 1 was rotated by 90°, which may be due to design requirements in the development of technical means. This led to a change in the movement of warm air during natural and forced convection along the vertically directed channels with an analysis of the effectiveness of passive and active cooling. The number of heat pipes has been changed from six to two for previously developed types of radiators (models No 1 and 2), only with active cooling. This made it possible to experimentally establish the influence of design solutions (the number and orientation of heat pipes) in the production of modern air-cooled coolers on the efficiency of heat removal.
The results of a study on the removal of thermal energy from processors using air coolers (AC) are presented. Four experiments were carried out, in which, with the help of three-dimensional ...solid-state parametric modeling of various versions of the AC, the most effective ones were identified. In the first experiment, a tower radiator with a supporting structure in the form of copper bars and a vertically mounted fan was developed, which made it possible to determine the efficiency of heat transfer through the radiator. In the next experiment, in the previously developed model, copper bars were replaced with heat pipes and the fan was removed, which made it possible to substantiate the need for the presence or absence of airflow with a gradual increase in processor power during its operation. In the third case, the possibility of changing the fan speed was implemented, which made it possible to set the maximum air flow rate for efficient cooling of the radiator. In the last experiment, the optimal design of the AC was established, which made it possible to effectively implement the dissipation of thermal energy from the processor at various power levels. The necessity of using AC in such modern technical means as personal computers, servers, computer systems, etc., in which there are no restrictions on providing weight and size parameters has been experimentally proved.
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