Radioastron flight operations

Radioastron is a space-based very-long-baseline interferometry (VLBI) mission to be operational in the mid-90's. The spacecraft and space radio telescope (SRT) will be designed, manufactured, and launched by the Russians. The United States is constructing a DSN subnet to be used in conjunction with a Russian subnet for Radioastron SRT science data acquisition, phase link, and spacecraft and science payload health monitoring. Command and control will be performed from a Russian tracking facility. In addition to the flight element, the network of ground radio telescopes which will be performing co-observations with the space telescope are essential to the mission. Observatories in 39 locations around the world are expected to participate in the mission. Some aspects of the mission that have helped shaped the flight operations concept are: separate radio channels will be provided for spacecraft operations and for phase link and science data acquisition; 80-90 percent of the spacecraft operational time will be spent in an autonomous mode; and, mission scheduling must take into account not only spacecraft and science payload constraints, but tracking station and ground observatory availability as well. This paper will describe the flight operations system design for translating the Radioastron science program into spacecraft executed events. Planning for in-orbit checkout and contingency response will also be discussed

Giant Pulses from PSR B1937+21 with widths <= 15 nanoseconds and T_b >= 5 x 10^39 K, the Highest Brightness Temperature Observed in the Universe

Giant radio pulses of the millisecond pulsar B1937+21 were recorded with the S2 VLBI system at 1.65 GHz with NASA/JPL's 70-m radio telescope at Tidbinbilla, Australia. These pulses have been observed as strong as 65000 Jy with widths <= 15 ns, corresponding to a brightness temperature T_b >= 5 x 10^39 K, the highest observed in the universe. The vast majority of these pulses occur in a 5.8 mcs and 8.2 mcs window at the very trailing edges of the regular main pulse and interpulse profiles, respectively. Giant pulses occur in general with a single spike. Only in one case out of 309 was the structure clearly more complex. The cumulative distribution is fit by a power law with index -1.40 +/- 0.01 with a low-energy but no high-energy cutoff. We estimate that giant pulses occur frequently but are only rarely detected. When corrected for the directivity factor, 25 giant pulses are estimated to be generated in one neutron star revolution alone. The intensities of the giant pulses of the main pulses and interpulses are not correlated with each other nor with the intensities or energies of the main pulses and interpulses themselves. Their radiation energy density can exceed 300 times the plasma energy density at the surface of the neutron star and can even exceed the magnetic field energy density at that surface. We therefore do not think that the generation of giant pulses is linked to the plasma mechanisms in the magnetosphere. Instead we suggest that it is directly related to discharges in the polar cap region of the pulsar.Comment: 14 pages, 13 figures, to be published in ApJ, November 2004, v. 616, also was presented in Russian National Astronomical Conference VAK-2004, "Horizons of the Universe" held in Moscow State University, Sternberg Astronomical Institute, June 3-10, 2004, page 19

Total linear polarization in the OH maser W75N: VLBA polarization structure

W75N is a star-forming region containing various ultracompact HII regions and OH, water, and methanol maser emission. Our VLBA map shows that the OH masers are located in a thin disk rotating around an O-star which is the exciting star of the ultracompact HII region VLA1. A separate set of maser spots is connected with the ultracompact HII region VLA2. The radial velocity of OH maser spots varies across the disk from 3.7 km/s to 10.9 km/s. The diameter of the disk is 4000 A.U. All maser spots are strongly polarized. This are the first OH masers showing nearly 100 per cent linear polarization in several spots. Two maser spots seem to be Zeeman pairs corresponding to a magnetic field of 5.2 mgauss and 7.7 mgauss, and in one case we tentatively found a Zeeman pair consisting of two linearly polarized components. The linearly polarized maser spots are shown to be sigma-components which is the case of the magnetic field being perpendicular to the line of sight. The direction of the magnetic field as determined from linearly polarized spots is perpendicular to the plane of the disk, although the galactic Faraday rotation may significantly affect this conclusion.Comment: 14 figures, 1 table, 27 pages. accepted for publication in ApJ, scheduled for v.564, N1, 200

