Modulation of Circumstellar Extinction in a Young Binary System with a Low-Mass Companion in a Noncoplanar Orbit

The cyclic activity model of a young star with the low-mass secondary component (q = M2/M1 <= 0.1) accreting a matter from circumbinary disk is considered. It is assumed that the orbit is circular and the disk and orbital planes are non-coplanar. Sets of hydrodynamics models of such a system have been calculated by the SPH method and then the variations of the circumstellar extinction and phase light curves were determined. The calculations showed that depending on the model parameters and orientation of the system in regards to an observer the different in shape and amplitude light curves can be observed. An important property of the considered models is also the dependence of the mass accretion rate onto the components on the phase of the orbital period. The results of the calculation can be used for analysis of the cyclic activity of UX Ori stars and young stars with the long-lasting eclipses.Comment: 14 pages, 7 figure

The first result of the neutrino magnetic moment measurement in the GEMMA experiment

The first result of the neutrino magnetic moment measurement at the Kalininskaya Nuclear Power Plant (KNPP) with the GEMMA spectrometer is presented. An antineutrino-electron scattering is investigated. A high-purity germanium detector of 1.5 kg placed 13.9 m away from the 3 GW reactor core is used in the spectrometer. The antineutrino flux is $2.73\times 10^{13} \nu_e / cm^2 / s$. The differential method is used to extract the $\nu$-e electromagnetic scattering events. The scattered electron spectra taken in 6200 and 2064 hours for the reactor ON and OFF periods are compared. The upper limit for the neutrino magnetic moment $\mu_\nu < 5.8\times 10^{-11}$ Bohr magnetons at 90{%} CL is derived from the data processing.Comment: 9 pages, 10 figures, 2 table

Tuning Pt characteristics on Pt/C catalyst for aqueous-phase reforming of biomass-derived oxygenates to bio-H-2

Pt/C catalysts with varied Pt sizes and distributions were investigated for aqueous-phase reforming (APR) of ethylene glycol (EG) to H2. APR experiments were performed on a continuous-flow fixed bed reactor with a catalyst loading of 1 g and EG feeding of 120 mL h−1 at 225 °C and 35 bar for 7 h. The fresh and used Pt/C catalysts were characterized by XRF, BET, CO chemisorption, TEM, XTEM, and XPS. Catalyst preparation protocols changed Pt characteristics on Pt/C catalysts, leading to a distinguishable H2 production. The rates for EG conversion and H2 production increased linearly with mean Pt size (3–11 nm), while having a volcano relationship with the mean size of agglomerated Pt particles (17–30 nm). Pt with concentrated Pt particles on surface of Pt/C catalysts was more preferable for APR of EG than the homogeneously distributed in catalysts. Optimal performance was obtained over a Pt/C-PR catalyst, which was prepared by precipitation method, showing a superb turnover frequency of 248 molH2 molPt−1 min−1 for H2 production from EG in APR. Besides, Pt/C catalysts also showed excellent stability. These results have shown the promise of Pt/C catalyst for APR of EG, which can be extended for bio-H2 production via APR of biomass-derived oxygenates in waste streams

On the Complexity of Query Result Diversification

Query result diversification is a bi-criteria optimization problem for ranking query results. Given a database D, a query Q and a positive integer k, it is to find a set of k tuples from Q(D) such that the tuples are as relevant as possible to the query, and at the same time, as diverse as possible to each other. Subsets of Q(D) are ranked by an objective function defined in terms of relevance and diversity. Query result diversification has found a variety of applications in databases, information retrieval and operations research. This paper studies the complexity of result diversification for relational queries. We identify three problems in connection with query result diversification, to determine whether there exists a set of k tuples that is ranked above a bound with respect to relevance and diversity, to assess the rank of a given k-element set, and to count how many k-element sets are ranked above a given bound. We study these problems for a variety of query languages and for three objective functions. We establish the upper and lower bounds of these problems, all matching, for both combined complexity and data complexity. We also investigate several special settings of these problems, identifying tractable cases. 1

Clinical characteristics of patients with COVID-19 depending on the treatment received and the presence of type 2 diabetes mellitus

