Science.gov

Sample records for candidate xte j1650-500

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

    NASA Technical Reports Server (NTRS)

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Long-Term Spectral and Timing Behavior of the Black Hole Candidate XTE J1908+094

    NASA Technical Reports Server (NTRS)

    Gogus, Ersin; Finger, Mark H.; Kouveliotou, Chryssa; Woods, Peter M.; Patel, Sandeep K.; Ruppen, Michael; Swank, Jean H.; Markwardt, Craig B.; VanDerKlis, Michiel

    2004-01-01

    We present the long-term X-ray light curves and detailed spectral and timing analyses of XTE J1908+094 using the Rossi X-Ray Timing Explorer Proportional Counter Array observations covering two outbursts in 2002 and early 2003. At the onset of the first outburst, the source was found in a spectrally low/hard state lasting for approx.40 days, followed by a 3 day long transition to the high/soft state. The source flux (in 2- 10 keV) reached approx.100 mcrab on 2002 April 6, then decayed rapidly. In power spectra, we detect strong band-limited noise and varying low- frequency quasi-periodic oscillations that evolved from approx.0.5 to approx.5 Hz during the initial low/hard state of the source. We find that the second outburst closely resembled the spectral evolution of the first. The X-ray transient s overall outburst characteristics led us to classify XTE J1908+094 as a black hole candidate. Here we also derive precise X-ray position of the source using Chandra observations that were performed during the decay phase of the first outburst and following the second outburst.

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

    NASA Astrophysics Data System (ADS)

    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 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) photometry and polarimetry and rare mid-IR imaging (8-12 ?m) when the source is nearing quiescence. The fading jet component, and possibly the companion star, may contribute to the NIR flux. We derive deep mid-IR flux upper limits and NIR linear polarization upper limits. With the inclusion of radio data, we measure an almost flat jet spectral index between radio and optical; Fν∝ν˜+0.05. The data favour the jet break to optically thin emission to reside in the IR, but may shift to frequencies as high as the optical or UV during the peak of the flare. Based on observations collected at the European Southern Observatory, Chile, under ESO Programme ID 086.D-0610, the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias and the Faulkes Telescopes at Haleakala, Maui, USA and Siding Spring, Australia.

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Correlated fast X-ray and optical variability in the black-hole candidate XTE J1118+480.

    PubMed

    Kanbach, G; Straubmeier, C; Spruit, H C; Belloni, T

    2001-11-01

    Black holes become visible when they accrete gas, a common source of which is a close stellar companion. The standard theory for this process (invoking a 'thin accretion disk') does not explain some spectacular phenomena associated with these systems, such as their X-ray variability and relativistic outflows, indicating some lack of understanding of the actual physical conditions. Simultaneous observations at multiple wavelengths can provide strong constraints on these conditions. Here we report simultaneous high-time-resolution X-ray and optical observations of the transient source XTE J1118+480, which show a strong but puzzling correlation between the emissions. The optical emission rises suddenly following an increase in the X-ray output, but with a dip 2-5 seconds in advance of the X-rays. This result is not easy to understand within the simplest model of the optical emission, where the light comes from reprocessed X-rays. It is probably more consistent with an earlier suggestion that the optical light is cyclosynchrotron emission that originates in a region about 20,000 km from the black hole. We propose that the time dependence is evidence for a relatively slow (<0.1c), magnetically controlled outflow. PMID:11700550

  8. Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidate MoxW1 -xTe2

    NASA Astrophysics Data System (ADS)

    Belopolski, Ilya; Xu, Su-Yang; Ishida, Yukiaki; Pan, Xingchen; Yu, Peng; Sanchez, Daniel S.; Zheng, Hao; Neupane, Madhab; Alidoust, Nasser; Chang, Guoqing; Chang, Tay-Rong; Wu, Yun; Bian, Guang; Huang, Shin-Ming; Lee, Chi-Cheng; Mou, Daixiang; Huang, Lunan; Song, You; Wang, Baigeng; Wang, Guanghou; Yeh, Yao-Wen; Yao, Nan; Rault, Julien E.; Le Fèvre, Patrick; Bertran, François; Jeng, Horng-Tay; Kondo, Takeshi; Kaminski, Adam; Lin, Hsin; Liu, Zheng; Song, Fengqi; Shin, Shik; Hasan, M. Zahid

    2016-08-01

    It has recently been proposed that electronic band structures in crystals can give rise to a previously overlooked type of Weyl fermion, which violates Lorentz invariance and, consequently, is forbidden in particle physics. It was further predicted that MoxW1 -xTe2 may realize such a type-II Weyl fermion. Here, we first show theoretically that it is crucial to access the band structure above the Fermi level ɛF to show a Weyl semimetal in MoxW1 -xTe2 . Then, we study MoxW1 -xTe2 by pump-probe ARPES and we directly access the band structure >0.2 eV above ɛF in experiment. By comparing our results with ab initio calculations, we conclude that we directly observe the surface state containing the topological Fermi arc. We propose that a future study of MoxW1 -xTe2 by pump-probe ARPES may directly pinpoint the Fermi arc. Our work sets the stage for the experimental discovery of the first type-II Weyl semimetal in MoxW1 -xTe2 .

  9. XTE J1908+094

    NASA Technical Reports Server (NTRS)

    Woods, P. M.; Kouveliotou, C.; Finger, M. H.; Gogus, E.; Swank, J.; Markwardt, C.; Strohmayer, T.; Six, N. Frank (Technical Monitor)

    2002-01-01

    Goddard Space Flight Center reports the serendipitous discovery of a new x-ray transient, XTE J1908+094, in RXTE (Rossi X-ray Timing Explorer) PCA (Proportional Counter Array) observations of the soft-gamma-ray repeater SGR 1900+14, triggered following the burst activity on Feb. 17-18 (GCN 1253). These observations failed to detect the 5.2-s SGR pulsations, pointing towards a possible new source as the origin of the high x-ray flux. An RXTE PCA scan of the region around SGR 1900+14 on Feb. 21 was consistent with emission only from known sources (and no new sources). However, the scans required SGR 1900+14 to be 20 times brighter than its quiescent flux level (GCN 1256). A Director's Discretionary Time Chandra observation on Mar. 11 showed that the SGR was quiescent and did not reveal any new source within the Chandra ACIS (Advanced CCD (charge coupled device) Imaging Spectrometer) field-of-view. A subsequent RXTE PCA scan on Mar. 17, taken in combination with the first scan, required that a new source be included in the fit. The best-fit position is R.A. 19h 08m 50s, Decl. = +9 22 deg .5 (equinox J2000.0; estimated 2 deg systematic error radius), or approximately 24 deg away from the SGR source. The source spectrum (2-30 kev) can be best fit with a power-law function including photoelectric absorption (column density N_h = 2.3 x 10(exp 22), photon index = 1.55). Iron line emission is present, but may be due to the Galactic ridge. Between Feb. 19 and Mar. 17, the source flux (2-10 keV) has risen from 26 to 64 mCrab. The power spectrum is flat between 1 mHz and 0.1 Hz, falling approximately as 1/f**0.5 up to 1 Hz. At 1 Hz is seen a broad quasiperiodic oscillation peak and a break to a 1/f**2 power law, which continues to 4 Hz. The fractional rms (root mean square) amplitude from 1 mHz to 4 Hz is 43 percent. No coherent pulsations are seen between 0.001 and 1024 Hz. The authors conclude that XTE J1908+094 is a new blackhole candidate.

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

    NASA Astrophysics Data System (ADS)

    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

  11. Coordinated ASCA/EUVE/XTE Observations of Algol

    NASA Technical Reports Server (NTRS)

    Stern, Robert A.

    1997-01-01

    EUVE, Advanced Satellite for Cosmology and Astrophysics (ASCA), and X-ray Timing Explorer (XTE) observed the eclipsing binary Algol (Beta Per) from 1-7 Feb 1996. The coordinated observation covered approx. 2 binary orbits of the system, with a net exposure of approx. 160 ksec for EUVE, 40 ksec for ASCA (in 4 pointings), and 90 ksec for XTE (in 45 pointings). We discuss results of modeling the combined EUVE, ASCA, and XTE data using continuous differential emission measure distributions, and provide constraints on the abundance in the Algol system.

  12. Delta XTE Spacecraft Arrives at CCAS Skid Strip

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Footage shows the U.S Air Force Aircraft "Air Mobility Command" approaching, and landing at the Cape Canaveral Air Station Skid Strip (CCAS). The truck carrying the Delta XTE Spacecraft is also shown as it leaves the Air Mobility Command.

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

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Wijnands, R.; Homan, J.; Belloni, T.; Pooley, D.; Kouveliotou, C.; vanderKlis, M.; Lewin, W. H. G.; Whitaker, Ann F. (Technical Monitor)

    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" canonical black hole state. A strong (5-8% RMS) quasi-periodic oscillation (QPO) is found between 249-278 Hz; this may represent the first recurrence of the same high-frequency QPO in subsequent outbursts of a transient black hole candidate. We also present possible evidence for a lower-frequency QPO at approximately 187 Hz, also reported previously and likely present simultaneously with the higher-frequency QPO. 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.

  14. A new outburst of XTE J1739-285

    NASA Astrophysics Data System (ADS)

    Maccarone, Thomas J.; Bandyopadhyay, Reba; Kennea, Jamie

    2012-09-01

    With our program of Swift monitoring of the Galactic Bulge region (Atel #4109), we detect renewed activity of the X-ray binary XTE J1739-285. Using the pipeline of Phil Evans (Evans et al. 2007, A&A, 469, 379), we find that the source count rate is about 34 counts/sec in data taken on 4 September from 5:33 to 12:02 UT, with 372 seconds of exposure time on source. We note that the source is heavily piled up, since the data were taken in photon counting mode as part of an imaging survey and hence the count rate should be taken with caution.

  15. Additional Observations of XTE J1752-223

    NASA Astrophysics Data System (ADS)

    Markwardt, C. B.; Barthelmy, S. D.; Evans, P. A.; Swank, J. H.

    2009-10-01

    We report on additional observations of XTE J1752-223, a new transient recently reported active (ATEL #2258). Swift performed a dedicated follow-up observation at 2009-10-25 at 06:08 UT. A bright X-ray source was detected by the XRT instrument, heavily piled up. The best fit position from XRT is, R.A. = 268.06307 = 17:52:15.14 ; Dec. = -22.34274 = -22:20:33.8 (J2000) with estimated position error of about 5 arcsec.

  16. RXTE Spectral Study of the New X-ray Transient XTE J1859+226

    NASA Astrophysics Data System (ADS)

    Focke, W. B.; Markwardt, C. B.; Swank, J. H.; Taam, R. E.

    1999-12-01

    The transient galactic black hole candidate XTE J1859+226 was discovered by the RXTE All Sky Monitor (ASM) on 1999 October 9, within a day after its outburst began. Pointed observations with RXTE began on 1999 October 10.57, and continued at a rate of about twice per day. Preliminary results of fits to PCA and HEXTE spectra for October 9--14 show that a simple absorbed powerlaw is insufficient to model the data. The fit is greatly improved by using an absorbed cutoff powerlaw with reflection. The photon index rose from 1.8 on October 9 to 3.2 on October 14. The cutoff energy started near 100 keV, dropped to 50 keV, then rose to an undetectable level between October 12.86 and October 13.11, potentially indicating a state change. We will present spectral analysis of these and later data, along with comparison of the spectral and timing properties. This work was funded by NASA.

  17. Observational Signatures of Black Holes: Spectral and Temporal Features of XTE J1550-564

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Shrader, C. R.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The theoretical predictions of the converging inflow, or Bulk-Motion Comptonization model are discussed and some predictions are compared to X- and gamma-ray observations of the high-soft state of Galactic black hole candidate XTE J1550+564. The approx. 10(exp 2)-Hz QPO phenomenon tends to be detected in the high-state at times when the bolometric luminosity surges and the hard-powerlaw spectral component is dominant. Furthermore, the power in these features increases with energy. We offer interpretation of this phenomenon, as oscillations of the innermost part of the accretion disk, which in turn supplies the seed photons for the converging inflow where the hard power-law is formed through Bulk Motion Comptonization (BMC). We further argue that the noted lack of coherence between intensity variations of the high-soft-state low and high energy bands is a natural consequence of our model, and that a natural explanation for the observed hard and soft lag phenomenon is offered. In addition, we address some criticisms of the BMC model supporting our claims with observational results.

  18. Delta XTE Spacecraft Solar Panel Deployment, Hangar AO at Cape Canaveral Air Station

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The footage shows technicians in the clean room checking and adjusting the deployment mechanism of the solar panel for XTE spacecraft. Other scenes show several technicians making adjustments to software for deployment of the solar panels.

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

    NASA Technical Reports Server (NTRS)

    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 -

  20. Looking for black-holes in X-ray binaries with XMM-Newton: XTE J1817-330 and XTE J1856+053

    SciTech Connect

    Sala, Gloria; Greiner, Jochen; Primak, Natalia

    2008-10-08

    The X-ray binary XTE J1817-330 was discovered in outburst on 26 January 2006 with RXTE/ASM. One year later, another X-ray transient discovered in 1996, XTE J1856+053, was detected by RXTE during a new outburst on 28 February 2007. We triggered XMM-Newton target of opportunity observationson these two objects to constrain their parameters and search for a stellar black holes. We summarize the properties of these two X-ray transients and show that the soft X-ray spectra indicate indeed the presence of an accreting stellar black hole in each of the two systems.

  1. Discovery and Photometric Observation of the Optical Counterpart of a Possible Galactic Halo X-Ray Transient, XTE J1118+480

    NASA Astrophysics Data System (ADS)

    Uemura, Makoto; Kato, Taichi; Matsumoto, Katsura; Yamaoka, Hitoshi; Takamizawa, Kesao; Sano, Yasuo; Haseda, Katsumi; Cook, Lewis M.; Buczynski, Denis; Masi, Gianluca

    2000-08-01

    We discovered an optical counterpart of about 13 mag of a soft X-ray transient, XTE J1118+480 on 2000 March 30. We performed astrometry and provided an accurate position of R.A. = 11h18m10.85s85, Decl. = +48deg02'12.9{' '}. The outbursting object has been identified with a 18.8 mag star in the USNO catalog. Our pre-discovery data shows another outburst during 2000 January, again coinciding with an outburst detected in X-rays. Through CCD time-series photometry, we found the presence of a periodic variation with an amplitude of 0.055 mag and a period of 0.17078 \\pm 0.00004 d$, which we consider to be a promising candidate of the orbital period. Because of the high galactic latitude and faint quiescence magnitude of 18.8, XTE J1118+480 is possibly the first firmly identified black hole candidate X-ray transient in the galactic halo.

  2. EVIDENCE OF LIGHT-BENDING EFFECTS AND ITS IMPLICATION FOR SPECTRAL STATE TRANSITIONS

    SciTech Connect

    Reis, R. C.; Miller, J. M.; Reynolds, M. T.; Fabian, A. C.; Walton, D. J.; Steiner, J. F.; Cackett, E.

    2013-01-20

    It has long been speculated that the nature of the hard X-ray corona may be an important second driver of black hole state transitions, in addition to the mass accretion rate through the disk. However, a clear physical picture of coronal changes has not yet emerged. We present results from a systematic analysis of Rossi X-Ray Timing Explorer observations of the stellar-mass black hole binary XTE J1650-500. All spectra with significant hard X-ray detections were fit using a self-consistent, relativistically blurred disk reflection model suited to high ionization regimes. Importantly, we find evidence that both the spectral and timing properties of black hole states may be partially driven by the height of the X-ray corona above the disk, and related changes in how gravitational light bending affects the corona-disk interaction. Specifically, the evolution of the power-law, thermal disk, and relativistically convolved reflection components in our spectral analysis indicates that: (1) the disk inner radius remains constant at r {sub in} =1.65 {+-} 0.08 GM/c {sup 2} (consistent with values found for the ISCO of XTE J1650-500 in other works) throughout the transition from the brighter phases of the low-hard state to the intermediate states (both the hard-intermediate and soft-intermediate), through to the soft state and back; (2) the ratio between the observed reflected X-ray flux and power-law continuum (the 'reflection fraction', R) increases sharply at the transition between the hard-intermediate and soft-intermediate states ('ballistic' jets are sometimes launched at this transition); (3) both the frequency and coherence of the high-frequency quasi-periodic oscillations observed in XTE J1650-500 increase with R. We discuss our results in terms of black hole states and the nature of black hole accretion flows across the mass scale.

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

    NASA Astrophysics Data System (ADS)

    Alford, J. A. J.; Halpern, J. P.

    2016-02-01

    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 4.1 × 10-11 to 8.1 × 10-13 erg cm-2 s-1. 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 (NS) 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 NS 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 ≈ 20% between 2008 and 2009 March, the same period during which XTE J1810-197 became radio quiet.

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

    NASA Astrophysics Data System (ADS)

    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.

  5. The Anatomy Of A Magnetar: XMM Monitoring Of Transient AXP XTE J1810-197

    NASA Astrophysics Data System (ADS)

    Gotthelf, Eric V.; Halpern, J. P.; Perna, R.

    2006-09-01

    The transient anomalous X-ray pulsar (TAXP) XTE J1810-197 is a unique object whose remarkable properties offer great promise for deciphering the emission mechanism(s) of magnetars. This 5.54s pulsar was discovered in early 2003 during an outburst that has, as of 2006, faded near to quiescence, based on historic data. TAXP XTE J1810-197 is, most surprisingly, a highly variable radio pulsar with a unusual flat spectrum. This is the first confirmed example of radio flux from an AXP. Herein, we report on our semi-annual XMM monitoring campaign that has followed the pulsar for the last 3 years as its spectrum evolved. Fitting a double blackbody model we find that the component luminosities followed an exponential decay law with κ(BB1) = 870 days and κ(BB2) = 280 days, respectively. The temperatures of these components cooled at a rate of 22% per year from the nearly constant value recorded prior to 2004 March of kT(BB1) = 0.25 keV and kT(BB2) = 0.67 keV, respectively. The latest data show that the luminosity and temperature of the cooler component have effectively returned to their quiescent levels and that its pulsed fraction, which has steadily decreased with time, is now consistent with the previous lack of detected pulsations in quiescence. We use the energy dependence of the fading emission to decouple the pulsed components to solve for the viewing and emitting geometry of XTE J1810-197. Finally, we consider the emission mechanism(s) of XTE J1810-197 in the context of the coronal loop magnetar model of Beloborodov & Thompson (2006). This research is supported by XMM-Newton grant NNG05GJ61G and NASA ADP grant ADP04-0059-0024.

  6. Development of the solar array deployment and drive system for the XTE spacecraft

    NASA Technical Reports Server (NTRS)

    Farley, Rodger; Ngo, Son

    1995-01-01

    The X-ray Timing Explorer (XTE) spacecraft is a NASA science low-earth orbit explorer-class satellite to be launched in 1995, and is an in-house Goddard Space Flight Center (GSFC) project. It has two deployable aluminum honeycomb solar array wings with each wing being articulated by a single axis solar array drive assembly. This paper will address the design, the qualification testing, and the development problems as they surfaced of the Solar Array Deployment and Drive System.

  7. Serendipitous Detections of XTE J1906+09 with the Rossi X-Ray Timing Explorer

    NASA Technical Reports Server (NTRS)

    Wilson, Colleen A.; Finger, Mark H.; Gogus, Ersin; Woods, Peter M.; Kouveliotou, Chryssa

    2002-01-01

    The 89 s X-ray pulsar XTE J1906+09 was discovered during Rossi X-Ray Timing Explorer (RXTE) observations of SGR 1900+14 in 1996. Because of monitoring campaigns of SGR 1900+14, XTE J1906+09 was also monitored regularly in 1996 September, 1998 May-June, 1998 August-1999 July, and 2000 March-2001 January. A search for pulsations resulted in detections of only the two previously reported outbursts in 1996 September and 1998 August-September. Pulsed flux upper limits for the rest of the observations show that XTE J1906+09 is a transient X-ray pulsar and likely has a Be star companion. The RXTE all-sky monitor did not reveal XTE J1906+09. Pulse-timing analysis of the second outburst discovered a sinusoidal signature in the pulse frequencies that is likely produced by an orbital periastron passage. Fits to pulse phases using an orbital model and quadratic phase model have chi(exp 2) minima at orbital periods of 26-30 days for fixed mass functions of 5, 10, 15, and 20 solar masses. The pulse shape showed energy- and intensity-dependent variations. Pulse-phase spectroscopy quantified the energy-dependent variations. The phase-averaged spectrum used the pulse minimum spectrum as the background spectrum to eliminate effects from SGR 1900+14 and the Galactic ridge and was well fitted by an absorbed power law with a high-energy cutoff with column density N(sub H) = 6 +/- 1 x 10(exp 22)/sq cm, a photon index of 1.01 +/- 0.08, cutoff energy E(sub cut) = 11 +/- 1 keV, and e-folding energy E(sub fold) = 19 +/- 4 keV. Estimated 2-10 keV peak fluxes, corrected for contributions from the Galactic ridge and SGR 1900+14, are 6 x l0(exp -12) and 1.1 x 10(exp -10) ergs/sq cm/s for the 1996 and 1998 outbursts, respectively. XTE J1906+09 may be part of an unusual class of Be/X-ray binaries that do not lie on the general spin period versus orbital period correlation with the majority of Be/X-ray binaries.

  8. Serendipitous Detections of XTE J1906+09 with the Rossi X-ray Timing Explorer

    NASA Technical Reports Server (NTRS)

    Wilson, Colleen A.; Finger, Mark H.; Gogus, Ersin; Woods, Peter M.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    In 1996 during Rossi X-ray Timing Explorer (RXTE) observations of SCR 1900+14, the 89-second X-ray pulsar XTE J1906+09 was discovered. As a result of monitoring campaigns of SGR 1900+14, XTE J1906+09 was also monitored regularly in 1996 September, 1998 May-June, 1998 August-1999 July, and 2000 March-2001 January. A frequency grid search of these observations resulted in detections of only the two previously reported outbursts in 1996 September and 1998 August-September. The non-detection of XTE J1906+09 in most observations indicates that it is a transient X-ray pulsar and therefore likely has a Be star companion, Pulse timing analysis of the second outburst revealed a sinusoidal signature in the pulse frequencies that is likely produced by periastron passage in a long period, eccentric, orbit. During the second outburst, the pulse shape changed with increasing intensity, Low intensity pulse profiles from the second outburst are consistent with profiles from the fainter first outburst. Energy dependent pulse shape variations were seen in both outbursts. Pulse phase spectroscopy was used to quantify these variations. The phase averaged spectrum, using the pulse minimum spectrum as the background spectrum to eliminate effects from SGR 1900+14 and the galactic ridge, was well fitted by an absorbed power law with a high energy cutoff with column density N(sub H) = (6 +/- 1) x 10(exp 22) cm(sup -2), photon index = 1.01 +/- 0.08, cutoff energy E(sub cut) = 11 +/- 1 keV, and folding energy E(sub fold) = 19 +/- 4 keV.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Optical re-brightening of the black hole binary XTE J1859+226

    NASA Astrophysics Data System (ADS)

    Corral-Santana, J. M.; Rodríguez-Gil, P.; Hurley, D.; Casares, J.

    2010-09-01

    Observations of the black hole binary XTE J1859+226 revealed an unexpected optical re-brightening. Images were taken with the Nordic Optical Telescope (NOT) using ALFOSC on Jul 13-14, the William Herschel Telescope (WHT) with ACAM on Aug 8 and the Isaac Newton Telescope (INT) with WFC on Aug 19 at the Observatorio del Roque de los Muchachos, La Palma, Spain. The target is found ~1 magnitude brighter than its quiescence level of R=22.48 +- 0.07 as reported in Zurita et al.

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

    NASA Technical Reports Server (NTRS)

    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.

  12. Corrected Name for 5.54 s Pulsar: XTE J1810-197

    NASA Astrophysics Data System (ADS)

    Swank, J. H.; Markwardt, C. B.; Ibrahim, A. I.

    2003-07-01

    In ATEL 167, we reported the position of a new source as R.A. = 18h10.9m, Decl. = -19o42' (equinox 2000.0) , with estimated 99% confidence semi-major axes of 5' in R.A. and 7' in Decl. We designated the new pulsar as XTE J1811-197. The same name appeared in CBET 36. It was brought to our attention by Dr. Marion Schmitz, head of the IAU Working Group on Designations, that the name did not follow the specifications of the IAU, which can be found at: http://cdsweb.u-strasbg.fr/iau-spec.html.

  13. Magnetoreflectivity of Pb{sub 1{minus}x}Eu{sub x}Te epilayers and PbTe/Pb{sub 1{minus}x}Eu{sub x}Te multiple quantum wells

    SciTech Connect

    Yuan, S.; Krenn, H.; Springholz, G.; Ueta, Y.; Bauer, G.; McCann, P.J.

    1997-02-01

    Molecular-beam epitaxy grown n-type Pb{sub 1{minus}x}Eu{sub x}Te epilayers (x{le}0.034) and PbTe/Pb{sub 1{minus}x}Eu{sub x}Te (x{le}0.039) multiple-quantum-well (MQW) samples were studied by magnetoreflectivity in the Faraday configuration (B{parallel}[111]) for magnetic fields up to 6T at 4.2 K. Since the IV-VI lead salt compounds are quite polar semiconductors, resonant electron-longitudinal-optic- (LO-) phonon coupling (Fr{umlt o}hlich coupling) modifies the cyclotron resonance (CR) energies in the Pb{sub 1{minus}x}Eu{sub x}Te single epilayers for the three-dimensional (3D) case. Due to the many-valley band structure {ital two} different Fr{umlt o}hlich coupling constants are relevant. However, the CR energies of quasi-two-dimensional (2D) carriers in PbTe wells [n{sup 2D}=(1.5{minus}3){times}10{sup 11}cm{sup {minus}2}] of PbTe/Pb{sub 1{minus}x}Eu{sub x}Te MQW samples do {ital not} exhibit a significant resonant electron-LO-phonon interaction. This observation is attributed to finite-electron concentration effects, in particular, to a partial filling of the lowest 2D Landau spin level. The static and dynamic screening of the polar interaction are considered as well, but are ruled out as an explanation for the absence of any remarkable polaron correction to the CR energies of electrons in the PbTe quantum wells for the range of carrier concentrations investigated. The magnetoreflectivity spectra of Pb{sub 1{minus}x}Eu{sub x}Te single layers and PbTe/Pb{sub 1{minus}x}Eu{sub x}Te quantum well samples are simulated numerically, using a model for the dielectric response of which also includes the electron-LO-phonon interaction. The transverse and longitudinal masses, and thus also the interband momentum matrix elements are determined for Pb{sub 1{minus}x}Eu{sub x}Te as a function of the composition up to x{lt}0.034. It is found that the transverse mass {ital increases} with Eu content, whereas the longitudinal one nearly stays constant. (Abstract Truncated)

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

    NASA Technical Reports Server (NTRS)

    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.

  15. Optical outburst of the B[e]/X-Ray system CI Cam/XTE J0421+560

    NASA Astrophysics Data System (ADS)

    Wijngaarden, M. J. P.; Gourdji, K.; Oostrum, L. C.; Henrichs, H. F.

    2016-10-01

    We report a very strong optical outburst of the B[e]/transient X-ray system CI Cam/XTE J0421+560. On 2016 Oct 09.064 we measured H alpha at 80 times the continuum flux level, similar to the previous reported outbursts in 1998 (Hynes et al., 2002) and 2005 (Yan et al., 2007).

  16. Doppler tomography of XTE J1118+480 revealing chromospheric emission from the secondary star

    NASA Astrophysics Data System (ADS)

    Zurita, C.; González Hernández, J. I.; Escorza, A.; Casares, J.

    2016-08-01

    Doppler tomography of emission lines in low-mass X-ray binaries allows us to investigate the structure and variability of the accretion discs as well as possible activity arising from the secondary stars. We present Doppler maps of the black hole binary XTE J1118+480 from spectra obtained using OSIRIS@GTC during quiescence on four different nights in 2011 and 2012. Doppler imaging of the Hα line shows, for the first time, a narrow component from the secondary star with observed equivalent widths varying in the range 1.2-2.9 Å but not correlated with the veiling of the accretion disc. The Hα flux of the secondary star is too large to be powered by X-ray irradiation, supporting chromospheric activity, possibly induced by rapid rotation, as the most likely origin of this feature in the black hole X-ray binary XTE J1118+480. In addition, we detect variations in the centroid of the Hα line on nightly basis. These are likely caused by a precessing accretion disc, although with a much lower amplitude (˜50 km s-1) than previously observed.

  17. The Reawakening of the Sleeping X-ray Pulsar XTE J1946+274

    NASA Technical Reports Server (NTRS)

    Mueller, Sebastian; Mueller, Sebastian; Kuechnel, Matthias; Fuerst, Felix; Kreykenbohm, Ingo; Sagredo, Macarena; Obst, Maria; Wilms, Joern; Caballero, Isabel; Potttschmidt, Katja; Ferrigno, Carlo; Rothschild, Richard E.

    2012-01-01

    We report on a series of outbursts of the high mass X-ray binary XTE 11946+274 in 2010/2011 as observed with INTEGRAL, RXTE, and Swift. We discuss possible mechanisms resulting in the extraordinary outburst behavior of this source. The X-ray spectra can be described by standard phenomenological models, enhanced by an absorption feature of unknown origin at about 10 keV and a narrow iron K alpha fluorescence line at 6.4keV, which are variable in flux and pulse phase. We find possible evidence for the presence of a cyclotron resonance scattering feature at about 25 keV at the 93% level. The presence of a strong cyclotron line at 35 keV seen in data from the source's 1998 outburst and confirmed by a reanalysis of these data can be excluded. This result indicates that the cyclotron line feature in XTE 11946+274 is variable between individual outbursts.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Discovery of a Second Millesecond Accreting Pulsar: XTE J1751-305

    NASA Technical Reports Server (NTRS)

    Markwardt, C. B.; Swank, J. H.; Strohmayer, T. E.; intZand, J. J. M.; Marshall, F. E.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We report the discovery by the RXTE PCA of a second transient accreting millisecond pulsar, XTE J1751-305, during regular monitoring observations of the galactic bulge region. The pulsar has a spin frequency of 435 Hz, making it one of the fastest pulsars. The pulsations contain the signature of orbital Doppler modulation, which implies an orbital period of 42 minutes, the shortest orbital period of any known radio or X-ray millisecond pulsar. The mass function, f(sub x) = (1.278 +/- 0.003) x 10 (exp -6) solar mass, yields a minimum mass for the companion of between 0.013 and 0.0017 solar mass depending on the mass of the neutron star. No eclipses were detected. A previous X-ray outburst in June, 1998, was discovered in archival All-Sky Monitor data. Assuming mass transfer in this binary system is driven by gravitational radiation, we constrain the orbital inclination to be in the range 30 deg-85 deg and the companion mass to be 0.013-0.035 solar mass. The companion is most likely a heated helium dwarf. We also present results from the Chandra HRC-S observations which provide the best known position of XTE J1751-305.

  20. Black Hole X Ray Nova Outburst with XTE and HST

    NASA Technical Reports Server (NTRS)

    Patterson, Joseph; Haswell, Carole

    1998-01-01

    We obtained multiwavelength coverage of the soft X-ray transient. GRO J1655-40 during its 1996 outburst, using HST (Hubble Space Telescope), RXTE (Rossi X Ray Timing Explorer), CGRO (Compton Gamma Ray Observatory), and ground-based facilities. This outburst was qualitatively different from other SXT (Soft X Ray Telescope) outbursts and from previous outbursts of this source. The onset of hard X-ray activity occurred very slowly, over several months, and was delayed relative to the soft X-ray rise. During this period, the optical fluxes declined steadily. This apparent anticorrelation is not consistent with with the standard disk instability model of SXT outbursts, nor is it expected if the optical output is dominated by reprocessed X-rays, as in persistent low-mass X-ray binaries. Based on the strength of the 2175-A interstellar absorption feature, we constrain the reddening to be E(B - V) = 1.2 plus or minus 0.1, a result which is consistent with the known properties of the source and with the strength of other interstellar absorption lines. After this dereddening we find that the spectra are dominated by a component peaking in the optical, with the expected v (sup l/3) disk spectrum seen only in the ultraviolet. Bowen fluorescence lines of NIII and OIII are also seen, as well as possible P Cyg profiles in the ultraviolet resonance lines. These features suggest an accretion-disk wind. The X-ray spectra broadly resemble the high/soft state commonly seen in black hole candidates, but evolve through two substates.

  1. CORRELATIONS IN HORIZONTAL BRANCH OSCILLATIONS AND BREAK COMPONENTS IN XTE J1701-462 AND GX 17+2

    SciTech Connect

    Bu, Qing-cui; Chen, Li; Zhang, Liang; Li, Zhao-sheng; Qu, Jin-lu; Belloni, T. M. E-mail: chenli@bnu.edu.cn E-mail: tomaso.belloni@brera.inaf.it

    2015-01-20

    We studied the horizontal branch oscillations (HBO) and the band-limited components observed in the power spectra of the transient neutron star low-mass X-ray binary XTE J1701-462 and the persistent ''Sco-like'' Z source GX 17+2. These two components were studied based on the state-resolved spectra. We found that the frequencies of XTE J1701-462 lie on the known correlations (WK and PBK), showing consistency with other types of X-ray binaries (black holes, atoll sources, and millisecond X-ray pulsars). However, GX 17+2 is shifted from the WK correlation like other typical Z sources. We suggest that the WK/PBK main track forms a boundary that separates persistent sources from transient sources. The characteristic frequencies of break and HBO are independent of accretion rate in both sources, though it depends on spectral models. We also report the energy dependence of the HBO and break frequencies in XTE J1701-462 and how the temporal properties change with spectral state in XTE J1701-462 and GX 17+2. We studied the correlation between rms at the break and the HBO frequency. We suggest that HBO and break components for both sources probably arise from a similar physical mechanism: Comptonization emission from the corona. These two components could be caused by the same kind of oscillation in a corona with uneven density, and they could be generated from different areas of the corona. We further suggest that different proportions of the Comptonization component in the total flux cause the different distribution between GX 17+2 and XTE J1701-462 in the rms{sub break}-rms{sub HBO} diagram.

  2. Tuning the composition of ternary Bi2Se3xTe3(1-x) nanoplates and their Raman scattering investigations

    NASA Astrophysics Data System (ADS)

    Wu, Peng; Chen, Haiping; Yang, Chao; Gan, Wei; Muhammad, Zahir; Song, Li

    2016-07-01

    We present the composition engineering and Raman scattering study of Bi2Se3xTe3(1-x) nanoplates that were synthesized by chemical vapor deposition method using different substrates, including fluorophlogopite mica, SiO2/Si. The characterizations revealed high crystallinity and layered-structure in the ternary Bi2Se3xTe3(1-x) products. Raman spectra of Bi2Se3xTe3(1-x) ranging from 80-200 cm-1 as a function of different Se-doping levels shows that intrinsic Raman peaks of Bi2Se3xTe3(1-x) nanoplates shift to higher frequency as the ratio of doped-Se increasing. The discontinuity of Raman peaks was found and discussed.

  3. Gamma-ray polarization in accreting black holes: the case of XTE J1118+480

    NASA Astrophysics Data System (ADS)

    Vieyro, Florencia; Chaty, Sylvain; Romero, Gustavo E.

    2016-07-01

    Several black hole binaries (BHBs) present persistent soft gamma-ray emission (up to E ˜MeV). Although different models have been proposed to explain the origin of this component (non-thermal corona, relativistic jets), its nature still remains unknown. The detection of strong polarization at high-energies in the well-studied system Cygnus X-1 provides new constraints on the emitting region of the radiation. In this work we study the case of the BHB XTE J1118+480, a transient source that has been observed during two outbursts. In both cases multiwavelenght observations could be obtained because of the privileged location of the source, which implies low interstellar absorption. We apply a non-thermal lepto-hadronic coronal model to reproduce the X/γ-ray emission of this BHB during its outburts, and study the polarization of high-energy radiation expected for future episodes.

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

    SciTech Connect

    Riggio, A.; Burderi, L.; Egron, E.; Di Salvo, T.; D'Ai, A.; Iaria, R.; Robba, N. R.; Papitto, A.; Belloni, T.; Motta, S.; Floris, M.; Testa, V.; Menna, M. T.

    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.

  5. Spectrum of a jet-emitting disc: application to the microquasar XTE J1118+480

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Fu; Xie, Fu-Guo

    2013-10-01

    Under the framework of the magnetized accretion ejection structures, we analyse 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 the 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.

  6. THE MASS OF THE BLACK HOLE IN XTE J1118+480

    SciTech Connect

    Khargharia, Juthika; Froning, Cynthia S.; Robinson, Edward L.; Gelino, Dawn M. E-mail: cynthia.froning@colorado.edu E-mail: dawn@ipac.caltech.edu

    2013-01-01

    We present contemporaneous, broadband, near-infrared spectroscopy (0.9-2.45 {mu}m) and H-band photometry of the black hole X-ray binary, XTE J1118+480. We determined the fractional dilution of the NIR ellipsoidal light curves of the donor star from other emission sources in the system by comparing the absorption features in the spectrum with field stars of known spectral type. We constrained the donor star spectral type to K7 V-M1 V and determined that the donor star contributed 54% {+-} 27% of the H-band flux at the epoch of our observations. This result underscores the conclusion that the donor star cannot be assumed to be the only NIR emission source in quiescent X-ray binaries. The H-band light curve shows a double-humped asymmetric modulation with extra flux at orbital phase 0.75. The light curve was fitted with a donor star model light curve, taking into account a constant second flux component based on the dilution analysis. We also fitted models that included emission from the donor star, a constant component from the accretion disk, and a phase-variable component from the bright spot where the mass accretion stream impacts the disk. These simple models with reasonable estimates for the component physical parameters can fully account for the observed light curve, including the extra emission at phase 0.75. From our fits, we constrained the binary inclination to 68 Degree-Sign {<=} i {<=} 79 Degree-Sign . This leads to a black hole mass of 6.9 M{sub Sun} {<=} M{sub BH} {<=} 8.2 M{sub Sun }. Long-term variations in the NIR light curve shape in XTE J1118+480 are similar to those seen in other X-ray binaries and demonstrate the presence of continued activity and variability in these systems even when in full quiescence.

  7. Measuring Black-Hole Spin and Modeling the Jet Dynamics in Microquasar XTE J1550-564

    NASA Astrophysics Data System (ADS)

    Steiner, James F.; McClintock, J. E.

    2011-05-01

    The microquasar XTE J1550-564 produced the very first X-ray jets to be observed from a black-hole X-ray binary. Chandra imaging data obtained for these jets during 2000-2003 offer a near-unique opportunity to test whether the black hole's spin axis is tilted or aligned with respect to the plane of the binary orbit. To this end, we apply a kinematic relativistic blast-wave model to position measurements of the expanding jet. A comparison of the derived orientation of the jet to the optically measured binary inclination angle has important implications for the measurement of black hole spin. We present our results in the context of ongoing studies of the spins of several black holes, including XTE J1550-564.

  8. Chemical analysis of anodic oxide layers based on Hg/sub 1-x/Cd/sub x/Te

    SciTech Connect

    Korsak, T.E.

    1987-02-01

    The goal of this work is to study the application of the photometric method in analyzing the composition of Hg/sub 1-x/Cd/sub x/Te solid solution anodic oxide with high accuracy and without preliminary separation of the elements. In order to determine cadmium content, a photometric measurement on a complex of this element with xylenol orange was used. Mercury concentration was determined using an extraction photometric method based on benzene extraction of chloride complexes of mercury anions with crystal violet. Tellurium content was determined by extraction with dichloroethane of bromide complexes of tellurium with diantipyrylpropylmethane. The authors synthesized diantipyrylpropylmethane as described. They studied single crystal Hg/sub 1-x/Cd/sub x/Te samples of random orientation with x = 0.2 and n-type conductivity.

  9. Ion-implantation-induced damage and resonant levels in Pb/sub 1-x/Sn/sub x/Te

    SciTech Connect

    Gresslehner, K.H.; Palmetshofer, L.

    1980-09-01

    The dependence of the carrier concentration on the implantation dose and on the temperature was investigated in ion-implanted thin films of Pb/sub 1-x/Sn/sub x/Te (0< or =x<0.1). By assuming a twofold defect level in the conduction band we are able to fit the experimental results. With increasing tin content the energy of the defect level shifts towards the conduction-band edge. By extending the results to SnTe a general model for the understanding of the electrical properties of ion-implanted Pb/sub 1-x/Sn/sub x/Te (0< or =x< or =1) is suggested.

