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1

Seismology of Evolved Beta Scuti Stars and the Binary BQ CNC in the Praesepe Cluster  

NASA Astrophysics Data System (ADS)

Three d Scuti stars of Praesepe cluster (BT Cnc, KW 284 and EP Cnc) seem to be at the end of the hydrogen core burning in the subgiant phase. This is supported by the fitting of isochrones to the cluster and by the larger period of their pulsations compared to the other delta Scuti stars in the cluster. After the results obtained in a joint identification of the radial modes for four less evolved delta Scuti stars, we try to find a consistent identification of the modes in these three evolved stars. BQ Cnc is another delta Scuti star in Praesepe catalogued as a double-lined spectroscopic binary. Considering different assumptions about the real position of the isolated pulsating star in the HR diagram, we present the most plausible identification of their modes according to the results obtained for the other stars.

Hernandez, M. M.; Perez Hernandez, F.; Michel, E.; Belmonte, J. A.; Goupil, M. J.; Lebreton, Y.

2

RS CVn stars - Chromospheric phenomena  

NASA Astrophysics Data System (ADS)

The observational information regarding chromospheric emission features in surface-active RS CVn stars is reviewed. Three optical features are considered in detail: Ca II H and K, Balmer H-alpha and He I 10830 A. While the qualitative behavior of these lines is in accord with solar-analogy/rotation-activity ideas, the quantitative variation and scaling are very poorly understood. In many cases, the spectroscopic observations with sufficient SNR and resolution to decide these questions have simply not yet been made. The FK Com stars, in particular, present extreme examples of rotation that may well tax present understanding of surface activity to its limits.

Bopp, B. W.

3

The Role of Oxygen Abundances in Exoplanet Host Star C/O Ratios: A Case Study of 55 Cnc  

NASA Astrophysics Data System (ADS)

We derive the C/O ratio for the exoplanet host star 55 Cnc based on archive Keck/HIRES spectra. The C/O ratio varies widely depending on which oxygen abundance indicator - the 6300.3 Å [O I] line, the 6363.8 Å [O I] line, or the 7774 Å O I triplet - is used, and we find there is still a large uncertainty even based on individual abundance indicators. This case study demonstrates that caution and care are necessary when determining exoplanet host star C/O ratios, and when considering host star C/O ratios in inferring exoplanet compositions.

Teske, Johanna K.; Cunha, Katia; Smith, Verne V.; Schuler, Simon C.; Griffith, Caitlin A.

2014-01-01

4

Short-Period RS CVn Stars: Starspots and Fundamental Properties. Abstract Only.  

National Technical Information Service (NTIS)

A computer analysis was performed of selected V-band light curves of systems in the short-period RS CVn group: UV Psc, XY UMa, RT And, SV Cam, BH Vir, ER Vul, WY Cnc, and CG Cyg. For each set of photometric data, researchers fitted a model of a light curv...

E. Budding M. Zeilik

1987-01-01

5

MOA-2010-BLG-523: 'FAILED PLANET' = RS CVn STAR  

SciTech Connect

The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A {sub max} {approx} 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the light-curve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge.

Gould, A.; Yee, J. C.; Pinsonneault, M. H.; Dong, Subo; Gaudi, B. S.; Hung, L.-W. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)] [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Bond, I. A. [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand)] [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)] [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)] [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Jorgensen, U. G. [Niels Bohr Institutet, Kobenhavns Universitet, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)] [Niels Bohr Institutet, Kobenhavns Universitet, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Greenhill, J. [University of Tasmania, School of Mathematics and Physics, Private Bag 37, Hobart, TAS 7001 (Australia)] [University of Tasmania, School of Mathematics and Physics, Private Bag 37, Hobart, TAS 7001 (Australia); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States)] [Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States); Bensby, T. [Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund (Sweden)] [Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund (Sweden); Allen, W. [Vintage Lane Observatory, Blenheim (New Zealand)] [Vintage Lane Observatory, Blenheim (New Zealand); Almeida, L. A.; Jablonski, F. [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas, 1758 Sao Jose dos Campos, 12227-010 SP (Brazil)] [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas, 1758 Sao Jose dos Campos, 12227-010 SP (Brazil); Bos, M. [Molehill Astronomical Observatory, North Shore (New Zealand)] [Molehill Astronomical Observatory, North Shore (New Zealand); Christie, G. W. [Auckland Observatory, Auckland (New Zealand)] [Auckland Observatory, Auckland (New Zealand); DePoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States)] [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Lee, C.-U. [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Collaboration: muFUN Collaboration; MOA Collaboration; OGLE Collaboration; MiNDSTEp Consortium; RoboNet Collaboration; PLANET Collaboration; and others

2013-02-15

6

Magnetic field topology of the RS CVn star II Pegasi  

NASA Astrophysics Data System (ADS)

Context. The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were reconstructed from the time series of spectropolarimetric observations using the Zeeman Doppler imaging (ZDI) method, often yielding surprising and controversial results. Aims: In this study we follow a long-term evolution of the magnetic field topology of the RS CVn binary star II Peg using a more self-consistent and physically more meaningful modelling approach compared to previous ZDI studies. Methods: We collected high-resolution circular polarisation observations of II Peg using the SOFIN spectropolarimeter at the Nordic Optical Telescope. These data cover 12 epochs spread over 7 years, comprising one of the most comprehensive spectropolarimetric data sets acquired for a cool active star. A multi-line diagnostic technique in combination with a new ZDI code is applied to interpret these observations. Results: We have succeeded in detecting clear magnetic field signatures in average Stokes V profiles for all 12 data sets. These profiles typically have complex shapes and amplitudes of ~10-3 of the unpolarised continuum, corresponding to mean longitudinal fields of 50-100 G. Magnetic inversions using these data reveals evolving magnetic fields with typical local strengths of 0.5-1.0 kG and complex topologies. Despite using a self-consistent magnetic and temperature mapping technique, we do not find a clear correlation between magnetic and temperature features in the ZDI maps. Neither do we confirm the presence of persistent azimuthal field rings found in other RS CVn stars. Reconstruction of the magnetic field topology of II Peg reveals significant evolution of both the surface magnetic field structure and the extended magnetospheric field geometry on the time scale covered by our observations. From 2004 to 2010 the total field energy drastically declined and the field became less axisymmetric. This also coincided with the transition from predominantly poloidal to mainly toroidal field topology. Conclusions: A qualitative comparison of the ZDI maps of II Peg with the prediction of dynamo theory suggests that the magnetic field in this star is produced mainly by the turbulent ?2 dynamo rather than the solar ?? dynamo. Our results do not show a clear active longitude system, nor is there evidence of the presence of an azimuthal dynamo wave. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, at the Spanish Observatorio del Roque de los Muchachos of the Instituto Astrofisica de Canarias.

Kochukhov, O.; Mantere, M. J.; Hackman, T.; Ilyin, I.

2013-02-01

7

An analysis of the light curves of short-period RS Canum Venaticorum stars - Starspots and fundamental properties  

Microsoft Academic Search

An analysis is performed of selected light curves for the short-period RS CVn group: UV Psc, XY UMa, RT And, SV Cam, BH Vir, ER Vul, WY Cnc, and Cg Cyg. The photometric fitting parameters are optimized for the 'distorted' light curves in order to derive the maculation wave for each system. A dark circular spot model is fitted to

E. Budding; M. Zeilik

1987-01-01

8

The identification of H2311 + 77 with HD220140, a probable RS CVn star  

NASA Technical Reports Server (NTRS)

H2311 + 77, one of the bright soft X-ray sources in the sky originally detected with HEAO 1, has been identified in an Exosat imaging observation with a 7.7-mag late-type star, HD220140. The X-ray luminosity and the optical characteristics of this star indicate that it is probably an RS CVn binary system.

Pravdo, S. H.; White, N. E.; Giommi, P.

1985-01-01

9

MAXI/GSC detection of a renewed activity of the RS CVn star IM Peg  

NASA Astrophysics Data System (ADS)

MAXI/GSC observed an X-ray enhancement at a position consistent with that of an RS CVn star IM Peg. The flux started to increase at 06:56:57 UT on July 16th 2014, and dimmed at 14:41:31 UT on the same day.

Kawagoe, A.; Tsuboi, Y.; Fujita, M.; Ueno, S.; Tomida, H.; Nakahira, S.; Kimura, M.; Nakagawa, Y. E.; Mihara, T.; Sugizaki, M.; Morii, M.; Serino, M.; Sugimoto, J.; Takagi, T.; Yoshikawa, A.; Matsuoka, M.; Kawai, N.; Usui, R.; Yoshii, T.; Tachibana, Y.; Yoshida, A.; Sakamoto, T.; Nakano, Y.; Kawakubo, Y.; Ohtsuki, H.; Tsunemi, H.; Sasaki, M.; Negoro, H.; Nakajima, M.; Fukushima, K.; Onodera, T.; Suzuki, K.; Ueda, Y.; Shidatsu, M.; Kawamuro, T.; Hori, T.; Yamauchi, M.; Morooka, Y.; Yamaoka, K.

2014-07-01

10

Pulsation in delta Scuti variables: the case of BR Cnc  

NASA Astrophysics Data System (ADS)

We present the results of a three-year Johnson V and Stromgren uvbybeta photometric study about the delta Sct star BR Cnc. The Fourier analysis of the data suggests four pulsation frequencies for this variable: f_1=24.978, f_2=11.358, f_3=11.808 and f_4=27.914/d. Amplitude variations from year to year are found for each of the frequencies. The most relevant physical parameters of BR Cnc are also derived.

Zhou, A.-Y.; Rodriguez, E.; Rolland, A.; Costa, V.

2002-02-01

11

The Pulsational Behavior of the High Amplitude d Scuti Star RS Gruis  

NASA Astrophysics Data System (ADS)

RS Gruis is a high-amplitude delta Scuti-type variable star with a mean amplitude of almost half a magnitude in V and a period of almost 3.5 hours. The most recent study of this star by Derekas et al. (2009) suggests the presence of a low-mass dwarf star companion close to the variable star with a period of 11.5 days. Rodriguez et al. (1995) have also shown a decreasing rate of the period of dP/Pdt = -10.6 • 10-8 / y. Using an extended dataset comprising BVIc CCD observations acquired at the Astronomical Observatory of the Instituto Copérnico, data from ASAS and HIPPARCOS, and the existing CCD observations in the AAVSO International Database, we have performed an extensive periodgram and times of maximum analysis looking for long term variations. As a preliminary result, we confirmed that the period varies, but, since 1995, instead of decreasing, it has increased. We also found a small peak in the power spectrum in good agreement with the period suggested for the binary companion.

García, J.

2012-06-01

12

New Light Elements for the High Amplitude delta Scuti Star RS Gruis  

NASA Astrophysics Data System (ADS)

Photoelectric and DSLR photometry of the monoperiodic high amplitude delta Scuti star RS Gruis yielded 16 times of maximum determined by the author from 2007 to 2013.These data are combined with historical observations obtained from 1952 to 1988 and more recent observations by others from 2003 to 2010. This combined dataset, comprising 50 times of maximum spanning 61years, was subjected to O-C analysis, which revealed an obvious change in the period of the star between 1988 and 2003. Separate O-C analysis of the data from 2003 to 2013, comprising 28 times of maximum, yielded a quadratic fit, with the pulsational period increasing at the rate of dP/Pdt = 84.95 (15.74) × 10-8 yr-1. To our knowledge, this rate of increase in period is the highest ever reported for a Population I high amplitude delta Scuti star with radial pulsation. From a quadratic (second order polynomial) ephemeris, the period was calculated to be 0.14701118 (0.00000011) d at HJD 2452920 (in October 2003) and 0.14701241 (0.00000012) d at HJD 2456497 (in July 2013).

Axelsen, R. A.

2014-06-01

13

Doppler Imagery of the Spotted RS Canum Venaticorum Star HR 1099 (V711 Tauri) from 1981 to 1992  

Microsoft Academic Search

We present a set of 23 Doppler images of the spotted RS CVn star HR 1099 (V711 Tauri; HD 22468) obtained from 1981 to 1992. HR 1099 shows a large, cool polar spot that has persisted for the 11 yr of this study and other low-latitude spots that come and go on relatively short (less than 1 yr) timescales and

Steven S. Vogt; Artie P. Hatzes; Anthony A. Misch; M. Kürster

1999-01-01

14

The CCD photometric study of the newly identified RS CVn binary star V1034 Hercules  

NASA Astrophysics Data System (ADS)

This paper presents a new CCD Bessell VRcIc light curves and photometric analysis of the newly discovered RS CVn type eclipsing binary star V1034 Her. The light curves were obtained at the Çanakkale Onsekiz Mart University Observatory in 2006. Variations of the orbital period of the system were firstly studied. The ( O - C) diagram with a low range of observing time of about 20 years shows an upward parabola, which indicates a secular increase in the orbital period of the system. The light curves are generally those of detached eclipsing binaries; however, there are large asymmetries between maxima. The VRcIc light curves were analysed with two different fitting procedures: Wilson-Devinney method supplemented with a Monte Carlo type algorithm and Information Limit Optimization Technique (ILOT). Our general results find V1034 Her. as a well detached system, in which the components are filling ˜65% of their Roche lobes. Light curve asymmetries of the system are explained in terms of large dark starspots on the primary component. The primary star shows a long-lived spot distribution with active longitudes in the same hemisphere.

Dog?ru, D.; Erdem, A.; Dog?ru, S. S.

2009-11-01

15

Characterization of the Transiting Super-Earth 55 Cnc e  

NASA Astrophysics Data System (ADS)

The transiting nature of 55 Cnc e has been recently unveiled independently by the MOST satellite in the visible (Winn et al. 2011) and Warm Spitzer in the infrared (Demory et al. 2011). 55 Cnc e is the only transiting super-Earth orbiting a naked eye star, which makes this planet a true Rosetta stone in the field of low-mass exoplanets. We will present new follow-up observations scheduled during Summer 2011 that will provide better constraints on the internal structure and immediate environment of this intriguing super-Earth.

Demory, Brice-Olivier; Gillon, M.; Deming, D.; Seager, S.

2011-09-01

16

The RS CVn Binary HD 155555: A Comparative Study of the Atmospheres for the Two Component Stars  

NASA Technical Reports Server (NTRS)

We present GHRS/HST observations of the RS CVn binary system HD 155555. Several key UV emission lines (Fe XXI, Si IV, O V, C IV) have been analyzed to provide information about the heating rate throughout the atmosphere from the chromosphere to the corona. We show that both the G and K components reveal features of a chromosphere, transition region and corona. The emission measure distribution as a function of temperature for both components is derived and compared with the RS Cvn system, HR 1099, and the Sun. The transition region and coronal lines of both stars show nonthermal broadenings of approx. 20-30 km/s. Possible physical implications for coronal heating mechanisms are discussed.

Airapetian, V. S.; Dempsey, R. C.

1997-01-01

17

Lichtkurve und Periode des RR-Lyrae-Sterns EF Cnc  

NASA Astrophysics Data System (ADS)

Based on data from the SWASP database and on recent observations 28 maxima and 25 minima timings of the RR Lyrae star EF Cnc could be derived. A corrected ephemeris and a CCD lightcurve are given. It is shown that since the availability of CCD maxima from the year 2001 till now, the period remained constant and that the lightcurve is also constant with characteristic double peaked maxima.

Groebel, Rainer

2013-02-01

18

X-ray-selected candidates for the RS CVn and W UMa classes of binary stars  

SciTech Connect

X-ray luminosity, spectral type, radial-velocity variation, rotationally broadened line profile, and Ca II H and K line emission data are used to identify 12 new candidates for the RS CVn class and seven new candidates for the W UMa class from spectroscopic binaries which are contained in the Einstein Extended Medium Sensitivity Survey. Under the assumption that the candidates are genuine members of each class, local space density estimates of 4.47 + or - 1.19 x 10 to the -4th/cu pc for RS CVn binaries and 8.47 + or - 3.00 x 10 to the -5th/cu pc for W UMa binaries are found. Although the density estimate for the W UMa binaries is shown to be consistent with previous estimates obtained from optically selected samples, the estimate for the RS CVn binaries is more than an order of magnitude greater than previously determined space densities. 40 refs.

Fleming, T.A.; Gioia, I.M.; Maccacaro, T. (Joint Institute for Laboratory Astrophysics, Boulder, CO (USA); Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany, F.R.); Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA))

1989-08-01

19

X-ray-selected candidates for the RS CVn and W UMa classes of binary stars  

NASA Technical Reports Server (NTRS)

X-ray luminosity, spectral type, radial-velocity variation, rotationally broadened line profile, and Ca II H and K line emission data are used to identify 12 new candidates for the RS CVn class and seven new candidates for the W UMa class from spectroscopic binaries which are contained in the Einstein Extended Medium Sensitivity Survey. Under the assumption that the candidates are genuine members of each class, local space density estimates of 4.47 + or - 1.19 x 10 to the -4th/cu pc for RS CVn binaries and 8.47 + or - 3.00 x 10 to the -5th/cu pc for W UMa binaries are found. Although the density estimate for the W UMa binaries is shown to be consistent with previous estimates obtained from optically selected samples, the estimate for the RS CVn binaries is more than an order of magnitude greater than previously determined space densities.

Fleming, Thomas A.; Gioia, Isabella M.; Maccacaro, Tommaso

1989-01-01

20

INVESTIGATION FOR THE ENRICHMENT PATTERN OF THE ELEMENT ABUNDANCES IN r+s STAR HE 0338 - 3945: A SPECIAL r-II STAR?  

SciTech Connect

The very metal-poor star HE 0338 - 3945 shows a double-enhanced pattern of the neutron-capture elements. The study of this sample could help people gain a better understanding of s- and r-process nucleosynthesis at low metallicity. Using a parametric model, we find that the abundance pattern of the neutron-capture elements could be best explained by a binary system formed in a molecular cloud that had been polluted by r-process material. The observed abundance pattern of C and N can be explained by an asymptotic giant branch (AGB) model. Combined with the parameters obtained from Cui and Zhang, we suggest that the initial mass of the AGB companion is most likely to be about 2.5 M{sub sun}, which excludes the possibility of forming a Type 1.5 supernova. By comparing with the observational abundance pattern of CS 22892 - 052, we find that the dominant production of O should accompany the production of the heavy r-process elements of r+s stars. Similar to r-II stars, the heavy r-process elements are not produced in conjunction with all the light elements from the Na to Fe group. The abundance pattern of the light and r-process elements for HE 0338 - 3945 is very close to the pattern of the r-II star CS 22892 - 052. Therefore, we suggest that HE 0338 - 3945 should be a special r-II star.

Cui Wenyuan; Zhang Jiang; Zhu Zizhong; Zhang Bo, E-mail: wenyuancui@126.co, E-mail: zhangbo@hebtu.edu.c [Department of Physics, Hebei Normal University, 113 Yuhua Dong Road, Shijiazhuang 050016 (China)

2010-01-01

21

Coordinated optical and ultraviolet observations of short period RS CVn and W UMa type stars  

SciTech Connect

Data from the Fiber Optic Echelle Charge Coupled Device (CCD) Spectrograph at KPNO as well as IUE data were analyzed in this study of short period RS CVn and W UMa type binaries. Optical data were analyzed using a spectral subtraction technique to find excess emission (or absorption) in the component spectra. Analysis of data for the W UMa type contact binary VW Cep strongly suggests the existence of extended material near the contact region but clearly outside the Roche lobes. This material is presumably confined in magnetic loops bridging the two components. Making simple assumptions, the density can be estimated at 4 to 5 times 10 {sup 12} cm (sup {minus}3). A possible prominence was also detected on the secondary component of the detached short period RS CVn system DH Leo.

Newmark, J.S.

1990-01-01

22

L'-Band Interferometric Observations of Evolved Stars  

NASA Astrophysics Data System (ADS)

Ten bright Miras, six semiregular variable giants, and two semiregular variable supergiants have been observed with the Infrared-Optical Telescope Array interferometer in the L' band (from 3.4 to 4.1 ?m). Observations were carried out in 2000 March and November with the FLUOR/TISIS instrument, using optimized single-mode waveguides for optical recombination and a dedicated chopping system for accurate subtraction of slow thermal background drifts. Four of the sources (the Mira stars R Leo and R Cnc, ? Ori, and RS Cnc) were observed in both runs. We report on visibility measurements and derive L' broadband uniform disk (UD) diameter best fits for all 18 stars in our sample. We also detect strong departures from UD models in some peculiar cases.

Chagnon, G.; Mennesson, B.; Perrin, G.; Coudé du Foresto, V.; Salomé, P.; Bordé, P.; Lacasse, M.; Traub, W.

2002-11-01

23

Two decades of optical photometry of short-period eclipsing RS CVn systems and other active chromosphere systems  

NASA Astrophysics Data System (ADS)

I present BVRI photometry of short-period (P < 1d) eclipsing RS CVn binary star systems collected between 1988 and 2009 at Mount Laguna Observatory. Most of the data are for ER Vul and WY Cnc, with light curves nearly every year during that time period. I also present light curves for at least several years for XY UMa, BH Vir, CG Cyg, RT And, and UV Psc. I have fewer light curves for SV Cam, UV Leo, 1E1919+0427, and GSC 2038-0293. In addition to the eclipsing short-period systems, I also include UBVRI data for two longer period noneclipsing RS CVn binary systems: UZ Lib and DM UMa, as well as two active chromosphere single stars: FK Com and HD 199178.

Heckert, Paul A.

2012-05-01

24

Cataclysmic Variables in Open Clusters: EU Cnc  

NASA Astrophysics Data System (ADS)

We present a photometric study of the magnetic cataclysmic variable (MCV) EU Cnc, which is a member of the solar-age/solar-metalicity open cluster M67. A comparison with field and globular cluster MCVs reveals that, although the amplitude of the orbital light curve of EU Cnc corresponds to that of a high polar, the cluster membership (absolute magnitude) of the system implies a low M-dot system. Considering that EU Cnc is the only MCV known in an open cluster, our result suggests that open cluster MCVs may differ from their field and globular cluster counterparts.

Nair, P. H.; Kafka, S.; Honeycutt, R. K.; Gilliland, Ronald L.

2005-01-01

25

NEW EVIDENCE OF MAGNETIC INTERACTIONS BETWEEN STARS FROM THREE-DIMENSIONAL DOPPLER TOMOGRAPHY OF ALGOL BINARIES: {beta} PER AND RS VUL  

SciTech Connect

Time-resolved H{alpha} spectra of magnetically active interacting binaries have been used to create three-dimensional (3D) Doppler tomograms by means of the Radioastronomical Approach. This is the first 3D reconstruction of {beta} Per, with RS Vul for comparison. These 3D tomograms have revealed evidence of the mass transfer process (gas stream, circumprimary emission, localized region, absorption zone), as well as loop prominences and coronal mass ejections (CMEs) in {beta} Per and RS Vul that could not be discovered from two-dimensional tomograms alone. The gas stream in both binaries may have been deflected beyond the central plane by the donor star's magnetic field. The stream was more elongated along the predicted trajectory in RS Vul than in {beta} Per, but not as pronounced as in U CrB (stream state). The loop prominence reached maximum V{sub z} velocities of {+-}155 km s{sup -1} in RS Vul compared to {+-}120 km s{sup -1} in {beta} Per, while the CME reached a maximum V{sub z} velocity of +150 km s{sup -1} in RS Vul and +100 km s{sup -1} in {beta} Per. The 3D tomograms show that the gas flows are not symmetric relative to the central plane and are not confined to that plane, a result confirmed by recent 15 GHz VLBI radio images of {beta} Per. Both the 3D H{alpha} tomography and the VLBI radio images support an earlier prediction of the superhump phenomenon in {beta} Per: that the gas between the stars is threaded with a magnetic field even though the hot B8V mass-gaining star is not known to have a magnetic field.

Richards, Mercedes T. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Agafonov, Michail I.; Sharova, Olga I., E-mail: mrichards@astro.psu.edu, E-mail: agfn@nirfi.sci-nnov.ru, E-mail: shol@nirfi.sci-nnov.ru [Radiophysical Research Institute (NIRFI), 25/12a, Bolshaya Pecherskaya St., Nizhny Novgorod 603950 (Russian Federation)

2012-11-20

26

Rotational modulation and flares on RS Canum Venaticorum and BY Draconis stars. XI - Ultraviolet spectral images of AR Lacertae in September 1985  

NASA Technical Reports Server (NTRS)

High-resolution IUE SWP and LWP spectra of the bright eclipsing RS CVn system AR Lac, obtained during 40 h of continuous observations on September 18-19, 1985, are compiled and used to derive chromosphere images. The data and results are presented graphically and discussed in detail. The K 0 IV star is found to have a globally brighter trailing hemisphere and at least three distinct plage regions; the G 2 IV star has a flaring region with significant redshift and line-emission broadening and exhibits factor-of-3 variability in total emission, attributed to the presence of a large chromospherically inactive region.

Neff, J. E.; Walter, F. M.; Rodono, M.; Linsky, J. L.

1989-01-01

27

Buffered DDA command generation in a CNC  

Microsoft Academic Search

In a computerized numerical controller (CNC), interpolating more than one block in a sampling interval, increases the feed rate. Some commands skipped by the generator are pre-saved in a circular buffer, to provide faster operation than that of a conventional digital differential analyzer. The feed rate can be increased when programmed distances are short. The high feed rate is confirmed

Yih-Fang Chang

2003-01-01

28

MAXI\\/GSC detection of a possible X-ray flare from an RS CVn star GT Mus (=4U1137-65, HD 101379)  

Microsoft Academic Search

On 2010-11-10 06:17:27 UT (= MJD 55510.26211), the MAXI\\/GSC transient alert system triggered on enhanced X-ray emission from the position: (R.A., Dec) = (174.925, 65.498) = (11h 39m 42s, -65d 29m 53s) (J2000) with an error radius (statistical + systematic) of about 0.3 degrees. This location is consistent with that of the RS CVn star GT Mus (=4U 1137-65, HD

M. Nakajima; F. Suwa; H. Negoro; H. Ozawa; T. Matsumura; K. Yamazaki; A. Uzawa; N. Kawai; T. Mihara; M. Serino; M. Sugizaki; Y. E. Nakagawa; T. Yamamoto; T. Sootome; M. Matsuoka; M. Morii; K. Sugimori; R. Usui; S. Ueno; H. Tomida; M. Kohama; M. Ishikawa; A. Yoshida; K. Yamaoka; S. Nakahira; H. Tsunemi; M. Kimura; Y. Ueda; N. Isobe; S. Eguchi; K. Hiroi; M. Shidatsu; A. Daikyuji

2010-01-01

29

SY Cnc, a case for unstable mass transfer?  

NASA Astrophysics Data System (ADS)

Intermediate-resolution (0.5-1 Å) optical spectroscopy of the cataclysmic variable (CV) SY Cnc reveals the spectrum of the donor star. Our data enable us to resolve the orbital motion of the donor and provide a new orbital solution, binary mass ratio and spectral classification. We find that the donor star has spectral-type G8 +/- 2 V and orbits the white dwarf with P = 0.3823753 +/- 0.0000003 d, K2 = 88.0 +/- 2.9 kms-1 and V sini = 75.5 +/- 6.5 kms-1. Our values are significantly different from previous works and lead to q = M2/M1 = 1.18 +/- 0.14. This is one of the highest mass ratios known in a CV and is very robust, because it is based on resolving the rotational broadening over a large number of metallic absorption lines. The donor could be a slightly evolved main sequence or descendant from a massive star which underwent an episode of thermal time-scale mass transfer.

Casares, J.; Martínez-Pais, I. G.; Rodríguez-Gil, P.

2009-11-01

30

Suspension viscosities and shape parameter of cellulose nanocrystals (CNC)  

Microsoft Academic Search

The successful application of nanoscale materials requires an accurate description of the shape and size of the nanomaterial. Cellulose nanocrystals (CNC) are a plant-derived nanomaterial that is currently being investigated for a variety of applications. We have developed here a method to determine the shape parameter (length\\/diameter) of rod-like CNC particles using bulk viscosity measurements of CNC solutions. The cellulose

Yaman Boluk; Roya Lahiji; Liyan Zhao; Mark T. McDermott

2011-01-01

31

BD Andromedae: A New Short-period RS CVn Eclipsing Binary Star with a Distant Tertiary Body in a Highly Eccentric Orbit  

NASA Astrophysics Data System (ADS)

A photometric study of BD And was made through the analysis of two sets of new BVR light curves. The light curves with migrating photometric waves outside eclipse show that BD And is a short-period RS CVn-type binary star. The analysis of all available timings reveals that the orbital period has varied in a strictly cyclical way with a period of 9.2 yr. The periodic variation most likely arises from the light-time effect due to a tertiary moving in a highly elliptical orbit (e 3 = 0.76). The Applegate mechanism could not operate properly in the eclipsing pair. The light curves were modeled with two large spots on the hotter star and a large third light amounting to about 14% of the total systemic light. BD And is a triple system: a detached binary system consisting of two nearly equal solar-type stars with an active primary star and a G6-G7 tertiary dwarf. The absolute dimensions of the eclipsing pair and tertiary components were determined. The three components with a mean age of about 5.8 Gyr are located at midpositions in main-sequence bands. The radius of the secondary is about 17% larger than that deduced from stellar models. The orbital and radiometric characteristics of the tertiary are intensively investigated. One important feature is that the mutual inclination between two orbits is larger than 60°, implying that Kozai cycles had occurred very efficiently in the past. The possible past and future evolutions of the BD And system, driven by KCTF and MBTF, are also discussed.

Kim, Chun-Hwey; Song, Mi-Hwa; Yoon, Jo-Na; Han, Wonyong; Jeong, Min-Ji

2014-06-01

32

VLA Observations of H I in the Circumstellar Envelopes of AGB Stars  

NASA Astrophysics Data System (ADS)

We present the results of a VLA search for H I emission in the circumstellar envelopes of five nearby AGB stars: RS Cnc, IRC+10216, EP Aqr, R Cas, and R Aqr. We have detected emission coincident in both position and velocity with RS Cnc, implying that the emission arises from its extended envelope. For R Cas, we detected weak (5 ?) emission that peaks at the stellar systemic velocity and overlaps with the location of its circumstellar dust shell and thus is probably related to the star. Toward IRC+10216 and EP Aqr, we detected multiple, arcminute-scale H I emission features at velocities consistent with the circumstellar envelopes, but spatially offset from the stellar positions; in these cases we cannot determine unambiguously if the emission is related to the stars. In the case of IRC+10216, we were unable to confirm the detection of H I in absorption against the cosmic background previously reported by Le Bertre & Gérard. We detected our fifth target, R Aqr (a symbiotic binary), in the 1.4 GHz continuum.

Matthews, L. D.; Reid, M. J.

2007-11-01

33

MAXI/GSC detection of a possible X-ray flare from an RS CVn star CF Tuc  

NASA Astrophysics Data System (ADS)

On 2012-01-30 08:25:38 UT (=MJD 55956.351), the MAXI/GSC transient alert system triggered on enhanced X-ray emission from the position consistent with the CF Tuc (RS CVn system). The significant X-ray flux in the 2-20 keV band had been detected at 2012-01-30 03:45 (UT)(=MJD 55956.157) and activity continued about 3 hours. The maximum X-ray flux and the luminosity are about 60 mCrab and 2×1033 ergs/s in 2-20 keV band, respectively, if the distance is assumed to be 89 pc.

Yamamoto, T.; Yamazaki, K.; Tsuboi, Y.; Nakahira, S.; Serino, M.; Mihara, T.; Sugizaki, M.; Sootome, T.; Matsuoka, M.; Ueno, S.; Tomida, H.; Kohama, M.; Ishikawa, M.; Kawai, N.; Morii, M.; Sugimori, K.; Usui, R.; Toizumi, T.; Aoki, Y.; Song, S.; Yoshida, A.; Yamaoka, K.; Tsunemi, H.; Kimura, M.; Kitayama, H.; Negoro, H.; Nakajima, M.; Suwa, F.; Asada, M.; Sakakibara, H.; Ueda, Y.; Hiroi, K.; Shidatsu, M.; Matsumura, T.; Yamauchi, M.; Nishimura, Y.; Hanayama, T.

2012-01-01

34

Advanced CNC Programming (EZ-CAM). 439-366.  

ERIC Educational Resources Information Center

This document contains two units for an advanced course in computer numerical control (CNC) for computer-aided manufacturing. It is intended to familiarize students with the principles and techniques necessary to create proper CNC programs using computer software. Each unit consists of an introduction, instructional objectives, learning materials,…

Casey, Joe

35

Understanding and Writing G & M Code for CNC Machines  

ERIC Educational Resources Information Center

In modern CAD and CAM manufacturing companies, engineers design parts for machines and consumable goods. Many of these parts are cut on CNC machines. Whether using a CNC lathe, milling machine, or router, the ideas and designs of engineers must be translated into a machine-readable form called G & M Code that can be used to cut parts to precise…

Loveland, Thomas

2012-01-01

36

Study of Accuracy of CNC Machine Tools  

NSDL National Science Digital Library

The dimensional accuracies as well as surface finishes of parts produced by a CNC machine tool are strongly dependent on the motion accuracy of each axis of the machine. The overall accuracy of the machine tool is decided by the mechanical characteristics of the machine as well as the characteristics if the control system driving the individual axes. A CNC Machine is programmed to travel along a predetermined or contour, and any deviation from the programmed path is referred as the contouring error. A typical test that is used is a circular test in which the machine is programmed to travel along a circle, and the difference between the programmed path and the measured actual path is compared. The purpose of this study is to identify the various contributors to this contouring error, and in particular estimate the error due to stick slip motion using analytical techniques. It is planned to measure the errors experimentally making use of capacitance probes. The study is intended to develop an appreciation for the sources of different errors produced in a machine tool and as such forms a module in a typical semester long class devoted to manufacturing processes.

Chattopadhyay, Sonnath

2009-09-10

37

Star Images, Star Performances (College Course File).  

ERIC Educational Resources Information Center

Describes a course that focuses attention on the position of the actor, especially the star actor, in cinematic and television signification. Divides the course into three sections: "The Star System,""Stars as Images," and "Star Performance." (RS)

Butler, Jeremy G.

1990-01-01

38

Generation of Gear Tooth Surfaces by Application of CNC Machines.  

National Technical Information Service (NTIS)

This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. ...

F. L. Litvin N. X. Chen

1994-01-01

39

CNC water-jet machining and cutting center. Final report.  

National Technical Information Service (NTIS)

CNC water-jet machining was investigated to determine the potential applications and cost-effectiveness that would result by establishing this capability in the engineering shops of Allied-Signal Inc., Kansas City Division (KCD). Both conductive and nonco...

D. C. Bartlett

1991-01-01

40

Accurate feedrate control of CNC machine tools along NURBS curves  

Microsoft Academic Search

This paper presents a feedrate-controlled interpolator for accurate feedrate control of CNC machine tools along NURBS curves for precision CNC machining. Unlike most existing interpolators, usually based on the Taylor expansion, the proposed method uses an Adams-Moulton predictor-corrector algorithm instead. An upper bound on the sampling interval is established, which guarantees convergence of the corrector iterations (within each interval). Experimental

Chung-Wei Cheng; Mi-Ching Tsai; Jan Maciejowski

2004-01-01

41

The multi-scale environment of RS Cancri from CO and H I observations  

NASA Astrophysics Data System (ADS)

We present a detailed study of the circumstellar gas distribution and kinematics of the semi-regular variable star RS Cnc on spatial scales ranging from ~1'' (~150 AU) to ~6' (~0.25 pc). Our study utilizes new CO1-0 data from the Plateau de Bure Interferometer and new H i 21 cm line observations from the Jansky Very Large Array (JVLA), in combination with previous observations. New modeling of CO1-0 and CO2-1 imaging observations leads to a revised characterization of RS Cnc's previously identified axisymmetric molecular outflow. Rather than a simple disk-outflow picture, we find that a gradient in velocity as a function of latitude is needed to fit the spatially resolved spectra, and in our preferred model, the density and the velocity vary smoothly from the equatorial plane to the polar axis. In terms of density, the source appears quasi-spherical, whereas in terms of velocity the source is axisymmetric with a low expansion velocity in the equatorial plane and faster outflows in the polar directions. The flux of matter is also larger in the polar directions than in the equatorial plane. An implication of our model is that the stellar wind is still accelerated at radii larger than a few hundred AU, well beyond the radius where the terminal velocity is thought to be reached in an asymptotic giant branch star. The JVLA H i data show the previously detected head-tail morphology, and also supply additional details about the atomic gas distribution and kinematics. We confirm that the head seen in H i is elongated in a direction consistent with the polar axis of the molecular outflow, suggesting that we are tracing an extension of the molecular outflow well beyond the molecular dissociation radius (up to ~0.05 pc). The 6'-long H i tail is oriented at a PA of 305°, consistent with the space motion of the star. The tail is resolved into several clumps that may result from hydrodynamic effects linked to the interaction with the local interstellar medium. We measure a total mass of atomic hydrogen MHI ? 0.0055 M? and estimate a lower limit to the timescale for the formation of the tail to be ~6.4 × 104 years. Based on observations carried out with the IRAM Plateau de Bure Interferometer and the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

Hoai, D. T.; Matthews, L. D.; Winters, J. M.; Nhung, P. T.; Gérard, E.; Libert, Y.; Le Bertre, T.

2014-05-01

42

RS Canum Venaticorum  

NASA Astrophysics Data System (ADS)

RSCVn=RS Canum Venaticorum (BD +36° 2344, HD 114519; ?1950.0=13h08m18s, ?1950.0=+36°12'.0; ?d=2.79 s yr-1, ??=-0.319' yr-1) is a detached CLOSE BINARY STAR (F5 V+K2 IV) in the CANES VENATICI constellation (cf Rodonò et al 1995 for a discussion of the spectral classification). In addition to the canonical eclipse-related light variability, early photometric observations had already shown uneven o...

Rodonò, M.; Murdin, P.

2000-11-01

43

Effect of Cellulose Nanocrystals (CNC) Particle Morphology on Dispersion and Rheological and Mechanical Properties of Polypropylene/CNC Nanocomposites.  

PubMed

Polypropylene (PP) nanocomposites containing spray-dried cellulose nanocrystals (CNC), freeze-dried CNC, and spray-freeze-dried CNC (CNCSFD) were prepared via melt mixing in an internal batch mixer. Polarized light, scanning electron, and atomic force microscopy showed significantly better dispersion of CNCSFD in PP/CNC nanocomposites compared with the spray-dried and freeze-dried CNCs. Rheological measurements, including linear and nonlinear viscoelastic tests, were performed on PP/CNC samples. The microscopy results were supported by small-amplitude oscillatory shear tests, which showed substantial rises in the magnitudes of key rheological parameters of PP samples containing CNCSFD. Steady-shear results revealed a strong shear thinning behavior of PP samples containing CNCSFD. Moreover, PP melts containing CNCSFD exhibited a yield stress. The magnitude of the yield stress and the degree of shear thinning behavior increased with CNCSFD concentration. It was found that CNCSFD agglomerates with a weblike structure were more effective in modifying the rheological properties. This effect was attributed to better dispersion of the agglomerates with the weblike structure. Dynamic mechanical analysis showed considerable improvement in the modulus of samples containing CNCSFD agglomerates. The percolation mechanical model with modified volume percolation threshold and filler network strength values and the Halpin-Kardos model were used to fit the experimental results. PMID:24809661

Khoshkava, Vahid; Kamal, Musa R

2014-06-11

44

Determination of Optimal Parameters for SKD11 CNC Turning Process  

Microsoft Academic Search

This study investigated the optimization of a CNC turning process for SKD11 (JIS). The design of experiments (DOE) method with an orthogonal array was applied. Nine experimental runs were performed based on the orthogonal array. The surface properties of roughness average and roughness maximum and the roundness were studied; the analysis of variance (ANOVA) was adapted to investigate which parameters

Chorng-Jyh Tzeng; Yung-Kuang Yang

2008-01-01

45

Searching for Flickering Variability in Several Symbiotic Stars and Related Objects: BX Mon, V471 Per, RS Oph, V627 Cas, CI Cam, V886 Her, Z And, T CrB, MWC 560, V407 Cyg  

NASA Astrophysics Data System (ADS)

UBVRI photometric observations of 10 symbiotic stars and related objects obtained in the period 2002-2003 are presented. Analyzing differential light curves we found rapid light variations with timescales of tens of minutes and significant amplitudes in the well-known flickers MWC 560, RS Oph, V407 Cyg and T CrB. MWC 560 and V407 Cyg demonstrate quasi periodic oscillations (QPO) with similar amplitudes and timescales. Flickering and unusual flare in V627 Cas as well as some indications of flickering presence in BX Mon are detected. The existence of 29 min oscillations in Z And with an amplitude approx 0.02 mag in the U-band is confirmed. Only one symbiotic star, V471 Per, and both non symbiotic, CI Cam and V886 Her, seem to be constant on flickering timescales. Nevertheless, small night to night changes in the brightness of V886 Her were observed as well.

Gromadzki, M.; Mikolajewski, M.; Tomov, T.; Bellas-Velidis, I.; Dapergolas, A.; Galan, C.

2006-03-01

46

Generation of gear tooth surfaces by application of CNC machines  

NASA Technical Reports Server (NTRS)

This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

Litvin, F. L.; Chen, N. X.

1994-01-01

47

Rotational modulation and flares on RS CVn and BY Dra stars. VI - Physical parameters of the chromospheres/transition regions of V 711 Tau (HR 1099), II Peg and AR Lac during October 1981  

NASA Technical Reports Server (NTRS)

Ground-based optical and IUE satellite-ultraviolet observations of three RS CVn stars are combined with density sensitive line ratios and differential emission measure curves to describe the physical conditions in their outer atmospheres. Solar-like densities are found to be representative of average conditions on two of the stars, V 711 Tau and AR Lac. The total radiative losses from these two stars are estimated and found to be larger than the sun by at least two orders of magnitude. Consideration of the volume emitting in two of the principal transition region lines suggests a possible relation between the disk 'filling factor' for these two lines and the dynamo-related Rossby number. Only one hemisphere of the star II Peg, the one showing least evidence of starspots, is similar. On the opposite hemisphere the presence of a discrete emitting region is deduced which is almost coincident in phase with the passage of the dominant optical spot group across the visible disk. The dimensions of this region, and an illustrative interpretation in terms of a large emitting magnetic loop, are discussed. It is compared to large active region loops on the sun.

Byrne, P. B.; Doyle, J. G.; Brown, A.; Linsky, J. L.; Rodono, M.

1987-01-01

48

Catalogue of Main Characteristics of Pulsations of 173 Semi-Regular Stars  

NASA Astrophysics Data System (ADS)

The characteristics of brightness variations of 173 semi-regular stars are tabulated: the moments and brightness of the extrema; the effective periods, amplitudes and significance obtained by using different methods: a) the periodogram analysis (harmonic least squares t) with prewhitening to determine characteristics and significance of waves with 3 periods; b) the wavelet analysis to determine characteristics of statistically significant waves; ) the "running parabola" scalegram analysis to determine the optimal filter half - width for smoothing. The characteristics may be used for more precise classification of semi-regular variables. Characteristics of the 6509 extrema of 147 stars are listed. The electronic version is available via http://ila.webjump.om. The observations for the analysis have been taken from the AFOEV and VSOLJ databases (with a duration up to 94 years) for the stars: AQ, EH, EK, RS, RU, RV, ST, TV, TY, TZ, UX, VX And; GY, PX, S, V, V844 Aql; V, Z Aqr; T Ari; AG, RS, S, UU, Z Aur; RV, RW, RX, RZ, U, V, WY Boo; T Cae; RR, RS, RY, S, ST, U Cam; RT Cap; PZ, SV, UX, V393, V465, WZ Cas; T, Y Cen; AR, RU, RW, RX, SS, TY, W Cep; T Cet; RS, RT, T, X Cnc; RR, RS, TT CrB; V, Y Cvn; AA, AF, AI, AV, AW, BC, RS, RU, RV, RW, RZ, TT, V460, W Cyg; EU, U Del; RS, RY, S, TX, UX, WZ Dra; SY, Z Eri; IS, NQ, RS, SW, TU, TV, Y Gem; DE, MZ, RR, ST, SX, UU, X Her; FF, RT, U, V, W, Y Hya; RS Lac; RY, SX Leo; RX, S Lep; U, W LMi; Y, EG, R, SZ Lyr; RV, SW, X Mon; V759 Oph; BQ, FX, GT, RT, W Ori; AF, AK, SV, TX Peg; AD, BU, DY, FZ, RS, RU, S, SU, SY, T, UZ, W, XX Per; R Pic; RT, RW, Z Psc; BM Sco; S Sct; FG Ser; X Sge; AB, TT, W, Y Tau; W Tri; RX, RY, RZ, ST,SV, V, Y, Z UMa; R, V UMi; RT, SS, SW Vir; RU Vul.

Chinarova, L. L.; Andronov, I. L.

2000-12-01

49

CNC water-jet machining and cutting center  

Microsoft Academic Search

Computer Numerical Control (CNC) water-jet machining was investigated to determine the potential applications and cost-effectiveness that would result by establishing this capability in the engineering shops of Allied-Signal Inc., Kansas City Division (KCD). Both conductive and nonconductive samples were machined at KCD on conventional machining equipment (a three-axis conversational programmed mill and a wire electrical discharge machine) and on two

D. C. Bartlett

1991-01-01

50

Real-time NURBS command generators for CNC servo controllers  

Microsoft Academic Search

This study proposes a real-time Non-Uniform Rational B-Spline (NURBS) motion command generator for computer numerical control (CNC) machines to achieve the goal of high-speed and highly accurate machining. Different numerical algorithms for implementing the NURBS motion command generator are compared on the basis of both the computation time and the precision of geometric representation. In addition, to reduce the computation

M.-Y. Cheng; M.-C. Tsai; J.-C. Kuo

2002-01-01

51

Retrofitment of a CNC machine for hybrid layered manufacturing  

Microsoft Academic Search

Subtractive manufacturing [computer numerical controlled (CNC) machining] has high quality geometric and material properties\\u000a but is slow, costly, and infeasible in some cases. On the contrary additive manufacturing (rapid prototyping) has total automation\\u000a but compromises quality. A hybrid layered manufacturing process presented in this study combines the best features of both\\u000a these approaches. It uses arc weld deposition for building

K. P. Karunakaran; S. Suryakumar; Vishal Pushpa; Sreenathbabu Akula

2009-01-01

52

VIRTUAL TRAINING ENVIRONMENT FOR A 3AXIS CNC MILLING MACHINE  

Microsoft Academic Search

A virtual training environment for a 3-axis CNC milling machine is presented. The key elements of the environment are: (a) textured 3D photo-realistic virtual models of the machines and lab; (b) machine simulator for the machines' controls and moving parts; (c) semi-empirical model of the machining operation; (d) hierarchical knowledge-base for process training; (e) unstructured knowledge-base for lecture delivery; (f)

Tamer M. Wasfy; Ayman M. Wasfy; Hazim El-Mounayri; Daniel Aw

53

Research on the thermal load of CNC milling machine  

NASA Astrophysics Data System (ADS)

Machine tool accuracy is the assurance of top-quality products in machining processes. In the all kinds of errors related to machine tools, thermal errors of machine tools' parts play an important role in machining accuracy and directly influence both the surface finish and the geometric shape of the finished workpiece. Therefore the objective of this work was to analyze the temperature field and thermal deformation in some parts of CNC machine tools. In this paper, the thermal boundary condition of main spindle and driving ball screw in CNC milling machine are discussed, some parameters in heat transfer process are calculated. Based on steady heat transfer process, the thermal analysis about spindle and ball screw is carried out under ANSYS environment, and their temperature fields are obtained when milling machine is working. Then the deformations of main spindle and ball screw are acquired by applying the thermal structure coupling element. Furthermore, in order to decrease main parts' deformations and improve the accuracy of CNC milling machine, some suggests are proposed.

Nie, Xue-Jun; Wu, Ping-Dong

2010-12-01

54

CNC-implemented fault diagnosis and web-based remote services  

Microsoft Academic Search

Recently, the conventional controller of machine-tool has been increasingly replaced by the PC-based open architecture controller,\\u000a which is independent of the CNC vendor and on which it is possible to implement user-defined application programs. This paper\\u000a proposes CNC-implemented fault diagnosis and web-based remote services for machine-tool with open architecture CNC. The faults\\u000a of CNC machine-tool are defined as the operational

Dong-Hoon Kim; Sun-Ho Kim; Kwang-Sik Koh

2005-01-01

55

Stars  

NASA Astrophysics Data System (ADS)

We will begin our study with a more or less superficial inspection of the "forest" of stars that we see in the skies. The first thing we notice is that, as sources of light, they are much weaker than the Sun. Second, their apparent colors vary; from a bluish-white in most of them to a reddish-yellow, which is rarer. There is also a third aspect, though it is not very obvious to the naked eye: most of the stars group themselves in small families of two, three or more members. A good example is the Alpha Centauri, the closest star to us, which, in fact, is a triple system of stars. Another is the group of 7 stars that make up the Pleiades, which will be discussed later on. In fact, almost half of the stars are double systems with only two members, called binary stars. Most of these double stars, though together, are separated by several astronomical units (one astronomical unit, AU, is the distance from Earth to the sun: see Chapter 1), and revolve around each other over periods of several years. And yet the revolutions of some binary stars, separated by much smaller distances, occur in only a few hours! These stars are so close to each other that they can share enveloping material. Often this exchange occurs in a somewhat violent manner. Local explosions may occur, expelling matter away from the system. In other binary systems, where one of the components is a very compact, dense star, companion material flows more calmly, making up a light disk around the compact star.

Capelato, Hugo Vicente

1999-01-01

56

Very Large Array Observations of H I in the Circumstellar Envelopes of Asymptotic Giant Branch Stars  

NASA Astrophysics Data System (ADS)

We have used the Very Large Array to search for neutral atomic hydrogen (H I) in the circumstellar envelopes of five asymptotic giant branch stars. We have detected H I 21 cm emission coincident in both position and velocity with the S-type semiregular variable star RS Cnc. The emission comprises a compact, slightly elongated feature centered on the star with a mean diameter of ~82" (1.5×1017 cm), plus an additional filament extending ~6' to the northwest. If this filament is associated with RS Cnc, it would imply that a portion of its mass loss is highly asymmetric. We estimate MHI~1.5×10-3 Msolar and a mass-loss rate M?~1.7×10-7 Msolar yr-1. Toward three other stars (IRC+10216, EP Aqr, R Cas) we have detected arcminute-scale H I emission features at velocities consistent with the circumstellar envelopes, but spatially offset from the stellar positions. Toward R Cas, the emission is weak but peaks at the stellar systemic velocity and overlaps with the location of its circumstellar dust shell and thus is probably related to the star. In the case of IRC+10216, we were unable to confirm the detection of H I in absorption against the cosmic background previously reported by Le Bertre & Gérard. However, we detect arcs of emission at projected distances of r~14'-18' (~2×1018 cm) to the northwest of the star. The large separation of the emission from the star is plausible, given its advanced evolutionary status, although it is unclear if the asymmetric distribution and complex velocity structure are consistent with a circumstellar origin. For EP Aqr, the detected H I emission comprises multiple clumps redward of the systemic velocity, but we are unable to determine unambiguously whether the emission arises from the circumstellar envelope or from interstellar clouds along the line of sight. Regardless of the adopted distance for the H I clumps, their inferred H I masses are at least an order of magnitude smaller than their individual gravitational binding masses. We did not detect any H I emission from our fifth target, R Aqr (a symbiotic binary), but measured a 1.4 GHz continuum flux density of 18.8+/-0.7 mJy. R Aqr is a previously known radio source, and the 1.4 GHz emission likely arises primarily from free-free emission from an ionized circumbinary envelope.

