Report of IAU Commission 30 on Radial Velocities (2006-2009)

Brief summaries are given on the following subjects: Radial velocities and exoplanets (Toward Earth-mass planets; Retired A stars and their planets; Current status and prospects); Toward higher radial velocity precision; Radial velocities and asteroseismology; Radial velocities in Galactic and extragalactic clusters; Radial velocities for field giants; Galactic structure -- Large surveys (The Geneva-Copenhagen Survey; Sloan Digital Sky Survey; RAVE); Working groups (WG on radial velocity standards; WG on stellar radial velocity bibliography; WG on the catalogue of orbital elements of spectroscopic binaries [SB9]).Comment: 11 pages, to appear in the IAU Transactions Vol. XXVIIA, Reports on Astronomy 2006-2009, ed. Karel van der Hucht. Editor: G. Torre

Classical Cepheids and the spiral structure of the Milky Way

We use the currently most complete collection of reliable Cepheid positions (565 stars) out to ~5 kpc based mostly on our photometric data to outline the spiral pattern of our Galaxy. We find the pitch-angle to be equal to 9--10 degrees with the most accurate estimate (i=9.5 +/-0.1 degrees) obtained assuming that the spiral pattern has a four-armed structure, and the solar phase angle in the spiral pattern to be chi_0 = 121+/-3 degrees. The pattern speed is found to be Omega_P=25.2+/-0.5km/s/kpc based on a comparison of the positions of the spiral arms delineated by Cepheids and maser sources and the age difference between these objects.Comment: 21 pages, 11 figures. To appear in Astronomy Letter

In Search of Possible Associations between Planetary Nebulae and Open Clusters

We consider the possibility of cluster membership for 13 planetary nebulae that are located in close proximity to open clusters lying in their lines of sight. The short lifetimes and low sample size of intermediate-mass planetary nebulae with respect to nearby open clusters conspire to reduce the probability of observing a true association. Not surprisingly, line of sight coincidences almost certainly exist for 7 of the 13 cases considered. Additional studies are advocated, however, for 6 planetary nebula/open cluster coincidences in which a physical association is not excluded by the available evidence, namely M 1-80/Berkeley 57, NGC 2438/NGC 2437, NGC 2452/NGC 2453, VBRC 2 & NGC 2899/IC 2488, and HeFa 1/NGC 6067. A number of additional potential associations between planetary nebulae and open clusters is tabulated for reference purposes. It is noteworthy that the strongest cases involve planetary nebulae lying in cluster coronae, a feature also found for short-period cluster Cepheids, which are themselves potential progenitors of planetary nebulae.Comment: Accepted for publication in PASP (December 2007

ДЕМОГРАФИЧЕСКАЯ БЕЗОПАСНОСТЬ РОССИИ И ЕЕ РЕГИОНОВ: ПРОБЛЕМЫ И ПУТИ ИХ РЕШЕНИЯ

The relevance of the article is determined by the critical situation in the population’s mortality rate and health standards as well as by the state of things in the birth rate, marriage and family sphere in the context of threats that the demographic processes instability can bring to the Russian economy as a whole. The article discusses approaches to the concept of «demographic security», analyzes crisis phenomena in the demographic and migration processes and in the human reproduction sphere that threaten the economic growth of Russian regions. The centerpiece of the article is devoted to problems of the contemporary Russia related to alcoholism, drug addiction and smoking. The authors focus on current issues of the family policy and preservation of the family institution in Russia highlighting the problems associated with the spread of informal marriage, the growing number of abandoned children and challenges of adoption and child custody. The authors investigated in detail the issues of the birth rate increase, particularly in the aftermath of the social stratification of Russian society, and pay special attention to the issues of the male working population health maintenance in modern Russia, as well as to gender disproportions in the demographic structure of the population and education. The measures of the demographic and family policy proposed in the article to remedy the situation established in modern Russia can be used by federal and regional government authorities.Актуальность статьи обусловлена уровнем смертности и здоровья населения, ситуацией в сфере рождаемости, а также семьи и брака в контексте угроз, которые может нести нестабильность демографических процессов для экономики Российской Федерации в целом. В статье рассматриваются подходы к понятию «демографическая безопасность», анализируются кризисные явления в демографических и миграционных процессах, в сфере воспроизводства населения, угрожающие экономическому росту регионов России. Центральное место в статье занимают проблемы современной России, связанные с алкоголизацией, наркоманией и табакокурением населения. Особо авторы останавливаются на актуальных вопросах семейной политики, сохранения в России института семьи, подчеркивая проблемы, связанные с распространением практики неюридической брачности, ростом детей-отказников и проблемами усыновления и опеки над детьми в России. Авторами подробно исследуются проблемы повышения рождаемости, в том числе в контексте последствий социального расслоения российского общества, уделяется внимание проблемам сохранения здоровья мужского трудоспособного населения современной России, а также гендерным диспропорциям в демографической структуре населения и образовании. Предложенные в статье меры демографической и семейной политики по исправлению сложившейся в современной России ситуации могут быть использованы органами федеральной и региональной государственной власти

