Carbon Recombination Lines from the Galactic Plane at 34.5 & 328 MHz

We present results of a search for carbon recombination lines in the Galaxy at 34.5 MHz (C$575\alpha$) made using the dipole array at Gauribidanur near Bangalore. Observations made towards 32 directions, led to detections of lines in absorption at nine positions. Followup observations at 328 MHz (C$272\alpha$) using the Ooty Radio Telescope detected these lines in emission. A VLA D-array observation of one of the positions at 330 MHz yielded no detection implying a lower limit of 10' for the angular size of the line forming region. The longitude-velocity distribution of the observed carbon lines indicate that the line forming region are located mainly between 4 kpc and 7 kpc from the Galactic centre. Combining our results with published carbon recombination line data near 76 MHz (\nocite{erickson:95} Erickson \et 1995) we obtain constraints on the physical parameters of the line forming regions. We find that if the angular size of the line forming regions is $\ge 4^{\circ}$, then the range of parameters that fit the data are: \Te $= 20-40$ K, \ne $\sim 0.1-0.3$ \cm3 and pathlengths $\sim 0.07-0.9$ pc which may correspond to thin photo-dissociated regions around molecular clouds. On the other hand, if the line forming regions are $\sim 2^{\circ}$ in extent, then warmer gas (\Te $\sim 60-300$ K) with lower electron densities (\ne $\sim 0.03-0.05$ \cm3) extending over several tens of parsecs along the line of sight and possibly associated with atomic \HI gas can fit the data. Based on the range of derived parameters, we suggest that the carbon line regions are most likely associated with photo-dissociation regions.Comment: To appear in Journal of Astrophysics & Astronomy, March 200

Determination of the primordial helium abundance from radio recombination line observations: New data. The source W51

Observations of H and He radio recombination lines in the source W51 have been performed with the RT-22 radio telescope (Pushchino) in two transitions: 56α (8 mm) and 65α (13 mm). We have estimated the spectral line parameters and determined the relative abundance of ionized helium, y + = (9.3 ± 0.35)%. We have carried out a model study of the correction (R) for the ionization structure of HII regions (when passing from the observed y + = N(He+)/N(H+) to the actual y = N(He)/N(H)) as a function of the spectral type of the ionizing star. Hence it follows that it is desirable to choose the sources excited by hot stars of spectral types no later than O6 V to estimate the helium abundance. In this case, the correction is expected to be small and essentially constant, R in the range 1.0-1.05. We have analyzed the correction for the ionization structure of W51, obtained an actual abundance of helium in the range y = (8.9-9.7)%, and determined its primordial abundance Y p (produced during primordial nucleosynthesis in the Universe) in this source. We have made a new estimate of the primordial helium abundance from six Galactic HII regions, where we observed H and He radio recombination lines at different times. The weighted mean Y p = 25.64(±0.70)% has been obtained. On the one hand, this value of Y p does not yet disagree strongly with the conclusions of the standard cosmologicalmodel, but, on the other hand, it admits the existence of at least one unknown light particle in the period of primordial nucleosynthesis outside the scope of the standard cosmological model. One should continue to refine Y p for more reliable conclusions to be reached. © 2013 Pleiades Publishing, Inc

THE SPECIFICITY OF THE OVARIAN RESERVE OF WOMEN WITH CHRONIC SALPINGOOPHORITIS

Aim. The research was conducted for the assessment of the impact of chronic salpingoophoritis on the ovarian reserve of women in various phases of reproductive age.Materials and methods. A prospective, controlled and open cohort study was performed in 2013-2018 (n=202). The main group consisted of women with chronic salpingoophoritis (ChrSO) who applied for preconception consultation (n=138). In accordance with the reproductive age phase, the main group was divided into subgroups: the early reproductive age period (ERP, n=44), the peak reproductive age period (PRP, n=56), the late reproductive period (LRP, n=38). The control group consisted of conditionally healthy women of reproductive age (n=64). The ovarian reserve (OR) was estimated on the basis of the serum level of antimullerian hormone (AMH), inhibin B, estradiol, follicle stimulating hormone (FSH), an ultrasoundbased assessment of the number of antral follicles (AF), and the ovarian volume. Results. The age of women ranged from 18 to 40 years. Based on the discriminant analysis, it was found that the main indicators determining the specificity of the OR in ChrSO, depending on the phase of reproductive age, are the number of antral follicles, estradiol level and AMH (Wilks’ lambda = 0.35503, p<0.0001). The specificity of the OR of women with ChrSO (difference from the control group), regardless of the phase of reproductive age, initially and when evaluated after 6 months, is determined by the number of AF and the level of estradiol and AMH; the number of AF and AMH is determined with a similar estimate after 12 months. The specificity of the OR in ChrSO, which is dependent on the reproductive age phase, has been proved through the analysis with the neural networks training(the proportion of correct answers is more than 80%). The linear relationships were established between the values of each OR parameter in women with ChrSO. Initially, when estimating after 6 and 12 months, linear regression equations were calculated, allowing the values of individual OR parameters to be calculated over 6 and 12 months.Conclusion. Chronic salpingoophoritis (ChrSO) is associated with a decrease in ovarian reserve in women of reproductive age. The effect of ChrSO on some parameters of the ovarian reserve depends on the age phase of the reproductive period, which increases with time (after 6, 12 months). The presence of ChrSO in women planning future pregnancies requires preventive and therapeutic measures aimed at preserving the ovarian reserve and the preferred implementation of fertility in early reproductive age before the ovarian reserve starts to decline