Matthews, Lynn D.; Reid, Mark J.

2007-05-01

57

CNC water-jet machining and cutting center  

NASA Astrophysics Data System (ADS)

Computer Numerical Control (CNC) water-jet machining was investigated to determine the potential applications and cost-effectiveness that would result by establishing this capability in the engineering shops of Allied-Signal Inc., Kansas City Division (KCD). Both conductive and nonconductive samples were machined at KCD on conventional machining equipment (a three-axis conversational programmed mill and a wire electrical discharge machine) and on two current-technology water-jet machines at outside vendors. These samples were then inspected, photographed, and evaluated. The current-technology water-jet machines were not as accurate as the conventional equipment. The resolution of the water-jet equipment was only +/- 0.005 inch, as compared to +/- 0.0002 inch for the conventional equipment. The principal use for CNC water-jet machining would be as follows: Contouring to near finished shape those items made from 300 and 400 series stainless steels, titanium, Inconel, aluminum, glass, or any material whose fabrication tolerance is less than the machine resolution of +/- 0.005 inch; and contouring to finished shape those items made from Kevlar, rubber, fiberglass, foam, aluminum, or any material whose fabrication specifications allow the use of a machine with +/- 0.005 inch tolerance. Additional applications are possible because there is minimal force generated on the material being cut and because the water-jet cuts without generating dust.

Bartlett, D. C.

1991-09-01

58

Prepolishing on a CNC platform with bound abrasive contour tools  

NASA Astrophysics Data System (ADS)

Deterministic microgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-5?m peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an Optipro CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Schoeffler, Adrienne E.; Gregg, Leslie L.; Schoen, John M.; Fess, Edward M.; Hakiel, Michael; Jacobs, Stephen D.

2003-05-01

59

Finishing of EUV photomask substrates by CNC precessed bonnet polisher  

NASA Astrophysics Data System (ADS)

The progressive transition from Excimer to EUV lithography is driving a need for flatter and smoother photomasks. It is proving difficult to meet this next generation specification with the conventional chemical mechanical polishing technology commonly used for finishing photomasks. This paper reports on the application of sub-aperture CNC precessed bonnet polishing technology to the corrective finishing of photomask substrates for EUV lithography. Fullfactorial analysis was used to identify process parameters capable of delivering 0.5 nm rms surface roughness whilst achieving removal rates above 0.1 mm3/min. Experimental results show that masks pre-polished to 300~600 nm P-V flatness by CMP can then be improved down to 50~100 nm P-V flatness using the automated technology described in this paper. A series of edge polishing experiments also hints at the possibility of increasing the quality area beyond the 5 mm defined in the official EUV photomask specification.

Beaucamp, Anthony T. H.; Namba, Yoshiharu; Charlton, Phillip; Freeman, Richard R.

2013-09-01

60

Cellulose nanocrystals (CNC) as carriers for a spirooxazine dye and its effect on photochromic efficiency.  

PubMed

Nanocrystalline cellulose (CNC) as a renewable/sustainable material, has received much attention. Herein we studied CNC as carriers for a hydrophobic spirooxazine (SO)-based dye, 1,3-dihydro-1,3,3-trimethylspiro[2H-indole-2,3'-[3H]naphtha[2,1-b][1,4]oxazine], which may have potential applications in reversible memory photo-devices, textiles, photo-sensitive paper coatings, and inkjet printing inks. Due to the high cost and water-insolubility of this dye, it is desirable to improve its coloration efficiency and water-dispersibility. The experimental approach was to use CNC as carriers for the SO dye, thus obtaining a stable photochromic dye in aqueous systems. Transmission electron microscope (TEM) observation confirmed that the SO dye adsorbed on the surface of the CNC, which functioned as carriers for the photochromic dye. An impregnation process was adopted to anchor the dye onto cellulosic paper. It was found that the use of CNC resulted in a significant improvement in the SO coloration efficiency. The color stability and fatigue resistance were also studied. The use of CNC as carriers for a hydrophobic compound, its enhancement of associated properties, and its subsequent application were demonstrated. PMID:25037370

Sun, Bo; Hou, Qingxi; He, Zhibin; Liu, Zehua; Ni, Yonghao

2014-10-13

61

Continuous tone printing in silicone from CNC milled matrices  

NASA Astrophysics Data System (ADS)

Current research at the Centre for Fine Print Research (CFPR) at the University of the West of England, Bristol, is exploring the potential of creating coloured pictorial imagery from a continuous tone relief surface. To create the printing matrices the research team have been using CNC milled images where the height of the relief image is dictated by creating a tone curve and then milling this curve into a series of relief blocks from which the image is cast in a silicone ink. A translucent image is cast from each of the colour matrices and each colour is assembled - one on top of another - resulting is a colour continuous tone print, where colour tone is created by physical depth of colour. This process is a contemporary method of continuous tone colour printing based upon the Nineteenth Century black and white printing process of Woodburytype as developed by Walter Bentley Woodbury in 1865. Woodburytype is the only true continuous tone printing process invented, and although its delicate and subtle surfaces surpassed all other printing methods at the time. The process died out in the late nineteenth century as more expedient and cost effective methods of printing prevailed. New research at CFPR builds upon previous research that combines 19th Century Photomechanical techniques with digital technology to reappraise the potential of these processes.

Hoskins, S.; McCallion, P.

2014-02-01

62

An optimisation approach to the contour error control of CNC machine tools using genetic algorithms  

Microsoft Academic Search

A contour control strategy has been studied in this paper to improve the contour error of CNC machine tools. First, a single axis controller is analysed and then a velocity feedforward controller is added in the velocity loop. To further reduce the contour error, a cross-coupled controller is adopted and an algorithm for an on-line estimation of the contour error

Y. S. Tarng; H. Y. Chuang; W. T. Hsu

1997-01-01

63

Reverse engineering: Autonomous digitization of free-formed surfaces on a CNC coordinate measuring machine  

Microsoft Academic Search

We present an automatic algorithm of digitization on a CNC coordinate measuring machine for reverse engineering of an unknown free-formed surface. This algorithm supervises the movement of a contact type ball-tip probe in an autonomous manner in that the surface is discretely sampled to be fitted by a polyhedron surface model of triangular plane patches. Vertex points of the polyhedron

C.-K. Song; S.-W. Kim

1997-01-01

64

Development of a low cost Touch Trigger Probe for CNC Lathes  

Microsoft Academic Search

The use of Touch Trigger Probes for CNC Machine Tools has become a world standard, mainly due to the reduction of machine setup time and the ability to promote workpiece accuracy on-machine measurements. However, some barriers still need to be transposed, like the measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about

Marcelo Del Guerra; Reginaldo Teixeira Coelho

2006-01-01

65

RS-84 Engine  

NASA Technical Reports Server (NTRS)

The RS-84 is the first reusable hydrocarbon staged combustion liquid rocket engine. This engine is being developed to meet NASA s crew safety goals with a highly reliable and low cost main engine as a part of the NASA Space Launch Initiative program for the next generation reusable launch system. The NASA-MSFC and Rocketdyne team brings over 50 years of successful rocket engine development experience to meet the challenges of this new program. This team s extensive design database has been anchored with almost five decades of hydrocarbon rocket engine development and flight operations experience including Delta, Atlas, and Saturn vehicles and nearly three decades of successfully operating the world s only reusable pump-fed rocket engine, the Space Shuttle Main Engine. The team also fully benefits from the proven and experienced engineering staffs that recently completed the successful MC-1 FASTRAC , XRS-2200, and RS-68 engine development programs and the ongoing IPD and RS-76 technology development. Advances in integrated parametric design and analysis tools, advanced materials knowledge base, and state-of-the-art fabrication processes anchored and refined during the recent engine development programs are already being used by the team to design this engine.

Stegman, E.

2003-01-01

66

Infrared high angular resolution measurements of stellar sources. VI. Accurate angular diameters of X Cnc, U Ori and Eta Gem  

NASA Astrophysics Data System (ADS)

We present the results of near-IR lunar occultation measurements of three well-known, large angular diameter, cool giant stars, namely X Cnc (CII), U Ori (M8III) and eta Gem (M3III). Their 2.2 mu m angular diameters, derived under the assumption of a uniform circular disk, are 8.26+/-0.04, 15.14+/-0.05 and 12.57+/-0.04 milliarcsec, respectively. In the case of U Ori, we find a significant deviation of the brightness profile from circular symmetry, as well as a faint signature of extended emission. The asymmetry of the brightness profile cannot be explained by scintillation effects in the lunar occultation lightcurve, and could have contributed to the important differences in previous determinations of the angular diameter of U Ori in the near-IR. Also in the case of eta Gem, significant differences exist among the available angular diameter determinations. Based on observations collected at TIRGO (Gornergrat, Switzerland). TIRGO is operated by CNR - CAISMI Arcetri, Italy.

Richichi, A.; Calamai, G.

2003-02-01

67

Radio emission of cataclysmic variable stars  

NASA Technical Reports Server (NTRS)

Eight cataclysmic variable stars were observed at 6 cm wavelength using the Very Large Array (VLA). The objects were: CN-Ori, SS-Aur, YZ-Cnc, SU-Uma, Z-Cam, V603-Aql, EM-Cyg, and RZ-Sge. Most of these objects were in optical high stage, but none were detected beyond flux limits between 0.1 and 0.3 mJy.

Fuerst, E.; Benz, A.; Hirth, W.; Geffert, M.; Kiplinger, A.

1986-01-01

68

RS Landers: Lunar lander  

NASA Technical Reports Server (NTRS)

The future of the U.S. space program outlined by President Bush calls for a permanently manned lunar base. A payload delivery system will be required to support the buildup and operation of that lunar base. In response to this goal, RS Landers developed a conceptual design of a self-unloading, unmanned, reusable lunar lander. The lander will deliver a 7000-kg payload, with the same dimensions as a space station logistics module, from low lunar orbit (LLO) to any location on the surface of the Moon.

1991-01-01

69

RS232 Led Board  

Microsoft Academic Search

This article demonstrates how to develop a Microchip PIC16F84 based device\\u000athat supports RS-232 interface with PC. Circuit (LED Board) design and software\\u000adevelopment will be discussed. PicBasic Pro Compiler from microEngineering\\u000aLabs, Inc. is used for PIC programming. Development of LED Board Control\\u000aConsole using C\\/C++ is also briefly discussed. The project requires basic work\\u000aexperience with Microchip PICs,

Vladimir Tskhvaradze

2007-01-01

70

RS Ophiuchi: Connections to the Symbiotic Variable AG Dra  

Microsoft Academic Search

AG Dra is a symbiotic variable bearing a number of similarities to the suspected emitting components in RS Oph among which are an irradiated red giant mass donor, metal poor, similarly long orbital periods, a hot accreting white dwarf irradiating an optically thick bright accretion disk. Both objects have been counted among the yellow symbiotic stars (Smith et al. 1996).

E. M. Sion; J. Miko

2008-01-01

71

Pseudo-random tool paths for CNC sub-aperture polishing and other applications.  

PubMed

In this paper we first contrast classical and CNC polishing techniques in regard to the repetitiveness of the machine motions. We then present a pseudo-random tool path for use with CNC sub-aperture polishing techniques and report polishing results from equivalent random and raster tool-paths. The random tool-path used - the unicursal random tool-path - employs a random seed to generate a pattern which never crosses itself. Because of this property, this tool-path is directly compatible with dwell time maps for corrective polishing. The tool-path can be used to polish any continuous area of any boundary shape, including surfaces with interior perforations. PMID:19581985

Dunn, Christina R; Walker, David D

2008-11-10

72

Real-time PH curve CNC interpolators for high speed cornering  

Microsoft Academic Search

In this paper, real-time Pythagorean hodograph (P-H) curve CNC interpolators are used for high speed corner machining. There\\u000a are large contouring errors around sharp corners when low-bandwidth servo controllers (such as P-PI control) are used. In\\u000a order to decrease the amount of the cornering errors, an improved interpolation method is proposed. The first deceleration\\u000a phase of motion and the over-corner

Javad Jahanpour; Behnam Moetakef Imani

2008-01-01

73

A new method for defining the measurement-uncertainty model of CNC laser-triangulation scanner  

Microsoft Academic Search

This article examines the measurement uncertainty in terms of the incident angle, the object colour and the measurement distance\\u000a for a Computer Numerical Control (CNC) laser-scanning process. It describes a new method for predicting the measurement uncertainty\\u000a that simultaneously considers all three parameters. A set of measurements with different values for these parameters was made\\u000a in order to describe the

Nikola Vukašinovi?; Drago Bra?un; Janez Možina; Jože Duhovnik

74

The vibration behavior of impeller blades in the five-axis CNC flank milling process  

Microsoft Academic Search

Today, in most cases, impellers of centrifugal compressors are produced by flank milling on five-axis CNC milling machines.\\u000a The complex three-dimensional geometry of the very thin blades consists of ruled surfaces. The flank milling process allows\\u000a a fast production of the impellers and the surface of the blades is of high quality. The limited strength of the very thin\\u000a blades

Kawin Sonthipermpoon; E. Bohez; H. Hasemann; M. Rautenberg

2010-01-01

75

Infrared wireless system for high speed RS232\\/RS423\\/RS422 communications  

Microsoft Academic Search

The design and implementation of a RS-232\\/RS-423\\/RS-422 (115200-Bd) modem which uses a wireless infrared link are discussed. This kind of system presents some advantages over the conventional cable systems or radio systems. When IREDs are used, the radiation is negligible for the users and harmless. These systems can be used to link two buildings (point-to-point) or to avoid cables inhouse

M. J. Betancor; J. Martin-Bernardo; A. Santamaria; V. M. Melian; F. J. Lopez-Hernandez

1992-01-01

76

Photoelectric UBV photometry of variable stars observed during the years 1961-1999  

NASA Astrophysics Data System (ADS)

Photoelectric UBV photometry of the variable stars V 636 Cas, alpha UMi, V 440 Per, zeta Gem, UU Cnc, TYC2-880-515-1, V 473 Lyr, chi Cyg, V 1794 Cyg, DT Cyg, V 1334 Cyg, V 532 Cyg, pi Aqr, and DY Peg is reported.

Oja, T.

2011-02-01

77

The large outbursts studied by small telescopes - the case of RS Oph  

NASA Astrophysics Data System (ADS)

Cataclysmic variables (CVs) are one of the dominant part in astronomical research. Small telescopes are widely used to search for the sudden brightening of such stars. We present our experience with observations of the RS Ophiuchi (RS Oph) and analyses of the light curves. RS Oph is a binary system with 6 recorded outbursts classified as a recurrent nova (RN). We used the telescopes of AI SAS to measure the brightness of RS Oph after its last outburst occurred on February 12, 2006. The new observations indicate the ongoing mass transfer. % and the estimation of the mass transfer rate allow to make a prediction of the %next outburst of this RN.

Kundra, E.; Hric, L.

2014-03-01

78

Setup for Triggering Force Testing of Touch Probes for CNC Machine Tools and CMMs  

NASA Astrophysics Data System (ADS)

Touch-trigger probes are commonly used both in coordinate measuring machines (CMM) and in computer numerical control (CNC) machine tools. In both cases accuracy of measurement of the overall system and probing unit are closely interrelated. Key parameters of the probes are repeatability and pre-travel variation dependent on adjustable stylus force. To enable testing of the triggering force of the probes, the new setup was developed. The principle of the method and set-up is presented and its validity is experimentally confirmed.

Wozniak, A.; Byszewski, M.; Jankowski, M.

2013-01-01

79

H-alpha spectroscopy of active-chromosphere stars. I - Six G-K giants  

Microsoft Academic Search

Initial results from an ongoing program to monitor the long-term behavior of the H-alpha line in active-chromosphere stars are presented. The performance of a Reticon system used to obtain H-alpha spectra with 0.3 A resolution and 100:1 SNR is discussed, and results for six G-K giants are presented. The rapidly rotating G0 III stars 31 Com and 35 Cnc show

Bernard W. Bopp; Robert C. Dempsey; Steven Maniak

1988-01-01

80

Rotational modulation and flares on RS CVn and BY Dra-type stars. I - Photometry and spot models for BY Dra, AU Mic, AR Lac, II Peg and V 711 Tau (= HR 1099)  

NASA Technical Reports Server (NTRS)

Multicolor wide-band photometry of five active stars is presented. The observations were carried out at several places before, during and after the period of IUE observations for the purpose of determining the location, sizes, and evolution of photospheric spots at the time when chromospheric, transition region, and coronal activity data were obtained from UV and radio observations. II Peg, BY Dra, and AU Mic show fairly stable quasi-sinusoidal light curves, while AR Lac and V 711 Tau show double-peaked light curves. For V 711 Tau, a remarkable evolution of the spotted area extent and/or longitude distribution is found. Small, but definite color variations that are consistent with the cool spot hypothesis have also been detected for BY Dra, II Peg and V 711 Tau.

Rodono, M.; Cutispoto, G.; Pazzani, V.; Catalano, S.; Byrne, P. B.

1986-01-01

81

Non-contact automatic measurement of free-form surface profiles on CNC machines  

NASA Astrophysics Data System (ADS)

This paper describes the work to develop a non-contact type automatic measurement system for any free-form surfaces on a CNC machine tool or a coordinate measuring machine (CMM) and its CAD/CAM integration. A laser probe made by Keyence Co. model LC-2220 was integrated into the CNC machine as the non-contact sensor. A measurement software has been developed for automatic surface tracing of any free-form profile. Data transfer to any commercially available CAD/CAM system for reverse engineering is also available via proper DXF file. Extensive calibration work has been carried out on the systematic accuracy of the laser probe with respect to the color material surface slope and edge detection of the workpiece by the use of a HP5528 laser interferometer system. Having employed the surface painting technique the shape error of the copied object relative to its master piece was found within 30 micrometers which is deemed adequate enough to the mold industry.

Fan, Kuang-Chao; Wen, Kuang-Pu

1993-09-01

82

AT Cnc: A SECOND DWARF NOVA WITH A CLASSICAL NOVA SHELL  

SciTech Connect

We are systematically surveying all known and suspected Z Cam-type dwarf novae for classical nova shells. This survey is motivated by the discovery of the largest known classical nova shell, which surrounds the archetypal dwarf nova Z Camelopardalis. The Z Cam shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts, in accord with the hibernation scenario of cataclysmic binaries. Here we report the detection of a fragmented 'shell', 3 arcmin in diameter, surrounding the dwarf nova AT Cancri. This second discovery demonstrates that nova shells surrounding Z Cam-type dwarf novae cannot be very rare. The shell geometry is suggestive of bipolar, conical ejection seen nearly pole-on. A spectrum of the brightest AT Cnc shell knot is similar to that of the ejecta of the classical nova GK Per, and of Z Cam, dominated by [N II] emission. Galaxy Evolution Explorer FUV imagery reveals a similar-sized, FUV-emitting shell. We determine a distance of 460 pc to AT Cnc, and an upper limit to its ejecta mass of {approx}5 Multiplication-Sign 10{sup -5} M {sub Sun }, typical of classical novae.

Shara, Michael M.; Mizusawa, Trisha; Zurek, David [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192 (United States); Wehinger, Peter [Steward Observatory, the University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Martin, Christopher D.; Neill, James D.; Forster, Karl [Department of Physics, Math and Astronomy, California Institute of Technology, 1200 East California Boulevard, Mail Code 405-47, Pasadena, CA 91125 (United States); Seibert, Mark [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2012-10-20

83

CNC machine tool's wear diagnostic and prognostic by using dynamic Bayesian networks  

NASA Astrophysics Data System (ADS)

The failure of critical components in industrial systems may have negative consequences on the availability, the productivity, the security and the environment. To avoid such situations, the health condition of the physical system, and particularly of its critical components, can be constantly assessed by using the monitoring data to perform on-line system diagnostics and prognostics. The present paper is a contribution on the assessment of the health condition of a computer numerical control (CNC) tool machine and the estimation of its remaining useful life (RUL). The proposed method relies on two main phases: an off-line phase and an on-line phase. During the first phase, the raw data provided by the sensors are processed to extract reliable features. These latter are used as inputs of learning algorithms in order to generate the models that represent the wear's behavior of the cutting tool. Then, in the second phase, which is an assessment one, the constructed models are exploited to identify the tool's current health state, predict its RUL and the associated confidence bounds. The proposed method is applied on a benchmark of condition monitoring data gathered during several cuts of a CNC tool. Simulation results are obtained and discussed at the end of the paper.

Tobon-Mejia, D. A.; Medjaher, K.; Zerhouni, N.

2012-04-01

84

The Use of Patent Data for Technological Forecasting: The Diffusion of CNC-Technology in the Machine Tool Industry  

Microsoft Academic Search

In the 1980s, a dramatic change in the competitive structure of the machine tool industry through the development and implementation of CNC-technology occurred. For the individual company, the timely anticipation and forecast of these technological challenges has been of vital importance in order to incorporate these technological changes into its strategic planning process. This paper assesses the suitability of patent

H. Ernst

1997-01-01

85

MM Herculis - An eclipsing binary of the RS CVn  

NASA Technical Reports Server (NTRS)

V, B and U differential photoelectric photometry has been obtained for the RS Canum Venaticorum-class eclipsing binary star MM Her, with the light outside the eclipse being Fourier-analyzed to study wave migration and amplitude. These, together with the mean light level of the system, have been monitored from 1976 through 1980. Observations within the eclipse have revealed eclipses to be partial, rather than total as previously thought. The geometric elements of the presently rectified light curve are forced on the pre-1980 light curves and found to be compatible. With these elements, and previously obtained double line radial velocity curves, new absolute dimensions of 1.18 solar masses and 1.58 solar radii are calculated for the hotter star and 1.27 solar masses and 2.83 solar radii for the cooler star. The plotting of color indices on the color-color curve indicates G2V and K2IV spectral types.

Sowell, J. R.; Hall, D. S.; Henry, G. W.; Burke, E. W., Jr.; Milone, E. F.

1983-01-01

86

Beam shaping optics for YAG laser by using a CNC lathe  

NASA Astrophysics Data System (ADS)

A method for a beam shaping optics is proposed to convert a laser beam profile into required intensity distribution. A beam shaper with aspherical surface is calculated by Snell's law converted from measured irradiate beam profile to required profile. An acrylic resin is cut by a ball type grinding wheel consisted on diamond powder and polished by a cone type felt buff with alumina ceramics powder. A CNC lathe is used to control these tools position. A shaper with 4mm of thickness works to convert multi-mode beam profile with 13mm of diameter into a flat top cylinder with 1mm of diameter. Its working distance is 60mm. Its transmittance is over 98%.It suceed to generate uniform melting mark of 0.6mm diameter on the steel target by YAG laser process.

Kuwano, Ryoichi; Tokunaga, Tsuyoshi; Kataoka, Yoshihiro; Otani, Yukitoshi; Miyazaki, Toshiyuki

2003-10-01

87

Commissioning of the first Precessions 1.2-m CNC polishing machines for large optics  

NASA Astrophysics Data System (ADS)

This paper reports on the commissioning of the first of Zeeko's "IRP1200" 1.2m capacity 7-axis automated CNC polishing machines. These combo machines now support five different removal regimes, which are described. The machines differ substantially from Zeeko's more familiar 200mm machines on which we have focused before, in terms of overall architecture and detailed design. Large and small optics place different demands on part-fixturing, tooling, machine speeds and accelerations, metrology, slurry-handling, part-loading and access etc. These have had a profound effect on the development-path from 200 to 1.2m machines. Moreover, an advance in the kinematic design has extended the allowable range of surface slope-angles from typically 30° up to a hemisphere. The paper presents results from the pass-off trials, the first fluid-jet experiment, and the development of tooling to address a requirement to smooth a part with a local defect.

Walker, D. D.; Beaucamp, A. T. H.; Doubrovski, V.; Dunn, C.; Evans, R.; Freeman, R.; McCavana, G.; Morton, R.; Riley, D.; Simms, J.; Yu, G.; Wei, X.

2006-08-01

88

Concurrent Collections (CnC): A new approach to parallel programming  

SciTech Connect

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

None

2010-05-07

89

Concurrent Collections (CnC): A new approach to parallel programming  

ScienceCinema

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment?s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

None

2011-10-06

90

Frequent Phosphodiesterase 11A Gene (PDE11A) Defects in Patients with Carney Complex (CNC) Caused by PRKAR1A Mutations: PDE11A May Contribute to Adrenal and Testicular Tumors in CNC as a Modifier of the Phenotype  

PubMed Central

Background: Carney complex (CNC) is an autosomal dominant multiple neoplasia, caused mostly by inactivating mutations of the regulatory subunit 1A of the protein kinase A (PRKAR1A). Primary pigmented nodular adrenocortical disease (PPNAD) is the most frequent endocrine manifestation of CNC with a great inter-individual variability. Germline, protein-truncating mutations of phosphodiesterase type 11A (PDE11A) have been described to predispose to a variety of endocrine tumors, including adrenal and testicular tumors. Objectives: Our objective was to investigate the role of PDE11A as a possible gene modifier of the phenotype in a series of 150 patients with CNC. Results: A higher frequency of PDE11A variants in patients with CNC compared with healthy controls was found (25.3 vs. 6.8%, P < 0.0001). Among CNC patients, those with PPNAD were significantly more frequently carriers of PDE11A variants compared with patients without PPNAD (30.8 vs. 13%, P = 0.025). Furthermore, men with PPNAD were significantly more frequently carriers of PDE11A sequence variants (40.7%) than women with PPNAD (27.3%) (P < 0.001). A higher frequency of PDE11A sequence variants was also found in patients with large-cell calcifying Sertoli cell tumors (LCCSCT) compared with those without LCCSCT (50 vs. 10%, P = 0.0056). PDE11A variants were significantly associated with the copresence of PPNAD and LCCSCT in men: 81 vs. 20%, P < 0.004). The simultaneous inactivation of PRKAR1A and PDE11A by small inhibitory RNA led to an increase in cAMP-regulatory element-mediated transcriptional activity under basal conditions and after stimulation by forskolin. Conclusions: We demonstrate, in a large cohort of CNC patients, a high frequency of PDE11A variants, suggesting that PDE11A is a genetic modifying factor for the development of testicular and adrenal tumors in patients with germline PRKAR1A mutation.

Libe, Rossella; Horvath, Anelia; Vezzosi, Delphine; Fratticci, Amato; Coste, Joel; Perlemoine, Karine; Ragazzon, Bruno; Guillaud-Bataille, Marine; Groussin, Lionel; Clauser, Eric; Raffin-Sanson, Marie-Laure; Siegel, Jennifer; Moran, Jason; Drori-Herishanu, Limor; Faucz, Fabio Rueda; Lodish, Maya; Nesterova, Maria; Bertagna, Xavier; Bertherat, Jerome; Stratakis, Constantine A.

2011-01-01

91

The long-period Galactic Cepheid RS Puppis. I. A geometric distance from its light echoes  

NASA Astrophysics Data System (ADS)

Context: The bright southern Cepheid RS Pup is surrounded by a circumstellar nebula reflecting the light from the central star. The propagation of the light variations from the Cepheid inside the dusty nebula creates spectacular light echoes that can be observed up to large distances from the star itself. This phenomenon is currently unique in this class of stars. Aims: For this relatively distant star, the trigonometric parallax available from Hipparcos has a low accuracy. A careful observation of the light echoes has the potential to provide a very accurate, geometric distance to RS Pup. Methods: We obtained a series of CCD images of RS Pup with the NTT/EMMI instrument covering the variation period of the star (P = 41.4 d), allowing us to track the progression of the light wavefronts over the nebular features surrounding the star. We measured precisely the phase lag of the photometric variation in several regions of the circumstellar nebula. Results: From our phase lag measurements, we derive a geometric distance of 1992 ± 28 pc to RS Pup. This distance is affected by a total uncertainty of 1.4%, and corresponds to a parallax of ? = 0.502 ± 0.007 mas and a distance modulus of ? = 11.50 ± 0.03. Conclusions: The geometric distance we derive is by far the most accurate to a Cepheid, and among the most accurate to any star. RS Pup appears both as somewhat neglected and particularly promising to investigate the mass-loss history of Cepheids. Thanks to its highly accurate distance, it is also bound to become an important luminosity fiducial for the long period part of the period-luminosity diagram.

Kervella, P.; Mérand, A.; Szabados, L.; Fouqué, P.; Bersier, D.; Pompei, E.; Perrin, G.

2008-03-01

92

RS3PE-Syndrom  

Microsoft Academic Search

Summary   The RS3PE syndrome (Remitting Seronegative Symmetrical Synovitis with Pitting Edema) is a manifestation of rheumatoid arthritis in\\u000a the elderly with a good prognosis. It usually presents as an acute, symmetric polysynovitis with edema of the dorsum of the\\u000a hands and feet. Anti-inflammatory treatment with corticosteroids leads to prompt improvement. We describe the case of an 81\\u000a year old man

S. Segerer; P. Dietz-Laukemann; M. Schattenkirchner

1999-01-01

93

(5RS,10SR,15RS)-Trimethyl-truxene1  

PubMed Central

The title mol­ecule, C30H24, was prepared as a possible precursor to buckminsterfullerene cages. The two enanti­omers adopt the anti configuration, with one S/R and two R/S methyl groups, one anti to the other two. The truxene framework is slightly non-planar: with respect to the central six-ring mean plane, the three methyl C atoms are 1.377?(3), ?1.475?(3) and 1.515?(3)?Å distant, whereas the respective proximate peripheral six-ring mean planes make dihedral angles of 6.27?(6), 3.45?(7) and ?7.37?(7)°.

Thomas, Kandace R.; Dhar, Raj K.; Fronczek, Frank R.; Watkins, Steven F.

2011-01-01

94

Tidal Dissipation and Eccentricity Pumping: Implications for the Depth of the Secondary Eclipse of 55 Cnc e  

NASA Astrophysics Data System (ADS)

We use the super-Earth 55 Cnc e (Fischer et al. 2008) as a case-study to address an observable effect of tidal heating. This transiting short-period planet belongs to a compact multiple system with massive planets. We investigate whether planet-planet interactions can force the eccentricity of this planet to a level that would affect the eclipse depth observed with Spitzer.

Bolmont, E.; Selsis, F.; Raymond, S. N.; Leconte, J.; Hersant, F.; Maurin, A.-S.; Pericaud, J.

2014-01-01

95

A low glitch 12-bit current-steering CMOS DAC for CNC systems  

NASA Astrophysics Data System (ADS)

A 12-bit, 100-MHz CMOS current-steering D/A converter for CNC (computer number control) systems is presented. To reduce the glitch and increase the SFDR (spurious-free dynamic range), a low crosspoint switch driver and a special dummy switch are applied. In addition, a 4-5-3 segmental structure is used to optimize the performance and layout area. After improvement, the biggest glitch energy decreased from 6.7 pVs to 1.7 pVs, the INL decreased from 2 LSB to 0.8 LSB, the SFDR is 78 dB at a 100-MSPS clock rate and 1 MHz output frequency. This DAC can deliver up to 20.8 mA full-scale current into a 50 ? load. The power when operating at full-scale current is 163 mW. The layout area is 1.8 × 1.8 mm2 in a standard 0.35-?m CMOS technology.

Jianming, Lei; Hanshu, Gui; Beiwen, Hu

2013-02-01

96

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

NASA Astrophysics Data System (ADS)

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

2005-02-01

97

Automated optical fabrication: first results from the new Precessions 1.2m CNC polishing machine  

NASA Astrophysics Data System (ADS)

The requirements of space and defence optical systems and ground-based astronomy (especially extremely large telescopes) are providing optical fabricators with new challenges. These challenges particularly concern process speed, determinism and automation, and tighter tolerances on surface form and texture. Moreover, there is a growing demand for complex off-axis and 'freeform' surfaces and for larger components of the ~1m scale. With this in view, we first report on form-correction on a smaller analogue of the IRP1200: an IRP400 in service in industry. We then report on the design, commissioning and preliminary process-development results from the first of the scaled-up 1.2m capacity CNC polishing machine from Zeeko, Ltd. This machine delivers the 'Classic' bonnet-based process, together with two new processes: fluid-jet polishing and the hybrid soft-grinding/polishing process called 'Zeeko-Grolish.' We indicate how this trio of processes running on the same machine platform with unified software can provide an unprecedented dynamic range in both volumetric removal rate and removal spot-size. This leads into a discussion of how these processes may be brought to bear on optimal control of texture and form. Preliminary performance of the 1.2m machine is illustrated with results on both axially-symmetric and more complex removal regimes. The paper concludes with an overview of the relevance of the technology to efficient production of instrumentation-optics, space optics and segmented telescope mirrors.

Walker, D. D.; Beaucamp, A. T. H.; Doubrovski, V.; Dunn, C.; Evans, R.; Freeman, R.; Kelchner, J.; McCavana, G.; Morton, R.; Riley, D.; Simms, J.; Yu, G.; Wei, X.

2006-06-01

98

Interleukin-6-receptor polymorphisms rs12083537, rs2228145, and rs4329505 as predictors of response to tocilizumab in rheumatoid arthritis.  

PubMed

Tocilizumab (TCZ), a monoclonal antibody targeting the human interleukin-6-receptor (IL-6R), is indicated for the treatment of rheumatoid arthritis (RA). We examined whether three IL6R single-nucleotide polymorphisms rs12083537, rs2228145 (formerly rs8192284), and rs4329505 with previously reported functional effects were associated with clinical response to TCZ in a retrospective study cohort consisting of 79 RA patients. Three months after initiation of TCZ therapy, changes in swollen joint count (SJC) and, subordinately, tender joint count (TJC), serum-CRP, DAS28-CRP, and EULAR-response were tested for association with the IL6R-haplotype or genotype. The major allele (A) of rs12083537 and the minor allele (C) of rs4329505 were associated with a poor SJC response (P=0.02 and 0.02, respectively). Moreover, the AAC-haplotype (for rs12083537, rs2228145, and rs4329505, respectively) was associated with a poor SJC response (P=0.00004) and, with borderline significance, EULAR-response (P=0.05). These data suggest that genetic variation in IL6R may aid in predicting TCZ therapy outcome in RA patients. PMID:24978393

Enevold, Christian; Baslund, Bo; Linde, Louise; Josephsen, Norah L; Tarp, Ulrik; Lindegaard, Hanne; Jacobsen, Søren; Nielsen, Claus H

2014-08-01

99

Spectroscopy and photometry of binary stars in old open clusters  

NASA Astrophysics Data System (ADS)

We have performed a spectroscopic and photometric study of six contact binary stars in four old open clusters, M67, Praesepe, NGC 6791 and NGC 752, in order to evaluate their suitability for measuring the distance to their respective clusters. The technique being tested uses the cosine Fourier coefficients of the light curves of the binary stars, and the mass ratios obtained spectroscopically, to provide distances to the binaries. The contact binary TX Cnc was used to obtain the distance to Praesepe, which we find to be (V-MV) o = 6.30 ± 0.08, which is in good agreement with the values of V-MV = 6.20 6.35 found in color-magnitude diagram (CMD) studies. We obtained a distance modulus of (V-MV) o = 12.71 ± 0.44 for V7 in NGC 6791, the oldest cluster in our survey. This agrees within ˜1? the values of 13.3 ? ( V-MV) ? 13.42 obtained by isochrone fitting of the cluster CMD. Our spectroscopic study of QX And in NGC 752 provided a distance modulus of V-MV = 8.30 ± 0.07 for this cluster. This compares to a value of V-MV = 7.9 ± 0.1 obtained by Milone et al. (1995) using the same star, but is in good agreement with V-MV = 8.25 ± 0.10 obtained by Daniel et al. (1994) from the CMD. The distances to the clusters as determined from the contact binaries using our procedure do not seem to give systematically smaller or larger distances as compared to CMD fitting. However, we have measured the distances to only three clusters, and only one object per cluster, and so establishing any systematic differences may require a larger survey. For the four clusters in this work, our new distance moduli and those of CMD fitting are in good agreement in all cases. We conclude that contact binaries could very well provide good distance indicators to their parent clusters. Surveys such as the Canada-France-Hawaii Legacy Survey will discover many contact binaries for which full least-squares orbital solutions will not be possible due to the large volume of data. The technique developed here should provide good preliminary orbital parameters for such binary star systems. The cosine Fourier coefficients of the light curve of EV Cnc in M67 lie off the grid of values for contact binaries, which leads us to speculate that this star may be an Algol system, rather than a contact binary. EV Cnc also exhibits the O'Connell effect, which in this case may be caused by a hot spot created on the surface of the primary by the impact of a gas stream. Consistent with this idea is the fact that EV Cnc's velocity curve exhibits blue-shifted velocities near the secondary eclipse, which may be due to a gas stream which transfers mass from the secondary to the primary in a semi-detached system. As a result, EV Cnc in M67 was found to be unsuitable for distance determinations. Our photometry of the contact binary AH Cnc in M67 indicates a possible new feature in its light curve. After secondary minimum, this star exhibits a 0.1 magnitude increase in brightness over a short time scale. Such a phenomenon has not previously been reported in any of the W UMa stars.

Blake, Ronald Melvin

100

A Three Dimensional Picture of RS CVN Stellar Atmospheres  

NASA Astrophysics Data System (ADS)

The ROSAT all-sky survey provides a unique opportunity to study an RS CVn system simultaneously at x-ray, EUV, UV, optical, and radio wavelengths at many phases throughout an orbital period. ROSAT can detect the x-ray flux of each candidate system during each 30 second viewing 16 times per day for at least 2 days. We request a block of 7 IUE shifts to obtain NEAR SIMULTANEOUS emission line fluxes (SWP-LO) and Mg IT line profiles (LWP-HI), and we will obtain contemporaneous optical photometry and spectroscopy and VLA radio fluxes (3.6, 6, and 20 cm). one objective of this PROPOSAL is to obtain the FIRST 3-D MODEL OF THE INHOMOGENEOUS PHOTOSPHERE, CHROMOSPHERE, AND CORONA OF A STAR OTHER THAN THE SUN. We will use optical photometry and spectroscopy to map the spotted photospheres of each star, and the Mg II line profiles to DOPPLERIMAGE their chromospheres, to determine the location, size, and surface flux of the active regions. We will then use the time variation of the UV emission line and x-ray fluxes to determine what fluxes are due to the quiet and active regions separately. These data will provide SURFACE FLUXES for the quiet and active regions separately. We will then will model BOTH REGIONS independently using an emission measure analysis. We will also model any flares observed. The second part of the program will be a simultaneous UV/X-ray SURVEY with the objective of DETERMINING THE RANGE OF PHYSICAL MODELS APPLICABLE TO THE CHROMOSPHERES AND CORONAE OF RS CVN SYSTEMS. We propose to obtain emission line fluxes (SWP-LO) and Mg II line profiles (LWP-HI) of all bright RS CVns observed by ROSAT from mid-July through September 1990 that meet the IUE observing constraints. About 17 systems in the Strassmeier catalog will likely be observed during this period. While many RS CVn systems have been observed separately by IUE and x-ray satellites, SIMULTANEOUS UV and x-ray observations are required to model these spatially inhomogenous and timevariable systems. This research program and the ROSAT RS CVn survey will constitute most of the data for the Ph.D. Thesis of the Lead Investigator, Anthony Veale.

Linsky, Jeffrey L.

101

[RS3PE-syndrome].  

PubMed

The RS3PE syndrome (Remitting Seronegative Symmetrical Synovitis with Pitting Edema) is a manifestation of rheumatoid arthritis in the elderly with a good prognosis. It usually presents as an acute, symmetric polysynovitis with edema of the dorsum of the hands and feet. Anti-inflammatory treatment with corticosteroids leads to prompt improvement. We describe the case of an 81 year old man with a primarily unilateral manifestation involving the right hand. A thrombosis of the axillary vein was suspected. Within a few days he developed a pitting edema of the dorsum of the other hand. Movement of both shoulders and wrists was painful. Low-dose corticosteroid therapy resulted in a rapid improvement of the edema and the inflammatory symptoms. PMID:10198988

Segerer, S; Dietz-Laukemann, P; Schattenkirchner, M

1999-02-01

102

Evaluation of MC4R [rs17782313, rs17700633], AGRP [rs3412352] and POMC [rs1042571] Polymorphisms with Obesity in Northern India  

PubMed Central

Objective Genetic variants of the melanocortin-4 receptor gene (MC4R), agouti related protein (AGRP) and proopiomelanocortin (POMC) are reported to be associated with obesity. Therefore, the aim of this study is to examine MC4R rs17782313, MC4R rs17700633, AGRP rs3412352 and POMCrs1042571 for any association with obesity in North Indian subjects. Methods The variants were investigated for association in 300 individuals with BMI ?30 kg/m2 and 300 healthy non-obese individuals BMI <30 kg/m2. The genotyping were analyzed by Taqman probes. The statistical analysis was performed by the SPSS software, ver.19 and p?0.05 was considered statistically significant. Results The genotypes of MC4R rs17782313 and POMC rs1042571 were significantly associated with obesity (C), (p=0.02; OR=1.7 and p=0.01; OR=1.6, respectively); however, MC4Rrs17700633 (p=0.001; OR=0.55) was associated with low risk. In addition, AGRPrs3412352 (p=0.93; OR=0.96) showed no association with obesity (BMI ?30 kg/m2) in North Indian subjects. Conclusion This study provides the report about the significant association of MC4R (rs17782313) and POMC (rs1042571) with morbid obesity (BMI ?30 kg/m2), but MC4R (rs17700633) and AGRP (rs34123523) did not show any association with obesity in the studied North Indian population.

Srivastava, Apurva; Mittal, Balraj; Prakash, Jai; Narain, Varun Shanker; Natu, S.M.; Srivastava, Neena

2014-01-01

103

A Super-Earth Transiting a Naked-eye Star  

NASA Astrophysics Data System (ADS)

We have detected transits of the innermost planet "e" orbiting 55 Cnc (V = 6.0), based on two weeks of nearly continuous photometric monitoring with the MOST space telescope. The transits occur with the period (0.74 days) and phase that had been predicted by Dawson & Fabrycky, and with the expected duration and depth for the crossing of a Sun-like star by a hot super-Earth. Assuming the star's mass and radius to be 0.963+0.051 - 0.029 M sun and 0.943 ± 0.010 R sun, the planet's mass, radius, and mean density are 8.63 ± 0.35 M ?, 2.00 ± 0.14 R ?, and 5.9+1.5 - 1.1 g cm-3, respectively. The mean density is comparable to that of Earth, despite the greater mass and consequently greater compression of the interior of 55 Cnc e. This suggests a rock-iron composition supplemented by a significant mass of water, gas, or other light elements. Outside of transits, we detected a sinusoidal signal resembling the expected signal due to the changing illuminated phase of the planet, but with a full range (168 ± 70 ppm) too large to be reflected light or thermal emission. This signal has no straightforward interpretation and should be checked with further observations. The host star of 55 Cnc e is brighter than that of any other known transiting planet, which will facilitate future investigations. Based on data from the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute for Aerospace Studies, and the University of British Columbia, with the assistance of the University of Vienna.

Winn, Joshua N.; Matthews, Jaymie M.; Dawson, Rebekah I.; Fabrycky, Daniel; Holman, Matthew J.; Kallinger, Thomas; Kuschnig, Rainer; Sasselov, Dimitar; Dragomir, Diana; Guenther, David B.; Moffat, Anthony F. J.; Rowe, Jason F.; Rucinski, Slavek; Weiss, Werner W.

2011-08-01

104

A SUPER-EARTH TRANSITING A NAKED-EYE STAR  

SciTech Connect

We have detected transits of the innermost planet 'e' orbiting 55 Cnc (V = 6.0), based on two weeks of nearly continuous photometric monitoring with the MOST space telescope. The transits occur with the period (0.74 days) and phase that had been predicted by Dawson and Fabrycky, and with the expected duration and depth for the crossing of a Sun-like star by a hot super-Earth. Assuming the star's mass and radius to be 0.963{sup +0.051}{sub -0.029} M{sub sun} and 0.943 {+-} 0.010 R{sub sun}, the planet's mass, radius, and mean density are 8.63 {+-} 0.35 M{sub +}, 2.00 {+-} 0.14 R{sub +}, and 5.9{sup +1.5}{sub -1.1} g cm{sup -3}, respectively. The mean density is comparable to that of Earth, despite the greater mass and consequently greater compression of the interior of 55 Cnc e. This suggests a rock-iron composition supplemented by a significant mass of water, gas, or other light elements. Outside of transits, we detected a sinusoidal signal resembling the expected signal due to the changing illuminated phase of the planet, but with a full range (168 {+-} 70 ppm) too large to be reflected light or thermal emission. This signal has no straightforward interpretation and should be checked with further observations. The host star of 55 Cnc e is brighter than that of any other known transiting planet, which will facilitate future investigations.

Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Matthews, Jaymie M.; Kallinger, Thomas; Dragomir, Diana [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Dawson, Rebekah I.; Holman, Matthew J.; Sasselov, Dimitar [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Fabrycky, Daniel [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Kuschnig, Rainer; Weiss, Werner W. [University of Vienna, Institute for Astronomy, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Guenther, David B. [Department of Astronomy and Physics, Saint Mary's University, Halifax, NS B3H 3C3 (Canada); Moffat, Anthony F. J. [Department de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, QC H3C 3J7 (Canada); Rowe, Jason F. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Rucinski, Slavek [Department of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto, ON M5S 3H4 (Canada)

2011-08-10

105

An RS232-C local area network  

Microsoft Academic Search

A description is given of a local area network (LAN) used to link PCs to other serial devices using an RS-232-C interface. The hardware and software elements of the network controller are explained in terms of an actual implementation. The LAN design reflects a strategy of providing a transparent switching capability using only RS-232-C data transmission. The implementation involved the

S. Leonard; T. Cochran

1989-01-01

106

IUE spectra of a flare in the RS Canum Venaticorum-type system UX Arietis  

NASA Technical Reports Server (NTRS)

IUE spectra of UX Ari obtained during the large flare of 1979 January 1 exhibit chromospheric and transition-region emission-line fluxes about 2.5 and 5.5 times brighter than quiescent fluxes, respectively, and up to 1400 times brighter than the quiet sun. A high-dispersion spectrum of the 2000-3000 A region exhibits enhanced Fe II emission, which is probably associated mainly with the K0 IV star, and enhanced Mg II emission with asymmetric wings extending to +475 km/s. These line wings are interpreted as evidence for mass flow from the K0 IV star to the G5 V star. A speculative scenario of major long-lived RS CVn flares is proposed in which the component stars have very large corotating flux tubes, which occasionally interact. Magnetic reconnection results in flux tubes that temporarily connect the two stars.

Simon, T.; Linsky, J. L.; Schiffer, F. H., III

1980-01-01

107

RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e  

SciTech Connect

Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 {+-} 0.4) M{sub +}. For 55 Cnc e, the correct period is 0.7365 days-the shortest of any known planet-and the minimum mass is (8.3 {+-} 0.3) M{sub +}. This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.

Dawson, Rebekah I.; Fabrycky, Daniel C., E-mail: rdawson@cfa.harvard.ed, E-mail: daniel.fabrycky@gmail.co [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-10, Cambridge, MA 02138 (United States)

2010-10-10

108

Radial Velocity Planets De-aliased: A New, Short Period for Super-Earth 55 Cnc e  

NASA Astrophysics Data System (ADS)

Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 ± 0.4) M ?. For 55 Cnc e, the correct period is 0.7365 days—the shortest of any known planet—and the minimum mass is (8.3 ± 0.3) M ?. This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.

Dawson, Rebekah I.; Fabrycky, Daniel C.

2010-10-01

109

High Resolution Radio and IR Observations of AGB Stars  

NASA Astrophysics Data System (ADS)

Asymptotic Giant Branch Stars (AGB) are evolved, mass losing red giants with tenuous molecular envelopes which have been the subject of much recent study using infrared and radio interferometers. In oxygen rich stars, radio SiO masers form in the outer regions of the molecular envelopes and are powerful diagnostics of the extent of these envelopes. Spectroscopically resolved infrared interferometry helps constrain the extent of various species in the molecular layer. We made VLBA 7 mm SiO maser, Keck Interferometer near IR and VLTI/MIDI mid IR high resolution observations of the stars U Ari, W Cnc, RX Tau, RT Aql, S Ser and V Mon. This paper presents evidence that the SiO is depleted from the gas phase and speculate that it is frozen onto Al2O3 grains and that radiation pressure on these grains help drive the outflow.

Cotton, W.; Perrin, G.; Millan-Gabet, R.; Delaa, O.; Mennesson, B.

2012-07-01

110

Ares V and RS-68B  

NASA Technical Reports Server (NTRS)

Ares V is the heavy lift vehicle NASA is designing for lunar and other space missions. It has significantly more lift capability than the Saturn V vehicle used for the Apollo missions to the moon. Ares V is powered by two recoverable 5.5 segment solid rocket boosters and six RS-68B engines on the core stage. The upper stage, designated as the Earth Departure Stage, is powered by a single J-2X engine. This paper provides an overview of the Ares V vehicle and the RS-68B engine, an upgrade to the Pratt & Whitney Rocketdyne RS-68 engine developed for the Delta IV vehicle.

Creech, Steve; Taylor, Jim; Bellamy, Scott; Kuck, Fritz

2008-01-01

111

A Modern Take on the RV Classics: N-body Analysis of GJ 876 and 55 Cnc  

NASA Astrophysics Data System (ADS)

Over the past two decades, radial velocity (RV) observations have uncovered a diverse population of exoplanet systems, in particular a subset of multi-planet systems that exhibit strong dynamical interactions. To extract the model parameters (and uncertainties) accurately from these observations, one requires self-consistent n-body integrations and must explore a high-dimensional 7 x number of planets) parameter space, both of which are computationally challenging. Utilizing the power of modern computing resources, we apply our Radial velocity Using N-body Differential Evolution Markov Chain Monte Carlo code (RUN DEMCMC) to two landmark systems from early exoplanet surveys: GJ 876 and 55 Cnc. For GJ 876, we analyze the Keck HIRES (Rivera et al. 2010) and HARPS (Correia et al. 2010) data and constrain the distribution of the Laplace argument. For 55 Cnc, we investigate the orbital architecture based on a cumulative 1086 RV observations from various sources and transit constraints from Winn et al. 2011. In both cases, we also test for long-term orbital stability.