Peculiar Features of the Velocity Field of OB Associations and the Spiral Structure of the Galaxy

Some of the peculiar features of the periodic velocity-field structure for OB associations can be explained by using the model of Roberts and Hausman (1984), in which the behavior of a system of dense clouds is considered in a perturbed potential. The absence of statistically significant variations in the azimuthal velocity across the Carina arm, probably, results from its sharp increase behind the shock front, which is easily blurred by distance errors. The existence of a shock wave in the spiral arms and, at the same time, the virtually free motion of OB associations in epicycles can be reconciled in the model of particle clouds with a mean free path of 0.2-2 kpc. The velocity field of OB associations exhibits two appreciable nonrandom deviations from an ideal spiral pattern: a 0.5-kpc displacement of the Cygnus- and Carina-arm fragments from one another and a weakening of the Perseus arm in quadrant III. However, the identified fragments of the Carina, Cygnus, and Perseus arms do not belong to any of the known types of spurs.Comment: 14 pages, 3 postscript figures, to be published in Astronomy Letter

IN SITU VASCULAR TISSUE REMODELING USING BIODEGRADABLE TUBULAR SCAFFOLDS WITH INCORPORATED GROWTH FACTORS AND CHEMOATTRACTANT MOLECULES

Background Currently, the search for the bioactive molecules capable of promoting formation of the vascular tissue is still ongoing. We have previously demonstrated that incorporation of the growth factors and chemoattractant molecules into the biodegradable tubular scaffolds can increase their primary patency upon the implantation into rat abdominal aorta. However, further studies are required to investigate tissue remodeling using functionalized vascular grafts with the same diameter as a replaced native vessel. Aim To investigate the specific aspects of de novo vascular tissue formation and calcification employing rat abdominal aorta interposition model and vascular grafts with 1.5 mm diameter with incorporated vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor (SDF)-1α. Methods Tubular grafts with a diameter of 1.5 mm were blended of poly(3-hydroxybutyrateco-3-hydroxyvalerate) and poly(ε-caprolactone) (PHBV/PCL). Grafts without growth factors were fabricated using standard electrospinning technique whilst grafts with incorporated growth factors were prepared utilizing emulsion electrospinning. VEGF was incorporated into the inner third, whereas bFGF and SDF-1α were incorporated into the outer two-thirds of the graft. Grafts were implanted into the abdominal aortas of Wistar rats for 1, 3, 6, and 12 months following scanning electron microscopy along with histological and immunofluorescent examination. Results Primary patency of the grafts with VEGF, bFGF, and SDF-1α reached 93% indicative of structural integrity of the vascular tissue. Neither signs of inflammation nor severe calcification was detected. Conclusion As in 2 mm diameter vascular grafts, incorporation of bioactive factors into 1.5 mm diameter grafts increased their long-term primary patency and improved vascular tissue formation in comparison with non-modified grafts.  Background Currently, the search for the bioactive molecules capable of promoting formation of the vascular tissue is still ongoing. We have previously demonstrated that incorporation of the growth factors and chemoattractant molecules into the biodegradable tubular scaffolds can increase their primary patency upon the implantation into rat abdominal aorta. However, further studies are required to investigate tissue remodeling using functionalized vascular grafts with the same diameter as a replaced native vessel. Aim To investigate the specific aspects of de novo vascular tissue formation and calcification employing rat abdominal aorta interposition model and vascular grafts with 1.5 mm diameter with incorporated vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor (SDF)-1α. Methods Tubular grafts with a diameter of 1.5 mm were blended of poly(3-hydroxybutyrateco-3-hydroxyvalerate) and poly(ε-caprolactone) (PHBV/PCL). Grafts without growth factors were fabricated using standard electrospinning technique whilst grafts with incorporated growth factors were prepared utilizing emulsion electrospinning. VEGF was incorporated into the inner third, whereas bFGF and SDF-1α were incorporated into the outer two-thirds of the graft. Grafts were implanted into the abdominal aortas of Wistar rats for 1, 3, 6, and 12 months following scanning electron microscopy along with histological and immunofluorescent examination. Results Primary patency of the grafts with VEGF, bFGF, and SDF-1α reached 93% indicative of structural integrity of the vascular tissue. Neither signs of inflammation nor severe calcification was detected. Conclusion As in 2 mm diameter vascular grafts, incorporation of bioactive factors into 1.5 mm diameter grafts increased their long-term primary patency and improved vascular tissue formation in comparison with non-modified grafts

