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Sample records for candidate xte j1720-318

  1. High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318

    DEFF Research Database (Denmark)

    Bel, M.C.; Rodriguez, J.; Sizun, P.

    2004-01-01

    We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft......, typical of a black-hole binary in the so-called High/Soft State. We then followed the evolution of the source outburst over several months using the INTEGRAL Galactic Centre survey observations. The source became active again at the end of March: it showed a clear transition towards a much harder state...... of the black hole X-ray novae class which populate our galactic bulge and we discuss its properties in the frame of the spectral models used for transient black hole binaries....

  2. The 2003 radio outburst of a new X-ray transient: XTE J1720-318

    CERN Document Server

    Brocksopp, C; Fender, R P; Rupen, M; Sault, R; Tingay, S J; Hannikainen, D C; O'Brien, K

    2001-01-01

    We present radio observations of the black hole X-ray transient XTE J1720-318, which was discovered in 2003 January as it entered an outburst. We analyse the radio data in the context of the X-ray outburst and the broad-band spectrum. An unresolved radio source was detected during the rising phase, reaching a peak of nearly 5 mJy approximately coincident with the peak of the X-ray lightcurve. Study of the spectral indices suggests that at least two ejection events took place, the radio-emitting material expanding and becoming optically thin as it faded. The broad-band spectra suggested that the accretion disc dominated the emission, as expected for a source in the high/soft state. The radio emission decayed to below the sensitivity of the telescopes for ~6 weeks but switched on again during the transition of the X-ray source to the low/hard state. At least one ``glitch'' was superimposed on the otherwise exponential decay of the X-ray lightcurve, which was reminiscent of the multiple jet ejections of XTE J185...

  3. X-Ray Bursts from the Transient Magnetar Candidate XTE J1810-197

    Science.gov (United States)

    Kouveliotou, Chryssa; Woods, Peter M.; Gavriil, Fotis P.; Kaspi, Victoria M.; Roberts, Mallory S. E.; Ibrahim, Alaa; Markwardt, Craig B.; Swank, Jean H.; Finger, Mark H.

    2005-01-01

    We have discovered four X-ray bursts, recorded with the Rossi X-ray Timing Explorer Proportional Counter Array between 2003 September and 2004 April, that we show to originate from the transient magnetar candidate XTE 51810-197. The burst morphologies consist of a short spike or multiple spikes lasting approx. 1 s each followed by extended tails of emission where the pulsed flux from XTE 51810-197 is significantly higher. The burst spikes are likely correlated with the pulse maxima, having a chance probability of a random phase distribution of 0.4%. The burst spectra are best fit to a blackbody with temperatures 4-8 keV, considerably harder than the persistent X-ray emission. During the X-ray tails following these bursts, the temperature rapidly cools as the flux declines, maintaining a constant emitting radius after the initial burst peak. The temporal and spectral characteristics of these bursts closely resemble the bursts seen from 1E 1048.1-5937 and a subset of the bursts detected from 1E 2259+586, thus establishing XTE J1810-197 as a magnetar candidate. The bursts detected from these three objects are sufficiently similar to one another, yet si,g&cantly differe2t from those seen from soft gamma repeaters, that they likely represent a new class of bursts from magnetar candidates exclusive (thus far) to the anomalous X-ray pulsar-like sources.

  4. NuSTAR and SWIFT Observations of the Black Hole Candidate XTE J1908+094 during its 2013 Outburst

    DEFF Research Database (Denmark)

    Tao, Lian; Tomsick, John A.; Walton, Dominic J.

    2015-01-01

    The black hole (BH) candidate XTE J1908+094 went into outburst for the first time since 2003 in 2013 October. We report on an observation with the Nuclear Spectroscopic Telescope Array (NuSTAR) and monitoring observations with Swift during the outburst. NuSTAR caught the source in the soft state...

  5. A late jet rebrightening revealed from multiwavelength monitoring of the black hole candidate XTE J1752-223

    NARCIS (Netherlands)

    Russell, D.M.; Curran, P.A.; Muñoz-Darias, T.; Lewis, F.; Motta, S.; Stiele, H.; Belloni, T.; Miller-Jones, J.C.A.; Jonker, P.G.; O'Brien, K.; Homan, J.; Casella, P.; Gandhi, P.; Soleri, P.; Markoff, S.; Maitra, D.; Gallo, E.; Cadolle Bel, M.

    2012-01-01

    We present optical monitoring of the black hole candidate XTE J1752−223 during its 2009-10 outburst and decay to quiescence. The optical light curve can be described by an exponential decay followed by a plateau, then a more rapid fade towards quiescence. The plateau appears to be due to an extra co

  6. A strong and broad Fe line in the XMM-Newton spectrum of the new X-ray transient and black hole candidate XTE J1652-453

    NARCIS (Netherlands)

    Hiemstra, Beike; Méndez, Mariano; Done, Chris; Díaz Trigo, María; Altamirano, Diego; Casella, Piergiorgio

    2011-01-01

    We observed the new X-ray transient and black hole candidate XTE J1652-453 simultaneously with XMM-Newton and the Rossi X-ray Timing Explorer (RXTE). The observation was done during the decay of the 2009 outburst, when XTE J1652-453 was in the hard-intermediate state. The spectrum shows a strong and

  7. Multiwavelength Observations of the Black Hole Candidate XTE J1550-564 during the 2000 Outburst

    Science.gov (United States)

    Jain, Raj K.; Bailyn, Charles D.; Orosz, Jerome A.; McClintock, Jeffrey E.; Remillard, Ronald A.

    2001-06-01

    We report optical, infrared, and X-ray light curves for the outburst, in 2000, of the black hole candidate XTE J1550-564. We find that the start of the outburst in the H and V bands precedes that seen in the Rossi X-Ray Timing Explorer All-Sky Monitor by 11.5+/-0.9 and 8.8+/-0.6 days, respectively; a similar delay has been observed in two other systems. About 50 days after the primary maxima in the VIH light curves, we find secondary maxima, most prominently in H. This secondary peak is absent in the X-ray light curve but coincides with a transition to the low/hard state. We suggest that this secondary peak may be due to nonthermal emission associated with the formation of a jet.

  8. Multiwavelength Observations of the Black Hole Candidate XTE J1550-564 during the 2000 Outburst

    CERN Document Server

    Jain, R K; Orosz, J A; McClintock, J E; Remillard, R A

    2001-01-01

    We report optical, infrared, and X-ray light curves for the outburst, in 2000, of the black hole candidate XTE J1550-564. We find that the start of the outburst in the H and V bands precedes that seen in the RXTE All Sky Monitor by 11.5 +/- 0.9 and 8.8 +/- 0.6 days, respectively; a similar delay has been observed in two other systems. About 50 days after the primary maxima in the VIH light curves, we find secondary maxima, most prominently in H. This secondary peak is absent in the X-ray light curve, but coincides with a transition to the low/hard state. We suggest that this secondary peak may be due to non-thermal emission associated with the formation of a jet.

  9. Discovery and X-ray Monitoring of a New Black Hole Candidate XTE J1752-223

    Science.gov (United States)

    Shaposhnikov, Nikolai; Swank, J. H.; Markwardt, C. B.; Krimm, H.

    2010-03-01

    On October 23, 2009 a new X-ray transient source XTE J1752-223 was discovered by RXTE during observations scanning the Galactic Bulge region. Source identification in the optical, infra-red, and radio immediately followed. The first pointed RXTE observation, three days after the discovery, revealed a very hard non-thermal energy spectrum and strong iron line emission. After the initial rise the source flux leveled off and showed very stable properties for more than a month of monitoring observations until the Sun was too close for RXTE to observe. We analyzed RXTE data collected during this monitoring campaign. The aperiodic fast variability properties are strongly reminiscent of the extreme hard states shown by the well known black hole binary Cygnus X-1, as well as several other black hole candidates. The overall similarity of the source properties to those of other Galactic black holes classify XTE J1752-223 as a new stellar black hole candidate. We compare spectral and variability properties of XTE J1752-223 to Cygnus X-1 and discuss possible implications for various mechanisms of non-thermal emission.

  10. MAXI GSC observations of a spectral state transition in the black hole candidate XTE J1752-223

    CERN Document Server

    Nakahira, Satoshi; Sugizaki, Mutsumi; Ueda, Yoshihiro; Negoro, Hitoshi; Ebisawa, Ken; Kawai, Nobuyuki; Matsuoka, Masaru; Tsunemi, Hiroshi; Daikyuji, Arata; Eguchi, Satoshi; Hiroi, Kazuo; Ishikawa, Masaki; Ishiwata, Ryoji; Isobe, Naoki; Kawasaki, Kazuyoshi; Kimura, Masashi; Kohama, Mitsuhiro; Mihara, Tatehiro; Miyoshi, Sho; Morii, Mikio; Nakagawa, Yujin E; Nakajima, Motoki; Ozawa, Hiroshi; Sootome, Tetsuya; Sugimori, Kousuke; Suzuki, Motoko; Tomida, Hiroshi; Ueno, Shiro; Yamamoto, Takayuki; Yoshida, Atsumasa

    2010-01-01

    We present the first results on the black hole candidate XTE J1752-223 from the Gas Slit Camera (GSC) on-board the Monitor of All-sky X-ray Image (MAXI) on the International Space Station. Including the onset of the outburst reported by the Proportional Counter Array on-board the Rossi X-ray Timing Explorer on 2009 October 23, the MAXI/GSC has been monitoring this source approximately 10 times per day with a high sensitivity in the 2-20 keV band. XTE J1752-223 was initially in the low/hard state during the first 3 months. An anti-correlated behavior between the 2-4 keV and 4-20 keV bands were observed around January 20, 2010, indicating that the source exhibited the spectral transition to the high/soft state. A transient radio jet may have been ejected when the source was in the intermediate state where the spectrum was roughly explained by a power-law with a photon index of 2.5-3.0. The unusually long period in the initial low/hard state implies a slow variation in the mass accretion rate, and the dramatic s...

  11. Application of the Nonballistic Model to the Black Hole Candidate XTE J1752-223 and the Quasar NRAO 150

    Science.gov (United States)

    Zheng, T. Y.; Gong, B. P.

    2017-02-01

    Optical and radio observations of the black hole candidate XTE J1752-223 have exhibited a slightly curved motion of the jet components, which is associated with its radio light curve. In addition, observations of the quasar NRAO 150 have revealed a core–jet structure wobbling with a high angular speed. In this paper, the phenomena displayed in these two different sources are interpreted as the precession of a bent jet. In such a scenario, hot spots reproduced at different separations from the core precess on the same precession cone, in which different components correspond to different propagation times to the observer. By fitting the kinematics of the components of XTE J1752-223 and its light curve with a curved pattern of precession period 314 days, we find that the propagation time can make an earlier event appear later, and the jet axis can oscillate during its precession. Simulating the quasar NRAO 150 with the same scenario reveals that the knots at larger separation from the core precess at a slower speed than those closer in. A possible mechanism relating to the cooling time of a component is proposed. These three new results are of importance in understanding the physics underlying the curved jet as well as the activity of the central engine of different black hole systems.

  12. A strong and broad iron line in the XMM-Newton spectrum of the new X-ray transient and black-hole candidate XTE J1652-453

    NARCIS (Netherlands)

    Hiemstra, Beike; Mendez, Mariano; Done, Chris; Trigo, Maria Diaz; Altamirano, Diego; Casella, Piergiorgio

    2010-01-01

    ABSTRACT We observed the new X-ray transient and black-hole candidate XTE J1652−453 si- multaneously with XMM-Newton and the Rossi X-ray Timing Explorer (RXTE). The observation was done during the decay of the 2009 outburst, when XTE J1652−453 was in the hard-intermediate state. The spectrum shows a

  13. Spectral and Temporal Behavior of the Black Hole Candidate XTE J1118+480 as Observed with BeppoSAX

    CERN Document Server

    Frontera, F; Zdziarski, A A; Belloni, T; Del Sordo, S; Masetti, N; Orlandini, M; Palazzi, E

    2003-01-01

    XTE J1118+480 is a well established black hole candidate with a mass estimate in the range from 7 to 10 solar masses. With BeppoSAX we observed the source 4 times, from April to December 2000. Results of the firs t observation were already reported (Frontera et al. 2001). Here we report spectral results of the later observations, performed in May, June and December 2000 and compare them with the results obtained from the 2000 April observation. We observe a decrease of the column density from a value consistent with the Galactic N_H obtained from radio measurement s to a value a factor 2 lower. The spectra are well fit with a thermal Comptonization plus a blackbody model. The blackbody luminosity decreases with time, while the electron temperature of the Comptonizing electron s does not show significant changes. A Compton reflection component is apparent and stable, although weak (mean value of Omega/2pi = 0.21[-0.04,+0.05]). The reflector shows a low metallicity (mean value of Z/Zsun = 0.13[-0.04,+0.06]). On...

  14. NuSTAR and Swift observations of the black hole candidate XTE J1908+094 during its 2013 outburst

    CERN Document Server

    Tao, Lian; Walton, Dominic J; Furst, Felix; Kennea, Jamie; Miller, Jon M; Boggs, Steven E; Christensen, Finn E; Craig, William W; Gandhi, Poshak; Grefenstette, Brian W; Hailey, Charles J; Harrison, Fiona A; Krimm, Hans A; Pottschmidt, Katja; Stern, Daniel; Tendulkar, Shriharsh P; Zhang, William W

    2015-01-01

    The black hole candidate XTE J1908+094 went into outburst for the first time since 2003 in October 2013. We report on an observation with the Nuclear Spectroscopic Telescope Array (NuSTAR) and monitoring observations with Swift during the outburst. NuSTAR caught the source in the soft state: the spectra show a broad relativistic iron line, and the light curves reveal a ~40 ks flare with the count rate peaking about 40% above the non-flare level and with significant spectral variation. A model combining a multi-temperature thermal component, a power-law, and a reflection component with an iron line provides a good description of the NuSTAR spectrum. Although relativistic broadening of the iron line is observed, it is not possible to constrain the black hole spin with these data. The variability of the power-law component, which can also be modeled as a Comptonization component, is responsible for the flux and spectral change during the flare, suggesting that changes in the corona (or possibly continued jet act...

  15. A late jet rebrightening revealed from multi-wavelength monitoring of the black hole candidate XTE J1752-223

    CERN Document Server

    Russell, D M; Muñoz-Darias, T; Lewis, F; Motta, S; Stiele, H; Belloni, T; Miller-Jones, J C A; Jonker, P G; O'Brien, K; Homan, J; Casella, P; Gandhi, P; Soleri, P; Markoff, S; Maitra, D; Gallo, E; Bel, M Cadolle

    2011-01-01

    We present optical monitoring of the black hole candidate XTE J1752-223 during its 2009 - 2010 outburst and decay to quiescence. The optical light curve can be described by an exponential decay followed by a plateau, then a more rapid fade towards quiescence. The plateau appears to be due to an extra component of optical emission that brightens and then fades over ~ 40 days. We show evidence for the origin of this optical 'flare' to be the synchrotron jet during the decaying hard state, and we identify and isolate both disc and jet components in the spectral energy distributions. The optical flare has the same morphology and amplitude as a contemporaneous X-ray rebrightening. This suggests a common origin, but no firm conclusions can be made favouring or disfavouring the jet producing the X-ray flare. The quiescent optical magnitudes are B >= 20.6, V >= 21.1, R >= 19.5, i' >= 19.2. From the optical outburst amplitude we estimate a likely orbital period of < 22 h. We also present near-infrared (NIR) photome...

  16. Correlated X-ray Spectral and Timing Behavior of the Black Hole Candidate XTE J1550-564

    CERN Document Server

    Homan, J; Van der Klis, M; Belloni, T; Van Paradijs, J; Klein-Wolt, M; Fender, R P; Méndez, M; Homan, Jeroen; Wijnands, Rudy; Klis, Michiel van der; Belloni, Tomaso; Paradijs, Jan van; Klein-Wolt, Marc; Fender, Robert P; Mendez, Mariano

    2000-01-01

    We present an analysis of data of the black hole X-ray transient XTE J1550-564, taken with RXTE between 1998 Nov 22 and 1999 May 20. The source went through several different states, which were divided into soft and hard states, based on the relative strength of the high energy power law tail. The states showed up as distinct branches in the color-color diagram, connecting to form a structure with a comb-like topology, the branch corresponding to the soft state forming the spine and the branches corresponding to the various hard states forming the teeth of the comb. The power spectral properties of each branch were correlated with their spectral properties. Three types of QPOs were found: 1-18 Hz and 100-285 Hz QPOs on the hard branches, and 15-18 Hz QPOs on and near the soft branch. The frequency of the high and low frequency QPOs on the hard branches were correlated with each other, and with spectral hardness. The behavior of the XTE J1550-564 strongly favors a two-dimensional description of black hole beha...

  17. Discovery and Monitoring of a New Black Hole Candidate XTE J1752-223 with RXTE: RMS Spectrum Evolution, BH Mass and the Source Distance

    Science.gov (United States)

    Shaposhinikov, Nikolai; Markwardt, Craig; Swank, Jean; Krimm, Hans

    2010-01-01

    We report on the discovery and monitoring observations of a new galactic black hole candidate XTE J1752-223 by Rossi X-ray Timing Explorer (RXTE). The new source appeared on the X-ray sky on October 21 2009 and was active for almost 8 months. Phenomenologically, the source exhibited the low-hard/highsoft spectral state bi-modality and the variability evolution during the state transition that matches standard behavior expected from a stellar mass black hole binary. We model the energy spectrum throughout the outburst using a generic Comptonization model assuming that part of the input soft radiation in the form of a black body spectrum gets reprocessed in the Comptonizing medium. We follow the evolution of fractional root-mean-square (RMS) variability in the RXTE/PCA energy band with the source spectral state and conclude that broad band variability is strongly correlated with the source hardness (or Comptonized fraction). We follow changes in the energy distribution of rms variability during the low-hard state and the state transition and find further evidence that variable emission is strongly concentrated in the power-law spectral component. We discuss the implication of our results to the Comptonization regimes during different spectral states. Correlations of spectral and variability properties provide measurements of the BH mass and distance to the source. The spectral-timing correlation scaling technique applied to the RXTE observations during the hardto- soft state transition indicates a mass of the BH in XTE J1752-223 between 8 and 11 solar masses and a distance to the source about 3.5 kiloparsec.

  18. The black hole candidate XTE J1752-223 towards and in quiescence: optical and simultaneous X-ray-radio observations

    NARCIS (Netherlands)

    Ratti, E.M.; Jonker, P.G.; Miller-Jones, J.C.A.; Torres, M.A.P.; Homan, J.; Markoff, S.; Tomsick, J.; Kaaret, P.; Wijnands, R.; Gallo, E.; Özel, F.; Steeghs, D.T.H.; Fender, R.P.

    2012-01-01

    We present optical, X-ray and radio observations of the black hole transient (BHT) XTE J1752−223 towards and in quiescence. Optical photometry shows that the quiescent magnitude of XTE J1752−223 is fainter than 24.4 mag in the i′ band. A comparison with measurements of the source during its 2009-201

  19. An accurate position for the black hole candidate XTE J1752-223: re-interpretation of the VLBI data

    CERN Document Server

    Miller-Jones, J C A; Ratti, E M; Torres, M A P; Brocksopp, C; Yang, J; Morrell, N I

    2011-01-01

    Using high-precision astrometric optical observations from the Walter Baade Magellan Telescope in conjunction with high-resolution very long baseline interferometric (VLBI) radio imaging with the Very Long Baseline Array (VLBA), we have located the core of the X-ray binary system XTE J1752-223. Compact radio emission from the core was detected following the state transition from the soft to the hard X-ray state. Its position to the south-east of all previously-detected jet components mandated a re-analysis of the existing VLBI data. Our analysis suggests that the outburst comprised at least two ejection events prior to 2010 February 26. No radio-emitting components were detected to the south-east of the core at any epoch, suggesting that the receding jets were Doppler-deboosted below our sensitivity limit. From the ratio of the brightness of the detected components to the measured upper limits for the receding ejecta, we constrain the jet speed to be greater than 0.66c and the inclination angle to the line of...

  20. An accurate position for the black hole candidate XTE J1752-223: re-interpretation of the VLBI data

    Science.gov (United States)

    Miller-Jones, J. C. A.; Jonker, P. G.; Ratti, E. M.; Torres, M. A. P.; Brocksopp, C.; Yang, J.; Morrell, N. I.

    2011-07-01

    Using high-precision astrometric optical observations from the Walter Baade Magellan Telescope in conjunction with high-resolution very long baseline interferometric (VLBI) radio imaging with the Very Long Baseline Array (VLBA), we have located the core of the X-ray binary system XTE J1752-223. Compact radio emission from the core was detected following the state transition from the soft to the hard X-ray state. Its position to the south-east of all previously detected jet components mandated a re-analysis of the existing VLBI data. Our analysis suggests that the outburst comprised at least two ejection events prior to 2010 February 26. No radio-emitting components were detected to the south-east of the core at any epoch, suggesting that the receding jets were Doppler-deboosted below our sensitivity limit. From the ratio of the brightness of the detected components to the measured upper limits for the receding ejecta, we constrain the jet speed β > 0.66 and the inclination angle to the line of sight θ < 49°. Assuming that the initial ejection event occurred at the transition from the hard intermediate state to the soft intermediate state, an initial period of ballistic motion followed by a Sedov phase (i.e. self-similar adiabatic expansion) appears to fit the motion of the ejecta better than a uniform deceleration model. The accurate core location can provide a long time baseline for a future proper motion determination should the system show a second outburst, providing insights into the formation mechanism of the compact object.

  1. Evidence of Spin and Energy Extraction in a Galactic Black Hole Candidate: The XMM-NEWTON/EPIC SPECTRUM of XTE 11650-500

    Science.gov (United States)

    Miller, J. M.; Fabian, A. C.; Wunands, R.; Reynolds, C. S.; Ehle, M.; Freyberg, M. J.; VanDerKlis, M.; Lewin, W. H. G.; Sanchez-Fernandez, C.; Castro-Tirado, A. J.

    2002-01-01

    We observed the Galactic black hole candidate XTE J1650-500 early in its fall of 2001 outburst with the XMM-Newton European Photon Imaging pn Camera (EPIC-pn). The observed spectrum is consistent with the source having been in the very high state. We h d a broad, skewed Fe Kar emission line that suggests the primary in this system may be a Kerr black hole and that indicates a steep disk emissivity profile that is hard to explain in terms of a standard accretion disk model. These results are quantitatively and qualitatively similar to those from an XMM-Newton observation of the Seyfert galaxy MCG -6-30-15. The steep emissivity in MCG -6-30-15 may be explained by the extraction and dissipation of rotational energy from a black hole with nearly maximal angular momentum or from material in the plunging region via magnetic connections to the inner accretion disk. If this process is at work in both sources, an exotic but fundamental general relativistic prediction may be confirmed across a factor of l0(exp 6) in black hole mass. We discuss these results in terms of the accretion flow geometry in stellar-mass black holes and the variety of enigmatic phenomena often observed in the very high state.

  2. A Spectral Study of the Black Hole Candidate XTE J1752-223 in the High/Soft State with MAXI, Suzaku and Swift

    CERN Document Server

    Nakahira, Satoshi; Uedu, Yoshihiro; Yamaoka, Kazutaka; Sugizaki, Mutsumi; Mihara, Tatehiro; Matsuoka, Masaru; Yoshida, Atsumasa; Makishima, Kazuo; Ebisawa, Ken; Kubota, Aya; Yamada, Shin'ya; Negoro, Hitoshi; Hiroi, Kazuo; Ishikawa, Masaki; Kawai, Nobuyuki; Kimura, Masashi; Kitayama, Hiroki; Kohama, Mitsuhiro; Matsumura, Takanori; Morii, Mikio; Nakajima, Motoki; Serino, Motoko; Shidatsu, Megumi; Sootome, Tetsuya; Sugimori, Kousuke; Suwa, Fumitoshi; Tomida, Hiroshi; Tsuboi, Yoko; Tsunemi, Hiroshi; Ueno, Shiro; Usui, Ryuichi; Yamamoto, Takayuki; Yamazaki, Kyohei; Tashiro, Makoto S; Terada, Yukikatsu; Seta, Hiromi

    2011-01-01

    We report on the X-ray spectral analysis of the black hole candidate XTE\\ J1752--223 in the 2009--2010 outburst, utilizing data obtained with the MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work complementarily. As already reported by Nakahira et al. (2010) MAXI monitored the source continuously throughout the entire outburst for about eight months. All the MAXI/GSC energy spectra in the high/soft state lasting for 2 months are well represented by a multi-color disk plus power-law model. The innermost disk temperature changed from $\\sim$0.7 keV to $\\sim$0.4 keV and the disk flux decreased by an order of magnitude. Nevertheless, the innermost radius is constant at $\\sim$41 $D_{3.5}(\\cos{\\it i})^{-1/2}$ km, where $D_{3.5}$ is the source distance in units of 3.5 kpc and $i$ the inclination. The multi-color disk parameters obtained with the MAXI/GSC are consistent with those with the Swift/XRT and Suzaku. The Suzaku data also suggests a possibility that the disk emission is slightly Comptonized, ...

  3. Evidence for Spin and Energy Extraction in a Galactic Black Hole Candidate The XMM-Newton\\/EPIC-pn Spectrum of XTE J1650-500

    CERN Document Server

    Miller, J M; Wijnands, R; Reynolds, C S; Ehle, M; Freyberg, M J; Van der Klis, M; Lewin, W H G; Sánchez-Fernández, C; Castro-Tirado, A J

    2002-01-01

    We observed the Galactic black hole candidate XTE J1650-500 early in its Fall, 2001 outburst with the XMM-Newton European Photon Imaging pn Camera (EPIC-pn). The observed spectrum is consistent with the source having been in the "very high" state. We find a broad, skewed Fe K-alpha emission line which suggests that the primary in this system may be a Kerr black hole, and which indicates a steep emissivity profile that is hard to explain in terms of a standard accretion disk model. These results are quantitatively and qualitatively similar to those from an XMM-Newton observation of the Seyfert galaxy MCG--6-30-15. The steep emissivity in MCG--6-30-15 may be explained by the extraction and dissipation of rotational energy from a black hole with nearly- maximal angular momentum or material in the plunging region via magnetic connections to the inner accretion disk. If this process is at work in both sources, an exotic but fundamental general relativistic prediction may be confirmed across a factor of 10^6 in bla...

  4. The black hole candidate XTE J1752-223 towards and in quiescence: optical and simultaneous X-ray-radio observations

    Science.gov (United States)

    Ratti, E. M.; Jonker, P. G.; Miller-Jones, J. C. A.; Torres, M. A. P.; Homan, J.; Markoff, S.; Tomsick, J. A.; Kaaret, P.; Wijnands, R.; Gallo, E.; Özel, F.; Steeghs, D. T. H.; Fender, R. P.

    2012-07-01

    We present optical, X-ray and radio observations of the black hole transient (BHT) XTE J1752-223 towards and in quiescence. Optical photometry shows that the quiescent magnitude of XTE J1752-223 is fainter than 24.4 mag in the i' band. A comparison with measurements of the source during its 2009-2010 outburst shows that the outburst amplitude is more than 8 mag in the i' band. Known X-ray properties of the source combined with the faintness of the quiescence optical counterpart and the large outburst optical amplitude point towards a short orbital-period system (Porb≲ 6.8 h) with an M type (or later) mass donor, at a distance of 3.5 ≲d≲ 8 kpc. Simultaneous X-ray and radio data were collected with Chandra and the Expanded Very Large Array (EVLA), allowing constraints to be placed on the quiescent X-ray and radio flux of XTE J1752-223. Furthermore, using data covering the final stage of the outburst decay, we investigated the low-luminosity end of the X-ray-radio correlation for this source and compared it with other BHTs. We found that XTE J1752-223 adds to the number of outliers with respect to the 'standard' X-ray-radio luminosity relation. Furthermore, XTE J1752-223 is the second source, after the BHT H1743-322, that shows a transition from the region of the outliers towards the 'standard' correlation at low luminosity. Finally, we report on a faint, variable X-ray source we discovered with Chandra at an angular distance of ˜2.9 arcsec to XTE J1752-223 and at a position angle consistent with that of the radio jets previously observed from the BHT. We discuss the possibility that we detected X-ray emission associated with a jet from XTE J1752-223.

  5. A strong and broad iron line in the XMM-Newton spectrum of the new X-ray transient and black-hole candidate XTE J1652-453

    CERN Document Server

    Hiemstra, Beike; Done, Chris; Trigo, Maria Diaz; Altamirano, Diego; Casella, Piergiorgio

    2010-01-01

    We observed the new X-ray transient and black-hole candidate XTE J1652-453 simultaneously with XMM-Newton and the Rossi X-ray Timing Explorer (RXTE). The observation was done during the decay of the 2009 outburst, when XTE J1652-453 was in the hard-intermediate state. The spectrum shows a strong and broad iron emission line with an equivalent width of ~ 450 eV. The profile is consistent with that of a line being produced by reflection off the accretion disk, broadened by relativistic effects close to the black hole. The best-fitting inner radius of the accretion disk is ~ 4 gravitational radii. Assuming that the accretion disk is truncated at the radius of the innermost stable circular orbit, the black hole in XTE J1652-453 has a spin parameter of ~ 0.5. The power spectrum of the RXTE observation has an additional variability component above 50 Hz, which is typical for the hard-intermediate state. No coherent quasi-periodic oscillations at low frequency are apparent in the power spectrum, which may imply that...

  6. The black hole candidate XTE J1752-223 towards and in quiescence: optical and simultaneous X-ray - radio observations

    CERN Document Server

    Ratti, E M; Miller-Jones, J C A; Torres, M A P; Homan, J; Markoff, S; Tomsick, J A; Kaaret, P; Wijnands, R; Gallo, E; Ozel, F; Steeghs, D T H; Fender, R P

    2012-01-01

    We present optical, X-ray and radio observations of the black hole transient (BHT) XTE J1752-223 towards and in quiescence. Optical photometry shows that the quiescent magnitude of XTE J1752-223 is fainter than 24.4 magnitudes in the i'-band. A comparison with measurements of the source during its 2009-2010 outburst shows that the outburst amplitude is more than 8 magnitudes in the i'-band. Known X-ray properties of the source combined with the faintness of the quiescence optical counterpart and the large outburst optical amplitude point towards a short orbital period system (Porb<~6.8 h) with an M type (or later) mass donor, at a distance of 3.5<~d<~8 kpc. Simultaneous X-ray and radio data were collected with Chandra and the EVLA, allowing constraints to be placed on the quiescent X-ray and radio flux of XTE J1752-223. Furthermore, using data covering the final stage of the outburst decay, we investigated the low luminosity end of the X-ray - radio correlation for this source and compared it with ot...

  7. Doppler Imaging of Black Hole SYSTEMS:XTE J1118+480.

    Science.gov (United States)

    Callanan, Paul; Perres-Torres, Manuel; Garcia, Michael

    We present time-resolved spectroscopy of the black-hole candidate XTE J1118+480 obtained during its approach to quiescence. Doppler imaging of the intense Hα line shows persistent emission with an origin in the gas stream/hotspot. In addition the Doppler maps show enhanced emission in the +Vx -Vy quadrant clearing incompatible with a stream/hotspot origin. We favour a non-uniform disk intensity distribution due to tidal effects as the origin of this emission. We compare our map with that of XTE J1118+480 in outburst as well as with those of other transient systems in quiescence

  8. Excitation of a nonradial mode in a millisecond X-ray pulsar XTE J1751-305

    CERN Document Server

    Lee, Umin

    2014-01-01

    We discuss candidates for non-radial modes excited in a mass accreting and rapidly rotating neutron star to explain the coherent frequency identified in the light curves of a millisecond X-ray pulsar XTE J1751-305. The spin frequency of the pulsar is $\

  9. High Frequency Quasi-Periodic Oscillations in the 2000 Outburst of the Galactic Microquasar XTE J1550-564

    CERN Document Server

    Miller, J M; Homan, J; Belloni, T; Pooley, D; Corbel, S; Kouveliotou, C; Van der Klis, M; Lewin, W H G

    2001-01-01

    We present an analysis of the high frequency timing properties of the April-May 2000 outburst of the black hole candidate and Galactic microquasar XTE J1550-564, measured with the Rossi X-ray Timing Explorer. The rapid X-ray variability we measure is consistent with the source being in either the ``very high'' or ``intermediate'' black hole state. Strong (5-8% rms) quasi-periodic oscillations (QPOs) are found between 249-278 Hz; this represents the first detection of the same high frequency QPO in subsequent outbursts of a transient black hole candidate. We also present evidence for lower-frequency QPOs at approximately 187 Hz, also reported previously and likely present simultaneously with the higher-frequency QPOs. We discuss these findings within the context of the 1998 outburst of XTE J1550-564, and comment on implications for models of QPOs, accretion flows, and black hole spin.

  10. Disentangling the NIR/optical emission of the black hole XTE J1650-500 during outburst

    CERN Document Server

    Curran, P A; Heras, J A Zurita

    2012-01-01

    While the sources of X-ray and radio emission in the different states of low-mass X-ray binaries are relatively well understood, the origin of the near-infrared (NIR) and optical emission is more often debated. It is likely that the NIR/optical flux originates from an amalgam of different emission regions, because it occurs at the intersecting wavelengths of multiple processes. We aim to identify the NIR/optical emission region(s) of one such low-mass X-ray binary and black hole candidate, XTE J1650-500, via photometric, timing, and spectral analyses. We present unique NIR/optical images and spectra, obtained with the ESO-New Technology Telescope, during the peak of the 2001 outburst of XTE J1650-500. The data suggest that the NIR/optical flux is due to a combination of emission mechanisms including a significant contribution from X-ray reprocessing and, at early times in the hard state, a relativistic jet that is NIR/radio dim compared to similar sources.The jet of XTE J1650-500 is relatively weak compared t...

  11. Multiwavelength observations revealing the outbursts of the two soft X-ray transients XTE J1859+226 and XTE J1118+480

    CERN Document Server

    Chaty, S; Hynes, R I; Shrader, C R; Cui, W; Mauche, C W; Norton, A J; Solheim, J E; Ostensen, R; Geballe, T R; Ioannou, Z; King, A R

    2001-01-01

    We report here on multiwavelength observations of the two new soft X-ray transients (SXTs) XTE J1859+226 and XTE J1118+480, which we observed with HST/RXTE/UKIRT. For XTE J1118+480 we also used EUVE since it is located at a very high galactic latitude and suffers from very low extinction. The two sources exhibited very different behaviour. XTE J1859+226 seems quite normal and therefore a good object for testing the accretion mechanisms in place during the outbursts, XTE J1118+480 is much more unusual because it exhibits i) a low X-ray to optical ratio and ii) a strong non-thermal contribution in the radio to optical domain, which is likely to be due to synchrotron emission. We concentrate here on the near-infrared (NIR) and optical observations of these two systems.

  12. Optical observations of XTE J1709-267

    Science.gov (United States)

    Wiersema, K.; Higgins, A. B.

    2016-06-01

    The X-ray binary XTE J1709-267 was recently found to be in outburst again by MAXI (Atel #9108). We observed this source using EFOSC2 on the ESO NTT. At 02:33 UT on 23 June 2016, the source was detected at V=17.9 mag. This is several magnitudes brighter than the brightness in quiescence (Jonker et al. 2004, MNRAS 354, 666).

  13. Radio polarimetry as a probe of unresolved jets: the 2013 outburst of XTE J1908+094

    CERN Document Server

    Curran, P A; Rushton, A P; Pawar, D D; Anderson, G E; Altamirano, D; Krimm, H A; Broderick, J W; Belloni, T M; Fender, R P; Kording, E G; Maitra, D; Markoff, S; Migliari, S; Rumsey, C; Rupen, M P; Russell, D M; Russell, T D; Sarazin, C L; Sivakoff, G R; Soria, R; Tetarenko, A J; Titterington, D; Tudose, V

    2015-01-01

    XTE J1908+094 is an X-ray transient black hole candidate in the Galactic plane that was observed in outburst in 2002 and 2013. Here we present multi-frequency radio and X-ray data, including radio polarimetry, spanning the entire period of the 2013 outburst. We find that the X-ray behaviour of XTE J1908+094 traces the standard black hole hardness-intensity path, evolving from a hard state, through a soft state, before returning to a hard state and quiescence. Its radio behaviour is typical of a compact jet that becomes quenched before discrete ejecta are launched during the late stages of X-ray softening. The radio and X-ray fluxes, as well as the light curve morphologies, are consistent with those observed during the 2002 outburst of this source. The polarisation angle during the rise of the outburst infers a jet orientation in agreement with resolved observations but also displays a gradual drift, which we associate with observed changes in the structure of the discrete ejecta. We also observe an unexpected...

  14. Multiwavelength observations revealing the outbursts of the soft X-ray transients XTE J1859+226 and XTE J1118+480

    CERN Document Server

    Chaty, S; Hynes, R I; Shrader, C R; Cui, W

    2000-01-01

    We report multiwavelength observations of the two soft X-ray transients (SXTs) XTE J1859+226 and XTE J1118+480, which we observed with HST, RXTE and UKIRT. The two sources exhibited very different behaviour. XTE J1859+226 showed a thermal-viscous disc instability outburst modified by irradiation. XTE J1118+480, which we also observed with EUVE since it is located at a very high galactic latitude and suffers from very low extinction, is much more unusual. It exhibits i) a low X-ray to optical flux ratio and ii) a strong non-thermal contribution throughout the spectrum, which is likely to be due to synchrotron emission. We concentrate here on their evolution in the course of their outbursts.

  15. Transient Relativistic Ejections and Stationary Core in XTE J1752-223

    CERN Document Server

    Yang, J; Corbel, S; Gurvits, L I; Campbell, R M; Brocksopp, C

    2011-01-01

    The Galactic X-ray transient XTE J1752-223 was shown to have properties of black hole binary candidates. As reported in our previous paper, we identified transient and decelerating ejecta in multi-epoch Very Long Baseline Interferometry (VLBI) observations with the European VLBI Network (EVN) and the NRAO Very Long Baseline Array (VLBA). Here we present new EVN and VLBA data in which a new transient ejection event and later a stationary component are identified. The latter is interpreted as a reappearance of the radio core/compact jet during the transition from soft to hard X-ray state. This component appears to be highly variable in brightness although effects of tropospheric instabilities might play a role too. We also re-analyze the earlier VLBI data and find that the transient ejecta closer to the core position has significantly higher proper motion, further strengthening the case for strongly decelerating ejecta on the scale of several hundred milli-arcsecond, never observed in X-ray binaries before. Alt...

  16. INTEGRAL detects the recurrent transients XTE J1709-267 and XTE J1739-285 in outburst

    DEFF Research Database (Denmark)

    Sanchez-Fernandez, C.; Chenevez, Jérôme; Pavan, L.

    2012-01-01

    in the 20-40 keV band. We estimate a rough flux of ~8 mCrab (5 sigma) for an effective ISGRI exposure time of 21 ks. A preliminary spectral fit to the JEM-X data is consistent with an absorbed disk blackbody model of temperature ~2.2 keV. The onset of this outburst was also detected by MAXI http://maxi.......riken.jp/top/index.php?cid=1&jname=J1709-266 This new outburst from XTE J1709-267 occurs 2 years after the previous period of activity of the source, reported by MAXI/GSC (ATEL #2729), and is consistent with a outburst recurrence time of 2-3 years, claimed in ATel #1302. XTE J1739-285 was seen by JEM-X at the 9-sigma level...... in the 3-10 keV band, with an average flux of 16 +/- 2 mCrab, and at the 8-sigma level in the 10-25 keV band, with an average flux of 16 +/- 4 mCrab, for an effective exposure time of 10 ks. A weak (short) type-I X-ray burst was detected during these observations. The source flux in the 20-40 keV band...

  17. Discovery of a Transient Magnetar: XTE J1810-197

    Science.gov (United States)

    Ibrahim, Alaa I.; Markwardt, Craig B.; Swank, Jean H.; Ransom, Scott; Roberts, Mallory; Kaspi, Victoria; Woods, Peter M.; Safi-Harb, Samar; Balman, Solen; Parke, William C.

    2004-01-01

    We report the discovery of a new X-ray pulsar, XTE J1810-197, that was serendipitously discovered on 2003 July 15 by the Rossi X-Ray Timing Explorer (RXTE) while observing the soft gamma repeater SGR 1806-20. The pulsar has a 5.54 s spin period, a soft X-ray spectrum (with a photon index of approx. = 4). and is detectable in earlier RXTE observations back to 2003 January but not before. These show that a transient outburst began between 2002 November 17 and 2003 January 23 and that the source's persistent X-ray flux has been declining since then. The pulsar exhibits a high spin-down rate P approx.= l0(exp -11) s/s with no evidence of Doppler shifts due to a binary companion. The rapid spin-down rate and slow spin period imply a supercritical characteristic magnetic field B approx. = 3 x l0(exp 14) G and a young age tau less than or = 7600 yr. Follow-up Chandra observations provided an accurate position of the source. Within its error radius, the 1.5 m Russian-Turkish Optical Telescope found a limiting magnitude R(sub c) = 21.5. All such properties are strikingly similar to those of anomalous X-ray pulsars ad soft gamma repeaters, providing strong evidence that the source is a new magnetar. However, archival ASCA and ROSAT observations found the source nearly 2 orders of magnitude fainter. This transient behavior and the observed long-term flux variability of the source in absence of an observed SGR-like burst activity make it the first confirmed transient magnetar and suggest that other neutron stars that share the properties of XTE 51810- 197 during its inactive phase may be unidentified transient magnetars awaiting detection via a similar activity. This implies a larger population of magnetars than previously surmised and a possible evolutionary connection between magnetars and other neutron star families. Subject headings: pulsars: general -pulsars: individual (XTE 51810- 197) - stars: magnetic fields -

  18. XTE J1752-223 in outburst: a persistent radio jet, dramatic flaring, multiple ejections and linear polarization

    Science.gov (United States)

    Brocksopp, C.; Corbel, S.; Tzioumis, A.; Broderick, J. W.; Rodriguez, J.; Yang, J.; Fender, R. P.; Paragi, Z.

    2013-06-01

    The black hole candidate, XTE J1752-223, was discovered in 2009 October when it entered an outburst. We obtained radio data from the Australia Telescope Compact Array for the duration of the ˜9 month event. The light curves show that the radio emission from the compact jet persisted for the duration of an extended hard state and through the transition to the intermediate state. The flux then rose rapidly by a factor of 10 and the radio source entered a series of at least seven maxima, the first of which was likely to be emission associated with the compact jet. The subsequent six flares were accompanied by variable behaviour in terms of radio spectrum, degree of linear polarization, morphology and associated X-ray behaviour. They were, however, remarkably similar in terms of the estimated minimum power required to launch such an ejection event. We compare the timing of radio peaks with the location of the ejecta, imaged by contemporaneous Very Long Baseline Interferometry experiments. We then discuss the mechanism behind the events, in terms of whether discrete ejections are the most likely description of the behaviour. One ejection, at least, appears to be travelling with apparent superluminal motion. The range of properties, however, suggests that multiple mechanisms may be relevant and that at least some of the emission is coming from shocked interactions amongst the ejecta and between the ejecta and the interstellar medium. We also compare the radio flux density with the X-ray source during the hard state and conclude that XTE J1752-223 is a radio-weak/X-ray-bright outlier on the universal correlation for black hole transient sources.

  19. INTEGRAL sees Swift J174510.8-2624, Swift J1753.7-2544, XTE J1810-189, XTE J1739-285 to be still on, while 1E 1740.7-2942 is off

    NARCIS (Netherlands)

    Kuulkers, E.; Chenevez, J.; Alfonso-Garzon, J.; Beckmann, V.; Bird, T.; Brandt, S.; Courvoisier, T.; Del Santo, M.; Domingo, A.; Ebisawa, K.; Jonker, P.; Kretschmar, P.; Markwardt, C.; Oosterbroek, T.; Paizis, A.; Pottschmidt, K.; Sanchez-Fernandez, C.; Wijnands, R.

    2013-01-01

    A new season of the INTEGRAL Bulge monitoring programme (see ATel #438) started this morning (UT 2013 Feb 11 00:57-04:39). The sources Swift J174510.8-2624 (ATels #4760, #4782), Swift J1753.7-2544 (ATels #4769, #4789), XTE J1810-189 (ATel #4752) and XTE J1739-285 (ATels #4304, #4354) are still activ

  20. Near-infrared Observations of Magnetars: XTE J1810-197, 1RXS J1708-4009, 1E 1841-045 and SGR 1900+14

    CERN Document Server

    Testa, V; Mignani, R P; Israel, G L; Perna, R; Chaty, S; Stella, L; Covino, S; Turolla, R; Zane, S; Curto, G Lo; Campana, S; Marconi, G; Mereghetti, S

    2007-01-01

    . We report on near-infrared (IR) observations of the three anomalous X-ray pulsars XTE J1810-197, 1RXS J1708-4009, 1E 1841-045 and the soft gamma-ray repeater SGR 1900+14, taken with the ESO-VLT, the Gemini, and the CFHT telescopes. . This work is aimed at identifying and/or confirming the IR counterparts of these magnetars, as well as at measuring their possible IR variability. . In order to perform photometry of objects as faint as Ks~20, we have used data taken with the largest telescopes, equipped with the most advanced IR detectors and in most of the cases with Adaptive Optics devices. The latter are critical to achieve the sharp spatial accuracy required to pinpoint faint objects in crowded fields. . We confirm with high confidence the identification of the IR counterpart to XTE J1810-197, and its IR variability. For 1E 1841-045 and SGR 1900+14 we propose two candidate IR counterparts based on the detection of IR variability. For 1RXS J1708-4009 we show that none of the potential counterparts within th...

  1. VLT spectroscopy of XTE J2123-058 during quiescence

    CERN Document Server

    Casares, J; Shahbaz, T; Zurita, C; Charles, P A

    2001-01-01

    We present VLT low resolution spectroscopy of the neutron star X-ray transient XTE J2123-058 during its quiescent state. Our data reveal the presence of a K7V companion which contributes 77 % to the total flux at 6300 A and orbits the neutron star at K_2 = 287 +/- 12 km/s. Contrary to other soft X-ray transients (SXTs), the Halpha emission is almost exactly in antiphase with the velocity curve of the optical companion. Using the light-center technique we obtain K_1 = 140 +/- 27 km/s and hence q=K_1/K_2=M_2/M_1= 0.49 +/- 0.10. This, combined with a previous determination of the inclination angle (i=73 +/- 4) yields M_1 = 1.55 +/- 0.31 Msun and M_2 = 0.76 +/- 0.22 Msun. M_2 agrees well with the observed spectral type. Doppler tomography of the Halpha emission shows a non-symmetric accretion disc distribution mimicking that seen in SW Sex stars. Although we find a large systemic velocity of -110 +/- 8 km/s this value is consistent with the galactic rotation velocity at the position of J2123-058, and hence a halo...

  2. Study of the Mg incorporation in CdTe for developing wide band gap Cd{sub 1-x}Mg{sub x}Te thin films for possible use as top-cell absorber in a tandem solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Omar S. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Universidad Politecnica del Estado de Guerrero, Comunidad de Puente Campuzano, C.P. 40325 Taxco de Alarcon, Guerrero (Mexico); Millan, Aduljay Remolina [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Huerta, L.; Santana, G. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico. C.P 04510 Mexico D.F. (Mexico); Mathews, N.R.; Ramon-Garcia, M.L.; Morales, Erik R. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Mathew, X., E-mail: xm@cie.unam.mx [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Thin films of Cd{sub 1-x}Mg{sub x}Te with high spatial uniformity and band gap in the range of 1.6-1.96 eV were deposited by vacuum co-evaporation of CdTe and Mg. Black-Right-Pointing-Pointer Obtained Cd{sub 1-x}Mg{sub x}Te films have the structural characteristics of the CdTe, evidence of the change in atomic scattering due to incorporation of Mg was observed. Black-Right-Pointing-Pointer XRD and XPS data confirmed the incorporation of Mg in the lattice of CdTe. Black-Right-Pointing-Pointer SEM images revealed the impact of Mg incorporation on the morphology of the films, the changes in grain size and grain morphology are noticeable. - Abstract: Thin films of Cd{sub 1-x}Mg{sub x}Te with band gap in the range of 1.6-1.96 eV were deposited by vacuum co-evaporation of CdTe and Mg on glass substrates heated at 300 Degree-Sign C. Different experimental techniques such as XRD, UV-vis spectroscopy, SEM, and XPS were used to study the effect of Mg incorporation into the lattice of CdTe. The band gap of the films showed a clear tendency to increase as the Mg content in the film is increased. The Cd{sub 1-x}Mg{sub x}Te films maintain all the structural characteristics of the CdTe, however, diminishing of intensity for the XRD patterns is observed due to both change in preferential orientation and change in atomic scattering due to the incorporation of Mg. SEM images showed significant evidences of morphological changes due to the presence of Mg. XRD, UV-vis spectroscopy, and XPS data confirmed the incorporation of Mg in the lattice of CdTe. The significant increase in band gap of CdTe due to incorporation of Mg suggests that the Cd{sub 1-x}Mg{sub x}Te thin film is a candidate material to use as absorber layer in the top-cell of a tandem solar cell.

  3. Evolution of the X-ray Properties of the Transient Magnetar XTE J1810-197

    CERN Document Server

    Alford, Jason

    2016-01-01

    We report on X-ray observations of the 5.54 s transient magnetar XTE J1810-197 using the XMM-Newton and Chandra observatories, analyzing new data from 2008 through 2014, and re-analyzing data from 2003 through 2007 with the benefit of these six years of new data. From the discovery of XTE J1810-197 during its 2003 outburst to the most recent 2014 observations, its 0.3-10 keV X-ray flux has declined by a factor of about 50 from 4.1E-11 to 8.1E-13 erg/cm^2/s. Its X-ray spectrum has now reached a steady state. Pulsations continue to be detected from a 0.3 keV thermal hot-spot that remains on the neutron star surface. The luminosity of this hot-spot exceeds XTE J1810-197's spin down luminosity, indicating continuing magnetar activity. We find that XTE J1810-197's X-ray spectrum is best described by a multiple component blackbody model in which the coldest 0.14 keV component likely originates from the entire neutron star surface, and the thermal hot-spot is, at different epochs, well described by an either one or ...

  4. INTEGRAL monitoring of the X-ray burster XTE J1739-285

    DEFF Research Database (Denmark)

    Sánchez-Fernández, C.; Kuulkers, E.; Chenevez, Jérôme;

    2008-01-01

    XTE J1739-285 is a recurrent X-ray transient first discovered by INTEGRAL as an X-ray burster. We have carried out a systematic search for X-ray bursts at various levels of accretion rate onto the Neutron Star surface during the source outbursts in 2005 and 2006. A total of 25 X-ray bursts were f...

  5. Evolution of the X-ray Properties of the Transient Magnetar XTE J1810-197

    Science.gov (United States)

    Alford, Jason

    2016-04-01

    We report on X-ray observations of the 5.54 s transient magnetar XTE J1810-197 using the XMM-Newton and Chandra observatories, analyzing new data from 2008 through 2014, and re-analyzing data from 2003 through 2007 with the benefit of these six years of new data. From the discovery of XTE J1810-197 during its 2003 outburst to the most recent 2014 observations, its 0.3-10 keV X-ray flux has declined by a factor of about 50 from 4.1E-11 to 8.1E-13 erg/cm^2/s. Its X-ray spectrum has now reached a steady state. Pulsations continue to be detected from a 0.3 keV thermal hot-spot that remains on the neutron star surface. The luminosity of this hot-spot exceeds XTE J1810-197's spin down luminosity, indicating continuing magnetar activity. We find that XTE J1810-197's X-ray spectrum is best described by a multiple component blackbody model in which the coldest 0.14 keV component likely originates from the entire neutron star surface, and the thermal hot-spot is, at different epochs, well described by an either one or two-component blackbody model. A 1.2 keV absorption line, possibly due to resonant proton scattering, is detected at all epochs. The X-ray flux of the hot spot decreased by approximately 20% between 2008 March and 2009 March, the same period during which XTE J1810-197 became radio quiet.

  6. NIR and optical observations of the failed outbursts of black hole binary XTE J1550-564

    CERN Document Server

    Curran, P A

    2013-01-01

    A number of low mass X-ray binaries (LMXBs) undergo "failed outbursts" in which, instead of evolving through the canonical states, they remain in a hard state throughout the outburst. While the sources of X-ray and radio emission in the hard state are relatively well understood, the origin of the near infrared (NIR) and optical emission is more complex though it likely stems from an amalgam of different emission processes, occurring as it does, at the intersecting wavelengths of those processes. We aim to identify the NIR/optical emission region(s) during a number of failed outbursts of one such low mass X-ray binary and black hole candidate, XTE J1550-564, in order to confirm or refute their classification as hard-state, failed outbursts. We present unique NIR/optical images and spectra, obtained with the ESO-New Technology Telescope, during the failed outbursts of 2001 and 2000. We compare the NIR/optical photometric, timing, and spectral properties with those expected for the different emission mechanisms ...

  7. XTE J1752-223 in outburst: a persistent radio jet, dramatic flaring, multiple ejections and linear polarisation

    CERN Document Server

    Brocksopp, Catherine; Tzioumis, Tasso; Broderick, Jess; Rodriguez, Jerome; Yang, Jun; Fender, Rob; Paragi, Zsolt

    2013-01-01

    The black hole candidate, XTE J1752-223, was discovered in 2009 October when it entered an outburst. We obtained radio data from the Australia Telescope Compact Array for the duration of the ~9 month event. The lightcurves show that the radio emission from the compact jet persisted for the duration of an extended hard state and through the transition to the intermediate state. The flux then rose rapidly by a factor of 10 and the radio source entered a series of at least 7 maxima, the first of which was likely to be emission associated with the compact jet. The subsequent 6 flares were accompanied by variable behaviour in terms of radio spectrum, degree of linear polarisation, morphology and associated X-ray behaviour. They were, however, remarkably similar in terms of the estimated minimum power required to launch such an ejection event. We compare the timing of radio peaks with the location of the ejecta, imaged by contemporaneous VLBI experiments. We then discuss the mechanism behind the events, in terms of...

  8. A decelerating jet observed by the EVN and VLBA in the X-ray transient XTE J1752-223

    CERN Document Server

    Yang, J; Corbel, S; Paragi, Z; Tzioumis, T; Fender, R P

    2010-01-01

    The recently discovered Galactic X-ray transient XTE J1752-223 entered its first known outburst in 2010, emitting from the X-ray to the radio regimes. Its general X-ray properties were consistent with those of a black hole candidate in various spectral states, when ejection of jet components is expected. To verify this, we carried out very long baseline interferometry (VLBI) observations. The measurements were carried out with the European VLBI Network (EVN) and the Very Long Baseline Array (VLBA) at four epochs in 2010 February. The images at the first three epochs show a moving jet component that is significantly decelerated by the last epoch, when a new jet component appears that is likely to be associated with the receding jet side. The overall picture is consistent with an initially mildly relativistic jet, interacting with the interstellar medium or with swept-up material along the jet. The brightening of the receding ejecta at the final epoch can be well explained by initial Doppler deboosting of the e...

  9. DETERMINATION OF THE INCOMMENSURATELY MODULATED STRUCTURE OF NI3+/-XTE2

    NARCIS (Netherlands)

    SCHUTTE, WJ; DEBOER, JL

    1993-01-01

    The modulated structure of nickel telluride Ni3+/-xTe2 (Ni2.76Te2) is stabilized at 300 K by the substitution of a small amount of Fe (prepared as Ni2.57Fe0.29Te2). The structure of this compound has been determined by X-ray diffraction at room temperature (1311 unique reflections). The structure is

  10. XTE J1751-305 going back to its quiescent state

    NARCIS (Netherlands)

    Linares, M.; Wijnands, R.; van der Klis, M.

    2007-01-01

    After the recent reports of activity of the accreting millisecond pulsar XTE J1751-305 (ATELs #1045, #1046 and #1051) we obtained another Swift/XRT (~4.3ksec) observation of the field starting on April 11th 2007 23:59. The source was not detected with a 2-10 keV upper limit of ~5E-14 erg/ cm2/s, cor

  11. Radio detection of XTE J1752-223 with the ATCA

    Science.gov (United States)

    Brocksopp, Catherine; Corbel, Stephane; Tzioumis, Tasso; Fender, Rob

    2009-11-01

    Following the detection of the new X-ray transient, XTE J1752-223, by RXTE and Swift (ATel. #2258; see also ATels. #2259, #2261, #2263, #2265, #2268, #2269), we have performed radio observations with the Australia Telescope Compact Array and the new CABB back-end. Data were obtained at 5.5 GHz and 9 GHz on October 30 and November 1. We detect a radio source at a position consistent with the X-ray coordinates.

  12. X-ray softening during the 2008 outburst of XTE J1810-189

    CERN Document Server

    Weng, Shan-Shan; Yi, Shu-Xu; Rong, Yu; Gao, Xu-Dong

    2015-01-01

    XTE J1810-189 underwent an outburst in 2008, and was observed over $\\sim 100$ d by RXTE. Performing a time-resolved spectral analysis on the photospheric radius expansion burst detected on 2008 May 4, we obtain the source distance in the range of 3.5--8.7 kpc for the first time. During its outburst, XTE J1810-189 did not enter into the high/soft state, and both the soft and hard colours decreased with decreasing flux. The fractional rms remained at high values ($\\sim 30$ per cent). The RXTE/PCA spectra for 3-25 keV can be described by an absorbed power-law component with an additional Gaussian component, and the derived photon index $\\Gamma$ increased from $1.84\\pm0.01$ to $2.25\\pm0.04$ when the unabsorbed X-ray luminosity in 3-25 keV dropped from $4\\times10^{36}$ ergs s$^{-1}$ to $6\\times10^{35}$ ergs s$^{-1}$. The relatively high flux, dense observations and broadband spectra allow us to provide strong evidence that the softening behaviour detected in the outburst of XTE J1810-189 originates from the evolut...

  13. Looking into the Theory of Pulsar Accretion: Cen X-3 and XTE J1946+274

    CERN Document Server

    Marcu, Diana M; Gottlieb, Amy M; Wolff, Michael T; Becker, Peter A; Wilms, Joern; Ferrigno, Carlo; Wood, Kent S

    2015-01-01

    This is an overview of pulsar accretion modeling. The physics of pulsar accretion, i.e., the process of plasma flow onto the neutron star surface, can be constrained from the spectral properties of the X-ray source. We discuss a new implementation of the physical continuum model developed by Becker and Wolff (2007, ApJ 654, 435). The model incorporates Comptonized blackbody, bremsstrahlung, and cyclotron emission. We discuss preliminary results of applying the new tool to the test cases of Suzaku data of Cen X-3 and XTE J1946+274. Cen X-3 is a persistent accreting pulsar with an O-star companion observed during a bright period. XTE J1946+274 is a transient accreting pulsar with a Be companion observed during a dim period. Both sources show spectra that are well described with an empirical Fermi Dirac cutoff power law model. We extend the spectral analysis by making the first steps towards a physical description of Cen X-3 and XTE J1946+274.

  14. The kilohertz quasi-periodic oscillations during the Z and atoll phases of the unique transient XTE J1701-462

    NARCIS (Netherlands)

    Sanna, Andrea; Méndez, Mariano; Altamirano, Diego; Homan, Jeroen; Casella, Piergiorgio; Belloni, Tomaso; Lin, Dacheng; van der Klis, Michiel; Wijnands, Rudy

    2010-01-01

    We analysed 866 observations of the neutron star low-mass X-ray binary XTE J1701-462 during its 2006-2007 outburst. XTE J1701-462 is the only example so far of a source that during an outburst showed, beyond any doubt, spectral and timing characteristics both of the Z and atoll type. There are 707 R

  15. The kilohertz quasi-periodic oscillations during the Z and atoll phases of the unique transient XTE J1701−462

    NARCIS (Netherlands)

    Sanna, A.; Méndez, M.; Altamirano, D.; Homan, J.; Casella, P.; Belloni, T.; Lin, D.; van der Klis, M.; Wijnands, R.