Nelson, Benjamin E.; Ford, E. B.; Wright, J.

2013-01-01

112

LPT to RS232 communication converter  

Microsoft Academic Search

\\u000a The base idea of this paper came as a result of using of some data acquisition systems controlled by an application made in\\u000a LabWindows CVI. The communication between PC and the acquisition systems is made through RS232 interface. The main problem\\u000a appeared is the impossibility to use the acquisition system for fast bidirectional data transfer using a RS232 protocol. As

Grofu Florin; Cercel Constantin

113

0.8-6?m calibrated spectrum of 55 Cnc (Crossfield, 2012)  

NASA Astrophysics Data System (ADS)

This work presents the flux-calibrated spectrum of the star 55 Cancri, as observed from with SpeX on the NASA IRTF, Mauna Kea Observatory, Hawai'i, U.S.A. Reduction of the observations is described in the associated paper. (1 data file).

Crossfield, I. J. M.

2012-08-01

114

The Metallicity and Lithium Abundances in the Repeating Novae, RS Oph and T CrB  

NASA Astrophysics Data System (ADS)

The subclass of symbiotic stars that has been suggested to be one of the sources of supernovae of type Ia is the repeating novae. Spectroscopic orbits of TCrB and RS Oph indicate that the white dwarfs in those systems have masses close to 1.4 MSun and hence they are vulnerable to catastrophic collapse if they accumulate additional mass from their red giant companions. To investigate the nature of their companions we obtained high res (35,000) spectra of both RS Oph and TCrB in 2004 with the echelle spectrograph of the Apache Point 3.5-m telescope. The purpose was to derive as much information about the red giant component that has been losing mass, some of which has probably been captured by the white dwarf. Of particular interest is the possibility that the red giant has lost much of its hydrogen envelope which might indicate that the mass-transfer process had reached the point that a supernova outburst (rather than just a repeat of the nova outburst) is imminent. Standard methods were used to derive the effective temperature and gravity of the cool star. Using model atmospheres we have been able to derive the metallicity of the stars. Using lines of Si, Ti, Fe and Ni we found RS Oph to show small metal excess. A small metal deficiency was found for TCrB. Within the uncertainties a solar metallicity is possible for both stars. Both stars show a strong Li line. For 41 other symbiotic stars observed at the Asiago Observatory, 28 showed no Li line and 13 were too severely blended to make a judgment. It is not clear if the lithium in the two repeating nova systems is due to processes within the red giant or to capture by the red giant of Li produced in the nova explosions.

Wallerstein, George; Harrison, T.; Munari, U.

2006-12-01

115

Extremely active long-period RS CVn binary HD 12545  

NASA Technical Reports Server (NTRS)

The active-chromosphere giant HD 12545 is noteworthy for its remarkable 1990 photmetric amplitude of 0.6 mag in V, which implies that nearly half the visible hemisphere of the star was covered by cool spots. We report the results of a spectroscopic study of HD 12545, showing it to be an active-chromosphere binary with an orbital period of 23.97 days. We establish the spectral type as KO III, and measure v sin i = 17 +/- 2 km/s. The various indicators of activity in the optical and ultraviolet suggest that HD 12545 is one of the most active RS CVn systems yet observed. H alpha is a broad, variable emission feature, with a strength comparable to what is observed in very active RS CVn systems such as V711 Tau (HR 1099) or II Peg. The surface fluxes of chromospheric and transition-regions lines in the UV range from 10 to nearly 400 times the solar values. With a moderately strong Li I lambda 6707 feature and a large space motion, HD 12545 is an unusual but not unique giant, since these properties are similar to those of the single active-chromosphere giant HD 33798.

Bopp, Bernard W.; Fekel, Francis C.; Aufdenberg, Jason P.; Dempsey, Robert; Dadonas, Virgilijus

1993-01-01

116

Centrifugal Force Induced Collapse of Strange Stars Into Black Holes  

NASA Astrophysics Data System (ADS)

It has been suggested that there could be objects even more compact than neutron stars, like the so-called strange stars, P-stars, and magnetars. Strange stars are collapsed stars consisting of u, d, and s quarks. P-stars are a new class of compact stars made of u and d quarks in ?-equilibrium with electrons in an Abelian chromomagnetic condensate. It has also been shown that a particle in a circular orbit around a stationary black hole is subject to a centrifugal force that turns out to be directed inwards if the particle orbit radius is between the Schwarzschild radius rs and 3rs/2. Here it is proposed that rotation of a sufficiently compact collapsed object may lead to a centrifugal force induced collapse to a black hole that could emit short gamma-ray bursts.

de Paolis, F.; Ingrosso, G.; Nucita, A. A.; Qadir, Asghar

117

A search for wide visual companions of exoplanet host stars: The Calar Alto Survey  

NASA Astrophysics Data System (ADS)

We have carried out a search for co-moving stellar and substellar companions around 18 exoplanet host stars with the infrared camera MAGIC at the 2.2 m Calar Alto telescope, by comparing our images with images from the all sky surveys 2MASS, POSS I and II. Four stars of the sample namely HD 80606, 55 Cnc, HD 46375 and BD-10°3166, are listed as binaries in the Washington Visual Double Star Catalogue (WDS). The binary nature of HD 80606, 55 Cnc, and HD 46375 is confirmed with both astrometry as well as photometry, thereby the proper motion of the companion of HD 46375 was determined here for the first time. We derived the companion masses as well as the longterm stability regions for additional companions in these three binary systems. We can rule out further stellar companions around all stars in the sample with projected separations between 270 AU and 2500 AU, being sensitive to substellar companions with masses down to ˜ 60 {MJup} (S/N=3). Furthermore we present evidence that the two components of the WDS binary BD-10°3166 are unrelated stars, i.e this system is a visual pair. The spectrophotometric distance of the primary (a K0 dwarf) is ˜ 67 pc, whereas the presumable secondary BD-10°3166 B (a M4 to M5 dwarf) is located at a distance of 13 pc in the foreground.

Mugrauer, M.; Neuhäuser, R.; Mazeh, T.; Guenther, E.; Fernández, M.; Broeg, C.

2006-05-01

118

Cepheid companions? FM Aquilae, FN Aquilae, RX Aurigae, Y Lacertae, and RS Orionis  

NASA Technical Reports Server (NTRS)

IUE spectra have been used to search for companions of FN Aql and RX Aur, two classical Cepheids which have been tentatively identified as binary stars on the basis of cyclic variations in their pulsation periods. Three other Cepheids, FM Aql, Y Lac, and RS Ori, suspected of having blue companions from the (U-B), (B-V) diagram, have also been investigated. There is no indication of a companion of FM Aql, FN Aql, and RX Aur. If these stars have companions, they must be at least as cool as A0 V, Al V, and A1 V, respectively.

Evans, Nancy Remage; Szabados, Laszlo; Udalska, Joanna

1990-01-01

119

V474 Car: A RARE HALO RS CVn BINARY IN RETROGRADE GALACTIC ORBIT  

SciTech Connect

We report the discovery that the star V474 Car is an extremely active, high velocity halo RS CVn system. The star was originally identified as a possible pre-main-sequence star in Carina, given its enhanced stellar activity, rapid rotation (10.3 days), enhanced Li, and absolute magnitude which places it above the main sequence (MS). However, its extreme radial velocity (264 km s{sup -1}) suggested that this system was unlike any previously known pre-MS system. Our detailed spectroscopic analysis of echelle spectra taken with the CTIO 4 m finds that V474 Car is both a spectroscopic binary with an orbital period similar to the photometric rotation period and metal-poor ([Fe/H] {approx_equal}-0.99). The star's Galactic orbit is extremely eccentric (e {approx_equal} 0.93) with a perigalacticon of only {approx}0.3 kpc of the Galactic center-and the eccentricity and smallness of its perigalacticon are surpassed by only {approx}0.05% of local F/G-type field stars. The observed characteristics are consistent with V474 Car being a high-velocity, metal-poor, tidally locked, chromospherically active binary, i.e., a halo RS CVn binary, and one of only a few such specimens known.

Bubar, Eric J.; Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Jensen, Eric L. N. [Swarthmore College, Department of Physics and Astronomy, 500 College Avenue, Swarthmore, PA 19081 (United States); Walter, Frederick M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

2011-04-15

120

The remarkable abundance pattern of the He-weak BP star HR 6000, and its implications for theories of CP stars  

NASA Astrophysics Data System (ADS)

The remarkable abundance anomalies of the He-weak Bp star HR 6000 are discussed, based on detailed line identifications in the wavelength range 3323-5316 A present in a separate paper. A spectacular absence of Si and significant deficiencies of He and C are coupled with a large overabundance of Fe; Ti, Cr, P, and Mn are also enhanced. Ga, Hg, and Kr are not observed, while Xe is possibly seen. The work confirms some of the results of the IUE analysis by Castelli et al. (1981), but differs significantly in some respects. The anomalies in HR 6000 are compared with those in the three 'prototype' Bp stars 3 Cen A, Kappa Cnc, and Alpha Scl, and with the OB subdwarfs. The marked differences of HR 6000 from each of these types of Bp star make interpretation of the abundance anomalies difficult, both in terms of diffusion and nucleosynthesis. The star deserves a detailed model-atmosphere analysis.

Andersen, J.; Jaschek, M.; Cowley, C. R.

1984-03-01

121

Spots on T Tauri stars  

NASA Astrophysics Data System (ADS)

Periodic light curves were recorded for the following 15 T Tauri stars (for nine of which this was the first detection of periodic variability): V 410 Tau, DF Tau, UX Tau A, FK 1, FK 2, WK 2, DN Tau, GW Ori, SY Cha, LH(alpha) 332-20, LH(alpha) 332-21, CoD-33-deg 10685, RY Lup, SR 12, and SR 9. The previously reported periodic variability of the SY Cha and RY Lup stars was confirmed. These periodic variations are thought to result from rotational modulation by a group of spots at the stellar surface. The properties of spots on 11 stars were deduced from extensive light-curve synthesis. In most cases, they were found to be comparable to the properties of spots found on RS CVn stars.

Bouvier, J.; Bertout, C.

1989-02-01

122

Star Formation  

NASA Astrophysics Data System (ADS)

Stars are one of the most important constituents of the Universe, and understanding their formation is crucial to many areas of astrophysics. Stars form from dense molecular gas, and they tend not to form in isolation. Stars often form in binary and multiple systems, and these systems tend to form in clusters with 102-105 members. Stars also form with a wide range of masses, from substellar brown dwarfs with masses < 0. 1 M ? to massive stars > 100 M ?, and wherever stars form the distribution of their masses seems always to be the same. This chapter will review our current understanding of star formation from cold gas to young star clusters.

Goodwin, Simon

123

Novel biosensor-based microarray assay for detecting rs8099917 and rs12979860 genotypes  

PubMed Central

AIM: To evaluate a novel biosensor-based microarray (BBM) assay for detecting rs12979860 and rs8099917 genotypes. METHODS: Four probes specific for rs8099917C/T or rs12979860G/T detection and three sets of quality control probes were designed, constructed and arrayed on an optical biosensor to develop a microarray assay. Two sets of primers were used in a one tube polymerase chain reaction (PCR) system to amplify two target fragments simultaneously. The biosensor microarray contained probes that had been sequenced to confirm that they included the rs8099917C/T or rs12979860G/T alleles of interest and could serve as the specific assay standards. In addition to rehybridization of four probes of known sequence, a total of 40 clinical samples collected from hepatitis C seropositive patients were also tested. The target fragments of all 40 samples were amplified in a 50 ?L PCR system. Ten ?L of each amplicon was tested by BBM assay, and another 40 ?L was used for sequencing. The agreement of the results obtained by the two methods was tested statistically using the kappa coefficient. The sensitivity of the BBM assay was evaluated using serial dilutions of ten clinical blood samples containing 103-104 white cells/?L. RESULTS: As shown by polyacrylamide gel electrophoresis, two target segments of the interleukin 28B-associated polymorphisms (SNPs) were successfully amplified in the one-tube PCR system. The lengths of the two amplified fragments were consistent with the known length of the target sequences, 137 and 159 bps. After hybridization of the PCR amplicons with the probes located on the BBM array, the signals of each allele of both the rs8099917 SNPs and rs12979860 SNPs were observed simultaneously and were clearly visible by the unaided eye. The signals were distinct from each other, could be interpreted visually, and accurately recorded using an ordinary digital camera. To evaluate the specificity of the assay, both the plasmids and clinical samples were applied to the microarray. First, 30 PCR amplicons of the various SNP alleles were hybridized on the BBM microarray. Full agreement between plasmids and the BBM assay was observed, with 30/30 correct matches (100%). The kappa value for the BBM assay with plasmids was 1.00 (P < 0.05). For the 40 clinical blood samples, the BBM assay hybridization and direct sequencing results were compared for each amplicon. For patient blood samples, agreement was 28/28 for rs8099917T/T, 9/11 for rs8099917T/G, 1/1 for rs8099917G/G, 24/24 for rs12979860C/C, 11/14 for rs12979860C/T, and 2/2 for rs12979860T/T. Only five clinical samples of amplicon assay and direct sequencing results were discordant and heterozygotes: 2/11 rs8099917T/G and 3/14 rs12979860C/T. The agreement of outcomes between BBM assay and direct sequencing for the detection of rs8099917 and rs12979860 was 95% and 92.5%, respectively; and the corresponding kappa values were 0.88 and 0.85 (A kappa value > 0.75 was defined as substantial agreement). The BBM assay and sequencing had similar specificities for detection and identification of the two SNPs and their alleles. The sensitivity evaluation showed that the BBM assay could detect and identify SNP sequences present in blood samples containing as few as 102 white blood cells/?L. CONCLUSION: This biosensor microarray assay was highly specific, sensitive, rapid and easy to perform. It is compatible with clinical practice for detection of rs8099917 and rs12979860.

Li, Pei-Yuan; Zhou, Xiao-Jun; Yao, Lan; Fang, Xin-Hua; Ren, Jiang-Nan; Song, Jia-Wu

2012-01-01

124

Beryllium abundances in parent stars of extrasolar planets: 16 Cygni A & B and rho (1) CANCRI  

NASA Astrophysics Data System (ADS)

The (9) Be ii lambda 3131 Angstroms doublet has been observed in the solar-type stars 16 Cyg A & B and in the late G-type star rho (1) Cnc, to derive their beryllium abundances. 16 Cyg A & B show similar (solar) beryllium abundances while 16 Cyg B, which has been proposed to have a planetary companion of ~ 2 M_Jup, is known to be depleted in lithium by a factor larger than 6 with respect to 16 Cyg A. Differences in their rotational histories which could induce different rates of internal mixing of material, and the ingestion of a similar planet by 16 Cyg A are discussed as potential explanations. The existence of two other solar-type stars which are candidates to harbour planetary-mass companions and which show lithium and beryllium abundances close to those of 16 Cyg A, requires a more detailed inspection of the peculiarities of the 16 Cyg system. For rho (1) Cnc, which is the coolest known object candidate to harbour a planetary-mass companion (M > 0.85 M_Jup), we establish a precise upper limit for its beryllium abundance, showing a strong Be depletion which constrains the available mixing mechanisms. Observations of similar stars without companions are required to assess the potential effects of the planetary companion on the observed depletion. It has been recently claimed that rho (1) Cnc appears to be a subgiant. If this were the case, the observed strong Li and Be depletions could be explained by a dilution process taking place during its post-main sequence evolution. Based on observations made with the Nordic Optical and William Herschel Telescopes, which are operated on the island of La Palma by the NOT Scientific Association and the Isaac Newton Group, respectively, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof\\'\\i sica de Canarias.

Garcia Lopez, R. J.; Perez de Taoro, M. R.

1998-06-01

125

Strange stars  

Microsoft Academic Search

Strange matter, a form of quark matter that is postulated to be absolute stable, may be the true ground stage of the hadrons. If this hypothesis is correct, neutron stars may convert to 'strange stars'. The mass-radius relation for strange stars is very different from that of neutron stars; there is no minimum mass, and for mass of 1 solar

Charles Alcock; Edward Farhi; Angela Olinto

1986-01-01

126

Strange stars  

NASA Technical Reports Server (NTRS)

Strange matter, a form of quark matter that is postulated to be absolute stable, may be the true ground stage of the hadrons. If this hypothesis is correct, neutron stars may convert to 'strange stars'. The mass-radius relation for strange stars is very different from that of neutron stars; there is no minimum mass, and for mass of 1 solar mass or less, mass is proportional to the cube of the radius. For masses between 1 solar mass and 2 solar masses, the radii of strange stars are about 10 km, as for neutron stars. Strange stars may have an exposed quark surface, which is capable of radiating at rates greatly exceeding the Eddington limit, but has a low emissivity for X-ray photons. The stars may have a thin crust with the same composition as the preneutron drip outer layer of a conventional neutron star crust. Strange stars cool efficiently via neutrino emission.

Alcock, Charles; Farhi, Edward; Olinto, Angela

1986-01-01

127

Be Stars  

NASA Astrophysics Data System (ADS)

A Be star (pronounced `bee-ee' star) is a non-supergiant B-type star whose spectrum displays or has displayed one or more Balmer lines in emission and Be is the notation for the spectral classification of such a star (see also CLASSIFICATION OF STELLAR SPECTRA). `Classical' Be stars are believed to have acquired the circumstellar (CS) material that produces the Balmer emission through ejection of...

Peters, G.; Murdin, P.

2000-11-01

128

RS3PE asociado a tuberculosis  

Microsoft Academic Search

The remitting seronegative symmetrical synovitis with pitting edema of the elderly patient with edema and fovea (RS3PE), characterizes for theappearanceofonepolyarthritissymmetricalwithfoveainthebackof the hands, and negative reumatoideal factor. The association to tubercu - losis had not been described before. One presents the case of a 89-year- old patient who consulted for anorexia of month and a half of evolution accompanied of edema

F. J. NICOLÁS-SÁNCHEZ; J. R. ROZADILLASACANELL; A. GORTOROMÍ

129

New Photometric Observations of RS Oph  

NASA Astrophysics Data System (ADS)

The recurrent nova RS Oph is a long period (~455 days) binary system consisting of a hot white dwarf with mass close to the Chandrasekhar limit and an M-type giant secondary. Here we present the results of photometric observations of this nova which were made during recent years with the telescopes of the Sternberg Astronomical Institute in Crimea.

Voloshina, Irina; Metlov, Vladimir

2013-01-01

130

The 3Rs program: the Colorado experience.  

PubMed

COPIC Insurance Company is a Colorado-based medical liability carrier. From October of 2000 to the present, it has employed an early intervention program called the 3Rs program standing for recognize, respond, and resolve. The program emphasizes disclosure, transparency, apology, and patient benefits. The origins of the program, its operational aspects, and results of implementation are discussed. PMID:18981795

Quinn, Richert E; Eichler, Mary C

2008-12-01

131

Mr. R.'s World of Math  

NSDL National Science Digital Library

Mr. R.'s World of Math is a teacher-created collection of math videos, poems, stories, songs, and challenges to help students master basic math functions. In addition to videos there are printable student handouts for the math challenges and several powerpoint demonstrations.

132

Building on the Three Rs of Professionalism  

ERIC Educational Resources Information Center

In this article, the author offers suggestions, based on the insightful article "The Three Rs of Professionalism" by Patricia H. Phelps ("Record" Winter 2006), for beginning teachers as they prepare for successful secondary classroom careers. As a professor of general secondary methods, the author emphasizes and has modeled the importance of six…

Heckendorn, Rick

2006-01-01

133

RS Oph: A Recurrent Symbiotic Nova Explosion  

NASA Astrophysics Data System (ADS)

RS Oph is a recurrent symbiotic nova, in which a white dwarf orbits inside the outer layers/wind of a red giant. The system has had numerous recorded outbursts (1898, 1933, 1958, 1967, 1985). The most recent outburst began on 2006 February 12. In previous outbursts, RS Oph was well studied in the optical, ultraviolet (IUE), and the radio. There were 6 pointings by EXOSAT during the 1985 outburst but the first was not until 55 days after discovery. For the 2006 outburst, X-ray observations began within a few days of discovery and now include data from RXTE, Swift, Chandra, and XMM-Newton. We report that RS Oph was extremely bright in X-rays at maximum and its X-ray spectrum has evolved on a nearly daily basis. The X-ray observations, in combination with radio observations obtained with the VLA and VLBA, confirm the current model for the outburst: a massive white dwarf accretes material from a red giant secondary until a thermonuclear runaway ensues and high velocity gas is ejected from the white dwarf. Because the white dwarf is orbiting inside the outer layers/wind of the red giant, a strong shock system is established, the evolution of which can be followed from observations across the electromagnetic spectrum. We will report on the X-ray, infrared (Spitzer), and radio observations, obtained during this outburst, along with the current state of RS Oph. S. Starrfield acknowledges partial support to ASU from NSF and NASA.

Starrfield, Sumner; Ness, J.; Drake, J.; Krautter, J.; Orio, M.; Schwarz, G.; Vanlandingham, K.; Bode, M. F.; Evans, A.; Gehrz, R. D.; Woodward, C. E.; O'Brien, T. J.; Gehrels, N.; Osborne, J. P.; Beardmore, A.; Page, K.; Bond, H. E.; Eyres, S. P.; Davis, R.

2006-06-01

134

Properties of Sun-like Stars with Planets: ?1 Cancri, ? Bootis, and ? Andromedae  

NASA Astrophysics Data System (ADS)

Planets have been reported orbiting the Sun-like stars ?1 Cnc, ? Boo, and ? And based on low-amplitude radial velocity variations. We have derived information on the first two stars from analysis of spectra, as well as parallel records of high-precision Strömgren b and y photometry and Ca II H + K fluxes. In the case of ?1 Cnc, the upper limit (peak to peak) of nondetection of photometric variability at the orbital period is ?y ~ 0.0004 mag. The possibility of a planetary transit cannot be ruled out completely from the photometric data. Variations of the Ca II fluxes suggest a rotational period of ~42 days, in agreement with the inferred v sin i ~ 2 km s-1. The age of ?1 Cnc is ~5 Gyr, based on its average Ca II flux and a relation between Ca II flux and age. The star ? Boo, unlike the other reported solar-type stars with planets, is relatively young (~2 Gyr). Despite its young age, it is photometrically nonvariable at the orbital period with an amplitude of ?(b + y)/2 ~ 0.0004 mag (peak to peak); however, small-amplitude interseasonal variability is seen. No planetary transits were found in the photometry, which limits the inclination of the planet's orbital plane to Earth's line of sight to less than 83° (where 90° is coplanar). The Ca II record shows a weakly significant rotational period near 3.3 days, coincident with the orbital period of the companion. The Ca II record also shows a period of 116 days that has persisted for 30 years and is not seen in the photometric record. The persistence and timescale of this Ca II variation mean that it has no counterpart in Sun-like magnetic activity. The amplitude of the reflex velocity of the parent star (~450 m s-1) is much larger than the radial velocity perturbations expected from the presence of either surface inhomogeneities or line-bisector variations. Thus the anticipated perturbations from those stellar effects do not refute the inference of reflex velocities. We have few Ca II flux measurements for ? And. Its age and rotational period are estimated to be ~5 Gyr and 12 days, respectively. Our results for ?1 Cnc and ? Boo are consistent with the explanation of planets as the cause of the velocity variations. Based on observations made at Mount Wilson Observatory, operated by the Mount Wilson Institute under an agreement with the Carnegie Institution of Washington.

Baliunas, Sallie L.; Henry, Gregory W.; Donahue, Robert A.; Fekel, Francis C.; Soon, Willie H.

1997-01-01

135

Stars and Star Myths.  

ERIC Educational Resources Information Center

Myths and tales from around the world about constellations and facts about stars in the constellations are presented. Most of the stories are from Greek and Roman mythology; however, a few Chinese, Japanese, Polynesian, Arabian, Jewish, and American Indian tales are also included. Following an introduction, myths are presented for the following 32…

Eason, Oliver

136

Unified error model based spatial error compensation for four types of CNC machining center: Part II-unified model based spatial error compensation  

NASA Astrophysics Data System (ADS)

In this paper, a spatial error compensation method was proposed for CNC machining center based on the unified error model. The spatial error distribution was analyzed in this research. The result shows that the spatial error is relative to each axis of a CNC machine tool. Moreover, the spatial error distribution is non-linear and there is no regularity. In order to improve the modeling accuracy and efficiency, an automatic error modeling application was designed based on the orthogonal polynomials. To realize the spatial error compensation, a multi-thread parallel processing mode based error compensation controller was designed. Using the spatial error compensation method, the machine tools' accuracy is greatly improved compared to that with no compensation.

Fan, Kaiguo; Yang, Jianguo; Yang, Liyan

2014-12-01

137

OPMILL - MICRO COMPUTER PROGRAMMING ENVIRONMENT FOR CNC MILLING MACHINES THREE AXIS EQUATION PLOTTING CAPABILITIES  

NASA Technical Reports Server (NTRS)

OPMILL is a computer operating system for a Kearney and Trecker milling machine that provides a fast and easy way to program machine part manufacture with an IBM compatible PC. The program gives the machinist an "equation plotter" feature which plots any set of equations that define axis moves (up to three axes simultaneously) and converts those equations to a machine milling program that will move a cutter along a defined path. Other supported functions include: drill with peck, bolt circle, tap, mill arc, quarter circle, circle, circle 2 pass, frame, frame 2 pass, rotary frame, pocket, loop and repeat, and copy blocks. The system includes a tool manager that can handle up to 25 tools and automatically adjusts tool length for each tool. It will display all tool information and stop the milling machine at the appropriate time. Information for the program is entered via a series of menus and compiled to the Kearney and Trecker format. The program can then be loaded into the milling machine, the tool path graphically displayed, and tool change information or the program in Kearney and Trecker format viewed. The program has a complete file handling utility that allows the user to load the program into memory from the hard disk, save the program to the disk with comments, view directories, merge a program on the disk with one in memory, save a portion of a program in memory, and change directories. OPMILL was developed on an IBM PS/2 running DOS 3.3 with 1 MB of RAM. OPMILL was written for an IBM PC or compatible 8088 or 80286 machine connected via an RS-232 port to a Kearney and Trecker Data Mill 700/C Control milling machine. It requires a "D:" drive (fixed-disk or virtual), a browse or text display utility, and an EGA or better display. Users wishing to modify and recompile the source code will also need Turbo BASIC, Turbo C, and Crescent Software's QuickPak for Turbo BASIC. IBM PC and IBM PS/2 are registered trademarks of International Business Machines. Turbo BASIC and Turbo C are trademarks of Borland International.

Ray, R. B.

1994-01-01

138

RS3PE syndrome: an overview.  

PubMed

More than ten years ago McCarty et al. described the RS3PE syndrome based on their study of 23 patients. Numerous additional cases have since been reported. In addition to the isolated or "pure" type which probably forms part of the clinical spectrum of polymyalgia rheumatica, inflammatory swelling with pitting edema of the dorsum of the hands and/or feet can be observed in different inflammatory rheumatic diseases as well as in haematological and solid malignancies. PMID:10948764

Olivieri, I; Salvarani, C; Cantini, F

2000-01-01

139

STAR Publications  

Cancer.gov

STAR Publications The following citations are of reports that have been published in the scientific literature concerning the Study of Tamoxifen and Raloxifene (STAR). The citations are listed in reverse chronological order.

140

Human small Maf proteins form heterodimers with CNC family transcription factors and recognize the NF-E2 motif.  

PubMed

The transcription factor NF-E2, a heterodimeric protein complex composed of p45 and small Maf family proteins, is considered crucial for the regulation of erythroid gene expression and platelet formation. To facilitate the characterization of NF-E2 functions in human cells, we isolated cDNAs encoding two members of the small Maf family, MafK and MafG. The human mafK and mafG genes encode proteins of 156 and 162 amino acid residues, respectively, whose deduced amino acid sequences show approximately 95% identity to their respective chicken counterparts. Expression of mafK mRNA is high in heart, skeletal muscle and placenta, whereas mafG mRNA is abundant in skeletal muscle and is moderately expressed in heart and brain. Both are expressed in all hematopoietic cell lines, including those of erythroid and megakaryocytic lineages. In electrophoretic gel mobility shift assays binding to NF-E2 sites was found to depend on formation of homodimers or heterodimers with p45 and p45-related CNC family proteins. The results suggest that the small Maf family proteins function in human cells through interaction with various basic-leucine zipper-type transcription factors. PMID:9150357

Toki, T; Itoh, J; Kitazawa, J; Arai, K; Hatakeyama, K; Akasaka, J; Igarashi, K; Nomura, N; Yokoyama, M; Yamamoto, M; Ito, E

1997-04-24

141

Epigenetic silencing of BTB and CNC homology 2 and concerted promoter CpG methylation in gastric cancer.  

PubMed

BTB and CNC homology 2 (BACH2) is a lymphoid-specific transcription factor with a prominent role in B-cell development. Genetic polymorphisms within a single locus encoding BACH2 are associated with various autoimmune diseases and allergies. In this study, restriction landmark genomic scanning revealed methylation at a NotI site in a CpG island covering the BACH2 promoter in gastric cancer cell lines and primary gastric tumors. Increased methylation of the BACH2 promoter was observed in 52% (43/83) of primary gastric tumors, and BACH2 hypermethylation was significantly associated with decreased gene expression. Treatment with 5-aza-2'-deoxycytidine and/or trichostatin. A restored BACH2 expression in BACH2-silenced gastric cancer cell lines, and knockdown of BACH2 using short hairpin RNA (i.e. RNA interference) increased cell proliferation in gastric cancer cells. Clinicopathologic data showed that decreased BACH2 expression occurred significantly more frequently in intestinal-type (27/44, 61%) compared with diffuse-type (13/50, 26%) gastric cancers (P<0.001). Furthermore, BACH2 promoter methylation paralleled that of previously identified targets, such as LRRC3B, LIMS2, PRKD1 and POPDC3, in a given set of gastric tumors. We propose that concerted methylation in many promoters plays a role in accelerating gastric tumor formation and that methylated promoter loci may be targets for therapeutic treatment, such as the recently introduced technique of epigenetic editing. PMID:24858026

Haam, Keeok; Kim, Hee-Jin; Lee, Kyung-Tae; Kim, Jeong-Hwan; Kim, Mirang; Kim, Seon-Young; Noh, Seung-Moo; Song, Kyu-Sang; Kim, Yong Sung

2014-09-01

142

55 Cancri: A Coplanar Planetary System that is Likely Misaligned with its Star  

NASA Astrophysics Data System (ADS)

Most mechanisms invoked to explain the high spin-orbit angles observed for some transiting planets require them to pass through a phase of extremely high orbital eccentricity. This would seem to preclude high spin-orbit angles in systems with multiple, coplanar planets on circular orbits, since these mechanisms would produce planet-planet scattering. Although the 55 Cnc system contains such well-ordered planets, we use numerical simulations to demonstrate that they too are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star (without exciting the planets' eccentricities). Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. We predict that the most likely projected spin-orbit angle is 50 degrees, with a 30% chance of a retrograde configuration. Transit observations of the innermost planet - 55 Cnc e - may be used to test these predictions via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well- ordered, coplanar orbits that are inclined with respect to the stellar equator. This work was funded by a CITA National Fellowship and Canada's NSERC. SNR thanks the CNRS's PNP program and the NASA Astrobiology Institute's Virtual Planetary Laboratory team.

Kaib, Nathan A.; Raymond, S. N.; Duncan, M. J.

2012-01-01

143

STAR System.  

ERIC Educational Resources Information Center

The STAR System is a developmental guidance approach to be used with elementary school children in the 5th or 6th grades. Two basic purposes underlie STAR: to increase learning potential and to enhance personal growth and development. STAR refers to 4 basic skills: sensory, thinking, adapting, and revising. Major components of the 4 skills are:…

Doverspike, James E.

144

Outer atmospheres of late stars  

SciTech Connect

The short-wavelength spectra of the stars UX Ari during flare activity and in the quiet state and RW Aur are analyzed. An independent determination of the electron density made it possible to draw the reliable conclusion from the line intensities that the extent of the transition region between chromosphere and corona is considerably greater for these stars and Capella than for the sun. Two groups of stars are distinguished: 1) rotating red dwarfs; 2) subgiants belonging to systems of the RS C Vn-type and T Tau-type stars. The former are characterized by coronal loops emitting in the x-ray region. The appearance of considerable fluxes in lines of ions with T/sub i/roughly-equal10/sup 5/ /sup 0/K in stars of the latter group without x-ray enhancement is connected with direct heating with T = 10/sup 4/--10/sup 5/ /sup 0/K and with the development of upward-intensifying motions. Such a dynamical model of the outer atmosphere differs considerably from the usually considered outflow of the solar-wind type, efficiently cooling the coronas of stars with low gravity.

Katsova, M.M.

1982-11-01

145

The Orbital Period of the SU Ursae Majoris Star EK Trianguli Australis and Evidence for Ring-Like Accretion Disks in Long-Supercycle Length SU Ursae Majoris Stars  

NASA Astrophysics Data System (ADS)

An orbital period of 0.06288(5) d has been found from a radial velocity study of the H? emission line. In addition, we have detected an extra line emitting source located ~ 80(deg) apart from the vector joining the secondary--primary centers, as measured in the opposite sense to the binary rotational motion. This is not the expected location for the hotspot in dwarf novae. This anomaly could be removed by assuming a line emission lagging behind the white dwarf binary motion. In addition, we have estimated line emissivity (~ r(-alpha ) ) and disk radius (R equiv r_in/r_out) for 8 SU UMa stars. Most stars fit alpha = 1.8 +/- 0.1 but AK Cnc and WZ Sge strongly deviate from the mean; their emission line shapes can be explained assuming a post-outburst accretion disk mostly emitting close to the white dwarf (AK Cnc) and a ring-like disk (WZ Sge). In addition, we have found a tendency of long-supercycle length SU UMa stars to show very compact (large R; probably ring-like) accretion disks. If the supercycle length were basically controlled by the mass transfer rate (dot {M}), the inner disk radius would be a function of dot {M}. A white dwarf magnetic field ~ 5000 G is required to fit the truncation radius with the magnetosphere radius of SU UMa stars.

Mennickent, Ronald E.; Arenas, Jose

1998-06-01

146

The NOD2 Single Nucleotide Polymorphisms rs2066843 and rs2076756 Are Novel and Common Crohn's Disease Susceptibility Gene Variants  

PubMed Central

Background The aims were to analyze two novel NOD2 variants (rs2066843 and rs2076756) in a large cohort of patients with inflammatory bowel disease and to elucidate phenotypic consequences. Methodology/Principal Findings Genomic DNA from 2700 Caucasians including 812 patients with Crohn's disease (CD), 442 patients with ulcerative colitis (UC), and 1446 healthy controls was analyzed for the NOD2 SNPs rs2066843 and rs2076756 and the three main CD-associated NOD2 variants p.Arg702Trp (rs2066844), p.Gly908Arg (rs2066847), and p.Leu1007fsX1008 (rs2066847). Haplotype and genotype-phenotype analyses were performed. The SNPs rs2066843 (p?=?3.01×10?5, OR 1.48, [95% CI 1.23-1.78]) and rs2076756 (p?=?4.01×10?6; OR 1.54, [95% CI 1.28-1.86]) were significantly associated with CD but not with UC susceptibility. Haplotype analysis revealed a number of significant associations with CD susceptibility with omnibus p values <10?10. The SNPs rs2066843 and rs2076756 were in linkage disequilibrium with each other and with the three main CD-associated NOD2 mutations (D'>0.9). However, in CD, SNPs rs2066843 and rs2076756 were more frequently observed than the other three common NOD2 mutations (minor allele frequencies for rs2066843 and rs2076756: 0.390 and 0.380, respectively). In CD patients homozygous for these novel NOD2 variants, genotype-phenotype analysis revealed higher rates of a penetrating phenotype (rs2076756: p?=?0.015) and fistulas (rs2076756: p?=?0.015) and significant associations with CD-related surgery (rs2076756: p?=?0.003; rs2066843: p?=?0.015). However, in multivariate analysis only disease localization (p<2×10?16) and behaviour (p?=?0.02) were significantly associated with the need for surgery. Conclusion/Significance The NOD2 variants rs2066843 and rs2076756 are novel and common CD susceptibility gene variants.

Tillack, Cornelia; Pfennig, Simone; Beigel, Florian; Jurgens, Matthias; Olszak, Torsten; Laubender, Rudiger P.; Weidinger, Maria; Muller-Myhsok, Bertram; Goke, Burkhard; Ochsenkuhn, Thomas; Lohse, Peter; Diegelmann, Julia; Czamara, Darina; Brand, Stephan

2010-01-01

147

A Far-Ultraviolet Spectroscopic Survey of RS CVn Binary Systems  

NASA Astrophysics Data System (ADS)

RS CVn systems are detached late-type binaries that are very active as a result of their tidally-enforced rapid rotation. They are actively studied and bright at X-ray and UV wavelengths, but very few have been observed by FUSE. Located in the FUSE spectral range are emission lines formed in plasma at 50,000 - 300,000 K (e.g., C III and O VI) and the coronal emission line Fe XVIII 974 A formed at 6,000,000 K, which permit us to measure the widths and velocity shifts to study stellar atmospheric dynamics and structure. We propose answer the following important questions, (1) Which star in selected active close binary systems is the dominant emitter in lines formed at different temperatures? Studies of Capella show that the 105 K lines are predominately from the G1 III star, whereas the coronal line is mostly from the G8 III star. (2) Are the broad profiles seen in these rapidly rotating stars due to geometrically extended structures rigidly rotating with the star, or are they due to some other mechanism? Observations of our selected high declination systems observed at different orbital phases will allow us to answer these questions. (3) Search for outflows and downflows in lines formed at different temperatures.

Redfield, S.

148

A novel RS BTC coding scheme for optical communications  

NASA Astrophysics Data System (ADS)

A novel Reed Solomon (RS) block turbo code (BTC) coding scheme of RS(63,58)×RS(63,58) for optical communications is proposed. The simulation results show that the net coding gain (NCG) of this scheme at the sixth iteration is more than that of other coding schemes at the third iteration for the bit error rate (BER) of 10-12. Furthermore, the novel RS BTC has shorter component code and rapider encoding and decoding speed. Therefore, the novel RS BTC coding scheme can be better used in high-speed long-haul optical communication systems, and the novel RS BTC can be regarded as a candidate code of the super forward error correction (super-FEC) code. Moreover, the encoding/decoding design and implementation of the novel RS BTC are also presented

Yuan, Jian-guo; Jia, Yue-xing; Hu, Yun-xia

2012-07-01

149

[RS3PE associated with tuberculosis].  

PubMed

The remitting seronegative symmetrical synovitis with pitting edema of the elderly patient with edema and fovea (RS3PE), characterizes for the appearance of one polyarthritis symmetrical with fovea in the back of the hands, and negative reumatoideal factor. The association to tuberculosis had not been described before. One presents the case of a 89-year-old patient who consulted for anorexia of month and a half of evolution accompanied of edema in hands and feet, with negative reumatoideal factor. He was presenting a pulmonary infiltrated, which microbiological study revealed the infection for Mycobacterium tuberculosis. PMID:18271654

Nicolás-Sánchez, F J; Rozadilla Sacanell, J R; Gort Oromí, A M; Torres Cortada, G; Soler Rosell, T; Sarrat-Nuevo, R M; Nicolás-Sánchez, M E; Cabau-Rubies, J

2007-10-01

150

Association of PTPN22 rs2476601 and EGFR rs17337023 Gene polymorphisms and rheumatoid arthritis in Zahedan, Southeast Iran.  

PubMed

In this study we aimed to evaluate the possible association of PTPN22 rs2476601 as well as epidermal growth factor receptor (EGFR) rs17337023 gene polymorphism and rheumatoid arthritis (RA) in a sample of Iranian population. This case-control study was performed on 120 patients with RA and 120 healthy subjects. Genomic DNA was extracted from whole blood and PTPN22 rs2476601 and EGFR rs17337023 polymorphisms were determined using tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). The results showed that PTPN22 rs2476601 CT genotype as well as rs2476601 T allele was a risk factor for susceptibility to RA (OR=5.89 95%CI = 1.78-19.48, P = 0.004 and OR = 4.78, 95%CI = 1.59-14.35, P = 0.003, respectively). We also found that EGFR rs17337023 AT and rs17337023 TT genotypes were risk factor for susceptibility to RA (OR = 9.94 95%CI = 3.65-26.73, P < 0.001 and OR = 3.66, 95%CI = 1.46-9.15, P = 0.005, respectively). In addition the EGFR rs17337023 T allele was a risk for predisposition to RA (OR = 1.56, 95%CI=1.06-2.30, P = 0.030). In conclusion, we found an association between PTPN22 rs2476601 and EGFR rs17337023 polymorphisms and the risk of RA in a sample of Iranian population. PMID:23350658

Hashemi, M; Atabaki, M; Daneshvar, H; Zakeri, Z; Eskandari-Nasab, E

2013-08-01

151

High-Speed RaPToRS  

NASA Astrophysics Data System (ADS)

The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

2008-11-01

152

Stationary Star  

NSDL National Science Digital Library

This is an activity about star movement due to the Earth's rotation. Learners will utilize the Sky Tonight online program to find the star that appears stationary in our night sky. They will then draw conclusions about the Earthâs rotation based on the position changes of certain stars. This activity requires the use of a computer with Internet access. This activity is Sky Tonight Activity 2 in a larger resource, Space Update.

153

Effects of Interleukin-10 Polymorphisms (rs1800896, rs1800871, and rs1800872) on Breast Cancer Risk: Evidence from an Updated Meta-Analysis.  

PubMed

Background: The associations between Interleukin-10 (IL-10) polymorphisms and breast cancer (BC) risk are inconsistent. This study was aimed to evaluate the relationship between IL-10 polymorphisms (rs1800896, rs1800871, and rs1800872) and BC risk. Methods: Databases, including PubMed, Web of Knowledge, Embase, and Chinese National Knowledge Infrastructure, were searched to find relevant studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of associations. Results: A total of 12 studies (4743 cancer cases and 5120 case-free controls) were eligible for meta-analysis. There were nine studies with 1851 cases and 1910 controls for rs1800896, six studies with 1034 cases and 1173 controls for rs1800871, and seven studies with 3637 cases and 3391 controls for rs1800872. Meta-analysis showed that rs1800896 and rs1800871 polymorphisms had no association with BC risk (for rs1800896: OR=1.060, 95% CI=0.785-1.432 in the dominant model, and OR=1.152, 95% CI=0.958-1.386 in the recessive model; for rs1800871: OR=0.952, 95% CI=0.859-1.056 in the dominant model, and OR=0.892, 95% CI=0.741-1.072 in the recessive model). However, rs1800872 polymorphism has association with BC risk based on the recessive model (OR=0.80, 95% CI=0.73-0.88). In the stratified analysis, when analyzed by the recessive model (CC vs. AA+AC), the ORs were 0.75 (95% CI=0.68-0.83) (p<0.00001) among Caucasians and 1.17 (95% CI=0.88-1.55) (p=0.27) among Asians. These results suggested that the CC homozygote has a 25% decreased risk of BC compared with those individuals with AA and AC genotypes in Caucasians. Conclusions: This meta-analysis showed that IL-10 rs1800896 and rs1800871 polymorphisms had no association with BC risk, while rs1800872 polymorphism had a decreased risk of BC in Caucasians. PMID:24720854

Dai, Zhi-Jun; Wang, Xi-Jing; Zhao, Yang; Ma, Xiao-Bin; Kang, Hua-Feng; Min, Wei-Li; Lin, Shuai; Yang, Peng-Tao; Liu, Xiao-Xu

2014-06-01

154

Neutron Stars  

NASA Technical Reports Server (NTRS)

Neutron stars were discovered almost 40 years ago, and yet many of their most fundamental properties remain mysteries. There have been many attempts to measure the mass and radius of a neutron star and thereby constrain the equation of state of the dense nuclear matter at their cores. These have been complicated by unknown parameters such as the source distance and burning fractions. A clean, straightforward way to access the neutron star parameters is with high-resolution spectroscopy. I will present the results of searches for gravitationally red-shifted absorption lines from the neutron star atmosphere using XMM-Newton and Chandra.

Cottam, J.

2007-01-01

155

Synthesis and identification of the monocation Tc(CPI) sub 6 sup + in Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and its hydrolysis products. [Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and monocation Tc(CPI) sub 6 sup +  

Microsoft Academic Search

The complex Tc(CNC(CHâ)âCOOCHâ)âCl (cation designated as Tc(CPI)â{sup +}) is one of a series of isonitrile-coordinated technetium complexes being investigated as a prototype radiopharmaceutical to evaluate myocardial perfusion. It has been prepared from the pertechnetate ion by aqueous NaâSâOâ reduction in the presence of the functionalized isocyanide ligand. The octahedral compound with its relatively reactive ester substituents is stable under aqueous

J. F. Kronauge; A. Davison; A. M. Roseberry; C. E. Costello; S. Maleknia; A. G. Jones

1991-01-01

156

Radio and IR interferometry of SiO maser stars  

NASA Astrophysics Data System (ADS)

Radio and infrared interferometry of SiO maser stars provide complementary information on the atmosphere and circumstellar environment at comparable spatial resolution. Here, we present the latest results on the atmospheric structure and the dust condensation region of AGB stars based on our recent infrared spectro-interferometric observations, which represent the environment of SiO masers. We discuss, as an example, new results from simultaneous VLTI and VLBA observations of the Mira variable AGB star R Cnc, including VLTI near- and mid-infrared interferometry, as well as VLBA observations of the SiO maser emission toward this source. We present preliminary results from a monitoring campaign of high-frequency SiO maser emission toward evolved stars obtained with the APEX telescope, which also serves as a precursor of ALMA images of the SiO emitting region. We speculate that large-scale long-period chaotic motion in the extended molecular atmosphere may be the physical reason for observed deviations from point symmetry of atmospheric molecular layers, and for the observed erratic variability of high-frequency SiO maser emission.

Wittkowski, Markus; Boboltz, David A.; Gray, Malcolm D.; Humphreys, Elizabeth M. L.; Karovicova, Iva; Scholz, Michael

2012-07-01

157

Spectroscopic orbits and variations of RS Ophiuchi  

NASA Astrophysics Data System (ADS)

Aims: The aims of our study are to improve the orbital elements of the giant and to derive the spectroscopic orbit for the white dwarf companion of the symbiotic system RS Oph. Spectral variations related to the 2006 outburst are also studied. Methods: We performed an analysis of about seventy optical and near infrared spectra of RS Oph that were acquired between 1998 and June 2008. The spectroscopic orbits were obtained by measuring the radial velocities of the cool component absorption lines and the broad H? emission wings, which seem to be associated with the hot component. A set of cF-type absorption lines were also analyzed for a possible connection with the hot component motion. Results: A new period of 453.6 days and a mass ratio, q = M_g/Mh = 0.59 ± 0.05 were determined. Assuming a massive white dwarf as the hot component (Mh = 1.2-1.4 M?) the red giant mass is Mg = 0.68-0.80 M? and the orbit inclination, i = 49°-52°. The cF-type lines are not associated with either binary component, and are most likely formed in the material streaming towards the hot component. We also confirm the presence of the Li I doublet in RS Oph and its radial velocities fit very well to the M-giant radial velocity curve. Regardless of the mechanism involved to produce lithium, its origin is most likely from within the cool giant rather than material captured by the giant at the time of the nova explosion. The quiescent spectra reveal a correlation of the H I and He I emission line fluxes with the monochromatic magnitudes at 4800 Å, indicating that the hot component activity is responsible for those flux variations. We also discuss the spectral characteristics around 54-55 and 240 days after the 2006 outburst. In April 2006 most of the emission lines present a broad pedestal with a strong and narrow component at about -20 km s-1 and two other extended emission components at -200 and +150 km s-1. These components could originate in a bipolar gas outflow supporting the model of a bipolar shock-heated shell expanding through the cool component wind perpendicularly to the binary orbital plane. Our observations also indicate that the cF absorption system was disrupted during the outburst, and restored about 240 days after the outburst, which is consistent with the resumption of accretion.

Brandi, E.; Quiroga, C.; Miko?ajewska, J.; Ferrer, O. E.; García, L. G.

2009-04-01

158

An X-ray-emitting blast wave from the recurrent nova RS Ophiuchi.  

PubMed

Stellar explosions such as novae and supernovae produce most of the heavy elements in the Universe. The onset of a nova is well understood as driven by runaway thermonuclear fusion reactions on the surface of a white dwarf in a binary star system; but the structure, dynamics and mass of the ejecta are not well known. In rare cases, the white dwarf is embedded in the wind nebula of a red-giant companion, and the explosion products plough through the nebula and produce X-ray emission. Here we report X-ray observations of such an event, from the eruption of the recurrent nova RS Ophiuchi. The hard X-ray emission from RS Ophiuchi early in the eruption emanates from behind a blast wave, or outward-moving shock wave, that expanded freely for less than 2 days and then decelerated owing to interaction with the nebula. The X-rays faded rapidly, suggesting that the blast wave deviates from the standard spherical shell structure. The early onset of deceleration indicates that the ejected shell had a low mass, the white dwarf has a high mass, and that RS Ophiuchi is therefore a progenitor of the type of supernova (type Ia) integral to studies of the expansion of the Universe. PMID:16855584

Sokoloski, J L; Luna, G J M; Mukai, K; Kenyon, Scott J

2006-07-20

159

Period04 FCAPT uvby Photometric Studies of Eight Magnetic CP Stars  

NASA Astrophysics Data System (ADS)

We present Four College Automated Photometric Telescope (FCAPT) differential Stromgren uvby photometry of 8 magnetic CP (mCP) stars: HD 5797 (V551 Cas), HD 26792 (DH Cam), HD 27309 (56 Tau, V724 Tau), HD 49713 (V740 Mon), HD 74521 (49 Cnc, BI Cnc), HD 120198 (84 UMa, CR UMa), HD 171263 (QU Ser), and HD 215441 (GL Lac, Babcock's star). Our data sets are larger than those of most mCP stars in the literature. These are the first FCAPT observations of HD 5797, HD 26792, HD 49713, and HD 171263. Those for the remaining four stars substantially extend published FCAPT data. The FCAPT observed some stars for a longer time range and with greater accuracy than other optical region automated photometric telescopes.Our goals were to determine very accurate periods, the u, v, b, and y amplitudes, and if there were any long period periods. In addition we wanted to compare our results with those of magnetic field measurements to help interpret the light curves.We used the Period04 computer program to analyze the light curves. This program provides errors for the derived quantities as it fits the light curve. Our derived periods of 68.046 +/- 0.008 days for HD 5797, 3.80205 +/- 0.00006 days for HD 26792, 1.56889 +/- 0.000002 days for HD 27309, 2.13536 +/- 0.00002 days for HD 49713, 7.0505 +/- 0.0001 days for HD 74521, 1.38577 +/- 0.000004 days for HD 120198, 3.9974 +/- 0.0001days for HD 171263, and 9.487792 +/- 0.00005 days for HD 215441 are refinements of the best determinations in the literature.

