Frequency shifts in gravitational resonance spectroscopy

Quantum states of ultracold neutrons in the gravitational field are to be characterized through gravitational resonance spectroscopy. This paper discusses systematic effects that appear in the spectroscopic measurements. The discussed frequency shifts, which we call Stern-Gerlach shift, interference shift, and spectator state shift, appear in conceivable measurement schemes and have general importance. These shifts have to be taken into account in precision experiments

A spectroscopy approach to measure the gravitational mass of antihydrogen

We study a method to induce resonant transitions between antihydrogen ($\bar{H}$) quantum states above a material surface in the gravitational field of the Earth. The method consists of applying a gradient of magnetic field, which is temporally oscillating with the frequency equal to a frequency of transition between gravitational states of antihydrogen. A corresponding resonant change in the spatial density of antihydrogen atoms could be measured as a function of the frequency of applied field. We estimate an accuracy of measuring antihydrogen gravitational states spacing and show how a value of the gravitational mass of the $\bar{H}$ atom could be deduced from such a measurement. We also demonstrate that a method of induced transitions could be combined with a free-fall-time measurement in order to further improve the precision

The origin of quasi-periodicities during circular ribbon flares

Solar flares with a fan-spine magnetic topology can form circular ribbons. The previous study based on H\alpha line observations of the solar flares during March 05, 2014 by Xu et al. (2017) revealed uniform and continuous rotation of the magnetic fan-spine. Preliminary analysis of the flare time profiles revealed quasi-periodic pulsations (QPPs) with similar properties in hard X-rays, H\alpha, and microwaves. In this work, we address which process the observed periodicities are related to: periodic acceleration of electrons or plasma heating? QPPs are analysed in the H\alpha emission from the centre of the fan (inner ribbon R1), a circular ribbon (R2), a remote source (R3), and an elongated ribbon (R4) located between R2 and R3. The methods of correlation, Fourier, wavelet, and empirical mode decomposition are used. QPPs in H\alpha emission are compared with those in microwave and X-ray emission. We found multi-wavelength QPPs with periods around 150 s, 125 s, and 190 s. The 150-s period is seen to co-exist in H\alpha, hard X-rays, and microwave emissions, that allowed us to connect it with flare kernels R1 and R2. These kernels spatially coincide with the site of the primary flare energy release. The 125-s period is found in the H\alpha emission of the elongated ribbon R4 and the microwave emission at 5.7 GHz during the decay phase. The 190-s period is present in the emission during all flare phases in the H\alpha emission of both the remote source R3 and the elongated ribbon R4, in soft X-rays, and microwaves at 4--8 GHz. We connected the dominant 150-s QPPs with the slipping reconnection mechanism occurring in the fan. We suggested that the period of 125 s in the elongated ribbon can be caused by a kink oscillation of the outer spine connecting the primary reconnection site with the remote footpoint. The period of 190 s is associated with the 3-min sunspot oscillations.Comment: Accepted for publication in A&

Effect of a chemical analogue of autoinducers of microbial anabiosis on the Ca2+ response of mycelial fungi

The microbial alkylhydroxybenzenes (AHB), autoinducers of anabiosis, or d1 factors, participate in stress response of mycelial fungi, as determined from changes in intracellular Ca2+ concentration. By using the genetically modified strain Aspergillus awamori 66A, which produces a recombinant Ca2+-dependent protein aequorin, the dynamics of Ca 2+ was studied in the cytosol of cells exposed to mechanical shock in the presence of the protective doses (0.001-0.01% w/vol) of a chemical AHB analogue, 4-n-hexylresorcinol. Like under stressful conditions, Ca2+ concentration increases in the cell cytosol in response to enhanced AHB level in a growing fungal culture; thus, AHB is perceived by cells as a stress signal. The level of cell response, which was determined from the amplitude of luminescence dependent on the Ca2+ concentration in cytosol was related to the physiological age of the cells and AHB concentration. Micromycete preincubation with AHB was found to protect cells from subsequent stress; this was reflected in the Ca2+ response. The protective AHB effect was manifested as (1) a significant decrease in the amplitude of luminescence and, thus, in Ca2+ accumulation in the cytosol during subsequent mechanical stress (as compared to the control-mechanical stress only); (2) development of the secondary Ca2+ response, which was not observed in the control; (3) a high level of Ca2+ retained in the cytosol for a long time in the presence of AHB (as compared to the control without preincubation with AHB). The mechanisms underlying the AHB effect on the Ca 2+ transport systems are discussed

Effect of a chemical analogue of autoinducers of microbial anabiosis on the Ca2+ response of mycelial fungi

The microbial alkylhydroxybenzenes (AHB), which are anabiosis autoinducers also termed d1 factors, participate in the stress response of mycelial fungi, as determined from changes in intracellular Ca2+ concentration. By using the genetically modified strain Aspergillus awamori 66A, which produces the recombinant Ca2+ -dependent protein aequorin, the dynamics of Ca2+ was studied in the cytosol of cells exposed to mechanical shock in the presence of protective doses (0.001-0.01% w/vol) of a chemical AHB analogue, 4-n-hexylre-sorcinol. As under stressful conditions, Ca2+ concentration increases in the cell cytosol in response to an enhanced AHB level in a growing fungal culture; thus, AHB is perceived by cells as a stress signal. The level of cell response, which was determined from the amplitude of luminescence dependent on the Ca2+ concentration in the cytosol, was related to the physiological age of the cells and the AHB concentration. Micromycete preincubation with AHB was found to protect cells from subsequent stress; this was reflected in the Ca2+ response. The protective AHB effect was manifested as (1) a significant decrease in the amplitude of luminescence and, thus, in Ca2+ accumulation in the cytosol during subsequent mechanical stress (as compared to the control-mechanical stress only); (2) development of a secondary Ca2+ response, which was not observed in the control; and (3) a high level of Ca 2+ retained in the cytosol for a long time in the presence of AHB (as compared to the control without preincubation with AHB). The mechanisms underlying the AHB effect on Ca2+ transport systems are discussed. © 2004 MAIK "Nauka/Interperiodica"