    2010-01-01

    We analysed 866 observations of the neutron star low-mass X-ray binary XTE J1701−462 during its 2006-2007 outburst. XTE J1701−462 is the only example so far of a source that during an outburst showed, beyond any doubt, spectral and timing characteristics both of the Z and atoll type. There are 707 R

  16. The Fading of Transient Anomalous X-Ray Pulsar XTE J1810-197

    Science.gov (United States)

    Halpern, J. P.; Gotthelf, E. V.

    2005-01-01

    Three observations of the 5.54 s transient anomalous X-ray pulsar XTE J1810-197 obtained over 6 months with the Newton X-ray Multi-Mirror (XMM-Newton) mission are used to study its spectrum and pulsed light curve as the source fades from outburst. The decay is consistent with an exponential of time constant ~300 days but not a power law as predicted in some models of sudden deep crustal heating events. All spectra are well fitted by a blackbody plus a steep power law, a problematic model that is commonly fitted to anomalous X-ray pulsars (AXPs). A two-temperature blackbody fit is also acceptable and better motivated physically in view of the faint optical/IR fluxes, the X-ray pulse shapes that weakly depend on energy in XTE J1810-197, and the inferred emitting areas that are less than or equal to the surface area of a neutron star. The fitted temperatures remained the same while the flux declined by 46%, which can be interpreted as a decrease in area of the emitting regions. The pulsar continues to spin down, albeit at a reduced rate of (5.1+/-1.6)×10-12 s s-1. The inferred characteristic age τc≡P/2P~17,000 yr, magnetic field strength Bs~1.7×1014 G, and outburst properties are consistent with both the outburst and quiescent X-ray luminosities being powered by magnetic field decay, i.e., XTE J1810-197 is a magnetar.

  17. A Survey of Variable Extragalactic Sources with XTE's All Sky Monitor (ASM)

    Science.gov (United States)

    Jernigan, Garrett

    1998-01-01

    The original goal of the project was the near real-time detection of AGN utilizing the SSC 3 of the ASM on XTE which does a deep integration on one 100 square degree region of the sky. While the SSC never performed sufficiently well to allow the success of this goal, the work on the project has led to the development of a new analysis method for coded aperture systems which has now been applied to ASM data for mapping regions near clusters of galaxies such as the Perseus Cluster and the Coma Cluster. Publications are in preparation that describe both the new method and the results from mapping clusters of galaxies.

  18. ATCA detection of increased radio emission from XTE J1752-223

    Science.gov (United States)

    Brocksopp, Catherine; Corbel, Stephane; Tzioumis, Tasso; Fender, Rob; Coriat, Mickael

    2010-01-01

    Following the announcement that the new X-ray transient source, XTE J1752-223 (ATel. 2258), is making a transition from the hard to the intermediate state (ATel. 2387, 2391, 2396), we have observed the radio counterpart with the Australia Telescope Compact Array and the new CABB back-end. The radio source has risen from the previous ~2 mJy plateau to 20 mJy at 1.2, 2.5, 5.5, 9, 17, 19 GHz on January 21.

  19. The Variable Quiescent X-Ray Emission of the Neutron Star Transient XTE J1701-462

    NARCIS (Netherlands)

    Fridriksson, Joel K.; Homan, J.; Wijnands, R.; Cackett, E. M.; Degenaar, N.; Mendez, M.; Altamirano, D.; Brown, E. F.; Belloni, T. M.; Lewin, W. H. G.

    2011-01-01

    We have monitored the cooling of the neutron star in the transient low-mass X-ray binary XTE J1701-462 with Chandra and XMM-Newton since the source entered quiescence in 2007 after an exceptionally luminous 19-month outburst. A recent Chandra observation made almost 1200 days into quiescence indicat

  20. INTEGRAL Long-Term Monitoring of the Supergiant Fast X-Ray Transient XTE J1739-302

    Science.gov (United States)

    Blay, P.; Martinez-Nunez, S.; Negueruela, I.; Pottschmidt, K.; Smith, D. M.; Torrejon, J. M.; Reig, P.; Kretschmar, P.; Kreykenbohm, I.

    2008-01-01

    Context. In the past few years, a new class of High Mass X-Ray Binaries (HMXRB) has been claimed to exist, the Supergiant Fast X-ray Transients (SFXT). These are X-ray binary systems with a compact companion orbiting a supergiant star which show very short and bright outbursts in a series of activity periods overimposed on longer quiescent periods. Only very recently the first attempts to model the behaviour of these sources have been published, some of them within the framework of accretion from clumpy stellar winds. Aims. Our goal is to analyze the properties of XTE J1739-302/IGR J17391-3021 within the context of the clumpy structure of the supergiant wind. Methods. We have used INTEGRAL and RXTE/PCA observations in order to obtain broad band (1 - 200 keV) spectra and light curves of XTE J1739-302 and investigate its X-ray spectrum and temporal variability. Results. We have found that XTE J1739-302 follows a much more complex behaviour than expected. Far from presenting a regular variability pattern, XTE J1739-302 shows periods of high, intermediate, and low flaring activity.

  1. RXTE and BeppoSAX Observations of XTE J1859+083

    Science.gov (United States)

    Corbet, Robin H. D.; in't Zand, J. J. M.; Levine, A. M.; Marshall, F. E.

    2008-03-01

    The transient X-ray source XTE J1859+083, which has a pulse period of 9.8s, was discovered with RXTE in 1999. There have been no reports of more recent detections of this source. We present here observations of this pulsar made with the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) on board RXTE, and the Wide Field Cameras (WFC) on board BeppoSax. Eighteen sets of PCA observations were obtained over an approximately one month period in 1999. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD 50,250 and 50,460. The ASM data excluding this outburst interval suggest a possible 61 day modulation. The PCA flux and pulse timing measurements are consistent with this possible period. Observations with the WFC during the outburst give an error box which is consistent with the PCA error box but is significantly smaller. The transient nature of XTE J1859+083 and the length of its pulse period are consistent with it being a Be/neutron star binary. The possible 61 day orbital period would be of the expected length for a Be star system with a 9.8s pulse period.

  2. The variable spin-down rate of the transient magnetar XTE J1810-197

    Science.gov (United States)

    Pintore, Fabio; Bernardini, Federico; Mereghetti, Sandro; Esposito, Paolo; Turolla, Roberto; Rea, Nanda; Coti Zelati, Francesco; Israel, Gian Luca; Tiengo, Andrea; Zane, Silvia

    2016-05-01

    We have analysed XMM-Newton and Chandra observations of the transient magnetar XTE J1810-197 spanning more than 11 yr, from the initial phases of the 2003 outburst to the current quiescent level. We investigated the evolution of the pulsar spin period and we found evidence for two distinct regimes: during the outburst decay, dot{ν } was highly variable in the range -(2-4.5) × 10-13 Hz s-1, while during quiescence the spin-down rate was more stable at an average value of -1 × 10-13 Hz s-1. Only during ˜3000 d (from MJD 54165 to MJD 56908) in the quiescent stage it was possible to find a phase-connected timing solution, with dot{ν }=-4.9× 10^{-14} Hz s-1, and a positive second frequency derivative, ddot{ν }=1.8× 10^{-22} Hz s-2. These results are in agreement with the behaviour expected if the outburst of XTE J1810-197 was due to a strong magnetospheric twist.

  3. X-ray Observation of XTE J2012+381 during the 1998 Outburst

    Indian Academy of Sciences (India)

    S. Naik; P. C. Agrawal; B. Paul; A. R. Rao; S. Seetha; Κ. Kasturirangan

    2000-06-01

    The outburst of X-ray transient source XTE J2012+381 was detected by the RXTE All-Sky Monitor on 1998 May 24th. Following the outburst, X-ray observations of the source were made in the 2-18keV energy band with the Pointed Proportional Counters of the Indian X-ray Astronomy Experiment (IXAE) on-board the Indian satellite IRS-P3 during 1998 June 2nd-10th. The X-ray flux of the source in the main outburst decreased exponentially during the period of observation. No large amplitude short-term variability in the intensity is detected from the source. The power density spectrum obtained from the timing analysis of the data shows no indication of any quasi-periodic oscillations in 0.002-0.5 Hz band. The hardness ratio i.e. the ratio of counts in 6-18 keV to 2-6 keV band, indicates that the X-ray spectrum is soft with spectral index > 2. From the similarities of the X-ray properties with those of other black hole transients, we conclude that the X-ray transient XTE J2012+381 is likely to be a black hole.

  4. The accretion rate independence of horizontal branch oscillation in XTE J1701-462

    CERN Document Server

    Li, Zhaosheng; Qu, Jinlu; Bu, Qingcui; Wang, Dehua; Xu, Renxin

    2014-01-01

    We study the temporal and energy spectral properties of the unique neutron star low-mass X-ray binary XTE J1701-462. After assuming the HB/NB vertex as a reference position of accretion rate, the horizontal branch oscillation (HBO) of the HB/NB vertex is roughly 50 Hz. It indicates that the HBO is independent with the accretion rate or the source intensity. The spectral analysis shows $R_{\\rm{in}}\\propto\\dot{M}_{\\rm{Disk}}^{2.9\\pm0.09}$ in the HB/NB vertex and $R_{\\rm{in}}\\propto\\dot{M}_{\\rm{Disk}}^{1.7\\pm0.06}$ in the NB/FB vertex, which implies that different accretion rate may be produced in the HB/NB vertex and the NB/FB vertex. The Comptonization component could be fitted by constrained broken power law (CBPL) or nthComp. Different with GX 17+2, the frequencies of HBO positively correlate with the inner disk radius, which contradict with the prediction of Lense-Thirring precession model. XTE J1701-462, both in the Cyg-like phase and in the Sco-like phase, follows a positive correlation between the break ...

  5. Is XTE J1739-285 a quark star masquerading as a neutron star

    CERN Document Server

    Xiaoping, Zheng; Li, Zhang

    2007-01-01

    The recent discovery of burst oscillation at 1122Hz in the X-ray transient XTE J1739-285 supports the suggestion that it contains a submillisecond pulsar\\cite{1}. We here find for the first time the enormous dissipation effect in the transition boundary layer between quark matter core and hadron matter envelope. Just combining the estimation with previous dissipation mechanism together, we show that XTE J1739-285 can be uniquely restricted to a quark star masquerading as a neutron star (hybrid star) that contains a pure quark matter or mixed quark-hadron matter core from synthesizing both gravitational wave radiation (r-mode) instability and Keplerian motion constraints at 1122Hz lever. Such constraints allow the radii in the range $9{\\rm km}\\leq R\\leq 12{\\rm km}$ and the masses in the range $1.2M_\\odot\\leq M\\leq 2.0M_\\odot$. The normal neutron stars, hyperon stars and strange stars within the mass-radius limits are excluded.

  6. Detailed Radio to Soft Gamma-ray Studies of the 2005 Outburst of the New X-ray Transient XTE J1818-245

    CERN Document Server

    Bel, M Cadolle; Rodríguez, J; Ribó, M; Barragan, L; D'Avanzo, P; Hannikainen, D C; Kuulkers, E; Campana, S; Moldon, J; Chaty, S; Zurita-Heras, J; Goldwurm, A; Goldoni, P

    2009-01-01

    XTE J1818-245 is an X-ray nova that experienced an outburst in 2005, first seen by the RXTE satellite. The source was observed simultaneously at various wavelengths up to soft gamma-rays with the INTEGRAL satellite, from 2005 February to September. X-ray novae are extreme systems that often harbor a black hole, and are known to emit throughout the electromagnetic spectrum when in outburst. We analyzed radio, (N)IR, optical, X-ray and soft gamma-ray observations and constructed simultaneous broad-band X-ray spectra. Analyzing both the light curves in various energy ranges and the hardness-intensity diagram enabled us to study the long-term behavior of the source. Spectral parameters were typical of the Soft Intermediate States and the High Soft States of a black hole candidate. The source showed relatively small spectral variations in X-rays with considerable flux variation in radio. Spectral studies showed that the accretion disc cooled down from 0.64 to 0.27 keV in 100 days and that the total flux decreased ...

  7. Multi-state observations of the Galactic Black Hole XTE J1752-223: Evidence for an intermediate black hole spin

    CERN Document Server

    Reis, R C; Fabian, A C; Cackett, E M; Maitra, D; Reynolds, C S; Rupen, M; Steeghs, D T H; Wijnands, R

    2010-01-01

    The Galactic Black hole candidate XTE J1752-223 was observed during the decay of its 2009 outburst with the Suzaku and XMM-Newton observatories. The observed spectra are consistent with the source being in the ''intermediate`` and ''low-hard state`` respectively. The presence of a strong, relativistic iron emission line is clearly detected in both observations and the line profiles are found to be remarkably consistent and robust to a variety of continuum models. This strongly points to the compact object in \\j\\ being a stellar-mass black hole accretor and not a neutron star. Physically-motivated and self-consistent reflection models for the Fe-\\ka\\ emission-line profile and disk reflection spectrum rule out either a non-rotating, Schwarzchild black hole or a maximally rotating, Kerr black hole at greater than 3sigma level of confidence. Using a fully relativistic line function in which the black hole spin parameter is a variable, we have formally constrained the spin parameter to be $0.52\\pm0.11 (1\\sigma)$. ...

  8. The Rossi X-Ray Timing Explorer (XTE) Solar Array Anomaly

    Science.gov (United States)

    Gaddy, Edward M.; Kichak, Robert; Niemeyer, Lee; Stegeman, Richard

    2004-01-01

    The XTE was launched December 30, 1995. Shortly after launch, it become apparent that the solar array was not performing as expected. On leaving shadow, the array exhibited many discontinuous drops in current output. The size of each of these drops was consistent with the loss of a part of a sell. The current decreases could not be caused by the loss of an entire circuit. This meant that the array may have had numerous cracked solar cells that opened as array got warmer. Studies performed on the array's qualification panel suggest that the cell cracks may have been cased by extensive tap testing performed on the array and that these cracks were undetectable at room temperature using usual inspection method.

  9. Evolution of a low frequency QPO during the 2000 outburst of XTE J1550-564

    CERN Document Server

    Rodríguez, J; Kalemci, E; Tomsick, J A; Tagger, M

    2002-01-01

    We follow the evolution of a low frequency QPO during the 2000 outburst of the microquasar XTE J1550-564, which was found to be present in the PCA energy range (2-65 keV) in 19 of 43 observations. The frequency of the QPO varies from 0.1 Hz to 6 Hz, and appears to follow the evolution of the soft X-ray flux. If we assume the soft X-rays represent the behavior of an accretion disk, the relation indicates that this low frequency QPO is linked to the accretion disk. We show that the non-trivial relation between the QPO frequency and the soft flux may be as expected from the Accretion Ejection Instability (AEI), when the disk approaches its last stable orbit. Furthermore, the energy dependence of the QPO may indicate the presence of a hot spot rotating in the disk as predicted by the AEI.

  10. Spectrum of jet emitting disc: Application to microquasar XTE J1118+480

    CERN Document Server

    Zhang, Jian-Fu

    2013-01-01

    Under the framework of the magnetized accretion ejection structures, we analyze the energy balance properties, and study the spectral energy distributions (SEDs) of the Jet Emitting Disc (JED) model for black hole X-ray transients. Various radiative processes are considered, i.e. synchrotron, bremsstrahlung, and their Comptonizations, and external Comptonization of radiation from outer thin disc. With these cooling terms taken into account, we solve the thermal equilibrium equation self-consistently and find three solutions, of which the cold and the hot solutions are stable. Subsequently we investigate the theoretical SEDs for these two stable solutions.We find the hot JED model can naturally explain the spectra of the Galactic microquasars in their hard states. As an example, we apply this model to the case of XTE J1118+480.

  11. XTE J1739-302 An Unusual New X-ray Transient

    CERN Document Server

    Smith, D M; Marshall, F; Swank, J H; Heindl, W A; Leventhal, M; in 't Zand, J J M; Heise, J

    1998-01-01

    A new x-ray transient, designated XTE J1739-302, was discovered with the Proportional Counter Array (PCA) on the Rossi X-ray Timing Explorer (RXTE) in data from 12 August 1997. Although it was the brightest source in the Galactic Center region while active (about 3.0 x 10^-9 ergs/cm2/s from 2 to 25 keV), it was only observed on that one day; it was not detectable nine days earlier or two days later. There is no known counterpart at other wavelengths, and its proximity to the Galactic Center will make such an identification difficult due to source confusion and extinction. The x-ray spectrum and intensity suggest a giant outburst of a Be/neutron star binary, although no pulsations were observed and the outburst was shorter than is usual from these systems.

  12. SUBARCSECOND LOCATION OF IGR J17480-2446 WITH ROSSI XTE

    Energy Technology Data Exchange (ETDEWEB)

    Riggio, A. [INAF-Osservatorio Astronomico di Cagliari, localita Poggio dei Pini, Strada 54, 09012 Capoterra (Italy); Burderi, L.; Egron, E. [Dipartimento di Fisica, Universita di Cagliari, SP Monserrato-Sestu km 0,7, 09042 Monserrato (Canada) (Italy); Di Salvo, T.; D' Ai, A.; Iaria, R.; Robba, N. R. [Dipartimento di Fisica, Universita di Palermo, Via Archirafi 36, Palermo 90123 (Italy); Papitto, A. [Institut de Ciencies de lEspai (IEEC-CSIC), Campus UAB, Fac. de Ciencies, Torre C5, parell, 2a planta, 08193 Barcelona (Spain); Belloni, T.; Motta, S. [INAF-Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (Italy); Floris, M. [CRS4-Center for Advanced Studies, Research and Development in Sardinia, Loc. Piscina Manna, Edificio 1, 09010 Pula (Italy); Testa, V.; Menna, M. T., E-mail: ariggio@oa-cagliari.inaf.it [INAF-Osservatorio Astronomico di Roma. Via Frascati, 33, 00040 Monte Porzio Catone (Italy)

    2012-07-20

    On 2010 October 13, the X-ray astronomical satellite Rossi XTE, during the observation of the newly discovered accretion powered X-ray pulsar IGR J17480-2446, detected a lunar occultation of the source. From knowledge of the lunar topography and Earth, Moon, and spacecraft ephemerides at the epoch of the event, we determined the source position with an accuracy of 40 mas (1{sigma} c.l.), which is interesting, given the very poor imaging capabilities of RXTE ({approx}1 Degree-Sign ). For the first time, using a non-imaging X-ray observatory, the position of an X-ray source with a subarcsecond accuracy is derived, demonstrating the neat capabilities of a technique that can be fruitfully applied to current and future X-ray missions.

  13. Strongly absorbed quiescent X-ray emission from the X-ray transient XTE J0421+56

    CERN Document Server

    Boirin, L; Lumb, D H; Orlandini, M; Schartel, N

    2002-01-01

    We have observed the soft X-ray transient XTE J0421+56 in quiescence with XMM-Newton. The observed spectrum is highly unusual being dominated by a broad feature at 6.5 keV and can be modeled by a strongly absorbed continuum. The spectra of X-ray transients observed so far are normally modeled using Advection Dominated Accretion Flow models, black-bodies, power-laws, or by the thermal emission from a neutron star surface. The strongly absorbed X-ray emission of XTE J0421+56 could result from the compact object being embedded within the dense circumstellar wind emitted from the supergiant B[e] companion star.

  14. Timing and spectral analysis of the unusual X-ray transient XTE J0421+560/CI Camelopardalis

    NARCIS (Netherlands)

    Bartlett, E.S.; Clark, J.S.; Coe, M.J.; Garcia, M.G.; Uttley, P.

    2013-01-01

    We present a detailed X-ray study of the 2003 XMM-Newton observation of the high-mass X-ray binary XTE J0421+560/CI Camelopardalis. The continuum of the X-ray spectrum is well described by a flat power law (Γ = 1.0 ± 0.2) with a large intrinsic absorbing column (NH = (4.4 ± 0.5) × 1023 cm−2). We hav

  15. Radio Disappearance of the Magnetar XTE J1810-197 and Continued X-ray Timing

    Science.gov (United States)

    Camilo, F.; Ransom, S. M.; Halpern, J. P.; Alford, J. A. J.; Cognard, I.; Reynolds, J. E.; Johnston, S.; Sarkissian, J.; van Straten, W.

    2016-04-01

    We report on timing, flux density, and polarimetric observations of the transient magnetar and 5.54 s radio pulsar XTE J1810-197 using the Green Bank, Nançay, and Parkes radio telescopes beginning in early 2006, until its sudden disappearance as a radio source in late 2008. Repeated observations through 2016 have not detected radio pulsations again. The torque on the neutron star, as inferred from its rotation frequency derivative \\dot{ν }, decreased in an unsteady manner by a factor of three in the first year of radio monitoring, until approximately mid-2007. By contrast, during its final year as a detectable radio source, the torque decreased steadily by only 9%. The period-averaged flux density, after decreasing by a factor of 20 during the first 10 months of radio monitoring, remained relatively steady in the next 22 months, at an average of 0.7 ± 0.3 mJy at 1.4 GHz, while still showing day-to-day fluctuations by factors of a few. There is evidence that during this last phase of radio activity the magnetar had a steep radio spectrum, in contrast to earlier flat-spectrum behavior. No secular decrease presaged its radio demise. During this time, the pulse profile continued to display large variations; polarimetry, including of a new profile component, indicates that the magnetic geometry remained consistent with that of earlier times. We supplement these results with X-ray timing of the pulsar from its outburst in 2003 up to 2014. For the first 4 years, XTE J1810-197 experienced non-monotonic excursions in frequency derivative by at least a factor of eight. But since 2007, its \\dot{ν } has remained relatively stable near its minimum observed value. The only apparent event in the X-ray record that is possibly contemporaneous with the radio shutdown is a decrease of ≈20% in the hot-spot flux in 2008-2009, to a stable, minimum value. However, the permanence of the high-amplitude, thermal X-ray pulse, even after the (unexplained) radio demise, implies

  16. Radio disappearance of the magnetar XTE J1810-197 and continued X-ray timing

    CERN Document Server

    Camilo, F; Halpern, J P; Alford, J A J; Cognard, I; Reynolds, J E; Johnston, S; Sarkissian, J; van Straten, W

    2016-01-01

    We report on timing, flux density, and polarimetric observations of the transient magnetar and 5.54 s radio pulsar XTE J1810-197 using the GBT, Nancay, and Parkes radio telescopes beginning in early 2006, until its sudden disappearance as a radio source in late 2008. Repeated observations through 2016 have not detected radio pulsations again. The torque on the neutron star, as inferred from its rotation frequency derivative f-dot, decreased in an unsteady manner by a factor of 3 in the first year of radio monitoring. In contrast, during its final year as a detectable radio source, the torque decreased steadily by only 9%. The period-averaged flux density, after decreasing by a factor of 20 during the first 10 months of radio monitoring, remained steady in the next 22 months, at an average of 0.7+/-0.3 mJy at 1.4 GHz, while still showing day-to-day fluctuations by factors of a few. There is evidence that during this last phase of radio activity the magnetar had a steep radio spectrum, in contrast to earlier be...

  17. The Swift capture of a long X-ray burst from XTE J1701-407

    CERN Document Server

    Linares, Manuel; Wijnands, Rudy; Soleri, Paolo; Degenaar, Nathalie; Curran, Peter A; Starling, Rhaana L C; van der Klis, Michiel

    2008-01-01

    XTE J1701-407 is a new transient X-ray source discovered on June 8th, 2008. More than one month later it showed a rare type of thermonuclear explosion: a long type I X-ray burst. We report herein the results of our study of the spectral and flux evolution during this burst, as well as the analysis of the outburst in which it took place. We find an upper limit on the distance to the source of 6.2 kpc by considering the maximum luminosity reached by the burst. We measure a total fluence of 3.5*10^{-6} erg/cm^2 throughout the ~20 minutes burst duration and a fluence of 2.6*10^{-3} erg/cm^2 during the first two months of the outburst. We show that the flux decay is best fitted by a power law (index ~1.6) along the tail of the burst. Finally, we discuss the implications of the long burst properties, and the presence of a second and shorter burst detected by Swift ten days later, for the composition of the accreted material and the heating of the burning layer.

  18. RXTE observations of Galactic microquasar XTE J1748-288 during its 1998 outburst

    CERN Document Server

    Revnivtsev, M G; Borozdin, K N

    1999-01-01

    We present an analysis of the RXTE observations of recently discovered Galactic microquasar XTE J1748-288 during its 1998 outburst. The spectral evolution of the source during the outburst can be considered as a sequence of three qualitatively distinct states. During the first observations corresponding to the maximum of X-ray flux the spectrum of the source was formed by the sum of the dominating hard power law component and soft thermal component, which can be described by the model of multicolor disk emission. Hard component contributed >=80% to the X-ray luminosity in 3-25 keV energy band. This spectral shape is quite different from spectra of high and low spectral states typical for Galactic black hole systems. Later on, as the X-ray source faded, its energy spectrum qualitatively changed, and first high, then low standard states have been observed. In correlation with the spectral changes the character of fast variability have changed dramatically also. Initially the power density spectrum was formed by...

  19. System mass constraints for the accreting millisecond pulsar XTE J1814-338 using Bowen fluorescence

    Science.gov (United States)

    Wang, L.; Steeghs, D.; Casares, J.; Charles, P. A.; Muñoz-Darias, T.; Marsh, T. R.; Hynes, R. I.; O'Brien, K.

    2017-04-01

    We present phase-resolved spectroscopy of the millisecond X-ray pulsar XTE J1814-338 obtained during its 2003 outburst. The spectra are dominated by high-excitation emission lines of He II λ4686, Hβ, and the Bowen blend C III/N III 4630-50 Å. We exploit the proven Bowen fluorescence technique to establish a complete set of dynamical system parameter constraints using bootstrap Doppler tomography, a first for an accreting millisecond X-ray pulsar binary. The reconstructed Doppler map of the N III λ4640 Bowen transition exhibits a statistically significant (>4σ) spot feature at the expected position of the companion star. If this feature is driven by irradiation of the surface of the Roche lobe filling companion, we derive a strict lower limit to the true radial velocity semi-amplitude K2. Combining our donor constraint with the well-constrained orbit of the neutron star leads to a determination of the binary mass ratio: q = 0.123^{+0.012}_{-0.010}. The component masses are not tightly constrained given our lack of knowledge of the binary inclination. We cannot rule out a canonical neutron star mass of 1.4 M⊙ (1.1 M⊙ mass is typical of the so-called redback pulsar binary systems (M2 ∼ 0.2 M⊙).

  20. INTEGRAL confirms that XTE J1728-295 = IGR J17285-2922

    DEFF Research Database (Denmark)

    Turler, Marc; ., .; Brandt, Søren Kristian;

    2010-01-01

    37 (12+/-2 mCrab, 6 sigma). Earlier observations on 20 Aug 23:37 - 21 Aug 03:19 do not show any source activity, with a 3-sigma upper limit of 7 mCrab (20-40 keV). By combining the three observations when the source is detected, we obtain a detection significance of 9.4 and 7.0 sigma in the 20......% confinement radius of 2.8 arcmin (Gros et al., 2003, A&A, L179) is (RA,DEC)=(262.172,-29.325), fully consistent with the location of the Swift/XRT Soft X-ray counterpart (ATel #2824). IGR J17285-2922 was not detected by JEM-X with a 3-sigma upper limit of about 12 mCrab (3-11 keV). This is consistent...... with the peak flux of 6.5 mCrab obtained for XTE J1728-295 in the 2-10 keV band with RXTE/PCA (ATel #2823). We note that the hard X-ray activity is confirmed by the Swift/BAT Hard X-ray Transient Monitor (see ATel #904), which evidences enhanced emission around the same time, and at a similar level...

  1. Comparative study of Hg xCd 1-xTe films grown on CdTe thin films previously deposited from two different techniques

    Science.gov (United States)

    Ali, A.; Abbas Shah, N.; Maqsood, A.

    2009-04-01

    High quality cadmium telluride (CdTe) thin films were grown on glass substrates with two different techniques, two evaporation source (TES) and closed space sublimation (CSS). Further to the above mercury telluride (HgTe) was then deposited by using single source on both CdTe thin films for obtaining Hg xCd 1-xTe samples. The crystalline structure of the Hg xCd 1-xTe sample grown from CSS-CdTe showed the preferential (1 1 1) orientation with smoother and larger grain size than those of TES-CdTe. The optical transmission for TES-CdTe sample was above 90% in the 1000-1500 nm range whereas it was significantly below 80% for CSS-CdTe sample. The optical transmission for TES-Hg xCd 1-xTe and CSS-Hg xCd 1-xTe was ˜60%. The resistivity at room temperature of TES-CdTe and CSS-CdTe was ˜3.33×10 9 Ω cm and ˜2.20×10 8 Ω cm, respectively, while the resistivity of TES-Hg xCd 1-xTe and CSS-Hg xCd 1-xTe samples was ˜1.73 Ω cm and ˜5.34×10 5 Ω cm, respectively. The comparative study of ternary compound prepared with the above techniques has been carried out for the first time.

  2. The formation of different phases of Cu {sub x}Te and their effects on CdTe/CdS solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J. [National Renewable Energy Laboratory (NREL), Golden, CO 80401 (United States)]. E-mail: Jie_Zhou@nrel.gov; Wu, X. [National Renewable Energy Laboratory (NREL), Golden, CO 80401 (United States); Duda, A. [National Renewable Energy Laboratory (NREL), Golden, CO 80401 (United States); Teeter, G. [National Renewable Energy Laboratory (NREL), Golden, CO 80401 (United States); Demtsu, S.H. [Department of Physics, Colorado State University, Fort Collins, CO 80523 (United States)

    2007-06-25

    Material studies and device applications of Cu {sub x}Te in an NREL-developed CdTe solar cell structured as glass/Cd{sub 2}SnO{sub 4}/ZnSnO {sub x}/CdS/CdTe are presented. The Cu {sub x}Te primary back contact was formed by evaporating a Cu layer with various thicknesses at room temperature on HNO{sub 3}/H{sub 3}PO{sub 4} (NP) solution etched CdTe layer. A post-annealing was then followed. The structural evolution and electrical properties of Cu {sub x}Te were investigated. Cu/Te ratio and post-annealing temperature are two processing parameters in this study. The Cu {sub x}Te phases are mainly controlled by the Cu/Te ratio. After a post-annealing at a low temperature, such as 100 deg. C, no Cu {sub x}Te phase transformation from its as-deposited phase was observed. A post-annealing treatment at a higher temperature, such as 250 deg. C, can reveal the stoichiometric Cu {sub x}Te phases based on the Cu/Te ratio used in the devices. But a post-annealing at a further higher temperature, such as 400 deg. C, resulted in a complicated Cu {sub x}Te phase appearance. CuTe, Cu{sub 1.4}Te, and Cu{sub 2}Te are three major phases detected by X-ray diffraction (XRD) for different Cu thickness application annealed at 250 deg. C. Application of Cu thicker than 60 nm degrades open-circuit voltage (V {sub oc}) and shunting resistance (R {sub sh}), but increases series resistance (R {sub s}). The correlation between device performance and the Cu {sub x}Te back contact illustrates that the process used for forming the Cu{sub 2}Te back contact failed to produce good fill factor (FF) and also introduced higher barrier height. The best device was observed for a back contact with a mixed Cu{sub 1.4}Te and CuTe phases.

  3. Searches for continuous gravitational waves from Scorpius X-1 and XTE J1751-305 in LIGO's sixth science run

    Science.gov (United States)

    Meadors, G. D.; Goetz, E.; Riles, K.; Creighton, T.; Robinet, F.

    2017-02-01

    Scorpius X-1 (Sco X-1) and x-ray transient XTE J1751-305 are low-mass x-ray binaries (LMXBs) that may emit continuous gravitational waves detectable in the band of ground-based interferometric observatories. Neutron stars in LMXBs could reach a torque-balance steady-state equilibrium in which angular momentum addition from infalling matter from the binary companion is balanced by angular momentum loss, conceivably due to gravitational-wave emission. Torque balance predicts a scale for detectable gravitational-wave strain based on observed x-ray flux. This paper describes a search for Sco X-1 and XTE J1751-305 in LIGO science run 6 data using the TwoSpect algorithm, based on searching for orbital modulations in the frequency domain. While no detections are claimed, upper limits on continuous gravitational-wave emission from Sco X-1 are obtained, spanning gravitational-wave frequencies from 40 to 2040 Hz and projected semimajor axes from 0.90 to 1.98 light-seconds. These upper limits are injection validated, equal any previous set in initial LIGO data, and extend over a broader parameter range. At optimal strain sensitivity, achieved at 165 Hz, the 95% confidence level random-polarization upper limit on dimensionless strain h0 is approximately 1.8 ×10-24. The closest approach to the torque-balance limit, within a factor of 27, is also at 165 Hz. Upper limits are set in particular narrow frequency bands of interest for J1751-305. These are the first upper limits known to date on r -mode emission from this XTE source. The TwoSpect method will be used in upcoming searches of Advanced LIGO and Virgo data.

  4. Growth and Characterization of Cd1−XZnXTe-Sintered Films

    Directory of Open Access Journals (Sweden)

    M. Hussain

    2007-12-01

    Full Text Available The II-VI polycrystalline semiconducting materials have come under increased scrutiny because of their wide use in the cost reduction of devices for photovoltaic applications. Cd1−XZnXTe is one of the II-VI ternary semiconductor materials whose bandgap can be tailored to any value between 1.48–2.26 eV as X varies from 0 to 1. It is promising material for high-efficiency solar cells, switching, and other optoelectronic devices. Polycrystalline thin film of Cd1−XZnXTe with variable composition (0≤X≤1 has been deposited on ultraclean glass substrates by screen printing method followed by sintering process. The optical and structural properties of Cd1−XZnXTe thin films have been examined. The optical bandgap of these films is studied using reflection spectra in wavelength range of 350–900 nm by using double beam spectrophotometer. The structure of sample was determined from X-ray diffraction patterns. The films were polycrystalline in nature having wurtzite (Hexagonal structure over the whole range studied. The lattice parameters vary almost linearly with the composition parameter X, following Vegard's law. Sintering is a very simple and viable method compared to other cost-intensive methods. The results of the present investigation will be useful in characterizing the material CdZnTe for its applications in photovoltaics.

  5. First Principles Calculations of Structural, Electronic, Thermodynamic and Thermal Properties of BaxSr1-xTe Ternary Alloys

    Science.gov (United States)

    Chelli, S.; Meradji, H.; Amara Korba, S.; Ghemid, S.; El Haj Hassan, F.

    2014-12-01

    The structural, electronic thermodynamic and thermal properties of BaxSr1-xTe ternary mixed crystals have been studied using the ab initio full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). In this approach, the Perdew-Burke-Ernzerhof-generalized gradient approximation (PBE-GGA) was used for the exchange-correlation potential. Moreover, the recently proposed modified Becke Johnson (mBJ) potential approximation, which successfully corrects the band-gap problem was also used for band structure calculations. The ground-state properties are determined for the cubic bulk materials BaTe, SrTe and their mixed crystals at various concentrations (x = 0.25, 0.5 and 0.75). The effect of composition on lattice constant, bulk modulus and band gap was analyzed. Deviation of the lattice constant from Vegard's law and the bulk modulus from linear concentration dependence (LCD) were observed for the ternary BaxSr1-xTe alloys. The microscopic origins of the gap bowing were explained by using the approach of Zunger and co-workers. On the other hand, the thermodynamic stability of these alloys was investigated by calculating the excess enthalpy of mixing, ΔHm as well as the phase diagram. It was shown that these alloys are stable at high temperature. Thermal effects on some macroscopic properties of BaxSr1-xTe alloys were investigated using the quasi-harmonic Debye model, in which the phononic effects are considered.

  6. Large area thin film CdTe and Zn(x)Cd(1-x)Te heterojunction solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, S. S.; Firszt, F.; Naseem, H. A.; Stawski, R.

    Thin film CdTe heterojunction solar cells have been prepared by the deposition of p-type CdTe films on CdS/SnO2:F/glass substrates using chemical vapor deposition (CVD) and close-spaced sublimation (CSS) techniques. The relative merits of the two techniques are discussed, and the characteristics of solar cells prepared by CVD and CSS techniques are compared. In addition, the properties of Zn(x)Cd(1-x)Te have been investigated.

  7. XMM-Newton observations of the black hole X-ray transient XTE J1650-500 in quiescence

    CERN Document Server

    Homan, J; Kong, A; Miller, J M; Rossi, S; Belloni, T; Lewin, W H G; Homan, Jeroen; Wijnands, Rudy; Kong, Albert; Miller, Jon M.; Rossi, Sabrina; Belloni, Tomaso; Lewin, Walter H.G.

    2006-01-01

    We report the result of an XMM-Newton observation of the black-hole X-ray transient XTE J1650-500 in quiescence. The source was not detected and we set upper limits on the 0.5-10 keV luminosity of 0.9e31-1.0e31 erg/s (for a newly derived distance of 2.6 kpc). These limits are in line with the quiescent luminosities of black-hole X-ray binaries with similar orbital periods (~7-8 hr)

  8. Cd{sub 1−x}Mn{sub x}Te ultrasmall quantum dots growth in a silicate glass matrix by the fusion method

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Noelio Oliveira; Lima Fernandes, Guilherme de; Almeida Silva, Anielle Christine [Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberlândia, 38408-100 Uberlândia, MG (Brazil); Baffa, Oswaldo; Gómez, Jorge Antônio [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP (Brazil)

    2014-09-29

    In this study, we synthesized Cd{sub 1−x}Mn{sub x}Te ultrasmall quantum dots (USQDs) in SiO{sub 2}-Na{sub 2}CO{sub 3}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass system using the fusion method. Growth of these Cd{sub 1−x}Mn{sub x}Te USQDs was confirmed by optical absorption, atomic force microscopy (AFM), magnetic force microscopy (MFM), scanning transmission electron microscopy (TEM), and electron paramagnetic resonance (EPR) measurements. The blueshift of absorption transition with increasing manganese concentration gives evidence of incorporation of manganese ions (Mn{sup 2+}) in CdTe USQDs. AFM, TEM, and MFM confirmed, respectively, the formation of high quality Cd{sub 1−x}Mn{sub x}Te USQDs with uniformly distributed size and magnetic phases. Furthermore, EPR spectra showed six lines associated to the S = 5/2 spin half-filled d-state, characteristic of Mn{sup 2+}, and confirmed that Mn{sup 2+} are located in the sites core and surface of the CdTe USQD. Therefore, synthesis of high quality Cd{sub 1−x}Mn{sub x}Te USQDs may allow the control of optical and magnetic properties.

  9. Topological crystalline insulator PbxSn1-xTe thin films on SrTiO3 (001 with tunable Fermi levels

    Directory of Open Access Journals (Sweden)

    Hua Guo

    2014-05-01

    Full Text Available In this letter, we report a systematic study of topological crystalline insulator PbxSn1-xTe (0 < x < 1 thin films grown by molecular beam epitaxy on SrTiO3(001. Two domains of PbxSn1-xTe thin films with intersecting angle of α ≈ 45° were confirmed by reflection high energy diffraction, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy (ARPES. ARPES study of PbxSn1-xTe thin films demonstrated that the Fermi level of PbTe could be tuned by altering the temperature of substrate whereas SnTe cannot. An M-shaped valance band structure was observed only in SnTe but PbTe is in a topological trivial state with a large gap. In addition, co-evaporation of SnTe and PbTe results in an equivalent variation of Pb concentration as well as the Fermi level of PbxSn1-xTe thin films.

  10. Evidence for a compact jet dominating the broad-band spectrum of the black hole accretor XTE J1550-564

    NARCIS (Netherlands)

    Russell, D.M.; Maitra, D.; Dunn, R.J.H.; Markoff, S.

    2010-01-01

    The black hole X-ray binary XTE J1550-564 was monitored extensively at X-ray, optical and infrared wavelengths throughout its outburst in 2000. We show that it is possible to separate the optical/near-infrared (OIR) jet emission from the OIR disc emission. Focussing on the jet component, we find tha

  11. Searches for continuous gravitational waves from Scorpius X-1 and XTE J1751-305 in LIGO's sixth science run

    CERN Document Server

    Meadors, Grant David; Riles, Keith; Creighton, Teviet; Robinet, Florent

    2016-01-01

    Scorpius X-1 (Sco X-1) and X-ray transient (XTE) J1751-305 are Low-Mass X-ray Binaries (LMXBs) that may emit continuous gravitational waves detectable in the band of ground-based interferometric observatories. Neutron stars in LMXBs could reach a torque-balance steady-state equilibrium in which angular momentum addition from infalling matter from the binary companion is balanced by angular momentum loss, conceivably due to gravitational-wave emission. Torque-balance predicts a scale for detectable gravitational-wave strain based on observed X-ray flux. This paper describes a search for Sco X-1 and XTE J1751-305 in LIGO Science Run 6 data using the TwoSpect algorithm, based on searching for orbital modulations in the frequency domain. While no detections are claimed, the most stringent upper limits to date on continuous gravitational-wave emission from Sco X-1 are obtained, spanning gravitational wave frequencies from 40 to 2040 Hz and projected semi-major axes from 0.90 to 1.98 light-seconds. At optimal strai...

  12. The Variable Quiescent X-Ray Emission of the Neutron Star Transient XTE J1701-462

    CERN Document Server

    Fridriksson, Joel K; Wijnands, Rudy; Cackett, Edward M; Altamirano, Diego; Brown, Edward F; Degenaar, Nathalie; Mendez, Mariano; Belloni, Tomaso M

    2011-01-01

    We present the results of continued monitoring of the quiescent neutron star low-mass X-ray binary XTE J1701-462 with Chandra and Swift. A new Chandra observation from 2010 October extends our tracking of the neutron star surface temperature from ~800 days to ~1160 days since the end of an exceptionally luminous 19 month outburst. This observation indicates that the neutron star crust may still be slowly cooling toward thermal equilibrium with the core; another observation further into quiescence is needed to verify this. The shape of the cooling curve is consistent with that of a broken power law, although an exponential decay to a constant level cannot be excluded with the present data. To investigate possible low-level activity we conducted a monitoring campaign of XTE J1701-462 with Swift during 2010 April-October. Short-term flares - presumably arising from episodic low-level accretion - were observed up to a luminosity of ~1e35 erg/s, ~20 times higher than the normal quiescent level. We conclude that fl...

  13. The Low Quiescent X-Ray Luminosity of the Neutron Star Transient XTE J2123-058

    CERN Document Server

    Tomsick, J A; Halpern, J P; Kaaret, Philip

    2004-01-01

    We report on the first X-ray observations of the neutron star soft X-ray transient (SXT) XTE J2123-058 in quiescence, made by Chandra and BeppoSAX, as well as contemporaneous optical observations. In 2002, the Chandra spectrum of XTE J2123-058 is consistent with a power-law model, or the combination of a blackbody plus a power-law, but it is not well-described by a pure blackbody. Using the interstellar column density, the power-law fit gives photon index of 3.1 (+0.7,-0.6) and indicates a 0.3-8 keV unabsorbed luminosity of 9(+4,-3)E31 (d/8.5 kpc)^2 ergs/s (90% confidence errors). Fits with models consisting of thermal plus power-law components indicate that the upper limit on the temperature of a 1.4 solar mass, 10 km radius neutron star with a hydrogen atmosphere is kT_eff ~ 70 years.

  14. Prediction of an arc-tunable Weyl Fermion metallic state in MoxW1-xTe2

    Science.gov (United States)

    Chang, Tay-Rong; Xu, Su-Yang; Chang, Guoqing; Lee, Chi-Cheng; Huang, Shin-Ming; Wang, Baokai; Bian, Guang; Zheng, Hao; Sanchez, Daniel S.; Belopolski, Ilya; Alidoust, Nasser; Neupane, Madhab; Bansil, Arun; Jeng, Horng-Tay; Lin, Hsin; Zahid Hasan, M.

    2016-02-01

    A Weyl semimetal is a new state of matter that hosts Weyl fermions as emergent quasiparticles. The Weyl fermions correspond to isolated points of bulk band degeneracy, Weyl nodes, which are connected only through the crystal's boundary by exotic Fermi arcs. The length of the Fermi arc gives a measure of the topological strength, because the only way to destroy the Weyl nodes is to annihilate them in pairs in the reciprocal space. To date, Weyl semimetals are only realized in the TaAs class. Here, we propose a tunable Weyl state in MoxW1-xTe2 where Weyl nodes are formed by touching points between metallic pockets. We show that the Fermi arc length can be changed as a function of Mo concentration, thus tuning the topological strength. Our results provide an experimentally feasible route to realizing Weyl physics in the layered compound MoxW1-xTe2, where non-saturating magneto-resistance and pressure-driven superconductivity have been observed.

  15. Detection of a large Be circumstellar disk during X-ray quiescence of XTE J1946+274

    CERN Document Server

    Arabaci, M Ozbey; Gutierrez-Soto, J; Zurita, C; Nespoli, E; Suso, J; Kiaeerad, F; Garcia-Rojas, J; Kiziloglu, U

    2014-01-01

    We present a multiwavelength study of the Be/X-ray binary system XTE J1946+274 with the main goal of better characterizing its behavior during X-ray quiescence. We aim to shed light on the mechanism which triggers the X-ray activity for this source. XTE J1946+274 was observed by Chandra-ACIS during quiescence in 2013 March 12. In addition, this source has been monitored from the ground-based astronomical observatories of El Teide (Tenerife, Spain), Roque de los Muchachos (La Palma, Spain) and Sierra Nevada (Granada, Spain) since 2011 September, and from the TUBITAK National Observatory (Antalya, Turkey) since 2005 April. We have performed spectral and photometric temporal analyses in order to investigate the quiescent state and transient behavior of this binary system. In 2006, a long mass ejection event took place from the Be star, lasting for about seven years. We also found that a large Be circumstellar disk was present during quiescence, although major X-ray activity was not observed. We made an attempt t...

  16. Emission geometry, radiation pattern, and magnetic topology of the magnetar XTE J1810-197 in its quiescent state

    CERN Document Server

    Bernardini, Federico; Gotthelf, Eric; Israel, Gian Luca; Rea, Nanda; Stella, Luigi

    2011-01-01

    The return to the quiescent state of the Anomalous X-ray pulsar XTE J1810-197 following its 2003 outburst represents a unique opportunity to probe the surface emission properties of a magnetar. The quiescent emission of XTE J1810-197 is composed of two thermal components, one arising from the whole star surface, and the other from a small warm spot on it. By modeling the magnitude and shape of the pulse profile in narrow spectral bands, we have been able to constrain the physical characteristics and geometrical parameters of the system: the two angles that the line of sight and the spin axis make with respect to the warm spot axis (\\psi\\ and \\xi\\ respectively), the angular size of the spot, and the overall surface temperature distribution. Our modeling accounts for the general relativistic effects of gravitational redshift and light bending near the stellar surface, and allows for local anisotropic emission. We found that the surface temperature distribution on the neutron star is consistent with the expectat...

  17. Characterizing Intermittency of 4-Hz Quasi-periodic Oscillation in XTE J1550-564 using Hilbert-Huang Transform

    CERN Document Server

    Su, Yi-Hao; Hu, Chin-Ping; Yang, Ting-Chang

    2015-01-01

    We present the time-frequency analysis results based on the Hilbert-Huang transform (HHT) for the evolution of a 4-Hz low-frequency quasi-periodic oscillation (LFQPO) around the black hole X-ray binary XTE J1550-564. The origin of LFQPOs is still debated. To understand the cause of the peak broadening, we utilized a recently developed time-frequency analysis, HHT, for tracking the evolution of the 4-Hz LFQPO from XTE J1550 564. By adaptively decomposing the ~4-Hz oscillatory component from the light curve and acquiring its instantaneous frequency, the Hilbert spectrum illustrates that the LFQPO is composed of a series of intermittent oscillations appearing occasionally between 3 Hz and 5 Hz. We further characterized this intermittency by computing the confidence limits of the instantaneous amplitudes of the intermittent oscillations, and constructed both the distributions of the QPO's high and low amplitude durations, which are the time intervals with and without significant ~4-Hz oscillations, respectively. ...

  18. A Chandra observation of the accretion-driven millisecond X-ray pulsar XTE J0929-314 in quiescence

    CERN Document Server

    Wijnands, R; Heinke, C O; Miller, J M; Lewin, W H G; Wijnands, Rudy; Homan, Jeroen; Heinke, Craig O.; Miller, Jon M.; Lewin, Walter H. G.

    2004-01-01

    We observed the accretion-driven millisecond X-ray pulsar XTE J0929-314 in its quiescent state using Chandra. XTE J0929-314 is the second such source to be observed in quiescence, after SAX J1808.4-3658. We detected 22 source photons (in the energy range 0.3-8 keV) in ~24.4 ksec, resulting in a background-corrected count rate of 9+/-2 x 10^{-4} counts s^{-1}. This small number of photons detected did not allow for a detailed spectral analysis of the quiescent spectrum, but we can demonstrate that the spectrum is harder than simple thermal emission which is usually presumed to arise from a cooling neutron star that has been heated during the outbursts. Assuming a power-law model for the X-ray spectrum, we obtain a power-law index of 2.2+/-0.6 and an unabsorbed X-ray flux of 6.5^{+2.8}_{-2.1} x 10^{-15} ergs s^{-1} cm^{-2} (for the energy range 0.5-10 keV), resulting in a 0.5-10 keV X-ray luminosity of 8+/-3 x 10^{31} (d/10 kpc)^2 ergs s^{-1}, with d the distance toward the source in kpc. No thermal component c...

  19. Implications of an r-mode in XTE J1751-305: Mass, radius and spin evolution

    CERN Document Server

    Andersson, N; Ho, W C G

    2014-01-01

    Recently Strohmayer and Mahmoodifar presented evidence for a coherent oscillation in the X-ray light curve of the accreting millisecond pulsar XTE J1751-305, using data taken by RXTE during the 2002 outburst of this source. They noted that a possible explanation includes the excitation of a non-radial oscillation mode of the neutron star, either in the form of a g-mode or an r-mode. The r-mode interpretation has connections with proposed spin-evolution scenarios for systems such as XTE J1751-305. Here we examine in detail this interesting possible interpretation. Using the ratio of the observed oscillation frequency to the star's spin frequency, we derive an approximate neutron star mass-radius relation which yields reasonable values for the mass over the range of expected stellar radius (as constrained by observations of radius-expansion burst sources). However, we argue that the large mode amplitude suggested by the Strohmayer and Mahmoodifar analysis would inevitably lead to a large spin-down of the star, ...

  20. Outbursts and State Transitions in Black Hole Candidates observed by MAXI

    Science.gov (United States)

    Negoro, H.; Maxi Team

    2010-12-01

    MAXI continuously observes several black hole candidates in our Galaxy and LMC. MAXI already detected various state transitions in Cyg X-1, GX 339-4, Swift J1752.5-127, and black hole transients, H 1743-332, 4U 1630, XTE J1752-223, and MAXI J1659-125. From these observations, we try to clarify what happens during the transitions, and what triggers the transitions. In any case, fast alerts just before the transitions and soon after the outbursts are crucial to detect, for instance, radio and high energy gamma-ray jets or emission. We also present some successful examples of alerts from our MAXI transient alert system.

  1. X-ray diffuse scattering study of local distortions in Fe1+xTe induced by excess Fe

    Science.gov (United States)

    Liu, X.; Lee, C.-C.; Xu, Z. J.; Wen, J. S.; Gu, G.; Ku, W.; Tranquada, J. M.; Hill, J. P.

    2011-05-01

    We report x-ray diffuse scattering studies of the iron chalcogenide Fe1+xTe as a function of doping and temperature for x=0.03, 0.08, and 0.12. In all cases, remarkably strong, characteristic diffuse scattering is observed. This scattering extends throughout the Brillouin zone and exhibits a nonmonotonic decay away from the fundamental Bragg peaks, with a peaklike structure at a reduced q≈(0.3,0,0.6). We interpret this scattering as Huang diffuse scattering resulting from distortions induced by the interaction between the excess Fe and the FeTe layers. The form of the scattering indicates that this interaction is strong and extends a number of unit cells away from the interstitial Fe site. Further, the diffuse scattering shows a sudden decrease on cooling through the structural and magnetic phase transition, reflecting the first-order change of the electronic structure of FeTe.

  2. X-ray Diffuse Scattering Study of Local Distortions in Fe1+xTe Induced by Excess Fe

    Energy Technology Data Exchange (ETDEWEB)

    Hill, J.P.; Liu, X.; Lee, C.-C.; Xu, Z.J.; Wen, J.S.; Gu, G.; Ku, W.; Tranquada, J.M.

    2011-05-01

    We report x-ray diffuse scattering studies of the iron chalcogenide Fe{sub 1+x}Te as a function of doping and temperature for x = 0.03, 0.08, and 0.12. In all cases, remarkably strong, characteristic diffuse scattering is observed. This scattering extends throughout the Brillouin zone and exhibits a nonmonotonic decay away from the fundamental Bragg peaks, with a peaklike structure at a reduced q {approx} (0.3,0,0.6). We interpret this scattering as Huang diffuse scattering resulting from distortions induced by the interaction between the excess Fe and the FeTe layers. The form of the scattering indicates that this interaction is strong and extends a number of unit cells away from the interstitial Fe site. Further, the diffuse scattering shows a sudden decrease on cooling through the structural and magnetic phase transition, reflecting the first-order change of the electronic structure of FeTe.

  3. Quasi-periodic oscillations discovered in the new X-ray pulsar XTE J1858+034

    CERN Document Server

    Paul, B

    1998-01-01

    We report the discovery of low frequency quasi-periodic oscillations centered at 0.11 Hz in the newly discovered 221 s X-ray pulsar XTE J1858+034. Among about 30 known transient X-ray pulsars this is the sixth source in which QPOs have been observed. If the QPOs are produced because of inhomogeneities in the accretion disk at the magnetospheric boundary, the low frequency of the QPOs indicate a large magnetosphere for this pulsar. Both the Keplerian frequency model and the beat frequency model are applicable for production of QPOs in this source. The QPOs and regular pulsations are found to be stronger at higher energy which favours the beat frequency model. The magnetic field of the pulsar is calculated as a function of its distance. The energy spectrum is found to be very hard, consisting of two components, a cut-off power law and an iron fluorescence line.

  4. High frequency quasi-periodic oscillations in the black hole X-ray transient XTE J1650-500

    CERN Document Server

    Homan, J; Rossi, S; Miller, J M; Wijnands, R; Belloni, T; Van der Klis, M; Lewin, W H G; Homan, Jeroen; Klein-Wolt, Marc; Rossi, Sabrina; Miller, Jon M.; Wijnands, Rudy; Belloni, Tomaso; Klis, Michiel van der; Lewin, Walter H. G.

    2003-01-01

    We report the detection of high frequency variability in the black hole X-ray transient XTE J1650-500. A quasi-periodic oscillation (QPO) was found at 250 Hz during a transition from the hard to the soft state. We also detected less coherent variability around 50 Hz, that disappeared when the 250 Hz QPO showed up. There are indications that when the energy spectrum hardened the QPO frequency increased from ~110 Hz to ~270 Hz, although the observed frequencies are also consistent with being 1:2:3 harmonics of each other. Interpreting the 250 Hz as the orbital frequency at the innermost stable orbit around a Schwarzschild black hole leads to a mass estimate of 8.2 Msun. The spectral results by Miller et al.(2002, ApJ, 570, L69), which suggest considerable black hole spin, would imply a higher mass.

  5. The Variable Quiescent X-Ray Emission of the Neutron Star Transient XTE J1701-462

    Science.gov (United States)

    Fridriksson, Joel K.; Homan, J.; Wijnands, R.; Cackett, E. M.; Degenaar, N.; Mendez, M.; Altamirano, D.; Brown, E. F.; Belloni, T. M.; Lewin, W. H. G.

    2011-01-01

    We have monitored the cooling of the neutron star in the transient low-mass X-ray binary XTE J1701-462 with Chandra and XMM-Newton since the source entered quiescence in 2007 after an exceptionally luminous 19-month outburst. A recent Chandra observation made almost 1200 days into quiescence indicates that the neutron star crust is likely still slowly cooling toward thermal equilibrium with the core. The current surface temperature is high compared to other quiescent neutron star transients, with an implied bolometric thermal flux of 5×1033 erg/s. The overall cooling curve seems to have followed a broken power-law shape as predicted by theoretical models, although the observed break is considerably earlier than what is expected from theory. After rapid cooling during the first 200 days of quiescence---strongly indicating a highly conductive neutron star crust---the source unexpectedly showed a large temporary increase in both thermal and non-thermal flux. Prompted by this we conducted a Swift monitoring program of the source during April-October 2010, with short observations taking place once every two weeks. During the program we detected short-term flares up to at least 1×1035 erg/s, a factor of 20 higher than the normal quiescent level. We compare this flaring---presumably arising from episodic low-level accretion---with the behavior observed from faint Galactic transients, and discuss whether flaring in XTE J1701-462 can significantly affect the cooling of the source and whether it can to some extent explain the high temperature of the neutron star core implied by our Chandra observations.

  6. Computer optimization of multispectral solar cells based on GaAs Hg{sub 1-x}Cd{sub x}Te

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, D.; Esteve, D. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France); Rouhani, D. [Toulouse-3 Univ., 31 (France); Sylla, A.; Kouadja, K. [Abidjan Univ. (Cote d`Ivoire)

    1995-12-31

    The performances of the monolithic two solar cells tandem is studied. The geometrical and physical parameters of the two cells connected in series are determined for the optimal operation of the device. The chemical composition of the infra red sensitive Hg{sub 1-x}Cd{sub x}Te solar cell is for x = 0.53 with an energy gap of 0.6 eV. The maximum efficiency of the tandem under AM1 solar radiation has been found to be 30 % with contributions of 25 % and 5% for the GaAs and Hg{sub 1-w}Cd{sub x}Te solar cells, respectively. However, sophisticated technologies are needed to achieve this efficiency. (author) 12 refs.

  7. Stimulated emission of free excitons in Cd{sub 1-x}Mn{sub x}Te under nonresonant two-photon excitation

    Energy Technology Data Exchange (ETDEWEB)

    Jang, J.I. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)], E-mail: joon-jang@northwestern.edu; Mani, S.; Ketterson, J.B. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Park, H.Y. [Department of Semiconductor Applications, Ulsan College, San 29 Mugeo Dong, Ulsan 680-749 (Korea, Republic of)], E-mail: hypark@mail.uc.ac.kr

    2008-08-25

    We report on free excitons coexisting with exciton magnetic polarons (EMPs) in bulk semimagnetic semiconductors of Cd{sub 1-x}Mn{sub x}Te for 0.04{<=}x{<=}0.36 at 2 K under nonresonant two-photon excitation. This two-photon excitation not only generates free excitons but also more efficiently creates EMPs compared with ordinary one-photon excitation. Stimulated emission from free excitons is demonstrated under strong two-photon excitation.

  8. The SMC X-ray transient XTE J0111.2-7317 a Be/X-ray binary in a SNR?

    CERN Document Server

    Coe, M J; Reig, P

    1999-01-01

    We report observations which confirm the identity of the optical/IR counterpart to the Rossi X-ray Timing Explorer transient source XTE J0111.2-7317. The counterpart is suggested to be a B0-B2 star (luminosity class III--V) showing an IR excess and strong Balmer emission lines. The distance derived from reddening and systemic velocity measurements puts the source in the SMC. Unusually, the source exhibits an extended asymetric H alpha structure.

  9. Discovery of twin kHz quasi periodic oscillations in the low mass X-ray binary XTE J1701-407

    CERN Document Server

    Pawar, Devraj D; Altamirano, Diego; Linares, Manuel; Shanthi, K; Strohmayer, Tod; Bhattacharya, Dipankar; van der Klis, Michiel

    2013-01-01

    We report the discovery of kHz quasi periodic oscillations (QPOs) in three Rossi X-ray Timing Explorer observations of the low mass X-ray binary (LMXB) XTE J1701-407. In one of the observations we detect a kHz QPO with a characteristic frequency of 1153 +/- 5 Hz, while in the other two observations we detect twin QPOs at characteristic frequencies of 740 +/- 5 Hz, 1112 +/- 17 Hz and 740 +/- 11 Hz, 1098 +/- 5 Hz. All detections happen when XTE J1701-407 was in its high intensity soft state, and their single trial significance are in the 3.1-7.5 sigma range. The frequency difference in the centroid frequencies of the twin kHz QPOs (385 +/- 13 Hz) is one of the largest seen till date. The 3-30 keV fractional rms amplitude of the upper kHz QPO varies between ~18 % and ~30 %. XTE J1701-407, with a persistent luminosity close to 1 % of the Eddington limit, is among the small group of low luminosity kHz QPO sources and has the highest rms for the upper kHz QPO detected in any source. The X-ray spectral and variabili...

