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Sample records for star rs cnc

  1. The Multi-Scale Environment of RS Cnc from CO and HI Observations

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    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' (˜0.24 pc). The close environment of RS Cnc (from 1 to 20″) can be described with a model in which the density and velocity vary smoothly from the equatorial plane to the polar axis. In this model the mass loss rate is higher along the polar directions than in the equatorial plane, which does not favor current models invoking stellar rotation or a magnetic field as the cause of the axi-symmetry. Outside this region, the study of which is limited by the photo-dissociation of CO, HI data at 21 cm show that the flow is slowed down at a typical distance of 1' (˜0.04 pc). Further away (1 to 6', or 0.04 to 0.24 pc), the flow is distorted by the relative motion of the star with respect to the interstellar medium.

  2. On the Central Symmetry of the Circumstellar Envelope of RS Cnc

    NASA Astrophysics Data System (ADS)

    Nhung, P. T.; Hoai, D. T.; Winters, J. M.; Darriulat, P.; Gérard, E.; Le Bertre, T.

    2015-08-01

    We present a phenomenological study of CO (1-0) and CO (2-1) emission from the circumstellar envelope (CSE) of the AGB star RS Cnc. It reveals departures from central symmetry that turn out to provide a new tool for the exploration of some of the CSE properties. We use a wind model including a bipolar flow with a typical wind velocity of ˜8 km s-1, decreasing to ˜2 km s-1 near the equator, to describe Doppler velocity spectral maps obtained by merging data collected at the IRAM Plateau de Bure Interferometer and the Pico Veleta single-dish radio telescope. Parameters describing the wind morphology and kinematics are obtained, together with the radial dependence of the gas temperature in the domain of the CSE probed by the CO observations. Significant north-south central asymmetries are revealed by the analysis, which we quantify using a simple phenomenological description. The origin of such asymmetries is unclear for the moment.

  3. On the central symmetry of the circumstellar envelope of RS Cnc

    NASA Astrophysics Data System (ADS)

    Tuyet Nhung, Pham; Thi Hoai, Do; Winters, Jan Martin; Darriulat, Pierre; Gérard, Eric; Le Bertre, Thibaut

    2015-05-01

    We present a phenomenological study of CO(1-0) and CO(2-1) emission from the circumstellar envelope (CSE) of the Asymptotic Giant Branch (AGB) star RS Cnc. It reveals departures from central symmetry that turn out to be efficient tools for the exploration of some of the properties of the CSE. We use a wind model including a bipolar flow with a typical wind velocity of ~8 km s-1 that decreases to ~2 km s-1 near the equator. This wind model is used to describe Doppler velocity spectral maps obtained by merging data collected at the IRAM Plateau de Bure Interferometer and Pico Veleta single dish radio telescope. Parameters describing the wind morphology and kinematics are obtained, together with the radial dependence of the gas temperature in the domain of the CSE probed by the CO observations. Significant north-south central asymmetries are revealed by the analysis, which we quantify using a simple phenomenological description. The origin of such asymmetries is unclear. 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).

  4. RS CVn stars - Chromospheric phenomena

    NASA Technical Reports Server (NTRS)

    Bopp, B. W.

    1983-01-01

    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.

  5. Infrared observations of RS CVn stars

    NASA Technical Reports Server (NTRS)

    Berriman, G.; De Campli, W. M.; Werner, M. W.; Hatchett, S. P.

    1983-01-01

    The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.

  6. Line blanketed model atmospheres of Ap-stars. V - The Hg-Mn stars 53 Tau and Kappa CNC

    NASA Astrophysics Data System (ADS)

    Stepien, K.; Muthsam, H.

    1981-07-01

    All available observations of the energy distributions of 53 Tau and κ Cnc from the wavelength interval between Lα and the Paschen jump are compared with a series of model atmospheres in which temperature, microturbulent velocity and chemical composition were varied. Good agreement is obtained if effective temperatures of 53 Tau and κ Cnc are 11,250 K and 12,800 K, respectively, and the chemical compositions are taken from Strom (1969) and Kodaira (1965). New chemical compositions obtained by Heacox (1979) produce too much blanketing in UV, particularly for κ Cnc. For 53 Tau the set with υmicr = 0 gives equally good fit as the old abundances and the resulting temperature is 11,400 K. Observations of both stars show a slight excess of radiation in the red. It is suggested that this excess may be caused by the circumstellar matter.

  7. Legislation may support STaRS

    NASA Astrophysics Data System (ADS)

    Congressman Vernon Ehlers (R, MI) has offered three bills in the House of Representatives that support K-12 science, math, engineering, and technology (SMET) education (Eos, April 18, 2000). Although no dollar amounts are mentioned, the three bills contain numerous provisions for improving and expanding SMET education activities at the Department of Education and the National Science Foundation, and for tax incentives for pre-service teacher education and in-service professional development. Of particular interest is Section 15 of H.R. 4271, the National Science Education Act, which directs the NSF to provide scholarships for K-12 teachers to participate in research programs in government agencies, colleges and universities, or private research establishments. Such scholarships could support AGU's Science Teacher and Research Scientist (STaRS) effort, which is intended to provide opportunities for teachers to participate in research under the direction of AGU scientists, and for those same scientists to participate in science teaching under the teachers' direction.

  8. Theoretical studies of the RS Canum Venaticorum stars

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1982-01-01

    The activity in RS Canum Venaticorum (CVn) is investigated. Models for chromospheric structure are developed and the role of magnetic fields both in the photosphere as well as in the chromosphere and upper atmosphere are examined. T Tau stars are also studied from the same points of view. The properties of magnetic field loops are used to help understand the atmospheric structure in RS CVn stars. The concepts developed in the case of these stars appear to be applicable over a much broader region of the HR diagram. The absence of stable magnetic loops in the atmospheres of late type giant stars suggests that the atmospheres of RS CVn active components are qualitatively distinct from the solar atmosphere.

  9. H i and CO in the circumstellar environment of the S-type star RS Cancri

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    Context. The history of mass loss during the AGB phase is key to understanding the stellar evolution and the gas and dust replenishment of the interstellar medium. The mass-loss phenomenon presents fluctuations with a wide variety of timescales and spatial scales and requires combining data from multiple tracers. Aims: We study the respective contributions of the central source and of the external medium to the complex geometry of circumstellar ejecta. Methods: This paper presents Plateau de Bure Interferometer and IRAM 30-m telescope CO rotational line observations, along with H i data obtained with the Nançay Radio Telescope for the oxygen-rich semi-regular variable RS Cnc, in order to probe its circumstellar environment on different scales. Results: We detect both the CO(1-0) and the CO(2-1) rotational lines from RS Cnc. The line profiles are composite, comprising two components of half-width ~2 km s-1 and ~8 km s-1, respectively. Whereas the narrow velocity component seems to originate in an equatorial disk in the central part of the CO envelope, the broad component reveals a bipolar structure, with a north-south velocity gradient. In addition, we obtain new H i data on the source and around it in a field of almost 1 square degree. The H i line is centered on vLSR = 7 km s-1 in agreement with CO observations. A new reduction process reveals a complex extended structure in the northwest direction, of estimated size ~18', with a position angle (~310°) opposite the direction of the stellar proper motion (~140°). We derive an H i mass of ~3 × 10-2 M_⊙ for this structure. Based on a non spherical simulation, we find that this structure is consistent with arising from the interaction of the star undergoing mass loss at an average rate of ~10-7 M⊙ yr-1 over ~2-3 × 105 years with the interstellar medium. Conclusions: Using CO and H i lines, we show that the circumstellar environment around RS Cnc includes two related but well separated regions. With CO, we

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

    SciTech Connect

    Gould, A.; Yee, J. C.; Pinsonneault, M. H.; Dong, Subo; Gaudi, B. S.; Hung, L.-W.; Bond, I. A.; Udalski, A.; Han, C.; Jorgensen, U. G.; Greenhill, J.; Tsapras, Y.; Bensby, T.; Allen, W.; Almeida, L. A.; Jablonski, F.; Bos, M.; Christie, G. W.; DePoy, D. L.; Lee, C.-U.; Collaboration: muFUN Collaboration; MOA Collaboration; OGLE Collaboration; MiNDSTEp Consortium; RoboNet Collaboration; PLANET Collaboration; and others

    2013-02-15

    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.

  11. Quiescent and Flaring Structure in RS Canum Venaticorum Stars

    NASA Astrophysics Data System (ADS)

    Sanz-Forcada, J.; Brickhouse, N. S.; Dupree, A. K.

    2002-05-01

    Four of the most active RS CVn stars (V711 Tau, II Peg, σ Gem, and UX Ari) have been observed for a total of 3 Ms with the Extreme Ultraviolet Explorer satellite (EUVE) between 1992 and 2000 January. Flaring and quiescent states of extreme ultraviolet spectra (λλ70-740) and light curves (λλ75-175) have been analyzed to provide emission measure distributions (EMD) for these systems in the range logTe(K)~5.6-7.4, based principally on iron lines. Flux measurements obtained with IUE and the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) complete the EMD in the lower temperature range [logTe(K)~4.0-5.6]. Frequent flaring activity has been found in the systems, including an increase during the rise phase by a factor of ~9 in the flux of σ Gem, the largest flare enhancement observed with EUVE. Analyses of the EUVE emission in the active single star AB Dor and the low-rotation giant star β Cet are also included. The EMDs are remarkably similar among all the stars, showing a narrow enhancement or ``bump'' around logTe(K)~6.9. These narrow bumps are apparently unrelated to rotation rate, spectral type, binarity, or evolutionary stage. Significant material is found at logTe(K)>~7.0 for the most active stars. Modulation of the EUV flux outside of flaring occurs in four of the stars (σ Gem, V711 Tau, UX Ari, AB Dor). The electron density ranges between Ne~1012 and ~1013 cm-3, measured at logTe(K)~7.0, and may reach higher values during flares. These densities and EMD values imply small scale sizes for emitting regions.

  12. Permanent active longitudes and activity cycles on RS CVn stars

    NASA Astrophysics Data System (ADS)

    Berdyugina, Svetlana V.; Tuominen, Ilkka

    1998-08-01

    A new analysis of the published long-term photometric observations has revealed permanent active-longitude structures in four RS CVn stars: EI Eri, II Peg, sigma Gem, and HR 7275. Two active longitudes separated by half of the period are found to dominate on the surface during all available seasons. The positions of the longitudes on three stars (EI Eri, II Peg, HR 7275) are migrating in the orbital reference frame, and there is no preferred orientation with respect to the line of centres in the binaries. The rate of migration is approximately constant. In case of sigma Gem the active longitude migration is synchronized with the orbital motion in the direction of the line of centres in the binary. The active region lifetimes can be longer than the time span of the observations (>=15 yr). The periods of the active longitude rotation are determined: for EI Eri 1fd 9510, for II Peg 6fd 7066, for sigma Gem 19fd 604, for HR 7275 28fd 263. Long-term activity cycles of the stars are discovered from the analysis of the relative contribution of the two longitudes to the photometric variability. One longitude is found to be usually more active than the other at a given moment, and the change of the activity level between the longitudes is cyclic with periods of years. The switch of the activity takes a much shorter time, about a few months, similar to the ``flip-flop'' phenomenon found for FK Com stars. Moments of switching are regarded as new tracers of the activity, and total cycles, which return activity to the same longitude, are found to be for EI Eri 9.0 yr, for II Peg 9.3 yr, for sigma Gem 14.9 yr, for HR 7275 17.5 yr.

  13. Theoretical studies of the RS cannum venaticorum stars

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1981-01-01

    Four areas of research were investigated: chromospheric modelling; starspot modelling; supersonic transition locus (STL) crossing; and STL crossing and T Tauri phenomena. Relationships among these areas of research are presented. Stellar structure and mass ejection for these stars were examined along with chromospheric analysis.

  14. MAXI/GSC detected a high state on an RS CVn star GT Mus

    NASA Astrophysics Data System (ADS)

    Sasaki, R.; Nakamura, Y.; Tsuboi, Y.; Nakahira, S.; Negoro, H.; Ueno, S.; Tomida, H.; Nakahira, S.; Ishikawa, M.; Nakagawa, Y. E.; Sugawara, Y.; Mihara, T.; Sugizaki, M.; Serino, M.; Iwakiri, W.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Isobe, N.; Sugita, S.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Kitaoka, Y.; Tsunemi, H.; Shomura, R.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Kawase, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Tanimoto, A.; Yamauchi, M.; Furuya, K.; Yamaoka, K.

    2016-07-01

    At 2016-07-16 19:18 UT , the MAXI/GSC nova alert system triggered on a bright source at a position consistent with that of an RS CVn star GT Mus. The flux increased from 2016-07-16 13:08:30 UT to 2016-07-16 19:18 UT (the trigger time).

  15. The Motion Verified Red Stars (MoVeRS) Catalog and Low-Mass Field Stars with Warm Dust

    NASA Astrophysics Data System (ADS)

    Theissen, Christopher; West, Andrew A.; Dhital, Saurav

    2016-01-01

    We present the Motion Verified Red Stars (MoVeRS) catalog of proper motion selected low-mass stars from SDSS, 2MASS, and WISE. These surveys provide a time baseline of ~12 years for sources found in all three surveys, and a precision better than 10 mas/year.The MoVeRS catalog is augmented with proper motions from SDSS+USNO-B and the full sample contains 8,735,004 photometric point-sources selected based on colors and their significant (2σ) proper motions. This catalog will be useful for finding new low-mass common proper motion systems, along with providing a large input catalog for numerous studies of low-mass stars. In addition, we use the MoVeRS catalog to present a preliminary sample of low-mass field stars exhibiting signatures of warm dust (mid-infrared excesses). Such systems are thought to originate from collisions of terrestrial planets, raising even more questions about the habitability of planetary systems around low-mass stars.

  16. VizieR Online Data Catalog: Motion Verified Red Stars (MoVeRS) (Theissen+, 2016)

    NASA Astrophysics Data System (ADS)

    Theissen, C. A.; West, A. A.; Dhital, S.

    2015-09-01

    We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS-DR10, Two-Micron All-Sky Survey (2MASS) Point Source Catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r-i, i-z, r-z, z-J, and z-W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2-sigma uncertainty were included. Our Motion Verified Red Stars (MoVeRS) catalog is available through SDSS CasJobs and VizieR. (2 data files).

  17. MAXI/GSC detection of a possible X-ray flare from an RS CVn star HR5110

    NASA Astrophysics Data System (ADS)

    Sasaki, R.; Tsuboi, Y.; Nakamura, Y.; Serino, M.; Ueno, S.; Tomida, H.; Nakahira, S.; Ishikawa, M.; Nakagawa, Y. E.; Sugawara, Y.; Mihara, T.; Sugizaki, M.; Iwakiri, W.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Isobe, N.; Sugita, S.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Kitaoka, Y.; Tsunemi, H.; Shomura, R.; Negoro, H.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Kawase, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Tanimoto, A.; Yamauchi, M.; Furuya, K.; Yamaoka, K.

    2016-06-01

    MAXI/GSC observed a possible X-ray flare from an RS CVn star HR5110. The MAXI/GSC nova alert system triggered on the flare-like event from the position consistent with the RS CVn system HR5110 during a scan transit at 09:19:00 UT on June 12th 2016.

  18. Southern RS CVn systems - Candidate list. [spectral catalog of variable binary stars

    NASA Technical Reports Server (NTRS)

    Weiler, E. J.; Stencel, R. E.

    1979-01-01

    A list of 43 candidate RS CVn binary systems in the far southern hemisphere of the sky (south of -40 deg declination) is presented. The candidate systems were selected from the first two volumes of the Michigan Spectral Catalog (1975, 1978), which provides MK classifications for southern HD stars and identifies any unusual characteristics noted for individual stellar spectra. The selection criteria used were: (1) the occurrence of Ca II H and K emission; (2) known or suspected binary nature; (3) regular light variations of zero to one magnitude; and (4) spectral type between F0 and K2 and luminosity less than bright giant (II).

  19. HE 0017+0055: A probable pulsating CEMP-rs star and long-period binary

    NASA Astrophysics Data System (ADS)

    Jorissen, A.; Hansen, T.; Van Eck, S.; Andersen, J.; Nordström, B.; Siess, L.; Torres, G.; Masseron, T.; Van Winckel, H.

    2016-02-01

    Context. A large fraction of the carbon-enhanced, extremely metal-poor halo giants ([Fe/H] < -2.5) are also strongly enriched in neutron-capture elements from the s process (CEMP-s stars). The conventional explanation for the properties of these stars is mass transfer from a nearby binary companion on the asymptotic giant branch (AGB). This scenario leads to a number of testable predictions in terms of the properties of the putative binary system and the resulting abundance pattern. Among the CEMP stars, some stars further exhibit overabundances in r-process elements on top of the s-process enrichment, and are tagged CEMP-rs stars. Although the nucleosynthesis process responsible for this kind of mixed abundance pattern is still under debate, CEMP-rs stars seem to belong to binary systems as do CEMP-s stars. Aims: Our aim is to present and analyse in detail our comprehensive data set of systematic radial-velocity measurements and high-resolution spectroscopy of the CEMP star HE 0017+0055. Methods: Our precise radial-velocity monitoring of HE 0017+0055 over 2940 days (8 yr) with the Nordic Optical Telescope and Mercator telescopes exhibits variability, with a period of 384 d and amplitude of 540 ± 27 m s-1 superimposed on a nearly linear long-term decline of ~1 m s-1 day-1. We used high-resolution HERMES/Mercator and Keck/HIRES spectra to derive elemental abundances with 1D LTE MARCS models. A metallicity of [Fe/H] ~ -2.4 is found, along with s-process overabundances of the order of 2 dex (with the exception of [Y/Fe] ~ + 0.5), and most notably overabundances of r-process elements like Sm, Eu, Dy, and Er in the range 0.9-2.0 dex. With [Ba/Fe] > 1.9 dex and [Eu/Fe] = 2.3 dex, HE 0017+0055 is a CEMP-rs star. We used the derived atmospheric parameters and abundances to infer HE 0017+0055 evolutionary status from a comparison with evolutionary tracks. Results: HE 0017+0055 appears to be a giant star below the tip of the red giant branch. The s-process pollution must

  20. Long-term chromospheric activity of non-eclipsing RS CVn-type stars

    NASA Astrophysics Data System (ADS)

    Buccino, A. P.; Mauas, P. J. D.

    2009-02-01

    Context: The IUE database provides several UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE. Aims: Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22 468 (V711 Tau, HR 1099, K1IV+G5V), HD 21 242 (UX Ari, K0IV+G5V), and HD 224 085 (II Peg, K2IV). Methods: We first obtained the Mount Wilson index S from the IUE high and low-resolution spectra. Secondly, we used the Lomb-Scargle periodogram to analyse the mean annual index < S> and the amplitude of the rotational modulation of the index S. Results: For HD 22 468 (V711 Tau, HR 1099), we find a possible chromospheric cycle with a period of ~18 years and a shorter cycle with a period of ~3 years, which could be associated to a chromospheric “flip-flop” cycle. The data of HD 224 085 (II Peg) also suggest a chromospheric cycle of ~21 years and a flip-flop cycle of ~9 years. Finally, we obtained a possible chromospheric cycle of ~7 years for HD 21 242 (UX Ari).

  1. The dusty AGB star RS CrB: first mid-infrared interferometric observations with the Keck telescopes

    NASA Technical Reports Server (NTRS)

    Mennesson, B.; Koresko, C.; Creech-Eakman, M. J.; Serabyn, E.; Colavita, M. M; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Crawford, S.; Dahl, W.; Fanson, J.; Felizardo, C.; Garcia, J.; Gathright, J.; Herstein, J.; Hovland, E.; Hrynevych, M.; Johansson, E.; Le Mignant, D.; Ligon, R.; Millan-Gabet, R.; Moore, J.; Neyman, C.; Palmer, D.

    2005-01-01

    We report interferometric observations of the semiregular variable star RS CrB, a red giant with strong silicate emission features. The data were among the first long-baseline mid-infrared stellar fringes obtained between the Keck telescopes, using parts of the new nulling beam combiner.

  2. MAXI/GSC detection of a possible X-ray flare from an RS CVn star AR Psc

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Tsuboi, Y.; Sasaki, R.; Serino, M.; Nakahira, S.; Ueno, S.; Tomida, H.; Ishikawa, M.; Nakagawa, Y. E.; Sugawara, Y.; Mihara, T.; Sugizaki, M.; Iwakiri, W.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Isobe, N.; Sugita, S.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Kitaoka, Y.; Tsunemi, H.; Shomura, R.; Negoro, H.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Kawase, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Tanimoto, A.; Yamauchi, M.; Furuya, K.; Yamaoka, K.

    2016-07-01

    On July 30th 2016, the MAXI/GSC nova-alert system triggered on a possible X-ray flare from an RS CVn star AR Psc. The intense X-ray emission was detected from a transit starting at 21:52 UT on July 29th 2016 to the next transit starting at 23:25 UT on 29th.

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

    NASA Astrophysics Data System (ADS)

    Dogˇru, D.; Erdem, A.; Dogˇru, S. S.

    2009-11-01

    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.

  4. Elemental abundance analyses with Coudé Echelle spectrograms from the TÜBİTAK National Observatory of Turkey: I. The HgMn stars 11 Per, HR 2801, and ν Cnc

    NASA Astrophysics Data System (ADS)

    Adelman, S. J.; Yüce, K.

    2010-08-01

    Using coadded spectrograms taken with the Coudé Echelle Spectrograph (CES) of the 1.50-m Russian-Turkish Telescope of the TÜBİTAK National Observatory (TUG) near Antalya in Turkey, elemental abundance analyses of three HgMn stars 11 Per, HR 2801, and ν Cnc were performed. Comparisons are made with spectra obtained with the long camera of the Dominion Astrophysical Observatory (DAO) coudé spectrograph and its SITe4 CCD. The CES equivalent widths are about 12% larger than that for the DAO long camera. Our first results from TUG data/spectra show that all three stars exhibit the Hg II λ3984 line and somewhat diverse abundance patterns. 11 Per tends to have underabundant light elements with underabundant and overabundant Fe-peak elements. HR 2801 has mostly underabundant elements, with a few elements having solar abundances while N and Mn are overabundant. The coolest star ν Cnc has light elements having mostly solar abundances, overabundant iron group abundances, and very overabundant SrYZr and Ba. Comparisons with the abundance patterns of other HgMn stars show that they have a wide diversity of abundance patterns. Tables 2 and 6 are available at the CDS via http://cdsarc.u-strasbg.fr/cgi-bin/qcat?J/AN/331/785.

  5. CNC Programming I.

    ERIC Educational Resources Information Center

    Casey, Joe

    This document contains five units for a 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 manually. Each unit consists of an introduction, instructional objectives, learning materials, learning activities,…

  6. Carney complex (CNC).

    PubMed

    Bertherat, Jérôme

    2006-01-01

    The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65% of CNC index cases, and may be present in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD. PMID

  7. Rotational modulation and flares on RS Canum Venaticorum and BY Draconis stars. 18: Coordinated VLA, ROSAT, and IUE observations of RS CVn binaries

    NASA Technical Reports Server (NTRS)

    Fox, David C.; Linsky, Jeffrey L.; Veale, Anthony; Dempsey, Robert C.; Brown, Alex; Neff, James E.; Pagano, Isabella; Rodono, Marcello; Bromage, Gordon E.; Kuerster, Martin

    1994-01-01

    As part of a coordinated program of multi-wavelength observations of RS CVn close binary systems, we observed 15 systems with the Very Large Array (VLA) and 10 systems with IUE, simultaneously or nearly simultaneously with the ROSAT All Sky Survey observations of these stars. Of the 22 systems observed with ROSAT, three were observed both by IUE and the VLA. Radio observations were made at 3.6, 6 and 20 cm. Of the 15 observed RS CVn systems, we detected 11 with greater than 4 sigma confidence at one or more wavelengths. The IUE observations were made within the RIASS (ROSAT-IUE All Sky Survey) program. We present the results of the VLA observations, along with the corresponding subsets of the ROSAT Position Sensitive Proportional Counter (PSPC) X-ray and Wide Field Camera (WFC) XUV survey, and RIASS IUE observations. We obtained an extended VLA/IUE/ROSAT simultaneous coverage of one system, TY Pyx, covering more than one orbital period. These observations reveal that the quiescent radio flux of TY Pyx is relatively constant over time scales of up to 7 hours, but that it did change by a factor of 3 over 24 hours, probably due to a flare on 1990 Nov. 12. The UV, XUV and X-ray fluxes do not show large day-to-day or phase-related variability. The observation of the decay phase of a radio flare on EI Eri, with no accompanying X-ray or XUV flare, suggests that the lack of a strong correlation between X-ray and radio flares previously noted for dMe flare stars holds for RS CVn systems as well. We suggest that the radio flare may have been due to a coherent emission process such as electron cyclotron emission. The simultaneous measurements presented here provide a unique test of the general correlation between radio and soft X-ray luminosities, L(sub radio) approximately L(sub x exp m) (Drake et al. 1989) with a power-law slope close to unity, which was previously derived using data obtained years apart. Our derived slopes are consistent with and thus support the general

  8. Rotational modulation and flares on RS CVn and BY Dra stars. IV - The spatially resolved chromosphere of AR Lacertae

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    The authors observed the RS Canum Venaticorum system AR Lacertae systematically over an orbital period with the International Ultraviolet Explorer in October 1983. Contemporaneous radio observations were obtained at the VLA. The spectra of the Mg II k emission line were analyzed using a Doppler imaging technique. In this way, three discrete regions of emission were identified in the outer atmosphere of the K star-two 'plages' and a chromospheric brightening that was related to a radio flare. The widths of the plage profiles indicate that the two plages together cover about 2 percent of the visible stellar hemisphere, and their v sin i values indicate that they lie close to the equator of the K star. The Mg II k surface flux in the plages is about five times the mean Mg II k surface flux of the K star.

  9. CAD/CAM/CNC.

    ERIC Educational Resources Information Center

    Domermuth, Dave; And Others

    1996-01-01

    Includes "Quick Start CNC (computer numerical control) with a Vacuum Filter and Laminated Plastic" (Domermuth); "School and Industry Cooperate for Mutual Benefit" (Buckler); and "CAD (computer-assisted drafting) Careers--What Professionals Have to Say" (Skinner). (JOW)

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  11. On the coronae of rapidly rotating stars. I - The relation between rotation and coronal activity in RS CVn systems

    NASA Technical Reports Server (NTRS)

    Walter, F. M.; Bowyer, S.

    1981-01-01

    Soft X-ray observations are presented of a nearly complete sample of RS Canum Venaticorum systems taken with the Einstein X-ray Observatory. It is shown that the quiescent coronal activity, as measured by the ratio of the X-ray to bolometric flux, is directly proportional to the angular velocity of the star with the active chromosphere in these systems. This relation is found to hold over two decades in angular velocity. It is also found that the stellar surface gravity has no obvious influence on the ratio of the X-ray luminosity to the bolometric luminosity over two decades in surface gravity. It is pointed out that the linear relation between the ratio of the X-ray luminosity to the bolometric luminosity on the one hand, and the angular velocity, on the other, holds important implications for dynamo theories of the generation of stellar magnetic fields.

  12. Multiple wavelength microwave observations of the RS Canum Venaticorum stars UX Arietis, HR 1099, HR 5110, and II Pegasi

    SciTech Connect

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

    1987-01-01

    The variabilities, core size and magnetic field of the RS CVn star UX Arietis was measured with the VLA at pairs of frequencies near 1415 MHz and 4835 MHz on June 10, 1985. Data were also gathered on HR 1099, HR 5110 and II Peg. UX Arietis exhibited variability on time scales ranging from 30 sec to 1 hr at 4835 MHz, but no detectable variations at 1415 MHz. An upper limit of 900 billion cm was placed on the size of the core emitting region, which is estimated to have a magnetic field strength of 15 G. The 30 sec variations are attributed to absorption by thermal plasma between the G5 and K1 companions of the UX Arietis system. 37 references.

  13. Title: MAXI/GSC detected an intense X-ray flare from an RS CVn star VY Ari

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Sasaki, R.; Tsuboi, Y.; Negoro, H.; Ueno, S.; Tomida, H.; Nakahira, S.; Ishikawa, M.; Nakagawa, Y. E.; Sugawara, Y.; Mihara, T.; Sugizaki, M.; Serino, M.; Iwakiri, W.; Shidatsu, M.; Sugimoto, J.; Takagi, T.; Matsuoka, M.; Kawai, N.; Isobe, N.; Sugita, S.; Yoshii, T.; Tachibana, Y.; Ono, Y.; Fujiwara, T.; Yoshida, A.; Sakamoto, T.; Kawakubo, Y.; Kitaoka, Y.; Tsunemi, H.; Shomura, R.; Nakajima, M.; Tanaka, K.; Masumitsu, T.; Kawase, T.; Ueda, Y.; Kawamuro, T.; Hori, T.; Tanimoto, A.; Yamauchi, M.; Furuya, K.; Yamaoka, K.

    2016-05-01

    On May 12 2016, the MAXI/GSC detected an enhanced X-ray emission at a position consistent with that of an RS CVn star VY Ari. The flux peak was observed at a transit starting at 12:34 UT on 11 May 2016 with a value of 146+-35 mCrab (90% error) in the 4-10 keV band, corresponding to a luminosity of 5 & times1032 ergs/s for an assumed distance of 44 pc. At the next scan starting at 14:08 on 11 May 2016, the observed flux was 83+-26 mCrab (90% error) in the 4-10 keV, corresponding to a luminosity of 4 & times1032 ergs/s.

  14. The Hamburg/ESO R-process Enhanced Star survey (HERES). VIII. The r+s star HE 1405-0822

    NASA Astrophysics Data System (ADS)

    Cui, W. Y.; Sivarani, T.; Christlieb, N.

    2013-10-01

    Aims: The aim of this study is a detailed abundance analysis of the newly discovered r-rich star HE 1405-0822, which has [Fe/H] = -2.40. This star shows enhancements of both r- and s-elements, [Ba/Fe] = + 1.95 and [Eu/Fe] = 1.54, for which reason it is called r+s star. Methods: Stellar parameters and element abundances were determined by analyzing high-quality VLT/UVES spectra. We used Fe I line excitation equilibria to derive the effective temperature. The surface gravity was calculated from the Fe i/Fe ii and Ti i/Ti ii equilibria. Results: We determined accurate abundances for 39 elements, including 19 neutron-capture elements. HE 1405-0822 is a red giant. Its strong enhancements of C, N, and s-elements are the consequence of enrichment by a former AGB companion with an initial mass of less than 3 M⊙. The heavy n-capture element abundances (including Eu, Yb, and Hf) seen in HE 1405-0822 do not agree with the r-process pattern seen in strongly r-process-enhanced stars. We discuss possible enrichment scenarios for this star. The enhanced α elements can be explained as the result of enrichment by supernovae of type II. Na and Mg may have partly been synthesized in a former AGB companion, when the primary 22Ne acted as a neutron poison in the 13C-pocket. Based on observations collected at the European Southern Observatory, Paranal, Chile (Proposal numbers 170.D-0010G, and 170.D-0010J).Tables 5, 6 are available in electronic form at http://www.aanda.org

  15. Difference at chromospheric levels between rs cvn-type binaries, active and quiet chromosphere single stars, and active and quiet regions in the sun

    SciTech Connect

    Linsky, J.L.

    1980-01-01

    This paper summarizes the differences in the properties of active chromospheres compared with quiet chromospheres by comparing active and quiet regions on the Sun, active and quiet chromosphere stars, and the very active chromospheres seen in close binary systems with chromospheres of single stars. In particular, the chromospheres of the RS CVn-type binary systems UX Arietis and HR 1099 and the chromosphere of UX Arietis during a flare are modeled.

  16. Degraded RNA transcript stable regions (StaRs) as targets for enhanced forensic RNA body fluid identification.

    PubMed

    Lin, Meng-Han; Albani, Patricia P; Fleming, Rachel

    2016-01-01

    The detection of messenger RNA (mRNA) using reverse transcriptase PCR (RT-PCR) is becoming common practice for forensic body fluid identification. However, the degraded and scarce nature of RNA from forensic samples mean that mRNA transcripts are not consistently detected or remain undetected in practice. Conventional primer design for RT-PCR (and quantitative RT-PCR) includes targeting primers to span exon-exon boundaries or by having the primers on two separate exons, and satisfying common primer thermodynamic criteria. We have found that the conventional placement of primers is not always optimal for obtaining reproducible results from degraded samples. Using massively parallel sequencing data from degraded body fluids, we designed primers to amplify transcript regions of high read coverage, hence, higher stability, and compared these with primers designed using conventional methodology. Our findings are that primers designed for transcript regions of higher read coverage resulted in vastly improved detection of mRNA transcripts that were not previously detected or were not consistently detected in the same samples using conventional primers. We developed a new concept whereby primers targeted to transcript stable regions (StaRs) are able to consistently and specifically amplify a wide range of RNA biomarkers in various body fluids of varying degradation levels.

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

    SciTech Connect

    Richards, Mercedes T.; Agafonov, Michail I.; Sharova, Olga I. E-mail: agfn@nirfi.sci-nnov.ru

    2012-11-20

    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.

  18. 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)

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

    1989-01-01

    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.

  19. Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Astrophysics Data System (ADS)

    Flynn, C. J.; Dahlgren, R. P.; Dunagan, S. E.; Johnson, R. R.; Kacenelenbogen, M. S.; LeBlanc, S. E.; Livingston, J. M.; Redemann, J.; Schmid, B.; Segal-Rosenhaimer, M.; Shinozuka, Y.; Zhang, Q.; Schmidt, S.; Holben, B. N.; Sinyuk, A.; Hair, J. W.; Anderson, B. E.; Ziemba, L. D.

    2015-12-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP I & II campaigns, and NASA's SEAC4RS and ARISE campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2, and from in situ measurements.

  20. Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Technical Reports Server (NTRS)

    Dunagan, Stephen E.

    2016-01-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET (Aerosol Robotic Network)-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP (Two-Column Aerosol Project) I & II campaigns, and NASA's SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) and ARISE (Arctic Radiation - IceBridge Sea & Ice Experiment) campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2 (High Spectral Resolution Lidar), and from in situ measurements.

  1. CNC Preparation Meets Manufacturing Opportunity

    ERIC Educational Resources Information Center

    Cassola, Joel

    2006-01-01

    This article features the machining technology program at Cape Fear Community College (CFCC) of Wilmington, North Carolina. North Carolina's Cape Fear Community College is working to meet diverse industry needs through its CNC training. The school's program has gained the attention of the local manufacturing community and students when it shifted…

  2. Discovery of phase-locked variable polarization in an RS Canum Venaticorum-like star, HR 5110

    NASA Technical Reports Server (NTRS)

    Barbour, M. S.; Kemp, J. C.

    1981-01-01

    Using measurements on 79 nights in 1980 January-August, it is established that the polarization in the ultraviolet (U band) varies synchronously on the known binary period of 2.6132 days, with a peak-to-peak amplitude of 0.03%. The pattern is mainly second harmonic in character, as typical of binary star examples such as Algol and Upsilon Her. Reflection by the cooler star, by a plasma concentration, or both, is suggested. The scale of the polarization seems to be consistent with Rayleigh scattering by neutral hydrogen on the cooler star, and a roughly lambda to the -4th wavelength dependence should be searched for. The QU curve suggests a sizeable inclination for the system, of about 45 deg, but this is preliminary. Separately, a possible weak periodicity might be present on a subsidiary period, conceivably related to a rotating star spot.

  3. ROSSITER-MCLAUGHLIN OBSERVATIONS OF 55 Cnc e

    SciTech Connect

    López-Morales, Mercedes; Rodler, Florian; Dumusque, Xavier; Buchhave, Lars A.; Latham, David W.; Triaud, Amaury H. M. J.; Harutyunyan, Avet; Hoyer, Sergio; Alonso, Roi; Gillon, Michaël; Kaib, Nathan A.; Lovis, Christophe; Pepe, Francesco; Queloz, Didier; Ségransan, Damien; Udry, Stéphane; Raymond, Sean N.; Waldmann, Ingo P.

    2014-09-10

    We present Rossiter-McLaughlin observations of the transiting super-Earth 55 Cnc e collected during six transit events between 2012 January and 2013 November with HARPS and HARPS-N. We detect no radial velocity signal above 35 cm s{sup –1} (3σ) and confine the stellar v sin i {sub *} to 0.2 ± 0.5 km s{sup –1}. The star appears to be a very slow rotator, producing a very low amplitude Rossiter-McLaughlin effect. Given such a low amplitude, the Rossiter-McLaughlin effect of 55 Cnc e is undetected in our data, and any spin-orbit angle of the system remains possible. We also performed Doppler tomography and reach a similar conclusion. Our results offer a glimpse of the capacity of future instrumentation to study low amplitude Rossiter-McLaughlin effects produced by super-Earths.

  4. Motion Verified Red Stars (MoVeRS): A Catalog of Proper Motion Selected Low-mass Stars from WISE, SDSS, and 2MASS

    NASA Astrophysics Data System (ADS)

    Theissen, Christopher A.; West, Andrew A.; Dhital, Saurav

    2016-02-01

    We present a photometric catalog of 8,735,004 proper motion selected low-mass stars (KML-spectral types) within the Sloan Digital Sky Survey (SDSS) footprint, from the combined SDSS Data Release 10 (DR10), Two Micron All-Sky Survey (2MASS) point-source catalog (PSC), and Wide-field Infrared Survey Explorer (WISE) AllWISE catalog. Stars were selected using r - i, i - z, r - z, z - J, and z - W1 colors, and SDSS, WISE, and 2MASS astrometry was combined to compute proper motions. The resulting 3,518,150 stars were augmented with proper motions for 5,216,854 earlier type stars from the combined SDSS and United States Naval Observatory B1.0 catalog (USNO-B). We used SDSS+USNO-B proper motions to determine the best criteria for selecting a clean sample of stars. Only stars whose proper motions were greater than their 2σ uncertainty were included. Our Motion Verified Red Stars catalog is available through SDSS CasJobs and VizieR.

  5. BD Andromedae: A new short-period RS CVn eclipsing binary star with a distant tertiary body in a highly eccentric orbit

    SciTech Connect

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

    2014-06-20

    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 {sub 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.

  6. Chromospherically active stars. III - HD 26337 = EI Eri: An RS CVn candidate for the Doppler-imaging technique

    NASA Technical Reports Server (NTRS)

    Fekel, Francis C.; Quigley, Robert; Gillies, Kim; Africano, John L.

    1987-01-01

    Spectroscopic observations of the chromospherically active G5 IV single-lined binary HD 26337 = EI Eri are presented. An orbital period of 1.94722 days is found for the star. It has moderately strong Ca II H and K emission and strong ultraviolet emission features, while H-alpha is a weak absorption feature that is variable in strength. The inclination of the system is 46 + or - 12 deg, and the unseen secondary is probably a late K or early M dwarf. The v sin i of the primary is 50 + or - 3 km/s, resulting in a minimum radius of 1.9 + or - 0.1 solar radius. The star is within the required limits for Doppler imaging. The primary is close to filling its Roche lobe, resulting in a strong constraint that the mass ratio is 2.6 or greater, with a primary mass of at least 1.4 solar mass. The distance to the system is estimated at 75 pc.

  7. Synthetical Reliability Analysis Model of CNC Software System

    NASA Astrophysics Data System (ADS)

    Xu, Yue; Xia, Yinjie; Wan, Yi

    CNC technology is the core of advanced manufacturing technology, and CNC software system is the very important part of numerical control system. The entire CNC system will not work normally, once the potential failure makes the software invalid. As to the current study of CNC sysytem, in use of the FAULT glitch tree, established a glitch tree for the CNC system; find the minimum cut sets with Fussed method and then according to the probability of several common glitches, make quantitative analysis in the reliability of the CNC system so that scientific ways can be provided for the reliability design, maintenance and management of the CNC system.

  8. A Benchmark Infrared Characterisation of the Super-Earth 55 Cnc e

    NASA Astrophysics Data System (ADS)

    Demory, Brice-Olivier; Kataria, Tiffany; Lewis, Nikole; Krick, Jessica; Queloz, Didier; Gillon, Michael; Stamenkovic, Vlada; Madhusudhan, Nikku; Fortney, Jonathan; de Wit, Julien; Kane, Stephen

    2014-12-01

    The Kepler mission and radial-velocity surveys have revealed that super-Earth exoplanets are not only ubiquitous in our galaxy but also very diverse in terms of physical properties. However, very little is known about their nature because of the paucity of suitable targets amenable to detailed characterization. Two super-Earths, GJ1214b and 55Cnc e, orbit stars that are bright enough to enable detailed atmospheric and interior composition studies, which are crucial to improve our understanding of this class of exoplanets. As of today, 55Cnc e is the only super Earth amenable to occultation and phase curve infrared photometry, as well as a prime target to understand the nature of highly irradiated super Earths. In the past two years, Spitzer observations of 55 Cnc e resulted in photometric lightcurves of unprecedented quality, thanks to the brightness of its host star. We propose an observing program of 180 hours to pursue this effort. Our main goal is to determine whether 55 Cnc e harbors an atmosphere or not. We propose to obtain four orbital phase curves of 55 Cnc e at 4.5 microns and four other at 3.6 microns. Our observations will unambiguously determine whether 55 Cnc e is volatile-poor or volatile-rich. We will also measure for the first time the 3D climate patterns in a super-Earth atmosphere. Finally, our program will deliver precise transit, occultation and phase-curve photometry that will constitute an important legacy regarding the characterization of a super-Earth exoplanet, well in advance of JWST.

  9. Improving Energy Efficiency in CNC Machining

    NASA Astrophysics Data System (ADS)

    Pavanaskar, Sushrut S.

    We present our work on analyzing and improving the energy efficiency of multi-axis CNC milling process. Due to the differences in energy consumption behavior, we treat 3- and 5-axis CNC machines separately in our work. For 3-axis CNC machines, we first propose an energy model that estimates the energy requirement for machining a component on a specified 3-axis CNC milling machine. Our model makes machine-specific predictions of energy requirements while also considering the geometric aspects of the machining toolpath. Our model - and the associated software tool - facilitate direct comparison of various alternative toolpath strategies based on their energy-consumption performance. Further, we identify key factors in toolpath planning that affect energy consumption in CNC machining. We then use this knowledge to propose and demonstrate a novel toolpath planning strategy that may be used to generate new toolpaths that are inherently energy-efficient, inspired by research on digital micrography -- a form of computational art. For 5-axis CNC machines, the process planning problem consists of several sub-problems that researchers have traditionally solved separately to obtain an approximate solution. After illustrating the need to solve all sub-problems simultaneously for a truly optimal solution, we propose a unified formulation based on configuration space theory. We apply our formulation to solve a problem variant that retains key characteristics of the full problem but has lower dimensionality, allowing visualization in 2D. Given the complexity of the full 5-axis toolpath planning problem, our unified formulation represents an important step towards obtaining a truly optimal solution. With this work on the two types of CNC machines, we demonstrate that without changing the current infrastructure or business practices, machine-specific, geometry-based, customized toolpath planning can save energy in CNC machining.

  10. MULTIBAND PHOTOMETRIC AND SPECTROSCOPIC ANALYSIS OF HV Cnc

    SciTech Connect

    Gökay, G.; Gürol, B.; Derman, E.

    2013-11-01

    In this paper, radial velocity and VI- and JHK{sub S} - (Two Micron All Sky Survey) band photometric data of the detached system HV Cnc have been analyzed. The primary component of HV Cnc, which is a member of the M67 cluster, is suspected to be either a blue straggler or turn-off star. The system is a single-lined spectroscopic binary and its light curve shows a total eclipse. Spectroscopic observations of the system revealed the third component, which shows contribution to the total light of the system. Light curve and radial velocity data have been analyzed using the Wilson-Devinney (W-D) code and JHK{sub S} filter definitions computed for the W-D code in this work. Our analysis shows that the mass and radius of the primary and secondary components are 1.31 M {sub ☉}, 0.52 M {sub ☉}, 1.87 R {sub ☉}, and 0.48 R {sub ☉}, respectively. All results are compared with previously published literature values and discussed.

  11. An intelligent CNC machine control system architecture

    SciTech Connect

    Miller, D.J.; Loucks, C.S.

    1996-10-01

    Intelligent, agile manufacturing relies on automated programming of digitally controlled processes. Currently, processes such as Computer Numerically Controlled (CNC) machining are difficult to automate because of highly restrictive controllers and poor software environments. It is also difficult to utilize sensors and process models for adaptive control, or to integrate machining processes with other tasks within a factory floor setting. As part of a Laboratory Directed Research and Development (LDRD) program, a CNC machine control system architecture based on object-oriented design and graphical programming has been developed to address some of these problems and to demonstrate automated agile machining applications using platform-independent software.

  12. Development of Lathe Attachment for a CNC Machine

    NASA Astrophysics Data System (ADS)

    Roy, V.; Kumar, S.

    2013-04-01

    A lathe attachment has been developed for an existing CNC machine (installed with rapid prototyping attachment) using conceptual design. The CNC machine operates on mechatronic controls and a computer interface called CAMSOFT, and is used as a CNC Lathe after installing the respective attachment to it. The conceptual design phase, starts from an idea and different components of the lathe are designed as attachment using CAD modelling and is followed by fabrication phase. The lathe attachment is successfully developed and is installed to the CNC machine. The working of the CNC Lathe attachment is checked by making some machining operation like turning and thread cutting. The machining operations are successfully done. The CNC machine becomes multifunctional with the presently developed lathe attachment and the existing RP (rapid prototyping) attachment, and can be used accordingly by installing the respective attachment to it. The CNC machine is useful for carrying research work in both the fields, when installed with the appropriate attachment.

  13. 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)

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

    1987-01-01

    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.

  14. The search for radio emission from the 55 Cnc exoplanetary system using LOFAR

    NASA Astrophysics Data System (ADS)

    Turner, Jake; Griessmeier, Jean-Mathias; Zarka, Philippe

    2016-10-01

    Detection of radio emission from exoplanets can provide information on the star-planet system that is very difficult or impossible to study otherwise, such as the planet's magnetic field, magnetosphere, rotation period, orbit inclination, and star-planet interactions. Such a detection in the radio would open up a whole new field in exoplanets, however, currently there are no confirmed detections of an exoplanet at radio frequencies. In this study, we search for non-thermal radio emission from 55 Cnc, an exoplanetary system with 5 planets. 55 Cnc is among the best targets for this search according to theoretical studies. We observed for 18 hours with the Low-Frequency Array (LOFAR) in the frequency range 26-73 MHz with full-polarization and covered the entire orbital phases of the innermost planet. During the observations four beams were recorded simultaneously on 55 Cnc, a patch of nearby "empty" sky, the nearby pulsar B0823+26, and a bright radio source in the field. The extra beams make this setup unique since they can be used for control of the telescope gain and to verify that a detection in the exoplanet beam is not a false-positive detection (e.g. ionospheric fluctuations). An automatic pipeline was created to automatically find Radio Frequency Interference (RFI) and to search for emission in the exoplanet beam. We will apply this observational technique and pipeline to more of the theoretically best candidates in the future.

  15. CNC Machining Of The Complex Copper Electrodes

    NASA Astrophysics Data System (ADS)

    Popan, Ioan Alexandru; Balc, Nicolae; Popan, Alina

    2015-07-01

    This paper presents the machining process of the complex copper electrodes. Machining of the complex shapes in copper is difficult because this material is soft and sticky. This research presents the main steps for processing those copper electrodes at a high dimensional accuracy and a good surface quality. Special tooling solutions are required for this machining process and optimal process parameters have been found for the accurate CNC equipment, using smart CAD/CAM software.

  16. Stars

    NASA Astrophysics Data System (ADS)

    Capelato, Hugo Vicente

    1999-01-01

    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.

  17. Understanding and Writing G & M Code for CNC Machines

    ERIC Educational Resources Information Center

    Loveland, Thomas

    2012-01-01

    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…

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

    ERIC Educational Resources Information Center

    Casey, Joe

    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,…

  19. CO And HI Emission from The Circumstellar Envelopes of Some Evolved Stars*

    NASA Astrophysics Data System (ADS)

    Diep, P. N.; Hoai, D. T.; Nhung, P.; Tuan-Anh, P.; Le Bertre, T.; Winters, J. M.; Matthews, L. D.; Phuong, N. T.; Thao, N. T.; Darriulat, P.

    2016-02-01

    Studies of the CO and HI radio emission of some evolved stars are presented using data collected by the IRAM Plateau de Bure interferometer and Pico Veleta telescope, the Nançay Radio Telescope and the JVLA and ALMA arrays. Approximate axial symmetry of the physical and kinematic properties of the circumstellar envelope (CSE) are observed in CO emission , in particular, from RS Cnc, EP Aqr and the Red Rectangle. A common feature is the presence of a bipolar outflow causing an enhanced wind velocity in the polar directions. I emission extends to larger radial distances than probed by CO emission and displays features related to the interaction between the stellar outflow and interstellar matter. With its unprecedented sensitivity, FAST will open a new window on such studies. Its potential in this domain is briefly illustrated.

  20. Ground-based Transit Observations of the Super-Earth 55 Cnc e

    NASA Astrophysics Data System (ADS)

    de Mooij, E. J. W.; López-Morales, M.; Karjalainen, R.; Hrudkova, M.; Jayawardhana, Ray

    2014-12-01

    We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ~700 and ~250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190-0.0027+0.0023 from the 2013 observations and 0.0200-0.0018+0.0017 from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198-0.0014+0.0013. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.

  1. GROUND-BASED TRANSIT OBSERVATIONS OF THE SUPER-EARTH 55 Cnc e

    SciTech Connect

    De Mooij, E. J. W.; López-Morales, M.; Karjalainen, R.; Hrudkova, M.; Jayawardhana, Ray

    2014-12-20

    We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ∼700 and ∼250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190{sub −0.0027}{sup +0.0023} from the 2013 observations and 0.0200{sub −0.0018}{sup +0.0017} from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198{sub −0.0014}{sup +0.0013}. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.

  2. 28SiO v = 0 J = 1-0 emission from evolved stars

    NASA Astrophysics Data System (ADS)

    de Vicente, P.; Bujarrabal, V.; Díaz-Pulido, A.; Albo, C.; Alcolea, J.; Barcia, A.; Barbas, L.; Bolaño, R.; Colomer, F.; Diez, M. C.; Gallego, J. D.; Gómez-González, J.; López-Fernández, I.; López-Fernández, J. A.; López-Pérez, J. A.; Malo, I.; Moreno, A.; Patino, M.; Serna, J. M.; Tercero, F.; Vaquero, B.

    2016-05-01

    Aims: Observations of 28SiO v = 0J = 1-0 line emission (7-mm wavelength) from asymptotic giant branch (AGB) stars show in some cases peculiar profiles, composed of a central intense component plus a wider plateau. Very similar profiles have been observed in CO lines from some AGB stars and most post-AGB nebulae and, in these cases, they are clearly associated with the presence of conspicuous axial symmetry and bipolar dynamics. We aim to systematically study the profile shape of 28SiO v = 0J = 1-0 lines in evolved stars and to discuss the origin of the composite profile structure. Methods: We present observations of 28SiO v = 0J = 1-0 emission in 28 evolved stars, including O-rich, C-rich, and S-type Mira-type variables, OH/IR stars, semiregular long-period variables, red supergiants and one yellow hypergiant. Most objects were observed in several epochs, over a total period of time of one and a half years. The observations were performed with the 40 m radio telescope of the Instituto Geográfico Nacional (IGN) in Yebes, Spain. Results: We find that the composite core plus plateau profiles are systematically present in O-rich Miras, OH/IR stars, and red supergiants. They are also found in one S-type Mira (χ Cyg) and in two semiregular variables (X Her and RS Cnc) that are known to show axial symmetry. In the other objects, the profiles are simpler and similar to those observed in other molecular lines. The composite structure appears in the objects in which SiO emission is thought to come from the very inner circumstellar layers, prior to dust formation. The central spectral feature is found to be systematically composed of a number of narrow spikes, except for X Her and RS Cnc, in which it shows a smooth shape that is very similar to that observed in CO emission. These spikes show a significant (and mostly chaotic) time variation, while in all cases the smooth components remain constant within the uncertainties. The profile shape could come from the superposition

  3. CNC grinding of valve housing piston holes

    SciTech Connect

    Ashbaugh, F.A.

    1991-11-01

    Grinding has traditionally been used for machining operations requiring close dimensional tolerances and better surface finishes than can be obtained from other metal removal techniques. Using a grinding process for the last metal removal operation, the close tolerances and surface finishes can be easily held while eliminating the adverse conditions from the current metal removal processes. Pre-machined test parts were sent to a machine tool supplier to have the critical inside features of a typical piston bore finish machined using an internal CNC grinder equipped with high-frequency spindles. The piston bore and sealing angle were ground using a standard 120-grit silicon carbide wheel. The wafer step was machined using a solid carbide tool designed and built at Allied-Signal Inc., Kansas City Division (KCD). Six consecutive parts were machined for evaluation. The repeatability on all six parts was within print requirements. The inside corner radii was less than 0.002 in. and the surface finish was 8.2 arithmetical average or better as defined by ANSI B46.1, Surface Texture. Machining parts by this grinding process would eliminate bellmouth, chatter, waviness, and traveler polishing operations. It would produce a superior surface finish, small inside radii, and small easily removable burrs. It would also hold tolerances closer and significantly reduce scrap, rework, rejects, and deviations. 1 fig.

  4. Superhumps and Reflares in the WZ Sge-Type Dwarf Nova EG CNC

    NASA Astrophysics Data System (ADS)

    Kato, T.; Nogami, D.; Baba, H.; Masuda, S.; Matsumoto, K.

    EG Cnc is a dwarf nova discovered by Huruhata (1983). No outbursts had been confirmed until 1996 since its last in 1977. The long interval between outbursts and the large (~8 mag) outburst amplitude have strongly suggested that this star belongs to the rare class of WZ Sge-type dwarf novae consisting of only three secure members. Upon VSNET alert on the detection of its second historical outburst by P. Schmeer on 1996 Dec. 30, we undertook extensive CCD photometry using the Osaka Kyoiku University 51 cm telescope and the Ouda 60 cm telescope. Our observation has revealed the existence of two distinct types of superhumps just as were observed in other WZ Sge-type members, WZ Sge and AL Com. The object further showed, for the first time in the history of dwarf novae, repeated ``mini-outbursts" or reflares after its main superoutburst. We discuss from this new observational finding on the relationship between the repeated reflares in EG Cnc and the double superoutburst in AL Com, with a possible implication on the mechanism of similar ``mini-outbursts" observed in the black hole-candidate X-ray transient GRO J0422+32.

  5. Robustness of thermal error compensation model of CNC machine tool

    NASA Astrophysics Data System (ADS)

    Lang, Xianli; Miao, Enming; Gong, Yayun; Niu, Pengcheng; Xu, Zhishang

    2013-01-01

    Thermal error is the major factor in restricting the accuracy of CNC machining. The modeling accuracy is the key of thermal error compensation which can achieve precision machining of CNC machine tool. The traditional thermal error compensation models mostly focus on the fitting accuracy without considering the robustness of the models, it makes the research results into practice is difficult. In this paper, the experiment of model robustness is done in different spinde speeds of leaderway V-450 machine tool. Combining fuzzy clustering and grey relevance selects temperature-sensitive points of thermal error. Using multiple linear regression model (MLR) and distributed lag model (DL) establishes model of the multi-batch experimental data and then gives robustness analysis, demonstrates the difference between fitting precision and prediction precision in engineering application, and provides a reference method to choose thermal error compensation model of CNC machine tool in the practical engineering application.