Adelman, Saul J.; Dukes, Robert J.

2014-06-01

160

RaPToRS Sample Delivery System  

NASA Astrophysics Data System (ADS)

At various labs (NIF, LLE, NRL), activated material samples are used to measure reaction properties. The Rapid Pneumatic Transport of Radioactive Samples (RaPToRS) system quickly and safely moves these radioactive samples through a closed PVC tube via airflow. The carrier travels from the reaction chamber to the control and analysis station, pneumatically braking at the outlet. A reversible multiplexer routes samples from various locations near the shot chamber to the analysis station. Also, the multiplexer allows users to remotely load unactivated samples without manually approaching the reaction chamber. All elements of the system (pneumatic drivers, flow control valves, optical position sensors, multiplexers, Geiger counters, and release gates at the analysis station) can be controlled manually or automatically using a custom LabVIEW interface. A prototype is currently operating at NRL in Washington DC. Prospective facilities for Raptors systems include LLE and NIF.

Henchen, Robert; Shibata, Kye; Krieger, Michael; Pogozelski, Edward; Padalino, Stephen; Glebov, Vladimir; Sangster, Craig

2010-11-01

161

A genome-wide survey of RS domain proteins.  

PubMed

Domains rich in alternating arginine and serine residues (RS domains) are frequently found in metazoan proteins involved in pre-mRNA splicing. The RS domains of splicing factors associate with each other and are important for the formation of protein-protein interactions required for both constitutive and regulated splicing. The prevalence of the RS domain in splicing factors suggests that it might serve as a useful signature for the identification of new proteins that function in pre-mRNA processing, although it remains to be determined whether RS domains also participate in other cellular functions. Using database search and sequence clustering methods, we have identified and categorized RS domain proteins encoded within the entire genomes of Homo sapiens, Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae. This genome-wide survey revealed a surprising complexity of RS domain proteins in metazoans with functions associated with chromatin structure, transcription by RNA polymerase II, cell cycle, and cell structure, as well as pre-mRNA processing. Also identified were RS domain proteins in S. cerevisiae with functions associated with cell structure, osmotic regulation, and cell cycle progression. The results thus demonstrate an effective strategy for the genomic mining of RS domain proteins. The identification of many new proteins using this strategy has provided a database of factors that are candidates for forming RS domain-mediated interactions associated with different steps in pre-mRNA processing, in addition to other cellular functions. PMID:11780626

Boucher, L; Ouzounis, C A; Enright, A J; Blencowe, B J

2001-12-01

162

40 CFR 180.545 - Prallethrin (RS)-2-methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate...  

Code of Federal Regulations, 2010 CFR

...2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate as follows:...

2009-07-01

163

40 CFR 180.545 - Prallethrin (RS)-2-methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate...  

Code of Federal Regulations, 2013 CFR

...2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate as follows:...

2013-07-01

164

40 CFR 180.545 - Prallethrin (RS)-2-methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate...  

Code of Federal Regulations, 2010 CFR

...2-propynyl)cyclopent-2-enyl (1RS)-cis, trans-chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate; tolerances for residues...cyclopent-2-enyl (1RS )-cis, trans -chrysanthemate as follows:...

2010-07-01

165

Diamonds in the Rough: A Cautionary Tale of C/O Ratios in Exoplanet Host Stars  

NASA Astrophysics Data System (ADS)

It is currently unknown how/to what extent the chemical compositions of planetary atmospheres correlate with those of their host stars and if different host star compositions influence planet occurrence. The carbon-to-oxygen abundance ratio is one crucial measurement that may be used to better understand a possible connection between star and planet compositions. In gas giant atmospheres, the C/O ratio indicates the abundances of the primary O and C species, which, along with N species, regulate the climates of Solar System planets. The composition of a planetary atmosphere affects its temperature and chemistry, and therefore its observable signatures. The C/O ratio also establishes interior mineralogy - i.e., whether the planet is Si- or C-rich. Currently C and O are the only elements that can potentially be measured in both star and exoplanet atmospheres. Large samples of planet and host star C/O measurements may reveal trends indicative of processes in the protoplanetary disk or planetary interior that shift the planet's elemental composition away from the star's. However, estimating C/O ratios in transiting exoplanet atmospheres is mostly still based on only a few photometric observations. Moreover, even with high resolution, high S/N spectra, determinations of the stellar C/O ratios can be challenging. There are only a few O abundance indicators available at optical wavelengths and they are weak, blended with other atomic/molecular lines, and/or subject to non-LTE effects. I will present a methodologically consistent sample of C/O ratios measured from high-resolution spectra of transiting exoplanet host stars from several different C and O abundance indicators, using classical stellar abundance analysis techniques (including differential, line-by-line analysis w.r.t. the Sun). I will discuss the difficulties of host star abundance measurements, and what insights into planet formation and composition are possible from such analyses. I will highlight the case of 55 Cnc, a cool and metal-rich star whose O abundance measurements are even more challenging. Our results indicate that this star is not C-rich, as previously suggested, which impacts the proposal that the super-Earth 55 Cnc e is a “diamond” planet.

Teske, Johanna K.; Cunha, K. M.; Schuler, S. C.; Griffith, C. A.; Smith, V. V.

2014-01-01

166

Catalogue of Main Characteristics of Individual Pulsational Cycles of 35 Mira-Type Stars  

NASA Astrophysics Data System (ADS)

The characteristics of individual cycles of 35 Mira-type stars are tabulated: the moments and brightness of the extrema, the inverse slopes dt/dm of the light curves and corresponding error estimates. The observations for the analysis are taken from the AFOEV and VSOLJ databases for the stars: R And, W And, R Aql, R Aur, X Aur, R Boo, T Cam, U Cmi, R Cas, S Cas, T Cas, V Cas, W Cas, S Cep, T Cep, V Cnc, V Crb, ? Cyg, RT Cyg, W Dra, T Gem, U Her, R Hya, R Leo, R LMi, R Lep, R Lyn, W Lyr, X Oph, W Peg, Y Per, R UMa, S UMa, S UMi, T UMi.

Marsakova, V. I.; Andronov, I. L.

167

Coordinated ultraviolet and radio observations of selected nearby stars  

NASA Technical Reports Server (NTRS)

All of the US2 shifts assigned were successfully completed with simultaneous International Ultraviolet Explorer (IUE) and the Very Large Array (VLA) observations of the proposed target stars. The target stars included dwarf M flare stars and RS CVn stars. The combined ultraviolet (IUE) and microwave (VLA) observations have provided important new insights to the radiation mechanisms at these two widely-separated regions of the electromagnetic spectrum. The VLA results included the discovery of narrow-band microwave radiation and rapid time variations in the microwave radiation of dwarf M flare stars. The results indicate that conventional radiation mechanisms cannot explain the microwave emission from these stars. In general, ultraviolet variations and bursts occur when no similar variations are detected at microwave wavelengths and vice versa. Although these is some overlap, the variations in these two spectral regions are usually uncorrelated, suggesting that there is little interaction between the activity centers at the two associated atmospheric levels.

Lang, Kenneth R.

1987-01-01

168

RS3PE revealing recurrent non-Hodgkin's lymphoma.  

PubMed

A patient meeting published criteria for remitting seronegative symmetrical synovitis with pitting edema (RS3PE) was found to have a synchronous recurrence of non-Hodgkin's malignant lymphoma. Reported cases of RS3PE associated with hematological malignancies and other forms of cancer are reviewed. PMID:15474395

Gisserot, Olivier; Crémades, Serge; Landais, Cécile; Leyral, Guénaelle; Bernard, Philippe; de Jauréguiberry, Jean-Pierre

2004-09-01

169

RS3PE revealing recurrent non-Hodgkin’s lymphoma  

Microsoft Academic Search

A patient meeting published criteria for remitting seronegative symmetrical synovitis with pitting edema (RS3PE) was found to have a synchronous recurrence of non-Hodgkin’s malignant lymphoma. Reported cases of RS3PE associated with hematological malignancies and other forms of cancer are reviewed.

Olivier Gisserot; Serge Crémades; Cécile Landais; Guénaelle Leyral; Philippe Bernard; Jean-Pierre de Jauréguiberry

2004-01-01

170

Implementing the 3Rs in neuroscience research: a reasoned approach.  

PubMed

The 3Rs--replacement, reduction, and refinement--are aimed at minimizing the welfare costs to animals used in research. Some neuroscientists fear that implementing the 3Rs will prohibit essential studies. Others view them as fundamental ethical principles that improve the quality of research. A regulatory system that integrates science and welfare is most likely to deliver public confidence. PMID:22998864

Blakemore, Colin; MaCarthur Clark, Judy; Nevalainen, Timo; Oberdorfer, Michael; Sussman, Arthur

2012-09-20

171

Configuration control plan for the ports NCS IBM RS/6000  

SciTech Connect

This document describes the actions and responsibilities for maintaining the quality and integrity of the NS software resident on the IBM RS/6000 workstation managed by the Nuclear Criticality Safety group at the Portsmouth Gaseous Diffusion Plant. This document does not address the validation of NS software packages for the RS/6000.

Brown, A.S.

1996-07-01

172

Design and Implementation of a Fiber Optic RS232 Link.  

National Technical Information Service (NTIS)

This thesis investigates the feasibility of using a bi-directional fiber optic link to implement a RS232 data link. The results showed that a fiber optic link is a viable replacement. It offers a bandwidth up to 5 MHz, 250 times that of a RS232 data link....

J. W. Ryan

1987-01-01

173

Fast decoding of a d(min) = 6 RS code  

NASA Technical Reports Server (NTRS)

A method for high speed decoding a d sub min = 6 Reed-Solomon (RS) code is presented. Properties of the two byte error correcting and three byte error detecting RS code are discussed. Decoding using a quadratic equation is shown. Theorems and concomitant proofs are included to substantiate this decoding method.

Deng, H.; Costello, D. J., Jr.

1983-01-01

174

Metallicity and effective temperature of the secondary of RS Ophiuchi  

Microsoft Academic Search

Context: The recurrent nova RS Ophiuchi undergoes nova eruptions every ~10-20 years as a result of thermonuclear runaway on the surface of a white dwarf close to the Chandrasekhar limit. Both the progress of the eruption and its aftermath depend on the (poorly known) composition of the red giant in the RS Oph system. Aims: Our aim is to understand

Ya. V. Pavlenko; A. Evans; T. Kerr; L. Yakovina; C. E. Woodward; D. Lynch; R. Rudy; R. L. Pearson; R. W. Russell

2008-01-01

175

Neutron stars  

NASA Astrophysics Data System (ADS)

Neutron stars are laboratories for dense matter and gravitational physics. Observations of neutron stars from sources such as radio pulsars, low-mass X-ray binaries, X-ray bursts and thermally-emitting neutron stars are setting bounds to neutron star masses, radii, rotation rates, temperatures and ages. Mass measurements constrain the equation of state at the highest densities and set firm bounds to the highest possible density of cold matter. Radii constrain the equation of state in the vicinity of the nuclear saturation density and yield information about the density dependence of the nuclear symmetry energy. Laboratory measurements and theoretical studies of pure neutron matter are in remarkable agreement with observational bounds.

Lattimer, James M.

2014-05-01

176

Symbiotic stars  

NASA Technical Reports Server (NTRS)

The physical characteristics of symbiotic star systems are discussed, based on a review of recent observational data. A model of a symbiotic star system is presented which illustrates how a cool red-giant star is embedded in a nebula whose atoms are ionized by the energetic radiation from its hot compact companion. UV outbursts from symbiotic systems are explained by two principal models: an accretion-disk-outburst model which describes how material expelled from the tenuous envelope of the red giant forms an inwardly-spiralling disk around the hot companion, and a thermonuclear-outburst model in which the companion is specifically a white dwarf which superheats the material expelled from the red giant to the point where thermonuclear reactions occur and radiation is emitted. It is suspected that the evolutionary course of binary systems is predetermined by the initial mass and angular momentum of the gas cloud within which binary stars are born. Since red giants and Mira variables are thought to be stars with a mass of one or two solar mass, it is believed that the original cloud from which a symbiotic system is formed can consist of no more than a few solar masses of gas.

Kafatos, M.; Michalitsianos, A. G.

1984-01-01

177

RS-Predictor models augmented with SMARTCyp reactivities: Robust metabolic regioselectivity predictions for nine CYP isozymes  

PubMed Central

RS-Predictor is a tool for creating pathway-independent, isozyme-specific site of metabolism (SOM) prediction models using any set of known cytochrome P450 substrates and metabolites. Until now, the RS-Predictor method was only trained and validated on CYP 3A4 data, but in the present study we report on the versatility the RS-Predictor modeling paradigm by creating and testing regioselectivity models for substrates of the nine most important CYP isozymes. Through curation of source literature, we have assembled 680 substrates distributed among CYPs 1A2, 2A6, 2B6, 2C19, 2C8, 2C9, 2D6, 2E1 and 3A4, which we believe is the largest publicly accessible collection of P450 ligands and metabolites ever released. A comprehensive investigation into the importance of different descriptor classes for predicting the regioselectivity of each isozyme is made through the generation of multiple independent RS-Predictor models for each set of isozyme substrates. Two of these models include a DFT reactivity descriptor derived from SMARTCyp. Optimal combinations of RS-Predictor and SMARTCyp are shown to have stronger performance than either method alone, while also exceeding the accuracy of the commercial regioselectivity prediction methods distributed by StarDrop and Schrödinger, correctly identifying a large proportion of the metabolites in each substrate set within the top two rank-positions: 1A2(83.0%), 2A6(85.7%), 2B6(82.1%), 2C19(86.2%), 2C8(83.8%), 2C9(84.5%), 2D6(85.9%), 2E1(82.8%), 3A4(82.3%) and merged(86.0%). Comprehensive datamining of each substrate set and careful statistical analyses of the predictions made by the different models revealed new insights into molecular features that control metabolic regioselectivity and enable accurate prospective prediction of likely SOMs.

Zaretzki, Jed; Rydberg, Patrik; Bergeron, Charles; Bennett, Kristin P.; Olsen, Lars

2012-01-01

178

RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program, specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. MSFC is working closely with the USAF to obtain RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. As originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed.

Esther, Elizabeth A.; Kos, Larry; Burnside, Christopher G.; Bruno, Cy

2013-01-01

179

Design and implementation of a fiber optic RS232 link  

NASA Astrophysics Data System (ADS)

This thesis investigates the feasibility of using a bi-directional fiber optic link to implement a RS232 data link. The results showed that a fiber optic link is a viable replacement. It offers a bandwidth up to 5 MHz, 250 times that of a RS232 data link. This fiber optic link was tested over a distance of 1.5 kilometers, nearly 100 times that of the present RS232 link. It also offers the benefits of space and weight savings and is comparable to devices produced commercially but at a substantial cost savings.

Ryan, James W.

1987-09-01

180

RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the decommissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed

Esther, Elizabeth A.; Kos, Larry; Bruno, Cy

2012-01-01

181

MAPT rs242562 and GSK3B rs334558 are associated with Parkinson's Disease in central China  

PubMed Central

Background Microtubule-associated protein tau (MAPT) is a neuronal protein involved in the pathogenesis of several neurodegenerative diseases including Parkinson’s Disease (PD). Glycogen synthase kinase 3 beta (GSK3B) catalyzes phosphorylation in multiple sites of tau protein. However, whether or not there is any association between the GSK3B gene alteration, MAPT haplotype and PD remains unexplored in Chinese population, especially in central Chinese population. Results Here, we aimed at studying the effect of MAPT rs242562 and GSK3B rs334558 on the risk of PD by performing a case-control association study in central China. Our data showed that all PD patients and controls were of MAPT H1/H1 diplotype in our study, thus confirming that the distribution of the MAPT H1 haplotype is common in China. GG genotype of MAPT rs242562 serves protection effect on PD risk in central Chinese population, while genotype of GSK3B rs334558 showed no difference between PD patients and controls. Conclusions We conclude that the MAPT rs242562 is associated with PD in central China in the background of MAPT H1/H1 diplotype. The GG genotype of rs242562 displays protection against PD in subgroup with GSK3B rs334558 T carrier.

2014-01-01

182

Chameleon stars  

SciTech Connect

We consider a gravitating spherically symmetric configuration consisting of a scalar field nonminimally coupled to ordinary matter in the form of a perfect fluid. For this system we find static, regular, asymptotically flat solutions for both relativistic and nonrelativistic cases. It is shown that the presence of the nonminimal interaction leads to substantial changes both in the radial matter distribution of the star and in the star's total mass. A simple stability test indicates that, for the choice of parameters used in the paper, the solutions are unstable.

Dzhunushaliev, Vladimir [Institute for Basic Research, Eurasian National University, Astana, 010008 (Kazakhstan); Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic, 265 a, Chui Street, Bishkek, 720071 (Kyrgyzstan); Folomeev, Vladimir [Institute of Physicotechnical Problems and Material Science of the NAS of the Kyrgyz Republic, 265 a, Chui Street, Bishkek, 720071 (Kyrgyzstan); Singleton, Douglas [Institute for Basic Research, Eurasian National University, Astana, 010008 (Kazakhstan); Physics Department, CSU Fresno, Fresno, California 93740-8031 (United States)

2011-10-15

183

Catalogue of hemispheric sunspot numbers RN and RS: 1975 - 2000  

NASA Astrophysics Data System (ADS)

Sunspot drawings are provided on a regular basis at the Kanzelhöhe Solar Obseratory, Austria, and the derived relative sunspot numbers are reported to the Sunspot Index Data Center in Brussels. From the daily sunspot drawings, we derived the northern, Rn, and southern, Rs, relative sunspot numbers for the time span 1975-2000. In order to accord with the International Sunspot Numbers Ri, the Rn and Rs have been normalized to the Ri, which ensures that the relation Rn+Rs = Ri is complied. For validation, the derived Rn and Rs are compared to the international northern and southern relative sunspot numbers, which are available since 1992. The regression analysis performed for the period 1992-2000 reveals good agreement with the International hemispheric Sunspot Numbers. The monthly mean and the smoothed monthly mean hemispheric Sunspot Numbers are compiled to a catalogue. In addition, the daily hemispheric Sunspot Numbers are made available via Internet.

Temmer, M.; Veronig, A.; Hanslmeier, A.

2002-12-01

184

Schools Add More Fruits, Veggies to the '3 Rs'  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Schools Add More Fruits, Veggies to the '3 Rs' ... March 4, 2014 Related MedlinePlus Pages Child Nutrition School Health TUESDAY, March 4 (HealthDay News) -- Under new ...

185

Animal welfare and the 3Rs in European biomedical research.  

PubMed

The new Directive 2010/63/EU to ensure harmonization of animal experimentation rules has potential to increase implementation of the 3Rs (reduce, refine, replace) and improve animal welfare across Europe. PMID:22211967

Wells, Dominic J

2011-12-01

186

AirMSPI SEAC4RS Ellipsoid Data  

... AirMSPI SEAC4RS Ellipsoid-projected Georegistered Radiance Data AirMSPI Ellipsoid-Projected Georegistered Radiance Product ... Polarized Radiance DOLP AOLP Order Data:  Reverb:  Order Data SCAR-B Block:  ...

2014-04-14

187

What kind of animal is the "Three Rs"?  

PubMed

Fifty years after the publication of The Principles of Humane Experimental Technique by Russell and Burch, this paper explores the contemporary role of the Three Rs. This is illustrated by reference to a recent social scientific study, which involved a total of 50 in-depth interviews with scientists who use animals and with other stakeholders in the debate. The data analysis shows how the Three Rs are conceptualised in at least three ways: firstly, as an ethical animal, either as a shorthand for a moral imperative, or as a route to managing an ethical dilemma; secondly, as a scientific animal, internal to the scientific method; and finally, as a political animal, with some stakeholders referring to the Three Rs as a way to promote consensus in a controversial domain. Pushing the metaphor a little further, the paper concludes that the Three Rs concept has become a kind of hybrid animal. PMID:20105021

Hobson-West, Pru

2009-12-01

188

AirMSPI SEAC4RS Terrain Data  

... AirMSPI SEAC4RS Terrain-projected Georegistered Radiance Data AirMSPI Terrain-Projected Georegistered Radiance Product ... Polarized Radiance DOLP AOLP Order Data:  Reverb:  Order Data Read Software Files :  ...

2014-05-05

189

The 1985 outburst of RS Ophiuchi: Spectroscopic results  

Microsoft Academic Search

Optical spectroscopic data on the recurrent nova RS Ophiuchi obtained between 32 and 108 days after its last outburst on 1985\\u000a January 27 are presented. RS Oph was in the coronal-line phase at that time. The widths of the permitted as well as coronal-lines\\u000a decreased continuously. Assuming that the ejected envelope decelerated due to its interaction with circum stellar matter,

G. C. Anupama; T. P. Prabhu

1989-01-01

190

UBVRI observations of the flickering of RS Ophiuchi at quiescence  

Microsoft Academic Search

We report observations of the flickering variability of the recurrent nova RS Oph at quiescence on the basis of simultaneous observations in five bands (UBVRI). RS Oph has a flickering source with (U - B)0 = -0.62 +\\/- 0.07, (B - V)0 = 0.15 +\\/- 0.10 and (V - R)0 = 0.25 +\\/- 0.05. We find for the flickering source

R. K. Zamanov; S. Boeva; R. Bachev; M. F. Bode; D. Dimitrov; K. A. Stoyanov; A. Gomboc; S. V. Tsvetkova; L. Slavcheva-Mihova; B. Spasov; K. Koleva; B. Mihov

2010-01-01

191

Design and implementation of a fiber optic RS232 link  

Microsoft Academic Search

This thesis investigates the feasibility of using a bi-directional fiber optic link to implement a RS232 data link. The results showed that a fiber optic link is a viable replacement. It offers a bandwidth up to 5 MHz, 250 times that of a RS232 data link. This fiber optic link was tested over a distance of 1.5 kilometers, nearly 100

James W. Ryan

1987-01-01

192

Open communication for drives having a conventional RS232 interface  

Microsoft Academic Search

In industrial plants, more and more devices having only a usual RS232 interface must communicate and be networked through an open fieldbus system. Fast communications on large areas are required especially for open-loop and closed-loop control of electric drives. This paper presents a solution that enables to couple devices with RS232 port as slaves to a PROFIBUS network. An industrial

G. Weiner; S. Gyarmathy; J. Marko

1993-01-01

193

Liquid Rocket Propulsion: RS-68 and Linear Aerospike  

NASA Technical Reports Server (NTRS)

This paper presents viewgraphs of the RS-68 and Linear Aerospike engines. The topics include: 1) The mission; 2) Design and Development Strategies; 3) Cost Driven Design Trades; 4) Moderate Pressure Requirements Enable Reduced Complexity; 5) Experience Based Design; 6) Development Costs Dominated by Cost of Eliminating Failure Modes; and 7) Reducing Development Costs. This paper also includes the design of the RS-68 Engine and the engine performance.

Murphy, Terry

1999-01-01

194

Association of rs1568885, rs1813443 and rs4411591 polymorphisms with anti-TNF medication response in Greek patients with Crohn's disease  

PubMed Central

AIM: To investigate the correlation between rs1568885, rs1813443 and rs4411591 polymorphisms and response to infliximab in a cohort of Greek patients with Crohn’s disease (CD). METHODS: One hundred and twenty-six patients diagnosed with CD based on standard clinical, endoscopic, radiological, and pathological criteria were enrolled in this study at the Gastroenterology Unit of the 2nd Department of Surgery and at the Colorectal Unit of the 1st Department of Propaedeutic Surgery. Infliximab at a dose of 5 mg/kg was administered intravenously at weeks 0, 2, 6 and then every 8 wk. Clinical and serological responses were assessed using the Harvey-Bradshaw Index and serum C-reactive protein (CRP) levels, respectively, and the endoscopic response was evaluated by ileocolonoscopy performed at baseline and after 12-20 wk of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Genomic DNA from whole peripheral blood was extracted and genotyping was performed by allele-specific polymerase chain reactions. ?2 test with Yate’s correction based on the S-Plus was used to compare the genotype frequencies. RESULTS: Eighty patients (63.49%) were classified as complete and 32 (25.39%) as partial responders to infliximab, while 14 (11.11%) were primary non-responders. No correlation was found between response to infliximab and patients’ characteristics such as age, gender and disease duration. There was consistency between Harvey-Bradshaw index scores and serum CRP levels. The TT genotype of the rs1568885 polymorphism was significantly related to partial response (P = 0.024) and resistance to infliximab (P = 0.007) while the AT genotype was more frequent in partial responders (P = 0.035) and in primary non-responders (P = 0.032). Regarding rs1813443, the CC genotype was found to be associated with partial response (P = 0.005) and primary resistance (P = 0.002) to infliximab while no association was found between the rs4411591 polymorphism and the clinical response to infliximab. CONCLUSION: Based on our results, the rs1568885 and rs1813443 polymorphisms are associated with clinical and biochemical response to infliximab in Greek patients with Crohn’s disease.

Thomas, Diamantis; Gazouli, Maria; Karantanos, Theodoros; Rigoglou, Stella; Karamanolis, Georgios; Bramis, Konstantinos; Zografos, George; Theodoropoulos, George E

2014-01-01

195

Brittle Star  

USGS Multimedia Gallery

A tiny brittle star (the central disc is smaller than a dime) clings to the branches of a soft coral in a sample bucket brought into the shipboard laboratory from a submersible dive. This creature makes its home on the deep, dark ocean floor. ...

2010-04-15

196

Human mitochondrial TyrRS disobeys the tyrosine identity rules  

PubMed Central

Human tyrosyl-tRNA synthetase from mitochondria (mt-TyrRS) presents dual sequence features characteristic of eubacterial and archaeal TyrRSs, especially in the region containing amino acids recognizing the N1-N72 tyrosine identity pair. This would imply that human mt-TyrRS has lost the capacity to discriminate between the G1-C72 pair typical of eubacterial and mitochondrial tRNATyr and the reverse pair C1-G72 present in archaeal and eukaryal tRNATyr. This expectation was verified by a functional analysis of wild-type or mutated tRNATyr molecules, showing that mt-TyrRS aminoacylates with similar catalytic efficiency its cognate tRNATyr with G1-C72 and its mutated version with C1-G72. This provides the first example of a TyrRS lacking specificity toward N1-N72 and thus of a TyrRS disobeying the identity rules. Sequence comparisons of mt-TyrRSs across phylogeny suggest that the functional behavior of the human mt-TyrRS is conserved among all vertebrate mt-TyrRSs.

BONNEFOND, LUC; FRUGIER, MAGALI; GIEGE, RICHARD; RUDINGER-THIRION, JOELLE

2005-01-01

197

The optical counterpart of the X-ray source H0253+193 - A distant, high-luminosity RS Canum Venaticorum system  

NASA Technical Reports Server (NTRS)

Optical and near-infrared photometry in the VRIJHK and CO (2.35 microns) bands and optical spectroscopy and polarimetry reveal that the optical counterpart of the X-ray source H0253+193 is most likely a RS CVn binary system. The results show a visual extinction of 11.3 mag to the star, with an IR excess possibly due a cooler binary companion or circumstellar material. It is suggested that the I-band polarization of 8.1 + or - 1.8 may be induced in the starlight by passage through the molecular cloud. The lack of strong H-alpha emission in the optical spectrum argues against the possibility of a classical T Tauri star, and the IR excess argues against a naked T Tauri star. The wide energy spectrum found in the dereddened optical and near-infrared photometry supports the binary star model.

Clemens, Dan P.; Leah, Robert W.

1989-01-01

198

Interface Conversion Design Based on FPGA-Soft-Macro for EnDat2.2 and RS232\\/RS485  

Microsoft Academic Search

The EnDat2.2 interface protocol developed by HEIDENHAIN company lately with its high-speed, bi-directional and pure digital features can meet the requirement of rapid responses, dramatically cut down the overall system's cost and greatly reduce the space requirements of the system's installation. Therefore, it is widely used in Numerical control system like CNC system and photoelectric encoder. China's first Micro-area X-ray

Yang Jian; Wang Hanbin; Yao Xangqian; Wan Sanghong

2010-01-01

199

Spectroscopy: Star Light, Star Bright  

NSDL National Science Digital Library

This is a student reading about the different types of spectra: continuous, absorption, and emission. Learners will read about the differences between each and see graphical representations of each. This activity is from the Stanford Solar Center's All About the Sun: Sun and Stars activity guide for Grades 5-8 and can also accompany the Stanford Solar Center's Build Your Own Spectroscope activity.

200

Converting neutron stars into strange stars  

NASA Technical Reports Server (NTRS)

If strange matter is formed in the interior of a neutron star, it will convert the entire neutron star into a strange star. The proposed mechanisms are reviewed for strange matter seeding and the possible strange matter contamination of neutron star progenitors. The conversion process that follows seeding and the recent calculations of the conversion timescale are discussed.

Olinto, A. V.

1991-01-01

201

Microwave observations of late-type stars with the Very Large Array  

NASA Technical Reports Server (NTRS)

The Very Large Array was used to search for microwave emission from 32 stars of late spectral type including RS CVn type stars, dwarf M stars, and stars with active chromospheres, coronae, or intense magnetic fields. The RS CVn stars were detected at 6 cm wavelength, and upper limits are established for another six. Radio emission was detected from three dwarf M flare stars, UV Cet, EQ Peg and YZ CMi. Both impulsive (no more than 20 s) and more gradual (at least ten minutes) bursts were observed from the flare star YZ CMi. Radio emission was not confirmed at 6 cm from the solar type star Chi(1) Ori, with an upper limit that is three times lower than the detections reported by other observers. Microwave emission could not be detected from any other solar type star of spectral class F to K. The quiescent radio emission from dwarf M flare stars was interpreted as nonthermal gyrosynchrotron emission by mildly relativistic electrons accelerated more or less continuously in the magnetic fields of starspots.

Pallavicini, R.; Willson, R. F.; Lang, K. R.

1985-01-01

202

3D simulations of RS Ophiuchi: from accretion to nova blast  

NASA Astrophysics Data System (ADS)

Context: The binary star system RS Ophiuchi is a recurrent nova, with outbursts occurring about every 22 years. It consists of a red giant star (RG) and a wind accreting white dwarf close to the Chandrasekhar limit. This system is considered a prime candidate for evolving into an SNIa. For its most recent outbursts in 1985 and 2006, exquisite multiwavelength observational data are available. Aims: Deeper physical insight is needed regarding the inter-outburst accretion phase and the dynamical effects of the subsequent nova explosion in order to improve the interpretation of the observed data and to shed light on whether the system is an SNIa progenitor. Methods: We present a 3D hydrodynamic simulation of the quiescent accretion with the subsequent explosive phase. Results: The computed circumstellar mass distribution in the quiescent phase is highly structured with a mass enhancement in the orbital plane of about a factor of 2 as compared to the poleward directions. The simulated nova remnant evolves aspherically, propagating faster toward the poles. The shock velocities derived from the simulations agree with those derived from observations. For v_RG = 20 km s-1 and for nearly isothermal flows, we find that 10% of the mass lost by the RG is transfered to the WD. For an RG mass loss of 10-7~M? yr-1, the orbit of the system decays by 3% per million years. With the derived mass transfer rate, multi-cycle nova models provide a qualitatively correct recurrence time, amplitude, and fastness of the nova. Conclusions: Our 3D hydrodynamic simulations provide, along with the observations and nova models, the third ingredient for a deeper understanding of the recurrent novae of the RS Oph type. In combination with recent multi-cycle nova models, our results suggest that the WD in RS Oph will increase in mass. Several speculative outcomes then seem plausible. The WD may reach the Chandrasekhar limit and explode as an SN Ia. Alternatively, the mass loss of the RG could result in a smaller Roch volume, a common envelope phase, and a narrow WD + WD system. Angular momentum loss due to gravitational wave emission could trigger the merger of the two WDs and - perhaps - an SN Ia via the double degenerate scenario. In the frame of the computing project “Cosmic Engines in Galaxies”. The movie is only available in electronic form at http://www.aanda.org

Walder, R.; Folini, D.; Shore, S. N.

2008-06-01

203

Early Evolution Of The 2006 Eruption Of The Recurrent Novae RS Oph  

NASA Astrophysics Data System (ADS)

Classical novae occur frequently, but repeated outbursts of a KNOWN nova occurs rarely. These observed repeated outbursts render recurrent novae (RN) unique amongst all novae, and important astrophysical laboratories in which to study the outburst physics and chemical processing that occurs in novae (or at least this subclass). The primaries of RN are thought to be massive white dwarfs (1.3-1.4 solar masses, close to the Chandrasekhar limit). Consequently, their outbursts are quite brief, returning back to their quiescent state within just a few months. If the white dwarf (WD) retains a net gain in mass after each accretion-eruption cycle, this could eventually result in a Type Ia supernovae explosion. RS Oph is one of only a few known recurrent novae, itself having been observed to erupt in 1898, 1933, 1958, 1967, and 1985; roughly once a generation! RS Oph is further unique in that the secondary is a late-type ~M2III giant star in a long-period orbit of ~460 days. Thus, the hot WD is enshrouded within the extended wind of the giant companion. On 2006 February 12, RS Oph experienced yet another eruption, rising by about 6 mags to V~5. A high-dispersion spectroscopic campaign was initiated on RS Oph using the APO 3.5m telescope using the echelle spectrograph (R~37,500, continuous coverage from 0.35nm to 0.98nm, ~25 nights) complimented by lower-dispersion spectra obtained on the SMARTS 1.5m telescope at CTIO, and coordinated with various campaigns conducted with space observatories. We report initial results from the spectroscopic ground-based campaign, and compare with results found during previous eruptions. Though the 2006 eruption behaved qualitatively similar to the 1985 outburst, important differences are observed. For example, the 2006 eruption proceeded more rapidly than the 1985 outburst, likely a result of a larger envelope mass accreted before the thermonuclear runaway ensured. Broad hydrogen lines narrowed as the eruption evolved, while He I lines disappeared, replaced by He II lines as the ejecta became shock heated. Details of the evolving ionization state, kinematics, and equivalent widths will be discussed.

Stringfellow, G. S.; Walter, F. M.; Wallerstein, G.; York, D. G.; Dembicky, J.; Ketzebach, B.; McMillan, R. J.

2007-08-01

204

Magnetic Inhibition of Convection and the Fundamental Properties of Low-mass Stars. I. Stars with a Radiative Core  

NASA Astrophysics Data System (ADS)

Magnetic fields are hypothesized to inflate the radii of low-mass stars—defined as less massive than 0.8 M ?—in detached eclipsing binaries (DEBs). We investigate this hypothesis using the recently introduced magnetic Dartmouth stellar evolution code. In particular, we focus on stars thought to have a radiative core and convective outer envelope by studying in detail three individual DEBs: UV Psc, YY Gem, and CU Cnc. Our results suggest that the stabilization of thermal convection by a magnetic field is a plausible explanation for the observed model-radius discrepancies. However, surface magnetic field strengths required by the models are significantly stronger than those estimated from observed coronal X-ray emission. Agreement between model predicted surface magnetic field strengths and those inferred from X-ray observations can be found by assuming that the magnetic field sources its energy from convection. This approach makes the transport of heat by convection less efficient and is akin to reduced convective mixing length methods used in other studies. Predictions for the metallicity and magnetic field strengths of the aforementioned systems are reported. We also develop an expression relating a reduction in the convective mixing length to a magnetic field strength in units of the equipartition value. Our results are compared with those from previous investigations to incorporate magnetic fields to explain the low-mass DEB radius inflation. Finally, we explore how the effects of magnetic fields might affect mass determinations using asteroseismic data and the implication of magnetic fields on exoplanet studies.

Feiden, Gregory A.; Chaboyer, Brian

2013-12-01

205

Association between chemerin rs17173608 and vaspin rs2236242 gene polymorphisms and the metabolic syndrome, a preliminary report.  

PubMed

Metabolic syndrome (MeS) is associated with increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease. There is some evidence indicating that adipokines play a role in the development of MeS. The present study was aimed to investigate the impact of chemerin rs17173608 and vaspin rs2236242 gene polymorphisms with the risk of MeS in a sample of Iranian population. This case-control study was done on 151 subjects with MeS and 149 without MeS, as defined by NCEP-ATPIII. Tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) was designed to detect the polymorphisms. Our finding showed that there are significant differences in genotype frequencies between the groups regarding vaspin rs2236242 polymorphism (?(2)=18.74, p<0.0001). A significant protection against MeS was found for vaspin rs2236242 in allele and genotypes (Odd Ratio [OR]=0.52; 95% confidence interval [CI]=0.37-0.72; p=0.0001, T vs A; OR=0.49; 95%CI=0.29-0.82; p=0.007, TT vs TA and OR=0.17; 95%CI=0.07-0.40; p<0.0001, TT vs AA). Our finding showed positive association between chemerin rs17173608 polymorphism and risk of MeS (?(2)=7.70, p=0.021). The G allele increased the risk of MeS (OR=1.78; 95% CI=1.14-2.78; p=0.012) as compared to the T allele. In conclusion, our data suggest for the first time a significant association between vaspin rs2236242 and chemerin rs17173608 polymorphisms and the MeS in Zahedan, southeast Iran. Further studies with large sample size and different ethnicities are required to confirm our findings. PMID:22982016

Hashemi, Mohammad; Rezaei, Hamzeh; Eskandari-Nasab, Ebrahim; Kaykhaei, Mahmoud Ali; Zakeri, Zahra; Taheri, Mohsen

2012-12-01

206

Amyloid arthropathy revealed by RS3PE syndrome.  

PubMed

Amyloid arthropathy is a form of primary AL amyloidosis with a monoclonal component in the blood and/or urine, and RS3PE syndrome is acute edematous polysynovitis in subjects older than 60 years. A 74-year-old man was diagnosed with both disorders. He was admitted for benign acute polyarthritis of the hands and feet and reported carpal tunnel symptoms predominating on the right. A synovial biopsy at the right wrist disclosed deposits that stained with Congo red even after potassium permanganate treatment (positive Wright's test). Articular AL amyloidosis was diagnosed. The symptoms resolved under glucocorticoid therapy alone, casting some doubt on their relationship with the amyloidosis. Roentgenograms showed geodes, a feature not present in RS3PE. Whether RS3PE may be among the possible presentations of articular amyloidosis is discussed. PMID:11143918

Magy, N; Michel, F; Auge, B; Toussirot, E; Wendling, D

2000-01-01

207

The IUE-UV spectrum of the CP2 star HR465  

NASA Astrophysics Data System (ADS)

Consideration is given to eleven high resolution IUE spectra of the chemically peculiar star HR 465 obtained between 1979 and 1982. The spectra are compared to those of Pi Cet, Nu Cap, Vega, HD 101065, alpha exp 2 CVn, Kappa Cnc, HR 4072, and HR 7775. About 2500 lines are identified in the HR 465 spectra. Most of these lines belong to iron-peak elements, especially Fe II. The presence of other ions, including Ni II, Zn II, Ga II, Nb II, Eu II, and Eu III, is examined. It is shown that the rare-earth elements that are strong in the optical spectra of HR 465 are very weak, if present, in the IUE region. Lines of Pt II are found for HR 465. The results also suggest that Au II, Hg II, and Bi II are probably present.

Fuhrmann, K.

1989-11-01

208

Looking for Exoplanet Transits in Bright Stars with Small Field-of-View Detectors  

NASA Astrophysics Data System (ADS)

Differential photometry is a robust technique for ground-based observations of transits since it sorts out slow variations of sky transparency as well as other first order effects that are common to all stars in the field-of-view (FOV) of the imaging detector. To work properly, differential photometry has a few requirements like similar brightness of the target and reference stars, similar colours and a relative proximity in the plane of the sky to avoid sensitivity variations like those caused by vignetting in the FOV. It happens that for bright stars these conditions are hardly met. Typical CCDs in a ~60 cm class telescope give a FOV of ~10 arcmin and this is not enough to have in the same image frame suitable reference stars. Also, bright (V < 7) tend to saturate the detector for the shortest practical integration time. To minimize these problems, we tested an instrumental setup in which half of the detector is covered with a neutral density (D=2.3) filter. We report CCD observations on which we achieved milimagnitude precision for bright systems that are not known to show transits, like Tau Boo, 55 Cnc and HD 162020, as well as the well known case of HD 209458.

Martioli, Eder; Jablonski, Francisco

2007-08-01

209

Validation of Omron RS8, RS6, and RS3 home blood pressure monitoring devices, in accordance with the European Society of Hypertension International Protocol revision 2010  

PubMed Central

Background Allowing patients to measure their blood pressure at home is recognized as being of clinical value. However, it is not known how often these measurements are taken correctly. Blood pressure monitors for home use fall into two types based on the position of the cuff, ie, at the upper arm or the wrist. The latter is particularly convenient, as measurements can be taken fully clothed. This study aimed to evaluate the performance of the wrist-type blood pressure monitors Omron RS8 (HEM-6310F-E), Omron RS6 (HEM-6221-E), and Omron RS3 (HEM-6130-E). Methods A team of three trained doctors validated the performance of these devices by comparing the measurements obtained from these devices with those taken using a standard mercury sphygmomanometer. All the devices met the validation requirements of the European Society of Hypertension International Protocol revision 2010. Results The difference in blood pressure readings between the tested device and the standard mercury sphygmomanometer was within 3 mmHg, which is acceptable according to the European Society of Hypertension guidelines. Conclusion All the home devices tested were found to be suitable for measuring blood pressure at home because their performance fulfilled the requirement of the guidelines.

Takahashi, Hakuo; Yoshika, Masamichi; Yokoi, Toyohiko

2013-01-01

210

Cool stars, stellar systems, and the sun; Proceedings of the 6th Cambridge Workshop, Seattle, WA, Sept. 18-21, 1989  

NASA Technical Reports Server (NTRS)

The present conference on cool stars, stellar systems, and the sun encompasses stellar chromospheres and coronae, binary stars, the stellar evolution of contracting stars and red giants, stellar evolution abundances of the elements, mass loss and envelopes, and stellar pulsation. Specific issues addressed include theories regarding the acoustic and magnetic heating of stellar chromospheres and coronae, stellar granulation, wave heating in magnetic flux tubes, observations of the solar Ca-II lines, longitudinal-transverse magnetic tube waves in the solar atmosphere, radio emission from rapidly rotating cool giant stars, and spot temperatures and area coverages on active dwarf stars. Also addressed are the optical and UV spectra of RS-CVn stars, emission lines from T-Tauri stars, the spectroscopy of HR1614 group stars, red giants in external galaxies, the rotation of evolved stars, the transition from red giant to planetary nebula, and radiative transfer in the dynamic atmospheres of variable stars.

Wallerstein, George (editor)

1990-01-01

211

DB Pulsating Stars  

NASA Astrophysics Data System (ADS)

Pulsating WHITE DWARF stars with nearly pure helium atmospheres exist in a narrow temperature range near 25 000 K. At this writing, there are eight of these stars known. Collectively, they go by two names: the V777 Her stars, named after the VARIABLE STAR designation of the first known star in the class, and the more informative name, the DBV stars. The name DBV follows the standard convention fo...

Winget, D.; Murdin, P.

2000-11-01

212

Physical parameters of seven field RR Lyrae Stars in bootes  

NASA Astrophysics Data System (ADS)

Strömgren uvby-? photometry is reported for the RR Lyrae stars AE, RS, ST, TV, TW, UU, and XX in Bootes. The physical parameters M/M_?, log(L/L_?), M_V, log T_{eff} and [Fe/H], have been estimated from the Fourier decomposition of the light curves and the empirical calibrations developed for this type of stars. The obtained [Fe/H] values are compared with those calculated from the ? S index for some sample stars. It was found that reddening in the zone is negligible compared to that shown by several objects in the same sky zone. From that, distance to the stars was calculated. The variation of the unreddened indexes (b-y)_0 and c_1 along the pulsational cycle allows the direct comparison with the theoretical grids and, hence, an independent determination of T_{eff} and log g.

Peña, J. H.; Arellano Ferro, A.; Peña Miller, R.; Sareyan, J. P.; Álvarez, M.

2009-10-01

213

MnSOD rs4880 and XPD rs13181 polymorphisms predict the survival of breast cancer patients treated with adjuvant tamoxifen.  

PubMed

Abstract The enzyme manganese superoxide dismutase (MnSOD) defends against oxidative stress caused by reactive oxygen species (ROS), whereas Xeroderma pigmentosum group D (XPD) protein is involved in DNA repair. Polymorphisms in these genes have previously been associated with the outcome of breast cancer. Material and methods. Two gene polymorphisms, the MnSOD Val16Ala (rs4880A> G) and the XPD Lys751Gln (rs13181A> C), were analyzed in a cohort of 396 Finnish breast cancer patients by using PCR-RFLP-based methods in a prospective case-control study. The overall survival (OS), breast cancer-specific survival (BCSS), and relapse-free survival (RFS), assessed by using Kaplan-Meier survival analysis and multivariate Cox regression analysis, were evaluated according to the adjuvant treatments and the rs4880 and rs13181 genotypes. Results. In the combined analysis of rs4880 and rs13181 genotypes for patients treated with adjuvant tamoxifen (TAM) an increasing number of low-risk genotypes (rs4880 AA, rs4880 AG, or rs13181 AA) was significantly associated with better RFS, BCSS, and OS (n = 64). In addition, there was improved BCSS and RFS among TAM-treated patients carrying the wild-type rs4880 A allele as compared with the other genotypes (n = 64). The wild-type rs13181 AA genotype was similarly associated with better RFS and BCSS in the TAM-treated population (n = 65). Conclusion. This is the first study to show that the MnSOD rs4880 and XPD rs13181 polymorphisms may influence the outcome of breast cancer patients receiving adjuvant TAM monotherapy. Patients carrying the rs4880 A allele or rs13181 AA genotype may have a reduced ability to scavenge ROS and repair the DNA damage generated by TAM treatment. PMID:24716840

Tengström, Maria; Mannermaa, Arto; Kosma, Veli-Matti; Soini, Ylermi; Hirvonen, Ari; Kataja, Vesa

2014-06-01

214

Principal Component Analysis in Grey Based Taguchi Method for Optimization of Multiple Surface Quality Characteristics of 6061-T4 Aluminum in CNC End Milling  

NASA Astrophysics Data System (ADS)

The present study highlights a multi-objective optimization problem by applying Principal Component Analysis (PCA) coupled with grey based Taguchi method through a case study in CNC end milling of 6061-T4 Aluminum. The study aimed at evaluating the best process environment which could simultaneously satisfy multiple requirements of surface quality. In view of the fact, that traditional Taguchi method cannot solve a multi-objective optimization problem; to overcome this limitation, grey relation theory has been coupled with Taguchi method. Furthermore, to follow the basic assumption of Taguchi method i.e. quality attributes should be uncorrelated or independent; which is not always satisfied in practical situation. To overcome this shortcoming the study applied Principal Component analysis to eliminate response correlation and to evaluate independent or uncorrelated quality indices called Principal Components which were aggregated to compute an overall quality index denoted as overall grey relational grade which was optimized (minimized) finally. The study combined PCA and grey based Taguchi method for predicting optimal setting. Optimal result was verified through confirmatory test.

Datta, Saurav; Routara, Bharat Chandra; Bandyopadhyay, Asish; Mahapatra, Siba Sankar

2011-01-01

215

TiO-band Study of Starspots on Pleiades G\\/K Stars  

Microsoft Academic Search

In several previous studies, we have used absorption bands of the titanium oxide (TiO) molecule to study starspot area and temperature on magnetically active stars, including RS CVn-type evolved systems and BY Dra-type dwarfs. These studies have concentrated on field stars, those bright enough to see with relatively small telescopes and echelle spectrographs -- thus no systematic study of the

Douglas B. O'Neal

2010-01-01

216

RS3PE syndrome: a clinical and immunogenetical study  

Microsoft Academic Search

This study analyses the clinical, radiological, evolutive, and immunogenetical characteristics of a series of patients diagnosed with remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome. Reviewed were the clinical charts and human leukocyte antigen (HLA) profiles of all patients treated at a single teaching hospital fulfilling the features of this syndrome according to the definition of McCarty. Twelve cases

Rubén Queiro

2004-01-01

217

Work in Progress: The Seven Rs of Team Building  

ERIC Educational Resources Information Center

This article argues that supportive teams--including professionals, paraprofessionals, and parents--can teach staff members how to identify and implement best practices in early intervention settings. The authors describe "the seven Rs of team building" distilled from their many years of team building and maintenance: 1) Reading cues; 2) Regular…

Brunelli, Jean; Schneider, Elaine Fogel

2004-01-01

218

Communicating with a Device using Linux and RS232  

Microsoft Academic Search

This document shows how to program Linux to communicate with a device using the RS- 232 protocol. It explains how to create the device driver, how to install it on a Linux operated computer and how to access the driver through a user-space program.

Thomas Wa-jiw Casey

219

Maximum transmission distance for RS232 computer cables  

Microsoft Academic Search

Results of a study to establish guidelines for maximum cable lengths in a variety of typical RS-232 applications are presented. Even when worst-case conditions and 20% safety factors are included, the study indicates that cable lengths can often be used which are much longer than those suggested by the EIA standard. Maximum utilization guidelines are recommended for all systems running

B. Carlson

1988-01-01

220

An Embedded Converter from RS232 to Universal Serial Bus  

Microsoft Academic Search

Abstract: Universal Serial Bus (USB) is a new personal computer interconnection protocol, developed to make the connection of peripheral devices to a computer easier and more efficient. It reduces the cost for the end-user, improves communication speed and supports simultaneous attachment of multiple devices (up to 127). RS232, in another hand, was designed to single device connection, but is one

Ana Luiza de Almeida Pereira Zuquim; Claudionor José Nunes Coelho Jr; Antônio Otávio Fernandes; Marcos Pêgo de Oliveira; Andréa Iabrudi Tavares

2001-01-01

221

The Designing of Serial Communication Based on RS232  

Microsoft Academic Search

This Paper discussed the principle of serial communication mainly, proposed the design method based on RS232, designed the hard circuit of serial communication, and realized the programming to PC Microcomputer and single chip microcomputer by using assembly language and C++ Builder separately.