  10. Black Hole Mass and Spin from the 2:3 Twin-peak QPOs in Microquasars

    NASA Astrophysics Data System (ADS)

    Mondal, Soumen

    2010-01-01

    In the Galactic microquasars with double peak kHz quasi-periodic oscillations (QPOs) detected in X-ray fluxes, the ratio of the twin-peak frequencies is exactly, or almost exactly 2:3. This rather strongly supports the fact that they originate a few gravitational radii away from its center due to two modes of accretion disk oscillations. Numerical investigations suggest that post-shock matter, before they settle down in a subsonic branch, execute oscillations in the neighborhood region of "shock transition". This shock may excite QPO mechanism. The radial and vertical epicyclic modes of oscillating matter exactly match with these twin-peak QPOs. In fully general relativistic transonic flows, we investigate that shocks may form very close to the horizon around highly spinning Kerr black holes and appear as extremum in the inviscid flows. The extreme shock location provides upper limit of QPOs and hence fixes "lower cutoff" of the spin. We conclude that the 2:3 ratio exactly occurs for spin parameters a >= 0.87 and almost exactly, for wide range of spin parameter, for example, XTE 1550-564, and GRO 1655-40 a>0.87, GRS 1915+105 a>0.83, XTE J1650-500 a>0.78, and H 1743-322 a>0.68. We also make an effort to measure unknown mass for XTE J1650-500(9.1 ~ 14.1 M sun) and H 1743-322(6.6 ~ 11.3 M sun).

  11. Optical second-harmonic imaging of Pb{sub x}Cd{sub 1-x}Te ternary alloys

    SciTech Connect

    Scheidt, T.; Rohwer, E.G.; Bergmann, H.M. von; Saucedo, E.; Dieguez, E.; Fornaro, L.; Stafast, H.

    2005-05-15

    We employ femtosecond laser pulses (80 fs, 1.59 eV, and 80 MHz) to study the optical second-harmonic (SH) response of Pb{sub x}Cd{sub 1-x}Te ternary alloys (x about 0.2) grown by the vertical Bridgman method. The alloy segregates into a Pb-rich and a Cd-rich phase, the latter dominating the SH response of the ternary alloy by at least two orders of magnitude. Several sample regions show a regular layer-by-layer accommodation of the Pb-rich and Cd-rich phases as seen by a periodic alternation of the alloy's SH response on a {approx}10-{mu}m length scale. Furthermore, we employ polarization-resolved SH imaging as well as SH imaging at different azimuthal angles to obtain spatially resolved mappings of the sample, which are sensitive to the composition as well as the growth orientation of the Pb{sub x}Cd{sub 1-x}Te material system. We observe an azimuthal phase shift of approximately 30 deg. between coherent macroscopic regions (several mm{sup 2}) in the Cd-rich phase of the ternary alloy. We interpret these regions as large area crystalline grains of (111) and (411) crystal orientations and approximately equal composition. Hence, SH imaging is shown to spatially resolve regions of different growth directions within the Pb{sub x}Cd{sub 1-x}Te sample.

  12. Structural and chemical analysis of grain boundaries and tellurium precipitates in commercial Cd{sub 1{minus}x}Zn{sub x}Te

    SciTech Connect

    Heffelfinger, J.R.; Medlin, D.L.; James, R.B.

    1998-06-01

    The structure and chemistry of grain boundaries in commercial Cd{sub 1{minus}x}Zn{sub x}Te, prepared by the high-pressure Bridgman technique, have been analyzed using transmission electron microscopy, scanning electron microscopy, infrared-light microscopy and visible-light microscopy. These analyses show that the grain boundaries inside the Cd{sub 1{minus}x}Zn{sub x}Te materials are decorated with tellurium precipitates. Analysis of a tellurium precipitate at a grain boundary by transmission electron microscopy and selected-area electron diffraction found the precipitate to consist of a single, saucer-shaped grain. Electron diffraction from the precipitate was consistent with the trigonal phase of tellurium (space group P3{sub 1}21), which is the equilibrium phase at room temperature and atmospheric pressure. This precipitate was found to be aligned with one of the adjacent CZT grains such that the tellurium (0{bar 1}11) planes were nearly parallel to the CZT (111) planes. High-resolution transmission electron microscopy of the Te/Cd{sub 1{minus}x}Zn{sub x}Te interface showed no tertiary phase at the interface. The structures of the grain boundaries and the Te/Cd{sub 1{minus}x}Zn{sub x}Te interface are discussed and related to their possible implications on Cd{sub 1{minus}x}Zn{sub x}Te gamma-ray detector performance.

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

    NASA Astrophysics Data System (ADS)

    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

  14. The 2013-2014 Outburst of XTE J1908+094 Observed with Swift and NuSTAR: Spectral Evolution and Black Hole Spin Constraint

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Chen, Li; Qu, Jin-lu; Bu, Qing-cui; Zhang, Wei

    2015-11-01

    We present a spectral study of the black hole candidate XTE J1908+094 during its 2013-2014 outburst. We analyzed 36 Swift/XRT observations together with a NuSTAR observation taken along this period. The outburst evolution is similar to what is previously observed in other black hole transients. The source transited from an initial low/hard state to a high/soft state and then went back to the low/hard state. The low/hard-state spectra are dominated by a hard component, while the high/soft-state spectra are dominated by a soft component. In the high/soft state, we find that the disk bolometric luminosity deviates weakly from the standard {T}{{in}}4 dependence, exhibiting a flatter dependence as {L}{{disk}}\\propto {T}{{in}}2. The radial temperature profile is found to be flatter than that of the standard accretion disk. These results suggest an advection-dominated slim disk. During the NuSTAR observation, the source was in the high/soft state. A flare is seen in the NuSTAR light curves. During the flare, a spectral softening occurs with an increase in power-law flux. We suggest that the flare may be associated with the relativistic jets. A broad Fe Kα line and a disk reflection component are observed in the spectra, providing an opportunity to measure the black hole spin via the Fe-line method. We have fitted the NuSTAR spectra with different relativistically blurred disk reflection models. However, the data do not allow us to constrain the spin of the black hole.

  15. THE CROSS SPECTRAL TIME LAG EVOLUTION ALONG BRANCHES IN XTE J1701-462

    SciTech Connect

    Li Zhaosheng; Chen Li; Bu Qingcui; Wang Dehua; Qu Jinlu E-mail: chenli@bnu.edu.cn

    2013-04-20

    We investigate the cross spectrum of XTE J1701-462 in various types of neutron star low-mass X-ray binary subclasses during its 2006-2007 outburst. We analyze the relation between the time lags and temporal variabilities. We find that the hard time lags accompany horizontal branch oscillations (HBOs) and the soft time lags dominate the noise in the low frequency range 0.1-10 Hz on HB. In the Cyg-like phase, the time lags decrease on the middle normal branch (NB) from HB/NB vertex to NB/FB vertex, whereas the time lags are roughly invariant in the Sco-like source. We discuss the fact that the Compton upscattering by the corona introduces the soft lag in low-frequency noise. We suggest that the variation of the Comptonization component from the disk emission leads to the HBOs' time lag evolutions along the Z tracks. We also report the rms amplitude spectrum and phase lag spectrum for the normal branch oscillation (NBO). A {approx}160 Degree-Sign phase lag is found. We find that the rms amplitudes of both the Cyg-like and the Sco-like NBOs linearly increase with the photon energy in low energy bands, and drop in the highest energy band.

  16. On the Nature of XTE J0421+560/CI Cam

    NASA Technical Reports Server (NTRS)

    Belloni, T.; vandenAncker, M.; Dieters, S.; Fender, R.; Fox, D. W.; Kommers, J. M.; Lewin, W. H. G.; VanParadijs, J.

    1999-01-01

    We present the results of the analysis of RXTE, BATSE and optical/IR data of the 1998 outburst of the x-ray transient system XTE J0421+650. The x-ray outburst shows a very fast decay initial e-folding time approximately 0.5 days, slowing down to about 2.3 days). The X ray spectrum in the 2-25 keV band is thermal, softening considerably during decay. Intrinsic absorption is observed, also strongly variable. A strong iron line at around 6.7 keV is observed. No fast time variability is observed (<0.1 rms in the 1-4906 Hz band at peak). The analysis of optical/IR data suggest that the secondary is a b[e] star and place the system at a distance of about 2 kpc. At this distance the 2-25 keV luminosity is about 5 x 10(exp 37) erg/seconds. We compare the properties of this system with those of the Be/NS LMC transient A 0538-66 and suggest that CI cam is of a similar nature. The presence of strong radio emission during outburst indicates that the compact object could be a black hole.

  17. Evolution of relativistic jets from XTE J1550-564 and the environment of microquasars

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang Nan; Hao, Jing Fang

    2008-10-01

    Two relativistic X-ray jets have been detected with the Chandra X-ray observatory in the black hole X-ray transient XTE J1550-564. We report a full analysis of the evolution of the two jets with a gamma-ray burst external shock model. A plausible scenario suggests a cavity outside the central source and the jets first travelled with constant velocity and then are slowed down by the interactions between the jets and the interstellar medium (ISM). The best fitted radius of the cavity is ~0.36 pc on the eastern side and ~0.46 pc on the western side, and the densities also show asymmetry, of ~0.015 cm-3 on the east to ~0.21 cm-3 on the west. Large scale low density region is also found in another microquasar system, H 1743-322. These results are consistent with previous suggestions that the environment of microquasars should be rather vacuous, compared to the normal Galactic environment. A generic scenario for microquasar jets is proposed, classifying the observed jets into three main categories, with different jet morphologies (and sizes) corresponding to different scales of vacuous environments surrounding them.

  18. Modification of band gap in surface layer in Cd 1-xZn xTe by YAG:Nd +3 laser radiation

    NASA Astrophysics Data System (ADS)

    Medvid, Artur; Fedorenko, Leonid L.; Korbutjak, Dmytro V.; Kryluk, Sergiy G.; Yusupov, Mikola M.; Mychko, Aleksandr

    2007-02-01

    A mechanism of formation of graded band-gap based on Thermogradient Effect (TGE) is proposed in Cd 1-xZn xTe at irradiation by second harmonic of a Q-switched YAG:Nd laser. According to the effect, the interstitial atoms of Cd (Cd i) in Cd 1-xZn xTe move along the temperature gradient while the Cd vacancies (V Cd) and Zn atoms - in the opposite direction, into the bulk of the semiconductor where temperature is lower. Photoluminescence (PL) spectra studied at 5 K show that concentration of Zn atoms increases due to aggregation of VCd with Zn after laser irradiation. Formation of a graded band-gap in Cd 1-xZn xTe crystal at irradiation by second harmonica of YAG:Nd laser by is shown to be possible.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. The Influence of Sublimated Aluminium Films on the Properties of Real Cdx Hg1-xTe Surface

    NASA Astrophysics Data System (ADS)

    Guseinov, Emil; Ismailov, Namýk; Tezer, Ateþ

    1996-05-01

    The electron properties of the Al-Cdx Hg1-x Te interface have been studied using conventional C-V, I-V measurements, spectral dependece of the photoconductivity, capacitor photolocomitive force and the photoelectromagnetic effect. A significant change of the spectral dependence of photoconductivity and the surface lifetime of charge carriers in Cdx Hg1-xTe samples covered by aluminium films has been revealed. The results obtained were interpreted by the influence of space charge region (SCR) on the photoconductivity.

  2. XTE J1752-223: a new RXTE and Swift detected X-ray transient in the galactic center region

    NASA Astrophysics Data System (ADS)

    Markwardt, C. B.; Swank, J. H.; Barthelmy, S. D.; Baumgartner, W. H.; Burrows, D. N.; Evans, P. A.; Holland, S. T.; Hoversten, E. A.; Page, K. L.

    2009-10-01

    On 2009-10-23 at 19:55 UT, RXTE discovered a new source while scanning the galactic bulge region, designated XTE J1752-223. Based on the existing PCA scan data, the best fit position is, R.A. = 268.05(16), Dec. = -22.31(4) (J2000), with estimated 95% uncertainty of the final digits shown in parentheses. The 2-10 keV flux of the source at that time was about 30 mCrab. In the past six months, no source has been detected at that position with 95% upper limit of about 1 mCrab.

  3. Terahertz radiation from Cd{sub x}Hg{sub 1-x}Te photoexcited by femtosecond laser pulses

    SciTech Connect

    Krotkus, A.; Adomavicius, R.; Molis, G.; Urbanowicz, A.; Eusebe, H.

    2004-10-01

    Terahertz radiation from Cd{sub x}Hg{sub 1-x}Te samples excited by femtosecond Ti:sapphire laser pulses were measured by using an ultrafast photoconductive antenna manufactured from low-temperature grown GaAs. Terahertz fields radiated by the samples of all three investigated alloy compositions with x=0, 0.2, and 0.3 were of the same order of magnitude. No azimuthal angle dependence of the radiated signal was detected, which evidences that linear current surge effect is dominating over nonlinear optical rectification.

  4. Implication of the Observable Spectral Cutoff Energy Evolution in XTE J1550-564

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Shaposhnikov, Nikolai

    2010-01-01

    The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational appearances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow examination of the photon upscattering under different accretion regimes. We revisit of RXTE data collected from the black hole X-ray binary XTE J1550-564 during two periods of X-ray activity in 1998 and 2000 focusing on the behavior of the high energy cutoff of the power law part of the spectrum. For the 1998 outburst the Iran- sition from the low-hard state to the intermediate state was accompanied by a gradual decrease in the cutoff energy which then showed a sharp reversal to a clear increasing trend during the further evolution towards the very high and high-soft states. However, the 2000 outburst showed only the decreasing part of this pattern. Notably, the photon indexes corresponding to the cutoff increase for the 1998 event are much higher than the index values reached during the 2000 rise transition. We attribute this difference in the cutoff' energy behav- for to the different partial contributions of the thermal and non-thermal (bulk motion) Comptonization in photon upscattering. Namely, during the 1998 event the higher accretion rate presumably provided more cooling to the Comptonizing media and thus reducing the effectiveness of the thermal upscattering process. Under these conditions the bulk motion takes a leading role in boosting the input soft photons. Monte Carlo simulations of the The physical mechanisms responsible for production of the non-thermal emission in accreting black holes should be imprinted in the observational apperances of the power law tails in the X-ray spectra from these objects. Variety of spectral states observed from galactic black hole binaries by it Rossi X-ray Timing Explorer (RXTE) allow

  5. In-Flight Observations of Long-Term Single-Event Effect (SEE) Performance on X-ray Timing Explorer (XTE) Solid-state Recorders (SSRs)

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Gee, George; LaBel, Kenneth A.; Barth, Janet L.

    2004-01-01

    We present multi-year Single Event Upset (SEU) flight data on Solid State Recorder (SSR) memories for the X-ray Timing Explorer (XTE) NASA mission. Actual SEU rates are compared to the predicted rates based on ground test data and environment models.

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

    SciTech Connect

    Dantas, Noelio Oliveira; Lima Fernandes, Guilherme de; Almeida Silva, Anielle Christine; Baffa, Oswaldo; Gómez, Jorge Antônio

    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.

  7. Influence of soft X-ray of a vacuum spark with laser initiation on the surface properties of solid solutions CdXHg1-XTe

    NASA Astrophysics Data System (ADS)

    Ananyin, O. B.; Bogdanov, G. S.; Vovchenko, E. D.; Gerasimov, I. A.; Melekhov, A. P.; Krapiva, P. S.; Novikov, I. K.; Ramakoti, R. S.; Sredin, V. G.

    2016-09-01

    At a certain form of broadband source soft X-ray spectrum is expected to achieve selective radiation exposure to one of the elements of a multi-component material CdXHg1-XTe. In this case we can talk about a change of the surface properties of the substance as a result of selective absorption of soft X-rays.

  8. Topological crystalline insulator Pb{sub x}Sn{sub 1-x}Te thin films on SrTiO{sub 3} (001) with tunable Fermi levels

    SciTech Connect

    Guo, Hua; Liu, Jun-Wei; Wang, Zhen-Yu; Wu, Rui; Ji, Shuai-Hua; Duan, Wen-Hui; Chen, Xi Xue, Qi-Kun; Yan, Chen-Hui; Zhang, Zhi-Dong; Wang, Li-Li; He, Ke; Ma, Xu-Cun

    2014-05-01

    In this letter, we report a systematic study of topological crystalline insulator Pb{sub x}Sn{sub 1-x}Te (0 < x < 1) thin films grown by molecular beam epitaxy on SrTiO{sub 3}(001). Two domains of Pb{sub x}Sn{sub 1-x}Te 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 Pb{sub x}Sn{sub 1-x}Te 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 Pb{sub x}Sn{sub 1-x}Te thin films.

  9. Ab initio calculations of structural, electronic, optical and thermodynamic properties of alkaline earth tellurides BaxSr1-XTe

    NASA Astrophysics Data System (ADS)

    Bahloul, B.; Bentabet, A.; Amirouche, L.; Bouhadda, Y.; Bounab, S.; Deghfel, B.; Fenineche, N.

    2014-03-01

    Structural, electronic and thermodynamic properties of SrTe and BaTe compounds and their ternary mixed crystals BaxSr1-xTe in the rock-salt structure have been studied with density functional theory (DFT), whereas the optical properties have been obtained by using empirical methods such as the modified Moss relation. The exchange-correlation potential was calculated using the generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) and the local density approximation (LDA) of Teter-Pade (TP). In the present work, we used the virtual-crystal approximation (VCA) to study the effect of composition (x). The calculated lattice parameters at equilibrium volume and the bulk modulus for x=0 and x=1 are in good agreement with the literature data. Furthermore, the BaxSr1-xTe alloys are found to be an indirect band gap semiconductor. In addition, we have also predicted the heat capacities (CV), the entropy(S), the internal energy (U) and the Helmholtz free energy (F) of the parent compounds SrTe and BaTe.

  10. Investigation of InSb-In2XTe (X =Ge & Sn) pseudo binary alloys as potential thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Ponnambalam, Vijayabarathi; Morelli, Donald T.

    2015-03-01

    Crystallizing in the zinc blende structure, InSb is known for promising thermoelectric properties with carrier mobility as high as ~ 104 cm2/V s at 300 K. However, the main drawback is its exceptionally high thermal conductivity ~ 20 W/m K at 300 K. In this regard, pseudo binaries InSb-In2XTe (X =Ge & Sn) hold the promise of offering reduced thermal conductivity while maintaining the other thermoelectric properties intact. A series of InSb-In2XTe type alloys has been synthesized. Thermal and electrical transport properties have been studied, and the results will be discussed with an emphasis on how the thermal conductivity is affected by the concentration of solute atoms. This work was supported as part of the Center for Revolutionary Materials for Solid State Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001054.

  11. Prediction of an arc-tunable Weyl Fermion metallic state in Mo(x)W(1-x)Te2.

    PubMed

    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

    2016-01-01

    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 Mo(x)W(1-x)Te2 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 Mo(x)W(1-x)Te2, where non-saturating magneto-resistance and pressure-driven superconductivity have been observed. PMID:26875819

  12. RXTE and BeppoSAX Observations of the Transient X-ray Pulsar XTE J 18591+083

    NASA Technical Reports Server (NTRS)

    Corbet, R. H. D.; intZand, J. J. M.; Levine, A. M.; Marshall, F. E.

    2008-01-01

    We present observations of the 9.8 s X-ray pulsar XTE J159+083 made with the All-Sky Monitor (ASM) and Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer (RXTE), and the Wide Field Cameras (WFC) on board BeppoSAX. The ASM data cover a 12 year time interval and show that an extended outburst occurred between approximately MJD50, 250, and 50, 460 (1996 June 16 to 1997 January 12). The ASM data excluding this outburst interval suggest a possible 61 day modulation. Eighteen sets of PCA observations were obtained over an approx. 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 non-monotonically 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 an error box which is consistent with a previously determined 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/neutral star binary. The possible 61 day orbital period would be of the expected length for a Be star system with a 9.8 s pulse period.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Type I X-ray Bursts from the Neutron-star Transient XTE J1701-462

    NASA Astrophysics Data System (ADS)

    Lin, Dacheng; Altamirano, Diego; Homan, Jeroen; Remillard, Ronald A.; Wijnands, Rudy; Belloni, Tomaso

    2009-07-01

    The neutron-star X-ray transient XTE J1701-462 was observed for ~3 Ms with RXTE during its 2006-2007 outburst. Here we report on the discovery of three type-I X-ray bursts from XTE J1701-462. They occurred as the source was in transition from the typical Z-source behavior to the typical atoll-source behavior, at ~10% of the Eddington luminosity. The first burst was detected in the Z-source flaring branch (FB); the second in the vertex between the FB and normal branches; and the third in the atoll-source soft state. The detection of the burst in the FB cast doubts on earlier speculations that the FB is due to unstable nuclear burning of accreted matter. The last two of the three bursts show photospheric radius expansion, from which we estimate the distance to the source to be 8.8 kpc with a 15% uncertainty. No significant burst oscillations in the range 30-4000 Hz were found during these three bursts.

  15. Enhancement of the crystalline electric field by the conduction electrons in TmxLa1-xTe

    NASA Astrophysics Data System (ADS)

    Matsumura, T.; McEwen, K. A.; Eccleston, R. S.; Suzuki, T.

    2002-09-01

    The physical properties of TmxLa1-xTe for x=0.05 and 0.5 have been investigated by electrical resistivity, magnetic susceptibility, magnetization, and specific heat measurements and by inelastic neutron scattering. It is shown that the Tm ion experiences a large crystalline electric field (CEF) in a metallic environment at a low concentration of x=0.05. The level scheme for x=0.05 is determined to be Γ7-Γ8(10 meV)-Γ6(17.6 meV) by neutron scattering, which is consistent with the bulk properties. However, this scheme is completely opposite to the one predicted from the point charge model. Furthermore, since the Tm ions in an insulating system of TmxYb1-xTe do not show such a big CEF, the present result indicates that the conduction electrons play an important role in determining the strength of the CEF. The Γ7-->Γ8 excitation is split into some peaks. This is associated with the local structure around the Tm ions: when the number of other Tm ions in the first-nearest-neighbor rare-earth sites increases, the excitation energy decreases. At x=0.5, the CEF excitation disappears and only a broad quasielastic scattering is observed. The excitation spectrum is only reproduced by two Gaussian spectral functions both centered at zero energy.

  16. Reflection Spectroscopy of the Black Hole Binary XTE J1752-223 in the Bright Hard State

    NASA Astrophysics Data System (ADS)

    Garcia, Javier; Steiner, James F.; Grinberg, Victoria; McClintock, Jeffrey E.; Dauser, Thomas; Remillard, Ronald A.

    2016-04-01

    During its rise to maximum in 2009, XTE J1752-223 stalled for a full month in the bright hard state at about 30% of its peak (Eddington) luminosity. Along this extended period, 60 RXTE pointed observations showed the luminosity and hardness ratio of the source to be extraordinarily stable, resulting in a unique data set of exceptional quality. We combined all these 300 ks of RXTE data into a single PCA (3-45 keV) spectrum with 82 million counts and a single HEXTE spectrum (20-250 keV) with 10.4 million counts. Using our calibration tools PCACORR and HEXBCORR, we greatly enhanced the sensitivity of the detectors to faint spectral features, such as the Fe line and edge. Fitting the PCA+HEXTE spectrum using an advanced version of our reflection code, which includes a physical model of Comptonization, we constrained: the spin of the black hole (or alternatively the inner radius of the accretion disk); the inclination of the system; the ionization state and Fe abundance of the disk's atmosphere; and the temperature and optical depth of the corona. We compare these results with similar ones we reported earlier for GX 339-4 in the bright hard state. XTE J1752-223 and GX 339-4 are the first two of 29 black hole binaries we propose to study using recalibrated RXTE archival data and our reflection models.

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

    NASA Astrophysics Data System (ADS)

    Younes, G.; Boirin, L.; Sabra, B.

    2009-08-01

    Context: Studying the spectral changes during the dips exhibited by almost edge-on, low-mass X-ray binaries (LMXBs) is a powerful means of probing the structure of accretion disks. The XMM-Newton, Chandra, or Suzaku discovery of absorption lines from Fe xxv and other highly-ionized species in many dippers has revealed a highly-ionized atmosphere above the disk. A highly (but less strongly) ionized plasma is also present in the vertical structure causing the dips, together with neutral material. Aims: We aim to investigate the spectral changes during the dips of XTE J1710-281, a still poorly studied LMXB known to exhibit bursts, dips, and eclipses. Methods: We analyze the archived XMM-Newton observation of XTE J1710-281 performed in 2004 that covered one orbital period of the system (3.8 h). We modeled the spectral changes between persistent and dips in the framework of the partial covering model and the ionized absorber approach. Results: 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)×1022 cm-2. The spectral changes from persistent to deep-dipping intervals are consistent with the partial covering of the power-law emission. Twenty-six percent of the continuum is covered during shallow dipping, and 78% during deep dipping. The column density decreases from 77_-38+67 × 1022 cm-2 during shallow dipping to (14 ± 2) × 1022 cm-2 during the deep-dipping interval. We do not detect any absorption line from highly ionized species such as Fe xxv. However, the upper-limits we derive on their equivalent width (EW) are not constraining. Despite not detecting any narrow spectral signatures of a warm absorber, we show that the spectral changes are consistent with an increase in column density and a decrease in ionization state of a highly-ionized absorber, associated with an increase in column density of a neutral absorber, in agreement with the

  18. Crystallographic properties of as grown CdxHg1- xTe epitaxial layers deposited by cathodic sputtering

    NASA Astrophysics Data System (ADS)

    Roussille, R.

    Large areas (up to 15 cm 2) CdxHg1- xTe epitaxial layers with Cd composition ( x value) from 0.14 to 0.4 (thickness < 15 μm) have been sputtered on to CdTe substrates with [111] orientations. The layers are grown on substrates heated up to 200°C with a deposition rate of 0.6 μm/h. Crystallographic characterization has been carried out, using different techniques such as: reflection high energy electron diffraction (RHEED), reflection X-ray topography and transmission electron microscopy (TEM). RHEED patterns reveal a good crystallographic quality. X-ray topographies show that the substructure of the layer is very similar to that of the substrate. These results are confirmed by TEM observations.

  19. THE FAST SPIRAL-IN OF THE COMPANION STAR TO THE BLACK HOLE XTE J1118+480

    SciTech Connect

    Gonzalez Hernandez, Jonay I.; Rebolo, Rafael; Casares, Jorge E-mail: rrl@iac.es

    2012-01-10

    We report the detection of an orbital period decay of P-dot =-1.83{+-}0.66 ms yr{sup -1} in the black hole X-ray binary XTE J1118+480. This corresponds to a period change of -0.85 {+-} 0.30 {mu}s per orbital cycle, which is {approx}150 times larger than expected from the emission of gravitational waves. These observations cannot be reproduced by conventional models of magnetic braking even when including significant mass loss from the system. The spiral-in of the star is either driven by magnetic braking under extremely high magnetic fields in the secondary star or by a currently unknown process, which will have an impact on the evolution and lifetime of black hole X-ray binaries.

  20. Ferromagnetism in Ge{sub 1-x}Cr{sub x}Te epilayers grown by molecular beam epitaxy

    SciTech Connect

    Fukuma, Y.; Asada, H.; Taya, T.; Irisa, T.; Koyanagi, T.

    2006-10-09

    IV-VI ferromagnetic semiconductor Ge{sub 1-x}Cr{sub x}Te has been grown on BaF{sub 2} (111) by molecular beam epitaxy. The ferromagnetism was clearly established by direct magnetization and Hall measurements. The experimental correlation between the anomalous Hall resistivity {rho}{sub xy} and the resistivity {rho}{sub xx}, {rho}{sub xy}{proportional_to}{rho}{sub xx}{sup 1.76}, is understood from the semiclassical nature of the charge carrier dynamics, suggesting that the ferromagnetism gives rise to p-d exchange interaction. The Curie temperature increases systematically from the substrate temperature T{sub S} of 300 to 250 to 200 deg. C and with increasing the Cr composition along with each T{sub S}.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. CHARACTERIZING INTERMITTENCY OF 4-Hz QUASI-PERIODIC OSCILLATION IN XTE J1550–564 USING HILBERT–HUANG TRANSFORM

    SciTech Connect

    Su, Yi-Hao; Chou, Yi; Hu, Chin-Ping; Yang, Ting-Chang E-mail: yichou@astro.ncu.edu.tw

    2015-12-10

    We present 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 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. The mean high-amplitude duration is 1.45 s and 90% of the oscillation segments have lifetimes below 3.1 s. The mean low-amplitude duration is 0.42 s and 90% of these segments are shorter than 0.73 s. In addition, these intermittent oscillations exhibit a correlation between the oscillation’s rms amplitude and mean count rate. This correlation could be analogous to the linear rms-flux relation found in the 4-Hz LFQPO through Fourier analysis. We conclude that the LFQPO peak in the power spectrum is broadened owing to intermittent oscillations with varying frequencies, which could be explained by using the Lense–Thirring precession model.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    We present 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 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. The mean high-amplitude duration is 1.45 s and 90% of the oscillation segments have lifetimes below 3.1 s. The mean low-amplitude duration is 0.42 s and 90% of these segments are shorter than 0.73 s. In addition, these intermittent oscillations exhibit a correlation between the oscillation’s rms amplitude and mean count rate. This correlation could be analogous to the linear rms-flux relation found in the 4-Hz LFQPO through Fourier analysis. We conclude that the LFQPO peak in the power spectrum is broadened owing to intermittent oscillations with varying frequencies, which could be explained by using the Lense-Thirring precession model.

  4. AN IMPROVED DYNAMICAL MODEL FOR THE MICROQUASAR XTE J1550-564

    SciTech Connect

    Orosz, Jerome A.; Steiner, James F.; McClintock, Jeffrey E.; Torres, Manuel A. P.; Remillard, Ronald A.; Bailyn, Charles D.; Miller, Jon M. E-mail: jsteiner@cfa.harvard.edu E-mail: mtorres@cfa.harvard.edu E-mail: charles.bailyn@yale.edu

    2011-04-01

    We present an improved dynamical model of the X-ray binary and microquasar XTE J1550-564 based on new moderate-resolution optical spectroscopy and near-infrared photometry obtained with the 6.5 m Magellan Telescopes at Las Campanas Observatory. Twelve spectra of the source were obtained using the Magellan Echellette Spectrograph between 2008 May 6 and August 4. In addition, several hundred images of the field were obtained between 2006 May and 2009 July in the J and K{sub S} filters using the PANIC camera. The agreement between the 2006/2007 and 2008 J and K{sub S} light curves is not perfect, and the differences can plausibly be attributed to a hot spot on the accretion disk during the 2006/2007 observations. By combining our new radial velocity measurements with previous measurements obtained in 2001 May at the 8.2 m Very Large Telescope and with light curves, we find an orbital period of P = 1.5420333 {+-} 0.0000024 days and a radial velocity semiamplitude of K{sub 2} = 363.14 {+-} 5.97 km s{sup -1}, which together imply an optical mass function of f(M) = 7.65 {+-} 0.38 M{sub sun}. We find that the projected rotational velocity of the secondary star is 55 {+-} 5 km s{sup -1}, which implies a very extreme mass ratio of Q {identical_to} M/M{sub 2} {approx} 30. Using a model of a Roche lobe-filling star and an azimuthally symmetric accretion disk, we fit simultaneously optical light curves from 2001, near-infrared light curves from 2008, and all of the radial velocity measurements to derive system parameters. We find an inclination of 74.{sup 0}7 {+-} 3.{sup 0}8 and component masses of M{sub 2} = 0.30 {+-} 0.07 M{sub sun} and M = 9.10 {+-} 0.61 M{sub sun} for the secondary star and black hole, respectively. We note that these results depend on the assumption that in 2008, the disk did not have a hot spot, and that the fraction of light contributed by the accretion disk did not change between the spectroscopic and photometric observations. By considering two

  5. Charge Mediated Reversible Metal-Insulator Transition in Monolayer MoTe2 and WxMo1-xTe2 Alloy.

    PubMed

    Zhang, Chenxi; Kc, Santosh; Nie, Yifan; Liang, Chaoping; Vandenberghe, William G; Longo, Roberto C; Zheng, Yongping; Kong, Fantai; Hong, Suklyun; Wallace, Robert M; Cho, Kyeongjae

    2016-08-23

    Metal-insulator transitions in low-dimensional materials under ambient conditions are rare and worth pursuing due to their intriguing physics and rich device applications. Monolayer MoTe2 and WTe2 are distinguished from other TMDs by the existence of an exceptional semimetallic distorted octahedral structure (T') with a quite small energy difference from the semiconducting H phase. In the process of transition metal alloying, an equal stability point of the H and the T' phase is observed in the formation energy diagram of monolayer WxMo1-xTe2. This thermodynamically driven phase transition enables a controlled synthesis of the desired phase (H or T') of monolayer WxMo1-xTe2 using a growth method such as chemical vapor deposition (CVD) and molecular beam epitaxy (MBE). Furthermore, charge mediation, as a more feasible method, is found to make the T' phase more stable than the H phase and induce a phase transition from the H phase (semiconducting) to the T' phase (semimetallic) in monolayer WxMo1-xTe2 alloy. This suggests that a dynamic metal-insulator phase transition can be induced, which can be exploited for rich phase transition applications in two-dimensional nanoelectronics. PMID:27415610

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

    PubMed

    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. PMID:26524258

  7. Discovery of photon index saturation in the black hole binaries

    NASA Astrophysics Data System (ADS)

    Titarchuk, Lev; Shaposhnikov, Nickolai; Seifina, Elena

    2010-03-01

    We present a study of the correlations between spectral, timing properties and mass accretion rate observed in X-rays from the eight Galactic Black Hole (BH) binaries during the transition between hard and soft states. We analyze all transition episodes from X-ray sources observed with Rossi X-ray Timing Explorer (RXTE). We show that broad-band energy spectra of Galactic sources during all these spectral states can be adequately presented by Bulk Motion Comptonization (BMC) model. We also present observable correlations between the index and the normalization of the disk ``seed'' component. The use of ``seed'' disk normalization, which is presumably proportional to mass accretion rate in the disk, is crucial to establish the index saturation effect during the transition to the soft state. We discovered the photon index saturation of the hard spectral components at values of 2.1-3. We present a physical model which explains the index-seed photon normalization correlations. We argue that the index saturation effect of the hard component (BMC1) is due to the soft photon Comptonization in the converging inflow close to BH. We apply our scaling technique to determine BH masses and distances for Cygnus X-1, GX 339-4, 4U 1543-47, XTE J1550-564, XTE J1650-500, H 1743-322 and XTE J1859-226. Good agreement of our results for sources with known values of BH masses and distance provides an independent verification for our scaling technique.

  8. ACCRETION TORQUES AND MOTION OF THE HOT SPOT ON THE ACCRETING MILLISECOND PULSAR XTE J1807-294

    SciTech Connect

    Patruno, Alessandro; Wijnands, R.; Van der Klis, Michiel; Hartman, Jacob M.; Chakrabarty, Deepto

    2010-07-10

    We present a coherent timing analysis of the 2003 outburst of the accreting millisecond pulsar (AMXP) XTE J1807-294. We find a 95% confidence interval for the pulse frequency derivative of (+0.7, + 4.7) x 10{sup -14} Hz s{sup -1} and (-0.6, + 3.8) x 10{sup -14} Hz s{sup -1} for the fundamental and second harmonics, respectively. The sinusoidal fractional amplitudes of the pulsations are the highest observed among AMXPs and can reach values of up to 27% (2.5-30 keV). The pulse arrival time residuals of the fundamental frequency follow a linear anti-correlation with the fractional amplitudes that suggests hot spot motion both in longitude and latitude over the surface of the neutron star. An anti-correlation between residuals and X-ray flux suggests an influence of the accretion rate on pulse phase and casts doubts on the interpretation of pulse frequency derivatives in terms of changes of spin rates and torques on the neutron star.

  9. Optical and Infrared Observations of the Black Hole X-Ray Binary XTE J1118+480

    NASA Astrophysics Data System (ADS)

    Gelino, D. M.; Balman, S.; Kiziloglu, U.; Yilmaz, A.; Kalemci, E.; Tomsick, J. A.

    2003-12-01

    We present optical and near infrared observations of XTE J1118+480, a black hole X-ray transient. The data were obtained with the Kitt Peak National Observatory 2.1 m telescope and the Tubitak National Observatory 1.5 m Russian-Turkish telescope, and are modeled with the WD98 light curve modeling program to find the inclination of the system, and hence, the mass of the black hole. As the distorted companion orbits the black hole, the observed flux rises and falls in a predictable manner, giving rise to ``ellipsoidal variations.'' By modeling the variations observed during X-ray quiescence, we determine the orbital inclination of the system. Both optical and infrared data are needed to fully account for any source of flux that may contaminate the ellipsoidal variations, as a constant source of light will dilute the variations giving an artificially lower inclination angle and higher black hole mass. Once the inclination is known, it is combined with the observed mass function and mass ratio (q = (M2)/(M_1)) to find the mass of the black hole. This project is partially supported by a Center for Astrophysics and Space Sciences (CASS) Postdoctoral Fellowship.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Constraints on the Emission and Viewing Geometry of the Transient Anomalous X-ray Pulsar XTE J1810-197

    NASA Technical Reports Server (NTRS)

    Perna, Rosalba; Gotthelf, E. V.

    2008-01-01

    The temporal decay of the flux components of the transient anomalous X-ray pulsar XTE J1 810-197 following its 2002 outburst presents a unique opportunity to probe the emission geometry of a magnetar. Toward this goal, we model the magnitude of the pulsar's modulation in narrow spectral bands over time. Following previous work, we assume that the postoutburst flux is produced in two distinct thermal components arising from a hot spot and a warm concentric ring. We include general relativistic effects on the blackbody spectra due to gravitational redshift and light bending near the stellar surface, which strongly depend on radius. This affects the model fits for the temperature and size of the emission regions. For the hot spot, the observed temporal and energy-dependent pulse modulation is found to require an anisotropic, pencil-beamed radiation pattern. We are able to constrain an allowed range for the angles that the line of sight (psi) and the hot spot pole (xi) make with respect to the spin axis. Within errors, this is defined by the locus of points in the xi-psi plane that lie along the line [xi + beta(R)] [psi + [beta(R)] = const, where beta(R) is a function of the radius R of the star. For a canonical value of R = 12 km, the viewing parameters range from psi = xi = 37deg to (psi, xi) = (85deg, 15deg). We discuss our results in the context of magnetar emission models.

  12. The X-Ray Transient XTE J1118+480: Multiwavelength Observations of a Low-State Minioutburst

    NASA Astrophysics Data System (ADS)

    Hynes, R. I.; Mauche, C. W.; Haswell, C. A.; Shrader, C. R.; Cui, W.; Chaty, S.

    2000-08-01

    We present multiwavelength observations of the newly discovered X-ray transient XTE J1118+480 obtained in the rising phase of the 2000 April outburst. This source is located at unusually high Galactic latitude and in a very low absorption line of sight. This made the first Extreme Ultraviolet Explorer (EUVE) spectroscopy of an X-ray transient outburst possible. Together with our Hubble Space Telescope, Rossi X-Ray Timing Explorer, and United Kingdom Infrared Telescope data, this gives unprecedented spectral coverage. We find the source in the low hard state. The flat IR-UV continuum appears to be a combination of optically thick disk emission and possibly synchrotron, while at higher energies (including EUV), a typical low hard state power law is seen. EUVE observations reveal no periodic modulation, suggesting an inclination low enough that no obscuration by the disk rim occurs. We discuss the nature of the source and this outburst and conclude that it may be more akin to minioutbursts seen in GRO J0422+32 than to a normal X-ray transient outburst.

  13. Teaching "Candide": A Debate.

    ERIC Educational Resources Information Center

    Braun, Theodore E. D.; And Others

    1988-01-01

    Two different approaches to teaching Voltaire's "Candide", one deriving meaning from the textual fabric or "inside" of the story and the other focusing on the author's "external" intent in writing the story, are presented and compared. (MSE)

  14. Candidate CDTI procedures study

    NASA Technical Reports Server (NTRS)

    Ace, R. E.

    1981-01-01

    A concept with potential for increasing airspace capacity by involving the pilot in the separation control loop is discussed. Some candidate options are presented. Both enroute and terminal area procedures are considered and, in many cases, a technologically advanced Air Traffic Control structure is assumed. Minimum display characteristics recommended for each of the described procedures are presented. Recommended sequencing of the operational testing of each of the candidate procedures is presented.

  15. Study of band inversion in the PbxSn1-xTe class of topological crystalline insulators using x-ray absorption spectroscopy.