  6. Calibration of CNC milling machine by direct method

    NASA Astrophysics Data System (ADS)

    Khan, Abdul Wahid; Chen, Wuyi

    2008-12-01

    Calibration refers to the system of quantity value determination of instruments, equipments and test devices according to industrial requirement, based on metrological characteristics. In present research critical parameter which affects the accuracy and product quality of a CNC milling machine, was investigated and quantified by using direct method. These parameters consist of position dependent or position independent parameters, like linear displacement errors, angular errors of linear axes, straightness error of linear axes and squareness error between the axes. Repeatability, lead screw and resolution error of the CNC milling machine were also quantified to provide additional information to the user, because in absence of this additional information a misconception persists causing a major contributor to the inaccuracy and quality of the product. Parameters were measured and quantified by using a laser interferometer and artifacts as working standards under controlled environmental conditions on a manufacturing CNC milling machine. Polynomial regression analyses were carried out for finding the coefficients to predict the errors at each and every desired position which is quite useful for compensation and enhancing the accuracy of a machine system. Machine accuracy detailed chart was also made to assess and assure the accuracy, capability or for accuracy monitoring of the CNC milling machine

  7. Linear positioning laser calibration setup of CNC machine tools

    NASA Astrophysics Data System (ADS)

    Sui, Xiulin; Yang, Congjing

    2002-10-01

    The linear positioning laser calibration setup of CNC machine tools is capable of executing machine tool laser calibraiotn and backlash compensation. Using this setup, hole locations on CNC machien tools will be correct and machien tool geometry will be evaluated and adjusted. Machien tool laser calibration and backlash compensation is a simple and straightforward process. First the setup is to 'find' the stroke limits of the axis. Then the laser head is then brought into correct alignment. Second is to move the machine axis to the other extreme, the laser head is now aligned, using rotation and elevation adjustments. Finally the machine is moved to the start position and final alignment is verified. The stroke of the machine, and the machine compensation interval dictate the amount of data required for each axis. These factors determine the amount of time required for a through compensation of the linear positioning accuracy. The Laser Calibrator System monitors the material temperature and the air density; this takes into consideration machine thermal growth and laser beam frequency. This linear positioning laser calibration setup can be used on CNC machine tools, CNC lathes, horizontal centers and vertical machining centers.

  8. Fidget with Widgets: CNC Activity Introduces the Flatbed Router

    ERIC Educational Resources Information Center

    Tryon, Daniel V.

    2006-01-01

    The computer numerical control (CNC) flatbed router is a powerful tool and a must-have piece of equipment for any technology education program in which students will produce a product--whether it involves Manufacturing, Materials Processing, or any of the vast array of Project Lead the Way courses. This article describes an activity--producing a…

  9. CNC Turning Technician. A Competency-Based Instructional System.

    ERIC Educational Resources Information Center

    Sloan, Kelly; Hilley, Robert

    This competency-based curriculum guide for instructing students in using computer numerically controlled (CNC) turning machines is one of a series of instructional guides for the machinist field developed in Oklahoma. Although developed jointly with Baxter Technologies Corporation and oriented toward the Baxter Vo-Tec 2000 Future Builder CNC…

  10. Generation of gear tooth surfaces by application of CNC machines

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  11. [MaRS Project

    NASA Technical Reports Server (NTRS)

    Aruljothi, Arunvenkatesh

    2016-01-01

    The Space Exploration Division of the Safety and Mission Assurances Directorate is responsible for reducing the risk to Human Space Flight Programs by providing system safety, reliability, and risk analysis. The Risk & Reliability Analysis branch plays a part in this by utilizing Probabilistic Risk Assessment (PRA) and Reliability and Maintainability (R&M) tools to identify possible types of failure and effective solutions. A continuous effort of this branch is MaRS, or Mass and Reliability System, a tool that was the focus of this internship. Future long duration space missions will have to find a balance between the mass and reliability of their spare parts. They will be unable take spares of everything and will have to determine what is most likely to require maintenance and spares. Currently there is no database that combines mass and reliability data of low level space-grade components. MaRS aims to be the first database to do this. The data in MaRS will be based on the hardware flown on the International Space Stations (ISS). The components on the ISS have a long history and are well documented, making them the perfect source. Currently, MaRS is a functioning excel workbook database; the backend is complete and only requires optimization. MaRS has been populated with all the assemblies and their components that are used on the ISS; the failures of these components are updated regularly. This project was a continuation on the efforts of previous intern groups. Once complete, R&M engineers working on future space flight missions will be able to quickly access failure and mass data on assemblies and components, allowing them to make important decisions and tradeoffs.

  12. MOST satellite photometry of stars in the M67 field: eclipsing binaries, blue stragglers and δ Scuti variables

    NASA Astrophysics Data System (ADS)

    Pribulla, Theodor; Rucinski, Slavek; Matthews, Jaymie M.; Kallinger, Thomas; Kuschnig, Rainer; Rowe, Jason F.; Guenther, David B.; Moffat, Anthony F. J.; Sasselov, Dimitar; Walker, Gordon A. H.; Weiss, Werner W.

    2008-11-01

    We present two series of MOST (Microvariability and Oscillations of STars) space-based photometry, covering nearly continuously 10 d in 2004 and 30 d in 2007, of selected variable stars in the upper main sequence of the old open cluster M67. New high-precision light curves were obtained for the blue straggler binary/triple systems AH Cnc, ES Cnc and EV Cnc. The precision and phase coverage of ES Cnc and EV Cnc is by far superior to any previous observations. The light curve of ES Cnc is modelled in detail, assuming two dark photospheric spots and Roche geometry. An analysis of the light curve of AH Cnc indicates a low mass ratio (q ~ 0.13) and a high inclination angle for this system. Two new long-period eclipsing binaries, GSC 814-323 and HD 75638 (non-members of M67) were discovered. We also present ground-based DDO spectroscopy of ES Cnc and of the newly found eclipsing binaries. Especially interesting is HD 75638, a member of a visual binary, which must itself be a triple or a higher multiplicity system. New light curves of two δ Scuti pulsators, EX Cnc and EW Cnc, have been analysed leading to detection of 26 and eight pulsation frequencies of high temporal stability. Based on photometric data from MOST, 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), and on spectroscopic data from the David Dunlap Observatory, University of Toronto. E-mail: pribulla@ta3.sk (TP); rucinski@astro.utoronto.ca (SR)

  13. Planetpol polarimetry of the exoplanet systems 55Cnc and τBoo

    NASA Astrophysics Data System (ADS)

    Lucas, P. W.; Hough, J. H.; Bailey, J. A.; Tamura, M.; Hirst, E.; Harrison, D.

    2009-02-01

    We present very sensitive polarimetry of 55Cnc and τBoo in an attempt to detect the partially polarized reflected light from the planets orbiting these two stars. 55Cnc is orbited by a hot Neptune planet (55Cnce) at 0.038au, a hot Jupiter planet (55Cncb) at 0.11au and at least three more distant planets. The polarization of this system is very stable, showing no sign of the periodic variations that would be expected if a short-period planet were detected. The measured standard deviation of the nightly averaged Stokes Q/I and U/I parameters is 2.2 × 10-6. We derive upper limits on the geometric albedo, AG, and planetary radius using Monte Carlo multiple scattering simulations of a simple model atmosphere. We assume Rayleigh-like scattering and polarization behaviour (scaled by the maximum polarization, pm, at 90°) and pressure insensitive extinction. Atmospheres in which multiple scattering plays only a small role have an almost linear relation between polarization and AG. In this case, the 4σ upper limit is AG < 0.13(R/1.2RJup)-2p-1m for 55Cnce. This is most easily explained if 55Cnce is relatively small, like GJ436b, and therefore not a pure H-He planet. The data do not provide a useful upper limit for 55Cncb. τBoo is orbited by an unusually massive hot Jupiter planet. The data show a standard deviation in the night-to-night average Stokes Q/I and U/I polarization parameters of 5.1 × 10-6. The 4σ upper limit is AG < 0.37(R/1.2RJup)-2p-1m for τBoob, adopting the fairly well established orbital inclination i ~ 40°. This extends the similar upper limits reported previously for this planet to longer wavelengths. The fact that the τBoo data show more scatter, despite the smaller photon noise for this bright star, may be due to the spot activity detected photometrically by the Microvariability & Oscillations of Stars (MOST) satellite. These results contrast markedly with the recent claim of a 3σ detection of a periodic polarization signal from HD189733 with

  14. Absolute and geometric parameters of contact binary GW Cnc

    NASA Astrophysics Data System (ADS)

    Gürol, B.; Gökay, G.; Saral, G.; Gürsoytrak, S. H.; Cerit, S.; Terzioğlu, Z.

    2016-07-01

    We present the results of our investigation on the geometrical and physical parameters of the W UMa type binary system GW Cnc. We analyzed the photometric data obtained in 2010 and 2011 at Ankara University Observatory (AUO) and the spectroscopic data obtained in 2010 at TUBITAK National Observatory (TUG) by using the Wilson-Devinney (2013 revision) code to obtain the absolute and geometrical parameters. We derived masses and radii of the eclipsing system to be M1 = 0.257M⊙ , M2 = 0.971M⊙ , R1 = 0.526R⊙ and R2 = 0.961R⊙ with an orbital inclination i(∘) = 83.38 ± 0.25 and we determined the GW Cnc system to be a W-type W UMa over-contact binary with a mass ratio of q = 3.773 ± 0.007 .

  15. Motion Simulation Analysis of Rail Weld CNC Fine Milling Machine

    NASA Astrophysics Data System (ADS)

    Mao, Huajie; Shu, Min; Li, Chao; Zhang, Baojun

    CNC fine milling machine is a new advanced equipment of rail weld precision machining with high precision, high efficiency, low environmental pollution and other technical advantages. The motion performance of this machine directly affects its machining accuracy and stability, which makes it an important consideration for its design. Based on the design drawings, this article completed 3D modeling of 60mm/kg rail weld CNC fine milling machine by using Solidworks. After that, the geometry was imported into Adams to finish the motion simulation analysis. The displacement, velocity, angular velocity and some other kinematical parameters curves of the main components were obtained in the post-processing and these are the scientific basis for the design and development for this machine.

  16. Constitutive activation of Drosophila CncC transcription factor reduces lipid formation in the fat body.

    PubMed

    Karim, M Rezaul; Taniguchi, Hiroaki; Kobayashi, Akira

    2015-08-01

    Accumulating evidence indicates that the vertebrate stress-response transcription factors Nrf1 and Nrf2 are involved in hepatic lipid metabolism. However, the underlying molecular mechanisms of Nrf1-and Nrf2-mediated lipid metabolism remain unclear. To elucidate the precise roles of Nrfs in this process, we analyzed the physiological role of CncC in lipid metabolism as a Drosophila model for vertebrate Nrf1 and Nrf2. We first examined whether CncC activity is repressed under physiological conditions through a species-conserved NHB1 (N-terminal homology box 1) domain, similar to that observed for Nrf1. Deletion of the NHB1 domain (CncCΔN) led to CncC-mediated rough-eye phenotypes and the induced expression of the CncC target gene gstD1 both in vivo and in vitro. Thus, we decided to explore how CncCΔN overexpression affects the formation of the fat body, which is the major lipid storage organ. Intriguingly, CncCΔN caused a significant reduction in lipid droplet size and triglyceride (TG) levels in the fat body compared to wild type. We found that CncCΔN induced a number of genes related to innate immunity that might have an effect on the regulation of cellular lipid storage. Our study provides new insights into the regulatory mechanism of CncC and its role in lipid homeostasis.

  17. CNC Turning Center Advanced Operations. Computer Numerical Control Operator/Programmer. 444-332.

    ERIC Educational Resources Information Center

    Skowronski, Steven D.; Tatum, Kenneth

    This student guide provides materials for a course designed to introduce the student to the operations and functions of a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 presents course expectations and syllabus, covers safety precautions, and describes the CNC turning center components, CNC…

  18. Reducing maintenance costs in agreement with CNC machine tools reliability

    NASA Astrophysics Data System (ADS)

    Ungureanu, A. L.; Stan, G.; Butunoi, P. A.

    2016-08-01

    Aligning maintenance strategy with reliability is a challenge due to the need to find an optimal balance between them. Because the various methods described in the relevant literature involve laborious calculations or use of software that can be costly, this paper proposes a method that is easier to implement on CNC machine tools. The new method, called the Consequence of Failure Analysis (CFA) is based on technical and economic optimization, aimed at obtaining a level of required performance with minimum investment and maintenance costs.

  19. Intellectual Control System of Processing on CNC Machines

    NASA Astrophysics Data System (ADS)

    Nekrasov, R. Y.; Lasukov, A. A.; Starikov, A. I.; Soloviev, I. V.; Bekareva, O. V.

    2016-04-01

    Scientific and technical progress makes great demands for quality of engineering production. The priority is to ensure metalworking equipment with required dimensional accuracy during the entire period of operation at minimum manufacturing costs. In article considered the problem of increasing of accuracy of processing products on CNC. The authors offers a solution to the problem by providing compensating adjustment in the trajectory of the cutting tool and machining mode. The necessity of creation of mathematical models of processes behavior in an automated technological system operations (OATS). Based on the research, authors have proposed a generalized diagram of diagnosis and input operative correction and approximate mathematical models of individual processes of diagnosis.

  20. Radio emission of cataclysmic variable stars

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  1. Preparation of CNC-dispersed Fe3O4 nanoparticles and their application in conductive paper.

    PubMed

    Liu, Kai; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2015-08-01

    Well-dispersed Fe3O4 nanoparticles (NPs) were synthesized by a co-precipitation method in the presence of cellulose nano-crystals (CNC) as the template. The thus prepared Fe3O4 NPs were then used as a coating agent for the preparation of conductive paper. Fourier transform infrared spectroscopy (FTIR) results revealed that the Fe3O4 NPs were immobilized on the CNC through interactions between the hydroxyl groups of CNC and Fe3O4. Scanning transmission electron microscopy (STEM) images showed that the Fe3O4 NPs prepared in the presence of CNC can be dispersed in the CNC network, while the Fe3O4 NPs prepared in the absence of CNC tended to aggregate in aqueous solutions. The conductivity of the Fe3O4 NPs coated paper can reach to 0.0269 S/m at the coating amount of 14.75 g/m(2) Fe3O4/CNC nanocomposites. Therefore, the thus obtained coated paper can be potentially used as anti-static packaging material in the packaging field.

  2. UVBY Photometry of the Magnetic Chemically Peculiar Stars HR 1297, 36 Aurigae, and HR 2722 and the Nonmagnetic Chemically Peculiar Stars HR 1576 and alpha CANCRI

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.; Brunhouse, Eric F.

    1998-11-01

    Differential Strömgren uvby photometric observations from the Four College Automated Photoelectric Telescope are presented for the magnetic CP stars HR 1297, 36 Aur, and HR 2722 and the nonmagnetic CP stars HR 1576 and alpha Cnc. Both the moderately rotating HR 1576, a mercury-manganese star, and alpha Cnc, a metallic-line star, are nonvariable. For HR 1297 we refined Winzer's period to 1.06457 days. Our period of 14.366 days for 36 Aur is an alias of Winzer's period and is in keeping with the sharp-lined nature of this star. We found a more accurate period of 2.31523 days for the low-amplitude variable HR 2722.

  3. Prepolishing on a CNC platform with bound abrasive contour tools

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

    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 3-5μm 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.

  4. Delta Scuti stars in the Praesepe cluster observed by the MOST satellite

    NASA Astrophysics Data System (ADS)

    Breger, M.; Hareter, M.; Endl, M.; Kuschnig, R.; Weiss, W. W.; Matthews, J. M.; Guenther, D. B.; Moffat, A. F. J.; Rowe, J. F.; Rucinski, S. M.; Sasselov, D.

    2012-02-01

    The Praesepe cluster contains a number of δ Sct and γ Dor pulsators. Asteroseismology of cluster stars is simplified by the common distance, age and stellar abundances. Since asteroseismology requires a large number of known frequencies, the small pulsation amplitudes of these stars require space satellite campaigns. The present study utilizes photometric MOST satellite measurements in order to determine the pulsation frequencies of two evolved (EP Cnc, BT Cnc) and two main-sequence (BS Cnc, HD 73872) δ Sct stars in the Praesepe cluster. The frequency analysis of the 2008 and 2009 data detected up to 34 frequencies per star with most amplitudes in the submillimag range. In BS Cnc, two modes showed strong amplitude variability between 2008 and 2009. The frequencies ranged from 0.76 to 41.7 cd-1. After considering the different evolutionary states and mean stellar densities of these four stars, the differences and large ranges in frequency remain. 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.

  5. Thermal behavior of resistant starches RS 2, RS 3, and RS 4.

    PubMed

    Ratnayake, W S; Jackson, D S

    2008-06-01

    The thermal behaviors of 3 resistant starch types-RS 2, RS 3, and RS 4-were investigated. Samples were heated in excess water to specific temperatures, from 35 to 85 degrees C at 5 degrees C intervals, and freeze-dried. The treated samples were analyzed using SEM, DSC, XRD, and HPSEC to determine the structural changes at granular and molecular levels. Light microscopy was used to determine real-time thermal behavior of the starches. Although the resistant starches did not show significant morphological changes, as revealed by microscopy, they underwent internal structural changes at low temperatures before complete phase transitions occurred. The structural changes were less in RS 2 compared to the other 2 starches studied. The nongranular material of RS 3's crystallinity decreased gradually from 35 to 85 degrees C and showed microscopically visible changes at >80 degrees C. Cross-linking might have prevented RS 4 from becoming completely amorphous within the temperature range (35 to 85 degrees C) tested. The study indicated that the extent of structural changes depended on the treatment temperature and RS type.

  6. 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)

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

    1986-01-01

    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.

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

    PubMed

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

    2014-10-13

    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

  8. Shared and service-oriented CNC machining system for intelligent manufacturing process

    NASA Astrophysics Data System (ADS)

    Li, Yao; Liu, Qiang; Tong, Ronglei; Cui, Xiaohong

    2015-11-01

    To improve efficiency, reduce cost, ensure quality effectively, researchers on CNC machining have focused on virtual machine tool, cloud manufacturing, wireless manufacturing. However, low level of information shared among different systems is a common disadvantage. In this paper, a machining database with data evaluation module is set up to ensure integrity and update. An online monitoring system based on internet of things and multi-sensors "feel" a variety of signal features to "percept" the state in CNC machining process. A high efficiency and green machining parameters optimization system "execute" service-oriented manufacturing, intelligent manufacturing and green manufacturing. The intelligent CNC machining system is applied in production. CNC machining database effectively shares and manages process data among different systems. The prediction accuracy of online monitoring system is up to 98.8% by acquiring acceleration and noise in real time. High efficiency and green machining parameters optimization system optimizes the original processing parameters, and the calculation indicates that optimized processing parameters not only improve production efficiency, but also reduce carbon emissions. The application proves that the shared and service-oriented CNC machining system is reliable and effective. This research presents a shared and service-oriented CNC machining system for intelligent manufacturing process.

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

    PubMed

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

    2014-10-13

    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.

  10. PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity in Latvians, Lithuanians and Taiwanese

    PubMed Central

    Sjakste, Tatjana; Paramonova, Natalia; Wu, Lawrence Shi-Shin; Zemeckiene, Zivile; Sitkauskiene, Brigita; Sakalauskas, Raimundas; Wang, Jiu-Yao; Sjakste, Nikolajs

    2014-01-01

    PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity was investigated in 1438 unrelated subjects from Latvia, Lithuania and Taiwan. In general, polymorphism of each individual locus showed tendencies similar to determined previously in HapMap populations. Main differences concern Taiwanese and include presence of rs2277460 rare allele A not found before in Asians and absence of rs2295827 rare alleles homozygotes TT observed in all other human populations. Observed patterns of SNPs and haplotype diversity were compatible with expectation of neutral model of evolution. Linkage disequilibrium between the rs2295826 and rs2295827 was detected to be complete in Latvians and Lithuanians (D´ = 1; r2 = 1) and slightly disrupted in Taiwanese (D´ = 0.978; r2 = 0.901). Population differentiation (FST statistics) was estimated from pairwise population comparisons of loci variability, five locus haplotypes and PSMA6 and PSMC6 two locus haplotypes. Latvians were significantly different from all Asians at each of 5 SNPs and from Lithuanians at the rs1048990 and PSMC6 loci. Lithuanian and Asian populations exhibited similarities at the PSMC6 loci and were different at the PSMA6 and PSMA3 SNPs. Considering five locus haplotypes all European populations were significantly different from Asian; Lithuanian population was different from both Latvian and CEU. Allele specific patterns of transcription factor binding sites and splicing signals were predicted in silico and addressed to eventual functionality of nucleotide substitutions and their potential to be involved in human genome evolution and geographical adaptation. Current study represents a novel step toward a systematic analysis of the proteasomal gene genetic diversity in human populations. PMID:25606411

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

    NASA Astrophysics Data System (ADS)

    Oja, T.

    2011-02-01

    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.

  12. Systematics for checking geometric errors in CNC lathes

    NASA Astrophysics Data System (ADS)

    Araújo, R. P.; Rolim, T. L.

    2015-10-01

    Non-idealities presented in machine tools compromise directly both the geometry and the dimensions of machined parts, generating distortions in the project. Given the competitive scenario among different companies, it is necessary to have knowledge of the geometric behavior of these machines in order to be able to establish their processing capability, avoiding waste of time and materials as well as satisfying customer requirements. But despite the fact that geometric tests are important and necessary to clarify the use of the machine correctly, therefore preventing future damage, most users do not apply such tests on their machines for lack of knowledge or lack of proper motivation, basically due to two factors: long period of time and high costs of testing. This work proposes a systematics for checking straightness and perpendicularity errors in CNC lathes demanding little time and cost with high metrological reliability, to be used on factory floors of small and medium-size businesses to ensure the quality of its products and make them competitive.

  13. The design of an ultra-precision CNC measuring machine

    SciTech Connect

    Thompson, D.C.

    1989-01-01

    A specialized ultra-precision CNC measuring machine is being developed to provide an inspection capability compatible with existing precision turning machines. The instrument is to be applied to the inspection of the inner and outer surfaces of hemispherical shells and other axisymmetric parts, with diameters of up to 400 mm. The overall accuracy of the machine operating in continuous path contouring mode is to be less than 0.75 micrometre (p-v) per surface, including both instrument and process-related errors. In addition, an accuracy of 1.75 micrometres is required for the inspection of wall thickness on some categories of parts, which in some instances may be distorted by gravity loading. This latter requirement dictates a single setup for the inspection of inner and outer surfaces, and effectively eliminates a standard Coordinate Measuring Machine (CMM) configuration for the new gauge. The new instrument is known as the Certification of Process (COP) Gauge. 9 refs., 5 figs., 2 tabs.

  14. Continuous tone printing in silicone from CNC milled matrices

    NASA Astrophysics Data System (ADS)

    Hoskins, S.; McCallion, P.

    2014-02-01

    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.

  15. Spatial augmented reality on industrial CNC-machines

    NASA Astrophysics Data System (ADS)

    Olwal, Alex; Gustafsson, Jonny; Lindfors, Christoffer

    2008-02-01

    In this work we present how Augmented Reality (AR) can be used to create an intimate integration of process data with the workspace of an industrial CNC (computer numerical control) machine. AR allows us to combine interactive computer graphics with real objects in a physical environment - in this case, the workspace of an industrial lathe. ASTOR is an autostereoscopic optical see-through spatial AR system, which provides real-time 3D visual feedback without the need for user-worn equipment, such as head-mounted displays or sensors for tracking. The use of a transparent holographic optical element, overlaid onto the safety glass, allows the system to simultaneously provide bright imagery and clear visibility of the tool and workpiece. The system makes it possible to enhance visibility of occluded tools as well as to visualize real-time data from the process in the 3D space. The graphics are geometrically registered with the workspace and provide an intuitive representation of the process, amplifying the user's understanding and simplifying machine operation.

  16. ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site

    PubMed Central

    Kashef, Jubin; Alfandari, Dominique

    2015-01-01

    The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell–cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo. PMID:26206614

  17. Synthesis of chemical cross-linked gelatin hydrogel reinforced with cellulose nanocrystals (CNC)

    NASA Astrophysics Data System (ADS)

    Yin, Ooi Shok; Ahmad, Ishak; Amin, Mohd. Cairul Iqbal Mohd

    2014-09-01

    A novel method was performed to obtain hydrogel with superior sensitivity towards changes in pH and temperature by incorporation of CNC into gelatin based hydrogel. Glutaraldehyde was used as cross-linker due to its high chemical reactivity towards NH2 group on gelatin. Different ratio of gelatin / CNC hydrogel was produced in order to study the effects of CNC towards the swelling behaviour of hydrogel at different pH and temperature. Swelling tests were performed at different pH range from pH 3 to pH 11. Temperature swelling tests were performed at 25 °C and 37 °C. The hydrogel showed impressive pH sensitivity and maximum swelling was obtained at pH 3. Higher swelling ratio was observed at higher temperature. SEM micrographs showed that the pore size of hydrogel decreased with increasing CNC content due to formation of more rigid hydrogel structure. The characteristics of the hydrogel to respond to different pH and temperature suggest that gelatin / CNC hydrogel are promising candidates to be developed as drug carrier.

  18. ADAM13 cleavage of cadherin-11 promotes CNC migration independently of the homophilic binding site.

    PubMed

    Abbruzzese, Genevieve; Becker, Sarah F; Kashef, Jubin; Alfandari, Dominique

    2016-07-15

    The cranial neural crest (CNC) is a highly motile population of cells that is responsible for forming the face and jaw in all vertebrates and perturbing their migration can lead to craniofacial birth defects. Cell motility requires a dynamic modification of cell-cell and cell-matrix adhesion. In the CNC, cleavage of the cell adhesion molecule cadherin-11 by ADAM13 is essential for cell migration. This cleavage generates a shed extracellular fragment of cadherin-11 (EC1-3) that possesses pro-migratory activity via an unknown mechanism. Cadherin-11 plays an important role in modulating contact inhibition of locomotion (CIL) in the CNC to regulate directional cell migration. Here, we show that while the integral cadherin-11 requires the homophilic binding site to promote CNC migration in vivo, the EC1-3 fragment does not. In addition, we show that increased ADAM13 activity or expression of the EC1-3 fragment increases CNC invasiveness in vitro and blocks the repulsive CIL response in colliding cells. This activity requires the presence of an intact homophilic binding site on the EC1-3 suggesting that the cleavage fragment may function as a competitive inhibitor of cadherin-11 adhesion in CIL but not to promote cell migration in vivo.

  19. Repurposing mainstream CNC machine tools for laser-based additive manufacturing

    NASA Astrophysics Data System (ADS)

    Jones, Jason B.

    2016-04-01

    The advent of laser technology has been a key enabler for industrial 3D printing, known as Additive Manufacturing (AM). Despite its commercial success and unique technical capabilities, laser-based AM systems are not yet able to produce parts with the same accuracy and surface finish as CNC machining. To enable the geometry and material freedoms afforded by AM, yet achieve the precision and productivity of CNC machining, hybrid combinations of these two processes have started to gain traction. To achieve the benefits of combined processing, laser technology has been integrated into mainstream CNC machines - effectively repurposing them as hybrid manufacturing platforms. This paper reviews how this engineering challenge has prompted beam delivery innovations to allow automated changeover between laser processing and machining, using standard CNC tool changers. Handling laser-processing heads using the tool changer also enables automated change over between different types of laser processing heads, further expanding the breadth of laser processing flexibility in a hybrid CNC. This paper highlights the development, challenges and future impact of hybrid CNCs on laser processing.

  20. Observations of active chromosphere stars

    NASA Technical Reports Server (NTRS)

    Africano, J. L.; Klimke, A.; Stencel, R. E.; Noah, P. V.; Bopp, B. W.

    1983-01-01

    It is pointed out that spectroscopic signatures of stellar chromospheric activity are readily observable. The present study is concerned with new photometric and spectroscopic observations of active-chromosphere RS CVn, BY Dra, and FK Com stars. Attention is given to the first results of a synoptic monitoring program of many active chromosphere stars. During the time from 1980 to 1982, photometric and spectroscopic observations of 10 known or suspected active-chromosphere objects were made. The results regarding the individual stars are discussed. Seven stars observed with the International Ultraviolet Explorer (IUE) are all spectroscopic binaries.

  1. The in-situ 3D measurement system combined with CNC machine tools

    NASA Astrophysics Data System (ADS)

    Zhao, Huijie; Jiang, Hongzhi; Li, Xudong; Sui, Shaochun; Tang, Limin; Liang, Xiaoyue; Diao, Xiaochun; Dai, Jiliang

    2013-06-01

    With the development of manufacturing industry, the in-situ 3D measurement for the machining workpieces in CNC machine tools is regarded as the new trend of efficient measurement. We introduce a 3D measurement system based on the stereovision and phase-shifting method combined with CNC machine tools, which can measure 3D profile of the machining workpieces between the key machining processes. The measurement system utilizes the method of high dynamic range fringe acquisition to solve the problem of saturation induced by specular lights reflected from shiny surfaces such as aluminum alloy workpiece or titanium alloy workpiece. We measured two workpieces of aluminum alloy on the CNC machine tools to demonstrate the effectiveness of the developed measurement system.

  2. Physical Parameters of the Overcontact Binary AH Cnc in the Old Open Cluster M 67

    NASA Astrophysics Data System (ADS)

    Yakut, K.; Aerts, C.

    2006-04-01

    We present a photometric study of the overcontact binary AH Cnc. The CCD observations were done with the Russian-Turkish 1.5 m telescope and the light-curve was solved with the Wilson-Devinney code. The physical parameters of the components have been deduced as M1 = 1.22 Msun, M2 = 0.20 Msun, R1 = 1.37 Rsun, R2 = 0.66 Rsun, L1 = 2.65 Lsun and L2 = 0.63 Lsun from the obtained orbital parameters and the distance modules of M 67. AH Cnc has been compared with similar systems in the Hertzsprung-Russell diagram.

  3. The FK Comae stars

    NASA Technical Reports Server (NTRS)

    Bopp, B. W.; Stencel, R. E.

    1981-01-01

    The paper presents IUE observations of three very rapidly rotating G-K giants (v sin i = 100 km/s). The UV spectra show strong chromospheric and transition region emission lines similar to (and in excess of) the RS CVn binaries. These stars show no evidence for radial velocity variations in excess of plus or minus 3 to plus or minus 20 km/s, arguing against duplicity. As a class, they lend support to the rotation-activity hypothesis. Coalesced W UMa binaries, rather than single stars, are the possible progenitors for these FK Com variables.

  4. H. cap alpha. in RS CVn binaries

    SciTech Connect

    Bopp, B.W.; Talcott, J.C.

    1980-01-01

    The 1976--78 results of a spectroscopic program to monitor H..cap alpha.. in several RS CVn-type binaries are reported. For six objects well observed over orbital phase, four (HR 4665, HR 5110, sigma Gem, Z Her) show H..cap alpha.. as an absorption feature having a constant ( +- 15%) equivalent width (EW). AR Lac exhibits an absorption profile also, but the EW varies by a factor of three due to partial filling by emission. This variation is sporadic and not phase dependent. The H..cap alpha.. feature in HK Lac shows the most extreme variation: normally seen as an absorption feature with variable EW, it has been observed as a pure emission feature on three spectrograms, showing a blueshift with respect to the photosphere of approx.50--100 km sec/sup -1/. On a single occasion HK Lac showed double H..cap alpha.. emission with a separation of the peaks of approx.300 km sec/sup -1/. These high velocity features are interpreted in terms of prominence-like structure in the atmosphere of the active star.

  5. HM Sagittae - Symbiotic cousin of the RS CVn stars

    NASA Technical Reports Server (NTRS)

    Blair, W. P.; Stencel, R. E.; Feibelman, W. A.; Shaviv, G.

    1981-01-01

    In the brief time since its brightening in 1975, the optical spectrum of HM Sagittae has shown considerable variation in both its general characteristics and relative line intensity ratios. The observations place HM Sagittae in a small class of objects which are thought to be proto-planetary nebulae, of which V 1016 Cygni is the prototype. Attention is given to derived density and temperature, helium abundance and nebular mass, and an evolutionary scenario. The considered observations show a decrease in the intensity of the continuum and a continuation of the trend toward higher excitation in the spectrum of HM Sagittae. Parallels are seen in the development of this object and V 1016 Cygni, with the implication that the trend toward higher excitation is expected to continue.

  6. SEAC4RS Aerosol Radiative Effects and Heating Rates

    NASA Astrophysics Data System (ADS)

    Cochrane, S.; Schmidt, S.; Redemann, J.; Hair, J. W.; Ferrare, R. A.; Segal-Rosenhaimer, M.; LeBlanc, S. E.

    2015-12-01

    We will present (a) aerosol optical properties, (b) aerosol radiative forcing, (c) aerosol and gas absorption and heating rates, and (d) spectral surface albedo for cases from August 19th and 26th of the SEAC4RS mission. This analysis is based on irradiance data from the Solar Spectral Flux Radiometer (SSFR), spectral aerosol optical depth from the Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR), and extinction profiles from the DIAL/High Spectral Resolution Lidar (HSRL). We derive spectrally resolved values of single scattering albedo, asymmetry parameter, and surface albedo from the data, and determine profiles of absorption and heating rate segregated by absorber (aerosol and gas).

  7. Learning Control: Sense-Making, CNC Machines, and Changes in Vocational Training for Industrial Work

    ERIC Educational Resources Information Center

    Berner, Boel

    2009-01-01

    The paper explores how novices in school-based vocational training make sense of computerized numerical control (CNC) machines. Based on two ethnographic studies in Swedish schools, one from the early 1980s and one from 2006, it analyses change and continuity in the cognitive, social, and emotional processes of learning how to become a machine…

  8. Development of a QFD-based expert system for CNC turning centre selection

    NASA Astrophysics Data System (ADS)

    Prasad, Kanika; Chakraborty, Shankar

    2015-10-01

    Computer numerical control (CNC) machine tools are automated devices capable of generating complicated and intricate product shapes in shorter time. Selection of the best CNC machine tool is a critical, complex and time-consuming task due to availability of a wide range of alternatives and conflicting nature of several evaluation criteria. Although, the past researchers had attempted to select the appropriate machining centres using different knowledge-based systems, mathematical models and multi-criteria decision-making methods, none of those approaches has given due importance to the voice of customers. The aforesaid limitation can be overcome using quality function deployment (QFD) technique, which is a systematic approach for integrating customers' needs and designing the product to meet those needs first time and every time. In this paper, the adopted QFD-based methodology helps in selecting CNC turning centres for a manufacturing organization, providing due importance to the voice of customers to meet their requirements. An expert system based on QFD technique is developed in Visual BASIC 6.0 to automate the CNC turning centre selection procedure for different production plans. Three illustrative examples are demonstrated to explain the real-time applicability of the developed expert system.

  9. Technical and Symbolic Knowledge in CNC Machining: A Study of Technical Workers of Different Backgrounds.

    ERIC Educational Resources Information Center

    Martin, Laura M. W.; Beach, King

    Performances of 45 individuals with varying degrees of formal and informal training in machining and programming were compared on tasks designed to tap intellectual changes that may occur with the introduction of computer numerical control (CNC). Participants--30 machinists, 8 machine operators, and 7 engineers--were asked background questions and…

  10. CNC Turning Center Operations and Prove Out. Computer Numerical Control Operator/Programmer. 444-334.

    ERIC Educational Resources Information Center

    Skowronski, Steven D.

    This student guide provides materials for a course designed to instruct the student in the recommended procedures used when setting up tooling and verifying part programs for a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 discusses course content and reviews and demonstrates set-up procedures…

  11. Basic CNC Operation. Training Workbook [and] Assessment and Training Guide [and] Hands-on Assessment.

    ERIC Educational Resources Information Center

    Anoka-Hennepin Technical Coll., Minneapolis, MN.

    This workbook is intended for students taking a course in basic computer numerical control (CNC) operation that was developed during a project to retrain defense industry workers at risk of job loss or dislocation because of conversion of the defense industry. The workbook contains daily training guides for each of the course's 13 sessions. Among…

  12. 78 FR 50135 - CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order... current and accurate information concerning the securities of South American Minerals, Inc. because it...

  13. In-situ polymerized cellulose nanocrystals (CNC)-poly(l-lactide) (PLLA) nanomaterials and applications in nanocomposite processing.

    PubMed

    Miao, Chuanwei; Hamad, Wadood Y

    2016-11-20

    CNC-PLLA nanomaterials were synthesized via in-situ ring-opening polymerization of l-lactide in the presence of CNC, resulting in hydrophobic, homogeneous mixture of PLLA-grafted-CNC and free PLLA homopolymer. The free PLLA serves two useful functions: as barrier to further prevent PLLA-g-CNC from forming aggregates, and in creating improved interfacial properties when these nanomaterials are blended with other polymers, hence enhancing their performance. CNC-PLLA nanomaterials can be used for medical or engineering applications as-they-are or by compounding with suitable biopolymers using versatile techniques, such as solution casting, co-extrusion or injection molding, to form hybrid nanocomposites of tunable mechanical properties. When compounded with commercial-grade PLA, the resulting CNC-PLA nanocomposites appear transparent and have tailored (dynamic and static) mechanical and barrier properties, approaching those of poly(ethylene terephthalate), PET. The effect of reaction conditions on the properties of CNC-PLLA nanomaterials have been carefully studied and detailed throughout the paper. PMID:27561528

  14. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    NASA Astrophysics Data System (ADS)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat; Amin, Mohd. Cairul Iqbal Mohd

    2014-09-01

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  15. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    SciTech Connect

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat; Amin, Mohd. Cairul Iqbal Mohd

    2014-09-03

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  16. Documentation for the machine-readable version of the Catalogue of Nearby Stars, edition 1969

    NASA Technical Reports Server (NTRS)

    Warren, W. H., Jr.

    1982-01-01

    The Catalogue of Nearby Stars, Edition 1969 (Gliese 1969) contains a number of modifications and additions to the 1957 catalog. It should be mentioned that the 1969 edition lists: (1) all 915 stars of the first edition, even though newer parallaxes place some of the stars below the catalog limit; (2) almost all known stars having trigonometric parallaxes or = 0.045 deg, although in some cases the mean values of trigonometric and spectral or photometric parallaxes are or = 0.045 deg. Pleiades stars and the carbon star X Cnc have been omitted; and (3) all stars with mean (resulting) parallaxes or = 0.045 deg. The resulting catalog contains 1529 single stars and systems with a total of 1890 components (not including spectroscopic and astrometric companions). The machine-readable version of the catalog is described. It is intended to enable users to read and process the data without problems or guesswork.

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

    PubMed

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

    2014-08-01

    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.

  18. A Three Dimensional Picture of RS CVN Stellar Atmospheres

    NASA Astrophysics Data System (ADS)

    Linsky, Jeffrey L.

    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

  19. RS/1 in the Clinical Environment

    PubMed Central

    Kush, Thomas

    1980-01-01

    This paper describes the design of RS/1,™ the Research System, and its use in clinical patient studies. RS/1 is an interactive computer software system developed by the Medical Systems Group at BBN. Investigators and technicians who have never before used computers can learn RS/1 with a few hours of training. It uses familiar and intuitive concepts for data handling and data analysis, such as the “automated notebook” format of data storage, the direct use of graphs in curve-fitting, and a simple command language. Its versatility has made RS/1 useful in clinical research contexts, especially for studies involving patient care data.

  20. Polymorphisms in TP53 (rs1042522), p16 (rs11515 and rs3088440) and NQO1 (rs1800566) genes in Thai cervical cancer patients with HPV 16 infection.

    PubMed

    Chansaenroj, Jira; Theamboonlers, Apiradee; Junyangdikul, Pairoj; Swangvaree, Sukumarn; Karalak, Anant; Chinchai, Teeraporn; Poovorawan, Yong

    2013-01-01

    The risk of cervical cancer development in women infected with HPV varies in relation to the individual host's genetic makeup. Many studies on polymorphisms as genetic factors have been aimed at analyzing associations with cervical cancer. In this study, single nucleotide polymorphisms (SNPs) in 3 genes were investigated in relation to cervical cancer progression in HPV16 infected women with lesions. Two thousand cervical specimens were typed by PCR sequencing methods for TP53 (rs1042522), p16 (rs11515 and rs3088440) and NQO1 (rs1800566). Ninety two HPV16 positive cases and thirty two normal cases were randomly selected. Analysis of TP53 (rs1042522) showed a significantly higher frequency in cancer samples (OR=1.22, 95%CI=1.004-1.481, p-value=0.016) while differences in frequency were not significant within each group (p-value=0.070). The genotype distributions of p16 (rs11515 and rs3088440) and NQO1 (rs1800566) did not show any significantly higher frequency in cancer samples (p-value=0.106, 0.675 and 0.132, respectively) or within each group (p-value=0.347, 0.939 and 0.111, respectively). The results indicated that the polymorphism in TP53 (rs1042522) might be associated with risk of cervical cancer development in HPV16 infected women. Further studies of possible mechanisms of influence on cervical cancer development would be useful to manage HPV infected patients. PMID:23534750

  1. Preparation of the CNC/Ag/beeswax composites for enhancing antibacterial and water resistance properties of paper.

    PubMed

    Liu, Kai; Liang, Hunan; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2016-05-20

    An effective method of preparing composites containing inorganic (Ag) and organic (beeswax) particles was established in this study. Ag nanoparticles were first immobilized on the cellulose nanocrystals (CNC) during the reduction of AgNO3 in the presence of CNC, then mixed with beeswax by high speed stirring. Scanning transmission electron microscopy (STEM) images indicated that Ag and beeswax particles were uniformly dispersed and stable in the network structure formed by CNC. Upon coating on a paper surface, a layer of beeswax film was evident based on scanning electron microscopy (SEM) images. The dynamic contact angle and antibacterial activity tests indicated that the contact angle of coated paper reached 113.06° and the growth inhibition of Escherichia coli increased to 99.96%, respectively, at a coating amount of 21.53 g/m(2). When applied onto paper surface by coating, the CNC/Ag/beeswax composites can impact paper with antibacterial property and improved water resistance.

  2. Basic leucine zipper protein Cnc-C is a substrate and transcriptional regulator of the Drosophila 26S proteasome.

    PubMed

    Grimberg, Kristian Björk; Beskow, Anne; Lundin, Daniel; Davis, Monica M; Young, Patrick

    2011-02-01

    While the 26S proteasome is a key proteolytic complex, little is known about how proteasome levels are maintained in higher eukaryotic cells. Here we describe an RNA interference (RNAi) screen of Drosophila melanogaster that was used to identify transcription factors that may play a role in maintaining levels of the 26S proteasome. We used an RNAi library against 993 Drosophila transcription factor genes to identify genes whose suppression in Schneider 2 cells stabilized a ubiquitin-green fluorescent protein reporter protein. This screen identified Cnc (cap 'n' collar [CNC]; basic region leucine zipper) as a candidate transcriptional regulator of proteasome component expression. In fact, 20S proteasome activity was reduced in cells depleted of cnc. Immunoblot assays against proteasome components revealed a general decline in both 19S regulatory complex and 20S proteasome subunits after RNAi depletion of this transcription factor. Transcript-specific silencing revealed that the longest of the seven transcripts for the cnc gene, cnc-C, was needed for proteasome and p97 ATPase production. Quantitative reverse transcription-PCR confirmed the role of Cnc-C in activation of transcription of genes encoding proteasome components. Expression of a V5-His-tagged form of Cnc-C revealed that the transcription factor is itself a proteasome substrate that is stabilized when the proteasome is inhibited. We propose that this single cnc gene in Drosophila resembles the ancestral gene family of mammalian nuclear factor erythroid-derived 2-related transcription factors, which are essential in regulating oxidative stress and proteolysis.

  3. Basic Leucine Zipper Protein Cnc-C Is a Substrate and Transcriptional Regulator of the Drosophila 26S Proteasome▿ †

    PubMed Central

    Grimberg, Kristian Björk; Beskow, Anne; Lundin, Daniel; Davis, Monica M.; Young, Patrick

    2011-01-01

    While the 26S proteasome is a key proteolytic complex, little is known about how proteasome levels are maintained in higher eukaryotic cells. Here we describe an RNA interference (RNAi) screen of Drosophila melanogaster that was used to identify transcription factors that may play a role in maintaining levels of the 26S proteasome. We used an RNAi library against 993 Drosophila transcription factor genes to identify genes whose suppression in Schneider 2 cells stabilized a ubiquitin-green fluorescent protein reporter protein. This screen identified Cnc (cap 'n’ collar [CNC]; basic region leucine zipper) as a candidate transcriptional regulator of proteasome component expression. In fact, 20S proteasome activity was reduced in cells depleted of cnc. Immunoblot assays against proteasome components revealed a general decline in both 19S regulatory complex and 20S proteasome subunits after RNAi depletion of this transcription factor. Transcript-specific silencing revealed that the longest of the seven transcripts for the cnc gene, cnc-C, was needed for proteasome and p97 ATPase production. Quantitative reverse transcription-PCR confirmed the role of Cnc-C in activation of transcription of genes encoding proteasome components. Expression of a V5-His-tagged form of Cnc-C revealed that the transcription factor is itself a proteasome substrate that is stabilized when the proteasome is inhibited. We propose that this single cnc gene in Drosophila resembles the ancestral gene family of mammalian nuclear factor erythroid-derived 2-related transcription factors, which are essential in regulating oxidative stress and proteolysis. PMID:21149573

  4. The resonance line of B II in IUE spectra of chemically peculiar stars

    NASA Technical Reports Server (NTRS)

    Leckrone, D. S.

    1981-01-01

    A description is presented of high-dispersion spectroscopic observations of eight chemically peculiar stars including Kappa Cnc and Mu Lep, and of one normal comparison star, Nu Cap, in the vicinity of 1362 A. The reported data were obtained with the International Ultraviolet Explorer during the first 15 months of its operation. The initial reduction of the data, which were originally described in a qualitative summary by Leckrone (1980), was affected by a serious error in the calibration of the instrument's intensity transfer function. This error has been corrected in the currently presented data. The results of spectrum syntheses of the 1362 A feature are also described for several of the stars.

  5. PLLA-grafted cellulose nanocrystals: Role of the CNC content and grafting on the PLA bionanocomposite film properties.

    PubMed

    Lizundia, Erlantz; Fortunati, Elena; Dominici, Franco; Vilas, José Luis; León, Luis Manuel; Armentano, Ilaria; Torre, Luigi; Kenny, Josè M

    2016-05-20

    Cellulose nanocrystals (CNC), extracted from microcrystalline cellulose by acid hydrolysis, were grafted by ring opening polymerization of L-Lactide initiated from the hydroxyl groups available at their surface and two different CNC:L-lactide ratios (20:80 and 5:95) were obtained. The resulting CNC-g-PLLA nanohybrids were incorporated in poly(lactic acid) (PLA) matrix by an optimized extrusion process at two different content (1 wt.% and 3 wt.%) and obtained bionanocomposite films were characterized by thermal, mechanical, optical and morphological properties. Thermal analysis showed CNC grafted with the higher ratio of lactide play a significant role as a nucleating agent. Moreover, they contribute to a significant increase in the crystallization rate of PLA, and the best efficiency was revealed with 3 wt.% of CNC-g-PLLA. This effect was confirmed by the increased in Young's modulus, suggesting the CNC graft ratio and content contribute significantly to the good dispersion in the matrix, positively affecting the final bionanocomposite properties. PMID:26917380

  6. The Prompt Design of CNC Grinder Based on Flexible Product Platform

    NASA Astrophysics Data System (ADS)

    Gan, Dequan; Jiang, Ping; Zhang, Huangao; Chen, Zishun

    In mass customization the product platform is the power method to improve the reused ability of existing design resource. But to the high degree modularity product, the module limits the commonality of product platform. The flexible product platform solves the conflict of modularity’s variety and commonality. The platform parameters denote the common properties of product platform and different values of those parameters realize the flexible of product platform. Then the parameter-independent modules can be combined into a physical product platform and extend to satisfy much more market segments. The flexible product platform of CNC grinder improves the reutilization and guides the designer promptly to develop the individual CNC grinder for personal customer needs.

  7. Research on efficient and stable milling using CNC small size tool

    NASA Astrophysics Data System (ADS)

    Luo, Yongxin; Zhao, Beichen; Long, Hua; Yu, Nanlin

    2011-05-01

    In order to mill efficiently and stably using small size tool on computer numerical control machine(CNC machine), the paper establishes dual-objective function on the basis of the minimum tool wear and the largest cutting efficiency. Meanwhile, the influence of diameter and length of tool suspended on stability is considered under the guidance of chatter stability analysis relationship. Research results show that, Pareto solution set which has two factors into account conflicting can be obtained by Genetic Algorithms, combined Pareto solution set with the frequency response function (FRF) chatter stability diagram, Pareto solutions of the smaller range of options, the milling parameters which meet the requirements of efficient and stable milling of CNC machine tools can be optimized conveniently and accurately. When the tool suspended length increases, the system stiffness decreases and the chatter stability domain graphic drops down, Stability region narrows.

  8. Comparison between predicted and actual accuracies for an Ultra-Precision CNC measuring machine

    SciTech Connect

    Thompson, D.C.; Fix, B.L.

    1995-05-30

    At the 1989 CIRP annual meeting, we reported on the design of a specialized, ultra-precision CNC measuring machine, and on the error budget that was developed to guide the design process. In our paper we proposed a combinatorial rule for merging estimated and/or calculated values for all known sources of error, to yield a single overall predicted accuracy for the machine. In this paper we compare our original predictions with measured performance of the completed instrument.

  9. RS CV sub n binary systems

    NASA Technical Reports Server (NTRS)

    Linsky, J. L.

    1984-01-01

    An attempt is made to place in context the vast amount of data obtained as a result of X-ray, ultraviolet, optical, and microwave observations of RS CVn and similar spectroscopic binary systems. Emphasis is on the RS CVn systems and their long period analogs. The following questions are considered: (1) are the original defining characteristics still valid and still adequate? (2) what is the evidence for discrete active regions? (3) have any meaningful physical properties for the atmospheres of RS CVn systems been derived? (4) what do the flare observations tell about magnetic fields in RS CVn systems? (5) is there evidence for systematic trends in RS CVn systems with spectral type?

  10. Star Light, Star Bright.

    ERIC Educational Resources Information Center

    Iadevaia, David G.

    1984-01-01

    Presents a technique for obtaining a rough measure of the brightness among different stars. Materials needed include a standard 35-mm camera, a plastic ruler, and a photo enlarger. Although a telescope can be used, it is not essential. (JN)

  11. Variability in the super-Earth 55 Cnc e

    NASA Astrophysics Data System (ADS)

    Demory, Brice-Olivier; Gillon, Michael; Madhusudhan, Nikku; Queloz, Didier

    2016-01-01

    Considerable progress has been made in recent years in observations of atmospheric signatures of giant exoplanets, but processes in rocky exoplanets remain largely unknown due to major challenges in observing small planets. Numerous efforts to observe spectra of super-Earths, exoplanets with masses of 1-10 Earth masses, have thus far revealed only featureless spectra. In this paper, we report a 4σ detection of variability in the dayside thermal emission from the transiting super-Earth 55 Cancri e. Dedicated space-based monitoring of the planet in the mid-infrared over eight eclipses revealed the thermal emission from its dayside atmosphere varying by a factor of 3.7 between 2012 and 2013. The amplitude and trend of the variability are not explained by potential influence of star spots or by local thermal or compositional changes in the atmosphere over the short span of the observations. The possibility of large-scale surface activity due to strong tidal interactions possibly similar to Io, or the presence of circumstellar/circumplanetary material appear plausible and motivate future long-term monitoring of the planet.

  12. Ares V and RS-68B

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    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.

  13. Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains Site

    DOE PAGESBeta

    Jensen, M. P.; Holdridge, D.; Survo, P.; Lehtinen, R.; Baxter, S.; Toto, T.; Johnson, K. L.

    2015-11-02

    In the fall of 2013, the Vaisala RS41-SG (4th generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity and pressure. Thus, in order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Facility site in north Central Oklahoma USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results suggest that the RS92 and RS41 measurements generally agree within manufacturermore » specified tolerances with notable exceptions when exiting liquid cloud layers where the "wet bulbing" effect is mitigated in the RS41 observations. The RS41 measurements also appear to show a smaller impact from solar heating. These results suggest that the RS41 does provide important improvements, particularly in cloudy conditions, but under most observational conditions the RS41 and RS92 measurements agree within the manufacturer specified limits and so a switch to RS41 radiosondes will have little impact on long-term observational records.« less

  14. Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains site

    NASA Astrophysics Data System (ADS)

    Jensen, Michael P.; Holdridge, Donna J.; Survo, Petteri; Lehtinen, Raisa; Baxter, Shannon; Toto, Tami; Johnson, Karen L.

    2016-07-01

    In the fall of 2013, the Vaisala RS41 (fourth generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity, and pressure. In order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility site in north-central Oklahoma, USA. During 3-8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results show that for most of the observed conditions the RS92 and RS41 measurements agree much better than the manufacturer-specified combined uncertainties with notable exceptions when exiting liquid cloud layers where the "wet-bulbing" effect appears to be mitigated for several cases in the RS41 observations. The RS41 measurements of temperature and humidity, with applied correction algorithms, also appear to show less sensitivity to solar heating. These results suggest that the RS41 does provide important improvements, particularly in cloudy conditions. For many science applications - such as atmospheric process studies, retrieval development, and weather forecasting and climate modeling - the differences between the RS92 and RS41 measurements should have little impact. However, for long-term trend analysis and other climate applications, additional characterization of the RS41 measurements and their relation to the long-term observational records will be required.

  15. Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains Site

    SciTech Connect

    Jensen, M. P.; Holdridge, D.; Survo, P.; Lehtinen, R.; Baxter, S.; Toto, T.; Johnson, K. L.

    2015-11-02

    In the fall of 2013, the Vaisala RS41-SG (4th generation) radiosonde was introduced as a replacement for the RS92-SGP radiosonde with improvements in measurement accuracy of profiles of atmospheric temperature, humidity and pressure. Thus, in order to help characterize these improvements, an intercomparison campaign was undertaken at the US Department of Energy's Atmospheric Radiation Measurement (ARM) Facility site in north Central Oklahoma USA. During 3–8 June 2014, a total of 20 twin-radiosonde flights were performed in a variety of atmospheric conditions representing typical midlatitude continental summertime conditions. The results suggest that the RS92 and RS41 measurements generally agree within manufacturer specified tolerances with notable exceptions when exiting liquid cloud layers where the "wet bulbing" effect is mitigated in the RS41 observations. The RS41 measurements also appear to show a smaller impact from solar heating. These results suggest that the RS41 does provide important improvements, particularly in cloudy conditions, but under most observational conditions the RS41 and RS92 measurements agree within the manufacturer specified limits and so a switch to RS41 radiosondes will have little impact on long-term observational records.

  16. Extremely active long-period RS CVn binary HD 12545

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  17. A SUPER-EARTH TRANSITING A NAKED-EYE STAR

    SciTech Connect

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

    2011-08-10

    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.

  18. A Super-Earth Transiting a Naked-eye Star

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    SciTech Connect

    Bubar, Eric J.; Mamajek, Eric E.; Jensen, Eric L. N.; Walter, Frederick M.

    2011-04-15

    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.

  20. IUE spectra of a flare in HR 5110: A flaring RS CVn or Algol system?

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Ultraviolet spectra of the RS CVn type binary system HR 5110 were obtained with IUE on May 31, 1979 during a period of intense radio flaring of this star. High temperature transition region lines are present, but are not enhanced above observed quiescent strengths. The similarities of HR 5110 to the Algol system, As Eri, suggest that the 1979 May to June flare may involve mass exchange rather than annihilation of coronal magnetic fields.

  1. Optical and X-ray studies of chromospherically active stars: FR Cancri, HD 95559 and LO Pegasi

    NASA Technical Reports Server (NTRS)

    Pandey, J. C.; Singh, K. P.; Drake, S. A.; Sagar, R.

    2005-01-01

    We present a multiwavelength study of three chromospherically active stars, namely FR Cnc (= BD +16 degrees 1753), HD 95559 and LO Peg (=BD +22 degrees 4409), including newly obtained optical photometry, (for FR Cnc) low-resolution optical spectroscopy, as well as archival IR and X-ray observations. The BVR photometry carried out during the years 2001 - 2004 has found significant photometric variability to be present in all three stars. For FR Cnc, a photometric period 0.826685 +/- 0.000034 d has been established. The strong variation in the phase and amplitude of the FR Cnc light curves when folded on this period implies the presence of evolving and migrating spots or spot groups on its surface. Two independent spots with migration periods of 0.97 and 0.93 years respectively are inferred. The photometry of HD 95559 suggests the formation of a spot (group) during the interval of our observations. We infer the existence of two independent spots or groups in the photosphere of LO Peg, one of which has a migration period of 1.12 years. The optical spectroscopy of FR Cnc carried out during 2002-2003, reveals the presence of strong and variable Ca I1 H and K, H(sub beta) and H(sub alpha) emission features indicative of high level of chromospheric activity. The value of 5.3 for the ratio of the excess emission in H(sub alpha) to H(sub beta), EH(sub alpha)/EH(sub beta), suggests that the chromospheric emission may arise from an extended off-limb region. We have searched for the presence of color excesses in the near-IR JHK bands of these stars using 2MASS data, but none of them appear to have any significant color excess. We have also analyzed archival X-ray observations of HD 95559 and LO Peg carried out by with the ROSAT observatory. The best fit models to their X-ray spectra imply the presence of two coronal plasma components of differing temperatures and with sub-solar metal abundances. The inferred emission measures and temperatures of these systems are similar to

  2. Finger milling-cutter CNC generating hypoid pinion tooth surfaces based on modified-roll method and machining simulation

    NASA Astrophysics Data System (ADS)

    Li, Genggeng; Deng, Xiaozhong; Wei, Bingyang; Lei, Baozhen

    2011-05-01

    The two coordinate systems of cradle-type hypoid generator and free-form CNC machine tool by application disc milling-cutter to generate hypoid pinion tooth surfaces based on the modified-roll method were set up, respectively, and transformation principle and method for machine-tool settings between the two coordinate systems was studied. It was presented that finger milling-cutter was mounted on imagined disc milling-cutter and its motion was controlled directly by CNC shafts to replace disc milling-cutter blades effective cutting motion. Finger milling-cutter generation accomplished by ordered circular interpolation was determined, and interpolation center, starting and ending were worked out. Finally, a hypoid pinion was virtually machined by using CNC machining simulation software VERICUT.