BACKGROUND. Type 2 diabetes mellitus (T2DM) is an independent risk factor for adverse clinical outcomes in patients with Covid-19. There is currently insufficient data evaluating the efficacy and safety of drugs for the treatment of COVID-19, especially in patients with T2DM.AIM. The aim of study was to identify an associative relationship between the drugs used and the clinical outcomes of patients with Covid-19 and T2DM.MATERIALS AND METHODS. A retrospective analysis of the clinical outcomes of 1753 patients with COVID-19 who were hospitalized to the redesignated departments of multidisciplinary city clinical hospital in the period from 23.03.2020 to 01.06.2020.RESULTS. The total number of patients is 1,753, of which 311 (17.7%) are patients with DM2. 92.6% of patients received treatment for COVID-19. At the same time, 91.4% of patients received antibiotics (a/b), 61.5% — bronchodilators, 56.6% — injectable anticoagulants (a/c), 45.2% — hydroxychloroquine, 6.3% — antiviral drugs, 5.4% — oral a/c, 4.6% — glucocorticosteroids (GCS), 1.9% — Tocilizumab.Decrease of risk of death among patients with COVID-19 was as the therapy of a/b (OR 0.07, 95% CI 0.05–0.11, p&lt;0.05), bronchodilators (OR 0.12, 95% CI 0.08–0.18, p&lt;0.05) and injection a/c (OR 0.47, 95% CI 0.34–0.67, p&lt;0.05). At the same time, among patients with DM2, compared with patients without DM2, there was a more pronounced reduction in the risk of death during injectable a/c therapy: among patients with DM2, the risk of death decreased by 2.6 times (OR 0.39, 95% CI 0.21–0.73, p&lt;0.05), among patients without DM2 — by 2.1 times (OR 0.47, 95% CI 0.31–0.71, p&lt;0.05). Antiviral drugs was associated with an increased chance of death among patients without DM2 (OR 2.64, 95% CI 1.44–4.86, p&lt;0.05) and among patients with DM2 (OR 4.98, 95% CI 2.11–11.75, p&lt;0.05).CONCLUSION. A significant decrease of the risk of death among patients with COVID-19 was as the therapy of a/b, bronchodilators, and injectable a/c. An increase of the risk of death was observed during therapy with antiviral drugs

Possibilities of application a fixed combination of alogliptin and pioglitazone for type 2 diabetes mellitus treatment

Hyperglycemia in T2DM is based on three main mechanisms: insulin resistance, progressive β-cell dysfunction, and excess glucose production by the liver.The onset of T2DM is usually preceded by a long period of insulin resistance. Prescribing sugar drugs that affect different links of pathogenesis, reducing a steady decrease in glycemia. To date, in clinical practice, various combinations of hypoglycemic drugs are used, the choice of which is determined by the characteristics of the course of diabetes in the patient, the presence of concomitant diseases and complications of diabetes, as well as the dominant clinical problem. This resolution provides an expert council opinion on the feasibility of using a combination of alogliptin and pioglitazone in patients with type 2 diabetes

The background in the neutrinoless double beta decay experiment GERDA

The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay of 76Ge. The signature of the signal is a monoenergetic peak at 2039 keV, the Q-value of the decay, Q_bb. To avoid bias in the signal search, the present analysis does not consider all those events, that fall in a 40 keV wide region centered around Q_bb. The main parameters needed for the neutrinoless double beta decay analysis are described. A background model was developed to describe the observed energy spectrum. The model contains several contributions, that are expected on the basis of material screening or that are established by the observation of characteristic structures in the energy spectrum. The model predicts a flat energy spectrum for the blinding window around Q_bb with a background index ranging from 17.6 to 23.8*10^{-3} counts/(keV kg yr). A part of the data not considered before has been used to test if the predictions of the background model are consistent. The observed number of events in this energy region is consistent with the background model. The background at Q-bb is dominated by close sources, mainly due to 42K, 214Bi, 228Th, 60Co and alpha emitting isotopes from the 226Ra decay chain. The individual fractions depend on the assumed locations of the contaminants. It is shown, that after removal of the known gamma peaks, the energy spectrum can be fitted in an energy range of 200 kev around Q_bb with a constant background. This gives a background index consistent with the full model and uncertainties of the same size

Results on ββ\beta\beta decay with emission of two neutrinos or Majorons in 76^{76}Ge from GERDA Phase I

A search for neutrinoless $\beta\beta$ decay processes accompanied with Majoron emission has been performed using data collected during Phase I of the GERmanium Detector Array (GERDA) experiment at the Laboratori Nazionali del Gran Sasso of INFN (Italy). Processes with spectral indices n = 1, 2, 3, 7 were searched for. No signals were found and lower limits of the order of 10$^{23}$ yr on their half-lives were derived, yielding substantially improved results compared to previous experiments with $^{76}$Ge. A new result for the half-life of the neutrino-accompanied $\beta\beta$ decay of $^{76}$Ge with significantly reduced uncertainties is also given, resulting in $T^{2\nu}_{1/2} = (1.926 \pm 0.095)\cdot10^{21}$ yr.Comment: 3 Figure