Xinghai Han; Xiangxin Kong

2010-01-01

222

MaRS: Mars Express Orbiter Radio Science  

Microsoft Academic Search

The Mars Express Orbiter Radio Science (MaRS) experiment will employ radio occultation to (I) sound the neutral martian atmosphere to derive vertical density, pressure and temperature profiles as functions of height to resolutions better than 100 m, (II) sound the ionosphere to derive vertical ionospheric electron density profiles and a description of the ionosphere through its diurnal and seasonal variations

M. Pätzold; F. M. Neubauer; L. Carone; A. Hagermann; C. Stanzel; B. Häusler; S. Remus; J. Selle; D. Hagl; D. P. Hinson; R. A. Simpson; G. L. Tyler; S. W. Asmar; W. I. Axford; T. Hagfors; J.-P. Barriot; J.-C. Cerisier; T. Imamura; K.-I. Oyama; P. Janle; G. Kirchengast; V. Dehant

2004-01-01

223

The Semiregular Variable Star Observing Program at Grinnell College  

NASA Astrophysics Data System (ADS)

A large body of photometric and spectroscopic data on 38 semiregular variable stars has been acquired at the Grant O. Gale Observatory of Grinnell College since 1984. This includes V and B band photoelectric photometry, CCD spectroscopic monitoring, and a large set of spectra for RS Cygni. The stars in the program were selected because they had a history of “quiescent episodes” in their pulsations that might be explained as mode switches. Time-dependent Fourier analysis has been applied to the photometric data to reveal the dominant frequency components represented in the light curves and to investigate how the strengths of those components vary - sometimes quite abruptly - over time. The spectroscopic monitoring of the entire set of stars is an ongoing project. The 413 RS Cygni spectra have been used to explore the variation of spectral features with phase. The conspicuous dip near the peak of the RS Cygni light curve does not appear to be associated with obvious variations in the strengths of spectral features.

Cadmus, Robert R.

2014-06-01

224

Star Search  

NSDL National Science Digital Library

In this online activity, learners can test their skills at finding constellations in the northern hemisphere's night sky. Learners can choose during which season to look, and then look for four constellations in that season. The simulation shows a simple representation of the night sky with key stars highlighted. Use this as a practice before going outside or just to give learners an idea of the difficulties involved in identifying constellations. When learners set up a free account at Kinetic City, they can answer bonus questions at the end of the activity as a quick assessment. As a larger assessment, learners can complete the Smart Attack game after they've completed several activities.

Science, American A.

2009-01-01

225

O stars and Wolf-Rayet stars  

NASA Technical Reports Server (NTRS)

Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented.

Conti, Peter S.; Underhill, Anne B.; Jordan, Stuart (editor); Thomas, Richard (editor)

1988-01-01

226

Spatially extended emission around the Cepheid RS Puppis in near-infrared hydrogen lines. Adaptive optics imaging with VLT/NACO  

NASA Astrophysics Data System (ADS)

Context. It has been recently discovered that Cepheids harbor circumstellar envelopes (CSEs). RS Pup is the Cepheid that presents the most prominent circumstellar envelope known, the origin of which is not yet understood. Aims: Our purpose is to estimate the flux contribution of the CSE around RS Pup at the one arcsecond scale (~2000 AU) and to investigate its geometry, especially regarding asymmetries, to constrain its physical properties. Methods: We obtained near-infrared images in two narrow band filters centered on ? = 1.644 and 2.180 ?m (NB_1.64 and IB_2.18, respectively) that comprise two recombination lines of hydrogen: the 12-4 and 7-4 (Brackett ?) transitions, respectively. We used NACO's cube mode observations in order to improve the angular resolution with the shift-and-add technique, and to qualitatively study the symmetry of the spatially extended emission from the CSE with a statistical study of the speckle noise. Results: We probably detect at a 2? level an extended emission with a relative flux (compared with the star in the same filter) of 38 ± 17% in the NB_1.64 filter and 24 ± 11% in the IB_2.18 filter. This emission is centered on RS Pup and does not present any detectable asymmetry. We attribute the detected emission to the likely presence of an hydrogen envelope surrounding the star. Based on observations made with ESO telescopes at Paranal observatory under program ID 382.D-0065(A).

Gallenne, A.; Mérand, A.; Kervella, P.; Girard, J. H. V.

2011-03-01

227

Abundances of stars in lower main sequence (Mishenina+, 2008)  

NASA Astrophysics Data System (ADS)

The aim of this paper is to provide fundamental parameters and abundances with a high accuracy for a large sample of cool main sequence stars. This study is part of wider project, in which the metallicity distribution of the local thin disc is investigated from a complete sample of G and K dwarfs within 25pc. The stars were observed at high resolution and a high signal-to-noise ratio with the ELODIE echelle spectrograph. The Vsini were obtained with a calibration of the cross-correlation function. Effective temperatures were estimated by the line depth ratio method. Surface gravities (logg) were determined by two methods: parallaxes and ionization balance of iron. The Mg and Na abundances were derived using a non-LTE approximation. Abundances of other elements were obtained by measuring equivalent widths. Rotational velocities, atmospheric parameters Teff, logg, [Fe/H], Vt, and Li, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Co, Ni, and Zn abundances are provided for 131 stars. Among them, more than 30 stars are active stars with a fraction of BY Dra and RS CVn type stars for which spectral peculiarities were investigated. We find the mean abundances of the majority of elements in active and non-active stars to be similar, except for Li, and possibly for Zn and Co. The lithium is reliably detected in 54% of active stars but only in 20% of non -active stars. No correlation is found between Li abundances and rotational velocities. A possible anticorrelation of log A(Li) with the index of chromospheric activity GrandS is observed. Active and non active cool dwarfs show similar dependencies of most elemental ratios vs [Fe/H]. This allows us to use such abundance ratios to study the chemical and dynamical evolution of the Galaxy. Among active stars, no clear correlation has been found between different indicators of activity for our sample stars. (3 data files).

Mishenina, T. V.; Soubiran, C.; Bienayme, O.; Korotin, S. A.; Belik, S. I.; Usenko, I. A.; Kovtyukh, V. V.

2009-03-01

228

Lifestyles of the Stars.  

ERIC Educational Resources Information Center

Some general information on stars is provided in this National Aeronautics and Space Administration pamphlet. Topic areas briefly discussed are: (1) the birth of a star; (2) main sequence stars; (3) red giants; (4) white dwarfs; (5) neutron stars; (6) supernovae; (7) pulsars; and (8) black holes. (JN)

National Aeronautics and Space Administration, Cocoa Beach, FL. John F. Kennedy Space Center.

229

StarHeads  

NSDL National Science Digital Library

StarHeads, the last product of the Star*s Family is now available at the Centre de Donnees astronomiques de Strasbourg (CDS). StarHeads gives access to about 400 individual pages of astronomers and space scientists, and this figure is rapidly growing. Forms based browser is required.

230

X-rays and rotation among post-T Tauri G stars in Orion IC  

NASA Astrophysics Data System (ADS)

Walter and Kuhi (1981) have shown that at least 10 out of 12 T Tauri stars brighter than m(v) = 12.5 are X-ray emitters. The X-ray luminosities of these stars, L(x), are often close to the detection threshold value. One of the principal results of the present investigation is the evidence for at least a weak correlation between L(x) and V(R) sin i. If it is assumed that results obtained concerning stars in the Orion Ic Association are representative of other stellar fields, it appears that along with the RS CVn stars, pre-main-sequence G stars are among the most X-ray luminous late-type stars on the H-R diagram. A second conclusion is that the X-rays are almost certainly produced by flares and/or thin coronae close to the stellar surface.

Smith, M. A.; Pravdo, S. H.; Ku, W. H.-M.

1983-09-01

231

STAR FORMATION HISTORIES IN A CLUSTER ENVIRONMENT AT z {approx} 0.84  

SciTech Connect

We present a spectrophotometric analysis of galaxies belonging to the dynamically young, massive cluster RX J0152.7-1357 at z {approx} 0.84, aimed at understanding the effects of the cluster environment on the star formation history (SFH) of cluster galaxies and the assembly of the red sequence (RS). We use VLT/FORS spectroscopy, ACS/WFC optical, and NTT/SofI near-IR data to characterize SFHs as a function of color, luminosity, morphology, stellar mass, and local environment from a sample of 134 spectroscopic members. In order to increase the signal-to-noise ratio, individual galaxy spectra are stacked according to these properties. Moreover, the D4000, Balmer, CN3883, Fe4383, and C4668 indices are also quantified. The SFH analysis shows that galaxies in the blue faint-end of the RS have on average younger stars ({Delta}t {approx} 2 Gyr) than those in the red bright-end. We also found, for a given luminosity range, differences in age ({Delta}t {approx} 0.5-1.3 Gyr) as a function of color, indicating that the intrinsic scatter of the RS may be due to age variations. Passive galaxies in the blue faint-end of the RS are preferentially located in the low density areas of the cluster, likely being objects entering the RS from the 'blue cloud'. It is likely that the quenching of the star formation of these RS galaxies is due to interaction with the intracluster medium. Furthermore, the SFH of galaxies in the RS as a function of stellar mass reveals signatures of 'downsizing' in the overall cluster.

Demarco, R. [Department of Astronomy, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile); Gobat, R. [CEA, Laboratoire AIM, Irfu/SAp, F-91191 Gif-sur-Yvette (France); Rosati, P. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Lidman, C. [Anglo-Australian Observatory, P.O. Box 296, Epping, NSW 1710 (Australia); Rettura, A. [Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521 (United States); Nonino, M. [INAF-OAT, via G. B. Tiepolo 11, 40131 Trieste (Italy); Van der Wel, A. [Max-Planck Institute for Astronomy, Koenigstuhl 17, D-69117, Heidelberg (Germany); Jee, M. J. [Department of Physics, University of California, Davis, One Shields Avenue, Davis, CA 95616 (United States); Blakeslee, J. P. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Ford, H. C. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Postman, M., E-mail: rdemarco@astro-udec.c [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2010-12-10

232

High-Resolution N-Band Observations of the Nova RS Ophiuchi with the Keck Interferometer Nuller  

NASA Technical Reports Server (NTRS)

We report new observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nulling Instrument, approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The Keck Interferometer Nuller (KIN) operates in K-band from 8 to 12.5 pm in a nulling mode, which means that the central broad-band interference fringe is a dark fringe - with an angular width of 25 mas at mid band - rather than the bright fringe used ill a conventional optical interferometer. In this mode the stellar light itself is suppressed by the destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By subsequently shifting the neighboring bright fringe onto the center of the source brightness distribution and integrating, a second spatial regime dominated by light from the central portion of the source is almost simultaneously sampled. The nulling technique is the sparse aperture equivalent of the conventional corongraphic technique used in filled aperture telescopes. By fitting the unique KIK inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2, 4.0. or 5.4 mas for a disk profile, gaussian profile (fwhm), and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission located in the inner spatial regime relative to the outer regime. There is also evidence of a 9.7 micron silicate feature seen outside of this region. Importantly, we see spectral lines excited by the nova flash in the outer region before the blast wave reaches these regions. These lines are from neutral, weakly excited atoms which support the following interpretation. We discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earth-like planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.

Barry, R. K.; Danchi, W. C.; Sokoloski, J. L.; Koresko, C.; Wisniewski, J. P.; Serabyn, E.; Traub, W.; Kuchner, M.; Greenhouse, M. A.

2007-01-01

233

Journal editorial policies, animal welfare, and the 3Rs.  

PubMed

This study evaluates the editorial policies of a randomized sample of English language peer-reviewed journals that publish original research involving the use of animals. The aim is to identify whether journals have editorial policies relating to the use of animals in the research that they are prepared to publish and whether any policies are likely to promote animal welfare and dissemination of information on the 3Rs (reduction, refinement, replacement) within the scientific community. The results demonstrate that a significant proportion of journals publishing original research involving animals do not have any editorial policy relating to the use of animals. Of those journals that do have policies the majority simply request that the research be carried out in accordance with standard regulatory requirements. This paper aims to provide editors and publishers with the information they need to review their own editorial policies to ensure they are fulfilling their potential to promote animal welfare and dissemination of the 3Rs. PMID:20013503

Osborne, Nicola J; Payne, Daisy; Newman, Michael L

2009-12-01

234

Narcolepsy goes to school: the three Rs for school nurses.  

PubMed

The sleep disorder narcolepsy most often first appears in the teen years. It can dash the dreams of optimistic, intelligent students. It can make some students the target of nasty jokes and bullying, leaving them depressed and socially isolated. It can challenge children's self-esteem, and lowered self-esteem may last a lifetime. Typically, children with narcolepsy gain weight and have no interest in participating in anything. Many constantly feel extreme tiredness, and they may experience cataplexy. School nurses and teachers can help if they know the symptoms and practice the 3 Rs of narcolepsy: Recognize the symptoms of narcolepsy; Respect that narcolepsy is a lifelong, serious sleep disorder that needs treatment; and Refer students who exhibit symptoms to medical professionals. The 3 Rs will help students living with this lifelong disorder to get a fair shake in life's academic, social, and career arenas. PMID:24707660

Gow, Monica

2014-03-01

235

Combined XRR and RS Measurements of Nickel Silicide Films  

NASA Astrophysics Data System (ADS)

X ray reflectivity (XRR) is shown to be well suited to measure the thickness of NiSi films annealed at different temperatures. The phase transformation during the silicide reaction at different spike annealing temperatures (310°C-450°C) has been characterized by measuring the sheet resistance (Rs). Combining Rs and XRR measurements, the resistivity of the nickel silicide is deduced, showing a factor ~3 difference between the high-resistivity Ni2Si phase and the low-resistivity NiSi phase. A measured 49-point contour map shows wafer non-uniformity <1% for the resistivity of NiSi. X ray diffraction (XRD) confirmed the co-existence of both phases at the intermediate annealing temperatures.

Gonchond, J.-P.; Wyon, C.; Cacho, F.; Braeckelmann, G.; Rolland, G.; Kwakman, L. F. Tz.; Tsach, Y.; Agnihotri, D. K.; Formica, J. P.

2005-09-01

236

The BTB and CNC homology 1 (BACH1) target genes are involved in the oxidative stress response and in control of the cell cycle.  

PubMed

The regulation of gene expression in response to environmental signals and metabolic imbalances is a key step in maintaining cellular homeostasis. BTB and CNC homology 1 (BACH1) is a heme-binding transcription factor repressing the transcription from a subset of MAF recognition elements at low intracellular heme levels. Upon heme binding, BACH1 is released from the MAF recognition elements, resulting in increased expression of antioxidant response genes. To systematically address the gene regulatory networks involving BACH1, we combined chromatin immunoprecipitation sequencing analysis of BACH1 target genes in HEK 293 cells with knockdown of BACH1 using three independent types of small interfering RNAs followed by transcriptome profiling using microarrays. The 59 BACH1 target genes identified by chromatin immunoprecipitation sequencing were found highly enriched in genes showing expression changes after BACH1 knockdown, demonstrating the impact of BACH1 repression on transcription. In addition to known and new BACH1 targets involved in heme degradation (HMOX1, FTL, FTH1, ME1, and SLC48A1) and redox regulation (GCLC, GCLM, and SLC7A11), we also discovered BACH1 target genes affecting cell cycle and apoptosis pathways (ITPR2, CALM1, SQSTM1, TFE3, EWSR1, CDK6, BCL2L11, and MAFG) as well as subcellular transport processes (CLSTN1, PSAP, MAPT, and vault RNA). The newly identified impact of BACH1 on genes involved in neurodegenerative processes and proliferation provides an interesting basis for future dissection of BACH1-mediated gene repression in neurodegeneration and virus-induced cancerogenesis. PMID:21555518

Warnatz, Hans-Jörg; Schmidt, Dominic; Manke, Thomas; Piccini, Ilaria; Sultan, Marc; Borodina, Tatiana; Balzereit, Daniela; Wruck, Wasco; Soldatov, Alexey; Vingron, Martin; Lehrach, Hans; Yaspo, Marie-Laure

2011-07-01

237

Swift X-ray and ultraviolet observations of the shortest orbital period double-degenerate system RX J0806.3+1527 (HM Cnc)  

NASA Astrophysics Data System (ADS)

The system RX J0806.3+1527 (HM Cnc) is a pulsating X-ray source with 100 per cent modulation on a period of 321.5 s (5.4 min). This period reflects the orbital motion of a close binary consisting of two interacting white dwarfs. Here we present a series of simultaneous X-ray (0.2-10 keV) and near-ultraviolet (2600 Å and 1928 Å) observations that were carried out with the Swift satellite. In the near-ultraviolet, the counterpart of RX J0806.3+1527 was detected at flux densities consistent with a blackbody with a temperature of (27 ± 8) × 103 K. We found that the emission at 2600 Å is modulated at the 321.5-s period with the peak ahead of the X-ray one by 0.28 ± 0.02 cycles and is coincident within ± 0.05 cycles with the optical. This phase-shift measurement confirms that the X-ray hot spot (located on the primary white dwarf) is at about 80°-100° from the direction that connects the two white dwarfs. Albeit at lower significance, the 321.5-s signature is also present in the 1928-Å data; at this wavelength, however, the pulse peak is better aligned with that observed at X-rays. We use the constraints on the source luminosity and the geometry of the emitting regions to discuss the merits and limits of the main models for RX J0806.3+1527.

Esposito, Paolo; Israel, Gian Luca; Dall'Osso, Simone; Covino, Stefano

2014-01-01

238

The osteocalcin gene rs1800247 polymorphism in Kashubian population.  

PubMed

Osteocalcin is the most important noncollagenous protein component of the bone. Polymorphisms of osteocalcin gene were reported to be associated with bone mineral density. However, this relation was only confirmed in some populations. In this study presence of C/T polymorphism in osteocalcin gene (rs1800247) was determined in Kashubian population (northern Poland). The frequencies of variants were CC 9 %, TC 31 %, and TT 60 %, with no significant differences between genders. The genotypes were in Hardy-Weinberg equilibrium. PMID:23233116

Specjalski, Krzysztof; Porzezi?ska, Maria; Siemi?ska, Alicja; S?omi?ski, Jan M; Jassem, Ewa

2013-12-01

239

Fast H? emission line variability in RS Ophiuchi  

NASA Astrophysics Data System (ADS)

We present optical spectroscopy of the recurrent nova RS Ophiuchi with time resolutions of ˜6, ˜5 and ˜2 min. In contrast to previous high time resolution studies of the system, changes in the emission from H? are detected on time-scales as short as 2 min. Future high time resolution spectroscopy at a higher spectral resolution will be invaluable in determining the nature of the variation.

Worters, H. L.; Rushton, M. T.

2014-08-01

240

Network sensor of temperature & humidity based on RS485 interface  

Microsoft Academic Search

RS485 is an important communication protocol during CPU and external communication device, which is widely used in monitor-control system and project application. DS18B20 is used to test temperature in the sensor of temperature and humidity based on 89S52 MCU. ADC0831 is extended to convert the output signal of humidity sensor-NKHT, from which humidity value can be got. The value of

Lv Zhigang; Wang Peng

2010-01-01

241

Spectrophotometry of RS OPH during the nebular phase  

Microsoft Academic Search

Blue-wavelength spectroscopic observations of RS Oph, 201 day after the 1985 outburst are presented. An analysis of the TiO bands indicates a spectral type M4III for the secondary and a distance of 2 kpc to the system. The system of forbidden lines is excited by a shock wave, whereas Balmer emission is mainly produced by photoionization. The source of photons

J. Bohigas; J. Echevarria; F. Diego; J. A. Sarmiento

1989-01-01

242

RS3PE révélant la rechute d’un lymphome malin non hodgkinien  

Microsoft Academic Search

A patient meeting published criteria for RS3PE was found to have a synchronous recurrence of non-Hodgkin’s malignant lymphoma. Reported cases of RS3PE associated with hematological malignancies and other forms of cancer are reviewed.

Olivier Gisserot; Serge Crémades; Cécile Landais; Guénaelle Leyral; Philippe Bernard; Jean-Pierre de Jauréguiberry

2004-01-01

243

Alkaline protease from Thermoactinomyces sp. RS1 mitigates industrial pollution.  

PubMed

Proteases have found a wide application in the several industrial processes, such as laundry detergents, protein recovery or solubilization, prion degradation, meat tenderizations, and in bating of hides and skins in leather industries. But the main hurdle in industrial application of proteases is their economical production on a large scale. The present investigation aimed to exploit the locally available inexpensive agricultural and household wastes for alkaline protease production using Thermoactinomyces sp. RS1 via solid-state fermentation (SSF) technique. The alkaline enzyme is potentially useful as an additive in commercial detergents to mitigate pollution load due to extensive use of caustic soda-based detergents. Thermoactinomyces sp. RS1 showed good protease production under SSF conditions of 55 °C, pH 9, and 50 % moisture content with potato peels as solid substrate. The presented findings revealed that crude alkaline protease produced by Thermoactinomyces sp. RS1 via SSF is of potential application in silver recovery from used X-ray films. PMID:24122212

Verma, Amit; Ansari, Mohammad W; Anwar, Mohmmad S; Agrawal, Ruchi; Agrawal, Sanjeev

2014-05-01

244

Metallicity and effective temperature of the secondary of RS Ophiuchi  

NASA Astrophysics Data System (ADS)

Context: The recurrent nova RS Ophiuchi undergoes nova eruptions every ~10-20 years as a result of thermonuclear runaway on the surface of a white dwarf close to the Chandrasekhar limit. Both the progress of the eruption and its aftermath depend on the (poorly known) composition of the red giant in the RS Oph system. Aims: Our aim is to understand better the effect of the giant secondary on the recurrent nova eruption. Methods: Synthetic spectra were computed for a grid of M-giant model atmospheres having a range of effective temperatures 3200 < T_eff < 4400 K, gravities 0 < log g < 1 and abundances -4 < [Fe/H] < 0.5, and fit to infrared spectra of RS Oph as it returned to quiescence after its 2006 eruption. We have modelled the infrared spectrum in the range 1.4-2.5 ?m to determine metallicity and effective temperature of the red giant. Results: We find T_eff = 4100 ± 100 K, log g = 0.0 ± 0.5, [Fe/H] = 0.0 ± 0.5, [C/H] = -0.8 ± 0.2, [N/H] = +0.6 ± 0.3 in the atmosphere of the secondary, and demonstrate that inclusion of some dust “veiling” in the spectra cannot improve our fits.

Pavlenko, Ya. V.; Evans, A.; Kerr, T.; Yakovina, L.; Woodward, C. E.; Lynch, D.; Rudy, R.; Pearson, R. L.; Russell, R. W.

2008-07-01

245

Herschel's Star Gages  

NSDL National Science Digital Library

The EJS Herschel's Star Gages Model illustrates William Herschel's methods of "star gages" by which he attempted to map out the shape of our galaxy in 1785. Herschel's star gages (sic) relied on two important assumptions: that Herschel's telescope (his "large 20 foot" with an 18.5 inch aperture) could see to the ends of the galaxy, and that within the galactic system stars are distributed uniformly. If the first assumption holds then the stars seen in the telescope all lie within a conical region of space with the apex at the telescope and the base at the edge of the galaxy. If the second assumption holds then the number of stars seen in the telescope is proportional to the volume of this cone. Since the volume of the cone is proportional to the cube of its height, the distance to the galactic edge in any direction is proportional to the cube root of the number of stars seen in that direction. This simulation allows the user to use Herschel's method of star gages to map out the shape of an artificial "star system" for which Herschel's assumptions are valid. One window shows the view through a telescope, with a slider to change the telescopes direction (around a single fixed axis). Another window shows a 3D view of the star system, showing either all of the stars in the system or only those stars visible through the telescope. A third window shows a plot of the star gages. Plotting star gages for many different directions maps out a cross-section of the star system. An optional slider allows the user to decrease the distance to at which stars are no longer visible, and a menu allows the user to select a star system in which the stars are not distributed uniformly. These options let the user explore how violations of Herschel's two fundamental assumptions invalidate his star gage method.

Timberlake, Todd

2011-05-28

246

Damaged Mechanism Research of RS232 Interface under ElectromagneticPulse  

Microsoft Academic Search

RS232 interface executes the role of Transportation and Communication, which has became the important interface between MCU of embedded system and peripheral equipment. Because RS232 mainly work in bottom of communication protocol, so it is important to protect the infrastructure of RS232. In test, pulse double electromagnetic is pulled into RS232 data transmission lines by coupling clamp, simulated differential-mode pulse

Jing Gao; Ji-yin Sun; Yan-jie Chai; Bo Wang; Ling-jiao Tao; Fei-hu Bao

2008-01-01

247

New binary stars discovered by lunar occultations. V  

NASA Astrophysics Data System (ADS)

We present recent results from our ongoing lunar occultation program on binary stars at the TIRGO and Calar Alto observatories. Observations are presented here for a total of seventeen sources, the majority of which are resolved for the first time. These include SAO 94621, IRAS 18154-1900, SAO 98345, SAO 98363, SAO 93947, SAO 97319, SAO 97437, SAO 94986, SAO 94488, DO 11742, SAO 78027 and SAO 79799. Two speckle binaries were also observed, namely SAO 98427 and SAO 110723; this latter is discovered to be a quadruple system. SAO 77810 is found to be a new triple system. In the cases of SAO 94621 and SAO 98363, we have recorded two occultation light curves each, at different position angles: this allowed us to derive actual position angles and separations for these binary systems. We report an observation of the occultation binary SAO 94961, for which we could not detect the companion. Finally, we report also an observation of the well-studied multiple system SAO 97645 (zeta Cnc), which is discussed in detail in a separate paper. Based on observations collected at TIRGO (Gornergrat, Switzerland), and at Calar Alto (Spain). TIRGO is operated by CNR-CAISMI Arcetri, Italy. Calar Alto is operated by the German-Spanish Astronomical Center.

Richichi, A.; Ragland, S.; Calamai, G.; Richter, S.; Stecklum, B.

2000-09-01

248

Doppler images of the RS CVn binary II Pegasi during the years 1994-2002  

NASA Astrophysics Data System (ADS)

Aims: We publish 16 Doppler imaging temperature maps for the years 1994-2002 of the active RS CVn star II Peg. The six maps from 1999-2002 are based on previously unpublished observations. Through Doppler imaging we want to study the spot evolution of the star and in particular compare this with previous results showing a cyclic spot behaviour and persistent, active longitudes. Methods: The observations were collected with the SOFIN spectrograph at the Nordic Optical Telescope. The temperature maps were calculated using a Doppler imaging code based on Tikhonov regularization. Results: During 1994-2001, our results show a consistent trend in the derived longitudes of the principal and secondary temperature minima over time such that the magnetic structure appears to rotate somewhat more rapidly than the orbital period of this close binary. A sudden phase jump in the active region occurred between the observing seasons of 2001 and 2002. No clear trend over time is detected in the derived latitudes of the spots, indicating that the systematic motion could be related to the drift of the spot-generating mechanism rather than to differential rotation. The derived temperature maps are quite similar to the ones obtained earlier with different methods and the main differences occur in the spot latitudes and relative strength of the spot structures. Conclusions: We observe both longitude and latitude shifts in the spot activity of II Peg. However, our results are not consistent with the periodic behaviour presented in previous studies. Full Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/526/A44

Lindborg, M.; Korpi, M. J.; Hackman, T.; Tuominen, I.; Ilyin, I.; Piskunov, N.

2011-02-01

249

The Obesity-Associated Polymorphisms FTO rs9939609 and MC4R rs17782313 and Endometrial Cancer Risk in Non-Hispanic White Women  

PubMed Central

Overweight and obesity are strongly associated with endometrial cancer. Several independent genome-wide association studies recently identified two common polymorphisms, FTO rs9939609 and MC4R rs17782313, that are linked to increased body weight and obesity. We examined the association of FTO rs9939609 and MC4R rs17782313 with endometrial cancer risk in a pooled analysis of nine case-control studies within the Epidemiology of Endometrial Cancer Consortium (E2C2). This analysis included 3601 non-Hispanic white women with histologically-confirmed endometrial carcinoma and 5275 frequency-matched controls. Unconditional logistic regression models were used to assess the relation of FTO rs9939609 and MC4R rs17782313 genotypes to the risk of endometrial cancer. Among control women, both the FTO rs9939609 A and MC4R rs17782313 C alleles were associated with a 16% increased risk of being overweight (p?=?0.001 and p?=?0.004, respectively). In case-control analyses, carriers of the FTO rs9939609 AA genotype were at increased risk of endometrial carcinoma compared to women with the TT genotype [odds ratio (OR) ?=?1.17; 95% confidence interval (CI): 1.03–1.32, p?=?0.01]. However, this association was no longer apparent after adjusting for body mass index (BMI), suggesting mediation of the gene-disease effect through body weight. The MC4R rs17782313 polymorphism was not related to endometrial cancer risk (per allele OR?=?0.98; 95% CI: 0.91–1.06; p?=?0.68). FTO rs9939609 is a susceptibility marker for white non-Hispanic women at higher risk of endometrial cancer. Although FTO rs9939609 alone might have limited clinical or public health significance for identifying women at high risk for endometrial cancer beyond that of excess body weight, further investigation of obesity-related genetic markers might help to identify the pathways that influence endometrial carcinogenesis.

Lurie, Galina; Gaudet, Mia M.; Spurdle, Amanda B.; Carney, Michael E.; Wilkens, Lynne R.; Yang, Hannah P.; Weiss, Noel S.; Webb, Penelope M.; Thompson, Pamela J.; Terada, Keith; Setiawan, Veronica Wendy; Rebbeck, Timothy R.; Prescott, Jennifer; Orlow, Irene; O'Mara, Tracy; Olson, Sara H.; Narod, Steven A.; Matsuno, Rayna K.; Lissowska, Jolanta; Liang, Xiaolin; Levine, Douglas A.; Le Marchand, Loic; Kolonel, Laurence N.; Henderson, Brian E.; Garcia-Closas, Montserrat; Doherty, Jennifer Anne; De Vivo, Immaculata; Chen, Chu; Brinton, Louise A.; Akbari, Mohammad R.; Goodman, Marc T.

2011-01-01

250

Multiport RS232 to NTDS Multiplexor for AN/UYK-20.  

National Technical Information Service (NTIS)

A multiport RS232-NTDS Multiplexor will be discussed. This microprocessor driven hardware device has the capability of multiplexing up to 48 RS232 ports into a single parallel NTDS channel obeying intercomputer protocol. Each RS232 port has software progr...

L. E. Russo

1979-01-01

251

Association of GCKR rs780094, alone or in combination with GCK rs1799884, with type 2 diabetes and related traits in a Han Chinese population  

Microsoft Academic Search

Aims\\/hypothesis  The GCKR rs780094 and GCK rs1799884 polymorphisms have been reported to be associated with dyslipidaemia and type 2 diabetes in white Europeans. The\\u000a aim of this study was to replicate these associations in Han Chinese individuals and to identify the potential mechanisms\\u000a underlying these associations.\\u000a \\u000a \\u000a \\u000a Methods  The single nucleotide polymorphisms rs780094 and rs1799884 were genotyped in a population-based sample of Han

Q. Qi; Y. Wu; H. Li; R. J. F. Loos; F. B. Hu; L. Sun; L. Lu; A. Pan; C. Liu; H. Wu; L. Chen; Z. Yu; X. Lin

2009-01-01

252

Wolf-Rayet stars  

NASA Technical Reports Server (NTRS)

The properties and evolutionary status of WR stars are examined, reviewing the results of recent observational and theoretical investigations. Topics discussed include spectral types and line strengths, magnitudes and colors, intrinsic variability, IR and radio observations, X-ray observations, the Galactic distribution of WR stars, WR stars in other galaxies, and WR binaries. Consideration is given to the inferred masses, composition, and stellar winds of WR stars; model atmospheres; WR stars and the Galactic environment; and WR stars as a phase of stellar evolution. Diagrams, graphs, and tables of numerical data are provided.

Abbott, David C.; Conti, Peter S.

1987-01-01

253

Magnetization and NMR in pure and mixed crystal Fe[S2CN(C2H5)2] 2ClxBr1?x: 3D-Ising ferromagnetism and evidence for a strain induced ground state  

Microsoft Academic Search

The magnetization along easy and hard magnetic axes has been measured in three single crystal samples of Fe[S2CN(C2H5)2]2Clx Br1?x (x=1.000, 0.712, and 0.204), between 1.2 and 4.2 K and in applied fields up to 13 000 Oe. In the pure chloride an effective saturation moment of 3.28±0.16 ?B per iron ion is observed along the [101] easy axis. The effective

Gary C. DeFotis; J. A. Cowen

1980-01-01

254

Magnetization and NMR in pure and mixed crystal Fe[S2CN(C2H5)2] 2ClxBr1-x: 3D-Ising ferromagnetism and evidence for a strain induced ground state  

Microsoft Academic Search

The magnetization along easy and hard magnetic axes has been measured in three single crystal samples of Fe[S2CN(C2H5)2]2Clx Br1-x (x=1.000, 0.712, and 0.204), between 1.2 and 4.2 K and in applied fields up to 13 000 Oe. In the pure chloride an effective saturation moment of 3.28+\\/-0.16 muB per iron ion is observed along the [101] easy axis. The effective

Gary C. Defotis; J. A. Cowen

1980-01-01

255

RS Ophiuchi in Quiescence: Why Is It X-ray Faint?  

NASA Technical Reports Server (NTRS)

The short interval between successive outbursts of RS Oph strongly suggests that it has a high mass white dwarf accreting at a high rate. This, in turn, suggests the possibility of prominent X-ray emission from RS Oph in quiescence. However, archival quiescent X-ray observations of RS Oph show it to be a modest soft X-ray source but not a strong 2-10 keV X-ray source. In this aspect, RS Oph differs markedly from T CrB. We speculate on the possible mechanisms that could significantly suppress the 2-10 keV X-ray emission in RS Oph.

Mukai, Koji

2007-01-01

256

Symbiotic stars and other H? emission-line stars towards the Galactic bulge  

NASA Astrophysics Data System (ADS)

Symbiotic stars are interacting binaries with the longest orbital periods, and their multicomponent structure makes them rich astrophysical laboratories. The accretion of a high-mass-loss-rate red giant wind on to a white dwarf (WD) makes them promising Type Ia supernova (SN Ia) progenitors. Systematic surveys for new Galactic symbiotic stars are critical to identify new promising SN Ia progenitors (e.g. RS Oph) and to better estimate the total population size to compare against SN Ia rates. Central to the latter objective is building a complete census of symbiotic stars towards the Galactic bulge. Here we report on the results of a systematic survey of H? emission-line stars covering 35 deg2. It is distinguished by the combination of deep optical spectroscopy and long-term light curves that improve the certainty of our classifications. A total of 20 bona fide symbiotic stars are found (13 S-types, 6 D-types and 1 D'-type), 35 per cent of which show the symbiotic specific Raman-scattered O VI emission bands, as well as 15 possible symbiotic stars that require further study (six S-types and nine D-types). Light curves show a diverse range of variability including stellar pulsations (semi-regular and Mira), orbital variations and slow changes due to dust. Orbital periods are determined for five S-types and Mira pulsation periods for three D-types. The most significant D-type found is H1-45 and its carbon Mira with a pulsation period of 408.6 d, corresponding to an estimated period-luminosity relation distance of ˜6.2 ± 1.4 kpc and MK = -8.06 ± 0.12 mag. If H1-45 belongs to the Galactic bulge, then it would be the first bona fide luminous carbon star to be identified in the Galactic bulge population. The lack of luminous carbon stars in the bulge is a longstanding unsolved problem. A possible explanation for H1-45 may be that the carbon enhancement was accreted from the progenitor of the WD companion. A wide variety of unusual emission-line stars were also identified. These include central stars of planetary nebulae (PNe) [one (WC10-11) Wolf-Rayet and five with high-density cores], two novae, two WN6 Wolf-Rayet stars, two possible Be stars, a B[e] star with a bipolar outflow, an ultracompact H II region and a dMe flare star. Dust obscuration events were found in two central stars of PNe, increasing the known cases to five, as well as one WN6 star. There is considerable scope to uncover several more symbiotic stars towards the bulge, many of which are currently misclassified as PNe, provided that deep spectroscopy is combined with optical and near-infrared light curves.

Miszalski, Brent; Miko?ajewska, Joanna; Udalski, Andrzej

2013-07-01

257

VEGF, not VEGFR2, is associated with the angiogenesis effect of mini-TyrRS/mini-TrpRS in human umbilical vein endothelial cells in hypoxia.  

PubMed

The purpose of this study was to determine the relationship between VEGF and mini-TyrRS/mini-TrpRS in angiogenesis in hypoxic culture and to begin to comprehend their mechanism in angiogenesis. We designed a VEGF gene silencing assay by using lentivirus vectors, and then western blotting was used to determine the protein expression of VEGF, VEGFR2 and pVEGFR2 in three groups in hypoxic culture at 3, 6, 12, or 24 h: (1) untransfected human umbilical vein endothelial cells (HUVECs) (Control); (2) pGCSIL-GFP lentivirus vector-transduced HUVECs (Mock); and (3) pGCSIL-shVEGF lentivirus vector-transduced HUVECs (Experimental). We also detected the effects of mini-TyrRS/mini-TrpRS peptides on HUVEC proliferation, migration and tube formation after lentivirus vector transfection and VEGFR2 antibody injection. The results indicated that expression of the mini-TyrRS protein was increased, whereas that of mini-TrpRS was specifically decreased in hypoxic culture both in control and mock groups. However, this trend in protein levels of mini-TyrRS and mini-TrpRS was lost in the experimental group after transduction with the pGCSIL-shVEGF lentivirus vector. The protein expression of VEGF was increased in hypoxic culture both in control and mock groups. After transduction with the pGCSIL-shVEGF lentivirus vector, the protein level of VEGF was noticeably decreased in the experimental group; however, for VEGFR2, the results showed no significant difference in VEGFR2 protein expression in any of the groups. For pVEGFR2, we found a distinct trend from that seen with VEGF. The protein expression of pVEGFR2 was sharply increased in hypoxic culture in the three groups. The addition of mini-TyrRS significantly promoted proliferation, migration and tube formation of HUVECs, while mini-TrpRS inhibited these processes in both control and mock groups in hypoxic culture. However, these effects disappeared after transduction with the pGCSIL-shVEGF lentivirus vector in the experimental group, but no significant difference was observed after VEGFR2 antibody injection. The protein expression of VEGF is similar to that of mini-TyrRS in hypoxic culture and plays an important role in the mini-TyrRS/mini-TrpRS-stimulated proliferation, migration and tube formation of HUVECs in hypoxia. These results also suggest that the change in mini-TyrRS and mini-TrpRS expression in hypoxic culture is not related to VEGFR2 and that some other possible mechanisms, are involved in the phosphorylation of VEGFR2. PMID:23896703

Zeng, Rui; Jiang, Xiao-Fei; Chen, Yu-Cheng; Xu, Yuan-Ning; Ma, Song-Hong; Zeng, Zhi; Liu, Rui; Qiang, Ou; Li, Xian

2014-08-01

258

Association of SNP rs17465637 on chromosome 1q41 and rs599839 on 1p13.3 with Myocardial Infarction in an American Caucasian Population  

PubMed Central

Summary Recent genome-wide single nucleotide polymorphism (SNP) association studies (GWAS) have identified a number of SNPs that were significantly associated with coronary artery disease (CAD) and myocardial infarction (MI). However, many independent replication studies in other populations are needed to unequivocally confirm the GWAS association. To assess GWAS association, we have established a case-control cohort consisting of 1,231 well-characterized MI patients and 560 controls without detectable coronary stenosis, all selected from the Cleveland Genebank population. The Genebank cohort has a sufficient power to detect the association between MI and four GWAS SNPs, including rs17465637 within the MIA3 gene, rs2943634 (intergenic), rs6922269 in MTHFD1L, and rs599839 near SORT1. SNPs were genotyped by TaqMan assays and follow-up multivariate logistic regression analysis with incorporation of significant covariates showed significant association with MI for MIA3 SNP rs17465637 (P-adj=0.0034) and SORT1 SNP rs599839 (P-adj=0.009). The minor allele G of rs599839 was also associated with a decreased LDL-C level of 5–9 mg/dL per allele, but not with HDL-C or triglyceride levels. No association for MI or lipid levels was found for SNPs rs2943634 and rs6922269 (P-adj>0.05). Our results establish two SNPs, rs17465637 in MIA3 and rs599839 near SORT1 as significant risk factors for MI in the American Genebank Caucasian population.

Wang, Annabel Z.; Li, Lin; Zhang, Bin; Shen, Gong-Qing; Wang, Qing Kenneth

2011-01-01

259

Star Formation in Galaxies  

NASA Technical Reports Server (NTRS)

Topics addressed include: star formation; galactic infrared emission; molecular clouds; OB star luminosity; dust grains; IRAS observations; galactic disks; stellar formation in Magellanic clouds; irregular galaxies; spiral galaxies; starbursts; morphology of galactic centers; and far-infrared observations.

1987-01-01

260

Open Star Clusters  

NSDL National Science Digital Library

This site offers information about the formation of star clusters, the pleiades, how to calculate star cluster distances, and much more. There are also some great images that techers can use on this website.

2005-02-11

261

SMAD7 Variant rs4939827 Is Associated with Colorectal Cancer Risk in Croatian Population  

PubMed Central

Background Twenty common genetic variants have been associated with risk of developing colorectal cancer (CRC) in genome wide association studies to date. Since large differences between populations exist, generalisability of findings to any specific population needs to be confirmed. Aim The aim of this study was to perform an association study between risk variants: rs10795668, rs16892766, rs3802842 and rs4939827 and CRC risk in Croatian population. Methods An association study was performed on 320 colorectal cancer cases and 594 controls recruited in Croatia. We genotyped four variants previously associated with CRC: rs10795668, rs16892766, rs3802842 and rs4939827. Results SMAD7 variant rs4939827 (18q21.1) was significantly associated with CRC risk in Croatian population. C allele was associated with a decreased risk, odds ratio (OR): 0.70 (95% CI: 0.57-0.85, P=3.5E-04). Compared to TT homozygotes, risk was reduced by 34% in heterozygotes (OR=0.66, 95% CI: 0.47-0.92) and by 52% in CC homozygotes (OR=0.48, 95% CI: 0.33-0.72). Conclusion Our results show association of rs4939827 with colorectal cancer risk in Croatian population. The higher strength of the association in comparison to other studies suggests population-specific environmental or genetic factors may be modifying the association. More studies are needed to further describe role of rs4939827 in CRC. Likely reason for failure of replication for other 3 loci is inadequate study power.

Kirac, Iva; Matosevic, Petar; Augustin, Goran; Simunovic, Iva; Hostic, Vedran; Zupancic, Sven; Hayward, Caroline; Antoljak, Natasa; Rudan, Igor; Campbell, Harry; Dunlop, Malcolm G.; Velimir Vrdoljak, Danko; Kovacevic, Dujo; Zgaga, Lina

2013-01-01

262

Synthesis and identification of the monocation Tc(CPI) sub 6 sup + in Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and its hydrolysis products. [Tc(CNC(CH sub 3 ) sub 2 COOCH sub 3 ) sub 6 Cl and monocation Tc(CPI) sub 6 sup +  

SciTech Connect

The complex Tc(CNC(CH{sub 3}){sub 2}COOCH{sub 3}){sub 6}Cl (cation designated as Tc(CPI){sub 6}{sup +}) is one of a series of isonitrile-coordinated technetium complexes being investigated as a prototype radiopharmaceutical to evaluate myocardial perfusion. It has been prepared from the pertechnetate ion by aqueous Na{sub 2}S{sub 2}O{sub 4} reduction in the presence of the functionalized isocyanide ligand. The octahedral compound with its relatively reactive ester substituents is stable under aqueous aerobic conditions within the pH range 5-7. At high pH, however, the ester moieties undergo random, base-catalyzed hydrolysis while the six ligands remain coordinated in a fixed geometry to the central metal. The nine predicted carboxylic acid containing species were separated and identified by RP-HPLC, FAB-MS, IR, and {sup 99}Tc NMR methods. Specific k' values obtained from the RP-HPLC of these characterized compounds were used to identify technetium containing metabolites of the radiopharmaceutical. Varying rates of in vitro enzymatic hydrolysis at the terminal ester moieties of the coordinated ligands were shown to occur when this compound was incubated with blood serum from different animal species.

Kronauge, J.F.; Davison, A.; Roseberry, A.M.; Costello, C.E.; Maleknia, S. (Massachusetts Inst. of Tech., Cambridge (United States)); Jones, A.G. (Harvard Medical School and Brigham and Women's Hospital, Boston, MA (United States))

1991-10-30

263

'Polaris, Mark Kummerfeldt's Star, and My Star.'  

ERIC Educational Resources Information Center

In most astronomy courses, descriptions of stars and constellations reveal the western European origins of the astronomers who named them. However, it is suggested that a study of non-western views be incorporated into astronomy curricula. Descriptions of various stars and constellations from different cultures and instructional strategies are…

McLure, John W.

1984-01-01

264

Southern Cool Stars Misclassified as Carbon Stars  

NASA Astrophysics Data System (ADS)

We report a list of 24 red stars classified as carbon stars by one author. Close examination of them on near-IR objective-prism plates reveals that they are of M type or earlier. Three are variable in the ASAS-3 Catalog.

MacConnell, D. J.

2006-01-01

265

New Hydrodynamic Studies of the Explosion of RS Oph  

NASA Astrophysics Data System (ADS)

We have continued our studies of the evolution of Thermonuclear Runaways (TNR) in the accreted envelopes of massive white dwarfs (WD) and here we focus on the 2006 outburst of the Recurrent Symbiotic Nova (RN) RS Oph. RS Oph is a member of a small class of close binary systems in which the orbital period is long ( 460 d), the secondary is an M giant, and the WD is thought to be close in mass to the Chandrasekhar Limit. RS Oph explodes about every 20 years and the ejected material from the WD runs into the expanding outer layers of the M giant causing a wonderful display of "fireworks” that emit from gamma-rays to the radio. One important question is the secular evolution of the WD. Do the repeated outbursts cause the WD to gain or lose mass? If it is gaining mass, it could eventually reach the Chandrasekhar Limit and become a supernova or even a SN Ia if it can hide the hydrogen and helium in the system. We will report on our latest studies of TNRs using a variety of initial WD luminosities and mass accretion rates onto the WD (1.35 and 1.38 solar masses). We use our 1-D hydro code, NOVA, that now includes the Hix and Thielemann nuclear reaction network, the latest Iliadis reaction rate library, the Timmes equation of state, and OPAL opacities. We will report on the amount of ejected mass, ejection velocities, evolution time to explode, and the chemical composition of the ejecta. We gratefully acknowledge partial support from the DOE, NASA, and NSF for these studies.

Starrfield, Sumner; Sunayama, T.; Smith, M.; Iliadis, C.; Hix, W. R.; Timmes, F. X.; Sparks, W. M.

2009-05-01

266

A star tracking algorithm suitable for star sensor  

NASA Astrophysics Data System (ADS)

The sufficient attitude knowledge including location of recognized stars in star image can be obtained with Lost-in-Space case. In order to make use of the sufficient attitude knowledge, the star sensor may work in star tracking case. To achieve this, a star tracking algorithm is proposed in this paper. The previous location of recognized stars in star image may be used to obtain location of observed star in proper region of current star image with the star tracking algorithm. The simulations and real sky experiment results show that the star tracking algorithm proposed in this paper not only improves update rate of star sensor, but also avoids fault star pattern recognition. Finally, a star sensor featuring star tracking algorithm proposed in this paper was for on-orbit demonstration.

Li, Baohua; Zhang, Yingchun; Li, Huayi; Wang, Changhong

2007-03-01

267

Spectroscopy of be stars  

NASA Astrophysics Data System (ADS)

This chapter describes non supergiant B-type stars that show emission lines, called Be stars. The emission is caused by the presence of a circumstellar decretion disk. Many physical phenomena are thought to be involved in these stars, such as rapid rotation, pulsations and magnetic fields, and give rise to variations. Spectroscopy is used as a diagnostic tool to study Be stars, by professional astronomers as well as by amateurs.

Neiner, C.

2011-04-01

268

Chromospheres of Coronal Stars  

NASA Technical Reports Server (NTRS)

We summarize the main results obtained from the analysis of ultraviolet emission line profiles of coronal late-type stars observed with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. The excellent GHRS spectra provide new information on magnetohydrodynamic phenomena in the chromospheres and transition regions of these stars. One exciting new result is the discovery of broad components in the transition region lines of active stars that we believe provide evidence for microflare heating in these stars.

Linsky, Jeffrey L.; Wood, Brian E.

1996-01-01

269

[RS3PE syndrome: report of 11 cases].  

PubMed

The RS3P syndrome or remitting seronegative symmetrical synovitis with pitting oedema, was described in 1985 by McCarty. The description refers to a rheumatologic set of symptoms with an acute commence, with no erosive lesions, with seronegativity, affecting more frequently to elderly males and showing an excellent prognosis. These characteristics make it possible to difference from the rheumatoid arthritis and from the rheumatic polymyalgia. We present eleven cases which confirm the good prognosis already described, but we suggest the possibility of this syndrome could be a manifestation or the beginning of other possible diseases. PMID:11100535

Bruscas Izu, C; Medrano San Ildefonso, M; Simon, L

2000-09-01

270

RS CVn binaries: Testing the solar-stellar dynamo connection  

NASA Technical Reports Server (NTRS)

We have used the Extreme Ultraviolet Explorer satellite to study the coronal emission from the EUV-bright RS CVn binaries Sigma2 CrB, observed February 10-21, 1994, and II Peg, observed October 1-5, 1993. We present time-resolved and integrated EUV short-, medium-, and long-wavelength spectra for these binaries. Sigma2 CrB shows significant first-order emission features in the long-wavelength region. The coronal emission distributions and electron densities are estimated for those active coronae dominated by high temperature plasma.

Dempsey, R.

1995-01-01

271

Chromosome 9p21 rs10757278 polymorphism is associated with the risk of metabolic syndrome.  

PubMed

Metabolic syndrome (MetS) is a common multifactorial disorder that involves abdominal obesity, dyslipidemia, hypertension, and hyperglycemia. Genome-wide association studies have identified a major risk locus for coronary artery disease and myocardial infarction on chromosome 9p21. Here, we examined the frequency of single nucleotide polymorphisms (SNPs) on chromosome 9p21 in a sample of Turkish patients with MetS and further investigated the correlation between regional SNPs, haplotypes, and MetS. The real-time polymerase chain reaction (RT-PCR) was used to analyze 4 SNPs (rs10757274 A/G, rs2383207 A/G, rs10757278 A/G, rs1333049 C/G) in 291 MetS patients and 247 controls. Analysis of 4 SNPs revealed a significant difference in the genotype distribution for rs2383207, rs10757278, and rs1333049 between MetS patients and controls (p = 0.041, p = 0.005, p = 0.023, respectively) but not for rs10757274 (p = 0.211). MetS and control allelic frequencies for rs2383207, rs10757278, and rs1333049 were statistically different (p < 0.05). The rs2383207 AG variant, was identified as a MetS risk factor (p = 0.012, OR = 33.271; 95 % CI: 2.193-504.805) and the AA haplotype in block 1 and the GC, AG haplotypes in block 2 were associated with MetS (?(2) = 3.875, p = 0.049; ?(2) = 9.334, p = 0.0022; ? (2) = 9.134, p = 0.0025, respectively). In this study, we found that chromosome 9p21 SNP rs10757278 and related haplotypes correlate with MetS risk. This is the first report showing an association between a 9p21 variant and MetS and suggests that rs10757278 polymorphism may confer increased risk for disease. PMID:23535969

Bayoglu, Burcu; Cakmak, Huseyin Altug; Yuksel, Husniye; Can, Gunay; Karadag, Bilgehan; Ulutin, Turgut; Vural, Vural Ali; Cengiz, Mujgan

2013-07-01

272

Supernova Star Maps  

NSDL National Science Digital Library

This fun astronomy activity allows learners to experience finding stars in the night sky that will eventually go supernova. This activity is perfect for a star party outdoors. The PDF contains step-by-step instructions, photos, presentation tips, ready-to-print star maps, and links to background information.