  3. Finger milling-cutter CNC generating hypoid pinion tooth surfaces based on modified-roll method and machining simulation

    NASA Astrophysics Data System (ADS)

    Li, Genggeng; Deng, Xiaozhong; Wei, Bingyang; Lei, Baozhen

    2010-12-01

    The two coordinate systems of cradle-type hypoid generator and free-form CNC machine tool by application disc milling-cutter to generate hypoid pinion tooth surfaces based on the modified-roll method were set up, respectively, and transformation principle and method for machine-tool settings between the two coordinate systems was studied. It was presented that finger milling-cutter was mounted on imagined disc milling-cutter and its motion was controlled directly by CNC shafts to replace disc milling-cutter blades effective cutting motion. Finger milling-cutter generation accomplished by ordered circular interpolation was determined, and interpolation center, starting and ending were worked out. Finally, a hypoid pinion was virtually machined by using CNC machining simulation software VERICUT.

  4. Accurate identification and compensation of geometric errors of 5-axis CNC machine tools using double ball bar

    NASA Astrophysics Data System (ADS)

    Lasemi, Ali; Xue, Deyi; Gu, Peihua

    2016-05-01

    Five-axis CNC machine tools are widely used in manufacturing of parts with free-form surfaces. Geometric errors of machine tools have significant effects on the quality of manufactured parts. This research focuses on development of a new method to accurately identify geometric errors of 5-axis CNC machines, especially the errors due to rotary axes, using the magnetic double ball bar. A theoretical model for identification of geometric errors is provided. In this model, both position-independent errors and position-dependent errors are considered as the error sources. This model is simplified by identification and removal of the correlated and insignificant error sources of the machine. Insignificant error sources are identified using the sensitivity analysis technique. Simulation results reveal that the simplified error identification model can result in more accurate estimations of the error parameters. Experiments on a 5-axis CNC machine tool also demonstrate significant reduction in the volumetric error after error compensation.

  5. Design and accuracy analysis of a metamorphic CNC flame cutting machine for ship manufacturing

    NASA Astrophysics Data System (ADS)

    Hu, Shenghai; Zhang, Manhui; Zhang, Baoping; Chen, Xi; Yu, Wei

    2016-05-01

    The current research of processing large size fabrication holes on complex spatial curved surface mainly focuses on the CNC flame cutting machines design for ship hull of ship manufacturing. However, the existing machines cannot meet the continuous cutting requirements with variable pass conditions through their fixed configuration, and cannot realize high-precision processing as the accuracy theory is not studied adequately. This paper deals with structure design and accuracy prediction technology of novel machine tools for solving the problem of continuous and high-precision cutting. The needed variable trajectory and variable pose kinematic characteristics of non-contact cutting tool are figured out and a metamorphic CNC flame cutting machine designed through metamorphic principle is presented. To analyze kinematic accuracy of the machine, models of joint clearances, manufacturing tolerances and errors in the input variables and error models considering the combined effects are derived based on screw theory after establishing ideal kinematic models. Numerical simulations, processing experiment and trajectory tracking experiment are conducted relative to an eccentric hole with bevels on cylindrical surface respectively. The results of cutting pass contour and kinematic error interval which the position error is from-0.975 mm to +0.628 mm and orientation error is from-0.01 rad to +0.01 rad indicate that the developed machine can complete cutting process continuously and effectively, and the established kinematic error models are effective although the interval is within a `large' range. It also shows the matching property between metamorphic principle and variable working tasks, and the mapping correlation between original designing parameters and kinematic errors of machines. This research develops a metamorphic CNC flame cutting machine and establishes kinematic error models for accuracy analysis of machine tools.

  6. Photometric solution and period analysis of the contact binary system AH Cnc

    NASA Astrophysics Data System (ADS)

    Peng, Ying-Jiang; Luo, Zhi-Quan; Zhang, Xiao-Bin; Deng, Li-Cai; Wang, Kun; Tian, Jian-Feng; Yan, Zheng-Zhou; Pan, Yang; Fang, Wei-Jing; Feng, Zhong-Wen; Tang, De-Lin; Liu, Qi-Li; Sun, Jin-Jiang; Zhou, Qiang

    2016-10-01

    Photometric observations of AH Cnc, a W UMa-type system in the open cluster M67, were carried out by using the 50BiN telescope. About 100 h of time-series B- and V -band data were taken, based on which eight new times of light minima were determined. By applying the Wilson-Devinney method, the light curves were modeled and a revised photometric solution of the binary system was derived. We confirmed that AH Cnc is a deep contact (f = 51%), low mass-ratio (q = 0.156) system. Adopting the distance modulus derived from study of the host cluster, we have re-calculated the physical parameters of the binary system, namely the masses and radii. The masses and radii of the two components were estimated to be respectively 1.188(±0.061) M ⊙, 1.332(±0.063) R ⊙ for the primary component and 0.185(±0.032) M ⊙, 0.592(±0.051) R ⊙ for the secondary. By adding the newly derived minimum timings to all the available data, the period variations of AH Cnc were studied. This shows that the orbital period of the binary is continuously increasing at a rate of dp/dt = 4.29 × 10‑10 d yr‑1. In addition to the long-term period increase, a cyclic variation with a period of 35.26 yr was determined, which could be attributed to an unresolved tertiary component of the system.

  7. Strange stars

    NASA Technical Reports Server (NTRS)

    Alcock, Charles; Farhi, Edward; Olinto, Angela

    1986-01-01

    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.

  8. Stars and Star Myths.

    ERIC Educational Resources Information Center

    Eason, Oliver

    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…

  9. Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

    PubMed Central

    Dhandapani, N. V.; Thangarasu, V. S.; Sureshkannan, G.

    2015-01-01

    This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results. PMID:26881267

  10. Performance Evaluation of Multi-Axis CNC Machine Tools by Interferometry Principle using Laser Calibration System

    NASA Astrophysics Data System (ADS)

    Barman, S.; Sen, R.

    2012-06-01

    Advancement in digital electronics and microprocessors has made the manufacturing sector capable to generate complex components within small tolerance zone in nanometre range at one machining center. All motion control systems have some form of position feed back system fitted with the machine. But the systems are not perfectly accurate due to the errors in the positioning performance of the machine tools which will change over time to time due to wear, damage and environmental effect. The complex structure of multi-axis CNC machine tools produces an inaccuracy at the tool tip caused by kinematic parameter deviations resulting in manufacturing errors, assembly error and quasi-static errors. Analysis of these errors using a laser measurement system provides the user with a way to achieve better accuracy, and hence higher quality output from these processes. In this paper, characteristic of the positioning errors of the axes of multi-axis CNC machine tools and the technique to measure the errors by a laser interferometer calibration system have been discussed and the positioning accuracy of the machine each axis has been verified.

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

    NASA Astrophysics Data System (ADS)

    Fan, Kuang-Chao; Wen, Kuang-Pu

    1993-09-01

    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.

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

    SciTech Connect

    Shara, Michael M.; Mizusawa, Trisha; Zurek, David; Wehinger, Peter; Martin, Christopher D.; Neill, James D.; Forster, Karl; Seibert, Mark

    2012-10-20

    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.

  13. cncRNAs: Bi-functional RNAs with protein coding and non-coding functions

    PubMed Central

    Kumari, Pooja; Sampath, Karuna

    2015-01-01

    For many decades, the major function of mRNA was thought to be to provide protein-coding information embedded in the genome. The advent of high-throughput sequencing has led to the discovery of pervasive transcription of eukaryotic genomes and opened the world of RNA-mediated gene regulation. Many regulatory RNAs have been found to be incapable of protein coding and are hence termed as non-coding RNAs (ncRNAs). However, studies in recent years have shown that several previously annotated non-coding RNAs have the potential to encode proteins, and conversely, some coding RNAs have regulatory functions independent of the protein they encode. Such bi-functional RNAs, with both protein coding and non-coding functions, which we term as ‘cncRNAs’, have emerged as new players in cellular systems. Here, we describe the functions of some cncRNAs identified from bacteria to humans. Because the functions of many RNAs across genomes remains unclear, we propose that RNAs be classified as coding, non-coding or both only after careful analysis of their functions. PMID:26498036

  14. Step-and-Repeat Nanoimprint-, Photo- and Laser Lithography from One Customised CNC Machine.

    PubMed

    Greer, Andrew Im; Della-Rosa, Benoit; Khokhar, Ali Z; Gadegaard, Nikolaj

    2016-12-01

    The conversion of a computer numerical control machine into a nanoimprint step-and-repeat tool with additional laser- and photolithography capacity is documented here. All three processes, each demonstrated on a variety of photoresists, are performed successfully and analysed so as to enable the reader to relate their known lithography process(es) to the findings. Using the converted tool, 1 cm(2) of nanopattern may be exposed in 6 s, over 3300 times faster than the electron beam equivalent. Nanoimprint tools are commercially available, but these can cost around 1000 times more than this customised computer numerical control (CNC) machine. The converted equipment facilitates rapid production and large area micro- and nanoscale research on small grants, ultimately enabling faster and more diverse growth in this field of science. In comparison to commercial tools, this converted CNC also boasts capacity to handle larger substrates, temperature control and active force control, up to ten times more curing dose and compactness. Actual devices are fabricated using the machine including an expanded nanotopographic array and microfluidic PDMS Y-channel mixers.

  15. Investigation on Effect of Material Hardness in High Speed CNC End Milling Process.

    PubMed

    Dhandapani, N V; Thangarasu, V S; Sureshkannan, G

    2015-01-01

    This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results. PMID:26881267

  16. Overview of Sustainability Studies of CNC Machining and LAM of Stainless Steel

    NASA Astrophysics Data System (ADS)

    Nyamekye, Patricia; Leino, Maija; Piili, Heidi; Salminen, Antti

    Laser additive manufacturing (LAM), known also as 3D printing, is a powder bed fusion (PBF) type of additive manufacturing (AM) technology used to fabricate metal parts out of metal powder. The development of the technology from building prototype parts to functional parts has increased remarkably in 2000s. LAM of metals is promising technology that offers new opportunities to manufacturing and to resource efficiency. However, there is only few published articles about its sustainability. Aim in this study was to create supply chain model of LAM and CNC machining and create a methodology to carry out a life cycle inventory (LCI) data collection for these techniques. The methodology of the study was literature review and scenario modeling. The acquisition of raw material, production phase and transportations were used as basis of comparison. The modelled scenarios were fictitious and created for industries, like aviation and healthcare that often require swift delivery as well as customized parts. The results of this study showed that the use of LAM offers a possibility to reduce downtime in supply chains of spare parts and reduce part inventory more effectively than CNC machining. Also the gap between customers and business is possible to be shortened with LAM thus offering a possibility to reduce emissions due to less transportation. The results also indicated weight reduction possibility with LAM due to optimized part geometry which allow lesser amount of metallic powder to be used in making parts.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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.

  18. Step-and-Repeat Nanoimprint-, Photo- and Laser Lithography from One Customised CNC Machine

    NASA Astrophysics Data System (ADS)

    Greer, Andrew IM; Della-Rosa, Benoit; Khokhar, Ali Z.; Gadegaard, Nikolaj

    2016-03-01

    The conversion of a computer numerical control machine into a nanoimprint step-and-repeat tool with additional laser- and photolithography capacity is documented here. All three processes, each demonstrated on a variety of photoresists, are performed successfully and analysed so as to enable the reader to relate their known lithography process(es) to the findings. Using the converted tool, 1 cm2 of nanopattern may be exposed in 6 s, over 3300 times faster than the electron beam equivalent. Nanoimprint tools are commercially available, but these can cost around 1000 times more than this customised computer numerical control (CNC) machine. The converted equipment facilitates rapid production and large area micro- and nanoscale research on small grants, ultimately enabling faster and more diverse growth in this field of science. In comparison to commercial tools, this converted CNC also boasts capacity to handle larger substrates, temperature control and active force control, up to ten times more curing dose and compactness. Actual devices are fabricated using the machine including an expanded nanotopographic array and microfluidic PDMS Y-channel mixers.

  19. Fast manufacturing of E-ELT mirror segments using CNC polishing

    NASA Astrophysics Data System (ADS)

    Gray, C.; Baker, I.; Davies, G.; Evans, R.; Field, N.; Fox-Leonard, T.; Messelink, W.; Mitchell, J.; Rees, P.; Waine, S.; Walker, D. D.; Yu, G.

    2013-09-01

    We report on the first-ever demonstration of grinding and polishing full-size, off-axis aspheric, mirror segments as prototypes for an extremely large telescope, processed entirely in the final hexagonal shape. We first describe the overall strategy for controlling form and mid spatial frequencies, at levels in the vicinity of <10nm RMS surface. This relies first on direct CNC grinding of the base-form of these 1.4m segments, using the Cranfield BoX™ machine. The segments are then mounted on a custom designed (Optic Glyndwr Optoelectronic Engineering Group) three segment hydraulic support, and CNC polished on a Zeeko IRP 1600 machine using a variety of custom tooling. We overview the fullaperture and sub-aperture metrology techniques used to close the process-loop and certify quality, all of which operate with the segment in-situ on the IRP1600. We then focus on the pristine edge-definition achieved by the combination of tool-lift and smoothing operations; results never previously demonstrated on full-size pre-cut hexagonal segments. Finally, the paper discusses the feasibility of scaling the process to deliver 931 segments in seven years, as required for the E-ELT project.

  20. Pulsating Stars

    NASA Astrophysics Data System (ADS)

    Catelan, M.; Smith, H. A.

    2015-03-01

    This book surveys our understanding of stars which change in brightness because they pulsate. Pulsating variable stars are keys to distance scales inside and beyond the Milky Way galaxy. They test our understanding not only of stellar pulsation theory but also of stellar structure and evolution theory. Moreover, pulsating stars are important probes of the formation and evolution of our own and neighboring galaxies. Our understanding of pulsating stars has greatly increased in recent years as large-scale surveys of pulsating stars in the Milky Way and other Local Group galaxies have provided a wealth of new observations and as space-based instruments have studied particular pulsating stars in unprecedented detail.

  1. Advanced CNC and CAM Series. Educational Resources for the Machine Tool Industry. Course Syllabi, Instructor's Handbook [and] Student Laboratory Manual.

    ERIC Educational Resources Information Center

    Texas State Technical Coll. System, Waco.

    This package consists of course syllabi, an instructor's handbook, and student laboratory manual for a 1-year vocational training program to prepare students for entry-level positions as advanced computer numerical control (CNC) and computer-assisted manufacturing (CAM) technicians.. The program was developed through a modification of the DACUM…

  2. Preparation of the CNC/Ag/beeswax composites for enhancing antibacterial and water resistance properties of paper.

    PubMed

    Liu, Kai; Liang, Hunan; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2016-05-20

    An effective method of preparing composites containing inorganic (Ag) and organic (beeswax) particles was established in this study. Ag nanoparticles were first immobilized on the cellulose nanocrystals (CNC) during the reduction of AgNO3 in the presence of CNC, then mixed with beeswax by high speed stirring. Scanning transmission electron microscopy (STEM) images indicated that Ag and beeswax particles were uniformly dispersed and stable in the network structure formed by CNC. Upon coating on a paper surface, a layer of beeswax film was evident based on scanning electron microscopy (SEM) images. The dynamic contact angle and antibacterial activity tests indicated that the contact angle of coated paper reached 113.06° and the growth inhibition of Escherichia coli increased to 99.96%, respectively, at a coating amount of 21.53 g/m(2). When applied onto paper surface by coating, the CNC/Ag/beeswax composites can impact paper with antibacterial property and improved water resistance. PMID:26917389

  3. SEAC4RS Data and Information Page

    Atmospheric Science Data Center

    2015-07-01

    ... Clouds and Climate Coupling by Regional Surveys ( SEAC4RS ) airborne field study was conducted from August 6 to September 23, 2014.  The ... and feedbacks of aerosol particles from anthropogenic pollution and biomass burning on meteorology and climate through changes in the ...

  4. STAR System.

    ERIC Educational Resources Information Center

    Doverspike, James E.

    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:…

  5. Massive Stars

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Villaver, Eva

    2009-11-01

    Participants; Preface Mario Livio and Eva Villaver; 1. High-mass star formation by gravitational collapse of massive cores M. R. Krumholz; 2. Observations of massive star formation N. A. Patel; 3. Massive star formation in the Galactic center D. F. Figer; 4. An X-ray tour of massive star-forming regions with Chandra L. K. Townsley; 5. Massive stars: feedback effects in the local universe M. S. Oey and C. J. Clarke; 6. The initial mass function in clusters B. G. Elmegreen; 7. Massive stars and star clusters in the Antennae galaxies B. C. Whitmore; 8. On the binarity of Eta Carinae T. R. Gull; 9. Parameters and winds of hot massive stars R. P. Kudritzki and M. A. Urbaneja; 10. Unraveling the Galaxy to find the first stars J. Tumlinson; 11. Optically observable zero-age main-sequence O stars N. R. Walborn; 12. Metallicity-dependent Wolf-Raynet winds P. A. Crowther; 13. Eruptive mass loss in very massive stars and Population III stars N. Smith; 14. From progenitor to afterlife R. A. Chevalier; 15. Pair-production supernovae: theory and observation E. Scannapieco; 16. Cosmic infrared background and Population III: an overview A. Kashlinsky.

  6. Hadron star models. [neutron stars

    NASA Technical Reports Server (NTRS)

    Cohen, J. M.; Boerner, G.

    1974-01-01

    The properties of fully relativistic rotating hadron star models are discussed using models based on recently developed equations of state. All of these stable neutron star models are bound with binding energies as high as about 25%. During hadron star formation, much of this energy will be released. The consequences, resulting from the release of this energy, are examined.

  7. Association between polymorphism of the norepinephrine transporter gene rs2242446 and rs5669 loci and depression disorders

    PubMed Central

    Pan, Yu; Cheng, Qi; Shan, Mo-Shui; Yan, Jin

    2015-01-01

    Objective: To explore the association between polymorphism of the norepinephrine transporter (NET) gene rs2242446 and rs5669 loci and depression in Chinese Han population. Methods: A case-control study was carried out, the gene types and allele distributions of NFT gene rs2242446 and rs5569 loci in 302 depression patients and 302 healthy controls were detected by Taqman SNP genotyping technology. Results: The gene types and allele frequency distributions of NFT gene rs2242446 and rs5569 loci had significant differences between case group and control group (rs2242446, x2=26.045, P<0.05, x2=8.827, P<0.05, rs5569, x2=42.47, P<0.05, x2=20.9, P<0.05). The CC genotype of NET gene rs2242446 locus and rs5569 loci was a protective factor of depression compared with the CT and TT genotypes. Conclusion: The NET genepoly morphism of rs2242446 and rs5569 loci was a ssociated with depression in Chinese Han population, in which the CC genotype of rs2242446 and rs5569 loci was a protective factor of depression. PMID:26770504

  8. Association between ANKK1 (rs1800497) and LTA (rs909253) Genetic Variants and Risk of Schizophrenia

    PubMed Central

    Arab, Arwa H.; Elhawary, Nasser A.

    2015-01-01

    Limited research has assessed associations between schizophrenia and genetic variants of the ankyrin repeat and kinase domain containing 1 (ANKK1) and lymphotoxin-alpha (LTA) genes among individuals of Middle Eastern ancestry. Here we present the first association study investigating the ANKK1 rs1800497 (T>C) and LTA rs909253 (A>G) single-nucleotide polymorphisms in an Egyptian population. Among 120 patients with DSM-IV and PANSS (Positive and Negative Syndrome Scale) assessments of schizophrenia and 100 healthy controls, we determined the genotypes for the polymorphisms using endonuclease digestion of amplified genomic DNA. Results confirmed previous findings from different ethnic populations, in that the rs1800497 and rs909253 polymorphisms were both associated with risk of schizophrenia. Differences between the genotypes of cases and controls were strongly significant (P = 0.0005 for rs1800497 and P = 0.001 for rs909253). The relative risk to schizophrenia was 1.2 (P = 0.01) for the C allele and 0.8 (P = 0.04) for the G allele. The CC, GG, and combined CC/AA genotypes were all more frequent in cases than in controls. These results support an association between ANKK1 and LTA genetic markers and vulnerability to schizophrenia and show the potential influence of just one copy of the mutant C or G allele in the Egyptian population. PMID:26114114

  9. Backlash Decrease System of Reducers/Gearboxes in Feed Kinematical Linkage Structure of CNC Machine Tools

    NASA Astrophysics Data System (ADS)

    Stan, G.

    2016-08-01

    Feed kinematic linkages of the CNC machine tools are built in camted cycle (closed loop) and their structures include reducers/gearboxes. as well. Because of the mechanical backlash between the flanks of the teeth of gearings, disturbances occur in the performance of a kinematic linkage as a whole (in terms of speed and position loops), thus leading to instability. This work presents a new system for decreasing the mechanical backlash that is based on a new type of cylindrical gearings with tapered teeth, allowing the backlash adjustment between the flanks of the joint teeth. The modality of acting in terms of decreasing the backlash on a reducer in the structure of a feed kinematic linkage is also detailed.

  10. Optimization of process parameters in CNC turning of aluminium alloy using hybrid RSM cum TLBO approach

    NASA Astrophysics Data System (ADS)

    Rudrapati, R.; Sahoo, P.; Bandyopadhyay, A.

    2016-09-01

    The main aim of the present work is to analyse the significance of turning parameters on surface roughness in computer numerically controlled (CNC) turning operation while machining of aluminium alloy material. Spindle speed, feed rate and depth of cut have been considered as machining parameters. Experimental runs have been conducted as per Box-Behnken design method. After experimentation, surface roughness is measured by using stylus profile meter. Factor effects have been studied through analysis of variance. Mathematical modelling has been done by response surface methodology, to made relationships between the input parameters and output response. Finally, process optimization has been made by teaching learning based optimization (TLBO) algorithm. Predicted turning condition has been validated through confirmatory experiment.

  11. The Structure and Principles of Work Intellectual Processing Control System on CNC

    NASA Astrophysics Data System (ADS)

    Nekrasov, R. Y.; Putilova, U. S.; Starikov, A. I.; Soloviev, I. V.; Bekareva, O. V.

    2016-04-01

    The high rate of technological progress imposes stringent quality demands of engineering production. The main requirement is dimensional accuracy of metal-cutting equipment with a minimal needed operating costs during the period of operation. The article considers the problem of increasing the accuracy of processing engineering products on CNC. The authors have proposed a solution of the problem by providing entering operational adjustment to the control of the trajectory of the executive bodies of the machine. The necessity of creation of mathematical models of processes in an automated process system operations (APSO). Based on the research, authors had proposed that a generalized scheme of diagnosis and operation input of corrections and approximate mathematical models of the individual processes of diagnosis.

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

    SciTech Connect

    2010-05-07

    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

  13. A diphoton resonance from bulk RS

    NASA Astrophysics Data System (ADS)

    Csáki, Csaba; Randall, Lisa

    2016-07-01

    Recent LHC data hinted at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to any other Standard Model particles would be too low to be detected so far. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from but close to the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.

  14. Association of BLK (rs13277113, rs2248932) polymorphism with systemic lupus erythematosus: a meta-analysis.

    PubMed

    Fan, Ye; Tao, Jin-Hui; Zhang, Li-Ping; Li, Lian-Hong; Ye, Dong-Qing

    2011-10-01

    The B-cell lymphocyte kinase (BLK) is a src-family protein tyrosine kinase specifically expressed in B-lineage cells that has been implicated in the pathogenesis of systemic lupus erythematosus (SLE) and has been investigated in numerous ethnically diverse studies. However, genetic association studies that have examined the association between BLK gene variants and SLE have produced conflicting results. To shed further light on this issue, we performed a meta-analysis of the association between rs13277113, rs2248932 polymorphism and SLE in different ethnic groups. An updated literature-based meta-analysis of six original articles involving 20,271 control individuals and 11,796 subjects with SLE was conducted. Crude ORs with 95% CIs were used to assess the strength of association between rs13277113, rs2248932 polymorphism and SLE risk. Publication bias was estimated using Egger's linear regression test. The authors assessed the evidence of genotypic association using STATA Version 10.0. The combined overall odds ratio, calculated for SLE and the risk A-allele of rs13277113 was 1.416 (95% CI: 1.358, 1.477). An odds ratio of 1.264 (95% CI: 1.208, 1.322) was found for the T-allele of rs2248932. Significant associations of rs13277113 and SLE were observed for dominant model (AA + AG vs. GG, OR: 1.518; 95% CI: 1.411, 1.632), and recessive model (AA vs. AG + GG, OR: 1.553; 95% CI: 1.461, 1.651); so were rs2248932 and SLE for dominant model (TT + TC vs. CC, OR: 1.342; 95% CI: 1.233, 1.460), and recessive model (TT vs. TC + CC, OR: 1.338; 95% CI: 1.257, 1.424). All of these were conducted in fixed effects model as heterogeneity was not detected. Tests for bias revealed no evidence of biases. On the assessment of available evidence, the authors concluded that moderate evidence exists for an association between the BLK rs13277113, rs2248932 variants and SLE. Therefore, further research is warranted on the role of BLK polymorphisms in the etiology of SLE.

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

    NASA Astrophysics Data System (ADS)

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

    1998-06-01

    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.

  16. Association of Polymorphisms (rs 1799782, rs25489 and rs25487) in XRCC1 and (rs 13181) XPD genes with Acute Coronary Artery Syndrome in Subjects from Multan, Pakistan.

    PubMed

    Hameed, Hafsa; Faryal, Maemona; Aslam, Muhammad Assad; Akbar, Atif; Saad, Abu Bakar Ali; Pasha, Muhammad Burhan; Latif, Muhammad; Rehan Sadiq Shaikh, Rehan Rehan Sadiq Shaikh; Ali, Muhammad; Iqbal, Furhan

    2016-05-01

    Acute coronary artery syndrome (ACS) is the major cause of mortality in Pakistan with genetic and environmental influence on the incidence of the disease. This case-control study was designed to find out if a correlation is existing between ACS and single nucleotide polymorphisms (SNPs) in DNA repair genes XPD [at codon 751, rs 13181 (Lys to Gln)] and XRCC1 [at codon 399, rs25487 (Arg to Gln); 280, rs25489 (Arg to His) and 194, rs 1799782 (Arg to Trp)] either individually or in various combination with each other (haplotype analysis). The objective of this study was to find out the association of various studied risk factors and serum lipid profile of the subjects with the disease, if any. PCR-RFLP method was used to determine genotype at specific codon in 221 subjects (115 ACS patients and 106 healthy controls) from Southern Punjab population. Genotypic and allelic frequency distribution among the cases and controls revealed that all the studied SNPs were not individually associated with the ACS. Haplotype analysis revealed that subjects having wild type combination of all three XRCC1 SNPs had greater susceptibility to ACS than any other studied genotypic combinations. Analysis of risk factors revealed that hypertension (P<0.001), age (P=0.05), education (P<0.001), gender (P<0.001), family history (P=0.005), smoking habit (P=0.002) and diabetes (P<0.001) were significantly associated with the incidence of ACS. Serum lipid profile analysis indicated that cholesterol level was significantly higher (P=0.048) in patients (161.5mg/dL) than controls (142.1mg/dL) while triglyceride remained unaffected (P=0.87) when compared between the two treatments. PMID:27166553

  17. OPN gene polymorphisms, rs17524488 GG/G, rs11730582 T/C, and rs9138 C/A, and cancer risk in a Chinese population.

    PubMed

    Mi, Yuanyuan; Ren, Kewei; Dai, Feng; Zhu, Lijie; Feng, Ninghan

    2015-09-15

    Previous studies have investigated the association between osteopontin (OPN) gene polymorphisms, rs17524488 (-156 GG/G), rs11730582 (-443 T/C), and rs9138 (C/A) and cancer risk in the Chinese population. However, the results are controversial and indefinite. We therefore carried out a meta-analysis to derive a more precise estimation of these associations. The PubMed database was systematically searched to identify potentially eligible reports. Crude odds ratios (OR) and 95% confidence intervals (CI) were used to assess the strength of associations between 3 OPN gene polymorphisms and cancer risk in a Chinese population. A total of 10 articles involving 2,391 cases and 3,007 controls were evaluated. The pooled OR indicated that OPN rs17524488 (-156 GG/G) polymorphism was significantly associated with cancer risk in Chinese population. In a stratified analysis by source of control, significant associations were also observed among rs17524488 (-156 GG/G) and rs11730582 (-443 T/C) polymorphisms and cancer. In addition, a stronger association was observed between rs9138 (C/A) polymorphism and cancer risk. In conclusion, this meta-analysis suggests that OPN rs17524488 (-156 GG/G), rs11730582 (-443 T/C), and rs9138 (C/A) polymorphisms may be associated with cancer susceptibility in the Chinese population. Nevertheless, further investigation on a larger population covering different ethnicities are warranted.

  18. Niobium in R And (S6, 6e) and HR 1105 (S5, 3). [S star abundance

    NASA Technical Reports Server (NTRS)

    Davis, D. N.

    1985-01-01

    Lines of the first multiplet of niobium are strong in R And and HR 1105. These lines are also present in other S stars: HR 8714, R Cam, V Cnc, R CMi, and T Sgr. They are also visible in the M stars, Beta-Peg and Mu-UMa. An approximation to the abundance ratio, Nb/Fe, has been deduced from pairs of lines having nearly equal intensity. In R And, the ratio is about 200 times the solar value. It is hoped that good plates will soon be obtained for the near infrared region, so that the significant Nb/Rb abundance ratio may be determined.

  19. An Analysis of Light Variations of RS Canum Venaticorum Binary Systems.

    NASA Astrophysics Data System (ADS)

    Caton, Daniel Bruce

    Photoelectric data for fourteen RS Canum Venaticorum binary systems were obtained by the author from 1978 through 1981, at Rosemary Hill Observatory. These data are presented in the form of light curves and tabulated magnitudes and heliocentric Julian Dates. The outside-of-eclipse points for eight systems were Fourier analyzed for measurement of any distortion wave in the light curve. The wave in RS Canum Venaticorum itself was found to have moved half a phase unit in only two years. A wave was discovered in the light curve of RZ Eridani, and was found to have changed in a manner consistent with the starspot model for RS CVn systems. The light curve for UX Comae Bernices was found to have a large amount of intrinsic scatter, and the system was found to be anomalously bright on one night. These characteristics suggest that some type of flare activity may be present in that system. The other five systems analyzed were found to have waves consistent with other published results, or to have no definite wave at all. The possibility of detecting spots and deriving spot sizes from secondary eclipse observations was also explored. For this purpose the Wilson-Devinney computer program for light curve synthesis was modified to allow spots on the secondary star. Comparison of computer synthesized secondary eclipses of spotted stars to actual observations showed that there is little chance of detecting fluctuations due to individual spots. It was found that there is even less chance for discriminating between a few large spots and a large number of smaller spots. However, the program did produce good fits to RS CVn light curves, using reasonable spot parameters.

  20. Radio stars.

    PubMed

    Hjellming, R M; Wade, C M

    1971-09-17

    Up to the present time six classes of radio stars have been established. The signals are almost always very faint and drastically variable. Hence their discovery has owed as much to serendipity as to the highly sophisticated equipment and techniques that have been used. When the variations are regular, as with the pulsars, this characteristic can be exploited very successfully in the search for new objects as well as in the detailed study of those that are already known. The detection of the most erratically variable radio stars, the flare stars and the x-ray stars, is primarily a matter of luck and patience. In the case of the novas, one at least knows where and oughly when to look for radio emission. A very sensitive interferometer is clearly the best instrument to use in the initial detection of a radio star. The fact that weak background sources are frequently present makes it essential to prove that the position of a radio source agrees with that of a star to within a few arc seconds. The potential of radio astronomy for the study of radio stars will not be realized until more powerful instruments than those that are available today can be utilized. So far, we have been able to see only the most luminous of the radio stars. PMID:17836594

  1. Star Polymers.

    PubMed

    Ren, Jing M; McKenzie, Thomas G; Fu, Qiang; Wong, Edgar H H; Xu, Jiangtao; An, Zesheng; Shanmugam, Sivaprakash; Davis, Thomas P; Boyer, Cyrille; Qiao, Greg G

    2016-06-22

    Recent advances in controlled/living polymerization techniques and highly efficient coupling chemistries have enabled the facile synthesis of complex polymer architectures with controlled dimensions and functionality. As an example, star polymers consist of many linear polymers fused at a central point with a large number of chain end functionalities. Owing to this exclusive structure, star polymers exhibit some remarkable characteristics and properties unattainable by simple linear polymers. Hence, they constitute a unique class of technologically important nanomaterials that have been utilized or are currently under audition for many applications in life sciences and nanotechnologies. This article first provides a comprehensive summary of synthetic strategies towards star polymers, then reviews the latest developments in the synthesis and characterization methods of star macromolecules, and lastly outlines emerging applications and current commercial use of star-shaped polymers. The aim of this work is to promote star polymer research, generate new avenues of scientific investigation, and provide contemporary perspectives on chemical innovation that may expedite the commercialization of new star nanomaterials. We envision in the not-too-distant future star polymers will play an increasingly important role in materials science and nanotechnology in both academic and industrial settings.

  2. Radio stars.

    PubMed

    Hjellming, R M; Wade, C M

    1971-09-17

    Up to the present time six classes of radio stars have been established. The signals are almost always very faint and drastically variable. Hence their discovery has owed as much to serendipity as to the highly sophisticated equipment and techniques that have been used. When the variations are regular, as with the pulsars, this characteristic can be exploited very successfully in the search for new objects as well as in the detailed study of those that are already known. The detection of the most erratically variable radio stars, the flare stars and the x-ray stars, is primarily a matter of luck and patience. In the case of the novas, one at least knows where and oughly when to look for radio emission. A very sensitive interferometer is clearly the best instrument to use in the initial detection of a radio star. The fact that weak background sources are frequently present makes it essential to prove that the position of a radio source agrees with that of a star to within a few arc seconds. The potential of radio astronomy for the study of radio stars will not be realized until more powerful instruments than those that are available today can be utilized. So far, we have been able to see only the most luminous of the radio stars.

  3. Mass and Reliability System (MaRS)

    NASA Technical Reports Server (NTRS)

    Barnes, Sarah

    2016-01-01

    The Safety and Mission Assurance (S&MA) Directorate is responsible for mitigating risk, providing system safety, and lowering risk for space programs from ground to space. The S&MA is divided into 4 divisions: The Space Exploration Division (NC), the International Space Station Division (NE), the Safety & Test Operations Division (NS), and the Quality and Flight Equipment Division (NT). The interns, myself and Arun Aruljothi, will be working with the Risk & Reliability Analysis Branch under the NC Division's. The mission of this division is to identify, characterize, diminish, and communicate risk by implementing an efficient and effective assurance model. The team utilizes Reliability and Maintainability (R&M) and Probabilistic Risk Assessment (PRA) to ensure decisions concerning risks are informed, vehicles are safe and reliable, and program/project requirements are realistic and realized. This project pertains to the Orion mission, so it is geared toward a long duration Human Space Flight Program(s). For space missions, payload is a critical concept; balancing what hardware can be replaced by components verse by Orbital Replacement Units (ORU) or subassemblies is key. For this effort a database was created that combines mass and reliability data, called Mass and Reliability System or MaRS. The U.S. International Space Station (ISS) components are used as reference parts in the MaRS database. Using ISS components as a platform is beneficial because of the historical context and the environment similarities to a space flight mission. MaRS uses a combination of systems: International Space Station PART for failure data, Vehicle Master Database (VMDB) for ORU & components, Maintenance & Analysis Data Set (MADS) for operation hours and other pertinent data, & Hardware History Retrieval System (HHRS) for unit weights. MaRS is populated using a Visual Basic Application. Once populated, the excel spreadsheet is comprised of information on ISS components including

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

    ScienceCinema

    None

    2016-07-12

    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

  5. Enigmatic star EZ Pegasi - a mystery solved

    SciTech Connect

    Howell, S.B.; Bopp, B.W.

    1985-01-01

    EZ Peg, a ninth-magnitude G star that has been classified by various authors as an irregular variable, a U Gem system, and a contact binary, is shown to have all the spectroscopic and photometric characteristics of an active-chromosphere RS CVn binary. It is suggested that the reported outburst of 1943, when the spectrum appeared to be that of a B star, never occurred. The strong Ca II H and K reversals, viewed with low spectral resolution, caused the photospheric Ca II absorption to appear abnormally weak, mimicking a much earlier spectral type. 20 references.

  6. High-Speed RaPToRS

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

    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.

  7. 55 CANCRI: A COPLANAR PLANETARY SYSTEM THAT IS LIKELY MISALIGNED WITH ITS STAR

    SciTech Connect

    Kaib, Nathan A.; Duncan, Martin J.; Raymond, Sean N.

    2011-12-15

    Although the 55 Cnc system contains multiple, closely packed planets that are presumably in a coplanar configuration, we use numerical simulations to demonstrate that they 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. Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. Because only the projected separation of the binary is known, we study this effect statistically, assuming an isotropic distribution for wide binary orbits. We find that the most likely projected spin-orbit angle is {approx}50 Degree-Sign , with a {approx}30% chance of a retrograde configuration. Transit observations of the innermost planet-55 Cnc e-may be used to verify these findings 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.

  8. An improved method for risk evaluation in failure modes and effects analysis of CNC lathe

    NASA Astrophysics Data System (ADS)

    Rachieru, N.; Belu, N.; Anghel, D. C.

    2015-11-01

    Failure mode and effects analysis (FMEA) is one of the most popular reliability analysis tools for identifying, assessing and eliminating potential failure modes in a wide range of industries. In general, failure modes in FMEA are evaluated and ranked through the risk priority number (RPN), which is obtained by the multiplication of crisp values of the risk factors, such as the occurrence (O), severity (S), and detection (D) of each failure mode. However, the crisp RPN method has been criticized to have several deficiencies. In this paper, linguistic variables, expressed in Gaussian, trapezoidal or triangular fuzzy numbers, are used to assess the ratings and weights for the risk factors S, O and D. A new risk assessment system based on the fuzzy set theory and fuzzy rule base theory is to be applied to assess and rank risks associated to failure modes that could appear in the functioning of Turn 55 Lathe CNC. Two case studies have been shown to demonstrate the methodology thus developed. It is illustrated a parallel between the results obtained by the traditional method and fuzzy logic for determining the RPNs. The results show that the proposed approach can reduce duplicated RPN numbers and get a more accurate, reasonable risk assessment. As a result, the stability of product and process can be assured.

  9. Design and manufacturing of cranioplasty implants by 3-axis cnc milling.

    PubMed

    Hieu, L C; Bohez, E; Vander Sloten, J; Oris, P; Phien, H N; Vatcharaporn, E; Binh, P H

    2002-01-01

    Although various techniques and materials have been used for making cranioplasty implants, personalized cranioplasty implants are high in cost because of expensive materials and production technology, long design and manufacturing time, and intensive labor use. This research was a part of our research project in ASEAN countries to investigate feasible technical solutions of minimizing the implant cost based on available production technologies in the region. The use of 3-axis CNC (Computer Numerical Control) milling techniques for making molds to fabricate PMMA implants was successfully investigated. With the development of a design support program bridging between Computer Aided Design (CAD) and Medical Image Processing (MIP) system, the time for geometrical modeling of implants and molds was reduced to half a day. The machining time to complete a mold was about 5 to 6 hours; and it took maximal 2 hours to fabricate an implant with self-curing PMMA and 3 and half hours for fabricating an implant with heat-curing PMMA. The cost of implants is acceptable for the ASEAN region. PMID:12368561

  10. An adaptive recurrent-neural-network motion controller for X-Y table in CNC machine.

    PubMed

    Lin, Faa-Jeng; Shieh, Hsin-Jang; Shieh, Po-Huang; Shen, Po-Hung

    2006-04-01

    In this paper, an adaptive recurrent-neural-network (ARNN) motion control system for a biaxial motion mechanism driven by two field-oriented control permanent magnet synchronous motors (PMSMs) in the computer numerical control (CNC) machine is proposed. In the proposed ARNN control system, a RNN with accurate approximation capability is employed to approximate an unknown dynamic function, and the adaptive learning algorithms that can learn the parameters of the RNN on line are derived using Lyapunov stability theorem. Moreover, a robust controller is proposed to confront the uncertainties including approximation error, optimal parameter vectors, higher-order terms in Taylor series, external disturbances, cross-coupled interference and friction torque of the system. To relax the requirement for the value of lumped uncertainty in the robust controller, an adaptive lumped uncertainty estimation law is investigated. Using the proposed control, the position tracking performance is substantially improved and the robustness to uncertainties including cross-coupled interference and friction torque can be obtained as well. Finally, some experimental results of the tracking of various reference contours demonstrate the validity of the proposed design for practical applications. PMID:16602590

  11. Cost minimizing of cutting process for CNC thermal and water-jet machines

    NASA Astrophysics Data System (ADS)

    Tavaeva, Anastasia; Kurennov, Dmitry

    2015-11-01

    This paper deals with optimization problem of cutting process for CNC thermal and water-jet machines. The accuracy of objective function parameters calculation for optimization problem is investigated. This paper shows that working tool path speed is not constant value. One depends on some parameters that are described in this paper. The relations of working tool path speed depending on the numbers of NC programs frames, length of straight cut, configuration part are presented. Based on received results the correction coefficients for working tool speed are defined. Additionally the optimization problem may be solved by using mathematical model. Model takes into account the additional restrictions of thermal cutting (choice of piercing and output tool point, precedence condition, thermal deformations). At the second part of paper the non-standard cutting techniques are considered. Ones may lead to minimizing of cutting cost and time compared with standard cutting techniques. This paper considers the effectiveness of non-standard cutting techniques application. At the end of the paper the future research works are indicated.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  13. Spectroscopic orbits and variations of RS Ophiuchi

    NASA Astrophysics Data System (ADS)

    Brandi, E.; Quiroga, C.; Mikołajewska, J.; Ferrer, O. E.; García, L. G.

    2009-04-01

    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 Hα 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

  14. STARS no star on Kauai

    SciTech Connect

    Jones, M.

    1993-04-01

    The island of Kuai, home to the Pacific Missile Range Facility, is preparing for the first of a series of Star Wars rocket launches expected to begin early this year. The Strategic Defense Initiative plans 40 launches of the Stategic Target System (STARS) over a 10-year period. The focus of the tests appears to be weapons and sensors designed to combat multiple-warhead ICBMs, which will be banned under the START II Treaty that was signed in January. The focus of this article is to express the dubious value of testing the STARS at a time when their application will not be an anticipated problem.

  15. Coordinated ultraviolet and radio observations of selected nearby stars

    NASA Technical Reports Server (NTRS)

    Lang, Kenneth R.

    1987-01-01

    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.

  16. Ruthenium(II) Complexes Containing Lutidine-Derived Pincer CNC Ligands: Synthesis, Structure, and Catalytic Hydrogenation of C-N bonds.

    PubMed

    Hernández-Juárez, Martín; López-Serrano, Joaquín; Lara, Patricia; Morales-Cerón, Judith P; Vaquero, Mónica; Álvarez, Eleuterio; Salazar, Verónica; Suárez, Andrés

    2015-05-11

    A series of Ru complexes containing lutidine-derived pincer CNC ligands have been prepared by transmetalation with the corresponding silver-carbene derivatives. Characterization of these derivatives shows both mer and fac coordination of the CNC ligands depending on the wingtips of the N-heterocyclic carbene fragments. In the presence of tBuOK, the Ru-CNC complexes are active in the hydrogenation of a series of imines. In addition, these complexes catalyze the reversible hydrogenation of phenantridine. Detailed NMR spectroscopic studies have shown the capability of the CNC ligand to be deprotonated and get involved in ligand-assisted activation of dihydrogen. More interestingly, upon deprotonation, the Ru-CNC complex 5 e(BF4 ) is able to add aldimines to the metal-ligand framework to yield an amido complex. Finally, investigation of the mechanism of the hydrogenation of imines has been carried out by means of DFT calculations. The calculated mechanism involves outer-sphere stepwise hydrogen transfer to the C-N bond assisted either by the pincer ligand or a second coordinated H2 molecule.

  17. The radish defensins RsAFP1 and RsAFP2 act synergistically with caspofungin against Candida albicans biofilms.

    PubMed

    Vriens, Kim; Cools, Tanne L; Harvey, Peta J; Craik, David J; Braem, Annabel; Vleugels, Jozef; De Coninck, Barbara; Cammue, Bruno P A; Thevissen, Karin

    2016-01-01

    The radish defensin RsAFP2 was previously characterized as a peptide with potent antifungal activity against several plant pathogenic fungi and human pathogens, including Candida albicans. RsAFP2 induces apoptosis and impairs the yeast-to-hypha transition in C. albicans. As the yeast-to-hypha transition is considered important for progression to mature biofilms, we analyzed the potential antibiofilm activity of recombinant (r)RsAFP2, heterologously expressed in Pichia pastoris, against C. albicans biofilms. We found that rRsAFP2 prevents C. albicans biofilm formation with a BIC-2 (i.e., the minimal rRsAFP2 concentration that inhibits biofilm formation by 50% as compared to control treatment) of 1.65 ± 0.40 mg/mL. Moreover, biofilm-specific synergistic effects were observed between rRsAFP2 doses as low as 2.5 μg/mL to 10 μg/mL and the antimycotics caspofungin and amphotericin B, pointing to the potential of RsAFP2 as a novel antibiofilm compound. In addition, we characterized the solution structure of rRsAFP2 and compared it to that of RsAFP1, another defensin present in radish seeds. These peptides have similar amino acid sequences, except for two amino acids, but rRsAFP2 is more potent than RsAFP1 against planktonic and biofilm cultures. Interestingly, as in case of rRsAFP2, also RsAFP1 acts synergistically with caspofungin against C. albicans biofilms in a comparable low dose range as rRsAFP2. A structural comparison of both defensins via NMR analysis revealed that also rRsAFP2 adopts the typical cysteine-stabilized αβ-motif of plant defensins, however, no structural differences were found between these peptides that might result in their differential antifungal/antibiofilm potency. This further suggests that the conserved structure of RsAFP1 and rRsAFP2 bears the potential to synergize with antimycotics against C. albicans biofilms. PMID:26592804

  18. Association analysis of APOA5 rs662799 and rs3135506 polymorphisms with obesity in Moroccan patients.

    PubMed

    Lakbakbi El Yaagoubi, F; Charoute, H; Bakhchane, A; Ajjemami, M; Benrahma, H; Errouagui, A; Kandil, M; Rouba, H; Barakat, A

    2015-12-01

    The aim of the present study is to explore the association between the APOA5 polymorphisms and haplotypes with obesity in Moroccan patients. The study was performed in 459 subjects, Obese (n=164) and non-obese (n=295). All subjects were genotyped for the APOA5 -1131T>C (rs662799) and c.56C>G (rs3135506) polymorphisms. The contribution of APOA5 polymorphisms and haplotypes in the increased risk of obesity were explored using logistic regression analyses. The -1131T>C and c.56C>G polymorphisms were significantly associated with obesity. Both polymorphisms were strongly associated with increased BMI. Analysis of constructed haplotypes showed a significant association between CG haplotype and susceptibility to obesity (OR [95%CI]=3.09 [1.93-4.97]; P<0.001). These results support a potential role for APOA5 common variants and related haplotypes as risk factors for obesity.

  19. Genetic Variations rs11892031 and rs401681 Are Associated with Bladder Cancer Risk in a Chinese Population

    PubMed Central

    Zhang, Yu; Sun, Yan; Chen, Tao; Hu, Hailong; Xie, Wanqin; Qiao, Zhihui; Ding, Na; Xie, Linguo; Li, Sheng; Wang, Wenlong; Xing, Chen; Wang, Yihan; Qie, Yunkai; Wu, Changli

    2014-01-01

    Genome-wide association studies (GWAS) have identified a number of genetic variants associated with risk of bladder cancer in populations of European descent. Here, we assessed association of two of these variants, rs11892031 (2q37.1 region) and rs401681 (5p15.33 region) in a Chinese case-control study, which included 367 bladder cancer cases and 420 controls. We found that the AC genotype of rs11892031 was associated with remarkably decreased risk of bladder cancer (adjusted odds ratio (OR), 0.27; 95% confidence interval (CI), 0.09–0.81; p = 0.019), compared with the AA genotype of rs11892031; and that CT/CC genotypes of rs401681 were associated with significantly increased risk of bladder cancer (adjusted OR, 1.79; 95% CI, 1.10–2.91; p = 0.02), compared with the TT genotype of rs401681. We further conducted stratification analysis to examine the correlation between single nucleotide polymorphism (SNP) rs11892031/rs401681 and tumor grade/stage. Results showed that heterogeneity in ORs of tumor categories was not significant for either rs11892031 or rs401681 (p > 0.05), indicating that the two SNPs seemingly do not associate with tumor grade and stage of bladder cancer in our study population. The present study suggests that the SNPs rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population. Future analyses will be conducted with more participants recruited in a case-control study. PMID:25347272

  20. Genetic variations rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population.

    PubMed

    Zhang, Yu; Sun, Yan; Chen, Tao; Hu, Hailong; Xie, Wanqin; Qiao, Zhihui; Ding, Na; Xie, Linguo; Li, Sheng; Wang, Wenlong; Xing, Chen; Wang, Yihan; Qie, Yunkai; Wu, Changli

    2014-01-01

    Genome-wide association studies (GWAS) have identified a number of genetic variants associated with risk of bladder cancer in populations of European descent. Here, we assessed association of two of these variants, rs11892031 (2q37.1 region) and rs401681 (5p15.33 region) in a Chinese case-control study, which included 367 bladder cancer cases and 420 controls. We found that the AC genotype of rs11892031 was associated with remarkably decreased risk of bladder cancer (adjusted odds ratio (OR), 0.27; 95% confidence interval (CI), 0.09-0.81; p=0.019), compared with the AA genotype of rs11892031; and that CT/CC genotypes of rs401681 were associated with significantly increased risk of bladder cancer (adjusted OR, 1.79; 95% CI, 1.10-2.91; p=0.02), compared with the TT genotype of rs401681. We further conducted stratification analysis to examine the correlation between single nucleotide polymorphism (SNP) rs11892031/rs401681 and tumor grade/stage. Results showed that heterogeneity in ORs of tumor categories was not significant for either rs11892031 or rs401681 (p>0.05), indicating that the two SNPs seemingly do not associate with tumor grade and stage of bladder cancer in our study population. The present study suggests that the SNPs rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population. Future analyses will be conducted with more participants recruited in a case-control study.

  1. Polymorphisms in Four Genes (KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963) and Their Correlation with Type 2 Diabetes Mellitus in Han Chinese in Henan Province, China

    PubMed Central

    Gao, Kaiping; Wang, Jinjin; Li, Linlin; Zhai, Yujia; Ren, Yongcheng; You, Haifei; Wang, Bingyuan; Wu, Xuli; Li, Jianna; Liu, Zichen; Li, Xiong; Huang, Yaxin; Luo, Xin-Ping; Hu, Dongsheng; Ohno, Kinji; Wang, Chongjian

    2016-01-01

    Genetic variants at KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963 have been associated with type 2 diabetes mellitus (T2DM), but the results are contradictory in Chinese populations. The aim of the present study was to investigate the association of these four SNPs with T2DM in a large population of Han Chinese at Henan province, China. Seven-hundred-thirty-six patients with T2DM (cases) and Seven-hundred-sixty-eight healthy glucose-tolerant controls were genotyped for KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963. The association of genetic variants in these four genes with T2DM was analyzed using multivariate logistic regression. Genotypes and allele distributions of KCNQ1 rs151290 were significantly different between the cases and controls (p < 0.05). The AC and CC genotypes and the combined AC + CC genotype of rs151290 in KCNQ1 were associated with increases risk of T2DM before (OR = 1.482, 95% CI = 1.062–2.069; p = 0.021; OR = 1.544, 95% CI = 1.097–2.172, p = 0.013; and OR = 1.509, 95% CI = 1.097–2.077, p = 0.011, respectively) and after (OR = 1.539, 95% CI = 1.015–2.332, p = 0.042; OR = 1.641, 95% CI = 1.070–2.516, p = 0.023; and OR = 1.582, 95% CI = 1.061–2.358, p = 0.024; respectively) adjustment for sex, age, anthropometric measurements, biochemical indexes, smoking and alcohol consumption. Consistent with results of genotype analysis, the C allele of rs151290 in KCNQ1 was also associated with increased risk of T2DM (OR = 1.166, 95% CI = 1.004–1.355, p = 0.045). No associations between genetic variants of KLF14 rs972283, GCKR rs780094 or MTNR1B rs10830963 and T2DM were detected. The AC and CC genotypes and the C allele of rs151290 in KCNQ1 may be risk factors for T2DM in Han Chinese in Henan province. PMID:26927145

  2. Polymorphisms in Four Genes (KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963) and Their Correlation with Type 2 Diabetes Mellitus in Han Chinese in Henan Province, China.

    PubMed

    Gao, Kaiping; Wang, Jinjin; Li, Linlin; Zhai, Yujia; Ren, Yongcheng; You, Haifei; Wang, Bingyuan; Wu, Xuli; Li, Jianna; Liu, Zichen; Li, Xiong; Huang, Yaxin; Luo, Xin-Ping; Hu, Dongsheng; Ohno, Kinji; Wang, Chongjian

    2016-03-01

    Genetic variants at KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963 have been associated with type 2 diabetes mellitus (T2DM), but the results are contradictory in Chinese populations. The aim of the present study was to investigate the association of these four SNPs with T2DM in a large population of Han Chinese at Henan province, China. Seven-hundred-thirty-six patients with T2DM (cases) and Seven-hundred-sixty-eight healthy glucose-tolerant controls were genotyped for KCNQ1 rs151290, KLF14 rs972283, GCKR rs780094 and MTNR1B rs10830963. The association of genetic variants in these four genes with T2DM was analyzed using multivariate logistic regression. Genotypes and allele distributions of KCNQ1 rs151290 were significantly different between the cases and controls (p < 0.05). The AC and CC genotypes and the combined AC + CC genotype of rs151290 in KCNQ1 were associated with increases risk of T2DM before (OR = 1.482, 95% CI = 1.062-2.069; p = 0.021; OR = 1.544, 95% CI = 1.097-2.172, p = 0.013; and OR = 1.509, 95% CI = 1.097-2.077, p = 0.011, respectively) and after (OR = 1.539, 95% CI = 1.015-2.332, p = 0.042; OR = 1.641, 95% CI = 1.070-2.516, p = 0.023; and OR = 1.582, 95% CI = 1.061-2.358, p = 0.024; respectively) adjustment for sex, age, anthropometric measurements, biochemical indexes, smoking and alcohol consumption. Consistent with results of genotype analysis, the C allele of rs151290 in KCNQ1 was also associated with increased risk of T2DM (OR = 1.166, 95% CI = 1.004-1.355, p = 0.045). No associations between genetic variants of KLF14 rs972283, GCKR rs780094 or MTNR1B rs10830963 and T2DM were detected. The AC and CC genotypes and the C allele of rs151290 in KCNQ1 may be risk factors for T2DM in Han Chinese in Henan province. PMID:26927145

  3. Optical resolution by preferential crystallization of (1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid.

    PubMed

    Shiraiwa, Tadashi; Kiyoe, Ryuuichi

    2005-09-01

    The racemic structure of (1RS,3RS)-1,2,3,4-tetrahydro-6,7-dihydroxy-1-methyl-3-isoquinolinecarboxylic acid [(1RS,3RS)-1] was examined based on the melting point, solubility, and IR spectrum, with the aim of optical resolution by preferential crystallization. (1RS,3RS)-1 was indicated from these results to exist as a conglomerate. The successive optical resolution by preferential crystallization of (1RS,3RS)-1 yielded (1S,3S)- and (1R,3R)-1 with optical purities of 85--95% at 66--81% degrees of resolution, which were fully purified by recrystallization.