Leading Wave as a Component of the Spiral Pattern of the Galaxy

The spiral pattern of the Galaxy identified by analyzing the kinematics of young stars within 3 kpc of the Sun is Fourier decomposed into spiral harmonics. The spiral pattern of the Galaxy is shown to be representable as a superposition of trailing and leading waves with interarm distances of 1.8(+/-0.4) kpc and 4(+/-2) kpc, respectively. Shock waves are probably present only in the portions of the trailing spiral pattern where it crosses the crest of the leading wave. The small interarm distance of the trailing spiral wave (1.8 kpc) can be explained by its evolution - by the decrease in the interarm distance as the wave is displaced toward the inner Lindblad resonance. The Carina arm may be part of this resonance ring.Comment: 17 pages, 4 figures, to be published in Astronomy Letters, 200

Periodic Pattern in the Residual-Velocity Field of OB Associations

An analysis of the residual-velocity field of OB associations within 3 kpc of the Sun has revealed periodic variations in the radial residual velocities along the Galactic radius vector with a typical scale length of lambda=2.0(+/-0.2) kpc and a mean amplitude of fR=7(+/-1) km/s. The fact that the radial residual velocities of almost all OB-associations in rich stellar-gas complexes are directed toward the Galactic center suggests that the solar neighborhood under consideration is within the corotation radius. The azimuthal-velocity field exhibits a distinct periodic pattern in the region 0<l<180 degrees, where the mean azimuthal-velocity amplitude is ft=6(+/-2) km/s. There is no periodic pattern of the azimuthal-velocity field in the region 180<l<360 degrees. The locations of the Cygnus arm, as well as the Perseus arm, inferred from an analysis of the radial- and azimuthal-velocity fields coincide. The periodic patterns of the residual-velocity fields of Cepheids and OB associations share many common features.Comment: 21 page

BIOMECHANICAL REMODELING OF BIODEGRADABLE SMALL-DIAMETER VASCULAR GRAFTS IN SITU

Aim: to evaluate the biomechanical remodeling of polymer grafts modified with vascular endothelial growth factor (VEGF) after implantation into rat abdominal aorta.Materials and methods. Vascular grafts of2 mmdiameter were fabricated by electrospinning from polycaprolactone (PCL) and a mixture of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) and PCL. The grafts were modified with VEGF by biphasic electrospinning. Morphology of the grafts was assessed by scanning electron microscopy. Physico-mechanical properties of PCL and PHBV/PCL grafts were estimated using uniaxial tensile test and physiological circulating system equipped with state-of-theart ultrasound vascular wall tracking system. Physico-mechanical testing of PCL/VEGF and PHBV/PCL/VEGF was performed before and after implantation into rat abdominal aorta for 6 months. The modeling of coronary artery bypass grafting (CABG) was performed by finite element analysis for modified grafts.Results. Durability of PCL and PHBV/PCL grafts did not differ from that of human internal mammary artery; however, elasticity and stiffness of these grafts were higher compared to internal mammary artery. Viscoelastic properties of the grafts were comparable to those of native blood vessels. Modification of the grafts with VEGF reduced material stiffness. Six months postimplantation, PCL/VEGF and PHBV/PCL/VEGF were integrated with aortic tissue that induced changes in the physico-mechanical properties of the grafts similar to the native vessel. Biomechanical modeling confirmed the functioning of modified grafts in bypass position for CABG.Conclusion. PCL/VEGF and PHBV/PCL/VEGF grafts have satisfactory physico-mechanical properties and can be potentially used in the reconstruction of blood vessels