Pacific, Astronomical S.

2008-01-01

273

Star Field Simulator.  

National Technical Information Service (NTIS)

A Star Field Simulator has been developed to serve as a source of radiation for the ASTRO Star Tracker. The star tracker and simulator are components of a motion compensation test facility located at Marshall Space Flight Center in Huntsville, Alabama. Pr...

1985-01-01

274

Main Sequence Stars  

NSDL National Science Digital Library

This website from the Australian Telescope Outreach and Education Group provides a thorough introduction to the life and death of stars. The website uses text, diagrams, and images to help explain how stars evolve. Highlights include a discussion of stellar fusion reactions and also a straightforward calculation of the lifetime of a star.

2007-06-12

275

Life Cycles of Stars  

NSDL National Science Digital Library

This Powerpoint presentation inroduces younger students to the life cycles of stars. Topics include stellar nurseries, types of stars, supernovae, the fates of stars of either high or low mass, and the creation of heavier elements by continued fusion of successively heavier elements.

276

America's Star Libraries  

ERIC Educational Resources Information Center

"Library Journal"'s new national rating of public libraries, the "LJ" Index of Public Library Service, identifies 256 "star" libraries. It rates 7,115 public libraries. The top libraries in each group get five, four, or three Michelin guide-like stars. All included libraries, stars or not, can use their scores to learn from their peers and improve…

Lyons, Ray; Lance, Keith Curry

2009-01-01

277

Polymorphisms of transforming growth factor beta 1 (RS#1800468 and RS#1800471) and esophageal squamous cell carcinoma among Zhuangese population, China.  

PubMed

Epidemiological evidence has shown two polymorphisms (namely RS#1800468G>A and RS#1800471G>C) of transforming growth factor-beta 1 (TGF-?1) gene may be involved in the cancer development. However, their role in the carcinogenic process of esophageal squamous cell carcinoma (ESCC) has been less well elaborated. We conducted a hospital-based case-control study including 391 ESCC cases and 508 controls without any evidence of tumors to evaluate the association between these two polymorphisms and ESCC risk and prognosis for Zhuangese population by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system (ARMS)-PCR techniques. We found that individuals with the genotypes with RS#1800471 C allele (namely RS#1800471-GC or -CC) had an increased risk of ESCC than those without above genotypes (namely RS#1800471-GG, adjusted odds ratio 3.26 and 5.65, respectively). Further stratification analysis showed that this polymorphism was correlated with tumor histological grades and TNM (tumor, node, and metastasis) stage, and modified the serum levels of TGF-?1. Additionally, RS#1800471 polymorphism affected ESCC prognosis (hazard ratio, 3.40), especially under high serum levels of TGF-?1 conditions. However, RS#1800468 polymorphism was not significantly related to ESCC risk. These findings indicated that TGF-?1 RS#1800471G>C polymorphism may be a genetic modifier for developing ESCC in Zhuangese population. PMID:23078766

Tang, Ren-Guang; Huang, Yong-Zhi; Yao, Li-Min; Xiao, Jian; Lu, Chuan; Yu, Qian

2013-01-01

278

Genome Sequencing of Ralstonia solanacearum Biovar 3, Phylotype I, Strains Rs-09-161 and Rs-10-244, Isolated from Eggplant and Chili in India  

PubMed Central

Ralstonia solanacearum Indian strains Rs-09-161 and Rs-10-244 were isolated from the coastal region of Goa and from the Andaman Islands. We report the draft genome sequences of these representative isolates infecting solanaceous vegetables in India.

Gaitonde, Sapna; Achari, Gauri; Asolkar, Trupti; Singh, Narendra Pratap; Carrere, Sebastien; Genin, Stephane; Peeters, Nemo

2014-01-01

279

RS3PE syndrome: a clinical and immunogenetical study.  

PubMed

This study analyses the clinical, radiological, evolutive, and immunogenetical characteristics of a series of patients diagnosed with remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome. Reviewed were the clinical charts and human leukocyte antigen (HLA) profiles of all patients treated at a single teaching hospital fulfilling the features of this syndrome according to the definition of McCarty. Twelve cases were detected in ten men and two women aged from 62 to 85 years. Rheumatoid factor was negative in all cases, and antinuclear antibodies (ANA) were positive in two. All patients achieved complete resolution of their condition within 1 year with glucocorticoid (GC) use. Two relapsed after remission but responded again to low doses of GC. Four patients showed clinical and electrodiagnostic studies consistent with carpal tunnel syndrome. No specific HLA association could be found in this report. To date, none of these patients has developed definite rheumatic diseases, infections, or malignant diseases. Although the real nature of the syndrome is still a matter of debate, at least in our context, RS3PE remains a definite condition with an excellent prognosis. PMID:12750942

Queiro, Rubén

2004-03-01

280

Information extraction of typical karst landform based on RS  

NASA Astrophysics Data System (ADS)

Guizhou Province is the most typical karst landform area of Southwest China Karst, and how to exactly extract the typical karst landform information is important to the economic development of Guizhou. Not any method based on Remote Sensing (Hereinafter referred to as RS) to extract the karst landform were reported or published. For obtaining the accuracy information of karst landform, 10 meters resolution ALOS image is used to extract the karst landform information in Guanling County of Guizhou Province in this paper. The multiscale segmentations of RS images were finished and typical of karst landform in case study area were classified with the different segmentation rules created on the eCognition Developer platform. For mostly improving the accuracy of extraction information, the experiment areas are focused on the fengcong depressions, fengcong valleys, and fenglin basins. The results show that the fengcong depressions, fengcong valleys, and fenglin basins can be respectively well extracted from the images when the segmentation scale are respectively 280, 480 and 200, shape parameter is 0.8, and tightness parameter is 0.5. We believed the research would provide an important reference to extract the karst landform information in whole Guizhou, China or global level.

Huang, Shufen; Lan, Anjun; Ma, Jiaqiong; Guo, Haixiang

2014-05-01

281

Observational constraints of modified Chaplygin gas in RS II brane  

NASA Astrophysics Data System (ADS)

FRW universe in RS II braneworld model filled with a combination of dark matter and dark energy in the form of modified Chaplygin gas (MCG) is considered. It is known that the equation of state (EoS) for MCG is a three-variable equation determined by A, ? and B. The permitted values of these parameters are determined by the recent astrophysical and cosmological observational data. Here we present the Hubble parameter in terms of the observable parameters ? m0, ? x0, H 0, redshift z and other parameters like A, B, C and ?. From Stern data set (12 points), we have obtained the bounds of the arbitrary parameters by minimizing the ? 2 test. The best-fit values of the parameters are obtained by 66 %, 90 % and 99 % confidence levels. Next due to joint analysis with BAO and CMB observations, we have also obtained the bounds of the parameters ( B, C) by fixing some other parameters ? and A. The best fit value of distance modulus ?( z) is obtained for the MCG model in RS II brane, and it is concluded that our model is perfectly consistent with the union2 sample data.

Ranjit, Chayan; Rudra, Prabir; Kundu, Sujata

2013-10-01

282

OxyR and SoxRS Regulation of fur  

PubMed Central

The cytotoxic effects of reactive oxygen species are largely mediated by iron. Hydrogen peroxide reacts with iron to form the extremely reactive and damaging hydroxyl radical via the Fenton reaction. Superoxide anion accelerates this reaction because the dismutation of superoxide leads to increased levels of hydrogen peroxide and because superoxide elevates the intracellular concentration of iron by attacking iron-sulfur proteins. We found that regulators of the Escherichia coli responses to oxidative stress, OxyR and SoxRS, activate the expression of Fur, the global repressor of ferric ion uptake. A transcript encoding Fur was induced by hydrogen peroxide in a wild-type strain but not in a ?oxyR strain, and DNase I footprinting assays showed that OxyR binds to the fur promoter. In cells treated with the superoxide-generating compound paraquat, we observed the induction of a longer transcript encompassing both fur and its immediate upstream gene fldA, which encodes a flavodoxin. This polycistronic mRNA is induced by paraquat in a wild-type strain but not in a ?soxRS strain, and SoxS was shown to bind to the fldA promoter. These results demonstrate that iron metabolism is coordinately regulated with the oxidative stress defenses.

Zheng, Ming; Doan, Bernard; Schneider, Thomas D.; Storz, Gisela

1999-01-01

283

Impact of Host IL28B rs12979860, rs8099917 in Interferon Responsiveness and Advanced Liver Disease in Chronic Genotype 3 Hepatitis C Patients  

PubMed Central

Background and Aims Genetic polymorphisms near interleukin 28B gene are associated with spontaneous and treatment induced clearance of hepatitis C virus (HCV). Our objective was to evaluate the impact of interleukin 28B single nucleotide polymorphism (rs12979860, rs8099917) variability in HCV genotype 3 infected populations. Methods 400 hepatitis C seroreactive patients from different population groups in Eastern and North Eastern part of India were assessed for host and viral genotypic analysis. 83 HCV genotype 3 infected patients were administered pegylated interferon- ribavirin therapy. Viral genotyping was performed using nested reverse transcriptase-PCR followed by direct sequencing methods. Host interleukin 28B genotyping was performed using real-time PCR based single nucleotide polymorphism analysis. Results Out of 400 hepatitis C seroreactive individuals, 73.25% were found to be RNA positive. HCV genotype 3 (65.87%) was found to be the major circulating strain in this region followed by genotype 1 (32.08%). rs12979860 CC genotype was significantly associated with sustained virological response in HCV genotype 3 infected population. In patients achieving rapid virological response, favourable CC/TT allele at rs12979860, rs8099917 was found to be predominant at both the alleles at 77%, 73.2% respectively; whereas in case of patients with relapsed HCV infection CT, TG alleles were found to be predominant. Additionally, CC genotypes at rs12979860 were found to be associated with sustained virological response in patients with high viral load (OR?=?6.75, 0.05rs12979860 TT, rs8099917 GG alleles were present in 34%, 27.6% patients with relapsed HCV infection respectively. Also unfavourable CT, TG genotypes were found to be predominant in patients with advanced stages of liver disease. Conclusion CC, TT the two favourable markers at SNPs rs12979860 and rs8099917 are strongly associated with sustained virological response in genotype 3 infected populations. This information will aid clinicians to effectively design response based treatment regimen.

Mukherjee, Anirban; Chaudhuri, Sujit; Chandra, Alok; Konar, Asokananda; Sadhukhan, Provash Chandra

2014-01-01

284

Quantitative assessment of the influence of common variations (rs8034191 and rs1051730) at 15q25 and lung cancer risk.  

PubMed

Several genome-wide association studies on lung cancer (LC) have reported similar findings of a new susceptibility locus, 15q25. After that, a number of studies reported that rs8034191 and rs1051730 polymorphisms at chromosome 15q25 have been implicated in LC risk. However, studies have yielded contradictory results. To derive a more precise estimation of the relationship, a meta-analysis of 43,742 LC cases and 58,967 controls from 17 published case-control studies was performed. Overall, significantly elevated LC risk was associated with rs8034191-C (OR?=?1.26, 95% CI 1.22-1.31, P?rs105173-A variant (OR?=?1.28, 95% CI 1.20-1.36, P?rs8034191 and rs105173 polymorphisms among Caucasians and African American, while no significant associations were observed for the two polymorphisms in East Asians. In addition, we found that rs8034191 and rs105173 confer risk, for both adenocarcinoma and squamous cell carcinoma when stratified by histological types of LC. Furthermore, our results on stratified analysis according to smoking status showed an increased LC risk in ever-smokers, while no associations were detected among never-smokers for the two polymorphisms. In conclusion, this meta-analysis demonstrated that the two common variations (rs8034191 and rs1051730) at 15q25 are a risk factor associated with increased LC susceptibility, but these associations vary in different ethnic populations. PMID:24254305

Hu, Bin; Huang, Ying; Yu, Rong-huan; Mao, Hong-ju; Guan, Chao; Zhao, Jing

2014-03-01

285

Strange Quark Star Crusts  

SciTech Connect

If strange quark matter is absolutely stable, some neutron stars may be strange quark stars. Strange quark stars are usually assumed to have a simple liquid surface. We show that if the surface tension of droplets of quark matter in the vacuum is sufficiently small, droplets of quark matter on the surface of a strange quark star may form a solid crust on top of the strange quark star. This solid crust can significantly modify the predictions for the photon emission for the surface in an observable way.

Steiner, Andrew W. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)

2007-02-27

286

Neutron Star Collision  

NSDL National Science Digital Library

Systems of orbiting neutron stars are born when the cores of two old stars collapse in supernova explosions. Neutron stars have the mass of our Sun but are the size of a city, so dense that boundaries between atoms disappear. Einsteins theory of general relativity predicts that the orbit shrinks from ripples of space-time called gravitational waves. After about 1 billion simulation years, the two neutron stars closely circle each other at 60,000 revolutions per minute. The stars finally merge in a few milliseconds, sending out a burst of gravitational waves.

Bock, Dave; Shalf, John; Swesty, Doug; Calder, Alan; Wang, Ed

1999-01-21

287

LPA rs10455872 polymorphism is associated with coronary lesions in Brazilian patients submitted to coronary angiography  

PubMed Central

Background Polymorphisms in the LPA gene were associated with coronary artery disease (CAD). However, there are differences in the allelic frequencies, Lp(a) levels, and significant association with CAD according to ethnic groups. In this scenario, the main aim of this study was to assess the influence of the LPA polymorphisms on coronary lesions in Brazilian patients. Methods 1,394 consecutive patients submitted to coronary angiography to study suggestive CAD and twenty coronary segments were scored. Genotyping for the LPA rs10455872 and rs3798220 polymorphisms were performed by high resolution melting analysis. Results The frequencies of the rs10455872 G and rs3798220 C variant alleles were 6.4% and 6.2%, respectively. LPA rs10455872 G variant allele was associated with higher odds ratio of having coronary lesions in an adjusted model (OR?=?2.02, 95% CI?=?1.10-3.72, p?=?0.02). Scores of coronary lesions (extension, severity, and Gensini scores) were significantly different among rs10455872 genotype groups. Coronary lesions was not associated with LPA rs3798220 (OR?=?1.09, 95% CI?=?0.67-1.76, p?=?0.73) and scores of coronary lesions were not different among rs3798220 genotypes. Conclusions We confirmed the association of the LPA rs10455872 with CAD in a large sample of Brazilian patients. For the LPA rs3798220, our finding is consistent with studies which showed the lack of this genetic association.

2014-01-01

288

Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement.  

PubMed

The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P < or = 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement. PMID:18923555

Jetiyanon, Kanchalee; Wittaya-Areekul, Sakchai; Plianbangchang, Pinyupa

2008-10-01

289

Ponderable soliton stars  

NASA Technical Reports Server (NTRS)

The theory of Lee and Pang (1987), who obtained solutions for soliton stars composed of zero-temperature fermions and bosons, is applied here to quark soliton stars. Model soliton stars based on a simple physical model of the proton are computed, and the properties of the solitons are discussed, including the important problem of the existence of a limiting mass and thus the possible formation of black holes of primordial origin. It is shown that there is a definite mass limit for ponderable soliton stars, so that during cooling a soliton star might reach a stage beyond which no equilibrium configuration exists and the soliton star probably will collapse to become a black hole. The radiation of ponderable soliton stars may alter the short-wavelength character of the cosmic background radiation, and may be observed as highly redshifted objects at z of about 100,000.

Chiu, Hong-Yee

1990-01-01

290

Study of short-period RS Canum Venaticorum and W Ursae Majoris binary systems: The global nature of H. cap alpha  

SciTech Connect

I present the rotation versus emission characteristics of the H..cap alpha.. line for several short-period (P< or approx. =1/sup d/) RS CVn and W UMa binary systems. Estimates for the chromospheric emission arising from each component star were obtained by subtraction of '' nonactive'' model spectra constructed from comparison stars similar in spectral type to the component stars. Disentanglement of the emission contribution from each binary component was performed by fitting Gaussians to the subtracted profiles. Enhanced H..cap alpha.. emission compared to the nonactive comparison stars is seen on all components of the short-period RS CVn systems studied, while a similar enhancement is only typically seen on the primary components of the W-type W UMa systems. A possible correlation between L/sub Halpha//L/sub bol/ (values ranging from 3 to 16 x 10/sup -5/) and the Rossby number (the ratio between the rotational period and the convective time scale) is seen for those components showing emission. Such a correlation suggests that the H..cap alpha.. line is a good diagnostic for the study of the magnetic-related activity in late-type stellar systems. Plotting the L/sub Halpha//L/sub bol/ against a measure of the tidal amplitude of Scharlemann shows that the activity of the W UMa secondary components may be shut off by the tidal forces of the primaries. The shut-off appears in those components having a tidal amplitude > or approx. =0.02. It is, however, unclear whether the tidal damping of the differential rotation is the sole mechanism responsible for the shut-off of the H..cap alpha.. emission, as the activity damping may also be attributable to the contact nature of the W UMa systems.

Barden, S.C.

1985-08-01

291

X-ray survey for pre-main-sequence stars in the Taurus-Auriga and Perseus molecular cloud complexes  

SciTech Connect

Seventy-five fields from the Einstein X-Ray Observatory IPC detector between 3h and 5h right ascension and 15 deg and 35 deg declination are examined to search for X-ray-emitting low-mass pre-main-sequence (PMS) stars. Six such stars were previously found; they appear to be similar to T Tauri stars but without dense circumstellar envelopes or winds. Finding charts are presented for 59 X-ray sources that may be PMS stars. While some are likely to be spurious X-ray sources, chance coincidences with unrelated stars, or non-PMS stellar sources such as RS CVn type binaries, approximately half are probably X-ray-selected PMS stars. 46 references.

Feigelson, E.D.; Jackson, J.M.; Mathieu, R.D.; Myers, P.C.; Walter, F.M.

1987-11-01

292

A pre-outburst signal in the long-term optical light curve of the recurrent nova RS Ophiuchi  

NASA Astrophysics Data System (ADS)

Recurrent novae are binary stars in which a white dwarf accretes matter from a less evolved companion, either a red giant or a main-sequence star. They have dramatic optical brightenings of around 5-6 mag in V in less than a day, several times a century. These occur at variable and unpredictable intervals, and are followed by an optical decline over several weeks and activity from the X-ray to the radio. The unpredictability of recurrent novae and related stellar types can hamper systematic study of their outbursts. Here we analyse the long-term light curve of RS Ophiuchi, a recurrent nova with six confirmed outbursts, most recently in 2006 February. We confirm the previously suspected 1945 outburst, largely obscured in a seasonal gap. We also find a signal via wavelet analysis that can be used to predict an incipient outburst up to a few hundred days before hand. This has never before been possible. In addition, this may suggest that the preferred thermonuclear runaway mechanism for the outbursts will have to be modified, as no pre-outburst signal is anticipated in that case. If our result indeed points to gaps in our understanding of how outbursts are driven, we will need to study such objects carefully to determine if the white dwarf is growing in mass, an essential factor if these systems are to become Type Ia supernovae. Determining the likelihood of recurrent novae being an important source population will have implications for stellar and galaxy evolution.

Adamakis, S.; Eyres, S. P. S.; Sarkar, A.; Walsh, R. W.

2011-07-01

293

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome accompanied by Parkinson's disease.  

PubMed

We encountered two cases of RS3PE (remitting seronegative symmetrical synovitis with pitting edema) syndrome accompanied by Parkinson's disease (PD). Although the etiology of RS3PE syndrome is still unknown, several possible associations, such as malignancies and viral infections, have been reported; RS3PE syndrome is thought to be an autoimmune-mediated disorder. The present patients did not have any factors which are reported to be associated with RS3PE. Whether or not the complication of PD and RS3PE syndrome is incidental needs to be further examined, and we discuss here the possible cause of association between PD and RS3PE syndrome, including dopamine agonists one of the anti-PD medications. PMID:17634716

Ito, Eiichi; Okamoto, Hiroshi; Mochizuki, Atsuko; Ohara, Kuniko; Kato, Maiko; Terashima, Yutaka; Tanaka, Eiichi; Takagi, Kae; Uchiyama, Shinichiro; Iwata, Makoto

2007-01-01

294

Functional Analysis of Deep Intronic SNP rs13438494 in Intron 24 of PCLO Gene  

PubMed Central

The single nucleotide polymorphism (SNP) rs13438494 in intron 24 of PCLO was significantly associated with bipolar disorder in a meta-analysis of genome-wide association studies. In this study, we performed functional minigene analysis and bioinformatics prediction of splicing regulatory sequences to characterize the deep intronic SNP rs13438494. We constructed minigenes with A and C alleles containing exon 24, intron 24, and exon 25 of PCLO to assess the genetic effect of rs13438494 on splicing. We found that the C allele of rs13438494 reduces the splicing efficiency of the PCLO minigene. In addition, prediction analysis of enhancer/silencer motifs using the Human Splice Finder web tool indicated that rs13438494 induces the abrogation or creation of such binding sites. Our results indicate that rs13438494 alters splicing efficiency by creating or disrupting a splicing motif, which functions by binding of splicing regulatory proteins, and may ultimately result in bipolar disorder in affected people.

Seo, Seunghee; Takayama, Kanako; Uno, Kyosuke; Ohi, Kazutaka; Hashimoto, Ryota; Nishizawa, Daisuke; Ikeda, Kazutaka; Ozaki, Norio; Nabeshima, Toshitaka; Miyamoto, Yoshiaki; Nitta, Atsumi

2013-01-01

295

The two-component system CprRS senses cationic peptides and triggers adaptive resistance in Pseudomonas aeruginosa independently of ParRS.  

PubMed

Cationic antimicrobial peptides pass across the outer membrane by interacting with negatively charged lipopolysaccharide (LPS), leading to outer membrane permeabilization in a process termed self-promoted uptake. Resistance can be mediated by the addition of positively charged arabinosamine through the action of the arnBCADTEF operon. We recently described a series of two-component regulators that lead to the activation of the arn operon after recognizing environmental signals, including low-Mg(2+) (PhoPQ, PmrAB) or cationic (ParRS) peptides. However, some peptides did not activate the arn operon through ParRS. Here, we report the identification of a new two-component system, CprRS, which, upon exposure to a wide range of antimicrobial peptides, triggered the expression of the LPS modification operon. Thus, mutations in the cprRS operon blocked the induction of the arn operon in response to several antimicrobial peptides independently of ParRS but did not affect the response to low Mg(2+). Distinct patterns of arn induction were identified. Thus, the responses to polymyxins were abrogated by either parR or cprR mutations, while responses to other peptides, including indolicidin, showed differential dependency on the CprRS and ParRS systems in a concentration-dependent manner. It was further demonstrated that, following exposure to inducing antimicrobial peptides, cprRS mutants did not become adaptively resistant to polymyxins as was observed for wild-type cells. Our microarray studies demonstrated that the CprRS system controlled a quite modest regulon, indicating that it was quite specific to adaptive peptide resistance. These findings provide greater insight into the complex regulation of LPS modification in Pseudomonas aeruginosa, which involves the participation of at least 4 two-component systems. PMID:23006746

Fernández, Lucía; Jenssen, Håvard; Bains, Manjeet; Wiegand, Irith; Gooderham, W James; Hancock, Robert E W

2012-12-01

296

Observations of Magnetically Active Binary Stars using Phoenix  

NASA Astrophysics Data System (ADS)

We present observations of several magnetically-active, post-main sequence binary systems (all of the RS CVn class) obtained with the NOAO Phoenix Infrared Spectrograph. Our high-resolution spectra are centered on the 6397cm-1 (1.563? m) lines of OH. These lines are temperature-sensitive and thus are a good diagnostic of the area coverage of dark, cool starspots on the stars (O'Neal and Neff 1997). Our new observations, using Phoenix, are of higher resolution and greater signal-to-noise than those we presented previously. By modeling the active stars as the sum of an inactive comparison star (to represent the active star's photosphere)and an M star (to represent the spots), we measure starspot filling factors on II Peg, V1762 Cyg, ? Gem, and ? And. We find filling factors similar to those we previously measured for the same stars using TiO bands. We also (for the first time) fit the spectra of double-lined binary stars with this technique, enabling us to determine the level of starspot coverage on the active components. Our spectra also contain the highly Zeeman-sensitive (g=3) Fe I 6388cm-1 line; analysis of this feature enables us to measure the mean field strength and area filling factor of the magnetic regions of the active stars. In the future we will apply Doppler imaging techniques, adapted to our H-band spectra, to our observations in order to derive images of the starspot distributions. The authors were guest observers at Kitt Peak National Observatory, National Optical Astronomy Observatories.

O'Neal, D.; Mines, J. K.; Neff, J. E.; Saar, S. H.

2000-05-01

297

Recurrent Novae as a Progenitor System of Type Ia Supernovae. I. RS Ophiuchi Subclass: Systems with a Red Giant Companion  

NASA Astrophysics Data System (ADS)

Theoretical light curves of four recurrent novae in outburst are modeled to obtain various physical parameters. The four objects studied here are those with a red giant companion, i.e., T Coronae Borealis, RS Ophiuchi, V745 Scorpii, and V3890 Sagittarii. Our model consists of a very massive white dwarf (WD) with an accretion disk and a red giant companion. Light-curve calculation includes reflection effects of the companion star and the accretion disk together with a shadowing effect on the companion by the accretion disk. We also include a radiation-induced warping instability of the accretion disk to reproduce the second peak of T CrB outbursts. The early visual light curves are well reproduced by applying a thermonuclear runaway model to a very massive white dwarf close to the Chandrasekhar mass limit, i.e., MWD=1.37+/-0.01 Msolar for T CrB and 1.35+/-0.01 Msolar for RS Oph with solar metallicity (Z=0.02), but 1.377+/-0.01 Msolar for RS Oph with low metallicity (Z=0.004), 1.35+/-0.01 Msolar for V745 Sco, and 1.35+/-0.01 Msolar for V3890 Sgr. Optically thick winds, which blow from the WDs during the outbursts, play a key role in determining the nova duration and the speed of decline because the wind quickly reduces the envelope mass on the WD. The envelope mass at each optical maximum is also estimated to be ?M~3×10-6 Msolar (T CrB), 2×10-6 Msolar (RS Oph), 5×10-6 Msolar (V745 Sco), 3×10-6 Msolar (V3890 Sgr), indicating average mass accretion rates of Macc~0.4×10-7 Msolar yr-1 (80 yr; T CrB), 1.2×10-7 Msolar yr-1 (18 yr; RS Oph), 0.9×10-7 Msolar yr-1 (52 yr; V745 Sco), and 1.1×10-7 Msolar yr-1 (28 yr; V3890 Sgr) during the quiescent phase before the last outburst. Although a large part of the envelope mass is blown off in the wind, each WD retains a substantial part of the envelope mass after hydrogen burning ends. Thus, we have obtained net mass-increasing rates of the WDs as MHe~0.1×10-7 Msolar yr-1 (T CrB), 0.12×10-7 Msolar yr-1 (RS Oph), 0.05×10-7 Msolar yr-1 (V745 Sco), 0.11×10-7 Msolar yr-1 (V3890 Sgr). These results strongly indicate that the WDs in the recurrent novae have now grown to near the Chandrasekhar mass limit and will soon explode as a Type Ia supernova if the WDs consist of carbon and oxygen. We have also clarified the reason that T CrB shows a secondary maximum but the other three systems do not.

Hachisu, Izumi; Kato, Mariko

2001-09-01

298

Decoding of QOSTBC concatenates RS code using parallel interference cancellation  

NASA Astrophysics Data System (ADS)

Comparing with orthogonal space time block code (OSTBC), quasi orthogonal space time block code (QOSTBC) can achieve high transmission rate with partial diversity. In this paper, we present a QOSTBC concatenated Reed-Solomon (RS) error correction code structure. At the receiver, pairwise detection and error correction are first implemented. The decoded data are regrouped. Parallel interference cancellation (PIC) and dual orthogonal space time block code (OSTBC) maximum likelihood decoding are deployed to the regrouped data. The pure concatenated scheme is shown to have higher diversity order and have better error performance at high signal-to-noise ratio (SNR) scenario than both QOSTBC and OSTBC schemes. The PIC and dual OSTBC decoding algorithm can further obtain more than 1.3 dB gains than the pure concatenated scheme at 10-6 bit error probability.

Yan, Zhenghang; Lu, Yilong; Ma, Maode; Yang, Yuhang

2010-02-01

299

A near-infrared shock wave in the 2006 outburst of recurrent nova RS Ophiuchi  

Microsoft Academic Search

Near-infrared spectra are presented for the recent 2006 outburst of the\\u000arecurrent nova RS Ophiuchi (RS Oph).We report the rare detection of an infrared\\u000ashock wave as the nova ejecta plows into the pre-existing wind of the secondary\\u000ain the RS Oph system consisting of a white dwarf (WD) primary and a red giant\\u000asecondary. The evolution of the shock

Ramkrishna Das; Dipankar P. K. Banerjee; Nagarhalli M. Ashok

2006-01-01

300

LH*RS: A High-Availability Scalable Distributed Data Structure using Reed Solomon Codes  

Microsoft Academic Search

LH*RS is a new high-availability Scalable Distributed Data Structure (SDDS). The data storage scheme and the search performance of LH*RS are basically these of LH*. LH*RS manages in addition the parity information to tolerate the unavailability of k ? 1 server sites. The value of k scales with the file, to prevent the reliability decline. The parity calculus uses the

Witold Litwin; Thomas J. E. Schwarz

2000-01-01

301

Efficient module-based modeling for a large-scale AS\\/RS-AGV system  

Microsoft Academic Search

A method of modeling large-scale AS\\/RS-AGV systems is proposed in an attempt to describe the AS\\/RS precisely and flexibly in which a lot of items are stored and retrieved. The system considered in this study consists of the large-scale AS\\/RS with stacker cranes, the looped track AGV system, aisle conveyors connecting these two systems, and incoming and outgoing conveyors. There

Soemon Takakuwa

1996-01-01

302

Flexible modeling and analysis of large-scale AS\\/RS-AGV systems  

Microsoft Academic Search

A method of modeling large-scale AS\\/RS-AGV systems is proposed in an attempt to describe the AS\\/RS precisely and flexibly in which a lot of items are stored and retrieved. The system considered in this study consists of the large-scale AS\\/RS with stacker cranes, the looped-track AGV system, aisle conveyors connecting these two systems, and incoming and outgoing conveyors. There are

Soemon Takakuwa

1995-01-01

303

Pasting characteristics and in vitro digestibility of ?-irradiated RS 4 waxy maize starches  

Microsoft Academic Search

The effect of ?-irradiation on the physicochemical properties of cross-linked waxy maize resistant starches was examined. The cross-linked waxy maize starches contained resistant starch (RS) of 56.1 and 63.5%, respectively for 5 and 10% sodium trimetaphosphate (STMP)\\/sodium tripolyphosphate (STPP) cross-linking, and the RS contents slightly decreased as the irradiation dose increased whereas the RS content in unmodified waxy maize starch

H.-J. Chung; S.-Y. Lee; J.-H. Kim; J.-W. Lee; M.-W. Byun; S.-T. Lim

2010-01-01

304

Single nucleotide polymorphism rs6716901 in SLC25A12 gene is associated with Asperger syndrome  

PubMed Central

Background Autism Spectrum Conditions (ASC) are a group of developmental conditions which affect communication, social interactions and behaviour. Mitochondrial oxidative dysfunction has been suggested as a mechanism of autism based on the results of multiple genetic association and expression studies. SLC25A12 is a gene encoding a calcium-binding carrier protein that localizes to the mitochondria and is involved in the exchange of aspartate for glutamate in the inner membrane of the mitochondria regulating the cytosolic redox state. rs2056202 SNP in this gene has previously been associated with ASC. SNPs rs6716901 and rs3765166 analysed in this study have not been previously explored in association with AS. Methods We genotyped three SNPs (rs2056202, rs3765166, and rs6716901) in SLC25A12 in n?=?117 individuals with Asperger syndrome (AS) and n?=?426 controls, all of Caucasian ancestry. Results rs6716901 showed significant association with AS (P?=?0.008) after correcting for multiple testing. We did not replicate the previously identified association between rs2056202 and AS in our sample. Similarly, rs3765166 (P?=?0.11) showed no significant association with AS. Conclusion The present study, in combination with previous studies, provides evidence for SLC25A12 as involved in the etiology of AS. Further cellular and molecular studies are required to elucidate the role of this gene in ASC.

2014-01-01

305

Assessing the search for and implementation of the Three Rs: a survey among scientists.  

PubMed

A survey among scientists into the current practice of searching for Replacement, Reduction and Refinement (Three Rs) alternatives, highlights the gap between the statutory required need to apply the Three Rs concept whenever possible and the lack of criteria for searching for Three Rs alternatives. A questionnaire was distributed to 342 scientists (Federation of European Laboratory Animal Science Associations [FELASA] Category C and B individuals), of which 67 responded. These scientists are customers of the Central Animal Laboratory of Radboud University Nijmegen Medical Centre. The results indicate that there is room for improvement in searching effectively for the Three Rs: skills in searching biomedical databases for Three Rs alternatives are limited, knowledge of specialised Three Rs databases is very limited, and satisfaction on the availability and accessibility of Three Rs information is low. None of the respondents allocate budget for a specific Three Rs alternatives search, although 50% do spend, on average, two hours engaged in this search for each application to their animal ethics committees. The majority of the respondents expressed the wish that the search for alternatives could be easier and less time consuming, and prefer to achieve this through the service offered by specialists at the Central Animal Laboratory. On the basis of the results from the questionnaire, the 3R Research Centre was established, with the aim of providing services and support for biomedical scientists, to improve the search for, and subsequent implementation of, the Three Rs. PMID:19678731

Leenaars, Marlies; Savenije, Bart; Nagtegaal, Anne; van der Vaart, Lilian; Ritskes-Hoitinga, Merel

2009-07-01

306

The interpretation and application of the three Rs by animal ethics committee members.  

PubMed

The Three Rs form the basis of review of animal-use protocols by Animal Ethics Committees (AECs), but little research has examined how AECs actually interpret and implement the Three Rs. This topic was explored through in-depth, open-ended interviews with 28 members of AECs at four Canadian universities. In describing protocol review, AEC members rarely mentioned the Three Rs, but most reported applying some aspects of the basic concepts. Comments identified several factors that could impede full application of the Three Rs: incomplete understanding of the Three Rs (especially Refinement), trust that researchers implement Replacement and Reduction themselves, belief by some members that granting agency review covers the Three Rs, focus on sample size rather than experimental design to achieve Reduction, focus on harm caused by procedures to the exclusion of housing and husbandry, and lack of consensus on key issues, notably on the nature and moral significance of animal pain and suffering, and on whether AECs should minimise overall harm to animals. The study suggests ways to achieve more consistent application of the Three Rs, by providing AECs with up-to-date information on the Three Rs and with access to statistical expertise, by consensus-building on divisive issues, and by training on the scope and implementation of the Three Rs. PMID:16268760

Schuppli, Catherine A; Fraser, David

2005-10-01

307

ESR1 rs9340799 Is Associated with Endometriosis-Related Infertility and In Vitro Fertilization Failure  

PubMed Central

Estrogen receptor alpha has a central role in human fertility by regulating estrogen action in all human reproductive tissues. Leukemia inhibitory factor (LIF) expression, a cytokine critical for blastocyst implantation, is mediated by estrogen signaling, so we hypothesized that ESR1 gene polymorphisms might be candidate risk markers for endometriosis-related infertility and in vitro fertilization (IVF) failure. We included 98 infertile women with endometriosis, 115 infertile women with at least one IVF failure and also 134 fertile women as controls. TaqMan SNP assays were used for genotyping LIF (rs929271), MDM2 (rs2279744), MDM4 (rs1563828), USP7 (rs1529916), and ESR1 (rs9340799 and rs2234693) polymorphisms. The SNP ESR1 rs9340799 was associated with endometriosis-related infertility (P < 0.001) and also with IVF failure (P = 0.018). After controlling for age, infertile women with ESR1 rs9340799 GG genotype presented 4-fold increased risk of endometriosis (OR 4.67, 95% CI 1.84–11.83, P = 0.001) and 3-fold increased risk of IVF failure (OR 3.33, 95% CI 1.38–8.03, P = 0.007). Our results demonstrate an association between ESR1 rs9340799 polymorphism and infertile women with endometriosis and also with women who were submitted to IVF procedures and had no blastocyst implantation.

Paskulin, Diego Davila; Cunha-Filho, Joao Sabino; Paskulin, Livia Davila; Souza, Carlos Augusto Bastos; Ashton-Prolla, Patricia

2013-01-01

308

ESR1 rs9340799 is associated with endometriosis-related infertility and in vitro fertilization failure.  

PubMed

Estrogen receptor alpha has a central role in human fertility by regulating estrogen action in all human reproductive tissues. Leukemia inhibitory factor (LIF) expression, a cytokine critical for blastocyst implantation, is mediated by estrogen signaling, so we hypothesized that ESR1 gene polymorphisms might be candidate risk markers for endometriosis-related infertility and in vitro fertilization (IVF) failure. We included 98 infertile women with endometriosis, 115 infertile women with at least one IVF failure and also 134 fertile women as controls. TaqMan SNP assays were used for genotyping LIF (rs929271), MDM2 (rs2279744), MDM4 (rs1563828), USP7 (rs1529916), and ESR1 (rs9340799 and rs2234693) polymorphisms. The SNP ESR1 rs9340799 was associated with endometriosis-related infertility (P < 0.001) and also with IVF failure (P = 0.018). After controlling for age, infertile women with ESR1 rs9340799 GG genotype presented 4-fold increased risk of endometriosis (OR 4.67, 95% CI 1.84-11.83, P = 0.001) and 3-fold increased risk of IVF failure (OR 3.33, 95% CI 1.38-8.03, P = 0.007). Our results demonstrate an association between ESR1 rs9340799 polymorphism and infertile women with endometriosis and also with women who were submitted to IVF procedures and had no blastocyst implantation. PMID:24427778

Paskulin, Diego Davila; Cunha-Filho, João Sabino; Paskulin, Livia Davila; Souza, Carlos Augusto Bastos; Ashton-Prolla, Patricia

2013-01-01

309

PG 1159 Stars  

NASA Astrophysics Data System (ADS)

The PG 1159 stars form a small group of about 30 objects. They are named after the prototype PG 1159-035 (=GW Vir), which was discovered in the Palomar-Green survey. They are hot post-asymptotic giant branch (post-AGB) stars and their location in the HR diagram coincides with the hottest central stars of PLANETARY NEBULAE (CSPN) and the hottest WHITE DWARFS (WD). The most peculiar characteristic ...

Werner, K.; Murdin, P.

2000-11-01

310

Sizing up the stars  

NASA Astrophysics Data System (ADS)

For the main part of this dissertation, I have executed a survey of nearby, main sequence A, F, and G-type stars with the CHARA Array, successfully measuring the angular diameters of forty-four stars to better than 4% accuracy. The results of these observations also yield empirical determinations of stellar linear radii and effective temperatures for the stars observed. In addition, these CHARA-determined temperatures, radii, and luminosities are fit to Yonsei-Yale isochrones to constrain the masses and ages of the stars. These quantities are compared to the results found in Allende Prieto & Lambert (1999), Holmberg et al. (2007), and Takeda (2007), who indirectly determine these same properties by fitting models to observed photometry. I find that for most cases, the models underestimate the radius of the star by ~ 12%, while in turn they overestimate the effective temperature by ~ 1.5-4%, when compared to my directly measured values, with no apparent correlation to the star's metallicity or color index. These overestimated temperatures and underestimated radii in these works appear to cause an additional offset in the star's surface gravity measurements, which consequently yield higher masses and younger ages, in particular for stars with masses greater than ~ 1.3 [Special characters omitted.] . Alternatively, these quantities I measure are also compared to direct measurements from a large sample of eclipsing binary stars in Andersen (1991), and excellent agreement is seen within both data sets. Finally, a multi-parameter solution is found to fit color-temperature-metallicity values of the stars in this sample to provide a new calibration of the effective temperature scale for these types of stars. Published work in the field of stellar interferometry and optical spectroscopy of early-type stars are presented in Appendix D and E, respectively. INDEX WORDS: Interferometry, Infrared, Stellar Astronomy, Fundamental Properties, Effective Temperatures, Stellar Radii

Boyajian, Tabetha S.

311

Jars of Stars: Advanced  

NSDL National Science Digital Library

This math activity uses stars, jars, and scoops to help learners build their estimation and volume skills. As you play, estimate how many scoops of stars it will take to fill a variety of jars. Use multiplication to create a close estimate of how many stars are in each jar. The activity guide contains a material list, sample questions to ask, literary connections, extensions, and alignment to local and national standards.

Houston, Children'S M.

2004-01-01

312

Orbiting Binary Stars  

NSDL National Science Digital Library

This simulation demonstrates the path of binary stars' orbit. The user is able to set the masses, orbital separation, orbital eccentricity, the inclination angle to our line of sight, and the angle of the nodes of two orbiting stars. The observed velocities of the two stars, and the Doppler shifted spectral lines are also shown in the upper right box. The site also includes definitions of terms used, instructions on how to use the simulation and a few examples.

Kolena, John

2007-12-11

313

STAR TPC Gas System  

Microsoft Academic Search

The STAR TPC (Time Projection Chamber) Gas System supplies either of two mixtures, P10 (Ar 90% + CH4 10%) or C2H6 50% + He 50%, to the STAR TPC (STAR Project, Brookhaven, USA) at a controlled pressure. This system regulates the pressure and com- position of the gas while monitoring gas temperature, O2 and H2O. A computer data ac- quisition

L. Kotchenda; S. Kozlov; P. Kravtsov; A. Markova; M. Strikhanov; B. Stringfellow; V. Trofimova; R. Wells; H. Wiemand

2002-01-01

314

Neutron star cooling  

Microsoft Academic Search

The impact of nuclear physics theories on cooling of isolated neutron stars\\u000ais analyzed. Physical properties of neutron star matter important for cooling\\u000aare reviewed such as composition, the equation of state, superfluidity of\\u000avarious baryon species, neutrino emission mechanisms. Theoretical results are\\u000acompared with observations of thermal radiation from neutron stars. Current\\u000aconstraints on theoretical models of dense matter,

D. G. Yakovlev; O. Y. Gnedin; M. E. Gusakov; A. D. Kaminker; K. P. Levenfish; A. Y. Potekhin

2005-01-01

315

Production of multiple wheat-rye 1RS translocation stocks and genetic analysis of LMW subunits of glutenin and gliadins in wheats using these stocks  

Microsoft Academic Search

A triple (1AL.1RS\\/1BL.1RS\\/1DL.1RS) and three double (1AL.1RS\\/1BL.1RS, 1AL.1RS\\/1DL.1RS, 1BL.1RS\\/1DL.1RS) wheat-rye 1RS translocation stocks were isolated from a segregating population using the Gli-1, Tri-1 and Sec-1 seed proteins as genetic markers. These stocks carried 42 chromosomes and formed the expected multivalents (frequency of 14–25%) at metaphase 1. They gave floret fertility ranging from 40–60%. These stocks were subsequently used to determine

R. B. Gupta; K. W. Shepherd

1993-01-01

316

First Science with the Keck Interferometer Nuller High Spatial Resolution N-Band Observations of the Recurrent Nova RS Ophiuchi  

NASA Technical Reports Server (NTRS)

We report observations of the nova RS 0phiuchi using the Keck Interferometer Nuller (KIN) taken approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The KIN operates in N-band from approx. 8 to 12.5 microns in a nulling mode - the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture te1escopes. In this mode the stellar light is suppressed by a destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. In a second, constructive-fringe mode, the instrument detects primarily the light from the central, bright source. These are the outer and inner spatial regimes, resprectively. We will describe the capabilities of the KIN, including these unique modes, and outline how they were key in our discovery that dust does not appear to be created in the outburst as in previous models, but instead was created between nova events. We also show how these first results from the KIN are consistent with Spitzer data. The KIN data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf (WD) relative to the outer regime. There are also nebular emission lines and evidence of hot silicate dust in the outer spatial region, centered at approximately 17 AU from the WD, that are not found in the inner regime. The KIN and Spitzer data suggest that these emissions were excited by the nova flash in the outer spatial regime before the blast wave reached these regions. We describe the present results in terms of a new model for dust creation in recurrent novae that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earth-like planets around nearby stars for the Terrestrial Planet Finder and Darwin missions.

Barry, Richard K.; Danchi, W. C.; Traub, W.; Kuchner, M.; Wisniewski, J. P.; Akeson, R.; Colavita, M.; Greenhouse, M, A.; Koresko, C.; Serabyn, E.; Sokoloski, J. L.

2008-01-01

317

NASA's Nearby Stars Project  

NASA Astrophysics Data System (ADS)

In 1998, NASA initiated the Nearby Stars Project (NSTARS), which intends to make a vigorous reconnaissance of stars within 20 parsecs of the Sun. The NSTARS goal is to develop a comprehensive observational and theoretical understanding of the nearest stars. Information is being gathered about each star's fundamental characteristics, including: astrometry, luminosity, temperature, optical/infrared spectral energy distribution, age, activity level, metallicity, companions (both stellar and planetary), and quantification of exozodiacal dust, if any. NSTARS currently includes two primary areas of effort, Database and Research. Construction has begun on the Database, which will be web-accessible and provide important high-quality information about the nearest stars. Examples will be shown of prototype "Front" and "Back" pages included in the Database. An important difference between NSTARS and previous nearby star efforts such as the Catalog of Nearby Stars is the presence of a significant, directed, Research effort. NSTARS is supporting observing programs to discover "missing" members of the nearby star sample, and to characterize the population astrometrically, photometrically, and spectroscopically. NSTARS will also impose quality control on data already available. Given the public's clear interest in stars near to the Sun, a third area of effort, Education, is planned once the first two efforts are firmly established. Through the NSTARS Project, a high-quality resource will be available for professional astronomers worldwide, as well as any members of the public who might be interested.

Henry, T. J.; Backman, D. E.; Christensen, R.; Moller, K.; Vacin, E.; West, S.

1998-12-01

318

Star Market Scandal  

NSDL National Science Digital Library

The is one several activities in which students are required to access and analyze actual data from NASA missions, including video interviews with real NASA scientists, to solve a mystery. In this mystery, students explore stars and their properties, investigate the different characteristics of stars, and look for trends and patterns to determine what kinds of stars different companies are buying, and why. During the activity, students analyze a list of stars purchased by each company using tools showing a star's luminosity in infrared, x-ray, and visible ranges of light, and tools that plot the stars in different ways. Star Market can be used as a supplemental learning tool to support the scientific method, understanding the life cycle of stars, and learning about the different reasons scientists study stars. It is one several activities within "Space Mysteries," a series of inquiry-driven, interactive Web explorations. Each Mystery in "Space Mysteries" is designed to teach at least one physical science concept (e.g. interactions of energy and matter, structures and properties of matter, energy, motion, or forces), and is accompanied by materials to be used by classroom teachers.

319

Delta Scuti stars: Theory  

SciTech Connect

The purpose of asteroseismology is not only to derive the internal structure of individual stars from their observed oscillation frequencies, but also to test and extend one`s understanding of the physics of matter under the extremes of temperature, density, and pressure found in stellar interiors. In this review, the author hopes to point out what one can learn about the Sun by studying {delta} Scuti stars, as well as what one can learn about stars more massive or evolved than the Sun. He discusses some of the difficulties in theoretical approaches to asteroseismology for {delta} Scuti stars, using FG Vir, {delta} Scuti, and CD-24{degree} 7599 as examples.

Guzik, J.A.

1998-03-01

320

Massive soliton stars  

NASA Technical Reports Server (NTRS)

The structure of nontopological solutions of Einstein field equations as proposed by Friedberg, Lee, and Pang (1987) is examined. This analysis incorporates finite temperature effects and pair creation. Quarks are assumed to be the only species that exist in interior of soliton stars. The possibility of primordial creation of soliton stars in the incomplete decay of the degenerate vacuum in early universe is explored. Because of dominance of pair creation inside soliton stars, the luminosity of soliton stars is not determined by its radiative transfer characteristics, and the surface temperature of soliton stars can be the same as its interior temperature. It is possible that soliton stars are intense X-ray radiators at large distances. Soliton stars are nearly 100 percent efficient energy converters, converting the rest energy of baryons entering the interior into radiation. It is possible that a sizable number of baryons may also be trapped inside soliton stars during early epochs of the universe. In addition, if soliton stars exist they could assume the role played by massive black holes in galactic centers.

Chiu, Hong-Yee

1990-01-01

321

TNFSF4 gene polymorphism rs3861950 but not rs3850641 is associated with the risk of cerebral infarction in a Chinese population.  

PubMed

Tumor necrosis factor superfamily member 4 (TNFSF4) plays a key role in the process of atherosclerosis, a common risk factor for both myocardial and cerebral infarctions. Recent studies indicate that the single nucleotide polymorphism (SNP) rs3850641 in TNFSF4 is associated with higher risk of myocardial infarction, but little is known about the association between TNFSF4 variation and cerebral infarction (CI). A case-control study involving 385 CI patients and 385 age-matched, sex-matched non-CI controls was conducted in a Chinese population, only the most common subtype, atherosclerosis CI, was recruited. Two SNPs of TNFSF4, rs3850641 and rs3861950, were genotyped by the TaqMan SNP genotyping method, and verified partly by genomic DNA sequencing. The results revealed a significant allelic association between rs3861950 and CI (Odds ration = 1.733, 95 % confidence interval = 1.333-2.254, P = 0.000). Genotypic association analysis demonstrated that the CC genotype of rs3861950 confers susceptibility to CI (Odds ration = 2.896, 95 % confidence interval = 1.368-6.132), and it was associated with a significantly higher risk of ischemic stroke (Odds ration = 3.520, 95 % confidence interval = 1.546-8.015, P = 0.003) after adjusting for the other confirmed risk factors such as the history of hypertension, diabetes, CAD, smoking and alcohol drinking. While the odds ratio of the T allele to the C allele was 1.733 (95 % confidence interval: 1.333-2.254). However, there was no significant association between rs3850641 and CI (Odds ration = 1.288, 95 % confidence interval = 0.993-1.670, P = 0.056). TNFSF4 gene polymorphism rs3861950, but not rs3850641, is associated with the risk of atherosclerosis CI in a Chinese population. PMID:23184501

Feng, Jie; Liu, Yun-Hai; Yang, Qi-Dong; Zhu, Zan-Hua; Xia, Kun; Tan, Xing-Lin; Xia, Jian; Gu, Wen-Ping; Zhou, Lin; Xiao, Bo; Tang, Bei-Sha; Huang, Qing

2013-10-01

322

First 2.2 micrometer results from the iota interferometer  

NASA Technical Reports Server (NTRS)

We present the first infrared fringe visibility measurements made with the Infrared Optical Telescope Array on Mt. Hopkins. Effective temperatures are derived for RX Boo, RS Cnc, and Beta Peg. RX Boo is the coolest small-amplitude variable giant star to have an effective temperature determination. We compare the size of its photosphere at infrared wavelengths with the sizes of its SiO and H20 radio emission regions. We also discuss initial performance parameters for the interferometer.