  4. Discovery of three new RS Canum Venaticorum-like counterparts to HEAO I X-ray sources

    NASA Technical Reports Server (NTRS)

    Buckley, D. A. H.; Tuohy, I. R.; Remillard, R. A.; Bradt, H. V.; Schwartz, D. A.

    1987-01-01

    The identification of three high-latitude HEAO I Scanning Modulation Collimator X-ray sources with the chromospherically active RS CVn-like stars HD 113816, HD 146413, and HD 39576 is reported. Optical observations, including coude spectroscopy and broad-band and narrow band photoelectric photometry are presented. The Ca II emission strength of all three stars shows that they are chromospherically active. HD 146413 and HD 39576 exhibit variable X-ray emission in the 1-13 keV energy range, while HD 113816 is a softer and steadier source. The level of X-ray flux detected from these three stars is some one to two orders of magnitude higher than predicted empirically from the Ca II emission fluxes. It is proposed that this emission results from flarelike activity.

  5. Further application and amelioration of a novel CNC aspheric grinding machine

    NASA Astrophysics Data System (ADS)

    Hu, Jianjun; Pan, Junhua

    2006-02-01

    Aspheric surface can be thought as being enveloped by a series of spherical surfaces with their centre on the same axis but having different positions. These spherical surfaces are tangent with the aspheric surface. A Φ600 CNC aspheric grinding machine with this novel operating principleis manufactured. The machine was reported in August 2005. We choose δ p, ɛ and α p as the key parameters of our grinding machine. δ p is the distance between the cup shaped tool's bottom and the vertex of the aspheric surface. α p is the rotational angle of the cup shaped tool. ɛ is the space angle of the cup shaped tool during the fabrication process of convex aspheric surface. This grinding machine can be used to fabricate a conic concave aspheric surface continuously about three hours. But we need change the cup shaped tool one time when we fabricate a conic convex aspheric surface in also about three hours. The grinding machine can also be used to fabricate high-order aspheric surface. In the last report we intoroduced that we used this machined fabricating a RC telescope system's primary and the secondary mirror. The PV-value is less than 5μm for the primary Φ350 concave hyperbolic aspheric surface which departure is about 55μm. The residual errors can be removed easily. This machine have been improved both the cup shaped tool and filter system. Using this grinding machine we have fabricated another Φ460 concave aspheric surface during the last month. The PV-values of these two mirrors are both less than 7μm. The aspheric grinding machine can be fitted for fabricating concave conicoids.

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

    SciTech Connect

    Dawson, Rebekah I.; Fabrycky, Daniel C. E-mail: daniel.fabrycky@gmail.co

    2010-10-10

    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.

  7. FPGA-Based Fused Smart-Sensor for Tool-Wear Area Quantitative Estimation in CNC Machine Inserts

    PubMed Central

    Trejo-Hernandez, Miguel; Osornio-Rios, Roque Alfredo; de Jesus Romero-Troncoso, Rene; Rodriguez-Donate, Carlos; Dominguez-Gonzalez, Aurelio; Herrera-Ruiz, Gilberto

    2010-01-01

    Manufacturing processes are of great relevance nowadays, when there is a constant claim for better productivity with high quality at low cost. The contribution of this work is the development of a fused smart-sensor, based on FPGA to improve the online quantitative estimation of flank-wear area in CNC machine inserts from the information provided by two primary sensors: the monitoring current output of a servoamplifier, and a 3-axis accelerometer. Results from experimentation show that the fusion of both parameters makes it possible to obtain three times better accuracy when compared with the accuracy obtained from current and vibration signals, individually used. PMID:22319304

  8. Responding to the 5Rs: An Alternate Perspective of Slowmation

    ERIC Educational Resources Information Center

    Kidman, Gillian; Keast, Stephen; Cooper, Rebecca

    2012-01-01

    This paper is a response to Hoban and Neilsen's (2010) Five Rs model for understanding how learners engage with slowmation. An alternative model (the Learning MMAEPER Model) that builds on the 5Rs model is explained in terms of its use in secondary science preservice teacher education. To probe into the surface and deep learning that can occur…

  9. 10 CFR 434.103 - Referenced standards (RS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Referenced standards (RS). 434.103 Section 434.103 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Administration and Enforcement-General § 434.103 Referenced standards (RS)....

  10. 10 CFR 434.103 - Referenced standards (RS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Referenced standards (RS). 434.103 Section 434.103 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Administration and Enforcement-General § 434.103 Referenced standards (RS). 103.1...

  11. 10 CFR 434.103 - Referenced standards (RS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Referenced standards (RS). 434.103 Section 434.103 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Administration and Enforcement-General § 434.103 Referenced standards (RS)....

  12. 10 CFR 434.103 - Referenced standards (RS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Referenced standards (RS). 434.103 Section 434.103 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Administration and Enforcement-General § 434.103 Referenced standards (RS)....

  13. 10 CFR 434.103 - Referenced standards (RS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Referenced standards (RS). 434.103 Section 434.103 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Administration and Enforcement-General § 434.103 Referenced standards (RS)....

  14. Effect of a gelatin-based edible coating containing cellulose nanocrystals (CNC) on the quality and nutrient retention of fresh strawberries during storage

    NASA Astrophysics Data System (ADS)

    Fakhouri, F. M.; Casari, A. C. A.; Mariano, M.; Yamashita, F.; Innocnentini Mei, L. H.; Soldi, V.; Martelli, S. M.

    2014-08-01

    Strawberry is a non-climacteric fruit with a very short postharvest shelf-life. Loss of quality in this fruit is mostly due to its relatively high metabolic activity and sensitivity to fungal decay, meanly grey mold (Botrytis cinerea). In this study, the ability of gelatin coatings containing cellulose nanocrystals (CNC) to extend the shelf-life of strawberry fruit (Fragaria ananassa) over 8 days were studied. The filmogenic solution was obtained by the hydration of 5 g of gelatin (GEL) in 100 mL of distillated water containing different amounts of CNC dispersion (10 mg CNC/g of GEL or 50 mg of CNC/g of GEL) for 1 hour at room temperature. After this period, the solution was heated to 70 °C and maintained at this temperature for 10 minutes. The plasticizer (glycerol) (10g/100g of the GEL) was then added with constant, gentle stirring in order to avoid forming air bubbles and also to avoid gelatin denaturation until complete homogenization. Strawberries (purchased at the local market) were immersed in the filmogenic solution for 1 minute and after coated were dried at 15 °C by 24 hours. The strawberries were then kept under refrigeration and characterized in terms of their properties (weight loss, ascorbic acid content, titratable acidity, water content). The results have shown that samples covered with GEL/CNC had a significant improvement in its shelf- life. For instance, for the control sample (without coating) the weight loss after 8 days of storage was around 65%, while covered samples loss in the range of 31-36%. Edible coating was also effective in the retention of ascorbic acid (AA) in the strawberries, while control sample presented a fast decay in the AA content, covered samples showed a slow decay in the AA concentration. Moreover, the use of GEL/CNC edible coating had an antimicrobial effect in the fruits.

  15. High pressure intensification of cassava resistant starch (RS3) yields.

    PubMed

    Lertwanawatana, Proyphon; Frazier, Richard A; Niranjan, Keshavan

    2015-08-15

    Cassava starch, typically, has resistant starch type 3 (RS3) content of 2.4%. This paper shows that the RS3 yields can be substantially enhanced by debranching cassava starch using pullulanase followed by high pressure or cyclic high-pressure annealing. RS3 yield of 41.3% was obtained when annealing was carried out at 400MPa/60°C for 15 min, whereas it took nearly 8h to obtain the same yield under conventional atmospheric annealing at 60°C. The yield of RS3 could be further significantly increased by annealing under 400 MPa/60°C pressure for 15 min followed by resting at atmospheric pressure for 3h 45 min, and repeating this cycle for up to six times. Microstructural surface analysis of the product under a scanning electron microscope showed an increasingly rigid density of the crystalline structure formed, confirming higher RS3 content.

  16. The evolution of the Three Rs.

    PubMed

    Farnaud, Sebastien

    2009-07-01

    Whilst the whole world is celebrating the bicentenary of the birth of Charles Darwin and the 150th anniversary of the publication of his renowned book, The Origin of Species, another anniversary should not be forgotten - the publication of The Principles of Humane Experimental Technique by W.M.S. Russell and R.L. Burch. The concomitance of the anniversaries of the two publications is not a coincidence, since, as reflected by the numerous quotes chosen by Russell from Darwin's masterpiece, numerous analogies can be found between the two works and the new ideas they describe. From a discrete birth, and after decades of struggle, the Three Rs concept can now celebrate its 50th anniversary, the result of its evolution through harsh selection and adaptation. The emergence of new types of techniques, in combination with the descent of modified old ones, testify to the undeniable change in our society toward a more efficient and more ethical science, through the progressive replacement of animal models. Both Darwin and Russell would no doubt have welcomed such progress, not only in terms of science, but also of moral values. One could also expect that, if Russell could have foreseen the incredible technological advances achieved 50 years later, where Replacement becomes a reality, as illustrated by some edifying examples, The Principles of Humane Experimental Technique would have probably been defined as the One R concept. PMID:19678725

  17. The evolution of the Three Rs.

    PubMed

    Farnaud, Sebastien

    2009-07-01

    Whilst the whole world is celebrating the bicentenary of the birth of Charles Darwin and the 150th anniversary of the publication of his renowned book, The Origin of Species, another anniversary should not be forgotten - the publication of The Principles of Humane Experimental Technique by W.M.S. Russell and R.L. Burch. The concomitance of the anniversaries of the two publications is not a coincidence, since, as reflected by the numerous quotes chosen by Russell from Darwin's masterpiece, numerous analogies can be found between the two works and the new ideas they describe. From a discrete birth, and after decades of struggle, the Three Rs concept can now celebrate its 50th anniversary, the result of its evolution through harsh selection and adaptation. The emergence of new types of techniques, in combination with the descent of modified old ones, testify to the undeniable change in our society toward a more efficient and more ethical science, through the progressive replacement of animal models. Both Darwin and Russell would no doubt have welcomed such progress, not only in terms of science, but also of moral values. One could also expect that, if Russell could have foreseen the incredible technological advances achieved 50 years later, where Replacement becomes a reality, as illustrated by some edifying examples, The Principles of Humane Experimental Technique would have probably been defined as the One R concept.

  18. Four New Variable Stars in Ophiuchus

    NASA Astrophysics Data System (ADS)

    Franco, Lorenzo; Marchini, Alessandro; Papini, Riccardo

    2011-03-01

    Four new variable stars were discovered by serendipity in the Ophiuchus constellation during photometric analysis of the NEO Asteroid (1988 PA), pictures taken in July 2010 from A81 Balzaretto Observatory in Rome. Based on their light curves and colour indexes, the stars were classified in their variable class and registered in the Variable Star Index (VSX) hosted in the AAVSO web site, respectively as one eclipsing variable EA-type or short period eclipsing subgroup of RS CVn-type (UCAC3 196-166827), identified as the optical counterpart of 1RXS J180755.7+074717 X-ray source, two eclipsing binaries EW-type (UCAC3 196-166958 and UCAC3 196-167279) and one very likely as pulsating variable High Amplitude δ,, Scuti type (HADS) or SX Phe (UCAC3 196-167073).

  19. Period04 FCAPT uvby Photometric Studies of Eight Magnetic CP Stars

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.; Dukes, Robert J.

    2014-06-01

    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.

  20. Star quality.

    PubMed

    Dent, Emma

    2007-09-20

    Around 150 wards are participating in the voluntary Star Wards scheme to provide mental health inpatients with more activities with therapeutic value. Suggested activities range from a library, to horse riding Internet access and comedy. Service users are particularly keen to have more exercise, which can be a challenge in inpatient settings. PMID:17970387

  1. Star Power

    ScienceCinema

    None

    2016-07-12

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  2. Star Power

    SciTech Connect

    2014-10-17

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  3. Association of Choline Acetyltransferase Gene Polymorphisms (SNPs rs868750G/A, rs1880676G/A, rs2177369G/A and rs3810950G/A) with Alzheimer’s Disease Risk: A Meta-Analysis

    PubMed Central

    Yuan, Hai; Xia, Qing; Ling, Kang; Wang, Xiaotong; Wang, Xiumin; Du, Xunping

    2016-01-01

    Background Epidemiological studies have investigated the role of choline acetyltransferase (ChAT) in Alzheimer’s disease (AD). ChAT gene polymorphisms (SNPs rs868750G/A, rs1880676G/A, rs2177369G/A, and rs3810950G/A) may be associated with the risk of AD. In this meta-analysis, we determined the relationship between the four polymorphisms and the risk of AD. Methods We searched MEDLINE, EMBASE, and HuGEnet databases for studies linking the four polymorphisms with AD risk. We included 16 articles in our meta-analysis to assess the association between the four polymorphisms and susceptibility to AD by calculating the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Results The combined results showed no significant association with rs1880676G/A and rs2177369G/A polymorphisms. The risk of AD (GG+GA versus AA: OR = 0.01, 95%CI = 0.01–0.02, P < 0.05; GG versus GA+AA: OR = 0.85, 95%CI = 0.72–1.00, P = 0.05; GA versus AA: OR = 0.60, 95% CI = 0.37–0.98, P = 0.04) with rs868750G/A polymorphism, or the association of rs3810950G/A polymorphism with AD risk in the overall population (GA versus AA: OR = 0.64, 95% CI = 0.44–0.93, P = 0.02; GG+GA versus AA: OR = 0.62, 95% CI = 0.39–0.97, P = 0.04) or Asian group (GA versus AA: OR = 0.50, 95% CI = 0.32–0.76, P = 0.001, and GG+GA versus AA: OR = 0.46, 95% CI = 0.30–0.09, P = 0.0002) was demonstrated. Conclusions Our meta-analysis suggested that rs1880670G/A, and rs2177369 G/A polymorphisms were not risk factors for AD. However, rs3810950G/A, or rs868750G/A genetic polymorphism was a genetic risk factor for the development of AD. The rs3810950G/A polymorphism had a negative effect on the risk of AD for GA or GG+GA genotypes compared with AA in the overall population or Asians. PMID:27390868

  4. Frequency of rs731236 (Taql), rs2228570 (Fok1) of Vitamin-D Receptor (VDR) gene in Emirati healthy population

    PubMed Central

    Osman, Enas; Al Anouti, Fatme; El ghazali, Gehad; Haq, Afrozul; Mirgani, Rajaa; Al Safar, Habiba

    2015-01-01

    Vitamin D is getting more attention everyday due to its importance in maintaining bone and calcium homeostasis, cellular proliferation, differentiation and immune response. Vitamin D is derived from diet or elicited in the skin by the activation of 7-dehydrocholesterol, which is an inert molecule that must be activated by ultraviolet light to form pre-vitamin D3. Recent studies connected the gene encoding for vitamin D (VDR) to the genetic control of bone mass and other diseases. As VDR SNPs have been associated with several disorders and diseases, it's important to investigate the allelic and genotypic distribution among populations. The aim of this study is to determine the frequency of rs731236 (Taq1) and rs2228570 (Fok1) variants in healthy Emirati individuals and compare their genotype and allele distribution with other populations. In this study 282 (female, 187; male, 95) unrelated healthy UAE nationals were involved. Two hundreds and eight two DNA samples been collected to genotype rs731236 (Taq1) and rs2228570 (Fok1) VDR SNPs. Our results indicate that the distribution of the alleles and genotypes of rs731236 (Taq1) and rs2228570 (Fok1) vary considerably in different populations. In the Emirati population the distribution of rs731236 (Taq1) and rs2228570 (Fok1) were AA 38%, AG 42%, GG 20% and AA 27%, AG 42%, GG 31% respectively. The Emirati population genotype and allele distribution of rs731236 (Taq1) and rs2228570 (Fok1) had no difference with Caucasians from USA and France. However, there was significant difference with Asian populations. PMID:26504744

  5. Leukocyte Telomere Length-Related rs621559 and rs398652 Genetic Variants Influence Risk of HBV-Related Hepatocellular Carcinoma

    PubMed Central

    Shi, Juan; Lu, Chao; Wei, Jinyu; Li, Lichao; Zhou, Changchun; Yuan, Qipeng; Zhou, Liqing; Yang, Ming

    2014-01-01

    Recent genome-wide association studies (GWAS) have identified eleven leukocyte telomere length (LTL)-related single nucleotide polymorphisms (SNPs). Since LTL has been associated with risk of many malignancies, LTL-related SNPs may contribute to cancer susceptibility. To test this hypothesis in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we genotyped these eleven LTL-related SNPs in a case-control set including 1186 HBV-related HCC cases, 508 chronic HBV carriers and 1308 healthy controls at the discovery stage. The associations of HCC risk with these SNPs were further confirmed in an independent case-control set. We found that 1p34.2 rs621559 and 14q21 rs398652 were significantly associated with HBV-related HCC risk (both P<0.005 after Bonferroni corrections). There was no significant difference of either rs621559 or rs398652 genotypes between chronic HBV carriers and healthy controls, demonstrating that the association was not due to predisposition to HBV infection. In the pooled analyses (1806 HBV-related HCC cases and 1954 controls), we observed a decreased HCC risk, 0.72-times, associated with the 1p34.2 rs621559 AA genotype compared to the GG genotype (P = 1.6×10−6). Additionally, there was an increased HCC risk, 1.27-fold, associated with the rs398652 GG genotype (P = 3.3×10−6). A statistical joint effect between the rs621559 GG and rs398652 GG genotypes may exist in elevating risk of HBV-related HCC. We show, for the first time, that rs398652 and rs621559 might be marker genetic variants for risk of HBV-related HCC in the Chinese population. PMID:25365256

  6. Frequency of rs731236 (Taql), rs2228570 (Fok1) of Vitamin-D Receptor (VDR) gene in Emirati healthy population.

    PubMed

    Osman, Enas; Al Anouti, Fatme; El Ghazali, Gehad; Haq, Afrozul; Mirgani, Rajaa; Al Safar, Habiba

    2015-12-01

    Vitamin D is getting more attention everyday due to its importance in maintaining bone and calcium homeostasis, cellular proliferation, differentiation and immune response. Vitamin D is derived from diet or elicited in the skin by the activation of 7-dehydrocholesterol, which is an inert molecule that must be activated by ultraviolet light to form pre-vitamin D3. Recent studies connected the gene encoding for vitamin D (VDR) to the genetic control of bone mass and other diseases. As VDR SNPs have been associated with several disorders and diseases, it's important to investigate the allelic and genotypic distribution among populations. The aim of this study is to determine the frequency of rs731236 (Taq1) and rs2228570 (Fok1) variants in healthy Emirati individuals and compare their genotype and allele distribution with other populations. In this study 282 (female, 187; male, 95) unrelated healthy UAE nationals were involved. Two hundreds and eight two DNA samples been collected to genotype rs731236 (Taq1) and rs2228570 (Fok1) VDR SNPs. Our results indicate that the distribution of the alleles and genotypes of rs731236 (Taq1) and rs2228570 (Fok1) vary considerably in different populations. In the Emirati population the distribution of rs731236 (Taq1) and rs2228570 (Fok1) were AA 38%, AG 42%, GG 20% and AA 27%, AG 42%, GG 31% respectively. The Emirati population genotype and allele distribution of rs731236 (Taq1) and rs2228570 (Fok1) had no difference with Caucasians from USA and France. However, there was significant difference with Asian populations.

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    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.

  8. Site-Selective Modification of Cellulose Nanocrystals with Isophorone Diisocyanate and Formation of Polyurethane-CNC Composites.

    PubMed

    Girouard, Natalie M; Xu, Shanhong; Schueneman, Gregory T; Shofner, Meisha L; Meredith, J Carson

    2016-01-20

    The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and isocyanate functionality. The chemical functionality of the modified CNCs was verified with ATR-FTIR analysis and elemental analysis. The selectivity for the secondary isocyanate group using dibutyl tin dilaurate (DBTDL) as the reaction catalyst was confirmed with (13)C NMR. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs. Polyurethane composites based on IPDI and a trifunctional polyether alcohol were synthesized using unmodified (um-CNC) and modified CNCs (m-CNC). The degree of nanoparticle dispersion was qualitatively assessed with polarized optical microscopy. It was found that the modification step facilitated superior nanoparticle dispersion compared to the um-CNCs, which resulted in increases in the tensile strength and work of fracture of over 200% compared to the neat matrix without degradation of elongation at break. PMID:26713564

  9. Einstein Observatory coronal temperatures of late-type stars

    NASA Technical Reports Server (NTRS)

    Schmitt, J. H. M. M.; Collura, A.; Sciortino, S.; Vaiana, G. S.; Harnden, F. R., Jr.

    1990-01-01

    The results are presented of a survey of the coronal temperatures of late-type stars using the Einstein Observatory IPC. The spectral analysis shows that the frequently found one- and two-temperature descriptions are mainly influenced by the SNR of the data and that models using continuous emission measure distributions can provide equally adequate and physically more meaningful and more plausible descriptions. Intrinsic differences in differential emission measure distributions are found for four groups of stars. M dwarfs generally show evidence for high-temperature gas in conjunction with lower-temperature material, while main-sequence stars of types F and G have the high-temperature component either absent or very weak. Very hot coronae without the lower-temperature component appearing in dwarf stars are evident in most of the giant stars studied. RS CVn systems show evidence for extremely hot coronae, sometimes with no accompanying lower-temperature material.

  10. Ultraprecision, high stiffness CNC grinding machines for ductile mode grinding of brittle materials

    NASA Astrophysics Data System (ADS)

    McKeown, Patrick A.; Carlisle, Keith; Shore, Paul; Read, R. F.

    1990-10-01

    Under certain controlled conditions it is now possible to machine brittle materials such as glasses and ceramics using single or multi-point diamond tools (grinding), so that material is removed by plastic flow, leaving crack-free surfaces. This process is called 'shear' or 'ductile' mode grinding. It represents a major breakthrough in modern manufacturing engineering since it promises to enable: - complex optical components, both transmission and reflecting to be generated by advanced CNC machines with very little (or even zero) subsequent polishing. - complex shaped components such as turbine blades, nozzle guide vanes, etc. to be finish machined after near net shape forming, to high precision in advanced ceramics such as silicon nitride, without inducing micro-cracking and thus lowering ultimate rupture strength and fatigue life. Ductile mode "damage free" grinding occurs when the volume of materials stressed by each grit of the grinding wheel is small enough to yield rather than exhibit brittle fracture, i.e. cracking. In practice, this means maintaining the undeformed chip thickness to below the ductile-brittle transition value; this varies from material to material but is generally in the order of 0.1 pm or 100 nm, (hence the term "nanogrinding" is sometimes used) . Thus the critical factors for operating successfully in the ductile regime are machine system accuracy and dynamic stiffness between each grit and the workpiece. In detail this means: (i) High precision 'truing' of the diamond grits, together with dressing of the wheel bond to ensure adequate ' openness'; (ii) Design and build of the grinding wheel spindle with very high dynamic stiffness; error motions, radial and axial, must be considerably less than 100 nfl. (iii) Design and build of the workpiece carriage motion system with very high dynamic stiffness; error motions, linear or rotary, must be well within 100 nm. (iv) Smooth, rumble-free, high-stiffness servo-drives controlling the motions

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

    PubMed Central

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

    2012-01-01

    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. PMID:22524152

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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

  14. Converting neutron stars into strange stars

    NASA Technical Reports Server (NTRS)

    Olinto, A. V.

    1991-01-01

    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.

  15. An open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and industrial CAM software.

    PubMed

    Lu, Li; Liu, Shusheng; Shi, Shenggen; Yang, Jianzhong

    2011-10-01

    China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture (CAM) technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design (CAD)/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system. PMID:22038364

  16. Association of Renalase SNPs rs2296545 and rs2576178 with the Risk of Hypertension: A Meta-Analysis

    PubMed Central

    Ma, Wang-Ge; Yan, Ding-Yi; Zheng, Wen-Ling; Chu, Chao; Guo, Tong-Shuai; Yuan, Zu-Yi; Mu, Jian-Jun

    2016-01-01

    Background/Aims Two renalase single nucleotide polymorphisms (SNPs) rs2296545 and rs2576178 have been reported to be associated with the susceptibility to hypertension (HT). Given the inconsistent results, we conducted a meta-analysis to assess the association between these two SNPs and the risk of HT. Methods Electronic databases were systematically searched to find relevant studies. Subgroup analysis was conducted according to the different concomitant diseases and ethnicities in the study population. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using fixed-effect or random-effect models. Results A total of six case–control studies on rs2296545 and six studies on rs2576178 were included. In the combined analysis, results showed a significant association between SNP rs2296545 and risk of HT in all genetic models (dominant model CG+CC/GG: OR = 1.43, 95% CI = 1.24–1.65; recessive model CC/CG+GG: OR = 1.36, 95% CI = 1.09–1.69; codominant model CC/GG: OR = 1.63, 95% CI = 1.20–2.20, CG/GG: OR = 1.30, 95% CI = 1.12–1.52; allelic model C/G: OR = 1.29, 95% CI = 1.10–1.51). In subgroup analysis, we observed a significant association between rs2296545 and risk of essential HT. Although we did not observe an association between rs2576178 polymorphism and HT in the combined analysis, an increased risk was observed in the essential HT patients versus healthy controls (subgroup 1) analysis under the dominant, recessive, and codominant genetic models. Conclusions Renalase gene rs2296545 polymorphism is significantly associated with increased risk of HT, whereas rs2576178 polymorphism may not be associated with the susceptibility to HT. PMID:27434211

  17. Exceptional Stars

    NASA Astrophysics Data System (ADS)

    Kulkarni, S. R.; Hansen, B.; van Kerkwijk, M.; Phinney, E. S.

    2005-12-01

    As part of our Interdisciplinary Scientist effort (PI, Kulkarni) for the Space Interferometry Mission (SIM) we proposed an investigation with SIM of a number of exceptional stars. With SIM we plan to observe dozens of nearby white dwarfs and search for planets surviving the evolution away from the main sequence as well as (newly formed) planets formed in the circumbinary disks of post-AGB binaries or as a result of white dwarf mergers. We propose to measure the proper motion of a sample of X-ray binaries and Be star binaries with the view of understanding the originof high latitude objects and inferring natal kicks and pre-supernova orbits. We plan to observe several compact object binaries to determine the mass of the compact star. Of particular importance is the proposed observation of SS 433 (for which we propose to use the spectrometer on SIM to measure the proper motion of the emission line clumps embedded in the relativistic jets). Separately we are investigating the issue of frame tie between SIM and the ecliptic frame (by observing binary millisecond pulsars with SIM; the position of these objects is very well determined by pulsar timing) and the degree to which highly precise visibility amplitude measurements can be inverted to infer binary parameters.

  18. What kind of animal is the "Three Rs"?

    PubMed

    Hobson-West, Pru

    2009-12-01

    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.

  19. Relationship Between Chronic Tinnitus and Glial Cell Line-Derived Neurotrophic Factor Gene rs3812047, rs1110149, and rs884344 Polymorphisms in a Turkish Population.

    PubMed

    Orenay-Boyacioglu, Seda; Coskunoglu, Aysun; Caki, Zerrin; Cam, Fethi Sirri

    2016-08-01

    Glial cell line-derived neurotrophic factor (GDNF) plays a key role in early development of central auditory pathway and the inner ear. However, the auditory pathway studies of GDNF gene polymorphisms are scarce in the literature, and the studies especially associated with tinnitus are limited. Our study aimed to identify whether GDNF gene polymorphisms play any roles in the pathophysiology of tinnitus by investigating the relationship between tinnitus and GDNF polymorphisms. A total of 52 patients with chronic tinnitus and ages ranging from 18 to 55 were admitted to the Ear-Nose-Throat outpatient clinic of Celal Bayar University Medical Faculty Hospital of Manisa, Turkey and constituted the study group. Another 42 patients of the same age range, without tinnitus symptoms and lacking any systemic disease, were also admitted to the clinic and formed the control group. The tympanometric, audiological, and psychoacoustic assessments of the subjects were performed. Deoxyribonucleic acid samples obtained using venous blood taken for routine inspections were used to investigate GDNF gene polymorphisms (rs884344, rs3812047, and rs1110149) by polymerase chain reaction-based restriction fragment length polymorphism method. No correlation could be detected between GDNF rs884344 and rs3812047 polymorphisms and subjects with tinnitus (p > 0.05). Heterozygosity was significantly lower for GDNF rs1110149 polymorphism in tinnitus subjects compared to the controls (p < 0.05). However, the allele frequencies for all 3 polymorphisms were not significantly different between tinnitus and control groups (p > 0.05). Failure to detect correlations between tinnitus and GDNF gene polymorphisms suggests this may be due to the fact that the GDNF gene has a variable expression pattern in different tissues and pathologies. Therefore, the study should be improved and its scope should be expanded by including a larger group of patients and different tissues to investigate the expression

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

    PubMed Central

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

    2014-01-01

    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. χ2 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

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

    NASA Technical Reports Server (NTRS)

    Clemens, Dan P.; Leah, Robert W.

    1989-01-01

    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.

  2. Optical flickering of the recurrent nova RS Ophiuchi: amplitude-flux relation

    NASA Astrophysics Data System (ADS)

    Zamanov, R.; Latev, G.; Boeva, S.; Sokoloski, J. L.; Stoyanov, K.; Bachev, R.; Spassov, B.; Nikolov, G.; Golev, V.; Ibryamov, S.

    2015-07-01

    We report observations of the flickering variability of the symbiotic recurrent nova RS Oph at quiescence in five bands (UBVRI). We find evidence of a correlation between the peak-to-peak flickering amplitude (ΔF) and the average flux of the hot component (Fav). The correlation is highly significant, with a correlation coefficient of 0.85 and a p-value of ˜10-20. Combining the data from all wavebands, we find a dependence of the type Δ F ∝ F_{av}^k, with power-law index k = 1.02 ± 0.04 for the UBVRI flickering of RS Oph. Thus, the relationship between the amplitude of variability and the average flux of the hot component is consistent with linearity. The rms amplitude of flickering is on average 8 per cent (±2 per cent) of Fav. The detected correlation is similar to that found in accreting black holes/neutron stars and cataclysmic variables. The possible reasons are briefly discussed. The data are available upon request from the authors.

  3. A Vanishing Star Revisited

    NASA Astrophysics Data System (ADS)

    1999-07-01

    system NN Ser is now in an evolutionary stage that is referred to as the pre-cataclysmic phase. It will be followed by the cataclysmic phase , during which a gas stream will flow from the larger star to the smaller one. This phenomenon is characterized by frequent and abrupt increase in brightness. While many stars are known that are now in that unstable phase, only a few stars have ever been found to be in the preceding, transitory phase. Of these, NN Ser is the only one that has such a deep eclipse and for which it has now become possible to determine quite well the properties of the two components. NN Ser thus represents a most welcome example of a "missing link" in the theory of stellar evolution. It is therefore of great interest to perform further observations of such a rare object. They will include attempts to obtain more spectra to define the spectral type of the cool star very accurately. This will allow a critical check of current theories of atmospheres and evolutionary computations for the smallest and lightest stars. But for now, Reinhold Häfner looks forward to further nights at Paranal with the ESO astronomers there. "We worked together in a wonderful way during these demanding observations", he said, "and without their great support all of this would have been next to impossible!" Notes [1] These observations were carried out during "guaranteed observing time", allocated to the three German institutes that built the FORS instrument. More details about this instrument and related issues are available in ESO Press Release 14/98. [2] Astronomers designate variable stars according to the constellation in which they are seen in the sky and the order in which they are recognized as having variable brightness. For historical reasons, the first variable star in a given constellation (that is not already known by a greek letter, e.g. "Delta Cephei") is designated as "R" (e.g. "R Coronae Borealis"), the second as "S", etc. until "Z". Then follow "RR", "RS

  4. The optimal algorithm for Multi-source RS image fusion.

    PubMed

    Fu, Wei; Huang, Shui-Guang; Li, Zeng-Shun; Shen, Hao; Li, Jun-Shuai; Wang, Peng-Yuan

    2016-01-01

    In order to solve the issue which the fusion rules cannot be self-adaptively adjusted by using available fusion methods according to the subsequent processing requirements of Remote Sensing (RS) image, this paper puts forward GSDA (genetic-iterative self-organizing data analysis algorithm) by integrating the merit of genetic arithmetic together with the advantage of iterative self-organizing data analysis algorithm for multi-source RS image fusion. The proposed algorithm considers the wavelet transform of the translation invariance as the model operator, also regards the contrast pyramid conversion as the observed operator. The algorithm then designs the objective function by taking use of the weighted sum of evaluation indices, and optimizes the objective function by employing GSDA so as to get a higher resolution of RS image. As discussed above, the bullet points of the text are summarized as follows.•The contribution proposes the iterative self-organizing data analysis algorithm for multi-source RS image fusion.•This article presents GSDA algorithm for the self-adaptively adjustment of the fusion rules.•This text comes up with the model operator and the observed operator as the fusion scheme of RS image based on GSDA. The proposed algorithm opens up a novel algorithmic pathway for multi-source RS image fusion by means of GSDA. PMID:27408827

  5. The optimal algorithm for Multi-source RS image fusion.

    PubMed

    Fu, Wei; Huang, Shui-Guang; Li, Zeng-Shun; Shen, Hao; Li, Jun-Shuai; Wang, Peng-Yuan

    2016-01-01

    In order to solve the issue which the fusion rules cannot be self-adaptively adjusted by using available fusion methods according to the subsequent processing requirements of Remote Sensing (RS) image, this paper puts forward GSDA (genetic-iterative self-organizing data analysis algorithm) by integrating the merit of genetic arithmetic together with the advantage of iterative self-organizing data analysis algorithm for multi-source RS image fusion. The proposed algorithm considers the wavelet transform of the translation invariance as the model operator, also regards the contrast pyramid conversion as the observed operator. The algorithm then designs the objective function by taking use of the weighted sum of evaluation indices, and optimizes the objective function by employing GSDA so as to get a higher resolution of RS image. As discussed above, the bullet points of the text are summarized as follows.•The contribution proposes the iterative self-organizing data analysis algorithm for multi-source RS image fusion.•This article presents GSDA algorithm for the self-adaptively adjustment of the fusion rules.•This text comes up with the model operator and the observed operator as the fusion scheme of RS image based on GSDA. The proposed algorithm opens up a novel algorithmic pathway for multi-source RS image fusion by means of GSDA.

  6. Association between polymorphisms of prokineticin receptor (PKR1 rs4627609 and PKR2 rs6053283) and recurrent pregnancy loss*

    PubMed Central

    Cao, Yun-lei; Zhang, Zhao-feng; Wang, Jian; Miao, Mao-hua; Xu, Jian-hua; Shen, Yue-ping; Chen, Ai-min; Du, Jing; Yuan, Wei

    2016-01-01

    Recurrent pregnancy loss (RPL) is a condition with complex etiologies, to which both genetic and environmental factors may contribute. During the last decade, studies indicated that the expression patterns of the prokineticin receptor (PKR1 and PKR2) are closely related to early pregnancy. However, there are few studies on the role of PKR1 and PKR2 in RPL. In this study, we purpose to investigate the association between polymorphisms of the prokineticin receptor (PKR1 rs4627609 and PKR2 rs6053283) and RPL on a group of 93 RPL cases and 169 healthy controls. Genotyping of the single nucleotide polymorphisms (SNPs) was performed using a Sequenom MassARRAY iPLEX system. The results revealed a significant association between PKR2 rs6053283 polymorphism and RPL (P=0.003), whereas no association was observed between PKR1 rs4627609 polymorphism and RPL (P=0.929) in the Chinese Han population. PMID:26984842

  7. Binary stars.

    PubMed

    Paczynacuteski, B

    1984-07-20

    Most stars in the solar neighborhood are either double or multiple systems. They provide a unique opportunity to measure stellar masses and radii and to study many interesting and important phenomena. The best candidates for black holes are compact massive components of two x-ray binaries: Cygnus X-1 and LMC X-3. The binary radio pulsar PSR 1913 + 16 provides the best available evidence for gravitational radiation. Accretion disks and jets observed in close binaries offer a very good testing ground for models of active galactic nuclei and quasars.

  8. Binary stars.

    PubMed

    Paczynacuteski, B

    1984-07-20

    Most stars in the solar neighborhood are either double or multiple systems. They provide a unique opportunity to measure stellar masses and radii and to study many interesting and important phenomena. The best candidates for black holes are compact massive components of two x-ray binaries: Cygnus X-1 and LMC X-3. The binary radio pulsar PSR 1913 + 16 provides the best available evidence for gravitational radiation. Accretion disks and jets observed in close binaries offer a very good testing ground for models of active galactic nuclei and quasars. PMID:17749544

  9. Computer numerical control (CNC) lithography: light-motion synchronized UV-LED lithography for 3D microfabrication

    NASA Astrophysics Data System (ADS)

    Kim, Jungkwun; Yoon, Yong-Kyu; Allen, Mark G.

    2016-03-01

    This paper presents a computer-numerical-controlled ultraviolet light-emitting diode (CNC UV-LED) lithography scheme for three-dimensional (3D) microfabrication. The CNC lithography scheme utilizes sequential multi-angled UV light exposures along with a synchronized switchable UV light source to create arbitrary 3D light traces, which are transferred into the photosensitive resist. The system comprises a switchable, movable UV-LED array as a light source, a motorized tilt-rotational sample holder, and a computer-control unit. System operation is such that the tilt-rotational sample holder moves in a pre-programmed routine, and the UV-LED is illuminated only at desired positions of the sample holder during the desired time period, enabling the formation of complex 3D microstructures. This facilitates easy fabrication of complex 3D structures, which otherwise would have required multiple manual exposure steps as in the previous multidirectional 3D UV lithography approach. Since it is batch processed, processing time is far less than that of the 3D printing approach at the expense of some reduction in the degree of achievable 3D structure complexity. In order to produce uniform light intensity from the arrayed LED light source, the UV-LED array stage has been kept rotating during exposure. UV-LED 3D fabrication capability was demonstrated through a plurality of complex structures such as V-shaped micropillars, micropanels, a micro-‘hi’ structure, a micro-‘cat’s claw,’ a micro-‘horn,’ a micro-‘calla lily,’ a micro-‘cowboy’s hat,’ and a micro-‘table napkin’ array.

  10. "New turns from old STaRs": enhancing the capabilities of forensic short tandem repeat analysis.

    PubMed

    Phillips, Christopher; Gelabert-Besada, Miguel; Fernandez-Formoso, Luis; García-Magariños, Manuel; Santos, Carla; Fondevila, Manuel; Ballard, David; Syndercombe Court, Denise; Carracedo, Angel; Lareu, Maria Victoria

    2014-11-01

    The field of research and development of forensic STR genotyping remains active, innovative, and focused on continuous improvements. A series of recent developments including the introduction of a sixth dye have brought expanded STR multiplex sizes while maintaining sensitivity to typical forensic DNA. New supplementary kits complimenting the core STRs have also helped improve analysis of challenging identification cases such as distant pairwise relationships in deficient pedigrees. This article gives an overview of several recent key developments in forensic STR analysis: availability of expanded core STR kits and supplementary STRs, short-amplicon mini-STRs offering practical options for highly degraded DNA, Y-STR enhancements made from the identification of rapidly mutating loci, and enhanced analysis of genetic ancestry by analyzing 32-STR profiles with a Bayesian forensic classifier originally developed for SNP population data. As well as providing scope for genotyping larger numbers of STRs optimized for forensic applications, the launch of compact next-generation sequencing systems provides considerable potential for genotyping the sizeable proportion of nucleotide variation existing in forensic STRs, which currently escapes detection with CE.

  11. "New turns from old STaRs": enhancing the capabilities of forensic short tandem repeat analysis.

    PubMed

    Phillips, Christopher; Gelabert-Besada, Miguel; Fernandez-Formoso, Luis; García-Magariños, Manuel; Santos, Carla; Fondevila, Manuel; Ballard, David; Syndercombe Court, Denise; Carracedo, Angel; Lareu, Maria Victoria

    2014-11-01

    The field of research and development of forensic STR genotyping remains active, innovative, and focused on continuous improvements. A series of recent developments including the introduction of a sixth dye have brought expanded STR multiplex sizes while maintaining sensitivity to typical forensic DNA. New supplementary kits complimenting the core STRs have also helped improve analysis of challenging identification cases such as distant pairwise relationships in deficient pedigrees. This article gives an overview of several recent key developments in forensic STR analysis: availability of expanded core STR kits and supplementary STRs, short-amplicon mini-STRs offering practical options for highly degraded DNA, Y-STR enhancements made from the identification of rapidly mutating loci, and enhanced analysis of genetic ancestry by analyzing 32-STR profiles with a Bayesian forensic classifier originally developed for SNP population data. As well as providing scope for genotyping larger numbers of STRs optimized for forensic applications, the launch of compact next-generation sequencing systems provides considerable potential for genotyping the sizeable proportion of nucleotide variation existing in forensic STRs, which currently escapes detection with CE. PMID:24888494

  12. Radii, masses, and ages of 18 bright stars using interferometry and new estimations of exoplanetary parameters

    NASA Astrophysics Data System (ADS)

    Ligi, R.; Creevey, O.; Mourard, D.; Crida, A.; Lagrange, A.-M.; Nardetto, N.; Perraut, K.; Schultheis, M.; Tallon-Bosc, I.; ten Brummelaar, T.

    2016-02-01

    Context. Accurate stellar parameters are needed in numerous domains of astrophysics. The position of stars on the Hertzsprung-Russell diagram is an important indication of their structure and evolution, and it helps improve stellar models. Furthermore, the age and mass of stars hosting planets are required elements for studying exoplanetary systems. Aims: We aim at determining accurate parameters of a set of 18 bright exoplanet host and potential host stars from interferometric measurements, photometry, and stellar models. Methods: Using the VEGA/CHARA interferometer operating in the visible domain, we measured the angular diameters of 18 stars, ten of which host exoplanets. We combined them with their distances to estimate their radii. We used photometry to derive their bolometric flux and, then, their effective temperature and luminosity to place them on the H-R diagram. We then used the PARSEC models to derive their best fit ages and masses, with error bars derived from Monte Carlo calculations. Results: Our interferometric measurements lead to an average of 1.9% uncertainty on angular diameters and 3% on stellar radii. There is good agreement between measured and indirect estimations of angular diameters (either from SED fitting or from surface brightness relations) for main sequence (MS) stars, but not as good for more evolved stars. For each star, we provide a likelihood map in the mass-age plane; typically, two distinct sets of solutions appear (an old and a young age). The errors on the ages and masses that we provide account for the metallicity uncertainties, which are often neglected by other works. From measurements of its radius and density, we also provide the mass of 55 Cnc independently of models. From the stellar masses, we provide new estimates of semi-major axes and minimum masses of exoplanets with reliable uncertainties. We also derive the radius, density, and mass of 55 Cnc e, a super-Earth that transits its stellar host. Our exoplanetary

  13. Genetic Association of CHAT rs3810950 and rs2177369 Polymorphisms with the Risk of Alzheimer's Disease: A Meta-Analysis.

    PubMed

    Liu, Yong; Chen, Qicong; Liu, Xu; Dou, Mengmeng; Li, Silu; Zhou, Jiahui; Liu, Hong; Wu, Yongfu; Huang, Zunnan

    2016-01-01

    Choline acetyltransferase (CHAT) rs3810950 and rs2177369 polymorphisms have been implicated in susceptibility to Alzheimer's disease (AD). Due to the inconsistent results from previous studies, a meta-analysis was performed to estimate the association between these polymorphisms and AD risk more precisely. Pooled results of our meta-analysis indicated CHAT rs2177369 polymorphism was correlated with decreasing AD risk in one of five genetic models (dominant: OR = 0.77, 95% CI: 0.62-0.96), while rs3810950 mutant was associated with AD development in three models (allelic: OR = 1.18, 95% CI: 1.01-1.37, homozygous: OR = 1.63, 95% CI: 1.09-2.42, and recessive: OR = 1.65, 95% CI: 1.20-2.26). In subgroup analysis by ethnicity, the association between CHAT rs3810950 polymorphism and AD risk was just found in the recessive model (OR = 1.47, 95% CI: 1.05-2.07) among Caucasians, while four genetic models (allelic: OR = 1.23, 95% CI: 1.01-1.48; homozygous: OR = 2.24, 95% CI: 1.48-3.39; dominant: OR = 1.21, 95% CI: 1.06-1.40; and recessive: OR = 2.18, 95% CI: 1.45-3.29) assumed this association in Asians. In conclusion, our meta-analysis indicated CHAT rs2177369 polymorphism might play a protective role in AD, while rs3810950 variant was a risk factor for AD but its single heterozygous mutations might not influence susceptibility to AD. PMID:27597977

  14. Genetic Association of CHAT rs3810950 and rs2177369 Polymorphisms with the Risk of Alzheimer's Disease: A Meta-Analysis

    PubMed Central

    Liu, Yong; Chen, Qicong; Liu, Xu; Dou, Mengmeng; Li, Silu; Zhou, Jiahui; Liu, Hong

    2016-01-01

    Choline acetyltransferase (CHAT) rs3810950 and rs2177369 polymorphisms have been implicated in susceptibility to Alzheimer's disease (AD). Due to the inconsistent results from previous studies, a meta-analysis was performed to estimate the association between these polymorphisms and AD risk more precisely. Pooled results of our meta-analysis indicated CHAT rs2177369 polymorphism was correlated with decreasing AD risk in one of five genetic models (dominant: OR = 0.77, 95% CI: 0.62–0.96), while rs3810950 mutant was associated with AD development in three models (allelic: OR = 1.18, 95% CI: 1.01–1.37, homozygous: OR = 1.63, 95% CI: 1.09–2.42, and recessive: OR = 1.65, 95% CI: 1.20–2.26). In subgroup analysis by ethnicity, the association between CHAT rs3810950 polymorphism and AD risk was just found in the recessive model (OR = 1.47, 95% CI: 1.05–2.07) among Caucasians, while four genetic models (allelic: OR = 1.23, 95% CI: 1.01–1.48; homozygous: OR = 2.24, 95% CI: 1.48–3.39; dominant: OR = 1.21, 95% CI: 1.06–1.40; and recessive: OR = 2.18, 95% CI: 1.45–3.29) assumed this association in Asians. In conclusion, our meta-analysis indicated CHAT rs2177369 polymorphism might play a protective role in AD, while rs3810950 variant was a risk factor for AD but its single heterozygous mutations might not influence susceptibility to AD. PMID:27597977

  15. Genetic Association of CHAT rs3810950 and rs2177369 Polymorphisms with the Risk of Alzheimer's Disease: A Meta-Analysis

    PubMed Central

    Liu, Yong; Chen, Qicong; Liu, Xu; Dou, Mengmeng; Li, Silu; Zhou, Jiahui; Liu, Hong

    2016-01-01

    Choline acetyltransferase (CHAT) rs3810950 and rs2177369 polymorphisms have been implicated in susceptibility to Alzheimer's disease (AD). Due to the inconsistent results from previous studies, a meta-analysis was performed to estimate the association between these polymorphisms and AD risk more precisely. Pooled results of our meta-analysis indicated CHAT rs2177369 polymorphism was correlated with decreasing AD risk in one of five genetic models (dominant: OR = 0.77, 95% CI: 0.62–0.96), while rs3810950 mutant was associated with AD development in three models (allelic: OR = 1.18, 95% CI: 1.01–1.37, homozygous: OR = 1.63, 95% CI: 1.09–2.42, and recessive: OR = 1.65, 95% CI: 1.20–2.26). In subgroup analysis by ethnicity, the association between CHAT rs3810950 polymorphism and AD risk was just found in the recessive model (OR = 1.47, 95% CI: 1.05–2.07) among Caucasians, while four genetic models (allelic: OR = 1.23, 95% CI: 1.01–1.48; homozygous: OR = 2.24, 95% CI: 1.48–3.39; dominant: OR = 1.21, 95% CI: 1.06–1.40; and recessive: OR = 2.18, 95% CI: 1.45–3.29) assumed this association in Asians. In conclusion, our meta-analysis indicated CHAT rs2177369 polymorphism might play a protective role in AD, while rs3810950 variant was a risk factor for AD but its single heterozygous mutations might not influence susceptibility to AD.

  16. Physical parameters of seven field RR Lyrae Stars in bootes

    NASA Astrophysics Data System (ADS)

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

    2009-10-01

    Strömgren uvby-β 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 Δ 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.

  17. A Spectroscopic Analysis of Extended Matter in Eclipsing RS CVN Binaries.

    NASA Astrophysics Data System (ADS)

    Hall, Jeffrey Clifton

    1991-02-01

    I have conducted a survey of a number of eclipsing RS CVn binaries to search for the presence of extended matter associated with the component stars. Previous evidence indicates that this extended matter is more like solar quiescent prominences than other structures such as plage; as such, it is most identifiable when viewed off the stellar limb. In eclipsing systems, the matter can be seen indirectly as it obscures a portion of the eclipsed star's limb. My survey has identified some systems in which this is the case. Parameterization of the physical extent of the extended matter is a geometrical problem wherein the amount of obscuration caused by the prominence depends on its size and orientation as well as its optical depth in the line of interest. I have done this using a Simplex algorithm which I have developed and specifically tailored to the problem at hand. I classify the extended components I have seen and discuss their effect on the spectral profiles. Other spectral diagnostics provide clues as to their origin, and I discuss this in the context of the present "solar analogy" paradigm.

  18. The enigmatic star EZ Pegasi - A mystery solved?

    NASA Technical Reports Server (NTRS)

    Howell, S. B.; Bopp, B. W.

    1985-01-01

    EZ Peg, a ninth-magnitude G star that has been classified by various authors as an irregular variable, a U Gem system, and a contact binary, is shown to have all the spectroscopic and photometric characteristics of an active-chromosphere RS CVn binary. It is suggested that the reported outburst of 1943, when the spectrum appeared to be that of a B star, never occurred. The strong Ca II H and K reversals, viewed with low spectral resolution, caused the photospheric Ca II absorption to appear abnormally weak, mimicking a much earlier spectral type.

  19. Physical parameter determination of seven RR Lyrae stars in Bootes

    NASA Astrophysics Data System (ADS)

    Peña, J. H.; Arellano, A.; Sareyan, J. P.; Peña, R.; Alvarez, M.

    2007-06-01

    uvbyβ photoelectric photometry of the RR Lyrae stars AE, RS, ST, TV, TW, UU, and XX Bootis has been acquired in order to determine the physical parameters of the stars. We used the correlation between the Fourier parameters derived from the light curves and the physical parameters such as the absolute magnitude M_v, intrinsic colour (B-V)_0 and metal abundance [Fe/H]. Once reddening has been determined, unreddened indices are obtained and T_{eff} and log g followed along the cycle, using a comparison with the theoretical models given for our determined metallicity.

  20. Amyloid arthropathy revealed by RS3PE syndrome.

    PubMed

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

    2000-01-01

    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.

  1. Binarity and multiperiodicity in high-amplitude delta Scuti stars .

    NASA Astrophysics Data System (ADS)

    Derekas, A.; Kiss, L. L.; Csák, B.; Griffin, J.; Lindström, C.; Mészáros, Sz.; Székely, P.; Ashley, M. C. B.; Bedding, T. R.

    We present our first results for a sample of southern high-amplitude delta Scuti stars (HADS), based on a spectrophotometric survey started in 2003. For CY Aqr and AD CMi, we found very stable light and radial velocity (RV) curves; we confirmed the double-mode nature of ZZ Mic, BQ Ind and RY Lep. Finally, we detected gamma -velocity changes in RS Gru and RY Lep.

  2. Activity-driven structure variations as a cause of period changes in RS Canis Venaticorum-like systems

    NASA Technical Reports Server (NTRS)

    Van Buren, D.; Young, A.

    1985-01-01

    Magnetic activity cycles of a convective star in a close binary system may lead to orbit period changes through tidal spin-orbit coupling. An increase in the mean magnetic field throughout the convection zone provides an additional pressure support and increases the star's moment of inertia. In order for the system to conserve angular momentum instantaneously, the convective star must reduce its rotation rate. When this happens, the system is no longer synchronous; in particular, the equilibrium tide now suffers a phase lag. A tidal torque must act, transferring angular momentum from the star's rotation to the orbit, lengthening the period. When the field decays, these events reverse and the period shortens. Observed period changes in RS CVn-like systems are of the order delta p/p = 10 to the -6th, implying variations in the mean field strength at the base of the convection zone of approximately 1000 G over time scales of 10-30 yr. It is predicted that the strength of magnetic activity indicators will track orbital period changes in a given system: the period will be largest during the active portion of the magnetic cycle and smallest during the quiescent part.

  3. Polymorphisms rs12998 and rs5780218 in KiSS1 Suppressor Metastasis Gene in Mexican Patients with Breast Cancer

    PubMed Central

    Cruz Quevedo, Edhit Guadalupe; Mimendi Aguilar, Gabriela Monserrat; Juárez Aguilar, Luis Anselmo; Gutierrez Rubio, Susan Andrea; Flores Martínez, Silvia Esperanza; Dávalos Rodríguez, Ingrid Patricia; Sánchez Corona, José; Torres Morán, Martha Isabel; Rosales Gómez, Roberto Carlos; Morán Moguel, María Cristina

    2015-01-01

    Aims. KiSS1 is a metastasis suppressor gene associated with inhibition of cellular chemotaxis and invasion attenuating the metastasis in melanoma and breast cancer cell lines. Along the KiSS-1 gene at least 294 SNPs have been described; however the association of these polymorphisms as genetic markers for metastasis in breast cancer studies has not been investigated. Here we describe two simple PCR-RFLPs protocols to identify the rs5780218 (9DelT) and the rs12998 (E20K) KiSS1 polymorphisms and the allelic, genotypic, and haplotypic frequencies in Mexican general population (GP) and patients with benign breast disease (BBD) or breast cancer (BC). Results. The rs5780218 polymorphism was individually associated with breast cancer (P = 0.0332) and the rs12998 polymorphism shows statistically significant differences when GP versus case (BC and BBD) groups were compared (P < 0.0001). The H1 Haplotype (G/-) occurred more frequently in BC group (0.4256) whereas H2 haplotype (G/T) was the most prevalent in BBD group (0.4674). Conclusions. Our data indicated that the rs5780218 polymorphism individually confers susceptibility for development of breast cancer in Mexican population and a possible role as a genetic marker in breast cancer metastasis for H1 haplotype (Wt/variant) in KiSS1 gene must be analyzed in other populations. PMID:25810563

  4. O stars and Wolf-Rayet stars

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  5. MMP-9 gene polymorphisms (rs3918242, rs3918254 and rs4810482) and the risk of psoriasis vulgaris: No evidence for associations in a Chinese Han population.

    PubMed

    Liang, Jingyao; Zhao, Tian; Yang, Juan; Li, Wei; Zhang, Fang; Zhang, Sanquan; Huang, Zhenming; Lin, Rihua; Zhang, Xibao

    2015-12-01

    Several previous studies including one of them co-authored by our group have revealed that serum and psoriatic plaque expression of matrix metalloproteinase-9 (MMP-9) was significantly upregulated in psoriasis. The aim of this study was to investigate the association of three single nucleotide polymorphisms (SNPs) and haplotypes of MMP-9 (rs3918242, rs3918254 and rs4810482) with psoriasis vulgaris in a Chinese Han population. The serum levels of MMP-9 in 245 psoriasis vulgaris cases and 256 healthy controls were assessed using ELSA kits, and the three SNPs were genotyped using polymerase chain reaction-ligation detection reaction (PCR-LDR) method. Four haplotypes based on the three SNPs were also analyzed. Our study showed that the serum MMP-9 levels in patients with psoriasis vulgaris were significantly higher than that in controls (P<0.05). However, the three SNPs were not significantly associated with psoriasis vulgaris susceptibility (all P>0.05). Similar results were found in further subgroup analysis based on gender, age of onset, family history, and serum MMP-9 levels, except that a protective effect of psoriasis vulgaris was detected among female subjects with the CT genotype of rs3918254 (OR=0.47, 95% CI=0.23-0.96, P=0.038), but this association did not survive after Bonferroni correction (P(adj)=0.076). The haplotype analysis also failed to show any association with psoriasis vulgaris. We found no evidence for the association between the MMP-9 polymorphisms and psoriasis vulgaris susceptibility in a Chinese Han population.