  10. The kilohertz quasi-periodic oscillations during the Z and atoll phases of the unique transient XTE J1701--462

    CERN Document Server

    Sanna, A; Altamirano, D; Homan, J; Casella, P; Belloni, T; Lin, D; van der Klis, M; Wijnands, R

    2010-01-01

    We analysed 866 observations of the neutron-star low-mass X-ray binary XTE J1701-462 during its 2006-2007 outburst. XTE J1701-462 is the only example so far of a source that during an outburst showed, beyond any doubt, spectral and timing characteristics both of the Z and atoll type. We found that the lower kHz QPO in the atoll phase has a significantly higher coherence and fractional rms amplitude than any of the kHz QPOs seen during the Z phase, and that in the same frequency range, atoll lower kHz QPOs show coherence and fractional rms amplitude, respectively, 2 and 3 times larger than the Z kHz QPOs. Out of the 707 observations in the Z phase, there is no single observation in which the kHz QPOs have a coherence or rms amplitude similar to those seen when XTE J1701-462 was in the atoll phase, even though the total exposure time was about 5 times longer in the Z than in the atoll phase. Since it is observed in the same source, the difference in QPO coherence and rms amplitude between the Z and atoll phase ...

  11. Observations of the optical counterpart to XTE J1118+480 during outburst by the robotic optical transient search experiment In telescope

    CERN Document Server

    Wren, J; Balsano, R; Bloch, J; Borozdin, K N; Casperson, D E; Gisler, G; Kehoe, R; Lee Byung Cheol; Marshall, S; McKay, T; Priedhorsky, W; Rykoff, E S; Smith, D; Trudolyubov, S P; Vestrand, W T

    2001-01-01

    The X-ray nova XTE J1118+480 exhibited two outbursts in the early part of 2000. As detected by the Rossi X-ray Timing Explorer (RXTE), the first outburst began in early January and the second began in early March. Routine imaging of the northern sky by the Robotic Optical Transient Search Experiment (ROTSE) shows the optical counterpart to XTE J1118+480 during both outbursts. These data include over 60 epochs from January to June 2000. A search of the ROTSE data archives reveal no previous optical outbursts of this source in selected data between April 1998 and January 2000. While the X-ray to optical flux ratio of XTE J1118+480 was low during both outbursts, we suggest that they were full X-ray novae and not mini-outbursts based on comparison with similar sources. The ROTSE measurements taken during the March 2000 outburst also indicate a rapid rise in the optical flux that preceded the X-ray emission measured by the RXTE by approximately 10 days. Using these results, we estimate a pre-outburst accretion dis...

  12. XMM-Newton Spectroscopy of the Accretion-Driven Millisecond X-ray Pulsar XTE J1751-305 in Outburst

    CERN Document Server

    Miller, J M; Méndez, M; Kendziorra, E; Tiengo, A; Van der Klis, M; Chakraborty, D; Gaensler, B M; Lewin, W H G

    2003-01-01

    We present an analysis of the first high-resolution spectra measured from an accretion-driven millisecond X-ray pulsar in outburst. We observed XTE J1751-305 with XMM-Newton on 2002 April 7 for approximately 35 ks. Using a simple absorbed blackbody plus power-law model, we measure an unabsorbed flux of (6.6 +/- 0.1) * 10^(-10) erg/cm^(2)/s (0.5-10.0 keV). A hard power-law component (Gamma = 1.44 +/- 0.01) contributes 83% of the unabsorbed flux in the 0.5-10.0 keV band, but a blackbody component (kT = 1.05 +/- 0.01 keV) is required. We find no clear evidence for narrow or broad emission or absorption lines in the time-averaged spectra, and the sensitivity of this observation has allowed us to set constraining upper-limits on the strength of important features. The lack of line features is at odds with spectra measured from some other X-ray binaries which share some similarities with XTE J1751-305. We discuss the implications of these findings on the accretion flow geometry in XTE J1751-305 and the geometries i...

  13. Photovoltaic performances of Cu2-xTe sensitizer based on undoped and indium(3+)-doped TiO2 photoelectrodes and assembled counter electrodes.

    Science.gov (United States)

    Srathongluan, Pornpimol; Kuhamaneechot, Rattanakorn; Sukthao, Prapatsawan; Vailikhit, Veeramol; Choopun, Supab; Tubtimtae, Auttasit

    2016-02-01

    Novel binary Cu2-xTe nanoparticles based on undoped and indium-doped TiO2 photoelectrodes were synthesized using a successive ionic layer adsorption and reaction (SILAR) technique as a sensitizer for liquid-junction solar cells. A larger diameter of TiO2 promoted a narrower energy band gap after indium doping, attributing to yield a broader absorption range of nanoparticle sensitizer due to the increasing amount of Cu2-xTe NPs on TiO2 surface. The atomic percentages showed the stoichiometric formation of Cu2Te incorporated in a Cu2-xTe structure. The best photovoltaic performance with the lower SILAR cycle, i.e., n=13 was performed after indium doping in both of carbon and Cu2S CEs and revealed that the efficiency of 0.73% under the radiant 100mW/cm(2) (AM 1.5G). The electrochemical impedance spectroscopy (EIS) was used to investigate the electrical properties via effect of material doping and counter electrodes with a lower charge-transfer resistance (Rct) and it was also found that the electron lifetime was improved after the sample doped with indium and assembled with carbon CE.

  14. Independent candidates in Mexico

    OpenAIRE

    Campos, Gonzalo Santiago

    2014-01-01

    In this paper we discuss the issue of independent candidates in Mexico, because through the so-called political reform of 2012 was incorporated in the Political Constitution of the Mexican United States the right of citizens to be registered as independent candidates. Also, in September 2013 was carried out a reform of Article 116 of the Political Constitution of the Mexican United States in order to allow independent candidates in each state of the Republic. However, prior to the constitutio...

  15. External Compton emission from relativistic jets in Galactic black hole candidates and ultraluminous X-ray sources

    CERN Document Server

    Georganopoulos, M; Kirk, J G

    2002-01-01

    Galactic binary systems that contain a black hole candidate emit hard X-rays in their low luminosity mode. We show that this emission can be understood as due to the Compton scattering of photons from the companion star and/or the accretion disk by relativistic electrons in a jet. The same electrons are also responsible for the radio emission. Two sources -- XTE J1118+480 and Cygnus X-1 -- are modelled as representatives of black holes with low and high luminosity companion stars respectively. We further show that the ultraluminous compact X-ray sources observed in nearby galaxies have the properties expected of stellar mass black holes with high luminosity companions in which the jet is oriented close to our line of sight.

  16. Results of INTEGRAL TOO observation of the transient X-ray burster XTE J1810-189

    CERN Document Server

    Chelovekov, I

    2010-01-01

    We report results of the INTEGRAL Target of Opportunity observations of the transient X-ray burster XTE J1810-189. The observations were performed on April 3--6, 2008, soon after the discovery of the source and near the peak of its outburst. That time the source had a flux of about 50 mCrab and exhibited a hard Comptonized X-ray spectrum extending well above 100 keV. Being approximated by a power law with an exponetial cut-off in the broad 3--100 keV energy band it gave the average photon index $\\Gamma\\simeq 1.6$ and $kT_{cutoff}\\simeq 67$ keV. We found only slight indications for changes in the index during the observation ($\\Gamma$ first steady decreased from $\\sim 2.0$ to $\\sim1.3$ and then increased back to $\\sim 2.0$). However the $N_{\\rmn H}$ value measured by absorption in the low energy part of the spectrum changed drastically and very irregularly (from $\\sim 4\\times 10^{22}$ till $\\sim 100\\times 10^{22}$ cm$^{-2}$). There were 10 type I X-ray bursts detected from the source during these TOO observati...

  17. An XMM-Newton view of the dipping low-mass X-ray binary XTE J1710-281

    CERN Document Server

    Younes, G; Sabra, B

    2009-01-01

    (abridged) We analyzed the archived XMM-Newton observation of the poorly studied low-mass X-ray binary XTE J1710-281 performed in 2004 that covered one orbital period of the system (3.8 hr). The source shows dips as well as eclipses, hence it is viewed close to edge-on. We modeled the spectral changes between persistent and dips in the framework of the partial covering model and the ionized absorber approach. The persistent spectrum can be fit by a power law with a photon index of 1.94(+-0.02) affected by absorption from cool material with a hydrogen column density of 0.401(+-0.007)*10^22 cm^-2. The spectral changes from persistent to deep-dipping intervals are consistent with the partial covering of the power-law emission, with the covering fraction increasing from 26% during shallow dipping to 78% during deep dipping. We do not detect any absorption lines from highly ionized species such as FeXXV. The upper-limits we derive on their equivalent width (EW) are not constraining. Despite not detecting any signa...

  18. Long-Term Spectral and Temporal Evolution of Anomalous X-Ray Pulsar XTE J1810-197

    Science.gov (United States)

    Vurgun, Eda; Gogus, Ersin; Chakraborty, Manoneeta; Guver, Tolga

    2016-07-01

    We present spectral and timing studies of the first transient Anomalous X-ray Pulsar XTE J1810-197, a 5.54 s pulsar discovered in 2003, when its X-ray luminosity increased ~100 fold. We investigate the long-term behaviour of the surface temperature,emitting area, and the pulsed fraction. X-ray spectra are well fitted by a two-component blackbody model in which the cool component is most likely arising from the whole surface of star and the hot component is arising from a relatively small hot spot on it. The spectral analysis has also shown evidence for the presence of an absorbtion line feature around 1.2 keV in almost all observations. We fit this absorption feature with an asymmetric gaussian component since it shows an asymmetric structure. The pulse fraction exhibits slightly different temporal evolution in higher and lower energy bands. We will discuss correlative behaviour between the spectral and timing parameters in order to constrain magnetar cooling models.

  19. Variable Quasi Periodic Oscillations during an Outburst of the Transient X-ray Pulsar XTE J1858 + 034

    Indian Academy of Sciences (India)

    U. Mukherjee; S. Bapna; H. Raichur; B. Paul; S. N. A. Jaaffrey

    2006-03-01

    We have investigated the Quasi Periodic Oscillation (QPO) properties of the transient accreting X-ray pulsar XTE J1858 + 034 during the second outburst of this source in April–May 2004. We have used observations made with the Proportional Counter Array (PCA) of the Rossi X-ray Timing Explorer (RXTE) during May 14–18, 2004, in the declining phase of the outburst. We detected the presence of low frequency QPOs in the frequency range of 140–185 mHz in all the RXTE-PCA observations. We report evolution of the QPO parameters with the time, X-ray flux, and X-ray photon energy. Though a correlation between the QPO centroid frequency and the instantaneous X-ray flux is not very clear from the data, we point out that the QPO frequency and the one day averaged X-ray flux decreased with time during these observations. We have obtained a clear energy dependence of the RMS variation in the QPOs, increasing from about 3% at 3 keV to 6% at 25 keV. The X-ray pulse profile is a single peaked sinusoidal, with pulse fraction increasing from 20% at 3 keV to 45% at 30 keV. We found that, similar to the previous outburst, the energy spectrum is well fitted with amodel consisting of a cut-off power law along with an iron emission line.

  20. Studies of orbital parameters and pulse profile of the accreting millisecond pulsar XTE J1807-294

    CERN Document Server

    Kirsch, M G F; Breitfellner, M G; Djavidnia, S; Freyberg, M J; Kendziorra, E; Smith, M J S

    2004-01-01

    The accreting millisecond pulsar XTE J1807-294 was observed by XMM-Newton on March 22, 2003 after its discovery on February 21, 2003 by RXTE. The source was detected in its bright phase with an observed average count rate of 33.3 cts/s in the EPIC-pn camera in the 0.5-10 keV energy band (3.7 mCrab). Using the earlier established best-fit orbital period of 40.0741+/-0.0005 minutes from RXTE observations and considering a circular binary orbit as first approximation, we derived a value of 4.8+/-0.1 lt-ms for the projected orbital radius of the binary system and an epoch of the orbital phase of MJD 52720.67415(16). The barycentric mean spin period of the pulsar was derived as 5.2459427+/-0.0000004 ms. The pulsar's spin-pulse profile showed a prominent (1.5 ms FWHM) pulse, with energy and orbital phase dependence in the amplitude and shape. The measured pulsed fraction in four energy bands was found to be 3.1+/-0.2 % (0.5-3.0 keV), 5.4+/-0.4 % (3.0-6.0 keV), 5.1+/-0.7 % (6.0-10.0 keV) and 3.7+/-0.2 % (0.5-10.0 ke...

  1. An optical study of vacuum evaporated Se 85-xTe 15Bi x chalcogenide thin films

    Science.gov (United States)

    Ambika; Barman, P. B.

    2010-02-01

    Thin films of Se 85-xTe 15Bi x ( x=0, 1, 2, 3, 4, 5) glassy alloys prepared by melt quenching technique, are deposited on glass substrate using thermal evaporation technique under vacuum. The analysis of transmission spectra, measured at normal incidence, in the spectral range 400-1500 nm helphelps us in the optical characterization of thin films under study. Well -known Swanepoel's method is employed to determine the refractive index ( n) and film thickness ( d). The increase in n with increasing Bi content over the entire spectral range is related to the increased polarizability of the larger Bi atom (atomic radius 1.46 Å) compared with the Se atom (atomic radius 1.16 Å). Dispersion energy ( E d), average energy gap ( E0) and static refractive index ( n0) isare calculated using Wemple-DiDomenico model (WDD). The value of absorption coefficient ( α) and hence extinction coefficient ( k) hashave been determined from transmission spectra. Optical band gap ( E g) is estimated using Tauc's extrapolation and is found to decrease from 1.46 to 1.24 eV with the Bi addition. This behavior of optical band gap is interpreted in terms of electronegativity difference of the atoms involved and cohesive energy of the system.

  2. Multiwavelength observations of the black hole transient XTE J1752-223 during its 2010 outburst decay

    CERN Document Server

    Chun, Y Y; Kalemci, E; Güver, T; Tomsick, J A; Buxton, M M; Brocksopp, C; Corbel, S; Cabrera-Lavers, A

    2013-01-01

    Galactic black hole transients show many interesting phenomena during outburst decays. We present simultaneous X-ray (\\emph{RXTE}, \\emph{Swift}, and \\emph{INTEGRAL}), and optical/near-infrared (O/NIR) observations (SMARTS) of the X-ray transient XTE J1752$-$223 during its outburst decay in 2010. The multiwavelength observations over 150 days in 2010 cover the transition from soft to hard spectral state. We discuss the evolution of radio emission is with respect to the O/NIR light curve which shows several flares. One of those flares is bright and long, starting about 60 days after the transition in X-ray timing properties. During this flare, the radio spectral index becomes harder. Other smaller flares occur along with the X-ray timing transition, and also right after the detection of the radio core. We discuss the significances of these flares. Furthermore, using the simultaneous broadband X-ray spectra including \\emph{INTEGRAL}, we find that a high energy cut-off with a folding energy near 250 keV is necess...

  3. Multiwavelength Observations of the Black Hole Transient XTE J1752-223 during Its 2010 Outburst Decay

    Science.gov (United States)

    Chun, Y. Y.; Dinçer, T.; Kalemci, E.; Güver, T.; Tomsick, J. A.; Buxton, M. M.; Brocksopp, C.; Corbel, S.; Cabrera-Lavers, A.

    2013-06-01

    Galactic black hole transients show many interesting phenomena during outburst decays. We present simultaneous X-ray (RXTE, Swift, and INTEGRAL), and optical/near-infrared (O/NIR) observations (SMARTS) of the X-ray transient XTE J1752-223 during its outburst decay in 2010. The multiwavelength observations over 150 days in 2010 cover the transition from soft to hard spectral state. We discuss the evolution of radio emission with respect to the O/NIR light curve which shows several flares. One of those flares is bright and long, starting about 60 days after the transition in X-ray timing properties. During this flare, the radio spectral index becomes harder. Other smaller flares occur along with the X-ray timing transition, and also right after the detection of the radio core. We discuss the significances of these flares. Furthermore, using the simultaneous broadband X-ray spectra including INTEGRAL, we find that a high energy cut-off with a folding energy near 250 keV is necessary around the time that the compact jet is forming. The broadband spectrum can be fitted equally well with a Comptonization model. In addition, using photoelectric absorption edges in the XMM-Newton Reflection Grating Spectrometer X-ray spectra and the extinction of red clump giants in the direction of the source, we find a lower limit on the distance of >5 kpc.

  4. The optical counterpart of XTE J0929-314, the third transient millisecond X-ray pulsar

    CERN Document Server

    Giles, A B; Hill, K M; Sanders, E

    2005-01-01

    A blue and variable optical counterpart of the X-ray transient XTE J0929-314 was identified on 2002 May 1. We conducted frequent BVRI broadband photometry on this object using the Mt Canopus 1-m telescope during May and June until it had faded to below 21'st magnitude. Nearly continuous I band CCD photometry on 2002 May 2, 3 and 4 revealed a ~ 10 % sinusoidal modulation at the binary period lasting ~ 6 cycles during the latter half of May 2. The phase indicates that the modulation may be due to a combination of emission by a hot spot on the disc and X-ray heating of the secondary. The emission generally trended bluer with B-I decreasing by 0.6 magnitudes during the observations but there were anomalous changes in colour during the first few days after optical identification when the I band flux decreased slightly while fluxes in other bands increased. Spectral analysis of the BVRI broadband photometry show evidence of a variable excess in the R and I bands. We suggest that this may be due to synchrotron emiss...

  5. Rapid Cooling of the Neutron Star in the Quiescent Super-Eddington Transient XTE J1701-462

    CERN Document Server

    Fridriksson, Joel K; Wijnands, Rudy; Mendez, Mariano; Altamirano, Diego; Cackett, Edward M; Brown, Edward F; Belloni, Tomaso M; Degenaar, Nathalie; Lewin, Walter H G

    2010-01-01

    We present Rossi X-Ray Timing Explorer and Swift observations made during the final three weeks of the 2006-2007 outburst of the super-Eddington neutron star transient XTE J1701-462, as well as Chandra and XMM-Newton observations covering the first ~800 days of the subsequent quiescent phase. The source transitioned quickly from active accretion to quiescence, with the luminosity dropping by over three orders of magnitude in ~13 days. The spectra obtained during quiescence exhibit both a thermal component, presumed to originate in emission from the neutron star surface, and a non-thermal component of uncertain origin, which has shown large and irregular variability. We interpret the observed decay of the inferred effective surface temperature of the neutron star in quiescence as the cooling of the neutron star crust after having been heated and brought out of thermal equilibrium with the core during the outburst. The interpretation of the data is complicated by an apparent temporary increase in temperature ~2...

  6. ULTRACAM observations of the black hole X-ray transient XTE J1118+480 in quiescence

    CERN Document Server

    Shahbaz, T; Marsh, T R; Casares, J; Zurita, C; Charles, P A; Haswell, C A; Hynes, R I

    2005-01-01

    We present high time-resolution multicolour observations of the quiescent soft X-ray transient XTE J1118+480 obtained with ULTRACAM. Superimposed on the double-humped continuum g' and i'-band lightcurves are rapid flare events which typically last a few minutes. The power density spectrum of the lightcurves can be described by a broken power-law model with a break frequency at ~2 mHz or a power-law model plus a broad quasi-periodic oscillation (QPO) at ~2 mHz. In the context of the cellular-automaton we estimate the size of the quiescent advection-dominated flow (ADAF) region to be ~10^4 Schwarzschild radii, similar to that observed in other quiescent black hole X-ray transients, suggesting the same underlying physics. The similarites between the low/hard and quiescent state PDS suggest a similar origin for the optical and X-ray variability, most likely from regions at/near the ADAF.

  7. Colours of black holes: infrared flares from the hot accretion disc in XTE J1550-564

    CERN Document Server

    Poutanen, Juri

    2014-01-01

    Outbursts of the black hole (BH) X-ray binaries are dramatic events occurring in our Galaxy approximately once a year. They are detected by the X-ray telescopes and often monitored at longer wavelengths. We analyse the X-ray and optical/infrared (OIR) light-curves of the BH binary XTE J1550-564 during the 2000 outburst. By using the observed extreme colours as well as the characteristic decay timescales of the OIR and X-ray light-curves, we put strong constraints on the extinction towards the source. We accurately separate the contributions to the OIR flux of the irradiated accretion disc and a non-thermal component. We show that the OIR non-thermal component appears during the X-ray state transitions both during the rising and the decaying part of the outburst at nearly the same X-ray hardness but at luminosities differing by a factor of 3. The line marking the quenching/recovery of the non-thermal component at the X-ray hardness - flux diagram seems to coincide with the "jet line" that marks the presence of...

  8. Evidence of 1122 Hz X-ray burst oscillations from the neutron star X-ray transient XTE J1739-285

    DEFF Research Database (Denmark)

    Kaaret, P.; Prieskorn, Z.; in 't Zand, J.J.M.

    2007-01-01

    We report on millisecond variability from the X-ray transient XTE J1739-285. We detected six X-ray type I bursts and found evidence for oscillations at 1122 +/- 0.3 Hz in the brightest X-ray burst. Taking into consideration the power in the oscillations and the number of trials in the search, the...... ranging from 757 to 862 Hz. Using the brightest burst, we derive an upper limit on the source distance of about 10.6 kpc....

  9. X-ray photoelectron spectroscopy and atomic force microscopy characterization of the effects of etching Zn xCd 1- xTe surfaces

    Science.gov (United States)

    George, M. A.; Azoulay, M.; Jayatirtha, H. N.; Burger, A.; Collins, W. E.; Silberman, E.

    1993-10-01

    X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) was used for the first time to characterize the chemical composition of modified surfaces of Zn xCd 1- xTe single crystals. These surface treatments were selected for their relevance to device preparation procedures. The XPS peaks indicated an increase of the tellurium and a depletion of the cadmium concentrations upon etching in bromine methanol solution. AFM revealed the formation of pronounced Te inclusions. Higher x values correlated with a decrease in residual bromine left on the surface, while cut and polished samples had higher oxide concentrations and increased bromination of the surface than cleaved samples.

  10. Primary and Presidential Candidates

    DEFF Research Database (Denmark)

    Goddard, Joseph

    2012-01-01

    This article looks at primary and presidential candidates in 2008 and 2012. Evidence suggests that voters are less influenced by candidates’ color, gender, or religious observation than previously. Conversely, markers of difference remain salient in the imaginations of pollsters and journalists...

  11. Conduction mechanisms in p-type Pb{sub 1-x}Eu{sub x}Te alloys in the insulator regime

    Energy Technology Data Exchange (ETDEWEB)

    Peres, M. L.; Rubinger, R. M.; Ribeiro, L. H.; Rubinger, C. P. L. [Departamento de Fisica e Quimica, Instituto de Ciencias Exatas, Universidade Federal de Itajuba, Itajuba, PB 50, MG CEP 37500-903 (Brazil); Ribeiro, G. M. [Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, Belo Horizonte, PB 702, MG CEP 30123-970 (Brazil); Chitta, V. A. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, PB 66318, SP CEP 05315-970 (Brazil); Rappl, P. H. O.; Abramof, E. [Laboratorio Associado de Sensores e Materiais, Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, PB 515, SP CEP 12201-970 (Brazil)

    2012-06-15

    Electrical resistivity measurements were performed on p-type Pb{sub 1-x}Eu{sub x}Te films with Eu content x = 4%, 5%, 6%, 8%, and 9%. The well-known metal-insulator transition that occurs around 5% at room temperature due to the introduction of Eu is observed, and we used the differential activation energy method to study the conduction mechanisms present in these samples. In the insulator regime (x > 6%), we found that band conduction is the dominating conduction mechanism for high temperatures with carriers excitation between the valence band and the 4f levels originated from the Eu atoms. We also verified that mix conduction dominates the low temperatures region. Samples with x = 4% and 5% present a temperature dependent metal insulator transition and we found that this dependence can be related to the relation between the thermal energy k{sub B}T and the activation energy {Delta}{epsilon}{sub a}. The physical description obtained through the activation energy analysis gives a new insight about the conduction mechanisms in insulating p-type Pb{sub 1-x}Eu{sub x}Te films and also shed some light over the influence of the 4f levels on the transport process in the insulator region.

  12. Strongly absorbed quiescent X-ray emission from the X-ray transient XTE J0421+56 (CI Cam) observed with XMM-Newton

    CERN Document Server

    Boirin, L; Oosterbroek, T; Lumb, D H; Orlandini, M; Schartel, N

    2002-01-01

    We have observed the X-ray transient XTE J0421+56 in quiescence with XMM-Newton. The observed spectrum is highly unusual being dominated by an emission feature at ~6.5 keV. The spectrum can be fit using a partially covered power-law and Gaussian line model, in which the emission is almost completely covered (covering fraction of 0.98_{-0.06}^{+0.02}) by neutral material and is strongly absorbed with an N_H of (5_{-2}^{+3}) x 10^{23} atom cm^{-2}. This absorption is local and not interstellar. The Gaussian has a centroid energy of 6.4 +/- 0.1 keV, a width < 0.28 keV and an equivalent width of 940 ^{+650}_{-460} eV. It can be interpreted as fluorescent emission line from iron. Using this model and assuming XTE J0421+56 is at a distance of 5 kpc, its 0.5-10 keV luminosity is 3.5 x 10^{33} erg s^{-1}. The Optical Monitor onboard XMM-Newton indicates a V magnitude of 11.86 +/- 0.03. The spectra of X-ray transients in quiescence are normally modeled using advection dominated accretion flows, power-laws, or by th...

  13. Accurate X-ray position of the Anomalous X-ray Pulsar XTE J1810-197 and identification of its likely IR counterpart

    CERN Document Server

    Israel, G L; Mangano, V; Testa, V; Perna, R; Hummel, W; Mignani, R P; Ageorges, N; Curto, G L; Marco, O; Angelini, L; Campana, S; Covino, S; Marconi, G; Mereghetti, S; Stella, L

    2004-01-01

    We report the accurate sub-arcsec X-ray position of the new Anomalous X-ray Pulsar (AXP) XTE J1810-197, derived with a Chndra-HRC Target of Opportunity observation carried out in November 2003. We also report the discovery of a likely IR counterpart based on a VLT (IR band) Target of Opportunity observation carried out in October 2003. Our proposed counterpart is the only IR source (Ks=20.8) in the X-ray error circle. Its IR colors as well as the X-ray/IR flux ratio, are consistent with those of the counterparts of all other AXPs (at variance with field star colors). Deep Gunn-i band images obtained at the 3.6m ESO telescope detected no sources down to a limiting magnitude of 24.3. Moreover, we find that the pulsed fraction and count rates of XTE J1810-197 remained nearly unchanged since the previous Chandra and XMM-Newton observations (2003 August 27th and September 8th, respectively). We briefly discuss the implications of these results. In particular, we note that the transient (or at least highly variable...

  14. The Transient Accereting X-Ray Pulsar XTE J1946+274: Stability of the X-Ray Properties at Low Flux and Updated Orbital Solution

    CERN Document Server

    Marcu-Cheatham, Diana M; Kühnel, Matthias; Müller, Sebastian; Falkner, Sebastian; Caballero, Isabel; Finger, Mark H; Jenke, Peter J; Wilson-Hodge, Colleen A; Fürst, Felix; Grinberg, Victoria; Hemphill, Paul B; Kreykenbohm, Ingo; Klochkov, Dmitry; Rothschild, Richard E; Terada, Yukikatsu; Enoto, Teruaki; Iwakiri, Wataru; Wolff, Michael T; Becker, Peter A; Wood, Kent S; Wilms, Jöern

    2015-01-01

    We present a timing and spectral analysis of the X-ray pulsar XTE J1946+274 observed with Suzaku during an outburst decline in 2010 October and compare with previous results. XTE J1946+274 is a transient X-ray binary consisting of a Be-type star and a neutron star with a 15.75 s pulse period in a 172 d orbit with 2-3 outbursts per orbit during phases of activity. We improve the orbital solution using data from multiple instruments. The X-ray spectrum can be described by an absorbed Fermi-Dirac cutoff power law model along with a narrow Fe K line at 6.4 keV and a weak Cyclotron Resonance Scattering Feature (CRSF) at ~35 keV. The Suzaku data are consistent with the previously observed continuum flux versus iron line flux correlation expected from fluorescence emission along the line of sight. However, the observed iron line flux is slightly higher, indicating the possibility of a higher iron abundance or the presence of non-uniform material. We argue that the source most likely has only been observed in the sub...

  15. Pilot Candidate Selection

    Science.gov (United States)

    1989-05-01

    pilot selection system and to best support up-front track selection for SUPT? Assumptions The USAF Trainer Masterplan does not include a plan to...replace the T-41 with a new flight screening aircraft. In addition, the Masterplan states that candidates will be track selected prior to entry into primary...training. (3:10) While the Masterplan is not a static document and aircraft procurement plans and/or the timing of track selection are subject to

  16. On the Nature of QPO Phase Lags in Black Hole Candidates

    Science.gov (United States)

    Shaposhnikov, Nikolai

    2012-01-01

    Observations of quasi-periodic oscillations (QPOs) in X-ray binaries hold a key to understanding many aspects of these enigmatic systems. Complex appearance of the Fourier phase lags related to QPOs is one of the most puzzling observational effects in accreting black holes. In this Letter we show that QPO properties, including phase lags, can be explained in a framework of a simple scenario, where the oscillating media provides a feedback on the emerging spectrum. We demonstrate that the QPO waveform is presented by the product of a perturbation and a time delayed response factors, where the response is energy dependent. The essential property of this effect is its non-linear and multiplicative nature. Our multiplicative reverberation model successfully describes the QPO components in energy dependent power spectra as well as the appearance of the phase lags between signal in different energy bands. We apply our model to QPOs observed by Rossi X-ray Timing Explorer in BH candidate XTE J1550-564. We briefly discuss the implications of the observed energy dependence of the QPO reverberation times and amplitudes to the nature of the power law spectral component and its variability.

  17. Abundancias químicas de la compañera visible del agujero negro binario V4641 Sgr (XTE J1819-254)

    Science.gov (United States)

    Cúneo, V. A.; Jofré, E.; Pintado, O. I.; Gómez, M. N.

    2015-08-01

    In this work we expose an analysis of the chemical abundances of the optical companion of the confirmed black hole binary V4641 Sgr (XTE J1819-254) from GMOS spectra obtained with the Gemini North telescope. This analysis allowed to observe an enhancement of N, O, Mg and Si, attributed to the contamination of heavy elements generated during the supernova explosion that gave birth to the black hole. It was also observed that Cr and Fe were subabundant. The aim of this study is to test the formation scenario of a binary system containing a black hole as remnant of the supernova explosion of a massive star, and to provide information to better understand the final stages in the evolution of massive stars and black hole progenitors.

  18. Cross-correlations between soft and hard light curves depending on luminosity in the transient neutron star XTE J1701-462

    Science.gov (United States)

    Wang, Y. N.; Lei, Y. J.; Ding, G. Q.; Qu, J. L.; Ge, M. Y.; Zhang, C. M.; Chen, L.; Ma, X.

    2014-06-01

    Using all the observations from Rossi X-ray Timing Explorer for the accreting neutron star XTE J1701-462, we carry out a systematic study of the cross-correlation function between its soft and hard light curves. Over the entire outburst, XTE J1701-462 evolves from super-Eddington luminosities to quiescence and shows both Z and atoll behaviours. Following previous work, we divide the outburst into five intervals: one Cyg-like interval, three Sco-like intervals and one atoll interval, according to their different behaviours in the corresponding colour-colour diagrams (CCDs). With cross-correlation analyses, anti-correlation, positive and ambiguous correlations are found in the different intervals in this source. Both anti-correlated soft and hard time lags are detected, where hard lags mean that the hard photons lag behind the soft ones and soft lags mean the reverse. In the Cyg-like interval, anti-correlations are presented in the hard vertex and upper normal branch (NB) and positive correlations dominate the horizontal branch (HB) and lower NB. In the first two Sco-like intervals, anti-correlations are detected first and most of them are found in the HB and/or upper NB, while positive correlations are mostly detected in the lower NB and flaring branch (FB). In the following interval, i.e. the third Sco-like interval, anti-correlations occur on the upper FB and positive correlations are mainly distributed in the lower FB. The different intervals correspond to various luminosities; therefore, the position of anti-correlations in the CCD might depend on the luminosity. It is noted that, in the Cyg-like interval, positive correlations dominate the HB, which is not consistent with the behaviour of the Cyg-like Z sources GX 5-1 and Cyg X-2, the HBs of which host ambiguous correlations and anti-correlations. Hence, for comparison with GX 5-1, we analyse the spectra of the HB and the hard vertex of the Cyg-like interval. The fitting results show that, in contrast to GX 5

  19. Enhanced thermoelectricity of three-dimensionally mesostructured BixSb2-xTe3 nanoassemblies: from micro-scaled open gaps to isolated sealed mesopores.

    Science.gov (United States)

    Chen, Tsung-Han; Lin, Ping-Yu; Chang, Hsiu-Cheng; Chen, Chun-Hua

    2017-03-02

    We describe an innovative interfacial design concept and nanostructuring of novel BixSb2-xTe3 (BST) nanoassembled films comprising unique air-solid interfaces from micro-scaled open gaps to isolated sealed mesopores, and high-quality solid-solid ones including the coherent grain boundaries and specific twins, utilizing pulsed laser deposition (PLD), for potentially activating multiple thermoelectric enhancing mechanisms. The unusual mesopore embedded BST films exhibit the highest power factor of ∼33 μW cm(-1) K(-2), which is comparable to or higher than the previously reported values for BST, and the corresponding relatively low thermal diffusivity in contrast to that for dense pore-less BST films evidently reveals the crucial role of the three-dimensionally and densely arranged air-solid interfaces in significantly arising the phonon scattering.

  20. Determination of the far infrared optical constants of η-doped bulk CdxHg1-xTe (CMT) by dispersive fourier transform spectroscopy

    Science.gov (United States)

    Shayesteh, S. Farjami; Dumelow, T.; Parker, T. J.; Benushis, T. I.; Ershov, S. N.; Vasilevskiy, M. I.

    1995-04-01

    Far infrared phase and amplitude reflectivity measurements have been made on two bulk CdxHg1-xTe mixed crystals with composition x=0.29 and x=0.22 by dispersive Fourier transform spectroscopy (DFTS). The results have been used to calculate the real and imaginary parts of the dielectric function (ɛ', ɛ″) from the Fresnel relations. A plasma contribution is observed in the spectra in addition to the phonon response. For both samples a broad but weak reflection band around 95 105 cm-1 is observed as well as the expected two-oscillator response from the HgTe-like and CdTe-like optical phonons. This feature is attributed to absorption due to phonon combination bands, but it is too broad to enable assignments to be made. There is no evidence of additional features in the CdTe region due to clustering.

  1. Rossi X-Ray Timing Explorer and BeppoSAX Observations of the Transient X-Ray Pulsar XTE J1859+083

    Science.gov (United States)

    Corbet, R. H. D.; in't Zand, J. J. M.; Levine, A. M.; Marshall, F. E.

    2009-04-01

    We present observations of the 9.8 s X-ray pulsar XTE J1859+083 made with the All Sky Monitor (ASM) and Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer, and the Wide Field Camera (WFC) on board BeppoSAX. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD 50,250 and 50,460 (1996 June 16 to 1997 January 12). The ASM data excluding this outburst interval suggest a possible modulation with a period of 60.65 ± 0.08 days. Eighteen sets of PCA observations were obtained over an approximately one month interval in 1999. The flux variability measured with the PCA appears consistent with the possible period found with the ASM. The PCA measurements of the pulse period showed it to decrease nonmonotonically and then to increase significantly. Doppler shifts due to orbital motion rather than accretion torques appear to be better able to explain the pulse period changes. Observations with the WFC during the extended outburst give a position that is consistent with a previously determined PCA error box, but which has a significantly smaller error. The transient nature of XTE J1859+083 and the length of its pulse period are consistent with it being a Be/neutron star binary. The possible 60.65 day orbital period would be of the expected length for a Be star system with a 9.8 s pulse period.

  2. Spin effects in high- and low-field magnetotransport experiments in semimagnetic Cd{sub 1-x}Mn{sub x}Te heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Betthausen, Christian

    2012-07-09

    Within the framework of this PhD we report on the very first observation of the fractional Quantum Hall Effect (FQHE) in both, a non-magnetic CdTe and a semimagnetic Cd{sub 1-x}Mn{sub x}Te quantum well device. To our knowledge, this constitutes the first demonstration of this effect in the II-VI material family. Furthermore, our results reveal that the formation of fractional Quantum Hall states is not inhibited by the presence of magnetic impurities in a quantum structure. The second part of this thesis addresses an alternative route to realize efficient spin transistor action. Typically, spin transistor designs relying on spin-orbit interaction principally suffer from low signal levels due to limitations in spin injection efficiency and fast spin decay. Here we present an approach to realize spin transistor action in systems where spin information is protected by propagating it adiabatically. This is achieved by inducing tunable diabatic Landau-Zener transitions that lead to a backscattering of spins and hence allow controlling the transmission of spin-polarized charge carriers through the device, i.e. switching between 'on' and 'off' states. We demonstrate the validity of our approach in a Cd{sub 1-x}Mn{sub x}Te diluted magnetic semiconductor quantum well structure where efficient spin transport is observed over device distances of 50 {mu}m. In contrast to other spin transistor designs we find that our concept is exceptionally tolerant against disorder.

  3. THE TRANSIENT ACCRETING X-RAY PULSAR XTE J1946+274: STABILITY OF X-RAY PROPERTIES AT LOW FLUX AND UPDATED ORBITAL SOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Marcu-Cheatham, Diana M.; Pottschmidt, Katja [CRESST and Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Kühnel, Matthias; Müller, Sebastian; Falkner, Sebastian; Kreykenbohm, Ingo [Dr. Karl Remeis-Observatory and ECAP, University Erlangen-Nuremberg, Sternwartstr. 7, Bamberg (Germany); Caballero, Isabel [Laboratoire AIM, CEA/IRFU, CNRS/INSU, Université Paris Diderot, CEA DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Finger, Mark H. [Universities Space Research Association, National Space Science and Technology Center, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Jenke, Peter J. [University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Wilson-Hodge, Colleen A. [Astrophysics Office, ZP 12, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Fürst, Felix [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Grinberg, Victoria [Massachusetts Institute of Technology, Kavli Institute for Astrophysics, Cambridge, MA 02139 (United States); Hemphill, Paul B.; Rothschild, Richard E. [University of California, San Diego, Center for Astrophysics and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093-0424 (United States); Klochkov, Dmitry [Institut für Astronomie und Astrophysik, Universität Tübingen (IAAT), Sand 1, Tübingen (Germany); Terada, Yukikatsu [Graduate School of Science and Engineering, Saitama University, 255 Simo-Ohkubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); and others

    2015-12-10

    We present a timing and spectral analysis of the X-ray pulsar XTE J1946+274 observed with Suzaku during an outburst decline in 2010 October and compare with previous results. XTE J1946+274 is a transient X-ray binary consisting of a Be-type star and a neutron star with a 15.75 s pulse period in a 172 days orbit with 2–3 outbursts per orbit during phases of activity. We improve the orbital solution using data from multiple instruments. The X-ray spectrum can be described by an absorbed Fermi–Dirac cut-off power-law model along with a narrow Fe Kα line at 6.4 keV and a weak Cyclotron Resonance Scattering Feature (CRSF) at ∼35 keV. The Suzaku data are consistent with the previously observed continuum flux versus iron line flux correlation expected from fluorescence emission along the line of sight. However, the observed iron line flux is slightly higher, indicating the possibility of a higher iron abundance or the presence of non-uniform material. We argue that the source most likely has only been observed in the subcritical (non-radiation dominated) state since its pulse profile is stable over all observed luminosities and the energy of the CRSF is approximately the same at the highest (∼5 × 10{sup 37} erg s{sup −1}) and lowest (∼5 × 10{sup 36} erg s{sup −1}) observed 3–60 keV luminosities.

  4. First-principles calculations of a half-metallic ferromagnet zinc blende Zn{sub 1−x}V{sub x}Te

    Energy Technology Data Exchange (ETDEWEB)

    El Amine Monir, M.; Baltache, H. [Laboratoire de Physique Quantique de la Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique de la Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 (Algeria); Murtaza, G. [Materials Modeling Laboratory, Department of Physics, Islamia College University, Peshawar (Pakistan); Azam, Sikander [New Technologies-Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); Bouhemadou, A. [Laboratory for Developing New Materials and their Characterization, Department of Physics, Faculty of Science, University Setif 1, 19000 Setif (Algeria); Al-Douri, Y. [Institute of Nano Electronic Engineering, University Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Ali, Roshan [Materials Modeling Lab, Department of Physics, Post Graduate Jahanzeb College, Swat (Pakistan)

    2015-03-15

    First-principles calculations have been used to study the structural, elastic, electronic, magnetic and thermal properties of zinc blende Zn{sub 1−x}V{sub x}Te for x=0, 0.25, 0.50, 0.75 and 1 using the full-potential linearized augmented plane wave method (FP-LAPW) based on spin-polarized density functional theory (DFT). The electronic exchange-correlation potential is approached using the spin generalized gradient approximation (spin-GGA). The structural properties of the Zn{sub 1−x}V{sub x}Te alloys (x=0, 0.25, 0.50, 0.75 and 1) are given for the lattice constants and the bulk moduli and their pressure derivatives. The elastic constants C{sub 11}, C{sub 12} and C{sub 44} are calculated using numerical first-principles calculations implemented in the WIEN2k package. An analysis of the band structures and the densities of states reveals that Zn{sub 0.50}V{sub 0.50}Te and Zn{sub 0.75}V{sub 0.25}Te exhibit a half-metallic character, while Zn{sub 0.25}V{sub 0.75}Te is nearly half-metallic. The band structure calculations are used to estimate the spin-polarized splitting energies Δ{sub x}(d) and Δ{sub x}(pd) produced by the V(3d)-doped and s(p)–d exchange constants N{sub 0α} (conduction band) and N{sub 0β} (valence band). The p–d hybridization reduces the magnetic moment of V from its atomic charge value of 3µ{sub B} and creates small local magnetic moments on the nonmagnetic Zn and Te sites. Finally, we present the thermal effect on the macroscopic properties of these alloys, such as the thermal expansion coefficient, heat capacity and Debye temperature, based on the quasi-harmonic Debye model. - Highlights: • Some physical properties of Vanadium doped ZnTe have been investigated. • Structural parameters for the parent compounds compare well with the available data. • The elastic and thermal properties are studied for the first time.

  5. Chevrel-phase solid solution Mo 6Se 8- xTe x. Study of its superconducting, magnetic and NMR properties

    Science.gov (United States)

    Hamard1a, C.; Auffret, V.; Peña, O.; Le Floch, M.; Nowak, B.; Wojakowski, A.

    2000-09-01

    The Chevrel-phase solid solution Mo 6Se 8-Mo 6Te 8 was studied by X-ray diffraction, AC and DC magnetic susceptibility and 77Se and 125Te NMR spectroscopy. From the smooth evolution of the lattice parameters and superconducting critical temperatures, a progressive substitution of selenium atoms by tellurium is shown, on the whole range of composition 0⩽ x⩽8, in the formulation Mo 6Se 8- xTe x: the unit-cell volume increases linearly because of the larger ionic size of tellurium, while Tc decreases rapidly (from 6.45 down to 0 K) because of the different formal oxidation states of the anions and a probable evolution of the Fermi level in the density of states. Results of magnetic susceptibility support this model and suggest the inhibition of the intrinsic metallic behavior with increasing x. The NMR spectra of the binaries Mo 6Se 8 and Mo 6Te 8 reveal two significant features, attributed to two different chalcogen positions in the R 3¯ symmetry. At low Se contents in Mo 6Se 8- xTe x ( x=7.5, 7 and 6), selenium first fills the two X(2) sites along the three-fold axis (2c positions), and then it becomes statistically distributed over the general 6f positions, leading to broad 77Se NMR lines. On the other hand, substitution of Te atoms in Mo 6Se 8 seems to occur in a random way, creating large perturbations on the 125Te NMR spectra, over the whole range of x. Theoretical analysis based on the presence of two anisotropic lines (of axial and non-axial symmetries, respectively) allowed us to estimate their anisotropy factors and to perfectly simulate the frequency response of both Mo 6Se 8 and Mo 6Te 8 binaries. Analysis of the Knight shift anisotropy leads us to conclude about the importance of the molybdenum z 2 molecular orbital contribution which controls the Mo-X dipolar interactions.

  6. X-ray softening in the new X-ray transient XTE J1719-291 during its 2008 outburst decay

    CERN Document Server

    Padilla, M Armas; Patruno, A; Russell, D M; Linares, M; Maccarone, T J; Homan, J; Wijnands, R

    2011-01-01

    The X-ray transient XTE J1719-291 was discovered with RXTE/PCA during its outburst in 2008 March, which lasted at least 46 days. Its 2-10 keV peak luminosity is 7E35 erg/s assuming a distance of 8 kpc, which classifies the system as a very faint X-ray transient. The outburst was monitored with Swift, RXTE, Chandra and XMM-Newton. We analysed the X-ray spectral evolution during the outburst. We fitted the overall data with a simple power-law model corrected for absorption and found that the spectral index increased with decreasing luminosity. However, the XMM-Newton spectrum can not be fitted with a simple one-component model, but it can be fitted with a thermal component (black body or disc black body) plus power-law model affected by absorption. Therefore, the softening of the X-ray spectrum with decreasing X-ray luminosity might be due to a change in photon index or alternatively it might be due to a change in the properties of the soft component. Assuming that the system is an X-ray binary, we estimated a ...

  7. Accretion flow behaviour during the evolution of the Quasi Periodic Oscillation Frequency of XTE J1550-564 in 1998 outburst

    CERN Document Server

    Chakrabarti, Sandip K; Pal, P S

    2009-01-01

    Low and intermediate frequency quasi-periodic oscillations (QPOs) are thought to be due to oscillations of Comptonizing regions or hot regions embedded in Keplerian discs. Observational evidence of evolutions of QPOs would therefore be very important as they throw lights on the dynamics of the hotter region. Our aim is to find systems in which there is a well-defined correlation among the frequencies of the QPOs over a range of time so as to understand the physical picture. In this paper, we concentrate on the archival data of XTE J1550-564 obtained during 1998 outburst, and study the systematic drifts during the rising phase from the 1998 September 7 to the 1998 September 19, when the QPO frequency increased monotonically from 81mHz to 13.1Hz. Immediately after that, QPO frequency started to decrease and on the 1998 September 26, the QPO frequency became 2.62Hz. After that, its value remained almost constant. This frequency drift can be modelled satisfactorily with a propagatory oscillating shock solution wh...

  8. Imaging X-ray, Optical, and Infrared Observations of the Transient Anomalous X-ray Pulsar XTE J1810-197

    CERN Document Server

    Gotthelf, E V; Buxton, M; Bailyn, C D

    2004-01-01

    We report an X-ray study of XTE J1810-197, a 5.54s pulsar discovered by Ibrahim (2003) in recent RXTE observations. In a short exposure with the Chandra HRC camera we detect one source at (J2000) 18:09:51.13, -19:43:51.7 with a 1-sigma uncertainty radius of 2.5 arcsec. Its flux is strongly modulated (58% pulsed fraction) at the expected period. Spectra obtained with XMM-Newton are well fitted by a two-component model that typically describes anomalous X-ray pulsars (AXPs), an absorbed blackbody plus power law with kT = 0.67+/-0.01 keV, Gamma=3.7+/-0.2, N_H=(1.05+/-0.05)E22 cm^-2, and Fx(0.5-10 keV) = 3.98E-11 ergs/cm2/s. Alternatively, a 2-Temp blackbody fit is just as acceptable. The location of CXOU J180951.1-194351 is consistent with an Einstein, Rosat, and ASCA source, when its flux was 75 times fainter, and from which no pulsations are found. The spectrum changed dramatically between the "quiescent" and "active" states, the former can be modeled as a softer blackbody. Using XMM timing data, we place an u...

  9. Electrical conduction mechanism in Se90-xTe5Sn5Inx (x = 0, 3, 6 and 9 multi-component glassy alloys

    Directory of Open Access Journals (Sweden)

    Indra Sen Ram

    2015-08-01

    Full Text Available Electrical conductivity of Se90-xTe5Sn5Inx (x = 0, 3, 6 and 9 glassy systems was studied employing impedance spectroscopic technique in the frequency range 100 Hz to 1 MHz and in the temperature range 308-388 K. The DC conductivity (σdc at each temperature was evaluated from the low frequency plateau region for all the samples under investigation. The bulk conductivity for each sample was also evaluated from Nyquist impedance plots. The semicircle shape of Nyquist plot exhibit dipolar nature of samples. The activation energy for glassy, amorphous and crystalline region from the Arrhenius plot of the DC conductivity and bulk conductivity was evaluated. From the results it is found that activation energy varied from 0.091 to 0.194 eV in glassy, 0.686 to 0.002 eV in amorphous and 0.215 to 0.503 eV in crystalline region. The activation energy (ΔE from DC conductivity and bulk conductivity found to be close in corresponding regions. The pre-exponential factor was also calculated for all three regions.

  10. A measurement of the broad-band spectrum of XTE J1118+480 with BeppoSAX and its astrophysical implications

    CERN Document Server

    Frontera, F; Amati, L; Mikolajewska, J; Belloni, T; Del Sordo, S; Haardt, F; Kuulkers, E; Masetti, N; Orlandini, M; Palazzi, E; Parmar, A N; Remillard, R A; Santangelo, A; Stella, L

    2001-01-01

    We report on results of a target of opportunity observation of the X-ray transient XTE J1118+480 performed on 2000 April 14-15 with the Narrow Field Instruments (0.1-200 keV) of the SAX satellite. The measured spectrum is a power law with a photon index of ~1.7 modified by an ultrasoft X-ray excess and a high-energy cutoff above ~100 keV. The soft excess is consistent with a blackbody with temperature of ~40 eV and a low flux, while the cut-off power law is well fitted by thermal Comptonization in a plasma with an electron temperature of 100 keV and an optical depth of order of unity. Consistent with the weakness of the blackbody, Compton reflection is weak. Though the data are consistent with various geometries of the hot and cold phases of the accreting gas, we conclude that a hot accretion disk is the most plausible model. The Eddington ratio implied by recent estimates of the mass and the distance is about 10^{-3}, which may indicate that advection is probably not the dominant cooling mechanism. We finall...

  11. Cross-correlations between soft and hard light curves depending on luminosity in the transient neutron star XTE J1701-462

    CERN Document Server

    Wang, Ya-Nan; Ding, Guo-Qiang; Qu, Jin-Lu; Ge, Ming-Yu; Zhang, Cheng-Min; Ma, Xiang; Chen, Li

    2014-01-01

    Using all the observations from Rossi X-ray Timing Explorer for accreting neutron star XTE J1701-462, we carry out a systematic study on the cross-correlation between its soft and hard light curves. The anti-correlations appear at the hard vertex and on the upper normal branch (NB) in the Cyg-like interval, occur on the horizontal branch (HB) and/or upper NB in the first and second Sco-like intervals, and display at the upper flaring branch (FB) in the third Sco-like interval. We suggest that the anti-correlation might evolve with luminosity, because with decreasing of luminosity, the source evolved from a Cyg-like Z source, via a Sco-like Z source, to an atoll source. In the Cyg-like interval, the positive correlations are mostly distributed on the HB, which is not consistent with that of the Cyg-like Z source GX 5-1 and Cyg X-2 whose HBs host ambiguous correlations and anti-correlations. From our spectral analyses, it is found that the ratio of the hard emission to the soft emission basically keeps unvaried...

  12. Thin film growth of Cd{sub 1-x}Zn{sub x}Te and its application to X-ray sensor

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, K.; Takahashi, J.; Nakamura, N. [Department of Information Technology and Electronics, Ishinomaki-Senshu University, 1-Shinmito, Minami-sakai 986-0580 (Japan)

    2015-06-15

    Cd{sub 1-x}Zn{sub x}Te (x∝0.5) thin films with less than 300μm are grown on ITO/glass substrate by Hot-wall and PVT methods, one of the sublimation methods. In order to obtain the films with high resistivity and good quality for X-ray sensor, three attempts have been tried in the experiments. The one is stoichiometry control of CZT (x = 0.04) films, which were grown under controlled Cd vapor pressure. The second is excess chlorine doping to the films (x = 0.04) by controlling CdCl{sub 2} vapor pressure during growth process. The third is to change composition x = 0.04-0.50, which increases band gap. Through these methods, best films with good X-ray response was obtained for the third case of the films with the composition x = 0.20. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. XTE J1701-462 and its Implications for the Nature of Subclasses in Low-Magnetic-Field Neutron Star Low-Mass X-Ray Binaries

    CERN Document Server

    Homan, Jeroen; Fridriksson, Joel K; Remillard, Ronald A; Wijnands, Rudy; Mendez, Mariano; Lin, Dacheng; Altamirano, Diego; Casella, Piergiorgio; Belloni, Tomaso; Lewin, Walter H G

    2010-01-01

    We report on an analysis of RXTE data of the transient neutron star low-mass X-ray binary (NS-LMXB) XTE J1701-462, obtained during its 2006-2007 outburst. The X-ray properties of the source changed between those of various types of NS-LMXB subclasses. At high luminosities the source switched between two types of Z source behavior and at low luminosities we observed a transition from Z source to atoll source behavior. These transitions between subclasses primarily manifest themselves as changes in the shapes of the tracks in X-ray color-color and hardness-intensity diagrams, but they are accompanied by changes in the kHz quasi-periodic oscillations, broad-band variability, burst behavior, and/or X-ray spectra. We find that the low-energy X-ray flux is a good parameter to track the gradual evolution of the tracks in color-color and hardness-intensity diagrams, allowing us to resolve the evolution of the source in greater detail than before and relate the observed properties to other NS-LMXBs. We further find th...

  14. An X-ray Timing Study of XTE J1550--564: Evolution of the Low Frequency QPO for the Complete 2000 Outburst

    CERN Document Server

    Rodríguez, J; Kalemci, E; Tomsick, J A; Tagger, M

    2004-01-01

    We report on RXTE observations of the microquasar XTE J1550 during a ~70 day outburst in April-June 2000. We focus here on the temporal properties of the source and study the behavior of low frequency (0.1-10 Hz) quasi periodic oscillations (LFQPO), which seem to be of different types. We focus on the so-called type C (according to the classification of Remillard and collaborators), which corresponds to a strong 0.1-6 Hz LFQPO, found to be present during at least 17 observations. We find that the frequency of the QPO is better correlated with the soft X-ray ( 7 keV). If soft X-rays represent the behavior of an accretion disk, the relation shows that the disk may set the LFQPO frequency. In two cases, the identification of the type of QPO is not straightforward. If the QPOs in those two cases are type A (or B), then we may be seeing the QPO type alternate between type C and type A (or B), and this may represent some rapid changes in the physical properties of the accretion flow, before the system stabilizes an...

  15. Study of the aqueous synthesis, optical and electrochemical characterization of alloyed Zn{sub x}Cd{sub 1-x}Te nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Charlene Regina Santos [Postgraduate Program in Materials Science and Engineering, Federal University of Sergipe, São Cristóvão, SE (Brazil); Candido, Luan P.M.; Souza, Helio Oliveira [Department of Chemistry, Federal University of Sergipe, São Cristóvão, SE (Brazil); Pereira da Costa, Luiz [Institute of Technology and Research (ITP), Tiradentes University, Aracaju, SE (Brazil); Sussuchi, Eliana Midori [Department of Chemistry, Federal University of Sergipe, São Cristóvão, SE (Brazil); Gimenez, Iara F., E-mail: gimenez@ufs.br [Postgraduate Program in Materials Science and Engineering, Federal University of Sergipe, São Cristóvão, SE (Brazil); Department of Chemistry, Federal University of Sergipe, São Cristóvão, SE (Brazil); Postgraduate Program in Chemistry, Federal University of Sergipe, São Cristóvão, SE (Brazil)

    2016-08-01

    The effects of experimental factors such as initial reaction pH, capping ligand, and heating method on the optical and electrochemical properties of aqueous alloyed Zn{sub x}Cd{sub 1-x}Te nanocrystals were evaluated. Here the type of capping ligand (glutathione GSH and 3-mercaptopropionic acid MPA) was found to be the most significant factor in controlling the range of photoluminescence emission. Also a pronounced pH effect on the emission wavelength has been verified in the presence of GSH, in contrast to MPA for which only a minor pH effect was observed. The heating method (microwave or hydrothermal) was found to be irrelevant for the emission wavelength at the conditions studied. The electrochemical characterization in aqueous medium (cyclic voltammetry and differential pulse voltammetry) evidenced a good correlation between electrochemical and optical band gap values and allowed estimation of band edge positions. - Highlights: • ZnCdTe quantum dots were obtained by aqueous synthesis. • Nature of capping ligand was the most relevant factor. • Optical and electrochemical band gaps were well correlated.

  16. Synchrotron radiation photoemission study of Pb{sub 1−x}Cd{sub x}Te crystal with local structure

    Energy Technology Data Exchange (ETDEWEB)

    Orlowski, B.A.; Szczerbakow, A.; Dziawa, P.; Gas, K.; Reszka, A.; Kowalski, B.J. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Thiess, S.; Drube, W. [Hamburger Synchrotronstrahlungslabor HASYLAB am DESY, Notkestr. 85, D-22603 Hamburg (Germany)

    2015-12-01

    The paper presents photoemission study of core level binding energy shifts caused by local crystalline structure collapse in cubic Pb{sub 1−x}Cd{sub x}Te crystal. Photoemission spectra of two kinds of semiconductor samples are compared. The first one is ternary crystal of Pb{sub 0.94}Cd{sub 0.06}Te with the frozen rock salt structure where the crystalline local structure collapse is expected due to the difference of ion radii of Cd and Pb cations. The second sample was the CdTe(22 nm)/PbTe(6 nm)/CdTe(4 μm)/GaAs(1 1 1)B nanostructure grown by molecular beam epitaxy (MBE) method, where crystalline local structure is not expected to be created. The photoemission spectra show that for the crystal with local structure the electron binding energies of cations are higher (e.g. +0.2 eV) whereas for anions they are lower (e.g. −0.08 eV) than in the multilayer structure. A model is proposed to explain obtained results by the local crystalline structure collapse in Pb{sub 0.94}Cd{sub 0.06}Te crystal.

  17. XTE J1859+226: Evolution of spectro-temporal properties, disk-jet connection during 1999 outburst and implications on accretion disk dynamics

    CERN Document Server

    D, Radhika

    2013-01-01

    We investigated the `spectro-temporal' behaviour of the source XTE J1859+226 in X-rays during its outburst phase in 1999, by revisiting the RXTE PCA/HEXTE data in 3 - 150 keV spectral band. Detailed analysis shows that the source evolves through different spectral states during its entire outburst as indicated by the variation in the temporal and spectral features. Evolution of QPO frequencies during rising phase, modeled with propagating oscillatory shock gives an estimate of the oscillating region(corona). Although the evolution pattern of the outburst followed the typical q-shaped profile, we observe an absence of `canonical' soft state and a weak presence of `secondary' emission during the decay phase of the outburst. The broad band spectra, modeled with high energy cutoff, show that fold-energy increases monotonically in the hard and hard-intermediate states followed by a random variation in the soft-intermediate state. These findings make the source evolution more complex. It is also observed that durin...

  18. INTEGRAL sees transient activity in the Galactic Bulge: XTE J1751-305 and GRS 1741.9-2853 in outburst

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Kuulkers, E.; Beckmann, V.;

    2009-01-01

    Crab in above-mentioned energy ranges. IBIS/ISGRI did also detect GRS 1741.9-2853 with an average intensity of about 10 mCrab and significance of 6.1 sigma in the 18-40 keV range. The accreting millisecond X-ray pulsar XTE J1751-305 (e.g. Markwardt et al. ApJ 575, L21, 2002) is detected with JEM-X at 15 +/- 6 m......, the closeby and recently discovered accreting millisecond X-ray pulsar IGR J17511-3057 (e.g. ATels #2196-2199) has dimmed to below the INTEGRAL detection levels, whereas it was still detected 6 days earlier at about 12 mCrab averaged over the above-mentioned energy bands. The 3-sigma upper limits are now...... about 5 mCrab and about 2 mCrab between 3-10 keV and 10-25 keV, respectively. We further notice that none of the X-ray bursters in the close source pair SLX 1744-299/300 is significantly detected in JEM-X with 3-sigma upper limits of about 6 mCrab (3-10 keV) and about 3 mCrab (10-25 keV). This seems...