    PubMed

    Mitrofanov, K V; Kolobov, A V; Fons, P; Krbal, M; Tominaga, J; Uruga, T

    2014-11-26

    Pb(x)Sn(1-x)Te and Pb(x)Sn(1-x)Se crystals belong to the class of topological crystalline insulators where topological protection is achieved due to crystal symmetry rather than time-reversal symmetry. In this work, we make use of selection rules in the x-ray absorption process to experimentally detect band inversion along the PbTe(Se)-SnTe(Se) tie-lines. The observed significant change in the ratio of intensities of L1 and L3 transitions along the tie-line demonstrates that x-ray absorption can be a useful tool to study band inversion in topological insulators.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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 RXTE observations (~2.5 Ms) of the source in the Z phase and 159 in the atoll phase (~0.5 Ms). We found, respectively, pairs of kilohertz quasi-periodic oscillations (kHz QPOs) in eight observations during the Z phase and single kHz QPO in six observations during the atoll phase. Using the shift-and-add technique, we identified the QPO in the atoll phase as the lower kHz QPO. 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, two and three 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 five 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 cannot be due to neutron star mass, magnetic field, spin, inclination of the accretion disc, etc. If the QPO frequency is a function of the radius in the accretion disc in which it is produced, our results suggest that in XTE J1701-462 the coherence and rms amplitude are not uniquely related to this radius. Here we argue that this difference is instead due to a change in the properties of the accretion flow around the neutron star. Regardless of the precise mechanism, our result shows that effects other than the geometry of space-time around the neutron star have a

  17. MAXI/GSC detection of renewed X-ray activity of the neutron star X-ray binary XTE J1709-267

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

    We report on a detection of X-ray outburst from XTE J1709-267 triggered by the MAXI/GSC nova alert system at 12:25 on 2016 May 31. The MAXI/GSC 2-6 keV X-ray flux on May 31 is 210 mCrab, which is brighter than the peak flux of the previous outburst in July 2012 (160 mCrab in 2-6 keV; Atel #5319, Asai, K. et al, PASJ 67, 92, 2015).

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

    NASA Astrophysics Data System (ADS)

    Poutanen, Juri; Veledina, Alexandra; Revnivtsev, Mikhail G.

    2014-12-01

    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 time-scales 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 the compact radio jet. The inferred spectral shape and the evolution of the non-thermal component during the outburst, however, are not consistent with the jet origin, but are naturally explained in terms of the hybrid hot flow scenario, where non-thermal electrons emit synchrotron radiation in the OIR band. This implies a close, possibly causal connection between the presence of the hot flow and the compact jet. We find that the non-thermal component is hardening during the hard state at the decaying stage of the outburst, which indicates that the acceleration efficiency is a steep function of radius at low accretion rate.

  19. Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338

    NASA Technical Reports Server (NTRS)

    Watts, Anna L.; Strohmayer, Tod E.; Markwardt, Craig B.

    2005-01-01

    The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we can only rule out the hypothesis that the fractional amplitude remains constant at the l(sigma) level for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small (= 0.1Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.

  20. In-Flight Observations of Long-Term Single Event Effect(SEE)Performance on Orbview-2 and Xray Timing Explorer(XTE)Solid State Recorders (SSR)

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Barth, Janet L.; LaBel, Ken A.; Gee, George; Safren, Harvey

    2003-01-01

    This paper presents Single Event Effect (SEE) in-flight data on Solid State Recorders (SSR) that have been collected over a long period of time for two NASA spacecraft: Orbview-2 and XTE. SEE flight data on solid-state memories give an opportunity to study the behavior in space of SEE sensitive commercial devices. The actual Single Event Upset (SEU) rates can be compared with the calculated rates based on environment models and ground test data. The SEE mitigation schemes can also be evaluated in actual implementation. A significant amount of data has already been published concerning observed SEE effects on memories in space. However, most of the data presented cover either a short period of time or a small number of devices. The data presented here has been collected on a large number of devices during several years. This allows statistically significant information about the effect of space weather fluctuations on SEU rates, and the effectiveness of SEE countermeasures used to be analyzed. Only Orbview-2 data is presented in this summary. XTE data will be included in the final paper.

  1. Erratum: "Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium, the Chandra Grating Spectra of XTE J1817-330" (2013, Apj, 768, 60)

    NASA Technical Reports Server (NTRS)

    Gatuzz, E.; Garcia, J.; Mendoza, C.; Kallman, Timothy R.; Witthoeft, Michael C.; Lohfink, A.; Bautista, M. A.; Palmeri, P.; Quinet, P.

    2013-01-01

    In the published version of this paper, there are some minor inaccuracies in the absorption-line wavelengths listed in Table 4 as a result of a faulty reduction procedure of the Obs6615 spectrum. The shifts have been detected in a comparison with the wavelengths listed for this spectrum in the Chandra Transmission Grating Catalog and Archive (TGCat8). They are due to incorrect centroid positions of the zero-order image in both reductions as determined by the tgdetect utility which, when disentangled, yield the improved line positions of the amended Table 4 given below. It must also be pointed out that other quantitative findings of the original paper: 1. Table 5, p. 9: the column density (NH), ionization parameter, oxygen abundance of the warmabs model and the normalization and photon index of the power-law model; 2. Table 6, p. 9: the hydrogen column density of the warmabs fit; 3. Table 7, p. 9: the present oxygen equivalent widths of XTE J1817-330; and 4. Table 8, p. 10: the present oxygen column densities of XTE J1817-330 derived from both the curve of growth and warmabs model fit have been revised in the new light and are, within the estimated uncertainty ranges, in good accord with the new rendering.

  2. ALA Candidates: Presidential Timbre

    ERIC Educational Resources Information Center

    Berry, John N., III

    2010-01-01

    This article presents an interview with two effective spokespeople, notable school librarian Sara Kelly Johns and retired public library administrator Molly Raphael, who compete to be American Library Association (ALA) president. One of them will be elected president of ALA for a year's term beginning in July 2011. Each candidate comes from a…

  3. Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium: The Chandra Grating Spectra of XTE J1817-330

    NASA Technical Reports Server (NTRS)

    Gatuzz, E.; Garcia, J.; Menodza, C.; Kallman, T. R.; Witthoeft, M.; Lohfink, A.; Bautista, M. A.; Palmeri, P.; Quinet, P.

    2013-01-01

    We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra towards the X-ray low-mass binary XTE J1817-330. The 11-25 A broadband is described with a simple absorption model that takes into account the pileup effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 A) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the XSTAR code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain: a column density of N(sub H) = 1.38 +/- 0.01 x 10(exp 21) cm(exp -2); ionization parameter of log xi = .2.70 +/- 0.023; oxygen abundance of A(sub O) = 0.689(exp +0.015./-0.010); and ionization fractions of O I/O = 0.911, O II/O = 0.077, and O III/O = 0.012 that are in good agreement with previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse and Sauval (1998), a rescaling with the revision by Asplund et al. (2009) yields A(sub O) = 0.952(exp +0.020/-0.013, a value close to solar that reinforces the new standard. We identify several atomic absorption lines.K-alpha , K-beta, and K-gamma in O I and O II; and K-alpha in O III, O VI, and O VII--last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n greater than 2 associated to ISM cold absorption.

  4. Photoionization Modeling of Oxygen K Absorption in the Interstellar Medium:. [The Chandra Grating Spectra of XTE J1817-330

    NASA Technical Reports Server (NTRS)

    Gatuzz, E.; Garcia, J.; Mendoza, C.; Kallman, T. R.; Witthoeft, M.; Lohfink, A.; Bautista, M. A.; Palmeri, P.; Quinet, P.

    2013-01-01

    We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra toward the X-ray low-mass binary XTE J1817-330. The 11-25 Angstrom broadband is described with a simple absorption model that takes into account the pile-up effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 Angstroms) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the xstar code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain a column density of N(sub H) = 1.38 +/- 0.01 × 10(exp 21) cm(exp -2); an ionization parameter of log xi = -2.70 +/- 0.023; an oxygen abundance of A(sub O) = 0.689 (+0.015/-0.010); and ionization fractions of O(sub I)/O = 0.911, O(sub II)/O = 0.077, and O(sub III)/O = 0.012 that are in good agreement with results from previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse & Sauval, a rescaling with the revision by Asplund et al. yields A(sub O) = 0.952(+0.020/-0.013), a value close to solar that reinforces the new standard.We identify several atomic absorption lines-K(alpha), K(beta), and K(gamma) in O(sub I) and O(sub II) and K(alpha) in O(sub III), O(sub VI), and O(sub VII)-the last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n greater than 2 associated with ISM cold absorption.

  5. Evolution of the complicated decaying branch of the very long outburst in XTE J1701-462

    NASA Astrophysics Data System (ADS)

    Šimon, Vojtěch

    2015-05-01

    I analyze the evolution of the features which occurred on the timescale of weeks in the very long (∼600 d) X-ray outburst of the neutron star low-mass X-ray binary XTE J1701-462. I used RXTE/ASM (1.5-12 keV) and Swift/BAT (15-50 keV) observations for a time-series analysis of the long-term variations. I utilized the means (usually one-day) of intensity I to increase the signal-to-noise ratio. I applied weighted wavelet Z-transform to investigate the cyclic modulation of I. Using the combined data from both satellites, I also calculated the hardness ratio HR = I(15-50 keV)/I(1.5-12 keV) and investigated its evolution throughout the outburst. Despite the largely different profiles of the light curves in the ASM and the BAT bands especially in the first fourth of the outburst, the profiles of the measures of their scatter (the σresASM and the σresBAT curves) display mutual similarities. Both the σresASM and σresBAT curves achieved their maxima in the primary peak of the light curve which was present only in the ASM band. The formation of the quasi-periodic variations occurred and their approximate cycle-length PC was decided already in the surrounding of this peak when the bolometric luminosity was close to or even exceeding the Eddington limit. The modulation with PC is present in some time segments only in the ASM band, while the intensity variations are always chaotic in the BAT band. Using the results of spectroscopy of Lin et al., I suggests that only multicolor disk, dominant in the ASM band, was involved in this cycle. The existence of this cycle did not depend on the exact type of the Z, so it was independent of the exact conditions in the inner disk region. The length of PC displayed a large and gradual increase from ∼ 16 to ∼ 26 days with the progress of the outburst. Using models of Foulkes et al., I interpret these variations as a superorbital cycle, caused by tilting and warping of the irradiated disk.

  6. PHOTOIONIZATION MODELING OF OXYGEN K ABSORPTION IN THE INTERSTELLAR MEDIUM: THE CHANDRA GRATING SPECTRA OF XTE J1817-330

    SciTech Connect

    Gatuzz, E.; Mendoza, C.; Garcia, J.; Lohfink, A.; Kallman, T. R.; Witthoeft, M.; Bautista, M. A.; Palmeri, P.; Quinet, P. E-mail: claudio@ivic.gob.ve E-mail: alohfink@astro.umd.edu E-mail: michael.c.witthoeft@nasa.gov E-mail: palmeri@umons.ac.be

    2013-05-01

    We present detailed analyses of oxygen K absorption in the interstellar medium (ISM) using four high-resolution Chandra spectra toward the X-ray low-mass binary XTE J1817-330. The 11-25 A broadband is described with a simple absorption model that takes into account the pile-up effect and results in an estimate of the hydrogen column density. The oxygen K-edge region (21-25 A) is fitted with the physical warmabs model, which is based on a photoionization model grid generated with the XSTAR code with the most up-to-date atomic database. This approach allows a benchmark of the atomic data which involves wavelength shifts of both the K lines and photoionization cross sections in order to fit the observed spectra accurately. As a result we obtain a column density of N{sub H} = 1.38 {+-} 0.01 Multiplication-Sign 10{sup 21} cm{sup -2}; an ionization parameter of log {xi} = -2.70 {+-} 0.023; an oxygen abundance of A{sub O}= 0.689{sup +0.015}{sub -0.010}; and ionization fractions of O I/O = 0.911, O II/O = 0.077, and O III/O = 0.012 that are in good agreement with results from previous studies. Since the oxygen abundance in warmabs is given relative to the solar standard of Grevesse and Sauval, a rescaling with the revision by Asplund et al. yields A{sub O}=0.952{sup +0.020}{sub -0.013}, a value close to solar that reinforces the new standard. We identify several atomic absorption lines-K{alpha}, K{beta}, and K{gamma} in O I and O II and K{alpha} in O III, O VI, and O VII-the last two probably residing in the neighborhood of the source rather than in the ISM. This is the first firm detection of oxygen K resonances with principal quantum numbers n > 2 associated with ISM cold absorption.

  7. Dark matter candidates

    SciTech Connect

    Turner, M.S.

    1989-01-01

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of. Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs.

  8. Influence of samarium on the thermoelectric figure of merit of Sm{sub x}Pb{sub 1-x}Te alloys

    SciTech Connect

    Aliev, F. F. Hasanov, H. A.

    2012-03-15

    The temperature and concentration dependences of the electrical (conductivity {sigma}, the Hall coefficient R), thermoelectric (thermovoltage {alpha}), and thermal (thermal conductivity K{sub tot}) characteristics of Sm{sub x}Pb{sub 1-x}Te alloys (x = 0, 0.02, 0.04, 0.08) are studied in the temperature range 100-500 K. Using the data for {sigma}, {alpha}, and K{sub tot}, the thermoelectric power {alpha}{sup 2}{sigma}, figure of merit Z, and efficiency {delta} are calculated. It is established that at room-temperature {alpha}{sup 2}{sigma} and Z peak at the hole concentration p Almost-Equal-To 1.2 Multiplication-Sign 10{sup 18} cm{sup -3}.

  9. Constraints on braneworld gravity models from a kinematic limit on the age of the black hole XTE J1118+480.

    PubMed

    Psaltis, Dimitrios

    2007-05-01

    In braneworld gravity models with a finite anti-de Sitter space (AdS) curvature in the extra dimension, the AdS/conformal field theory correspondence leads to a prediction for the lifetime of astrophysical black holes that is significantly smaller than the Hubble time, for asymptotic curvatures that are consistent with current experiments. Using the recent measurements of the position, three-dimensional spatial velocity, and mass of the black hole XTE J1118+480, I calculate a lower limit on its kinematic age of > or =11 Myr (95% confidence). This translates into an upper limit for the asymptotic AdS curvature in the extra dimensions of <0.08 mm, which significantly improves the limit obtained by table top experiments of sub mm gravity. PMID:17501556

  10. Spin-glass behavior and anomalous magnetoresistance in ferromagnetic Ge{sub 1-x}Fe{sub x}Te epilayer

    SciTech Connect

    Liu, Jindong; Cheng, Xiaomin Tong, Fei; Miao, Xiangshui

    2014-07-28

    We report that the Ge{sub 1-x}Fe{sub x}Te thin film exhibits spin-glass behavior when the Fe concentration increases to 0.08. A large bifurcation between the zero-field cooling and field cooling temperature-dependent magnetization was observed. The hysteresis loops after zero-field cooling and field cooling show an exchange bias effect. A time-dependent thermoremanent magnetization follows power-law decay, which confirms the existence of spin glass. The anomalous magnetotranport properties present a further evidence for spin-glass behavior and give a freezing temperature T{sub g} ∼ 5 K in the Ge{sub 0.92}Fe{sub 0.08}Te thin film.

  11. Low-temperature anomalies of the photoelectromagnetic effect in p-Cd{sub x}Hg{sub 1-x}Te due to recharging of surface states

    SciTech Connect

    Gassan-zade, S. G. Strikha, M. V.; Shepelsky, G. A.

    2008-04-15

    A number of anomalies inexplicable in the context of available theoretical models are observed in the photoelectromagnetic effect in p-Cd{sub x}Hg{sub 1-x}Te crystals. A general model of the photoelectromagnetic effect in semiconductors with a large ratio between the mobilities of electrons and holes is developed, taking into account the influence of space charge. The model allows the interpretation of all experimentally observed anomalies of the photoelectromagnetic effect, including the double sign inversion in magnetic field. Comparison of the theory with the experiment makes it possible to determine the parameters of the material. It is suggested that the space charge responsible for the anomalies of the photoelectromagnetic effect is associated with a high concentration of specific surface states ({approx}10{sup 13} cm{sup -3}) recharged when trapping nonequilibrium charge carriers.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Identification of the optical counterpart of 1RXS J190141.0+012618 and a search for the optical counterpart of XTE J1901+014

    NASA Astrophysics Data System (ADS)

    Powell, C. R.; Norton, A. J.; Haswell, C. A.; Wolters, S. D.; Green, S. F.; Morales-Rueda, L.; Charles, P. A.; Worters, H.

    2002-05-01

    The RXTE error circle of X-ray transient XTE J1901+014, reported in IAUC #7880, includes the much smaller error circle of ROSAT source 1RXS J190141.0+012618, HRI position 19h01m40.1s, +1 26' 30" (J2000) uncertainty 10" (ATEL #89). We obtained Jacobus Kaptyn Telescope B, V, R, I images of the field on 2002 April 18 04:15 - 04:30, the same filters at the IAC80 Telescope (Instituto de Astrofísica de Canarias, Tenerife) on the same night 04:30 - 04:50, and R on the JKT on 2002 April 28 04:45.

  15. Stabilization of the fermi level by a resonant gallium level in Pb{sub 1-x}Sn{sub x}Te alloys

    SciTech Connect

    Skipetrov, E. P. Zvereva, E. A.; Dmitriev, N. N.; Golubev, A. V.; Slynko, V. E.

    2006-08-15

    Electrical properties of gallium-doped n-Pb{sub 1-x}Sn{sub x}Te alloys (x=0.09-0.21) are studied. Ahomalous temperature dependences of the Hall coefficient which indicate the Fermi level pinning by a resonant gallium level in the conduction band were detected. The dependences of the electron concentration and Fermi energy on the alloy composition and temperature are calculated from experimental data in terms of the two-band Kane dispersion relation. It is shown that the gallium resonant level position relative to the valence band top is almost independent of the matrix composition. The dependence of the thermal coefficient of the resonant level shift with respect to the midgap on the alloy composition is obtained.

  16. Phase separation and exchange biasing in the ferromagnetic IV-VI semiconductor Ge{sub 1-x}Mn{sub x}Te

    SciTech Connect

    Lechner, R. T.; Springholz, G.; Hassan, M.; Groiss, H.; Kirchschlager, R.; Stangl, J.; Hrauda, N.; Bauer, G.

    2010-07-12

    Ferromagnetic Ge{sub 1-x}Mn{sub x}Te grown by molecular beam epitaxy with Mn content of x{sub Mn}approx =0.5 is shown to exhibit a strong tendency for phase separation. At higher growth temperatures apart from the cubic Ge{sub 0.5}Mn{sub 0.5}Te, a hexagonal MnTe and a rhombohedral distorted Ge{sub 0.83}Mn{sub 0.17}Te phase is formed. This coexistence of antiferromagnetic MnTe and ferromagnetic Ge{sub 0.5}Mn{sub 0.5}Te results in magnetic exchange-bias effects.

  17. Constraints on braneworld gravity models from a kinematic limit on the age of the black hole XTE J1118+480.

    PubMed

    Psaltis, Dimitrios

    2007-05-01

    In braneworld gravity models with a finite anti-de Sitter space (AdS) curvature in the extra dimension, the AdS/conformal field theory correspondence leads to a prediction for the lifetime of astrophysical black holes that is significantly smaller than the Hubble time, for asymptotic curvatures that are consistent with current experiments. Using the recent measurements of the position, three-dimensional spatial velocity, and mass of the black hole XTE J1118+480, I calculate a lower limit on its kinematic age of > or =11 Myr (95% confidence). This translates into an upper limit for the asymptotic AdS curvature in the extra dimensions of <0.08 mm, which significantly improves the limit obtained by table top experiments of sub mm gravity.

  18. A SPECTRAL STUDY OF THE RAPID TRANSITIONS OF TYPE-B QUASI-PERIODIC OSCILLATIONS IN THE BLACK HOLE TRANSIENT XTE J1859+226

    SciTech Connect

    Sriram, K.; Choi, C. S.; Rao, A. R.

    2013-09-20

    The fast transitions of type-B and type-A quasi-periodic oscillations (QPOs) are rarely found, and they are observed at the peak of the outburst in black hole transient (BHT) sources. The associated spectral variations during such events are crucial to understand the origin and location of such QPOs in the accretion disk. During the 1999 outburst of XTE J1859+226, on four occasions a rapid transition of type-B/A QPOs was noted. We performed broadband spectral analysis on these four observations to unveil the responsible spectral parameter causing the rapid transitions. After invoking simple spectral models, it was observed that disk parameters were consistently varying along with disk and power-law fluxes, and almost no change was noted in the power-law index parameter. Though using a complex physical model showed consistent results, the spectral parameter variations across the transitions were not significant. It was observed that the type-B QPO was always associated with an inner disk front which is closer to the BH. In one observation, a type-A QPO appeared as the source count rate suddenly dropped, and the power-law index as well as disk normalization parameter considerably changed during this transition. The spectral changes in this particular observation were similar to the changes observed in XTE J1817-330, indicating a common underlying mechanism. We have also examined a similar observation of BHT source GX 339-4, where a sudden transition of a type-A/B QPO was noted. Similar spectral study again revealed that the disk parameters were changing. We discuss the results in the framework of a truncated disk model and conclude that the movement of the coupled inner disk-corona region is responsible for such rapid transitions of type-B QPOs.

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

    SciTech Connect

    Marcu-Cheatham, Diana M.; Pottschmidt, Katja; Kühnel, Matthias; Müller, Sebastian; Falkner, Sebastian; Kreykenbohm, Ingo; Caballero, Isabel; Jenke, Peter J.; Wilson-Hodge, Colleen A.; Fürst, Felix; Grinberg, Victoria; Hemphill, Paul B.; Rothschild, Richard E.; Klochkov, Dmitry; Terada, Yukikatsu; 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.

  20. Fast orbital decays of black hole X-ray binaries: XTE J1118+480 and A0620-00★

    NASA Astrophysics Data System (ADS)

    González Hernández, J. I.; Rebolo, R.; Casares, J.

    2014-02-01

    We present new 10.4 m-GTC/OSIRIS spectroscopic observations of the black hole X-ray binary XTE J1118+480 that confirm the orbital period decay at dot{P}=-1.90± 0.57 ms yr-1. This corresponds to a period change of -0.88 ± 0.27 μs per orbital cycle. We have also collected observations of the black hole X-ray binary A0620-00 to derive an orbital period derivative of dot{P}=-0.60± 0.08 ms yr-1 (-0.53 ± 0.07 μs/cycle). Angular momentum losses due to gravitational radiation are unable to explain these large orbital decays in these two short-period black hole binaries. The orbital period decay measured in A0620-00 is very marginally consistent with the predictions of conventional models including magnetic braking, although significant mass-loss (dot{M}_BH / dot{M}_2 ≤ 20 per cent) from the system is required. The fast spiral-in of the star in XTE J1118+480, however, does not fit any standard model and may be driven by magnetic braking under extremely high magnetic fields and/or may require an unknown process or non-standard theories of gravity. This result may suggest an evolutionary sequence in which the orbital period decay begins to speed up as the orbital period decreases. This scenario may have an impact on the evolution and lifetime of black hole X-ray binaries.

  1. The Internal-Candidate Syndrome

    ERIC Educational Resources Information Center

    Barden, Dennis M.

    2008-01-01

    In this article, the author explains the complications involved when an internal candidate is included in an open search for a leadership position in an academic institution. Internal-candidate syndrome is a dilemma faced by institutions when they have to choose between an internal candidate and an external one. There are two reasons why…

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

    NASA Technical Reports Server (NTRS)

    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.

  3. ON THE NATURE OF QUASI-PERIODIC OSCILLATION PHASE LAGS IN BLACK HOLE CANDIDATES

    SciTech Connect

    Shaposhnikov, Nikolai E-mail: lev@milkyway.gsfc.nasa.gov

    2012-06-20

    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 (BHs). 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 provide feedback on the emerging spectrum. We demonstrate that the QPO waveform is presented by the product of a perturbation and time-delayed response factors, where the response is energy dependent. The essential property of this effect is its nonlinear 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 signals in different energy bands. We apply our model to QPOs observed by the 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 on the nature of the power-law spectral component and its variability.

  4. Candidate Assembly Statistical Evaluation

    1998-07-15

    The Savannah River Site (SRS) receives aluminum clad spent Material Test Reactor (MTR) fuel from all over the world for storage and eventual reprocessing. There are hundreds of different kinds of MTR fuels and these fuels will continue to be received at SRS for approximately ten more years. SRS''s current criticality evaluation methodology requires the modeling of all MTR fuels utilizing Monte Carlo codes, which is extremely time consuming and resource intensive. Now that amore » significant number of MTR calculations have been conducted it is feasible to consider building statistical models that will provide reasonable estimations of MTR behavior. These statistical models can be incorporated into a standardized model homogenization spreadsheet package to provide analysts with a means of performing routine MTR fuel analyses with a minimal commitment of time and resources. This became the purpose for development of the Candidate Assembly Statistical Evaluation (CASE) program at SRS.« less

  5. 2009 Elections: The Candidates Statements

    ERIC Educational Resources Information Center

    TechTrends: Linking Research and Practice to Improve Learning, 2009

    2009-01-01

    This article presents the candidates for the 2009 Association for Educational Communications and Technology (AECT) election and their statements. The candidates are: (1) Andy Gibbons (President-Elect); (2) Barbara B. Lockee (President-Elect); (3) Mary Jean Bishop (At-Large Representative); and (4) Deepak Subramony (At-Large Representative). In…

  6. Black holes in GRBs, Binary X-ray sources and Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Ruffini, Remo; Patricelli, Barbara; Grazia Bernardini, Maria; Bianco, Carlo Luciano; Caito, Letizia; de Barros, Gustavo; Izzo, Luca

    Gamma Ray Bursts are possibly the most important tools to study the Physics of Black Holes (BHs), evidencing instantaneous BH formation occurring at the highest redshifts. Such pro-cesses of BH formation with distinctive processes of electron-positron pair creation by vacuum polarization are expected to be different from the ones observed in nearby binary X-ray sources (Cygnus X-1, GX 339-4, 4U 1543-47, XTE J1550-564, XTE J1650-500, H 1743-322 and XTE J1859-226). These last ones should in fact originate from precursors activity acting on much longer time scales, due to accretion mechanisms. We have studied high redshift GRB sources within the fireshell model to infer some of the properties of the BHs from which they originate. Here we present, as an example, the analysis of GRB 050904, characterized by a redshift z=6.3 and an isotropic energy release of Eiso = 1.04x1054 ergs, and of GRB090423, characterized by z = 8.1 and Eiso = 3.4x1053 ergs.We have searched for low redshift GRB sources having similar properties: same energetics, similar light curve structure, intense optical emission. The "twin sources" of these two bursts 0.937) and GRB090618 (z = 0.54) respectively. For both pairs of GRBs the numerical simulations that best repr positron plasma originating the GRB, as well as the same comoving spectral energy distribution. However, we h ncbm > .This could indicate that the two sources of each pair have a similar baryon ic progenitor, but occurred in d 109 sola rmasses. A viable approach based on the Dark Matter component versus the baryon ic component are being

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

    NASA Astrophysics Data System (ADS)

    Gotthelf, E. V.; Halpern, J. P.; Buxton, M.; Bailyn, C.

    2004-04-01

    We report X-ray imaging, timing, and spectral studies of XTE J1810-197, a 5.54 s pulsar discovered by Ibrahim and coworkers in recent Rossi X-Ray Timing Explorer (RXTE) observations. In a set of short exposures with the High Resolution Camera on board the Chandra X-Ray Observatory, we detect a strongly modulated signal (55%+/-4% pulsed fraction) with the expected period located at (J2000) 18h09m51s08, -19deg43'51.7", with a uncertainty radius of 0.6" (90% confidence level). 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 parameters kT=0.67+/-0.01 keV, Γ=3.7+/-0.2, NH=(1.05+/-0.05)×1022 cm-2, and FX(0.5-10keV)=3.98×10-11 ergs cm-2 s-1. Alternatively, a two-temperature blackbody fit is just as acceptable. The location of CXOU J180951.0-194351 is consistent with a point source seen in archival Einstein, ROSAT, and ASCA images, when its flux was nearly 2 orders of magnitude 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-Newton timing data, we place an upper limit of 0.03 lt-s on any orbital motion in the period range 10 minutes-8 hr. Optical and infrared images obtained on the SMARTS 1.3 m telescope at the Cerro Tololo Inter-American Observatory (CTIO) show no object in the Chandra error circle to limits V=22.5, I=21.3, J=18.9, and K=17.5. Together, these results argue that CXOU J180951.0-194351 is an isolated neutron star, one most similar to the transient AXP AX J1844.8-0256. Continuing study of XTE J1810-197 in various states of luminosity is important for understanding and possibly unifying a growing class of isolated, young neutron stars that are not powered by rotation.

  8. Material inhomogeneities in Cd{sub 1-x}Zn{sub x}Te and their effects on large volume gamma-ray detectors

    SciTech Connect

    Scyoc, J.M. van; Lund, J.C.; Morse, D.H.

    1996-08-01

    Cadmium zinc telluride (Cd{sub 1-x}Zn{sub x}Te or CZT) has shown great promise as a material for room temperature x-ray and gamma-ray detectors. There has been a push for the development of CZT detectors with a volume greater than 1 cm{sup 3}. However, nonuniformities in the material over this scale degrade the performance of the detectors. Variations in the zinc fraction, and thus the bandgap, and changes in the impurity distributions, both of which arise from the selective segregation of elements during crystal growth, result in spectral distortions. In this work, several materials characterization techniques were combined with detector evaluations to determine the materials properties limiting detector performance. Materials measurements were performed on detectors found to have differing performance. Measurements conducted include infrared transmission, particle induced x-ray emission, photoluminescence, and triaxial x-ray diffraction. To varying degrees, these measurements reveal that `poor-performance` detectors exhibit higher nonuniformities than `spectrometer-grade` detectors. This is reasonable, as regions of CZT material with different properties will give different localized spectral responses, which combine to result in a degraded spectrum for the total device. 7 refs., 6 figs.

  9. Growth of ferromagnetic semiconductor Ge{sub 1-x}Mn{sub x}Te films on BaF{sub 2} (111) by ionized cluster beam deposition

    SciTech Connect

    Fukuma, Y.; Arifuku, M.; Asada, H.; Koyanagi, T.

    2005-04-01

    IV-VI ferromagnetic semiconductor Ge{sub 1-x}Mn{sub x}Te (x{approx_equal}0.4) films were grown on BaF{sub 2} (111) substrates by an ionized cluster beam method. In neutral cluster beam deposition, Ge{sub 0.64}Mn{sub 0.36}Te films grown at substrate temperatures in the range from 250 to 300 deg. C show an epitaxial relationship Ge{sub 0.64}Mn{sub 0.36}Te/GeTe(111)parallel BaF{sub 2}(111). The crystallinity of the Ge{sub 0.64}Mn{sub 0.36}Te layer is improved with increasing substrate temperature. Further improvements of the crystal properties such as the crystallinity and the surface smoothness are accomplished by the proper acceleration of the ionized GeTe cluster, although the acceleration of the ionized MnTe cluster hardly gives rise to any noticeable improvement of the crystalline quality. The crystalline quality significantly affects the ferromagnetism: the enhancement of the spontaneous magnetization and the decrease of the coercive field are observed for the film grown using the ionized GeTe cluster at the acceleration voltage of 1 kV due to the decreases of magnetic disorder caused by inhomogeneities in Mn distribution and pinning sites of domain-wall motion.

  10. ON THE NATURE OF THE FIRST TRANSIENT Z SOURCE XTE J1701-462: ITS ACCRETION DISK STRUCTURE, NEUTRON STAR MAGNETIC FIELD STRENGTH, AND HARD TAIL

    SciTech Connect

    Ding, G. Q.; Wang, N.; Yan, S. P.; Zhang, S. N.; Qu, J. L. E-mail: dinggq@gmail.com

    2011-08-15

    Using data from the Rossi X-Ray Timing Explorer, we investigate the spectral evolution along a 'Z' track and a '{nu}' 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{sub in}{proportional_to}M-dot{sup 2/7}{sub disk}, for a radiation-pressure-dominated accretion disk interacting with the magnetosphere of a neutron star (NS). The changes in the disk mass accretion rate M-dot{sub disk} are responsible for the evolution of the 'Z' or '{nu}' track. 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 {approx}(1-3) x 10{sup 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 origins of the hard tail.

  11. The use of pulse processing techniques to improve the performance of Cd{sub 1{minus}x}Zn{sub x}Te gamma-ray spectrometers

    SciTech Connect

    Lund, J.C.; Olsen, R.; Van Scyoc, J.M.; James, R.B.

    1996-06-01

    Cd{sub 1{minus}x}Zn{sub x}Te (CZT) has recently shown great promise for use as a room temperature gamma-ray detector material. The availability of large volume (>1 cm{sup 3}) high resistivity CZT crystals has allowed the demonstration of detectors much larger than can be built with the similar material CdTe. However, CZT--like many other room-temperature materials--suffers from the poor transport properties of holes. The poor hole drift properties of CZT cause the characteristic hole tailing in gamma-ray pulse height spectra. The authors have applied pulse processing methods to reduce the hole tailing effects and improve the energy resolution of CZT detectors. They have used two signal processing methods to reduce hole tailing in CZT detectors: digital rise-time compensation and dual time-constant sampling. They discuss the implementation of these techniques, demonstrate results obtained in the laboratory, and compare the performance obtained with other detector systems.

  12. Dependence of the electrical parameters of MBE-grown Cd{sub x}Hg{sub 1} {sub -} {sub x}Te films on the level of doping with indium

    SciTech Connect

    Varavin, V. S. Dvoretskii, S. A.; Ikusov, D. G.; Mikhailov, N. N.; Sidorov, Yu. G.; Sidorov, G. Yu.; Yakushev, M. V.

    2008-06-15

    Dependences of the minority-carrier lifetime and electron mobility in Cd{sub x}Hg{sub 1-x}Te films on their indium-doping level are studied. Films with x {approx} 0.22 grown by molecular-beam epitaxy on GaAs substrates were in situ doped with indium across their entire thickness. The temperature dependences of the lifetime were studied in the temperature range 77-300 K. The decrease in the lifetime, observed as the doping level increases, is governed by the mechanism of Auger recombination. As the doping level becomes higher, the mobility decreases in qualitative agreement with theoretical calculations.

  13. 76 FR 4896 - Call for Candidates

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  14. Material inhomogeneities in Cd{sub 1{minus}x}Zn{sub x}Te and their effects on large volume gamma-ray detectors

    SciTech Connect

    Scyoc, J.M. Van; Lund, J.C.; Morse, D.H.

    1997-09-01

    Cadmium zinc telluride (Cd{sub 1{minus}x}Zn{sub x}Te or CZT) has shown great promise as a material for room-temperature x-ray and gamma-ray detectors. In particular, polycrystalline material grown by the High Pressure Bridgman method with nominal Zn fraction (x) from 0.1 to 0.2 has been used to fabricate high resolution gamma-ray spectrometers with resolution approaching that of cooled high-purity Ge. For increased sensitivity, large areas (> 1 cm{sup 2}) are required, and for good sensitivity to high energy gamma photons, thick detectors (on the order of 1 cm) are required. Thus there has been a push for the development of CZT detectors with a volume greater than 1 cm{sup 3}. However, nonuniformities in the material over this scale degrade the performance of the detectors. Variations in the zinc fraction, and thus the bandgap, and changes in the impurity distributions, both of which arise from the selective segregation of elements during crystal growth, result in spectral distortions. In this work several materials characterization techniques were combined with detector evaluations to determine the materials properties limiting detector performance. Materials measurements were performed on detectors found to have differing performance. Measurements conducted include infrared transmission (IR), particle induced x-ray emission (PIXE), photoluminescence (PL), and triaxial x-ray diffraction (TAXRD). To varying degrees, these measurements reveal that poor-performance detectors exhibit higher nonuniformities than spectrometer-grade detectors. This is reasonable, as regions of CZT material with different properties will give different localized spectral responses, which combine to result in a degraded spectrum for the total device.

  15. The Rapid X-Ray Variability of V4641 Sagittarii (SAX J1819.3-2525 = XTE J1819-254).

    PubMed

    Wijnands; van Der Klis M

    2000-01-10

    We report on the rapid X-ray variability of the variable star and X-ray transient V4641 Sagittarii (SAX J1819.3-2525 = XTE J1819-254) as observed on 1999 September 15 by the proportional counter array (PCA) on board the Rossi X-Ray Timing Explorer. During the first approximately 900 s of the first PCA observation, V4641 Sgr showed very strong X-ray fluctuations by a factor of 4 on timescales of seconds to about 500 on timescales of minutes. The spectrum of the source during this flaring episode became harder when the count rate decreased. After this flaring episode, V4641 Sgr entered a quiescent state in which it remained for the rest of this and subsequent PCA observations. The X-ray spectrum was considerably softer in this quiescent state than during the flaring episode. The intrinsic X-ray luminosity (during both the flaring episode and the quiescent state) and the rapid X-ray variability do not strongly constrain the nature of the compact object (neutron star or black hole) in the system, although a black hole seems to be more likely. The very short duration of the bright X-ray phase of V4641 Sgr and its likely close proximity suggest that many similar objects could be present in our Galaxy, most of which are not noticed when they are in outburst because of the short duration of these outbursts. A considerable number of the black holes present in our Galaxy might be contained in systems similar to V4641 Sgr. PMID:10600626

  16. XTE J1701-462 AND ITS IMPLICATIONS FOR THE NATURE OF SUBCLASSES IN LOW-MAGNETIC-FIELD NEUTRON STAR LOW-MASS X-RAY BINARIES

    SciTech Connect

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

    2010-08-10

    We report on an analysis of Rossi X-Ray Timing Explorer 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 (CD) and hardness-intensity diagrams (HID), but they are accompanied by changes in the kHz quasi-periodic oscillations, broadband variability, burst behavior, and/or X-ray spectra. We find that for most of the outburst the low-energy X-ray flux is a good parameter to track the gradual evolution of the tracks in CD and HID, 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 that during the transition from Z to atoll, characteristic behavior known as the atoll upper banana can equivalently be described as the final stage of a weakening Z source flaring branch, thereby blurring the line between the two subclasses. Our findings strongly suggest that the wide variety in behavior observed in NS-LXMBs with different luminosities can be linked through changes in a single variable parameter, namely the mass accretion rate, without the need for additional differences in the neutron star parameters or viewing angle. We briefly discuss the implications of our findings for the spectral changes observed in NS-LMXBs and suggest that, contrary to what is often assumed, the position along the color-color tracks of Z sources is not determined by the instantaneous mass accretion rate.

  17. Modeling of electron energy spectra and mobilities in semi-metallic Hg{sub 1−x}Cd{sub x}Te quantum wells

    SciTech Connect

    Melezhik, E. O. Gumenjuk-Sichevska, J. V.; Sizov, F. F.

    2015-11-21

    Electron mobility, energy spectra, and intrinsic carrier concentrations in the n-type Hg{sub 0.32}Cd{sub 0.68}Te/Hg{sub 1−x}Cd{sub x}Te/Hg{sub 0.32}Cd{sub 0.68}Te quantum well (QW) in semi-metallic state are numerically modeled. Energy spectra and wave functions were calculated in the framework of the 8-band k-p Hamiltonian. In our model, electron scattering on longitudinal optical phonons, charged impurities, and holes has been taken into account, and the mobility has been calculated by an iterative solution of the Boltzmann transport equation. Our results show that the increase of the electron concentration in the well enhances the screening of the 2D electron gas, decreases the hole concentration, and can ultimately lead to a high electron mobility at liquid nitrogen temperatures. The increase of the electron concentration in the QW could be achieved in situ by delta-doping of barriers or by applying the top-gate potential. Our modeling has shown that for low molar composition x the concentration of holes in the well is high in a wide range of electron concentrations; in this case, the purity of samples does not significantly influence the electron mobility. These results are important in the context of establishing optimal parameters for the fabrication of high-mobility Hg{sub 1−x}Cd{sub x}Te quantum wells able to operate at liquid nitrogen temperature and thus suitable for applications in terahertz detectors.

  18. SAO RAS SN candidates classifications

    NASA Astrophysics Data System (ADS)

    Fatkhullin, T. A.; Moskvitin, A. S.

    2016-08-01

    We observed SN candidates (AT 2016eow, AT 2016enu and AT 2016enf) with the BTA/Scorpio-I on August, 4. Direct images in the R band and long-slit spectra in the range of 3600-7600AA (resolution FWHM = 10A) were obtained.

  19. Candidate Exercise Technologies and Prescriptions

    NASA Technical Reports Server (NTRS)

    Loerch, Linda H.

    2010-01-01

    This slide presentation reviews potential exercise technologies to counter the effects of space flight. It includes a overview of the exercise countermeasures project, a review of some of the candidate exercise technologies being considered and a few of the analog exercise hardware devices, and a review of new studies that are designed to optimize the current and future exercise protocols.

  20. Candidate gene prioritization with Endeavour

    PubMed Central

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

    2016-01-01

    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/. PMID:27131783

  1. Candidate cave entrances on Mars

    USGS Publications Warehouse

    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.