Analysis of the Ca2+ response of mycelial fungi to external effects by the recombinant aequorin method

Using the mutant strain Aspergillus awamori 66A, producing the recombinant Ca2+ -dependent photosensitive protein aequorin, the dynamics of Ca2+ was studied for the first time in the cytosol of micromycetes exposed to stressful factors, such as an increase in extracellular Ca 2+ to 50 mM, hypoosmotic shock, and mechanical shock. The cell response to stress proved to involve an increase in the Ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the time of the amplitude enhancement and relaxation. The level of the Ca2+ response depended on the physiological stimulus. Inhibitory analysis with various agents that block Ca2+ channels and with agonists that specifically enhance the activity of the channels suggested that (1) the level of Ca2+ in the cytosol of micromycetes increases in response to stress because of the ion influx from both the growth medium and intracellular reservoirs and (2) potential-dependent transport systems play the major role in the Ca2+ influx into the cytosol of the micromycete cells. © 2004 MAIK "Nauka/ Interperiodica"

Analysis of the Ca2+ response of mycelial fungi to external effects by the recombinant aequorin method

Using the mutant strain Aspergillus awamori 66A producing a recombinant Ca2+-dependent photosensitive protein aequorin, the dynamics of Ca2+ was studied for the first time in the cytosol of the micromycetes exposed to stressful factors, such as an increase in extracellular Ca2+ to 50 mM, hypoosmotic shock, and mechanical shock. Cell response to stress proved to involve an increase in the Ca2+ concentration in the cytosol, which was determined from the amplitude of aequorin luminescence and the time of the amplitude enhancement and relaxation. The level of Ca 2+ response depended on the physiological stimulus. Inhibitory analysis with various agents that block Ca2+ channels and with agonists that specifically enhance the activity of the channels suggested that (1) the level of Ca2+ in the cytosol of micromycetes increases in response to stress because of the ion influx from both the growth medium and intracellular reservoirs and (2) the potential-dependent transport systems play the major role in the Ca2+ influx into the cytosol of the micromycete cells

The story of the disease of tsarevich Alexey: view from the 21st century

The article presents the reconstruction of a clinical case of the acute hemophilic hemarthrosis of Tsarevich Alexei Nikolaevich Romanov, proposed conducting tactics based on modern clinical guidelines for the diagnosis and treatment of hemophilia.В статье приведена реконструкция клинического случая острого гемофилического гемартроза у царевича Алексея Николаевича Романова, предложена тактика ведения на основании современных клинических рекомендаций по диагностике и лечению гемофилии

THE FIRST RUSSIAN EXPERIENCE OF ABO-INCOMPATIBLE KIDNEY TRANSPLANTATION WITH ANTIGEN-SPECIFIC IMMUNOADSORPTION

We report the first Russian experience of successful ABO-incompatible kidney transplantation using anti-CD20 + IA + IvIg pretransplant conditioning protocol and tacrolimus + MMF + steroids as maintenance immunosuppression. IA procedures were performed on reusable columns ABO-Adsopak® (POCARD Ltd. Moscow, Russia). IA treatments following the administration of rituximab efficiently lowered the immunoglobulin M (IgM) and G (IgG) anti-A/B antibodies titers in all patients. The transplantation could be performed in all cases and the kidneys showed primary function. Unfortunately, the biopsy-proven clinical antibody-mediated rejection (AMR) occurred in one case. Episo- de of AMR was successfully reversed. On 6, 4 and 2 months follow-up, serum creatinine levels were 117, 127 and 87 μmol/l, respectively. We consider ABO-incompatible transplantation as a safe and promising procedure in particu- lar cases for those patients having related but ABO-incompatible donors. Given the shortage of donor organs ABO- incompatible living donor kidney transplantation may become a treatment of choice for many patients

Kink oscillations of coronal loops

Kink oscillations of coronal loops, i.e., standing kink waves, is one of the most studied dynamic phenomena in the solar corona. The oscillations are excited by impulsive energy releases, such as low coronal eruptions. Typical periods of the oscillations are from a few to several minutes, and are found to increase linearly with the increase in the major radius of the oscillating loops. It clearly demonstrates that kink oscillations are natural modes of the loops, and can be described as standing fast magnetoacoustic waves with the wavelength determined by the length of the loop. Kink oscillations are observed in two different regimes. In the rapidly decaying regime, the apparent displacement amplitude reaches several minor radii of the loop. The damping time which is about several oscillation periods decreases with the increase in the oscillation amplitude, suggesting a nonlinear nature of the damping. In the decayless regime, the amplitudes are smaller than a minor radius, and the driver is still debated. The review summarises major findings obtained during the last decade, and covers both observational and theoretical results. Observational results include creation and analysis of comprehensive catalogues of the oscillation events, and detection of kink oscillations with imaging and spectral instruments in the EUV and microwave bands. Theoretical results include various approaches to modelling in terms of the magnetohydrodynamic wave theory. Properties of kink oscillations are found to depend on parameters of the oscillating loop, such as the magnetic twist, stratification, steady flows, temperature variations and so on, which make kink oscillations a natural probe of these parameters by the method of magnetohydrodynamic seismology