  19. Extremely Weak Reflection Features in the X-ray Spectrum of XTE J1118+480 Possible Evidence for X-ray-Emitting Jets?

    CERN Document Server

    Miller, J M; Fabian, A C; Lewin, W H G

    2002-01-01

    We have simultaneously fit Chandra and RXTE spectra of the Galactic black hole XTE J1118+480 with three models for X-ray reflection. We explored a range of accretion disc ionizations (log(xi)=1-4; xi=L_X/nR^{2}) and iron abundances (0.10-1.00). Our fits with the constant density ionized disc models of Ross & Fabian indicate that less than 0.5 per cent (90 per cent confidence upper-limit) of the observed flux is reflected. Fits with the "pexrav" of model Magdziarz & Zdziarski indicate that the two-dimensional solid angle (Omega/2pi) subtended by the disc relative to a central source of incident hard X-rays is 0.01 +0.06 -0.01. A combination of the high inclination (i=81 degrees), Comptonization, and bulk velocities may each contribute to the low reflection fractions we have measured. The results are also consistent with extended jets being the source of the hard X-ray flux, as the disc would then represent a small solid angle as seen from the emission region.

  20. An unified timing and spectral model for the Anomalous X-ray Pulsars XTE J1810-197 and CXOU J164710.2-455216

    CERN Document Server

    Albano, A; Israel, G L; Zane, S; Nobili, L; Stella, L

    2010-01-01

    Anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) are two small classes of X-ray sources strongly suspected to host a magnetar, i.e. an ultra-magnetized neutron star with $B\\approx 10^14-10^15 G. Many SGRs/AXPs are known to be variable, and recently the existence of genuinely "transient" magnetars was discovered. Here we present a comprehensive study of the pulse profile and spectral evolution of the two transient AXPs (TAXPs) XTE J1810-197 and CXOU J164710.2-455216. Our analysis was carried out in the framework of the twisted magnetosphere model for magnetar emission. Starting from 3D Monte Carlo simulations of the emerging spectrum, we produced a large database of synthetic pulse profiles which was fitted to observed lightcurves in different spectral bands and at different epochs. This allowed us to derive the physical parameters of the model and their evolution with time, together with the geometry of the two sources, i.e. the inclination of the line-of-sight and of the magnetic axis with resp...

  1. On the nature of the first transient Z-source XTE J1701-462: its accretion disk structure, neutron star magnetic field strength, and hard tail

    CERN Document Server

    Ding, G Q; Wang, N; Qu, J L; Yan, S P

    2011-01-01

    Using the data from the Rossi X-Ray Timing Explorer satellite, we investigate the spectral evolution along a "Z" track and a "v" track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner disk radius depends on the mass accretion rate, in agreement with the model prediction, R_in \\propto ((dM/dt)_disk)^{2/7}, for a radiation pressure dominated accretion disk interacting with the magnetosphere of a neutron star (NS). The changes in the disk mass accretion rate (dM/dt)_disk are responsible for the evolution of the "Z" or "v" track. The radiation pressure thickens the disk considerably, and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation pressure dominated accretion disk, is ~(1--3)X10^9 G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible ori...

  2. 76 FR 4896 - Call for Candidates

    Science.gov (United States)

    2011-01-27

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION: Notice... Federal Accounting Standards Advisory Board (FASAB) is currently seeking candidates (candidates must...

  3. Candidate Prediction Models and Methods

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Madsen, Henrik

    2005-01-01

    This document lists candidate prediction models for Work Package 3 (WP3) of the PSO-project called ``Intelligent wind power prediction systems'' (FU4101). The main focus is on the models transforming numerical weather predictions into predictions of power production. The document also outlines...

  4. Candidate gene prioritization with Endeavour.

    Science.gov (United States)

    Tranchevent, Léon-Charles; Ardeshirdavani, Amin; ElShal, Sarah; Alcaide, Daniel; Aerts, Jan; Auboeuf, Didier; Moreau, Yves

    2016-07-08

    Genomic studies and high-throughput experiments often produce large lists of candidate genes among which only a small fraction are truly relevant to the disease, phenotype or biological process of interest. Gene prioritization tackles this problem by ranking candidate genes by profiling candidates across multiple genomic data sources and integrating this heterogeneous information into a global ranking. We describe an extended version of our gene prioritization method, Endeavour, now available for six species and integrating 75 data sources. The performance (Area Under the Curve) of Endeavour on cross-validation benchmarks using 'gold standard' gene sets varies from 88% (for human phenotypes) to 95% (for worm gene function). In addition, we have also validated our approach using a time-stamped benchmark derived from the Human Phenotype Ontology, which provides a setting close to prospective validation. With this benchmark, using 3854 novel gene-phenotype associations, we observe a performance of 82%. Altogether, our results indicate that this extended version of Endeavour efficiently prioritizes candidate genes. The Endeavour web server is freely available at https://endeavour.esat.kuleuven.be/.

  5. Candidate cave entrances on Mars

    Science.gov (United States)

    Cushing, Glen E.

    2012-01-01

    This paper presents newly discovered candidate cave entrances into Martian near-surface lava tubes, volcano-tectonic fracture systems, and pit craters and describes their characteristics and exploration possibilities. These candidates are all collapse features that occur either intermittently along laterally continuous trench-like depressions or in the floors of sheer-walled atypical pit craters. As viewed from orbit, locations of most candidates are visibly consistent with known terrestrial features such as tube-fed lava flows, volcano-tectonic fractures, and pit craters, each of which forms by mechanisms that can produce caves. Although we cannot determine subsurface extents of the Martian features discussed here, some may continue unimpeded for many kilometers if terrestrial examples are indeed analogous. The features presented here were identified in images acquired by the Mars Odyssey's Thermal Emission Imaging System visible-wavelength camera, and by the Mars Reconnaissance Orbiter's Context Camera. Select candidates have since been targeted by the High-Resolution Imaging Science Experiment. Martian caves are promising potential sites for future human habitation and astrobiology investigations; understanding their characteristics is critical for long-term mission planning and for developing the necessary exploration technologies.

  6. A Unified Timing and Spectral Model for the Anomalous X-ray Pulsars XTE J1810-197 and CXOU J164710.2-455216

    Science.gov (United States)

    Albano, A.; Turolla, R.; Israel, G. L.; Zane, S.; Nobili, L.; Stella, L.

    2010-10-01

    Anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs) are two small classes of X-ray sources strongly suspected to host a magnetar, i.e., an ultra-magnetized neutron star with B ≈ 1014-1015 G. Many SGRs/AXPs are known to be variable, and recently the existence of genuinely "transient" magnetars was discovered. Here, we present a comprehensive study of the pulse profile and spectral evolution of the two transient AXPs (TAXPs) XTE J1810-197 and CXOU J164710.2-455216. Our analysis was carried out in the framework of the twisted magnetosphere model for magnetar emission. Starting from three-dimensional Monte Carlo simulations of the emerging spectrum, we produced a large database of synthetic pulse profiles which was fitted to observed light curves in different spectral bands and at different epochs. This allowed us to derive the physical parameters of the model and their evolution with time, together with the geometry of the two sources, i.e., the inclination of the line of sight and the magnetic axis with respect to the rotation axis. We then fitted the (phase-averaged) spectra of the two TAXPs at different epochs using a model similar to that used to calculate the pulse profiles (ntzang in XSPEC) freezing all parameters to the values obtained from the timing analysis and leaving only the normalization free to vary. This provided acceptable fits to XMM-Newton data in all the observations we analyzed. Our results support a picture in which a limited portion of the star surface close to one of the magnetic poles is heated at the outburst onset. The subsequent evolution is driven both by the cooling/varying size of the heated cap and by a progressive untwisting of the magnetosphere.

  7. Automatic Classification of Kepler Planetary Transit Candidates

    OpenAIRE

    McCauliff, Sean D.; Jenkins, Jon M.; Catanzarite, Joseph; Burke, Christopher J.; Coughlin, Jeffrey L.; Twicken, Joseph D.; Tenenbaum, Peter; Seader, Shawn; Li, Jie; Cote, Miles

    2014-01-01

    In the first three years of operation the Kepler mission found 3,697 planet candidates from a set of 18,406 transit-like features detected on over 200,000 distinct stars. Vetting candidate signals manually by inspecting light curves and other diagnostic information is a labor intensive effort. Additionally, this classification methodology does not yield any information about the quality of planet candidates; all candidates are as credible as any other candidate. The torrent of exoplanet disco...

  8. The influence of Te on thermal properties of Er-doped (Ge{sub 30}(Se{sub 1-x}Te {sub x}){sub 70}){sub 94}Ga{sub 6} chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, K. [Department of Electrical and Electronic Engineering, Miyazaki University, 1-1 Gakuen Kibanadai, Nishi, Miyazaki 889-2192 (Japan)]. E-mail: t0b153u@cc.miyazaki-u.ac.jp; Sakai, T. [Department of Electrical and Electronic Engineering, Miyazaki University, 1-1 Gakuen Kibanadai, Nishi, Miyazaki 889-2192 (Japan); Department of Electrical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, S7N 5A9 (Canada); Tonchev, D. [Department of Electrical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, S7N 5A9 (Canada); Munzar, M. [Department of Electrical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, S7N 5A9 (Canada); Ikari, T. [Department of Electrical and Electronic Engineering, Miyazaki University, 1-1 Gakuen Kibanadai, Nishi, Miyazaki 889-2192 (Japan); Kasap, S.O. [Department of Electrical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK, S7N 5A9 (Canada)

    2005-08-25

    We have studied the thermal properties of Er{sub 2}S{sub 3} doped (Ge{sub 0.30}(Se{sub 1-x}Te {sub x}){sub 0.70}){sub 94}Ga{sub 6} chalcogenide glasses alloyed with different amounts of Te (x = 0.005-0.4). All the samples were doped with 1 at.% of initial amount of Er{sup 3+} ions. The glass composition was chosen with respect to the possible use of this material system in optical amplifier applications operating in the 1550 nm telecommunications window. We have prepared the glass samples by means of melt-quenching techniques using two different synthesis procedures and starting materials. The actual concentrations of glass constituents have been measured by EDX/SEM and WDX/SEM microanalysis techniques. We have carried out temperature-modulated differential scanning calorimetry (TMDSC) measurements to evaluate the thermal stability of these glasses in terms of their glass transformation and crystallization behaviors. Thermal properties of these (Ge{sub 0.30}(Se{sub 1-x}Te {sub x}){sub 0.70}){sub 94}Ga{sub 6} glasses changed substantially for Te content x {>=} 0.01 because of the inability of the original glass structure to accommodate the Te atoms with substantially larger atomic radius.

  9. Material and detector properties of cadmium manganese telluride (Cd{sub 1−x}Mn{sub x}Te) crystals grown by the modified floating-zone method

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, A., E-mail: hossain@bnl.gov; Gu, G.D.; Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Roy, U.N.; Yang, G.; Liu, T.; Zhong, R.; Schneeloch, J.; James, R.B.

    2015-06-01

    We demonstrated the material- and radiation-detection properties of cadmium manganese telluride (Cd{sub 1−x}Mn{sub x}Te; x=0.06), a wide-band-gap semiconductor crystal grown by the modified floating-zone method. We investigated the presence of various bulk defects, such as Te inclusions, twins, and dislocations of several as-grown indium-doped Cd{sub 1−x}Mn{sub x}Te crystals using different techniques, viz., IR transmission microscopy, and chemical etching. We then fabricated four planar detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results show that CMT crystals grown by the modified floating zone method apparently are free from Te inclusions. However, we still need to optimize our growth parameters to attain high-resistivity, large-volume single-crystal CdMnTe.

  10. Enthalpy screen of drug candidates.

    Science.gov (United States)

    Schön, Arne; Freire, Ernesto

    2016-11-15

    The enthalpic and entropic contributions to the binding affinity of drug candidates have been acknowledged to be important determinants of the quality of a drug molecule. These quantities, usually summarized in the thermodynamic signature, provide a rapid assessment of the forces that drive the binding of a ligand. Having access to the thermodynamic signature in the early stages of the drug discovery process will provide critical information towards the selection of the best drug candidates for development. In this paper, the Enthalpy Screen technique is presented. The enthalpy screen allows fast and accurate determination of the binding enthalpy for hundreds of ligands. As such, it appears to be ideally suited to aid in the ranking of the hundreds of hits that are usually identified after standard high throughput screening.

  11. Leishmaniasis: vaccine candidates and perspectives.

    Science.gov (United States)

    Singh, Bhawana; Sundar, Shyam

    2012-06-06

    Leishmania is a protozoan parasite and a causative agent of the various clinical forms of leishmaniasis. High cost, resistance and toxic side effects of traditional drugs entail identification and development of therapeutic alternatives. The sound understanding of parasite biology is key for identifying novel drug targets, that can induce the cell mediated immunity (mainly CD4+ and CD8+ IFN-gamma mediated responses) polarized towards a Th1 response. These aspects are important in designing a new vaccine along with the consideration of the candidates with respect to their ability to raise memory response in order to improve the vaccine performance. This review is an effort to identify molecules according to their homology with the host and their ability to be used as potent vaccine candidates.

  12. Toward organometallic antischistosomal drug candidates.

    Science.gov (United States)

    Hess, Jeannine; Keiser, Jennifer; Gasser, Gilles

    2015-01-01

    In the recent years, there has been a growing interest in the use of novel approaches for the treatment of parasitic diseases such as schistosomiasis. Among the different approaches used, organometallic compounds were found to offer unique opportunities in the design of antiparasitic drug candidates. A ferrocenyl derivative, namely ferroquine, has even entered clinical trials as a novel antimalarial. In this short review, we report on the studies describing the use of organometallic compounds against schistosomiasis.

  13. Imaging Dirac-Mass Disorder from Magnetic Dopant-Atoms in the Ferromagnetic Topological Insulator Crx(Bi0.1Sb0.9)2-xTe3 - Part II

    Science.gov (United States)

    Lee, Inhee; Kim, Chung Koo; Lee, Jinho; Billinge, Simon; Zhong, Ruidan; Schneeloch, John; Liu, Tiansheng; Tranquada, John; Gu, Genda; Davis, J. C.

    2015-03-01

    We present Part II of the spectroscopic imaging - scanning tunneling microscopy (SI-STM) study of ferromagnetic Crx(Bi0.1Sb0.9)2-xTe3 single crystals measured at 4.5 K. As Part II we show how both spectroscopic analysis in real and momentum space demonstrate the coincident Dirac mass gap identified. Distribution of gap width, gap center, and gap anisotropy will be discussed. The anticipated relationship Δ (r) ~ n (r) is confirmed throughout, and exhibits an electron-dopant interaction energy J* = 145 meV .nm2. These observations reveal how magnetic dopant atoms actually generate the TI mass gap and that, to achieve the novel physics expected of time-reversal-symmetry breaking TI materials, control of the resulting Dirac-mass gap disorder will be essential.

  14. Teacher Candidates' Communication Skills and Communicator Styles

    OpenAIRE

    Cem ÇUHADAR; Özgür, Hasan; Akgün, Fatma; GÜNDÜZ, Şemseddin

    2015-01-01

    The purpose of this study is to find out the relationship between the communication skills and the communicator styles of teacher candidates. This research was conducted among the senior class students, studying at Trakya University, Faculty of Education in the fall semester of the 2012-2013 academic year. 205 women and 110 men, in a total of 315 teacher candidates participated in the research. As a result, it has been observed that the teacher candidates bear animated/expressive features the...

  15. Evaluating historical candidate genes for schizophrenia

    DEFF Research Database (Denmark)

    Farrell, M S; Werge, T; Sklar, P

    2015-01-01

    Prior to the genome-wide association era, candidate gene studies were a major approach in schizophrenia genetics. In this invited review, we consider the current status of 25 historical candidate genes for schizophrenia (for example, COMT, DISC1, DTNBP1 and NRG1). The initial study for 24 of thes...

  16. Undercover Stars Among Exoplanet Candidates

    Science.gov (United States)

    2005-03-01

    events by monitoring the brightness of a very large number of stars over extended time intervals. During the past years, it has also included a search for periodic, very shallow "dips" in the brightness of stars, caused by the regular transit of small orbiting objects (small stars, brown dwarfs [2] or Jupiter-size planets). The OGLE team has since announced 177 "planetary transit candidates" from their survey of several hundred thousand stars in three southern sky fields, one in the direction of the Galactic Centre, another within the Carina constellation and the third within the Centaurus/Musca constellations. The nature of the transiting object can however only be established by subsequent radial-velocity observations of the parent star. The size of the velocity variations (the amplitude) is directly related to the mass of the companion object and therefore allows discrimination between stars and planets as the cause of the observed brightness "dip". A Bonanza of Low-Mass Stars An international team of astronomers [3] has made use of the 8.2-m VLT Kueyen telescope for this work. Profiting from the multiplex capacity of the FLAMES/UVES facility that permits to obtain high-resolution spectra of up to 8 objects simultaneously, they have looked at 60 OGLE transit candidate stars, measuring their radial velocities with an accuracy of about 50 m/s [4]. This ambitious programme has so far resulted in the discovery of five new transiting exoplanets (see, e.g., ESO PR 11/04 for the announcement of two of those). Most of the other transit candidates identified by OGLE have turned out to be eclipsing binaries, that is, in most cases common, small and low-mass stars passing in front of a solar-like star. This additional wealth of data on small and light stars is a real bonanza for the astronomers. Constraining the Relation Between Mass and Radius Low-mass stars are exceptionally interesting objects, also because the physical conditions in their interiors have much in common with

  17. Cattle Candidate Genes for Milk Production Traits

    OpenAIRE

    Kadlec, Tomáš

    2012-01-01

    The aim of this thesis is to make an overview of important candidate genes affecting milk yield and milk quality parameters, with an emphasis on genes associated with the quantity and quality of milk proteins and milk fat.

  18. New Zika Vaccine Candidate Provides Powerful Protection

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163384.html New Zika Vaccine Candidate Provides Powerful Protection Made without live ... HealthDay News) -- A single dose of an experimental Zika vaccine protected mice and monkeys from the virus, ...

  19. Bioinformatics methods for identifying candidate disease genes

    NARCIS (Netherlands)

    Driel, M.A. van; Brunner, H.G.

    2006-01-01

    With the explosion in genomic and functional genomics information, methods for disease gene identification are rapidly evolving. Databases are now essential to the process of selecting candidate disease genes. Combining positional information with disease characteristics and functional information i

  20. Towards Treating Chemistry Teacher Candidates as Human

    Science.gov (United States)

    Lewthwaite, Brian Ellis

    2008-05-01

    This research inquiry investigates the factors influencing chemistry teacher candidates’ development during their extended practica in the second and final year of an After-Degree Bachelor of Education at a university in central Canada. A variety of data sources are used to identify the risk and protective factors impeding and contributing to the achievement of their chemistry pedagogical aspirations. Two theoretical frameworks, both having their origins in the pioneering work of Kurt Lewin, are used to conceptualize how a complex amalgam of personal attribute and environmental factors and the interplay among these factors influence teacher candidate developmental trajectories. The tenets of both Bronfenbrenner’s bioecological model and Learning Environment research provide insights into how the factors influencing teacher candidate development can be understood and systematically documented to provide a template for reflective consideration of the practicum experience for both teacher candidates and those involved in fostering the development of chemistry teacher candidates.

  1. Bioinformatics methods for identifying candidate disease genes

    Directory of Open Access Journals (Sweden)

    van Driel Marc A

    2006-06-01

    Full Text Available Abstract With the explosion in genomic and functional genomics information, methods for disease gene identification are rapidly evolving. Databases are now essential to the process of selecting candidate disease genes. Combining positional information with disease characteristics and functional information is the usual strategy by which candidate disease genes are selected. Enrichment for candidate disease genes, however, depends on the skills of the operating researcher. Over the past few years, a number of bioinformatics methods that enrich for the most likely candidate disease genes have been developed. Such in silico prioritisation methods may further improve by completion of datasets, by development of standardised ontologies across databases and species and, ultimately, by the integration of different strategies.

  2. Do People 'Like' Candidates on Facebook?

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    The online popularity of a few exceptional candidates has led many to suggest that social media have given politicians powerful ways of communicating directly with voters. In this paper, we examine whether this is happening on a significant scale and show, based on analysis of 224 candidates....... We therefore suggest that the political implications of social media are generally better understood in terms of facilitating indirect communication and institutional change than in terms of direct communication....

  3. Cardiac evaluation of liver transplant candidates

    Institute of Scientific and Technical Information of China (English)

    Mercedes Susan Mandell; JoAnn Lindenfeld; Mei-Yung Tsou; Michael Zimmerman

    2008-01-01

    Physicians previously thought that heart disease was rare in patients with end stage liver disease. However, recent evidence shows that the prevalence of ischemic heart disease and cardiomyopathy is increased in transplant candidates compared to most other surgical candidates. Investigators estimate that up to 26% of all liver transplant candidates have at least one critical coronary artery stenosis and that at least half of these patients will die perioperatively of cardiac complications. Cardiomyopathy also occurs in greater frequency. While all patients with advanced cardiac disease have defects in cardiac performance, a larger than expected number of patients have classical findings of dilated, restrictive and hypertropic cardiomyopathy. This may explain why up to 56% of patients suffer from hypoxemia due to pulmonary edema following transplant surgery. There is considerable controversy on how to screen transplant candidates for the presence of heart disease. Questions focus upon, which patients should be screened and what tests should be used. This review examines screening strategies for transplant candidates and details the prognostic value of common tests used to identify ischemic heart disease. We also review the physiological consequences of cardiomyopathy in transplant candidates and explore the specific syndrome of "cirrhotic cardiomyopathy".

  4. A New Way to Confirm Planet Candidates

    Science.gov (United States)

    Kohler, Susanna

    2016-05-01

    What was the big deal behind the Kepler news conference yesterday? Its not just that the number of confirmed planets found by Kepler has more than doubled (though thats certainly exciting news!). Whats especially interesting is the way in which these new planets were confirmed.Number of planet discoveries by year since 1995, including previous non-Kepler discoveries (blue), previous Kepler discoveries (light blue) and the newly validated Kepler planets (orange). [NASA Ames/W. Stenzel; Princeton University/T. Morton]No Need for Follow-UpBefore Kepler, the way we confirmed planet candidates was with follow-up observations. The candidate could be validated either by directly imaging (which is rare) or obtaining a large number radial-velocity measurements of the wobble of the planets host star due to the planets orbit. But once Kepler started producing planet candidates, these approaches to validation became less feasible. A lot of Kepler candidates are small and orbit faint stars, making follow-up observations difficult or impossible.This problem is what inspired the development of whats known as probabilistic validation, an analysis technique that involves assessing the likelihood that the candidates signal is caused by various false-positive scenarios. Using this technique allows astronomers to estimate the likelihood of a candidate signal being a true planet detection; if that likelihood is high enough, the planet candidate can be confirmed without the need for follow-up observations.A breakdown of the catalog of Kepler Objects of Interest. Just over half had previously been identified as false positives or confirmed as candidates. 1284 are newly validated, and another 455 have FPP of1090%. [Morton et al. 2016]Probabilistic validation has been used in the past to confirm individual planet candidates in Kepler data, but now Timothy Morton (Princeton University) and collaborators have taken this to a new level: they developed the first code thats designed to do fully

  5. JELLYFISH GALAXY CANDIDATES AT LOW REDSHIFT

    Energy Technology Data Exchange (ETDEWEB)

    Poggianti, B. M.; Fasano, G.; Omizzolo, A.; Gullieuszik, M.; Bettoni, D.; Paccagnella, A. [INAF-Astronomical Observatory of Padova (Italy); Moretti, A.; D’Onofrio, M. [Physics and Astronomy Department, University of Padova (Italy); Jaffé, Y. L. [Department of Astronomy, Universidad de Concepción, Concepción (Chile); Vulcani, B. [Kavli Institute for the Physics and Mathematics of the universe (WPI), The University of Tokyo Institutes for Advanced Study (UTIAS), the University of Tokyo, Kashiwa, 277-8582 (Japan); Fritz, J. [Centro de Radioastronomía y Astrofísica, CRyA, UNAM, Michoacán (Mexico); Couch, W. [Australian Astronomical Observatory, North Ryde, NSW 1670 (Australia)

    2016-03-15

    Galaxies that are being stripped of their gas can sometimes be recognized from their optical appearance. Extreme examples of stripped galaxies are the so-called “jellyfish galaxies” that exhibit tentacles of debris material with a characteristic jellyfish morphology. We have conducted the first systematic search for galaxies that are being stripped of their gas at low-z (z = 0.04−0.07) in different environments, selecting galaxies with varying degrees of morphological evidence for stripping. We have visually inspected B- and V-band images and identified 344 candidates in 71 galaxy clusters of the OMEGAWINGS+WINGS sample and 75 candidates in groups and lower mass structures in the PM2GC sample. We present the atlas of stripping candidates and a first analysis of their environment and their basic properties, such as morphologies, star formation rates and galaxy stellar masses. Candidates are found in all clusters and at all clustercentric radii, and their number does not correlate with the cluster velocity dispersion σ or X-ray luminosity L{sub X}. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (10{sup 11}−10{sup 14}M{sub ⊙}), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M{sub ⊙} < 9 to > 11.5 and the majority of them form stars at a rate that is on average a factor of 2 higher (2.5σ) compared to non-stripped galaxies of similar mass. The few post-starburst and passive candidates have weak stripping evidence. We conclude that disturbed morphologies suggestive of stripping phenomena are ubiquitous in clusters and could be present even in groups and low mass halos. Further studies will reveal the physics of the gas stripping and clarify the mechanisms at work.

  6. Jellyfish Galaxy Candidates at Low Redshift

    Science.gov (United States)

    Poggianti, B. M.; Fasano, G.; Omizzolo, A.; Gullieuszik, M.; Bettoni, D.; Moretti, A.; Paccagnella, A.; Jaffé, Y. L.; Vulcani, B.; Fritz, J.; Couch, W.; D'Onofrio, M.

    2016-03-01

    Galaxies that are being stripped of their gas can sometimes be recognized from their optical appearance. Extreme examples of stripped galaxies are the so-called “jellyfish galaxies” that exhibit tentacles of debris material with a characteristic jellyfish morphology. We have conducted the first systematic search for galaxies that are being stripped of their gas at low-z (z = 0.04-0.07) in different environments, selecting galaxies with varying degrees of morphological evidence for stripping. We have visually inspected B- and V-band images and identified 344 candidates in 71 galaxy clusters of the OMEGAWINGS+WINGS sample and 75 candidates in groups and lower mass structures in the PM2GC sample. We present the atlas of stripping candidates and a first analysis of their environment and their basic properties, such as morphologies, star formation rates and galaxy stellar masses. Candidates are found in all clusters and at all clustercentric radii, and their number does not correlate with the cluster velocity dispersion σ or X-ray luminosity LX. Interestingly, convincing cases of candidates are also found in groups and lower mass halos (1011-1014M⊙), although the physical mechanism at work needs to be securely identified. All the candidates are disky, have stellar masses ranging from log M/M⊙ 11.5 and the majority of them form stars at a rate that is on average a factor of 2 higher (2.5σ) compared to non-stripped galaxies of similar mass. The few post-starburst and passive candidates have weak stripping evidence. We conclude that disturbed morphologies suggestive of stripping phenomena are ubiquitous in clusters and could be present even in groups and low mass halos. Further studies will reveal the physics of the gas stripping and clarify the mechanisms at work.

  7. Properties of the relaxation time distribution underlying the Kohlrausch-Williams-Watts photoionization of the DX centers in Cd{sub 1-x}Mn{sub x}Te mixed crystals

    Energy Technology Data Exchange (ETDEWEB)

    Trzmiel, J; Weron, K; Placzek-Popko, E [Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland); Janczura, J [Hugo Steinhaus Center for Stochastic Methods and Institute of Mathematics and Computer Science, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2009-08-26

    In this paper we clarify the relationship between the relaxation rate and relaxation time distributions underlying the Kohlrausch-Williams-Watts (KWW) photoconductivity build-ups in indium- and gallium-doped Cd{sub 1-x}Mn{sub x}Te mixed crystals. We discuss the role of asymptotic properties of the corresponding probability density functions. We show that the relaxation rate distribution, as a completely asymmetric alpha-stable distribution, leads to an infinite mean value of the effective relaxation rate. In contrast, the relaxation time distribution related to it leads to a finite mean value of the effective relaxation time. It follows from the experimental data analysis that for all the investigated samples the KWW exponent alpha decreases linearly with increasing photon flux in the range of (0.6-0.99) and its values are more spread in the case of gallium-doped material. We also observe a linear dependence of the mean relaxation time on the characteristic material time constant, which is consistent with the theoretical model.

  8. FP-LAPW methodology based theoretical investigation of structural, electronic and optical properties of MgxPb1-xS, MgxPb1-xSe and MgxPb1-xTe ternary alloys

    Science.gov (United States)

    Chattopadhyaya, Surya; Bhattacharjee, Rahul

    2017-01-01

    The structural, electronic and optical properties of MgxPb1-xS, MgxPb1-xSe and MgxPb1-xTe alloys for 0≤ x≤1 in their rock-salt (B1) crystallographic phase have been calculated using the full-potential linearized augmented plane wave (FP-LAPW) method under the framework of density functional theory (DFT). Using the Wu-Cohen generalized-gradient approximation (WC-GGA) induced exchange-correlation potential scheme, the ground state structural parameters such as equilibrium lattice constants, bulk modulus and its pressure derivatives are calculated and deviations of the lattice constants from Vegard's law and the bulk modulus from linear concentration dependence have been observed for the alloys. Electronic band structures and density of states have been calculated using Tran-Blaha modified Becke-Johnsoexit3b2tex.batn (TB-mBJ) parameterization scheme to study the electronic properties of the binary compounds and their ternary alloys. Using the approach of Zunger and co-workers, the microscopic origins of band gap bowing have been discussed in term of volume deformation, charge exchange and structural relaxation. Optical properties of the binary compounds and their ternary alloys have been calculated in terms of their respective dielectric function, refractive index, reflectivity and optical conductivity. Few calculated results are compared with available experimental and other theoretical data.

  9. Propeller-Effect Interpretation of MAXI/GSC Light Curves of 4U 1608-52 and AqlX-1 and application to XTE J1701-462

    CERN Document Server

    Asai, K; Mihara, T; Sugizaki, M; Serino, M; Nakahira, S; Negoro, H; Ueda, Y; Yamaoka, K

    2013-01-01

    We present the luminosity dwell-time distributions during the hard states of low-mass X-ray binaries containing a neutron star, 4U 1608-52 and AqlX-1, observed with MAXI/GSC. The luminosity distributions show a steep cut-off in the low-luminosity side at $\\sim1.0 \\times 10^{36}$ erg s$^{-1}$ in both the two sources. The cut-off implies a rapid luminosity decrease in their outburst decay phases, and the feature can be interpreted as due the propeller effect. We estimated the surface magnetic field of the neutron star to be (0.5--1.6) $\\times 10^8$ G in 4U 1608-52 and (0.6--1.9) $\\times 10^8$ G in AqlX-1 from the cut-off luminosity. We applied the same propeller mechanism to the similar rapid luminosity decrease observed in the transient Z-source, XTE J1701-462, with RXTE/ASM. Assuming that spin period of the neutron star is in the order of milliseconds, the observed cut-off luminosity deduces surface magnetic field in the order of $10^9$ G.

  10. Evaluating historical candidate genes for schizophrenia.

    Science.gov (United States)

    Farrell, M S; Werge, T; Sklar, P; Owen, M J; Ophoff, R A; O'Donovan, M C; Corvin, A; Cichon, S; Sullivan, P F

    2015-05-01

    Prior to the genome-wide association era, candidate gene studies were a major approach in schizophrenia genetics. In this invited review, we consider the current status of 25 historical candidate genes for schizophrenia (for example, COMT, DISC1, DTNBP1 and NRG1). The initial study for 24 of these genes explicitly evaluated common variant hypotheses about schizophrenia. Our evaluation included a meta-analysis of the candidate gene literature, incorporation of the results of the largest genomic study yet published for schizophrenia, ratings from informed researchers who have published on these genes, and ratings from 24 schizophrenia geneticists. On the basis of current empirical evidence and mostly consensual assessments of informed opinion, it appears that the historical candidate gene literature did not yield clear insights into the genetic basis of schizophrenia. A likely reason why historical candidate gene studies did not achieve their primary aims is inadequate statistical power. However, the considerable efforts embodied in these early studies unquestionably set the stage for current successes in genomic approaches to schizophrenia.

  11. Development of a highly efficient conversion electron Moessbauer spectroscopy (CEMS) detector for low temperature (<20 K) measurements and tests on Fe / (Eu{sub x}Pb{sub 1-x})Te bilayers; Desenvolvimento de um detector de alta eficiencia para espectroscopia Moessbauer de eletrons de conversao (CEMS) a baixas temperaturas (<20K) e testes em bicamadas Fe / (Eu{sub x}Pb{sub 1-x})Te

    Energy Technology Data Exchange (ETDEWEB)

    Pombo, Carlos Jose da Silva Matos

    2006-07-01

    The {sup 57}Fe Moessbauer spectroscopy is a nuclear, non-destructive technique used for the investigation of structural, magnetic and hyperfine properties of several materials. It is a powerful tool in characterizing materials in physics, metallurgy, geology and biology field areas, especially magnetic materials, alloys and minerals containing Fe. Lately, the Conversion Electron Moessbauer Spectroscopy (CEMS) is widely used in making studies on ultra-thin magnetic films, as well as other nanostructured materials. In case of magnetic nanostructures, low temperature (LT) studies are especially important due to the possibility of dealing with superparamagnetic effects. In this work it was developed a CEMS measurement system for low temperatures (<20 K) based on a solid-state electron multiplier (Channeltron{sup R}) and an optical cryostat (Model SVT-400, Janis Research Co, USA), from which the project was originally conceived at the Applied Physics / Moessbauer spectroscopy Department from University of Duisburg-Essen, Germany. The LT-CEMS system was fully built, tested and successfully applied in a preliminary characterization of Fe/(Eu{sub x}Pb{sub 1-x})Te(111) bilayers with use of a 15 angstrom, {sup 57} Fe probe layer, with reasonable results at sample temperatures as low as 8 K. (author)

  12. Interviews with candidates for president transmitted

    Directory of Open Access Journals (Sweden)

    Wilson Gomes

    2012-07-01

    Full Text Available In election years, television interviews with presidential candidates, broadcast live, i.e. without the use of editing, have become an important genre of journalistic representation in Brazilian political campaigns. These interviews are conducted in network studios by well-known Brazilian news anchors. The fact that these interviews are transmitted directly to the electorate in an unedited form is generally offered as a guarantee of a genuine, authentic portrayal of the candidates themselves. The present work proposes that live network candidate interviews, rather than a means of political presentation on television, are actually an arena in which the institution of journalism attempts to use rhetorical and argumentative means to control the candidates’ discourse without relying on the traditional advantages conferred in daily news coverage.

  13. 米其林加快适应中国市场——向中国推出节能、高效卡车/挂车轮胎XZA 2 Energy和XTE 2%Michelin Plan to Introduce New High-tech Tyre Products to China Market

    Institute of Scientific and Technical Information of China (English)

    王作函

    2010-01-01

    @@ 2010年1月20日,米其林在京宣布向中国市场推出2款专门为中国用户定制的节能、高效卡车轮胎--XZA 2 Energy和XTE 2.同时,新上任的米其林卡客车轮胎部高级副总裁夏茂廷还对米其林卡客车轮胎下一步在中国的发展作了介绍.

  14. Candidal Leukoplakia on Patient with Removable Denture

    Directory of Open Access Journals (Sweden)

    Shiril Paskalis

    2013-07-01

    Full Text Available Candida infection is a common problem in patients using removable dentures, with the most frequent type is denture stomatitis. But other type of candidal infection could also happen in these patients, such as candidal leukoplakia. We reported a 61 years old female patient who complained a painful lesion under her lower removable denture. Oral examination revealed white plaque that could not be rubbed over an ulcer on the lingual part of alveolar processes under the lower removable denture plate, and also an erythematous area on palatum durum above the upper full denture. The patient was suspected to have candidal leukoplakia on the lingual part of the mandible and denture stomatitis on the palate area. The treatment consisted of nystatin oral suspension, chlorhexidine solution, multivitamins, along with denture replacement and oral health education. The entire lesion resolved within 2 months therapy. Candidal infection treatment on denture patient needs not only medication or denture replacement, but also patient compliance to achieve maximal result.

  15. Fuzzy Treatment of Candidate Outliers in Measurements

    Directory of Open Access Journals (Sweden)

    Giampaolo E. D'Errico

    2012-01-01

    Full Text Available Robustness against the possible occurrence of outlying observations is critical to the performance of a measurement process. Open questions relevant to statistical testing for candidate outliers are reviewed. A novel fuzzy logic approach is developed and exemplified in a metrology context. A simulation procedure is presented and discussed by comparing fuzzy versus probabilistic models.

  16. Candidate genes in ocular dominance plasticity

    NARCIS (Netherlands)

    M.L. Rietman; J.-P. Sommeijer; C.N. Levelt; J.A. Heimel; A.B. Brussaard; J.G.G. Borst; Y. Elgersma; N. Galjart; G.T. van der Horst; C.M. Pennartz; A.B. Smit; B.M. Spruijt; M. Verhage; C.I. de Zeeuw

    2012-01-01

    Many studies have been devoted to the identification of genes involved in experience-dependent plasticity in the visual cortex. To discover new candidate genes, we have reexamined data from one such study on ocular dominance (OD) plasticity in recombinant inbred BXD mouse strains. We have correlated

  17. Secondary Teacher Candidates' Lesson Planning Learning

    Science.gov (United States)

    Santoyo, Christina; Zhang, Shaoan

    2016-01-01

    Teacher candidates (TCs) use clinical experiences to enact concepts taught in their university courses; therefore field experiences may be the most important component of teacher preparation (Hammerness et al., 2005). TCs require support and guidance as they learn to adapt curriculum materials for effective use in the classroom (Davis, 2006). They…

  18. Teacher Candidate Portfolios: Routine or Reflective Action?

    Science.gov (United States)

    McIntyre, Christie; Dangel, Julie Rainer

    2009-01-01

    Documentation is sparse regarding outcomes associated with teacher education portfolios and the quality of the reflections contained within the portfolios. This collective case study of six teacher candidates enrolled in an elementary teacher education program at a large midwestern university explores the outcomes of developing a portfolio based…

  19. Query by image example: The CANDID approach

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.M.; Cannon, M. [Los Alamos National Lab., NM (United States). Computer Research and Applications Group; Hush, D.R. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering

    1995-02-01

    CANDID (Comparison Algorithm for Navigating Digital Image Databases) was developed to enable content-based retrieval of digital imagery from large databases using a query-by-example methodology. A user provides an example image to the system, and images in the database that are similar to that example are retrieved. The development of CANDID was inspired by the N-gram approach to document fingerprinting, where a ``global signature`` is computed for every document in a database and these signatures are compared to one another to determine the similarity between any two documents. CANDID computes a global signature for every image in a database, where the signature is derived from various image features such as localized texture, shape, or color information. A distance between probability density functions of feature vectors is then used to compare signatures. In this paper, the authors present CANDID and highlight two results from their current research: subtracting a ``background`` signature from every signature in a database in an attempt to improve system performance when using inner-product similarity measures, and visualizing the contribution of individual pixels in the matching process. These ideas are applicable to any histogram-based comparison technique.

  20. Emotional Intelligence and Beginning Teacher Candidates

    Science.gov (United States)

    Justice, Madeline; Espinoza, Sue

    2007-01-01

    According to the Bureau of Labor Statistics, Texas will need over 82,000 new teachers by 2008. Many teachers are leaving the profession within 5 years of being employed. Closing a revolving door, teacher preparation programs are discussing this phenomenon. One hundred sixty beginning teacher candidates were surveyed using the Emotional Skills…

  1. Spectroscopy of Hyades L dwarf candidates

    CERN Document Server

    Lodieu, N; Bejar, V J S

    2014-01-01

    We present the results of photometric, astrometric, and spectroscopic follow-up of L dwarf candidates identified in the Hyades cluster by Hogan et al. (2008). We obtained low-resolution optical spectroscopy with the OSIRIS spectrograph on the Gran Telescopio de Canarias for all 12 L dwarf candidates as well as new J-band imaging for a subsample of eight to confirm their proper motion. We also present mid-infrared photometry from the Wise Field Infrared Survey Explorer (WISE) for the Hyades L and T dwarf candidates and estimate their spectroscopic distances, effective temperatures, and masses. We confirm the cool nature of several L dwarf candidates and confirm astrometrically their membership, bridging the gap between the coolest M dwarfs and the two T dwarfs previously reported in the Hyades cluster. These members represent valuable spectral templates at an age of 625 Myr and slightly super solar metallicity (Fe/H=+0.13). We update the Hyades mass function across the hydrogen-burning limit and in the substel...

  2. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.;

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing ...

  3. Towards Treating Chemistry Teacher Candidates as Human

    Science.gov (United States)

    Lewthwaite, Brian Ellis

    2008-01-01

    This research inquiry investigates the factors influencing chemistry teacher candidates' development during their extended practica in the second and final year of an After-Degree Bachelor of Education at a university in central Canada. A variety of data sources are used to identify the risk and protective factors impeding and contributing to the…

  4. Promoting Team Leadership Skills in Doctoral Candidates

    Science.gov (United States)

    Suleiman, Mahmoud; Whetton, Danny

    2014-01-01

    Doctoral programs can serve as an optimal opportunity for candidates to engage in tasks and activities to transform them and their schools. The paradigm shifts in such preparation involve moving from sitting and getting to making and taking. Most importantly, it requires building leadership skills and styles necessary to bring about desired change…

  5. Teacher Candidate Disposition: Moral Judgement or Regurgitation?

    Science.gov (United States)

    Johnson, Lisa E.

    2008-01-01

    Developing teacher candidates who are able to make moral judgements to equitably resolve classroom dilemmas, conduct student assessment and allocate resources is critical for today's diverse classrooms and should be part of fostering professional disposition. However, one challenge of incorporating dispositions in teacher education and a valid…

  6. Gallium-67 imaging in candidal esophagitis

    Energy Technology Data Exchange (ETDEWEB)

    Rundback, J.H.; Goldfarb, C.R.; Ongseng, F. (Beth Israel Medical Center, New York, NY (USA))

    1990-01-01

    Ga-67 scanning has been used to evaluate esophageal carcinoma. It has demonstrated candidal infection in other body sites and, in one previous case, in the esophagus. The authors present a case of diffuse esophageal uptake of Ga-67 in esophageal candidiasis.

  7. 76 FR 36130 - Call for Candidates

    Science.gov (United States)

    2011-06-21

    ... From the Federal Register Online via the Government Publishing Office FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting Standards Advisory Board. ACTION: Request for... Accounting Standards Advisory Board (FASAB or the Board) with the requested materials in response to...

  8. 11 CFR 9003.2 - Candidate certifications.

    Science.gov (United States)

    2010-01-01

    ... excess of the aggregate payments to which they will be entitled under 11 CFR part 9004. (2) That no... funds under 11 CFR 9003.2(c)(3) shall not count against such candidate's $50,000 expenditure limitation... expenditures in excess of the limitations of 11 CFR 110.8(a), the Commission may seek civil penalties under...

  9. Candidate genes in ocular dominance plasticity

    Directory of Open Access Journals (Sweden)

    M. Liset Rietman

    2012-02-01

    Full Text Available The objective of this study was to identify new candidate genes involved in experience-dependent plasticity. To this aim, we combined previously obtained data from recombinant inbred BXD strains on ocular dominance (OD plasticity and gene expression levels in the neocortex. We validated our approach using a list of genes which alter OD plasticity when inactivated. The expression levels of one fifth of these genes correlated with the amount of OD plasticity. Moreover, the two genes with the highest relative inter-strain differences were among the correlated genes. This suggests that correlation between gene expression levels and OD plasticity is indeed likely to point to genes with a causal role in modulating or generating plasticity in the visual cortex. After this validation on known plasticity genes, we identified new candidate genes by a multi-step approach. First, a list was compiled of all genes of which the expression level in BXD strains correlate with the amount of OD plasticity. To narrow this list to the more promising candidates, we took its cross-section with a list of genes co-regulated with the sensitive period for OD plasticity and a list of genes associated with pathways implicated in OD plasticity. This analysis resulted in a list of 32 candidate genes. The list contained unproven, but not surprising, candidates, such as the genes for IGF-1, NCAM1, NOGO-A, the gamma2 subunit of the GABA(A receptor, acetylcholine esterase and the catalytic subunit of cAMP-dependent protein kinase A. This was indicative of the viability of our approach, but more interesting were the novel candidate genes: Akap7, Akt1, Camk2d, Cckbr, Cd44, Crim1, Ctdsp2, Dnajc5, Gnai1, Itpka, Mapk8, Nbea, Nfatc3, Nlk, Npy5r, Phf21a, Phip, Ppm1l, Ppp1r1b, Rbbp4, Slc1a3, Slit2, Socs2, Spock3, St8sia1, Zfp207. The possible role of some of these candidates is discussed in the article.

  10. Spectroscopic follow up of Kepler planet candidates

    DEFF Research Database (Denmark)

    Latham..[], D. W.; Cochran, W. D.; Marcy, G.W.

    2010-01-01

    Spectroscopic follow-up observations play a crucial role in the confirmation and characterization of transiting planet candidates identified by Kepler. The most challenging part of this work is the determination of radial velocities with a precision approaching 1 m/s in order to derive masses from...... spectroscopic orbits. The most precious resource for this work is HIRES on Keck I, to be joined by HARPS-North on the William Herschel Telescope when that new spectrometer comes on line in two years. Because a large fraction of the planet candidates are in fact stellar systems involving eclipsing stars...... and not planets, our strategy is to start with reconnaissance spectroscopy using smaller telescopes, to sort out and reject as many of the false positives as possible before going to Keck. During the first Kepler observing season in 2009, more than 100 nights of telescope time were allocated for this work, using...

  11. Attitudes of Teacher Candidates Towards Teaching Profession

    Directory of Open Access Journals (Sweden)

    Aykut Emre BOZDOĞAN

    2007-12-01

    Full Text Available The objective of this study is to determine the attitudes of teacher candidates regarding teaching profession from the point of view of different variables. This study was taken place at Ahi Ervan University Teachers’ College in 2006-2007 year of education and 181 Applied science and Social science students participated it. In order to obtain the data of the research scanning method entitled “Determination of Attitude Towards Teaching Profession” was used which was developed by Aşkar and Erden (1987 . During the analysis of the research data SPSS 12.0 program and the necessary statistical methods were used to analize the data of the research. As a result of the research it is understood that the attitudes of teacher candidates change according to sex and factor that made them to choose the department they study.

  12. Candidate Species Selection: Cultural and Photosynthetic Aspects

    Science.gov (United States)

    Mitchell, C. A.

    1982-01-01

    Cultural information is provided for a data base that will be used to select candidate crop species for a controlled ecological life support system (CELSS). Lists of food crops which will satisfy most nutritional requirements of humans and also fit within the scope of cultural restrictions that logically would apply to a closed, regenerating system were generated. Cultural and environmental conditions that will allow the most rapid production of edible biomass from candidate species in the shortest possible time are identified. Cultivars which are most productive in terms of edible biomass production by (CE) conditions, and which respond to the ever-closed approach to optimization realized by each shortened production cycle are selected. The experimental approach with lettuce was to grow the crop hydroponically in a growth chamber and to manipulate such variables as light level and duration, day/night temperature, and nutrient form and level in the solution culture.

  13. New drug candidates in tuberculosis treatment

    Directory of Open Access Journals (Sweden)

    Begüm Evranos Aksöz

    2014-12-01

    makes them quit the treatment. From these problems emerges the need for development of effective new drugs, with smaller duration of therapy, less side effects and without the problem of resistance. After a long period such as 40 years, a new drug molecule bedaquiline was approved in December 2012 by FDA while the drug was in phase II research. Bedaquiline will be used in multidrug resistant tuberculosis therapy. When the chemical structures of bedaquilline and other candidate drugs were examined, the structures such as diarylquinoline, oxazolidinone, nitroimidazole, ethylenediamine drew attention. These common structures will be directive in designing new molecules. In this review, bedaquiline and other candidate drug molecules such as sutezolide, linezolide, PA-824, delamanide, rifapentine, gatifloxacin, moxifloxacin, BTZ-043, TBA-354, CPZEN-45, DC-159a, Q201, SQ-609, SQ-641 were mentioned.

  14. Decision Analysis of Advanced Scout Helicopter Candidates

    Science.gov (United States)

    1980-01-01

    assist the ASH SSG by constructing a comprehensive ASH evaluation model utilizing multi-attribute utility assessment ( MAUA ) modeling. ~~UA is a forre...results are included as well. The output of the MAUA model is a numerical representation of the worth of each ASH candidate. These numbers are...instance of a methodology called Multi-Attribute Utility Analysis ( MAUA ). In general, MAUA is characterized by the represen- tation of outcomes in terms

  15. Optical durability testing of candidate solar mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Kennedy, C.; King, D.; Terwilliger, K.

    2000-03-24

    Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the Concentrated Solar Power (CSP) Program. Outdoor exposure testing (OET) at up to eight outdoor, worldwide exposure sites has been underway for several years. This includes collaboration under the auspices of the International Energy Agency (IEA) Solar Power and Chemical Energy Systems (SolarPACES) agreement. Outdoor sites are fully instrumented in terms of monitoring meteorological conditions and solar irradiance. Candidate materials are optically characterized prior to being subjected to exposure in real and simulated weathering environments. Optical durability is quantified by periodically re-measuring hemispherical and specular reflectance as a function of exposure time. By closely monitoring the site- and time-dependent environmental stress conditions experienced by the material samples, site-dependent loss of performance may be quantified. In addition, accelerated exposure testing (AET) of these materials in parallel under laboratory-controlled conditions may permit correlating the outdoor results with AET, and subsequently predicting service lifetimes. Test results to date for a large number of candidate solar reflector materials are presented in this report. Acronyms are defined. Based upon OET and AET results to date, conclusions can be drawn about the optical durability of the candidate reflector materials. The optical durability of thin glass, thick glass, and two metallized polymers can be characterized as excellent. The all-polymeric construction, several of the aluminized reflectors, and a metallized polymer can be characterized as having intermediate durability and require further improvement, testing and evaluation, or both.

  16. Sensitive Radio Survey of Obscured Quasar Candidates

    CERN Document Server

    Alexandroff, Rachael M; van Velzen, Sjoert; Greene, Jenny E; Strauss, Michael A

    2016-01-01

    We study the radio properties of moderately obscured quasars over a range of redshifts to understand the role of radio activity in accretion using the Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists of optically-selected obscured quasar candidates, all of which are radio-quiet, with typical radio luminosities of $\

  17. Release of uranium from candidate wasteforms

    OpenAIRE

    Collier, N.; Harrison, M.; Brogden, M,; Hanson, B

    2012-01-01

    Large volumes of depleted natural and low-enriched uranium exist in the UK waste inventory. This work reports on initial investigations of the leaching performance of candidate glass and cement encapsulation matrices containing UO3 powder as well as that of uranium oxide powders. The surface areas of UO3 powder and the monolith samples of UO3 conditioned in the glass and cement matrices were very different making leaching comparisons difficult. The results showed that for both types of monoli...

  18. Alcoholism and Alternative Splicing of Candidate Genes

    OpenAIRE

    Toshikazu Sasabe; Shoichi Ishiura

    2010-01-01

    Gene expression studies have shown that expression patterns of several genes have changed during the development of alcoholism. Gene expression is regulated not only at the level of transcription but also through alternative splicing of pre-mRNA. In this review, we discuss some of the evidence suggesting that alternative splicing of candidate genes such as DRD2 (encoding dopamine D2 receptor) may form the basis of the mechanisms underlying the pathophysiology of alcoholism. These reports sugg...

  19. ATTITUDES OF ENGLISH TEACHER CANDIDATES TOWARD ICT

    OpenAIRE

    HİSMANOGLU, Murat; HİSMANOGLU, Sibel; Hismanoglu, Murat; HISMANOGLU, Sibel

    2010-01-01

    The purpose of this study was to investigate the attitudes of English teacher candidates at formal and distance higher education contexts toward ICT and reveal whether there was a significant difference between these two groups in terms of their attitudes toward ICT. The sample of the study consisted of 175 prospective English teachers at two different higher education contexts. The participants were randomly selected among forth-year students at the ELT departments of Euopean University of L...

  20. ATTITUDES OF ENGLISH TEACHER CANDIDATES TOWARD ICT

    OpenAIRE

    Hismanoglu, Murat; HISMANOGLU, Sibel

    2011-01-01

    The purpose of this study was to investigate the attitudes of English teacher candidates at formal and distance higher education contexts toward ICT and reveal whether there was a significant difference between these two groups in terms of their attitudes toward ICT. The sample of the study consisted of 175 prospective English teachers at two different higher education contexts. The participants were randomly selected among forth-year students at the ELT departments of Euopean University of L...

  1. Searching for candidate genes for male infertility

    Institute of Scientific and Technical Information of China (English)

    B.N.Truong; E.K.Moses; J.E.Armes; D.J.Venter; H.W.G.Baker

    2003-01-01

    Aim: We describe an approach to search for candidate genes for male infertility using the two human genome databases: the public University of California at Santa Cruz (UCSC) and private Celera databases which list known and predicted gene sequences and provide related information such as gene function, tissue expression,known mutations and single nucleotide polymorphisms (SNPs). Methods and Results: To demonstrate this in silico research, the following male infertility candidate genes were selected: (1) human BOULE, mutations of which may lead to germ cell arrest at the primary spermatocyte stage, (2) mutations of casein kinase 2 alpha genes which may cause globozoospermia, (3) DMR-N9 which is possibly involved in the spermatogenic defect of myotonic dystrophy and (4) several testes expressed genes at or near the breakpoints of a balanced translocation associated with hypospermatogenesis. We indicate how information derived from the human genome databases can be used to confirm these candidate genes may be pathogenic by studying RNA expression in tissue arrays using in situ hybridization and gene sequencing. Conclusion: The paper explains the new approach to discovering genetic causes of male infertility using information about the human genome. ( Asian J Andro1 2003 Jun; 5:137-147 )

  2. Nuclear safety in EU candidate countries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    Nuclear safety in the candidate countries to the European Union is a major issue that needs to be addressed in the framework of the enlargement process. Therefore WENRA members considered it was their duty to offer their technical assistance to their Governments and the European Union Institutions. They decided to express their collective opinion on nuclear safety in those candidate countries having at least one nuclear power plant: Bulgaria, the Czech Republic, Hungary, Lithuania, Romania, Slovakia and Slovenia. The report is structured as follows: A foreword including background information, structure of the report and the methodology used, General conclusions of WENRA members reflecting their collective opinion, For each candidate country, an executive summary, a chapter on the status of the regulatory regime and regulatory body, and a chapter on the nuclear power plant safety status. Two annexes are added to address the generic safety characteristics and safety issues for RBMK and VVER plants. The report does not cover radiation protection and decommissioning issues, while safety aspects of spent fuel and radioactive waste management are only covered as regards on-site provisions. In order to produce this report, WENRA used different means: For the chapters on the regulatory regimes and regulatory bodies, experts from WENRA did the work. For the chapters on nuclear power plant safety status, experts from WENRA and from French and German technical support organisations did the work. Taking into account the contents of these chapters, WENRA has formulated its general conclusions in this report.

  3. Molecular candidates of MTV in air

    Science.gov (United States)

    Dam, Nico; Mirzaei, Mehrnoosh; van de Water, Willem

    2011-11-01

    In molecular tagging velocimetry (MTV), the molecules of a gas are used as flow tracers. These tracers can be produced at will by illumination with a laser which promotes molecules to a long- lived excited state, fuses N2 and N2 to NO, or makes molecules phosphoresce. A while later these tagged molecules can be visualized by laser-induced fluorescence, or by just watching them while they phosphoresce. Candidates for MTV in turbulence research must be arranged in structures narrower than the Kolmogorov scale, which remain narrow as time progresses, and must live longer than the Kolmogorov time. These requirements invalidate many candidates, candidates once deemed successful. They do so in various surprising manners that involve a combination of fluid flow and molecular dynamics. Rather than velocimetry in turbulence, MTV techniques offer a unique view on basic dispersion processes at the smallest scales of turbulence. In this way we have measured the spreading of clouds whose size is a few times the Kolmogorov length and the Batchelor dispersion of objects whose size is inside the inertial range.

  4. UNCOVERING THE NUCLEUS CANDIDATE FOR NGC 253

    Energy Technology Data Exchange (ETDEWEB)

    Günthardt, G. I.; Camperi, J. A. [Observatorio Astronómico, Universidad Nacional de Córdoba (Argentina); Agüero, M. P. [Observatorio Astronómico, Universidad Nacional de Córdoba, and CONICET (Argentina); Díaz, R. J.; Gomez, P. L.; Schirmer, M. [Gemini Observatory, AURA (United States); Bosch, G., E-mail: gunth@oac.uncor.edu, E-mail: camperi@oac.uncor.edu, E-mail: mpaguero@oac.uncor.edu, E-mail: rdiaz@gemini.edu, E-mail: pgomez@gemini.edu, E-mail: mschirmer@gemini.edu, E-mail: guille@fcaglp.unlp.edu.ar [Instituto de Astrofísica de La Plata (CONICET-UNLP) (Argentina)

    2015-11-15

    NGC 253 is the nearest spiral galaxy with a nuclear starburst that becomes the best candidate for studying the relationship between starburst and active galactic nucleus activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus to the point that there is no strong evidence that the galaxy harbors a supermassive black hole co-evolving with the starburst as was supposed earlier. Near-infrared (NIR) spectroscopy, especially NIR emission line analysis, could be advantageous in shedding light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis of the central structure and through the brightest infrared source. In this work, we present evidence showing that the brightest NIR and mid-infrared source in the central region, already known as radio source TH7 and so far considered just a large stellar supercluster, in fact presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. Mentioning some distinctive aspects, it is the most massive compact infrared object in the central region, located at 2.″0 of the symmetry center of the galactic bar, as measured in the K-band emission. Moreover, our data indicate that this object is surrounded by a large circumnuclear stellar disk and it is also located at the rotation center of the large molecular gas disk of NGC 253. Furthermore, a kinematic residual appears in the H{sub 2} rotation curve with a sinusoidal shape consistent with an outflow centered in the candidate nucleus position. The maximum outflow velocity is located about 14 pc from TH7, which is consistent with the radius of a shell detected around the nucleus candidate, observed at 18.3 μm (Qa) and 12.8 μm ([Ne ii]) with T-ReCS. Also, the Brγ emission line profile shows a pronounced blueshift and this emission line also has the highest equivalent width at this

  5. Half-metallicity, magnetism and electrical resistivity of Sn{sub 1−x}Mn{sub x}Te alloys in rock salt and zinc blende structures

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong [State Key Laboratory of Metastable Materials Science and Technology and College of Science, Yanshan University, Qinhuangdao 066004 (China); Physics Department, Brock University, St. Catharines, Ontario, Canada L2S 3A1 (Canada); Bose, S.K., E-mail: sbose@brocku.ca [Physics Department, Brock University, St. Catharines, Ontario, Canada L2S 3A1 (Canada); Kudrnovský, J. [Institute of Physics, Academy of the Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

    2015-02-01

    This work presents the results for the magnetic properties of the compound SnTe doped with 3d transition metal Mn from the viewpoint of potential application in spintronics. We report a systematic density-functional study of the electronic structure and magnetic properties of these ternary compounds in both rock salt and zinc blende structures. In both cases, it is the Sn-sublattice that is doped with Mn. Among the various compounds studied, we identify one as a possible half-metallic candidate: 25% Mn-doping of the Sn-sublattice in the rock salt structure. Others are either magnetic semiconductors or metals. Exchange interaction between the Mn atoms is discussed and results for resistivities for various compositions in the two structures are compared. For low Mn concentration, the zero temperature ground state of the compound is found to be semiconducting and the Mn–Mn exchange interactions are dominantly antiferromagnetic. The weakly ferromagnetic interaction and ordering found in experiments is shown to be ‘carrier induced’. It is shown that ferromagnetic interactions between the Mn atoms are caused by the presence of ‘holes’. Another likely cause is the presence of extra Te atoms in interstitial locations, which seems to suppress Mn–Mn antiferromagnetic interactions. This is supported by the earlier experimental observation that a weak ferromagnetism occurs in these alloys for low Mn concentration only if the samples are subjected to additional Te-flux. - Highlights: • We study electronic structure and magnetic properties of Mn-doped semiconductor SnTe. • We find one antiferromagnetic half-metallic case: Sn{sub 3}Mn{sub 1}Te{sub 4} in rock salt structure. • We show that the presence of ‘holes’ may turn antiferromagnetic Mn–Mn interactions to ferromagnetic. • Results are compared with available experimental data.