  6. Lifestyles of the Stars.

    ERIC Educational Resources Information Center

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

  7. Egyptian "Star Clocks"

    NASA Astrophysics Data System (ADS)

    Symons, Sarah

    Diagonal, transit, and Ramesside star clocks are tables of astronomical information occasionally found in ancient Egyptian temples, tombs, and papyri. The tables represent the motions of selected stars (decans and hour stars) throughout the Egyptian civil year. Analysis of star clocks leads to greater understanding of ancient Egyptian constellations, ritual astronomical activities, observational practices, and pharaonic chronology.

  8. The CARD9 Polymorphisms rs4077515, rs10870077 and rs10781499 Are Uncoupled from Susceptibility to and Severity of Pulmonary Tuberculosis

    PubMed Central

    Iannaconne, Marco; McEwen, Gayle; Ciontea, Marius Sorin; Olaru, Marian; Capparelli, Rosanna; Ioana, Mihai; Kaufmann, Stefan H. E.; Dorhoi, Anca

    2016-01-01

    Genetic variants in the CARD9 gene predispose to inflammatory disorders and chronic infectious diseases. Tuberculosis (TB), a chronic infectious disease affecting the lung, is lethal in Card9-deficient mice. We hypothesized that polymorphisms in the CARD9 gene influence TB progression and disease-associated lung damage in humans. We tested genotype distributions of the CARD9 polymorphisms rs4077515, rs10781499 and rs10870077 in TB patients and healthy subjects in a Caucasian cohort. SNPs were in linkage disequilibrium and none of the haplotypes was significantly enriched in the TB group. We determined total and differential leukocyte count, erythrocyte sedimentation rate and plasma abundance of cytokines and chemokines as markers for systemic inflammation and scored chest X-rays to assess lung involvement in TB subjects. Most disease parameters segregated independently of the CARD9 haplotypes. In contrast to multifactorial chronic inflammation, selected genetic variants in the CARD9 gene leave host responses apparently unaffected in TB, at least in the population analyzed here. PMID:27684065

  9. Line profile asymmetries in chromospherically active stars

    NASA Technical Reports Server (NTRS)

    Dempsey, Robert C.; Bopp, Bernard W.; Strassmeier, Klaus G.; Granados, Arno F.; Henry, Gregory W.; Hall, Douglas S.

    1992-01-01

    A powerful, new probe of chromospheric activity, cross-correlation, has been developed and applied to a variety of stars. In this particular application, an entire CCD spectrum of an active star is correlated with the spectrum of a narrow-line, inactive star of similar spectral type and luminosity class. Using a number of strong lines in this manner enables the detection of absorption profile asymmetries at moderate resolution (lambda/Delta lambda about 40,000) and S/N 150:1. This technique has been applied to 14 systems mostly RS CVn's, with 10 not greater than nu sin i not greater than 50 km/s and P not less than 7 d. Distortions were detected for the first time in five systems: Sigma Gem, IM Peg, GX Lib, UV Crb, and Zeta And. Detailed modeling, incorporating both spectral line profiles and broad-band photometry, is applied to Sigma Gem. Profile asymmetries for this star are fitted by two high-latitude spots covering 5 percent of the stellar surface. The derived spot temperature of 3400 K is lower than found in previous studies. In addition, two well-known systems have been studied: HD 199178 and V711 Tau. Polar spots are found on both.

  10. Cytochrome P450 CYP6DA2 regulated by cap 'n'collar isoform C (CncC) is associated with gossypol tolerance in Aphis gossypii Glover.

    PubMed

    Peng, T; Pan, Y; Gao, X; Xi, J; Zhang, L; Yang, C; Bi, R; Yang, S; Xin, X; Shang, Q

    2016-08-01

    Cotton plants accumulate phytotoxins, such as gossypol and related sesquiterpene aldehydes, to resist insect herbivores. The survival of insects exposed to toxic secondary metabolites depends on the detoxification metabolism mediated by limited groups of cytochrome P450. Gossypol has an antibiotic effect on Aphis gossypii, and as the concentrations of gossypol were increased in the present study, the mortality of cotton aphids increased from 4 to 28%. The fecundity of the cotton aphids exposed to gossypol was also significantly reduced compared with the control. The transcriptional levels of CYP6DA2 in cotton aphids were significantly induced when exposed to gossypol, and knockdown of the CYP6DA2 transcripts by RNA interference (RNAi) significantly increased the toxicity of gossypol to cotton aphids. To further understand the gossypol regulatory cascade, the 5'-flanking promoter sequences of CYP6DA2 were isolated with a genome walker, and the promoter was very active and was inducible by gossypol. Co-transfection of the cap 'n' collar isoform C (CncC) and CYP6DA2 promoters dramatically increased the expression of CYP6DA2, and suppression of the CncC transcripts by RNAi significantly decreased the expression levels of CYP6DA2, and significantly increased the toxicity of gossypol to cotton aphids. Thus, the transcriptional regulation of CYP6DA2 involved the transcriptional factor CncC. PMID:27005728

  11. Neutron Stars and NuSTAR

    NASA Astrophysics Data System (ADS)

    Bhalerao, Varun

    2012-05-01

    My thesis centers around the study of neutron stars, especially those in massive binary systems. To this end, it has two distinct components: the observational study of neutron stars in massive binaries with a goal of measuring neutron star masses and participation in NuSTAR, the first imaging hard X-ray mission, one that is extremely well suited to the study of massive binaries and compact objects in our Galaxy. The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing high energy X-ray telescope to orbit. NuSTAR has an order-of-magnitude better angular resolution and has two orders of magnitude higher sensitivity than any currently orbiting hard X-ray telescope. I worked to develop, calibrate, and test CdZnTe detectors for NuSTAR. I describe the CdZnTe detectors in comprehensive detail here - from readout procedures to data analysis. Detailed calibration of detectors is necessary for analyzing astrophysical source data obtained by the NuSTAR. I discuss the design and implementation of an automated setup for calibrating flight detectors, followed by calibration procedures and results. Neutron stars are an excellent probe of fundamental physics. The maximum mass of a neutron star can put stringent constraints on the equation of state of matter at extreme pressures and densities. From an astrophysical perspective, there are several open questions in our understanding of neutron stars. What are the birth masses of neutron stars? How do they change in binary evolution? Are there multiple mechanisms for the formation of neutron stars? Measuring masses of neutron stars helps answer these questions. Neutron stars in high-mass X-ray binaries have masses close to their birth mass, providing an opportunity to disentangle the role of "nature" and "nurture" in the observed mass distributions. In 2006, masses had been measured for only six such objects, but this small sample showed the greatest diversity in masses

  12. Work in Progress: The Seven Rs of Team Building

    ERIC Educational Resources Information Center

    Brunelli, Jean; Schneider, Elaine Fogel

    2004-01-01

    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…

  13. Novel optoelectronic RS flipflop based on optically coupled inverters

    NASA Astrophysics Data System (ADS)

    Chino, T.; Matsuda, K.; Adachi, H.; Shibata, J.

    1992-03-01

    An optoelectronic RS flipflop emitting differential output has been proposed and demonstrated. It consists of two optical inverters. Optical interconnections are used to couple these inverters. Stable operation for the variation of bias voltage is demonstrated, which exhibits the possibility for 2-dimensional integration.

  14. The Link Between RS Ophiuchi and Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Mohamed, S.; Booth, R.; Podsiadlowski, Ph.

    2013-01-01

    RS Ophiuchi (RS Oph) is a symbiotic nova system consisting of a red giant and an accreting white dwarf (WD) which undergoes thermonuclear outbursts every 10-20 years. The WD is thought to be close to the Chandrasekhar mass making the system a likely Type Ia supernova (SN Ia) candidate. In recent years, the RS Oph-SN Ia connection has been further strengthened by time-varying circumstellar (CSM) absorption lines observed in high-resolution spectra of both systems. In this paper, we present 3D hydrodynamic simulations of the RS Oph system and preliminary post-processing results for the CSM absorption and hydrogen recombination lines. We find good agreement between the highly-structured, bipolar geometry in our models and the observed morphology. The geometry also naturally explains both the low velocity, narrow absorption and broad emission lines seen in SN 2006X and PTF 11kx. However, we find longer recombination timescales, larger velocity widths and weaker lines suggesting that the shells may be thinner and denser than those in our simulations.

  15. An H-alpha survey of southern hemisphere active chromosphere stars

    NASA Technical Reports Server (NTRS)

    Bopp, B. W.; Hearnshaw, J. B.

    1983-01-01

    Because of the variety of extraordinary phenomena exhibited by active chromosphere objects, discovery of new, bright surface-active stars is of considerable importance. Ca II emission is a well-known signature of chromospheric activity, serving even as one of the points of definition of the class of RS CVn binary stars. In connection with the present investigation, spectroscopic observations of 27 Ca II emission stars have been conducted. The observations make it possible to identify unambiguously the most chromospherically active stars in the sample. By observing the H-alpha line, rather than H and K, it is possible to distinguish nine of these stars which are likely to be observational targets as interesting as the extremely surface active objects V711 Tau or FK Com. Of the 27 stars surveyed, two (HD 86005, HD 204128) showed H-alpha as an emission feature above continuum, with estimated equivalent width 1-2 A.

  16. The Cambridge Double Star Atlas

    NASA Astrophysics Data System (ADS)

    MacEvoy, Bruce; Tirion, Wil

    2015-12-01

    Preface; What are double stars?; The binary orbit; Double star dynamics; Stellar mass and the binary life cycle; The double star population; Detecting double stars; Double star catalogs; Telescope optics; Preparing to observe; Helpful accessories; Viewing challenges; Next steps; Appendices: target list; Useful formulas; Double star orbits; Double star catalogs; The Greek alphabet.

  17. Active Longitudes and Flip-Flops in Binary Stars

    NASA Astrophysics Data System (ADS)

    Korhonen, Heidi; Järvinen, Silva P.

    2007-08-01

    In many active stars the spots concentrate on two permanent active longitudes which are 180 degrees apart. In some of these stars the dominant part of the spot activity changes the longitude every few years. This so-called flip-flop phenomenon was first reported in the early 1990's in the single, late type giant FK Com. Since then flip-flops have been reported also on binary stars, young solar type stars and the Sun itself. Even though this phenomenon has been detected on many different kinds of active stars, still less than ten stars are known to exhibit this effect. Therefore no statistically significant correlation between the stellar parameters and the flip-flop phenomenon can be carried out. Here we present results from investigation where we have studied the long-term photometry of several magnetically active RS CVn binaries to see whether or not they show permanent active longitudes and the flip-flop phenomenon. We find that it is very common for the active regions to occur on permanent active longitudes, and some of these stars also show clear flip-flop phenomenon.

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

    NASA Technical Reports Server (NTRS)

    Ray, R. B.

    1994-01-01

    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

  19. The Impacts of SLC22A1 rs594709 and SLC47A1 rs2289669 Polymorphisms on Metformin Therapeutic Efficacy in Chinese Type 2 Diabetes Patients.

    PubMed

    Xiao, Di; Guo, Yu; Li, Xi; Yin, Ji-Ye; Zheng, Wei; Qiu, Xin-Wen; Xiao, Ling; Liu, Rang-Ru; Wang, Sai-Ying; Gong, Wei-Jing; Zhou, Hong-Hao; Liu, Zhao-Qian

    2016-01-01

    Background. We aimed to investigate the distributive characteristics of SLC22A1 rs594709 and SLC47A1 rs2289669 polymorphisms and their influence on metformin efficacy in Chinese T2DM patients. Methods. The distributions of SLC22A1 rs594709 and SLC47A1 rs2289669 polymorphisms were determined in 267 T2DM patients and 182 healthy subjects. Subsequently, 53 newly diagnosed patients who received metformin monotherapy were recruited to evaluate metformin efficacy. Results. No significant difference was found between T2DM patients and healthy subjects in SLC22A1 rs594709 and SLC47A1 rs2289669 allele frequencies and genotype frequencies. After metformin treatment, SLC22A1 rs594709 GG genotype patients showed a higher increase in FINS (p = 0.015) and decrease in HOMA-IS (p = 0.001) and QUICKI (p = 0.002) than A allele carriers. SLC47A1 rs2289669 GG genotype patients had a higher decrease in TChol (p = 0.030) and LDL-C (p = 0.049) than A allele carriers. Among SLC22A1 rs594709 AA genotype, patients with SLC47A1 rs2289669 AA genotype showed a higher decrease in FBG (p = 0.015), PINS (p = 0.041), and HOMA-IR (p = 0.014) than G allele carriers. However, among SLC22A1 rs594709 G allele carriers, SLC47A1 rs2289669 AA genotype patients showed a higher decrease in TChol (p = 0.013) than G allele carriers. Conclusion. Our data suggest that SLC22A1 rs594709 and SLC47A1 rs2289669 polymorphisms may influence metformin efficacy together in Chinese T2DM patients. PMID:26977146

  20. Association Analysis of NALCN Polymorphisms rs1338041 and rs61973742 in a Chinese Population with Isolated Cervical Dystonia

    PubMed Central

    Zhou, Qingqing; Yang, Jing; Cao, Bei; Chen, Yongping; Wei, Qianqian; Ou, Ruwei; Song, Wei; Zhao, Bi; Wu, Ying; Shang, Huifang

    2016-01-01

    Background. A genome-wide association study (GWAS) demonstrated a possible association between cervical dystonia (CD) and a sodium leak channel, nonselective (NALCN) gene. However, the association between NALCN and CD was largely unknown in Asian population. The present study was carried out to examine the associations between the two single nucleotide polymorphisms (SNPs) rs1338041 and rs61973742 in the NALCN gene and CD in a Chinese population. Methods. In a cohort of 201 patients with isolated CD, we genotyped the two SNPs rs1338041 and rs61973742 using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). We also included 289 unrelated, age- and sex-matched healthy controls (HCs) from the same region. Result. No significant differences were observed in either the genotype distributions or the minor allele frequencies (MAFs) of the two SNPs between the CD patients and the HCs. There were no significant differences between early-onset and late-onset CD patients, between patients with and without a positive family history of dystonia, or between patients with and without tremor or sensory tricks. Conclusion. Lack of association between the SNPs of NALCN and CD suggests that the SNPs of NALCN do not play a role in CD in a Chinese population. PMID:27239368

  1. Association of rs10757274 and rs2383206 Polymorphisms on 9p21 locus with Coronary Artery Disease in Turkish Population

    PubMed Central

    Okyay, Kaan; Yılmaz, Akın; Şahinarslan, Asife; Yar Sağlam, Atiye Seda; Eyiol, Azmi; Bolayır, Hasan Ata; Sezenöz, Burak; Menevşe, Sevda; Çengel, Atiye

    2016-01-01

    Background and Objectives Genetic predisposition is an important risk factor for coronary artery disease (CAD). In this study, we aimed to evaluate the impact of rs10757274 and rs2383206 polymorphisms in chromosome 9p21 on presence and severity of CAD in a Turkish population. Subjects and Methods A total of 646 patients who underwent coronary angiography were included in this study. Coronary vessel score and Gensini score were calculated to assess the angiographic severity of CAD. Alleles of AA, AG, and GG were determined for rs10757274 (polymorphism-1) and rs2383206 (polymorphism-2) polymorphisms located in chromosome 9p21 from the blood samples. Results There was a significant difference between the alleles in polymorphism-1 in the presence of coronary artery disease (38.9% in AA, 48.0% in GG and 56.4% in AG, p=0.017). However, there was no difference between the alleles in polymorphism-2. According to vessel scores, there was a significant difference between the alleles in polymorphism-1 (AA 0.71±1.04, GG 0.88±1.07, AG 1.06±1.12, p=0.018). In polymorphism-2, vessel scores did not show a difference between the alleles. In polymorphism-1, there was a significant difference in Gensini score (p=0.041). Gensini scores did not differ between the alleles in polymorphism-2 (p>0.05 for all). In multivariate analyses, none of the alleles was an independent factor for presence of CAD. Conclusion The presence of rs10757274 polymorphism including AG allele in chromosome 9p21 was related to CAD. However, this relationship was not independent of other cardiovascular risk factors. PMID:27721851

  2. Synthetic direct impact light curves of the ultracompact AM CVn binary systems V407 Vul and HM Cnc

    NASA Astrophysics Data System (ADS)

    Wood, M. A.

    2009-05-01

    The interacting binary white dwarf (AM CVn) systems HM Cnc and V407 have orbital periods of 5.4 and 9.5 min, respectively. The two systems are characterized by an `on/off' behaviour in the X-ray light curve, and optical light curves that are nearly sinusoidal and which lead the X-ray light curves in phase by about 0.2 in both systems. Of the models that have been proposed to explain the observations, the one that seems to require the least fine-tuning is the direct impact model of Marsh & Steeghs. In this model, the white dwarf primary is large enough relative to the semimajor axis that the accretion stream impacts the surface of the primary white dwarf directly without forming an accretion disc. Marsh & Steeghs proposed that in this situation there could be a flow setup around the equator with a decreasing surface temperature, the further one measured from the impact point. In this study, we estimate the light curves that might result from such a temperature distribution, and find them to be reasonable approximations to the observations. One unexpected result is that two distinct X-ray spots must exist to match the shape of the X-ray light curves.

  3. Flank wears Simulation by using back propagation neural network when cutting hardened H-13 steel in CNC End Milling

    NASA Astrophysics Data System (ADS)

    Hazza, Muataz Hazza F. Al; Adesta, Erry Y. T.; Riza, Muhammad

    2013-12-01

    High speed milling has many advantages such as higher removal rate and high productivity. However, higher cutting speed increase the flank wear rate and thus reducing the cutting tool life. Therefore estimating and predicting the flank wear length in early stages reduces the risk of unaccepted tooling cost. This research presents a neural network model for predicting and simulating the flank wear in the CNC end milling process. A set of sparse experimental data for finish end milling on AISI H13 at hardness of 48 HRC have been conducted to measure the flank wear length. Then the measured data have been used to train the developed neural network model. Artificial neural network (ANN) was applied to predict the flank wear length. The neural network contains twenty hidden layer with feed forward back propagation hierarchical. The neural network has been designed with MATLAB Neural Network Toolbox. The results show a high correlation between the predicted and the observed flank wear which indicates the validity of the models.

  4. The Millennium Star Atlas

    NASA Astrophysics Data System (ADS)

    Sinnott, R. W.

    1997-08-01

    Derived from Hipparcos and Tycho observations, the Millennium Star Atlas is a set of 1548 charts covering the entire sky to about magnitude 11. It stands apart from all previous printed atlases in completeness to magnitude 10 and in uniformity around the sky. The generous chart scale has made possible a number of innovations never before seen in a star atlas: arrows on high-proper-motion stars, double-star ticks conveying separation and position angle for a specific modern epoch, distance labels for nearby stars, and variable stars coded by amplitude, period, and type. Among the nonstellar objects plotted, more than 8000 galaxies are shown with aspect ratio and orientation.

  5. The Pistol Star

    NASA Astrophysics Data System (ADS)

    Najarro, F.; Figer, D. F.

    1998-06-01

    Results of an spectroscopic investigation of the Pistol star are presented. The near-infrared spectra and photometry data are fit with stellar wind models to find that the star is extraordinarily luminous, L = 106.7±0.5 L⊙, making it one of the most luminous stars known. Coupled with the relatively cool temperature, Teff = 10^{4.17_{ - 0.06}^{ + 0.19} } K, the star is clearly in violation of the Humphreys-Davidson limit. The derived line of sight velocity of the star assures its membership in the Quintuplet cluster. This, along with the inferred extinction, places the star at the Galactic Center.

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

    NASA Technical Reports Server (NTRS)

    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

    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

  7. Combined effects of FTO rs9939609 and MC4R rs17782313 on elevated nocturnal blood pressure in the Chinese Han population

    PubMed Central

    Sun, Yanlei; Jun, Wu; Sun, Jiazhong; Yang, Mei

    2016-01-01

    Summary Aim In this study we investigated the association of FTO rs9939609 and MC4R. rs17782313 with elevated blood pressure in the Chinese Han population, and analysed the relationship between the rs9939609 and rs17782313 variants. Methods We tested the rs9939609 and rs17782313 variants with the sequence-retrieval method. Results The increase in odds ratios of the A allele of rs9939609 and the C allele of rs17782313 for nocturnal blood pressure were 1.37 and 1.69. The nocturnal blood pressure of participants simultaneously carrying the A and C alleles was significantly higher than the blood pressure of those carrying neither FTO nor MC4R risk alleles (p < 0.05), and that of the controls carrying only the A or C alleles (p < 0.05). No association between the FTO or MC4R genes with daytime hypertension was found in this Chinese population (p > 0.05). Conclusion Our data suggest that the rs9939609 and rs17782313 variants may be significantly associated with nocturnal but not daytime blood pressure levels and their combined effects were significant in this Chinese Han population. PMID:26324055

  8. Association between CYP17A1 rs3824755 and rs743572 gene polymorphisms and Alzheimer's disease in the Chinese Han population.

    PubMed

    Xie, Li; Yan, Huacheng; Shi, Lei; Kong, Yanying; Huang, Mukun; Li, Jian; Li, Jin; Zheng, Jiaqiang; Zhao, Yongpan; Zhao, Shujin

    2016-04-01

    The CYP17A1 gene encodes cytochrome P450c17α, an enzyme that catalyzes the formation of sex hormones, which have been linked to the pathogenesis of Alzheimer's disease (AD). An association between the CYP17A1 rs743572 single nucleotide polymorphism (SNP) and AD has been reported; however, the findings are controversial. In the present study, we investigated the association between rs743572 and another SNP, rs3824755, and AD risk in a Chinese Han population (n=207 patients and 239 controls), and their interaction with the apolipoprotein E (APOE) e4 allele. We found that the C allele and GC+CC genotypes of rs3824755 conferred protection against AD only in APOE e4 carriers. Both rs3824755 and rs743572 polymorphisms showed interactions with APOE e4. The C allele and GC+CC genotypes of rs3824755 acted as protective factors that decreased the risk of APOE e4 in AD. The CYP17A1 rs743572G allele and AG+GG genotypes were found to be potential risk factors that act synergetically with APOE e4. Moreover, the CA and GG haplotypes were protective and conferred a slight risk, respectively, in APOE e4 carriers. These results indicate that CYP17A1 rs3824755 and rs743572 are associated with AD in the Chinese Han population and act in combination with APOE e4.

  9. Dwarf nova-type cataclysmic variable stars are significant radio emitters

    NASA Astrophysics Data System (ADS)

    Coppejans, Deanne L.; Körding, Elmar. G.; Miller-Jones, James C. A.; Rupen, Michael P.; Sivakoff, Gregory R.; Knigge, Christian; Groot, Paul J.; Woudt, Patrick A.; Waagen, Elizabeth O.; Templeton, Matthew

    2016-08-01

    We present 8-12 GHz radio light curves of five dwarf nova (DN) type Cataclysmic Variable stars (CVs) in outburst (RX And, U Gem and Z Cam), or superoutburst (SU UMa and YZ Cnc), increasing the number of radio-detected DN by a factor of two. The observed radio emission was variable on time-scales of minutes to days, and we argue that it is likely to be synchrotron emission. This sample shows no correlation between the radio luminosity and optical luminosity, orbital period, CV class, or outburst type; however higher-cadence observations are necessary to test this, as the measured luminosity is dependent on the timing of the observations in these variable objects. The observations show that the previously detected radio emission from SS Cyg is not unique in type, luminosity (in the plateau phase of the outburst), or variability time-scales. Our results prove that DN, as a class, are radio emitters in outburst.

  10. A non-LTE spectral analysis of the 3He and 4He isotopes in the HgMn star κ Cancri

    NASA Astrophysics Data System (ADS)

    Maza, Natalia L.; Nieva, María-Fernanda; Przybilla, Norbert

    2014-12-01

    Aims: We present a pilot study on non-local thermodynamic equilibrium (NLTE) line-formation computations for the isotopes 3He and 4He in the mercury-manganese star κ Cancri. The impact of NLTE effects on the determination of isotopic abundances and the vertical stratification of helium in the atmosphere is investigated. Methods: Modern NLTE line-formation computations were employed to analyse a high-resolution and high signal-to-noise ratio ESO-VLT/UVES spectrum of κ Cnc. The atmospheric parameters were determined from fitting the hydrogen Balmer lines and the spectral energy distribution. Multiple He i lines were investigated, including He i λ4921 Å and λ6678 Å, which show the widest isotopic splits. Results: Half of the observed He i lines in the spectrum of κ Cnc show significant NLTE strengthening, the effects are strongest in the red lines He iλ5875 Å and He iλ6678 Å. NLTE abundances from individual He i lines are up to a factor of ~3 lower than LTE values. Helium is found to be stratified in the atmosphere of κ Cnc. While the LTE analysis indicates a step-like profile of the helium abundance, a gradual decrease with height is indicated by the NLTE analysis. A 3He/4He ratio of ~0.25-0.30 is found. With the available data it cannot be decided whether the two isotopes follow the same stratification profile, or not. Conclusions: This work implies that NLTE effects may be ubiquitous in the atmospheres of HgMn stars and may have a significant impact on abundance determinations and the interpretation of the vertical abundance stratification of elements. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 076.B-0055(A).Figures 3 and 4 are available in electronic form at http://www.aanda.org

  11. Radiation Dry Bias of the Vaisala RS92 Humidity Sensor

    NASA Technical Reports Server (NTRS)

    Vomel, H.; Selkirk, H.; Miloshevich, L.; Valverde-Canossa, J.; Valdes, J.; Kyro, E.; Kivi, R.; Stolz, W.; Peng, G.; Diaz, J. A.

    2007-01-01

    The comparison of simultaneous humidity measurements by the Vaisala RS92 radiosonde and by the Cryogenic Frostpoint Hygrometer (CFH) launched at Alajuela, Cosla Rica, during July 2005 reveals a large solar radiation dry bias of the Vaisala RS92 humidity sensor and a minor temperature-dependent calibration error. For soundings launched at solar zenith angles between 10" and 30 , the average dry bias is on the order of 9% at the surface and increases to 50% at 15 km. A simple pressure- and temperature-dependent correction based on the comparison with the CFH can reduce this error to less than 7% at all altitudes up to 15.2 km, which is 700 m below the tropical tropopause. The correction does not depend on relative humidity, but is able to reproduce the relative humidity distribution observed by the CFH.

  12. RS Ophiuchi: The Gift that Keeps on Giving

    NASA Astrophysics Data System (ADS)

    Starrfield, S.

    2008-12-01

    RS Oph experienced its sixth recorded outburst in 2006 and was observed in virtually every wavelength region from hard X-rays to the radio. Each observation, especially those with instruments that have come online since its last outburst in 1985, provided new and exciting information about the explosion. As a result, some of us organized a second workshop on the RS Oph outburst and it was held in June 2007 at Keele University. I gave the lead off talk in which I presented a number of questions to be discussed during the workshop, a brief summary of what had been discovered in previous outbursts concentrating on the ultraviolet studies with IUE, and a few observations of the 2006 outburst concentrating on the results from Swift and HST.

  13. Intrinsically variable stars

    NASA Technical Reports Server (NTRS)

    Bohm-Vitense, Erika; Querci, Monique

    1987-01-01

    The characteristics of intrinsically variable stars are examined, reviewing the results of observations obtained with the IUE satellite since its launch in 1978. Selected data on both medium-spectral-class pulsating stars (Delta Cep stars, W Vir stars, and related groups) and late-type variables (M, S, and C giants and supergiants) are presented in spectra, graphs, and tables and described in detail. Topics addressed include the calibration of the the period-luminosity relation, Cepheid distance determination, checking stellar evolution theory by the giant companions of Cepheids, Cepheid masses, the importance of the hydrogen convection zone in Cepheids, temperature and abundance estimates for Population II pulsating stars, mass loss in Population II Cepheids, SWP and LWP images of cold giants and supergiants, temporal variations in the UV lines of cold stars, C-rich cold stars, and cold stars with highly ionized emission lines.

  14. Star Formation in Galaxies

    NASA Technical Reports Server (NTRS)

    1987-01-01

    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.

  15. Astrophysics: Stars fight back

    NASA Astrophysics Data System (ADS)

    Hopkins, Philip F.

    2014-12-01

    Galaxies contain fewer stars than predicted. The discovery of a massive galactic outflow of molecular gas in a compact galaxy, which forms stars 100 times faster than the Milky Way, may help to explain why. See Letter p.68

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

    ERIC Educational Resources Information Center

    McLure, John W.

    1984-01-01

    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…

  17. Symbiotic stars and other Hα emission-line stars towards the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Miszalski, Brent; Mikołajewska, Joanna; Udalski, Andrzej

    2013-07-01

    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 Hα 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

  18. Chromospheres of Coronal Stars

    NASA Technical Reports Server (NTRS)

    Linsky, Jeffrey L.; Wood, Brian E.

    1996-01-01

    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.

  19. Dibaryons in neutron stars

    NASA Technical Reports Server (NTRS)

    Olinto, Angela V.; Haensel, Pawel; Frieman, Joshua A.

    1991-01-01

    The effects are studied of H-dibaryons on the structure of neutron stars. It was found that H particles could be present in neutron stars for a wide range of dibaryon masses. The appearance of dibaryons softens the equations of state, lowers the maximum neutron star mass, and affects the transport properties of dense matter. The parameter space is constrained for dibaryons by requiring that a 1.44 solar mass neutron star be gravitationally stable.

  20. Alkaline protease from Thermoactinomyces sp. RS1 mitigates industrial pollution.

    PubMed

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

    2014-05-01

    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.

  1. The long-period Galactic Cepheid RS Puppis. III. A geometric distance from HST polarimetric imaging of its light echoes

    NASA Astrophysics Data System (ADS)

    Kervella, P.; Bond, H. E.; Cracraft, M.; Szabados, L.; Breitfelder, J.; Mérand, A.; Sparks, W. B.; Gallenne, A.; Bersier, D.; Fouqué, P.; Anderson, R. I.

    2014-12-01

    As one of the most luminous Cepheids in the Milky Way, the 41.5-day RS Puppis is an analog of the long-period Cepheids used to measure extragalactic distances. An accurate distance to this star would therefore help anchor the zero-point of the bright end of the period-luminosity relation. But, at a distance of about 2 kpc, RS Pup is too far away for measuring a direct trigonometric parallax with a precision of a few percentage points with existing instrumentation. RS Pup is unique by being surrounded by a reflection nebula whose brightness varies as pulses of light from the Cepheid propagate outward. We present new polarimetric imaging of the nebula obtained with HST/ACS. The derived map of the degree of linear polarization pL allows us to reconstruct the three-dimensional structure of the dust distribution. To retrieve the scattering angle from the pL value, we consider two different polarization models, one based on a Milky Way dust mixture and one assuming Rayleigh scattering. Considering the derived dust distribution in the nebula, we adjust a model of the phase lag of the photometric variations over selected nebular features to retrieve the distance of RS Pup. We obtain a distance of 1910 ± 80 pc (4.2%), corresponding to a parallax of π = 0.524 ± 0.022 mas. The agreement between the two polarization models that we considered is good, but the final uncertainty is dominated by systematics in the adopted model parameters. The distance we obtain is consistent with existing measurements from the literature, but light echoes provide a distance estimate that is not subject to the same systematic uncertainties as other estimators (e.g., the Baade-Wesselink technique). RS Pup therefore provides an important fiducial for calibrating the systematic uncertainties of the long-period Cepheid distance scale. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of

  2. America's Star Libraries

    ERIC Educational Resources Information Center

    Lyons, Ray; Lance, Keith Curry

    2009-01-01

    "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…

  3. Managing the star performer.

    PubMed

    Hills, Laura

    2013-01-01

    Our culture seems to be endlessly fascinated with its stars in entertainment, athletics, politics, and business, and holds fast to the idea that extraordinary talent accounts for an individual's extraordinary performance. At first glance, managing a star performer in your medical practice may seem like it would be an easy task. However, there's much more to managing a star performer than many practice managers realize. The concern is how to keep the star performer happy and functioning at a high level without detriment to the rest of the medical practice team. This article offers tips for practice managers who manage star performers. It explores ways to keep the star performer motivated, while at the same time helping the star performer to meld into the existing medical practice team. This article suggests strategies for redefining the star performer's role, for holding the star performer accountable for his or her behavior, and for coaching the star performer. Finally, this article offers practical tips for keeping the star performer during trying times, for identifying and cultivating new star performers, and for managing medical practice prima donnas. PMID:23767124

  4. Saturn's nonaxisymmetric ring edges at 1.95 R(s) and 2.27 R(s)

    NASA Astrophysics Data System (ADS)

    Porco, C.; Danielson, G. E.; Goldreich, P.; Holberg, J. B.; Lane, A. L.

    1984-10-01

    The outer edges of Saturn's A and B rings, at 2.27 Rs and 1.95 Rs, have been examined using data acquired by four Voyager experiments. The shapes and kinematics of these features are influenced by their proximity to strong low-order Lindblad resonances. The data for the A-ring edge are consistent with a seven-lobed radial distortion of amplitude 6.7±1.5 km which rotates with the mass-weighted mean angular velocity of the coorbital satellite system. The B-ring edge has essentially, a double-lobed figure of radial amplitude 74±9 km which rotates with the mean motion of Mimas, though there is an indication that it is not completely described with a simple Saturn-centered ellipse. An upper limit of 10 m has been placed on the vertical thickness in the unperturbed region of the B ring.

  5. Genetic Association for P2X7R rs3751142 and CARD8 rs2043211 Polymorphisms for Susceptibility of Gout in Korean Men: Multi-Center Study

    PubMed Central

    2016-01-01

    The aim of this study was to determine the association between P2X7R rs3751142 and CARD8 rs2043211 polymorphisms and gout susceptibility in male Korean subjects. This study enrolled a total of 242 male patients with gout and 280 healthy controls. The polymorphisms of two individual genes including rs3751142(C>A) in the P2X7R gene and rs2043211(A>T) in the CARD8 gene were assessed using Taq-Man analysis. Statistical analyses were performed using the Chi-square test, Kruskal-Wallis test, and logistic regression analyses. A difference in genotypic frequency of the P2X7R rs3751142 and CARD8 rs2043211 genes was not detected between gout and control patients. Clinical parameters including age, onset age, disease duration, body mass index, and serum uric acid levels were not different among the three genotypes for either P2X7R or CARD8 (P > 0.05 for all). A pair-wise comparison of P2X7R rs3751142 and CARD8 rs2043211 genotype combinations revealed that subjects with the CA P2X7R rs3751142 genotype and the TT CARD8 rs2043211 genotype had a trend toward a higher risk of gout compared to the CC/AA combination (P = 0.056, OR = 2.618, 95% CI 0.975 - 7.031). In conclusion, this study revealed that genetic variability of the P2X7R rs3751142 and CARD8 rs2043211 genes might, in part, be associated with susceptibility for gout. PMID:27550484

  6. Genetic Association for P2X7R rs3751142 and CARD8 rs2043211 Polymorphisms for Susceptibility of Gout in Korean Men: Multi-Center Study.

    PubMed

    Lee, Sung Won; Lee, Shin Seok; Oh, Dong Ho; Park, Dong Jin; Kim, Hyun Sook; Choi, Jung Ran; Chae, Soo Cheon; Yun, Ki Jung; Chung, Won Tae; Choe, Jung Yoon; Kim, Seong Kyu

    2016-10-01

    The aim of this study was to determine the association between P2X7R rs3751142 and CARD8 rs2043211 polymorphisms and gout susceptibility in male Korean subjects. This study enrolled a total of 242 male patients with gout and 280 healthy controls. The polymorphisms of two individual genes including rs3751142(C>A) in the P2X7R gene and rs2043211(A>T) in the CARD8 gene were assessed using Taq-Man analysis. Statistical analyses were performed using the Chi-square test, Kruskal-Wallis test, and logistic regression analyses. A difference in genotypic frequency of the P2X7R rs3751142 and CARD8 rs2043211 genes was not detected between gout and control patients. Clinical parameters including age, onset age, disease duration, body mass index, and serum uric acid levels were not different among the three genotypes for either P2X7R or CARD8 (P > 0.05 for all). A pair-wise comparison of P2X7R rs3751142 and CARD8 rs2043211 genotype combinations revealed that subjects with the CA P2X7R rs3751142 genotype and the TT CARD8 rs2043211 genotype had a trend toward a higher risk of gout compared to the CC/AA combination (P = 0.056, OR = 2.618, 95% CI 0.975 - 7.031). In conclusion, this study revealed that genetic variability of the P2X7R rs3751142 and CARD8 rs2043211 genes might, in part, be associated with susceptibility for gout. PMID:27550484

  7. Another functional frame-shift polymorphism of DEFB126 (rs11467497) associated with male infertility.

    PubMed

    Duan, Shiwei; Shi, Changgeng; Chen, Guowu; Zheng, Ju-fen; Wu, Bin; Diao, Hua; Ji, Lindan; Gu, Yihua; Xin, Aijie; Wu, Yancheng; Zhou, Weijin; Miao, Maohua; Xu, Limin; Li, Zheng; Yuan, Yao; Wang, Peng; Shi, Huijuan

    2015-05-01

    DEFB126 rs140685149 mutation was shown to cause sperm dysfunction and subfertility. Indel rs11467497 is another 4-nucleotide frame-shift mutation (151bp upstream of rs140685149) that leads to the premature termination of translation and the expression of peptide truncated at the carboxyl terminus. In the present study, we performed a comprehensive association study to check the contribution of rs140685149 and rs11467497 to male infertility. Our results confirmed the previous findings that there was no association between rs140685149 and sperm motility. In contrast, we found a significant association of another indel rs11467497 with male infertility. Moreover, rs11467497 was shown to be associated with higher number of round cells in the infertile males with low sperm motility. Surprisingly, the two mutations commonly existed in the sperm donors (n = 672), suggesting a potential application of the two indels in the screening for eligible sperm donors. Western blotting assays showed the sperms with rs140685149 2-nt deletion tended to have unstable DEFB126 protein in contrast of no DEFB126 protein expressed in the sperms with rs11467497 4-nt deletion, suggesting a more severe consequence caused by rs11467497 mutation. In conclusion, our study presented a significant contribution of another functional frame-shift polymorphism of DEFB126 (rs11467497) to male infertility.

  8. Another functional frame-shift polymorphism of DEFB126 (rs11467497) associated with male infertility.

    PubMed

    Duan, Shiwei; Shi, Changgeng; Chen, Guowu; Zheng, Ju-fen; Wu, Bin; Diao, Hua; Ji, Lindan; Gu, Yihua; Xin, Aijie; Wu, Yancheng; Zhou, Weijin; Miao, Maohua; Xu, Limin; Li, Zheng; Yuan, Yao; Wang, Peng; Shi, Huijuan

    2015-05-01

    DEFB126 rs140685149 mutation was shown to cause sperm dysfunction and subfertility. Indel rs11467497 is another 4-nucleotide frame-shift mutation (151bp upstream of rs140685149) that leads to the premature termination of translation and the expression of peptide truncated at the carboxyl terminus. In the present study, we performed a comprehensive association study to check the contribution of rs140685149 and rs11467497 to male infertility. Our results confirmed the previous findings that there was no association between rs140685149 and sperm motility. In contrast, we found a significant association of another indel rs11467497 with male infertility. Moreover, rs11467497 was shown to be associated with higher number of round cells in the infertile males with low sperm motility. Surprisingly, the two mutations commonly existed in the sperm donors (n = 672), suggesting a potential application of the two indels in the screening for eligible sperm donors. Western blotting assays showed the sperms with rs140685149 2-nt deletion tended to have unstable DEFB126 protein in contrast of no DEFB126 protein expressed in the sperms with rs11467497 4-nt deletion, suggesting a more severe consequence caused by rs11467497 mutation. In conclusion, our study presented a significant contribution of another functional frame-shift polymorphism of DEFB126 (rs11467497) to male infertility. PMID:25721098

  9. [Anorexia nervosa with refeeding syndrome: prevention and treatment of RS].

    PubMed

    Kasai, Makiko; Okajima, Yoshirou; Takano, Eisuke; Kato, Satoshi

    2009-01-01

    Refeeding syndrome (RS), seen in the early stages of anorexia nervosa (AN) treatment, has not been paid sufficient attention regarding its strong association with poor outcomes. This report describes a case of AN restriction type (AN-R) with sequent RS appearance despite the introduction of progressive and careful low-calorie nutrition, and discusses RS treatment. The patient was a 16-year-old female. She was first diagnosed with AN at the age of 14 when she went on a diet, admitted into pediatrics, and recovered: however, AN recurred after she started high school, and her weight decreased to 31.8 kg. She was admitted to pediatrics again, refused to receive treatment, discharged from the hospital, and introduced to our department. Soon after she came to us, her weight went down to 29.6 kg, and continued to decrease to 26.8 kg. She was recommended to receive inpatient care, but she firmly refused. A few days later, her experience of loss of consciousness made her agree to receive inpatient care. At this time, she was already weakened and had difficulty performing voluntary body movements as well as excretion. She was treated carefully and placed on 125 kcal/day. On the 6th day of treatment, severe liver damage was observed, her serum phosphorus level went down to 2.0 mg/dL, and she was diagnosed with RS. The lowest concentration of serum phosphorus observed was 1.3 mg/dL with blood abnormality and delirium; however, our strict management with intravascular phosphorus administration supported her increased dietary intake, and the patient was able to leave the hospital on the 54th day after admission. Based on this experience, the pathogenesis of RS was overviewed, and RS prevention as well as treatment was discussed. It has been reported that low phosphorus levels are observed in approximately one quarter of AN patients, and, thus, immediate action and treatment of hypophosphatemia are necessary when considering RS occurrence. In this study, the observed serum

  10. ChemLabBox for SnifferStars

    2002-01-24

    The software entitled "ChemLabBox for SnifferStars" is used to collect, display, and save data from the Sandia National Laboratories chemical analysis system dubbed SnifferStar. Sensor data is streamed from a SnifferStar unit into a computer thru RS-232 in a manner that is not amendable to plotting. Also, there is no direct way to start and stop the unit as is. This software rearranges the data into something that can be easily plotted in real-time thenmore » saves the data into a text fild. In addition, this software provides the users a means to start and stop the hardware. This software was written specifically for SnifferStar. SnifferStar data is delivered at a very fast rate but for a short period of time. This software is written around that premise. It is written for Pentium or higher machines running Windows 95/98/ME/NT/2000/XP. Lockheed Martin is interested in using it for testing SnifferStar units before deployment. To date they have not indicated their intent to deliver the code either in part or whole as part of their product.« less

  11. IL-4 receptor alpha single-nucleotide polymorphisms rs1805010 and rs1801275 are associated with increased risk of asthma in a Saudi Arabian population

    PubMed Central

    Al-Muhsen, Saleh; Vazquez-Tello, Alejandro; Alzaabi, Ashraf; Al-Hajjaj, Mohamed S.; Al-Jahdali, Hamdan H.; Halwani, Rabih

    2014-01-01

    BACKGROUND: The IL-4 receptor alpha subunit (IL-4Rα), when associated with the common gamma chain receptor, or the IL-13Rα1 subunit, transduces signals to STAT6 in response to IL-4 and IL-13 stimulations. This results in a number of cell-specific responses including Th2 differentiation, lymphocyte proliferation and IgE production. Given the prominent role of IL-4Rα in allergic disorders, several single-nucleotide polymorphisms (SNPs) have been found associated with asthma and other atopic disorders, including rs1805010 (I75V) and rs1801275 (Q576R) SNPs; however, lack of significant association have also been reported for some ethnic groups. The objective of this study was to determine whether IL-4Rα rs1805010 and rs1801275 polymorphisms are associated with asthma in patients from Saudi Arabia. MATERIALS AND METHODS: One hundred and ninety severe asthmatic patients (11-70 years old) and 194 healthy subjects of equivalent age range were recruited for blood donation. DNA was purified and genotyping for rs1801275 and rs1805010 polymorphisms in the IL-4Rα gene was performed by PCR amplification, followed by cycle sequencing of the purified PCR fragments using BigDye chain terminator and capillary electrophoresis. RESULTS: Pearson's Chi-square tests showed that the minor alleles, G, for both rs1805010 and rs1801275 SNPs, were significantly more frequent in asthmatics than in the healthy group (Yates’ P < 0.05); conversely, the major alleles, A, were significantly more frequent in healthy than in asthmatics (P < 0.05). Concerning association analysis, odds for A/G-G/G genotypes were significantly higher to be associated with asthma predisposition (rs1801275: OR = 2.12; 95% CI = 1.39-3.22; P < 0.001*; rs1805010: OR = 1.6; 95% CI = 1.01-2.53; P < 0.05*; dominant model). Analysis of gender-genotype interactions, with genders nested within A/G-G/G, indicated higher odds for females than males of significant association with asthma (rs1801275: OR = 5.19, 95% CI = 2

  12. Role of IL-17A rs2275913 and IL-17F rs763780 polymorphisms in risk of cancer development: an updated meta-analysis

    PubMed Central

    Dai, Zhi-Ming; Zhang, Tian-Song; Lin, Shuai; Zhang, Wang-Gang; Liu, Jie; Cao, Xing-Mei; Li, Hong-Bao; Wang, Meng; Liu, Xing-Han; Liu, Kang; Li, Shan-Li; Dai, Zhi-Jun

    2016-01-01

    Single nucleotide polymorphisms (SNPs) in the interleukin-17 (IL-17) gene have been shown to be correlated with susceptibility to cancer. However, various studies report different results of this association. The aim of the present work was to clarify the effects of IL-17A G197A (rs2275913) and IL-17F T7488C (rs763780) polymorphisms on cancer risk. We performed systematic searches of the PubMed and CNKI databases to obtain relevant publications. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association of rs2275913 and rs763780 polymorphisms with cancer risk. Data were extracted from the selected studies, and statistical analysis was conducted using the STATA software. Our results indicated that rs2275913 and rs763780 polymorphisms significantly increase cancer risk, especially in gastric cancers. Subgroup analysis suggested the existence of a significant correlation between rs763780 polymorphism and cancer susceptibility in Caucasian populations. This updated meta-analysis confirms that rs2275913 and rs763780 polymorphisms are highly associated with increased risk for multiple forms of cancer. PMID:26843459

  13. Physico-chemical, functional and structural properties of RS3/RS4 from kidney bean (Phaseolus vulgaris) cultivars.

    PubMed

    Gani, Adil; Jan, Amreen; Shah, Asima; Masoodi, F A; Ahmad, Mudasir; Ashwar, Bilal Ahmad; Akhter, Rehana; Wani, Idrees Ahmed

    2016-06-01

    Starch isolated from four kidney bean cultivars (Yellow bean, Red bean, Black bean and White bean) were physically and chemically modified in order to prepare resistant starch (RS3/RS4). Following the Heat-moisture treatment (HMT) and Citric acid modification (CT) of the native starch, the amylose content got decreased whereas bulk and tapped density (g/ml) increased. Both HMT and CT reduced the swelling power and the solubility of native starch. Pasting temperature increased and peak, breakdown, final, and set-back viscosity decreased after both the modifications. Fourier Transform Infrared Spectroscopy (FTIR) analysis displayed peaks at 1020cm(-1) in HMT and 1724cm(-1) in CT starches. Differential Scanning Calorimetry (DSC) analysis revealed that samples were more stable after modification. X-ray diffraction (XRD) analysis revealed reordering of chain segments to more crystalline structure. These results suggested modifications resulted in starch with improved properties and could be a possible method for the RS preparation with better thermal stability. PMID:26976068

  14. Physico-chemical, functional and structural properties of RS3/RS4 from kidney bean (Phaseolus vulgaris) cultivars.

    PubMed

    Gani, Adil; Jan, Amreen; Shah, Asima; Masoodi, F A; Ahmad, Mudasir; Ashwar, Bilal Ahmad; Akhter, Rehana; Wani, Idrees Ahmed

    2016-06-01

    Starch isolated from four kidney bean cultivars (Yellow bean, Red bean, Black bean and White bean) were physically and chemically modified in order to prepare resistant starch (RS3/RS4). Following the Heat-moisture treatment (HMT) and Citric acid modification (CT) of the native starch, the amylose content got decreased whereas bulk and tapped density (g/ml) increased. Both HMT and CT reduced the swelling power and the solubility of native starch. Pasting temperature increased and peak, breakdown, final, and set-back viscosity decreased after both the modifications. Fourier Transform Infrared Spectroscopy (FTIR) analysis displayed peaks at 1020cm(-1) in HMT and 1724cm(-1) in CT starches. Differential Scanning Calorimetry (DSC) analysis revealed that samples were more stable after modification. X-ray diffraction (XRD) analysis revealed reordering of chain segments to more crystalline structure. These results suggested modifications resulted in starch with improved properties and could be a possible method for the RS preparation with better thermal stability.

  15. Debunking the Myth of Two-Temperature Coronae for RS CVn Systems Using Contemporaneous

    NASA Astrophysics Data System (ADS)

    Linsky, Jeffrey L.

    For many years the standard analysis of low energy resolution x-ray observations of active late-type stars with the IPC, PSPC, TGS, and SSS has been to assume that the stellar coronae have plasma at only two temperatures. This type of analysis is constrained by the small information content and limited bandpass of the data but has NO PHYSICAL BASIS WHATSOEVER. We propose to test this hypothesis and to go beyond it to derive continuous emission measure distributions for the coronae of three very bright RS CVn systems (sigma-2 Cor Bor, UX Ari and VY Ari) using CONTEMPORANEOUS high resolution EUVE spectra and the improved x-ray energy resolution of ASCA. EUVE provides Fe lines with a broad range of ionization to derive the emission measure EM(T) independent of any uncertainties in the coronal abundances, while ASCA provides information on the hot plasma as seen in blended features of Mg, Si, S, and Fe and can test for coronal abundances different from the photosphere. We will model the quiescent and flare emission with magnetic loops.

  16. Ponderable soliton stars

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1990-01-01

    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.

  17. Star field simulator

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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. Preflight tests and simulations using various levels of guide stars are performed in the test facility to establish performance of the motion compensation system before being used in a flight environment. The ASTRO Star Tracker operates over a wide dynamic range of irradiance corresponding to visual stellar magnitudes of -0.8 to 8. A minimum of three simulated guide stars with variable magnitudes are needed to fully test the Star Tracker performance under simulated mission conditions.

  18. Exceptional longevity and muscle and fitness related genotypes: a functional in vitro analysis and case-control association replication study with SNPs THRH rs7832552, IL6 rs1800795, and ACSL1 rs6552828

    PubMed Central

    Fuku, Noriyuki; He, Zi-hong; Sanchis-Gomar, Fabian; Pareja-Galeano, Helios; Tian, Ye; Arai, Yasumichi; Abe, Yukiko; Murakami, Haruka; Miyachi, Motohiko; Zempo, Hirofumi; Naito, Hisashi; Yvert, Thomas; Verde, Zoraida; Venturini, Letizia; Fiuza-Luces, Carmen; Santos-Lozano, Alejandro; Rodriguez-Romo, Gabriel; Ricevuti, Giovanni; Hirose, Nobuyoshi; Emanuele, Enzo; Garatachea, Nuria; Lucia, Alejandro

    2015-01-01

    There are several gene variants that are candidates to influence functional capacity in long-lived individuals. As such, their potential association with exceptional longevity (EL, i.e., reaching 100+ years) deserves analysis. Among them are rs7832552 in the thyrotropin-releasing hormone receptor (TRHR) gene, rs1800795 in the interleukin-6 (IL6) gene and rs6552828 in the coenzyme A synthetase long-chain 1 (ACSL1) gene. To gain insight into their functionality (which is yet unknown), here we determined for the first time luciferase gene reporter activity at the muscle tissue level in rs7832552 and rs6552828. We then compared allele/genotype frequencies of the 3 abovementioned variants among centenarians [n = 138, age range 100–111 years (114 women)] and healthy controls [n = 334, 20–50 years (141 women)] of the same ethnic and geographic origin (Spain). We also studied healthy centenarians [n = 79, 100–104 years (40 women)] and controls [n = 316, 27–81 years (156 women)] from Italy, and centenarians [n = 742, 100–116 years (623 women)] and healthy controls [n = 499, 23–59 years (356 women)] from Japan. The THRH rs7832552 T-allele and ACSL1 rs6552828 A-allele up-regulated luciferase activity compared to the C and G-allele, respectively (P = 0.001). Yet we found no significant association of EL with rs7832552, rs1800795 or rs6552828 in any of the 3 cohorts. Further research is needed with larger cohorts of centenarians of different origin as well as with younger old people. PMID:25999849

  19. High-Resolution N-Band Observations of the Nova Rs Ophiuchi: First Science with the Keck Interferometer Nuller

    NASA Technical Reports Server (NTRS)

    Danchi, William

    2008-01-01

    We report new observations of the nova RS Ophiuchi using the Keck Interferometer Nulling Instrument (KIN), approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. These observations represent the first scientific results from the KIN, which operates in N-band from 8 to 12.5 microns. The nulling technique is the sparse aperture equivalent of the conventional coronagraphic technique used in filled aperture telescopes. By fitting the unique KIN 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, and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission and atomic metals including silicon located in the inner spatial regime near the white dwarf 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 2.5E14 cm from the WD, that are not found in the inner regime. The nova flash in the outer spatial regime evidently excited these features before the blast wave reached these regions. These identifications support the following interpretation. The dust appears to be present between outbursts and was not created during the outburst event. We further 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 Earthlike planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.

  20. Polymorphism of rs7688672 and rs10033237 in cGKII/PRKG2 and gout susceptibility of Han population in northern China.

    PubMed

    Guo, Min; Cheng, Zhifeng; Li, Changgui; Li, Shanshan; Li, Ming; Wang, Mingli; Xu, Jinmei; Tang, Yingying; Wang, Yujing; Qiu, Wenli; Liu, Xiaomin

    2015-05-10

    Gout is a genetic or acquired metabolic disease caused by increase of uric acid synthesis resulted from purine metabolic abnormalities. Whether cGMP-dependent protein kinase 2 (cGKII/PRKG2) is correlated with gout remains controversial. The objective of the present study was to investigate whether there is a correlation between polymorphism of cGKII/PRKG2 and gout susceptibility of Han population in northern China. Four hundred and five male patients with gout in the case group and 429 controls in the control group were collected from the Department of Endocrinology and Metabolic Disease, the Fourth Affiliated Hospital of Harbin Medical University. A case-control study method was used to study the correlation between cGKII/PRKG2 polymorphism rs7688672 and rs10033237 and gout susceptibility. The genotype frequencies of rs7688672 and rs10033237 polymorphisms of cGKII/PRKG2 in the case group and the control group both were in accordance with Hardy-Weinberg equilibrium. There were significant differences of rs10033237 in the allele frequencies and genotype distributions (P<0.05) between the two groups, while no association was found between rs7688672 and gout. Combined mutation sites AA(*) from rs7688672 and rs10033237 were negatively correlated with gout susceptibility, whereas haplotype GG(*) was positively correlated with gout susceptibility. In conclusion, patients with rs10033237 polymorphism of cGKII/PRKG2 gene are more likely to suffer from gout. With regard to haplotypes of rs10033237 and rs7688672, both AA(*) and GG(*) are related to gout. AA(*) is a gout susceptible gene, whereas GG(*) is a protective gene.

  1. Starspot Model of RS CVn Type Binary SZ PSC

    NASA Astrophysics Data System (ADS)

    Kang, Young-Woon

    2000-12-01

    The emission lines of the ultraviolet region and the light curves of the optical region have been analyzed to investigate the distorted light curves of SZ Psc. The Mg II emission lines of the IUE spectra confirmed that the chromospheric activity of SZ Psc occurs on the K1 IV star. The distorted light curves in the optical region have been analyzed by the spot model where the spots are on the K1 IV star as the result of the chromospheric activity. The complete photometric solution could be deduced for SZ Psc by the good fitness with the spot model.

  2. RS CVn binaries: Testing the solar-stellar dynamo connection

    NASA Technical Reports Server (NTRS)

    Dempsey, R.

    1995-01-01

    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.