  2. Candidate gene prioritization with Endeavour.

    PubMed

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

    2016-07-01

    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/.

  3. Empathy Development in Teacher Candidates

    ERIC Educational Resources Information Center

    Boyer, Wanda

    2010-01-01

    Using a grounded theory research design, the author examined 180 reflective essays of teacher candidates who participated in a "Learning Process Project," in which they were asked to synthesize and document their discoveries about the learning process over the course of a completely new learning experience as naive learners. This study explored…

  4. Interviewing Teacher-Librarian Candidates

    ERIC Educational Resources Information Center

    Yucht, Alice

    2004-01-01

    When recently asked by an administrator for some realistic questions and "recommended" responses to expect while interviewing candidates for school library positions, the author grouped the questions into three categories: library management, information skills and teaching skills. In this article are the questions she suggested, along with topics…

  5. Metal Nitrides Grown from Ca/Li Flux: Ca6Te3N2 and New Nitridoferrate(I) Ca6(LixFe1-x)Te2N3.

    PubMed

    Dickman, Matthew J; Latturner, Susan E

    2016-08-24

    Two new tellurium-containing nitrides were grown from reactions in molten calcium and lithium. The compound Ca6Te3N2 crystallizes in space group R3̅c (a = 12.000(3)Å, c = 13.147(4)Å; Z = 6); its structure is an anti-type of rinneite (K3NaFeCl6) and 2H perovskite related oxides such as Sr3Co2O6. The compound Ca6(LixFe1-x)Te2N3 where x ≈ 0.48 forms in space group P42/m (a = 8.718(3)Å, c = 6.719(2)Å; Z = 2) with a new stuffed anti-type variant of the Tl3BiCl6 structure. Band structure calculations and easily observable red/green dichroic behavior indicate that Ca6Te3N2 is a highly anisotropic direct band gap semiconductor (Eg = 2.5 eV). Ca6(LixFe1-x)Te2N3 features isolated linear N-Fe-N units with iron in the rare Fe(1+) state. The magnetic behavior of the iron site was characterized by magnetic susceptibility measurements, which indicate a very high magnetic moment (5.16μB) likely due to a high degree of spin-orbit coupling. Inherent disorder at the Fe/Li mixed site frustrates long-range communication between magnetic centers. PMID:27479366

  6. Candidate Mentor Supervisor Model: A Case Study

    ERIC Educational Resources Information Center

    Allen, Kristine M.

    2013-01-01

    The purpose of this research was to better understand affordances and constraints of the Candidate Mentor Supervisor Model (CMSM) as experienced by teacher candidates and their mentor supervisors. The results indicated perceived benefits to teacher candidates. Candidates participating in the CMSM reported a sense of nested support within their…

  7. Enthalpy screen of drug candidates.

    PubMed

    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. PMID:27567994

  8. Enthalpy screen of drug candidates.

    PubMed

    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.

  9. Leishmaniasis: vaccine candidates and perspectives.

    PubMed

    Singh, Bhawana; Sundar, Shyam

    2012-06-01

    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.

  10. OPTOPUS observations of quasar candidates.

    NASA Astrophysics Data System (ADS)

    Cristiani, S.

    1987-06-01

    OPTOPUS is a fiber-optic instrument for multiple-object spectroscopy with the Boiler & Chivens spectrograph and a CCD detector at the 3.6-m telescope. The system has been described in detail by the Optical Instrumentation Group (1985, The Messenger 41,25). Its application for observing Halley's comet has been reported by Lund and Surdej (1986, The Messenger 43, 1). Here another "classical" use of multiple-object spectroscopy is presented: followup observations of quasar candidates.

  11. Kepler Discovers Earth-size Planet Candidates

    NASA Video Gallery

    NASA's Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet's surface. Five of th...

  12. 11 CFR 110.13 - Candidate debates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2) Broadcasters...), provided that they are not owned or controlled by a political party, political committee or candidate. In... political party as the sole objective criterion to determine whether to include a candidate in a debate....

  13. 11 CFR 100.154 - Candidate debates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Expenditures § 100.154 Candidate debates. Funds used to defray costs incurred in staging candidate debates in accordance with the provisions of 11 CFR 110.13 and 114.4(f) are not expenditures. ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate debates. 100.154 Section...

  14. 11 CFR 100.92 - Candidate debates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Contributions § 100.92 Candidate debates. Funds provided to defray costs incurred in staging candidate debates in accordance with the provisions of 11 CFR 110.13 and 114.4(f) are not contributions. ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Candidate debates. 100.92 Section...

  15. Teacher Candidate Dispositions: Perspectives of Professional Expectations

    ERIC Educational Resources Information Center

    Wake, Donna; Bunn, Gary

    2016-01-01

    This study describes a programmatic effort to examine dispositions perceptions of teacher candidates entering the profession. Study participants included 114 master's level teaching candidates in their first semester of a nontraditional teacher education program. Teacher candidates scored themselves on a department disposition rubric designed to…

  16. Phase Diagram of HgTe -ZnTe Pseudobinary and Density, Heat Capacity, and Enthalphy of Mixing of Hg(sub 1-x)Zn(sub x)Te Pseudobinary Melts

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Sha, Yi-Gao; Mazuruk, K.; Lehoczky, S. L.

    1996-01-01

    In this article, the solidus temperatures of the Hg(sub 1-x) Zn(sub x)Te pseudobinary phase diagram for several compositions in the low x region were measured by differential thermal analysis and the HgTe-ZnTe pseudobinary phase diagram was constructed. The densities of two HgZnTe melts, x = 0.10 and 0.16, were determined by an in situ pycnometric technique in a transparent furnace over, respectively, 110 and 50 C ranges of temperature. The thermodynamic properties of the melts, such as the heat capacity and enthalpy of mixing, were calculated for temperatures between the liquidus and 1500 C by assuming an associated solution model for the liquid phase.

  17. Identification of category fourteen candidates

    SciTech Connect

    Not Available

    1980-02-29

    In recognition of the need of the Nation to conserve energy and the responsibility of the Government to achieve this end, Congress has enacted the Energy Policy and Conservation Act (EPCA, PL 94-163), as amended by the National Energy Conservation Policy Act (NECPA, PL 95-619). These laws give the Secretary of Energy the mandate to prescribe energy efficiency standards for fourteen categories of energy-using consumer products. The Acts identify thirteen categories of appliances for which standards are required. In addition, DOE may identify any other type of consumer product (in ''Category 14'') for which energy efficiency standards may be promulgated. NECPA requires that DOE publish in the ''Federal Register'' a list of the consumer products selected to be included in Category 14 by November 1980. This study examines household consumer appliances to identify Category 14 candidates on the basis of the first two criteria listed above.

  18. Lutetium +: A better clock candidate

    NASA Astrophysics Data System (ADS)

    Arnold, Kyle; Paez, Eduardo; Haciyev, Elnur; Arifin, Arifin; Cazan, Radu; Barrett, Murray

    2015-05-01

    With the extreme precision now reached by optical clocks it is reasonable to consider redefinition of the frequency standard. In doing so it is important to look beyond the current best-case efforts and have an eye on future possibilities. We will argue that singly ionized Lutetium is a strong candidate for the next generation of optical frequency standards. Lu + has a particularly narrow optical transition in combination with several advantageous properties for managing systematic uncertainties compared to the other atomic species. We summarize these properties and our specific strategies for managing the uncertainties due to external perturbations. Finally, we present the status of our ongoing experiments with trapped Lu +, including the results of precision measurements of its atomic structure.

  19. Advising Doctorate Candidates and Candidates' Views during the Dissertation Process

    ERIC Educational Resources Information Center

    Hilliard, Ann T.

    2013-01-01

    In order to provide candidates with effective advisement, it is important for the advisor to continue to practice positive professional relationships and provide relevant academic support to candidates. The advisor should work closely with other faculty members and need to listen to the voices of candidates to ensure candidates' success. What…

  20. XTE J1550-564

    NASA Technical Reports Server (NTRS)

    Finger, Mark H.; Dieters, Stefan W.; Wilson, Robert B.

    1998-01-01

    A quasiperiodic oscillation (QPO) in the flux of this transient x-ray source is seen in power spectra of the BATSE 20-50-keV discriminator rates. On Sept. 9.0 UT, the QPO was centered on 271 +/- 2 mHz, and it had a FWHM of 30 +/- 5 mHz and a fractional rms of 19.2 +/- 2.5 percent. The QPO was first detected on Sept. 7.45 near 55 mHz and has been steadily increasing in frequency, reaching 350 mHz by Sept. 9.3. The QPO appears to have reached the Nyquist frequency (488 mHz) of our discriminator rates before the end of Sept. 9, and is no longer detectable in them.

  1. Newly identified YSO candidates towards LDN 1188

    NASA Astrophysics Data System (ADS)

    Marton , G.; Verebélyi, E.; Kiss, Cs.; Smidla, J.

    2013-11-01

    We present an analysis of young stellar object (YSO) candidates towards the LDN 1188 molecular cloud. The YSO candidates were selected from the WISE all-sky catalogue, based on a statistical method. We found 601 candidates in the region, and classified them as Class I, Flat, and Class II YSOs. Groups were identified and described with the Minimal Spanning Tree (MST) method. Previously identified molecular cores show evidence of ongoing star formation at different stages throughout the cloud complex.

  2. Special Education Teacher Candidate Assessment: A Review

    ERIC Educational Resources Information Center

    McCall, Zach; McHatton, Patricia Alvarez; Shealey, Monika Williams

    2014-01-01

    Teacher preparation has been under intense scrutiny in recent years. In order for preparation of special education teacher candidates to remain viable, candidate assessment practices must apply practices identified in the extant literature base, while special education teacher education researchers must extend this base with rigorous efforts to…

  3. 11 CFR 9032.2 - Candidate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND: PRESIDENTIAL PRIMARY MATCHING FUND DEFINITIONS § 9032.2 Candidate. Candidate means an individual who seeks nomination for election to..., convention, primary election or run-off election; (b) Receives contributions or incurs qualified...

  4. 11 CFR 9032.2 - Candidate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Elections FEDERAL ELECTION COMMISSION PRESIDENTIAL ELECTION CAMPAIGN FUND: PRESIDENTIAL PRIMARY MATCHING FUND DEFINITIONS § 9032.2 Candidate. Candidate means an individual who seeks nomination for election to..., convention, primary election or run-off election; (b) Receives contributions or incurs qualified...

  5. Critical Thinking Tendencies among Teacher Candidates

    ERIC Educational Resources Information Center

    Genc, Salih Zeki

    2008-01-01

    The study aims to determine critical thinking tendencies among teacher candidates. 720 students from primary school teaching department (Primary School Teaching Programme, Science Teaching Programme and Pre-School Teaching Programme) form the sample of the study. When the gender and age distributions were investigated, 253 candidates are males and…

  6. 47 CFR 76.206 - Candidate rates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Candidate rates. 76.206 Section 76.206 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.206 Candidate rates. (a) Charges for use of cable...

  7. 47 CFR 76.206 - Candidate rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Candidate rates. 76.206 Section 76.206 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.206 Candidate rates. (a) Charges for use of cable...

  8. 47 CFR 76.206 - Candidate rates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Candidate rates. 76.206 Section 76.206 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.206 Candidate rates. (a) Charges for use of cable...

  9. 47 CFR 76.206 - Candidate rates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Candidate rates. 76.206 Section 76.206 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.206 Candidate rates. (a) Charges for use of cable...

  10. 47 CFR 76.206 - Candidate rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Candidate rates. 76.206 Section 76.206 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cablecasting § 76.206 Candidate rates. (a) Charges for use of cable...

  11. Portfolio Development for Teacher Candidates. ERIC Digest.

    ERIC Educational Resources Information Center

    Takona, James P.

    This Digest is intended to help teacher candidates systematically gauge their progress toward the teaching profession by developing a portfolio. Portfolios are one way to assess teacher candidates, and they are a major requirement for experienced teachers seeking board certification from the National Board for Professional Teaching Standards. The…

  12. When parties and candidates collide: citizen perception of house candidates' positions on abortion.

    PubMed

    Koch, J W

    2001-01-01

    When candidates assume issue positions opposite those of their sponsoring political party do citizens recognize these positions? Relatedly, what role do candidates' actual issue positions play in citizens' perceptions of their issue positions? Examining citizens' perceptions of 1996 and 1998 House candidates' position on abortion, this research finds that citizens' perceptions are shaped largely by partisan and, to a lesser extent, gender stereotypes. However, candidates' individuating positions on abortion influence perceptions of the candidates' position, but the effects are considerably stronger for perceptions of Republican candidates. Democratic candidates are likely to adopt anti-abortion positions in districts characterized by lower than average levels of political awareness and education, reducing the likelihood their party-contradicting position is accurately perceived. In contrast, Republican candidates adopt a pro-choice position in districts characterized by high education and political awareness, increasing the likelihood their position is accurately perceived. PMID:11264052

  13. BK Viremia among Iranian Renal Transplant Candidates

    PubMed Central

    Jozpanahi, Manizheh; Ramezani, Amitis; Ossareh, Shahrzad; Banifazl, Mohammad; Bavand, Anahita; Mamishi, Setareh; Aghakhani, Arezoo

    2016-01-01

    Background: Primary infection with BK virus (BKV) is occurred during childhood and usually asymptomatic, but after initial infection, BKV may persist lifelong in the kidney and genitourinary tract. Reactivation may occur in individuals with compromised immunity such as renal transplant recipients. Due to the role of BKV in BK virus-associated nephropathy (BKVAN) and potentially renal allograft rejection, the detection of BKV in renal transplant candidates is very important. The aim of this study was to evaluate the frequency of BK viremia in end stage renal disease cases who were candidates for renal transplantation. Methods: In this cross-sectional study, 50 cases with end stage renal disease who were candidates for renal transplantation were recruited from the main dialysis unit in Tehran, Iran. Presence of BK viremia was determined in plasma samples of cases using real time PCR. Results: A total of 50 renal transplant candidates with mean age 37.8±13 yr were enrolled in the study. Fifty two percent of subjects were male. Forty six (92%) of them were under HD and 4 (8%) were on PD. BK virus was not detected in any plasma samples of renal transplant candidates. Conclusion: This study showed absence of BK viremia in our renal transplant candidates. However, due to the important role of BKV in BKVAN and renal graft failure and rejection, further studies involving larger number of cases are required to elucidate the rate of the BKV in renal transplant candidates. PMID:27799969

  14. Undercover Stars Among Exoplanet Candidates

    NASA Astrophysics Data System (ADS)

    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

  15. Candidates for GRL North American coeditor sought

    NASA Astrophysics Data System (ADS)

    Geophysical Research Letters (GRL), AGU's all-Union primary research journal, is seeking candidates and nominations for candidates to succeed Rob Van der Voo, whose term as North American Coeditor ends December 31, 1986. The successful candidate will be challenged to seek out interesting papers at the forefront of the geophysical sciences and to attempt to strike a balance in the publication of that science that is of interest to the entire AGU membership. While complementing the interests of Editor in Chief Alex Dessler, the successful candidate will also be challenged to maintain rapid publication time and minimize the publication of research that is routine. The North American Coeditor should be prepared to welcome controversial research papers that challenge conventional wisdom in all fields of interest to AGU. The individual selected for this prestigious position will have a vital role in making GRL an even more important and more exciting journal that readers look forward to receiving each month.

  16. ECVAM'S activities in the EU candidate countries.

    PubMed

    Sladowski, Dariusz; Halder, Marlies

    2002-12-01

    ECVAM has been given a special grant for collaborative projects on alternative/advanced testing methods involving eleven Candidate Countries for membership of the European Union (Bulgaria, Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia). The project involves the promotion of the Three Rs (reduction, refinement, replacement) concept of Russell & Burch, in cooperation with appropriate individuals and national and international organisations in the Candidate Countries themselves, and elsewhere. The scope of the programme's activities covers: conferences in some of the Candidate Countries, workshops, training courses, training visits, and technology development/transfer initiatives. A database of contacts in the Candidate Countries and in relevant institutions in other countries, is being compiled. PMID:12513675

  17. Seven Democratic Presidential Candidates Debate Educational Issues.

    ERIC Educational Resources Information Center

    Equity and Excellence, 1988

    1988-01-01

    Provides the transcript of a debate on educational issues among Democratic presidential candidates Paul Simon, Albert Gore, Joseph Biden, Jesse Jackson, Bruce Babbitt, Richard Gephart, and Michael Dukakis. (BJV)

  18. Triton stellar occultation candidates - 1992-1994

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. T.

    1992-01-01

    A search for Triton stellar occultation candidates for the period 1992-1994 has been completed with CCD strip-scanning observations. The search reached an R magnitude of about 17.4 and found 129 candidates within 1.5 arcsec of Triton's ephemeris during this period. Of these events, around 30 occultations are expected to be visible from the earth, indicating that a number of Triton occultation events should be visible from major observatories. Even the faintest of the present candidate events could produce useful occultation data if observed with a large enough telescope. The present astrometric accuracy is inadequate to identify which of these appulse events will produce occultations on the earth; further astrometry is needed to refine the predictions for positive occultation identification. To aid in selecting candidates for additional astrometric and photometric studies, finder charts and earth-based visibility charts for each event are included.

  19. Candidate preferences and expectations of election outcomes

    PubMed Central

    Delavande, Adeline; Manski, Charles F.

    2012-01-01

    Analysis of data from the American Life Panel shows that in the presidential election of 2008 and in multiple statewide elections in 2010, citizens exhibited large differences in their expectations of election outcomes. Expectations were strongly positively associated with candidate preferences, persons tending to believe that their preferred candidate is more likely to win the election. Committed supporters of opposing candidates regularly differed by 20–30% in their assessments of the likelihood that each candidate would win. These findings contribute evidence on the false consensus effect, the empirical regularity that own preferences tend to be positively associated with perceptions of social preferences. We used unique measures of preferences and perceptions that enabled respondents to express uncertainty flexibly. We studied a setting that would a priori seem inhospitable to false consensus—one where persons have little private information on social preferences but substantial common knowledge provided by media reports of election polls. PMID:22355121

  20. ECVAM'S activities in the EU candidate countries.

    PubMed

    Sladowski, Dariusz; Halder, Marlies

    2002-12-01

    ECVAM has been given a special grant for collaborative projects on alternative/advanced testing methods involving eleven Candidate Countries for membership of the European Union (Bulgaria, Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia). The project involves the promotion of the Three Rs (reduction, refinement, replacement) concept of Russell & Burch, in cooperation with appropriate individuals and national and international organisations in the Candidate Countries themselves, and elsewhere. The scope of the programme's activities covers: conferences in some of the Candidate Countries, workshops, training courses, training visits, and technology development/transfer initiatives. A database of contacts in the Candidate Countries and in relevant institutions in other countries, is being compiled.

  1. Towards Treating Chemistry Teacher Candidates as Human

    NASA Astrophysics Data System (ADS)

    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.

  2. Vaccine candidates for malaria: what's new?

    PubMed

    Takashima, Eizo; Morita, Masayuki; Tsuboi, Takafumi

    2016-01-01

    Although it is more than a decade since the parasite genome information was obtained, standardized novel genome-wide selection/prioritization strategies for candidacy of malaria vaccine antigens are still sought. In the quest to systematically identify candidates, it is impossible to overemphasize the usefulness of wheat germ cell-free technology in expressing quality proteins for the post-genome vaccine candidate discovery.

  3. A PROPELLER-EFFECT INTERPRETATION OF MAXI/GSC LIGHT CURVES OF 4U 1608-52 AND Aql X-1 AND APPLICATION TO XTE J1701-462

    SciTech Connect

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

    2013-08-20

    We present the luminosity dwell-time distributions during the hard states of two low-mass X-ray binaries containing a neutron star (NS), 4U 1608-52 and Aql X-1, observed with MAXI/GSC. The luminosity distributions show a steep cutoff on the low-luminosity side at {approx}1.0 Multiplication-Sign 10{sup 36} erg s{sup -1} in both sources. The cutoff implies a rapid luminosity decrease in their outburst decay phases and this decrease can be interpreted as being due to the propeller effect. We estimate the surface magnetic field of 4U 1608-52 to be (0.5-1.6) Multiplication-Sign 10{sup 8} G and Aql X-1 to be (0.6-1.9) Multiplication-Sign 10{sup 8} G from the cutoff luminosity and apply the same propeller mechanism to the similar rapid luminosity decrease observed in the transient Z source, XTE J1701-462, with RXTE/ASM. Assuming that the spin period of the NS is on the order of milliseconds, the observed cutoff luminosity implies a surface magnetic field on the order of 10{sup 9} G.

  4. Analysis of the Influence of Thermal Treatment on the Stability of Ag1-xSb1+xTe2+x and Se-Doped AgSbTe2

    NASA Astrophysics Data System (ADS)

    Wyzga, P. M.; Wojciechowski, K. T.

    2016-03-01

    In order to systematize the knowledge on thermodynamic stability and thermoelectric properties of AgSbTe2-based alloys, several experiments examining the influence of thermal treatment on their structural and thermoelectric properties were performed. Samples with a nominal composition of AgSbTe2 and AgSbTe1.98Se0.02 were prepared and then annealed in various temperature conditions. It was confirmed that Ag1-xSb1+xTe2+x ( β phase) is the only thermodynamically stable ternary compound in the Ag2Te-Sb2Te3 pseudobinary system. It was also proved that thermal stability of β phase is limited—it slowly decomposes below 633 K. In contrast to some reports, it was also indicated that a small amount of Se does not lead to stabilisation of AgSbTe2 crystal structure. Despite slow kinetics of the decomposition processes, thermoelectric properties of the material are notably affected by thermal treatment and amount of Ag2Te precipitations. Maximal ZT value of prepared materials varies from 0.65 at 575 K to 1.07 at 563 K.

  5. A New Way to Confirm Planet Candidates

    NASA Astrophysics Data System (ADS)

    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

  6. Spectroscopy of Kepler Candidate Exoplanet Host Stars

    NASA Astrophysics Data System (ADS)

    Everett, Mark E.; Howell, Steve B.; Silva, David R.; Szkody, Paula

    2014-02-01

    Currently the NASA Kepler Mission has identified 3449 exoplanet candidates, one third with estimated radii R_p<2.5R_oplus and orbiting faint (m_Kep>14.5) host stars. The NASA sponsored Kepler Follow-up Program is focusing on small exoplanet candidates (R_p<2.5R_oplus) and those in habitable zone orbits. Planet radii estimates depend on estimates of host star radii. Based on spectra previously obtained at the KPNO Mayall 4-m for 220 stars with candidate exoplanets, Everett et al. (2013) have shown that many host stars are larger than originally assumed (up to factor of 2). Therefore, the exoplanet candidates they host must be larger than originally assumed, which conversely reduces the number of known Earth- sized exoplanet candidates. Determination of the frequency of such Earth-sized planets is a cornerstone Kepler mission objective and of keen general interest. These Mayall spectra were also used to confirm the Buchhave et al. (2012) result that exoplanet candidates larger than 4R_oplus in short-period orbits are preferentially associated with host stars with solar or higher metallicity, using a fainter and larger sample of stars than Buchhave et al. In short, followup Mayall optical spectroscopy is critical to confirming the detection of Earth-sized exoplanets, a Kepler cornerstone goal, as well as characterizing the relationship between host star properties and planetary system properties. Here, we propose to continue our reconnaissance survey with a focus on the smallest (most rare) exoplanet candidates orbiting the faintest Kepler host stars.

  7. Jellyfish Galaxy Candidates at Low Redshift

    NASA Astrophysics Data System (ADS)

    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⊙ < 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.

  8. Phenoscape: Identifying Candidate Genes for Evolutionary Phenotypes.

    PubMed

    Edmunds, Richard C; Su, Baofeng; Balhoff, James P; Eames, B Frank; Dahdul, Wasila M; Lapp, Hilmar; Lundberg, John G; Vision, Todd J; Dunham, Rex A; Mabee, Paula M; Westerfield, Monte

    2016-01-01

    Phenotypes resulting from mutations in genetic model organisms can help reveal candidate genes for evolutionarily important phenotypic changes in related taxa. Although testing candidate gene hypotheses experimentally in nonmodel organisms is typically difficult, ontology-driven information systems can help generate testable hypotheses about developmental processes in experimentally tractable organisms. Here, we tested candidate gene hypotheses suggested by expert use of the Phenoscape Knowledgebase, specifically looking for genes that are candidates responsible for evolutionarily interesting phenotypes in the ostariophysan fishes that bear resemblance to mutant phenotypes in zebrafish. For this, we searched ZFIN for genetic perturbations that result in either loss of basihyal element or loss of scales phenotypes, because these are the ancestral phenotypes observed in catfishes (Siluriformes). We tested the identified candidate genes by examining their endogenous expression patterns in the channel catfish, Ictalurus punctatus. The experimental results were consistent with the hypotheses that these features evolved through disruption in developmental pathways at, or upstream of, brpf1 and eda/edar for the ancestral losses of basihyal element and scales, respectively. These results demonstrate that ontological annotations of the phenotypic effects of genetic alterations in model organisms, when aggregated within a knowledgebase, can be used effectively to generate testable, and useful, hypotheses about evolutionary changes in morphology. PMID:26500251

  9. Evaluating historical candidate genes for schizophrenia.

    PubMed

    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.

  10. Evaluating Historical Candidate Genes for Schizophrenia

    PubMed Central

    Farrell, Martilias; Werge, Thomas; Sklar, Pamela; Owen, Michael J.; Ophoff, Roel; O’Donovan, Michael; Corvin, Aiden; Cichon, Sven; Sullivan, Patrick F

    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 (e.g., 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. PMID:25754081

  11. Phenoscape: Identifying Candidate Genes for Evolutionary Phenotypes

    PubMed Central

    Edmunds, Richard C.; Su, Baofeng; Balhoff, James P.; Eames, B. Frank; Dahdul, Wasila M.; Lapp, Hilmar; Lundberg, John G.; Vision, Todd J.; Dunham, Rex A.; Mabee, Paula M.; Westerfield, Monte

    2016-01-01

    Phenotypes resulting from mutations in genetic model organisms can help reveal candidate genes for evolutionarily important phenotypic changes in related taxa. Although testing candidate gene hypotheses experimentally in nonmodel organisms is typically difficult, ontology-driven information systems can help generate testable hypotheses about developmental processes in experimentally tractable organisms. Here, we tested candidate gene hypotheses suggested by expert use of the Phenoscape Knowledgebase, specifically looking for genes that are candidates responsible for evolutionarily interesting phenotypes in the ostariophysan fishes that bear resemblance to mutant phenotypes in zebrafish. For this, we searched ZFIN for genetic perturbations that result in either loss of basihyal element or loss of scales phenotypes, because these are the ancestral phenotypes observed in catfishes (Siluriformes). We tested the identified candidate genes by examining their endogenous expression patterns in the channel catfish, Ictalurus punctatus. The experimental results were consistent with the hypotheses that these features evolved through disruption in developmental pathways at, or upstream of, brpf1 and eda/edar for the ancestral losses of basihyal element and scales, respectively. These results demonstrate that ontological annotations of the phenotypic effects of genetic alterations in model organisms, when aggregated within a knowledgebase, can be used effectively to generate testable, and useful, hypotheses about evolutionary changes in morphology. PMID:26500251

  12. Screening restimulation candidates in the Antrim Shale

    SciTech Connect

    Hopkins, C.W.; Frantz, J.H. Jr.; Tatum, C.L.; Hill, D.G.

    1994-12-31

    This paper describes a simple method to identify, prioritize, and evaluate restimulation candidates in the Antrim Shale of the Michigan Basin. This work is being performed as part of an ongoing field-based Gas Research Institute (GRI) project investigating the Antrim Shale. There are between 500 and 1,000 Antrim Shale wells which could be candidates for restimulation due to previous screenouts and/or flowback problems, when sand consolidation material was not used. However, all of these wells might not benefit from restimulation, due to either poor reservoir quality or because the wells are already effectively stimulated. Based on historical results, the authors estimate the increase in reserves from restimulation could be between 50 and 400 MMscf per well, which could add 50 to 200 Bscf in future reserves from the 500--1,000 candidate wells.

  13. SOPHIE velocimetry of Kepler transit candidates

    NASA Astrophysics Data System (ADS)

    Santerne, A.; Moutou, C.; Bouchy, F.; Hébrard, G.; Deleuil, M.; Díaz, R. F.; Bonomo, A. S.; Almenara, J.-M.

    2011-10-01

    As CoRoT, the Kepler space mission found a large amount of planetary transit candidates for which radial velocity follow-up is necessary in order to establish the planetary nature and then, to characterize the mass of the transiting companion. We are following up some interesting Kepler candidates with the SOPHIE spectrograph mounted at the 1.93-m telescope in Observatoire de Haute Provence (France). More than one year after the first Kepler release, we will present the strategy used to select the most promising Kepler candidates, within reach of a detection with SOPHIE, using the experience of more than 4 years of CoRoT, SWASP and HAT radial velocity follow-up. We will also highlight the results of the first year of observations that led to the discovery of several new transiting exoplanets and help the understanding of the false positive rate of the Kepler mission.

  14. Isolated dextrocardia in a commercial pilot candidate.

    PubMed

    Syburra, Thomas; Sütsch, Gabor; Huber, Samuel; Schnüriger, Hans; Lachat, Mario; Suter, Jost

    2005-02-01

    Positional anomalies of the heart are rare and are seldom found during routine physical examinations. We describe the case of a 25-yr-old Swiss airline pilot candidate whose aeromedical examination was normal except that an unusual ECG raised suspicion, leading to a diagnosis of dextrocardia with a normal arrangement of atria and abdominal viscera. This diagnosis in a pilot candidate should raise concern because a high percentage of such individuals have congenital heart defects. Further tests were conducted to rule out associated cardiac malformations, conduction anomalies, or rhythm disturbances. Testing also excluded other associated diseases such as primary ciliary dyskinesia and Kartagener's syndrome. Dextrocardia is not listed as a disqualifying condition in the applicable aeromedical regulations (Joint Aviation Authorities Medical Manual, Joint Aviation Requirements-Flight Crew Licensing guidelines). Therefore, after demonstrating that there were no physical, hemodynamic, or electrophysiological abnormalities, the candidate was allowed to enroll in civilian pilot training without restrictions.

  15. Developing Potential Candidates of Preclinical Preeclampsia

    PubMed Central

    Founds, Sandra; Zeng, Xuemei; Lykins, David; Roberts, James M.

    2015-01-01

    The potential for developing molecules of interest in preclinical preeclampsia from candidate genes that were discovered on gene expression microarray analysis has been challenged by limited access to additional first trimester trophoblast and decidual tissues. The question of whether these candidates encode secreted proteins that may be detected in maternal circulation early in pregnancy has been investigated using various proteomic methods. Pilot studies utilizing mass spectrometry based proteomic assays, along with enzyme linked immunosorbent assays (ELISAs), and Western immunoblotting in first trimester samples are reported. The novel targeted mass spectrometry methods led to robust multiple reaction monitoring assays. Despite detection of several candidates in early gestation, challenges persist. Future antibody-based studies may lead to a novel multiplex protein panel for screening or detection to prevent or mitigate preeclampsia. PMID:26580600

  16. Issue-Advocacy versus Candidate Advertising: Effects on Candidate Preferences and Democratic Process.

    ERIC Educational Resources Information Center

    Pfau, Michael; Holbert, R. Lance; Szabo, Erin Alison; Kaminski, Kelly

    2002-01-01

    Examines the influence of soft-money-sponsored issue-advocacy advertising in U.S. House and Senate campaigns, comparing its effects against candidate-sponsored positive advertising and contrast advertising on viewers' candidate preferences and on their attitude that reflect democratic values. Reveals no main effects for advertising approach on…

  17. Query by image example: The CANDID approach

    SciTech Connect

    Kelly, P.M.; Cannon, M.; Hush, D.R.

    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.

  18. Social Justice Perceptions of Teacher Candidates

    ERIC Educational Resources Information Center

    Turhan, Muhammed

    2010-01-01

    This study aims to determine the social justice perceptions of teacher candidates being trained in an education faculty. For this purpose, national and international literature was reviewed by the researcher and a 32-item questionnaire was developed and implemented on 237 senior year education faculty students. Data from the questionnaires were…

  19. Towards Treating Chemistry Teacher Candidates as Human

    ERIC Educational Resources Information Center

    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…

  20. Measuring Credential Candidates' Impact on Student Achievement

    ERIC Educational Resources Information Center

    Hagans, Kristi S.; Powers, Kristin

    2015-01-01

    The Council for the Accreditation of Educator Preparation (CAEP) requires faculty from educator preparation programs to provide evidence of credential candidates' impact on K-12 student learning. However, there is a paucity of information on preparation programs' use of direct assessments of student learning to gauge credential candidate…

  1. Computer Teacher Candidates' Metaphors about the Internet

    ERIC Educational Resources Information Center

    Saban, Aslihan

    2010-01-01

    The purpose of this study was to examine the metaphors of exit-level Turkish computer teacher candidates about the concept of "internet". Participants included 45 seniors (23 boys and 22 girls) majoring in the Department of Computer and Instructional Technologies at Selcuk University, Ahmet Kelesoglu Faculty of Education. They were asked to…

  2. 11 CFR 9003.2 - Candidate certifications.

    Code of Federal Regulations, 2010 CFR

    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...

  3. Waiting Narratives of Lung Transplant Candidates

    PubMed Central

    Yelle, Maria T.; Stevens, Patricia E.; Lanuza, Dorothy M.

    2013-01-01

    Before 2005, time accrued on the lung transplant waiting list counted towards who was next in line for a donor lung. Then in 2005 the lung allocation scoring system was implemented, which meant the higher the illness severity scores, the higher the priority on the transplant list. Little is known of the lung transplant candidates who were listed before 2005 and were caught in the transition when the lung allocation scoring system was implemented. A narrative analysis was conducted to explore the illness narratives of seven lung transplant candidates between 2006 and 2007. Arthur Kleinman's concept of illness narratives was used as a conceptual framework for this study to give voice to the illness narratives of lung transplant candidates. Results of this study illustrate that lung transplant candidates expressed a need to tell their personal story of waiting and to be heard. Recommendation from this study calls for healthcare providers to create the time to enable illness narratives of the suffering of waiting to be told. Narrative skills of listening to stories of emotional suffering would enhance how healthcare providers could attend to patients' stories and hear what is most meaningful in their lives. PMID:23476760

  4. Emotional Intelligence and Beginning Teacher Candidates

    ERIC Educational Resources Information Center

    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…

  5. Automatic Classification of Kepler Planetary Transit Candidates

    NASA Astrophysics Data System (ADS)

    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

    2015-06-01

    In the first three years of operation, the Kepler mission found 3697 planet candidates (PCs) from a set of 18,406 transit-like features detected on more than 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 PCs; all candidates are as credible as any other. The torrent of exoplanet discoveries will continue after Kepler, because a number of exoplanet surveys will have an even broader search area. This paper presents the application of machine-learning techniques to the classification of the exoplanet transit-like signals present in the Kepler light curve data. Transit-like detections are transformed into a uniform set of real-numbered attributes, the most important of which are described in this paper. Each of the known transit-like detections is assigned a class of PC; astrophysical false positive; or systematic, instrumental noise. We use a random forest algorithm to learn the mapping from attributes to classes on this training set. The random forest algorithm has been used previously to classify variable stars; this is the first time it has been used for exoplanet classification. We are able to achieve an overall error rate of 5.85% and an error rate for classifying exoplanets candidates of 2.81%.

  6. 11 CFR 9002.2 - Candidate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... pledged to him or her on such ballot) as the candidate of a political party for election to either such office in 10 or more States. For the purposes of this section, political party shall be defined in... presidential election, an individual who— (1) Has been nominated by a major party for election to the office...

  7. 11 CFR 9002.2 - Candidate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... pledged to him or her on such ballot) as the candidate of a political party for election to either such office in 10 or more States. For the purposes of this section, political party shall be defined in... presidential election, an individual who— (1) Has been nominated by a major party for election to the office...

  8. 11 CFR 9002.2 - Candidate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... pledged to him or her on such ballot) as the candidate of a political party for election to either such office in 10 or more States. For the purposes of this section, political party shall be defined in... presidential election, an individual who— (1) Has been nominated by a major party for election to the office...

  9. 11 CFR 110.13 - Candidate debates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... political parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2... CFR 114.4(f), provided that they are not owned or controlled by a political party, political committee... nomination by a particular political party as the sole objective criterion to determine whether to include...

  10. 11 CFR 9002.2 - Candidate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pledged to him or her on such ballot) as the candidate of a political party for election to either such office in 10 or more States. For the purposes of this section, political party shall be defined in... presidential election, an individual who— (1) Has been nominated by a major party for election to the office...

  11. 11 CFR 110.13 - Candidate debates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... political parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2... CFR 114.4(f), provided that they are not owned or controlled by a political party, political committee... nomination by a particular political party as the sole objective criterion to determine whether to include...

  12. 11 CFR 110.13 - Candidate debates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... political parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2... CFR 114.4(f), provided that they are not owned or controlled by a political party, political committee... nomination by a particular political party as the sole objective criterion to determine whether to include...

  13. 11 CFR 110.13 - Candidate debates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... political parties may stage candidate debates in accordance with this section and 11 CFR 114.4(f). (2... CFR 114.4(f), provided that they are not owned or controlled by a political party, political committee... nomination by a particular political party as the sole objective criterion to determine whether to include...

  14. 11 CFR 9002.2 - Candidate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... pledged to him or her on such ballot) as the candidate of a political party for election to either such office in 10 or more States. For the purposes of this section, political party shall be defined in... presidential election, an individual who— (1) Has been nominated by a major party for election to the office...

  15. HiTS additional supernova candidates

    NASA Astrophysics Data System (ADS)

    Forster, F.; Maureira, J. C.; Points, S.; Medina, G.; Munoz, R.; Martin, J. San; Hamuy, M.; Estevez, P.; Smith, R. C.; Vivas, K.; Flores, S.; Huijse, P.; Cabrera, G.; Anderson, J.; Bufano, F.; Gonzalez-Gaitan, S.; Galbany, L.; Pignata, G.; de Jaeger, Th.; Martinez, J.; Munoz, R.; Vera, E.; Perez, C.

    2015-03-01

    HiTS, the High Cadence Transient Survey (see ATELs #5949, #7099), reports the discovery of additional supernova candidates detected using an image subtraction / classification pipeline developed at the Center for Mathematical Modelling (CMM) in collaboration with the Millennium Institute for Astrophysics (MAS).

  16. Promoting Team Leadership Skills in Doctoral Candidates

    ERIC Educational Resources Information Center

    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…

  17. 47 CFR 73.1942 - Candidate rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... periods. Any station practices offered to commercial advertisers that enhance the value of advertising... in the rotation, including announcements aired under long-term advertising contracts. Stations may... advertising, shall be provided to candidates prior to election day if a station has provided a...

  18. Gallium-67 imaging in candidal esophagitis

    SciTech Connect

    Rundback, J.H.; Goldfarb, C.R.; Ongseng, F. )

    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.

  19. Enhancing Advocacy Skills of Teacher Candidates

    ERIC Educational Resources Information Center

    Holmes, Melissa A.; Herrera, Socorro G.

    2009-01-01

    This case study explores the dynamics of enhancing the capacities of teacher candidates in the Bilingual/Bicultural Education Students Interacting to Obtain Success (BESITOS) recruitment and retention program to advocate for culturally and linguistically diverse (CLD) students. Herrera and Murry's advocacy framework provides the theoretical…

  20. ESL Teacher-Candidates' Beliefs about Language

    ERIC Educational Resources Information Center

    Fleming, Douglas; Bangou, Francis; Fellus, Osnat

    2011-01-01

    How do ESL teacher-candidates grapple with beliefs about language during their professional training? In this article, we present the findings of a qualitative research study conducted in a large eastern Canadian university Bachelor of Education program. As Johnson (2010) has recently noted, despite extensive research and theoretical work that…

  1. The Responsibility Education of Teacher Candidates

    ERIC Educational Resources Information Center

    Toremen, Fatih

    2011-01-01

    In this study, it was aimed to take the views and suggestions of academicians working at the faculty of education on what can be done about teacher candidates' responsibility education. This study was designed on the basis of qualitative research approach and purposive sampling method was used. Data were collected by unstructured interview method…

  2. Collaboration with Community Partners: Engaging Teacher Candidates

    ERIC Educational Resources Information Center

    Gandy, S. Kay; Pierce, Judy; Smith, Alicia Brooke

    2009-01-01

    Two social studies methods instructors created an assignment that places teacher candidates in leadership roles in partnerships with community organizations to plan and implement projects to increase student learning. This article outlines the project requirements, past project results, and student reflections on the collaborative effort. It…

  3. STAR CLUSTER CANDIDATES IN M81

    SciTech Connect

    Nantais, Julie B.; Huchra, John P.; McLeod, Brian; Strader, Jay; Brodie, Jean P.