  6. ARIEL: an ESA M4 mission candidate

    Science.gov (United States)

    Puig, L.; Pilbratt, G. L.; Heske, A.; Escudero Sanz, I.; Crouzet, P.-E.

    2016-07-01

    The Atmospheric Remote sensing Infrared Exoplanet Large survey (ARIEL) mission is an M-class mission candidate within the science program Cosmic Vision of the European Space Agency (ESA). It was selected in June 2015 as one of three candidates to enter an assessment phase (phase 0/A). This process involves the definition of science and mission requirements as well as a preliminary model payload, and an internal Concurrent Design Facility (CDF) study providing the input to parallel industrial studies (in progress since 2016). After this process, the three candidates will be reviewed and in mid-2017 one of them will be selected as the M4 mission for launch in 2026. ARIEL is a survey-type mission dedicated to the characterisation of exoplanetary atmospheres. Using the differential technique of transit spectroscopy, ARIEL will obtain transmission and/or emission spectra of the atmospheres of a large and diverse sample of known exoplanets (~500) covering a wide range of masses, densities, equilibrium temperatures, orbital properties and host-star characteristics. This will include hot Jupiters to warm Super-Earths, orbiting M5 to F0 stars. This paper describes critical requirements, and reports on the results of the Concurrent Design Facility (CDF) study that was conducted in June / July 2015, providing a description of the resulting spacecraft design. It will employ a 0.7 m x 1.1 m off-axis three mirror telescope, feeding four photometric channels in the VNIR range (0.5-1.95 μm) and an IR spectrometer covering 1.95-7.8 μm.

  7. Blend Analysis of HATNet Transit Candidates

    Directory of Open Access Journals (Sweden)

    Bakos G.Á.

    2011-02-01

    Full Text Available Candidate transiting planet systems discovered by wide-field groundbased surveys must go through an intensive follow-up procedure to distinguish the true transiting planets from the much more common false positives. Especially pernicious are configurations of three or more stars which produce radial velocity and light curves that are similar to those of single stars transited by a planet. In this contribution we describe the methods used by the HATNet team to reject these blends, giving a few illustrative examples.

  8. Avalanche Effect in Improperly Initialized CAESAR Candidates

    Directory of Open Access Journals (Sweden)

    Martin Ukrop

    2016-12-01

    Full Text Available Cryptoprimitives rely on thorough theoretical background, but often lack basic usability features making them prone to unintentional misuse by developers. We argue that this is true even for the state-of-the-art designs. Analyzing 52 candidates of the current CAESAR competition has shown none of them have an avalanche effect in authentication tag strong enough to work properly when partially misconfigured. Although not directly decreasing their security profile, this hints at their security usability being less than perfect. Paper details available at crcs.cz/papers/memics2016

  9. Alcoholism and alternative splicing of candidate genes.

    Science.gov (United States)

    Sasabe, Toshikazu; Ishiura, Shoichi

    2010-04-01

    Gene expression studies have shown that expression patterns of several genes have changed during the development of alcoholism. Gene expression is regulated not only at the level of transcription but also through alternative splicing of pre-mRNA. In this review, we discuss some of the evidence suggesting that alternative splicing of candidate genes such as DRD2 (encoding dopamine D2 receptor) may form the basis of the mechanisms underlying the pathophysiology of alcoholism. These reports suggest that aberrant expression of splice variants affects alcohol sensitivities, and alcohol consumption also regulates alternative splicing. Thus, investigations of alternative splicing are essential for understanding the molecular events underlying the development of alcoholism.

  10. Microlensing Binaries with Candidate Brown Dwarf Companions

    DEFF Research Database (Denmark)

    Shin, I.-G; Han, C.; Gould, A.

    2012-01-01

    Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation histories. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing...... masses of the brown dwarf companions are 0.02 ± 0.01 M⊙ and 0.019 ± 0.002 M⊙ for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low-mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events...

  11. Reducing stigma and discrimination: Candidate interventions

    Directory of Open Access Journals (Sweden)

    Kassam Aliya

    2008-04-01

    Full Text Available Abstract This paper proposes that stigma in relation to people with mental illness can be understood as a combination of problems of knowledge (ignorance, attitudes (prejudice and behaviour (discrimination. From a literature review, a series of candidate interventions are identified which may be effective in reducing stigmatisation and discrimination at the following levels: individuals with mental illness and their family members; the workplace; and local, national and international. The strongest evidence for effective interventions at present is for (i direct social contact with people with mental illness at the individual level, and (ii social marketing at the population level.

  12. Geoscience Training for NASA Astronaut Candidates

    Science.gov (United States)

    Young, K. E.; Evans, C. A.; Bleacher, J. E.; Graff, T. G.; Zeigler, R.

    2017-01-01

    After being selected to the astronaut office, crewmembers go through an initial two year training flow, astronaut candidacy, where they learn the basic skills necessary for spaceflight. While the bulk of astronaut candidate training currently centers on the multiple subjects required for ISS operations (EVA skills, Russian language, ISS systems, etc.), training also includes geoscience training designed to train crewmembers in Earth observations, teach astronauts about other planetary systems, and provide field training designed to investigate field operations and boost team skills. This training goes back to Apollo training and has evolved to support ISS operations and future exploration missions.

  13. Top Zika Vaccine Candidate Moves Closer to Field Testing

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_161274.html Top Zika Vaccine Candidate Moves Closer to Field Testing DNA- ... MONDAY, Oct. 3, 2016 (HealthDay News) -- The leading Zika vaccine candidate should be ready for field testing ...

  14. Phenol sulfotransferases: Candidate genes for Batten disease

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, T.P.; Probst, P.; Obermoeller, R.D. [M.D. Anderson Cancer Center, Houston, TX (United States)] [and others

    1995-06-05

    Batten disease (juvenile-onset neuronal ceroid lipofuscinosis; JNCL) is an autosomal recessive neurodegenerative disorder, characterized by the cytosomal accumulation of autofluorescent protolipopigments in neurons and other cell types. The Batten disease gene (CLN3) has not yet been identified, but has been mapped to a small region of human chromosome area 16p12.1-p11.2. We recently reported the fortuitous discovery that the cytosolic phenol sulfotransferase gene (STP) is located within this same interval of chromosome 16p. Since phenol sulfotransferase is expressed in neurons, can sulfate lipophilic phenolic compounds, and is mapped near CLN3, STP is considered as a candidate gene for Batten disease. YAC and cosmid cloning results have further substantiated the close proximity of STP and a highly related sulfotransferase (STM), encoding the catecholamine-preferring enzyme, to the CLN3 region of chromosome 16p. In this report, we summarize some of the recent progress in the identification of two phenol sulfotransferase genes (STP and STM) as positional candidate genes for Batten disease. 42 refs., 1 tab.

  15. Pulsar Candidates Toward Fermi Unassociated Sources

    CERN Document Server

    Frail, D A; Jagannathan, P; Intema, H T

    2016-01-01

    We report on a search for steep spectrum radio sources within the 95% confidence error ellipses of the Fermi unassociated sources from the Large Array Telescope (LAT). Using existing catalogs and the newly released GMRT all-sky survey at 150 MHz we identify compact radio sources that are bright at MHz frequencies but faint or absent at GHz frequencies. Such steep spectrum radio sources are rare and constitute a sample of pulsar candidates, selected independently of period, dispersion measure, interstellar scattering and orbital parameters. We find point-like, steep spectrum candidates toward 11 Fermi sources. Based on the gamma-ray/radio positional coincidence, the rarity of such radio sources, and the properties of the 3FGL sources themselves, we argue that many of these sources could be pulsars. They may have been missed by previous radio periodicity searches due to interstellar propagation effects or because they lie in an unusually tight binary. If this hypothesis is correct, then renewed gamma-ray and ra...

  16. Nonclinical Development of BCG Replacement Vaccine Candidates

    Directory of Open Access Journals (Sweden)

    Bernd Eisele

    2013-04-01

    Full Text Available The failure of current Mycobacterium bovis bacille Calmette–Guérin (BCG vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines.

  17. Theoretical Comparison Between Candidates for Dark Matter

    Science.gov (United States)

    McKeough, James; Hira, Ajit; Valdez, Alexandra

    2017-01-01

    Since the generally-accepted view among astrophysicists is that the matter component of the universe is mostly dark matter, the search for dark matter particles continues unabated. The Large Underground Xenon (LUX) improvements, aided by advanced computer simulations at the U.S. Department of Energy's Lawrence Berkeley National Laboratory's (Berkeley Lab) National Energy Research Scientific Computing Center (NERSC) and Brown University's Center for Computation and Visualization (CCV), can potentially eliminate some particle models of dark matter. Generally, the proposed candidates can be put in three categories: baryonic dark matter, hot dark matter, and cold dark matter. The Lightest Supersymmetric Particle(LSP) of supersymmetric models is a dark matter candidate, and is classified as a Weakly Interacting Massive Particle (WIMP). Similar to the cosmic microwave background radiation left over from the Big Bang, there is a background of low-energy neutrinos in our Universe. According to some researchers, these may be the explanation for the dark matter. One advantage of the Neutrino Model is that they are known to exist. Dark matter made from neutrinos is termed ``hot dark matter''. We formulate a novel empirical function for the average density profile of cosmic voids, identified via the watershed technique in ΛCDM N-body simulations. This function adequately treats both void size and redshift, and describes the scale radius and the central density of voids. We started with a five-parameter model. Our research is mainly on LSP and Neutrino models.

  18. Vaccine candidates for leishmaniasis: a review.

    Science.gov (United States)

    Nagill, Rajeev; Kaur, Sukhbir

    2011-10-01

    Leishmaniasis is a diverse group of clinical syndromes caused by protozoan parasites of the genus Leishmania. The clinical manifestation of the disease varies from self-limiting cutaneous lesions to progressive visceral disease. It is estimated that 350 million people are at risk in 88 countries, with a global incidence of 1-1.5 million cases of cutaneous and 500,000 cases of visceral leishmaniasis. The key control measures mainly rely on early case detection and chemotherapy which has been hampered by the toxicity of drugs, side-effects and by the emergence of drug resistance in parasites. Control of reservoir host and vector is difficult due to operational difficulties and frequent relapses in the host. Therefore, the development of effective and affordable vaccine against leishmaniasis is highly desirable. Although considerable progress has been made over the last decade in understanding immune mechanisms underlying potential candidate antigens, including killed, live attenuated parasites, crude parasites, pure or recombinant Leishmania proteins or DNA encoding leishmanial proteins, as well as immunomodulators from sand fly saliva, very few candidate vaccines have progressed beyond the experimental stage. As such there is no vaccine against any form of human leishmaniasis. In recent years, however, much interest has been stimulated towards vaccination against leishmaniasis focused mainly on cutaneous leishmaniasis with fewer attempts against visceral leishmaniasis.

  19. Serological profile of candidates for corneal donation

    Directory of Open Access Journals (Sweden)

    Adroaldo Lunardelli

    2014-10-01

    Full Text Available Objetive: The purpose of this study is to map the serological profile of candidates to corneal donation at Irmandade Santa Casa de Misericórdia de Porto Alegre, identifying the percentage of disposal by serology and the marker involved. Methods: There have been analised – retrospectively – the results of serology of all corneal donors, made between the period of 1st january 2006 and 31st december 2012. Data analised were related to age, gender and the results of serology pertinent to viral markers (HBsAg, anti-HBc, anti-HCV and anti-HIV, these, determined by immunosorbent tests (ELISA. Results: In the period of the study, there were 2476 corneal donors at the institution, with a major incidence on the male gender, on an average of 58.7 years old. 23% of retention because of serological unfitness was also identified, that is, 570 samples were non-negative to any of the used tests. The marker anti- HBc was the most prevalent on the studied population, followed by the Hepatitis C virus (HCV and by the Human Immunodeficiency Virus (HIV. Conclusion: From the data found through this study, it is essential to have the participation of an efficient service on the serological evaluation of the candidates to corneal donation, once the security of the receptor must be taken into consideration in a population of donors with 23% of unfitness prevalence, in which the most prevalent marker is the one of Hepatits B.

  20. Elemental Abundances of Solar Sibling Candidates

    Science.gov (United States)

    Ramírez, I.; Bajkova, A. T.; Bobylev, V. V.; Roederer, I. U.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J.; Wittenmyer, R. A.

    2014-06-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high-resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD 162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying as many elements as possible but instead from identifying and carefully measuring the abundances of those elements that show large star-to-star scatter at a given metallicity. Future searches employing data products from ongoing massive astrometric and spectroscopic surveys can be optimized by acknowledging this fact.

  1. Elemental Abundances of Solar Sibling Candidates

    CERN Document Server

    Ramirez, I; Bobylev, V V; Roederer, I U; Lambert, D L; Endl, M; Cochran, W D; MacQueen, P J; Wittenmyer, R A

    2014-01-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying a...

  2. Advanced Vaccine Candidates for Lassa Fever

    Directory of Open Access Journals (Sweden)

    Igor S. Lukashevich

    2012-10-01

    Full Text Available Lassa virus (LASV is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF. LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.

  3. Advanced vaccine candidates for Lassa fever.

    Science.gov (United States)

    Lukashevich, Igor S

    2012-10-29

    Lassa virus (LASV) is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF). LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.

  4. Uncovering the nucleus candidate for NGC 253

    CERN Document Server

    Günthardt, G I; Camperi, J A; Díaz, R J; Gomez, P L; Bosch, G; Schirmer, M

    2015-01-01

    NGC253 is the nearest spiral galaxy with a nuclear starburst which becomes the best candidate to study the relationship between starburst and AGN activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus. The near infrared spectroscopy could be advantageous in order to shed light on the true nucleus identity. Using Flamingos-2 at Gemini South we have taken deep K-band spectra along the major axis and through the brightest infrared source. We present evidence showing that the brightest near infrared and mid infrared source in the central region, already known as radio source TH7 and so far considered just a stellar supercluster, in fact, presents various symptoms of a genuine galactic nucleus. Therefore, it should be considered a valid nucleus candidate. It is the most massive compact infrared object in the central region, located at 2.0" of the symmetry center of the galactic bar. Moreover, our data indicate that this object i...

  5. Elemental abundances of solar sibling candidates

    Energy Technology Data Exchange (ETDEWEB)

    Ramírez, I.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J. [McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, Texas 78712-1205 (United States); Bajkova, A. T.; Bobylev, V. V. [Central (Pulkovo) Astronomical Observatory of RAS, 65/1, Pulkovskoye Chaussee, St. Petersburg 196140 (Russian Federation); Roederer, I. U. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Wittenmyer, R. A. [School of Physics, UNSW Australia, Sydney 2052 (Australia)

    2014-06-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high-resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD 162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying as many elements as possible but instead from identifying and carefully measuring the abundances of those elements that show large star-to-star scatter at a given metallicity. Future searches employing data products from ongoing massive astrometric and spectroscopic surveys can be optimized by acknowledging this fact.

  6. Political Candidate Campaign Advertising: A Selected Review of the Literature.

    Science.gov (United States)

    Hellweg, Susan A.

    This paper provides a selected review of political candidate campaign advertising studies from the political science, mass communication, advertising, and political communication literature. The paper examines the literature in terms of research pertaining to (1) candidate advertising content (commercials for male versus female candidates and for…

  7. Views on Values Education: From Teacher Candidates to Experienced Teachers

    Science.gov (United States)

    Iscan, Canay Demirhan

    2015-01-01

    This study aimed to identify the views of experienced class teachers and class teacher candidates on values education. It conducted standard open-ended interviews with experienced class teachers and teacher candidates. The study group comprised 9 experienced class teachers from different socio-economic levels and 9 teacher candidates with…

  8. Encouraging Discussion between Teacher Candidates and Families with Exceptional Children

    Science.gov (United States)

    Williams, Emily

    2012-01-01

    The Families as Faculty experience assists universities to better prepare candidates for service as classroom teachers. Upon entering their practica and student teaching, many teacher candidates have had no to limited contact with exceptional students. Often candidates are unaware of the realities of having a student with disabilities in their…

  9. Mirror Images: Teacher Candidates' Perceptions of Disposition Development

    Science.gov (United States)

    Bercaw, Lynne A.; Summers, Deborah G.; Colby, Susan A.; Payne, Maggie

    2012-01-01

    The complexity of disposition development for teacher candidates continues to be discussed and debated in teacher education. This study compares two programs and the different ways each approaches the disposition development of their respective candidates. More than 200 candidates from two institutions were surveyed on how and where they perceived…

  10. Identity Functions and Empathetic Tendencies of Teacher Candidates

    Science.gov (United States)

    Ay, Alpaslan; Kadi, Aysegul

    2016-01-01

    Objective of this research is to investigate identity functions and empathetic tendencies of teacher candidates. Sample consists of 232 teacher candidates in social studies teacher education. Survey model is preferred to investigate the difference between identity functions and empathetic tendencies of teacher candidates. And also correlational…

  11. Production of EV71 vaccine candidates.

    Science.gov (United States)

    Chong, Pele; Hsieh, Shih-Yang; Liu, Chia-Chyi; Chou, Ai-Hsiang; Chang, Jui-Yuan; Wu, Suh-Chin; Liu, Shih-Jen; Chow, Yen-Hung; Su, Ih-Jen; Klein, Michel

    2012-12-01

    Enterovirus 71 (EV71) is now recognized as an emerging neurotropic virus in Asia and with Coxsackie virus (CV) it is the other major causative agent of hand-foot-mouth diseases (HFMD). Effective medications and/or prophylactic vaccines against HFMD are urgently needed. From a scientific (the feasibility of bioprocess, immunological responses and potency in animal challenge model) and business development (cost of goods) points of view, we in this review address and discuss the pros and cons of different EV71 vaccine candidates that have been produced and evaluated in animal models. Epitope-based synthetic peptide vaccine candidates containing residues 211-225 of VP1 formulated with Freund's adjuvant (CFA/IFA) elicited low EV71 virus neutralizing antibody responses, but were protective in the suckling mouse challenge model. Among recombinant EV71 subunits (rVP1, rVP2 and rVP3) expressed in E. coli, purified and formulated with CFA/IFA, only VP1 elicited mouse antibody responses with measurable EV71-specific virus neutralization titers. Immunization of mice with either a DNA plasmid containing VP1 gene or VP1 expressed in Salmonella typhimurium also generated neutralizing antibody responses and protected animals against a live EV71 challenge. Recombinant EV71 virus-like particles (rVLP) produced from baculovirus formulated either with CFA/IFA or alum elicited good virus neutralization titers in both mice and non-human primates, and were found to be protective in the suckling mouse EV71 challenge model. Synthetic peptides or recombinant EV71 subunit vaccines (rVP1 and rVLP) formulated in alum were found to be poorly immunogenic in rabbits. Only formalin-inactivated (FI) EV71 virions formulated in alum elicited cross-neutralizing antibodies against different EV71 genotypes in mice, rabbits and non-human primates but induced weak neutralizing responses against CAV16. From a regulatory, economic and market acceptability standpoint, FI-EV71 virion vaccines are the most

  12. A direct molecular link between the autism candidate gene RORa and the schizophrenia candidate MIR137

    Science.gov (United States)

    Devanna, Paolo; Vernes, Sonja C.

    2014-02-01

    Retinoic acid-related orphan receptor alpha gene (RORa) and the microRNA MIR137 have both recently been identified as novel candidate genes for neuropsychiatric disorders. RORa encodes a ligand-dependent orphan nuclear receptor that acts as a transcriptional regulator and miR-137 is a brain enriched small non-coding RNA that interacts with gene transcripts to control protein levels. Given the mounting evidence for RORa in autism spectrum disorders (ASD) and MIR137 in schizophrenia and ASD, we investigated if there was a functional biological relationship between these two genes. Herein, we demonstrate that miR-137 targets the 3'UTR of RORa in a site specific manner. We also provide further support for MIR137 as an autism candidate by showing that a large number of previously implicated autism genes are also putatively targeted by miR-137. This work supports the role of MIR137 as an ASD candidate and demonstrates a direct biological link between these previously unrelated autism candidate genes.

  13. ELECTIONS PENSION FUND CANDIDATE NR 4

    CERN Document Server

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : MYERS First Name : Stephen I have been at CERN since 1972, and was elected member of the Governing Board for the first time in 1998. The Governing Board then nominated me to the Investments Committee where I have been a member since the beginning of 1999. Since then I have actively participated in redefining and transforming the investment portfolio in order to improve the overall return and where possible reduce the risk. The portfolio has recently been greatly improved and now allows much simpler more transparent monitoring of our investment. I have also actively participated and hopefully made useful contributions in discussions conc...

  14. ELECTIONS PENSION FUND 4th candidate

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : MYERS First Name : Stephen I have been at CERN since 1972, and was elected member of the Governing Board for the first time in 1998. The Governing Board then nominated me to the Investments Committee where I have been a member since the beginning of 1999. Since then I have actively participated in redefining and transforming the investment portfolio in order to improve the overall return and where possible reduce the risk. The portfolio has recently been greatly improved and now allows much simpler more transparent monitoring of our investment. I have also actively participated and hopefully made useful contributions in discussions conc...

  15. Alcoholism and Alternative Splicing of Candidate Genes

    Directory of Open Access Journals (Sweden)

    Toshikazu Sasabe

    2010-03-01

    Full Text Available Gene expression studies have shown that expression patterns of several genes have changed during the development of alcoholism. Gene expression is regulated not only at the level of transcription but also through alternative splicing of pre-mRNA. In this review, we discuss some of the evidence suggesting that alternative splicing of candidate genes such as DRD2 (encoding dopamine D2 receptor may form the basis of the mechanisms underlying the pathophysiology of alcoholism. These reports suggest that aberrant expression of splice variants affects alcohol sensitivities, and alcohol consumption also regulates alternative splicing. Thus, investigations of alternative splicing are essential for understanding the molecular events underlying the development of alcoholism.

  16. Halopentacenes: Promising Candidates for Organic Semiconductors

    Institute of Scientific and Technical Information of China (English)

    DU Gong-He; REN Zhao-Yu; GUO Ping; ZHENG Ji-Ming

    2009-01-01

    We introduce polar substituents such as F, Cl, Br into pentacene to enhance the dissolubility in common organic solvents while retaining the high charge-carrier mobilities of pentacene. Geometric structures, dipole moments,frontier molecule orbits, ionization potentials and electron affinities, as well as reorganization energies of those molecules, and of pentacene for comparison, are successively calculated by density functional theory. The results indicate that halopentacenes have rather small reorganization energies (< 0.2 eV), and when the substituents are in position 2 or positions 2 and 9, they are polarity molecules. Thus we conjecture that they can easily be dissolved in common organic solvents, and are promising candidates for organic semiconductors.

  17. ELECTIONS PENSION FUND CANDIDATE NR 3

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : HAUVILLER First Name : Claude Dear colleague of CERN and ESO, For the first time, I am standing and requesting your support to become a member of the Governing Board of our Pension Fund. CERN staff member since 1974, I have already carried elective mandates: I have been Delegate to the Staff Council and Member of the Senior Staff Consultative Committee (the Nine). For the majority of us, our Pension Fund is our only social provident scheme and source of retirement income; I believe I can usefully contribute to its successful management and help ensure its balance. Our Fund reaches its majority: soon, there will be more beneficiaries tha...

  18. ELECTIONS PENSION FUND 3rd candidate

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : Hauviller First Name : Claude Dear colleague of CERN and ESO, For the first time, I am standing and requesting your support to become a member of the Governing Board of our Pension Fund. CERN staff member since 1974, I have already carried elective mandates: I have been Delegate to the Staff Council and Member of the Senior Staff Consultative Committee (the Nine). For the majority of us, our Pension Fund is our only social provident scheme and source of retirement income; I believe I can usefully contribute to its successful management and help ensure its balance. Our Fund reaches its majority: soon, there will be more beneficiaries tha...

  19. New potential AChE inhibitor candidates.

    Science.gov (United States)

    de Paula, A A N; Martins, J B L; dos Santos, M L; Nascente, L de C; Romeiro, L A S; Areas, T F M A; Vieira, K S T; Gambôa, N F; Castro, N G; Gargano, R

    2009-09-01

    We have theoretically studied new potential candidates of acetylcholinesterase (AChE) inhibitors designed from cardanol, a non-isoprenoid phenolic lipid of cashew Anacardium occidentale nut-shell liquid. The electronic structure calculations of fifteen molecule derivatives from cardanol were performed using B3LYP level with 6-31G, 6-31G(d), and 6-311+G(2d,p) basis functions. For this study we used the following groups: methyl, acetyl, N,N-dimethylcarbamoyl, N,N-dimethylamine, N,N-diethylamine, piperidine, pyrrolidine, and N,N-methylbenzylamine. Among the proposed compounds we identified that the structures with substitution by N,N-dimethycarbamoyl, N,N-dimethylamine, and pyrrolidine groups were better correlated to rivastigmine, and represent possible AChE inhibitors against Alzheimer disease.

  20. Hypervelocity Star Candidates in the SEGUE G & K Dwarf Sample

    CERN Document Server

    Palladino, Lauren E; Holley-Bockelmann, Kelly; Prieto, Carlos Allende; Beers, Timothy C; Lee, Young Sun; Schneider, Donald P

    2013-01-01

    We identify 13 candidate hypervelocity stars from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) G and K dwarf samples. Previous searches for hypervelocity stars have only focused on large radial velocities; in this study we also use proper motions to select the candidates. We determine the hypervelocity likelihood of each candidate, considering the significant errors often associated with high proper motion stars via Monte Carlo simulations. We find that more than half of the candidates exceed their escape velocities with at least 90% probability. All of our candidates also have less than a 60% chance of being a high velocity fluke within the SEGUE sample. Based on orbits calculated using the observed 6-d positions and velocities, few, if any, of these candidates originate from the Galactic Center. If these candidates are truly hypervelocity stars, they were not ejected by interactions with the Milky Way's supermassive black hole. This calls for a more serious examination of alternati...

  1. SHIELD: Observations of Three Candidate Interacting Systems

    Science.gov (United States)

    Ruvolo, Elizabeth; Miazzo, Masao; Cannon, John M.; McNichols, Andrew; Teich, Yaron; Adams, Elizabeth A.; Giovanelli, Riccardo; Haynes, Martha P.; McQuinn, Kristen B.; Salzer, John Joseph; Skillman, Evan D.; Dolphin, Andrew E.; Elson, Edward C.; Haurberg, Nathalie C.; Huang, Shan; Janowiecki, Steven; Jozsa, Gyula; Leisman, Luke; Ott, Juergen; Papastergis, Emmanouil; Rhode, Katherine L.; Saintonge, Amelie; Van Sistine, Angela; Warren, Steven R.

    2017-01-01

    Abstract:The “Survey of HI in Extremely Low-mass Dwarfs” (SHIELD) is a multiwavelength study of local volume low-mass galaxies. Using the now-complete Arecibo Legacy Fast ALFA (ALFALFA) source catalog, 82 systems are identified that meet distance, line width, and HI flux criteria for being gas-rich, low-mass galaxies. These systems harbor neutral gas reservoirs smaller than 3x10^7 M_sun, thus populating the faint end of the HI mass function with statistical confidence for the first time. In a companion poster, we present new Karl G. Jansky Very Large Array D-configuration HI spectral line observations of 32 previously unobserved galaxies. Three galaxies in that study have been discovered to lie in close angular proximity to more massive galaxies. Here we present VLA HI imaging of these candidate interacting systems. We compare the neutral gas morphology and kinematics with optical images from SDSS. We discuss the frequency of low-mass galaxies undergoing tidal interaction in the complete SHIELD sample.Support for this work was provided by NSF grant 1211683 to JMC at Macalester College.

  2. Galactic worms. I - Catalog of worm candidates

    Science.gov (United States)

    Koo, Bon-Chul; Heiles, Carl; Reach, William T.

    1992-01-01

    A catalog of candidates for the Galactic worms that are possibly the walls surrounding the superbubbles is compiled; 118 isolated structures that appear both in H I and in IR (60 and 100 microns). Fifty-two are possibly associated with H II regions. It is found that the 100-micron emissivity increases systematically toward the Galactic interior, which is consistent with the increase of the general interstellar radiation field. The 100-micron emissivity of the structures associated with the H II regions is larger than that of the structures without associated H II regions. The 60-100-micron ratio is large, 0.28 +/- 0.03, which may indicate that the grains associated with the atomic gas have a relatively large population of small grains. Thirty-five structures appear in the 408-MHz continuum. The IR and the radio continuum properties suggest that the 408-MHz continuum emission in those structures is very likely thermal. The implications of these results on the ionization of gas far from the Galactic plane are discussed.

  3. ELECTIONS PENSION FUND CANDIDATE NO 1

    CERN Document Server

    2000-01-01

    This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name: MAURINFirst Name:Guy I have been a member of the personnel since 1967 and as early as 1972 I was involved, in my capacity as President of the Staff Association, in the improvement of the Pension Fund benefits. As for most of us the Pension Fund is the only social provident scheme to which we belong, it is important to ensure that it is well managed and in balance. As a member of the Governing Board since 1974 and Vice-Chairman of this Board since 1977, I have continued to pursue these objectives.One of the main responsibilities of the Governing Board is our asset investment policy. The Investment Committee, of which I am Chairman, must have an overall view of the management of our 4 billion Swiss francs and seek the best yield with minimum risk. The investment structure must continuously be adapted...

  4. ELECTIONS PENSION FUND CANDIDATE NO 2

    CERN Multimedia

    2000-01-01

    This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund.   Candidate: Name: RANJARDFirst Name: Florence Having been a member of the Governing Board of the Pension Fund since 1983 as Guy Maurin’s alternate, I am standing for a further 3-year term of office. Over the past few years work has concentrated essentially on following items: Monitoring of the work of the fund managers and their performances. The three-yearly study of the Fund’s actuarial situation. The pension guarantees ­ second phase. The Fund is approaching its maturity: the level of benefits exceeds contributions. In this context it has to strike a suitable balance between management of the risk from a dynamic investment policy, while a prudent policy avoiding any significant loss of its capital. These will be my concerns within the Governing Board of the Pension Fund if you...

  5. Photon defects in noncommutative standard model candidates

    Energy Technology Data Exchange (ETDEWEB)

    Abel, S.A.; Khoze, V.V. [Durham Univ. (United Kingdom). Center for Particle Theory; Jaeckel, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2006-06-15

    Restrictions imposed by gauge invariance in noncommutative spaces together with the effects of ultraviolet/infrared mixing lead to strong constraints on possible candidates for a noncommutative extension of the Standard Model. We study a general class of noncommutative models consistent with these restrictions. Specifically we consider models based upon a gauge theory with the gauge group U(N{sub 1}) x U(N{sub 2}) x.. x U(N{sub m}) coupled to matter fields transforming in the (anti)-fundamental, bi-fundamental and adjoint representations. We pay particular attention to overall trace-U(1) factors of the gauge group which are affected by the ultraviolet/infrared mixing. Typically, these trace-U(1) gauge fields do not decouple sufficiently fast in the infrared, and lead to sizable Lorentz symmetry violating effects in the low-energy effective theory. In a 4-dimensional theory on a continuous space-time making these effects unobservable would require making the effects of noncommutativity tiny, M{sub NC} >> M{sub P}. This severely limits the phenomenological prospects of such models. However, adding additional universal extra dimensions the trace-U(1) factors decouple with a power law and the constraint on the noncommutativity scale is weakened considerably. Finally, we briefly mention some interesting properties of the photon that could arise if the noncommutative theory is modified at a high energy scale. (Orig.)

  6. Virus-like particles as nanovaccine candidates

    Science.gov (United States)

    Guillen, G.; Aguilar, J. C.; Dueñas, S.; Hermida, L.; Iglesias, E.; Penton, E.; Lobaina, Y.; Lopez, M.; Mussachio, A.; Falcon, V.; Alvarez, L.; Martinez, G.; Gil, L.; Valdes, I.; Izquierdo, A.; Lazo, L.; Marcos, E.; Guzman, G.; Muzio, V.; Herrera, L.

    2013-03-01

    The existing vaccines are mainly limited to the microorganisms we are able to culture and produce and/or to those whose killing is mediated by humoral response (antibody mediated). It has been more difficult to develop vaccines capable of inducing a functional cellular response needed to prevent or cure chronic diseases. New strategies should be taken into account in the improvement of cell-based immune responses in order to prevent and control the infections and eventually clear the virus. Preclinical and clinical results with vaccine candidates developed as a vaccine platform based on virus-like particles (VLPs) evidenced their ability to stimulate mucosal as well as systemic immunity. Particles based on envelope, membrane or nucleocapsid microbial proteins induce a strong immune response after nasal or parenteral administration in mice, non-human primates and humans. In addition, the immune response obtained was modulated in a Th1 sense. The VLPs were also able to immunoenhance the humoral and cellular immune responses against several viral pathogens. Studies in animals and humans with nasal and systemic formulations evidenced that it is possible to induce functional immune response against HBV, HCV, HIV and dengue virus. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology, 30 October - 2 November 2012, Ha Long, Vietnam.

  7. ELECTIONS PENSION FUND 5th candidate

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate :  Name : Sonnemann  First Name : Florian Since my arrival at CERN in 1997 I have worked in the accelerator and administrative sectors. I have recently been elected as member of the Staff Council and of the Executive Committee of the Staff Association in which I am actively following matters concerning the Pension Fund. My candidature for the Governing Board of the CERN Pension Fund is mainly motivated to add my part in ensuring a solid financial situation of the Pension Fund. The Pension Fund is our only social security system. I wish to play a role in ensuring that the pensions will remain a secure revenue for all staff membe...

  8. ELECTIONS PENSION FUND CANDIDATE NR 5

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate :  Name : Sonnemann  First Name : Florian Since my arrival at CERN in 1997 I have worked in the accelerator and administrative sectors. I have recently been elected as member of the Staff Council and of the Executive Committee of the Staff Association in which I am actively following matters concerning the Pension Fund. My candidature for the Governing Board of the CERN Pension Fund is mainly motivated to add my part in ensuring a solid financial situation of the Pension Fund. The Pension Fund is our only social security system. I wish to play a role in ensuring that the pensions will remain a secure revenue for all staff membe...

  9. ELECTIONS PENSION FUND CANDIDATE NR 1

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : CHIAVERI First Name : Enrico I have been a CERN staff member since 1973 and have always been interested in our working conditions. As a member of the Executive Committee of the Staff Association I participated from 1980 to 1984 in the Working Group on Pensions mandated by the CERN Council. This commitment led to my becoming a member of the Governing Board of the Pension Fund in 1983, since when I have taken an active part in various commissions and working groups (Real Estate Asset Management Committee, Working Group on Actuarial Matters etc.); in so doing I have gained a thorough knowledge of different areas of the Pension Fund. Since ...

  10. Algal Lectins as Potential HIV Microbicide Candidates

    Directory of Open Access Journals (Sweden)

    Dominique Schols

    2012-07-01

    Full Text Available The development and use of topical microbicides potentially offers an additional strategy to reduce the spread of the Human Immunodeficiency Virus (HIV. Carbohydrate-binding agents (CBAs that show specificity for high mannose carbohydrates on the surface of the heavily glycosylated envelope of HIV are endowed with potent anti-HIV activity. In fact, a number of algal lectins such as cyanovirin-N, microvirin, microcystis viridis lectin, scytovirin, Oscillatoria agardhii agglutinin and griffithsin are considered as potential microbicide candidates to prevent the sexual transmission of HIV through topical applications. They not only inhibit infection of cells by cell-free virus but they can also efficiently prevent virus transmission from virus-infected cells to uninfected CD4+ target T-lymphocytes and DC-SIGN-directed capture of HIV-1 and transmission to CD4+ T lymphocytes. This review focuses on the structural properties and carbohydrate specificity of these algal lectins, their antiviral activity against HIV and several other enveloped viruses, their safety profile and viral resistance patterns.

  11. Cerebrospinal fluid biomarker candidates for parkinsonian disorders

    Directory of Open Access Journals (Sweden)

    Radu eConstantinescu

    2013-01-01

    Full Text Available The parkinsonian disorders are a large group of neurodegenerative diseases including idiopathic Parkinson's disease (PD and atypical parkinsonian disorders, such as multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, and dementia with Lewy bodies. The etiology of these disorders is not known although it is considered to be a combination of genetic and environmental factors. One of the greatest obstacles for developing efficacious disease-modifying treatment strategies is the lack of biomarkers. Reliable biomarkers are needed for early and accurate diagnosis, to measure disease progression and response to therapy. In this review several of the most promising cerebrospinal biomarker candidates are discussed. Alpha synuclein seems to be intimately involved in the pathogenesis of synucleinopathies and its levels can be measured in the cerebrospinal fluid and in plasma. In a similar way, tau protein accumulation seems to be involved in the pathogenesis of tauopathies. Urate, a potent antioxidant, seems to be associated to the risk of developing PD and with its progression. Neurofilament light chain levels are increased in atypical parkinsonian disorders compared with PD and healthy controls. The new "omics" techniques are potent tools offering new insights in the patho-etiology of these disorders. Some of the difficulties encountered in developing biomarkers are discussed together with future perspectives.

  12. ELECTIONS PENSION FUND CANDIDATE NR 2

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : FRANDSEN First Name : Poul Kjaer  I have been member of the staff since 1974, and member of staff council for more than 12 years, and my main motivation has been to work for improving the social conditions of the CERN staff. A very important pillar of this is a sound and healthy pension fund. A capitalised scheme has been and still is the best choice for assuring the benefits for the CERN staff, present and future, this social system being part of the whole necessary to attract the best staff to the future High Energy Physics in Europe. However, even the hypothetic close down of the Organisation should allow the benefits to exi...

  13. ELECTIONS PENSION FUND 2nd candidate

    CERN Multimedia

    2001-01-01

    ORGANISATION EUROPEENNE POUR LA RECHERCHE NUCLEAIRE CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CAISSE DE PENSIONS / PENSION FUND Caisse de Pensions - ELECTIONS - Pension Fund This candidature has been duly registered and is hereby presented in accordance with paragraph 6.h of the Regulations for Elections to the Governing Board of the Pension Fund. Candidate : Name : FRANDSEN First Name : Poul Kjaer  I have been member of the staff since 1974, and member of staff council for more than 12 years, and my main motivation has been to work for improving the social conditions of the CERN staff. A very important pillar of this is a sound and healthy pension fund. A capitalised scheme has been and still is the best choice for assuring the benefits for the CERN staff, present and future, this social system being part of the whole necessary to attract the best staff to the future High Energy Physics in Europe. However, even the hypothetic close down of the Organisation should allow the benefits to exi...

  14. The FK Comae candidate UX Librae

    Science.gov (United States)

    Bopp, B. W.; Goodrich, B. D.; Africano, J. L.; Noah, P. V.; Meredith, R. J.; Palmer, L. H.; Quigley, R. J.

    1984-01-01

    New optical spectroscopic and photometric data are presented for the active chromosphere FK Com candidate UZ Lib. The star is shown to have an extremely large photometric amplitude in V of 0.35 mag, and its rotation period is established as 4.75 + or - 0.01 days. The optical spectrum is that of an early K giant, broadened by a rotation velocity of approximately 65 km/s. H-alpha is visible as a very broad emission feature, with a profile resembling that seen in FK Com. The emission intensity and profile are variable over the rotation period, with the strongest emission present at photometric minimum, in accord with dark starspot models. The photospheric absorption line profiles show variable asymmetries and distortions which are interpreted as due to the effects of the dark starspot rotating across the line of sight. New radial velocity measures are combined with published data to demonstrate the UZ Lib is a member of a binary system in synchronous rotation with a secondary of mass approximately 0.5 solar masses. This information is considered in light of the conflicting models for the origin of the optical and spectral variability of the FK Com stars, as well as their uncertain evolutionary status.

  15. A Catalog of Kepler Habitable Zone Exoplanet Candidates

    Science.gov (United States)

    Kane, Stephen R.; Hill, Michelle L.; Kasting, James F.; Kopparapu, Ravi Kumar; Quintana, Elisa V.; Barclay, Thomas; Batalha, Natalie M.; Borucki, William J.; Ciardi, David R.; Haghighipour, Nader; Hinkel, Natalie R.; Kaltenegger, Lisa; Selsis, Franck; Torres, Guillermo

    2016-10-01

    The NASA Kepler mission ha s discovered thousands of new planetary candidates, many of which have been confirmed through follow-up observations. A primary goal of the mission is to determine the occurrence rate of terrestrial-size planets within the Habitable Zone (HZ) of their host stars. Here we provide a list of HZ exoplanet candidates from the Kepler Q1–Q17 Data Release 24 data-vetting process. This work was undertaken as part of the Kepler HZ Working Group. We use a variety of criteria regarding HZ boundaries and planetary sizes to produce complete lists of HZ candidates, including a catalog of 104 candidates within the optimistic HZ and 20 candidates with radii less than two Earth radii within the conservative HZ. We cross-match our HZ candidates with the stellar properties and confirmed planet properties from Data Release 25 to provide robust stellar parameters and candidate dispositions. We also include false-positive probabilities recently calculated by Morton et al. for each of the candidates within our catalogs to aid in their validation. Finally, we performed dynamical analysis simulations for multi-planet systems that contain candidates with radii less than two Earth radii as a step toward validation of those systems.

  16. Extracting definition candidates from specialized corpora

    Directory of Open Access Journals (Sweden)

    Senja Pollak

    2014-07-01

    Full Text Available Human knowledge is available in different forms, including domain texts, terminological dictionaries, encyclopaediae, and recently also in computer- understandable representations of domain knowledge, such as taxonomies and ontologies. Since manual domain modeling is costly and time-consuming, researchers in human language technologies have started developing methods and tools for semi-automatic extraction of domain-specific knowledge from unstructured texts, involving tasks, such as terminology extraction, definition extraction, semantic relations extraction, or semi-automatic ontology building. This article presents a methodology for definition extraction from domain corpora, currently available for Slovene and English. Since most of the existing methods and tools are language specific and not developed for minor languages, the main contribution of the dissertation is the developed definition extraction methodology for Slovene. The proposed definition extraction methodology is based on three different approaches to extracting definition candidates. The first follows the traditional pattern-based approach, in which patterns are composed of lemmas and morphosyntactic descriptions; the second approach relies on pairs of domain terms extracted through automatic term extraction; the third approach exploits wordnet hypernym pairs. We propose an original combination of the three approaches. The developed methodology was applied to a real-case problem of modeling the language technologies domain, for which we constructed a comparable Slovene- English corpus consisting of about two million tokens. We extracted more than 3,400 definition candidates, of which over 700 (approximately 480 for Slovene and 230 for English were evaluated as definitions. The results are used as a basis for the Language Technologies Glossary.17 An additional contribution is the proposed domain-modeling pipeline—from corpus uploading and preprocessing to inspecting the

  17. Characterization for Fusion Candidate Vanadium Alloys

    Institute of Scientific and Technical Information of China (English)

    T. Muroga; T. Nagasaka; J. M. Chen; Z. Y. Xu; Q. Y. Huang; y. C. Wu

    2004-01-01

    This paper summarizes recent achievements in the characterization of candidate vanadium alloys obtained for fusion in the framework of the Japan-China Core University Program.National Institute for Fusion Science (NIFS) has a program of fabricating high-purity V-4Cr4Ti alloys. The resulting products (NIFS-HEAT-1,2), were characterized by various research groups in the world including Chinese partners. South Western Institute of Physics (SWIP) fabricated a new V-4Cr-4Ti alloy (SWIP-Heat), and carried out a comparative evaluation of hydrogen embrittlement of NIFS-HEATs and SWIP-Heat. The tensile test of hydrogen-doped alloys showed that the NIFS-HEAT maintained the ductility to relatively high hydrogen levels.The comparison of the data with those of previous studies suggested that the reduced oxygen level in the NIFS-HEATs should be responsible for the increased resistance to hydrogen embrittlement.Based on the chemical analysis data of NIFS-HEATs and SWIP-Heats, neutron-induced activation was analyzed in Institute of Plasma Physics (IPP-CAS) as a function of cooling time after the use in the fusion first wall. The results showed that the low level of Co dominates the activity up to 50 years followed by a domination of Nb or Nb and Al in the respective alloys. It was suggested that reduction of Co and Nb, both of which are thought to have been introduced via cross-contamination into the alloys from the molds used should be crucial for reducing further the activation.

  18. Primary-Grade Teacher Candidates' Views on Museum Education

    Science.gov (United States)

    Tas, Ayse Mentis

    2012-01-01

    This study identifies the primary-grade teacher candidates' views on museum education. The research is a descriptive research that used survey model. The study group is made up of 209 primary-grade teacher candidates who were seniors in the Primary-Grade Teaching Program. They were all attending Konya University's Faculty of Education. A survey…

  19. Investigating Academic Achievements and Critical Thinking Dispositions of Teacher Candidates

    Science.gov (United States)

    Karagöl, Ibrahim; Bekmezci, Sinan

    2015-01-01

    The aim of this study is to examine the relationship between academic achievements and critical thinking dispositions of teacher candidates in Faculty of Education and to find out whether critical thinking dispositions and academic achievements scores of teacher candidates differ according to different variables. The population consists of the…

  20. Chemical Literacy Levels of Science and Mathematics Teacher Candidates

    Science.gov (United States)

    Celik, Suat

    2014-01-01

    The goal of this study was to investigate Turkish science and mathematics teacher candidates' levels of attainment in chemical literacy. These candidates had all studied the new Turkish chemistry curriculum in high school. The sample of the study consisted of 112 students, who were first-year students in the Department of Secondary Science…

  1. Five kepler target stars that show multiple transiting exoplanet candidates

    DEFF Research Database (Denmark)

    Steffen..[], Jason H.; Batalha, N. M.; Broucki, W J.;

    2010-01-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets...

  2. 11 CFR 106.1 - Allocation of expenses between candidates.

    Science.gov (United States)

    2010-01-01

    ... broadcast communication, the attribution shall be determined by the proportion of space or time devoted to... non-Federal candidates, and that is made by a political committee with separate Federal and non...) An authorized expenditure made by a candidate or political committee on behalf of another...

  3. Social Studies Teacher Candidates' Views on Historical Thinking Skills

    Science.gov (United States)

    Ozmen, Cengiz

    2015-01-01

    Current study aimed to present Social Studies teacher candidates' views on historical thinking skills. Study was conducted using qualitative design and working group was composed of a total of 121 teacher candidates (62 females and 59 males) attending Social Studies Teaching Department of Karadeniz Technical University and Adiyaman University…

  4. Preparing Preservice Teacher Candidates to Differentiate Instructional Practices

    Science.gov (United States)

    Ochoa, Bianca R.

    2013-01-01

    This action research study focused on how various grouping strategies influenced preservice teachers' differentiation of instruction. The participants included a third grade mentor teacher and three preservice teacher candidates. The candidate preparation curriculum consisted of seminars, daily field-based learning experiences, and ongoing…

  5. 11 CFR 100.152 - Fundraising costs for Presidential candidates.

    Science.gov (United States)

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Fundraising costs for Presidential candidates... U.S.C. 431) Exceptions to Expenditures § 100.152 Fundraising costs for Presidential candidates. (a... the solicitation of contributions means any cost reasonably related to fundraising activity,...

  6. Opinions of Counselor Candidates Regarding Counseling Skills Training

    Science.gov (United States)

    Aladag, Mine; Yaka, Baris; Koç, Ismet

    2014-01-01

    The aim of this study is to contribute to the enhancement of the quality of counseling skills training and counselor education through the medium of understanding the opinions of counselor candidates regarding counseling skills training. The research group consisted of 67 counselor candidates who voluntarily participated in the study. The research…

  7. Writing Instruction for Teacher Candidates: Strengthening a Weak Curricular Area

    Science.gov (United States)

    Grisham, Dana L.; Wolsey, Thomas Devere

    2011-01-01

    In this case study, two teacher educators in literacy examined teacher candidates' (N = 24) learning of writing instruction across a three-course sequence of literacy methods. Data collected included a survey of candidates' knowledge of writing instruction, their formal observations of writing lessons in their student-teaching placements, a…

  8. Assessing Student Teaching Experiences: Teacher Candidates' Perceptions of Preparedness

    Science.gov (United States)

    Lee, Joohi; Tice, Kathleen; Collins, Denise; Brown, Amber; Smith, Cleta; Fox, Jill

    2012-01-01

    The purpose of this study is to investigate the effectiveness of student teaching experiences by measuring teacher candidates' perceptions of their preparedness. The participants were 130 teacher candidates who had completed their student teaching as part of a program preparing them to teach children in pre-K through grade 4. Teacher candidates…

  9. Fostering the Development of Chemistry Teacher Candidates: A Bioecological Approach

    Science.gov (United States)

    Lewthwaite, Brian; Wiebe, Rick

    2012-01-01

    This ongoing research inquiry investigates through the analysis of teacher candidate experiences the factors influencing two groups of chemistry teacher candidates' development during their extended practica in their second and final year of an after-degree bachelor of education at a university in central Canada. The tenets of Bronfenbrenner's…

  10. DAZLA: an important candidate gene in male subfertility?

    NARCIS (Netherlands)

    Golde, R.J.T. van; Tuerlings, J.H.A.M.; Kremer, J.A.M.; Braat, D.D.M.; Schoute, F.; Hoefsloot, L.H.

    2001-01-01

    PURPOSE: To study the role of the autosomal candidate gene DAZLA (Deleted in AZoospermia Like Autosome) in male subfertility. METHODS: We reviewed clinical data of subfertile men with oligozoospermia or azoospermia, mostly candidates for intracytoplasmic sperm injection (ICSI). Mutation detection wa

  11. Facebook Connection Styles among Physical Education Teacher Candidates

    Science.gov (United States)

    Erdogdu, Murat

    2016-01-01

    The purpose of this study is to determine the Facebook connection styles of physical education (PE) teacher candidates. The participants were composed of 626 (age = 21.21 ± 2.024) physical education teacher candidates from the departments of Physical Education and Sports. They teach in five different universities. It was done in 2014-2015 academic…

  12. Developing Benchmarks to Measure Teacher Candidates' Performance

    Science.gov (United States)

    Frazier, Laura Corbin; Brown-Hobbs, Stacy; Palmer, Barbara Martin

    2013-01-01

    This paper traces the development of teacher candidate benchmarks at one liberal arts institution. Begun as a classroom assessment activity over ten years ago, the benchmarks, through collaboration with professional development school partners, now serve as a primary measure of teacher candidates' performance in the final phases of the…

  13. Sensitive radio survey of obscured quasar candidates

    Science.gov (United States)

    Alexandroff, Rachael M.; Zakamska, Nadia L.; van Velzen, Sjoert; Greene, Jenny E.; Strauss, Michael A.

    2016-12-01

    We study the radio properties of moderately obscured quasars in samples at both low (z ˜ 0.5) and high (z ˜ 2.5) redshift to understand the role of radio activity in accretion, using the Karl G. Jansky Very Large Array (VLA) at 6.0 GHz and 1.4 GHz. Our z ˜ 2.5 sample consists of optically selected obscured quasar candidates, all of which are radio-quiet, with typical radio luminosities of νLν[1.4 GHz] ≲ 1040 erg s-1. Only a single source is individually detected in our deep (rms˜10 μJy) exposures. This population would not be identified by radio-based selection methods used for distinguishing dusty star-forming galaxies and obscured active nuclei. In our pilot A-array study of z ˜ 0.5 radio-quiet quasars, we spatially resolve four of five objects on scales ˜5 kpc and find they have steep spectral indices with an average value of α = -0.75. Therefore, radio emission in these sources could be due to jet-driven or radiatively driven bubbles interacting with interstellar material on the scale of the host galaxy. Finally, we also study the additional population of ˜200 faint ( ˜ 40 μJy-40 mJy) field radio sources observed over ˜120 arcmin2 of our data. 60 per cent of these detections (excluding our original targets) are matched in the Sloan Digital Sky Survey (SDSS) and/or Wide-Field Infrared Survey Explorer (WISE) and are, in roughly equal shares, active galactic nuclei (AGN) at a broad range of redshifts, passive galaxies with no other signs of nuclear activity and infrared-bright but optically faint sources. Spectroscopically or photometrically confirmed star-forming galaxies constitute only a small minority of the matches. Such sensitive radio surveys allow us to address important questions of AGN evolution and evaluate the AGN contribution to the radio-quiet sky.

  14. Almost All of Kepler's Multiple Planet Candidates are Planets

    CERN Document Server

    Lissauer, Jack J; Rowe, Jason F; Bryson, Stephen T; Adams, Elisabeth; Buchhave, Lars A; Ciardi, David R; Cochran, William D; Fabrycky, Daniel C; Ford, Eric B; Fressin, Francois; Geary, John; Gilliland, Ronald L; Holman, Matthew J; Howell, Steve B; Jenkins, Jon M; Kinemuchi, Karen; Koch, David G; Morehead, Robert C; Ragozzine, Darin; Seader, Shawn E; Tanenbaum, Peter G; Torres, Guillermo; Twicken, Joseph D

    2012-01-01

    We present a statistical analysis that demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically-associated transiting planets. Binary stars provide the primary source of false positives among Kepler planet candidates, implying that false positives should be nearly randomly-distributed among Kepler targets. In contrast, true transiting planets would appear clustered around a smaller number of Kepler targets if detectable planets tend to come in systems and/or if the orbital planes of planets encircling the same star are correlated. There are more than one hundred times as many Kepler planet candidates in multi-candidate systems as would be predicted from a random distribution of candidates, implying that the vast majority are true planets. Most of these multis are multiple planet systems orbiting the Kepler target star, but there are likely cases where (a) the planetary system orbits a fainter star, and the planets are thus significa...

  15. PEACE: Pulsar Evaluation Algorithm for Candidate Extraction -- A software package for post-analysis processing of pulsar survey candidates

    CERN Document Server

    Lee, K J; Jenet, F A; Martinez, J; Dartez, L P; Mata, A; Lunsford, G; Cohen, S; Biwer, C M; Rohr, M; Flanigan, J; Walker, A; Banaszak, S; Allen, B; Barr, E D; Bhat, N D R; Bogdanov, S; Brazier, A; Camilo, F; Champion, D J; Chatterjee, S; Cordes, J; Crawford, F; Deneva, J; Desvignes, G; Ferdman, R D; Freire, P; Hessels, J W T; Karuppusamy, R; Kaspi, V M; Knispel, B; Kramer, M; Lazarus, P; Lynch, R; Lyne, A; McLaughlin, M; Ransom, S; Scholz, P; Siemens, X; Spitler, L; Stairs, I; Tan, M; van Leeuwen, J; Zhu, W W

    2013-01-01

    Modern radio pulsar surveys produce a large volume of prospective candidates, the majority of which are polluted by human-created radio frequency interference or other forms of noise. Typically, large numbers of candidates need to be visually inspected in order to determine if they are real pulsars. This process can be labor intensive. In this paper, we introduce an algorithm called PEACE (Pulsar Evaluation Algorithm for Candidate Extraction) which improves the efficiency of identifying pulsar signals. The algorithm ranks the candidates based on a score function. Unlike popular machine-learning based algorithms, no prior training data sets are required. This algorithm has been applied to data from several large-scale radio pulsar surveys. Using the human-based ranking results generated by students in the Arecibo Remote Command enter programme, the statistical performance of PEACE was evaluated. It was found that PEACE ranked 68% of the student-identified pulsars within the top 0.17% of sorted candidates, 95% ...

  16. A Catalog of Kepler Habitable Zone Exoplanet Candidates

    CERN Document Server

    Kane, Stephen R; Kasting, James F; Kopparapu, Ravi Kumar; Quintana, Elisa V; Barclay, Thomas; Batalha, Natalie M; Borucki, William J; Ciardi, David R; Haghighipour, Nader; Hinkel, Natalie R; Kaltenegger, Lisa; Selsis, Franck; Torres, Guillermo

    2016-01-01

    The NASA Kepler mission has discovered thousands of new planetary candidates, many of which have been confirmed through follow-up observations. A primary goal of the mission is to determine the occurrance rate of terrestrial-size planets within the Habitable Zone (HZ) of their host stars. Here we provide a list of HZ exoplanet candidates from the Kepler Data Release 24 Q1-Q17 data vetting process. This work was undertaken as part of the Kepler Habitable Zone Working Group. We use a variety of criteria regarding HZ boundaries and planetary sizes to produce complete lists of HZ candidates, including a catalog of 104 candidates within the optimistic HZ and 20 candidates with radii less than two Earth radii within the conservative HZ. We cross-match our HZ candidates with the Data Release 25 stellar properties and confirmed planet properties to provide robust stellar parameters and candidate dispositions. We also include false positive probabilities recently calculated by Morton et al. (2016) for each of the cand...

  17. Pathogenic Network Analysis Predicts Candidate Genes for Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Yun-Xia Zhang

    2016-01-01

    Full Text Available Purpose. The objective of our study was to predicate candidate genes in cervical cancer (CC using a network-based strategy and to understand the pathogenic process of CC. Methods. A pathogenic network of CC was extracted based on known pathogenic genes (seed genes and differentially expressed genes (DEGs between CC and normal controls. Subsequently, cluster analysis was performed to identify the subnetworks in the pathogenic network using ClusterONE. Each gene in the pathogenic network was assigned a weight value, and then candidate genes were obtained based on the weight distribution. Eventually, pathway enrichment analysis for candidate genes was performed. Results. In this work, a total of 330 DEGs were identified between CC and normal controls. From the pathogenic network, 2 intensely connected clusters were extracted, and a total of 52 candidate genes were detected under the weight values greater than 0.10. Among these candidate genes, VIM had the highest weight value. Moreover, candidate genes MMP1, CDC45, and CAT were, respectively, enriched in pathway in cancer, cell cycle, and methane metabolism. Conclusion. Candidate pathogenic genes including MMP1, CDC45, CAT, and VIM might be involved in the pathogenesis of CC. We believe that our results can provide theoretical guidelines for future clinical application.

  18. Planet Hunters VI: The First Kepler Seven Planet Candidate System and 13 Other Planet Candidates from the Kepler Archival Data

    CERN Document Server

    Schmitt, Joseph R; Fischer, Debra A; Jek, Kian J; Moriarty, John C; Boyajian, Tabetha S; Schwamb, Megan E; Lintott, Chris; Smith, Arfon M; Parrish, Michael; Schawinski, Kevin; Lynn, Stuart; Simpson, Robert; Omohundro, Mark; Winarski, Troy; Goodman, Samuel J; Jebson, Tony; Lacourse, Daryll

    2013-01-01

    We report the discovery of 14 new transiting planet candidates in the Kepler field from the Planet Hunters citizen science program. None of these candidates overlap with Kepler Objects of Interest (KOIs), and five of the candidates were missed by the Kepler Transit Planet Search (TPS) algorithm. The new candidates have periods ranging from 124-904 days, eight residing in their host star's habitable zone (HZ) and two (now) in multiple planet systems. We report the discovery of one more addition to the six planet candidate system around KOI-351, marking the first seven planet candidate system from Kepler. Additionally, KOI-351 bears some resemblance to our own solar system, with the inner five planets ranging from Earth to mini-Neptune radii and the outer planets being gas giants; however, this system is very compact, with all seven planet candidates orbiting $\\lesssim 1$ AU from their host star. We perform a numerical integration of the orbits and show that the system remains stable for over 100 million years....