  3. Transcription factor 4 gene rs9960767 polymorphism in bipolar disorder

    PubMed Central

    Ozel, Mavi Deniz; Onder, Mehmet Emin; Sazci, Ali

    2016-01-01

    The transcription factor 4 (TCF4) gene encodes a helix-loop-helix transcription factor protein, which initiates neuronal differentiation and is primarily expressed during nervous system development. The aim of the present study is to investigate the association of the TCF4 rs9960767 polymorphism and bipolar disorder, which is highly heritable. DNA isolation was performed on 95 patients with bipolar disorder and 108 healthy control subjects to examine the TCF4 rs9960767 polymorphism. Genotypic and allelic frequencies were determined using the polymerase chain reaction-restriction fragment length polymorphism method designed in our laboratory. Statistical analysis was performed using χ2 test within the 95% confidence interval. Odds ratios were calculated and Hardy-Weinberg equilibrium (HWE) was verified for all control subjects and patients. The A allele frequency was 95.8% in the patients and 94.4% in the control subjects, and 4.2% in the patients and 5.6% in the control subjects for the C allele. The genotype frequencies of the TCF4 gene rs9960767 variant were as follows: AA, 91.6% and AC, 8.4% in patients with bipolar (CC genotype was not observed in cases); AA, 89.8%; AC, 9.3% and CC, 0.9% in the control subjects. No statistically significant difference was identified between the patients and control subjects (χ2=0.937; P=0.626). In addition, gender specific analysis was performed, although no significant association was found according to the gender distrubition. All patients and control subjects were in HWE (P>0.05). Statistical analysis of the data indicates that the TCF4 gene rs9960767 polymorphism is not an independent risk factor for bipolar disorder in the overall population or in terms of gender; however, an increased population size would improve the statistical power. Furthermore, additional gene variants that are specifically involved in neuronal development may be analyzed for revealing the complex genetic architecture of bipolar disorder. An

  4. Transcription factor 4 gene rs9960767 polymorphism in bipolar disorder

    PubMed Central

    Ozel, Mavi Deniz; Onder, Mehmet Emin; Sazci, Ali

    2016-01-01

    The transcription factor 4 (TCF4) gene encodes a helix-loop-helix transcription factor protein, which initiates neuronal differentiation and is primarily expressed during nervous system development. The aim of the present study is to investigate the association of the TCF4 rs9960767 polymorphism and bipolar disorder, which is highly heritable. DNA isolation was performed on 95 patients with bipolar disorder and 108 healthy control subjects to examine the TCF4 rs9960767 polymorphism. Genotypic and allelic frequencies were determined using the polymerase chain reaction-restriction fragment length polymorphism method designed in our laboratory. Statistical analysis was performed using χ2 test within the 95% confidence interval. Odds ratios were calculated and Hardy-Weinberg equilibrium (HWE) was verified for all control subjects and patients. The A allele frequency was 95.8% in the patients and 94.4% in the control subjects, and 4.2% in the patients and 5.6% in the control subjects for the C allele. The genotype frequencies of the TCF4 gene rs9960767 variant were as follows: AA, 91.6% and AC, 8.4% in patients with bipolar (CC genotype was not observed in cases); AA, 89.8%; AC, 9.3% and CC, 0.9% in the control subjects. No statistically significant difference was identified between the patients and control subjects (χ2=0.937; P=0.626). In addition, gender specific analysis was performed, although no significant association was found according to the gender distrubition. All patients and control subjects were in HWE (P>0.05). Statistical analysis of the data indicates that the TCF4 gene rs9960767 polymorphism is not an independent risk factor for bipolar disorder in the overall population or in terms of gender; however, an increased population size would improve the statistical power. Furthermore, additional gene variants that are specifically involved in neuronal development may be analyzed for revealing the complex genetic architecture of bipolar disorder. An

  5. Radio polarization characteristics of two RS CVn binaries

    NASA Technical Reports Server (NTRS)

    Mutel, R. L.; Lestrade, J.-F.; Doiron, D. J.

    1985-01-01

    The results of multifrequency epoch VLA observations of polarized radio emission from the nearby active RS CVn binaries UX Arietis and HR 1099 are reported. For both systems, there is an excellent correlation between handedness of circular polarization and frequency. Helicity reversal is almost always seen between 1.4 and 5.0 GHz, possibly due to optical depth effects. There may also be an anticorrelation between total intensity and fractional circular polarization, especially at 5 GHz. This is consistent with models in which intense flares are associated with compact selfabsorbed synchrotron sources, while the quiescent emission arises from larger gyrosynchrotron-emitting plasma.

  6. Dark stars: a review.

    PubMed

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only [Formula: see text]0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (∼10 AU) and cool (surface temperatures  ∼10 000 K) objects. We follow the evolution of dark stars from their inception at  ∼[Formula: see text] as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >[Formula: see text] and luminosities  >[Formula: see text], making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars. PMID:27214049

  7. Dark stars: a review

    NASA Astrophysics Data System (ADS)

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only ≲ 0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (˜10 AU) and cool (surface temperatures  ˜10 000 K) objects. We follow the evolution of dark stars from their inception at  ˜1{{M}⊙} as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >{{10}6}{{M}⊙} and luminosities  >{{10}10}{{L}⊙} , making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  8. Dark stars: a review

    NASA Astrophysics Data System (ADS)

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only ≲ 0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (∼10 AU) and cool (surface temperatures  ∼10 000 K) objects. We follow the evolution of dark stars from their inception at  ∼1{{M}ȯ} as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >{{10}6}{{M}ȯ} and luminosities  >{{10}10}{{L}ȯ} , making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  9. Intergalactic Star Formation

    NASA Astrophysics Data System (ADS)

    Boquien, Médéric

    2007-11-01

    The work presented here is about star formation in the unusual environment of collisional debris studied for the first time as such. These peculiar regions have an interstellar medium, and in particular a metallicity, similar to that of star forming regions in galactic discs while not undergoing similar environment effects such as density waves in the spiral arms for instance. This study has been conducted with a selection of exceptional systems that have ejected large quantities of gas into the intergalactic medium while also showing some intergalactic star forming regions. Principal Investigator as well as archive spectroscopy and imaging from multi-wavelength observations ranging from far ultraviolet to mid-infrared have been used. Withal a model has been built in order to reproduce the spectral energy distributions of intergalactic star forming regions and constrain the star formation histories, their extinctions and their fraction of stars coming from the parent galaxies' discs. Comparisons have been performed on the estimation of star formation rates between infrared, Halpha and ultraviolet wavelengths. This thesis has brought the following main new results: * some regions seem to be deprived of any old stellar population, and these are ideal laboratories in which to study star formation ; * the mid-infrared star formation rate estimator is as reliable as it is in spiral galaxies ; * the scatter in the estimation of star formation rates in various bands is similar to that of spiral galaxies and is mainly due to age effects ; * the combination of the extinction uncorrected Halpha line with mid-infrared yields a good estimation of the actual star formation rate ; * an important part of star formation, which can be as high as 85%, takes place in the intergalactic medium showing that in a young universe, in which this type of system is much more common than in the nearby universe, star formation from collisional debris can be an important factor of enrichment of

  10. Dark stars: a review.

    PubMed

    Freese, Katherine; Rindler-Daller, Tanja; Spolyar, Douglas; Valluri, Monica

    2016-06-01

    Dark stars are stellar objects made (almost entirely) of hydrogen and helium, but powered by the heat from dark matter annihilation, rather than by fusion. They are in hydrostatic and thermal equilibrium, but with an unusual power source. Weakly interacting massive particles (WIMPs), among the best candidates for dark matter, can be their own antimatter and can annihilate inside the star, thereby providing a heat source. Although dark matter constitutes only [Formula: see text]0.1% of the stellar mass, this amount is sufficient to power the star for millions to billions of years. Thus, the first phase of stellar evolution in the history of the Universe may have been dark stars. We review how dark stars come into existence, how they grow as long as dark matter fuel persists, and their stellar structure and evolution. The studies were done in two different ways, first assuming polytropic interiors and more recently using the MESA stellar evolution code; the basic results are the same. Dark stars are giant, puffy (∼10 AU) and cool (surface temperatures  ∼10 000 K) objects. We follow the evolution of dark stars from their inception at  ∼[Formula: see text] as they accrete mass from their surroundings to become supermassive stars, some even reaching masses  >[Formula: see text] and luminosities  >[Formula: see text], making them detectable with the upcoming James Webb Space Telescope. Once the dark matter runs out and the dark star dies, it may collapse to a black hole; thus dark stars may provide seeds for the supermassive black holes observed throughout the Universe and at early times. Other sites for dark star formation may exist in the Universe today in regions of high dark matter density such as the centers of galaxies. The current review briefly discusses dark stars existing today, but focuses on the early generation of dark stars.

  11. 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

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

    2014-01-01

    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. PMID:24874667

  12. Star formation regions in galaxies: Star complexes and spiral arms

    NASA Astrophysics Data System (ADS)

    Efremov, Iurii N.

    This book describes observational data on star formation regions (from young star clusters to spiral arms) in the Milky Way and other galaxies. It is concluded that not only high-luminosity stars but also star clusters and associations are forming together in vast complexes. It is claimed that these complexes are the primary, fundamental entities of star formation.

  13. The POR rs1057868–rs2868177 GC-GT diplotype is associated with high tacrolimus concentrations in early post-renal transplant recipients

    PubMed Central

    Liu, Shu; Chen, Rong-xin; Li, Jun; Zhang, Yu; Wang, Xue-ding; Fu, Qian; Chen, Ling-yan; Liu, Xiao-man; Huang, Hong-bing; Huang, Min; Wang, Chang-xi; Li, Jia-li

    2016-01-01

    Aim: Cytochrome P450 oxidoreductase (POR) is the only flavoprotein that donates electrons to all microsomal P450 enzymes (CYP), and several POR SNPs have been shown to be important contributors to altered CYP activity or CYP-mediated drug metabolism. In this study we examined the association between 6 POR SNPs and tacrolimus concentrations in Chinese renal transplant recipients. Methods: A total of 154 renal transplant recipients were enrolled. Genotyping of CYP3A5*3 and 6 POR SNPs was performed. All patients received a triple immunosuppressive regimen comprising tacrolimus, mycophenolate mofetil and prednisone. Dose-adjusted tacrolimus trough concentrations were obtained on d 7 (C0D7/D) after transplantation when steady-state concentration of tacrolimus was achieved (dosage had been unchanged for more than 3 d). Results: Tacrolimus C0D7/D in CYP3A5*3/*3/ POR rs1057868–rs2868177 GC-GT diplotype carriers was 1.62- and 2.72-fold higher than those in CYP3A5*3/*3/ POR rs1057868–rs2868177 GC-GT diplotype non-carriers and CYP3A5*1 carriers (220.17±48.09 vs 135.69±6.86 and 80.84±5.27 ng/mL/mg/kg, respectively, P<0.0001). Of CYP3A5*3/*3/ POR rs1057868-rs2868177GC-GT diplotype carriers, 85.71% exceeded the upper limit of the target range (8 ng/mL), which was also significantly higher compared with the latter two groups (14.29% and 0.00%, respectively, P<0.0001). The CYP3A5*3 and POR rs1057868–rs2868177 GC-GT diplotype explained 31.7% and 5.7%, respectively, of the inter-individual variability of tacrolimus C0D7/D, whereas the POR rs1057868–rs2868177 GC-GT diplotype could explain 10.9% of the inter-individual variability of tacrolimus C0D7/D in CYP3A5 non-expressers. Conclusion: The CYP3A5*3 and POR rs1057868–rs2868177 GC-GT diplotype accounted for the inter-individual variation of tacrolimus C0D7/D. Genotyping of POR rs1057868–rs2868177 diplotypes would help to differentiate initial tacrolimus dose requirements and to achieve early target C0 ranges in Chinese

  14. No association between the SNPs (rs3749446 and rs1402000) in the PARL gene and LHON in Chinese patients with m.11778G>A.

    PubMed

    Zhang, A-Mei; Jia, Xiaoyun; Zhang, Qingjiong; Yao, Yong-Gang

    2010-10-01

    According to a recent genome-wide linkage scan and association study of families with m.11778G>A in Thailand, two single nucleotide polymorphisms (SNPs) (rs3749446 and rs1402000) in the presenilins-associated rhomboid-like (PARL) gene were found to be associated with Leber hereditary optic neuropathy (LHON). In order to verify this association in Chinese LHON patients, we genotyped three PARL gene variants (rs3749446, rs953419, and rs1402000) in 179 patients with m.11778G>A and 170 patients with suspected LHON, and compared them to a control population containing the HapMap Chinese and 58 normal individuals analyzed in this study. We identified no association between these PARL gene SNPs and LHON in Chinese patients with m.11778G>A (P>0.05). Haplotype analysis also showed no statistical difference among the three Chinese populations.

  15. STAR in CTO PCI: When is STAR not a star?

    PubMed

    Hira, Ravi S; Dean, Larry S

    2016-04-01

    Subintimal tracking and reentry (STAR) has been used as a bailout strategy and involves an uncontrolled dissection and recanalization into the distal lumen to reestablish vessel patency. In the current study, thrombolysis in myocardial infarction (TIMI) flow < 3 was the only variable which they found to be significantly associated with restenosis and reocclusion after stent placement. It may be reasonable to consider second generation drug eluting stent placement in patients receiving STAR that have TIMI 3 flow, however, this should only be done if there is no compromise of major side branches. If unsure, we recommend to perform balloon angioplasty without stenting.

  16. The First Stars

    NASA Astrophysics Data System (ADS)

    Yoshida, Naoki

    2010-10-01

    The standard cosmological model predicts that the first cosmological objects are formed when the age of the universe is a few hundred million years. Recent theoretical studies and numerical simulations consistently suggest that the first objects are very massive primordial stars. We introduce the key physics and explain why the first stars are thought to be massive, rather than to be low-mass stars. The state-of-the-art simulations include all the relevant atomic and molecular physics to follow the thermal evolution of a prestellar gas cloud to very high ``stellar'' densities. Evolutionary calculations of the primordial stars suggest the formation of massive blackholes in the early universe. Finally, we show the results from high-resolution simulations of star formation in a low-metallicity gas. Vigorous fragmentation is triggered in a star-forming gas cloud at a metallicity of as low as Z = 10-5Zsolar.

  17. No relationship between most polymorphisms of steroidogenic acute regulatory (StAR) gene with polycystic ovarian syndrome

    PubMed Central

    Nazouri, Azadeh-Sadat; Khosravifar, Mona; Akhlaghi, Ali-Asghar; Shiva, Marzieh; Afsharian, Parvaneh

    2015-01-01

    Background: Polycystic ovary syndrome (PCOS) is one of the most common endocrine women’s disorders in reproductive age. Hyperandrogenism has a critical role in the etiology of PCOS and it can cause fault in Steroidogenesis process. During steroidogenesis, steroidogenic acute regulatory protein (StAR) seems to increase the delivery of cholesterol through mitochondrial membrane. Therefore, polymorphisms of StAR might effect on this protein and play a role in the etiology of PCOS. Objective: The aim of this study was to investigate the association between StAR SNPs with PCOS. Thus, seven polymorphisms in this gene: rs104894086, rs104894089, rs104894090, rs137852689, rs10489487, rs104894085 were detected. Materials and Methods: In this case control study, 45 PCOS women, 40 male factor/unexplained infertile women, and 40 fertile women as two control groups were participated from 2008-2012. Polymorphisms were detected using restriction fragment length polymorphism (PCR-RFLP) method. Results: Heterozygote genotyping for rs137852689 SNP (amino acid 218 C > T) was only seen in seven PCOS patients, one in normal ovulatory women, and five in male factor/unexplained infertile women (15.5%, 2.5%, 12.5%, respectively) (p= 0.12). While, it has shown no association between other SNPS with PCOs. Conclusion: The RFLP results for seven chosen SNPs, which located in exon 5 and 7 showed normal status in three groups, it means no heterozygous or homozygous forms of selected SNPs were observed. So, it seems evaluation of the active amino acid sites should be investigated and also the study population should be increased. PMID:27141537

  18. Chug and Dynamics of the RS-84 Subscale Preburner

    NASA Technical Reports Server (NTRS)

    Casiano, M. J; Morgan, C. J.; Scholten, N.

    2015-01-01

    The development of the RS-84 engine began in 2002 as part of the Space Launch Initiative. It was intended to be a reusable liquid oxygen/RP-1 booster engine of approximately 1 Mlbf thrust. Part of the test campaign consisted of testing subscale components to study key technologies such as oxygenrich, liquid oxygen/RP-1 combustion. In late 2003, the subscale preburner completed 4 hot-fire tests at Stennis Space Center with various hardware configurations and operating conditions, but before all planned tests could be completed the RS-84 engine development program was canceled in 2004. Recently, there has been a renewed interest in the development of an oxygen-rich, liquid oxygen/RP-1 combustion engine. Aerojet Rocketdyne and NASA completed testing of the subscale preburner in 2014 at Marshall Space Flight Center in an effort to better understand the chug encountered during the 2003 testing and to collect performance information over a wider range of operating conditions. The 2003 and 2014 data sets included extreme chug oscillations that reached nearly 200% of the chamber pressure and were reduced to well below 10% of the chamber pressure by incorporating a fuel orifice upstream of the fuel manifold. Depending on the hardware configuration and operating condition, a wide range of chug oscillation amplitudes were encountered. The dynamics for both test series were characterized and the data were used in the development of a chug model.

  19. IFITM3 Polymorphism rs12252-C Restricts Influenza A Viruses

    PubMed Central

    Grotefend, Christopher Robert; Radic, Vladimir; Chung, Changik; Chung, Young-Hwa; Farzan, Michael; Huang, I-Chueh

    2014-01-01

    The IFITM3 polymorphism rs12252-C, which encodes an IFITM3 isoform (Δ21 IFITM3) lacking 21 amino acids at the amino terminus, has been controversially associated with poor clinical outcomes in patients with H1N1 influenza A virus (IAV) infections. In vitro studies have shown that Δ21 IFITM3 loses its ability to restrict H1N1 IAV. Subsequent research has also revealed that tyrosine 20 is the key determinant for IFITM3 endocytic trafficking, which is essential for the efficient anti-viral activity of IFITM3. In contrast to previous studies, we demonstrated that both Δ21 IFITM3 and an IFITM3 variant (Y20A IFITM3), in which tyrosine 20 is substituted with alanine, strongly restricted entry mediated by IAV H1, H3, H5, and H7 proteins. Δ21 IFITM3 also efficiently suppressed replication of H1N1 and, to a lesser extent, H3N2 IAV. Δ21 IFITM3 and Y20A IFITM3 had broader subcellular distributions than full-length IFITM3 but an abundant amount of both IFITM3 variants still localized to late endosomes and lysosomes. Our data indicate that tyrosine 20 partially regulates the subcellular localization of IFITM3 but is not functionally essential for IFITM3-mediated IAV restriction. They also suggested that mechanisms, other than viral entry restriction, might contribute to variations in clinical outcomes of H1N1 influenza associated with rs12252-C. PMID:25314048

  20. STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C Polymorphisms Influence the Risk of Developing Juvenile Idiopathic Arthritis in Han Chinese Patients

    PubMed Central

    Fan, Zhi-Dan; Wang, Fei-Fei; Huang, Hui; Huang, Na; Ma, Hui-Hui; Guo, Yi-Hong; Zhang, Ya-Yuan; Qian, Xiao-Qing; Yu, Hai-Guo

    2015-01-01

    Juvenile idiopathic arthritis (JIA) is a common autoimmune disease characterized by environmental influences along with several predisposing genes in the pathogenesis. The protein tyrosine phosphatase nonreceptor 22 (PTPN22) and signal transducer and activator of transcription factor 4 (STAT4) have been recognized as susceptibility genes for numerous autoimmune diseases. Associations of STAT4 rs7574865 G/T and PTPN22 (rs2488457 G/C and rs2476601 C/T) polymorphisms with JIA have repeatedly been replicated in several Caucasian populations. The aim of this study was to investigate the influence of three polymorphisms mentioned above on the risk of developing JIA in Han Chinese patients. Genotyping was performed on a total of 137 Chinese patients with JIA (JIA group) and 150 sex and age frequency-matched healthy volunteers (Control group). The single-nucleotide polymorphisms (SNP) were determined by using direct sequencing of PCR-amplified products. There were significant differences of PTPN22 rs2488457 G/C and STAT4 rs7574865 G/T polymorphisms between both groups. However, no significant difference was observed in distribution frequencies of PTPN22 rs2476601 polymorphism. The association with the PTPN22 rs2488457 G/C polymorphism remained significant in the stratifications by age at onset, ANA status, splenomegaly, lymphadenectasis and involvement joints. As with the STAT4 rs7574865 G/T polymorphisms, the enthesitis-related arthritis and presence of hepatomegaly had strong effect on the association. Our data strengthen STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C polymorphisms as susceptibility factors for JIA. PMID:25781893

  1. An association study between DLGAP1 rs11081062 and EFNA5 rs26728 polymorphisms with obsessive–compulsive disorder in a Chinese Han population

    PubMed Central

    Li, Jiang; Cui, Jiajia; Wang, Xiuhai; Ma, Jianhua; Niu, Haitao; Ma, Xu; Zhang, Xinhua; Liu, Shiguo

    2015-01-01

    Background A recent genome-wide association study indicated that the single nucleotide polymorphisms (SNPs) rs11081062 in DLGAP1 and rs26728 in EFNA5 were associated with obsessive–compulsive disorder (OCD) in Caucasians. The present case–control association study assessed the global relevance of these two SNPs with respect to OCD subtypes in a Chinese Han population. Methods We recruited 320 OCD patients and 431 age- and sex-matched controls from a Chinese Han population. rs11081062 and rs26728 SNPs were genotyped by real-time TaqMan polymerase chain reaction, and the chi-squared test was used to compare allele and genotype frequencies of variants between the two groups. Results No significant differences were found in allele or genotype frequencies of DLGAP1 rs11081062 and EFNA5 rs26728 between the OCD and control groups. Moreover, consistently negative results were observed when classifying by sex, onset age, and comorbidity. However, on analyzing OCD subphenotypes, significant associations were observed between rs11081062 and the presence of contamination obsessions and cleaning compulsions (χ2=7.724, P=0.021 by genotype; χ2=3.745, P=0.053 by allele; and χ2=0.821, P=0.365 by genotype, χ2=27.809, P=0.000 by allele, respectively), and rs26728 with the presence of repeating compulsions (χ2=8.285, P=0.004 by genotype; χ2=7.512, P=0.006 by allele). Conclusion Although we found no association between DLGAP1 rs11081062 and EFNA5 rs26728 SNPs with OCD in a Chinese Han population, obvious associations were observed with OCD subphenotypes. Therefore, it appears to be useful to divide OCD into more homogeneous subphenotypes to help understand the complex genetic basis of this disorder. Further investigations are needed to replicate these findings using larger sample sizes, different populations, and other polymorphisms. PMID:25897225

  2. Non-Association between rs7903146 and rs12255372 Polymorphisms in Transcription Factor 7-Like 2 Gene and Type 2 Diabetes Mellitus in Jahrom City, Iran

    PubMed Central

    Pourahmadi, Mohammad; Moradzadeh, Malihe; Jahromi, Abdolreza Sotoodeh

    2015-01-01

    Background Transcription factor 7-like 2 (TCF7L2) is a transcription factor in the Wnt signaling pathway. High levels of TCF7L2 have been reported in most human tissues, including the heart, lung, brain, liver, kidney, placenta, adipose tissues, and pancreatic β-cells. The purpose of this study was to assess the association between TCF7L2 polymorphisms (rs12255372 and rs7903146) and type 2 diabetes mellitus in the city of Jahrom, Iran. Methods This case-control study was conducted with 200 patients referred to Diabetes Clinics and 200 healthy subjects in Jahrom City. Biochemical characteristics were first determined. TCF7L2 rs1255372 and rs7903146 polymorphisms were then genotyped using the polymerase chain reaction-restriction fragment length polymorphism method. Results T-allele frequencies of both single nucleotide polymorphisms (SNPs) were significantly higher in diabetic patients than in normal glucose-tolerant subjects (rs12255372: 20.3% vs. 14.5%; rs7903146: 28.5% vs. 22.25%). The rs12255372 (G/T) polymorphism analysis showed an odds ratio of 0.473 (95% confidence interval [CI], 0.170 to 1.314; P=0.151) for the TT genotype and 0.646 (95% CI, 0.410 to 1.019; P=0.060) for the TG genotype, compared with the GG genotype. The rs7903146 (C/T) polymorphism odds ratios for TT and TC genotypes were 0.564 (95% CI, 0.280 to 1.135; P=0.109) and 0.751 (95% CI, 0.487 to 1.157; P=0.194) compared with the CC genotype, respectively. Conclusion The rs12255372 and rs7903146 SNPs of the TCF7L2 gene were not associated with insulin resistance in the evaluated population. PMID:26616591

  3. A radio survey of weak T Tauri stars in Taurus-Auriga

    SciTech Connect

    O'neal, D.; Feigelson, E.D.; Mathieu, R.D.; Myers, P.C. Wisconsin Univ., Madison Harvard-Smithsonian Center for Astrophysics, Cambridge, MA )

    1990-11-01

    A multi-epoch 5 GHz survey of candidate or confirmed weak T Tauri stars in the Taurus-Auriga molecular cloud complex was conducted with the Very Large Array. The stars were chosen from those having detectable X-ray or chromospheric emission, and weak-emission-line pre-main-sequence stars found by other means. Snapshots of 99 VLA fields containing 119 candidate stars were obtained with a sensitivity of 0.7 mJy; most fields were observed on two or three dates. Nine radio sources coincident with cataloged stars were found. One may be an RS CVn binary system; the other eight are pre-main-sequence stars. Three of the detected stars - HD 283447, V410 Tau, and FK X-ray 1 - were previously known radio sources. Five new detections are Herbig's Anon 1, Hubble 4, HDE 283572, Elias 12, and HK Tau/c. At least five of the sources are variable, and no linear or circular polarization was found. Several lines of evidence suggest that the radio-detected weak T Tauri stars are quite young, perhaps younger on average than nondetected stars. 54 refs.

  4. Strange nonchaotic stars.

    PubMed

    Lindner, John F; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G; Ditto, William L

    2015-02-01

    The unprecedented light curves of the Kepler space telescope document how the brightness of some stars pulsates at primary and secondary frequencies whose ratios are near the golden mean, the most irrational number. A nonlinear dynamical system driven by an irrational ratio of frequencies generically exhibits a strange but nonchaotic attractor. For Kepler's "golden" stars, we present evidence of the first observation of strange nonchaotic dynamics in nature outside the laboratory. This discovery could aid the classification and detailed modeling of variable stars.

  5. Massive soliton stars

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1990-01-01

    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.

  6. Delta Scuti stars: Theory

    SciTech Connect

    Guzik, J.A.

    1998-03-01

    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.

  7. Massive soliton stars

    SciTech Connect

    Chiu, Hongyee )

    1990-05-01

    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. 27 refs.

  8. Introduction to neutron stars

    SciTech Connect

    Lattimer, James M.

    2015-02-24

    Neutron stars contain the densest form of matter in the present universe. General relativity and causality set important constraints to their compactness. In addition, analytic GR solutions are useful in understanding the relationships that exist among the maximum mass, radii, moments of inertia, and tidal Love numbers of neutron stars, all of which are accessible to observation. Some of these relations are independent of the underlying dense matter equation of state, while others are very sensitive to the equation of state. Recent observations of neutron stars from pulsar timing, quiescent X-ray emission from binaries, and Type I X-ray bursts can set important constraints on the structure of neutron stars and the underlying equation of state. In addition, measurements of thermal radiation from neutron stars has uncovered the possible existence of neutron and proton superfluidity/superconductivity in the core of a neutron star, as well as offering powerful evidence that typical neutron stars have significant crusts. These observations impose constraints on the existence of strange quark matter stars, and limit the possibility that abundant deconfined quark matter or hyperons exist in the cores of neutron stars.

  9. Strange Nonchaotic Stars

    NASA Astrophysics Data System (ADS)

    Lindner, John F.; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G.; Ditto, William L.

    2015-08-01

    Exploiting the unprecedented capabilities of the planet-hunting Kepler space telescope, which stared at 150 000 stars for four years, we discuss recent evidence that certain stars dim and brighten in complex patterns with fractal features. Such stars pulsate at primary and secondary frequencies whose ratios are near the famous golden mean, the most irrational number. A nonlinear system driven by an irrational ratio of frequencies is generically attracted toward a “strange” behavior that is geometrically fractal without displaying the “butterfly effect” of chaos. Strange nonchaotic attractors have been observed in laboratory experiments and have been hypothesized to describe the electrochemical activity of the brain, but a bluish white star 16 000 light years from Earth in the constellation Lyra may manifest, in the scale-free distribution of its minor frequency components, the first strange nonchaotic attractor observed in the wild. The recognition of stellar strange nonchaotic dynamics may improve the classification of these stars and refine the physical modeling of their interiors. We also discuss nonlinear analysis of other RR Lyrae stars in Kepler field of view and discuss some toy models for modeling these stars.References: 1) Hippke, Michael, et al. "Pulsation period variations in the RRc Lyrae star KIC 5520878." The Astrophysical Journal 798.1 (2015): 42.2) Lindner, John F., et al. "Strange nonchaotic stars." Phys. Rev. Lett. 114, 054101 (2015)

  10. Combinations of 148 navigation stars and the star tracker

    NASA Technical Reports Server (NTRS)

    Duncan, R.

    1980-01-01

    The angular separation of all star combinations for 148 nav star on the onboard software for space transportation system-3 flight and following missions is presented as well as the separation of each pair that satisfies the viewing constraints of using both star trackers simultaneously. Tables show (1) shuttle star catalog 1980 star position in M 1950 coordinates; (2) two star combination of 148 nav stars; and (3) summary of two star-combinations of the star tracker 5 deg filter. These 148 stars present 10,875 combinations. For the star tracker filters of plus or minus 5 deg, there are 875 combinations. Formalhaut (nav star 26) has the best number of combinations, which is 33.

  11. Creative implementation of 3Rs principles within industry programs: beyond regulations and guidelines.

    PubMed

    Bratcher, Natalie A; Reinhard, Gregory R

    2015-03-01

    The industry involved with using animals as an essential part of research has supported the theory and philosophy of the 3Rs for years. However, both the culture and approach surrounding the 3Rs is evolving rapidly, and many institutions are attempting to surpass the regulations and guidelines to implement the 3Rs for improved science and animal welfare. Regulatory documents and guidelines such as the Animal Welfare Act, the Guide for the Care and Use of Laboratory Animals, the Public Health Service Policy on Humane Care and Use of Laboratory Animals, and the US Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training clearly outline how the IACUC should address the 3Rs, but there are many additional paradigms and resources that an institution can use to promote the 3Rs creatively. We review the legal mandates and guidelines that institutions must or should follow, and we present some creative approaches toward their compliance, including the creation of full-time dedicated 3Rs roles as well as temporary 3Rs-focused positions such as visiting scientist and postdoctoral fellowships and internships. We also discuss how to creatively achieve 3Rs progress through internal committees and working groups, involvement in 3Rs consortia, recognizing 3Rs advances through awards programs, and creating 3Rs volunteer opportunities. Adherence to regulations and guidelines creates a solid foundation for good animal care and science, and creative 3Rs approaches enable the growth of a robust animal welfare culture that enhances the potential for 3Rs benefits to animals and science.

  12. Creative Implementation of 3Rs Principles within Industry Programs: Beyond Regulations and Guidelines

    PubMed Central

    Bratcher, Natalie A; Reinhard, Gregory R

    2015-01-01

    The industry involved with using animals as an essential part of research has supported the theory and philosophy of the 3Rs for years. However, both the culture and approach surrounding the 3Rs is evolving rapidly, and many institutions are attempting to surpass the regulations and guidelines to implement the 3Rs for improved science and animal welfare. Regulatory documents and guidelines such as the Animal Welfare Act, the Guide for the Care and Use of Laboratory Animals, the Public Health Service Policy on Humane Care and Use of Laboratory Animals, and the US Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training clearly outline how the IACUC should address the 3Rs, but there are many additional paradigms and resources that an institution can use to promote the 3Rs creatively. We review the legal mandates and guidelines that institutions must or should follow, and we present some creative approaches toward their compliance, including the creation of full-time dedicated 3Rs roles as well as temporary 3Rs-focused positions such as visiting scientist and postdoctoral fellowships and internships. We also discuss how to creatively achieve 3Rs progress through internal committees and working groups, involvement in 3Rs consortia, recognizing 3Rs advances through awards programs, and creating 3Rs volunteer opportunities. Adherence to regulations and guidelines creates a solid foundation for good animal care and science, and creative 3Rs approaches enable the growth of a robust animal welfare culture that enhances the potential for 3Rs benefits to animals and science. PMID:25836958

  13. Variable stars in the open cluster NGC 2141

    NASA Astrophysics Data System (ADS)

    Luo, Yang-Ping

    2015-05-01

    We report the results of a search for variable stars in the open cluster NGC 2141. Ten variable stars are detected, among which nine are new variable stars and they are classified as three short-period W UMa-type eclipsing binaries, two EA-type eclipsing binaries, one EB-type eclipsing binary, one very short-period RS CVn-type eclipsing binary, one d-type RR Lyrae variable star, and one unknown type of variable star. The membership and physical properties are discussed, based on their light curves, positions in the color magnitude diagrams, spatial locations and periods. A known EB-type eclipsing binary is also identified as a blue straggler candidate in the cluster. Furthermore, we find that all eclipsing contact binaries have prominent asymmetric eclipses and display the O'Connell effect, which increases with a decrease in orbital periods. This suggests that the O'Connell effect is probably related to the evolution of the orbital period in short period eclipsing binary systems. Supported by the National Natural Science Foundation of China.

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

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

    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.

  15. Chromospheric activity and rotational modulation of the RS Canum Venaticorum binary V711 Tauri during 1998-2004

    NASA Astrophysics Data System (ADS)

    Cao, Dongtao; Gu, Shenghong

    2015-05-01

    We present long-term high-resolution spectroscopic observations of the very active RS Canum Venaticorum-type star V711 Tau, obtained during several observing runs from 1998 to 2004, and study its chromospheric activity. Using the spectral subtraction technique, several optical chromospheric activity indicators [including the He I D3, Na I D1, D2, Hα and Ca II infrared triplet (IRT) lines] formed at different atmospheric heights are analysed. Strong chromospheric emission supports earlier results that indicate that V711 Tau is a very active system. Two large optical flares were detected during our observations. The results suggest that the main part of chromospheric emission is attributed to the primary star of the system. The secondary also presents weak emission but is less active. The ratios of EW8542/EW8498 indicate that Ca II IRT emission arises predominantly from plage-like regions. We have found rotational modulation of chromospheric activity in the Hα and Ca II IRT lines, which suggests the presence of the chromospheric active longitudes over the surface of V711 Tau. Two active longitudes separated by about 180° were observed to dominate the activity, and the so-called flip-flop phenomenon was seen during our observations. Moreover, the chromospheric activity level shows a long-term variation that gradually increases from a deep minimum near the year 2002. A close spatial connection of photospheric spots and chromospheric active regions in both short and long timescales was found for V711 Tau.

  16. GLOBAL STAR FORMATION REVISITED

    SciTech Connect

    Silk, Joseph; Norman, Colin E-mail: norman@stsci.edu

    2009-07-20

    A general treatment of disk star formation is developed from a dissipative multiphase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt (SK) law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and SK law residuals. The model is extended to include a multiphase treatment of supernova feedback that leads to a turbulent pressure-regulated generalization of the star formation law and is applicable to gas-rich starbursts. Enhanced pressure, as expected in merger-induced star formation, enhances star formation efficiency. An upper limit is derived for the disk star formation rate in starbursts that depends on the ratio of global ISM to cloud pressures. We extend these considerations to the case where the interstellar gas pressure in the inner galaxy is dominated by outflows from a central active galactic nucleus (AGN). During massive spheroid formation, AGN-driven winds trigger star formation, resulting in enhanced supernova feedback and outflows. The outflows are comparable to the AGN-boosted star formation rate and saturate in the super-Eddington limit. Downsizing of both SMBH and spheroids is a consequence of AGN-driven positive feedback. Bondi accretion feeds the central black hole with a specific accretion rate that is proportional to the black hole mass. AGN-enhanced star formation is mediated by turbulent pressure and relates spheroid star formation rate to black hole accretion rate. The relation between black hole mass and spheroid velocity dispersion has a coefficient (Salpeter time to gas consumption time ratio) that provides an arrow of time. Highly efficient, AGN-boosted star formation can occur at high redshift.

  17. The Pistol Star

    NASA Astrophysics Data System (ADS)

    Figer, Donald F.; Najarro, Francisco; Morris, Mark; McLean, Ian S.; Geballe, Thomas R.; Ghez, Andrea M.; Langer, Norbert

    1998-10-01

    We present new near-infrared data and analysis, which indicate that the Pistol Star is one of the most luminous stars known, adding another test point for massive star formation and stellar evolution theories. We estimate an extinction of AK = 3.2 +/- 0.5 using the near-infrared colors of the star and of surrounding stars in the young Quintuplet cluster. Using our wind/atmosphere code, we find two families of models that fit the spectral energy distribution and detailed line profiles. The lower luminosity models give L = 106.6+/-0.2 L⊙ and Teff = 104.15+/-0.01 K, while the higher luminosity models give L = 107.2+/-0.2 L⊙ and Teff = 104.33+/-0.01 K; the error in luminosity assumes an uncertainty of +/-0.5 in AK, while the error in Teff is constrained by detailed line modeling. The models also reveal a helium enriched surface. As previously existing stellar evolution models do not extend to such high luminosities, we employ new evolutionary tracks for very massive stars to determine the initial mass and age of the Pistol Star, and estimate Minitial = 200-250 M⊙ and an age of 1.7-2.1 Myr. The inferred luminosity and temperature place the star in a sparsely populated zone in the H-R diagram where luminous blue variables (LBVs) are often found. This is consistent with our evolutionary models, which predict that the star is in an unstable evolutionary stage. We interpret the star and its surrounding nebula as an LBV that has recently ejected large amounts of material. Our K-band speckle-imaging data reveal the star to be single down to a projected separation of 110 AU.

  18. Star Trek in the Schools

    ERIC Educational Resources Information Center

    Journal of Aerospace Education, 1977

    1977-01-01

    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)

  19. Observations of FK Comae stars

    NASA Technical Reports Server (NTRS)

    Bopp, B. W.

    1981-01-01

    Observations on the FK Comae stars are described. FK Com, UZ Lib and HD 199178 are compared and related as a group of stars. The crucial observational tests of the proposed evolutionary status of these stars are noted.

  20. Neutron Star Compared to Manhattan

    NASA Video Gallery

    A pulsar is a neutron star, the crushed core of a star that has exploded. Neutron stars crush half a million times more mass than Earth into a sphere no larger than Manhattan, as animated in this s...

  1. Stars and Flowers, Flowers and Stars

    NASA Astrophysics Data System (ADS)

    Minti, Hari

    2012-12-01

    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.

  2. Functional analysis of deep intronic SNP rs13438494 in intron 24 of PCLO gene.

    PubMed

    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

    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.

  3. Populations of Carbon Stars

    NASA Astrophysics Data System (ADS)

    Lloyd Evans, T.

    2011-09-01

    Carbon stars in the Galaxy do not constitute a single family, but may be divided over several types with distinctive spectroscopic and photometric properties. A subtype of the N stars, characterised by high velocities and weak CN bands, may have been captured by the Milky Way from a cannibalised dwarf galaxy.

  4. Modeling rapidly rotating stars

    NASA Astrophysics Data System (ADS)

    Rieutord, M.

    2006-06-01

    We review the quest of modeling rapidly rotating stars during the past 40 years and detail the challenges to be taken up by models facing new data from interferometry, seismology, spectroscopy... We then present the progress of the ESTER project aimed at giving a physically self-consistent model for the structure and evolution of rapidly rotating stars.

  5. Science through ARts (STAR)

    ERIC Educational Resources Information Center

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

    2005-01-01

    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…

  6. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  7. Party with the Stars.

    ERIC Educational Resources Information Center

    Blaine, Lloyd

    1997-01-01

    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)

  8. Science Through ARts (STAR)

    NASA Technical Reports Server (NTRS)

    Kolecki, Joseph; Petersen, Ruth; Williams, Lawrence

    2002-01-01

    Science Through ARts (STAR) is an educational initiative designed to teach students through a multidisciplinary approach to learning. This presentation describes the STAR pilot project, which will use Mars exploration as the topic to be integrated. Schools from the United Kingdom, Japan, the United States, and possibly eastern Europe are expected to participate in the pilot project.

  9. RS-A4 relaxation of flavor and CP violation

    NASA Astrophysics Data System (ADS)

    Kadosh, Avihay

    2013-03-01

    I discuss a model based on an A4 bulk flavor symmetry in the Randall-Sundrum (RS) setup. After discussing the setup and leading order results for the masses and mixings of quarks and leptons, I elaborate on the effect of higher order "cross-talk" corrections, their contributions to flavor violating processes and the resulting constraints on the model parameter space and the Kaluza-Klein (KK) mass scale. In addition, I present a systematic study of higher order corrections to the PMNS matrix in light of the recent measurements of θ 13 > 0 by RENO and Daya Bay. Finally, I also comment on the model new physics contributions to B_{s,d}toμ+μ^- and μ → eγ, in light of the new upper bounds recently set by the LHCb and MEG experiment.

  10. The obesity-associated polymorphisms FTO rs9939609 and MC4R rs17782313 and endometrial cancer risk in non-Hispanic white women.

    PubMed

    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

    2011-02-08

    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.

  11. Post-bronchiolitis wheezing is associated with toll-like receptor 9 rs187084 gene polymorphism.

    PubMed

    Nuolivirta, Kirsi; Törmänen, Sari; Teräsjärvi, Johanna; Vuononvirta, Juho; Koponen, Petri; Korppi, Matti; Helminen, Merja; Peltola, Ville; He, Qiushui

    2016-01-01

    Innate immunity receptors play a critical role in host defence, as well as in allergy and asthma. The aim of this exploratory study was to evaluate whether there are associations between TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and viral findings, clinical characteristics or subsequent wheezing in infants with bronchiolitis. In all, 135 full-term infants were hospitalized for bronchiolitis at age less than 6 months: 129 of them were followed-up until the age of 1.5 years. The outcome measures were repeated wheezing, use of inhaled corticosteroids, atopic dermatitis during the first 1.5 years of life and total serum immunoglobulin E (IgE). There were no significant associations between the genotypes or allele frequencies of TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and clinical characteristics or the severity of bronchiolitis during hospitalization. During follow-up, repeated wheezing was more common in children with TLR9 rs187084 variant genotype CC (30.5%) than in children with TLR9 wild-type genotype TT (12.2%) (p = 0.02, aOR 2.73, 95% CI 1.02-7.29). The TLR10 rs4129009 minor allele G was associated with elevated total serum IgE. TLR9 rs187084 gene polymorphism may be associated with post-bronchiolitis wheezing, and TLR10 rs4129009 gene polymorphism may be associated with atopy. PMID:27498757

  12. Post-bronchiolitis wheezing is associated with toll-like receptor 9 rs187084 gene polymorphism

    PubMed Central

    Nuolivirta, Kirsi; Törmänen, Sari; Teräsjärvi, Johanna; Vuononvirta, Juho; Koponen, Petri; Korppi, Matti; Helminen, Merja; Peltola, Ville; He, Qiushui

    2016-01-01

    Innate immunity receptors play a critical role in host defence, as well as in allergy and asthma. The aim of this exploratory study was to evaluate whether there are associations between TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and viral findings, clinical characteristics or subsequent wheezing in infants with bronchiolitis. In all, 135 full-term infants were hospitalized for bronchiolitis at age less than 6 months: 129 of them were followed-up until the age of 1.5 years. The outcome measures were repeated wheezing, use of inhaled corticosteroids, atopic dermatitis during the first 1.5 years of life and total serum immunoglobulin E (IgE). There were no significant associations between the genotypes or allele frequencies of TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and clinical characteristics or the severity of bronchiolitis during hospitalization. During follow-up, repeated wheezing was more common in children with TLR9 rs187084 variant genotype CC (30.5%) than in children with TLR9 wild-type genotype TT (12.2%) (p = 0.02, aOR 2.73, 95% CI 1.02–7.29). The TLR10 rs4129009 minor allele G was associated with elevated total serum IgE. TLR9 rs187084 gene polymorphism may be associated with post-bronchiolitis wheezing, and TLR10 rs4129009 gene polymorphism may be associated with atopy. PMID:27498757

  13. HypoxamiRs and Cancer: From Biology to Targeted Therapy

    PubMed Central

    Gee, Harriet E.; Ivan, Cristina; Calin, George A.

    2014-01-01

    Abstract Significance: Hypoxia is a hallmark of the tumor microenvironment and represents a major source of failure in cancer therapy. Recent Advances: Recent work has generated extensive evidence that microRNAs (miRNAs) are significant components of the adaptive response to low oxygen in tumors. Induction of specific miRNAs, collectively termed hypoxamiRs, has become an accepted feature of the hypoxic response in normal and transformed cells. Critical Issues: Overexpression of miR-210, the prototypical hypoxamiR, is detected in most solid tumors, and it has been linked to adverse prognosis in many tumor types. Several miR-210 target genes, including iron-sulfur (Fe-S) cluster scaffold protein (ISCU) and glycerol-3-phosphate dehydrogenase 1-like (GPD1L), have been correlated with prognosis in an inverse fashion to miR-210, suggesting that their down- regulation by miR-210 occurs in vivo and contributes to tumor growth. Additional miRNAs are modulated by decreased oxygen tension in a more tissue-specific fashion, adding another level of complexity over the classic hypoxia-regulated gene network. Future Directions: From a biological standpoint, hypoxamiRs are emerging modifiers of cancer cell response to the adaptive challenges of the microenvironment. From a clinical perspective, assessing the status of these miRNAs may contribute to a detailed understanding of hypoxia-induced mechanisms of resistance and/or to the fine-tuning of future hypoxia-modifying therapies. Antioxid. Redox Signal. 21, 1220–1238. PMID:24111776

  14. 'Marginal' BY Draconis stars

    NASA Technical Reports Server (NTRS)

    Bopp, Bernard W.

    1987-01-01

    Spectroscopic observations of 52 dK-dM stars, obtained at 640-665 nm (with spectral resolution 70-90 pm) using CCD detectors on the coude-feed telescope at KPNO since 1982, are reported. Data for four stars found to have diluted absorption or weak emission above continuum at H-alpha are presented in tables and spectra and discussed in detail. These objects (Gliese numbers 256, 425A, 900, and 907.1) are shown to be 'marginal' BY Dra stars, single objects of age 2.5-3 Gyr with activity and rotational velocity (3-5 km/s) between those of normal dM stars and those of true BY Dra stars. An explanation based on evolution from the BY Dra stage through marginal BY Dra to inactive dM is proposed.

  15. Producing Runaway Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-07-01

    How are the hypervelocity stars weve observed in our galaxy produced? A recent study suggests that these escapees could be accelerated by a massive black hole in the center of the Large Magellanic Cloud.A Black Hole SlingshotSince their discovery in 2005, weve observed dozens of candidate hypervelocity stars stars whose velocity in the rest frame of our galaxy exceeds the local escape velocity of the Milky Way. These stars present a huge puzzle: how did they attain these enormous velocities?One potential explanation is known as the Hills mechanism. In this process, a stellar binary is disrupted by a close encounter with a massive black hole (like those thought to reside at the center of every galaxy). One member of the binary is flung out of the system as a result of the close encounter, potentially reaching very large velocities.A star-forming region known as LHA 120-N 11, located within the LMC. Some binary star systems within the LMC might experience close encounters with a possible massive black hole at the LMCs center. [ESA/NASA/Hubble]Blame the LMC?Usually, discussions of the Hills mechanism assume that Sagittarius A*, the supermassive black hole at the center of the Milky Way, is the object guilty of accelerating the hypervelocity stars weve observed. But what if the culprit isnt Sgr A*, but a massive black hole at the center of the Large Magellanic Cloud (LMC), one of the Milky Ways satellite galaxies?Though we dont yet have evidence of a massive black hole at the center of the LMC, the dwarf galaxy is large enough to potentially host one as large as 100,000 solar masses. Assuming that it does, two scientists at the University of Cambridge, Douglas Boubert and Wyn Evans, have now modeled how this black hole might tear apart binary star systems and fling hypervelocity stars around the Milky Way.Models for AccelerationBoubert and Evans determined that the LMCs hypothetical black hole could easily eject stars at ~100 km/s, which is the escape velocity of the

  16. Abundances in Sagittarius Stars

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Zaggia, S.; Sbordone, L.; Santin, P.; Monaco, L.; Monai, S.; Molaro, P.; Marconi, G.; Girardi, L.; Ferraro, F.; di Marcantonio, P.; Caffau, E.; Bellazzini, M.

    The Sagittarius dwarf spheroidal is a very complex galaxy, which has undergone prolonged star formation. From the very first high resolution chemical analysis of Sgr stars, conducted using spectra obtained during the commissioning of UVES at VLT, it was clear that the star had undergone a high level of chemical processing, at variance with most of the other Local Group dwarf spheroidals. Thanks to FLAMES at VLT we now have accurate metallicities and abundances of alpha-chain elements for about 150 stars, which provide the first reliable metallicity distribution for this galaxy. Besides the already known high metallicity tail the existence of a metal-poor population has also been highlighted, although an assessment of the fraction of Sgr stars which belong to this population requires a larger sample. From our data it is also obvious that Sagittarius is a nucleated galaxy and that the centre of the nucleus coincides with M54, as already shown by Monaco et al.

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

    PubMed

    Schuppli, Catherine A; Fraser, David

    2005-10-01

    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.

  18. Complete genome sequence of a filamentous bacteriophage, RS611, that infects the phytopathogen Ralstonia solanacearum.

    PubMed

    Van, Truong Thi Bich; Yoshida, Shohei; Miki, Kaito; Kondo, Akihiro; Kamei, Kaeko

    2015-03-01

    Filamentous bacteriophage RS611 (ϕRS611), which infects the phytopathogen Ralstonia solanacearum, had a circular single-stranded DNA genome that was characterized as an Ff-type phage belonging to the family Inoviridae. The ϕRS611 genome was composed of 6386 bases with a G + C content of 62.1 % and contained 11 putative open reading frames. The ϕRS611 genome showed high similarity to those of Ralstonia phages RSS0 and RSS1. However, approximately 900-nucleotide deletions were found in the region corresponding to open reading frames 10 and 11 of ϕRSS0 and ϕRSS1.

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

    PubMed Central

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

    2013-01-01

    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

  20. BVR photometry and Hα spectroscopy of RS CVn type binary MM Herculis

    NASA Astrophysics Data System (ADS)

    Taš, G.; Evren, S.; Marino, G.; Frasca, A.; Ibanoǧlu, C.; Catalano, S.

    2001-09-01

    The RS CVn type eclipsing binary MM Herculis was observed photo-electrically using B, V and R filters in 1998 and 1999 and the light and colour curves were obtained. Spectroscopic observations were carried out in 1999. The new light and colour curves are anti-correlated with the observations of 1997, i.e. the system is bluer when it is faintest. The variations of the brightnesses at each special phase (0.0, 0.25, 0.5, and 0.75) show an almost cyclic change with a period of about 6 years. This value is in good agreement with the migration periods of the spots suggested by us previously. The outside-of-eclipse wave in the light curve shows a minimum at phase ~0.50, and the mean colour of the system is the bluest at the same phase. When the spots located on the cooler component are seen around phase 0.50, the amplitude of the light variation outside eclipse is larger than the others. Such variation may be caused by the effect of the hotter component. Spectroscopic observations of the system were carried out in the spectral range 5860-6700 Å. The subtraction of a ``synthetic'' spectrum, built up with spectra of inactive standard stars, allows us to detect an Hα emission excess only from the cool component. New radial velocity measurements of the system were obtained and analyzed for the orbital parameters. Based on observations collected at the Ege University Observatory, Turkey, and at the Catania Astrophysical Observatory, Italy.

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

    NASA Technical Reports Server (NTRS)

    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

    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

  2. Catch a Star!

    NASA Astrophysics Data System (ADS)

    2006-11-01

    ESO and the European Association for Astronomy Education are launching today the 2007 edition of 'Catch a Star!', their international astronomy competition for school students. Now in its fifth year, the competition offers students the chance to win a once-in-a-lifetime trip to ESO's flagship observatory in Chile, as well as many other prizes. Students are invited to 'become astronomers' and embark on a journey to explore the Universe. ESO PR Photo 42/06 The competition includes separate categories - 'Catch a Star Researchers' and 'Catch a Star Adventurers' - to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. For the artistically minded, 'Catch a Star!' also includes an artwork competition, 'Catch a Star Artists'. "'Catch a Star!' offers a unique opportunity for students to learn more about astronomy and about the methods scientists use to discover new things about the Universe", said Douglas Pierce-Price, Education Officer at ESO. In teams, students choose an astronomical topic to study and produce an in-depth report. An important part of the project for 'Catch a Star Researchers' is to think about how ESO's telescopes or a telescope of the future can contribute to their investigations of the subject. As well as the top prize - a trip to one of ESO's observatory sites in Chile - visits to observatories in Germany, Austria and Spain, and many other prizes are also available to be won. 'Catch a Star Researchers' winners will be chosen by an international jury, and 'Catch a Star Adventurers' will be awarded further prizes by lottery. Entries for 'Catch a Star Artists' will be displayed on the web and winners chosen with the help of a public online vote. The first editions of 'Catch a Star!' have attracted several hundred entries from more than 25 countries worldwide. Previous winning entries have included "Star clusters and the structure of the Milky Way" (Budapest, Hungary), "Vega" (Acqui Terme, Italy) and "Venus

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  4. Identification and frequency of the rs12516 and rs8176318 BRCA1 gene polymorphisms among different populations

    PubMed Central

    YANG, FANG; CHEN, FENGXIA; XU, JIN; GUAN, XIAOXIANG

    2016-01-01

    Genetic mutation of breast cancer 1 (BRCA1) is one of the most notable factors responsible for a proportion of breast cancer cases. BRCA1 encodes a 1,863-amino acid protein and functions as a negative regulator of tumor growth. Thus, investigation of the underlying mechanisms that regulate BRCA1 gene expression provide further insight into possible targets for breast cancer therapy. Previous studies have demonstrated that the genetic variants in the BRCA1 3′ untranslated region (3′UTR), in addition to the cytosine-phosphate-guanine (CpG) islands in the promoter region, are significantly associated with breast cancer risk; however, the role of single nucleotide polymorphisms (SNPs) in the BRCA1 3′UTR remains unclear. The present study aimed to investigate the association between SNPs and BRCA1 mRNA expression levels. Bioinformatics analysis demonstrated that 2 SNPs in the BRCA1 3′UTR (rs12516 and rs8176318 with putative microRNA binding sites) were significantly correlated with mRNA expression in lymphoblastoid cell lines (P=2.55×10-4 and P=8.78×10−5, respectively). Furthermore, the genotype frequency distribution varied between populations worldwide. In addition, 3 CpG islands and several transcription factor binding sites in the BRCA1 promoter region were established. The identification of such polymorphisms and CpG islands may aid in designing improved therapeutic strategies to treat patients with BRCA1-associated breast cancer. PMID:27073502

  5. Making star teams out of star players.

    PubMed

    Mankins, Michael; Bird, Alan; Root, James

    2013-01-01

    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

  6. A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study

    PubMed Central

    Spoutil, Frantisek; Vlcek, Miroslav; Krskova, Katarina; Penesova, Adela; Meskova, Milada; Marko, Andrea; Raslova, Katarina; Vohnout, Branislav; Rovensky, Jozef; Killinger, Zdenko; Jochmanova, Ivana; Lazurova, Ivica; Steiner, Guenter; Smolen, Josef; Imrich, Richard

    2016-01-01

    Introduction The aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA). Methods A total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA. Results HLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA. Conclusions The association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA. PMID:27092776

  7. Photometry and Spectroscopy of Short-Period Binary Stars in Four Old Open Clusters

    NASA Astrophysics Data System (ADS)

    Blake, R. M.; Rucinski, S. M.

    2004-12-01

    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. Our spectroscopic study of QX And in NGC 752 provided a distance modulus of (V - MV}){o = 8.30± 0.07 for this cluster. This compares to a value of (V - MV}){o = 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. 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 ˜ 1σ the values of 13.3 ≤ (V - MV) ≤ 13.42 obtained by isochrone fitting of the cluster CMD. EV Cnc in M67 did not yield a distance to the cluster from our procedure because of faintness of the system resulting in poor spectroscopic data. 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. R. M. Blake acknowledges the support of the Natural Science and Engineering Research Council of Canada through grants to S. M. Rucinski and C. T. Bolton.