    2010-04-15

    We present a catalog of extended objects in the vicinity of M81 based on a set of 24 Hubble Space Telescope Advanced Camera for Surveys Wide Field Camera F814W (I-band) images. We have found 233 good globular cluster (GC) candidates; 92 candidate H II regions, OB associations, or diffuse open clusters; 489 probable background galaxies; and 1719 unclassified objects. We have color data from ground-based g- and r-band MMT Megacam images for 79 galaxies, 125 GC candidates, 7 H II regions, and 184 unclassified objects. The color-color diagram of GC candidates shows that most fall into the range 0.25 < g - r < 1.25 and 0.5 < r - I < 1.25, similar to the color range of Milky Way GCs. Unclassified objects are often blue, suggesting that many of them are likely to be H II regions and open clusters, although a few galaxies and GCs may be among them.

  4. 76 FR 36130 - Call for Candidates

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  5. Modeling Collaboration for ESL Teacher Candidates

    ERIC Educational Resources Information Center

    DelliCarpini, Margo

    2014-01-01

    This article reports on a semester-long project where a TESOL professor and English Education professor modeled collaborative teaching and explicitly taught collaboration skills to a coscheduled teaching methods class consisting of TESOL and Secondary English teacher candidates. Data were collected in the form of pre- and postsemester surveys. In…

  6. Secondary Teacher Candidates' Lesson Planning Learning

    ERIC Educational Resources Information Center

    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…

  7. Thermoelectric and microstructural properties of Pb{sub 0.9-x}Sn{sub 0.1}Ge{sub x}Te compounds prepared by spinodal decomposition

    SciTech Connect

    Sondergaard, M.; Christensen, M.; Johnsen, S.; Stiewe, C.; Dasgupta, T.; Mueller, E.; Iversen, B.B.

    2011-05-15

    Three samples of Pb{sub 0.9-x}Sn{sub 0.1}Ge{sub x}Te with x=0.25, 0.35, 0.6 were prepared by heating the mixtures above the melting point of the constituent elements followed by quenching in water. The x=0.6 sample is close to the center of the immiscibility region, while the x=0.25 and 0.35 samples are in the Pb rich region inside the spinodal miscibility gap. Microstructural investigations using Powder X-ray Diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy revealed both GeTe-rich and PbTe-rich phases. The samples were uniaxially hot pressed and the thermoelectric properties were characterized in the temperature range 2-400 K using a commercial apparatus and from 300 to 650 K with a custom designed setup. The best sample (x=0.6) reached zT{approx}0.6 at 650 K, while the x=0.25 and 0.35 samples showed thermal instability at elevated temperatures. -- Graphical abstract: Spinodal decomposition in the GeTe-SnTe-PbTe system demonstrated by SEM and EXS images. Display Omitted Highlights: {yields} Investigation of Pb-rich part of the spinodal miscibility gap in PbTe-SnTe-GeTe. {yields} zT=0.6 at 650 K reproduced for Pb{sub 0.3}Sn{sub 0.1}Ge{sub 0.6}Te. {yields} Pb-rich phases shown to be thermally instable. {yields} Thermoelectric property characterization at low and high temperature. {yields} Microstructural investigations using PXRD, SEM, EDX and PSM.

  8. 11 CFR 100.148 - Volunteer activity for candidate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2013-01-01 2012-01-01 true Volunteer activity for candidate. 100.148...) Exceptions to Expenditures § 100.148 Volunteer activity for candidate. The payment by a candidate for...

  9. 11 CFR 100.148 - Volunteer activity for candidate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2014-01-01 2014-01-01 false Volunteer activity for candidate. 100.148...) Exceptions to Expenditures § 100.148 Volunteer activity for candidate. The payment by a candidate for...

  10. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2013-01-01 2012-01-01 true Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  11. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2014-01-01 2014-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  12. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2011-01-01 2011-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  13. 11 CFR 100.148 - Volunteer activity for candidate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2012-01-01 2012-01-01 false Volunteer activity for candidate. 100.148...) Exceptions to Expenditures § 100.148 Volunteer activity for candidate. The payment by a candidate for...

  14. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2012-01-01 2012-01-01 false Volunteer activity for candidates. 100.88...) Exceptions to Contributions § 100.88 Volunteer activity for candidates. (a) The payment by a candidate...

  15. 11 CFR 100.148 - Volunteer activity for candidate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... developed by the candidate. But see 11 CFR 100.24, 104.17(a), and part 300, subparts D and E for exempt... 11 Federal Elections 1 2011-01-01 2011-01-01 false Volunteer activity for candidate. 100.148...) Exceptions to Expenditures § 100.148 Volunteer activity for candidate. The payment by a candidate for...

  16. 14 CFR 91.321 - Carriage of candidates in elections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Carriage of candidates in elections. 91.321 Section 91.321 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... for carrying a candidate, agent of a candidate, or person traveling on behalf of a candidate,...

  17. 22 CFR 11.8 - Travel expenses of candidates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Travel expenses of candidates. 11.8 Section 11... Travel expenses of candidates. The travel and other personal expenses of candidates incurred in... Department may issue round-trip invitational travel orders to bring candidates to Washington at...

  18. 22 CFR 11.8 - Travel expenses of candidates.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Travel expenses of candidates. 11.8 Section 11... Travel expenses of candidates. The travel and other personal expenses of candidates incurred in... Department may issue round-trip invitational travel orders to bring candidates to Washington at...

  19. 14 CFR 91.321 - Carriage of candidates in elections.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Carriage of candidates in elections. 91.321 Section 91.321 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... for carrying a candidate, agent of a candidate, or person traveling on behalf of a candidate,...

  20. Candidate marketing takes the guessing game out of choosing employers.

    PubMed

    Russell, Judith; Havel, Stacey

    2010-01-01

    Candidate marketing builds a foundation for relationships between employers and potential employees. Additionally, candidate marketing differentiates organizations in the marketplace. Organizations using candidate marketing to communicate the employer brand can expect a higher quality of candidates, and new employees are better prepared for the work environment and culture. Today, organizations can use a variety of integrated tools and techniques to communicate and build relationships with candidates. Candidate marketing demonstrates an organization's willingness towards transparency, and ability to invite open conversations between candidates and members of the organizations. PMID:20672542

  1. Candidate marketing takes the guessing game out of choosing employers.

    PubMed

    Russell, Judith; Havel, Stacey

    2010-01-01

    Candidate marketing builds a foundation for relationships between employers and potential employees. Additionally, candidate marketing differentiates organizations in the marketplace. Organizations using candidate marketing to communicate the employer brand can expect a higher quality of candidates, and new employees are better prepared for the work environment and culture. Today, organizations can use a variety of integrated tools and techniques to communicate and build relationships with candidates. Candidate marketing demonstrates an organization's willingness towards transparency, and ability to invite open conversations between candidates and members of the organizations.

  2. Presidential candidates focus on energy policy

    SciTech Connect

    Lessard, P.; Belcher, J.

    1996-09-01

    When gasoline prices skyrocketed this past spring, sparking outcries from both the American public and lawmakers on Capitol Hill, the need for a national energy policy suddenly was pushed to the forefront. The attention the higher gasoline prices received has helped focus debate on an even more pressing issue-the real threat to the U.S. economy and national security when Americans cannot get enough oil, regardless of price, to fuel their industrial and transportation needs and, in some parts of the country, to heat their homes. While presidential candidates Bill Clinton and Bob Dole disagree with each other in many areas, with energy policy being no exception, both have expressed the opinion that the U.S. needs to be less reliant on foreign, and often unstable, countries for sources of fuel, such as oil. An exclusive interview with the candidates` respective campaigns about their views on issues facing the domestic oil and natural gas industry is presented.

  3. Communication strategies of adult cochlear implant candidates.

    PubMed

    Elfenbein, J L; Lansing, C R; Davis, J M; Kallaus-Gay, A

    1994-01-01

    Adult cochlear implant candidates' abilities to cope with communication breakdown were assessed using the Communication Strategies Task (CST). Forty adult cochlear implant candidates with acquired hearing losses and 10 adults with normal hearing served as subjects. Appropriateness of responses to the CST were rated by 10 certified speech-language pathologists and audiologists. Seventy-six percent of the subjects demonstrated difficulty identifying onset or resolution of communication breakdown, communicators' feelings, factors contributing to communication breakdown, and appropriate repair strategies. The responses of individuals with sudden hearing losses did not differ significantly from the responses of individuals with progressive hearing losses. Response patterns did not correlate with the age of onset of the hearing loss, duration of deafness, age at the time of evaluation, or educational background. The results of this study suggest that ability to cope with communication breakdown must be evaluated on an individual basis. PMID:8155895

  4. SAO RAS spectral classification of SN candidates

    NASA Astrophysics Data System (ADS)

    Fatkhullin, T. A.; Moskvitin, A. S.

    2016-08-01

    We observed five SN candidates (AT 2016eld, AT 2016eku, MASTER OT J225939.54+020859.6, AT 2016ekw and AT 2016elw) with the BTA/Scorpio-I on the night of August, 2/3. Direct images in the V band and long-slit spectra in the range of 3600-7600AA (resolution FWHM = 10A) were obtained.

  5. New Young Star Candidates in BRC 27

    NASA Astrophysics Data System (ADS)

    Novatne, Lauren J.; Mattrocce, G.; Milan, T.; Quinonez, A.; Rebull, L. M.; Barge, J.; Amayo, R.; Bieber, H.; Block, L.; Cheung, E.; Cruz, A.; Elkin, D.; Figueroa, A.; Jakus, M.; Kelo, A.; Larson, O.; Lemma, B.; Li, Y.; Loe, C.; Maciag, V.; Moreno, N.; Nevels, M.; Pezanoski-Cohen, G.; Short, M.; Skatchke, K.; Tur-Kaspa, A.; Zegeye, D.; Armstrong, J.; Bonadurer, R.; French, D.; Free, B.; Miller, C.; Scherich, H.; Willis, T.; Koenig, X.; Laher, R.; Padgett, D.; Piper, M.; Pavlak, A.; Piper, M.; Venezio, E.; Ali, B.

    2013-01-01

    All stars originate from clouds of interstellar gas that collapse either under their own gravity or with external help. In triggered star formation, the collapse of a cloud is initiated by pressure, e.g., from nearby star(s). When the external source is bright stars, it can illuminate the rims of the cloud, creating bright-rimmed clouds (BRCs) to be visible at optical and infrared (IR) wavelengths. We searched for new candidate young stellar objects (YSOs) primarily using the March 2012 all-sky release of Wide-field Infrared Survey Explorer (WISE) data in BRC 27, which is part of CMa R1, a region of known star formation. Spitzer data of a 5’x5’ region centered on BRC 27 were presented by Johnson et al. 2012 and Rebull et al. 2012. We investigated WISE data within a 20 arcminute radius of BRC 27 0.35 sq. deg), combining it with Spitzer data serendipitously obtained in this region, 2MASS data, and optical data. We started from nearly 4000 WISE sources and identified about 200 candidate YSOs via a series of color cuts (Koenig et al. 2012) to identify objects with WISE colors consistent with other YSOs, e.g., having an apparent IR excess. There are about 100 objects in this region already identified in the literature as possible YSOs, about 40 of which we recovered with the color cuts. We investigated these literature YSOs and YSO candidates in all available images, and created spectral energy distributions (SEDs) and color-magnitude diagrams for further analysis of each object. We will present an analysis of our selected sub-sample of YSO candidates. This research was made possible through the NASA/IPAC Teacher Archive Research Project (NITARP) and was funded by NASA Astrophysics Data Program and Archive Outreach funds. Our education results are described in a companion education poster, Bonadurer et al.

  6. Optical durability testing of candidate solar mirrors

    SciTech Connect

    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.

  7. New candidate supernova remnants in nearby galaxies

    NASA Astrophysics Data System (ADS)

    Kopsacheili, Maria; Boumis, Panos; Leonidaki, Ioanna; Zezas, Andreas

    2016-06-01

    Supernova remnants (SNRs) are objects of high importance since they provide major amounts of energy to the interstellar medium (ISM), while at the same time, they depict the end-point state of massive stars (M > 8 Mo). In order to investigate the physical properties of these objects and their interplay with their environment, we have embarked in an extensive investigation of the SNR populations in nearby galaxies of different morphological types. This effort has been initiated with six galaxies, mostly irregulars,in the northern hemisphere (Leonidaki et al. 2010, 2013). Following this context, we present new candidate SNRs (down to fluxes of 10^{-16} erg sec^{-1} cm^-2) of five spiral galaxies in the southern hemisphere (NGC 45, NGC 55, NGC 1313, NGC 1672, NGC 7793), based on deep narrow-band Hα and [S II] images observed with the 4m Blanco telescope at CTIO, Chile. The new detections were achieved by calculating the [S II]/Hα flux ratio, where all sources with [S II]/ Hα > 0.4 were considered as candidate SNRs. Furthermore, we use the derived properties of the newly detected candidate SNRs ([S II]/Hα ratios, Hα fluxes) to investigate how they are distributed according to their brightness and their behavior in different environments (irregulars vs. spirals).

  8. UNCOVERING THE NUCLEUS CANDIDATE FOR NGC 253

    SciTech Connect

    Günthardt, G. I.; Camperi, J. A.; Agüero, M. P.; Díaz, R. J.; Gomez, P. L.; Schirmer, M.; Bosch, G. E-mail: camperi@oac.uncor.edu E-mail: rdiaz@gemini.edu E-mail: mschirmer@gemini.edu

    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

  9. Uncovering the Nucleus Candidate for NGC 253

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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 H2 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

  10. Probing the space-time geometry around black hole candidates with the resonance models for high-frequency QPOs and comparison with the continuum-fitting method

    SciTech Connect

    Bambi, Cosimo

    2012-09-01

    Astrophysical black hole candidates are thought to be the Kerr black hole predicted by General Relativity. However, in order to confirm the Kerr-nature of these objects, we need to probe the geometry of the space-time around them and check that observations are consistent with the predictions of the Kerr metric. That can be achieved, for instance, by studying the properties of the electromagnetic radiation emitted by the gas in the accretion disk. The high-frequency quasi-periodic oscillations observed in the X-ray flux of some stellar-mass black hole candidates might do the job. As the frequencies of these oscillations depend only very weakly on the observed X-ray flux, it is thought they are mainly determined by the metric of the space-time. In this paper, I consider the resonance models proposed by Abramowicz and Kluzniak and I extend previous results to the case of non-Kerr space-times. The emerging picture is more complicated than the one around a Kerr black hole and there is a larger number of possible combinations between different modes. I then compare the bounds inferred from the twin peak high-frequency quasi-periodic oscillations observed in three micro-quasars (GRO J1655-40, XTE J1550-564, and GRS 1915+105) with the measurements from the continuum-fitting method of the same objects. For Kerr black holes, the two approaches do not provide consistent results. In a non-Kerr geometry, this conflict may be solved if the observed quasi-periodic oscillations are produced by the resonance ν{sub θ}:ν{sub r} = 3:1, where ν{sub θ} and ν{sub r} are the two epicyclic frequencies. It is at least worth mentioning that the deformation from the Kerr solution required by observations would be consistent with the one suggested in another recent work discussing the possibility that steady jets are powered by the spin of these compact objects.

  11. ARIEL: an ESA M4 mission candidate

    NASA Astrophysics Data System (ADS)

    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.

  12. Recruiting as much about families as candidate

    SciTech Connect

    Madison, Alison L.

    2011-06-05

    Monthly economic diversity column for Tri-City Herald: For businesses large and small, one of the biggest challenges to staying afloat and achieving growth is attracting and retaining key talent. And in an area such as the Tri-Cities, where many of our skilled professionals are geographical transplants and the technology-based economic growth we seek often requires highly specific skill sets, effective recruiting is especially critical. But it isn’t just about matching candidates with open positions and signing on the dotted line. In fact, members of the Three Rivers Entrepreneur Network were reminded at a recent presentation that recruiting is very much about attracting the family unit.

  13. New optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Henze, M.; Rodriguez, J.; Haswell, C. A.; Holmes, S.; Kolb, U.; Lucas, R.

    2010-06-01

    We report the discovery of a possible nova in M 31 on a 5x120s stacked unfiltered CCD image obtained with the 0.35-m f/11 OU/OAM PIRATE Schmidt-Cassegrain telescope (+ SBIG STL-1001E CCD camera) at Costitx, Mallorca, Spain on 2010 June 26.084 UT with a corresponding R magnitude of 17.8. The position for the nova candidate is RA = 00h44m04.48s, Dec = +41d28'34.2" (J2000, accuracy of 0.3"), which is 902" east and 746" north of the core of M 31.

  14. New nova candidate in M81

    NASA Astrophysics Data System (ADS)

    Henze, M.; Sala, G.; Jose, J.; Figueira, J.; Hernanz, M.

    2016-06-01

    We report the discovery of a new nova candidate in the M81 galaxy on 16x200s stacked R filter CCD images, obtained with the 80 cm Ritchey-Chretien F/9.6 Joan Oro telescope at Observatori Astronomic del Montsec, owned by the Catalan Government and operated by the Institut d'Estudis Espacials de Catalunya, Spain, using a Finger Lakes PL4240-1-BI CCD Camera (with a Class 1 Basic Broadband coated 2k x 2k chip with 13.5 microns sq. pixels).

  15. Chaotic and stochastic processes in the accretion flows of the black hole X-ray binaries revealed by recurrence analysis

    NASA Astrophysics Data System (ADS)

    Suková, Petra; Grzedzielski, Mikolaj; Janiuk, Agnieszka

    2016-02-01

    variability in the microquasars GRS 1915+105 and IGR J17091-3624. Furthermore, we also find significant traces of nonlinear dynamics in three other sources: GX 339-4, XTE J1550-564 and GRO J1655-40, particularly in the disk-dominated soft state, as well as in the intermediate states at the rising and declining phase of the outburst. Only for the source XTE J1650-500 no observation with such variability pattern was found. This is possibly due to the global accretion rate in this source being too small for the limit-cycle instability to develop.

  16. 11 CFR 103.4 - Vice Presidential candidate campaign depositories.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... designated by the principal campaign committee of a political party's candidate for President shall be the campaign depository for that political party's candidate for the office of Vice President....

  17. 11 CFR 103.4 - Vice Presidential candidate campaign depositories.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... designated by the principal campaign committee of a political party's candidate for President shall be the campaign depository for that political party's candidate for the office of Vice President....

  18. 11 CFR 103.4 - Vice Presidential candidate campaign depositories.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... designated by the principal campaign committee of a political party's candidate for President shall be the campaign depository for that political party's candidate for the office of Vice President....

  19. 11 CFR 103.4 - Vice Presidential candidate campaign depositories.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... designated by the principal campaign committee of a political party's candidate for President shall be the campaign depository for that political party's candidate for the office of Vice President....

  20. 11 CFR 103.4 - Vice Presidential candidate campaign depositories.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... designated by the principal campaign committee of a political party's candidate for President shall be the campaign depository for that political party's candidate for the office of Vice President....

  1. Official portrait of astronaut candidate Kenneth D. Cockrell

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Official portrait of astronaut candidate Kenneth D. Cockrell, a member of Astronaut Class 13 (1990) and a space shuttle pilot candidate. Cockrell wears a navy blue flight suit and holds space shuttle model.

  2. New brown dwarf candidates in the Pleiades

    NASA Astrophysics Data System (ADS)

    Eisenbeiss, T.; Moualla, M.; Mugrauer, M.; Schmidt, T. O. B.; Raetz, St.; Neuhäuser, R.; Ginski, Ch.; Hohle, M. M.; Koeltzsch, A.; Marka, C.; Rammo, W.; Reithe, A.; Roell, T.; Vaňko, M.

    2009-05-01

    We have performed deep, wide-field imaging on a ˜ 0.4 deg2 field in the Pleiades (Melotte 22). The selected field was not yet target of a deep search for low mass stars and brown dwarfs. Our limiting magnitudes are R˜22 mag and I˜20 mag, sufficient to detect brown dwarf candidates down to 40 MJ. We found 197 objects, whose location in the (I, R-I) color magnitude diagram is consistent with the age and the distance of the Pleiades. Using CTK R and I as well as JHK photometry from our data and the 2MASS survey we were able to identify 7 new brown dwarf candidates. We present our data reduction technique, which enables us to resample, calibrate, and co-add many images by just two steps. We estimate the interstellar extinction and the spectral type from our optical and the NIR data using a two-dimensional χ2 fitting. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich- Schiller-University. Table A3 is available at the CDS via http://cdsarc.u-strasbg.fr/pub/cats/J/AN/330/439

  3. Candidate chemosensory cells in the porcine stomach.

    PubMed

    Widmayer, Patricia; Breer, Heinz; Hass, Nicole

    2011-07-01

    A continuous chemosensory monitoring of the ingested food is of vital importance for adjusting digestive processes according to diet composition. Although any dysfunction of this surveillance system may be the cause of severe gastrointestinal disorders, information about the cellular and molecular basis of chemosensation in the gastrointestinal tract is limited. The porcine alimentary canal is considered as an appropriate model for the human gastrointestinal tract. Therefore, in this study we have investigated the gastric mucosa of swine for cells which express gustatory transduction elements such as TRPM5 or PLCβ2, and thus may represent candidate "chemosensors". It was found that the porcine stomach indeed contains cells expressing gustatory marker molecules; however, the morphology and topographic distribution of putative chemosensory cells varied significantly from that in mice. Whereas in the murine stomach these cells were clustered at a distinct region near the gastric entrance, no such compact cell cluster was found in the pig stomach. These results indicate substantial differences regarding the phenotype of candidate chemosensory cells of mice and swine and underline the importance of choosing the most suitable model organisms. PMID:21667283

  4. Pulsar candidates towards Fermi unassociated sources

    NASA Astrophysics Data System (ADS)

    Frail, D. A.; Mooley, K. P.; Jagannathan, P.; Intema, H. T.

    2016-09-01

    We report on a search for steep spectrum radio sources within the 95 per cent confidence error ellipses of the Fermi unassociated sources from the Large Area Telescope (LAT). Using existing catalogues and the newly released Giant Metrewave Radio Telescope 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 towards 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 radio periodicity searches at the positions of the steep spectrum radio sources may reveal pulsations.

  5. MICROLENSING BINARIES WITH CANDIDATE BROWN DWARF COMPANIONS

    SciTech Connect

    Shin, I.-G.; Han, C.; Gould, A.; Skowron, J.; Udalski, A.; Szymanski, M. K.; Kubiak, M.; Soszynski, I.; Pietrzynski, G.; Poleski, R.; Ulaczyk, K.; Pietrukowicz, P.; Kozlowski, S.; Wyrzykowski, L.; Sumi, T.; Dominik, M.; Beaulieu, J.-P.; Tsapras, Y.; Bozza, V.; Abe, F.; Collaboration: OGLE Collaboration; MOA Collaboration; muFUN Collaboration; and others

    2012-12-01

    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 events discovered during the 2004-2011 observation seasons. Based on the low mass ratio criterion of q < 0.2, we found seven candidate events: OGLE-2004-BLG-035, OGLE-2004-BLG-039, OGLE-2007-BLG-006, OGLE-2007-BLG-399/MOA-2007-BLG-334, MOA-2011-BLG-104/OGLE-2011-BLG-0172, MOA-2011-BLG-149, and MOA-201-BLG-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured masses of the brown dwarf companions are 0.02 {+-} 0.01 M {sub Sun} and 0.019 {+-} 0.002 M {sub Sun} 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 with well-covered light curves increases with new-generation searches.

  6. Elemental abundances of solar sibling candidates

    SciTech Connect

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

  7. Surgical evaluation of candidates for cochlear implants

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Lilly, D. J.; Fowler, L. P.; Stypulkowski, P. H.

    1987-01-01

    The customary presentation of surgical procedures to patients in the United States consists of discussions on alternative treatment methods, risks of the procedure(s) under consideration, and potential benefits for the patient. Because the contents of the normal speech signal have not been defined in a way that permits a surgeon systematically to provide alternative auditory signals to a deaf patient, the burden is placed on the surgeon to make an arbitrary selection of candidates and available devices for cochlear prosthetic implantation. In an attempt to obtain some information regarding the ability of a deaf patient to use electrical signals to detect and understand speech, the Good Samaritan Hospital and Neurological Sciences Institute cochlear implant team has routinely performed tympanotomies using local anesthesia and has positioned temporary electrodes onto the round windows of implant candidates. The purpose of this paper is to review our experience with this procedure and to provide some observations that may be useful in a comprehensive preoperative evaluation for totally deaf patients who are being considered for cochlear implantation.

  8. Advanced vaccine candidates for Lassa fever.

    PubMed

    Lukashevich, Igor S

    2012-11-01

    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.

  9. Some Candidates for Solar Gravity Modes

    NASA Astrophysics Data System (ADS)

    Thomson, David J.

    2015-04-01

    Since the accidental discovery of solar modes in space (Thomson,Maclennan, and Lanzerotti, Nature, 1995) work has continued and there are now a few candidates for identified solar gravity modes using charged particles and interplanetary magnetic field data. Contrary to initial expectations, there is a preference for higher-l modes, typically l = 2 to 5.Second, different frequencies are expected at ACE (at L1) and Ulysses, in an almost sidereal solar-polar orbit. Given a candidate detection at ACE where signal-to-noise ratios are higher, one can then shift frequencies by ±32m nHz and test for agreement at Ulysses.Third, the 7.5 degree inclination of the ecliptic on the solar equator splits odd-parity modes at ACE by32 nHz. The two sub-singlets have a defined phase relation that can be used as a further check on parity. Two such modes are G2,-1 at 296.195 uHz and G3,-2 at 296.887 uHz. Both have all 2l+1 singlets detected on both ACE and Ulysses.The 11 singlets of the G5,-1 mode are also all detected above the 99% level. The mode has a center frequency of 383.812 uHz with a1 ≈ 918 nHz.

  10. Vaccine candidates for leishmaniasis: a review.

    PubMed

    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.

  11. Changing Perceptions of Teacher Candidates in High-Needs Schools

    ERIC Educational Resources Information Center

    DeJarnette, Nancy K.

    2016-01-01

    Candidates enter teacher education programs with established beliefs about diversity and urban education. These belief systems impact decisions that teacher candidates make both now and in the future. Providing opportunities for candidates to spend quality time in an urban Professional Development School (PDS) setting with the support and guidance…

  12. Opinions of the Geography Teacher Candidates toward Mind Maps

    ERIC Educational Resources Information Center

    Seyihoglu, Aysegul

    2013-01-01

    The purpose of this study is to reveal the opinions of the teacher candidates about mind mapping technique used in Geography education of undergraduate program. In this study, the qualitative research techniques were used. The study group consists of 55 teacher candidates. The teacher candidates have been asked for their opinions about the process…

  13. Parliamentary Privilege--The Candidates. Research Brief. Edition 3

    ERIC Educational Resources Information Center

    Sutton Trust, 2015

    2015-01-01

    The research brief, "Parliamentary Privilege", looks at the educational backgrounds of candidates in winnable seats. The study included candidates selected by mid-December 2014 who were replacing serving MPs for the same party or in target seats with a reasonable possibility of winning. More than half of the candidates attended Russell…

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  16. 11 CFR 9033.1 - Candidate and committee agreements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... authorized committee(s) will comply with the conditions set forth in 11 CFR 9033.1(b). The candidate may... qualified campaign expenses as defined at 11 CFR 9032.9. (2) The candidate and the candidate's authorized committee(s) will comply with the documentation requirements set forth in 11 CFR 9033.11. (3) The...

  17. 14 CFR 1214.1106 - Selection of astronaut candidates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Selection of astronaut candidates. 1214.1106 Section 1214.1106 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1106 Selection of astronaut candidates....

  18. 15 CFR 922.21 - Selection of active candidates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Selection of active candidates. 922.21... Selection of active candidates. (a) The Secretary shall, from time to time, select a limited number of sites from the SEL for Active Candidate consideration based on a preliminary assessment of the...

  19. 15 CFR 922.21 - Selection of active candidates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 3 2011-01-01 2011-01-01 false Selection of active candidates. 922.21... Selection of active candidates. (a) The Secretary shall, from time to time, select a limited number of sites from the SEL for Active Candidate consideration based on a preliminary assessment of the...

  20. 15 CFR 922.21 - Selection of active candidates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Selection of active candidates. 922.21... Selection of active candidates. (a) The Secretary shall, from time to time, select a limited number of sites from the SEL for Active Candidate consideration based on a preliminary assessment of the...

  1. 15 CFR 922.21 - Selection of active candidates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Selection of active candidates. 922.21... Selection of active candidates. (a) The Secretary shall, from time to time, select a limited number of sites from the SEL for Active Candidate consideration based on a preliminary assessment of the...

  2. 15 CFR 922.21 - Selection of active candidates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Selection of active candidates. 922.21... Selection of active candidates. (a) The Secretary shall, from time to time, select a limited number of sites from the SEL for Active Candidate consideration based on a preliminary assessment of the...

  3. Cognitive Styles in Admission Procedures for Assessing Candidates of Architecture

    ERIC Educational Resources Information Center

    Casakin, Hernan; Gigi, Ariela

    2016-01-01

    Cognitive style has a strong predictive power in academic and professional success. This study investigated the cognitive profile of candidates studying architecture. Specifically, it explored the relation between visual and verbal cognitive styles, and the performance of candidates in admission procedures. The cognitive styles of candidates who…

  4. Identity Functions and Empathetic Tendencies of Teacher Candidates

    ERIC Educational Resources Information Center

    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…

  5. Concerns of Teacher Candidates in an Early Field Experience

    ERIC Educational Resources Information Center

    Chang, Sau Hou

    2009-01-01

    The present study examined the concerns of teacher candidates in an early field experience. Thirty-five teacher candidates completed the Teacher Concerns Checklist (TCC, Fuller & Borich, 2000) at the beginning, middle and end of their early field experiences. Results showed that teacher candidates ranked impact as the highest concern, self as the…

  6. Perceptions of Candidate Teachers about Concept of the Project

    ERIC Educational Resources Information Center

    Tortop, Hasan Said

    2014-01-01

    The aim of study is to investigate candidate teachers' metaphors about project concept in Turkey. Study group of research is 171 candidate teachers enrolled 2011-2012 educational terms one of the faculty of education in Turkey. Data was obtained from the candidate teachers' completion of the sentence "Project is like ..., because ...".…

  7. Image of Ideal Teachers among Turkish Young Teacher Candidates

    ERIC Educational Resources Information Center

    Budak, Yusuf

    2011-01-01

    The aim of the current study is to determine the perception of teacher candidates concerning ideal teachers and to determine the perception of qualitative teachers that teacher candidates have and put a light on the selection of teacher candidates and the development of teacher-training programs. In the study, quantitative and qualitative…

  8. 11 CFR 9033.1 - Candidate and committee agreements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) that meet the requirements of 11 CFR 9033.12(b). Upon request, documentation explaining the computer... authorized committee(s) will comply with the conditions set forth in 11 CFR 9033.1(b). The candidate may... qualified campaign expenses as defined at 11 CFR 9032.9. (2) The candidate and the candidate's...

  9. 11 CFR 106.1 - Allocation of expenses between candidates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... behalf of more than one clearly identified Federal candidate shall be reported pursuant to 11 CFR 104.10... more than one clearly identified Federal candidate shall be attributed to each such candidate according... fundraising program or event where funds are collected by one committee for more than one clearly...

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

    ERIC Educational Resources Information Center

    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…

  11. The Marketing Market: Matching Academic Hiring Institutions and Job Candidates

    ERIC Educational Resources Information Center

    Basil, Michael D.; Basil, Debra Z.

    2008-01-01

    Hiring faculty is a challenge in the field of marketing. One important factor is a shortage of candidates. The problem is exacerbated, however, by an imperfect match between jobs and candidates. This study examines the homogeneity of academic jobs and candidates. Surveys were conducted with both parties. The results show that institutions and…

  12. Production of EV71 vaccine candidates.

    PubMed

    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

  13. Using a New Crustal Thickness Model to Test Previous Candidate Lunar Basins and to Search for New Candidates

    NASA Technical Reports Server (NTRS)

    Meyer, H. M.; Frey, H. V.

    2012-01-01

    A new crustal thickness model was used to test the viability of 110 candidate large lunar basins previously identified using older topographic and crustal thickness data as well as photogeologic data. The new model was also used to search for new candidate lunar basins greater than 300 km in diameter. We eliminated 11 of 27 candidates previously identified in the older crustal thickness model, and found strong evidence for at least 8 new candidates.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Computational assessment of organic photovoltaic candidate compounds

    NASA Astrophysics Data System (ADS)

    Borunda, Mario; Dai, Shuo; Olivares-Amaya, Roberto; Amador-Bedolla, Carlos; Aspuru-Guzik, Alan

    2015-03-01

    Organic photovoltaic (OPV) cells are emerging as a possible renewable alternative to petroleum based resources and are needed to meet our growing demand for energy. Although not as efficient as silicon based cells, OPV cells have as an advantage that their manufacturing cost is potentially lower. The Harvard Clean Energy Project, using a cheminformatic approach of pattern recognition and machine learning strategies, has ranked a molecular library of more than 2.6 million candidate compounds based on their performance as possible OPV materials. Here, we present a ranking of the top 1000 molecules for use as photovoltaic materials based on their optical absorption properties obtained via time-dependent density functional theory. This computational search has revealed the molecular motifs shared by the set of most promising molecules.

  16. A family of WISPy dark matter candidates

    NASA Astrophysics Data System (ADS)

    Jaeckel, Joerg

    2014-05-01

    Dark matter made from non-thermally produced bosons can have very low, possibly sub-eV masses. Axions and hidden photons are prominent examples of such "dark" very weakly interacting light (slim) particles (WISPs). A suitable mechanism for their non-thermal production is the misalignment mechanism. Their dominant interaction with Standard Model (SM) particles is via photons. In this note we want to go beyond these standard examples and discuss a wide range of scalar and pseudo-scalar bosons interacting with SM matter fermions via derivative interactions. Suitably light candidates arise naturally as pseudo-Nambu-Goldstone bosons. In particular we are interested in examples, inspired by familons, whose interactions have a non-trivial flavor structure.

  17. Assessment of Live Plague Vaccine Candidates.

    PubMed

    Feodorova, Valentina A; Sayapina, Lidiya V; Motin, Vladimir L

    2016-01-01

    Since its creation in the early twentieth century, live plague vaccine EV has been successfully applied to millions of people without severe complications. This vaccine has been proven to elicit protection against both bubonic and pneumonic plague, and it is still in use in populations at risk mainly in the countries of the former Soviet Union. Despite extensive efforts in developing subunit vaccines, there is a reviving interest in creation of a precisely attenuated strain of Yersinia pestis superior to the EV that can serve as a live plague vaccine with improved characteristics. Here we summarize decades of experience of the Russian anti-plague research in developing a standard protocol for early-stage evaluation of safety and immunogenicity of live plague vaccines. This protocol allows step-by-step comparison of the novel test candidates with the EV vaccine by using subcutaneous immunization and bubonic plague infection models in two animal species, e.g., guinea pigs and mice. PMID:27076149

  18. Ocriplasmin: who is the best candidate?

    PubMed Central

    Prospero Ponce, Claudia M; Stevenson, William; Gelman, Rachel; Agarwal, Daniel R; Christoforidis, John B

    2016-01-01

    Enzymatic vitreolysis is currently the focus of attention around the world for treating vitreomacular traction and full-thickness macular hole. Induction of posterior vitreous detachment is an active area of developmental clinical and basic research. Despite exerting an incompletely elucidated physiological effect, ocriplasmin (also known as microplasmin) has been recognized to serve as a well-tolerated intravitreal injection for the treatment of vitreomacular traction and full-thickness macular hole. There are several unexplored areas of intervention where enzymatic vitreolysis could potentially be used (ie, diabetic macular edema). Recent promising studies have included combinations of enzymatic approaches and new synthetic molecules that induce complete posterior vitreous detachment as well as antiangiogenesis. Although no guidelines have been proposed for the use of ocriplasmin, this review attempts to aid physicians in answering the most important question, “Who is the best candidate?” PMID:27051270

  19. Chiron stellar occultation candidates: 1993-1996

    NASA Technical Reports Server (NTRS)

    Bus, S. J.; Wasserman, L. H.; Elliot, J. L.

    1994-01-01

    A photographic search was conducted for stars that may be occulted by the unusual solar system object (2060) Chiron during the period from fall 1993 through summer 1996. 44 candidates were identified to a limiting V magnitude of 16, and for which the minimum appulse separation with Chiron is predicted to be less than 2.5 arcsec. The successful observation of a stellar occultation by Chiron would give a direct measure of its diameter (currently estimated to be between 60 and 300 km), and would help considerably in constraining Chiron's surface properties and volatile makeup. If at the time of the occultation, Chiron exhibits a significant coma, there is also the potential for measuring the optical-depth profile of the dust in its inner coma.

  20. Chandra Pilot Survey of Extrasolar Planet Candidates

    NASA Astrophysics Data System (ADS)

    Tsuboi, Yohko

    2012-09-01

    We propose to detect planetary-mass companion around young nearby stars by X-ray direct imaging observations with Chandra. Our goals are to determine I. if the X-ray band can be a new probe to the exo-planet search, and II. if a planet emit detectable X-rays with a magnetic origin at a young age. This should be a challenging observation but a brand-new discovery space unique to Chandra. The abundant population of YSOs in the same field of view will enable us to obtain complete X-ray catalogues of YSOs with all categories of masses. We will also execute simultaneous deep NIR observations with IRSF/SIRIUS and Nishiharima 2m telescope to search for the other X-ray-emitting very low-mass objects near our aiming planet candidates.

  1. Arrest and incarceration of civil commitment candidates.

    PubMed

    Hiday, V A

    1991-07-01

    To gauge whether more stringent civil commitment criteria have led to the criminalization of mentally ill persons, forcing them into jails and prisons instead of treating them, a statewide sample of 1,226 civil commitment candidates in North Carolina was tracked for six months after their commitment hearings. Only 72 sample members were arrested during the period, mostly for burglary or larceny (22 arrests), simple or aggravated assault (17 arrests), and minor offenses (40 arrests), including drunkenness, trespassing, and traffic violations. Fourteen sample members were jailed, and two were sent to prison. The mentally ill who were not involuntarily hospitalized or who were hospitalized for only short periods were seldom arrested; when they were arrested, the charges were generally for nondangerous offenses.

  2. Assessment of Live Plague Vaccine Candidates.

    PubMed

    Feodorova, Valentina A; Sayapina, Lidiya V; Motin, Vladimir L

    2016-01-01

    Since its creation in the early twentieth century, live plague vaccine EV has been successfully applied to millions of people without severe complications. This vaccine has been proven to elicit protection against both bubonic and pneumonic plague, and it is still in use in populations at risk mainly in the countries of the former Soviet Union. Despite extensive efforts in developing subunit vaccines, there is a reviving interest in creation of a precisely attenuated strain of Yersinia pestis superior to the EV that can serve as a live plague vaccine with improved characteristics. Here we summarize decades of experience of the Russian anti-plague research in developing a standard protocol for early-stage evaluation of safety and immunogenicity of live plague vaccines. This protocol allows step-by-step comparison of the novel test candidates with the EV vaccine by using subcutaneous immunization and bubonic plague infection models in two animal species, e.g., guinea pigs and mice.

  3. Triton stellar occultation candidates: 1995-1999

    NASA Technical Reports Server (NTRS)

    Mcdonald, S. W.; Elliot, J. L.

    1995-01-01

    We have completed a search for candidates for stellar occultations by Triton over the years 1995-1999. CCd strip scan images provided star positions in the relevant sky area to a depth of about 17.5 R magnitude. Over this time period, we find that Triton passes within 1.0 arcsec of 75 stars. Appulses with geocentric minimum separations of less than 0.35 arcsec will result in stellar occultations, but further astrometry and photometry is necessary to refine individual predictions for identification of actual occultations. Finder charts are included to aid in further studies and prediction refinement. The two most promising potential occultations, Tr176 and Tr180, occur in 1997.

  4. Mining biological databases for candidate disease genes

    NASA Astrophysics Data System (ADS)

    Braun, Terry A.; Scheetz, Todd; Webster, Gregg L.; Casavant, Thomas L.