Dyck, H. M.; Benson, J. A.; Carlton, N. P.; Coldwell, C.; Lacasse, M. G.; Nisenson, P.; Panasyuk, A.; Papaliolios, C.; Pearlman, R. D.; Reasenberg, R. D.

1995-01-01

323

Genetic and Functional Assessment of the Role of the rs13431652-A and rs573225-A Alleles in the G6PC2 Promoter That Are Strongly Associated With Elevated Fasting Glucose Levels  

PubMed Central

OBJECTIVE Genome-wide association studies have identified a single nucleotide polymorphism (SNP), rs560887, located in a G6PC2 intron that is highly correlated with variations in fasting plasma glucose (FPG). G6PC2 encodes an islet-specific glucose-6-phosphatase catalytic subunit. This study examines the contribution of two G6PC2 promoter SNPs, rs13431652 and rs573225, to the association signal. RESEARCH DESIGN AND METHODS We genotyped 9,532 normal FPG participants (FPG <6.1 mmol/l) for three G6PC2 SNPs, rs13431652 (distal promoter), rs573225 (proximal promoter), rs560887 (3rd intron). We used regression analyses adjusted for age, sex, and BMI to assess the association with FPG and haplotype analyses to assess comparative SNP contributions. Fusion gene and gel retardation analyses characterized the effect of rs13431652 and rs573225 on G6PC2 promoter activity and transcription factor binding. RESULTS Genetic analyses provide evidence for a strong contribution of the promoter SNPs to FPG variability at the G6PC2 locus (rs13431652: ? = 0.075, P = 3.6 × 10?35; rs573225 ? = 0.073 P = 3.6 × 10?34), in addition to rs560887 (? = 0.071, P = 1.2 × 10?31). The rs13431652-A and rs573225-A alleles promote increased NF-Y and Foxa2 binding, respectively. The rs13431652-A allele is associated with increased FPG and elevated promoter activity, consistent with the function of G6PC2 in pancreatic islets. In contrast, the rs573225-A allele is associated with elevated FPG but reduced promoter activity. CONCLUSIONS Genetic and in situ functional data support a potential role for rs13431652, but not rs573225, as a causative SNP linking G6PC2 to variations in FPG, though a causative role for rs573225 in vivo cannot be ruled out.

Bouatia-Naji, Nabila; Bonnefond, Amelie; Baerenwald, Devin A.; Marchand, Marion; Bugliani, Marco; Marchetti, Piero; Pattou, Francois; Printz, Richard L.; Flemming, Brian P.; Umunakwe, Obi C.; Conley, Nicholas L.; Vaxillaire, Martine; Lantieri, Olivier; Balkau, Beverley; Marre, Michel; Levy-Marchal, Claire; Elliott, Paul; Jarvelin, Marjo-Riitta; Meyre, David; Dina, Christian; Oeser, James K.; Froguel, Philippe; O'Brien, Richard M.

2010-01-01

324

Star Trek in the Schools  

ERIC Educational Resources Information Center

Describes specific educational programs for using the Star Trek TV program from kindergarten through college. For each grade level lesson plans, ideas for incorporating Star Trek into future classes, and reports of specific programs utilizing Star Trek are provided. (SL)

Journal of Aerospace Education, 1977

1977-01-01

325

Stars and Flowers, Flowers and Stars  

NASA Astrophysics Data System (ADS)

The author, a graduated from the Bucharest University (1964), actually living and working in Israel, concerns his book to variable stars and flowers, two domains of his interest. The analogies includes double stars, eclipsing double stars, eclipses, Big Bang. The book contains 34 chapters, each of which concerns various relations between astronomy and other sciences and pseudosciences such as Psychology, Religion, Geology, Computers and Astrology (to which the author is not an adherent). A special part of the book is dedicated to archeoastronomy and ethnoastronomy, as well as to history of astronomy. Between the main points of interest of these parts: ancient sanctuaries in Sarmizegetusa (Dacia), Stone Henge(UK) and other. The last chapter of the book is dedicated to flowers. The book is richly illustrated. It is designed for a wide circle of readers.

Minti, Hari

2012-12-01

326

Eclipsing Binary Stars in the OGLE-III Fields of the Small Magellanic Cloud  

NASA Astrophysics Data System (ADS)

We present a large sample of eclipsing binary stars detected in the Small Magellanic Cloud fields covering about 14 square degrees that have been monitored for eight years during the third phase of the OGLE survey. This is the largest set of such variables containing 6138 objects, of which 777 are contact and 5361 non-contact binaries. The estimated completeness of this sample is around 82%. We analyze the statistical properties of the sample and present selected interesting objects: 32 systems having eccentric orbit with visible apsidal motion, one Transient Eclipsing Binary, ten RS CVn type stars, 22 still unexplained Double-Periodic Variable stars, and 15 candidates for doubly eclipsing quadruple systems. Based on the OGLE-III proper motions, we classified 47 binaries from our sample as foreground Galactic stars. We also list candidates suitable for the SMC distance determination.

Pawlak, M.; Graczyk, D.; Soszy?ski, I.; Pietrukowicz, P.; Poleski, R.; Udalski, A.; Szyma?ski, M. K.; Kubiak, M.; Pietrzy?ski, G.; Wyrzykowski, ?.; Ulaczyk, K.; Koz?owski, S.; Skowron, J.

2013-09-01

327

Robust GRAPPA-Accelerated Diffusion-Weighted Readout-Segmented (RS)-EPI  

PubMed Central

Readout segmentation (RS-EPI) has been suggested as a promising variant to echo-planar imaging (EPI) for high-resolution imaging, particularly when combined with parallel imaging. This work details some of the technical aspects of diffusion-weighted (DW)-RS-EPI, outlining a set of reconstruction methods and imaging parameters that can both minimize the scan time and afford high-resolution diffusion imaging with reduced distortions. These methods include an efficient generalized autocalibrating partially parallel acquisition (GRAPPA) calibration for DW-RS-EPI data without scan time penalty, together with a variant for the phase correction of partial Fourier RS-EPI data. In addition, the role of pulsatile and rigid-body brain motion in DW-RS-EPI was assessed. Corrupt DW-RS-EPI data arising from pulsatile nonlinear brain motion had a prevalence of ~7% and were robustly identified via k-space entropy metrics. For DW-RS-EPI data corrupted by rigid-body motion, we showed that no blind overlap was required. The robustness of RS-EPI toward phase errors and motion, together with its minimized distortions compared with EPI, enables the acquisition of exquisite 3 T DW images with matrix sizes close to 5122.

Holdsworth, Samantha J.; Skare, Stefan; Newbould, Rexford D.; Bammer, Roland

2010-01-01

328

A Near-Infrared Shock Wave in the 2006 Outburst of Recurrent Nova RS Ophiuchi  

Microsoft Academic Search

Near-infrared spectra are presented for the recent 2006 outburst of the recurrent nova RS Ophiuchi.We report the rare detection of an infrared shock wave as the nova ejecta plows into the preexisting wind of the secondary in the RS Oph system consisting of a white dwarf (WD) primary and a red giant secondary. The evolution of the shock is traced

Ramkrishna Das; Dipankar P. K. Banerjee; Nagarhalli M. Ashok

2006-01-01

329

The role of organizational culture in compliance with the principles of the 3Rs  

Microsoft Academic Search

In order for their research to be legitimate, scientists carrying out research using animals must comply with rules and regulations. The 3Rs (replacement, reduction and refinement) are one set of guidelines that help to promote the ethical use of animals for research. An important question is whether implementing the principles of the 3Rs in legal regulations, such as a Directive

Anne-Grethe Trønsdal Berg; Aurora Brønstad

2010-01-01

330

Vibration Measurements on Dissolution Systems and Effects on Dissolution of Prednisone Tablets RS  

Microsoft Academic Search

Efforts are being made by various groups (1, 2) to focus more on mechanical calibration as a potential replacement for Pred- nisone tablets RS (calibrator tablets). Although some mechanical calibration is currently performed (e.g., wobble, centering), the PhRMA committee's original proposal was to replace the Prednisone tablets RS through use of enhanced mechanical cali- bration. A collaborative study (3) executed

Saroj Vangani; Tawnya Flick; Germinia Tamayo; Rick Chiu; Nina Cauchon

331

Cultivated Land Change and Its Human Driving Forces Based on RS and GIS in Fuzhou, China  

Microsoft Academic Search

This paper analyzed the characteristics and major human driving forces of cultivated land change in Fuzhou, China, using remote sensing (RS) images, geographic information system (GIS) spatial analysis, and socio-economic data. Based on the RS images and GIS spatial analysis, a change matrix was constructed to detect land-use change from 1989 to 2005. The result indicated that paddy fields and

Dewen Wu; Jinchuan Huang; Xiaolei Zhang; Hanying Mao

2009-01-01

332

Syndrome of remitting seronegative symmetrical synovitis with pitting oedema (RS3PE).  

PubMed

RS3PE syndrome, often mimicking rheumatoid arthritis (RA) or polymyalgia rheumatica (PMR), has puzzled the rheumatologists until late'80s. Though the nature of the disease still remains illusive, the outcome is excellent. This present study analyzes the clinical, radiological and immunogenetical characteristics of five patients diagnosed with RS3PE syndrome, with review of literature. PMID:17598336

Kundu, A K

2007-03-01

333

Phospholipase C Epsilon 1 (PLCE1 rs2274223A>G, rs3765524C>T and rs7922612C>T) Polymorphisms and Esophageal Cancer Risk in the Kashmir Valley.  

PubMed

Background: Phospholipase C epsilon 1 (PLCE1) encodes a member of the phospholipase family of proteins that play crucial roles in carcinogenesis and progression of several cancers including esophageal cancer (EC). In two large scale genome-wide association studies (GWAS) single nucleotide polymorphisms (SNP, rs2274223A>G, rs3765524C>T) in PLCE1 were identified as novel susceptibility loci of esophageal cancer (EC) in China. The aim of the present study was to investigate this finding in Kashmir Valley, a high risk area. Materials and Methods: We determined genotypes of three potentially functional SNPs (rs2274223A>G, rs3765524C>T and rs7922612C>T) of PLCE1 in 135 EC patients, and 195 age and gender matched controls in Kashmiri valley by PCR RFLP method. Risk for developing EC was estimated by binary logistic regression using SPSS. Results: The selected PLCE1 polymorphisms did not show independent association with EC. However, the G2274223T3765524T7922612 haplotype was significantly associated with increased risk of EC (OR=2.92; 95% CI=1.30-6.54; p=0.009). Smoking and salted tea proved to be independent risk factors for EC. Conclusions: Genetic variations in PLCE1 modulate risk of EC in the high risk Kashmiri population. PMID:24935391

Malik, Manzoor Ahmad; Umar, Meenakshi; Gupta, Usha; Zargar, Showkat Ali; Mittal, Balraj

2014-01-01

334

Winds from Cool Stars  

Microsoft Academic Search

The structure of the outer atmospheres of luminous cool stars reveals the evolution of magnetic activity as dynamo heating decreases and atmospheres expand while the stars evolve across the color-magnitude diagram. The relationship between winds and high temperature material can also be investigated. A comprehensive picture of the dynamics of the outer atmospheres is constructed based principally upon recent spectroscopic

A. K. Dupree

2004-01-01

335

The North (Wall) Star  

NSDL National Science Digital Library

Celestial navigation is the art and science of finding one's geographic position by means of astronomical observations, particularly by measuring altitudes of celestial objects â sun, moon, planets or stars. This activity starts with a basic, but very important and useful, celestial measurement: measuring the altitude of Polaris (the North Star) or measuring the latitude.

Integrated Teaching And Learning Program

336

Science through ARts (STAR)  

ERIC Educational Resources Information Center

Science Through ARts (STAR) is a free, international, cross-curricular program thematically aligned with "The Vision for Space Exploration," a framework of goals and objectives published by NASA in February 2004. Through the STAR program, students in grades 5 through 12 are encouraged to apply their knowledge in creative ways as they approach a…

Densmore, Marycay; Kolecki, Joseph C.; Miller, Allan; Petersen, Ruth; Terrell, Mike

2005-01-01

337

Party with the Stars.  

ERIC Educational Resources Information Center

Describes a Star Party which involves comparing the different colors of the stars, demonstrating how astronomers measure the sky with degrees, determining the cardinal direction, discussing numerous stories that ancient civilizations gave to constellations, exercising science process skills, and using science instruments. (JRH)

Blaine, Lloyd

1997-01-01

338

The Violent Neutron Star  

NASA Astrophysics Data System (ADS)

Neutron stars enable us to study both the highest densities and the highest magnetic fields in the known Universe. In this article I review what can be learned about such fundamental physics using magnetar bursts. Both the instability mechanisms that trigger the bursts, and the subsequent dynamical and radiative response of the star, can be used to explore stellar and magnetospheric structure and composition.

Watts, A. L.

2012-12-01

339

Eclipsing Binary Stars  

NSDL National Science Digital Library

This site offers information about binary stars. There are many complex computations in this website along with other links to help explain the concepts. They are in the form of websites, articles, software, and visuals. Some of the topics include: a simple model for computing light curves, shape of a rotating star, and many more.

2004-07-17

340

Quarkonium at STAR.  

National Technical Information Service (NTIS)

The STAR detector is capable of reconstruction the J/(psi) meson in its dielectron decay channel, along with continuum dielectrons from heavy quark decay. The limitation is not instrumental--the ability of the STAR detector to identify electrons--rather, ...

T. J. LeCompte

1998-01-01

341

Nebraska STARS: Achieving Results  

ERIC Educational Resources Information Center

In 2000, the state of Nebraska passed legislation requiring the assessment of student performance on content standards, but its requirements were very different from those of any other state. Nebraska created what has come to be known as STARS (School-based Teacher-led Assessment and Reporting System). Under STARS, each of Nebraska's nearly 500…

Roschewski, Pat; Isernhagen, Jody; Dappen, Leon

2006-01-01

342

Neutron star models  

NASA Technical Reports Server (NTRS)

The current state of neutron star structure calculations is reviewed. Uncertainties in the equation of state for matter at and above nuclear density remain. The role of the delta resonance, pion condensates, and quark matter is reviewed. It is found that recent models yield stable neutron star masses which are consistent with observational estimates.

Canuto, V.; Bowers, R. L.

1981-01-01

343

Hyperons in neutron stars  

SciTech Connect

Generalized beta equilibrium involving nucleons, hyperons, and isobars is examined for neutron star matter. The hyperons produce a considerable softening of the equation of state. It is shown that the observed masses of neutron stars can be used to settle a recent controversy concerning the nuclear compressibility. Compressibilities less than 200 MeV are incompatible with observed masses. 7 refs., 9 figs.

Glendenning, N.K.

1986-04-01

344

Lives and Deaths of Stars  

NSDL National Science Digital Library

Stars live for a very long time compared to human lifetimes. Your great, great grandparents saw the same stars as you will see tonight (if it's clear). Our lifetimes are measured in years. Star lifetimes are measured in millions of years. Even though star timescales are enormous, it is possible to know how stars are born, live, and die. This chapter covers the stages a star will go through in its life and how it was figured out. The last part of the chapter will cover the remains of stars, white dwarfs, neutron stars, and the Hollywood favorite: black holes.

Strobel, Nick

2009-08-06

345

Variability of carbon stars  

NASA Astrophysics Data System (ADS)

The results of photographic monitoring of carbon stars situated in several regions near the galactic equator, carried out with the Schmidt telescope, are reported. Almost all stars with light range in red passband (0.63 micron) exceeding one magnitude turned out to be long-period variables. About 10 percent of all carbon stars have light range in V passband larger than two magnitudes. In most cases, variations of long-period carbon stars can be regarded as a sum of two components: periodical and secondary. The cycle length of the secondary component is between 2 to 10 cycles of the periodic component. Carbon stars with thick circumstellar dust shells have extremely long (about 600 days) periods and a steep ascending branch of light curve. In the blue-violet radiation of the object CIT 6 = RW LMi, the periodic component of variations is absent, although the light range of the secondary component and short time fluctuations are the largest.

Alksnis, A.

346

Activity Cycles in Stars  

NASA Technical Reports Server (NTRS)

Starspots and stellar activity can be detected in other stars using high precision photometric and spectrometric measurements. These observations have provided some surprises (starspots at the poles - sunspots are rarely seen poleward of 40 degrees) but more importantly they reveal behaviors that constrain our models of solar-stellar magnetic dynamos. The observations reveal variations in cycle characteristics that depend upon the stellar structure, convection zone dynamics, and rotation rate. In general, the more rapidly rotating stars are more active. However, for stars like the Sun, some are found to be inactive while nearly identical stars are found to be very active indicating that periods like the Sun's Maunder Minimum (an inactive period from 1645 to 1715) are characteristic of Sun-like stars.

Hathaway, David H.

2009-01-01

347

A VLA radio-continuum survey of a sample of confirmed and marginal barium stars  

NASA Technical Reports Server (NTRS)

Results are reported from a 6-cm VLA survey of five confirmed Ba II stars and eight mild Ba II stars, undertaken to search for evidence of gyrosynchrotron emission or thermal emission from the primary star's wind that is enhanced or photoionized by a white dwarf companion. Of these 13 stars, only Beta UMi was detected as a possible radio source at a flux level of 0.11 mJy (3sigma). The 6-cm radio luminosities (L6) of the other stars are as small as log L6 less than or equal to 14.0 and are an order of magnitude or more lower than the average levels found in RS CVn systems, but are consistent with the L6 upper limits previously found for stars of spectral type similar to the Ba II stars and normal elemental abundances. The upper limit to the radio luminosity for the possible mild Ba II star 56 Peg, when combined with its previously known X-ray luminosity, may provide useful constraints on the various models that have been proposed for this interesting object, once its orbital period is known.

Drake, Stephen A.; Simon, Theodore; Linsky, Jeffrey L.

1987-01-01

348

The ARIES-RS power core -- Recent development in Li/V designs  

SciTech Connect

The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirements. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design. This paper summarizes the power core design of the ARIES-RS power plant study.

Sze, D.K.; Billone, M.C.; Hua, T.Q. [and others

1997-04-01

349

RASSF1A and the rs2073498 Cancer Associated SNP  

PubMed Central

RASSF1A is one of the most frequently inactivated tumor suppressors yet identified in human cancer. It is pro-apoptotic and appears to function as a scaffolding protein that interacts with a variety of other tumor suppressors to modulate their function. It can also complex with the Ras oncoprotein and may serve to integrate pro-growth and pro-death signaling pathways. A SNP has been identified that is present in approximately 29% of European populations [rs2073498, A(133)S]. Several studies have now presented evidence that this SNP is associated with an enhanced risk of developing breast cancer. We have used a proteomics based approach to identify multiple differences in the pattern of protein/protein interactions mediated by the wild type compared to the SNP variant protein. We have also identified a significant difference in biological activity between wild type and SNP variant protein. However, we have found only a very modest association of the SNP with breast cancer predisposition.

Donninger, Howard; Barnoud, Thibaut; Nelson, Nick; Kassler, Suzanna; Clark, Jennifer; Cummins, Timothy D.; Powell, David W.; Nyante, Sarah; Millikan, Robert C.; Clark, Geoffrey J.

2011-01-01

350

Performance Characterization of RaPToRS Systems  

NASA Astrophysics Data System (ADS)

The Rapid Pneumatic Transport of Radioactive Samples (RaPToRS) system can quickly and efficiently move radioactive materials from their activation site to a counting station. Facilities such as the NIF and LLE are considering these systems while NRL is currently using one. The system is essentially a 10 cm diameter pneumatic tube with a cylindrical sample carrier. The performance of the system depends on many factors, including the mass of the carrier, length of the tube, angle and difference in height of the tube's endpoints, the carrier's physical design, and the number, type, and distribution of blowers attached to the tube. These factors have been systematically examined to develop the fastest and most reliable system. The most significant factors are the mass and the vertical travel of the carrier. When the carrier mass is low, moving air supports the carrier in the tube, resulting in low friction. The terminal velocity ranges from 13.5 to 2.5 m/s for masses varying from 1 kg to 3 kg. Using a single 1100 W blower, the initial force exerted on the carrier was 11.3 N.

Shibata, K.; Krieger, M.; Fallica, J.; Henchen, R.; Pogozelski, E.; Padalino, S.

2011-11-01

351

Rapid Pneumatic Transport of Radioactive Samples - RaPToRS  

NASA Astrophysics Data System (ADS)

Some ICF neutron activation diagnostics require quick retrieval of the activated sample. Minimizing retrieval times is particularly important when the half-life of the activated material is on the order of the transport time or the degree of radioactivity is close to the background counting level. These restrictions exist in current experiments performed at the Laboratory for Laser Energetics, thus motivating the development of the RaPToRS system. The system has been designed to minimize transportation time while requiring no human intervention during transport or counting. These factors will be important if the system is to be used at the NIF where radiological hazards will be present during post activation. The sample carrier is pneumatically transported via a 4 inch ID PVC pipe to a remote location in excess of 100 meters from the activation site at a speed of approximately 7 m/s. It arrives at an end station where it is dismounted robotically from the carrier and removed from its hermetic package. The sample is then placed by the robot in a counting station. This system is currently being developed to measure back-to-back gamma rays produced by positron annihilation which were emitted by activated graphite. Funded in part by the U.S. DOE under sub contract with LLE at the University of Rochester.

Padalino, S.; Barrios, M.; Sangster, C.

2005-10-01

352

The rs3768777-G allele of ITGAV gene is associated with rheumatoid arthritis.  

PubMed

Integrin ?v?3 (vitronectin receptor) plays a prominent role in angiogenesis, a key pathogenic feature of rheumatoid arthritis (RA). Moreover, integrin ?V (ITGAV) subunit gene has been associated with a susceptibility to RA. The aim of the present study was to detect the potential association between ITGAV gene polymorphisms and a susceptibility to RA in a Turkish cohort. DNA samples were harvested from 160 patients with RA and 144 healthy controls (HC). Three single-nucleotide polymorphisms of ITGAV gene (rs3738919, rs3768777, and rs10174098) were genotyped using real-time PCR. Serum vitronectin levels were analyzed in 30 RA patients, 28 Behçet's disease (BD) patients, and 30 HC subjects. There was no significant difference between the RA and HC groups in terms of the genotypic and allelic distributions of rs3738919 and rs10174098 polymorphisms. However, the prevalence of rs3768777-G allele was higher in the RA group than in the HC group (OR 2.3, 95 % CI 1.6-3.2, p < 0.0001). Moreover, there was a significant association between RA and the genotypic distribution of rs3768777 (GG + AG vs. AA: OR 2.1, 95 % CI 1.3-3.4; GG vs. AG + AA: OR 4.1, 95 % CI 2.1-7.8). Serum vitronectin levels were lower in the RA and BD groups than in the HC group (p ANOVA = 0.002). The rs3738919 and rs10174098 polymorphisms of the ITGAV gene seem not to be associated with susceptibility to RA in Turkish patients. However, rs3768777 increases the risk of RA in this group. These results suggest that the ITGAV gene may be a candidate gene for the etiopathogenesis of RA. PMID:24375314

Koca, Suleyman Serdar; Kara, Murat; Ozgen, Metin; Dagli, Mustafa Necati; Gozel, Nevzat; Yolbas, Servet; Gundogdu, Baris; Kargun, Kursat; Isik, Ahmet

2014-05-01

353

Accuracy Assessment and Correction of Vaisala RS92 Radiosonde Water Vapor Measurements  

NASA Technical Reports Server (NTRS)

Relative humidity (RH) measurements from Vaisala RS92 radiosondes are widely used in both research and operational applications, although the measurement accuracy is not well characterized as a function of its known dependences on height, RH, and time of day (or solar altitude angle). This study characterizes RS92 mean bias error as a function of its dependences by comparing simultaneous measurements from RS92 radiosondes and from three reference instruments of known accuracy. The cryogenic frostpoint hygrometer (CFH) gives the RS92 accuracy above the 700 mb level; the ARM microwave radiometer gives the RS92 accuracy in the lower troposphere; and the ARM SurTHref system gives the RS92 accuracy at the surface using 6 RH probes with NIST-traceable calibrations. These RS92 assessments are combined using the principle of Consensus Referencing to yield a detailed estimate of RS92 accuracy from the surface to the lowermost stratosphere. An empirical bias correction is derived to remove the mean bias error, yielding corrected RS92 measurements whose mean accuracy is estimated to be +/-3% of the measured RH value for nighttime soundings and +/-4% for daytime soundings, plus an RH offset uncertainty of +/-0.5%RH that is significant for dry conditions. The accuracy of individual RS92 soundings is further characterized by the 1-sigma "production variability," estimated to be +/-1.5% of the measured RH value. The daytime bias correction should not be applied to cloudy daytime soundings, because clouds affect the solar radiation error in a complicated and uncharacterized way.

Whiteman, David N.; Miloshevich, Larry M.; Vomel, Holger; Leblanc, Thierry

2008-01-01

354

DNA repair gene XRCC7 polymorphisms (rs#7003908 and rs#10109984) and hepatocellular carcinoma related to AFB1 exposure among Guangxi population, China.  

PubMed

Aim:? The X-ray repair cross-complementing group 7 (XRCC7) plays an important role in the repair of DNA double-strand breaks by nonhomologous end-joining repair (NEJR) pathway. However, the role of XRCC7 polymorphisms (rs#7003908 and rs#10109984) possibly influencing NEJR capacity in hepatocellular carcinoma (HCC) induced by aflatoxin B1 (AFB1) has not been well elaborated. Methods:? This hospital-based case-control study, including 348 patients with newly diagnosed HCC and 597 controls without any evidence of liver diseases, was conducted to elucidate the association between these two polymorphisms and the risk of HCC related to AFB1 exposure among a Guangxi population from a high AFB1-exposure area by means of TaqMAN-polymerase chain reaction technique. Results:? We observed that HCC patients featured higher AFB1 exposure than control group (odds ratios [OR]?=?6.49 and 6.75 for exposure years and exposure levels, respectively). Furthermore, these individuals with the genotypes of XRCC7 rs#7003908 G alleles (namely XRCC7-TG or -GG), compared the homozygote of XRCC7 rs#7003908 T alleles (XRCC7-TT), faced increasing risk of HCC (OR, 3.45 and 5.04; 95% confidence intervals [CIs], 2.40-4.94 and 3.28-7.76, respectively). We also found some evidence that this polymorphism interacted with AFB1-expousure years or levels in the process of HCC carcinogenesis. Additionally, XRCC7 rs#7003908 polymorphism was correlated with the levels of AFB1-DNA adducts (r?=?0.142, P?rs#10109984 polymorphism, however, did not modify the risk of HCC related to AFB1 exposure (P?>?0.05). Conclusion:? These data suggest that XRCC7 rs#7003908 polymorphism may be one of the genetic modifiers for AFB1-related HCC among Guangxi population. PMID:21883743

Long, Xi-Dai; Yao, Jin-Guang; Huang, Yong-Zhi; Huang, Xiao-Ying; Ban, Fu-Zhi; Yao, Li-Ming; Fan, Lu-Dan

2011-11-01

355

The ? Orionis Star Forming Region  

NASA Astrophysics Data System (ADS)

Around the O8 star ? Orionis is a highly evolved star-forming region, comprising recently formed stars from 0.2 M?Mar to 24 M?Mar and dark clouds actively forming stars, all within a 30-pc radius ring of dust and neutral and molecular hydrogen. The spatial and age distributions of the stars show that originally star formation occurred in an elongated giant molecular cloud, with the most massive stars forming in a dense central core. A supernova is suggested as the mechanism that terminated star formation in that core and formed the surrounding ring. Star formation continues in remnant dark clouds distant from the original core. The local initial mass functions differ significantly across the region, although the global IMF is field-like. Interestingly, the lack of H? emission in stars near ? Ori indicates that the environment of the massive stars was not conducive for the survival of accretion disks.

Mathieu, R. D.

2008-12-01

356

Computational Star Formation (IAU S270)  

NASA Astrophysics Data System (ADS)

1. Historical introduction; 2. Individual star formation: observations; 3. Low-mass star formation: observations; 4. Individual star formation: theory; 5. Formation of clusters: observations; 6. Formation of clusters: theory; 7. Numerical methods: MHD; 8. Numerical methods: radiative dynamics; 9. Local star formation processes; 10. Star formation feedback; 11. Star formation on galactic scales; 12. Special purpose hardware; 13. Computational methods; 14. Radiation diagnostics of star formation; 15. Large scale star formation; 16. Cosmological star formation; 17. Computational star formation: Summary; Index.

Alves, João.; Elmegreen, Bruce G.; Girart, Josep M.; Trimble, Virginia

2011-05-01

357

The rs1024611 Regulatory Region Polymorphism Is Associated with CCL2 Allelic Expression Imbalance  

PubMed Central

CC chemokine ligand 2 (CCL2) is the most potent monocyte chemoattractant and inter-individual differences in its expression level have been associated with genetic variants mapping to the cis-regulatory regions of the gene. An A to G polymorphism in the CCL2 enhancer region at position –2578 (rs1024611; A>G), was found in most studies to be associated with higher serum CCL2 levels and increased susceptibility to a variety of diseases such as HIV-1 associated neurological disorders, tuberculosis, and atherosclerosis. However, the precise mechanism by which rs1024611influences CCL2 expression is not known. To address this knowledge gap, we tested the hypothesis that rs1024611G polymorphism is associated with allelic expression imbalance (AEI) of CCL2. We used haplotype analysis and identified a transcribed SNP in the 3?UTR (rs13900; C>T) can serve as a proxy for the rs1024611 and demonstrated that the rs1024611G allele displayed a perfect linkage disequilibrium with rs13900T allele. Allele-specific transcript quantification in lipopolysaccharide treated PBMCs obtained from heterozygous donors showed that rs13900T allele were expressed at higher levels when compared to rs13900C allele in all the donors examined suggesting that CCL2 is subjected to AEI and that that the allele containing rs1024611G is preferentially transcribed. We also found that AEI of CCL2 is a stable trait and could be detected in newly synthesized RNA. In contrast to these in vivo findings, in vitro assays with haplotype-specific reporter constructs indicated that the haplotype bearing rs1024611G had a lower or similar transcriptional activity when compared to the haplotype containing rs1024611A. This discordance between the in vivo and in vitro expression studies suggests that the CCL2 regulatory region polymorphisms may be functioning in a complex and context-dependent manner. In summary, our studies provide strong functional evidence and a rational explanation for the phenotypic effects of the CCL2 rs1024611G allele.

Pham, Minh-Hieu T.; Bonello, Gregory B.; Castiblanco, John; Le, Tuan; Sigala, Jose; He, Weijing; Mummidi, Srinivas

2012-01-01

358

Making star teams out of star players.  

PubMed

Top talent is an invaluable asset: In highly specialized or creative work, for instance, "A" players are likely to be six times as productive as "B" players. So when your company has a crucial strategic project, why not multiply all that firepower and have a team of your best performers tackle it? Yet many companies hesitate to do this, believing that all-star teams don't work: Big egos will get in the way. The stars won't be able to work with one another. They'll drive the team Leader crazy. Mankins, Bird, and Root of Bain & Company believe it's time to set aside that thinking. They have seen all-star teams do extraordinary work. But there is a right way and a wrong way to organize them. Before you can even begin to assemble such a team, you need to have the right talent management practices, so you hire and develop the best people and know what they're capable of. You have to give the team appropriate incentives and leaders and support staffers who are stars in their own right. And projects that are ill-defined or small scale are not for all-star teams. Use them only for critical missions, and make sure their objectives are clear. Even with the right setup, things can still go wrong. The wise executive will take steps to manage egos, prune non-team-players, and prevent average coworkers from feeling completely undervalued. She will also invest a lot of time in choosing the right team Leader and will ask members for lots of feedback to monitor how that leader is doing. PMID:23390743

Mankins, Michael; Bird, Alan; Root, James

2013-01-01

359

Hot Subdwarf Stars  

NASA Astrophysics Data System (ADS)

Hot subdwarf stars (sdBs, sdOs) are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. They are found in all Galactic stellar populations and are sufficiently common to account for the UV-upturn of early-type galaxies. About half of the sdBs reside in close binaries; companions are white dwarfs or low-mass main-sequence stars. Binary population-synthesis models explain naturally the actual sdB binary fractions of field and globular cluster stars as well as of He-sdOs if white-dwarf mergers are considered. Hot helium flashes explain the chemical composition of He-sdOs. Asteroseismology of a dozen pulsating sdB stars allowed determination of their masses and detection of a planet to V391 Peg. The discoveries of an sdO star unbound to the Galaxy, potential SN Ia progenitors and probably a hidden population of neutron stars or black hole companions have great impact on astrophysics at large.

Heber, Ulrich

2009-09-01

360

Measuring stars with Gaia  

NASA Astrophysics Data System (ADS)

Beyond the extraordinary three dimensional map that Gaia will create for a billion of stars, it will reveal the origin and history of the Milky Way as the major goal. This does not weakness the fantastic impact of Gaia on the stellar physic. It will put constraints on the modeling of stars to an extreme that consequently new input physics will be mandatory to understand a Gaia HR diagram. Stars are formed in populations and evolve as collection of objects revealing important clues on how they formed, what kind of mass function is active during the star formation, how frequent is the star formation, all of this is imprinted in the intrinsic properties of stars that large surveys combined together like Gaia, Kepler, PLATO will revealed. The characterization of stars hosting planets is also a goal of such combination of large surveys and in particular of the measure of distances in the Galaxy. The launch of Gaia is for November of 2013 and the output catalogue is expected for 2020. Then will start the beginning of a new Astrophysics touching so many topics that a new age of astrophysics is then foreseen.

Thévenin, F.

2013-12-01

361

Spectroscopy of ? Doradus stars  

NASA Astrophysics Data System (ADS)

The musician programme at the University of Canterbury has been successfully identifying pulsation modes in many ? Doradus stars using hundreds of ground-based spectroscopic observations. This paper describes some of the successful mode identifications and emerging patterns of the programme. The hybrid ? Doradus/? Scuti star HD 49434 remains an enigma, despite the analysis of more than 1700 multi-site high-resolution spectra. A new result for this star is apparently distinct line-profile variations for the ? Doradus and ? Scuti frequencies.

Brunsden, E.; Pollard, K. R.; Cottrell, P. L.; Wright, D. J.; De Cat, P.; Kilmartin, P. M.

2014-02-01

362

Kepler Star Wheels  

NSDL National Science Digital Library

This is a make-it-yourself planisphere designed to show where Kepler is pointing. Learners can use it to locate exoplanets around stars in the night sky. It comes with two wheels: one with coordinate grid for plotting additional exoplanet stars and one without grid that is easier to read; and two holders for varying latitudes (one for 30°-50° and one for 50°-70°). The product is updated approximately annually to incorporate improvements and any newly discovered planets orbiting naked eye stars.

363

StarDate Online  

NSDL National Science Digital Library

This on-line version of StarDate astronomy magazine provides current viewing information, a sky almanac, Moon phase calculator, sunrise and sunset calculator, planet viewing information, and meteor shower updates. News and Features contains information and details on the latest findings and research in the field of astronomy. Resources contains an image gallery, an astroglossary, and solar system, constellation, and star guides. The Radio section contains past radio programs by date, or searchable by subject. Also available are an archive database of past StarDate articles, and a teacher's section with ideas for teaching astronomy concepts in the classroom.

364

VV Cephei Type Stars  

NASA Astrophysics Data System (ADS)

Three new VV Cephei-type stars were discovered by Barbier (1971). We propose to observe these systems to detect and characterize the continuum of the companion and to investigate emission lines from the cool M star and/or by circumstellar material. One star (BD+63 0003) has been monitored extensively by one of the investigators (EFG) and observations would be scheduled about 6 to 9 months apart to coincide with maximum and minimum light in order to detect any dependence of emission activity or interaction with the hot component on the pulsations of the M supergiant component.

Shaw, J. Scott

1984-07-01

365

Modeling of Be Stars  

NASA Astrophysics Data System (ADS)

Be stars are still a big unknown in respect of origin and geometry of circumstellar disk around a star. The program shellspec is designed to solve a simple radiative transfer along the line of sight in three-dimensional moving media, so it is able to compute synthetic spectrum for our case (a star with a disk). Our goal was to develop an effective method to search in parameter space which can allow us to find a good estimate of physical parameters of the disk.

Šejnová, K.; Votruba, V.; Koubská, P.

2012-12-01

366

On the conversion of neutron stars into quark stars  

NASA Astrophysics Data System (ADS)

The possible existence of two families of compact stars, neutron stars and quark stars, naturally leads to a scenario in which a conversion process between the two stellar objects occurs with a consequent release of energy of the order of 1053 erg. We discuss recent hydrodynamical simulations of the burning process and neutrino diffusion simulations of cooling of a newly formed strange star. We also briefly discuss this scenario in connection with recent measurements of masses and radii of compact stars.

Pagliara, Giuseppe

2014-03-01

367

Association of HSPA1B SNP rs6457452 with Alopecia Areata in the Korean population.  

PubMed

The heat shock 70?kDa protein 1B (HSPA1B), which has been well-studied among the famous heat shock proteins HSPA1A/B/L, is related to autoimmune diseases, including Alopecia Areata (AA). In this study, the association of a 5'-untranslated region (5'UTR) SNP rs6457452 and a promoter SNP rs2763979 (-1140C?>?T) of HSPA1B with AA was investigated in 236 controls and 228 AA patients. Statistical analyses using the multiple logistic models were done, according to the onset and the clinical features of AA, including the age of onset, family history, type of AA lesion, nail involvement and body hair involvement. The results showed that rs6457452 was associated with the onset of AA (p?rs6457452 was weakly related to the age of onset (p???0.04) and that rs2763979 was only weakly related to the type of AA lesion (p?=?0.041). In conclusion, we suggest that the 5'UTR SNP rs6457452 of HSPA1B may be associated with the onset of AA and the T allele of rs6457452 may confer the reduced susceptibility to AA in the Korean population. PMID:24303776

Seok, Hosik; Jeon, Hye Sook; Park, Hae Jeong; Kim, Su Kang; Choi, Jeong Hwee; Lew, Bark-Lynn; Chung, Joo-Ho; Sim, Woo-Young

2014-01-01

368

Meta-Analysis of Low Density Lipoprotein Receptor (LDLR) rs2228671 Polymorphism and Coronary Heart Disease  

PubMed Central

Low density lipoprotein receptor (LDLR) can regulate cholesterol metabolism by removing the excess low density lipoprotein cholesterol (LDL-C) in blood. Since cholesterol metabolism is often disrupted in coronary heart disease (CHD), LDLR as a candidate gene of CHD has been intensively studied. The goal of our study is to evaluate the overall contribution of LDLR rs2228671 polymorphism to the risk of CHD by combining the genotyping data from multiple case-control studies. Our meta-analysis is involved with 8 case-control studies among 7588 cases and 9711 controls to test the association between LDLR rs2228671 polymorphism and CHD. In addition, we performed a case-control study of LDLR rs2228671 polymorphism with the risk of CHD in Chinese population. Our meta-analysis showed that rs2228671-T allele was significantly associated with a reduced risk of CHD (P = 0.0005, odds ratio (OR)?=?0.83, and 95% confidence interval (95% CI)?=?0.75–0.92). However, rs2228671-T allele frequency was rare (1%) and was not associated with CHD in Han Chinese (P = 0.49), suggesting an ethnic difference of LDLR rs2228671 polymorphism. Meta-analysis has established rs2228671 as a protective factor of CHD in Europeans. The lack of association in Chinese reflects an ethnic difference of this genetic variant between Chinese and European populations.

Ye, Huadan; Zhao, Qianlei; Huang, Yi; Wang, Lingyan; Liu, Haibo; Wang, Chunming; Dai, Dongjun; Xu, Leiting; Ye, Meng; Duan, Shiwei

2014-01-01

369

Rs12218 In SAA1 gene was associated with serum lipid levels  

PubMed Central

Background Serum amyloid A (SAA) is a kind of apolipoprotein. Several studies indicated that SAA genetic polymorphism rs12218 was associated with carotid atherosclerosis, peripheral arterial disease, and serum uric acid levels. However, the relation between rs12218 and lipid levels remains unclear. This study assessed the correlation between SAA1 gene rs12218 polymorphism and lipid levels in a Chinese population. Methods A total of 823 participants were selected from the subjects for health check in Shanghai Huashan hospital from Jan. 2013 to Mach. 2013. Correlations between rs12218 polymorphism and lipid levels were investigated through the identification of rs12218 genotypes using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results We found that the SNP rs12218 was associated with triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL-C) levels by analyses of a dominant model (P<0.001, P=0.002, P=0.003, respectively), a recessive model (P <0.001, P=0.001, P=0.005, respectively) and an additive model (P < 0.001, P=0.001, P=0.002, respectively), and the difference remained significant after the adjustment of sex, age, alcohol intake, and smoking (All P < 0.01). Conclusion Our results indicated that the rs12218 in the SAA1gene was associated with lipid levels in a Chinese population.

2013-01-01

370

SNP rs3825214 in TBX5 Is Associated with Lone Atrial Fibrillation in Chinese Han Population  

PubMed Central

Background A prolonged PR interval is a sign of increased risk of cardiac arrhythmia. Recent genome-wide association studies found that the single-nucleotide polymorphism (SNP) rs3825214 in T-box 5 (TBX5) was positively associated with PR interval, QRS duration, QT interval, and common arrhythmia disorders such as atrial fibrillation (AF) and advanced atrioventricular block. However, other independent replication studies are required to validate the result. This study assessed associations between rs3825214 and ECG parameters, AF, and ventricular tachycardia (VT) in a Chinese Han population. Methodology/Principal Findings To assess the association between rs3825214 and AF and VT, we carried out case-control association studies with 692 AF patients (including 275 lone AF patients), 235 VT patients, and 856 controls. Genotyping was performed using a Rotor-Gene TM 6000 High Resolution Melt system. Statistical analyses of associations were adjusted for potential confounding factors. A moderate association was detected between rs3825214 and AF (Padj?=?0.036, OR?=?0.79) and a highly significant association was detected between the G allele of rs3825214 and lone AF (Padj?=?0.001, OR?=?0.65; genotypic P?=?3.75×10?4 with a dominant model). We also found that rs3825214 showed a significant association with atrial-ventricular block (AVB; P?=?0.028; Padj?=?0.035, OR?=?0.494). Conclusions Our results indicate that rs3825214 conferred a significant risk of lone AF in this Chinese Han population.

Li, Sisi; Fu, Fenfen; Li, Xiuchun; Wang, Fan; Zhang, Rongfeng; Tian, Xiaochen; Gao, Lianjun; Zhang, Jiaying; Yang, Yanzong; Tu, Xin; Wang, Qing

2013-01-01

371

The Constellations and their Stars  

NSDL National Science Digital Library

This website is a tutorial on constellations and the stars in them. It offers an alphabetical and monthly listing of the constellations. It also provides a listing of stars, messier objects, and a list of the brightest stars in the sky. The user can also use the website's interactive star chart, Milky Way photos, or helpful links.

Dolan, Chris

2005-05-15

372

The achievement of the bidirectional signal transformation between IEEE488 and RS232 with single chip processor  

Microsoft Academic Search

The achievement of the bi-directional signal transformation between IEEE488 and RS-232 with single chip processor is presented. Meanwhile, the structure of IEEE488 and RS-232, the corresponding hardware circuits and program modules are provided.

Ying Xiang; Xiuzhong Zhang; Congxin Zhu

2001-01-01

373

The LRP6 rs2302685 polymorphism is associated with increased risk of myocardial infarction  

PubMed Central

Background Abnormal lipids is one of the critical risk factors for myocardial infarction (MI), however the role of genetic variants in lipid metabolism-related genes on MI pathogenesis still requires further investigation. We herein genotyped three SNPs (LRP6 rs2302685, LDLRAP1 rs6687605, SOAT1 rs13306731) in lipid metabolism-related genes, aimed to shed light on the influence of these SNPs on individual susceptibility to MI. Methods Genotyping of the three SNPs (rs2302685, rs6687605 and rs13306731) was performed in 285 MI cases and 650 control subjects using polymerase chain reaction–ligation detection reaction (PCR–LDR) method. The association of these SNPs with MI and lipid profiles was performed with SPSS software. Results Multivariate logistic regression analysis showed that C allele (OR?=?1.62, P?=?0.039) and the combined CT/CC genotype (OR?=?1.67, P?=?0.035) of LRP6 rs2302685 were associated with increased MI risk, while the other two SNPs had no significant effect. Further stratified analysis uncovered a more evident association with MI risk among younger subjects (?60 years old). Fascinatingly, CT/CC genotype of rs2302685 conferred increased LDL-C levels compared to TT genotype (3.0 mmol/L vs 2.72 mmol/L) in younger subjects. Conclusions Our data provides the first evidence that LRP6 rs2302685 polymorphism is associated with an increased risk of MI in Chinese subjects, and the association is more evident among younger individuals, which probably due to the elevated LDL-C levels.

2014-01-01

374

MicroRNAs and their isomiRs function cooperatively to target common biological pathways  

PubMed Central

Background Variants of microRNAs (miRNAs), called isomiRs, are commonly reported in deep-sequencing studies; however, the functional significance of these variants remains controversial. Observational studies show that isomiR patterns are non-random, hinting that these molecules could be regulated and therefore functional, although no conclusive biological role has been demonstrated for these molecules. Results To assess the biological relevance of isomiRs, we have performed ultra-deep miRNA-seq on ten adult human tissues, and created an analysis pipeline called miRNA-MATE to align, annotate, and analyze miRNAs and their isomiRs. We find that isomiRs share sequence and expression characteristics with canonical miRNAs, and are generally strongly correlated with canonical miRNA expression. A large proportion of isomiRs potentially derive from AGO2 cleavage independent of Dicer. We isolated polyribosome-associated mRNA, captured the mRNA-bound miRNAs, and found that isomiRs and canonical miRNAs are equally associated with translational machinery. Finally, we transfected cells with biotinylated RNA duplexes encoding isomiRs or their canonical counterparts and directly assayed their mRNA targets. These studies allow us to experimentally determine genome-wide mRNA targets, and these experiments showed substantial overlap in functional mRNA networks suppressed by both canonical miRNAs and their isomiRs. Conclusions Together, these results find isomiRs to be biologically relevant and functionally cooperative partners of canonical miRNAs that act coordinately to target pathways of functionally related genes. This work exposes the complexity of the miRNA-transcriptome, and helps explain a major miRNA paradox: how specific regulation of biological processes can occur when the specificity of miRNA targeting is mediated by only 6 to 11 nucleotides.

2011-01-01

375

An X-ray survey for pre-main-sequence stars in the Taurus-Auriga and Perseus molecular cloud complexes  

NASA Technical Reports Server (NTRS)

Seventy-five fields from the Einstein X-Ray Observatory IPC detector between 3h and 5h right ascension and 15 deg and 35 deg declination are examined to search for X-ray-emitting low-mass pre-main-sequence (PMS) stars. Six such stars were previously found; they appear to be similar to T Tauri stars but without dense circumstellar envelopes or winds. Finding charts are presented for 59 X-ray sources that may be PMS stars. While some are likely to be spurious X-ray sources, chance coincidences with unrelated stars, or non-PMS stellar sources such as RS CVn type binaries, approximately half are probably X-ray-selected PMS stars.

Feigelson, E. D.; Jackson, J. M.; Mathieu, R. D.; Myers, P. C.; Walter, F. M.

1987-01-01

376

[RS3PE syndrome: an acute edematous polyarthritis of the elderly with variable prognosis].  

PubMed

The RS3PE syndrome or subacute edematous polyarthritis of the elderly remains a doubtful entity. We report three cases that exhibited different courses: complete recovery, definite rheumatoid polyarthritis, and chronicity as a sign of myelodysplasic disease. These three different courses raise the question of whether RS3PE is a disease or a syndrome. Actually, the use of the term RS3PE syndrome should be restricted to cases with a favorable outcome. Definitive diagnosis thus cannot be reached before complete recovery. PMID:11474377

Beyne-Rauzy, O; Revel, V; Desfossez, V; Bousquet, E; Nourhashemi, F; Adoue, D

2001-06-01

377

RS-34 (Peacekeeper Post Boost Propulsion System) Orbital Debris Application Concept Study  

NASA Technical Reports Server (NTRS)

The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) lead a study to evaluate the Rocketdyne produced RS-34 propulsion system as it applies to an orbital debris removal design reference mission. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Concept Study, preceded by a utilization study to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions, sought to further understand application for an orbital debris design reference mission as the orbital debris removal mission was found to closely mimic the heritage RS-34 mission. The RS-34 Orbital Debris Application Concept Study sought to identify multiple configurations varying the degree of modification to trade for dry mass optimization and propellant load for overall capability and evaluation of several candidate missions. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper.

Esther, Elizabeth A.; Burnside, Christopher G.

2013-01-01

378

Cool luminous stars  

NASA Technical Reports Server (NTRS)

The consequences of magnetic fields for the atmospheres of cool stars are addressed based on IUE and Einstein Observatory observations. Gross atmospheric structure data for cool luminous stars are discussed, and the relevance of the observations for the energy balance and nonradiative heating rates is considered. Data from X-ray fluxes, low dispersion UV spectra, and high dispersion spectra in the region of the Mg II resonance lines are presented. New results on cool star atmospheres provided by high dispersion UV spectra are considered, including those pertaining to spectral line identification, identification of emission components in close binary systems, densities and atmospheric extension, emission line widths, properties of stellar winds as derived from IUE data, and systematic flows of transition region plasma. An explanation for the observed spectra of cool giants and supergiants is proposed in terms of active, quiet, and hybrid stars.

Linsky, J. L.

1982-01-01

379

Winds from cool stars  

NASA Technical Reports Server (NTRS)

Spectral observations of cool stars enable study of the presence and character of winds and the mass loss process in objects with effective temperatures, gravities, and atmospheric compositions which differ from that of the Sun. A wealth of recent spectroscopic measurements from the Hubble Space Telescope, and the Extreme Ultraviolet Explorer complement high resolution ground-based measures in the optical and infrared spectral regions. Such observations when combined with realistic semi-empirical atmospheric modeling allow us to estimate the physical conditions in the atmospheres and winds of many classes of cool stars. Line profiles support turbulent heating and mass motions. In low gravity stars, evidence is found for relatively fast (approximately 200 km s(exp -1)), warm winds with rapid acceleration occurring in the chromosphere. In some cases outflows commensurate with stellar escape velocities are present. Our current understanding of cool star winds will be reviewed including the implications of stellar observations for identification of atmospheric heating and acceleration processes.

