On the possible critical behaviour of a marginally stable stellar disc

Using hydrodynamic approach, it is shown that the properties of a marginally stable collisionless stellar disc resemble those of a thermodynamic system undergoing a gas--liquid phase transition. The maximum in Toomre's stability diagram, which separates gravitationally stable and unstable states with respect to axisymmetric perturbations, can be treated as a critical point for this transition. Static perturbations of stellar density are explored and the mean perturbation amplitude is considered as the order parameter of the theory. The disc's state is assumed to change as the disc passes through the critical point. Since the disc tends to retain hydrostatic equilibrium, structures can be formed spontaneously, identifiable with a seed spiral structure. A power-law scaling of the order parameter in the vicinity of the critical point has been found. The susceptibility and other Landau--Weiss exponents similar to those in the Van der Waals theory are calculated. The critical behaviour of marginally stable discs at the initial stage of their evolution occurs in numerical simulations where snapshots of stellar positions reveal stellar splinters and crescents diverging from the disc centre. These structures can be a result of the phase transition. In numerical simulations, these structures eventually reduce to decaying worm-type features because of the `heating' most likely resulting from instability of stellar orbits due to resonances. Under favourable conditions the critical behaviour leading to the establishment of order in a stellar disc can result in the generation of a spiral structure.Comment: 16 pages, 1 figur

Isolation, characterisation, and selection of wine yeast strains in Etyek-Buda wine district, Hungary

Initiated by the Association “Wine Route of Etyek Wine District”, the objectives of this study were to isolate and identify autochthonous yeast strains from local wines and to determine their oenologically important properties. The first aim of this work was to characterize the taxonomic and phenotypic diversity of the representative Saccharomyces yeast strains that dominate the spontaneous fermentations in this wine district. The results obtained by molecular ribotyping (ARDRA) revealed a strong dominance of S. cerevisiae, but S. bayanus var. uvarum was also present sporadically. Some of the natural isolates exhibited high volatile acid production or poor fermentation capacity, which imply a quality risk in spontaneous fermentations. Most of the isolates, however, displayed good oenological features during lab scale fermentations. As the second aim of this work, the most promising, selected strains were further tested for oenological properties in microvinification scale and, finally, in large scale fermentations. The analytical and sensory analysis proved that selected strains, including S. bayanus var. uvarum, can be used as local starter cultures, which may contribute to the typicality of the local wines in comparison with commercial starters

Development of 100^{100}Mo-containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

We report recent achievements in the development of scintillating bolometers to search for neutrinoless double-beta decay of $^{100}$Mo. The presented results have been obtained in the framework of the LUMINEU, LUCIFER and EDELWEISS collaborations, and are now part of the R\&D activities towards CUPID (CUORE Update with Particle IDentification), a proposed next-generation double-beta decay experiment based on the CUORE experience. We have developed a technology for the production of large mass ($\sim$1 kg), high optical quality, radiopure zinc and lithium molybdate crystal scintillators (ZnMoO$_4$ and Li$_2$MoO$_4$, respectively) from deeply purified natural and $^{100}$Mo-enriched molybdenum. The procedure is applied for a routine production of enriched crystals. Furthermore, the technology of a single detector module consisting of a large-volume ($\sim 100$~cm$^3$) Zn$^{100}$MoO$_4$ and Li$_2$$^{100}$MoO$_4$ scintillating bolometer has been established, demonstrating performance and radiopurity that are close to satisfy the demands of CUPID. In particular, the FWHM energy resolution of the detectors at 2615 keV --- near the $Q$-value of the double-beta transition of $^{100}$Mo (3034~keV) --- is $\approx$ 4--10~keV. The achieved rejection of $\alpha$-induced dominant background above 2.6~MeV is at the level of more than 99.9\%. The bulk activity of $^{232}$Th ($^{228}$Th) and $^{226}$Ra in the crystals is below 10 $\mu$Bq/kg. Both crystallization and detector technologies favor Li$_2$MoO$_4$, which was selected as a main element for the realization of a CUPID demonstrator (CUPID-0/Mo) with $\sim$7 kg of $^{100}$Mo

Fibroblasts and growth factors in cardiovascular complications of diabetes type 2

The ways of improvement of the myocardial perfusion and its systolic function in patients with CAD with various cellular technologies has been studied for over 10 years. There is evidence that fibroblasts and their growth factors play a key role in promoting pathological proliferative processes in endothelial and smooth muscle cells of vascular walls in hyperglycemia

Nodular mastocytosis: a case study

A case study of nodular mastocytosis is described. Tacrolimus was used to treat skin manifestations of mastocytosis

Leadership and Management in Science and Technology: Competency Model

The article deals with scientific and methodological substantiation and description of the competency model of a modern leader and manager in scientific and technological sphere. This model has been developed by the authors on the initiative of the Coordinating Council for Youth Affairs in Scientific and Educational Spheres of the Presidential Council for Science and Education in the framework of the managers’ contest “Leaders of Russia” (specialization “Science”, season 2019– 2020). The competency model is aimed at improving the efficiency of solving the problems of scientific and technological development of Russia by overcoming the lack of personnel which is ready not only to conduct research at the world level, but also to take responsibility for the formation of priorities for scientific and technological development that meet the interests of Russia, as well as for their implementation. The proposed model is the first of its kind developed and tested system of competencies for improving leadership and management potential of Russian science