    2001-07-01

    The publicly-funded effort to sequence the complete nucleotide sequence of the human genome, the Human Genome Project (HGP), has currently produced more than 93% of the 3 billion nucleotides of the human genome into a preliminary `draft' format. In addition, several valuable sources of information have been developed as direct and indirect results of the HGP. These include the sequencing of model organisms (rat, mouse, fly, and others), gene discovery projects (ESTs and full-length), and new technologies such as expression analysis and resources (micro-arrays or gene chips). These resources are invaluable for the researchers identifying the functional genes of the genome that transcribe and translate into the transcriptome and proteome, both of which potentially contain orders of magnitude more complexity than the genome itself. Preliminary analyses of this data identified approximately 30,000 - 40,000 human `genes.' However, the bulk of the effort still remains -- to identify the functional and structural elements contained within the transcriptome and proteome, and to associate function in the transcriptome and proteome to genes. A fortuitous consequence of the HGP is the existence of hundreds of databases containing biological information that may contain relevant data pertaining to the identification of disease-causing genes. The task of mining these databases for information on candidate genes is a commercial application of enormous potential. We are developing a system to acquire and mine data from specific databases to aid our efforts to identify disease genes. A high speed cluster of Linux of workstations is used to analyze sequence and perform distributed sequence alignments as part of our data mining and processing. This system has been used to mine GeneMap99 sequences within specific genomic intervals to identify potential candidate disease genes associated with Bardet-Biedle Syndrome (BBS).

  5. Walking Capacity of Bariatric Surgery Candidates

    PubMed Central

    King, WC; Engel, SG; Elder, KA; Chapman, WH; Eid, GM; Wolfe, BM; Belle, SH

    2011-01-01

    Background This study characterizes the walking limitations of bariatric surgery candidates by age and body mass index (BMI) and determines factors independently associated with walking capacity. Setting Multi-institutional at research university hospitals in the United States. Methods 2458 participants of the Longitudinal Assessment of Bariatric Surgery study (age: 18-78 y, BMI: 33-94 kg/m2) attended a pre-operative research visit. Walking capacity was measured via self-report and the 400 meter Long Distance Corridor Walk (LDCW). Results Almost two-thirds (64%) of subjects reported limitations walking several blocks, 48% had an objectively-defined mobility deficit, and 16% reported at least some walking aid use. In multivariable analysis, BMI, older age, lower income and greater bodily pain were independently associated (p<.05) with walking aid use, physical discomfort during the LDCW, inability to complete the LDCW, and slower time to complete the LDCW. Female sex, Hispanic ethnicity (but not race), higher resting heart rate, history of smoking, several comoribidities (history of stroke, ischemic heart disease, diabetes, asthma, sleep apnea, venous edema with ulcerations), and depressive symptoms were also independently related (p<.05) to at least one measure of reduced walking capacity. Conclusions Walking limitations are common in bariatric surgery candidates, even among the least severely obese and youngest patients. Physical activity counseling must be tailored to individuals' abilities. While several factors identified in this study (e.g., BMI, age, pain, comorbidities) should be considered, directly assessing walking capacity will facilitate appropriate goal-setting. PMID:21937285

  6. CRISPLD2: a novel NSCLP candidate gene

    PubMed Central

    Chiquet, Brett T.; Lidral, Andrew C.; Stal, Samuel; Mulliken, John B.; Moreno, Lina M.; Arco-Burgos, Mauricio; Valencia-Ramirez, Consuelo; Blanton, Susan H.; Hecht, Jacqueline T.

    2013-01-01

    Non-syndromic cleft lip with or without cleft palate (NSCLP) results from the complex interaction between genes and environmental factors. Candidate gene analysis and genome scans have been employed to identify the genes contributing to NSCLP. In this study, we evaluated the 16q24.1 chromosomal region, which has been identified by multiple genome scans as an NSCLP region of interest. Two candidate genes were found in the region: interferon regulatory factor 8 (IRF8) and cysteine-rich secretory protein LCCL domain containing 2 (CRISPLD2). Initially, Caucasian and Hispanic NSCLP multiplex families and simplex parent–child trios were genotyped for single nucleotide polymorphisms (SNPs) in both IRF8 and CRISPLD2. CRISPLD2 was subsequently genotyped in a data set comprised of NSCLP families from Colombia, South America. Linkage disequilibrium analysis identified a significant association between CRISPLD2 and NSCLP in both our Caucasian and Hispanic NSCLP cohorts. SNP rs1546124 and haplotypes between rs1546124 and either rs4783099 or rs16974880 were significant in the Caucasian multiplex population (P = 0.01, P = 0.002 and P = 0.001, respectively). An altered transmission of CRISPLD2 SNPs rs8061351 (P = 0.02) and rs2326398 (P = 0.06) was detected in the Hispanic population. No association was found between CRISPLD2 and our Colombian population or IRF8 and NSCLP. In situ hybridization showed that CRISPLD2 is expressed in the mandible, palate and nasopharynx regions during craniofacial development at E13.5–E17.5, respectively. Altogether, these data suggest that genetic variation in CRISPLD2 has a role in the etiology of NSCLP. PMID:17616516

  7. An evaluation of candidate oxidation resistant materials

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon; Banks, Bruce; Mirtich, Michael; Difilippo, Frank; Hotes, Deborah; Labed, Richard; Dever, Terese; Kussmaul, Michael

    1987-01-01

    Ground based testing of materials considered for Kapton solar array blanket protection, graphite epoxy structural member protection, and high temperature radiators was performed in an RF plasma asher. Ashing rates for Kapton were correlated with rates measured on STS-8 to determine the exposure time equivalent to one year in low Earth orbit (LEO) at a constant density space station orbital flux. Protective coatings on Kapton from Tekmat, Andus Corporation, and LeRC were evaluated in the plasma asher and mass loss rates per unit area were measured for each sample. All samples evaluated provided some protection to the underlying surface but ion beam sputter deposited samples of SiO2 and SiO2 with 8% polytetrafluoroethylene (PTFE) showed no evidence of degradation after 47 hours of exposure. Mica paint was evaluated as a protective coating for graphite epoxy structural members. Mica appears to be resistant to attack by atomic oxygen but only offers some limited protection as a paint because the paint vehicles evaluated to date were not resistant to atomic oxygen. Four materials were selected for evaluation as candidate radiator materials: stainless steel, copper, niobium-1% zirconium, and titanium-6% aluminum-4% vanadium. These materials were surface textured by various means to improve their emittance. Emittances as high as 0.93 at 2.5 microns for stainless steel and 0.89 at 2.5 microns for Nb-1 Zr were obtained from surface texturing. There were no significant changes in emittance after asher exposure.

  8. Galactic worms. I - Catalog of worm candidates

    NASA Technical Reports Server (NTRS)

    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.

  9. Comet candidates among quasi-Hilda objects

    NASA Astrophysics Data System (ADS)

    Gil-Hutton, R.; García-Migani, E.

    2016-05-01

    Aims: We present the results of a search for quasi-Hilda comets. We wanted to find objects that have recently arrived from the Centaur zone that could became active near the perihelion of their orbits. Methods: Two hundred and seventy-seven objects from the ASTORB database were selected following a dynamical criteria to constrain the unstable quasi-Hilda region. These objects were integrated backward 50 000 yr in order to identify those that have recently arrived from the outer regions of the solar system. Results: The backward integration showed that 11 objects could be Centaurs or transneptunian objects that ended their dynamical evolution as quasi-Hilda comets. The dynamical evolution of these objects from a statistical point of view was studied by computing the time-averaged distribution of a number of clones as a function of the aphelion and perihelion distances. All the candidates show a dynamical behavior that is expected for comets injected in the inner solar system from the Centaur or transneptunian regions and reaching the quasi-Hilda region.

  10. IBD Candidate Genes and Intestinal Barrier Regulation

    PubMed Central

    McCole, Declan F.

    2015-01-01

    Technological advances in the large scale analysis of human genetics have generated profound insights into possible genetic contributions to chronic diseases including the inflammatory bowel diseases (IBDs), Crohn’s disease and ulcerative colitis. To date, 163 distinct genetic risk loci have been associated with either Crohn’s disease or ulcerative colitis, with a substantial degree of genetic overlap between these 2 conditions. Although many risk variants show a reproducible correlation with disease, individual gene associations only affect a subset of patients, and the functional contribution(s) of these risk variants to the onset of IBD is largely undetermined. Although studies in twins have demonstrated that the development of IBD is not mediated solely by genetic risk, it is nevertheless important to elucidate the functional consequences of risk variants for gene function in relevant cell types known to regulate key physiological processes that are compromised in IBD. This article will discuss IBD candidate genes that are known to be, or are suspected of being, involved in regulating the intestinal epithelial barrier and several of the physiological processes presided over by this dynamic and versatile layer of cells. This will include assembly and regulation of tight junctions, cell adhesion and polarity, mucus and glycoprotein regulation, bacterial sensing, membrane transport, epithelial differentiation, and restitution. PMID:25215613

  11. Ailing voters advance attractive congressional candidates.

    PubMed

    Zebrowitz, Leslie A; Franklin, Robert G; Palumbo, Rocco

    2015-01-01

    Among many benefits of facial attractiveness, there is evidence that more attractive politicians are more likely to be elected. Recent research found this effect to be most pronounced in congressional districts with high disease threat-a result attributed to an adaptive disease avoidance mechanism, whereby the association of low attractiveness with poor health is particularly worrisome to voters who feel vulnerable to disease. We provided a more direct test of this explanation by examining the effects of individuals' own health and age. Supporting a disease avoidance mechanism, less healthy participants showed a stronger preference for more attractive contenders in U.S. Senate races than their healthier peers, and this effect was stronger for older participants, who were generally less healthy than younger participants. Stronger effects of health for older participants partly reflected the absence of positive bias toward attractive candidates among the healthiest, suggesting that healthy older adults may be unconcerned about disease threat or sufficiently wise to ignore attractiveness. PMID:25562113

  12. Candidate industrial preparedness program. Final report

    SciTech Connect

    Cannell, R.; Schuert, E.

    1980-12-01

    Research in the area of industrial preparedness was most active in the 1960s when numerous studies were completed on subjects directly related to the survival of industry during a nuclear war. However, during this period no national policy evolved on the role industry should play nor were the requirements for a comprehensive industrial preparedness program developed. Industrial preparedness can be implemented either during peaceful times, or during a period of crisis at which time a nuclear attack appears to be imminent. The selected program should consist of those components necessary for survival of the population during the early post-attack period and for augmentation during the period of national recovery. In order to establish the requirements of industry in the post-attack environment it was necessary to estimate the condition of the country after a large-scale nuclear exchange, especially the relationship between the surviving population and the capacity of the residual industry to produce goods. Thus those industries essential to national survival and eventual recovery were evaluated with respect to their capability to provide products. Where the capability was insufficient to support the post-attack population, those industries became prime candidates for assistance through an industrial preparedness program.

  13. Virus-like particles as nanovaccine candidates

    NASA Astrophysics Data System (ADS)

    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.

  14. The FK Comae candidate UX Librae

    NASA Technical Reports Server (NTRS)

    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. Genetic markers: Potential candidates for cardiovascular disease.

    PubMed

    Rather, Riyaz Ahmad; Dhawan, Veena

    2016-10-01

    The effective prevention of cardiovascular disease depends upon the ability to recognize the high-risk individuals at an early stage of the disease or long before the development of adverse events. Evolving technologies in the fields of proteomics, metabolomics, and genomics have played a significant role in the discovery of cardiovascular biomarkers, but so far these methods have achieved the modest success. Hence, there is a crucial need for more reliable, suitable, and lasting diagnostic and therapeutic markers to screen the disease well in time to start the clinical aid to the patients. Gene polymorphisms associated with the cardiovascular disease play a decisive role in the disease onset. Therefore, the genetic marker evaluation to classify high-risk patients from low-risk patients trends an effective approach to patient management and care. Currently, there are no genetic markers available for extensive adoption as risk factors for coronary vascular disease, yet, there are numerous promising, biologically acceptable candidates. Many of these gene biomarkers, alone or in combination, can play an essential role in the prediction of cardiovascular risk. The present review highlights some putative emerging genetic biomarkers that could facilitate more authentic and fast diagnosis of CVD. This review also briefly describes few technological approaches employed in the biomarker search. PMID:27416153

  16. Identification of Candidate Predictors of Lupus Flare.

    PubMed

    Crow, Mary K; Olferiev, Mikhail; Kirou, Kyriakos A

    2015-01-01

    Systemic lupus erythematosus, the prototype systemic autoimmune disease, is characterized by extensive self-reactivity, inflammation, and organ system damage. Sustained production of type I interferon is seen in many patients and contributes to immune dysregulation. Disease activity fluctuates with periods of relative quiescence or effective management by immunosuppressive drugs, followed by disease flares. Tissue damage accumulates over time, with kidneys and cardiovascular system particularly affected. Identification of the underlying molecular mechanisms that precede clinical exacerbations, allowing prediction of future flare, could lead to therapeutic interventions that prevent severe disease. We generated gene expression data from a longitudinal cohort of lupus patients, some showing at least one period of severe flare and others with relatively stable disease over the period of study. Candidate predictors of future clinical flare were identified based on analysis of differentially expressed gene transcripts between the flare and non-flare groups at a time when all patients had relatively quiescent clinical disease activity. Our results suggest the hypothesis that altered regulation of genome stability and nucleic acid fidelity may be important molecular precursors of future clinical flare, generating endogenous nucleic acid triggers that engage intracellular mechanisms that mimic a chronic host response to viral infection.

  17. Infrared Spectroscopy of Black Hole Candidates

    NASA Astrophysics Data System (ADS)

    Colgan, S. W. J.; Cotera, A. S.; Maloney, P. R.; Hollenbach, D. J.

    2000-05-01

    ISO LWS and SWS observations of the solar mass black hole candidates 1E1740.7-2942 and GRS1758-258 are presented. For 1E1740.7-2942, it has been suggested that the luminosity is provided in whole or part by Bondi-Hoyle accretion from a surrounding black hole (Bally & Leventhal 1991, Nat, 353, 234). Maloney etal. (1997, ApJ 482, L41) have predicted that detectable far-infrared line emission from [OI] (63 microns), [CII] (158 microns), [SiII] (35 microns) and other lines will arise from black holes which are embedded in molecular clouds. No strong line emission associated with either 1E1740.7-2942 or GRS1758-258 was detected, implying either that 1) these sources are not embedded in dense molecular clouds, or 2) that their average X-ray luminosity over the past 100 years is significantly lower than its current value. The measured upper limits to the line fluxes are compared with the models of Maloney etal. to constrain the properties of the ISM in the vicinity of these X-ray sources. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) and with the participation of ISAS and NASA.

  18. Genetic markers: Potential candidates for cardiovascular disease.

    PubMed

    Rather, Riyaz Ahmad; Dhawan, Veena

    2016-10-01

    The effective prevention of cardiovascular disease depends upon the ability to recognize the high-risk individuals at an early stage of the disease or long before the development of adverse events. Evolving technologies in the fields of proteomics, metabolomics, and genomics have played a significant role in the discovery of cardiovascular biomarkers, but so far these methods have achieved the modest success. Hence, there is a crucial need for more reliable, suitable, and lasting diagnostic and therapeutic markers to screen the disease well in time to start the clinical aid to the patients. Gene polymorphisms associated with the cardiovascular disease play a decisive role in the disease onset. Therefore, the genetic marker evaluation to classify high-risk patients from low-risk patients trends an effective approach to patient management and care. Currently, there are no genetic markers available for extensive adoption as risk factors for coronary vascular disease, yet, there are numerous promising, biologically acceptable candidates. Many of these gene biomarkers, alone or in combination, can play an essential role in the prediction of cardiovascular risk. The present review highlights some putative emerging genetic biomarkers that could facilitate more authentic and fast diagnosis of CVD. This review also briefly describes few technological approaches employed in the biomarker search.

  19. Spectroscopic observations of cool degenerate star candidates

    NASA Technical Reports Server (NTRS)

    Hintzen, P.

    1986-01-01

    Spectroscopic observations are reported for 23 Luyten Half-Second degenerate star candidates and for 13 Luyten-Palomar common proper-motion pairs containing possible degenerate star components. Twenty-five degenerate stars are identified, 20 of which lack previous spectroscopy. Most of these stars are cool - Luyten color class g or later. One star, LP 77-57, shows broad continuum depressions similar to those in LHS 1126, which Liebert and Dahn attributed to pressure-shifted C2. A second degenerate star, LHS 290, exhibits apparent strong Swan bands which are blueshifted about 75 A. Further observations, including polarimetry and photometry, are required to appraise the spectroscopic peculiarities of these stars. Finally, five cool, sharp-lined DA white dwarfs have been observed to detect lines of metals and to determine line strengths. None of these DAs show signs of Mg b or the G band, and four show no evidence of Ca II K. The attempt to detect Ca MI in the fifth star, G199-71, was inconclusive.

  20. Ailing Voters Advance Attractive Congressional Candidates

    PubMed Central

    Franklin, Robert G.; Palumbo, Rocco

    2015-01-01

    Among many benefits of facial attractiveness, there is evidence that more attractive politicians are more likely to be elected. Recent research found this effect to be most pronounced in congressional districts with high disease threat—a result attributed to an adaptive disease avoidance mechanism, whereby the association of low attractiveness with poor health is particularly worrisome to voters who feel vulnerable to disease. We provided a more direct test of this explanation by examining the effects of individuals’ own health and age. Supporting a disease avoidance mechanism, less healthy participants showed a stronger preference for more attractive contenders in U.S. Senate races than their healthier peers, and this effect was stronger for older participants, who were generally less healthy than younger participants. Stronger effects of health for older participants partly reflected the absence of positive bias toward attractive candidates among the healthiest, suggesting that healthy older adults may be unconcerned about disease threat or sufficiently wise to ignore attractiveness. PMID:25562113

  1. A Catalog of Kepler Habitable Zone Exoplanet Candidates

    NASA Astrophysics Data System (ADS)

    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.

  2. 32 CFR 901.6 - Candidate fitness test requirement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Director of Athletics if a candidate's participation in high school athletics conflicts with test... TRAINING AND SCHOOLS APPOINTMENT TO THE UNITED STATES AIR FORCE ACADEMY Appointment Policies...

  3. 32 CFR 901.6 - Candidate fitness test requirement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Director of Athletics if a candidate's participation in high school athletics conflicts with test... TRAINING AND SCHOOLS APPOINTMENT TO THE UNITED STATES AIR FORCE ACADEMY Appointment Policies...

  4. 32 CFR 901.6 - Candidate fitness test requirement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Director of Athletics if a candidate's participation in high school athletics conflicts with test... TRAINING AND SCHOOLS APPOINTMENT TO THE UNITED STATES AIR FORCE ACADEMY Appointment Policies...

  5. 32 CFR 901.6 - Candidate fitness test requirement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Director of Athletics if a candidate's participation in high school athletics conflicts with test... TRAINING AND SCHOOLS APPOINTMENT TO THE UNITED STATES AIR FORCE ACADEMY Appointment Policies...

  6. 32 CFR 901.6 - Candidate fitness test requirement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Director of Athletics if a candidate's participation in high school athletics conflicts with test... TRAINING AND SCHOOLS APPOINTMENT TO THE UNITED STATES AIR FORCE ACADEMY Appointment Policies...

  7. ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

    SciTech Connect

    Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.; Bryson, Stephen T.; Howell, Steve B.; Ragozzine, Darin; Holman, Matthew J.; Carter, Joshua A.; Fabrycky, Daniel C.; Fortney, Jonathan J.; Steffen, Jason H.; Ford, Eric B.; Shporer, Avi; Rowe, Jason F.; Quintana, Elisa V.; Caldwell, Douglas A.; Ciardi, David; Gautier, Thomas N. III; and others

    2011-11-01

    About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.

  8. UM 425: a new gravitational lens candidate.

    NASA Astrophysics Data System (ADS)

    Meylan, G.; Djorgovski, S.

    1988-12-01

    Since the first theoretical discussions more than 50 years ago on the phenomenon of light rays bent by intervening mass in the universe (Eddington 1920, Einstein 1936, Zwicky 1937 a, b), gravitational lensing has steadily grown to become one of the most active fields of research in extragalactic astronomy today. There are numerous theoretical investigations (Refsdal 1964, 1966, Turner et al. 1984, Blandford and Narayan 1986, Blandford and Kochanek 1987a, b), but the observations of good gravitationallens candidates are still rare. It is only during the last decade that a few quasar systems have been found in reasonable agreement with the gravitational lensing interpretation, viz., 0957 + 561 (Walsh et al. 1979), 1115 + 080 (Weymann et al. 1980), 2016 + 112 (Lawrence et al. 1983), 2237 + 030 (Huchra et al. 1985), 0142-100 (Surdej et al. 1987), and 1413+ 117 (Magain et al. 1988). In other possible cases, e.g., 2345+007 ryveedman et al. 1982), and 1635+267 (Djorgovski and Spinrad 1984), there has so far been no detection of lensing galaxies, and thus they should possibly be considered as genuine pairs of interacting quasars, similar to the probable binary quasar PKS 1145-071 (Djorgovski et al. 1987). Recently, so-called giant luminous arcs have been observed in a few clusters of galaxies. They are interpreted as segments of Einstein rings, created because of an almost perfect alignment of the lensing cluster potential weil with the lensed background object (Soucail et al. 1988, Lynds and Petrosian 1988). Blandford and Kochanek (1987) provide the most comprehensive and updated review on these subjects.

  9. Alphavirus replicon particles as candidate HIV vaccines.

    PubMed

    Davis, Nancy L; West, Ande; Reap, Elizabeth; MacDonald, Gene; Collier, Martha; Dryga, Sergey; Maughan, Maureen; Connell, Mary; Walker, Chris; McGrath, Kathryn; Cecil, Chad; Ping, Li-Hua; Frelinger, Jeff; Olmsted, Robert; Keith, Paula; Swanstrom, Ronald; Williamson, Carolyn; Johnson, Philip; Montefiori, David; Johnston, Robert E

    2002-01-01

    Replicon particles based on Venezuelan equine encephalitis virus (VEE) contain a self-replicating RNA encoding the VEE replicase proteins and expressing a gene of interest in place of the viral structural protein genes. Structural proteins for packaging of replicon RNA into VEE replicon particles (VRPs) are expressed from separate helper RNAs. Aspects of the biology of VEE that are exploited in VRP vaccines include 1) expression of very high levels of immunogen, 2) expression of immunizing proteins in cells in the draining lymph node, and 3) the ability to induce mucosal immunity from a parental inoculation. Results of experiments with VRPs expressing green fluorescent protein or influenza virus hemagglutinin (HA) demonstrated that specific mutations in the VRP envelope glycoproteins affect both targeting in the draining lymph node and efficiency of the immune response in mice. VRPs expressing either the matrix-capsid portion of Gag, the full-length envelope gp160, or the secreted gp140 of cloned SIVsm H-4i were mixed in a cocktail and used to immunize macaques at 0, 1, and 4 months. Neutralizing antibodies against SIVsm H-4 were induced in 6 of 6 vaccinates and CTL in 4 of 6. An intrarectal challenge with the highly pathogenic SIVsm E660 was given at 5 months. A vaccine effect was seen in reduced peak virus loads, reduced virus loads both at set point and at 41 weeks postchallenge, and preserved or increased CD4 counts compared to controls. A candidate VRP HIV vaccine expressing Clade C Gag contains a sequence that is very close to the South African Clade C consensus and was selected from a recent seroconverter in the Durban cohort to represent currently circulating genotypes in South Africa. A GMP lot of this vaccine has been manufactured and tested for a phase I trial in the first months of 2002.

  10. Sensitive radio survey of obscured quasar candidates

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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 6.0GHz 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 νLν[1.4 GHz]⪉ 10^{40} 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 (˜40μJy - 40mJy) field radio sources observed over ˜120 arcmin2 of our data. 60% 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.

  11. Spectroscopic distances of 28 nearby star candidates

    NASA Astrophysics Data System (ADS)

    Jahreiß, H.; Meusinger, H.; Scholz, R.-D.; Stecklum, B.

    2008-06-01

    Aims: Twenty eight hitherto neglected candidates for the Catalogue of Nearby Stars (CNS) were investigated to verify their classification and to improve their distance estimates. All targets had at least a preliminary status of being nearby dwarf stars based on their large proper motions and relatively faint magnitudes. Better photometric and/or spectroscopic distances were required for selecting stars for further trigonometric parallax measurements. Methods: Low-resolution spectra were obtained with NASPEC at the Tautenburg 2 m telescope and with CAFOS at the Calar Alto 2.2 m telescope. The spectral types of M-type stars were determined by direct comparison of the target's spectra with those of comparison stars of known spectral types observed with the same instrument. The classification of earlier types was performed based on comparison with published spectral libraries. Results: For most of the target stars reliable spectral types could be determined and in combination with 2MASS photometry new improved distance estimates became available. The majority were classified as M dwarfs including 11 stars within 25 pc. The fainter component of LDS 1365, previously thought to form a nearby common proper motion pair, is according to our results an unrelated high-velocity background star. For several other nearby common proper motion pairs our distance estimates of the fainter components are in good agreement with Hipparcos distances of the brighter components. The three stars in our sample that were previously thought to be white dwarfs (GJ 2091, GJ 2094, GJ 2098) turned out to be more distant high-velocity F- to K-type (sub)dwarfs. For the star with the largest tangential velocity (GJ 2091; v_ tan>500 km s-1) we have additional evidence for its probable Galactic halo membership from a measured large radial velocity of 266 ± 25 km s-1 and from its UBV photometry indicating a low metallicity. Based on observations with the 2 m telescope of the Thüringer Landessternwarte

  12. Evolution and magnitudes of candidate Planet Nine

    NASA Astrophysics Data System (ADS)

    Linder, Esther F.; Mordasini, Christoph

    2016-05-01

    Context. The recently renewed interest in a possible additional major body in the outer solar system prompted us to study the thermodynamic evolution of such an object. We assumed that it is a smaller version of Uranus and Neptune. Aims: We modeled the temporal evolution of the radius, temperature, intrinsic luminosity, and the blackbody spectrum of distant ice giant planets. The aim is also to provide estimates of the magnitudes in different bands to assess whether the object might be detectable. Methods: Simulations of the cooling and contraction were conducted for ice giants with masses of 5, 10, 20, and 50 M⊕ that are located at 280, 700, and 1120 AU from the Sun. The core composition, the fraction of H/He, the efficiency of energy transport, and the initial luminosity were varied. The atmospheric opacity was set to 1, 50, and 100 times solar metallicity. Results: We find for a nominal 10 M⊕ planet at 700 AU at the current age of the solar system an effective temperature of 47 K, much higher than the equilibrium temperature of about 10 K, a radius of 3.7 R⊕, and an intrinsic luminosity of 0.006 L♃. It has estimated apparent magnitudes of Johnson V, R, I, L, N, Q of 21.7, 21.4, 21.0, 20.1, 19.9, and 10.7, and WISE W1-W4 magnitudes of 20.1, 20.1, 18.6, and 10.2. The Q and W4 band and other observations longward of about 13 μm pick up the intrinsic flux. Conclusions: If candidate Planet 9 has a significant H/He layer and an efficient energy transport in the interior, then its luminosity is dominated by the intrinsic contribution, making it a self-luminous planet. At a likely position on its orbit near aphelion, we estimate for a mass of 5, 10, 20, and 50 M⊕ a V magnitude from the reflected light of 24.3, 23.7, 23.3, and 22.6 and a Q magnitude from the intrinsic radiation of 14.6, 11.7, 9.2, and 5.8. The latter would probably have been detected by past surveys.

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

    ERIC Educational Resources Information Center

    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…

  14. Is there a blackhole among the black-hole candidates?

    NASA Astrophysics Data System (ADS)

    Kundt, Wolfgang; Fischer, Daniel

    1989-03-01

    None of the tentative black-hole identifications has remained without serious difficulties. As a class, the black-hole candidates differ in no obvious property from neutron-star binaries other than in their estimated high mass. An interpretation of the black-hole candidates as binary neutron stars surrounded by a more or less massive accretion disk is favored.

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

    ERIC Educational Resources Information Center

    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…

  16. Preparing Preservice Teacher Candidates to Differentiate Instructional Practices

    ERIC Educational Resources Information Center

    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…

  17. 29 CFR 452.46 - Characteristics of candidate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false Characteristics of candidate. 452.46 Section 452.46 Labor... DISCLOSURE ACT OF 1959 Candidacy for Office; Reasonable Qualifications § 452.46 Characteristics of candidate... of personal characteristics which have a direct bearing on fitness for union office. A union may,...

  18. Opinions of Counselor Candidates Regarding Counseling Skills Training

    ERIC Educational Resources Information Center

    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…

  19. MAT@USC Candidates and Latino English Language Learners

    ERIC Educational Resources Information Center

    Lomeli, Cynthia Leticia

    2012-01-01

    The purpose of this study was to further understand the perceptions of MAT@USC teacher candidates and how their perceptions and previous experiences affect the educational experiences of Latino English language learners. Three questions were developed to guide this study: (1) What are the perceptions of MAT@USC candidates in selected courses…

  20. 29 CFR 452.31 - One candidate for several offices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false One candidate for several offices. 452.31 Section 452.31... AND DISCLOSURE ACT OF 1959 Frequency and Kinds of Elections § 452.31 One candidate for several offices... perform the functions of more than one office, a separate election need not be held for each office....

  1. Teacher Candidates' Perceptions of Technology Supported Literacy Practices

    ERIC Educational Resources Information Center

    Wake, Donna; Whittingham, Jeff

    2013-01-01

    This study explores teacher education candidates' perceptions of technologies used to support K-12 student literacy development. Candidates scored each technology based on their impressions of its ability to support student literacy development. They also evaluated their own level of expertise with each piece of technology using a pre-post…

  2. Developing Benchmarks to Measure Teacher Candidates' Performance

    ERIC Educational Resources Information Center

    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…

  3. Teacher Candidate Technology Integration: For Student Learning or Instruction?

    ERIC Educational Resources Information Center

    Clark, Cynthia; Zhang, Shaoan; Strudler, Neal

    2015-01-01

    Transfer of instructional technology knowledge for student-centered learning by teacher candidates is investigated in this study. Using the transfer of learning theoretical framework, a mixed methods research design was employed to investigate whether secondary teacher candidates were able to transfer the instructional technology knowledge for…

  4. Teacher Candidates' Views of Digital Games as Learning Devices

    ERIC Educational Resources Information Center

    Sardone, Nancy B.; Devlin-Scherer, Roberta

    2009-01-01

    The objective of this research study was to explore teacher candidate views toward digital learning games using an immersive strategy. Specifically, we were interested in finding out what game use in classroom settings taught candidates about the role of teacher as facilitator of instruction. The procedures first focused teacher candidate…

  5. Screening Teacher Candidates: Luck of the Draw or Objective Selection?

    ERIC Educational Resources Information Center

    Bolz, Anthony James

    2009-01-01

    This study was an attempt to gain an understanding of what tools and strategies elementary school administrators in Wisconsin use to screen teacher candidates during the hiring process. The results were analyzed to determine the extent to which administrators are screening for characteristics of candidates that predict success in the classroom. …

  6. Mathematics Teacher Candidates' Metaphors about the Concept of "Mathematics"

    ERIC Educational Resources Information Center

    Erdogan, Ahmet; Yazlik, Derya Ozlem; Erdik, Cengiz

    2014-01-01

    The main purpose of this study was to research mathematics teacher candidates' perceptions about the concept of "mathematics" through the use of metaphors. The research is conducted during 2012-2013 academic year, on a group of 111 mathematics teacher candidates at the Education Faculty of a University in Turkey. To collect the research…

  7. Chemical Literacy Levels of Science and Mathematics Teacher Candidates

    ERIC Educational Resources Information Center

    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…

  8. 14 CFR 1214.1106 - Selection of astronaut candidates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Selection of astronaut candidates. 1214.1106 Section 1214.1106 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1106 Selection of...

  9. 14 CFR 1214.1106 - Selection of astronaut candidates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Selection of astronaut candidates. 1214.1106 Section 1214.1106 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1106 Selection of...

  10. 14 CFR 1214.1106 - Selection of astronaut candidates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Selection of astronaut candidates. 1214.1106 Section 1214.1106 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1106 Selection of...

  11. 14 CFR § 1214.1106 - Selection of astronaut candidates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Selection of astronaut candidates. § 1214.1106 Section § 1214.1106 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT NASA Astronaut Candidate Recruitment and Selection Program § 1214.1106 Selection of...

  12. Facebook Connection Styles among Physical Education Teacher Candidates

    ERIC Educational Resources Information Center

    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…

  13. Educational Leadership Preparation: What Supervisors, Candidates, and Mentors Said

    ERIC Educational Resources Information Center

    Tubbs, J. Eric; Holliday, H. E.

    2009-01-01

    The findings of this study identified practicum areas that meet the educational demands of candidates while highlighting practicum areas that need improvement. The study contributes to the knowledge base of the field by drawing upon feedback from university supervisors, school mentors and program candidates to evaluate and improve the practicum…

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

    ERIC Educational Resources Information Center

    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…

  15. Academic Self-Efficacy Perceptions of Teacher Candidates

    ERIC Educational Resources Information Center

    Yesilyurt, Etem

    2013-01-01

    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 Kelesoglu Education Faculty of Education Formation of Selcuk University. A simple random sample was selected as sampling method and the study was…

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  18. Pathogenic Network Analysis Predicts Candidate Genes for Cervical Cancer

    PubMed Central

    Zhang, Yun-Xia

    2016-01-01

    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. PMID:27034707

  19. Novel low profile antenna candidates for EHF portable terminals

    NASA Technical Reports Server (NTRS)

    Roscoe, D.; Shafai, L.; Ittipiboon, A.; Cuhaci, M.; Moheb, H.

    1995-01-01

    This paper presents three low profile antenna candidates for EHF portable communication terminals. The first structure is a planar, multilayer microstrip antenna utilizing electromagnetic coupling to minimize the complexity and losses associated with the feed network. The second candidate is a medium gain (15 dB) radiating cavity antenna utilizing a thick metallic ground plane. This element is amenable to device integration because a heat sink is incorporated and an area is available for fastening modular RF components. Thirdly, as an alternative to microstrip antennas, dielectric resonator antennas (DRA's) are presented. A broadband (28 percent) DRA is discussed. Experimental measurements are presented for all three antenna candidates.

  20. Halo Stream candidates in the LAMOST DR2

    NASA Astrophysics Data System (ADS)

    Zhao, Jingkun

    2015-08-01

    We have detected eight stellar halo stream candidates in the solar neighborhood using a sample including 64,819 FGK metal-poor ([Fe/H] < -0.7) dwarfs extracted from the cross-match among the LAMOST DR2, WISE, 2MASS and PPMXL catalogues. With the strategy of halo stream detection in Klement et al, several significant ‘phase-space overdensi- ties” of stars on very similar orbits are identified. Three structures are known previously. Five new halo stream candidates are also found. The kinematics and metallicity of these stream candidates are then analyzed. Detailed element abundance are needed to better know the ori-gin of these streams.

  1. Official portrait of 1987 astronaut candidate Bruce E. Melnick

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Official portrait of 1987 astronaut candidate Bruce E. Melnick. Melnick, a member of the United States Coast Guard (USCG) and Astronaut Class 12, wears navy blue flight suit and holds space shuttle orbiter model.

  2. Single Event Effects Results for Candidate Spacecraft Electronics for NASA

    NASA Technical Reports Server (NTRS)

    O'Bryan, Martha; LaBel, Kenneth A.; Kniffin, Scott D.; Howard, James W., Jr.; Poivey, Christian; Ladbury, Ray L.; Buchner, Stephen P.; Xapsos, Michael; Reed, Robert A.; Sanders, Anthony B.

    2003-01-01

    We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects. Devices tested include digital, analog, linear bipolar, and hybrid devices, among others.

  3. Official portrait of 1987 astronaut candidate Kenneth S. Reightler, Jr

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Official portrait of 1987 astronaut candidate Kenneth S. Reightler, Jr. Reightler, a member of the United States Navy and Astronaut Class 12, wears a navy blue flight suit and holds a space shuttle orbiter model.

  4. Questions and Answers for Transplant Candidates about Kidney Allocation Policy

    MedlinePlus

    ... factors include: • Age • Length of time spent on dialysis • Having received a previous transplant (of any organ) • ... candidates who are less able to stay on dialysis for a long time. The 15 percent of ...

  5. 11 CFR 100.88 - Volunteer activity for candidates.

    Code of Federal Regulations, 2010 CFR

    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...

  6. 11 CFR 100.148 - Volunteer activity for candidate.

    Code of Federal Regulations, 2010 CFR

    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...

  7. Transiting exoplanet candidates from K2 Campaigns 5 and 6

    NASA Astrophysics Data System (ADS)

    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.

  8. Political partisanship influences perception of biracial candidates' skin tone

    PubMed Central

    Caruso, Eugene M.; Mead, Nicole L.; Balcetis, Emily

    2009-01-01

    People tend to view members of their own political group more positively than members of a competing political group. In this article, we demonstrate that political partisanship influences people's visual representations of a biracial political candidate's skin tone. In three studies, participants rated the representativeness of photographs of a hypothetical (Study 1) or real (Barack Obama; Studies 2 and 3) biracial political candidate. Unbeknownst to participants, some of the photographs had been altered to make the candidate's skin tone either lighter or darker than it was in the original photograph. Participants whose partisanship matched that of the candidate they were evaluating consistently rated the lightened photographs as more representative of the candidate than the darkened photographs, whereas participants whose partisanship did not match that of the candidate showed the opposite pattern. For evaluations of Barack Obama, the extent to which people rated lightened photographs as representative of him was positively correlated with their stated voting intentions and reported voting behavior in the 2008 Presidential election. This effect persisted when controlling for political ideology and racial attitudes. These results suggest that people's visual representations of others are related to their own preexisting beliefs and to the decisions they make in a consequential context. PMID:19934033

  9. Political partisanship influences perception of biracial candidates' skin tone.

    PubMed

    Caruso, Eugene M; Mead, Nicole L; Balcetis, Emily

    2009-12-01

    People tend to view members of their own political group more positively than members of a competing political group. In this article, we demonstrate that political partisanship influences people's visual representations of a biracial political candidate's skin tone. In three studies, participants rated the representativeness of photographs of a hypothetical (Study 1) or real (Barack Obama; Studies 2 and 3) biracial political candidate. Unbeknownst to participants, some of the photographs had been altered to make the candidate's skin tone either lighter or darker than it was in the original photograph. Participants whose partisanship matched that of the candidate they were evaluating consistently rated the lightened photographs as more representative of the candidate than the darkened photographs, whereas participants whose partisanship did not match that of the candidate showed the opposite pattern. For evaluations of Barack Obama, the extent to which people rated lightened photographs as representative of him was positively correlated with their stated voting intentions and reported voting behavior in the 2008 Presidential election. This effect persisted when controlling for political ideology and racial attitudes. These results suggest that people's visual representations of others are related to their own preexisting beliefs and to the decisions they make in a consequential context. PMID:19934033

  10. Candidate gene discovery and prioritization in rare diseases.

    PubMed

    Jegga, Anil G

    2014-01-01

    A rare or orphan disorder is any disease that affects a small percentage of the population. Most genes and pathways underlying these disorders remain unknown. High-throughput techniques are frequently applied to detect disease candidate genes. The speed and affordability of sequencing following recent technological advances while advantageous are accompanied by the problem of data deluge. Furthermore, experimental validation of disease candidate genes is both time-consuming and expensive. Therefore, several computational approaches have been developed to identify the most promising candidates for follow-up studies. Based on the guilt by association principle, most of these approaches use prior knowledge about a disease of interest to discover and rank novel candidate genes. In this chapter, a brief overview of some of the in silico strategies for candidate gene prioritization is provided. To demonstrate their utility in rare disease research, a Web-based computational suite of tools that use integrated heterogeneous data sources for ranking disease candidate genes is used to demonstrate how to run typical queries using this system.

  11. Young Stellar Object Candidates in the Aquila Rift Region

    NASA Astrophysics Data System (ADS)

    Zhang, Miao-miao; Wang, Hong-chi; Stecklum, B.

    2010-10-01

    Using the 2m telescope of the Turingia State Observatory at Tauten-berg (TLS), imaging observations in 3 wavebands (H α, R and I) are performed in the 16 fields in the Aquila Rift region. The observed fields cover about 7 square degrees. Excluding the 3 fields with unqualified data, the photometrical analysis is made for the remaining 13 fields, from which point sources are identified, and finally 7 H α emission-line star candidates are identified by color-color diagrams. The 7 candidates are located in five fields. Three of them are located near the Galactic plane, while the galactic latitudes of the rest are greater than 4°. The 2 M ASS counterparts of the point sources are identified, and the properties of the 7 H α emission-line star candidates are further analyzed by using the two-color diagrams. It is found that the near-infrared radiation from these H α emission-line star candidates has no obvious infrared excess, one of them even falls on the main-sequence branch. This indicates that the H α-emissive young stellar objects (YSOs) are not always accompanied with the infrared excess, and that the results of the H α emission line observation and the infrared excess observation are mutually supplemented. If the 7 H α emission-line star candidates are regarded as YSO candidates, then the number of YSOs in the Aquila Rift region is quite small. The further confirmation of these candidates needs subsequent spectral observations.