Dupree, A. K.

1995-01-01

380

Astrophysics: Twinkling stars  

NASA Astrophysics Data System (ADS)

A correlation between stellar brightness variations and the gravitational acceleration at a star's surface has been observed that allows this acceleration to be measured with a precision of better than 25%. See Letter p.427

Christensen-Dalsgaard, Jørgen

2013-08-01

381

Detector limitations, STAR.  

National Technical Information Service (NTIS)

Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR (Solenoidal Tracker At RHIC) were in place, these factors would not seriously li...

D. G. Underwood

1998-01-01

382

Women and the Stars.  

ERIC Educational Resources Information Center

Described are the contributions of 15 women astronomers to the modern understanding of the stars. Discussed are early women pioneers, early spectrographic studies, and recent women astronomers. A list of 29 references is included. (CW)

Spradley, Joseph L.

1990-01-01

383

Variable star data online  

NASA Astrophysics Data System (ADS)

Roger Pickard, Andy Wilson and Gary Poyner describe the online database of the British Astronomical Association Variable Star Section, a treasure trove of observations stretching back nearly 125 years.

Pickard, Roger; Wilson, Andy; Poyner, Gary

2012-06-01

384

Which stars have planets?  

NASA Technical Reports Server (NTRS)

The question of predicting which stars have planetary systems is discussed, with special attention given to the work of Nakano (1988), who combined scaling arguments with his theory (Nakano, 1987) of formation of planets in the solar system to estimate planetary growth rates around stars of various masses. It is argued that, in addition to stellar mass, the process of planet formation depends on other parameters, such as angular momentum and collisions. The existence of binary and multiple star systems of varying type demonstrates that angular momentum variations can play a crucial role, while the fact that the solar system has four giant planets and four terrestrial planets is considered to be due to the effects of random impacts and scatterings. It is concluded that, at present, the concept of determining what types of planetary systems are to be expected about stars of varying masses cannot be resolved.

Lissauer, J. J.

1989-01-01

385

Sleeping under the stars  

NASA Astrophysics Data System (ADS)

Sherlock Holmes and Dr. Watson went on a camping trip. As they lay down for the night, Holmes said, “Watson, look up at the sky and tell me what you see.”Watson:“! see millions and millions of stars.”

Zirkel, Jack

386

Planets Around Neutron Stars  

NASA Technical Reports Server (NTRS)

The objective of this proposal was to continue investigations of neutron star planetary systems in an effort to describe and understand their origin, orbital dynamics, basic physical properties and their relationship to planets around normal stars. This research represents an important element of the process of constraining the physics of planet formation around various types of stars. The research goals of this project included long-term timing measurements of the planets pulsar, PSR B1257+12, to search for more planets around it and to study the dynamics of the whole system, and sensitive searches for millisecond pulsars to detect further examples of old, rapidly spinning neutron stars with planetary systems. The instrumentation used in our project included the 305-m Arecibo antenna with the Penn State Pulsar Machine (PSPM), the 100-m Green Bank Telescope with the Berkeley- Caltech Pulsar Machine (BCPM), and the 100-m Effelsberg and 64-m Parkes telescopes equipped with the observatory supplied backend hardware.

Wolszczan, Alexander; Kulkarni, Shrinivas R; Anderson, Stuart B.

2003-01-01

387

Galactic and extragalactic star formation  

SciTech Connect

This book present new technology that allows the linking of the physics of local star forming regions to the global star forming properties of galaxies. Galactic star formation and examination of the processes of formation of nearby stars are addressed. Focus is on bipolar outflows and circumstellar disks. Larger scale phenomena in molecular clouds are then discussed, followed by reviews of star formation across the Milky Way.

Pudritz, R.E. (Minnesota Univ., Minneapolis, MN (USA). Heat Transfer Lab.); Fich, M. (Waterloo Univ., ON (Canada))

1988-01-01

388

SPATIAL ECONOMETRIC STAR MODELS  

Microsoft Academic Search

Spatial regression models incorporating non-stationarity in the regression coefficients are popular. In this paper we propose a family of spatial Smooth Transition AutoRegressive (STAR) models inspired by analogous nonlinear approaches developed in the time series literature. Spatial STAR models constitute a parsimonious, easy-to-estimate approach to modeling nonlinear spatial parameter variation and endogenous detection of spatial regimes. A distinct advantage of

Raymond J. G. M. Florax; Valerien O. Pede; Matthew T. Holt

389

Jars of Stars  

NSDL National Science Digital Library

This math activity uses stars, jars, and scoops to help learners build their estimation and volume skills. As you play, estimate how many scoops of stars it will take to fill a variety of jars. This activity helps learners estimate, predict, reason, strategize, measure volumes, multiply, divide and practice fractions. The activity guide contains a material list, sample questions to ask, literary connections, extensions, and alignment to local and national standards.

Houston, Children'S M.

2014-04-07

390

The first stars  

NASA Astrophysics Data System (ADS)

The possible nature of the first generation of stars is considered, using a star of 25 Msolar as an example. General nucleosynthesis and the production of CNO catalysts is examined in detail. The increase in neutron excess and its significance for yields from explosive burning is discussed. An estimate of the ratio of ionizing photons to heavy elements produced is derived, for use in early universe simulations.

Arnett, David

391

Chaotic Star Birth  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Click on the image for Poster VersionClick on the image for IRAS 4B Inset

Located 1,000 light years from Earth in the constellation Perseus, a reflection nebula called NGC 1333 epitomizes the beautiful chaos of a dense group of stars being born. Most of the visible light from the young stars in this region is obscured by the dense, dusty cloud in which they formed. With NASA's Spitzer Space Telescope, scientists can detect the infrared light from these objects. This allows a look through the dust to gain a more detailed understanding of how stars like our sun begin their lives.

The young stars in NGC 1333 do not form a single cluster, but are split between two sub-groups. One group is to the north near the nebula shown as red in the image. The other group is south, where the features shown in yellow and green abound in the densest part of the natal gas cloud. With the sharp infrared eyes of Spitzer, scientists can detect and characterize the warm and dusty disks of material that surround forming stars. By looking for differences in the disk properties between the two subgroups, they hope to find hints of the star and planet formation history of this region.

The knotty yellow-green features located in the lower portion of the image are glowing shock fronts where jets of material, spewed from extremely young embryonic stars, are plowing into the cold, dense gas nearby. The sheer number of separate jets that appear in this region is unprecedented. This leads scientists to believe that by stirring up the cold gas, the jets may contribute to the eventual dispersal of the gas cloud, preventing more stars from forming in NGC 1333.

In contrast, the upper portion of the image is dominated by the infrared light from warm dust, shown as red.

2005-01-01

392

Spectroscopic Binary Stars  

NASA Astrophysics Data System (ADS)

Historically, spectroscopic binary stars were binary systems whose nature was discovered by the changing DOPPLER EFFECT or shift of the spectral lines of one or both of the component stars. The observed Doppler shift is a combination of that produced by the constant RADIAL VELOCITY (i.e. line-of-sight velocity) of the center of mass of the whole system, and the variable shift resulting from the o...

Batten, A.; Murdin, P.

2000-11-01

393

The FTO gene polymorphism (rs9939609) is associated with metabolic syndrome in morbidly obese subjects from southern Italy.  

PubMed

Gene variants in MC4R, SIRT1 and FTO are associated with severe obesity and metabolic impairment in Caucasians. We investigated whether common variants in these genes are associated with metabolic syndrome (MetS) in a large group of morbidly obese young adults from southern Italy. One thousand morbidly obese subjects (62% women, mean body mass index 46.5 kg/m(2), mean age 32.6 years) whose families had lived in southern Italy for at least 2 generations were recruited. Single-nucleotide polymorphisms (SNPs) rs12970134, rs477181, rs502933 (MC4R locus), rs3818292, rs7069102, rs730821, rs2273773, rs12413112 (SIRT1 locus) and rs1421085, rs9939609, 9930506, 1121980 (FTO locus) were genotyped by Taqman assay; blood parameters were assayed by routine methods; the Fat Mass, Fat Free Mass, Respiratory Quotient, Basal Metabolic Rate (BMR) and waist circumference were also determined. Binomial logistic regression showed that the TA heterozygous genotype of SNP rs9939609 in the FTO gene was associated with the presence of MetS in our population [OR (95% CI): 2.53 (1.16-5.55)]. Furthermore, the FTO rs9939609 genotype accounted for 21.3% of the MetS phenotype together with total cholesterol, BMR and age. Our results extend the knowledge on genotype susceptibility for MetS in relation to a specific geographical area of residence. PMID:24675148

Liguori, Rosario; Labruna, Giuseppe; Alfieri, Andreina; Martone, Domenico; Farinaro, Eduardo; Contaldo, Franco; Sacchetti, Lucia; Pasanisi, Fabrizio; Buono, Pasqualina

2014-08-01

394

The Neutron Star Census  

NASA Astrophysics Data System (ADS)

The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a statistical sample of stars for different values of the initial kick velocity, drawn from an isotropic Gaussian distribution with mean velocity 0<=<=550 km s-1. The spin-down, induced by dipole losses and by the interaction with the ambient medium, is tracked together with the dynamical evolution in the Galactic potential, allowing for the determination of the fraction of stars which are, at present, in each of the four possible stages: ejector, propeller, accretor, and georotator. Taking from the ROSAT All Sky Survey an upper limit of ~10 accreting neutron stars within ~140 pc from the Sun, we infer a lower bound for the mean kick velocity, >~200-300 km s-1, corresponding to a velocity dispersion ?V>~125-190 km s-1. The same conclusion is reached for both a constant magnetic field (B~1012 G) and a magnetic field decaying exponentially with a timescale ~109 yr. Such high velocities are consistent with those derived from radio pulsar observations. Present results, moreover, constrain the fraction of low-velocity stars, which could have escaped pulsar statistics, to less than 1%.

Popov, S. B.; Colpi, M.; Treves, A.; Turolla, R.; Lipunov, V. M.; Prokhorov, M. E.

2000-02-01

395

MMT Hypervelocity Star Survey  

NASA Astrophysics Data System (ADS)

We describe a new survey for unbound hypervelocity stars (HVSs), stars traveling with such extreme velocities that dynamical ejection from a massive black hole is their most likely origin. We investigate the possible contribution of unbound runaway stars, and show that the physical properties of binaries constrain low-mass runaways to bound velocities. We measure radial velocities for HVS candidates with the colors of early A-type and late B-type stars. We report the discovery of six unbound HVSs with velocities and distances exceeding the conservative escape velocity estimate of Kenyon and collaborators. We additionally report four possibly unbound HVSs with velocities and distances exceeding the lower escape velocity estimate of Xue and collaborators. These discoveries increase the number of unbound HVSs by 60%-100%. Other survey objects include 19 newly identified z ~ 2.4 quasars. One of the HVSs may be a horizontal branch star, consistent with the number of evolved HVSs predicted by Galactic center ejection models. Finding more evolved HVSs will one day allow a probe of the low-mass regime of HVSs and will constrain the mass function of stars in the Galactic center.

Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.

2009-01-01

396

Meta-Analysis of the Association of the Rs2234693 and Rs9340799 Polymorphisms of Estrogen Receptor Alpha Gene with Coronary Heart Disease Risk in Chinese Han Population  

PubMed Central

Objective: The association between a common variant of the ESR1 gene rs2234693 and rs9340799 polymorphisms with coronary heart disease (CHD) have been reported, but the available data on this relationship are inconsistent. A meta-analysis was performed to quantitative analysis the association of ESR1 gene polymorphisms and CHD risk using previous case-control studies in Chinese Han population. Methods: Several electronic databases were searched for relevant articles up to August 2012. After data collection, a meta-analysis was performed to assess heterogeneity, combine results and evaluate variations. Different effect models were used according to the difference in heterogeneity. Sensitivity analysis was assessed by omitting one study at a time. Publication bias was examined using Begg's funnel plot and Egger's linear regression test. Results: Ten studies covering 3400 subjects on rs2234693 and rs9340799 polymorphisms in the ESR1 gene with CHD risk was included in this meta-analysis. For rs2234693 polymorphism, ten studies were combined to the meta-analysis. A significantly increased CHD risk was found in a dominant model (OR=1.35, 955 CI=1.01-1.81, P=0.05), recessive model (OR=1.40, 95% CI=1.15-1.69, P=0.0007), and additive model (OR=1.67, 95% CI=1.19-2.34, P=0.003). Subgroup for male but not for female showed that the CC genotype could increase the risk of CHD compared with TT and TC genotype in Chinese Han population. Concerning rs9340799 polymorphism, eight studies were combined to the meta-analysis. And no evidence of significant association with CHD risk was found in all genetic models. Conclusion: Our meta-analysis of 10 studies involving Chinese Han population suggests that the CC genotype of the ESR1 rs2234693 polymorphism is significantly associated with an increased risk of CHD in males only. There was no evidence however, of a significant association between the ESR1 rs9340799 polymorphism and CHD risk.

Wei, Chuan-Dong; Zheng, Hong-Yun; Wu, Wei; Dai, Wen; Tong, Yong-Qing; Wang, Ming; Li, Yan

2013-01-01

397

TP53 polymorphisms in gliomas from Indian patients: Study of codon 72 genotype, rs1642785, rs1800370 and 16 base pair insertion in intron-3.  

PubMed

Several single nucleotide polymorphisms of the TP53 gene have been reported, amongst which polymorphism in codon 72 (rs1042522) has received significant attention and shown to be associated with disease susceptibility in different cancer types. However, there are variable reports on this polymorphism in gliomas from worldwide with inconsistent results. In addition, the implications of other polymorphic loci are not much explored in gliomas. Hence, in the present study the TP53 sequence was analyzed for all polymorphism and mutations in a total of 84 gliomas of different types and grades from patients of Indian origin. The complete sequence of all coding exons (2 to 11) and introns 2, 3, 5 and 8 of TP53 gene were studied while for introns 1, 4, 6, 7, 9 and 10, only exon flanking regions could be studied. The polymorphic loci were compared with control population. In addition to the well known codon 72 polymorphism (rs1042522), three other polymorphisms rs1642785, rs1800370 and a 16 base pair insertion in intron-3 were found. At codon 72, our study showed higher Arg/Arg genotype in gliomas compared to normal population (38% versus 13%). The Arg allele frequency in glioma patients was comparatively higher than controls (0.55 versus 0.45; P=0.037). The Arg allele frequency was also high in adult glioblastomas compared to paediatric counterparts (0.55 versus 0.36). However, there was no significant association of TP53 mutations with any genotype of codon 72. At rs1642785, the G allele frequency was significantly higher in gliomas than in control population (0.55 versus 0.36, P=0.005). The genotype at a 16 base pair insertion in intron-3 was almost similar in case and control. However, the polymorphism at rs1800370 was exclusive to gliomas. This is the first report of TP53 gene polymorphism in glioma patients from India. Our study also delineates the frequency of four polymorphisms in gliomas for the first time. The codon 72 variant (rs1042522) and rs1642785 polymorphisms possibly poses risk to glioma development in Indian population. However, the functional significance of these polymorphism needs further elucidation. PMID:21115003

Jha, Prerana; Jha, Pankaj; Pathak, Pankaj; Chosdol, Kunzang; Suri, Vaishali; Sharma, Mehar Chand; Kumar, Guresh; Singh, Manmohan; Mahapatra, Ashok Kumar; Sarkar, Chitra

2011-04-01

398

Star formation around isolated T Tauri stars?  

NASA Astrophysics Data System (ADS)

The authors want to present their search for young stellar objects around the two isolated T Tau stars TW Hya (Rucinski and Krautter 1983) and CoD -29°8887 (de la Reza et al. 1989). From the known spectroscopic features of these objects, TW Hya is to be classified as a classical T Tau star (CTTS), but it is not associated with a dark cloud region like all other known CTTSs. The same situation turns out for the weak-line T Tau star (WTTS) CoD -29°8887. One possible explanation for their isolated position is that they have formed from small dark clouds or globules, which were later destroyed. The authors carried out two ROSAT PSPC observations pointing at TW Hya and CoD -29°8887 and used a source detection procedure considering all the standard ROSAT energy bands to test this hypothesis. Spectroscopic follow-up observations were made for 24 possible T Tauri candidates, but there are no further low-mass young stellar objects in the vicinity of the two targets. The study shows that the objects are definitely not formed in a cluster at the positions of the objects.

Hoff, W.; Pfau, W.; Henning, T.

1996-02-01

399

High spectral resolution observations of the coronal X-ray emission from the RS CVn binary Sigma Corona Borealis  

NASA Technical Reports Server (NTRS)

The results of high-resolution observations of the RS CVn binary star Rho Cr B are reported. The observations were carried out using the Focal Plane Crystal Spectrometer (FPCS) onboard the Einstein Observatory satellite. A spectral scan in the interval 800-840 eV shows clear evidence of an X-ray emission line at 826 eV identified with 1S(0)-1P(1) transition of Fe XVII. A prominent peak at 1007 eV in the scan band 986-1014 eV was attributed to a blend of lines produced by highly ionized iron. On the basis of the observed fluxes of the lines and the theoretical calculations of Raymond and Smith (1977), best-fit values of corona temperature and volume emission measures of 6.92 (+0.84 or -0.75) x 10 to the 6th K, and 1.74 (+0.55 or -0.69) x 10 to the 35th are derived, respectively. Some implications of the results are briefly discussed.

Agrawal, P. C.; Markert, T. H.; Riegler, G. R.

1985-01-01

400

Time-series photometric spot modeling. 2: Fifteen years of photometry of the bright RS CVn binary HR 7275  

NASA Technical Reports Server (NTRS)

We present a time-dependent spot modeling analysis of 15 consecutive years of V-band photometry of the long-period (P(sub orb) = 28.6 days) RS CVn binary HR 7275. This baseline in time is one of the longest, uninterrupted intervals a spotted star has been observed. The spot modeling analysis yields a total of 20 different spots throughout the time span of our observations. The distribution of the observed spot migration rates is consistent with solar-type differential rotation and suggests a lower limit of the differential-rotation coefficient of 0.022 +/-0.004. The observed, maximum lifetime of a single spot (or spot group) is 4.5 years, the minimum lifetime is approximately one year, but an average spot lives for 2.2 years. If we assume that the mechanical shear by differential rotation sets the upper limit to the spot lifetime, the observed maximum lifetime in turn sets an upper limit to the differential-rotation coefficient, namely 0.04 +/- 0.01. This would be differential rotation just 5 to 8 times less than the solar value and one of the strongest among active binaries. We found no conclusive evidence for the existence of a periodic phenomenon that could be attributed to a stellar magnetic cycle.

Strassmeier, K. G.; Hall, D. S.; Henry, G. W.

1994-01-01

401

A Study of the Coronal Plasma in RS CVn Binary Systems  

NASA Astrophysics Data System (ADS)

XMM-Newton has been performing comprehensive studies of X-ray bright RS CVn binaries in its Calibration and Guaranteed Time programs. We present results from ongoing investigations in the context of a systematic study of coronal emission from RS CVns. We concentrate in this paper on coronal abundances and investigate the abundance pattern in RS CVn binaries as a function of activity and average temperature. A transition from an Inverse First Ionization Potential (FIP) effect towards an absence of a clear trend is found in intermediately active RS CVn systems. This scheme corresponds well into the long-term evolution from an IFIP to a FIP effect found in solar analogs. We further study variations in the elemental abundances during a large flare.

Audard, M.; Güdel, A.; Sres, A.; Mewe, R.; Raassen, A. J. J.; Behar, E.; Foley, C. R.; van der Meer, R. L. J.

2003-10-01

402

The role of organizational culture in compliance with the principles of the 3Rs.  

PubMed

In order for their research to be legitimate, scientists carrying out research using animals must comply with rules and regulations. The 3Rs (replacement, reduction and refinement) are one set of guidelines that help to promote the ethical use of animals for research. An important question is whether implementing the principles of the 3Rs in legal regulations, such as a Directive of the European Parliament and of the Council on the protection of animals used for scientific purposes, will increase compliance with the principles of the 3Rs in research organizations. Previous work suggests that organizational culture is just as important for directing behavior as are formalized rules and regulations. This article introduces the concepts of compliance and organizational culture and discusses their consequences on the implementation of the principles of the 3Rs. PMID:21173772

Brønstad, Aurora; Berg, Anne-Grethe Trønsdal

2011-01-01

403

PVM system: Supercomputer level concurrent computation on a network of IBM RS/6000 power stations.  

National Technical Information Service (NTIS)

The PVM (Parallel Virtual Machine) system enables supercomputer level concurrent computations to be performed on interconnected networks of heterogeneous computer systems. Specifically, a network of 13 IBM RS/6000 powerstations has been successfully used ...

V. S. Sunderam G. A. Geist

1991-01-01

404

RS cyclophilins: identification of an NK-TR1-related cyclophilin.  

PubMed

We report the isolation of a large cyclophilin protein containing RS (arginine-serine) repeats from a yeast two-hybrid screen using ClK (CDC28/cdc2-like kinase) as a probe. This Clk associating RS-cyclophilin (CARS-Cyp) possesses 39% homology to the NK-TR1 (natural killer tumor recognition protein-1) we have previously characterized (Anderson et al. (1993) Proc. Natl. Acad. Sci. USA 90 (1993) 542-546). CARS-Cyp is expressed in a variety of tissues and cell types, and codes for a protein with a predicted mass of 89 kDa containing a cyclophilin-related domain, two Nopp140 (nucleolar phosphoprotein of 140 kDa)-related domains, and a large RS domain. The RS-cyclophilins, a novel class of proteins, may play an important role in the regulation of pre-mRNA splicing. PMID:8973360

Nestel, F P; Colwill, K; Harper, S; Pawson, T; Anderson, S K

1996-11-21

405

Common rs7138803 variant of FAIM2 and obesity in Han Chinese  

PubMed Central

Background Obesity causes severe healthcare problem worldwide leading to numerous diseases, such as cardiovascular diseases and diabetes mellitus. Previous Genome-Wide Association Study (GWAS) identified an association between a single nucleotide polymorphism (SNP) rs7138803, on chromosome 12q13 and obesity in European Caucasians. Since the genetic architecture governing the obesity may vary among different populations, we investigate the variant rs7138803 in Chinese population to find out whether it is associated with obesity. Methods A population-based cohort association study was carried out using the High Resolution Melt (HRM) method with 1851 participants. The association between rs7138803 genotypes and body mass index (BMI) was modeled with a general linear model, and a case–control study for the association between rs7138803 genotypes and obesity was performed using Pearson’s ?2 test. There was no indication of a deviation from Hardy-Weinberg equilibrium (HWE p value?=?0.51) in our sample. Results No association was detected between SNP rs7138803 and BMI in our Chinese Han population with a P value of 0.51. SNP rs7138803 was found to be not associated with common forms of obesity after adjusting for age and sex in the Chinese population. SNP rs7138803 was not associated with other obesity related traits, including T2DM, hypertension, lipid profiles, and ischemic stroke. Conclusion Our data suggest that the rs7138803 exerts no significant effect on obesity in Chinese Han population. Larger cohorts may be more appropriate to detect an effect of this SNP on common obesity.

2013-01-01

406

Performance analysis of RS-coded Mary FSK for frequency-hopping spread spectrum mobile radios  

Microsoft Academic Search

Decoding performance of Reed-Solomon (RS) coded M-ary FSK with noncoherent detection in a frequency-hopping spread spectrum mobile radio channel is theoretically analyzed. Exact formulas and an approximate one for evaluating word error rates (WERs) of error correction and error-and-erasure correction schemes on decoding the RS codes are derived. It is shown that with K symbol erasure and C symbol error

Tadashi Matsumoto; Akihiro Higashi

1992-01-01

407

Wireless transmission of RS232 interface signal based on ZigBee  

Microsoft Academic Search

RS232 interfaces are widely used in data transmission, such as wireless meter reading, digital image transmission, industrial data collection, cell paging, fire-proof system, radio frequency identification card, local alarm system, and so on. Since the longest distance of cable transmission is only 15 meters, so it is important to develop a kind of RS232 interface used for wireless transmission. ZigBee

Guoxin Luo

2010-01-01

408

The GraRS regulatory system controls Staphylococcus aureus susceptibility to antimicrobial host defenses  

Microsoft Academic Search

BACKGROUND: Modification of teichoic acids with D-alanine by the products of the dlt operon protects Gram-positive bacteria against major antimicrobial host defense molecules such as defensins, cathelicidins, myeloperoxidase or phospholipase. The graRS regulatory genes have recently been implicated in the control of D-alanylation in Staphylococcus aureus. RESULTS: To determine the impact of the GraRS regulatory system on resistance to antimicrobial

Dirk Kraus; Silvia Herbert; Sascha A Kristian; Arya Khosravi; Victor Nizet; Friedrich Götz; Andreas Peschel

2008-01-01

409

On the performance of bandwidth efficient RS coded MPSK signaling over a Rayleigh fading channel  

Microsoft Academic Search

The idea of combining RS (Reed-Solomon) codes with multiphase signaling schemes on fading channels is introduced. The performance of these schemes over a Rayleigh fading channel is evaluated. The lower bound of the post decoding bit error probability for three RS-coded 8-PSK (phase-shift keying) schemes for both errors-only decoding and erasures-and-errors decoding techniques are obtained through the analysis and computer

S. Hamidreza Jamali; Tho Le-Ngoc

1991-01-01

410

A simplified algorithm for correcting both errors and erasures of R-S codes  

NASA Technical Reports Server (NTRS)

Using the finite field transform and continued fractions, a simplified algorithm for decoding Reed-Solomon (R-S) codes is developed to correct erasures caused by other codes as well as errors over the finite field GF (q(m), where q is a prime and m is an integer. Such an R-S decoder can be faster and simpler than a decoder that uses more conventional methods.

Reed, I. S.; Truong, T. K.

1978-01-01

411

Masses and ages of Delta Scuti stars in eclipsing binary systems  

NASA Astrophysics Data System (ADS)

By using data mainly from Frolov et al. (1982) for four Delta Scuti stars in eclipsing binary systems, AB Cas, Y Cam, RS Cha, and AI Hya, their physical parameters, distances, and radial pulsation modes are determined. The evolutionary track systems of Iben (1967), Paczynski (1970), and Maeder and Meynet (1988) are interpolated in order to estimate evolutionary masses Me and ages t of these variables. Their pulsation masses MQ are estimated from the fitting formulae of Faulkner (1977) and Fitch (1981). Our estimates of evolutionary masses M(e) and pulsation masses M(Q) are close to the masses M determined by Frolov et al. from the star binarity. The only exception is AB Cas, for which there is no agreement between certain star parameters. Another, independent approach is also applied to the stars RS Cha and AI Hya: by using their photometric indices b - y and c(1) from the catalog of Lopez de Coca et al. (1990) and appropriate photometric calibrations, other sets of physical parameters, distances, modes, ages, and evolutionary and pulsation masses of both variables are obtained.

Tsvetkov, Ts. G.; Petrova, Ts. C.

1993-05-01

412

Life Cycle of Stars  

NASA Technical Reports Server (NTRS)

In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper left of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2.

1999-01-01

413

BV(RI)C photometry of 4 S-type AGB (Adelman+, 2005)  

NASA Astrophysics Data System (ADS)

We present FCAPT differential Johnson BV and Cousins RI photometry and radial velocities of the S-type AGB stars RS Cnc, ST Her, OP Her and HR Peg. We performed multiperiodic analyses of this photometry to learn about the frequencies of variability. The B, V, R, and I light curves are generally in phase. RS Cnc has periods of order 122 and 248 days. Repeating the analyses using our data with the extensive V and R photometry of Percy et al. (2001PASP..113..983P) shows several periods near 248 days and a period near 135 days. The primary period of ST Her appears to be about 144 days although it is manifested most readily by its 103 day alias. OP Her and HR Peg exhibit periods, respectively, of about 416 and 116 days and of 54 and 74 days. The differences between our data set and the larger one of Percy et al. (2001PASP..113..983P) for RS Cnc raises important questions about multiperiodic analyses for AGB stars. (5 data files).

Adelman, S. J.; Dennis, J. W. Iii

2005-01-01

414

The Common Variant rs11646213 Is Associated with Preeclampsia in Han Chinese Women  

PubMed Central

Background Preeclampsia, characterized by hypertension and proteinuria, is a multifactorial disease caused by complex interactions between environmental and genetic factors. A recent genome-wide association study of blood pressure reported an association between hypertension and rs11646213. This study evaluated the association between preeclampsia and rs11646213. Methods A total of 454 cases and 460 controls were recruited to participate in this study. The single nucleotide polymorphism (SNP) rs11646213 was genotyped by polymerase chain reaction (PCR) and direct sequencing. Results The allele frequency of rs11646213 was significantly different between the preeclampsia and control groups (P?=?0.017, OR?=?1.36, 95% CI?=?1.06–1.76). Differences were particularly significant in the severe preeclampsia subgroup (P?=?0.002, OR?=?1.54, 95% CI?=?1.17–2.03) and the early-onset preeclampsia subgroup (P?=?0.004, OR?=?1.57, 95% CI?=?1.16–2.13). Genotyping analysis showed that the T allele of rs11646213 could confer a risk for preeclampsia, severe preeclampsia and early-onset preeclampsia. Conclusions Rs11646213 upstream of the CDH13 gene is associated with preeclampsia in Han Chinese women.

Wan, Ji-peng; Zhao, Han; Li, Tao; Li, Chang-zhong; Wang, Xie-tong; Chen, Zi-Jiang

2013-01-01

415

Association study of IFIH1 rs1990760 polymorphism with systemic lupus erythematosus in a Chinese population.  

PubMed

Systemic lupus erythematosus (SLE) is a complex autoimmune disease arising from the action of multiple genetic and environmental risk factors. The aim of this study was to examine the association of a single-nucleotide polymorphism, rs1990760, of the interferon induced with helicase C domain 1 (IFIH1) gene with SLE in a Chinese population. A total of 877 SLE patients and 978 healthy control subjects were enrolled in the present study. The genotype of the IFIH1 rs1990760 polymorphism was determined by Sequenom MassARRAY technology. The IFIH1 rs1990760 T allele was significantly increased in patient group compared with control subjects (T versus C, Odds ratio?=?1.20, 95 % confidence interval?=?1.02-1.40). However, no significant difference in genotype distribution was found between cases and controls (P?=?0.07). No significant evidence was detected for the association of the IFIH1 rs1990760 polymorphism with SLE under neither dominant nor recessive model (TT + TC versus CC, P?=?0.06; TT versus TC + CC, P?=?0.08). We also analyzed the association of the IFIH1 rs1990760 T allele with clinical features, whereas no significant signal was found. In conclusion, our study represents the first report demonstrating an association of the IFIH1 rs1990760 polymorphism with SLE susceptibility in a Chinese population. PMID:23108955

Cen, Han; Leng, Rui-Xue; Wang, Wei; Zhou, Mo; Feng, Chen-Chen; Zhu, Yan; Yang, Xiao-Ke; Yang, Mei; Zhai, Yu; Li, Bao-Zhu; Liu, Juan; Pan, Hai-Feng; Ye, Dong-Qing

2013-04-01

416

Association between the rs342293 polymorphism and adverse cardiac events in patients undergoing percutaneous coronary intervention.  

PubMed

The single nucleotide polymorphism (SNP) rs342293 has been shown to influence platelet number and mean platelet volume (MPV). We investigated the association between the rs342293 polymorphism and cardiovascular outcome in a prospective cohort study. The rs342293 polymorphism was analysed in 404 patients with coronary artery disease undergoing percutaneous coronary intervention. The rates of cardiac adverse events were recorded during two years of follow-up. The polymorphism was associated with MPV (median 10.1 fL, interquartile range [IQR]: 9.6 to 10.6 in patients with the CC-allele vs 10.4 fL, IQR: 9.9 to 11.1 in G>C SNP carriers; p<0.001), but not with platelet count. Survival analysis indicated that carriers of the rs342293 G variant had a substantially higher risk to develop cardiac adverse events compared with wild type carriers during two years of follow-up (33% vs 22%; adjusted hazard ratio = 1.63, 95% confidence interval = 1.06-2.52, p=0.027). The rs342293 SNP could explain 2.9% of the variability in MPV (p=0.01). In conclusion, patients undergoing coronary stenting who carry the G-variant of the rs342293 SNP which is associated with larger MPV are at higher risk for adverse cardiovascular outcome. PMID:24652536

Siller-Matula, J M; Arbesu, I; Jilma, B; Maurer, G; Lang, I M; Mannhalter, C

2014-06-01

417

Single nucleotide polymorphism rs1052501 associated with monoclonal gammopathy of undetermined significance and multiple myeloma  

PubMed Central

Summary Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant precursor to multiple myeloma (MM). Though several genetic variants have been identified for MM, none have been identified for MGUS. Recently, Broderick et al. conducted a GWAS of MM and identified three novel loci at 3p22.1 (rs1052501), 7p15.3 (rs4487645) and 2p23.3 (rs6746082) associated with MM risk. We examined the association of these variants with MGUS in a clinic-based case-control study of 391 MGUS cases and 365 controls. We also attempted to replicate the reported association with MM (243 MM cases, 365 controls). We found rs1052501 associated with increased risk of both MGUS (OR=1.32; 95% CI, 1.02 to 1.72; p=0.04) and MM (OR=1.39; 95% CI, 1.04, 1.86; p=0.03). However, there were no associations with the other two loci, rs6746082 and rs4487645, for either MGUS or MM. We identified one genetic variant that may exert its influence on MM through its association with MGUS.

Greenberg, Alexandra J.; Lee, Adam M.; Serie, Daniel J.; McDonnell, Shannon K.; Cerhan, James R.; Liebow, Mark; Larson, Dirk R.; Colby, Colin L.; Norman, Aaron D.; Kyle, Robert A.; Rajkumar, S. Vincent; Diasio, Robert B.; Slager, Susan L.; Vachon, Celine M.

2013-01-01

418

Icb-1 gene polymorphism rs1467465 is associated with susceptibility to ovarian cancer  

PubMed Central

In this study, we tested the hypothesis that single nucleotide polymorphisms (SNPs) of differentiation-associated human gene icb-1 (C1orf38) may be associated with ovarian cancer susceptibility. For this purpose, we compared the genotype and allele frequencies of the SNPs rs1467465 and rs12048235 in a group of 184 ovarian cancer patients with a control group of 184 age- and gender-matched women without any malignancy. Genotype-phenotype association revealed that A allele of SNP rs1467465 was more frequent in ovarian cancer patients than in the control group (0.40 vs. 0.33, OR 1.37, 95% CI 1.013-1.853, p?=?0.04). After analysis of allele positivity we observed that A-positive genotypes were more frequent in the ovarian cancer group (0.65 vs. 0.53, OR 1.63, 95% CI 1.072-2.483, p?=?0.02). Furthermore, the heterozygous genotype of rs1467465 was found to be more frequent in the patients group (0.50 vs. 0.41, OR 1.63, 95% CI 1.045-2.045, p?=?0.03). No significant results were obtained with regard to SNP rs1204823. Our data suggest, that SNP rs1467465 of human gene icb-1 might affect susceptibility to ovarian cancer.

2014-01-01

419

Growth Phase-Dependent Activation of the DccRS Regulon of Campylobacter jejuni?  

PubMed Central

Two-component systems are widespread prokaryotic signal transduction devices which allow the regulation of cellular functions in response to changing environmental conditions. The two-component system DccRS (Cj1223c-Cj1222c) of Campylobacter jejuni is important for the colonization of chickens. Here, we dissect the DccRS system in more detail and provide evidence that the sensor DccS selectively phosphorylates the cognate effector, DccR. Microarray expression profiling, real-time reverse transcription-PCR (RT-PCR), electrophoretic mobility shift assay, and primer extension analyses revealed that the DccRS regulon of strain 81116 consists of five promoter elements, all containing the consensus direct repeat sequence WTTCAC-N6-TTCACW covering the putative ?35 promoter regions. One of these promoters is located in front of an operon encoding a putative macrolide efflux pump while the others are in front of genes coding for putative periplasmic or membrane proteins. The DccRS-regulated genes in C. jejuni strain 81116 are needed to enhance early in vivo growth of C. jejuni in 7-day-old chickens. The DccRS system is activated in the late stationary bacterial growth phase, probably by released metabolic products. Whole-genome mRNA profiling and real-time RT-PCR analysis under these conditions demonstrated that the system has no influence on the transcription of genes outside the DccRS regulon.

Wosten, Marc M. S. M.; van Dijk, Linda; Parker, Craig T.; Guilhabert, Magalie R.; van der Meer-Janssen, Ynske P. M.; Wagenaar, Jaap A.; van Putten, Jos P. M.

2010-01-01

420

Blurred Star Image Processing for Star Sensors under Dynamic Conditions  

PubMed Central

The precision of star point location is significant to identify the star map and to acquire the aircraft attitude for star sensors. Under dynamic conditions, star images are not only corrupted by various noises, but also blurred due to the angular rate of the star sensor. According to different angular rates under dynamic conditions, a novel method is proposed in this article, which includes a denoising method based on adaptive wavelet threshold and a restoration method based on the large angular rate. The adaptive threshold is adopted for denoising the star image when the angular rate is in the dynamic range. Then, the mathematical model of motion blur is deduced so as to restore the blurred star map due to large angular rate. Simulation results validate the effectiveness of the proposed method, which is suitable for blurred star image processing and practical for attitude determination of satellites under dynamic conditions.

Zhang, Weina; Quan, Wei; Guo, Lei

2012-01-01

421

Blurred star image processing for star sensors under dynamic conditions.  

PubMed

The precision of star point location is significant to identify the star map and to acquire the aircraft attitude for star sensors. Under dynamic conditions, star images are not only corrupted by various noises, but also blurred due to the angular rate of the star sensor. According to different angular rates under dynamic conditions, a novel method is proposed in this article, which includes a denoising method based on adaptive wavelet threshold and a restoration method based on the large angular rate. The adaptive threshold is adopted for denoising the star image when the angular rate is in the dynamic range. Then, the mathematical model of motion blur is deduced so as to restore the blurred star map due to large angular rate. Simulation results validate the effectiveness of the proposed method, which is suitable for blurred star image processing and practical for attitude determination of satellites under dynamic conditions. PMID:22778666

Zhang, Weina; Quan, Wei; Guo, Lei

2012-01-01

422

RR Lyrae Stars in the GCVS Observed by the Qatar Exoplanet Survey  

NASA Astrophysics Data System (ADS)

We used the light curve archive of the Qatar Exoplanet Survey to investigate the RR Lyrae variable stars listed in the GCVS. Of 588 variables studied, we reclassified 14 as eclipsing binaries, one as an RS CVn type variable, one as an irregular variable, four as classical Cepheids, and one as a type II Cepheid, while also improving their periods. We also report new RR Lyrae sub-type classifications for 65 variables and improve on the GCVS period estimates for 135 RR Lyrae variables. There are seven double-mode RR Lyrae stars in the sample for which we measured their fundamental and first overtone periods. Finally, we detected the Blazhko effect in 38 of the RR Lyrae stars for the first time and we successfully measured the Blazhko period for 26 of them.

Bramich, D. M.; Alsubai, K. A.; Arellano Ferro, A.; Parley, N. R.; Collier Cameron, A.; Horne, K.; Pollacco, D.; West, R. G.

2014-05-01

423

Pre-main sequence stars, emission stars and recent star formation in the Cygnus region  

NASA Astrophysics Data System (ADS)

The recent star formation history in the Cygnus region is studied using 5 clusters (IC 4996, NGC 6910, Berkeley 87, Biurakan 2 and Berkeley 86). The optical data from the literature are combined with the 2MASS data to identify the pre-main sequence (pre-MS) stars as stars with near IR excess. We identified 93 pre-MS stars and 9 stars with H_alpha emission spectra. The identified pre-MS stars are used to estimate the turn-on age of the clusters. The duration of star formation was estimated as the difference between the turn-on and the turn-off age. We find that, NGC 6910 and IC 4996 have been forming stars continuously for the last 6 -- 7 Myr, Berkeley 86 and Biurakan 2 for 5 Myr and Berkeley 87 for the last 2 Myr. This indicates that the Cygnus region has been actively forming stars for the last 7 Myr, depending on the location. Nine emission line stars were identified in 4 clusters, using slit-less spectra (Be 87 - 4 stars; Be 86 - 2 stars, NGC 6910 - 2 stars and IC 4996 - 1 star). The individual spectra were obtained and analysed to estimate stellar as well as disk properties. All the emission stars are in the MS, well below the turn-off, in the core hydrogen burning phase. These stars are likely to be Classical Be (CBe) stars. Thus CBe phenomenon can be found in very young MS stars which are just a few (2--7) Myr old. This is an indication that CBe phenomenon need not be an evolutionary effect.

Bhavya, B.; Mathew, Blesson; Subramaniam, Annapurni

424

Chemical Evolution of Binary Stars  

NASA Astrophysics Data System (ADS)

Energy generation by nuclear fusion is the fundamental process that prevents stars from collapsing under their own gravity. Fusion in the core of a star converts hydrogen to heavier elements from helium to uranium. The signature of this nucleosynthesis is often visible in a single star only for a very short time, for example while the star is a red giant or, in massive stars, when it explodes. Contrarily, in a binary system nuclear-processed matter can captured by a secondary star which remains chemically polluted long after its more massive companion star has evolved and died. By probing old, low-mass stars we gain vital insight into the complex nucleosynthesis that occurred when our Galaxy was much younger than it is today. Stellar evolution itself is also affected by the presence of a companion star. Thermonuclear novae and type Ia supernovae result from mass transfer in binary stars, but big questions still surround the nature of their progenitors. Stars may even merge and one of the challenges for the future of stellar astrophysics is to quantitatively understand what happens in such extreme systems. Binary stars offer unique insights into stellar, galactic and extragalactic astrophysics through their plethora of exciting phenomena. Understanding the chemical evolution of binary stars is thus of high priority in modern astrophysics.

Izzard, R. G.

2013-02-01

425

Polydisperse star polymer solutions  

PubMed

We analyze the effect of polydispersity in the arm number on the effective interactions, structural correlations, and phase behavior of star polymers in a good solvent. The effective interaction potential between two star polymers with different arm numbers is derived using scaling theory. The resulting expression is tested against monomer-resolved molecular dynamics simulations. We find that the theoretical pair potential is in agreement with the simulation data in a much wider polydispersity range than other proposed potentials. We then use this pair potential as an input in a many-body theory to investigate polydispersity effects on the structural correlations and the phase diagram of dense star polymer solutions. In particular, we find that a polydispersity of 10%, which is typical in experimental samples, does not significantly alter previous findings for the phase diagram of monodisperse solutions. PMID:11102050

von Ferber C; Jusufi; Watzlawek; Likos; Lowen

2000-11-01

426

Energy Production in Stars  

NSDL National Science Digital Library

Energy Production in Stars is part of the Astronomy 162: Stars, Galaxies, and Cosmology course offered by the Department of Physics and Astronomy at the University of Tennessee. This section covers the mass-energy relation of special relativity; the curve of binding energy, and its implications for fusion and fission reactions, and stellar energy production; nuclear reactions, and their relation to the Coulomb barrier, and quantum mechanical tunneling; temperature and pressure in stars, including the kinetic theory of gases, ideal gas law, and the Gamow window for charged particle reactions; the proton-proton chain; the carbon-nitrogen-oxygen (CNO) cycle; the triple-alpha process, mass-5 and mass-8 bottlenecks; advanced burning stages; stellar energy transport; and the solar neutrino problem.

2007-04-13

427

GuideStar  

NSDL National Science Digital Library

Donors and philanthropists can now more easily compare and monitor organizations to which they may contribute, while nonprofit organizations can perhaps spend less of their resources on fundraising. These are the goals of Philanthropic Research, Inc's GuideStar, a clearinghouse of information on more than 600,000 charities and nonprofit organizations. GuideStar hosts a searchable database, a newsletter, employment and volunteer opportunity listings, and valuable articles in addition to lists of links for both donors and nonprofit organizations. Database information includes brief descriptions of the charities/nonprofits and their programs, funding sources, geographic location(s), and income/asset statements. GuideStar derives its information from 990 tax submissions to the IRS as well as directly from the nonprofit organizations themselves.

428

Subdwarf B Star Rotation  

NASA Astrophysics Data System (ADS)

A transfer of angular momentum from the core to envelope is understood to occur in red giants as evolution up the Red Giant Branch proceeds. As a consequence, any subdwarf-B star which had a red giant progenitor may be expected to be a slow rotator; KIC 010139564 could be an object of this kind as it is known to have a long rotation period of 25.6±1.8 days, determined from the rotation splitting of nonradial modes. As rotation splitting of nonradial modes will not be resolved in every case, it is proposed in the present paper that subdwarf-B star rotation periods might be determined from the pulsation amplitude variations of these modes, caused by beating between closely spaced but unresolved rotation splitting. Any successful determination of a substantial number of subdwarf-B star rotation rates could, when linked to progenitor red giant core rotation rates, provide a further constraint on binary population synthesis models.

Lynas-Gray, A.

2014-04-01

429

Association study of SNPs of genes IFNGR1 (rs137854905), GSTT1 (rs71748309), and GSTP1 (rs1695) in gastric cancer development in samples of patient in the northern and northeastern Brazil.  

PubMed

Cancer is a multifactorial disease with a high mortality rate in Brazil and worldwide. Gastric cancer (GC) is considered the fourth type of malignancy more frequent in the population worldwide and the second leading cause of death. This work aimed to evaluate single nucleotide polymorphisms (SNPs) of IFNGR1, GSTT1, and GSTP1 genes samples in gastric cancer. We analyzed 60 samples of gastric cancer, 26 diffuse and 34 intestinal types, totaling 120 alleles for each SNP. The results were obtained by PCR and allele-specific PCR. Statistical analyzes performed using BioEstat 5.0 software, applying the Fisher's exact test and chi-square. Only the SNP gene GSTP1 (rs1695) were significantly associated with gastric cancer in the samples analyzed (? (2)?=?8.73, P?rs1695) can be considered a risk factor associated with gastric carcinogenesis. PMID:24453034

de Araújo, Rubistenia Miranda Soares; de Melo, Cynthia Farias Vieira; Neto, Fidelis Manes; da Silva, Juarez Nóbrega; Soares, Leonardo Ferreira; de Arruda Cardoso Smith, Marilia; Sousa, Edilson Carvalho; Burbano, Rommel Mario Rodríguez; de Medeiros, Arnaldo Correia; Lima, Eleonidas Moura

2014-05-01

430

Probing the interplay between electrostatic and dispersion interactions in the solvation of nonpolar nonaromatic solute molecules in ionic liquids: An OKE spectroscopic study of CS2/[CnC1im][NTf2] mixtures (n = 1-4)  

NASA Astrophysics Data System (ADS)

The intermolecular dynamics of dilute solutions of CS2 in 1-alkyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]amide ([CnC1im][NTf2] for n = 1-4) were studied at 295 K using femtosecond optical Kerr effect (OKE) spectroscopy. The OKE spectra of the CS2/ionic liquid (IL) mixtures were analyzed using an additivity model to obtain the CS2 contribution to the OKE spectrum from which information about the intermolecular modes of CS2 in these mixtures was gleaned. The intermolecular spectrum of CS2 in these mixtures is lower in frequency and narrower than that of neat CS2, as found previously for CS2 in [C5C1im][NTf2]. Moreover, a dependence of the spectra on alkyl chain length is observed that is attributed to the interplay between electrostatic and dispersion interactions. The surprising result in this study is the solubility of CS2 in [C1C1im][NTf2], which involves the interaction of a nonpolar nonaromatic molecular solute and only the charged groups of the IL. We propose that the solubility of CS2 in [C1C1im][NTf2] is determined by three favorable factors - (1) large polarizability of the solute molecule; (2) small size of the solute molecule; and (3) low cohesive energy in the high-charge density regions of the IL.

Xue, Lianjie; Tamas, George; Gurung, Eshan; Quitevis, Edward L.

2014-04-01

431

Preparation of Gd2O2S:Yb,Ho Phosphor via Thermolysis of Sulfur-Contained (Gd,Yb,Ho)[S2CN(C4H8)]3 Phen Complexes  

NASA Astrophysics Data System (ADS)

A novel handy single-source precursor method is adopted to prepare Gd2O2S:Yb,Ho up-conversion phosphors. Pure Gd2O2S:Yb0.06Ho0.02 phosphors are prepared via thermolysis of the air-stable ternary solid complexes RE[S2CN(C4H8)]3phen (RE=Gd, Yb, Ho) in a nitrogen atmosphere with certain amount of oxygen at 600-1100°C. The as-prepared Gd2O2S:Yb0.06Ho0.02 exhibits a strong green up-conversion luminescence under 980 nm IR excitation. The intensity of the green emission component is 37.4 and 53.4 times more than that of the red and NIR emissions, respectively. It is indicated that the material is of excellent color purity. Under an IR excitation density of 34.75 mW/mm2 with a laser beam diameter of 1 mm, the material exhibits an up-conversion luminescence brightness of 43.68 Cd/m2.

Zhong, Hai-Yang; Luo, Xi-Xian; Ma, Lu-Bin; Zhang, Ming; Xing, Ming-Ming; Fu, Yao

2011-04-01

432

Probing the interplay between electrostatic and dispersion interactions in the solvation of nonpolar nonaromatic solute molecules in ionic liquids: An OKE spectroscopic study of CS2/[CnC1im][NTf2] mixtures (n = 1-4).  

PubMed

The intermolecular dynamics of dilute solutions of CS2 in 1-alkyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]amide ([CnC1im][NTf2] for n = 1-4) were studied at 295 K using femtosecond optical Kerr effect (OKE) spectroscopy. The OKE spectra of the CS2/ionic liquid (IL) mixtures were analyzed using an additivity model to obtain the CS2 contribution to the OKE spectrum from which information about the intermolecular modes of CS2 in these mixtures was gleaned. The intermolecular spectrum of CS2 in these mixtures is lower in frequency and narrower than that of neat CS2, as found previously for CS2 in [C5C1im][NTf2]. Moreover, a dependence of the spectra on alkyl chain length is observed that is attributed to the interplay between electrostatic and dispersion interactions. The surprising result in this study is the solubility of CS2 in [C1C1im][NTf2], which involves the interaction of a nonpolar nonaromatic molecular solute and only the charged groups of the IL. We propose that the solubility of CS2 in [C1C1im][NTf2] is determined by three favorable factors - (1) large polarizability of the solute molecule; (2) small size of the solute molecule; and (3) low cohesive energy in the high-charge density regions of the IL. PMID:24784292

Xue, Lianjie; Tamas, George; Gurung, Eshan; Quitevis, Edward L

2014-04-28

433

Computational astrophysics: Pulsating stars  

SciTech Connect

The field of computational astrophysics in pulsating star studies has grown considerably since the advent of the computer. Initially calculatio