  8. Pseudosynchronization of Heartbeat Stars

    NASA Astrophysics Data System (ADS)

    Zimmerman, Mara; Thompson, Susan E.; Hambleton, Kelly; Fuller, Jim; Shporer, Avi; Isaacson, Howard T.; Howard, Andrew; Kurtz, Donald

    2016-01-01

    A type of eccentric binary star that undergoes extreme dynamic tidal forces, known as Heartbeat stars, were discovered by the Kepler Mission. As the two stars pass through periastron, the tidal distortion causes unique brightness variations. Short period, eccentric binary stars, like these, are theorized to pseudosynchronize, or reach a rotational frequency that matches the weighted average orbital angular velocity of the system. This pseudosynchronous rate, as predicted by Hut (1981), depends on the binary's orbital period and eccentricity. We tested whether sixteen heartbeat stars have pseudosynchronized. We measure the rotation rate from obvious spot signatures in the light curve. We measure the eccentricity by fitting the light curve using PHOEBE and are actively carrying out a radial velocity monitoring program with Keck/HIRES in order to improve these orbital parameters. Our initial results show that while most heartbeat stars appear to have pseudosynchronized we find stars with rotation frequencies both longer and shorter than this rate. We thank the SETI Institute REU program, the NSF, and the Kepler Guest Observer Program for making this work possible.

  9. Dense Axion Stars

    NASA Astrophysics Data System (ADS)

    Mohapatra, Abhishek; Braaten, Eric; Zhang, Hong

    2016-03-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure. If the axion mass energy is mc2 =10-4 eV, these dilute axion stars have a maximum mass of about 10-14M⊙ . We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If mc2 =10-4 4 eV, the first branch of these dense axion stars has mass ranging from about 10-11M⊙ toabout M⊙.

  10. Association between Insulin-Like Growth Factor 1 Gene rs12423791 or rs6214 Polymorphisms and High Myopia: A Meta-Analysis

    PubMed Central

    Guo, Lan; Du, Xueying; Lu, Ciyong; Zhang, Wei-Hong

    2015-01-01

    Objective To evaluate the association of insulin-like growth factor 1 gene rs12423791 and rs6214 polymorphisms with high myopia. Methods An electronic search was conducted on PubMed, Embase, the Cochrane Library and the Chinese Biological Abstract Database for articles published prior to May 6, 2014. A meta-analysis was performed using Revman 5.1 and Stata 12.0, and the odds ratios with 95% confidence intervals were calculated in fixed or random effects models based on the results of the Q test. The subgroup analysis was conducted on the basis of the various regions, the sensitivity analysis was also performed to evaluate the stability of the results, and the publication bias was evaluated by a funnel plot and Egger’s linear regression analysis. Results This comprehensive meta-analysis included 2808 high myopia patients and 2778 controls from five unrelated studies. The results demonstrated that the significant association was not present in any genetic models between IGF-1 rs12423791 or rs6214 and high myopia. However, subgroup analysis indicated that rs12423791 polymorphism was associated with high myopia in the Chinese populations in the allelic contrast model (C vs. G: OR=1.24, 95% CI=1.04-1.48 in the fixed-effects model), the dominant model (CC+CG vs. GG: OR=1.40, 95% CI=1.16-1.69 in the fixed-effects model), and the codominant model (CG vs. GG: OR=1.37, 95% CI= 1.12-1.68 in the fixed-effects model). Additionally, none of the individual studies significantly affected the association between IGF-1 rs12423791 and high myopia, according to sensitivity analysis. Conclusion This meta-analysis shows that IGF-1 rs12423791 or rs6214 gene polymorphism is not associated with high myopia. PMID:26076017

  11. Association of the rs7903146 and rs12255372 polymorphisms in the TCF7L2 gene with type 2 diabetes in a population from northeastern Brazil.

    PubMed

    Barros, C M A R; Araujo-Neto, A P; Lopes, T R; Barros, M A L; Motta, F J N; Canalle, R; Nunes, L C C; Rey, J A; Burbano, R R; Lima-Barros, M A; Yoshioka, F K N; Pinto, G R

    2014-01-01

    Approximately 200 million people suffer from type 2 diabetes (T2D) worldwide, and the rapid increase in the prevalence of this disease is likely a result of multiple environmental factors, such as increased food intake and decreased physical activity in genetically predisposed individuals. Different population studies have demonstrated a strong association of two polymorphic variations in the TCF7L2 gene, the noncoding single nucleotide polymorphisms (SNPs) rs7903146 (C/T) and rs12255372 (G/T), with T2D. Herein, we analyzed the association of these SNPs with T2D in a population from northeastern Brazil. Our results showed that the genotype and allele frequencies in TCF7L2 rs7903146 and rs12255372 were similar in the patient and control groups (P > 0.05). In addition, the allele frequencies were not significantly associated with T2D risk [rs7903146: odds ratio (OR) = 0.95, 95% confidence interval (CI) = 0.52-1.76, P = 1.00, and rs12255372: OR = 1.38, 95%CI = 0.72-2.62, P = 0.41]. These data suggest that the TCF7L2 SNPs rs7903146 and rs12255372 may not significantly contribute to T2D susceptibility in this population. However, our results may reflect the small number of subjects. Alternatively, these results may be attributable to specific ethnic effects, as most of the previously reported associations were demonstrated with predominantly European populations. To reach a definitive conclusion on the role of such gene variants for T2D in mixed populations, additional efforts are necessary to replicate this study with larger populations from areas with more ethnic heterogeneity. PMID:25299103

  12. NEDD4 single nucleotide polymorphism rs2271289 is associated with keloids in Chinese Han population.

    PubMed

    Zhao, Ying; Liu, Sheng-Li; Xie, Jian; Ding, Mao-Qian; Lu, Meng-Zhu; Zhang, Lan-Fang; Yao, Xiu-Hua; Hu, Bai; Lu, Wen-Sheng; Zheng, Xiao-Dong

    2016-01-01

    Keloids are abnormally raised fibroproliferative lesions that usually occur following cutaneous traumas. Recently, a large-scale genome-wide association study (GWAS) has identified multiple single nucleotide polymorphisms (SNPs) in three genetic loci that are associated with keloids in Japanese population. Subsequently, two reported loci 1q41 (rs873549 and rs1442440) and 15q21.3 (rs2271289) for keloids were confirmed in selected Chinese population. The association of these SNPs with clinical features of keloids, has not yet been studied. To explore the role of these SNPs in the pathogenesis of keloids, we performed a case-controlled study in another independent Chinese Han population to analyze the correlation between 4 SNPs (rs873549, rs2118610, rs1511412, rs2271289) and keloids phenotypes. 309 keloids patients and 1080 control subjects were included. The results showed that, in the dominant mode of inheritance, the minor allele T of SNP rs2271289 had significantly higher odd ratios (ORs) in the severe keloid group compared with both the controls and the mild keloid group. The ORs were maintained after Bonferroni's correction (OR: 4.09, 95% CI: 1.78-9.37, P-value 3.25E-04). The ratio of the severe: mild OR for rs2271289 (dominant model) is (4.73/1.84=2.57). Similar associations in SNP rs2271289 were seen for groups with no family history and multiplesite compared with the control groups. No associations between keloid number, family history or severity relative to the controls were observed for the other three SNPs. Our data support that rs2271289 is strongly associated with severe keloids and might contribute to the complexity of clinical features of keloids. PMID:27158346

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

    PubMed Central

    Kirac, Iva; Matošević, Petar; Augustin, Goran; Šimunović, Iva; Hostić, Vedran; Župančić, Sven; Hayward, Caroline; Antoljak, Natasa; Rudan, Igor; Campbell, Harry; Dunlop, Malcolm G.; Velimir Vrdoljak, Danko; Kovačević, Dujo; Zgaga, Lina

    2013-01-01

    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. PMID:24066093

  14. Polymorphisms in TRPV1 and TAS2Rs associate with sensations from sampled ethanol

    PubMed Central

    Allen, Alissa L.; McGeary, John E.; Hayes, John E.

    2014-01-01

    Background Genetic variation in chemosensory genes can explain variability in individual’s perception of and preference for many foods and beverages. To gain insight into variable preference and intake of alcoholic beverages, we explored individual variability in the responses to sampled ethanol. In humans, ethanol elicits sweet, bitter and burning sensations. Here, we explore the relationship between variation in ethanol sensations and polymorphisms in genes encoding bitter taste receptors (TAS2Rs) and a polymodal nociceptor (TRPV1). Methods Caucasian participants (n=93) were genotyped for 16 SNPs in TRPV1, 3 SNPs in TAS2R38 and 1 SNP in TAS2R13. Participants rated sampled ethanol on a generalized Labeled Magnitude Scale. Two stimuli were presented: a 16% ethanol whole mouth sip-and-spit solution with a single time-point rating of overall intensity, and a cotton swab saturated with 50% ethanol on the circumvallate papillae (CV) with repeated ratings made over 3 minutes. Area under the curve (AUC) was calculated for the time-intensity data. Results The ethanol whole mouth solution had overall intensity ratings near ‘very strong’. Burning/stinging had the highest mean AUC values, followed by bitterness and sweetness. Whole mouth intensity ratings were significantly associated with burning/stinging and bitterness AUC values on the CV. Three TRPV1 SNPs (rs224547, rs4780521, rs161364) were associated with ethanol sensations on the CV, with two (rs224547 and rs4780521) exhibiting strong linkage disequilibrium. Additionally, the TAS2R38 SNPs rs713598, rs1726866, and rs10246939 formed a haplotype, and were associated with bitterness on the CV. Lastly, overall intensity for whole mouth ethanol associated with the TAS2R13 SNP rs1015443. Conclusions These data suggest genetic variations in TRPV1 and TAS2Rs influence sensations from sampled ethanol and may potentially influence how individuals initially respond to alcoholic beverages. PMID:25257701

  15. STARs in the CNS.

    PubMed

    Ehrmann, Ingrid; Fort, Philippe; Elliott, David J

    2016-08-15

    STAR (signal transduction and activation of RNA) proteins regulate splicing of target genes that have roles in neural connectivity, survival and myelination in the vertebrate nervous system. These regulated splicing targets include mRNAs such as the Neurexins (Nrxn), SMN2 (survival of motor neuron) and MAG (myelin-associated glycoprotein). Recent work has made it possible to identify and validate STAR protein splicing targets in vivo by using genetically modified mouse models. In this review, we will discuss the importance of STAR protein splicing targets in the CNS (central nervous system). PMID:27528753

  16. Strange nonchaotic stars.

    PubMed

    Lindner, John F; Kohar, Vivek; Kia, Behnam; Hippke, Michael; Learned, John G; Ditto, William L

    2015-02-01

    The unprecedented light curves of the Kepler space telescope document how the brightness of some stars pulsates at primary and secondary frequencies whose ratios are near the golden mean, the most irrational number. A nonlinear dynamical system driven by an irrational ratio of frequencies generically exhibits a strange but nonchaotic attractor. For Kepler's "golden" stars, we present evidence of the first observation of strange nonchaotic dynamics in nature outside the laboratory. This discovery could aid the classification and detailed modeling of variable stars. PMID:25699444

  17. Mariner 9 star photography.

    NASA Technical Reports Server (NTRS)

    Thorpe, T. E.

    1973-01-01

    Mariner 9 achieved successful photography of the stars, the purpose of the experiment being to measure camera parameters associated with point source photometry, and to examine the feasibility of using stars as invariant calibration sources and a reference for optical navigation. The Mariner 9 camera-B photography demonstrated photometric response consistency over a limited sample of data to better than 15%. Camera performance verified the ability to model vidicon response characteristics as well as demonstrated an imaging capability sufficient to permit the use of stars for photometric calibration.

  18. Association of the ACE rs4646994 and rs4341 polymorphisms with the progression of carotid atherosclerosis in slovenian patients with type 2 diabetes mellitus

    PubMed Central

    Merlo, S; Novák, J; Tkáčová, N; Nikolajević Starčević, J; Šantl Letonja, M; Makuc, J; Cokan Vujkovac, A; Letonja, J; Bregar, D; Zorc, M; Rojko, M; Mankoč, S; Kruzliak, P

    2015-01-01

    Abstract The current study was designed to reveal possible associations between the angiotensin-converting-enzyme (ACE) gene polymorphisms (rs4646994 and rs4341) with markers of carotid atherosclerosis in patients with type 2 diabetes mellitus (T2DM) in a 4-year-long follow-up study. Five hundred and ninety-five T2DM subjects and 200 control subjects were enrolled. Genotyping of ACE polymorphisms was performed using KASPar assays, and ultrasound examinations were performed twice (at the enrollment and at follow-up). With regard to the progression of atherosclerosis in subjects with T2DM, statistically significant differences were demonstrated in the change of the sum of carotid plaques thickness for the rs4646994 polymorphism. We did not demonstrate an association between the tested polymorphisms (rs4646994 and rs4341) and either carotid intima media thickness (CIMT) or CIMT progression in a 3.8-year period. In our study, we demonstrated that subjects with T2DM with the DD genotype of the rs4646994 [ACE insertion/deletion (I/D)] polymorphism had faster progression of atherosclerosis in comparison to subjects with other genotypes.

  19. Synergistic epistasis of paraoxonase 1 (rs662 and rs85460) and apolipoprotein E4 genes in pathogenesis of Alzheimer's disease and vascular dementia.

    PubMed

    Alam, Rizwan; Tripathi, Manjari; Mansoori, Nasim; Parveen, Shama; Luthra, Kalpana; Lakshmy, Ramakrishnan; Sharma, Subhadra; Arulselvi, Subramanian; Mukhopadhyay, Asok K

    2014-12-01

    Genetic polymorphism and epistasis play a role in etiopathogenesis of Alzheimer's disease (AD) and vascular dementia (VaD). In this case-control study, a total of 241 patients were included in the study to see the effect of paraoxonase 1 (PON1; rs662 and rs85460) and apolipoprotein E (ApoE) genes in altering the odds of having AD and VaD along with serum PON and lipid profile. The presence of at least 1 variant allele of rs662, but not rs85460, increased the risk of having AD by 1.8-fold (95% confidence interval [CI]: 0.97-3.40) and VaD by 3.09-fold (95% CI: 1.4-6.9). The interaction between PON1 genes (rs662 and rs85460) and ApoE genes showed synergistic epistasis in altering the odds of significantly having both AD and VaD. On the other hand, low serum level of high-density lipoprotein and low level of serum PON activity were found associated significantly (P ≤ .001 in both cases) only in patients with VaD as compared to healthy control.

  20. On the conversion of neutron stars into quark stars

    NASA Astrophysics Data System (ADS)

    Pagliara, Giuseppe

    2014-03-01

    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.

  1. Mass loss of massive stars

    NASA Astrophysics Data System (ADS)

    Martins, F.

    2015-12-01

    In this contribution we review the properties of the winds of massive stars. We focus on OB stars, red supergiants, Luminous Blue Variables (LBVs) and Wolf-Rayet stars. For each type of star, we summarize the main wind properties and we give a brief description of the physical mechanism(s) responsible for mass loss.

  2. Accurate Alpha Abundance and C/O of Low-mass Stars

    NASA Astrophysics Data System (ADS)

    Veyette, Mark; Muirhead, Philip; Mann, Andrew

    2015-01-01

    We investigate methods for measuring elemental abundances in M dwarf stars from high resolution (R>25,000), near-infrared spectra. With synthetic spectra from the BT-Settl model atmosphere library, we identify NIR features sensitive to enhancement of alpha elements (C, O, Mg, Si, S, Ca, and Ti) in M dwarfs. We also describe a method for measuring the amount of oxygen not bound in CO from molecular and atomic features in the NIR Y-band that, when combined with recently published methods of measuring carbon abundance in M dwarfs from K-band spectra, provides the ratio of carbon to oxygen (C/O). The ratio of carbon to oxygen is an important parameter for determining interior structures of exoplanets and processes that drive planet formation as evidenced by recent studies of the super Earth 55 Cnc e. We outline a potential observing program to empirically calibrate these methods via a sample of M dwarfs with widely-separated (5''-1500''), but associated, F, G or K-type binary companions. Once calibrated, we will apply these methods to a survey of nearby M dwarfs, including many stars that will be observed by NASA's Transiting Exoplanet Survey Satellite (TESS).

  3. Association between BDNF-rs6265 and obesity in the Boston Puerto Rican Health Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study is to examine a functional variant (rs6265) in the BDNF gene interacting with dietary intake modulate obesity traits in the Boston Puerto Rican Health Study population. BDNF rs6265 was genotyped in 1147 Puerto Ricans (aged 45-75 years), and examined for association with o...

  4. Identification of rs671, a common variant of ALDH2, as a gout susceptibility locus

    PubMed Central

    Sakiyama, Masayuki; Matsuo, Hirotaka; Nakaoka, Hirofumi; Yamamoto, Ken; Nakayama, Akiyoshi; Nakamura, Takahiro; Kawai, Sayo; Okada, Rieko; Ooyama, Hiroshi; Shimizu, Toru; Shinomiya, Nariyoshi

    2016-01-01

    Gout is a common disease resulting from hyperuricemia. Recently, a genome-wide association study identified an association between gout and a single nucleotide polymorphism (SNP) rs2188380, located on an intergenic region between MYL2 and CUX2 on chromosome 12. However, other genes around rs2188380 could possibly be gout susceptibility genes. Therefore, we performed a fine-mapping study of the MYL2-CUX2 region. From 8,595 SNPs in the MYL2-CUX2 region, 9 tag SNPs were selected, and genotyping of 1,048 male gout patients and 1,334 male controls was performed by TaqMan method. Eight SNPs showed significant associations with gout after Bonferroni correction. rs671 (Glu504Lys) of ALDH2 had the most significant association with gout (P = 1.7 × 10−18, odds ratio = 0.53). After adjustment for rs671, the other 8 SNPs no longer showed a significant association with gout, while the significant association of rs671 remained. rs671 has been reportedly associated with alcohol drinking behavior, and it is well-known that alcohol drinking elevates serum uric acid levels. These data suggest that rs671, a common functional SNP of ALDH2, is a genuine gout-associated SNP in the MYL2-CUX2 locus and that “A” allele (Lys) of rs671 plays a protective role in the development of gout. PMID:27181629

  5. The origin of stars

    NASA Astrophysics Data System (ADS)

    Smith, Michael D.

    Where do stars come from and how do they form? These are profound questions which link the nature of our Universe to the roots of mankind. Yet, until a recent revolution in understanding, the proposed answers have been raw speculation. Now, accompanying penetrating observations, a new picture has come into prominence. This book presents the latest astounding observations and scientific ideas covering star formation, star birth and early development. It encompasses all aspects, from the dramatic stories of individual objects, to the collective influence of entire stellar systems. The very first stars to come into existence and the nurturing of planets are discussed to provide the reader with a comprehensive overview. Presenting background information with only the essential mathematics, this book will appeal to scientists wishing to expand their horizons, students seeking solid foundations, and general readers with enquiring minds.

  6. Discovery of variable stars

    NASA Technical Reports Server (NTRS)

    Kurochkin, N. Y.

    1973-01-01

    Instrumented methods of discovering variable stars are reviewed, specifically the blink comparator, color contrast method, positive-negative method, and television method. Among the empirical methods discussed, the Van Gent method is the most important.

  7. Planets Around Neutron Stars

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  8. Winds from cool stars

    NASA Technical Reports Server (NTRS)

    Dupree, A. K.

    1995-01-01

    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.

  9. Cosmology with hypervelocity stars

    SciTech Connect

    Loeb, Abraham

    2011-04-01

    In the standard cosmological model, the merger remnant of the Milky Way and Andromeda (Milkomeda) will be the only galaxy remaining within our event horizon once the Universe has aged by another factor of ten, ∼ 10{sup 11} years after the Big Bang. After that time, the only extragalactic sources of light in the observable cosmic volume will be hypervelocity stars being ejected continuously from Milkomeda. Spectroscopic detection of the velocity-distance relation or the evolution in the Doppler shifts of these stars will allow a precise measurement of the vacuum mass density as well as the local matter distribution. Already in the near future, the next generation of large telescopes will allow photometric detection of individual stars out to the edge of the Local Group, and may target the ∼ 10{sup 5±1} hypervelocity stars that originated in it as cosmological tracers.

  10. Spectroscopy among the stars.

    PubMed

    Winnewisser, G

    1996-06-01

    The space between the stars is not void, but filled with interstellar matter, mainly composed of dust and gas, which gather in large interstellar clouds. In our Galaxy these interstellar clouds are distributed along a thin, but extended layer which basically traces out the spiral distribution of matter: the stars, the gas, and the dust component. Up to the present time more than 100 different molecules have been identified in interstellar molecular clouds. The majority of the interstellar molecules constitute carbon containing organic substances. During the past years, overwhelming evidence has been gathered, mainly through spectroscopic observations, that interstellar molecular clouds provide the birthplaces for stars. In fact detailed high spectral and spatial resolution spectroscopic measurements reveal physical and chemical processes of the intricate star formation process.

  11. Worlds around other stars

    NASA Astrophysics Data System (ADS)

    Black, David C.

    1991-01-01

    The possible, though tentative, detection of planetary companions to other stars which may be capable of supporting life as we know it through the use of a new generation of detectors and telescopes, combined with some innovative detection techniques, is discussed. The current view of the origin of the solar system, based on the nebular hypothesis, is discussed as it pertains to the formation of how and where planets form and, hence, how and where to search for them. Both direct methods of search for other planetary systems, which involve detecting reflected light or infrared radiation form the planets themselves, and indirect methods, which involve the scrutinization of a star for signs that it is responding to the gravitational tug of an orbiting planet, are discussed at length. In particular, various methods for detecting minute velocity perturbations of stars are discussed. It is noted that the study of brown dwarfs may also provide clues on the formation of stars and planets.

  12. Temperature of neutron stars

    NASA Astrophysics Data System (ADS)

    Tsuruta, Sachiko

    2016-07-01

    We start with a brief introduction to the historical background in the early pioneering days when the first neutron star thermal evolution calculations predicted the presence of neutron stars hot enough to be observable. We then report on the first detection of neutron star temperatures by ROSAT X-ray satellite, which vindicated the earlier prediction of hot neutron stars. We proceed to present subsequent developments, both in theory and observation, up to today. We then discuss the current status and the future prospect, which will offer useful insight to the understanding of basic properties of ultra-high density matter beyond the nuclear density, such as the possible presence of such exotic particles as pion condensates.

  13. Cooling of neutron stars

    NASA Technical Reports Server (NTRS)

    Pethick, C. J.

    1992-01-01

    It is at present impossible to predict the interior constitution of neutron stars based on theory and results from laboratory studies. It has been proposed that it is possible to obtain information on neutron star interiors by studying thermal radiation from their surfaces, because neutrino emission rates, and hence the temperature of the central part of a neutron star, depend on the properties of dense matter. The theory predicts that neutron stars cool relatively slowly if their cores are made up of nucleons, and cool faster if the matter is in an exotic state, such as a pion condensate, a kaon condensate, or quark matter. This view has recently been questioned by the discovery of a number of other processes that could lead to copious neutrino emission and rapid cooling.

  14. Women and the Stars.

    ERIC Educational Resources Information Center

    Spradley, Joseph L.

    1990-01-01

    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)

  15. r-Modes of Neutron Stars with Superfluid Cores

    NASA Astrophysics Data System (ADS)

    Lee, Umin; Yoshida, Shijun

    2003-03-01

    We investigate the modal properties of the r-modes of rotating neutron stars with the core filled with neutron and proton superfluids, taking account of entrainment effects between the superfluids. The stability of the r-modes against gravitational radiation reaction is also examined considering viscous dissipation due to shear and a damping mechanism called ``mutual friction'' between the superfluids in the core. We find that the r-modes in the superfluid core are split into ordinary r-modes and superfluid r-modes, which we call, respectively, ro- and rs-modes. The two superfluids in the core flow together for the ro-modes, while they countermove for the rs-modes. For the ro-modes, the coefficient κ0≡limΩ-->0ω/Ω is equal to 2m/[l'(l'+1)], almost independent of the parameter η that parameterizes the entrainment effects between the superfluids, where Ω is the angular frequency of rotation, ω is the oscillation frequency observed in the corotating frame of the star, and l' and m are the indices of the spherical harmonic function representing the angular dependence of the r-modes. For the rs-modes, on the other hand, κ0 is equal to 2m/[l'(l'+1)] at η=0 (no entrainment), and it almost linearly increases as η is increased from η=0. The ro-modes, for which w'≡v'p- v'n~Ω3, correspond to the r-modes discussed by L. Lindblom & G. Mendell, where v'n and v'p are the Eulerian velocity perturbations of the neutron and proton superfluids, respectively. The mutual friction in the superfluid core is found ineffective to stabilize the r-mode instability caused by the ro-mode except in a few narrow regions of η. The r-mode instability caused by the rs-modes, on the other hand, is extremely weak and easily damped by dissipative processes in the star.

  16. Sounds of a Star

    NASA Astrophysics Data System (ADS)

    2001-06-01

    Acoustic Oscillations in Solar-Twin "Alpha Cen A" Observed from La Silla by Swiss Team Summary Sound waves running through a star can help astronomers reveal its inner properties. This particular branch of modern astrophysics is known as "asteroseismology" . In the case of our Sun, the brightest star in the sky, such waves have been observed since some time, and have greatly improved our knowledge about what is going on inside. However, because they are much fainter, it has turned out to be very difficult to detect similar waves in other stars. Nevertheless, tiny oscillations in a solar-twin star have now been unambiguously detected by Swiss astronomers François Bouchy and Fabien Carrier from the Geneva Observatory, using the CORALIE spectrometer on the Swiss 1.2-m Leonard Euler telescope at the ESO La Silla Observatory. This telescope is mostly used for discovering exoplanets (see ESO PR 07/01 ). The star Alpha Centauri A is the nearest star visible to the naked eye, at a distance of a little more than 4 light-years. The new measurements show that it pulsates with a 7-minute cycle, very similar to what is observed in the Sun . Asteroseismology for Sun-like stars is likely to become an important probe of stellar theory in the near future. The state-of-the-art HARPS spectrograph , to be mounted on the ESO 3.6-m telescope at La Silla, will be able to search for oscillations in stars that are 100 times fainter than those for which such demanding observations are possible with CORALIE. PR Photo 23a/01 : Oscillations in a solar-like star (schematic picture). PR Photo 23b/01 : Acoustic spectrum of Alpha Centauri A , as observed with CORALIE. Asteroseismology: listening to the stars ESO PR Photo 23a/01 ESO PR Photo 23a/01 [Preview - JPEG: 357 x 400 pix - 96k] [Normal - JPEG: 713 x 800 pix - 256k] [HiRes - JPEG: 2673 x 3000 pix - 2.1Mb Caption : PR Photo 23a/01 is a graphical representation of resonating acoustic waves in the interior of a solar-like star. Red and blue

  17. The Pistol Star

    NASA Astrophysics Data System (ADS)

    Figer, D. F.; Morris, M.; McLean, I. S.; Ghez, A. M.; Najarro, F.; Geballe, T. R.; Serabyn, E.; Rich, R. M.

    1998-01-01

    We present near-infrared spectra, photometry (JHK(') nbL), and Keck K-band speckle images of the ``Pistol Star.'' We also present HST/NICMOS Paschen-alpha images and near-infrared spectra of the surrounding HII region (G0.15-0.05), the ``Pistol.'' The stellar spectra cover the J, H, and K bands at low resolution, and between 1.80 to 1.96 \\micron, 2.10 to 2.26 \\micron, and 4.02 to 4.08 \\micron\\ at moderate resolution. The spectra of the Pistol cover the K-band at low resolution and 1.80 to 1.96 \\micron\\ at moderate resolution. The stellar data are fit with wind/atmosphere models to find that the star is extraordinarily luminous, having L = 10(6.7({+0.5}_{-0.5})) L_sun, making it one of the most luminous stars known; the range in luminosity is primarily due to uncertainties in extinction and intrinsic spectral energy distribution of the star. Coupled with the relatively cool temperature, T_eff = 10(4.17({+0.19}_{-0.06})) K, the star is clearly in violation of the Humphreys-Davidson limit. The line of sight velocity of the star is confirmed to be ~ 130 kms(-1) , assuring membership in the Quintuplet cluster. This, along with the inferred extinction, places the star at the Galactic Center. The spectra of the Pistol confirm that the ionized gas has smoothly varying velocity gradients superposed on a bulk velocity of 130 kms(-1) . Radio and near-infrared hydrogen-to-helium line ratios suggest that the Pistol may have extrasolar helium abundance and that it must be excited, in part, by a star which is hotter than the Pistol Star. The morphology of the gas, the velocities in the gas, and the location of the star in the HR diagram suggest that the gas in G0.15-0.05 is matter which was ejected from the star.

  18. Catch a Star 2008!

    NASA Astrophysics Data System (ADS)

    2007-10-01

    ESO and the European Association for Astronomy Education have just launched the 2008 edition of 'Catch a Star', their international astronomy competition for school students. Now in its sixth year, the competition offers students the chance to win a once-in-a-lifetime trip to ESO's flagship observatory in Chile, as well as many other prizes. CAS logo The competition includes separate categories - 'Catch a Star Researchers' and 'Catch a Star Adventurers' - to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. In teams, students investigate an astronomical topic of their choice and write a report about it. An important part of the project for 'Catch a Star Researchers' is to think about how ESO's telescopes such as the Very Large Telescope (VLT) or future telescopes such as the Atacama Large Millimeter/submillimeter Array (ALMA) and the European Extremely Large Telescope (E-ELT) could contribute to investigations of the topic. Students may also include practical activities such as observations or experiments. For the artistically minded, 'Catch a Star' also offers an artwork competition, 'Catch a Star Artists'. Last year, hundreds of students from across Europe and beyond took part in 'Catch a Star', submitting astronomical projects and artwork. "'Catch a Star' gets students thinking about the wonders of the Universe and the science of astronomy, with a chance of winning great prizes. It's easy to take part, whether by writing about astronomy or creating astronomically inspired artwork," said Douglas Pierce-Price, Education Officer at ESO. As well as the top prize - a trip to ESO's Very Large Telescope in Chile - visits to observatories in Austria and Spain, and many other prizes, can also be won. 'Catch a Star Researchers' winners will be chosen by an international jury, and 'Catch a Star Adventurers' will be awarded further prizes by lottery. Entries for 'Catch a Star Artists' will be displayed on the web and winners

  19. Distinct role of the Fas rs1800682 and FasL rs763110 polymorphisms in determining the risk of breast cancer among Han Chinese females

    PubMed Central

    Wang, Meng; Wang, Zheng; Wang, Xi-Jing; Jin, Tian-Bo; Dai, Zhi-Ming; Kang, Hua-Feng; Guan, Hai-Tao; Ma, Xiao-Bin; Liu, Xing-Han; Dai, Zhi-Jun

    2016-01-01

    Background In recent years, studies have demonstrated that polymorphisms in the promoters of Fas and FasL are significantly associated with breast cancer risk. However, the results of these studies were inconsistent. This case–control study was performed to explore the associations between Fas rs1800682 and FasL rs763110 polymorphisms and breast cancer. Materials and methods A hospital-based case–control study of 560 Han Chinese females with breast cancer (583 controls) was conducted. The MassARRAY system was used to search for a possible association between the disease risk and the two single nucleotide polymorphisms, Fas rs1800682 and FasL rs763110. Statistical analyses were performed using SNPStats software to conduct Pearson’s chi-square tests in five different genetic models. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated after adjustment to age and body mass index. PHASE v2.1 software was used to reconstruct all common haplotypes. Results A statistically significant association was found between Fas rs1800682 and increased breast cancer risk (AG vs AA: OR =1.37, 95% CI =1.06–1.78; AA+AG vs GG: OR =1.32, 95% CI =1.04–1.66), and also it was found that the FasL rs763110 polymorphism may decrease the risk. Stratified analyses demonstrated that the rs763110 polymorphism was associated with lower breast cancer risk among postmenopausal females (heterozygote model: OR =0.69, 95% CI =0.49–0.97; dominant model: OR =0.70, 95% CI =0.51–0.96). The T allele of rs763110 was also associated with a decreased risk of lymph node metastasis (allele model: OR =0.75, 95% CI =0.57–0.97) and an increased risk of the breast cancer being human epidermal growth factor receptor 2 positive (allele model: OR =1.37, 95% CI =1.03–1.18). Moreover, haplotype analysis showed that Ars1800682Trs763110 was associated to a statistically significant degree with lower risk of breast cancer (OR =0.70, 95% CI =0.53–0.91). Conclusion These data suggest that

  20. Photometry of Variable Stars from the THU-NAOC Transient Survey. I. The First Two Years

    NASA Astrophysics Data System (ADS)

    Yao, Xinyu; Wang, Lingzhi; Wang, Xiaofeng; Zhang, Tianmeng; Chen, Juncheng; Yuan, Wenlong; Mo, Jun; Li, Wenxiong; Jin, Zhiping; Wu, Xuefeng; Nie, JunDan; Zhou, Xu

    2015-10-01

    In this paper, we report the detections of stellar variabilities from the first two years of observations of a sky area of about 1300 square degrees from the Tsinghua University–NAOC Transient Survey. A total of 1237 variable stars (including 299 new ones) were detected with a brightness <18.0 mag and a magnitude variation ≳0.1 mag on a timescale from a few hours to a few hundred days. Among such detections, we tentatively identified 661 RR Lyrae stars, 431 binaries, 72 semi-regular pulsators, 29 Mira stars, 11 slow irregular variables, 11 RS Canum Venaticorum stars, 7 Gamma Doradus stars, 5 long-period variables, 3 W Virginis stars, 3 Delta Scuti stars, 2 Anomalous Cepheids, 1 Cepheid, and 1 nova-like star based on their time-series variability index Js and their phased diagrams. Moreover, we found that 14 RR Lyrae stars show the Blazhko effect and 67 contact eclipsing binaries exhibit the O’Connell effect. Since the period and amplitude of light variations of RR Lyrae variables depend on their chemical compositions, their photometric observations can be used to investigate the distribution of metallicity along the direction perpendicular to the Galactic disk. We find that the metallicity of RR Lyrae stars shows large scatter at regions closer to the Galactic plane (e.g., ‑3.0 < [Fe/H] < 0) but tends to converge at [Fe/H] ∼ ‑1.7 at larger Galactic latitudes. This variation may be related to the fact that the RRAB Lyrae stars in the Galactic halo come from globular clusters with different metallicities and vertical distances, i.e., OoI and OoII populations, favoring the dual-halo model.

  1. Star of Bethlehem

    NASA Astrophysics Data System (ADS)

    Hughes, D.; Murdin, P.

    2001-07-01

    The biblical Star of Bethlehem, which heralded the birth of Jesus Christ, is only mentioned in the Gospel of St Matthew 2. The astrologically significant 7 bc triple conjunction of Jupiter and Saturn in the constellation of Pisces is the most likely candidate, although a comet/nova in 5 bc and a comet in 4 bc cannot be ruled out. There is also the possibility that the star was simply fictitious....

  2. Bubbly Little Star

    NASA Technical Reports Server (NTRS)

    2007-01-01

    In this processed Spitzer Space Telescope image, baby star HH 46/47 can be seen blowing two massive 'bubbles.' The star is 1,140 light-years away from Earth.

    The infant star can be seen as a white spot toward the center of the Spitzer image. The two bubbles are shown as hollow elliptical shells of bluish-green material extending from the star. Wisps of green in the image reveal warm molecular hydrogen gas, while the bluish tints are formed by starlight scattered by surrounding dust.

    These bubbles formed when powerful jets of gas, traveling at 200 to 300 kilometers per second, or about 120 to 190 miles per second, smashed into the cosmic cloud of gas and dust that surrounds HH 46/47. The red specks at the end of each bubble show the presence of hot sulfur and iron gas where the star's narrow jets are currently crashing head-on into the cosmic cloud's gas and dust material.

    Whenever astronomers observe a star, or snap a stellar portrait, through the lens of any telescope, they know that what they are seeing is slightly blurred. To clear up the blurring in Spitzer images, astronomers at the Jet Propulsion Laboratory developed an image processing technique for Spitzer called Hi-Res deconvolution.

    This process reduces blurring and makes the image sharper and cleaner, enabling astronomers to see the emissions around forming stars in greater detail. When scientists applied this image processing technique to the Spitzer image of HH 46/47, they were able to see winds from the star and jets of gas that are carving the celestial bubbles.

    This infrared image is a three-color composite, with data at 3.6 microns represented in blue, 4.5 and 5.8 microns shown in green, and 24 microns represented as red.

  3. Chaotic Star Birth

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [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.

  4. Spectroscopic Binary Stars

    NASA Astrophysics Data System (ADS)

    Batten, A.; Murdin, P.

    2000-11-01

    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...

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

    SciTech Connect

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

    1997-04-01

    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.

  6. The emerging landscape of circular RNA ciRS-7 in cancer (Review).

    PubMed

    Peng, Li; Yuan, Xiao Qing; Li, Guan Cheng

    2015-06-01

    Circular RNAs (circRNAs) are a novel class of non-coding RNA molecules ubiquitously present in the cytoplasm of eukaryotic cells. CircRNAs are generated from exons or introns via multiple mechanisms. A recently identified circRNA, ciRS-7, can regulate the activities of miRNAs, mRNAs, and RBP to exert specific biological effects. Also, ciRS-7 acts as a natural competing endogenous RNA, a.k.a. 'super sponge' of microRNA-7 (miR-7) that sequesters and competitively inhibits the activity of miR-7. This competition between ciRS-7 and miR-7 may have profound effects on oncogenesis. This review will summarize the origin and functions of ciRS-7 and discuss the relationship among ciRS-7, its target molecules and cancer. PMID:25873049

  7. The Stars Surrounding WR 55

    NASA Astrophysics Data System (ADS)

    Turner, David G.; Forbes, Douglas

    2005-09-01

    Photoelectric UBV photometry is presented for stars in a field closely adjacent to the Wolf-Rayet star WR 55 (WN7) in a search for a possible parent cluster. There is a group of at least eight stars ~7' south-southeast of the WR star forming a newly discovered, sparsely populated open cluster (designated C1331-622), but the stars are only 819+/-26 pc distant, less than a quarter of the predicted distance to WR 55.

  8. RASSF1A and the rs2073498 Cancer Associated SNP

    PubMed Central

    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

    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. PMID:22649770

  9. Photometric and Ca II H and K Spectroscopic Variations in Nearby Sun-like Stars with Planets. III.

    NASA Astrophysics Data System (ADS)

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

    2000-03-01

    We present the results of an analysis of time-series photometry, Ca II H and K spectrophotometry, and high-dispersion visible spectra of nine nearby Sun-like stars recently identified as having planets. For the six stars whose presumed planets have orbital periods of less than 4 months (τ Boo, 51 Peg, υ And, ρ1 Cnc, ρ CrB, and 70 Vir), sine-curve fits to the photometric data show no variations with semiamplitude greater than 1 or 2 parts in 104. Photometric variations in 47 UMa are similarly small, although our photometric data of this star are slightly affected by variability of the comparison star. Nonvariability at this level of precision is sufficient to rule out surface magnetic activity as the cause of the observed radial-velocity variations in these seven stars and makes nonradial pulsations unlikely as well. Thus, our photometry provides indirect but strong support for true reflex motions-planets-in these seven stars, but cannot yet so support the planetary hypothesis for the two additional stars, 16 Cyg B and Gl 411. Continued photometric monitoring of the short-period systems may soon result in the direct detection of these planets in reflected light. We have used our photometric fluxes to search for possible transits of the extrasolar planets. Transits definitely do not occur in τ Boo, 51 Peg, υ And, and ρ1 Cnc, and probably do not occur in ρ CrB and 70 Vir. Our transit-search results are inconclusive for 47 UMa, and we cannot address the issue for 16 Cyg B and Gl 411. The precision of our photometry is sufficient to detect transits of planets even if they are not gas giants, as currently assumed, but much smaller objects with rocky compositions. The chance of finding at least one transit in the six stars is ~40%. We find significant year-to-year photometric variability only in τ Boo, which is not only the youngest star in the sample but also the star with the shallowest convective zone. The interseasonal range in its yearly mean photometric

  10. STAR facility tritium accountancy

    SciTech Connect

    Pawelko, R. J.; Sharpe, J. P.; Denny, B. J.

    2008-07-15

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5 g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed. (authors)

  11. STAR Facility Tritium Accountancy

    SciTech Connect

    R. J. Pawelko; J. P. Sharpe; B. J. Denny

    2007-09-01

    The Safety and Tritium Applied Research (STAR) facility has been established to provide a laboratory infrastructure for the fusion community to study tritium science associated with the development of safe fusion energy and other technologies. STAR is a radiological facility with an administrative total tritium inventory limit of 1.5g (14,429 Ci) [1]. Research studies with moderate tritium quantities and various radionuclides are performed in STAR. Successful operation of the STAR facility requires the ability to receive, inventory, store, dispense tritium to experiments, and to dispose of tritiated waste while accurately monitoring the tritium inventory in the facility. This paper describes tritium accountancy in the STAR facility. A primary accountancy instrument is the tritium Storage and Assay System (SAS): a system designed to receive, assay, store, and dispense tritium to experiments. Presented are the methods used to calibrate and operate the SAS. Accountancy processes utilizing the Tritium Cleanup System (TCS), and the Stack Tritium Monitoring System (STMS) are also discussed. Also presented are the equations used to quantify the amount of tritium being received into the facility, transferred to experiments, and removed from the facility. Finally, the STAR tritium accountability database is discussed.

  12. Seeing Stars in Serpens

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Infant stars are glowing gloriously in this infrared image of the Serpens star-forming region, captured by NASA's Spitzer Space Telescope.

    The reddish-pink dots are baby stars deeply embedded in the cosmic cloud of gas and dust that collapsed to create it. A dusty disk of cosmic debris, or 'protoplanetary disk,' that may eventually form planets, surrounds the infant stars.

    Wisps of green throughout the image indicate the presence of carbon rich molecules called polycyclic aromatic hydrocarbons. On Earth, these molecules can be found on charred barbecue grills and in automobile exhaust. Blue specks sprinkled throughout the image are background stars in our Milky Way galaxy.

    The Serpens star-forming region is located approximately 848 light-years away in the Serpens constellation.

    The image is a three-channel, false-color composite, where emission at 4.5 microns is blue, emission at 8.0 microns is green, and 24 micron emission is red.

  13. Barium Stars: Theoretical Interpretation

    NASA Astrophysics Data System (ADS)

    Husti, Laura; Gallino, Roberto; Bisterzo, Sara; Straniero, Oscar; Cristallo, Sergio

    2009-09-01

    Barium stars are extrinsic Asymptotic Giant Branch (AGB) stars. They present the s-enhancement characteristic for AGB and post-AGB stars, but are in an earlier evolutionary stage (main sequence dwarfs, subgiants, red giants). They are believed to form in binary systems, where a more massive companion evolved faster, produced the s-elements during its AGB phase, polluted the present barium star through stellar winds and became a white dwarf. The samples of barium stars of Allen & Barbuy (2006) and of Smiljanic et al. (2007) are analysed here. Spectra of both samples were obtained at high-resolution and high S/N. We compare these observations with AGB nucleosynthesis models using different initial masses and a spread of 13C-pocket efficiencies. Once a consistent solution is found for the whole elemental distribution of abundances, a proper dilution factor is applied. This dilution is explained by the fact that the s-rich material transferred from the AGB to the nowadays observed stars is mixed with the envelope of the accretor. We also analyse the mass transfer process, and obtain the wind velocity for giants and subgiants with known orbital period. We find evidence that thermohaline mixing is acting inside main sequence dwarfs and we present a method for estimating its depth.

  14. Study on parallel and distributed management of RS data based on spatial database

    NASA Astrophysics Data System (ADS)

    Chen, Yingbiao; Qian, Qinglan; Wu, Hongqiao; Liu, Shijin

    2009-10-01

    With the rapid development of current earth-observing technology, RS image data storage, management and information publication become a bottle-neck for its appliance and popularization. There are two prominent problems in RS image data storage and management system. First, background server hardly handle the heavy process of great capacity of RS data which stored at different nodes in a distributing environment. A tough burden has put on the background server. Second, there is no unique, standard and rational organization of Multi-sensor RS data for its storage and management. And lots of information is lost or not included at storage. Faced at the above two problems, the paper has put forward a framework for RS image data parallel and distributed management and storage system. This system aims at RS data information system based on parallel background server and a distributed data management system. Aiming at the above two goals, this paper has studied the following key techniques and elicited some revelatory conclusions. The paper has put forward a solid index of "Pyramid, Block, Layer, Epoch" according to the properties of RS image data. With the solid index mechanism, a rational organization for different resolution, different area, different band and different period of Multi-sensor RS image data is completed. In data storage, RS data is not divided into binary large objects to be stored at current relational database system, while it is reconstructed through the above solid index mechanism. A logical image database for the RS image data file is constructed. In system architecture, this paper has set up a framework based on a parallel server of several common computers. Under the framework, the background process is divided into two parts, the common WEB process and parallel process.

  15. Accuracy Assessment and Correction of Vaisala RS92 Radiosonde Water Vapor Measurements

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    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.

  16. Collapsing Enormous Stars

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-09-01

    One of the big puzzles in astrophysics is how supermassive black holes (SMBHs) managed to grow to the large sizes weve observed in the very early universe. In a recent study, a team of researchers examines the possibility that they were formed by the direct collapse of supermassive stars.Formation MysterySMBHs billions of times as massive as the Sun have been observed at a time when the universe was less than a billion years old. But thats not enough time for a stellar-mass black hole to grow to SMBH-size by accreting material so another theory is needed to explain the presence of these monsters so early in the universes history. A new study, led by Tatsuya Matsumoto (Kyoto University, Japan), poses the following question: what if supermassive stars in the early universe collapsed directly into black holes?Previous studies of star formation in the early universe have suggested that, in the hot environment of these primordial times, stars might have been able to build up mass much faster than they can today. This could result in early supermassive stars roughly 100,000 times more massive than the Sun. But if these early stars end their lives by collapsing to become massive black holes in the same way that we believe massive stars can collapse to form stellar-mass black holes today this should result in enormously violent explosions. Matusmoto and collaborators set out to model this process, to determine what we would expect to see when it happens!Energetic BurstsThe authors modeled the supermassive stars prior to collapse and then calculated whether a jet, created as the black hole grows at the center of the collapsing star, would be able to punch out of the stellar envelope. They demonstrated that the process would work much like the widely-accepted collapsar model of massive-star death, in which a jet successfully punches out of a collapsing star, violently releasing energy in the form of a long gamma-ray burst (GRB).Because the length of a long GRB is thought to

  17. Association of IL28B SNPs rs12979860 and rs8099917 on Hepatitis C Virus-RNA Status in Donors/Recipients of Living Donor Liver Transplantation

    PubMed Central

    Nakano, Toshiaki; Chen, Kuang-Den; Lin, Chih-Che; Hu, Tsung-Hui; Goto, Shigeru; Chen, Chao-Long

    2016-01-01

    To investigate the effect of IL28B single nucleotide polymorphisms (SNPs) (rs8099917 and rs12979860) in the donors and recipients on the outcome of Hepatitis C virus-RNA clearance after living donor liver transplantation (LDLT). The rs8099917 and rs12979860 genotypes in 50 donor and recipients pairs were explored on the pre-operative day (POD) and post-operative day 30 (POD30). There was a significant difference in HCV-RNA clearance before (12%, 6/50) and after (48%, 24/50) liver transplantation (P < 0.001). The rs8099917 genotype TT was dominant in both the recipients (82%, 41/50) and donors (86%, 43/50), but had no significant effect on HCV-RNA clearance (87.5%, 21/24) and recurrence (76.9%, 20/26) after LDLT. One recipient was detected with genotype GG on POD, which changed to genotype GT on POD30. Prevalence of rs12979860 genotype CT was 98% (49/50 recipient) and 92% (46/50 donor) and prevalence of genotype CC was 2% (1/50 recipient) and 8% (4/50 donor) on POD and POD30, respectively. Of the 4 recipients with rs12979860 genotype CC on POD30, 3 recipients (12.5%, 3/24) exhibited HCV clearance and 1 experienced recurrence (3.9%, 1/26), however, this was not statistically significant. In conclusion, alterations in IL28B SNP genotype may occur after LDLT, leading to modifications in the host genome or donor proteome by HCV. This predicted mechanism will need to be investigated further. PMID:27275739

  18. Hot Subluminous Stars

    NASA Astrophysics Data System (ADS)

    Heber, U.

    2016-08-01

    Hot subluminous stars of spectral type B and O are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. Most hot subdwarf stars are chemically highly peculiar and provide a laboratory to study diffusion processes that cause these anomalies. The most obvious anomaly lies with helium, which may be a trace element in the atmosphere of some stars (sdB, sdO) while it may be the dominant species in others (He-sdB, He-sdO). Strikingly, the distribution in the Hertzsprung-Russell diagram of He-rich versus He-poor hot subdwarf stars of the globular clusters ω Cen and NGC 2808 differ from that of their field counterparts. The metal-abundance patterns of hot subdwarfs are typically characterized by strong deficiencies of some lighter elements as well as large enrichments of heavy elements. A large fraction of sdB stars are found in close binaries with white dwarf or very low-mass main sequence companions, which must have gone through a common-envelope (CE) phase of evolution. Because the binaries are detached they provide a clean-cut laboratory to study this important but yet poorly understood phase of stellar evolution. Hot subdwarf binaries with sufficiently massive white dwarf companions are viable candidate progenitors of type Ia supernovae both in the double degenerate as well as in the single degenerate scenario as helium donors for double detonation supernovae. The hyper-velocity He-sdO star US 708 may be the surviving donor of such a double detonation supernova. Substellar companions to sdB stars have also been found. For HW Vir systems the companion mass distribution extends from the stellar into the brown dwarf regime. A giant planet to the acoustic-mode pulsator V391 Peg was the first discovery of a planet that survived the red giant evolution of its host star. Evidence for Earth-size planets to two pulsating sdB stars have been reported and circumbinary giant planets or brown dwarfs have been found around HW

  19. Hot Subluminous Stars

    NASA Astrophysics Data System (ADS)

    Heber, U.

    2016-08-01

    Hot subluminous stars of spectral type B and O are core helium-burning stars at the blue end of the horizontal branch or have evolved even beyond that stage. Most hot subdwarf stars are chemically highly peculiar and provide a laboratory to study diffusion processes that cause these anomalies. The most obvious anomaly lies with helium, which may be a trace element in the atmosphere of some stars (sdB, sdO) while it may be the dominant species in others (He-sdB, He-sdO). Strikingly, the distribution in the Hertzsprung–Russell diagram of He-rich versus He-poor hot subdwarf stars of the globular clusters ω Cen and NGC 2808 differ from that of their field counterparts. The metal-abundance patterns of hot subdwarfs are typically characterized by strong deficiencies of some lighter elements as well as large enrichments of heavy elements. A large fraction of sdB stars are found in close binaries with white dwarf or very low-mass main sequence companions, which must have gone through a common-envelope (CE) phase of evolution. Because the binaries are detached they provide a clean-cut laboratory to study this important but yet poorly understood phase of stellar evolution. Hot subdwarf binaries with sufficiently massive white dwarf companions are viable candidate progenitors of type Ia supernovae both in the double degenerate as well as in the single degenerate scenario as helium donors for double detonation supernovae. The hyper-velocity He-sdO star US 708 may be the surviving donor of such a double detonation supernova. Substellar companions to sdB stars have also been found. For HW Vir systems the companion mass distribution extends from the stellar into the brown dwarf regime. A giant planet to the acoustic-mode pulsator V391 Peg was the first discovery of a planet that survived the red giant evolution of its host star. Evidence for Earth-size planets to two pulsating sdB stars have been reported and circumbinary giant planets or brown dwarfs have been found around HW

  20. Association of genetic variants in INS (rs689), INSR (rs1799816) and PP1G.G (rs1799999) with type 2 diabetes (T2D): a case-control study in three ethnic groups from North-West India.

    PubMed

    Sokhi, Jasmine; Sikka, Ruhi; Raina, Priyanka; Kaur, Ramandeep; Matharoo, Kawaljit; Arora, Punit; Bhanwer, Ajs

    2016-02-01

    Genetic contributions towards Type 2 diabetes (T2D) have been assessed through association studies across different world populations with inconsistencies. The majority of the T2D susceptibility loci are common across different races or populations but show ethnicity-specific differences. The pathogenesis of T2D involves genetic variants in the candidate genes. The interactions between the genes involved in insulin signaling and secretory pathways are believed to play an important role in determining an individual's susceptibility towards T2D. Therefore, the present study was initiated to examine the differences, if any, in the contribution of polymorphisms towards T2D susceptibility in the background of different ethnic specifications. The present case-control study included a total of 1216 T2D cases and healthy controls from three ethnic groups (Jat Sikhs, Banias and Brahmins) of North-West India. Polymorphisms were selected on the basis of information available in the literature for INS (rs689), INSR (rs1799816) and PP1G.G (rs1799999) in context to T2D. The genotyping was done using PCR-RFLP method. Statistical analysis was done using SPSS 16.0. The analyses revealed that INS (rs689) polymorphism conferred risk towards T2D susceptibility in all the three ethnic groups whereas INSR (rs1799816) polymorphism conferred risk towards T2D in Brahmins only and PP1G.G (rs1799999) polymorphism indicated T2D risk in Jat Sikhs only. Furthermore, interaction analyses indicated the cumulative role of three genetic variants in modulating T2D susceptibility in the three ethnic groups. In conclusion, our results substantiated the evidences for the role of ethnicity in differential susceptibility to T2D in the background of same genetic variants.

  1. The rs1024611 regulatory region polymorphism is associated with CCL2 allelic expression imbalance.

    PubMed

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

    2012-01-01

    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

  2. Magnetic fields in A stars besides Ap stars

    NASA Astrophysics Data System (ADS)

    Kochukhov, O.

    2014-11-01

    I review ongoing efforts to understand the incidence of magnetism in intermediate-mass stars that are different from the magnetic Ap stars. This includes the search for magnetic fields in chemically peculiar stars of the Am and HgMn types as well as in normal A and late-B stars. I discuss different techniques for detecting weak stellar magnetic fields, and present a critical evaluation of recent magnetic detections in non-Ap stars. Special attention is given to the magnetic status of HgMn stars and to the discovery of weak polarization signatures in Sirius and Vega.

  3. Long-term behaviour of starspots. III - Active longitudes on the long-period RS CVn star HK Lacertae

    NASA Technical Reports Server (NTRS)

    Olah, K.; Hall, D. S.; Henry, G. W.

    1991-01-01

    Thirteen years of photometry were used to study active longitudes on the surface of HK Lacertae. The decaying and forming phenomena of active areas in the years of 1980-1981, 1983-1984, and 1988-1989 are shown. New activity centers suddenly occur near the same orbital phase (0.6) and have lifetimes of several (greater than 6) years. The average rotational period of HK Lac is 24.2852 d; compared to the orbital period of 24.4284 d, this implies a 32 degree/year drift of the active areas on the stellar surface. Two possible interpretations for the period difference are discussed: pseudosynchronism and rigidity of magnetic patterns. The active longitudes on HK Lac are compared with similar phenomena found on the sun.

  4. A Systematic Search for Low-mass Field Stars with Large Infrared Excesses

    NASA Astrophysics Data System (ADS)

    Theissen, Christopher; West, Andrew A.

    2016-06-01

    We present a systematic search for low-mass field stars exhibiting extreme infrared (IR) excesses. One potential cause of the IR excess is the collision of terrestrial worlds. Our input stars are from the Motion Verified Red Stars (MoVeRS) catalog. Candidate stars are then selected based on large deviations (3σ) between their measured Wide-field Infrared Survey Explorer (WISE) 12 μm flux and their expected flux (as estimated from stellar models). We investigate the stellar mass and time dependence for stars showing extreme IR excesses, using photometric colors from the Sloan Digital Sky Survey (SDSS) and Galactic height as proxies for mass and time, respectively. Using a Galactic kinematic model, we estimate the completeness for our sample as a function of line-of-sight through the Galaxy, estimating the number of low-mass stars that should exhibit extreme IR excesses within a local volume. The potential for planetary collisions to occur over a large range of stellar masses and ages has serious implications for the habitability of planetary systems around low-mass stars.