  12. ALMOST ALL OF KEPLER'S MULTIPLE-PLANET CANDIDATES ARE PLANETS

    SciTech Connect

    Lissauer, Jack J.; Rowe, Jason F.; Bryson, Stephen T.; Howell, Steve B.; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G.; Marcy, Geoffrey W.; Adams, Elisabeth; Fressin, Francois; Geary, John; Holman, Matthew J.; Ragozzine, Darin; Buchhave, Lars A.; Ciardi, David R.; Fabrycky, Daniel C.; Ford, Eric B.; Morehead, Robert C.; Gilliland, Ronald L.; and others

    2012-05-10

    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 (1) the planetary system orbits a fainter star, and the planets are thus significantly larger than has been estimated, or (2) the planets orbit different stars within a binary/multiple star system. We use the low overall false-positive rate among Kepler multis, together with analysis of Kepler spacecraft and ground-based data, to validate the closely packed Kepler-33 planetary system, which orbits a star that has evolved somewhat off of the main sequence. Kepler-33 hosts five transiting planets, with periods ranging from 5.67 to 41 days.

  13. Emotional and Affective Temperaments in Smoking Candidates for Bariatric Surgery

    PubMed Central

    Mombach, Karin Daniele; de Souza Brito, Cesar Luis; Padoin, Alexandre Vontobel; Casagrande, Daniela Schaan; Mottin, Claudio Cora

    2016-01-01

    Introduction The prevalence of smoking habits in severe obesity is higher than in the general population. There is some evidence that smokers have different temperaments compared to non-smokers. The aim of this study is to evaluate the associations between smoking status (smokers, ex-smokers and non-smokers) and temperament characteristics in bariatric surgery candidates. Methods We analyzed data on temperament of 420 bariatric surgery candidates, as assessed by the AFECTS scale, in an exploratory cross-sectional survey of bariatric surgery candidates who have been grouped into smokers, ex-smokers and non-smokers. Results We detected significant statistical differences in temperament related to the smoking status in this population after controlling the current use of psychiatric medication. Smokers had higher anxiety and lower control than non-smokers. Ex-smokers with BMI >50 kg/m2 presented higher coping and control characteristics than smokers. Conclusions Smoking in bariatric surgery candidates was associated with lower control and higher anxious temperament, when controlled by current use of psychiatric medication. Smokers with BMI >50 kg/m2 presented lower coping and control than ex-smokers. Assessment of temperament in bariatric surgery candidates may help in decisions about smoking cessation treatment and prevention of smoking relapse after surgery. PMID:26987115

  14. Unifying Candidate Gene and GWAS Approaches in Asthma

    PubMed Central

    Michel, Sven; Liang, Liming; Depner, Martin; Klopp, Norman; Ruether, Andreas; Kumar, Ashish; Schedel, Michaela; Vogelberg, Christian; von Mutius, Erika; von Berg, Andrea; Bufe, Albrecht; Rietschel, Ernst; Heinzmann, Andrea; Laub, Otto; Simma, Burkhard; Frischer, Thomas; Genuneit, Jon; Gut, Ivo G.; Schreiber, Stefan; Lathrop, Mark; Illig, Thomas; Kabesch, Michael

    2010-01-01

    The first genome wide association study (GWAS) for childhood asthma identified a novel major susceptibility locus on chromosome 17q21 harboring the ORMDL3 gene, but the role of previous asthma candidate genes was not specifically analyzed in this GWAS. We systematically identified 89 SNPs in 14 candidate genes previously associated with asthma in >3 independent study populations. We re-genotyped 39 SNPs in these genes not covered by GWAS performed in 703 asthmatics and 658 reference children. Genotyping data were compared to imputation data derived from Illumina HumanHap300 chip genotyping. Results were combined to analyze 566 SNPs covering all 14 candidate gene loci. Genotyped polymorphisms in ADAM33, GSTP1 and VDR showed effects with p-values <0.0035 (corrected for multiple testing). Combining genotyping and imputation, polymorphisms in DPP10, EDN1, IL12B, IL13, IL4, IL4R and TNF showed associations at a significance level between p = 0.05 and p = 0.0035. These data indicate that (a) GWAS coverage is insufficient for many asthma candidate genes, (b) imputation based on these data is reliable but incomplete, and (c) SNPs in three previously identified asthma candidate genes replicate in our GWAS population with significance after correction for multiple testing in 14 genes. PMID:21103062

  15. Integrative analysis to select cancer candidate biomarkers to targeted validation.

    PubMed

    Kawahara, Rebeca; Meirelles, Gabriela V; Heberle, Henry; Domingues, Romênia R; Granato, Daniela C; Yokoo, Sami; Canevarolo, Rafael R; Winck, Flavia V; Ribeiro, Ana Carolina P; Brandão, Thaís Bianca; Filgueiras, Paulo R; Cruz, Karen S P; Barbuto, José Alexandre; Poppi, Ronei J; Minghim, Rosane; Telles, Guilherme P; Fonseca, Felipe Paiva; Fox, Jay W; Santos-Silva, Alan R; Coletta, Ricardo D; Sherman, Nicholas E; Paes Leme, Adriana F

    2015-12-22

    Targeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS.

  16. Integrative analysis to select cancer candidate biomarkers to targeted validation

    PubMed Central

    Heberle, Henry; Domingues, Romênia R.; Granato, Daniela C.; Yokoo, Sami; Canevarolo, Rafael R.; Winck, Flavia V.; Ribeiro, Ana Carolina P.; Brandão, Thaís Bianca; Filgueiras, Paulo R.; Cruz, Karen S. P.; Barbuto, José Alexandre; Poppi, Ronei J.; Minghim, Rosane; Telles, Guilherme P.; Fonseca, Felipe Paiva; Fox, Jay W.; Santos-Silva, Alan R.; Coletta, Ricardo D.; Sherman, Nicholas E.; Paes Leme, Adriana F.

    2015-01-01

    Targeted proteomics has flourished as the method of choice for prospecting for and validating potential candidate biomarkers in many diseases. However, challenges still remain due to the lack of standardized routines that can prioritize a limited number of proteins to be further validated in human samples. To help researchers identify candidate biomarkers that best characterize their samples under study, a well-designed integrative analysis pipeline, comprising MS-based discovery, feature selection methods, clustering techniques, bioinformatic analyses and targeted approaches was performed using discovery-based proteomic data from the secretomes of three classes of human cell lines (carcinoma, melanoma and non-cancerous). Three feature selection algorithms, namely, Beta-binomial, Nearest Shrunken Centroids (NSC), and Support Vector Machine-Recursive Features Elimination (SVM-RFE), indicated a panel of 137 candidate biomarkers for carcinoma and 271 for melanoma, which were differentially abundant between the tumor classes. We further tested the strength of the pipeline in selecting candidate biomarkers by immunoblotting, human tissue microarrays, label-free targeted MS and functional experiments. In conclusion, the proposed integrative analysis was able to pre-qualify and prioritize candidate biomarkers from discovery-based proteomics to targeted MS. PMID:26540631

  17. New DNA markers in the Huntington's disease gene candidate region.

    PubMed

    Lin, C S; Altherr, M; Bates, G; Whaley, W L; Read, A P; Harris, R; Lehrach, H; Wasmuth, J J; Gusella, J F; MacDonald, M E

    1991-09-01

    The search for the Huntington's disease (HD) gene has prompted construction of a complete long-range restriction map of a 2.5-Mb candidate region, distal to the DNA marker D4S10. To facilitate the procurement of cloned DNA from this candidate region, we have augmented the existing regional mapping panel of somatic cell hybrids with hybrid HHW1071 containing a t(4p16;12) chromosome from a patient with Wolf-Hirschhorn syndrome. This translocation maps between D4S180 and D4S127, subdividing the HD candidate region and setting a proximal limit to the Wolf-Hirschhorn syndrome region. Using the expanded mapping panel, we have regionally assigned 14 independently cloned cosmids, five proximal to the t(4;12) breakpoint in the same region as D4S10 and nine distal to the breakpoint. By a combination of overlap with previously mapped cosmids and pulsed-field gel analysis, each of these cosmids has been positioned on the long-range restriction map of 4p16.3, increasing the clone coverage of the candidate region to approximately 40%. Single-copy probes from mapped cosmids were used to identify eight new DNA polymorphisms spanning the HD candidate region. These new DNA markers should prove valuable for analysis of recombination and linkage disequilibrium in HD, as well as for preclinical diagnosis of the disorder.

  18. Evaluation and selection of candidate high-level waste forms

    SciTech Connect

    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.

  19. Psychophysiological evaluation of candidates to work at sea.

    PubMed

    Nitka, J; Dolmierski, R

    1983-01-01

    With appliance of clinical psychiatric examination, the examination of the reactivity of vegetative system and the psychological examination--the occurrence of neuroses and neurotic syndromes was evaluated in candidates to work in Polish Merchant Marine. About 7% of neuroses and neurotic syndromes were noted in this group. An analysis was carried out with consideration of the school graduated, of the military service completed and of the section in which the candidate wants to be employed. No differences were found in the whole group in comparison with the graduates of maritime schools, as well as no differences were noted between the candidates to individual sections. Less disturbances were ascertained among the reservists of the Navy. PMID:6681354

  20. A new tribological test for candidate brush seal materials evaluation

    SciTech Connect

    Fellenstein, J.A.; DellaCorte, C.

    1994-10-01

    A new tribological test for candidate brush seal materials evaluation has been developed. The sliding contact between the brush seal wires and their mating counterface journal is simulated by testing a small tuft of wire against the outside diameter of a high speed rotating shaft. The test configuration is similar to a standard block on ring geometry. The new tester provides the capability to measure both the friction and wear of candidate wire and counterface materials under controlled loading conditions in the gram to kilogram range. A wide test condition latitude of speeds (1 to 27 m/s), temperatures (25 to 700C), and loads (0.5 to 10 N) enables the simulation of many of the important tribological parameters found in turbine engine brush seals. This paper describes the new test rig and specimen configuration and presents initial data for candidate seal materials comparing tuft test results and wear surface morphology to field tested seal components.

  1. Reintroducing resurrected species: selecting DeExtinction candidates.

    PubMed

    Seddon, Philip J; Moehrenschlager, Axel; Ewen, John

    2014-03-01

    Technological advances have raised the controversial prospect of resurrecting extinct species. Species DeExtinction should involve more than the production of biological orphans to be scrutinized in the laboratory or zoo. If DeExtinction is to realize its stated goals of deep ecological enrichment, then resurrected animals must be translocated (i.e., released within suitable habitat). Therefore, DeExtinction is a conservation translocation issue and the selection of potential DeExtinction candidates must consider the feasibility and risks associated with reintroduction. The International Union for the Conservation of Nature (IUCN) Guidelines on Reintroductions and Other Conservation Translocations provide a framework for DeExtinction candidate selection. We translate these Guidelines into ten questions to be addressed early on in the selection process to eliminate unsuitable reintroduction candidates. We apply these questions to the thylacine, Yangtze River Dolphin, and Xerces blue butterfly.

  2. A New Tribological Test for Candidate Brush Seal Materials Evaluation

    NASA Technical Reports Server (NTRS)

    Fellenstein, James A.; Dellacorte, Christopher

    1994-01-01

    A new tribological test for candidate brush seal materials evaluation has been developed. The sliding contact between the brush seal wires and their mating counterface journal is simulated by testing a small tuft of wire against the outside diameter of a high speed rotating shaft. The test configuration is similar to a standard block on ring geometry. The new tester provides the capability to measure both the friction and wear of candidate wire and counterface materials under controlled loading conditions in the gram to kilogram range. A wide test condition latitude of speeds (1 to 27 m/s), temperatures (25 to 700 C), and loads (0.5 to 10 N) enables the simulation of many of the important tribological parameters found in turbine engine brush seals. This paper describes the new test rig and specimen configuration and presents initial data for candidate seal materials comparing tuft test results and wear surface morphology to field tested seal components.

  3. Counts of low-Redshift SDSS quasar candidates

    SciTech Connect

    Zeljko Ivezic et al.

    2004-03-12

    We analyze the counts of low-redshift quasar candidates selected using nine-epoch SDSS imaging data. The co-added catalogs are more than 1 mag deeper than single-epoch SDSS data, and allow the selection of low-redshift quasar candidates using UV-excess and also variability techniques. The counts of selected candidates are robustly determined down to g = 21.5. This is about 2 magnitudes deeper than the position of a change in the slope of the counts reported by Boyle et al. (1990, 2000) for a sample selected by UV-excess, and questioned by Hawkins & Veron (1995), who utilized a variability-selected sample. Using SDSS data, we confirm a change in the slope of the counts for both UV-excess and variability selected samples, providing strong support for the Boyle et al. results.

  4. MalVac: Database of malarial vaccine candidates

    PubMed Central

    Chaudhuri, Rupanjali; Ahmed, Shakil; Ansari, Faraz Alam; Singh, Harinder Vir; Ramachandran, Srinivasan

    2008-01-01

    Background The sequencing of genomes of the Plasmodium species causing malaria, offers immense opportunities to aid in the development of new therapeutics and vaccine candidates through Bioinformatics tools and resources. Methods The starting point of MalVac database is the collection of known vaccine candidates and a set of predicted vaccine candidates identified from the whole proteome sequences of Plasmodium species provided by PlasmoDb 5.4 release (31st October 2007). These predicted vaccine candidates are the adhesins and adhesin-like proteins from Plasmodium species, Plasmodium falciparum, Plasmodium vivax and Plasmodium yoelii. Subsequently, these protein sequences were analysed through 20 publicly available algorithms to obtain Orthologs, Paralogs, BetaWraps, TargetP, TMHMM, SignalP, CDDSearch, BLAST with Human Ref. Proteins, T-cell epitopes, B-cell epitopes, Discotopes, and allergen predictions. All of this information was collected and organized with the ORFids of the protein sequences as primary keys. This information is relevant from the view point of Reverse Vaccinology in facilitating decision making on the most probable choice for vaccine strategy. Results Detailed information on the patterning of the epitopes and other motifs of importance from the viewpoint of reverse vaccinology has been obtained on the most probable protein candidates for vaccine investigation from three major malarial species. Analysis data are available on 161 adhesin proteins from P. falciparum, 137 adhesin proteins from P. vivax and 34 adhesin proteins from P. yoelii. The results are displayed in convenient tabular format and a facility to export the entire data has been provided. The MalVac database is a "community resource". Users are encouraged to export data and further contribute by value addition. Value added data may be sent back to the community either through MalVac or PlasmoDB. Conclusion A web server MalVac for facilitation of the identification of probable vaccine

  5. PEACE: pulsar evaluation algorithm for candidate extraction - a software package for post-analysis processing of pulsar survey candidates

    NASA Astrophysics Data System (ADS)

    Lee, K. J.; Stovall, K.; 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.

    2013-07-01

    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 labour intensive. In this paper, we introduce an algorithm called Pulsar Evaluation Algorithm for Candidate Extraction (PEACE) 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 Center programme, the statistical performance of PEACE was evaluated. It was found that PEACE ranked 68 per cent of the student-identified pulsars within the top 0.17 per cent of sorted candidates, 95 per cent within the top 0.34 per cent and 100 per cent within the top 3.7 per cent. This clearly demonstrates that PEACE significantly increases the pulsar identification rate by a factor of about 50 to 1000. To date, PEACE has been directly responsible for the discovery of 47 new pulsars, 5 of which are millisecond pulsars that may be useful for pulsar timing based gravitational-wave detection projects.

  6. Dark matter candidates and methods for detecting them

    NASA Technical Reports Server (NTRS)

    Raffelt, G. G.

    1992-01-01

    A number of experiments employing Ge and Si ionization detectors have excluded large regions in the plane of masses and scattering cross-sections for weakly-interacting dark matter (DM) candidates. It is judged that, before a realistic detection experiment for supersymmetric DM candidates can be conducted, significant development efforts will have to be completed for suitable cryogenic or ionization detectors. Pilot experiments have demonstrated the feasibility of axion searches with microwave cavities, but these are at least two orders of magnitude too low in sensitivity.

  7. Dark matter candidates: a ten-point test

    SciTech Connect

    Taoso, Marco; Masiero, Antonio; Bertone, Gianfranco E-mail: bertone@iap.fr

    2008-03-15

    An extraordinarily rich zoo of non-baryonic dark matter candidates has been proposed over the last three decades. Here we present a ten-point test that a new particle has to pass in order to be considered a viable DM candidate. (I) Does it match the appropriate relic density? (II) Is it cold? (III) Is it neutral? (IV) Is it consistent with BBN? (V) Does it leave stellar evolution unchanged? (VI) Is it compatible with constraints on self-interactions? (VII) Is it consistent with direct DM searches? (VIII) Is it compatible with gamma-ray constraints? (IX) Is it compatible with other astrophysical bounds? (X) Can it be probed experimentally?.

  8. Kepler Mission Discovers Trove of Extrasolar Planet Candidates

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2011-02-01

    NASA's Kepler discovery mission is collecting more than just pennies from heaven. Results from the first 4 months of science operations of the Kepler space telescope, announced on 2 February, include the discovery of 1235 candidate planets orbiting 997 stars in a small portion of the Milky Way galaxy examined by the telescope. Follow-up observations likely could confirm about 80% of the candidates as actual planets rather than false positives, according to researchers. This new trove of possible exoplanets could greatly expand the number of known planets outside of our solar system.

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

    ERIC Educational Resources Information Center

    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…

  10. Principals' and Cooperating Teachers' Expectations of Teacher Candidates

    ERIC Educational Resources Information Center

    Bigham, Sarah G.; Hively, Dorothy E.; Toole, Georgiann H.

    2014-01-01

    This study examined public school partners' expectations of teacher candidates and beginning teachers and the qualities that principals consider most important when hiring new teachers. Teachers in Maryland, West Virginia and Virginia (N = 130) responded to 37 Likert-style survey questions based upon the 100 school principals' interview questions…

  11. LJ Q&A "ALA Candidates": Library Advocacy x 2

    ERIC Educational Resources Information Center

    Berry, John N., III

    2008-01-01

    Library advocacy in one of two directions is the top priority of both Camila Alire and J. Linda Williams, the candidates campaigning to capture the 2009-10 term as president of the American Library Association (ALA). Alire, dean emeritus of the libraries of both the University of New Mexico and Colorado State University, will push for enhancements…

  12. Investigation the Technology Usage Level of Teacher Candidates

    ERIC Educational Resources Information Center

    Korucu, Agah Tugrul; Yucel, Ahmet; Gundogdu, Mustafa M.; Gencturk, Tarik A.

    2016-01-01

    Necessity to train individuals who are away from the digital divide that is defined as the gap between the masses who can make use of information technology effectively and who do not have access to information technology due to lack of education (Uckan, 2009). The aim of this study is to analyse the digital competence of teacher candidates in…

  13. The Hidden Curriculum: Candidate Diversity in Educational Leadership Preparation

    ERIC Educational Resources Information Center

    Karanxha, Zorka; Agosto, Vonzell; Bellara, Aarti P.

    2014-01-01

    The authors describe a process of self-assessment attuned to equity and justice in the policies and practices that affect student diversity, namely, those associated with the selection of candidates. The disproportionate rate of rejection for applicants from underrepresented groups and the unsystematic process of applicant selection operated as…

  14. Candidate chemosensory genes in the Stemborer Sesamia nonagrioides.

    PubMed

    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. PMID:23781142

  15. Art, Music, and Movement Connections for Elementary Education Teacher Candidates

    ERIC Educational Resources Information Center

    Bohannon, R. Larry; McDowell, Carol

    2010-01-01

    Visual arts, movement, and music are all connected by common structural elements. The lesson described in this article was prepared so that teacher candidates in elementary education may make connections among music, movement, and the visual arts using an elemental integration approach. This lesson used visual art to introduce the concept of line…

  16. A List of Candidate Cancer Biomarkers for Targeted Proteomics

    PubMed Central

    Polanski, Malu; Anderson, N. Leigh

    2006-01-01

    We have compiled from literature and other sources a list of 1261 proteins believed to be differentially expressed in human cancer. These proteins, only some of which have been detected in plasma to date, represent a population of candidate plasma biomarkers that could be useful in early cancer detection and monitoring given sufficiently sensitive specific assays. We have begun to prioritize these markers for future validation by frequency of literature citations, both total and as a function of time. The candidates include proteins involved in oncogenesis, angiogenesis, development, differentiation, proliferation, apoptosis, hematopoiesis, immune and hormonal responses, cell signaling, nucleotide function, hydrolysis, cellular homing, cell cycle and structure, the acute phase response and hormonal control. Many have been detected in studies of tissue or nuclear components; nevertheless we hypothesize that most if not all should be present in plasma at some level. Of the 1261 candidates only 9 have been approved as “tumor associated antigens” by the FDA. We propose that systematic collection and large-scale validation of candidate biomarkers would fill the gap currently existing between basic research and clinical use of advanced diagnostics. PMID:19690635

  17. Research-Based Teacher Candidate Dispositions Assessment System: Moving Forward

    ERIC Educational Resources Information Center

    Jung, Eunjoo; Larson, Ann E.; Molfese, Victoria J.; Thompson, Charles

    2008-01-01

    Teacher educators, administrators, policy-makers, and novice and advanced teacher candidates can achieve educational success and advance high-quality teacher preparation programmes. To do this, they must identify and cultivate positive dispositions for professional competence, commitment, and success in teaching children and adolescents.…

  18. ANALYTICAL METHOD READINESS FOR THE CONTAMINANT CANDIDATE LIST

    EPA Science Inventory

    The Contaminant Candidate List (CCL), which was promulgated in March 1998, includes 50 chemical and 10 microbiological contaminants/contaminant groups. At the time of promulgation, analytical methods were available for 6 inorganic and 28 organic contaminants. Since then, 4 anal...

  19. Assessment of Law Enforcement Candidates: Peer Evaluations and the MMPI.

    ERIC Educational Resources Information Center

    Schumacher, Joseph E.; Scogin, Forrest

    Screening and evaluating law enforcement candidates for employment as police officers is a complex task. It has been recommended that a clinical interview and comprehensive battery of psychological tests may aid in evaluation. The Minnesota Multiphasic Personality Inventory (MMPI) is often used for this type of psychological screening. Peer…

  20. TECHNICAL BASIS FOR A CANDIDATE BUILDING MATERIALS RADIUM STANDARD

    EPA Science Inventory

    The report summarizes the technical basis for a candidate building materials radium standard. It contains the standard and a summary of the technical basis for the standard. (NOTE: The Florida Radon Research Program (FRRP), sponsored by the Environmental Protection Agency and the...

  1. Further SAO RAS spectral classification of SN candidates.

    NASA Astrophysics Data System (ADS)

    Fatkhullin, T. A.; Moskvitin, A. S.

    2016-08-01

    We observed two SN candidates (AT 2016emj, AT 2016emb) with the BTA/Scorpio-I on the night of August, 3. Direct images in the V band and long-slit spectra in the range of 3600-7600AA (resolution FWHM = 10A) were obtained.

  2. Preparing Teachers for Diverse Learners: Assessing Teacher Candidates' Dispositions

    ERIC Educational Resources Information Center

    Northington, Vera Ann

    2011-01-01

    The National Council for Accreditation for Teacher Education (NCATE) recommended teacher preparation programs measure teacher candidates' disposition toward diverse learners. The conduction of the quantitative cross-sectional survey design utilized the Quick Discrimination Index Survey (QDI), a Likert-type tool that used reversed or negatively…

  3. From Teacher Candidates to ESL Ambassadors in Teacher Education

    ERIC Educational Resources Information Center

    Schmidt, Clea

    2005-01-01

    This paper analyzes the process and impact of a pre-service teacher education course assignment that engaged teacher candidates in developing and delivering an ESL professional development night for faculty colleagues and teachers from the field. The night involved a reader's theatre performance and follow-up discussion of Tara Goldstein's (2003)…

  4. Developing the "Pedagogical Efficacy Perception Scale" for Teacher Candidates

    ERIC Educational Resources Information Center

    Akbaba, Ahmet

    2015-01-01

    This study aims to develop the "Pedagogical Efficacy Perception Scale" for teacher candidates and to compare scale scores. The sample of this survey model study consists of 310 students studying in a faculty of education. The "Pedagogical Efficacy Perception Scale" developed by the author was used for data collection.…

  5. Effects of a Presidential Candidate's Comments on HPV Vaccine.

    PubMed

    Zucker, Rachel A; Reiter, Paul L; Mayer, Melissa K; Brewer, Noel T

    2015-01-01

    During and after the 2011 Republican presidential debate, a candidate questioned the safety of HPV vaccine. The authors aimed to determine the effect of these comments on parents. A national sample of 327 parents with adolescent sons ages 11-17 years completed online surveys in fall 2010 (baseline, about 1 year before the debate) and 2011 (follow-up, about 1 month after the debate). The authors used regression models to examine the association of parents' awareness of the candidate's comments with HPV vaccine initiation among their sons, their willingness to get sons free HPV vaccine, and their beliefs about potential harms of HPV vaccine. Overall, 17% of parents reported hearing about the Republican presidential candidate's comments about HPV vaccine. Parents aware of the comments had a larger increase between baseline and follow-up in the belief that HPV vaccine might cause short-term health problems compared with parents who were not aware. Although the candidate's comments may have increased some parents' beliefs about the short-term harms of HPV vaccine, the comments had no effect on other beliefs, willingness to vaccinate, or behavior. Having accurate information about HPV vaccine that is readily available to the public during such controversies may diminish their effect. PMID:25950109

  6. Teacher Candidates' Opinions on Erasmus Student Exchange Program

    ERIC Educational Resources Information Center

    Unlu, Ihsan

    2015-01-01

    This study contains teacher candidates' opinions who spent a portion of their educational career abroad as participants in the Erasmus Program regarding the academic, cultural, and personal gains of the program. Using the Quantitative Research Method, this study focuses on phenomena that researchers are aware of, but on which they do not have…

  7. Linguistic and Cultural Adaptation of Internationally Educated Teacher Candidates

    ERIC Educational Resources Information Center

    Faez, Farahnaz

    2010-01-01

    This paper reports on findings of a qualitative study that explored the experiences, needs and challenges of internationally educated teacher candidates (IETCs) in a large metropolitan university in Canada. Interviews were conducted with IETCs as well as the teacher educator working with them. Findings revealed that IETCs required additional…

  8. Developing a Framework for the Assessment of Teacher Candidate Dispositions.

    ERIC Educational Resources Information Center

    Mullin, Doug

    The joint Education Department of the College of Saint Benedict and Saint John's University, Minnesota, developed a behaviorally oriented framework for assessing teacher candidate dispositions. They created an instrument to use in a behavioral assessment of all applicants to the teacher education program. This assessment involved an interview with…

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

    ERIC Educational Resources Information Center

    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…

  10. Encouraging Agitation: Teaching Teacher Candidates to Confront Words that Wound

    ERIC Educational Resources Information Center

    Staples, Jeanine M.

    2010-01-01

    In this analytic conceptual essay, and from her standpoint as an African American woman teacher/researcher, the author presents a rich description of a personal sensibility and promising professional practice for literacy educators and those who prepare Reading/English/Language Arts teacher candidates for service among students who are…

  11. GOP Candidates Eye Scaling Back Federal K-12 Role

    ERIC Educational Resources Information Center

    Klein, Alyson

    2012-01-01

    Though education has played second fiddle so far to other domestic issues in the race for the Republican presidential nomination, the narrowing field includes GOP candidates with compatible views on scaling back the federal role in K-12, but big contrasts in policy specifics and experience. President Barack Obama, meanwhile, is expected to put a…

  12. Identifying and Assessing Dispositions of Educational Leadership Candidates

    ERIC Educational Resources Information Center

    Melton, Teri; Mallory, Barbara J.; Green, James

    2010-01-01

    The purpose of this study was to identify educational leadership programs' procedures for the identification and assessment of leadership dispositions. The findings of this cross sectional survey indicated that there is little consistency in practice in defining and assessing dispositions of leadership candidates. While findings indicated that the…

  13. Cardiovascular risk assessment of the liver transplant candidate.

    PubMed

    Raval, Zankhana; Harinstein, Matthew E; Skaro, Anton I; Erdogan, Ata; DeWolf, Andre M; Shah, Sanjiv J; Fix, Oren K; Kay, Nina; Abecassis, Michael I; Gheorghiade, Mihai; Flaherty, James D

    2011-07-12

    Liver transplantation (LT) candidates today are increasingly older, have greater medical acuity, and have more cardiovascular comorbidities than ever before. Steadily rising model for end-stage liver disease (MELD) scores at the time of transplant, resulting from high organ demand, reflect the escalating risk profiles of LT candidates. In addition to advanced age and the presence of comorbidities, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Patients with cirrhosis requiring LT usually demonstrate increased cardiac output and a compromised ventricular response to stress, a condition termed cirrhotic cardiomyopathy. These cardiac disturbances are likely mediated by decreased beta-agonist transduction, increased circulating inflammatory mediators with cardiodepressant properties, and repolarization changes. Low systemic vascular resistance and bradycardia are also commonly seen in cirrhosis and can be aggravated by beta-blocker use. These physiologic changes all contribute to the potential for cardiovascular complications, particularly with the altered hemodynamic stresses that LT patients face in the immediate post-operative period. Post-transplant reperfusion may result in cardiac death due to a multitude of causes, including arrhythmia, acute heart failure, and myocardial infarction. Recognizing the hemodynamic challenges encountered by LT patients in the perioperative period and how these responses can be exacerbated by underlying cardiac pathology is critical in developing recommendations for the pre-operative risk assessment and management of these patients. The following provides a review of the cardiovascular challenges in LT candidates, as well as evidence-based recommendations for their evaluation and management.

  14. Preparing Teacher Candidates for Family-School Partnerships

    ERIC Educational Resources Information Center

    de Bruïne, Erica J.; Willemse, T. Martijn; D'Haem, Jeanne; Griswold, Peter; Vloeberghs, Lijne; van Eynde, Sofie

    2014-01-01

    Previous research indicates that, while parent involvement promotes student achievement, how teacher candidates are prepared to establish family-school partnerships (FSP) is not well documented and the roles of teacher educators are often neglected. Explorative studies including curriculum analysis and focus groups of primary and secondary teacher…

  15. Health Potential of Female Candidates to the Professional Military Service

    ERIC Educational Resources Information Center

    Kaiser, Alicja; Sokolowski, Marek

    2011-01-01

    Study aim: To assess health and social characteristics of female candidates for professional officers and non-commissioned officers of Polish Army. Material and methods: All female students of officer and non-commissioned officer Military Academies (16 each) were studied in 2009. Two questionnaires were applied in the study: IPAQ (short) for…

  16. Community Arts and Teacher Candidates: A Study in Civic Engagement

    ERIC Educational Resources Information Center

    Briggs, Judith; McHenry, Kimberly

    2013-01-01

    Within an afterschool community arts program for underserved children, teacher candidates tested prescribed teaching methods, experimented with teaching styles, and worked cooperatively with peers and faculty to enhance the children's creativity and sense of accomplishment. Students connected theoretical classroom knowledge to real-world…

  17. Documenting Teacher Candidates' Professional Growth through Performance Evaluation

    ERIC Educational Resources Information Center

    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,…

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

    ERIC Educational Resources Information Center

    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…

  19. Progenitor Candidate for SN 2016gkg in NGC 613

    NASA Astrophysics Data System (ADS)

    Kilpatrick, C. D.; Siebert, M. R.; Foley, R. J.; Max, C. E.; Williams, P.; Abramson, L. E.; Lu, C.-X.; Treu, T.; Kassis, M.

    2016-09-01

    We have identified a candidate progenitor star of the Type II SN 2016gkg in NGC 613 (ATel #9521, #9526, #9528, #9529) in archival Hubble Space Telescope (HST) WFPC2 images in the F450W, F606W, and F814W filters.

  20. Assessing Teacher Candidate Growth over Time: Embedded Signature Assessments

    ERIC Educational Resources Information Center

    Larsen, Lynn R.; Calfee, Robert C.

    2005-01-01

    In 1998, California state legislation called for significant reform in the preparation of teachers. As a result, institutions of higher learning must now conduct a formal performance-based assessment. All teacher candidates must participate in the assessment at the end of the program for receipt of the preliminary teaching credential. The…

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

    PubMed

    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.

  2. AN EFFICIENT AUTOMATED VALIDATION PROCEDURE FOR EXOPLANET TRANSIT CANDIDATES

    SciTech Connect

    Morton, Timothy D.

    2012-12-10

    Surveys searching for transiting exoplanets have found many more candidates than they have been able to confirm as true planets. This situation is especially acute with the Kepler survey, which has found over 2300 candidates but has to date confirmed only a small fraction of them as planets. I present here a general procedure that can quickly be applied to any planet candidate to calculate its false positive probability. This procedure takes into account the period, depth, duration, and shape of the signal; the colors of the target star; arbitrary spectroscopic or imaging follow-up observations; and informed assumptions about the populations and distributions of field stars and multiple-star properties. Applying these methods to a sample of known Kepler planets, I demonstrate that many signals can be validated with very limited follow-up observations: in most cases with only a spectrum and an adaptive optics image. Additionally, I demonstrate that this procedure can reliably identify false positive signals. Because of the computational efficiency of this analysis, it is feasible to apply it to all Kepler planet candidates in the near future, and it will streamline the follow-up efforts for Kepler and other current and future transit surveys.

  3. Supporting Clinical Practice Candidates in Learning Community Development

    ERIC Educational Resources Information Center

    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…

  4. Primary School Teacher Candidates' Geometric Habits of Mind

    ERIC Educational Resources Information Center

    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…

  5. Pre-discovery confirmation of M81 nova candidate

    NASA Astrophysics Data System (ADS)

    Henze, M.; Sala, G.; Jose, J.; Figueira, J.; Hernanz, M.

    2016-10-01

    We confirm the discovery of a new nova candidate in the M81 galaxy (announced in ATel #9605) on 12x200s stacked R filter CCD images, obtained on 2016-10-08.05 UT. This date is 0.2 d prior to the discovery date given in ATel #9605.

  6. NEW YOUNG STAR CANDIDATES IN BRC 27 AND BRC 34

    SciTech Connect

    Rebull, L. M.; Laher, R.; Legassie, M.; Gibbs, J. C.; Aryal, S.; Canakapalli, T. S.; Linahan, M.; Ezyk, N.; Fagan, J.; Sartore, D.; Badura, K. S.; Armstrong, J. D.; Allen, L. E.; McGehee, P.; and others

    2013-01-01

    We used archival Spitzer Space Telescope mid-infrared data to search for young stellar objects (YSOs) in the immediate vicinity of two bright-rimmed clouds, BRC 27 (part of CMa R1) and BRC 34 (part of the IC 1396 complex). These regions both appear to be actively forming young stars, perhaps triggered by the proximate OB stars. In BRC 27, we find clear infrared excesses around 22 of the 26 YSOs or YSO candidates identified in the literature, and identify 16 new YSO candidates that appear to have IR excesses. In BRC 34, the one literature-identified YSO has an IR excess, and we suggest 13 new YSO candidates in this region, including a new Class I object. Considering the entire ensemble, both BRCs are likely of comparable ages, within the uncertainties of small number statistics and without spectroscopy to confirm or refute the YSO candidates. Similarly, no clear conclusions can yet be drawn about any possible age gradients that may be present across the BRCs.

  7. Teacher Candidates' Collaboration and Identity in Online Discussions

    ERIC Educational Resources Information Center

    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…

  8. Assessment of Teacher Candidate Dispositions: Evidence of Reliability and Validity

    ERIC Educational Resources Information Center

    Choi, Hee-sook; Benson, Nicholas F.; Shudak, Nicholas J.

    2016-01-01

    The current study is an attempt to inform professionals, such as university trainers and field-based supervisors, as to the utility of professional dispositions assessment as a means of gauging teacher candidate success in their professional roles. According to the "Standards for Educational and Psychological Testing" (2014), test users…

  9. Journey of "Becoming": Secondary Teacher Candidates' Concerns and Struggles

    ERIC Educational Resources Information Center

    Cooper, Jewell E.; He, Ye

    2012-01-01

    As is widely recognized in the teacher education field, it is a complex process for teacher candidates to become effective classroom teachers. With growing linguistic and cultural diversity in today's classrooms, as well as different social expectations for education, the teacher preparation process is becoming increasingly demanding and…

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

    ERIC Educational Resources Information Center

    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…

  11. What Rural Superintendents in Ohio Value in New Teacher Candidates

    ERIC Educational Resources Information Center

    Smith, Richard D., Jr.

    2012-01-01

    The purpose of this study was to have a better understanding of what rural superintendents are looking for in new first-year teachers, and to provide that information to future teaching candidates and colleges of education that are preparing teachers for the 21st Century classroom. Over the past twenty years, superintendents have not changed in…

  12. Career Hints for the Doctoral Candidate Interested in Teacher Education.

    ERIC Educational Resources Information Center

    Frith, Greg

    Guidelines are given to aid doctoral candidates in the selection of a specific career position within the field of teacher education. Various considerations relative to employment at differing types of universities are examined. University philosophy, monetary considerations, communication channels within the department, faculty relationships,…

  13. The Impact of Notebooking on Teacher Candidates' Construction of Knowledge

    ERIC Educational Resources Information Center

    Mohr, Jennifer A.; Raisor, Jill M.; Thomas, Jeff A.

    2014-01-01

    Teacher education preparation programs must adapt to changing science education reform movements that identify notebooking as an effective means to increase children's' science process skills and content knowledge. This study addresses the question, "What are the structures and thinking processes that teacher candidates utilize when writing…

  14. Single transit candidates from K2: detection and period estimation

    NASA Astrophysics Data System (ADS)

    Osborn, H. P.; Armstrong, D. J.; 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.

    2016-04-01

    Photometric surveys such as Kepler have the precision to identify exoplanet and eclipsing binary candidates from only a single transit. K2, with its 75 d 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 seven 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} d and a radius of 0.51 ± 0.05RJup. 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 detection of planets in reach of confirmation by Gaia.

  15. Identity Development among Pre-Service Teacher Candidates

    ERIC Educational Resources Information Center

    Lerseth, Kathryn Ann

    2013-01-01

    This case study examined teacher identity development among four pre-service teacher candidates during their student teaching experience. Guided by three complementary theoretical frameworks for investigating teacher professional identities (e.g., Gee, 2000-2001; Beijaard, Meijer, & Verloop; 2004; Moje & Luke, 2009), the study focused on…

  16. MULTIWAVELENGTH OBSERVATIONS OF MASSIVE STELLAR CLUSTER CANDIDATES IN THE GALAXY

    SciTech Connect

    Richards, Emily E.; Lang, Cornelia C.; Trombley, Christine; Figer, Donald F. E-mail: er7@indiana.edu

    2012-09-01

    The Galaxy appears to be richer in young, massive stellar clusters than previously known, due to advances in infrared surveys that have uncovered deeply embedded regions of star formation. Young, massive clusters can significantly impact the surrounding interstellar medium (ISM) and hence radio observations can also be an important tracer of their activity. Several hundred cluster candidates are now known by examining survey data. Here, we report on multiwavelength observations of six of these candidates in the Galaxy. We carried out 4.9 and 8.5 GHz Very Large Array observations of the radio emission associated with these clusters to obtain the physical characteristics of the surrounding gas, including the Lyman continuum photon flux and ionized gas mass. Spitzer Infrared Array Camera observations were also made of these regions, and provide details on the stellar population as well as the dust continuum and polycyclic aromatic hydrocarbon emission. When compared to the known young, massive clusters in the Galaxy, the six cluster candidates have less powerful Lyman ionizing fluxes and ionize less of the H II mass in the surrounding ISM. Therefore, these cluster candidates appear to be more consistent with intermediate-mass clusters (10{sup 3}-10{sup 4} M{sub Sun }).

  17. Teacher Candidates' Transformative Thinking on Issues of Social Justice

    ERIC Educational Resources Information Center

    Frederick, Rona; Cave, Agnes; Perencevich, Kathleen C.

    2010-01-01

    This article examined how teacher candidates' thoughts shifted regarding social inequity in a sophomore-level Foundations of Education course located in the mid-Atlantic region of the United States. First, we described in detail the teacher education program and course, as well as class simulations, school observations, course readings and class…

  18. Assessing School Principal Candidates: Perspectives of the Hiring Superintendents

    ERIC Educational Resources Information Center

    Kwan, Paula

    2012-01-01

    This paper examines the criteria used by recruiting bodies to assess potential candidates for the post of principal of a secondary school in Hong Kong. A quantitative methodology is used to identify what recruiters seek in applicants. The expectations that recruiters have when assessing applicants can be seen as a form of proxy for the elements…

  19. Organizing a Congressional Candidate Debate as Experiential Learning

    ERIC Educational Resources Information Center

    Boeckelman, Keith; Deitz, Janna L.; Hardy, Richard J.