Space-VLBI observations of OH maser OH34.26+0.15: low interstellar scattering

We report on the first space-VLBI observations of the OH34.26+0.15 maser in two main line OH transitions at 1665 and 1667 MHz. The observations involved the space radiotelescope on board the Japanese satellite HALCA and an array of ground radio telescopes. The map of the maser region and images of individual maser spots were produced with an angular resolution of 1 milliarcsec which is several times higher than the angular resolution available on the ground. The maser spots were only partly resolved and a lower limit to the brightness temperature 6x10^{12} K was obtained. The maser seems to be located in the direction of low interstellar scattering, an order of magnitude lower than the scattering of a nearby extragalactic source and pulsar.Comment: 8 pages, 2 tables, 9 figures, accepted for publication in MNRA

МУКОЛИТИКИ В ТЕРАПИИ БРОНХОЛЕГОЧНОЙ ДИСПЛАЗИИ

Mucolytic drugs, particularly, direct action mucolytics with acetylcysteine derivatives among them, are included in the complex therapy of the bronchopulmonary dysplasia exacerbations. However, data on application effectiveness and safety of such a therapy with chronic bronchopulmonary diseases in children of 0–2 years of age are few and contradictory. The article contains proprietary clinical functional data on application of acetylcysteine in granules for the syrup preparation in the treatment of children bronchopulmonary dysplasia.В комплексную терапию обострений бронхолегочной дисплазии наряду с ингаляционными кортикостероидами и антибиотиками входят муколитические препараты, в частности муколитики прямого действия, к которым относятся производные ацетилцистеина. Однако, данные об эффективности и безопасности применения такой терапии при хронических бронхолегочных заболеваниях у детей первых двух лет жизни малочисленны и разноречивы. Статья содержит собственные клинико-функциональные данные о применении ацетилцистеина в гранулах для приготовления сиропа при лечении детей с бронхолегочной дисплазией.

Pulsar microstructure and its quasi-periodicities with the S2 VLBI system at a resolution of 62.5 nanoseconds

We report on a study of microstructure and its quasi-periodicities of three pulsars at 1.65 GHz with the S2 VLBI system at a resolution of 62.5 ns, by far the highest for any such statistical study yet. For PSR B1929+10 we found in the average cross-correlation function (CCF) broad microstructure with a characteristic timescale of 95+-10 mcs and confirmed microstructure with characteristic timescales between 100 and 450 mcs for PSRs B0950+08 and B1133+16. On a finer scale PSRs B0950+08, B1133+16 (component II) and B1929+10 show narrow microstructure with a characteristic timescale in the CCFs of ~10 mcs, the shortest found in the average CCF or autocorrelation function (ACF) for any pulsar, apart perhaps for the Crab pulsar. Histograms of microstructure widths are skewed heavily toward shorter timescales but display a sharp cutoff. The shortest micropulses have widths between 2 and 7 mcs. No nanopulses or unresolved pulse spikes were detected. Cross-power spectra of single pulses show a large range of complexity with single spectral features representing classic quasi-periodicities and broad and overlapping features with essentially no periodicities at all. Significant differences were found for the two components of PSR B1133+16 in every aspect of our statistical analysis of micropulses and their quasi-periodicities. Asymmetries in the magnetosphere and the hollow cone of emission above the polar cap of the neutron star may be responsible for these differences.Comment: 18 pages, 11 figures, 3 tables, A&A, 2001, accepte

ИММУНОПРОФИЛАКТИКА ТЯЖЕЛОГО ТЕЧЕНИЯ РЕСПИРАТОРНО-СИНЦИТИАЛЬНОЙ ВИРУСНОЙ ИНФЕКЦИИ У ДЕТЕЙ С БРОНХОЛЕГОЧНОЙ ДИСПЛАЗИЕЙ: РЕЗУЛЬТАТЫ ЧЕТЫРЕХ ЭПИДЕМИЧЕСКИХ СЕЗОНОВ