  5. Association of ADORA1 rs2228079 and ADORA2A rs5751876 Polymorphisms with Gilles de la Tourette Syndrome in the Polish Population

    PubMed Central

    Safranow, Krzysztof; Żekanowski, Cezary

    2015-01-01

    Background Gilles de la Tourette syndrome (GTS) is a neurodevelopmental disorder characterized by motor and vocal tics. Hyperactivity of dopaminergic transmission is considered a prime abnormality in the pathophysiology of tics. There are reciprocal antagonistic interactions between adenosine and dopamine transmission. The aim of the study was to analyze the association of two polymorphisms, rs2228079 in ADORA1 and rs5751876 in ADORA2A, with the risk of GTS and co-morbid disorders. Material and Methods A total of 162 Polish GTS patients and 270 healthy persons were enrolled in the study. Two polymorphisms were selected on the basis of knowledge of SNPs frequencies in ADORA1 and ADORA2A. Chi-square test was used for allelic and genotypic association studies. Association of genotypes with age of tic onset was analyzed with Mann-Whitney test. Multivariate logistic regression was used to find independent predictors of GTS risk. Results We found that the risk of GTS was associated with rs2228079 and rs5751876 polymorphisms. The GG+GT genotypes of rs2228079 in ADORA1 were underrepresented in GTS patients (p = 0.011), whereas T allele of rs5751876 in ADORA2A was overrepresented (p = 0.017). The GG genotype of rs2228079 was associated with earlier age of tic onset (p = 0.046). We found also that the minor allele G of rs2228079 was more frequent in GTS patients with depression as compared to the patients without depression (p = 0.015). Also the genotype GG was significantly more frequent in patients with obsessive compulsive disorder/behavior (OCD/OCB, p = 0.021) and depression (p = 0.032), as compared to the patients without these co-morbidities. The minor allele T frequency of rs5751876 was lower in GTS patients with co-morbid attention deficit hyperactivity disorder (p = 0.022), and TT+TC genotypes were less frequent in the non-OCD anxiety disorder group (p = 0.045). Conclusion ADORA1 and ADORA2A variants are associated with the risk of GTS, co-morbid disorders, and may

  6. Life Cycle of Stars

    NASA Technical Reports Server (NTRS)

    1999-01-01

    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.

  7. Models of symbiotic stars

    NASA Technical Reports Server (NTRS)

    Friedjung, Michael

    1993-01-01

    One of the most important features of symbiotic stars is the coexistence of a cool spectral component that is apparently very similar to the spectrum of a cool giant, with at least one hot continuum, and emission lines from very different stages of ionization. The cool component dominates the infrared spectrum of S-type symbiotics; it tends to be veiled in this wavelength range by what appears to be excess emission in D-type symbiotics, this excess usually being attributed to circumstellar dust. The hot continuum (or continua) dominates the ultraviolet. X-rays have sometimes also been observed. Another important feature of symbiotic stars that needs to be explained is the variability. Different forms occur, some variability being periodic. This type of variability can, in a few cases, strongly suggest the presence of eclipses of a binary system. One of the most characteristic forms of variability is that characterizing the active phases. This basic form of variation is traditionally associated in the optical with the veiling of the cool spectrum and the disappearance of high-ionization emission lines, the latter progressively appearing (in classical cases, reappearing) later. Such spectral changes recall those of novae, but spectroscopic signatures of the high-ejection velocities observed for novae are not usually detected in symbiotic stars. However, the light curves of the 'symbiotic nova' subclass recall those of novae. We may also mention in this connection that radio observations (or, in a few cases, optical observations) of nebulae indicate ejection from symbiotic stars, with deviations from spherical symmetry. We shall give a historical overview of the proposed models for symbiotic stars and make a critical analysis in the light of the observations of symbiotic stars. We describe the empirical approach to models and use the observational data to diagnose the physical conditions in the symbiotics stars. Finally, we compare the results of this empirical

  8. Pioneering Better Science through the 3Rs: An Introduction to the National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs)

    PubMed Central

    Burden, Natalie; Chapman, Kathryn; Sewell, Fiona; Robinson, Vicky

    2015-01-01

    The National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs) is an independent scientific organization that is based in the United Kingdom, which was set up by the government to lead the discovery and application of new technologies and approaches that minimize the use of animals in research and improve animal welfare. The NC3Rs uses a range of strategies to improve and advance science through application of the 3Rs. These include funding basic research, open innovation (CRACK IT), and programs run by inhouse scientists. We present several case studies from the NC3Rs portfolio, featuring asthma research, the use of nonhuman primates in monoclonal antibody development, and CRACK IT. Finally, we anticipate the future, as we use our experience to move into new research fields and expand toward international collaboration. Here we highlight how equipping scientists with relevant and emerging 3Rs tools can help overcome the challenges and limitations of the use of animals in research to the benefit of the whole bioscience community. PMID:25836967

  9. Pioneering better science through the 3Rs: an introduction to the national centre for the replacement, refinement, and reduction of animals in research (NC3Rs).

    PubMed

    Burden, Natalie; Chapman, Kathryn; Sewell, Fiona; Robinson, Vicky

    2015-03-01

    The National Centre for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs) is an independent scientific organization that is based in the United Kingdom, which was set up by the government to lead the discovery and application of new technologies and approaches that minimize the use of animals in research and improve animal welfare. The NC3Rs uses a range of strategies to improve and advance science through application of the 3Rs. These include funding basic research, open innovation (CRACK IT), and programs run by inhouse scientists. We present several case studies from the NC3Rs portfolio, featuring asthma research, the use of nonhuman primates in monoclonal antibody development, and CRACK IT. Finally, we anticipate the future, as we use our experience to move into new research fields and expand toward international collaboration. Here we highlight how equipping scientists with relevant and emerging 3Rs tools can help overcome the challenges and limitations of the use of animals in research to the benefit of the whole bioscience community.

  10. Cephalopods in neuroscience: regulations, research and the 3Rs.

    PubMed

    Fiorito, Graziano; Affuso, Andrea; Anderson, David B; Basil, Jennifer; Bonnaud, Laure; Botta, Giovanni; Cole, Alison; D'Angelo, Livia; De Girolamo, Paolo; Dennison, Ngaire; Dickel, Ludovic; Di Cosmo, Anna; Di Cristo, Carlo; Gestal, Camino; Fonseca, Rute; Grasso, Frank; Kristiansen, Tore; Kuba, Michael; Maffucci, Fulvio; Manciocco, Arianna; Mark, Felix Christopher; Melillo, Daniela; Osorio, Daniel; Palumbo, Anna; Perkins, Kerry; Ponte, Giovanna; Raspa, Marcello; Shashar, Nadav; Smith, Jane; Smith, David; Sykes, António; Villanueva, Roger; Tublitz, Nathan; Zullo, Letizia; Andrews, Paul

    2014-03-01

    Cephalopods have been utilised in neuroscience research for more than 100 years particularly because of their phenotypic plasticity, complex and centralised nervous system, tractability for studies of learning and cellular mechanisms of memory (e.g. long-term potentiation) and anatomical features facilitating physiological studies (e.g. squid giant axon and synapse). On 1 January 2013, research using any of the about 700 extant species of "live cephalopods" became regulated within the European Union by Directive 2010/63/EU on the "Protection of Animals used for Scientific Purposes", giving cephalopods the same EU legal protection as previously afforded only to vertebrates. The Directive has a number of implications, particularly for neuroscience research. These include: (1) projects will need justification, authorisation from local competent authorities, and be subject to review including a harm-benefit assessment and adherence to the 3Rs principles (Replacement, Refinement and Reduction). (2) To support project evaluation and compliance with the new EU law, guidelines specific to cephalopods will need to be developed, covering capture, transport, handling, housing, care, maintenance, health monitoring, humane anaesthesia, analgesia and euthanasia. (3) Objective criteria need to be developed to identify signs of pain, suffering, distress and lasting harm particularly in the context of their induction by an experimental procedure. Despite diversity of views existing on some of these topics, this paper reviews the above topics and describes the approaches being taken by the cephalopod research community (represented by the authorship) to produce "guidelines" and the potential contribution of neuroscience research to cephalopod welfare.

  11. Brucella melitensis Methionyl-tRNA-Synthetase (MetRS), a Potential Drug Target for Brucellosis

    PubMed Central

    Ranade, Ranae M.; Zhang, Zhongsheng; Dranow, David M.; Myers, Janette B.; Choi, Ryan; Nakazawa Hewitt, Steve; Edwards, Thomas E.; Davies, Douglas R.; Lorimer, Donald; Boyle, Stephen M.; Barrett, Lynn K.; Buckner, Frederick S.; Fan, Erkang; Van Voorhis, Wesley C.

    2016-01-01

    We investigated Brucella melitensis methionyl-tRNA-synthetase (BmMetRS) with molecular, structural and phenotypic methods to learn if BmMetRS is a promising target for brucellosis drug development. Recombinant BmMetRS was expressed, purified from wild type Brucella melitensis biovar Abortus 2308 strain ATCC/CRP #DD-156 and screened by a thermal melt assay against a focused library of one hundred previously classified methionyl-tRNA-synthetase inhibitors of the blood stage form of Trypanosoma brucei. Three compounds showed appreciable shift of denaturation temperature and were selected for further studies on inhibition of the recombinant enzyme activity and cell viability against wild type B. melitensis strain 16M. BmMetRS protein complexed with these three inhibitors resolved into three-dimensional crystal structures and was analyzed. All three selected methionyl-tRNA-synthetase compounds inhibit recombinant BmMetRS enzymatic functions in an aminoacylation assay at varying concentrations. Furthermore, growth inhibition of B. melitensis strain 16M by the compounds was shown. Inhibitor-BmMetRS crystal structure models were used to illustrate the molecular basis of the enzyme inhibition. Our current data suggests that BmMetRS is a promising target for brucellosis drug development. However, further studies are needed to optimize lead compound potency, efficacy and safety as well as determine the pharmacokinetics, optimal dosage, and duration for effective treatment. PMID:27500735

  12. Brucella melitensis Methionyl-tRNA-Synthetase (MetRS), a Potential Drug Target for Brucellosis.

    PubMed

    Ojo, Kayode K; Ranade, Ranae M; Zhang, Zhongsheng; Dranow, David M; Myers, Janette B; Choi, Ryan; Nakazawa Hewitt, Steve; Edwards, Thomas E; Davies, Douglas R; Lorimer, Donald; Boyle, Stephen M; Barrett, Lynn K; Buckner, Frederick S; Fan, Erkang; Van Voorhis, Wesley C

    2016-01-01

    We investigated Brucella melitensis methionyl-tRNA-synthetase (BmMetRS) with molecular, structural and phenotypic methods to learn if BmMetRS is a promising target for brucellosis drug development. Recombinant BmMetRS was expressed, purified from wild type Brucella melitensis biovar Abortus 2308 strain ATCC/CRP #DD-156 and screened by a thermal melt assay against a focused library of one hundred previously classified methionyl-tRNA-synthetase inhibitors of the blood stage form of Trypanosoma brucei. Three compounds showed appreciable shift of denaturation temperature and were selected for further studies on inhibition of the recombinant enzyme activity and cell viability against wild type B. melitensis strain 16M. BmMetRS protein complexed with these three inhibitors resolved into three-dimensional crystal structures and was analyzed. All three selected methionyl-tRNA-synthetase compounds inhibit recombinant BmMetRS enzymatic functions in an aminoacylation assay at varying concentrations. Furthermore, growth inhibition of B. melitensis strain 16M by the compounds was shown. Inhibitor-BmMetRS crystal structure models were used to illustrate the molecular basis of the enzyme inhibition. Our current data suggests that BmMetRS is a promising target for brucellosis drug development. However, further studies are needed to optimize lead compound potency, efficacy and safety as well as determine the pharmacokinetics, optimal dosage, and duration for effective treatment. PMID:27500735

  13. Condensate dark matter stars

    SciTech Connect

    Li, X.Y.; Harko, T.; Cheng, K.S. E-mail: harko@hkucc.hku.hk

    2012-06-01

    We investigate the structure and stability properties of compact astrophysical objects that may be formed from the Bose-Einstein condensation of dark matter. Once the critical temperature of a boson gas is less than the critical temperature, a Bose-Einstein Condensation process can always take place during the cosmic history of the universe. Therefore we model the dark matter inside the star as a Bose-Einstein condensate. In the condensate dark matter star model, the dark matter equation of state can be described by a polytropic equation of state, with polytropic index equal to one. We derive the basic general relativistic equations describing the equilibrium structure of the condensate dark matter star with spherically symmetric static geometry. The structure equations of the condensate dark matter stars are studied numerically. The critical mass and radius of the dark matter star are given by M{sub crit} ≈ 2(l{sub a}/1fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2}M{sub s}un and R{sub crit} ≈ 1.1 × 10{sup 6}(l{sub a}/1 fm){sup 1/2}(m{sub χ}/1 GeV){sup −3/2} cm respectively, where l{sub a} and m{sub χ} are the scattering length and the mass of dark matter particle, respectively.

  14. Circulation of Stars

    NASA Astrophysics Data System (ADS)

    Boitani, P.

    2016-01-01

    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  15. Star Caught Smoking

    NASA Astrophysics Data System (ADS)

    2007-08-01

    VLTI Snapshots Dusty Puff Around Variable Star Using ESO's Very Large Telescope Interferometer, astronomers from France and Brazil have detected a huge cloud of dust around a star. This observation is further evidence for the theory that such stellar puffs are the cause of the repeated extreme dimming of the star. ESO PR Photo 34a/07 ESO PR Photo 34a/07 Dust Cloud in a R CrB Star (Artist's Impression) R Coronae Borealis stars are supergiants exhibiting erratic variability. Named after the first star that showed such behaviour [1], they are more than 50 times larger than our Sun. R Coronae Borealis stars can see their apparent brightness unpredictably decline to a thousandth of their nominal value within a few weeks, with the return to normal light levels being much slower. It has been accepted for decades that such fading could be due to obscuration of the stellar surface by newly formed dusty clouds. This 'Dust Puff Theory' suggests that mass is lost from the R Coronae Borealis (or R CrB for short) star and then moves away until the temperature is low enough for carbon dust to form. If the newly formed dust cloud is located along our line-of-sight, it eclipses the star. As the dust is blown away by the star's strong light, the 'curtain' vanishes and the star reappears. RY Sagittarii is the brightest member in the southern hemisphere of this family of weird stars. Located about 6,000 light-years away towards the constellation of Sagittarius (The Archer), its peculiar nature was discovered in 1895 by famous Dutch astronomer Jacobus Cornelius Kapteyn. In 2004, near-infrared adaptive optics observations made with NACO on ESO's Very Large Telescope allowed astronomers Patrick de Laverny and Djamel Mékarnia to clearly detect the presence of clouds around RY Sagittarii. This was the first direct confirmation of the standard scenario explaining the light variations of R CrB stars by the presence of heterogeneities in their envelope surrounding the star. ESO PR Photo 32e

  16. Nursery of New Stars

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This is a Hubble Space Telescope image (right) of a vast nebula called NGC 604, which lies in the neighboring spiral galaxy M33, located 2.7 million light-years away in the constellation Triangulum. This is a site where new stars are being born in a spiral arm of the galaxy. Though such nebulae are common in galaxies, this one is particularly large, nearly 1,500 light-years across. The nebula is so vast it is easily seen in ground-based telescopic images (left). At the heart of NGC 604 are over 200 hot stars, much more massive than our Sun (15 to 60 solar masses). They heat the gaseous walls of the nebula making the gas fluoresce. Their light also highlights the nebula's three-dimensional shape, like a lantern in a cavern. By studying the physical structure of a giant nebula, astronomers may determine how clusters of massive stars affect the evolution of the interstellar medium of the galaxy. The nebula also yields clues to its star formation history and will improve understanding of the starburst process when a galaxy undergoes a 'firestorm' of star formation. The image was taken on January 17, 1995 with Hubble's Wide Field and Planetary Camera 2. Separate exposures were taken in different colors of light to study the physical properties of the hot gas (17,000 degrees Fahrenheit, 10,000 degrees Kelvin

  17. Origin of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Brecher, K.

    1999-12-01

    The origin of the concept of neutron stars can be traced to two brief, incredibly insightful publications. Work on the earlier paper by Lev Landau (Phys. Z. Sowjetunion, 1, 285, 1932) actually predated the discovery of neutrons. Nonetheless, Landau arrived at the notion of a collapsed star with the density of a nucleus (really a "nucleus star") and demonstrated (at about the same time as, and independent of, Chandrasekhar) that there is an upper mass limit for dense stellar objects of about 1.5 solar masses. Perhaps even more remarkable is the abstract of a talk presented at the December 1933 meeting of the American Physical Society published by Walter Baade and Fritz Zwicky in 1934 (Phys. Rev. 45, 138). It followed the discovery of the neutron by just over a year. Their report, which was about the same length as the present abstract: (1) invented the concept and word supernova; (2) suggested that cosmic rays are produced by supernovae; and (3) in the authors own words, proposed "with all reserve ... the view that supernovae represent the transitions from ordinary stars to neutron stars (italics), which in their final stages consist of extremely closely packed neutrons." The abstract by Baade and Zwicky probably contains the highest density of new, important (and correct) ideas in high energy astrophysics ever published in a single paper. In this talk, we will discuss some of the facts and myths surrounding these two publications.

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

    PubMed Central

    2014-01-01

    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. PMID:24906453

  19. TERT promoter mutations and rs2853669 polymorphism: prognostic impact and interactions with common alterations in glioblastomas.

    PubMed

    Nencha, Umberto; Rahimian, Amithys; Giry, Marine; Sechi, Andrea; Mokhtari, Karima; Polivka, Marc; Schmitt, Yohann; Di Stefano, Anna-Luisa; Alentorn, Agusti; Labussière, Marianne; Sanson, Marc

    2016-02-01

    TERT promoter (TERTp) mutation is the most common mutation in glioblastomas. It creates a putative binding site for Ets/TCF transcription factors, enhancing telomerase expression and activity, whereas the rs2853669 variant disrupts another Ets/TCF binding. We explore here the interaction between these two alterations, tumor genomic profile and the impact on prognosis. The TERTp and rs2853669 statuses were determined and confronted with the outcome and molecular profile, i.e., loss of chromosome 10q, CDKN2A deletion, IDH mutation, EGFR amplification, MGMT promoter methylation. 651 glioblastomas were selected (sex ratio = 1.35, median age 60.4 years, median survival 13.5 months). The TERTp mutation found in 481 patients (74 %) was independent from rs2853669 genotypes. TERTp mutation, but not rs2853669 status, was associated with older age (61.4 vs. 52.8 years). rs2853669 status had no impact on overall survival (OS) either in mutated TERTp or wild-type TERTp. Neither rs2736100 (TERT, 5q15.33) nor rs192011116 (TERC, 3q26.2) status had any impact on survival or showed any association with a TERTp mutation. The TERTp mutation was associated with EGFR amplification chromosome 10q loss, CDKN2A deletion and IDH wt. EGFR amplification was associated with a better outcome in TERTp mutated GBM, and a worse outcome in TERTp WT. This study-the largest analyzing the TERTp mutation and the rs2853669 polymorphism-fails to find any prognostic impact of rs2853669. It confirms the dual prognostic impact of EGFR amplification depending on TERTp status. PMID:26608520

  20. Expression of the CLE-RS3 gene suppresses root nodulation in Lotus japonicus.

    PubMed

    Nishida, Hanna; Handa, Yoshihiro; Tanaka, Sachiko; Suzaki, Takuya; Kawaguchi, Masayoshi

    2016-09-01

    Cell-to-cell communication, principally mediated by short- or long-range mobile signals, is involved in many plant developmental processes. In root nodule symbiosis, a mutual relationship between leguminous plants and nitrogen-fixing rhizobia, the mechanism for the autoregulation of nodulation (AON) plays a key role in preventing the production of an excess number of nodules. AON is based on long-distance cell-to-cell communication between roots and shoots. In Lotus japonicus, two CLAVATA3/ESR-related (CLE) peptides, encoded by CLE-ROOT SIGNAL 1 (CLE-RS1) and -RS2, act as putative root-derived signals that transmit signals inhibiting further nodule development through interaction with a shoot-acting receptor-like kinase HYPERNODULATION ABERRANT ROOT FORMATION 1 (HAR1). Here, an in silico search and subsequent expression analyses enabled us to identify two new L. japonicus CLE genes that are potentially involved in nodulation, designated as CLE-RS3 and LjCLE40. Time-course expression patterns showed that CLE-RS1/2/3 and LjCLE40 expression is induced during nodulation with different activation patterns. Furthermore, constitutive expression of CLE-RS3 significantly suppressed nodule formation in a HAR1-dependent manner. TOO MUCH LOVE, a root-acting regulator of AON, is also required for the CLE-RS3 action. These results suggest that CLE-RS3 is a new component of AON in L. japonicus that may act as a potential root-derived signal through interaction with HAR1. Because CLE-RS2, CLE-RS3 and LjCLE40 are located in tandem in the genome and their expression is induced not only by rhizobial infection but also by nitrate, these genes may have duplicated from a common gene. PMID:27294965

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

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Burnside, Christopher G.

    2013-01-01

    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

  2. Heavy Metal Stars

    NASA Astrophysics Data System (ADS)

    2001-08-01

    La Silla Telescope Detects Lots of Lead in Three Distant Binaries Summary Very high abundances of the heavy element Lead have been discovered in three distant stars in the Milky Way Galaxy . This finding strongly supports the long-held view that roughly half of the stable elements heavier than Iron are produced in common stars during a phase towards the end of their life when they burn their Helium - the other half results from supernova explosions. All the Lead contained in each of the three stars weighs about as much as our Moon. The observations show that these "Lead stars" - all members of binary stellar systems - have been more enriched with Lead than with any other chemical element heavier than Iron. This new result is in excellent agreement with predictions by current stellar models about the build-up of heavy elements in stellar interiors. The new observations are reported by a team of Belgian and French astronomers [1] who used the Coude Echelle Spectrometer on the ESO 3.6-m telescope at the La Silla Observatory (Chile). PR Photo 26a/01 : A photo of HD 196944 , one of the "Lead stars". PR Photo 26b/01 : A CES spectrum of HD 196944 . The build-up of heavy elements Astronomers and physicists denote the build-up of heavier elements from lighter ones as " nucleosynthesis ". Only the very lightest elements (Hydrogen, Helium and Lithium [2]) were created at the time of the Big Bang and therefore present in the early universe. All the other heavier elements we now see around us were produced at a later time by nucleosynthesis inside stars. In those "element factories", nuclei of the lighter elements are smashed together whereby they become the nuclei of heavier ones - this process is known as nuclear fusion . In our Sun and similar stars, Hydrogen is being fused into Helium. At some stage, Helium is fused into Carbon, then Oxygen, etc. The fusion process requires positively charged nuclei to move very close to each other before they can unite. But with increasing

  3. Neutron star crusts

    NASA Technical Reports Server (NTRS)

    Lorenz, C. P.; Ravenhall, D. G.; Pethick, C. J.

    1993-01-01

    We calculate properties of neutron star matter at subnuclear densities using an improved nuclear Hamiltonian. Nuclei disappear and the matter becomes uniform at a density of about 0.6n(s), where n(s) of about 0.16/cu fm is the saturation density of nuclear matter. As a consequence, the mass of matter in the crusts of neutron stars is only about half as large as previously estimated. In about half of that crustal mass, nuclear matter occurs in shapes very different from the roughly spherical nuclei familiar at lower densities. The thinner crust and the unusual nuclear shape have important consequences for theories of the rotational and thermal evolution of neutron stars, especialy theories of glitches.

  4. GRACE star camera noise

    NASA Astrophysics Data System (ADS)

    Harvey, Nate

    2016-08-01

    Extending results from previous work by Bandikova et al. (2012) and Inacio et al. (2015), this paper analyzes Gravity Recovery and Climate Experiment (GRACE) star camera attitude measurement noise by processing inter-camera quaternions from 2003 to 2015. We describe a correction to star camera data, which will eliminate a several-arcsec twice-per-rev error with daily modulation, currently visible in the auto-covariance function of the inter-camera quaternion, from future GRACE Level-1B product releases. We also present evidence supporting the argument that thermal conditions/settings affect long-term inter-camera attitude biases by at least tens-of-arcsecs, and that several-to-tens-of-arcsecs per-rev star camera errors depend largely on field-of-view.

  5. TIM-1 rs41297579 G>A (-1454) and TIM-4 rs7700944 gene polymorphisms as possible risk factor for rheumatoid arthritis: relation to activity and severity.

    PubMed

    Mosaad, Y M; El-Bassiony, S R; El-Ghaweet, A E; Elhindawy, M M; El-Deek, B S; Sultan, W A

    2015-08-01

    This study was aimed to evaluate the impact of both TIM-1 rs41297579 G>A (-1454) and TIM-4 rs7700944 polymorphisms on susceptibility to rheumatoid arthritis (RA) in a cohort of Egyptian population and to evaluate for the first time their relation to activity, severity, disease-related disability and erosion. TIM-1 rs41297579 G>A (-1454) and TIM-4 rs7700944 gene polymorphisms were typed by RFLP for 128 patients with RA and 125 healthy controls. The A allele, A-containing genotypes (GA and AA) of the TIM-4 and GA haplotype were present with significant higher frequency in patients with RA than healthy controls (Pc  < 0.001). These findings suggest that the A allele, A-containing genotypes (GA and AA) and GA haplotype may be a susceptibility risk factor for RA [OR = 5.83 (3.6-9.4), OR = 9.41 (5.0-17.6) and OR = 4.21 (1.07-19.2), respectively]. No associations were found between TIM genotypes and disease activity, severity or presence of erosion. However, the RA patients with GA genotype of TIM-4 have higher grade of rheumatoid factor (RF) positivity (P = 0.018), and have worse disease-related disability (P = 0.007) and worse pain (0.025). TIM-4 rs7700944 and not TIM-1 rs41297579 G>A (-1454) is associated with RA in the present cohort of Egyptian and may be a risk factor for development of RA in Egyptian. Both SNPs have no effect on disease activity, severity or erosion. However, TIM-4 GA genotype is associated with higher grade of RF positivity and worse disease-related disability and pain.

  6. General Relativity&Compact Stars

    SciTech Connect

    Glendenning, Norman K.

    2005-08-16

    Compact stars--broadly grouped as neutron stars and white dwarfs--are the ashes of luminous stars. One or the other is the fate that awaits the cores of most stars after a lifetime of tens to thousands of millions of years. Whichever of these objects is formed at the end of the life of a particular luminous star, the compact object will live in many respects unchanged from the state in which it was formed. Neutron stars themselves can take several forms--hyperon, hybrid, or strange quark star. Likewise white dwarfs take different forms though only in the dominant nuclear species. A black hole is probably the fate of the most massive stars, an inaccessible region of spacetime into which the entire star, ashes and all, falls at the end of the luminous phase. Neutron stars are the smallest, densest stars known. Like all stars, neutron stars rotate--some as many as a few hundred times a second. A star rotating at such a rate will experience an enormous centrifugal force that must be balanced by gravity or else it will be ripped apart. The balance of the two forces informs us of the lower limit on the stellar density. Neutron stars are 10{sup 14} times denser than Earth. Some neutron stars are in binary orbit with a companion. Application of orbital mechanics allows an assessment of masses in some cases. The mass of a neutron star is typically 1.5 solar masses. They can therefore infer their radii: about ten kilometers. Into such a small object, the entire mass of our sun and more, is compressed.

  7. Pulsating Star Mystery Solved

    NASA Astrophysics Data System (ADS)

    2010-11-01

    By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. The new results, from a team led by Grzegorz Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), appear in the 25 November 2010 edition of the journal Nature. Grzegorz Pietrzyński introduces this remarkable result: "By using the HARPS instrument on the 3.6-metre telescope at ESO's La Silla Observatory in Chile, along with other telescopes, we have measured the mass of a Cepheid with an accuracy far greater than any earlier estimates. This new result allows us to immediately see which of the two competing theories predicting the masses of Cepheids is correct." Classical Cepheid Variables, usually called just Cepheids, are unstable stars that are larger and much brighter than the Sun [1]. They expand and contract in a regular way, taking anything from a few days to months to complete the cycle. The time taken to brighten and grow fainter again is longer for stars that are more luminous and shorter for the dimmer ones. This remarkably precise relationship makes the study of Cepheids one of the most effective ways to measure the distances to nearby galaxies and from there to map out the scale of the whole Universe [2]. Unfortunately, despite their importance, Cepheids are not fully understood. Predictions of their masses derived from the theory of pulsating stars are 20-30% less than predictions from the theory of the

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

    NASA Astrophysics Data System (ADS)

    Feiden, Gregory A.; Chaboyer, Brian

    2013-12-01

    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.

  9. Magnetic inhibition of convection and the fundamental properties of low-mass stars. I. Stars with a radiative core

    SciTech Connect

    Feiden, Gregory A.; Chaboyer, Brian E-mail: brian.chaboyer@dartmouth.edu

    2013-12-20

    Magnetic fields are hypothesized to inflate the radii of low-mass stars—defined as less massive than 0.8 M {sub ☉}—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.

  10. 75 FR 44051 - Resolicitation of Applications for the Railroad Safety Technology Program Grant Program (RS-TEC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Grant Program (RS-TEC-10-001) AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Notice of Funds Availability, Resolicitation of Applications (RS-TEC-10-001... Railroad Safety Technology Grant Program ] (Funding Opportunity RS-TEC-10-001), the Federal...

  11. Really Hot Stars

    NASA Astrophysics Data System (ADS)

    2003-04-01

    Spectacular VLT Photos Unveil Mysterious Nebulae Summary Quite a few of the most beautiful objects in the Universe are still shrouded in mystery. Even though most of the nebulae of gas and dust in our vicinity are now rather well understood, there are some which continue to puzzle astronomers. This is the case of a small number of unusual nebulae that appear to be the subject of strong heating - in astronomical terminology, they present an amazingly "high degree of excitation". This is because they contain significant amounts of ions, i.e., atoms that have lost one or more of their electrons. Depending on the atoms involved and the number of electrons lost, this process bears witness to the strength of the radiation or to the impact of energetic particles. But what are the sources of that excitation? Could it be energetic stars or perhaps some kind of exotic objects inside these nebulae? How do these peculiar objects fit into the current picture of universal evolution? New observations of a number of such unusual nebulae have recently been obtained with the Very Large Telescope (VLT) at the ESO Paranal Observatory (Chile). In a dedicated search for the origin of their individual characteristics, a team of astronomers - mostly from the Institute of Astrophysics & Geophysics in Liège (Belgium) [1] - have secured the first detailed, highly revealing images of four highly ionized nebulae in the Magellanic Clouds, two small satellite galaxies of our home galaxy, the Milky Way, only a few hundred thousand light-years away. In three nebulae, they succeeded in identifying the sources of energetic radiation and to eludicate their exceptional properties: some of the hottest, most massive stars ever seen, some of which are double. With masses of more than 20 times that of the Sun and surface temperatures above 90 000 degrees, these stars are truly extreme. PR Photo 09a/03: Nebula around the hot star AB7 in the SMC. PR Photo 09b/03: Nebula near the hot Wolf-Rayet star BAT99

  12. Atmospheres around Neutron Stars

    NASA Astrophysics Data System (ADS)

    Fryer, Chris L.; Benz, Willy

    1994-12-01

    Interest in the behavior of atmospheres around neutron stars has grown astronomically in the past few years. Some of this interest arrived in the wake of the explosion of Supernova 1987A and its elusive remnant; spawning renewed interest in a method to insure material ``fall-back'' onto the adolescent neutron star in an effort to transform it into a silent black hole. However, the bulk of the activity with atmospheres around neutron stars is concentrated in stellar models with neutron star, rather than white dwarf, cores; otherwise known as Thorne-Zytkow objects. First a mere seed in the imagination of theorists, Thorne-Zytkow objects have grown into an observational reality with an ever-increasing list of formation scenarios and observational prospects. Unfortunately, the analytic work of Chevalier on supernova fall-back implies that, except for a few cases, the stellar simulations of Thorne-Zytkow objects are missing an important aspect of physics: neutrinos. Neutrino cooling removes the pressure support of these atmospheres, allowing accretion beyond the canonical Eddington rate for these objects. We present here the results of detailed hydrodynamical simulations in one and two dimensions with the additional physical effects of neutrinos, advanced equations of state, and relativity over a range of parameters for our atmosphere including entropy and chemical composition as well as a range in the neutron star size. In agreement with Chevalier, we find, under the current list of formation scenarios, that the creature envisioned by Thorne and Zytkow will not survive the enormous appetite of a neutron star. However, neutrino heating (a physical effect not considered in Chevalier's analysis) can play an important role in creating instabilities in some formation schemes, leading to an expulsion of matter rather than rapid accretion. By placing scrutiny upon the formation methods, we can determine the observational prospects for each.

  13. Computational astrophysics: Pulsating stars

    NASA Astrophysics Data System (ADS)

    Davis, C. G.

    The field of computational astrophysics in pulsating star studies has grown considerably since the advent of the computer. Initially calculations were done on the IBM 704 with 32K of memory and now we use the CRAY YMP computers with considerably more memory. Our early studies were for models of pulsating stars using a 1D Lagrangian hydrodynamic code (SPEC) with radiation diffusion. The radiative transfer was treated in the equilibrium diffusion approximation and the hydrodynamics was done utilizing the approximation of artificial viscosity. The early calculations took many hours of 704 CPU time. Early in 1965 we decided to improve on the usual treatment of the radiative transfer used in our codes by utilizing the method of moments, the so-called variable Eddington approximation. In this approximation the material energy field is uncoupled from the radiation energy field and the angular dependence is introduced through the Eddington factor. A multigroup frequency dependent method may also be applied. The Eddington factor is determined by snapshots of the stars structure utilizing a y-line approximation. The full radiative transfer approximation appears necessary in order to understand the light curves for W Virginia stars and may be important for the light curves of RR Lyrae stars. A detailed radiative transfer method does not appear to be necessary for the understanding of Cepheid light curves. A recent improvement to our models for pulsating stars is in the use of an adaptive mesh scheme to resolve the sharp features in the nonlinear hydrodynamic structure. From these improved structures, better analysis of the radius, velocity, and light curves could be obtained.

  14. Weighing the Smallest Stars

    NASA Astrophysics Data System (ADS)

    2005-01-01

    VLT Finds Young, Very Low Mass Objects Are Twice As Heavy As Predicted Summary Thanks to the powerful new high-contrast camera installed at the Very Large Telescope, photos have been obtained of a low-mass companion very close to a star. This has allowed astronomers to measure directly the mass of a young, very low mass object for the first time. The object, more than 100 times fainter than its host star, is still 93 times as massive as Jupiter. And it appears to be almost twice as heavy as theory predicts it to be. This discovery therefore suggests that, due to errors in the models, astronomers may have overestimated the number of young "brown dwarfs" and "free floating" extrasolar planets. PR Photo 03/05: Near-infrared image of AB Doradus A and its companion (NACO SDI/VLT) A winning combination A star can be characterised by many parameters. But one is of uttermost importance: its mass. It is the mass of a star that will decide its fate. It is thus no surprise that astronomers are keen to obtain a precise measure of this parameter. This is however not an easy task, especially for the least massive ones, those at the border between stars and brown dwarf objects. Brown dwarfs, or "failed stars", are objects which are up to 75 times more massive than Jupiter, too small for major nuclear fusion processes to have ignited in its interior. To determine the mass of a star, astronomers generally look at the motion of stars in a binary system. And then apply the same method that allows determining the mass of the Earth, knowing the distance of the Moon and the time it takes for its satellite to complete one full orbit (the so-called "Kepler's Third Law"). In the same way, they have also measured the mass of the Sun by knowing the Earth-Sun distance and the time - one year - it takes our planet to make a tour around the Sun. The problem with low-mass objects is that they are very faint and will often be hidden in the glare of the brighter star they orbit, also when viewed

  15. American Urban Star Fest

    NASA Astrophysics Data System (ADS)

    Pazmino, John

    2003-12-01

    Over the last couple of decades New York City implemented, and continues to carry out, several schemes of eradicating luminous graffiti. One result has been the gradual recovery of the natural night sky. By 1994 the normal clear sky transparency over Manhattan deepened to fourth magnitude and has been slowly creeping deeper, until in 2002 it is at magnitude 4 to 4.5. In the spring of 1995, during some lazing on a Manhattan rooftop under a sky full of stars, several New York astronomers hatched the idea of letting the whole people celebrate the renewed starry sky. In due course they, through the Amateur Astronomers Association, engaged the New York City Parks Department and the Urban Park Rangers in an evening of quiet picnicking to enjoy the stars in their natural sky. Thus the Urban Star Fest was born. The event thrilled about 3,000 visitors in Central Park's Sheep Meadow on Saturday 30 September 1995. This year's Fest, the eighth in the series demonstrated the City's upper skyline of stars on Saturday 5 October 2002 to about 2,200 enthused visitors. Although the Fest is always noted as cancelable for inclement weather, so far, it has convened every year, with attendance ranging from 4,000 down to a mere 1,000, this latter being under the smoke plume of the World Trade Center in 2001. Despite this swing in attendance, the American Urban Star Fest is America's largest regularly scheduled public astronomy event. Of course, special occasions, like comets or eclipses, can and do attract far larger interest both in the city and elsewhere. The presentation shows the setup and program of the American Urban Star Fest, to illustrate how the general public can actively become aware of the night sky and see for themselves the result of their very own efforts at removing light pollution--and note where improvement is yet to come.

  16. Association Study between Coronary Artery Disease and rs1333049 and rs10757274 Polymorphisms at 9p21 Locus in South-West Iran

    PubMed Central

    Foroughmand, Ali Mohammad; Nikkhah, Emad; Galehdari, Hamid; Jadbabaee, Mohammad Hossin

    2015-01-01

    Objective Coronary artery disease (CAD) is a multi-factorial and heterogenic disease with atherosclerosis plaques formation in internal wall of coronary artery. Plaque formation results to limitation of the blood reaching to myocardium leading to appearance of some problems, such as ischemia, sudden thrombosis veins and myocardial infarction (MI). Several environmental and genetic factors are involved in prevalence and incident of CAD as follows: hypertension, high low density lipoprotein-cholesterol (LDL-C), age, diabetes mellitus, family history of early-onset heart disease and smoking. According to genome wide association studies (GWAS), five polymorphisms in the 9p21 locus seem to be associated with the CAD. We aimed to evaluate the remarkable association of two polymorphisms at 9p21 locus, rs1333049 and rs10757274, with CAD. Materials and Methods This experimental study was conducted in Golestan, Aria Hospitals and Genetics Lab of Shahid Chamran University in the city of Ahvaz, Iran, in 2010- 2011. The collected blood samples belonging to 170 CAD patients (case group) and 100 healthy individuals (control group) were analyzed by tetra-primer amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR) technique. The results were analyzed using software package used for statistical analysis (SPSS; SPSS Inc., USA) version 16. A value of p<0.05 and an odd ratio (OR) with 95% confidence intervals (CI) were considered significant. Results The frequencies of CC, CG and GG genotypes for rs1333049 polymorphism in patients were 18.2, 65.3 and 16.5%, while in controls, the related values were 25, 67 and 8%, respectively. GG genotypes of rs1333049 polymorphism in CAD patients were more than control cases (OR: 0.354, 95%CI: 0.138-0.912, p=0.032). The frequencies of AA, AG and GG genotypes for rs10757274 in CAD patients were 8.2, 58.3 and 33.5%, while in controls, the related values were 35, 63 and 2%, respectively. GG Genotype in rs10757274 polymorphism

  17. 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

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

    2013-01-01

    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. PMID:23471591

  18. Star cluster dynamics.

    PubMed

    Vesperini, Enrico

    2010-02-28

    Dynamical evolution plays a key role in shaping the current properties of star clusters and star cluster systems. A detailed understanding of the effects of evolutionary processes is essential to be able to disentangle the properties that result from dynamical evolution from those imprinted at the time of cluster formation. In this review, I focus my attention on globular clusters, and review the main physical ingredients driving their early and long-term evolution, describe the possible evolutionary routes and show how cluster structure and stellar content are affected by dynamical evolution.

  19. The DQ Herculis stars

    NASA Technical Reports Server (NTRS)

    Patterson, Joseph

    1994-01-01

    We review the properties of the DQ Herculis stars: cataclysmic variables containing an accreting, magnetic, rapidly rotating white dwarf. These stars are characterized by strong X-ray emission, high-excitation spectra, and very stable optical and X-ray pulsations in their light curves. There is considerable resemblance to their more famous cousins, the AM Herculis stars, but the latter class is additionally characterized by spin-orbit synchronism and the presence of strong circular polarization. We list eighteen stars passing muster as certain or very likely DQ Her stars. The rotational periods range from 33 s to 2.0 hr. Additional periods can result when the rotating searchlight illuminates other structures in the binary. A single hypothesis explains most of the observed properties: magnetically channeled accretion within a truncated disk. Some accretion flow still seems to proceed directly to the magnetosphere, however. The white dwarfs' magnetic moments are in the range 10(sup 32) - 10(sup 34) G cc, slightly weaker than in AM Her stars but with some probable overlap. The more important reason why DQ Hers have broken synchronism is probably their greater accretion rate and orbital separation. The observed L(sub x)/L(sub V) values are surprisingly low for a radially accreting white dwarf, suggesting that most of the accretion energy is not radiated in a strong shock above the magnetic pole. The fluxes can be more satisfactorily explained if most of the radial infall energy manages to bypass the shock and deposit itse lf directly in the white dwarf photosphere, where it should emerge as extreme ultraviolet (EUV) radiation. This also provides an adequate source of ionizing photons to power the high-excitation optical and UV emission lines. This is probably the DQ Her analog to the famous 'soft X-ray excess' in AM Her stars. However, unlike the AM Her case, this radiation has not been directly observed, so the analogy must not (yet) be embraced too firmly. There is

  20. Neutrinos from neutron stars

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.

    1979-01-01

    A calculation of the flux of ultra-high energy neutrinos from galactic neutron stars is presented. The calculation is used to determine the number of point sources detectable at the sensitivity threshold of a proposed deep underwater muon and neutrino detector array. The detector array would have a point source detection threshold of about 100 eV/sq cm-sec. Analysis of neutrino luminosities and the number of detectable sources suggests that the deep underwater detector may make a few discoveries. In particular, a suspected neutron star in the Cyg X-3 source seems a promising target for the deep underwater array.

  1. GeoSTAR

    NASA Astrophysics Data System (ADS)

    Lambrigtsen, B.; Gaier, T.; Tanner, A.; Kangaslahti, P.; Brown, S.

    2006-12-01

    The Geostationary Synthetic Thinned Aperture Radiometer, GeoSTAR, is a new concept for a microwave atmospheric sounder intended for geostationary satellites such as the GOES weather satellites operated by NOAA. A small but fully functional prototype has recently been developed at the Jet Propulsion Laboratory to demonstrate the feasibility of using aperture synthesis in lieu of the large solid parabolic dish antenna that is required with the conventional approach. Spatial resolution requirements dictate such a large aperture in GEO that the conventional approach has not been feasible, and it is only now with the GeoSTAR approach that a GEO microwave sounder can be contemplated. Others have proposed GEO microwave radiometers that would operate at sub-millimeter wavelengths to circumvent the large-aperture problem, but GeoSTAR is the only viable approach that can provide full sounding capabilities equal to or exceeding those of the AMSU systems now operating on LEO weather satellites and which have had tremendous impact on numerical weather forecasting. GeoSTAR will satisfy a number of important measurement objectives, many of them identified by NOAA as unmet needs in their GOES-R pre-planned product improvements (P3I) lists and others by NASA in their research roadmaps and as discussed in a white paper submitted to the NRC Decadal Survey. The performance of the prototype has been outstanding, and this proof of concept represents a major breakthrough in remote sensing capabilities. The GeoSTAR concept is now at a stage of development where an infusion into space systems can be initiated either on a NASA sponsored research mission or on a NOAA sponsored operational mission. GeoSTAR is an ideal candidate for a joint "research to operations" mission, and that may be the most likely scenario. Additional GeoSTAR related technology development and other risk reduction activities are under way, and a GeoSTAR mission is feasible in the GOES-R/S time frame, 2014-2016. This

  2. Synthetic guide star generation

    DOEpatents

    Payne, Stephen A.; Page, Ralph H.; Ebbers, Christopher A.; Beach, Raymond J.

    2004-03-09

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  3. Synthetic guide star generation

    DOEpatents

    Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

    2008-06-10

    A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

  4. The Drifting Star

    NASA Astrophysics Data System (ADS)

    2008-04-01

    By studying in great detail the 'ringing' of a planet-harbouring star, a team of astronomers using ESO's 3.6-m telescope have shown that it must have drifted away from the metal-rich Hyades cluster. This discovery has implications for theories of star and planet formation, and for the dynamics of our Milky Way. ESO PR Photo 09a/08 ESO PR Photo 09a/08 Iota Horologii The yellow-orange star Iota Horologii, located 56 light-years away towards the southern Horologium ("The Clock") constellation, belongs to the so-called "Hyades stream", a large number of stars that move in the same direction. Previously, astronomers using an ESO telescope had shown that the star harbours a planet, more than 2 times as large as Jupiter and orbiting in 320 days (ESO 12/99). But until now, all studies were unable to pinpoint the exact characteristics of the star, and hence to understand its origin. A team of astronomers, led by Sylvie Vauclair from the University of Toulouse, France, therefore decided to use the technique of 'asteroseismology' to unlock the star's secrets. "In the same way as geologists monitor how seismic waves generated by earthquakes propagate through the Earth and learn about the inner structure of our planet, it is possible to study sound waves running through a star, which forms a sort of large, spherical bell," says Vauclair. The 'ringing' from this giant musical instrument provides astronomers with plenty of information about the physical conditions in the star's interior. And to 'listen to the music', the astronomers used one of the best instruments available. The observations were conducted in November 2006 during 8 consecutive nights with the state-of-the-art HARPS spectrograph mounted on the ESO 3.6-m telescope at La Silla. Up to 25 'notes' could be identified in the unique dataset, most of them corresponding to waves having a period of about 6.5 minutes. These observations allowed the astronomers to obtain a very precise portrait of Iota Horologii: its

  5. A Real Shooting Star

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of A Real Shooting Star

    This artist's animation illustrates a star flying through our galaxy at supersonic speeds, leaving a 13-light-year-long trail of glowing material in its wake. The star, named Mira (pronounced my-rah) after the latin word for 'wonderful,' sheds material that will be recycled into new stars, planets and possibly even life. NASA's Galaxy Evolution Explorer discovered the long trail of material behind Mira during its survey of the entire sky in ultraviolet light.

    The animation begins by showing a close-up of Mira -- a red-giant star near the end of its life. Red giants are red in color and extremely bloated; for example, if a red giant were to replace our sun, it would engulf everything out to the orbit of Mars. They constantly blow off gas and dust in the form of stellar winds, supplying the galaxy with molecules, such as oxygen and carbon, that will make their way into new solar systems. Our sun will mature into a red giant in about 5 billion years.

    As the animation pulls out, we can see the enormous trail of material deposited behind Mira as it hurls along between the stars. Like a boat traveling through water, a bow shock, or build up of gas, forms ahead of the star in the direction of its motion. Gas in the bow shock is heated and then mixes with the cool hydrogen gas in the wind that is blowing off Mira. This heated hydrogen gas then flows around behind the star, forming a turbulent wake.

    Why does the trailing hydrogen gas glow in ultraviolet light? When it is heated, it transitions into a higher-energy state, which then loses energy by emitting ultraviolet light - a process known as fluorescence.

    Finally, the artist's rendering gives way to the actual ultraviolet image taken by the Galaxy Evolution Explorer

    Mira is located 350 light-years from Earth in the constellation Cetus, otherwise known as the whale. Coincidentally, Mira

  6. A Star on Earth

    SciTech Connect

    Prager, Stewart; Zwicker, Andrew; Hammet, Greg; Tresemer, Kelsey; Diallo, Ahmed

    2014-03-05

    At the Energy Department's Princeton Plasma Physics Lab, scientists are trying to accomplish what was once considered the realm of science fiction: create a star on Earth. The National Spherical Torus Experiment (NSTX) is a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which, under the right conditions, nuclear fusion will occur. Fusion is the energy source of the sun and all of the stars. Not just limited to theoretical work, the NSTX is enabling cutting-edge research to develop fusion as a future energy source.

  7. Isolating Triggered Star Formation

    SciTech Connect

    Barton, Elizabeth J.; Arnold, Jacob A.; Zentner, Andrew R.; Bullock, James S.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

    2007-09-12

    Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of

  8. A Star on Earth

    ScienceCinema

    Prager, Stewart; Zwicker, Andrew; Hammet, Greg; Tresemer, Kelsey; Diallo, Ahmed

    2016-07-12

    At the Energy Department's Princeton Plasma Physics Lab, scientists are trying to accomplish what was once considered the realm of science fiction: create a star on Earth. The National Spherical Torus Experiment (NSTX) is a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which, under the right conditions, nuclear fusion will occur. Fusion is the energy source of the sun and all of the stars. Not just limited to theoretical work, the NSTX is enabling cutting-edge research to develop fusion as a future energy source.

  9. Mesopotamian Star Lists

    NASA Astrophysics Data System (ADS)

    Horowitz, Wayne

    Sumerian and Akkadian names of stars and constellations occur in cuneiform texts for over 2,000 years, from the third millennium BC down to the death of cuneiform in the early first millennium AD, but no fully comprehensive list was ever compiled in antiquity. Lists of stars and constellations are available in both the lexical tradition and astronomical-astrological tradition of the cuneiform scribes. The longest list in the former is that in the series Urra = hubullu, in the latter, those in Mul-Apin.

  10. The neutron star zoo

    NASA Astrophysics Data System (ADS)

    Harding, Alice K.

    2013-12-01

    Neutron stars are a very diverse population, both in their observational and their physical properties. They prefer to radiate most of their energy at X-ray and gamma-ray wavelengths. But whether their emission is powered by rotation, accretion, heat, magnetic fields or nuclear reactions, they are all different species of the same animal whose magnetic field evolution and interior composition remain a mystery. This article will broadly review the properties of inhabitants of the neutron star zoo, with emphasis on their high-energy emission.

  11. Hidden Milky Way star clusters hosting Wolf-Rayet stars

    NASA Astrophysics Data System (ADS)

    Kurtev, R.; Borissova, J.; Ivanov, V. D.; Georgiev, L.

    2009-05-01

    A noticeable fraction of the hidden young star clusters contain WR and O stars providing us with unique laboratories to study the evolution of these rare objects and their maternity places. We are reporting the reddening, the distance and age of two new members of the family of massive young Galactic clusters, hosting WR stars - Glimpse 23 and Glimpse 30.

  12. Photographic photometry of variable stars

    NASA Technical Reports Server (NTRS)

    Kholopov, P. N.

    1973-01-01

    Photographic methods of determining stellar magnitude and measuring brightness of variable stars on negatives include the photoelectric method and the contascope. Calibration curves are usually plotted by the UBV method. Magnitudes of comparison stars can be determined from photographs.

  13. The Death of a Star

    ERIC Educational Resources Information Center

    Thorne, Kip S.

    1971-01-01

    Theories associated with the gravitational collapse of a star into black holes" are described. Suggests that the collapse and compression might go through the stages from white dwarf star to neutron core to black hole." (TS)

  14. Star Formation in Irregular Galaxies.

    ERIC Educational Resources Information Center

    Hunter, Deidre; Wolff, Sidney

    1985-01-01

    Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

  15. Finding Planets around other stars

    NASA Video Gallery

    Just as the Earth revolves around the sun, our closest star, other planets might orbit the stars you see in the night sky. Think of all the planets in the universe that may be just the right distan...

  16. Keplerian Frequency of Uniformly Rotating Neutron Stars in Relativistic Mean Field Theory

    NASA Astrophysics Data System (ADS)

    Zhang, N. B.; Qi, B.; Wang, S. Y.; Ge, S. L.; Sun, B. Y.

    2013-11-01

    Adopting the equation of states (EOSs) from the relativistic mean field (RMF) theory, the relationships among the keplerian frequency fK, gravitational mass M and radius R for the rapidly rotating neutron stars with and without hyperons are presented and analyzed. For various RMF EOSs, the empirical formula fK(M) = 1.08 (M/M⊙)1/2(R_S/10 km)-3/2 kHz, proposed by P. Haensel et al. [Astron. Astrophys.502 (2009) 605], is found to be an approximation with the error at most 13% and such approximation is worse for the neutron stars with hyperons. It indicates that the errors should be considered when the empirical formula is used to discuss the properties of neutron stars.

  17. A Vanishing Star Revisited

    NASA Astrophysics Data System (ADS)

    1999-07-01

    VLT Observations of an Unusual Stellar System Reinhold Häfner of the Munich University Observatory (Germany) is a happy astronomer. In 1988, when he was working at a telescope at the ESO La Silla observatory, he came across a strange star that suddenly vanished off the computer screen. He had to wait for more than a decade to get the full explanation of this unusual event. On June 10-11, 1999, he observed the same star with the first VLT 8.2-m Unit Telescope (ANTU) and the FORS1 astronomical instrument at Paranal [1]. With the vast power of this new research facility, he was now able to determine the physical properties of a very strange stellar system in which two planet-size stars orbit each other. One is an exceedingly hot white dwarf star , weighing half as much as the Sun, but only twice as big as the Earth. The other is a much cooler and less massive red dwarf star , one-and-a-half times the size of planet Jupiter. Once every three hours, the hot star disappears behind the other, as seen from the Earth. For a few minutes, the brightness of the system drops by a factor of more than 250 and it "vanishes" from view in telescopes smaller than the VLT. A variable star named NN Serpentis ESO PR Photo 30a/99 ESO PR Photo 30a/99 [Preview - JPEG: 400 x 468 pix - 152k] [Normal - JPEG: 800 x 936 pix - 576k] [High-Res - JPEG: 2304 x 2695 pix - 4.4M] Caption to ESO PR Photo 30a/99 : The sky field around the 17-mag variable stellar system NN Serpentis , as seen in a 5 sec exposure through a V(isual) filter with VLT ANTU and FORS1. It was obtained just before the observation of an eclipse of this unsual object and served to centre the telescope on the corresponding sky position. The field shown here measures 4.5 x 4.5 armin 2 (1365 x 1365 pix 2 ; 0.20 arcsec/pix). The field is somewhat larger than that shown in Photo 30b/99 and has the same orientation to allow comparison: North is about 20° anticlockwise from the top and East is 90° clockwise from that direction. The

  18. Consideration and Checkboxes: Incorporating Ethics and Science into the 3Rs

    PubMed Central

    Landi, Margaret S; Shriver, Adam J; Mueller, Anne

    2015-01-01

    Members of the research community aim to both produce high-quality research and ensure that harm is minimized in animals. The primary means of ensuring these goals are both met is the 3Rs framework of replacement, reduction, and refinement. However, some approaches to the 3Rs may result in a ‘check box mentality’ in which IACUC members, researchers, administrators, and caretakers check off a list of tasks to evaluate a protocol. We provide reasons for thinking that the 3Rs approach could be enhanced with more explicit discussion of the ethical assumptions used to arrive at an approved research protocol during IACUC review. Here we suggest that the notion of moral considerability, and all of the related issues it gives rise to, should be incorporated into IACUC discussions of 3Rs deliberations during protocol review to ensure that animal wellbeing is enhanced within the constraints of scientific investigation. PMID:25836970

  19. No Association of the rs17822931 Polymorphism in ABCC11 with Breast Cancer Risk in Koreans.

    PubMed

    Na, Ann-Yae; Heo, Jin-Chul; Sung, Jin Young; Lee, Jong-Ha; Kim, Yoon-Nyun; Kim, Dae-Kwang

    2016-01-01

    ABCC11 is reported to be associated with breast cancer. However, whether ABCC11 polymorphisms relate to breast cancer risk remains unclear. This study aimed to evaluate any association of a single nucleotide polymorphism (SNP), rs17822931, in ABCC11 with breast cancer in Koreans. Genomic DNA samples of 170 women with breast cancer and 100 controls were assessed for SNP rs17822931 of ABCC11 by single-strand conformation polymorphism (SSCP) and DNA sequencing. A 27-bp deletion (Δ27) of ABCC11 was analyzed by PCR amplification. The genotype of SNP rs17822931 was confirmed to be AA in all samples from breast cancer patients and Δ27 was found in none of the samples. Our finding indicated that the SNP rs17822931 in ABCC11 is not associated with breast cancer. However, this study does provide information on fundamental genetic aspects of ABCC11 with regard to breast cancer risk in Koreans. PMID:27268641

  20. Consideration and checkboxes: incorporating ethics and science into the 3Rs.

    PubMed

    Landi, Margaret S; Shriver, Adam J; Mueller, Anne

    2015-03-01

    Members of the research community aim to both produce high-quality research and ensure that harm is minimized in animals. The primary means of ensuring these goals are both met is the 3Rs framework of replacement, reduction, and refinement. However, some approaches to the 3Rs may result in a 'check box mentality' in which IACUC members, researchers, administrators, and caretakers check off a list of tasks to evaluate a protocol. We provide reasons for thinking that the 3Rs approach could be enhanced with more explicit discussion of the ethical assumptions used to arrive at an approved research protocol during IACUC review. Here we suggest that the notion of moral considerability, and all of the related issues it gives rise to, should be incorporated into IACUC discussions of 3Rs deliberations during protocol review to ensure that animal wellbeing is enhanced within the constraints of scientific investigation. PMID:25836970