    2008-01-01

    This article describes a political debate among congressional candidates that the authors organized in 2006. The debate was structured to maximize student involvement both in the planning stages and during the event itself. After discussing relevant literature on experiential learning, the article describes the debate format and details the issues…

  20. 28 CFR 105.14 - Risk assessment for candidates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Risk assessment for candidates. 105.14 Section 105.14 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) CRIMINAL HISTORY BACKGROUND CHECKS Aviation Training for Aliens and Other Designated Individuals § 105.14 Risk assessment...

  1. 28 CFR 105.14 - Risk assessment for candidates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Risk assessment for candidates. 105.14 Section 105.14 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) CRIMINAL HISTORY BACKGROUND CHECKS Aviation Training for Aliens and Other Designated Individuals § 105.14 Risk assessment...

  2. 28 CFR 105.14 - Risk assessment for candidates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Risk assessment for candidates. 105.14 Section 105.14 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) CRIMINAL HISTORY BACKGROUND CHECKS Aviation Training for Aliens and Other Designated Individuals § 105.14 Risk assessment...

  3. Association of candidate genes with antisocial drug dependence in adolescents

    PubMed Central

    Corley, Robin P.; Zeiger, Joanna S.; Crowley, Thomas; Ehringer, Marissa A.; Hewitt, John K.; Hopfer, Christian J.; Lessem, Jeffrey; McQueen, Matthew B.; Rhee, Soo Hyun; Smolen, Andrew; Stallings, Michael C.; Young, Susan E.; Krauter, Kenneth

    2008-01-01

    The Colorado Center for Antisocial Drug Dependence (CADD) is using several research designs and strategies in its study of the genetic basis for antisocial drug dependence in adolescents. This study reports Single Nucleotide Polymorphism (SNP) association results from a Targeted Gene Assay (SNP chip) of 231 Caucasian male probands in treatment with antisocial drug dependence and a matched set of community controls. The SNP chip was designed to assay 1500 SNPs distributed across 50 candidate genes that have had associations with substance use disorders and conduct disorder. There was an average gene-wide inter-SNP interval of 3000 base pairs. After eliminating SNPs with poor signals and low minor allele frequencies, 60 nominally significant associations were found among the remaining 1073 SNPs in 18 of 49 candidate genes. Although none of the SNPs achieved genome-wide association significance levels (defined as p < .000001), two genes probed with multiple SNPs (OPRM1 and CHRNA2) emerged as plausible candidates for a role in antisocial drug dependence after gene-based permutation tests. The custom-designed SNP chip served as an effective and flexible platform for rapid interrogation of a large number of plausible candidate genes. PMID:18384978

  4. Building a Sound Rationale for Teaching among Preservice Teacher Candidates.

    ERIC Educational Resources Information Center

    Veronesi, Peter D.; Varrella, Gary F.

    This paper reports on the perceptions of preservice teacher candidates (students) regarding their personal content- and context-specific pedagogies toward a strategy that promotes the development of these important teaching abilities; the elementary science teaching rationale. Perceptions about a science teaching rationale were surveyed at the end…

  5. A Comparative Study of 1985 and 1991 Teacher Education Candidates.

    ERIC Educational Resources Information Center

    Sultana, Qaisar; Wirtz, Paul

    This study compared 1985 and 1991 teacher education candidates on three different measures, to determine whether students entering the teaching profession today are qualitatively different from those in the past. One hundred essays written by preservice students at the College of Education at Eastern Kentucky University in 1985 and 1991 were…

  6. Physical Education Teachers' and Teacher Candidates' Attitudes toward Cultural Pluralism

    ERIC Educational Resources Information Center

    Columna, Luis; Foley, John T.; Lytle, Rebecca K.

    2010-01-01

    The purpose of this study was to analyze both male and female physical education teacher attitudes toward cultural pluralism and diversity. Participants (N = 433)were adapted physical education specialists, physical education generalists, and teacher candidates. The research method was a descriptive cross-sectional survey (Fraenkel & Wallen,…

  7. Official portrait of 1987 astronaut candidate Kenneth D. Bowersox

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Official portrait of 1987 astronaut candidate Kenneth D. Bowersox. Bowersox, a member of the United States Navy (USN) and Astronaut Class 12, wears navy blue flight suit and holds space shuttle orbiter model with external tank (ET) and solid rocket boosters (SRBs).

  8. Investigating Change in Field Sites through Mentor and Candidate Dialogues

    ERIC Educational Resources Information Center

    Kroeger, Janice; Pech, Sandra; Cope, Jennifer

    2009-01-01

    The work of teacher candidates matters in particular ways to the quality of children's experiences and environments when they teach in preschools. We conducted a mixed-method study with survey, interviews, focus groups, and photographic documentation of classroom spaces, and theorized findings through Bahktin's dialogism and the notion of figured…

  9. BACTERIAL PATHOGENIC RESEARCH IN RESPONSE TO CONTAMINANT CANDIDATE LIST NEEDS

    EPA Science Inventory

    The Safe Drinking Water Act, as amended in 1996, requires EPA to establish a Contaminant Candidate List (CCL) of unregulated microbiological and chemical contaminants to aid in priority setting for the Agency's drinking water program. At predetermined intervals the Agency must s...

  10. Conceptual Clarity and Connections: Global Education and Teacher Candidates

    ERIC Educational Resources Information Center

    Reimer, Kristin; McLean, Lorna R.

    2009-01-01

    In this article, we have explored the experiences of students in a teacher education programme designed to promote the effective teaching of global education. Research to date indicates that, although interest is high among teacher candidates, they often lack confidence in their abilities to bring global education into their future classrooms. By…

  11. Candidates in Educational Leadership Graduate Programs. Implications from UCEA

    ERIC Educational Resources Information Center

    University Council for Educational Administration, 2011

    2011-01-01

    In 2009, an essential new Handbook was published by UCEA, the "Handbook of Research on the Education of School Leaders." The handbook provides a rich resource for researchers, policy makers and those who prepare educational leaders. The chapter discussed in this issue of "Implications" addresses the leadership candidates enrolled in educational…

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

    PubMed

    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. PMID:25811414

  13. Candidate New Rotavirus Species in Sheltered Dogs, Hungary

    PubMed Central

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

    2015-01-01

    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. PMID:25811414

  14. "Wishes" the Teacher Candidates Expressed in Communication with Themselves

    ERIC Educational Resources Information Center

    Çaliskan, Nihat

    2014-01-01

    The purpose of this study is to identify "the wish sentences" that teacher candidates create in the communication with themselves. The case study which is one of the type of qualitative research is utilized in this study. The study group is formed by 320 students studying in a university in central Anatolia. Data were collected by the…

  15. Near-infrared survey of high mass X-ray binary candidates

    NASA Astrophysics Data System (ADS)

    Torrejón, J. M.; Negueruela, I.; Smith, D. M.; Harrison, T. E.

    2010-02-01

    Context. The INTEGRAL satellite is detecting a large population of new X-ray sources that were missed by previous missions because of high obscuration and, in some cases, very short duty cycles. The nature of these sources must be addressed by characterizing their optical and/or infrared counterparts. Aims: We investigate the nature of the optical counterparts to five of these newly discovered X-ray sources. Methods: We combine infrared spectra in the I, J,H, and K bands with JHK photometry to characterize the spectral type, luminosity class, and distance to the infrared counterparts to these systems. For IGR J19140+0951, we present spectroscopy from the red to the K band and new red and infrared photometry. For SAX J18186-1703 and IGR J18483-0311, we present the first intermediate-resolution spectroscopy to be published. Finally, for IGR J18027-2016, we present new I and K band spectra. Results: We find that four systems harbour early-type B supergiants. All of them are heavily obscured, with E(B-V) ranging between 3 and 5, implying visual extinctions of ~ 9 to 15 mag. We refine the published classifications of IGR J18027-2016 and IGR J19140+0951 by constraining their luminosity class. In the first case, we confirm the supergiant nature but exclude a class III. In the second case, we propose a slightly higher luminosity class (Ia instead of Iab) and provide an improved value of the distance based on new optical photometry. Two other systems, SAX J18186-1703 and IGR J18483-0311 are classified as supergiant fast X-ray transients (SFXTs). XTE J1901+014, on the other hand, contains no bright infrared source in its error circle. Conclusions: Owing to their infrared and X-ray characteristics, IGR J18027-2016 and IGR J19140+0951, emerge as supergiant X-ray binaries with X-ray luminosities of the order of L_X˜ [1-2]× 1036 erg s-1, while SAX J1818.6-1703 and IGR J18483-0311, are found to be SFXTs at 2 and 3 kpc, respectively. Finally, XTE J1901+014 emerges as a puzzling

  16. Immunoproteomic Analysis of Potential Serum Biomarker Candidates in Human Glaucoma

    PubMed Central

    Tezel, Gülgün; Thornton, Ivey L.; Tong, Melissa G.; Luo, Cheng; Yang, Xiangjun; Cai, Jian; Powell, David W.; Soltau, Joern B.; Liebmann, Jeffrey M.; Ritch, Robert

    2012-01-01

    Purpose. Evidence supporting the immune system involvement in glaucoma includes increased titers of serum antibodies to retina and optic nerve proteins, although their pathogenic importance remains unclear. This study using an antibody-based proteomics approach aimed to identify disease-related antigens as candidate biomarkers of glaucoma. Methods. Serum samples were collected from 111 patients with primary open-angle glaucoma and an age-matched control group of 49 healthy subjects without glaucoma. For high-throughput characterization of antigens, serum IgG was eluted from five randomly selected glaucomatous samples and analyzed by linear ion trap mass spectrometry (LC-MS/MS). Serum titers of selected biomarker candidates were then measured by specific ELISAs in the whole sample pool (including an additional control group of diabetic retinopathy). Results. LC-MS/MS analysis of IgG elutes revealed a complex panel of proteins, including those detectable only in glaucomatous samples. Interestingly, many of these antigens corresponded to upregulated retinal proteins previously identified in glaucomatous donors (or that exhibited increased methionine oxidation). Moreover, additional analysis detected a greater immunoreactivity of the patient sera to glaucomatous retinal proteins (or to oxidatively stressed cell culture proteins), thereby suggesting the importance of disease-related protein modifications in autoantibody production/reactivity. As a narrowing-down strategy for selection of initial biomarker candidates, we determined the serum proteins overlapping with the retinal proteins known to be up-regulated in glaucoma. Four of the selected 10 candidates (AIF, cyclic AMP-responsive element binding protein, ephrin type-A receptor, and huntingtin) exhibited higher ELISA titers in the glaucomatous sera. Conclusions. A number of serum proteins identified by this immunoproteomic study of human glaucoma may represent diseased tissue-related antigens and serve as candidate

  17. Analysis of candidate genes for macular telangiectasia type 2

    PubMed Central

    Parmalee, Nancy L.; Schubert, Carl; Merriam, Joanna E.; Allikmets, Kaija; Bird, Alan C.; Gillies, Mark C.; Peto, Tunde; Figueroa, Maria; Friedlander, Martin; Fruttiger, Marcus; Greenwood, John; Moss, Stephen E.; Smith, Lois E.H.; Toomes, Carmel; Inglehearn, Chris F.

    2010-01-01

    Purpose To find the gene(s) responsible for macular telangiectasia type 2 (MacTel) by a candidate-gene screening approach. Methods Candidate genes were selected based on the following criteria: those known to cause or be associated with diseases with phenotypes similar to MacTel, genes with known function in the retinal vasculature or macular pigment transport, genes that emerged from expression microarray data from mouse models designed to mimic MacTel phenotype characteristics, and genes expressed in the retina that are also related to diabetes or hypertension, which have increased prevalence in MacTel patients. Probands from eight families with at least two affected individuals were screened by direct sequencing of 27 candidate genes. Identified nonsynonymous variants were analyzed to determine whether they co-segregate with the disease in families. Allele frequencies were determined by TaqMan analysis of the large MacTel and control cohorts. Results We identified 23 nonsynonymous variants in 27 candidate genes in at least one proband. Of these, eight were known single nucleotide polymorphisms (SNPs) with allele frequencies of >0.05; these variants were excluded from further analyses. Three previously unidentified missense variants, three missense variants with reported disease association, and five rare variants were analyzed for segregation and/or allele frequencies. No variant fulfilled the criteria of being causal for MacTel. A missense mutation, p.Pro33Ser in frizzled homolog (Drosophila) 4 (FZD4), previously suggested as a disease-causing variant in familial exudative vitreoretinopathy, was determined to be a rare benign polymorphism. Conclusions We have ruled out the exons and flanking intronic regions in 27 candidate genes as harboring causal mutations for MacTel. PMID:21179236

  18. Discovery of optical candidate supernova remnants in Sagittarius

    NASA Astrophysics Data System (ADS)

    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.

  19. NEW DEBRIS DISK CANDIDATES AROUND 49 NEARBY STARS

    SciTech Connect

    Koerner, D. W.; Kim, S.; Trilling, D. E.; Larson, H.; Cotera, A.; Stapelfeldt, K. R.; Wahhaj, Z.; Fajardo-Acosta, S.; Padgett, D.; Backman, D.

    2010-02-10

    We present 49 new candidate debris disks that were detected around nearby stars with the Spitzer Space Telescope using the Multiband Imaging Photometer (MIPS) at 24 {mu}m (MIPS24) and 70 {mu}m (MIPS70). The survey sample was composed of stars within 25 pc of the Sun that were not previously observed by any other MIPS survey. Only stars with V < 9 were selected, corresponding to spectral types earlier than M0. MIPS24 integration times were chosen to detect the stellar photosphere at 10{sigma} levels or better. MIPS70 observations were designed to detect excess infrared emission from any star in the MIPS70 sample with a disk as luminous at that around {epsilon} Eridani. The resulting sample included over 436 nearby stars that were observed with both MIPS24 and MIPS70, plus an additional 198 observed only with MIPS24. Debris disk candidates were defined as targets where excess emission was detected at 3{sigma} levels or greater, and the ratio of observed flux density to expected photosphere emission was three standard deviations or more above the mean value for the sample. The detection rate implied by the resulting 29 MIPS24 candidates is 4.6%. A detection rate of 4.8% is implied by 21 MIPS70 candidates. The distribution of spectral types for stars identified as candidates resembles that of the general sample and yields strong evidence that debris-disk occurrence does not decrease for K dwarfs. Modeling of non-uniform sensitivity in the sample is required to interpret quantitative estimates of the overall detection frequency and will be presented in a future work.

  20. Identification of genes from the Treacher Collins candidate region

    SciTech Connect

    Dixon, M.; Dixon, J.; Edwards, S. |

    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.

  1. A Research on the Burnout and the Teaching Profession Attitudes of Teacher Candidates

    ERIC Educational Resources Information Center

    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…

  2. Framing the Candidates in Presidential Primaries: Issues and Images in Press Releases and News Coverage.

    ERIC Educational Resources Information Center

    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…

  3. Comparing What Teacher Candidates Know about Each Other: China and the United States

    ERIC Educational Resources Information Center

    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…

  4. Automatic extraction of candidate nomenclature terms using the doublet method

    PubMed Central

    Berman, Jules J

    2005-01-01

    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 nomenclature. Results A 31

  5. The Planck Catalogue of High-z source candidates

    NASA Astrophysics Data System (ADS)

    Montier, Ludovic

    2015-08-01

    The Planck satellite has provided the first FIR/submm all-sky survey with a sensitivity allowing us to identify the rarest, most luminous high-z dusty star-forming sources on the sky. It opens a new window on these extreme star-forming systems at redshift above 1.5, providing a powerful laboratory to study the mechanisms of galaxy evolution and enrichment in the frame of the large scale structure growth.I will describe how the Planck catalogue of high-z source candidates (PHz, Planck 2015 in prep.) has been built and charcaterized over 25% of the sky by selecting the brightest red submm sources at a 5' resolution. Follow-up observations with Herschel/SPIRE over 228 Planck candidates have shown that 93% of these candidates are actually overdensities of red sources with SEDs peaking at 350um (Planck Int. results. XXVII 2014). Complementarily to this population of objects, 12 Planck high-z candidates have been identified as strongly lensed star forming galaxies at redshift lying between 2.2 and 3.6 (Canameras et al 2015 subm.), with flux densities larger than 400 mJy up to 1 Jy at 350um, and strong magnification factors. These Planck lensed star-forming galaxies are the rarest brightest lensed in the submm range, providing a unique opportunity to extend the exploration of the star-forming system in this range of mass and redshift.I will detail further a specific analysis performed on a proto-cluster candidate, PHz G95.5-61.6, identified as a double structure at z=1.7 and z=2.03, using an extensive follow-up program (Flores-Cacho et al 2015 subm.). This is the first Planck proto-cluster candidate with spectroscopic confirmation, which opens a new field of statistical analysis about the evolution of dusty star-forming galaxies in such accreting structures.I will finally discuss how the PHz catalogue may help to answer some of the fundamental questions like: At what cosmic epoch did massive galaxy clusters form most of their stars? Is star formation more or less vigorous

  6. Abrasion of Candidate Spacesuit Fabrics by Simulated Lunar Dust

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Meador, Mary Ann; Rogers, Kerry J.; Sheehy, Brennan H.

    2009-01-01

    A protocol has been developed that produced the type of lunar soil abrasion damage observed on Apollo spacesuits. This protocol was then applied to four materials (Kevlar (DuPont), Vectran (Kuraray Co., Ltd.), Orthofabric, and Tyvek (DuPont)) that are candidates for advanced spacesuits. Three of the four new candidate fabrics (all but Vectran) were effective at keeping the dust from penetrating to layers beneath. In the cases of Kevlar and Orthofabric this was accomplished by the addition of a silicone layer. In the case of Tyvek, the paper structure was dense enough to block dust transport. The least abrasive damage was suffered by the Tyvek. This was thought to be due in large part to its non-woven paper structure. The woven structures were all abraded where the top of the weave was struck by the abrasive. Of these, the Orthofabric suffered the least wear, with both Vectran and Kevlar suffering considerably more extensive filament breakage.

  7. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    PubMed

    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.

  8. Identifying False Alarms in the Kepler Planet Candidate Catalog

    NASA Astrophysics Data System (ADS)

    Mullally, F.; Coughlin, Jeffery L.; Thompson, Susan E.; Christiansen, Jessie; Burke, Christopher; Clarke, Bruce D.; Haas, Michael R.

    2016-07-01

    We present a new automated method to identify instrumental features masquerading as small, long-period planets in the Kepler planet candidate catalog. These systematics, mistakenly identified as planet transits, can have a strong impact on occurrence rate calculations because they cluster in a region of parameter space where Kepler’s sensitivity to planets is poor. We compare individual transit-like events to a variety of models of real transits and systematic events and use a Bayesian information criterion to evaluate the likelihood that each event is real. We describe our technique and test its performance on simulated data. Results from this technique are incorporated in the Kepler Q1–Q17 DR24 planet candidate catalog of Coughlin et al.

  9. Determination of candidate subjects for better recognition of faces

    NASA Astrophysics Data System (ADS)

    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.

  10. Deprotonated Polycyclic Aromatic Hydrocarbons as Candidate Anomalous Microwave Emission Carriers

    NASA Astrophysics Data System (ADS)

    Hammonds, Mark; Bell, Aaron Christopher; Candian, Alessandra; Sarre, Peter; Onaka, Takashi

    2015-08-01

    Anomalous microwave emission (AME) is a major puzzle in studies of the interstellar medium. The precise nature of the AME carrier is still a matter of active research and studies to identify candidate species are important in understanding how AME relates to other chemical and physical processes occurring within the interstellar medium. This work presents deprotonated polycyclic aromatic hydrocarbons, a variety of large anionic carbonaceous molecules with strong permanent electric dipole moments, as potential candidate AME carriers. Theoretical studies find these molecules to be able to form and persist in the dense interstellar environments where AME is typically observed. Implications of the existence of this class of molecules are discussed in terms of physical and chemical processes in dense molecular clouds.

  11. The cavefish genome reveals candidate genes for eye loss.

    PubMed

    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

  12. Candidates for twin chiral bands in 102Rh.

    PubMed

    Tonev, D; Yavahchova, M S; Goutev, N; de Angelis, G; Petkov, P; Bhowmik, R K; Singh, R P; Muralithar, S; Madhavan, N; Kumar, R; Kumar Raju, M; Kaur, J; Mohanto, G; Singh, A; Kaur, N; Garg, R; Shukla, A; Marinov, Ts K; Brant, S

    2014-02-01

    Excited states in 102Rh, populated in the fusion-evaporation reaction Zr94(11B,3n)102Rh at a beam energy of 36 MeV, were studied using the Indian National Gamma Array spectrometer at Inter University Accelerator Center, New Delhi. The angular correlations and the electromagnetic character of some of the gamma-ray transitions observed were investigated in detail. A new chiral candidate sister band was found. Lifetimes of exited states in both chiral candidate bands of 102Rh were measured for the first time in the A∼100 mass region by means of the Doppler-shift attenuation technique. The derived reduced transition probabilities are compared to the predictions of the two quasiparticles plus triaxial rotor model. Both experimental results and calculations do not support the presence of static chirality in 102Rh. PMID:24580588

  13. Corrosion Behavior of Candidate Alloys for Supercritical Water Reactors

    SciTech Connect

    Sridharan, K.; Zillmer, A.; Licht, J.R.; Allen, T.R.; Anderson, M.H.; Tan, L.

    2004-07-01

    The corrosion and stress corrosion cracking behavior of metallic cladding and other core internal structures is critical to the success of the Generation IV Supercritical Water-cooled Reactors (SCWR). The eventual materials selected will be chosen based on the combined corrosion, stress-corrosion, mechanical performance, and radiation stability properties. Among the materials being considered are austenitic stainless steels, ferritic/martensitic steels, and nickel-base alloys. This paper reports initial studies on the corrosion performance of the candidate alloys 316 austenitic stainless steel, Inconel 718, and Zircaloy-2, all exposed to supercritical water at 300-500 deg. C in a corrosion loop at the University of Wisconsin. Long-term corrosion performance of AISI 347, also a candidate austenitic steel, has also been examined by sectioning samples from a component that was exposed for a period of about 30 years in supercritical water at the Genoa 3 Supercritical Water fossil power plant located in Genoa, Wisconsin. (authors)

  14. Conceptual thinking for in silico prioritization of candidate disease genes.

    PubMed

    Tiffin, Nicki

    2011-01-01

    Prioritization of most likely etiological genes entails predicting and defining a set of characteristics that are most likely to fit the underlying disease gene and scoring candidates according to their fit to this "perfect disease gene" profile. This requires a full understanding of the disease phenotype, characteristics, and any available data on the underlying genetics of the disease. Public databases provide enormous and ever-growing amounts of information that can be relevant to the prioritization of etiological genes. Computational approaches allow this information to be retrieved in an automated and exhaustive way and can therefore facilitate the comprehensive mining of this information, including its combination with sets of empirically generated data, in the process of identifying most likely candidate disease genes.

  15. Assessment of candidate-expendable launch vehicles for large payloads

    NASA Technical Reports Server (NTRS)

    1984-01-01

    In recent years the U.S. Air Force and NASA conducted design studies of 3 expendable launch vehicle configurations that could serve as a backup to the space shuttle--the Titan 34D7/Centaur, the Atlas II/Centaur, and the shuttle-derived SRB-X--as well as studies of advanced shuttle-derived launch vehicles with much larger payload capabilities than the shuttle. The 3 candidate complementary launch vehicles are judged to be roughly equivalent in cost, development time, reliability, and payload-to-orbit performance. Advanced shuttle-derived vehicles are considered viable candidates to meet future heavy lift launch requirements; however, they do not appear likely to result in significant reduction in cost-per-pound to orbit.

  16. U.S. Presidential Candidate camps debate sciences issues

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2000-10-01

    While budget surpluses, social security, and tax cut proposals have been major focuses during the U.S. presidential campaign between Texas Governor George W Bush and Vice President Al Gore, the candidates also have staked out a number of important issues related to Earth sciences and the environment. Two recent debates between representatives of the Bush and Gore camps have helped to clarify these positions. The Washington Science Policy Alliance presented a candidates forum on science and technology policy on October 5 at the American Association for the Advancement of Science (AAAS), in Washington, D.C. On September 26, the non-profit National Environmental Policy Institute (NEPI) held a debate on presidential politics and the environment at the National Press Club, also in Washington, D.C.

  17. A new optical nova candidate in M 31

    NASA Astrophysics Data System (ADS)

    Burwitz, V.; Pietsch, W.; Cikota, M.; Henze, S.; Violat-Bordonau, F.

    2008-06-01

    We report the discovery of an optical nova candidate in M 31 on 10*120s stacked unfiltered CCD images obtained with a 0.45m f/2.8 reflector and a SBIG STL-11000M CCD Camera (3008 pixels x 2674 pixels each 9 x 9 micron square), of the Observatorio de La Sagra, Spain, on 2008 Jun 26.11 with a magnitude of 16.1. The object is visible on all individual images. The position for the nova candidate is RA = 00h42m27.81s, Dec = +41d14'48.2" (J2000, accuracy of 0.4"), which is 186" west and 80" south of the core of M 31.

  18. A thermodynamic approach to the affinity optimization of drug candidates.

    PubMed

    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.

  19. The cavefish genome reveals candidate genes for eye loss

    PubMed Central

    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

  20. 1990 astronaut candidate Thomas prepares bedding during wilderness training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Under a camouflage tarp, Donald A. Thomas assembles small pieces of wood for bedding during a wilderness survival training course at Fairchild Air Force Base in the state of Washington. Thomas, one of 23 1990 Group 13 astronaut candidates, participated in the training near Spokane, Washington, 08-26-90 through 08-30-90. The survival exercise is part of a year's evaluation and training program.

  1. Signature candidate of quantum chaos far from the semiclassical regime

    SciTech Connect

    Li, Shang-Bin Xu, Zhengyuan

    2014-03-15

    We numerically investigated the entanglement product in the simplest coupled kicked top model with the spin j = 1. Different from the dynamical pattern of entanglement in the semiclassical regime, two similar initial states may have discordant entanglement oscillations. A candidate of the quantum signature of this classical chaotic system was proposed. The potential antimonotonic relation between the rank correlation coefficient qualifying the concordant of two entanglement evolutions and the stationary entanglement was preliminarily revealed.

  2. Leadership scheme to develop the careers of talented candidates.

    PubMed

    Lynas, Karen

    2012-02-01

    The Top Leaders programme supports career development by identifying talented staff and equipping them with a range of management skills and approaches. The programme uses a diagnostic test to help candidates assess their strengths, leadership styles and development needs, and offers them 360 degrees feedback. This enables them to identify areas they need to develop to be effective and supportive leaders. Two case studies illustrate the programme in action.

  3. SPECTROSCOPY OF FAINT KEPLER MISSION EXOPLANET CANDIDATE HOST STARS

    SciTech Connect

    Everett, Mark E.; Silva, David R.; Howell, Steve B.; Szkody, Paula

    2013-07-10

    Stellar properties are measured for a large set of Kepler mission exoplanet candidate host stars. Most of these stars are fainter than 14th magnitude, in contrast to other spectroscopic follow-up studies. This sample includes many high-priority Earth-sized candidate planets. A set of model spectra are fitted to R {approx} 3000 optical spectra of 268 stars to improve estimates of T{sub eff}, log (g), and [Fe/H] for the dwarfs in the range 4750 {<=} T{sub eff} {<=} 7200 K. These stellar properties are used to find new stellar radii and, in turn, new radius estimates for the candidate planets. The result of improved stellar characteristics is a more accurate representation of this Kepler exoplanet sample and identification of promising candidates for more detailed study. This stellar sample, particularly among stars with T{sub eff} {approx}> 5200 K, includes a greater number of relatively evolved stars with larger radii than assumed by the mission on the basis of multi-color broadband photometry. About 26% of the modeled stars require radii to be revised upward by a factor of 1.35 or greater, and modeling of 87% of the stars suggest some increase in radius. The sample presented here also exhibits a change in the incidence of planets larger than 3-4 R{sub Circled-Plus} as a function of metallicity. Once [Fe/H] increases to {>=} - 0.05, large planets suddenly appear in the sample while smaller planets are found orbiting stars with a wider range of metallicity. The modeled stellar spectra, as well as an additional 84 stars of mostly lower effective temperatures, are made available to the community.

  4. NASA EM Followup of LIGO-Virgo Candidate Events

    NASA Technical Reports Server (NTRS)

    Blackburn, Lindy L.

    2011-01-01

    We present a strategy for a follow-up of LIGO-Virgo candidate events using offline survey data from several NASA high-energy photon instruments aboard RXTE, Swift, and Fermi. Time and sky-location information provided by the GW trigger allows for a targeted search for prompt and afterglow EM signals. In doing so, we expect to be sensitive to signals which are too weak to be publicly reported as astrophysical EM events.

  5. 1990 astronaut candidate Walz prepares snack during wilderness training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Sitting on a log, Carl E. Walz takes a break from survival training activities to prepare a snack. Walz spreads peanut butter on a cracker during a wilderness survival training course at Fairchild Air Force Base in the state of Washington. Walz, one of 23 1990 Group 13 astronaut candidates, participated in the training near Spokane, Washington, 08-26-90 through 08-30-90. The survival exercise is part of a year's evaluation and training program.

  6. Manned transportation system study - Evaluation of candidate transportation architectures

    NASA Technical Reports Server (NTRS)

    Lance, Nicholas; Klemer, R.; Sooter, C.

    1992-01-01

    The overall evaluation process, the tool developed to perform the evaluation, and the evaluation results in determining the right approach to meet the nation's mannned transportation needs are presented. To address the various considerations, architecture sets consisting of the candidate transportation systems are constructed. As this methodology results in multiple architectures to examine, an architecture evaluation tool was developed to facilitate the evaluation of the architecture attribute values from the system values of the attributes.

  7. Identification of new transitional disk candidates in Lupus with Herschel

    NASA Astrophysics Data System (ADS)

    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

  8. Genetics of osteoporosis: searching for candidate genes for bone fragility.

    PubMed

    Rocha-Braz, Manuela G M; Ferraz-de-Souza, Bruno

    2016-08-01

    The pathogenesis of osteoporosis, a common disease with great morbidity and mortality, comprises environmental and genetic factors. As with other complex disorders, the genetic basis of osteoporosis has been difficult to identify. Nevertheless, several approaches have been undertaken in the past decades in order to identify candidate genes for bone fragility, including the study of rare monogenic syndromes with striking bone phenotypes (e.g. osteogenesis imperfecta and osteopetroses), the analysis of individuals or families with extreme osteoporotic phenotypes (e.g. idiopathic juvenile and pregnancy-related osteoporosis), and, chiefly, genome-wide association studies (GWAS) in large populations. Altogether, these efforts have greatly increased the understanding of molecular mechanisms behind bone remodelling, which has rapidly translated into the development of novel therapeutic strategies, exemplified by the tales of cathepsin K (CTSK) and sclerostin (SOST). Additional biological evidence of involvement in bone physiology still lacks for several candidate genes arisen from GWAS, opening an opportunity for the discovery of new mechanisms regulating bone strength, particularly with the advent of high-throughput genomic technologies. In this review, candidate genes for bone fragility will be presented in comprehensive tables and discussed with regard to how their association with osteoporosis emerged, highlighting key players such as LRP5, WNT1 and PLS3. Current limitations in our understanding of the genetic contribution to osteoporosis, such as yet unidentified genetic modifiers, may be overcome in the near future with better genotypic and phenotypic characterisation of large populations and the detailed study of candidate genes in informative individuals with marked phenotype. PMID:27533615

  9. Production and characterization of a bovine liver candidate reference material

    NASA Astrophysics Data System (ADS)

    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.

  10. Evaluating candidate lost circulation materials for geothermal drilling

    SciTech Connect

    Loeppke, G.

    1986-01-01

    Sandia National Laboratories' Geothermal Technology Development Division is working to advance the state of the art of lost circulation prevention and control. For this purpose, a large-scale lost Circulation Test Facility was designed and built. This paper addresses the evaluation of candidate lost circulation materisl using this facility and also using the recommended practice of API RP 131. Test results from these facilities are compared and discussed for the materials tested.

  11. Leadership scheme to develop the careers of talented candidates.

    PubMed

    Lynas, Karen

    2012-02-01

    The Top Leaders programme supports career development by identifying talented staff and equipping them with a range of management skills and approaches. The programme uses a diagnostic test to help candidates assess their strengths, leadership styles and development needs, and offers them 360 degrees feedback. This enables them to identify areas they need to develop to be effective and supportive leaders. Two case studies illustrate the programme in action. PMID:22439500

  12. Three new optical nova candidates in M 31

    NASA Astrophysics Data System (ADS)

    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.

  13. IRAS observations of AGN candidates at low flux levels

    NASA Technical Reports Server (NTRS)

    Degrijp, Marinus H. K.; Keel, William C.; Miley, George K.

    1987-01-01

    IRAS additional observations were used to obtain a sample of point sources at much fainter flux levels than hitherto available through the IRAS Point Source Catalogue. This sample is being used to compile an incomplete but representative catalogue of faint IRAS candidate Active Galactic Nuclei (AGNs) and to study the evolution of the infrared bright galaxies. Ground based follow up observations (optical spectroscopy) are mainly hampered by identification confusion.

  14. The Ghostly Novae of Spirits: Candidates, Confirmations, and Classifications

    NASA Astrophysics Data System (ADS)

    Corgan, David William

    2015-08-01

    The SPIRITS (SPitzer InfraRed Intensive Transients Survey) project has surveyed 242 galaxies across multiple epochs for over a year, searching for gap transient and variable star activity. To date, a wealth of candidate objects has been discovered in the warm Spitzer data being used, with the current total at 1426 individual detections. The discovery, confirmation, follow-up, and comparison to prediction rates of these candidates is presented. Employing subjective detection methods, discussed herein, individual discovery to group confirmation rates were found to be less than 3.6%. Photometric confirmation with correlated team instruments left 53 sources of interest remaining for further study. These targets ranged across 30 different galaxies including IC2163, Messier 101, and NGC3198. Follow-up ground observations in the 1.2, 1.6, and 2.2 µm wavelengths with the legacy 2MASS instrument at MLOF (Mount Lemmon Observing Facility) are highlighted. The data reduction process which has evolved to improve detections by ~.6mag is also detailed. These results are supplemented by SPIRITS team input from a variety of world-class infrared facilities to produce overall nova candidate characteristics, which are included. In some cases this extends to light curves from confirmed and observed novae to depths of ~20mag, while in others it is restricted to limiting magnitudes of ~18 at sight of occurrence (the true “ghosts” of SPIRITS). Candidate novae have been separated into classes where data allows, including the possible discovery of a new variable type coined SMIRTS (Super Massive InfraRed TransientS), and probable members of the elusive Luminous Red Novae category. Finally, comparison of numerical survey results to nova prediction rates is undertaken and results presented. Where deviations from luminosity curve fittings occur, such as in the overly active M81 and IC0342 galaxies, possible causes are proposed.

  15. CANDID: Companion Analysis and Non-Detection in Interferometric Data

    NASA Astrophysics Data System (ADS)

    Gallenne, A.; Mérand, A.; Kervella, P.; Monnier, J. D.; Schaefer, G. H.; Baron, F.; Breitfelder, J.; Le Bouquin, J. B.; Roettenbacher, R. M.; Gieren, W.; Pietrzynski, G.; McAlister, H.; ten Brummelaar, T.; Sturmann, J.; Sturmann, L.; Turner, N.; Ridgway, S.; Kraus, S.

    2015-05-01

    CANDID finds faint companion around star in interferometric data in the OIFITS format. It allows systematically searching for faint companions in OIFITS data, and if not found, estimates the detection limit. The tool is based on model fitting and Chi2 minimization, with a grid for the starting points of the companion position. It ensures all positions are explored by estimating a-posteriori if the grid is dense enough, and provides an estimate of the optimum grid density.

  16. Screening of three Usher syndrome type II candidate genes

    SciTech Connect

    Bloemker, B.K.; Swaroop, A.; Kimberling, W.J.

    1994-09-01

    Usher syndrome type II (US2) is an autosomal recessive disorder that results in blindness due to retinitis pigmentosa and congenital hearing loss. The disease affects approximately 1 in 20,000 individuals in the general population and is responsible for over 50% of all cases of deafness with blindness. The underlying US2 defect is unknown. The US2 gene has been localized to the 1q41 region of chromosome 1 by linkage studies. Three genes previously localized to 1q were analyzed to assess their candidacy as the US2 gene. These were evaluated by PCR assays using DNA from a YAC contig spanning the US2 region on chromosome 1. The first gene evaluated was the human choroideremia-like gene (hCHML), which had been mapped to chromosome 1q. The sequence on 1q is a homologue of the human choroideremia gene on chromosome X. Choroideremia is a degenerative disorder causing ocular pathology similar to that observed in US2 patients. Therefore, hCHML is a candidate for the US2 gene. Two cDNAs (A and B) from an enriched human retinal pigment epithelium library have been mapped to 1q41 by in situ hybridization. Both cDNAs are considered good candidates. The hCHML and cDNA A were ruled out as candidates for the US2 gene based on negative results from PCR assays performed on YACs spanning the US2 region. cDNA B could not be ruled out as a candidate for the US2 gene by these assays. Answers to many clinical questions regarding US2 will only be resolved after the gene is identified and characterized. Eventually, understanding the function and expression of the US2 gene will provide a basis for the development of therapy.

  17. Late time observations of candidate high-z GRBs

    NASA Astrophysics Data System (ADS)

    Burlon, Davide; Gaensler, Bryan; Murphy, Tara; Hancock, Paul; Ghirlanda, Giancarlo; Salvaterra, Ruben; Ghisellini, Gabriele; Tagliaferri, Gianpiero

    2014-04-01

    This is a discovery (NAPA) proposal to detect the late time radio afterglow of candidates high redshift gamma ray bursts (GRBs). Our selection criteria (no redshift information at the time of the request, type of trigger, high-energy flux and duration) are based on information immediately available through the Swift/BAT telescope and ground based telescopes. Radio observations play a crucial role in determining the energetics of the GRB explosion, and will therefore directly point towards exceptional progenitors.

  18. Evaluation of the 1985-1990 IGRF secular variation candidates

    USGS Publications Warehouse

    Cain, J.C.; Kluth, C.

    1987-01-01

    The IGRF secular variation model for 1985-1990 was adopted by the International Association of Geomagnetism and Aeronomy at its Prague meeting in August 1985 as an average of the three candidate models submitted to the committee. We compared the three models at epoch 1985.0 against each other and against a new model based on observatory data available as of July 1, 1985. These comparisons showed that one of the three candidate models disagreed more with the other two and our model, especially in the eastern Pacific. None of the candidate models was seen to respond to a change in the secular variation of the vertical component that appears to have taken place most strongly in the western Pacific area since 1982. The lack of satellite data was seen to be a significant handicap towards prediction of the field change over most of the Earth's surface, especially the southern oceans. Maximum errors of any model are estimated to be of the order of 80 nT a-1. ?? 1987.

  19. THE COOLEST ISOLATED BROWN DWARF CANDIDATE MEMBER OF TWA

    SciTech Connect

    Gagné, Jonathan; Lafrenière, David; Doyon, René; Malo, Lison; Artigau, Étienne; Faherty, Jacqueline K.; Cruz, Kelle E-mail: jfaherty17@gmail.com

    2014-04-10

    We present two new late-type brown dwarf candidate members of the TW Hydrae association (TWA): 2MASS J12074836-3900043 and 2MASS J12474428-3816464, which were found as part of the BANYAN all-sky survey (BASS) for brown dwarf members of nearby young associations. We obtained near-infrared (NIR) spectroscopy for both objects (NIR spectral types are respectively L1 and M9), as well as optical spectroscopy for J1207-3900 (optical spectral type is L0γ), and show that both display clear signs of low gravity, and thus youth. We use the BANYAN II Bayesian inference tool to show that both objects are candidate members to TWA with a very low probability of being field contaminants, although the kinematics of J1247-3816 seem slightly at odds with that of other TWA members. J1207-3900 is currently the latest-type and the only isolated L-type candidate member of TWA. Measuring the distance and radial velocity of both objects is still required to claim them as bona fide members. Such late-type objects are predicted to have masses down to 11-15 M {sub Jup} at the age of TWA, which makes them compelling targets to study atmospheric properties in a regime similar to that of currently known imaged extrasolar planets.

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

    SciTech Connect

    Steffen, Jason H.; Batalha, Natalie M.; Borucki, William J.; Buchhave, Lars A.; Caldwell, Douglas A.; Cochran, William D.; Endl, Michael; Fabrycky, Daniel C.; Fressin, Francois; Ford, Eric B.; 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.