Children with bronchopulmonary dysplasia belong to the risk group of severe respiratory-syncytial viral infection (RSV). World experience and authors' own clinical data show that seasonal immunoprophylaxis of RSV infection's severe course by palivizumab in these patients allows reducing frequency of hospitalizations, CPR conduct and fatal outcomes. The article gives data of clinical instrumental evaluation of efficacy and safety of palivizumab use in the 3 past and the 4th (current) epidemic seasons.Дети с бронхолегочной дисплазией относятся к группе риска тяжелого течения респираторно-синцитиальной вирусной (РСВ) инфекции. Мировой опыт и собственные клинические данные показывают, что сезонная иммунопрофилактика тяжелого течения РСВ инфекции паливизумабом у этих больных позволяет уменьшить частоту госпитализаций, проведения реанимационных мероприятий и летальных исходов. В статье представлены данные клинико-инструментальной оценки эффективности и безопасности применения препарата паливизумаб в течение трех прошедших и четвертого текущего эпидемических сезонов.

КОМПЛЕКСНАЯ ДИАГНОСТИКА И КОРРЕКЦИЯ НАРУШЕНИЙ СНА У ДЕТЕЙ

The article is devoted to the actual problem of modern pediatrics and neurology ― a comprehensive diagnosis and correction of sleep disorders in children. Detail the features of the clinical manifestations of sleep disorders in childhood (insomnia and parasomnia), great attention is paid to sleep apnea syndrome as a risk factor for somatic and psychopathological disorders in children. Highlight the current capabilities of complex instrumental diagnosis of sleep disorders with the use of highly effective methods of polysomnography and pulse oximetry. The actual dimensions as non-drug and drug treatment of sleep disorders in children, taking into account the pathogenetic features of their occurrence. From the standpoint of evidence-based medicine demonstrate efficient methods of herbal medicine, developed on the basis of traditional Chinese recipes, as well as modern nootropics and magnesium preparations. It is shown that sleep disorders in children not only lead to a deterioration of emotional mood, cognitive function, health and school performance, but also are associated with increasing risk of somatic disorders, which determines the need for timely diagnosis and comprehensive differentiated medical and psychological data correction of pathological conditions, taking into account the neurophysiological and biochemical mechanisms of their development, as well as polymorphism of clinical manifestations, in order to increase the effectiveness of treatment and quality of life of patients.  Статья посвящена актуальной проблеме современной педиатрии и неврологии ― комплексной диагностике и коррекции нарушений сна у детей. Подробно рассмотрены особенности клинических проявлений расстройств сна в детском возрасте (инсомний и парасомний), большое внимание уделено синдрому обструктивного апноэ сна как фактору риска развития соматических и психопатологических нарушений у детей. Освещены современные возможности комплексной инструментальной диагностики расстройств сна с применением высокоэффективных методов полисомнографии и пульсоксиметрии, а также актуальные аспекты как немедикаментозной, так и лекарственной терапии нарушений сна в детском возрасте с учетом патогенетических особенностей их возникновения. С позиций доказательной медицины продемонстрирована высокая эффективность способов фитотерапии, разработанных на основе традиционных китайских рецептов, а также современных ноотропных средств и препаратов магния. Показано, что расстройства сна у детей не только приводят к ухудшению эмоционального настроя, когнитивных функций, работоспособности и школьной успеваемости, но и сопряжены с нарастающим риском развития соматических нарушений, что определяет необходимость проведения своевременной диагностики и комплексной дифференцированной медико-психологической коррекции данных патологических состояний с учетом нейрофизиологических и биохимических механизмов их развития, а также полиморфизма клинических проявлений с целью повышения эффективности лечения и улучшения качества жизни пациентов.