Connection between orbital modulation of H-alpha and gamma-rays in the Be/X-ray binary LSI+61303

We studied the average orbital modulation of various parameters (gamma-ray flux, H-alpha emission line, optical V band brightness) of the radio- and gamma-ray emitting Be/X-ray binary LSI+61303. Using the Spearman rank correlation test, we found highly significant correlations between the orbital variability of the equivalent width of the blue hump of the H-alpha and Fermi-LAT flux with a Spearman p-value 2e-5, and the equivalent widths ratio EW_B/EW_R and Fermi-LAT flux with p-value 9e-5. We also found a significant anti-correlation between Fermi-LAT flux and V band magnitude with p-value 7.10^{-4}. All these correlations refer to the average orbital variability, and we conclude that the H-alpha and gamma-ray emission processes in LSI+61303 are connected. The possible physical scenario is briefly discussed.Comment: accepted as a Letter in Astronomy and Astrophysic

Thermal QRPA with Skyrme interactions and supernova neutral-current neutrino-nucleus reactions

The Thermal Quasiparticle Random-Phase Approximation is combined with the Skyrme energy density functional method (Skyrme-TQRPA) to study the response of a hot nucleus to an external perturbation. For the sample nuclei, $^{56}$Fe and $^{82}$Ge, the Skyrme-TQRPA is applied to analyze thermal effects on the strength function of charge-neutral Gamow-Teller transitions which dominate neutrino-nucleus reactions at $E_\nu \lesssim 20$~MeV. For the relevant supernova temperatures we calculate the cross sections for inelastic neutrino scattering. We also apply the method to examine the rate of neutrino-antineutrino pair emission by hot nuclei. The cross sections and rates are compared with those obtained earlier from the TQRPA calculations based on the phenomenological Quasiparticle-Phonon Model Hamiltonian. For inelastic neutrino scattering on $^{56}$Fe we also compare the Skyrme-TQRPA results to those obtained earlier from a hybrid approach that combines shell-model and RPA calculations.Comment: Minor revisions according to referee's recomendation

Spectral observations of X Persei: Connection between H-alpha and X-ray emission

We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 1999 - 2018. Using new and published data, we found that during "disc-rise" the expansion velocity of the circumstellar disc is 0.4 - 0.7 km/s. Our results suggest that the disc radius in recent decades show evidence of resonant truncation of the disc by resonances 10:1, 3:1, and 2:1, while the maximum disc size is larger than the Roche lobe of the primary and smaller than the closest approach of the neutron star. We find correlation between equivalent width of H-alpha emission line ($W\alpha$) and the X-ray flux, which is visible when $15 \: \AA \: < W\alpha \le 40 \: \AA$. The correlation is probably due to wind Roche lobe overflow.Comment: Accepted for publication in Astronomy & Astrophysic

OPTIMAL WEIGHT AND DIALYSIS DOSE IN PATIENTS ON PERIODIC HEMODIALYSIS

Small patients tend to be better dialyzed than large ones. We analyzed the delivered dose of dialysis in two groups of patients - group A, body weight over 50 kg (n-39, m:f=28:l; 57,4 8,3 kg) and group B, body weight under 50 kg (n=15, m:f=6:9; 45,4 3,4 kg). We calculated KT/V and Time Average Concentration of urea (TAC) using two-pool method for urea kinetic modeling. The patients from group Ð’ had a higher KT/V urea =1,35 0,25 (p < 0,05) and lower TAC =13,7 2,72 (p < 0,05) with a shorter dialysis time. Mean serum protein and albumin levels for a year did not differ

Correlations for pairs of periodic trajectories for open billiards

In this paper we prove two asymptotic estimates for pairs of closed trajectories for open billiards similar to those established by Pollicott and Sharp for closed geodesics on negatively curved compact surfaces. The first of these estimates holds for general open billiards in any dimension. The more intricate second estimate is established for open billiards satisfying the so called Dolgopyat type estimates. This class of billiards includes all open billiards in the plane and open billiards in $\R^N, N \geq 3$ satisfying some additional conditions

ORIGINAL PC PROGRAM FOR DETERMINATION OF THE DIALYSIS DOSE AND NUTRITIONAL STATUS OF PATIENTS ON CHRONIC HAEMODIALYSIS

An original PC program created in the Centre for Haemodialysis, Clinic of Nephrology, Haemodialysis and Toxicology, Medical University of Varna, and designed for determination of the dialysis dose and nutritional status of patients on periodic haemodialysis (PHD) was presented. The study covered 58 patients on PHD, 24 females and 34 males monitored at 3-month intervals for one year. Using a PC software and this program the following parameters were estimated: single pool model - KT/Vsp, urea reduction rate (URR), and nutrition status (nPCR). The mean KT/Vsp value (single pool) of 1,13 ± 0,14 was close to that recommended by the Dialysis Outcomes Quality Initiative of the National Kidney Foundation. However, a further optimization of dialysis procedures was required. The mean value of protein intake in these patients during the period of observation was of 1,04 ± 0,13 g/kg/d. It should be emphasized that despite the acceptable mean nPCR value the protein intake remained insufficient in 49 per cent of the cases. There was a positive correlation between KT/V and PCR (r = 0,63; p < 0,05). There was no statistically significant difference between the parameters' values from the urea-kinetic modelling (UKM) and those calculated using authors' PC program that testified to the reliability of the results. This program allowed the prognostication of the necessary dialysis dose by rendering an account of the individual patient's parameters and the ultrafdtration required and then by choosing the optimal values of dialysis duration and blood flow