  19. Campaigning on the Internet: 2008 Presidential General Election Candidate Webpage

    Directory of Open Access Journals (Sweden)

    William L. Benoit

    2016-12-01

    Full Text Available The Internet is becoming an increasingly important component of political campaigns. This study employed content analysis to apply Functional Theory and Issue Ownership Theory to Obama’s and McCain’s presidential candidate webpages in the 2008 campaign. Acclaims (92% were more common than attacks (98%; defenses did not occur in this sample. Policy (82% was addressed more than character (18%. When discussing policy, these candidates addressed future plans most frequently, followed by general goals and then past deeds; on character, candidates discussed ideals, then personal qualities, and then leadership ability. This study shows that as candidates use the Internet to reach voters, their webpages conform to theoretical expectations.

  20. Spectroscopy of candidate electromagnetic counterparts to gravitational wave sources

    CERN Document Server

    Steele, Iain A; Piascik, Andrzej S

    2016-01-01

    A programme of worldwide, multi-wavelength electromagnetic follow-up of sources detected by gravitational wave detectors is in place. Following the discovery of GW150914 and GW151226, wide field imaging of their sky localisations identified a number of candidate optical counterparts which were then spectrally classified. The majority of candidates were found to be supernovae at redshift ranges similar to the GW events and were thereby ruled out as a genuine counterpart. Other candidates ruled out include AGN and solar system objects. Given the GW sources were black hole binary mergers, the lack of an identified electromagnetic counterpart is not surprising. However the observations show that is it is possible to organise and execute a campaign that can eliminate the majority of potential counterparts. Finally we note the existence of a "classification gap" with a significant fraction of candidates going unclassified.

  1. 11 CFR 100.148 - Volunteer activity for candidate.

    Science.gov (United States)

    2010-01-01

    ..., magazines, billboards, direct mail or similar types of general public communication or political advertising... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for...

  2. 11 CFR 100.88 - Volunteer activity for candidates.

    Science.gov (United States)

    2010-01-01

    ..., billboards, direct mail or similar types of general public communication or political advertising. (b) The... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for...

  3. 15 CFR 922.21 - Selection of active candidates.

    Science.gov (United States)

    2010-01-01

    ... from the SEL for Active Candidate consideration based on a preliminary assessment of the designation... environmental impact statement shall be published in the Federal Register and in newspapers in the area(s)...

  4. The impact of alternate fuels on future candidate automotive engines

    Energy Technology Data Exchange (ETDEWEB)

    Rahnke, C.J.; Nichols, R.J.

    1982-06-01

    The thermal efficiency that could occur in the future for a variety of automotive engine candidates operating on conventional and alternate fuels is projected based on current automotive engine development trends and the special characteristics of the various alternate fuels. The multi-fuel engine candidates include mixture cycle and direct injection reciprocating engines, as well as adiabatic turbocompound engines and advanced gas turbine and Stirling engines. The alternate fuels considered are propane, methanol, ethanol, diesel and methane.

  5. Radiative Neutrino Mass via Both Minimal Dark Matter Candidates

    CERN Document Server

    Ahriche, Amine; Nasri, Salah; Picek, Ivica

    2016-01-01

    We identify a minimal model achieving one-loop radiative neutrino masses due to couplings with dark matter. Interestingly the model contains both the quintuplet fermion and the septuplet scalar identified as minimal dark matter candidates by Cirelli, Fornengo and Strumia - it gives radiative neutrino mass due to both minimal dark matter candidates. The model is related to those proposed in a recent work (dubbed minimal R$\

  6. Transiting exoplanet candidates from K2 Campaigns 5 and 6

    Science.gov (United States)

    Pope, Benjamin J. S.; Parviainen, Hannu; Aigrain, Suzanne

    2016-10-01

    We introduce a new transit search and vetting pipeline for observations from the K2 mission, and present the candidate transiting planets identified by this pipeline out of the targets in Campaigns 5 and 6. Our pipeline uses the Gaussian process-based K2SC code to correct for the K2 pointing systematics and simultaneously model stellar variability. The systematics-corrected, variability-detrended light curves are searched for transits with the box-least-squares method, and a period-dependent detection threshold is used to generate a preliminary candidate list. Two or three individuals vet each candidate manually to produce the final candidate list, using a set of automatically generated transit fits and assorted diagnostic tests to inform the vetting. We detect 145 single-planet system candidates and 5 multi-planet systems, independently recovering the previously published hot Jupiters EPIC 212110888b, WASP-55b (EPIC 212300977b) and Qatar-2b (EPIC 212756297b). We also report the outcome of reconnaissance spectroscopy carried out for all candidates with Kepler magnitude Kp ≤ 13, identifying 12 targets as likely false positives. We compare our results to those of other K2 transit search pipelines, noting that ours performs particularly well for variable and/or active stars, but that the results are very similar overall. All the light curves and code used in the transit search and vetting process are publicly available, as are the follow-up spectra.

  7. 22 CFR 11.11 - Mid-level Foreign Service officer career candidate appointments.

    Science.gov (United States)

    2010-04-01

    ... affirmative factor in the selection of candidates for appointment as Foreign Service officer career candidates..., experience, and skills needed by the Foreign Service at the mid-level. (3) Age. All career candidate... terminated and the candidate so informed. (10) Foreign language requirement. All candidates who pass the...

  8. Robo-AO Kepler Planetary Candidate Survey. III. Adaptive Optics Imaging of 1629 Kepler Exoplanet Candidate Host Stars

    Science.gov (United States)

    Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Baranec, Christoph; Riddle, Reed; Atkinson, Dani; Baker, Anna; Roberts, Sarah; Ciardi, David R.

    2017-02-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results of our search for stars nearby 1629 Kepler planet candidate hosts. With survey sensitivity to objects as close as ∼0.″15, and magnitude differences Δm ≤slant 6, we find 223 stars in the vicinity of 206 target KOIs; 209 of these nearby stars have not been previously imaged in high resolution. We measure an overall nearby-star probability for Kepler planet candidates of 12.6 % +/- 0.9 % at separations between 0.″15 and 4.″0. Particularly interesting KOI systems are discussed, including 26 stars with detected companions that host rocky, habitable zone candidates and five new candidate planet-hosting quadruple star systems. We explore the broad correlations between planetary systems and stellar binarity, using the combined data set of Baranec et al. and this paper. Our previous 2σ result of a low detected nearby star fraction of KOIs hosting close-in giant planets is less apparent in this larger data set. We also find a significant correlation between detected nearby star fraction and KOI number, suggesting possible variation between early and late Kepler data releases.

  9. Robo-AO Kepler Planetary Candidate Survey III: Adaptive Optics Imaging of 1629 Kepler Exoplanet Candidate Host Stars

    CERN Document Server

    Ziegler, Carl; Morton, Tim; Baranec, Christoph; Riddle, Reed; Atkinson, Dani; Baker, Anna; Roberts, Sarah; Ciardi, David R

    2016-01-01

    The Robo-AO \\textit{Kepler} Planetary Candidate Survey is observing every \\textit{Kepler} planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. We present in this paper the results of our search for stars nearby 1629 \\textit{Kepler} planet candidate hosts. With survey sensitivity to objects as close as $\\sim$0.15" and magnitude differences $\\Delta$m$\\le$6, we find 223 stars in the vicinity of 206 target KOIs; 209 of these nearby stars have not previously been imaged in high resolution. We measure an overall nearby-star probability for \\textit{Kepler} planet candidates of 12.6\\%$\\pm$0.9\\% out to a separation of 4.0". Particularly interesting KOI systems are discussed, including 23 stars with detected companions which host rocky, habitable zone candidates, and five new candidate planet-hosting quadruple star systems. We explore the broad correlations between planetary systems...

  10. The phase lags of high-frequency quasi-periodic oscillations in four black-hole candidates

    CERN Document Server

    Mendez, Mariano; Belloni, Tomaso; Sanna, Andrea

    2013-01-01

    We measured the phase-lag spectrum of the high-frequency quasi-periodic oscillations (QPO) in the black hole systems (at QPO frequencies) GRS 1915+105 (35 Hz and 67 Hz), GRO J1655-40 (300 Hz and 450 Hz), XTE J1550-564 (180 Hz and 280 Hz), and IGR J17091-3624 (67 Hz). The lag spectra of the 67-Hz QPO in, respectively, GRS 1915+105 and IGR J17091-3624, and the 450-Hz QPO in GRO J1655-40 are hard (hard photons lag the soft ones) and consistent with each other, with the hard lags increasing with energy. On the contrary, the lags of the 35-Hz QPO in GRS 1915+105 are soft, with the lags becoming softer as the energy increases; the lag spectrum of the 35-Hz QPO is inconsistent with that of the 67-Hz QPO. The lags of the 300-Hz QPO in GRO J1655-40, and the 180-Hz and the 280-Hz QPO in XTE J1550-564 are independent of energy, consistent with each other and with being zero or slightly positive (hard lags). For GRO J1655-40 the lag spectrum of the 300-Hz QPO differs significantly from that of the 450-Hz QPOs. The simila...

  11. Properties of Optically Selected Supernova Remnant Candidates in M33

    CERN Document Server

    Lee, Jong Hwan

    2014-01-01

    We present a sample of supernova remnant (SNR) candidates in M33 based on optical narrow band images in the Local Group Survey. We identify emission line objects that have enhanced [SII]:H{\\alpha} (> 0.4) and circular shapes using continuum-subtracted H{\\alpha}and [SII] images and produce a list of 199 SNR candidates, of which 79 are previously unknown. We classify them considering two types of criteria: their progenitor type (Type Ia and core-collapse (CC) SNRs) and their morphological type. Of the total sample, 170 are likely remnants of CC SNe and 29 are likely remnants of Type Ia SNe. We obtain a cumulative size distribution of the SNR candidates, showing that it follows a power law with an index,{\\alpha}= 2.38{\\pm}0.05 (17 < D < 50 pc). This indicates that most of the M33 SNR candidates found in this study are in the Sedov-Taylor phase, consistent with previous findings. The [SII]:H{\\alpha} distribution of the SNR candidates shows two peaks at [SII]:H{\\alpha} ~0.55 and ~0.8. Interestingly X-ray and...

  12. Fuzzy Logic Based Trusted Candidate Selection for Stable Multipath Routing

    Directory of Open Access Journals (Sweden)

    Sujata V. Mallapur

    2015-05-01

    Full Text Available In mobile ad hoc networks (MANETs, providing reliable and stable communication paths between wireless devices is critical. This paper presents a fuzzy logic stablebackbone-based multipath routing protocol (FLSBMRP for MANET that provides a high-quality path for communication between nodes. The proposed protocol has two main phases. The first phase is the selection of candidate nodes using a fuzzy logic technique. The second phase is the construction of a routing backbone that establishes multiple paths between nodes through the candidate nodes, thus forming a routing backbone. If any candidate node in the path fails due to a lack of bandwidth, residual energy or link quality, an alternate path through another candidate node is selected for communication before the route breaks, because a candidate node failure may lead to a broken link between the nodes. Simulation results demonstrate that the proposed protocol performs better in terms of the packet delivery ratio, overhead, delay and packet drop ratio than the major existing ad hoc routing protocols.

  13. Transiting exoplanet candidates from K2 Campaigns 5 and 6

    CERN Document Server

    Pope, Benjamin J S; Aigrain, Suzanne

    2016-01-01

    We introduce a new transit search and vetting pipeline for observations from the K2 mission, and present the candidate transiting planets identified by this pipeline out of the targets in Campaigns 5 and 6. Our pipeline uses the Gaussian Process-based K2SC code to correct for the K2 pointing systematics and simultaneously model stellar variability. The systematics-corrected, variability-detrended light curves are searched for transits with the Box Least Squares method, and a period-dependent detection threshold is used to generate a preliminary candidate list. Two or three individuals vet each candidate manually to produce the final candidate list, using a set of automatically-generated transit fits and assorted diagnostic tests to inform the vetting. We detect 147 single-planet system candidates and 5 multi-planet systems, independently recovering the previously-published hot~Jupiters EPIC 212110888b, WASP-55b (EPIC 212300977b) and Qatar-2b (EPIC 212756297b). We also report the outcome of reconnaissance spec...

  14. On security arguments of the second round SHA-3 candidates

    DEFF Research Database (Denmark)

    Andreeva, Elena; Bogdanov, Andrey; Mennink, Bart;

    2012-01-01

    In 2007, the US National Institute for Standards and Technology (NIST) announced a call for the design of a new cryptographic hash algorithm in response to vulnerabilities like differential attacks identified in existing hash functions, such as MD5 and SHA-1. NIST received many submissions, 51...... of which got accepted to the first round. 14 candidates were left in the second round, out of which five candidates have been recently chosen for the final round. An important criterion in the selection process is the SHA-3 hash function security. We identify two important classes of security arguments...... for the new designs: (1) the possible reductions of the hash function security to the security of its underlying building blocks and (2) arguments against differential attack on building blocks. In this paper, we compare the state of the art provable security reductions for the second round candidates...

  15. BL LAC candidates for TeV observations

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Paggi, A.; Errando, M.; D' Abrusco, R.; Masetti, N.; Tosti, G.; Funk, S.

    2013-07-01

    BL Lac objects are the most numerous class of extragalactic TeV-detected sources. One of the biggest difficulties in investigating their TeV emission is due to their limited number, since only 47 BL Lac objects are known to be TeV emitters. In this paper, we propose new criteria to select TeV BL Lac candidates based on infrared and X-ray observations. We apply our selection criteria to the BL Lac objects listed in the ROMA-BZCAT catalog, thereby identifying 41 potential TeV emitters. We then perform a search over a more extended sample combining the ROSAT bright source catalog and the WISE all-sky survey, revealing 54 additional candidates for TeV observations. Our investigation also led to a tentative classification of 16 unidentified X-ray sources as BL Lac candidates. This analysis provides new interesting BL Lac targets for future observations with ground-based Cherenkov telescopes.

  16. Natural Flavonoids as Promising Analgesic Candidates: A Systematic Review.

    Science.gov (United States)

    Xiao, Xiao; Wang, Xiaoyu; Gui, Xuan; Chen, Lu; Huang, Baokang

    2016-11-01

    Due to the chemical structural diversity and various analgesic mechanisms, an increasing number of studies indicated that some flavonoids from medicinal plants could be promising candidates for new natural analgesic drugs, which attract high interests of advanced users and academic researchers. The aim of this systematic review is to report flavonoids and its derivatives as new analgesic candidates based on the pharmacological evidences. Sixty-four papers were found concerning the potential analgesic activity of 46 flavonoids. In this case, the evidence for analgesic activity of flavonoids and total flavonoids was investigated. Meanwhile, the corresponding analgesic mechanism of flavonoids was discussed by generalizing and analyzing the current publications. Based on this review, the conclusion can be drawn that some flavonoids are promising candidates for painful conditions and deserve particular attention in further research and development.

  17. Five Kepler target stars that show multiple transiting exoplanet candidates

    CERN Document Server

    Steffen, Jason H; Borucki, William J; Buchhave, Lars A; Caldwell, Douglas A; Cochran, William D; Endl, Michael; Fabrycky, Daniel C; Fressin, François; Ford, Eric B; Fortney, Jonathan J; Haas, Michael J; Holman, Matthew J; Isaacson, Howard; Jenkins, Jon M; Koch, David; Latham, David W; Lissauer, Jack J; Moorhead, Althea V; Morehead, Robert C; Marcy, Geoffrey; MacQueen, Phillip J; Quinn, Samuel N; Ragozzine, Darin; Rowe, Jason F; Sasselov, Dimitar D; Seager, Sara; Torres, Guillermo; Welsh, William F

    2010-01-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets and provide new insights into the formation and dynamical evolution of planetary systems. We discuss the methods used to identify multiple transiting objects from the Kepler photometry as well as the false-positive rejection methods that have been applied to these data. One system shows transits from three distinct objects while the remaining four systems show transits from two objects. Three systems have planet candidates that are near mean motion commensurabilities - two near 2:1 and one just outside 5:2. We discuss the implications that multitransiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories; as well as their likely masses and chemical compos...

  18. Additional TWA Members? Spectroscopic verification of kinematically selected TWA candidates

    CERN Document Server

    Song, I; Zuckerman, B; Song, Inseok

    2002-01-01

    We present spectroscopic measurements of the 23 new candidate members of the TW Hydrae Association from Makarov & Fabricius (2000). Based on Halpha and Li 6708 A strengths together with location on a color-magnitude diagram for Hipparcos TWA candidates, we found only three possible new members (TYC 7760-0835-1, TYC 8238-1462-1, and TYC 8234-2856-1) in addition to the already known member, TWA 19. This eliminated most of the candidates more distant than 100 pc. Three Tycho stars, almost certainly members of the Lower Centaurus Crux association, are the most distant members of the TWA. A claim of isotropic expansion of TWA has to be re-evaluated based on our new results. Generally, one cannot identify new members of a diffuse nearby stellar group based solely on kinematic data. To eliminate interlopers with similar kinematics, spectroscopic verification is essential.

  19. Planetary Nebula Candidates Uncovered with the HASH Research Platform

    CERN Document Server

    Fragkou, Vasiliki; Frew, David; Parker, Quentin

    2016-01-01

    A detailed examination of new high quality radio catalogues (e.g. Cornish) in combination with available mid-infrared (MIR) satellite imagery (e.g. Glimpse) has allowed us to find 70 new planetary nebula (PN) candidates based on existing knowledge of their typical colors and fluxes. To further examine the nature of these sources, multiple diagnostic tools have been applied to these candidates based on published data and on available imagery in the HASH (Hong Kong/ AAO/ Strasbourg H{\\alpha} planetary nebula) research platform. Some candidates have previously-missed optical counterparts allowing for spectroscopic follow-up. Indeed, the single object spectroscopically observed so far has turned out to be a bona fide PN.

  20. Evaluation of candidate geomagnetic field models for IGRF-11

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    coefficients is also reported. Maps of differences in the vertical field intensity at Earth’s surface between the candidates and weighted mean models are presented. Candidates with anomalous aspects are identified and efforts made to pinpoint both troublesome coefficients and geographical regions where large...... vector satellite data is demonstrated; based on internal consistency DGRF-2005 has a formal root mean square vector field error over Earth’s surface of 1.0 nT. Difficulties nevertheless remain in accurately forecasting field evolution only five years into the future....

  1. Light Sensor Candidates for the Cherenkov Telescope Array

    CERN Document Server

    Knoetig, M L; Kurz, M; Hose, J; Lorenz, E; Schweizer, T; Teshima, M; Buzhan, P; Popova, E; Bolmont, J; Tavernet, J -P; Vincent, P; Shayduk, M

    2011-01-01

    We report on the characterization of candidate light sensors for use in the next-generation Imaging Atmospheric Cherenkov Telescope project called Cherenkov Telescope Array, a major astro-particle physics project of about 100 telescopes that is currently in the prototyping phase. Our goal is to develop with the manufacturers the best possible light sensors (highest photon detection efficiency, lowest crosstalk and afterpulsing). The cameras of those telescopes will be based on classical super-bi-alkali Photomultiplier tubes but also Silicon Photomultipliers are candidate light sensors. A full characterisation of selected sensors was done. We are working in close contact with several manufacturers, giving them feedback and suggesting improvements.

  2. Former Head of CNOOC Named as Candidate for Governor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ The Central Committee of the Chinese Communist Party has appointed Wei Liucheng, Former President of CNOOC and Former Chairman and CEO of CNOOC Limited, as Deputy Secretary of Hainan Provincial Committee and named him as the candidate for Governor of Hainan Province. At a conference of Hainan Provincial Committee of the Party held on October 8, at which the organization department of the Communist Party of China announced nomination of Wei as the deputy Party secretary of Hainan, which is the second highest position in the provincial government. Wei was also chosen as a candidate for the governor of the island province.

  3. Practical Large Scale Syntheses of New Drug Candidates

    Institute of Scientific and Technical Information of China (English)

    Hui-Yin Li

    2001-01-01

    @@ This presentation will be focus on Practical large scale syntheses of lead compounds and drug candidates from three major therapeutic areas from DuPont Pharmaceuticals Research Laboratory: 1). DMP777-a selective, non-toxic, orally active human elastase inhibitor; 2). DMP754-a potent glycoprotein IIb/IIIa antagonist; 3). R-Wafarin-the pure enantiomeric form of wafarin. The key technology used for preparation these drug candidates is asymmetric hydrogenation under very mild reaction conditions, which produced very high quality final products at large scale (>99% de, >99 A% and >99 wt%). Some practical and GMP aspects of process development will be also discussed.

  4. Decomposing the Relationship Between Candidates' Facial Appearance and Electoral Success

    DEFF Research Database (Denmark)

    Laustsen, Lasse

    2014-01-01

    candidates’ faces and electoral success is challenged in two ways: (i) non-facial factors in candidate photos such as clothing and hair style as well as (ii) parties’ nomination strategies are suggested as potential confounds. This study is based on original data about all 268 candidates running in three...... facial competence also predicts electoral success over and above what can be accounted for by attractiveness. Importantly these relationships are found when seven different non-facial factors, parties’ nomination strategies and candidates’ age and gender are controlled for. This suggests that the two...

  5. Facial discrimination of political candidates and voting behavior

    Directory of Open Access Journals (Sweden)

    Alina Duduciuc

    2012-04-01

    Full Text Available After a review of psychosociological research concerning the sources of prejudices and discriminations, this article brings into discussion the cognitive approach of perceiving the other as being „otherwise” than the members of the in-group. We will discuss the situations, structural and personal factors as being some determining ones for discriminant behavior. Within the lines of cognitive paradigm, we ask how the individual does discriminate, by perceptive processes, between candidates which are considered attractive, which go together with the expectations of the electorate concerning the physical aspects and candidates who are „less desirable”.

  6. A preliminary systems assessment of the Starlite Demo candidates

    Energy Technology Data Exchange (ETDEWEB)

    Bathke, C.G.

    1995-12-01

    The Starlite project has evaluated the following five tokamaks as candidates for the US Demo Power Plant: (1) steady state, first stability regime; (2) pulsed, first stability regime; (3) steady state, second stability regime; (4) steady state, reversed shear; and (5) steady state, low aspect ratio. Systems analysis of these candidates has played an important role in the selection of a reversed-shear tokamak for further conceptual design as a US Demo Power Plant. The cost-based systems analysis that led to the selection of a reversed-shear tokamak is described herein.

  7. On Intrinsic Magnetic Moments In Black Hole Candidates

    CERN Document Server

    Robertson, S L; Robertson, Stanley L.; Leiter, Darryl J.

    2003-01-01

    In previous work we found that many of the spectral properties of low mass x-ray binaries, including galactic black hole candidates could be explained by a magnetic propeller model that requires an intrinsically magnetized central object. Here we describe how the Einstein field equations of General Relativity and equipartition magnetic fields permit the existence of highly red shifted, extremely long lived, collapsing, radiating objects. We examine the properties of these collapsed objects and discuss characteristics that might lead to their confirmation as the source of black hole candidate phenomena.

  8. Practical Large Scale Syntheses of New Drug Candidates

    Institute of Scientific and Technical Information of China (English)

    Hui-Yin; Li

    2001-01-01

    This presentation will be focus on Practical large scale syntheses of lead compounds and drug candidates from three major therapeutic areas from DuPont Pharmaceuticals Research Laboratory: 1). DMP777-a selective, non-toxic, orally active human elastase inhibitor; 2). DMP754-a potent glycoprotein IIb/IIIa antagonist; 3). R-Wafarin-the pure enantiomeric form of wafarin. The key technology used for preparation these drug candidates is asymmetric hydrogenation under very mild reaction conditions, which produced very high quality final products at large scale (>99% de, >99 A% and >99 wt%). Some practical and GMP aspects of process development will be also discussed.……

  9. Operational support and analysis a guide for ITIL exam candidates

    CERN Document Server

    Sansbury, John

    2014-01-01

    This user-friendly book aims to assist candidates pass the ITIL® OSA Intermediate examination. It references material from the core ITIL texts and gives practical guidance. This new edition includes the latest ITIL guidance as well as additional insights from the author's own experience of developing effective solutions. An ITIL® licensed product.

  10. Integrated spectral study of reddened globular clusters and candidates

    Science.gov (United States)

    Bica, E.; Claria, J. J.; Piatti, A. E.; Bonatto, C.

    1998-09-01

    This paper presents integrated spectra in the range 6700 - 9500 Angstroms for 20 Galactic globular clusters (and candidates) in the bulge and 5 others projected on the Galactic disk (|l|>30mbox {^{\\circ}}\\ and |b|Complejo Astronómico El Leoncito (CASLEO), Argentina, and European Southern Observatory (ESO), Chile.

  11. Investigation of Teacher Candidates' Learning Styles and Critical Thinking Dispositions

    Directory of Open Access Journals (Sweden)

    Sibel Açışlı

    2015-06-01

    Full Text Available In this study teacher candidates’ learning styles and critical thinking dispositions were investigated. The study group is composed of 938 students attending class teaching and science teaching departments of Artvin Çoruh, Karadeniz Technical, and Recep Tayyip Erdoğan Universities. Colb Learning Styles Inventory and California Critical Thinking Disposition Inventory (CCTDI were used as a means of data-collection. The data were analysed with SPSS 17, and it was detected that there are some differences between the learning styles and critical thinking dispositions of teacher candidates in terms of the variables. It was also observed that 40,9 % of students have "assimilator", 31,2 % of students have "diverger", 15,9 % of students have "converger" , and 11,9 % of students have "accommodator" learning style. The teacher candidates got the highest score from the "being analytical" subscale. As for teacher candidates critical thinking dispositions according to the class levels, a statistically meaningful difference was seen for those attending the final classes only in "open-mindedness" subscale. Upon the analysis of whether teacher candidates critical thinking dispositions differ according to school type variable, a meaningful difference was detected at the subscales of curiosity and seeking for truth while a meaningful difference was not found at the subscales of being analytical, being systematical, and self-confidence.

  12. Supervising PETE Candidates Using the Situational Supervision Model

    Science.gov (United States)

    Levy, Linda S.; Johnson, Lynn V.

    2012-01-01

    Physical education teacher candidates (PETCs) often, as part of their curricular requirements, engage in early field experiences that prepare them for student teaching. Matching the PETC's developmental level with the mentor's supervision style enhances this experience. The situational supervision model, based on the situational leadership model,…

  13. Primary School Teacher Candidates' Geometric Habits of Mind

    Science.gov (United States)

    Köse, Nilu¨fer Y.; Tanisli, Dilek

    2014-01-01

    Geometric habits of mind are productive ways of thinking that support learning and using geometric concepts. Identifying primary school teacher candidates' geometric habits of mind is important as they affect the development of their future students' geometric thinking. Therefore, this study attempts to determine primary school teachers' geometric…

  14. Direct Dark Matter Searches: Fits to WIMP Candidates

    OpenAIRE

    Gelmini, Graciela B.

    2011-01-01

    After a brief introduction to dark matter in general and to WIMPs as candidates, we review recent results of direct dark matter searches. We concentrate on older and more recent hints pointing to light WIMP's with mass below 10 GeV.

  15. Supporting Clinical Practice Candidates in Learning Community Development

    Science.gov (United States)

    DeJarnette, Nancy K.; Sudeck, Maria

    2015-01-01

    The purpose of this qualitative research study was to monitor pre-service teacher candidates' progression and implementation of the learning community philosophy along with classroom management strategies. The study took place during their final semester of clinical practice. Data were collected from self-reports, surveys, university supervisor…

  16. IT Service Management A guide for ITIL Foundation Exam candidates

    CERN Document Server

    Brewster, Ernest; Lawes, Aidan; Sansbury, John

    2012-01-01

    ITIL® is a framework for IT service management and provides best management practice to meet ISO/IEC 20k. This guide introduces ITIL to Foundation Exam candidates and offers a practical understanding of IT service management. The new edition is fully updated and contains several additional processes. An ITIL® licensed product.

  17. Effects of Critical Thinking Intervention for Early Childhood Teacher Candidates

    Science.gov (United States)

    Han, Heejeong Sophia; Brown, E. Todd

    2013-01-01

    This study is based on an intervention designed to enhance early childhood teacher candidates' critical thinking abilities. The concept, elements, standards, and traits of critical thinking were integrated into the main course contents, and the effects of the intervention were examined. The results indicated that early childhood teacher…

  18. Are Teacher and Principal Candidates Prepared to Address Student Cyberbullying?

    Science.gov (United States)

    Styron, Ronald A., Jr.; Bonner, Jessica L.; Styron, Jennifer L.; Bridgeforth, James; Martin, Cecelia

    2016-01-01

    The purpose of this study was to examine the preparation of teacher and principal candidates to address problems created in K-12 settings as a result of cyberbullying. Participants included teacher and principal preparation students. Findings indicated that respondents were familiar with the most common forms of cyberbullying and its impact on…

  19. Documenting Teacher Candidates' Professional Growth through Performance Evaluation

    Science.gov (United States)

    Brown, Elizabeth Levine; Suh, Jennifer; Parsons, Seth A.; Parker, Audra K.; Ramirez, Erin M.

    2015-01-01

    In the United States, colleges of education are responding to demands for increased accountability. The purpose of this article is to describe one teacher education program's implementation of a performance evaluation tool during final internship that measures teacher candidates' development across four domains: Planning and Preparation,…

  20. First microlensing candidates from the MEGA survey of M 31

    NARCIS (Netherlands)

    de Jong, JTA; Kuijken, K; Crotts, APS; Sackett, PD; Sutherland, WJ; Uglesich, RR; Baltz, EA; Cseresnjes, P; Gyuk, G; Widrow, LM

    2004-01-01

    We present the first M 31 candidate microlensing events from the Microlensing Exploration of the Galaxy and Andromeda (MEGA) survey. MEGA uses several telescopes to detect microlensing towards the nearby Andromeda galaxy, M 3 1, in order to establish whether massive compact objects are a significant

  1. Teacher Candidates' Perceptions of Scientists: Images and Attributes

    Science.gov (United States)

    McCarthy, Deborah

    2015-01-01

    The masculine image of scientists as elderly men wearing white coats and glasses, working alone in the laboratory has been documented since the 1950s. Because it is important that teacher candidates have a scientifically literate image of scientists due to the impact they have on their future students, this investigation is salient. This study…

  2. NIR Flare of the AGN Candidate PMNJ0107+0333

    Science.gov (United States)

    Carrasco, L.; Miramon, J.; Recillas, E.; Porras, A.; Chavushyan, V.; Mayya, D. Y.

    2016-12-01

    We report on the new NIR flare of the AGN candidate PMNJ0107+0333, cross identified with the X-ray source 1RXS J010729.5+033341. On November 13th,2016 (MJD 2457705.699), we found the source with the following flux in the NIR band: H = 14.657 +/- 0.05.

  3. Candidate new rotavirus species in sheltered dogs, Hungary.

    Science.gov (United States)

    Mihalov-Kovács, Eszter; Gellért, Ákos; Marton, Szilvia; Farkas, Szilvia L; Fehér, Enikő; Oldal, Miklós; Jakab, Ferenc; Martella, Vito; Bányai, Krisztián

    2015-04-01

    We identified unusual rotavirus strains in fecal specimens from sheltered dogs in Hungary by viral metagenomics. The novel rotavirus species displayed limited genome sequence homology to representatives of the 8 rotavirus species, A-H, and qualifies as a candidate new rotavirus species that we tentatively named Rotavirus I.

  4. Nonequilibrium Candidate Monte Carlo Simulations with Configurational Freezing Schemes.

    Science.gov (United States)

    Giovannelli, Edoardo; Gellini, Cristina; Pietraperzia, Giangaetano; Cardini, Gianni; Chelli, Riccardo

    2014-10-14

    Nonequilibrium Candidate Monte Carlo simulation [Nilmeier et al., Proc. Natl. Acad. Sci. U.S.A. 2011, 108, E1009-E1018] is a tool devised to design Monte Carlo moves with high acceptance probabilities that connect uncorrelated configurations. Such moves are generated through nonequilibrium driven dynamics, producing candidate configurations accepted with a Monte Carlo-like criterion that preserves the equilibrium distribution. The probability of accepting a candidate configuration as the next sample in the Markov chain basically depends on the work performed on the system during the nonequilibrium trajectory and increases with decreasing such a work. It is thus strategically relevant to find ways of producing nonequilibrium moves with low work, namely moves where dissipation is as low as possible. This is the goal of our methodology, in which we combine Nonequilibrium Candidate Monte Carlo with Configurational Freezing schemes developed by Nicolini et al. (J. Chem. Theory Comput. 2011, 7, 582-593). The idea is to limit the configurational sampling to particles of a well-established region of the simulation sample, namely the region where dissipation occurs, while leaving fixed the other particles. This allows to make the system relaxation faster around the region perturbed by the finite-time switching move and hence to reduce the dissipated work, eventually enhancing the probability of accepting the generated move. Our combined approach enhances significantly configurational sampling, as shown by the case of a bistable dimer immersed in a dense fluid.

  5. HMGA1a recognition candidate DNA sequences in humans.

    Directory of Open Access Journals (Sweden)

    Takayuki Manabe

    Full Text Available High mobility group protein A1a (HMGA1a acts as an architectural transcription factor and influences a diverse array of normal biological processes. It binds AT-rich sequences, and previous reports have demonstrated HMGA1a binding to the authentic promoters of various genes. However, the precise sequences that HMGA1a binds to remain to be clarified. Therefore, in this study, we searched for the sequences with the highest affinity for human HMGA1a using an existing SELEX method, and then compared the identified sequences with known human promoter sequences. Based on our results, we propose the sequences "-(G/A-G-(A/T-(A/T-A-T-T-T-" as HMGA1a-binding candidate sequences. Furthermore, these candidate sequences bound native human HMGA1a from SK-N-SH cells. When candidate sequences were analyzed by performing FASTAs against all known human promoter sequences, 500-900 sequences were hit by each one. Some of the extracted genes have already been proven or suggested as HMGA1a-binding promoters. The candidate sequences presented here represent important information for research into the various roles of HMGA1a, including cell differentiation, death, growth, proliferation, and the pathogenesis of cancer.

  6. Candidate eco-friendly gas mixtures for MPGDs

    CERN Document Server

    AUTHOR|(CDS)2071648; Saviano, G.; Muhammad, S.; Piccolo, D.; Primavera, F.; Ferrini, M.; Parvis, M.; Grassing, S.; Colafranceschi, S.; Kjøbro, J.; Sharma, A.; Yang, D.; Chen, G.; Ban, Y.; Li, Q.

    2015-01-01

    Modern gas detectors for detection of particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This review studies properties of potential eco-friendly gas candidate replacements.

  7. Evaluation of Candidate Teachers Related to the Weblog Writing Process

    Science.gov (United States)

    Çelik, Tugba; Demirgünes, Sercan

    2016-01-01

    Weblogs offer a new writing and reading environment. Most people in the education process may improve their writing skills and achieve new perspectives related to writing via weblogs. In this study the changes that weblog writing process created in undergraduates'/candidate teachers' minds regarding writing are revealed. The weblog writing process…

  8. Candidate optical counterparts of MAXI J1543-564

    NARCIS (Netherlands)

    Russell, D.M.; Lewis, F.; Roche, P.; Altamirano, D.

    2011-01-01

    We report on optical observations of the field of the black hole candidate X-ray binary MAXI J1543-564 (ATel #3330, #3331, #3334, #3336, #3341, #3355) with the 2-m Faulkes Telescope South (located at Siding Spring, Australia). Three images were acquired in SDSS i'-band on 2011 May 11th, 14th and 15t

  9. Single Integrated Air Picture (SIAP) Block 1 Candidate Systems

    Science.gov (United States)

    2007-11-02

    to produce joint warfighting capability. Since there was no process for the Single Integrated Air Picture System Engineering Task Force ( SIAP SE TF...to inherit or leverage, the SIAP SE TF had to build a process to identify candidate systems that will be impacted by the SIAP Block I upgrade.

  10. A kinematical selection of glueball candidates in central production

    CERN Document Server

    Barberis, D; Binon, Freddy G; Carney, J N; Close, Francis Edwin; Danielsen, K M; Dolgopolov, A V; Donskov, S V; Earl, B C; Evans, D; French, Bernard R; Inaba, S; Inyakin, A V; Jacholkowski, A; Jacobsen, T; Khaustov, G V; Kinashi, T; Kinson, J B; Kirk, A; Klempt, W; Kobayashi, M; Kondashov, A A; Kulchitskii, Yu A; Lednev, A A; Lenti, V; Maljukov, S; Martinengo, P; Minashvili, I A; Myklebost, K; Nakagawa, T; Norman, K L; Olsen, J M; Peigneux, J P; Polovnikov, S A; Polyakov, V A; Prokoshkin, Yu D; Romanovsky, V I; Rotscheidt, Herbert; Rumyantsev, V; Rusakovitch, N A; Sadovsky, S A; Samoylenko, V D; Semenov, A A; Sené, M; Sené, R; Shagin, P M; Shimizu, H M; Singovsky, A V; Soloviev, A S; Stassinaki, M; Stroot, Jean-Pierre; Sugonyaev, V P; Takamatsu, K; Tchlatchidze, G A; Tsuru, T; Vasileiadis, G; Venables, M; Villalobos Baillie, O; Votruba, M F; Yasu, Y

    1997-01-01

    A study of central meson production as a function of the difference in transverse momentum ($dP_T$) of the exchanged particles shows that undisputed $q \\overline q$ mesons are suppressed at small $dP_T$ whereas the glueball candidates are enhanced.

  11. Quotas and intersectionality: ethnicity and gender in candidate selection

    NARCIS (Netherlands)

    Celis, K.; Erzeel, S.; Mügge, L.; Damstra, A.

    2014-01-01

    Gender equality is not fully realised when it is restricted to ethnic majority men and women. This article examines how gender quotas as a form of equality policy affect ethnic minority groups, in particular, the gender balance among ethnic minority candidates for political office. Our analysis focu

  12. 11 CFR 9003.1 - Candidate and committee agreements.

    Science.gov (United States)

    2010-01-01

    ....1(b)(1). Upon request, documentation explaining the computer system's software capabilities shall be provided, and such personnel as are necessary to explain the operation of the computer system's software... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate and committee agreements....

  13. 11 CFR 9033.1 - Candidate and committee agreements.

    Science.gov (United States)

    2010-01-01

    ... operation of the computer system's software and the computerized information prepared or maintained by the... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate and committee agreements. 9033.1 Section 9033.1 Federal Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN...

  14. How political candidates use Twitter and the impact on votes

    NARCIS (Netherlands)

    Kruikemeier, S.

    2014-01-01

    This study investigates the content characteristics of Twitter during an election campaign, and the relationship between candidates’ style of online campaigning (i.e., politically personalized and interactive communication) and electoral support for those candidates. Thereby, it provides a better un

  15. THE 3 MU-M SPECTRA OF CANDIDATE CARBON STARS

    NARCIS (Netherlands)

    GROENEWEGEN, MAT; DEJONG, T; GEBALLE, TR

    1994-01-01

    We have searched for the 3.1 mum absorption feature, a well-known characteristic of optical carbon stars, in a sample of sixteen candidate carbon stars, most of which have very red colors and some of which have no optical counterparts. The sample was selected on the basis of similarity of LRS spectr

  16. X-ray spectroscopy of a recoiling SMBH candidate

    Science.gov (United States)

    Predehl, Peter

    2008-09-01

    Recent numerical relativity simulations of coalescencing supermassive black hole (SMBH) binaries predict that SMBHs can receive kicks with velocities up to several thousand km/s due to anisotropic emission of gravitational waves. We have recently found the best candidate todate for such a recoiling SMBH (Komossa et al. 2008). We apply for a 25 ks ACIS-S exposure of this exceptional source.

  17. Faculty Meeting: A Simulation for Secondary Teacher Candidates.

    Science.gov (United States)

    Hildebrand, Janet E.

    1981-01-01

    Describes a one-hour simulation used in methods courses at the University of Texas at Austin, to provide secondary teacher candidates with insights into the administrative functioning of a school and their future roles as department and school staff members. (SJL)

  18. Single Transit Candidates from K2: Detection and Period Estimation

    CERN Document Server

    Osborn, H P; Brown, D J A; McCormac, J; Doyle, A P; Louden, T M; Kirk, J; Spake, J J; Lam, K W F; Walker, S R; Faedi, F; Pollacco, D L

    2015-01-01

    Photometric surveys such as Kepler have the precision to identify exoplanet and eclipsing binary candidates from only a single transit. K2, with its 75d campaign duration, is ideally suited to detect significant numbers of single-eclipsing objects. Here we develop a Bayesian transit-fitting tool ("Namaste: An Mcmc Analysis of Single Transit Exoplanets") to extract orbital information from single transit events. We achieve favourable results testing this technique on known Kepler planets, and apply the technique to 7 candidates identified from a targeted search of K2 campaigns 1, 2 and 3. We find EPIC203311200 to host an excellent exoplanet candidate with a period, assuming zero eccentricity, of $540 ^{+410}_{-230}$ days and a radius of $0.51 \\pm 0.05 R_{Jup}$. We also find six further transit candidates for which more follow-up is required to determine a planetary origin. Such a technique could be used in the future with TESS, PLATO and ground-based photometric surveys such as NGTS, potentially allowing the d...

  19. Teacher Candidates' Attitudes to Using Oral History in History Education

    Science.gov (United States)

    Demircioglu, Ebru

    2016-01-01

    The aim of this research is to determine the views of history teacher candidates towards an oral history project carried out in the Special Teaching Method Course of the history pedagogy program of the Fatih Faculty of Education (FFE) at Karadeniz Technical University in Turkey. An open-ended questionnaire and semi-structured interview were the…

  20. Teacher Candidates' Collaboration and Identity in Online Discussions

    Science.gov (United States)

    Bryce, Nadine

    2014-01-01

    In an online context, without facial, verbal or gestural cues, establishing identities through naming social positions appeared essential to effective written communication for graduate pre-service teacher candidates enrolled in a course on literacy education for elementary students. As they engaged in small group asynchronous discussions about…

  1. 11 CFR 110.8 - Presidential candidate expenditure limitations.

    Science.gov (United States)

    2010-01-01

    ... the aggregate of expenditures under this paragraph in any one State shall not exceed the greater of 16... CFR 110.18. (b) The expenditure limitations shall not be considered violated if, after the date of the... expenditure limitation under 11 CFR 9035.1. (d)(1) If an individual is a candidate for more than one...

  2. Recent production of candidate reference materials at IRMM

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, G.N.; Pauwels, J.; Le Guern, L.; Schimmel, H.; Trapmann, S. [Commission of the European Communities, Geel (Belgium). Joint Research Centre

    2001-06-01

    In the execution of its mission to promote a common European measurement system in support of EU policies, IRMM's Reference Materials Unit is currently involved in preparation of proficiency-testing samples and candidate reference materials. Recent work related to bovine spongiform encephalopathy in cows, genetically modified organisms, and a variety of environmental materials is described. (orig.)

  3. Candidate chemosensory genes in the Stemborer Sesamia nonagrioides.

    Science.gov (United States)

    Glaser, Nicolas; Gallot, Aurore; Legeai, Fabrice; Montagné, Nicolas; Poivet, Erwan; Harry, Myriam; Calatayud, Paul-André; Jacquin-Joly, Emmanuelle

    2013-01-01

    The stemborer Sesamia nonagrioides is an important pest of maize in the Mediterranean Basin. Like other moths, this noctuid uses its chemosensory system to efficiently interact with its environment. However, very little is known on the molecular mechanisms that underlie chemosensation in this species. Here, we used next-generation sequencing (454 and Illumina) on different tissues from adult and larvae, including chemosensory organs and female ovipositors, to describe the chemosensory transcriptome of S. nonagrioides and identify key molecular components of the pheromone production and detection systems. We identified a total of 68 candidate chemosensory genes in this species, including 31 candidate binding-proteins and 23 chemosensory receptors. In particular, we retrieved the three co-receptors Orco, IR25a and IR8a necessary for chemosensory receptor functioning. Focusing on the pheromonal communication system, we identified a new pheromone-binding protein in this species, four candidate pheromone receptors and 12 carboxylesterases as candidate acetate degrading enzymes. In addition, we identified enzymes putatively involved in S. nonagrioides pheromone biosynthesis, including a ∆11-desaturase and different acetyltransferases and reductases. RNAseq analyses and RT-PCR were combined to profile gene expression in different tissues. This study constitutes the first large scale description of chemosensory genes in S. nonagrioides.

  4. Many-Objective Distinct Candidates Optimization using Differential Evolution

    DEFF Research Database (Denmark)

    Justesen, Peter; Ursem, Rasmus Kjær

    2010-01-01

    for each objective. The Many-Objective Distinct Candidates Optimization using Differential Evolution (MODCODE) algorithm takes a novel approach by focusing search using a user-defined number of subpopulations each returning a distinct optimal solution within the preferred region of interest. In this paper...

  5. Generating Genome-Scale Candidate Gene Lists for Pharmacogenomics

    DEFF Research Database (Denmark)

    Hansen, Niclas Tue; Brunak, Søren; Altman, R. B.

    2009-01-01

    A critical task in pharmacogenomics is identifying genes that may be important modulators of drug response. High-throughput experimental methods are often plagued by false positives and do not take advantage of existing knowledge. Candidate gene lists can usefully summarize existing knowledge...

  6. Mission Driven Scene Understanding: Candidate Model Training and Validation

    Science.gov (United States)

    2016-09-01

    Services , Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302...driven scene understanding. One of the candidate engines that we are evaluating is a convolutional neural network (CNN) program installed on a Windows 10...environments on scene understanding model results. 15. SUBJECT TERMS computer vision, context, saliency, convolutional neural network , dynamic

  7. Identification of genes from the Treacher Collins candidate region

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, M.; Dixon, J.; Edwards, S. [Univ. of California, Irvine, CA (United States)]|[Univ. of Manchester (United Kingdom)] [and others

    1994-09-01

    Treacher Collins syndrome (TCOF1) is an autosomal dominant disorder of craniofacial development. The TCOF1 locus has previously been mapped to chromosome 5q32-33. The candidate gene region has been defined as being between two flanking markers, ribosomal protein S14 (RPS14) and Annexin 6 (ANX6), by analyzing recombination events in affected individuals. It is estimated that the distance between these flanking markers is 500 kb by three separate analysis methods: (1) radiation hybrid mapping; (2) genetic linkage; and (3) YAC contig analysis. A cosmid contig which spans the candidate gene region for TCOF1 has been constructed by screening the Los Alamos National Laboratory flow-sorted chromosome 5 cosmid library. Cosmids were obtained by using a combination of probes generated from YAC end clones, Alu-PCR fragments from YACs, and asymmetric PCR fragments from both T7 and T3 cosmid ends. Exon amplifications, the selection of genomic coding sequences based upon the presence of functional splice acceptor and donor sites, was used to identify potential exon sequences. Sequences found to be conserved between species were then used to screen cDNA libraries in order to identify candidate genes. To date, four different cDNAs have been isolated from this region and are being analyzed as potential candidate genes for TCOF1. These include the genes encoding plasma glutathione peroxidase (GPX3), heparin sulfate sulfotransferase (HSST), a gene with homology to the ETS family of proteins and one which shows no homology to any known genes. Work is also in progress to identify and characterize additional cDNAs from the candidate gene region.

  8. Discovery of optical candidate supernova remnants in Sagittarius

    Science.gov (United States)

    Alikakos, J.; Boumis, P.; Christopoulou, P. E.; Goudis, C. D.

    2012-08-01

    During an [O III] survey of planetary nebulae, we identified a region in Sagittarius containing several candidate supernova remants (SNRs) and obtained deep optical narrow-band images and spectra to explore their nature. We obtained images of the area of interest by acquiring observations in the emission lines of Hα + [N II], [S II] and [O III]. The resulting mosaic covers an area of 1.4° × 1.0°, where both filamentary and diffuse emission was discovered, suggesting that there is more than one SNR in the area. Deep long-slit spectra were also taken of eight different regions. Both the flux-calibrated images and the spectra show that the emission from the filamentary structures originates from shock-heated gas, while the photo-ionization mechanism is responsible for the diffuse emission. Part of the optical emission is found to be correlated with the radio at 4850 MHz suggesting that they are related, while the infrared emission found in the area at 12 μm and 22 μm marginally correlates with the optical. The presence of the [O III] emission line in one of the candidate SNRs implies that the shock velocities in the interstellar "clouds" are between 120 km s-1 and 200 km s-1, while its absence in the other candidate SNRs indicates that the shock velocities there are slower. For all candidate remnants, the [S II] λλ 6716/6731 ratio indicates that the electron densities are below 240 cm-3, while the Hα emission is measured to be between 0.6 and 41 × 10-17 erg s-1 cm-2 arcsec-2. The existence of eight pulsars within 1.5° of the center of the candidate SNRs also implies that there are many SNRs in the area as well as that the detected optical emission could be part of a number of supernovae explosions.

  9. The Important Candidate Genes in Goats - A Review

    Directory of Open Access Journals (Sweden)

    China SUPAKORN

    2009-01-01

    Full Text Available A total of 271 candidate genes have been detected in goats. However, comprehensive investigations have been carried out on the polymorphism of some genes, involved in the control of economic traits. Candidate genes have an effect on the physiological pathway, metabolism and expression of phenotypes. For growth traits, growth hormone (GH, growth hormone receptor (GHR, insulin like growth factor I (IGF-I, leptin (LEP, caprine pituitary specific transcription factor-1 (POU1F1, caprine myostatin (MSTN and bone morphogenetic protein (BMP genes are necessary for bone formation, birth weight, weaning weight, body condition and muscle growth. For reproduction, forkhead box L 2 (FOXL2, melatonin receptor 1A (MTNR1A, sex determination region of Y chromosome (SRY and amelogenin (AMEL genes influence sex determination and proliferation. The major candidate genes for milk yield and milk composition traits are the casein gene and their family. Keratin associated protein (KAP and melanocortin 1 receptor (MC1R genes are candidate genes for wool traits. The major histocompatibility complex (MHC gene is considered important for the immune system and disease resistance traits. The functions of these genes on economically important traits are different. Some genes have synergistic or antagonistic effects in nature for expression of phenotypic traits. On the other hand, some genes could control more than one trait. Also, the producers should be concerned with these effects because selection of a single trait by using only a gene could affect other traits. Therefore, the identification of candidate genes and their mutations which cause variations of gene expression and phenotype of economic traits will help breeders to search some genetic markers for these economic traits. It may be used as an aid in the selection of parent stock at an early age in the future.

  10. Academic Self-Efficacy Perceptions of Teacher Candidates

    Directory of Open Access Journals (Sweden)

    Dr. Etem YEŞİLYURT

    2013-04-01

    Full Text Available This study aims determining academic self-efficacy perception of teacher candidates. It is survey model. Population of the study consists of teacher candidates in 2010-2011 academic years at Ahmet Keleşoğlu Education Faculty of Education Formation of Selçuk University. A simple random sample was selected as sampling method and the study was conducted on 312 teacher candidates. The data of this study was obtained by “academic selfefficacy scale” which was developed by Jerusalem and Schwazer (1981 and translated into Turkish by Yılmaz, Gürçay, and Ekici (2007 and its reliability value was determined as .79. However, Cronbach Alfa reliability value of this scale became .76 with the result of the data analysis of the study. SPSS package program was used to analyze the data; and the data analysis, frequency, percentage, arithmetic mean, standard deviation, independent samples t-test, one-way analysis of variance (ANOVA and post hoc tests (LSD test were used. When the findings of the research were considered in general, the result showed that the academic self-efficacy perception level of the candidates was at desired level. However, teachers' views about the level of academic self-efficacy perception showed that most of them preferred a lower level option "suits me", instead of "totally suits me" option that was the highest degree of participation of four likert-type scale. This illustrated that their perception about this issue was not at a very high level. When independent variables were taken into account, among the academic perception levels of teacher candidates, a significant difference was detected in terms of working as a teacher or not and academic achievement variables but it revealed no significant difference in terms of gender and type of education program variables.

  11. Identification of candidate genome regions controlling disease resistance in Arachis

    Directory of Open Access Journals (Sweden)

    Pike Jodie

    2009-08-01

    Full Text Available Abstract Background Worldwide, diseases are important reducers of peanut (Arachis hypogaea yield. Sources of resistance against many diseases are available in cultivated peanut genotypes, although often not in farmer preferred varieties. Wild species generally harbor greater levels of resistance and even apparent immunity, although the linkage of agronomically un-adapted wild alleles with wild disease resistance genes is inevitable. Marker-assisted selection has the potential to facilitate the combination of both cultivated and wild resistance loci with agronomically adapted alleles. However, in peanut there is an almost complete lack of knowledge of the regions of the Arachis genome that control disease resistance. Results In this work we identified candidate genome regions that control disease resistance. For this we placed candidate disease resistance genes and QTLs against late leaf spot disease on the genetic map of the A-genome of Arachis, which is based on microsatellite markers and legume anchor markers. These marker types are transferable within the genus Arachis and to other legumes respectively, enabling this map to be aligned to other Arachis maps and to maps of other legume crops including those with sequenced genomes. In total, 34 sequence-confirmed candidate disease resistance genes and five QTLs were mapped. Conclusion Candidate genes and QTLs were distributed on all linkage groups except for the smallest, but the distribution was not even. Groupings of candidate genes and QTLs for late leaf spot resistance were apparent on the upper region of linkage group 4 and the lower region of linkage group 2, indicating that these regions are likely to control disease resistance.

  12. Shigella sonnei Vaccine Candidates WRSs2 and WRSs3 Are as Immunogenic as WRSS1, a Clinically Tested Vaccine Candidate, in a Primate Model of Infection

    Science.gov (United States)

    2011-01-01

    Please cite this article in press as: Barnoy S, et al. Shigella sonnei vaccine candidates WRSs2 and WRSs3 are as immunogenic as WRSS1, a clinically... Shigella sonnei vaccine candidates WRSs2 and WRSs3 are as immunogenic as WRSS1, a clinically tested vaccine candidate, in a primate...o Article history: Received 15 October 2010 Accepted 28 April 2011 Available online Keywords: Shigella sonnei Live vaccine candidates WRSs2

  13. The CHAOS-3 Geomagnetic Field Model and Candidates for the 11th Generation IGRF

    DEFF Research Database (Denmark)

    Olsen, Nils; Mandea, Mioara; Sabaka, Terence J.

    2010-01-01

    As a part of the 11th generation IGRF defined by IAGA, we propose a candidate model for the DGRF 2005, a candidate model for IGRF 2010 and a candidate model for the mean secular variation between 2010 and 2015. These candidate models, the derivation of which is described in the following, are bas...

  14. Framing the Candidates in Presidential Primaries: Issues and Images in Press Releases and News Coverage.

    Science.gov (United States)

    Miller, M. Mark; Andsager, Julie L.; Riechert, Bonnie P.

    1998-01-01

    Contributes to research on political communication by examining how 1996 GOP presidential candidates framed themselves in press releases and how elite newspapers covered them. Shows that candidate images were distinct in press releases and news stories; candidate positions were represented differently in both; and candidates were differentially…

  15. Comparing What Teacher Candidates Know about Each Other: China and the United States

    Science.gov (United States)

    Xu, Tingting; Byker, Erik Jon; Chen, Juan

    2016-01-01

    The purpose of this article is to compare teacher candidates' knowledge and perceptions about China and the United States. Using a survey research design, 91 Chinese teacher candidates and 96 teacher candidates from the United Sates participated. The survey findings indicated that, while both groups of teacher candidates had a basic level of…

  16. A Research on the Burnout and the Teaching Profession Attitudes of Teacher Candidates

    Science.gov (United States)

    Kadi, Aysegül; Beytekin, Osman Ferda; Arslan, Hasan

    2015-01-01

    Purpose of this study is to examine burnout and teaching profession attitudes of teacher candidates. Research was conducted with 287 teacher candidates. By the findings; burnout and teaching profession attitudes of teacher candidates don't differ according to their gender. Burnout of teacher candidates differs according to their graduation status…

  17. Robo-AO Kepler Planetary Candidate Survey II: Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars

    CERN Document Server

    Baranec, Christoph; Law, Nicholas M; Morton, Tim; Riddle, Reed; Atkinson, Dani; Schonhut, Jessica; Crepp, Justin

    2016-01-01

    We initiated the Robo-AO Kepler Planetary Candidate Survey in 2012 to observe each Kepler exoplanet candidate host star with high-angular-resolution visible-light laser-adaptive-optics imaging. Our goal is to find nearby stars lying in Kepler's photometric apertures that are responsible for the relatively high probability of false-positive exoplanet detections and that cause underestimates of the size of transit radii. Our comprehensive survey will also shed light on the effects of stellar multiplicity on exoplanet properties and will identify rare exoplanetary architectures. In this second part of our ongoing survey, we observed an additional 969 Kepler planet candidate hosts and we report blended stellar companions up to $\\Delta m \\approx 6$ that contribute to Kepler's measured light curves. We found 203 companions within $\\sim$4" of 181 of the Kepler stars, of which 141 are new discoveries. We measure the nearby-star probability for this sample of Kepler planet candidate host stars to be 10.6% $\\pm$ 1.1% a...

  18. Automatic extraction of candidate nomenclature terms using the doublet method

    Directory of Open Access Journals (Sweden)

    Berman Jules J

    2005-10-01

    Full Text Available Abstract Background New terminology continuously enters the biomedical literature. How can curators identify new terms that can be added to existing nomenclatures? The most direct method, and one that has served well, involves reading the current literature. The scholarly curator adds new terms as they are encountered. Present-day scholars are severely challenged by the enormous volume of biomedical literature. Curators of medical nomenclatures need computational assistance if they hope to keep their terminologies current. The purpose of this paper is to describe a method of rapidly extracting new, candidate terms from huge volumes of biomedical text. The resulting lists of terms can be quickly reviewed by curators and added to nomenclatures, if appropriate. The candidate term extractor uses a variation of the previously described doublet coding method. The algorithm, which operates on virtually any nomenclature, derives from the observation that most terms within a knowledge domain are composed entirely of word combinations found in other terms from the same knowledge domain. Terms can be expressed as sequences of overlapping word doublets that have more specific meaning than the individual words that compose the term. The algorithm parses through text, finding contiguous sequences of word doublets that are known to occur somewhere in the reference nomenclature. When a sequence of matching word doublets is encountered, it is compared with whole terms already included in the nomenclature. If the doublet sequence is not already in the nomenclature, it is extracted as a candidate new term. Candidate new terms can be reviewed by a curator to determine if they should be added to the nomenclature. An implementation of the algorithm is demonstrated, using a corpus of published abstracts obtained through the National Library of Medicine's PubMed query service and using "The developmental lineage classification and taxonomy of neoplasms" as a reference

  19. Short period eclipsing binary candidates identified using SuperWASP

    CERN Document Server

    Norton, A J; Evans, T; West, R G; Wheatley, P J; Anderson, D R; Barros, S C C; Butters, O W; Cameron, A Collier; Christian, D J; Enoch, B; Faedi, F; Haswell, C A; Hellier, C; Holmes, S; Horne, K D; Lister, T A; Maxted, P F L; Parley, N; Pollacco, D; Simpson, E K; Skillen, I; Smalley, B; Southworth, J; Street, R A

    2011-01-01

    We present light curves and periods of 53 candidates for short period eclipsing binary stars identified by SuperWASP. These include 48 newly identified objects with periods <2x10^4 seconds (~0.23d), as well as the shortest period binary known with main sequence components (GSC2314-0530 = 1SWASP J022050.85+332047.6) and four other previously known W UMa stars (although the previously reported periods for two of these four are shown to be incorrect). The period distribution of main sequence contact binaries shows a sharp cut-off at a lower limit of around 0.22d, but until now, very few systems were known close to this limit. These new candidates will therefore be important for understanding the evolution of low mass stars and to allow investigation of the cause of the period cut-off.

  20. A novel live-attenuated vaccine candidate for mayaro Fever.

    Directory of Open Access Journals (Sweden)

    William J Weise

    2014-08-01

    Full Text Available Mayaro virus (MAYV is an emerging, mosquito-borne alphavirus that causes a dengue-like illness in many regions of South America, and which has the potential to urbanize. Because no specific treatment or vaccine is available for MAYV infection, we capitalized on an IRES-based approach to develop a live-attenuated MAYV vaccine candidate. Testing in infant, immunocompetent as well as interferon receptor-deficient mice demonstrated a high degree of attenuation, strong induction of neutralizing antibodies, and efficacy against lethal challenge. This vaccine strain was also unable to infect mosquito cells, a major safety feature for a live vaccine derived from a mosquito-borne virus. Further preclinical development of this vaccine candidate is warranted to protect against this important emerging disease.

  1. An improved catalog of halo wide binary candidates

    CERN Document Server

    Allen, Christine

    2014-01-01

    We present an improved catalog of halo wide binaries, compiled from an extensive literature search. Most of our binaries stem from the common proper motion binary catalogs by Allen et al. (2004), and Chanam\\'e \\& Gould. (2004) but we have also included binaries from the lists of Ryan (1992) and Zapatero-Osorio \\& Martin (2004). All binaries were carefully checked and their distances and systemic radial velocities are included, when available. Probable membership to the halo population was tested by means of reduced proper motion diagrams for 251 candidate halo binaries. After eliminating obvious disk binaries we ended up with 211 probable halo binaries, for 150 of which radial velocities are available. We compute galactic orbits for these 150 binaries and calculate the time they spend within the galactic disk. Considering the full sample of 251 candidate halo binaries as well as several subsamples, we find that the distribution of angular separations (or expected major semiaxes) follows a power law $f...

  2. Vaccine Candidates against Nontypeable Haemophilus influenzae: a Review

    Science.gov (United States)

    Behrouzi, Ava; Vaziri, Farzam; Rahimi-Jamnani, Fatemeh; Afrough, Parviz; Rahbar, Mohammad; Satarian, Fereshteh; Siadat, Seyed Davar

    2017-01-01

    Nonencapsulated, nontypeable Hemophilus influenzae (NTHi) remains an important cause of acute otitis and respiratory diseases in children and adults. NTHi bacteria are one of the major causes of respiratory tract infections, including acute otitis media, cystic fibrosis, and community-acquired pneumonia among children, especially in developing countries. The bacteria can also cause chronic diseases such as chronic bronchitis and chronic obstructive pulmonary disease in the lower respiratory tract of adults. Such bacteria express several outer membrane proteins, some of which have been studied as candidates for vaccine development. Due to the lack of effective vaccines as well as the spread and prevalence of NTHi worldwide, there is an urgent need to design and develop effective vaccine candidates against these strains. PMID:28088130

  3. A novel live-attenuated vaccine candidate for mayaro Fever.

    Science.gov (United States)

    Weise, William J; Hermance, Meghan E; Forrester, Naomi; Adams, A Paige; Langsjoen, Rose; Gorchakov, Rodion; Wang, Eryu; Alcorn, Maria D H; Tsetsarkin, Konstantin; Weaver, Scott C

    2014-08-01

    Mayaro virus (MAYV) is an emerging, mosquito-borne alphavirus that causes a dengue-like illness in many regions of South America, and which has the potential to urbanize. Because no specific treatment or vaccine is available for MAYV infection, we capitalized on an IRES-based approach to develop a live-attenuated MAYV vaccine candidate. Testing in infant, immunocompetent as well as interferon receptor-deficient mice demonstrated a high degree of attenuation, strong induction of neutralizing antibodies, and efficacy against lethal challenge. This vaccine strain was also unable to infect mosquito cells, a major safety feature for a live vaccine derived from a mosquito-borne virus. Further preclinical development of this vaccine candidate is warranted to protect against this important emerging disease.

  4. Pedophiles and stalkers as transplant candidates: one program's experience.

    Science.gov (United States)

    Paris, Wayne; Miller, Rachel; Hille, Cheryl; Nour, Bakr; Griggs, Johnny

    2005-12-01

    Transplant assessment of pedophiles and stalkers presents a challenge for clinicians and requires the ability to separate the science from the hysteria. Although rarely seen in organ transplant clinics, the presence of psychosexual disorders can result in both criminal charges and harsh societal reactions. Clinicians must be able to assess and make informed recommendations about the suitability of the candidate and any potential risks for staff, other patients, and society at large. Six patients (5 pedophiles and 1 stalker) were assessed at our major regional multiorgan transplant program; each patient presented with unique and challenging assessment, treatment, and selection issues for the transplant team. The objectives of this article are to raise awareness of the issues associated with pedophiles and stalkers, and to provide the basis for better-informed discussions based on one program's struggles with its candidate selection and follow-up.

  5. On the Low False Positive Probabilities of Kepler Planet Candidates

    CERN Document Server

    Morton, Timothy D

    2011-01-01

    We present a framework to conservatively estimate the probability that any particular planet-like transit signal observed by the Kepler mission is in fact a planet, prior to any ground-based follow-up efforts. We use Monte Carlo methods based on stellar population synthesis and Galactic structure models, and we provide empirical analytic fits to our results that may be applied to the as-yet-unconfirmed Kepler candidates. We find that the false positive probability for candidates that pass preliminary Kepler vetting procedures is generally 20% to < 2%, assuming a continuous power law for the planet mass function with index alpha = -1.5. Since Kepler will detect many more planetary signals than can be positively confirmed with ground-based follow-up efforts in the near term, these calculations will be crucial to using the ensemble of Kepler data to determine population characteristic s of planetary systems.

  6. PTPS Candidate Exoplanet Host Star Radii Determination with CHARA Array

    CERN Document Server

    Zielinski, Pawel; Baines, Ellyn; Niedzielski, Andrzej; Wolszczan, Aleksander

    2012-01-01

    We propose to measure the radii of the Penn State - Torun Planet Search (PTPS) exoplanet host star candidates using the CHARA Array. Stellar radii estimated from spectroscopic analysis are usually inaccurate due to indirect nature of the method and strong evolutionary model dependency. Also the so-called degeneracy of stellar evolutionary tracks due to convergence of many tracks in the giant branch decreases the precision of such estimates. However, the radius of a star is a critical parameter for the calculation of stellar luminosity and mass, which are often not well known especially for giants. With well determined effective temperature (from spectroscopy) and radius the luminosity may be calculated precisely. In turn also stellar mass may be estimated much more precisely. Therefore, direct radii measurements increase precision in the determination of planetary candidates masses and the surface temperatures of the planets.

  7. Scaling laws and universality in the choice of election candidates

    CERN Document Server

    Mantovani, M C; Moro, M V; Picoli, S; Mendes, R S

    2011-01-01

    Nowadays there is an increasing interest of physicists in finding regularities related to social phenomena. This interest is clearly motivated by applications that a statistical mechanical description of the human behavior may have in our society. By using this framework, we address this work to cover an open question related to elections: the choice of elections candidates (candidature process). Our analysis reveals that, apart from the social motivations, this system displays features of traditional out-of-equilibrium physical phenomena such as scale-free statistics and universality. Basically, we found a non-linear (power law) mean correspondence between the number of candidates and the size of the electorate (number of voters), and also that this choice has a multiplicative underlying process (lognormal behavior). The universality of our findings is supported by data from 16 elections from 5 countries. In addition, we show that aspects of network scale-free can be connected to this universal behavior.

  8. The cavefish genome reveals candidate genes for eye loss

    Science.gov (United States)

    McGaugh, Suzanne E.; Gross, Joshua B.; Aken, Bronwen; Blin, Maryline; Borowsky, Richard; Chalopin, Domitille; Hinaux, Hélène; Jeffery, William R.; Keene, Alex; Ma, Li; Minx, Patrick; Murphy, Daniel; O’Quin, Kelly E.; Rétaux, Sylvie; Rohner, Nicolas; Searle, Steve M. J.; Stahl, Bethany A.; Tabin, Cliff; Volff, Jean-Nicolas; Yoshizawa, Masato; Warren, Wesley C.

    2014-01-01

    Natural populations subjected to strong environmental selection pressures offer a window into the genetic underpinnings of evolutionary change. Cavefish populations, Astyanax mexicanus (Teleostei: Characiphysi), exhibit repeated, independent evolution for a variety of traits including eye degeneration, pigment loss, increased size and number of taste buds and mechanosensory organs, and shifts in many behavioural traits. Surface and cave forms are interfertile making this system amenable to genetic interrogation; however, lack of a reference genome has hampered efforts to identify genes responsible for changes in cave forms of A. mexicanus. Here we present the first de novo genome assembly for Astyanax mexicanus cavefish, contrast repeat elements to other teleost genomes, identify candidate genes underlying quantitative trait loci (QTL), and assay these candidate genes for potential functional and expression differences. We expect the cavefish genome to advance understanding of the evolutionary process, as well as, analogous human disease including retinal dysfunction. PMID:25329095

  9. A thermodynamic approach to the affinity optimization of drug candidates.

    Science.gov (United States)

    Freire, Ernesto

    2009-11-01

    High throughput screening and other techniques commonly used to identify lead candidates for drug development usually yield compounds with binding affinities to their intended targets in the mid-micromolar range. The affinity of these molecules needs to be improved by several orders of magnitude before they become viable drug candidates. Traditionally, this task has been accomplished by establishing structure activity relationships to guide chemical modifications and improve the binding affinity of the compounds. As the binding affinity is a function of two quantities, the binding enthalpy and the binding entropy, it is evident that a more efficient optimization would be accomplished if both quantities were considered and improved simultaneously. Here, an optimization algorithm based upon enthalpic and entropic information generated by Isothermal Titration Calorimetry is presented.

  10. Planetary transit candidates in COROT-IRa01 field

    CERN Document Server

    Carpano, S; Alonso, R; Barge, P; Aigrain, S; Almenara, J -M; Bordé, P; Bouchy, F; Carone, L; Deeg, H J; De la Reza, R; Deleuil, M; Dvorak, R; Erikson, A; Fressin, F; Fridlund, M; Gondoin, P; Guillot, T; Hatzes, A; Jorda, L; Lammer, H; Léger, A; Llebaria, A; Magain, P; Moutou, C; Ofir, A; Ollivier, M; Pacheco, E J; Pátzold, M; Pont, F; Queloz, D; Rauer, H; Régulo, C; Renner, S; Rouan, D; Samuel, B; Schneider, J; Wuchterl, G

    2009-01-01

    Context: CoRoT is a pioneering space mission devoted to the analysis of stellar variability and the photometric detection of extrasolar planets. Aims: We present the list of planetary transit candidates detected in the first field observed by CoRoT, IRa01, the initial run toward the Galactic anticenter, which lasted for 60 days. Methods: We analysed 3898 sources in the coloured bands and 5974 in the monochromatic band. Instrumental noise and stellar variability were taken into account using detrending tools before applying various transit search algorithms. Results: Fifty sources were classified as planetary transit candidates and the most reliable 40 detections were declared targets for follow-up ground-based observations. Two of these targets have so far been confirmed as planets, COROT-1b and COROT-4b, for which a complete characterization and specific studies were performed.

  11. Determination of candidate subjects for better recognition of faces

    Science.gov (United States)

    Wang, Xuansheng; Chen, Zhen; Teng, Zhongming

    2016-05-01

    In order to improve the accuracy of face recognition and to solve the problem of various poses, we present an improved collaborative representation classification (CRC) algorithm using original training samples and the corresponding mirror images. First, the mirror images are generated from the original training samples. Second, both original training samples and their mirror images are simultaneously used to represent the test sample via improved collaborative representation. Then, some classes which are "close" to the test sample are coarsely selected as candidate classes. At last, the candidate classes are used to represent the test sample again, and then the class most similar to the test sample can be determined finely. The experimental results show our proposed algorithm has more robustness than the original CRC algorithm and can effectively improve the accuracy of face recognition.

  12. Moving candidate vaccines into development from research: lessons from HIV.

    Science.gov (United States)

    Sullivan, Mark

    2009-07-01

    There is a logarithmic increase in the cost and complexity of the research and development process when transitioning a promising candidate vaccine from the laboratory into the clinic. Managing complex development programs involving people from diverse technical, cultural and geographical backgrounds is a specialised skill. It is essential that the group is clear on their objectives and how their activities affect others, that communication is open, inclusive and effective, and that the most rigorous, scientific approach based on statistical principles in compliance with regulatory requirements is used. Applying these standards to all vaccine development programs will filter out inappropriate candidates more readily and enhance the efficiency of vaccine development. The challenges of developing a new vaccine are illustrated in human immunodeficiency virus (HIV) vaccinology. Selecting vaccine candidates for HIV requires the ability to evaluate the large number of potential antigens in imperfect and non-standardised animal models. Further, using these models to evaluate questions such as dose scaling to humans, optimal route of administration, the use of adjuvants and potential formulation improvements adds variable to variable, making the interpretation of results particularly challenging. This may lead to the promotion of a poor candidate or the elimination of a good one. The absence of precise immunological correlates of protection and the prohibitive cost of confirmatory clinical trials are further significant barriers. However, there are practical steps that can be taken to standardise early vaccine evaluation, which would result in more efficient development of new vaccines for HIV and other disease areas with similarly challenging development issues (such as hepatitis C virus, influenza, Mycobacterium tuberculosis and malaria).

  13. Identification of new transitional disk candidates in Lupus with Herschel

    Science.gov (United States)

    Bustamante, I.; Merín, B.; Ribas, Á.; Bouy, H.; Prusti, T.; Pilbratt, G. L.; André, Ph.

    2015-06-01

    Context. New data from the Herschel Space Observatory are broadening our understanding of the physics and evolution of the outer regions of protoplanetary disks in star-forming regions. In particular they prove to be useful for identifying transitional disk candidates. Aims: The goals of this work are to complement the detections of disks and the identification of transitional disk candidates in the Lupus clouds with data from the Herschel Gould Belt Survey. Methods: We extracted photometry at 70, 100, 160, 250, 350, and 500 μm of all spectroscopically confirmed Class II members previously identified in the Lupus regions and analyzed their updated spectral energy distributions. Results: We have detected 34 young disks in Lupus in at least one Herschel band, from an initial sample of 123 known members in the observed fields. Using recently defined criteria, we have identified five transitional disk candidates in the region. Three of them are new to the literature. Their PACS-70 μm fluxes are systematically higher than those of normal T Tauri stars in the same associations, as already found in T Cha and in the transitional disks in the Chamaeleon molecular cloud. Conclusions: Herschel efficiently complements mid-infrared surveys for identifying transitional disk candidates and confirms that these objects seem to have substantially different outer disks than the T Tauri stars in the same molecular clouds. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables 5-7 and Figs. 3 and 4 are available in electronic form at http://www.aanda.org

  14. Production and characterization of a bovine liver candidate reference material

    Science.gov (United States)

    Bianchi, S. R.; Peixoto, A. M. J.; Souza, G. B.; Tullio, R. R.; Nogueira, A. R. A.

    2016-07-01

    The preparation of a bovine liver candidate reference material and the steps are taken to confirm its homogeneity, long and short term stabilities, and consensus values are described. Details of the sample preparation and the final collaborative exercise are presented. The material elemental composition was characterized by 17 elements (As, Ca, Cd, Co, Cu, Fe, K, Mg, Mo, Mn, Na, P, Pb, Se, Sr, V, and Zn) of nutritional and toxicological significance.

  15. Detection of candidal antigens in autoimmune polyglandular syndrome type I.

    OpenAIRE

    Peterson, P; Perheentupa, J; Krohn, K J

    1996-01-01

    Autoimmune polyglandular syndrome type I (APS I) is associated with chronic mucocutaneous candidiasis. To characterize the antibody responses in this subgroup of Candida albicans infections, we screened a candidal cDNA expression library with patient sera and found four cDNA clones encoding the immunopositive proteins enolase, heat shock protein 90, pyruvate kinase, and alcohol dehydrogenase. The reactivity to these antigens was studied further by immunoprecipitation assays with in vitro-tran...

  16. Three new optical nova candidates in M 31

    Science.gov (United States)

    Pietsch, W.; Henze, M.; Burwitz, V.; Kaur, A.; Hartmann, D. H.; Williams, G.; Milne, P.

    2011-06-01

    We report the discovery of three nova candidates in M 31 on 7x60s stacked R filter CCD images obtained with the robotic 60cm telescope with an E2V CCD (2kx2k, 13.5 micron sq. pixels) of the Livermore Optical Transient Imaging System (Super-LOTIS, located at Steward Observatory, Kitt Peak, Arizona, USA) on 2011 June 7.418 UT. The objects are visible on all individual images.

  17. Consortium analysis of 7 candidate SNPs for ovarian cancer

    DEFF Research Database (Denmark)

    Ramus, S.J.; Vierkant, R.A.; Johnatty, S.E.

    2008-01-01

    The Ovarian Cancer Association Consortium selected 7 candidate single nucleotide polymorphisms (SNPs), for which there is evidence from previous studies of an association with variation in ovarian cancer or breast cancer risks. The SNPs selected for analysis were F31I (rs2273535) in AURKA, N372H...... for SNPs identified from relatively large initial studies shows the importance of replicating associations by a consortium approach Udgivelsesdato: 2008/7/15...

  18. Searches for millisecond pulsar candidates among the unidentified Fermi objects

    CERN Document Server

    Hui, C Y; Hu, C P; Lin, L C C; Li, K L; Kong, A K H; Tam, P H T; Takata, J; Cheng, K S; Jin, Ruolan; Yen, T -C; Kim, Chunglee

    2015-01-01

    Here we report the results of searching millisecond pulsar (MSP) candidates from the Fermi LAT second source catalog (2FGL). Seven unassociated $\\gamma-$ray sources in this catalog are identified as promising MSP candidates based on their $\\gamma$-ray properties. Through the X-ray analysis, we have detected possible X-ray counterparts, localized to an arcsecond accuracy. We have systematically estimated their X-ray fluxes and compared with the corresponding $\\gamma$-ray fluxes. The X-ray to $\\gamma$-ray flux ratios for 2FGL J1653.6-0159 and 2FGL J1946.4-5402 are comparable with the typical value for pulsars. For 2FGL J1625.2-0020, 2FGL J1653.6-0159 and 2FGL J1946.4-5402, their candidate X-ray counterparts are bright enough for performing a detailed spectral and temporal analysis to discriminate their thermal/non thermal nature and search for the periodic signal. We have also searched for possible optical/IR counterparts at the X-ray positions. For the optical/IR source coincident with the brightest X-ray obje...

  19. Five Kepler target stars that show multiple transiting exoplanet candidates

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Buchhave, Lars A.; /Harvard-Smithsonian Ctr. Astrophys. /Bohr Inst.; Caldwell, Douglas A.; /NASA, Ames /SETI Inst., Mtn. View; Cochran, William D.; /Texas U.; Endl, Michael; /Texas U.; Fabrycky, Daniel C.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Ford, Eric B.; /Florida U.; Fortney, Jonathan J.; /UC, Santa Cruz, Phys. Dept. /NASA, Ames

    2010-06-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets and provide new insights into the formation and dynamical evolution of planetary systems. We discuss the methods used to identify multiple transiting objects from the Kepler photometry as well as the false-positive rejection methods that have been applied to these data. One system shows transits from three distinct objects while the remaining four systems show transits from two objects. Three systems have planet candidates that are near mean motion commensurabilities - two near 2:1 and one just outside 5:2. We discuss the implications that multitransiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories; as well as their likely masses and chemical compositions. A Monte Carlo study indicates that, with additional data, most of these systems should exhibit detectable transit timing variations (TTV) due to gravitational interactions - though none are apparent in these data. We also discuss new challenges that arise in TTV analyses due to the presence of more than two planets in a system.

  20. Candidate Disk Wide Binaries in the Sloan Digital Sky Survey

    CERN Document Server

    Sesar, Branimir; Juric, Mario

    2008-01-01

    Using SDSS Data Release 6, we construct two independent samples of candidate stellar wide binaries selected as i) pairs of unresolved sources with angular separation in the range 3'' - 16'', ii) common proper motion pairs with 5'' - 30'' angular separation, and make them publicly available. These samples are dominated by disk stars, and we use them to constrain the shape of the main-sequence photometric parallax relation M_r(r-i) and to study the properties of wide binary systems. We estimate M_r(r-i) by searching for a relation that minimizes the difference between distance moduli of primary and secondary components of wide binary candidates. We model M_r(r-i) by a fourth degree polynomial and determine the coefficients using Markov Chain Monte Carlo fitting, independently for each sample. Aided by the derived photometric parallax relation, we construct a series of high-quality catalogs of candidate main-sequence binary stars. Using these catalogs, we study the distribution of semi-major axes of wide binarie...

  1. Five Kepler Target Stars That Show Multiple Transiting Exoplanet Candidates

    Science.gov (United States)

    Steffen, Jason H.; Batalha, Natalie M.; Borucki, William J.; Buchhave, Lars A.; Caldwell, Douglas A.; Cochran, William D.; Endl, Michael; Fabrycky, Daniel C.; Fressin, François; Ford, Eric B.; Fortney, Jonathan J.; Haas, Michael J.; Holman, Matthew J.; Howell, Steve B.; Isaacson, Howard; Jenkins, Jon M.; Koch, David; Latham, David W.; Lissauer, Jack J.; Moorhead, Althea V.; Morehead, Robert C.; Marcy, Geoffrey; MacQueen, Phillip J.; Quinn, Samuel N.; Ragozzine, Darin; Rowe, Jason F.; Sasselov, Dimitar D.; Seager, Sara; Torres, Guillermo; Welsh, William F.

    2010-12-01

    We present and discuss five candidate exoplanetary systems identified with the Kepler spacecraft. These five systems show transits from multiple exoplanet candidates. Should these objects prove to be planetary in nature, then these five systems open new opportunities for the field of exoplanets and provide new insights into the formation and dynamical evolution of planetary systems. We discuss the methods used to identify multiple transiting objects from the Kepler photometry as well as the false-positive rejection methods that have been applied to these data. One system shows transits from three distinct objects while the remaining four systems show transits from two objects. Three systems have planet candidates that are near mean motion commensurabilities—two near 2:1 and one just outside 5:2. We discuss the implications that multi-transiting systems have on the distribution of orbital inclinations in planetary systems, and hence their dynamical histories, as well as their likely masses and chemical compositions. A Monte Carlo study indicates that, with additional data, most of these systems should exhibit detectable transit timing variations (TTVs) due to gravitational interactions, though none are apparent in these data. We also discuss new challenges that arise in TTV analyses due to the presence of more than two planets in a system.

  2. TIME SERIES FORECASTING WITH MULTIPLE CANDIDATE MODELS: SELECTING OR COMBINING?

    Institute of Scientific and Technical Information of China (English)

    YU Lean; WANG Shouyang; K. K. Lai; Y.Nakamori

    2005-01-01

    Various mathematical models have been commonly used in time series analysis and forecasting. In these processes, academic researchers and business practitioners often come up against two important problems. One is whether to select an appropriate modeling approach for prediction purposes or to combine these different individual approaches into a single forecast for the different/dissimilar modeling approaches. Another is whether to select the best candidate model for forecasting or to mix the various candidate models with different parameters into a new forecast for the same/similar modeling approaches. In this study, we propose a set of computational procedures to solve the above two issues via two judgmental criteria. Meanwhile, in view of the problems presented in the literature, a novel modeling technique is also proposed to overcome the drawbacks of existing combined forecasting methods. To verify the efficiency and reliability of the proposed procedure and modeling technique, the simulations and real data examples are conducted in this study.The results obtained reveal that the proposed procedure and modeling technique can be used as a feasible solution for time series forecasting with multiple candidate models.

  3. Candidate tidal dwarf galaxies associated with the Stephan's Quintet

    CERN Document Server

    De Oliveira, C M; Amram, P; Balkowski, C; Bolte, M

    2001-01-01

    We present kinematic and photometric evidence for the presence of seven candidate tidal dwarf galaxies in Stephan's quintet. The central regions of the two most probable parent galaxies, N7319 and N7318B, contain little or no gas whereas the intragroup medium, and particularly the optical tails that seem to be associated with N7318B are rich in cold and ionized gas. Two tidal-dwarf candidates may be located at the edge of a tidal tail, one within a tail and for four others there is no obvious stellar/gaseous bridge between them and the parent galaxy. Two of the candidates are associated with HI clouds, one of which is, in addition, associated with a CO cloud. All seven regions have low continuum fluxes and high H$\\alpha$ luminosity densities (F(H$\\alpha$) = 1 -- 60 $\\times$ 10$^{-14}$ erg s$^{-1}$ cm$^{-2}$). Their magnitudes (M$_B =$ --16.1 to --12.6), sizes ($\\sim$ 3.5 h$_{75}^{-1}$ kpc), colors (typically $B-R = 0.7$) and gas velocity gradients ($\\sim$ 8 -- 26 h$_{75}$ km s$^{-1}$ kpc$^{-1}$) are typical f...

  4. Pulmonary Rehabilitation in Lung Transplant Candidates: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Stefanie Tonguino Rosero

    2013-09-01

    Full Text Available Pulmonary rehabilitation (PR aims to improve physical fitness and to decrease symptoms in patients with chronic lung disease; however there is not clear evidence regarding the benefits of PR in candidates for lung transplantation (LT. Objective. To determine the effectiveness of PR in LT candidates and also to find out how quality of life and exercise tolerance affects the survival of these patients. Methodology. Electronic databases (Medline, Cochrane, PEDro, Scient Direct and SciELO Search of articles in spanish, english or portuguese; controlled clinical trials and cohort studies published between 2000-2011 regarding PR in candidates for LT, the model of Cochrane systematic reviews was used. Results. The papers included were four cohort, two of which regarded of survival pre LT using the six minutes walking test (6MWT; a study of quality of life related to post LT survival and an exercise tolerance study. Controlled clinical trial was not found. Conclusions. The information found in the included studies had clinical and methodological heterogeneity therefore a meta-analysis could not been undertaken. The PR should be considered as an essential part to maintain the exercise tolerance and the patient’s survival. Research regarding this subject is important and should be carried out.

  5. Runaway M Dwarf Candidates from the Sloan Digital Sky Survey

    CERN Document Server

    Favia, Andrej; Theissen, Christopher A

    2015-01-01

    We present a sample of 20 runaway M dwarf candidates (RdMs) within 1 kpc of the Sun whose Galactocentric velocities exceed 400 km s$^{-1}$. The candidates were selected from the SDSS DR7 M Dwarf Catalog of West et al. (2011). Our RdMs have SDSS+USNO-B proper motions that are consistent with those recorded in the PPMXL, LSPM, and combined WISE+SDSS+2MASS catalogs. Sixteen RdMs are classified as dwarfs, while the remaining four RdMs are subdwarfs. We model the Galactic potential using a bulge-disk-halo profile (Kenyon et al. 2008; Brown et al. 2014). Our fastest RdM, with Galactocentric velocity 658.5 $\\pm$ 236.9 km s$^{-1}$, is a possible hypervelocity candidate, as it is unbound in 77% of our simulations. About half of our RdMs have kinematics that are consistent with ejection from the Galactic center. Seven of our RdMs have kinematics consistent with an ejection scenario from M31 or M32 to within 2{\\sigma}, although our distance-limited survey makes such a realization unlikely. No more than four of our RdMs ...

  6. Stellar Cluster Candidates Discovered in the Magellanic System

    Science.gov (United States)

    Piatti, Andrés E.

    2017-01-01

    We address the currently exciting issue of the presence of stellar clusters in the periphery of the Magellanic Clouds (MCs) and beyond by making use of a wealth of wide-field high-quality images released in advance from the Magellanic Stellar Hystory (SMASH) survey. We conducted a sound search for new stellar cluster candidates from suitable kernel density estimators running for appropriate ranges of radii and stellar densities. In addition, we used a functional relationship to account for the completeness of the SMASH field sample analyzed that takes into account not only the number of fields used but also their particular spatial distribution; the present sample statistically represents ∼50% of the whole SMASH survey. The relative small number of new stellar cluster candidates identified, most of them distributed in the outer regions of the MCs, might suggest that the lack of detection of a larger number of new cluster candidates beyond the main bodies of the MCs could likely be the outcome once the survey is completed.

  7. ALMA and VLA Observations of Proplyd Candidates near Sgr A*

    Science.gov (United States)

    Yusef-Zadeh, Farhad; Cotton, William D.; Royster, Marc; Kunneriath, Devaky; Wardle, M.; Roberts, D. A.; Wootten, Al; Schoedel, R.

    2017-01-01

    Using the VLA, we recently detected a large number of protoplanetary disk (proplyd) candidates lying within a couple of light years of the massive black hole Sgr A*. The bow-shock appearance of proplyd candidates point toward the young massive stars located near Sgr A*. Similar to Orion proplyds, the strong UV radiation from the cluster of massive stars at the Galactic center is expected to photoevaporate and photoionize the circumstellar disks around young, low mass stars, thus allowing detection of the ionized outflows. To confirm this interpretation, ALMA observations detect millimeter emission at 226 GHz from five proplyd candidates that had been detected at 44 and 34 GHz with the VLA. We determine the mass of protoplanetary disks from cool dust emission. These measurements show the presence of on-going star formation with the implication that gas clouds can survive near Sgr A* and the relative importance of high vs low-mass star formation in the strong tidal and radiation fields of the Galactic center.

  8. Identification of candidate genes for dyslexia susceptibility on chromosome 18.

    Directory of Open Access Journals (Sweden)

    Thomas S Scerri

    Full Text Available Six independent studies have identified linkage to chromosome 18 for developmental dyslexia or general reading ability. Until now, no candidate genes have been identified to explain this linkage. Here, we set out to identify the gene(s conferring susceptibility by a two stage strategy of linkage and association analysis.Linkage analysis: 264 UK families and 155 US families each containing at least one child diagnosed with dyslexia were genotyped with a dense set of microsatellite markers on chromosome 18. Association analysis: Using a discovery sample of 187 UK families, nearly 3000 SNPs were genotyped across the chromosome 18 dyslexia susceptibility candidate region. Following association analysis, the top ranking SNPs were then genotyped in the remaining samples. The linkage analysis revealed a broad signal that spans approximately 40 Mb from 18p11.2 to 18q12.2. Following the association analysis and subsequent replication attempts, we observed consistent association with the same SNPs in three genes; melanocortin 5 receptor (MC5R, dymeclin (DYM and neural precursor cell expressed, developmentally down-regulated 4-like (NEDD4L.Along with already published biological evidence, MC5R, DYM and NEDD4L make attractive candidates for dyslexia susceptibility genes. However, further replication and functional studies are still required.

  9. THE EVALUATION OF THE MOTIVATIONS OF TEACHER CANDIDATES

    Directory of Open Access Journals (Sweden)

    Zuhal ÇELİKTÜRK

    2013-06-01

    Full Text Available The aim in this study is to define the reading profiles of teacher candidates in terms of text/reading types and reading purposes. The study is designed as a screening type, qualitative research. 65 teacher candidates from Mehmet Akif Ersoy University are selected with random sampling to take place in the study. The data is collected by the interview method, which is a qualitative research method. An interview form named “Motivation to Read Profile”, that is adapted by researchers, is used as the tool for data collection. Data is analyzed by content analyzing. At the end of the study it’s determined that, 80% of the teacher candidates have high motivations to read; and they usually read to acquire information, get the help of their teachers ad friends to choose books, use internet a lot for finding reading materials, and they don’t usually carry books with themselves, yet they read at home and library. Also, the results show that the readings at home are usually news/newspapers on the internet, and the readings at library are more generally for research and homework; because of this, readings at library are more focused on books and magazines.

  10. Evaluation and selection of candidate high-level waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Bernadzikowski, T. A.; Allender, J. S.; Butler, J. L.; Gordon, D. E.; Gould, Jr., T. H.; Stone, J. A.

    1982-03-01

    Seven candidate waste forms being developed under the direction of the Department of Energy's National High-Level Waste (HLW) Technology Program, were evaluated as potential media for the immobilization and geologic disposal of high-level nuclear wastes. The evaluation combined preliminary waste form evaluations conducted at DOE defense waste-sites and independent laboratories, peer review assessments, a product performance evaluation, and a processability analysis. Based on the combined results of these four inputs, two of the seven forms, borosilicate glass and a titanate based ceramic, SYNROC, were selected as the reference and alternative forms for continued development and evaluation in the National HLW Program. Both the glass and ceramic forms are viable candidates for use at each of the DOE defense waste-sites; they are also potential candidates for immobilization of commercial reprocessing wastes. This report describes the waste form screening process, and discusses each of the four major inputs considered in the selection of the two forms.

  11. Discovery of Two Jovian Planet Candidates Around AU Mic

    Science.gov (United States)

    Plavchan, Peter; Gao, Peter; Gagne, Jonathan; Tanner, Angelle M.; Furlan, Elise; Brinkworth, Carolyn; von Braun, Kaspar; Ciardi, David R.; Kane, Stephen R.; White, Russel; Johnson, John A.; Hall, Ryan; Giddens, Frank; Zilberman, Perri; Huber, Joe; Nishimoto, America; Cancino, Andrew; Weigand, Denise; Klenke, Christopher

    2017-01-01

    We present a pair of candidate Jovian exoplanets discovered with the radial velocity (RV) technique in the near-infrared (NIR) orbiting the young M dwarf star AU Mic (a ~ 0.3 and 3.5 AU; M_p ~ 1.5 and 6 M_J). Data were obtained at 2.3 microns from 2010-2016 with the R=46,000 CSHELL spectrograph at the NASA Infrared Telescope Facility, and from 2005-2007 with the R=25,000 NIRSPEC spectrograph at the Keck Observatory. AU Mic possesses long-lived BY Draconis type polar starspots with a known rotation period of 4.865 days. No signal in the NIR RVs is identified that is consistent with the rotation period of the star, but stellar activity remains a possible explanation for the observed NIR RV variability. The outer Jovian planet candidate offers a plausible dynamical explanation for the observed debris disk dynamics of moving "clumps" on several year time-scales. It may be possible to directly image the outer planet candidate with the current generation of high contrast imaging instruments. If confirmed, this discovery would demonstrate the utility of RV precursor observations for informing direct imaging surveys and the utility of NIR RV searches for planets around young and/or active stars. These results also point to the promise of future NIR precise RVs, including iSHELL, SPIRou, HPF and CARMENES, which will operate at higher precision and with larger spectral grasp than CSHELL.

  12. Identification of new transitional disk candidates in Lupus with Herschel

    CERN Document Server

    Bustamante, I; Ribas, Á; Bouy, H; Prusti, T; Pilbratt, G L; André, Ph

    2015-01-01

    New data from the Herschel Space Observatory are broadening our understanding of the physics and evolution of the outer regions of protoplanetary disks in star forming regions. In particular they prove to be useful to identify transitional disk candidates. The goals of this work are to complement the detections of disks and the identification of transitional disk candidates in the Lupus clouds with data from the Herschel Gould Belt Survey. We extracted photometry at 70, 100, 160, 250, 350 and 500 $\\mu$m of all spectroscopically confirmed Class II members previously identified in the Lupus regions and analyzed their updated spectral energy distributions. We have detected 34 young disks in Lupus in at least one Herschel band, from an initial sample of 123 known members in the observed fields. Using the criteria defined in Ribas et al. (2013) we have identified five transitional disk candidates in the region. Three of them are new to the literature. Their PACS-70 $\\mu$m fluxes are systematically higher than thos...

  13. New Young Star Candidates in CG4 and Sa101

    CERN Document Server

    Rebull, L M; Hoette, V; Kim, J S; Laine, S; Foster, M; Laher, R; Legassie, M; Mallory, C R; McCarron, K; Sherry, W H

    2011-01-01

    The CG4 and Sa101 regions together cover a region of ~0.5 square degree in the vicinity of a "cometary globule" that is part of the Gum Nebula. There are seven previously identified young stars in this region; we have searched for new young stars using mid- and far-infrared data (3.6 to 70 microns) from the Spitzer Space Telescope, combined with ground-based optical data and near-infrared data from the Two-Micron All-Sky Survey (2MASS). We find infrared excesses in all 6 of the previously identified young stars in our maps, and we identify 16 more candidate young stars based on apparent infrared excesses. Most (73%) of the new young stars are Class II objects. There is a tighter grouping of young stars and young star candidates in the Sa101 region, in contrast to the CG4 region, where there are fewer young stars and young star candidates, and they are more dispersed. Few likely young objects are found in the "fingers" of the dust being disturbed by the ionization front from the heart of the Gum Nebula.

  14. The mass function of nearby black hole candidates

    CERN Document Server

    Caramete, Laurentiu I

    2009-01-01

    The mass function of super-massive black holes in our cosmic neighborhood is required to understand the statistics of activity, specifically the production of ultra high energy particles. We determine a mass function of black hole candidates from the entire sky outside the Galactic plane. Using the 2MASS catalogue as a starting point, and the well established correlation between black hole mass and the old bulge population of stars, we derive a list of nearby black hole candidates within the redshift range z 10^7 M_sol has 5,634 entries. Here we use this catalogue to derive the mass function. We correct for volume, so that this mass function is a volume limited distribution to redshift 0.025. The mass function of nearby black hole candidates is a straight simple power-law, extending down into the mass range, where nuclear star clusters may replace the super-massive black holes. The slope of this mass function can be explained in a simple merger picture. Integrating this mass function over the redshift range,...

  15. Evaluation of the Physics Teacher Candidates' Constructivist Teaching Activities

    Directory of Open Access Journals (Sweden)

    Ali Rıza AKDENİZ

    2010-06-01

    Full Text Available The aim of the study is to evaluate that physics teacher candidates improved constructivist activities according to 5E teaching Method in Special Teaching Methods-I courses. This study is carried out with 27 Physics teacher candidates who studied at KTU Fatih Education Faculty in spring term of 2007-2008 academic year. The findings from the study consist of 21 teaching activities which were created by the seven groups according to the defined criteria by the researchers. In conclusion, it was seen that physics teacher candidates can reflect some of 5E teaching method in the materials, and provide activities which include primary experiences for students can build their knowledge. However, it was determined some mistakes and defects about relations physics topics and real life, and explanation stage, extension stage, evaluation stage and crossing about this stages. Therefore it can be suggested that teacher candidates’ defects on the occupational education lessons both making up for and taking into account for new students and reflecting contemporary teaching approaches to the field education lessons.

  16. First microlensing candidate towards M31 from Nainital Microlensing Survey

    CERN Document Server

    Joshi, Y C; Narasimha, D; Sagar, R

    2004-01-01

    We report our first microlensing candidate NMS-E1 towards M31 from the data accumulated during four years long Nainital Microlensing Survey. Cousin R and I band observations of ~13'x13' field in the direction of M31 were carried out since 1998 and data is analysed using pixel technique proposed by the AGAPE collaboration. The NMS-E1 lies in the disk of M31 at \\alpha = 0:43:33.3 and \\delta = +41:06:44, about 15.5 arcmin away in the South-East direction from the center of M31. The degenerate Paczy\\'{n}ski fit gives a half intensity duration of ~ 59 days. The photometric analysis of candidate shows that it reached up to R ~ 20.1 mag at the time of maximum brightness and colour of the source star estimated to be (R-I)_0 ~ 1.1 mag. It is seen that the microlensing candidate is blended by red variable stars consequently light curves do not strictly follow the characteristic Paczy\\'{n}ski shape and achromatic nature however its long period monitoring and similar behaviour in R and I bands lend support of its microle...

  17. Candidate z~8-9 Galaxies from WFC3 Imaging

    CERN Document Server

    Lorenzoni, Silvio; Wilkins, Stephen; Stanway, Elizabeth; Jarvis, Matt; Caruana, Joseph

    2010-01-01

    We present a search for galaxies at 7.5candidates at redshift z~8-9 over an area of ~50 square arcminutes. Previous searches for Y-drops with WFC3 have focussed only on the Hubble Ultra Deep Field (HUDF), and our larger survey (involving two other nearby deep fields and a wider area survey) has trebelled the number of robust Y-drop candidates. For the first time, we have sufficient Z~8-9 galaxies to fit a both phi* and M* of the UV Schechter luminosity function. There is evidence for evolution in this luminosity function from z=6-7 to z=8-9, in the sense that there are fewer UV-bright galaxies at z~8-9, consistent with an evolution mainly in M*. The candidate z~8-9 galaxies we detect have insufficient ionizing flux to ...

  18. Candidate genes for idiopathic epilepsy in four dog breeds

    Directory of Open Access Journals (Sweden)

    Mickelson James R

    2011-04-01

    Full Text Available Abstract Background Idiopathic epilepsy (IE is a naturally occurring and significant seizure disorder affecting all dog breeds. Because dog breeds are genetically isolated populations, it is possible that IE is attributable to common founders and is genetically homogenous within breeds. In humans, a number of mutations, the majority of which are genes encoding ion channels, neurotransmitters, or their regulatory subunits, have been discovered to cause rare, specific types of IE. It was hypothesized that there are simple genetic bases for IE in some purebred dog breeds, specifically in Vizslas, English Springer Spaniels (ESS, Greater Swiss Mountain Dogs (GSMD, and Beagles, and that the gene(s responsible may, in some cases, be the same as those already discovered in humans. Results Candidate genes known to be involved in human epilepsy, along with selected additional genes in the same gene families that are involved in murine epilepsy or are expressed in neural tissue, were examined in populations of affected and unaffected dogs. Microsatellite markers in close proximity to each candidate gene were genotyped and subjected to two-point linkage in Vizslas, and association analysis in ESS, GSMD and Beagles. Conclusions Most of these candidate genes were not significantly associated with IE in these four dog breeds, while a few genes remained inconclusive. Other genes not included in this study may still be causing monogenic IE in these breeds or, like many cases of human IE, the disease in dogs may be likewise polygenic.

  19. Robo-AO Kepler Planetary Candidate Survey. II. Adaptive Optics Imaging of 969 Kepler Exoplanet Candidate Host Stars

    Science.gov (United States)

    Baranec, Christoph; Ziegler, Carl; Law, Nicholas M.; Morton, Tim; Riddle, Reed; Atkinson, Dani; Schonhut, Jessica; Crepp, Justin

    2016-07-01

    We initiated the Robo-AO Kepler Planetary Candidate Survey in 2012 to observe each Kepler exoplanet candidate host star with high angular resolution, visible light, laser adaptive optics (AOs) imaging. Our goal is to find nearby stars lying in Kepler's photometric apertures that are responsible for the relatively high probability of false-positive exoplanet detections and that cause underestimates of the size of transit radii. Our comprehensive survey will also shed light on the effects of stellar multiplicity on exoplanet properties and will identify rare exoplanetary architectures. In this second part of our ongoing survey, we observed an additional 969 Kepler planet candidate hosts and we report blended stellar companions up to {{Δ }}m≈ 6 that contribute to Kepler's measured light curves. We found 203 companions within ˜4″ of 181 of the Kepler stars, of which 141 are new discoveries. We measure the nearby star probability for this sample of Kepler planet candidate host stars to be 10.6% ± 1.1% at angular separations up to 2.″5, significantly higher than the 7.4% ± 1.0% probability discovered in our initial sample of 715 stars; we find the probability increases to 17.6% ± 1.5% out to a separation of 4.″0. The median position of Kepler Objects of Interest (KOIs) observed in this survey are 1.°1 closer to the galactic plane, which may account for some of the nearby star probability enhancement. We additionally detail 50 Keck AO images of Robo-AO observed KOIs in order to confirm 37 companions detected at a <5σ significance level and to obtain additional infrared photometry on higher significance detected companions.

  20. Radiologic diagnosis for AIDS patients complicated with candidal esophagitis

    Institute of Scientific and Technical Information of China (English)

    YANG Gen-dong; LU Pu-xuan; QIN Jing; LIU Shui-teng; ZHAN Neng-yong

    2011-01-01

    Background Candidal esophagitis is the primary infection among all digestive tract opportunistic ones in acquired immunodeficiency syndrome (AIDS) cases. X-ray manifestation reports of it are still rare. This study aimed to conduct a retrospective analysis on the X-ray data of 6 AIDS cases complicated with candidal esophagitis,and to study the X-ray characteristics of it combined with the findings from gastroscopy.Methods Among 6 cases in this series,all cases were confirmed by Shenzhen Center for Disease Control and Prevention (CDC) to be HIV positive and all of them had CD4 cell counts less than 150×106/L. All cases underwent X-ray and gastroscopy,and mycelium were found in the mucous membrane of the esophagus.Results In this series,the findings of the X-ray were as follows:(1) Affected areas:Four cases in the whole esophagus,2 cases in the middle and lower part of esophagus;(2) Abnormal motivity:Six cases had decreased tension,loose walls,weakened peristalsis,decreased number of peristalsis waves and delayed emptying of barium;(3) Abnormal contour:Six cases had the sign of "decorative border" or "brush",two cases had narrowed canal;(4) Abnormal membrane and "cobblestone sign":Six cases had thickened membrane and "cobblestone sign" on the surface of the abnormal membrane. The hyperemia of mucosa was covered tightly with yellow-white pseudomembrane spots. This was in accordance with the small cobblestone-like filling defect found by X-ray.Conclusions If the AIDS cases have dysphagia,and X-ray shows that more than two sections of the esophagus are affected,with decreased motility,the walls in the sign of "brush" or "decorative edges",thickened membrane with "cobblestone sign",candidal esophagitis is highly possible.

  1. Transiting planet candidates with ASTEP 400 at Dome C, Antarctica

    Science.gov (United States)

    Mékarnia, D.; Guillot, T.; Rivet, J.-P.; Schmider, F.-X.; Abe, L.; Gonçalves, I.; Agabi, A.; Crouzet, N.; Fruth, T.; Barbieri, M.; Bayliss, D. D. R.; Zhou, G.; Aristidi, E.; Szulagyi, J.; Daban, J.-B.; Fanteï-Caujolle, Y.; Gouvret, C.; Erikson, A.; Rauer, H.; Bouchy, F.; Gerakis, J.; Bouchez, G.

    2016-11-01

    ASTEP 400, the main instrument of the ASTEP (Antarctica Search for Transiting ExoPlanets) programme, is a 40 cm telescope, designed to withstand the harsh conditions in Antarctica, achieving a photometric accuracy of a fraction of millimagnitude on hourly time-scales for planet-hosting southern bright (R ˜ 12 mag) stars. We review the performances of this instrument, describe its operating conditions, and present results from the analysis of observations obtained during its first three years (2010-2012) of operation, before its repatriation in 2014. During this time, we observed a total of 22 stellar fields (1° × 1° field of view). Each field, in which we measured stars up to magnitude R = 18 mag, was observed continuously during ˜7 to ˜30 d. More than 200 000 frames were recorded and 310 000 stars processed, using an implementation of the optimal image subtraction photometry algorithm. We found 43 planetary transit candidates. 20 of these candidates were observed using spectroscopic follow-ups including four targets classified as good planet candidates. Our results demonstrate that accurate near-continuous photometric observations are achievable from the Concordia station at Dome C in Antarctica, even if we were not able to reach the nominal photometric precision of the instrument. We conducted a correlation analysis between the rms noise and a large number of external parameters and found that source of the ˜1 mmag correlated noise is not obvious and does not depend on a single parameter. However, our analysis provided some hints and guidance to increase the photometric accuracy of the instrument. These improvements should equip any future telescope operating in Antarctica.

  2. Event display of a H -> 4e candidate event

    CERN Multimedia

    ATLAS, Collaboration

    2012-01-01

    Event display of a H -> 4e candidate event with m(4l) = 124.5 (124.6) GeV without (with) Z mass constraint. The masses of the lepton pairs are 70.6 GeV and 44.7 GeV. The event was recorded by ATLAS on 18-May-2012, 20:28:11 CEST in run number 203602 as event number 82614360. Zoom into the tracking detector and the LAr calorimeter where its detailed structure is highlighted. The tracks and clusters of the two electron pairs are colored red and blue, respectively.

  3. Event display of a H -> 4e candidate event

    CERN Multimedia

    ATLAS, Collaboration

    2012-01-01

    Event display of a H -> 4e candidate event with m(4l) = 124.5 (124.6) GeV without (with) Z mass constraint. The masses of the lepton pairs are 70.6 GeV and 44.7 GeV. The event was recorded by ATLAS on 18-May-2012, 20:28:11 CEST in run number 203602 as event number 82614360. The tracks and clusters of the two electron pairs are colored red and blue, respectively.

  4. Event display of a H -> 4e candidate event

    CERN Multimedia

    ATLAS, Collaboration

    2012-01-01

    Event display of a H -> 4e candidate event with m(4l) = 124.5 (124.6) GeV without (with) Z mass constraint. The masses of the lepton pairs are 70.6 GeV and 44.7 GeV. The event was recorded by ATLAS on 18-May-2012, 20:28:11 CEST in run number 203602 as event number 82614360. Zoom into the tracking detector. The tracks and clusters of the two electron pairs are colored red and blue, respectively.

  5. Experience with CANDID: Comparison algorithm for navigating digital image databases

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.; Cannon, M.

    1994-10-01

    This paper presents results from the authors experience with CANDID (Comparison Algorithm for Navigating Digital Image Databases), which was designed to facilitate image retrieval by content using a query-by-example methodology. A global signature describing the texture, shape, or color content is first computed for every image stored in a database, and a normalized similarity measure between probability density functions of feature vectors is used to match signatures. This method can be used to retrieve images from a database that are similar to a user-provided example image. Results for three test applications are included.

  6. Elementary particles, dark matter candidate and new extended standard model

    Science.gov (United States)

    Hwang, Jaekwang

    2017-01-01

    Elementary particle decays and reactions are discussed in terms of the three-dimensional quantized space model beyond the standard model. Three generations of the leptons and quarks correspond to the lepton charges. Three heavy leptons and three heavy quarks are introduced. And the bastons (new particles) are proposed as the possible candidate of the dark matters. Dark matter force, weak force and strong force are explained consistently. Possible rest masses of the new particles are, tentatively, proposed for the experimental searches. For more details, see the conference paper at https://www.researchgate.net/publication/308723916.

  7. Environmental Systems Research Candidates FY-01 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David Lynn; Piet, Steven James

    2001-03-01

    The Environmental Systems Research Candidates (ESRC) Program ran from April 2000 through September 2001 as part of the Environmental Systems Research and Analysis (ESRA) Program at the Idaho National Engineering and Environmental Laboratory (INEEL). ESRA provides key science and technology to meet the cleanup mission of the U.S. Department of Energy Office of Environmental Management (EM), and performs research and development that will help solve current legacy problems and enhance the INEEL’s scientific and technical capability for solving longer-term challenges. This report documents the accomplishments of the ESRC Program. The ESRC Program consisted of 25 tasks subdivided within four research areas.

  8. Proper motions of Upper Sco T-type candidates

    CERN Document Server

    Lodieu, N; Dobbie, P D

    2013-01-01

    We present new z- and H-band photometry and proper motion measurements for the five candidate very-low-mass T-type objects we recently proposed to be members of the nearest OB association to the Sun, Upper Scorpius. These new data fail to corroborate our prior conclusions regarding their spectral types and affiliation with the Upper Scorpius population. We conclude that we may be in presence of a turnover in the mass function of Upper Sco taking place below 10-4 Jupiter masses, depending on the age assigned to Upper Sco and the models used.

  9. A double candidate survivable routing protocol for HAP network

    Science.gov (United States)

    He, Panfeng; Li, Chunyue; Ni, Shuyan

    2016-11-01

    To improve HAP network invulnerability, and at the same time considering the quasi-dynamic topology in HAP network, a simple and reliable routing protocol is proposed in the paper. The protocol firstly uses a double-candidate strategy for the next-node select to provide better robustness. Then during the maintenance stage, short hello packets instead of long routing packets are used only to check link connectivity in the quasi-dynamic HAP network. The route maintenance scheme based on short hello packets can greatly reduce link spending. Simulation results based on OPNET demonstrate the effectiveness of the proposed routing protocol.

  10. 29 CFR 1990.121 - Candidate list of potential occupational carcinogens.

    Science.gov (United States)

    2010-07-01

    ... Health Organization; (5) The Toxic Substances Control Act Inventory of Chemical Substances, published by... classification. The Secretary may tentatively designate substances on the Candidate List as candidates for... ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) IDENTIFICATION, CLASSIFICATION, AND REGULATION OF...

  11. Performance of women candidates on the American Board of Internal Medicine Certifying Examination, 1973-1982.

    Science.gov (United States)

    Norcini, J J; Fletcher, S W; Quimby, B B; Shea, J A

    1985-01-01

    Trends in the performances of female and male candidates taking the American Board of Internal Medicine Certifying Examination from 1973 through 1982 were examined. The mean scores of female candidates who graduated from medical schools in the United States or Canada and who were taking the examination for the first time improved from 428 to 470, and the percentage of those passing improved from 59% to 76%. The number of women taking the examination also increased markedly, by over 500%. Performance of female candidates remained slightly lower than that of male candidates, regardless of the quality of the residency training program or the medical school from which a candidate had graduated or the rating given a candidate by the director of the candidate's residency program. Except for the oldest candidates, age followed this pattern as well. Our findings suggest that the gender gap in scores on the Certifying Examination in Internal Medicine is narrowing.

  12. ADAM33, a new candidate for psoriasis susceptibility.

    Directory of Open Access Journals (Sweden)

    Fabienne Lesueur

    Full Text Available Psoriasis is a chronic skin disorder with multifactorial etiology. In a recent study, we reported results of a genome-wide scan on 46 French extended families presenting with plaque psoriasis. In addition to unambiguous linkage to the major susceptibility locus PSORS1 on Chromosome 6p21, we provided evidence for a susceptibility locus on Chromosome 20p13. To follow up this novel psoriasis susceptibility locus we used a family-based association test (FBAT for an association scan over the 17 Mb candidate region. A total of 85 uncorrelated SNP markers located in 65 genes of the region were initially investigated in the same set of large families used for the genome wide search, which consisted of 295 nuclear families. When positive association was obtained for a SNP, candidate genes nearby were explored more in detail using a denser set of SNPs. Thus, the gene ADAM33 was found to be significantly associated with psoriasis in this family set (The best association was on a 3-SNP haplotype P = 0.00004, based on 1,000,000 permutations. This association was independent of PSORS1. ADAM33 has been previously associated with asthma, which demonstrates that immune system diseases may be controlled by common susceptibility genes with general effects on dermal inflammation and immunity. The identification of ADAM33 as a psoriasis susceptibility gene identified by positional cloning in an outbred population should provide insights into the pathogenesis and natural history of this common disease.

  13. Self-gravitating disc candidates around massive young stars

    Science.gov (United States)

    Forgan, D. H.; Ilee, J. D.; Cyganowski, C. J.; Brogan, C. L.; Hunter, T. R.

    2016-11-01

    There have been several recent detections of candidate Keplerian discs around massive young protostars. Given the relatively large disc-to-star mass ratios in these systems, and their young ages, it is worth investigating their propensity to becoming self-gravitating. To this end, we compute self-consistent, semi-analytic models of putative self-gravitating discs for five candidate disc systems. Our aim is not to fit exactly the observations, but to demonstrate that the expected dust continuum emission from marginally unstable self-gravitating discs can be quite weak, due to high optical depth at the mid-plane even at millimetre wavelengths. In the best cases, the models produce `observable' disc masses within a factor of self-gravitating disc model compares well with observations. If these discs are self-gravitating, they satisfy the conditions for disc fragmentation in their outer regions. These systems may hence have as-yet-unresolved low-mass stellar companions, and are thus promising targets for future high angular resolution observations.

  14. Gaia FGK Benchmark Stars: New Candidates At Low-Metallicities

    CERN Document Server

    Hawkins, Keith; Heiter, Ulrike; Soubiran, Caroline; Blanco-Cuaresma, Sergi; Casagrande, Luca; Gilmore, Gerry; Lind, Karin; Magrini, Laura; Masseron, Thomas; Pancino, Elena; Randich, Sofia; Worley, Clare C

    2016-01-01

    We have entered an era of large spectroscopic surveys in which we can measure, through automated pipelines, the atmospheric parameters and chemical abundances for large numbers of stars. Calibrating these survey pipelines using a set of "benchmark stars" in order to evaluate the accuracy and precision of the provided parameters and abundances is of utmost importance. The recent proposed set of Gaia FGK benchmark stars of Heiter et al. (2015) has no recommended stars within the critical metallicity range of $-2.0 <$ [Fe/H] $< -1.0$ dex. In this paper, we aim to add candidate Gaia benchmark stars inside of this metal-poor gap. We began with a sample of 21 metal-poor stars which was reduced to 10 stars by requiring accurate photometry and parallaxes, and high-resolution archival spectra. The procedure used to determine the stellar parameters was similar to Heiter et al. (2015) and Jofre et al. (2014) for consistency. The effective temperature (T$_{\\mathrm{eff}}$) of all candidate stars was determined using...

  15. SEMG1 may be the candidate gene for idiopathic asthenozoospermia.

    Science.gov (United States)

    Yu, Q; Zhou, Q; Wei, Q; Li, J; Feng, C; Mao, X

    2014-03-01

    Asthenozoospermia (AZS) is a major cause of male infertility, aetiology of which is reported to be related with gene mutation or deletion. However, studies on candidate genes for AZS are very scarce. In this study, we examined the gene expression profiles of asthenozoosperm. Gene expression profile analyses with microarray on spermatozoa specimens from 12 asthenozoosperm patients and 12 age-matched volunteers were performed; data analysis was performed with bioinformatics tools. Data analysis revealed that 1265 and 262 genes were significantly (P < 0.05) and differently expressed (≥2-fold) between groups performed with GeneSpring and BRB-ArrayTools respectively. Of these differently expressed genes, 71 were identified as molecular signatures of asthenozoosperm, of which most involved in primary metabolic process and cellular metabolic process. Molecular signatures were filtered performed with NextBio, 21 genes were identified to be specially expressed in asthenozoosperm. We used Finding Associated Concepts with Text Analysis to match the specially expressed genes against the MEDLINE database and found SEMG1 and PGAP1 were related to male fertility. Validation of the microarray data of SEMG1 was carried out using real-time PCR. Our study demonstrated that SEMG1 was significantly changed in asthenozoosperm, which could be the candidate gene for the development of diagnostic marker and provided the opportunity to further illustrate the biological mechanisms of asthenozoosperm.

  16. CANDIDATE GENE ANALYSIS IN ISRAELI SOLDIERS WITH STRESS FRACTURES

    Directory of Open Access Journals (Sweden)

    Ran Yanovich

    2012-03-01

    Full Text Available To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures. Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4 showed statistically significant differences (p < 0.05 in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR. Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations

  17. A spectroscopic study of field BHB star candidates

    CERN Document Server

    Kinman, T D; Cacciari, C; Bragaglia, A; Harmer, D; Valdes, F G

    2000-01-01

    New spectroscopic observations (R=15000 and 40000) are given for 31 nearby (V < 11) BHB star candidates. IUE low-resolution spectra are available for most of them. New determinations of temperature, gravity, reddening and abundances were obtained from these data using models computed by Castelli with an updated version of the ATLAS9 code. A summary of the visual photometry for these stars (including new photometry obtained at Kitt Peak) is also given. All 31 candidates are halo stars. We classify 28 as BHB stars because: (1) They lie close to the ZAHB (in a similar position to globular cluster BHB stars) in the Teff vs. log g plot. (2) Their distribution of vsini (less than 40 km/s) is similar to that found for the BHB stars in globular clusters. (3) Their [Fe/H] lies between -0.99 and -2.95 (mean [Fe/H] -1.67, dispersion 0.42 dex) which is similar to that found for field halo RR Lyrae and red HB stars but more metal- poor than for halo globular clusters. Field BHB stars with Teff greater than 8500 K show ...

  18. A Candidate Dual AGN at z=1.175

    CERN Document Server

    Barrows, R Scott; Madsen, Kristin; Harrison, Fiona; Assef, Roberto J; Comerford, Julia M; Cushing, Michael C; Fassnacht, Christopher D; Gonzalez, Anthony; Griffith, Roger; Hickox, Ryan; Kirkpatrick, J Davy; Lagattuta, David J

    2011-01-01

    The X-ray source CXOXBJ142607.6+353351 (CXOJ1426+35), which was identified in a 172 ks Chandra image in the Bootes field, shows double-peaked rest-frame optical/UV emission lines, separated by 0.69" (5.5 kpc) in the spatial dimension and by 690 km s^-1 in the velocity dimension. The high excitation lines and emission line ratios indicate both systems are ionized by an AGN continuum, and the double-peaked profile resembles that of candidate dual AGN. At a redshift of z=1.175, this source is the highest redshift candidate dual AGN yet identified. However, many sources have similar emission line profiles for which other interpretations are favored. We have analyzed the substantial archival data available in this field, as well as acquired near-infrared (NIR) adaptive optics (AO) imaging and NIR slit spectroscopy. The X-ray spectrum is hard, implying a column density of several 10^23 cm^-2. Though heavily obscured, the source is also one of the brightest in the field, with an absorption-corrected 2-10 keV luminos...

  19. A computer vision based candidate for functional balance test.

    Science.gov (United States)

    Nalci, Alican; Khodamoradi, Alireza; Balkan, Ozgur; Nahab, Fatta; Garudadri, Harinath

    2015-08-01

    Balance in humans is a motor skill based on complex multimodal sensing, processing and control. Ability to maintain balance in activities of daily living (ADL) is compromised due to aging, diseases, injuries and environmental factors. Center for Disease Control and Prevention (CDC) estimate of the costs of falls among older adults was $34 billion in 2013 and is expected to reach $54.9 billion in 2020. In this paper, we present a brief review of balance impairments followed by subjective and objective tools currently used in clinical settings for human balance assessment. We propose a novel computer vision (CV) based approach as a candidate for functional balance test. The test will take less than a minute to administer and expected to be objective, repeatable and highly discriminative in quantifying ability to maintain posture and balance. We present an informal study with preliminary data from 10 healthy volunteers, and compare performance with a balance assessment system called BTrackS Balance Assessment Board. Our results show high degree of correlation with BTrackS. The proposed system promises to be a good candidate for objective functional balance tests and warrants further investigations to assess validity in clinical settings, including acute care, long term care and assisted living care facilities. Our long term goals include non-intrusive approaches to assess balance competence during ADL in independent living environments.

  20. Sleeping Beauty Mouse Models Identify Candidate Genes Involved in Gliomagenesis

    Science.gov (United States)

    Vyazunova, Irina; Maklakova, Vilena I.; Berman, Samuel; De, Ishani; Steffen, Megan D.; Hong, Won; Lincoln, Hayley; Morrissy, A. Sorana; Taylor, Michael D.; Akagi, Keiko; Brennan, Cameron W.; Rodriguez, Fausto J.; Collier, Lara S.

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma. PMID:25423036

  1. Candidíase em pacientes aidéticos

    Directory of Open Access Journals (Sweden)

    C.E.O.P. Campos

    1992-09-01

    Full Text Available Trinta e cinco aidéticos entre 19 e 55 anos admitidos e tratados de candidíase no Hospital Emílio Ribas, SP, com ELISA positivo para HIV e confirmado pelo Western Blot. Tuberculose em 9 sendo 2 com pericardite; neurotoxoplasmose em 6; neurocriptococose em 5; herpes labial em 4; pneumocistose em 3 e sarcoma de Kaposi em 2, achavam-se associadas. A concentração inibitória mínima 50% (MIC 50% para os azoles foi: ketoconazol= 2,2 µg/ml; itraconazol- 21,0 µg/ml; fluconazol = 19,0 µg/ml. O MIC 50% para ospolienos: nistatina- 50,0 µg/ml; anfotericina B= 0,12 µg/ml e para 5 fluorcitosina= 1,6 µg/ml nas 35 amostras de Candida isoladas. Testes não paramétricos de Siegel revelaram significante identificação (80% das Candida albicans na candidíase, e que a dose de AMB não modificou o número de óbitos, precoce e tardio, ocorridos nesses aidéticos. O uso prévio dos azoles e da nistatina explicaria, talvez, o elevado MIC 50% observado nas amostras de Candida isoladas.

  2. Candidate plasma-facing materials for EUV lithography source components

    Science.gov (United States)

    Hassanein, Ahmed; Burtseva, Tatiana; Brooks, Jeff N.; Konkashbaev, Isak K.; Rice, Bryan J.

    2003-06-01

    Material selection and lifetime issues for extreme ultraviolet (EUV) lithography are of critical importance to the success of this technology for commercial applications. This paper reviews current trends in production and use of plasma-facing electrodes, insulators, and wall materials for EUV type sources. Ideal candidate materials should be able to: withstand high thermal shock from the short pulsed plasma; withstand high thermal loads without structural failure; reduce debris generation during discharge; and be machined accurately. We reviewed the literature on current and proposed fusion plasma-facing materials as well as current experience with plasma gun and other simulation devices. Both fusion and EUV source materials involve issues of surface erosion by particle sputtering and heat-induced evaporation/melting. These materials are either bare structural materials or surface coatings. EUV materials can be divided into four categories: wall, electrode, optical, and insulator materials. For electric discharge sources, all four types are required, whereas laser-produced plasma EUV sources do not require electrode and insulator materials. Several types of candidate alloy and other materials and methods of manufacture are recommended for each component of EUV lithography light sources.

  3. Novel approaches to identify protective malaria vaccine candidates

    Directory of Open Access Journals (Sweden)

    Wan Ni eChia

    2014-11-01

    Full Text Available Efforts to develop vaccines against malaria have been the focus of substantial research activities for decades. Several categories of candidate vaccines are currently being developed for protection against malaria, based on antigens corresponding to the pre-erythrocytic, blood-stage or sexual stages of the parasite. Long lasting sterile protection from Plasmodium falciparum sporozoite challenge has been observed in human following vaccination with whole parasite formulations, clearly demonstrating that a protective immune response targeting predominantly the pre-erythrocytic stages can develop against malaria. However, most of vaccine candidates currently being investigated, which are mostly subunits vaccines, have not been able to induce substantial (>50% protection thus far. This is due to the fact that the antigens responsible for protection against the different parasite stages are still yet to be known and relevant correlates of protection have remained elusive. For a vaccine to be developed in a timely manner, novel approaches are required. In this article, we review the novel approaches that have been developed to identify the antigens for the development of an effective malaria vaccine.

  4. Engineering of glucosinolate biosynthesis: candidate gene identification and validation.

    Science.gov (United States)

    Møldrup, Morten E; Salomonsen, Bo; Halkier, Barbara A

    2012-01-01

    The diverse biological roles of glucosinolates as plant defense metabolites and anticancer compounds have spurred a strong interest in their biosynthetic pathways. Since the completion of the Arabidopsis genome, functional genomics approaches have enabled significant progress on the elucidation of glucosinolate biosynthesis, although in planta validation of candidate gene function often is hampered by time-consuming generation of knockout and overexpression lines in Arabidopsis. To better exploit the increasing amount of data available from genomic sequencing, microarray database and RNAseq, time-efficient methods for identification and validation of candidate genes are needed. This chapter covers the methodology we are using for gene discovery in glucosinolate engineering, namely, guilt-by-association-based in silico methods and fast proof-of-function screens by transient expression in Nicotiana benthamiana. Moreover, the lessons learned in the rapid, transient tobacco system are readily translated to our robust, versatile yeast expression platform, where additional genes critical for large-scale microbial production of glucosinolates can be identified. We anticipate that the methodology presented here will be beneficial to elucidate and engineer other plant biosynthetic pathways.

  5. Non-Vestoid candidates in the inner Main Belt

    Science.gov (United States)

    Moskovitz, Nicholas; Oszkiewicz, Dagmara; Skiff, Brian; Kankiewicz, Pawel; Licandro, Javier; Galiazzo, Mattia; Zeilinger, Werner

    2016-10-01

    Most Howardite-Eucrite-Diogenite (HED) meteorites (analogues to V-type asteroids) are thought to originate from asteroid (4) Vesta. However some HEDs show distinct oxygen isotope ratios and therefore are thought to originate from other asteroids. In this study we try to identify asteroids that may represent parent bodies of those mismatching HEDs. In particular the origin of the anomalous Bunburra Rockhole meteorite was traced back to the inner main asteroid belt, showing that there might be asteroids that are not genetically linked to the asteroid (4) Vesta (the main source of V-type asteroids and HED meteorites) in the inner main belt. In this work we identify V-type asteroids outside the dynamical Vesta family whose rotational properties (retrograde vs prograde rotation) suggest the direction of Yarkovsky drift that sets them apart from typical Vestoids and Vesta fugitives. Specificly Nesvorny et al. 2008 simulated escapes paths from the Vesta family and showed that typical Vesta fugitives in the inner main asteroid belt at semi-major axis a drift or showing Yarkovsky drift direction towards (4) Vesta are the best candidates for non-Vestoidal V-type asteroids and therefore parent bodies of anomalous HED. In this study we have performed accurate photometric observations and determined sense of rotation for several asteroids testing their links to Vesta and anomalous HED. We have found several potential non-Vestoid candidates. Those objects have to be studied in more detail to fully confirm their link to anomalous HEDs.

  6. Trinocular stereo vision method based on mesh candidates

    Science.gov (United States)

    Liu, Bin; Xu, Gang; Li, Haibin

    2010-10-01

    One of the most interesting goals of machine vision is 3D structure recovery of the scenes. This recovery has many applications, such as object recognition, reverse engineering, automatic cartography, autonomous robot navigation, etc. To meet the demand of measuring the complex prototypes in reverse engineering, a trinocular stereo vision method based on mesh candidates was proposed. After calibration of the cameras, the joint field of view can be defined in the world coordinate system. Mesh grid is established along the coordinate axes, and the mesh nodes are considered as potential depth data of the object surface. By similarity measure of the correspondence pairs which are projected from a certain group of candidates, the depth data can be obtained readily. With mesh nodes optimization, the interval between the neighboring nodes in depth direction could be designed reasonably. The potential ambiguity can be eliminated efficiently in correspondence matching with the constraint of a third camera. The cameras can be treated as two independent pairs, left-right and left-centre. Due to multiple peaks of the correlation values, the binocular method may not satisfy the accuracy of the measurement. Another image pair is involved if the confidence coefficient is less than the preset threshold. The depth is determined by the highest sum of correlation of both camera pairs. The measurement system was simulated using 3DS MAX and Matlab software for reconstructing the surface of the object. The experimental result proved that the trinocular vision system has good performance in depth measurement.

  7. Sociological profiles of the candidate Turkish primary school teachers

    Directory of Open Access Journals (Sweden)

    D. Ali Arslan

    2007-10-01

    Full Text Available Teachers define the tomorrow’s of the society. In order to know and predict about future of the society, It has to be known the sociological profiles of the educators. In other words, it should be helpful to plan the education and to define the socio-political decisions on issue, if the social and psychological characteristics of the todays’ teachers were known before. Therefore, It was aimed to examine and analyse the sociological and social-psychological backgrounds of the candidate teachers. What a kind of social profile do they have? What are their opinion on particular actual social and political issues of the society. Do they present a homogeneus group character? Do they have enough skill and knowledge to educate tomorrow’s Turkish individuals? What are their major problems as the primary school teachers and teacher candidates? The answers of the theese kind of questions were examined within the research.A compherensive field reserarch realised to achieve the aim. A questionnaire form was developed and used for the interviews. There were structured, semi structured and open-ended questions in the questionnaire. A data sets was created from the data that were gathered from the field. The computer program of the SPSS (Statistical Packages for Social Sciences was used for analysing the data sets.

  8. No Evidence for Association between Amelogenesis Imperfecta and Candidate Genes

    Directory of Open Access Journals (Sweden)

    M Ghandehari Motlagh

    2009-03-01

    Full Text Available "nBackground: Amelogenesis imperfecta (AI is an inherited tooth disorder. Despite the fact that up to now, several gene muta­tions in MMP20, ENAM, AMELX and KLK4 genes have been reported to be associated with AI, many other genes sug­gested to be involved. The main objective of this study was to find the mutations in three major candidate genes including MMP20, ENAM and KLK4 responsible for AI from three Iranian families with generalized hypoplastic phenotype in all teeth. "nMethods: All exon/intron boundaries of subjected genes were amplified by polymerase chain reaction and subjected to direct sequencing."nResults: One polymorphisms was identified in KLK4 exon 2, in one family a homozygous mutation was found in the third base of codon 22 for serine (TCG>TCT, but not in other families. Although these base substitutions have been occurred in the signaling domain, they do not seem to influence the activity of KLK4 protein."nConclusion: Our results might support the further evidence for genetic heterogeneity; at least, in some AI cases are not caused by a gene in these reported candidate genes.

  9. Prevalence of substance-related disorders in heart transplantation candidates.

    Science.gov (United States)

    Sirri, L; Potena, L; Masetti, M; Tossani, E; Grigioni, F; Magelli, C; Branzi, A; Grandi, S

    2007-01-01

    Substance abuse cessation is one of the leading factors in determining the eligibility for the heart transplantation waiting list, as noncompliance with this issue may seriously endanger posttransplantation outcomes. Yet, the prevalence of substance-related disorders among candidates for heart transplantation has not been evaluated enough. Eighty three heart transplantation candidates were assessed for prior or current substance-related disorders through the Structured Clinical Interview for mental disorders according to DSM-IV. A prior history of at least one substance-related disorder was found in 64% of patients, with nicotine dependence as the most prevalent diagnosis (61.4% of the sample). Ten subjects were currently smokers, despite heart failure. A prior history of alcohol abuse and caffeine intoxication was found in 9.6% and 2.4% of patients, respectively. Substance abuse or dependence behaviors should be monitored during all the phases of heart transplantation program. Early identification of current substance-related disorders may allow better allocation of organ resources and proper lifestyle modification programs provision. A prior history of substance-related disorders should alert physicians to assess patients for possible relapse, especially after transplantation. The inclusion of a specialist in the assessment and treatment of substance-related disorders in the heart transplantation unit may reduce the risk of unsuccessful outcomes due to noncompliance with an adequate lifestyle.

  10. First catalog of strong lens candidates in the COSMOS field

    CERN Document Server

    Faure, Cecile; Covone, Giovanni; Tasca, Lidia; Leauthaud, Alexie; Capak, Peter; Jahnke, Knud; Smolcic, Vernesa; de la Torre, Sylvain; Ellis, Richard; Finoguenov, Alexis; Heymans, Catherine; Koekemoer, Anton; Le Fevre, Olivier; Massey, Richard; Mellier, Yannick; Refregier, Alexandre; Rhodes, Jason; Scoville, Nick; Schinnerer, Eva; Taylor, James; Van Waerbeke, Ludovic; Walcher, Jakob

    2008-01-01

    We present the first catalog of 67 strong galaxy-galaxy lens candidates discovered in the 1.64 square degree Hubble Space Telescope COSMOS survey. Twenty of these systems display multiple images or strongly curved large arcs. Our initial search is performed by visual inspection of the data and is restricted, for practical considerations, to massive early-type lens galaxies with arcs found at radii smaller than ~5''. Simple mass models are constructed for the best lens candidates and our results are compared to the strong lensing catalogs of the SLACS survey and the CASTLES database. These new strong galaxy-galaxy lensing systems constitute a valuable sample to study the mass distribution of early-type galaxies and their associated dark matter halos. We further expect this sample to play an important role in the testing of software algorithms designed to automatically search for strong gravitational lenses. From our analysis a robust lower limit is derived for the expected occurrence of strong galaxy-galaxy sy...

  11. Speeding disease gene discovery by sequence based candidate prioritization

    Directory of Open Access Journals (Sweden)

    Porteous David J

    2005-03-01

    Full Text Available Abstract Background Regions of interest identified through genetic linkage studies regularly exceed 30 centimorgans in size and can contain hundreds of genes. Traditionally this number is reduced by matching functional annotation to knowledge of the disease or phenotype in question. However, here we show that disease genes share patterns of sequence-based features that can provide a good basis for automatic prioritization of candidates by machine learning. Results We examined a variety of sequence-based features and found that for many of them there are significant differences between the sets of genes known to be involved in human hereditary disease and those not known to be involved in disease. We have created an automatic classifier called PROSPECTR based on those features using the alternating decision tree algorithm which ranks genes in the order of likelihood of involvement in disease. On average, PROSPECTR enriches lists for disease genes two-fold 77% of the time, five-fold 37% of the time and twenty-fold 11% of the time. Conclusion PROSPECTR is a simple and effective way to identify genes involved in Mendelian and oligogenic disorders. It performs markedly better than the single existing sequence-based classifier on novel data. PROSPECTR could save investigators looking at large regions of interest time and effort by prioritizing positional candidate genes for mutation detection and case-control association studies.

  12. Transiting extrasolar planetary candidates in the Galactic bulge

    CERN Document Server

    Sahu, K C; Bond, H E; Valenti, J; Smith, T E; Minniti, D; Zoccali, M; Livio, M; Panagia, N; Piskunov, N; Brown, T M; Brown, T; Renzini, A; Rich, R M; Clarkson, W; Lubow, S; Sahu, Kailash C.; Casertano, Stefano; Bond, Howard E.; Valenti, Jeff; Minniti, Dante; Zoccali, Manuela; Livio, Mario; Panagia, Nino; Piskunov, Nikolai; Brown, Thomas M.; Brown, Timothy; Renzini, Alvio; Clarkson, Will; Lubow, Stephen

    2006-01-01

    More than 200 extrasolar planets have been discovered around relatively nearby stars, primarily through the Doppler line shifts owing to the reflex motions of their host stars, and more recently through transits of some planets across the face of the host stars. The detection of planets with the shortest known periods, 1.2 to 2.5 days, has mainly resulted from transit surveys which have generally targeted stars more massive than 0.75 M_sun. Here we report the results from a planetary transit search performed in a rich stellar field towards the Galactic bulge. We discovered 16 candidates with orbital periods between 0.4 and 4.2 days, five of which orbit stars of 0.44 to 0.75 M_sun. In two cases, radial-velocity measurements support the planetary nature of the companions. Five candidates have orbital periods below 1.0 day, constituting a new class of ultra-short-period planets (USPPs), which occur only around stars of less than 0.88 M_sun. This indicates that those orbiting very close to more luminous stars mig...

  13. Reliability of MRI findings in candidates for lumbar disc prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Linda; Espeland, Ansgar [Haukeland University Hospital, Department of Radiology, Bergen (Norway); University of Bergen, Section for Radiology, Department of Surgical Sciences, Bergen (Norway); Neckelmann, Gesche [Haukeland University Hospital, Department of Radiology, Bergen (Norway); Gjertsen, Oeivind [Oslo University Hospital, Department of Neuroradiology, Oslo (Norway); Hellum, Christian [Oslo University Hospital, Department of Orthopaedics, Oslo (Norway); University of Oslo, Department of Orthopaedics, Oslo (Norway); Johnsen, Lars G. [University Hospital of Trondheim, National Centre for Diseases of the Spine, Trondheim (Norway); University Hospital of Trondheim, Orthopaedic Department, Trondheim (Norway); Eide, Geir E. [Haukeland University Hospital, Centre for Clinical Research, Bergen (Norway); University of Bergen, Department of Public Health and Primary Health Care, Bergen (Norway)

    2012-07-15

    Limited reliability data exist for localised magnetic resonance imaging (MRI) findings relevant to planning of treatment with lumbar disc prosthesis and later outcomes. We assessed the reliability of such findings in chronic low back pain patients who were accepted candidates for disc prosthesis. On pretreatment MRI of 170 patients (mean age 41 years; 88 women), three experienced radiologists independently rated Modic changes, disc findings and facet arthropathy at L3/L4, L4/L5 and L5/S1. Two radiologists rerated 126 examinations. For each MRI finding at each disc level, agreement was analysed using the kappa statistic and differences in prevalence across observers using a fixed effects model. All findings at L3/L4 and facet arthropathy at L5/S1 had a mean prevalence <10% across observers and were not further analysed, ensuring interpretable kappa values. Overall interobserver agreement was generally moderate or good (kappa 0.40-0.77) at L4-S1 for Modic changes, nucleus pulposus signal, disc height (subjective and measured), posterior high-intensity zone (HIZ) and disc contour, and fair (kappa 0.24) at L4/L5 for facet arthropathy. Posterior HIZ at L5/S1 and severely reduced subjective disc height at L4/L5 differed up to threefold in prevalence between observers (p < 0.0001). Intraobserver agreement was mostly good or very good (kappa 0.60-1.00). In candidates for disc prosthesis, mostly moderate interobserver agreement is expected for localised MRI findings. (orig.)

  14. Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications

    Directory of Open Access Journals (Sweden)

    S. Komossa

    2012-01-01

    Full Text Available Supermassive black holes (SMBHs may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves. Long-lived oscillations of the SMBHs in galaxy cores, and in rare cases even SMBH ejections from their host galaxies, are the consequence. Observationally, accreting recoiling SMBHs would appear as quasars spatially and/or kinematically offset from their host galaxies. The presence of the “kicks” has a wide range of astrophysical implications which only now are beginning to be explored, including consequences for black hole and galaxy assembly at the epoch of structure formation, black hole feeding, and unified models of active galactic nuclei (AGN. Here, we review the observational signatures of recoiling SMBHs and the properties of the first candidates which have emerged, including follow-up studies of the candidate recoiling SMBH of SDSSJ092712.65+294344.0.

  15. Self-gravitating disc candidates around massive young stars

    CERN Document Server

    Forgan, D H; Cyganowski, C J; Brogan, C L; Hunter, T R

    2016-01-01

    There have been several recent detections of candidate Keplerian discs around massive young protostars. Given the relatively large disc-to-star mass ratios in these systems, and their young ages, it is worth investigating their propensity to becoming self-gravitating. To this end, we compute self-consistent, semi-analytic models of putative self-gravitating discs for five candidate disc systems. Our aim is not to fit exactly the observations, but to demonstrate that the expected dust continuum emission from marginally unstable self-gravitating discs can be quite weak, due to high optical depth at the midplane even at millimetre wavelengths. In the best cases, the models produce "observable" disc masses within a factor of <1.5 of those observed, with midplane dust temperatures comparable to measured temperatures from molecular line emission. We find in two cases that a self-gravitating disc model compares well with observations. If these discs are self-gravitating, they satisfy the conditions for disc fragm...

  16. A Bioinformatics Filtering Strategy for Identifying Radiation Response Biomarker Candidates

    Science.gov (United States)

    Oh, Jung Hun; Wong, Harry P.; Wang, Xiaowei; Deasy, Joseph O.

    2012-01-01

    The number of biomarker candidates is often much larger than the number of clinical patient data points available, which motivates the use of a rational candidate variable filtering methodology. The goal of this paper is to apply such a bioinformatics filtering process to isolate a modest number (<10) of key interacting genes and their associated single nucleotide polymorphisms involved in radiation response, and to ultimately serve as a basis for using clinical datasets to identify new biomarkers. In step 1, we surveyed the literature on genetic and protein correlates to radiation response, in vivo or in vitro, across cellular, animal, and human studies. In step 2, we analyzed two publicly available microarray datasets and identified genes in which mRNA expression changed in response to radiation. Combining results from Step 1 and Step 2, we identified 20 genes that were common to all three sources. As a final step, a curated database of protein interactions was used to generate the most statistically reliable protein interaction network among any subset of the 20 genes resulting from Steps 1 and 2, resulting in identification of a small, tightly interacting network with 7 out of 20 input genes. We further ranked the genes in terms of likely importance, based on their location within the network using a graph-based scoring function. The resulting core interacting network provides an attractive set of genes likely to be important to radiation response. PMID:22768051

  17. A bioinformatics filtering strategy for identifying radiation response biomarker candidates.

    Directory of Open Access Journals (Sweden)

    Jung Hun Oh

    Full Text Available The number of biomarker candidates is often much larger than the number of clinical patient data points available, which motivates the use of a rational candidate variable filtering methodology. The goal of this paper is to apply such a bioinformatics filtering process to isolate a modest number (<10 of key interacting genes and their associated single nucleotide polymorphisms involved in radiation response, and to ultimately serve as a basis for using clinical datasets to identify new biomarkers. In step 1, we surveyed the literature on genetic and protein correlates to radiation response, in vivo or in vitro, across cellular, animal, and human studies. In step 2, we analyzed two publicly available microarray datasets and identified genes in which mRNA expression changed in response to radiation. Combining results from Step 1 and Step 2, we identified 20 genes that were common to all three sources. As a final step, a curated database of protein interactions was used to generate the most statistically reliable protein interaction network among any subset of the 20 genes resulting from Steps 1 and 2, resulting in identification of a small, tightly interacting network with 7 out of 20 input genes. We further ranked the genes in terms of likely importance, based on their location within the network using a graph-based scoring function. The resulting core interacting network provides an attractive set of genes likely to be important to radiation response.

  18. The Effect of Designed Geometry Teaching Lesson to the Candidate Teachers' Van Hiele Geometric Thinking Level

    Science.gov (United States)

    Yilmaz, Gül Kaleli; Koparan, Timur

    2016-01-01

    The aim of this study is to find out how designed Geometry Teaching Lesson affects candidate teachers' Van Hiele Geometric Thinking Levels. For that purpose, 14 weeks long study was performed with 44 candidate teachers who were university students in Turkey. Van Hiele Geometric Thinking Test was applied to candidate teachers before and after…

  19. An Analysis of the Candidate Teachers' Beliefs Related to Knowledge, Learning and Teaching

    Science.gov (United States)

    Bay, Erdal; Vural, Ömer Faruk; Demir, Servet; Bagceci, Birsen

    2015-01-01

    Candidate teachers have several beliefs related to their knowledge, learning and teaching. The purpose of this study is to analyze the beliefs of candidate teachers about knowledge, learning and teaching. Candidate teachers were assigned a scale and from the answers "belief points" were obtained based on their attitudes about these three…

  20. A fair trial? Assessment of liver transplant candidates with psychiatric illnesses.

    Science.gov (United States)

    Cherkassky, Lisa

    2011-12-01

    Allocating scarce organs to transplant candidates is only one stage in the long process of organ transplantation. Before being listed, all candidates must undergo a rigorous assessment by a multidisciplinary transplant team. The Department of Health and NHS Blood and Transplant (NHSBT) are responsible for the development of detailed strategies to ensure a fair and objective assessment experience for all transplant candidates. Difficulties arise when particularly vulnerable candidates, such as candidates with psychiatric illnesses, are assessed. NHSBT has already developed unique assessment guidelines for alcoholic and substance-abusing liver transplant candidates to allow for a more comprehensive evaluation, but candidates with psychiatric illnesses are still assessed against general criteria. Should these candidates be assessed against their own criteria? On what clinical grounds do transplant teams justify excluding such candidates from transplantation? Is redress available for candidates who feel they have been unfairly refused a liver transplant simply because of their psychiatric illness? This essay will critically examine the provisions published by the Department of Health and NHSBT for the assessment of liver transplant candidates with psychiatric illnesses, and will provide a commentary as to whether enough is being done to protect these particularly vulnerable candidates from inconsistent assessment decisions.

  1. Performance Assessment for California Teachers and English-Language Arts Candidates in a Rural Border Community

    Science.gov (United States)

    Ajayi, Lasisi

    2014-01-01

    This study explores the appropriateness of the Performance Assessment for California Teachers (PACT) as an instrument of assessing English-language arts (ELA) teacher candidates' effectiveness in a rural border community. Eight -candidates participated in the study. The findings call into question the adequacy of PACT to assess the candidates'…

  2. Preparing Teacher Candidates for Virtual Field Placements via an Exposure to K-12 Online Teaching

    Science.gov (United States)

    Luo, Tian; Hibbard, Laura; Franklin, Teresa; Moore, David Richard

    2017-01-01

    Aim/Purpose: The goal of this project was to determine what effects exposure to online K-12 teaching and learning activities had on teacher candidates' perceptions of K-12 online learning, how the exposure allowed teacher candidates to reach greater understanding of online pedagogy, and what effect such exposure had on teacher candidates'…

  3. 11 CFR 116.12 - Repayment of candidate loans of $250,000 or less.

    Science.gov (United States)

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Repayment of candidate loans of $250,000 or less. 116.12 Section 116.12 Federal Elections FEDERAL ELECTION COMMISSION GENERAL DEBTS OWED BY CANDIDATES AND POLITICAL COMMITTEES § 116.12 Repayment of candidate loans of $250,000 or less. (a)...

  4. Identifying the Relationship of Teacher Candidates' Humor Styles with Anxiety and Self-Compassion Levels

    Science.gov (United States)

    Aydin, Aydan

    2015-01-01

    Problem Statement: Teacher candidates who will soon be responsible for educating the future generations should possess certain characteristics. Specific teacher candidates should have specific characteristics taken into consideration: pre-school and primary teacher candidates should be seen as role models by younger students; psychological…

  5. Comparative Evaluation of Political Candidates: Implications for the Voter Decision Making Process.

    Science.gov (United States)

    Hellweg, Susan A.; King, Stephen W.

    A study was conducted to examine the evaluative criteria or schemata that voters use in making decisions about competing candidates. More specifically, the study sought to determine (1) whether the criteria that voters employ differ between the candidates, and (2) the relative importance of various candidate-specific criteria in the voting…

  6. 76 FR 77831 - 2012 Presidential Candidate Matching Fund Submission Dates and Post Date of Ineligibility Dates...

    Science.gov (United States)

    2011-12-14

    ... 2012 Presidential Candidate Matching Fund Submission Dates and Post Date of Ineligibility Dates To...: Notice of matching fund submission dates and submission dates for statements of net outstanding campaign... fund submission dates for publicly funded 2012 presidential primary candidates. Eligible candidates...

  7. Candidate gene markers for sperm quality and fertility in bulls

    Directory of Open Access Journals (Sweden)

    Chinmoy Mishra

    2013-10-01

    Full Text Available Fertility is one of the primary traits of reproduction in bulls. Decrease in fertility is a multifactorial condition and is verydifficult to diagnose. Among various causes genetic abnormality holds a major share. By identifying various genes that haveeffects on fertility the genetic cause behind subferility can be explored and also other non genetic factors can be identified.Advancement of molecular genetic tools now easily enables us to explore individual genes in animals. Identification of thesegenes will eventually lead to genome assembly and development of novel tools for analysing complex genetic traits. Thispaper gives a brief idea about the candidate genes for bull fertility, including genes encoding hormones and their receptors,proteins of the seminal plasma, proteins involved in spermatozoa-ovum binding and genes influencing sexual development.The chromosomal location and gene structure are described, based on the bovine genome assembly.

  8. Evaluation of Candidate Anti-Aids Drugs In Vitro

    Science.gov (United States)

    1991-05-31

    for the drug request form). The drugs were solubiized and delivered to the HlV labatory on the day of testing. All drugs were weighed in 5 mg amounas...EVALUATION OF CANDIDATE ANTI-AIDS DRUGS IN VITRO PRINCIPAL INVESTIGATOR: Dr. William M. Shannon CONTRACTING ORGANIZATION: Southern Research Institute...SEý89 rI ,E 4-IO S4Urf CjMrhCAfpW "va~luation of C.&riidate Anti-AlrxS Drug InV4=r L. Wmt~rnck. L-J Wi kf P.- ;01 1a r10 V RIC1 b ýkq~III coi4 3Ar1 00

  9. Expression studies of the obesity candidate gene FTO in pig

    DEFF Research Database (Denmark)

    Madsen, Majbritt Busk; Birck, Malene Muusfeldt; Fredholm, Merete

    2010-01-01

    Obesity is an increasing problem worldwide and research on candidate genes in good animal models is highly needed. The pig is an excellent model as its metabolism, organ size, and eating habits resemble that of humans. The present study is focused on the characterization of the fat mass and obesity...... associated gene (FTO) in pig. This gene has recently been associated with increased body mass index in several human populations. To establish information on the expression profile of FTO in the pig we performed quantitative PCR in a panel of adult pig tissues and in tissues sampled at different...... and cerebellum). Additionally, in order to see the involvement of the FTO gene in obesity, the changes in expression level were investigated in a nutritional study in brain of Gottingen minipigs under a high cholesterol diet. Significantly higher (P

  10. Event display of a H -> 4e candidate event

    CERN Multimedia

    ATLAS, Collaboration

    2012-01-01

    Event display of a H -> 4e candidate event with m(4l) = 124.5 (124.6) GeV without (with) Z mass constraint. The masses of the lepton pairs are 70.6 GeV and 44.7 GeV. The event was recorded by ATLAS on 18-May-2012, 20:28:11 CEST in run number 203602 as event number 82614360. The tracks and clusters of the two electron pairs are colored red and blue, respectively. The three displays on the right-hand side show the r-phi view of the event (top), a zoom into the vertex region, indicating that the 4 electrons originate from the same primary vertex (middle), and a Lego plot indicating the amount of transverse energy Et measured in the calorimeters (bottom).

  11. Event display of a H -> 4e candidate event

    CERN Multimedia

    ATLAS, Collaboration

    2012-01-01

    Event display (side view) of a H -> 4e candidate event with m(4l) = 124.5 (124.6) GeV without (with) Z mass constraint. The masses of the lepton pairs are 70.6 GeV and 44.7 GeV. The event was recorded by ATLAS on 18-May-2012, 20:28:11 CEST in run number 203602 as event number 82614360. The tracks of the two electron pairs are colored red and blue, respectively. Electron clusters in the LAr calorimeter are colored darkgreen. The three displays on the right-hand side show the r-phi view of the event (top), a zoom into the vertex region, indicating that the 4 electrons originate from the same primary vertex (middle), and a Lego plot indicating the amount of transverse energy Et measured in the calorimeters (bottom).

  12. Candidate eco-friendly gas mixtures for MPGDs

    CERN Document Server

    Saviano, Giovanna

    2015-01-01

    Modern gas detectors for the detection of elementary particles, and MPGDs in particular, require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work investigates the properties of potential eco-friendly gas candidate replacements. The aim is to discuss some of the important properties of gases for MPGDs, to list and summarize basic properties of eco-friendly refrigerants from the literature available, to discuss their properties for materials compatibility and safe use, and to make a prediction on selected parameters (i.e., ionization potentials, ionization pairs, etc) crucial for the performance of gas detectors considered by making use of both known parametrizations and quantum chemistry simulation codes.

  13. Computational identification of candidate nucleotide cyclases in higher plants

    KAUST Repository

    Wong, Aloysius Tze

    2013-09-03

    In higher plants guanylyl cyclases (GCs) and adenylyl cyclases (ACs) cannot be identified using BLAST homology searches based on annotated cyclic nucleotide cyclases (CNCs) of prokaryotes, lower eukaryotes, or animals. The reason is that CNCs are often part of complex multifunctional proteins with different domain organizations and biological functions that are not conserved in higher plants. For this reason, we have developed CNC search strategies based on functionally conserved amino acids in the catalytic center of annotated and/or experimentally confirmed CNCs. Here we detail this method which has led to the identification of >25 novel candidate CNCs in Arabidopsis thaliana, several of which have been experimentally confirmed in vitro and in vivo. We foresee that the application of this method can be used to identify many more members of the growing family of CNCs in higher plants. © Springer Science+Business Media New York 2013.

  14. A New Candidate for Guided Tissue Regeneration: Biomimetic Eggshell Membrane

    Directory of Open Access Journals (Sweden)

    Yuanyuan Duan

    2011-01-01

    Full Text Available Periodontal disease that involves the deterioration of tooth supporting structures is the primary cause of tooth loss among adults. Guided tissue regeneration (GTR technique is a commonly used surgical procedure for the treatment of periodontal diseases by using a barrier membrane. Natural eggshell membrane (ESM is a semi-permeable membrane consisting of two individual layers with fibrous meshwork structures. With the aid of successful preparation of soluble eggshell membrane proteins (SEP from natural ESM in the previous study, we hypothesized that one new type of biomimetic nanofibrous eggshell membrane could be successfully constructed by sequential electrospinning method. This proposed membrane is composed of two interconnected nanofibrous layers with different density and porosity which can mimic the composition, morphology and structure of natural ESM. It is expected to greatly enhance the periodontal tissue regeneration as well as physically maintain the space for tissue repair, thus to be a promising and cost-effective GTR membrane candidate.

  15. Candidate driver genes in microsatellite-unstable colorectal cancer

    DEFF Research Database (Denmark)

    Alhopuro, Pia; Sammalkorpi, Heli; Niittymäki, Iina;

    2012-01-01

    . Here, we evaluated somatic mutations in microsatellite repeats of 790 genes chosen based on reduced expression in MSI CRC and existence of a coding mononucleotide repeat of 6–10 bp in length. All the repeats were initially sequenced in 30 primary MSI CRC samples and whenever frameshift mutations were...... types (A/T and C/G, 6–10 bp). Along with several know target genes, including TGFBR2, ACVR2, and MSH3, six novel candidate driver genes emerged that harbored significantly more mutations than identical control repeats. The mutation frequencies in 100 MSI CRC samples were 51% in G8 of GLYR1, 47% in T9...... genes that when mutated are likely to contribute to MSI CRC development....

  16. Cognitive Deficits in Symptomatic and Asymptomatic Carotid Endarterectomy Surgical Candidates

    Science.gov (United States)

    Jackson, Daren C.; Sandoval-Garcia, Carolina; Rocque, Brandon G.; Wilbrand, Stephanie M.; Mitchell, Carol C.; Hermann, Bruce P.; Dempsey, Robert J.

    2016-01-01

    The role played by vessel disease in stroke-related cognition dysfunction is unclear. We assessed the impact of significant atherosclerotic disease on cognition—even in patients asymptomatic for stroke. We hypothesized that patients would perform poorly relative to controls, but that symptomatic/asymptomatic status (history of stroke/transient ischemic attack) would have no effect. Fifty-two carotid endarterectomy candidates with >60% carotid stenosis and 17 controls underwent a 60-min neuropsychological test protocol. Symptomatic and asymptomatic patients showed deficits in executive function, delayed verbal recall, and general knowledge. Patients symptomatic for stroke also performed worse on tests of language and motor/visuomotor ability. Symptomatic and asymptomatic patients differed in working memory and language task performance. Although all patients showed deficits in executive function and memory, only symptomatic patients showed additional deficits in language and motor function. Cognitive abnormalities in patients viewed as “asymptomatic” for stroke underscore the need for early identification and treatment. PMID:26663810

  17. Candidate gene copy number analysis by PCR and multicapillary electrophoresis.

    Science.gov (United States)

    Szantai, Eszter; Elek, Zsuzsanna; Guttman, András; Sasvari-Szekely, Maria

    2009-04-01

    Genetic polymorphisms are often considered as risk factors of complex diseases serving as valuable and easily detectable biomarkers, also stable during the whole lifespan. A novel type of genetic polymorphism has been identified just recently, referred to as gene copy number variation (CNV) or copy number polymorphism. CNV of glycogen synthase kinase 3 beta and its adjacent gene, Nr1i2 (pregnane X receptor isoform), has been reported to associate with bipolar depression. In our study we introduced multicapillary electrophoresis for gene copy number analysis as an affordable alternative to real-time PCR quantification with TaqMan gene probes. Our results show the reliability of the developed method based on conventional PCR followed by separation of products by multicapillary electrophoresis with quantitative evaluation. This method can be readily implemented for the analysis of candidate gene CNVs in high throughput clinical laboratories and also in personalized medicine care of depression-related risk factors.

  18. Vaccines for leishmaniasis: from proteome to vaccine candidates.

    Science.gov (United States)

    Schroeder, Juliane; Aebischer, Toni

    2011-01-01

    Leishmania spp. cause a wide spectrum of tropical diseases which are threatening an estimated 350 million people around the globe. While in most cases non-fatal, the disease is associated with high morbidity, social stigmata and poverty. However, the most severe form visceral leishmaniasis can be fatal if left untreated. Chemotherapeutics are available but show high toxicity, costs and are prone to resistance development due to prolonged treatment periods. Healing is associated with a life-long resistance to re-infection and this argues for the feasibility of vaccination. However, despite much effort, no such vaccine has become available yet. Here, the status of vaccine development in this field is briefly summarized before the focus is set on the promise of reverse vaccinology for anti-Leishmania vaccine development in the post-genomic era. We report on our own experience with this approach using an instructive example of successful candidate vaccine antigen identification.

  19. Maximized ExoEarth Candidate Yields for Starshades

    CERN Document Server

    Stark, Christopher C; Lisman, Doug; Cady, Eric; Savransky, Dmitry; Roberge, Aki; Mandell, Avi M

    2016-01-01

    The design and scale of a future mission to directly image and characterize potentially Earth-like planets will be impacted, to some degree, by the expected yield of such planets. Recent efforts to increase the estimated yields, by creating observation plans optimized for the detection and characterization of Earth-twins, have focused solely on coronagraphic instruments; starshade-based missions could benefit from a similar analysis. Here we explore how to prioritize observations for a starshade given the limiting resources of both fuel and time, present analytic expressions to estimate fuel use, and provide efficient numerical techniques for maximizing the yield of starshades. We implemented these techniques to create an approximate design reference mission code for starshades and used this code to investigate how exoEarth candidate yield responds to changes in mission, instrument, and astrophysical parameters for missions with a single starshade. We find that a starshade mission operates most efficiently so...

  20. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    Directory of Open Access Journals (Sweden)

    Yufan Cao

    2016-01-01

    Full Text Available Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials.

  1. Women candidates: the relationships between gender, media and discourse

    Directory of Open Access Journals (Sweden)

    Claudia Maria Finamore

    Full Text Available On this paper we discuss, within the cross over of two representations - woman and politic function - the media’s power to influence voters’ choices and their roles as interpreters of media messages. Under a position that understands the relativity of the media’s power, we set the idea of gender discourse as a mediator of its influence. Whereas literature shows how a candidate suffers an important effect of media exposition, transformed in a marketing product, we suggest that women in politics suffer from the stereotype that states "women’s place is at home". We conclude that women politic participation is strongly linked to the way in which they are represented in the common sense and a change in the hegemonic discourses about women that cross individuals and social groups becomes necessary as to have this situation modified.

  2. Two new high energy gamma-ray blazar candidates

    CERN Document Server

    Campana, R; Bernieri, E; Massaro, E

    2016-01-01

    We report the detection of two new gamma-ray sources in the Fermi-LAT sky (Pass 8) at energies higher than 20 GeV, and confirmed at lower energies, using a source detection tool based on the Minimum Spanning Tree algorithm. One of these sources, at a Galactic latitude of about -4{\\deg}, is a new discovery, while the other was previously reported above 50 GeV in the 2FHL catalogue. We searched for archival multi-wavelength data of possible counterparts and found interesting candidates. Both objects are radio sources and their WISE infrared colours are typical of blazars. While for the former source no optical spectra are available, for the latter a puzzling optical spectrum corresponding to a white dwarf star is found in the 6dF database. We discuss the spectral energy distributions of both sources and possible interpretations.

  3. Preselecting AGN candidates from multi-wavelength data by ADTree

    Science.gov (United States)

    Zhang, Yanxia; Zheng, Hongwen; Zhao, Yongheng

    2005-03-01

    With the information era in astronomy coming, this "data avalanche" may provide many answers to important problems in contemporary astrophysics. The most important problem is sifting through massive amounts of data to mine knowledge. In this paper, we positionally cross-identify multi-wavelength data from optical, near-infrared, and x-ray bands, and then employ alternating decision trees (adtree) to quickly and robustly separate AGN candidates to a high degree of accuracy. We emphasise the application of the method due to the development of large survey projects and the establishment of the virtual observatory, and conclude that the application of data mining algorithms in astronomy is of great importance to discover new knowledge impossible to obtain before, and promote the development of astronomy.

  4. Herschel Reveals Massive Cold Clump Candidates in NGC 7538

    Science.gov (United States)

    Fallscheer, Cassandra; Reid, Mike; Di Francesco, James; Martin, Peter; Hill, Tracey

    2013-07-01

    Observations of the high-mass star formation region NGC 7538 taken with the Herschel Space Observatory were made at 70, 160, 250, 350, and 500 micron as part of the Herschel imaging study of OB Young Stellar objects (HOBYS) Key Programme. Within the one square degree field, we identify 780 dense sources and classify 224 of those. With the intention of investigating the existence of cold massive starless or class 0-like clumps that would have the potential to form intermediate- to high-mass stars, we further isolate 13 clumps as the most likely candidates for follow-up studies. A peculiar feature in the observations is a large, nearly complete ring of material. The evacuated ring is of unknown origin and hosts a number of the detected sources.

  5. Spectroscopic analysis of four post-AGB candidates

    CERN Document Server

    Molina, R E; Pereira, C B; Ferro, A Arellano; Muneer, S

    2014-01-01

    We have done a detailed abundance analysis of four unexplored candidate post- Asymptotic Giant Branch(AGB) stars IRAS 13110 - 6629, IRAS 17579 - 3121, IRAS 18321 - 1401 and IRAS 18489 - 0629 using high resolution spectra. We have constructed Spectral Energy Distributions (SED) for these objects using the existing photometric data combined with infrared (IR) fluxes. For all sample stars, the SEDs exhibit double peaked energy distribution with well separated IR peaks showing the presence of dusty circumstellar material. The CNO abundances indicate the production of N via CN cycling, but observed [C/Fe] indicates the mixing of carbon produced by He burning by third dredge up although C/O ratio remains less that 1. A moderate DG effect is clearly seen for IRAS 18489 - 0629 and IRAS 17579 - 3121 while a large scatter observed in depletion plots for IRAS 18321 - 1401 and IRAS 13110 - 6629 indicate the presence of other processes affecting the observed abundance pattern.

  6. Transforming fragments into candidates: small becomes big in medicinal chemistry.

    Science.gov (United States)

    de Kloe, Gerdien E; Bailey, David; Leurs, Rob; de Esch, Iwan J P

    2009-07-01

    Fragment-based drug discovery (FBDD) represents a logical and efficient approach to lead discovery and optimisation. It can draw on structural, biophysical and biochemical data, incorporating a wide range of inputs, from precise mode-of-binding information on specific fragments to wider ranging pharmacophoric screening surveys using traditional HTS approaches. It is truly an enabling technology for the imaginative medicinal chemist. In this review, we analyse a representative set of 23 published FBDD studies that describe how low molecular weight fragments are being identified and efficiently transformed into higher molecular weight drug candidates. FBDD is now becoming warmly endorsed by industry as well as academia and the focus on small interacting molecules is making a big scientific impact.

  7. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    Science.gov (United States)

    Cao, Yufan; Qiao, Hongbin; Shi, Yanli; Han, Yu; Liu, Jinming; Li, Hao; Lu, Ke; Lin, Jiaojiao

    2016-01-01

    Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl) has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj) eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials. PMID:27957496

  8. Space exploration initiative candidate nuclear propulsion test facilities

    Science.gov (United States)

    Baldwin, Darrell; Clark, John S.

    1993-01-01

    One-page descriptions for approximately 200 existing government, university, and industry facilities which may be available in the future to support SEI nuclear propulsion technology development and test program requirements are provided. To facilitate use of the information, the candidate facilities are listed both by location (Index L) and by Facility Type (Index FT). The included one-page descriptions provide a brief narrative description of facility capability, suggest potential uses for each facility, and designate a point of contact for additional information that may be needed in the future. The Nuclear Propulsion Office at NASA Lewis presently plans to maintain, expand, and update this information periodically for use by NASA, DOE, and DOD personnel involved in planning various phases of the SEI Nuclear Propulsion Project.

  9. Proteins of Bartonella bacilliformis: Candidates for Vaccine Development

    Directory of Open Access Journals (Sweden)

    Cesar Henriquez-Camacho

    2015-01-01

    Full Text Available Bartonella bacilliformis is the etiologic agent of Carrión’s disease or Oroya fever. B. bacilliformis infection represents an interesting model of human host specificity. The notable differences in clinical presentations of Carrión’s disease suggest complex adaptations by the bacterium to the human host, with the overall objectives of persistence, maintenance of a reservoir state for vectorial transmission, and immune evasion. These events include a multitude of biochemical and genetic mechanisms involving both bacterial and host proteins. This review focuses on proteins involved in interactions between B. bacilliformis and the human host. Some of them (e.g., flagellin, Brps, IalB, FtsZ, Hbp/Pap31, and other outer membrane proteins are potential protein antigen candidates for a synthetic vaccine.

  10. Current understanding of increased insulin sensitivity after exercise - emerging candidates

    DEFF Research Database (Denmark)

    Maarbjerg, Stine Just; Sylow, Lykke; Richter, Erik

    2011-01-01

    insulin sensitivity. It is believed that increased sarcolemmal content of the glucose transporter GLUT4 can explain the phenomenon to some extent. Surprisingly no improvement in the proximal insulin signaling pathway is observed at the level of the insulin receptor, IRS1, PI3K or Akt. Recently more distal...... signaling component in the insulin signaling pathway such as aPKC, Rac1, TBC1D4 and TBC1D1 have been described. These are all affected by both insulin and exercise which means that they are likely converging points in promoting GLUT4 translocation and therefore possible candidates for regulating insulin...... in signaling to GLUT4 translocation, factors influencing the trans-sarcolemmal glucose concentration gradient might also be important. With regard to the interstitial glucose concentration microvascular perfusion is particular relevant as correlative evidence supports a connection between insulin sensitivity...

  11. On the occurrence of glitches in pulsar free precession candidates

    CERN Document Server

    Jones, D I; Prix, R

    2016-01-01

    The timing properties of radio pulsars provide a unique probe of neutron star interiors. Recent observations have uncovered quasi-periodicities in the timing and pulse properties of some pulsars, a phenomenon that has often been attributed to free precession of the neutron star, with profound implications for the distribution of superfluidity and superconductivity in the star. We advance this programme by developing consistency relations between free precession and pulsars glitches, and show that there are difficulties in reconciling the two phenomena in some precession candidates. This indicates that either the precession model used here needs to be modified, or some other phenomenon is at work in producing the quasi-periodicities, or even that there is something missing in terms of our understanding of glitches.

  12. Some more Exotic Dark Matter Candidates: GUT Balls, Fermi Balls...

    CERN Document Server

    Sivaram, C

    2011-01-01

    The nature of dark matter (DM), which is supposed to constitute about one-fourth of the universe, is still a mystery. There is evidence that much of the DM may be made up of as yet undiscovered particles with several experiments all over the world trying to detect these. In this article we introduce some new candidates which are exotic in nature but still are consistent with known physics. We look at DM objects that can be formed by the balance of gravity with the four-fermion force, nuclear tension, etc. We see that their radii are much larger than their corresponding Schwarzschild radius; hence they are distinct from Hawking primordial black holes. We have determined their mass and the required number densities to account for the DM in the galaxy and possible ways of detecting them.

  13. Disformal scalars as dark matter candidates — Branon phenomenology

    Science.gov (United States)

    Cembranos, Jose A. R.; Maroto, Antonio L.

    2016-05-01

    Scalar particles coupled to the Standard Model fields through a disformal coupling arise in different theories, such as massive gravity or braneworld models. We will review the main phenomenology associated with such particles. Distinctive disformal signatures could be measured at colliders and with astrophysical observations. The phenomenological relevance of the disformal coupling demands the introduction of a set of symmetries, which may ensure the stability of these new degrees of freedom. In such a case, they constitute natural dark matter candidates since they are generally massive and weakly coupled. We will illustrate these ideas by paying particular attention to the branon case, since these questions arise naturally in braneworld models with low tension, where they were first discussed.

  14. Disformal scalars as dark matter candidates: Branon phenomenology

    CERN Document Server

    Cembranos, Jose A R

    2016-01-01

    Scalar particles coupled to the Standard Model fields through a disformal coupling arise in different theories, such as massive gravity or brane-world models. We will review the main phenomenology associated with such particles. Distinctive disformal signatures could be measured at colliders and with astrophysical observations. The phenomenological relevance of the disformal coupling demands the introduction of a set of symmetries, which may ensure the stability of these new degrees of freedom. In such a case, they constitute natural dark matter candidates since they are generally massive and weakly coupled. We will illustrate these ideas by paying particular attention to the branon case, since these questions arise naturally in brane-world models with low tension, where they were first discussed.

  15. A New Optical Survey of Supernova Remnant Candidates in M31

    CERN Document Server

    Lee, Jong Hwan

    2014-01-01

    We present a survey of optically emitting supernova remnants (SNRs) in M31 based on H$\\alpha$ and [SII] images in the Local Group Survey. Using these images, we select objects that have [SII]:H$\\alpha$ $>$ 0.4 and circular shapes. We find 76 new SNR candidates. We also inspect 234 SNR candidates presented in previous studies, finding that only 80 of them are SNR candidates according to our criteria. Combining them with the new candidates, we produce a master catalog of 156 SNR candidates in M31. We classify these SNR candidates according to two criteria: the SNR progenitor type [Type Ia and core-collapse (CC) SNRs] and the morphological type. Type Ia and CC SNR candidates make up 23% and 77%, respectively, of the total sample. Most of the CC SNR candidates are concentrated in the spiral arms, while the Type Ia SNR candidates are rather distributed over the entire galaxy, including the inner region. The CC SNR candidates are brighter in H$\\alpha$ and [SII] than the Type Ia SNR candidates. We derive a cumulativ...

  16. Candidate genes for performance in horses, including monocarboxylate transporters

    Directory of Open Access Journals (Sweden)

    Inaê Cristina Regatieri

    Full Text Available ABSTRACT: Some horse breeds are highly selected for athletic activities. The athletic potential of each animal can be measured by its performance in sports. High athletic performance depends on the animal capacity to produce energy through aerobic and anaerobic metabolic pathways, among other factors. Transmembrane proteins called monocarboxylate transporters, mainly the isoform 1 (MCT1 and its ancillary protein CD147, can help the organism to adapt to physiological stress caused by physical exercise, transporting lactate and H+ ions. Horse breeds are selected for different purposes so we might expect differences in the amount of those proteins and in the genotypic frequencies for genes that play a significant role in the performance of the animals. The study of MCT1 and CD147 gene polymorphisms, which can affect the formation of the proteins and transport of lactate and H+, can provide enough information to be used for selection of athletic horses increasingly resistant to intense exercise. Two other candidate genes, the PDK4 and DMRT3, have been associated with athletic potential and indicated as possible markers for performance in horses. The oxidation of fatty acids is highly effective in generating ATP and is controlled by the expression of PDK4 (pyruvate dehydrogenase kinase, isozyme 4 in skeletal muscle during and after exercise. The doublesex and mab-3 related transcription factor 3 (DMRT3 gene encodes an important transcription factor in the setting of spinal cord circuits controlling movement in vertebrates and may be associated with gait performance in horses. This review describes how the monocarboxylate transporters work during physical exercise in athletic horses and the influence of polymorphisms in candidate genes for athletic performance in horses.

  17. VALFAST: Secure Probabilistic Validation of Hundreds of Kepler Planet Candidates

    Science.gov (United States)

    Morton, Tim; Petigura, E.; Johnson, J. A.; Howard, A.; Marcy, G. W.; Baranec, C.; Law, N. M.; Riddle, R. L.; Ciardi, D. R.; Robo-AO Team

    2014-01-01

    The scope, scale, and tremendous success of the Kepler mission has necessitated the rapid development of probabilistic validation as a new conceptual framework for analyzing transiting planet candidate signals. While several planet validation methods have been independently developed and presented in the literature, none has yet come close to addressing the entire Kepler survey. I present the results of applying VALFAST---a planet validation code based on the methodology described in Morton (2012)---to every Kepler Object of Interest. VALFAST is unique in its combination of detail, completeness, and speed. Using the transit light curve shape, realistic population simulations, and (optionally) diverse follow-up observations, it calculates the probability that a transit candidate signal is the result of a true transiting planet or any of a number of astrophysical false positive scenarios, all in just a few minutes on a laptop computer. In addition to efficiently validating the planetary nature of hundreds of new KOIs, this broad application of VALFAST also demonstrates its ability to reliably identify likely false positives. This extensive validation effort is also the first to incorporate data from all of the largest Kepler follow-up observing efforts: the CKS survey of ~1000 KOIs with Keck/HIRES, the Robo-AO survey of >1700 KOIs, and high-resolution images obtained through the Kepler Follow-up Observing Program. In addition to enabling the core science that the Kepler mission was designed for, this methodology will be critical to obtain statistical results from future surveys such as TESS and PLATO.

  18. Validation of transting planet candidates: a Bayesian view

    Science.gov (United States)

    Díaz, Rodrigo Fernando; Almenara, Jose Manuel; Santerne, Alexandre

    2015-08-01

    Transiting candidate validation is essentially a Bayesian model comparison problem: different models, all explaining the observations comparably well, compete for the support of the available data. It has, however, two particularities that render it very complex and difficult to tackle: i) the relevant data sets are of diverse nature (transit light curves, broad band photometry, high angular resolution images, radial velocity observations, etc.), and ii) the models representing each hypothesis are highly non-linear and in some cases make the computation of the likelihood very time consuming.Despite its clear Bayesian nature, the planet validation problem has received in the past mainly a frequentist treatment (BLENDER). Other techniques exist, but they employ unrealistic models that increase speed but only partially exploit the available datasets (ValFast).The Planet Analysis and Small Transit Investigation Software (PASTIS) was developped keeping these issues and the characteristics of the problem in mind. It aims at computing the Bayesian evidence for a full set of false positive scenarios and the planet hypothesis, modelling in all cases the available data self-consistently, thus producing robust and rigorous Bayes factor for all models of interest. Its object-oriented architecture also permits constructing a vast set of false positive models easily.I will review some key results of the planet validation technique, showing the limitations and dangers of some approaches and of the validation technique in general. I will also describe the PASTIS tool and present out results on CoRoT-22 b, Kepler-22 b, and other transiting candidates.

  19. A candidate multimodal functional genetic network for thermal adaptation

    Directory of Open Access Journals (Sweden)

    Katharina C. Wollenberg Valero

    2014-09-01

    Full Text Available Vertebrate ectotherms such as reptiles provide ideal organisms for the study of adaptation to environmental thermal change. Comparative genomic and exomic studies can recover markers that diverge between warm and cold adapted lineages, but the genes that are functionally related to thermal adaptation may be difficult to identify. We here used a bioinformatics genome-mining approach to predict and identify functions for suitable candidate markers for thermal adaptation in the chicken. We first established a framework of candidate functions for such markers, and then compiled the literature on genes known to adapt to the thermal environment in different lineages of vertebrates. We then identified them in the genomes of human, chicken, and the lizard Anolis carolinensis, and established a functional genetic interaction network in the chicken. Surprisingly, markers initially identified from diverse lineages of vertebrates such as human and fish were all in close functional relationship with each other and more associated than expected by chance. This indicates that the general genetic functional network for thermoregulation and/or thermal adaptation to the environment might be regulated via similar evolutionarily conserved pathways in different vertebrate lineages. We were able to identify seven functions that were statistically overrepresented in this network, corresponding to four of our originally predicted functions plus three unpredicted functions. We describe this network as multimodal: central regulator genes with the function of relaying thermal signal (1, affect genes with different cellular functions, namely (2 lipoprotein metabolism, (3 membrane channels, (4 stress response, (5 response to oxidative stress, (6 muscle contraction and relaxation, and (7 vasodilation, vasoconstriction and regulation of blood pressure. This network constitutes a novel resource for the study of thermal adaptation in the closely related nonavian reptiles and

  20. Neurological soft signs as a candidate for endophenotype of schizophrenia

    Directory of Open Access Journals (Sweden)

    Kałużyńska, Olga

    2014-02-01

    Full Text Available A concept of an endophenotype, also termed as an internal endophenotype, is used in genetic studies on psychiatric disorders. Neurological soft signs are also considered candidates for endophenotypes of schizophrenia. Neurological soft signs are, objectively measured, non-localizing abnormalities, not related to impairment of a specific brain region, reflecting improper corical-subcorical and intercortical connections. This paper presents the main domains of NSS, methods of measurement of NSS, their neuroanatomical substrate, association of NSS with schizophrenia symptoms the and analysis of the literature in order to check whether NSS meet the criteria of the phenotype. A marker can be considered a phenotype if it meets the following criteria: 1 association with a disease in a population, 2 heritability, 3 state-independence, 4 familial association (the endophenotype is more prevalent in the affected individuals, their affected and non-affected family members in comparison to the normal population, 5 co-segregation ( the endophenotype is more prevalent among ill family members of ill probands compared with healthy relatives. Currently, there is an ample evidence that the NSS, especially these representing impaired motor coordination, meet certain criteria of an endophenotype. However, there are still several unresolved questions concerning NSS: studies on relatives of schizophrenic patients included small groups of subjects, many of the studies included individuals with schizophrenia, as well as schizophrenia spectrum disorders, the available date-base of twins (schizophrenia-concordant and schizophrenia non-concordant is not sufficiently large, there are too few studies evaluating the relationship of NSS and individual genes, there are no objective and quantitative methods of measurement of NSS. Therefore, NSS still represent only candidates for an endophenotype of schizophrenia. Finding correlations of selected NSS with other endophenotypes